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Sample records for u-series radioactive disequilibria

  1. Mantle Melting Processes Beneath Iceland, Assessment from U-series Disequilibria: Implication for Mantle Plume Dynamics

    NASA Astrophysics Data System (ADS)

    Akalu, T. C.; Kobayashi, K.; Yokoyama, T.; Nakamura, E.

    2008-12-01

    The existence of mantle plumes has recently been questioned on the basis of geophysical, petrological and geochemical arguments (e.g., Meibom, et al., 2003), although there is a long-standing concession that hotspot volcanoes such as Hawaii or Iceland represent the surface expression of mantle plumes which is hot, buoyant upwelling regions beneath the Earth's lithosphere. In addition to that, the physical structures of plumes are still a subject of questions. For instance, there are models which advocate a relatively cool and broad plume beneath Iceland (Ribe, et al, 1995; Ito, et al., 1996), while others proposed hot and narrow plume beneath central Iceland (Mckenzie, 1984; White, et al., 1995; Wolf et al., 1997). Recently, it has been shown that U-series disequilibria in young hotspot lavas (e.g. Sims, et al., 1999; Kokfelt, et al., 2003; Bourdon, et al., 2005) provide a relative measure of mantle upwelling velocity beneath ocean islands. U and Th fractionation produced during melting is a function of the melting rate. In turn, this parameter should scale with mantle upwelling velocities. Simply stated, a larger melting rate (larger mantle upwelling velocity) yields smaller Th excess relative to the parent nuclide. Using our new data together with previous works we modeled U-series disequilibria measured in recent lavas of Iceland volcanoes. For a reasonable range of mantle porosities (0.01-0.5 %) in a dynamic melting model the upwelling rates show sharp radial increase from 3 to12 cm per year towards the presumed center of Iceland plume (i.e., from Krafla and Eldija to Hekla, Örfæjökull, Tunguhran and Askja), but after about 135 km from the center of the plume the upwelling rates remain constant (2-3 cm per year) in Heimaey, Reykjanes Peninsula and Snæfelsness Peninsula as away from the plume center. We suggest that the incremental upwelling rates towards the center must indeed associated with hot and buoyant upwelling that characterized by higher excess temperature than the surrounding mantle. Our observation is consistent with Wolf et al. (1997) seismic study that shows about 150 km radius of the low velocity anomaly beneath central Iceland, and it gives a strong supporting evidence for models of hot and narrow plume beneath central Iceland. Thus, geochemical data (U series disequilibrium) provide important complementary information that is not available from geophysical and petrological data alone in constraining the physical structure of mantle plumes.

  2. Evaluation of Mantle Upwelling Beneath Iceland from U-series Disequilibria: Implication for Icelandic Mantle Plume Dynamics

    NASA Astrophysics Data System (ADS)

    Chekol, T. A.; Kobayashi, K.; Nakamura, E.

    2009-05-01

    The existence of mantle plumes has recently been questioned on the basis of geophysical, petrological and geochemical arguments (e.g., Meibom, et al., 2003), although there is a long-standing concession that hotspot volcanoes such as Hawaii or Iceland represent the surface expression of mantle plumes which is hot, buoyant upwelling regions beneath the Earth's lithosphere. In addition to that, the physical structures of plumes are still a subject of questions. For instance, there are models which advocate a relatively cool and broad plume beneath Iceland (Ribe, et al, 1995; Ito, et al., 1996), while others proposed hot and narrow plume beneath central Iceland (Mckenzie, 1984; White, et al., 1995; Wolf et al., 1997). Recently, it has been shown that U- series disequilibria in young hotspot lavas provide a relative measure of mantle upwelling velocity beneath ocean islands(e.g. Sims, et al., 1999; Kokfelt, et al., 2003; Bourdon, et al., 2005). U and Th fractionation produced during melting is a function of the melting rate. In turn, this parameter should scale with mantle upwelling velocities. Simply stated, a larger melting rate (larger mantle upwelling velocity) yields smaller Th excess relative to the parent nuclide. Using our new data together with previous works we modeled U-series disequilibria measured in recent lavas of Iceland volcanoes. For a reasonable range of mantle porosities (0.01-0.5 %) in a dynamic melting model the upwelling rates show sharp radial increase from 3 to 12 cm per year towards the presumed center of Iceland plume, but after about 135 km from the center of the plume the upwelling rates remain constant (2-3 cm per year). We suggest that the incremental upwelling rates towards the center can be associated with hot and buoyant upwelling that characterized by higher excess temperature than the surrounding mantle. Our observation is consistent with Wolf et al. (1997) seismic study that shows about 150 km radius of the low velocity anomaly beneath central Iceland, and it gives a strong supporting evidence for models of hot and narrow plume beneath central Iceland. Thus, geochemical data (U series disequilibrium) provide important complementary information that is not available from geophysical and petrological data alone in constraining the physical structure of mantle plumes.

  3. CHARACTERIZATION OF CONTAMINANT TRANSPORT USING NATURALLY-OCCURRING U-SERIES DISEQUILIBRIA

    EPA Science Inventory

    The interactions of mixed wastes containing radionuclides with solid rock surface and the mobility of the radionuclides in aquifer systems depend not only on the chemistry of the nuclides and the physico-chemical effects of radioactive decay, but also on the site-specific hydroge...

  4. Are U-Series Disequilibria Transparent to Crustal Processing of Magma? A Case Study at Bezymianny and Klyuchevskoy Volcanoes, Kamchatka, Russia

    NASA Astrophysics Data System (ADS)

    Kayzar, T. M.; Nelson, B. K.; Bachmann, O.; Portnyagin, M.; Ponomareva, V.

    2010-12-01

    Disequilibria in the short-lived uranium-series isotopic system can provide timescales of magma production, modification and transport in all tectonic settings. In volcanic arcs, the field has converged on the concept that (238U/230Th) and (226Ra/230Th) activities greater than one are a result of fluid fluxing from the slab to mantle wedge, and that the preservation of (226Ra/230Th) disequilibria requires rapid transport of melts from the mantle wedge to the surface (226Ra returns to equilibrium with 230Th in ~8000 years). The need for rapid transport coupled with the incompatibility of U-series elements suggest that U-series fractionation is not measurably affected by crustal processes. However, some well-studied arc systems, including the very productive Central Kamchatka Depression (CKD) of the Kamchatkan volcanic arc, show U-series data that are in conflict with this commonly accepted model. Our study focuses on two neighboring volcanic systems, Bezymianny and Klyuchevskoy volcanoes in the CKD. Separated by ~10km, these two systems are thought to share the same mantle source. Klyuchevskoy has primitive compositions (51-56 wt%) while Bezymianny erupts more differentiated andesites (57-63 wt% SiO2); therefore, by examining the U-series signals in these two systems it is possible to decouple a primary signal from one having undergone crustal processing. We record whole rock (238U/230Th) values for Bezymianny ranging from 0.94 to 0.96 in modern eruptive products, while (226Ra/230Th) are >1. We also observe a similar signal in older (212-6791BP) tephra deposits from Klyuchevskoy, measuring (238U/230Th) of 0.92-0.99 (unpublished data, collaborative research with the KALMAR project). (238U/230Th) <1 in arcs have mostly been reported from areas of thick continental crust (Andes; Sigmarsson et al. 1998, Garrison et al. 2006, Jicha et al. 2007) or from an arc where phases such as garnet and/or Al-rich clinopyroxene can retain a high U/Th in the crystalline residue (Jicha et al. 2009). Bezymianny and Klyuchevskoy have low Sr/Y (15.5-19.9), which precludes a significant influence of garnet in generating the observed Th-excess in the CKD. We investigate the possibility of shallow crustal processes such as fractional crystallization, and/or assimilation of local bulk rock or partial melts to fractionate U, Th, and Ra from one another. In particular, we focus on minor mineral phases, such as apatite and magnetite, which are present during early stages of differentiation (andesites) and may fractionate U from Th. We measure U and Th content in these phases in-situ by LA-ICP-MS to obtain average mineral-melt partitioning for each sample with U-series data. Using such average partition coefficients allows us to take into account variations in parameters such as temperature, pressure, and oxygen fugacity that may vary from sample to sample. This mineral trace element data is supported by bulk rock geochemistry and Pb isotope data to evaluate the effects of crustal processing on the U-series system during magma transport and storage.

  5. Characterization of Contaminant Transport using Naturally-Occurring U-Series Disequilibria - Final Report - 05/01/1997 - 04/30/2001

    SciTech Connect

    Murrell, Michael T.; Ku, Teh-Lung

    2001-04-30

    The interactions of mixed wastes containing radionuclides with solid rock surface and the mobility of the radionuclides in aquifer systems depend not only on the chemistry of the nuclides and the physico-chemical effects of radioactive decay, but also on the site-specific hydrogeology. Thus, to characterize contaminant transport, it is best to cross-check figures derived from any small-scale laboratory experiments over limited times with that obtained from field-oriented, natural analog studies. We propose such a study using the naturally-occurring U and Th decay-series disequilibria. The work of ours and other researchers have shown that the parent/daughter disequilibrium patterns existing in groundwater systems can be modeled in terms of local nuclide mass balance to arrive at such information as the rock-water contact time (fluid flow) and rates of contaminant transport, taking into account the retardation effect due to nuclide/rock interaction contaminants at INEL by grouping them into three categories, represented by isotopes of (1) Th and Pa, (2) U and (3) Ra. Mass spectrometric measurements of these elements will be emphasized in order to minimize sample size requirements and to maximize precision. Results will form the data base for a model code for computing: (1) Fluid residence time (transport rates) in the basalt aquifers at various locations, (2) The in-situ adsorption and desorption rate constants, as well as the retardation factors, of various radionuclide wastes, and (3) Rock dissolution rate and its relation to preferential flow and contamination transport in the fractured rock.

  6. Radioactive disequilibria in mineralised fracture samples from two uranium occurrences in northern Sweden

    USGS Publications Warehouse

    Smellie, John A.T.; Rosholt, J.N.

    1984-01-01

    Mineralised fractures from two uranium occurrences in northern Sweden were examined mineralogically and isotopically to establish the presence or absence of radioactive equilibrium that may indicate recent rock-water interaction processes based on the natural mobility of uranium (i.e.; during the last 0.5 Ma). The results show evidence of radioactive disequilibrium in six of the nine samples investigated. Disequilibria are attributable to solution to solid 234U recoil gain (weakly mineralised zones adjacent to the main mineralisation) and solid to solution 234U recoil loss (moderate to highly mineralised zones). The absence of significant 238U loss in the samples emphasises the reducing conditions at the sampled depths. ?? 1984.

  7. Characterization of calculation of in-situ retardation factors of contaminant transport using naturally-radionuclides and rock/water interaction occurring U-Series disequilibria timescales. 1997 annual progress report

    SciTech Connect

    Roback, R.; Murrel, M.; Goldstein, S.; Ku, T.L.; Luo, S.

    1997-01-01

    'The research is directed toward a quantitative assessment of contaminant transport rates in fracture-rock systems using uranium-series radionuclides. Naturally occurring uranium-and thorium-series radioactive disequilibria will provide information on the rates of adsorption-desorption and transport of radioactive contaminants as well as on fluid transport and rock dissolution in a natural setting. This study will also provide an improved characterization of preferential flow and contaminant transport at the Idaho Environmental and Engineering Lab. (INEEL) site. To a lesser extent, the study will include rocks in the unsaturated zone. The authors will produce a realistic model of radionuclide migration under unsaturated and saturated field conditions at the INEEL site, taking into account the retardation processes involved in the rock/water interaction. The major tasks are to (1) determine the natural distribution of U, Th, Pa and Ra isotopes in rock minerals. sorbed phases on the rocks, and in fluids from both saturated and unsaturated zones at the site, and (2) study rock/water interaction processes using U/Th series disequilibrium and a statistical analysis-based model for the Geologic heterogeneity plays an important role in transporting contaminants in fractured rocks. Preferential flow paths in the fractured rocks act as a major pathway for transport of radioactive contaminants in groundwaters. The weathering/dissolution of rock by groundwater also influences contaminant mobility. Thus, it is important to understand the hydrogeologic features of the site and their impact on the migration of radioactive contaminants. In this regard, quantification of the rock weathering/dissolution rate and fluid residence time from the observed decay-series disequilibria will be valuable. By mapping the spatial distribution of the residence time of groundwater in fractured rocks, the subsurface preferential flow paths (with high rock permeability and short fluid residence time) can be determined.'

  8. Use of U-series nuclides to constrain sediments transfer-times in the alluvial plains: example of the Ganges and Bramaputra river system.

    NASA Astrophysics Data System (ADS)

    Chabaux, François; Granet, Mathieu; Blaes, Estelle; Stille, Peter; France-Lanord, Christian; Dosseto, Antony

    2010-05-01

    U-series nuclides have the potential to bring important information on the transfer time of sediments in the alluvial plains. This is a consequence of the dual property of these nuclides 1) to be fractionated during physical denudation and chemical weathering processes and 2) to have radioactive decay periods of the same order of magnitude as the time-scales of these processes (e.g. Chabaux et al., 2003b, 2008). We have illustrated such a potential with the analysis of U-series disequilibria in sediments collected in the Ganges and Bramaputra river basin. The approach relies on the analysis of U-series in river sediments collected along the streams. Indeed, as illustrated in Granet et al. (2007), in large alluvial plains where sediments are only transferred and not affected by additional inputs of new weathering products from fresh rocks, the intensity of 238U-234U-230Th disequilibria in river sediments will only depend on two parameters: (a) the duration of the transfer including the time spent in soils and in the river, and (b) the nature and the intensity of U-Th fractionations occurring in sediments during their transfer into alluvial plains. Recovering time information from the variation of U-Th disequilibria in such sediments requires therefore the use of realistic models accounting for the U-Th fractionation of sediments during their transfers into the plain. From the data, it is proposed for the Ganges and Bramaputra river sediments, that the main U-Th fractionation process is connected with the sediment weathering during their transit and storage in the plain. In this case the U-Th variation in sediments along the two main rivers lead to quite long sediment transfer time in the alluvial plains, of 100-150 ky for Bramaputra plain and of 400 or 500 ky for the Ganges river. Chabaux F., Riotte J., Dequincey O. (2003) U-Th-Ra fractionation during weathering and river transport, Rev Mineral. Geochem. 52, 533-576. Chabaux, F., Bourdon, B., Riotte, J., 2008. U-series Geochemistry in weathering profiles, river waters and lakes. In : S. Krishnaswami and J.K. Cochran (Eds.), U/Th Series Radionuclides in Aquatic Systems, Elsevier, Radioactivity in the Environment, 13, 49-104 M. Granet, F. Chabaux, C. France-Lanord, P. Stille, E. Pelt (2007). Time-scales of sedimentary transfer and weathering processes from U-series nuclides: Clues from the Himalayan rivers, Earth and Planetary Science Letters, 261, 389-406.

  9. Characterization of U-series disequilibria at the Pena Blanca natural analogue site, Chihuahua, Mexico

    SciTech Connect

    Wong, V.; Goodell, P.C.; Anthony, E.Y.

    1999-07-01

    The purpose of this study was to evaluate radionuclide migration from a uranium-mineralized breccia pipe. The site provides an excellent opportunity to evaluate radionuclide mobility in a geochemical environment similar to that around the proposed high-level waste repository at Yucca Mountain, Nevada. Samples represent fracture-infillings from both within and outside the breccia pipe. Mineral assemblages within the fractures include (1) pure kaolinite, (2) a mixture of iron-oxyhydroxides (goethite and hematite) with associated alunite and jarosite, which the authors refer to as the Fe-mineral assemblage, and (3) carbonates. Uranophane, weeksite, soddyite, and boltwoodite are associated with samples from within the breccia zone. The authors obtain radionuclide activities from gamma-ray rather than alpha spectroscopy, and the methodology for these measurements is presented in detail. Plots of {sup 230}Th/{sup 238}U vs. {sup 226}Ra/{sup 230}Th show three distinct mobility trends. (1) The majority of the Fe-mineral samples from within the breccia pipe yield values between 1.0 and 1.1 for both ratios, (2) Fe-mineral samples from outside the ore zone and a kaolinite from within the ore zone have {sup 230}Th/{sup 238}U of 0.58 to 0.83 and {sup 226}Ra/{sup 230}Th of 1.09 to 1.42, and (3) some Fe-mineral samples from within the breccia pipe have values of 1.2 and 0.9 respectively. These data, combined with those from other studies at Pena Blanca suggest that U and Ra are sometimes mobile in the near-surface environment and that multiple episodes of enrichment and leaching are required to explain the trends.

  10. Timescales of magma degassing - Insights from U-series disequilibria, Mount Cameroon, West Africa

    NASA Astrophysics Data System (ADS)

    Turner, M. B.; Reagan, M. K.; Turner, S. P.; Sparks, R. S. J.; Handley, H. K.; Girard, G.; Suh, C. E.

    2013-07-01

    Short-lived uranium-series isotope data from rocks erupted under explosive and effusive regimes are presented and used to provide constraints on the timescales of magmatic degassing and volatile fluxing during the 1999 and 2000 AD eruption of Mt. Cameroon. In contrast to the relatively homogenous major and trace element data of the analysed rocks, volcanic rocks from Mt. Cameroon reveal a spread of 230Th-226Ra isotope data. Volcanic rocks erupted along the southwest rift in 1999 have (226Ra/230Th) ratios of ~ 1.25, whereas rocks erupted more axially in 2000 have relatively low (226Ra/230Th) ratios of 1.09-1.2 and concomitant low Ba/Th ratios. These differences imply separate magma chamber systems and probably reflect differences in the concentrations of water within the primary magmas, which led to different amounts of amphibole fractionation at depth. Variations in the (210Pb/226Ra)0 ratios are used to track degassing or volatile accumulation within the magma system. The near equilibrium (210Pb/226Ra) values for effusively erupted rocks from Mt. Cameroon suggest that this magma resided for more than several decades and less than a few thousand years before it erupted. The small excesses of 210Pb over 226Ra in some samples indicate that some of this magma was fluxed by a Rn-bearing gaseous phase for weeks to years before the eruption. In contrast, most explosively erupted rocks from Mt. Cameroon have deficits of 210Pb relative to 226Ra that require years to decades of degassing before eruption. We suggest that the magmas erupted as scoria at Mt. Cameroon degassed as they rose from lithospheric depths. Deep degassing was CO2-dominated, whereas shallower magma degassing involved more water and crystallisation of an anhydrous mineral assemblage.

  11. 210Pb-226Ra disequilibria in Icelandic basalts and implications for melt transport time

    NASA Astrophysics Data System (ADS)

    Sigmarsson, O.

    2003-04-01

    Primitive basalts with radioactive disequilibrium between isotopes of the 238U decay chain may provide constraints on the timescales of mantle melt migration. The disequilibria between 238U, 230Th and 226Ra have been studied in several Recent basalts whereas very few results exist on the 210Pb-226Ra disequilibria. Only basalts significantly younger than 100 years old can be studied for 210Pb-226Ra disequilibria due to the short half-live of 210Pb (22.3 years). Most lavas measured so far show either 210Pb-226Ra equilibria or 210Pb-deficit which have been attributed to the degassing of 222Rn in shallow magma chambers. Icelandic tholeiites from the last century are in radioactive equilibrium with (210Pb/226Ra) equal to unity. These basalts are fed from shallow magma chambers having residence time exceeding 100 years. In contrast, primitive alkaline basalts (MgO =7-12%) from Surtsey island had (210Pb/226Ra) ranging from 0.45±0.04 to 0.82±0.06 at the time of eruption. These large 210Pb deficits are unlikely to result from shallow magma degassing since no magma chamber existed beneath this volcanic island which was born during the 1963-67 eruption. The 210Pb-226Ra disequilibria increase from the beginning towards the end of the eruption when the most primitive basalts were produced, and decreases systematically with increasing Th content. These same basalts show a negative correlation between Pb and Cu abundances which are inconsistent with exsolution of sulfur rich liquid or crystallisation of sulphides as a fractionation mechanism of 210Pb and 226Ra. The large deficit of 210Pb in Surtsey lavas were thus most likely generated during mantle partial melting. In such a case, the time of melt transport from the source region to surface is constrained to be significantly shorter than 100 years.

  12. Minimum speed limit for ocean ridge magmatism from 210Pb-226Ra-230Th disequilibria.

    PubMed

    Rubin, K H; van der Zander, I; Smith, M C; Bergmanis, E C

    2005-09-22

    Although 70 per cent of global crustal magmatism occurs at mid-ocean ridges-where the heat budget controls crustal structure, hydrothermal activity and a vibrant biosphere-the tempo of magmatic inputs in these regions remains poorly understood. Such timescales can be assessed, however, with natural radioactive-decay-chain nuclides, because chemical disruption to secular equilibrium systems initiates parent-daughter disequilibria, which re-equilibrate by the shorter half-life in a pair. Here we use 210Pb-226Ra-230Th radioactive disequilibria and other geochemical attributes in oceanic basalts less than 20 years old to infer that melts of the Earth's mantle can be transported, accumulated and erupted in a few decades. This implies that magmatic conditions can fluctuate rapidly at ridge volcanoes. 210Pb deficits of up to 15 per cent relative to 226Ra occur in normal mid-ocean ridge basalts, with the largest deficits in the most magnesium-rich lavas. The 22-year half-life of 210Pb requires very recent fractionation of these two uranium-series nuclides. Relationships between 210Pb-deficits, (226Ra/230Th) activity ratios and compatible trace-element ratios preclude crustal-magma differentiation or daughter-isotope degassing as the main causes for the signal. A mantle-melting model can simulate observed disequilibria but preservation requires a subsequent mechanism to transport melt rapidly. The likelihood of magmatic disequilibria occurring before melt enters shallow crustal magma bodies also limits differentiation and heat replenishment timescales to decades at the localities studied. PMID:16177787

  13. The U-series comminution approach: where to from here

    NASA Astrophysics Data System (ADS)

    Handley, Heather; Turner, Simon; Afonso, Juan; Turner, Michael; Hesse, Paul

    2015-04-01

    Quantifying the rates of landscape evolution in response to climate change is inhibited by the difficulty of dating the formation of continental detrital sediments. The 'comminution age' dating model of DePaolo et al. (2006) hypothesises that the measured disequilibria between U-series nuclides (234U and 238U) in fine-grained continental (detrital) sediments can be used to calculate the time elapsed since mechanical weathering of a grain to the threshold size ( 50 µm). The comminution age includes the time that a particle has been mobilised in transport, held in temporary storage (e.g., soils and floodplains) and the time elapsed since final deposition to present day. Therefore, if the deposition age of sediment can be constrained independently, for example via optically stimulated luminescence (OSL) dating, the residence time of sediment (e.g., a palaeochannel deposit) can be determined. Despite the significant potential of this approach, there is still much work to be done before meaningful absolute comminution ages can be obtained. The calculated recoil loss factor and comminution age are highly dependent on the method of recoil loss factor determination used and the inherent assumptions. We present new and recently published uranium isotope data for aeolian sediment deposits, leached and unleached palaeochannel sediments and bedrock samples from Australia to exemplify areas of current uncertainty in the comminution age approach. In addition to the information gained from natural samples, Monte Carlo simulations have been conducted for a synthetic sediment sample to determine the individual and combined comminution age uncertainties associated to each input variable. Using a reasonable associated uncertainty for each input factor and including variations in the source rock and measured (234U/238U) ratios, the total combined uncertainty on comminution age in our simulation (for two methods of recoil loss factor estimation: weighted geometric and surface area measurement with an incorporated fractal correction) can amount to ± 220-280 ka. The modelling shows that small changes in assumed input values translate into large effects on absolute comminution age. To improve the accuracy of the technique and provide meaningful absolute comminution ages, much tighter constraints are required on the assumptions for input factors such as the fraction of alpha-recoil lost 234Th and the initial (234U/238U) ratio of the source material. In order to be able to directly compare calculated comminution ages produced by different research groups, the standardisation of pre-treatment procedures, recoil loss factor estimation and assumed input parameter values are required. We suggest a set of input parameter values for such a purpose.

  14. Time scale and conditions of weathering under tropical climate: Study of the Amazon basin with U-series

    NASA Astrophysics Data System (ADS)

    Dosseto, A.; Bourdon, B.; Gaillardet, J.; Allègre, C. J.; Filizola, N.

    2006-01-01

    The Rio Solimões/Amazonas (Amazon River) and its major tributaries have been analyzed for U-series nuclides. 238U- 234U- 230Th- 226Ra disequilibria have been measured in the dissolved (<0.2 ?m) and suspended loads (>0.2 ?m) as well as bed sands. U-series disequilibria are closely related to major and trace element compositions and therefore reflect elemental fractionation during chemical weathering. Moreover, while the dissolved load records present-day weathering, suspended particles integrate the erosion history over much longer time scales (>100 ka). Lowland rivers are characterized by long time scales of chemical erosion (?100 ka) resulting in a high weathering intensity. Moreover, exchange between suspended particles and the dissolved load may explain the U-series signature for these rivers. By combining U-series and Pb isotopes in suspended particles, we show that erosion in the Rio Madeira basin occurred as a multi-step process, whereby the pristine continental crust was eroded several hundreds of Ma ago to produce sediments that have then been integrated in the Cordillera by crustal shortening and are currently eroded. In contrast, recent erosion of a pristine crust is more likely for the Rio Solimões/Amazonas (<10 ka). The suspended particles of the rivers draining the Andes (Solimões/Amazonas, Madeira) suggest time scales of weathering ranging between 4 and 20 ka. This indicates that suspended particles transported by those rivers are not stored for long periods in the Andean foreland basin and the tropical plain. The sediments delivered to the ocean have resided only a few ka in the Amazon basin (6.3 ± 1 ka for the Rio Amazonas at Óbidos). Nevertheless, a large fraction of the sediments coming out from the Andes are trapped in the foreland basin and may never reach the ocean. Erosion in the Andes is not operating in steady state. U-series systematics shows unambiguously that rivers are exporting a lot more sediments than predicted by steady-state erosion and that is a consequence of soil destruction greater than production. By relating this observation to the short time scales of weathering inferred for the Andes (a few ka), it appears that the erosion regime has been recently perturbed, resulting in high denudation rates. A possible explanation would be the increase in precipitation less than 5 ka proposed by recent paleoclimatic studies. Our results indicate that erosion responds rapidly to high-frequency climatic fluctuations.

  15. Theoretical studies of {sup 238}U-{sup 230}Th-{sup 226}Ra and {sup 235}U-{sup 231}Pa disequilibria in young lavas produced by mantle melting

    SciTech Connect

    Zou, H.; Zindler, A.

    2000-05-01

    This paper provides ready-to-use equations to describe variations in uranium-series (U-series) disequilibrium as a function of elemental distribution coefficients, melting porosity, melting rate, and melting time. The effects of these melting parameters on U-series disequilibria are quantitatively evaluated in both an absolute and relative sense. The importance of net elemental fractionation and ingrowth of daughter nuclides are also described and compared in terms of their relative contributions to total U-series disequilibrium. In addition, the authors compare the production of U-series disequilibrium during mantle melting to trace element fractionations produced by melting in a similar context. Trace element fractionations depend externally on the degree to which a source is melted, whereas U-series disequilibrium depends upon both the degree and rate of melting. In contrast to previous models, their approach to modeling U-series disequilibrium during dynamic melting collapses simply to a description of trace element behavior during dynamic melting when the appropriate decay terms are omitted. Their formulation shows that extremely small degrees of melting, sometimes called upon to explain observed extents of U-series disequilibrium, are not always required.

  16. Saprolite Formation Rates using U-series Isotopes in a Granodiorite Weathering Profile from Boulder Creek CZO (Colorado, USA)

    NASA Astrophysics Data System (ADS)

    Pelt, Eric; Chabaux, Francois; Mills, T. Joseph; Anderson, Suzanne P.; Foster, Melissa A.

    2015-04-01

    Timescales of weathering profile formation and evolution are important kinetic parameters linked to erosion, climatic, and biological processes within the critical zone. In order to understand the complex kinetics of landscape evolution, water and soil resources, along with climate change, these parameters have to be estimated for many different contexts. The Betasso catchment, within the Boulder Creek Critical Zone Observatory (BC-CZO) in Colorado, is a mountain catchment in Proterozoic granodiorite uplifted in the Laramide Orogeny ca. 50 Ma. In an exposure near the catchment divide, an approximately 1.5 m deep profile through soil and saprolite was sampled and analysed for bulk U-series disequilibria (238U-234U-230Th-226Ra) to estimate the profile weathering rate. The (234U/238U), (230Th/234U) and (226Ra/230Th) disequilibria through the entire profile are small but vary systematically with depth. In the deepest samples, values are close to equilibrium. Above this, values are progressively further from equilibrium with height in the profile, suggesting a continuous leaching of U and Ra compared to Th. The (234U/238U) disequilibria remain < 1 along the profile, suggesting no significant U addition from pore waters. Only the shallowest sample (~20 cm depth) highlights a 226Ra excess, likely resulting from vegetation cycling. In contrast, variations of Th content and (230Th/232Th) - (238U/232Th) activity ratios in the isochron diagram are huge, dividing the profile into distinct zones above and below 80 cm depth. Below 80 cm, the Th content gradually increases upward from 1.5 to 3.5 ppm suggesting a relative accumulation linked to chemical weathering. Above 80 cm, the Th content jumps to ~15 ppm with a similar increase of Th/Ti or Th/Zr ratios that clearly excludes the same process of relative accumulation. This strong shift is also observed in LREE concentrations, such as La, Ce and Nd, and in Sr isotopic composition, which suggests an external input of radiogenic material such as dust from the western Colorado deserts or eroding landscapes. For the deeper part of the profile, the strong upward decrease of the (230Th/232Th) and (238U/232Th) activity ratio without generation of strong disequilibria could suggest a long history (~0.5-1 Ma) of U leaching with a very slow saprolite development (~1 m/Ma). Such a result is in agreement with slow weathering rates deduced from modern solute chemistry of rivers, but would be much lower than 10Be denudation rates on the same profile of ~10-20 m/Ma. As the 10Be rates integrate denudation over a timescale of 40-80 ka, the apparent inconsistency between rates deduced by U-series data and Be data might suggest that erosion rates have increased during the 10Be integrating time.

  17. Determination of sedimentary transfer time from U-series nuclides:implications from the study of the Gandak river sediments

    NASA Astrophysics Data System (ADS)

    Bosia, Clio; Chabaux, Francois; France-Lanord, Christian; Deloule, Etienne; Pelt, Eric

    2014-05-01

    In previous studies, it was proposed to constrain sediments transfer time in alluvial plains by analyzing the variations of the U-series disequilibria in river sediments along the stream. This approach was illustrated in the case of the Ganges-Brahmaputra basin and it allowed defining a sediment transfer scenario that includes significantly different transfer times within the alluvial plain. These studies suggest that the transfer times depend on the sediment grain size: short transfer times for fine-grained sediments (a few ky or less) and much longer ones for coarse-grained sediments (100 ky or more - [1-4]). However, those estimations can be questioned in the light of recent studies based on the analysis of cosmonuclides [5] and Sr et Nd isotopes [6] , that suggest shorter transfer times (respectively 1-2 ky and less for the second study) for coarse-grained sediments in Himalayan streams. In order to better constrain the origin of the U-series disequilibria variations in river sediments, we performed a detailed study of the U-series nuclides in the sediments of the Gandak River, one of the main Ganges tributaries. This study involves the sampling during monsoon period of suspended sediments, collected at different depths of the water column in the downstream and upstream river sections. At the same time, a regular upstream-downstream sampling of riverbank sediments during non-monsoon period was conducted, with sediments collection on both riversides of a same sampling station. U-Th data obtained on whole rock samples outline the occurrence of significant 238U-230Th-226Ra disequilibria in river sediments, with however no simple upstream-downstream variation. The correlations observed between (238U/232Th) activity ratios and Ti/Th ratios as well as between (230Th/238U) ratios and (Nd, Ce, La, Sm)/Th ratios suggest that minor mineral phases, such as Ti-bearing minerals, monazite, zircon or xenotime, are likely to control a significant part of the U-Th-Ra budget in the Gandak sediments. U-isotopes fractionation could therefore not only depend on the chemical evolution of the sediments during its transfer within the plain and on the time evolution, but also on the mechanical transformation of the sediments mineralogical composition. This last aspect can be significantly influenced by local hydraulic conditions, inducing important sorting effects in river sediments. These results illustrate the interest to investigate separated mineral phases of river sediments. Indeed, we need to clarify the role of the mineral composition in the control of U-Th-Ra isotopic fractionation in river sediments. This is a key point to achieve more reliable transfer times, avoiding problems linked to environmental bias. [1] Chabaux et al., 2012, C. R. Geoscience, 344 (11-12): 688-703; [2] Chabaux et al., 2006, J. Geochem. Exploration, 88: 373-375 ; [3] Granet et al., 2010, Geochim. et Cosmoch. Acta, 74 (10): 2851-2865 ; [4] Granet et al., 2007, Earth and Planet. Sci. Lett., 261 (3-4): 389-406 ; [5] Lupker et al., 2012, Earth and Planet. Sci. Lett., 333-334: 146-156; [6] Rahaman et al., 2009, Geology, 37 (6): 559-562.

  18. Methods for obtaining sorption data from uranium-series disequilibria

    SciTech Connect

    Finnegan, D.L.; Bryant, E.A.

    1987-12-01

    Two possible methods have been identified for obtaining in situ retardation factors from measurements of uranium-series disequilibria at Yucca Mountain. The first method would make use of the enhanced {sup 234}U/{sup 238}U ratio in groundwater to derive a signature for exchangeable uranium sorbed on the rock; the exchangeable uranium would be leached and assayed. The second method would use the ratio of {sup 222}Rn to {sup 234}U in solution, corrected for weathering, to infer the retardation factor for uranium. Similar methods could be applied to thorium and radium.

  19. Chemical Disequilibria and Sources of Gibbs Free Energy Inside Enceladus

    NASA Astrophysics Data System (ADS)

    Zolotov, M. Y.

    2010-12-01

    Non-photosynthetic organisms use chemical disequilibria in the environment to gain metabolic energy from enzyme catalyzed oxidation-reduction (redox) reactions. The presence of carbon dioxide, ammonia, formaldehyde, methanol, methane and other hydrocarbons in the eruptive plume of Enceladus [1] implies diverse redox disequilibria in the interior. In the history of the moon, redox disequilibria could have been activated through melting of a volatile-rich ice and following water-rock-organic interactions. Previous and/or present aqueous processes are consistent with the detection of NaCl and Na2CO3/NaHCO3-bearing grains emitted from Enceladus [2]. A low K/Na ratio in the grains [2] and a low upper limit for N2 in the plume [3] indicate low temperature (possibly < 273 K) of aqueous processes. Although many of the energetically favorable redox reactions are sluggish at low temperature, they could be catalyzed by enzymes if organisms were (are) present. The redox conditions in aqueous systems and amounts of available Gibbs free energy should have been affected by the production, consumption and escape of hydrogen. Aqueous oxidation of minerals (Fe-Ni metal, Fe-Ni phosphides, etc.) accreted on Enceladus should have led to H2 production, which is consistent with H2 detection in the plume [1]. Numerical evaluations based on concentrations of plume gases [1] reveal sufficient energy sources available to support metabolically diverse life at a wide range of activities (a) of dissolved H2 (log aH2 from 0 to -10). Formaldehyde, carbon dioxide [c.f. 4], HCN (if it is present), methanol, acetylene and other hydrocarbons have the potential to react with H2 to form methane. Aqueous hydrogenations of acetylene, HCN and formaldehyde to produce methanol are energetically favorable as well. Both favorable hydrogenation and hydration of HCN lead to formation of ammonia. Condensed organic species could also participate in redox reactions. Methane and ammonia are the final products of these putative redox transformations. Sulfates may have not formed in cold and/or short-term aqueous environments with a limited H2 escape. In contrast to Earth, Mars and Europa, the moon may have no (or very limited [4]) potential for sulfate reduction. Despite nutrient (C, N, P and S) and metal (e.g. Fe, Ni) rich environments and multiple sources of Gibbs free energy during aqueous episode(s), putative life on Enceladus [4] would have adapted to survive in low water activity alkaline brines rich in ammonia, methanol and organic liquids at temperature >150-170 K. The comet-like abundances of major plume gases and apparent redox disequilibria in aquatic systems are consistent with a minimal influence of aqueous processes on endogenic chemical reactions and may indicate abiotic interior. Alternatively, plume gases may represent never melted primordial parcels of the icy shell, while the deeper interior could contain altered species transformed in abiotic and/or biological processes. Refs: [1] Waite J. et al. (2009) Nature 460, 487-490. [2] Postberg F. et al. (2009) Nature 459, 1098-1101. [3] Hansen C. et al. (2010) 38th COSPAR Sci. Assembly. [4] McKay C. et al. (2008) Astrobiology 8, 909-919.

  20. The Times Scale of Andesite Differentiation at Arenal Volcano, Costa Rica (1968-2003), Indicated by U-Th-Ra Disequilibria.

    NASA Astrophysics Data System (ADS)

    Tepley, F. J.; Lundstrom, C. C.; Williams, R. W.; Murrell, M. T.; Goldstein, S. J.

    2004-12-01

    Arenal Volcano in Costa Rica has continuously erupted since 1968 evolving in a complex fashion involving crystal fractionation, magma mixing, degassing, and wall-rock interaction (Reagan et al., 1987; Cigolini, 1998). We have measured trace-element concentrations and U-series disequilibria in whole rocks and mineral separates (pyroxene, plagioclase, magnetite) over the course of the eruption from 1968 to 2003 by ICP-MS, TIMS and PIMMS techniques. Whole rock and mineral separate analyses (n>20) show only minor variation in (230Th)/(232Th) (1.10 to 1.18). In contrast, (230Th)/(238U) range from 0.91 to 1.04 reflecting the moderate spread in Th/U. Th/U consistently change from low values in the early samples (2.4) to a constant, higher value from 1986 to present (2.65). The observed U-Th disequilibria are consistent with a time scale of mineral formation being much less than that of 230Th decay (<104 years -they are not old xenocrysts) for all samples in the study. A further implication is that mantle-derived recharge magmas entering the Arenal magma chamber either have changed through time from more U-enriched to less U-enriched, or that assimilation has changed the Th/U of the system but not (230Th)/(232Th) (but the assimilant has to be very young Arenal cumulates or fortuitously have the same (230Th)/(232Th)). Ra isotope data are being analyzed to evaluate whether differentiation and mineral formation in this system operate on a time scale closer to the half life of Ra (1600 years).

  1. Atmospheric dust contribution to budget of U-series nuclides in weathering profiles. The Mount Cameroon volcano

    NASA Astrophysics Data System (ADS)

    Pelt, E.; Chabaux, F. J.; Innocent, C.; Ghaleb, B.

    2009-12-01

    Analysis of U-series nuclides in weathering profiles is developed today for constraining time scale of soil and weathering profile formation (e.g., Chabaux et al., 2008). These studies require the understanding of U-series nuclides sources and fractionation in weathering systems. For most of these studies the impact of aeolian inputs on U-series nuclides in soils is usually neglected. Here, we propose to discuss such an assumption, i.e., to evaluate the impact of dust deposition on U-series nuclides in soils, by working on present and paleo-soils collected on the Mount Cameroon volcano. Recent Sr, Nd, Pb isotopic analyses performed on these samples have indeed documented significant inputs of Saharan dusts in these soils (Dia et al., 2006). We have therefore analyzed 238U-234U-230Th nuclides in the same samples. Comparison of U-Th isotopic data with Sr-Nd-Pb isotopic data indicates a significant impact of the dust input on the U and Th budget of the soils, around 10% for both U and Th. Using Sr-Nd-Pb isotopic data of Saharan dusts given by Dia et al. (2006) we estimate U-Th concentrations and U-Th isotope ratios of dusts compatible with U-Th data obtained on Saharan dusts collected in Barbados (Rydell H.S. and Prospero J.M., 1972). However, the variations of U/Th ratios along the weathering profiles cannot be explained by a simple mixing scenario between material from basalt and from the defined atmospheric dust pool. A secondary uranium migration associated with chemical weathering has affected the weathering profiles. Mass balance calculation suggests that U in soils from Mount Cameroon is affected at the same order of magnitude by both chemical migration and dust accretion. Nevertheless, the Mount Cameroon is a limit case were large dust inputs from continental crust of Sahara contaminate basaltic terrain from Mount Cameroon volcano. Therefore, this study suggests that in other contexts were dust inputs are lower, or the bedrocks more concentrated in U and Th, the dust contribution will not significantly influence U-series dating. Chabaux F., Bourdon B., Riotte J. (2008). U-series Geochemistry in weathering profiles, river waters and lakes. Radioactivity in the Environment, 13, 49-104. Dia A., Chauvel C., Bulourde M. and Gérard M. (2006). Eolian contribution to soils on Mount Cameroon: Isotopic and trace element records. Chem. Geol. 226, 232-252. Rydell H.S. and Prospero J.M. (1972). Uranium and thorium concentrations in wind-borne Saharan dust over the western equatorial north atlantic ocean. EPSL 14, 397-402.

  2. Interrelationships between Amerindian tribes of lower Amazonia as manifest by HLA haplotype disequilibria.

    PubMed Central

    Black, F L

    1984-01-01

    HLA B-C haplotypes exhibit common disequilibria in populations drawn from four continents, indicating that they are subject to broadly active selective forces. However, the A-B and A-C associations we have examined show no consistent disequilibrium pattern, leaving open the possibility that these disequilibria are due to descent from common progenitors. By examining HLA haplotype distributions, I have explored the implications that would follow from the hypothesis that biological selection played no role in determining A-C disequilibria in 10 diverse tribes of the lower Amazon Basin. Certain haplotypes are in strong positive disequilibria across a broad geographic area, suggesting that members of diverse tribes descend from common ancestors. On the basis of the extent of diffusion of the components of these haplotypes, one can estimate that the progenitors lived less than 6,000 years ago. One widely encountered lineage entered the area within the last 1,200 years. When haplotype frequencies are used in genetic distance measurements, they give a pattern of relationships very similar to that obtained by conventional chord measurements based on several genetic markers; but more than that, when individual haplotype disequilibria in the several tribes are compared, multiple origins of a single tribe are discernible and relationships are revealed that correlate more closely to geographic and linguistic patterns than do the genetic distance measurements. PMID:6595946

  3. The Genetics of DROSOPHILA SUBOBSCURA Populations. Xiv. Further Data on Linkage Disequilibria

    PubMed Central

    Loukas, M.; Krimbas, C. B.; Morgan, K.

    1980-01-01

    Data coming from one natural population of D. subobscura, that of Crete, are presented in detail and examined for nonrandom associations of genes and gene arrangements. This population and four others previously studied are reanalyzed for the detection of higher than first-order interactions. Only first-order interactions are important and statistically significant, especially those concerning genes and inversions in which these genes are included. The paucity of linkage disequilibria detected is remarkable, and we argue that it does not depend on the methods of study, rather it is genuine. We further argue that most of the disequilibria detected are probably due to mechanisms based on epistatic selection. PMID:17249049

  4. U-series Dating of Stalagmites from Borneo

    NASA Astrophysics Data System (ADS)

    Adkins, J. F.; Partin, J.; Cobb, K.; Clark, B.

    2006-12-01

    In a series of field campaigns dating back to the fall of 2003 we have collected over 60 stalagmites from the Gunung Buda cave system in Sarawak, Malaysia (4°N, 115°E). At least twenty of these samples have excellent calcite preservation and span an age range from modern to over 500,000 years old. The bulk of the collection is of early glacial to Holocene age and can provide multiple overlapping records of climate variability from the Western Pacific Warm Pool. However, generating absolute U-series ages from this collection is challenging. The host rock is a Miocene aged limestone that is covered by rainforest with virtually no topsoil development. This setting leaves the typical stalagmite sample with a low uranium concentration (100s of ppb), a low initial ?234U (-650‰ to -100‰), and a relatively high detrital Th concentration (10s to 100s of pmol/g). We have generated age models in these difficult circumstances by making over 150 MC-ICP-MS measurements of the 238U-234U-230Th-232Th disequilibrium system. Ages are limited by our correction for initial 230Th. This is a common problem in U-series dating of stalagmites that we have addressed by generating a "histogram" of initial 230/232 values. With 14 isochrons from four separate stalagmites spanning the glacial maximum through the Holocene we can conservatively constrain the initial 230/232 atom ratio to be 60±10x10-6. There are small differences in the weighted mean of this value between stalagmites, but no systematic differences with time within a stalagmite. The very low ?234U values are intriguing and must represent the effects of recent weathering of the host limestone. These low and variable ?234U ratios also make it imperative to calculate the initial 230/232 ratios with full three-dimensional isochrons, extrapolating to zero U-238 on a "Rosholt Diagram" does not produce a consistent answer between the samples. Overall we can produce 2 sigma age errors that are better than 1% for the combined analytical and initial 230Th uncertainties.

  5. Upwelling Rates Beneath Hotspots : Evidence From U-Series in Basalts From the Mid-Atlantic Ridge and the Azores Islands

    NASA Astrophysics Data System (ADS)

    Bourdon, B. P.; Turner, S. P.

    2001-12-01

    In this study, we have analyzed U-series in lavas from the Azores islands and the nearby Mid-Atlantic Ridge (FAZAR cruise) in an attempt to assess the relative importance of melting processes versus source variations in the context of ridge-hotpsot interaction. The lavas were analyzed for 238U-230Th (Turner et al. 1997, Bourdon et al. 1996) 226Ra-230Th and 235U-231Pa disequilibria by thermal ionisation mass spectrometry. Our results for the historic lavas from the Azores islands show that the 231Pa excess are at the low end of the trend found for other OIB (Pickett et al. 1997 and Bourdon et al. 1998) and fall on a positive correlation in a 231Pa/235U versus 230Th/238U diagram. In contrast, lavas from the nearby Mid-Atlantic ridge are characterized by larger (231Pa/235U) activity ratios for similar and greater (230Th/238U) ratios. There is also a weak correlation between 226Ra/230Th and 231Pa/235U. These data do not indicate a simple mixing trend between an N-MORB and an enriched component in the 231Pa/235U versus 230Th/238U diagram since the MORBs which do not have the most radiogenic isotope signatures compared with the Azores island basalts have some of the largest (230Th/238U) and 231Pa/235U. Clearly, the dynamics of melting must have played a role in generating larger 230Th and 231Pa excesses beneath the Mid-Atlantic ridge. We infer that this must be due to the absence of a lithospheric lid as larger excesses of 230Th and 231Pa can be generated for longer melting columns. Thus, ridge-hotspot interaction cannot imply a simple transfer of melt from the hotspot to the ridge. The 230Th/238U and 226Ra/230Th data across the Azores plateau shows a maximum for the island of Terceira and mimics the depth anomaly which is thought to result from the hotspot. This trend is also consistent with observations of rare gases (M. Moreira pers. comm.) and suggests that it must be related to the presence of deep material. The U-series trend is the reverse of the trend found in Hawaii by Sims et al. (2000) which was attributed to variations in upwelling rates across the rising plume. This observation can be rationalized in the context of an equilibrium melt transport model (Spiegelman and Elliott, 1993) where U-series disequilibria are sensitive to upwelling rates. For slow upwelling rates such as below the Azores, larger 230Th excesses are predicted in the center of the plume. This suggests that the upwelling rate beneath the center of the plume must be of the order of a few cm per year which is an order of magnitude lower than values estimated for Hawaii. Turner et al. 1997, Chem. Geol. 139, 145-164. Bourdon et al. 1996, Earth Planet. Sci. Lett. 142, 175-189. Pickett et al. 1997, Earth Planet. Sci. Lett. 148, 259-271. Sims et al. 1999, Geochim. Cosmochim. Acta. 63, 4119-4138. Spiegelman and Elliot, 1993, Earth Planet. Sci. Lett., 118, 1-20.

  6. Oxygen isotope heterogeneity and disequilibria of olivine crystals in large volume Holocene basalts from Iceland: Evidence

    E-print Network

    Bindeman, Ilya N.

    Oxygen isotope heterogeneity and disequilibria of olivine crystals in large volume Holocene basalts glass is relatively homogeneous with respect to oxygen isotopes, plagioclase phenocrysts exhibit crystal ), Nu´pahraun (ca. 4000 BP, >1 km3 ) and Thjo´rsa´rhraun (ca 8000 BP, >20 km3 ). We present oxygen

  7. Evaluation of Pleistocene groundwater flow through fractured tuffs using a U-series disequilibrium approach, Pahute Mesa, Nevada, USA

    USGS Publications Warehouse

    Paces, James B.; Nichols, Paul J.; Neymark, Leonid A.; Rajaram, Harihar

    2013-01-01

    Groundwater flow through fractured felsic tuffs and lavas at the Nevada National Security Site represents the most likely mechanism for transport of radionuclides away from underground nuclear tests at Pahute Mesa. To help evaluate fracture flow and matrix–water exchange, we have determined U-series isotopic compositions on more than 40 drill core samples from 5 boreholes that represent discrete fracture surfaces, breccia zones, and interiors of unfractured core. The U-series approach relies on the disruption of radioactive secular equilibrium between isotopes in the uranium-series decay chain due to preferential mobilization of 234U relative to 238U, and U relative to Th. Samples from discrete fractures were obtained by milling fracture surfaces containing thin secondary mineral coatings of clays, silica, Fe–Mn oxyhydroxides, and zeolite. Intact core interiors and breccia fragments were sampled in bulk. In addition, profiles of rock matrix extending 15 to 44 mm away from several fractures that show evidence of recent flow were analyzed to investigate the extent of fracture/matrix water exchange. Samples of rock matrix have 234U/238U and 230Th/238U activity ratios (AR) closest to radioactive secular equilibrium indicating only small amounts of groundwater penetrated unfractured matrix. Greater U mobility was observed in welded-tuff matrix with elevated porosity and in zeolitized bedded tuff. Samples of brecciated core were also in secular equilibrium implying a lack of long-range hydraulic connectivity in these cases. Samples of discrete fracture surfaces typically, but not always, were in radioactive disequilibrium. Many fractures had isotopic compositions plotting near the 230Th-234U 1:1 line indicating a steady-state balance between U input and removal along with radioactive decay. Numerical simulations of U-series isotope evolution indicate that 0.5 to 1 million years are required to reach steady-state compositions. Once attained, disequilibrium 234U/238U and 230Th/238U AR values can be maintained indefinitely as long as hydrological and geochemical processes remain stable. Therefore, many Pahute Mesa fractures represent stable hydrologic pathways over million-year timescales. A smaller number of samples have non-steady-state compositions indicating transient conditions in the last several hundred thousand years. In these cases, U mobility is dominated by overall gains rather than losses of U.

  8. Impact of the 235U series on doses from intakes of natural uranium and decay progeny.

    PubMed

    Lowe, L M

    1997-10-01

    The doses from 235U series radionuclides have often been ignored in dose assessments involving natural uranium and progeny. This is due to the relatively low abundance of 235U in natural uranium (less than 5% on an activity basis). However, inclusion of the 235U series radionuclides, especially 227Ac and 231Pa, in dose calculations can have a substantial impact on estimated inhalation doses. PMID:9314233

  9. Disequilibrium of the 238U series in basalt

    USGS Publications Warehouse

    Somayajulu, B.L.K.; Tatsumoto, M.; Rosholt, J.N.; Knight, R.J.

    1966-01-01

    Radioisotope analyses of basalt samples from Hawaii, Japan, and Iwo Jima show that: (1) 234U and 238U are virtually in radioactive equilibrium, (2) 230Th exceeds equilibrium values in all these samples, (3) 210Pb concentrations range from 10-200% of the equilibrium values and average 30% deficient, and (4) 226Ra is probably not in equilibrium with 234U. The source regions of the basalts or magma forming processes are open systems, chemically. The enrichment of some of the uranium-daughter nuclides is insufficient to account for the excess 206Pb in volcanic rocks. The isotopic composition of lead and specific activity of 210Pb in sublimates from Showa-shinzan, Japan are also reported. ?? 1966.

  10. Constraining the timescales of sediment transport in lowland regions using U-series isotopes and morphometric analysis

    NASA Astrophysics Data System (ADS)

    Martin, Ashley; Dosseto, Anthony; Chivas, Allan; May, Jan-Hendrik

    2014-05-01

    The uranium-series (U-series) isotopes are fractionated by chemical and physical weathering, and undergo radioactive decay on timescales relevant to Earth-surface processes (103-106 a). The comminution age technique is based on the disequilibrium between 234U and 238U due to the effects of alpha-decay in fine-grained (< 63 µm) sediment [1]. The calculated comminution age represents the sediment residence time i.e. the time elapsed since a sediment grain was formed by weathering from bedrock, until its eventual deposition. When applied to fluvial systems, this integrates storage in the weathering profile, transit time in the catchment and any temporary storage in alluvial deposits. Despite the majority of global sediment flux to the oceans being derived from slowly eroding lowland regions, still little is known with regard to the dominant controls of erosion in these areas [2]. Here we apply the comminution age technique to the six major catchments in the Gulf of Carpentaria basin (GOC) in northern Australia to investigate the temporal dynamics of erosion in lowland regions. In addition, the geomorphometric properties of the catchments were measured using Geographic Information System techniques (GIS) in order to disentangle topographic vs. climatic controls on the sediment residence time. The sediment residence times calculated from U-series isotopes do not increase linearly downstream which reflects the complicated nature of sediment transport in lowland regions. The sediment residence time appears to be broadly correlated with mean annual precipitation but this relationship is less clear following consideration of the geomorphometric properties of each sub-catchment. This highlights the tendency of geochronological approaches to oversimplify the mechanisms of sediment transport in fluvial systems. Understanding what controls the temporal dynamics of erosion in fluvial system on millennial timescales requires the combination of the hitherto commonly separate approaches of geochronology and geomorphometrics. [1] DePaolo et al. (2006), Earth and Planetary Science Letters, 248, 394-410. [2] Willenbring et al. (2013), Geology 41, 343.

  11. Thermal ionization mass spectrometry U-series dating of a hominid site near Nanjing, China

    NASA Astrophysics Data System (ADS)

    Zhao, Jian-Xin; Hu, Kai; Collerson, Kenneth D.; Xu, Han-Kui

    2001-01-01

    Mass spectrometric U-series dating of speleothems from Tangshan Cave, combined with ecological and paleoclimatic evidence, indicates that Nanjing Man, a typical Homo erectus morphologically correlated with Peking Man at Zhoukoudian, should be at least 580 k.y. old, or more likely lived during the glacial oxygen isotope stage 16 (˜620 ka). Such an age estimate, which is ˜270 ka older than previous electron spin resonance and alpha-counting U-series dates, has significant implications for the evolution of Asian H. erectus. Dentine and enamel samples from the coexisting fossil layer yield significantly younger apparent ages, that of the enamel sample being only less than one-fourth of the minimum age of Nanjing Man. This suggests that U uptake history is far more complex than existing models can handle. As a result, great care must be taken in the interpretation of electron spin resonance and U-series dates of fossil teeth.

  12. Using Pb-210/Ra-226 disequilibria for sablefish, Anoplopoma fimbria, age validation

    SciTech Connect

    Kastelle, C.R.; Kimura, D.K. ); Nevissi, A.E.; Gunderson, D.R. )

    1994-04-01

    Age determination of sablefish (Anoplopoma fimbria) is typically done by counting growth zones on the burnt cross-section of the otolith. The break-and-burn method of age determination is difficult to apply to sablefish. Therefore, we applied a relatively new method of fish age validation, using the disequilibrium of Pb-210/Ra-226 in the otoliths. This method of validation complements previous methods which used oxytetracycline (OTC) marking to validate incremental growth in sablefish otoliths. The Pb-210/Ra-226 disequilibria generally confirmed the ageing criteria used to interpret the otolith's burnt cross-section.

  13. Symbiont survival and host-symbiont disequilibria under differential vertical transmission.

    PubMed Central

    Sánchez, M S; Arnold, J; Asmussen, M A

    2000-01-01

    Interspecific genetic interactions in host-symbiont systems raise intriguing coevolutionary questions and may influence the effectiveness of public health and management policies. Here we present an analytical and numerical investigation of the effects of host genetic heterogeneity in the rate of vertical transmission of a symbiont. We consider the baseline case with a monomorphic symbiont and a single diallelic locus in its diploid host, where vertical transmission is the sole force. Our analysis introduces interspecific disequilibria to quantify nonrandom associations between host genotypes and alleles and symbiont presence/absence. The transient and equilibrium behavior is examined in simulations with randomly generated initial conditions and transmission parameters. Compared to the case where vertical transmission rates are uniform across host genotypes, differential transmission (i) increases average symbiont survival from 50% to almost 60%, (ii) dramatically reduces the minimum average transmission rate for symbiont survival from 0.5 to 0.008, and (iii) readily creates permanent host-symbiont disequilibria de novo, whereas uniform transmission can neither create nor maintain such associations. On average, heterozygotes are slightly more likely to carry and maintain the symbiont in the population and are more randomly associated with the symbiont. Results show that simple evolutionary forces can create substantial nonrandom associations between two species. PMID:10757775

  14. The U-series dating of (biogenic) carbonates C Hillaire-Marcel

    E-print Network

    significance of U- & Th-series ages, and often leads to model-age dating in situations where this chemicalThe U-series dating of (biogenic) carbonates C Hillaire-Marcel GEOTOP, Université du Québec à array of isotopes that constitute magnifying "lenses" into recent temporal dimensions of Earth System

  15. Mid-ocean ridge basalt generation along the slow-spreading, South Mid-Atlantic Ridge (5-11°S): Inferences from 238U-230Th-226Ra disequilibria

    NASA Astrophysics Data System (ADS)

    Turner, Simon; Kokfelt, Thomas; Hauff, Folkmar; Haase, Karsten; Lundstrom, Craig; Hoernle, Kaj; Yeo, Isobel; Devey, Colin

    2015-11-01

    U-series disequilibria have provided important constraints on the physical processes of partial melting that produce basaltic magma beneath mid-ocean ridges. Here we present the first 238U-230Th-226Ra isotope data for a suite of 83 basalts sampled between 5°S and 11°S along the South Mid-Atlantic Ridge. This section of the ridge can be divided into 5 segments (A0-A4) and the depths to the ridge axis span much of the global range, varying from 1429 to 4514 m. Previous work has also demonstrated that strong trace element and radiogenic isotope heterogeneity existed in the source regions of these basalts. Accordingly, this area provides an ideal location in which to investigate the effects of both inferred melt column length and recycled materials. 226Ra-230Th disequilibria indicate that the majority of the basalts are less than a few millennia old such that their 230Th values do not require any age correction. The U-Th isotope data span a significant range from secular equilibrium up to 32% 230Th excess, also similar to the global range, and vary from segment to segment. However, the (230Th/238U) ratios are not negatively correlated with axial depth and the samples with the largest 230Th excesses come from the deepest ridge segment (A1). Two sub-parallel and positively sloped arrays (for segments A0-2 and A3 and A4) between (230Th/238U) and Th/U ratios can be modelled in various ways as mixing between melts from peridotite and recycled mafic lithologies. Despite abundant evidence for source heterogeneity, there is no simple correlation between (230Th/238U) and radiogenic isotope ratios suggesting that at least some of the trace element and radiogenic isotope variability may have been imparted to the source regions >350 kyr prior to partial melting to produce the basalts. In our preferred model, the two (230Th/238U) versus Th/U arrays can be explained by mixing of melts from one or more recycled mafic lithologies with melts derived from chemically heterogeneous peridotite source regions.

  16. Evaluation of New Geological Reference Materials for U-Series Measurements

    NASA Astrophysics Data System (ADS)

    Denton, J. S.; Goldstein, S. J.; Nunn, A. J.; Ui Chearnaigh, K.; Amato, R.; Murrell, M. T.

    2012-12-01

    Uranium-series analytical measurements are widely used in geochemistry, geochronology, paleoclimatology, volcanology, environmental risk assessment and other fields. Recent advances in high-resolution, rapid, in situ microanalytical techniques e.g. LA-ICP-MS and SIMS present numerous opportunities for the geoanalytical community. As with other analytical techniques, the quality of the elemental concentration and isotopic data obtained through microanalytical techniques is dependent on the accurate characterization of suitable reference materials. Even for the case of fs-laser ablation applications, a range of well-characterized standards are required for high precision U-series work. Advances have been made in evaluating existing standard reference materials for U-series isotopic analysis, but this work is ongoing as more reference materials become available. In this study we present MC-TIMS and MC-ICP-MS results for uranium and thorium isotopic ratios and elemental concentrations measured in a suite of newly available Chinese Geological Standard Glasses (CGSG) designed for microanalysis. These glasses exhibit a range of chemical compositions including basalt, syenite, andesite and a soil. U concentrations for these glasses range from ?2 to 14 ?g/g and [Th]/[U] ratios range from ?4 to 6. Uranium and thorium concentration and isotopic data will also be presented for rhyolitic obsidian from Macusani, SE Peru, which can be used as a rhyolitic reference material. These high-precision and high-accuracy ratios, from a suite of standards that exhibit a range of natural, non-basaltic compositions, will complement data from existing standards and expand the catalogue of reference materials that are appropriate for in situ U-series work. These results can be used to assess the performance of microanalytical techniques and will facilitate inter-laboratory comparison of data within the broader geoscience community.

  17. U-series dating of Locality 15 at Zhoukoudian, China, and implications for hominid evolution

    NASA Astrophysics Data System (ADS)

    Shen, Guanjun J.; Gao, Xing; Zhao, Jian-xin; Collerson, Kenneth D.

    2004-09-01

    This paper reports U-series dates on speleothem samples from Locality 15 at Zhoukoudian, one of the richest Paleolithic sites in northern China. The age of the lower part of Layer 2 is securely bracketed between 155,000 and 284,000 yr. The underlying Layer 3 dates back at least 284,000 yr. Layer 4, further below, should be older still, possibly by a cycle on the SPECMAP time scale before 284,000 yr ago. These ages, much greater than the previous estimates of 110,000-140,000 yr from U-series and electron spin resonance dating of fossil teeth, suggest that Locality 15 was broadly contemporaneous with Locality 4 (New Cave) and with the uppermost strata of Locality 1 (Peking Man site). The physical evolution and cultural development evidenced by the timing of the Zhoukoudian localities are in line with the opinion of Chinese anthropologists for a regional transition from Homo erectus to archaic Homo sapiens.

  18. Use of U-Series Isotopic Disequilibrium to Investigate the Nature and Distribution of Actively Flowing Fractures

    NASA Astrophysics Data System (ADS)

    Nichols, P. J.; Paces, J. B.; Neymark, L. A.; Rajaram, H.

    2011-12-01

    Groundwater transport of radioisotopes from underground nuclear tests at the Nevada National Security Site (NNSS) is of concern to the U.S. Department of Energy. Extensive testing was conducted near or below the regional water table (saturated zone; SZ) at Pahute Mesa and within the unsaturated (or partially saturated) zone at Rainier Mesa. Groundwater flow in these rocks is believed to occur mainly through a connected network of fractures. To better understand flow in these fractured rocks, we analyzed U-series isotopes (238U-234U-230Th) from drill core samples. In rock isolated from flow over the last million years, isotopes in the 238U decay chain reach a state of radioactive secular equilibrium, where 234U/238U and 230Th/238U activity ratios (AR) = 1.0. More recent water-rock interaction results in mobilization of 234U relative to 238U, and U relative to Th in migrating waters. Rock surfaces that incorporate this U or are leached of 234U and U will show U-series disequilibrium. Isotope data can thus provide time-sensitive information on hydrologic conditions in host rocks without directly observing or measuring flowing water. To investigate NNSS fracture networks, core was selected from confining units (bedded and zeolitized felsic tuffs) and aquifers (felsic welded tuffs and lavas) in five boreholes on Pahute Mesa and two boreholes on Rainier Mesa. Samples include interiors of intact core as well as natural fracture surfaces and brecciated core. Intact core and brecciated samples were crushed and powdered. Fracture surfaces were sampled using dental burs to remove the outer 0.1 to 0.5 mm of fracture surfaces, which may have thin mineral coatings of zeolites, clays, and Mn oxides. Samples were totally digested, spiked with a 236U-229Th tracer, and analyzed by a solid-source TRITON° mass spectrometer equipped with an energy filter and single ion counter. Results show that 8 of 9 intact core samples have 234U/238U AR within ±5% of 1.0, suggesting little or no water-rock interaction over the last several hundred thousand years. In contrast, discrete fracture surfaces (N=37) have 234U/238U AR ranging from 2.09 to 0.34, although the median value is 1.04. About one third of the 28 SZ fracture surfaces have 234U/238U AR within 5% of 1.0. Remaining SZ fractures tend to have 234U/238U > 1.0,indicating that U incorporation from migrating groundwater (234U/238U AR ? 2-4) is an important process. Furthermore, samples with isotopic disequilibrium commonly plot along the equiline (equal 234U/238U and 230Th/238U AR) regardless of sample type or location. This pattern cannot be explained by deposition and closed-system isotope evolution of secondary minerals. Instead, it suggests a quasi-steady-state balance of processes including sorption or leaching of U associated with migrating solutions and in-situ production, decay, and ?-recoil of 230Th and 234U. These data will be used to help constrain numerical models of fracture-matrix interaction and spatial distribution of flowing versus non-flowing fractures.

  19. U-series dating of impure carbonates: An isochron technique using total-sample dissolution

    USGS Publications Warehouse

    Bischoff, J.L.; Fitzpatrick, J.A.

    1991-01-01

    U-series dating is a well-established technique for age determination of Late Quaternary carbonates. Materials of sufficient purity for nominal dating, however, are not as common as materials with mechanically inseparable aluminosilicate detritus. Detritus contaminates the sample with extraneous Th. We propose that correction for contamination is best accomplished with the isochron technique using total sample dissolution (TSD). Experiments were conducted on artificial mixtures of natural detritus and carbonate and on an impure carbonate of known age. Results show that significant and unpredictable transfer of radionuclides occur from the detritus to the leachate in commonly used selective leaching procedures. The effects of correcting via leachate-residue pairs and isochron plots were assessed. Isochrons using TSD gave best results, followed by isochron plots of leachates only. ?? 1991.

  20. U-series dating and stable isotope records of speleothem records from the Scladina Cave (Belgium)

    NASA Astrophysics Data System (ADS)

    van der Lubbe, Jeroen; Bonjean, Dominique; Hellstrom, John; Verheyden, Sophie; Vonhof, Hubert

    2015-04-01

    The Scladina cave, situated in the village of Sclayn (Ardennes, Belgium) at the southern bank of the Meuse, is famous for its Neanderthal fossils and artefacts. The infilling of the cave consists of a succession of flowstone layers interbedded with reworked loess sediment from outside the cave. The younger flowstone layers correspond to interglacials MIS 5 and the Holocene, while the reworked loess sediments represent cooler conditions. By careful diagenetic screening, well-preserved speleothem material was selected for U-series dating and stable isotope analysis of calcite and fluid inclusions. The results provide important new constraints on the age of Neanderthal fossils and artefacts, and bracket the time periods with a hydroclimate favorable for speleothem growth. The combination of fluid inclusion and calcite isotope analysis documents climate variability in the interglacials at high temporal resolution.

  1. Radioactive Waste Radioactive Waste

    E-print Network

    Slatton, Clint

    #12;Radioactive Waste at UF Bldg 831 392-8400 #12;Radioactive Waste · Program is designed to;Radioactive Waste · Program requires · Generator support · Proper segregation · Packaging · labeling #12;Radioactive Waste · What is radioactive waste? · Anything that · Contains · or is contaminated

  2. The tetranucleotide repeat polymorphism C2_4_4: population data and linkage disequilibria with HLA class I.

    PubMed

    Stadlbacher, Simone; Dauber, Eva-Maria; Wenda, Sabine; Glock, Barbara; Hafner, Maria; Körmöczi, Günther F; Mayr, Wolfgang R

    2003-01-01

    The tetranucleotide repeat locus C2_4_4 situated in the HLA class I region (6p21.3) and the HLA-ABC specificities were investigated in an Austrian population sample of 240 unrelated Caucasoid individuals. The analysis of the linkage disequilibrium between C2_4_4 and HLA class I showed several significant values, especially when factors coded for by so-called "superhaplotypes" were considered; such linkage disequilibria are of importance for the practical use of HLA coded short tandem repeats. PMID:12675271

  3. U-series and oxygen isotope chronology of the mid-Pleistocene Lake Amora (Dead Sea basin)

    E-print Network

    Torfstein, Adi

    U-series and oxygen isotope chronology of the mid-Pleistocene Lake Amora (Dead Sea basin) Adi of Lake Amora (Dead Sea basin, Israel), whose deposits (the Amora Formation) comprise one of the longest (Marine Isotope Stages (MIS) 18 to 5). Taking the last glacial Lake Lisan and the Holocene Dead Sea

  4. Carbonate mound evolution and coral diagenesis viewed by U-series dating of deep water corals

    NASA Astrophysics Data System (ADS)

    Frank, N.; Ricard, E.; Blamart, D.; van der Land, C.; Colin, C.; Foubert, A.; van Rooij, D.; van Weering, T.

    2007-12-01

    U-series dating of constructional deep sea corals is a powerful tool to reconstruct the evolution of carbonate mound sediments driven by coral growth, sediment trapping and diagenesis. Here we have investigated in great detail the time framework of constructional corals such as L. pertusa and M. oculata on 5 different mounds of the eastern North Atlantic (on Rockall Bank and in Porcupine Seabight) taken at variable depth and location (610 to 880m water depth). Periods favorable for coral growth are the Holocene and prior interglacials such as marine isotope stage 5 and 7, while glacial coral growth seems inhibited or extremely reduced. Coral development is almost continuous throughout the Holocene since mound re-colonization about 10,500 years ago. Mound accumulation rates vary between 20 and 220 cm/kyr determined from the coral age - depth relationship in each core. Those changes are most likely driven by changes between horizontal and vertical mound accumulation, food supply and ocean circulation. In addition, coral dating allowed to identify an important erosional event recorded in core MD01-2455G from Rockall Bank. Here a 1m thick sediment layer containing ancient corals likely from the start of Holocene re-colonization was displaced (collapsed) from further upslope on top of younger corals of ~2500 to 3000 years age. Prior to the initiation of coral growth diagenesis occurred frequently resulting in (1) the construction of so called carbonate hardgrounds and/or (2) the dissolution of the pre-Holocene coral framework. Solely, the deepest selected core in Porcupine Seabight (MD01-2463G at 880m depth) reveals coral re-colonization on an undisturbed ancient reef structure that dates back to 250,000 years. Diagenesis of earlier coral reef generations leading to coral dissolution leads to a loss of magnetic susceptibility and open system behavior of the coral skeletons with respect to U-series dating. While the processes causing such diagenetic layers are barely understood the disappearance of the magnetic susceptibility can be used to trace such phenomena and a conserved magnetic susceptibility allows sampling of well preserved corals.

  5. New U-series dates at the Caune de l'Arago, France

    USGS Publications Warehouse

    Falgueres, Christophe; Yokoyama, Y.; Shen, G.; Bischoff, J.L.; Ku, T.-L.; de Lumley, Henry

    2004-01-01

    In the beginning of the 1980s, the Caune de l'Arago was the focus of an interdisciplinary effort to establish the chronology of the Homo heidelbergensis (Preneandertals) fossils using a variety of techniques on bones and on speleothems. The result was a very large spread of dates particularly on bone samples. Amid the large spread of results, some radiometric data on speleothems showed a convergence in agreement with inferences from faunal studies. We present new U-series results on the stalagmitic formation located at the bottom of Unit IV (at the base of the Upper Stratigraphic Complex). Samples and splits were collaboratively analyzed in the four different laboratories with excellent interlaboratory agreement. Results show the complex sequence of this stalagmitic formation. The most ancient part is systematically at internal isotopic equilibrium (>350 ka) suggesting growth during or before isotopic stage 9, representing a minimum age for the human remains found in Unit III of the Middle Stratigraphical Complex which is stratigraphically under the basis of the studied stalagmitic formation. Overlaying parts of the speleothem date to the beginning of marine isotope stages 7 and 5. ?? 2003 Elsevier Science Ltd. All rights reserved.

  6. New U-series dates at the Caune de l'Arago, France

    USGS Publications Warehouse

    Falgueres, Christophe; Yokoyama, Y.; Shen, G.; Bischoff, J.L.; Ku, T.-L.; de Lumley, Henry

    2004-01-01

    In the beginning of the 1980s, the Caune de l'Arago was the focus of an interdisciplinary effort to establish the chronology of the Homo heidelbergensis (Preneandertals) fossils using a variety of techniques on bones and on speleothems. The result was a very large spread of dates particularly on bone samples. Amid the large spread of results, some radiometric data on speleothems showed a convergence in agreement with inferences from faunal studies. We present new U-series results on the stalagmitic formation located at the bottom of Unit IV (at the base of the Upper Stratigraphic Complex). Samples and splits were collaboratively analyzed in the four different laboratories with excellent interlaboratory agreement. Results show the complex sequence of this stalagmitic formation. The most ancient part is systematically at internal isotopic equilibrium (>350 ka) suggesting growth during or before isotopic stage 9, representing a minimum age for the human remains found in Unit III of the Middle Stratigraphical Complex which is stratigraphically under the basis of the studied stalagmitic formation. Overlaying parts of the speleothem date to the beginning of marine isotope stages 7 and 5. ?? 2003 Elsevier Ltd. All rights reserved.

  7. ESR, U-series and paleomagnetic dating of Gigantopithecus fauna from Chuifeng Cave, Guangxi, southern China

    NASA Astrophysics Data System (ADS)

    Shao, Qingfeng; Wang, Wei; Deng, Chenglong; Voinchet, Pierre; Lin, Min; Zazzo, Antoine; Douville, Eric; Dolo, Jean-Michel; Falguères, Christophe; Bahain, Jean-Jacques

    2014-07-01

    Several Gigantopithecus faunas associated with taxonomically undetermined hominoid fossils and/or stone artifacts are known from southern China. These faunas are particularly important for the study of the evolution of humans and other mammals in Asia. However, the geochronology of the Gigantopithecus faunas remains uncertain. In order to solve this problem, a program of geochronological studies of Gigantopithecus faunas in Guangxi Province was recently initiated. Chuifeng Cave is the first studied site, which yielded 92 Gigantopithecus blacki teeth associated with numerous other mammalian fossils. We carried out combined ESR/U-series dating of fossil teeth and sediment paleomagnetic studies. Our ESR results suggest that the lower layers at this cave can be dated to 1.92 ± 0.14 Ma and the upper layers can be dated to older than 1.38 ± 0.17 Ma. Correlation of the recognized magnetozones to the geomagnetic polarity timescale was achieved by combining magnetostratigraphic, biostratigraphic and ESR data. The combined chronologies establish an Olduvai subchron (1.945-1.778 Ma) for the lowermost Chuifeng Cave sediments. We also analyzed the enamel ?13C values of the Gigantopithecus faunas. Our results show that southern China was dominated by C3 plants during the early Pleistocene and that the Gigantopithecus faunas lived in a woodland-forest ecosystem.

  8. U-series ages of solitary corals from the California coast by mass spectrometry

    SciTech Connect

    Stein, M.; Wasserburg, G.J.; Chen, J.H. ); Lajoie, K.R. )

    1991-12-01

    The purpose of this study is to evaluate the feasibility of dating fossil solitary corals from Pleistocene marine strandlines outside tropical latitudes using the recently developed high sensitivity, high-precision U-series technique based on thermal-ionization mass-spectrometry (TIMS). The TIMS technique is much more efficient than conventional {alpha} spectrometry and, as a result, multiple samples of an individual coral skeleton, or different specimens from the same bed can be analyzed. Detached and well-rounded fossil specimens of the solitary coral Balanophyllia elegans were collected from relict littoral deposits on emergent marine terraces along the California coast at Cayucos terrace, Shell Beach terrace, Nestor terrace, San Diego, Bird Rock terrace, San Diego. Attached living specimens were collected from the intertidal zone on the modern terrace at Moss Beach. The calculated initial {sup 234}U activities in the fossil specimens of Balanophyllia elegans are higher than the {sup 234}U activity in modern seawater or in the modern specimen. The higher initial activities could possibly reflect the influx of {sup 234}U-enriched continental water into Pleistocene coastal waters, or it could reflect the influx of {sup 234}U-enriched continental water into Pleistocene coastal waters, or it could reflect minor diagenetic alteration, a persistent and fundamental problem in dating all corals.

  9. U-series constraints on the Holocene human presence in the Cuatro Cienegas basin, Mexico

    NASA Astrophysics Data System (ADS)

    Noble, S. R.; Felstead, N.; Gonzalez, S.; Leng, M. J.; Metcalfe, S. E.; Patchett, P. J.

    2010-12-01

    U-series tufa ages dating a human trackway have been obtained, part of a larger Late Pleistocene - Recent palaeoclimate and human occupation study of the Cuatro Cienegas basin, NE Mexico. Our analytical approach, including tracer calibration, couples aspects of what we consider best practice in the U-series community with our U-Pb experiences which includes the EarthTime U-Pb tracer calibration exercise. The recently discovered trackway is near a small hydrothermal pool within the basin [1], an ecologically highly significant oasis in the Chihuahuan desert. The oasis comprises >200 freshwater hydrothermal pools and a river system, and the related ecosystem hosts >70 endemic species[2]. Pools are fed by waters that circulate a deep karstic system and that originate in the surrounding upper Jurassic-lower Cretaceous Sierra Madre Oriental mountains (>3000m) [3]. The area hosted nomadic hunter-gatherers during the Holocene, and possibly as early as Late Pleistocene (~12 ka BP). Despite the basin's ecological significance, only three palaeoenvironmental studies have been published to date, and limited geochronological constraints are available. A pollen study of drill core through peats and tufas proximal to the pools suggested a long period of climatic stability and biogeographic isolation[4], a notion supported by the large number of endemic species, but other palynological and plant macrofossil data suggest that large climatic changes occurred post Late Pleistocene [5]. The 10 m long in situ trackway is preserved in tufa and five samples from the uppermost surfaces were analysed to date the footprints. The tufas comprise clean carbonate with no petrographic evidence of replacement and little contaminant detrital material (on some exposed upper surfaces). Powdered tufa was processed following [6-8], and analysed by TIMS (Triton, U) and MC-ICP-MS (Th, Nu HR), although our future analyses will primarily be obtained on a Neptune. Samples were spiked with a 229Th/236U tracer calibrated against gravimetric solutions prepared from Ames high-purity Th metal crystal and CRM 112a U metal ingot rather than natural materials of assumed secular equilibrium. ICP-MS mass bias and Faraday-SEM gain was monitored using CRM 112a and an in-house 229Th-230Th-232Th solution. Most samples have relatively high U contents (~2 ppm U), moderate [230Th/232Th] = 29-44, and initial [234U/238U] ~ 1.92. We obtain an age of 7.24 ± 0.13 ka BP for this trackway based on an average of two samples of the uppermost tufa surface. Depth profiling of one sample shows consistently increasing age downwards (~370 a/cm). [1] Gonzalez, A.H.G. et al., 2006, Ichnos 16, 12-24;[2] Souza, V. et al., 2006, PNAS 103, 6565-6570; [3] Johannesson, K.H. et al., 2004, J.S.Am.Earth Sci. 17, 171-180; [4] Meyer, E. 1973, Ecology 54, 982-995; [5] Minckley, T.A. & Jackson, S. 2008. J. Biogeography 35, 188-190; [6] Edwards, R.L. et al., 1987, EPSL 81, 175-192; [8] Cheng, H. et al., 2000, Chem. Geol. 169, 17-33; [8] Potter, E.K. et al., 2005, EPSL 247, 10-17.

  10. Short-lived radioactivity and magma genesis.

    PubMed

    Gill, J; Condomines, M

    1992-09-01

    Short-lived decay products of uranium and thorium have half-lives and chemistries sensitive to the processes and time scales of magma genesis, including partial melting in the mantle and magmatic differentiation in the crust. Radioactive disequilibrium between (238)U, (230)Th, and (226)Ra is widespread in volcanic rocks. These disequilibria and the isotopic composition of thorium depend especially on the extent and rate of melting as well as the presence and composition of vapor during melting. The duration of mantle melting may be several hundred millennia, whereas ascent times are a few decades to thousands of years. Differentiation of most magmas commonly occurs within a few millennia, but felsic ones can be tens of millennia old upon eruption. PMID:17738278

  11. Middle Palaeolithic refugium, or archaeological misconception? A new U-Series and radiocarbon chronology of Abric Agut (Capellades, Spain)

    USGS Publications Warehouse

    Vaquero, Manola; Esteban, M.; Allue, E.; Vallverdu, J.; Carbonell, E.; Bischoff, J.L.

    2002-01-01

    New U-Series and C14 (AMS) dates are provided for the Abric Agut (Capellades, Barcelona, Spain). This site was previously considered to be of Middle Palaeolithic age according to the characteristics of the lithic assemblage. In addition, human teeth were uncovered and attributed to neandertals. However, radiometric dating clearly indicates a Late Pleistocene-Early Holocene age. ?? 2002 Elsevier Science Ltd. All rights reserved.

  12. U-series Chronology of volcanoes in the Central Kenya Peralkaline Province, East African Rift

    NASA Astrophysics Data System (ADS)

    Negron, L. M.; Ma, L.; Deino, A.; Anthony, E. Y.

    2012-12-01

    We are studying the East African Rift System (EARS) in the Central Kenya Peralkaline Province (CKPP), and specifically the young volcanoes Mt. Suswa, Longonot, and Menengai. Ar dates by Al Deino on K-feldspar phenocrysts show a strong correlation between older Ar ages and decreasing 230Th/232Th, which we interpret to reflect the age of eruption. This system has been the subject of recent research done by several UTEP alumni including Antony Wamalwa using potential field and magnetotelluric (MT) data to identify and characterize fractures and hydrothermal fluids. Also research on geochemical modeling done by John White, Vanessa Espejel and Peter Omenda led to the hypothesis of possible disequilibrium in these young, mainly obsidian samples in their post eruptive history. A pilot study of 8 samples, (also including W-2a USGS standard and a blank) establish the correlation that was seen between the ages found by Deino along with the 230/232Th ratios. All 8 samples from Mt. Suswa showed a 234U/238U ratio of (1) which indicates secular equilibrium or unity and that these are very fresh samples with no post-eruptive decay or leaching of U isotopes. The pilot set was comprised of four samples from the ring-trench group (RTG) with ages ranging from 7ka-present, two samples from the post-caldera stage ranging from 31-10ka, one sample from the syn-caldera stage dated at 41ka, and one sample from the pre-caldera stage dated at 112ka. The young RTG had a 230/232Th fractionation ratio of 0.8 ranging to the older pre-caldera stage with a 230/232Th ratio of 0.6. From this current data and research of 14C ages by Nick Rogers, the data from Longonot volcano was also similar to the 230/232Th ratio we found. Rogers' data places Longonot volcano ages to be no more than 20ka with the youngest samples also roughly around 0.8 disequilibrium. These strong correlations between the pilot study done for Mt. Suswa, 40Ar ages by Deino, along with 14C ages from Rogers have led to the exploration of present U-series data set of the youngest samples from the rest of the CKPP volcanoes including: Menengai, more from Longonot, and Olkaria. And since it is observed that there is the presence of lateral migration along an axial dike swarm that has operated in other parts of the EARS, we have chosen to run samples from the adjacent mafic fields of Elmenteita, Tandamara, and Ndabibi to see if there is a trend in the correlation of the 230/232Th ratios at the time of eruption as well as observing how close these samples get to unity. This would answer questions as to whether similar 230/232Th ratios imply that the mafic fields feed the calderas.

  13. U-series dating of pillow rim glass from recent volcanism at an Axial Volcanic Ridge

    NASA Astrophysics Data System (ADS)

    Thomas, L. E.; van Calsteren, P. W.; Jc024 Shipboard Party

    2010-12-01

    Visual observations using camera systems on the tethered ROV Isis deployed during the 2008 JC024 cruise to the Mid Atlantic Ridge at 45°N showed1 numerous monogenetic volcanoes that are essentially piles of lava pillows. The pillows are usually ˜1m diameter and >2m long and form mounds with average dimensions around 300m diameter, ˜150m altitude, and 0.005km3 volume. Small protrusions, 10-50cm long, which are numerous on pillows appear to be the youngest regions, were sampled using the pincers on the hydraulic arms of Isis, and returned to the surface. On the surface, any glass crust on the pillow protrusions was chiselled off using clean tools and double bagged in polythene. In the laboratory a portion of the glass was crushed in a jeweller’s roller mill and sieved using stainless steel sieves to obtain a sufficient amount of the fraction 0.125-0.250mm for hand picking, using a binocular microscope with the glass submerged in a mix of water and iso-propyl alcohol. The samples were subsequently leached using the procedure of Standish & Sims2. Samples were spiked with a mixed 229Th-236U spike and the U, Th and Ra fractions were separated and purified using standard chemistry methods. U and Th isotope ratios were determined using a Nu Instruments MC-ICPMS and Ra isotope ratios were determined using a MAT-262-RPQII TIMS instrument. The U-series data were evaluated using a MathCad program based on published4,5,6 equations. The data can be successfully modelled by assuming the ‘accepted’ mantle upwelling rate for the region of 11mm.y-1. The U-Th characteristics are mostly derived during ‘porous flow’ magma upwelling in the garnet stability zone, ranging to a depth of 60km with incipient melting starting at 70km. Above 60km depth the melt fraction will be >3% and the mantle mineralogy devoid of phases that fractionate U-Th significantly. Moreover, at melt fractions >3%, channel flow will be dominant and magma will transit to eruption on time-scales that are short enough to retain the U-Th characteristics from the garnet zone. The rheology of the deep mantle is such that melt generation should be in ‘steady state’ and U-Th characteristics should be constant. On that assumption, measured differences in collected samples can be used to calculate model ages relative to the ‘youngest’ sample, thus allowing the construction of a relative eruption timescale. However, significant fractional crystallisation is taking place in the oceanic crust, as testified by the frequent presence of plagioclase crystals up to mm-size in the glass samples. A ‘magma chamber’ on a scale larger than the magma channels is not required and we aim to assess the rate of plagioclase crystal growth using a 226Ra chronometer. This chronometer requires the assumption that Ba-Ra fractionation is constant and can then also be used to calculate a relative model age timescale, provided that not all samples are >8000 y old, which we consider unlikely. 1Searle, RC et al, EPSL in press, 2010 2Standish, JJ & Sims, KWW. Nature Geoscience V3, 2010 3Murton, BJ et al, in prep, 2010 4Williams, RW and Gill, JB, GCA 53, 1989 5Spiegelman, M and Elliott, T, EPSL 118, 1993 6Richardson, C and McKenzie, D, EPSL 128, 1994

  14. Magmas, Mushes and Mobility: Thermal Histories of Magma Reservoirs from Combined U-Series and Diffusion Ages

    NASA Astrophysics Data System (ADS)

    Cooper, K. M.; Rubin, A. E.; Schrecengost, K.; Kent, A. J.; Huber, C.

    2014-12-01

    The thermal conditions of magma storage control many aspects of the dynamics of a magma reservoir system. For example, the temperature of magma storage directly relates to the crystallinity, and magmas stored at relatively low temperatures in a crystal mush (more than 40-50% crystalline) must be remobilized (e.g., by heating) before they can be erupted. A better understanding of the duration of magma storage at largely-liquid vs. largely-solid conditions is thus critical to understanding crustal magmatic processes such as magma mixing and for quantifying the hazard potential of a given volcano. Although mineral thermometry reflects the conditions of crystal growth or equilibration, these may not correspond to the thermal conditions of crystal storage. The duration of crystal storage at high temperatures can be quantified by comparing U-series crystal ages with the time scales over which disequilibrium trace-element profiles in the same crystals would be erased by diffusion. In the case of Mount Hood, OR, such a comparison for the two most recent eruptions shows that <12% of the total lifetime of plagioclase crystals (minimum 21 kyr) was spent at temperatures high enough that the magma would be easily mobilized. Partial data sets for other systems suggest such behavior is common, although the diffusion and U-series ages in these cases are from different samples and may not be directly comparable. We will present preliminary data combining U-series dating and diffusion timescales on the same samples for other volcanic systems (e.g., Lassen Volcanic Center, Mount St. Helens, Okataina Volcanic Center, New Zealand). Combining these data with numerical models offers additional insights into the controls on the conditions of storage. In addition, extension of this approach to combining U-Th ages with time scales of Li diffusion in zircon offers a promising new method to quantify thermal histories of silicic reservoir systems.

  15. Uranium-series disequilibria in Vanuatu arc volcanic rocks: constraints on pre-eruptive processes in contrasting volcanic systems

    NASA Astrophysics Data System (ADS)

    Handley, H. K.; Turner, S.; Reagan, M. K.; Girard, G.; Cronin, S. J.; Firth, C.

    2011-12-01

    Recent and present volcanism in the Vanuatu arc (South West Pacific Ocean) occurs at a variety of volcano types that exhibit a wide range of eruptive behaviour: from post-caldera lava-lake activity and lava flows at shield volcanoes (Ambrym), moderately explosive sub-plinian events and associated pyroclastic-flows and lava flows at stratovolcanoes (Lopevi), to persistent strombolian and vulcanian-style eruptions at scoria cones (Yasur). This precludes a generic model of magmatic and eruptive behaviour for the Vantuatu arc volcanoes and necessitates a detailed study of each system. Uranium-series disequilibria in volcanic rocks offer unique insights into pre-eruptive magmatic systems over process-relevant timescales e.g., 238U-230Th (380Ka), 230Th-226Ra (8Ka) and 226Ra-210Pb (100a). The short half-life of 210Pb (t1/2 = 22.6 years) and the volatile nature of the intermediate isotope, 222Rn, (intermediate between the 226Ra parent and 210Pb daughter) provide valuable information on magma transport, evolution and degassing over a timescale more pertinent to the processes leading up to volcanic eruptions. We present new Uranium-series isotope data (U-Th-Ra-210Pb) for young (< 100 years old) volcanic samples from Ambrym, Lopevi and Yasur volcanoes to investigate the timescales of magmatic evolution and degassing in the contrasting volcanic systems. 210Pb deficits ((210Pb/226Ra)0 < 1) in Ambrym and Yasur volcanic rocks suggest effective open-system magmatic degassing of 222Rn, consistent with the persistent lava-lakes/exposed magma and significant gas emissions observed at both volcanoes. Lopevi, on the other hand, largely displays excess 210Pb ((210Pb/226Ra)0 > 1) suggesting that 222Rn gas accumulation and fluxing preceding and/or during eruption (on a decadal timescale) is responsible for the more explosive-style of eruption witnessed at this volcano. Significant accumulation of recently crystallised plagioclase phenocrysts can also create 210Pb excesses in volcanic rocks, however, this process is not supported by the petrographic and geochemical data. In summary 210Pb-226Ra disequilibria in Vanuatu volcanic rocks reveal a strong link between pre-eruptive magma degassing systematics and the resultant style of volcanic activity.

  16. U-Series dates for stalagmitic flowstone E (Riss/Würm interglaciation) at Grotte du Lazaret, Nice, France

    USGS Publications Warehouse

    Falgueres, Christophe; de Lumley, Henry; Bischoff, James L.

    1992-01-01

    Several samples of stalagmitic flowstone (Ensemble E) at Grotte du Lazaret (Nice, France) were dated by U-series isotopes. The results show that this speleothem began to grow about 130,000 yr B.P. and continued to about 70,000 yr B.P., coinciding almost exactly with the last interglaciation (isotope stage 5). Even though Ensemble E is not in direct stratigraphic relation with the cave deposits, this study shows that the Acheulian artifacts industry and fauna within Lazaret are older than the Riss/Wurm interglaciation.

  17. Preliminary U-series disequilibrium and thermoluminescence ages of surficial deposits and paleosols associated with Quaternary faults, eastern Yucca Mountain

    SciTech Connect

    Paces, J.B.; Menges, C.M.; Bush, C.A.; Futa, K.; Millard, H.T.; Maat, P.B.; Whitney, J.W.; Widmann, B.; Wesling, J.R.

    1994-12-31

    Geochronological control is an essential component of paleoseismic evaluation of faults in the Yucca Mountain region. New U-series disequilibrium and thermoluminescence age estimates for pedogenic deposits that bracket surface-rupture events are presented from four sites exposing the Paintbrush Canyon, Bow Ridge and Stagecoach Road faults. Ages show an internal consistency with stratigraphic relationships as well as an overall concordancy between the two independent geochronometers. Age estimates are therefore interpreted to date depositional events or episodes of pedogenic carbonate mobility that can be used to establish a paleoseismic fault chronology. Ultimately, this type of chronological information will be used to evaluate seismic hazards at Yucca Mountain.

  18. Soil formation rates determined from Uranium-series isotope disequilibria in soil profiles from the southeastern Australian highlands

    NASA Astrophysics Data System (ADS)

    Suresh, P. O.; Dosseto, A.; Hesse, P. P.; Handley, H. K.

    2013-10-01

    The sustainability of soil resources is determined by the balance between the rates of production and removal of soils. Samples from four weathering profiles at Frogs Hollow in the upper catchment area of the Murrumbidgee River (southeastern Australia) were analyzed for their uranium-series (U-series) isotopic composition to estimate soil production rates. Sequential leaching was conducted on sample aliquots to assess how U-series nuclides are distributed between primary and secondary minerals. Soil is increasingly weathered from bottom to top which is evident from the decrease in (234U/238U) ratios and increase in relative quartz content with decreasing soil depth. One soil profile shows little variation in mineralogy and U-series geochemistry with depth, explained by the occurrence of already extensively weathered saprolite, so that further weathering has minimal effect on mineralogy and geochemistry. Al2O3 is mobilized from these soils, and hence a silicon-based weathering index treating Al2O3 as mobile is introduced, which increases with decreasing soil depth, in all profiles. Leached and unleached aliquots show similar mineralogy with slight variation in relative concentrations, whereas the elemental and isotopic composition of uranium and thorium show notable differences between leached and unleached samples. Unleached samples show systematic variations in uranium-series isotopic compositions with depth compared to leached samples. This is most likely explained by the mobilization of U and Th from the samples during leaching. Soil residence times are calculated by modeling U-series activity ratios for each profile separately. Inferred timescales vary up to 30 kyr for unleached aliquots from profile F1 to up to 12 kyr for both leached and unleached aliquots from profile F2. Muscovite content shows a linear relationship with U-series derived soil residence times. This relationship provides an alternative method to estimate residence timescales for profiles with significant U-series data scatter. Using this alternative approach, inferred soil residence times up to 33 kyr for leached samples of profile F1 and up to 34 kyr for leached samples of profile F3 were determined. A linear relationship between soil residence times and WIS (Si-based Weathering Index) exists and is used to estimate soil residence times for profile F3 (up to 28 kyr) and F4 (up to 37 kyr). The linear relationship between soil depth and calculated residence time allows determination of soil production rates, which range from 10 to 24 mm/kyr and are comparable to the rates determined previously using cosmogenic isotopes at the same site (Heimsath et al., 2001b). This implies that at this site, on the highland plateau of southeastern Australia, soil thickness has reached steady-state, possibly as a result of stable tectonic conditions but despite variable climatic conditions over the timescale of soil development. Soil-mantled landscapes are the geomorphic expression of this balance between soil production and denudation, and our results show that in tectonically quiescent regions, this landscape can be achieved in less than 30 kyr.

  19. U-series ages of solitary corals from the California coast by mass spectrometry

    USGS Publications Warehouse

    Stein, Martin; Wasserburg, G.J.; Lajoie, K.R.; Chen, J.-H.

    1991-01-01

    The purpose of this study is to evaluate the feasibility of dating fossil solitary corals from Pleistocene marine strandlines outside tropical latitudes using the recently developed high sensitivity, high-precision U-series technique based on thermal-ionization mass-spectrometry (TIMS). The TIMS technique is much more efficient than conventional a spectrometry and, as a result, multiple samples of an individual coral skeleton, or different specimens from the same bed can be analyzed. Detached and well-rounded fossil specimens of the solitary coral Balanophyllia elegans were collected from relict littoral deposits on emergent marine terraces along the California coast at Cayucos terrace (elevation 8 m, previously dated at 124 and 117 Ky by ?? counting), Shell Beach terrace (elevation about 25 m, previously undated), Nestor terrace, San Diego (elevation 23 m, previously dated at 131 to 109 Ky ), Bird Rock terrace, San Diego ( elevation 8 m, previously dated at 81 Ky ). Attached living specimens were collected from the intertidal zone on the modern terrace at Moss Beach. Concentrations of 232Th in both living and fossil specimens are much higher than in reef-building corals (12 to 624 pmol/g vs. 0.1 to 1.6 pmol/g, respectively). However, because 230Th/232Th in Balanophyllia elegans are very low (2.22 ?? 10-3 to 4.33 ?? 10-4), the high 232Th concentrations have negligible effect on the 230Th-234U dates. The high 232Th concentration in the living specimen (33.1 pmol/g) indicates that a significant amount of 232Th is incorporated in the aragonitic skeleton during growth, or attached to clay-sized silicates trapped in the skeletal material. The calculated initial 234U activities in the fossil specimens of Balanophyllia elegans are higher than the 234U activity in modern seawater or in the modern specimen. The higher initial activities could possibly reflect the influx of 234U-enriched continental water into Pleistocene coastal waters, or it could reflect minor diagenetic alteration, a persistent and fundamental problem in dating all corals. Samples from a compound specimen from the Cayucos terrace were subjected to different preparation procedures. Samples prepared by a standard acid washing procedure yielded 230Th-234U ages of 125, 123, and 122 Ky, whereas samples prepared by an abbreviated procedure without acid washing yield significantly lower ages of 113 and 112 Ky. Two other specimens from the same bed yielded 230Th-234U ages of 118 and 115 Ky. Also, two specimens from a stratigraphically higher bed yielded ages of 120 and 117 Ky, and three specimens from a lower bed yield ages of 115, 113, and 101 Ky. Nine of the twelve ages of the treated samples from the Cayucos terrace range from 125 to 113 Ky. However, the ages do not follow the stratigraphie order. Two possible interpretations are ( 1 ) the age of the terrace deposit is 125 Ky and all younger ages reflect variable diagenetic alteration or (2) the age of the terrace is 125 to 113 Ky and the ages reflect sediment reworking over a period of 12 Ky. Three specimens from a single bed on the Shell Beach terrace yield ages of 126, 122, and 121 Ky, similar to the older ages from Cayucos. The ages of solitary corals from the Cayucos and Shell Beach terraces are similar to ages of reef-building corals from terraces at numerous tropical localities. These are correlated with the last interglacial sea-level highstand, which probably stood 2 to 10 m above present sea level. The youngest ages and present elevations of the Cayucos and Shell Beach terraces yield tectonic uplift rates of 0.01 and 0.15 m/Ky, respectively, assuming the original elevation of each terrace was 7 m. Four specimens from the basal gravel on the Nestor terrace yielded ages of 145, 143, 137, and 133 Ky. The three oldest ages, however, are older than that associated with the last interglacial. The possible explanations for these older ages are ( 1 ) diagenic alteration or ( 2 ) the Nestor terrace deposits reflect in s

  20. Internal [sup 238]U-series systematics of pumice from the November 13, 1985, eruption of Nevado de Ruiz, Colombia

    SciTech Connect

    Schaefer, S.J.; Williams, S.N. ); Sturchio, N.C. ); Murrell, M.T. )

    1993-03-01

    High-precision mass spectrometer and alpha scintillation measurements of [sup 238]U-series nuclides were obtained for whole-rock pumice and constituent mineral and glass separates to help interpret the timing and nature of magmatic processes that led up to the 1985 eruption of Nevado de Ruiz volcano. Internal isochron diagrams for [sup 226]Ra/Ba vs. [sup 230]Th/Ba and [sup 230]Th/[sup 232]Th vs. [sup 238]U/[sup 232]Th show that data define linear arrays, indicating an average crystallization age of 6.1 [+-] 0.5 ka (Ra-Th isochron) and 7 [+-] 6 ka (Th-U isochron). Stratigraphic, petrographic geochemical, repose time, and eruption volume data for the Holocene eruptive sequence of Nevado del Ruiz indicate that significant changes occurred in the subvolcanic magma chamber between eruptions R9 ([approx]8.6 ka) and R8 ([approx]3.0 ka). This coincides with the average crystallization age derived from the U-series data and may represent the injection of a new batch (or batches) of mantle-derived magma into the subvolcanic magma chamber. 26 refs., 4 figs., 2 tabs.

  1. Regolith production and transport in the Susquehanna Shale Hills Critical Zone Observatory, Part 1: Insights from U-series isotopes

    NASA Astrophysics Data System (ADS)

    Ma, Lin; Chabaux, Francois; West, Nikki; Kirby, Eric; Jin, Lixin; Brantley, Susan

    2013-06-01

    investigate the timescales of regolith formation on hillslopes with contrasting topographic aspect, we measured U-series isotopes in regolith profiles from two hillslopes (north facing versus south facing) within the east-west trending Shale Hills catchment in Pennsylvania. This catchment is developed entirely on the Fe-rich, Silurian Rose Hill gray shale. Hillslopes exhibit a topographic asymmetry: The north-facing hillslope has an average slope gradient of ~20°, slightly steeper than the south-facing hillslope (~15°). The regolith samples display significant U-series disequilibrium resulting from shale weathering. Based on the U-series data, the rates of regolith production on the two ridgetops are indistinguishable (40 ± 22 versus 45 ± 12 m/Ma). However, when downslope positions are compared, the regolith profiles on the south-facing hillslope are characterized by faster regolith production rates (50 ± 15 to 52 ± 15 m/Ma) and shorter durations of chemical weathering (12 ± 3 to 16 ± 5 ka) than those on the north-facing hillslope (17 ± 14 to 18 ± 13 m/Ma and 39 ± 20 to 43 ± 20 ka). The south-facing hillslope is also characterized by faster chemical weathering rates inferred from major element chemistry, despite lower extents of chemical depletion. These results are consistent with the influence of aspect on regolith formation at Shale Hills; we hypothesize that aspect affects such variables as temperature, moisture content, and evapotranspiration in the regolith zone, causing faster chemical weathering and regolith formation rates on the south-facing side of the catchment. The difference in microclimate between these two hillslopes is inferred to have been especially significant during the periglacial period that occurred at Shale Hills at least ~15 ka before present. At that time, the erosion rates may also have been different from those observed today, perhaps denuding the south-facing hillslope of regolith but not quite stripping the north-facing hillslope. An analysis of hillslope evolution and response timescales with a linear mass transport model shows that the current landscape at Shale Hills is not in geomorphologic steady state (i.e., so-called dynamic equilibrium) but rather is likely still responding to the climate shift from the Holocene periglacial to the modern, temperate conditions.

  2. Combined ESR/U-series chronology of Acheulian hominid-bearing layers at Trinchera Galería site, Atapuerca, Spain.

    PubMed

    Falguères, Christophe; Bahain, Jean-Jacques; Bischoff, James L; Pérez-González, Alfredo; Ortega, Ana Isabel; Ollé, Andreu; Quiles, Anita; Ghaleb, Bassam; Moreno, Davinia; Dolo, Jean-Michel; Shao, Qingfeng; Vallverdú, Josep; Carbonell, Eudald; Bermúdez de Castro, Jose María; Arsuaga, Juan Luis

    2013-08-01

    The Sierra de Atapuerca, northern Spain, is known from many prehistoric and palaeontological sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galería and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galería archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galería sites. The authors proposed for Galería an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (>530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galería site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350-450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galería and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data. PMID:23830175

  3. Combined ESR/U-series chronology of Acheulian hominid-bearing layers at Trinchera Galería site, Atapuerca, Spain

    USGS Publications Warehouse

    Falguères, Christophe; Bahain, Jean-Jacques; Bischoff, James L.; Pérez-González, Alfredo; Ortega, Ana Isabel; Ollé, Andreu; Quilles, Anita; Ghaleb, Bassam; Moreno, Davinia; Dolo, Jean-Michel; Shao, Qingfeng; Vallverdú, Josep; Carbonell, Eudald; María Bermúdez de Castro, Jose; Arsuaga, Juan Luis

    2013-01-01

    The Sierra de Atapuerca, northern Spain, is known from many prehistoric and palaeontological sites documenting human prehistory in Europe. Three major sites, Gran Dolina, Galería and Sima del Elefante, range in age from the oldest hominin of Western Europe dated to 1.1 to 1.3 Ma (millions of years ago) at Sima del Elefante to c.a. 0.2 Ma on the top of the Galería archaeological sequence. Recently, a chronology based on luminescence methods (Thermoluminescence [TL] and Infrared Stimulated Luminescence [IRSL]) applied to cave sediments was published for the Gran Dolina and Galería sites. The authors proposed for Galería an age of 450 ka (thousands of years ago) for the units lower GIII and GII, suggesting that the human occupation there is younger than the hominid remains of Sima de los Huesos (>530 ka) around 1 km away. In this paper, we present new results obtained by combined Electron Spin Resonance/Uranium-series (ESR/U-series) dating on 20 herbivorous teeth from different levels at the Galería site. They are in agreement with the TL results for the upper part of the stratigraphic sequence (GIV and GIIIb), in the range of between 200 and 250 ka. But for the GIIIa to GIIb levels, the TL ages become abruptly older by 200 ka while ESR ages remain relatively constant. Finally, the TL and ESR data agree in the lowest part of the section (GIIa); both fall in the range of around 350–450 ka. Our results suggest a different interpretation for the GII, GIII and GIV units of Galería and the upper part of Gran Dolina (TD10 and TD11) than obtained by TL. The ESR/U-series results are supported by a Bayesian analysis, which allows a better integration between stratigraphic information and radiometric data.

  4. Na, K, Ca, Mg, and U-series in fossil bone and the proposal of a radial diffusioneadsorption model of uranium uptake

    E-print Network

    Nacional de San Luis, Universidad

    Na, K, Ca, Mg, and U-series in fossil bone and the proposal of a radial diffusioneadsorption model Accepted 23 May 2014 Available online 20 June 2014 Keywords: Fossil bone Gamma-ray spectrometric U t Fossil bones are often the only materials available for chronological reconstruction of important archeo

  5. Dating "Dirty" Carbonates by U-series Isochrones: Insight Into Why Leaching Methods Don't Work

    NASA Astrophysics Data System (ADS)

    Zhang, Z.; Lundstrom, C.; Peng, Z.; Glessner, J.

    2007-12-01

    While accurate dating of "dirty" carbonates (carbonates having abundant detritus) using U-series methods would greatly impact the geochronology of difficult to date quaternary samples, robust methods are few in number. We set up a series of experiments using nearly pure carbonates (a calcitic stalagmite and a modern coral) that we physically mixed with variable amounts of USGS standard SDC-1 (mica schist representative of detritus). We dissolved each dirty carbonate mixture with acetic acid followed by leaching the residue with EDTA (to attempt to eliminate sorption). After completely dissolving the residue, the two solutions were spiked and measured for U- Th-Pa isotopes by MC-ICP-MS. Results show that significant amounts of 238U(235U), 234U and 232Th are removed from the mica schist despite the gentle dissolution. The concentrations of all nuclides in both solutions and residues show a linear relationship as a function of detritus/carbonate ratio. However, the linear relationship for isotope activity ratios, except (232Th/238U)A, is much weaker, especially for the residues. The migration direction of 231Pa and 230Th are consistently from the high concentration end member to the lower one; migration of these nuclides is not always the same direction as indicated by the long-lived isotopes (235U, 232Th). In summary, only total sample dissolution (TSD) methods can give an accurate age while leaching methods always are biased by nuclide migration out of the silicate detritus.

  6. Mantle Heterogeneity and Melting Along a Regional Axial Depth Gradient: Th-U Disequilibria Along the Southeast Indian Ridge

    NASA Astrophysics Data System (ADS)

    Russo, C. J.; Rubin, K. H.; Graham, D. W.

    2004-12-01

    Lateral variation in mantle temperature is generally considered to be the main cause for observed global correlations between regionally averaged mid-ocean ridge basalt (MORB) chemistry and ridge axis depth (Klein and Langmuir, 1987). Axial depth should be shallower above hotter mantle because the underlying mantle crosses its solidus at greater depth compared to cooler regions, and leads to greater crustal production. One expectation of this global model is that melting beneath ridges should involve progressively more (deep) garnet peridotite as ridge depth shallows. A negative correlation between (230Th/238U) and axial depth in a global dataset (largely dominated by eastern Pacific and Atlantic MORB) generally supports this notion, because garnet is known to fractionate Th from U during melting (Bourdon et al., 1996). The extent to which such global variations reflect only variations in melting conditions of passively upwelling mantle versus other conditions related to mantle heterogeneity or actively fed melting anomalies is presently unknown. To further address this question on the regional scale, we have measured Th-U isotopes on 11 basaltic glasses collected along the Southeast Indian Ridge (SEIR) from ˜90° E to ˜117° E. This ˜2600 km section of ridge is characterized by a west to east gradient in axial depth from ˜2300 m to >4500 m, similar to that of the global ridge system away from the influence of hotspots. However, unlike the global (230Th/238U)-axial depth correlation which uses regionally averaged data for ridge segments from a range of spreading rates, the SEIR is spreading at a nearly constant rate of 70-75 mm/yr and is devoid of large transform offsets. These first 11 SEIR glasses were selected to span the geographic range and to be representative of the elemental and isotopic compositions. Th and U concentrations range from 130-940 ppb and 55-267 ppb, respectively, with Th/U values ranging from 2.36 to 3.77. All samples show 230Th excesses, with (230Th/238U) ranging from 1.01 to 1.24. There is no correlation between (230Th/238U) and axial depth, in contrast to the simple prediction from the global scale model. On a (238U/232Th)-(230Th/232Th) equiline diagram the SEIR data form 3 geographical, non-collinear groupings: three basalts from the westernmost portion of our study area have the highest (230Th/232Th) and (238U/232Th), the easternmost basalt has significantly lower values, and basalts from a central region (101° E to 114° E) have intermediate values. The 7 central region basalts form a well-correlated positively sloping (230Th/232Th) vs. (238U/232Th) array which is shallower than the equiline and extends from 7% to 24% 230Th-excess. Overall, (230Th/232Th) shows a strong negative correlation with axial depth and, along with Th/U, correlates well with other isotopic tracers such as 3He/4He and 208Pb/206Pb, which vary systematically along axis. In contrast, (230Th/238U) shows no systematic variations with these isotopic parameters or axial depth. Unlike the global dataset, the Th-U disequilibria in SEIR MORB suggests that, at a regional scale, melting in the Indian Ocean mantle is primarily controlled by variations in mantle composition.

  7. Using U-series isotopes to quantify regolith formation and chemical weathering rates along a climosequence associated with the Susquehanna Shale Hills Critical Zone Observatory

    NASA Astrophysics Data System (ADS)

    Ma, L.; Chabaux, F. J.; Dere, A. L.; White, T.; Jin, L.; Brantley, S. L.

    2012-12-01

    Regolith formation and chemical weathering are important Critical Zone processes and are responsible for soil development. Despite their fundamental importance, we still lack effective tools to quantify these processes. U-series isotopes offer a powerful geochronometer to quantify regolith production rates and weathering duration. This is largely due to improvements in analytical methods and mathematical approaches made over the last decade in measuring U-series isotopes and interpreting their fractionation during chemical weathering. Here, we present a systematic study of U-series isotopes (238U, 234U and 230Th) in shale-derived soils from five small watersheds in the eastern USA to understand the rates of regolith formation as a function of climate. The selected watersheds in Pennsylvania, Virginia, Tennessee, Alabama, and Puerto Rico are part of the shale transect established as part of the Susquehanna Shale Hills Critical Zone Observatory. We first measured U-series isotopes in six regolith profiles from two planar hill-slopes (north vs. south) within the Shale Hills CZO in central PA to evaluate the role of aspect on regolith formation in the small watershed. All regolith samples display significant U-series disequilibrium. These U-series disequilibrium values are explained by two processes acting on U-series isotopes during weathering: a loss of 234U, 238U, and 230Th during water-rock interactions and a gain from circulating soil water and/or downslope particle transport. Regolith production rates and weathering durations were calculated with a U-series isotope mass balance model. On the southern (shaded) slope, regolith production rates decrease systematically with increasing soil thickness and distance from the ridge: from ~44.5 m/Myr at the ridge top to ~15.0 m/Myr at the valley floor. Durations of chemical weathering within these profiles range from 6.7 kyr to 44.7 kyr, increasing from the ridge to the valley floor. The regolith profiles on the northern (sun-facing) slope are characterized by faster regolith production rates (~40-52 m/Myr) and shorter durations of chemical weathering in the regolith zone (~12-16 kyr). These results reveal the important control of hill-slope aspect on the rate of regolith formation at Shale Hills: we hypothesize that aspect creates microclimates that in turn affect slope stability and erosion, and set different regolith residence times. The difference in microclimate is inferred to have been important before and during the periglacial period that occurred at Shale Hills ~15 ka. Our ongoing investigation of the four additional gray shale watersheds in VA, TN, AL, and PR provides information on shale weathering along a climosequence at a much larger continental scale. Only ridge top sites were selected to limit the aspect effect. This systematic study will enable us to quantitatively model regolith formation and landscape development on gray shales and to consider the effects of ongoing climate change.

  8. Measurement of radioactivity levels and assessment of radioactivity hazards of soil samples in Karaman, Turkey.

    PubMed

    Agar, O; Boztosun, I; Korkmaz, M E; Özmen, S F

    2014-12-01

    In this study, the levels of the natural and artificial radioactivity in soil samples collected from surrounding of Karaman in Turkey were measured. Activity concentrations of the concerned radionuclides were determined by gamma-ray spectrometry using a high-purity germanium detector with a relative efficiency of 40 % at 1.332 MeV. The results obtained for the (238)U series ((226)Ra, (214)Pb and (214)Bi), (232)Th series ((228)Ac), (40)K and fission product (137)Cs are discussed. To evaluate the radiological hazard of radioactivity in samples, the radium equivalent activity (Raeq), the absorbed dose rate (D), the annual effective dose and the external (Hex) and internal hazard index (Hin) were calculated and presented in comparison with the data collected from different areas in the world and Turkey. PMID:24587487

  9. Hydrological implications of 234U/238U disequilibria observed along pressure dissolution discontinuities in deep Mesozoic limestone formations of the Eastern Paris basin

    NASA Astrophysics Data System (ADS)

    Deschamps, P.; Hillaire-Marcel, C.; Michelot, J.; Doucelance, R.; Ghaleb, B.; Bushaert, S.

    2004-05-01

    Borehole core samples from the deep, low-permeability Mesozoic formations surrounding the target argilite layer of the Meuse/Haute-Marne experimental site of the French agency for nuclear waste management -ANDRA- were analyzed for their uranium isotopic abundance. This study attempts to decipher the history and the processes governing the mobility of uranium in such geological settings by means of precise measurements of the (234U/238U) activity ratio. Limestone zones characterized by pressure dissolution structures (stylolites or dissolution seams) display systematic (234U/238U) disequilibria: i) the material within the seams shows a deficit of 234U over 238U ((234U/238U) down to 0.80) and ii) the surrounding carbonate matrix is characterized by an activity ratio greater than unity (up to 1.05). These results highlight a discret, centimetric-scale uranium remobilization in the limestone formations along these sub-horizontal seams during the last 1-2 Ma and, consequently, active water/rock interaction processes since fractionation of 234U vs 238U necessary involves exchanges at the water/rock interface and migration via interstitial fluid. The nature and the modalities of the driving processes responsible for these disequilibria are not unequivocal, but different scenarios can be put forward to explain the U-remobilization observed: 1) late epidiagenetic processes associated to the presence of pressure dissolution structures, or 2) preferential fluid circulation along the stylolitic pathway. The major consequences in terms of the conceptual modeling of the hydrology behavior of the formations and, obviously, on the site performance assessment, are discussed.

  10. Properties of Natural Radiation and Radioactivity

    SciTech Connect

    Strom, Daniel J.

    2009-07-13

    Ubiquitous natural sources of radiation and radioactive material (naturally occurring radioactive material, NORM) have exposed humans throughout history. To these natural sources have been added technologically-enhanced naturally occurring radioactive material (TENORM) sources and human-made (anthropogenic) sources. This chapter describes the ubiquitous radiation sources that we call background, including primordial radionuclides such as 40K, 87Rb, the 232Th series, the 238U series, and the 235U series; cosmogenic radionuclides such as 3H and 14C; anthropogenic radionuclides such as 3H, 14C, 137Cs, 90Sr, and 129I; radiation from space; and radiation from technologically-enhanced concentrations of natural radionuclides, particularly the short-lived decay products of 222Rn ("radon") and 220Rn ("thoron") in indoor air. These sources produce radiation doses to people principally via external irradiation or internal irradiation following intakes by inhalation or ingestion. The effective doses from each are given, with a total of 3.11 mSv y-1 (311 mrem y-1) to the average US resident. Over 2.5 million US residents receive over 20 mSv y-1 (2 rem y-1), primarily due to indoor radon. Exposure to radiation from NORM and TENORM produces the largest fraction of ubiquitous background exposure to US residents, on the order of 2.78 mSv (278 mrem) or about 89%. This is roughly 45% of the average annual effective dose to a US resident of 6.2 mSv y-1 (620 mrem y-1) that includes medical (48%), consumer products and air travel (2%), and occupational and industrial (0.1%). Much of this chapter is based on National Council on Radiation Protection and Measurements (NCRP) Report No. 160, "Ionizing Radiation Exposure of the Population of the United States," for which the author chaired the subcommittee that wrote Chapter 3 on "Ubiquitous Background Radiation."

  11. 10Be and U-series dating of late Quaternary landforms along the southern San Jacinto fault: Implications for temporal slip rate variability

    NASA Astrophysics Data System (ADS)

    Blisniuk, K.; Oskin, M. E.; Fletcher, K.; Sharp, W. D.; Rockwell, T. K.

    2009-12-01

    Robust age control on faulted landforms with well-constrained offsets is essential to documenting the heterogeneous behavior of a fault zone over time. However, showing late Quaternary temporal slip rate variation is often challenging due to the difficultly of obtaining reliable ages for Quaternary deposits. Exposure ages from cosmogenic isotopes can be significantly affected by surface processes, and U-series dating of pedogenic carbonate provides only minimum ages because carbonate accumulation occurs after deposition. Fortunately, the controlling factors for the resulting age uncertainties of each method are relatively independent from each other, so a combination of cosmogenic isotope and U-series dating may significantly improve the reliability of landform dating and yield more robust slip rate estimates. We present preliminary results of this dual-dating approach at 4 sites along the southern San Jacinto fault zone in California: 2 sites along the Coyote Creek fault, and 2 sites along the Clark fault. These results show age agreement between the two dating methods. Along the southern Clark fault, a 10Be depth profile model age of 34.5 ±6.6 ka and a U-series age of 33.2 ±1.1 ka were obtained for an offset Q2b fan surface, and a Q3b surface yielded a weighted mean 10Be surface exposure age of 5.9 ±1.5 ka, similar to an U-series age of 6.3 ±0.4 ka. Along the northern Coyote Creek fault, preliminary data indicate a 10Be surface exposure age of 11.3 ±3.4 ka and a U-series age of 11.7 ±1.8 ka for an offset Q3a surface, and a 10Be surface exposure age of 6.9 ±1.0 ka and a U-series age of 7.8 ± 0.9 ka for an offset Q3b surface. The remarkable consistency among ages from the two dating methods suggest that: (1) U-series ages of pedogenic carbonate clast rinds closely approach depositional ages of the host alluvium; (2) erosion may be negligible at the sampled sites; and (3) inherited 10Be has been accurately quantified (via depth profile) for the late Pleistocene deposits, and is negligible for Holocene fans. In general, our results show that, in an arid setting where post-depositional processes are limited and multiple dating techniques can be applied, reliable ages may be obtained to yield robust slip rates across and along fault zones. Preliminary slip-rate results from these sites imply that slip rates may have varied significantly over the late Quaternary, with an ~2x increase since ~8-6 kyr.

  12. U-series dates on travertine deposits in the Great Artesian Basin as paleohydrogeology and neotectonic indicators

    NASA Astrophysics Data System (ADS)

    Priestley, S.; Karlstrom, K. E.; Crossey, L. J.; Love, A.; Polyak, V.; Asmerom, Y.; Embid, E.

    2010-12-01

    Travertine deposits of the western Great Artesian Basin (GAB) are associated with mound springs (many still active) and form calcium carbonate precipitates due to CO2 degassing as the highly carbonated groundwaters emerge along faults. They collectively, provide a record that can be used to link the present hydrogeological system to the paleohydrogeology of the GAB. The GAB is a very large artesian sedimentary basin which contains groundwater that has evolved over hundreds of thousands to millions of years. Although the equipotential surface has declined since development of the aquifer, anthropogenic draw down is superimposed on less well understood transient effects due to paleoclimate cycles which requires better understanding of the flow paths and paleohydrologic fluctuations in the GAB. Travertines can provide proxy data to understand the relative magnitude and chronology of spring discharge through time, which will aid in the development of a transient conceptual groundwater model of the system. The travertine deposits also provide underutilized and sensitive gauges of neotectonics in Australia, generally thought of as one of the oldest, flattest, and least tectonically active of the continents, but one that is neotectonically active in the western GAB area. U-Series dates provide age constraints on travertine deposition. Travertines at Dalhousie Springs range from 687 ± 228 ka to 163 ± 7 ka. Travertines along the mound springs line range from 372 ± 14 ka (Beresford extinct mound) to 0.12 ± 0.001 ka (Sulfur spring). The dates indicate persistent deposition at discrete spring vents over at least 700 thousand years. Our hypothesis is that times of largest travertine accumulations (10 - 20 ka, 120 ka, 250 ka, and 350 - 400 ka) may have corresponded to wetter times. Stable isotope analyses of the dated travertines reveals that spring groups have different carbon isotope values that vary by 4 - 6 per mil in O, reflecting local spring chemistry and/or paleoclimate variations. These results demonstrate that the extensive travertine deposits can be used to develop a paleohydrogeology record at both 100 ka and 10 - 1 ka time scales for comparison with other paleoclimate proxies. Mound spring discharge is aligned along faults that parallel lithosopheric zones of weakness along the Tasman line and Torrens hinge zone, these separate the actively uplifting Flinders and Dennison Ranges from subsiding Lake Eyre region. An age of 372 ± 14 ka from the elevated extinct Beresford mound indicates bedrock denudation rates of the Bulldog shale surface of 67 m/Ma that are likely driven by neotectonics. More comprehensive dating may show differential uplift depending on position relative to uplifting versus subsiding domains on either side of the mound springs line. Collectively, the lowest elevations in the Australian continent, the mound springs lineaments, and the resulting locations of the main discharge areas of the GAB are seen as a product of different interacting scales of active tectonism in central Australia.

  13. Radioactive Wastes.

    PubMed

    Choudri, B S; Baawain, Mahad

    2015-10-01

    Papers reviewed herein present a general overview of radioactive waste activities around the world in 2014. These include safety assessments, decommission and decontamination of nuclear facilities, fusion facilities, transportation and management solutions for the final disposal of low and high level radioactive wastes (LLW and HLW), interim storage and final disposal options for spent fuel (SF), and tritiated wastes, with a focus on environmental impacts due to the mobility of radionuclides in water, soil and ecosystem alongwith other progress made in the management of radioactive wastes. PMID:26420096

  14. Concentrating Radioactivity

    ERIC Educational Resources Information Center

    Herrmann, Richard A.

    1974-01-01

    By concentrating radioactivity contained on luminous dials, a teacher can make a high reading source for classroom experiments on radiation. The preparation of the source and its uses are described. (DT)

  15. Radioactivity Calculations

    ERIC Educational Resources Information Center

    Onega, Ronald J.

    1969-01-01

    Three problems in radioactive buildup and decay are presented and solved. Matrix algebra is used to solve the second problem. The third problem deals with flux depression and is solved by the use of differential equations. (LC)

  16. Simulated Radioactivity

    ERIC Educational Resources Information Center

    Boettler, James L.

    1972-01-01

    Describes the errors in the sugar-cube experiment related to radioactivity as described in Project Physics course. The discussion considers some of the steps overlooked in the experiment and generalizes the theory beyond the sugar-cube stage. (PS)

  17. Radioactive Iodine

    MedlinePLUS

    ... form of iodide, is made into two radioactive isotopes that are commonly used in patients with thyroid ... thyroid cells ). The radiation emitted by each these isotopes can be detected from outside the patient to ...

  18. Mass spectrometric U-series dating of Huanglong Cave in Hubei Province, Central China: evidence for early presence of modern humans in Eastern Asia.

    PubMed

    Shen, Guanjun; Wu, Xianzhu; Wang, Qian; Tu, Hua; Feng, Yue-xing; Zhao, Jian-xin

    2013-08-01

    Most researchers believe that anatomically modern humans (AMH) first appeared in Africa 160-190 ka ago, and would not have reached eastern Asia until ?50 ka ago. However, the credibility of these scenarios might have been compromised by a largely inaccurate and compressed chronological framework previously established for hominin fossils found in China. Recently there has been a growing body of evidence indicating the possible presence of AMH in eastern Asia ca. 100 ka ago or even earlier. Here we report high-precision mass spectrometric U-series dating of intercalated flowstone samples from Huanglong Cave, a recently discovered Late Pleistocene hominin site in northern Hubei Province, central China. Systematic excavations there have led to the in situ discovery of seven hominin teeth and dozens of stone and bone artifacts. The U-series dates on localized thin flowstone formations bracket the hominin specimens between 81 and 101 ka, currently the most narrow time span for all AMH beyond 45 ka in China, if the assignment of the hominin teeth to modern Homo sapiens holds. Alternatively this study provides further evidence for the early presence of an AMH morphology in China, through either independent evolution of local archaic populations or their assimilation with incoming AMH. Along with recent dating results for hominin samples from Homo erectus to AMH, a new extended and continuous timeline for Chinese hominin fossils is taking shape, which warrants a reconstruction of human evolution, especially the origins of modern humans in eastern Asia. PMID:23870460

  19. Growth of north-east Atlantic cold-water coral reefs and mounds during the Holocene: A high resolution U-series and 14C chronology

    NASA Astrophysics Data System (ADS)

    Douarin, Mélanie; Elliot, Mary; Noble, Stephen R.; Sinclair, Daniel; Henry, Lea-Anne; Long, David; Moreton, Steven G.; Murray Roberts, J.

    2013-08-01

    We investigated the Holocene growth history of the Mingulay Reef Complex, a seascape of inshore cold-water coral reefs off western Scotland, using U-series and radiocarbon dating methods. Both chronologies revealed episodic occurrences of the reef framework-forming scleractinian coral Lophelia pertusa during the late Holocene. Downcore U-series dating revealed unprecedented reef growth rates of up to 12 mm a-1 with a mean rate of 3-4 mm a-1. Our study highlighted a persistent hiatus in coral occurrence from 1.4 ka to modern times despite present day conditions being conducive for coral growth. The growth history of the complex was punctuated at least twice by periods of reduced growth rates: 1.75-2.8 ka, 3.2-3.6 ka and to a lesser extent at 3.8-4 ka and at 4.2 ka. Timing of coral hiatuses and reduced reef growth rates at Mingulay were synchronous with those occurring across the wider northern European region, which suggests a close relationship between these ecosystems and large-scale shifts in palaeoenvironmental regimes associated with changes to the North Atlantic subpolar gyre.

  20. Long-term slip rates of the Elsinore-Laguna Salada fault, southern California, by U-series Dating of Pedogenic Carbonate in Progressively Offset Alluvial fan Remnants.

    NASA Astrophysics Data System (ADS)

    Fletcher, K. E.; Rockwell, T. K.; Sharp, W. D.

    2007-12-01

    The Elsinore-Laguna Salada (ELS) fault is one of the principal strands of the San Andreas fault system in southern California, however its seismic potential is often de-emphasized due to previous estimates of a low slip rate. Nevertheless, the fault zone has produced two historic earthquakes over M6, with the 1892 event estimated at >M7; thus further investigation of the long-term slip rate on the ELS fault is warranted. On the western slopes of the Coyote Mountains (CM), southwest Imperial Valley, a series of alluvial fans are progressively offset by the Elsinore fault. These fans can be correlated to their source drainages via distinctive clast assemblages, thereby defining measurable offsets on the fault. Dating of the CM fans (to compute slip rates), however, is challenging. Organic materials appropriate for C-14 dating are rare or absent in the arid, oxidizing environment. Cosmogenic surface exposure techniques are limited by the absence of suitable sample materials and are inapplicable to numerous buried fan remnants that are otherwise excellent strain markers. Pedogenic carbonate datable by U-series, however, occurs in CM soil profiles, ubiquitously developed in fan gravels, and is apparent in deposits as young as ~1 ka. In CM gravels 10's ka and older, carbonate forms continuous, dense, yellow coatings up to 3 mm thick on the undersides of clasts. Powdery white carbonate may completely engulf clasts, but is not dateable. Carefully selected samples of dense, innermost carbonate lamina weighing 10's of milligrams and analyzed by TIMS, are geochemically favorable for precise U-series dating (e.g., U = 1-1.5 ppm, median 238U/232Th ~ 7), and yield reproducible ages for coatings from the same microstratigraphic horizon (e.g., 48.2 ± 2.7 and 49.9 ± 2.2 ka), indicating that U-Th systems have remained closed and that inherited coatings, though present, have been avoided. Accordingly, U-series on pedogenic carbonate provides reliable minimum ages for deposition of host landforms, thereby facilitating determination of maximum bounds on corresponding slip rates. Results to date show that pedogenic carbonate dating in the CM has a useful range of at least 140 ka, thus progressively offset geomorphic surfaces in the CM study area afford the opportunity to examine the pattern of slip on the Elsinore fault over time scales from circa 10 to >100 ka.

  1. Radioactive wastes

    SciTech Connect

    Devarakonda, M.S.; Hickox, J.A.

    1996-11-01

    This paper provides a review of literature published in 1995 on the subject of radioactive wastes. Topics covered include: national programs; waste repositories; mixed wastes; decontamination and decommissioning; remedial actions and treatment; and environmental occurrence and transport of radionuclides. 155 refs.

  2. Radioactive Waste.

    ERIC Educational Resources Information Center

    Blaylock, B. G.

    1978-01-01

    Presents a literature review of radioactive waste disposal, covering publications of 1976-77. Some of the studies included are: (1) high-level and long-lived wastes, and (2) release and burial of low-level wastes. A list of 42 references is also presented. (HM)

  3. The chronology of hand stencils in European Palaeolithic rock art: implications of new U-series results from El Castillo Cave (Cantabria, Spain).

    PubMed

    García-Diez, Marcos; Garrido, Daniel; Hoffmann, Dirk; Pettitt, Paul; Pike, Alistair; Zilhão, Joao

    2015-07-20

    The hand stencils of European Paleolithic art tend to be considered of pre-Magdalenian age and scholars have generally assigned them to the Gravettian period. At El Castillo Cave, application of U-series dating to calcite accretions has established a minimum age of 37,290 years for underlying red hand stencils, implying execution in the earlier part of the Aurignacian if not beforehand. Together with the series of red disks, one of which has a minimum age of 40,800 years, these motifs lie at the base of the El Castillo parietal stratigraphy. The similarity in technique and colour support the notion that both kinds of artistic manifestations are synchronic and define an initial, non-figurative phase of European cave art. However, available data indicate that hand stencils continued to be painted subsequently. Currently, the youngest, reliably dated examples fall in the Late Gravettian, approximately 27,000 years ago. PMID:25615428

  4. Radioactivity in PffP Radioactivity

    E-print Network

    Browder, Tom

    Radioactivity in PffP #12;Radioactivity Historically, classified into three types Alpha rays for some radioactive decays) Is decay mediated by a strong, weak or EM interaction ? Quick review(?) of decay Visualization A fundamental process underlying many types of radioactivity #12;Fundamental

  5. U-series disequilibrium in rear-arc volcanoes from the Northern Volcanic Zone in Ecuador; along-arc variation and implications for petrogenetic processes

    NASA Astrophysics Data System (ADS)

    Garrison, J. M.; Matthews, T. P.; Sims, K. W.; Escobar, R. D.; Yogodzinski, G. M.; Waters, C. L.

    2012-12-01

    Ecuador has been the focus of several studies that document the across-arc geochemical variation in the Northern Volcanic Zone (NVZ), and these studies have been useful in illustrating that from west to east, the lavas are higher in alkali and the fluid mobile elements. Of less focus has been the north to south along-arc variation that is illustrated by volcanoes including Sumaco, Pan de Azucar and El Reventador. Reventador is the northernmost volcano in the rear-arc of the NVZ and has been active since a renewed cycle of activity began in November 2002. Sumaco is located 30 km to the south and has been inactive since at least 1933, although no historic eruptions have been recorded for this volcano. Located between these two volcanoes is the inactive Pan de Azucar volcano, for which there exists no data on the eruptive history. The goal of this research is to document changes in geochemical variation from north to south in the rear-arc of Ecuador and to link this to a petrogenetic process or processes. During a 2010 expedition we collected samples from Sumaco and Reventador Volcanoes, and obtained samples from Pan de Azucar volcano from our colleagues at the IGEPN in Quito. Samples were analyzed for U-series isotopes in addition to major and trace elements. In terms of major and trace elements, El Reventador lavas are weakly alkaline and contain plagioclase, pyroxene and olivine as the major phases, whereas the Sumaco lavas are strongly alkaline and contain titanian augite and hauyne as major phases. The Pan de Azucar samples are compositionally intermediate between the two. Generally speaking, from north to south Ba/Nb decreases from a maximum of 150 at Reventador to 50 at Sumaco, whereas the La/Yb increases from 30 to 50. Other systematic N-S changes include decreasing Ba/Th, which is negatively correlated with Sr concentrations that range from 1000 (Reventador) to 4000 (Sumaco). This is consistent with lower fluid input from N-S that generates smaller degrees of melting. The U-series data give conflicting results, the highest (238U/230Th) values are at Sumaco, and range from 0.87 to 1.7. The majority of samples have 238U excesses of up to 70% with the exception of the most evolved samples, which have 230Th excesses of 15%. The Reventador samples, on the other hand have much lower 238U excesses of up to only 10% and (238U/230Th) values that range from 0.87 - 1.1. Higher 238U excesses are typically thought to reflect higher fluid input, however the trace element data are consistent with higher fluid input at Reventador, not Sumaco. One possible explanation for this is that the 238U excesses at Sumaco are primarily due to differentiation of minerals that sequester Th, perhaps apatite. The (238U/230Th) of the Sumaco lavas is highly correlated differentiation indexes like La/Yb, MgO and P2O5, whereas the Reventador samples show a much weaker correlation. We conclude that there is a systematic trend showing decreasing H2O input from north to south in the rear arc of the NVZ, and that the U-series data reveal differences in differentiation processes.

  6. Using U-series Isotopes To Determine Sources Of Pedogenic Carbonates: Comparison Of Natural And Agricultural Soils In The Semi-arid Southern New Mexico And Western Texas

    NASA Astrophysics Data System (ADS)

    Nyachoti, S. K.; Ma, L.; Borrok, D. M.; Jin, L.; Tweedie, C. E.

    2012-12-01

    Pedogenic carbonates commonly precipitate from infiltrating soil water in arid and semi-arid lands and are observed in soils of southern New Mexico and western Texas. These carbonates could form an impermeable layer in the soil horizons impairing water infiltration, thus affecting crop growth and yield. It is important to determine the source of C and Ca in these carbonates and to understand conditions favoring their formation, kinetics and precipitation rates. In this study, major elements and U-series isotopes in bulk calcic soils, and weak acid leachates and residues were measured from one irrigated alfalfa site in the Hueco basin near El Paso, TX and one natural shrubland site on the USDA Jornada experimental range in southern NM. The combined geochemical and isotopic results allow us to determine the formation ages of the carbonates; investigate the mobility of U, Th, and major elements in these soils; and infer for the effects of irrigation on carbonate formation in agricultural soils. Our results show distinctive U and Th isotope systems in the two soil profiles analyzed. For example, (234U/238U) ratios in the Jornada bulk soils decrease from ~1.01 to 0.96 towards the surface, consistent with a preferential loss of 234U over 238U during chemical weathering. At the Jornada site, (238U/232Th) ratios decrease while (230Th/238U) increase towards the surface, consistent with a general depletion of U and the immobility of Th in the natural soils. By contrast at the Alfalfa site, (234U/238U) ratios of bulk soils increase from ~ 0.97 to 1.02 towards the surface, suggesting an additional source of external uranium, most likely the irrigation water from Rio Grande which has a (234U/238U) ratio of ~ 1.5 near El Paso. The (238U/232Th) and (230Th/238U) ratios also imply leaching of U from shallower soils but precipitation in greater depths at Alfalfa site; suggests that partial dissolution and re-precipitation of younger carbonates occur. Calculated carbonate ages from U-series isotopes at the natural Jornada site range from 15.7±0.1 to 36.9±0.1kyrs. Near the surface these carbonates are older but at depth, relatively young carbonates indicate partial weathering and overprinting over older carbonates. However, much younger carbonate ages (2.1±0.2 to 21±0.1kyrs) are observed at the Alfalfa site. These ages generally decrease with increasing depth with the youngest carbonate ages (2.1±0.2 kyrs) at ~52 cm. The trend depicted represents a mixture of newly-formed carbonates due to irrigation and pre-existing much older natural carbonates in soils. Evidently young carbonates in the agricultural soils indicate that calcite precipitates out of saline irrigation water. An additional profile is noted with MgO at the Alfalfa site and suggests that Mg2+ is added onto these soils probably from irrigation waters. However at the Jornada site, low MgO contents near the surface indicate loss of Mg most likely by leaching and plant uptake. Our case study highlights the use of U-series and major elements to understand the formation processes of carbonates in both agricultural and natural soils. Clearly, the high salinity of Rio Grande water contributes to elevated amounts of carbonates in agricultural farms and this flux might be important for the overall global mass balance of carbon.

  7. Levels of sup 137 Cs and natural radioactivity in Saudi Arabian soil

    SciTech Connect

    Abulfarai, W.; Abdul-Majid, S. )

    1991-01-01

    After the Chernobyl accident, there was concern about contamination from the radioactive plume reaching Saudi Arabia. Cesium-137 concentration in the soil was measured to determine the degree of contamination from the accident. The concentrations of {sup 40}K, {sup 214}Bi, and {sup 228}Ac were determined as well. Bismuth-214 is a member of the {sup 238}U series, while {sup 228}Ac is from the {sup 238}Th series. Each of these isotopes emits several well-resolved photons of relatively high intensity per disintegration.

  8. Radioactivity in local and imported kaolin types used in Egypt.

    PubMed

    el-Dine, N Walley; Sroor, A; el-Shershaby, A; el-Bahi, S M; Ahmed, F

    2004-01-01

    Natural radioactive materials are present in all geological rocks in varying amounts, they are easily mobilized in the environment, and can reach hazardous radiological levels under certain conditions, requiring precautions to be taken. The present study deals with 50 geological samples of local (Tushki and Kalabsha in upper Egypt) and imported (southeast Asia and Turkey) kaolin types. The samples were analyzed by gamma-ray spectroscopy using a HPGe detector. The activity concentrations of 232Th and 238U series and 40K and the contents (in ppm) are given. The radium equivalent activity varied from 187.8 to 10185.19 Bq/kg. 137Cs was found in a range of 0.23-8.5 Bq/kg, for the local samples. The kaolin in Tushki area was suitable for industrial use. PMID:14687643

  9. Beryllium Isotope and Combined Be and U-series Isotope Studies of Volcanic Arcs: Implications for Fluid and Melt Transport Through the Mantle Wedge

    NASA Astrophysics Data System (ADS)

    Morris, J. D.; Ryan, J. G.

    2004-12-01

    Beryllium isotope and combined studies of 10Be/9Be and U-series isotopes in volcanic arcs can 1) map transport of demonstrably slab derived elements through the mantle wedge; 2) certify the relationship of U series isotopes to slab derivation; 3) identify multiple stages in subduction modification of the mantle and constrain their timescales; and 4) speak to element partitioning into fluids and melts from the slab. In the Kurile, Aleutian and Bismarck arcs, 10Be/9Be ratios for lavas from behind the volcanic front are often comparable to, and sometimes greater than, those at the volcanic front, despite the longer path to rear-arc locations, along which 10Be is decaying in transit. Be/Zr ratios show a similar pattern of across-arc increase, without increases in enrichments of Mo and Sn, species which would be mobilized with Be if F-bearing fluids were present. The simplest interpretation is that sediment melting, and its contribution to the mantle wedge, is greater behind the front than at the volcanic front. Despite evidence for an increasing sediment melt contribution behind the front, volcanoes from the Kuriles contain progressively less B, Pb, As and Sb with increasing depth to the slab, indicating that fluid processes updip of about 180 km (beginning in the shallow forearc) strip these elements nearly quantitatively from the sedimentary portion of the downgoing slab. For studies published to date (Aleutians, Central America, S. Chile, Bismarck, Mariana) 10Be/9Be ratios are generally highest for samples plotting furthest from the 238U-230Th equiline (i.e. highest 238U/232Th, 230Th/232Th, or both). In lavas from the Southern Volcanic Zone (SVZ) of S. Chile (Sigmarsson et al., EPSL 2002), U excess (Uxs), Ra excess (Raxs) and 10Be/9Be are strongly correlated (r2=0.81-0.94). This argues that U enrichment and in some cases Ra enrichment in arc lavas is related to slab processes that are capable of mobilizing 10Be out of the sediment column, rather than reflecting only dynamic melting processes or element partitioning in a hydrous mantle wedge. If U and Ra are thought to be carried in a fluid from the altered oceanic crust, that fluid must also carry sediment-derived elements, at least in the SVZ. In Nicaragua, the Aleutians and S. Chile, volcano 10Be/9Be ratios correlate well with 230Th/232Th, 143Nd/144Nd and Uxs and Raxs, respectively. The well constrained mixing lines require that both the subducted component and the mantle to which it is added be relatively homogenous for these slab-derived tracers. At zero 10Be (i.e. prior to sediment addition within the last 1-2 Ma), the Nicaraguan mantle is characterized by high Ba/La, 87Sr/86Sr and 230Th/232Th significantly elevated above MORB or OIB values, attributed to earlier subduction modification of the mantle (Reagan et al., GCA 1994). In the SVZ of Southern Chile, at zero 10Be, the 230Th/232Th of the inferred mantle source is ~0.9, implying sediment addition prior to the more recent event that introduced 10Be. By contrast, at zero 10Be, the inferred Aleutian mantle has a 143Nd/144Nd ratio of ˜ 0.5131, suggesting little or no prior sediment addition to the mantle.

  10. U-series isotope systematics of mafic magmas from central Oregon: Implications for fluid involvement and melting processes in the Cascade arc

    NASA Astrophysics Data System (ADS)

    Mitchell, Euan C.; Asmerom, Yemane

    2011-12-01

    The Cascade arc is the warm-slab subduction zone global end member, where a broad variety of primitive magmas with highly variable slab fluid signatures have erupted in close spatial and temporal proximity. A number of petrogenetic models have been proposed to explain the occurrence of such diverse magmas, but the source(s) of these magmas and the timing of fluid addition to the sub-arc mantle remain controversial. We present uranium-series isotope data ( 238U- 230Th- 226Ra) for eighteen mafic lavas from the Three Sisters region of the central Oregon Cascades, and for a further six lavas from the rear-arc Newberry Volcano. The majority of these samples have geochemical characteristics (e.g. Nb/Zr, Ba/Zr, 87Sr/ 86Sr) consistent with previously described calc-alkaline basalts from this region of the arc, and indicative of limited fluid involvement at some stage in their genesis. Trace element and long-lived radiogenic isotope modeling suggests that this fluid was derived from dehydration of subducting sediments, and was added to an enriched, garnet-bearing mantle wedge source. The trace element systematics of the lavas are consistent with small degree (< 10%) melts of this fluid-modified source. All samples display ( 230Th/ 238U) and ( 226Ra/ 230Th) ? 1, similar to values measured in fresh MORB and other parts of the arc. Results of a dynamic melting model support the interpretation that these lavas are small degree melts of an asthenospheric source, and do not allow for a lithospheric mantle source. However, the U-series data do not permit us to determine whether fluid addition was the trigger for melting, or whether the lavas were generated from a secular equilibrium source that had experienced fluid addition > 350 ka prior to melting. Regardless, modern fluid input is limited and melting is dominantly occurring in response to upwelling and decompression.

  11. Origins of large-volume, compositionally zoned volcanic eruptions: New constraints from U-series isotopes and numerical thermal modeling for the 1912 Katmai-Novarupta eruption

    USGS Publications Warehouse

    Turner, Simon; Sandiford, Mike; Reagan, Mark; Hawkesworth, Chris; Hildreth, Wes

    2010-01-01

    We present the results of a combined U-series isotope and numerical modeling study of the 1912 Katmai-Novarupta eruption in Alaska. A stratigraphically constrained set of samples have compositions that range from basalt through basaltic andesite, andesite, dacite, and rhyolite. The major and trace element range can be modeled by 80–90% closed-system crystal fractionation over a temperature interval from 1279°C to 719°C at 100 MPa, with an implied volume of parental basalt of ?65 km3. Numerical models suggest, for wall rock temperatures appropriate to this depth, that 90% of this volume of magma would cool and crystallize over this temperature interval within a few tens of kiloyears. However, the range in 87Sr/86Sr, (230Th/238U), and (226Ra/230Th) requires open-system processes. Assimilation of the host sediments can replicate the range of Sr isotopes. The variation of (226Ra/230Th) ratios in the basalt to andesite compositional range requires that these were generated less than several thousand years before eruption. Residence times for dacites are close to 8000 years, whereas the rhyolites appear to be 50–200 kyr old. Thus, the magmas that erupted within only 60 h had a wide range of crustal residence times. Nevertheless, they were emplaced in the same thermal regime and evolved along similar liquid lines of descent from parental magmas with similar compositions. The system was built progressively with multiple inputs providing both mass and heat, some of which led to thawing of older silicic material that provided much of the rhyolite.

  12. On the Quality of ENSDF {gamma}-Ray Intensity Data for {gamma}-Ray Spectrometric Determination of Th and U and Their Decay Series Disequilibria, in the Assessment of the Radiation Dose Rate in Luminescence Dating of Sediments

    SciTech Connect

    Corte, Frans de; Vandenberghe, Dimitri; Wispelaere, Antoine de

    2005-05-24

    In luminescence dating of sediments, one of the most interesting tools for the determination of the annual radiation dose is Ge {gamma}-ray spectrometry. Indeed, it yields information on both the content of the radioelements K, Th, and U, and on the occurrence - in geological times - of disequilibria in the Th and U decay series. In the present work, two methodological variants of the {gamma}-spectrometric analysis were tested, which largely depend on the quality of the nuclear decay data involved: (1) a parametric calibration of the sediment measurements, and (2) the correction for the heavy spectral interference of the 226Ra 186.2 keV peak by 235U at 185.7 keV. The performance of these methods was examined via the analysis of three Certified Reference Materials, with the introduction of {gamma}-ray intensity data originating from ENSDF. Relevant conclusions were drawn as to the accuracy of the data and their uncertainties quoted.

  13. Radioactive iodine uptake

    MedlinePLUS

    ... the testing center so that the amount of radioactivity in the thyroid gland can be measured. This ... The amount of radioactivity is very small, and there have been no documented side effects. The amount of iodine used is less than ...

  14. Procedures for radioactive I-131

    SciTech Connect

    Sharma, S.C. )

    1988-12-01

    Details of the radioactive I-131 administration and radiation safety considerations are presented. Topics covered include patient survey, radioactive labelling, levels in patients containing radioactivity, hospital discharge of radioactive patients, and nursing procedures.

  15. ORNL radioactive waste operations

    SciTech Connect

    Sease, J.D.; King, E.M.; Coobs, J.H.; Row, T.H.

    1982-01-01

    Since its beginning in 1943, ORNL has generated large amounts of solid, liquid, and gaseous radioactive waste material as a by-product of the basic research and development work carried out at the laboratory. The waste system at ORNL has been continually modified and updated to keep pace with the changing release requirements for radioactive wastes. Major upgrading projects are currently in progress. The operating record of ORNL waste operation has been excellent over many years. Recent surveillance of radioactivity in the Oak Ridge environs indicates that atmospheric concentrations of radioactivity were not significantly different from other areas in East Tennesseee. Concentrations of radioactivity in the Clinch River and in fish collected from the river were less than 4% of the permissible concentration and intake guides for individuals in the offsite environment. While some radioactivity was released to the environment from plant operations, the concentrations in all of the media sampled were well below established standards.

  16. Radioactivity and food

    SciTech Connect

    Olszyna-Marzys, A.E. )

    1990-03-01

    Two topics relating to radioactivity and food are discussed: food irradiation for preservation purposes, and food contamination from radioactive substances. Food irradiation involves the use of electromagnetic energy (x and gamma rays) emitted by radioactive substances or produced by machine in order to destroy the insects and microorganisms present and prevent germination. The sanitary and economic advantages of treating food in this way are discussed. Numerous studies have confirmed that under strictly controlled conditions no undesirable changes take place in food that has been irradiated nor is radioactivity induced. Reference is made to the accident at the Chernobyl nuclear power station, which aroused public concern about irradiated food. The events surrounding the accident are reviewed, and its consequences with regard to contamination of different foods with radioactive substances, particularly iodine-131 and cesium-137, are described. Also discussed are the steps that have been taken by different international organizations to set limits on acceptable radioactivity in food.15 references.

  17. Porosity of the melting zone and variations in the solid mantle upwelling rate beneath Hawaii: Inferences from {sup 238}U-{sup 230}Th-{sup 226}Ra and {sup 235}U-{sup 231}Pa disequilibria

    SciTech Connect

    Sims, K.W.W.; DePaolo, D.J.; Murrell, M.T.; Baldridge, W.S.; Goldstein, S.; Clague, D.; Jull, M.

    1999-12-01

    Measurements of {sup 238}U-{sup 230}Th-{sup 226}Ra and {sup 235}U-{sup 231}Pa disequilibria in a suite of tholeiitic-to-basanitic lavas provide estimates of porosity, solid mantle upwelling rate and melt transport times beneath Hawaii. The observation that ({sup 230}Th/{sup 238}U) {gt} 1 indicates that garnet is required as a residual phase in the magma sources for all of the lavas. Both chromatographic porous flow and dynamic melting of a garnet peridotite source can adequately explain the combined U-Th-Ra and U-Pa data for these Hawaiian basalts. For chromatographic porous flow, the calculated maximum porosity in the melting zone ranges from 0.3--3% for tholeiites and 0.1--1% for alkali basalts and basanites, and solid mantle upwelling rates range from 40 to 100 cm/yr for tholeiites and from 1 to 3 cm/yr for basanites. For dynamic melting, the escape or threshold porosity is 0.5--2% for tholeiites and 0.1--0.8% for alkali basalts and basanites, and solid mantle upwelling rates range from 10 to 30 cm/yr for tholeiites and from 0.1 to 1 cm/yr for basanites. Assuming a constant melt productivity, calculated total melt fractions range from 15% for the tholeiitic basalts to 3% for alkali basalts and basanites.

  18. Rapid Ascent of Aphyric Mantle Melts through the Overriding Crust in Subduction Zones: Evidence from Variable Uranium-Series Disequilibria, Amorphous Hydrous Alteration Microtextures in Crystal Rims, and Two-Pyroxene Pseudo-Decompression Paths

    NASA Astrophysics Data System (ADS)

    Zellmer, G. F.; Freymuth, H.; Hsieh, H. H.; Hwang, S. L.; Iizuka, Y.; Miller, C. A.; Rubin, K. H.; Sakamoto, N.; Yurimoto, H.

    2014-12-01

    Volcanic hazard mitigation at subduction zones critically depends on knowledge of magma generation and ascent processes and timescales. Two diametrically opposite scenarios are presently debated: One paradigm is the generation of low-silica (basaltic) melts in the mantle wedge, followed by protracted sub-liquidus magma ascent and evolution through crystal growth and fractionation in crustal reservoirs, which are tapped during volcanic eruptions. In contrast, a diametrically opposite model favours the generation of higher silica melts in the mantle or in a lower crustal hot zone, followed by rapid decompression to the surface under super-liquidus conditions. In the latter case, crystals are picked up during magma ascent, and are in the process of dissolving. We present multiple lines of evidence that point to crystal uptake as the principal processes by which arc melts acquire their crystal cargo: (i) variable 234U-238U disequilibria in mineral separates; (ii) hydrous mineral rims with amorphous alteration textures; and (iii) two-pyroxene pseudo-decompression paths; cf. Zellmer et al. (2014a,b,c), doi: 10.1144/SP385.3 and 10.1144/SP385.9 and 10.1144/SP410.1. These observations point to a scarcity of true phenocrysts in many arc magmas, and thus to decompression of aphyric melts that take up their crystal cargo during ascent. The data imply that many hydrous wedge melts are more silica-rich than basalts and achieve super-liquidus conditions during rapid ascent from great depth.

  19. Radioactive Waste: 1. Radioactive waste from your lab is

    E-print Network

    Lance, Veronica P.

    Radioactive Waste: 1. Radioactive waste from your lab is collected by the RSO. 2. Dry radioactive waste must be segregated by isotope. 3. Liquid radioactive waste must be separated by isotope. 4. Liquid frequently and change them if contaminated. 5. Use radioactive waste container to collect the waste. 6. Check

  20. Radioactive Waste: 1. Radioactive waste from your lab is

    E-print Network

    Lance, Veronica P.

    Radioactive Waste: 1. Radioactive waste from your lab is collected by the RSO. 2. Dry radioactive waste must be segregated by isotope. 3. Liquid radioactive waste must be separated by isotope. 4. Liquid your gloves frequently and change them if contaminated. 5. Use radioactive waste container to collect

  1. Improved spatial resolution for U-series dating of opal at Yucca Mountain, Nevada, USA, using ion-microprobe and microdigestion methods

    USGS Publications Warehouse

    Paces, J.B.; Neymark, L.A.; Wooden, J.L.; Persing, H.M.

    2004-01-01

    Two novel methods of in situ isotope analysis, ion microprobe and microdigestion, were used for 230Th/U and 234U/238U dating of finely laminated opal hemispheres formed in unsaturated felsic tuff at Yucca Mountain, Nevada, proposed site for a high-level radioactive waste repository. Both methods allow analysis of layers as many as several orders of magnitude thinner than standard methods using total hemisphere digestion that were reported previously. Average growth rates calculated from data at this improved spatial resolution verified that opal grew at extremely slow rates over the last million years. Growth rates of 0.58 and 0.69 mm/m.y. were obtained for the outer 305 and 740 ??m of two opal hemispheres analyzed by ion microprobe, and 0.68 mm/m.y. for the outer 22 ??m of one of these same hemispheres analyzed by sequential microdigestion. These Pleistocene growth rates are 2 to 10 times slower than those calculated for older secondary calcite and silica mineral coatings deposited over the last 5 to 10 m.y. dated by the U-Pb method and may reflect differences between Miocene and Pleistocene seepage flux. The microdigestion data also imply that opal growth rates may have varied over the last 40 k.y. These data are the first indication that growth rates and associated seepage in the proposed repository horizon may correlate with changes in late Pleistocene climate, involving faster growth during wetter, cooler climates (glacial maximum), slower growth during transition climates, and no growth during the most arid climate (modern). Data collected at this refined spatial scale may lead to a better understanding of the hydrologic variability expected within the thick unsaturated zone at Yucca Mountain over the time scale of interest for radioactive waste isolation. ?? 2004 Elsevier Ltd.

  2. Radioactive Waste Management Basis

    SciTech Connect

    Perkins, B K

    2009-06-03

    The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  3. Radioactive waste disposal package

    DOEpatents

    Lampe, Robert F. (Bethel Park, PA)

    1986-01-01

    A radioactive waste disposal package comprising a canister for containing vitrified radioactive waste material and a sealed outer shell encapsulating the canister. A solid block of filler material is supported in said shell and convertible into a liquid state for flow into the space between the canister and outer shell and subsequently hardened to form a solid, impervious layer occupying such space.

  4. A Remote Radioactivity Experiment

    ERIC Educational Resources Information Center

    Jona, Kemi; Vondracek, Mark

    2013-01-01

    Imagine a high school with very few experimental resources and limited budgets that prevent the purchase of even basic laboratory equipment. For example, many high schools do not have the means of experimentally studying radioactivity because they lack Geiger counters and/or good radioactive sources. This was the case at the first high school one…

  5. Temporary Personal Radioactivity

    ERIC Educational Resources Information Center

    Myers, Fred

    2012-01-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances. (Contains 1 table and 2…

  6. Radioactive Wastes. Revised.

    ERIC Educational Resources Information Center

    Fox, Charles H.

    This publication is one of a series of information booklets for the general public published by the United States Atomic Energy Commission. This booklet deals with the handling, processing and disposal of radioactive wastes. Among the topics discussed are: The Nature of Radioactive Wastes; Waste Management; and Research and Development. There are…

  7. Temporary Personal Radioactivity

    NASA Astrophysics Data System (ADS)

    Myers, Fred

    2012-11-01

    As part of a bone scan procedure to look for the spread of prostate cancer, I was injected with radioactive technetium. In an effort to occupy/distract my mind, I used a Geiger counter to determine if the radioactive count obeyed the inverse-square law as a sensor was moved away from my bladder by incremental distances.

  8. Name______ __________________________ Lab 5. Radioactivity & Radiation

    E-print Network

    Perfect, Ed

    1 Name______ __________________________ Lab 5. Radioactivity & Radiation Radiation pollution in general. On the other hand, radioactive waste is an inevitable byproduct of nuclear reactions, is lethal to all living organisms. Furthermore, radioactive waste can be extremely persistent, and can

  9. Consumer Products Containing Radioactive Materials

    MedlinePLUS

    ... radioactive material. Many consumer items containing naturally occurring radioactivity can be safely used. This fact sheet describes ... levels of uranium and radium. The amount of radioactivity incorporated into the plants is low and does ...

  10. 238U-230Th-226Ra disequilibria in dacite and plagioclase from the 2004-2005 eruption of Mount St. Helens: Chapter 36 in A volcano rekindled: the renewed eruption of Mount St. Helens, 2004-2006

    USGS Publications Warehouse

    Cooper, Kari M.; Donnelly, Carrie T.

    2008-01-01

    230Th)/(232Th) measured for the 1980s reference suite. However, (230Th)/(232Th) for plagioclase separates for dome samples erupted during October and November 2004 are significantly different from corresponding whole-rock values, which suggests that a large fraction (>30 percent) of crystals in each sample are foreign to the host liquid. Furthermore, plagioclase in the two 2004 samples have U-series characteristics distinct from each other and from plagioclase in dacite erupted in 1982, indicating that (1) the current eruption must include a component of crystals (and potentially associated magma) that were not sampled by the 1980-86 eruption, and (2) dacite magmas erupted only a month apart in 2004 contain different populations of crystals, indicating that this foreign component is highly heterogeneous within the 2004-5 magma reservoir.

  11. Understanding radioactive waste

    SciTech Connect

    Murray, R.L.

    1981-12-01

    This document contains information on all aspects of radioactive wastes. Facts are presented about radioactive wastes simply, clearly and in an unbiased manner which makes the information readily accessible to the interested public. The contents are as follows: questions and concerns about wastes; atoms and chemistry; radioactivity; kinds of radiation; biological effects of radiation; radiation standards and protection; fission and fission products; the Manhattan Project; defense and development; uses of isotopes and radiation; classification of wastes; spent fuels from nuclear reactors; storage of spent fuel; reprocessing, recycling, and resources; uranium mill tailings; low-level wastes; transportation; methods of handling high-level nuclear wastes; project salt vault; multiple barrier approach; research on waste isolation; legal requiremnts; the national waste management program; societal aspects of radioactive wastes; perspectives; glossary; appendix A (scientific American articles); appendix B (reference material on wastes). (ATT)

  12. Radioactive gold ring dermatitis

    SciTech Connect

    Miller, R.A.; Aldrich, J.E. )

    1990-08-01

    A superficial squamous cell carcinoma developed in a woman who wore a radioactive gold ring for more than 30 years. Only part of the ring was radioactive. Radiation dose measurements indicated that the dose to basal skin layer was 2.4 Gy (240 rad) per week. If it is assumed that the woman continually wore her wedding ring for 37 years since purchase, she would have received a maximum dose of approximately 4600 Gy.

  13. Dynamic radioactive particle source

    DOEpatents

    Moore, Murray E.; Gauss, Adam Benjamin; Justus, Alan Lawrence

    2012-06-26

    A method and apparatus for providing a timed, synchronized dynamic alpha or beta particle source for testing the response of continuous air monitors (CAMs) for airborne alpha or beta emitters is provided. The method includes providing a radioactive source; placing the radioactive source inside the detection volume of a CAM; and introducing an alpha or beta-emitting isotope while the CAM is in a normal functioning mode.

  14. Alpha Decay Discovery of Radioactivity

    E-print Network

    Smith, Nathanael J.

    Alpha Decay L11-III 1 / 13 #12;Discovery of Radioactivity Radioactivity was discovered by Becquerel://hyperphysics.phy-astr.gsu.edu/hbase/hph.html 2 / 13 #12;Types of Radioactivity emission charge mass identity +2e 4mp He nucleus -e me electron 0 ? EM radiation B radioactive source 3 / 13 #12;Alpha Decay Generic Decay Equation A ZX -- A-4 Z

  15. Radioactivity in food crops

    SciTech Connect

    Drury, J.S.; Baldauf, M.F.; Daniel, E.W.; Fore, C.S.; Uziel, M.S.

    1983-05-01

    Published levels of radioactivity in food crops from 21 countries and 4 island chains of Oceania are listed. The tabulation includes more than 3000 examples of 100 different crops. Data are arranged alphabetically by food crop and geographical origin. The sampling date, nuclide measured, mean radioactivity, range of radioactivities, sample basis, number of samples analyzed, and bibliographic citation are given for each entry, when available. Analyses were reported most frequently for /sup 137/Cs, /sup 40/K, /sup 90/Sr, /sup 226/Ra, /sup 228/Ra, plutonium, uranium, total alpha, and total beta, but a few authors also reported data for /sup 241/Am, /sup 7/Be, /sup 60/Co, /sup 55/Fe, /sup 3/H, /sup 131/I, /sup 54/Mn, /sup 95/Nb, /sup 210/Pb, /sup 210/Po, /sup 106/Ru, /sup 125/Sb, /sup 228/Th, /sup 232/Th, and /sup 95/Zr. Based on the reported data it appears that radioactivity from alpha emitters in food crops is usually low, on the order of 0.1 Bq.g/sup -1/ (wet weight) or less. Reported values of beta radiation in a given crop generally appear to be several orders of magnitude greater than those of alpha emitters. The most striking aspect of the data is the great range of radioactivity reported for a given nuclide in similar food crops with different geographical origins.

  16. Radioactive mixed waste disposal

    SciTech Connect

    Jasen, W.G.; Erpenbeck, E.G.

    1993-02-01

    Various types of waste have been generated during the 50-year history of the Hanford Site. Regulatory changes in the last 20 years have provided the emphasis for better management of these wastes. Interpretations of the Atomic Energy Act of 1954 (AEA), the Resource Conservation and Recovery Act of 1976 (RCRA), and the Hazardous and Solid Waste Amendments (HSWA) have led to the definition of radioactive mixed wastes (RMW). The radioactive and hazardous properties of these wastes have resulted in the initiation of special projects for the management of these wastes. Other solid wastes at the Hanford Site include low-level wastes, transuranic (TRU), and nonradioactive hazardous wastes. This paper describes a system for the treatment, storage, and disposal (TSD) of solid radioactive waste.

  17. Radioactivity of Consumer Products

    NASA Astrophysics Data System (ADS)

    Peterson, David; Jokisch, Derek; Fulmer, Philip

    2006-11-01

    A variety of consumer products and household items contain varying amounts of radioactivity. Examples of these items include: FiestaWare and similar glazed china, salt substitute, bananas, brazil nuts, lantern mantles, smoke detectors and depression glass. Many of these items contain natural sources of radioactivity such as Uranium, Thorium, Radium and Potassium. A few contain man-made sources like Americium. This presentation will detail the sources and relative radioactivity of these items (including demonstrations). Further, measurements of the isotopic ratios of Uranium-235 and Uranium-238 in several pieces of china will be compared to historical uses of natural and depleted Uranium. Finally, the presenters will discuss radiation safety as it pertains to the use of these items.

  18. Radioactive Decay - An Analog.

    ERIC Educational Resources Information Center

    McGeachy, Frank

    1988-01-01

    Presents an analog of radioactive decay that allows the student to grasp the concept of half life and the exponential nature of the decay process. The analog is devised to use small, colored, plastic poker chips or counters. Provides the typical data and a graph which supports the analog. (YP)

  19. TABLE OF RADIOACTIVE ELEMENTS.

    SciTech Connect

    HOLDEN,N.E.

    2001-06-29

    For those chemical elements which have no stable nuclides with a terrestrial isotopic composition, the data on radioactive half-lives and relative atomic masses for the nuclides of interest and importance have been evaluated and the recommended values and uncertainties are listed.

  20. Radioactivity: A Natural Phenomenon.

    ERIC Educational Resources Information Center

    Ronneau, C.

    1990-01-01

    Discussed is misinformation people have on the subject of radiation. The importance of comparing artificial source levels of radiation to natural levels is emphasized. Measurements of radioactivity, its consequences, and comparisons between the risks induced by radiation in the environment and from artificial sources are included. (KR)

  1. Viewer Makes Radioactivity "Visible"

    NASA Technical Reports Server (NTRS)

    Yin, L. I.

    1983-01-01

    Battery operated viewer demonstrates feasibility of generating threedimensional visible light simulations of objects that emit X-ray or gamma rays. Ray paths are traced for two pinhold positions to show location of reconstructed image. Images formed by pinholes are converted to intensified visible-light images. Applications range from radioactivity contamination surveys to monitoring radioisotope absorption in tumors.

  2. Detecting Illicit Radioactive Sources

    SciTech Connect

    McDonald, Joseph C.; Coursey, Bert; Carter, Michael

    2004-11-01

    Specialized instruments have been developed to detect the presence of illicit radioactive sources that may be used by terrorists in radiation dispersal devices, so-called ''dirty bombs'' or improvised nuclear devices. This article discusses developments in devices to detect and measure radiation.

  3. Vacuuming radioactive sludge

    SciTech Connect

    2006-10-16

    Vacuuming an estimated 55 cubic yards of radioactive sludge from the floor of Hanford's K East Basin was a complicated process. Workers stood on grates suspended above the 20-foot deep basin and manipulated vacuuming equipment at the end of long poles--using underwater cameras to guide their work.

  4. Radioactivity and foods

    SciTech Connect

    Olszyna-Marzys, A.E. )

    1991-01-01

    The purpose of this article is to describe and contrast two relationships between radiation and food--on the one hand, beneficial preservation of food by controlled exposure to ionizing radiation; and, on the other, contamination of food by accidental incorporation of radioactive nuclides within the food itself. In food irradiation, electrons or electromagnetic radiation is used to destroy microorganisms and insects or prevent seed germination. The economic advantages and health benefits of sterilizing food in this manner are clear, and numerous studies have confirmed that under strictly controlled conditions no undersirable changes or induced radioactivity is produced in the irradiated food. An altogether different situation is presented by exposure of food animals and farming areas to radioactive materials, as occurred after the major Soviet nuclear reactor accident at Chenobyl. This article furnishes the basic information needed to understand the nature of food contamination associated with that event and describes the work of international organizations seeking to establish appropriate safe limits for levels of radioactivity in foods.

  5. Environmental Radioactivity, Temperature, and Precipitation.

    ERIC Educational Resources Information Center

    Riland, Carson A.

    1996-01-01

    Reports that environmental radioactivity levels vary with temperature and precipitation and these effects are due to radon. Discusses the measurement of this environmental radioactivity and the theory behind it. (JRH)

  6. How is radioactive material transported? Radioactive material is transported by trucks, rail, and

    E-print Network

    How is radioactive material transported? Radioactive material is transported by trucks, rail, and other shipping methods. Shipments involving significant amounts of radioactive material are required to have documentation, labels, and placards identifying the cargo as radioactive. Radioactive material

  7. Airborne radioactive contamination monitoring

    SciTech Connect

    Whitley, C.R.; Adams, J.R.; Bounds, J.A.; MacArthur, D.W.

    1996-03-01

    Current technologies for the detection of airborne radioactive contamination do not provide real-time capability. Most of these techniques are based on the capture of particulate matter in air onto filters which are then processed in the laboratory; thus, the turnaround time for detection of contamination can be many days. To address this shortcoming, an effort is underway to adapt LRAD (Long-Range-Alpha-Detection) technology for real-time monitoring of airborne releases of alpa-emitting radionuclides. Alpha decays in air create ionization that can be subsequently collected on electrodes, producing a current that is proportional to the amount of radioactive material present. Using external fans on a pipe containing LRAD detectors, controlled samples of ambient air can be continuously tested for the presence of radioactive contamination. Current prototypes include a two-chamber model. Sampled air is drawn through a particulate filter and then through the first chamber, which uses an electrostatic filter at its entrance to remove ambient ionization. At its exit, ionization that occurred due to the presence of radon is collected and recorded. The air then passes through a length of pipe to allow some decay of short-lived radon species. A second chamber identical to the first monitors the remaining activity. Further development is necessary on air samples without the use of particulate filtering, both to distinguish ionization that can pass through the initial electrostatic filter on otherwise inert particulate matter from that produced through the decay of radioactive material and to separate both of these from the radon contribution. The end product could provide a sensitive, cost-effective, real-time method of determining the presence of airborne radioactive contamination.

  8. Tracking Radioactive Sources in Commerce

    E-print Network

    Tracking Radioactive Sources in Commerce Deborah Kopsick, U.S. Environmental Protection Agency Schultz, Dudley Pinson; NorthWest Nuclear, LLC Millions of radioactive material packages are shipped each year © In transit, sealed radioactive sources may be vulnerable to loss or theft due to: ß Minimal

  9. Natural radioactivity and radiological hazards assessment of bone-coal from a vanadium mine in central China

    NASA Astrophysics Data System (ADS)

    Huang, Yan-Jun; Chen, Chao-Feng; Huang, Yi-Chao; Yue, Qi-Jian; Zhong, Chun-Ming; Tan, Cheng-Jun

    2015-02-01

    A comprehensive utilization project of bone-coal in a vanadium mine was proposing in recent years in central China. Based on the analysis of 31 representative bone-coal samples from 9 boreholes at various depth drilled in planning initial minery, the average activity concentrations of 238U, 226Ra, 232Th and 40K were determined in the range of 196.4-653.3 Bq/kg, 200.2-564.4 Bq/kg, 9.4-64.6 Bq/kg and 71.5-345.4 Bq/kg, respectively. The major natural radionuclides were identified as U-series nuclides with the activity concentrations obviously higher than common coal. The estimated absorbed dose rates in the air varied between 107.1 and 310.5 nGy/h. The averaged external annual effective dose due to the radioactivity in the bone-coal was predicted as 0.37 mSv/a, and the main contribution is 87.5% for U-series. The radium equivalent activity, the external and internal indices of most of the samples were shown with high values of an unacceptable level, which indicated the bone-coal would carry a considerable radiation hazard to the workers and the local individuals. The hazard of radon inhalation should be focused during mining and following processes. Further radiological assessment should be carried out as the natural radioactivity in the bone-coal would be technically enriched during the combustion process of the bone-coal and utilization of the byproducts.

  10. Radioactive ion detector

    DOEpatents

    Bower, K.E.; Weeks, D.R.

    1997-08-12

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity. 2 figs.

  11. Radioactive ion detector

    DOEpatents

    Bower, Kenneth E. (Los Alamos, NM); Weeks, Donald R. (Saratoga, CA)

    1997-01-01

    Apparatus for detecting the presence, in aqueous media, of substances which emit alpha and/or beta radiation and determining the oxidation state of these radioactive substances, that is, whether they are in cationic or anionic form. In one embodiment, a sensor assembly has two elements, one comprised of an ion-exchange material which binds cations and the other comprised of an ion-exchange material which binds anions. Each ion-exchange element is further comprised of a scintillation plastic and a photocurrent generator. When a radioactive substance to which the sensor is exposed binds to either element and emits alpha or beta particles, photons produced in the scintillation plastic illuminate the photocurrent generator of that element. Sensing apparatus senses generator output and thereby indicates whether cationic species or anionic species or both are present and also provides an indication of species quantity.

  12. Sources of radioactive ions

    SciTech Connect

    Alonso, J.R.

    1985-05-01

    Beams of unstable nuclei can be formed by direct injection of the radioactive atoms into an ion source, or by using the momentum of the primary production beam as the basis for the secondary beam. The effectiveness of this latter mechanism in secondary beam formation, i.e., the quality of the emerging beam (emittance, intensity, energy spread), depends critically on the nuclear reaction kinematics, and on the magnitude of the incident beam energy. When this beam energy significantly exceeds the energies typical of the nuclear reaction process, many of the qualities of the incident beam can be passed on to the secondary beam. Factors affecting secondary beam quality are discussed, along with techniques for isolating and purifying a specific secondary product. The ongoing radioactive beam program at the Bevalac is used as an example, with applications, present performance and plans for improvements.

  13. Table of radioactive elements

    SciTech Connect

    Holden, N.E.

    1985-01-01

    As has been the custom in the past, the Commission publishes a table of relative atomic masses and halflives of selected radionuclides. The information contained in this table will enable the user to calculate the atomic weight for radioactive materials with a variety of isotopic compositions. The atomic masses have been taken from the 1984 Atomic Mass Table. Some of the halflives have already been documented.

  14. Radioactive waste storage issues

    SciTech Connect

    Kunz, D.E.

    1994-08-15

    In the United States we generate greater than 500 million tons of toxic waste per year which pose a threat to human health and the environment. Some of the most toxic of these wastes are those that are radioactively contaminated. This thesis explores the need for permanent disposal facilities to isolate radioactive waste materials that are being stored temporarily, and therefore potentially unsafely, at generating facilities. Because of current controversies involving the interstate transfer of toxic waste, more states are restricting the flow of wastes into - their borders with the resultant outcome of requiring the management (storage and disposal) of wastes generated solely within a state`s boundary to remain there. The purpose of this project is to study nuclear waste storage issues and public perceptions of this important matter. Temporary storage at generating facilities is a cause for safety concerns and underscores, the need for the opening of permanent disposal sites. Political controversies and public concern are forcing states to look within their own borders to find solutions to this difficult problem. Permanent disposal or retrievable storage for radioactive waste may become a necessity in the near future in Colorado. Suitable areas that could support - a nuclear storage/disposal site need to be explored to make certain the health, safety and environment of our citizens now, and that of future generations, will be protected.

  15. ASSESSMENT OF RADIOACTIVE AND NON-RADIOACTIVE CONTAMINANTS FOUND IN LOW LEVEL RADIOACTIVE WASTE STREAMS

    SciTech Connect

    R.H. Little, P.R. Maul, J.S.S. Penfoldag

    2003-02-27

    This paper describes and presents the findings from two studies undertaken for the European Commission to assess the long-term impact upon the environment and human health of non-radioactive contaminants found in various low level radioactive waste streams. The initial study investigated the application of safety assessment approaches developed for radioactive contaminants to the assessment of nonradioactive contaminants in low level radioactive waste. It demonstrated how disposal limits could be derived for a range of non-radioactive contaminants and generic disposal facilities. The follow-up study used the same approach but undertook more detailed, disposal system specific calculations, assessing the impacts of both the non-radioactive and radioactive contaminants. The calculations undertaken indicated that it is prudent to consider non-radioactive, as well as radioactive contaminants, when assessing the impacts of low level radioactive waste disposal. For some waste streams with relatively low concentrations of radionuclides, the potential post-closure disposal impacts from non-radioactive contaminants can be comparable with the potential radiological impacts. For such waste streams there is therefore an added incentive to explore options for recycling the materials involved wherever possible.

  16. PERSPECTIVE: Fireworks and radioactivity

    NASA Astrophysics Data System (ADS)

    Breitenecker, Katharina

    2009-09-01

    Katharina Breitenecker Fireworks, the one and only amongst all other pyrotechnic applications, have pleased the hearts and minds of billions of people all over the world for almost 1000 years. Even though pyrotechnics were originally developed in order to fulfil the needs of military purposes, fireworks began to form a unique part of the cultural heritage of many countries, presumably starting in ancient China during the Song Dynasty (960-1280 AD). Festivities like New Year's Eve, national holidays or activities like music festivals and parish fairs are crowned by a firework display. Fireworks have traditionally been associated with Independence Day celebrations, like 4 July in the United States, Guy Fawkes' Night (5 November) in Britain, or Bastille Day (14 July) in France. Much of Chinese culture is associated with the use of firecrackers to celebrate the New Year and other important occasions. The fascination of fireworks and firecrackers is due to the brilliant colours and booming noises, which have a universal appeal to our basic senses [1]. The basic components of any traditional civil firework is black powder, a mixture of about 75% potassium nitrate, 15% charcoal, and about 10% sulfur [2]. Without the addition of a colouring agent, the fuel would provide an almost white light. Therefore, several metal salts can be added to cause colourful luminescence upon combustion. In general barium is used to obtain a green coloured flame, strontium for red, copper for blue and sodium for yellow [2, 3]. The use of pyrotechnics has raised issues pertaining to health concerns. The health aspects are not only restricted to injuries by accidental ignition of certain devices. Moreover, several recent works identified fireworks and pyrotechnics as causing environmental pollution, which might result in a potential hazard concerning health aspects. The fundamental problem in this respect is that all chemicals used are dispersed in the environment by combustion. This includes both reaction products and unburnt constituents of a pyrotechnic mixture. One major environmental concern in pyrotechnics focuses on the emission of heavy metals. This is the topic discussed in the article by Georg Steinhauser and Andreas Musilek in this issue [4]. A possible interrelationship between respiratory effects and fireworks emissions of barium-rich aerosols was also raised last year [5]. In recent years the potential hazard of naturally occurring radioactive material has become of importance to the scientific community. Naturally occurring radionuclides can be of terrestrial or cosmological origin. Terrestrial radionuclides were present in the presolar cloud that later contracted in order to build our solar system. These radionuclides—mainly heavy metals—and their non-radioactive isotopes are nowadays fixed in the matrix of the Earth's structure. Usually, their percentage is quite small compared to their respective stable isotopes—though there are exceptions like in the case of radium. The problem with environmental pollution due to naturally occurring radioactive material begins when this material is concentrated due to mining and milling, and later further processed [6]. Environmental pollution due to radioactive material goes back as far as the Copper and Iron Ages, when the first mines were erected in order to mine ores (gold, silver, copper, iron, etc), resulting in naturally occurring radioactive material being set free with other dusts into the atmosphere. So where is the link between pyrotechnics and radioactivity? In this article presented by Georg Steinhauser and Andreas Musilek [4], the pyrotechnic ingredients barium nitrate and strontium nitrate are explored with respect to their chemical similarities to radium. The fundamental question, therefore, was whether radium can be processed together with barium and strontium. If so, the production and ignition of these pyrotechnic ingredients could cause atmospheric pollution with radium aerosols, resulting in potential negative health effects, unless an extensive purification of the ores is

  17. RADIOACTIVE MATERIALS SENSORS

    SciTech Connect

    Mayo, Robert M.; Stephens, Daniel L.

    2009-09-15

    Providing technical means to detect, prevent, and reverse the threat of potential illicit use of radiological or nuclear materials is among the greatest challenges facing contemporary science and technology. In this short article, we provide brief description and overview of the state-of-the-art in sensor development for the detection of radioactive materials, as well as an identification of the technical needs and challenges faced by the detection community. We begin with a discussion of gamma-ray and neutron detectors and spectrometers, followed by a description of imaging sensors, active interrogation, and materials development, before closing with a brief discussion of the unique challenges posed in fielding sensor systems.

  18. Radioactive waste material disposal

    DOEpatents

    Forsberg, Charles W. (155 Newport Dr., Oak Ridge, TN 37830); Beahm, Edward C. (106 Cooper Cir., Oak Ridge, TN 37830); Parker, George W. (321 Dominion Cir., Knoxville, TN 37922)

    1995-01-01

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide.

  19. Radioactive waste material disposal

    DOEpatents

    Forsberg, C.W.; Beahm, E.C.; Parker, G.W.

    1995-10-24

    The invention is a process for direct conversion of solid radioactive waste, particularly spent nuclear fuel and its cladding, if any, into a solidified waste glass. A sacrificial metal oxide, dissolved in a glass bath, is used to oxidize elemental metal and any carbon values present in the waste as they are fed to the bath. Two different modes of operation are possible, depending on the sacrificial metal oxide employed. In the first mode, a regenerable sacrificial oxide, e.g., PbO, is employed, while the second mode features use of disposable oxides such as ferric oxide. 3 figs.

  20. Radioactive and magnetic investigations

    NASA Technical Reports Server (NTRS)

    Heye, D.; Beiersdorf, H.

    1979-01-01

    Age and growth pattern determination of manganese nodules were explored. Two methods are discussed: (1) measurement of the presence of radioactive iodine isotopes; which is effective only up to 3.105 years, and (2) measurements of magnetism. The growth rates of three nodules were determined. The surface of the nodule was recent, and the overall age of the nodule could be determined with accuracy of better than 30%. Measurement of paleomagnetic effect was attempted to determine wider age ranges, however, the measured sign changes could not be interpreted as paleomagnetic reversals.

  1. Levels of radioactivity in Qatar

    SciTech Connect

    Al-Thani, A.A.; Abdul-Majid, S.; Mohammed, K.

    1995-12-31

    The levels of natural and man-made radioactivity in soil and seabed were measured in Qatar to assess radiation exposure levels and to evaluate any radioactive contamination that may have reached the country from fallout or due to the Chernobyl accident radioactivity release. Qatar peninsula is located on the Arabian Gulf, 4500 km from Chernobyl, and has an area of {approximately}11,600 km{sup 2} and a population of {approximately}600,000.

  2. Radioactive waste processing apparatus

    DOEpatents

    Nelson, Robert E. (Lombard, IL); Ziegler, Anton A. (Darien, IL); Serino, David F. (Maplewood, MN); Basnar, Paul J. (Western Springs, IL)

    1987-01-01

    Apparatus for use in processing radioactive waste materials for shipment and storage in solid form in a container is disclosed. The container includes a top, and an opening in the top which is smaller than the outer circumference of the container. The apparatus includes an enclosure into which the container is placed, solution feed apparatus for adding a solution containing radioactive waste materials into the container through the container opening, and at least one rotatable blade for blending the solution with a fixing agent such as cement or the like as the solution is added into the container. The blade is constructed so that it can pass through the opening in the top of the container. The rotational axis of the blade is displaced from the center of the blade so that after the blade passes through the opening, the blade and container can be adjusted so that one edge of the blade is adjacent the cylindrical wall of the container, to insure thorough mixing. When the blade is inside the container, a substantially sealed chamber is formed to contain vapors created by the chemical action of the waste solution and fixant, and vapors emanating through the opening in the container.

  3. Radioactively labelled porphyrin derivatives

    NASA Astrophysics Data System (ADS)

    Koní?ová, R.; Ernestová, M.; Jedináková-K?ížová, V.; Král, V.

    2003-01-01

    Radioactive labelling of guanidine-bearing tetraphenylporphyrin and Dy—texaphyrin with selected radionuclides (166Ho and 90Y) is described. A basic characterisation of studied porphyrin and texaphyrin, including their behaviour in a wide range of pH values and data on holmium and yttrium complexation with these compounds was probed using UV-VIS absorption spectrometry. The labelling yield of these macrocyclic molecules depends on the pH of the reaction mixture, metal: ligand ratio and time of incubation. Optimal reaction conditions for formation of porphyrin and texaphyrin radioactive complexes were determined by thin layer chromatography with the detection of ?- activity. The ability of porphyrin derivatives to bind anions was examined as well. Our experiments were focused on perrhenate ion (ReO4 -) because radiopharmaceuticals labelled with isotopes 186Re and 188Re play an important role in therapy of numerous tumour diseases. The possibility of applying ReO4 - anion directly for labelling purposes, without the necessity of its reduction to lower oxidation state, was not proved.

  4. RSSC RADIOACTIVE WASTE DISPOSAL 08/2011 7-1 RADIOACTIVE WASTE DISPOSAL

    E-print Network

    Slatton, Clint

    RSSC RADIOACTIVE WASTE DISPOSAL 08/2011 7-1 CHAPTER 7 RADIOACTIVE WASTE DISPOSAL PAGE I. Radioactive Waste Disposal ............................................................................................ 7-2 II. Radiation Control Technique #2 Instructions for Preparation of Radioactive Waste

  5. Stefan Meyer: Pioneer of Radioactivity

    NASA Astrophysics Data System (ADS)

    Reiter, Wolfgang L.

    2001-03-01

    Stefan Meyer was one of the pioneers in radioactivity research and director of the Vienna Radium Institute, the first institution in the world devoted exclusively to radioactivity. I give here a biographical sketch of Meyer and of some of his colleagues and an overview of the research activities at the Radium Institute.

  6. Radioactive elements in stellar atmospheres

    SciTech Connect

    Gopka, Vira; Yushchenko, Alexander; Goriely, Stephane; Shavrina, Angelina; Kang, Young Woon

    2006-07-12

    The identification of lines of radioactive elements (Tc, Pm and elements with 83radioactive decay of Th and U in the upper levels of stellar atmospheres, contamination of stellar atmosphere by recent SN explosion, and spallation reactions.

  7. Advances -ray spectrometry for environmental radioactivity monitoring

    E-print Network

    Roma "La Sapienza", Università di

    Advances -ray spectrometry for environmental radioactivity monitoring University of Ferrara Ph;· Environmental radioactivity monitoring: social, scientific and technological motivations · -ray spectrometry application [Xhixha et al. 2012] Environmental radioactivity monitoring: social, scientific and technological

  8. Heavy fragment radioactivities

    SciTech Connect

    Price, P.B.

    1987-12-10

    This recently discovered mode of radioactive decay, like alpha decay and spontaneous fission, is believed to involve tunneling through the deformation-energy barrier between a very heavy nucleus and two separated fragments the sum of whose masses is less than the mass of the parent nucleus. In all known cases the heavier of the two fragments is close to doubly magic /sup 208/Pb, and the lighter fragment has even Z. Four isotopes of Ra are known to emit /sup 14/C nuclei; several isotopes of U as well as /sup 230/Th and /sup 231/Pa emit Ne nuclei; and /sup 234/U exhibits four hadronic decay modes: alpha decay, spontaneous fission, Ne decay and Mg decay.

  9. Sequestering of radioactive waste

    SciTech Connect

    Penberthy, H.L.; Hotaling, D.J.

    1983-09-13

    A method for sequestering radioactive waste materials against dissolution and migration into the biosphere during prolonged storage is disclosed. The method comprises incorporating the waste materials as oxides into a mass of molten glass, and subsequently casting the homogeneous molten mass in an inert chemically durable glass container supported by a mold. The container is then sealed and permitted to cool, thereby forming a solid mass having an outer layer or cladding of nonradioactive glass. The glass used for the container preferably is a leach resistant soda-lime-alumina-silica glass similar to conventional bottle glass, and the coefficient of expansion thereof should be sufficiently close to that of the contents to avoid excessive stress at the interface upon cooling.

  10. Radioactive waste processing apparatus

    DOEpatents

    Nelson, R.E.; Ziegler, A.A.; Serino, D.F.; Basnar, P.J.

    1985-08-30

    Apparatus for use in processing radioactive waste materials for shipment and storage in solid form in a container is disclosed. The container includes a top, and an opening in the top which is smaller than the outer circumference of the container. The apparatus includes an enclosure into which the container is placed, solution feed apparatus for adding a solution containing radioactive waste materials into the container through the container opening, and at least one rotatable blade for blending the solution with a fixing agent such as cement or the like as the solution is added into the container. The blade is constructed so that it can pass through the opening in the top of the container. The rotational axis of the blade is displaced from the center of the blade so that after the blade passes through the opening, the blade and container can be adjusted so that one edge of the blade is adjacent the cylindrical wall of the container, to insure thorough mixing. When the blade is inside the container, a substantially sealed chamber is formed to contain vapors created by the chemical action of the waste solution and fixant, and vapors emanating through the opening in the container. The chamber may be formed by placing a removable extension over the top of the container. The extension communicates with the apparatus so that such vapors are contained within the container, extension and solution feed apparatus. A portion of the chamber includes coolant which condenses the vapors. The resulting condensate is returned to the container by the force of gravity.

  11. Star formation and extinct radioactivities

    NASA Technical Reports Server (NTRS)

    Cameron, A. G. W.

    1984-01-01

    An assessment is made of the evidence for the existence of now-extinct radioactivities in primitive solar system material, giving attention to implications for the early stages of sun and solar system formation. The characteristics of possible disturbances in dense molecular clouds which can initiate the formation of cloud cores is discussed, with emphasis on these disturbances able to generate fresh radioactivities. A one-solar mass red giant star on the asymptotic giant branch appears to have been the best candidate to account for the short-lived extinct radioactivities in the early solar system.

  12. Radioactive Waste Management

    NASA Astrophysics Data System (ADS)

    Baisden, P. A.; Atkins-Duffin, C. E.

    Issues related to the management of radioactive wastes are presented with specific emphasis on high-level wastes generated as a result of energy and materials production using nuclear reactors. The final disposition of these high-level wastes depends on which nuclear fuel cycle is pursued, and range from once-through burning of fuel in a light water reactor followed by direct disposal in a geologic repository to more advanced fuel cycles (AFCs) where the spent fuel is reprocessed or partitioned to recover the fissile material (primarily 235U and 239Pu) as well as the minor actinides (MAs) (neptunium, americium, and curium) and some long-lived fission products (e.g., 99Tc and 129I). In the latter fuel cycle, the fissile materials are recycled through a reactor to produce more energy, the short-lived fission products are vitrified and disposed of in a geologic repository, and the minor actinides and long-lived fission products are converted to less radiotoxic or otherwise stable nuclides by a process called transmutation. The advantages and disadvantages of the various fuel cycle options and the challenges to the management of nuclear wastes they represent are discussed.

  13. Radioactive decay data tables

    SciTech Connect

    Kocher, D.C.

    1981-01-01

    The estimation of radiation dose to man from either external or internal exposure to radionuclides requires a knowledge of the energies and intensities of the atomic and nuclear radiations emitted during the radioactive decay process. The availability of evaluated decay data for the large number of radionuclides of interest is thus of fundamental importance for radiation dosimetry. This handbook contains a compilation of decay data for approximately 500 radionuclides. These data constitute an evaluated data file constructed for use in the radiological assessment activities of the Technology Assessments Section of the Health and Safety Research Division at Oak Ridge National Laboratory. The radionuclides selected for this handbook include those occurring naturally in the environment, those of potential importance in routine or accidental releases from the nuclear fuel cycle, those of current interest in nuclear medicine and fusion reactor technology, and some of those of interest to Committee 2 of the International Commission on Radiological Protection for the estimation of annual limits on intake via inhalation and ingestion for occupationally exposed individuals.

  14. Radioactive waste material melter apparatus

    DOEpatents

    Newman, Darrell F. (Richland, WA); Ross, Wayne A. (Richland, WA)

    1990-01-01

    An apparatus for preparing metallic radioactive waste material for storage is disclosed. The radioactive waste material is placed in a radiation shielded enclosure. The waste material is then melted with a plasma torch and cast into a plurality of successive horizontal layers in a mold to form a radioactive ingot in the shape of a spent nuclear fuel rod storage canister. The apparatus comprises a radiation shielded enclosure having an opening adapted for receiving a conventional transfer cask within which radioactive waste material is transferred to the apparatus. A plasma torch is mounted within the enclosure. A mold is also received within the enclosure for receiving the melted waste material and cooling it to form an ingot. The enclosure is preferably constructed in at least two parts to enable easy transport of the apparatus from one nuclear site to another.

  15. Radioactive waste material melter apparatus

    DOEpatents

    Newman, D.F.; Ross, W.A.

    1990-04-24

    An apparatus for preparing metallic radioactive waste material for storage is disclosed. The radioactive waste material is placed in a radiation shielded enclosure. The waste material is then melted with a plasma torch and cast into a plurality of successive horizontal layers in a mold to form a radioactive ingot in the shape of a spent nuclear fuel rod storage canister. The apparatus comprises a radiation shielded enclosure having an opening adapted for receiving a conventional transfer cask within which radioactive waste material is transferred to the apparatus. A plasma torch is mounted within the enclosure. A mold is also received within the enclosure for receiving the melted waste material and cooling it to form an ingot. The enclosure is preferably constructed in at least two parts to enable easy transport of the apparatus from one nuclear site to another. 8 figs.

  16. Radioactivity connected with coal burning.

    PubMed

    Borio, R; Campos Venuti, G; Risica, S; Simula, S

    1985-10-01

    The enhanced environmental radioactivity resulting from the operation of a 72 MWe brown coal-fired power plant in central Italy is considered. A source-related control procedure is suggested. The calculated values for the atmospheric dispersion of radioactive effluents and the results of some measurements on brown coals, ash, environmental samples and gamma-exposure levels performed at representative points are reported. PMID:4081758

  17. 4. Nuclei and Radioactivity Paradoxes and Puzzles

    E-print Network

    Browder, Tom

    4. Nuclei and Radioactivity Paradoxes and Puzzles 1. This book is radioactive. 2. You are radioactive too, unless you have been dead for a long time. 3. The United States Bureau of Alcohol, Tobacco, and Firearms tests wine, gin, whisky, and vodka for radioactivity. If the product does not have sufficient

  18. Radioactivity of sand, groundwater and wild plants in northeast Sinai, Egypt.

    PubMed

    Ramadan, Khaled A; Seddeek, Mostafa K; Nijim, Abdelkareem; Sharshar, Taher; Badran, Hussein M

    2011-12-01

    The radioactivity levels are poorly studied in non-coastal arid regions. For this reason, 38 locations covering an area of about 350 km(2) in northeast Sinai, Egypt, were investigated by ?-ray spectroscopy. Moderately significant correlations among (238)U, (234)Th, and (226)Ra isotopes and low significant correlations between the concentrations of (238)U-series and (232)Th in sand were obtained. No evidence of correlation was found between the concentrations of radioisotopes and pH, grain size, total organic matter content, bicarbonate or calcium carbonate concentrations of the sand samples. The mean values of soil-to-plant transfer factor were 0.15, 0.18, 1.52 and 0.74 for (226)Ra, (232)Th, (40)K, and (137)Cs, respectively. The range of concentrations of (226)Ra,( 232)Th, and (40)K in water samples collected from five wells were<0.4-0.16,<0.4-0.13, and<0.15-1.62 Bq l(-1), respectively. The mean absorbed dose rate in outdoor air at a height of 1 m above the ground surface for the sand samples was 19.4 nGy h(-1). The Ra(eq) activities of the sands are lower than the recommended maximum value of 370 Bq kg(-1) criterion limit for building materials. PMID:22092101

  19. Storage depot for radioactive material

    DOEpatents

    Szulinski, Milton J. (Richland, WA)

    1983-01-01

    Vertical drilling of cylindrical holes in the soil, and the lining of such holes, provides storage vaults called caissons. A guarded depot is provided with a plurality of such caissons covered by shielded closures preventing radiation from penetrating through any linear gap to the atmosphere. The heat generated by the radioactive material is dissipated through the vertical liner of the well into the adjacent soil and thus to the ground surface so that most of the heat from the radioactive material is dissipated into the atmosphere in a manner involving no significant amount of biologically harmful radiation. The passive cooling of the radioactive material without reliance upon pumps, personnel, or other factor which might fail, constitutes one of the most advantageous features of this system. Moreover this system is resistant to damage from tornadoes or earthquakes. Hermetically sealed containers of radioactive material may be positioned in the caissons. Loading vehicles can travel throughout the depot to permit great flexibility of loading and unloading radioactive materials. Radioactive material can be shifted to a more closely spaced caisson after ageing sufficiently to generate much less heat. The quantity of material stored in a caisson is restricted by the average capacity for heat dissipation of the soil adjacent such caisson.

  20. Numerical dating of a Late Quaternary spit-shoreline complex at the northern end of Silver Lake playa, Mojave Desert, California: A comparison of the applicability of radiocarbon, luminescence, terrestrial cosmogenic nuclide, electron spin resonance, U-series and amino acid racemization methods

    USGS Publications Warehouse

    Owen, L.A.; Bright, Jordon; Finkel, R.C.; Jaiswal, M.K.; Kaufman, D.S.; Mahan, S.; Radtke, U.; Schneider, J.S.; Sharp, W.; Singhvi, A.K.; Warren, C.N.

    2007-01-01

    A Late Quaternary spit-shoreline complex on the northern shore of Pleistocene Lake Mojave of southeastern California, USA was studied with the goal of comparing accelerator mass spectrometry (AMS) radiocarbon, luminescence, electron spin resonance (ESR), terrestrial cosmogenic radionuclide (TCN) surface exposure, amino acid racemization (AAR) and U-series dating methods. The pattern of ages obtained by the different methods illustrates the complexity of processes acting in the lakeshore environment and highlights the utility of a multi-method approach. TCN surface exposure ages (mostly ???20-30 ka) record the initial erosion of shoreline benches, whereas radiocarbon ages on shells (determined in this and previous studies) within the spit, supported by AAR data, record its construction at fluctuating lake levels from ???16 to 10 ka. Luminescence ages on spit sediment (???6-7 ka) and ESR ages on spit shells (???4 ka) are anomalously young relative to radiocarbon ages of shells within the same deposits. The significance of the surprisingly young luminescence ages is not clear. The younger ESR ages could be a consequence of post-mortem enrichment of U in the shells. High concentrations of detrital thorium in tufa coating spit gravels inhibited the use of single-sample U-series dating. Detailed comparisons such as this provide one of the few means of assessing the accuracy of Quaternary dating techniques. More such comparisons are needed. ?? 2007 Elsevier Ltd and INQUA.

  1. Enhanced Radioactive Material Source Security.

    PubMed

    Klinger, Joseph G

    2016-02-01

    Requirements for additional security measures for sealed radioactive sources have evolved since they were first implemented after the terrorist events of 11 September 2001. This paper will describe the sequence of those measures, commencing with the early orders issued by the U.S. Nuclear Regulatory Commission to the May 2013 adoption of 10 CFR Part 37, Physical Protections of Category 1 and Category 2 Quantities of Radioactive Material. Part 37 requirements will be discussed in detail, as the 37 NRC Agreement States, which regulate approximately 88% of the radioactive material licensees, will be required to enact by 19 March 2016. In addition to the Part 37 requirements, the paper will also highlight some of the other ongoing efforts of the U.S. Department of Energy's National Nuclear Security Administration's Global Threat Reduction Initiative and the Conference of Radiation Control Program Directors. PMID:26717170

  2. Radioactive dating of the elements

    NASA Technical Reports Server (NTRS)

    Cowan, John J.; Thielemann, Friedrich-Karl; Truran, James W.

    1991-01-01

    The extent to which an accurate determination of the age of the Galaxy, and thus a lower bound on the age of the universe, can be obtained from radioactive dating is discussed. Emphasis is given to the use of the long-lived radioactive nuclei Re-187, Th-232, U-238, and U-235. The nature of the production sites of these and other potential Galactic chronometers is examined along with their production ratios. Age determinations from models of nucleocosmochronology are reviewed and compared with age determination from stellar sources and age constraints form cosmological considerations.

  3. Storage containers for radioactive material

    DOEpatents

    Groh, Edward F. (Naperville, IL); Cassidy, Dale A. (Valparaiso, IN); Dates, Leon R. (Elmwood Park, IL)

    1981-01-01

    A radioactive material storage system for use in the laboratory having a flat base plate with a groove in one surface thereof and a hollow pedestal extending perpendicularly away from the other surface thereof, a sealing gasket in the groove, a cover having a filter therein and an outwardly extending flange which fits over the plate, the groove and the gasket, and a clamp for maintaining the cover and the plate sealed together, whereby the plate and the cover and the clamp cooperate to provide a storage area for radioactive material readily accessible for use or

  4. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1992-01-01

    A systematic study of the induced radioactivity of the Long Duration Exposure Facility (LDEF) is being carried out in order to gather information about the low earth orbit radiation environment and its effects on materials. The large mass of the LDEF spacecraft, its stabilized configuration, and long mission duration have presented an opportunity to determine space radiation-induced radioactivities with a precision not possible before. Data presented include preliminary activities for steel and aluminum structural samples, and activation subexperiment foils. Effects seen in the data show a clear indication of the trapped proton anisotropy in the South Atlantic Anomaly and suggest contributions from different sources of external radiation fluxes.

  5. RadioActive101 Practices

    ERIC Educational Resources Information Center

    Brites, Maria José; Ravenscroft, Andrew; Dellow, James; Rainey, Colin; Jorge, Ana; Santos, Sílvio Correia; Rees, Angela; Auwärter, Andreas; Catalão, Daniel; Balica, Magda; Camilleri, Anthony F.

    2014-01-01

    In keeping with the overarching RadioActive101 (RA101) spirit and ethos, this report is the product of collaborative and joined-up thinking from within the European consortium spread across five countries. As such, it is not simply a single voice reporting on the experiences and knowledge gained during the project. Rather it is a range of…

  6. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1990-09-30

    This report discusses the nuclear structure of the following isotopes as a result of radioactive decays: neutron-deficient iridium isotopes; neutron-deficient platinum isotopes; neutron-deficient gold isotopes; neutron-deficient mercury isotopes; neutron-deficient thallium isotopes; neutron-deficient lead isotopes; neutron-deficient promethium isotopes; and neutron-deficient samarium isotopes.

  7. Politics of Radioactive Waste Disposal

    SciTech Connect

    Kemp, R.

    1994-01-01

    What role does public acceptance play in the siting of facilities and the selection of technologies designed to manage nuclear waste That's the question posed by Ray Kemp in The Politics of Radioactive Waste Disposal. To answer this question, Kemp assesses and compares the decision-making processes in Western Europe, Canada, and the United States.

  8. Sensor integration in radioactive environments

    NASA Astrophysics Data System (ADS)

    Harfensteller, Mark; Schilp, Michael; Eursch, Andreas; Zaeh, Michael F.

    2004-12-01

    Radioactive material of high activity levels has to be handled in a nuclear medicine environment. Until now most of these activities are done manually or by rudimentally automated processes. To increase radiation safety and process quality, smart automation strategies for these processes have to be developed. Especially long-term processes with radioactive materials have to be automated in early stages of development. This leads to a certain flexibility regarding requirements demanding an adjustable automation concept. The application of radiation hardened sensors is expensive but even these sensors will be destroyed by radiation effects. To allow therefore standard sensors to be used in radioactive environments, different strategies have been tested: In general, the sensors must be applied in a way to allow an easy access to sensors for replacement purposes. But this approach might not be sophisticated. An additional solution is the reduction of exposure of sensitive parts such as electronics. This means dividing the sensor in a measuring part which is placed in the radioactive environment and in a sensitive, shielded control part as it is realized by fibre optic sensors. The implementation of these approaches is demonstrated in sensor applications for radium handling systems e. g. contactless control of the needle clearance of a dispensing system via a fibre optic sensor. Further scenarios for sensor integration problems are presented in this paper.

  9. High-Level Radioactive Waste.

    ERIC Educational Resources Information Center

    Hayden, Howard C.

    1995-01-01

    Presents a method to calculate the amount of high-level radioactive waste by taking into consideration the following factors: the fission process that yields the waste, identification of the waste, the energy required to run a 1-GWe plant for one year, and the uranium mass required to produce that energy. Briefly discusses waste disposal and…

  10. Radioactivity and the Biology Teacher

    ERIC Educational Resources Information Center

    Hornsey, D. J.

    1974-01-01

    Discusses minimum necessary nuclear fundamentals of radioactive isotopes such as levels of activity, specific activity and the use of carrier materials. Corrections that need to be taken into account in using an isotope to obtain a valid result are also described and statistics for a valid result are included. (BR)

  11. 10 CFR 39.47 - Radioactive markers.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 39.47 Section 39.47 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.47 Radioactive markers. The licensee may use radioactive markers in wells only if the individual...

  12. 10 CFR 39.47 - Radioactive markers.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 39.47 Section 39.47 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.47 Radioactive markers. The licensee may use radioactive markers in wells only if the individual...

  13. 10 CFR 39.47 - Radioactive markers.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 39.47 Section 39.47 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.47 Radioactive markers. The licensee may use radioactive markers in wells only if the individual...

  14. 10 CFR 39.47 - Radioactive markers.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 39.47 Section 39.47 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.47 Radioactive markers. The licensee may use radioactive markers in wells only if the individual...

  15. 10 CFR 39.47 - Radioactive markers.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 39.47 Section 39.47 Energy NUCLEAR REGULATORY COMMISSION LICENSES AND RADIATION SAFETY REQUIREMENTS FOR WELL LOGGING Equipment § 39.47 Radioactive markers. The licensee may use radioactive markers in wells only if the individual...

  16. The Radioactive Beam Program at Argonne

    E-print Network

    B. B. Back

    2006-06-06

    In this talk I will present selected topics of the ongoing radioactive beam program at Argonne and discuss the capabilities of the CARIBU radioactive ion production facility as well as plans for construction of a novel superconducting solenoid spectrometer.

  17. Radioactive Iodine (I-131) Therapy for Hyperthyroidism

    MedlinePLUS

    ... with I-131. Depending on the amount of radioactivity administered during your treatment, your endocrinologist or radiation ... it begins destroying the gland's cells. Although the radioactivity from this treatment remains in the thyroid for ...

  18. Coal Ash Contains High Levels of Radioactivity

    MedlinePLUS

    ... 154590.html Coal Ash Contains High Levels of Radioactivity: Study End product from coal-fired plants may ... 2015 (HealthDay News) -- Coal ash contains levels of radioactivity that raise concern about the environment and human ...

  19. Radioactive Materials Post this where more than 1 EQ of radioactivity is being used.

    E-print Network

    Thompson, Michael

    Caution Radioactive Materials Post this where more than 1 EQ of radioactivity is being used. Caution Radioactive Materials Post this where more than 1 EQ of radioactivity is being used. User's Name: Activity: Date: Date: Form liquid solid gas Form liquid solid gas Exemption Quantities of common

  20. T : RADIOACTIVE-RETARDATION-REACTION-TRANSPORT-PROGRAM FOR THE SIMULATION OF RADIOACTIVE WASTE

    E-print Network

    Ewing, Richard E.

    R3 T : RADIOACTIVE-RETARDATION-REACTION-TRANSPORT- PROGRAM FOR THE SIMULATION OF RADIOACTIVE WASTE and reaction model for a potential waste scenarios of a radioactive waste-disposals. We introduce the complex the simulation of a waste scenario of a radioactive contaminant transport in flowing groundwater [4, 6]. The idea

  1. 46 CFR 147.100 - Radioactive materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 5 2010-10-01 2010-10-01 false Radioactive materials. 147.100 Section 147.100 Shipping COAST GUARD, DEPARTMENT OF HOMELAND SECURITY (CONTINUED) DANGEROUS CARGOES HAZARDOUS SHIPS' STORES Stowage and Other Special Requirements for Particular Materials § 147.100 Radioactive materials. (a) Radioactive materials must not be brought on...

  2. 2006 Nature Publishing Group Radioactive 26

    E-print Network

    California at Berkeley, University of

    © 2006 Nature Publishing Group Radioactive 26 Al from massive stars in the Galaxy Roland Diehl1-rays from radioactive 26 Al (half-life ,7.2 3 105 years) provide a `snapshot' view of continuing was apparently characterized3,4 by an amount of radioactive 26 Al (relative to the stable 27 Al isotope

  3. Total natural radioactivity, Tuscany, Italy Ivan Callegaria

    E-print Network

    Roma "La Sapienza", Università di

    SCIENCE Total natural radioactivity, Tuscany, Italy Ivan Callegaria , Gian Pietro Bezzonb , Carlo radioactive content of rocks of the Tuscany Region (Italy): this permitted the first total natural radioactivity map of the region. The sampling was planned using the geological map of Tuscany at scale 1

  4. Spills of Radioactive Materials -Emergency Procedures

    E-print Network

    Jia, Songtao

    Spills of Radioactive Materials - Emergency Procedures Procedure: 7.53 Created: 1/16/2014 Version for injured personnel. B. Applicability/scope This policy applies to all facilities where radioactive at 212- 305-8100 or 212-305-5-7979 and request Radiation Safety assistance. #12;Spills of Radioactive

  5. Radioactive Target Detection Using Wireless Sensor Network

    E-print Network

    Zhang, Tonglin

    Chapter 31 Radioactive Target Detection Using Wireless Sensor Network Tonglin Zhang Abstract The detection of radioactive target is becoming more important recently in public safety and national security can simultaneously detect and locate the radioactive target in the area. Our simulation results have

  6. RADIOACTIVE METALLOFULLERENES: HOT ATOM CHEMISTRY ASPECTS.

    E-print Network

    Titov, Anatoly

    RADIOACTIVE METALLOFULLERENES: HOT ATOM CHEMISTRY ASPECTS. Yu.S.Grushko, M.A. Khodorkovski, V, in radioactive form, endometallofullerenes become the subject of new branch of radiochemistry and materials studies and monitoring of 1 #12;chemical properties of metallofullerenes, in technology of radioactive

  7. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false Radioactive contamination. 175.705 Section 175.705... Regulations Applicable According to Classification of Material § 175.705 Radioactive contamination. (a) A... (radioactive) materials that may have been released from their packagings. (b) When contamination is present...

  8. Radioactive waste treatment technologies and environment

    SciTech Connect

    HORVATH, Jan; KRASNY, Dusan

    2007-07-01

    The radioactive waste treatment and conditioning are the most important steps in radioactive waste management. At the Slovak Electric, plc, a range of technologies are used for the processing of radioactive waste into a form suitable for disposal in near surface repository. These technologies operated by JAVYS, PLc. Nuclear and Decommissioning Company, PLc. Jaslovske Bohunice are described. Main accent is given to the Bohunice Radwaste Treatment and Conditioning Centre, Bituminization plant, Vitrification plant, and Near surface repository of radioactive waste in Mochovce and their operation. Conclusions to safe and effective management of radioactive waste in the Slovak Republic are presented. (authors)

  9. Public attitudes about radioactive waste

    SciTech Connect

    Bisconti, A.S.

    1992-12-31

    Public attitudes about radioactive waste are changeable. That is my conclusion from eight years of social science research which I have directed on this topic. The fact that public attitudes about radioactive waste are changeable is well-known to the hands-on practitioners who have opportunities to talk with the public and respond to their concerns-practitioners like Ginger King, who is sharing the podium with me today. The public`s changeability and open-mindedness are frequently overlooked in studies that focus narrowly on fear and dread. Such studies give the impression that the outlook for waste disposal solutions is dismal. I believe that impression is misleading, and I`d like to share research findings with you today that give a broader perspective.

  10. Radioactive waste shredding: Preliminary evaluation

    SciTech Connect

    Soelberg, N.R.; Reimann, G.A.

    1994-07-01

    The critical constraints for sizing solid radioactive and mixed wastes for subsequent thermal treatment were identified via a literature review and a survey of shredding equipment vendors. The types and amounts of DOE radioactive wastes that will require treatment to reduce the waste volume, destroy hazardous organics, or immobilize radionuclides and/or hazardous metals were considered. The preliminary steps of waste receipt, inspection, and separation were included because many potential waste treatment technologies have limits on feedstream chemical content, physical composition, and particle size. Most treatment processes and shredding operations require at least some degree of feed material characterization. Preliminary cost estimates show that pretreatment costs per unit of waste can be high and can vary significantly, depending on the processing rate and desired output particle size.

  11. Radioactive Waste Management BasisApril 2006

    SciTech Connect

    Perkins, B K

    2011-08-31

    This Radioactive Waste Management Basis (RWMB) documents radioactive waste management practices adopted at Lawrence Livermore National Laboratory (LLNL) pursuant to Department of Energy (DOE) Order 435.1, Radioactive Waste Management. The purpose of this Radioactive Waste Management Basis is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE Manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  12. Environmental Geochemistry of Radioactive Contamination

    NASA Astrophysics Data System (ADS)

    Siegel, M. D.; Bryan, C. R.

    2003-12-01

    Psychometric studies of public perception of risk have shown that dangers associated with radioactive contamination are considered the most dreaded and among the least understood hazards (Slovic, 1987). Fear of the risks associated with nuclear power and associated contamination has had important effects on policy and commercial decisions in the last few decades. In the US, no new nuclear power plants were ordered between 1978 and 2002, even though it has been suggested that the use of nuclear power has led to significantly reduced CO2 emissions and may provide some relief from the potential climatic changes associated with fossil fuel use. The costs of the remediation of sites contaminated by radioactive materials and the projected costs of waste disposal of radioactive waste in the US dwarf many other environmental programs. The cost of disposal of spent nuclear fuel at the proposed repository at Yucca Mountain will likely exceed 10 billion. The estimated total life cycle cost for remediation of US Department of Energy (DOE) weapons production sites ranged from 203-247 billion dollars in constant 1999 dollars, making the cleanup the largest environmental project on the planet (US DOE, 2001). Estimates for the cleanup of the Hanford site alone exceeded $85 billion through 2046 in some of the remediation plans.Policy decisions concerning radioactive contamination should be based on an understanding of the potential migration of radionuclides through the geosphere. In many cases, this potential may have been overestimated, leading to decisions to clean up contaminated sites unnecessarily and exposing workers to unnecessary risk. It is important for both the general public and the scientific community to be familiar with information that is well established, to identify the areas of uncertainty and to understand the significance of that uncertainty to the assessment of risk.

  13. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1989-09-30

    A program has been initiated to systematically study the structure of the very neutron-deficient nuclei in and near the region of deformation with Z > 50, N < 82. This has necessitated ion-source development. Radioactive decay is the only way to observe low-spin states in this region. Only with such information will details of the nuclear shape and nuclear stability in this new region of deformation be understood. This report discusses work done in this Z region.

  14. Nuclear structure from radioactive decay

    SciTech Connect

    Wood, J.L.

    1991-09-30

    This report discusses nuclear structure from radioactive decay of the following: Neutron-Deficient Iridium Isotopes; Neutron-Deficient Platinum Isotopes; Neutron-Deficient Gold Isotopes; Neutron-Deficient Mercury Isotopes; Neutron-Deficient Thallium Isotopes; Neutron-Deficient Lead Isotopes; Neutron-Deficient Samarium Isotopes; Neutron-Deficient Promethium Isotopes; Neutron-Deficient Neodymium Isotopes; and Neutron-Deficient Praseodymium Isotopes. Also discussed are Nuclear Systematics and Models.

  15. Disposition of intravenous radioactive acyclovir

    SciTech Connect

    de Miranda, P.; Good, S.S.; Laskin, O.L.; Krasny, H.C.; Connor, J.D.; Lietman, P.S.

    1981-11-01

    The kinetic and metabolic disposition of (8-14C)acyclovir (ACV) was investigated in five subjects with advanced malignancy. The drug was administered by 1-hr intravenous infusion at doses of 0.5 and 2.5 mg/kg. Plasma and blood radioactivity-time, and plasma concentration-time data were defined by a two-compartment open kinetic model. There was nearly equivalent distribution of radioactivity in blood and plasma. The overall mean plasma half-life and total body clearance +/- SD of ACV were 2.1 +/- 0.5 hr and 297 +/- 53 ml/min/1.73 m2. Binding of ACV to plasma proteins was 15.4 +/- 4.4%. Most of the radioactive dose excreted was recovered in the urine (71% to 99%) with less than 2% excretion in the feces and only trace amounts in the expired Co2. Analyses by reverse-phase high-performance liquid chromatography indicated that 9-(carboxymethoxymethyl)guanine was the only significant urinary metabolite of ACV, accounting for 8.5% to 14.1% of the dose. A minor metabolite (less than 0.2% of dose) had the retention time of 8-hydroxy-9-((2-hydroxyethoxy)methyl)guanine. Unchanged urinary ACV ranged from 62% to 91% of the dose. There was no indication of ACV cleavage to guanine. Renal clearance of ACV was approximately three times the corresponding creatinine clearances.

  16. Radioactivity of spent TRIGA fuel

    NASA Astrophysics Data System (ADS)

    Usang, M. D.; Nabil, A. R. A.; Alfred, S. L.; Hamzah, N. S.; Abi, M. J. B.; Rawi, M. Z. M.; Abu, M. P.

    2015-04-01

    Some of the oldest TRIGA fuel in the Malaysian Reaktor TRIGA PUSPATI (RTP) is approaching the limit of its end of life with burn-up of around 20%. Hence it is prudent for us to start planning on the replacement of the fuel in the reactor and other derivative activities associated with it. In this regard, we need to understand all of the risk associated with such operation and one of them is to predict the radioactivity of the fuel, so as to estimate the safety of our working conditions. The radioactivity of several fuels are measured and compared with simulation results to confirm the burnup levels of the selected fuels. The radioactivity measurement are conducted inside the water tank to reduce the risk of exposure and in this case the detector wrapped in plastics are lowered under water. In nuclear power plant, the general practice was to continuously burn the fuel. In research reactor, most operations are based on the immediate needs of the reactor and our RTP for example operate periodically. By integrating the burnup contribution for each core configuration, we simplify the simulation of burn up for each core configuration. Our results for two (2) fuel however indicates that the dose from simulation underestimate the actual dose from our measurements. Several postulates are investigated but the underlying reason remain inconclusive.

  17. Fractal Methods in Radioactivity Measurements.

    NASA Astrophysics Data System (ADS)

    Semkow, Thomas M.

    1996-10-01

    This work is in the category of applications of physics. We describe a concept of Minkowski volume (sausage) and show how an expectation value of a physical process can be calculated on a fractal object. These concepts are applied to the radioactivity in nature. The Minkowski volume is used to study the distribution of ^238U and ^232Th radioactive series as well as ^40K in environmental particles such as soils and coal fly ash.(T.M. Semkow, Environ. Intern. (1996) to be published.) The surface and internal radioactivity concentrations are obtained from the fits to experimental data, in addition to the fractal dimensions of the surfaces and thicknesses of the surface layers. We also study ^222Rn emanation from solid materials and show that the radon emanating power is proportional to V(R), where V is the Minkowski volume and R is the ?-recoil range from the decay of ^226Ra, if Ra is distributed uniformly in the solid. (T.M. Semkow, Phys. Rev. Lett. 66 (1991) 3012.) The dependence of emanating power on surface roughness and Ra distribution is also discussed.

  18. Radioactivity of spent TRIGA fuel

    SciTech Connect

    Usang, M. D. Nabil, A. R. A.; Alfred, S. L.; Hamzah, N. S.; Abi, M. J. B.; Rawi, M. Z. M.; Abu, M. P.

    2015-04-29

    Some of the oldest TRIGA fuel in the Malaysian Reaktor TRIGA PUSPATI (RTP) is approaching the limit of its end of life with burn-up of around 20%. Hence it is prudent for us to start planning on the replacement of the fuel in the reactor and other derivative activities associated with it. In this regard, we need to understand all of the risk associated with such operation and one of them is to predict the radioactivity of the fuel, so as to estimate the safety of our working conditions. The radioactivity of several fuels are measured and compared with simulation results to confirm the burnup levels of the selected fuels. The radioactivity measurement are conducted inside the water tank to reduce the risk of exposure and in this case the detector wrapped in plastics are lowered under water. In nuclear power plant, the general practice was to continuously burn the fuel. In research reactor, most operations are based on the immediate needs of the reactor and our RTP for example operate periodically. By integrating the burnup contribution for each core configuration, we simplify the simulation of burn up for each core configuration. Our results for two (2) fuel however indicates that the dose from simulation underestimate the actual dose from our measurements. Several postulates are investigated but the underlying reason remain inconclusive.

  19. Radioactive characterization of the main materials involved in the titanium dioxide production process and their environmental radiological impact.

    PubMed

    Mantero, J; Gazquez, M J; Bolivar, J P; Garcia-Tenorio, R; Vaca, F

    2013-06-01

    A study about the distribution of several radionuclides from the uranium and the thorium series radionuclides along the production process of a typical NORM industry devoted to the production of titanium dioxide has been performed. With this end the activity concentrations in raw materials, final product, co-products, and wastes of the production process have been determined by both gamma-ray and alpha-particle spectrometry. The main raw material used in the studied process (ilmenite) presents activity concentrations of around 300 Bq kg(-1) for Th-series radionuclides and 100 Bq kg(-1) for the U-series ones. These radionuclides in the industrial process are distributed in the different steps of the production process according mostly to the chemical behaviour of each radioelement, following different routes. As an example, most of the radium remains associated with the un-dissolved material waste, with activity concentrations around 3 kBq kg(-1) of (228)Ra and around 1 kBq kg(-1) of (226)Ra, while the final commercial products (TiO2 pigments and co-products) contain negligible amounts of radioactivity. The obtained results have allowed assessing the possible public radiological impact associated with the use of the products and co-products obtained in this type of industry, as well as the environmental radiological impact associated with the solid residues and liquid generated discharges. PMID:23416226

  20. U-Th disequilibria constraints on physical and chemical erosion processes and rates in soils from the Lake Natron-Lake Magadi (Gregory Rift Valley) drainage area vs hydrology/paleohydrology and bedrock lithology

    NASA Astrophysics Data System (ADS)

    Hillaire-Marcel, Claude

    2015-04-01

    This presentation is a tribute to my former PhD student, the late Dr. Christian Goetz (1960-1991), who carried out intensive field and laboratory investigations on actinides in soils and sediments from lakes Manyara and Natron (Tanzania), and Magadi (Kenya) during his doctoral studies. Soils developed on granites from the Precambrian plateau, west of Gregory Rift, as well as those developed on the trachitic floor of the Rift yield nearly similar patterns, with U-leached (and Th-enriched) upper horizons vs source rocks. They differ from each other by i) the much higher [U]/[Th] mass ratio of soil over the granitic (~ 0.3) vs the trachitic (~ 0.1) basements (both near secular equilibrium), and ii) the greater decay of 230Th-excesses (230Thxs) in top soils over trachites, pointing to much older soils and/or lower leaching rates at the Rift floor. This difference seems related to the more arid conditions prevailing in the deeper part of the Rift. In contrast, soils developed on the basaltic walls of the Rift, characterized by abundant spring water from the basalt aquifer and a dense vegetation, depict a three-stage U-Th isotope evolution, with bedrock at near secular radioactive equilibrium and a [U]/[Th] ratio of ~ 0.2. It is overlain by a U-depleted horizon (with up to 75% relative losses in U), then topped by a low Eh, organic-matter rich layer, with evidence for a secondary uptake of U. The high 230Thxs observed in the U-leached horizon point to relatively fast U-leaching rates and/or "young" soil pattern. The present-day clays deposited in Lake Natron point to a Precambrian granitic plateau origin (through major rivers flowing eastwards towards the lake), whereas clay supplies from the rift escarpment basalts are carried with hydrothermal seepages towards Lake Magadi. U-Th measurements in early diagenetic minerals (phosphates) and clays (smectites) deposited during late Pleistocene high-lake levels (? 12 ka BP) provide robust constraints on source-rocks and source minerals, as well as on their paleodrainage patterns and depositional age.

  1. Radioactivity

    SciTech Connect

    Baratta, E.J.

    1996-01-01

    This report of the General Referee was presented at the 109th AOAC International Annual Meeting, September 17-21, 1995 in Nashville, Tennessee. The author reports the standing of the review process for six methods concerned with the analysis of radionuclides in foods or the environment.

  2. Radioactivity

    SciTech Connect

    Baratta, E.J.

    1997-01-01

    Cesium-134 and -137 in Foods, Gamma-Ray Spectrophotometric Methods. The method entitled {open_quotes}Cs-134 and Cs-137 in Foods, Gamma-Ray Spectrophotometric Method{close_quotes} has been adopted official first action, with minor revisions. Iodine 131: The method {open_quotes}Iodine-131 in Milk, Radiochemical Separation Method{close_quotes} has been accepted by the Committee on Residues and Related Topics and has been recommended to the Methods Committee for adoption first action. Search is continuing for a new Associated Referee. Plutonium-239: The Associate Referee is doing a literature search for a method for the determination of plutonium in foods. When one is selected, she will prepared a protocol for a collaborative study and submit it for approval. Radium-228: Search is ongoing for a new Associate Referee. When one is appointed, a method should be selected and tested. Strontium-89 and -90: The Associate Referee is investigating methods using resin discs and/or resin columns for these radionuclides. These methods are now being used in analyses for strontium-89 and -90 in water. She will now attempt to apply it to milk. If successful, she will prepare a protocol for a collaborative study and submit it for approval. Tritium: Search is continuing for a new Associate Referee for this topic.

  3. Radioactivity

    SciTech Connect

    Baratta, E.J.

    1987-01-01

    This report of the General Referee was presented at the 100th AOAC Annual International Meeting, Sept. 15-18, 1986, at Scottsdale, AZ. The method for determining cesium-137 and iodine-131 in milk and other foods by gamma-ray spectroscopy has been adopted official first action. Results have been received from 5 collaborators. A sixth collaborator was found and is in the process of analyzing the sample. When all results are in, the Associate Referee will perform a statistical analysis of the data. Other topics of interest include; plutonium; radium-228; and strontium-89 and -90. Recommendations are included which were reviewed by the Committee on Residues.

  4. Radioactive Waste Management BasisSept 2001

    SciTech Connect

    Goodwin, S S

    2011-08-31

    This Radioactive Waste Management Basis (RWMB) documents radioactive waste management practices adopted at Lawrence Livermore National Laboratory (LLNL) pursuant to Department of Energy (DOE) Order 435.1, Radioactive Waste Management. The purpose of this RWMB is to describe the systematic approach for planning, executing, and evaluating the management of radioactive waste at LLNL. The implementation of this document will ensure that waste management activities at LLNL are conducted in compliance with the requirements of DOE Order 435.1, Radioactive Waste Management, and the Implementation Guide for DOE manual 435.1-1, Radioactive Waste Management Manual. Technical justification is provided where methods for meeeting the requirements of DOE Order 435.1 deviate from the DOE Manual 435.1-1 and Implementation Guide.

  5. The Model 9977 Radioactive Material Packaging Primer

    SciTech Connect

    Abramczyk, G.

    2015-10-09

    The Model 9977 Packaging is a single containment drum style radioactive material (RAM) shipping container designed, tested and analyzed to meet the performance requirements of Title 10 the Code of Federal Regulations Part 71. A radioactive material shipping package, in combination with its contents, must perform three functions (please note that the performance criteria specified in the Code of Federal Regulations have alternate limits for normal operations and after accident conditions): Containment, the package must “contain” the radioactive material within it; Shielding, the packaging must limit its users and the public to radiation doses within specified limits; and Subcriticality, the package must maintain its radioactive material as subcritical

  6. Non-radioactive stand-in for radioactive contamination. I. Non-radioactive tests. [High-pressure, hot water decontamination

    SciTech Connect

    Rohe, M.J.; Rankin, W.N.; Postles, R.L.

    1985-10-08

    Candidate non-radioactive materials for use as a stand-in for radioactive contamination during application of a high-pressure, hot water decontamination were identified and evaluated. A stand-in for radioactive contamination is needed to evaluate the decontaminability of replacement canyon cranes at the manufacturers location where actual radioactive contamination cannot be used. This evaluation was conducted using high-pressure, hot-water at 420 psi, 190/sup 0/F, and 20 gal/min through a 1/8-in.-diam nozzle, the decontamination technique preferred by SRP Separations Department for this application. A non-radioactive stand-in for radioactive contamination was desired that would be removed by direct blast stream contact but would remain intact on surfaces where direct contact does not occur. This memorandum describes identification of candidate non-radioactive stand-in materials and evaluation of these materials in screening tests and tests with high-pressure, hot-water blasting. The following non-radioactive materials were tested: carpenter's line chalk; typing correction fluid; dye penetrant developer; latex paint with attapulyite added; unaltered latex paint; gold enamel; layout fluid; and black enamel. Results show that blue layout fluid and gold enamel have similar adherence that is within the range expected for actual radioactive contamination. White latex paint has less adherence than expected for actual radioactive contamination. The film was removed at a rate of <1 sec/in./sup 2/. Black enamel has more adherence than expected from actual radioactive contamination. In these tests ASTM No. 2B surfaces were harder to clean than either ASTM No. 1 or electropolished surfaces which had similar cleaning properties. A 90/sup 0/ blast angle was more effective than a 45/sup 0/ blast angle. In these tests there was no discernible effect of blast distance between 1 and 3 ft.

  7. Charge Breeding of Radioactive Ions

    E-print Network

    Wenander, F J C

    2013-01-01

    Charge breeding is a technique to increase the charge state of ions, in many cases radioactive ions. The singly charged radioactive ions, produced in an isotope separator on-line facility, and extracted with a low kinetic energy of some tens of keV, are injected into a charge breeder, where the charge state is increased to Q. The transformed ions are either directed towards a dedicated experiment requiring highly charged ions, or post-accelerated to higher beam energies. In this paper the physics processes involved in the production of highly charged ions will be introduced, and the injection and extraction beam parameters of the charge breeder defined. A description of the three main charge-breeding methods is given, namely: electron stripping in gas jet or foil; external ion injection into an electron-beam ion source/trap (EBIS/T); and external ion injection into an electron cyclotron resonance ion source (ECRIS). In addition, some preparatory devices for charge breeding and practical beam delivery aspects ...

  8. Radioactivity in the galactic plane

    NASA Technical Reports Server (NTRS)

    Walraven, G. D.; Haymes, R. C.

    1976-01-01

    The paper reports the detection of a large concentration of interstellar radioactivity during balloon-altitude measurements of gamma-ray energy spectra in the band between 0.02 and 12.27 MeV from galactic and extragalactic sources. Enhanced counting rates were observed in three directions towards the plane of the Galaxy; a power-law energy spectrum is computed for one of these directions (designated B 10). A large statistical deviation from the power law in a 1.0-FWHM interval centered near 1.16 MeV is discussed, and the existence of a nuclear gamma-ray line at 1.15 MeV in B 10 is postulated. It is suggested that Ca-44, which emits gamma radiation at 1.156 MeV following the decay of radioactive Sc-44, is a likely candidate for this line, noting that Sc-44 arises from Ti-44 according to explosive models of supernova nucleosynthesis. The 1.16-MeV line flux inferred from the present data is shown to equal the predicted flux for a supernova at a distance of approximately 3 kpc and an age not exceeding about 100 years.

  9. Induced radioactivity in LDEF components

    NASA Technical Reports Server (NTRS)

    Harmon, B. A.; Fishman, G. J.; Parnell, T. A.; Laird, C. E.

    1991-01-01

    The systematics of induced radioactivity on the Long Duration Exposure Facility (LDEF) were studied in a wide range of materials using low level background facilities for detection of gamma rays. Approx. 400 samples of materials processed from structural parts of the spacecraft, as well as materials from onboard experiments, were analyzed at national facilities. These measurements show the variety of radioisotopes that are produced with half-lives greater than 2 wks, most of which are characteristic of proton induced reactions above 20 MeV. For the higher activity, long lived isotopes, it was possible to map the depth and directional dependences of the activity. Due to the stabilized configuration of the LDEF, the induced radioactivity data clearly show contributions from the anisotropic trapped proton flux in the South Atlantic Anomaly. This effect is discussed, along with evidence for activation by galactic protons and thermal neutrons. The discovery of Be-7 was made on leading side parts of the spacecraft, although this was though not to be related to the in situ production of radioisotopes from external particle fluxes.

  10. Cosmic radioactivity and INTEGRAL results

    SciTech Connect

    Diehl, Roland

    2014-05-02

    Gamma-ray lines from radioactive decay of unstable isotopes co-produced by nucleosynthesis in massive stars and supernova have been measured since more than thirty years. Over the past ten years, INTEGRAL complemented the first sky survey made by COMPTEL. The {sup 26}A1 isotope with 1 My decay time had been first direct proof of currently-ongoing nucleosynthesis in our Galaxy. This has now become a tool to study the ?My history of specific source regions, such as massive-star groups and associations in nearby regions which can be discriminated from the galactic-plane background, and the inner Galaxy, where Doppler shifted lines add to the astronomical information about bar and spiral structure. Recent findings suggest that superbubbles show a remarkable asymmetry, on average, in the spiral arms of our galaxy. {sup 60}Fe is co-produced by the sources of {sup 26}A1, and the isotopic ratio from their nucleosynthesis encodes stellar-structure information. Annihilation gamma-rays from positrons in interstellar space show a puzzling bright and extended source region central to our Galaxy, but also may be partly related to nucleosynthesis. {sup 56}Ni and {sup 44}Ti isotope gamma-rays have been used to constrain supernova explosion mechanisms. Here we report latest results using the accumulated multi-year database of INTEGRAL observations, and discuss their astrophysical interpretations, connecting to other traces of cosmic radioactivity and to other cosmic messengers.

  11. Magic radioactivity of 252Cf

    E-print Network

    M. Mirea; D. S. Delion; A. Sandulescu

    2010-03-31

    We show that the sharp maximum corresponding to 107Mo in the fragment distribution of the 252Cf cold fission is actually a Sn-like radioactivity, similar to other decay processes in which magic nuclei are involved, namely alpha-decay and heavy cluster emission, also called Pb-like radioactivity. It turns out that the mass asymmetry degree of freedom has a key role in connecting initial Sn with the final Mo isotopes along the fission path. We suppose the cold rearrangement of nucleons within the framework of the two center shell model, in order to compute the cold valleys in the charge equilibrated fragmentation potential. The fission yields are estimated by using the semiclassical penetration approach. We consider five degrees of freedom, namely the inter-fragment distance, the shapes of fragments, the neck parameter and mass asymmetry. We found an isomeric minimum between the internal and external barriers. It turns out that the inner cold valley of the total potential energy is connected to the double magic isotope 132Sn

  12. Radiation Awareness TrainingRadiation Awareness Training Radioactive Material &Radioactive Material &

    E-print Network

    Li, Mo

    Radiation Awareness TrainingRadiation Awareness Training Radioactive Material &Radioactive Material A ­ Authorization to Faculty member ­ Reviewed by Radiation Safety Committee ­ For Radioactive Materials and X sources · Training of PIs and radiation workers · Annual surveys of x-ray machines · Emergency response

  13. MARSAME Appendix B B. SOURCES OF BACKGROUND RADIOACTIVITY

    E-print Network

    MARSAME Appendix B B. SOURCES OF BACKGROUND RADIOACTIVITY B.1 Introduction Background radioactivity can complicate the disposition decision for M&E. Background radioactivity may be the result of environmental radioactivity, inherent radioactivity, instrument noise, or some combination of the three. Special

  14. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  15. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  16. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  17. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  18. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area. (e) Contamination area. The words...

  19. Entry Survey for Laboratories Using Radioactive Materials

    E-print Network

    Jia, Songtao

    -Doherty Earth Observatory). This committee supervises and oversees the use of radioactive materials-Doherty Earth Observatory). Please include the name of the PI, permit number, and the building and room number/items will be evaluated: Locations, benches and equipment designated for radioactive material use will be established

  20. Disposal of Specific Articles Containing Radioactive Materials

    E-print Network

    Jia, Songtao

    Disposal of Specific Articles Containing Radioactive Materials Procedure: 8.24 Version 1.0 Effective Date: 10/14/2014 Page 1 of 4 A. Purpose To ensure that all exit signs containing tritium (H-3 containing radioactive materials 2. Identification of found or existing manufactured articles

  1. Pb-Radioactivity in superheavy elements

    E-print Network

    Sushil Kumar

    2011-10-24

    The Pb-radioactivity in the superheavy mass region is studied within the frame work of PCM model,the calculation of Pb-Radioactivity looks favorably for the cluster decay studies in superheavy mass region as in the heavy mass region.

  2. The safe disposal of radioactive wastes

    PubMed Central

    Kenny, A. W.

    1956-01-01

    A comprehensive review is given of the principles and problems involved in the safe disposal of radioactive wastes. The first part is devoted to a study of the basic facts of radioactivity and of nuclear fission, the characteristics of radioisotopes, the effects of ionizing radiations, and the maximum permissible levels of radioactivity for workers and for the general public. In the second part, the author describes the different types of radioactive waste—reactor wastes and wastes arising from the use of radioisotopes in hospitals and in industry—and discusses the application of the maximum permissible levels of radioactivity to their disposal and treatment, illustrating his discussion with an account of the methods practised at the principal atomic energy establishments. PMID:13374534

  3. Production of high intensity radioactive beams

    SciTech Connect

    Nitschke, J.M.

    1990-04-01

    The production of radioactive nuclear beams world-wide is reviewed. The projectile fragmentation and the ISOL approaches are discussed in detail, and the luminosity parameter is used throughout to compare different production methods. In the ISOL approach a thin and a thick target option are distinguished. The role of storage rings in radioactive beam research is evaluated. It is concluded that radioactive beams produced by the projectile fragmentation and the ISOL methods have complementary characteristics and can serve to answer different scientific questions. The decision which kind of facility to build has to depend on the significance and breadth of these questions. Finally a facility for producing a high intensity radioactive beams near the Coulomb barrier is proposed, with an expected luminosity of {approximately}10{sup 39} cm{sup {minus}2} s{sup {minus}1}, which would yield radioactive beams in excess of 10{sup 11} s{sup {minus}1}. 9 refs., 3 figs., 7 tabs.

  4. Apparatus and method for radioactive waste screening

    DOEpatents

    Akers, Douglas W.; Roybal, Lyle G.; Salomon, Hopi; Williams, Charles Leroy

    2012-09-04

    An apparatus and method relating to screening radioactive waste are disclosed for ensuring that at least one calculated parameter for the measurement data of a sample falls within a range between an upper limit and a lower limit prior to the sample being packaged for disposal. The apparatus includes a radiation detector configured for detecting radioactivity and radionuclide content of the of the sample of radioactive waste and generating measurement data in response thereto, and a collimator including at least one aperture to direct a field of view of the radiation detector. The method includes measuring a radioactive content of a sample, and calculating one or more parameters from the radioactive content of the sample.

  5. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2012-07-01 false Radioactive waste injection wells. 147.3005...Mexico Tribes § 147.3005 Radioactive waste injection wells. Notwithstanding...of wells used to dispose of radioactive waste (as defined in 10 CFR...

  6. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 2014-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

  7. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 2013-07-01 false Radioactive waste injection wells. 147.3005...Mexico Tribes § 147.3005 Radioactive waste injection wells. Notwithstanding...of wells used to dispose of radioactive waste (as defined in 10 CFR...

  8. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 2011-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

  9. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 2010-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

  10. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... 2013-07-01 false High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

  11. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 2014-07-01 false Radioactive waste injection wells. 147.3005...Mexico Tribes § 147.3005 Radioactive waste injection wells. Notwithstanding...of wells used to dispose of radioactive waste (as defined in 10 CFR...

  12. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 2010-07-01 false Radioactive waste injection wells. 147.3005...Mexico Tribes § 147.3005 Radioactive waste injection wells. Notwithstanding...of wells used to dispose of radioactive waste (as defined in 10 CFR...

  13. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 2011-07-01 false Radioactive waste injection wells. 147.3005...Mexico Tribes § 147.3005 Radioactive waste injection wells. Notwithstanding...of wells used to dispose of radioactive waste (as defined in 10 CFR...

  14. 10 CFR 76.83 - Transfer of radioactive material.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...radioactive material. 76.83 Section 76.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.83 Transfer of radioactive material. (a) The Corporation may not transfer radioactive...

  15. 10 CFR 76.83 - Transfer of radioactive material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...radioactive material. 76.83 Section 76.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.83 Transfer of radioactive material. (a) The Corporation may not transfer radioactive...

  16. 10 CFR 76.83 - Transfer of radioactive material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...radioactive material. 76.83 Section 76.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.83 Transfer of radioactive material. (a) The Corporation may not transfer radioactive...

  17. 10 CFR 76.83 - Transfer of radioactive material.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...radioactive material. 76.83 Section 76.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.83 Transfer of radioactive material. (a) The Corporation may not transfer radioactive...

  18. 40 CFR 141.25 - Analytical methods for radioactivity.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...2010-07-01 false Analytical methods for radioactivity. 141.25 Section 141.25 ...141.25 Analytical methods for radioactivity. (a) Analysis for the following...determine compliance with § 141.66 (radioactivity) in accordance with the...

  19. 40 CFR 141.25 - Analytical methods for radioactivity.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 false Analytical methods for radioactivity. 141.25 Section 141.25 ...141.25 Analytical methods for radioactivity. (a) Analysis for the following...determine compliance with § 141.66 (radioactivity) in accordance with the...

  20. 40 CFR 141.25 - Analytical methods for radioactivity.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...2011-07-01 false Analytical methods for radioactivity. 141.25 Section 141.25 ...141.25 Analytical methods for radioactivity. (a) Analysis for the following...determine compliance with § 141.66 (radioactivity) in accordance with the...

  1. 40 CFR 141.25 - Analytical methods for radioactivity.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...2014-07-01 false Analytical methods for radioactivity. 141.25 Section 141.25 ...141.25 Analytical methods for radioactivity. (a) Analysis for the following...determine compliance with § 141.66 (radioactivity) in accordance with the...

  2. 40 CFR 141.25 - Analytical methods for radioactivity.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...2013-07-01 false Analytical methods for radioactivity. 141.25 Section 141.25 ...141.25 Analytical methods for radioactivity. (a) Analysis for the following...determine compliance with § 141.66 (radioactivity) in accordance with the...

  3. 10 CFR 76.83 - Transfer of radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...radioactive material. 76.83 Section 76.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.83 Transfer of radioactive material. (a) The Corporation may not transfer radioactive...

  4. Film Badge Application Radioactive Material Package Receipt Log

    E-print Network

    Slatton, Clint

    ;RADIOACTIVE MATERIAL PACKAGE RECEIPT LOG DATE: DELIVERED BY: AUTHORIZED BY: Contamination Check DPM/100 cm2APPENDIX A Film Badge Application Radioactive Material Package Receipt Log Radioactive Material's supervisor declaring pregnancy and approximate date of conception. PRINT NAME

  5. Ordering, Receipt and Delivery of Packages Containing Radioactive

    E-print Network

    Jia, Songtao

    Ordering, Receipt and Delivery of Packages Containing Radioactive Materials for Research Procedure Ordering, Receipt and Delivery of Packages Containing Radioactive Materials for Research A. Purpose Radiation Safety will approve all orders for and receive all packages containing radioactive materials

  6. Rev August 2006 Radiation Safety Manual Section 14 Radioactive Waste

    E-print Network

    Sniadecki, Nathan J.

    Rev August 2006 Radiation Safety Manual Section 14 ­ Radioactive Waste Page 14-1 Section 14 Radioactive Waste Contents A. Proper Collection, Disposal, and Packaging and Putrescible Animal Waste.........................14-8 a. Non-Radioactive Animal Waste

  7. Method for immobilizing radioactive iodine

    DOEpatents

    Babad, Harry (Richland, WA); Strachan, Denis M. (Richland, WA)

    1980-01-01

    Radioactive iodine, present as alkali metal iodides or iodates in an aqueous solution, is incorporated into an inert solid material for long-term storage by adding to the solution a stoichiometric amount with respect to the formation of a sodalite (3M.sub.2 O.3Al.sub.2 O.sub.3. 6SiO.sub.2.2MX, where M=alkali metal; X=I.sup.- or IO.sub.3.sup.-) of an alkali metal, alumina and silica, stirring the solution to form a homogeneous mixture, drying the mixture to form a powder, compacting and sintering the compacted powder at 1073 to 1373 K (800.degree. to 1100.degree. C.) for a time sufficient to form sodalite.

  8. Diverter assembly for radioactive material

    DOEpatents

    Andrews, K.M.; Starenchak, R.W.

    1988-04-11

    A diverter assembly for diverting a pneumatically conveyed holder for a radioactive material between a central conveying tube and one of a plurality of radially offset conveying tubes includes an airtight container. A diverter tube having an offset end is suitably mounted in the container for rotation. A rotary seal seals one end of the diverter tube during and after rotation of the diverter tube while a spring biased seal seals the other end of the diverter tube which moves between various offset conveying tubes. An indexing device rotatably indexes the diverter tube and this indexing device is driven by a suitable drive. The indexing mechanism is preferably a geneva-type mechanism to provide a locking of the diverter tube in place. 3 figs.

  9. System for radioactive waste cementation

    SciTech Connect

    Dmitriev, S.A.; Barinov, A.S.; Varlakov, A.P.; Volkov, A.S.; Karlin, S.V.

    1995-12-31

    NPP, research reactors and radiochemical enterprises produce a great amount of liquid radioactive waste (LRW). One of the methods of LRW solidification is cementation. The recent investigations demonstrated possible inclusion of sufficient amount of waste in the cement matrix (up to 20--30 mass% on dry residue). In this case the cementation process becomes competitive with bituminization process, where the matrix can include 40--50 mass% and the solidified product volume is equal to the volume, obtained by cementation. Additionally, the cement matrix in contrast with the bituminous one is unburnable. Many countries are investigating the cementation process. The main idea governing technological process is the waste and cement mixing method and type of mixer. In world practice some principal types of cementation systems are used. The paper describes the SIA Radon industrial plant in Moscow.

  10. Radioactive effluents in Savannah River

    SciTech Connect

    Winn, W.G.

    1991-11-27

    During 1990, low-level radiometric studies of the Savannah River continued to distinguish between effluent contributions from Plant Vogtle and the Savannah River Site. Measurements of these radioactive effluents are of mutual interest to both institutions, as they can address disturbing trends before they become health and legal concerns. The Environmental Technology Section (ETS) has conducted radiometric studies of Plant Vogtle since late 1986, prior to its startup. The plant has two 1100 MWe pressurized water reactors developed by Westinghouse. Unit 1 started commercial operations in June 1987, and Unit 2 began in May 1989. During powered operations, ETS has routinely detected neutron-activated isotopes in controlled releases but all activities have been several orders of magnitude below the DOE guide values. In 1990, processing improvements for Vogtle effluents have yielded even lower activities in the river. The Vogtle release data and the ETS measurements have tracked well over the past four years.

  11. Microbiological treatment of radioactive wastes

    SciTech Connect

    Francis, A.J.

    1992-12-31

    The ability of microorganisms which are ubiquitous throughout nature to bring about information of organic and inorganic compounds in radioactive wastes has been recognized. Unlike organic contaminants, metals cannot be destroyed, but must be either removed or converted to a stable form. Radionuclides and toxic metals in wastes may be present initially in soluble form or, after disposal may be converted to a soluble form by chemical or microbiological processes. The key microbiological reactions include (i) oxidation/reduction; (ii) change in pH and Eh which affects the valence state and solubility of the metal; (iii) production of sequestering agents; and (iv) bioaccumulation. All of these processes can mobilize or stabilize metals in the environment.

  12. Influence of Radioactivity on Surface Interaction Forces

    SciTech Connect

    Walker, Mark E; McFarlane, Joanna; Glasgow, David C; Chung, Eunhyea; Taboada Serrano, Patricia L; Yiacoumi, Sotira; Tsouris, Costas

    2010-01-01

    Although some differences have been observed, the transport behavior of radioactive aerosol particles has often been assumed to be analogous to the behavior of nonradioactive aerosols in dispersion models. However, radioactive particles can become electrostatically charged as a result of the decay process. Theories have been proposed to describe this self-charging phenomenon, which may have a significant effect on how these particles interact with one another and with charged surfaces in the environment. In this study, atomic force microscopy (AFM) was employed to quantify surface forces between a particle and a planar surface and to compare measurements with and without the involvement of radioactivity. The main objective of this work is to assess directly the effects of radioactivity on the surface interactions of radioactive aerosols via the measurement of the adhesion force. The adhesion force between a silicon nitride AFM tip and an activated gold substrate was measured so that any possible effects due to radioactivity could be observed. The adhesion force between the tip and the gold surface increased significantly when the gold substrate (25 mm{sup 2} surface area) was activated to a level of approximately 0.6 mCi. The results of this investigation will prompt further work into the effects of radioactivity in particle-surface interactions.

  13. Radioactive anomaly discrimination from spectral ratios

    DOEpatents

    Maniscalco, James; Sjoden, Glenn; Chapman, Mac Clements

    2013-08-20

    A method for discriminating a radioactive anomaly from naturally occurring radioactive materials includes detecting a first number of gamma photons having energies in a first range of energy values within a predetermined period of time and detecting a second number of gamma photons having energies in a second range of energy values within the predetermined period of time. The method further includes determining, in a controller, a ratio of the first number of gamma photons having energies in the first range and the second number of gamma photons having energies in the second range, and determining that a radioactive anomaly is present when the ratio exceeds a threshold value.

  14. Evaluation of Terrorist Interest in Radioactive Wastes

    SciTech Connect

    McFee, J.N.; Langsted, J.M.; Young, M.E.; Day, J.E.

    2006-07-01

    Since September 11, 2001, intelligence gathered from Al Qaeda training camps in Afghanistan, and the ensuing terrorist activities, indicates nuclear material security concerns are valid. This paper reviews available information on sealed radioactive sources thought to be of interest to terrorists, and then examines typical wastes generated during environmental management activities to compare their comparative 'attractiveness' for terrorist diversion. Sealed radioactive sources have been evaluated in numerous studies to assess their security and attractiveness for use as a terrorist weapon. The studies conclude that tens of thousands of curies in sealed radioactive sources are available for potential use in a terrorist attack. This risk is mitigated by international efforts to find lost and abandoned sources and bring them under adequate security. However, radioactive waste has not received the same level of scrutiny to ensure security. This paper summarizes the activity and nature of radioactive sources potentially available to international terrorists. The paper then estimates radiation doses from use of radioactive sources as well as typical environmental restoration or decontamination and decommissioning wastes in a radioactive dispersal device (RDD) attack. These calculated doses indicate that radioactive wastes are, as expected, much less of a health risk than radioactive sources. The difference in radiation doses from wastes used in an RDD are four to nine orders of magnitude less than from sealed sources. We then review the International Atomic Energy Agency (IAEA) definition of 'dangerous source' in an adjusted comparison to common radioactive waste shipments generated in environmental management activities. The highest waste dispersion was found to meet only category 1-3.2 of the five step IAEA scale. A category '3' source by the IAEA standard 'is extremely unlikely, to cause injury to a person in the immediate vicinity'. The obvious conclusion of the analysis is that environmental management generated radioactive wastes have substantially less impact than radioactive sources if dispersed by terrorist-induced explosion or fire. From a health standpoint, the impact is very small. However, there is no basis to conclude that wastes are totally unattractive for use in a disruptive or economic damage event. Waste managers should be cognizant of this potential and take measures to ensure security of stored waste and waste shipments. (authors)

  15. [CME: Radioactive iodine therapy in thyroid cancer].

    PubMed

    Steinert, Hans C; Aberle, Susanne

    2015-11-11

    Differentiated thyroid carcinomas represent about 90% of all thyroid tumors and are divided in papillary and follicular carcinomas. Their prognosis is good, however, recurrences are not rare. Their ability to accumulate iodine is used for the radioactive iodine treatment. The aim of the postoperative radioactive iodine ablation therapy is the complete elimination of remnant thyroid cells and sensitive staging (Fig. 1). The recurrence rate decreases after a complete thyroid ablation. Furthermore, thyroglobulin can be used as a sensitive tumor marker. Radioactive iodine treatment by itself describes the therapy of metastases. An exception is the papillary microcarcinoma, which in general is treated by a lobectomy alone. PMID:26558927

  16. Science with radioactive beams: the alchemist's dream

    NASA Astrophysics Data System (ADS)

    Gelletly, W.

    2001-05-01

    Nuclear science is being transformed by a new capacity to create beams of radioactive nuclei. Until now all of our knowledge of nuclear physics and the applications which flow from it has been derived from studies of radioactive decay and nuclear reactions induced by beams of the 283 stable or long-lived nuclear species we can find on Earth. Here we describe first how beams of radioactive nuclei can be created. The present status of nuclear physics is then reviewed before potential applications to nuclear physics, nuclear astrophysics, materials science, bio-medical, and environmental studies are described.

  17. Radioactivities related to coal mining.

    PubMed

    Seddeek, Mostafa K; Sharshar, Taher; Ragab, Hossam S; Badran, Hussein M

    2005-08-01

    Natural radioactivity concentrations due to the coal mining in Gabal El-Maghara, North Sinai, Egypt, were determined using gamma-ray spectroscopy. Coal, water and soil samples were investigated in this study. The (226)Ra, (232)Th and (40)K activity concentrations in coal before extraction were 18.5 +/- 0.5, 29.5 +/- 1.2 and 149.0 +/- 8.4 Bq kg(-1), respectively. These concentrations were reduced to 18-22% after extraction due to the clay removal of the coal ore. The activity contents of the water and soil samples collected from the surrounding area did not show any evidence of enhancement due to the mining activities. Absorbed dose rate and effective dose equivalent in the mine environment were 29.4 nGy h(-1) and 128.0 microSv a(-1), respectively. The measured activity concentrations in the mine environment and the surrounding areas (5 km away from the mine) are similar to that found in other regions in North and South Sinai. Based on the measurements of gamma-ray emitting radionuclides, the mine activity does not lead to any enhancement in the local area nor represents any human risk. PMID:16049576

  18. Is Radioactive Decay Really Exponential?

    E-print Network

    Aston, Philip J

    2012-01-01

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12,550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3,000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating meth...

  19. Is Radioactive Decay Really Exponential?

    E-print Network

    Philip J. Aston

    2012-04-26

    Radioactive decay of an unstable isotope is widely believed to be exponential. This view is supported by experiments on rapidly decaying isotopes but is more difficult to verify for slowly decaying isotopes. The decay of 14C can be calibrated over a period of 12,550 years by comparing radiocarbon dates with dates obtained from dendrochronology. It is well known that this approach shows that radiocarbon dates of over 3,000 years are in error, which is generally attributed to past variation in atmospheric levels of 14C. We note that predicted atmospheric variation (assuming exponential decay) does not agree with results from modelling, and that theoretical quantum mechanics does not predict exact exponential decay. We give mathematical arguments that non-exponential decay should be expected for slowly decaying isotopes and explore the consequences of non-exponential decay. We propose an experimental test of this prediction of non-exponential decay for 14C. If confirmed, a foundation stone of current dating methods will have been removed, requiring a radical reappraisal both of radioisotope dating methods and of currently predicted dates obtained using these methods.

  20. The Discovery of Artificial Radioactivity

    NASA Astrophysics Data System (ADS)

    Guerra, Francesco; Leone, Matteo; Robotti, Nadia

    2012-03-01

    We reconstruct Frédéric Joliot and Irène Curie's discovery of artificial radioactivity in January 1934 based in part on documents preserved in the Joliot-Curie Archives in Paris, France. We argue that their discovery followed from the convergence of two parallel lines of research, on the neutron and on the positron, that were focused on a well-defined experimental problem, the nuclear transmutation of aluminum and other light elements. We suggest that a key role was played by a suggestion that Francis Perrin made at the seventh Solvay Conference at the end of October 1933, that the alpha-particle bombardment of aluminum produces an intermediate unstable isotope of phosphorus, which then decays by positron emission. We also suggest that a further idea that Perrin published in December 1933, and the pioneering theory of beta decay that Enrico Fermi also first published in December 1933, established a new theoretical framework that stimulated Joliot to resume the researches that he and Curie had interrupted after the Solvay Conference, now for the first time using a Geiger-Müller counter to detect the positrons emitted when he bombarded aluminum with polonium alpha particles.

  1. Computed tomography of radioactive objects and materials

    NASA Astrophysics Data System (ADS)

    Sawicka, B. D.; Murphy, R. V.; Tosello, G.; Reynolds, P. W.; Romaniszyn, T.

    1990-12-01

    Computed tomography (CT) has been performed on a number of radioactive objects and materials. Several unique technical problems are associated with CT of radioactive specimens. These include general safety considerations, techniques to reduce background-radiation effects on CT images and selection criteria for the CT source to permit object penetration and to reveal accurate values of material density. In the present paper, three groups of experiments will be described, for objects with low, medium and high levels of radioactivity. CT studies on radioactive specimens will be presented. They include the following: (1) examination of individual ceramic reactor-fuel (uranium dioxide) pellets, (2) examination of fuel samples from the Three Mile Island reactor, (3) examination of a CANDU (CANada Deuterium Uraniun: registered trademark) nuclear-fuel bundle which underwent a simulated loss-of-coolant accident resulting in high-temperature damage and (4) examination of a PWR nuclear-reactor fuel assembly.

  2. 46 CFR 148.300 - Radioactive materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... radioactive materials defined in 49 CFR 173.403 as Low Specific Activity Material, LSA-1, or Surface... thorium, uranium-235, uranium-238, thorium-232, thorium-228 and thorium-230 when contained in ores...

  3. 46 CFR 148.300 - Radioactive materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... radioactive materials defined in 49 CFR 173.403 as Low Specific Activity Material, LSA-1, or Surface... thorium, uranium-235, uranium-238, thorium-232, thorium-228 and thorium-230 when contained in ores...

  4. 46 CFR 148.300 - Radioactive materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... radioactive materials defined in 49 CFR 173.403 as Low Specific Activity Material, LSA-1, or Surface... thorium, uranium-235, uranium-238, thorium-232, thorium-228 and thorium-230 when contained in ores...

  5. 46 CFR 148.300 - Radioactive materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... radioactive materials defined in 49 CFR 173.403 as Low Specific Activity Material, LSA-1, or Surface... thorium, uranium-235, uranium-238, thorium-232, thorium-228 and thorium-230 when contained in ores...

  6. Overflow of Radioactive Water from K Basins

    SciTech Connect

    RITTMANN, P.D.

    1999-10-06

    This report documents the dose calculations for the postulated K Basin overflow accident using current methods to model the environmental doses for radioactive releases into the Columbia River and the air.

  7. Radioactive materials shipping cask anticontamination enclosure

    DOEpatents

    Belmonte, Mark S. (Irwin, PA); Davis, James H. (Pittsburgh, PA); Williams, David A. (Pittsburgh, PA)

    1982-01-01

    An anticontamination device for use in storing shipping casks for radioactive materials comprising (1) a seal plate assembly; (2) a double-layer plastic bag; and (3) a water management system or means for water management.

  8. RADIOACTIVITY STANDARDS DISTRIBUTION PROGRAM, 1978-1979

    EPA Science Inventory

    A program for the distribution of calibrated radioactive samples, as one function of EPA's quality assurance program for environmental radiation measurements, is described. Included is a discussion of the objectives of the distribution program and a description of the preparation...

  9. Computer Model Buildings Contaminated with Radioactive Material

    Energy Science and Technology Software Center (ESTSC)

    1998-05-19

    The RESRAD-BUILD computer code is a pathway analysis model designed to evaluate the potential radiological dose incurred by an individual who works or lives in a building contaminated with radioactive material.

  10. Radioactive Dating: A Method for Geochronology.

    ERIC Educational Resources Information Center

    Rowe, M. W.

    1985-01-01

    Gives historical background on the discovery of natural radiation and discusses various techniques for using knowledge of radiochemistry in geochronological studies. Indicates that of these radioactive techniques, Potassium-40/Argon-40 dating is used most often. (JN)

  11. Radioactivity in man: levels, effects and unknowns

    SciTech Connect

    Rundo, J.

    1980-01-01

    The report discusses the potential for significant human exposure to internal radiation. Sources of radiation considered include background radiation, fallout, reactor accidents, radioactive waste, and occupational exposure to various radioisotopes. (ACR)

  12. Principles for Sampling Airborne Radioactivity from Stacks

    SciTech Connect

    Glissmeyer, John A.

    2010-10-18

    This book chapter describes the special processes involved in sampling the airborne effluents from nuclear faciities. The title of the book is Radioactive Air Sampling Methods. The abstract for this chapter was cleared as PNNL-SA-45941.

  13. Radioactive waste disposal: An environmental perspective

    SciTech Connect

    Not Available

    1994-08-01

    There are five general categories of radioactive waste: (1) spent nuclear fuel from nuclear reactors and high-level waste from the reprocessing of spent nuclear fuel, (2) transuranic waste mainly from defense programs, (3) uranium mill tailings from the mining and milling of uranium ore, (4) low-level waste, and (5) naturally occurring and acclerator-produced radioactive materials. The booklet describes the different categories of waste, discusses disposal practices for each type, and describes the way they are regulated.

  14. Transport of Radioactive Material by Alpha Recoil

    SciTech Connect

    Icenhour, A.S.

    2005-05-19

    The movement of high-specific-activity radioactive particles (i.e., alpha recoil) has been observed and studied since the early 1900s. These studies have been motivated by concerns about containment of radioactivity and the protection of human health. Additionally, studies have investigated the potential advantage of alpha recoil to effect separations of various isotopes. This report provides a review of the observations and results of a number of the studies.

  15. Exoplanets' atmospheres: comparing and separating different sources of disequilibria

    NASA Astrophysics Data System (ADS)

    Simoncini, Eugenio; Brucato, John Robert

    The atmosphere of the only known (till nowadays) inhabited planet is characterized by a unique disequilibrium state in terms of chemical composition. Studying this state of disequilibrium is important for its potential role in the detection of life on other suitable planets [1][2][3]. However, different processes are able to produce chemical disequilibrium in planetary atmospheres, thus a tool to compute the extent of disequilibrium is needed. We developed a methodology to calculate the extent of atmospheric chemical disequilibrium [3][4]. A new computational framework called KROME has been applied to atmospheric models in order to give a correct computation of reaction? kinetics [5]. This methodology allows to compute, for models of different planets, the extent of disequilibrium due to several processes, such as fast vertical mixing, eddy diffusion, photochemistry, extremely diverse atmospheres due to tidal effect. Using Earth’s models, we also infer the potential extension of the effect of a biosphere on disequilibrium. Our results provide a comprehensive analysis of atmospheric disequilibrium for rocky planets, which can be also used for the detection of habitable conditions on farther planetary bodies. [1] Lovelock, J. E.: A physical basis for life detection experiments, Nature, 207, 568 (1965) [2] Kleidon, A., Physics of Life Reviews, 7, 424 (2010) [3] Simoncini E., Grassi T., Disequilibrium in planetary atmospheres: a first calculation for Earth using KROME, submitted to OLEB. [4] Kondepudi D., Prigogine I., Modern Thermodynamics, Wiley (1996) [5] Grassi, T., Bovino, S., Schleicher, D. R. G., Prieto, J., Seifried, D., Simoncini, E., Gianturco, F. A., in press on Mon. Not. R. Astron. Soc. MN-13-2848-MJ.R1

  16. s.haszeldine@ed.ac.uk Radioactive waste Cumbria 6, 7 Sept 2012 1 Geological disposal of radioactive

    E-print Network

    s.haszeldine@ed.ac.uk Radioactive waste Cumbria 6, 7 Sept 2012 1 Geological disposal of radioactive_and_Copeland.html #12;Nuclear power s.haszeldine@ed.ac.uk Radioactive waste Cumbria 6, 7 Sept 2012 2 First civil nuclear #12;Keeping hot fuel on the surface for 50-150 years s.haszeldine@ed.ac.uk Radioactive waste Cumbria 6

  17. RADIOACTIVE WASTE DISPOSAL PROCEDURES 1. Radioactive waste is accepted for disposal by Radiation Safety on Monday, Wednesday and

    E-print Network

    Hammack, Richard

    RADIOACTIVE WASTE DISPOSAL PROCEDURES 1. Radioactive waste is accepted for disposal by Radiation are required and may be scheduled by calling 8289131. 2. Segregate and package radioactive waste according to type as described in the MCV/VCU Radiation Safety Guide. 3. Radioactive waste in red bags

  18. Public involvement in radioactive waste management decisions

    SciTech Connect

    1994-04-01

    Current repository siting efforts focus on Yucca Mountain, Nevada, where DOE`s Office of Civilian Radioactive Waste Management (OCRWM) is conducting exploratory studies to determine if the site is suitable. The state of Nevada has resisted these efforts: it has denied permits, brought suit against DOE, and publicly denounced the federal government`s decision to study Yucca Mountain. The state`s opposition reflects public opinion in Nevada, and has considerably slowed DOE`s progress in studying the site. The Yucca Mountain controversy demonstrates the importance of understanding public attitudes and their potential influence as DOE develops a program to manage radioactive waste. The strength and nature of Nevada`s opposition -- its ability to thwart if not outright derail DOE`s activities -- indicate a need to develop alternative methods for making decisions that affect the public. This report analyzes public participation as a key component of this openness, one that provides a means of garnering acceptance of, or reducing public opposition to, DOE`s radioactive waste management activities, including facility siting and transportation. The first section, Public Perceptions: Attitudes, Trust, and Theory, reviews the risk-perception literature to identify how the public perceives the risks associated with radioactivity. DOE and the Public discusses DOE`s low level of credibility among the general public as the product, in part, of the department`s past actions. This section looks at the three components of the radioactive waste management program -- disposal, storage, and transportation -- and the different ways DOE has approached the problem of public confidence in each case. Midwestern Radioactive Waste Management Histories focuses on selected Midwestern facility-siting and transportation activities involving radioactive materials.

  19. CHAPTER 5-RADIOACTIVE WASTE MANAGEMENT

    SciTech Connect

    Marra, J.

    2010-05-05

    The ore pitchblende was discovered in the 1750's near Joachimstal in what is now the Czech Republic. Used as a colorant in glazes, uranium was identified in 1789 as the active ingredient by chemist Martin Klaproth. In 1896, French physicist Henri Becquerel studied uranium minerals as part of his investigations into the phenomenon of fluorescence. He discovered a strange energy emanating from the material which he dubbed 'rayons uranique.' Unable to explain the origins of this energy, he set the problem aside. About two years later, a young Polish graduate student was looking for a project for her dissertation. Marie Sklodowska Curie, working with her husband Pierre, picked up on Becquerel's work and, in the course of seeking out more information on uranium, discovered two new elements (polonium and radium) which exhibited the same phenomenon, but were even more powerful. The Curies recognized the energy, which they now called 'radioactivity,' as something very new, requiring a new interpretation, new science. This discovery led to what some view as the 'golden age of nuclear science' (1895-1945) when countries throughout Europe devoted large resources to understand the properties and potential of this material. By World War II, the potential to harness this energy for a destructive device had been recognized and by 1939, Otto Hahn and Fritz Strassman showed that fission not only released a lot of energy but that it also released additional neutrons which could cause fission in other uranium nuclei leading to a self-sustaining chain reaction and an enormous release of energy. This suggestion was soon confirmed experimentally by other scientists and the race to develop an atomic bomb was on. The rest of the development history which lead to the bombing of Hiroshima and Nagasaki in 1945 is well chronicled. After World War II, development of more powerful weapons systems by the United States and the Soviet Union continued to advance nuclear science. It was this defense application that formed the basis for the commercial nuclear power industry.

  20. Laser decontamination of the radioactive lightning rods

    NASA Astrophysics Data System (ADS)

    Potiens, A. J.; Dellamano, J. C.; Vicente, R.; Raele, M. P.; Wetter, N. U.; Landulfo, E.

    2014-02-01

    Between 1970 and 1980 Brazil experienced a significant market for radioactive lightning rods (RLR). The device consists of an air terminal with one or more sources of americium-241 attached to it. The sources were used to ionize the air around them and to increase the attraction of atmospheric discharges. Because of their ineffectiveness, the nuclear regulatory authority in Brazil suspended the license for manufacturing, commerce and installation of RLR in 1989, and determined that the replaced RLR were to be collected to a centralized radioactive waste management facility for treatment. The first step for RLR treatment is to remove the radioactive sources. Though they can be easily removed, some contaminations are found all over the remaining metal scrap that must decontaminated for release, otherwise it must be treated as radioactive waste. Decontamination using various chemicals has proven to be inefficient and generates large amounts of secondary wastes. This work shows the preliminary results of the decontamination of 241Am-contaminated metal scrap generated in the treatment of radioactive lightning rods applying laser ablation. A Nd:YAG nanoseconds laser was used with 300 mJ energy leaving only a small amount of secondary waste to be treated.

  1. Radioactive waste management in a hospital.

    PubMed

    Khan, Shoukat; Syed, At; Ahmad, Reyaz; Rather, Tanveer A; Ajaz, M; Jan, Fa

    2010-01-01

    Most of the tertiary care hospitals use radioisotopes for diagnostic and therapeutic applications. Safe disposal of the radioactive waste is a vital component of the overall management of the hospital waste. An important objective in radioactive waste management is to ensure that the radiation exposure to an individual (Public, Radiation worker, Patient) and the environment does not exceed the prescribed safe limits. Disposal of Radioactive waste in public domain is undertaken in accordance with the Atomic Energy (Safe disposal of radioactive waste) rules of 1987 promulgated by the Indian Central Government Atomic Energy Act 1962. Any prospective plan of a hospital that intends using radioisotopes for diagnostic and therapeutic procedures needs to have sufficient infrastructural and manpower resources to keep its ambient radiation levels within specified safe limits. Regular monitoring of hospital area and radiation workers is mandatory to assess the quality of radiation safety. Records should be maintained to identify the quality and quantity of radioactive waste generated and the mode of its disposal. Radiation Safety officer plays a key role in the waste disposal operations. PMID:21475524

  2. Landscape of two-proton radioactivity.

    PubMed

    Olsen, E; Pfützner, M; Birge, N; Brown, M; Nazarewicz, W; Perhac, A

    2013-05-31

    Ground-state two-proton (2p) radioactivity is a decay mode found in isotopes of elements with even atomic numbers located beyond the two-proton drip line. So far, this exotic process has been experimentally observed in a few light- and medium-mass nuclides with Z?30. In this study, using state-of-the-art nuclear density functional theory, we globally analyze 2p radioactivity and for the first time identify 2p-decay candidates in elements heavier than strontium. We predict a few cases where the competition between 2p emission and ? decay may be observed. In nuclei above lead, the ?-decay mode is found to be dominating and no measurable candidates for the 2p radioactivity are expected. PMID:23767715

  3. Conditioning of Degradated Packages with Radioactive Waste

    SciTech Connect

    Dogaru, G. C.

    2002-02-25

    The development of the nuclear techniques in Romania and the commissioning of the WWR-S research reactor belonging to the Institute of Physics and Nuclear Engineering-(NIPNE) demand to deal with the storage and disposal of radioactive waste. The institute decided to store the radioactive waste inside a building that belonged to the Defense of Capital City System (the Army) called ''Fort'' which is located on the Magurele site. There are still about 800 packages containing cement conditioned radioactive in the storage facility of NIPNE which need to be repackaged, because they are in an advanced state of degradation. The new package obtained the regulatory design approval. It consists in an internal basket in which the degraded package are placed, a cement containment system, and an external cask in which the basket are placed and conditioned with the cement.

  4. Low radioactivity spectral gamma calibration facility

    SciTech Connect

    Mathews, M.A.; Bowman, H.R.; Huang, L., H.; Lavelle, M.J.; Smith, A.R.; Hearst, J.R.; Wollenberg, H.A.; Flexser, S.

    1986-01-01

    A low radioactivity calibration facility has been constructed at the Nevada Test Site (NTS). This facility has four calibration models of natural stone that are 3 ft in diameter and 6 ft long, with a 12 in. cored borehole in the center of each model and a lead-shielded run pipe below each model. These models have been analyzed by laboratory natural gamma ray spectroscopy (NGRS) and neutron activation analysis (NAA) for their K, U, and Th content. Also, 42 other elements were analyzed in the NAA. The /sup 222/Rn emanation data were collected. Calibrating the spectral gamma tool in this low radioactivity calibration facility allows the spectral gamma log to accurately aid in the recognition and mapping of subsurface stratigraphic units and alteration features associated with unusual concentrations of these radioactive elements, such as clay-rich zones.

  5. Radioactive decays at limits of nuclear stability

    E-print Network

    M. Pfützner; L. V. Grigorenko; M. Karny; K. Riisager

    2011-11-02

    The last decades brought an impressive progress in synthesizing and studying properties of nuclides located very far from the beta stability line. Among the most fundamental properties of such exotic nuclides, usually established first, is the half-life, possible radioactive decay modes, and their relative probabilities. When approaching limits of nuclear stability, new decay modes set in. First, beta decays become accompanied by emission of nucleons from highly excited states of daughter nuclei. Second, when the nucleon separation energy becomes negative, nucleons start to be emitted from the ground state. Here, we present a review of the decay modes occurring close to the limits of stability. The experimental methods used to produce, identify and detect new species and their radiation are discussed. The current theoretical understanding of these decay processes is overviewed. The theoretical description of the most recently discovered and most complex radioactive process - the two-proton radioactivity - is discussed in more detail.

  6. Radioactivity and electron acceleration in supernova remnants

    SciTech Connect

    Zirakashvili, V. N.; Aharonian, F. A.

    2011-10-15

    We argue that the decays of radioactive nuclei related to {sup 44}Ti and {sup 56}Ni ejected during supernova explosions can provide a vast pool of mildly relativistic positrons and electrons which are further accelerated to ultrarelativistic energies by reverse and forward shocks. This interesting link between two independent processes - the radioactivity and the particle acceleration - can be a clue for solution of the well known theoretical problem of electron injection in supernova remnants. In the case of the brightest radio source Cas A, we demonstrate that the radioactivity can supply adequate number of energetic electrons and positrons for interpretation of observational data provided that they are stochastically preaccelerated in the upstream regions of the forward and reverse shocks.

  7. Radioactive source security: the cultural challenges.

    PubMed

    Englefield, Chris

    2015-04-01

    Radioactive source security is an essential part of radiation protection. Sources can be abandoned, lost or stolen. If they are stolen, they could be used to cause deliberate harm and the risks are varied and significant. There is a need for a global security protection system and enhanced capability to achieve this. The establishment of radioactive source security requires 'cultural exchanges'. These exchanges include collaboration between: radiation protection specialists and security specialists; the nuclear industry and users of radioactive sources; training providers and regulators/users. This collaboration will facilitate knowledge and experience exchange for the various stakeholder groups, beyond those already provided. This will promote best practice in both physical and information security and heighten security awareness generally. Only if all groups involved are prepared to open their minds to listen to and learn from, each other will a suitable global level of control be achieved. PMID:25377752

  8. Wide range radioactive gas concentration detector

    DOEpatents

    Anderson, David F. (Los Alamos, NM)

    1984-01-01

    A wide range radioactive gas concentration detector and monitor which is capable of measuring radioactive gas concentrations over a range of eight orders of magnitude. The device of the present invention is designed to have an ionization chamber which is sufficiently small to give a fast response time for measuring radioactive gases but sufficiently large to provide accurate readings at low concentration levels. Closely spaced parallel plate grids provide a uniform electric field in the active region to improve the accuracy of measurements and reduce ion migration time so as to virtually eliminate errors due to ion recombination. The parallel plate grids are fabricated with a minimal surface area to reduce the effects of contamination resulting from absorption of contaminating materials on the surface of the grids. Additionally, the ionization chamber wall is spaced a sufficient distance from the active region of the ionization chamber to minimize contamination effects.

  9. Radioactive tank waste remediation focus area

    SciTech Connect

    1996-08-01

    EM`s Office of Science and Technology has established the Tank Focus Area (TFA) to manage and carry out an integrated national program of technology development for tank waste remediation. The TFA is responsible for the development, testing, evaluation, and deployment of remediation technologies within a system architecture to characterize, retrieve, treat, concentrate, and dispose of radioactive waste stored in the underground stabilize and close the tanks. The goal is to provide safe and cost-effective solutions that are acceptable to both the public and regulators. Within the DOE complex, 335 underground storage tanks have been used to process and store radioactive and chemical mixed waste generated from weapon materials production and manufacturing. Collectively, thes tanks hold over 90 million gallons of high-level and low-level radioactive liquid waste in sludge, saltcake, and as supernate and vapor. Very little has been treated and/or disposed or in final form.

  10. Influence of Relic Neutrinos on Beta Radioactivity

    E-print Network

    A. G. Parkhomov

    2010-10-08

    Results of calculations of distribution and motion of dark matter are presented. Considering neutrino as one of the components of dark matter and taking into account peculiar features of the interactions of slow neutrinos with matter, allow to make the conclusion that they may have tangible manifestations not only in the depths of the Universe but also on the Earth. Experimental results confirming predicted effects are described, including periodic variations of the beta radioactivity as well as count rate bursts for a beta radioactive source placed at the focal point of a parabolic mirror. Based on the data of astronomical observations, estimates of the mass of the particles influencing on beta radioactivity (about 20 eV) and their flux density (about 10^13 particles/cm^2 s) have been made. The discrepancy between our mass estimate and the 2 eV limit for the neutrino mass, established in the tritium experiments, is discussed.

  11. Cubic potential models for cluster radioactivity

    NASA Astrophysics Data System (ADS)

    Shanmugam, G.

    1999-09-01

    Cluster radioactivity is a process by which nuclei equal and heavier than the a-particleis emitted spontaneously. The clusters usually emitted in this process are the a-particle, carbon, oxygen, neon, magnesium, silicon etc. When the mass of the cluster becomes comparable with the mass of the daughter, symmetric fission takes place. Thus the cluster radioactivity is an intermediate process between the well known a-decay and the spontaneous fission. In earlier years such cluster radioactivity was found mostly in actinide nuclei like radium, uranium etc. Very recently it has been predicted that such decays are possible in a new region around 114Ba. There has been an exciting experimental detection of the emission of 12C from 114Ba leading to 102Sn, which is attracting a lot of attention recently. To study the phenomenon of cluster radioactivity there are various theoretical models in vogue. The existing models generally fall under two categories: the unified fission model (UFM) and the preformed cluster model (PCM). The physics of the UFM and the PCM are completely different. The UFM considers cluster radioactivity simply as a barrier penetration phenomenon in between the fission and the a-decay without worrying about the cluster being or not being preformed in the parent nucleus. In the PCM clusters are assumed to be preborn in a parent nucleus before they could penetrate the potential barrier with a given Q-value. The basic assumption of the UFM is that heavy clusters as well as the a-particle have equal probability of being preformed. In PCM, clusters of different sizes have different probabilities of their being preformed in the parent nucleus. We have developed three fission models during the last decade using the cubic potential for the pre-scission region. The use of these models in the study of cluster radioactivity in both the actinide and barium regions will be discussed in this talk in comparison with the other existing theories.

  12. Pump station for radioactive waste water

    DOEpatents

    Whitton, John P.; Klos, Dean M.; Carrara, Danny T.; Minno, John J.

    2003-11-18

    A pump station for transferring radioactive particle containing waste water, includes: (a.) an enclosed sump having a vertically elongated right frusto conical wall surface and a bottom surface and (b.) a submersible volute centrifugal pump having a horizontally rotating impeller and a volute exterior surface. The sump interior surface, the bottom surface and the volute exterior surface are made of stainless steel having a 30 Ra or finer surface finish. A 15 Ra finish has been found to be most cost effective. The pump station is used for transferring waste water, without accumulation of radioactive fines.

  13. TRAC laboratory monitoring of Chernobyl radioactive debris

    SciTech Connect

    Sigg, R.A.

    1986-06-09

    A severe accident occurred at the Chernobyl nuclear power plant number 4 in the Soviet Union on April 25, 1986. An explosion released large amounts of radioactive debris, primarily fission products, to the atmosphere. As winds carried debris from the Soviet Union, scientists in Europe and the United States reported detecting fission product activities in air samples. Monitoring by the Tracking Radioactive Atmospheric Contaminants (TRAC) mobile laboratory showed concentrations in the Southeastern United States were well below those considered hazardous. This document provides details of this monitoring effort.

  14. Nondestructive measurement of environmental radioactive strontium

    NASA Astrophysics Data System (ADS)

    Saiba, Shuntaro; Okamiya, Tomohiro; Tanaka, Saki; Tanuma, Ryosuke; Totsuka, Yumi; Murata, Jiro

    2014-03-01

    The Fukushima Daiichi nuclear power plant accident was triggered by the 2011 Great East Japan Earthquake. The main radioactivity concerns after the accident are I-131 (half-life: 8.0 days), Cs-134 (2.1 years), Cs-137 (30 years), Sr-89 (51 days), and Sr-90 (29 years). We are aiming to establish a new nondestructive measurement and detection technique that will enable us to realize a quantitative evaluation of strontium radioactivity without chemical separation processing. This technique is needed to detect radiation contained in foods, environmental water, and soil, to prevent us from undesired internal exposure to radiation.

  15. Annual Radioactive Waste Tank Inspection Program - 2000

    SciTech Connect

    West, W.R.

    2001-04-17

    Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2000 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report.

  16. Annual radioactive waste tank inspection program - 1999

    SciTech Connect

    Moore, C.J.

    2000-04-14

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1999 to evaluate these vessels and auxiliary appurtenances along with evaluations based on data accrued by inspections performed since the tanks were constructed are the subject of this report.

  17. Annual radioactive waste tank inspection program - 1996

    SciTech Connect

    McNatt, F.G.

    1997-04-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1996 to evaluate these vessels, and evaluations based on data accrued by inspections performed since the tanks were constructed, are the subject of this report.

  18. Concretes for radio-active wastes storages

    SciTech Connect

    Akhmadiarov, D.M.; Gorobets, I.I.

    1993-12-31

    In the future, nuclear engineering should include storing radioactive wastes, nuclear reactors, and other engineering components underground in rocks or underground abandoned mines. This paper discusses the construction of underground facilities with regard to the use of concretes with binding agents. The properties of the concretes are described.

  19. Annual Radioactive Waste Tank Inspection Program - 1998

    SciTech Connect

    McNatt, F.G.

    1999-10-27

    Aqueous radioactive wastes from Savannah River Site separations processes are contained in large underground carbon steel tanks. Inspections made during 1998 to evaluate these vessels and auxiliary appurtenances, along with evaluations based on data accrued by inspections performed since the tanks were constructed, are the subject of this report.

  20. Canister arrangement for storing radioactive waste

    DOEpatents

    Lorenzo, Donald K. (Knoxville, TN); Van Cleve, Jr., John E. (Kingston, TN)

    1982-01-01

    The subject invention relates to a canister arrangement for jointly storing high level radioactive chemical waste and metallic waste resulting from the reprocessing of nuclear reactor fuel elements. A cylindrical steel canister is provided with an elongated centrally disposed billet of the metallic waste and the chemical waste in vitreous form is disposed in the annulus surrounding the billet.

  1. Annual radioactive waste tank inspection program - 1992

    SciTech Connect

    McNatt, F.G.

    1992-12-31

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1992 to evaluate these vessels and evaluations based on data accrued by inspections made since the tanks were constructed are the subject of this report.

  2. Remediation of groundwater contaminated with radioactive compounds

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Both naturally radioactive isotopes and isotopes from man-made sources may appear in groundwater. Depending on the physical and chemical characteristics of the contaminant, different types of treatment methods must be applied to reduce the concentration. The following chapter discusses treatment opt...

  3. ANNUAL RADIOACTIVE WASTE TANK INSPECTION PROGRAM 2008

    SciTech Connect

    West, B.; Waltz, R.

    2009-06-11

    Aqueous radioactive wastes from Savannah River Site (SRS) separations and vitrification processes are contained in large underground carbon steel tanks. Inspections made during 2008 to evaluate these vessels and other waste handling facilities along with evaluations based on data from previous inspections are the subject of this report.

  4. Annual radioactive waste tank inspection program: 1995

    SciTech Connect

    McNatt, F.G. Sr.

    1996-04-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1995 to evaluate these vessels and evaluations based on data accrued by inspections performed since the tanks were constructed are the subject of this report

  5. Annual Radioactive Waste Tank Inspection Program - 1997

    SciTech Connect

    McNatt, F.G.

    1998-05-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1997 to evaluate these vessels, and evaluations based on data accrued by inspections performed since the tanks were constructed are the subject of this report.

  6. Annual Radioactive Waste Tank Inspection Program 1994

    SciTech Connect

    McNatt, F.G. Sr.

    1995-04-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1994 to evaluate these vessels and evaluations based on data accrued by inspections made since the tanks were constructed are the subject of this report.

  7. Method for decontamination of radioactive metal surfaces

    DOEpatents

    Bray, L.A.

    1996-08-13

    Disclosed is a method for removing radioactive contaminants from metal surfaces by applying steam containing an inorganic acid and cerium IV. Cerium IV is applied to contaminated metal surfaces by introducing cerium IV in solution into a steam spray directed at contaminated metal surfaces. Cerium IV solution is converted to an essentially atomized or vapor phase by the steam.

  8. Canister arrangement for storing radioactive waste

    DOEpatents

    Lorenzo, D.K.; Van Cleve, J.E. Jr.

    1980-04-23

    The subject invention relates to a canister arrangement for jointly storing high level radioactive chemical waste and metallic waste resulting from the reprocessing of nuclear reactor fuel elements. A cylindrical steel canister is provided with an elongated centrally disposed billet of the metallic waste and the chemical waste in vitreous form is disposed in the annulus surrounding the billet.

  9. Simplifying the Mathematical Treatment of Radioactive Decay

    ERIC Educational Resources Information Center

    Auty, Geoff

    2011-01-01

    Derivation of the law of radioactive decay is considered without prior knowledge of calculus or the exponential series. Calculus notation and exponential functions are used because ultimately they cannot be avoided, but they are introduced in a simple way and explained as needed. (Contains 10 figures, 1 box, and 1 table.)

  10. RADIOACTIVE MATERIALS IN BIOSOLIDS: DOSE MODELING

    EPA Science Inventory

    The Interagency Steering Committee on Radiation Standards (ISCORS) has recently completed a study of the occurrence within the United States of radioactive materials in sewage sludge and sewage incineration ash. One component of that effort was an examination of the possible tra...

  11. Obtaining and Investigating Unconventional Sources of Radioactivity

    ERIC Educational Resources Information Center

    Lapp, David R.

    2010-01-01

    This paper provides examples of naturally radioactive items that are likely to be found in most communities. Additionally, there is information provided on how to acquire many of these items inexpensively. I have found that the presence of these materials in the classroom is not only useful for teaching about nuclear radiation and debunking the…

  12. Recycling and Reuse of Radioactive Materials

    ERIC Educational Resources Information Center

    O'Dou, Thomas Joseph

    2012-01-01

    The Radiochemistry Program at the University of Nevada, Las Vegas (UNLV) has a Radiation Protection Program that was designed to provide students with the ability to safely work with radioactive materials in quantities that are not available in other academic environments. Requirements for continuous training and supervision make this unique…

  13. Method for decontamination of radioactive metal surfaces

    DOEpatents

    Bray, Lane A. (Richland, WA)

    1996-01-01

    Disclosed is a method for removing radioactive contaminants from metal surfaces by applying steam containing an inorganic acid and cerium IV. Cerium IV is applied to contaminated metal surfaces by introducing cerium IV in solution into a steam spray directed at contaminated metal surfaces. Cerium IV solution is converted to an essentially atomized or vapor phase by the steam.

  14. 49 CFR 175.705 - Radioactive contamination.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... carrier shall take care to avoid possible inhalation, ingestion, or contact by any person with Class 7... has been released must be taken out of service and may not be returned to service or routinely... for radioactive contamination, and an aircraft must be taken out of service if contamination...

  15. A Sensitive Cloud Chamber without Radioactive Sources

    ERIC Educational Resources Information Center

    Zeze, Syoji; Itoh, Akio; Oyama, Ayu; Takahashi, Haruka

    2012-01-01

    We present a sensitive diffusion cloud chamber which does not require any radioactive sources. A major difference from commonly used chambers is the use of a heat sink as its bottom plate. The result of a performance test of the chamber is given. (Contains 8 figures.)

  16. Ion beam analysis of radioactive samples

    NASA Astrophysics Data System (ADS)

    Raepsaet, C.; Khodja, H.; Bossis, P.; Pipon, Y.; Roudil, D.

    2009-06-01

    The nuclear microprobe facility of the Pierre Süe Laboratory is fitted with two microbeam lines. One is dedicated to non-active samples. The other one, located in a controlled shielded area, offers the unique feature of being devoted to radioactive samples. Operational since 1998, it is strongly linked to nuclear research programs and has been dimensioned to accept radioactive but non-contaminant radioactive samples, including small quantities of UOX or MOX irradiated fuel. The samples, transported in a shipping cask, are unloaded and handled in hot cells with slaved arms. The analysis chamber, situated in a concrete cell, is equipped with charged particle detectors and a Si(Li) X-ray detector, shielded in order to reduce the radioactive noise produced by the sample, allowing ERDA, RBS, NRA and PIXE. After a description of the facility, including the sample handling in the hot cells and the analysis chamber, we will give an overview of the various experimental programs which have been performed, with an emphasis on the determination of the hydrogen distribution and local content in nuclear fuel cladding tubes.

  17. 49 CFR 172.556 - RADIOACTIVE placard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 49 Transportation 2 2010-10-01 2010-10-01 false RADIOACTIVE placard. 172.556 Section 172.556 Transportation Other Regulations Relating to Transportation PIPELINE AND HAZARDOUS MATERIALS SAFETY ADMINISTRATION, DEPARTMENT OF TRANSPORTATION HAZARDOUS MATERIALS REGULATIONS HAZARDOUS MATERIALS TABLE, SPECIAL PROVISIONS, HAZARDOUS...

  18. High-level radioactive wastes. Supplement 1

    SciTech Connect

    McLaren, L.H.

    1984-09-01

    This bibliography contains information on high-level radioactive wastes included in the Department of Energy's Energy Data Base from August 1982 through December 1983. These citations are to research reports, journal articles, books, patents, theses, and conference papers from worldwide sources. Five indexes, each preceded by a brief description, are provided: Corporate Author, Personal Author, Subject, Contract Number, and Report Number. 1452 citations.

  19. 10 CFR 76.81 - Authorized use of radioactive material.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...radioactive material. 76.81 Section 76.81 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.81 Authorized use of radioactive material. Unless otherwise authorized by law, the...

  20. 10 CFR 76.81 - Authorized use of radioactive material.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...radioactive material. 76.81 Section 76.81 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.81 Authorized use of radioactive material. Unless otherwise authorized by law, the...

  1. 10 CFR 76.81 - Authorized use of radioactive material.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...radioactive material. 76.81 Section 76.81 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.81 Authorized use of radioactive material. Unless otherwise authorized by law, the...

  2. 10 CFR 76.81 - Authorized use of radioactive material.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...radioactive material. 76.81 Section 76.81 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.81 Authorized use of radioactive material. Unless otherwise authorized by law, the...

  3. 77 FR 26991 - Low-Level Radioactive Waste Management Issues

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-05-08

    ...3150-AI92 Low-Level Radioactive Waste Management Issues AGENCY: Nuclear Regulatory...and Low-Level Radioactive Waste Management'' (76 FR 50500; August...Assessment Directorate, Division of Waste Management and Environmental...

  4. 77 FR 10401 - Low-Level Radioactive Waste Management Issues

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-02-22

    ...NRC-2011-0012] Low-Level Radioactive Waste Management Issues AGENCY: Nuclear Regulatory...assessment as part of its radioactive waste management decision-making. The DOE...Assessment Directorate, Division of Waste Management and Environmental...

  5. 10 CFR 76.81 - Authorized use of radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...radioactive material. 76.81 Section 76.81 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.81 Authorized use of radioactive material. Unless otherwise authorized by law, the...

  6. 49 CFR 172.310 - Class 7 (radioactive) materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...SPECIAL PROVISIONS, HAZARDOUS MATERIALS COMMUNICATIONS, EMERGENCY... Class 7 (radioactive) materials. In addition to any other...containing Class 7 (radioactive) materials must be marked as follows...the package. (b) Each industrial, Type A, Type B(U), or Type...

  7. VEHS Radiation Safety Radioactive Material Sink Disposal Log

    E-print Network

    Wikswo, John

    be disposed in a sink posted with a "Radioactive Hot Sink" label by VEHS radiation safety. Date of DisposalVEHS Radiation Safety Radioactive Material Sink Disposal Log Keep Posted ­ VEHS Radiation Safety: Date Entered: ____________ Initials: _____ Principal Investigator: _____________________ Date Posted

  8. Radioactive Material Inspection/Survey Guidelines SIGNAGE AND POSTINGS

    E-print Network

    Radioactive Material Inspection/Survey Guidelines SIGNAGE AND POSTINGS Answer "yes", "no", or "n of radioactive materials. This can be done using an LSC or gamma counter, or a Geiger counter if applicable (can

  9. Development of sampling methodic of radioactive materials and measurements in performing radioactive inspection of APS

    SciTech Connect

    Matusevich, E.S.; Cherkashin, V.A.

    1993-12-31

    This report describes sampling methods and methods of determination of radioactive contamination which are needed in reactor decommissioning. The decommissioning of the Armenian Power Plant is and inspection techniques is discussed.

  10. Radioactive Waste Management in Central Asia - 12034

    SciTech Connect

    Zhunussova, Tamara; Sneve, Malgorzata; Liland, Astrid

    2012-07-01

    After the collapse of the Soviet Union the newly independent states in Central Asia (CA) whose regulatory bodies were set up recently are facing problems with the proper management of radioactive waste and so called 'nuclear legacy' inherited from the past activities. During the former Soviet Union (SU) period, various aspects of nuclear energy use took place in CA republics of Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan. Activities range from peaceful use of energy to nuclear testing for example at the former Semipalatinsk Nuclear Test Site (SNTS) in Kazakhstan, and uranium mining and milling industries in all four countries. Large amounts of radioactive waste (RW) have been accumulated in Central Asia and are waiting for its safe disposal. In 2008 the Norwegian Radiation Protection Authority (NRPA), with the support of the Norwegian Ministry of Foreign Affairs, has developed bilateral projects that aim to assist the regulatory bodies in Kazakhstan, Kyrgyzstan Tajikistan, and Uzbekistan (from 2010) to identify and draft relevant regulatory requirements to ensure the protection of the personnel, population and environment during the planning and execution of remedial actions for past practices and radioactive waste management in the CA countries. The participating regulatory authorities included: Kazakhstan Atomic Energy Agency, Kyrgyzstan State Agency on Environmental Protection and Forestry, Nuclear Safety Agency of Tajikistan, and State Inspectorate on Safety in Industry and Mining of Uzbekistan. The scope of the projects is to ensure that activities related to radioactive waste management in both planned and existing exposure situations in CA will be carried out in accordance with the international guidance and recommendations, taking into account the relevant regulatory practice from other countries in this area. In order to understand the problems in the field of radioactive waste management we have analysed the existing regulations through the so called 'Threat assessment' in each CA country which revealed additional problems in the existing regulatory documents beyond those described at the start of our ongoing bilateral projects in Kazakhstan, Kirgizistan Tajikistan and Uzbekistan. (authors)

  11. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...2012-07-01 2011-07-01 true High-level radioactive waste. 227.30 Section 227.30 Protection... Definitions § 227.30 High-level radioactive waste. High-level radioactive waste means the aqueous waste resulting...

  12. 48 CFR 245.7310-6 - Radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 48 Federal Acquisition Regulations System 3 2010-10-01 2010-10-01 false Radioactive material. 245... Radioactive material. The following shall be used whenever the property offered for sale is capable of emitting ionized radiation: Radioactive Material Purchasers are warned that the property may be capable...

  13. Review of physics, instrumentation and dosimetry of radioactive isotopes

    NASA Technical Reports Server (NTRS)

    Sinclair, W. K.

    1967-01-01

    General radioactive isotope information, stressing radioactivity, methods of measurement, and dosimetry of radioactive nuclides have been reviewed to serve as a reference for the medical profession. Instability of radionuclides, principal types of emission, and measurement of ionizing radiation are among the topics discussed.

  14. Generational Garbage Collection and the Radioactive Decay Model

    E-print Network

    Clinger, William D.

    Generational Garbage Collection and the Radioactive Decay Model William D Clinger and Lars T Hansen no information about its future life expectancy. This radioactive decay model implies there can be no rational no heuristic predictor can do better or worse than chance. The radioactive decay model is a model of object

  15. 46 CFR 109.559 - Explosives and radioactive materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ... 46 Shipping 4 2014-10-01 2014-10-01 false Explosives and radioactive materials. 109.559 Section... UNITS OPERATIONS Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized by the master or person in charge, no person may use explosives or radioactive materials and equipment...

  16. 46 CFR 109.559 - Explosives and radioactive materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ... 46 Shipping 4 2012-10-01 2012-10-01 false Explosives and radioactive materials. 109.559 Section... UNITS OPERATIONS Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized by the master or person in charge, no person may use explosives or radioactive materials and equipment...

  17. 46 CFR 109.559 - Explosives and radioactive materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 46 Shipping 4 2010-10-01 2010-10-01 false Explosives and radioactive materials. 109.559 Section... UNITS OPERATIONS Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized by the master or person in charge, no person may use explosives or radioactive materials and equipment...

  18. 46 CFR 109.559 - Explosives and radioactive materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 46 Shipping 4 2011-10-01 2011-10-01 false Explosives and radioactive materials. 109.559 Section... UNITS OPERATIONS Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized by the master or person in charge, no person may use explosives or radioactive materials and equipment...

  19. 46 CFR 109.559 - Explosives and radioactive materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ... 46 Shipping 4 2013-10-01 2013-10-01 false Explosives and radioactive materials. 109.559 Section... UNITS OPERATIONS Miscellaneous § 109.559 Explosives and radioactive materials. Except as authorized by the master or person in charge, no person may use explosives or radioactive materials and equipment...

  20. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 40 Protection of Environment 24 2010-07-01 2010-07-01 false High-level radioactive waste. 227.30...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated waste...

  1. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... 40 Protection of Environment 26 2012-07-01 2011-07-01 true High-level radioactive waste. 227.30...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated waste...

  2. 40 CFR 227.30 - High-level radioactive waste.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... 40 Protection of Environment 25 2014-07-01 2014-07-01 false High-level radioactive waste. 227.30...-level radioactive waste. High-level radioactive waste means the aqueous waste resulting from the operation of the first cycle solvent extraction system, or equivalent, and the concentrated waste...

  3. 10 CFR 76.83 - Transfer of radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Transfer of radioactive material. 76.83 Section 76.83 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.83 Transfer of radioactive material. (a) The Corporation may not transfer radioactive material except...

  4. UNIVERSITY OF CALIFORNIA, SAN DIEGO AUTHORIZATION TO PURCHASE RADIOACTIVE MATERIALS

    E-print Network

    California at San Diego, University of

    Radioactive Materials Page 2 of 2 SECTION 4 - SIGNATURES Department Buyer Date Department Head or PrincipalUNIVERSITY OF CALIFORNIA, SAN DIEGO AUTHORIZATION TO PURCHASE RADIOACTIVE MATERIALS (06/06) Page 1 of 2 For information on the online process for ordering Radioactive materials, please see a the Blink

  5. Survey of National Programs for Managing High-Level Radioactive

    E-print Network

    Survey of National Programs for Managing High-Level Radioactive Waste and Spent Nuclear Fuel-Level Radioactive Waste and Spent Nuclear Fuel A Report to Congress and the Secretary of Energy October 2009 #12 Safety (Germany) Peter De Preter: National Agency for Radioactive Waste and Enriched Fissile Materials

  6. Working with Radioactive Materials in Clinical Areas -Documentation

    E-print Network

    Jia, Songtao

    Working with Radioactive Materials in Clinical Areas - Documentation Procedure: 7.54 Created: 2008 Version: 1.1 Revised: 11/5/2013 10/22/2014 Working with Radioactive Materials in Clinical Areas of the City of New York, Article 175, Radiation Control1 and New York City Department of Health Radioactive

  7. Light radioactive nuclei capture reactions with phenomenological potential models.

    E-print Network

    Bertulani, Carlos A. - Department of Physics and Astronomy, Texas A&M University

    Light radioactive nuclei capture reactions with phenomenological potential models. V. Guimarães, SP, Brazil Texas A&M University-Commerce, Commerce, Texas 75429, USA. Abstract. Light radioactive neutron and proton capture reactions by these radioactive nuclei at energies of astrophysical interest

  8. Radioactive Needlework Reconstruction of needle-positions in radiation treatment

    E-print Network

    Hochstenbach, Michiel

    Radioactive Needlework Reconstruction of needle-positions in radiation treatment Claude Archer1 University, 5: Universiteit Leiden 103 #12;104 Radioactive Needlework Figure 5.1: Position of the device in the desired positions. The radioactive decay of the used iodine or palladium seeds is such that in half a year

  9. Total natural radioactivity, Veneto (Italy) V. Stratia,b

    E-print Network

    Roma "La Sapienza", Università di

    SCIENCE Total natural radioactivity, Veneto (Italy) V. Stratia,b , M. Baldoncinia,c , G.P. Bezzonb the first detailed map of the terrestrial natural radioactivity of the Veneto Region (Italy), a 18,264 km2-purity germanium (HPGe) g-ray spectrometer to characterize the radioactivity content of the 41 cartographic units

  10. Radioactive Materials URPO Check Sheet and Authorisation Process / Task name

    E-print Network

    Bearhop, Stuart

    Radioactive Materials URPO Check Sheet and Authorisation Process / Task name Laboratory RPS name Assessment have been completed URPO Initials Process for use of radioactive material has been approved / No Dosimetry has been received and issued Yes / No Radioactive materials purchased / acquired and delivered

  11. UOP, A Honewell Company CSTs Clean Radioactive Waste in

    E-print Network

    UOP, A Honewell Company CSTs Clean Radioactive Waste in Fukushima and Worldwide Radiation waste to radioactive waste cleanup as part of the long-term effort to remediate radwaste at both government sites lower level radioactive waste can be treated in a way which will be less costly and hazardous

  12. 10 CFR 32.72 - Manufacture, preparation, or transfer for commercial distribution of radioactive drugs containing...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...abbreviation; and the quantity of radioactivity at a specified date and time. For...use instrumentation to measure the radioactivity of radioactive drugs. The licensee...measurements and calculations, the amount of radioactivity in dosages of alpha-, beta-,...

  13. 10 CFR 61.41 - Protection of the general population from releases of radioactivity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...general population from releases of radioactivity. 61.41 Section 61.41 Energy...general population from releases of radioactivity. Concentrations of radioactive...should be made to maintain releases of radioactivity in effluents to the general...

  14. 10 CFR 61.41 - Protection of the general population from releases of radioactivity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...general population from releases of radioactivity. 61.41 Section 61.41 Energy...general population from releases of radioactivity. Concentrations of radioactive...should be made to maintain releases of radioactivity in effluents to the general...

  15. 10 CFR 61.41 - Protection of the general population from releases of radioactivity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...general population from releases of radioactivity. 61.41 Section 61.41 Energy...general population from releases of radioactivity. Concentrations of radioactive...should be made to maintain releases of radioactivity in effluents to the general...

  16. 10 CFR 61.41 - Protection of the general population from releases of radioactivity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...general population from releases of radioactivity. 61.41 Section 61.41 Energy...general population from releases of radioactivity. Concentrations of radioactive...should be made to maintain releases of radioactivity in effluents to the general...

  17. 10 CFR 32.72 - Manufacture, preparation, or transfer for commercial distribution of radioactive drugs containing...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...abbreviation; and the quantity of radioactivity at a specified date and time. For...use instrumentation to measure the radioactivity of radioactive drugs. The licensee...measurements and calculations, the amount of radioactivity in dosages of alpha-, beta-,...

  18. 10 CFR 32.72 - Manufacture, preparation, or transfer for commercial distribution of radioactive drugs containing...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...abbreviation; and the quantity of radioactivity at a specified date and time. For...use instrumentation to measure the radioactivity of radioactive drugs. The licensee...measurements and calculations, the amount of radioactivity in dosages of alpha-, beta-,...

  19. 10 CFR 61.41 - Protection of the general population from releases of radioactivity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...general population from releases of radioactivity. 61.41 Section 61.41 Energy...general population from releases of radioactivity. Concentrations of radioactive...should be made to maintain releases of radioactivity in effluents to the general...

  20. 10 CFR 32.72 - Manufacture, preparation, or transfer for commercial distribution of radioactive drugs containing...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...abbreviation; and the quantity of radioactivity at a specified date and time. For...use instrumentation to measure the radioactivity of radioactive drugs. The licensee...measurements and calculations, the amount of radioactivity in dosages of alpha-, beta-,...

  1. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...shall be posted at each very high radiation area. (d) Airborne radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area....

  2. 10 CFR 32.72 - Manufacture, preparation, or transfer for commercial distribution of radioactive drugs containing...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...abbreviation; and the quantity of radioactivity at a specified date and time. For...use instrumentation to measure the radioactivity of radioactive drugs. The licensee...measurements and calculations, the amount of radioactivity in dosages of alpha-, beta-,...

  3. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...shall be posted at each very high radiation area. (d) Airborne radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area....

  4. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...shall be posted at each very high radiation area. (d) Airborne radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area....

  5. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...shall be posted at each very high radiation area. (d) Airborne radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area....

  6. 10 CFR 835.603 - Radiological areas and radioactive material areas.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...shall be posted at each very high radiation area. (d) Airborne radioactivity area. The words “Caution, Airborne Radioactivity Area” or “Danger, Airborne Radioactivity Area” shall be posted at each airborne radioactivity area....

  7. BIOPROTA: an international forum for environmental modelling in support of long-term radioactive waste management

    SciTech Connect

    Smith, K.L.; Smith, G.; Laciok, A.

    2007-07-01

    An international Forum, BIOPROTA, has been set up and maintained which allows common long-term environmental radiological assessment problems, such as post-closure modelling studies to be identified and then addressed. The focus of the Forum is to address key uncertainties in environmental modelling and related dose assessment with special reference to evaluation of the long-term impact of contaminant releases associated with radioactive waste management. The application of shared resources results in effective resource management and the development of common solutions to common problems. The Forum began in 2002 and has benefited from the knowledge and experience of organisations from Belgium (SCK.CEN), Czech Republic (NRI), Canada (OPG), Finland (Posiva), France (ANDRA, EdF), Japan (NUMO), Korea (KAERI), Norway (NRPA), Spain (ENRESA, CIEMAT), Sweden (SKB, SSI), Switzerland (Nagra), UK (Nirex, Nexia, UKAEA) and the USA (EPRI). These organisations include a mixture of operators, regulators and research institutes, and hence, including the participation of their technical support organizations, constitutes a very broad-based Forum. Enviros has acted as the technical secretariat to the Forum since its formation. Initially the Forum focused on three themes aimed at advancing knowledge and improving model predictions relating to performance and safety assessments: Theme 1 Development of a database to meet the key biosphere assessment information deficiencies. Theme 2 Implementation of a series of tasks to address key modelling issues, including uncertainties and inconsistencies in the modelling of inhalation, irrigation and soil contamination dose pathways; and approaches to the modelling the transfer of radionuclides across the geosphere-biosphere interface zone (GBIZ). Theme 3 Provision of guidance on site characterisation and experimental and monitoring protocols relevant to improving confidence in the biosphere component of the overall performance assessment. Substantial work under Themes 2 and 3 was completed in 2005/06 resulting in the publication of a variety of reports and guidance documents. Results of the model comparisons conducted under Theme 2 suggest that we can be confident in model structures and we have gained knowledge of the sensitive assumptions. Population of the database produced under Theme 1 is ongoing after release of an initial version which focused on data for Cl-36, Se-79, Tc-99, I-129, Np-237 and U-series radionuclides. In 2006, BIOPROTA received further international interest. The 2006 annual workshop identified a series of current issues for which proposals for tasks aimed at addressing these issues are under development. This includes exchange of information on models and processes of relevance to Cl-36 behaviour, as well as modelling the disequilibrium in the U-238 decay chain in environmental systems; more precise understanding of released C-14 distribution within various environmental carbon pools; and studies of the GBIZ under environmental change. A special workshop was held on Cl-36 behaviour and the workshop report published. An overview of the current state of play in biosphere modeling and dose assessment programmes relating to radioactive waste management will be presented based on national presentations by Forum members at the 2007 workshop and the key research outputs developed through the Forum will be described. (authors)

  8. s.haszeldine@ed.ac.uk Radioactive waste Cumbria: Maryport, Silloth 21, 22 Nov 2012 1 Geological disposal of radioactive

    E-print Network

    s.haszeldine@ed.ac.uk Radioactive waste Cumbria: Maryport, Silloth 21, 22 Nov 2012 1 Geological disposal of radioactive waste in Cumbria http://www.geos.ed.ac.uk/homes/rsh/MRWS_2012.html Stuart/rsh/ Allerdale_and_Copeland.html #12;Nuclear power s.haszeldine@ed.ac.uk Radioactive waste Cumbria: Maryport

  9. Handbook of high-level radioactive waste transportation

    SciTech Connect

    Sattler, L.R.

    1992-10-01

    The High-Level Radioactive Waste Transportation Handbook serves as a reference to which state officials and members of the general public may turn for information on radioactive waste transportation and on the federal government`s system for transporting this waste under the Civilian Radioactive Waste Management Program. The Handbook condenses and updates information contained in the Midwestern High-Level Radioactive Waste Transportation Primer. It is intended primarily to assist legislators who, in the future, may be called upon to enact legislation pertaining to the transportation of radioactive waste through their jurisdictions. The Handbook is divided into two sections. The first section places the federal government`s program for transporting radioactive waste in context. It provides background information on nuclear waste production in the United States and traces the emergence of federal policy for disposing of radioactive waste. The second section covers the history of radioactive waste transportation; summarizes major pieces of legislation pertaining to the transportation of radioactive waste; and provides an overview of the radioactive waste transportation program developed by the US Department of Energy (DOE). To supplement this information, a summary of pertinent federal and state legislation and a glossary of terms are included as appendices, as is a list of publications produced by the Midwestern Office of The Council of State Governments (CSG-MW) as part of the Midwestern High-Level Radioactive Waste Transportation Project.

  10. Standard Model tests with trapped radioactive atoms

    E-print Network

    J. A. Behr; G. Gwinner

    2009-03-04

    We review the use of laser cooling and trapping for Standard Model tests, focusing on trapping of radioactive isotopes. Experiments with neutral atoms trapped with modern laser cooling techniques are testing several basic predictions of electroweak unification. For nuclear $\\beta$ decay, demonstrated trap techniques include neutrino momentum measurements from beta-recoil coincidences, along with methods to produce highly polarized samples. These techniques have set the best general constraints on non-Standard Model scalar interactions in the first generation of particles. They also have the promise to test whether parity symmetry is maximally violated, to search for tensor interactions, and to search for new sources of time reversal violation. There are also possibilites for exotic particle searches. Measurements of the strength of the weak neutral current can be assisted by precision atomic experiments using traps of small numbers of radioactive atoms, and sensitivity to possible time-reversal violating electric dipole moments can be improved.

  11. Comparative alkali washing of simulated radioactive sludge

    SciTech Connect

    Fugate, G.A.; Ensor, D.D.; Egan, B.Z.

    1996-10-01

    The treatment of large volumes of radioactive sludge generated from uranium and plutonium recovery processes is a pressing problem in the environmental restoration currently planned at various U.S. Department of Energy sites. This sludge, commonly stored in underground tanks, is mainly in the form of metal oxides or precipitated metal hydroxides and the bulk of this material is nonradioactive. One method being developed to pretreat this waste takes advantage of the amphoteric character of aluminum and other nonradioactive elements. Previous studies have reported on the dissolution of eleven elements from simulated sludge using NaOH solutions up to 6M. This work provides a comparative study using KOH. The effectiveness of the alkali washing as a treatment method to reduce the bulk of radioactive sludge requiring long term isolation will be discussed.

  12. Method of handling radioactive alkali metal waste

    DOEpatents

    Wolson, Raymond D. (Lockport, IL); McPheeters, Charles C. (Plainfield, IL)

    1980-01-01

    Radioactive alkali metal is mixed with particulate silica in a rotary drum reactor in which the alkali metal is converted to the monoxide during rotation of the reactor to produce particulate silica coated with the alkali metal monoxide suitable as a feed material to make a glass for storing radioactive material. Silica particles, the majority of which pass through a 95 mesh screen or preferably through a 200 mesh screen, are employed in this process, and the preferred weight ratio of silica to alkali metal is 7 to 1 in order to produce a feed material for the final glass product having a silica to alkali metal monoxide ratio of about 5 to 1.

  13. Fields of View for Environmental Radioactivity

    E-print Network

    Malins, Alex; Machida, Masahiko; Takemiya, Hiroshi; Saito, Kimiaki

    2015-01-01

    The gamma component of air radiation dose rates is a function of the amount and spread of radioactive nuclides in the environment. These radionuclides can be natural or anthropogenic in origin. The field of view describes the area of radionuclides on, or below, the ground that is responsible for determining the air dose rate, and hence correspondingly the external radiation exposure. This work describes Monte Carlo radiation transport calculations for the field of view under a variety of situations. Presented first are results for natural 40K and thorium and uranium series radionuclides distributed homogeneously within the ground. Results are then described for atmospheric radioactive caesium fallout, such as from the Fukushima Daiichi Nuclear Power Plant accident. Various stages of fallout evolution are considered through the depth distribution of 134Cs and 137Cs in soil. The fields of view for the natural radionuclides and radiocaesium are different. This can affect the responses of radiation monitors to th...

  14. Case of radioactive iodine exposure during pregnancy.

    PubMed

    Sadakata, Hisanobu; Shinozaki, Hiromitsu; Higuchi, Tetsuya; Minegishi, Takashi

    2014-12-01

    A 43-year-old woman (gravida 0, para 0) was diagnosed with thyroid carcinoma and had been receiving radioactive iodine for remnant ablation. Eventually, her pregnant status became apparent; during radiation, she was at 5 gestational weeks. She decided to continue the pregnancy and delivered a boy of 2362?g at 37 gestational weeks. The infant did not present thyroid dysfunction or developmental abnormalities at 2 months of age. The patient was in the early pregnancy stage during radiation, so the fetus did not develop radiation-related damage of the thyroid gland because at this stage, the fetal thyroid does not concentrate iodine. Although the mother had received radioactive iodine during the critical organogenesis period, the fetus did not develop teratogenicity because the radiation was administered at the borderline threshold for teratogenicity. This case suggests the importance of iodine thyroid absorption when considering radiation-related damage to the fetal thyroid gland during early pregnancy. PMID:25130255

  15. Radioactive hot cell access hole decontamination machine

    DOEpatents

    Simpson, William E. (Richland, WA)

    1982-01-01

    Radioactive hot cell access hole decontamination machine. A mobile housing has an opening large enough to encircle the access hole and has a shielding door, with a door opening and closing mechanism, for uncovering and covering the opening. The housing contains a shaft which has an apparatus for rotating the shaft and a device for independently translating the shaft from the housing through the opening and access hole into the hot cell chamber. A properly sized cylindrical pig containing wire brushes and cloth or other disks, with an arrangement for releasably attaching it to the end of the shaft, circumferentially cleans the access hole wall of radioactive contamination and thereafter detaches from the shaft to fall into the hot cell chamber.

  16. Airborne radioactivity surveys for phosphate in Florida

    USGS Publications Warehouse

    Moxham, Robert M.

    1954-01-01

    Airborne radioactivity surveys totaling 5, 600 traverse miles were made in 10 areas in Florida, which were thought to be geologically favorable for deposits of uraniferous phosphate. Abnormal radioactivity was recorded in 8 of the 10 areas surveyed. The anomalies are located in Bradford, Clay, Columbia, DeSoto, Dixie, Lake, Marion, Orange, Sumter, Taylor, and Union Counties. Two of the anomalies were investigated briefly on the ground. One resulted from a deposit of river-pebble phosphate in the Peace River valley; the river-pebble samples contain an average of 0.013 percent equivalent uranium. The other anomaly resulted from outcrops of leached phosphatic rock containing as much as 0. 016 percent equivalent uranium. Several anomalies in other areas were recorded at or near localities where phosphate deposits have been reported.

  17. Various cluster radioactivities above magic nuclei

    E-print Network

    F. R. Xu; J. C. Pei

    2006-03-27

    We present parameter-free tunneling calculations for various cluster radioactivities including the diproton decays of atomic nuclei. An uniform folded cluster potential has been suggested that is based on a self-consistent mean-field model, with the folding factor determined using the quantization conditions of the quasibound cluster state. We have investigated the $\\alpha$-particle and heavier-cluster decays of trans-$^{100}$Sn and trans-$^{208}$Pb nuclei, and the observed diproton emission from the proton drip-line nucleus $^{16}$Ne, showing the overall reasonable descriptions of cluster radioactivities with calculated half-lives agreeing well with experimental data. We have also predicted the properties of yet unobserved cluster decays of the exotic nuclei $^{112,114}$Ba, $^{104}$Te and $^{38}$Ti.

  18. Proton radioactivity with a Yukawa effective interaction

    E-print Network

    T. R. Routray; S. K. Tripathy; B. B. Dash; B. Behera; D. N. Basu

    2011-04-26

    The half lives of proton radioactivity of proton emitters are investigated theoretically. Proton-nucleus interaction potentials are obtained by folding the densities of the daughter nuclei with a finite range effective nucleon-nucleon interaction having Yukawa form. The Wood-Saxon density distributions for the nuclei used in calculating the nuclear as well as the Coulomb interaction potentials are predictions of the interaction. The quantum mechanical tunneling probability is calculated within the WKB framework. These calculations provide reasonable estimates for the observed proton radioactivity lifetimes. The effects of neutron-proton effective mass splitting in neutron rich asymmetric matter as well as the nuclear matter incompressibility on the decay probability are investigated.

  19. Airborne radioactivity surveys for phosphate in Florida

    USGS Publications Warehouse

    Moxham, Robert M.

    1953-01-01

    Airborne radioactivity surveys totalling 5,600 traverse miles were made in ten areas in Florida, which were thought to be geologically favorable for the occurrence of uraniferous phosphate deposits. Abnormal radioactivity was recorded in eight of the ten areas surveyed. The anomalies are located in Bradford, Clay, Columbia, DeSoto, Dixie, Lake, Marion, Orange, Sumter, Taylor, and Union Counties. Two of the anomalies were investigated briefly on the ground. One resulted from a deposit of river-pebble phosphate in the Peace River valley; samples of the river pebble contain an average of 0.013 percent equivalent uranium. The other anomaly resulted from outcrops of leached phosphate rock containing as much as 0.016 percent equivalent uranium. Several anomalies in other areas were recorded at or near localities where phosphate deposits have been reported to occur.

  20. Radioactive targets for nuclear accelerator experiments

    NASA Astrophysics Data System (ADS)

    Maier, H. J.; Grossmann, R.; Friebel, H. U.

    1991-05-01

    The quality of a nuclear accelerator target is assessed in terms of its purity, mechanical strength, thickness uniformity and microstructure. High vacuum thin film condensation is the preferred production method, because it results in microscopically smooth targets of high purity. Special variants of this technique are used in our hot laboratory to prepare radioactive targets of good macroscopic and microscopic homogeneity while keeping the consumption of isotopic material on a low level. A particular type of carbon backing provides excellent mechanical strength to the targets. New equipment including modern production plants as well as glove boxes and hot cell facilities permits to maintain the service for a long period. In nuclear physics experiments with radioactive targets problems may arise from a possible contamination of the beam line or other equipment. A few protective measures to overcome these difficulties are mentioned.

  1. Radioactive scrap metal decontamination technology assessment report

    SciTech Connect

    Buckentin, J.M.; Damkroger, B.K.; Schlienger, M.E.

    1996-04-01

    Within the DOE complex there exists a tremendous quantity of radioactive scrap metal. As an example, it is estimated that within the gaseous diffusion plants there exists in excess of 700,000 tons of contaminated stainless steel. At present, valuable material is being disposed of when it could be converted into a high quality product. Liquid metal processing represents a true recycling opportunity for this material. By applying the primary production processes towards the material`s decontamination and re-use, the value of the strategic resource is maintained while drastically reducing the volume of material in need of burial. Potential processes for the liquid metal decontamination of radioactively contaminated metal are discussed and contrasted. Opportunities and technology development issues are identified and discussed. The processes compared are: surface decontamination; size reduction, packaging and burial; melting technologies; electric arc melting; plasma arc centrifugal treatment; air induction melting; vacuum induction melting; and vacuum induction melting and electroslag remelting.

  2. Solar Powered Radioactive Air Monitoring Stations

    SciTech Connect

    Barnett, J. M.; Bisping, Lynn E.; Gervais, Todd L.

    2013-10-30

    Environmental monitoring of ambient air for radioactive material is required as stipulated in the PNNL Site radioactive air license. Sampling ambient air at identified preferred locations could not be initially accomplished because utilities were not readily available. Therefore, solar powered environmental monitoring systems were considered as a possible option. PNNL purchased two 24-V DC solar powered environmental monitoring systems which consisted of solar panels, battery banks, and sampling units. During an approximate four month performance evaluation period, the solar stations operated satisfactorily at an on-site test location. They were subsequently relocated to their preferred locations in June 2012 where they continue to function adequately under the conditions found in Richland, Washington.

  3. Radioactive materials released from nuclear power plants

    SciTech Connect

    Tichler, J.; Norden, K.; Congemi, J. )

    1989-10-01

    Releases of radioactive materials in airborne and liquid effluents from commercial light water reactors during 1987 have been compiled and reported. Data on solid waste shipments as well as selected operating information have been included. This report supplements earlier annual reports issued by the former Atomic Energy Commission and the Nuclear Regulatory Commission. The 1987 release data are summarized in tabular form. Data covering specific radionuclides are summarized. 16 tabs.

  4. (Low-level radioactive waste management techniques)

    SciTech Connect

    Van Hoesen, S.D.; Kennerly, J.M.; Williams, L.C.; Lingle, W.N.; Peters, M.S.; Darnell, G.R.; USDOE Oak Ridge Operations Office, TN; Du Pont de Nemours and Co., Aiken, SC . Savannah River Plant; Idaho National Engineering Lab., Idaho Falls, ID )

    1988-08-08

    The US team consisting of representatives of Oak Ridge National Laboratory (ORNL), Savannah River plant (SRP), Idaho National Engineering Laboratory (INEL), and the Department of Energy, Oak Ridge Operations participated in a training program on French low-level radioactive waste (LLW) management techniques. Training in the rigorous waste characterization, acceptance and certification procedures required in France was provided at Agence Nationale pour les Gestion des Dechets Radioactif (ANDRA) offices in Paris.

  5. A New Interpretation of Cluster Radioactivity Mechanism

    NASA Astrophysics Data System (ADS)

    Cherepanov, E. A.; Volkov, V. V.

    2015-11-01

    The basis for cluster radioactivity is the property of nuclei of light isotopes of elements heavier than lead to spontaneously form clusters -- nuclei of light elements -- from valence nucleons, which gives rise to asymmetric nuclear molecules. The cluster formation proceeds through successive excitation-free transfer of valence nucleons to the ? particle and to subsequent light nuclei. Nuclear molecule formation is accompanied by a considerable amount of released energy, which allows quantum-mechanical penetration of the cluster through the exit Coulomb barrier.

  6. Novel techniques to search for neutron radioactivity

    E-print Network

    M. Thoennessen; G. Christian; Z. Kohley; T. Baumann; M. Jones; J. K. Smith; J. Snyder; A. Spyrou

    2013-07-08

    Two new methods to observe neutron radioactivity are presented. Both methods rely on the production and decay of the parent nucleus in flight. The relative velocity measured between the neutron and the fragment is sensitive to half-lives between ~1 and ~100 ps for the Decay in Target (DiT) method. The transverse position measurement of the neutron in the Decay in a Magnetic Field (DiMF) method is sensitive to half-lives between 10 ps and 1 ns.

  7. A Simple Example of Radioactive Dating

    ERIC Educational Resources Information Center

    Brown, Todd

    2014-01-01

    Although nuclear half-life is vital to physics and physical science, and to sensitive societal issues from nuclear waste to the age of the Earth, a true lab on half-life is almost never done at the college or high school level. Seldom are students able to use radioactivity to actually date when an object came into being, as is done in this…

  8. Electrically Driven Technologies for Radioactive Aerosol Abatement

    SciTech Connect

    David W. DePaoli; Ofodike A. Ezekoye; Costas Tsouris; Valmor F. de Almeida

    2003-01-28

    The purpose of this research project was to develop an improved understanding of how electriexecy driven processes, including electrocoalescence, acoustic agglomeration, and electric filtration, may be employed to efficiently treat problems caused by the formation of aerosols during DOE waste treatment operations. The production of aerosols during treatment and retrieval operations in radioactive waste tanks and during thermal treatment operations such as calcination presents a significant problem of cost, worker exposure, potential for release, and increased waste volume.

  9. Soils: man-caused radioactivity and radiation forecast

    SciTech Connect

    Gablin, Vassily

    2007-07-01

    Available in abstract form only. Full text of publication follows: One of the main tasks of the radiation safety guarantee is non-admission of the excess over critical radiation levels. In Russia they are man-caused radiation levels. Meanwhile any radiation measurement represents total radioactivity. That is why it is hard to assess natural and man-caused contributions to total radioactivity. It is shown that soil radioactivity depends on natural factors including radioactivity of rocks and cosmic radiation as well as man-caused factors including nuclear and non-nuclear technologies. Whole totality of these factors includes unpredictable (non-deterministic) factors - nuclear explosions and radiation accidents, and predictable ones (deterministic) - all the rest. Deterministic factors represent background radioactivity whose trends is the base of the radiation forecast. Non-deterministic factors represent man-caused radiation treatment contribution which is to be controlled. This contribution is equal to the difference in measured radioactivity and radiation background. The way of calculation of background radioactivity is proposed. Contemporary soils are complicated technologically influenced systems with multi-leveled spatial and temporary inhomogeneity of radionuclides distribution. Generally analysis area can be characterized by any set of factors of soil radioactivity including natural and man-caused factors. Natural factors are cosmic radiation and radioactivity of rocks. Man-caused factors are shown on Fig. 1. It is obvious that man-caused radioactivity is due to both artificial and natural emitters. Any result of radiation measurement represents total radioactivity i.e. the sum of activities resulting from natural and man-caused emitters. There is no gauge which could separately measure natural and man-caused radioactivity. That is why it is so hard to assess natural and man-caused contributions to soil radioactivity. It would have been possible if human activity had led to contamination of soil only by artificial radionuclides. But we can view a totality of soil radioactivity factors in the following way. (author)

  10. Radioactive Waste Burial Grounds. Environmental Information Document

    SciTech Connect

    Jaegge, W.J.; Kolb, N.L.; Looney, B.B.; Marine, I.W.; Towler, O.A.; Cook, J.R.

    1987-03-01

    This document provides environmental information on postulated closure options for the Radioactive Waste Burial Grounds at the Savannah River Plant and was developed as background technical documentation for the Department of Energy`s proposed Environmental Impact Statement (EIS) on waste management activities for groundwater protection at the plant. The results of groundwater and atmospheric pathway analyses, accident analysis, and other environmental assessments discussed in this document are based upon a conservative analysis of all foreseeable scenarios as defined by the National Environmental Policy Act (CFR, 1986). The scenarios do not necessarily represent actual environmental conditions. This document is not meant to be used as a closure plan or other regulatory document to comply with required federal or state environmental regulations. The closure options considered for the Radioactive Waste Burial Grounds are waste removal and closure, no waste removal and closure, and no action. The predominant pathways for human exposure to chemical and/or radioactive constituents are through surface, subsurface, and atmospheric transport. Modeling calculations were made to determine the risks to human population via these general pathways for the three postulated closure options. An ecological assessment was conducted to predict the environmental impacts on aquatic and terrestrial biota. The relative costs for each of the closure options were estimated.

  11. Metabolic fate of radioactive acyclovir in humans

    SciTech Connect

    de Miranda, P.; Good, S.S.; Krasny, H.C.; Connor, J.D.; Laskin, O.L.; Lietman, P.S.

    1982-07-20

    The metabolic fate and the kinetics of elimination of (8-/sup 14/C)acyclovir in plasma and blood was investigated in five cancer patients. Doses of 0.5 and 2.5 mg/kg were administered by one-hour intravenous infusion. Radioactivity was distributed nearly equally in blood and plasma. The plasma and blood concentration-time data were defined by a two-compartment open pharmacokinetic model. The overall mean acyclovir plasma half-life and total body clearance +/- SD were 2.1 +/- 0.5 hours and 297 +/- 53 ml/min/1.73 m2. Binding of acyclovir to plasma proteins was 15.4 +/- 4.4 percent. The radioactive dose was excreted predominantly in the urine (71 to 99 percent) with less than 2 percent excretion in the feces and only trace amounts of radioactivity in the expired air. Reverse-phase high-performance liquid chromatography indicated that 9-carboxymethoxymethylguanine was the only significant urinary metabolite of acyclovir accounting for 8.5 to 14.1 percent of the dose. A minor metabolite (less than 0.2 percent of dose) had the retention time of 8-hydroxy-9-(2-hydroxyethoxymethyl)guanine. Unchanged urinary acyclovir ranged from 62 to 91 percent of the dose. There was no indication of acyclovir cleavage to guanine. The renal clearances of acyclovir were three times higher than the corresponding creatinine clearances.

  12. RESRAD. Site-Specific Residual Radioactivity

    SciTech Connect

    Yu, C.

    1989-06-01

    RESRAD is designed to derive site-specific guidelines for allowable residual concentrations of radionuclides in soil. A guideline is defined as a radionuclide concentration or a level of radiation or radioactivity that is acceptable if a site is to be used without radiological restrictions. Guidelines are expressed as (1) concentrations of residual radionuclides in soil, (2) concentrations of airborne radon decay products, (3) levels of external gamma radiation, (4) levels of radioactivity from surface contamination, and (5) concentrations of residual radionuclides in air and water. Soil is defined as unconsolidated earth material, including rubble and debris that may be present. The controlling principles of all guidelines are (1) the annual radiation dose received by a member of the critical population group from the residual radioactive material - predicted by a realistic but reasonably conservative analysis and averaged over a 50 year period - should not exceed 100 mrem/yr, and (2) doses should be kept as low as reasonably achievable. All significant exposure pathways for the critical population group are considered in deriving soil guidelines. These pathways include direct exposure to external radiation from the contaminated soil material; internal radiation from inhalation of airborne radionuclides; and internal radiation from ingestion of plant foods grown in the contaminated soil, meat and milk from livestock fed with contaminated fodder and water, drinking water from a contaminated well, and fish from a contaminated pond.

  13. Geological problems in radioactive waste isolation

    SciTech Connect

    Witherspoon, P.A.

    1991-01-01

    The problem of isolating radioactive wastes from the biosphere presents specialists in the fields of earth sciences with some of the most complicated problems they have ever encountered. This is especially true for high level waste (HLW) which must be isolated in the underground and away from the biosphere for thousands of years. Essentially every country that is generating electricity in nuclear power plants is faced with the problem of isolating the radioactive wastes that are produced. The general consensus is that this can be accomplished by selecting an appropriate geologic setting and carefully designing the rock repository. Much new technology is being developed to solve the problems that have been raised and there is a continuing need to publish the results of new developments for the benefit of all concerned. The 28th International Geologic Congress that was held July 9--19, 1989 in Washington, DC provided an opportunity for earth scientists to gather for detailed discussions on these problems. Workshop W3B on the subject, Geological Problems in Radioactive Waste Isolation -- A World Wide Review'' was organized by Paul A Witherspoon and Ghislain de Marsily and convened July 15--16, 1989 Reports from 19 countries have been gathered for this publication. Individual papers have been cataloged separately.

  14. Future radioactive liquid waste streams study

    SciTech Connect

    Rey, A.S.

    1993-11-01

    This study provides design planning information for the Radioactive Liquid Waste Treatment Facility (RLWTF). Predictions of estimated quantities of Radioactive Liquid Waste (RLW) and radioactivity levels of RLW to be generated are provided. This information will help assure that the new treatment facility is designed with the capacity to treat generated RLW during the years of operation. The proposed startup date for the RLWTF is estimated to be between 2002 and 2005, and the life span of the facility is estimated to be 40 years. The policies and requirements driving the replacement of the current RLW treatment facility are reviewed. Historical and current status of RLW generation at Los Alamos National Laboratory are provided. Laboratory Managers were interviewed to obtain their insights into future RLW activities at Los Alamos that might affect the amount of RLW generated at the Lab. Interviews, trends, and investigation data are analyzed and used to create scenarios. These scenarios form the basis for the predictions of future RLW generation and the level of RLW treatment capacity which will be needed at LANL.

  15. Packaging and transportation of radioactively contaminated lead

    SciTech Connect

    Gleason, Eugene; Holden, Gerard

    2007-07-01

    Under the management of the Nuclear Decommissioning Authority (NDA) the government of the United Kingdom has launched an ambitious program to remediate the nation's nuclear waste legacy. Over a twenty-five year period NDA plans to decommission several first generation nuclear power plants and other radioactive facilities. The use innovative, safe 'fit for purpose' technologies will be a major part of this complex program. This paper will present a case study of a recently completed project undertaken in support of the nuclear decommissioning activities at the Sellafield site in the United Kingdom. The focus is on an innovative application of new packaging technology developed for the safe transportation of radioactively contaminated lead objects. Several companies collaborated on the project and contributed to its safe and successful conclusion. These companies include British Nuclear Group, Gravatom Engineering, W. F. Bowker Transport, Atlantic Container Lines, MHF Logistical Solutions and Energy Solutions. New containers and a new innovative inter-modal packaging system to transport the radioactive lead were developed and demonstrated during the project. The project also demonstrated the potential contribution of international nuclear recycling activities as a safe, economic and feasible technical option for nuclear decommissioning in the United Kingdom. (authors)

  16. Integration of Radioactive Material with Microcalorimeter Detectors

    NASA Astrophysics Data System (ADS)

    Croce, M. P.; Bond, E. M.; Hoover, A. S.; Kunde, G. J.; Moody, W. A.; Rabin, M. W.; Bennett, D. A.; Hayes-Wehle, J.; Kotsubo, V.; Schmidt, D. R.; Ullom, J. N.

    2014-09-01

    Microcalorimeter detectors with embedded radioactive material offer many possibilities for new types of measurements and applications. We will discuss the designs and methods that we are developing for precise deposition of radioactive material and its encapsulation in the absorber of transition-edge sensor (TES) microcalorimeter detectors for two specific applications. The first application is total nuclear reaction energy (Q) spectroscopy for nuclear forensics measurements of trace actinide samples, where the goal is determination of ratios of isotopes with Q values in the range of 5-7 MeV. Simplified, rapid sample preparation and detector assembly is necessary for practical measurements, while maintaining good energy resolution. The second application is electron capture spectroscopy of isotopes with low Q values, such as Ho, for measurement of neutrino mass. Detectors for electron capture spectroscopy are designed for measuring energies up to approximately 6 keV. Their smaller heat capacity and physical size present unique challenges. Both applications require precise deposition of radioactive material and encapsulation in an absorber with optimized thermal properties and coupling to the TES. We have made detectors for both applications with a variety of designs and assembly methods, and will present their development.

  17. Radioactive iodine therapy in cats with hyperthyroidism

    SciTech Connect

    Turrel, J.M.; Feldman, E.C.; Hays, M.; Hornof, W.J.

    1984-03-01

    Eleven cats with hyperthyroidism were treated with radioactive iodine (/sup 131/I). Previous unsuccessful treatments for hyperthyroidism included hemithyroidectomy (2 cats) and an antithyroid drug (7 cats). Two cats had no prior treatment. Thyroid scans, using technetium 99m, showed enlargement and increased radionuclide accumulation in 1 thyroid lobe in 5 cats and in both lobes in 6 cats. Serum thyroxine concentrations were high and ranged from 4.7 to 18 micrograms/dl. Radioactive iodine tracer studies were used to determine peak radioactive iodine uptake (RAIU) and effective and biological half-lives. Activity of /sup 131/I administered was calculated from peak RAIU, effective half-life, and estimated thyroid gland weight. Activity of /sup 131/I administered ranged from 1.0 to 5.9 mCi. The treatment goal was to deliver 20,000 rad to hyperactive thyroid tissue. However, retrospective calculations based on peak RAIU and effective half-life obtained during the treatment period showed that radiation doses actually ranged from 7,100 to 64,900 rad. Complete ablation of the hyperfunctioning thyroid tissue and a return to euthyroidism were seen in 7 cats. Partial responses were seen in 2 cats, and 2 cats became hypothyroid. It was concluded that /sup 131/I ablation of thyroid tumors was a reasonable alternative in the treatment of hyperthyroidism in cats. The optimal method of dosimetry remains to be determined.

  18. Radioactive waste management in the former USSR

    SciTech Connect

    Bradley, D.J.

    1992-06-01

    Radioactive waste materials--and the methods being used to treat, process, store, transport, and dispose of them--have come under increased scrutiny over last decade, both nationally and internationally. Nuclear waste practices in the former Soviet Union, arguably the world's largest nuclear waste management system, are of obvious interest and may affect practices in other countries. In addition, poor waste management practices are causing increasing technical, political, and economic problems for the Soviet Union, and this will undoubtedly influence future strategies. this report was prepared as part of a continuing effort to gain a better understanding of the radioactive waste management program in the former Soviet Union. the scope of this study covers all publicly known radioactive waste management activities in the former Soviet Union as of April 1992, and is based on a review of a wide variety of literature sources, including documents, meeting presentations, and data base searches of worldwide press releases. The study focuses primarily on nuclear waste management activities in the former Soviet Union, but relevant background information on nuclear reactors is also provided in appendixes.

  19. Waste minimization for commercial radioactive materials users generating low-level radioactive waste. Revision 1

    SciTech Connect

    Fischer, D.K.; Gitt, M.; Williams, G.A.; Branch, S.; Otis, M.D.; McKenzie-Carter, M.A.; Schurman, D.L.

    1991-07-01

    The objective of this document is to provide a resource for all states and compact regions interested in promoting the minimization of low-level radioactive waste (LLW). This project was initiated by the Commonwealth of Massachusetts, and Massachusetts waste streams have been used as examples; however, the methods of analysis presented here are applicable to similar waste streams generated elsewhere. This document is a guide for states/compact regions to use in developing a system to evaluate and prioritize various waste minimization techniques in order to encourage individual radioactive materials users (LLW generators) to consider these techniques in their own independent evaluations. This review discusses the application of specific waste minimization techniques to waste streams characteristic of three categories of radioactive materials users: (1) industrial operations using radioactive materials in the manufacture of commercial products, (2) health care institutions, including hospitals and clinics, and (3) educational and research institutions. Massachusetts waste stream characterization data from key radioactive materials users in each category are used to illustrate the applicability of various minimization techniques. The utility group is not included because extensive information specific to this category of LLW generators is available in the literature.

  20. Waste minimization for commercial radioactive materials users generating low-level radioactive waste

    SciTech Connect

    Fischer, D.K.; Gitt, M.; Williams, G.A.; Branch, S. ); Otis, M.D.; McKenzie-Carter, M.A.; Schurman, D.L. )

    1991-07-01

    The objective of this document is to provide a resource for all states and compact regions interested in promoting the minimization of low-level radioactive waste (LLW). This project was initiated by the Commonwealth of Massachusetts, and Massachusetts waste streams have been used as examples; however, the methods of analysis presented here are applicable to similar waste streams generated elsewhere. This document is a guide for states/compact regions to use in developing a system to evaluate and prioritize various waste minimization techniques in order to encourage individual radioactive materials users (LLW generators) to consider these techniques in their own independent evaluations. This review discusses the application of specific waste minimization techniques to waste streams characteristic of three categories of radioactive materials users: (1) industrial operations using radioactive materials in the manufacture of commercial products, (2) health care institutions, including hospitals and clinics, and (3) educational and research institutions. Massachusetts waste stream characterization data from key radioactive materials users in each category are used to illustrate the applicability of various minimization techniques. The utility group is not included because extensive information specific to this category of LLW generators is available in the literature.

  1. The Spanish General Radioactive Waste Management Plan

    SciTech Connect

    Espejo, J.M.; Abreu, A.

    2008-07-01

    This paper mainly describes the strategies, the necessary actions and the technical solutions to be developed by ENRESA in the short, medium and long term, aimed at ensuring the adequate management of radioactive waste, the dismantling and decommissioning of nuclear and radioactive facilities and other activities, including economic and financial measures required to carry them out. Starting with the Spanish administrative organization in this field, which identifies the different agents involved and their roles, and after referring to the waste generation, the activities to be performed in the areas of LILW, SF and HLW management, decommissioning of installations and others are summarized. Finally, the future management costs are estimated and the financing system currently in force is explained. The so-called Sixth General Radioactive Waste Plan (6. GRWP), approved by the Spanish Government, is the 'master document' of reference where all the above mentioned issues are contemplated. In summary: The 6. GRWP includes the strategies and actions to be performed by Enresa in the coming years. The document, revised by the Government and subject to a process of public information, underlines the fact that Spain possesses an excellent infrastructure for the safe and efficient management of radioactive waste, from the administrative, technical and economic-financial points of view. From the administrative point of view there is an organisation, supported by ample legislative developments, that contemplates and governs the main responsibilities of the parties involved in the process (Government, CSN, ENRESA and waste producers). As regards the technical aspect, the experience accumulated to date by Enresa is particularly significant, as are the technologies now available in the field of management and for dismantling processes. As regards the economic-financial basis, a system is in place that guarantees the financing of radioactive waste management costs. This system is based on the generation of funds up front, during the operating lifetime of the facilities, through the application of fees established by Statutory provisions. Finally, a mandatory mechanism of annual revision for both technical issues and economic and financial aspects, allows to have updated all the courses of action. (authors)

  2. Magnetic nanostructures: radioactive probes and recent developments

    NASA Astrophysics Data System (ADS)

    Prandolini, M. J.

    2006-05-01

    The miniaturization of magnetic sensors and storage devices down to the nano-scale leads to drastic changes in magnetic phenomena compared with the same devices with a larger size. Excited-nuclear-probe (radioactive probe) techniques are ideal for investigating these new magnetic nanostructures. By observing the magnetic hyperfine fields (and in some cases the electric-field-gradients (EFGs)) at the nuclei of radioactive probes, microscopic information about the magnetic environment of the probes is acquired. The magnetic hyperfine field is particularly sensitive to the s-spin polarization of the conduction electrons and to the orbital magnetic moment of the probe atom. Three methods of inserting radioactive probes into magnetic nanostructures are presented; neutron activation, recoil implantation and 'soft-landing', followed by descriptions of their application to selected examples. In some cases, these methods offer the simultaneous creation and observation of new magnetic materials at the atomic scale. This review focuses firstly on the induced magnetism in noble-metal spacer layers between either ferromagnetic (FM) or FM/antiferromagnetic (AFM) layers in a trilayer structure. Using the method of low-temperature nuclear orientation, the s-spin polarization of noble-metal probes was measured and was found to be very sensitive to the magnetic properties at both the FM and AFM interfaces. Secondly, the recoil implantation of radioactive Fe probes into rare-earth hosts and d-band alloys and subsequent measurement using time-differential perturbed angular distribution offer the possibility of controlling the chemical composition and number of nearest-neighbours. This method was used to prepare local 3d-magnetic clusters in a non-magnetic matrix and to observe their magnetic behaviour. Finally, non-magnetic radioactive probes were 'soft-landed' onto Ni surfaces and extremely lattice-expanded ultrathin Ni films. By measuring the magnetic hyperfine fields and EFGs at 111Cd probes using time-differential perturbed angular correlation (TDPAC), it was possible to distinguish the interaction of Cd probes located at various surface sites, i.e. atop terraces, within terraces, at steps and at corners. These experimental results are compared with the ground-state properties determined by ab initio density-functional theory. This article was invited by Professor S Washburn.

  3. Novel Solvent for the Simultaneous recovery of Radioactive Nuclides from Liquid Radioactive Wastes

    SciTech Connect

    Romanovskiy, Valeriy Nicholiavich; Smirnov, Lgor V.; Babain, Vasiliy A.; Todd, Terry A.; Brewer, Ken N.

    1999-10-07

    The present invention relates to solvents, and methods, for selectively extracting and recovering radionuclides, especially cesium and strontium, rare earths and actinides from liquid radioactive wastes. More specifically, the invention relates to extracting agent solvent compositions comprising complex organoboron compounds, substituted polyethylene glycols, and neutral organophosphorus compounds in a diluent. The preferred solvent comprises a chlorinated cobalt dicarbollide, diphenyl-dibutylmethylenecarbamoylphosphine oxide, PEG-400, and a diluent of phenylpolyfluoroalkyl sulfone. The invention also provides a method of using the invention extracting agents to recover cesium, strontium, rare earths and actinides from liquid radioactive waste.

  4. Mobility of Po and U-isotopes under acid mine drainage conditions: an experimental approach with samples from Río Tinto area (SW Spain).

    PubMed

    Barbero, L; Gázquez, M J; Bolívar, J P; Casas-Ruiz, M; Hierro, A; Baskaran, M; Ketterer, M E

    2014-12-01

    Under acid mine drainage (AMD) conditions, the solubilities and mobilities of many elements are vastly different from conditions prevailing in most natural waters. Studies are underway in the Río Tinto area (Iberian Pyrite Belt), in order to understand the behavior and mobility of long-lived U-series radionuclides under AMD conditions. A set of leaching experiments utilizing typical country rocks from the Tinto River basin, waste rock pile composite materials, iron-rich riverbed sediments and gossan (weathered naturally rock) were performed towards this purpose. Initial leaching experiments using distilled water kept in contact with solid material for 300, 100, 50 and 1 h resulted in very low concentrations of U with (234)U/(238)U activity ratios close to equilibrium and activity concentrations of (210)Po < 0.03 mBq/g. Leaching experiments performed with sulfuric acid media (0.1 and 0.01 M), and contact times between the solid and solution for 24 h were conducted to quantify the amount of U-isotopes and (210)Po leached, and the radioactive disequilibria generated between the radionuclides in the leachate. These experiments show that Po mobility in acidic conditions (pH around 1-2) is very low, with (210)Po activity in the leachate to be 6% in average for the solid sample. By contrast, mobility of U-isotopes is higher than that of Po, around 1.2%. PMID:24308958

  5. Upgrading the Radioactive Waste Management Infrastructure in Azerbaijan

    SciTech Connect

    Huseynov, A.; Batyukhnova, O.; Ojovan, M.; Rowat, J.

    2007-07-01

    Radionuclide uses in Azerbaijan are limited to peaceful applications in the industry, medicine, agriculture and research. The Baku Radioactive Waste Site (BRWS) 'IZOTOP' is the State agency for radioactive waste management and radioactive materials transport. The radioactive waste processing, storage and disposal facility is operated by IZOTOP since 1963 being significantly upgraded from 1998 to be brought into line with international requirements. The BRWS 'IZOTOP' is currently equipped with state-of-art devices and equipment contributing to the upgrade the radioactive waste management infrastructure in Azerbaijan in line with current internationally accepted practices. The IAEA supports Azerbaijan specialists in preparing syllabus and methodological materials for the Training Centre that is currently being organized on the base of the Azerbaijan BRWS 'IZOTOPE' for education of specialists in the area of safety management of radioactive waste: collection, sorting, processing, conditioning, storage and transportation. (authors)

  6. [Reduction of radioactive cesium content in pond smelt by cooking].

    PubMed

    Nabeshi, Hiromi; Tsutsumi, Tomoaki; Hachisuka, Akiko; Matsuda, Rieko

    2013-01-01

    In Japan, seafood may be eaten raw or after having been cooked in diverse ways. Therefore, it is important to understand the effect of cooking on the extent of contamination with radioactive materials in order to avoid internal exposure to radioactive materials via seafood. In this study, we investigated the changes in radioactive cesium content in pond smelt cooked in four different ways: grilled, stewed (kanroni), fried and soaked (nanbanzuke). The radioactive cesium content in grilled, kanroni and fried pond smelt was almost unchanged compared with the uncooked state. In contrast, radioactive cesium content in nanbanzuke pond smelt was decreased by about 30%. Our result suggests that soaking cooked pond smelt in seasoning is an effective method of reducing the burden radioactive cesium. PMID:24025209

  7. Environmental Assessment Radioactive Source Recovery Program

    SciTech Connect

    1995-12-20

    In a response to potential risks to public health and safety, the U.S. Department of Energy (DOE) is evaluating the recovery of sealed neutron sources under the Radioactive Source Recovery Program (RSRP). This proposed program would enhance the DOE`s and the U.S. Nuclear Regulatory Commission`s (NRC`s) joint capabilities in the safe management of commercially held radioactive source materials. Currently there are no federal or commercial options for the recovery, storage, or disposal of sealed neutron sources. This Environmental Assessment (EA) analyzes the potential environmental impacts that would be expected to occur if the DOE were to implement a program for the receipt and recovery at the Los Alamos National Laboratory (LANL), Los Alamos, New Mexico, of unwanted and excess plutonium-beryllium ({sup 238}Pu-Be) and americium-beryllium ({sup 241}Am-Be) sealed neutron sources. About 1 kg (2.2 lb) plutonium and 3 kg (6.6 lb) americium would be recovered over a 15-year project. Personnel at LANL would receive neutron sources from companies, universities, source brokers, and government agencies across the country. These neutron sources would be temporarily stored in floor holes at the CMR Hot Cell Facility. Recovery reduces the neutron emissions from the source material and refers to a process by which: (1) the stainless steel cladding is removed from the neutron source material, (2) the mixture of the radioactive material (Pu-238 or Am-241) and beryllium that constitutes the neutron source material is chemically separated (recovered), and (3) the recovered Pu-238 or Am-241 is converted to an oxide form ({sup 238}PuO{sub 2} or {sup 241}AmO{sub 2}). The proposed action would include placing the {sup 238}PuO{sub 2} or {sup 241}AmO{sub 2} in interim storage in a special nuclear material vault at the LANL Plutonium Facility.

  8. System for handling and storing radioactive waste

    DOEpatents

    Anderson, J.K.; Lindemann, P.E.

    1982-07-19

    A system and method are claimed for handling and storing spent reactor fuel and other solid radioactive waste, including canisters to contain the elements of solid waste, storage racks to hold a plurality of such canisters, storage bays to store these racks in isolation by means of shielded doors in the bays. This system also includes means for remotely positioning the racks in the bays and an access tunnel within which the remotely operated means is located to position a rack in a selected bay. The modular type of these bays will facilitate the construction of additional bays and access tunnel extension.

  9. System for handling and storing radioactive waste

    DOEpatents

    Anderson, John K. (San Diego, CA); Lindemann, Paul E. (Escondido, CA)

    1984-01-01

    A system and method for handling and storing spent reactor fuel and other solid radioactive waste, including canisters to contain the elements of solid waste, storage racks to hold a plurality of such canisters, storage bays to store these racks in isolation by means of shielded doors in the bays. This system also includes means for remotely positioning the racks in the bays and an access tunnel within which the remotely operated means is located to position a rack in a selected bay. The modular type of these bays will facilitate the construction of additional bays and access tunnel extension.

  10. Economic feasibility of radioactive scrap steel recycling

    SciTech Connect

    Balhiser, R.; Rosholt, D.; Nichols, F.

    1995-12-31

    The goal of MSE`s Radioactive Scrap Steel (RSS) Recycle Program is to develop practical methods for recycling RSS into useful product. This paper provides interim information about ongoing feasibility investigations that are scheduled for completion by September 1995. The project approach, major issues, and cost projections are outlined. Current information indicates that a cost effective RSS Recycling Facility can be designed, built, and in operation by 1999. The RSS team believes that high quality steel plate can be made from RSS at a conversion cost of $1500 per ton or less.

  11. Plutonium-244: confirmation as an extinct radioactivity.

    PubMed

    Alexander, E C; Lewis, R S; Reynolds, J H; Michel, M C

    1971-05-21

    The mass spectrum of xenon from spontaneous fission in a laboratory sample of plutonium-244 is precisely what meteoriticists predicted it would be; this discovery completes a web of proof that this nuclide is a bona fide extinct radioactivity of galactic origin, that r-process nucleosynthesis was ongoing in the galaxy at the time of the birth of the sun, and that the early meteoritic abundances of plutonium-244, heretofore tentative, can be utilized with confidence in models for the chronology of galactic nucleosynthesis. The search for an explanation for anomalous fission-like xenon in carbonaceous chondrites can now be narrowed. PMID:17792940

  12. Some Perspectives on Future Proton Radioactivity Experiments

    SciTech Connect

    Page, R. D.

    2011-11-30

    Understanding the phenomenon of one-proton emission is crucial for addressing the question of the location of the limits of observable nuclei. Much of the current understanding of this radioactive decay process has been developed and refined through measurements of proton emitters above Z = 50, where {approx}30 proton-emitting nuclei have already been discovered and studied. However, despite the great experimental and theoretical efforts over recent years, some important questions remain unanswered. Possibilities for future experiments to tackle some of these issues are considered.

  13. Proton radioactivity half lives with Skyrme interactions

    E-print Network

    T. R. Routray; Abhishek Mishra; S. K. Tripathy; B. Behera; D. N. Basu

    2012-05-31

    The potential barrier impeding the spontaneous emission of protons in the proton radioactive nuclei is calculated as the sum of nuclear, Coulomb and centrifugal contributions. The nuclear part of the proton-nucleus interaction potential is obtained in the energy density formalism using Skyrme effective interaction that results into a simple algebraic expression. The half-lives of the proton emitters are calculated for the different Skyrme sets within the improved WKB framework. The results are found to be in reasonable agreement with the earlier results obtained for more complicated calculations involving finite range interactions.

  14. Particle beam generator using a radioactive source

    DOEpatents

    Underwood, D.G.

    1993-03-30

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  15. Heavy particle radioactivities of superheavy nuclei

    E-print Network

    D. N. Poenaru; R. A. Gherghescu; W. Greiner

    2011-08-13

    The concept of heavy particle radioactivity (HPR) is changed to allow emitted particles with Z_e>28 from parents with Z>110 and daughter around 208Pb. Calculations for superheavy (SH) nuclei with Z=104-124 are showing a trend toward shorter half-lives and larger branching ratio relative to alpha decay for heavier SHs. It is possible to find regions in which HPR is stronger than alpha decay. The new mass table AME11 and the theoretical KTUY05 and FRDM95 masses are used to determine the released energy. For 124 we found isotopes with half-lives in the range of ns to ps.

  16. Hanford Site radioactive hazardous materials packaging directory

    SciTech Connect

    McCarthy, T.L.

    1995-12-01

    The Hanford Site Radioactive Hazardous Materials Packaging Directory (RHMPD) provides information concerning packagings owned or routinely leased by Westinghouse Hanford Company (WHC) for offsite shipments or onsite transfers of hazardous materials. Specific information is provided for selected packagings including the following: general description; approval documents/specifications (Certificates of Compliance and Safety Analysis Reports for Packaging); technical information (drawing numbers and dimensions); approved contents; areas of operation; and general information. Packaging Operations & Development (PO&D) maintains the RHMPD and may be contacted for additional information or assistance in obtaining referenced documentation or assistance concerning packaging selection, availability, and usage.

  17. RECLAMATION OF RADIOACTIVE MATERIAL PACKAGING COMPONENTS

    SciTech Connect

    Abramczyk, G.; Nathan, S.; Loftin, B.; Bellamy, S.

    2011-06-06

    Radioactive material packages are withdrawn from use for various reasons; loss of mission, decertification, damage, replacement, etc. While the packages themselves may be decertified, various components may still be able to perform to their required standards and find useful service. The Packaging Technology and Pressurized Systems group of the Savannah River National Laboratory has been reducing the cost of producing new Type B Packagings by reclaiming, refurbishing, and returning to service the containment vessels from older decertified packagings. The program and its benefits are presented.

  18. Atmospheric radioactive isotopes at orbital altitudes.

    PubMed

    Gregory, J C

    1996-11-01

    The radioactive isotope 7Be was discovered on the forward-facing side of the LDEF satellite in amounts far exceeding that expected from direct cosmic ray activation of the spacecraft material. This prompted an examination of the production of cosmogenic isotopes in the atmosphere and of the processes by which they may be transported to orbital altitudes and adsorbed by a spacecraft. 7Be is only one of several atmospheric cosmogenic isotopes that might be detectable at orbital altitudes and that might prove to be as useful as tracers of atmospheric circulation processes in the mesosphere and thermosphere as they have been in the lower layers of the atmosphere. PMID:11540517

  19. Ideas and perspectives: truffles not radioactive

    NASA Astrophysics Data System (ADS)

    Büntgen, U.; Jäggi, M.; Stobbe, U.; Tegel, W.; Sproll, L.; Eikenberg, J.; Egli, S.

    2015-11-01

    Although ranging among the most expensive gourmet foods, it remains unclear if Burgundy truffles (Tuber aestivum) accumulate radioactivity at a harmful level comparable to other fungi. Here, we measure the 137Cs in 82 T. aestivum fruitbodies from Switzerland, Germany, France, Italy and Hungary. All specimens reveal insignificant radiocaesium concentrations, thus providing an all clear for truffle hunters and cultivators in Europe as well as dealers and customers from around the world. Our results are particularly relevant in the light of recent cultivation efforts and the fact that forest ecosystems are still highly contaminated with 137Cs, for which mushrooms are the main pathways to human diets.

  20. Particle beam generator using a radioactive source

    DOEpatents

    Underwood, David G. (Naperville, IL)

    1993-01-01

    The apparatus of the present invention selects from particles emitted by a radioactive source those particles having momentum within a desired range and focuses the selected particles in a beam having at least one narrow cross-dimension, and at the same time attenuates potentially disruptive gamma rays and low energy particles. Two major components of the present invention are an achromatic bending and focusing system, which includes sector magnets and quadrupole, and a quadrupole doublet final focus system. Permanent magnets utilized in the apparatus are constructed of a ceramic (ferrite) material which is inexpensive and easily machined.

  1. Corrosion resistant storage container for radioactive material

    DOEpatents

    Schweitzer, Donald G. (Bayport, NY); Davis, Mary S. (Wading River, NY)

    1990-01-01

    A corrosion resistant long-term storage container for isolating radioactive waste material in a repository. The container is formed of a plurality of sealed corrosion resistant canisters of different relative sizes, with the smaller canisters housed within the larger canisters, and with spacer means disposed between judxtaposed pairs of canisters to maintain a predetermined spacing between each of the canisters. The combination of the plural surfaces of the canisters and the associated spacer means is effective to make the container capable of resisting corrosion, and thereby of preventing waste material from leaking from the innermost canister into the ambient atmosphere.

  2. Introduction to naturally occurring radioactive material

    SciTech Connect

    Egidi, P.

    1997-08-01

    Naturally occurring radioactive material (NORM) is everywhere; we are exposed to it every day. It is found in our bodies, the food we eat, the places where we live and work, and in products we use. We are also bathed in a sea of natural radiation coming from the sun and deep space. Living systems have adapted to these levels of radiation and radioactivity. But some industrial practices involving natural resources concentrate these radionuclides to a degree that they may pose risk to humans and the environment if they are not controlled. Other activities, such as flying at high altitudes, expose us to elevated levels of NORM. This session will concentrate on diffuse sources of technologically-enhanced (TE) NORM, which are generally large-volume, low-activity waste streams produced by industries such as mineral mining, ore benefication, production of phosphate Fertilizers, water treatment and purification, and oil and gas production. The majority of radionuclides in TENORM are found in the uranium and thorium decay chains. Radium and its subsequent decay products (radon) are the principal radionuclides used in characterizing the redistribution of TENORM in the environment by human activity. We will briefly review other radionuclides occurring in nature (potassium and rubidium) that contribute primarily to background doses. TENORM is found in many waste streams; for example, scrap metal, sludges, slags, fluids, and is being discovered in industries traditionally not thought of as affected by radionuclide contamination. Not only the forms and volumes, but the levels of radioactivity in TENORM vary. Current discussions about the validity of the linear no dose threshold theory are central to the TENORM issue. TENORM is not regulated by the Atomic Energy Act or other Federal regulations. Control and regulation of TENORM is not consistent from industry to industry nor from state to state. Proposed regulations are moving from concentration-based standards to dose-based standards. So when is TENORM a problem? Where is it a problem? That depends on when, where, and whom you talk to! We will start by reviewing background radioactivity, then we will proceed to the geology, mobility, and variability of these radionuclides. We will then review some of the industrial sectors affected by TENORM, followed by a brief discussion on regulatory aspects of the issue.

  3. Radioactive waste disposal via electric propulsion

    NASA Technical Reports Server (NTRS)

    Burns, R. E.

    1975-01-01

    It is shown that space transportation is a feasible method of removal of radioactive wastes from the biosphere. The high decay heat of the isotopes powers a thermionic generator which provides electrical power for ion thrust engines. The massive shields (used to protect ground and flight personnel) are removed in orbit for subsequent reuse; the metallic fuel provides a shield for the avionics that guides the orbital stage to solar system escape. Performance calculations indicate that 4000 kg. of actinides may be removed per Shuttle flight. Subsidiary problems - such as cooling during ascent - are discussed.

  4. Corrosion resistant storage container for radioactive material

    DOEpatents

    Schweitzer, D.G.; Davis, M.S.

    1984-08-30

    A corrosion resistant long-term storage container for isolating high-level radioactive waste material in a repository is claimed. The container is formed of a plurality of sealed corrosion resistant canisters of different relative sizes, with the smaller canisters housed within the larger canisters, and with spacer means disposed between juxtaposed pairs of canisters to maintain a predetermined spacing between each of the canisters. The combination of the plural surfaces of the canisters and the associated spacer means is effective to make the container capable of resisting corrosion, and thereby of preventing waste material from leaking from the innermost canister into the ambient atmosphere.

  5. Astrophysics experiments with radioactive beams at ATLAS

    SciTech Connect

    Back, B. B.; Clark, J. A.; Pardo, R. C.; Rehm, K. E. Savard, G.

    2014-04-15

    Reactions involving short-lived nuclei play an important role in nuclear astrophysics, especially in explosive scenarios which occur in novae, supernovae or X-ray bursts. This article describes the nuclear astrophysics program with radioactive ion beams at the ATLAS accelerator at Argonne National Laboratory. The CARIBU facility as well as recent improvements for the in-flight technique are discussed. New detectors which are important for studies of the rapid proton or the rapid neutron-capture processes are described. At the end we briefly mention plans for future upgrades to enhance the intensity, purity and the range of in-flight and CARIBU beams.

  6. On the escaping radioactivity from coal power plants (CPP).

    PubMed

    Papastefanou, C; Charalambous, S

    1984-02-01

    The escaping radioactivity from Greek coal power plants (CPP) was studied. For the case studied the radioactivity is due to the uranium series. The major part (99%) escapes as very fine particles, while the rest is fly ash. The total escaping 226Ra activity is of the order of 40 Ci/yr. The particulate dispersion of fly ash in sites around the stacks of CPP is described. The hazards from the escaping radioactivity are evaluated. PMID:6693260

  7. "Radio-Active" Learning: Visual Representation of Radioactive Decay Using Dice

    ERIC Educational Resources Information Center

    Klein, Lynda; Kagan, David

    2010-01-01

    The idea of using a dice game to simulate radioactive decay is not new. However, modern pedagogy encourages, if not requires, us to provide multiple representations and visualizations for our students. The advantage of interactive engagement methods also has been made clear. Here we describe a highly visual and interactive use of dice to develop…

  8. Karlsruhe Database for Radioactive Wastes (KADABRA) - Accounting and Management System for Radioactive Waste Treatment - 12275

    SciTech Connect

    Himmerkus, Felix; Rittmeyer, Cornelia

    2012-07-01

    The data management system KADABRA was designed according to the purposes of the Cen-tral Decontamination Department (HDB) of the Wiederaufarbeitungsanlage Karlsruhe Rueckbau- und Entsorgungs-GmbH (WAK GmbH), which is specialized in the treatment and conditioning of radioactive waste. The layout considers the major treatment processes of the HDB as well as regulatory and legal requirements. KADABRA is designed as an SAG ADABAS application on IBM system Z mainframe. The main function of the system is the data management of all processes related to treatment, transfer and storage of radioactive material within HDB. KADABRA records the relevant data concerning radioactive residues, interim products and waste products as well as the production parameters relevant for final disposal. Analytical data from the laboratory and non destructive assay systems, that describe the chemical and radiological properties of residues, production batches, interim products as well as final waste products, can be linked to the respective dataset for documentation and declaration. The system enables the operator to trace the radioactive material through processing and storage. Information on the actual sta-tus of the material as well as radiological data and storage position can be gained immediately on request. A variety of programs accessed to the database allow the generation of individual reports on periodic or special request. KADABRA offers a high security standard and is constantly adapted to the recent requirements of the organization. (authors)

  9. Titanate-based adsorbents for radioactive ions entrapment from water.

    PubMed

    Yang, Dongjiang; Liu, Hongwei; Zheng, Zhanfeng; Sarina, Sarina; Zhu, Huaiyong

    2013-03-21

    This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process. PMID:23412572

  10. Titanate-based adsorbents for radioactive ions entrapment from water

    NASA Astrophysics Data System (ADS)

    Yang, Dongjiang; Liu, Hongwei; Zheng, Zhanfeng; Sarina, Sarina; Zhu, Huaiyong

    2013-02-01

    This feature article reviews some titanate-based adsorbents for the removal of radioactive wastes (cations and anions) from water. At the beginning, we discuss the development of the conventional ion-exchangeable titanate powders for the entrapment of radioactive cations, such as crystalline silicotitanate (CST), monosodium titanate (MST), peroxotitanate (PT). Then, we specially emphasize the recent progress in the uptake of radioactive ions by one-dimensional (1D) sodium titanate nanofibers and nanotubes, which includes the synthesis and phase transformation of the 1D nanomaterials, adsorption ability (capacity, selectivity, kinetics, etc.) of radioactive cations and anions, and the structural evolution during the adsorption process.

  11. [Processing of liquid radioactive waste by RADON Industrial Research Association].

    PubMed

    Panteleev, V I; Dmitriev, S A; Sobolev, I A; Karlin, Iu V; Demkin, V I; Adamovich, D V; Slastennikov, Iu T; Il'in, V A

    2006-01-01

    The authors present experience accumulated by "RADON" Industrial Research Association in treating liquid radioactive waste. According to the presentation, activities of "R ADON" Industrial Research Association develop in three directions--evolving technical means to purify radioactive waters in "RADON" Industrial Research Association, advancing mobile plants to purify radioactive waters in other institutions, elaborating new technologies for liquid radioactive waste purifications within numerous national and international projects and agreements with various organizations (including those associated with nuclear power stations and nuclear submarines). PMID:16568842

  12. Robust technique using an imaging plate to detect environmental radioactivity.

    PubMed

    Isobe, Tomonori; Mori, Yutaro; Takada, Kenta; Sato, Eisuke; Sakurai, Hideyuki; Sakae, Takeji

    2013-04-01

    The Fukushima Daiichi Nuclear Power Plant was severely damaged by the Great East Japan Earthquake on 11 March 2011. Consequently, a large amount of radioactive material was accidentally released. Recently, the focus has been on quantification of environmental radioactive material. However, conventional techniques require complicated and expensive measurement equipment. In this research, the authors developed a simple method to detect environmental radioactive material with an imaging plate (IP). Two specific measurement subjects were targeted: measurements for the depth distribution of radioactive material in soil and surface contamination of a building roof. For the measurement of depth distribution of radioactive material in soil, the authors ascertained that the concentration of environmental radioactivity was highest at 5 cm below the surface, and it decreased with depth. For the measurement of surface contamination of the building roof, the authors created a contamination map of the building roof. The detector developed could contact the ground directly, and unlike other survey meters, it was not influenced by peripheral radioactivity. In this study, the authors verified the feasibility of measurement of environmental radioactivity with an IP. Although the measured values of the IP were relative, further work is planned to perform evaluations of absolute quantities of radioactive material. PMID:23439139

  13. Radioactive Ion Beam Production Capabilities At The Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Beene, J. R.; Dowling, D. T.; Gross, C. J.; Juras, R. C.; Liu, Y.; Meigs, M. J.; Mendez, A. J. II; Nazarewicz, W.; Sinclair, J. W.; Stracener, D. W.; Tatum, B. A.

    2011-06-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) is a national user facility for research with radioactive ion beams (RIBs) that has been in routine operation since 1996. It is located at Oak Ridge National Laboratory (ORNL) and operated by the ORNL Physics Division. The principal mission of the HRIBF is the production of high quality beams of shortlived radioactive isotopes to support research in nuclear structure physics and nuclear astrophysics. HRIBF is currently unique worldwide in its ability to provide neutron-rich fission fragment beams post-accelerated to energies above the Coulomb barrier for nuclear reactions. HRIBF produces RIBs by the isotope separator on-line (ISOL) technique using a particle accelerator system that consists of the Oak Ridge Isochronous Cyclotron (ORIC) driver accelerator, one of the two Injectors for Radioactive Ion Species (IRIS1 or IRIS2) production systems, and the 25-MV tandem electrostatic accelerator that is used for RIB post-acceleration. ORIC provides a light ion beam (proton, deuteron, or alpha) which is directed onto a thick target mounted in a target-ion source (TIS) assembly located on IRIS1 or IRIS2. Radioactive atoms that diffuse from the target material are ionized, accelerated, mass selected, and transported to the tandem accelerator where they are further accelerated to energies suitable for nuclear physics research. RIBs are transported through a beam line system to various experimental end stations including the Recoil Mass Spectrometer (RMS) for nuclear structure research, and the Daresbury Recoil Separator (DRS) for nuclear astrophysics research. HRIBF also includes two off-line ion source test facilities, one low-power on-line ISOL test facility (OLTF), and one high-power on-line ISOL test facility (HPTL). This paper provides an overview and status update of HRIBF, describes the recently completed $4.7M IRIS2 addition and incorporation of laser systems for beam production and purification, and discusses a proposed replacement of the ORIC driver accelerator.

  14. Fred Hoyle, primary nucleosynthesis and radioactivity

    NASA Astrophysics Data System (ADS)

    Clayton, Donald D.

    2008-10-01

    Primary nucleosynthesis is defined as that which occurs efficiently in stars born of only H and He. It is responsible not only for increasing the metallicity of the galaxy but also for the most abundant gamma-ray-line emitters. Astrophysicists have inappropriately cited early work in this regard. The heavily cited B2FH paper (Burbidge et al., 1957) did not effectively address primary nucleosynthesis whereas Hoyle (Hoyle, 1954) had done so quite thoroughly in his infrequently cited 1954 paper. Even B2FH with Hoyle as coauthor seems strangely to not have appreciated what Hoyle (Hoyle, 1954) had achieved. I speculate that Hoyle must not have thoroughly proofread the draft written in 1956 by E.M. and G.R. Burbidge. The clear roadmap of primary nucleosynthesis advanced in 1954 by Hoyle describes the synthesis yielding the most abundant of the radioactive isotopes for astronomy, although that aspect was unrealized at the time. Secondary nucleosynthesis has also produced many observable radioactive nuclei, including the first gamma-ray-line emitter to be discovered in the galaxy and several others within stardust grains. Primary gamma-ray emitters would have been even more detectable in the early galaxy, when the birth rate of massive stars was greater; but secondary emitters, such as 26Al, would have been produced with smaller yield then owing to smaller abundance of seed nuclei from which to create them.

  15. SNIa light curves and radioactive decay

    E-print Network

    E. Cappellaro; P. A. Mazzali; S. Benetti; I. J. Danziger; M. Turatto; M. Della Valle; F. Patat

    1997-07-02

    The absolute V light curves of 5 SNe Ia, selected to represent the known range of absolute luminosities at maximum for this class of objects, are presented. Comparison of the long term luminosity evolution shows that the differences seen at maximum persist, and actually increase with time, einforcing the notion that intrinsic differences do exist among SNe Ia. Since such differences are not accounted for in the standard progenitor scenario, it becomes important to derive constraints for the models directly from the observations. In order to investigate the influence of the two most important parameters, that is the masses of the synthesized radioactive material and of the ejecta, a simple MC light curve model was used to simulate the luminosity evolution from the explosion to very late epochs (~1000 days). It was found that the observations require a range of a factor 10 in the masses of the radioactive material synthesized in the explosion (Mni= 0.1-1.1 Msun,) and a factor 2 in the total mass of the ejecta (Mej = 0.7-1.4 Msun). Differences of a factor 2 in Mni seem to be present even among `normal' SNe Ia. Some evidence was also found that the deposition of the positrons from Co decay varies from object to object, and with time. In particular, the latest HST observations of SN 1992A seem to imply complete trapping of the positrons.

  16. 2p radioactivity studied by tracking technique

    NASA Astrophysics Data System (ADS)

    Mukha, Ivan

    2010-06-01

    The recent advance in experimental studies of short-lived exotic nuclei beyond the proton drip line is presented. In particular, in-flight decays of proton-unbound nuclei with picosecond lifetimes can be probed by a novel technique which tracks all decay products precisely, and the decay vertices as well as the angular correlations of the fragments are deduced from the measured trajectories. The corresponding pioneering experiment which identified a previously-unknown isotope 19Mg and its two-proton (2p) radioactivity as well as studied the reference 2p decay of the known isotope 16Ne is described. Systematic studies of other 2p precursors beyond the proton drip line are foreseen with this powerful technique whose sensitivity is larger by factor of 30 in comparison with a conventional invariant-mass method. The 2p radioactivity candidates 30Ar, 34Ca and 26S are discussed. Information about the respective one-proton unbound nuclei can be obtained with this technique by evaluating proton-heavy-fragment correlations. Systematic studies of nuclei beyond the proton drip line, e.g., the well-known proton resonances above the ``waiting points'' in the astrophysical rp-process, 69Br and 73Br are feasible.

  17. Radioactive equilibrium in ancient marine sediments

    USGS Publications Warehouse

    Breger, I.A.

    1955-01-01

    Radioactive equilibrium in eight marine sedimentary formations has been studied by means of direct determinations of uranium, radium and thorium. Alpha-particle counting has also been carried out in order to cross-calibrate thick-source counting techniques. The maximum deviation from radioactive equilibrium that has been noted is 11 per cent-indicating that there is probably equilibrium in all the formations analyzed. Thick-source alpha-particle counting by means of a proportional counter or an ionization chamber leads to high results when the samples contain less than about 10 p.p.m. of uranium. For samples having a higher content of uranium the results are in excellent agreement with each other and with those obtained by direct analytical techniques. The thorium contents that have been obtained correspond well to the average values reported in the literature. The uranium content of marine sediments may be appreciably higher than the average values that have been reported for sedimentary rocks. Data show that there is up to fourteen times the percentage of uranium as of thorium in the formations studied and that the percentage of thorium never exceeds that of uranium. While the proximity of a depositional environment to a land mass may influence the concentration of uranium in a marine sediment, this is not true with thorium. ?? 1955.

  18. The radioactivity content of United Kingdom coal.

    PubMed

    Salmon, L; Toureau, A E; Lally, A E

    1984-05-01

    Twenty samples of coal representing each of the seven major regions of the National Coal Board have been analysed for their natural radioactivity content. A variety of methods have been used to verify the results, but the major technique used was radiation spectrometry of 3 kg samples. The results indicate a mean value for uranium and radium activity in British coals of 14.5 Bq/kg, for thorium 12.5 Bq/kg and for potassium 150 Bq/kg. These are significantly lower levels of actinides than have been previously reported and represent only two thirds of those previously used as source terms for assessment of the radiological impact of fossil fuel burning in the U.K.. The content of potassium in U.K. coal is twice the accepted global mean but the radiological significance of this element is negligible. A subsidiary finding is that uranium and its daughter radium are in secular radioactive equilibrium in coal within the experimental error of the analysis. PMID:6729445

  19. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect

    NA

    2004-11-22

    The purpose of this study is to evaluate dissolved concentration limits (also referred to as solubility limits) of elements with radioactive isotopes under probable repository conditions, based on geochemical modeling calculations using geochemical modeling tools, thermodynamic databases, field measurements, and laboratory experiments. The scope of this modeling activity is to predict dissolved concentrations or solubility limits for 14 elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) important to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are in the form of tabulated functions with pH and log (line integral) CO{sub 2} as independent variables, plus one or more uncertainty terms. The solubility limits for the remaining elements are either in the form of distributions or single values. The output data from this report are fundamental inputs for Total System Performance Assessment for the License Application (TSPA-LA) to determine the estimated release of these elements from waste packages and the engineered barrier system. Consistent modeling approaches and environmental conditions were used to develop solubility models for all of the actinides. These models cover broad ranges of environmental conditions so that they are applicable to both waste packages and the invert. Uncertainties from thermodynamic data, water chemistry, temperature variation, and activity coefficients have been quantified or otherwise addressed.

  20. Radioactivities induced in some LDEF samples

    NASA Technical Reports Server (NTRS)

    Reedy, Robert C.; Moss, Calvin E.; Bobias, S. George; Masarik, Jozef

    1993-01-01

    Radioactivities induced in several Long Duration Exposure Facilities (LDEF) samples were measured by low-level counting at Los Alamos and elsewhere. These radionuclides have activities similar to those observed in meteorites and lunar samples. Some trends were observed in these measurements in terms of profiles in trunnion layers and as a function of radionuclide half-life. Several existing computer codes were used to model the production by the protons trapped in the Earth's radiation belts and by the galactic cosmic rays of some of these radionuclides, Mn-54 and Co-57 in steel, Sc-46 in titanium, and Na-22 in alloys of titanium and aluminum. Production rates were also calculated for radionuclides possibly implanted in LDEF, Be-7, Be-10, and C-14. Enhanced concentrations of induced isotopes in the surfaces of trunnion sections relative to their concentrations in the center are caused by the lower-energy protons in the trapped radiation. Secondary neutrons made by high-energy trapped protons and by galactic cosmic rays produce much of the observed radioactivities, especially deep in an object. Comparisons of the observed to calculated activities of several radionuclides with different half-lives indicate that the flux of trapped protons at LDEF decreased significantly at the end of the mission.

  1. Folding model analysis of alpha radioactivity

    E-print Network

    D. N. Basu

    2003-07-29

    Radioactive decay of nuclei via emission of $\\alpha$ particles has been studied theoretically in the framework of a superasymmetric fission model using the double folding (DF) procedure for obtaining the $\\alpha$-nucleus interaction potential. The DF nuclear potential has been obtained by folding in the density distribution functions of the $\\alpha$ nucleus and the daughter nucleus with a realistic effective interaction. The M3Y effective interaction has been used for calculating the nuclear interaction potential which has been supplemented by a zero-range pseudo-potential for exchange along with the density dependence. The nuclear microscopic $\\alpha$-nucleus potential thus obtained has been used along with the Coulomb interaction potential to calculate the action integral within the WKB approximation. This subsequently yields microscopic calculations for the half lives of $\\alpha$ decays of nuclei. The density dependence and the exchange effects have not been found to be very significant. These calculations provide reasonable estimates for the lifetimes of $\\alpha$ radioactivity of nuclei.

  2. 2p radioactivity studied by tracking technique

    SciTech Connect

    Mukha, Ivan

    2010-06-01

    The recent advance in experimental studies of short-lived exotic nuclei beyond the proton drip line is presented. In particular, in-flight decays of proton-unbound nuclei with picosecond lifetimes can be probed by a novel technique which tracks all decay products precisely, and the decay vertices as well as the angular correlations of the fragments are deduced from the measured trajectories. The corresponding pioneering experiment which identified a previously-unknown isotope {sup 19}Mg and its two-proton (2p) radioactivity as well as studied the reference 2p decay of the known isotope {sup 16}Ne is described. Systematic studies of other 2p precursors beyond the proton drip line are foreseen with this powerful technique whose sensitivity is larger by factor of 30 in comparison with a conventional invariant-mass method. The 2p radioactivity candidates {sup 30}Ar, {sup 34}Ca and {sup 26}S are discussed. Information about the respective one-proton unbound nuclei can be obtained with this technique by evaluating proton-heavy-fragment correlations. Systematic studies of nuclei beyond the proton drip line, e.g., the well-known proton resonances above the 'waiting points' in the astrophysical rp-process, {sup 69}Br and {sup 73}Br are feasible.

  3. Crystallization of sodium nitrate from radioactive waste

    SciTech Connect

    Krapukhin, V.B.; Krasavina, E.P. Pikaev, A.K.

    1997-07-01

    From the 1940s to the 1980s, the Institute of Physical Chemistry of the Russian Academy of Sciences (IPC/RAS) conducted research and development on processes to separate acetate and nitrate salts and acetic acid from radioactive wastes by crystallization. The research objective was to decrease waste volumes and produce the separated decontaminated materials for recycle. This report presents an account of the IPC/RAS experience in this field. Details on operating conditions, waste and product compositions, decontamination factors, and process equipment are described. The research and development was generally related to the management of intermediate-level radioactive wastes. The waste solutions resulted from recovery and processing of uranium, plutonium, and other products from irradiated nuclear fuel, neutralization of nuclear process solutions after extractant recovery, regeneration of process nitric acid, equipment decontamination, and other radiochemical processes. Waste components include nitric acid, metal nitrate and acetate salts, organic impurities, and surfactants. Waste management operations generally consist of two stages: volume reduction and processing of the concentrates for storage, solidification, and disposal. Filtration, coprecipitation, coagulation, evaporation, and sorption were used to reduce waste volume. 28 figs., 40 tabs.

  4. The political science of radioactive waste disposal

    SciTech Connect

    Jacobi, L.R. Jr.

    1996-06-01

    This paper was first presented at the annual meeting of the HPS in New Orleans in 1984. Twelve years later, the basic lessons learned are still found to be valid. In 1984, the following things were found to be true: A government agency is preferred by the public over a private company to manage radioactive waste. Semantics are important--How you say it is important, but how it is heard is more important. Public information and public relations are very important, but they are the last thing of concern to a scientist. Political constituency is important. Don`t overlook the need for someone to be on your side. Don`t forget that the media is part of the political process-they can make you or break you. Peer technical review is important, but so is citizen review. Sociology is an important issue that scientists and technical people often overlook. In summary, despite the political nature of radioactive waste disposal, it is as true today as it was in 1984 that technical facts must be used to reach sound technical conclusions. Only then, separately and openly, should political factors be considered. So, what can be said today that wasn`t said in 1984? Nothing. {open_quotes}It`s deja vu all over again.{close_quotes}

  5. Radioactivity in municipal sewage and sludge.

    PubMed Central

    Martin, J E; Fenner, F D

    1997-01-01

    OBJECTIVE: To determine the environmental consequences of discharges of radioactivity from a large medical research facility into municipal sewage, specifically 131I activity in sewage sludge, and the radiation exposures to workers and the public when sludges are incinerated. METHODS: The authors measured radioactivity levels in the sludge at the Ann Arbor, Michigan, Waste Water Treatment Plant following radioiodine treatments of two patients at the University of Michigan hospital complex and performed a series of calculations to estimate potential radiation doses due to releases of 131I from incineration of sewage sludge. RESULTS: Approximately 1.1% of the radioactive 131I administered therapeutically to patients was measured in the primary sludge. Radiation doses from incineration of sludge were calculated to be 0.048 millirem (mrem) for a worker during a period in which the incinerator filtration system failed, a condition that could be considered to represent maximum exposure conditions, for two nine-hour days. Calculated results for a more typically exposed worker (with the filtration system in operation and a 22-week period of incineration) yielded a committed effective dose equivalent of 0.066 mrem. If a worker were exposed to both conditions during the period of incineration, the dose was calculated to be 0.11 mrem. For a member of the public, the committed effective dose equivalent was calculated as 0.003 mrem for a 22-week incineration period. Exposures to both workers and the public were a very small fraction of a typical annual dose (about 100 mrem excluding radon, or 300 mrem with radon) due to natural background radiation. Transport time to the treatment plant for radioiodine was found to be much longer than that of a normal sewage, possibly due to absorption of iodine by organic material in the sewer lines. The residence time of radioiodine in the sewer also appears to be longer than expected. CONCLUSION: 131I in land-applied sludge presents few health concerns because sufficient decay occurs before it can reach the public however, incineration, which is done in winter months, directly releases the 131I from sewage sludge to the atmosphere, and even though exposures to both workers and the public were found to be considerably lower than 1% of natural background, incineration of sludge in a pathway for public exposure. Although 131I was readily measurable in sewage sludge, only about 1% of the radioione administered to patients was found in the sludge. The fate of the remaining radioactivity has not been established; some may be in secondary and tertiary residuals, but it is quite likely that most passed through the plant and was discharged in dilute concentrations in plant emissions. The behavior of radioiodine and other radioactive materials released into municipal seweage systems, such as those from large medical facilities, is not yet well understood. PMID:9258296

  6. RADIOACTIVE CHEMICAL ELEMENTS IN THE ATOMIC TABLE.

    SciTech Connect

    HOLDEN, N.E.

    2005-08-13

    In the 1949 Report of the Atomic Weights Commission, a series of new elements were added to the Atomic Weights Table. Since these elements had been produced in the laboratory and were not discovered in nature, the atomic weight value of these artificial products would depend upon the production method. Since atomic weight is a property of an element as it occurs in nature, it would be incorrect to assign an atomic weight value to that element. As a result of that discussion, the Commission decided to provide only the mass number of the most stable (longest-lived) known isotope as the number to be associated with these entries in the Atomic Weights Table. As a function of time, the mass number associated with various elements has changed as longer-lived isotopes of a particular elements has been found in nature, or as improved half-life values of an element's isotopes might cause a shift in the longest-lived isotope from one mass number to another. In the 1957 Report of the Atomic Weights Commission, it was decided to discontinue the listing of the mass number in the Atomic Weights Table on the grounds that the kind of information supplied by the mass number is inconsistent with the primary purpose of the Table, i.e., to provide accurate values of ''these constants'' for use in chemical calculations. In addition to the Table of Atomic Weights, the Commission included an auxiliary Table of Radioactive Elements for the first time, where the entry would be the isotope of that element which was most stable, i.e., it had the longest known half-life. In their 1973 report, the Commission noted that the users of the Atomic Weights Table were dissatisfied with the omission of values in the Table for some elements and it was decided to reintroduce the mass number for elements. In their 1983 report, the Commission decided that radioactive elements were considered to lack a characteristic terrestrial isotopic composition, from which an atomic weight value could be calculated to five or more figure accuracy, without prior knowledge of the sample. These elements were again listed in the table with no further information, is., no mass number or atomic weight value. For the elements, which have no stable or long-lived isotopes, the data on radioactive half-lives and relative atomic masses for the nuclides of interest have been evaluated. The values of the half-lives their uncertainties are listed. The uncertainties are given in the last digit quoted of the half-life vale and shown in parentheses. The criteria for consideration of entries in this Table continue to be the same as it has been for over fifty years. It is the same criteria, which are used for all data that are evaluated for inclusion in the Atomic Weight's Table. If a report of data is published in a peer-reviewed journal, that data is evaluated and considered for inclusion in the appropriate table of the biennial report of the Atomic Weights Commission. As better data might become available in the future, the information that is contained in either of the tables may be modified. The information contained in the Table of Radioactive Elements should enable the user to calculate the atomic weight for any sample of radioactive material, which might have a variety of isotopic compositions. The atomic mass values have been taken from the 2003 Atomic Mass Table. Most of these half-lives have already been documented in various sources.

  7. PROCEDURE FOR STORAGE OF RADIOACTIVE MATERIALS All radioactive materials must be stored in a manner that ensures that the material cannot be

    E-print Network

    Bearhop, Stuart

    PROCEDURE FOR STORAGE OF RADIOACTIVE MATERIALS All radioactive materials must be stored in a manner that ensures that the material cannot be accessed by unauthorised persons. This includes radioactive materials in the form of waste. Subject to the nature of the medium in which the radioactive isotope is incorporated

  8. 13.17 Radioactive or Radiation-Producing Materials or Equipment Page 1 of 2 Radioactive or Radiation-Producing Materials or Equipment

    E-print Network

    Hung, I-Kuai

    13.17 Radioactive or Radiation-Producing Materials or Equipment Page 1 of 2 Radioactive, and procedures involving the use of radioactive materials or radiation producing equipment are performed university employees and students who receive, possess, use, transfer, or acquire any radioactive material

  9. Radioactive demonstration of the late wash'' Precipitate Hydrolysis Process

    SciTech Connect

    Bibler, N.E.; Ferrara, D.M.; Ha, B.C.

    1992-06-30

    This report presents results of the radioactive demonstration of the DWPF Precipitate Hydrolysis Process as it would occur in the late wash'' flowsheet in the absence of hydroxylamine nitrate. Radioactive precipitate containing Cs-137 from the April, 1983, in-tank precipitation demonstration in Tank 48 was used for these tests.

  10. Radioactive demonstration of the ``late wash`` Precipitate Hydrolysis Process

    SciTech Connect

    Bibler, N.E.; Ferrara, D.M.; Ha, B.C.

    1992-06-30

    This report presents results of the radioactive demonstration of the DWPF Precipitate Hydrolysis Process as it would occur in the ``late wash`` flowsheet in the absence of hydroxylamine nitrate. Radioactive precipitate containing Cs-137 from the April, 1983, in-tank precipitation demonstration in Tank 48 was used for these tests.

  11. Transporting Radioactive Waste: An Engineering Activity. Grades 5-12.

    ERIC Educational Resources Information Center

    HAZWRAP, The Hazardous Waste Remedial Actions Program.

    This brochure contains an engineering activity for upper elementary, middle school, and high school students that examines the transportation of radioactive waste. The activity is designed to inform students about the existence of radioactive waste and its transportation to disposal sites. Students experiment with methods to contain the waste and…

  12. Detecting and Locating Radioactive Signals with Wireless Sensor Networks

    E-print Network

    Zhang, Tonglin

    Detecting and Locating Radioactive Signals with Wireless Sensor Networks Tonglin Zhang Department-765-4940558 AbstractMethods of detecting and locating nuclear radioac- tive targets via wireless sensor networks (WSN model, radia- tion and radioactive isotopes, wireless sensor network. I. INTRODUCTION Currently, using

  13. Transporting radioactive materials: Q & A to your questions

    SciTech Connect

    Not Available

    1993-04-01

    Over 2 million packages of radioactive materials are shipped each year in the United States. These shipments are carried by trucks, trains, ships, and airplanes every day just like other commodities. Compliance with Federal regulations ensures that radioactive materials are transported safely. Proper packaging is the key to safe shipment. Package designs for radioactive materials must protect the public and the environment even in case of an accident. As the level of radioactivity increases, packaging design requirements become more stringent. Radioactive materials have been shipped in this country for more than 40 years. As with other commodities, vehicles carrying these materials have been involved in accidents. However, no deaths or serious injuries have resulted from exposure to the radioactive contents of these shipments. People are concerned about how radioactive shipments might affect them and the environment. This booklet briefly answers some of the commonly asked questions about the transport of radioactive materials. More detailed information is available from the sources listed at the end of this booklet.

  14. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 1 2011-01-01 2011-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY...RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is...

  15. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 1 2014-01-01 2014-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY...RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is...

  16. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 1 2010-01-01 2010-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY...RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is...

  17. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 1 2013-01-01 2013-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY...RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is...

  18. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 1 2012-01-01 2012-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY...RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is...

  19. [Concentrations of radioactive cesium in different cuts of beef].

    PubMed

    Nabeshi, Hiromi; Kikuchi, Hiroyuki; Tsutsumi, Tomoaki; Hachisuka, Akiko; Matsuda, Rieko

    2013-01-01

    After the Fukushima No. 1 Nuclear Power Plant accident, high levels of radioactive cesium were detected in beef. Many prefectural governments decided to conduct blanket tests on meat from local beef cattle to prevent distribution of beef contaminated with radioactive cesium exceeding the provisional regulation value. In some cases, different concentrations of radioactive cesium were found in different cuts of beef from the same cows. These results raised questions about the reliability of the test results. Here, we investigated the reason for the differences in radioactive cesium concentration in different cuts of beef from the same cows. The concentrations of radioactive cesium in five different parts cuts of beef from three cows were negatively correlated with fat content, suggesting that the difference in radioactive cesium concentration is due to differences in fat content in the meat. In addition, our results showed that the concentration of radioactive cesium in muscle was more than 7-fold higher than that in fat in the same cow. These results suggested that it is necessary to use muscle for testing of radioactive cesium in cows. PMID:24389473

  20. The Study of Radioactive Drugs in Human Subjects

    Cancer.gov

    Basic research for the purpose of advancing scientific knowledge The research is intended to obtain basic information regarding the metabolism of radioactive drugs including kinetics, distribution, dosimetry, and localization OR Obtain basic information regarding human physiology, pathophysiology, and biochemistry of radioactive drugs.

  1. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... dispose of radioactive waste (as defined in 10 CFR part 20, appendix B, table II, but not including high level and transuranic waste and spent nuclear fuel covered by 40 CFR part 191) shall comply with the... the Navajo, Ute Mountain Ute, and All Other New Mexico Tribes § 147.3005 Radioactive waste...

  2. Naturally Occurring Radioactive Materials in Cargo at US Borders

    SciTech Connect

    Kouzes, Richard T.; Ely, James H.; Evans, John C.; Hensley, Walter K.; Lepel, Elwood A.; McDonald, Joseph C.; Schweppe, John E.; Siciliano, Edward R.; Strom, Daniel J.; Woodring, Mitchell L.

    2006-01-01

    In the U.S. and other countries, large numbers of vehicles pass through border crossings each day. The illicit movement of radioactive sources is a concern that has resulted in the installation of radiation detection and identification instruments at border crossing points. This activity is judged to be necessary because of the possibility of an act of terrorism involving a radioactive source that may include any number of dangerous radionuclides. The problem of detecting, identifying, and interdicting illicit radioactive sources is complicated by the fact that many materials present in cargo are somewhat radioactive. Some cargo contains naturally occurring radioactive material or technologically-enhanced naturally occurring radioactive material that may trigger radiation portal monitor alarms. Man-made radioactive sources, especially medical isotopes, are also frequently observed and produce alarms. Such nuisance alarms can be an operational limiting factor for screening of cargo at border crossings. Information about the nature of the radioactive materials in cargo that can interfere with the detection of radionuclides of concern is necessary. This paper provides such information for North American cargo, but the information may also be of use to border control officials in other countries. (PIET-43741-TM-361)

  3. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ... dispose of radioactive waste (as defined in 10 CFR part 20, appendix B, table II, but not including high level and transuranic waste and spent nuclear fuel covered by 40 CFR part 191) shall comply with the... 40 Protection of Environment 24 2012-07-01 2012-07-01 false Radioactive waste injection wells....

  4. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ... dispose of radioactive waste (as defined in 10 CFR part 20, appendix B, table II, but not including high level and transuranic waste and spent nuclear fuel covered by 40 CFR part 191) shall comply with the... 40 Protection of Environment 24 2013-07-01 2013-07-01 false Radioactive waste injection wells....

  5. 40 CFR 147.3005 - Radioactive waste injection wells.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ... dispose of radioactive waste (as defined in 10 CFR part 20, appendix B, table II, but not including high level and transuranic waste and spent nuclear fuel covered by 40 CFR part 191) shall comply with the... 40 Protection of Environment 23 2014-07-01 2014-07-01 false Radioactive waste injection wells....

  6. 10 CFR 76.81 - Authorized use of radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 2 2010-01-01 2010-01-01 false Authorized use of radioactive material. 76.81 Section 76.81 Energy NUCLEAR REGULATORY COMMISSION (CONTINUED) CERTIFICATION OF GASEOUS DIFFUSION PLANTS Safety § 76.81 Authorized use of radioactive material. Unless otherwise authorized by law, the...

  7. An Excel[TM] Model of a Radioactive Series

    ERIC Educational Resources Information Center

    Andrews, D. G. H.

    2009-01-01

    A computer model of the decay of a radioactive series, written in Visual Basic in Excel[TM], is presented. The model is based on the random selection of cells in an array. The results compare well with the theoretical equations. The model is a useful tool in teaching this aspect of radioactivity. (Contains 4 figures.)

  8. The Identification of Factors Influencing College Students' Attitudes toward Radioactivity.

    ERIC Educational Resources Information Center

    Crater, Harold L., Jr.

    The two basic questions considered in this study were: (1) What attitudes do college students hold toward radioactivity? and (2) What are some characteristics associated with the college students who hold the more favorable attitudes toward radioactivity? The sample studied included 1,205 mostly undergraduate students at the University of Texas at…

  9. High-Level Radioactive Waste: Safe Storage and Ultimate Disposal.

    ERIC Educational Resources Information Center

    Dukert, Joseph M.

    Described are problems and techniques for safe disposal of radioactive waste. Degrees of radioactivity, temporary storage, and long-term permanent storage are discussed. Included are diagrams of estimated waste volumes to the year 2000 and of an artist's conception of a permanent underground disposal facility. (SL)

  10. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ... 10 Energy 1 2014-01-01 2014-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is expressed in the special unit...

  11. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ... 10 Energy 1 2011-01-01 2011-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is expressed in the special unit...

  12. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ... 10 Energy 1 2013-01-01 2013-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is expressed in the special unit...

  13. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is expressed in the special unit...

  14. 10 CFR 20.1005 - Units of radioactivity.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ... 10 Energy 1 2012-01-01 2012-01-01 false Units of radioactivity. 20.1005 Section 20.1005 Energy NUCLEAR REGULATORY COMMISSION STANDARDS FOR PROTECTION AGAINST RADIATION General Provisions § 20.1005 Units of radioactivity. For the purposes of this part, activity is expressed in the special unit...

  15. 10 CFR 39.69 - Radioactive contamination control.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ... 10 Energy 1 2010-01-01 2010-01-01 false Radioactive contamination control. 39.69 Section 39.69... Radiation Safety Requirements § 39.69 Radioactive contamination control. (a) If the licensee detects evidence that a sealed source has ruptured or licensed materials have caused contamination, the...

  16. Radiation Protection Guide For Medical Use of Radioactive Materials &

    E-print Network

    University radiation protection guides. #12;iii RADIOACTIVE MATERIAL SPILL RESPONSE INFORMATION In the event[Year] Radiation Protection Guide For Medical Use of Radioactive Materials & Radiation Producing) is responsible for implementing the University's radiation safety program as defined by its Radiation Safety

  17. Radioactive Effluents from Nuclear Power Plants Annual Report 2007

    SciTech Connect

    U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation

    2010-12-10

    This report describes radioactive effluents from commercial nuclear power plants (NPPs) in the United States. This information was reported by the licensees for radioactive discharges that occurred in 2007. The report provides information relevant to the potential impact of NPPs on the environment and on public health.

  18. Radioactive Effluents from Nuclear Power Plants Annual Report 2008

    SciTech Connect

    U.S. Nuclear Regulatory Commission, Office of Nuclear Reactor Regulation

    2010-12-10

    This report describes radioactive effluents from commercial nuclear power plants (NPPs) in the United States. This information was reported by the licensees for radioactive discharges that occurred in 2008. The report provides information relevant to the potential impact of NPPs on the environment and on public health.

  19. A model approach to radioactive waste disposal at Sellafield

    E-print Network

    Haszeldine, Stuart

    A model approach to radioactive waste disposal at Sellafield R. 5. Haszeldine* and C. Mc of the great environmentalproblems of our age is the safe disposal of radioactive waste for geological time periods. Britain is currently investigating a potential site for underground burial of waste, near

  20. Area 5 Radioactive Waste Management Site Safety Assessment Document

    SciTech Connect

    Horton, K.K.; Kendall, E.W.; Brown, J.J.

    1980-02-01

    The Area 5 Radioactive Waste Management Safety Assessment Document evaluates site characteristics, facilities and operating practices which contribute to the safe handling and storage/disposal of radioactive wastes at the Nevada Test Site. Physical geography, cultural factors, climate and meteorology, geology, hydrology (with emphasis on radionuclide migration), ecology, natural phenomena, and natural resources are discussed and determined to be suitable for effective containment of radionuclides. Also considered, as a separate section, are facilities and operating practices such as monitoring; storage/disposal criteria; site maintenance, equipment, and support; transportation and waste handling; and others which are adequate for the safe handling and storage/disposal of radioactive wastes. In conclusion, the Area 5 Radioactive Waste Management Site is suitable for radioactive waste handling and storage/disposal for a maximum of twenty more years at the present rate of utilization.

  1. Leachate tests with sewage sludge contaminated by radioactive cesium.

    PubMed

    Tsushima, Ikuo; Ogoshi, Masashi; Harada, Ichiro

    2013-01-01

    The sewer systems of eastern Japan have transported radioactive fallout from the Fukushima Dai-ichi nuclear power plant accident to wastewater treatment plants, where the radioisotopes have accumulated. To better understand the potential problems associated with the disposal of contaminated sewage sludge in landfills, leachate tests were conducted with radioactive incinerator ash, cement solidification incinerator ash, and dewatered sludge cake. Radioactivity was undetectable in the eluate from incinerator ash and dewatered sludge cake, but about 30% of the radioactivity initially in cement solidification incinerator ash appeared in the eluate during the leaching experiments. Moreover, modification of test conditions revealed that the presence of Ca(2+) ions and strong alkali in the water that contacted the incinerator ash enhanced leaching of cesium. Lastly, the capacity of pit soil to absorb radioactive cesium was estimated to be at least 3.0 Bq/g (dry). PMID:23947711

  2. Conversion of radioactive waste materials into solid form

    SciTech Connect

    Bustard, T.S.; Pohl, C.S.

    1980-10-28

    Radioactive waste materials are converted into solid form by mixing the radioactive waste with a novel polymeric formulation which, when solidified, forms a solid, substantially rigid matrix that contains and entraps the radioactive waste. The polymeric formulation comprises, in certain significant proportions by weight, urea-formaldehyde; methylated urea-formaldehyde; urea and a plasticizer. A defoaming agent may also be incorporated into the polymeric composition. In the practice of the invention, radioactive waste, in the form of a liquid or slurry, is mixed with the polymeric formulation, with this mixture then being treated with an acidic catalyzing agent, such as sulfuric acid. This mixture is then preferably passed to a disposable container so that, upon solidification, the radioactive waste, entrapped within the matrix formed by the polymeric formulation, may be safely and effectively stored or disposed of.

  3. 76 FR 53980 - Request for a License To Import Radioactive Waste

    Federal Register 2010, 2011, 2012, 2013, 2014

    2011-08-30

    ...Request for a License To Import Radioactive Waste Pursuant to 10 CFR 110.70...Hitachi Nuclear Energy, LLC. Radioactive waste Up to 210 Cobalt- Recycling...Cobalt-60 sources. or storage and radioactive Combined total...

  4. 49 CFR 173.424 - Excepted packages for radioactive instruments and articles.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...AND PACKAGINGS Class 7 (Radioactive) Materials § 173.424 Excepted packages for radioactive instruments and articles. A radioactive instrument or article...hazardous substance or hazardous waste, shipping papers and...

  5. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ... false Who cleans up radioactive and hazardous material... Hazardous and Nuclear Waste Transportation § 170.906 Who cleans up radioactive and hazardous material...responsible for cleanup of a radioactive or hazardous...

  6. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ... false Who cleans up radioactive and hazardous material... Hazardous and Nuclear Waste Transportation § 170.906 Who cleans up radioactive and hazardous material...responsible for cleanup of a radioactive or hazardous...

  7. 25 CFR 170.901 - What standards govern transportation of radioactive and hazardous materials?

    Code of Federal Regulations, 2012 CFR

    2012-04-01

    ...standards govern transportation of radioactive and hazardous materials...Provisions Hazardous and Nuclear Waste Transportation § 170.901...standards govern transportation of radioactive and hazardous materials...regulations for the shipment of radioactive and hazardous materials....

  8. 25 CFR 170.901 - What standards govern transportation of radioactive and hazardous materials?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ...standards govern transportation of radioactive and hazardous materials...Provisions Hazardous and Nuclear Waste Transportation § 170.901...standards govern transportation of radioactive and hazardous materials...regulations for the shipment of radioactive and hazardous materials....

  9. 49 CFR 173.421 - Excepted packages for limited quantities of Class 7 (radioactive) materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...substance or hazardous waste, shipping papers...nonfixed (removable) radioactive surface contamination...bears the marking “Radioactive”; (5) The package...quantity of Class 7 (radioactive) material that is a...substance or a hazardous waste, is not subject to...

  10. 25 CFR 170.901 - What standards govern transportation of radioactive and hazardous materials?

    Code of Federal Regulations, 2013 CFR

    2013-04-01

    ...standards govern transportation of radioactive and hazardous materials...Provisions Hazardous and Nuclear Waste Transportation § 170.901...standards govern transportation of radioactive and hazardous materials...regulations for the shipment of radioactive and hazardous materials....

  11. 49 CFR 173.421 - Excepted packages for limited quantities of Class 7 (radioactive) materials.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...AND PACKAGINGS Class 7 (Radioactive) Materials § 173.421...limited quantities of Class 7 (radioactive) materials. A Class 7 (radioactive) material with an activity...hazardous substance or hazardous waste, shipping papers, and...

  12. 49 CFR 173.422 - Additional requirements for excepted packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...PACKAGINGS Class 7 (Radioactive) Materials § 173...containing Class 7 (radioactive) materials. An excepted package of Class 7 (radioactive) material that is prepared...substance or a hazardous waste, the shipping...

  13. 49 CFR 173.421 - Excepted packages for limited quantities of Class 7 (radioactive) materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...substance or hazardous waste, shipping papers...nonfixed (removable) radioactive surface contamination...bears the marking “Radioactive”; (5) The package...quantity of Class 7 (radioactive) material that is a...substance or a hazardous waste, is not subject to...

  14. 49 CFR 173.424 - Excepted packages for radioactive instruments and articles.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...AND PACKAGINGS Class 7 (Radioactive) Materials § 173.424 Excepted packages for radioactive instruments and articles. A radioactive instrument or article...hazardous substance or hazardous waste, shipping papers and...

  15. 25 CFR 170.901 - What standards govern transportation of radioactive and hazardous materials?

    Code of Federal Regulations, 2014 CFR

    2014-04-01

    ...standards govern transportation of radioactive and hazardous materials...Provisions Hazardous and Nuclear Waste Transportation § 170.901...standards govern transportation of radioactive and hazardous materials...regulations for the shipment of radioactive and hazardous materials....

  16. 49 CFR 173.422 - Additional requirements for excepted packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...PACKAGINGS Class 7 (Radioactive) Materials § 173...containing Class 7 (radioactive) materials. An excepted package of Class 7 (radioactive) material that is prepared...substance or a hazardous waste, the shipping...

  17. 25 CFR 170.906 - Who cleans up radioactive and hazardous material spills?

    Code of Federal Regulations, 2011 CFR

    2011-04-01

    ... false Who cleans up radioactive and hazardous material... Hazardous and Nuclear Waste Transportation § 170.906 Who cleans up radioactive and hazardous material...responsible for cleanup of a radioactive or hazardous...

  18. 49 CFR 173.421 - Excepted packages for limited quantities of Class 7 (radioactive) materials.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...substance or hazardous waste, shipping papers...nonfixed (removable) radioactive surface contamination...bears the marking “Radioactive”; (5) The package...quantity of Class 7 (radioactive) material that is a...substance or a hazardous waste, is not subject to...

  19. 49 CFR 173.421 - Excepted packages for limited quantities of Class 7 (radioactive) materials.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...substance or hazardous waste, shipping papers...nonfixed (removable) radioactive surface contamination...bears the marking “Radioactive”; (5) The package...quantity of Class 7 (radioactive) material that is a...substance or a hazardous waste, is not subject to...

  20. 49 CFR 173.422 - Additional requirements for excepted packages containing Class 7 (radioactive) materials.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...PACKAGINGS Class 7 (Radioactive) Materials § 173...containing Class 7 (radioactive) materials. An excepted package of Class 7 (radioactive) material that is prepared...substance or a hazardous waste, the shipping...