Effects of groundwater on radionuclides buried at the Nevada Test Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Martinez, B.A.; Maestas, S.; Thompson, J.L.

A large fraction of the radioactive source from a nuclear test is confined to the cavity created by the event. A {open_quotes}melt glass{close_quotes} accumulates at the bottom of the cavity where the highest concentrations of refractory radionuclides (e.g., Zr-95, Eu-155, Pu-239) are found. Most of the movement of radionuclides underground at the Nevada Test Site occurs through the agency of moving groundwater. Results from samples that were taken from the cavity formed in 1981 by the underground test named Baseball indicate that radioactive materials have remained where they were deposited during the formation of the cavity and chimney. There maymore » not be a mechanism for radionuclides to migrate at this location due to small hydraulic gradients and a low hydraulic conductivity. The study done at this site offers further evidence that extensive migration of radioactive materials away from underground nuclear test sites does not occur in the absence of appreciable groundwater movement.« less

Uranium mill tailings: nuclear waste and natural laboratory for geochemical and radioecological investigations

USGS Publications Warehouse

Landa, Edward R.

2004-01-01

Uranium mill tailings (UMT) are a high volume, low specific activity radioactive waste typically disposed in surface impoundments. This review focuses on research on UMT and related earth materials during the past decade relevant to the assessment of: (1) mineral hosts of radionuclides; (2) the use of soil analogs in predicting long-term fate of radionuclides; (3) microbial and diagenetic processes that may alter radionuclide mobility in the surficial environment; (4) waste-management technologies to limit radionuclide migration; and (5) the impact of UMT on biota.

Radionuclide Migration at the Rio Blanco Site, A Nuclear-stimulated Low-permeability Natural Gas Reservoir

DOE Office of Scientific and Technical Information (OSTI.GOV)

Clay A. Cooper; Ming Ye; Jenny Chapman

2005-10-01

The U.S. Department of Energy and its predecessor agencies conducted a program in the 1960s and 1970s that evaluated technology for the nuclear stimulation of low-permeability gas reservoirs. The third and final project in the program, Project Rio Blanco, was conducted in Rio Blanco County, in northwestern Colorado. In this experiment, three 33-kiloton nuclear explosives were simultaneously detonated in a single emplacement well in the Mesaverde Group and Fort Union Formation, at depths of 1,780, 1,899, and 2,039 m below land surface on May 17, 1973. The objective of this work is to estimate lateral distances that tritium released frommore » the detonations may have traveled in the subsurface and evaluate the possible effect of postulated natural-gas development on radionuclide migration. Other radionuclides were considered in the analysis, but the majority occur in relatively immobile forms (such as nuclear melt glass). Of the radionuclides present in the gas phase, tritium dominates in terms of quantity of radioactivity in the long term and contribution to possible whole body exposure. One simulation is performed for {sup 85}Kr, the second most abundant gaseous radionuclide produced after tritium.« less

Natural radionuclides in rocks and soils of the high-mountain regions of the Great Caucasus

NASA Astrophysics Data System (ADS)

Asvarova, T. A.; Abdulaeva, A. S.; Magomedov, M. A.

2012-06-01

The results of the radioecological survey in the high-mountain regions of the Great Caucasus at the heights from 2200 to 3800 m a.s.l. are considered. This survey encompassed the territories of Dagestan, Azerbaijan, Georgia, Chechnya, Northern Ossetia-Alania, Kabardino-Balkaria, Karachay-Cherkessia, and the Stavropol and Krasnodar regions. The natural γ background radiation in the studied regions is subjected to considerable fluctuations and varies from 6 to 40 μR/h. The major regularities of the migration of natural radionuclides 238U, 232Th, 226Ra, and 40K in soils in dependence on the particular environmental conditions (the initial concentration of the radionuclides in the parent material; the intensity of pedogenesis; the intensity of the vertical and horizontal migration; and the geographic, climatic, and landscape-geochemical factors) are discussed.

[Migration in soil and accumulation in plants of peaceful nuclear explosion products in Perm region].

PubMed

Raskosha, N G; Shuktova, I I

2015-01-01

The data on the migration capacity in soil and accumulation of 238Pu, 239, 240Pu, 137Cs and 90Sr by plants in the area of a peaceful nuclear explosion located in the taiga zone are presented. The influence of the soil parameters on the distribution and transformation forms of the radionuclides in the podzolic soil profile was studied. The major amounts of man-made radionuclides were found in the matter of the ground lip. The accumulation parameters of pollutants by plants were the highest for the leaves, young branches and conifer of trees.

Nanoparticles migration in fractured rocks and affects on contaminant migration

NASA Astrophysics Data System (ADS)

Missana, Tiziana; Garcia-Gutierrez, Miguel; Alonso, Ursula

2014-05-01

In previous studies, the transport behavior of artificial (gold and latex) and natural (smectite clay) colloids, within a planar fracture in crystalline rock, was analyzed. In order to better understand the effects of colloid size, shape and surface charge on nanoparticle migration and especially on filtration processes on natural rock surfaces, different clay colloids and oxide nanoparticles were selected and their transport studied as a function of the residence time. In all the cases, (a fraction of) the nanoparticles travelled in the fracture as fast as or faster than water (with a retardation factor, Rf ≤ 1) and the observed Rf, was related to the Taylor dispersion coefficient, accounting for colloid size, water velocity and fracture width. However, under most of the cases, in contrast to the behavior of a conservative tracer, colloids recovery was much lower than 100 %. Differences in recovery between different nanoparticles, under similar residence times, were analyzed. In order to evaluate the possible consequences, on contaminant migration, of the presence of nanoparticles in the system, transport tests were carried out with both colloids and sorbing radionuclides. The overall capacity for colloids of enhancing radionuclide migration in crystalline rock fractures is discussed. Acknowledgments: The research leading to these results received funding from EU FP7/2007-2011 grant agreement Nº 295487 (BELBAR, Bentonite Erosion: effects on the Long term performance of the engineered Barrier and Radionuclide Transport) and by the Spanish Government under the project NANOBAG (CTM2011-2797).

[On the effect of partial flooding on 137Cs and 90Sr in forest biogeocenosis].

PubMed

Perevolotskaia, T V; Bulavik, I M; Perevolotskiĭ, A N

2009-01-01

The analysis was made on 137Cs and 90Sr distribution oak, pine and hornbeam plantations depending on different under soil water levels. Intensity of 137Cs and of 90Sr migration along the vertical layers of soils is determined by under soil water level at a specific sampling site. The closer under soil water to the surface of the soil, the lowest radionuclide contamination is in the upper soil levels and the highest radionuclide contamination is in the deeper layers. The "fast" and "slow" quasi diffusion coefficients for 137Cs and for 90Sr and their contribution to the total migration of radionuclide through vertical soil levels were determined. A decrease in 137Cs and increase in 90Sr transfer factors to the elements of overground phytomass as a result of under soil water level lowering was established.

Artificial and natural radionuclides in soils of the southern and middle taiga zones of Komi Republic

NASA Astrophysics Data System (ADS)

Beznosikov, V. A.; Lodygin, E. D.; Shuktomova, I. I.

2017-07-01

Specific activities of artificial (137Cs, 90Sr) and natural (40K, 232Th, 226Ra) radionuclides in background soils of southern and middle taiga of Komi Republic have been estimated with consideration for the landscape-geochemical features of the territory. It has been shown that their accumulation and migration in soils are determined by the following factors: position in relief, texture, and organic matter content. No anomalous zones with increased contents of radionuclides in soils have been revealed.

Intrinsic and Carrier Colloid-facilitated transport of lanthanides through discrete fractures in chalk

NASA Astrophysics Data System (ADS)

Weisbrod, N.; Tran, E. L.; Klein-BenDavid, O.; Teutsch, N.

2015-12-01

Geological disposal of high-level radioactive waste is the long term solution for the disposal of long lived radionuclides and spent fuel. However, some radionuclides might be released from these repositories into the subsurface as a result of leakage, which ultimately make their way into groundwater. Engineered bentonite barriers around nuclear waste repositories are generally considered sufficient to impede the transport of radionuclides from their source to the groundwater. However, colloidal-sized mobile bentonite particles ("carrier" colloids) originating from these barriers have come under investigation as a potential transport vector for radionuclides sorbed to them. As lanthanides are generally accepted to have the same chemical behaviors as their more toxic actinide counterparts, lanthanides are considered an acceptable substitute for research on radionuclide transportation. This study aims to evaluate the transport behaviors of lanthanides in colloid-facilitated transport through a fractured chalk matrix and under geochemical conditions representative the Negev desert, Israel. The migration of Ce both with and without colloidal particles was explored and compared to the migration of a conservative tracer (bromide) using a flow system constructed around a naturally fractured chalk core. Results suggest that mobility of Ce as a solute is negligible. In experiments conducted without bentonite colloids, the 1% of the Ce that was recovered migrated as "intrinsic" colloids in the form of carbonate precipitates. However, the total recovery of the Ce increased to 9% when it was injected into the core in the presence of bentonite colloids and 13% when both bentonite and precipitate colloids were injected. This indicates that lanthanides are essentially immobile in chalk as a solute but may be mobile as carbonate precipitates. Bentonite colloids, however, markedly increase the mobility of lanthanides through fractured chalk matrices.

Ion beam analyses of radionuclide migration in heterogeneous rocks

DOE Office of Scientific and Technical Information (OSTI.GOV)

Alonso, Ursula; Missana, Tiziana; Garcia-Gutierrez, Miguel

2013-07-18

The migration of radionuclides (RN) in the environment is a topic of general interest, for its implications on public health, and it is an issue for the long-term safety studies of deep geological repositories (DGR) for high-level radioactive waste. The role played by colloids on RN migration is also of great concern. Diffusion and sorption are fundamental mechanisms controlling RN migration in rocks and many experimental approaches are applied to determine transport parameters for low sorbing RN in homogeneous rocks. However, it is difficult to obtain relevant data for high sorbing RN or colloids, for which diffusion lengths are extremelymore » short, or within heterogeneous rocks, where transport might be different in different minerals. The ion beam techniques Rutherford Backscattering Spectrometry (RBS) and micro-Particle Induced X-Ray Emission ({mu}PIXE), rarely applied in the field, were selected for their micro-analytical potential to study RN diffusion and surface retention within heterogeneous rocks. Main achievements obtained during last 12 years are highlighted.« less

TYBO/BENHAM: Model Analysis of Groundwater Flow and Radionuclide Migration from Underground Nuclear Tests in Southwestern Pahute Mesa, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Andrew Wolfsberg; Lee Glascoe; Guoping Lu

Recent field studies have led to the discovery of trace quantities of plutonium originating from the BENHAM underground nuclear test in two groundwater observation wells on Pahute Mesa at the Nevada Test Site. These observation wells are located 1.3 km from the BENHAM underground nuclear test and approximately 300 m from the TYBO underground nuclear test. In addition to plutonium, several other conservative (e.g. tritium) and reactive (e.g. cesium) radionuclides were found in both observation wells. The highest radionuclide concentrations were found in a well sampling a welded tuff aquifer more than 500m above the BENHAM emplacement depth. These measurementsmore » have prompted additional investigations to ascertain the mechanisms, processes, and conditions affecting subsurface radionuclide transport in Pahute Mesa groundwater. This report describes an integrated modeling approach used to simulate groundwater flow, radionuclide source release, and radionuclide transport near the BENHAM and TYBO underground nuclear tests on Pahute Mesa. The components of the model include a flow model at a scale large enough to encompass many wells for calibration, a source-term model capable of predicting radionuclide releases to aquifers following complex processes associated with nonisothermal flow and glass dissolution, and site-scale transport models that consider migration of solutes and colloids in fractured volcanic rock. Although multiple modeling components contribute to the methodology presented in this report, they are coupled and yield results consistent with laboratory and field observations. Additionally, sensitivity analyses are conducted to provide insight into the relative importance of uncertainty ranges in the transport parameters.« less

Hydrology of the solid waste burial ground as related to potential migration of radionuclides, Idaho National Engineering Laboratory

USGS Publications Warehouse

Barraclough, Jack T.; Robertson, J.B.; Janzer, V.J.; Saindon, L.G.

1976-01-01

A study was made (1970-1974) to evaluate the geohydrologic and geochemical controls on subsurface migration of radionuclides from pits and trenches in the Idaho National Engineering Laboratory (INEL) solid waste burial ground and to determine the existence and extent of radionuclide migration from the burial ground. A total of about 1,700 sediment, rock, and water samples were collected from 10 observation wells drilled in and near the burial ground of Idaho National Engineering Laboratory, formerly the National Reactor Testing Station (NRTS). Within the burial ground area, the subsurface rocks are composed principally of basalt. Wind- and water-deposited sediments occur at the surface and in beds between the thicker basalt zones. Two principal sediment beds occur at about 110 feet and 240 feet below the land surface. The average thickness of the surficial sedimentary layer is about 15 feet while that of the two principal subsurface layers is 13 and 14 feet, respectively. The water table in the aquifer beneath the burial ground is at a depth of about 580 feet. Fission, activation, and transuranic elements were detected in some of the samples from the 110- and 240-foot sedimentary layers. (Woodard-USGS)

Vertical Migration of Radionuclides in Soils on the Chernobyl Nuclear Power Plant (ChNPP) Exclusion Zone (1987-2007)

NASA Astrophysics Data System (ADS)

Jannik, G. T.; Ivanov, Y. A.; Kashparov, V. A.; Levchuk, S. E.; Bondarkov, M. D.; Maksymenko, A. M.; Farfan, E. B.; Marra, J. C.

2009-12-01

In 1986-1987, a set of experimental sites for studies of vertical migration of radionuclides released from the ChNPP was established in the ChNPP Exclusion Zone for various fallout plumes. The sites were selected considering local terrain and geo-chemical conditions, as well as physical and chemical characteristics of the fallout. The experimental sites included grasslands, and pre-Chernobyl cultivated meadows and croplands. Vertical migration of radionuclides in the ChNPP Exclusion Zone grasslands was evaluated. Parameters of 137Cs, 90Sr, and 239,240Pu transfer were calculated and the periods during which these radionuclides reach their ecological half-life in the upper 5 cm soil layer were estimated. Migration capabilities of these radionuclides in the grassland soils tend to decrease as follows: 90Sr >137Cs ≥ 239,240Pu. A significant retardation of the 137Cs vertical migration was shown in the grasslands long after the Chernobyl accident. During the 21st year after the fallout, average Tecol values for 137Cs (the period of time it takes in the environment for 137Cs to reach half the value of its original concentration in the upper 5 cm soil layer, regardless of physical decay) are as follows: 180 - 320 years for grassland containing automorphous mineral soils of a light granulometric composition; and 90 - 100 years for grassland containing hydromorphous organogenic soils. These values are significantly higher than those estimated for the period of 6-9 years after the fallout: 60 - 150 years and 11 - 20 years, respectively. The absolute 137Cs Tecol values are by factors of 3-7 higher than 137Cs radiological decay values long after the accident. Changes in the exposure dose resulting from the soil deposited 137Cs only depend on its radiological decay. This factor should necessarily be considered for development of predictive assessments, including dose exposures for the hypothetical population in case of their re-evacuation to the exclusion areas. The obtained results have to be considered for predictive assessments, including those for dose exposures for the hypothetical population in case of their re-evacuation to the exclusion areas if implementation and/or planning of remediation activities at the ChNPP Exclusion Zone are considered reasonable and appropriate.

Modeling Radionuclide Decay Chain Migration Using HYDROGEOCHEM

NASA Astrophysics Data System (ADS)

Lin, T. C.; Tsai, C. H.; Lai, K. H.; Chen, J. S.

2014-12-01

Nuclear technology has been employed for energy production for several decades. Although people receive many benefits from nuclear energy, there are inevitably environmental pollutions as well as human health threats posed by the radioactive materials releases from nuclear waste disposed in geological repositories or accidental releases of radionuclides from nuclear facilities. Theoretical studies have been undertaken to understand the transport of radionuclides in subsurface environments because that the radionuclide transport in groundwater is one of the main pathway in exposure scenarios for the intake of radionuclides. The radionuclide transport in groundwater can be predicted using analytical solution as well as numerical models. In this study, we simulate the transport of the radionuclide decay chain using HYDROGEOCHEM. The simulated results are verified against the analytical solution available in the literature. Excellent agreements between the numerical simulation and the analytical are observed for a wide spectrum of concentration. HYDROGECHEM is a useful tool assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

Mechanisms for surface contamination of soils and bottom sediments in the Shagan River zone within former Semipalatinsk Nuclear Test Site.

PubMed

Aidarkhanov, A O; Lukashenko, S N; Lyakhova, O N; Subbotin, S B; Yakovenko, Yu Yu; Genova, S V; Aidarkhanova, A K

2013-10-01

The Shagan River is the only surface watercourse within the former Semipalatinsk Test Site (STS). Research in the valley of the Shagan River was carried out to study the possible migration of artificial radionuclides with surface waters over considerable distances, with the possibility these radionuclides may have entered the Irtysh River. The investigations revealed that radioactive contamination of soil was primarily caused by the first underground nuclear test with soil outburst conducted at the "Balapan" site in Borehole 1004. The surface nuclear tests carried out at the "Experimental Field" site and global fallout made insignificant contributions to contamination. The most polluted is the area in the immediate vicinity of the "Atomic" Lake crater. Contamination at the site is spatial. The total area of contamination is limited to 10-12 km from the crater piles. The ratio of plutonium isotopes was useful to determine the source of soil contamination. There was virtual absence of artificial radionuclide migration with surface waters, and possible cross-border transfer of radionuclides with the waters of Shagan and Irtysh rivers was not confirmed. Copyright © 2013 Elsevier Ltd. All rights reserved.

Geomorphic control of radionuclide diffusion in desert soils

USGS Publications Warehouse

Pelletier, J.D.; Harrington, C.D.; Whitney, J.W.; Cline, M.; DeLong, S.B.; Keating, G.; Ebert, T.K.

2005-01-01

Diffusion is a standard model for the vertical migration of radionuclides in soil profiles. Here we show that diffusivity values inferred from fallout 137CS profiles in soils on the Fortymile Wash alluvial fan, Nye County, Nevada, have a strong inverse correlation with the age of the geomorphic surface. This result suggests that radionuclide-bound particles are predominantly transported by infiltration rather than by bulk-mixing processes such as wetting/ drying, freeze/thaw, and bioturbation. Our results provide a preliminary basis for using soil-geomorphic mapping, point-based calibration data, and the diffusion model to predict radionuclide trans desert soils within a pedotransfer-function approach. Copyright 2005 by the American Geophysical Union.

Characterization of Discharge Areas of Radionuclides Originating From Nuclear Waste Repositories

NASA Astrophysics Data System (ADS)

Marklund, L.; Xu, S.; Worman, A.

2009-05-01

If leakages in nuclear waste repositories located in crystalline bedrock arise, radionuclides will reach the biosphere and cause a risk of radiological impact. The extent of the radiological impact depends on in which landscape elements the radionuclides emerge. In this study, we investigate if there are certain landscape elements that generally will act as discharge areas for radionuclides leaking from subsurface deposits. We also characterize the typical properties that distinguish these areas from others. In humid regions, landscape topography is the most important driving force for groundwater flow. Because groundwater is the main transporting agent for migrating radionuclides, the topography will determine the flowpaths of leaking radionuclides. How topography and heterogeneities in the subsurface affect the discharge distribution of the radionuclides is therefore an important scope of this study. To address these issues, we developed a 3-D transport model. Our analyses are based on site-specific data from two different areas in Sweden, Forsmark, Uppland, and Oskarshamn, Småland. The Swedish Nuclear Waste Management Company (SKB) has selected these two areas as candidate areas for a deep repository of nuclear waste and the areas are currently subject to site investigations. Our results suggest that there are hot-spots in the landscape i.e. areas with high probability of receiving large amounts of radionuclides from a leaking repository of nuclear waste. The hot-spots concentrate in the sea, streams, lakes and wetlands. All these elements are found at lower elevations in the landscape. This pattern is mostly determined by the landscape topography and the locations of fracture zones. There is a relationship between fracture zones and topography, and therefore the importance of the topography for the discharge area distribution is not contradicted by the heterogeneity in the bedrock. The varieties of landscape elements which have potential for receiving significant amounts of radionuclides are limited. To limit the radiological dose assessment, analyses should be focused to and more detailed in such landscape areas in which doses are expected to be high. Due to the similarities among deep groundwater discharge areas, one can make site-specific analyses of those areas, which have a broad applicability for migration of radionuclides originating from a nuclear waste repository.

[Trans-uranium elements in food products (review)].

PubMed

Vasilenko, I Ia

1994-01-01

The data of Russian and foreign authors concerning of level environmental contamination and migration of transuranic elements in food chains, metabolism and biological danger of nuclides entering in human body with foods are reviewed. A level of radionuclide load of population and doses of radiation are discussed and the danger is estimated. The doses of radiation from radionuclide ingestion are lower than level of allowed radiation safety standards.

Mobility of Source Zone Heavy Metals and Radionuclides: The Mixed Roles of Fermentative Activity on Fate and Transport of U and Cr. Final Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gerlach, Robin; Peyton, Brent M.; Apel, William A.

2014-01-29

Various U. S. Department of Energy (DOE) low and medium-level radioactive waste sites contain mixtures of heavy metals, radionuclides and assorted organic materials. In addition, there are numerous sites around the world that are contaminated with a mixture of organic and inorganic contaminants. In most sites, over time, water infiltrates the wastes, and releases metals, radionuclides and other contaminants causing transport into the surrounding environment. We investigated the role of fermentative microorganisms in such sites that may control metal, radionuclide and organics migration from source zones. The project was initiated based on the following overarching hypothesis: Metals, radionuclides and othermore » contaminants can be mobilized by infiltration of water into waste storage sites. Microbial communities of lignocellulose degrading and fermenting microorganisms present in the subsurface of contaminated DOE sites can significantly impact migration by directly reducing and immobilizing metals and radionuclides while degrading complex organic matter to low molecular weight organic compounds. These low molecular weight organic acids and alcohols can increase metal and radionuclide mobility by chelation (i.e., certain organic acids) or decrease mobility by stimulating respiratory metal reducing microorganisms. We demonstrated that fermentative organisms capable of affecting the fate of Cr6+, U6+ and trinitrotoluene can be isolated from organic-rich low level waste sites as well as from less organic rich subsurface environments. The mechanisms, pathways and extent of contaminant transformation depend on a variety of factors related to the type of organisms present, the aqueous chemistry as well as the geochemistry and mineralogy. This work provides observations and quantitative data across multiple scales that identify and predict the coupled effects of fermentative carbon and electron flow on the transport of radionuclides, heavy metals and organic contaminants in the subsurface; a primary concern of the DOE Environmental Remediation Science Division (ERSD) and Subsurface Geochemical Research (SBR) Program.« less

GIS Modelling of Radionuclide Transport from the Semipalatinsk Test Site

NASA Astrophysics Data System (ADS)

Balakay, L.; Zakarin, E.; Mahura, A.; Baklanov, A.; Sorensen, J. H.

2009-04-01

In this study, the software complex GIS-project MigRad (Migration of Radionuclide) was developed, tested and applied for the territory of the Semipalatinsk test site/ polygon (Republic of Kazakhstan), where since 1961, in total 348 underground nuclear explosions were conducted. The MigRad is oriented on integration of large volumes of different information (mapping, ground-based, and satellite-based survey): and also includes modeling on its base local redistribution of radionuclides by precipitation and surface waters and by long-range transport of radioactive aerosols. The existing thermal anomaly on territory of the polygon was investigated in details, and the object-oriented analysis was applied for the studied area. Employing the RUNOFF model, the simulation of radionuclides migration with surface waters was performed. Employing the DERMA model, the simulation of long-term atmospheric transport, dispersion and deposition patterns for cesium was conducted from 3 selected locations (Balapan, Delegen, and Experimental Field). Employing geoinformation technology, the mapping of the of the high temperature zones and epicenters of radioactive aerosols transport for the territory of the test site was carried out with post-processing and integration of modelling results into GIS environment. Contamination levels of pollution due to former nuclear explosions for population and environment of the surrounding polygon territories of Kazakhstan as well as adjacent countries were analyzed and evaluated. The MigRad was designed as instrument for comprehensive analysis of complex territorial processes influenced by former nuclear explosions on the territory of Semipalatinsk test site. It provides possibilities in detailed analyses for (i) extensive cartographic material, remote sensing, and field measurements data collected in different level databases; (ii) radionuclide migration with flows using accumulation and redistribution of soil particles; (iii) thermal anomalies caused by explosions and observed on the test site and adjacent territories, and (iv) long-range transport of radioactive aerosols with analysis of dynamics of spatial distribution, averaged and accumulated fields for concentration and deposition patterns.

A random walk model to simulate the atmospheric dispersion of radionuclide

NASA Astrophysics Data System (ADS)

Zhuo, Jun; Huang, Liuxing; Niu, Shengli; Xie, Honggang; Kuang, Feihong

2018-01-01

To investigate the atmospheric dispersion of radionuclide in large-medium scale, a numerical simulation method based on random walk model for radionuclide atmospheric dispersion was established in the paper. The route of radionuclide migration and concentration distribution of radionuclide can be calculated out by using the method with the real-time or historical meteorological fields. In the simulation, a plume of radionuclide is treated as a lot of particles independent of each other. The particles move randomly by the fluctuations of turbulence, and disperse, so as to enlarge the volume of the plume and dilute the concentration of radionuclide. The dispersion of the plume over time is described by the variance of the particles. Through statistical analysis, the relationships between variance of the particles and radionuclide dispersion characteristics can be derived. The main mechanisms considered in the physical model are: (1) advection of radionuclide by mean air motion, (2) mixing of radionuclide by atmospheric turbulence, (3) dry and wet deposition, (4) disintegration. A code named RADES was developed according the method. And then, the European Tracer Experiment (ETEX) in 1994 is simulated by the RADES and FLEXPART codes, the simulation results of the concentration distribution of tracer are in good agreement with the experimental data.

Radionuclide Retention in Concrete Wasteforms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bovaird, Chase C.; Jansik, Danielle P.; Wellman, Dawn M.

2011-09-30

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate predictionmore » of radionuclide fate when the wasteforms come in contact with groundwater. The information present in the report provides data that (1) measures the effect of concrete wasteform properties likely to influence radionuclide migration; and (2) quantifies the rate of carbonation of concrete materials in a simulated vadose zone repository.« less

Radionuclide Incorporation and Long Term Performance of Apatite Waste Forms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, Jianwei; Lian, Jie; Gao, Fei

2016-01-04

This project aims to combines state-of-the-art experimental and characterization techniques with atomistic simulations based on density functional theory (DFT) and molecular dynamics (MD) simulations. With an initial focus on long-lived I-129 and other radionuclides such as Cs, Sr in apatite structure, specific research objectives include the atomic scale understanding of: (1) incorporation behavior of the radionuclides and their effects on the crystal chemistry and phase stability; (2) stability and microstructure evolution of designed waste forms under coupled temperature and radiation environments; (3) incorporation and migration energetics of radionuclides and release behaviors as probed by DFT and molecular dynamics (MD) simulations;more » and (4) chemical durability as measured in dissolution experiments for long term performance evaluation and model validation.« less

Uranium and Cesium sorption to bentonite colloids in high salinity and carbonate-rich environments: Implications for radionuclide transport

NASA Astrophysics Data System (ADS)

Tran, E. L.; Teutsch, N.; Klein-BenDavid, O.; Weisbrod, N.

2017-12-01

When radionuclides are leaked into the subsurface due to engineered waste disposal container failure, the ultimate barrier to migration of radionuclides into local aquifers is sorption to the surrounding rock matrix and sediments, which often includes a bentonite backfill. The extent of this sorption is dependent on pH, ionic strength, surface area availability, radionuclide concentration, surface mineral composition, and solution chemistry. Colloidal-sized bentonite particles eroded from the backfill have been shown to facilitate the transport of radionuclides sorbed to them away from their source. Thus, sorption of radionuclides such as uranium and cesium to bentonite surfaces can be both a mobilization or retardation factor. Though numerous studies have been conducted to-date on sorption of radionuclides under low ionic strength and carbonate-poor conditions, there has been little research conducted on the behavior of radionuclides in high salinities and carbonate rich conditions typical of aquifers in the vicinity of some potential nuclear repositories. This study attempts to characterize the sorption properties of U(VI) and Cs to bentonite colloids under these conditions using controlled batch experiments. Results indicated that U(VI) undergoes little to no sorption to bentonite colloids in a high-salinity (TDS= 9000 mg/L) artificial groundwater. This lack of sorption was attributed to the formation of CaUO2(CO3)22- and Ca2UO2(CO3)3 aqueous ions which stabilize the UO22+ ions in solution. In contrast, Cs exhibited greater sorption, the extent to which was influenced greatly by the matrix water's ionic strength and the colloid concentration used. Surprisingly, when both U and Cs were together, the presence of U(VI) in solution decreased Cs sorption, possibly due to the formation of stabilizing CaUO2(CO3)22- anions. The implications of this research are that rather than undergoing colloid-facilitated transport, U(VI) is expected to migrate similarly to a conservative dissolved species under these conditions, and little retardation through sorption onto the surrounding rock matrix is predicted. Cs is expected to undergo more sorption, though U(VI) presence may have a mobilizing effect.

Monitoring radionuclide contamination in the unsaturated zone - Lessons learned at the Amargosa Desert Research Site, Nye County, Nevada

USGS Publications Warehouse

Stonestrom, David A.; Abraham, Jared D.; Andraski, Brian J.; Baker, Ronald J.; Mayers, C. Justin; Michel, Robert L.; Prudic, David E.; Striegl, Robert G.; Walvoord, Michelle Ann

2004-01-01

Contaminant-transport processes are being investigated at the U.S. Geological Survey’s Amargosa Desert Research Site (A DRS), adjacent to the Nation’s first commercial disposal facility for low-level radioactive waste. Gases containing tritium and radiocarbon are migrating through a 110-m thick unsaturated zone from unlined trenches that received waste from 1962 to 1992. Results relevant to long- term monitoring of radionuclides are summarized as follows. Contaminant plumes have unexpected histories and spatial configurations due to uncertainties in the: (1) geologic framework, (2) biochemical reactions involving waste components, (3) interactions between plume components and unsaturated-zone materials, (4) disposal practices, and (5) physical transport processes. Information on plume dynamics depends on ex-situ wet-chemical techniques because in-situ sensors for the radionuclides of interest do not exist. As at other radioactive-waste disposal facilities, radionuclides at the ADRS are mixed with varying amounts of volatile organic compounds (VOCs). Carbon-dioxide and VOC anomalies provide proxies for radioactive contamination. Contaminants in the unsaturated zone migrate along preferential pathways. Effective monitoring thus requires accurate geologic characterization. Direct- current electrical-resistivity imaging successfully mapped geologic units controlling preferential transport at the ADRS. Direct sampling of water from the unsaturated zone is complex and time consuming. Sampling plant water is an efficient alternative for mapping shallow tritium contamination.

Fast analysis of radionuclide decay chain migration

NASA Astrophysics Data System (ADS)

Chen, J. S.; Liang, C. P.; Liu, C. W.; Li, L.

2014-12-01

A novel tool for rapidly predicting the long-term plume behavior of an arbitrary length radionuclide decay chain is presented in this study. This fast tool is achieved based on generalized analytical solutions in compact format derived for a set of two-dimensional advection-dispersion equations coupled with sequential first-order decay reactions in groundwater system. The performance of the developed tool is evaluated by a numerical model using a Laplace transform finite difference scheme. The results of performance evaluation indicate that the developed model is robust and accurate. The developed model is then used to fast understand the transport behavior of a four-member radionuclide decay chain. Results show that the plume extents and concentration levels of any target radionuclide are very sensitive to longitudinal, transverse dispersion, decay rate constant and retardation factor. The developed model are useful tools for rapidly assessing the ecological and environmental impact of the accidental radionuclide releases such as the Fukushima nuclear disaster where multiple radionuclides leaked through the reactor, subsequently contaminating the local groundwater and ocean seawater in the vicinity of the nuclear plant.

[Migration of industrial radionuclides in soils and benthal deposits at the coastal margins of the temporary waste storage facility (TWSF) of the Northwest Center for Radioactive Waste Management (SevRAO) and its influence on the possible contamination of the sea offshore waters].

PubMed

Filonova, A A; Seregin, V A

2014-01-01

For obtaining the integral information about the current radiation situation in the sea offshore waters of the temporary waste storage facility (TWSF) of the Northwest Center for Radioactive Waste Management "SevRAO" in the Andreeva Bay and in the settle Gremikha with a purpose of a comprehensive assessment of its condition there was performed radiation-ecological monitoring of the adjacent sea offshore waters of the TWSF. It was shown that in the territory of industrial sites of the TWSF as a result of industrial activity there are localized areas of pollution by man-made radionuclides. As a result of leaching of radionuclides by tidal stream, snowmelt and rainwater radioactive contamination extends beyond the territory of the sanitary protection zone and to the coastal sea offshore waters. To confirm the coastal pollution of the sea offshore waters the levels of mobility of 90Sr and 137Cs in environmental chains and bond strength of them with the soil and benthal deposits were clarified by determining with the method of detection of the forms of the presence of radionuclides in these media. There was established a high mobility of 137Cs and 90Sr in soils and benthal deposits (desorption coefficient (Kd) of 137Cs and 90Sr (in soils - 0.56 and 0.98), in the sediments - 0.82). The migration of radionuclides in environmental chains can lead to the contamination of the environment, including the sea offshore waters.

Migration of conservative and sorbing radionuclides in heterogeneous fractured rock aquifers at the Nevada Test Site

NASA Astrophysics Data System (ADS)

Boryta, J. R.; Wolfsberg, A. V.

2003-12-01

The Nevada Test Site (NTS) is the United States continental nuclear weapons testing site. The larger underground tests, including BENHAM and TYBO, were conducted at Pahute Mesa. The BENHAM test, conducted in 1968, was detonated 1.4 km below the surface and the TYBO test, conducted in 1975, was detonated at a depth of 765 m. Between 1996 and 1998, several radionuclides were discovered in trace concentrations in a monitoring well complex 273 m from TYBO and 1300 m from BENHAM. Previous studies associated with these measurements have focused primarily on a) plutonium discovered in the observation wells, which was identified through isotopic finger printing as originating at BENHAM, b) colloid-facilitated plutonium transport processes, and c) vertical convection in subsurface nuclear test collapse chimneys. In addition to plutonium, several other non-, weakly-, and strongly-sorbing radionuclides were discovered in trace concentrations in the observation wells, including tritium, carbon-14, chlorine-36, iodine-129, technetium-99, neptunium-237, strontium-90, cesium-137, americium-241, and europium-152,154,155. The range in retardation processes affecting these different radionuclides provides additional information for assessing groundwater solute transport model formulations. For all radionuclides, simulation results are most sensitive to the fracture porosity and fracture aperture. Additionally, for weakly sorbing Np, simulation results are highly sensitive to the matrix sorption coefficient. For strongly sorbing species, migration in the absence of colloids can only be simulated if fracture apertures are set very large, reducing the amount of diffusion that can occur. For these species, colloid-facilitated transport appears to be a more likely explanation for the measurements. This is corroborated with colloid-transport model simulations.

Salmon migration patterns revealed the temporal and spatial fluctuations of the radiocesium levels in terrestrial and ocean environments.

PubMed

Arai, Takaomi

2014-01-01

The disabling of the Fukushima Daiichi Nuclear Power Plant (F1NPP) resulted in the release of radionuclides, including 134Cs and 137Cs, into the air and the ocean. The unpredicted nuclear accident is of global concern for human health and the ecosystem. Although investigations of radionuclides in environments were performed shortly after the accident started, the temporal and spatial impacts and fluctuations on the releasing radionuclides to natural environment remain unclear. I focused on salmon, which migrate from inland to the open ocean globally, to reveal the three-year (May 2011 to February 2014) fluctuations and accumulations of 134Cs and 137Cs from terrestrial to open ocean environments after the F1NPP accident. The 134Cs and 137Cs concentrations in six salmonids exhibited lower temporal variations for three years after the F1NPP accident, suggesting that these radionuclides are widely distributed and these radionuclides remain in the natural environment globally with less convergence. The accumulation patterns were significantly different among the different salmon species. Fluvial (freshwater residence) type salmons exhibited significantly higher accumulation in 134Cs (25.3-40.2 Bq kg(-1) in mean) and 137Cs (41.4-51.7 Bq kg(-1) in mean) than did the anadromous (sea-run) type salmons (0.64-8.03 Bq kg(-1) in mean 134Cs and 0.42-10.2 Bq kg(-1) in mean 137Cs) suggesting widespread contamination in terrestrial environments versus the coastal and open ocean environments. Salmonids are the most highly migratory animals and are characterised by their strong tendency to return home to their natal site for reproduction. Salmonids have a potential to be a good indicator as an effective monitoring animal.

The role of organic complexants and microparticulates in the facilitated transport of radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schilk, A.J.; Robertson, D.E.; Abel, K.H.

1996-12-01

This progress report describes the results of ongoing radiological and geochemical investigations of the mechanisms of radionuclide transport in groundwater at two low-level waste (LLW) disposal sites within the waste management area of the Chalk River Laboratories (CRL), Ontario, Canada. These sites, the Chemical Pit liquid disposal facility and the Waste Management Area C solid LLW disposal site, have provided valuable 30- to 40-year-old field locations for characterizing the migration of radionuclides and evaluating a number of recent site performance objectives for LLW disposal facilities. This information will aid the NRC and other federal, state, and local regulators, as wellmore » as LLW disposal site developers and waste generators, in maximizing the effectiveness of existing or projected LLW disposal facilities for isolating radionuclides from the general public and thereby improving the health and safety aspects of LLW disposal.« less

Use of thermodynamic sorption models to derive radionuclide Kd values for performance assessment: Selected results and recommendations of the NEA sorption project

USGS Publications Warehouse

Ochs, M.; Davis, J.A.; Olin, M.; Payne, T.E.; Tweed, C.J.; Askarieh, M.M.; Altmann, S.

2006-01-01

For the safe final disposal and/or long-term storage of radioactive wastes, deep or near-surface underground repositories are being considered world-wide. A central safety feature is the prevention, or sufficient retardation, of radionuclide (RN) migration to the biosphere. To this end, radionuclide sorption is one of the most important processes. Decreasing the uncertainty in radionuclide sorption may contribute significantly to reducing the overall uncertainty of a performance assessment (PA). For PA, sorption is typically characterised by distribution coefficients (Kd values). The conditional nature of Kd requires different estimates of this parameter for each set of geochemical conditions of potential relevance in a RN's migration pathway. As it is not feasible to measure sorption for every set of conditions, the derivation of Kd for PA must rely on data derived from representative model systems. As a result, uncertainty in Kd is largely caused by the need to derive values for conditions not explicitly addressed in experiments. The recently concluded NEA Sorption Project [1] showed that thermodynamic sorption models (TSMs) are uniquely suited to derive K d as a function of conditions, because they allow a direct coupling of sorption with variable solution chemistry and mineralogy in a thermodynamic framework. The results of the project enable assessment of the suitability of various TSM approaches for PA-relevant applications as well as of the potential and limitations of TSMs to model RN sorption in complex systems. ?? by Oldenbourg Wissenschaftsverlag.

Radionuclide inventories for the F- and H-area seepage basin groundwater plumes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiergesell, Robert A; Kubilius, Walter P.

2016-05-01

Within the General Separations Areas (GSA) at the Savannah River Site (SRS), significant inventories of radionuclides exist within two major groundwater contamination plumes that are emanating from the F- and H-Area seepage basins. These radionuclides are moving slowly with groundwater migration, albeit more slowly due to interaction with the soil and aquifer matrix material. The purpose of this investigation is to quantify the activity of radionuclides associated with the pore water component of the groundwater plumes. The scope of this effort included evaluation of all groundwater sample analyses obtained from the wells that have been established by the Environmental Compliancemore » & Area Completion Projects (EC&ACP) Department at SRS to monitor groundwater contamination emanating from the F- and H-Area Seepage Basins. Using this data, generalized groundwater plume maps for the radionuclides that occur in elevated concentrations (Am-241, Cm-243/244, Cs-137, I-129, Ni-63, Ra-226/228, Sr-90, Tc-99, U-233/234, U-235 and U-238) were generated and utilized to calculate both the volume of contaminated groundwater and the representative concentration of each radionuclide associated with different plume concentration zones.« less

Recent advances in the detection of specific natural organic compounds as carriers for radionuclides in soil and water environments, with examples of radioiodine and plutonium

DOE PAGES

Santschi, P. H.; Xu, C.; Zhang, S.; ...

2017-03-09

Among the key environmental factors influencing the fate and transport of radionuclides in the environment is natural organic matter (NOM). While this has been known for decades, there still remains great uncertainty in predicting NOM-radionuclide interactions because of lack of understanding of radionuclide interactions with the specific organic moieties within NOM. Furthermore, radionuclide-NOM studies conducted using modelled organic compounds or elevated radionuclide concentrations provide compromised information related to true environmental conditions. Thus, sensitive techniques are required not only for the detection of radionuclides, and their different species, at ambient and/or far-field concentrations, but also for potential trace organic compounds thatmore » are chemically binding these radionuclides. GC-MS and AMS techniques developed in our lab are reviewed in this paper that aim to assess how two radionuclides, iodine and plutonium, form strong bonds with NOM by entirely different mechanisms; iodine tends to bind to aromatic functionalities, whereas plutonium binds to N-containing hydroxamate siderophores at ambient concentrations. While low-level measurements are a prerequisite for assessing iodine and plutonium migration at nuclear waste sites and as environmental tracers, it is necessary to determine their in-situ speciation, which ultimately controls their mobility and transport in natural environments. Finally and more importantly, advanced molecular-level instrumentation (e.g., nuclear magnetic resonance (NMR) and Fourier-transform ion cyclotron resonance coupled with electrospray ionization (ESI-FTICRMS) were applied to resolve either directly or indirectly the molecular environments in which the radionuclides are associated with the NOM.« less

Recent advances in the detection of specific natural organic compounds as carriers for radionuclides in soil and water environments, with examples of radioiodine and plutonium

DOE Office of Scientific and Technical Information (OSTI.GOV)

Santschi, P. H.; Xu, C.; Zhang, S.

Among the key environmental factors influencing the fate and transport of radionuclides in the environment is natural organic matter (NOM). While this has been known for decades, there still remains great uncertainty in predicting NOM-radionuclide interactions because of lack of understanding of radionuclide interactions with the specific organic moieties within NOM. Furthermore, radionuclide-NOM studies conducted using modelled organic compounds or elevated radionuclide concentrations provide compromised information related to true environmental conditions. Thus, sensitive techniques are required not only for the detection of radionuclides, and their different species, at ambient and/or far-field concentrations, but also for potential trace organic compounds thatmore » are chemically binding these radionuclides. GC-MS and AMS techniques developed in our lab are reviewed in this paper that aim to assess how two radionuclides, iodine and plutonium, form strong bonds with NOM by entirely different mechanisms; iodine tends to bind to aromatic functionalities, whereas plutonium binds to N-containing hydroxamate siderophores at ambient concentrations. While low-level measurements are a prerequisite for assessing iodine and plutonium migration at nuclear waste sites and as environmental tracers, it is necessary to determine their in-situ speciation, which ultimately controls their mobility and transport in natural environments. Finally and more importantly, advanced molecular-level instrumentation (e.g., nuclear magnetic resonance (NMR) and Fourier-transform ion cyclotron resonance coupled with electrospray ionization (ESI-FTICRMS) were applied to resolve either directly or indirectly the molecular environments in which the radionuclides are associated with the NOM.« less

Problems in shallow land disposal of solid low-level radioactive waste in the united states

USGS Publications Warehouse

Stevens, P.R.; DeBuchananne, G.D.

1976-01-01

Disposal of solid low-level wastes containing radionuclides by burial in shallow trenches was initiated during World War II at several sites as a method of protecting personnel from radiation and isolating the radionuclides from the hydrosphere and biosphere. Today, there are 11 principal shallow-land burial sites in the United States that contain a total of more than 1.4 million cubic meters of solid wastes contaminated with a wide variety of radionuclides. Criteria for burial sites have been few and generalized and have contained only minimal hydrogeologic considerations. Waste-management practices have included the burial of small quantities of long-lived radionuclides with large volumes of wastes contaminated with shorter-lived nuclides at the same site, thereby requiring an assurance of extremely long-time containment for the entire disposal site. Studies at 4 of the 11 sites have documented the migration of radionuclides. Other sites are being studied for evidence of containment failure. Conditions at the 4 sites are summarized. In each documented instance of containment failure, ground water has probably been the medium of transport. Migrating radionuclides that have been identified include90Sr,137Cs,106Ru,239Pu,125Sb,60Co, and3H. Shallow land burial of solid wastes containing radionuclides can be a viable practice only if a specific site satisfies adequate hydrogeologic criteria. Suggested hydrogeologic criteria and the types of hydrogeologic data necessary for an adequate evaluation of proposed burial sites are given. It is mandatory that a concomitant inventory and classification be made of the longevity, and the physical and chemical form of the waste nuclides to be buried, in order that the anticipated waste types can be matched to the containment capability of the proposed sites. Ongoing field investigations at existing sites will provide data needed to improve containment at these sites and help develop hydrogeologic criteria for new sites. These studies have necessitated the development of special drilling, sampling, well construction, and testing techniques. A recent development in borehole geophysical techniques is downhole spectral gammaray analysis which not only locates but identifies specific radionuclides in the subsurface. Field investigations are being supplemented by laboratory studies of the hydrochemistry of the transuranic elements, the kinetics of solid-liquid phase interactions, and the potential complexing of radionuclides with organic compounds and solvents which mobilize normally highly sorbable nuclides. Theoretical studies of digital predictive solute transport models are being implemented to assure their availability for application to problems and processes identified in the field and laboratory. ?? 1976 International Association of Engineering Geology.

Radionuclide Migration through Sediment and Concrete: 16 Years of Investigations

DOE Office of Scientific and Technical Information (OSTI.GOV)

Golovich, Elizabeth C.; Mattigod, Shas V.; Snyder, Michelle MV

The Waste Management Project provides safe, compliant, and cost-effective waste management services for the Hanford Site and the U.S. Department of Energy (DOE) complex. Part of these services includes safe disposal of low-level waste and mixed low-level waste at the Hanford Low-Level Waste Burial Grounds in accordance with the requirements of DOE Order 435.1, Radioactive Waste Management. To partially satisfy these requirements, performance assessment analyses were completed and approved. DOE Order 435.1 also requires continuing data collection to increase confidence in the critical assumptions used in these analyses to characterize the operational features of the disposal facility that are reliedmore » on to satisfy the performance objectives identified in the order. Cement-based solidification and stabilization is considered for hazardous waste disposal because it is easily done and cost-efficient. One critical assumption is that concrete will be used as a waste form or container material at the Hanford Site to control and minimize the release of radionuclide constituents in waste into the surrounding environment. Concrete encasement would contain and isolate the waste packages from the hydrologic environment and act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The radionuclides iodine-129, selenium-75, technetium-99, and uranium-238 have been identified as long-term dose contributors (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, these constituents of potential concern may be released from the encased concrete by mass flow and/or diffusion and migrate into the surrounding subsurface environment (Serne et al. 1989; 1992; 1993a, b; 1995). Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. Each of the test methods performed throughout the lifetime of the project has focused on different aspects of the concrete waste form weathering process. Diffusion of different analytes [technetium-99 (Tc-99), iodine-125 (I-125), stable iodine (I), uranium (U), and rhenium (Re)] has been quantified from experiments under both saturated and unsaturated conditions. The water-saturated conditions provide a conservative estimate of the concrete’s performance in situ, and the unsaturated conditions provide a more accurate estimate of the diffusion of contaminants from the concrete.« less

Uptake and transport of radioactive nickel and cadmium into three vegetables after wet aerial contamination.

PubMed

Fismes, Joëlle; Echevarria, Guillaume; Leclerc-Cessac, Elisabeth; Morel, Jean Louis

2005-01-01

Knowledge of radionuclide or trace element retention and translocation to plants following an aerial contamination event, for example, sprinkling with contaminated water, is necessary for the evaluation of human exposure through consumption of contaminated vegetables. The fate of 63Ni and 109Cd in all plant parts of three different vegetables after wet deposition on leaves or on fruits was studied. Lettuce (Lactuca sativa L.), radish (Raphanus sativus L.), and bean (Phaseolus vulgaris L.) grown under controlled conditions in a growth chamber were contaminated with 63Ni and 109Cd either on leaves, by means of two different contamination methods (a single early contamination and a repetitive one), or on bean husks (third contamination method: a single contamination at a late stage). Spiked and nonspiked organs were harvested at maturity and radionuclide contents were measured. The fraction retained was on average 56% of the initially administered doses of 63Ni and 87% of 109Cd. The leaf-to-other organ translocation factor was considerably higher for 63Ni (on average 43% of retained radioactivity) than for 109Cd (8%). Nickel-63 migrated throughout the whole plant following foliar contamination, and mainly toward young leaves, seeds in formation, and sink organs, whereas 109Cd migrated to a much lesser extent and only to the organs that were closest to the spiked one, and not at all into fruit. After a fruit contamination event, both radionuclides were translocated into the seeds of spiked fruits. Radionuclide retention and translocation were not affected by plant species, but principally by the type of organ contaminated.

Development of a sorption data base for the cementitious near-field of a repository for radioactive waste

NASA Astrophysics Data System (ADS)

Wieland, E.; Bradbury, M. H.; van Loon, L.

2003-01-01

The migration of radionuclides within a repository for radioactive waste is retarded due to interaction with the engineered barrier system. Sorption processes play a decisive role in the retardation of radionuclides in the repository environment, and thus, the development of sorption data bases (SDBs) is an important task and an integral part of performance assessment. The methodology applied in the development of a SDB for the cementitious near-field of a repository for long-lived intermediate-level waste is presented in this study. The development of such a SDB requires knowledge of the chemical conditions of the near-field and information on the uptake process of radionuclides by hardened cement paste. The principles upon which the selection of the “best available” laboratory sorption values is based are outlined. The influence of cellulose degradation products, cement additives and cement-derived colloids on the sorption behaviour of radionuclides is addressed in conjunction with the development of the SDB.

Diffusion of Radionuclides in Concrete and Soil

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V.; Wellman, Dawn M.; Bovaird, Chase C.

2012-04-25

One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Such concrete encasement would contain and isolate the waste packages from the hydrologic environment and would act as an intrusion barrier. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion and move into the surrounding subsurface environment. Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability ofmore » the surrounding soil to retard radionuclide migration. The objective of our study was to measure the diffusivity of Re, Tc and I in concrete containment and the surrounding vadose zone soil. Effects of carbonation, presence of metallic iron, and fracturing of concrete and the varying moisture contents in soil on the diffusivities of Tc and I were evaluated.« less

Phosphate-Mediated Remediation of Metals and Radionuclides

DOE PAGES

Martinez, Robert J.; Beazley, Melanie J.; Sobecky, Patricia A.

2014-01-01

Worldwide industrialization activities create vast amounts of organic and inorganic waste streams that frequently result in significant soil and groundwater contamination. Metals and radionuclides are of particular concern due to their mobility and long-term persistence in aquatic and terrestrial environments. As the global population increases, the demand for safe, contaminant-free soil and groundwater will increase as will the need for effective and inexpensive remediation strategies. Remediation strategies that include physical and chemical methods (i.e., abiotic) or biological activities have been shown to impede the migration of radionuclide and metal contaminants within soil and groundwater. However, abiotic remediation methods are oftenmore » too costly owing to the quantities and volumes of soils and/or groundwater requiring treatment. The in situ sequestration of metals and radionuclides mediated by biological activities associated with microbial phosphorus metabolism is a promising and less costly addition to our existing remediation methods. This review highlights the current strategies for abiotic and microbial phosphate-mediated techniques for uranium and metal remediation.« less

Evaluation of the Hydrologic Source Term from Underground Nuclear Tests on Pahute Mesa at the Nevada Test Site: The CHESHIRE Test

DOE Office of Scientific and Technical Information (OSTI.GOV)

Pawloski, G A; Tompson, A F B; Carle, S F

The objectives of this report are to develop, summarize, and interpret a series of detailed unclassified simulations that forecast the nature and extent of radionuclide release and near-field migration in groundwater away from the CHESHIRE underground nuclear test at Pahute Mesa at the NTS over 1000 yrs. Collectively, these results are called the CHESHIRE Hydrologic Source Term (HST). The CHESHIRE underground nuclear test was one of 76 underground nuclear tests that were fired below or within 100 m of the water table between 1965 and 1992 in Areas 19 and 20 of the NTS. These areas now comprise the Pahutemore » Mesa Corrective Action Unit (CAU) for which a separate subregional scale flow and transport model is being developed by the UGTA Project to forecast the larger-scale migration of radionuclides from underground tests on Pahute Mesa. The current simulations are being developed, on one hand, to more fully understand the complex coupled processes involved in radionuclide migration, with a specific focus on the CHESHIRE test. While remaining unclassified, they are as site specific as possible and involve a level of modeling detail that is commensurate with the most fundamental processes, conservative assumptions, and representative data sets available. However, the simulation results are also being developed so that they may be simplified and interpreted for use as a source term boundary condition at the CHESHIRE location in the Pahute Mesa CAU model. In addition, the processes of simplification and interpretation will provide generalized insight as to how the source term behavior at other tests may be considered or otherwise represented in the Pahute Mesa CAU model.« less

Managing previously disposed waste to today's standards

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1990-01-01

A Radioactive Waste Management Complex (RWMC) was established at the Idaho National Engineering Laboratory (INEL) in 1952 for controlled disposal of radioactive waste generated at the INEL. Between 1954 and 1970 waste characterized by long lived, alpha emitting radionuclides from the Rocky Flats Plant was also buried at this site. Migration of radionuclides and other hazardous substances from the buried Migration of radionuclides and other hazardous substances from the buried waste has recently been detected. A Buried Waste Program (BWP) was established to manage cleanup of the buried waste. This program has four objectives: (1) determine contaminant sources, (2) determinemore » extent of contamination, (3) mitigate migration, and (4) recommend an alternative for long term management of the waste. Activities designed to meet these objectives have been under way since the inception of the program. The regulatory environment governing these activities is evolving. Pursuant to permitting activities under the Resource Conservation and Recovery Act (RCRA), the Department of Energy (DOE) and the Environmental Protection Agency (EPA) entered into a Consent Order Compliance Agreement (COCA) for cleanup of past practice disposal units at the INEL. Subsequent to identification of the RWMC as a release site, cleanup activities proceeded under dual regulatory coverage of RCRA and the Atomic Energy Act. DOE, EPA, and the State of Idaho are negotiating a RCRA/Comprehensive Environmental Response, Compensation, and Liability Act (CERCLA) Interagency Agreement (IAG) for management of waste disposal sites at the INEL as a result of the November 1989 listing of the INEL on the National Priority List (NPL). Decision making for selection of cleanup technology will be conducted under the CERCLA process supplemented as required to meet the requirements of the National Environmental Policy Act (NEPA). 7 figs.« less

Geochemical effects on the behavior of LLW radionuclides in soil/groundwater environments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krupka, K.M.; Sterne, R.J.

1995-12-31

Assessing the migration potential of radionuclides leached from low-level radioactive waste (LLW) and decommissioning sites necessitates information on the effects of sorption and precipitation on the concentrations of dissolved radionuclides. Such an assessment requires that the geochemical processes of aqueous speciation, complexation, oxidation/reduction, and ion exchange be taken into account. The Pacific Northwest National Laboratory (PNNL) is providing technical support to the U.S. Nuclear Regulatory Commission (NRC) for defining the solubility and sorption behavior of radionuclides in soil/ground-water environments associated with engineered cementitious LLW disposal systems and decommissioning sites. Geochemical modeling is being used to predict solubility limits for radionuclidesmore » under geochemical conditions associated with these environments. The solubility limits are being used as maximum concentration limits in performance assessment calculations describing the release of contaminants from waste sources. Available data were compiled regarding the sorption potential of radionuclides onto {open_quotes}fresh{close_quotes} cement/concrete where the expected pH of the cement pore waters will equal to or exceed 10. Based on information gleaned from the literature, a list of preferred minimum distribution coefficients (Kd`s) was developed for these radionuclides. The K{sub d} values are specific to the chemical environments associated with the evolution of the compositions of cement/concrete pore waters.« less

Assessment of potential migration of radionuclides and trace elements from the White Mesa uranium mill to the Ute Mountain Ute Reservation and surrounding areas, southeastern Utah

USGS Publications Warehouse

Naftz, David L.; Ranalli, Anthony J.; Rowland, Ryan C.; Marston, Thomas M.

2011-01-01

In 2007, the Ute Mountain Ute Tribe requested that the U.S. Environmental Protection Agency and U.S. Geological Survey conduct an independent evaluation of potential offsite migration of radionuclides and selected trace elements associated with the ore storage and milling process at an active uranium mill site near White Mesa, Utah. Specific objectives of this study were (1) to determine recharge sources and residence times of groundwater surrounding the mill site, (2) to determine the current concentrations of uranium and associated trace elements in groundwater surrounding the mill site, (3) to differentiate natural and anthropogenic contaminant sources to groundwater resources surrounding the mill site, (4) to assess the solubility and potential for offsite transport of uranium-bearing minerals in groundwater surrounding the mill site, and (5) to use stream sediment and plant material samples from areas surrounding the mill site to identify potential areas of offsite contamination and likely contaminant sources.

Colloid facilitated transport of lanthanides through discrete fractures in chalk

NASA Astrophysics Data System (ADS)

Tran, Emily; Klein Ben-David, Ofra; Teutsch, Nadya; Weisbrod, Noam

2015-04-01

Geological disposal of high-level radioactive waste is the internationally agreed-upon, long term solution for the disposal of long lived radionuclides and spent fuel. Eventually, corrosion of the waste canisters may lead to leakage of their hazardous contents, and the radionuclides can ultimately make their way into groundwater and pose a threat to the biosphere. Engineered bentonite barriers placed around nuclear waste repositories are generally considered sufficient to impede the transport of radionuclides from their storage location to the groundwater. However, colloidal-sized mobile bentonite particles eroding from these barriers have come under investigation as a potential transport vector for radionuclides sorbed to them. In addition, the presence of organic matter in groundwater has been shown to additionally facilitate the uptake of radionuclides by the clay colloids. This study aims to evaluate the transport behaviors of radionuclides in colloid-facilitated transport through a fractured chalk matrix and under geochemical conditions representative of the Negev desert, Israel. Lanthanides are considered an acceptable substitute to actinides for research on radionuclide transportation due to their similar chemical behavior. In this study, the migration of Ce both with and without colloidal particles was explored and compared to the migration of a conservative tracer (bromide). Tracer solutions containing known concentrations of Ce, bentonite colloids, humic acid and bromide were prepared in a matrix solution containing salt concentrations representative of that of the average rain water found in the Negev. These solutions were then injected into a flow system constructed around a naturally fractured chalk core. Samples were analyzed for Ce and Br using ICP-MS, and colloid concentrations were determined using spectrophotographic analysis. Breakthrough curves comparing the rates of transportation of each tracer were obtained, allowing for comparison of transport rates and calculation of overall tracer recovery. Preliminary results suggest that mobility of Ce as a solute is negligible, and in experiments conducted without bentonite colloids, the 2% of the Ce that was recovered during the experiments travelled as "intrinsic" colloids in the form of Ce2(CO3)3-6H2O precipitate. However, the total recovery of the Ce increased to 9% when it was injected into the core in the presence of bentonite colloids and 13% when both bentonite and the carbonate precipitate colloids were injected. In addition, the maximum relative concentration (C/C0) of the Ce in the samples from the experiments conducted without bentonite colloids is about 0.002, whereas that of the experiments conducted in the presence of bentonite colloids reaches almost 0.2. This indicates that colloid presence does indeed markedly increase the mobility of radionuclides through fractured chalk matrices and should therefore be considered in models representing transport of radionuclide waste originating from nuclear repositories.

Integration of genotoxicity and population genetic analyses in kangaroo rats (Dipodomys merriami) exposed to radionuclide contamination at the Nevada Test Site, USA

USGS Publications Warehouse

Theodorakis, Christopher W.; Bickham, John W.; Lamb, Trip; Medica, Philip A.; Lyne, T. Barrett

2001-01-01

We examined effects of radionuclide exposure at two atomic blast sites on kangaroo rats (Dipodomys merriami) at the Nevada Test Site, Nevada, USA, using genotoxicity and population genetic analyses. We assessed chromosome damage by micronucleus and flow cytometric assays and genetic variation by randomly amplified polymorphic DNA (RAPD) and mitochondrial DNA (mtDNA) analyses. The RAPD analysis showed no population structure, but mtDNA exhibited differentiation among and within populations. Genotoxicity effects were not observed when all individuals were analyzed. However, individuals with mtDNA haplotypes unique to the contaminated sites had greater chromosomal damage than contaminated-site individuals with haplotypes shared with reference sites. When interpopulation comparisons used individuals with unique haplotypes, one contaminated site had greater levels of chromosome damage than one or both of the reference sites. We hypothesize that shared-haplotype individuals are potential migrants and that unique-haplotype individuals are potential long-term residents. A parsimony approach was used to estimate the minimum number of migration events necessary to explain the haplotype distributions on a phylogenetic tree. The observed predominance of migration events into the contaminated sites supported our migration hypothesis. We conclude the atomic blast sites are ecological sinks and that immigration masks the genotoxic effects of radiation on the resident populations.

Regulatory Technology Development Plan - Sodium Fast Reactor. Mechanistic Source Term - Metal Fuel Radionuclide Release

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grabaskas, David; Bucknor, Matthew; Jerden, James

2016-02-01

The development of an accurate and defensible mechanistic source term will be vital for the future licensing efforts of metal fuel, pool-type sodium fast reactors. To assist in the creation of a comprehensive mechanistic source term, the current effort sought to estimate the release fraction of radionuclides from metal fuel pins to the primary sodium coolant during fuel pin failures at a variety of temperature conditions. These release estimates were based on the findings of an extensive literature search, which reviewed past experimentation and reactor fuel damage accidents. Data sources for each radionuclide of interest were reviewed to establish releasemore » fractions, along with possible release dependencies, and the corresponding uncertainty levels. Although the current knowledge base is substantial, and radionuclide release fractions were established for the elements deemed important for the determination of offsite consequences following a reactor accident, gaps were found pertaining to several radionuclides. First, there is uncertainty regarding the transport behavior of several radionuclides (iodine, barium, strontium, tellurium, and europium) during metal fuel irradiation to high burnup levels. The migration of these radionuclides within the fuel matrix and bond sodium region can greatly affect their release during pin failure incidents. Post-irradiation examination of existing high burnup metal fuel can likely resolve this knowledge gap. Second, data regarding the radionuclide release from molten high burnup metal fuel in sodium is sparse, which makes the assessment of radionuclide release from fuel melting accidents at high fuel burnup levels difficult. This gap could be addressed through fuel melting experimentation with samples from the existing high burnup metal fuel inventory.« less

Oak Ridge Reservation Annual Site environmental report summary for 1994

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1995-09-01

This document presents a summary of the information collected for the Oak Ridge Reservation 1994 site environmental report. Topics discussed include: Oak Ridge Reservation mission; ecology; environmental laws; community participation; environmental restoration; waste management; radiation effects; chemical effects; risk to public; environmental monitoring; and radionuclide migration.

Fate and transport of radionuclides in soil-water environment. Review.

NASA Astrophysics Data System (ADS)

Konoplev, Aleksei

2017-04-01

The ease in which radionuclides move through the environment and are taken up by plants and animals is governed by their chemical forms and by site-specific environmental characteristics. The objective of this paper is to review basic mechanisms of the behavior of radiocesium and radiostrontium in the environment after the nuclear accident. Our understanding of radionuclide's speciation and migration processes seems to be adequate and explains similarities and differences of radiocesium (r-Cs) behavior in the environment after Fukushima and Chernobyl accidents. Climate and geographical conditions in Fukushima Prefecture of Japan and Chernobyl's near-field zone are obviously different. In particular, precipitation differs substantially, with the annual average for Fukushima being about 3 times higher than at Chernobyl. The landscapes and soils also differ significantly. What is more, the speciation of r-Cs in the releases was distinct (large fraction of radionuclides was deposited as fuel particles in 30-km zone around Chernobyl NPP, while in Fukushima radiocesium is mostly part of condensation particles including glassy hot particles). Radiocesium (r-Cs) in the environment is strongly bound to soil and sediment particles containing micaceous clay minerals (illite, vermiculite, etc.), which is associated with two basic processes - high selective reversible sorption and fixation. The r-Cs distribution coefficient Kd in Fukushima rivers was found to be 1-2 orders of magnitude higher than corresponding values for rivers and surface runoff of Chernobyl area. This is indicative of higher ability of Fukushima soils and sediments to bind r-Cs. Dissolved r-Cs wash-off for Fukushima river watersheds is essentially slower than those for Chernobyl. However, steeper slopes and higher precipitation in Fukushima area cause higher erosion and higher particulate r-Cs wash-off. For a comparable time after the accident the total r-Cs wash-off from contaminated catchments in Fukushima is up to one order of magnitude higher than in Chernobyl. Long-term dynamics of radionuclide concentrations in rivers is approached from the standpoint of basic mechanisms of radionuclide sorption-desorption, fixation, vertical migration in catchment soils. Corresponding semi-empirical models are presented and discussed. For the Chernobyl case, radiostrontium (r-Sr) was shown to be more mobile and moving faster in dissolved state with surface runoff and river water in comparison with r-Cs. Similar pattern was observed for Mayak area in South Ural (Russia), where r-Sr was traced up to 1500 km away from the release point migrating through Techa-Iset'-Tobol-Irtysh-Ob' river system. On the other hand, r-Cs bound to clay particles settles down in Techa river reservoirs and is transported with river water only insignificantly. For the first 3 years after the accident vertical migration of r-Cs in soils of Fukushima catchments was found to be faster than in Chernobyl due to higher air temperature, higher precipitation and higher biological activity in top soil. However, with time this process slows down because of higher r-Cs retardation in Fukushima soils. In Fukushima case, extreme floods during typhoons lead to substantial reduction in dose rate on floodplain areas due to sedimentation of relatively clean material and burial of contaminated top soil layer. In general, due to higher precipitation, higher temperatures and higher biological activities in soils, self-purification of the environment and natural attenuation in Fukushima is essentially faster than in Chernobyl area.

WORKSHOP ON DEVELOPMENT OF RADIONUCLIDE GETTERS FOR THE YUCCA MOUNTAIN WASTE REPOSITORY

DOE Office of Scientific and Technical Information (OSTI.GOV)

K.C. Holt

One of the important that the U.S. Department of Energy (DOE) is currently undertaking is the development of a high-level nuclear waste repository to be located at Yucca Mountain, Nevada. Concern is generated by the Yucca Mountain Project (YMP) is due to potential releases as groundwater contamination, as described in the Total System Performance Assessment (TSPA). The dose to an off-site individual using this groundwater for drinking and irrigation is dominated by four radionuclides: Tc-99, I-127, Np-237, and U-238. Ideally, this dose would be limited to a single radionuclide, U-238; in other words, YMP would resemble a uranium ore body,more » a common geologic feature in the Western U.S. For this reason and because of uncertainties in the behavior of Tc-99, I-127, and Np-237, it would be helpful to limit the amount of Tc, I, and Np leaving the repository, which would greatly increase the confidence in the long-term performance of YMP. An approach to limiting the migration of Tc, I, and Np that is complementary to the existing YMP repository design plans is to employ sequestering agents or ''getters'' for these radionuclides such that their migration is greatly hindered, thus decreasing the amount of radionuclide leaving the repository. Development of such getters presents a number of significant challenges. The getter must have a high affinity and high selectivity for the radionuclide in question since there is approximately a 20- to 50-fold excess of other fission products and a 1000-fold excess of uranium in addition to the ions present in the groundwater. An even greater challenge is that the getters must function over a period greater than the half-life of the radionuclide (greater than 5 half-lives would be ideal). Typically, materials with a high affinity for Tc, I, or Np are not sufficiently durable. For example, strong-base ion exchange resins have a very high affinity for TcO{sub 4}{sup -} but are not expected to be durable. On the other hand, durable materials, such as hydrotalcite, do not have sufficient affinity to be useful getters. Despite these problems, the great increase in the repository performance and corresponding decrease in uncertainty promised by a useful getter has generated significant interest in these materials. This report is the result a workshop sponsored by the Office of Civilian Radioactive Waste Management and Office of Science and Technology and International of the DOE to assess the state of research in this field.« less

Groundwater monitoring in the Savannah River Plant Low Level Waste Burial Ground

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carlton, W.H.

1983-12-31

This document describes chemical mechanisms that may affect trace-level radionuclide migration through acidic sandy clay soils in a humid environment, and summarizes the extensive chemical and radiochemical analyses of the groundwater directly below the SRP Low-Level Waste (LLW) Burial Ground (643-G). Anomalies were identified in the chemistry of individual wells which appear to be related to small amounts of fission product activity that have reached the water table. The chemical properties which were statistically related to trace level transport of Cs-137 and Sr-90 were iron, potassium, sodium and calcium. Concentrations on the order of 100 ppM appear sufficient to affectmore » nuclide migration. Several complexation mechanisms for plutonium migration were investigated.« less

10 CFR 60.134 - Design of seals for shafts and boreholes.

Code of Federal Regulations, 2014 CFR

2014-01-01

... boreholes shall be designed so that following permanent closure they do not become pathways that compromise... pathway for groundwater to contact the waste packages or (2) For radionuclide migration through existing pathways. [48 FR 28222, June 21, 1983, as amended at 50 FR 29648, July 22, 1985] Design Criteria for the...

10 CFR 60.134 - Design of seals for shafts and boreholes.

Code of Federal Regulations, 2012 CFR

2012-01-01

... boreholes shall be designed so that following permanent closure they do not become pathways that compromise... pathway for groundwater to contact the waste packages or (2) For radionuclide migration through existing pathways. [48 FR 28222, June 21, 1983, as amended at 50 FR 29648, July 22, 1985] Design Criteria for the...

10 CFR 60.134 - Design of seals for shafts and boreholes.

Code of Federal Regulations, 2013 CFR

2013-01-01

... boreholes shall be designed so that following permanent closure they do not become pathways that compromise... pathway for groundwater to contact the waste packages or (2) For radionuclide migration through existing pathways. [48 FR 28222, June 21, 1983, as amended at 50 FR 29648, July 22, 1985] Design Criteria for the...

Trace levels of Fukushima disaster radionuclides in East Pacific albacore.

PubMed

Neville, Delvan R; Phillips, A Jason; Brodeur, Richard D; Higley, Kathryn A

2014-05-06

The Fukushima Daiichi power station released several radionuclides into the Pacific following the March 2011 earthquake and tsunami. A total of 26 Pacific albacore (Thunnus alalunga) caught off the Pacific Northwest U.S. coast between 2008 and 2012 were analyzed for (137)Cs and Fukushima-attributed (134)Cs. Both 2011 (2 of 2) and several 2012 (10 of 17) edible tissue samples exhibited increased activity concentrations of (137)Cs (234-824 mBq/kg of wet weight) and (134)Cs (18.2-356 mBq/kg of wet weight). The remaining 2012 samples and all pre-Fukushima (2008-2009) samples possessed lower (137)Cs activity concentrations (103-272 mBq/kg of wet weight) with no detectable (134)Cs activity. Age, as indicated by fork length, was a strong predictor for both the presence and concentration of (134)Cs (p < 0.001). Notably, many migration-aged fish did not exhibit any (134)Cs, suggesting that they had not recently migrated near Japan. None of the tested samples would represent a significant change in annual radiation dose if consumed by humans.

NNSS Soils Monitoring: Plutonium Valley (CAU366) FY2012

DOE Office of Scientific and Technical Information (OSTI.GOV)

Miller, Julianne J.; Mizell, Steve A.; Nikolich, George

2013-01-01

The U.S. Department of Energy (DOE) National Nuclear Security Administration (NNSA), Nevada Site Office (NSO), Environmental Restoration Soils Activity has authorized the Desert Research Institute (DRI) to conduct field assessments of potential sediment transport of contaminated soil from Corrective Action Unit (CAU) 366, Area 11 Plutonium Valley Dispersion Sites Contamination Area (CA) during precipitation runoff events. Field measurements at the T-4 Atmospheric Test Site (CAU 370) suggest that radionuclide-contaminated soils may have migrated along a shallow ephemeral drainage that traverses the site (NNSA/NSO, 2009). (It is not entirely clear how contaminated soils got into their present location at the T-4more » Site, but flow to the channel has been redirected and the contamination does not appear to be migrating at present.) Aerial surveys in selected portions of the Nevada National Security Site (NNSS) also suggest that radionuclide-contaminated soils may be migrating along ephemeral channels in Areas 3, 8, 11, 18, and 25 (Colton, 1999). In Area 11, several low-level airborne surveys of the Plutonium Valley Dispersion Sites (CAU 366) show plumes of Americium 241 (Am-241) extending along ephemeral channels (Figure 1, marker numbers 5 and 6) below Corrective Action Site (CAS) 11-23-03 (marker number 3) and CAS 11 23-04 (marker number 4) (Colton, 1999). Plutonium Valley in Area 11 of the NNSS was selected for the study because of the aerial survey evidence suggesting downstream transport of radionuclide-contaminated soil. The aerial survey (Figure 1) shows a well defined finger of elevated radioactivity (marker number 5) extending to the southwest from the southernmost detonation site (marker number 4). This finger of contamination overlies a drainage channel mapped on the topographic base map used for presentation of the survey data suggesting surface runoff as a likely cause of the contaminated area. Additionally, instrumenting sites strongly suspected of conveying soil from areas of surface contamination offers the most efficient means to confirm that surface runoff may transport radioactive contamination as a result of ambient precipitation/runoff events. Closure plans being developed for the CAUs on the NNSS may include post-closure monitoring for possible release of radioactive contaminants. Determining the potential for transport of radionuclide-contaminated soils under ambient meteorological conditions will facilitate an appropriate closure design and post-closure monitoring program.« less

Environmental evolution records reflected by radionuclides in the sediment of coastal wetlands: A case study in the Yellow River Estuary wetland.

PubMed

Wang, Qidong; Song, Jinming; Li, Xuegang; Yuan, Huamao; Li, Ning; Cao, Lei

2016-10-01

Vertical profiles of environmental radionuclides ( 210 Pb, 137 Cs, 238 U, 232 Th, 226 Ra and 4 0 K) in a sediment core (Y1) of the Yellow River Estuary wetland were investigated to assess whether environmental evolutions in the coastal wetland could be recorded by the distributions of radionuclides. Based on 210 Pb and 137 Cs dating, the average sedimentation rate of core Y1 was estimated to be 1.0 cm y -1 . Vertical distributions of natural radionuclides ( 238 U, 232 Th, 226 Ra and 40 K) changed dramatically, reflecting great changes in sediment input. Concentrations of 238 U, 232 Th, 226 Ra and 40 K all had significant positive relationships with organic matter and clay content, but their distributions were determined by different factors. Factor analysis showed that 238 U was determined by the river sediment input while 226 Ra was mainly affected by the seawater erosion. Environmental changes such as river channel migrations and sediment discharge variations could always cause changes in the concentrations of radionuclides. High concentrations of 238 U and 226 Ra were consistent with high accretion rate. Frequent seawater intrusion decreased the concentration of 226 Ra significantly. The value of 238 U/ 226 Ra tended to be higher when the sedimentation rate was low and tide intrusion was frequent. In summary, environmental evolutions in the estuary coastal wetland could be recorded by the vertical profiles of natural radionuclides. Copyright © 2016 Elsevier Ltd. All rights reserved.

Microbial impacts on 99mTc migration through sandstone under highly alkaline conditions relevant to radioactive waste disposal.

PubMed

Smith, Sarah L; Boothman, Christopher; Williams, Heather A; Ellis, Beverly L; Wragg, Joanna; West, Julia M; Lloyd, Jonathan R

2017-01-01

Geological disposal of intermediate level radioactive waste in the UK is planned to involve the use of cementitious materials, facilitating the formation of an alkali-disturbed zone within the host rock. The biogeochemical processes that will occur in this environment, and the extent to which they will impact on radionuclide migration, are currently poorly understood. This study investigates the impact of biogeochemical processes on the mobility of the radionuclide technetium, in column experiments designed to be representative of aspects of the alkali-disturbed zone. Results indicate that microbial processes were capable of inhibiting 99m Tc migration through columns, and X-ray radiography demonstrated that extensive physical changes had occurred to the material within columns where microbiological activity had been stimulated. The utilisation of organic acids under highly alkaline conditions, generating H 2 and CO 2 , may represent a mechanism by which microbial processes may alter the hydraulic conductivity of a geological environment. Column sediments were dominated by obligately alkaliphilic H 2 -oxidising bacteria, suggesting that the enrichment of these bacteria may have occurred as a result of H 2 generation during organic acid metabolism. The results from these experiments show that microorganisms are able to carry out a number of processes under highly alkaline conditions that could potentially impact on the properties of the host rock surrounding a geological disposal facility for intermediate level radioactive waste. Copyright © 2016. Published by Elsevier B.V.

Application of the migration models implemented in the decision system MOIRA-PLUS to assess the long term behaviour of (137)Cs in water and fish of the Baltic Sea.

PubMed

Monte, Luigi

2014-08-01

This work presents and discusses the results of an application of the contaminant migration models implemented in the decision support system MOIRA-PLUS to simulate the time behaviour of the concentrations of (137)Cs of Chernobyl origin in water and fish of the Baltic Sea. The results of the models were compared with the extensive sets of highly reliable empirical data of radionuclide contamination available from international databases and covering a period of, approximately, twenty years. The model application involved three main phases: a) the customisation performed by using hydrological, morphometric and water circulation data obtained from the literature; b) a blind test of the model results, in the sense that the models made use of default values of the migration parameters to predict the dynamics of the contaminant in the environmental components; and c) the adjustment of the model parameter values to improve the agreement of the predictions with the empirical data. The results of the blind test showed that the models successfully predicted the empirical contamination values within the expected range of uncertainty of the predictions (confidence level at 68% of approximately a factor 2). The parameter adjustment can be helpful for the assessment of the fluxes of water circulating among the main sub-basins of the Baltic Sea, substantiating the usefulness of radionuclides to trace the movement of masses of water in seas. Copyright © 2014 Elsevier Ltd. All rights reserved.

Environmental risks of radioactive discharges from a low-level radioactive waste disposal site at Dessel, Belgium.

PubMed

Batlle, J Vives I; Sweeck, L; Wannijn, J; Vandenhove, H

2016-10-01

The potential radiological impact of releases from a low-level radioactive waste (Category A waste) repository in Dessel, Belgium on the local fauna and flora was assessed under a reference scenario for gradual leaching. The potential impact situations for terrestrial and aquatic fauna and flora considered in this study were soil contamination due to irrigation with contaminated groundwater from a well at 70 m from the repository, contamination of the local wetlands receiving the highest radionuclide flux after migration through the aquifer and contamination of the local river receiving the highest radionuclide flux after migration through the aquifer. In addition, an exploratory study was carried out for biota residing in the groundwater. All impact assessments were performed using the Environmental Risk from Ionising Contaminants: Assessment and Management (ERICA) tool. For all scenarios considered, absorbed dose rates to biota were found to be well below the ERICA 10 μGy h -1 screening value. The highest dose rates were observed for the scenario where soil was irrigated with groundwater from the vicinity of the repository. For biota residing in the groundwater well, a few dose rates were slightly above the screening level but significantly below the dose rates at which the smallest effects are observed for those relevant species or groups of species. Given the conservative nature of the assessment, it can be concluded that manmade radionuclides deposited into the environment by the near surface disposal of category A waste at Dessel do not have a significant radiological impact to wildlife. Copyright © 2016 Elsevier Ltd. All rights reserved.

Geotechnical, geological, and selected radionuclide retention characteristics of the radioactive waste disposal site near the Farallon Islands

USGS Publications Warehouse

Booth, J.S.; Winters, W.J.; Poppe, L.J.; Neiheisel, J.; Dyer, R.S.

1989-01-01

A geotechnical and geological investigation of the Farallon Islands low-level radioactive waste (LLW) disposal area was conducted to qualitatively assess the host sediments' relative effectiveness as a barrier to radionuclide migration, to estimate the portion of the barrier that is in contact with the waste packages at the three primary disposal sites, and to provide a basic physical description of the sediments. Box cores recovered from within the general disposal area at depths of 500, 1000, and 1500 m were subcored to provide samples (~30 cm in length) for detailed descriptions, textural and mineralogical analyses, and a suite of geotechnical tests (index property, CRS consolidation, and CIU triaxial compression). -from Authors

VERTICAL MIGRATION OF RADIONUCLIDES IN THE VICINITY OF THE CHERNOBYL CONFINEMENT SHELTER

DOE Office of Scientific and Technical Information (OSTI.GOV)

Farfan, E.; Jannik, T.; Marra, J.

2011-10-01

Studies on vertical migration of Chernobyl-origin radionuclides in the 5-km zone of the Chernobyl Nuclear Power Plant (ChNPP) in the area of the Red Forest experimental site were completed. Measurements were made by gamma spectrometric methods using high purity germanium (HPGe) detectors with beryllium windows. Alpha-emitting isotopes of plutonium were determined by the measurement of the x-rays from their uranium progeny. The presence of {sup 60}Co, {sup 134,137}Cs, {sup 154,155}Eu, and {sup 241}Am in all soil layers down to a depth of 30 cm was observed. The presence of {sup 137}Cs and {sup 241}Am were noted in the area containingmore » automorphous soils to a depth of 60 cm. In addition, the upper soil layers at the test site were found to contain {sup 243}Am and {sup 243}Cm. Over the past ten years, the {sup 241}Am/{sup 137}Cs ratio in soil at the experimental site has increased by a factor of 3.4, nearly twice as much as would be predicted based solely on radioactive decay. This may be due to 'fresh' fallout emanating from the ChNPP Confinement Shelter.« less

Geologic and hydrologic characterization and evaluation of the Basin and Range Province relative to the disposal of high-level radioactive waste: Part I, Introduction and guidelines

USGS Publications Warehouse

Bedinger, M.S.; Sargent, Kenneth A.; Reed, J.E.

1984-01-01

The U.S. Geological Survey's program for geologic and hydrologic evaluation of physiographic provinces to identify areas potentially suitable for locating repository sites for disposal of high-level nuclear wastes was announced to the Governors of the eight States in the Basin and Range Province on May 5, 1981. Representatives of Arizona, California, Idaho, New Mexico, Nevada, Oregon, Texas, and Utah, were invited to cooperate with the Federal Government in the evaluation process. Each Governor was requested to nominate an Earth scientist to represent the State in a province working group composed of State and U.S. Geological Survey representatives. This report, Part I of a three-part report, provides the background, introduction and scope of the study. This part also includes a discussion of geologic and hydrologic guidelines that will be used in the evaluation process and illustrates geohydrologic environments and the effect of individual factors in providing multiple natural barriers to radionuclide migration.Part II is a reconnaissance characterization of the geologic and hydrologic factors to be used in the initial screening of the Basin and Range Province. Part III will be the initial evaluation of the Province and will identify regions that appear suitable for further study.The plan for study of the Province includes a stepwise screening process by which successively smaller land units are considered in increasing detail. Each step involves characterization of the geology and hydrology and selection of subunits for more intensive characterization. Selection of subunits for further study is by evaluation of geologic and hydrologic conditions following a set of guidelines. By representation on the Province Working Group, the States participate in a consultation and review role in: (1) Establishing geologic and hydrologic guidelines, and (2) characterizing and evaluating the Province. The States also participate in compilation of geologic and hydrologic data used in characterizing the Province.The current (1983) needs for a high-level radioactive waste repository include: (1) Disposal in a mined repository; (2) retrievability of the waste for as much as 50 years; and (3) confidence of isolation of the waste from the accessible environment. Isolation of the waste needs to be assured using geologic and hydrologic conditions that: (1) Minimize risk of inadvertent future intrusions by man; (2) minimize the possibility of disturbance by processes that would expose the waste or increase its mobility; and (3) provide a system of natural barriers to the migration of waste by ground water. The guidelines adopted by the Province Working Group are designed to provide a standard with which these conditions can be compared.The guidelines can be grouped into four principal categories: (1) Potential host media, (2) ground-water conditions, (3) tectonic conditions, and. (4) occurrence of natural resources. Ideally the host medium constitutes the first natural barrier to migration of radionculides. The host medium ideally should be a rock type that prevents or retards dissolution and transport of radionuclides. Rocks in both the saturated and unsaturated zones may have desirable characteristics for host media. Rocks-other than the host-in the ground-water flow path from the repository ideally should be major barriers to radionuclide migration. Confining beds of low permeability might be present to retard the rate of flow between more permeable beds. Additionally, sorption of radionuclides by materials such as clays and zeolites in the flow path can further retard the flow of radionuclides by several orders of magnitude. Tectonic conditions in an area should not present a probable cause for exhumation or increased mobility of radioactive waste. Natural resources are a factor for consideration because of the problem of future human intrusion and exposure to radioactivity in the quest for minerals, oil, gas, water, and geothermal resources.The ultimate evaluation of the suitability of a geohydrologic environment for developing a mined repository needs to assess all geologic and hydrologic characteristics and their interaction in providing confidence that a geohydrologic environment will effectively isolate radionuclides from human access. Several hypothetical settings with typical geohydrologic conditions in the Basin and Range Province are used to illustrate the effect of multiple barriers in the isolation of radionuclides.

Coupling of Nuclear Waste Form Corrosion and Radionuclide Transports in Presence of Relevant Repository Sediments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wall, Nathalie A.; Neeway, James J.; Qafoku, Nikolla P.

2015-09-30

Assessments of waste form and disposal options start with the degradation of the waste forms and consequent mobilization of radionuclides. Long-term static tests, single-pass flow-through tests, and the pressurized unsaturated flow test are often employed to study the durability of potential waste forms and to help create models that predict their durability throughout the lifespan of the disposal site. These tests involve the corrosion of the material in the presence of various leachants, with different experimental designs yielding desired information about the behavior of the material. Though these tests have proved instrumental in elucidating various mechanisms responsible for material corrosion,more » the chemical environment to which the material is subject is often not representative of a potential radioactive waste repository where factors such as pH and leachant composition will be controlled by the near-field environment. Near-field materials include, but are not limited to, the original engineered barriers, their resulting corrosion products, backfill materials, and the natural host rock. For an accurate performance assessment of a nuclear waste repository, realistic waste corrosion experimental data ought to be modeled to allow for a better understanding of waste form corrosion mechanisms and the effect of immediate geochemical environment on these mechanisms. Additionally, the migration of radionuclides in the resulting chemical environment during and after waste form corrosion must be quantified and mechanisms responsible for migrations understood. The goal of this research was to understand the mechanisms responsible for waste form corrosion in the presence of relevant repository sediments to allow for accurate radionuclide migration quantifications. The rationale for this work is that a better understanding of waste form corrosion in relevant systems will enable increased reliance on waste form performance in repository environments and potentially decrease the need for expensive engineered barriers.Our current work aims are 1) quantifying and understanding the processes associated with glass alteration in contact with Fe-bearing materials; 2) quantifying and understanding the processes associated with glass alteration in presence of MgO (example of engineered barrier used in WIPP); 3) identifying glass alteration suppressants and the processes involved to reach glass alteration suppression; 4) quantifying and understanding the processes associated with Saltstone and Cast Stone (SRS and Hanford cementitious waste forms) in various representative groundwaters; 5) investigating positron annihilation as a new tool for the study of glass alteration; and 6) quantifying and understanding the processes associated with glass alteration under gamma irradiation.« less

Investigation of radionuclide distribution in soil particles in different landscapes

NASA Astrophysics Data System (ADS)

Shkinev, V. M.; Korobova, E. M.; Linnik, V. G.

2012-04-01

Russian and foreign publications have been analyzed for understanding the role of micro- and nano- particles in distribution and migration of technogenic elements in soils in different landscape conditions. A technique for application of various fractionation methods to separate and study -particles of different size down to micro- and nano-level has been developed. The dry sit method on the first stage of particle separation is recommend to be followed by the membrane filtration method. For obtaining more comprehensive information, combinations of fractionation technique should be chosen taking into account that (1) the efficiency of particles' separation using subsequent technique would be higher than using the preceding one; (2) separation methods should preferably be based on different principles (separation according size, density, charge etc.); (3) initial fractionation should separate particles according to their size, that makes possible to create an even scale for various samples. A study of distribution and balance of technogenic radionuclides' in soil particles of the size intervals 1.0—0.25, 0.25-0.1, 0.1-0.05, 0.05-0.01, 0.01-0.005, 0.005-0.001 and <0.001 mm in the Yenisey flood plain landscapes proved a significant role of both the particle size and the portion of contaminated fraction in contribution to the total radionuclide inventory in the soil layers. Contribution of the silt particles (0,05-0,01 mm) to Cs-137 contamination ranged from 26 to 33,8%, 45% maximum due to "optimal" combination of both factors. Clay fraction was responsible for approximately 30% of Cs-137 contained in soil horizons due to higher sorption capacity. Relatively high correlation between the activity of 152,154Eu and 60 and the content of silt and clay allowed suggesting their incorporation mainly in clay fraction. Selected experimental plots near the Kola NPP (northern taiga) were used to compare soil particles (fractions 140-71; 71-40 and < 40 µm) in their ability to concentrate technogenic radionuclides and heavy metals. Maximum radioactivity found in soil litter appeared to be related to the Chernobyl contamination. Concentration of s-137 was higher in small size fractions. Obtained results were considered to be useful for understanding of radionuclide migration in the environment and decision making on radioecological monitoring, rehabilitation and landuse in the contaminated areas.

Principles of landscape-geochemical studies in the zones contaminated by technogenical radionuclides for ecological and geochemical mapping

NASA Astrophysics Data System (ADS)

Korobova, Elena; Romanov, Sergey

2013-04-01

Efficiency of landscape-geochemical approach was proved to be helpful in spatial and temporal evaluation of the Chernobyl radionuclide distribution in the environment. The peculiarity of such approach is in hierarchical consideration of factors responsible for radionuclide redistribution and behavior in a system of inter-incorporated landscape-geochemical structures of the local and regional scales with due regard to the density of the initial fallout and patterns of radionuclide migration in soil-water-plant systems. The approach has been applied in the studies of distribution of Cs-137, Sr-90 and some other radionuclides in soils and vegetation cover and in evaluation of contribution of the stable iodine supply in soils to spatial variation of risk of thyroid cancer in areas subjected to radioiodine contamination after the Chernobyl accident. The main feature of the proposed approach is simultaneous consideration of two types of spatial heterogeneities: firstly, the inhomogeneity of external radiation exposure due to a complex structure of the contamination field, and, secondly, the landscape geochemical heterogeneity of the affected area, so that the resultant effect of radionuclide impact could significantly vary in space. The main idea of risk assessment in this respect was to reproduce as accurately as possible the result of interference of two surfaces in the form of risk map. The approach, although it demands to overcome a number of methodological difficulties, allows to solve the problems associated with spatially adequate protection of the affected population and optimization of the use of contaminated areas. In general it can serve the basis for development of the idea of the two-level structure of modern radiobiogeochemical provinces formed by superposition of the natural geochemical structures and the fields of technogenic contamination accompanied by the corresponding peculiar and integral biological reactions.

An Experimental Study of Diffusivity of Technetium-99 in Hanford Vadose Zone Sediments

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V.; Bovaird, Chase C.; Wellman, Dawn M.

2012-11-01

One of the methods being considered at the Hanford site in Washington for safely disposing of low-level radioactive wastes (LLW) is to encase the waste in concrete and entomb the packages in the Hanford vadose zone sediments. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages with concrete. Any failure of the concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion andmore » move into the surrounding subsurface sediments. It is therefore necessary to conduct an assessment of the performance of the concrete encasement structure and the surrounding soil’s ability to retard radionuclide migration. The retardation factors for radionuclides contained in the waste packages can be determined from measurements of diffusion coefficients for these contaminants through concrete and fill material. Because of their anionic nature in aqueous solutions, the radionuclides, 99Tc and 129I were identified as long-term dose contributors in LLW. The leachability and/or diffusion of these radionuclide species must be measured in order to assess the long-term performance of waste grouts when contacted with vadose-zone porewater or groundwater. To measure the diffusivity, a set of experiments were conducted using 99Tc-spiked concrete (with 0 and 4% metallic iron additions) in contact with unsaturated soil half-cells that reflected the typical moisture contents of Hanford vadose zone sediments. The 99Tc diffusion profiles in the soil half cells were measured after a time lapse of ~1.9 yr. Using the concentration profiles, the 99Tc diffusivity coefficients were calculated based on Fick’s Second Law.« less

Recent developments in assessment of long-term radionuclide behavior in the geosphere-biosphere subsystem.

PubMed

Smith, G M; Smith, K L; Kowe, R; Pérez-Sánchez, D; Thorne, M; Thiry, Y; Read, D; Molinero, J

2014-05-01

Decisions on permitting, controlling and monitoring releases of radioactivity into the environment rely on a great variety of factors. Important among these is the prospective assessment of radionuclide behavior in the environment, including migration and accumulation among and within specific environmental media, and the resulting environmental and human health impacts. Models and techniques to undertake such assessments have been developed over several decades based on knowledge of the ecosystems involved, as well as monitoring of previous radionuclide releases to the environment, laboratory experiments and other related research. This paper presents developments in the assessment of radiation doses and related research for some of the key radionuclides identified as of potential significance in the context of releases to the biosphere from disposal facilities for solid radioactive waste. Since releases to the biosphere from disposal facilities involve transfers from the geosphere to the biosphere, an important aspect is the combined effects of surface hydrology, near-surface hydrogeology and chemical gradients on speciation and radionuclide mobility in the zone in which the geosphere and biosphere overlap (herein described as the geosphere-biosphere subsystem). In turn, these aspects of the environment can be modified as a result of environmental change over the thousands of years that have to be considered in radioactive waste disposal safety assessments. Building on the experience from improved understanding of the behavior of the key radionuclides, this paper proceeds to describe development of a generic methodology for representing the processes and environmental changes that are characteristic of the interface between the geosphere and the biosphere. The information that is provided and the methodology that is described are based on international collaborative work implemented through the BIOPROTA forum, www.bioprota.org. Copyright © 2013 Elsevier Ltd. All rights reserved.

Evaluation of Groundwater Pathways and Travel Times From the Nevada Test Site to the Potential Yucca Mountain Repository

NASA Astrophysics Data System (ADS)

Pohlmann, K. F.; Zhu, J.; Ye, M.; Carroll, R. W.; Chapman, J. B.; Russell, C. E.; Shafer, D. S.

2006-12-01

Yucca Mountain (YM), Nevada has been recommended as a deep geological repository for the disposal of spent fuel and high-level radioactive waste. If YM is licensed as a repository by the Nuclear Regulatory Commission, it will be important to identify the potential for radionuclides to migrate from underground nuclear testing areas located on the Nevada Test Site (NTS) to the hydraulically downgradient repository area to ensure that monitoring does not incorrectly attribute repository failure to radionuclides originating from other sources. In this study, we use the Death Valley Regional Flow System (DVRFS) model developed by the U.S. Geological Survey to investigate potential groundwater migration pathways and associated travel times from the NTS to the proposed YM repository area. Using results from the calibrated DVRFS model and the particle tracking post-processing package MODPATH we modeled three-dimensional groundwater advective pathways in the NTS and YM region. Our study focuses on evaluating the potential for groundwater pathways between the NTS and YM withdrawal area and whether travel times for advective flow along these pathways coincide with the prospective monitoring time frame at the proposed repository. We include uncertainty in effective porosity as this is a critical variable in the determination of time for radionuclides to travel from the NTS region to the YM withdrawal area. Uncertainty in porosity is quantified through evaluation of existing site data and expert judgment and is incorporated in the model through Monte Carlo simulation. Since porosity information is limited for this region, the uncertainty is quite large and this is reflected in the results as a large range in simulated groundwater travel times.

Modelling of Tc migration in an un-oxidized fractured drill core from Äspö, Sweden

NASA Astrophysics Data System (ADS)

Huber, F. M.; Totskiy, Y.; Montoya Garcia, V.; Enzmann, F.; Trumm, M.; Wenka, A.; Geckeis, H.; Schaefer, T.

2015-12-01

The radionuclide retention of redox sensitive radionuclides (e.g. Pu, Np, U, Tc) in crystalline host rock greatly depends on the rock matrix and the rock redox capacity. Preservation of drill cores concerning oxidation is therefore of paramount importance to reliably predict the near-natural radionuclide retention properties. Here, experimental results of HTO and Tc laboratory migration experiments in a naturally single fractured Äspö un-oxidized drill core are modelled using two different 2D models. Both models employ geometrical information obtained by μ-computed tomography (μCT) scanning of the drill core. The models differ in geometrical complexity meaning the first model (PPM-MD) consists of a simple parallel plate with a porous matrix adjacent to the fracture whereas the second model (MPM) uses the mid-plane of the 3D fracture only (no porous matrix). Simulation results show that for higher flow rates (Peclet number > 1), the MPM satisfactorily describes the HTO breakthrough curves (BTC) whereas the PPM-MD model nicely reproduces the HTO BTC for small Pe numbers (<1). These findings clearly highlight the influence of fracture geometry/flow field complexity on solute transport for Pe numbers > 1 and the dominating effect of matrix diffusion for Peclet numbers < 1. Retention of Tc is modelled using a simple Kd-approach in case of the PPM-MD and including 1st order sorptive reduction/desorption kinetics in case of the MPM. Batch determined sorptive reduction/desorption kinetic rates and Kd values for Tc on non-oxidized Äspö diorite are used in the model and compared to best fit values. By this approach, the transferability of kinetic data concerning sorptive reduction determined in static batch experiments to dynamic transport experiments is examined.

Colloid-Facilitated Radionuclide Transport: Current State of Knowledge from a Nuclear Waste Repository Risk Assessment Perspective

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reimus, Paul William; Zavarin, Mavrik; Wang, Yifeng

2017-01-25

This report provides an overview of the current state of knowledge of colloid-facilitated radionuclide transport from a nuclear waste repository risk assessment perspective. It draws on work that has been conducted over the past 3 decades, although there is considerable emphasis given to work that has been performed over the past 3-5 years as part of the DOE Used Fuel Disposition Campaign. The timing of this report coincides with the completion of a 3-year DOE membership in the Colloids Formation and Migration (CFM) partnership, an international collaboration of scientists studying colloid-facilitated transport of radionuclides at both the laboratory and field-scalesmore » in a fractured crystalline granodiorite at the Grimsel Test Site in Switzerland. This Underground Research Laboratory has hosted the most extensive and carefully-controlled set of colloid-facilitated solute transport experiments that have ever been conducted in an in-situ setting, and a summary of the results to date from these efforts, as they relate to transport over long time and distance scales, is provided in Chapter 3 of this report.« less

THE EFFECT OF IONIZING RADIATION ON U6+ -PHASES

DOE Office of Scientific and Technical Information (OSTI.GOV)

S. Utsunomiya; R.C. Ewing

2005-07-07

U{sup 6+}-minerals commonly form during the alteration of uraninite and spent nuclear fuel under oxidizing conditions. By the incorporation of actinides and fissiogenic elements into their structures, U{sup 6+}-minerals may be important in retarding the migration of radionuclides released during corrosion of spent nuclear fuel. Thus, the stability and the structural transformation of the U{sup 6+}-minerals in radiation fields are of great interest.

Increased Concentrations of Short-Lived Decay-Series Radionuclides in Groundwaters Underneath the Nopal I Uranium Deposit at Pena Blanca, Mexico

NASA Astrophysics Data System (ADS)

Luo, S.; Ku, T.; Todd, V.; Murrell, M. T.; Dinsmoor, J. C.

2007-05-01

The Nopal I uranium ore deposit at Pena Blanca, Mexico, located at > 200 meters above the groundwater table, provides an ideal natural analog for quantifying the effectiveness of geological barrier for isolation of radioactive waste nuclides from reaching the human environments through ground water transport. To fulfill such natural analog studies, three wells (PB1, PB2, and PB3 respectively) were drilled at the site from the land surface down to the saturated groundwater zone and ground waters were collected from each of these wells through large- volume sampling/in-situ Mn-filter filtration for analyses of short-lived uranium/thorium-series radionuclides. Our measurements from PB1 show that the groundwater standing in the hole has much lower 222Rn activity than the freshly pumped groundwater. From this change in 222Rn activity, we estimate the residence time of groundwater in PB1 to be about 20 days. Our measurements also show that the activities of short-lived radioisotopes of Th (234Th), Ra (228Ra, 224Ra, 223Ra), Rn (222Rn), Pb (210Pb), and Po (210Po) in PB1, PB2, and PB3 are all significantly higher than those from the other wells near the Nopal I site. These high activities provide evidence for the enrichment of long-lived U and Ra isotopes in the groundwater as well as in the associated adsorbed phases on the fractured aquifer rocks underneath the ore deposit. Such enrichment suggests a rapid dissolution of U and Ra isotopes from the uranium ore deposit in the vadose zone and the subsequent migration to the groundwater underneath. A reactive transport model can be established to characterize the in-situ transport of radionuclides at the site. The observed change of 222Rn activity at PB1 also suggests that the measured high radioactivityies in ground waters from the site isare not an artifact of drilling operations. However, further studies are needed to assess if or to what extent the radionuclide migration is affected by the previous mining activities at the site.

The characterization and risk assessment of the `Red Forest` radioactive waste burial site at Chernobyl Nuclear Power Plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bungai, D.A.; Skalskij, A.S.; Dzhepo, S.P.

The `Red Forest` radioactive waste burials created during emergency clean-up activities at Chernobyl Nuclear Power Plant represent a serious source of radioactive contamination of the local ground water system with 9OSr concentration in ground water exceeding the drinking water standard by 3-4 orders of magnitude. In this paper we present results of our hydrogeological and radiological `Red Forest` site characterization studies, which allow us to estimate 9OSr subsurface migration parameters. We use then these parameters to assess long terrain radionuclide transport to groundwater and surface water, and to analyze associated health risks. Our analyses indicate that 9OSr transport via groundmore » water pathway from `Red Forest` burials to the adjacent Pripyat River is relatively insignificant due to slow release of 9OSr from the waste burials (less than 1% of inventory per year) and due to long enough ground water residence time in the subsurface, which allows substantial decay of the radioactive contaminant. Tins result and our previous analyses indicate, that though conditions of radioactive waste storage in burials do not satisfy Ukrainian regulation on radiation protection, health risks caused by radionuclide migration to ground water from `Red Forest` burials do not justify application of expensive countermeasures.« less

Nuclear Waste Package Mockups: A Study of In-situ Redox State

NASA Astrophysics Data System (ADS)

Helean, K.; Anderson, B.; Brady, P. V.

2006-05-01

The Yucca Mountain Repository (YMR), located in southern Nevada, is to be the first facility in the U.S. for the permanent disposal of high-level radioactive waste and spent nuclear fuels. Total system performance assessment(TSPA) has indicated that among the major radionuclides contributing to dose are Np, Tc, and I. These three radionuclides are mobile in most geochemical settings, and therefore sequestering them within the repository horizon is a priority for the Yucca Mountain Project (YMP). Corroding steel may offset radionuclide transport processes within the proposed waste packages at YMR by retaining radionuclides, creating locally reducing conditions, and reducing porosity. Ferrous iron has been shown to reduce UO22+ to UO2s, and some ferrous iron-bearing ion-exchange materials have been shown to adsorb radionuclides and heavy metals. Locally reducing conditions may lead to the reduction and subsequent immobilization of problematic dissolved species such as TcO4-, NpO2+, and UO22+ and can also inhibit corrosion of spent nuclear fuel. Water occluded during corrosion produces bulky corrosion products, and consequently less porosity is available for water and radionuclide transport. The focus of this study is on the nature of Yucca Mountain waste package corrosion products and their effects on local redox conditions, radionuclide transport, and porosity. In order to measure in-situ redox, six small-scale (1:40) waste package mockups were constructed using A516 and 316 stainless steel, the same materials as the proposed Yucca Mountain waste packages. The mockups are periodically injected with a simulated groundwater and the accumulated effluent and corrosion products are evaluated for their Fe(II)/Fe(III) content and mineralogy. Oxygen fugacities are then calculated and, thus, in-situ redox conditions are determined. Early results indicate that corrosion products are largely amorphous Fe-oxyhydroxides, goethite and magnetite. That information together with the measured Fe(II)/Fe(III) ratios in the mockup effluent constrain the oxygen fugacity to approximately 10-38 atm, many orders of magnitude below ambient. These results and their impact on radionuclide migration from YMR will be discussed.

Selected, annotated bibliography of studies relevant to the isolation of nuclear wastes. [705 references

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hyder, L.K.; Fore, C.S.; Vaughan, N.D.

This annotated bibliography of 705 references represents the first in a series to be published by the Ecological Sciences Information Center containing scientific, technical, economic, and regulatory information relevant to nuclear waste isolation. Most references discuss deep geologic disposal, with fewer studies of deep seabed disposal; space disposal is also included. The publication covers both domestic and foreign literature for the period 1954 to 1980. Major chapters selected are Chemical and Physical Aspects; Container Design and Performance; Disposal Site; Envirnmental Transport; General Studies and Reviews; Geology, Hydrology and Site Resources; Regulatory and Economic Aspects; Repository Design and Engineering; Transportation Technology;more » Waste Production; and Waste Treatment. Specialized data fields have been incorporated to improve the ease and accuracy of locating pertinent references. Specific radionuclides for which data are presented are listed in the Measured Radionuclides field, and specific parameters which affect the migration of these radionuclides are presented in the Measured Parameters field. The references within each chapter are arranged alphabetically by leading author, corporate affiliation, or title of the document. When the author is not given, the corporate affiliation appears first. If these two levels of authorship are not given, the title of the document is used as the identifying level. Indexes are provided for author(s), keywords, subject category, title, geographic location, measured parameters, measured radionuclides, and publication description.« less

Radionuclide migration: laboratory experiments with isolated fractures

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rundberg, R.S.; Thompson, J.L.; Maestas, S.

Laboratory experiments examining flow and element migration in rocks containing isolated fractures have been initiated at the Los Alamos National Laboratory. Techniques are being developed to establish simple fracture flow systems which are appropriate to models using analytical solutions to the matrix diffusion-flow equations, such as those of I. Neretnieks [I. Neretnieks, Diffusion in the Rock Matrix: An Important Factor in Radionuclide Retardation? J. Geophys. Res. 85, 4379 (1980).] These experiments are intended to be intermediate steps toward larger scale field experiments where it may become more difficult to establish and control the parameters important to nuclide migration in fracturedmore » media. Laboratory experiments have been run on fractures ranging in size from 1 to 20 cm in length. The hydraulic flow in these fractures was studied to provide the effective apertures. The flows established in these fracture systems are similar to those in the granite fracture flow experiments of Witherspoon et al. [P.A. Witherspoon, J.S.Y. Wang, K. Iwai, and J.E. Gale, Validity of Cubic Law for Fluid Flow in a Deformable Rock Fracture, Lawrence Berkeley Laboratory report LBL-9557 (October 1979).] Traced solutions containing {sup 85}Sr and {sup 137}Cs were flowed through fractures in Climax Stock granite and welded tuff (Bullfrog and Tram members, Yucca Mountain, Nevada Test Site). The results of the elutions through granite agree with the matrix diffusion calculations based on independent measurements of K/sub d/. The results of the elutions through tuff, however, agree only if the K/sub d/ values used in the calculations are lower than the K/sub d/ values measured using a batch technique. This trend has been previously observed in chromatographic column experiments with tuff. 5 figures, 3 tables.« less

Natural attenuation of Fukushima-derived radiocesium in soils due to its vertical and lateral migration.

PubMed

Konoplev, A; Golosov, V; Wakiyama, Y; Takase, T; Yoschenko, V; Yoshihara, T; Parenyuk, O; Cresswell, A; Ivanov, M; Carradine, M; Nanba, K; Onda, Y

2018-06-01

Processes of vertical and lateral migration lead to gradual reduction in contamination of catchment soil, particularly its top layer. The reduction can be considered as natural attenuation. This, in turn, results in a gradual decrease of radiocesium activity concentrations in the surface runoff and river water, in both dissolved and particulate forms. The purpose of this research is to study the dynamics of Fukushima-derived radiocesium in undisturbed soils and floodplain deposits exposed to erosion and sedimentation during floods. Combined observations of radiocesium vertical distribution in soil and sediment deposition on artificial lawn-grass mats on the Niida River floodplain allowed us to estimate both annual mean sediment accumulation rates and maximum sedimentation rates corresponding to an extreme flood event during Tropical Storm Etau, 6-11 September 2015. Dose rates were reduced considerably for floodplain sections with high sedimentation because the top soil layer with high radionuclide contamination was eroded and/or buried under cleaner fresh sediments produced mostly due to bank erosion and sediments movements. Rate constants of natural attenuation on the sites of the Takase River and floodplain of Niida River was found to be in range 0.2-0.4 year -1 . For the site in the lower reach of the Niida River, collimated shield dose readings from soil surfaces slightly increased during the period of observation from February to July 2016. Generally, due to more precipitation, steeper slopes, higher temperatures and increased biological activities in soils, self-purification of radioactive contamination in Fukushima associated with vertical and lateral radionuclide migration is faster than in Chernobyl. In many cases, monitored natural attenuation along with appropriate restrictions seems to be optimal option for water remediation in Fukushima contaminated areas. Copyright © 2017. Published by Elsevier Ltd.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rockhold, Mark L.; White, Mark D.; Freeman, Eugene J.

This letter report documents initial numerical analyses conducted by PNNL to provide support for a feasibility study on decommissioning of the canyon buildings at Hanford. The 221-U facility is the first of the major canyon buildings to be decommissioned. The specific objective of this modeling effort was to provide estimates of potential rates of migration of residual contaminants out of the 221-U facility during the first 40 years after decommissioning. If minimal contaminant migration is predicted to occur from the facility during this time period, then the structure may be deemed to provide a level of groundwater protection that ismore » essentially equivalent to the liner and leachate collection systems that are required at conventional landfills. The STOMP code was used to simulate transport of selected radionuclides out of a canyon building, representative of the 221-U facility after decommissioning, for a period of 40 years. Simulation results indicate that none of the selected radionuclides that were modeled migrated beyond the concrete structure of the facility during the 40-year period of interest. Jacques (2001) identified other potential contaminants in the 221-U facility that were not modeled, however, including kerosene, phenol, and various metals. Modeling of these contaminants was beyond the scope of this preliminary effort due to increased complexity. Simulation results indicate that contaminant release from the canyon buildings will be diffusion controlled at early times. Advection is expected to become much more important at later times, after contaminants have diffused out of the facility and into the surrounding soil environment. After contaminants have diffused out of the facility, surface infiltration covers will become very important for mitigating further transport of contaminants in the underlying vadose zone and groundwater.« less

Defining modeling parameters for juniper trees assuming pleistocene-like conditions at the NTS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tarbox, S.R.; Cochran, J.R.

1994-12-31

This paper addresses part of Sandia National Laboratories` (SNL) efforts to assess the long-term performance of the Greater Confinement Disposal (GCD) facility located on the Nevada Test Site (NTS). Of issue is whether the GCD site complies with 40 CFR 191 standards set for transuranic (TRU) waste burial. SNL has developed a radionuclide transport model which can be used to assess TRU radionuclide movement away from the GCD facility. An earlier iteration of the model found that radionuclide uptake and release by plants is an important aspect of the system to consider. Currently, the shallow-rooted plants at the NTS domore » not pose a threat to the integrity of the GCD facility. However, the threat increases substantially it deeper-rooted woodland species migrate to the GCD facility, given a shift to a wetter climate. The model parameters discussed here will be included in the next model iteration which assumes a climate shift will provide for the growth of juniper trees at the GCD facility. Model parameters were developed using published data and wherever possible, data were taken from juniper and pinon-juniper studies that mirrored as many aspects of the GCD facility as possible.« less

Radionuclide Transport in Fracture-Granite Interface Zones

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hu, Q; Mori, A

In situ radionuclide migration experiments, followed by excavation and sample characterization, were conducted in a water-conducting shear zone at the Grimsel Test Site (GTS) in Switzerland to study diffusion paths of radionuclides in fractured granite. In this work, we employed a micro-scale mapping technique that interfaces laser ablation sampling with inductively coupled plasma-mass spectrometry (LA/ICP-MS) to measure the fine-scale (micron-range) distribution of actinides ({sup 234}U, {sup 235}U, and {sup 237}Np) in the fracture-granite interface zones. Long-lived {sup 234}U, {sup 235}U, and {sup 237}Np were detected in flow channels, as well as in the adjacent rock matrix, using the sensitive, feature-basedmore » mapping of the LA/ICP-MS technique. The injected sorbing actinides are mainly located within the advective flowing fractures and the immediately adjacent regions. The water-conducting fracture studied in this work is bounded on one side by mylonite and the other by granitic matrix regions. These actinides did not penetrate into the mylonite side as much as the relatively higher-porosity granite matrix, most likely due to the low porosity, hydraulic conductivity, and diffusivity of the fracture wall (a thickness of about 0.4 mm separates the mylonite region from the fracture) and the mylonite region itself. Overall, the maximum penetration depth detected with this technique for the more diffusive {sup 237}Np over the field experimental time scale of about 60 days was about 10 mm in the granitic matrix, illustrating the importance of matrix diffusion in retarding radionuclide transport from the advective fractures. Laboratory tests and numerical modeling of radionuclide diffusion into granitic matrix was conducted to complement and help interpret the field results. Measured apparent diffusivity of multiple tracers in granite provided consistent predictions for radionuclide transport in the fractured granitic rock.« less

Transport of Gas Phase Radionuclides in a Fractured, Low-Permeability Reservoir

NASA Astrophysics Data System (ADS)

Cooper, C. A.; Chapman, J.

2001-12-01

The U.S. Atomic Energy Commission (predecessor to the Department of Energy, DOE) oversaw a joint program between industry and government in the 1960s and 1970s to develop technology to enhance production from low-permeability gas reservoirs using nuclear stimulation rather than conventional means (e.g., hydraulic and/or acid fracturing). Project Rio Blanco, located in the Piceance Basin, Colorado, was the third experiment under the program. Three 30-kiloton nuclear explosives were placed in a 2134 m deep well at 1780, 1899, and 2039 m below the land surface and detonated in May 1973. Although the reservoir was extensively fractured, complications such as radionuclide contamination of the gas prevented production and subsequent development of the technology. Two-dimensional numerical simulations were conducted to identify the main transport processes that have occurred and are currently occurring in relation to the detonations, and to estimate the extent of contamination in the reservoir. Minor modifications were made to TOUGH2, the multiphase, multicomponent reservoir simulator developed at Lawrence Berkeley National Laboratories. The simulator allows the explicit incorporation of fractures, as well as heat transport, phase change, and first order radionuclide decay. For a fractured two-phase (liquid and gas) reservoir, the largest velocities are of gases through the fractures. In the gas phase, tritium and one isotope of krypton are the principle radionuclides of concern. However, in addition to existing as a fast pathway, fractures also permit matrix diffusion as a retardation mechanism. Another retardation mechanism is radionuclide decay. Simulations show that incorporation of fractures can significantly alter transport rates, and that radionuclides in the gas phase can preferentially migrate upward due to the downward gravity drainage of liquid water in the pores. This project was funded by the National Nuclear Security Administration, Nevada Operations Office, under DOE Contract no. DE-AC08-00NV13609.

Mass spectrometry of long-lived radionuclides

NASA Astrophysics Data System (ADS)

Becker, Johanna Sabine

2003-10-01

The capability of determining element concentrations at the trace and ultratrace level and isotope ratios is a main feature of inorganic mass spectrometry. The precise and accurate determination of isotope ratios of long-lived natural and artificial radionuclides is required, e.g. for their environmental monitoring and health control, for studying radionuclide migration, for age dating, for determining isotope ratios of radiogenic elements in the nuclear industry, for quality assurance and determination of the burn-up of fuel material in a nuclear power plant, for reprocessing plants, nuclear material accounting and radioactive waste control. Inorganic mass spectrometry, especially inductively coupled plasma mass spectrometry (ICP-MS) as the most important inorganic mass spectrometric technique today, possesses excellent sensitivity, precision and good accuracy for isotope ratio measurements and practically no restriction with respect to the ionization potential of the element investigated—therefore, thermal ionization mass spectrometry (TIMS), which has been used as the dominant analytical technique for precise isotope ratio measurements of long-lived radionuclides for many decades, is being replaced increasingly by ICP-MS. In the last few years instrumental progress in improving figures of merit for the determination of isotope ratio measurements of long-lived radionuclides in ICP-MS has been achieved by the application of a multiple ion collector device (MC-ICP-MS) and the introduction of the collision cell interface in order to dissociate disturbing argon-based molecular ions, to reduce the kinetic energy of ions and neutralize the disturbing noble gas ions (e.g. of 129Xe + for the determination of 129I). The review describes the state of the art and the progress of different inorganic mass spectrometric techniques such as ICP-MS, laser ablation ICP-MS vs. TIMS, glow discharge mass spectrometry, secondary ion mass spectrometry, resonance ionization mass spectrometry and accelerator mass spectrometry for the determination of long-lived radionuclides in quite different materials.

Isotopic ratio and vertical distribution of radionuclides in soil affected by the accident of Fukushima Dai-ichi nuclear power plants.

PubMed

Fujiwara, Takeshi; Saito, Takumi; Muroya, Yusa; Sawahata, Hiroyuki; Yamashita, Yuji; Nagasaki, Shinya; Okamoto, Koji; Takahashi, Hiroyuki; Uesaka, Mitsuru; Katsumura, Yosuke; Tanaka, Satoru

2012-11-01

The results of γ analyses of soil samples obtained from 50 locations in Fukushima prefecture on April 20, 2011, revealed the presence of a spectrum of radionuclides resulted from the accident of the Fukushima Dai-ichi nuclear power plant (FDNPP). The sum γ radioactivity concentration ranged in more than 3 orders of magnitude, depending on the sampling locations. The contamination of soils in the northwest of the FDNPP was considerable. The (131)I/(137)Cs activity ratios of the soil samples plotted as a function of the distance from the F1 NPPs exhibited three distinctive patterns. Such patterns would reflect not only the different deposition behaviors of these radionuclides, but also on the conditions of associated release events such as temperature and compositions and physicochemical forms of released radionuclides. The (136)Cs/(137)Cs activity ratio, on the other hand, was considered to only reflect the difference in isotopic compositions of source materials. Two locations close to the NPP in the northwest direction were found to be depleted in short-lived (136)Cs. This likely suggested the presence of distinct sources with different (136)Cs/(137)Cs isotopic ratios, although their details were unknown at present. Vertical γ activity profiles of (131)I and (137)Cs were also investigated, using 20-30 cm soil cores in several locations. About 70% or more of the radionuclides were present in the uppermost 2-cm regions. It was found that the profiles of (131)I/(137)Cs activity ratios showed maxima in the 2-4 cm regions, suggesting slightly larger migration of the former nuclide. Copyright © 2012 Elsevier Ltd. All rights reserved.

Modeling Sr-90 Retardation by Fractured Rocks Based on the Results of In Situ and Laboratory Research

NASA Astrophysics Data System (ADS)

Samsanova, L.; Kotchergina, N. V.; Glinsky, M.; Zinin, A.; Ivanov, I.

2001-12-01

Industrial solutions from the surface storage of liquid radioactive wastes in Lake Karachay have been migrating in groundwaters for 50 years. Interaction of industrial solutions with fractured water-bearing rocks results in the formation of a plume body of contaminated rocks due to a partial retardation of the migrating radionuclides. In conducting research of the fractured rocks core samples from the wells located within the contaminated ground water plume, we have obtained empirical estimations of the retardation parameter (Sr-90 interphase distribution factor, Kd). To interpret the experimental data on Sr-90 Kd, a method of modeling of strontium-90 retardation by fractured rocks has been developed. The process of transient filtration for a flow fragment from Lake Karachay was reconstructed. Epignose modeling of the industrial solution's main flow migrating from Lake Karachay in south direction was performed. By solving the inverse tasks Kd of strontium-90 was estimated for the fractured rocks.

Radioactive characterization of phosphogypsum from Imbituba, Brazil.

PubMed

Borges, Renata Coura; Ribeiro, Fernando Carlos Araujo; Lauria, Dejanira da Costa; Bernedo, Alfredo Victor Bellido

2013-12-01

This research aims to characterize the content of natural occurring radionuclides in phosphogypsum stacks at Imbituba, Santa Catarina state, Brazil. (226)Ra, (228)Ra, (40)K, (238)U and (232)Th were determined in PG, soils and sediment samples by gamma spectrometry using the hyper pure germanium detector and neutron activation. The migration of radionuclides in the phosphogypsum profile did not show the same behavior for all sampling sites. The mean activity concentration of (226)Ra was 95 Bq kg(-1), which is far below the limit recommended by the U.S. Environmental Agency (USEPA) for its application in agriculture (370 Bq kg(-1)) and the Brazilian Commission of Nuclear Energy Resolution 113 that established a reference level of 1000 Bq kg(-1) of (226)Ra or (228)Ra for the use of PG in agriculture as well as building materials. Copyright © 2013 Elsevier Ltd. All rights reserved.

Effects of Containment on Radionuclide Releases from Underground Nuclear Explosions

NASA Astrophysics Data System (ADS)

Carrigan, C. R.; Sun, Y.

2016-12-01

Confirming the occurrence of an underground nuclear explosion can require capturing short-lived noble gas radioisotopes produced by the explosion, sometimes referred to as the "smoking gun" for nuclear explosion detection. It is well known that the radioisotopic distribution resulting from the detonation evolves with time in the explosion cavity. In effect, the explosion cavity or chimney behaves as a chemical reactor. As long as the parent and daughter radionuclides remain in a closed and well-mixed cavity, parameters, such as radioxenon isotopic ratios, can be calculated analytically from a decay-chain network model. When gases from the cavity migrate into the containment regime, consideration of a "leaky reactor" model is more appropriate. We consider several implications of such a leaky reactor model relevant to interpretations of gas samples from the subsurface during an on-site inspection that could potentially be carried out under the Comprehensive Nuclear Test Ban Treaty. Additionally, we have attempted to validate our leaky reactor model against atmospheric observations of radioactive xenon isotopes detected by radionuclide monitoring stations in Japan and Russia following the February 2013 DPRK underground nuclear explosion (Carrigan et al., 2016). While both model uncertainty and observational error are significant, our model of isotopic evolution appears to be in broad agreement with radionuclide observations, and for the first time links atmospheric measurements of radioxenon isotopic ratios to estimates of seismic yield. Carrigan et al., Scientific Reports 6, Article number: 23032 (2016) doi:10.1038/srep23032

Low-level radioactive waste technology: a selected, annotated bibliography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fore, C.S.; Vaughan, N.D.; Hyder, L.K.

1980-10-01

This annotated bibliography of 447 references contains scientific, technical, economic, and regulatory information relevant to low-level radioactive waste technology. The bibliography focuses on environmental transport, disposal site, and waste treatment studies. The publication covers both domestic and foreign literature for the period 1952 to 1979. Major chapters selected are Chemical and Physical Aspects; Container Design and Performance; Disposal Site; Environmental Transport; General Studies and Reviews; Geology, Hydrology and Site Resources; Regulatory and Economic Aspects; Transportation Technology; Waste Production; and Waste Treatment. Specialized data fields have been incorporated into the data file to improve the ease and accuracy of locating pertinentmore » references. Specific radionuclides for which data are presented are listed in the Measured Radionuclides field, and specific parameters which affect the migration of these radionuclides are presented in the Measured Parameters field. In addition, each document referenced in this bibliography has been assigned a relevance number to facilitate sorting the documents according to their pertinence to low-level radioactive waste technology. The documents are rated 1, 2, 3, or 4, with 1 indicating direct applicability to low-level radioactive waste technology and 4 indicating that a considerable amount of interpretation is required for the information presented to be applied. The references within each chapter are arranged alphabetically by leading author, corporate affiliation, or title of the document. Indexes are provide for (1) author(s), (2) keywords, (3) subject category, (4) title, (5) geographic location, (6) measured parameters, (7) measured radionuclides, and (8) publication description.« less

Laboratory and field studies related to radionuclide migration at the Nevada Test Site October 1, 1998-September 30, 1999

DOE Office of Scientific and Technical Information (OSTI.GOV)

D. L. Finnegan; K. S. Kung; B. A. Martinez

In this report the author describes his research in FY 1999 at the Nevada Test Site regarding the movement of radionuclides in groundwater. This work is funded by the US Department of Energy/Nevada Operations Office through their Defense Programs and Environmental Restorations divisions. Significant accomplishments include upgrading a spectrometer used to characterize groundwater colloids, acquisition of a probe to allow in situ measurement of groundwater parameters, and purchase of pumps for use in small-diameter access tubing. He collected water samples from a number of nuclear test sites during the past year. Samples from the chimney horizon at the Camembert sitemore » show that only volatile radionuclides are present there, as expected. Groundwater from the cavity region at the Cheshire site shows evidence of fission product leaching or desorption from melt glass or rock surfaces. Colloids present in this water were found to be remarkably stable during storage for many years. The colloid content of groundwater at the Cambric site and at UE-5n was found to be low relative to that in groundwater on Pahute Mesa. This, coupled with the apparent lack of groundwater flow in the alluvial rock at the Cambric site, suggests that radionuclide movement underground in this area is relatively minimal. He continued the yearly monitoring of the thermally hot cavity fluids at the Almendro site. He concludes this report by listing documents reviewed and presentations and publications generated by the program.« less

Assessing Natural Radionuclide Migration in the Legacy Tailings of Uranium Production

NASA Astrophysics Data System (ADS)

Bondarenko, G.; Koliabina, I.; Marinich, O.

2011-12-01

The former Prydniprovsky Chemical Plant in Dniprodzerzhynsk, Ukraine, processed uranium ore from 1949 until 1991. Multiple tailing ponds containing solid residual waste products from the uranium leaching and processing of uranium were accumulated along the Dnieper River, including the largest, adjacent to the Dnieper Reservoir, containing over 12 million tons of tailings. Samples for this study were selected from a core recovered from the Dnieper tailing pit in 2009, and used to assess radionuclide migration from tailing ponds. Samples were selected from different depths of the tailing pit core, analyzed for total radionuclide concentrations [Marinich et al., 2009], and successively leached using distilled water, followed by 1N ammonium acetate solution, and finally by 1N HCl solution. Leaching times were ~24 h at 15.17 °C. 238U, 230Th and 226Ra leachate activities were measured by γ-spectrometry with a Ge(Li) detector. 210Pb activity was measured using a SEB-01 scintillation β-spectrometer. Errors depended on measuring method, radionuclide, activity and exposure time: 238U, 11.9%; 230Th, 10.9%; 226Ra, 9.3%; 210Pb ~30%. The average total 238U activity in the tailing profile was 4 Bq/g. The concentration of 238U in the water leachates increased with depth from 14.5% (7-7.5 m), to 43% (11-11.5 m). The concentration of 238U in the acid leachates behaved similarly, increasing from 5.5 % to 15.5% with depth. While the total 230Th activity in increased from 30 Bq/g (7-7.5 m) to 540 Bq/g (11-11.5 m), the 230Th concentration in ammonium acetate leachates decreased from ˜15% to ˜1%. The concentration of 226Ra in all leachates was <1%, indicating that, under conditions of the Dnieper tailing pit, 226Ra is essentially immobile. The concentration of 210Pb in the leachates was as high as 10%. In general, the magnitude of mobile activity from the Dnieper tailing pit core samples decreases in the order 238U>230Th≥210Pb> 226Ra. Secular radioactive equilibrium in the 238U - 230Th - 226Ra - 210Pb decay chain, typical for closed systems, has been disturbed during selective chemical uranium extraction from the parent ore. We calculated the migration of 210Pb, assuming constant 226Ra activity. The results of these calculations show that over 50 years, ~18% of the initial (unknown) 210Pb(0) activity was removed. If we assume removal of 226Ra decay products will continue at the current level, we expect the future annual activity loss of 210Pb to be about 0.36% per year, or 0.072 Bq/g. Assuming the examined core sample is representative of all 12 million tons of tails, the total annual activity loss is estimated to be ~1012 Bq/year. These results allow us to conclude that the loss of activity from the tailing pit by water migration is mainly associated with the 226Ra decay products: 222Rn, 210Pb, 210Po.
Activity ratios, Dnieper tailings

Colloid-facilitated radionuclide transport: a regulatory perspective

NASA Astrophysics Data System (ADS)

Dam, W. L.; Pickett, D. A.; Codell, R. B.; Nicholson, T. J.

2001-12-01

What hydrogeologic-geochemical-microbial conditions and processes affect migration of radionuclides sorbed onto microparticles or native colloid-sized radionuclide particles? The U.S. Nuclear Regulatory Commission (NRC) is responsible for protecting public health, safety, and the environment at numerous nuclear facilities including a potential high-level nuclear waste disposal site. To fulfill these obligations, NRC needs to understand the mechanisms controlling radionuclide release and transport and their importance to performance. The current focus of NRC staff reviews and technical interactions dealing with colloid-facilitated transport relates to the potential nuclear-waste repository at Yucca Mountain, Nevada. NRC staff performed bounding calculations to quantify radionuclide releases available for ground-water transport to potential receptors from a Yucca Mountain repository. Preliminary analyses suggest insignificant doses of plutonium and americium colloids could be derived from spent nuclear fuel. Using surface complexation models, NRC staff found that colloids can potentially lower actinide retardation factors by up to several orders of magnitude. Performance assessment calculations, in which colloidal transport of plutonium and americium was simulated by assuming no sorption or matrix diffusion, indicated no effect of colloids on human dose within the 10,000 year compliance period due largely to long waste-package lifetimes. NRC staff have identified information gaps and developed technical agreements with the U.S. Department of Energy (DOE) to ensure sufficient information will be presented in any potential future Yucca Mountain license application. DOE has agreed to identify which radionuclides could be transported via colloids, incorporate uncertainties in colloid formation, release and transport parameters, and conceptual models, and address the applicability of field data using synthetic microspheres as colloid analogs. NRC is currently investigating approaches to colloid modeling in order to help evaluate DOE's approach. One alternative approach uses DOE laboratory data to invoke kinetic controls on reversible radionuclide attachment to colloids. A kinetic approach in which desorption from colloids is slow may help assess whether DOE's instantaneous equilibrium approach for reversible attachment, as well as their application of irreversible attachment to only a small portion of the radionuclide inventory, are reasonable and conservative. An approach to examine microbial processes would also contribute to considerations of leaching of radionuclides and colloid formation. Reducing uncertainties in colloid transport processes should help in better understanding their importance to repository performance. This work is an independent product and does not necessarily reflect the views or regulatory position of the NRC. CNWRA participation was funded under contract No. NRC-02-97-009.

Transfer of radionuclides from high polluted bottom sediments to marine organisms through benthic food chain in post Fukushima period

NASA Astrophysics Data System (ADS)

Bezhenar, Roman; Jung, Kyung Tae; Maderich, Vladimir; Willemsen, Stefan; de With, Govert; Qiao, Fangli

2015-04-01

A catastrophic earthquake and tsunami occurred on March 11, 2011 and severely damaged the Fukushima Daiichi Nuclear Power Plant (FDNPP) that resulted in an uncontrolled release of radioactivity into air and ocean. Around 80% of the radioactivity released due to the FDNPP accident in March-April 2011 was either directly discharged into the ocean or deposited onto the ocean surface from the atmosphere. A large amount of long-lived radionuclides (mainly Cs-137) were released into the environment. The concentration of radionuclides in the ocean reached a maximum in mid-April of 2011, and then gradually decreased. From 2011 the concentration of Cs-137 in water essentially fell except the area around the FDNPP where leaks of contaminated water are continued. However, in the bottom sediment high concentrations of Cs-137 were found in the first months after the accident and slowly decreased with time. Therefore, it should be expected that a time delay is found of sediment-bound radionuclides in marine organisms. For the modeling of radionuclide transfer from highly polluted bottom sediments to marine organisms the dynamical food chain model BURN-POSEIDON (Heling et al, 2002; Maderich et al., 2014) was extended. In this model marine organisms are grouped into a limited number of classes based on their trophic level and type of species. These include: phytoplankton, zooplankton, fishes (two types: piscivorous and non-piscivorous), crustaceans, and molluscs for pelagic food chain and bottom sediment invertebrates, demersal fishes and bottom predators for benthic food chain and whole water column predators feeding by pelagial and benthic fishes. Bottom invertebrates consume organic parts of bottom sediments with adsorbed radionuclides which then migrate through the food chain. All organisms take radionuclides directly from water as well as via food. In fishes where radioactivity is not homogeneously distributed over all tissues of the organism, it is assumed that radionuclide accumulates in a specific tissue called target tissue. This tissue (bone, flesh, stomach, and organs) controls the overall elimination rate of the nuclide in the organism. The model prediction for the coastal area around the FDNPP agree well with observations. In addition the effects from the Chernobyl accident on the Baltic Sea are modelled and these results also are in good agreement with available data. These results demonstrate the importance of the benthic food chain in long-term transfer of radionuclides from high polluted bottom sediments to the marine organisms. The developed model can be applied for different regions of the World Ocean.

The influence of physico-chemical properties of soils on the bioavailability of 65Zn

NASA Astrophysics Data System (ADS)

Kochetkov, Ilia; Anisimov, Vyacheslav

2014-05-01

Stability of soils to the effects of man-made origin pollutants is determined by their buffer capaci-ty (the ability to inactivate pollutants in a soil - soil solution - plant system). Soils are character-ized by the same types of stability as the ecosystem as a whole. Increased migration activity of pollutants is a symptom of ecological trouble, due to the soil transformation in an unstable state. Thus, the problem of the stability of soil is one of the fundamental problems of modern science. The aim of the study was to estimate the buffering capacity of soil as a key factor of their ecological and geochemical stability with respect to a relatively long-lived radionuclides 65Zn (T1/2 = 224 days), representing the radiological hazard in the location of nuclear facilities. There was proposed a method for scoring the buffering capacity of soils as for 65Zn contamination. It's based on dependence between the main physico-chemical soil properties and accumulation of the radionuclide in the aboveground plant parts (barley kind of "Zazersky-85"). The role of the considered indicators of soil health in the accumulation of radiozinc by plants was defined. The essence of this technique was to assess the contribution of individual characteristics of the soil condition, which play the most important role in the regulation of mobility (and bioavailability) of radionuclides, using the method of stepwise multiple regression analysis. For this aim representative sampling was compiled (from 20 soil types and varieties belonging to different climatic zones of the European part of the Russian Federation), thus providing a wide range of variation of the studied physical and chemical parameters, and also vegetation model experiments using 65Zn were held. On the basis of the conducted statistical analysis was revealed that the dominant contribution to the variation of the effective trait (accumulation coefficient of 65Zn) make: CaCO3 content, mobile iron (Tamm extract) and pH. As a result the studied soils were ranked according to the degree of resistance to pollution by 65Zn (ability to restrict migration ability of radionuclide in soil - plant system). It turned out that inactivating ability of soddy-carbonaceous soils (rendzina) more than 8 times higher than the same indicator for soddy-podzolic soils; 5 - 7 times for gray forest soils and chernozems; 1.5 times for the southern chernozems.

Migration of 137Cs in the soil of sloping semi-natural ecosystems in Northern Greece.

PubMed

Arapis, G D; Karandinos, M G

2004-01-01

In the present study, the 137Cs concentration in the soil of sloping semi-natural ecosystems at four different regions of Western Macedonia in Greece was measured 10 years after the Chernobyl accident. These regions were highly polluted due to the deposition of radionuclides escaped during the accident. The concentrations of 137Cs measured were found to differ significantly among the four regions. The rates of both horizontal and vertical migration in the soil were also evaluated. The vertical migration velocity of 137Cs was found to range from 0.1 to 0.3 cm per year, in the most contaminated areas. Consequently, 10 years following the Chernobyl accident, the bulk of 137Cs deposited over the surface of the studied areas in Greece was found to be restricted in the upper 5 cm layer of soil. Regarding the horizontal migration, in most of the sampling sites, we did not detect any displacement or trend to movement of radiocaesium on the surface from the upper to the lower levels of the slopes. Instead, we recorded decreased concentrations of 137Cs with the decrease of altitude.

Radionuclide migration in clayrock host formations for deep geological disposal of radioactive waste: advances in process understanding and up-scaling methods resulting from the EC integrated project `Funmig

NASA Astrophysics Data System (ADS)

Altmann, S.; Tournassat, C.; Goutelard, F.; Parneix, J. C.; Gimmi, T.; Maes, N.

2009-04-01

One of the ‘pillars' supporting Safety Cases for deep geological disposal of radioactive waste in clayrock formations is the knowledge base regarding radionuclide (Rn) retention by sorption and diffusion-driven transport which is why the EC integrated project ‘Funmig' focused a major part of its effort on advancing understanding of these two macroscopic phenomena. This talk presents some of the main results of this four year effort (2005-2008). One of the keys to understanding diffusion-driven transport of anionic and cationic radionuclide species in clayrocks lies in a detailed understanding of the phenomena governing Rn total concentration and speciation (dissolved, adsorbed) in the different types of pore spaces present in highly-compacted masses of permanently charged clay minerals. Work carried out on a specifically synthesized montmorillonite (a model for the clay mineral fraction in clayrocks) led to development, and preliminary experimental validation, of a conceptually coherent set of theoretical models (molecular dynamics, electrostatic double layer, thermodynamic) describing dissolved ion and water solvent behavior in this material. This work, complemented by the existing state of the art, provides a sound theoretical basis for explaining such important phenomena as anion exclusion, cation exchange and the diffusion behavior of anions, weakly sorbing cations and water tracers. Concerning the behavior of strongly sorbing and/or redox-reactive radionuclides in clay systems, project research improved understanding of the nature of sorption reactions and sorbed species structure for key radioelements, or analogues (U, Se, Eu, Sm, Yb, Nd) on the basal surfaces and in the interlayers of synthetic or purified clay minerals. A probable mechanism for Se(IV) retention by reduction to Se° in Fe2+-containing clays was brought to light; this same process was also studied on the Callovo-Oxfordien clayrock targeted by the French radwaste management program. The migration of most radionuclides in clayrocks, in particular the actinides, is limited by their strong sorption on rock mineral surfaces. Much effort was devoted in Funmig to improving understanding of this process on the clayrocks being studied in the Swiss, Belgian and French radwaste management programs. Specific attention was focused on (i) elucidating the effect of dissolved organic matter on Am(III), Th(IV), Eu(III) sorption on clayrock surfaces and (ii) determining the link between Kd measured on dispersed rock systems and the Kd operant in intact rock volumes, i.e. during diffusion. Regarding the latter question, results indicate that Kd values for ‘dispersed' and ‘intact' materials are quite similar for certain elements (Na, Sr, Cs, Co). On the other hand, Kd values obtained by modeling results of diffusion experiments involving strongly sorbing elements as Cs, Co and Eu were always significantly smaller than those predicted based on sorption data measured in corresponding batch systems. This is an area where additional research is being planned. A major effort was devoted to improving understanding of the effects of small-scale (m to cm) clayrock structure and large-scale (dm to hm) mineralogical composition on radionuclide diffusion-retention. The program focusing on the small-scale produced a method for simulating the results of tracer diffusion in an intact rock based on the actual rock microstructure of the rock sample to be used in the diffusion experiment. This model was used to predict / inverse model the spatial distribution of highly sorbing tracers (Eu, Cu). This overall approach is also being used to understand how changes in mineralogical composition can affect the values of macroscopic diffusion parameters (De, tortuosity, anisiotropy). At a much larger scale, the results of (i) a geostatistical analysis of clayrock mineralogical variability and (ii) measurements of De and Kd dependence on mineralogy for Cs and Cl, were combined to create models of parameter variability at the formation scale. These models were used to evaluate the effects of formation scale heterogeneity on predictive modeling of radionuclide migration. Measurements and modeling of natural tracer profiles were also carried out in order to evaluate the diffusion characteristics at geological time and space scales.

Experimental system to displace radioisotopes from upper to deeper soil layers: chemical research

PubMed Central

Cazzola, Pietro; Cena, Agostino; Ghignone, Stefano; Abete, Maria C; Andruetto, Sergio

2004-01-01

Background Radioisotopes are introduced into the environment following nuclear power plant accidents or nuclear weapons tests. The immobility of these radioactive elements in uppermost soil layers represents a problem for human health, since they can easily be incorporated in the food chain. Preventing their assimilation by plants may be a first step towards the total recovery of contaminated areas. Methods The possibility of displacing radionuclides from the most superficial soil layers and their subsequent stabilisation at lower levels were investigated in laboratory trials. An experimental system reproducing the environmental conditions of contaminated areas was designed in plastic columns. A radiopolluted soil sample was treated with solutions containing ions normally used in fertilisation (NO3-, NH4+, PO4--- and K+). Results Contaminated soils treated with an acid solution of ions NO3-, PO4--- and K+, undergo a reduction of radioactivity up to 35%, after a series of washes which simulate one year's rainfall. The capacity of the deepest soil layers to immobilize the radionuclides percolated from the superficial layers was also confirmed. Conclusion The migration of radionuclides towards deeper soil layers, following chemical treatments, and their subsequent stabilization reduces bioavailability in the uppermost soil horizon, preventing at the same time their transfer into the water-bearing stratum. PMID:15132749

Environmental radioactivity assessment around old uranium mining sites near Mangualde (Viseu), Portugal

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carvalho, Fernando P.; Torres, Lubelia M.; Oliveira, Joao M.

2007-07-01

Uranium ore was extracted in the surroundings of Mangualde city, North of Portugal, in the mines of Cunha Baixa, Quinta do Bispo and Espinho until a few years ago. Mining waste, milling tailings and acid mine waters are the on site remains of this extractive activity. Environmental radioactivity measurements were performed in and around these sites in order to assess the dispersal of radionuclides from uranium mining waste and the spread of acidic waters resulting from the in situ uranium leaching with sulphuric acid. Results show migration of acid waters into groundwater around the Cunha Baixa mine. This groundwater ismore » tapped by irrigation wells in the agriculture area near the Cunha Baixa village. Water from wells displayed uranium ({sup 238}U) concentrations up to 19x10{sup 3} mBq L{sup -1} and sulphate ion concentrations up to 1070 mg L{sup -1}. These enhanced concentrations are positively correlated with low water pH, pointing to a common origin for radioactivity, dissolved sulphate, and acidity in underground mining works. Radionuclide concentrations were determined in horticulture and farm products from this area also and results suggest low soil to plant transfer of radionuclides and low food chain transfer of radionuclides to man. Analysis of aerosols in surface air showed re suspension of dust from mining and milling waste heaps. Therefore, it is recommended to maintain mine water treatment and to plan remediation of these mine sites in order to prevent waste dispersal in the environment. (authors)« less

Multiactinide Analysis with Accelerator Mass Spectrometry for Ultratrace Determination in Small Samples: Application to an in Situ Radionuclide Tracer Test within the Colloid Formation and Migration Experiment at the Grimsel Test Site (Switzerland).

PubMed

Quinto, Francesca; Blechschmidt, Ingo; Garcia Perez, Carmen; Geckeis, Horst; Geyer, Frank; Golser, Robin; Huber, Florian; Lagos, Markus; Lanyon, Bill; Plaschke, Markus; Steier, Peter; Schäfer, Thorsten

2017-07-05

The multiactinide analysis with accelerator mass spectrometry (AMS) was applied to samples collected from the run 13-05 of the Colloid Formation and Migration (CFM) experiment at the Grimsel Test Site (GTS). In this in situ radionuclide tracer test, the environmental behavior of 233 U, 237 Np, 242 Pu, and 243 Am was investigated in a water conductive shear zone under conditions relevant for a nuclear waste repository in crystalline rock. The concentration of the actinides in the GTS groundwater was determined with AMS over 6 orders of magnitude from ∼15 pg/g down to ∼25 ag/g. Levels above 10 fg/g were investigated with both sector field inductively coupled plasma mass spectrometry (SF-ICPMS) and AMS. Agreement within a relative uncertainty of 50% was found for 237 Np, 242 Pu, and 243 Am concentrations determined with the two analytical methods. With the extreme sensitivity of AMS, the long-term release and retention of the actinides was investigated over 8 months in the tailing of the breakthrough curve of run 13-05 as well as in samples collected up to 22 months after. Furthermore, the evidence of masses 241 and 244 u in the CFM samples most probably representing 241 Am and 244 Pu employed in a previous tracer test demonstrated the analytical capability of AMS for in situ studies lasting more than a decade.

Separation of Long-Lived Fission Products Tc-99 and I-129 from Synthetic Effluents by Crown Ethers

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paviet-Hartmann, P.; Hartmann, T.

2006-07-01

To minimize significantly the radio-toxic inventory of nuclear geological repositories to come as well as to reduce the potential of radionuclides migration and to minimize long-term exposure, the concept of partitioning and transmutation (P/T) of nuclear waste is currently discussed. Transmutation offers the possibility to convert radio-toxic radionuclides with long half-lives into radionuclides of shorter half-lives, less toxic isotopes, or even into stable isotopes. Besides the most prominent isotopes of neptunium, plutonium, americium, and curium, the long-lived fission products Tc-99 and I-129 (half-lives of 2.13 x 10{sup 5} years, and 1.57 x 10{sup 7} years, respectively) are promising candidates formore » transmutation in order to prevent their migration from a nuclear repository. Partitioning and transmutation of the most radio-toxic radionuclides will not only minimize the nuclear waste load but most importantly will significantly reduce the long-term radio-toxic hazard of nuclear waste repositories to come. Prior to the deployment of partitioning and transmutation, selective extraction techniques are required to separate the radionuclides of concern. Since the discovery of crown ethers by C. Pedersen, various applications of crown ethers have drawn much attention. Although liquid-liquid extraction of alkali and alkali earth metals by crown ethers has been extensively studied, little data is available on the extraction of Tc-99 and I-129 by crown ethers. The methods developed herein for the specific extraction of Tc-99 and I-129 provide recommendations in support of their selectively extraction from liquid radioactive waste streams, mainly ILW. We report data on the solvent extraction of Tc-99 and I-129 from synthetic effluents by six crown ethers of varying cavity dimensions and derivatization. To satisfy the needs of new extractant systems we are demonstrating that crown ether (CE) based systems have the potential to serve as selective extractants for the separation of these long lived radionuclides from high level nuclear waste (HLW), intermediate level nuclear waste (ILW), and low level nuclear waste (LLW) streams. The experimental results show that dibenzo-18-crown-6 (DB 18C6) is highly selective towards Tc-99, and dicyclohexano-18-crown-6 (DC18C6) is highly selective towards I-129. The nature of the diluent was examined and was shown to be the most influential variable in controlling the extraction coefficients of Tc-99 and I-129. Therefore the addition of polar diluent acetone to non-polar diluent toluene enhanced the distribution coefficient of Tc-99 (DTc) was by a factor of 30. For I-129, the best extraction yield was obtained after introducing tetrachloroethane. Through the process, by a single extraction step, 85 % to 95 % of Tc-99 was extracted from synthetic effluents, while 84 % to 88 % of I-129 was extracted from different acidic media. The extraction by crown ether is a fairly rapid process and the total preparation time of the chemical separation takes about 20 minutes for a batch of eight samples. (authors)« less

A biosphere modeling methodology for dose assessments of the potential Yucca Mountain deep geological high level radioactive waste repository.

PubMed

Watkins, B M; Smith, G M; Little, R H; Kessler, J

1999-04-01

Recent developments in performance standards for proposed high level radioactive waste disposal at Yucca Mountain suggest that health risk or dose rate limits will likely be part of future standards. Approaches to the development of biosphere modeling and dose assessments for Yucca Mountain have been relatively lacking in previous performance assessments due to the absence of such a requirement. This paper describes a practical methodology used to develop a biosphere model appropriate for calculating doses from use of well water by hypothetical individuals due to discharges of contaminated groundwater into a deep well. The biosphere model methodology, developed in parallel with the BIOMOVS II international study, allows a transparent recording of the decisions at each step, from the specification of the biosphere assessment context through to model development and analysis of results. A list of features, events, and processes relevant to Yucca Mountain was recorded and an interaction matrix developed to help identify relationships between them. Special consideration was given to critical/potential exposure group issues and approaches. The conceptual model of the biosphere system was then developed, based on the interaction matrix, to show how radionuclides migrate and accumulate in the biosphere media and result in potential exposure pathways. A mathematical dose assessment model was specified using the flexible AMBER software application, which allows users to construct their own compartment models. The starting point for the biosphere calculations was a unit flux of each radionuclide from the groundwater in the geosphere into the drinking water in the well. For each of the 26 radionuclides considered, the most significant exposure pathways for hypothetical individuals were identified. For 14 of the radionuclides, the primary exposure pathways were identified as consumption of various crops and animal products following assumed agricultural use of the contaminated water derived from the deep well. Inhalation of dust (11 radionuclides) and external irradiation (1 radionuclide) were also identified as significant exposure modes. Contribution to the total flux to dose conversion factor from the drinking water pathway for each radionuclide was also assessed and for most radionuclides was found to be less than 10% of the total flux to dose conversion factor summed across all pathways. Some of the uncertainties related to the results were considered. The biosphere modeling results have been applied within an EPRI Total Systems Performance Assessment of Yucca Mountain. Conclusions and recommendations for future performance assessments are provided.

Geology and hydrology of radioactive solid-waste burial grounds at the Hanford Reservation, Washington

USGS Publications Warehouse

LaSala, Albert Mario; Doty, Gene C.

1976-01-01

The geology and hydrology of radioactive solid waste burial grounds at the Hanford Reservation were investigated, using existing data, by the U.S. Geological Survey as part of the waste management plan of the Richland Operations Office of the Energy Research and Development Administration. The purpose of the investigation was to assist the operations office in characterizing the burial sites as to present environmental safety and as to their suitability for long-term storage (several thousand to tens of thousands of years) of radioactive sol id wastes. The burial ground sites fall into two classifications: (1) those on the low stream terraces adjacent to the Columbia River, mainly in the 100 Areas and 300 Area, and (2) those lying on the high terraces south of Gable Mountain in the 200 Areas. Evaluation of the suitability of the burial grounds for long-term storage was made almost entirely on hydrologic, geologic, and topographic criteria. Of greatest concern was the possibility that radionuclides might be leached from the buried wastes by infiltrating water and carried downward to the water table. The climate is semi-arid and the average annual precipitation is 6.4 inches at the Hanford Meteorological Station. However, the precipitation is seasonally distributed with about 50 percent occurring during the months of November, December, January, and February when evapotranspiration is negligible and conditions for infiltration are most favorable. None of the burial grounds are instrumented with monitoring devices that could be used to determine if radionuclides derived from them are reaching the water table. Burial grounds on the low stream terraces are mainly underlain by permeable materials and the water table lies at relatively shallow depths. Radionuclides conceivably could be leached from these burial grounds by percolating soil water, and radionuclides might reach the Columbia River in a relatively short time. These sites could also be inundated by erosion during a catastrophic flood. For these reasons, they are judged to be unsuited for long-term storage. Local conditions at several of these burial grounds are particularly unfavorable from the standpoint of safety. Depressions and swales at some burial grounds, such as numbers 4 and 5 in the 300 Area in which runoff can collect, enhance the possibility of water infiltrating through the buried wastes and transporting radionuclides to the water table. Also, during a high stage of the Columbia River, the water table conceivably could rise into burial grounds l and 2 of the 100 F Area. Most of the burial grounds on the low terraces contain either (1) reactor components and related equipment bearing activation products, principally cobalt-60, or (2) less hazardous radioactive materials such as uranium. The inventory of activation products in these burial grounds will decay to a safe level in a relatively short period of time (about 100 years), according to estimates made by C. D. Corbit, Douglas United Nuclear, Inc., 1969. The inventory of radionuclides is not considered by the ERDA staff to be complete, however. At these burial grounds containing activation products or less hazardous materials, investigations should be made of the radioactivity in soil and ground water beneath selected representative sites to verify that radionuclides are not migrating from the burial grounds. If migration is detected, field investigations should be made to determine the source or sources of the radionuclides and the desirability of removing the source wastes. Other burial grounds on the low terraces contain plutonium and fission products, which require long-term storage. Both the 300 WYE and the 300 North burial grounds are reported to contain plutonium in large quantities. Burial ground no. l in the 300 Area reportedly also contains plutonium. The inventory records of any other burial grounds on the low terraces suspected of containing plutonium should be reviewed to determine if pl

A new code for modelling the near field diffusion releases from the final disposal of nuclear waste

NASA Astrophysics Data System (ADS)

Vopálka, D.; Vokál, A.

2003-01-01

The canisters with spent nuclear fuel produced during the operation of WWER reactors at the Czech power plants are planned, like in other countries, to be disposed of in an underground repository. Canisters will be surrounded by compacted bentonite that will retard the migration of safety-relevant radionuclides into the host rock. A new code that enables the modelling of the critical radionuclides transport from the canister through the bentonite layer in the cylindrical geometry was developed. The code enables to solve the diffusion equation for various types of initial and boundary conditions by means of the finite difference method and to take into account the non-linear shape of the sorption isotherm. A comparison of the code reported here with code PAGODA, which is based on analytical solution of the transport equation, was made for the actinide chain 4N+3 that includes 239Pu. A simple parametric study of the releases of 239Pu, 129I, and 14C into geosphere is discussed.

[Microbiological Aspects of Radioactive Waste Storage].

PubMed

Safonov, A V; Gorbunova, O A; German, K E; Zakharova, E V; Tregubova, V E; Ershov, B G; Nazina, T N

2015-01-01

The article gives information about the microorganisms inhabiting in surface storages of solid radioactive waste and deep disposal sites of liquid radioactive waste. It was shown that intensification of microbial processes can lead to significant changes in the chemical composition and physical state of the radioactive waste. It was concluded that the biogeochemical processes can have both a positive effect on the safety of radioactive waste storages (immobilization of RW macrocomponents, a decreased migration ability of radionuclides) and a negative one (biogenic gas production in subterranean formations and destruction of cement matrix).

Radioactivity measurements on migrating birds (Turdus philomelos) captured in the Comunidad Valenciana (Spain).

PubMed

Navarro, E; Roldán, C; Cervera, J; Ferrero, J L

1998-01-19

The radionuclides 137Cs, 134Cs and 90Sr have been measured in edible tissues and bones of migratory birds (song-thrushes, Turdus philomelos) from central and northern Europe and captured in the Comunidad Valenciana, Spain in the 1994 autumn-winter season. Eight years after the Chernobyl accident, extensive agricultural lands in Europe are still contaminated and this study shows that there was a transfer of radioactive isotopes to the captured migratory song-thrushes. The whole-body dose commitment to humans consuming these birds is estimated.

Methods for Estimating Physicochemical Properties of Inorganic Chemicals of Environmental Concern.

DTIC Science & Technology

1984-06-01

atoms from a solid surface into an adjacent vapor phase. This effect has had significant implications for environmental pollution in the case of 210 ...for industrial 55 An um tt, i • purposes, 210 - polonium becomes unstable with respect to spontaneous migration through the air, leading to severe...1.6x10 s 8xlO- 210 -lead 210P 22 y 3.7x107 * 210 - polonium 210 -(5.30 14eV) 138 d 6.4x105 Po 91 AAfdr DL futt, imc Table 12. SELECTED RADIONUCLIDES WITH HALF

Science, policy, and stakeholders: developing a consensus science plan for Amchitka Island, Aleutians, Alaska.

PubMed

Burger, Joanna; Gochfeld, Michael; Kosson, David S; Powers, Charles W; Friedlander, Barry; Eichelberger, John; Barnes, David; Duffy, Lawrence K; Jewett, Stephen C; Volz, Conrad D

2005-05-01

With the ending of the Cold War, the US Department of Energy is responsible for the remediation of radioactive waste and disposal of land no longer needed for nuclear material production or related national security missions. The task of characterizing the hazards and risks from radionuclides is necessary for assuring the protection of health of humans and the environment. This is a particularly daunting task for those sites that had underground testing of nuclear weapons, where the radioactive contamination is currently inaccessible. Herein we report on the development of a Science Plan to characterize the physical and biological marine environment around Amchitka Island in the Aleutian chain of Alaska, where three underground nuclear tests were conducted (1965-1971). Information on the ecology, geology, and current radionuclide levels in biota, water, and sediment is necessary for evaluating possible current contamination and to serve as a baseline for developing a plan to ensure human and ecosystem health in perpetuity. Other information required includes identifying the location of the salt water/fresh water interface where migration to the ocean might occur in the future and determining groundwater recharge balances, as well as assessing other physical/geological features of Amchitka near the test sites. The Science Plan is needed to address the confusing and conflicting information available to the public about radionuclide risks from underground nuclear blasts in the late 1960s and early 1970s, as well as the potential for volcanic or seismic activity to disrupt shot cavities or accelerate migration of radionuclides into the sea. Developing a Science Plan involved agreement among regulators and other stakeholders, assignment of the task to the Consortium for Risk Evaluation with Stakeholder Participation, and development of a consensus Science Plan that dealt with contentious scientific issues. Involvement of the regulators (State of Alaska), resource trustees (U S Fish and Wildlife Service), representatives of the Aleut and Pribilof Island communities, and other stakeholders was essential for plan development and approval, although this created tensions because of the different objectives of each group. The complicated process of developing a Science Plan involved iterations and interactions with multiple agencies and organizations, scientists in several disciplines, regulators, and the participation of Aleut people in their home communities, as well as the general public. The importance of including all parties in all phases of the development of the Science Plan was critical to its acceptance by a broad range of regulators, agencies, resource trustees, Aleutian/Pribilof communities, and other stakeholders.

Patterns of Cs-137 and Sr-90 distribution in conjugated landscape systems

NASA Astrophysics Data System (ADS)

Korobova, E.

2012-04-01

The main goal of the study was to reveal spatial patterns of 137Cs and 90Sr distribution in soils and plants of conjugated landscapes and to use 137Cs as a tracer for natural migration and accumulation processes in the environment. The studies were based on presumptions that: 1) the environment consisted of interrelated bio- and geochemical fields of hierarchical structure depending on the level and age of factors responsible for spatial distribution of chemical elements; 2)distribution of technogenic radionuclides in natural landscapes depended upon the location and type of the initial source and radionuclide involvement in natural pathways controlled by the state and mobility of the typomorphic elements and water migration. Case studies were undertaken in areas subjected to contamination after the Chernobyl accident and in the estuary zones of the Yenisey and Pechora rivers. First observations in the Chernobyl remote zone in 1987-1989 demonstrated relation between the dose rate, 137Cs, 134Cs, 144Ce, 106Ru, 125Sb in soil cover and the location of the measured plot in landscape toposequence. Later study of 137Cs and 90Sr concentration and speciation confirmed different patterns of their distribution dependent upon the radioisotope, soil features and vegetation cover corresponding to the local landscape and landuse structure. Certain patterns in distribution and migration of 137Cs and 90Sr in soils and local food chain were followed in private farms situated in different landscape position [1]. Detailed study of 137Cs activity in forested site with a pronounced relief 20 and 25 years after the Chernobyl accident showed its stable polycentric structure in soils, mosses and litter which was sensitive to meso- and micro-relief features [2]. Radionuclide contamination of the lower Yenisey and Pechora studied along meridian landscape transects proved both areas be subjected to global 137Cs pollution while the Yenisey floodplain received additional regional contamination transported by the river [3]. Local zones of enhanced 137Cs accumulation in soil samples and some plant species were found in island systems, and the Yenisey upper delta island in particular. Hydromica identified in samples was considered significant for 137Cs accumulation in floodplain soils. The distinct tendency of secondary redistribution of the global 137Cs fallout in soils due to wind and water transport and subsequent accumulation, 137Cs accumulation in topsoil and slightly over the permafrost table were characteristic for both catchments. Therefore 137Cs proved to be an effective isotope tracer for studying and mapping technogenic contamination and the recent processes of water and particulate mass transport on the global, regional and local scales. Obtained results may be useful for monitoring, eco-geochemical evaluation and regionalizing of the areas contaminated by artificial radionuclides. 1. Korobova E.M., Ermakov A., Linnik V., 1998. Applied Geochemistry 13, .7, 803-814. 2. E.M. Korobova, S.L. Romanov, 2009. Chemometrics and Intelligent Laboratory Systems 99, 1-8. 3. E.M. Korobova, N.G. Ukraintseva, V.V. Surkov, J.E. Brown, W. Standring and A.P. Borisov, 2009. Eds: Mattia N. Gallo, Marco N. Ferrari. River Pollution Research Progress. Nova Science Publishers, Inc. N-Y, 91-156.

Radioecology of Vertebrate Animals in the Area Adjacent to the Chernobyl Nuclear Power Plant Site in 1986-2008

NASA Astrophysics Data System (ADS)

Farfan, E. B.; Gashchak, S. P.; Makliuk, Y. A.; Maksymenko, A. M.; Bondarkov, M. D.; Jannik, G. T.; Marra, J. C.

2009-12-01

A widespread environmental contamination of the areas adjacent to the Chernobyl Nuclear Power Plant (ChNPP) site attracted a great deal of publicity to the biological consequences of the ChNPP catastrophe. However, only a few studies focused on a detailed analysis of radioactive contamination of the local wild fauna and most of them were published in Eastern European languages, making them poorly accessible for Western scientists. In addition, evaluation of this information appears difficult due to significant differences in raw data acquisition and analysis methodologies and final data presentation formats. Using an integrated approach to assessment of all available information, the International Radioecology Laboratory scientists showed that the ChNPP accident had increased the average values of the animals 137Cs and 90Sr contamination by a factor of thousands, followed by its decrease by a factor of tens, primarily resulting from a decrease in the biological accessibility of the radionuclides. However, this trend depended on many factors. Plant and bottom feeding fish species were the first to reach the maximum contamination levels. No data are available on other vertebrates, but it can be assumed that the same trend was true for all plant feeding animals and animals searching for food on the soil surface. The most significant decrease of the average values occurred during the first 3-5 years after the accident and it was the most pronounced for elks and plant and plankton feeding fish. Their diet included elements “alienated” from the major radionuclide inventory; for example, upper soil layers and bottom deposits where the fallout that had originally precipitated on plants, water and soils gradually migrated. Further radionuclide penetration into deeper layers of soils and its bonding with their mineral components intensified decontamination of the fauna. It took a while for the contamination of predatory fish and mammals (wolves) to reach the maximum followed by its similar slow decrease. Currently, these species are found to be the most contaminated. Species that are environmentally connected with soils or bottom deposits (terrestrial amphibians, rodents, burrowing animals, birds searching for food in soils and underlying layers and wild hogs) also show relatively high contamination levels. In general, by the mid 1990’s, fluctuations in 137Cs contamination primarily depended on seasonal changes in food patterns, physiology and migration for animal species and on all these factors plus seasonal changes of water temperature and flood patterns for fish species. An increase of 90Sr biological accessibility in soils affected its average accumulation. Currently, due to stabilization of environmental complexes and processes in the region, long-term profiles of radioactive contamination of vertebrate animals mostly indicate a gradual decay of radionuclides, with further changes in biological accessibility of radionuclides being practically unnoticeable due to significant seasonal and geographical fluctuations of the contamination.

The behavior of U- and Th-series nuclides in groundwater

USGS Publications Warehouse

Porcelli, D.; Swarzenski, P.W.

2003-01-01

Groundwater has long been an active area of research driven by its importance both as a societal resource and as a component in the global hydrological cycle. Key issues in groundwater research include inferring rates of transport of chemical constituents, determining the ages of groundwater, and tracing water masses using chemical fingerprints. While information on the trace elements pertinent to these topics can be obtained from aquifer tests using experimentally introduced tracers, and from laboratory experiments on aquifer materials, these studies are necessarily limited in time and space. Regional studies of aquifers can focus on greater scales and time periods, but must contend with greater complexities and variations. In this regard, the isotopic systematics of the naturally occurring radionuclides in the U- and Th- decay series have been invaluable in investigating aquifer behavior of U, Th, and Ra. These nuclides are present in all groundwaters and are each represented by several isotopes with very different half-lives, so that processes occurring over a range of time-scales can be studied (Table 1⇓). Within the host aquifer minerals, the radionuclides in each decay series are generally expected to be in secular equilibrium and so have equal activities (see Bourdon et al. 2003). In contrast, these nuclides exhibit strong relative fractionations within the surrounding groundwaters that reflect contrasting behavior during release into the water and during interaction with the surrounding host aquifer rocks. Radionuclide data can be used, within the framework of models of the processes involved, to obtain quantitative assessments of radionuclide release from aquifer rocks and groundwater migration rates. The isotopic variations that are generated also have the potential for providing fingerprints for groundwaters from specific aquifer environments, and have even been explored as a means for calculating groundwater ages.

Numerical modeling of the radionuclide water pathway with HYDRUS and comparison with the IAEA model of SR 44.

PubMed

Merk, Rainer

2012-02-01

This study depicts a theoretical experiment in which the radionuclide transport through the porous material of a landfill consisting of concrete rubble (e.g., from the decommissioning of nuclear power plants) and the subsequent migration through the vadose zone and aquifer to a model well is calculated by means of the software HYDRUS-1D (Simunek et al., 2008). The radionuclides originally contained within the rubble become dissolved due to leaching caused by infiltrated rainwater. The resulting well-water contamination (in Bq/L) is calculated numerically as a function of time and location and compared with the outcome of a simplified analytic model for the groundwater pathway published by the IAEA (2005). Identical model parameters are considered. The main objective of the present work is to evaluate the predictive capacity of the more simple IAEA model using HYDRUS-1D as a reference. For most of the radionuclides considered (e.g., ¹²⁹I, and ²³⁹Pu), results from applying the IAEA model were found to be comparable to results from the more elaborate HYDRUS modeling, provided the underlying parameter values are comparable. However, the IAEA model appears to underestimate the effects resulting from, for example, high nuclide mobility, short half-life, or short-term variations in the water infiltration. The present results indicate that the IAEA model is suited for screening calculations and general recommendation purposes. However, the analysis of a specific site should be accompanied by detailed HYDRUS computer simulations. In all models considered, the calculation outcome largely depends on the choice of the sorption parameter K(d). Copyright © 2011 Elsevier Ltd. All rights reserved.

Potential migration of buoyant LNAPL from intermediate level waste (ILW) emplaced in a geological disposal facility (GDF) for U.K. radioactive waste.

PubMed

Benbow, Steven J; Rivett, Michael O; Chittenden, Neil; Herbert, Alan W; Watson, Sarah; Williams, Steve J; Norris, Simon

2014-10-15

A safety case for the disposal of Intermediate Level (radioactive) Waste (ILW) in a deep geological disposal facility (GDF) requires consideration of the potential for waste-derived light non-aqueous phase liquid (LNAPL) to migrate under positive buoyancy from disposed waste packages. Were entrainment of waste-derived radionuclides in LNAPL to occur, such migration could result in a shorter overall travel time to environmental or human receptors than radionuclide migration solely associated with the movement of groundwater. This paper provides a contribution to the assessment of this issue through multiphase-flow numerical modelling underpinned by a review of the UK's ILW inventory and literature to define the nature of the associated ILW LNAPL source term. Examination has been at the waste package-local GDF environment scale to determine whether proposed disposal of ILW would lead to significant likelihood of LNAPL migration, both from waste packages and from a GDF vault into the local host rock. Our review and numerical modelling support the proposition that the release of a discrete free phase LNAPL from ILW would not present a significant challenge to the safety case even with conservative approximations. 'As-disposed' LNAPL emplaced with the waste is not expected to pose a significant issue. 'Secondary LNAPL' generated in situ within the disposed ILW, arising from the decomposition of plastics, in particular PVC (polyvinyl chloride), could form the predominant LNAPL source term. Released high molecular weight phthalate plasticizers are judged to be the primary LNAPL potentially generated. These are expected to have low buoyancy-based mobility due to their very low density contrast with water and high viscosity. Due to the inherent uncertainties, significant conservatisms were adopted within the numerical modelling approach, including: the simulation of a deliberately high organic material--PVC content wastestream (2D03) within an annular grouted waste package vulnerable to LNAPL release; upper bound inventory estimates of LNAPLs; incorporating the lack of any hydraulic resistance of the package vent; the lack of any degradation of dissolved LNAPL; and, significantly, the small threshold displacement pressure assumed at which LNAPL is able to enter initially water-saturated pores. Initial scoping calculations on the latter suggested that the rate at which LNAPL is able to migrate from a waste package is likely to be very small and insignificant for likely representative displacement pressure data: this represents a key result. Adopting a conservative displacement pressure, however, allowed the effect of other features and processes in the system to be assessed. High LNAPL viscosity together with low density contrast with water reduces LNAPL migration potential. Migration to the host rock is less likely if waste package vent fluxes are small, solubility limits are high and path lengths through the backfill are short. The capacity of the system to dissolve all of the free LNAPL will, however, depend on groundwater availability. Even with the conservatisms invoked, the overall conclusion of model simulations of intact and compromised (cracked or corroded) waste packages, for a range of realistic ILW LNAPL scenarios, is that it is unlikely that significant LNAPL would be able to migrate from the waste packages and even more unlikely it would be sufficiently persistent to reach the host rock immediately beyond the GDF. Copyright © 2014. Published by Elsevier B.V.

Influence of heteroaggregation processes between intrinsic colloids and carrier colloids on cerium(III) mobility through fractured carbonate rocks.

PubMed

Tran, Emily; Klein Ben-David, Ofra; Teutch, Nadya; Weisbrod, Noam

2016-09-01

Colloid facilitated transport of radionuclides has been implicated as a major transport vector for leaked nuclear waste in the subsurface. Sorption of radionuclides onto mobile carrier colloids such as bentonite and humic acid often accelerates their transport through saturated rock fractures. Here, we employ column studies to investigate the impact of intrinsic, bentonite and humic acid colloids on the transport and recovery of Ce(III) through a fractured chalk core. Ce(III) recovery where either bentonite or humic colloids were added was 7.7-26.9% Ce for all experiments. Greater Ce(III) recovery was observed when both types of carrier colloids were present (25.4-37.4%). When only bentonite colloids were present, Ce(III) appeared to be fractionated between chemical sorption to the bentonite colloid surfaces and heteroaggregation of bentonite colloids with intrinsic carbonate colloids, precipitated naturally in solution. However, scanning electron microscope (SEM) images and colloid stability experiments reveal that in suspensions of humic acid colloids, colloid-facilitated Ce(III) migration results only from the latter attachment mechanism rather than from chemical sorption. This observed heteroaggregation of different colloid types may be an important factor to consider when predicting potential mobility of leaked radionuclides from geological repositories for spent fuel located in carbonate rocks. Copyright © 2016 Elsevier Ltd. All rights reserved.

Tracing long-term vadose zone processes at the Nevada Test Site, USA

PubMed Central

Hunt, James R.; Tompson, Andrew F. B.

2010-01-01

The nuclear weapons testing programme of the USA has released radionuclides to the subsurface at the Nevada Test Site. One of these tests has been used to study the hydrological transport of radionuclides for over 25 years in groundwater and the deep unsaturated zone. Ten years after the weapon’s test, a 16 year groundwater pumping experiment was initiated to study the mobility of radionuclides from that test in an alluvial aquifer. The continuously pumped groundwater was released into an unlined ditch where some of the water infiltrated into the 200 m deep vadose zone. The pumped groundwater had well-characterized tritium activities that were utilized to trace water migration in the shallow and deep vadose zones. Within the near-surface vadose zone, tritium levels in the soil water are modelled by a simple one-dimensional, analytical wetting front model. In the case of the near-surface soils at the Cambric Ditch experimental site, water flow and salt accumulation appear to be dominated by rooted vegetation, a mechanism not included within the wetting front model. Simulation results from a two-dimensional vadose groundwater flow model illustrate the dominance of vertical flow in the vadose zone and the recharge of the aquifer with the pumped groundwater. The long-time series of hydrological data provides opportunities to understand contaminant transport processes better in the vadose zone with an appropriate level of modelling. PMID:21785525

DOE Office of Scientific and Technical Information (OSTI.GOV)

Glucksberg, Nadia; Peters, Jay

The Conceptual Site Model (CSM) is a powerful tool for understanding the link between contamination sources, cleanup objectives, and ultimate site reuse. The CSM describes the site setting, geology, hydrogeology, potential sources, release mechanisms and migration pathways of contaminants. The CSM is needed to understand the extent of contamination and how receptors may be exposed to both radiological and chemical constituents. A key component of the CSM that is often overlooked concerns how the regulatory requirements drive remediation and how each has to be integrated into the CSM to ensure that all stakeholder requirements are understood and addressed. This papermore » describes how the use of the CSM helped reach closure and reuse at two facilities in Connecticut that are pursuing termination of their Nuclear Regulatory Commission (NRC) license. The two facilities are the Combustion Engineering Site, located in Windsor, Connecticut, (CE Windsor Site) and the Connecticut Yankee Atomic Power Company, located in Haddam Neck, Connecticut (CYAPCO). The closure of each of these facilities is regulated by four agencies: - Nuclear Regulatory Commission (NRC) - which requires cleanup levels for radionuclides to be protective of public health; - US Environmental Protection Agency (USEPA) - which requires cleanup levels for chemicals to be protective of public health and the environment; - Connecticut Department of Environmental Protection (CTDEP) Bureau of Air Management, Radiation Division - which requires cleanup levels for radionuclides to be protective of public health; and - Connecticut Department of Environmental Protection (CTDEP) Bureau of Water Protection and Land Reuse - which requires cleanup levels for chemicals to be protective of public health and the environment. Some of the radionuclides at the CE Windsor Site are also regulated under the Formerly Utilized Site Remedial Action Program (FUSRAP) under the Army Corps of Engineers. The remainder of this paper presents the similarities and differences between the CSMs for these two sites and how each site used the CSM to reach closure. Although each of these site have unique histories and physical features, the CSM approach was used to understand the geology, hydrogeology, migration and exposure pathways, and regulatory requirements to successfully characterize and plan closure of the sites. A summary of how these attributes affected site closure is provided.« less

Plutonium Particle Migration in the Shallow Vadose Zone: The Nevada Test Site as an Analog Site

NASA Astrophysics Data System (ADS)

Hunt, J. R.; Smith, D. K.

2004-12-01

The upper meter of the vadose zone in desert environments is the horizon where wastes have been released and human exposure is determined through dermal, inhalation, and food uptake pathways. This region is also characterized by numerous coupled processes that determine contaminant transport, including precipitation infiltration, evapotranspiration, daily and annual temperature cycling, dust resuspension, animal burrowing, and geochemical weathering reactions. While there is considerable interest in colloidal transport of minerals, pathogenic organisms, and contaminants in the vadose zone, there are limited field sites where the actual occurrence of contaminant migration can be quantified over the appropriate spatial and temporal scales of interest. At the US Department of Energy Nevada Test Site, there have been numerous releases of radionuclides since the 1950's that have become field-scale tracer tests. One series of tests was the four safety shots conducted in an alluvial valley of Area 11 in the 1950's. These experiments tested the ability of nuclear materials to survive chemical explosions without initiating fission reactions. Four above-ground tests were conducted and they released plutonium and uranium on the desert valley floor with only one of the tests undergoing some fission. Shortly after the tests, the sites were surveyed for radionuclide distribution on the land surface using aerial surveys and with depth. Additional studies were conducted in the 1970's to better understand the fate of plutonium in the desert that included studies of depth distribution and dust resuspension. More recently, plutonium particle distribution in the soil profile was detected using autoradiography. The results to date demonstrate the vertical migration of plutonium particles to depths in excess of 30 cm in this arid vadose zone. While plutonium migration at the Nevada Test Site has been and continues to be a concern, these field experiments have become analog sites for the release of radiological materials potentially important to consequence management investigations. In particular, these 50-year old experiments with long and detailed site investigations under relative undisturbed conditions offer insights into transport pathways that must be represented in simulation models that evaluate responses to radiological dispersal devices (RDDs). A compilation of the available site characterization data suggests additional experimental and modeling programs that can ultimately quantify the fate of contaminant particles released at the soil surface.

Radionuclide Migation Project 1984 progress report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buddemeier, R.W.; Isherwood, D.

1985-04-01

The report discusses the hydrogeologic settings and histories of studies associated with the Cheshire (U20n), Cambric (U5e), Nash (UE2ce), Bilby (U3cn), Bourbon (U7n), and Faultless (UC1) Events. Radionuclide and some chemical data are presented for water samples from cavity or chimney wells associated with the Cheshire, Cambric, and Bilby Events, and from satellite wells at the Cambric, Nash, Bibly, Bourbon, and Faultless Event sites. The report also gives the results of studies of specific sampling or analytical methodologies. These studies demonstrated that the apparent migration of /sup 155/Eu is an artfact of spectrometric misidentification of gamma- and x-ray peaks frommore » other constituents. A potential problem with atmospheric contamination of samples collected with evacuated thief samples was also identified. Ultrafiltration techniques were applied to some of the Cheshire cavity samples collected, and preliminary results suggest that substantial amounts of activity may be associated with colloidal particles in the size range of 0.006 to 0.45 ..mu..m. A study has begun of the recharge of effluent water from RNM-2S (Cambric satellite well) into the desert floor as a result of nine years of continuous pumping. This report gives the initial results of unsaturated zone studies showing the propagation of moisture and tritium fronts through the shallow soil. Geochemical modeling of the behavior of ruthenium and technetium was carried out, with particular emphasis on the identification of ionic species that would be potentially mobile under NTS ground-water conditions. The report compares the results with observations of ruthenium migration to the Cambric satellite well.« less

Distribution and migration of 239+240Pu in abiotic components of the Black Sea ecosystems during the post-Chernobyl period.

PubMed

Tereshchenko, N N; Gulin, S B; Proskurnin, V Yu

2018-08-01

Distribution of 239,240 Pu in abiotic components (water and bottom sediment) of the Black Sea ecosystems was studied during the post-Chernobyl period at different offshore and near-shore locations. The trends of these radionuclides accumulation by sediments were analyzed. The spatial-temporal changes in the 239,240 Pu distribution as well as effective half-life for these radionuclides in the Black Sea surface water in deep-sea area are presented. The estimations of the average annual removal fluxes of the 239,240 Pu into the bottom sediments were obtained. The Black Sea sediments were characterized by a higher 239,240 Pu concentration factor (C f  ≈ n·10 4 -n·10 6 ) and radiocapacity factor (F( 239,240 Pu) was about 99.9% on the shelf, 94.5-99.1% on deep-sea basin for silty and 94.6-98.9% on the shelf for sandy bottom sediments) as compared with C f and F for 137 Cs and 90 Sr. Silty bottom sediments play the role of 239,240 Pu main depot in the Black Sea ecosystem. The studied radioecological characteristics of Pu allowed us to define the type of plutonium biogeochemical behavior in the Black Sea as a pedotropic one. The results of this complex radioecological monitoring of 239+240 Pu contamination in the Black Sea and their analysis makes it possible to understand the plutonium redistribution pathways which will enable to carry out the tracing of its migration within the ecosystems. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of Intrinsic Colloid Formation on Migration of Cerium through Fractured Carbonate Rock.

PubMed

Tran, Emily L; Klein-BenDavid, Ofra; Teutsch, Nadya; Weisbrod, Noam

2015-11-17

Migration of colloids may facilitate the transport of radionuclides leaked from near surface waste sites and geological repositories. Intrinsic colloids are favorably formed by precipitation with carbonates in bicarbonate-rich environments, and their migration may be enhanced through fractured bedrock. The mobility of Ce(III) as an intrinsic colloid was studied in an artificial rainwater solution through a natural discrete chalk fracture. The results indicate that at variable injection concentrations (between 1 and 30 mg/L), nearly all of the recovered Ce takes the form of an intrinsic colloid of >0.45 μm diameter, including in those experiments in which the inlet solution was first filtered via 0.45 μm. In all experiments, these intrinsic colloids reached their maximum relative concentrations prior to that of the Br conservative tracer. Total Ce recovery from experiments using 0.45 μm filtered inlet solutions was only about 0.1%, and colloids of >0.45 μm constituted the majority of recovered Ce. About 1% of Ce was recovered when colloids of >0.45 μm were injected, indicating the enhanced mobility and recovery of Ce in the presence of bicarbonate.

Inventory and vertical migration of 90Sr fallout and 137Cs/90Sr ratio in Spanish mainland soils.

PubMed

Herranz, M; Romero, L M; Idoeta, R; Olondo, C; Valiño, F; Legarda, F

2011-11-01

In this paper the inventory of (90)Sr in 34 points distributed along the Spanish peninsular territory is presented. Obtained values range between 173 Bq/m(2) and 2047 Bq/m(2). From these data set and those (137)Cs data obtained in a previous work the (137)Cs/(90)Sr activity ratio has been established, laying this value between 0.9 and 3.6. Also the migration depth of both radionuclides has been analysed obtaining for (137)Cs an average value 57% lower than that obtained for (90)Sr. Additionally, this paper presents the results obtained in 11 sampling points in which the activity vertical profile has been measured. These profiles have been analysed to state the behaviour of strontium in soils and after, by using a convective-diffusive model, the parameters of the model which governs the vertical migration of (90)Sr in the soil, v (apparent convection velocity) and D (apparent diffusion coefficient) have been evaluated. Mean values obtained are 0.20 cm/year and 3.67 cm(2)/year, respectively. Copyright © 2011 Elsevier Ltd. All rights reserved.

The chemical behavior of the transuranic elements and the barrier function in natural aquifer systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jewett, J.R.

1997-09-17

In a geological repository for long-lived radioactive wastes, such as actinides and certain fission products, most of the stored radionuclides remain immobile in the particular geological formation. If any of these could possibly become mobile, only trace concentrations of a few radionuclides would result. Nevertheless, with an inventory in the repository of many tonnes of transuranic elements, the amounts that could disperse cannot be neglected. A critical assessment of the chemical behavior of these nuclides, especially their migration properties in the aquifer system around the repository site, is mandatory for analysis of the long-term safety. The chemistry requited for thismore » includes many geochemical multicomponent reactions that are so far only partially understood and [which] therefore can be quantified only incompletely. A few of these reactions have been discussed in this paper based on present knowledge. If a comprehensive discussion of the subject is impossible because of this [lack of information], then an attempt to emphasize the importance of the predominant geochemical reactions of the transuranic elements in various aquifer systems should be made.« less

Modeling of transport phenomena in concrete porous media.

PubMed

Plecas, Ilija

2014-02-01

Two fundamental concerns must be addressed when attempting to isolate low-level waste in a disposal facility on land. The first concern is isolating the waste from water, or hydrologic isolation. The second is preventing movement of the radionuclides out of the disposal facility, or radionuclide migration. Particularly, we have investigated here the latter modified scenario. To assess the safety for disposal of radioactive waste-concrete composition, the leakage of 60Co from a waste composite into a surrounding fluid has been studied. Leakage tests were carried out by the original method, developed at the Vinča Institute. Transport phenomena involved in the leaching of a radioactive material from a cement composite matrix are investigated using three methods based on theoretical equations. These are: the diffusion equation for a plane source: an equation for diffusion coupled to a first-order equation, and an empirical method employing a polynomial equation. The results presented in this paper are from a 25-y mortar and concrete testing project that will influence the design choices for radioactive waste packaging for a future Serbian radioactive waste disposal center.

Analysis of trace neptunium in the vicinity of underground nuclear tests at the Nevada National Security Site.

PubMed

Zhao, P; Tinnacher, R M; Zavarin, M; Kersting, A B

2014-11-01

A high sensitivity analytical method for (237)Np analysis was developed and applied to groundwater samples from the Nevada National Security Site (NNSS) using short-lived (239)Np as a yield tracer and HR magnetic sector ICP-MS. The (237)Np concentrations in the vicinity of the Almendro, Cambric, Dalhart, Cheshire, and Chancellor underground nuclear test locations range from <4 × 10(-4) to 2.6 mBq/L (6 × 10(-17)-4.2 × 10(-13) mol/L). All measured (237)Np concentrations are well below the drinking water maximum contaminant level for alpha emitters identified by the U.S. EPA (560 mBq/L). Nevertheless, (237)Np remains an important indicator for radionuclide transport rates at the NNSS. Retardation factor ratios were used to compare the mobility of (237)Np to that of other radionuclides. The results suggest that (237)Np is less mobile than tritium and other non-sorbing radionuclides ((14)C, (36)Cl, (99)Tc and (129)I) as expected. Surprisingly, (237)Np and plutonium ((239,240)Pu) retardation factors are very similar. It is possible that Np(IV) exists under mildly reducing groundwater conditions and exhibits a retardation behavior that is comparable to Pu(IV). Independent of the underlying process, (237)Np is migrating downgradient from NNSS underground nuclear tests at very low but measureable concentrations. Copyright © 2014 The Authors. Published by Elsevier Ltd.. All rights reserved.

Spatial variability of the dose rate from (137)Cs fallout in settlements in Russia and Belarus more than two decades after the Chernobyl accident.

PubMed

Bernhardsson, C; Rääf, C L; Mattsson, S

2015-11-01

Radionuclides from the 1986 Chernobyl accident were released and dispersed during a limited period of time, but under widely varying weather conditions. As a result, there was a high geographical variation in the deposited radioactive fallout per unit area over Europe, depending on the released composition of fission products and the weather during the 10 days of releases. If the plume from Chernobyl coincided with rain, then the radionuclides were unevenly distributed on the ground. However, large variations in the initial fallout also occurred locally or even on a meter scale. Over the ensuing years the initial deposition may have been altered further by different weathering processes or human activities such as agriculture, gardening, and decontamination measures. Using measurements taken more than two decades after the accident, we report on the inhomogeneous distribution of the ground deposition of the fission product (137)Cs and its influence on the dose rate 1 m above ground, on both large and small scales (10ths of km(2) - 1 m(2)), in the Gomel-Bryansk area close to the border between Belarus and Russia. The dose rate from the deposition was observed to vary by one order of magnitude depending on the size of the area considered, whether human processes were applied to the surface or not, and on location specific properties (e.g. radionuclide migration in soil). Copyright © 2015 Elsevier Ltd. All rights reserved.

Chemical composition of drinking water as a possible environment-specific factor modifying the thyroid risk in the areas subjected to radioiodine contamination

NASA Astrophysics Data System (ADS)

Kolmykova, Lyudmila; Korobova, Elena; Ryzhenko, Boris

2015-04-01

Water is one of the main natural agents providing chemical elements' migration in the environment and food chains. In our opinion a study of spatial variation of the essential trace elements in local drinking water is worth considering as the factor that may contribute to variation of the health risk in areas contaminated by radionuclides and radioiodine in particular. Radioiodine was proved to increase the risk of thyroid cancer among children who lived in areas contaminated during the Chernobyl accident. It was also shown that low stable iodine status of the contaminated area and population also contributed to the risk of this disease in case of radionuclide contamination. The goal of the study was to investigate chemical composition of the drinking water in rural settlements of the Bryansk oblast' subjected to radioiodine contamination and to evaluate speciation of stable I and Se on the basis of their total concentration and chemical composition of the real water samples with the help of thermodynamic modelling. Water samples were collected from different aquifers discharging at different depths (dug wells, local private bore holes and water pipes) in rural settlements located in areas with contrasting soil iodine status. Thermodynamic modelling was performed using original software (HCh code of Y.Shvarov, Moscow State University, RUSSIA) incorporating the measured pH, Corg and elements' concentration values. Performed modelling showed possibility of formation of complex CaI+ ion in aqueous phase, I sorption by goethite and transfer of Se to solid phase as FeSe in the observed pH-Eh conditions. It helped to identify environmental conditions providing high I and Se mobility and their depletion from natural waters. Both the experimental data and modeling showed that I and Se migration and deficiency in natural water is closely connected to pH, Eh conditions and the concentration of typomorphic chemical elements (Ca, Mg, Fe) defining the class of water migration in landscapes (according Perel'man, 1975). Obtained data will be used for evaluation of contribution of I and Se status of drinking water to the risk of thyroid diseases among local population.

Geoinformational modelling of the land use of Polesye and Opolje landscapes in Bryansk region (Russia) under conditions of 137Cs radionuclides contamination

NASA Astrophysics Data System (ADS)

Nenko, Christina; Linnik, Vitaliy; Volkova, Nadezhda

2015-04-01

Significant part of Russian Federation was contaminated by 137Cs radionuclides due to Chernobyl disaster in 1986. South-western part of Bryansk region has suffered the most. Study area (the central part of Bryansk region, Polesye and high plains landscapes) is situated outside the officially specified zone of contamination with contamination levels under 1 Ci / km2. Nevertheless, such contamination levels (which are 20 times greater than levels of global fallout) require particular attention as it may contain a threat of the land use and the health of population, living within the territory. Radioactive contamination within the model area was formed as a result of a "dry" deposition from the atmosphere. Consequently, the initial contamination of soil by isotopes 137Cs, unlike the western part of the Bryansk region, was spread relatively equally. The main part of 137Cs (up to 90%) in natural landscapes is contained in the top 5 cm of soil, which itself creates danger of biogeochemical migration from soil to plants. In agricultural landscapes under cultivation 137Cs is uniformly spread within a 20 cm layer of soil and can also come from soil to plants grown in the fields. The area of radioactive contamination that was formed during the period of deposition (late April - early May 1986), is exposed to the processes of secondary redistribution. It is influenced by several factors as topography, vegetation type, proportion of arable soils, soil humidity, soil texture etc. In the presented study there was evaluated the impact of these factors on the secondary redistribution of 137Cs. Sustainable development of agricultural production in the contaminated territories requires managing a number of measures to reduce radiation risks to the population. Regarding this point the greatest threat may be represented by milk production, as well as picking berries and mushrooms. Planning of the sustainable use of the territory requires an evaluation of contamination levels within the existing agricultural lands. For this purpose, geographic information system (GIS) of the territory was created. It contains following layers: aero-gamma spectrometry data with interval of 100 m; soil types (scale 1: 50,000); relief (SRTM data); schematic map of agricultural lands and forests. The analysis of the secondary redistribution of radionuclides was conducted for the radio-ecological zoning of the territory, as well as the stock of 137Cs was calculated according to types of land use. It made it possible to evaluate the contamination of milk (using transfer coefficients "soil-plant-milk") for different natural landscapes. Evaluation of factors of radionuclides' migration in landscape also allows to predict possible trends in distribution of contamination and to develop recommendations regarding the future use of the territory.

Utilizing hydrologic, statistical, and geochemical tools to assess uranium mobility in surface and near-surface environments

NASA Astrophysics Data System (ADS)

Naftz, D. L.; Walton-Day, K. E.; Fuller, C.; Dam, W. L.; Briggs, M. A.; Snyder, T.

2015-12-01

Legacy uranium (U) mining and processing activities have resulted in soil and water contamination on Federal, state, and tribal lands in the western United States. Sites include legacy mill sites associated with U extraction now managed by the Department of Energy and thousands of waste dumps associated with U exploration, mining, and processing. Recently (2012), over 400,000 hectares of federally managed land in northern Arizona was withdrawn from consideration of mining for a 20-year period to protect the Grand Canyon watershed from potentially adverse effects of U mineral exploration and development. Ore from active and recently active U mines in the Colorado Plateau, the Henry Mountains Complex, and the Arizona Strip is transported to the only currently (2015) active conventional mill site in the western United States, located in Utah. Previous and ongoing U.S. Geological Survey assessments to examine U mobility at a variety of legacy and active sites associated with ore exploration, extraction, and processing will be presented as field-scale examples. Topics associated with site investigations will include: (1) offsite migration of radionuclides associated with the operation of the White Mesa U mill; (2) long-term contaminant transport from legacy U waste dumps on Bureau of Land Management regulated land in Utah; (3) application of incremental soil sampling techniques to determine pre- and post-mining radionuclide levels associated with planned and operating U mines in northern Arizona; (4) application of fiber optic digital temperature sensing equipment to identify areas where shallow groundwater containing elevated U levels may be discharging to a river adjacent to a reclaimed mill site in central Wyoming; and (5) field-scale manipulation of groundwater chemistry to limit U migration from a legacy upgrader site in southeastern Utah.

Effect of Iron and Carbonation of the Diffusion of Iodine and Rhenium in Waste Encasement Concrete and Soil Fill Material under Hydraulically Unsaturated Conditions

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wellman, Dawn M.; Parker, Kent E.; Powers, Laura

2008-07-31

Assessing long-term performance of Category 3 cement wasteforms and accurate prediction for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e. sorption or precipitation). A set of sediment-concrete half-cell diffusion experiments was conducted under unsaturated conditions (4% and 7% by weight moisture content) using carbonated and non-carbonated concrete-soil half-cells. Results indicate the behavior of rhenium and iodine release was comparable within a given half-cell test. Diffusivity in soil is a function of moisture content; a 3% increase in moisture content affords a one to two order of magnitude increase in diffusivity. Release of iodine and rheniummore » was 1 to 3 orders of magnitude less from non-carbonated, relative to carbonated, concrete monoliths. Inclusion of iron in non-carbonate monoliths resulted in the lowest concrete diffusivity values for both iodine and rhenium. This suggests that in the presence of iron, iodine and rhenium are converted to reduced species, which are less soluble and better retained within the concrete monolith. The release of iodine and rhenium was greatest from iron-bearing, carbonated concrete monoliths, suggesting carbonation negates the effect of iron on the retention of iodine and rhenium within concrete monoliths. This is likely due to enhanced formation of microcracks in the presence of iron, which provide preferential paths for contaminant migration. Although the release of iodine and rhenium were greatest from carbonated concrete monoliths containing iron, the migration of iodine and rhenium within a given half-cell is dependent on the moisture content, soil diffusivity, and diffusing species.« less

Investigating the Potential Barrier Function of Nanostructured Materials Formed in Engineered Barrier Systems (EBS) Designed for Nuclear Waste Isolation.

PubMed

Cuevas, Jaime; Ruiz, Ana Isabel; Fernández, Raúl

2018-02-21

Clay and cement are known nano-colloids originating from natural processes or traditional materials technology. Currently, they are used together as part of the engineered barrier system (EBS) to isolate high-level nuclear waste (HLW) metallic containers in deep geological repositories (DGR). The EBS should prevent radionuclide (RN) migration into the biosphere until the canisters fail, which is not expected for approximately 10 3  years. The interactions of cementitious materials with bentonite swelling clay have been the scope of our research team at the Autonomous University of Madrid (UAM) with participation in several European Union (EU) projects from 1998 up to now. Here, we describe the mineral and chemical nature and microstructure of the alteration rim generated by the contact between concrete and bentonite. Its ability to buffer the surrounding chemical environment may have potential for further protection against RN migration. © 2018 The Chemical Society of Japan & Wiley-VCH Verlag GmbH & Co. KGaA, Weinheim.

Fukushima derived radiocesium in subsistence-consumed northern fur seal and wild celery

DOE PAGES

Ruedig, Elizabeth; Duncan, Colleen; Dickerson, Bobette; ...

2015-11-28

In July 2014, our investigative team traveled to St. Paul Island, Alaska to measure concentrations of radiocesium in wild-caught food products, primarily northern fur seal (Callorhinus ursinus). The 2011 Fukushima Daiichi Nuclear Power Plant accident released radiocesium into the atmosphere and into the western Pacific Ocean; other investigators have detected Fukushima-derived radionuclides in a variety of marine products harvested off the western coast of North America. We tested two subsistence-consumed food products from St. Paul Island, Alaska for Fukushima-derived radionuclides: 54 northern fur seal, and nine putchki (wild celery, Angelica lucida) plants. Individual northern fur seal samples were below minimummore » detectable activity concentrations of 137Cs and 134Cs, but when composited, northern fur seal tissues tested positive for trace quantities of both isotopes. Radiocesium was detected at an activity concentration of 37.2 mBq 134Cs kg -1 f.w. (95% CI: 35.9–38.5) and 141.2 mBq 137Cs kg -1f.w. (95% CI: 135.5–146.8). The measured isotopic ratio, decay-corrected to the date of harvest, was 0.26 (95% CI: 0.25–0.28). The Fukushima nuclear accident released 134Cs and 137Cs in roughly equal quantities, but by the date of harvest in July 2014, this ratio was 0.2774, indicating that this population of seals has been exposed to small quantities of Fukushima-derived radiocesium. Activity concentrations of both 134Cs and 137Cs in putchki were below detection limits, even for composited samples. Northern fur seal is known to migrate between coastal Alaska and Japan and the trace 134Cs in northern fur seal tissue suggests that the population under study had been minimally exposed Fukushima-derived radionuclides. Despite this inference, the radionuclide quantities detected are small and no impact is expected as a result of the measured radiation exposure, either in northern fur seal or human populations consuming this species.« less

Fukushima derived radiocesium in subsistence-consumed northern fur seal and wild celery

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruedig, Elizabeth; Duncan, Colleen; Dickerson, Bobette

In July 2014, our investigative team traveled to St. Paul Island, Alaska to measure concentrations of radiocesium in wild-caught food products, primarily northern fur seal (Callorhinus ursinus). The 2011 Fukushima Daiichi Nuclear Power Plant accident released radiocesium into the atmosphere and into the western Pacific Ocean; other investigators have detected Fukushima-derived radionuclides in a variety of marine products harvested off the western coast of North America. We tested two subsistence-consumed food products from St. Paul Island, Alaska for Fukushima-derived radionuclides: 54 northern fur seal, and nine putchki (wild celery, Angelica lucida) plants. Individual northern fur seal samples were below minimummore » detectable activity concentrations of 137Cs and 134Cs, but when composited, northern fur seal tissues tested positive for trace quantities of both isotopes. Radiocesium was detected at an activity concentration of 37.2 mBq 134Cs kg -1 f.w. (95% CI: 35.9–38.5) and 141.2 mBq 137Cs kg -1f.w. (95% CI: 135.5–146.8). The measured isotopic ratio, decay-corrected to the date of harvest, was 0.26 (95% CI: 0.25–0.28). The Fukushima nuclear accident released 134Cs and 137Cs in roughly equal quantities, but by the date of harvest in July 2014, this ratio was 0.2774, indicating that this population of seals has been exposed to small quantities of Fukushima-derived radiocesium. Activity concentrations of both 134Cs and 137Cs in putchki were below detection limits, even for composited samples. Northern fur seal is known to migrate between coastal Alaska and Japan and the trace 134Cs in northern fur seal tissue suggests that the population under study had been minimally exposed Fukushima-derived radionuclides. Despite this inference, the radionuclide quantities detected are small and no impact is expected as a result of the measured radiation exposure, either in northern fur seal or human populations consuming this species.« less

Fukushima derived radiocesium in subsistence-consumed northern fur seal and wild celery.

PubMed

Ruedig, Elizabeth; Duncan, Colleen; Dickerson, Bobette; Williams, Michael; Gelatt, Thomas; Bell, Justin; Johnson, Thomas E

2016-02-01

In July 2014, our investigative team traveled to St. Paul Island, Alaska to measure concentrations of radiocesium in wild-caught food products, primarily northern fur seal (Callorhinus ursinus). The 2011 Fukushima Daiichi Nuclear Power Plant accident released radiocesium into the atmosphere and into the western Pacific Ocean; other investigators have detected Fukushima-derived radionuclides in a variety of marine products harvested off the western coast of North America. We tested two subsistence-consumed food products from St. Paul Island, Alaska for Fukushima-derived radionuclides: 54 northern fur seal, and nine putchki (wild celery, Angelica lucida) plants. Individual northern fur seal samples were below minimum detectable activity concentrations of (137)Cs and (134)Cs, but when composited, northern fur seal tissues tested positive for trace quantities of both isotopes. Radiocesium was detected at an activity concentration of 37.2 mBq (134)Cs kg(-1) f.w. (95% CI: 35.9-38.5) and 141.2 mBq (137)Cs kg(-1) f.w. (95% CI: 135.5-146.8). The measured isotopic ratio, decay-corrected to the date of harvest, was 0.26 (95% CI: 0.25-0.28). The Fukushima nuclear accident released (134)Cs and (137)Cs in roughly equal quantities, but by the date of harvest in July 2014, this ratio was 0.2774, indicating that this population of seals has been exposed to small quantities of Fukushima-derived radiocesium. Activity concentrations of both (134)Cs and (137)Cs in putchki were below detection limits, even for composited samples. Northern fur seal is known to migrate between coastal Alaska and Japan and the trace (134)Cs in northern fur seal tissue suggests that the population under study had been minimally exposed Fukushima-derived radionuclides. Despite this inference, the radionuclide quantities detected are small and no impact is expected as a result of the measured radiation exposure, either in northern fur seal or human populations consuming this species. Published by Elsevier Ltd.

Contaminated groundwater characterization at the Chalk River Laboratories, Ontario, Canada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schilk, A.J.; Robertson, D.E.; Thomas, C.W.

1993-03-01

The licensing requirements for the disposal of low-level radioactive waste (10 CFR 61) specify the performance objectives and technical requisites for federal and commercial land disposal facilities, the ultimate goal of which is to contain the buried wastes so that the general population is adequately protected from harmful exposure to any released radioactive materials. A major concern in the operation of existing and projected waste disposal sites is subterranean radionuclide transport by saturated or unsaturated flow, which could lead to the contamination of groundwater systems as well as uptake by the surrounding biosphere, thereby directly exposing the general public tomore » such materials. Radionuclide transport in groundwater has been observed at numerous commercial and federal waste disposal sites [including several locations within the waste management area of Chalk River Laboratories (CRL)], yet the physico-chemical processes that lead to such migration are still not completely understood. In an attempt to assist in the characterization of these processes, an intensive study was initiated at CRL to identify and quantify the mobile radionuclide species originating from three separate disposal sites: (a) the Chemical Pit, which has received aqueous wastes containing various radioisotopes, acids, alkalis, complexing agents and salts since 1956, (b) the Reactor Pit, which has received low-level aqueous wastes from a reactor rod storage bay since 1956, and (c) the Waste Management Area C, a thirty-year-old series of trenches that contains contaminated solid wastes from CRL and various regional medical facilities. Water samples were drawn downgradient from each of the above sites and passed through a series of filters and ion-exchange resins to retain any particulate and dissolved or colloidal radionuclide species, which were subsequently identified and quantified via radiochemical separations and gamma spectroscopy. These groundwaters were also analyzed for anions, trace metals, Eh, pH, alkalinity and dissolved oxygen.« less

Visualization of Macrophage Recruitment to Inflammation Lesions using Highly Sensitive and Stable Radionuclide-Embedded Gold Nanoparticles as a Nuclear Bio-Imaging Platform

PubMed Central

Lee, Sang Bong; Lee, Ho Won; Singh, Thoudam Debraj; Li, Yinghua; Kim, Sang Kyoon; Cho, Sung Jin; Lee, Sang-Woo; Jeong, Shin Young; Ahn, Byeong-Cheol; Choi, Sangil; Lee, In-Kyu; Lim, Dong-Kwon; Lee, Jaetae; Jeon, Yong Hyun

2017-01-01

Reliable and sensitive imaging tools are required to track macrophage migration and provide a better understating of their biological roles in various diseases. Here, we demonstrate the possibility of radioactive iodide-embedded gold nanoparticles (RIe-AuNPs) as a cell tracker for nuclear medicine imaging. To demonstrate this utility, we monitored macrophage migration to carrageenan-induced sites of acute inflammation in living subjects and visualized the effects of anti-inflammatory agents on this process. Macrophage labeling with RIe-AuNPs did not alter their biological functions such as cell proliferation, phenotype marker expression, or phagocytic activity. In vivo imaging with positron-emission tomography revealed the migration of labeled macrophages to carrageenan-induced inflammation lesions 3 h after transfer, with highest recruitment at 6 h and a slight decline of radioactive signal at 24 h; these findings were highly consistent with the data of a bio-distribution study. Treatment with dexamethasone (an anti-inflammation drug) or GSK5182 (an ERRγ inverse agonist) hindered macrophage recruitment to the inflamed sites. Our findings suggest that a cell tracking strategy utilizing RIe-AuNPs will likely be highly useful in research related to macrophage-related disease and cell-based therapies. PMID:28382164

Biotesting of radioactively contaminated forest soils using barley-based bioassay

NASA Astrophysics Data System (ADS)

Mel'nikova, T. V.; Polyakova, L. P.; Oudalova, A. A.

2017-01-01

Findings from radioactivity and phytotoxicity study are presented for soils from nine study-sites of the Klintsovsky Forestry located in the Bryansk region that were radioactively contaminated after the Chernobyl accident. According to the bioassay based on barley as test-species, stimulating effect of the soils analyzed is revealed for biological indexes of the length of barley roots and sprouts. From data on 137Cs specific activities in soils and plant biomass, the migration potential of radionuclide in the "soil-plant" system is assessed as a transfer factor. With correlation analysis, an impact of 137Cs in soil on the biological characteristics of barley is estimated.

Investigation of radionuclides and anthropic tracer migration in groundwater at the Chernobyl site

NASA Astrophysics Data System (ADS)

Le Gal La Salle, Corinnne; Simonucci, Caroline; Roux, Céline; Bugai, Dmitry; Aquilina, Luc; Fourré, Elise; Jean-Baptiste, Philippe; Labasque, Thierry; Michelot, Jean-Luc; Fifield, Keith; Team Aster Team; Van Meir, Nathalie; Kashparov, Valeriy; Diez, Olivier; Bassot, Sylvain; Lancelot, Joel

2013-04-01

Following the reactor 4 explosion of the Chernobyl Nuclear Power Plant (ChNPP), at least 1019 Bq of radionuclides (RN) were released in the environment. In order to protect workers and prevent further atmospheric RN dispersion in the area adjacent to the ChNPP, contaminated wastes including fuel particles, topsoil layer and forest remains were buried in approximately 800 shallow trenches in the sand formation in the Red Forest waste dump site [1]. No containment measures were taken, and since then RN have leaked to the unsaturated zone and to the groundwater. Since 1999, migration of RN in the vicinity of the trench 22 at Red Forest site has been investigated within the frame of the EPIC program carried out by IRSN in collaboration with UIAR and IGS [2, 3]. A plume of 90Sr was shown downgradient from the trench 22 with activites reaching 3750 Bq/L [2]. In 2008, further studies were initiated through the TRASSE research group, based on a collaboration between IRSN and CNRS. These programs aim at combining groundwater dating with RN migration monitoring studies in order to constrain RN transport models [3]. Groundwater residence time was investigated based on 3H/He and CFC. Both tracers led to ages ranging from modern (1-3 y) at 2 m depth below the groundwater table to significantly higher apparent ages of 50-60 y at 27 m below the groundwater table [3]. 36Cl/Cl ratios 2 to 4 orders of magnitude higher than the theoretical natural ratio are measured in groundwater. Similarly, SF6 shows concentrations as high as 1200 pptv while natural concentrations are in the order of 6-7 pptv. Based on apparent groundwater ages, both contaminations are linked to the Chernobyl explosion. Hence those tracers show excellent potential to constrain conservative and reactive transport, respectively. In contrast, 238U/235U ratio down gradient from trench 22 remains similar to the natural ratio. This suggests that either most of the U contained in the trench is in a non soluble form, associated with U-Zr matrix fuel particles [5] and/or that migration of U is limited due to redox processes and/or microbial activity. The above described experience of post-Chernobyl studies shows that a combined analysis of radionuclides, natural and anthropogenic tracers provides an efficient research tool to better understand and quantify contaminant transport processes in the geo-sphere. Similar approaches can be applied to the study transport of RN in the subsurface, issued from both, diffuse (contaminated watersheds) and point (damaged NPP and fuel storage units) radioactive sources produced by the Fukushima accident. References [1] Dzhepo S. P., Skalskyy A., 2002, In Chernobyl disaster and groundwater, Shestopalov, V., Ed. A.A. Balkema: Lisse, pp 25-70. [2] Dewiere L., Bugai D. et al., 2004, J. Environ. Radioactiv., 74, (1-3), 139-150. [3] Van Meir N., Bugaï, et al., 2009, in: Oughton, D.H., Kashparov, V. (Eds.), Radioactive Particles in the Environment. Springer Science+Business Media B.V., pp.197-208. [4] Le Gal La Salle C., Aquilina L., et al., 2012, Appl. Geochem., 27 1304-1319. [5] Kashparov V.A., Ahamdach N., et. al., 2004, J. Environ. Radioactiv., 72, 335-353.

Radionuclide concentrations in underground waters of Mururoa and Fangataufa Atolls.

PubMed

Mulsow, S; Coquery, M; Dovlete, C; Gastaud, J; Ikeuchi, Y; Pham, M K; Povinec, P P

1999-09-30

In 1997 an expedition to Mururoa and Fangataufa Atolls was carried out to sample underground waters from cavity-chimneys and carbonate monitoring wells. The aim of this study was to determine the prevailing concentration and distribution status of radionuclides. Elemental analysis of interstitial waters was carried out in the water fraction as well as in particles collected at 11 underground monitoring wells. 238Pu, 239,240Pu, 241Am, 137Cs, 90Sr, 3H, 125Sb, 155Eu and 60Co were analyzed in both fractions by alpha-, beta- and gamma-spectrometry. Measurements showed that at 60% of the sites, pH and Eh seemed to be related to tidal cycles; in contrast HTO was constant during the sampling time. Interstitial waters from carbonates and transition zones shared similar chemical composition that were not different from that of the surrounding seawater. Waters collected from basalt cavities left after nuclear tests, (Aristee and Ceto) have a different chemical signature characterized by a deficiency in Mg, K and SO4 as well as enrichment in Sr, Si, Al and Cl compared to the rest of the stations. Radionuclide concentrations present in both, water and particulate fractions, were significantly higher at Ceto and Aristee than at any other monitoring wells, except for Fuseau and Mitre monitoring wells (Fangataufa) where values similar to Ceto were found (e.g. 239,240Pu: > 20 mBq g-1). Considering that Pu isotopes showed high Kd values compared to non-sorbing radionuclides such as 3H, 90Sr and 137Cs it is very unlikely that migration from cavities to monitoring wells accounts for the concentration of Pu isotopes and Am at Fuseau 30 and Mitre 27. Perhaps the contact of lagoon waters with the well before sealing could be a possible source of the transuranics found at these sites. The 238Pu/239,240Pu ratios measured in the particles were similar to that of the lagoon (0.38), thus supporting this hypothesis. The fact that transuranics were found only in the particle fraction, in the water (colloids included) these radionuclides were below detection limits, may be accounted for the conspicuous quantity of iron oxy-hydroxides present in the particulate fraction that under the appropriate redox conditions may be interacting selectively with elements in solution (scavenging) resulting in the enhanced transuranic signal. While transuranics have been found in places of their origin, radionuclides with low Kd values (3H, 90Sr, 137Cs) have already been transported to monitoring wells, as well as to the atolls' lagoons and the open ocean.

Speciation of uranium in surface-modified, hydrothermally treated, (UO{sub 2}){sup 2+}-exchanged smectite clays

DOE Office of Scientific and Technical Information (OSTI.GOV)

Giaquinta, D.M.; Soderholm, L.; Yuchs, S.E.

1997-08-01

A successful solution to the problem of disposal and permanent storage of water soluble radioactive species must address two issues: exclusion of the radionuclides from the environment and the prevention of leaching from the storage media into the environment. Immobilization of radionuclides in clay minerals has been studied. In addition to the use of clays as potential waste forms, information about the interactions of radionuclides with clays and how such interactions affect their speciations is crucial for successful modeling of actinide-migration. X-ray absorption spectroscopy (XAS) is used to determine the uranium speciation in exchanged and surface-modified clays. The XAS datamore » from uranyl-loaded bentonite clay are compared with those obtained after the particle surfaces have been coated with alkylsilanes. These silane films, which render the surface of the clay hydrophobic, are added in order to minimize the ability of external water to exchange with the water in the clay interlayer, thereby decreasing the release rate of the exchanged-uranium species. Mild hydrothermal conditions are used in an effort to mimic potential geologic conditions that may occur during long-term radioactive waste storage. The XAS spectra indicate that the uranyl monomer species remain unchanged in most samples, except in those samples that were both coated with an alkylsilane and hydrothermally treated. When the clay was coated with an organic film, formed by the acidic deposition of octadecyltrimethoxysilane, hydrothermal treatment results in the formation of aggregated uranium species in which the uranium is reduced from U{sup VI} to U{sup IV}.« less

Analysis of a nuclear accident: fission and activation product releases from the Fukushima Daiichi nuclear facility as remote indicators of source identification, extent of release, and state of damaged spent nuclear fuel.

PubMed

Schwantes, Jon M; Orton, Christopher R; Clark, Richard A

2012-08-21

Researchers evaluated radionuclide measurements of environmental samples taken from the Fukushima Daiichi nuclear facility and reported on the Tokyo Electric Power Co. Website following the 2011 tsunami-initiated catastrophe. This effort identified Units 1 and 3 as the major source of radioactive contamination to the surface soil near the facility. Radionuclide trends identified in the soils suggested that: (1) chemical volatility driven by temperature and reduction potential within the vented reactors' primary containment vessels dictated the extent of release of radiation; (2) all coolant had likely evaporated by the time of venting; and (3) physical migration through the fuel matrix and across the cladding wall were minimally effective at containing volatile species, suggesting damage to fuel bundles was extensive. Plutonium isotopic ratios and their distance from the source indicated that the damaged reactors were the major contributor of plutonium to surface soil at the source, decreasing rapidly with distance from the facility. Two independent evaluations estimated the fraction of the total plutonium inventory released to the environment relative to cesium from venting Units 1 and 3 to be ∼0.002-0.004%. This study suggests significant volatile radionuclides within the spent fuel at the time of venting, but not as yet observed and reported within environmental samples, as potential analytes of concern for future environmental surveys around the site. The majority of the reactor inventories of isotopes of less volatile elements like Pu, Nb, and Sr were likely contained within the damaged reactors during venting.

Potential for microbial H2 and metal transformations associated with novel bacteria and archaea in deep terrestrial subsurface sediments.

PubMed

Hernsdorf, Alex W; Amano, Yuki; Miyakawa, Kazuya; Ise, Kotaro; Suzuki, Yohey; Anantharaman, Karthik; Probst, Alexander; Burstein, David; Thomas, Brian C; Banfield, Jillian F

2017-08-01

Geological sequestration in deep underground repositories is the prevailing proposed route for radioactive waste disposal. After the disposal of radioactive waste in the subsurface, H 2 may be produced by corrosion of steel and, ultimately, radionuclides will be exposed to the surrounding environment. To evaluate the potential for microbial activities to impact disposal systems, we explored the microbial community structure and metabolic functions of a sediment-hosted ecosystem at the Horonobe Underground Research Laboratory, Hokkaido, Japan. Overall, we found that the ecosystem hosted organisms from diverse lineages, including many from the phyla that lack isolated representatives. The majority of organisms can metabolize H 2 , often via oxidative [NiFe] hydrogenases or electron-bifurcating [FeFe] hydrogenases that enable ferredoxin-based pathways, including the ion motive Rnf complex. Many organisms implicated in H 2 metabolism are also predicted to catalyze carbon, nitrogen, iron and sulfur transformations. Notably, iron-based metabolism is predicted in a novel lineage of Actinobacteria and in a putative methane-oxidizing ANME-2d archaeon. We infer an ecological model that links microorganisms to sediment-derived resources and predict potential impacts of microbial activity on H 2 consumption and retardation of radionuclide migration.

Organic matter and containment of uranium and fissiogenic isotopes at the Oklo natural reactors

USGS Publications Warehouse

Nagy, B.; Gauthier-Lafaye, F.; Holliger, P.; Davis, D.W.; Mossman, D.J.; Leventhal, J.S.; Rigali, M.J.; Parnell, J.

1991-01-01

SOME of the Precambrian natural fission reactors at Oklo in Gabon contain abundant organic matter1,2, part of which was liquefied at the time of criticality and subsequently converted to a graphitic solid3,4. The liquid organic matter helps to reduce U(VI) to U(IV) from aqueous solutions, resulting in the precipitation of uraninite5. It is known that in the prevailing reactor environments, precipitated uraninite grains incorporated fission products. We report here observations which show that these uraninite crystals were held immobile within the resolidified, graphitic bitumen. Unlike water-soluble (humic) organic matter, the graphitic bituminous organics at Oklo thus enhanced radionu-clide containment. Uraninite encased in solid graphitic matter in the organic-rich reactor zones lost virtually no fissiogenic lan-thanide isotopes. The first major episode of uranium and lead migration was caused by the intrusion of a swarm of adjacent dolerite dykes about 1,100 Myr after the reactors went critical. Our results from Oklo imply that the use of organic, hydrophobic solids such as graphitic bitumen as a means of immobilizing radionuclides in pretreated nuclear waste warrants further investigation. ?? 1991 Nature Publishing Group.

An Enhanced Monitoring Network at the Central Nevada Test Area (CNTA) Work performed under U.S. Department of Energy Office of Legacy Management contract #DE-AM01-07LM00060

NASA Astrophysics Data System (ADS)

Hodges, R.; Findlay, R.; Kautsky, M.

2009-12-01

On January 19, 1968 the Atomic Energy Commission detonated a 200-1000 kt nuclear device at a depth of 975 meters at CNTA, approximately 100 miles north of the Nevada Test Site. Details of the detonation remain classified, including the specific yield and the size of the resultant cavity. Therefore, using the rough, generic relationships between yield and cavity size, yield and depth of burial, and cancelling out yield, leads to an estimated cavity radius of 100 meters for this detonation in the volcanic section. A collapse chimney subsequently formed that extended several hundred meters above the detonation into the overlying alluvium. The detonation reactivated several faults at the site and created a 2 km2 graben at the surface. The radionuclides in the detonation zone are a potential source of groundwater contamination. The most permeable unit near the detonation zone through which transport might occur is believed to be a densely welded tuff unit (DWT) below the detonation level. A three-well monitoring network was designed using a numerical model, and data were collected from the wells for comparison with model predictions. The head data from the wells were not in agreement with those predicted by the model, and the model was not validated. In a positive finding for radionuclide containment, aquifer test results from the new wells indicate that the DWT is less permeable than previously expected and suggest that the contaminant boundary developed from the model is likely conservative for predicting transport within the volcanic section. The overlying alluvial aquifer is not believed to be a migration pathway for significant quantities of radionuclides, though it is the most likely pathway to potential receptors in that it is the primary groundwater source in the area. To enhance the CNTA monitoring network, two new alluvial wells were installed in 2009, downgradient (east-southeast and south-southeast) of the detonation. The dual-completion alluvial wells were designed to not only monitor for radionuclides but also to determine if a southeast-bounding graben fault acts as a flow barrier. A seismic survey was conducted to optimally locate the wells with respect to the fault. The survey imaged the water table and showed offsets of the water table reflector at numerous faults; some of the faults were known and others had not been previously recognized. Water levels from the new alluvial wells and piezometers compare well with existing well data and support the conjecture that the southeast-bounding graben fault is a flow barrier. Over the last five years, a monitoring network at CNTA has been developed that monitors both the most likely migration pathway and the most likely pathway to potential receptors. The site investigation processes discussed here have also identified factors that affect groundwater flow at the site, and the methods employed can be used in similar hydrogeologic environments.

Model Evaluation Report for Corrective Action Unit 98: Frenchman Flat, Nevada National Security Site, Nye County, Nevada, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ruskauff, Greg; Marutzky, Sam

Model evaluation focused solely on the PIN STRIPE and MILK SHAKE underground nuclear tests’ contaminant boundaries (CBs) because they had the largest extent, uncertainty, and potential consequences. The CAMBRIC radionuclide migration experiment also had a relatively large CB, but because it was constrained by transport data (notably Well UE-5n), there was little uncertainty, and radioactive decay reduced concentrations before much migration could occur. Each evaluation target and the associated data-collection activity were assessed in turn to determine whether the new data support, or demonstrate conservatism of, the CB forecasts. The modeling team—in this case, the same team that developed themore » Frenchman Flat geologic, source term, and groundwater flow and transport models—analyzed the new data and presented the results to a PER committee. Existing site understanding and its representation in numerical groundwater flow and transport models was evaluated in light of the new data and the ability to proceed to the CR stage of long-term monitoring and institutional control.« less

Diffusion and Leaching Behavior of Radionuclides in Category 3 Waste Encasement Concrete and Soil Fill Material – Summary Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mattigod, Shas V.; Wellman, Dawn M.; Bovaird, Chase C.

2011-08-31

One of the methods being considered for safely disposing of Category 3 low-level radioactive wastes is to encase the waste in concrete. Such concrete encasement would contain and isolate the waste packages from the hydrologic environment and would act as an intrusion barrier. The current plan for waste isolation consists of stacking low-level waste packages on a trench floor, surrounding the stacks with reinforced steel, and encasing these packages in concrete. These concrete-encased waste stacks are expected to vary in size with maximum dimensions of 6.4 m long, 2.7 m wide, and 4 m high. The waste stacks are expectedmore » to have a surrounding minimum thickness of 15 cm of concrete encasement. These concrete-encased waste packages are expected to withstand environmental exposure (solar radiation, temperature variations, and precipitation) until an interim soil cover or permanent closure cover is installed, and to remain largely intact thereafter. Any failure of concrete encasement may result in water intrusion and consequent mobilization of radionuclides from the waste packages. The mobilized radionuclides may escape from the encased concrete by mass flow and/or diffusion and move into the surrounding subsurface environment. Therefore, it is necessary to assess the performance of the concrete encasement structure and the ability of the surrounding soil to retard radionuclide migration. The retardation factors for radionuclides contained in the waste packages can be determined from measurements of diffusion coefficients for these contaminants through concrete and fill material. Some of the mobilization scenarios include (1) potential leaching of waste form before permanent closure cover is installed; (2) after the cover installation, long-term diffusion of radionuclides from concrete waste form into surrounding fill material; (3) diffusion of radionuclides from contaminated soils into adjoining concrete encasement and clean fill material. Additionally, the rate of diffusion of radionuclides may be affected by the formation of structural cracks in concrete, the carbonation of the buried waste form, and any potential effect of metallic iron (in the form of rebars) on the mobility of radionuclides. The radionuclides iodine-129 ({sup 129}I), technetium-99 ({sup 99}Tc), and uranium-238 ({sup 238}U) are identified as long-term dose contributors in Category 3 waste (Mann et al. 2001; Wood et al. 1995). Because of their anionic nature in aqueous solutions, {sup 129}I, {sup 99}Tc, and carbonate-complexed {sup 238}U may readily leach into the subsurface environment (Serne et al. 1989, 1992a, b, 1993, and 1995). The leachability and/or diffusion of radionuclide species must be measured to assess the long-term performance of waste grouts when contacted with vadose-zone pore water or groundwater. Although significant research has been conducted on the design and performance of cementitious waste forms, the current protocol conducted to assess radionuclide stability within these waste forms has been limited to the Toxicity Characteristic Leaching Procedure, Method 1311 Federal Registry (EPA 1992) and ANSI/ANS-16.1 leach test (ANSI 1986). These tests evaluate the performance under water-saturated conditions and do not evaluate the performance of cementitious waste forms within the context of waste repositories which are located within water-deficient vadose zones. Moreover, these tests assess only the diffusion of radionuclides from concrete waste forms and neglect evaluating the mechanisms of retention, stability of the waste form, and formation of secondary phases during weathering, which may serve as long-term secondary hosts for immobilization of radionuclides. The results of recent investigations conducted under arid and semi-arid conditions (Al-Khayat et al. 2002; Garrabrants et al. 2002; Garrabrants and Kosson 2003; Garrabrants et al. 2004; Gervais et al. 2004; Sanchez et al. 2002; Sanchez et al. 2003) provide valuable information suggesting structural and chemical changes to concrete waste forms which may affect contaminant containment and waste form performance. However, continued research is necessitated by the need to understand: the mechanism of contaminant release; the significance of contaminant release pathways; how waste form performance is affected by the full range of environmental conditions within the disposal facility; the process of waste form aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of waste form aging on chemical, physical, and radiological properties, and the associated impact on contaminant release. Recent reviews conducted by the National Academies of Science recognized the efficacy of cementitious materials for waste isolation, but further noted the significant shortcomings in our current understanding and testing protocol for evaluating the performance of various formulations.« less

Flood and Fire Monitoring and Forecasting Within the Chornobyl Exclusion Zone

NASA Astrophysics Data System (ADS)

Los, Victor

2001-03-01

Taking into consideration that radioactivity from the contaminating elements of the Chernobyl Exclusion Zone (CEZ) amounts to a huge number, one of the most urgent tasks, at present, is the resolution of problems related to secondary radioactive contamination caused by floods and fires. These factors may lead to critical consequences. For instance, if radioactive contaminants migrate into the water system, namely into the Dnipro River, a threat arises to more than 20 million inhabitants of Ukraine. Additionally, fires in the CEZ potentially could cause contaminants to be dispersed into the air and to migrate in the atmosphere for long distances. The elements of information support system for administrative decision-making to respond to the appearances and consequences of forest fires and floods in contaminated areas of the CEZ have been developed. The system proposes: using Earth Remote Sensing (R/S) data for timely detection of forest fires; integration by Geographic Information System (GIS) of mathematical models for radionuclide migration by air in order to forecast radiological consequences of forest fires; forecasting and assessing flood consequences by means of spatial analysis of GIS and R/S; and development of a system for dissemination of information. This project was performed within the framework of USAID Cooperative Agreement #121-A-00-98-00615-00, dedicated to the establishment of the Ukrainian Land and Resource Management Center.

Estimation of Cs-137 hillslope patterns of Polesje landscapes using geo-information modeling techniques (on example of the Bryansk region)

NASA Astrophysics Data System (ADS)

Linnik, Vitaly; Nenko, Kristina; Sokolov, Alexander; Saveliev, Anatoly

2015-04-01

In the result of Chernobyl disaster on 26 April 1986 many regions of Ukraine, Belarus and Russia were contaminated by radionuclides. Vast areas of farmlands and woodlands were contaminated in Russia. The deposited radionuclides continue to cause concern about the possible contamination of food (in particular, mushrooms and berries). But the radioactive materials are also an ideal marker for understanding of hillslope processes in natural and seminatural landscapes. Model area chosen for the research (Opolje landscapes located in the central part of the Bryansk region) is characterized by relatively low levels of Cs-137 contamination. It just 4-33 times higher than global fallout which was equal 1,75 kBq/m2 in 1986 . According the results of air gamma survey (grid size: 100 m x100 m), which was done in 1993, it was explicitly to identify that the processes of Cs-137 lateral migration took place due to nearly fourfold increase of Cs-137 in the lower slope in comparison with the surface of the watershed during a seven-year period after Chernobyl accident. Erosion processes which define Cs-137 pattern in the lowest part of hillslope depend upon such parameters as slope, hillslope forms, vegetation, land use and the roads, which intersect a streamline. GIS-modeling of Cs-137 was carried out in SAGA software. The spatial modeling resolution was equal 100x100 m according the air-gamma data. SRTM data was resampled to a grid 100x100 m. Erosion rates were the highest on the slope of southern exposure. There the processes of lateral migration are more intensive and observed within the entire slope. The main contribution in receipt of Cs-137 to floodplain on the northern slopes comes only from the lower part of the slope and gullies and ravines network. We have used geo-information modeling techniques and some kind of interpolation and statistical models to predict or understand forming of Cs-137 spatial patterns and trends in soil erosion. To study the role of some geomorphological parameters in the Cs-137 redistribution we apply different mathematical models. We have identified the main trend (dependence on the X, Y coordinate) and contribution of such geomorphological parameters as concave and convex profiles, slope and others. Thus, the use of fallout radionuclides, measured with air-gamma survey, can complement our concept about Cs-137 secondary redistribution due the erosion processes which controlled by numerous of landscape factors.

The latest results on colloid associated radionuclide migration from the CFM Project, Grimsel Test Site (GTS, Switzerland)

NASA Astrophysics Data System (ADS)

Schaefer, T.; Blechschmidt, I.; Bouby, M.; Buechner, S.; Brendlé, J.; Geckeis, H.; Kupcik, T.; Goetz, R.; Hauser, W.; Heck, S.; Huber, F. M.; Lagos, M.; Martin, A. J.

2013-12-01

The influence of colloidal/nano-scale phases on the radionuclide (RNs) solubility and migration behavior is still one of the uncertainties in repository safety assessment [1]. Within the Colloid Formation and Migration (CFM) project at the Grimsel Test Site (GTS Switzerland) a huge geo-technical effort was taken to isolate hydraulically a shear-zone from the artificially introduced hydraulic gradient due to the tunnel construction. The construction is a combination of polymer resin impregnation of the tunnel surface and a steel torus to seal the tunnel surface. Natural outflow points of the MI shear zone were localized prior to the construction and sealed by surface packers. This design gives the opportunity to adjust the flow velocity in the fracture. After optimization of the experimental setup and injection procedure through a number of conservative tracer tests a license was granted in January 2012 by the Swiss regulator (BAG) to perform the first radionuclide tracer test under these low-flow conditions. The injection cocktail of 2.25L volume consisted of 101.4 × 2.5 mg/L montmorillonite clay colloids, whereas 8.9 × 0.4mg/L were present as synthetic montmorillonite with structural incorporated Ni. For details on the structural characterization of the Ni-montmorillonite phyllosilicate, see [2]. Beside the colloids and the conservative tracer Amino-G (1646 × 8ppb) the radioisotopes Na-22, Ba-133, Cs-137, Th-232, Np-237, Pu-242 and Am-243 were injected. The trivalent and tetravalent actinides were quantitatively associated with the colloids present as well as a part of the Cs, whereas Np(V) and Na are not bentonite colloid bond. For on-site colloid analysis a mobile Laser- Induced Breakdown Detection (LIBD) system similar to the one used in the CRR experiments [3] was transferred to Grimsel and installed in-line at the 'Pinkel' outlet to directly monitor the mobile colloid fraction throughout the experiment. The conservative tracer Amino-G was recovered quantitatively and for the weakly sorbing tracers analyzed by γ-spectrometry recoveries for Na-22, Cs-137 and Ba-133 of 64%, 10% and 1%, respectively, were found. The clay colloid recovery determined by LIBD and HR-ICP-MS analyzing Al and Ni as structural components of the clay particles provided 48-52%. For the initial quantitatively colloid associated actinides Am(III) and Pu(IV) a recovery of 21-22% and 30-35%, respectively, could be determined. Np recovery is significantly reduced to ~4 %, which hints to a kinetic controlled Np(V) reduction. The data obtained so far clearly show the mobility of bentonite derived montmorillonite colloids under near-natural flow conditions in the MI shear zone of the Grimsel Test Site [4]. The experimental data will be discussed in detail in the presentation. [1] T. Schäfer, et al. Appl. Geochem., 27 (2012) 390-403. [2] Reinholdt, et al., Nanomaterials, 3 (2013) 48-69. [3] H. Geckeis, et al., Radiochim. Acta, 92 (2004) 765-774. [4] www.grimsel.com

Water-Chemistry Evolution and Modeling of Radionuclide Sorption and Cation Exchange during Inundation of Frenchman Flat Playa

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hershey, Ronald; Cablk, Mary; LeFebre, Karen

2013-08-01

Atmospheric tests and other experiments with nuclear materials were conducted on the Frenchman Flat playa at the Nevada National Security Site, Nye County, Nevada; residual radionuclides are known to exist in Frenchman Flat playa soils. Although the playa is typically dry, extended periods of winter precipitation or large single-event rainstorms can inundate the playa. When Frenchman Flat playa is inundated, residual radionuclides on the typically dry playa surface may become submerged, allowing water-soil interactions that could provide a mechanism for transport of radionuclides away from known areas of contamination. The potential for radionuclide transport by occasional inundation of the Frenchmanmore » Flat playa was examined using geographic information systems and satellite imagery to delineate the timing and areal extent of inundation; collecting water samples during inundation and analyzing them for chemical and isotopic content; characterizing suspended/precipitated materials and archived soil samples; modeling water-soil geochemical reactions; and modeling the mobility of select radionuclides under aqueous conditions. The physical transport of radionuclides by water was not evaluated in this study. Frenchman Flat playa was inundated with precipitation during two consecutive winters in 2009-2010 and 2010-2011. Inundation allowed for collection of multiple water samples through time as the areal extent of inundation changed and ultimately receded. During these two winters, precipitation records from a weather station in Frenchman Flat (Well 5b) provided information that was used in combination with geographic information systems, Landsat imagery, and image processing techniques to identify and quantify the areal extent of inundation. After inundation, water on the playa disappeared quickly, for example, between January 25, 2011 and February 10, 2011, a period of 16 days, 92 percent of the areal extent of inundation receded (2,062,800 m2). Water sampling provided valuable information about chemical processes occurring during inundation as the water disappeared. Important observations from water-chemistry analyses included: 1) total dissolved solids (TDS) and chloride ion (Cl-) concentrations were very low (TDS: < 200 mg/L and Cl-: < 3.0 mg/L, respectively) for all water samples regardless of time or areal extent; 2) all dissolved constituents were at concentrations well below what might be expected for evaporating shallow surface waters on a playa, even when 98 to 99 percent of the water had disappeared; 3) the amount of evaporation for the last water samples collected at the end of inundation, estimated with the stable isotopic ratios δ2H or δ18O, was approximately 60 percent; and 4) water samples analyzed by gamma spectroscopy did not show any man-made radioactivity; however, the short scanning time (24 hours) and relative chemical diluteness of the water samples (TDS ranged between 39 and 190 mg/L) may have contributed to none being detected. Additionally, any low-energy beta emitting radionuclides would not have been detected by gamma spectroscopy. From these observations, it was apparent that a significant portion of water on the playa did not evaporate, but rather infiltrated into the subsurface (approximately 40 percent). Consistent with this water chemistry-based conclusion is particle-size analysis of two archived Frenchman Flat playa soils samples, which showed low clay content in the near surface soil that also suggested infiltration. Infiltration of water from the playa during inundation into the subsurface does not necessarily imply that groundwater recharge is occurring, but it does provide a mechanism for moving residual radionuclides downward into the subsurface of Frenchman Flat playa. Water-mineral geochemical reactions were modeled so that changes in the water chemistry could be identified and the extent of reactions quantified. Geochemical modeling showed that evaporation; equilibrium with atmospheric carbon dioxide and calcite; dissolution of sodium chloride, gypsum, and composite volcanic glass; and precipitation of composite clay and quartz represented changes in water as it disappeared from the playa. This modeling provided an understanding of the water-soil geochemical environment, which was then used to evaluate the potential mobility of residual radionuclides into the playa soils by water. Because there is no information on the chemical forms of anthropogenic radionuclides in Frenchman Flat playa soil, it was assumed that soil radionuclides go into solution when the playa is inundated. In mobility modeling, a select group of radionuclides were allowed to sorb onto, or exchange with, playa soil minerals to evaluate the likelihood that the radionuclides would be removed from water during playa inundation. Radionuclide mobility modeling suggested that there would be minimal sorption or exchange of several important radionuclides (uranium, cesium, and technetium) with playa minerals such that they may be mobile in water when the playa is inundated and could infiltrate into the subsurface. Mobility modeling also showed that plutonium may be much less mobile because of sorption onto calcite, but the amount of reactive surface area of playa soil calcite is highly uncertain. Plutonium is also known to sorb onto colloidal particles suspended in water, suspended colloidal particles will move with the water, providing a mechanism to redistribute plutonium when Frenchman Flat playa is inundated. Water chemistry, stable isotopes, and geochemical modeling showed that residual radionuclides in Frenchman Flat playa soils could be mobilized in water when the playa is inundated with precipitation. Also, there is potential for these radionuclides to infiltrate into the subsurface with water. As a result of the information obtained both during this study and the conclusions drawn from it, additional data collection, investigation, and modeling are recommended. Specifically: sampling the playa soil to search for evidence of surface-water infiltration and the presence of radionuclides; developing a preliminary unsaturated flow and transport model to guide soil sampling; characterizing the chemical forms of radionuclides on the playa surface and any radionuclides that might have migrated into the subsurface; and, refining the unsaturated flow and transport model with data obtained from sampling and analysis of soil samples to guide any future sampling, development of remediation strategies, and defining risk-based boundaries for Frenchman Flat playa.« less

Soil prokaryotic communities in Chernobyl waste disposal trench T22 are modulated by organic matter and radionuclide contamination.

PubMed

Theodorakopoulos, Nicolas; Février, Laureline; Barakat, Mohamed; Ortet, Philippe; Christen, Richard; Piette, Laurie; Levchuk, Sviatoslav; Beaugelin-Seiller, Karine; Sergeant, Claire; Berthomieu, Catherine; Chapon, Virginie

2017-08-01

After the Chernobyl nuclear power plant accident in 1986, contaminated soils, vegetation from the Red Forest and other radioactive debris were buried within trenches. In this area, trench T22 has long been a pilot site for the study of radionuclide migration in soil. Here, we used 454 pyrosequencing of 16S rRNA genes to obtain a comprehensive view of the bacterial and archaeal diversity in soils collected inside and in the vicinity of the trench T22 and to investigate the impact of radioactive waste disposal on prokaryotic communities. A remarkably high abundance of Chloroflexi and AD3 was detected in all soil samples from this area. Our statistical analysis revealed profound changes in community composition at the phylum and OTUs levels and higher diversity in the trench soils as compared to the outside. Our results demonstrate that the total absorbed dose rate by cell and, to a lesser extent the organic matter content of the trench, are the principal variables influencing prokaryotic assemblages. We identified specific phylotypes affiliated to the phyla Crenarchaeota, Acidobacteria, AD3, Chloroflexi, Proteobacteria, Verrucomicrobia and WPS-2, which were unique for the trench soils. © FEMS 2017. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Potential for microbial H2 and metal transformations associated with novel bacteria and archaea in deep terrestrial subsurface sediments

PubMed Central

Hernsdorf, Alex W; Amano, Yuki; Miyakawa, Kazuya; Ise, Kotaro; Suzuki, Yohey; Anantharaman, Karthik; Probst, Alexander; Burstein, David; Thomas, Brian C; Banfield, Jillian F

2017-01-01

Geological sequestration in deep underground repositories is the prevailing proposed route for radioactive waste disposal. After the disposal of radioactive waste in the subsurface, H2 may be produced by corrosion of steel and, ultimately, radionuclides will be exposed to the surrounding environment. To evaluate the potential for microbial activities to impact disposal systems, we explored the microbial community structure and metabolic functions of a sediment-hosted ecosystem at the Horonobe Underground Research Laboratory, Hokkaido, Japan. Overall, we found that the ecosystem hosted organisms from diverse lineages, including many from the phyla that lack isolated representatives. The majority of organisms can metabolize H2, often via oxidative [NiFe] hydrogenases or electron-bifurcating [FeFe] hydrogenases that enable ferredoxin-based pathways, including the ion motive Rnf complex. Many organisms implicated in H2 metabolism are also predicted to catalyze carbon, nitrogen, iron and sulfur transformations. Notably, iron-based metabolism is predicted in a novel lineage of Actinobacteria and in a putative methane-oxidizing ANME-2d archaeon. We infer an ecological model that links microorganisms to sediment-derived resources and predict potential impacts of microbial activity on H2 consumption and retardation of radionuclide migration. PMID:28350393

External beam radiation therapy enhances mesenchymal stem cell-mediated sodium iodide symporter gene delivery.

PubMed

Schug, Christina; Sievert, Wolfgang; Urnauer, Sarah; Müller, Andrea Maria; Schmohl, Kathrin Alexandra; Wechselberger, Alexandra; Schwenk, Nathalie; Lauber, Kirsten; Schwaiger, Markus; Multhoff, Gabriele; Wagner, Ernst; Nelson, Peter J; Spitzweg, Christine

2018-05-04

The tumor-homing properties of mesenchymal stem cells (MSC) have led to their development as delivery vehicles for the targeted delivery of therapeutic genes such as the sodium iodide symporter (NIS) to solid tumors. External beam radiation therapy (EBRT) may represent an ideal setting for the application of engineered MSC-based gene therapy as tumor irradiation may enhance MSC recruitment into irradiated tumors through the increased production of select factors linked to MSC migration. In the present study, the irradiation of human liver cancer cells (HuH7) (1-10 Gy) showed a strong dose-dependent increase in steady state mRNA levels of CXCL8, CXCL12/SDF-1, FGF2, PDGFβ, TGFβ1, TSP-1 and VEGF (0-48 h), which was verified for most factors at the protein level (after 48 h). Radiation effects on directed MSC migration was tested in vitro using a live cell tracking migration assay and supernatants from control and irradiated HuH7 cells. A robust increase in mean forward migration index (yFMI), mean center of mass (yCoM) and mean directionality of MSCs towards supernatants was seen from irradiated as compared to nonirradiated tumor cells. Transferability of this effect to other tumor sources was demonstrated using the human breast adenocarcinoma cell line (MDA-MB-231), which showed a similar behavior to radiation as seen with HuH7 cells in qPCR and migration assay. To evaluate this in a more physiologic in vivo setting, subcutaneously growing HuH7 xenograft tumors were irradiated with 0, 2 or 5 Gy followed by CMV-NIS-MSC application 24 h later. Tumoral iodide uptake was monitored using ¹²³I-scintigraphy. The results showed increased tumor-specific dose-dependent accumulation of radioiodide in irradiated tumors. Our results demonstrate that EBRT enhances the migratory capacity of MSCs and may thus increase the therapeutic efficacy of MSC-mediated NIS radionuclide therapy.

CEM V based special cementitious materials investigated by means of SANS method. Preliminary results

NASA Astrophysics Data System (ADS)

Dragolici, A. C.; Balasoiu, M.; Orelovich, O. L.; Ionascu, L.; Nicu, M.; Soloviov, D. V.; Kuklin, A. I.; Lizunov, E. I.; Dragolici, F.

2017-05-01

The management of the radioactive waste assume the conditioning in a cement matrix as an embedding, stable, disposal material. Cement matrix is the first and most important engineering barrier against the migration in the environment of the radionuclides contained in the waste packages. Knowing how the microstructure develops is therefore desirable in order to assess the compatibility of radioactive streams with cement and predict waste form performance during storage and disposal. For conditioning wastes containing radioactive aluminum new formulas of low basicity cements, using coatings as a barrier between the metal and the conditioning environment or introducing a corrosion inhibitor in the matrix system are required. Preliminary microstructure investigation of such improved CEM V based cement matrix is reported.

Delayed signatures of underground nuclear explosions

PubMed Central

Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

2016-01-01

Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates. PMID:26979288

Delayed signatures of underground nuclear explosions

NASA Astrophysics Data System (ADS)

Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; Ruddle, David G.; Wagoner, Jeffrey L.; Myers, Katherine B. L.; Emer, Dudley F.; Drellack, Sigmund L.; Chipman, Veraun D.

2016-03-01

Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.

Delayed signatures of underground nuclear explosions.

PubMed

Carrigan, Charles R; Sun, Yunwei; Hunter, Steven L; Ruddle, David G; Wagoner, Jeffrey L; Myers, Katherine B L; Emer, Dudley F; Drellack, Sigmund L; Chipman, Veraun D

2016-03-16

Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. We observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be an indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People's Republic of Korea (DPRK). Our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.

Methods of separating short half-life radionuclides from a mixture of radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Bray, L.A.; Ryan, J.L.

1998-09-15

The present invention is a method of obtaining a radionuclide product selected from the group consisting of {sup 223}Ra and {sup 225}Ac, from a radionuclide ``cow`` of {sup 227}Ac or {sup 229}Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ``cow`` forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ``cow`` from at least one radionuclide daughter; (d) insuring that the at leastmore » one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ``cow``. In one embodiment the radionuclide ``cow`` is the {sup 227}Ac, the at least one daughter radionuclide is a {sup 227}Th and the product radionuclide is the {sup 223}Ra and the first nitrate form ion exchange column passes the {sup 227}Ac and retains the {sup 227}Th. In another embodiment the radionuclide ``cow`` is the {sup 229}Th, the at least one daughter radionuclide is a {sup 225}Ra and said product radionuclide is the {sup 225}Ac and the {sup 225}Ac and nitrate form ion exchange column retains the {sup 229}Th and passes the {sup 225}Ra/Ac. 8 figs.« less

Methods of separating short half-life radionuclides from a mixture of radionuclides

DOEpatents

Bray, Lane A.; Ryan, Jack L.

1998-01-01

The present invention is a method of obtaining a radionuclide product selected from the group consisting of .sup.223 Ra and .sup.225 Ac, from a radionuclide "cow" of .sup.227 Ac or .sup.229 Th respectively. The method comprises the steps of a) permitting ingrowth of at least one radionuclide daughter from said radionuclide "cow" forming an ingrown mixture; b) insuring that the ingrown mixture is a nitric acid ingrown mixture; c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the "cow" from at least one radionuclide daughter; d) insuring that the at least one radionuclide daughter contains the radionuclide product; e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and f) recycling the at least one radionuclide daughter by adding it to the "cow". In one embodiment the radionuclide "cow" is the .sup.227 Ac, the at least one daughter radionuclide is a .sup.227 Th and the product radionuclide is the .sup.223 Ra and the first nitrate form ion exchange column passes the .sup.227 Ac and retains the .sup.227 Th. In another embodiment the radionuclide "cow"is the .sup.229 Th, the at least one daughter radionuclide is a .sup.225 Ra and said product radionuclide is the .sup.225 Ac and the .sup.225 Ac and nitrate form ion exchange column retains the .sup.229 Th and passes the .sup.225 Ra/Ac.

Methods of separating short half-life radionuclides from a mixture of radionuclides

DOEpatents

Bray, L.A.; Ryan, J.L.

1998-09-15

The present invention is a method of obtaining a radionuclide product selected from the group consisting of {sup 223}Ra and {sup 225}Ac, from a radionuclide ``cow`` of {sup 227}Ac or {sup 229}Th respectively. The method comprises the steps of (a) permitting ingrowth of at least one radionuclide daughter from said radionuclide ``cow`` forming an ingrown mixture; (b) insuring that the ingrown mixture is a nitric acid ingrown mixture; (c) passing the nitric acid ingrown mixture through a first nitrate form ion exchange column which permits separating the ``cow`` from at least one radionuclide daughter; (d) insuring that the at least one radionuclide daughter contains the radionuclide product; (e) passing the at least one radionuclide daughter through a second ion exchange column and separating the at least one radionuclide daughter from the radionuclide product and (f) recycling the at least one radionuclide daughter by adding it to the ``cow``. In one embodiment the radionuclide ``cow`` is the {sup 227}Ac, the at least one daughter radionuclide is a {sup 227}Th and the product radionuclide is the {sup 223}Ra and the first nitrate form ion exchange column passes the {sup 227}Ac and retains the {sup 227}Th. In another embodiment the radionuclide ``cow`` is the {sup 229}Th, the at least one daughter radionuclide is a {sup 225}Ra and said product radionuclide is the {sup 225}Ac and the {sup 225}Ac and nitrate form ion exchange column retains the {sup 229}Th and passes the {sup 225}Ra/Ac. 8 figs.

Radionuclide Therapy

NASA Astrophysics Data System (ADS)

Zalutsky, M. R.

Radionuclide therapy utilizes unsealed sources of radionuclides as a treatment for cancer or other pathological conditions such as rheumatoid arthritis. Radionuclides that decay by the emission of β and α particles, as well as those that emit Auger electrons, have been used for this purpose. In this chapter, radiochemical aspects of radionuclide therapy, including criteria for radionuclide selection, radionuclide production, radiolabeling chemistry, and radiation dosimetry are discussed.

Method and apparatus for separating radionuclides from non-radionuclides

DOEpatents

Harp, Richard J.

1990-01-01

In an apparatus for separating radionuclides from non-radionuclides in a mixture of nuclear waste, a vessel is provided wherein the mixture is heated to a temperature greater than the temperature of vaporization for the non-radionuclides but less than the temperature of vaporization for the radionuclides. Consequently the non-radionuclides are vaporized while the non-radionuclides remain the solid or liquid state. The non-radionuclide vapors are withdrawn from the vessel and condensed to produce a flow of condensate. When this flow decreases the heat is reduced to prevent temperature spikes which might otherwise vaporize the radionuclides. The vessel is removed and capped with the radioactive components of the apparatus and multiple batches of the radionuclide residue disposed therein. Thus the vessel ultimately provides a burial vehicle for all of the radioactive components of the process.

Performance-assessment progress for the Rozan low-level waste disposal facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smietanski, L.; Mitrega, J.; Frankowski, Z.

1995-12-31

The paper presents a condensed progress report on the performance assessment of Poland`s low-level waste disposal facility which is operating since 1961. The Rozan repository is of near-surface type with facilities which are the concrete fortifications built about 1910. Site characterization activities supplied information on regional geology, geohydrology, climatic and hydrologic conditions and terrain surface evolution due to geodynamic processes. Field surveys enabled to decode lithological, hydrogeological and geochemical site specific conditions. From the laboratory tests the data on groundwater chemistry and soil geochemical and hydraulic characteristics were obtained. The site geohydrologic main vulnerable element is the upmost directly endangeredmore » unconfined aquifer which is perched in relation to the region-wide hydraulic system. Heterogeneity of this system reflects in a wide range of hydraulic conductivity and thickness variations. It strongly affects velocity and flow directions. The chemistry of groundwater is unstable due to large sensitivity to external impacts. Modeling of the migration of the critical long-lived radionuclides Tc-99, U-238 and Pu-239 showed that the nearly 20 m thick unsaturated zone plays crucial role as an effective protective barrier. These radionuclides constitute minor part of the total inventory. Modeling of the development of the H-3 plume pointed out the role the macrodispersion plays in the unsaturated zone beneath the repository.« less

Mobile fission and activation products in nuclear waste disposal

NASA Astrophysics Data System (ADS)

Grambow, Bernd

2008-12-01

When disposing nuclear waste in clay formations it is expected that the most radiotoxic elements like Pu, Np or Am move only a few centimetres to meters before they decay. Only a few radionuclides are able to reach the biosphere and contribute to their long-term exposure risks, mainly anionic species like I129, Cl36, Se79 and in some cases C14 and Tc99, whatever the scenario considered. The recent OECD/NEA cosponsored international MOFAP workshop focussed on transport and chemical behaviour of these less toxic radionuclides. New research themes have been addressed, such as how to make use of molecular level information for the understanding of the problem of migration at large distances. Diffusion studies need to face mineralogical heterogeneities over tens to hundreds of meters. Diffusion rates are very low since the clay rock pores are so small (few nm) that electrostatic repulsion limits the space available for anion diffusion (anion exclusion). The large volume of traversed rock will provide so many retention sites that despite weak retention, even certain of these "mobile" nuclides may show significant retardation. However, the question how to measure reliably very low retention parameters has been posed. An important issue is whether redox states or organic/inorganic speciation change from their initial state at the moment of release from the waste during long term contact with surfaces, hydrogen saturated environments, etc.

Mobile fission and activation products in nuclear waste disposal.

PubMed

Grambow, Bernd

2008-12-12

When disposing nuclear waste in clay formations it is expected that the most radiotoxic elements like Pu, Np or Am move only a few centimetres to meters before they decay. Only a few radionuclides are able to reach the biosphere and contribute to their long-term exposure risks, mainly anionic species like I129, Cl36, Se79 and in some cases C14 and Tc99, whatever the scenario considered. The recent OECD/NEA cosponsored international MOFAP workshop focussed on transport and chemical behaviour of these less toxic radionuclides. New research themes have been addressed, such as how to make use of molecular level information for the understanding of the problem of migration at large distances. Diffusion studies need to face mineralogical heterogeneities over tens to hundreds of meters. Diffusion rates are very low since the clay rock pores are so small (few nm) that electrostatic repulsion limits the space available for anion diffusion (anion exclusion). The large volume of traversed rock will provide so many retention sites that despite weak retention, even certain of these "mobile" nuclides may show significant retardation. However, the question how to measure reliably very low retention parameters has been posed. An important issue is whether redox states or organic/inorganic speciation change from their initial state at the moment of release from the waste during long term contact with surfaces, hydrogen saturated environments, etc.

Analysis of trace neptunium in the vicinity of underground nuclear tests at the Nevada National Security Site

DOE PAGES

Zhao, P.; Tinnacher, R. M.; Zavarin, M.; ...

2014-11-01

A high sensitivity analytical method for 237Np analysis was developed and applied to groundwater samples from the Nevada National Security Site (NNSS) using short-lived 239Np as a yield tracer and HR magnetic sector ICP-MS. The 237Np concentrations in the vicinity of the Almendro, Cambric, Dalhart, Cheshire, and Chancellor underground nuclear test locations range from <4 × 10 -4 to 2.6 mBq/L (6 × 10 -17–4.2 × 10 -13 mol/L). All measured 237Np concentrations are well below the drinking water maximum contaminant level for alpha emitters identified by the U.S. EPA (560 mBq/L). Nevertheless, 237Np remains an important indicator for radionuclidemore » transport rates at the NNSS. Retardation factor ratios were used to compare the mobility of 237Np to that of other radionuclides. The results suggest that 237Np is less mobile than tritium and other non-sorbing radionuclides ( 14C, 36Cl, 99Tc and 129I) as expected. Surprisingly, 237Np and plutonium ( 239,240Pu) retardation factors are very similar. It is possible that Np(IV) exists under mildly reducing groundwater conditions and exhibits a retardation behavior that is comparable to Pu(IV). Independent of the underlying process, 237Np is migrating downgradient from NNSS underground nuclear tests at very low but measureable concentrations.« less

Contamination of terrestrial ecosystem components with 90Sr, 137Cs, and 226Ra caused by the deterioration of the multibarrier protection of radioactive waste storages

NASA Astrophysics Data System (ADS)

Latynova, N. E.

2010-03-01

The spatial-temporal features of the radioactive contamination of terrestrial ecosystem components caused by the deterioration of the multibarrier protection of regional radioactive waste storages of the State Research Center of the Russian Federation-Leipunskii Institute of Physics and Power Engineering at the input of radionuclides into the soil and ground water were studied. The composition of the radioactive contamination was determined, and the hydrological and geochemical processes resulting in the formation of large radioactive sources were described. The natural features of the radioactive waste storage areas favoring the entry of 90Sr, 137Cs, and 226Ra into the soils and their inclusion in the biological turnover were characterized. The directions of the horizontal migration of 90Sr, 137Cs, and 226Ra and the sites of their accumulation within the superaquatic and aquatic landscapes of a near-terrace depression were studied; the factors of the 90Sr accumulation in plants and cockles were calculated. The results of the studies expand the theoretical concepts of the mechanisms, processes, and factors controlling the behavior of radionuclides at the deterioration of the multibarrier protection of radioactive waste storages. The presented experimental data can be used for solving practical problems related to environmental protection in the areas of industrial nuclear complexes.

Advanced Polymer Technology for Containing and Immobilizing Strontium-90 in the Subsurface - 8361

DOE Office of Scientific and Technical Information (OSTI.GOV)

K. Baker; G. Heath; C. Scott

2008-02-01

Many Department of Energy (DOE) sites, including Idaho and Hanford, have heavy metals and/or radionuclides (e.g. strontium-90) present that are strongly adsorbed in the vadose zone, but which nevertheless are propagating toward the water table. A key challenge for immobilization of these contaminants is bringing the chosen amendment or remediation technology into contact with the contaminated porous medium, while ensuring that contaminated water and colloids do not escape. This is particularly challenging when the subsurface geology is complex and highly heterogeneous, as is the case at many DOE sites. The Idaho National Laboratory (INL) in collaboration with the University ofmore » Texas at Austin (UT) has conducted research sponsored through the DOE Office of Environmental Management (EM) Advanced Remediation Technologies Phase I program that successfully demonstrated application of a novel, pH-triggered advanced polymer for creating a physical barrier that prevents heavy metals and radionuclides in vadose zone soil and soil-pore water from migrating to the groundwater. The focus of this paper is on the column and sandbox experiments conducted by researchers at the Idaho National Laboratory in support of the Phase I program objectives. Proof of these concepts provides a technology basis for confining or isolating a volume of contaminated groundwater, to be implemented in future investigations at the Vadose Zone Research Park (VZRP) at INL.« less

Effect of organic complexing agents on the interactions of Cs(+), Sr(2+) and UO(2)(2+) with silica and natural sand.

PubMed

Reinoso-Maset, Estela; Worsfold, Paul J; Keith-Roach, Miranda J

2013-05-01

Sorption processes play a key role in controlling radionuclide migration through subsurface environments and can be affected by the presence of anthropogenic organic complexing agents found at contaminated sites. The effect of these complexing agents on radionuclide-solid phase interactions is not well known. Therefore the aim of this study was to examine the processes by which EDTA, NTA and picolinate affect the sorption kinetics and equilibria of Cs(+), Sr(2+) and UO2(2+) onto natural sand. The caesium sorption rate and equilibrium were unaffected by the complexing agents. Strontium however showed greater interaction with EDTA and NTA in the presence of desorbed matrix cations than geochemical modelling predicted, with SrNTA(-) enhancing sorption and SrEDTA(2-) showing lower sorption than Sr(2+). Complexing agents reduced UO2(2+) sorption to silica and enhanced the sorption rate in the natural sand system. Elevated concentrations of picolinate reduced the sorption of Sr(2+) and increased the sorption rate of UO2(2+), demonstrating the potential importance of this complexing agent. These experiments provide a direct comparison of the sorption behaviour of Cs(+), Sr(2+) and UO2(2+)onto natural sand and an assessment of the relative effects of EDTA, NTA and picolinate on the selected elements. Copyright © 2013 Elsevier Ltd. All rights reserved.

Impact of radionuclide spatial variability on groundwater quality downstream from a shallow waste burial in the Chernobyl Exclusion Zone

NASA Astrophysics Data System (ADS)

Nguyen, H. L.; de Fouquet, C.; Courbet, C.; Simonucci, C. A.

2016-12-01

The effects of spatial variability of hydraulic parameters and initial groundwater plume localization on the possible extent of groundwater pollution plumes have already been broadly studied. However, only a few studies, such as Kjeldsen et al. (1995), take into account the effect of source term spatial variability. We explore this question with the 90Sr migration modeling from a shallow waste burial located in the Chernobyl Exclusion Zone to the underlying sand aquifer. Our work is based upon groundwater sampled once or twice a year since 1995 until 2015 from about 60 piezometers and more than 3,000 137Cs soil activity measurements. These measurements were taken in 1999 from one of the trenches dug after the explosion of the Chernobyl nuclear power plant, the so-called "T22 Trench", where radioactive waste was buried in 1987. The geostatistical analysis of 137Cs activity data in soils from Bugai et al. (2005) is first reconsidered to delimit the trench borders using georadar data as a covariable and to perform geostatistical simulations in order to evaluate the uncertainties of this inventory. 90Sr activity in soils is derived from 137Cs/154Eu and 90Sr/154Eu activity ratios in Chernobyl hot fuel particles (Bugai et al., 2003). Meanwhile, a coupled 1D non saturated/3D saturated transient transport model is constructed under the MELODIE software (IRSN, 2009). The previous 90Sr transport model developed by Bugai et al. (2012) did not take into account the effect of water table fluctuations highlighted by Van Meir et al. (2007) which may cause some discrepancies between model predictions and field observations. They are thus reproduced on a 1D vertical non saturated model. The equiprobable radionuclide localization maps produced by the geostatistical simulations are selected to illustrate different heterogeneities in the radionuclide inventory and are implemented in the 1D model. The obtained activity fluxes from all the 1D vertical models are then injected in a 3D saturated transient model to assess the extent of the radionuclide plume in the groundwater and its most likely evolution over time by taking into account uncertainties associated with the source term spatial variability.

Three-dimensional DFN Model Development and Calibration: A Case Study for Pahute Mesa, Nevada National Security Site

NASA Astrophysics Data System (ADS)

Pham, H. V.; Parashar, R.; Sund, N. L.; Pohlmann, K.

2017-12-01

Pahute Mesa, located in the north-western region of the Nevada National Security Site, is an area where numerous underground nuclear tests were conducted. The mesa contains several fractured aquifers that can potentially provide high permeability pathways for migration of radionuclides away from testing locations. The BULLION Forced-Gradient Experiment (FGE) conducted on Pahute Mesa injected and pumped solute and colloid tracers from a system of three wells for obtaining site-specific information about the transport of radionuclides in fractured rock aquifers. This study aims to develop reliable three-dimensional discrete fracture network (DFN) models to simulate the BULLION FGE as a means for computing realistic ranges of important parameters describing fractured rock. Multiple conceptual DFN models were developed using dfnWorks, a parallelized computational suite developed by Los Alamos National Laboratory, to simulate flow and conservative particle movement in subsurface fractured rocks downgradient from the BULLION test. The model domain is 100x200x100 m and includes the three tracer-test wells of the BULLION FGE and the Pahute Mesa Lava-flow aquifer. The model scenarios considered differ from each other in terms of boundary conditions and fracture density. For each conceptual model, a number of statistically equivalent fracture network realizations were generated using data from fracture characterization studies. We adopt the covariance matrix adaptation-evolution strategy (CMA-ES) as a global local stochastic derivative-free optimization method to calibrate the DFN models using groundwater levels and tracer breakthrough data obtained from the three wells. Models of fracture apertures based on fracture type and size are proposed and the values of apertures in each model are estimated during model calibration. The ranges of fracture aperture values resulting from this study are expected to enhance understanding of radionuclide transport in fractured rocks and support development of improved large-scale flow and transport models for Pahute Mesa.

Radiation-Induced Defects in Kaolinite as Tracers of Past Occurrence of Radionuclides in a Natural Analogue of High Level Nuclear Waste Repository

NASA Astrophysics Data System (ADS)

Allard, T.; Fourdrin, C.; Calas, G.

2007-05-01

Understanding the processes controlling migrations of radioelements at the Earth's surface is an important issue for the long-term safety assessment of high level nuclear waste repositories (HLNWR). Evidence of past occurrence and transfer of radionuclides can be found using radiation-induced defects in minerals. Clay minerals are particularly relevant because of their widespread occurrence at the Earth's surface and their finely divided nature which provides high contact area with radioactive fluids. Owing to its sensitivity to radiations, kaolinite can be used as natural, in situ dosimeter. Kaolinite is known to contain radiation-induced defects which are detected by Electron Paramagnetic Resonance. They are differentiated by their nature, their production kinetics and their thermal stability. One of these defects is stable at the scale of geological periods and provides a record of past radionuclide occurrence. Based on artificial irradiations, a methodology has been subsequently proposed to determine paleodose cumulated by kaolinite since its formation. The paleodose can be used to derive equivalent radioelement concentrations, provided that the age of kaolinite formation can be constrained. This allows quantitative reconstruction of past transfers of radioelements in natural systems. An example is given for the Nopal I U-deposit (Chihuahua, Mexico), hosted in hydrothermally altered volcanic tufs and considered as analogue of the Yucca Mountain site. The paleodoses experienced by kaolinites were determined from the concentration of defects and dosimetry parameters of experimental irradiations. Using few geochemical assumption, a equivalent U-content responsible for defects in kaolinite was calculated from the paleodose, a dose rate balance and model ages of kaolinites constrained by tectonic phases. In a former study, the ages were assumptions derived from regional tectonic events. In thepresent study, ages of mineralization events are measured from U systematics. The corresponding results reveal past accumulation of uranium in the mineralized zone and past leaching in the fissure network of the present barren rock. Geochemical implications for HLNWR will be discussed.

Task 3: PNNL Visit by JAEA Researchers to Participate in TODAM Code Applications to Fukushima Rivers and to Evaluate the Feasibility of Adaptation of FLESCOT Code to Simulate Radionuclide Transport in the Pacific Ocean Coastal Water Around Fukushima

DOE Office of Scientific and Technical Information (OSTI.GOV)

Onishi, Yasuo

Four JAEA researchers visited PNNL for two weeks in February, 2013 to learn the PNNL-developed, unsteady, one-dimensional, river model, TODAM and the PNNL-developed, time-dependent, three dimensional, coastal water model, FLESCOT. These codes predict sediment and contaminant concentrations by accounting sediment-radionuclide interactions, e.g., adsorption/desorption and transport-deposition-resuspension of sediment-sorbed radionuclides. The objective of the river and coastal water modeling is to simulate • 134Cs and 137Cs migration in Fukushima rivers and the coastal water, and • their accumulation in the river and ocean bed along the Fukushima coast. Forecasting the future cesium behavior in the river and coastal water under various scenariosmore » would enable JAEA to assess the effectiveness of various on-land remediation activities and if required, possible river and coastal water clean-up operations to reduce the contamination of the river and coastal water, agricultural products, fish and other aquatic biota. PNNL presented the following during the JAEA visit to PNNL: • TODAM and FLESCOT’s theories and mathematical formulations • TODAM and FLESCOT model structures • Past TODAM and FLESCOT applications • Demonstrating these two codes' capabilities by applying them to simple hypothetical river and coastal water cases. • Initial application of TODAM to the Ukedo River in Fukushima and JAEA researchers' participation in its modeling. PNNL also presented the relevant topics relevant to Fukushima environmental assessment and remediation, including • PNNL molecular modeling and EMSL computer facilities • Cesium adsorption/desorption characteristics • Experiences of connecting molecular science research results to macro model applications to the environment • EMSL tour • Hanford Site road tour. PNNL and JAEA also developed future course of actions for joint research projects on the Fukushima environmental and remediation assessments.« less

Plutonium Interactions with Pseudomonas sp. and its Extracellular Polymeric Substances (Sorption and Reduction of Plutonium by Bacterial Extracellular Polymeric Substances)

DOE PAGES

Boggs, Mark A.; Jiao, Yongqin; Dai, Zurong; ...

2016-09-30

Safe and effective nuclear waste disposal, as well as accidental radionuclide releases, necessitates our understanding of the fate of radionuclides in the environment, including their interaction with microorganisms. We examined the sorption of Pu(IV) and Pu(V) toPseudomonassp. strain EPS-1W, an aerobic bacterium isolated from plutonium (Pu) contaminated groundwater collected in the United States at the Nevada National Security Site (NNSS), Nevada. We compared Pu sorption to cells with and without bound extracellular polymeric substances (EPS). Wild type cells with intact EPS sorbed Pu(V) more effectively than cells with EPS removed. In contrast, cells with and without EPS showed the samemore » sorption affinity for Pu(IV).In vitroexperiments with extracted EPS revealed rapid reduction of Pu(V) to Pu(IV). Transmission Electron Microscopy indicated that 2-3 nm nanocrystalline Pu(IV)O 2formed on cells equilibrated with high concentrations of Pu(IV) but not Pu(V). Thus, EPS, while facilitating Pu(V) reduction, inhibit the formation of nanocrystalline Pu(IV) precipitates. ImportanceOur results indicate that EPS are an effective reductant for Pu(V) and sorbent for Pu(IV), and may impact Pu redox cycling and mobility in the environment. Additionally, the resulting Pu morphology associated with EPS will depend on the concentration and initial Pu oxidation state. While our results are not directly applicable to the Pu transport situation at the NNSS, the results suggest that, in general, stationary microorganisms and biofilms will tend to limit the migration of Pu and provide an important Pu retardation mechanism in the environment. In a broader sense, our results along with a growing body of literature highlight the important role of microorganisms as producers of redox-active organic ligands and therefore as modulators of radionuclide redox transformations and complexation in the subsurface.« less

Plutonium Interactions with Pseudomonas sp. and its Extracellular Polymeric Substances (Sorption and Reduction of Plutonium by Bacterial Extracellular Polymeric Substances)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boggs, Mark A.; Jiao, Yongqin; Dai, Zurong

Safe and effective nuclear waste disposal, as well as accidental radionuclide releases, necessitates our understanding of the fate of radionuclides in the environment, including their interaction with microorganisms. We examined the sorption of Pu(IV) and Pu(V) toPseudomonassp. strain EPS-1W, an aerobic bacterium isolated from plutonium (Pu) contaminated groundwater collected in the United States at the Nevada National Security Site (NNSS), Nevada. We compared Pu sorption to cells with and without bound extracellular polymeric substances (EPS). Wild type cells with intact EPS sorbed Pu(V) more effectively than cells with EPS removed. In contrast, cells with and without EPS showed the samemore » sorption affinity for Pu(IV).In vitroexperiments with extracted EPS revealed rapid reduction of Pu(V) to Pu(IV). Transmission Electron Microscopy indicated that 2-3 nm nanocrystalline Pu(IV)O 2formed on cells equilibrated with high concentrations of Pu(IV) but not Pu(V). Thus, EPS, while facilitating Pu(V) reduction, inhibit the formation of nanocrystalline Pu(IV) precipitates. ImportanceOur results indicate that EPS are an effective reductant for Pu(V) and sorbent for Pu(IV), and may impact Pu redox cycling and mobility in the environment. Additionally, the resulting Pu morphology associated with EPS will depend on the concentration and initial Pu oxidation state. While our results are not directly applicable to the Pu transport situation at the NNSS, the results suggest that, in general, stationary microorganisms and biofilms will tend to limit the migration of Pu and provide an important Pu retardation mechanism in the environment. In a broader sense, our results along with a growing body of literature highlight the important role of microorganisms as producers of redox-active organic ligands and therefore as modulators of radionuclide redox transformations and complexation in the subsurface.« less

Radiostrontium hot spot in the Russian Arctic: ground surface contamination by (90)Sr at the "Kraton-3" underground nuclear explosion site.

PubMed

Ramzaev, Valery; Mishine, Arkady; Basalaeva, Larisa; Brown, Justin

2007-01-01

Strontium-90 activity concentrations in surface soils and areal deposition densities have been studied at a site contaminated by an accidental release to atmosphere from the underground nuclear explosion "Kraton-3" conducted near the Polar Circle (65.9 degrees N, 112.3 degrees E) within the territory of the former USSR in 1978. In 2001-2002, the ground surface contamination at 14 plots studied ranged from 20 to 15 000 kBq m(-2), which significantly exceeds the value of 0.44 kBq m(-2) deduced for three background plots. The zone with substantial radiostrontium contamination extends, at least, 2.5 km in a north-easterly direction from the borehole. The average (137)Cs/(90)Sr ratio in the ground contamination originated from the "Kraton-3" fallout was estimated to be 0.55, which is significantly different from the ratio of 2.05 evaluated for background plots contaminated mostly from global fallout. Although vertical migration of (90)Sr in all undisturbed soil profiles studied is more rapid than that for (137)Cs, the depth of percolation of both radionuclides into the ground is mostly limited to the top 10-20 cm, which may be explained, primarily, by permafrost conditions. The horizontal migration rate of radiostrontium in the aqueous phase exceeds the radiocaesium migration rate by many times. This phenomenon seems to be a reason for the significant enrichment of the soil surface layers by radiostrontium at some sites, with variations occurring in accordance with small-scale irregularities of landscape.

Actinide geochemistry: from the molecular level to the real system.

PubMed

Geckeis, Horst; Rabung, Thomas

2008-12-12

Geochemical processes leading to either mobilization or retention of radionuclides in an aquifer system are significantly influenced by their interaction with rock, sediment and colloid surfaces. Therefore, a sound safety assessment of nuclear waste disposal requires the elucidation and quantification of those processes. State-of-the-art analytical techniques as e.g. laser- and X-ray spectroscopy are increasingly applied to study solid-liquid interface reactions to obtain molecular level speciation insight. We have studied the sorption of trivalent lanthanides and actinides onto aluminium oxides, hydroxides and purified clay minerals by the time-resolved laser fluorescence spectroscopy and X-ray-absorption spectroscopy. Chemical constitution and structure of surface bound actinides are proposed based on spectroscopic information. Open questions still remain with regard to the exact nature of mineral surface ligands and the mineral/water interface. Similarities of spectroscopic data obtained for M(III) sorbed onto gamma-alumina, and clay minerals suggest the formation of very comparable inner-sphere surface complexes such as S-O-An(III)(OH)x(2-x)(H2O)5-x at pH > 5. Those speciation data are found consistent with those predicted by surface complexation modelling. The applicability of data obtained for pure mineral phases to actinide sorption onto heterogeneously composed natural clay rock is examined by experiments and by geochemical modelling. Good agreement of experiment and model calculations is found for U(VI) and trivalent actinide/lanthanide sorption to natural clay rock. The agreement of spectroscopy, geochemical modelling and batch experiments with natural rock samples and purified minerals increases the reliability in model predictions. The assessment of colloid borne actinide migration observed in various laboratory and field studies calls for detailed information on actinide-colloid interaction. Kinetic stabilization of colloid bound actinides can be due to inclusion into inorganic colloid matrix or by macromolecular rearrangement in case of organic, humic/fulvic like colloids. Only a combination of spectroscopy, microscopy and classical batch sorption experiments can help to elucidate the actinide-colloid interaction mechanisms and thus contribute to the assessment of colloids for radionuclide migration.

49 CFR 173.433 - Requirements for determining basic radionuclide values, and for the listing of radionuclides on...

Code of Federal Regulations, 2010 CFR

2010-10-01

... radionuclide values, and for the listing of radionuclides on shipping papers and labels. (a) For individual... given in the table in § 173.436. (b) For individual radionuclides which are not listed in the tables in.... (d) Mixtures of radionuclides whose identities and respective activities are known must conform to...

49 CFR 173.433 - Requirements for determining basic radionuclide values, and for the listing of radionuclides on...

Code of Federal Regulations, 2011 CFR

2011-10-01

... radionuclide values, and for the listing of radionuclides on shipping papers and labels. (a) For individual... given in the table in § 173.436. (b) For individual radionuclides which are not listed in the tables in.... (d) Mixtures of radionuclides whose identities and respective activities are known must conform to...

49 CFR 173.433 - Requirements for determining basic radionuclide values, and for the listing of radionuclides on...

Code of Federal Regulations, 2013 CFR

2013-10-01

... radionuclide values, and for the listing of radionuclides on shipping papers and labels. (a) For individual... given in the table in § 173.436. (b) For individual radionuclides which are not listed in the tables in.... (d) Mixtures of radionuclides whose identities and respective activities are known must conform to...

49 CFR 173.433 - Requirements for determining basic radionuclide values, and for the listing of radionuclides on...

Code of Federal Regulations, 2012 CFR

2012-10-01

... radionuclide values, and for the listing of radionuclides on shipping papers and labels. (a) For individual... given in the table in § 173.436. (b) For individual radionuclides which are not listed in the tables in.... (d) Mixtures of radionuclides whose identities and respective activities are known must conform to...

Efficiency of a borehole seal by means of pre-compacted bentonite blocks

NASA Astrophysics Data System (ADS)

Van Geet, M.; Volckaert, G.; Bastiaens, W.; Maes, N.; Weetjens, E.; Sillen, X.; Vallejan, B.; Gens, A.

The backfilling and sealing of shafts and galleries is an essential part of the design of underground repositories for high-level radioactive waste. Part of the EC funded project RESEAL studied the feasibility of sealing off a borehole in plastic Boom Clay by means of pre-compacted bentonite blocks. Two bentonites, namely the FoCa and Serrata clay, have been used. Based on laboratory tests, the bentonite blocks had an initial dry density of about 1.8 g/cm 3 to obtain a swelling pressure of about 4.4 MPa, corresponding to the in situ lithostatic stress, at full saturation. The set-up was equipped with several sensors to follow-up the behaviour of the seal and the surrounding host rock during hydration. Full saturation was reached after five months and was mainly reached by natural hydration. Swelling pressure was lower than originally foreseen due to the slow reconsolidation of the host rock. Later on, the efficiency of the seal with respect to water, gas and radionuclide migration was tested. The in situ measured permeability of the seals was about 5 × 10 -13 m/s. A gas breakthrough experiment did not show any preferential gas migration through the seal. No evidences of a preferential pathway could be detected from 125I tracer test results.

Delayed signatures of underground nuclear explosions

DOE PAGES

Carrigan, Charles R.; Sun, Yunwei; Hunter, Steven L.; ...

2016-03-16

Radionuclide signals from underground nuclear explosions (UNEs) are strongly influenced by the surrounding hydrogeologic regime. One effect of containment is delay of detonation-produced radioxenon reaching the surface as well as lengthening of its period of detectability compared to uncontained explosions. Using a field-scale tracer experiment, we evaluate important transport properties of a former UNE site. Here, we observe the character of signals at the surface due to the migration of gases from the post-detonation chimney under realistic transport conditions. Background radon signals are found to be highly responsive to cavity pressurization suggesting that large local radon anomalies may be anmore » indicator of a clandestine UNE. Computer simulations, using transport properties obtained from the experiment, track radioxenon isotopes in the chimney and their migration to the surface. They show that the chimney surrounded by a fractured containment regime behaves as a leaky chemical reactor regarding its effect on isotopic evolution introducing a dependence on nuclear yield not previously considered. This evolutionary model for radioxenon isotopes is validated by atmospheric observations of radioxenon from a 2013 UNE in the Democratic People’s Republic of Korea (DPRK). In conclusion, our model produces results similar to isotopic observations with nuclear yields being comparable to seismic estimates.« less

Temporary vs. Permanent Sub-slab Ports: A Comparative ...

EPA Pesticide Factsheets

Vapor intrusion (VI) is the migration of subsurface vapors, including radon and volatile organic compounds (VOCs), from the subsurface to indoor air. The VI exposure pathway extends from the contaminant source, which can be impacted soil, non-aqueous phase liquid, or contaminated groundwater, to indoor air-exposure points. Therefore, contaminated matrices may include groundwater, soil, soil gas, and indoor air. VOC contaminants of concern typically include halogenated solvents such as trichloroethene, tetrachloroethene, and chloroform, as well as petroleum hydrocarbons, such as the aromatic VOCs benzene, toluene, and xylenes. Radon is a colorless radioactive gas that is released by radioactive decay of radionuclides in rock and soil that migrate into homes through VI in a similar fashion to VOCs. This project focused on the performance of permanent versus temporary sub-slab sampling ports for the determination of VI of halogenated VOCs and radon into an unoccupied house. VOC and radon concentrations measured simultaneously in soil gas using collocated temporary and permanent ports appeared to be independent of the type of port. The variability between collocated temporary and permanent ports was much less than the spatial variability between different locations within a single residential duplex. The agreement of the majority of VOC and radon concentrations, 0–36% relative percent difference, and 2–19% relative standard deviation respectively, of each sub-sl

Radionuclide concentration processes in marine organisms: A comprehensive review.

PubMed

Carvalho, Fernando P

2018-06-01

The first measurements made of artificial radionuclides released into the marine environment did reveal that radionuclides are concentrated by marine biological species. The need to report radionuclide accumulation in biota in different conditions and geographical areas prompted the use of concentration factors as a convenient way to describe the accumulation of radionuclides in biota relative to radionuclide concentrations in seawater. Later, concentration factors became a tool in modelling radionuclide distribution and transfer in aquatic environments and to predicting radioactivity in organisms. Many environmental parameters can modify the biokinetics of accumulation and elimination of radionuclides in marine biota, but concentration factors remained a convenient way to describe concentration processes of radioactive and stable isotopes in aquatic organisms. Revision of CF values is periodically undertaken by international organizations, such as the International Atomic Energy Agency (IAEA), to make updated information available to the international community. A brief commented review of radionuclide concentration processes and concentration factors in marine organisms is presented for key groups of radionuclides such as fission products, activation products, transuranium elements, and naturally-occurring radionuclides. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radionuclide detection devices and associated methods

DOEpatents

Mann, Nicholas R [Rigby, ID; Lister, Tedd E [Idaho Falls, ID; Tranter, Troy J [Idaho Falls, ID

2011-03-08

Radionuclide detection devices comprise a fluid cell comprising a flow channel for a fluid stream. A radionuclide collector is positioned within the flow channel and configured to concentrate one or more radionuclides from the fluid stream onto at least a portion of the radionuclide collector. A scintillator for generating scintillation pulses responsive to an occurrence of a decay event is positioned proximate at least a portion of the radionuclide collector and adjacent to a detection system for detecting the scintillation pulses. Methods of selectively detecting a radionuclide are also provided.

Studies of the mobility of uranium and thorium in Nevada Test Site tuff

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wollenberg, H.A.; Flexser, S.; Smith, A.R.

1991-06-01

Hydro-geochemical processes must be understood if the movement of radionuclides away from a breached radioactive waste canister is to be modeled and predicted. In this respect, occurrences of uranium and thorium in hydrothermal systems are under investigation in tuff and in rhyolitic tuff that was heated to simulate the effects of introduction of radioactive waste. In these studies, high-resolution gamma spectrometry and fission-track radiography are coupled with observations of alteration mineralogy and thermal history to deduce the evidence of, or potential for movement of, U and Th in response to the thermal environment. Observations to date suggest that U wasmore » mobile in the vicinity of the heater but that localized reducing environments provided by Fe-Ti-Mn-oxide minerals concentrated U and thus attenuated its migration.« less

Observations on the geology and geohydrology of the Chernobyl' nuclear accident site, Ukraine

USGS Publications Warehouse

Matzko, J.R.; Percious, D.J.; Rachlin, J.; Marples, D.R.

1994-01-01

The most highly contaminated surface areas from cesium-137 fallout from the April 1986 accident at the Chernobyl' nuclear power station in Ukraine occur within the 30-km radius evacuation zone set up around the station, and an 80-km lobe extending to the west-southwest. Lower levels of contamination extend 300 km to the west of the power station. The geology, the presence of surface water, a shallow water table, and leaky aquifers at depth make this an unfavorable environment for the long-term containment and storage of the radioactive debris. An understanding of the general geology and hydrology of the area is important to assess the environmental impact of this unintended waste storage site, and to evaluate the potential for radionuclide migration through the soil and rock and into subsurface aquifers and nearby rivers. -from Authors

Armored Enzyme Nanoparticles for Remediation of Subsurface

DOE Office of Scientific and Technical Information (OSTI.GOV)

Grate, Jay W.

2005-09-01

The remediation of subsurface contaminants is a critical problem for the Department of Energy, other government agencies, and our nation. Severe contamination of soil and groundwater exists at several DOE sites due to various methods of intentional and unintentional release. Given the difficulties involved in conventional removal or separation processes, it is vital to develop methods to transform contaminants and contaminated earth/water to reduce risks to human health and the environment. Transformation of the contaminants themselves may involve conversion to other immobile species that do not migrate into well water or surface waters, as is proposed for metals and radionuclides;more » or degradation to harmless molecules, as is desired for organic contaminants. Transformation of contaminated earth (as opposed to the contaminants themselves) may entail reductions in volume or release of bound contaminants for remediation.« less

PCR detection of groundwater bacteria associated with colloidal transport

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cruz-Perez, P.; Stetzenbach, L.D.; Alvarez, A.J.

1996-02-29

Colloidal transport may increase the amount of contaminant material than that which could be transported by water flow alone. The role of colloids in groundwater contaminant transport is complicated and may involve many different processes, including sorption of elements onto colloidal particles, coagulation/dissolution, adsorption onto solid surfaces, filtration, and migration. Bacteria are known to concentrate minerals and influence the transport of compounds in aqueous environments and may also serve as organic colloids, thereby influencing subsurface transport of radionuclides and other contaminants. The initial phase of the project consisted of assembling a list of bacteria capable of sequestering or facilitating mineralmore » transport. The development and optimization of the PCR amplification assay for the detection of the organisms of interest, and the examination of regional groundwaters for those organisms, are presented for subsequent research.« less

Predicting the impact of land management decisions on overland flow generation: Implications for cesium migration in forested Fukushima watersheds

NASA Astrophysics Data System (ADS)

Siirila-Woodburn, Erica R.; Steefel, Carl I.; Williams, Kenneth H.; Birkholzer, Jens T.

2018-03-01

The effects of land use and land cover (LULC) change on environmental systems across the land surface's "critical zone" are highly uncertain, often making prediction and risk management decision difficult. In a series of numerical experiments with an integrated hydrologic model, overland flow generation is quantified for both present day and forest thinning scenarios. A typhoon storm event in a watershed near the Fukushima Dai-ichi Nuclear Power Plant is used as an example application in which the interplay between LULC change and overland flow generation is important given that sediment-bound radionuclides may cause secondary contamination via surface water transport. Results illustrate the nonlinearity of the integrated system spanning from the deep groundwater to the atmosphere, and provide quantitative tools when determining the tradeoffs of different risk-mitigation strategies.

Beryllium-7 and lead-210 chronometry of modern soil processes: The Linked Radionuclide aCcumulation model, LRC

NASA Astrophysics Data System (ADS)

Landis, Joshua D.; Renshaw, Carl E.; Kaste, James M.

2016-05-01

Soil systems are known to be repositories for atmospheric carbon and metal contaminants, but the complex processes that regulate the introduction, migration and fate of atmospheric elements in soils are poorly understood. This gap in knowledge is attributable, in part, to the lack of an established chronometer that is required for quantifying rates of relevant processes. Here we develop and test a framework for adapting atmospheric lead-210 chronometry (210Pb; half-life 22 years) to soil systems. We propose a new empirical model, the Linked Radionuclide aCcumulation model (LRC, aka "lark"), that incorporates measurements of beryllium-7 (7Be; half-life 54 days) to account for 210Pb penetration of the soil surface during initial deposition, a process which is endemic to soils but omitted from conventional 210Pb models (e.g., the Constant Rate of Supply, CRS model) and their application to sedimentary systems. We validate the LRC model using the 1963-1964 peak in bomb-fallout americium-241 (241Am; half-life of 432 years) as an independent, corroborating time marker. In three different soils we locate a sharp 241Am weapons horizon at disparate depths ranging from 2.5 to 6 cm, but with concordant ages averaging 1967 ± 4 via the LRC model. Similarly, at one site contaminated with mercury (HgT) we find that the LRC model is consistent with the recorded history of Hg emission. The close agreement of Pb, Am and Hg behavior demonstrated here suggests that organo-metallic colloid formation and migration incorporates many trace metals in universal soil processes and that these processes may be described quantitatively using atmospheric 210Pb chronometry. The 210Pb models evaluated here show that migration rates of soil colloids on the order of 1 mm yr-1 are typical, but also that these rates vary systematically with depth and are attributable to horizon-specific processes of leaf-litter decay, eluviation and illuviation. We thus interpret 210Pb models to quantify (i) exposure of the soil system to atmospheric aerosol deposition in the context of (ii) organic carbon assimilation, colloid production, and advection through the soil profile. The behavior of some other elements, such as Cs, diverges from the conservative colloid behavior exemplified by Pb and Am, and in these cases the value of empirical 210Pb chronometry models like LRC and CRS is as a comparator rather than as an absolute chronometer. We conclude that 210Pb chronometry is valuable for tracing colloidally-mediated transport of Pb and similarly-refractory metals, as well as the mobile pool of carbon in soils.

Innovative Strategy For Long Term Monitoring Of Metal And Radionuclide Plumes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Eddy-Dilek, Carol; Millings, Margaret R.; Looney, Brian B.

2014-01-08

Many government and private industry sites that were once contaminated with radioactive and chemical wastes cannot be cleaned up enough to permit unrestricted human access. The sites will require long term management, in some cases indefinitely, leaving site owners with the challenge of protecting human health and environmental quality at these "legacy" sites. Long-term monitoring of groundwater contamination is one of the largest projected costs in the life cycle of environmental management at the Savannah River Site, the larger DOE complex, and many large federal and private sites. There is a need to optimize the performance and manage the costmore » of long term surveillance and monitoring at their sites. Currently, SRNL is initiating a pilot field test using alternative protocols for long term monitoring of metals and radionuclides. A key component of the approach is that monitoring efforts are focused on measurement of low cost metrics related to hydrologic and chemical conditions that control contaminant migration. The strategy combines careful monitoring of hydrologic boundary conditions with measurement of master variables such as chemical surrogates along with a smaller number of standard well analyses. In plumes contaminated with metals, master variables control the chemistry of the groundwater system, and include redox variables (ORP, DO, chemicals), pH, specific conductivity, biological community (breakdown/decay products), and temperature. Significant changes in these variables will result in conditions whereby the plume may not be stable and therefore can be used to predict possible plume migration. Conversely, concentration measurements for all types of contaminants in groundwater are a lagging indicator plume movement - major changes contaminant concentrations indicate that contamination has migrated. An approach based on measurement of master variables and explicit monitoring of hydrologic boundary conditions combined with traditional metrics should lead to improved monitoring while simultaneously reducing costs. This paradigm is being tested at the SRS F-Area where an innovative passive remedial system is being monitored and evaluated over the long term prior to traditional regulatory closure. Contaminants being addressed at this site are uranium, strontium-90, iodine-129, and tritium. We believe that the proposed strategies will be more effective in early identification of potential risks; these strategies will also be cost effective because controlling variables are relatively simple to measure. These variables also directly reflect the evolution of the plume through time, so that the monitoring strategy can be modified as the plume 'ages'. This transformational long-term monitoring paradigm will generate large cost savings to DOE, other federal agencies and industry and will provide improved performance and leading indicators of environmental management performance.« less

Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant

PubMed Central

Furuki, Genki; Imoto, Junpei; Ochiai, Asumi; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Grambow, Bernd; Ewing, Rodney C.; Utsunomiya, Satoshi

2017-01-01

The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0–3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn–Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1–19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn–Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP. PMID:28198440

Modeling and identifying the sources of radiocesium contamination in separate sewerage systems.

PubMed

Pratama, Mochamad Adhiraga; Yoneda, Minoru; Yamashiki, Yosuke; Shimada, Yoko; Matsui, Yasuto

2018-05-01

The Fukushima Dai-ichi nuclear power plant accident released radiocesium in large amounts. The released radionuclides contaminated much of the surrounding environment, including sewers in urban areas of Fukushima prefecture. In this study we attempted to identify and quantify the sources of radiocesium contamination in separate sewerage systems and developed a compartment model based on the Radionuclide Migration in Urban Environments and Drainage Systems (MUD) model. Measurements of the time-dependent radiocesium concentration in sewer sludge combined with meteorological, demographic, and radiocesium dietary intake data indicated that rainfall-derived inflow and infiltration (RDII) and human excretion were the chief contributors of radiocesium contamination in a separate sewerage system. The quantities of contamination derived from RDII and human excretion were calculated and used in the modified MUD model to simulate radiocesium contamination in sewers in three urban areas in Fukushima prefecture: Fukushima, Koriyama, and Nihonmatsu Cities. The Nash efficiency coefficient (0.88-0.92) and determination coefficient (0.89-0.93) calculated in an evaluation of our compartment model indicated that the model produced satisfactory results. We also used the model to estimate the total volume of sludge with radiocesium concentrations in excess of the clearance level, based on the number of months elapsed after the accident. Estimations by our model suggested that wastewater treatment plants (WWTPs) in Fukushima, Koriyama, and Nihonmatsu generated about 1,750,000m 3 of radioactive sludge in total, a level in good agreement with the real data. Copyright © 2017 Elsevier B.V. All rights reserved.

Interaction of 3H+ (as HTO) and 36Cl- (as Na36Cl) with crushed granite and corresponding fracture infill material investigated in column experiments.

PubMed

Štamberg, K; Palágyi, Š; Videnská, K; Havlová, V

The transport of 3 H + (as HTO) and 36 Cl - (as Na 36 Cl) was investigated in the dynamic system, i.e., in the columns filled with crushed pure granite and fracture infill of various grain sizes. The aim of column experiments was to determine important transport parameter, such as the retardation, respectively distribution coefficients, Peclet numbers and hydrodynamic dispersion coefficients. Furthermore, the research was focused to quantification of the effect of grain size on migration of studied radionuclides. The experimental breakthrough curves were fitted by a model based on the erfc-function, assuming a linear reversible equilibrium sorption/desorption isotherm, and the above mentioned transport parameters were determined. The results showed that influence of grain size on sorption of 3 H + and 36 Cl - was negligible. Retardation and distribution coefficients of both tracers converged to one and zero, respectively, in case of all fractions of crushed granite and infill material. Generally, the presumed ion exclusion of 36 Cl in anionic form was proved under given conditions, only very weak one seems to exist in a case of infill material. In principal, both radionuclides behaved as non-sorbing, conservative tracers. On the other hand, the influence of grain size on Peclet numbers value and on dispersion coefficient was observed for both crystalline materials, namely in agreement with theoretical suppositions that the values of Peclet numbers decrease with increasing grain size and values of dispersion coefficient increase.

Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant

NASA Astrophysics Data System (ADS)

Furuki, Genki; Imoto, Junpei; Ochiai, Asumi; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Grambow, Bernd; Ewing, Rodney C.; Utsunomiya, Satoshi

2017-02-01

The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0-3.4 μm) comprise SiO2 glass matrices and ~10-nm-sized Zn-Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1-19 wt% Cs as Cs2O). Trace amounts of U are also associated with the Zn-Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP.

Delineation of the Pahute Mesa–Oasis Valley groundwater basin, Nevada

USGS Publications Warehouse

Fenelon, Joseph M.; Halford, Keith J.; Moreo, Michael T.

2016-01-22

This report delineates the Pahute Mesa–Oasis Valley (PMOV) groundwater basin, where recharge occurs, moves downgradient, and discharges to Oasis Valley, Nevada. About 5,900 acre-feet of water discharges annually from Oasis Valley, an area of springs and seeps near the town of Beatty in southern Nevada. Radionuclides in groundwater beneath Pahute Mesa, an area of historical underground nuclear testing at the Nevada National Security Site, are believed to be migrating toward Oasis Valley. Delineating the boundary of the PMOV groundwater basin is necessary to adequately assess the potential for transport of radionuclides from Pahute Mesa to Oasis Valley.The PMOV contributing area is defined based on regional water-level contours, geologic controls, and knowledge of adjacent flow systems. The viability of this area as the contributing area to Oasis Valley and the absence of significant interbasin flow between the PMOV groundwater basin and adjacent basins are shown regionally and locally. Regional constraints on the location of the contributing area boundary and on the absence of interbasin groundwater flow are shown by balancing groundwater discharges in the PMOV groundwater basin and adjacent basins against available water from precipitation. Internal consistency for the delineated contributing area is shown by matching measured water levels, groundwater discharges, and transmissivities with simulated results from a single-layer, steady-state, groundwater-flow model. An alternative basin boundary extending farther north than the final boundary was rejected based on a poor chloride mass balance and a large imbalance in the northern area between preferred and simulated recharge.

Caesium-rich micro-particles: A window into the meltdown events at the Fukushima Daiichi Nuclear Power Plant.

PubMed

Furuki, Genki; Imoto, Junpei; Ochiai, Asumi; Yamasaki, Shinya; Nanba, Kenji; Ohnuki, Toshihiko; Grambow, Bernd; Ewing, Rodney C; Utsunomiya, Satoshi

2017-02-15

The nuclear disaster at the Fukushima Daiichi Nuclear Power Plant (FDNPP) in March 2011 caused partial meltdowns of three reactors. During the meltdowns, a type of condensed particle, a caesium-rich micro-particle (CsMP), formed inside the reactors via unknown processes. Here we report the chemical and physical processes of CsMP formation inside the reactors during the meltdowns based on atomic-resolution electron microscopy of CsMPs discovered near the FDNPP. All of the CsMPs (with sizes of 2.0-3.4 μm) comprise SiO 2 glass matrices and ~10-nm-sized Zn-Fe-oxide nanoparticles associated with a wide range of Cs concentrations (1.1-19 wt% Cs as Cs 2 O). Trace amounts of U are also associated with the Zn-Fe oxides. The nano-texture in the CsMPs records multiple reaction-process steps during meltdown in the severe FDNPP accident: Melted fuel (molten core)-concrete interactions (MCCIs), incorporating various airborne fission product nanoparticles, including CsOH and CsCl, proceeded via SiO 2 condensation over aggregates of Zn-Fe oxide nanoparticles originating from the failure of the reactor pressure vessels. Still, CsMPs provide a mechanism by which volatile and low-volatility radionuclides such as U can reach the environment and should be considered in the migration model of Cs and radionuclides in the current environment surrounding the FDNPP.

Ion binding compounds, radionuclide complexes, methods of making radionuclide complexes, methods of extracting radionuclides, and methods of delivering radionuclides to target locations

DOEpatents

Chen, Xiaoyuan; Wai, Chien M.; Fisher, Darrell R.

2000-01-01

The invention pertains to compounds for binding lanthanide ions and actinide ions. The invention further pertains to compounds for binding radionuclides, and to methods of making radionuclide complexes. Also, the invention pertains to methods of extracting radionuclides. Additionally, the invention pertains to methods of delivering radionuclides to target locations. In one aspect, the invention includes a compound comprising: a) a calix[n]arene group, wherein n is an integer greater than 3, the calix[n]arene group comprising an upper rim and a lower rim; b) at least one ionizable group attached to the lower rim; and c) an ion selected from the group consisting of lanthanide and actinide elements bound to the ionizable group. In another aspect, the invention includes a method of extracting a radionuclide, comprising: a) providing a sample comprising a radionuclide; b) providing a calix[n]arene compound in contact with the sample, wherein n is an integer greater than 3; and c) extracting radionuclide from the sample into the calix[n]arene compound. In yet another aspect, the invention includes a method of delivering a radionuclide to a target location, comprising: a) providing a calix[n]arene compound, wherein n is an integer greater than 3, the calix[n]arene compound comprising at least one ionizable group; b) providing a radionuclide bound to the calix[n]arene compound; and c) providing an antibody attached to the calix[n]arene compound, the antibody being specific for a material found at the target location.

Identification of CSF fistulas by radionuclide counting

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yamamoto, Y.; Kunishio, K.; Sunami, N.

1990-07-01

A radionuclide counting method, performed with the patient prone and the neck flexed, was used successfully to diagnose CSF rhinorrhea in two patients. A normal radionuclide ratio (radionuclide counts in pledget/radionuclide counts in 1-ml blood sample) was obtained in 11 normal control subjects. Significance was determined to be a ratio greater than 0.37. Use of radionuclide counting method of determining CSF rhinorrhea is recommended when other methods have failed to locate a site of leakage or when posttraumatic meningitis suggests subclinical CSF rhinorrhea.

Natural and anthropogenic radionuclide activity concentrations in the New Zealand diet.

PubMed

Pearson, Andrew J; Gaw, Sally; Hermanspahn, Nikolaus; Glover, Chris N

2016-01-01

To support New Zealand's food safety monitoring regime, a survey was undertaken to establish radionuclide activity concentrations across the New Zealand diet. This survey was undertaken to better understand the radioactivity content of the modern diet and also to assess the suitability of the current use of milk as a sentinel for dietary radionuclide trends. Thirteen radionuclides were analysed in 40 common food commodities, including animal products, fruits, vegetables, cereal grains and seafood. Activity was detected for (137)Caesium, (90)Strontium and (131)Iodine. No other anthropogenic radionuclides were detected. Activity concentrations of the three natural radionuclides of Uranium and the daughter radionuclide (210)Polonium were detected in the majority of food sampled, with a large variation in magnitude. The maximum activity concentrations were detected in shellfish for all these radionuclides. Based on the established activity concentrations and ranges, the New Zealand diet contains activity concentrations of anthropogenic radionuclides far below the Codex Alimentarius guideline levels. Activity concentrations obtained for milk support its continued use as a sentinel for monitoring fallout radionuclides in terrestrial agriculture. The significant levels of natural and anthropogenic radionuclide activity concentrations detected in finfish and molluscs support undertaking further research to identify a suitable sentinel for New Zealand seafood monitoring. Copyright © 2015 The Authors. Published by Elsevier Ltd.. All rights reserved.

Depth profiling of Pu, 241Am and 137Cs in soils from southern Belarus measured by ICP-MS and alpha and gamma spectrometry.

PubMed

Boulyga, Sergei F; Zoriy, Myroslav; Ketterer, Michael E; Becker, J Sabine

2003-08-01

The depth distribution of plutonium, americium, and 137Cs originating from the 1986 accident at the Chernobyl Nuclear Power Plant (NPP) was investigated in several soil profiles in the vicinity from Belarus. The vertical migration of transuranic elements in soils typical of the 30 km relocation area around Chernobyl NPP was studied using inductively coupled plasma mass spectrometry (ICP-MS), alpha spectrometry, and gamma spectrometry. Transuranic concentrations in upper soil layers ranged from 6 x 10(-12) g g(-1) to 6 x 10(-10) g g(-1) for plutonium and from 1.8 x 10(-13) g g(-1) to 1.6 x 10(-11) g g(-1) for americium. These concentrations correspond to specific activities of (239+240)Pu of 24-2400 Bq kg(-1) and specific activity of 241Am of 23-2000 Bq kg(-1), respectively. Transuranics in turf-podzol soil migrate slowly to the deeper soil layers, thus, 80-95%, of radionuclide inventories were present in the 0-3 cm intervals of turf-podzol soils collected in 1994. In peat-marsh soil migration processes occur more rapidly than in turf-podzol and the maximum concentrations are found beneath the soil surface (down to 3-6 cm). The depth distributions of Pu and Am are essentially identical for a given soil profile. (239+240)Pu/137Cs and 241Am/137Cs activity ratios vary by up to a factor of 5 at some sites while smaller variations in these ratios were observed at a site close to Chernobyl, suggesting that 137Cs is dominantly particle associated close to Chernobyl but volatile species of 137Cs are of relatively greater importance at the distant sites.

Analysis of actinides in an ombrotrophic peat core - evidence of post-depositional migration of fallout radionuclides

NASA Astrophysics Data System (ADS)

Quinto, Francesca; Hrnecek, Erich; Krachler, Michael; Shotyk, William; Steier, Peter; Winkler, Stephan R.

2013-04-01

Plutonium (239Pu, 240Pu, 241Pu, 242Pu) and uranium (236U, 238U) isotopes were analyzed in an ombrotrophic peat core from the Black Forest, Germany, representing the last 80 years of atmospheric deposition. The reliable determination of these isotopes at ultra-trace levels was possible using ultra-clean laboratory procedures and accelerator mass spectrometry. The 240Pu/239Pu isotopic ratios are constant along the core with a mean value of 0.19 ±0.02 (N = 32). This result is consistent with the acknowledged average 240Pu/239Pu isotopic ratio from global fallout in the Northern Hemisphere. The global fallout origin of Pu is confirmed by the corresponding 241Pu/239Pu (0.0012 ±0.0005) and 242Pu/239Pu (0.004 ± 0.001) isotopic ratios. The identification of the Pu isotopic composition characteristic for global fallout in peat layers pre-dating the period of atmospheric atom bomb testing (AD 1956 - AD 1980) is a clear evidence of the migration of Pu downwards the peat profile. The maximum of global fallout derived 236U is detected in correspondence to the age/depth layer of maximum stratospheric fallout (AD 1963). This finding demonstrates that the 236U bomb peak can be successfully used as an independent chronological marker complementing the 210Pb dating of peat cores. The profiles of the global fallout derived 236U and 239Pu are compared with those of 137Cs and 241Am. As typical of ombrothrophic peat, the temporal fallout pattern of 137Cs is poorly retained. Similarly like for Pu, post-depositional migration of 241Am in peat layers preceding the era of atmospheric nuclear tests is observed.

Shielding and activity estimator for template-based nuclide identification methods

DOEpatents

Nelson, Karl Einar

2013-04-09

According to one embodiment, a method for estimating an activity of one or more radio-nuclides includes receiving one or more templates, the one or more templates corresponding to one or more radio-nuclides which contribute to a probable solution, receiving one or more weighting factors, each weighting factor representing a contribution of one radio-nuclide to the probable solution, computing an effective areal density for each of the one more radio-nuclides, computing an effective atomic number (Z) for each of the one more radio-nuclides, computing an effective metric for each of the one or more radio-nuclides, and computing an estimated activity for each of the one or more radio-nuclides. In other embodiments, computer program products, systems, and other methods are presented for estimating an activity of one or more radio-nuclides.

Selected radionuclides important to low-level radioactive waste management

DOE Office of Scientific and Technical Information (OSTI.GOV)

NONE

1996-11-01

The purpose of this document is to provide information to state representatives and developers of low level radioactive waste (LLW) management facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the environment. Extensive surveys of available literature provided information for this report. Certain radionuclides may contribute significantly to the dose estimated during a radiological performance assessment analysis of an LLW disposal facility. Among these are the radionuclides listed in Title 10 of the Code of Federal Regulations Part 61.55, Tables 1 and 2 (including alpha emitting transuranics with half-lives greater than 5 years). Thismore » report discusses these radionuclides and other radionuclides that may be significant during a radiological performance assessment analysis of an LLW disposal facility. This report not only includes essential information on each radionuclide, but also incorporates waste and disposal information on the radionuclide, and behavior of the radionuclide in the environment and in the human body. Radionuclides addressed in this document include technetium-99, carbon-14, iodine-129, tritium, cesium-137, strontium-90, nickel-59, plutonium-241, nickel-63, niobium-94, cobalt-60, curium -42, americium-241, uranium-238, and neptunium-237.« less

Preliminary Interpretation of a Radionuclide and Colloid Tracer Test in a Granodiorite Shear Zone at the Grimsel Test Site, Switzerland

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reimus, Paul W.

2012-08-30

In February and March 2012, a tracer test involving the injection of a radionuclide-colloid cocktail was conducted in the MI shear zone at the Grimsel Test Site, Switzerland, as part of the Colloids Formation and Migration (CFM) project. The colloids were derived from FEBEX bentonite, which is mined in Spain and is being considered as a potential waste package backfill in a Spanish nuclear waste repository. The tracer test, designated test 12-02 (second test in 2012), involved the injection of the tracer cocktail into borehole CFM 06.002i2 and extraction from the Pinkel surface packer at the main access tunnel wallmore » approximately 6.1 m from the injection interval. The test configuration is depicted in Figure 1. This configuration has been used in several conservative tracer tests and two colloid-homologue tracer tests since 2007, and it is will be employed in an upcoming test involving the emplacement of a radionuclide-doped bentonite plug into CFM 06.002i2 to evaluate the swelling and erosion of the bentonite and the transport of bentonite colloids and radionuclides from the source to the extraction point at the tunnel wall. Interpretive analyses of several of the previous tracer tests, from 09-01 through 12-02 were provided in two previous Used Fuel Disposition Program milestone reports (Arnold et al., 2011; Kersting et al., 2012). However, only the data for the conservative tracer Amino-G Acid was previously analyzed from test 12-02 because the other tracer data from this test were not available at the time. This report documents the first attempt to quantitatively analyze the radionuclide and colloid breakthrough curves from CFM test 12-02. This report was originally intended to also include an experimental assessment of colloid-facilitated transport of uranium by bentonite colloids in the Grimsel system, but this assessment was not conducted because it was reported by German collaborators at the Karlsruhe Institute of Technology (KIT) that neither uranium nor neptunium adsorbed appreciably to FEBEX bentonite colloids in Grimsel groundwater (Huber et al., 2011). The Grimsel groundwater has a relatively high pH of {approx}9, so the lack of uranium and neptunium adsorption to clay is not surprising given the tendency for these actinides to form very stable negative or neutrally-charged uranyl- or calcium-uranyl-carbonate complexes at these pH, particularly in a water that is effectively saturated with respect to calcite. It was also observed in testing conducted at LANL earlier in 2012 that uranium did not adsorb measurably to Grimsel granodiorite in a synthetic Grimsel groundwater at pH {approx}8.5 (Kersting et al., 2012). Thus, the planned experimental work was not pursued because all the available information clearly pointed to an expected result that uranium transport would not be facilitated by clay colloids in the Grimsel system.« less

Modeling Np and Pu transport with a surface complexation model and spatially variant sorption capacities: Implications for reactive transport modeling and performance assessments of nuclear waste disposal sites

USGS Publications Warehouse

Glynn, P.D.

2003-01-01

One-dimensional (1D) geochemical transport modeling is used to demonstrate the effects of speciation and sorption reactions on the ground-water transport of Np and Pu, two redox-sensitive elements. Earlier 1D simulations (Reardon, 1981) considered the kinetically limited dissolution of calcite and its effect on ion-exchange reactions (involving 90Sr, Ca, Na, Mg and K), and documented the spatial variation of a 90Sr partition coefficient under both transient and steady-state chemical conditions. In contrast, the simulations presented here assume local equilibrium for all reactions, and consider sorption on constant potential, rather than constant charge, surfaces. Reardon's (1981) seminal findings on the spatial and temporal variability of partitioning (of 90Sr) are reexamined and found partially caused by his assumption of a kinetically limited reaction. In the present work, sorption is assumed the predominant retardation process controlling Pu and Np transport, and is simulated using a diffuse-double-layer-surface-complexation (DDLSC) model. Transport simulations consider the infiltration of Np- and Pu-contaminated waters into an initially uncontaminated environment, followed by the cleanup of the resultant contamination with uncontaminated water. Simulations are conducted using different spatial distributions of sorption capacities (with the same total potential sorption capacity, but with different variances and spatial correlation structures). Results obtained differ markedly from those that would be obtained in transport simulations using constant Kd, Langmuir or Freundlich sorption models. When possible, simulation results (breakthrough curves) are fitted to a constant K d advection-dispersion transport model and compared. Functional differences often are great enough that they prevent a meaningful fit of the simulation results with a constant K d (or even a Langmuir or Freundlich) model, even in the case of Np, a weakly sorbed radionuclide under the simulation conditions. Functional behaviors that cannot be fit include concentration trend reversals and radionuclide desorption spikes. Other simulation results are fit successfully but the fitted parameters (Kd and dispersivity) vary significantly depending on simulation conditions (e.g. "infiltration" vs. "cleanup" conditions). Notably, an increase in the variance of the specified sorption capacities results in a marked increase in the dispersion of the radionuclides. The results presented have implications for the simulation of radionuclide migration in performance assessments of nuclear waste-disposal sites, for the future monitoring of those sites, and more generally for modeling contaminant transport in ground-water environments. ?? 2003 Published by Elsevier Science Ltd.

Tracing time scales of fluid residence and migration in the crust (Invited)

NASA Astrophysics Data System (ADS)

Yokochi, R.; Sturchio, N. C.; Purtschert, R.; Jiang, W.; Lu, Z.; Müller, P.; Yang, G.; Kennedy, B. M.

2013-12-01

Crustal fluids (water, gas and oil) mediate chemical reactions, and they may transport, concentrate or disperse elements in the crust; the fluids are often valuable resources in their own right. In this context, determining the time scales of fluid transport and residence time is essential for understanding geochemical cycle of elements, as well as risk and resource management. Crustal fluids contain stable and radioactive noble gases indigenous to the fluid, which may be of magmatic or atmospheric origin of various ages. In addition, radiogenic and nucleogenic noble gases (both stable and radioactive) are continuously produced by the decay of U, Th and K and related nuclear reactions in the crust at known rates and in known relative proportions. They may be released from their production sites and incorporated into the fluid, acting as natural spikes to trace fluid flow. The concentrations of a noble gas isotope in a crustal fluid in a system devoid of phase separation or mixing varies as a function of decay time and supply from the production sites into the fluids. The release rate of noble gases from the production sites in minerals to the fluid phase may be determined uniquely through the studies of noble gas radionuclides (Yokochi et al., 2012), which is fundamental to the behavior of volatile elements in geochemistry. A pilot study of noble gas radionuclides in an active geothermal system was performed at Yellowstone National Park (Yokochi et al., 2013). Prior studies of the Yellowstone system using stable noble gas isotopes show that the thermal fluids contain a mixture of atmospheric, mantle, and crustal components. Noble gas radionuclide measurements provide new chronometric constraints regarding the subsurface residence times of Yellowstone thermal fluids. Upper limits on deep thermal fluid mean residence times, estimated from 39Ar/40Ar* ratios, range from 118 to 137 kyr for features in the Gibbon and Norris Geyser Basin areas, and are about 16 kyr in Lower Geyser Basin, with the key assumption that the fluid acquires its crustal component of Ar in Quaternary volcanic rock of the Yellowstone caldera. Krypton-81 isotopic abundances in the gas samples yield upper limits on residence time that are consistent with those obtained from 39Ar/40Ar* ratios. Young fluid components can also be determined by krypton-85 concentrations in the extracted gases. Better understanding of the production mechanisms of noble-gas radionuclides in reservoir rocks would significantly decrease the uncertainties in modeling fluid residence times.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Boggs, S. Jr.; Livermore, D.; Seitz, M.G.

Dissolved humic substances (humic and fulvic acids) occur in surface waters and groundwaters in concentrations ranging from less than 1 mg(C)/L to more than 100 mg(C)/L. Humic substances are strong complexing agents for many trace metals in the environment and are also capable of forming stable soluble complexes or chelates with radionuclides. Concentrations of humic materials as low as 1 mg(C)/L can produce a detectable increase in the mobility of some actinide elements by forming soluble complexes that inhibit sorption of the radionuclides onto rock materials. The stability of trace metal- or radionuclide-organic complexes is commonly measured by an empiricallymore » determined conditional stability constant (K'), which is based on the ratio of complexed metal (radionuclide) in solution to the product concentration of uncomplexed metal and humic complexant. Larger values of stability constants indicate greater complex stability. The stability of radionuclide-organic complexes is affected both by concentration variables and envionmental factors. In general, complexing is favored by increased of radionuclide, increased pH, and decreased ionic strength. Actinide elements are generally most soluble in their higher oxidation states. Radionuclides can also form stable, insoluble complexes with humic materials that tend to reduce radionuclide mobility. These insoluble complexes may be radionuclide-humate colloids that subsequently precipitate from solution, or complexes of radionuclides and humic substances that sorb to clay minerals or other soil particulates strongly enough to immobilize the radionuclides. Colloid formation appears to be favored by increased radionuclide concentration and lowered pH; however, the conditions that favor formation of insoluble complexes that sorb to particulates are still poorly understood. 129 refs., 25 figs., 19 tabs.« less

TECHNOLOGIES FOR RADON AND RADIONUCLIDE REMOVAL

EPA Science Inventory

This paper provides a summary of the technologies that are currently being used to remove radionuclides from drinking water. The radionuclides that are featured are the radionuclides currently regulated by EPA; radium, radon and uranium. Tehnologies effective for removal of eac...

Lunar and Planetary Science XXXV: Origin of Planetary Systems

NASA Technical Reports Server (NTRS)

2004-01-01

The session titled Origin of Planetary Systems" included the following reports:Convective Cooling of Protoplanetary Disks and Rapid Giant Planet Formation; When Push Comes to Shove: Gap-opening, Disk Clearing and the In Situ Formation of Giant Planets; Late Injection of Radionuclides into Solar Nebula Analogs in Orion; Growth of Dust Particles and Accumulation of Centimeter-sized Objects in the Vicinity of a Pressure enhanced Region of a Solar Nebula; Fast, Repeatable Clumping of Solid Particles in Microgravity ; Chondrule Formation by Current Sheets in Protoplanetary Disks; Radial Migration of Phyllosilicates in the Solar Nebula; Accretion of the Outer Planets: Oligarchy or Monarchy?; Resonant Capture of Irregular Satellites by a Protoplanet ; On the Final Mass of Giant Planets ; Predicting the Atmospheric Composition of Extrasolar Giant Planets; Overturn of Unstably Stratified Fluids: Implications for the Early Evolution of Planetary Mantles; and The Evolution of an Impact-generated Partially-vaporized Circumplanetary Disk.

Geoscience parameter data base handbook: granites and basalts

DOE Office of Scientific and Technical Information (OSTI.GOV)

Not Available

1979-12-01

The Department of Energy has the responsibility for selecting and constructing Federal repositories for radioactive waste. The Nuclear Regulatory Commission must license such repositories prior to construction. The basic requirement in the geologic disposal of radioactive waste is stated as: placement in a geologic host whereby the radioactive waste is not in mechanical, thermal or chemical equilibrium with the object of preventing physical or chemical migration of radionuclides into the biosphere or hydrosphere in hazardous concentration (USGS, 1977). The object of this report is to document the known geologic parameters of large granite and basalt occurrences in the coterminous Unitedmore » States, for future evaluation in the selection and licensing of radioactive waste repositories. The description of the characteristics of certain potential igneous hosts has been limited to existing data pertaining to the general geologic character, geomechanics, and hydrology of identified occurrences. A description of the geochemistry is the subject of a separate report.« less

Hydrothermal transformations in an aluminophosphate glass matrix containing simulators of high-level radioactive wastes

NASA Astrophysics Data System (ADS)

Yudintsev, S. V.; Mal'kovsky, V. I.; Mokhov, A. V.

2016-05-01

The interaction of aluminophosphate glass with water at 95°C for 35 days results in glass heterogenization and in the appearance of a gel layer and various phases. The leaching rate of elements is low owing to the formation of a protective layer on the glass surface. It is shown that over 80% of uranium leached from the glass matrix occurs as colloids below 450 nm in size characterized by high migration ability in the geological environment. To determine the composition of these colloids is a primary task for further studies. Water vapor is a crystallization factor for glasses. The conditions as such may appear even at early stages of glass storage because of the failure of seals on containers of high-level radioactive wastes. The examination of water resistance of crystallized matrices and determination of the fraction of radionuclide in colloids are also subjects for further studies.

Modeling Cell and Tumor-Metastasis Dosimetry with the Particle and Heavy Ion Transport Code System (PHITS) Software for Targeted Alpha-Particle Radionuclide Therapy.

PubMed

Lee, Dongyoul; Li, Mengshi; Bednarz, Bryan; Schultz, Michael K

2018-06-26

The use of targeted radionuclide therapy for cancer is on the rise. While beta-particle-emitting radionuclides have been extensively explored for targeted radionuclide therapy, alpha-particle-emitting radionuclides are emerging as effective alternatives. In this context, fundamental understanding of the interactions and dosimetry of these emitted particles with cells in the tumor microenvironment is critical to ascertaining the potential of alpha-particle-emitting radionuclides. One important parameter that can be used to assess these metrics is the S-value. In this study, we characterized several alpha-particle-emitting radionuclides (and their associated radionuclide progeny) regarding S-values in the cellular and tumor-metastasis environments. The Particle and Heavy Ion Transport code System (PHITS) was used to obtain S-values via Monte Carlo simulation for cell and tumor metastasis resulting from interactions with the alpha-particle-emitting radionuclides, lead-212 ( 212 Pb), actinium-225 ( 225 Ac) and bismuth-213 ( 213 Bi); these values were compared to the beta-particle-emitting radionuclides yttrium-90 ( 90 Y) and lutetium-177 ( 177 Lu) and an Auger-electron-emitting radionuclide indium-111 ( 111 In). The effect of cellular internalization on S-value was explored at increasing degree of internalization for each radionuclide. This aspect of S-value determination was further explored in a cell line-specific fashion for six different cancer cell lines based on the cell dimensions obtained by confocal microscopy. S-values from PHITS were in good agreement with MIRDcell S-values (cellular S-values) and the values found by Hindié et al. (tumor S-values). In the cellular model, 212 Pb and 213 Bi decay series produced S-values that were 50- to 120-fold higher than 177 Lu, while 225 Ac decay series analysis suggested S-values that were 240- to 520-fold higher than 177 Lu. S-values arising with 100% cellular internalization were two- to sixfold higher for the nucleus when compared to 0% internalization. The tumor dosimetry model defines the relative merit of radionuclides and suggests alpha particles may be effective for large tumors as well as small tumor metastases. These results from PHITS modeling substantiate emerging evidence that alpha-particle-emitting radionuclides may be an effective alternative to beta-particle-emitting radionuclides for targeted radionuclide therapy due to preferred dose-deposition profiles in the cellular and tumor metastasis context. These results further suggest that internalization of alpha-particle-emitting radionuclides via radiolabeled ligands may increase the relative biological effectiveness of radiotherapeutics.

Emission, transport, deposition, and re-suspension of radionuclides from Fukushima Dai-ichi Nuclear Power Plant in the atmosphere - Overview of 2-year investigations in Japan

NASA Astrophysics Data System (ADS)

Kita, Kazuyuki; Igarashi, Yasuhiro; Yoshida, Naohiro; Nakajima, Teruyuki

2013-04-01

Following a huge earthquake and tsunami in Eastern Japan on 11 March, 2011, the accident in Fukushima Dai-ichi Nuclear Power Plant (FDNPP) occurred to emit a large amount of artificial radionuclides to the environment. Soon after the FDNPP accident, many Japanese researchers, as well as researchers in other countries, started monitoring radionuclides in various environmental fields and/or model calculations to understand extent and magnitude of radioactive pollution. In this presentation, we overview these activities for the atmospheric radionuclides in Japan as followings: 1. Investigations to evaluate radionuclide emissions by explosions at FNDPP in March 2011 and to estimate the respiration dose of the radiation at this stage. 2. Investigations to evaluate atmospheric transport and deposition processes of atmospheric radionuclide to determine the extent of radionuclide pollution. -- Based on results of the regular and urgent monitoring results, as well as the mapping of the distribution of radionuclide s accumulated by the deposition to the ground, restoration of their time-dependent emission rates has been tried, and processes determining atmospheric concentration and deposition to the ground have been investigated by using the model calculations. 3. Monitoring of the atmospheric concentrations of radionuclide after the initial, surge phase of FNDPP accident. 4. Investigations to evaluate re-suspension of radionuclide from the ground, including the soil and the vegetation. -- Intensive monitoring of the atmospheric concentrations and deposition amount of radionuclide after the initial, surge phase of the accident enable us to evaluate emission history from FNDPP, atmospheric transport and deposition processes, chemical and physical characteristics of atmospheric radionuclide especially of radio cesium, and re-suspension processes which has become dominant process to supply radio cesium to the atmosphere recently.

Radioecology

NASA Astrophysics Data System (ADS)

Steinnes, Eiliv

2007-11-01

Radioecology is the subject dealing with the behaviour of radioactive substances in nature and how they affect plants, animals, and humans. The text discusses radionuclides of natural origin and their doses to man, artificially produced radionuclides and their most important sources, pathways of radionuclides in the environment, and transfer of radionuclides in foodchains. The importance of chemical speciation on the mobility of radionuclides in radioecology is particularly emphasized. Some radioecological problems in Norway following the Chernobyl accident are briefly discussed.

Vertical distribution of 137Cs in grassland soils disturbed by moles (Talpa europaea L.).

PubMed

Ramzaev, V; Barkovsky, A

2018-04-01

Activity of biota is one of the factors influencing vertical migration of radionuclides deposited from the atmosphere onto the ground surface. The goal of this work was to study the vertical distribution of 137 Cs in grassland soils disturbed by moles (Talpa europaea L.) in comparison with undisturbed grassland soils. Field observations and soil sampling were carried out in the areas of eight settlements in the Klintsovskiy, Krasnogorskiy and Novozybkovskiy districts of the Bryansk region, Russia in six years during the period 1999-2016. The study sites had been heavily contaminated by Chernobyl fallout in 1986. Activity of 137 Cs in soil samples was determined by γ-ray spectrometry. 137 Cs surface ground contamination levels at the studied plots (n = 17) ranged from 327 kBq m -2 to 2360 kBq m -2 with a mean of 1000 kBq m -2 and a median of 700 kBq m -2 . The position of the 137 Cs migration centre in the soil in 2010-2016 was significantly (the Mann-Whitney U test, P < .01) deeper at mole-disturbed plots (median = 5.99 cm or 6.64 g cm -2 , n = 6) compared to the undisturbed ones (median = 2.48 cm or 2.35 g cm -2 , n = 6). The 137 Cs migration rate at mole-disturbed plots (median = 0.26 g cm -2  y -1 , mean = 0.31 g cm -2  y -1 ) was significantly higher (by a factor of 3) than at undisturbed plots (median = 0.08 g cm -2  y -1 , mean = 0.10 g cm -2  y -1 ). The difference in the migration rates between the mole-disturbed and undisturbed plots (median = 0.18 g cm -2  y -1 , mean = 0.21 g cm -2  y -1 ) reasonably corresponded to the mass of soil that might be ejected by moles per unit area per year. The results of this study indicate that the burrowing activity of moles has increased vertical migration of Chernobyl-derived radiocaesium in the grassland soils. Copyright © 2018 Elsevier Ltd. All rights reserved.

Radiation Doses to Members of the U.S. Population from Ubiquitous Radionuclides in the Body: Part 1, Autopsy and In Vivo Data

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, David J.; Strom, Daniel J.

This paper is part one of a three-part series investigating annual effective doses to residents of the United States from intakes of ubiquitous radionuclides, including radionuclides occurring naturally, radionuclides whose concentrations are technologically enhanced, and anthropogenic radionuclides. This series of papers explicitly excludes intakes from inhaling 222Rn, 220Rn, and their short-lived decay products; it also excludes intakes of radionuclides in occupational and medical settings. The goal of part one of this work was to review, summarize, and characterize all published and some unpublished data for U.S. residents on ubiquitous radionuclide concentrations in tissues and organs. Forty-five papers and reports weremore » obtained and their data reviewed, and three data sets were obtained via private communication. The 45 radionuclides of interest are the 238U series (14 nuclides), the actinium series (headed by 235U; 11 nuclides), and the 232Th series (11 nuclides); primordial radionuclides 87Rb and 40 K; cosmogenic and fallout radionuclides 14C and 3H; and purely anthropogenic radionuclides 137Cs-137mBa, 129I, and 90Sr-90Y. Measurements judged to be relevant were available for only 15 of these radionuclides: 238U, 235U, 234U, 232Th, 230Th, 228Th, 228Ra, 226Ra, 210Pb, 210Po, 137Cs, 87Rb, 40K, 14C, and 3H. Recent and relevant measurements were not available for 129I and 90Sr-90Y. A total of 11,714 radionuclide concentration measurements were found in one or more tissues or organs from 14 States. Data on age, sex, geographic locations, height, and weight of subjects were available only sporadically. Too often authors did not provide meaningful values of uncertainty of measurements so that variability in data sets is confounded with measurement uncertainty. The following papers detail how these shortcomings are overcome to achieve the goals of the three-part series.« less

Radionuclide deposition control

DOEpatents

Brehm, William F.; McGuire, Joseph C.

1980-01-01

The deposition of radionuclides manganese-54, cobalt-58 and cobalt-60 from liquid sodium coolant is controlled by providing surfaces of nickel or high nickel alloys to extract the radionuclides from the liquid sodium, and by providing surfaces of tungsten, molybdenum or tantalum to prevent or retard radionuclide deposition.

Behaviour and fluxes of natural radionuclides in the production process of a phosphoric acid plant.

PubMed

Bolívar, J P; Martín, J E; García-Tenorio, R; Pérez-Moreno, J P; Mas, J L

2009-02-01

In recent years there has been an increasing awareness of the occupational and public hazards of the radiological impact of non-nuclear industries which process materials containing naturally occurring radionuclides. These include the industries devoted to the production of phosphoric acid by treating sedimentary phosphate rocks enriched in radionuclides from the uranium series. With the aim of evaluating the radiological impact of a phosphoric acid factory located in the south-western Spain, the distribution and levels of radionuclides in the materials involved in its production process have been analysed. In this way, it is possible to asses the flows of radionuclides at each step and to locate those points where a possible radionuclide accumulation could be produced. A set of samples collected along the whole production process were analysed to determine their radionuclide content by both alpha-particle and gamma spectrometry techniques. The radionuclide fractionation steps and enrichment sources have been located, allowing the establishment of their mass (activity) balances per year.

Therapeutic radionuclides in nuclear medicine: current and future prospects

PubMed Central

Yeong, Chai-Hong; Cheng, Mu-hua; Ng, Kwan-Hoong

2014-01-01

The potential use of radionuclides in therapy has been recognized for many decades. A number of radionuclides, such as iodine-131 (131I), phosphorous-32 (32P), strontium-90 (90Sr), and yttrium-90 (90Y), have been used successfully for the treatment of many benign and malignant disorders. Recently, the rapid growth of this branch of nuclear medicine has been stimulated by the introduction of a number of new radionuclides and radiopharmaceuticals for the treatment of metastatic bone pain and neuroendocrine and other malignant or non-malignant tumours. Today, the field of radionuclide therapy is enjoying an exciting phase and is poised for greater growth and development in the coming years. For example, in Asia, the high prevalence of thyroid and liver diseases has prompted many novel developments and clinical trials using targeted radionuclide therapy. This paper reviews the characteristics and clinical applications of the commonly available therapeutic radionuclides, as well as the problems and issues involved in translating novel radionuclides into clinical therapies. PMID:25294374

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kautsky, Mark; Nguyen, Jason; Darr, Paul S.

The Long-Term Surveillance and Maintenance Plan (LTSMP) for Amchitka details how the U.S. Department of Energy (DOE) intends to fulfill its mission to maintain protection of human health and the environment at and around the sites on Amchitka Island. The LTSMP calls for monitoring to be performed every 5 years, at least in the initial phase of the project. The purpose of the monitoring is to develop a baseline of activity concentrations for selected radionuclides in biota, water, and soil, both on Amchitka and at the reference location on Adak Island, approximately 322 km (200 miles) northeast of Amchitka. Datamore » compiled by the Consortium for Risk Evaluation with Stakeholder Participation (CRESP, 2006) are being included as part of the baseline data set. The specific biological, water, and sediment samples collected during the 2011 sampling event were developed through close coordination with the primary stakeholders, including the Alaska Department of Environmental Conservation, the Aleutian Pribilof Island Association, and the U.S. Fish and Wildlife Service (USFWS). Amchitka is managed by the USFWS as part of the Alaska Maritime National Wildlife Refuge. Two plans were developed to address specific needs of the biological- and the terrestrial-monitoring programs. Results from these monitoring programs will help determine whether the environment is being impacted by radionuclide migration and uptake, and if subsistence and commercial-catch seafood is safe for human consumption. The RESRAD-BIOTA code is being used to evaluate ecological health relative to the radionuclide levels determined from this sampling event. The samples were sent to three laboratories for analysis. With the exception of the seawater samples, most of the samples were sent to the Center for Accelerator Mass Spectrometry at the Lawrence Livermore National Laboratory. A smaller subset of rock-weed samples, Star reindeer lichen samples, and soil samples collected from beneath the lichen were sent to UAF for cesium-137 analysis. Marine sediment samples were also collected and sent to UAF for testing. The seawater samples were sent to the University of Miami Tritium Laboratory for enriched tritium analysis. Results from the seawater samples for tritium were received in September 2011. Results from the 2011 sampling are expected to be available on the LM web site in 2012. (authors)« less

Meeting report from the Prostate Cancer Foundation PSMA-directed radionuclide scientific working group.

PubMed

Miyahira, Andrea K; Pienta, Kenneth J; Morris, Michael J; Bander, Neil H; Baum, Richard P; Fendler, Wolfgang P; Goeckeler, William; Gorin, Michael A; Hennekes, Hartwig; Pomper, Martin G; Sartor, Oliver; Tagawa, Scott T; Williams, Scott; Soule, Howard R

2018-05-01

The Prostate Cancer Foundation (PCF) convened a PSMA-Directed Radionuclide Scientific Working Group on November 14, 2017, at Weill Cornell Medicine, New York, NY. The meeting was attended by 35 global investigators with expertise in prostate cancer biology, radionuclide therapy, molecular imaging, prostate-specific membrane antigen (PSMA)-targeted agents, drug development, and prostate cancer clinical trials. The goal of this meeting was to discuss the potential for using PSMA-targeted radionuclide agents for the treatment of advanced prostate cancer and to define the studies and clinical trials necessary for validating and optimizing the use of these agents. Several major topic areas were discussed including the overview of PSMA biology, lessons and applications of PSMA-targeted PET imaging, the nuances of designing PSMA-targeted radionuclide agents, clinical experiences with PSMA-targeted radionuclides, PCF-funded projects to accelerate PSMA-targeted radionuclide therapy, and barriers to the use of radionuclide treatments in widespread clinical practice. This article reviews the major topics discussed at the meeting with the goal of promoting research that will validate and optimize the use of PSMA-targeted radionuclide therapies for the treatment of advanced prostate cancer. © 2018 Wiley Periodicals, Inc.

Radionuclide speciation in effluent from La Hague reprocessing plant in France.

PubMed

Salbu, B; Skipperud, L; Germain, P; Guéguéniat, P; Strand, P; Lind, O C; Christensen, G

2003-09-01

Effluent from the La Hague nuclear fuel reprocessing plant was mixed with seawater in order to investigate the fate of the various radionuclides. Thus, a major objective of the present work is to characterize the effluent from La Hague reprocessing plant and to study how the radionuclide speciation changes with time when discharged into the marine environment. Discharges from the La Hague nuclear reprocessing plant represent an important source of artificially produced radionuclides to the North Sea. The transport, distribution, and biological uptake of radionuclides in the marine environment depends, however, on the physicochemical forms of radionuclides in the discharged effluents and on transformation processes that occur after entering the coastal waters. Information of these processes is needed to understand the transport and long-term distribution of the radionuclides. In the present work, a weekly discharged effluent from the nuclear fuel reprocessing plant at Cap La Hague in France was mixed with coastal water and fractionated with respect to particle size and charged species using ultra centrifugation and hollow fiber ultrafiltration with on line ion exchange. The size distribution pattern of gamma-emitting radionuclides was followed during a 62-h period after mixing the effluent with seawater. 54Mn was present as particulate material in the effluent, while other investigated radionuclides were discharged in a more mobile form or were mobilized after mixing with sea water (e.g., 60Co) and can be transported long distances in the sea. Sediments can act as a sink for less mobile discharged radionuclides (Skipperud et al. 2000). A kinetic model experiment was performed to provide information of the time-dependent distribution coefficients, Kd (t). The retention of the effluent radionuclides in sediments was surprisingly low (Kd 20-50), and the sediments acted as a poor sink for the released radionuclides. Due to the presence of non-reacting radionuclide species in the effluent, a major fraction of the radionuclides, such as Cs-isotopes, 106Ru and 125Sb, in the effluent will be subjected to marine transport to the Northern Seas (i.e., the North Sea, Norwegian Sea and the Barents Sea). The La Hague effluent may, therefore, contribute to enriched levels of radionuclides found in the English Channel, including 90Sr, 60Co and Pu-isotopes, and also 106Ru and 125Sb.

Establishing a pre-mining geochemical baseline at a uranium mine near Grand Canyon National Park, USA

USGS Publications Warehouse

Naftz, David L.; Walton-Day, Katherine

2016-01-01

During 2012, approximately 404,000 ha of Federal Land in northern Arizona was withdrawn from consideration of mineral extraction for a 20-year period to protect the Grand Canyon watershed from potentially adverse effects of U mineral exploration and development. The development, operation, and reclamation of the Canyon Mine during the withdrawal period provide an excellent field site to understand and document off-site migration of radionuclides within the withdrawal area. As part of the Department of Interior's (DOI's) study plan for the exclusion area, the objective of our study is to utilize pre-defined decision units (DUs) in areas within and surrounding the Canyon Mine to demonstrate how newly established incremental sampling methodologies (ISM) combined with multivariate statistical methods can be used to document a repeatable and statistically defensible measure of pre-mining baseline conditions in surface soils and stream sediment samples prior to ore extraction. During the survey in June 2013, the highest pre-mining 95% upper confidence level (UCL) concentrations with respect to As, Mo, U, and V were found in the triplicate samples collected from surface soils in the mine site DU designated as M1. Gamma activities were slightly elevated in soils within the M1 DU (up to 28 μR/h); however, off-site gamma activities in soil and stream-sediment samples were lower (< 6 to 12 μR/h). Hierarchical cluster analysis (HCA) was applied to 33 chemical constituents contained in the multivariate data generated from the analysis of triplicate samples collected in the soil and stream sediment DUs within and surrounding Canyon Mine. Most of the triplicate samples from individual DUs were grouped in the same dendrogram cluster when using a similarity value (SV) of 0.70 (unitless). Different group membership of triplicate samples from two of the four haul road DUs was likely the result of heterogeneity induced by non-native soil material introduced from the gravel road base or from vehicular traffic. Application of HCA and ISM will provide critical metrics to meet DOI's long-term goals for assessing off-site migration of radionuclides resulting from mining and reclamation in the current (2015) exclusion area associated within the Grand Canyon watershed and the associated national park.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Paton, Ian

The Rocky Flats Environmental Technology Site (RFETS) is a Department of Energy facility located approximately 16 miles northwest of Denver, Colorado. Processing and fabrication of nuclear weapons components occurred at Rocky Flats from 1952 through 1989. Operations at the Site included the use of several radionuclides, including plutonium-239/240 (Pu), americium-241 (Am), and various uranium (U) isotopes, as well as several types of chlorinated solvents. The historic operations resulted in legacy contamination, including contaminated facilities, process waste lines, buried wastes and surface soil contamination. Decontamination and removal of buildings at the site was completed in late 2005, culminating more than tenmore » years of active environmental remediation work. The Corrective Action Decision/Record of Decision was subsequently approved in 2006, signifying regulatory approval and closure of the site. The use of RFETS as a National Wildlife Refuge is scheduled to be in full operation by 2012. To develop a plan for remediating different types of radionuclide contaminants present in the RFETS environment required understanding the different environmental transport pathways for the various actinides. Developing this understanding was the primary objective of the Actinide Migration Evaluation (AME) project. Findings from the AME studies were used in the development of RFETS remediation strategies. The AME project focused on issues of actinide behavior and mobility in surface water, groundwater, air, soil and biota at RFETS. For the purposes of the AME studies, actinide elements addressed included Pu, Am, and U. The AME program, funded by DOE, brought together personnel with a broad range of relevant expertise in technical investigations. The AME advisory panel identified research investigations and approaches that could be used to solve issues related to actinide migration at the Site. An initial step of the AME was to develop a conceptual model to provide a qualitative description of the relationships among potential actinide sources and transport pathways at RFETS. One conceptual model was developed specifically for plutonium and americium, because of their similar geochemical and transport properties. A separate model was developed for uranium because of its different properties and mobility in the environment. These conceptual models were guidelines for quantitative analyses described in the RFETS Pathway Analysis Report, which used existing data from the literature as well as site-specific analyses, including field, laboratory and modeling studies to provide quantitative estimates of actinide migration in the RFETS environment. For pathways where more than one method was used to estimate offsite loads for a specific pathway, the method yielding the highest estimated off-site was used for comparison purposes. For all actinides studied, for pre-remediation conditions, air and surface water were identified to be the dominant transport mechanisms. The estimated annual airborne plutonium-239/240 load transported off site exceeded the surface water load by roughly a factor of 40. However, despite being the largest transport pathway, airborne radionuclide concentrations at the monitoring location with the highest measurements during the period studied were less than two percent of the allowable 10 milli-rem standard governing DOE facilities. Estimated actinide loads for other pathways were much less. Shallow groundwater was approximately two orders of magnitude lower, or 1/100 of the load conveyed in surface water. The estimated biological pathway load for plutonium was approximately five orders of magnitude less, or 1/100,000, of the load estimated for surface-water. The pathway analysis results were taken into consideration during subsequent remediation activities that occurred at the site. For example, when the 903 Pad area was remediated to address elevated concentrations of Pu and Am in the surface soil, portable tent structures were constructed to prevent wind and water erosion from occurring while remediation activities took place. Following remediation of the 903 Pad and surrounding area, coconut erosion blankets were installed to mitigate erosion effects while vegetation was reestablished [2]. These measures were effective tools to address the primary transport mechanisms identified, coupling the scientific understanding of the site with the remediation strategy.« less

Radionuclide removal by apatite

DOE PAGES

Rigali, Mark J.; Brady, Patrick V.; Moore, Robert C.

2016-12-01

In this study, a growing body of research supports widespread future reliance on apatite for radioactive waste cleanup. Apatite is a multi-functional radionuclide sorbent that lowers dissolved radionuclide concentrations by surface sorption, ion exchange, surface precipitation, and by providing phosphate to precipitate low-solubility radionuclide-containing minerals. Natural apatites are rich in trace elements, and apatite’s stability in the geologic record suggest that radionuclides incorporated into apatite, whether in a permeable reactive barrier or a waste form, are likely to remain isolated from the biosphere for long periods of time. Here we outline the mineralogic and surface origins of apatite-radionuclide reactivity andmore » show how apatites might be used to environmental advantage in the future.« less

Adsorption of radionuclides on the monolayer MoS2

NASA Astrophysics Data System (ADS)

Zhao, Qiang; Zhang, Zheng; Ouyang, Xiaoping

2018-04-01

How to remove radionuclides from radioactive wastewater has long been a difficult problem, especially in nuclear accidents. In this paper, the adsorption of radionuclides Cs, Sr, and Ba on the monolayer MoS2 was investigated by using the first principles calculation method. Through the calculation of adsorption energy and Hirshfeld charge of the radionuclides on the monolayer MoS2 at six adsorption sites, the results show that all of the radionuclides chemisorbed on the monolayer MoS2, and the adsorption strength of these three kinds of radionuclides on the monolayer MoS2 is Ba > Sr > Cs. This work might shed some light on the treatment of the radioactive wastewater.

A Coincidence Signature Library for Multicoincidence Radionuclide Analysis Systems

DOE Office of Scientific and Technical Information (OSTI.GOV)

Smith, Leon E.; Ellis, J E.; Valsan, Andrei B.

Pacific Northwest National Laboratory (PNNL) is currently developing multicoincidence systems to perform trace radionuclide analysis at or near the sample collection point, for applications that include emergency response, nuclear forensics, and environmental monitoring. Quantifying radionuclide concentrations with these systems requires a library of accurate emission intensities for each detected signature, for all candidate radionuclides. To meet this need, a Coincidence Lookup Library (CLL) is being developed to calculate the emission intensities of coincident signatures from a user-specified radionuclide, or conversely, to determine the radionuclides that may be responsible for a specific detected coincident signature. The algorithms used to generate absolutemore » emission intensities and various query modes for our developmental CLL are described.« less

A Preliminary Performance Assessment for Salt Disposal of High-Level Nuclear Waste - 12173

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lee, Joon H.; Clayton, Daniel; Jove-Colon, Carlos

2012-07-01

A salt repository is one of the four geologic media currently under study by the U.S. DOE Office of Nuclear Energy to support the development of a long-term strategy for geologic disposal of commercial used nuclear fuel (UNF) and high-level radioactive waste (HLW). The immediate goal of the generic salt repository study is to develop the necessary modeling tools to evaluate and improve the understanding of the repository system response and processes relevant to long-term disposal of UNF and HLW in a salt formation. The current phase of this study considers representative geologic settings and features adopted from previous studiesmore » for salt repository sites. For the reference scenario, the brine flow rates in the repository and underlying interbeds are very low, and transport of radionuclides in the transport pathways is dominated by diffusion and greatly retarded by sorption on the interbed filling materials. I-129 is the dominant annual dose contributor at the hypothetical accessible environment, but the calculated mean annual dose is negligibly small. For the human intrusion (or disturbed) scenario, the mean mass release rate and mean annual dose histories are very different from those for the reference scenario. Actinides including Pu-239, Pu-242 and Np-237 are major annual dose contributors, and the calculated peak mean annual dose is acceptably low. A performance assessment model for a generic salt repository has been developed incorporating, where applicable, representative geologic settings and features adopted from literature data for salt repository sites. The conceptual model and scenario for radionuclide release and transport from a salt repository were developed utilizing literature data. The salt GDS model was developed in a probabilistic analysis framework. The preliminary performance analysis for demonstration of model capability is for an isothermal condition at the ambient temperature for the near field. The capability demonstration emphasizes key attributes of a salt repository that are potentially important to the long-term safe disposal of UNF and HLW. The analysis presents and discusses the results showing repository responses to different radionuclide release scenarios (undisturbed and human intrusion). For the reference (or nominal or undisturbed) scenario, the brine flow rates in the repository and underlying interbeds are very low, and transport of radionuclides in the transport pathways is dominated by diffusion and greatly retarded by sorption on the interbed filling materials. I-129 (non-sorbing and unlimited solubility with a very long half-life) is the dominant annual dose contributor at the hypothetical accessible environment, but the calculated mean annual dose is negligibly small that there is no meaningful consequence for the repository performance. For the human intrusion (or disturbed) scenario analysis, the mean mass release rate and mean annual dose histories are very different from those for the reference scenario analysis. Compared to the reference scenario, the relative annual dose contributions by soluble, non-sorbing fission products, particularly I-129, are much lower than by actinides including Pu-239, Pu-242 and Np-237. The lower relative mean annual dose contributions by the fission product radionuclides are due to their lower total inventory available for release (i.e., up to five affected waste packages), and the higher mean annual doses by the actinides are the outcome of the direct release of the radionuclides into the overlying aquifer having high water flow rates, thereby resulting in an early arrival of higher concentrations of the radionuclides at the biosphere drinking water well prior to their significant decay. The salt GDS model analysis has also identified the following future recommendations and/or knowledge gaps to improve and enhance the confidence of the future repository performance analysis. - Repository thermal loading by UNF and HLW, and the effect on the engineered barrier and near-field performance. - Closure and consolidation of salt rocks by creep deformation under the influence of thermal perturbation, and the effect on the engineered barrier and near-field performance. - Brine migration and radionuclide transport under the influence of thermal perturbation in generic salt repository environment, and the effect on the engineered barrier and near-field performance and far-field performance. - Near-field geochemistry and radionuclide mobility in generic salt repository environment (high ionic strength brines, elevated temperatures and chemically reducing condition). - Degradation of engineer barrier components (waste package, waste canister, waste forms, etc.) in a generic salt repository environment (high ionic strength brines, elevated temperatures and chemically reducing condition). - Waste stream types and inventory estimates, particularly for reprocessing high-level waste. (authors)« less

Chemistry of diagenetically altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Broxton, D.E.; Warren, R.G.; Hagan, R.C.

1986-10-01

The chemistry of diagenetically altered tuffs at a potential nuclear waste repository, Yucca Mountain, Nevada is described. These tuffs contain substantial amounts of zeolites that are highly sorptive of certain radionuclides. Because of their widespread distribution, the zeolitic tuffs could provide important barriers to radionuclide migration. Physical properties of these tuffs and of their constituent zeolites are influenced by their chemical compositions. This study defines the amount of chemical variability within diagenetically altered tuffs and within diagenetic minerals at Yucca Mountain. Zeolitic tuffs at Yucca Mountain formed by diagenetic alteration of rhyolitic vitric tuffs. Despite their similar starting compositions, thesemore » tuffs developed compositions that vary both vertically and laterally. Widespread chemical variations were the result of open-system chemical diagenesis in which chemical components of the tuffs were mobilized and redistributed by groundwaters. Alkalies, alkaline earths, and silica were the most mobile elements during diagenesis. The zeolitic tuffs can be divided into three compositional groups: (1) calcium- and magnesium-rich tuffs associated with relatively thin zones of alteration in the unsaturated zone; (2) tuffs in thick zones of alteration at and below the water table that grade laterally from sodic compositions on the western side of Yucca Mountain to calcic compositions on the eastern side; and (3) potassic tuffs at the north end of Yucca Mountain. Physical properties of tuffs and their consistuent zeolites at Yucca Mountain may be affected by variations in compositions. Properties important for assessment of repository performance include behavior and ion exchange.« less

Subsurface Xenon Migration by Atmospheric Pumping Using an Implicit Non-Iterative Algorithm for a Locally 1D Dual-Porosity Model

NASA Astrophysics Data System (ADS)

Annewandter, R.; Kalinowksi, M. B.

2009-04-01

An underground nuclear explosion injects radionuclids in the surrounding host rock creating an initial radionuclid distribution. In the case of fractured permeable media, cyclical changes in atmospheric pressure can draw gaseous species upwards to the surface, establishing a ratcheting pump effect. The resulting advective transport is orders of magnitude more significant than transport by molecular diffusion. In the 1990s the US Department of Energy funded the socalled Non-Proliferation Experiment conducted by the Lawrence Livermore National Laboratory to investigate this barometric pumping effect for verifying compliance with respect to the Comprehensive Nuclear Test Ban Treaty. A chemical explosive of approximately 1 kt TNT-equivalent has been detonated in a cavity located 390 m deep in the Rainier Mesa (Nevada Test Site) in which two tracer gases were emplaced. Within this experiment SF6 was first detected in soil gas samples taken near fault zones after 50 days and 3He after 325 days. For this paper a locally one-dimensional dual-porosity model for flow along the fracture and within the permeable matrix was used after Nilson and Lie (1990). Seepage of gases and diffusion of tracers between fracture and matrix are accounted. The advective flow along the fracture and within the matrix block is based on the FRAM filtering remedy and methodology of Chapman. The resulting system of equations is solved by an implicit non-iterative algorithm. Results on time of arrival and subsurface concentration levels for the CTBT-relevant xenons will be presented.

Soil gas 222Rn concentration in northern Germany and its relationship with geological subsurface structures.

PubMed

Künze, N; Koroleva, M; Reuther, C-D

2013-01-01

(222)Rn in soil gas activity was measured across the margins of two active salt diapirs in Schleswig-Holstein, northern Germany, in order to reveal the impact of halokinetic processes on the soil gas signal. Soil gas and soil sampling were carried out in springtime and summer 2011. The occurrence of elevated (222)Rn in soil gas concentrations in Schleswig-Holstein has been ascribed to radionuclide rich moraine boulder material deposits, but the contribution of subsurface structures has not been investigated so far. Reference samples were taken from a region known for its granitic moraine boulder deposits, resulting in (222)Rn in soil gas activity of 40 kBq/m(3). The values resulting from profile sampling across salt dome margins are of the order of twice the moraine boulder material reference values and exceed 100 kBq/m(3). The zones of elevated concentrations are consistent throughout time despite variations in magnitude. One soil gas profile recorded in this work expands parallel to a seismic profile and reveals multiple zones of elevated (222)Rn activities above a rising salt intrusion. The physical and chemical properties of salt have an impact on the processes influencing gas migration and surface near radionuclide accumulations. The rise of salt supports the breakup of rock components thus leading to enhanced emanation. This work provides a first approach regarding the halokinetic contribution to the (222)Rn in soil gas occurrence and a possible theoretical model which summarizes the relevant processes was developed. Copyright © 2012 Elsevier Ltd. All rights reserved.

210Pb, 137Cs and 7Be in the sediments of coastal lakes on the polish coast: Implications for sedimentary processes.

PubMed

Woszczyk, Michał; Poręba, Grzegorz; Malinowski, Łukasz

2017-04-01

In this study we combined radioisotopes ( 210 Pb, 137 Cs and 7 Be) and hydrodynamic modeling to investigate sedimentary processes in three coastal lakes on the Polish Baltic coast. The research aimed at establishing the depth of sediment mixing and its effects on sediment geochemistry as well as showing the relationship between lake water salinity and radionuclide distribution in the sediment cores. We established that the intensity of mixing displayed appreciable variability throughout the lakes and the thickness of sediment mixing layer was between <2 and 22 cm. The mixing was primarily due to wind-induced waves. The vertical mixing was shown to shift sulfidation of the sediments towards deeper layers. We found that the distributions of radioisotopes, 137 Cs in particular, in the sediment cores from coastal lakes were strongly affected by the early diagenetic processes, which caused diffusive migration of radionuclides. The inventories of 210 Pb ex and 137 Cs in the lakes were positively related to salinity. The high inventories of both isotopes (3.2-10.9 kBq ·m -2 for 210 Pb ex and 3.0-6.0 kBq·m -2 for 137 Cs) in coastal lakes were explained by enhanced sedimentation within estuarine mixing zone and delivery of "additional" 210 Pb and 137 Cs to the lakes during saltwater ingressions. The results of this study have implications for the paleolimnology, sedimentology and biogeochemistry of coastal lakes. Copyright © 2017 Elsevier Ltd. All rights reserved.

Radiological risk assessment and biosphere modelling for radioactive waste disposal in Switzerland.

PubMed

Brennwald, M S; van Dorp, F

2009-12-01

Long-term safety assessments for geological disposal of radioactive waste in Switzerland involve the demonstration that the annual radiation dose to humans due to the potential release of radionuclides from the waste repository into the biosphere will not exceed the regulatory limit of 0.1 mSv. Here, we describe the simple but robust approach used by Nagra (Swiss National Cooperative for the Disposal of Radioactive Waste) to quantify the dose to humans as a result to time-dependent release of radionuclides from the geosphere into the biosphere. The model calculates the concentrations of radionuclides in different terrestrial and aquatic compartments of the surface environment. The fluxes of water and solids within the environment are the drivers for the exchange of radionuclides between these compartments. The calculated radionuclide concentrations in the biosphere are then used to estimate the radiation doses to humans due to various exposure paths (e.g. ingestion of radionuclides via drinking water and food, inhalation of radionuclides, external irradiation from radionuclides in soils). In this paper we also discuss recent new achievements and planned future work.

Airborne radionuclides in the proglacial environment as indicators of sources and transfers of soil material.

PubMed

Łokas, Edyta; Wachniew, Przemysław; Jodłowski, Paweł; Gąsiorek, Michał

2017-11-01

A survey of artificial ( 137 Cs, 238 Pu, 239+240 Pu, 241 Am) and natural ( 226 Ra, 232 Th, 40 K, 210 Pb) radioactive isotopes in proglacial soils of an Arctic glacier have revealed high spatial variability of activity concentrations and inventories of the airborne radionuclides. Soil column 137 Cs inventories range from below the detection limit to nearly 120 kBq m -2 , this value significantly exceeding direct atmospheric deposition. This variability may result from the mixing of materials characterised by different contents of airborne radionuclides. The highest activity concentrations observed in the proglacial soils may result from the deposition of cryoconites, which have been shown to accumulate airborne radionuclides on the surface of glaciers. The role of cryoconites in radionuclide accumulation is supported by the concordant enrichment of the naturally occurring airborne 210 Pb in proglacial soil cores showing elevated levels of artificial radionuclides. The lithogenic radionuclides show less variability than the airborne radionuclides because their activity concentrations are controlled only by the mixing of material derived from the weathering of different parent rocks. Soil properties vary little within and between the profiles and there is no unequivocal relationship between them and the radionuclide contents. The inventories reflect the pathways and time variable inputs of soil material to particular sites of the proglacial zone. Lack of the airborne radionuclides reflects no deposition of material exposed to the atmosphere after the 1950s or its removal by erosion. Inventories above the direct atmospheric deposition indicate secondary deposition of radionuclide-bearing material. Very high inventories indicate sites where transport pathways of cryoconite material terminated. Copyright © 2017 Elsevier Ltd. All rights reserved.

The study of equivalent dose of uranium in long bean (V. U. Sesquipedalis) and the effect on human

NASA Astrophysics Data System (ADS)

Rashid, Nur Shahidah Abdul; Yoshandi, Tengku Mohammad; Majid, Sukiman Sarmania Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

2016-01-01

In the case of accidental release of Uranium-238 (238U) radionuclides in a nuclear facility or in the environment, internal contamination by either acute or chronic exposure has the potential to induce both radiological and chemical toxic effects. A study was conducted to estimate the 238U radionuclide concentration in the long beans using Induced Coupled Mass Plasma-Spectrometry (ICP-MS). 238U radionuclide is a naturally occurring radioactive material that can be found in soil and can be transferred to the long bean (Vigna unguiculata subsp. Sesquapedalis) directly or indirectly via water or air. Kidney and liver are the major sites of deposition of 238U radionuclide. The obtained dose exposed in the liver and kidney is used to assess the safety level for public intake of 238U radionuclide from the consumption of long beans. The concentration of 238U radionuclide measured in long bean samples was 0.0226 ± 0.0009 mg/kg. Total activity of 238U radionuclide was 0.0044 ± 0.0002 Bq/day with the daily intake of 0.3545 ± 0.0143 µg/day and the annual committed effective dose due to ingestion of 238U radionuclide in long beans was 0.2230 ± 0.0087 µSv/year. The committed equivalent dose of 238U radionuclide from the assessment in the liver and kidney are 0.4198 ± 0.0165 nSv and 10.9335 ± 0.4288 nSv. The risk of cancer of 238U radionuclide was determined to be (86.0466 ± 3.3748) × 10-9. Thus, the results concluded that 238U radionuclide in local long beans was in the permitted level and safe to consume without posing any significant radiological threat to population.

Reliability of Current Biokinetic and Dosimetric Models for Radionuclides: A Pilot Study

DOE Office of Scientific and Technical Information (OSTI.GOV)

Leggett, Richard Wayne; Eckerman, Keith F; Meck, Robert A.

2008-10-01

This report describes the results of a pilot study of the reliability of the biokinetic and dosimetric models currently used by the U.S. Nuclear Regulatory Commission (NRC) as predictors of dose per unit internal or external exposure to radionuclides. The study examines the feasibility of critically evaluating the accuracy of these models for a comprehensive set of radionuclides of concern to the NRC. Each critical evaluation would include: identification of discrepancies between the models and current databases; characterization of uncertainties in model predictions of dose per unit intake or unit external exposure; characterization of variability in dose per unit intakemore » or unit external exposure; and evaluation of prospects for development of more accurate models. Uncertainty refers here to the level of knowledge of a central value for a population, and variability refers to quantitative differences between different members of a population. This pilot study provides a critical assessment of models for selected radionuclides representing different levels of knowledge of dose per unit exposure. The main conclusions of this study are as follows: (1) To optimize the use of available NRC resources, the full study should focus on radionuclides most frequently encountered in the workplace or environment. A list of 50 radionuclides is proposed. (2) The reliability of a dose coefficient for inhalation or ingestion of a radionuclide (i.e., an estimate of dose per unit intake) may depend strongly on the specific application. Multiple characterizations of the uncertainty in a dose coefficient for inhalation or ingestion of a radionuclide may be needed for different forms of the radionuclide and different levels of information of that form available to the dose analyst. (3) A meaningful characterization of variability in dose per unit intake of a radionuclide requires detailed information on the biokinetics of the radionuclide and hence is not feasible for many infrequently studied radionuclides. (4) The biokinetics of a radionuclide in the human body typically represents the greatest source of uncertainty or variability in dose per unit intake. (5) Characterization of uncertainty in dose per unit exposure is generally a more straightforward problem for external exposure than for intake of a radionuclide. (6) For many radionuclides the most important outcome of a large-scale critical evaluation of databases and biokinetic models for radionuclides is expected to be the improvement of current models. Many of the current models do not fully or accurately reflect available radiobiological or physiological information, either because the models are outdated or because they were based on selective or uncritical use of data or inadequate model structures. In such cases the models should be replaced with physiologically realistic models that incorporate a wider spectrum of information.« less

Measurement of radionuclides in waste packages

DOEpatents

Brodzinski, R.L.; Perkins, R.W.; Rieck, H.G.; Wogman, N.A.

1984-09-12

A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

Measurement of radionuclides in waste packages

DOEpatents

Brodzinski, Ronald L.; Perkins, Richard W.; Rieck, Henry G.; Wogman, Ned A.

1986-01-01

A method is described for non-destructively assaying the radionuclide content of solid waste in a sealed container by analysis of the waste's gamma-ray spectrum and neutron emissions. Some radionuclides are measured by characteristic photopeaks in the gamma-ray spectrum; transuranic nuclides are measured by neutron emission rate; other radionuclides are measured by correlation with those already measured.

Mobile detection system to evaluate reactive hyperemia using radionuclide plethysmography.

PubMed

Harel, François; Ngo, Quam; Finnerty, Vincent; Hernandez, Edgar; Khairy, Paul; Dupuis, Jocelyn

2007-08-01

We validated a novel mobile detection system to evaluate reactive hyperemia using the radionuclide plethysmography technique. Twenty-six subjects underwent simultaneously radionuclide plethysmography with strain gauge plethysmography. Strain gauge and radionuclide methods showed excellent reproducibility with intraclass correlation coefficients of 0.96 and 0.89 respectively. There was also a good correlation of flows between the two methods during reactive hyperemia (r = 0.87). We conclude that radionuclide plethysmography using this mobile detection system is a non-invasive alternative to assess forearm blood flow and its dynamic variations during reactive hyperemia.

Characteristics of radionuclide contamination of different zones of Semipalatinsk Nuclear Test Site ``Opytnoe pole''

NASA Astrophysics Data System (ADS)

Kadyrzhanov, K. K.; Khazhekber, S.; Lukashenko, S. N.; Solodukhin, V. P.; Kazachevskiy, I. V.; Poznyak, V. L.; Knyazev, B. B.; Rofer, Ch.

2003-01-01

Data on the spatial distribution of radionuclides (241Am, 239Pu, 137Cs and 152Eu) formed during nuclear explosions of different types near P2 SNTS test site are presented. Radionuclide contamination induced by the explosions varies in the concentrations of individual radionuclides, their proportions and species. Examination of the variations is a crucial task to plan remediation activities as well as those aimed at decrease of radiation risk for population and prevention of repeated contamination. Concentrations of 241Am and 239+240Pu that are the most toxic radionuclides in the area lie in hundred thousands of Bqkg-1. The most contaminated areas are classified by the radionuclide concentration, ratio and form present in soil.

Radionuclides in drinking water: the recent legislative requirements of the European Union.

PubMed

Grande, Sveva; Risica, Serena

2015-03-01

In November 2013, a new EURATOM Directive was issued on the protection of public health from the radionuclide content in drinking water. After introducing the contents of the Directive, the paper analyses the hypotheses about drinking water ingestion adopted in documents of international and national organizations and the data obtained from national/regional surveys. Starting from the Directive's parametric value for the Indicative Dose, some examples of derived activity concentrations of radionuclides in drinking water are reported for some age classes and three exposure situations, namely, (i) artificial radionuclides due to routine water release from nuclear power facilities, (ii) artificial radionuclides from nuclear medicine procedures, and (iii) naturally occurring radionuclides in drinking water or resulting from existing or past NORM industrial activities.

Radionuclide labeled lymphocytes for therapeutic use

DOEpatents

Srivastava, Suresh C.; Fawwaz, Rashid A.; Richards, Powell

1985-01-01

Lymphocytes labelled with .beta.-emitting radionuclides are therapeutically useful, particularly for lymphoid ablation. They are prepared by incubation of the lymphocytes with the selected radionuclide-oxine complex.

Radionuclide labeled lymphocytes for therapeutic use

DOEpatents

Srivastava, S.C.; Fawwaz, R.A.; Richards, P.

1983-05-03

Lymphocytes labelled with ..beta..-emitting radionuclides are therapeutically useful, particularly for lymphoid ablation. They are prepared by incubation of the lymphocytes with the selected radionuclide-oxine complex.

Analysis of fission and activation radionuclides produced by a uranium-fueled nuclear detonation and identification of the top dose-producing radionuclides.

PubMed

Kraus, Terry; Foster, Kevin

2014-08-01

The radiological assessment of the nuclear fallout (i.e., fission and neutron-activation radionuclides) from a nuclear detonation is complicated by the large number of fallout radionuclides. This paper provides the initial isotopic source term inventory of the fallout from a uranium-fueled nuclear detonation and identifies the significant and insignificant radiological dose producing radionuclides over 11 dose integration time periods (time phases) of interest. A primary goal of this work is to produce a set of consistent, time phase-dependent lists of the top dose-producing radionuclides that can be used to prepare radiological assessment calculations and data products (e.g., maps of areas that exceed protective action guidelines) in support of public and worker protection decisions. The ranked lists of top dose-producing radionuclides enable assessors to perform atmospheric dispersion modeling and radiological dose assessment modeling more quickly by using relatively short lists of radionuclides without significantly compromising the accuracy of the modeling and the dose projections. This paper also provides a superset-list of the top dose-producing fallout radionuclides from a uranium-fueled nuclear detonation that can be used to perform radiological assessments over any desired time phase. Furthermore, this paper provides information that may be useful to monitoring and sampling and laboratory analysis personnel to help understand which radionuclides are of primary concern. Finally, this paper may be useful to public protection decision makers because it shows the importance of quickly initiating public protection actions to minimize the radiological dose from fallout.

ARRONAX, a high-energy and high-intensity cyclotron for nuclear medicine.

PubMed

Haddad, Ferid; Ferrer, Ludovic; Guertin, Arnaud; Carlier, Thomas; Michel, Nathalie; Barbet, Jacques; Chatal, Jean-François

2008-07-01

This study was aimed at establishing a list of radionuclides of interest for nuclear medicine that can be produced in a high-intensity and high-energy cyclotron. We have considered both therapeutic and positron emission tomography radionuclides that can be produced using a high-energy and a high-intensity cyclotron such as ARRONAX, which will be operating in Nantes (France) by the end of 2008. Novel radionuclides or radionuclides of current limited availability have been selected according to the following criteria: emission of positrons, low-energy beta or alpha particles, stable or short half-life daughters, half-life between 3 h and 10 days or generator-produced, favourable dosimetry, production from stable isotopes with reasonable cross sections. Three radionuclides appear well suited to targeted radionuclide therapy using beta ((67)Cu, (47)Sc) or alpha ((211)At) particles. Positron emitters allowing dosimetry studies prior to radionuclide therapy ((64)Cu, (124)I, (44)Sc), or that can be generator-produced ((82)Rb, (68)Ga) or providing the opportunity of a new imaging modality ((44)Sc) are considered to have a great interest at short term whereas (86)Y, (52)Fe, (55)Co, (76)Br or (89)Zr are considered to have a potential interest at middle term. Several radionuclides not currently used in routine nuclear medicine or not available in sufficient amount for clinical research have been selected for future production. High-energy, high-intensity cyclotrons are necessary to produce some of the selected radionuclides and make possible future clinical developments in nuclear medicine. Associated with appropriate carriers, these radionuclides will respond to a maximum of unmet clinical needs.

Radionuclides in radiation-induced bystander effect; may it share in radionuclide therapy?

PubMed

Widel, M

2017-01-01

For many years in radiobiology and radiotherapy predominated the conviction that cellular DNA is the main target for ionizing radiation, however, the view has changed in the past 20 years. Nowadays, it is assumed that not only directed (targeted) radiation effect, but also an indirect (non-targeted) effect may contribute to the result of radiation treatment. Non-targeted effect is relatively well recognized after external beam irradiation in vitro and in vivo, and comprises such phenomena like radiation-induced bystander effect (RIBE), genomic instability, adaptive response and abscopal (out of field) effect. These stress-induced and molecular signaling mediated phenomena appear in non-targeted cells as variety responses resembling that observed in directly hit cells. Bystander effects can be both detrimental and beneficial in dependence on dose, dose-rate, cell type, genetic status and experimental condition. Less is known about radionuclide-induced non-targeted effects in radionuclide therapy, although, based on characteristics of the radionuclide radiation, on experiments in vitro utilizing classical and 3-D cell cultures, and preclinical study on animals it seems obvious that exposure to radionuclide is accompanied by various bystander effects, mostly damaging, less often protective. This review summarizes existing data on radionuclide induced bystander effects comprising radionuclides emitting beta- and alpha-particles and Auger electrons used in tumor radiotherapy and diagnostics. So far, separation of the direct effect of radionuclide decay from crossfire and bystander effects in clinical targeted radionuclide therapy is impossible because of the lack of methods to assess whether, and to what extent bystander effect is involved in human organism. Considerations on this topic are also included.

Solubility of 238U radionuclide from various types of soil in synthetic gastrointestinal fluids using "US in vitro" digestion method

NASA Astrophysics Data System (ADS)

Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.; Mohamed, Faizal; Siong, Khoo Kok

2015-04-01

238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by "US P in vitro" digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different values due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 - 0.209 ppm) than gastrointestinal fluids (0.024 - 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.

Radionuclides: Accumulation and Transport in Plants.

PubMed

Gupta, D K; Chatterjee, S; Datta, S; Voronina, A V; Walther, C

Application of radioactive elements or radionuclides for anthropogenic use is a widespread phenomenon nowadays. Radionuclides undergo radioactive decays releasing ionizing radiation like gamma ray(s) and/or alpha or beta particles that can displace electrons in the living matter (like in DNA) and disturb its function. Radionuclides are highly hazardous pollutants of considerable impact on the environment, food chain and human health. Cleaning up of the contaminated environment through plants is a promising technology where the rhizosphere may play an important role. Plants belonging to the families of Brassicaceae, Papilionaceae, Caryophyllaceae, Poaceae, and Asteraceae are most important in this respect and offer the largest potential for heavy metal phytoremediation. Plants like Lactuca sativa L., Silybum marianum Gaertn., Centaurea cyanus L., Carthamus tinctorius L., Helianthus annuus and H. tuberosus are also important plants for heavy metal phytoremediation. However, transfer factors (TF) of radionuclide from soil/water to plant ([Radionuclide]plant/[Radionuclide]soil) vary widely in different plants. Rhizosphere, rhizobacteria and varied metal transporters like NRAMP, ZIP families CDF, ATPases (HMAs) family like P1B-ATPases, are involved in the radio-phytoremediation processes. This review will discuss recent advancements and potential application of plants for radionuclide removal from the environment.

Chemical fractionation of radionuclides and stable elements in aquatic plants of the Yenisei River.

PubMed

Bolsunovsky, Alexander

2011-09-01

The Yenisei River is contaminated with artificial radionuclides released by one of the Russian nuclear plants. The aquatic plants growing in the radioactively contaminated parts of the river contain artificial radionuclides. The aim of the study was to investigate accumulation of artificial radionuclides and stable elements by submerged plants of the Yenisei River and estimate the strength of their binding to plant biomass by using a new sequential extraction scheme. The aquatic plants sampled were: Potamogeton lucens, Fontinalis antipyretica, and Batrachium kauffmanii. Gamma-spectrometric analysis of the samples of aquatic plants has revealed more than 20 radionuclides. We also investigated the chemical fractionation of radionuclides and stable elements in the biomass and rated radionuclides and stable elements based on their distribution in biomass. The greatest number of radionuclides strongly bound to biomass cell structures was found for Potamogeton lucens and the smallest for Batrachium kauffmanii. For Fontinalis antipyretica, the number of distribution patterns that were similar for both radioactive isotopes and their stable counterparts was greater than for the other studied species. The transuranic elements (239)Np and (241)Am were found in the intracellular fraction of the biomass, and this suggested their active accumulation by the plants.

137Cs and 90Sr IN lizards of Semipalatinsk test site.

PubMed

Panitskiy, А V; Lukashenko, S N; Kadyrova, N Zh

2017-01-01

The paper provides research results of 137 Cs and 90 Sr radionuclides concentrations in bodies of Lacertidae family lizards, inhabiting different parts of Semipalatinsk Test Site, and the parameters of these radionuclides' transfer into lizards' bodies. It shows that high activity concentration of radionuclides in lizards' bodies can be noticed if they live directly at locally contaminated areas. Since the distance from contaminated spots exceeds home range of the studied animals, no increased values of radionuclides' activity were found in the animal bodies. At some individual radioactively contaminated spots, very high activity concentrations of 90 Sr radionuclide up to 7.8 × 10 5  Bq kg -1 were found in lizards. So under certain conditions, lizards can significantly contribute to radionuclides redistribution in the natural environment. Mean concentration ratios (CR) of radionuclides were as follows: 137 Cs-6.2 × 10 -3 , 90 Sr-1.1 × 10 -2 . Copyright © 2016 Elsevier Ltd. All rights reserved.

Reactor-Produced Medical Radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mirzadeh, Saed; Mausner, Leonard; Garland, Marc A

2011-01-01

The therapeutic use of radionuclides in nuclear medicine, oncology and cardiology is the most rapidly growing use of medical radionuclides. Since most therapeutic radionuclides are neutron rich and decay by beta emission, they are reactor-produced. This chapter deals mainly with production approaches with neutrons. Neutron interactions with matter, neutron transmission and activation rates, and neutron spectra of nuclear reactors are discussed in some detail. Further, a short discussion of the neutron-energy dependence of cross sections, reaction rates in thermal reactors, cross section measurements and flux monitoring, and general equations governing the reactor production of radionuclides are presented. Finally, the chaptermore » is concluded by providing a number of examples encompassing the various possible reaction routes for production of a number of medical radionuclides in a reactor.« less

Redistribution of fallout radionuclides in Enewetak Atoll lagoon sediments by callianassid bioturbation.

PubMed

McMurtry, G M; Schneider, R C; Colin, P L; Buddemeier, R W; Suchanek, T H

The lagoon sediments of Enewetak Atoll in the Marshall Islands contain a large selection of fallout radionuclides as a result of 43 nuclear weapon tests conducted there between 1948 and 1958. Studies of the burial of fallout radionuclides have been conducted on the islands and in several of the large craters, but studies of their vertical distribution have been limited to about the upper 20 cm of the lagoon sediments. We have found elevated fallout radionuclide concentrations buried more deeply in the lagoon sediments and evidence of burrowing into the sediment by several species of callianassid ghost shrimp (Crustacea: Thalassinidea) which has displaced highly radioactive sediment. The burrowing activities of callianassids, which are ubiquitous on the lagoon floor, facilitate radionuclide redistribution and complicate the fallout radionuclide inventory of the lagoon.

Detecting low levels of radionuclides in fluids

DOEpatents

Patch, Keith D.; Morgan, Dean T.

2000-01-01

An apparatus and method for detecting low levels of one or more radionuclides in a fluid sample uses a substrate that includes an ion exchange resin or other sorbent material to collect the radionuclides. A collecting apparatus includes a collecting chamber that exposes the substrate to a measured amount of the fluid sample such that radionuclides in the fluid sample are collected by the ion exchange resin. A drying apparatus, which can include a drying chamber, then dries the substrate. A measuring apparatus measures emissions from radionuclides collected on the substrate. The substrate is positioned in a measuring chamber proximate to a detector, which provides a signal in response to emissions from the radionuclides. Other analysis methods can be used to detect non-radioactive analytes, which can be collected with other types of sorbent materials.

Seven years of radionuclide laboratory at IMC - important achievements.

PubMed

Hrubý, M; Kučka, J; Pánek, J; Štěpánek, P

2016-10-20

For many important research topics in polymer science the use of radionuclides brings significant benefits concerning nanotechnology, polymer drug delivery systems, tissue engineering etc. This contribution describes important achievements of the radionuclide laboratory at Institute of Macromolecular Chemistry of the Academy of Sciences of the Czech Republic (IMC) in the area of polymers for biomedical applications. Particular emphasis will be given to water-soluble polymer carriers of radionuclides, thermoresponsive polymer radionuclide carriers, thermoresponsive polymers for local brachytherapy, polymer scaffolds modified with (radiolabeled) peptides and polymer copper chelators for the therapy of Wilson´s disease.

Radioisotope Detection Device and Methods of Radioisotope Collection

DOEpatents

Tranter, Troy J [Idaho Falls, ID; Oertel, Christopher P [Idaho Falls, ID; Giles, John R [Pocatello, ID; Mann, Nicholas R [Rigby, ID; McIlwain, Michael E [Idaho Falls, ID

2011-04-12

A device for collection of radionuclides includes a mixture of a polymer, a fluorescent organic scintillator and a chemical extractant. A radionuclide detector system includes a collection device comprising a mixture of a polymer, a fluorescent agent and a selective ligand. The system includes at least one photomultiplier tube (PMT). A method of detecting radionuclides includes providing a collector device comprising a mixture comprising a polymer, a fluorescent organic scintillator and a chemical extractant. An aqueous environment is exposed to the device and radionuclides are collected from the environment. Radionuclides can be concentrated within the device.

Ensemble Simulation of the Atmospheric Radionuclides Discharged by the Fukushima Nuclear Accident

NASA Astrophysics Data System (ADS)

Sekiyama, Thomas; Kajino, Mizuo; Kunii, Masaru

2013-04-01

Enormous amounts of radionuclides were discharged into the atmosphere by a nuclear accident at the Fukushima Daiichi nuclear power plant (FDNPP) after the earthquake and tsunami on 11 March 2011. The radionuclides were dispersed from the power plant and deposited mainly over eastern Japan and the North Pacific Ocean. A lot of numerical simulations of the radionuclide dispersion and deposition had been attempted repeatedly since the nuclear accident. However, none of them were able to perfectly simulate the distribution of dose rates observed after the accident over eastern Japan. This was partly due to the error of the wind vectors and precipitations used in the numerical simulations; unfortunately, their deterministic simulations could not deal with the probability distribution of the simulation results and errors. Therefore, an ensemble simulation of the atmospheric radionuclides was performed using the ensemble Kalman filter (EnKF) data assimilation system coupled with the Japan Meteorological Agency (JMA) non-hydrostatic mesoscale model (NHM); this mesoscale model has been used operationally for daily weather forecasts by JMA. Meteorological observations were provided to the EnKF data assimilation system from the JMA operational-weather-forecast dataset. Through this ensemble data assimilation, twenty members of the meteorological analysis over eastern Japan from 11 to 31 March 2011 were successfully obtained. Using these meteorological ensemble analysis members, the radionuclide behavior in the atmosphere such as advection, convection, diffusion, dry deposition, and wet deposition was simulated. This ensemble simulation provided the multiple results of the radionuclide dispersion and distribution. Because a large ensemble deviation indicates the low accuracy of the numerical simulation, the probabilistic information is obtainable from the ensemble simulation results. For example, the uncertainty of precipitation triggered the uncertainty of wet deposition; the uncertainty of wet deposition triggered the uncertainty of atmospheric radionuclide amounts. Then the remained radionuclides were transported downwind; consequently the uncertainty signal of the radionuclide amounts was propagated downwind. The signal propagation was seen in the ensemble simulation by the tracking of the large deviation areas of radionuclide concentration and deposition. These statistics are able to provide information useful for the probabilistic prediction of radionuclides.

The study of equivalent dose of uranium in long bean (V. U. Sesquipedalis) and the effect on human

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rashid, Nur Shahidah Abdul; Yoshandi, Tengku Mohammad; Majid, Sukiman Sarmania Amran Ab.

In the case of accidental release of Uranium-238 ({sup 238}U) radionuclides in a nuclear facility or in the environment, internal contamination by either acute or chronic exposure has the potential to induce both radiological and chemical toxic effects. A study was conducted to estimate the {sup 238}U radionuclide concentration in the long beans using Induced Coupled Mass Plasma-Spectrometry (ICP-MS). {sup 238}U radionuclide is a naturally occurring radioactive material that can be found in soil and can be transferred to the long bean (Vigna unguiculata subsp. Sesquapedalis) directly or indirectly via water or air. Kidney and liver are the major sitesmore » of deposition of {sup 238}U radionuclide. The obtained dose exposed in the liver and kidney is used to assess the safety level for public intake of {sup 238}U radionuclide from the consumption of long beans. The concentration of {sup 238}U radionuclide measured in long bean samples was 0.0226 ± 0.0009 mg/kg. Total activity of {sup 238}U radionuclide was 0.0044 ± 0.0002 Bq/day with the daily intake of 0.3545 ± 0.0143 µg/day and the annual committed effective dose due to ingestion of {sup 238}U radionuclide in long beans was 0.2230 ± 0.0087 µSv/year. The committed equivalent dose of {sup 238}U radionuclide from the assessment in the liver and kidney are 0.4198 ± 0.0165 nSv and 10.9335 ± 0.4288 nSv. The risk of cancer of {sup 238}U radionuclide was determined to be (86.0466 ± 3.3748) × 10-9. Thus, the results concluded that {sup 238}U radionuclide in local long beans was in the permitted level and safe to consume without posing any significant radiological threat to population.« less

The saturated zone at Yucca Mountain: An overview of the characterization and assessment of the saturated zone as a barrier to potential radionuclide migration

USGS Publications Warehouse

Eddebbarh, A.-A.; Zyvoloski, G.A.; Robinson, B.A.; Kwicklis, E.M.; Reimus, P.W.; Arnold, B.W.; Corbet, T.; Kuzio, S.P.; Faunt, C.

2003-01-01

The US Department of Energy is pursuing Yucca Mountain, Nevada, for the development of a geologic repository for the disposal of spent nuclear fuel and high-level radioactive waste, if the repository is able to meet applicable radiation protection standards established by the US Nuclear Regulatory Commission and the US Environmental Protection Agency (EPA). Effective performance of such a repository would rely on a number of natural and engineered barriers to isolate radioactive waste from the accessible environment. Groundwater beneath Yucca Mountain is the primary medium through which most radionuclides might move away from the potential repository. The saturated zone (SZ) system is expected to act as a natural barrier to this possible movement of radionuclides both by delaying their transport and by reducing their concentration before they reach the accessible environment. Information obtained from Yucca Mountain Site Characterization Project activities is used to estimate groundwater flow rates through the site-scale SZ flow and transport model area and to constrain general conceptual models of groundwater flow in the site-scale area. The site-scale conceptual model is a synthesis of what is known about flow and transport processes at the scale required for total system performance assessment of the site. This knowledge builds on and is consistent with knowledge that has accumulated at the regional scale but is more detailed because more data are available at the site-scale level. The mathematical basis of the site-scale model and the associated numerical approaches are designed to assist in quantifying the uncertainty in the permeability of rocks in the geologic framework model and to represent accurately the flow and transport processes included in the site-scale conceptual model. Confidence in the results of the mathematical model was obtained by comparing calculated to observed hydraulic heads, estimated to measured permeabilities, and lateral flow rates calculated by the site-scale model to those calculated by the regional-scale flow model. In addition, it was confirmed that the flow paths leaving the region of the potential repository are consistent with those inferred from gradients of measured head and those independently inferred from water-chemistry data. The general approach of the site-scale SZ flow and transport model analysis is to calculate unit breakthrough curves for radionuclides at the interface between the SZ and the biosphere using the three-dimensional site-scale SZ flow and transport model. Uncertainties are explicitly incorporated into the site-scale SZ flow and transport abstractions through key parameters and conceptual models. ?? 2002 Elsevier Science B.V. All rights reserved.

A survey of natural terrestrial and airborne radionuclides in moss samples from the peninsular Thailand.

PubMed

Wattanavatee, Komrit; Krmar, Miodrag; Bhongsuwan, Tripob

2017-10-01

The aim of this study was to determine the activity concentrations of natural terrestrial radionuclides ( 238 U, 226 Ra, 232 Th and 40 K) and airborne radionuclides ( 210 Pb, 210 Pb ex and 7 Be) in natural terrestrial mosses. The collected moss samples (46) representing 17 species were collected from 17 sampling localities in the National Parks and Wildlife Sanctuaries of Thailand, situated in the mountainous areas between the northern and the southern ends of peninsular Thailand (∼7-12 °N, 99-102 °E). Activity concentrations of radionuclides in the samples were measured using a low background gamma spectrometer. The results revealed non-uniform spatial distributions of all the radionuclides in the study area. Principal component analysis and cluster analysis revealed two distinct origins for the studied radionuclides, and furthermore, the Pearson correlations were strong within 226 Ra, 232 Th, 238 U and 40 K as well as within 210 Pb and 210 Pb ex , but there was no significant correlation between these two groups. Also 7 Be was uncorrelated to the others, as expected due to different origins of the airborne and terrestrial radionuclides. The radionuclide activities of moss samples varied by moss species, topography, geology, and meteorology of each sampling area. The observed abnormally high concentrations of some radionuclides probably indicate that the concentrations of airborne and terrestrial radionuclides in moss samples were directly related to local geological features of the sampling site, or that high levels of 7 Be were most probably linked with topography and regional NE monsoonal winds from mainland China. Copyright © 2017 Elsevier Ltd. All rights reserved.

Dynamics and transformations of radionuclides in soils and ecosystem health

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fellows, Robert J.; Ainsworth, Calvin C.; Driver, Crystal J.

1998-12-01

The chemical behavior of radionuclides can vary widely in soil and sediment environments. Equally important, for a given radionuclide the physico-chemical properties of the solids and aqueous phase can greatly influence a radionuclides behavior. Radionuclides can conceivably occur in soils as soluble-free, inorganic-soluble-complexed, organic-soluble, complexed, adsorbed, precipitated, coprecipitated, or solid structural species. While it is clear that an assessment of a radionuclide?s soil chemistry and potential shifts in speciation will yield a considerable understanding of its behavior in the natural environment, it does not directly translate to bioavailability or its impact on ecosystems health. The soil chemical factors have tomore » be linked to food chain considerations and other ecological parameters that directly tie to an analysis of ecosystem health. In general, the movement of radionuclides from lower to higher trophic levels diminishes with each trophic level in both aqua tic and terrestrial systems. In some cases, transfer is limited because of low absorption/assimilation by successive trophic organisms (Pu, U); for other radionuclides (Tc, H) assimilation may be high but rapid metabolic turnover and low retention greatly reduce tissue concentrations available to predator species. Still others are chemical analogs of essential elements whose concentrations are maintained under strict metabolic control in tissues (Cs) or are stored in tissues seldom consumed by other organisms (Sr storage in exoskeleton, shells, and bone). Therefore, the organisms that receive the greatest ingestion exposures are those in lower trophic positions or are in higher trophic levels but within simple, short food chains. Food source, behavior, and habitat influence the accumulation of radionuclides in animals.« less

Radiological bioconcentration factors for aquatic, terrestrial, and wetland ecosystems at the Savannah River Site

DOE Office of Scientific and Technical Information (OSTI.GOV)

Cummins, C.L.

As a result of operations at the Savannah River Site (SRS), over 50 radionuclides have been released to the atmosphere and to onsite streams and seepage basins. Now, many of these radionuclides are available to aquatic and/or terrestrial organisms for uptake and cycling through the food chain. Knowledge about the uptake and cycling of these radionuclides is now crucial in evaluating waste management and clean-up alternatives for the site. Numerous studies have been conducted at the SRS over the past forty years to study the uptake and distribution of radionuclides in the Savannah River Site environment. In many instances, bioconcentrationmore » factors have been calculated to quantify the uptake of a radionuclide by an organism from the surrounding medium (i.e., soil or water). In the past, it has been common practice to use bioconcentration factors from the literature because site-specific data were not readily available. However, because of the variability of bioconcentration factors due to experimental or environmental conditions, site-specific data should be used when available. This report compiles and summarizes site-specific bioconcentration factors for selected radionuclides released at the Savannah River Site (SRS). An extensive literature search yielded site-specific bioconcentration factors for cesium, strontium, cobalt, plutonium, americium, curium, and tritium. These eight radionuclides have been the primary radionuclides studied at SRS because of their long half lives or because they are major contributors to radiological dose from exposure. For most radionuclides, it was determined that the site-specific bioconcentration factors were higher than those reported in literature. This report also summarizes some conditions that affect radionuclide bioavailability to and bioconcentration by aquatic and terrestrial organisms.« less

Radionuclide Therapies in Molecular Imaging and Precision Medicine.

PubMed

Kendi, A Tuba; Moncayo, Valeria M; Nye, Jonathon A; Galt, James R; Halkar, Raghuveer; Schuster, David M

2017-01-01

This article reviews recent advances and applications of radionuclide therapy. Individualized precision medicine, new treatments, and the evolving role of radionuclide therapy are discussed. Copyright © 2016 Elsevier Inc. All rights reserved.

Electrocardiograph-gated single photon emission computed tomography radionuclide angiography presents good interstudy reproducibility for the quantification of global systolic right ventricular function.

PubMed

Daou, Doumit; Coaguila, Carlos; Vilain, Didier

2007-05-01

Electrocardiograph-gated single photon emission computed tomography (SPECT) radionuclide angiography provides accurate measurement of right ventricular ejection fraction and end-diastolic and end-systolic volumes. In this study, we report the interstudy precision and reliability of SPECT radionuclide angiography for the measurement of global systolic right ventricular function using two, three-dimensional volume processing methods (SPECT-QBS, SPECT-35%). These were compared with equilibrium planar radionuclide angiography. Ten patients with chronic coronary artery disease having two SPECT and planar radionuclide angiography acquisitions were included. For the right ventricular ejection fraction, end-diastolic volume and end-systolic volume, the interstudy precision and reliability were better with SPECT-35% than with SPECT-QBS. The sample sizes needed to objectify a change in right ventricular volumes or ejection fraction were lower with SPECT-35% than with SPECT-QBS. The interstudy precision and reliability of SPECT-35% and SPECT-QBS for the right ventricle were better than those of equilibrium planar radionuclide angiography, but poorer than those previously reported for the left ventricle with SPECT radionuclide angiography on the same population. SPECT-35% and SPECT-QBS present good interstudy precision and reliability for right ventricular function, with the results favouring the use of SPECT-35%. The results are better than those of equilibrium planar radionuclide angiography, but poorer than those previously reported for the left ventricle with SPECT radionuclide angiography. They need to be confirmed in a larger population.

Method for preparing radionuclide-labeled chelating agent-ligand complexes

DOEpatents

Meares, Claude F.; Li, Min; DeNardo, Sally J.

1999-01-01

Radionuclide-labeled chelating agent-ligand complexes that are useful in medical diagnosis or therapy are prepared by reacting a radionuclide, such as .sup.90 Y or .sup.111 In, with a polyfunctional chelating agent to form a radionuclide chelate that is electrically neutral; purifying the chelate by anion exchange chromatography; and reacting the purified chelate with a targeting molecule, such as a monoclonal antibody, to form the complex.

Microbial stabilization and mass reduction of wastes containing radionuclides and toxic metals

DOEpatents

Francis, A.J.; Dodge, C.J.; Gillow, J.B.

1991-09-10

A process is provided to treat wastes containing radionuclides and toxic metals with Clostridium sp. BFGl to release a large fraction of the waste solids into solution and convert the radionuclides and toxic metals to a more concentrated and stable form with concurrent volume and mass reduction. The radionuclides and toxic metals being in a more stable form are available for recovery, recycling and disposal. 18 figures.

Microbial stabilization and mass reduction of wastes containing radionuclides and toxic metals

DOEpatents

Francis, Arokiasamy J.; Dodge, Cleveland J.; Gillow, Jeffrey B.

1991-01-01

A process is provided to treat wastes containing radionuclides and toxic metals with Clostridium sp. BFGl to release a large fraction of the waste solids into solutin and convert the radionuclides and toxic metals to a more concentrated and stable form with concurrent volume and mass reduction. The radionuclides and toxic metals being in a more stable form are available for recovery, recycling and disposal.

Characteristics of Chernobyl-derived radionuclides in particulate form in surface waters in the exclusion zone around the Chernobyl Nuclear Power Plant

NASA Astrophysics Data System (ADS)

Matsunaga, Takeshi; Ueno, Takashi; Amano, Hikaru; Tkatchenko, Y.; Kovalyov, A.; Watanabe, Miki; Onuma, Yoshikazu

1998-12-01

The distribution of Chernobyl-derived radionuclides in river and lake water bodies at 6-40 km from the Chernobyl Nuclear Power Plant was studied. Current levels of radionuclides (Cesium-137, Strontium-90, Plutonium, Americium and Curium isotopes) in water bodies and their relation to the ground contamination are presented. The investigation of the radionuclide composition of aqueous and ground contamination revealed that radionuclides on suspended solids (particulate form) originate mainly from the erosion of the contaminated surface soil layer in the zone. Apparent distribution ratios between particulate and dissolved forms are compared to known distribution coefficients.

Soil-soil solution distribution coefficient of soil organic matter is a key factor for that of radioiodide in surface and subsurface soils.

PubMed

Unno, Yusuke; Tsukada, Hirofumi; Takeda, Akira; Takaku, Yuichi; Hisamatsu, Shun'ichi

2017-04-01

We investigated the vertical distribution of the soil-soil-solution distribution coefficients (K d ) of 125 I, 137 Cs, and 85 Sr in organic-rich surface soil and organic-poor subsurface soil of a pasture and an urban forest near a spent-nuclear-fuel reprocessing plant in Rokkasho, Japan. K d of 137 Cs was highly correlated with water-extractable K + . K d of 85 Sr was highly correlated with water-extractable Ca 2+ and SOC. K d of 125 I - was low in organic-rich surface soil, high slightly below the surface, and lowest in the deepest soil. This kinked distribution pattern differed from the gradual decrease of the other radionuclides. The thickness of the high- 125 I - K d middle layer (i.e., with high radioiodide retention ability) differed between sites. K d of 125 I - was significantly correlated with K d of soil organic carbon. Our results also showed that the layer thickness is controlled by the ratio of K d -OC between surface and subsurface soils. This finding suggests that the addition of SOC might prevent further radioiodide migration down the soil profile. As far as we know, this is the first report to show a strong correlation of a soil characteristic with K d of 125 I - . Further study is needed to clarify how radioiodide is retained and migrates in soil. Copyright © 2017 Elsevier Ltd. All rights reserved.

40 CFR Appendix D to Part 61 - Methods for Estimating Radionuclide Emissions

Code of Federal Regulations, 2011 CFR

2011-07-01

... Table 1. Table 1—Adjustment to Emission Factors for Effluent Controls Controls Types of radionuclides... applicable to gaseous radionuclides; periodic testing is prudent to ensure high removal efficiency. Fabric...

40 CFR Appendix D to Part 61 - Methods for Estimating Radionuclide Emissions

Code of Federal Regulations, 2013 CFR

2013-07-01

... Table 1. Table 1—Adjustment to Emission Factors for Effluent Controls Controls Types of radionuclides... applicable to gaseous radionuclides; periodic testing is prudent to ensure high removal efficiency. Fabric...

Conditions and processes affecting radionuclide transport

USGS Publications Warehouse

Simmons, Ardyth M.; Neymark, Leonid A.

2012-01-01

Understanding of unsaturated-zone transport is based on laboratory and field-scale experiments. Fractures provide advective transport pathways. Sorption and matrix diffusion may contribute to retardation of radionuclides. Conversely, sorption onto mobile colloids may enhance radionuclide transport.

Accumulation of radionuclides in bed sediments of the Columbia River between Hanford reactors and McNary Dam

USGS Publications Warehouse

Nelson, Jack L.; Haushild, W.L.

1970-01-01

Amounts of radionuclides from the Hanford reactors contained in bed sediments of the Columbia River were estimated by two methods: (1) from data on radionuclide concentration for the bed sediments between the reactors and McNary Dam, and (2) from data on radionuclide discharge for river stations at Pasco, Washington, and Umatilla, Oregon. Umatilla is 3.2 kilometers below McNary Dam. Accumulations of radionuclides in the Pasco to Umatilla reach estimated by the two methods agree within about 8%. In October 1965 approximately 16,000 curies of gamma emitting radionuclides were resident in bed sediments of the river between the Hanford reactors and McNary Dam. Concentrations and accumulations of chromium-51, zinc-65, cobalt-60, manganese-54, and scandium-46 generally are much higher near McNary Dam than they are in the vicinity of the reactors. These changes are caused by an increase downstream from the reactors in the proportion of the bed sediment that is fine grained and the proportions of the transported zinc, cobalt, manganese, and scandium radionuclides associated with sediment particles.

Radioactivity and the environment: technical approaches to understand the role of arbuscular mycorrhizal plants in radionuclide bioaccumulation

PubMed Central

Davies, Helena S.; Cox, Filipa; Robinson, Clare H.; Pittman, Jon K.

2015-01-01

Phytoaccumulation of radionuclides is of significant interest with regards to monitoring radionuclide build-up in food chains, developing methods for environmental bioremediation and for ecological management. There are many gaps in our understanding of the characteristics and mechanisms of plant radionuclide accumulation, including the importance of symbiotically-associated arbuscular mycorrhizal (AM) fungi. We first briefly review the evidence that demonstrates the ability of AM fungi to enhance the translocation of 238U into plant root tissues, and how fungal association may prevent further mobilization into shoot tissues. We then focus on approaches that should further advance our knowledge of AM fungi–plant radionuclide accumulation. Current research has mostly used artificial cultivation methods and we consider how more ecologically-relevant analysis might be performed. The use of synchrotron-based X-ray fluorescence imaging and absorption spectroscopy techniques to understand the mechanisms of radionuclide transfer from soil to plant via AM fungi is evaluated. Without such further knowledge, the behavior and mobilization of radionuclides cannot be accurately modeled and the potential risks cannot be accurately predicted. PMID:26284096

Radioactivity and the environment: technical approaches to understand the role of arbuscular mycorrhizal plants in radionuclide bioaccumulation.

PubMed

Davies, Helena S; Cox, Filipa; Robinson, Clare H; Pittman, Jon K

2015-01-01

Phytoaccumulation of radionuclides is of significant interest with regards to monitoring radionuclide build-up in food chains, developing methods for environmental bioremediation and for ecological management. There are many gaps in our understanding of the characteristics and mechanisms of plant radionuclide accumulation, including the importance of symbiotically-associated arbuscular mycorrhizal (AM) fungi. We first briefly review the evidence that demonstrates the ability of AM fungi to enhance the translocation of (238)U into plant root tissues, and how fungal association may prevent further mobilization into shoot tissues. We then focus on approaches that should further advance our knowledge of AM fungi-plant radionuclide accumulation. Current research has mostly used artificial cultivation methods and we consider how more ecologically-relevant analysis might be performed. The use of synchrotron-based X-ray fluorescence imaging and absorption spectroscopy techniques to understand the mechanisms of radionuclide transfer from soil to plant via AM fungi is evaluated. Without such further knowledge, the behavior and mobilization of radionuclides cannot be accurately modeled and the potential risks cannot be accurately predicted.

IMS radionuclide monitoring after the announced nuclear test of the DPRK on 3 September 2017

NASA Astrophysics Data System (ADS)

Kusmierczyk-Michulec, J.; Kalinowski, M.; Bourgouin, P.; Boxue, L.; Gheddou, A.; Klingberg, F.; Leppaenen, A. P.; Schoeppner, M.; Werzi, R.; Wang, J.

2017-12-01

The International Monitoring System (IMS) developed by the Comprehensive Nuclear-Test-Ban Treaty Organization (CTBTO) is a global system of monitoring stations, using four complementary technologies: seismic, hydroacoustic, infrasound and radionuclide. The radionuclide network comprises 80 stations, out of which 40 are to be equipped with noble gas systems. The aim of radionuclide stations is a global monitoring of radioactive aerosols, radioactive noble gases and atmospheric transport modelling (ATM). To investigate the transport of radionuclide emissions, the Provisional Technical Secretariat (PTS) operates an Atmospheric Transport Modelling (ATM) system based on the Lagrangian Particle Dispersion Model FLEXPART. The air mass trajectory provides a "link" between a radionuclide release and a detection confirmed by radionuclide measurements. The aim of this study is to demonstrate the RN analysis and the application of ATM to investigate the episodes of elevated levels of radioxenon observed by IMS stations after the sixth nuclear test, announced by the Democratic People's Republic of Korea (DPRK) at the Punggye-ri Nuclear Test Site on 3 September 2017. A comparison to the previous tests will be presented.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Rashid, Nur Shahidah Abdul; Sarmani, Sukiman; Majid, Amran Ab.

238U radionuclide is a naturally occuring radioactive material that can be found in soil. In this study, the solubility of 238U radionuclide obtained from various types of soil in synthetic gastrointestinal fluids was analysed by “US P in vitro” digestion method. The synthetic gastrointestinal fluids were added to the samples with well-ordered, mixed throughly and incubated according to the human physiology digestive system. The concentration of 238U radionuclide in the solutions extracted from the soil was measured using Induced Coupling Plasma Mass Spectrometer (ICP-MS). The concentration of 238U radionuclide from the soil samples in synthetic gastrointestinal fluids showed different valuesmore » due to different homogenity of soil types and chemical reaction of 238U radionuclide. In general, the solubility of 238U radionuclide in gastric fluid was higher (0.050 – 0.209 ppm) than gastrointestinal fluids (0.024 – 0.050 ppm). It could be concluded that the US P in vitro digestion method is practicle for estimating the solubility of 238U radionuclide from soil materials and could be useful for monitoring and risk assessment purposes applying to environmental, health and contaminated soil samples.« less

49 CFR 173.433 - Requirements for determining basic radionuclide values, and for the listing of radionuclides on...

Code of Federal Regulations, 2014 CFR

2014-10-01

... § 173.435 or § 173.436 or for which no relevant data are available: (1) the radionuclide values in... package must satisfy: ER26JA04.001 Where: B(i) is the activity of radionuclide i in special form; and A1... activity which may be transported in a Type A package must satisfy: ER26JA04.002 Where: C(j) is the...

Nanoparticles as multimodal photon transducers of ionizing radiation

NASA Astrophysics Data System (ADS)

Pratt, Edwin C.; Shaffer, Travis M.; Zhang, Qize; Drain, Charles Michael; Grimm, Jan

2018-05-01

In biomedical imaging, nanoparticles combined with radionuclides that generate Cerenkov luminescence are used in diagnostic imaging, photon-induced therapies and as activatable probes. In these applications, the nanoparticle is often viewed as a carrier inert to ionizing radiation from the radionuclide. However, certain phenomena such as enhanced nanoparticle luminescence and generation of reactive oxygen species cannot be completely explained by Cerenkov luminescence interactions with nanoparticles. Herein, we report methods to examine the mechanisms of nanoparticle excitation by radionuclides, including interactions with Cerenkov luminescence, β particles and γ radiation. We demonstrate that β-scintillation contributes appreciably to excitation and reactivity in certain nanoparticle systems, and that excitation by radionuclides of nanoparticles composed of large atomic number atoms generates X-rays, enabling multiplexed imaging through single photon emission computed tomography. These findings demonstrate practical optical imaging and therapy using radionuclides with emission energies below the Cerenkov threshold, thereby expanding the list of applicable radionuclides.

Considerations for Bioassay Monitoring of Mixtures of Radionuclides

DOE PAGES

Klumpp, John; Waters, Tom; Bertelli, Luiz

2017-10-01

Complying with regulations for bioassay monitoring of radionuclide intakes is significantly more complex for mixtures than it is for pure radionuclides. Different constituents will naturally have different dose coefficients, be detectable at significantly different levels, and may require very different amounts of effort to bioassay. The ability to use certain constituents as surrogates for others will depend on how well characterized the mixture is, as well as whether the employee is also working with other radionuclides. This is further compounded by the fact that the composition of a mixture (or even of a pure radionuclide) is likely to change overmore » time. Internal dosimetrists must decide how best to monitor employees who work with radionuclide mixtures. In particular, they must decide which constituents should be monitored routinely, which constituents only need to be monitored in the case of an intake, and how to estimate doses based on intakes of monitored and unmonitored constituents.« less

Depth distribution of radiocesium in Fukushima paddy fields and implications for ongoing decontamination works

NASA Astrophysics Data System (ADS)

Lepage, H.; Evrard, O.; Onda, Y.; Lefèvre, I.; Laceby, J. P.; Ayrault, S.

2014-09-01

Large quantities of radiocesium were deposited across a 3000 km2 area northwest of the Fukushima Dai-ichi nuclear power plant after the March 2011 accident. Although many studies have investigated the fate of radiocesium in soil in the months following the accident, the potential migration of this radioactive contaminant in rice paddy fields requires further examination after the typhoons that occurred in this region. Such investigations will help minimize potential human exposure in rice paddy fields or transfer of radioactive contaminants from soils to rice. Radionuclide activity concentrations and organic content were analysed in 10 soil cores sampled from paddy fields in November 2013, 20 km north of the Fukushima power plant. Our results demonstrate limited depth migration of radiocesium with the majority concentrated in the uppermost layers of soils (< 5 cm). More than 30 months after the accident, 81.5 to 99.7% of the total 137Cs inventories was still found within the < 5 cm of the soil surface, despite cumulative rainfall totalling 3300 mm. Furthermore, there were no significant correlations between radiocesium migration depth and total organic carbon content. We attributed the maximum depth penetration of 137Cs to maintenance (grass cutting - 97% of 137Cs in the upper 5 cm) and farming operations (tilling - 83% of 137Cs in the upper 5 cm). As this area is exposed to erosive events, ongoing decontamination works may increase soil erodibility. We therefore recommend the rapid removal of the uppermost - contaminated - layer of the soil after removing the vegetation to avoid erosion of contaminated material during the subsequent rainfall events. Remediation efforts should be concentrated on soils characterised by radiocesium activities > 10 000 Bq kg-1 to prevent the contamination of rice. Further analysis is required to clarify the redistribution of radiocesium eroded on river channels.

Vertical distribution of 137Cs in alluvial soils of the Lokna River floodplain (Tula oblast) long after the Chernobyl accident and its simulation

NASA Astrophysics Data System (ADS)

Mamikhin, S. V.; Golosov, V. N.; Paramonova, T. A.; Shamshurina, E. N.; Ivanov, M. M.

2016-12-01

Profiles of vertical 137Cs distribution in alluvial meadow soils on the low and medium levels of the Lokna River floodplain (central part of the Plavsk radioactive spot in Tula oblast) 28 years after the Chernobyl fallout have been studied. A significant increase in the 137Cs pool is revealed on the low floodplain areas compared to the soils of interfluves due to the accumulation of alluvium, which hampers the reduction of the total radionuclide pool in alluvial soils because of radioactive decay. The rate of alluvium accumulation in the soil on the medium floodplain level is lower by three times on average. An imitation prognostic model has been developed, which considers the flooding and climatic conditions in the region under study. Numerical experiments have quantitatively confirmed the deciding role of low-mobile forms in the migration of maximum 137Cs content along the soil profile in the absence of manifested erosion-accumulation processes.

Long Term Non-Invasive Imaging of Embryonic Stem Cells Using Reporter Genes

PubMed Central

Sun, Ning; Lee, Andrew; Wu, Joseph C.

2013-01-01

Development of non-invasive and accurate methods to track cell fate following delivery will greatly expedite transition of embryonic stem (ES) cell therapy to the clinic. Here we describe a protocol for the in vivo monitoring of stem cell survival, proliferation, and migration using reporter genes. We established stable ES cell lines constitutively expressing double fusion (DF; enhanced green fluorescent protein and firefly luciferase) or triple fusion (TF; monomeric red fluorescent protein, firefly luciferase, and herpes simplex virus thymidine kinase) reporter genes using lentiviral transduction. We used fluorescence activated cell sorting to purify these populations in vitro, bioluminescence imaging and positron emission tomography imaging to track them in vivo, and fluorescence immunostaining to confirm the results ex vivo. Unlike other methods of cell tracking such as iron particle and radionuclide labeling, reporter genes are inherited genetically and can be used to monitor cell proliferation and survival for the lifetime of transplanted cells and their progeny. PMID:19617890

Vadose Zone Transport Field Study: Status Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gee, Glendon W.; Ward, Anderson L.

2001-11-30

Studies were initiated at the Hanford Site to evaluate the process controlling the transport of fluids in the vadose zone and to develop a reliable database upon which vadose-zone transport models can be calibrated. These models are needed to evaluate contaminant migration through the vadose zone to underlying groundwaters at Hanford. A study site that had previously been extensively characterized using geophysical monitoring techniques was selected in the 200 E Area. Techniques used previously included neutron probe for water content, spectral gamma logging for radionuclide tracers, and gamma scattering for wet bulk density. Building on the characterization efforts of themore » past 20 years, the site was instrumented to facilitate the comparison of nine vadose-zone characterization methods: advanced tensiometers, neutron probe, electrical resistance tomography (ERT), high-resolution resistivity (HRR), electromagnetic induction imaging (EMI), cross-borehole radar (XBR), and cross-borehole seismic (XBS). Soil coring was used to obtain soil samples for analyzing ionic and isotopic tracers.« less

Discrete Fracture Network Modeling and Simulation of Subsurface Transport for the Topopah Springs and Lava Flow Aquifers at Pahute Mesa, FY 15 Progress Report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Makedonska, Nataliia; Kwicklis, Edward Michael; Birdsell, Kay Hanson

This progress report for fiscal year 2015 (FY15) describes the development of discrete fracture network (DFN) models for Pahute Mesa. DFN models will be used to upscale parameters for simulations of subsurface flow and transport in fractured media in Pahute Mesa. The research focuses on modeling of groundwater flow and contaminant transport using DFNs generated according to fracture characteristics observed in the Topopah Spring Aquifer (TSA) and the Lava Flow Aquifer (LFA). This work will improve the representation of radionuclide transport processes in large-scale, regulatory-focused models with a view to reduce pessimistic bounding approximations and provide more realistic contaminant boundarymore » calculations that can be used to describe the future extent of contaminated groundwater. Our goal is to refine a modeling approach that can translate parameters to larger-scale models that account for local-scale flow and transport processes, which tend to attenuate migration.« less

Development of performance assessment methodology for nuclear waste isolation in geologic media

NASA Astrophysics Data System (ADS)

Bonano, E. J.; Chu, M. S. Y.; Cranwell, R. M.; Davis, P. A.

The burial of nuclear wastes in deep geologic formations as a means for their disposal is an issue of significant technical and social impact. The analysis of the processes involved can be performed only with reliable mathematical models and computer codes as opposed to conducting experiments because the time scales associated are on the order of tens of thousands of years. These analyses are concerned primarily with the migration of radioactive contaminants from the repository to the environment accessible to humans. Modeling of this phenomenon depends on a large number of other phenomena taking place in the geologic porous and/or fractured medium. These are ground-water flow, physicochemical interactions of the contaminants with the rock, heat transfer, and mass transport. Once the radionuclides have reached the accessible environment, the pathways to humans and health effects are estimated. A performance assessment methodology for a potential high-level waste repository emplaced in a basalt formation has been developed for the U.S. Nuclear Regulatory Commission.

A refined characterization of the alluvial geology of yucca flat and its effect on bulk hydraulic conductivity

USGS Publications Warehouse

Phelps, G.A.; Halford, K.J.

2011-01-01

In Yucca Flat, on the Nevada National Security Site in southern Nevada, the migration of radionuclides from tests located in the alluvial deposits into the Paleozoic carbonate aquifer involves passage through a thick, heterogeneous section of late Tertiary and Quaternary alluvial sediments. An understanding of the lateral and vertical changes in the material properties of the alluvial sediments will aid in the further development of the hydrogeologic framework and the delineation of hydrostratigraphic units and hydraulic properties required for simulating groundwater flow in the Yucca Flat area. Previously published geologic models for the alluvial sediments within Yucca Flat are based on extensive examination and categorization of drill-hole data, combined with a simple, data-driven interpolation scheme. The U.S. Geological Survey, in collaboration with Stanford University, is researching improvements to the modeling of the alluvial section, incorporating prior knowledge of geologic structure into the interpolation method and estimating the uncertainty of the modeled hydrogeologic units.

Environmental aspects of the transuranics. A selected, annotated bibliography. Volume 9

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ensminger, J.T.; Fore, C.S.; Dailey, N.S.

This ninth published bibliography of 589 references is compiled from the Nevada Applied Ecology Information Center`s Data Base on the Environmental Aspects of the Transuranics. The data base was built to provide information support to the Nevada Applied Ecology Group (NAEG) of DOE`s Nevada Operations Office. The general scope covers environmental aspects of uranium and the transuranic elements, with emphasis on plutonium. This annotated bibliography highlights literature on plutonium 238 and 239 and americium 241 in the critical organs of man and animals. Studies on the migration of plutonium and the transplutonics through the environment are also emphasized. Supporting informationmore » on ecology of the Nevada Test Site and reviews and summarizing literature on other radionuclides have been included at the request of the NAEG. The references are arranged by subject category with leading authors appearing alphabetically within each category. Indexes are provided for author(s), geographic location, keywords, taxonomic name, title, and publication description.« less

Chemical tailoring of steam to remediate underground mixed waste contaminents

DOEpatents

Aines, Roger D.; Udell, Kent S.; Bruton, Carol J.; Carrigan, Charles R.

1999-01-01

A method to simultaneously remediate mixed-waste underground contamination, such as organic liquids, metals, and radionuclides involves chemical tailoring of steam for underground injection. Gases or chemicals are injected into a high pressure steam flow being injected via one or more injection wells to contaminated soil located beyond a depth where excavation is possible. The injection of the steam with gases or chemicals mobilizes contaminants, such as metals and organics, as the steam pushes the waste through the ground toward an extraction well having subatmospheric pressure (vacuum). The steam and mobilized contaminants are drawn in a substantially horizontal direction to the extraction well and withdrawn to a treatment point above ground. The heat and boiling action of the front of the steam flow enhance the mobilizing effects of the chemical or gas additives. The method may also be utilized for immobilization of metals by using an additive in the steam which causes precipitation of the metals into clusters large enough to limit their future migration, while removing any organic contaminants.

Optimizing Standard Sequential Extraction Protocol With Lake And Ocean Sediments

EPA Science Inventory

The environmental mobility/availability behavior of radionuclides in soils and sediments depends on their speciation. Experiments have been carried out to develop a simple but robust radionuclide sequential extraction method for identification of radionuclide partitioning in sed...

Methods of increasing the performance of radionuclide generators used in nuclear medicine: daughter nuclide build-up optimisation, elution-purification-concentration integration, and effective control of radionuclidic purity.

PubMed

Le, Van So; Do, Zoe Phuc-Hien; Le, Minh Khoi; Le, Vicki; Le, Natalie Nha-Truc

2014-06-10

Methods of increasing the performance of radionuclide generators used in nuclear medicine radiotherapy and SPECT/PET imaging were developed and detailed for 99Mo/99mTc and 68Ge/68Ga radionuclide generators as the cases. Optimisation methods of the daughter nuclide build-up versus stand-by time and/or specific activity using mean progress functions were developed for increasing the performance of radionuclide generators. As a result of this optimisation, the separation of the daughter nuclide from its parent one should be performed at a defined optimal time to avoid the deterioration in specific activity of the daughter nuclide and wasting stand-by time of the generator, while the daughter nuclide yield is maintained to a reasonably high extent. A new characteristic parameter of the formation-decay kinetics of parent/daughter nuclide system was found and effectively used in the practice of the generator production and utilisation. A method of "early elution schedule" was also developed for increasing the daughter nuclide production yield and specific radioactivity, thus saving the cost of the generator and improving the quality of the daughter radionuclide solution. These newly developed optimisation methods in combination with an integrated elution-purification-concentration system of radionuclide generators recently developed is the most suitable way to operate the generator effectively on the basis of economic use and improvement of purposely suitable quality and specific activity of the produced daughter radionuclides. All these features benefit the economic use of the generator, the improved quality of labelling/scan, and the lowered cost of nuclear medicine procedure. Besides, a new method of quality control protocol set-up for post-delivery test of radionuclidic purity has been developed based on the relationship between gamma ray spectrometric detection limit, required limit of impure radionuclide activity and its measurement certainty with respect to optimising decay/measurement time and product sample activity used for QC quality control. The optimisation ensures a certainty of measurement of the specific impure radionuclide and avoids wasting the useful amount of valuable purified/concentrated daughter nuclide product. This process is important for the spectrometric measurement of very low activity of impure radionuclide contamination in the radioisotope products of much higher activity used in medical imaging and targeted radiotherapy.

Past and present levels of some radionuclides in fish from Bikini and Enewetak Atolls.

PubMed

Noshkin, V E; Robison, W L; Wong, K M; Brunk, J L; Eagle, R J; Jones, H E

1997-07-01

Bikini and Enewetak were the sites in the Northern Marshall Islands that were used by the United States as testing grounds for nuclear devices between 1946 and 1958. The testing produced close-in fallout debris that was contaminated with different radionuclides and which entered the aquatic environment. The contaminated lagoon sediments became a reservoir and source term of manmade radionuclides for the resident marine organisms. This report contains a summary of all the available data on the concentrations of 137Cs, 60Co and 207Bi in flesh samples of reef and pelagic fish collected from Bikini and Enewetak Atolls between 1964 and 1995. The selection of these three radionuclides for discussion is based on the fact that these are the only radionuclides that have been routinely detected by gamma spectrometry in flesh samples from all fish for the last 20 y. Flesh from fish is an important source of food in the Marshallese diet. These radionuclides along with the transuranic radionuclides and 90Sr contribute most of the small radiological dose from ingesting marine foods. Some basic relationships among concentrations in different tissues and organs are discussed. The reef fish can be used as indicator species because their body burden is derived from feeding, over a lifetime, within a relatively small contaminated area of the lagoon. Therefore, the emphasis of this report is to use this extensive and unique concentration data base to describe the effective half lives and cycling for the radionuclides in the marine environments during the 31-y period between 1964 and 1995. The results from an analysis of the radionuclide concentrations in the flesh samples indicate the removal rates for the 3 radionuclides are significantly different. 137Cs is removed from the lagoons with an effective half life of 9-12 y. Little 60Co is mobilized to the water column so that it is depleted in both environments, primarily through radioactive decay. The properties of 207Bi are different at Enewetak and Bikini. At Enewetak the radionuclide is lost from the environment with an effective half live of 5.1 y. At Bikini only radioactive decay can account for the rate at which the radionuclide is lost from the lagoon. The difference in the binding properties of the sedimentary materials for 207Bi among the two Atolls is not understood.

Groundwater Flow Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada, Revision 0

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greg Ruskauff

2006-06-01

The Pahute Mesa groundwater flow model supports the FFACO UGTA corrective action strategy objective of providing an estimate of the vertical and horizontal extent of contaminant migration for each CAU in order to predict contaminant boundaries. A contaminant boundary is the model-predicted perimeter that defines the extent of radionuclide-contaminated groundwater from underground nuclear testing above background conditions exceeding Safe Drinking Water Act (SDWA) standards. The contaminant boundary will be composed of both a perimeter boundary and a lower hydrostratigraphic unit (HSU) boundary. Additional results showing contaminant concentrations and the location of the contaminant boundary at selected times will also bemore » presented. These times may include the verification period, the end of the five-year proof-of-concept period, as well as other times that are of specific interest. The FFACO (1996) requires that the contaminant transport model predict the contaminant boundary at 1,000 years and “at a 95% level of confidence.” The Pahute Mesa Phase I flow model described in this report provides, through the flow fields derived from alternative hydrostratigraphic framework models (HFMs) and recharge models, one part of the data required to compute the contaminant boundary. Other components include the simplified source term model, which incorporates uncertainty and variability in the factors that control radionuclide release from an underground nuclear test (SNJV, 2004a), and the transport model with the concomitant parameter uncertainty as described in Shaw (2003). The uncertainty in all the above model components will be evaluated to produce the final contaminant boundary. This report documents the development of the groundwater flow model for the Central and Western Pahute Mesa CAUs.« less

Evaluation of liners for a uranium-mill tailings disposal site: a status report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Buelt, J.L.; Hale, V.Q.; Barnes, S.M.

1981-05-01

The United States Department of Energy is conducting a program designed to reclaim or stabilize inactive uranium-mill tailings sites. This report presents the status of the Liner Evaluation Program. The purpose of the study was to identify eight prospective lining materials or composites for laboratory testing. The evaluation was performed by 1) reviewing proposed regulatory requirements to define the material performance criteria; 2) reviewing published literature and communicating with industrial and government experts experienced with lining materials and techniques; and 3) characterizing the tailings at three of the sites for calcium concentration, a selection of anions, radionuclides, organic solvents, andmore » acidity levels. The eight materials selected for laboratory testing are: natural soil amended with sodium-saturated montmorillonite (Volclay); locally available clay in conjunction with an asphalt emulsion radon suppression cover; locally available clay in conjunction with a multibarrier radon suppression cover; rubberized asphalt membrane; hydraulic asphalt concrete; chlorosulfonated polyethylene (hypalon) or high-density polyethylene; bentonite, sand and gravel mixture; and catalytic airblown asphalt membrane. The materials will be exposed in test units now being constructed to conditions such as wet/dry cycles, temperature cycles, oxidative environments, ion-exchange elements, etc. The results of the tests will identify the best material for field study. The status report also presents the information gathered during the field studies at Grand Junction, Colorado. Two liners, a bentonite, sand and gravel mixture, and a catalytic airblown asphalt membrane, were installed in a prepared trench and covered with tailings. The liners were instrumented and are being monitored for migration of moisture, radionuclides, and hazardous chemicals. The two liner materials will also be subjected to accelerated laboratory tests for a comparative assessment.« less

Nevada Test Site annual site environmental report for calendar year 1996

DOE Office of Scientific and Technical Information (OSTI.GOV)

Black, S.C.; Townsend, Y.E.

1997-10-01

Monitoring and surveillance on and around the Nevada Test Site (NTS) by US Department of Energy (DOE) contractors and NTS user organizations during 1996 indicated that operations on the NTS were conducted in compliance with applicable DOE, state, and federal regulations and guidelines. All discharges of radioactive liquids remained onsite in containment ponds, and there was no indication of potential migration of radioactivity to the offsite area through groundwater. Surveillance around the NTS indicated that airborne radioactivity from diffusion, evaporation of liquid effluents, or resuspension of soil was not detectable offsite, and exposure above background to members of the offsitemore » population was not measured by the offsite monitoring program. Using the US Environmental Protection Agency`s (EPA) Clean Air Package 1988 (CAP88)PC model and NTS radionuclide emissions and environmental monitoring data, the calculated effective dose equivalent (EDE) to the maximally exposed individual offsite would have been 0.11 mrem. This value is less than 2 percent of the federal dose limit prescribed for radionuclide air emissions. Any person receiving this dose would also have received 144 mrem from natural background radiation. There were no nonradiological releases to the offsite area. Hazardous wastes were shipped offsite to approved disposal facilities. Compliance with the various regulations stemming from the National Environmental Policy Act (NEPA) is being achieved and, where mandated, permits for air and water effluents and waste management have been obtained from the appropriate agencies. Cooperation with other agencies has resulted in seven different consent orders and agreements. Support facilities at off-NTS locations have complied with the requirements of air quality permits and state or local wastewater discharge and hazardous waste permits as mandated for each location.« less

GROUNDWATER REMEDIATION SOLUTIONS AT HANFORD

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gilmore, Tyler J.; Truex, Michael J.; Williams, Mark D.

2007-02-26

In 2006, Congress provided funding to the U. S. Department of Energy (DOE) to study new technologies that could be used to treat contamination from the Hanford Site that might impact the Columbia River. The contaminants of concern are primarily metals and radionuclides, which are byproducts of Hanford’s cold war mission to produce plutonium for atomic weapons. The DOE asked Pacific Northwest National Laboratory (PNNL) to consider this problem and develop approaches to address the contamination that threatens the river. DOE identified three high priority sites that had groundwater contamination migrating towards the Columbia river for remediation. The contaminants includedmore » strontium-90, uranium and chromium. Remediation techniques for metals and radionuclides focus primarily on altering the oxidation state of the contaminant chemically or biologically, isolating the contaminants from the environment through adsorption or encapsulation or concentrating the contaminants for removal. A natural systems approach was taken that uses a mass balance concept to frame the problem and determine the most appropriate remedial approach. This approach provides for a scientifically based remedial decision. The technologies selected to address these contaminants included an apatite adsorption barrier coupled with a phytoremediation to address the strontium-90 contamination, injection of polyphosphate into the subsurface to sequester uranium, and a bioremediation approach to reduce chromium contamination in the groundwater. The ability to provide scientifically based approaches is in large part due to work developed under previous DOE Office of Science and Office of Environmental Management projects. For example, the polyphosphate and the bioremediation techniques, were developed by PNNL under the EMSP and NABIR programs. Contaminated groundwater under the Hanford Site poses a potential risk to humans and the Columbia River. These new technologies holds great promise for effectively remediating the residual waste that threatens the environment.« less

Colloid labelled with radionuclide and method

DOEpatents

Atcher, R.W.; Hines, J.J.

1990-11-13

A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints. No Drawings

Method of making colloid labeled with radionuclide

DOEpatents

Atcher, Robert W.; Hines, John J.

1991-01-01

A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints.

Colloid labelled with radionuclide and method

DOEpatents

Atcher, Robert W.; Hines, John J.

1990-01-01

A ferric hydroxide colloid having an alpha-emitting radionuclide essentially on the outer surfaces and a method of forming same. The method includes oxidizing a ferrous hydroxide to ferric hydroxide in the presence of a preselected radionuclide to form a colloid having the radionuclide on the outer surface thereof, and thereafter washing the colloid, and suspending the washed colloid in a suitable solution. The labelled colloid is useful in cancer therapy and for the treatment of inflamed joints.

[Qualitative composition of dominating forms of microorganisms isolated from radionuclide contaminated soil and their ability to accumulate 137Cs].

PubMed

Pareniuk, O Iu; Moshynets', O V; Tytova, L V; Levchuk, S Ie

2013-01-01

Qualitative composition of the dominating forms of microorganisms isolated from radionuclide contaminated soils has been studied. The ability to accumulate 137Cs by freshly isolated species and collection cultures that were not adapted to the presence of the radionuclide has been analyzed. It is shown that among the analyzed microorganisms the greatest ability to accumulate the radionuclide is inherent in the collection culture Bacillus megaterium UKMV-5724.

10 CFR 960.4-2-2 - Geochemistry.

Code of Federal Regulations, 2013 CFR

2013-01-01

.... Considering the likely chemical interactions among radionuclides, the host rock, and the ground water, the... the rock matrix, or sorption of radionuclides; inhibit the formation of particulates, colloids... transport of radionuclides by particulates, colloids, or complexes. (3) Mineral assemblages that, when...

10 CFR 960.4-2-2 - Geochemistry.

Code of Federal Regulations, 2014 CFR

2014-01-01

.... Considering the likely chemical interactions among radionuclides, the host rock, and the ground water, the... the rock matrix, or sorption of radionuclides; inhibit the formation of particulates, colloids... transport of radionuclides by particulates, colloids, or complexes. (3) Mineral assemblages that, when...

Long-term modelling of fly ash and radionuclide emissions as well as deposition fluxes due to the operation of large oil shale-fired power plants.

PubMed

Vaasma, Taavi; Kaasik, Marko; Loosaar, Jüri; Kiisk, Madis; Tkaczyk, Alan H

2017-11-01

Two of the world's largest oil shale-fired power plants (PPs) in Estonia have been operational over 40 years, emitting various pollutants, such as fly ash, SO x , NO x , heavy metals, volatile organic compounds as well as radionuclides to the environment. The emissions from these PPs have varied significantly during this period, with the maximum during the 1970s and 1980s. The oil shale burned in the PPs contains naturally occurring radionuclides from the 238 U and 232 Th decay series as well as 40 K. These radionuclides become enriched in fly ash fractions (up to 10 times), especially in the fine fly ash escaping the purification system. Using a validated Gaussian-plume model, atmospheric dispersion modelling was carried out to determine the quantity and a real magnitude of fly ash and radionuclide deposition fluxes during different decades. The maximum deposition fluxes of volatile radionuclides ( 210 Pb and 210 Po) were around 70 mBq m -2 d -1 nearby the PPs during 1970s and 1980s. Due to the reduction of burned oil shale and significant renovations done on the PPs, the deposition fluxes were reduced to 10 mBq m -2 d -1 in the 2000s and down to 1.5 mBq m -2 d -1 in 2015. The maximum deposition occurs within couple of kilometers of the PPs, but the impacted area extends to over 50 km from the sources. For many radionuclides, including 210 Po, the PPs have been larger contributors of radionuclides to the environment via atmospheric pathway than natural sources. This is the first time that the emissions and deposition fluxes of radionuclides from the PPs have been quantified, providing the information about their radionuclide deposition load on the surrounding environment during various time periods. Copyright © 2017 Elsevier Ltd. All rights reserved.

Developing of Watershed Radionuclide Transport Model DHSVM-R as Modification and Extension of Distributed Hydrological and Sediment Dynamics Model DHSVM

NASA Astrophysics Data System (ADS)

Zheleznyak, M.; Kivva, S.; Onda, Y.; Nanba, K.; Wakiyama, Y.; Konoplev, A.

2015-12-01

The reliable modeling tools for prediction wash - off radionuclides from watersheds are needed as for assessment the consequences of accidental and industrial releases of radionuclides, as for soil erosion studies using the radioactive tracers. The distributed model of radionuclide transport through watershed in exchangeable and nonexchangeable forms in solute and with sediments was developed and validated for small Chernobyl watersheds in 90th within EU SPARTACUS project (van der Perk et al., 1996). New tendency is coupling of radionuclide transport models and the widely validated hydrological distributed models. To develop radionuclide transport model DHSVM-R the open source Distributed Hydrology Soil Vegetation Model -DHSVM http://www.hydro.washington.edu/Lettenmaier/Models/DHSVM was modified and extended. The main changes provided in the hydrological and sediment transport modules of DHSVM are as follows: Morel-Seytoux infiltration model is added; four-directions schematization for the model's cells flows (D4) is replaced by D8 approach; the finite-difference schemes for solution of kinematic wave equations for overland water flow, stream net flow, and sediment transport are replaced by new computationally efficient scheme. New radionuclide transport module, coupled with hydrological and sediment transport modules, continues SPARTACUS's approach, - it describes radionuclide wash-off from watershed and transport via stream network in soluble phase and on suspended sediments. The hydrological module of DHSVM-R was calibrated and validated for the watersheds of Ukrainian Carpathian mountains and for the subwatersheds of Niida river flowing 137Cs in solute and with suspended sediments to Pacific Ocean at 30 km north of the Fukushima Daiichi NPP. The modules of radionuclide and sediment transport were calibrated and validated versus experimental data for USLE experimental plots in Fukushima Prefecture and versus monitoring data collected in Niida watershed. The role of sediment transport in radionuclide wash-off from mountain and lowland watersheds is analyzed in comparison of modeling results for Chernobyl and Fukushima watersheds.

Study on vertical distribution of radionuclides ({sup 40}K, Th and U) in soil collected from Manjung district

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zainal, Fetri; Hamzah, Zaini; Wood, Khalik

2016-01-22

The accumulation of radionuclides in soil is a greatest concerns due to their toxicity. This study investigated the vertical distribution of radionuclides and radiological assessment in a soil profile were collected in three different directions [North (N), North-East (NE) and South-East (SE)] within 40 km from Manjung district. All profile samples were collected down to 45cm at 7.5cm interval using hand auger. Soil density and radionuclides ({sup 40}K, Th and U) concentrations were determined by gravimetric method and Energy Dispersive X-Ray Fluorescence (EDXRF) technique, respectively. The radionuclides concentrations was in decreasing order of {sup 40}K > Th > U. Soil qualitymore » assessment was carried out using Enrichment Factor (EF), Pollution Index (PI) and Geoaccumulation Index (I {sub geo}) where all radionuclides show significant enrichment (5 < EF < 20), PI classified as middle pollution classes and 0 < Igeo < 1, indicating moderately polluted, respectively. From the concentration of radionuclides, the radiological risk was calculated and the present result show external hazard index (H{sub ex}) is below than unity indicate low radiological risk.« less

The interference of medical radionuclides with occupational in vivo gamma spectrometry.

PubMed

Kol, R; Pelled, O; Canfi, A; Gilad, Y; German, U; Laichter, Y; Lantsberg, S; Fuksbrauner, R; Gold, B

2003-06-01

Radiation workers undergo routine monitoring for the evaluation of external and internal radiation exposures. The monitoring of internal exposures involves gamma spectrometry of the whole body (whole body counting) and measurements of excreta samples. Medical procedures involving internal administration of radioactive radionuclides are widely and commonly used. Medical radionuclides are typically short-lived, but high activities are generally administered, whereas occupational radionuclides are mostly long-lived and, if present, are found generally in relatively smaller quantities. The aim of the present work was to study the interference of some common medical radionuclides (201Tl, 9mTc, 57Co, and 131I) with the detection of internal occupational exposures to natural uranium and to 137Cs. Workers having undergone a medical procedure with one of the radionuclides mentioned above were asked to give frequent urine samples and to undergo whole body and thyroid counting with phoswich detectors operated at the Nuclear Research Center Negev. Urine and whole body counting monitoring were continued as long as radioactivity was detectable by gamma spectrometry. The results indicate that the activity of medical radionuclides may interfere with interpretation of occupational intakes for months after administration.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, J.; Glucksberg, N.; Fogg, A.

During the site closure of nuclear facilities where both radionuclides and chemicals are present in environmental media, state and federal regulatory agencies other than the Nuclear Regulatory Commission often have a stake in the regulation of the site closure process. At the Connecticut Yankee Atomic Power Company (CYAPCO) Haddam Neck Plant in Haddam, Connecticut, the site closure process includes both radiological and chemical cleanup which is regulated by two separate divisions within the state and two federal agencies. Each of the regulatory agencies has unique closure criteria which pertain to radionuclides and, consequently, there is overlapping and in some casesmore » disparate regulation of radionuclides. Considerable effort has been expended by CYAPCO to find common ground in meeting the site closure requirements for radionuclides required by each of the agencies. This paper discusses the approaches that have been used by CYAPCO to address radionuclide site closure requirements. Significant lessons learned from these approaches include the demonstration that public health cleanup criteria for most radionuclides of concern at nuclear power generation facilities are protective for chemical toxicity concerns and are protective for ecological receptors and, consequently, performing a baseline ecological risk assessment for radionuclides at power generation facilities is not generally necessary. (authors)« less

ITE CHARACTERIZATION TO SUPPORT CONCEPTUAL MODEL DEVELOPMENT FOR SUBSURFACE RADIONUCLIDE TRANSPORT

EPA Science Inventory

Remediation of radionuclide contaminants in ground water often begins with the development of conceptual and analytical models that guide our understanding of the processes controlling radionuclide transport. The reliability of these models is often predicated on the collection o...

Method for immobilizing mixed waste chloride salts containing radionuclides and other hazardous wastes

DOEpatents

Lewis, Michele A.; Johnson, Terry R.

1993-01-01

The invention is a method for the encapsulation of soluble radioactive waste chloride salts containing radionuclides such as strontium, cesium and hazardous wastes such as barium so that they may be permanently stored without future threat to the environment. The process consists of contacting the salts containing the radionuclides and hazardous wastes with certain zeolites which have been found to ion exchange with the radionuclides and to occlude the chloride salts so that the resulting product is leach resistant.

Method for immobilizing mixed waste chloride salts containing radionuclides and other hazardous wastes

DOEpatents

Lewis, Michele A.; Johnson, Terry R.

1993-09-07

The invention is a method for the encapsulation of soluble radioactive waste chloride salts containing radionuclides such as strontium, cesium and hazardous wastes such as barium so that they may be permanently stored without future threat to the environment. The process consists of contacting the salts containing the radionuclides and hazardous wastes with certain zeolites which have been found to ion exchange with the radionuclides and to occlude the chloride salts so that the resulting product is leach resistant.

A new approach to nuclear fuel safeguard enhancement through radionuclide profiling

NASA Astrophysics Data System (ADS)

Peterson, Aaron Dawon

The United States has led the effort to promote peaceful use of nuclear power amongst states actively utilizing it as well as those looking to deploy the technology in the near future. With the attraction being demonstrated by various countries towards nuclear power comes the concern that a nation may have military aspirations for the use of nuclear energy. The International Atomic Energy Agency (IAEA) has established nuclear safeguard protocols and procedures to mitigate nuclear proliferation. The work herein proposed a strategy to further enhance existing safeguard protocols by considering safeguard in nuclear fuel design. The strategy involved the use of radionuclides to profile nuclear fuels. Six radionuclides were selected as identifier materials. The decay and transmutation of these radionuclides were analyzed in reactor operation environment. MCNPX was used to simulate a reactor core. The perturbation in reactivity of the core due to the loading of the radionuclides was insignificant. The maximum positive and negative reactivity change induced was at day 1900 with a value of 0.00185 +/- 0.00256 and at day 2000 with -0.00441 +/- 0.00249, respectively. The mass of the radionuclides were practically unaffected by transmutation in the core; the change in radionuclide inventory was dominated by natural decay. The maximum material lost due to transmutation was 1.17% in Eu154. Extraneous signals from fission products identical to the radionuclide compromised the identifier signals. Eu154 saw a maximum intensity change at EOC and 30 days post-irradiation of 1260% and 4545%, respectively. Cs137 saw a minimum change of 12% and 89%, respectively. Mitigation of the extraneous signals is cardinal to the success of the proposed strategy. The predictability of natural decay provides a basis for the characterization of the signals from the radionuclide.

EANM guidelines for radionuclide therapy of bone metastases with beta-emitting radionuclides.

PubMed

Handkiewicz-Junak, Daria; Poeppel, Thorsten D; Bodei, Lisa; Aktolun, Cumali; Ezziddin, Samer; Giammarile, Francesco; Delgado-Bolton, Roberto C; Gabriel, Michael

2018-05-01

The skeleton is the most common metastatic site in patients with advanced cancer. Pain is a major healthcare problem in patients with bone metastases. Bone-seeking radionuclides that selectively accumulate in the bone are used to treat cancer-induced bone pain and to prolong survival in selected groups of cancer patients. The goals of these guidelines are to assist nuclear medicine practitioners in: (a) evaluating patients who might be candidates for radionuclide treatment of bone metastases using beta-emitting radionuclides such as strontium-89 ( 89 Sr), samarium-153 ( 153 Sm) lexidronam ( 153 Sm-EDTMP), and phosphorus-32 ( 32 P) sodium phosphate; (b) performing the treatments; and ©) understanding and evaluating the treatment outcome and side effects.

Monitoring release of disposable radionuclides in the Kara sea: Bioaccumulation of long-lived radionuclides in echinoderms and molluscs

DOE Office of Scientific and Technical Information (OSTI.GOV)

Fisher, N.S.

1994-01-01

The objective of the present proposal is to continue and extend our research on the trophic transfer of important radionuclides in benthic fauna of the Kara Sea. This project is assessing the extent to which select species of seastars, brittle stars, and clams typical of the Kara Sea concentrate and retain a variety of long-lived radionuclides known to be (or suspected to be) present in the disposed wastes in the Russian Arctic. The rates and routes of uptake and depuration of isotopes in the same or in closely related species are being quantified so that endemic benthic organisms can bemore » assessed as potential bioindicators of released radionuclides in Arctic waters.« less

Developments in Bioremediation of Soils and Sediments Pollutedwith Metals and Radionuclides: 2. Field Research on Bioremediation of Metals and Radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hazen, Terry C.; Tabak, Henry H.

2007-03-15

Bioremediation of metals and radionuclides has had manyfield tests, demonstrations, and full-scale implementations in recentyears. Field research in this area has occurred for many different metalsand radionuclides using a wide array of strategies. These strategies canbe generally characterized in six major categories: biotransformation,bioaccumulation/bisorption, biodegradation of chelators, volatilization,treatment trains, and natural attenuation. For all field applicationsthere are a number of critical biogeochemical issues that most beaddressed for the successful field application. Monitoring andcharacterization parameters that are enabling to bioremediation of metalsand radionuclides are presented here. For each of the strategies a casestudy is presented to demonstrate a field application that usesmore » thisstrategy.« less

Radionuclides in haematology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Lewis, S.M.; Bayly, R.J.

1986-01-01

This book contains the following chapters: Some prerequisites to the use of radionuclides in haematology; Instrumentation and counting techniques; In vitro techniques; Cell labelling; Protein labelling; Autoradiography; Imaging and quantitative scanning; Whole body counting; Absorption and excretion studies; Blood volume studies; Plasma clearance studies; and Radionuclide blood cell survival studies.

21 CFR 892.5650 - Manual radionuclide applicator system.

Code of Federal Regulations, 2013 CFR

2013-04-01

... system. (a) Identification. A manual radionuclide applicator system is a manually operated device... 21 Food and Drugs 8 2013-04-01 2013-04-01 false Manual radionuclide applicator system. 892.5650... planning computer programs, and accessories. (b) Classification. Class I (general controls). The device is...

21 CFR 892.5650 - Manual radionuclide applicator system.

Code of Federal Regulations, 2011 CFR

2011-04-01

... system. (a) Identification. A manual radionuclide applicator system is a manually operated device... 21 Food and Drugs 8 2011-04-01 2011-04-01 false Manual radionuclide applicator system. 892.5650... planning computer programs, and accessories. (b) Classification. Class I (general controls). The device is...

21 CFR 892.5650 - Manual radionuclide applicator system.

Code of Federal Regulations, 2010 CFR

2010-04-01

... system. (a) Identification. A manual radionuclide applicator system is a manually operated device... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Manual radionuclide applicator system. 892.5650... planning computer programs, and accessories. (b) Classification. Class I (general controls). The device is...

21 CFR 892.5650 - Manual radionuclide applicator system.

Code of Federal Regulations, 2014 CFR

2014-04-01

... system. (a) Identification. A manual radionuclide applicator system is a manually operated device... 21 Food and Drugs 8 2014-04-01 2014-04-01 false Manual radionuclide applicator system. 892.5650... planning computer programs, and accessories. (b) Classification. Class I (general controls). The device is...

21 CFR 892.5650 - Manual radionuclide applicator system.

Code of Federal Regulations, 2012 CFR

2012-04-01

... system. (a) Identification. A manual radionuclide applicator system is a manually operated device... 21 Food and Drugs 8 2012-04-01 2012-04-01 false Manual radionuclide applicator system. 892.5650... planning computer programs, and accessories. (b) Classification. Class I (general controls). The device is...

21 CFR 892.5740 - Radionuclide teletherapy source.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide teletherapy source. 892.5740 Section 892.5740 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5740 Radionuclide teletherapy source...

21 CFR 892.5730 - Radionuclide brachytherapy source.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide brachytherapy source. 892.5730 Section 892.5730 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Therapeutic Devices § 892.5730 Radionuclide brachytherapy...

Quantitative Modeling of Cerenkov Light Production Efficiency from Medical Radionuclides

PubMed Central

Beattie, Bradley J.; Thorek, Daniel L. J.; Schmidtlein, Charles R.; Pentlow, Keith S.; Humm, John L.; Hielscher, Andreas H.

2012-01-01

There has been recent and growing interest in applying Cerenkov radiation (CR) for biological applications. Knowledge of the production efficiency and other characteristics of the CR produced by various radionuclides would help in accessing the feasibility of proposed applications and guide the choice of radionuclides. To generate this information we developed models of CR production efficiency based on the Frank-Tamm equation and models of CR distribution based on Monte-Carlo simulations of photon and β particle transport. All models were validated against direct measurements using multiple radionuclides and then applied to a number of radionuclides commonly used in biomedical applications. We show that two radionuclides, Ac-225 and In-111, which have been reported to produce CR in water, do not in fact produce CR directly. We also propose a simple means of using this information to calibrate high sensitivity luminescence imaging systems and show evidence suggesting that this calibration may be more accurate than methods in routine current use. PMID:22363636

Iodine Pathways and Off-Gas Stream Characteristics for Aqueous Reprocessing Plants – A Literature Survey and Assessment

DOE Office of Scientific and Technical Information (OSTI.GOV)

R. T. Jubin; D. M. Strachan; N. R. Soelberg

2013-09-01

Used nuclear fuel is currently being reprocessed in only a few countries, notably France, England, Japan, and Russia. The need to control emissions of the gaseous radionuclides to the air during nuclear fuel reprocessing has already been reported for the entire plant. But since the gaseous radionuclides can partition to various different reprocessing off-gas streams, for example, from the head end, dissolver, vessel, cell, and melter, an understanding of each of these streams is critical. These off-gas streams have different flow rates and compositions and could have different gaseous radionuclide control requirements, depending on how the gaseous radionuclides partition. Thismore » report reviews the available literature to summarize specific engineering data on the flow rates, forms of the volatile radionuclides in off-gas streams, distributions of these radionuclides in these streams, and temperatures of these streams. This document contains an extensive bibliography of the information contained in the open literature.« less

Separation of nuclear isomers for cancer therapeutic radionuclides based on nuclear decay after-effects.

PubMed

Bhardwaj, R; van der Meer, A; Das, S K; de Bruin, M; Gascon, J; Wolterbeek, H T; Denkova, A G; Serra-Crespo, P

2017-03-13

177 Lu has sprung as a promising radionuclide for targeted therapy. The low soft tissue penetration of its β - emission results in very efficient energy deposition in small-size tumours. Because of this, 177 Lu is used in the treatment of neuroendocrine tumours and is also clinically approved for prostate cancer therapy. In this work, we report a separation method that achieves the challenging separation of the physically and chemically identical nuclear isomers, 177m Lu and 177 Lu. The separation method combines the nuclear after-effects of the nuclear decay, the use of a very stable chemical complex and a chromatographic separation. Based on this separation concept, a new type of radionuclide generator has been devised, in which the parent and the daughter radionuclides are the same elements. The 177m Lu/ 177 Lu radionuclide generator provides a new production route for the therapeutic radionuclide 177 Lu and can bring significant growth in the research and development of 177 Lu based pharmaceuticals.

Method of separating short half-life radionuclides from a mixture of radionuclides

DOEpatents

Bray, Lane A.; Ryan, Jack L.

1999-01-01

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the 22.sup.9 Th or 2.sup.27 Ac "cow" radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium; lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture; are removed from the mixture on the chloride form anion exchange column.

Method of separating short half-life radionuclides from a mixture of radionuclides

DOEpatents

Bray, L.A.; Ryan, J.L.

1999-03-23

The present invention is a method of removing an impurity of plutonium, lead or a combination thereof from a mixture of radionuclides that contains the impurity and at least one parent radionuclide. The method has the steps of (a) insuring that the mixture is a hydrochloric acid mixture; (b) oxidizing the acidic mixture and specifically oxidizing the impurity to its highest oxidation state; and (c) passing the oxidized mixture through a chloride form anion exchange column whereupon the oxidized impurity absorbs to the chloride form anion exchange column and the {sup 229}Th or {sup 227}Ac ``cow`` radionuclide passes through the chloride form anion exchange column. The plutonium is removed for the purpose of obtaining other alpha emitting radionuclides in a highly purified form suitable for medical therapy. In addition to plutonium, lead, iron, cobalt, copper, uranium, and other metallic cations that form chloride anionic complexes that may be present in the mixture are removed from the mixture on the chloride form anion exchange column. 8 figs.

Specificity of Cs-137 redistribution in toposequence of arable soils cultivated after the Chernobyl accident

NASA Astrophysics Data System (ADS)

Korobova, Elena; Romanov, Sergey; Baranchukov, Vladimir; Berezkin, Victor; Moiseenko, Fedor; Kirov, Sergey

2017-04-01

Investigations performed after the Chernobyl accident showed high spatial variation of radionuclide contamination of the soil cover in elementary landscape geochemical systems (ELGS) that characterize catena's structure. Our studies of Cs-137 distribution along and cross the slopes of local ridges in natural forested key site revealed a cyclic character of variation of the radionuclide surface activity along the studied transections (Korobova et al, 2008; Korobova, Romanov, 2009; 2011). We hypothesized that the observed pattern reflects a specific secondary migration of Cs-137 with water, and that this process could have taken place in any ELGS. To test this hypothesis a detailed field measurement of Cs-137 surface activity was performed in ELGS in agricultural area cultivated after the Chernobyl accident but later withdrawn from land-use. In situ measurements carried out by field gamma-spectrometry were accompanied by soil core sampling at the selected points. Soil samples were taken in increments of 2 cm down to 20 cm and of 5 cm down to 40 cm. The samples were analyzed for Cs-137 in laboratory using Canberra gamma-spectrometer with HP-Ge detector. Obtained results confirmed the fact of area cultivation down to 20 cm that was clearly traced by Cs-137 profile in soil columns. At the same time, the measurements also showed a cyclic character of Cs-137 variation in a sequence of ELGS from watershed to the local depression similar to that found in woodland key site. This proved that the observed pattern is a natural process typical for matter migration in ELGS independently of the vegetation type and ploughing. Therefore, spatial aspect is believed to be an important issue for development of adequate technique for a forecast of contamination of agricultural production and remediation of the soil cover on the local scale within the contaminated areas. References Korobova, E.M., Romanov, S.L., 2009. A Chernobyl 137Cs contamination study as an example for the spatial structure of geochemical fields and modeling of the geochemical field //Chemometrics and Intelligent Laboratory Systems, 99, 1-8. Korobova, E., Romanov S., 2011. Experience of mapping spatial structure of Cs-137 in natural landscape and patterns of its distribution in soil toposequence // Journal of Geochemical Exploration, 109, 1-3, 139-145. Korobova Elena, Sergey Romanov, Vladimir Samsonov, Fedor Moiseenko, 2008. Peculiarities of spatial structure of 137Cs contamination field in landscape toposequence: regularities in geo-field structure. Proceedings of the International Conference on Radioecology and Environmental Radioactivity, 15-20 June 2008, Bergen, Norway, Part 2, 182-186.

Behavior of 131I and 137Cs in environments released from the Fukushima nuclear disaster

NASA Astrophysics Data System (ADS)

Ohta, T.; Mahara, Y.; Kubota, T.; Igarashi, T.

2011-12-01

The devastating tsunami that caused by the great earthquake (M = 9.0) off the coast of northeastern Honshu on 11 March 2011 destroyed large coastal areas of Tohoku and north Kanto, Japan. Radionuclides, including 131I, 134Cs, and 137Cs, were released into the atmosphere from the Fukushima Daiichi plants. Concentration of levels of 131I, 134Cs, and 137Cs in Ibaraki Prefecture, Japan, released from the Fukushima Daiichi plant were investigated in the soil and precipitation. The concentrations of 131I and 137Cs in the soil from the surface to 1 cm depth in Ibaraki Prefecture were 9360-13,400 Bq/kg and 720-3250 Bq/kg, respectively. The concentration of 137Cs at this soil observation site originating from the Fukushima plant was 8.4 to 21 times that found locally after the Nagasaki atomic bomb explosion. Most of the 134Cs and 137Cs from rainwater were trapped by the surface soil and sand to a depth of 1 cm, whereas only about 30% of the 131I was collected by the surface soil, suggesting that 131I would move deeper than 137Cs and 134Cs. The 131I in the rainwater was in the anion exchangeable form, and all of it could be collected by anion exchangeable mechanisms, whereas 30% of the 131I that had passed through the soil could not be trapped by the anion exchange resin, suggesting that the chemical form of this 30% was in a changeable, organic-bound form. The 131I, 134Cs, and 137Cs that were absorbed on soil were difficult to be dissolved into water. As the half-life of 131I is short and 137Cs is strongly adsorbed on the surface soil and sand, these radionuclides would be unlikely to reach the groundwater before completely decaying; contamination of groundwater with 131I and 137Cs supplied from rainwater to the surface soil is therefore exceedingly unlikely. As the 137Cs is likely to migrate only 0.6 cm in 10 years, people living in the Fukushima and Kanto areas will be exposed to radiation from 137Cs in the surface soil and sand. For protection, surface soils and sands with high levels of radiation need to be replaced with uncontaminated soils below a depth of about 30 cm. If this exchange operation will be done, even though the 137Cs will be placed deeper, its slow migration rate will ensure that it never reaches the groundwater.

Transport and fate of radionuclides in aquatic environments--the use of ecosystem modelling for exposure assessments of nuclear facilities.

PubMed

Kumblad, L; Kautsky, U; Naeslund, B

2006-01-01

In safety assessments of nuclear facilities, a wide range of radioactive isotopes and their potential hazard to a large assortment of organisms and ecosystem types over long time scales need to be considered. Models used for these purposes have typically employed approaches based on generic reference organisms, stylised environments and transfer functions for biological uptake exclusively based on bioconcentration factors (BCFs). These models are of non-mechanistic nature and involve no understanding of uptake and transport processes in the environment, which is a severe limitation when assessing real ecosystems. In this paper, ecosystem models are suggested as a method to include site-specific data and to facilitate the modelling of dynamic systems. An aquatic ecosystem model for the environmental transport of radionuclides is presented and discussed. With this model, driven and constrained by site-specific carbon dynamics and three radionuclide specific mechanisms: (i) radionuclide uptake by plants, (ii) excretion by animals, and (iii) adsorption to organic surfaces, it was possible to estimate the radionuclide concentrations in all components of the modelled ecosystem with only two radionuclide specific input parameters (BCF for plants and Kd). The importance of radionuclide specific mechanisms for the exposure to organisms was examined, and probabilistic and sensitivity analyses to assess the uncertainties related to ecosystem input parameters were performed. Verification of the model suggests that this model produces analogous results to empirically derived data for more than 20 different radionuclides.

21 CFR 892.1360 - Radionuclide dose calibrator.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide dose calibrator. 892.1360 Section 892.1360 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1360 Radionuclide dose calibrator. (a...

Estimation of aquifer radionuclide concentrations by postprocessing of conservative tracer model results

NASA Astrophysics Data System (ADS)

Gedeon, M.; Vandersteen, K.; Rogiers, B.

2012-04-01

Radionuclide concentrations in aquifers represent an important indicator in estimating the impact of a planned surface disposal for low and medium level short-lived radioactive waste in Belgium, developed by the Belgian Agency for Radioactive Waste and Enriched Fissile Materials (ONDRAF/NIRAS), who also coordinates and leads the corresponding research. Estimating aquifer concentrations for individual radionuclides represents a computational challenge because (a) different retardation values are applied to different hydrogeologic units and (b) sequential decay reactions with radionuclides of various sorption characteristics cause long computational times until a steady-state is reached. The presented work proposes a methodology reducing substantially the computational effort by postprocessing the results of a prior non-reactive tracer simulation. These advective transport results represent the steady-state concentration - source flux ratio and the break-through time at each modelling cell. These two variables are further used to estimate the individual radionuclide concentrations by (a) scaling the steady-state concentrations to the source fluxes of individual radionuclides; (b) applying the radioactive decay and ingrowth in a decay chain; (c) scaling the travel time by the retardation factor and (d) applying linear sorption. While all steps except (b) require solving simple linear equations, applying ingrowth of individual radionuclides in decay chains requires solving the differential Bateman equation. This equation needs to be solved once for a unit radionuclide activity at all arrival times found in the numerical grid. The ratios between the parent nuclide activity and the progeny activities are then used in the postprocessing. Results are presented for discrete points and examples of radioactive plume maps are given. These results compare well to the results achieved using a full numerical simulation including the respective chemical reaction processes. Although the proposed method represents a fast way to estimate the radionuclide concentrations without performing timely challenging simulations, its applicability has some limits. The radionuclide source needs to be assumed constant during the period of achieving a steady-state in the model. Otherwise, the source variability of individual radionuclides needs to be modelled using a numerical simulation. However, such a situation only occurs in cases of source variability in a period until steady-state is reached and such a simulation takes a relatively short time. The proposed method enables an effective estimation of individual radionuclide concentrations in the frame of performance assessment of a radioactive waste disposal. Reducing the calculation time to a minimum enables performing sensitivity and uncertainty analyses, testing alternative models, etc. thus enhancing the overall quality of the modelling analysis.

40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2013 CFR

2013-07-01

... maximum contaminant levels for radionuclides. 142.65 Section 142.65 Protection of Environment... Available § 142.65 Variances and exemptions from the maximum contaminant levels for radionuclides. (a)(1) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium...

40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2012 CFR

2012-07-01

... maximum contaminant levels for radionuclides. 142.65 Section 142.65 Protection of Environment... Available § 142.65 Variances and exemptions from the maximum contaminant levels for radionuclides. (a)(1) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium...

40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2014 CFR

2014-07-01

... maximum contaminant levels for radionuclides. 142.65 Section 142.65 Protection of Environment... Available § 142.65 Variances and exemptions from the maximum contaminant levels for radionuclides. (a)(1) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium...

40 CFR 142.65 - Variances and exemptions from the maximum contaminant levels for radionuclides.

Code of Federal Regulations, 2011 CFR

2011-07-01

... maximum contaminant levels for radionuclides. 142.65 Section 142.65 Protection of Environment... Available § 142.65 Variances and exemptions from the maximum contaminant levels for radionuclides. (a)(1) Variances and exemptions from the maximum contaminant levels for combined radium-226 and radium-228, uranium...

21 CFR 892.1420 - Radionuclide test pattern phantom.

Code of Federal Regulations, 2010 CFR

2010-04-01

... 21 Food and Drugs 8 2010-04-01 2010-04-01 false Radionuclide test pattern phantom. 892.1420 Section 892.1420 Food and Drugs FOOD AND DRUG ADMINISTRATION, DEPARTMENT OF HEALTH AND HUMAN SERVICES (CONTINUED) MEDICAL DEVICES RADIOLOGY DEVICES Diagnostic Devices § 892.1420 Radionuclide test pattern phantom...

Radionuclide demonstration of urinary extravasation with ureteral obstruction

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yeh, V.A.; Chiang, L.C.; Meade, R.C.

Two cases of urinary extravasation with ureteral obstruction demonstrated by the radionuclide studies are reported. The value of radionuclide studies in patients with renal transplantation has been reported previously, but studies in patients without transplantation have rarely been described in the literature. Ureteral obstruction may cause urinary extravasation, which may be demonstrated by radionuclide studies even when radiologic studies are inconclusive. In one case, urinary extravasation was detected in the sitting position but not in the supine position. Renal imaging should probably be performed not only with multiple projections but also in different positions.

Activity measurement and effective dose modelling of natural radionuclides in building material.

PubMed

Maringer, F J; Baumgartner, A; Rechberger, F; Seidel, C; Stietka, M

2013-11-01

In this paper the assessment of natural radionuclides' activity concentration in building materials, calibration requirements and related indoor exposure dose models is presented. Particular attention is turned to specific improvements in low-level gamma-ray spectrometry to determine the activity concentration of necessary natural radionuclides in building materials with adequate measurement uncertainties. Different approaches for the modelling of the effective dose indoor due to external radiation resulted from natural radionuclides in building material and results of actual building material assessments are shown. Copyright © 2013 Elsevier Ltd. All rights reserved.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jannik, Tim; Hartman, Larry

During the operational history of Savannah River Site, many different radionuclides have been released from site facilities. However, as shown in this analysis, only a relatively small number of the released radionuclides have been significant contributors to doses to the offsite public. This report is an update to the 2011 analysis, Critical Radionuclide and Pathway Analysis for the Savannah River Site. SRS-based Performance Assessments for E-Area, Saltstone, F-Tank Farm, H-Tank Farm, and a Comprehensive SRS Composite Analysis have been completed. The critical radionuclides and pathways identified in those extensive reports are also detailed and included in this analysis.

WORKER INHALATION DOSE COEFFICIENTS FOR RADIONUCLIDES NOT PREVIOUSLY IDENTIFIED IN ICRP PUBLICATION 68

DOE Office of Scientific and Technical Information (OSTI.GOV)

McLaughlin, David A; Schwahn, Scott O

2011-01-01

While inhalation dose coefficients are provided for about 800 radionuclides in International Commission on Radiological Protection (ICRP) Publication 68, many radionuclides of practical dosimetric interest for facilities such as high-energy proton accelerators are not specifically addressed, nor are organ-specific dose coefficients tabulated. The ICRP Publication 68 methodology is used, along with updated radiological decay data and metabolic data, to identify committed equivalent dose coefficients [hT(50)] and committed effective dose coefficients [e(50)] for radionuclides produced at the Oak Ridge National Laboratory s Spallation Neutron Source.

Production of novel diagnostic radionuclides in small medical cyclotrons.

PubMed

Synowiecki, Mateusz Adam; Perk, Lars Rutger; Nijsen, J Frank W

2018-01-01

The global network of cyclotrons has expanded rapidly over the last decade. The bulk of its industrial potential is composed of small medical cyclotrons with a proton energy below 20 MeV for radionuclides production. This review focuses on the recent developments of novel medical radionuclides produced by cyclotrons in the energy range of 3 MeV to 20 MeV. The production of the following medical radionuclides will be described based on available literature sources: Tc-99 m, I-123, I-124, Zr-89, Cu-64, Ga-67, Ga-68, In-111, Y-86 and Sc-44. Remarkable developments in the production process have been observed in only some cases. More research is needed to make novel radionuclide cyclotron production available for the medical industry.

Paving the way to personalized medicine: production of some theragnostic radionuclides at Brookhaven National Laboratory

DOE Office of Scientific and Technical Information (OSTI.GOV)

Srivastava S. C.

2011-06-06

This paper introduces a relatively novel paradigm that involves specific individual radionuclides or radionuclide pairs that have emissions that allow pre-therapy low-dose imaging plus higher-dose therapy in the same patient. We have made an attempt to sort out and organize a number of such theragnostic radionuclides and radionuclide pairs that may potentially bring us closer to the age-long dream of personalized medicine for performing tailored low-dose molecular imaging (SPECT/CT or PET/CT) to provide the necessary pre-therapy information on biodistribution, dosimetry, the limiting or critical organ or tissue, and the maximum tolerated dose (MTD), etc. If the imaging results then warrantmore » it, it would be possible to perform higher-dose targeted molecular therapy in the same patient with the same radiopharmaceutical. A major problem that remains yet to be fully resolved is the lack of availability, in sufficient quantities, of a majority of the best candidate theragnostic radionuclides in a no-carrier-added (NCA) form. A brief description of the recently developed new or modified methods at BNL for the production of four theragnostic radionuclides, whose nuclear, physical, and chemical characteristics seem to show great promise for personalized cancer therapy are described.« less

Determination of the Distribution and Inventory of Radionuclides within a Savannah River Site Waterway - 13202

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiergesell, R.A.; Phifer, M.A.

2013-07-01

An investigation was conducted to evaluate the radionuclide inventory within the Lower Three Runs (LTR) Integrator Operable Unit (IOU) at the U.S. Department of Energy's (DOE's) Savannah River Site (SRS). The scope of this effort included the analysis of previously existing sampling and analysis data as well as additional stream bed and flood plain sampling and analysis data acquired to delineate horizontal and vertical distributions of the radionuclide as part of the ongoing SRS environmental restoration program, and specifically for the LTR IOU program. While cesium-137 (Cs-137) is the most significant and abundant radionuclide associated with the LTR IOU itmore » is not the only radionuclide, hence the scope included evaluating all radionuclides present and includes an evaluation of inventory uncertainty for use in sensitivity and uncertainty analyses. The scope involved evaluation of the radionuclide inventory in the P-Reactor and R-Reactor cooling water effluent canal systems, PAR Pond (including Pond C) and the flood plain and stream sediment sections of LTR between the PAR Pond Dam and the Savannah River. The approach taken was to examine all of the available Sediment and Sediment/Soil analysis data available along the P- and R-Reactor cooling water re-circulation canal system, the ponds situated along those canal reaches and along the length of LTR below Par Pond dam. By breaking the IOU into a series of sub-components and sub-sections, the mass of contaminated material was estimated and a representative central concentration of each radionuclide was computed for each compartment. The radionuclide inventory associated with each sub-compartment was then aggregated to determine the total radionuclide inventory that represented the full LTR IOU. Of special interest was the inventory of Cs-137 due to its role in contributing to the potential dose to an offsite member of the public. The overall LTR IOU inventory of Cs-137 was determined to be 2.87 E+02 GBq, which is similar to two earlier estimates. This investigation provides an independent, ground-up estimate of Cs-137 inventory in LTR IOU utilizing the most recent field data. (authors)« less

Removal Efficiency of Radioactive Cesium and Iodine Ions by a Flow-Type Apparatus Designed for Electrochemically Reduced Water Production

PubMed Central

Hamasaki, Takeki; Nakamichi, Noboru; Teruya, Kiichiro; Shirahata, Sanetaka

2014-01-01

The Fukushima Daiichi Nuclear Power Plant accident on March 11, 2011 attracted people’s attention, with anxiety over possible radiation hazards. Immediate and long-term concerns are around protection from external and internal exposure by the liberated radionuclides. In particular, residents living in the affected regions are most concerned about ingesting contaminated foodstuffs, including drinking water. Efficient removal of radionuclides from rainwater and drinking water has been reported using several pot-type filtration devices. A currently used flow-type test apparatus is expected to simultaneously provide radionuclide elimination prior to ingestion and protection from internal exposure by accidental ingestion of radionuclides through the use of a micro-carbon carboxymethyl cartridge unit and an electrochemically reduced water production unit, respectively. However, the removability of radionuclides from contaminated tap water has not been tested to date. Thus, the current research was undertaken to assess the capability of the apparatus to remove radionuclides from artificially contaminated tap water. The results presented here demonstrate that the apparatus can reduce radioactivity levels to below the detection limit in applied tap water containing either 300 Bq/kg of 137Cs or 150 Bq/kg of 125I. The apparatus had a removal efficiency of over 90% for all concentration ranges of radio–cesium and –iodine tested. The results showing efficient radionuclide removability, together with previous studies on molecular hydrogen and platinum nanoparticles as reactive oxygen species scavengers, strongly suggest that the test apparatus has the potential to offer maximum safety against radionuclide-contaminated foodstuffs, including drinking water. PMID:25029447

(Workshop on transfer of radionuclides to livestock, Christ Church College-University of Oxford, United Kingdom, September 5--8, 1988): Foreign trip report

DOE Office of Scientific and Technical Information (OSTI.GOV)

Richmond, C.R.

1988-09-30

The traveler participated in the Workshop on the Transfer of Radionuclides to Livestock which was held at the Christ Church College-University of Oxford, September 5-8, 1988. The traveler was a member of the program committee that was made up of representatives from ten countries. In addition, the traveler presented a key invited paper entitled ''Transfer of Radionuclides to Animals --- An Historical Perspective of Work Done in the United States.'' The aim of the workshop was to review current information obtained from both observations and experimental studies on how various parameters can influence the mechanisms of transfer of radionuclides tomore » human food stuffs. These parameters include source and composition of the diet, chemical form of radionuclides, season, agricultural practices, species, strain, and age. The importance and application of countermeasures for reducing the transfer of radionuclides to food stuffs was also considered. The last session of the meeting included summaries and presentations by each session chairman. This was followed by a general discussion by the attendees that was most profitable and stimulating.« less

Radionuclides, radiotracers and radiopharmaceuticals for in vivo diagnosis

NASA Astrophysics Data System (ADS)

Wiebe, Leonard I.

Radioactive tracers for in vivo clinical diagnosis fall within a narrow, strictly-defined set of specifications in respect of their physical properties, chemical and biochemical characteristics, and (approved) medical applications. The type of radioactive decay and physical half-life of the radionuclide are immutable properties which, along with the demands of production and supply, limit the choice of radionuclides used in medicine to only a small fraction of those known to exist. In use, the biochemical and physiological properties of a radiotracer are dictated by the chemical form of the radionuclide. This chemical form may range from elemental, molecular or ionic, to complex compounds formed by coordinate or covalent bonding of the radionuclide to either simple organic or inorganic molecules, or complex macromolecules. Few of the radiotracers which are tested in model systems ever become radiopharmaceuticals in the strictest sense. Radionuclides, radiotracers and radiopharmaceuticals in use are reviewed. Drug legislation and regulations concerning drug manufacture, as well as hospital ethical constraints and legislation concerning unsealed sources of radiation must all be satisfied in order to translate a radiopharmaceutical from the laboratory to clinical use.

Leaching of radionuclides from decaying blueberry leaves: Relative rate independent of concentration

DOE Office of Scientific and Technical Information (OSTI.GOV)

Sheppard, S.C.; Evenden, W.G.

Leaching of radionuclides from decaying vegetation has not been extensively investigated, especially for radionuclides other than {sup 137}Cs. The authors obtained leaves of blueberry (Vaccinium angustifolium {times} V. corymbosum) that contained over 25-fold ranges in Se, Cs, and I concentrations, as well as a small quantity of leaves containing detectable U. All were contaminated by way of root uptake. Leaching took place for a period of 1 yr in the laboratory, using leach water from forest litter. Monthly, measurements were made of the radionuclide contents and decaying leaf dry weights. The data conformed to an exponential decay model with twomore » first-order components. In no case did the relative loss rates vary systematically with the initial tissue radionuclide concentrations. Loss rates decreased in the order Cs > I > U > dry wt. > Se. Because of the low leaching rate of Se relative to the loss of dry weight, decaying litter may actually accumulate elements such as Se. Accumulation of radionuclides in litter could have important implications for lateral transport, recycling, and direct incorporation into edible mushrooms.« less

Radionuclide Retention in Concrete Wasteforms

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wellman, Dawn M.; Jansik, Danielle P.; Golovich, Elizabeth C.

2012-09-24

Assessing long-term performance of Category 3 waste cement grouts for radionuclide encasement requires knowledge of the radionuclide-cement interactions and mechanisms of retention (i.e., sorption or precipitation); the mechanism of contaminant release; the significance of contaminant release pathways; how wasteform performance is affected by the full range of environmental conditions within the disposal facility; the process of wasteform aging under conditions that are representative of processes occurring in response to changing environmental conditions within the disposal facility; the effect of wasteform aging on chemical, physical, and radiological properties; and the associated impact on contaminant release. This knowledge will enable accurate predictionmore » of radionuclide fate when the wasteforms come in contact with groundwater. Data collected throughout the course of this work will be used to quantify the efficacy of concrete wasteforms, similar to those used in the disposal of LLW and MLLW, for the immobilization of key radionuclides (i.e., uranium, technetium, and iodine). Data collected will also be used to quantify the physical and chemical properties of the concrete affecting radionuclide retention.« less

Assimilation and biological turnover of cesium-134, iodine-131, and chromium-51 in brown crickets, Acheta domesticus (L. )

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van Hook, R.I. Jr.; Crossley, D.A. Jr.

1969-01-01

Understanding of radionuclide accumulation by insects requires careful assessment of assimilation and turnover rates. In separate experiments, three radionuclides (/sup 134/Cs, /sup 131/I or /sup 51/Cr) were fed to adult brown crickets for a 24-hr period. The insects were then transferred to nonradioactive food and their whole-body retention measured at 1-hr intervals. The retention of each radionuclide can be described by a sum of two exponential functions, a shorter one related to loss of unassimilated radionuclide from the gut and a longer one describing excretion of assimilated radionuclide from tissues. The shorter components had similar rates (half-time = about 4more » hr) for all three radionuclides, indicating that they were a measure of gut clearance time. Chromium had the lowest assimilation (6%) and cesium the highest (65%). Assimilated /sup 134/Cs and /sup 51/Cr were eliminated at moderate rates (biological half-lives of 62 and 83 hr, respectively) but assimilated /sup 131/I was stored rather than excreted. 18 references, 2 figures, 1 table.« less

ICRP Publication 107. Nuclear decay data for dosimetric calculations.

PubMed

Eckerman, K; Endo, A

2008-01-01

In this report, the Commission provides an electronic database of the physical data needed in calculations of radionuclide-specific protection and operational quantities. This database supersedes the data of Publication 38 (ICRP, 1983), and will be used in future ICRP publications of dose coefficients for the intake of or exposure to radionuclides in the workplace and the environment.The database contains information on the half-lives, decay chains, and yields and energies of radiations emitted in nuclear transformations of 1252 radionuclides of 97 elements. The CD accompanying the publication provides electronic access to complete tables of the emitted radiations, as well as the beta and neutron spectra. The database has been constructed such that user-developed software can extract the data needed for further calculations of a radionuclide of interest. A Windows-based application is provided to display summary information on a user-specified radionuclide, as well as the general characterisation of the nuclides contained in the database. In addition, the application provides a means by which the user can export the emissions of a specified radionuclide for use in subsequent calculations.

Vesicoureteral reflux in asymptomatic siblings of patients with known reflux: radionuclide cystography

DOE Office of Scientific and Technical Information (OSTI.GOV)

Van den Abbeele, A.D.; Treves, S.T.; Lebowitz, R.L.

1987-01-01

The familial nature of vesicoureteral reflux among siblings of patients with vesicoureteral reflux has been reported to be from 8% to 32%. These included both symptomatic and asymptomatic siblings. The incidence of vesicoureteral reflux in asymptomatic siblings, however, has not been studied extensively. Sixty asymptomatic siblings of patients known to have vesicoureteral reflux were studied with radionuclide voiding cystography. Their ages ranged from 2 months to 15 years (mean, 4.2 years). Vesicoureteral reflux was detected in 27 of 60 (45%) of the siblings. Vesicoureteral reflux was unilateral in 15 and bilateral in 12 of the siblings. Radionuclide cystography is moremore » sensitive than radiographic cystography and results in a very low radiation dose to the patient. The gonadal dose with radionuclide cystography is only 1.0 to 2.0 mrads. Because of these features, radionuclide cystography is a nearly ideal technique for the diagnosis of vesicoureteral reflux in siblings of patients with known vesicoureteral reflux. All siblings (symptomatic or asymptomatic) of patients with known vesicoureteral reflux should have a screening radionuclide cystography.« less

Bioremediation: a genuine technology to remediate radionuclides from the environment

PubMed Central

Prakash, Dhan; Gabani, Prashant; Chandel, Anuj K; Ronen, Zeev; Singh, Om V

2013-01-01

Summary Radionuclides in the environment are a major human and environmental health concern. Like the Chernobyl disaster of 1986, the Fukushima Daiichi nuclear disaster in 2011 is once again causing damage to the environment: a large quantity of radioactive waste is being generated and dumped into the environment, and if the general population is exposed to it, may cause serious life-threatening disorders. Bioremediation has been viewed as the ecologically responsible alternative to environmentally destructive physical remediation. Microorganisms carry endogenous genetic, biochemical and physiological properties that make them ideal agents for pollutant remediation in soil and groundwater. Attempts have been made to develop native or genetically engineered (GE) microbes for the remediation of environmental contaminants including radionuclides. Microorganism-mediated bioremediation can affect the solubility, bioavailability and mobility of radionuclides. Therefore, we aim to unveil the microbial-mediated mechanisms for biotransformation of radionuclides under various environmental conditions as developing strategies for waste management of radionuclides. A discussion follows of ‘-omics’-integrated genomics and proteomics technologies, which can be used to trace the genes and proteins of interest in a given microorganism towards a cell-free bioremediation strategy. PMID:23617701

Biodegradation of PuEDTA and Impacts on Pu Mobility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Xun, Luying; Bolton, Jr., Harvey

Ethylenediaminetetraacetate (EDTA) and nitrilotriacetate (NTA) are synthetic chelating agents, which can form strong water-soluble complexes with radionuclides and metals and has been used to decontaminate and process nuclear materials. Synthetic chelating agents were co-disposed with radionuclides (e.g., 60Co, Pu) and heavy metals enhancing their transport in the subsurface. An understanding of EDTA biodegradation is essential to help mitigate enhanced radionuclide transport by EDTA. The objective of this research is to develop fundamental data on factors that govern the biodegradation of radionuclide-EDTA. These factors include the dominant EDTA aqueous species, the biodegradation of various metal-EDTA complexes, the uptake of various metal-EDTAmore » complexes into the cell, the distribution and mobility of the radionuclide during and after EDTA biodegradation, and the enzymology and genetics of EDTA biodegradation.« less

System and method for assaying a radionuclide

DOEpatents

Cadieux, James R; King, III, George S; Fugate, Glenn A

2014-12-23

A system for assaying a radionuclide includes a liquid scintillation detector, an analyzer connected to the liquid scintillation detector, and a delay circuit connected to the analyzer. A gamma detector and a multi-channel analyzer are connected to the delay circuit and the gamma detector. The multi-channel analyzer produces a signal reflective of the radionuclide in the sample. A method for assaying a radionuclide includes selecting a sample, detecting alpha or beta emissions from the sample with a liquid scintillation detector, producing a first signal reflective of the alpha or beta emissions, and delaying the first signal a predetermined time. The method further includes detecting gamma emissions from the sample, producing a second signal reflective of the gamma emissions, and combining the delayed first signal with the second signal to produce a third signal reflective of the radionuclide.

Determination and maintenance of DE minimis risk for migration of residual tritium (3H) from the 1969 Project Rulison nuclear test to nearby hydraulically fractured natural gas wells.

PubMed

Daniels, Jeffrey I; Chapman, Jenny B

2013-05-01

The Project Rulison underground nuclear test was a proof-of-concept experiment that was conducted under the Plowshare Program in 1969 in the Williams Fork Formation of the Piceance Basin in west-central Colorado. Today, commercial production of natural gas is possible from low permeability, natural gas bearing formations like that of the Williams Fork Formation using modern hydraulic fracturing techniques. With natural gas exploration and production active in the Project Rulison area, this human health risk assessment was performed in order to add a human health perspective for site stewardship. Tritium (H) is the radionuclide of concern with respect to potential induced migration from the test cavity leading to subsequent exposure during gas-flaring activities. This analysis assumes gas flaring would occur for up to 30 d and produce atmospheric H activity concentrations either as low as 2.2 × 10 Bq m (6 × 10 pCi m) from the minimum detectable activity concentration in produced water or as high as 20.7 Bq m (560 pCi m), which equals the highest atmospheric measurement reported during gas-flaring operations conducted at the time of Project Rulison. The lifetime morbidity (fatal and nonfatal) cancer risks calculated for adults (residents and workers) and children (residents) from inhalation and dermal exposures to such activity concentrations are all below 1 × 10 and considered de minimis. The implications for monitoring production water for conforming health-protective, risk-based action levels also are examined.

The enrichment behavior of natural radionuclides in pulverized oil shale-fired power plants.

PubMed

Vaasma, Taavi; Kiisk, Madis; Meriste, Tõnis; Tkaczyk, Alan Henry

2014-12-01

The oil shale industry is the largest producer of NORM (Naturally Occurring Radioactive Material) waste in Estonia. Approximately 11-12 million tons of oil shale containing various amounts of natural radionuclides is burned annually in the Narva oil shale-fired power plants, which accounts for approximately 90% of Estonian electricity production. The radionuclide behavior characteristics change during the fuel combustion process, which redistributes the radionuclides between different ash fractions. Out of 24 operational boilers in the power plants, four use circulating fluidized bed (CFB) technology and twenty use pulverized fuel (PF) technology. Over the past decade, the PF boilers have been renovated, with the main objective to increase the efficiency of the filter systems. Between 2009 and 2012, electrostatic precipitators (ESP) in four PF energy blocks were replaced with novel integrated desulphurization technology (NID) for the efficient removal of fly ash and SO2 from flue gases. Using gamma spectrometry, activity concentrations and enrichment factors for the (238)U ((238)U, (226)Ra, (210)Pb) and (232)Th ((232)Th, (228)Ra) family radionuclides as well as (40)K were measured and analyzed in different PF boiler ash fractions. The radionuclide activity concentrations in the ash samples increased from the furnace toward the back end of the flue gas duct. The highest values in different PF boiler ash fractions were in the last field of the ESP and in the NID ash, where radionuclide enrichment factors were up to 4.2 and 3.3, respectively. The acquired and analyzed data on radionuclide activity concentrations in different PF boiler ashes (operating with an ESP and a NID system) compared to CFB boiler ashes provides an indication that changes in the fuel (oil shale) composition and boiler working parameters, as well as technological enhancements in Estonian oil shale fired power plants, have had a combined effect on the distribution patterns of natural radionuclides in the oil shale combustion products. Copyright © 2014 Elsevier Ltd. All rights reserved.

Assessment of radionuclide databases in CAP88 mainframe version 1.0 and Windows-based version 3.0.

PubMed

LaBone, Elizabeth D; Farfán, Eduardo B; Lee, Patricia L; Jannik, G Timothy; Donnelly, Elizabeth H; Foley, Trevor Q

2009-09-01

In this study the radionuclide databases for two versions of the Clean Air Act Assessment Package-1988 (CAP88) computer model were assessed in detail. CAP88 estimates radiation dose and the risk of health effects to human populations from radionuclide emissions to air. This program is used by several U.S. Department of Energy (DOE) facilities to comply with National Emission Standards for Hazardous Air Pollutants regulations. CAP88 Mainframe, referred to as version 1.0 on the U.S. Environmental Protection Agency Web site (http://www.epa.gov/radiation/assessment/CAP88/), was the very first CAP88 version released in 1988. Some DOE facilities including the Savannah River Site still employ this version (1.0) while others use the more user-friendly personal computer Windows-based version 3.0 released in December 2007. Version 1.0 uses the program RADRISK based on International Commission on Radiological Protection Publication 30 as its radionuclide database. Version 3.0 uses half-life, dose, and risk factor values based on Federal Guidance Report 13. Differences in these values could cause different results for the same input exposure data (same scenario), depending on which version of CAP88 is used. Consequently, the differences between the two versions are being assessed in detail at Savannah River National Laboratory. The version 1.0 and 3.0 database files contain 496 and 838 radionuclides, respectively, and though one would expect the newer version to include all the 496 radionuclides, 35 radionuclides are listed in version 1.0 that are not included in version 3.0. The majority of these has either extremely short or long half-lives or is no longer in production; however, some of the short-lived radionuclides might produce progeny of great interest at DOE sites. In addition, 122 radionuclides were found to have different half-lives in the two versions, with 21 over 3 percent different and 12 over 10 percent different.

Selected bibliography of terrestrial freshwater, and marine radiation ecology

DOE Office of Scientific and Technical Information (OSTI.GOV)

Schultz, V.; Whicker, F.W.

1975-01-01

An extensive bibliography is presented of publications related to field or laboratory studies of wild species of plants and animals with respect to radiation effects or metabolic studies involving radionuclides. The references are listed under the following headings: status and needs of radiation ecology; environmental radioactivity; radionuclide concentration; ionizing radiation effects; techniques utilizing radionuclides and ionizing radiation in ecology; measurement of ionizing radiation; peaceful uses of atomic energy; waste disposal; nuclear testing and ecological consequences of a nuclear war; glossaries, standards, and licensing procedures; reviews of radionuclides in the environment; and sources of information. (HLW)

Drifter-based estimate of the 5 year dispersal of Fukushima-derived radionuclides

NASA Astrophysics Data System (ADS)

Rypina, I. I.; Jayne, S. R.; Yoshida, S.; Macdonald, A. M.; Buesseler, K.

2014-11-01

Employing some 40 years of North Pacific drifter-track observations from the Global Drifter Program database, statistics defining the horizontal spread of radionuclides from Fukushima nuclear power plant into the Pacific Ocean are investigated over a time scale of 5 years. A novel two-iteration method is employed to make the best use of the available drifter data. Drifter-based predictions of the temporal progression of the leading edge of the radionuclide distribution are compared to observed radionuclide concentrations from research surveys occupied in 2012 and 2013. Good agreement between the drifter-based predictions and the observations is found.

Selection of plants for phytoremediation of soils contaminated with radionuclides

DOE Office of Scientific and Technical Information (OSTI.GOV)

Entry J.A.; Vance, N.C.; Watrud, L.S.

1996-12-31

Remediation of soil contaminated with radionuclides typically requires that soil be removed from the site and treated with various dispersing and chelating chemicals. Numerous studies have shown that radionuclides are generally not leached from the top 0.4 meters of soil, where plant roots actively accumulate elements. Restoration of large areas of land contaminated with low levels of radionuclides may be feasible using phytoremediation. Criteria for the selection of plants for phytoremediation, molecular approaches to increase radio nuclide uptake, effects of cultural practices on uptake and assessment of environmental effects of phytoremediation will be discussed.

Atmospheric emission of 137Cs82 from Beloyarsk nuclear power plant

NASA Astrophysics Data System (ADS)

Kolotkov, G. A.

2018-01-01

Citing Beloyarsk nuclear power plant (Russia) as an example, the problem of remote detection of radioactivity in the atmospheric pollution is examined. The comparative analysis of injected radionuclides into the atmosphere from the nuclear power plant with advanced fast neutron reactor is carried out. The main radionuclides throw out into the atmosphere from the nuclear power plant are beta-radionuclides. The secondary and tertiary spectra of beta-electrons decay for artificial radionuclide 137Cs82 is calculated, using Spencer-Fano’s equation. The averaged parameters of initial beta - electrons generated by 137Cs82 decay in the atmosphere is calculated.

Radiological assessment. A textbook on environmental dose analysis

DOE Office of Scientific and Technical Information (OSTI.GOV)

Till, J.E.; Meyer, H.R.

1983-09-01

Radiological assessment is the quantitative process of estimating the consequences to humans resulting from the release of radionuclides to the biosphere. It is a multidisciplinary subject requiring the expertise of a number of individuals in order to predict source terms, describe environmental transport, calculate internal and external dose, and extrapolate dose to health effects. Up to this time there has been available no comprehensive book describing, on a uniform and comprehensive level, the techniques and models used in radiological assessment. Radiological Assessment is based on material presented at the 1980 Health Physics Society Summer School held in Seattle, Washington. Themore » material has been expanded and edited to make it comprehensive in scope and useful as a text. Topics covered include (1) source terms for nuclear facilities and Medical and Industrial sites; (2) transport of radionuclides in the atmosphere; (3) transport of radionuclides in surface waters; (4) transport of radionuclides in groundwater; (5) terrestrial and aquatic food chain pathways; (6) reference man; a system for internal dose calculations; (7) internal dosimetry; (8) external dosimetry; (9) models for special-case radionuclides; (10) calculation of health effects in irradiated populations; (11) evaluation of uncertainties in environmental radiological assessment models; (12) regulatory standards for environmental releases of radionuclides; (13) development of computer codes for radiological assessment; and (14) assessment of accidental releases of radionuclides.« less

Radionuclides in the soil around the largest coal-fired power plant in Serbia: radiological hazard, relationship with soil characteristics and spatial distribution.

PubMed

Ćujić, Mirjana; Dragović, Snežana; Đorđević, Milan; Dragović, Ranko; Gajić, Boško; Miljanić, Šćepan

2015-07-01

Primordial radionuclides, (238)U, (232)Th and (40)K were determined in soil samples collected at two depths (0-10 and 10-20 cm) in the vicinity of the largest coal-fired power plant in Serbia, and their spatial distribution was analysed using ordinary kriging. Mean values of activity concentrations for these depths were 50.7 Bq kg(-1) for (238)U, 48.7 Bq kg(-1) for (232)Th and 560 Bq kg(-1) for (40)K. Based on the measured activity concentrations, the radiological hazard due to naturally occurring radionuclides in soil was assessed. The value of the mean total absorbed dose rate was 76.3 nGy h(-1), which is higher than the world average. The annual effective dose due to these radionuclides ranged from 51.4 to 114.2 μSv. Applying cluster analysis, correlations between radionuclides and soil properties were determined. The distribution pattern of natural radionuclides in the environment surrounding the coal-fired power plant and their enrichment in soil at some sampling sites were in accordance with dispersion models of fly ash emissions. From the results obtained, it can be concluded that operation of the coal-fired power plant has no significant negative impact on the surrounding environment with regard to the content of natural radionuclides.

Assessment of the vertical distribution of natural radionuclides in a mineralized uranium area in south-west Spain.

PubMed

Blanco Rodríguez, P; Vera Tomé, F; Lozano, J C

2014-01-01

Low-level alpha spectrometry techniques using semiconductor detectors (PIPS) and liquid scintillation (LKB Quantulus 1220™) were used to determine the activity concentration of (238)U, (234)U, (230)Th, (226)Ra, (232)Th, and (210)Pb in soil samples. The soils were collected from an old disused uranium mine located in southwest Spain. The soils were sampled from areas with different levels of influence from the installation and hence had different levels of contamination. The vertical profiles of the soils (down to 40 cm depth) were studied in order to evaluate the vertical distribution of the natural radionuclides. To determine the origin of these natural radionuclides the Enrichment Factor was used. Also, study of the activity ratios between radionuclides belonging to the same radioactive series allowed us to assess the different types of behaviors of the radionuclides involved. The vertical profiles for the radionuclide members of the (238)U series were different at each sampling point, depending on the level of influence of the installation. However, the profiles of each point were similar for the long-lived radionuclides of the (238)U series ((238)U, (234)U, (230)Th, and (226)Ra). Moreover, a major imbalance was observed between (210)Pb and (226)Ra in the surface layer, due to (222)Rn exhalation and the subsequent surface deposition of (210)Pb. Copyright © 2013 Elsevier Ltd. All rights reserved.

A BENCHMARKING ANALYSIS FOR FIVE RADIONUCLIDE VADOSE ZONE MODELS (CHAIN, MULTIMED_DP, FECTUZ, HYDRUS, AND CHAIN 2D) IN SOIL SCREENING LEVEL CALCULATIONS

EPA Science Inventory

Five radionuclide vadose zone models with different degrees of complexity (CHAIN, MULTIMED_DP, FECTUZ, HYDRUS, and CHAIN 2D) were selected for use in soil screening level (SSL) calculations. A benchmarking analysis between the models was conducted for a radionuclide (99Tc) rele...

Radiation Doses to Members of the U.S. Population from Ubiquitous Radionuclides in the Body: Part 3, Results, Variability, and Uncertainty

DOE Office of Scientific and Technical Information (OSTI.GOV)

Watson, David J.; Strom, Daniel J.

This paper is part three of a three-part series investigating annual effective doses to residents of the United States from intakes of ubiquitous radionuclides, including radionuclides occurring naturally, radionuclides whose concentrations are technologically enhanced, and anthropogenic radionuclides. The radionuclides of interest are the 238U series (14 nuclides), the actinium series (headed by 235U; 11 nuclides), and the 232Th series (11 nuclides); primordial radionuclides 87Rb and 40K; cosmogenic and fallout radionuclides 14C and 3H; and purely anthropogenic radionuclides 137Cs-137mBa, 129I and 90Sr-90Y. This series of papers explicitly excludes intakes from inhaling 222Rn, 220Rn, and their short-lived decay products; it also excludesmore » intakes of radionuclides in occupational and medical settings. Part one reviewed, summarized, characterized, and grouped all published and some unpublished data for U.S. residents on ubiquitous radionuclide concentrations in tissues and organs. Part two described the methods used to organize the data collected in part one and segregate it into the ages and genders defined by the study, imputed missing values from the existing data, apportioned activity in bone, and imputed activity in hollow organ contents and the remainder of the body. This paper estimates equivalent doses to target tissues from source regions and maps target tissues to lists of tissues with International Commission on Radiation Protection (ICRP) tissue-weighting factors or to surrogate tissue regions when there is no direct match. Effective doses, using ICRP tissue-weighting factors recommended in 1977, 1990, and 2007, are then calculated, and an upper bound of variability of the effective dose is estimated by calculating the average coefficients of variation (CV), assuming all variance is due to variability. Most of the data were for adult males, whose average annual effective dose is estimated to be 337 μSv (CV = 0.65, geometric mean = 283 μSv, geometric standard deviation sG = 1.81) using 2007 ICRP tissue-weighting factors. This result is between the National Council on Radiation Protection & Measurements’ 1987 estimate of 390 μSv (using 1977 wTs) and its 2009 estimate of 285 μSv (using 2007 wTs) and is higher than the United Nations Scientific Committee on the Effects of Atomic Radiation’s 2000 estimate of 310 μSv (using 1990 wTs). The methods and software developed for this project are sufficiently detailed and sufficiently general to be usable with autopsy data from any or all countries.« less

Distribution coefficients (Kd's) for use in risk assessment models of the Kara Sea.

PubMed

Carroll, J; Boisson, F; Teyssie, J L; King, S E; Krosshavn, M; Carroll, M L; Fowler, S W; Povinec, P P; Baxter, M S

1999-07-01

As a prerequisite for most evaluations of radionuclide transport pathways in marine systems, it is necessary to obtain basic information on the sorption potential of contaminants onto particulate matter. Kd values for use in modeling radionuclide dispersion in the Kara Sea have been determined as part of several international programs addressing the problem of radioactive debris residing in Arctic Seas. Field and laboratory Kd experiments were conducted for the following radionuclides associated with nuclear waste: americium, europium, plutonium, cobalt, cesium and strontium. Emphasis has been placed on two regions in the Kara Sea: (i) the Novaya Zemlya Trough (NZT) and (ii) the mixing zones of the Ob and Yenisey Rivers (RMZ). Short-term batch Kd experiments were performed at-sea on ambient water column samples and on samples prepared both at-sea and in the laboratory by mixing filtered bottom water with small amounts of surficial bottom sediments (particle concentrations in samples = 1-30 mg/l). Within both regions, Kd values for individual radionuclides vary over two to three orders of magnitude. The relative particle affinities for radionuclides in the two regions are americium approximately equal to europium > plutonium > cobalt > cesium > strontium. The values determined in this study agree with minimum values given in the IAEA Technical Report [IAEA, 1985. Sediment Kd's and Concentration Factors for Radionuclides in the Marine Environment. Technical Report No. 247. International Atomic Energy Agency, Vienna.]. Given the importance of Kd's in assessments of critical transport pathways for radionuclide contaminants, we recommend that Kd ranges of values for specific elements rather than single mean values be incorporated into model simulations of radionuclide dispersion.

GHSI EMERGENCY RADIONUCLIDE BIOASSAY LABORATORY NETWORK - SUMMARY OF THE SECOND EXERCISE.

PubMed

Li, Chunsheng; Bartizel, Christine; Battisti, Paolo; Böttger, Axel; Bouvier, Céline; Capote-Cuellar, Antonio; Carr, Zhanat; Hammond, Derek; Hartmann, Martina; Heikkinen, Tarja; Jones, Robert L; Kim, Eunjoo; Ko, Raymond; Koga, Roberto; Kukhta, Boris; Mitchell, Lorna; Morhard, Ryan; Paquet, Francois; Quayle, Debora; Rulik, Petr; Sadi, Baki; Sergei, Aleksanin; Sierra, Inmaculada; de Oliveira Sousa, Wanderson; Szab, Gyula

2017-05-01

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO Radiation Emergency Medical Preparedness and Assistance Network and the IAEA Response and Assistance Network, to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides (90Sr, 106Ru, 137Cs, and 239Pu). Laboratories were required to submit their reports within 72 h following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two-third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

GHSI Emergency Radionuclide Bioassay Laboratory Network - Summary of the Second Exercise

PubMed Central

Li, Chunsheng; Bartizel, Christine; Battisti, Paolo; Böttger, Axel; Bouvier, Céline; Capote-Cuellar, Antonio; Carr, Zhanat; Hammond, Derek; Hartmann, Martina; Heikkinen, Tarja; Jones, Robert L.; Kim, Eunjoo; Ko, Raymond; Koga, Roberto; Kukhta, Boris; Mitchell, Lorna; Morhard, Ryan; Paquet, Francois; Quayle, Debora; Rulik, Petr; Sadi, Baki; Sergei, Aleksanin; Sierra, Inmaculada; de Oliveira Sousa, Wanderson; Szabó, Gyula

2017-01-01

The Global Health Security Initiative (GHSI) established a laboratory network within the GHSI community to develop collective surge capacity for radionuclide bioassay in response to a radiological or nuclear emergency as a means of enhancing response capability, health outcomes and community resilience. GHSI partners conducted an exercise in collaboration with the WHO REMPAN (Radiation Emergency Medical Preparedness and Assistance Network) and the IAEA RANET (Response and Assistance Network), to test the participating laboratories (18) for their capabilities in in vitro assay of biological samples, using a urine sample spiked with multiple high-risk radionuclides (90Sr, 106Ru, 137Cs, and 239Pu). Laboratories were required to submit their reports within 72 hours following receipt of the sample, using a pre-formatted template, on the procedures, methods and techniques used to identify and quantify the radionuclides in the sample, as well as the bioassay results with a 95% confidence interval. All of the participating laboratories identified and measured all or some of the radionuclides in the sample. However, gaps were identified in both the procedures used to assay multiple radionuclides in one sample, as well as in the methods or techniques used to assay specific radionuclides in urine. Two third of the participating laboratories had difficulties in determining all the radionuclides in the sample. Results from this exercise indicate that challenges remain with respect to ensuring that results are delivered in a timely, consistent and reliable manner to support medical interventions. Laboratories within the networks are encouraged to work together to develop and maintain collective capabilities and capacity for emergency bioassay, which is an important component of radiation emergency response. PMID:27574317

Dating sediment cores from Hudson River marshes

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robideau, R.; Bopp, R.F.

1993-03-01

There are several methods for determining sediment accumulation rates in the Hudson River estuary. One involves the analysis of the concentration of certain radionuclides in sediment core sections. Radionuclides occur in the Hudson River as a result of: natural sources, fallout from nuclear weapons testing and low level aqueous releases from the Indian Point Nuclear Power Facility. The following radionuclides have been studied in the authors work: Cesium-137, which is derived from global fallout that started in the 1950's and has peaked in 1963. Beryllium-7, a natural radionuclide with a 53 day half-life and found associated with very recently depositedmore » sediments. Another useful natural radionuclide is Lead-210 derived from the decay of Radon-222 in the atmosphere. Lead-210 has a half-life of 22 years and can be used to date sediments up to about 100 years old. In the Hudson River, Cobalt-60 is a marker for Indian Point Nuclear Reactor discharges. The author's research involved taking sediment core samples from four sites in the Hudson River Estuarine Research Reserve areas. These core samples were sectioned, dried, ground and analyzed for the presence of radionuclides by the method of gamma-ray spectroscopy. The strength of each current pulse is proportional to the energy level of the gamma ray absorbed. Since different radionuclides produce gamma rays of different energies, several radionuclides can be analyzed simultaneously in each of the samples. The data obtained from this research will be compared to earlier work to obtain a complete chronology of sediment deposition in these Reserve areas of the river. Core samples may then by analyzed for the presence of PCB's, heavy metals and other pollutants such as pesticides to construct a pollution history of the river.« less

SU-E-T-666: Radionuclides and Activity of the Patient Apertures Used in a Proton Beam of Wobbling System

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wang, B.Y.; Chen, H.H.; Tsai, H.Y.

2015-06-15

Purpose: To identify the radionuclides and quantify the activity of the patient apertures used in a 190-MeV proton beam of wobbling system. Methods: A proton beam of wobbling system in the first proton center in Taiwan, Chang Gung Memorial Hospital at Linkou, was used to bombard the patient apertures. The patient aperture was composed of 60.5 % copper, 39.4 % Zinc, 0.05 % iron, 0.05 % lead. A protable high-purity germanium (HPGe) coaxial detector was used to measure the spectra of the induced nuclides of patient apertures. The analysis of the spectra and the identification of the radionuclides were preliminarilymore » operated by the Nuclide Navigator III Master Library. On the basis of the results by Nuclide Navigator III Master Library, we manually selected the reliable nuclides by the gamma-ray energies, branching ratio, and half life. In the spectra, we can quantify the activity of radionuclides by the Monte Carlo efficiency transfer method. Results: In this study, the radioisotopes activated in patient apertures by the 190-MeV proton beam were divided into two categories. The first category is long half-life radionuclides, such as Co-56 (half life, 77.3 days). Other radionuclides of Cu-60, Cu-61, Cu-62, Cu-66, and Zn-62 have shorter half life. The radionuclide of Cu-60 had the highest activity. From calculation with the efficiency transfer method, the deviations between the computed results and the measured efficiencies were mostly within 10%. Conclusion: To identify the radionuclides and quantify the activity helps us to estimate proper time intervals for cooling the patient apertures. This study was supported by the grants from the Chang Gung Memorial Hospital (CMRPD1C0682)« less

Atmospheric Transport Modelling confining potential source location of East-Asian radionuclide detections in May 2010

NASA Astrophysics Data System (ADS)

Ross, J. Ole; Ceranna, Lars

2016-04-01

The radionuclide component of the International Monitoring System (IMS) to verify compliance with the Comprehensive Nuclear-Test-Ban Treaty (CTBT) is in place to detect tiny traces of fission products from nuclear explosions in the atmosphere. The challenge for the interpretation of IMS radionuclide data is to discriminate radionuclide sources of CTBT relevance against emissions from nuclear facilities. Remarkable activity concentrations of Ba/La-140 occurred at the IMS radionuclide stations RN 37 (Okinawa) and RN 58 (Ussurysk) mid of May 2010. In those days also an elevated Xe-133 level was measured at RN 38 (Takasaki). Additional regional measurements of radioxenon were reported in the press and further analyzed in various publications. The radionuclide analysis gives evidence for the presence of a nuclear fission source between 10 and 12 May 2010. Backward Atmospheric Transport Modelling (ATM) with HYSPLIT driven by 0.2° ECMWF meteorological data for the IMS samples indicates that, assuming a single source, a wide range of source regions is possible including the Korean Peninsula, the Sea of Japan (East Sea), and parts of China and Russia. Further confinement of the possible source location can be provided by atmospheric backtracking for the assumed sampling periods of the reported regional xenon measurements. New studies indicate a very weak seismic event at the DPRK test site on early 12 May 2010. Forward ATM for a pulse release caused by this event shows fairly good agreement with the observed radionuclide signature. Nevertheless, the underlying nuclear fission scenario remains quite unclear and speculative even if assuming a connection between the waveform and the radionuclide event.

Radioactivity in mushrooms: a health hazard?

PubMed

Guillén, J; Baeza, A

2014-07-01

Mushrooms are a complementary foodstuff and considered to be consumed locally. The demand for mushrooms has increased in recent years, and the mushroom trade is becoming global. Mushroom origin is frequently obscured from the consumer. Mushrooms are considered excellent bioindicators of environmental pollution. The accumulation of radionuclides by mushrooms, which are then consumed by humans or livestock, can pose a radiological hazard. Many studies have addressed the radionuclide content in mushrooms, almost exclusively the radiocaesium content. There is a significant lack of data about their content from some of the main producer countries. An exhaustive review was carried out in order to identify which radionuclide might constitute a health hazard, and the factors conditioning it. Regulatory values for the different radionuclides were used. The worldwide range for radiocaesium, (226)Ra, (210)Pb, and (210)Po surpasses those values. Appropriate radiological protection requires that the content of those radionuclides in mushrooms should be monitored. Copyright © 2013 Elsevier Ltd. All rights reserved.

Radionuclide transport in the "sediments - water - plants" system of the water bodies at the Semipalatinsk test site.

PubMed

Aidarkhanova, A K; Lukashenko, S N; Larionova, N V; Polevik, V V

2018-04-01

This paper provides research data on levels and character of radionuclide contamination distribution in the «sediments- water - plants » system of objects of the Semipalatinsk test site (STS). As the research objects there were chosen water bodies of man-made origin which located at the territory of "Experimental Field", "Balapan", "Telkem" and "Sary-Uzen" testing sites. For research the sampling of bottom sediments, water, lakeside and water plants was taken. Collected samples were used to determine concentration of anthropogenic radionuclides 90 Sr, 239+240 Pu, 241 Am, 137 Cs. The distribution coefficient (K d ) was calculated as the ratio of the content of radionuclides in the sediments to the content in water, and the concentration ratio (F V ) was calculated as the ratio of radionuclide content in plants to the content in sediments or soil. Copyright © 2018 Elsevier Ltd. All rights reserved.

Calibration of the NPL secondary standard radionuclide calibrator for 32P, 89Sr and 90Y

NASA Astrophysics Data System (ADS)

Woods, M. J.; Munster, A. S.; Sephton, J. P.; Lucas, S. E. M.; Walsh, C. Paton

1996-02-01

Pure beta particle emitting radionuclides have many therapeutic applications in nuclear medicine. The response of the NPL secondary standard radionuclide calibrator to 32P, 89Sr and 90Y has been measured using accurately calibrated solutions. For this purpose, high efficiency solid sources were prepared gravimetrically from dilute solutions of each radionuclide and assayed in a 4π proportional counter; the source activities were determined using known detection efficiency factors. Measurements were made of the current response (pA/MBq) of the NPL secondary standard radionuclide calibrator using the original concentrated solutions. Calibration figures have been derived for 2 and 5 ml British Standard glass ampoules and Amersham International plc P6 vials. Volume correction factors have also been determined. Gamma-ray emitting contaminants can have a disproportionate effect on the calibrator response and particular attention has been paid to this.

Inorganic resins for clinical use of .sup.213Bi generators

DOEpatents

DePaoli, David W [Knoxville, TN; Hu, Michael Z [Knoxville, TN; Mirzadeh, Saed [Knoxville, TN; Clavier, John W [Elizabethton, TN

2011-03-29

Applicant's invention is a radionuclide generator resin material for radiochemical separation of daughter radionuclides, particularly .sup.213Bi, from a solution of parental radionuclides, the resin material capable of providing clinical quantities of .sup.213Bi of at least 20-mCi, wherein the resin material comprises a silica-based structure having at least one bifunctional ligand covalently attached to the surface of the silica-based structure. The bifunctional ligand comprises a chemical group having desirable surface functionality to enable the covalent attachment of the bifunctional ligand thereon the surface of the structure and the bifunctional ligand further comprises a second chemical group capable of binding and holding the parental radionuclides on the resin material while allowing the daughter radionuclides to elute off the resin material. The bifunctional ligand has a carbon chain with a limited number of carbons to maintain radiation stability of the resin material.

Monitored Attenuation of Inorganic Contaminants in Ground Water Volume 2 – Assessment for Non-Radionuclides Including Arsenic, Cadmium, Chromium, Copper, Lead, Nickel, Nitrate, Perchlorate, and Selenium

EPA Science Inventory

This document represents the second volume of a set of three volumes that address the technical basis and requirements for assessing the potential applicability of MNA as part of a ground-water remedy for plumes with non-radionuclide and/or radionuclide inorganic contaminants. V...

Laboratory Training Manual on the Use of Radionuclides and Radiation in Animal Research, Third Edition.

ERIC Educational Resources Information Center

International Atomic Energy Agency, Vienna (Austria).

This publication is written for those researchers who are interested in the use of radionuclides and radiation in the animal science field. Part I presents topics intended to provide the theoretical base of radionuclides which is important in order to design an experiment for drawing maximum information from it. The topics included in this…

Vegetation fires, smoke emissions, and dispersion of radionuclides in the chernobyl exclusion zone

Treesearch

Wei Min Hao; Oleg O. Bondarenko; Sergiy Zibtsev; Diane Hutton

2009-01-01

The accident of the Chernobyl nuclear power plant (ChNPP) in 1986 was probably the worst environmental disaster in the past 30 years. The fallout and accumulation of radionuclides in the soil and vegetation could have long-term impacts on the environment. Radionuclides released during large, catastrophic vegetation fires could spread to continental Europe, Scandinavia...

Natural Radionuclide Activity Concentrations In Spas Of Argentina

DOE Office of Scientific and Technical Information (OSTI.GOV)

Gnoni, G.; Czerniczyniec, M.; Canoba, A.

2008-08-07

Geothermal waters have been used on a large scale for bathing, drinking and medical purposes. These waters can contain natural radionuclides that may increase the exposure to people. In this work the most important natural radionuclide activity concentrations in different thermal spas of Argentina were measured to characterize waters and to evaluate the exposure of workers and members of the public.

77 FR 16547 - Radionuclide National Emission Standards for Hazardous Air Pollutants; Notice of Construction...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-03-21

... Creek In-Situ Recovery Project. The holding ponds at the Lost Creek facility are subject to 40 CFR part... in 2011 by EPA Region 8 for the construction or modification of sources subject to the Radionuclide... Provisions to the Radionuclide NESHAP in 40 CFR part 61, subpart A, require a source owner or operator to...

National low-level waste management program radionuclide report series, Volume 15: Uranium-238

DOE Office of Scientific and Technical Information (OSTI.GOV)

Adams, J.P.

1995-09-01

This report, Volume 15 of the National Low-Level Waste Management Program Radionuclide Report Series, discusses the radiological and chemical characteristics of uranium-238 ({sup 238}U). The purpose of the National Low-Level Waste Management Program Radionuclide Report Series is to provide information to state representatives and developers of low-level radioactive waste disposal facilities about the radiological, chemical, and physical characteristics of selected radionuclides and their behavior in the waste disposal facility environment. This report also includes discussions about waste types and forms in which {sup 238}U can be found, and {sup 238}U behavior in the environment and in the human body.

Radionuclides in Chesapeake Bay sediments

NASA Technical Reports Server (NTRS)

Cressy, P. J., Jr.

1976-01-01

Natural and manmade gamma-ray emitting radionuclides were measured in Chesapeake Bay sediments taken near the Calvert Cliffs Nuclear Power Plant site. Samples represented several water depths, at six locations, for five dates encompassing a complete seasonal cycle. Radionuclide contents of dry sediments ranged as follows: Tl-208, 40 to 400 pCi/kg; Bi-214, 200 to 800 pCi/kg; K, 0.04 to 2.1 percent; Cs-137 5 to 1900 pCi/kg; Ru106, 40 to 1000 pCikg Co60, 1 to 27 pCi/kg. In general, radionuclide contents were positively correlated with each other and negatively correlated with sediment grain size.

Derivation of the Korean radwaste scaling factor

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kwang Yong Jee; Hong Joo Ahn; Se Chul Sohn

2007-07-01

The concentrations of several radionuclides in low and intermediate level radioactive waste (LILW) drums have to be determined before shipping to disposal facilities. A notice, by the Ministry of Science and Technology (MOST) of the Korean Government, related to the disposal of LILW drums came into effect at the beginning of 2005, with regards to a radionuclide regulation inside a waste drum. MOST allows for an indirect radionuclide assay using a scaling factor to measure the inventories due to the difficulty of nondestructively measuring the essential {alpha} and {beta}-emitting nuclides inside a drum. That is, a scaling factor calculated throughmore » a correlation of the {alpha} or {beta}-emitting nuclide (DTM, Difficult-To-Measure) with a {gamma}-emitting nuclide (ETM, Easy-To-Measure) which has systematically similar properties with DTM nuclides. In this study, radioactive wastes, such as spent resin and dry active waste which were generated at different sites of a PWR and a site of a PHWR type Korean NPP, were partially sampled and analyzed for regulated radionuclides by using radiochemical methods. According to a reactor type and a waste form, the analysis results of each radionuclide were classified. Korean radwaste scaling factor was derived from database of radionuclide concentrations. (authors)« less

Copper Loading of Preformed Nanoparticles for PET-Imaging Applications.

PubMed

Lu, Hoang D; Wang, Leon Z; Wilson, Brian K; McManus, Simon A; Jumai'an, Jenny; Padakanti, Prashanth K; Alavi, Abass; Mach, Robert H; Prud'homme, Robert K

2018-01-31

Nanoparticles (NP) are promising contrast agents for positron emission tomography (PET) radionuclide imaging that can increase signal intensity by localizing clusters of PET radionuclides together. However, methods to load NPs with PET radionuclides suffer from harsh loading conditions or poor loading efficacies or result in NP surface modifications that alter targeting in vivo. We present the formation of water-dispersible, polyethylene glycol coated NPs that encapsulate phthalocyanines into NP cores at greater than 50 wt % loading, using the self-assembly technique Flash NanoPrecipitation. Particles from 70 to 160 nm are produced. Phthalocyanine NPs rapidly and spontaneously chelate metals under mild conditions and can act as sinks for PET radionuclides such as 64-Cu to produce PET-active NPs. NPs chelate copper(II) with characteristic rates of 1845 M -1 h -1 at pH 6 and 37 °C, which produced >90% radionuclide chelation within 1 h. NP physical properties, such as core composition, core fluidity, and size, can be tuned to modulate chelation kinetics. These NPs retain 64 Cu even in the presence of the strong chelator ethylene diamine tetraacetic acid. The development of these constructs for rapid and facile radionuclide labeling expands the applications of NP-based PET imaging.

Naturally Occurring Radionuclides of Ash Produced by Coal Combustion. The Case of the Kardia Mine in Northern Greece

NASA Astrophysics Data System (ADS)

Fotakis, M.; Tsikritzis, L.; Tzimkas, N.; Kolovos, N.; Tsikritzi, R.

2008-08-01

West Macedonia Lignite Center (WMLC), located in Northwest Greece, releases into the atmosphere about 21,400 tons/year of fly ash through the stacks of four coal fired plants. The lignite ash contains naturally occurring radionuclides, which are deposited on the WMLC basin. This work investigates the natural radioactivity of twenty six ash samples, laboratory produced from combustion of lignite, which was sampled perpendicularly to the benches of the Kardia mine. The concentrations of radionuclides 40K, 235U, 238U, 226Ra, 228Ra and 232Th, were measured spectroscopically and found round one order of magnitude as high as those of lignite. Subsequently the Radionuclide Partitioning Coefficients of radionuclides were calculated and it was found that they are higher for 232Th, 228Ra and 40K, because the latter have closer affinity with the inorganic matrix of lignite. During combustion up to one third of the naturally occurring radioisotopes escape from the solid phase into the flue gases. With comparison to relative global data, the investigated ash has been found to have relatively high radioactivity, but the emissions of the WMLC radionuclides contribute only 0.03% to the mean annual absorbed dose.

Radiation Doses from the Norwegian Diet.

PubMed

Komperød, Mari; Skuterud, Lavrans

2018-06-13

Ingestion doses between and within countries are expected to vary significantly due to differences in dietary habits and geographical variations in radionuclide concentrations. This paper presents the most comprehensive assessment to date of the effective radiation dose from the Norwegian diet, from natural as well as anthropogenic radionuclides. Ingestion doses to the Norwegian public are calculated using national dietary statistics and the most relevant radionuclide concentration data for the various food products. The age-weighted average effective dose received by the Norwegian population from the diet is estimated at 0.41 mSv y from naturally occurring radionuclides and 0.010 mSv y from anthropogenic radionuclides. This is approximately 50% higher than the estimated world average. Fish and shellfish is the food group that provides the largest dose contribution from the average Norwegian diet. Although the average dose from anthropogenic radionuclides today is low, the exposure may still be significant for certain critical groups-especially persons who consume large amounts of reindeer meat from the regions that received significant radioactive fallout after the Chernobyl accident. Furthermore, persons with high Rn concentrations in their drinking water are among those receiving the highest ingestion doses in Norway.

Bioremediation: a genuine technology to remediate radionuclides from the environment.

PubMed

Prakash, Dhan; Gabani, Prashant; Chandel, Anuj K; Ronen, Zeev; Singh, Om V

2013-07-01

Radionuclides in the environment are a major human and environmental health concern. Like the Chernobyl disaster of 1986, the Fukushima Daiichi nuclear disaster in 2011 is once again causing damage to the environment: a large quantity of radioactive waste is being generated and dumped into the environment, and if the general population is exposed to it, may cause serious life-threatening disorders. Bioremediation has been viewed as the ecologically responsible alternative to environmentally destructive physical remediation. Microorganisms carry endogenous genetic, biochemical and physiological properties that make them ideal agents for pollutant remediation in soil and groundwater. Attempts have been made to develop native or genetically engineered (GE) microbes for the remediation of environmental contaminants including radionuclides. Microorganism-mediated bioremediation can affect the solubility, bioavailability and mobility of radionuclides. Therefore, we aim to unveil the microbial-mediated mechanisms for biotransformation of radionuclides under various environmental conditions as developing strategies for waste management of radionuclides. A discussion follows of '-omics'-integrated genomics and proteomics technologies, which can be used to trace the genes and proteins of interest in a given microorganism towards a cell-free bioremediation strategy. © 2013 The Authors. Microbial Biotechnology published by John Wiley & Sons Ltd and Society for Applied Microbiology.

RADIONUCLIDE INVENTORY AND DISTRIBUTION: FOURMILE BRANCH, PEN BRANCH, AND STEEL CREEK IOUS

DOE Office of Scientific and Technical Information (OSTI.GOV)

Hiergesell, R.; Phifer, M.

2014-04-29

As a condition to the Department of Energy (DOE) Low Level Waste Disposal Federal Facility Review Group (LFRG) review team approving the Savannah River Site (SRS) Composite Analysis (CA), SRS agreed to follow up on a secondary issue, which consisted of the consolidation of several observations that the team concluded, when evaluated collectively, could potentially impact the integration of the CA results. This report addresses secondary issue observations 4 and 21, which identify the need to improve the CA sensitivity and uncertainty analysis specifically by improving the CA inventory and the estimate of its uncertainty. The purpose of the workmore » described herein was to be responsive to these secondary issue observations by re-examining the radionuclide inventories of the Integrator Operable Units (IOUs), as documented in ERD 2001 and Hiergesell, et. al. 2008. The LFRG concern has been partially addressed already for the Lower Three Runs (LTR) IOU (Hiergesell and Phifer, 2012). The work described in this investigation is a continuation of the effort to address the LFRG concerns by re-examining the radionuclide inventories associated with Fourmile Branch (FMB) IOU, Pen Branch (PB) IOU and Steel Creek (SC) IOU. The overall approach to computing radionuclide inventories for each of the IOUs involved the following components: • Defining contaminated reaches of sediments along the IOU waterways • Identifying separate segments within each IOU waterway to evaluate individually • Computing the volume and mass of contaminated soil associated with each segment, or “compartment” • Obtaining the available and appropriate Sediment and Sediment/Soil analytical results associated with each IOU • Standardizing all radionuclide activity by decay-correcting all sample analytical results from sample date to the current point in time, • Computing representative concentrations for all radionuclides associated with each compartment in each of the IOUs • Computing the radionuclide inventory of each DOE-added radionuclide for the compartments of each IOU by applying the representative, central value concentration to the mass of contaminated soil • Totaling the inventory for all compartments associated with each of the IOUs Using this approach the 2013 radionuclide inventories for each sub-compartment associated with each of the three IOUs were computed, by radionuclide. The inventories from all IOU compartments were then rolled-up into a total inventory for each IOU. To put the computed estimate of radionuclide activities within FMB, PB, and SC IOUs into context, attention was drawn to Cs-137, which was the radionuclide with the largest contributor to the calculated dose to a member of the public at the perimeter of SRS within the 2010 SRS CA (SRNL 2010). The total Cs-137 activity in each of the IOUs was calculated to be 9.13, 1.5, and 17.4 Ci for FMB, PB, and SC IOUs, respectively. Another objective of this investigation was to address the degree of uncertainty associated with the estimated residual radionuclide activity that is calculated for the FMB, PB, and SC IOUs. Two primary contributing factors to overall uncertainty of inventory estimates were identified and evaluated. The first related to the computation of the mass of contaminated material in a particular IOU compartment and the second to the uncertainty associated with analytical counting errors. The error ranges for the mass of contaminated material in each IOU compartment were all calculated to be approximately +/- 9.6%, or a nominal +/-10%. This nominal value was added to the uncertainty associated with the analytical counting errors that were associated with each radionuclide, individually. This total uncertainty was then used to calculate a maximum and minimum estimated radionuclide inventories for each IOU.« less

Electrochemical separation is an attractive strategy for development of radionuclide generators for medical applications.

PubMed

Chakravarty, Rubel; Dash, Ashutosh; Pillai, M R A

2012-07-01

Electrochemical separation techniques are not widely used in radionuclide generator technology and only a few studies have been reported [1-4]. Nevertheless, this strategy is useful when other parent-daughter separation techniques are not effective or not possible. Such situations are frequent when low specific activity (LSA) parent radionuclides are used for instance with adsorption chromatographic separations, which can result in lower concentration of the daughter radionuclide in the eluent. In addition, radiation instability of the column matrix in many cases can affect the performance of the generator when long lived parent radionuclides are used. Intricate knowledge of the chemistry involved in the electrochemical separation is crucial to develop a reproducible technology that ensures that the pure daughter radionuclide can be obtained in a reasonable time of operation. Crucial parameters to be critically optimized include the applied potential, choice of electrolyte, selection of electrodes, temperature of electrolyte bath and the time of electrolysis in order to ensure that the daughter radionuclide can be reproducibly recovered in high yields and high purity. The successful electrochemical generator technologies which have been developed and are discussed in this paper include the (90)Sr/(90)Y, (188)W/(188)Re and (99)Mo/(99m)Tc generators. Electrochemical separation not only acts as a separation technique but also is an effective concentration methodology which yields high radioactive concentrations of the daughter products. The lower consumption of reagents and minimal generation of radioactive wastes using such electrochemical techniques are compatible with 'green chemistry' principles.

Particle size distribution of radioactive aerosols after the Fukushima and the Chernobyl accidents.

PubMed

Malá, Helena; Rulík, Petr; Bečková, Vera; Mihalík, Ján; Slezáková, Miriam

2013-12-01

Following the Fukushima accident, a series of aerosol samples were taken between 24th March and 13th April 2011 by cascade impactors in the Czech Republic to obtain the size distribution of (131)I, (134)Cs, (137)Cs, and (7)Be aerosols. All distributions could be considered monomodal. The arithmetic means of the activity median aerodynamic diameters (AMADs) for artificial radionuclides and for (7)Be were 0.43 and 0.41 μm with GDSs 3.6 and 3.0, respectively. The time course of the AMADs of (134)Cs, (137)Cs and (7)Be in the sampled period showed a slight decrease at a significance level of 0.05, whereas the AMAD pertaining to (131)I increased at a significance level of 0.1. Results obtained after the Fukushima accident were compared with results obtained after the Chernobyl accident. The radionuclides released during the Chernobyl accident for which we determined the AMAD fell into two categories: refractory radionuclides ((140)Ba, (140)La (141)Ce, (144)Ce, (95)Zr and (95)Nb) and volatile radionuclides ((134)Cs, (137)Cs, (103)Ru, (106)Ru, (131)I, and (132)Te). The AMAD of the refractory radionuclides was approximately 3 times higher than the AMAD of the volatile radionuclides; nevertheless, the size distributions for volatile radionuclides having a mean AMAD value of 0.51 μm were very close to the distributions after the Fukushima accident. Copyright © 2013 Elsevier Ltd. All rights reserved.

Literature Review and Assessment of Plant and Animal Transfer Factors Used in Performance Assessment Modeling

DOE Office of Scientific and Technical Information (OSTI.GOV)

Robertson, David E.; Cataldo, Dominic A.; Napier, Bruce A.

2003-07-20

A literature review and assessment was conducted by Pacific Northwest National Laboratory (PNNL) to update information on plant and animal radionuclide transfer factors used in performance-assessment modeling. A group of 15 radionuclides was included in this review and assessment. The review is composed of four main sections, not including the Introduction. Section 2.0 provides a review of the critically important issue of physicochemical speciation and geochemistry of the radionuclides in natural soil-water systems as it relates to the bioavailability of the radionuclides. Section 3.0 provides an updated review of the parameters of importance in the uptake of radionuclides by plants,more » including root uptake via the soil-groundwater system and foliar uptake due to overhead irrigation. Section 3.0 also provides a compilation of concentration ratios (CRs) for soil-to-plant uptake for the 15 selected radionuclides. Section 4.0 provides an updated review on radionuclide uptake data for animal products related to absorption, homeostatic control, approach to equilibration, chemical and physical form, diet, and age. Compiled transfer coefficients are provided for cow’s milk, sheep’s milk, goat’s milk, beef, goat meat, pork, poultry, and eggs. Section 5.0 discusses the use of transfer coefficients in soil, plant, and animal modeling using regulatory models for evaluating radioactive waste disposal or decommissioned sites. Each section makes specific suggestions for future research in its area.« less

Transfer of radionuclides to plants of natural ecosystems at the Semipalatinsk Test Site.

PubMed

Larionova, N V; Lukashenko, S N; Kabdyrakova, A M; Kunduzbayeva, A Ye; Panitskiy, A V; Ivanova, A R

2018-06-01

A systematic study devoted to 137 Cs, 90 Sr, 241 Am, 239+240 Pu radionuclides in vegetation cover from several spots of the Semipalatinsk test site (STS) is summarised in this paper, highlighting the main findings obtained. The analysed spots are characterized by various types of radioactive contamination. Transfer factors (Tf) required for the quantitative description of the radionuclides transition from the soil to aboveground plant parts were determined, being found that, on average, the minimum Tf for all the radionuclides concerned were determined on the "Experimental Field" ground, followed by the determined ones in the "plumes" of radioactive fallout and in the conditionally "background" territories analysed. The highest transfer factors were characteristic of zones of radioactive streamflows and places of warfare radioactive agent (WRA) tests. On the other hand, ordering the radionuclide transferring factors in descending order, the following sequence was obtained: 90 Sr Tf > Cs Tf >  239+240 Pu Tf >  241 Am Tf, with the 90 Sr Tf, on the average, exceeding the 137 Cs Tf by 8 times and exceeding the 239+240 Pu Tf by up 16 times. 239+240 Pu Tf values were up to 3 times higher than the 241 Am Tf. The exception to the indicated radionuclide Tf descending order corresponded to places of WRA tests where Tf of radionuclides of interest by plants follows the sequence 90 Sr >  239+240 Pu >  137 Cs. Copyright © 2017 Elsevier Ltd. All rights reserved.

Respiratory tract deposition efficiencies: evaluation of effects from smoke released in the Cerro Grande forest fire.

PubMed

Schöllnberger, H; Aden, J; Scott, B R

2002-01-01

Forest-fire smoke inhaled by humans can cause various health effects. This smoke contains toxic chemicals and naturally occurring radionuclides. In northern New Mexico, a large wildfire occurred in May 2000. Known as the Cerro Grande Fire, it devastated the town of Los Alamos and damaged Los Alamos National Laboratory (LANL). Residents were concerned about the possible dissemination of radionuclides from LANL via smoke from the fire. To evaluate potential health effects of inhaling radionuclides contained in the smoke from the Cerro Grande Fire, it was first necessary to evaluate how much smoke would deposit in the human respiratory tract. The purpose of this study was to evaluate respiratory-tract deposition efficiencies of airborne forest-fire smoke for persons of different ages exposed while inside their homes. Potential non-radiological health effects of a forest fire are reviewed. The deposition efficiencies presented can be used to evaluate in-home smoke deposition in the respiratory tract and expected radionuclide intake related to forest fires. The impact of smoke exposure on firemen fighting a forest fire is quantitatively discussed and compared. They primarily inhaled forest-fire smoke while outdoors where the smoke concentration was much higher than inside. Radionuclides released at the LANL site via the Cerro Grande Fire were restricted to naturally occurring radionuclides from burning trees and vegetation. Radiation doses from inhaled airborne radionuclides to individuals inside and outside the Los Alamos area were likely very small.

DETERMINATION OF REPORTABLE RADIONUCLIDES FOR DWPF SLUDGE BATCH 7B (MACROBATCH 9)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, C. L.; Diprete, D. P.

The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production throughmore » the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu- 242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to radionuclide inventory. This work was initiated through Technical Task Request (TTR) HLW-DWPF-TTR-2011-0004; Rev. 0 entitled Sludge Batch 7b Qualification Studies. Specifically, this report details results from performing Subtask II, Item 2 of the TTR and, in part, meets Deliverable 6 of the TTR. The work was performed following the Task Technical and Quality Assurance Plan (TTQAP), SRNL-RP-2011-00247, Rev. 0 and Analytical Study Plan (ASP), SRNL-RP-2011-00248, Rev. 0. In order to determine the reportable radionuclides for SB7b (MB9), a list of radioisotopes that may meet the criteria as specified by the Department of Energy’s (DOE) WAPS was developed. All radioactive U- 235 fission products and all radioactive activation products that could be in the SRS HLW were considered. In addition, all U and Pu isotopes identified in WAPS 1.6 were included in the list. This list was then evaluated and some isotopes were excluded from the projection calculations. Based on measurements and analytical detection limits, 27 radionuclides have been identified as reportable for DWPF SB7b as specified by WAPS 1.2. The WCP and WQR require that all of the radionuclides present in the Design Basis glass be considered as the initial set of reportable radionuclides. For SB7b, all of the radionuclides in the Design Basis glass are reportable except for three radionuclides: Pd-107, Cs-135, and Th-230. At no time during the 1100- year period between 2015 and 3115 did any of these three radionuclides contribute to more than 0.01% of the radioactivity on a Curie basis. Two additional uranium isotopes (U-235 and -236) must be added to the list of reportable radionuclides in order to meet WAPS 1.6. All of the Pu isotopes (Pu-238, -239, -240, -241, and -242) and other U isotopes (U-233, -234, and -238) identified in WAPS 1.6 were already determined to be reportable according to WAPS 1.2 This brings the total number of reportable radionuclides for SB7b to 29. The radionuclide measurements made for SB7b are similar to those performed in the previous SB7a MB8 work. Some method development/refinement occurred during the conduct of these measurements, leading to lower detection limits and more accurate measurement of some isotopes than was previously possible. Improvement in the analytical measurements will likely continue, and this in turn should lead to improved detection limit values for some radionuclides and actual measurements for still others.« less

Determination Of Reportable Radionuclides For DWPF Sludge Batch 7B (Macrobatch 9)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Crawford, C. L.; DiPrete, D. P.

The Waste Acceptance Product Specifications (WAPS) 1.2 require that “The Producer shall report the inventory of radionuclides (in Curies) that have half-lives longer than 10 years and that are, or will be, present in concentrations greater than 0.05 percent of the total inventory for each waste type indexed to the years 2015 and 3115”. As part of the strategy to comply with WAPS 1.2, the Defense Waste Processing Facility (DWPF) will report for each waste type, all radionuclides (with half-lives greater than 10 years) that have concentrations greater than 0.01 percent of the total inventory from time of production throughmore » the 1100 year period from 2015 through 3115. The initial listing of radionuclides to be included is based on the design-basis glass as identified in the Waste Form Compliance Plan (WCP) and Waste Form Qualification Report (WQR). However, it is required that this list be expanded if other radionuclides with half-lives greater than 10 years are identified that may meet the greater than 0.01% criterion for Curie content. Specification 1.6 of the WAPS, International Atomic Energy Agency (IAEA) Safeguards Reporting for High Level Waste (HLW), requires that the ratio by weights of the following uranium and plutonium isotopes be reported: U-233, U-234, U-235, U-236, U-238, Pu-238, Pu-239, Pu-240, Pu-241, and Pu-242. Therefore, the complete set of reportable radionuclides must also include this set of U and Pu isotopes. The DWPF is receiving radioactive sludge slurry from HLW Tank 40. The radioactive sludge slurry in Tank 40 is a blend of the heel from Sludge Batch 7a (SB7a) and Sludge Batch 7b (SB7b) that was transferred to Tank 40 from Tank 51. The blend of sludge in Tank 40 is also referred to as Macrobatch 9 (MB9). This report develops the list of reportable radionuclides and associated activities as a function of time. The DWPF will use this list and the activities as one of the inputs for the development of the Production Records that relate to radionuclide inventory. This work was initiated through Technical Task Request (TTR) HLW-DWPF-TTR-2011-0004; Rev. 0 entitled Sludge Batch 7b Qualification Studies. Specifically, this report details results from performing Subtask II, Item 2 of the TTR and, in part, meets Deliverable 6 of the TTR. The work was performed following the Task Technical and Quality Assurance Plan (TTQAP), SRNL-RP-2011-00247, Rev. 0 and Analytical Study Plan (ASP), SRNL-RP-2011-00248, Rev. 0. In order to determine the reportable radionuclides for SB7b (MB9), a list of radioisotopes that may meet the criteria as specified by the Department of Energy’s (DOE) WAPS was developed. All radioactive U-235 fission products and all radioactive activation products that could be in the SRS HLW were considered. In addition, all U and Pu isotopes identified in WAPS 1.6 were included in the list. This list was then evaluated and some isotopes were excluded from the projection calculations. Based on measurements and analytical detection limits, 27 radionuclides have been identified as reportable for DWPF SB7b as specified by WAPS 1.2. The WCP and WQR require that all of the radionuclides present in the Design Basis glass be considered as the initial set of reportable radionuclides. For SB7b, all of the radionuclides in the Design Basis glass are reportable except for three radionuclides: Pd-107, Cs-135, and Th-230. At no time during the 1100-year period between 2015 and 3115 did any of these three radionuclides contribute to more than 0.01% of the radioactivity on a Curie basis. Two additional uranium isotopes (U-235 and -236) must be added to the list of reportable radionuclides in order to meet WAPS 1.6. All of the Pu isotopes (Pu-238, -239, -240, -241, and -242) and other U isotopes (U-233, -234, and -238) identified in WAPS 1.6 were already determined to be reportable according to WAPS 1.2 This brings the total number of reportable radionuclides for SB7b to 29. The radionuclide measurements made for SB7b are similar to those performed in the previous SB7a MB8 work. Some method development/refinement occurred during the conduct of these measurements, leading to lower detection limits and more accurate measurement of some isotopes than was previously possible. Improvement in the analytical measurements will likely continue, and this in turn should lead to improved detection limit values for some radionuclides and actual measurements for still others.« less

Method for electrochemical decontamination of radioactive metal

DOEpatents

Ekechukwu, Amy A [Augusta, GA

2008-06-10

A decontamination method for stripping radionuclides from the surface of stainless steel or aluminum material comprising the steps of contacting the metal with a moderately acidic carbonate/bicarbonate electrolyte solution containing sodium or potassium ions and thereafter electrolytically removing the radionuclides from the surface of the metal whereby radionuclides are caused to be stripped off of the material without corrosion or etching of the material surface.

Livermore Accelerator Source for Radionuclide Science (LASRS)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Anderson, Scott; Bleuel, Darren; Johnson, Micah

The Livermore Accelerator Source for Radionuclide Science (LASRS) will generate intense photon and neutron beams to address important gaps in the study of radionuclide science that directly impact Stockpile Stewardship, Nuclear Forensics, and Nuclear Material Detection. The co-location of MeV-scale neutral and photon sources with radiochemical analytics provides a unique facility to meet current and future challenges in nuclear security and nuclear science.

Accumulation of artificial radionuclides in deep sediments of the Mediterranean Sea

NASA Astrophysics Data System (ADS)

Garcia-Orellana, J.; Sanchez-Cabeza, J. A.; Masque, P.; Costa, E.; Bruach, J. M.; Morist, A.; Luna, J. A.

2003-04-01

Concentrations and inventories of artificial radionuclides (90Sr, 137Cs and 239,40Pu) were determined in deep sediment cores (3.000 m) collected in the western and eastern basins of the Mediterranean Sea in the frame of the ADIOS project. Artificial radionuclides enter the Mediterranean Sea mainly though atmospheric deposition after nuclear weapons tests and the Chernobyl accident, but also through the river discharge of effluents of nuclear facilities (e.g. Rhone and Ebro rivers). The aim of this work is to investigate the degree by which pollutants are transferred to the deep environment of the Mediterranean Sea as a basis to elucidate their effects on benthic organisms. The mean inventories of 239+240Pu, 137Cs and 90Sr in the Western basin are 2.77 ± 0.26, 68 ± 12 and < 7 Bq\\cdotm-2 respectively and 3.29 ± 0.60, 115 ± 33 and 249±154 Bq\\cdotm-2 in the Eastern basin. The activity - depth profiles of 210Pb, together with 14C dating, indicate that sediment mixing redistributes the artificial radionuclides within the first 2 cm of the sedimentary column. Artificial radionuclides inventories in the deep-sea sediments were used to calculate the fraction of the total inventory of artificial radionuclides that is accumulated in the deep sea sediments after scavenging from the water column. Indeed, a balance of the radionuclide distributions in the water column allows evaluating the importance of lateral transport of particulate matter from the continental margins on the accumulation of artificial radionuclides in the deep, open Mediterranean Sea. This is achieved in i) comparison with reported data from coastal areas at different locations in the Mediterranean Sea, and ii) balance of the distribution of the natural radionuclide 210Pb in studied areas (vertical profiles of dissolved and particulate activities, fluxes determined by using sediment trap deployed at different depths and inventories in the bottom sediments). The results, taking into account radioactive decay and exchange fluxes through the Gibraltar Strait, permit to estimate the residence times of pollutants in the water column and predict future evolution of their distributions.

Tracer Movement in a Single Fissure in Granitic Rock: Some Experimental Results and Their Interpretation

NASA Astrophysics Data System (ADS)

Neretnieks, Ivars; Eriksen, Tryggve; TäHtinen, PäIvi

1982-08-01

Radionuclide migration was studied in a natural fissure in a granite core. The fissure was oriented parallel to the axis in a cylindrical core 30 cm long and 20 cm in diameter. The traced solution was injected at one end of the core and collected at the other. Breakthrough curves were obtained for the nonsorbing tracers, tritiated water, and a large-molecular-weight lignosulphonate molecule and for the sorbing tracers, cesium and strontium. From the breakthrough curves for the nonsorbing tracers it could be concluded that channeling occurs in the single fissure. A `dispersion' model based on channeling is presented. The results from the sorbing tracers indicate that there is substantial diffusion into and sorption in the rock matrix. Sorption on the surface of the fissure also accounts for a part of the retardation effect of the sorbing species. A model which includes the mechanisms of channeling, surface sorption, matrix diffusion, and matrix sorption is presented. The experimental breakthrough curves can be fitted fairly well by this model by use of independently obtained data on diffusivities and matrix sorption.

Migration behavior of naturally occurring radionuclides at the Nopal I uranium deposit, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Prikryl, James D.; Pickett, David A.; Murphy, William M.; Pearcy, English C.

1997-04-01

Oxidation of pyrite at the Nopal I uranium deposit, Peña Blanca district, Chihuahua, Mexico has resulted in the formation of Fe-oxides/hydroxides. Anomalous U concentrations (i.e. several hundred to several thousand ppm) measured in goethite, hematite, and amorphous Fe-oxyhydroxides in a major fracture that crosscuts the deposit and the absence of U minerals in the fracture suggest that U was retained during secondary mineral growth or sorbed on mineral surfaces. Mobilization and transport of U away from the deposit is suggested by decreasing U concentrations in fracture-infilling materials and in goethite and hematite with distance from the deposit. Greater than unity {234U}/{238U} activity ratios measured in fracture-infilling materials indicate relatively recent ( < 1 Ma) U uptake from fluids that carried excess 234U. Systematic decreases in {234U}/{238U} activity ratios of fracture materials with distance from the deposit suggest a multistage mobilization process, such as remobilization of U from 234U-enriched infill minerals or differential or diminished transport of U-bearing solutions containing excess 234U.

Experimental and Numerical Investigations on Colloid-facilitated Plutonium Reactive Transport in Fractured Tuffaceous Rocks

NASA Astrophysics Data System (ADS)

Dai, Z.; Wolfsberg, A. V.; Zhu, L.; Reimus, P. W.

2017-12-01

Colloids have the potential to enhance mobility of strongly sorbing radionuclide contaminants in fractured rocks at underground nuclear test sites. This study presents an experimental and numerical investigation of colloid-facilitated plutonium reactive transport in fractured porous media for identifying plutonium sorption/filtration processes. The transport parameters for dispersion, diffusion, sorption, and filtration are estimated with inverse modeling for minimizing the least squares objective function of multicomponent concentration data from multiple transport experiments with the Shuffled Complex Evolution Metropolis (SCEM). Capitalizing on an unplanned experimental artifact that led to colloid formation and migration, we adopt a stepwise strategy to first interpret the data from each experiment separately and then to incorporate multiple experiments simultaneously to identify a suite of plutonium-colloid transport processes. Nonequilibrium or kinetic attachment and detachment of plutonium-colloid in fractures was clearly demonstrated and captured in the inverted modeling parameters along with estimates of the source plutonium fraction that formed plutonium-colloids. The results from this study provide valuable insights for understanding the transport mechanisms and environmental impacts of plutonium in fractured formations and groundwater aquifers.

Phase I Transport Model of Corrective Action Units 101 and 102: Central and Western Pahute Mesa, Nevada Test Site, Nye County, Nevada with Errata Sheet 1, 2, 3, Revision 1

DOE Office of Scientific and Technical Information (OSTI.GOV)

Greg Ruskauff

2009-02-01

As prescribed in the Pahute Mesa Corrective Action Investigation Plan (CAIP) (DOE/NV, 1999) and Appendix VI of the Federal Facility Agreement and Consent Order (FFACO) (1996, as amended February 2008), the ultimate goal of transport analysis is to develop stochastic predictions of a contaminant boundary at a specified level of uncertainty. However, because of the significant uncertainty of the model results, the primary goal of this report was modified through mutual agreement between the DOE and the State of Nevada to assess the primary model components that contribute to this uncertainty and to postpone defining the contaminant boundary until additionalmore » model refinement is completed. Therefore, the role of this analysis has been to understand the behavior of radionuclide migration in the Pahute Mesa (PM) Corrective Action Unit (CAU) model and to define, both qualitatively and quantitatively, the sensitivity of such behavior to (flow) model conceptualization and (flow and transport) parameterization.« less

Fracture and matrix hydrologic characteristics of tuffaceous materials from Yucca Mountain, Nye County, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Peters, R.R.; Klavetter, E.A.; Hall, I.J.

1984-12-01

The geological formations in the unsaturated zone at Yucca Mountain, on and adjacent to the Nevada Test Site (NTS), are currently being studied for consideration as the host for a radioactive-waste repository; the US Department of Energy is carrying out these studies through the Nevada Nuclear Waste Storage Investigations project. The formations are composed of tuffaceous (tuff) materials that must be evaluated to estimate the rate at which radionuclides would migrate to the accessible environment. According to the available evidence, the flux of water in the unsaturated zone beneath the Yucca Mountain site is low; quantifying such low flow ratesmore » through direct measurements is difficult. To help provide data that can be used to assess unsaturated flow, Pacific Northwest Laboratory (PNL), under contract to Sandia National Laboratories (SNL), performed hydrologic tests on tuffaceous samples from 48 different locations in Yucca Mountain. This report contains the entire set of psychrometer measurements of desaturation curves for tuffs from Yucca Mountain as well as a substantial number of saturated conductivity measurements. 19 references, 132 figures, 23 tables.« less

Long-term predictions using natural analogues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Ewing, R.C.

1995-09-01

One of the unique and scientifically most challenging aspects of nuclear waste isolation is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3}-10{sup 5} years) required by regulatory agencies for performance assessment. The direct validation of these extrapolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the lay public that there is a demonstrable and reasonable basis for accepting the long-term extrapolations. Natural systems (e.g., {open_quotes}natural analogues{close_quotes}) provide perhaps the only means of partial {open_quotes}validation,{close_quotes} as well as data that may be used directlymore » in the models that are used in the extrapolation. Natural systems provide data on very large spatial (nm to km) and temporal (10{sup 3}-10{sup 8} years) scales and in highly complex terranes in which unknown synergisms may affect radionuclide migration. This paper reviews the application (and most importantly, the limitations) of data from natural analogue systems to the {open_quotes}validation{close_quotes} of performance assessments.« less

MCNPX CALCULATIONS OF SPECIFIC ABSORBED FRACTIONS IN SOME ORGANS OF THE HUMAN BODY DUE TO APPLICATION OF 133Xe, 99mTc and 81mKr RADIONUCLIDES.

PubMed

Jovanovic, Z; Krstic, D; Nikezic, D; Ros, J M Gomez; Ferrari, P

2018-03-01

Monte Carlo simulations were performed to evaluate treatment doses with wide spread used radionuclides 133Xe, 99mTc and 81mKr. These different radionuclides are used in perfusion or ventilation examinations in nuclear medicine and as indicators for cardiovascular and pulmonary diseases. The objective of this work was to estimate the specific absorbed fractions in surrounding organs and tissues, when these radionuclides are incorporated in the lungs. For this purpose a voxel thorax model has been developed and compared with the ORNL phantom. All calculations and simulations were performed by means of the MCNP5/X code.

New irradiation facilities for development of production methods of medical radionuclides at cyclotrons at Forschungszentrum Jülich

NASA Astrophysics Data System (ADS)

Spellerberg, S.; Scholten, B.; Spahn, I.; Felden, O.; Gebel, R.; Qaim, S. M.; Bai, M.; Neumaier, B.

2017-05-01

An essential basis for research and development work on radiopharmaceuticals is the efficient production of radionuclides of high quality. In this process research-oriented studies aiming for elucidation of biochemical processes require novel products. The radionuclide development at INM-5 entails basic research, e.g. the determination of nuclear reaction data, as well as technical aspects of practical production, such as high-current targetry, chemical separation, formulation and quality control. In this work developments, adaptation and optimization of irradiation facilities at the BC 1710, JULIC as Injector of COSY and COSY itself are summarized, which shall allow the extension of radionuclide production possibilities, aiming at innovations in medical applications.

Verifying the operational set-up of a radionuclide air-monitoring station.

PubMed

Werzi, R; Padoani, F

2007-05-01

A worldwide radionuclide network of 80 stations, part of the International Monitoring System, was designed to monitor compliance with the Comprehensive Nuclear-Test-Ban Treaty. After installation, the stations are certified to comply with the minimum requirements laid down by the Preparatory Commission of the Comprehensive Nuclear-Test-Ban Treaty Organization. Among the several certification tests carried out at each station, the verification of the radionuclide activity concentrations is a crucial one and is based on an independent testing of the airflow rate measurement system and of the gamma detector system, as well as on the assessment of the samples collected during parallel sampling and measured at radionuclide laboratories.

Hanford Soil Inventory Model (SIM-v2) Calculated Radionuclide Inventory of Direct Liquid Discharges to Soil in the Hanford Site's 200 Areas.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Nichols, William E.; Zaher, U.; Agnew, S.

The Hanford soil inventory model (SIM) provides the basic radionuclide and chemical soil inventories from historical liquid discharges to about 400 sites at the Hanford Site. Although liquid discharge inventory for chemicals is part of the SIM implementation, only radionuclide inventory is discussed here since the focus of this ECF is on providing radionuclides inputs for the composite analysis (CA) per DOE Order 435.1, Radioactive Waste Management, requirements. Furthermore, discharged inventories are only estimated for the soluble portions of the liquid discharges to waste sites/waste management areas located on the 200 Area of the Hanford Site (Central Plateau).

Identification of penetration path and deposition distribution of radionuclides in houses by experiments and numerical model

NASA Astrophysics Data System (ADS)

Hirouchi, Jun; Takahara, Shogo; Iijima, Masashi; Watanabe, Masatoshi; Munakata, Masahiro

2017-11-01

In order to lift of an evacuation order in evacuation areas and return residents to their homes, human dose assessments are required. However, it is difficult to exactly assess indoor external dose rate because the indoor distribution and infiltration pathways of radionuclides are unclear. This paper describes indoor and outdoor dose rates measured in eight houses in the difficult-to-return area in Fukushima Prefecture and identifies the distribution and main infiltration pathway of radionuclides in houses. In addition, it describes dose rates calculated with a Monte Carlo photon transport code to aid a thorough understanding of the measurements. The measurements and calculations indicate that radionuclides mainly infiltrate through visible openings such as vents, windows, and doors, and then deposit near these visible openings; however, they hardly infiltrate through sockets and air conditioning outlets. The measurements on rough surfaces such as bookshelves implies that radionuclides discharged from the Fukushima-Daiichi nuclear power plant did not deposit locally on rough surfaces.

MIRD Pamphlet No. 23: Quantitative SPECT for Patient-Specific 3-Dimensional Dosimetry in Internal Radionuclide Therapy

PubMed Central

Dewaraja, Yuni K.; Frey, Eric C.; Sgouros, George; Brill, A. Bertrand; Roberson, Peter; Zanzonico, Pat B.; Ljungberg, Michael

2012-01-01

In internal radionuclide therapy, a growing interest in voxel-level estimates of tissue-absorbed dose has been driven by the desire to report radiobiologic quantities that account for the biologic consequences of both spatial and temporal nonuniformities in these dose estimates. This report presents an overview of 3-dimensional SPECT methods and requirements for internal dosimetry at both regional and voxel levels. Combined SPECT/CT image-based methods are emphasized, because the CT-derived anatomic information allows one to address multiple technical factors that affect SPECT quantification while facilitating the patient-specific voxel-level dosimetry calculation itself. SPECT imaging and reconstruction techniques for quantification in radionuclide therapy are not necessarily the same as those designed to optimize diagnostic imaging quality. The current overview is intended as an introduction to an upcoming series of MIRD pamphlets with detailed radionuclide-specific recommendations intended to provide best-practice SPECT quantification–based guidance for radionuclide dosimetry. PMID:22743252

Spatial distribution and risk assessment of radionuclides in soils around a coal-fired power plant: A case study from the city of Baoji, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai Lijun; Wei Haiyan; Wang Lingqing

2007-06-15

Coal burning may enhance human exposure to the natural radionuclides that occur around coal-fired power plants (CFPP). In this study, the spatial distribution and hazard assessment of radionuclides found in soils around a CFPP were investigated using statistics, geostatistics, and geographic information system (GIS) techniques. The concentrations of {sup 226}Ra, {sup 232}Th, and {sup 40}K in soils range from 12.54 to 40.18, 38.02 to 72.55, and 498.02 to 1126.98 Bq kg{sup -1}, respectively. Ordinary kriging was carried out to map the spatial patterns of radionuclides, and disjunctive kriging was used to quantify the probability of radium equivalent activity (Ra{sub eq})more » higher than the threshold. The maps show that the spatial variability of the natural radionuclide concentrations in soils was apparent. The results of this study could provide valuable information for risk assessment of environmental pollution and decision support.« less

Spatial distribution and risk assessment of radionuclides in soils around a coal-fired power plant: A case study from the city of Baoji, China

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dai, L.J.; Wei, H.Y.; Wang, L.Q.

2007-06-15

Coal burning may enhance human exposure to the natural radionuclides that occur around coal-fired power plants (CFPP). In this study, the spatial distribution and hazard assessment of radionuclides found in soils around a CFPP were investigated using statistics, geostatistics, and geographic information system (GIS) techniques. The concentrations of Ra-226, Th-232, and K-40 in soils range from 12.54 to 40.18, 38.02 to 72.55, and 498.02 to 1126.98 Bq kg{sup -1}, respectively. Ordinary kriging was carried out to map the spatial patterns of radionuclides, and disjunctive kriging was used to quantify the probability of radium equivalent activity (Ra{sub eq}) higher than themore » threshold. The maps show that the spatial variability of the natural radionuclide concentrations in soils was apparent. The results of this study could provide valuable information for risk assessment of environmental pollution and decision support.« less

Spent fuel radionuclide source-term model for assessing spent fuel performance in geological disposal. Part I: Assessment of the instant release fraction

NASA Astrophysics Data System (ADS)

Johnson, Lawrence; Ferry, Cécile; Poinssot, Christophe; Lovera, Patrick

2005-11-01

A source-term model for the short-term release of radionuclides from spent nuclear fuel (SNF) has been developed. It provides quantitative estimates of the fraction of various radionuclides that are expected to be released rapidly (the instant release fraction, or IRF) when water contacts the UO 2 or MOX fuel after container breaching in a geological repository. The estimates are based on correlation of leaching data for radionuclides with fuel burnup and fission gas release. Extrapolation of the data to higher fuel burnup values is based on examination of data on fuel restructuring, such as rim development, and on fission gas release data, which permits bounding IRF values to be estimated assuming that radionuclide releases will be less than fission gas release. The consideration of long-term solid-state changes influencing the IRF prior to canister breaching is addressed by evaluating alpha self-irradiation enhanced diffusion, which may gradually increase the accumulation of fission products at grain boundaries.

New best estimates for radionuclide solid-liquid distribution coefficients in soils. Part 2: naturally occurring radionuclides.

PubMed

Vandenhove, H; Gil-García, C; Rigol, A; Vidal, M

2009-09-01

Predicting the transfer of radionuclides in the environment for normal release, accidental, disposal or remediation scenarios in order to assess exposure requires the availability of an important number of generic parameter values. One of the key parameters in environmental assessment is the solid liquid distribution coefficient, K(d), which is used to predict radionuclide-soil interaction and subsequent radionuclide transport in the soil column. This article presents a review of K(d) values for uranium, radium, lead, polonium and thorium based on an extensive literature survey, including recent publications. The K(d) estimates were presented per soil groups defined by their texture and organic matter content (Sand, Loam, Clay and Organic), although the texture class seemed not to significantly affect K(d). Where relevant, other K(d) classification systems are proposed and correlations with soil parameters are highlighted. The K(d) values obtained in this compilation are compared with earlier review data.

A simple and rapid technique for radiochemical separation of iodine radionuclides from irradiated tellurium using an activated charcoal column.

PubMed

Chattopadhyay, Sankha; Saha Das, Sujata

2009-10-01

A simple and inexpensive method for the separation of medically useful no-carrier-added (nca) iodine radionuclides from bulk amounts of irradiated tellurium dioxide (TeO(2)) target was developed. The beta(-) emitting (131)I radionuclide, produced by the decay of (131)Te through the (nat)Te(n, gamma)(131)Te nuclear reaction, was used for standardization of the radiochemical separation procedure. The radiochemical separation was performed by precipitation followed by column (activated charcoal) chromatography. Quantitative post-irradiation recovery of the TeO(2) target material (98-99%), in a form suitable for reuse in future irradiations, was achieved. The overall radiochemical yield for the complete separation of (131)I was 75-85% (n=8). The separated nca (131)I was of high, approximately 99%, radionuclidic and radiochemical purities and did not contain detectable amounts of the target material. This method can be adopted for the radiochemical separation of other different iodine radionuclides produced from tellurium matrices through cyclotron as well as reactor irradiation.

Use of {sup 59}Ni, {sup 99}Tc, and {sup 236}U to monitor the release of radionuclides from objects containing spent nuclear fuel dumped in the Kara Sea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Mount, M.E.; Layton, D.W.; Lynn, N.M.

1998-04-01

Between 1965 and 1981, five objects - six naval reactor pressure vessels (RPVs) from four former Soviet Union submarines and a special containers from the icebreaker Lenin, each of which contained damaged spent nuclear fuel (SNF) - were dumped in a variety of containments, using a number of sealing methods, at four sites in the Kara Sea. All objects were dumped at sites that varied in depth from 12 to 300 m. This paper examines the use of the long-lived radionuclides {sup 59}Ni, {sup 99}Tc, and {sup 236}U encased within these objects to monitor the breakdown of the containments duemore » to corrosion. Included are discussions of the radionuclide inventory and their release rate model, the estimated radionuclide mass in a typical seawater sample, and the potential for radionuclide measurement via Accelerator Mass Spectrometry (AMS).« less

THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience

PubMed Central

Baum, Richard P.; Kulkarni, Harshad R.

2012-01-01

The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction. PMID:22768024

Simple model for the reconstruction of radionuclide concentrations and radiation exposures along the Techa River

NASA Technical Reports Server (NTRS)

Vorobiova, M. I.; Degteva, M. O.; Neta, M. O. (Principal Investigator)

1999-01-01

The Techa River (Southern Urals, Russia) was contaminated in 1949-1956 by liquid radioactive wastes from the Mayak complex, the first Russian facility for the production of plutonium. The measurements of environmental contamination were started in 1951. A simple model describing radionuclide transport along the free-flowing river and the accumulation of radionuclides by bottom sediments is presented. This model successfully correlates the rates of radionuclide releases as reconstructed by the Mayak experts, hydrological data, and available environmental monitoring data for the early period of contamination (1949-1951). The model was developed to reconstruct doses for people who lived in the riverside communities during the period of the releases and who were chronically exposed to external and internal irradiation. The model fills the data gaps and permits reconstruction of external gamma-exposure rates in air on the river bank and radionuclide concentrations in river water used for drinking and other household needs in 1949-1951.

Real-time radionuclide identification in γ-emitter mixtures based on spiking neural network.

PubMed

Bobin, C; Bichler, O; Lourenço, V; Thiam, C; Thévenin, M

2016-03-01

Portal radiation monitors dedicated to the prevention of illegal traffic of nuclear materials at international borders need to deliver as fast as possible a radionuclide identification of a potential radiological threat. Spectrometry techniques applied to identify the radionuclides contributing to γ-emitter mixtures are usually performed using off-line spectrum analysis. As an alternative to these usual methods, a real-time processing based on an artificial neural network and Bayes' rule is proposed for fast radionuclide identification. The validation of this real-time approach was carried out using γ-emitter spectra ((241)Am, (133)Ba, (207)Bi, (60)Co, (137)Cs) obtained with a high-efficiency well-type NaI(Tl). The first tests showed that the proposed algorithm enables a fast identification of each γ-emitting radionuclide using the information given by the whole spectrum. Based on an iterative process, the on-line analysis only needs low-statistics spectra without energy calibration to identify the nature of a radiological threat. Copyright © 2015 Elsevier Ltd. All rights reserved.

THERANOSTICS: From Molecular Imaging Using Ga-68 Labeled Tracers and PET/CT to Personalized Radionuclide Therapy - The Bad Berka Experience.

PubMed

Baum, Richard P; Kulkarni, Harshad R

2012-01-01

The acronym THERANOSTICS epitomizes the inseparability of diagnosis and therapy, the pillars of medicine and takes into account personalized management of disease for a specific patient. Molecular phenotypes of neoplasms can be determined by molecular imaging with specific probes using positron emission tomography (PET), single photon emission computed tomography (SPECT), magnetic resonance imaging (MRI), or optical methods, so that the treatment is specifically targeted against the tumor and its environment. To meet these demands, we need to define the targets, ligands, coupling and labeling chemistry, the most appropriate radionuclides, biodistribution modifiers, and finally select the right patients for the personalized treatment. THERANOSTICS of neuroendocrine tumors (NETs) using Ga-68 labeled tracers for diagnostics with positron emission tomography/ computed tomography (PET/CT), and using Lu-177 or other metallic radionuclides for radionuclide therapy by applying the same peptide proves that personalized radionuclide therapy today is already a fact and not a fiction.

Tumor Immunotargeting Using Innovative Radionuclides

PubMed Central

Kraeber-Bodéré, Françoise; Rousseau, Caroline; Bodet-Milin, Caroline; Mathieu, Cédric; Guérard, François; Frampas, Eric; Carlier, Thomas; Chouin, Nicolas; Haddad, Ferid; Chatal, Jean-François; Faivre-Chauvet, Alain; Chérel, Michel; Barbet, Jacques

2015-01-01

This paper reviews some aspects and recent developments in the use of antibodies to target radionuclides for tumor imaging and therapy. While radiolabeled antibodies have been considered for many years in this context, only a few have reached the level of routine clinical use. However, alternative radionuclides, with more appropriate physical properties, such as lutetium-177 or copper-67, as well as alpha-emitting radionuclides, including astatine-211, bismuth-213, actinium-225, and others are currently reviving hopes in cancer treatments, both in hematological diseases and solid tumors. At the same time, PET imaging, with short-lived radionuclides, such as gallium-68, fluorine-18 or copper-64, or long half-life ones, particularly iodine-124 and zirconium-89 now offers new perspectives in immuno-specific phenotype tumor imaging. New antibody analogues and pretargeting strategies have also considerably improved the performances of tumor immunotargeting and completely renewed the interest in these approaches for imaging and therapy by providing theranostics, companion diagnostics and news tools to make personalized medicine a reality. PMID:25679452

Remediation of Deep Vadose Zone Radionuclide and Metal Contamination: Status and Issues

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dresel, P. Evan; Truex, Michael J.; Cantrell, Keri

2008-12-30

This report documents the results of a PNNL literature review to report on the state of maturity of deep vadose zone remediation technologies for metal contaminants including some radionuclides. Its recommendations feed into decisionmakers need for scientific information and cost-effective in situ remediation technlogies needed under DOE's Environmental Management initiative Enhanced Remediation Methods: Scientific & Technical Basis for In Stu Treatment Systems for Metals and Radionuclides.

Trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations: A review.

PubMed

Olafisoye, O B; Oguntibeju, O O; Osibote, O A

2017-05-03

Oil palm (Elaeisguineensis) is one of the most productive oil producing plant in the world. Crude palm oil is composed of triglycerides supplying the world's need of edible oils and fats. Palm oil also provides essential elements and antioxidants that are potential mediators of cellular functions. Experimental studies have demonstrated the toxicity of the accumulation of significant amounts of nonessential trace elements and radionuclides in palm oil that affects the health of consumers. It has been reported that uptake of trace elements and radionuclides from the oil palm tree may be from water and soil on the palm plantations. In the present review, an attempt was made to revise and access knowledge on the presence of some selected trace elements and radionuclides in palm oil, soil, water, and leaves from oil palm plantations based on the available facts and data. Existing reports show that the presence of nonessential trace elements and radionuclides in palm oil may be from natural or anthropogenic sources in the environment. However, the available literature is limited and further research need to be channeled to the investigation of trace elements and radionuclides in soil, water, leaves, and palm oil from oil palm plantations around the globe.

Present status and trends of radioecological research

NASA Astrophysics Data System (ADS)

Cigna, A. A.; Coughtrey, P. J.; Kirchmann, R.; Polikarpov, G. G.

1999-01-01

Radioecology can be defined as the science concerned with the interactions between radionuclides and the environment and with the effects of radionuclides on man and biotic communities. Ecology advanced from radioecological studies because tracer radionuclides were instrumental in understanding many ecological processes. During the period of fallout from nuclear weapons testing the behaviour of the most important radionuclides (typically:90Sr,131I,137Cs,239,240Pu) in the most critical pathways was studied. After the Chernobyl accident studies were extended to natural and semi-natural ecosystems and to other less common radionuclides. In principle the implementation of radiation protection criteria for man, which are based on the protection of a single individual, assures the protection of organisms other than man. In case of serious contamination scenarios there is a need for realistic evaluations of the effectiveness of the countermeasures that could be undertaken. In particular, studies on biogeochemical transfer mechanisms which control the cycling of radionuclides should be developed. With reference to future developments of the nuclear industry, some attention should be paid to the operation and the releases from, e.g., intrinsically safe reactors and fusion plants. Besides such potential new-type sources, the decontamination and possible site restoration of military installations has to be considered.

Simultaneous determination of specific alpha and beta emitters by LSC-PLS in water samples.

PubMed

Fons-Castells, J; Tent-Petrus, J; Llauradó, M

2017-01-01

Liquid scintillation counting (LSC) is a commonly used technique for the determination of alpha and beta emitters. However, LSC has poor resolution and the continuous spectra for beta emitters hinder the simultaneous determination of several alpha and beta emitters from the same spectrum. In this paper, the feasibility of multivariate calibration by partial least squares (PLS) models for the determination of several alpha ( nat U, 241 Am and 226 Ra) and beta emitters ( 40 K, 60 Co, 90 Sr/ 90 Y, 134 Cs and 137 Cs) in water samples is reported. A set of alpha and beta spectra from radionuclide calibration standards were used to construct three PLS models. Experimentally mixed radionuclides and intercomparision materials were used to validate the models. The results had a maximum relative bias of 25% when all the radionuclides in the sample were included in the calibration set; otherwise the relative bias was over 100% for some radionuclides. The results obtained show that LSC-PLS is a useful approach for the simultaneous determination of alpha and beta emitters in multi-radionuclide samples. However, to obtain useful results, it is important to include all the radionuclides expected in the studied scenario in the calibration set. Copyright © 2016 Elsevier Ltd. All rights reserved.

Calculating Hematopoietic-Mode-Lethality Risk Avoidance Associated with Radionuclide Decorporation Countermeasures Related to a Radiological Terrorism Incident

PubMed Central

Scott, Bobby R.

2009-01-01

This paper provides theoretical health-risk-assessment tools that are designed to facilitate planning for and managing radiological terrorism incidents that involve ingestion exposure to bone-seeking radionuclides (e.g., radiostrontium nuclides). The focus is on evaluating lethality risk avoidance (RAV; i.e., the decrease in risk) that is associated with radionuclide decorporation countermeasures employed to remove ingested bone-seeking beta and/or gamma-emitting radionuclides from the body. To illustrate the application of tools presented, hypothetical radiostrontium decorporation scenarios were considered that involved evaluating the hematopoietic-mode-lethality RAV. For evaluating the efficacy of specific decorporation countermeasures, the lethality risk avoidance proportion (RAP; which is the RAV divided by the total lethality risk in the absence of protective countermeasures) is introduced. The lethality RAP is expected to be a useful tool for designing optimal radionuclide decorporation schemes and for identifying green, yellow and red dose-rate zones. For the green zone, essentially all of the lethality risk is expected to be avoided (RAP = 1) as a consequence of the radionuclide decorporation scheme used. For the yellow zone, some but not all of the lethality risk is expected to be avoided. For the red zone, none of the lethality risk (which equals 1) is expected to be avoided. PMID:20011652

Measurements of natural radionuclides in human teeth and animal bones as markers of radiation exposure from soil in the Northern Malaysian Peninsula

NASA Astrophysics Data System (ADS)

Almayahi, B. A.; Tajuddin, A. A.; Jaafar, M. S.

2014-04-01

This study aimed to estimate the radioactive accumulation of the radionuclides 40K, 137Cs, 210Pb, 226Ra, 228Ra, and 228Th in extracted human teeth, animal bones, and soil. The natural radionuclides were measured by high-purity germanium spectroscopy in extracted human teeth and animal bones from people and animals living in different states in the Northern Malaysian Peninsula. The average 40K, 137Cs, 210Pb, 226Ra, 228Ra, and 228Th concentrations in teeth were found to be 12.31±7.27 Bq g-1, 0.48±0.21 Bq g-1, 0.56±0.21 Bq g-1, 0.55±0.23 Bq g-1, 1.82±1.28 Bq g-1, and 0.50±0.14 Bq g-1, respectively. The corresponding concentrations in bones were found to be 3.79±0.81 Bq g-1, 0.07±0.02 Bq g-1, 0.08±0.02 Bq g-1, 0.16±0.04 Bq g-1, 0.51±1.08 Bq g-1, and 0.06±0.02 Bq g-1, respectively. The corresponding radionuclide concentrations in teeth from smokers were higher than those in non-smokers, and the corresponding radionuclide concentrations were higher in female teeth than in male teeth. The corresponding radionuclide concentrations were higher in teeth than in bones. A positive correlation was found between radionuclides in both teeth and bone samples.

Air Pathway Dose Modeling for the E-Area Low-Level Waste Facility

DOE Office of Scientific and Technical Information (OSTI.GOV)

Dixon, K. L.; Minter, K. M.

2017-09-06

Dose-release factors (DRFs) were calculated for potential atmospheric releases of several radionuclides from the E-Area Low-Level Waste Facility (ELLWF). The ELLWF receives solid low-level radioactive waste from across the Savannah River Site (SRS) and offsite for disposal. These factors represent the maximum dose a receptor would receive if standing at either 100 m or 11,410 m (Site Boundary) from the edge of an ELLWF disposal unit which are points of assessment (POA) for Department of Energy (DOE) Order 435.1 performance assessments (PA). The DRFs were calculated for 1 Ci of the specified radionuclide being released from the ground surface tomore » the atmosphere (mrem per curie released). The calculation conservatively represented the ELLWF as a point source, and conservatively assumed the receptor was positioned at the center of the contaminant plume and continuously exposed for a period of one year. These DRFs can be refined to take into consideration disposal unit size, proximity and timing of peak dose to establish less conservative radionuclide specific disposal limits. DRFs were calculated for H-3 and C-14 in Revision 0 of this report. H-3 as HTO and C-14 as CO 2 were identified as volatile radionuclides of potential concern in earlier radionuclide screening studies. In Revision 1, DRFs were calculated for eight additional radionuclides identified by an updated screening analysis as potentially important volatile radionuclides. These include Ar-37, Ar-39, Ar-42, Hg-194, Hg- 203, Kr-81, Kr-85, and Xe-127.« less

Radionuclide-binding compound, a radionuclide delivery system, a method of making a radium complexing compound, a method of extracting a radionuclide, and a method of delivering a radionuclide

DOEpatents

Fisher, Darrell R.; Wai, Chien M.; Chen, Xiaoyuan

2000-01-01

The invention pertains to compounds which specifically bind radionuclides, and to methods of making radionuclide complexing compounds. In one aspect, the invention includes a radionuclide delivery system comprising: a) a calix[n]arene-crown-[m]-ether compound, wherein n is an integer greater than 3, and wherein m is an integer greater than 3, the calix[n]arene-crown-[m]-ether compound comprising at least two ionizable groups; and b) an antibody attached to the calix[n]arene-crown-[m]-ether compound. In another aspect, the invention includes a method of making a radium complexing compound, comprising: a) providing a calix[n]arene compound, wherein n is an integer greater than 3, the calix[n]arene compound comprising n phenolic hydroxyl groups; b) providing a crown ether precursor, the crown ether precursor comprising a pair of tosylated ends; c) reacting the pair of tosylated ends with a pair of the phenolic hydroxyl groups to convert said pair of phenolic hydroxyl groups to ether linkages, the ether linkages connecting the crown ether precursor to the calix[n]arene to form a calix[n]arene-crown-[m]-ether compound, wherein m is an integer greater than 3; d) converting remaining phenolic hydroxyl groups to esters; e) converting the esters to acids, the acids being proximate a crown-[m]-ether portion of the calix[n]arene-crown-[m]-ether compound; and f) providing a Ra.sup.2+ ion within the crown-[m]-ether portion of the calix[n]arene-crown-[m]-ether compound.

Bio-inspired digital signal processing for fast radionuclide mixture identification

NASA Astrophysics Data System (ADS)

Thevenin, M.; Bichler, O.; Thiam, C.; Bobin, C.; Lourenço, V.

2015-05-01

Countries are trying to equip their public transportation infrastructure with fixed radiation portals and detectors to detect radiological threat. Current works usually focus on neutron detection, which could be useless in the case of dirty bomb that would not use fissile material. Another approach, such as gamma dose rate variation monitoring is a good indication of the presence of radionuclide. However, some legitimate products emit large quantities of natural gamma rays; environment also emits gamma rays naturally. They can lead to false detections. Moreover, such radio-activity could be used to hide a threat such as material to make a dirty bomb. Consequently, radionuclide identification is a requirement and is traditionally performed by gamma spectrometry using unique spectral signature of each radionuclide. These approaches require high-resolution detectors, sufficient integration time to get enough statistics and large computing capacities for data analysis. High-resolution detectors are fragile and costly, making them bad candidates for large scale homeland security applications. Plastic scintillator and NaI detectors fit with such applications but their resolution makes identification difficult, especially radionuclides mixes. This paper proposes an original signal processing strategy based on artificial spiking neural networks to enable fast radionuclide identification at low count rate and for mixture. It presents results obtained for different challenging mixtures of radionuclides using a NaI scintillator. Results show that a correct identification is performed with less than hundred counts and no false identification is reported, enabling quick identification of a moving threat in a public transportation. Further work will focus on using plastic scintillators.

Collective doses to man from dumping of radioactive waste in the Arctic Seas.

PubMed

Nielsen, S P; Iosjpe, M; Strand, P

1997-08-25

A box model for the dispersion of radionuclides in the marine environment covering the Arctic Ocean and the North Atlantic Ocean has been constructed. Collective doses from ingestion pathways have been calculated from unit releases of the radionuclides 3H, 60Co, 63Ni, 90Sr, 129I, 137Cs, 239Pu and 241Am into a fjord on the east coast of NovayaZemlya. The results show that doses for the shorter-lived radionuclides (e.g. 137Cs) are derived mainly from seafood production in the Barents Sea. Doses from the longer-lived radionuclides (e.g. 239Pu) are delivered through marine produce further away from the Arctic Ocean. Collective doses were calculated for two release scenarios, both of which are based on information of the dumping of radioactive waste in the Barents and Kara Seas by the former Soviet Union and on preliminary information from the International Arctic Sea Assessment Programme. A worst-case scenario was assumed according to which all radionuclides in liquid and solid radioactive waste were available for dispersion in the marine environment at the time of dumping. Release of radionuclides from spent nuclear fuel was assumed to take place by direct corrosion of the fuel ignoring the barriers that prevent direct contact between the fuel and the seawater. The second scenario selected assumed that releases of radionuclides from spent nuclear fuel do not occur until after failure of the protective barriers. All other liquid and solid radioactive waste was assumed to be available for dispersion at the time of discharge in both scenarios. The estimated collective dose for the worst-case scenario was about 9 manSv and that for the second scenario was about 3 manSv. In both cases, 137Cs is the radionuclide predicted to dominate the collective doses as well as the peak collective dose rates.

Periodic Verification of the Scaling Factor for Radwastes in Korean NPPs - 13294

DOE Office of Scientific and Technical Information (OSTI.GOV)

Park, Yong Joon; Ahn, Hong Joo; Song, Byoung Chul

2013-07-01

According to the acceptance criteria for a low and intermediate level radioactive waste (LILW) listed in Notice No. 2012-53 of the Nuclear Safety and Security Commission (NSSC), specific concentrations of radionuclides inside a drum has to be identified and quantified. In 5 years of effort, scaling factors were derived through destructive radiochemical analysis, and the dry active waste, spent resin, concentration bottom, spent filter, and sludge drums generated during 2004 ∼ 2008 were evaluated to identify radionuclide inventories. Eventually, only dry active waste among LILWs generated from Korean NPPs were first shipped to a permanent disposal facility on December 2010.more » For the LILWs generated after 2009, the radionuclides are being radiochemically quantified because the Notice clarifies that the certifications of the scaling factors should be verified biennially. During the operation of NPP, the radionuclides designated in the Notice are formed by neutron activation of primary coolant, reactor structural materials, corrosion products, and fission products released into primary coolant through defects or failures in fuel cladding. Eventually, since the radionuclides released into primary coolant are transported into the numerous auxiliary and support systems connected to primary system, the LILWs can be contaminated, and the radionuclides can have various concentration distributions. Thus, radioactive wastes, such as spent resin and dry active waste generated at various Korean NPP sites, were sampled at each site, and the activities of the regulated radionuclides present in the sample were determined using radiochemical methods. The scaling factors were driven on the basis of the activity ratios between a or β-emitting nuclides and γ-emitting nuclides. The resulting concentrations were directly compared with the established scaling factors' data using statistical methods. In conclusions, the established scaling factors were verified with a reliability of within 2σ, and the scaling factors will be applied for newly analyzed LILWs to evaluate the radionuclide inventories. (authors)« less

Tissue radionuclide concentrations in water birds and upland birds on the Hanford Site (USA) from 1971-2009.

PubMed

Delistraty, Damon; Van Verst, Scott

2011-08-01

Historical operations at the Hanford Site (Washington State, USA) have released a wide array of non-radionuclide and radionuclide contaminants into the environment. As a result, there is a need to characterize contaminant effects on site biota. Within this framework, the main purpose of our study was to evaluate radionuclide concentrations in bird tissue, obtained from the Hanford Environmental Information System (HEIS). The database was sorted by avian group (water bird vs. upland bird), radionuclide (over 20 analytes), tissue (muscle, bone, liver), location (onsite vs. offsite), and time period (1971-1990 vs. 1991-2009). Onsite median concentrations in water birds were significantly higher (Bonferroni P < 0.05) than those in onsite upland birds for Cs-137 in muscle (1971-1990) and Sr-90 in bone (1991-2009), perhaps due to behavioral, habitat, or trophic species differences. Onsite median concentrations in water birds were higher (borderline significance with Bonferroni P = 0.05) than those in offsite birds for Cs-137 in muscle (1971-1990). Onsite median concentrations in the earlier time period were significantly higher (Bonferroni P < 0.05) than those in the later time period for Co-60, Cs-137, Eu-152, and Sr-90 in water bird muscle and for Cs-137 in upland bird muscle tissue. Median concentrations of Sr-90 in bone were significantly higher (Bonferroni P < 0.05) than those in muscle for both avian groups and both locations. Over the time period, 1971-2009, onsite median internal dose was estimated for each radionuclide in water bird and upland bird tissues. However, a meaningful dose comparison between bird groups was not possible, due to a dissimilar radionuclide inventory, mismatch of time periods for input radionuclides, and lack of an external dose estimate. Despite these limitations, our results contribute toward ongoing efforts to characterize ecological risk at the Hanford Site. Copyright © 2011 Elsevier Ltd. All rights reserved.

Innovative methodology for intercomparison of radionuclide calibrators using short half-life in situ prepared radioactive sources

DOE Office of Scientific and Technical Information (OSTI.GOV)

Oliveira, P. A.; Santos, J. A. M., E-mail: joao.santos@ipoporto.min-saude.pt; Serviço de Física Médica do Instituto Português de Oncologia do Porto Francisco Gentil, EPE, Porto

2014-07-15

Purpose: An original radionuclide calibrator method for activity determination is presented. The method could be used for intercomparison surveys for short half-life radioactive sources used in Nuclear Medicine, such as{sup 99m}Tc or most positron emission tomography radiopharmaceuticals. Methods: By evaluation of the resulting net optical density (netOD) using a standardized scanning method of irradiated Gafchromic XRQA2 film, a comparison of the netOD measurement with a previously determined calibration curve can be made and the difference between the tested radionuclide calibrator and a radionuclide calibrator used as reference device can be calculated. To estimate the total expected measurement uncertainties, a carefulmore » analysis of the methodology, for the case of{sup 99m}Tc, was performed: reproducibility determination, scanning conditions, and possible fadeout effects. Since every factor of the activity measurement procedure can influence the final result, the method also evaluates correct syringe positioning inside the radionuclide calibrator. Results: As an alternative to using a calibrated source sent to the surveyed site, which requires a relatively long half-life of the nuclide, or sending a portable calibrated radionuclide calibrator, the proposed method uses a source preparedin situ. An indirect activity determination is achieved by the irradiation of a radiochromic film using {sup 99m}Tc under strictly controlled conditions, and cumulated activity calculation from the initial activity and total irradiation time. The irradiated Gafchromic film and the irradiator, without the source, can then be sent to a National Metrology Institute for evaluation of the results. Conclusions: The methodology described in this paper showed to have a good potential for accurate (3%) radionuclide calibrators intercomparison studies for{sup 99m}Tc between Nuclear Medicine centers without source transfer and can easily be adapted to other short half-life radionuclides.« less

The Storage, Transportation, and Disposal of Nuclear Waste

NASA Astrophysics Data System (ADS)

Younker, J. L.

2002-12-01

The U.S. Congress established a comprehensive federal policy to dispose of wastes from nuclear reactors and defense facilities, centered on deep geologic disposal of high-level radioactive waste. Site screening led to selection of three potential sites and in 1987, Congress directed the Secretary of Energy to characterize only one site: Yucca Mountain in Nevada. For more than 20 years, teams of scientists and engineers have been evaluating the potential suitability of the site. On the basis of their work, the U.S. Secretary of Energy, Spencer Abraham, concluded in February 2002 that a safe repository can be sited at Yucca Mountain. On July 23, 2002, President Bush signed Joint Resolution 87 approving the site at Yucca Mountain for development of a repository, which allows the U.S. Department of Energy (DOE) to prepare and submit a license application to the U.S. Nuclear Regulatory Commission (NRC). Concerns have been raised relative to the safe transportation of nuclear materials. The U.S. history of transportation of nuclear materials demonstrates that high-level nuclear materials can be safely transported. Since the 1960s, over 1.6 million miles have been traveled by more than 2,700 spent nuclear fuel shipments, and there has never been an accident severe enough to cause a release of radioactive materials. The DOE will use NRC-certified casks that must be able to withstand very stringent tests. The same design features that allow the casks to survive severe accidents also limit their vulnerability to sabotage. In addition, the NRC will approve all shipping routes and security plans. With regard to long-term safety, the Yucca Mountain disposal system has five key attributes. First, the arid climate and geology of Yucca Mountain combine to ensure that limited water will enter the emplacement tunnels. Second, the DOE has designed a waste package and drip shield that are expected to have very long lifetimes in the repository environment. Third, waste form solubilities limit radionuclide releases, and the invert material below the package would further delay radionuclide movement. Fourth, rock units in the unsaturated and saturated zone at Yucca Mountain will delay and dilute any radionuclides that have migrated away from the emplacement tunnels. Fifth, disruptions due to volcanism, seismic events, or nuclear criticality have been evaluated and all are shown to have very low likelihood of causing unacceptable doses. Volcanism could result in a small, but calculable, dose during the regulatory period of 10,000 years.

Use of Quantity Indicators for Forecasting of Biogeochemical Behavior Sr-90 and Cs-137 in the Conditions of the Combined Pollution of Soils

NASA Astrophysics Data System (ADS)

Lavrentyeva, G. V.; Geshel, I. V.

2012-04-01

From huge number of the radionuclides generated by anthropogenous activity the major value the group of biologically active radionuclides has. First of all, it Sr-90 and Cs-137 which play an important role in various radiological situations. In researches on studying of laws of behavior in environment Sr -90 and Cs-137 the basic attention was given to studying of influence of their chemical analogs Ca and K, instead of stable isotopes Sr and Cs. However, even low concentration of stable isotopes Sr and Cs in soil can influence on biogeochemical behavior of radionuclides. Objects of research: dernovo-podsolic soil, summer barley of grade, stable and radioactive isotopes Sr, Cs. Schemes of experiments provided entering of 8 doses stable Cs and Sr in the range from 0 to 500-750 mg/kg of air-dry weight of soil and 50 kBq of radionuclides on each frequency. Absorption of radionuclides by plants will be defined by two parametres of transport. The first - factor of transition (TF), which characterises level of regulation of process of carrying over of a radionuclide from soil in plants and depends on distribution of an element between the firm and liquid phase, distribution defined in the factor (Kd). The second parametre - factor of concentrating (CF) which characterises biological level of regulation of this process. The increase in quantity of stable Sr in soil leads to an active desorption Sr-90 in a soil solution on all frequency. Kd of Cs-137 on the general background of which decrease in values some increase in factor in the range of 120-225 mg of Cs/kg of soil is observed. Received Kd of radionuclides will well be co-ordinated with the revealed functional dependences between concentration Cs and Sr in soil and specific activity Cs-137 and Sr-90 in a soil solution. Comparison CF of two radionuclides shows that plants absorb Sr-90 from a soil solution actively, than Cs-137. Thus values CF of Sr-90 in the investigated interval of concentration of a stable isotope are in inverse relationship from the element maintenance in a soil solution in all investigated interval of the maintenance of the isotope carrier whereas change similar the indicator for Cs-137 has more difficult dependence. The revealed laws of change of CF studied radionuclides prove to be true the received dependences of accumulation Sr-90 and Cs-137 in barley from specific activity of radionuclides in a soil solution. Values of TF of Sr-90 are in direct dependence on level of the maintenance stable Sr, below similar indicators for Cs-137 in all interval of change of concentration of stable isotopes. It finds reflection in the analysis of functional dependences between concentration of radionuclides in plants and soil. The received values of studied factors completely reflect change of specific activity of radionuclides in a soil solution and their biological availability depending on concentration of their stable isotopes that confirms use possibility in the prognostic purposes of these indicators.

The Dnieper River Aquatic System Radioactive Contamination; Long-tern Natural Attenuation And Remediation History

NASA Astrophysics Data System (ADS)

Voitsekhovych, Oleg; Laptev, Genadiy; Kanivets, Vladimir; Konoplev, Alexey

2013-04-01

Near 27 year passed after the Chernobyl Accident, and the experience gained to study radionuclide behavior in the aquatic systems and to mitigate water contamination are still pose of interest for scientists, society and regulatory austerities. There are different aspects of radionuclide transport in the environment were studied since the Chernobyl fallout in 1986 covered the river catchments, wetlands, river, lakes/reservoirs and reached the Black Sea. The monitoring time series data set and also data on the radionuclides behavior studies in the water bodies (river, lakes and the Black Sea) are available now in Ukraine and other affected countries. Its causation analyses, considering the main geochemical, physical and chemical and hydrological process, governing by radionuclide mobility and transport on the way from the initially contaminated catchments, through the river-reservoir hydrological system to the Black Sea can help in better understanding of the main factors governing be the radionuclide behavior in the environment. Radionuclide washout and its hydrological transport are determined speciation of radionuclides as well as soil types and hydrological mode and also geochemistry and landscape conditions at the affected areas. Mobility and bioavailability of radionuclides are determined by ratio of radionuclide chemical forms in fallout and site-specific environmental characteristics determining rates of leaching, fixation/remobilization as well as sorption-desorption of mobile fraction (its solid-liquid distribution). In many cases the natural attenuation processes governing by the above mentioned processes supported by water flow transportation and sedimentation played the key role in self-rehabilitation of the aquatic ecosystems. The models developed during post-Chernobyl decade and process parameters studies can help in monitoring and remediation programs planed for Fukusima Daichi affected watersheds areas as well. Some most important monitoring data collection results and experience gained during post-Chernobyl decades at the Dnieper River aquatic system are presented (catchments, river and reservoirs). This experience show that only information on radionuclide deposition levels is not enough for accurate predictions on radionuclide wash-out and transport in the hydrological systems. Data on speciation in fallout, rates of transformation processes and site-specific environmental characteristics determining these rates are needed. Information on radionuclide chemical forms, their transformation in other words mobility and bioavailability should be taken into account when rehabilitation and decontamination strategies are developed on local or regional scale. Number of inadequate water protection measures carried out during initial post-accidental period took place because lack of preparedness, data and decision making support tools were in use, Environmental radiation monitoring network has not been developed and huge impact of social stressing and inadequate risk perception took place. Many experimental data, models developed and experience for safe management at the contaminated watersheds and water bodies can be useful and in particular those, who dealing with consequences of Fucusima accident 2011. The paper gives extended overview and describes experience of authors in justification and evaluation of the remedial actions applied after Chernobyl accident with focus on most important lessons learned and potentially utilized in future.

Corrective Action Investigation Plan for Corrective Action Unit 106: Areas 5, 11 Frenchman Flat Atmospheric Sites, Nevada National Security Site, Nevada

DOE Office of Scientific and Technical Information (OSTI.GOV)

Patrick Matthews

2011-07-01

Corrective Action Unit 106 comprises the four corrective action sites (CASs) listed below: • 05-20-02, Evaporation Pond • 05-23-05, Atmospheric Test Site - Able • 05-45-04, 306 GZ Rad Contaminated Area • 05-45-05, 307 GZ Rad Contaminated Area These sites are being investigated because existing information on the nature and extent of potential contamination is insufficient to evaluate and recommend corrective action alternatives (CAAs). Additional information will be obtained by conducting a corrective action investigation before evaluating CAAs and selecting the appropriate corrective action for each CAS. The results of the field investigation will support a defensible evaluation of viablemore » CAAs that will be presented in the Corrective Action Decision Document. The sites will be investigated based on the data quality objectives (DQOs) developed on January 19, 2010, by representatives of the Nevada Division of Environmental Protection and the U.S. Department of Energy (DOE), National Nuclear Security Administration Nevada Site Office. The DQO process was used to identify and define the type, amount, and quality of data needed to develop and evaluate appropriate corrective actions for CAU 106. The presence and nature of contamination at CAU 106 will be evaluated based on information collected from a field investigation. The CAU includes land areas impacted by the release of radionuclides from groundwater pumping during the Radionuclide Migration study program (CAS 05-20-02), a weapons-related airdrop test (CAS 05-23-05), and unknown support activities at two sites (CAS 05-45-04 and CAS 05-45-05). The presence and nature of contamination from surface-deposited radiological contamination from CAS 05-23-05, Atmospheric Test Site - Able, and other types of releases (such as migration and excavation as well as any potential releases discovered during the investigation) from the remaining three CASs will be evaluated using soil samples collected from the locations most likely containing contamination, if present. Appendix A provides a detailed discussion of the DQO methodology and the DQOs specific to each CAS. The scope of the corrective action investigation for CAU 106 includes the following activities: • Conduct radiological surveys. • Collect and submit environmental samples for laboratory analysis to determine internal dose rates and the presence of contaminants of concern. • If contaminants of concern are present, collect additional samples to define the extent of the contamination and determine the area where the total effective dose at the site exceeds final action levels (i.e., corrective action boundary). • Collect samples of investigation-derived waste, as needed, for waste management purposes.« less

Radionuclides in Diagnosis.

ERIC Educational Resources Information Center

Williams, E. D.

1989-01-01

Discussed is a radionuclide imaging technique, including the gamma camera, image analysis computer, radiopharmaceuticals, and positron emission tomography. Several pictures showing the use of this technique are presented. (YP)

Compositions and methods for removal of toxic metals and radionuclides

NASA Technical Reports Server (NTRS)

McKay, David S. (Inventor); Cuero, Raul G. (Inventor)

2007-01-01

The present invention relates to compositions and methods for the removal of toxic metals or radionuclides from source materials. Toxic metals may be removed from source materials using a clay, such as attapulgite or highly cationic bentonite, and chitin or chitosan. Toxic metals may also be removed using volcanic ash alone or in combination with chitin or chitosan. Radionuclides may be removed using volcanic ash alone or in combination with chitin or chitosan.

Derived concentration guideline levels for Argonne National Laboratory's building 310 area.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kamboj, S., Dr.; Yu, C ., Dr.

2011-08-12

The derived concentration guideline level (DCGL) is the allowable residual radionuclide concentration that can remain in soil after remediation of the site without radiological restrictions on the use of the site. It is sometimes called the single radionuclide soil guideline or the soil cleanup criteria. This report documents the methodology, scenarios, and parameters used in the analysis to support establishing radionuclide DCGLs for Argonne National Laboratory's Building 310 area.

Nuclear data for medical applications: An overview of present status and future needs

NASA Astrophysics Data System (ADS)

Syed, M. Qaim

2017-09-01

A brief overview of nuclear data required for medical applications is given. The major emphasis is on radionuclides for internal applications, both for diagnosis and therapy. The status of the presently available data is discussed and some of the emerging needs are outlined. Most of the needs are associated with the development of non-standard positron emitters and novel therapeutic radionuclides. Some new developments in application of radionuclides, e.g. theranostic approach, multimode imaging, radionanoparticles, etc. are described and the related nuclear data needs are discussed. The possible use of newer irradiation technologies for medical radionuclide production, e.g. intermediate energy charged-particle accelerators, high-power electron accelerators for photon production, and spallation neutron sources, will place heavy demands on nuclear data.

Dynamic radionuclide determination of regional left ventricular wall motion using a new digital imaging device

NASA Technical Reports Server (NTRS)

Steele, P.; Kirch, D.

1975-01-01

In 47 men with arteriographically defined coronary artery disease comparative studies of left ventricular ejection fraction and segmental wall motion were made with radionuclide data obtained from the image intensifier camera computer system and with contrast cineventriculography. The radionuclide data was digitized and the images corresponding to left ventricular end-diastole and end-systole were identified from the left ventricular time-activity curve. The left ventricular end-diastolic and end-systolic images were subtracted to form a silhouette difference image which described wall motion of the anterior and inferior left ventricular segments. The image intensifier camera allows manipulation of dynamically acquired radionuclide data because of the high count rate and consequently improved resolution of the left ventricular image.

Validation of a physically based catchment model for application in post-closure radiological safety assessments of deep geological repositories for solid radioactive wastes.

PubMed

Thorne, M C; Degnan, P; Ewen, J; Parkin, G

2000-12-01

The physically based river catchment modelling system SHETRAN incorporates components representing water flow, sediment transport and radionuclide transport both in solution and bound to sediments. The system has been applied to simulate hypothetical future catchments in the context of post-closure radiological safety assessments of a potential site for a deep geological disposal facility for intermediate and certain low-level radioactive wastes at Sellafield, west Cumbria. In order to have confidence in the application of SHETRAN for this purpose, various blind validation studies have been undertaken. In earlier studies, the validation was undertaken against uncertainty bounds in model output predictions set by the modelling team on the basis of how well they expected the model to perform. However, validation can also be carried out with bounds set on the basis of how well the model is required to perform in order to constitute a useful assessment tool. Herein, such an assessment-based validation exercise is reported. This exercise related to a field plot experiment conducted at Calder Hollow, west Cumbria, in which the migration of strontium and lanthanum in subsurface Quaternary deposits was studied on a length scale of a few metres. Blind predictions of tracer migration were compared with experimental results using bounds set by a small group of assessment experts independent of the modelling team. Overall, the SHETRAN system performed well, failing only two out of seven of the imposed tests. Furthermore, of the five tests that were not failed, three were positively passed even when a pessimistic view was taken as to how measurement errors should be taken into account. It is concluded that the SHETRAN system, which is still being developed further, is a powerful tool for application in post-closure radiological safety assessments.

Evidence of the Generation of Isosaccharinic Acids and Their Subsequent Degradation by Local Microbial Consortia within Hyper-Alkaline Contaminated Soils, with Relevance to Intermediate Level Radioactive Waste Disposal

PubMed Central

Rout, Simon P.; Charles, Christopher J.; Garratt, Eva J.; Laws, Andrew P.; Gunn, John; Humphreys, Paul N.

2015-01-01

The contamination of surface environments with hydroxide rich wastes leads to the formation of high pH (>11.0) soil profiles. One such site is a legacy lime works at Harpur Hill, Derbyshire where soil profile indicated in-situ pH values up to pH 12. Soil and porewater profiles around the site indicated clear evidence of the presence of the α and β stereoisomers of isosaccharinic acid (ISA) resulting from the anoxic, alkaline degradation of cellulosic material. ISAs are of particular interest with regards to the disposal of cellulosic materials contained within the intermediate level waste (ILW) inventory of the United Kingdom, where they may influence radionuclide mobility via complexation events occurring within a geological disposal facility (GDF) concept. The mixing of uncontaminated soils with the alkaline leachate of the site resulted in ISA generation, where the rate of generation in-situ is likely to be dependent upon the prevailing temperature of the soil. Microbial consortia present in the uncontaminated soil were capable of surviving conditions imposed by the alkaline leachate and demonstrated the ability to utilise ISAs as a carbon source. Leachate-contaminated soil was sub-cultured in a cellulose degradation product driven microcosm operating at pH 11, the consortia present were capable of the degradation of ISAs and the generation of methane from the resultant H2/CO2 produced from fermentation processes. Following microbial community analysis, fermentation processes appear to be predominated by Clostridia from the genus Alkaliphilus sp, with methanogenesis being attributed to Methanobacterium and Methanomassiliicoccus sp. The study is the first to identify the generation of ISA within an anthropogenic environment and advocates the notion that microbial activity within an ILW-GDF is likely to influence the impact of ISAs upon radionuclide migration. PMID:25748643

Influence of biologically-active substances on {sup 137}Cs and heavy metals uptake by Barley plant

DOE Office of Scientific and Technical Information (OSTI.GOV)

Kruglov, Stanislav; Filipas, Alexander

2007-07-01

Available in abstract form only. Full text of publication follows: When solving the problem of contaminated agricultural lands rehabilitation, most of attention is concentrated on the effective means which allow the obtaining of ecologically safe production. The minimization of radionuclides and heavy metals (HM) content in farm products on the basis of their migration characteristics in agro-landscapes and with the regard for different factors influencing contaminants behavior in the soil-plant system is of great significance. Our investigation has shown that the effect of biologically active substances (BAS) using for seeds treatment on {sup 137}Cs transfer to barley grown on Cdmore » contaminated soil was dependent on their properties and dosage, characteristics of soil contamination and biological peculiarities of plants, including stage of plants development. Seeds treatment by plant growth regulator Zircon resulted in a significant increase in {sup 137}Cs activity in harvest (40- 50%), increase in K concentration and significant reduction in Ca concentration. Increased Cd content in soil reduced {sup 137}Cs transfer to barley plants by 30-60% (p<0,05) and Zircon application further reduced its concentration. Ambiol and El also reduced {sup 137}Cs uptake by roots and Cd and Pb phyto-toxicity. The experimental data do not make it possible to link the BAS effect on inhibition of {sup 137}Cs absorption by plants directly with their influence on HM phyto-toxicity. The dependence of Concentration Ratio of {sup 137}Cs on the Ambiol and El dose was not proportional and the most significant decrease in the radionuclide uptake by plants was reported with the use of dose showing the most pronounced stimulating effect on the barley growth and development. The pre-sowing seed treatment with Ambiol increased Pb absorption by 35-50% and, on the contrary, decreased Cd uptake by plants by 30-40%. (authors)« less

Evidence of the generation of isosaccharinic acids and their subsequent degradation by local microbial consortia within hyper-alkaline contaminated soils, with relevance to intermediate level radioactive waste disposal.

PubMed

Rout, Simon P; Charles, Christopher J; Garratt, Eva J; Laws, Andrew P; Gunn, John; Humphreys, Paul N

2015-01-01

The contamination of surface environments with hydroxide rich wastes leads to the formation of high pH (>11.0) soil profiles. One such site is a legacy lime works at Harpur Hill, Derbyshire where soil profile indicated in-situ pH values up to pH 12. Soil and porewater profiles around the site indicated clear evidence of the presence of the α and β stereoisomers of isosaccharinic acid (ISA) resulting from the anoxic, alkaline degradation of cellulosic material. ISAs are of particular interest with regards to the disposal of cellulosic materials contained within the intermediate level waste (ILW) inventory of the United Kingdom, where they may influence radionuclide mobility via complexation events occurring within a geological disposal facility (GDF) concept. The mixing of uncontaminated soils with the alkaline leachate of the site resulted in ISA generation, where the rate of generation in-situ is likely to be dependent upon the prevailing temperature of the soil. Microbial consortia present in the uncontaminated soil were capable of surviving conditions imposed by the alkaline leachate and demonstrated the ability to utilise ISAs as a carbon source. Leachate-contaminated soil was sub-cultured in a cellulose degradation product driven microcosm operating at pH 11, the consortia present were capable of the degradation of ISAs and the generation of methane from the resultant H2/CO2 produced from fermentation processes. Following microbial community analysis, fermentation processes appear to be predominated by Clostridia from the genus Alkaliphilus sp, with methanogenesis being attributed to Methanobacterium and Methanomassiliicoccus sp. The study is the first to identify the generation of ISA within an anthropogenic environment and advocates the notion that microbial activity within an ILW-GDF is likely to influence the impact of ISAs upon radionuclide migration.

Effect of activities at the Idaho National Engineering and Environmental Laboratory on the water quality of the Snake River Plain aquifer in the Magic Valley study

USGS Publications Warehouse

Bartholomay, Roy C.

1998-01-01

Radiochemical and chemical constituents in wastewater generated at facilities of the Idaho National Engineering and Environmental Laboratory (INEEL) (figure 1) have been discharged to waste-disposal ponds and wells since the early 1950 s. Public concern has been expressed that some of these constituents could migrate through the Snake River Plain aquifer to the Snake River in the Twin Falls-Hagerman area Because of these concerns the U.S. Department of Energy (DOE) requested that the U.S. Geological Survey (USGS) conduct three studies to gain a greater understanding of the chemical quality of water in the aquifer. One study described a one-time sampling effort for radionuclides, trace elements, and organic compounds in the eastern part of the A&B Irrigation District in Minidoka County (Mann and Knobel, 1990). Another ongoing study involves sampling for tritium from 19 springs on the north side of the Snake River in the Twin Falls-Hagerman area (Mann, 1989; Mann and Low, 1994). A third study an ongoing annual sampling effort in the area between the southern boundary of the INEEL and Hagerman (figure 1) (hereafter referred to as the Magic Valley study area), is being conducted with the Idaho Department of Water Resources in cooperation with the DOE. Data for a variety of radiochemical and chemical constituents from this study have been published by Wegner and Campbell (1991); Bartholomay, Edwards, and Campbell (1992, 1993, 1994a, 1994b); and Bartholomay, Williams, and Campbell (1995, 1996, 1997b). Data discussed in this fact sheet were taken from these reports. An evaluation of data collected during the first four years of this study (Bartholomay Williams, and Campbell, 1997a) showed no pattern of water-quality change for radionuclide data as concentrations randomly increased or decreased. The inorganic constituent data showed no statistical change between sample rounds.

Scenario for the safety assessment of near surface radioactive waste disposal in Serpong, Indonesia

DOE Office of Scientific and Technical Information (OSTI.GOV)

Purnomo, A.S.

2007-07-01

Near surface disposal has been practiced for some decades, with a wide variation in sites, types and amounts of wastes, and facility designs employed. Experience has shown that the effective and safe isolation of waste depends on the performance of the overall disposal system, which is formed by three major components or barriers: the site, the disposal facility and the waste form. The objective of radioactive waste disposal is to isolate waste so that it does not result in undue radiation exposure to humans and the environment. In near surface disposal, the disposal facility is located on or below themore » ground surface, where the protective covering is generally a few meters thick. These facilities are intended to contain low and intermediate level waste without appreciable quantities of long-lived radionuclides. Safety is the most important aspect in the applications of nuclear technology and the implementation of nuclear activities in Indonesia. This aspect is reflected by a statement in the Act Number 10 Year 1997, that 'The Development and use of nuclear energy in Indonesia has to be carried out in such away to assure the safety and health of workers, the public and the protection of the environment'. Serpong are one of the sites for a nuclear research center facility, it is the biggest one in Indonesia. In the future will be developed the first near surface disposal on site of the nuclear research facility in Serpong. The paper will mainly focus on scenario of the safety assessments of near-surface radioactive waste disposal is often important to evaluate the performance of the disposal system (disposal facility, geosphere and biosphere). It will give detail, how at the present and future conditions, including anticipated and less probable events in order to prevent radionuclide migration to human and environment. Refer to the geology characteristic and ground water table is enable to place something Near Surface Disposal on unsaturated zone in Serpong site. (authors)« less

Reconstruction of radionuclide intakes for the residents of East Urals Radioactive Trace (1957–2011)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Tolstykh, Evgenia I.; Peremyslova, Lyudmila M.; Degteva, Marina O.

The East Urals Radioactive Trace (EURT) was formed after a chemical explosion in the radioactive waste-storage facility of the Mayak Production Association in 1957 (Southern Urals, Russia) and resulted in an activity dispersion of 7.4 × 10 16 Bq into the atmosphere. Internal exposure due to ingestion of radionuclides with local foodstuffs was the main factor of public exposure at the EURT. The EURT cohort, combining residents of most contaminated settlements, was formed for epidemiological study at the Urals Research Center for Radiation Medicine, Russia (URCRM). For the purpose of improvement of radionuclide intake estimates for cohort members, the followingmore » data sets collected in URCRM were used: (1) Total β-activity and radiochemical measurements of 90Sr in local foodstuffs over all of the period of interest (1958–2011; n = 2200), which were used for relative 90Sr intake estimations. (2) 90Sr measurements in human bones and whole body ( n = 338); these data were used for average 90Sr intake derivations using an age- and gender-dependent Sr-biokinetic model. Non-strontium radionuclide intakes were evaluated on the basis of 90Sr intake data and the radionuclide composition of contaminated foodstuffs. Validation of radionuclide intakes during the first years after the accident was first carried out using measurements of the feces β-activity of EURT residents ( n = 148). The comparison of experimental and reconstructed values of feces β-activity shows good agreement. 90Sr intakes for residents of settlements evacuated 7–14 days after the accident were also obtained from 90Sr measurements in human bone and whole body. Furthermore, the results of radionuclide intake reconstruction will be used to estimate the internal doses for the members of the EURT cohort.« less

Soil plutonium and cesium in stream channels and banks of Los Alamos liquid effluent-receiving areas.

PubMed

Nyhan, J W; White, G C; Trujillo, G

1982-10-01

Stream channel sediments and adjacent bank soils found in three intermittent streams used for treated liquid effluent disposal at Los Alamos, New Mexico were sampled to determine the distribution of 238Pu, 239,240Pu and 137Cs. Radionuclide concentrations and inventories were determined as functions of distance downstream from the waste outfall and from the center of the stream channel, soil sampling depth, stream channel-bank physiography, and the waste use history of each disposal area. Radionuclide concentrations in channel sediments were inversely related to distances up to 10 km downstream from the outfalls. For sites receiving appreciable waste effluent additions, contaminant concentrations in bank soils decreased with perpendicular distances greater than 0.38 m from the stream channel, and with stream bank sampling depths greater than 20-40 cm. Concentrations and total inventories of radionuclides in stream bank soils generally decreased as stream bank height increased. Inventory estimates of radionuclides in channel sediments exhibited coefficients of variation that ranged 0.41-2.6, reflecting the large variation in radionuclide concentrations at each site. Several interesting temporal relationships of these radionuclides in intermittent streams were gleaned from the varying waste use histories of the three effluent-receiving areas. Eleven yr after liquid wastes were added to one canyon, the major radionuclide inventories were found in the stream bank soils, unlike most of the other currently-used receiving areas. A period of time greater than 6 yr seems to be required before the plutonium in liquid wastes currently added to the canyon is approximately equilibrated with the plutonium in the bank soils. These observations are discussed relative to waste management practices in these southwestern intermittent streams.

Annual limits on intake (ALI) values in ICRP 61 and 10 CFR Part 20 (1991)

DOE Office of Scientific and Technical Information (OSTI.GOV)

Zhu, M.; Kearfott, K.J.

The newest major revision of Nuclear Regulatory Commission`s 10 CFR Part 20 (1991) incorporates the new dose methodology system, revised limits, and improved internal dose computations presented in International Commission on Radiation Protection (ICRP) Publication 30 (1979). A year before the issue of this revised 10 CFR Part 20, the ICRP dispatched Publication 61 (1990). This new ICRP report employed different dose limits, in addition to incorporating more recent biological information and variations in physiological and different tissue weighing factors for various organs. An investigation of the numerical differences in the Annual Limit on Intake (ALI) reported in this moremore » recent international regulations and those of the new regulations was thus undertaken. Overall means, medians, modes, maximum, minimum, and ranges of the percent changes are almost identical for ingestion and inhalation, although the percent difference between 10 CFR and ICRP Publication 61 showed minor differences for individual radionuclides. Approximately 334 of 1,351 radionuclides for inhalation and 173 of 771 radionuclides for ingestion have much less restrictive ALIs in the new ICRP recommendations than in the old, with some of those limits increased by at least a factor of two. Approximately 51% of the radionuclides for ingestion intake and 48% of radionuclides for inhalation intake showed changes of greater than 25%. The radionuclides observed to have much less restrictive ALIs are primarily the radionuclides of thorium, mercury, plutonium, uranium, and americium which have short effective clearance rates. While many countries have already applied the ICRP 61 recommendations to their radiation protection standards, using the ICRP 30 recommendation in the United States does not match the international standards even when the values of the ALIs are adjusted for differences in dose limits.« less

Doses of external exposure in Jordan house due to gamma-emitting natural radionuclides in building materials.

PubMed

Al-Jundi, J; Ulanovsky, A; Pröhl, G

2009-10-01

The use of building materials containing naturally occurring radionuclides as (40)K, (232)Th, and (238)U and their progeny results in external exposures of the residents of such buildings. In the present study, indoor dose rates for a typical Jordan concrete room are calculated using Monte Carlo method. Uniform chemical composition of the walls, floor and ceiling as well as uniform mass concentrations of the radionuclides in walls, floor and ceiling are assumed. Using activity concentrations of natural radionuclides typical for the Jordan houses and assuming them to be in secular equilibrium with their progeny, the maximum annual effective doses are estimated to be 0.16, 0.12 and 0.22 mSv a(-1) for (40)K, (232)Th- and (238)U-series, respectively. In a total, the maximum annual effective indoor dose due to external gamma-radiation is 0.50 mSv a(-1). Additionally, organ dose coefficients are calculated for all organs considered in ICRP Publication 74. Breast, skin and eye lenses have the maximum equivalent dose rate values due to indoor exposures caused by the natural radionuclides, while equivalent dose rates for uterus, colon (LLI) and small intestine are found to be the smallest. More specifically, organ dose rates (nSv a(-1)per Bq kg(-1)) vary from 0.044 to 0.060 for (40)K, from 0.44 to 0.60 for radionuclides from (238)U-series and from 0.60 to 0.81 for radionuclides from (232)Th-series. The obtained organ and effective dose conversion coefficients can be conveniently used in practical dose assessment tasks for the rooms of similar geometry and varying activity concentrations and local-specific occupancy factors.

Reconstruction of radionuclide intakes for the residents of East Urals Radioactive Trace (1957–2011)

DOE PAGES

Tolstykh, Evgenia I.; Peremyslova, Lyudmila M.; Degteva, Marina O.; ...

2017-01-19

The East Urals Radioactive Trace (EURT) was formed after a chemical explosion in the radioactive waste-storage facility of the Mayak Production Association in 1957 (Southern Urals, Russia) and resulted in an activity dispersion of 7.4 × 10 16 Bq into the atmosphere. Internal exposure due to ingestion of radionuclides with local foodstuffs was the main factor of public exposure at the EURT. The EURT cohort, combining residents of most contaminated settlements, was formed for epidemiological study at the Urals Research Center for Radiation Medicine, Russia (URCRM). For the purpose of improvement of radionuclide intake estimates for cohort members, the followingmore » data sets collected in URCRM were used: (1) Total β-activity and radiochemical measurements of 90Sr in local foodstuffs over all of the period of interest (1958–2011; n = 2200), which were used for relative 90Sr intake estimations. (2) 90Sr measurements in human bones and whole body ( n = 338); these data were used for average 90Sr intake derivations using an age- and gender-dependent Sr-biokinetic model. Non-strontium radionuclide intakes were evaluated on the basis of 90Sr intake data and the radionuclide composition of contaminated foodstuffs. Validation of radionuclide intakes during the first years after the accident was first carried out using measurements of the feces β-activity of EURT residents ( n = 148). The comparison of experimental and reconstructed values of feces β-activity shows good agreement. 90Sr intakes for residents of settlements evacuated 7–14 days after the accident were also obtained from 90Sr measurements in human bone and whole body. Furthermore, the results of radionuclide intake reconstruction will be used to estimate the internal doses for the members of the EURT cohort.« less

Sources and pathways of artificial radionuclides to soils at a High Arctic site.

PubMed

Lokas, E; Bartmiński, P; Wachniew, P; Mietelski, J W; Kawiak, T; Srodoń, J

2014-11-01

Activity concentrations, inventories and activity ratios of (137)Cs, (238)Pu, (239 + 240)Pu and (241)Am in soil profiles were surveyed in the dry tundra and the adjoining proglacial zones of glaciers at a High Arctic site on Svalbard. Vertical profiles of radionuclide activities were determined in up to 14-cm-thick soil sequences. Additionally, soil properties (pH, organic matter, texture, mineral composition and sorption capacity) were analyzed. Results obtained in this study revealed a large range of activity concentrations and inventories of the fallout radionuclides from the undetectable to the uncommonly high levels (inventories of 30,900 ± 940, 47 ± 6, 886 ± 80 and 296 ± 19 Bq/m(2) for (137)Cs, (238)Pu, (239 + 240)Pu and (241)Am, respectively) found in two profiles from the proglacial zone. Concentration of these initially airborne radionuclides in the proglacial zone soils is related to their accumulation in cryoconites that have a large ability to concentrate trace metals. The cryoconites develop on the surface of glaciers, and the material they accumulate is deposited on land surface after the glaciers retreat. The radionuclide inventories in the tundra soils, which effectively retain radionuclides due to high organic matter contents, were comparable to the global fallout deposition for this region of the world. The (238)Pu/(239 + 240)Pu activity ratios for tundra soils suggested global fallout as the dominant source of Pu. The (238)Pu/(239 + 240)Pu and (239 + 240)Pu/(137)Cs activity ratios in the proglacial soils pointed to possible contributions of these radionuclides from other, unidentified sources.

Video instrumentation for radionuclide angiocardiography.

NASA Technical Reports Server (NTRS)

Kriss, J. P.

1973-01-01

Two types of videoscintiscopes for performing radioisotopic angiocardiography with a scintillation camera are described, and use of these instruments in performing clinical studies is illustrated. Radionuclide angiocardiography is a simple, quick and accurate procedure recommended as a screening test for patients with a variety of congenital and acquired cardiovascular lesions. When performed in conjunction with coronary arterial catheterization, dynamic radionuclide angiography may provide useful information about regional myocardial perfusion. Quantitative capabilities greatly enhance the potential of this diagnostic tool.

Radionuclidic purity measurements for cyclotron-produced 99mTc via 100Mo(p,2n) at 18 MeV

NASA Astrophysics Data System (ADS)

Buckley, K.; Tanguay, J.; Hou, X.; Stothers, L.; Vuckovic, M.; Frantzen, K.; Cockburn, N.; Corsaut, J.; Dodd, M.; Goodbody, A.; Hanemaayer, V.; Hook, B.; Klug, J.; Kovacs, M.; Kumlin, J.; McDiarmid, S.; McEwan, J.; Prato, F.; Ruddock, P.; Valiant, J.; Zeisler, S.; Ruth, T.; Celler, A.; Benard, F.; Schaffer, P.

2017-05-01

The radionuclidic purity of cyclotron-produced 99mTc has been measured by gamma ray spectroscopy and compared to the results of a quick release test modeled after the molybdenum breakthrough test performed on generator-derived 99mTc. Excellent radionuclidic purity is reported for samples produced at BCCA during our clinical trial. The quick release test results agree well with the gamma ray analysis.

Effects on radionuclide concentrations by cement/ground-water interactions in support of performance assessment of low-level radioactive waste disposal facilities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Krupka, K.M.; Serne, R.J.

The US Nuclear Regulatory Commission is developing a technical position document that provides guidance regarding the performance assessment of low-level radioactive waste disposal facilities. This guidance considers the effects that the chemistry of the vault disposal system may have on radionuclide release. The geochemistry of pore waters buffered by cementitious materials in the disposal system will be different from the local ground water. Therefore, the cement-buffered environment needs to be considered within the source term calculations if credit is taken for solubility limits and/or sorption of dissolved radionuclides within disposal units. A literature review was conducted on methods to modelmore » pore-water compositions resulting from reactions with cement, experimental studies of cement/water systems, natural analogue studies of cement and concrete, and radionuclide solubilities experimentally determined in cement pore waters. Based on this review, geochemical modeling was used to calculate maximum concentrations for americium, neptunium, nickel, plutonium, radium, strontium, thorium, and uranium for pore-water compositions buffered by cement and local ground-water. Another literature review was completed on radionuclide sorption behavior onto fresh cement/concrete where the pore water pH will be greater than or equal 10. Based on this review, a database was developed of preferred minimum distribution coefficient values for these radionuclides in cement/concrete environments.« less

Radionuclide injury to the lung.

PubMed Central

Dagle, G E; Sanders, C L

1984-01-01

Radionuclide injury to the lung has been studied in rats, hamsters, dogs, mice and baboons. Exposure of the lung to high dose levels of radionuclides produces a spectrum of progressively more severe functional and morphological changes, ranging from radiation pneumonitis and fibrosis to lung tumors. These changes are somewhat similar for different species. Their severity can be related to the absorbed radiation dose (measured in rads) produced by alpha, beta or gamma radiation emanating from various deposited radionuclides. The chemicophysical forms of radionuclides and spatial-temporal factors are also important variables. As with other forms of injury to the lung, repair attempts are highlighted by fibrosis and proliferation of pulmonary epithelium. Lung tumors are the principal late effect observed in experimental animals following pulmonary deposition of radionuclides at dose levels that do not result in early deaths from radiation pneumonitis or fibrosis. The predominant lung tumors described have been of epithelial origin and have been classified, in decreasing frequency of occurrence, as adenocarcinoma, bronchioloalveolar carcinoma, epidermoid carcinomas and combined epidermoid and adenocarcinoma. Mesothelioma and fibrosarcoma have been observed in rats, but less commonly in other species. Hemangiosarcomas were frequency observed in dogs exposed to beta-gamma emitters, and occasionally in rats exposed to alpha emitters. These morphologic changes in the lungs of experimental animals were reviewed and issues relevant to the prediction of human hazards discussed. PMID:6376095

Soil and vegetation influence in plants natural radionuclides uptake at a uranium mining site

NASA Astrophysics Data System (ADS)

Charro, E.; Moyano, A.

2017-12-01

The main objective of this work is to investigate the uptake of several radionuclides by the vegetation characteristic of a dehesa ecosystem in uranium mining-impacted soils in Central-West of Spain. The activity concentration for 238U, 226Ra, 210Pb, 232Th, and 224Ra was measured in soil and vegetation samples using a Canberra n-type HPGe gamma-ray spectrometer. Transfer factors of natural radionuclides in different tissues (leaves, branches, twigs, and others) of native plants were evaluated. From these data, the influence of the mine, the physicochemical parameters of the soils and the type of vegetation were analyzed in order to explain the accumulation of radionuclides in the vegetation. A preferential uptake of 210Pb and 226Ra by plants, particularly by trees of the Quercus species (Quercus pyrenaica and Quercus ilex rotundifolia), has been observed, being the transfer factors for 226Ra and 210Pb in these tree species higher than those for other plants (like Pinus pinaster, Rubur ulmifolius and Populus sp.). The analysis of radionuclide contents and transfer factors in the vegetation showed no evidence of influence of the radionuclide concentration in soils, although it could be explained in terms of the type of plants and, in particular, of the tree's species, with special attention to the tree's rate of growth, being higher in slow growing species.

Dispersion of Fukushima radionuclides in the global atmosphere and the ocean.

PubMed

Povinec, P P; Gera, M; Holý, K; Hirose, K; Lujaniené, G; Nakano, M; Plastino, W; Sýkora, I; Bartok, J; Gažák, M

2013-11-01

Large quantities of radionuclides were released in March-April 2011 during the accident of the Fukushima Dai-ichi Nuclear Power Plant to the atmosphere and the ocean. Atmospheric and marine modeling has been carried out to predict the dispersion of radionuclides worldwide, to compare the predicted and measured radionuclide concentrations, and to assess the impact of the accident on the environment. Atmospheric Lagrangian dispersion modeling was used to simulate the dispersion of (137)Cs over America and Europe. Global ocean circulation model was applied to predict the dispersion of (137)Cs in the Pacific Ocean. The measured and simulated (137)Cs concentrations in atmospheric aerosols and in seawater are compared with global fallout and the Chernobyl accident, which represent the main sources of the pre-Fukushima radionuclide background in the environment. The radionuclide concentrations in the atmosphere have been negligible when compared with the Chernobyl levels. The maximum (137)Cs concentration in surface waters of the open Pacific Ocean will be around 20 Bq/m(3). The plume will reach the US coast 4-5 y after the accident, however, the levels will be below 3 Bq/m(3). All the North Pacific Ocean will be labeled with Fukushima (137)Cs 10 y after the accident with concentration bellow 1 Bq/m(3). Copyright © 2013 Elsevier Ltd. All rights reserved.

Exposure to radionuclides in smoke from vegetation fires.

PubMed

Carvalho, Fernando P; Oliveira, João M; Malta, Margarida

2014-02-15

Naturally occurring radionuclides of uranium, thorium, radium, lead and polonium were determined in bushes and trees and in the smoke from summer forest fires. Activity concentrations of radionuclides in smoke particles were much enriched when compared to original vegetation. Polonium-210 ((210)Po) in smoke was measured in concentrations much higher than all other radionuclides, reaching 7,255 ± 285 Bq kg(-1), mostly associated with the smaller size smoke particles (<1.0 μm). Depending on smoke particle concentration, (210)Po in surface air near forest fires displayed volume concentrations up to 70 m Bq m(-3), while in smoke-free air (210)Po concentration was about 30 μ Bq m(-3). The estimated absorbed radiation dose to an adult member of the public or a firefighter exposed for 24h to inhalation of smoke near forest fires could exceed 5 μSv per day, i.e, more than 2000 times above the radiation dose from background radioactivity in surface air, and also higher than the radiation dose from (210)Po inhalation in a chronic cigarette smoker. It is concluded that prolonged exposure to smoke allows for enhanced inhalation of radionuclides associated with smoke particles. Due to high radiotoxicity of alpha emitting radionuclides, and in particular of (210)Po, the protection of respiratory tract of fire fighters is strongly recommended. Copyright © 2013 Elsevier B.V. All rights reserved.

Cryoconites from Alpine glaciers: Radionuclide accumulation and age estimation with Pu and Cs isotopes and 210Pb.

PubMed

Wilflinger, T; Lettner, H; Hubmer, A; Bossew, P; Sattler, B; Slupetzky, H

2018-06-01

Cryoconites ("cold dust", derived from the Greek) are aeolian sediments accumulated on glacier surfaces. In cryoconites from the surface of the Stubacher Sonnblickkees, a temperate Austrian glacier, extremely high activity concentrations of artificial and natural radionuclides were found. Artificial radionuclides stem from two clearly distinguishable sources, global fallout from the nuclear weapons testing era deposited over a period of years until roughly 1966 and the fallout from Chernobyl in 1986, which was essentially deposited as a single input during one week. Anthropogenic radionuclides identified were 137 Cs, 134 Cs, 238 Pu, 239+240 Pu, 90 Sr, 241 Am, 60 Co, 125 Sb, 154 Eu, and 207 Bi. The naturally occurring radionuclides detected were the long-lived radon decay product 210 Pb, the primordial radionuclide 4  K and the cosmogenic 7 Be. Isotopic ratios of 134 Cs/ 137 Cs and 239+240 Pu/ 238 Pu were used to separate the nuclide inventory into the contributions of the two aforementioned sources, which show varying degrees of mixing and provide information on the mixing age of the cryoconites. Since isotopic ratios of Pu often have high uncertainties due to low absolute concentrations, age estimation based on this method can be quite inaccurate. Additional information about the age of cryoconites was obtained through analysis of 210 Pb, which is constantly deposited over time. Copyright © 2017. Published by Elsevier Ltd.

TH-AB-206-01: Advances in Radionuclide Therapy - From Radioiodine to Nanoparticles

DOE Office of Scientific and Technical Information (OSTI.GOV)

Humm, J.

In the past few decades, the field of nuclear medicine has made long strides with the continued advancement of related sciences and engineering and the availability of diagnostic and therapeutic radionuclides. Leveraging these advancements while combining the advantages of therapeutic and diagnostic radionuclides into one radiopharmaceutical has also created a new subfield “theranostics” in nuclear medicine that has the potential to further propel the field into the future. This session is composed of two talks; one focused on the physics principles of theranostics from properties of beta and alpha emitting radionuclides to dosimetric models and quantification; while the second describesmore » preclinical and clinical applications of theranostics and discusses the challenges and opportunities of bringing them to the clinic. At the end of the session the listener should be able to identify: The different properties of beta and alpha emitting radionuclides Which radionuclides are selected for which nuclear medicine therapies and why How PET can be used to accurately quantify the uptake of tumor targeting molecules How individualized dosimetry can be performed from the management of thyroid cancer to novel radiolabeled antibody therapies Promising pre-clinical radiopharmaceutical pairs in prostate cancer and melanoma. Promising clinical Theranostics in neuroendocrine cancers. Challenges of bringing Theranostics to the clinic. E. Delpassand, RITA Foundation -Houston; SBIR Grant; CEO and share holder of RadioMedix.« less

Mathematical Basis and Test Cases for Colloid-Facilitated Radionuclide Transport Modeling in GDSA-PFLOTRAN

DOE Office of Scientific and Technical Information (OSTI.GOV)

Reimus, Paul William

This report provides documentation of the mathematical basis for a colloid-facilitated radionuclide transport modeling capability that can be incorporated into GDSA-PFLOTRAN. It also provides numerous test cases against which the modeling capability can be benchmarked once the model is implemented numerically in GDSA-PFLOTRAN. The test cases were run using a 1-D numerical model developed by the author, and the inputs and outputs from the 1-D model are provided in an electronic spreadsheet supplement to this report so that all cases can be reproduced in GDSA-PFLOTRAN, and the outputs can be directly compared with the 1-D model. The cases include examplesmore » of all potential scenarios in which colloid-facilitated transport could result in the accelerated transport of a radionuclide relative to its transport in the absence of colloids. Although it cannot be claimed that all the model features that are described in the mathematical basis were rigorously exercised in the test cases, the goal was to test the features that matter the most for colloid-facilitated transport; i.e., slow desorption of radionuclides from colloids, slow filtration of colloids, and equilibrium radionuclide partitioning to colloids that is strongly favored over partitioning to immobile surfaces, resulting in a substantial fraction of radionuclide mass being associated with mobile colloids.« less

Radionuclides from past uranium mining in rivers of Portugal.

PubMed

Carvalho, Fernando P; Oliveira, João M; Lopes, Irene; Batista, Aleluia

2007-01-01

During several decades and until a few years ago, uranium mines were exploited in the Centre of Portugal and wastewaters from uranium ore milling facilities were discharged into river basins. To investigate enhancement of radioactivity in freshwater ecosystems, radionuclides of uranium and thorium series were measured in water, sediments, suspended matter, and fish samples from the rivers Vouga, Dão, Távora and Mondego. The results show that these rivers carry sediments with relatively high naturally occurring radioactivity, and display relatively high concentrations of radon dissolved in water, which is typical of a uranium rich region. Riverbed sediments show enhanced concentrations of radionuclides in the mid-section of the Mondego River, a sign of past wastewater discharges from mining and milling works at Urgeiriça confirmed by the enhanced values of (238)U/(232)Th radionuclide ratios in sediments. Radionuclide concentrations in water, suspended matter and freshwater fish from that section of Mondego are also enhanced in comparison with concentrations measured in other rivers. Based on current radionuclide concentrations in fish, regular consumption of freshwater species by local populations would add 0.032 mSv a(-1) of dose equivalent (1%) to the average background radiation dose. Therefore, it is concluded that current levels of enhanced radioactivity do not pose a significant radiological risk either to aquatic fauna or to freshwater fish consumers.

Agriculture in an area impacted by past uranium mining activities

DOE Office of Scientific and Technical Information (OSTI.GOV)

Carvalho, F. P.; Oliveira, J. M.; Neves, O.

2007-07-01

The shallow aquifer near the old Cunha Baixa uranium mine (Viseu, Portugal) was contaminated by acid mine drainage. Concentration of radionuclides in water from irrigation wells and in the topsoil layer of the agriculture fields nearby display enhanced concentrations of uranium, radium and polonium. Two types of agriculture land in this area were selected, one with enhanced and another with low uranium concentrations, for controlled growth of lettuce and potatoes. Plants were grown in replicate portions of land (two plots) in each soil type and were periodically irrigated with water from wells. In each soil, one plot was irrigated withmore » water containing low concentration of dissolved uranium and the other plot with water containing enhanced concentration of dissolved uranium. At the end of the growth season, plants were harvested and analysed, along with soil and irrigation water samples. Results show the accumulation of radionuclides in edible parts of plants, specially in the field plots with higher radionuclide concentrations in soil. Radionuclides in irrigation water contributed less to the radioactivity accumulated in plants than radionuclides from soils. (authors)« less

Fukushima radionuclides in the NW Pacific, and assessment of doses for Japanese and world population from ingestion of seafood

PubMed Central

Povinec, Pavel P.; Hirose, Katsumi

2015-01-01

Variations of Fukushima-derived radionuclides (90Sr, 134Cs and 137Cs) in seawater and biota offshore Fukushima and in the NW Pacific Ocean were investigated and radiation doses to the Japanese and world population from ingestion of seafood contaminated by Fukushima radionuclides were estimated and compared with those from other sources of anthropogenic and natural radionuclides. The total effective dose commitment from ingestion of radionuclides in fish, shellfish and seaweed caught in coastal waters off Fukushima was estimated to be 0.6 ± 0.4 mSv/y. The individual effective dose commitment from consumption of radioactive-contaminated fish caught in the open Pacific Ocean was estimated to be 0.07 ± 0.05 mSv/y. These doses are comparable or much lower than doses delivered from the consumption of natural 210Po in fish and in shellfish (0.7 mSv/y). The estimated individual doses have been below the levels when any health damage of the Japanese and world population could be expected. PMID:25761420

Bifunctional Coupling Agents for Radiolabeling of Biomolecules and Target-Specific Delivery of Metallic Radionuclides

PubMed Central

Liu, Shuang

2008-01-01

Receptor-based radiopharmaceuticals are of great current interest in early molecular imaging and radiotherapy of cancers, and provide a unique tool for target-specific delivery of radionuclides to the diseased tissues. In general, a target-specific radiopharmaceutical can be divided into four parts: targeting biomolecule (BM), pharmacokinetic modifying (PKM) linker, bifunctional coupling or chelating agent (BFC), and radionuclide. The targeting biomolecule serves as a “carrier” for specific delivery of the radionuclide. PKM linkers are used to modify radiotracer excretion kinetics. BFC is needed for radiolabeling of biomolecules with a metallic radionuclide. Different radiometals have significant difference in their coordination chemistry, and require BFCs with different donor atoms and chelator frameworks. Since the radiometal chelate can have a significant impact on physical and biological properties of the target-specific radiopharmaceutical, its excretion kinetics can be altered by modifying the coordination environment with various chelators or coligand, if needed. This review will focus on the design of BFCs and their coordination chemistry with technetium, copper, gallium, indium, yttrium and lanthanide radiometals. PMID:18538888

[Ranking of radionuclides and pathways according to their contribution to the dose burden to the population resulting from NPP releases].

PubMed

Spiridonov, S I; Karpenko, E I; Sharpan, L A

2013-01-01

Approaches are described towards estimating the consequences of radioactive contamination of ecosystems by nuclear fuel cycle enterprises with the rationale for the optimal specification level for nuclear power plants (NPP) operating in the normal mode. Calculations are made based on the initial data of the IAEA project, INPRO ENV, dealing with the ranking of radionuclides escaping to the environment from the operating NPPs. Influence of various factors on rankings of radionuclides and pathways of public exposure is demon- strated. An important factor is the controlled radionuclide composition of atmospheric NPP releases. It has been found that variation in the dose coefficients for some radionuclides leads to significant changes not only in the ranking results but also in the estimates of total dose burdens. Invariability is shown of the estimation concerning the greatest contribution of the peroral route to the population dose of irradiation in the situation considered. A conclusion was drawn on the need of taking into consideration uncertainties of different factors when comparing effects on the environment from enterprises of conventional and innovative nuclear fuel cycles.

Fukushima radionuclides in the NW Pacific, and assessment of doses for Japanese and world population from ingestion of seafood.

PubMed

Povinec, Pavel P; Hirose, Katsumi

2015-03-12

Variations of Fukushima-derived radionuclides ((90)Sr, (134)Cs and (137)Cs) in seawater and biota offshore Fukushima and in the NW Pacific Ocean were investigated and radiation doses to the Japanese and world population from ingestion of seafood contaminated by Fukushima radionuclides were estimated and compared with those from other sources of anthropogenic and natural radionuclides. The total effective dose commitment from ingestion of radionuclides in fish, shellfish and seaweed caught in coastal waters off Fukushima was estimated to be 0.6 ± 0.4 mSv/y. The individual effective dose commitment from consumption of radioactive-contaminated fish caught in the open Pacific Ocean was estimated to be 0.07 ± 0.05 mSv/y. These doses are comparable or much lower than doses delivered from the consumption of natural (210)Po in fish and in shellfish (0.7 mSv/y). The estimated individual doses have been below the levels when any health damage of the Japanese and world population could be expected.

Understanding Radionuclide Interactions with Layered Materials

NASA Astrophysics Data System (ADS)

Wang, Y.

2015-12-01

Layered materials play an important role in nuclear waste management and environmental cleanup. Better understanding of radionuclide interactions with those materials is critical for engineering high-performance materials for various applications. This presentation will provide an overview on radionuclide interactions with two general categories of layered materials - cationic clays and anionic clays - from a perspective of nanopore confinement. Nanopores are widely present in layered materials, either as the interlayers or as inter-particle space. Nanopore confinement can significantly modify chemical reactions in those materials. This effect may cause the preferential enrichment of radionuclides in nanopores and therefore directly impact the mobility of the radionuclides. This effect also implies that conventional sorption measurements using disaggregated samples may not represent chemical conditions in actual systems. The control of material structures on ion exchange, surface complexation, and diffusion in layered materials will be systematically examined, and the related modeling approaches will be discussed. This work was performed at Sandia National Laboratories, which is a multiprogram laboratory operated by Sandia Corporation, a Lockheed-Martin Company, for the DOE under contract DE-AC04-94AL8500.

The impacts of pore-scale physical and chemical heterogeneities on the transport of radionuclide-carrying colloids

DOE Office of Scientific and Technical Information (OSTI.GOV)

Wu, Ning

Independent of the methods of nuclear waste disposal, the degradation of packaging materials could lead to mobilization and transport of radionuclides into the geosphere. This process can be significantly accelerated due to the association of radionuclides with the backfill materials or mobile colloids in groundwater. The transport of these colloids is complicated by the inherent coupling of physical and chemical heterogeneities (e.g., pore space geometry, grain size, charge heterogeneity, and surface hydrophobicity) in natural porous media that can exist on the length scale of a few grains. In addition, natural colloids themselves are often heterogeneous in their surface properties (e.g.,more » clay platelets possess opposite charges on the surface and along the rim). Both physical and chemical heterogeneities influence the transport and retention of radionuclides under various groundwater conditions. However, the precise mechanisms how these coupled heterogeneities influence colloidal transport are largely elusive. This knowledge gap is a major source of uncertainty in developing accurate models to represent the transport process and to predict distribution of radionuclides in the geosphere.« less

Radionuclide transfer to fruit in the IAEA TRS No. 472

NASA Astrophysics Data System (ADS)

Carini, F.; Pellizzoni, M.; Giosuè, S.

2012-04-01

This paper describes the approach taken to present the information on fruits in the IAEA report TRS No. 472, supported by the IAEA-TECDOC-1616, which describes the key transfer processes, concepts and conceptual models regarded as important for dose assessment, as well as relevant parameters for modelling radionuclide transfer in fruits. Information relate to fruit plants grown in agricultural ecosystems of temperate regions. The relative significance of each pathway after release of radionuclides depends upon the radionuclide, the kind of crop, the stage of plant development and the season at time of deposition. Fruit intended as a component of the human diet is borne by plants that are heterogeneous in habits, and morphological and physiological traits. Information on radionuclides in fruit systems has therefore been rationalised by characterising plants in three groups: woody trees, shrubs, and herbaceous plants. Parameter values have been collected from open literature, conference proceedings, institutional reports, books and international databases. Data on root uptake are reported as transfer factor values related to fresh weight, being consumption data for fruits usually given in fresh weight.

Workshop on development of radionuclide getters for the Yucca Mountain waste repository: proceedings.

DOE Office of Scientific and Technical Information (OSTI.GOV)

Moore, Robert Charles; Lukens, Wayne W.

The proposed Yucca Mountain repository, located in southern Nevada, is to be the first facility for permanent disposal of spent reactor fuel and high-level radioactive waste in the United States. Total Systems Performance Assessment (TSPA) analysis has indicated that among the major radionuclides contributing to dose are technetium, iodine, and neptunium, all of which are highly mobile in the environment. Containment of these radionuclides within the repository is a priority for the Yucca Mountain Project (YMP). These proceedings review current research and technology efforts for sequestration of the radionuclides with a focus on technetium, iodine, and neptunium. This workshop alsomore » covered issues concerning the Yucca Mountain environment and getter characteristics required for potential placement into the repository.« less

Apparatus for real-time airborne particulate radionuclide collection and analysis

DOEpatents

Smart, John E.; Perkins, Richard W.

2001-01-01

An improved apparatus for collecting and analyzing an airborne particulate radionuclide having a filter mounted in a housing, the housing having an air inlet upstream of the filter and an air outlet downstream of the filter, wherein an air stream flows therethrough. The air inlet receives the air stream, the filter collects the airborne particulate radionuclide and permits a filtered air stream to pass through the air outlet. The improvement which permits real time counting is a gamma detecting germanium diode mounted downstream of the filter in the filtered air stream. The gamma detecting germanium diode is spaced apart from a downstream side of the filter a minimum distance for a substantially maximum counting detection while permitting substantially free air flow through the filter and uniform particulate radionuclide deposition on the filter.

Organ doses from radionuclides on the ground. Part I. Simple time dependences

DOE Office of Scientific and Technical Information (OSTI.GOV)

Jacob, P.; Paretzke, H.G.; Rosenbaum, H.

1988-06-01

Organ dose equivalents of mathematical, anthropomorphical phantoms ADAM and EVA for photon exposures from plane sources on the ground have been calculated by Monte Carlo photon transport codes and tabulated in this article. The calculation takes into account the air-ground interface and a typical surface roughness, the energy and angular dependence of the photon fluence impinging on the phantom and the time dependence of the contributions from daughter nuclides. Results are up to 35% higher than data reported in the literature for important radionuclides. This manuscript deals with radionuclides, for which the time dependence of dose equivalent rates and dosemore » equivalents may be approximated by a simple exponential. A companion manuscript treats radionuclides with non-trivial time dependences.« less

Selected natural and fallout radionuclides in plant foods around the Kudankulam Nuclear Power Project, India.

PubMed

Ross, E Mahiban; Raj, Y Lenin; Wesley, S Godwin; Rajan, M P

2013-01-01

The activity concentrations of certain radionuclides were quantified in some plant foods cultivated around Kudankulam, where a mega-nuclear power plant is being established. The activity concentrations were found more in the 'pulses' group and were the lowest in 'other vegetable' category. The annual effective dose was computed based on the activity concentration of radionuclides and it was found to be higher due to the consumption of cereals and pulses. Other vegetables, cereals, pulses and nuts recorded high transfer factors for the radionuclide (228)Ra. Fruits, leafy vegetables, tubers and roots, and palm embryo registered high transfer factors for (226)Ra. Group-wise activity concentration, radiation dose to the public and soil-plant-to-transfer factor are discussed in detail. Copyright © 2012 Elsevier Ltd. All rights reserved.

Box model of radionuclide dispersion and radiation risk estimation for population in case of radioactivity release from nuclear submarine {number_sign}601 dumped in the Kara Sea

DOE Office of Scientific and Technical Information (OSTI.GOV)

Yefimov, E.I.; Pankratov, D.V.; Ignatiev, S.V.

1997-12-31

When ships with nuclear reactors or nuclear materials aboard suffer shipwreck or in the case of burial or dumping of radioactive wastes, atmospheric fallout, etc., radionuclides may be released and spread in the sea, contaminating the sea water and the sea bottom. When a nuclear submarine (NS) is dumped this spread of activity may occur due to gradual core destruction by corrosion over many years. The objective of this paper is to develop a mathematical model of radionuclide dispersion and to assess the population dose and radiation risk for radionuclide release from the NS No. 601, with Pb-Bi coolant thatmore » was dumped in the Kara Sea.« less