Sample records for u-series radioactive disequilibria

  1. U-series Disequilibria in MORB From Transforms and Implications for Mantle Melting

    NASA Astrophysics Data System (ADS)

    Tepley, F. J.; Lundstrom, C. C.; Sims, K. W.

    2001-12-01

    Transform settings produce greater compositional diversity in erupted basalts than on-axis settings, most likely due to magmas being less subjected to crustal level mixing and fractionation processes. We report U-Th-Ra disequilibria measurements in MORB glasses from three different transform settings from the mid-ocean ridge system. Our goal is to relate the disequilibria to existing U-series data from adjacent ridge axes. We analyzed 25 samples ranging from primitive, depleted basalts to moderately enriched basalts from the Cox Transform, ( ~32° S latitude on the Mid-Atlantic Ridge), the Blanco Transform ( ~44° N latitude offsetting the Gorda and Juan de Fuca Ridges), and the Garrett Transform ( ~13° 30'S latitude on the East Pacific Rise) for Th isotopes by ion probe (WHOI), U and Th concentrations by ICP-MS (WHOI) and Ra by TIMS (UIUC). Samples from the Cox Transform contain 16-272 ppb U and 42-850 ppb Th equating to Th/U ratios that vary between 2.6 and 3.1. (230Th)/(232Th) range between 0.99 and 1.15. Samples have slight 230Th excesses ranging from 1-4%. Samples from the Blanco Transform have between 50-300 ppb U and 140-900 ppb Th with a restricted range in Th/U ( ~2.9). These samples have (230Th)/(232Th) ranging between 1.1-1.2 resulting in small 230Th excesses (6-12%). (226Ra)/(230Th) range from 1.0 to 1.3, most likely reflecting the effect of significant age since eruption. Samples from the Garrett Transform have 9-75 ppb U and 14-215 ppb Th and large variations in Th/U (1.5 to 2.9). (230Th)/(232Th) vary from 1.2 to 1.5 such that (230Th)/(238U) range from ~15% excess 230Th in high Th/U samples to 4 samples with 3-7% 238U excess at low Th/U. Garrett samples also have large 226Ra excesses, with (226Ra)/(230Th) varying between 1.3 and 4, including several samples between 3 and 4. The data from the Cox and Blanco Transforms do not form simple binary mixing relationships among the disequilibria as observed previously in the Siquieros Transform (Lundstrom et al., JGR 1999). Part of this reflects the relatively restricted range in Th/U of the samples and part may reflect significant age since eruption. Data from the Garrett Transform are consistent with previous observations with high 226Ra excesses observed in basalts having low to no excess 230Th. This observation is consistent with a reactive porous flow melting process in which large 226Ra excesses are generated and maintained to shallow depths (<30 km) in the melt column.

  2. TH isotope and U-series disequilibria in some alkali basalts

    NASA Astrophysics Data System (ADS)

    Williams, R. W.; Gill, J. B.

    1992-01-01

    The activities of 238U-series nuclides and 232Th have been measured by alpha spectrometry for nine alkali basalts from Heard island, Mt. Cameroon, Nyamuragira, and Nyiragongo. Large 226Ra enrichments are inferred to be absent from all, suggesting the absence of subsolidus fluids before magma genesis. Th isotope ratios are consistent with deep metasomatism forming carbonates beneath Nyiragongo, versus shallower metasomatism forming amphibole beneath Nyamuragira. In contrast, the Th/U ratio in the Nyamuragira source has increased with time, which is used to confirm that the Th/U ratio of the mantle is about 4.2.

  3. Source heterogeneity and melting conditions along the Southeast Indian Ridge: A U-series disequilibria perspective

    NASA Astrophysics Data System (ADS)

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

    2006-12-01

    Variations in axial depth and spreading rate along the global system of mid-ocean ridges may be controlled either by mantle temperature and upwelling (melting) rate, or by chemical composition (mantle heterogeneity) and associated melting conditions, but the relative importance of each is poorly understood. To examine this on a regional scale (102 to 103 km), we have measured U-Th isotopes on 16 basaltic glasses collected along the Southeast Indian Ridge (SEIR) from 90° E to 117° E. This section of ridge is characterized by nearly constant spreading rate (70-75 mm/yr) and 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 dataset of U-series measurements on MORB, axial depth does not negatively correlate with measured 230Th-excess along the SEIR. This suggests that, at a regional scale, depth and extent of melting in the Indian Ocean mantle is influenced both by variations in mantle temperature and mantle composition. The SEIR glasses analyzed in this study can be separated into 3 geographically distinct groups; a western group (WG, 90°E to 98°E, 5 samples), a middle group (MG, 100°E to 114°E, 9 samples), and an eastern group (EG, east of 114°E, 2 samples). Th and U concentrations range from 130-1158 ppb and 55-313 ppb, respectively, with measured Th/U = 2.35 to 3.78. All samples have 230Th- excesses, with (230Th/238U) ranging from 1.01 to 1.21. On a U-Th equiline diagram the geographic groups form 3 offset linear arrays, with the WG characterized by (230Th/232Th) = 1.42 to 1.24, the MG by (230Th/232Th) = 1.17 to 0.96, and the EG by (230Th/232Th) = 1.01 to 0.88. Collectively, these data have a range in (230Th/232Th)-(238U/232Th) covering nearly the entire global MORB array. All samples have pristine (234U/238U) = 1.000 ±0.004 indicating that the 230Th-excesses and (230Th/232Th) are magmatic in origin. ^{226}Ra-excesses (in 9 of 10 samples analyzed) indicate that post-eruptive decay does not contribute significantly to the observed variations in 230Th-excess. The slope of a sample array on a U-Th equiline diagram may be an indicator of solid mantle upwelling rate (Lundstrom et al., 1998), with a shallower slope produced by slower upwelling. A linear regression of all the SEIR data has a slope (0.85), similar to that of the fast spreading southern East Pacific Rise. However, when the geographical groupings are considered, the slope is steepest in the EG (1.45), intermediate in the MG (0.81) and shallowest in the WG (0.57). This is opposite of the predicted trend at constant spreading rate, where faster upwelling would imply hotter mantle and thus produce shallower axial depths in the west. This suggests that variations in melt production and axial depth, along the SEIR, are not solely produced by a west- to-east decrease in mantle upwelling rate. There is also a progression from ? < ?Pb in the west to ? ? ?Pb in the east (where ? equals the measured Th/U and ?Pb equals the time integrated Th/U computed from Pb-isotope systematics). This progression is consistent with an increased contribution from older enriched mantle that has melted with less Th-U fractionation in the eastern portion of the study area. Collectively, our results suggest that along the SEIR the geochemical variations depend as much on what is melting as they do on how it melts.

  4. Magma dynamics at Mt Etna: Constraints from U-Th-Ra-Pb radioactive disequilibria and Sr isotopes in historical lavas

    Microsoft Academic Search

    Michel Condomines; Jean-Claude Tanguy; Vale´rie Michaud

    1995-01-01

    238U-230Th-226Ra-210Pb disequilibria and87Sr\\/86Sr ratios have been measured in a suite of prehistoric and historical lava flows from Mt. Etna. Whereas Th isotope ratios remain nearly constant during the whole period studied,226Ra and87\\/Sr86Sr data allow us to distinguish two mainepisodes in the volcanic history.For most of the past two millenia until 1970 A.D., Ra and Ba exhibit a similar behaviour (decreasing

  5. Constraining Rates of Chemical and Physical Erosion Using U-Series Radionuclides

    Microsoft Academic Search

    Nathalie Vigier; Bernard Bourdon

    \\u000a This chapter relates recent developments concerning the use of several U-series nuclides, in particular 234U-238U and 230Th-238U disequilibria, for constraining physical and chemical erosion rates and sediment age. Indeed, the ability to measure these\\u000a disequilibria with an extremely high precision, even in samples with low concentrations such as natural waters, has opened\\u000a new avenues for investigating erosional processes. This chapter

  6. Melt Migration in Oceanic Crustal Production: A U-series Perspective

    NASA Astrophysics Data System (ADS)

    Elliott, T.; Spiegelman, M.

    2003-12-01

    The crust is ultimately the product of mantle melting. To understand its formation requires knowledge of how melts move from depth. Generation of oceanic crust as a consequence of seafloor spreading is clearly related to melt production below. Although melting processes beneath ridges are perhaps the best constrained of any tectonic setting (see Chapter 3.13; Langmuir et al., 1992), neither melt distributions nor rates of melt migration are well resolved. It is necessary to infer dynamic processes hidden within the mantle by using proxy observations. Seismology provides important but static information on the velocity structure of the mantle, which is sensitive to the gross amount and distribution of partial melts (e.g., Forsyth et al., 1998). The geochemistry of erupted melts and their residues provides a different perspective, since their compositions are sensitive to the pathways they follow ( Hellebrand et al., 2002; Johnson et al., 1990; Kelemen et al., 1995a; Klein and Langmuir, 1987; Salters and Hart, 1989; Spiegelman, 1996). Furthermore, short-lived radioactive nuclides can provide crucial information on the rates of these processes.The aim of this chapter is to review the observations of uranium series nuclide studies on mid-ocean ridge basalts (MORBs) and discuss their implications for melt transport processes. We note that a recent review by Lundstrom (2003) has a similar remit and makes a useful companion contribution. We initially recap the fundamental behavior of the naturally occurring actinide decay chains, and outline the analytical challenges of their measurement. We then evaluate the gross signatures of disequilibrium observed in MORBs and consider the co-variations of disequilibria with other geochemical and geophysical parameters. This is followed by a detailed discussion of models of melt transport that have been developed to account for these observations, allowing a synthesis of the key constraints that uranium-series (henceforth U-series) measurements provide on the process of melt migration beneath mid-oceanic ridges.

  7. U SERIES DISEQUILIBRIA: INSIGHTS INTO MANTLE MELTING AND THE TIMESCALES OF MAGMA

    E-print Network

    Jellinek, Mark

    that decay directly to a stable daughter nuclide (e.g., 87 Rb ! 87 Sr, 147 Sm ! 143 Nd, and 176 Lu ! 176 Hf ), the long-lived isotopes of uranium and thorium (238 U, 235 U, and 232 Th) decay ultimately to isotopes

  8. 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

  9. 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.

  10. U-Series Dating of Tropical Stalagmites

    NASA Astrophysics Data System (ADS)

    Adkins, J. F.; Carolin, S. A.; Cobb, K.; Subhas, A. V.; Rider, A.; Meckler, N.

    2013-12-01

    Stalagmites are often seen as one of the ideal phases for U-series disequilibrium dating. Typically closed systems with high 234/238 ratios and little initial Th-230, these samples have yielded some of the most precise and accurate ages of the climate system over the last half million years. However, conditions in tropical cave systems can fail on all of these criteria, many times all of them at once. We use our set of over 400 U-series analyses in stalagmites and dozens of others from host rocks and drip waters from the karst region in Northern Borneo to show how problems with low uranium content, very depleted 234/238 ratios, and high ';detrital' thorium can be overcome to yield quality dates. Isochrons are an important tool, and we explore their advantages and weaknesses, but understanding the location and signature of hiatuses is also important. We have developed several geochemical lines of evidence for how to identify these pauses in stalagmite growth. In addition we explore how many of these conditions might come about and how they may be ubiquitous to tropical systems worldwide. The most puzzling observation is low 234/238 ratios. Ranging from near secular equilibrium to values below -600 permil, the missing U-234 requires some specific weathering scenarios to explain the complementary suite of rocks, waters, and stalagmites. Other Me/Ca data helps understand the degree that prior precipitation affects the range U-series data. Some simple numerical models of water moving through karst help us to understand the implications of these extensive data sets.

  11. Plume-ridge interaction studied at the Galápagos spreading center: Evidence from 226Ra- 230Th- 238U and 231Pa- 235U isotopic disequilibria

    NASA Astrophysics Data System (ADS)

    Kokfelt, Thomas Find; Lundstrom, Craig; Hoernle, Kaj; Hauff, Folkmar; Werner, Reinhard

    2005-05-01

    New 238U- 230Th- 226Ra and 231Pa- 235U disequilibria data measured by TIMS are presented for ridge-centered MORB glasses dredged during the R/V Sonne 158 cruise at the Galápagos or Cocos-Nazca Spreading Center (GSC) between 86.0°W and 92.3°W. The application of U-series isotopes to the GSC region, situated a few hundred kilometres to the north of the Galápagos hotspot, allows assessment of fundamental questions related to the dynamics of plume-ridge interaction. These include (1) the relationship between long-lived source variations, U-series disequilibria and extent of differentiation, (2) partial melting during solid upwelling, and (3) the nature and rates of plume-ridge mass transfer. The along axis U-series disequilibria variation show gradational patterns that locally are correlated with geochemical and isotopic parameters such as La/Sm, Tb/Yb, 206Pb/ 204Pb and 143Nd/ 144Nd as well as major element compositions. The correlation of ( 230Th)/( 238U) with radiogenic isotopes and Tb/Yb provides constraints on the plume source influence on the melting process, reflecting an increase in the amount of melting at depth in the presence of garnet or aluminous clinopyroxene. Moreover, the correlation between U-series signatures, radiogenic isotopes, incompatible element abundance and MgO content indicates a causative relationship between the melting of plume source materials and how these lavas differentiate at shallow depths. We speculate that this involves loss of alkalis from ascending melts to shallow peridotite and crustal gabbro, resulting in increased olivine fractionation from the magmas. The U-series data place stringent constraints on the timing of plume-ridge mass transfer and thus distinguish whether mass transfer occurs by movement of melts or solid mantle. Within the likely conditions proposed by the model of (Braun and Sohn [EPSL 213 (2003): 417-430] and with knowledge of ( 231Pa)/( 235U) and ( 230Th)/( 238U) observed in Galápagos Islands lavas [A. Saal, personal communication], we show that all 226Ra excess will be lost and the initial 231Pa and 230Th excesses will be largely decayed. Therefore, we conclude that the plume influence on the GSC lavas results from a solid mantle flow process instead of through migration of plume-derived melts to the ridge.

  12. Quantifying trace element disequilibria in mantle xenoliths and abyssal peridotites

    E-print Network

    Lee, Cin-Ty Aeolus

    distribution between orthopyroxene and clinopyroxene for quantifying rare earth element (REE) disequilibria in ultramafic rocks in the subsolidus state. We present case studies of the REE contents of mineral cores are known to be light REE-contaminated from the host lava. In the case of the abyssal peridotites, 13 out

  13. 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.

  14. 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.

  15. How precise are U-series coral ages?

    Microsoft Academic Search

    Denis Scholz; Augusto Mangini

    2007-01-01

    U-series dating of fossil reef corals is a well established and widely applied technique in paleoclimate research. Many fossil corals, however, show evidence for post-depositional diagenetic alteration, and it is generally accepted that the accuracy of U-series coral ages is more limited due to coral diagenesis than analytical precision. In recent years, three models have been published that try to

  16. U-series dating of Lake Nyos maar basalts, Cameroon (West Africa): Implications for potential hazards on the Lake Nyos dam

    NASA Astrophysics Data System (ADS)

    Aka, Festus T.; Yokoyama, Tetsuya; Kusakabe, Minoru; Nakamura, Eizo; Tanyileke, Gregory; Ateba, Bekoa; Ngako, Vincent; Nnange, Joseph; Hell, Joseph

    2008-09-01

    From previously published 14C and K-Ar data, the age of formation of Lake Nyos maar in Cameroon is still in dispute. Lake Nyos exploded in 1986, releasing CO 2 that killed 1750 people and over 3000 cattle. Here we report results of the first measurements of major elements, trace elements and U-series disequilibria in ten basanites/trachy-basalts and two olivine tholeiites from Lake Nyos. It is the first time tholeiites are described in Lake Nyos. But for the tholeiites which are in 238U- 230Th equilibrium, all the other samples possess 238U- 230Th disequilibrium with 15 to 28% enrichment of 230Th over 238U. The ( 226Ra/ 230Th) activity ratios of these samples indicate small (2 to 4%) but significant 226Ra excesses. U-Th systematics and evidence from oxygen isotopes of the basalts and Lake Nyos granitic quartz separates show that the U-series disequilibria in these samples are source-based and not due to crustal contamination or post-eruptive alteration. Enrichment of 230Th is strong prima facie evidence that Lake Nyos is younger than 350 ka. The 230Th- 226Ra age of Nyos samples calculated with the ( 226Ra/ 230Th) ratio for zero-age Mt. Cameroon samples is 3.7 ± 0.5 ka, although this is a lower limit as the actual age is estimated to be older than 5 ka, based on the measured mean 230Th/ 238U activity ratio. The general stability of the Lake Nyos pyroclastic dam is a cause for concern, but judging from its 230Th- 226Ra formation age, we do not think that in the absence of a big rock fall or landslide into the lake, a big earthquake or volcanic eruption close to the lake, collapse of the dam from erosion alone is as imminent and alarming as has been suggested.

  17. Dispersion of U-series natural radionuclides in stream sediments from Edale, UK.

    PubMed

    Siddeeg, Saifeldin M; Bryan, Nicholas D; Livens, Francis R

    2014-05-01

    The spatial distribution of (238)U-series radionuclides, specifically 238U, 234U, 230Th and 226Ra, has been determined in stream sediments from Edale, Derbyshire, United Kingdom, to explore the behaviour of U-series radionuclides during weathering. For uranium and thorium, two different extraction methods were used, total dissolution with HNO3/HF in a microwave and leaching with aqua regia. This was followed by radiochemical separation using extraction chromatography, then alpha spectrometry measurement. The total radium contents in the sediments were measured using gamma spectrometry, while the leached fraction was measured in the same way as for uranium and thorium. The total sediment content of uranium and thorium ranges from ?10 up to ?200 Bq kg(-1), while the radium specific activity lies between ?15 and 180 Bq kg(-1). In the aqua regia extractions, the uranium and thorium contents are in the range of ?5 to ?100 Bq kg(-1), while the radium specific activities are similar to those measured by total dissolution. All the radionuclides show no correlation with organic matter content. The activity ratios 234U/238U, 230Th/238U and 226Ra/238U were used to determine the degree of radioactive disequilibrium. The data show disequilibrium in most of the sediments, with activity ratios of 234U/238U, 230Th/238U and 226Ra/238U>1, inconsistent with evolution through straightforward weathering processes. Multivariate cluster analysis based on five variables, the specific activities of 238U, 234U, 230Th, 226Ra and loss on ignition, was employed to group the data and identify five distinct clusters. There seems to be a link between high radionuclide concentrations and proximity to landslips. PMID:24562972

  18. Modeling U-Series Concordia/Discordia Using STELLA

    NSDL National Science Digital Library

    Kirsten Menking

    U-Series dating techniques are widely used to determine the absolute ages of some of Earth's oldest rocks, but the concordia/discordia diagram can be quite difficult for students to grasp. In particular, the fact that differing amounts of lead and uranium loss from minerals such as zircon can be used to determine not only the original formation age, but also the time of metamorphism of a rock like granite, is a challenging concept. Making use of previous workers' web-published excercises on radiometric decay, I have produced a STELLA-based lab exercise to develop students' understanding of this important chronologic technique. Students create models of the two isotopic decay systems, 238U --> 206Pb and 235U --> 207Pb, and run these models for 4.5 billion years to create the concordia diagram. They then carry out experiments in which they "add" or "remove" varying amounts of lead or uranium in simulation of metamorphism. The uranium-lead ratios at the end of the simulation allow the discordia line to be plotted on top of the concordia diagram and the ages of original crystallization and metamorphism to be determined from the points of intersection of the two lines. In the course of the lab, students are introduced to the concepts of exponential decay and secular equilibrium as well as modeling concepts such as the creation of if-then statements.

  19. 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.

  20. 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.

  1. Precise microsampling of poorly laminated speleothems for U-series dating

    NASA Astrophysics Data System (ADS)

    Drysdale, R.; Paul, B.; Hellstrom, J.; Couchoud, I.; Greig, A.; Bajo, P.; Zanchetta, G.; Isola, I.; Spötl, C.; Baneschi, I.; Regattieri, E.; Woodhead, J.

    2012-04-01

    Speleothems are recognised as important palaeoclimate archives partly because of the ability to date them accurately and precisely by uranium-series (U-series) methods. The practicalities of sampling speleothem sections for U-series dating are, in most cases, fairly straightforward due to the presence of visible growth layers. However, not all speleothems possess this property, which depends upon the conditions of calcium carbonate precipitation. In this paper, we describe a method for generating U-series dating samples in which growth layers are resolved from trace-element images produced by laser-ablation inductively coupled plasma mass spectrometry (LA-ICP-MS). We apply this method to a section of an Italian subaqueous speleothem (CD3) that lacks persistent visible growth layering. The trace-element imaging revealed growth layers that are strongly non-planar in their geometry owing to the speleothem's pronounced euhedral crystal terminations. The most prominent trace-element layers were first digitized as x,y vector contours. We then interpolated these in the growth-axis direction to generate a series of contour lines at ~250-?m increments. The coordinates of these contours were used to guide the sampling via a computerised micromilling lathe. This produced a total of 22 samples for U-series dating by multi-collector ICP-MS. The dating results returned ages in correct stratigraphic order within error. Close inspection of the U-series data suggests that the main sources of age uncertainty are unrelated to the contour sampling. Comparisons between stable oxygen and carbon isotope profiles derived from aliquots of the dating samples and two other stable isotope profiles from CD3 spanning the same time period compare very favourably. Taken together, this suggests that our trace-element contouring method provides a reliable means for extracting samples for dating (and other geochemical analyses), and can be applied to similar speleothems lacking visible growth layering.

  2. 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

  3. /sup 234/Th: /sup 238/U disequilibria within the California Current

    SciTech Connect

    Coale, K.H.; Bruland, K.W.

    1985-01-01

    Profiles of dissolved and particulate /sup 234/Th were determined at several stations within the California Current. Modeling of the disequilibria between the /sup 234/Th and /sup 238/U within the surface waters provides for estimates of the residence time of dissolved thorium with respect to particle scavenging, the particle residence time, and the particulate /sup 234/Th flux exiting the surface layer. The model-derived, first-order scavenging rate constant for dissolved thorium is observed to be proportional to the rate of primary production. Particle residence times seem to be governed by the rate of zooplankton grazing and the types of zooplankton present. Model-derived particulate /sup 234/Th fluxes are in good agreement with direct measurements by sediment traps.

  4. 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.

  5. 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.

  6. U-series evidence for crustal involvement and magma residence times in the petrogenesis of Parinacota volcano, Chile

    NASA Astrophysics Data System (ADS)

    Bourdon, B.; Wörner, G.; Zindler, A.

    In this study, we present Th-U disequilibria as well as radiogenic and trace element data for recent volcanic rocks from the Nevados de Payachata volcano which erupted through 70km of continental crust in the Central Volcanic Zone of the Andes (18°S, 69°W). Both lavas and mineral separates were analyzed by mass spectrometry for 238U-230Th disequilibria. The lavas are characterized either by 230Th enrichment or depletion relative to its parent nuclide 238U. Mineral separates are used to derive U-Th isochron ages and these ages compare favorably with inferred stratigraphic ages or K-Ar ages, although in one case the U-Th age is significantly older than the stratigraphic age. Despite relatively constant Sr, Nd, and Pb isotope ratios, the lavas display inverse trends in 230Th/238U versus Ce/Yb or Ba/Hf diagrams. These trends cannot be interpreted by simple two-component mixing. Rather, there must be three (and perhaps four components) involved in the genesis of the Parinacota lavas. A mantle wedge, a slab fluid, and a lower crustal component can be identified. A sediment component is more difficult to detect as it is difficult to decipher its signature because of the strong crustal influence. The existence of binary arrays can be explained by variable amounts of crustal material. The process of crust-mantle interaction must have been short enough to preserve U-Th disequilibrium (<300ka).

  7. Seasonal and spatial dynamics of 234Th/238U disequilibria in southern Lake Michigan

    NASA Astrophysics Data System (ADS)

    Waples, James T.; Orlandini, Kent A.; Edgington, David N.; Klump, J. Val

    2004-10-01

    Measurements of 234Th/238U disequilibria were made on an approximately bimonthly basis over the course of a year in nearshore (10-40 m deep) and offshore (160 m deep) surface waters of the southern basin of Lake Michigan (18,100 km2). The mean activity of 238U in Lake Michigan measured 230 ± 20 dpm m-3, approximately 1 order of magnitude lower than what is typically found in marine systems. Measured median activities of dissolved (<0.45 ?m) and excess particle-bound 234Th were 8.0 and 60.6 dpm m-3, respectively. Using a simple one-dimensional model, median residence times for dissolved and particle-bound 234Th were ˜1 and ˜14 days, respectively. 234Th-based particle settling velocities had a median value of 0.4 m d-1 (range: ˜0.0-1.4 m d-1), and instantaneous 234Th-based estimates of the net vertical mass flux had a median value of 0.4 g m-2 d-1 (range: ˜0.0-5.2 g m-2 d-1). Average particle settling velocities were generally constant over time and increased only slightly in the shallowest (10 m) sampling stations. Calculated mass fluxes showed a strong correlation with temporal and spatial changes in the concentration of total suspended matter, which, in the nearshore area, closely followed seasonal variations in wind-induced wave height. Using a simple two-box model, the 234Th-based cross-margin mass export rate for the entire southern basin of Lake Michigan was equal to 1.35 × 109 kg yr-1, which is in excellent agreement with a 210Pb - 137Cs based, basin-wide mass sedimentation rate of 1.28 × 109 kg yr-1.

  8. Internal tides and sediment dynamics in the deep sea—Evidence from radioactive 234Th\\/ 238U disequilibria

    Microsoft Academic Search

    Robert Turnewitsch; Jean-Louis Reyss; Jonas Nycander; Joanna J. Waniek; Richard S. Lampitt

    2008-01-01

    Residual flow, barotropic tides and internal (baroclinic) tides interact in a number of ways with kilometer-scale seafloor topography such as abyssal hills and seamounts. Because of their likely impact on vertical mixing such interactions are potentially important for ocean circulation and the mechanisms and the geometry of these interactions are a matter of ongoing studies. In addition, very little is

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

    SciTech Connect

    Stein, M.; Wasserburg, G.J.; Chen, J.H. (California Inst. of Tech., Pasadena (United States)); Lajoie, K.R. (Geological Survey, Menlo Park, CA (United States))

    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.

  10. Recycling of the Chalupas pluton at Cotopaxi volcano, NVZ, Ecuador: Evidence from 238U-230Th disequilibria

    Microsoft Academic Search

    J. Garrison; J. Davidson; S. Turner; M. Reid

    2003-01-01

    Cotopaxi Volcano is located in the Northern Volcanic Zone (NVZ) of the S. American Andes. It is constructed near the rim of the Chalupas Caldera, which erupted the Chalupas ignimbrite approximately 230 ka ago. An ignimbrite with chemistry identical to the Chalupas ignimbrite was erupted from Cotopaxi at 4.5 ka, and is called the Colorado Canyon ignimbrite. Recently acquired U-series

  11. High-precision U-series measurements of more than 500,000 year old fossil corals

    Microsoft Academic Search

    Morten B. Andersen; Claudine H. Stirling; Emma-Kate Potter; Alex N. Halliday; Steven G. Blake; Malcolm T. McCulloch; Bridget F. Ayling; Michael O'Leary

    2008-01-01

    Robust, independent age constraints on the absolute timing of climate events based on the U-series dating of fossil coral are sparse before the last glacial cycle. Using multiple-collector inductively coupled plasma mass spectrometry with multiple-Faraday protocols, we are able to date ?600 ka samples with an uncertainty of better than ±15 ka (2?), representing a three-fold improvement in precision compared with previous

  12. Rapid Climate Oscillations During the Last Deglaciation Synchronised by TIMS U-series Dating of a Stalagmite in East China

    Microsoft Academic Search

    J. Zhao; Y. Wang; K. D. Collerson; M. K. Gagan

    2001-01-01

    Evidence for nearly synchronous climate oscillations during the last deglaciation has been found throughout the Northern Hemisphere but few records are based on independent time-scales of calendar years. We present the first U-series dated oxygen-carbon isotope record for a speleothem from Tangshan Cave, east China, which demonstrates unambiguously that abrupt deglacial climatic oscillations from 16,800 to 10,500 years BP are

  13. DNA polymorphism of alkaline phosphatase isozyme genes: Linkage disequilibria between placental and germ-cell alkaline phosphotase alleles

    SciTech Connect

    Beckman, G.; Beckman, L.; Sikstroem, C. (Univ. of Umea (Sweden)); Millan, J.L. (La Jolla Cancer Research Foundation, CA (United States))

    1992-11-01

    The use of human placental alkaline phosphatase (PLAP) cDNA as a probe allows the detection and identification of restriction DNA fragments derived from three homologous genes, i.e., intestinal alkaline phosphatase (AP), germ-cell AP (GCAP), and PLAP. In previous RFLP studies the authors have reported linkage disequilibria between an RsaI and two PstI (a and b) polymorphic restriction sites and electrophoretic types of PLAP. In this report they present evidence that, in spite of the strong correlation with PLAP types, PstI(b) is an RFLP of GCAP. The data indicate close linkage between the PLAP and GCAP loci. 18 refs., 2 figs., 3 tabs.

  14. 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

  15. 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.

  16. 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.

  17. 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

  18. Dacite formation at Ilopango Caldera, El Salvador: U-series disequilibrium and implications for petrogenetic processes and magma storage time

    NASA Astrophysics Data System (ADS)

    Garrison, Jennifer M.; Reagan, Mark K.; Sims, Kenneth W. W.

    2012-06-01

    Ilopango Caldera was formed ˜1810 years ago by eruption of the Tierra Blanca Joven (TBJ) dacite (70 km3) in central El Salvador. A subsequent eruption in 1880 produced a cluster of dacite domes in the center of Lago Ilopango that contain olive-bearing enclaves of basaltic andesite. The purpose of this study is to use trace element, isotope, and U-series data from the TBJ and 1880 eruptions to assess petrogenesis and the timescale of magma storage. We find that although the range of trace element data in the TBJ dacite can be reproduced by simple crystal fractionation of a plagioclase- and amphibole-rich mineral assemblage, the87Sr/86Sr and 207Pb/204Pb data suggest that the 1880 basaltic andesite enclave has a different source than the dacites. This is consistent with U-series data that show the TBJ dacites have lower (230Th/232Th) than the 1880 basaltic andesite enclave (1.5 versus 1.6, respectively). All Ilopango rocks have 230Th excesses, and the range in (238U/232Th) of the TBJ dacites can be modeled by crystal fractionation of a mineral assemblage including accessory zircon and allanite from a magma that is similar in composition to the enclave. Mineral isochrons yield crystallization ages of <10,000 years, and disequilibrium (226Ra/230Th) values suggest a similarly short residence time. Our data suggest that the large volumes of erupted dacite at Ilopango Caldera are generated very rapidly.

  19. 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. (Arizona State Univ., Tempe (United States)); Sturchio, N.C. (Argonne National Lab., IL (United States)); Murrell, M.T. (Los Almos National Lab., NM (United States))

    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.

  20. 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.

  1. 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.

  2. 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.

  3. Coupling data from U-series and 10Be CRN to evaluate soil steady-state in the Betic Cordillera

    NASA Astrophysics Data System (ADS)

    Schoonejans, Jerome; Vanacker, Veerle; Opfergelt, Sophie; Granet, Mathieu; Chabaux, François

    2015-04-01

    The regolith mantel is produced by weathering of bedrock through physical and biochemical processes. At the same time, the upper part of the regolith is eroded by gravity mass movements, water and wind erosion. Feedback's between production and erosion of soil material are important for soil development, and are essential to reach long-term steady-state in soil chemical and physical properties. Nowadays, long-term denudation rates of regolith can be quantified by using in-situ cosmogenic nuclides (CRN). If the soil thickness remains constant over sufficiently long time, soil production rates can be determined. However, the a priori assumption of long-term steady-state can be questionable in highly dynamic environments. In this study, we present analytical data from two independent isotopic techniques, in-situ cosmogenic nuclides and Uranium series disequilibrium. The disequilibrium of Uranium isotopes (238U, 234U, 230Th, 226Ra) is an alternative method that allows assessing soil formation rates through isotopic analysis of weathering products. Nine soil profiles were sampled in three different mountain ranges of the Betic Cordillera (SE Spain): Sierra Estancias, Filabres, Cabrera. All soils overly fractured mica schist and are very thin (< 60cm). In each soil profile, we sampled 4 to 6 depth slices in the soil profile, the soil-bedrock interface and (weathered) bedrock. Three of the nine soil profiles were sampled for U-series isotope measurements at EOST (University of Strasbourg). The surface denudation rates (CRN) are about the same in the Sierra Estancias and Filabres (26 ± 10 mm/ky) and increase up to 103 ± 47 mm/ky in the Sierra Cabrera. The spatial variation in soil denudation rates is in agreement with the variation in catchment-wide denudation rates presented by Bellin et al. (2014) which present the highest rates in the Sierra Cabrera (104-246mm/kyr). Moreover it roughly coincides with the pattern of long-term exhumation of the Betic Cordillera. Results from first simulations of the U-series disequilibrium model rather suggest that soil production rates are of the same order of magnitude in the Sierra Estancias and Cabrera. In the Sierra Filabres, the U-series disequilibrium in the depth profile do not respect the hypotheses of the model therefore no rates of soil production could be constrain for this profile. Thanks to the coupling of the two isotopic datasets the long term soil development will be explored in two profiles. This study highlights that comparison and combination of analytical techniques is useful to further unravel the mechanisms of chemical and physical weathering in such dynamic environments. Bellin, N., Vanacker, V., and Kubik, P. W., 2014, Denudation rates and tectonic geomorphology of the Spanish Betic Cordillera: Earth and Planetary Science Letters, v. 390, p. 19-30.

  4. High-precision U-series dating of corals from Western Australia and implications for the timing and duration of the Last Interglacial

    Microsoft Academic Search

    C. H. Stirling; T. M. Esat; M. T. McCulloch; K. Lambeck

    1995-01-01

    U-series ages using methods of thermal ionisation mass spectrometry (TIMS) are reported for Last Interglacial fossil reefs along the stable coastal margin of Western Australia. Thorium isotope ratios were measured with superior precision using methods of charge collection. High levels of precision in the measurement of both uranium and thorium isotopes has reduced the age uncertainty due to analytical errors,

  5. Timing and warmth of the Last Interglacial period: new U-series evidence from Hawaii and Bermuda and a new fossil compilation for North America

    Microsoft Academic Search

    Daniel R. Muhs; Kathleen R. Simmons; Bree Steinke

    2002-01-01

    The timing and duration of the Last Interglacial period have been controversial, with some studies suggesting a relatively short duration that is orbitally forced and others suggesting a long duration that is at most only partly related to orbital forcing. New, high-precison thermal ionization mass spectrometric (TIMS) U-series ages of Last Interglacial corals from Hawaii and Bermuda test these competing

  6. Radioactive wastes

    Microsoft Academic Search

    Devarakonda

    1993-01-01

    This paper reviews research and technological progress in radioactive waste management and disposal. The scope of material covered is very broad, ranging from international cooperation in radioactive waste management to evaluation of specific treatment technologies. The issue of safely managing and disposing of the plutonium resulting from the dismantling of weapons across the world is discussed and a series of

  7. A combined U-series, radiocarbon and stable isotope approach for constructing a Pleistocene lake hydrograph: an example from Surprise Valley, California

    NASA Astrophysics Data System (ADS)

    Ibarra, D. E.; Weaver, K. L.; Harris, C.; Maher, K.

    2013-12-01

    Lake records and lake hydrographs provide an integrated record of the hydrologic conditions across a watershed. To provide useful constraints on past changes in climate, robust hydrographs require concordance among multiple geochronologic approaches as well as supporting geochemical and hydrologic evidence. Dating shoreline or near-shore lacustrine carbonates using U-series and radiocarbon methods is one approach for developing the age-elevation constraints to construct lake hydrographs. Geochemical analyses (e.g., stable isotopes, elemental ratios, U-series measurements) of modern waters and sediments, as well as the primary carbonate samples, can be used to assess the potential influence of open-system behavior, detrital Th corrections, or pedogenic overprinting on the calculated ages. Additionally, topographic analyses (e.g., basin pour point, shoreline elevations and sample locations) further constrain the spatial relevance and relationships between sample localities. To evaluate the timing and magnitude of the most recent late Pleistocene lake cycle in Surprise Valley, California, we analyzed 111 sub-samples from 22 laminated shoreline tufa samples using U-series disequilibrium geochronology, and pair these analyses with 15 radiocarbon ages. To further assess the radiocarbon and U-series ages, we measured the stable isotope (?18O and ?13C) and elemental (Sr/Ca) signatures of the tufa samples, and characterized the range of (234U/238U) observed in the modern waters and playas within the watershed. Topographic analysis verified that Lake Surprise is a closed, inward draining basin, and demonstrated lateral correspondence between samples from the four targeted shoreline sets. Multiple lines of evidence revealed that samples from the highest shorelines are likely from older, higher lake cycles and were influenced by variable amounts of open-system exchange or pedogenic overprinting. The measured U concentrations of ~300 to 1200 ng/g, with (238U/232Th) from ~3 to 12, and (230Th/232Th) as low as 1.7, required correction procedures to produce accurate ages. Using the Total Sample Dissolution method on suites of >5 sub-samples, we calculated U-series isochron ages using paired 2-D Rosholt isochrons determined by error-weighted linear least squares regressions. We found concordance between most isochron ages and single sample detrital Th corrected ages. Additionally, Rosholt isochron ((238U/232Th) vs. (230Th/232Th)) intercepts and modern carbonate measurements indicate that the (230Th/232Th) of the detrital Th end-member has remained consistent, at a value of ~1.3. Most samples demonstrated concordance between the U-series ages and radiocarbon ages, but four samples had U-series ages that were on average ~1.35 kyr older than the paired radiocarbon ages. Spanning 10 to 30 ka, this new lake hydrograph places the highest lake level, ~176 m above present-day playa, at >15.2 ka. During the Last Glacial Maximum (19 to 26 ka) Lake Surprise stood at moderate levels, at ~80 m above modern playa. This coupled approach to hydrograph construction demonstrates how age-elevation data from multiple geochronologic methods can be corroborated and interpreted within the context of geochemical and topographic analyses.

  8. 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.

  9. 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)

  10. Radioactive Iodine

    MedlinePLUS

    ... form of iodide, is made into two radioactive isotopes that are commonly used in patients with thyroid ... the best results? I-123 is the usual isotope used to take pictures and determine the activity ...

  11. Radioactive Decay

    NSDL National Science Digital Library

    Barker, William

    Created by William Barker and David Smith for the Connected Curriculum Project, this module develops a mathematical model for decay of radioactive substances, and a technique for deciding whether quantitative data fits the model or not. This is one within a much larger set of learning modules hosted by Duke University.

  12. Radioactive Wastes

    NSDL National Science Digital Library

    David Smith

    Using Mathcad, Maple, Mathmatica, or MatLab, the user should be able to develop multiple representations for decay of radioactive substances, in the context of environmental policies on a university campus, and to determine storage times for wastes to decay to safe levels for disposal.

  13. Radioactive Wastes

    NSDL National Science Digital Library

    Smith, David

    Created by David Smith for the Connected Curriculum Project, this module develops multiple representations for decay of radioactive substances, in the context of environmental policies on a university campus, and discusses storage times for wastes to decay to safe levels for disposal. This is one of a much larger set of learning modules hosted by Duke University.

  14. Radioactive Transitions

    NSDL National Science Digital Library

    This resource provides an interactive activity demonstrating how radioactive transitions (photon absorption and stimulated emission) occur in an optical field. Many important phenomena are emergent behaviors of this dynamic model. An interactive diagram is presented allowing students to experiment and watch a simulation of the result.

  15. Investigation of aerial dispersion of radioactive dust from an open-pit uranium mine by passive vinyl collectors

    Microsoft Academic Search

    H. B. L. Pettersson; J. Koperski

    1991-01-01

    Detailed investigations of the aerial dispersion of radioactive dust from the biggest open-pit U mining and milling operation in Australia were carried out. Spatial distributions of the long-lived radionuclides of ²³⁸U series and their origin, i.e., mining and milling operations vs. natural background radiation, have been studied. Horizontal flux, dry deposition, and ground resuspension of the radionuclides were investigated along

  16. Timing and warmth of the Last Interglacial period: New U-series evidence from Hawaii and Bermuda and a new fossil compilation for North America

    USGS Publications Warehouse

    Muhs, D.R.; Simmons, K.R.; Steinke, B.

    2002-01-01

    The timing and duration of the Last Interglacial period have been controversial, with some studies suggesting a relatively short duration that is orbitally forced and others suggesting a long duration that is at most only partly related to orbital forcing. New, high-precison thermal ionization mass spectrometric (TIMS) U-series ages of Last Interglacial corals from Hawaii and Bermuda test these competing hypotheses. Waimanalo Formation corals from slowly uplifting Oahu, Hawaii range in age from ???134 to ???113 ka, with most ages between ???125 and ???115 ka. Combined with published U-series ages from nearby Lanai, the data suggest a long Last Interglacial period that may have occurred from ???136 to at least 115 ka. The results indicate that orbital forcing may not have been the only control on ice sheet growth and decay, because sea level would have been high at times of relatively low Northern Hemisphere summer insolation. On tectonically stable Bermuda, deposits from the ???200 ka (penultimate interglacial period), ???120 ka (peak Last Interglacial period) and ???80 ka (late Last Interglacial period) high sea stands have been newly dated. Fossil corals on Bermuda are derived from patch reefs that likely were "catch-up" responses to sea level rise. It is expected that U-series ages of Last-Interglacial corals on Bermuda should overlap with, but not be as old as the range of corals on Oahu. Last-Interglacial corals on Bermuda give a range of ???125-113 ka, which supports this hypothesis. A large number of emergent marine deposits on Hawaii, Bermuda and along coastal North America have now been dated to the Last Interglacial period. Both Oahu and Bermuda have marine invertebrate faunas with a number of extralimital southern species of mollusks, suggesting warmer-than-present waters during the Last Interglacial period. Warmer waters are also suggested for Last-Interglacial localities around most of North America, from Florida to Canada and Greenland and Baja California to Alaska. These observations are consistent with similar warm-water faunas of Last-Interglacial age reported from Japan, the Mediterranean basin and Western Australia. It is likely that significant changes in ocean currents took place during the Last Interglacial period, with a movement of relatively warm waters to higher latitudes than is the case today. ?? 2002 Elsevier Science Ltd. All rights reserved.

  17. Radioactive Wastes

    NSDL National Science Digital Library

    Moore, Lang

    Created by Lang Moore and David Smith for the Connected Curriculum Project, the purposes of this module are to develop multiple representations for decay of radioactive substances, in the context of environmental policies on a university campus, and to determine storage times for wastes to decay to safe levels for disposal. This is one lesson within a larger set of learning modules hosted by Duke University.

  18. 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

  19. High resolution analysis of uranium and thorium concentration as well as U-series isotope distributions in a Neanderthal tooth from Payre (Ardèche, France) using laser ablation ICP-MS

    NASA Astrophysics Data System (ADS)

    Grün, Rainer; Aubert, Maxime; Joannes-Boyau, Renaud; Moncel, Marie-Hélène

    2008-11-01

    We have mapped U ( 238U) and Th ( 232Th) elemental concentrations as well as U-series isotope distributions in a Neanderthal tooth from the Middle Palaeolithic site of Payre using laser ablation ICP-MS. The U-concentrations in an enamel section varied between 1 and 1500 ppb. The U-concentration maps show that U-migration through the external enamel surface is minute, the bulk of the uranium having migrated internally via the dentine into the enamel. The uranium migration and uptake is critically dependent on the mineralogical structure of the enamel. Increased U-concentrations are observed along lineaments, some of which are associated with cracks, and others may be related to intra-prismatic zones or structural weaknesses reaching from the dentine into the enamel. The uranium concentrations in the dentine vary between about 25,000 and 45,000 ppb. Our systematic mapping of U-concentration and U-series isotopes provides insight into the time domain of U-accumulation. Most of the uranium was accumulated in an early stage of burial, with some much later overprints. None of the uranium concentration and U-series profiles across the root of the tooth complied with a single stage diffusion-adsorption (D-A) model that is used for quality control in U-series dating of bones and teeth. Nevertheless, in the domains that yielded the oldest apparent U-series age estimates, U-leaching could be excluded. This means that the oldest apparent U-series ages of around 200 ka represent a minimum age for this Neanderthal specimen. This is in good agreement with independent age assessments (200-230 ka) for the archaeological layer, in which it was found. The Th elemental concentrations in the dental tissues were generally low (between about 1 and 20 ppb), and show little relationship with the nature of the tissue.

  20. Enhancing in-situ U-series accessory mineral chronometry to constrain pace and processes of magma accumulation, storage, and eruption

    NASA Astrophysics Data System (ADS)

    Schmitt, A. K.

    2008-12-01

    Over the past decade, deciphering absolute crystallization ages at micro-scales through in-situ U-series dating has spearheaded conceptual changes in the understanding of how magmas evolve en route to the surface. U-Th and U-Pb zircon geochronology by secondary ionization mass spectrometry (SIMS) now routinely accesses a continuous age spectrum extending well into the Holocene with ka precision for individual analysis spots ~25 - 40 ?m in diameter. SIMS depth profiling further increases spatial resolution at least tenfold. These developments are epitomized by studies that document multiple generations of zircon growth, predating eruptions by 10's to 100's of ka, as common features in silicic volcanics. Recently, these methods have been enhanced by (1) linking ages to Ti-in-zircon thermometry and trace element or oxygen isotopic fingerprinting; (2) tracking compositional changes with age in accessory minerals sensitive to magma differentiation, such as allanite; and (3) combining U-Th zircon ages with other chronometers, such as (U-Th)/He zircon or 226Ra-230Th-238U plagioclase dating. The emerging picture reveals a wide gamut of processes acting in magma bodies, including piecemeal, compartmentalized magma aggregation, protracted and thermally retrograde crystal storage coupled with magma differentiation, thermal rejuvenation and recycling of crystal mushes and solidified intrusions or magma chamber rinds, and wall rock assimilation. For the future, experimental constraints on accessory mineral-melt partitioning (e.g., Ayers and Luo, 2008: Geochim Cosmochim Acta, v. 72, p. A39) promise to put interpretation of zircon compositions on firmer footing, as is the case for additional accessory mineral saturation calibrations and improved modeling of existing ones (e.g., Harrison et al., 2007: Geology, v. 35, p. 635-638). By the same token, new experimental constraints on U-series element partitioning (e.g., Miller et al., 2007: Am Min, v. 92, p. 1535-1538) should enhance precision and applicability of mineral chronometers. Moreover, analytical advances in high spatial resolution SIMS hold promise for utilizing melt inclusions in zircon as an additional repository for constraining the chemical and thermal evolution of magmas.

  1. Radioactive Materials Product Stewardship

    E-print Network

    Radioactive Materials Product Stewardship ABackground Report for the National Dialogue on Radioactive Materials Product Stewardship Prepared by the: Product Stewardship Institute University....................................................................................................................................................................6 3. PRODUCT STEWARDSHIP

  2. Timescales of magmatic processes and eruption ages of the Nyiragongo volcanics from 238U- 230Th- 226Ra- 210Pb disequilibria

    NASA Astrophysics Data System (ADS)

    Chakrabarti, Ramananda; Sims, Kenneth W. W.; Basu, Asish R.; Reagan, Mark; Durieux, Jacques

    2009-10-01

    The silica-undersaturated Nyiragongo volcanics, located in the East African Rift, have globally unique chemical compositions and unusually low viscosities, only higher than carbonatite lavas, for terrestrial silicate magmas. We report 238U- 230Th- 226Ra- 210Pb series disequilibria in 13 recent and prehistoric lava samples from Nyiragongo including those from the 2002 flank eruption and a 2003 lava lake sample. ( 230Th/ 238U) ranges from 0.90 to 0.97 in the recent lavas and from 0.94 to 1.09 in the prehistoric lavas. To explain the variable 230Th and 238U excesses in these lavas, we hypothesize that different processes with opposite effects in terms of fractionating Th/U in the mantle source are involved. These processes include: 1) low degree partial melting of a phlogopite-bearing mantle source (consistent with low K/Rb) with residual garnet (consistent with high chondrite-normalized Dy/Yb), to produce the observed 230Th excesses; and, 2) carbonate metasomatism for the 238U enrichment, consistent with high Zr/Hf in the Nyiragongo lavas. The Nyiragongo volcanics have higher ( 230Th/ 232Th) values than observed in most mantle-derived rocks, especially ocean-island basalts, suggesting that their mantle source was affected by carbonate metasomatism less than 300 ka ago. Several Nyiragongo samples display significant 226Ra excesses implying rapid magma transport (less than 8 ka) from the mantle source to the surface. Modeling the observed ( 226Ra/ 230Th) versus Zr/Hf correlation in the lavas indicates that the 2002, 2003 and a few prehistoric lavas incorporated 50-60% of a carbonate-metasomatized mantle source while the other prehistoric lavas show 10-22% contribution of this source. This result indicates that the Nyiragongo lavas were derived from a heterogeneous, non-uniformly carbonated mantle source. The 2002 lava shows ( 210Pb/ 226Ra) equilibrium, whereas the 2003 lava lake sample shows initial ( 210Pb/ 226Ra) < 1. The latter observation suggests that Nyiragongo magmas degas as they rise to the surface over years or decades before eruption. ( 210Pb/ 226Ra) equilibrium in the 2002 lava suggests that the 2002 magma may have stagnated for more than a decade before eruption. The high CO 2 content, high emission rates, extreme fluidity, along with the inferred short residence time and our inferences of rapid magma transport and high eruptive frequency suggest that the volcanic hazards of Nyiragongo, both from lava flows and gas emissions, are higher than previously estimated.

  3. 238U-230Th-226Ra-210Pb disequilibria study of the Nyiragongo volcanics from the East African Rift: implications for timescales of magmatic processes and eruption ages

    NASA Astrophysics Data System (ADS)

    Chakrabarti, R.; Sims, K. W.; Basu, A. R.; Reagan, M. K.; Durieux, J.

    2009-12-01

    The silica-undersaturated Nyiragongo volcanics, located in the East African rift, show globally unique chemical compositions and among the lowest recorded viscosity among terrestrial silicate magmas, only higher than carbonatite lavas. We report 238U-230Th-226Ra-210Pb series disequilibria in 13 recent and prehistoric lava samples from Nyiragongo including those from the 2002 flank eruption and a 2003 lava lake sample. (230Th/238U) ranges from 0.90-0.97 in the recent lavas and from 0.94-1.09 in the prehistoric lavas. To explain the variable 230Th and 238U excesses in these lavas, we hypothesize that different processes with opposite effects in terms of fractionating Th/U in the mantle source are involved. These processes include: 1) low degree partial melting of a phlogopite-bearing mantle source (consistent with low K/Rb) with residual garnet (consistent with high chondrite-normalized Dy/Yb), to produce the observed 230Th excesses; and, 2) carbonate metasomatism for the 238U enrichment, consistent with high Zr/Hf in the Nyiragongo lavas. The Nyiragongo volcanics have higher (230Th/232Th) values than observed in most mantle-derived rocks, especially ocean-island basalts, suggesting that their mantle-source was affected by carbonate metasomatism less than 300 ka ago. Several Nyiragongo samples display significant 226Ra excesses implying rapid magma transport (less than 8 ka) from the mantle-source to the surface. Modeling the observed (226Ra/230Th) versus Zr/Hf correlation in the lavas indicates that the 2002, 2003 and a few pre-historic lavas incorporated 50-60% of a carbonate-metasomatized mantle source while the other pre-historic lavas show 10-22% contribution of this source. This result indicates that the Nyiragongo lavas were derived from a heterogeneous, non-uniformly carbonated mantle source. The 2002 lava shows (210Pb/226Ra) equilibrium, whereas the 2003 lava lake sample shows initial (210Pb/226Ra) < 1. The latter observation suggests that Nyiragongo magmas degas as they rise to the surface over years or decades before eruption. (210Pb/226Ra) equilibrium in the 2002 lava suggests that the 2002 magma may have stagnated for more than a decade before eruption. The high CO2 content, high emission rates, extreme fluidity, along with the inferred short residence time and our inferences of rapid magma transport and high eruption frequency suggest that the volcanic hazards of Nyiragongo, both from lava flows and gas emissions, are higher than previously estimated.

  4. A multi-isotopic study (U-series, 14C, 13C, 18O) on growth of Arctic fissure calcretes (endostromatolites) from Northern Canada.

    NASA Astrophysics Data System (ADS)

    Ghaleb, B.; Hillaire-Marcel, C.; Deschamps, P.; Lauriol, B.

    2009-05-01

    The chronology of Arctic terrestrial environments is poorly documented due to the scarcity of representative deposits allowing radiometric age determinations. Endostromatolites are secondary carbonate precipitations filling fractures in karstic carbonate terrains found in various sites in Yukon, North-West Territories. Expectations about their use to document environmental change were high. The specimens studied here originate from the Bear Cave Mountains (Yukon). They fill presently unsaturated fissures along cliffs, above karstic formations, within a few meters from the bedrock surface. They occur on southern oriented surfaces, and systematically develop on the outer side surface of the fractures. These concretions are likely of biogenic origin, and are thought to form during periods with relatively warm conditions in the Arctic (i.e., maximum insolation intervals). We report here on 238U, 234U, 230Th, 226Ra, 14C, 13C and 18O analyses of a few thick specimens (2 cm). A first sample yielded inconsistent 14C- and 230Th-ages (ranging from bottom to top of the concretion10-4 ka and 260-55 ka, respectively). Higher resolution measurements in a second sample better illustrate trends from the layer immediately attached to the host rock (here Paleozoic limestone) and the outer, columnar surface of the concretion: i) 230Th/238U activity ratio decrease from near secular equilibrium values to appr. 0.2; ii) 238U- concentrations increase from ~ 2 to ~ 6 ppm, and iii) 226Ra/230Th activity ratios increase from near secular equilibrium values to 1.2. This pattern suggest a pseudo-Rayleigh fractionation process with redistribution of U-series isotopes from the host-rock into the calcrete growth layers, more or less in function of their relative solubility. Some addition of more soluble elements relating to water fluxes cannot be ruled out. Stable carbon isotopes suggest a similar process with a progressive enrichment in 13C (up to +8.5 vs. VPDB) attributed to kinetic fractionation with freezing of water inducing outgazing of an isotopically light CO2 with precipitation of a 13C-enriched calcite. The trend for a progressive enrichment in 14C suggests partial exchanges with the atmospheric CO2 circulating in bedrock fissures. Thus, if 14C and U-series methods cannot be used to set the age of such calcrete, they provide information on their accretion process. In view of the excess 226Ra observed throughout most of the concretion, the overall age of the study specimen cannot exceed a few thousand years (i.e., mid- to late-Holocene), but one cannot estimate any precise duration for the growth phase within this interval. Both their stable isotope properties and complex age structure made them unsuitable for precise paleoclimate reconstructions but allow inferences about the presence of seasonal/occasional active layer above the permafrost during their growth stages.

  5. Radiogenic and U-series isotopes in very low sedimentation rate sediments from Mendeleev Ridge (Arctic Ocean): sources, mineral carriers and stratigraphic implications

    NASA Astrophysics Data System (ADS)

    Hillaire-Marcel, C.; Darby, D.; Francois, R.; Helie, J.; Lamziouaq, R.; Not, C.; Polyak, L.; Preda, M.; Satte, Y. M.; Stevenson, R.

    2007-12-01

    Sedimentological and geochemical properties, U-series isotopes, radiogenic isotopes and anthropogenic radionuclides contents were determined on two cores from the Mendeleev Ridge. Excesses in 210Pb over 226Ra activities are observed down to 1.25 cm from core-tops, due to shallow mixing by benthic organisms. Below, 210Pb-activity follows 226Ra-activity in turn controlled by parent 230Th-excess fluctuations in the sediment, except for some 226Ra-diffusion towards the water column from core-top and on both sides of 230Thxs peaks below. Thus, estimating 210Pb-excess requires precise knowledge of 226Ra-supported fraction, i.e., of 230Th- excess and Ra-diffusion. Both cores depict identical grain size, mineralogical, geochemical and isotopic distributions, despite bathymetric difference. This suggests negligible impact of bottom currents, limited scavenging of heavy metals in the lower water column, and a net export of particle reactive U-daughter isotopes (Th, Pa, Pb) produced from the overlying water column. Peaks in 230Thxs and 231Paxs (0-7cm, 17 cm and 30 cm sub-bottom) match high contents in clays and fine carbonates (primarily dolomite), and likely indicate interglacial/interstadial conditions and/or occurrence of turbidity events (e.g., during deglaciations). These peaks correspond to maximum illite supplies, minimum Sr-isotope ratios and epsilon-Nd values in the -10 to -12 range. Interlayered sediments, with high sand but low carbonate contents, minimum clay fluxes (low illite relative contents), minimum 230Th and 231Pa excesses, maximum Sr-isotope ratios, possibly indicate full glacial conditions and significantly reduced sedimentation rates.

  6. Early diagenesis impact on precise U-series dating of deep-sea corals: Example of a 100–200-year old Lophelia pertusa sample from the northeast Atlantic

    Microsoft Academic Search

    Edwige Pons-Branchu; Claude Hillaire-Marcel; Pierre Deschamps; Bassam Ghaleb; Daniel J. Sinclair

    2005-01-01

    Deep-sea coral has proved useful for paleoceanographic reconstructions and for documenting 14C-ages of water masses using 230Th-ages. However, for precise and accurate U-series dating, further information on coral-age structure, growth rate and diagenetic evolution is still needed. To document such processes, we used U-Th-226Ra systematics in a 40 cm diameter, Lophelia pertusa specimen collected in 1912 from the Eastern Atlantic

  7. Preboreal onset of cold-water coral growth beyond the Arctic Circle revealed by coupled radiocarbon and U-series dating and neodymium isotopes

    NASA Astrophysics Data System (ADS)

    López Correa, M.; Montagna, P.; Joseph, N.; Rüggeberg, A.; Fietzke, J.; Flögel, S.; Dorschel, B.; Goldstein, S. L.; Wheeler, A.; Freiwald, A.

    2012-02-01

    Cold-water coral mounds of Lophelia pertusa are widespread across the Scandinavian shelf, which was completely ice-covered during the Last Glacial Maximum between 22 to 18 ka BP. Rapid deglacial meltdown of the Fennoscandian inland ice and the retreat of its ice-streams freed most of the shelf of ice by ˜15 ka BP. However, cold-water coral growth commenced only after the Pleistocene-Holocene transition at 11.65 ka BP, when modern-like climatic patterns and oceanographic conditions were established. A tight climatic coupling has been constrained with U-series ages. Coupled 14C ages provide local reservoir ages from various gravity cores in a fjord-setting in Stjernsund at 70°N and on the open shelf in Trænadjupet at 66°N. Reinvestigation of earlier 14C coral chronologies suggests that coral ecosystems widely established themselves across the entire 3000 km long Scandinavian shelf prior to ˜10 ka BP. The earliest occurrence of Madrepora oculata at ˜2.4 ka BP suggests a late Holocene colonization of the Norwegian shelf, which is linked to a prominent mound growth hiatus in Trænadjupet (64°N). Mound growth rates near the northern biogeographic boundary of L. pertusa with up to ˜614 cm ka-1 during certain growth periods are much higher than the previously reported fastest rates of ˜220 cm ka-1 from the Irish margin. Contemporaneous rapid fjordbasin sedimentation is slower with ˜63 cm ka-1. Matrix 14C ages overlap with coral 14C ages from the same horizon. This indicates rapid framework construction and efficient trapping of background sediment. Hiatuses are frequent in on-mound sediments and only short periods of coral growth are recorded. Coupled ?14C and ?Nd values indicate a persistent Holocene inflow of the North Atlantic Current in Stjernsund, but also deglacial meltwater mixing during the early Holocene prior to ˜9.5 ka BP. Reservoir ages are overall close to the surface marine reservoir age, but ?R is highly localized.

  8. Giant radioactive halos: indicators of unknown radioactivity?

    PubMed

    Gentry, R V

    1970-08-14

    A new group of giant radioactive halos has been found with radii in excess of anything previously discovered. Since alternate explanations for these giant halos are inconclusive at present, the possibility is considered that they originate with unknown alpha radioactivity, either from isomers of known elements or from superheavy elements. PMID:17791843

  9. Procedures for radioactive I-131

    SciTech Connect

    Sharma, S.C. (Univ. of Louisville, KY (USA))

    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.

  10. Radioactivity distribution in some Permian sediments from the Iratí and Corumbataí Formations of the Paraná Basin, Southeastern Brazil.

    PubMed

    Carlos, Dionísio Uendro; Ribeiro, Fernando Brenha; Saad, Antonio Roberto; Nicolai, Silvia Helena de Araújo

    2004-01-01

    In the city of Limeira, southeastern Brazil, an important exposure of Permian sediments of the Paraná basin was revealed by an open pit mine that exploits limestone for production of soil correction compounds and raw materials for the ceramic industry. The radioactivity of these sediments was investigated in some detail and the results provided a general view of the vertical distributions of uranium, thorium and potassium concentrations and of the element ratios U/K, U/Th and Th/K. In general, the concentrations of the main natural radioactive elements are low, with uranium being enriched in some limestone and shale levels. In addition the results showed that the 238U series is in radioactive disequilibrium in many of the analyzed samples. Although the origin of the observed disequilibrium has not been investigated, the results suggest that it is due to weathering processes and water interaction with the rock matrix. PMID:14687638

  11. Radioactive Counting Clocks

    Microsoft Academic Search

    Shankar Radhakrishnan; Amit Lal

    2006-01-01

    We report on a radioactive counting clock (RCC) based on radioactive beta emissions from nickel-63 thin films. We present a theoretical analysis of the clock that uses the radioactive source (physics package) to lock and stabilize the frequency of a voltage-to-frequency converter (local oscillator). We present frequency stability measurements of the RCC over 10 days of clock operation. We analyze

  12. Radioactivity and food

    SciTech Connect

    Olszyna-Marzys, A.E. (Laboratorio Unificado de Control de Alimentos y Medicamentos (LUCAM) (Guatemala))

    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.

  13. 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.

  14. New heavy proton radioactivities

    SciTech Connect

    Davids, C.N. [Argonne National Lab., IL (United States); Woods, P.J. [Edinburgh Univ. (United Kingdom); Batchelder, J.C. [Louisiana State Univ., Baton Rouge, LA (United States)] [and others

    1995-08-01

    The new proton radioactivities {sup 165,166,167}Ir, {sup 171}Au, and {sup 185}Bi have been observed, extending our knowledge of proton radioactivity up to and beyond the Z=82 closed shell. For Z=77 and 79, the transitions can be explained using simple shell-model arguments. The case of {sup 185}Bi represents the first example of proton radioactivity from an intruder state.

  15. 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.

  16. Radioactive waste storage issues

    Microsoft Academic Search

    Kunz

    1994-01-01

    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

  17. Biodegradation of radioactive animals

    Microsoft Academic Search

    Nicolas Party; Esmeralda Party; Amy Wilkerson; Edward L. Gershey

    1995-01-01

    The two most common disposal alternatives for animals contaminated with radioactive materials are incineration and burial. For most of the country burial has entailed shipping the carcasses to a commercial disposal facility at Barnwell, South Carolina, where it was landfilled along with other solid radioactive waste. Unfortunately, since 30 June 1994, this facility accepts waste generated by the states of

  18. 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…

  19. 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.

  20. 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)

  1. 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.

  2. Radioactive Decay Calculator

    NSDL National Science Digital Library

    Alan Enns

    This online calculator computes radioactive decay, timed decay, and timed solid disposal for a databank containing 116 isotopes. It also features University of British Columbia disposal limits and a unit converter and date/time calculators. These tools calculate the half-life for selected isotopes; radioactive decay final activity, given the initial activity and decay time; the decay time, given the initial and final activities; and the decay time, given the mass of a solid and the initial activity.

  3. Biodegradation of radioactive animals

    SciTech Connect

    Party, N.; Party, E.; Wilkerson, A. [Rockefeller Univ., NY (United States)] [and others

    1995-06-01

    The two most common disposal alternatives for animals contaminated with radioactive materials are incineration and burial. For most of the country burial has entailed shipping the carcasses to a commercial disposal facility at Barnwell, South Carolina, where it was landfilled along with other solid radioactive waste. Unfortunately, since 30 June 1994, this facility accepts waste generated by the states of the Southeast Compact only. Therefore, burial is no longer an option for most of the country`s generators and incineration is an option only for those institutions which have, or have access to, an incinerator that is permitted to burn radioactive materials and that accepts animal carcasses with de minimis levels of radioactive contaminants. Many institutions, especially those in congested urban areas where the public does not support incineration, do not have viable outlets for radioactive animal carcasses. Interim, on-site storage poses problems of its own. Biodegradation of animal carcasses with dermestid beetles is an inexpensive approach to this waste management problem. 7 refs., 3 figs., 1 tab.

  4. Biodegradation of radioactive animals.

    PubMed

    Party, N; Party, E; Wilkerson, A; Gershey, E L

    1995-06-01

    The two most common disposal alternatives for animals contaminated with radioactive materials are incineration and burial. For most of the country burial has entailed shipping the carcasses to a commercial disposal facility at Barnwell, South Carolina, where it was landfilled along with other solid radioactive waste. Unfortunately, since 30 June 1994, this facility accepts waste generated by the states of the Southeast Compact only. Therefore, burial is no longer an option for most of the country's generators and incineration is an option only for those institutions which have, or have access to, an incinerator that is permitted to burn radioactive materials and that accepts animal carcasses with de minimis levels of radioactive contaminants. Many institutions, especially those in congested urban areas where the public does not support incineration, do not have viable outlets for radioactive animal carcasses. Interim, on-site storage poses problems of its own. Biodegradation of animal carcasses with dermestid beetles is an inexpensive approach to this waste management problem. PMID:7759267

  5. 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.

  6. 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.

  7. New Proton Radioactivity Measurements

    E-print Network

    Edinburgh, University of

    New Proton Radioactivity Measurements Richard J. Irvine Thesis submitted for the degree of Doctor to search for examples of proton emission from ground and low­lying states in odd­Z nuclei at the proton into a double­sided silicon strip detector system, where their subsequent particle decays (proton or alpha) were

  8. 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.

  9. Radioactivity and foods

    SciTech Connect

    Olszyna-Marzys, A.E. (Unified Lab. of Food and Drug Control, Guatemala City (Guatemala))

    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.

  10. RADIOACTIVE MATERIALS SENSORS

    Microsoft Academic Search

    Robert M. Mayo; Daniel L. Stephens

    2009-01-01

    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

  11. [Radioactivity of bone cement].

    PubMed

    Scherer, M A; Winkler, R; Ascherl, R; Lenz, E

    1993-01-01

    A total of 14 samples of different types of bone cement from five different manufacturers were examined for their radioactivity. Each of the investigated bone cements showed a low radioactivity level, i.e. between < 1 and 100 Bq/kg. The content of U-238 and K-40 always was below the limit of detection (< 1-< 10 Bq/kg). Significant differences were detected in the amount of Ra-226, Pb-210, and Ra-228 detected between different samples of the same product from the same manufacturer, as well as between various types of cements. The highest radioactivity level was measured for Ra-226. Although stochastic radiation effects can not totally be excluded, it is extremely unlikely that the small amount of radioactive substances additionally transferred into the body by the bone cement has negative effects on the recipient's organism or on the fate of the alloplastic implant: "The risk factor and extrapolation in a low dosage range ... do not lead to an underestimation but more likely to an overestimation of the radiation hazard" [18]. PMID:8441806

  12. NATURAL RADIOACTIVE ELEMENTS IN PLANTS

    Microsoft Academic Search

    Kovalevskii

    1962-01-01

    Selective absorption of Ra, U, and Th isotopes by plants and the ; radioactive equilibrium of Ha isotopes and their decay products were studied. ; The accumulation of U, Ha, and other rare-earth elements by plants is determined ; by chemical rather than radioactive properties. In spite of the fact that the ; number of BETA decays from natural radioactive

  13. Fusion reactor radioactive waste management

    Microsoft Academic Search

    J. D. Kaser; A. K. Postma; D. J. Bradley

    1976-01-01

    Quantities and compositions of non-tritium radioactive waste are estimated for some current conceptual fusion reactor designs, and disposal of large amounts of radioactive waste appears necessary. Although the initial radioactivity of fusion reactor and fission reactor wastes are comparable, the radionuclides in fusion reactor wastes are less hazardous and have shorter half-lives. Areas requiring further research are discussed.

  14. 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

    Microsoft Academic Search

    Lewis A. Owena; Jordon Brightb; Robert C. Finkelc; Manoj K. Jaiswald; Darrell S. Kaufmanb; Shannon Mahane; Ulrich Radtkef; Joan S. Schneiderg; Warren Sharph; Ashok K. Singhvid; Claude N. Warreni

    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

  15. Investigation of aerial dispersion of radioactive dust from an open-pit uranium mine by passive vinyl collectors

    SciTech Connect

    Pettersson, H.B.; Koperski, J. (Lund Univ. Teaching Hospital (Sweden))

    1991-05-01

    Detailed investigations of the aerial dispersion of radioactive dust from the biggest open-pit U mining and milling operation in Australia were carried out. Spatial distributions of the long-lived radionuclides of {sup 238}U series and their origin, i.e., mining and milling operations vs. natural background radiation, have been studied. Horizontal flux, dry deposition, and ground resuspension of the radionuclides were investigated along a 50-km transect in the direction of the prevailing monsoonal winds in the region. The study was performed by means of unconventional 'sticky vinyl' passive dust collectors, occasionally supported by high-volume air filter samplers. The data from the flux measurements show an inverse square to inverse cubic dependence, and the dry deposition exhibits an inverse square dependence, of radionuclide load vs. distance. The pit has been the predominant contributor of long-lived U series radionuclides to the environment within the radius of several kilometers from the operations. An aerial dispersion computer code (LUCIFER), based on a Gaussian plume model, was developed for the project. Experimental data were used as the code input data. Good agreement between the measured data and the normalized computed results was obtained.

  16. Investigation of aerial dispersion of radioactive dust from an open-pit uranium mine by passive vinyl collectors.

    PubMed

    Pettersson, H B; Koperski, J

    1991-05-01

    Detailed investigations of the aerial dispersion of radioactive dust from the biggest open-pit U mining and milling operation in Australia were carried out. Spatial distributions of the long-lived radionuclides of 238U series and their origin, i.e., mining and milling operations vs. natural background radiation, have been studied. Horizontal flux, dry deposition, and ground resuspension of the radionuclides were investigated along a 50-km transect in the direction of the prevailing monsoonal winds in the region. The study was performed by means of unconventional "sticky vinyl" passive dust collectors, occasionally supported by high-volume air filter samplers. The data from the flux measurements show an inverse square to inverse cubic dependence, and the dry deposition exhibits an inverse square dependence, of radionuclide load vs. distance. The pit has been the predominant contributor of long-lived U series radionuclides to the environment within the radius of several kilometers from the operations. An aerial dispersion computer code (LUCIFER), based on a Gaussian plume model, was developed for the project. Experimental data were used as the code input data. Good agreement between the measured data and the normalized computed results was obtained. PMID:2019500

  17. Fluid/rock Interaction History of a Faulted Rhyolite-Granite Contact Determined by Sr- Pb-Isotopes, Th/U-Disequilibria and Elemental Distributions (Eastern Rhine Graben Shoulder, SW-Germany)

    NASA Astrophysics Data System (ADS)

    Marbach, T.; Mangini, A.; Kober, B.; Schleicher, A.; Warr, L. N.

    2003-04-01

    Major and trace element analyses allow to obtain information concerning the chemical changes induced by alteration. Differences are partly petrographic because the profile crosses the granite-rhyolite contact, but they are also due to different alteration levels induced by fluid circulation along the fault system which has drained the alteration processes. The granite-rhyolite contact constitutes the primary structure. Only the most incompatible elements (Si, Al, Zr, Hf) retain their original signatures and reflect a mixing between typical granite and rhyolite lithologies across the altered zones (cataclasite). The more mobile elements show a different composition within the altered zones (cataclasite) notably a high leaching of cations. The geochemical tracers also suggest at least one strong hydrothermal event with reducing conditions in the altered zones. The isotopic analyses delivered qualitative and temporal information. The use of several isotopic systems, Rb/Sr-, U/Pb-isotopes and Th/U disequilibria, reveals a complex history of polyphase fluid/rock interaction following the Permian volcanic extrusion, showing notable disturbances during the late Jurassic hydrothermal activities, the Tertiary rifting of the Rhine Graben and more recent Quaternary alteration. The granite zone of the sampling profile has underwent an event which set up a new Rb-Sr isotopic composition and reset the Rb/Sr system which originatly corresponded to the Carboniferous intrusion ages. The Rb-Sr data of the granite samples produce a whole rock isochron of 152 ± 5,7 Ma (2? error) in good agreement with the well-known late Jurassic hydrothermal event (135--160 Ma). The rocks evolution lines for Pb support a Tertiary hydrothermal event (54 Ma ± 16; 1? error), potentially connected with the development of the Rhine Graben. The profile samples have undergone uranium and thorium redistribution processes which have occurred within the last ˜10^6 years. The samples of the altered zones record a more complex history of uranium exchange with the aqueous phase. This uranium exchange is proportional to the porosity. The best approximation is reached for an exchange coefficient (?_E) for uranium ranging from 2,5 E-06 [a-1] in the middle of the altered zones to 2,5 E-05 [a-1] on the sides of the altered zones.

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

    Microsoft Academic Search

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

    2003-01-01

    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

  19. Table of radioactive elements

    NASA Astrophysics Data System (ADS)

    Holden, N. E.

    As has been the custom in the past, the Commission publishes a table of relative atomic masses and half-lives 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 half-lives have already been documented.

  20. 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.

  1. 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

  2. Radiological impacts of natural radioactivity in Abu-Tartor phosphate deposits, Egypt.

    PubMed

    Khater, A E; Higgy, R H; Pimpl, M

    2001-01-01

    Phosphate and environmental samples were collected from Abu Tartor phosphate mine and the surrounding region. The activity concentration of 226Ra (238U) series, 232Th series and 40K were measured using a gamma-ray spectrometer. The activities of uranium isotopes (238U, 235U and 234U) and 210Pb were measured using an alpha spectrometer and a low-background proportional gas counting system, respectively, after radiochemical separation. The results are discussed and compared with the levels in phosphate rocks from different countries. It seems that the Abu Tartor phosphate deposit has the lowest radioactivity level of exploited phosphate of sedimentary origin. 226Ra/238U, 210Pb/226Ra, 234U/238U and 226Ra/228Ra activity ratios were calculated and are discussed. The radioactivity levels in the surrounding region and the calculated exposure dose (nGy/h) will be considered as a pre-operational baseline to estimate the possible radiological impacts due to mining, processing and future phosphate industrial activities. To minimize these impacts, the processing wastes should be recycled to the greatest possible extent. PMID:11430674

  3. 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.

  4. 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.

  5. Simpler radioactive wastewater processing.

    PubMed

    Rodríguez, José Canga; Luh, Volker

    2011-11-01

    José Canga Rodríguez, key account manager, Pharmaceutical and Life Sciences, EnviroChemie, and Volker Luh, CEO of EnviroDTS, describe the development, and recent successful application, of a new technology for dealing safely and effectively with the radioactive "wastewater" generated by patients who have undergone radiotherapy in nuclear medicine facilities. The BioChroma process provides what is reportedly not only a more flexible means than traditional "delay and decay" systems of dealing with this "by-product" of medical treatment, but also one that requires less plant space, affords less risk of leakage or cross-contamination, and is easier to install. PMID:22368885

  6. 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.

  7. Radioactive Sources in Chemical Laboratories

    Microsoft Academic Search

    Helena Jan

    Radioactive sources including all radioactive materials exceeding exemption levels have to be registered in national databases according to international standards based on the recommendations ICRP 60 and a proper licensing should take place as described for example in the 96\\/29\\/EURATOM. In spite of that, unregistered sources could be found, usually due to the fact that the owner is not aware

  8. Radioactive waste disposal classification system

    Microsoft Academic Search

    1979-01-01

    The Nuclear Regulatory Commission, as part of its development of regulations for the disposal of radioactive waste, has contracted for the development of a radioactive waste classification system. The need for removing the waste from man's environment increases as the potential for endangering the health and safety of the public increases. The classification system being proposed is based on the

  9. 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.

  10. Radioactivity in nuclear medicine

    SciTech Connect

    Wolf, A.P. [Brookhaven National Lab., Upton, NY (United States)

    1996-10-01

    The use of radioactivity in biomedical research probably goes back to the efforts of George von Hevesy and his concept of the tag(tracer). The first use of a tracer in humans was perhaps the work of H. Blumgart in 1927 when he used a solution of radon to trace the human bloodstream. In the mid 1930`s Robley Evans (MIT) suggested using {open_quotes}radioiodine{close_quotes} as a tracer in thyroid disease. From that point on radionuclides weir, firmly entrenched in medicine and biomedical research. At first iodine-128 was used, then iodine-131. In 1938 Segre and Seaborg described the discovery of Technetium-99m, the isotope which in later years would account for the major use in nuclear medicine practice. In 1946, the AEC issued its now classic list of radioisotopes for use in the scientific community. The age of the reactor had begun bringing about a revolution in one area of medical practice. The accelerator started coming back into favor in the 1950s but began to hit its stride in the 1960s and beyond, principally with making available iodine-123, thallium-201 and the positron emitters carbon-11, nitrogen-13, oxygen-15 and fluorine-18. The history of radiochemistry, chemistry and uses of these and the number of other important radionuclides will be discussed.

  11. 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.

  12. Consumer Products Containing Radioactive Materials

    MedlinePLUS

    ... require that these devices be registered or licensed. Granite Countertops Granite can release the radioactive gas radon into the ... released can vary considerably from one type of granite to another, the radon concentrations in most kitchens ...

  13. 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.

  14. Solubility data in radioactive waste disposal

    Microsoft Academic Search

    Hans Wanner

    2007-01-01

    Radioactive waste arises mainly from the generation of nuclear power but also from the use of radioactive materials in medicine, industry, and research. It occurs in a variety of forms and may range from slightly to highly radioactive. It is a worldwide consensus that radioactive waste should be disposed of in a permanent way which ensures protection of hu- mans

  15. 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.

  16. Storage containers for radioactive material

    DOEpatents

    Groh, E.F.; Cassidy, D.A.; Dates, L.R.

    1980-07-31

    A radioactive material storage system is claimed 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. The plate and the cover and the clamp cooperate to provide a storage area for radioactive material readily accessible for use or inventory. Wall mounts are provided to prevent accidental formation of critical masses during storage.

  17. Radioactive preionization in space lasers

    NASA Astrophysics Data System (ADS)

    Pereira, N. R.

    1984-10-01

    Radioactive preionization may have advantages over X-ray or UV preionization when simplicity, power consumption, and weight are at a premium, as in space lasers. Computations show that a few Ci/sq cm of Sr-90 in the laser sidewalls or the electrodes results in a homogeneous electron-source strength exceeding 10 to the 14th/cu cm sec.

  18. Radioactive waste: Politics and technology

    SciTech Connect

    Berkhout, F.

    1995-08-01

    This book presents an analysis of the divergent strategies used to forge radioactive waste policies in great Britain, Germany, and Sweden. Some basic knowledge of nuclear technology and its public policy development is needed. The book points out that developing institutional frameworks that permit agreement and consent is the principal challenge of radwaste management and places the problem of consent in an institutional framework.

  19. Radioactivity in bottled mineral waters

    Microsoft Academic Search

    A Mart??n Sánchez; M. P Rubio Montero; V Gómez Escobar; M Jurado Vargas

    1999-01-01

    Consumption of bottled mineral water is a growing practice and is sometimes a necessity rather than a choice. In this work, a study of the radioactive content of a wide selection of commercial bottled mineral waters for human intake was carried out. The origins of the analyzed waters were very different, coming from various locations in France, Portugal and Spain.

  20. Undiagnosed Illnesses and Radioactive Warfare

    Microsoft Academic Search

    Asaf Durakoviæ

    The internal contamination with depleted uranium (DU) isotopes was detected in British, Canadian, and United States Gulf War veterans as late as nine years after inhalational exposure to radioactive dust in the Persian Gulf War I. DU iso- topes were also identified in a Canadian veteran's autopsy samples of lung, liver, kidney, and bone. In soil samples from Kosovo, hundreds

  1. Electrodynamic radioactivity detector for microparticles

    NASA Astrophysics Data System (ADS)

    Ward, T. L.; Davis, E. J.; Jenkins, R. W., Jr.; McRae, D. D.

    1989-03-01

    A new technique for the measurement of the radioactive decay of single microparticles has been demonstrated. Although the experiments were made with droplets of order 20 ?m in diameter, microparticles in the range 0.1-100 ?m can be accommodated. An electrodynamic balance and combination light-scattering photometer were used to measure the charge-loss rate and size of a charged microsphere suspended in a laser beam by superposed ac and dc electrical fields. The charged particle undergoes charge loss in the partially ionized gas atmosphere which results from radioactive decay of 14C-tagged compounds, and the rate of charge loss is proportional to the rate of decay here. The charge on a particle was determined by measuring the dc voltage necessary to stably suspend the particle against gravity while simultaneously determining the droplet size by light-scattering techniques. The parameters which affect the operation of the electrodynamic balance as a radioactivity detector are examined, and the limits of its sensitivity are explored. Radioactivity levels as low as 120 pCi have been measured, and it appears that by reducing the background contamination inside our balance activity levels on the order of 10 pCi can be detected. This new technique has application in the measurement of activity levels and source discrimination of natural and man-made aerosols and smokes and is also useful for studies involving specifically labeled radio-chemical probes.

  2. Life cycle management of radioactive materials packaging

    Microsoft Academic Search

    Y. Liu; S. Bellamy; J. Shuler

    2007-01-01

    The objective of life cycle management of radioactive materials packaging is to ensure the safety functions (i.e. containment of radioactivity, protection against radiation, and criticality safety for fissile contents) during the entire life cycle of the packaging in storage, transportation and disposal. A framework has been developed for life cycle management regarding type B radioactive and fissile materials packaging, drawing

  3. Potential impacts of pending residual radioactivity rules

    Microsoft Academic Search

    1995-01-01

    The purpose of this paper is to present an overview of pending rules governing residual radioactive release criteria and radioactive waste management, and the potential impact of these rules on the Fernald Scrap Metal program. More than 300,000 cubic meters of radioactively contaminated waste will be generated during the dismantlement of three complexes at the Fernald Site over the next

  4. On the production of radioactive stents.

    PubMed

    Fehsenfeld, P; Golombeck, M; Kleinrahm, A; Schlösser, K; Schüssler, B; Schweickert, H; Hehrlein, C

    1998-01-01

    In the last few years, radioactive stents has been proved to inhibit neointima formation. This paper describes the actual status of producing such radioactive stents. After a short discussion of the different radioisotopes suitable for radioactive stents, potential production methods are discussed. The ion beam implantation of P-32 applied at the Karlsruhe Research Centre shall be described in more detail. PMID:10406687

  5. Radioactive isotopes in Danish drinking water

    E-print Network

    Radioactive isotopes in Danish drinking water Sven P. Nielsen Risø National Laboratory Working OF INVESTIGATION 11 3 DESCRIPTION OF INVESTIGATION 12 4 RADIOACTIVITY IN DRINKING WATER 13 5 SAMPLING 15 6 27 #12;4 #12;5 Preface This project for investigation of radioactivity in drinking water shall

  6. Charge distributions and coagulation of radioactive aerosols

    Microsoft Academic Search

    C. F. Clement; R. A. Clement; R. G. Harrison

    1995-01-01

    The self-charging of radioactive aerosols will be reduced by background ions, such as those produced by radioactive gases. The sources of these background ions and their production rates are specified for a reactor containment atmosphere during a possible nuclear accident. Previous theory is extended to calculate the charging of a polydisperse radioactive aerosol. Gaussian approximations to charge distributions on an

  7. On the production of radioactive stents

    NASA Astrophysics Data System (ADS)

    Schlösser, K.; Schweickert, H.

    2001-07-01

    In the last years radioactive stents proved to inhibit neointima formation. This paper describes the actual status of producing such radioactive stents. After a short discussion of the different radioisotopes suitable for radioactive stents, potential production methods are discussed. The ion beam implantation of P-32 applied at the Karlsruhe Research Center shall be described in more detail.

  8. Laboratory Surveys when Working with Radioactive Materials

    E-print Network

    Jia, Songtao

    Laboratory Surveys when Working with Radioactive Materials Procedure: 7.546 Created: 9 be surveyed every month in which radioactive materials in unsealed for are used. B. Applicability to order, use and store radioactive materials. D. Procedures 1. General Procedures Monthly surveys

  9. The standardization of radioactive preparations

    Microsoft Academic Search

    K. K. Aglintsev; F. M. Karavaev; A. A. Konstantinov; G. P. Ostromukhova; E. A. Kholnova

    1956-01-01

    The article describes methods and apparatus used in the D. L Mendeleev All-Union Scientific Research Institute of M etrology for the accurate measurement of a number of dosimetric characteristics of radioactive preparations: activity (calorimetric and ionization methods and the method of absolute B-counting), y-equivalent (ionization chamber With 4~r solid angle), and the magnitude of the dose of y-radiation (normal lont.zatJon

  10. 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.

  11. 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.

  12. About radioactivity in some PMMA bone cements.

    PubMed

    Hopf, W; Hopf, C G; Glöbel, B

    1990-01-01

    Various bone cements containing zirconium oxide (ZrO2) as X-ray contrast medium were tested for radioactivity by means of a gamma spectrometer. All measured bone cements (PALACOS, IMPLAST, SULFIX-6) showed a certain degree of radioactivity. The radiation source in the bone cement is the added zirconium oxide, which is polluted by radioactive elements. As these X-ray contrast media remain in the body for decades as components of the bone cement, the radioactive zirconium oxides should be substituted by high purity radiation-free zirconium oxide or barium sulfate. PMID:2239190

  13. 30. Radioactivity and radiation protection 1 30. RADIOACTIVITY AND RADIATION PROTECTION

    E-print Network

    30. Radioactivity and radiation protection 1 30. RADIOACTIVITY AND RADIATION PROTECTION Revised for the 2012 edition (pdg.lbl.gov) February 16, 2012 14:08 #12;2 30. Radioactivity and radiation protection radiation in a volume element of a specified material divided by the mass of this volume element. · Kerma, K

  14. 33. Radioactivity and radiation protection 1 33. RADIOACTIVITY AND RADIATION PROTECTION

    E-print Network

    33. Radioactivity and radiation protection 1 33. RADIOACTIVITY AND RADIATION PROTECTION Revised://pdg.lbl.gov) June 18, 2012 16:20 #12;2 33. Radioactivity and radiation protection tissue caused by different radiation in a volume element of a specified material divided by the mass of this volume element. · Kerma, K

  15. 30. Radioactivity and radiation protection 1 30. RADIOACTIVITY AND RADIATION PROTECTION

    E-print Network

    30. Radioactivity and radiation protection 1 30. RADIOACTIVITY AND RADIATION PROTECTION Revised;2 30. Radioactivity and radiation protection caused by different radiation types R weighted with so radiation in a volume element of a specified material divided by the mass of this volume element. · Kerma, K

  16. 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 ...

  17. 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.

  18. 300 Area radioactive liquid waste streams disposal

    Microsoft Academic Search

    Clukey

    1954-01-01

    In the 300 Area there are three liquid waste streams containing low concentrations of radioactive material which are discharged into the ground. One of these is the process sewer stream from the Metal Preparations facility, the 321 Building Cold Separations Laboratory, and miscellaneous buildings where minor radioactive contamination might occur. The second stream is liquid waste of low or negligible

  19. Pb-Radioactivity in superheavy elements

    E-print Network

    Kumar, Sushil

    2011-01-01

    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.

  20. Natural radioactivity in Italian ceramic tiles

    Microsoft Academic Search

    S. Righi; A. Albertazzi; R. Guerra; M. Jeyapandian; S. Verità

    2009-01-01

    and, therefore, reference is often made to radium instead of uranium (EC, 1999). The knowledge of the natural radioactivity of building materials is important for the determination of population exposure to radiations, as most of the people spend ~80% of their time indoors (UNSCEAR, 1993). High levels of radioactivity in construction materials can increase external and internal indoor exposure. Currently,

  1. Feasibility analysis of recycling radioactive scrap steel

    Microsoft Academic Search

    F. Nichols; B. Balhiser; N. Cignetti

    1995-01-01

    The purpose of this study is to: (1) establish a conceptual design that integrates commercial steel mill technology with radioactive scrap metal (RSM) processing to produce carbon and stainless steel sheet and plate at a grade suitable for fabricating into radioactive waste containers; (2) determine the economic feasibility of building a micro-mill in the Western US to process 30,000 tons

  2. Keynote lecture IRPA 12 Radioactive Waste Management

    Microsoft Academic Search

    Jean-Christophe NIEL

    A common property of radioactive waste is that it presents a hazard to human health and the environment. Then, it must be managed in order to reduce risks to acceptable levels. The preferred strategy for the management of all radioactive waste is to contain it and isolate it from the accessible biosphere during its decay. However, the controlled discharge of

  3. Guide to radioactive waste management literature

    Microsoft Academic Search

    B. L. Houser; C. F. Holoway; D. G. Madewell

    1977-01-01

    Increased public concern about radioactive waste management has called attention to this aspect of the nuclear fuel cycle. Socio-economic planning and technical development are being undertaken to assure that such wastes will be managed safely. This Guide to Radioactive Waste Management Literature has been compiled to serve scientists, engineers, administrators, legislators, and private citizens by directing them to sources of

  4. Radioactivity of the moon and planets

    Microsoft Academic Search

    Iu. A. Surkov

    1981-01-01

    The major results of studies of the radioactivity of the moon and terrestrial planets are reviewed. Measurements of the cosmogenic and natural radioactivity of the moon and Mars were obtained from planetary orbiter measurements, and those of Venus by in situ measurements, in addition to measurements of lunar samples brought back to earth. For the case of the moon, the

  5. 49 CFR 172.436 - RADIOACTIVE WHITE-I label.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ... 2011-10-01 false RADIOACTIVE WHITE-I label. 172.436 Section 172... Labeling § 172.436 RADIOACTIVE WHITE-I label. (a) Except for size and color, the RADIOACTIVE WHITE-I label must be as follows:...

  6. 49 CFR 172.436 - RADIOACTIVE WHITE-I label.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ... 2010-10-01 false RADIOACTIVE WHITE-I label. 172.436 Section 172... Labeling § 172.436 RADIOACTIVE WHITE-I label. (a) Except for size and color, the RADIOACTIVE WHITE-I label must be as follows:...

  7. 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...

  8. 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...

  9. 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...

  10. 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...

  11. 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...

  12. 10 CFR 835.1202 - Accountable sealed radioactive sources.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...containers, and devices. (b) Except for sealed radioactive sources consisting solely of gaseous radioactive material or tritium, each accountable sealed radioactive source shall be subject to a source leak test upon receipt, when damage is...

  13. 10 CFR 835.1202 - Accountable sealed radioactive sources.

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...containers, and devices. (b) Except for sealed radioactive sources consisting solely of gaseous radioactive material or tritium, each accountable sealed radioactive source shall be subject to a source leak test upon receipt, when damage is...

  14. 10 CFR 835.1202 - Accountable sealed radioactive sources.

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...containers, and devices. (b) Except for sealed radioactive sources consisting solely of gaseous radioactive material or tritium, each accountable sealed radioactive source shall be subject to a source leak test upon receipt, when damage is...

  15. 10 CFR 835.1202 - Accountable sealed radioactive sources.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...containers, and devices. (b) Except for sealed radioactive sources consisting solely of gaseous radioactive material or tritium, each accountable sealed radioactive source shall be subject to a source leak test upon receipt, when damage is...

  16. 10 CFR 835.1202 - Accountable sealed radioactive sources.

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...containers, and devices. (b) Except for sealed radioactive sources consisting solely of gaseous radioactive material or tritium, each accountable sealed radioactive source shall be subject to a source leak test upon receipt, when damage is...

  17. 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

  18. 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.

  19. 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.

  20. 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.

  1. 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.

  2. 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.

  3. Central Storage for Unsealed Radioactive Materials

    E-print Network

    Pawlowski, Wojtek

    Central Storage for Unsealed Radioactive Materials Radiation Safety Form PERMIT HOLDER NAME:______________________________ PHONE #: ____________________________ ADDRESS/DEPT.: _______________________________ Storage Location: Refrigerator Freezer Dry Storage List each item being transferred to storage separately: EH&S LAB WIPE SURVEY

  4. 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.

  5. Radioactively Contaminated National Priorities List (NPL) Sites

    MedlinePLUS

    ... SD UT WY [ regions ] Region 9 AZ · CA · HI · NV · AS · GU · TT · NI Trust Territories · Northern ... in Arizona go to: Region 9 : AZ CA HI NV AS GU [ regions ] [ previous location ] California Radioactively ...

  6. Using Popcorn to Simulate Radioactive Decay

    NSDL National Science Digital Library

    Jennifer Wenner

    Popping popcorn in your class is an excellent way to illustrate both the spontaneity and irreversible change associated with radioactive decay. It helps students to understand the unpredictability of decay.

  7. Operational experience at radioactive waste treatment plant, after 15 years

    Microsoft Academic Search

    Sanhueza-Mir; Azucena

    2007-01-01

    Available in abstract form only. Full text of publication follows: The experience of the radioactive waste treatment plant (PTDR) in Chile, which centralizes all activities related to pre-disposal activities in the radioactive waste management, in the country is presented. It is the solely waste treatment plant in the country, where radioactive waste are received from all nuclear and radioactive waste

  8. Radioactive Waste Management: a current awareness bulletin. [DOE abstract journal

    Microsoft Academic Search

    McLaren

    1983-01-01

    Management of radioactive wastes is necessary to protect public health, public safety, and the environment from radioactive materials resulting from national defense programs, energy research and development, and commercial activities. Access to information on the critical topics of spent fuel transport and storage, radioactive effluents from nuclear facilities, techniques of processing radioactive wastes, and ultimate disposal of the wastes is

  9. 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.

  10. Vitrification of hazardous and radioactive wastes

    SciTech Connect

    Bickford, D.F.; Schumacher, R.

    1995-12-31

    Vitrification offers many attractive waste stabilization options. Versatility of waste compositions, as well as the inherent durability of a glass waste form, have made vitrification the treatment of choice for high-level radioactive wastes. Adapting the technology to other hazardous and radioactive waste streams will provide an environmentally acceptable solution to many of the waste challenges that face the public today. This document reviews various types and technologies involved in vitrification.

  11. Low-level radioactive waste management

    Microsoft Academic Search

    1979-01-01

    This publication contains the proceedings of the Twelfth Mid-year Topical Symposium of the Health Physics Society on Low-Level Radioactive Waste Management held in Williamsburg, Virginia, February 11-15, 1979. There are fifty-seven papers included covering such topics on radioactive waste management as (1) the origin, (2) handling and transportation, (3) disposal operations and alternatives (4) regulatory aspects, (5) environmental, and (6)

  12. Salivary gland dysfunction following radioactive iodine therapy

    SciTech Connect

    Wiesenfeld, D.; Webster, G.; Cameron, F.; Ferguson, M.M.; MacFadyen, E.E.; MacFarlane, T.W.

    1983-02-01

    Radioactive iodine is used extensively for the treatment of thyrotoxicosis and thyroid carcinoma. Iodine is actively taken up by the salivary glands and, following its use, salivary dysfunction may result as a consequence of radiation damage. The literature is reviewed and a case is reported in which a patient presented with a significant increase in caries rate attributed to salivary dysfunction following radioactive iodine therapy for a thyroid carcinoma.

  13. 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.

  14. Environmental radioactivity in the Arctic, Antarctic

    SciTech Connect

    Palmer, H.

    1993-12-01

    This conference on radioactivity in the Arctic and Antarctic was held in Kirkenes, Norway and sponsored by the Norwegian Radiation Protection Authority and the Department of Radiation Physics, Sweden's University of Lund. Radioactivity in the Arctic is the result of both natural phenomena and human activities. Natural or background radioactivity is a result of the breakdown and erosion of rocks that contain naturally radioactive minerals. But the levels introduced by dumping, weapons testing, and industrial activities far exceed such natural levels. Conference delegates cited such contamination sources as: Chernobyl's nuclear reactor accident; Wastes from fuel reprocessing plants at Sellafield (UK) and La Hague (France); Weapons testing in and around Novaya Zemlya; Ocean dumping of reactors, waste containers, and liquid wastes; Runoff from watersheds containing soil and organic material contaminated by atmospheric fallout; Atmospheric fallout from decades of weapons tests by various nations; and, Accidents involving nuclear submarines. The potential for increased radioactive pollution is of great concern and these questions were addressed by several speakers.

  15. 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

  16. 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.

  17. Radioactive Waste Management in A Hospital

    PubMed Central

    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

  18. 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.

  19. Type A radioactive liquid sample packaging family

    SciTech Connect

    Edwards, W.S.

    1995-11-01

    Westinghouse Hanford Company (WHC) has developed two packagings that can be used to ship Type A quantities of radioactive liquids. WHC designed these packagings to take advantage of commercially available items where feasible to reduce the overall packaging cost. The Hedgehog packaging can ship up to one liter of Type A radioactive liquid with no shielding and 15 cm of distance between the liquid and the package exterior, or 30 ml of liquid with 3.8 cm of stainless steel shielding and 19 cm of distance between the liquid and the package exterior. The One Liter Shipper can ship up to one liter of Type A radioactive liquid that does not require shielding.

  20. Radioactive tank waste remediation focus area

    SciTech Connect

    NONE

    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.

  1. 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.

  2. Horizontal transmission rapidly erodes disequilibria between organelle and symbiont genomes.

    PubMed

    Brandvain, Yaniv; Goodnight, Charles; Wade, Michael J

    2011-09-01

    We investigate the generation and decay of interspecific disequilibrium (ID) between organelle and symbiont genomes as a function of the rate of horizontal transmission. We show that rare horizontal transmission greatly diminishes the covariance between organelle and symbiont genomes. This result has two important implications. First, a low level of ID does not indicate low levels of vertical transmission. Second, even with low levels of horizontal transmission, the additive effects of host and symbiont loci will determine the response to selection, while epistatic effects will not be selectable. PMID:21750254

  3. 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

  4. 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.

  5. Guidelines for handling radioactively contaminated decedents.

    PubMed

    Wood, Charles M; DePaolo, Frank; Whitaker, Doggett

    2008-05-01

    The Centers for Disease Control and Prevention recently issued guidelines for medical examiners, coroners, and morticians in dealing with decedents after detonation of an improvised nuclear device (IND) or radiological dispersal device (RDD) (). Partners in this effort included the New York City Office of Chief Medical Examiner and the National Funeral Directors' Association. This paper describes the handling techniques required for loose surface contamination, radioactive shrapnel, and internal contamination caused by inhaling or ingesting radioactive materials from an IND or RDD, and provides suggested guidelines for medical examiners, coroners, and morticians to deal with these situations. PMID:18403956

  6. Summary -- Experiments with Radioactive Beams Working Group

    SciTech Connect

    Vieira, D.J. (Los Alamos National Lab., NM (United States)); Wiescher, M. (Notre Dame Univ., IN (United States))

    1992-01-01

    During the course of the workshop, a wide range of futuristic radioactive-beam experiments were discussed. These extended from the study of electroweak interactions in nuclei to materials science, nuclear astrophysics, and a host of nuclear physics investigations. Emphasis was placed on illustrating how these prototypical experiments could be done, discussing what types of detection systems would be needed, exploring the new problems which would be confronting the radioactive beam experimenter, and better defining the beam requirements. Contained herein is a summary of these discussions.

  7. Summary -- Experiments with Radioactive Beams Working Group

    SciTech Connect

    Vieira, D.J. [Los Alamos National Lab., NM (United States); Wiescher, M. [Notre Dame Univ., IN (United States)

    1992-12-31

    During the course of the workshop, a wide range of futuristic radioactive-beam experiments were discussed. These extended from the study of electroweak interactions in nuclei to materials science, nuclear astrophysics, and a host of nuclear physics investigations. Emphasis was placed on illustrating how these prototypical experiments could be done, discussing what types of detection systems would be needed, exploring the new problems which would be confronting the radioactive beam experimenter, and better defining the beam requirements. Contained herein is a summary of these discussions.

  8. Radioactive Ion Beam Production Capabilities at the Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Beene, James R [ORNL; Dowling, Darryl T [ORNL; Gross, Carl J [ORNL; Juras, Raymond C [ORNL; Liu, Yuan [ORNL; Meigs, Martha J [ORNL; Mendez, II, Anthony J [ORNL; Nazarewicz, Witold [ORNL; Sinclair, John William [ORNL; Stracener, Daniel W [ORNL; Tatum, B Alan [ORNL

    2011-01-01

    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 HRIBF is the production of high-quality beams of short-lived 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.

  9. 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...

  10. 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...

  11. 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...

  12. 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...

  13. 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...

  14. [Loss and uncontrolled use of radioactive sources].

    PubMed

    Govaerts, P

    2005-01-01

    In the course of history, exposure to radioactive sources escaping regular control, has been the main cause of fatal accidents, with the exception of the reactor accident at Chernobyl. After the disintegration of the Soviet Union, numerous lost sources have been found, sometimes with serious physical damage. The attacks of September 11, 2001 have focussed the attention on the possibility of nuclear terrorism. Although the risks of fatal consequences are rather limited, the possible uncontrolled exposure to ionizing radiation has an important psycho-social impact on the population. After a brief survey of the types of radioactive sources for medical and industrial applications and a discussion of the risks and exposure routes, possible scenarios are illustrated by well documented case histories. The main conclusions of this analysis are: Radioactive materials are not unique as a potential threat by toxic materials. The most serious consequences for individuals occur as the result of external radiation, mostly with skin contact with medium-active sources which are relatively easily accessible. The collective impact is mostly psycho-social and is more important for a dispersed contamination of the environment. Many sources are detected via medical complaints. The knowledge of the specific symptoms is consequently very important. A dispersion of radioactive contamination has usually considerable economic consequences. Accidents occur particularly, but certainly not exclusively, in relatively unstable countries. Change of owner or final evacuation of the source constitute a critical phase in many scenarios. PMID:16408827

  15. High-level radioactive wastes. Supplement 1

    SciTech Connect

    McLaren, L.H. (ed.)

    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.

  16. Life cycle management of radioactive materials packaging.

    SciTech Connect

    Liu, Y.; Bellamy, S.; Shuler, J.; Decision and Information Sciences; SRL; DOE

    2007-01-01

    The objective of life cycle management of radioactive materials packaging is to ensure the safety functions (i.e. containment of radioactivity, protection against radiation, and criticality safety for fissile contents) during the entire life cycle of the packaging in storage, transportation and disposal. A framework has been developed for life cycle management regarding type B radioactive and fissile materials packaging, drawing upon current US Department of Energy (DOE) storage standards and examples from interim storage of Pu bearing materials in model 9975 transportation packagings. Key issues highlighted during long term storage of Pu bearing materials included gas generation and stability of PuO{sub 2+x}; other operation safety issues highlighted for interim storage of model 9975 transportation packagings included the need to consider a facility design basis fire event and the long term behaviour of packaging components such as Celotex and elastomeric O-ring seals. The principles of aging management are described, and the key attributes and examples of effective aging management programmes are provided based on the guidance documents for license renewal of nuclear power plants. The Packaging Certification Program of DOE Environmental Management, Office of Safety Management and Operations, plans to expand its mission into packaging certification for storage and aging management, as well as application of advanced technology, such as radiofrequency identification, for life cycle management of radioactive materials packagings.

  17. The RadioActive Networking Architecture

    Microsoft Academic Search

    Peter T. Kirstein; Piers O'hanlon; Ken Carlberg; Panos Gevros; Kristian Hasler

    2002-01-01

    This paper describes the activities in Application Level Active Networks (ALAN) under the DARPA-funded RADIOACTIVE Project; this is closely related to work carried out under a European Commission project ANDROID. The ALAN infrastructure was developed mainly under other projects; it is summarized here mainly for background. The version used here relies on separate Active Applications driven by policies - with

  18. 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.

  19. Hazardous chemical and radioactive wastes at Hanford

    SciTech Connect

    Keller, J.F.; Stewart, T.L.

    1991-07-01

    The Hanford Site was established in 1944 to produce plutonium for defense. During the past four decades, a number of reactors, processing facilities, and waste management facilities have been built at Hanford for plutonium production. Generally, Hanford`s 100 Area was dedicated to reactor operation; the 200 Area to fuel reprocessing, plutonium recovery, and waste management; and the 300 Area to fuel fabrication and research and development. Wastes generated from these operations included highly radioactive liquid wastes, which were discharged to single- and double-shell tanks; solid wastes, including both transuranic (TRU) and low-level wastes, which were buried or discharged to caissons; and waste water containing low- to intermediate-level radioactivity, which was discharged to the soil column via near-surface liquid disposal units such as cribs, ponds, and retention basins. Virtually all of the wastes contained hazardous chemical as well as radioactive constituents. This paper will focus on the hazardous chemical components of the radioactive mixed waste generated by plutonium production at Hanford. The processes, chemicals used, methods of disposition, fate in the environment, and actions being taken to clean up this legacy are described by location.

  20. Hazardous chemical and radioactive wastes at Hanford

    SciTech Connect

    Keller, J.F.; Stewart, T.L.

    1991-07-01

    The Hanford Site was established in 1944 to produce plutonium for defense. During the past four decades, a number of reactors, processing facilities, and waste management facilities have been built at Hanford for plutonium production. Generally, Hanford's 100 Area was dedicated to reactor operation; the 200 Area to fuel reprocessing, plutonium recovery, and waste management; and the 300 Area to fuel fabrication and research and development. Wastes generated from these operations included highly radioactive liquid wastes, which were discharged to single- and double-shell tanks; solid wastes, including both transuranic (TRU) and low-level wastes, which were buried or discharged to caissons; and waste water containing low- to intermediate-level radioactivity, which was discharged to the soil column via near-surface liquid disposal units such as cribs, ponds, and retention basins. Virtually all of the wastes contained hazardous chemical as well as radioactive constituents. This paper will focus on the hazardous chemical components of the radioactive mixed waste generated by plutonium production at Hanford. The processes, chemicals used, methods of disposition, fate in the environment, and actions being taken to clean up this legacy are described by location.

  1. 49 CFR 172.556 - RADIOACTIVE placard.

    Code of Federal Regulations, 2012 CFR

    2012-10-01

    ...background color on the RADIOACTIVE placard must be white in the lower portion with a yellow triangle in the upper portion. The base of the yellow triangle must be 29 mm ±5 mm (1.1 inches ±0.2 inches) above the placard horizontal...

  2. 49 CFR 172.556 - RADIOACTIVE placard.

    Code of Federal Regulations, 2010 CFR

    2010-10-01

    ...background color on the RADIOACTIVE placard must be white in the lower portion with a yellow triangle in the upper portion. The base of the yellow triangle must be 29 mm ±5 mm (1.1 inches ±0.2 inches) above the placard horizontal...

  3. 49 CFR 172.556 - RADIOACTIVE placard.

    Code of Federal Regulations, 2014 CFR

    2014-10-01

    ...background color on the RADIOACTIVE placard must be white in the lower portion with a yellow triangle in the upper portion. The base of the yellow triangle must be 29 mm ±5 mm (1.1 inches ±0.2 inches) above the placard horizontal...

  4. 49 CFR 172.556 - RADIOACTIVE placard.

    Code of Federal Regulations, 2013 CFR

    2013-10-01

    ...background color on the RADIOACTIVE placard must be white in the lower portion with a yellow triangle in the upper portion. The base of the yellow triangle must be 29 mm ±5 mm (1.1 inches ±0.2 inches) above the placard horizontal...

  5. 49 CFR 172.556 - RADIOACTIVE placard.

    Code of Federal Regulations, 2011 CFR

    2011-10-01

    ...background color on the RADIOACTIVE placard must be white in the lower portion with a yellow triangle in the upper portion. The base of the yellow triangle must be 29 mm ±5 mm (1.1 inches ±0.2 inches) above the placard horizontal...

  6. The ORNL Radioactive Ion Beam Project

    Microsoft Academic Search

    D. K. Olsen; G. D. Alton; R. L. Auble; C. Baktash; D. T. Dowling; J. D. Garrett; D. L. Haynes; C. M. Jones; R. C. Juras; M. J. Meigs; G. D. Mills; S. W. Mosko; R. L. Robinson; B. A. Tatum; H. Blosser; L. Lee; F. Marti; H. K. Carter; J. Kormicki; P. Mantica; L. Rayburn; C. A. Reed

    1992-01-01

    On June 30, 1992, the Holifield Heavy Ion Research Facility (HHIRF) was shut down as an operating national users' facility for heavy ion physics research and became a construction project to reconfigure the existing accelerator system and develop a first generation radioactive ion beam (RIB) facility. During its 11 years of operation, the HHIRF had over 600 users, of which

  7. The ORNL Radioactive Ion Beam Project

    Microsoft Academic Search

    D. K. Olsen; G. D. Alton; R. L. Auble; C. Baktash; D. T. Dowling; J. D. Garrett; D. L. Haynes; C. M. Jones; R. C. Juras; M. J. Meigs; G. D. Mills; S. W. Mosko; R. L. Robinson; B. A. Tatum; H. Blosser; L. Lee; F. Marti; H. K. Carter; J. Kormicki; P. Mantica; L. Rayburn; C. A. Reed; J. Dellwo; H. Wollnik

    1992-01-01

    On June 30, 1992, the Holifield Heavy Ion Research Facility (HHIRF) was shut down as an operating national users` facility for heavy ion physics research and became a construction project to reconfigure the existing accelerator system and develop a first generation radioactive ion beam (RIB) facility. During its 11 years of operation, the HHIRF had over 600 users, of which

  8. Radioactive scrap metal decontamination technology assessment report

    Microsoft Academic Search

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

    1996-01-01

    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

  9. RADIOACTIVE FILTER BANK FIRE DETECTION SYSTEMS

    Microsoft Academic Search

    1961-01-01

    The detection of radioactive air filter fires is discussed. Criteria ;\\u000a requirements for a suitable fire detection system were established. The ;\\u000a applicability of aircraft-type fire detection systems for this use was evaluated. ;\\u000a The operation of a discrete eutectic salt type continuous fire detection tubing ;\\u000a system is outlined. (M.C.G.)

  10. Safety Aspects in Radioactive Waste Management

    Microsoft Academic Search

    Peter W. Brennecke

    Bezpe?nostné aspekty mana?mentu rádioaktívneho odpadu In recent years, within the framework of national as well as international programmes, notable advances and considerable experience have been reached, particularly in minimising of the production of radioactive wastes, conditioning and disposal of short- lived, low and intermediate level waste, vitrification of fission product solutions on an industrial scale and engineered storage of long-

  11. Electroflotation Purification of Radioactive Waste Waters

    Microsoft Academic Search

    V. I. Il'in; V. A. Kolesnikov

    2001-01-01

    Methods for purifying radioactive waste waters are reviewed. It is shown that the electrofiltration method with insoluble electrodes is promising at the stage of separation of liquid and solid phases. The arrangement, technical-economic characteristics, and a description of the operation of an electroflotator are given.

  12. 2006 Nature Publishing Group Radioactive 26

    E-print Network

    California at Berkeley, University of

    the Cygnus region suggests that a substantial fraction of Galactic 26 Al could originate in localized star determine a present-day equilibrium mass of 2.8 (60.8) solar masses of 26 Al. We use this to determine was apparently characterized3,4 by an amount of radioactive 26 Al (relative to the stable 27 Al isotope

  13. LAND BURIAL OF SOLID PACKAGED RADIOACTIVE WASTES

    Microsoft Academic Search

    J. M. Jr. Morgan; J. C. Geyer; D. C. Costello

    1962-01-01

    A study was made of practices involved in land burial of solid packaged ; radioactive wastes in the United States. National, regional, and local burial ; grounds are discussed, as are source and character of wastes. Handling ; techniques, containers, transportation practices, and regulations are mentioned. ; Waste shippers and waste quantities are indicated and an estimate is made of

  14. High-Level Radioactive Waste Disposal

    Microsoft Academic Search

    R. C. Liikala; R. W. McKee; W. K. Winegardner

    1974-01-01

    The U.S. Atomic Energy Commission (AEC) is developing additional plans and new methods for managing radioactive wastes generated by past, present and future operations. The objectives of these programs are to; (1) ensure the health and safety of the public, (2) protect our environment and ecology, and (3) use methods acceptable to the public. A brief overview is presented of

  15. The political science of radioactive waste disposal

    Microsoft Academic Search

    Jacobi; L. R. Jr

    1996-01-01

    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

  16. Radiation hormesis: Radioactive waste for health

    Microsoft Academic Search

    Luckey

    1995-01-01

    Hormesis is the stimulation of any system by low doses of any agent. The hormesis model is particularly applicable to radioactive waste management. Radiation hormesis encompasses the beneficial effects of low-dose irradiation in both animals and humans. The radiation hormesis model comprises statistically significant (X² test) results that compare total death rates and cancer death rates in exposed and unexposed

  17. Evaluation of Terrorist Interest in Radioactive Wastes

    Microsoft Academic Search

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

    2006-01-01

    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

  18. Annual Radioactive Waste Tank Inspection Program - 1997

    SciTech Connect

    McNatt, F.G. [Westinghouse Savannah River Company, AIKEN, SC (United States)

    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.

  19. 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.

  20. DOT's proposed routing for radioactive material shipments

    Microsoft Academic Search

    J. M. Mahathy; D. G. Jacobs

    2009-01-01

    This article reviews proposed amendments to the Code of Federal Regulations, Title 49, which would give the Department of Transportation (DOT) the authority to establish a system of highway routes for vehicular shipments of large-quantity radioactive materials. These amendments would modify existing regulations pertaining to route plans, driver training, and special vehicle placards. The need for a federal routing authority

  1. Safe transport of radioactive materials in Egypt

    NASA Astrophysics Data System (ADS)

    El-Shinawy, Rifaat M. K.

    1994-07-01

    In Egypt the national regulations for safe transport of radioactive materials (RAM) are based on the International Atomic Energy Agency (IAEA) regulations. In addition, regulations for the safe transport of these materials through the Suez Canal (SC) were laid down by the Egyptian Atomic Energy Authority (EAEA) and the Suez Canal Authority (SCA). They are continuously updated to meet the increased knowledge and the gained experience. The technical and protective measures taken during transport of RAM through SC are mentioned. Assessment of the impact of transporting radioactive materials through the Suez Canal using the INTERTRAN computer code was carried out in cooperation with IAEA. The transported activities and empty containers, the number of vessels carrying RAM through the canal from 1963 to 1991 and their nationalities are also discussed. The protective measures are mentioned.A review of the present situation of the radioactive wastes storage facilities at the Atomic Energy site at Inshas is given along with the regulation for safe transportation and disposal of radioactive wastes

  2. 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.)

  3. 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.

  4. 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.

  5. Radioactive air emissions 1992 summary. Progress report

    SciTech Connect

    Wahl, L. [comp.

    1993-10-01

    This report summarizes, by radionuclide or product and by emitting facility, the Laboratory`s 1992 radioactive air emissions. In 1992, the total activity of radionuclides emitted into the air from Laboratory stacks was approximately 73,500 Ci. This was an increase over the activity of the total 1991 radioactive air emissions, which was approximately 62,400 Ci. Total 1992 Laboratory emissions of each radionuclide or product are summarized by tables and graphs in the first section of this report. Compared to 1991 radioactive air emissions, total tritium activity was decreased, total plutonium activity was decreased, total uranium activity was decreased, total mixed fission product activity was increased, total {sup 41}Ar activity was decreased, total gaseous/mixed activation product (except {sup 41}Ar) activity was increased, total particulate/vapor activation product activity was increased, and total {sup 32}P activity was decreased. Radioactive emissions from specific facilities are detailed in this report. Each section provides 1992 data on a single radionuclide or product and is further divided by emitting facility. For each facility from which a particular radionuclide or product was emitted, a bar chart displays the air emissions of each radionuclide or product from each facility over the 12 reporting periods of 1992, a line chart shows the trend in total emissions of that radionuclide or product from that facility for the past three years, the greatest activity during the 1990--1992 period is discussed, and unexpected or unusual results are noted.

  6. Security in the Transport of Radioactive Materials

    Microsoft Academic Search

    Ron Pope; Richard R Rawl

    2010-01-01

    The United States Department of Energy National Nuclear Security Administration's (DOE\\/NNSA)Global Threat Reduction Initiative (GTRI), the International Atomic Energy Agency (IAEA) and active IAEA Donor States are working together to strengthen the security of nuclear and radioactive materials during transport to mitigate the risks of theft, diversion, or sabotage. International activities have included preparing and publishing the new IAEA guidance

  7. 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.

  8. 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…

  9. Holifield Radioactive Ion Beam Facility Status

    SciTech Connect

    Stracener, Daniel W [ORNL; Beene, James R [ORNL; Dowling, Darryl T [ORNL; Juras, Raymond C [ORNL; Liu, Yuan [ORNL; Meigs, Martha J [ORNL; Mendez, II, Anthony J [ORNL; Mueller, Paul Edward [ORNL; Sinclair, John William [ORNL; Tatum, B Alan [ORNL; Sinclair IV, John W [ORNL

    2009-01-01

    The Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory (ORNL) produces high-quality beams of short-lived radioactive isotopes for nuclear science research, and is currently unique worldwide in the ability to provide neutron-rich fission fragment beams post-accelerated to energies above the Coulomb barrier. HRIBF is undergoing a multi-phase upgrade. Phase I (completed 2005) was construction of the High Power Target Laboratory to provide the on-going Isotope Separator On-Line (ISOL) development program with a venue for testing new targets, ion sources, and radioactive ion beam (RIB) production techniques with high-power beams. Phase II, which is on schedule for completion in September 2009, is the Injector for Radioactive Ion Species 2 (IRIS2), a second RIB production station that will improve facility reliability and accommodate new ion sources, new RIB production targets, and some innovative RIB purification techniques, including laser applications. The Phase III goal is to substantially improve facility performance by replacing or supplementing the Oak Ridge Isochronous Cyclotron (ORIC) production accelerator with either a high-power 25-50 MeV electron accelerator or a high-current multi-beam commercial cyclotron. Either upgrade is applicable to R&D on isotope production for medical or other applications.

  10. Improved heat transfer from radioactive waste canisters

    Microsoft Academic Search

    G. Jansen; J. D. Kaser

    1974-01-01

    From joint meeting of the American Nuclear Society and the Atomic ; lndustrial Forum and Nuclear Energy Exhibition; San Francisco, California, USA ; (11 Nov 1973). Since the radioisotope content that can be tolerated in a ; canister full of radioactive waste is limited by the amount of heat which can be ; dissipated from the waste to the surroundings,

  11. Indirect estimation of radioactivity in containerized cargo

    Microsoft Academic Search

    Kenneth D. Jarman; Chad Scherrer; L. E. Smith; Lawrence Chilton; K. K. Anderson; Jennifer J. Ressler; Lynn L. Trease

    2011-01-01

    Naturally occurring radioactive material in containerized cargo challenges the state of the art in national and international efforts to detect illicit nuclear and radiological material in transported containers. Current systems are being evaluated and new systems envisioned to provide the high probability of detection necessary to thwart potential threats, combined with extremely low nuisance and false alarm rates necessary to

  12. Optimization of mobile radioactivity monitoring networks

    Microsoft Academic Search

    Gerard B. M. Heuvelink; Z. Jiang; S. De Bruin; C. J. W. Twenhöfel

    2010-01-01

    In case of a nuclear accident, decision makers rely on high resolution and accurate information about the spatial distribution of the radioactivity levels in the surroundings of the acc ident site. Static nuclear monitoring networks are therefore employed in many countries in Europe. However, these networks were designed to cover the whole country and are usually too course to reach

  13. rev September 2003 Radiation Safety Manual Section 11 Procurement of Radioactive Material

    E-print Network

    Wilcock, William

    rev September 2003 Radiation Safety Manual Section 11 ­ Procurement of Radioactive Material Page 11-1 Section 11 Procurement of Radioactive Materials Contents A. Authorization to Order Radioactive Materials. Disposal of Packaging Materials ...................................................11-3 E. Radioactive

  14. System for measuring radioactivity of labelled biopolymers

    SciTech Connect

    Gross, V.

    1980-07-08

    A system is described for measuring radioactivity of labelled biopolymers, comprising: a set of containers adapted for receiving aqueous solutions of biological samples containing biopolymers which are subsequently precipitated in said containers on particles of diatomite in the presence of a coprecipitator, then filtered, dissolved, and mixed with a scintillator; radioactivity measuring means including a detection chamber to which is fed the mixture produced in said set of containers; an electric drive for moving said set of containers in a stepwise manner; means for proportional feeding of said coprecipitator and a suspension of diatomite in an acid solution to said containers which contain the biological sample for forming an acid precipitation of biopolymers; means for the removal of precipitated samples from said containers; precipitated biopolymer filtering means for successively filtering the precipitate, suspending the precipitate, dissolving the biopolymers mixed with said scintillator for feeding of the mixture to said detection chamber; a system of pipelines interconnecting said above-recited means; and said means for measuring radioactivity of labelled biopolymers including, a measuring cell arranged in a detection chamber and communicating with said means for filtering precipitated biopolymers through one pipeline of said system of pipelines; a program unit electrically connected to said electric drive, said means for acid precipatation of biopolymers, said means for the removal of precipitated samples from said containers, said filtering means, and said radioactivity measuring device; said program unit adapted to periodically switch on and off the above-recited means and check the sequence of the radioactivity measuring operations; and a control unit for controlling the initiation of the system and for selecting programs.

  15. Radioactive Waste Management in Central Asia - 12034

    SciTech Connect

    Zhunussova, Tamara; Sneve, Malgorzata; Liland, Astrid [Norwegian Radiation Protection Authority (Norway)

    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)

  16. Radiation safety of sealed radioactive sources.

    PubMed

    Pryor, Kathryn H

    2015-02-01

    Sealed radioactive sources are used in a wide variety of occupational settings and under differing regulatory/licensing structures. The definition of a sealed radioactive source varies between U.S. regulatory authorities and standard-setting organizations. Potential problems with sealed sources cover a range of risks and impacts. The loss of control of high activity sealed sources can result in very high or even fatal doses to members of the public who come in contact with them. Sources that are not adequately sealed and that fail can cause spread of contamination and potential intake of radioactive material. There is also the possibility that sealed sources may be (or threaten to be) used for terrorist purposes and disruptive opportunities. Until fairly recently, generally licensed sealed sources and devices received little, if any, regulatory oversight and were often forgotten, lost or unaccounted for. Nonetheless, generally licensed devices can contain fairly significant quantities of radioactive material, and there is some potential for exposure if a device is treated in a way for which it was never designed. Industrial radiographers use and handle high activity and/or high dose-rate sealed sources in the field with a high degree of independence and minimal regulatory oversight. Failure to follow operational procedures and properly handle radiography sources can and has resulted in serious injuries and death. Industrial radiographers have experienced a disproportionately large fraction of incidents that have resulted in unintended exposure to radiation. Sources do not have to contain significant quantities of radioactive material to cause problems in the event of their failure. A loss of integrity can cause the spread of contamination and potential exposure to workers and members of the public. The National Council on Radiation Protection and Measurements has previously provided recommendations on select aspects of sealed source programs. Future efforts to provide recommendations for sealed source programs are discussed. PMID:25551499

  17. 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

  18. SMALL-SCALE DECONTAMINATION OF RADIOACTIVE WATERS BY ION EXCHANGE

    Microsoft Academic Search

    M. B. Sonnen; A. D. Ray

    1963-01-01

    Immediately following nuclear war events, it is anticipated that surface ; waters will be contaminated by radioactive fallout materials and it appears ; desirable to minimize the amounts of ingested radioactive materials for a period ; of time to reduce the radiation doses of the population. Although drinking ; waters free of radioactivity may be provided by prior storage, or

  19. Low-level radioactive waste regulation: Science, politics and fear

    Microsoft Academic Search

    1988-01-01

    An inevitable consequence of the use of radioactive materials is the generation of radioactive wastes and the public policy debate over how they will be managed. In 1980, Congress shifted responsibility for the disposal of low-level radioactive wastes from the federal government to the states. This act represented a sharp departure from more than 30 years of virtually absolute federal

  20. Educational support programs: Office of Civilian Radioactive Waste Management

    Microsoft Academic Search

    1989-01-01

    The Office of Civilian Radioactive Waste Management (OCRWM) currently sponsors two educationally related programs: the Radioactive Waste Management Fellowship Program and the Radioactive Waste Management Research Program for Historically Black Colleges and Universities (HBCU). The graduate fellowship program was implemented in 1985 to meet the US Department of Energy's (DOE's) expected manpower needs for trained scientists and engineers to assist

  1. Boom and future of radioactive prospecting for oil and gas

    SciTech Connect

    Yuande, Q.; Jinhua, L.; Youqing, Z.; Longchang, W. (Third Dept., Chengdu Geology College, Chengdu City, Sichuan Province (CN))

    1992-01-01

    In this paper, the authors sketch out the general development situation of radioactive oil and gas explorations, the mechanism of radioactive anomaly, the application of radon method to oil and gas explorations, and some examples. It is pointed out that with the advance of science and technology, radioactive method will get consummate and very promising in oil and gas explorations.

  2. Integrating natural and social sciences to inspire public confidence in radioactive waste policy case study - Committee on radioactive waste management

    Microsoft Academic Search

    Usher

    2007-01-01

    Integrating Natural and Social Sciences to Inspire Public Confidence in Radioactive Waste Policy Case Study: Committee on Radioactive Waste Management Implementing effective long-term radioactive waste management policy is challenging, and both UK and international experience is littered with policy and programme failures. Policy must not only be underpinned by sound science and technical rationale, it must also inspire the confidence

  3. Emissions of naturally occurring radioactivity: fireclay mine and refractory plant

    SciTech Connect

    Andrews, V.E.

    1981-02-01

    Atmospheric emissions of naturally occurring radioactivity were measured at a fireclay mine and the associated plant that produces refractory brick products. The only significant radioactive emission from the mine was radon-222. An analysis of the ore radioactivity and surface area of the mine indicated that the radon released is comparable to that from any similar surface area of similar radioactivity. The major particulate radioactivity from the refractory operation was polonium-210, released as the brick was fired. Approximately 26 percent of the polonium-210 in green brick was driven off in the kilns.

  4. 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.

  5. 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.

  6. USDOE radioactive waste incineration technology: status review

    SciTech Connect

    Borduin, L.C.; Taboas, A.L.

    1980-01-01

    Early attempts were made to incinerate radioactive wastes met with operation and equipment problems such as feed preparation, corrosion, inadequate off-gas cleanup, incomplete combustion, and isotope containment. The US Department of Energy (DOE) continues to sponsor research, development, and the eventual demonstration of radioactive waste incineration. In addition, several industries are developing proprietary incineration system designs to meet other specific radwaste processing requirements. Although development efforts continue, significant results are available for the nuclear community and the general public to draw on in planning. This paper presents an introduction to incineration concerns, and an overview of the prominent radwaste incineration processes being developed within DOE. Brief process descriptions, status and goals of individual incineration systems, and planned or potential applications are also included.

  7. Comparative alkali washing of simulated radioactive sludge

    SciTech Connect

    Fugate, G.A.; Ensor, D.D. [Tennessee Technological Univ., Cookeville, TN (United States); Egan, B.Z. [Oak Ridge National Lab., TN (United States)

    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.

  8. Radioactivity in bottled waters sold in Mexico.

    PubMed

    Dávila Rangel, J I; López del Rio, H; Mireles García, F; Quirino Torres, L L; Villalba, M L; Colmenero Sujo, L; Montero Cabrera, M E

    2002-06-01

    Measurements of gross alpha and beta activities were made on 21 domestic and international brands of bottled (purified and mineral) water sold in the Mexican market to assess its radiological quality. Alpha and beta activities were determined using a liquid-scintillation detector with pulse-shape analysis feature. All the purified water had values of beta activity lower than the limit for potable drinking water (1.0 Bq/l), while three brands surpassed the limit of alpha activity (0.1 Bq/l). The limit for alpha radioactivity content was exceed by three mineral waters; the results show a correlation between radioactivity content and mineral salts, which are related with the origin and treatment of the waters. PMID:12102353

  9. Mathematical modeling of radioactive waste glass melter

    Microsoft Academic Search

    1990-01-01

    The radioactive waste glass melter used at Savannah River Site (SRS) is a liquid slurry feed joule-heated ceramic melter. The physical nature of a joule-heated meter is complex and involves interactions between electric, thermal, and flow fields. These interactions take place through strongly temperature-dependent glass properties, natural convection, advection, diffusion, and volumetrically distributed joule heating sources. The cold feed on

  10. Transport of Carbon Dioxide and Radioactive Waste

    Microsoft Academic Search

    Darío R. Gómez; Michael Tyacke

    \\u000a A comparative assessment of carbon dioxide (CO2) and radioactive waste transport systems associated with electricity generation was undertaken on the basis of 15 criteria\\u000a grouped under three areas, namely the transport chain, policy aspects and state of the technology. For CO2, we considered exclusively the transport that would take place under a future large-scale capture and storage infrastructure.\\u000a Our study

  11. Development of cryogenic detectors for radioactivity metrology

    Microsoft Academic Search

    E Leblanc; P Cassette; J Bouchard; J Plagnard

    1998-01-01

    Low temperature detectors are expected to improve radioactivity measurements as they offer two major advantages compared to classical semiconductor detectors: excellent energy resolution (10eV for 6keV X-rays) and 100% detection efficiency for low energy X-rays (i.e. 1–10keV). The main difficulties encountered in the development of such detectors are their high sensitivity to electromagnetic noise and acoustic vibrations. These difficulties are

  12. Studies with Exotic Nuclei: Two Proton Radioactivity

    SciTech Connect

    Borcea, C.; Blank, B.; Canchel, G.; Demonchy, C. E.; Giovinazzo, J.; Hay, L.; Huikari, J.; Leblanc, S.; Matea, I.; Pedroza, J.-L.; Pibernat, J.; Serani, L. [Centre d'etudes nucleaires de Bordeaux-Gradignan, Universite Bordeaux 1-UMR 5797 CNRS/IN2P3, Chemin du Solarium, BP 120, F-33175 Gradignan Cedex (France); Oliveira Santos, F. de; Grevy, S.; Perrot, L.; Stodel, C.; Thomas, J.-C. [Grand Accelerateur National d'Ions Lourds, CEA/DSM-CNRS/IN2P3, Bvd Henri Becquerel, BP 55027, F-14076 CAEN Cedex 5 (France); Dossat, C. [DAPNIA, CEA Saclay, F-91191 Gif-sur-Yvette Cedex (France)

    2008-01-24

    In the present paper, we present measurements that led to the discovery of two-proton radioactivity. After the first observation of this decay mode for {sup 45}Fe, new measurements evidenced this decay mode also for {sup 54}Zn and most likely {sup 48}Ni. A new detector based on the time-projection chamber principle allowed now to visualize the two protons directly.

  13. Radioactive Decay Law (Rutherford–Soddy)

    Microsoft Academic Search

    Friedel Weinert

    The formulation of the radioactive decay law, in 1902, by Ernest Rutherford (1871–1937) and Frederick Soddy (1877–1956) was\\u000a part of a number of discoveries around the turn of the century, which paved the way to the establishment of quantum mechanics,\\u000a as the physics of the atom. In November 1895, W. Röntgen (1845–1923) discovered ? X-rays; in 1896 A. H. Becquerel

  14. Recycling radioactively contaminated materials: Experience and prognosis

    Microsoft Academic Search

    D. E. Large; H. W. Arrowsmith

    1993-01-01

    In recent years, federal agencies, especially the U.S. Department of Energy (DOE), the U.S. Department of Defense (DOD), the U.S. Environmental Protection Agency, and the U.S. Nuclear Regulatory Commission (NRC), as well as the commercial nuclear enterprise, have begun to consider certain radioactively contaminated materials as resources for beneficial reuse rather than wastes. Most outstanding among these materials is metal

  15. Modelling indoor exposure to natural radioactive nuclides

    Microsoft Academic Search

    W. Hofmann; F. Daschil

    1986-01-01

    Radon enters buildings from several sources, principally building materials and the soil or rock that underlie or surround\\u000a building foundations. The basic processes determining indoor concentrations are radioactive transmutations, attachment to\\u000a aerosol particles, detachment by alpha particle recoil, plate-out on furniture and walls, and exchange with the outdoor air\\u000a by natural or mechanical ventilation.\\u000a \\u000a A multicompartment model has been developed

  16. 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.

  17. 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…

  18. Radioactive contamination of the Yenisei River

    Microsoft Academic Search

    E. G. Tertyshnik

    1995-01-01

    Based on observational data in the period 1971–1993, radioactive contamination of the Yenisei River ecosystem was analysed within 2000 km of the site of discharges from the Krasnoyarsk Mining and Chemical Industrial Complex. Data on the content of 24Na, 32P, 46Sc, 51Cr, 54Mn, 56Mn, 58Co, 60Co, 59Fe, 65Zn, 90Sr, 95Zr, 95Nb, 103Ru, 106Ru, 134Cs, 137Cs, 140Ba, 141Ce, 144Ce and 239Np

  19. Sources of Radioactive Isotopes for Dirty Bombs

    NASA Astrophysics Data System (ADS)

    Lubenau, Joel

    2004-05-01

    From the security perspective, radioisotopes and radioactive sources are not created equal. Of the many radioisotopes used in industrial applications, medical treatments, and scientific research, only eight, when present in relatively large amounts in radioactive sources, pose high security risks primarily because of their prevalence and physical properties. These isotopes are americium-241, californium-252, cesium-137, cobalt-60, iridium-192, radium-226, plutonium-238, and strontium-90. Except for the naturally occurring radium-226, nuclear reactors produce the other seven in bulk commercial quantities. Half of these isotopes emit alpha radiation and would, thus, primarily pose internal threats to health; the others are mainly high-energy gamma emitters and would present both external and internal health hazards. Therefore, the response to a "dirty bomb" event depends on what type of radioisotope is chosen and how it is employed. While only a handful of major corporations produce the reactor-generated radioisotopes, they market these materials to thousands of smaller companies and users throughout the world. Improving the security of the high-risk radioactive sources will require, among other efforts, cooperation among source suppliers and regulatory agencies.

  20. Radioactive nuclear beams: Present and future

    NASA Astrophysics Data System (ADS)

    Penionzhkevich, Yu. E.

    2014-11-01

    Some results of investigations into a new nuclear-physics field associated with the production of radioactive nuclear beams and physical studies with these beams are presented. The most recent results obtained by studying the structure of nuclei and reaction mechanisms with radioactive nuclear beams are surveyed. Data obtained in Dubna at the DRIBs accelerator complex are presented along with allied results from other research centers. In this connection, existing experimental data on light loosely bound exotic nuclei are discussed. The parameters of DRIBs3, which is a new accelerator complex, are presented, and the physics research program that will be implemented with the aid of new setups, including a high-resolution magnetic analyzer (MAVR) and a 4 ? neutron detector (TETRA), is described. A collaboration in the realms of employing radioactive nuclear beams at the DRIBs complex together with other accelerator complexes [SPIRAL2 (France), RIKEN (Japan), FAIR (Germany), and RIBF (CIIIA)] on the basis of employing new highly efficient experimental facilities has already led to the discovery of new phenomena in nuclear physics and will make it possible to study in the future new regions of nuclear matter in extreme states.

  1. [Working environment measurement of radioactive substances].

    PubMed

    Kunugita, Naoki

    2007-12-01

    The control of the working environment is one of the most important duties in any working place to prevent occupational disease. In Japan, in the case of the controlled area using unsealed radioisotopes, the measurement of the concentration of airborne radioactive substances should be carried out under the regulations of the "Industrial Safety and Health Law" and the "Ordinance on Prevention of Ionizing Radiation Hazards". Many reports showed that the results of regular working environment measurements of radioactive substances were about background levels. Safe working environments are sufficiently guaranteed by a suitable estimation and handling under the strict regulation by the "Laws Concerning the Prevention from Radiation Hazards Due to Radioisotopes and Others". The regulation by "Ordinance on Prevention of Ionizing Radiation Hazards" would be relaxed in the field of education and research, which use very low quantities of radioactive substances, in ways such as estimation by calculation in place of the actual measurement, decrease of the number of monthly measurements, and measurement exemption for low levels of isotopes. PMID:18170964

  2. 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.

  3. RESRAD. Site-Specific Residual Radioactivity

    SciTech Connect

    Yu, C. [Argonne National Laboratory, IL (United States)

    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.

  4. Scrap metals industry perspective on radioactive materials.

    PubMed

    Turner, Ray

    2006-11-01

    With more than 80 reported/confirmed accidental melts worldwide since 1983 and still counting, potential contamination by radioactive materials remains as a major concern among recycled scrap and steel companies. Some of these events were catastrophic and have cost the industry millions of dollars in business and, at the same time, resulted in declining consumer confidence. It is also known that more events with confirmed radioactive contamination have occurred that involve mining of old steel slag and skull dumps. Consequently, the steel industry has since undergone massive changes that incurred unprecedented expenses through the installation of radiation monitoring systems in hopes of preventing another accidental melt. Despite such extraordinary efforts, accidental melts continue to occur and plague the industry. One recent reported/confirmed event occurred in the Republic of China in 2004, causing the usual lengthy shutdown for expensive decontamination efforts before the steel mill could resume operations. With this perspective in mind, the metal industry has a long-standing opposition to the release of radioactive materials of any kind to commerce for fear of contamination and the potential consequences. PMID:17033460

  5. 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.

  6. 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. [EG and G Idaho, Inc., Idaho Falls, ID (United States); Otis, M.D.; McKenzie-Carter, M.A.; Schurman, D.L. [Science Applications International Corp., Idaho Falls, ID (United States)

    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.

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

    SciTech Connect

    Fischer, D.K.; Gitt, M.; Williams, G.A.; Branch, S. (EG and G Idaho, Inc., Idaho Falls, ID (United States)); Otis, M.D.; McKenzie-Carter, M.A.; Schurman, D.L. (Science Applications International Corp., Idaho Falls, ID (United States))

    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.

  8. Upgrading the Radioactive Waste Management Infrastructure in Azerbaijan

    SciTech Connect

    Huseynov, A. [Baku Radioactive Waste Site IZOTOP, Baku (Azerbaijan); Batyukhnova, O. [State Unitary Enterprise Scientific and Industrial Association Radon, Moscow (Russian Federation); Ojovan, M. [Sheffield Univ., Immobilisation Science Lab. (United Kingdom); Rowat, J. [International Atomic Energy Agency, Dept. of Nuclear Safety and Security, Vienna (Austria)

    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)

  9. Estimation of monosaccharide radioactivity in biological samples through osazone derivatization

    SciTech Connect

    Garcia, F.J.; Pons, A.; Alemany, M.; Palou, A.

    1982-03-01

    A method for the quantitative estimation of radioactivity in the glucose (monosaccharide) fraction of biological samples is presented. Radioactive samples are added with cold glucose, and 1 aliquot receives a known amount of radioactive glucose as internal standard. After controlled osazone formation and three washings of the yellow precipitate, the osazones are dissolved, decolored, and their radioactivity determined through scintillation counting. The overall efficiency of recovery is 23-24% of the initial readioactivity. Each sample is corrected by the recovery of its own internal standard. There is a very close linear relationship between radioactivity present in the samples and radioactivity found, despite the use of different biological samples (rat plasma, hen egg yolk and albumen).

  10. Environmental Assessment Radioactive Source Recovery Program

    SciTech Connect

    NONE

    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.

  11. Hydrogen gettering the overpressure gas from highly radioactive liquids

    Microsoft Academic Search

    D. L. Riley; J. C. McCoy; J. R. Schicker

    1996-01-01

    Remediation of current inventories of high-activity radioactive liquid waste (HALW) requires transportation of Type-B quantities of radioactive material, possibly up to several hundred liters. However, the only currently certified packaging is limited to quantities of 50 ml (0.01 gal) quantities of Type-B radioactive liquid. Efforts are under way to recertify the existing packaging to allow the shipment of up to

  12. 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.

  13. Radioactive heat sources in the lunar interior.

    NASA Technical Reports Server (NTRS)

    Hays, J. F.

    1972-01-01

    Published models for the moon's thermal history typically imply present day central temperatures far too high to be consistent with the recently proposed lunar temperature profile of Sonett et al. (1971). Furthermore, chemical data on Apollo samples show that the moon is depleted relative to chondrites in volatile elements, and possibly enriched relative to chondrites in refractory elements. Additional thermal models have therefore been investigated in order to set upper limits on lunar radioactivity consistent with the proposed temperature distribution. For an initially cold, uniform moon, devoid of potassium, a maximum uranium content of 23 parts per billion is inferred.

  14. Silicon photomultipliers for radioactive waste online monitoring

    NASA Astrophysics Data System (ADS)

    Finocchiaro, P.; Barbagallo, M.; Cosentino, L.; Greco, G.; Guardo, G.; Pappalardo, A.; Scirè, C.; Scirè, S.

    2011-10-01

    A prototype demonstrator for the online monitoring of short-medium term radioactive waste repositories is currently under development at INFN-LNS. Such a system is planned to be distributed, fine-grained, robust, reliable, and based on low-cost components. With the main purpose of counting gamma radiation, we implemented a new kind of mini-detector based on silicon photomultipliers and scintillating fibers that behaves like a cheap scintillating Geiger-Muller counter and is suitable to be deployed in the shape of a grid around waste drums.

  15. 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.

  16. Low radioactivity at the Modane Underground Laboratory

    NASA Astrophysics Data System (ADS)

    Loaiza, Pia

    2005-09-01

    The Modane Underground Laboratory, with an overburden of 4800 m.w.e, offers an excellent site for experiments requiring a low-background environment. The laboratory is currently hosting experiments in particle and astroparticle physics and low-level germanium gamma-ray spectrometry activities. This paper sketchs the main characteristics, scientific activities and facilities of the laboratory as well as its insertion in the European program ILIAS. Special emphasis is given to the description of the low radioactivity measurements and Germanium detectors.

  17. Low radioactivity at the Modane Underground Laboratory

    SciTech Connect

    Loaiza, Pia [Laboratoire Souterrain de Modane, 90 rue Polset, 73500 Modane (France)

    2005-09-08

    The Modane Underground Laboratory, with an overburden of 4800 m.w.e, offers an excellent site for experiments requiring a low-background environment. The laboratory is currently hosting experiments in particle and astroparticle physics and low-level germanium gamma-ray spectrometry activities. This paper sketches the main characteristics, scientific activities and facilities of the laboratory as well as its insertion in the European program ILIAS. Special emphasis is given to the description of the low radioactivity measurements and Germanium detectors.

  18. Fallout Radioactivity in Cattle and Its Effects.

    PubMed

    Van Dilla, M A; Farmer, G R; Bohman, V R

    1961-04-01

    The levels of strontium-90 and cesium-137 in cattle grazed on the Nevada Test Site and elsewhere in Nevada are similar to those in cattle from other parts of the country. Gastrointestinal absorption of the relatively large amounts of radioactive cerium-praseodymium, ruthenium-rhodium, and zirconium-niobium present in the rumina is very small. Zinc-65 made its first appearance in samples of muscle and liver in November 1958 and has persisted in later samplings. There has been no evidence of biological damage to date, either histologically or grossly. PMID:17742773

  19. 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.

  20. 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.

  1. 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.

  2. Astrophysics experiments with radioactive beams at ATLAS

    NASA Astrophysics Data System (ADS)

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

    2014-04-01

    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.

  3. Hazardous and radioactive waste incineration studies

    SciTech Connect

    Vavruska, J.S.; Stretz, L.A.; Borduin, L.C.

    1981-01-01

    Development and demonstration of a transuranic (TRU) waste volume-reduction process is described. A production-scale controlled air incinerator using commercially available equipment and technology has been modified for solid radioactive waste service. This unit successfully demonstrated the volume reduction of transuranic (TRU) waste with an average TRU content of about 20 nCi/g. The same incinerator and offgas treatment system is being modified further to evaluate the destruction of hazardous liquid wastes such as polychlorinated biphenyls (PCBs) and hazardous solid wastes such as pentachlorophenol (PCP)-treated wood.

  4. 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.

  5. 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.

  6. Preparation and characterization of radioactive castanospermine

    SciTech Connect

    Keenan, R.W.; Pan, Y.T.; Elbein, A.D.

    1987-06-01

    A procedure for the preparation of tritiated castanospermine is described. The tritiated alkaloid was shown to be chromatographically identical to the native material and exhibited the same inhibitory properties. Radiolabeled castanospermine tightly bound to purified intestinal sucrase. Following gel chromatography, each mole of enzyme was shown to have bound 1 mol of the radioactive alkaloid. Cultured MDCK cells were also shown to take up the labeled castanospermine. This compound should be a useful tool in the investigation of enzymes that are responsible for the processing of glycoprotein oligosaccharides.

  7. A geochemically consistent hypothesis for MORB generation

    Microsoft Academic Search

    C. C Lundstrom; J Gill; Q Williams

    2000-01-01

    Geochemical observations of MORB including U-series disequilibria are used to examine the processes and timescales of MORB melt generation. Incompatible elements in MORB suggest that the MORB source region consists of a depleted lherzolite matrix interspersed with chemically enriched mafic veins. Wide variations in Th\\/U distinguish these source variations in MORB better than 87Sr\\/86Sr and document that the relative chemical

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

    Microsoft Academic Search

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

    1991-01-01

    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

  9. Radioactive Waste Control and Controversy: The History of Radioactive Waste Regulation in the UK

    Microsoft Academic Search

    J H Jackson

    1999-01-01

    A hundred years on from the discovery of radioactivity, we have the first book describing the history of the regulation in the UK of the waste arising from its many uses. The first book? Believe it or not, yes. There have been others which provide commentaries on the development (or hapless evolution?) of policy per se and it would be

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

    SciTech Connect

    Himmerkus, Felix; Rittmeyer, Cornelia [WAK Rueckbau- und Entsorgungs- GmbH, 76339 Eggenstein-Leopoldshafen (Germany)

    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)

  11. "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…

  12. National debate on the handling of radioactive wastes from nuclear power plants

    Microsoft Academic Search

    T. R. Lash; J. E. Bryson; R. Cotton

    1974-01-01

    The following aspects of radioactive wastes from nuclear power plants ; are discussed: generation of radioactive wastes and the health hazards posed by ; radioactivity; radioactive waste management programs, plans, and alternatives, U. ; S. experience with radioactive waste management, and citizen action. (LK)

  13. SN IA light curves and radioactive decay

    NASA Astrophysics Data System (ADS)

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

    1997-12-01

    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, reinforcing 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 (M_Ni = 0.1-1.1 M_sun,) and a factor 2 in the total mass of the ejecta (M_ej = 0.7-1.4 M_sun). Differences of a factor 2 in M_Ni 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. Based on ESO observations collected at ESO-La Silla (Chile)

  14. Radioactive materials in biosolids : dose modeling.

    SciTech Connect

    Wolbarst, A. B.; Chiu, W. A; Yu, C.; Aiello, K.; Bachmaier, J. T.; Bastian, R. K.; Cheng, J. -J.; Goodman, J.; Hogan, R.; Jones, A. R.; Kamboj, S.; Lenhartt, T.; Ott, W. R.; Rubin, A.; Salomon, S. N.; Schmidt, D. W.; Setlow, L. W.; Environmental Science Division; U.S. EPA; Middlesex County Utilities Authority; U.S. DOE; U.S. NRC; NE Ohio Regional Sewer District

    2006-01-01

    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 transport of radioactivity from sludge into the local environment and the subsequent exposure of humans. A stochastic environmental pathway model was applied separately to seven hypothetical, generic sludge-release scenarios, leading to the creation of seven tables of Dose-to-Source Ratios (DSR), which can be used in translating from specific activity in sludge into dose to an individual. These DSR values were then combined with the results of an ISCORS survey of sludge and ash at more than 300 publicly owned treatment works, to explore the potential for radiation exposure of sludge workers and members of the public. This paper provides a brief overview of the pathway modeling methodology employed in the exposure and dose assessments and discusses technical aspects of the results obtained.

  15. Crystallization of sodium nitrate from radioactive waste

    SciTech Connect

    Krapukhin, V.B.; Krasavina, E.P. Pikaev, A.K. [Russian Academy of Sciences, Moscow (Russian Federation). Institute of Physical Chemistry

    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.

  16. 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.

  17. Marie Curie and the Science of Radioactivity

    NSDL National Science Digital Library

    2006-12-07

    This digital exhibit explores the life and accomplishments of Marie Curie, the Nobel-Prize winning physicist who discovered the radioactive elements polonium and radium. The exhibit integrates primary source lab notes, diary and journal entries, and historic photos to give a poignant view of Curie's struggles: growing up in the Russian-controlled Poland of the late 19th Century, being the target of repeated discrimination during her higher education in Paris, working with radioactive materials in substandard lab conditions, dealing with the consuming grief of her husband, Pierre's, accidental death in 1906, and overcoming challenges to win two Nobel Prizes. Editor's Note: It can be difficult for students to appreciate science as a human endeavor. This resource was designed to help learners grasp the hardships and obstacles often faced by pioneering scientists, especially women and minorities. Just as important, it gives them a glimpse at the joys of discovery. For a simulation on the same topic, see Related Materials: PhET Alpha Decay, which contains a very good accompanying lesson plan for high school teachers.

  18. Directions in low-level radioactive waste management: A brief history of commercial low-level radioactive waste disposal

    SciTech Connect

    Not Available

    1994-08-01

    This report presents a history of commercial low-level radioactive waste disposal in the United States, with emphasis on the history of six commercially operated low-level radioactive waste disposal facilities. The report includes a brief description of important steps that have been taken during the last decade to ensure the safe disposal of low-level radioactive waste in the 1990s and beyond. These steps include the issuance of comprehensive State and Federal regulations governing the disposal of low-level radioactive waste, and the enactment of Federal laws making States responsible for the disposal of such waste generated within their borders.

  19. 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

  20. 77 FR 36017 - Regulatory Guide 7.3, Procedures for Picking Up and Receiving Packages of Radioactive Material

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-06-15

    ...Packages of Radioactive Material.'' The...Compliance with Packaging Requirements...Receipt of Radioactive Material'' which...Compliance with Packaging Requirements...Receipt of Radioactive Material.''...

  1. Issues in radioactive-waste management for fusion power

    Microsoft Academic Search

    R. C. Maninger; D. W. Dorn

    1082-01-01

    Analysis of recent conceptual designs reveals that commercial fusion power systems will raise issues of occupational and public health and safety. This paper focuses on radioactive wastes from fusion reactor materials activated by neutrons. The analysis shows that different selections of materials and neutronic designs can make differences in orders-of-magnitude of the kinds and amounts of radioactivity to be expected.

  2. Issues in radioactive waste management for fusion power

    Microsoft Academic Search

    R. C. Maninger; D. W. Dorn

    1983-01-01

    Analysis of recent conceptual designs reveals that commercial fusion power systems will raise issues of occupational and public health and safety. This paper focuses on radioactive wastes from fusion reactor materials activated by neutrons. The analysis shows that different selections of materials and neutronic designs can make differences in orders-of magnitude of the kinds and amounts of radioactivity to be

  3. Environmental impact of radioactive silver released from nuclear power plant

    Microsoft Academic Search

    Ž. Vukovi?

    2002-01-01

    Radioactive silver 110mAg is not a fission product, but as a contaminant originating from Chernobyl, was registered in many European countries. The environmental impact of radioactive silver was specially expressed in the process of obtaining copper and noble metals from ores originating from opencast mines. Direct consequence was contaminated metal silver in the period of several years after the Chernobyl

  4. Artificial Radioactivity of Dysprosium and other Rare Earth Elements

    Microsoft Academic Search

    G. Hevesy; Hilde Levi

    1935-01-01

    IN their pioneer work on artificial radioactivity through neutron bombardment, Fermi and his collaborators announced the discovery of the activity of some of the rare earth elements, namely, of lanthanum, praseodymium, neodymium, samarium and gadolinium. Recently, Sugden1 found that terbium shows an appreciable, and europium a very strong, radioactivity after bombardment with neutrons. We find that dysprosium shows an unusually

  5. 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)

  6. RESRAD, a computer model for deriving residual radioactive material guidelines

    Microsoft Academic Search

    C. Yu; T. L. Gilbert; U. C. Yuan; A. Zielen; A. Wallo

    1989-01-01

    The U.S. Department of Energy has established radiological protection guidelines for the cleanup of residual radioactive material at sites administered under its Formerly Utilized Sites Remedial Action Program (FUSRAP) and Surplus Facilities Management Program. The guidelines establish radionuclide concentrations or radioactivity levels that are acceptable if the site is to be used without radiological restrictions. Guidelines can be categorized as

  7. Ris-R-1549(EN) Thule-2003 -Investigation of Radioactive

    E-print Network

    contamination of surface soil at Narssarssuk could constitute a small risk to humans visiting the locationRisø-R-1549(EN) Thule-2003 - Investigation of Radioactive Contamination Sven P. Nielsen and Per: Thule-2003 ­ Investigation of Radioactive Contamination Department: Radiation Research Risø-R-1549(EN

  8. Ocean dumping of low-level radioactive waste

    Microsoft Academic Search

    Hunsaker

    1984-01-01

    Ocean dumping of low-level radioactive waste in the US is regulated by EPA, as authorized by the MPRSA. Other US laws and regulations applicable to ocean dumping of radioactive waste include the Hazardous Materials Transportation Act, The National Environmental Policy Act, The Atomic Energy Act, and the Energy Reorganization Act, along with internal orders for executive departments such as the

  9. 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.

  10. Dismantlement and radioactive waste management of North Korean nuclear facilities

    Microsoft Academic Search

    Jooho Whang; George Thomas Baldwin

    2004-01-01

    One critical aspect of any denuclearization of the Democratic People's Republic of Korea (DPRK) involves dismantlement of its nuclear facilities and management of their associated radioactive wastes. The decommissioning problem for its two principal operational plutonium facilities at Yongbyun, the 5MWe nuclear reactor and the Radiochemical Laboratory reprocessing facility, alone present a formidable challenge. Dismantling those facilities will create radioactive

  11. Dismantlement and Radioactive Waste Management of DPRK Nuclear Facilities

    Microsoft Academic Search

    W. Jooho; G. T. Baldwin

    2005-01-01

    One critical aspect of any denuclearization of the Democratic Peoples Republic of Korea (DPRK) involves dismantlement of its nuclear facilities and management of their associated radioactive wastes. The decommissioning problem for its two principal operational plutonium facilities at Yongbyun, the 5MWe nuclear reactor and the Radiochemical Laboratory reprocessing facility, alone present a formidable challenge. Dismantling those facilities will create radioactive

  12. Studies of radioactive nuclei and their role in the cosmos

    Microsoft Academic Search

    Jeff Blackmon

    2006-01-01

    Producing and accelerating radioactive nuclei in the laboratory provides a unique tool for the study of nuclear reactions involving these isotopes in the energy regime of interest for astrophysics. We briefly review some recent developments with accelerated radioactive ion beams and their impact for astrophysics.

  13. Use plan for demonstration radioactive-waste incinerator

    Microsoft Academic Search

    L. R. Cooley; M. R. McCampbell; J. D. Thompson

    1982-01-01

    The University of Maryland at Baltimore was awarded a grant from the Department of Energy to test a specially modified incinerator to burn biomedical radioactive waste. In preparation for the incinerator, the Radiation Safety Office devised a comprehensive plan for its safe and effective use. The incinerator plan includes a discussion of regulations regarding on-site incineration of radioactive waste, plans

  14. Institutional radioactive wastes. Final summary report. [Nuclear medicine; isotope applications

    Microsoft Academic Search

    R. L. Andersen; L. R. Cooley; T. J. Beck; C. S. Strauss

    1978-01-01

    In 1975, a survey of 686 hospitals, medical schools, and universities was made to determine the physical form, radionuclide content, and volume of radioactive waste shipped from these institutions to commercial land burial sites. The institutions shipped 6,862 M3 of radioactive waste. This volume is increasing by 14% per year, with the largest portion of this volume (62%) and the

  15. Legislator's guide to low-level radioactive waste management

    Microsoft Academic Search

    J. M. Jordan; L. G. Melson

    1981-01-01

    The purpose of the guide is to provide state legislators and their staff with information on low-level radioactive waste management, issues of special concern to the states, and policy options. During 1979, producers of low-level radioactive wastes (LLW) faced a crisis. Two of the three commercial disposal sites were temporarily closed and some LLW producers were running short on storage

  16. 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.

  17. 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.

  18. Combustible radioactive waste treatment by incineration and chemical digestion

    SciTech Connect

    Stretz, L.A.; Crippen, M.D.; Allen, C.R.

    1980-05-28

    A review is given of present and planned combustible radioactive waste treatment systems in the US. Advantages and disadvantages of various systems are considered. Design waste streams are discussed in relation to waste composition, radioactive contaminants by amount and type, and special operating problems caused by the waste.

  19. Environmental radioactivity from natural, industrial, and military sources

    Microsoft Academic Search

    Eisenbud

    1987-01-01

    This document is the third edition of a book generally considered a standard in the field of radioactive materials in the environment. Topics include radiation protection standards, transport mechanisms, terrestrial and aquatic pathways, reprocessing of nuclear fuels, radioactive waste management, the fallout from nuclear explosions, nuclear accidents, and risk assessment. (TEM)

  20. Proteomics of field samples in radioactive Chernobyl area.

    PubMed

    Klubicová, Katarína; Rashydov, Namik M; Hajduch, Martin

    2014-01-01

    Two serious nuclear accidents during the past quarter of a century contaminated large agricultural areas with radioactivity. The remediation and possible recovery of radio-contaminated areas for agricultural purposes require comprehensive characterization of plants grown in such places. Here we describe the quantitative proteomics method that we use to analyze proteins isolated from seeds of plants grown in radioactive Chernobyl zone. PMID:24136546

  1. Radioactive effluents, Portsmouth Gaseous Diffusion Plant, calendar year 1982

    SciTech Connect

    Acox, T.A.; Hary, L.F.; Klein, L.S.

    1983-03-01

    Radioactive discharges from the Portsmouth Gaseous Diffusion Plant are discussed and tabulated. Tables indicate both the location of the discharge and the nuclides discharged. All discharges for 1982 are well below the Radioactive Concentration Guide limits specified in DOE Order 5480.1, Chapter XI. 1 figure.

  2. Present situation of the clinical utilization of radioactive tracers

    NASA Astrophysics Data System (ADS)

    Masi, R.

    1983-10-01

    The utilization of radioactive tracers in Italy with a clinical scope is examined. Geographic distribution of clinical centers, legislation, disposal of radioactive wastes, personnel, equipment available, operation mode and prospectives are discussed. Deficiencies in equipment, personnel and choice of diagnosis methods are shown.

  3. Radioactive satellites: Intact reentry and breakup by debris impact

    Microsoft Academic Search

    P. D. Anz-Meador; A. E. Potter

    1991-01-01

    There is a substantial mass of radioactive material in nuclear reactors or radioisotope thermal generators (RTGs) in orbit about the earth. This paper examines the reentry of intact nuclear fuel cores and RTGs and the fragmentation and subsequent radioactive debris cloud deposition and evolution resulting from the impact of orbital debris upon an orbiting reactor, fuel core, or RTG. To

  4. Characterization of plutonium in Maxey Flats radioactive trench leachates

    Microsoft Academic Search

    J. M. Cleveland; T. F. Rees

    1981-01-01

    Plutonium in trench leachates at the Maxey Flats radioactive waste disposal site exists as dissolved species, primarily complexes of the tetravalent ion with strong organic ligands such as ethylenediaminetetraacetic acid. The complexes are not sorbed well by sediment and are only partly precipitated by ferric hydroxide. These results indicate the importance of isolating radioactive waste from organic matter. 3 tables.

  5. Radioactive Waste Information for 1998 and Record-To-Date

    SciTech Connect

    D. L. French; R. E. Tallman; K. A. Taylor

    1999-07-01

    This document presents detailed data, bar graphs, and pie charts on volume, radioactivity; isotopic identity, origin, and status of radioactive waste for calendar year 1998 at the Idaho National Engineering and Environmental Laboratory (INEEL). The data presented are from the INEEL Integrated Waste Information System.

  6. INEEL Radioactive Liquid Waste Reduction Program

    SciTech Connect

    Tripp, Julia Lynn; Archibald, Kip Ernest; Argyle, Mark Don; Demmer, Ricky Lynn; Miller, Rose Anna; Lauerhass, Lance

    1999-03-01

    Reduction of radioactive liquid waste, much of which is Resource Conservation and Recovery Act (RCRA) listed, is a high priority at the Idaho National Technology and Engineering Center (INTEC). Major strides in the past five years have lead to significant decreases in generation and subsequent reduction in the overall cost of treatment of these wastes. In 1992, the INTEC, which is part of the Idaho National Environmental and Engineering Laboratory (INEEL), began a program to reduce the generation of radioactive liquid waste (both hazardous and non-hazardous). As part of this program, a Waste Minimization Plan was developed that detailed the various contributing waste streams, and identified methods to eliminate or reduce these waste streams. Reduction goals, which will reduce expected waste generation by 43%, were set for five years as part of this plan. The approval of the plan led to a Waste Minimization Incentive being put in place between the Department of Energy–Idaho Office (DOE-ID) and the INEEL operating contractor, Lockheed Martin Idaho Technologies Company (LMITCO). This incentive is worth $5 million dollars from FY-98 through FY-02 if the waste reduction goals are met. In addition, a second plan was prepared to show a path forward to either totally eliminate all radioactive liquid waste generation at INTEC by 2005 or find alternative waste treatment paths. Historically, this waste has been sent to an evaporator system with the bottoms sent to the INTEC Tank Farm. However, this Tank Farm is not RCRA permitted for mixed wastes and a Notice of Non-compliance Consent Order gives dates of 2003 and 2012 for removal of this waste from these tanks. Therefore, alternative treatments are needed for the waste streams. This plan investigated waste elimination opportunities as well as treatment alternatives. The alternatives, and the criteria for ranking these alternatives, were identified through Value Engineering meetings with all of the waste generators. The most promising alternatives were compared by applying weighting factors to each based on how well the alternative met the established criteria. From this information, an overall ranking of the various alternatives was obtained and a path forward recommended.

  7. 77 FR 24746 - Constraint on Releases of Airborne Radioactive Materials to the Environment for Licensees Other...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-04-25

    ...Airborne Radioactive Materials to the Environment for Licensees Other Than Power Reactors...Airborne Radioactive Materials to the Environment for Licensees other than Power Reactors...emissions of radioactive material to the environment. ADDRESSES: Please refer to...

  8. 10 CFR Appendix A to Part 37 - Category 1 and Category 2 Radioactive Materials

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Category 2 Radioactive Materials A Appendix A to Part 37 Energy NUCLEAR REGULATORY COMMISSION PHYSICAL...CATEGORY 2 QUANTITIES OF RADIOACTIVE MATERIAL Pt. 37, App. A Appendix A to Part 37—Category 1 and Category 2 Radioactive...

  9. 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

  10. 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.

  11. Characteristics of Low-Level Radioactive Waste

    SciTech Connect

    Morcos, N.; McConnell, J.W. Jr.; Akers, D.W. (EG and G Idaho, Inc., Idaho Falls, ID (United States))

    1992-06-01

    The objective of the Low-Level Radioactive Waste -- Decontamination Waste Program (FIN A6359), funded by the United States Nuclear Regulatory Commission (NRC), is to provide baseline data on the physical stability and leachability of solidified waste streams generated in the decontamination process of primary coolant systems in operating nuclear power stations. In addition, program work includes characterizing the chemical composition of these waste steams. This report lists the tasks associated with the program, and summarizes the work accomplished and the current status of each task. Also, findings are presented from the analysis of waste samples taken from Peach Bottom, Nine Mile Point, and Oyster Creek, respectively. Section 5 presents the status of the bulged Millstone liner.

  12. RADIOACTIVE IRON AND ITS METABOLISM IN ANEMIA

    PubMed Central

    Hahn, P. F.; Bale, W. F.; Lawrence, E. O.; Whipple, G. H.

    1939-01-01

    Artificially produced radioactive iron is an extremely sensitive agent for use in following iron in the course of its changes in body metabolism, lending itself to studies of absorption, transport, exchange, mobilization, and excretion. The need of the body for iron in some manner determines the absorption of this element. In the normal dog when there is no need for the element, it is absorbed in negligible amounts. In the anemic animal iron is quite promptly assimilated. The plasma is clearly the means of transport of iron from the gastrointestinal tract to its point of mobilization for fabrication into hemoglobin. The speed of absorption and transfer of iron to the red cell is spectacular. The importance of the liver and bone marrow in iron metabolism is confirmed. PMID:19870874

  13. Reduction of INTEC Analytical Radioactive Liquid Wastes

    SciTech Connect

    V. J. Johnson; J. S. Hu; A. G. Chambers

    1999-06-01

    This report details the evaluation of the reduction in radioactive liquid waste from the analytical laboratories sent to the Process Effluent Waste system (deep tanks). The contributors are the Analytical Laboratories Department (ALD), the Waste Operations Department, the laboratories at CPP-637, and natural run off. Other labs were contacted to learn the methods used and if any new technologies had emerged. A waste generation database was made from the current methods in used in the ALD. From this database, methods were targeted to reduce waste. Individuals were contacted on ways to reduce waste. The results are: a new method generating much less waste, several methods being handled differently, some cleaning processes being changed to reduce waste, and changes to reduce chemicals to waste.

  14. Reduction of INTEC Analytical Radioactive Liquid Waste

    SciTech Connect

    Johnson, Virgil James; Hu, Jian Sheng; Chambers, Andrea

    1999-06-01

    This report details the evaluation of the reduction in radioactive liquid waste from the analytical laboratories sent to the Process Effluent Waste system (deep tanks). The contributors are the Analytical Laboratories Department (ALD), the Waste Operations Department, the laboratories at CPP-637, and natural run off. Other labs were contacted to learn of methods used and if any new technologies had emerged. A waste generation database was made from the current methods in use in the ALD. From this database, methods were targeted to reduce waste. Individuals were contacted on ways to reduce waste. The results are: a new method generating much less waste, several methods being handled differently, some cleaning processes being changed to reduce waste, and changes to reduce chemicals to waste.

  15. Submersible purification system for radioactive water

    SciTech Connect

    Abbot, M.L.; Lewis, D.R.

    1989-05-09

    A portable, submersible water purification system for use in a pool of water containing radioactive contamination includes a prefilter for filtering particulates from the water. A resin bed is then provided for removal of remaining dissolved, particulate, organic, and colloidal impurities from the prefiltered water. A sterilizer then sterilizes the water. The prefilter and resin bed are suitably contained and are submerged in the pool. The sterilizer is water tight and located at the surface of the pool. The water is circulated from the pool through the prefilter, resin bed, and sterilizer by suitable pump or the like. In the preferred embodiment, the resin bed is contained within a tank which stands on the bottom of the pool and to which a base mounting the prefilter and pump is attached. An inlet for the pump is provided adjacent the bottom of the pool, while the sterilizer and outlet for the system is located adjacent the top of the pool.

  16. Mathematical modeling of radioactive waste glass melter

    SciTech Connect

    Choi, I.G.

    1990-01-01

    The radioactive waste glass melter used at Savannah River Site (SRS) is a liquid slurry feed joule-heated ceramic melter. The physical nature of a joule-heated meter is complex and involves interactions between electric, thermal, and flow fields. These interactions take place through strongly temperature-dependent glass properties, natural convection, advection, diffusion, and volumetrically distributed joule heating sources. The cold feed on top of heated glass distabilizes the flow field and develops unsteady asymmetric flow motions underneath. Thus waste glass modeling requires solving a full 3-D, unsteady, momentum, energy, and electric equation with temperature-dependent properties. Simulation of noble metal deposit process requires an additional mass diffusion equation that is coupled to the momentum equation through mass advection term. The objective of this paper is to identify critical issues anticipated in the Defense Waste Process Facility (DWPF) melter operation and address how these issues can be resolved with current state-of-the-art mathematical modeling techniques.

  17. Mathematical modeling of radioactive waste glass melter

    SciTech Connect

    Choi, I.G.

    1990-12-31

    The radioactive waste glass melter used at Savannah River Site (SRS) is a liquid slurry feed joule-heated ceramic melter. The physical nature of a joule-heated meter is complex and involves interactions between electric, thermal, and flow fields. These interactions take place through strongly temperature-dependent glass properties, natural convection, advection, diffusion, and volumetrically distributed joule heating sources. The cold feed on top of heated glass distabilizes the flow field and develops unsteady asymmetric flow motions underneath. Thus waste glass modeling requires solving a full 3-D, unsteady, momentum, energy, and electric equation with temperature-dependent properties. Simulation of noble metal deposit process requires an additional mass diffusion equation that is coupled to the momentum equation through mass advection term. The objective of this paper is to identify critical issues anticipated in the Defense Waste Process Facility (DWPF) melter operation and address how these issues can be resolved with current state-of-the-art mathematical modeling techniques.

  18. Annual radioactive waste tank inspection program -- 1993

    SciTech Connect

    McNatt, F.G. Sr.

    1994-05-01

    Aqueous radioactive wastes from Savannah River Site (SRS) separations processes are contained in large underground carbon steel tanks. Inspections made during 1993 to evaluate these vessels, and evaluations based on data accrued by inspections made since the tanks were constructed, are the subject of this report. The 1993 inspection program revealed that the condition of the Savannah River Site waste tanks had not changed significantly from that reported in the previous annual report. No new leaksites were observed. No evidence of corrosion or materials degradation was observed in the waste tanks. However, degradation was observed on covers of the concrete encasements for the out-of-service transfer lines to Tanks 1 through 8.

  19. Natural radioactivity levels in lake sediment samples.

    PubMed

    Ero?lu, Hakan; Kabadayi, Önder

    2013-09-01

    The radioactivity concentrations of nuclides (238)U, (232)Th and (40)K in lake sediments collected from 15 different stations at Alt?nkaya dam lake and 12 different stations at Derbent dam lake in Turkey were measured using high-resolution gamma-ray spectrometry. The measurement was done using a coaxial HPGe detector system coupled to the Ortec-Dspect jr digital MCA system. The average measured activity concentrations of the nuclides (238)U, (232)Th and (40)K were found to be 19.5, 27.7 and 460 Bq kg(-1) in Alt?nkaya dam, whereas the activity concentrations were 18.8, 25.5 and 365 Bq kg(-1) in Derbent dam, respectively. The measured activity concentrations in the present study have been compared with similar measurements from different locations in the world. PMID:23528330

  20. Measurements with radioactive beams at ATLAS.

    SciTech Connect

    Rehm, K. E.

    1998-08-06

    Reactions of interest to nuclear astrophysics have been studied with radioactive beams at the ATLAS accelerator. Using a modified ISOL technique, beams of {sup 18}F (T{sub 1/2} = 110 min) and {sup 56}Ni (T{sub 1/2} = 6.1d) were produced and the reactions {sup 18}F(p,{alpha}){sup 15}O, {sup 18}F(p,{gamma}){sup 19}Ne, and {sup 56}Ni(d,p){sup 57}Ni have been investigated. The results indicate that the {sup 18}F(p,{gamma}) route is a small contributor to the breakout from the hot CNO cycle into the rp process, while the {sup 56}Ni(p,{gamma}){sup 57}Cu rate is about ten times larger than previously assumed.

  1. Radioactive Waste Management Complex performance assessment: Draft

    SciTech Connect

    Case, M.J.; Maheras, S.J.; McKenzie-Carter, M.A.; Sussman, M.E.; Voilleque, P.

    1990-06-01

    A radiological performance assessment of the Radioactive Waste Management Complex at the Idaho National Engineering Laboratory was conducted to demonstrate compliance with appropriate radiological criteria of the US Department of Energy and the US Environmental Protection Agency for protection of the general public. The calculations involved modeling the transport of radionuclides from buried waste, to surface soil and subsurface media, and eventually to members of the general public via air, ground water, and food chain pathways. Projections of doses were made for both offsite receptors and individuals intruding onto the site after closure. In addition, uncertainty analyses were performed. Results of calculations made using nominal data indicate that the radiological doses will be below appropriate radiological criteria throughout operations and after closure of the facility. Recommendations were made for future performance assessment calculations.

  2. Radioactive sample effects on EDXRF spectra

    SciTech Connect

    Worley, Christopher G [Los Alamos National Laboratory

    2008-01-01

    Energy dispersive X-ray fluorescence (EDXRF) is a rapid, straightforward method to determine sample elemental composition. A spectrum can be collected in a few minutes or less, and elemental content can be determined easily if there is adequate energy resolution. Radioactive alpha emitters, however, emit X-rays during the alpha decay process that complicate spectral interpretation. This is particularly noticeable when using a portable instrument where the detector is located in close proximity to the instrument analysis window held against the sample. A portable EDXRF instrument was used to collect spectra from specimens containing plutonium-239 (a moderate alpha emitter) and americium-241 (a heavy alpha emitter). These specimens were then analyzed with a wavelength dispersive XRF (WDXRF) instrument to demonstrate the differences to which sample radiation-induced X-ray emission affects the detectors on these two types of XRF instruments.

  3. Evaluation of radioactive scrap metal recycling

    SciTech Connect

    Nieves, L.A.; Chen, S.Y.; Kohout, E.J.; Nabelssi, B.; Tilbrook, R.W.; Wilson, S.E.

    1995-12-01

    This report evaluates the human health risks and environmental and socio-political impacts of options for recycling radioactive scrap metal (RSM) or disposing of and replacing it. Argonne National Laboratory (ANL) is assisting the US Department of Energy (DOE), Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, in assessing the implications of RSM management alternatives. This study is intended to support the DOE contribution to a study of metal recycling being conducted by the Task Group on Recycling and Reuse of the Organization for Economic Cooperation and Development. The focus is on evaluating the justification for the practice of recycling RSM, and the case of iron and steel scrap is used as an example in assessing the impacts. To conduct the evaluation, a considerable set of data was compiled and developed. Much of this information is included in this document to provide a source book of information.

  4. Determining radioactive aerosol concentrations using a surface radioactive contamination measurement device.

    PubMed

    Cerny, R; Johnova, K; Kozlovska, M; Otahal, P; Vosahlikova, I

    2015-06-01

    For experiments with dispersed radioactive aerosols in a radon-aerosol chamber (RAC), it is desirable to know the activity of the radioactive aerosols applied in the RAC. A COLIBRI TTC survey metre with an SABG-15+ probe (Canberra, USA) was purchased for this purpose. The probe is designed for surface contamination measurements, and it is intended to measure the activity of aerosols deposited on the filters during experiments in the RAC. Since the probe is calibrated in a different geometry, its response in the authors' experimental geometry was simulated by a Monte Carlo method. The authors present a Monte Carlo model using MCNPX and an experimental verification of this probe model. PMID:25979746

  5. DISSOLVED CONCENTRATION LIMITS OF RADIOACTIVE ELEMENTS

    SciTech Connect

    P. Bernot

    2005-07-13

    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 activity is to predict dissolved concentrations or solubility limits for elements with radioactive isotopes (actinium, americium, carbon, cesium, iodine, lead, neptunium, plutonium, protactinium, radium, strontium, technetium, thorium, and uranium) relevant to calculated dose. Model outputs for uranium, plutonium, neptunium, thorium, americium, and protactinium are provided in the form of tabulated functions with pH and log fCO{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. Even though selection of an appropriate set of radionuclides documented in Radionuclide Screening (BSC 2002 [DIRS 160059]) includes actinium, transport of Ac is not modeled in the total system performance assessment for the license application (TSPA-LA) model because of its extremely short half-life. Actinium dose is calculated in the TSPA-LA by assuming secular equilibrium with {sup 231}Pa (Section 6.10); therefore, Ac is not analyzed in this report. The output data from this report are fundamental inputs for TSPA-LA used 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 the actinides discussed in this report. These models cover broad ranges of environmental conditions so 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.

  6. Control of radioactive waste-glass melters

    SciTech Connect

    Bickford, D.F. (Westinghouse Savannah River Co., Aiken, SC (USA)); Hrma, P. (Case Western Reserve Univ., Cleveland, OH (USA)); Bowan, B.W. II (West Valley Nuclear Services Co., Inc., West Valley, NY (USA))

    1990-01-01

    Slurries of simulated high level radioactive waste and glass formers have been isothermally reacted and analyzed to identify the sequence of the major chemical reactions in waste vitrification, their effect on glass production rate, and the development of leach resistance. Melting rates of waste batches have been increased by the addition of reducing agents (formic acid, sucrose) and nitrates. The rate increases are attributable in part to exothermic reactions which occur at critical stages in the vitrification process. Nitrates must be balanced by adequate reducing agents to avoid the formation of persistent foam, which would destabilize the melting process. The effect of foaming on waste glass production rates is analyzed, and melt rate limitations defined for waste-glass melters, based upon measurable thermophysical properties. Minimum melter residence times required to homogenize glass and assure glass quality are much smaller than those used in current practice. Thus, melter size can be reduced without adversely affecting glass quality. Physical chemistry and localized heat transfer of the waste-glass melting process are examined, to refine the available models for predicting and assuring glass production rate. It is concluded that the size of replacement melters and future waste processing facilities can be significantly decreased if minimum heat transfer requirements for effective melting are met by mechanical agitation. A new class of waste glass melters has been designed, and proof of concept tests completed on simulated High Level Radioactive Waste slurry. Melt rates have exceeded 155 kg m{sup {minus}2} h{sup {minus}1} with slurry feeds (32 lb ft{sup {minus}2} h{sup {minus}1}), and 229 kg kg m{sup {minus}2} h{sup {minus}1} with dry feed (47 lb ft{sup {minus}2} h{sup {minus}1}). This is about 8 times the melt rate possible in conventional waste- glass melters of the same size. 39 refs., 5 figs., 9 tabs.

  7. Nuclear Structure Studies with Stable and Radioactive Beams: The SPES radioactive ion beam project

    NASA Astrophysics Data System (ADS)

    de Angelis, G.; SPES collaboration; Prete, G.; Andrighetto, A.; Manzolaro, M.; Corradetti, S.; Scarpa, D.; Rossignoli, M.; Monetti, A.; Lollo, M.; Calderolla, M.; Vasquez, J.; Zafiropoulos, D.; Sarchiapone, L.; Benini, D.; Favaron, P.; Rigato, M.; Pegoraro, R.; Maniero, D.; Calabretta, L.; Comunian, M.; Maggiore, M.; Lombardi, A.; Piazza, L.; Porcellato, A. M.; Roncolato, C.; Bisoffi, G.; Pisent, A.; Galatà, A.; Giacchini, M.; Bassato, G.; Canella, S.; Gramegna, F.; Valiente, J.; Bermudez, J.; Mastinu, P. F.; Esposito, J.; Wyss, J.; Russo, A.; Zanella, S.

    2015-04-01

    A new Radioactive Ion Beam (RIB) facility (SPES) is presently under construction at the Legnaro National Laboratories of INFN. The SPES facility is based on the ISOL method using an UCx Direct Target able to sustain a power of 10 kW. The primary proton beam is provided by a high current Cyclotron accelerator with energy of 35-70 MeV and a beam current of 0.2-0.5 mA. Neutron-rich radioactive ions are produced by proton induced fission on an Uranium target at an expected fission rate of the order of 1013 fissions per second. After ionization and selection the exotic isotopes are re-accelerated by the ALPI superconducting LINAC at energies of 10A MeV for masses in the region A=130 amu. The expected secondary beam rates are of the order of 107 – 109 pps. Aim of the SPES facility is to deliver high intensity radioactive ion beams of neutron rich nuclei for nuclear physics research as well as to be an interdisciplinary research centre for radio-isotopes production for medicine and for neutron beams.

  8. USING STATISTICAL PROCESS CONTROL TO MONITOR RADIOACTIVE WASTE CHARACTERIZATION AT A RADIOACTIVE FACILITY

    SciTech Connect

    WESTCOTT, J.L.; JOCHEN; PREVETTE

    2007-01-02

    Two facilities for storing spent nuclear fuel underwater at the Hanford site in southeastern Washington State are being removed from service, decommissioned, and prepared for eventual demolition. The fuel-storage facilities consist of two separate basins called K East (KE) and K West (KW) that are large subsurface concrete pools filled with water, with a containment structure over each. The basins presently contain sludge, debris, and equipment that have accumulated over the years. The spent fuel has been removed from the basins. The process for removing the remaining sludge, equipment, and structure has been initiated for the basins. Ongoing removal operations generate solid waste that is being treated as required, and then disposed. The waste, equipment and building structures must be characterized to properly manage, ship, treat (if necessary), and dispose as radioactive waste. As the work progresses, it is expected that radiological conditions in each basin may change as radioactive materials are being moved within and between the basins. It is imperative that these changing conditions be monitored so that radioactive characterization of waste is adjusted as necessary.

  9. Directions in low-level radioactive waste management: A brief history of commercial low-level radioactive waste disposal

    SciTech Connect

    Not Available

    1990-10-01

    This report presents a history of commercial low-level radioactive waste management in the United States, with emphasis on the history of six commercially operated low-level radioactive waste disposal facilities. The report includes a brief description of important steps that have been taken during the 1980s to ensure the safe disposal of low-level waste in the 1990s and beyond. These steps include the issuance of Title 10 Code of Federal Regulations Part 61, Licensing Requirements for the Land Disposal of Radioactive Waste, the Low-Level Radioactive Waste Policy Act of 1980, the Low-Level Radioactive Waste Policy Amendments Act of 1985, and steps taken by states and regional compacts to establish additional disposal sites. 42 refs., 13 figs., 1 tab.

  10. Radioactive source term models in a compartment fire code

    SciTech Connect

    Ballinger, M.Y.; Owczarski, P.C.

    1985-04-01

    Models for the release of airborne radioactivity in fires have been developed. These radioactive source term models are used as subroutines in a compartment fire code called FIRIN. Each model is based on release factors developed using information from experiments. Models are developed for the following release mechanisms: burning of contaminated combustible solids; burning of contaminated combustible liquids; heating of noncombustible contaminated surfaces; heating of unpressurized radioactive liquids; pressurized releases of radioactive powders; and pressurized releases of radioactive liquids. The potential for release from these mechanisms was examined in an analysis of three types of fuel cycle facility fires. The types of fires considered were mixed oxide ( MOX) general facility fires, MOX stored combustible waste fires, and solvent extraction fires in fuel reprocessing plants. Input parameters were varied to determine relative importance of release mechanisms and sensitivity of predicted releases to changes in initial conditions. Total radioactive material released ranged from 8 X 10/sup -4/ g of plutonium (0.002% of material at risk) given off in a combustible waste fire to 75 g of mixed isotopes (0.3% of material at risk) given off in a solvent extraction fire. Fuel loading and burn area were the parameters that caused the greatest change in total release of radioactive material. Changes in ventilation rate also made a significant difference in release for overventilated fires, but not for underventilated fires. Work is under way at Battelle Pacific Northwest Laboratory to improve the models for burning of contaminated combustible solids and liquids.

  11. Membrane Treatment of Liquid Salt Bearing Radioactive Wastes

    SciTech Connect

    Dmitriev, S. A.; Adamovich, D. V.; Demkin, V. I.; Timofeev, E. M.

    2003-02-25

    The main fields of introduction and application of membrane methods for preliminary treatment and processing salt liquid radioactive waste (SLRW) can be nuclear power stations (NPP) and enterprises on atomic submarines (AS) utilization. Unlike the earlier developed technology for the liquid salt bearing radioactive waste decontamination and concentrating this report presents the new enhanced membrane technology for the liquid salt bearing radioactive waste processing based on the state-of-the-art membrane unit design, namely, the filtering units equipped with the metal-ceramic membranes of ''TruMem'' brand, as well as the electrodialysis and electroosmosis concentrators. Application of the above mentioned units in conjunction with the pulse pole changer will allow the marked increase of the radioactive waste concentrating factor and the significant reduction of the waste volume intended for conversion into monolith and disposal. Besides, the application of the electrodialysis units loaded with an ion exchange material at the end polishing stage of the radioactive waste decontamination process will allow the reagent-free radioactive waste treatment that meets the standards set for the release of the decontaminated liquid radioactive waste effluents into the natural reservoirs of fish-farming value.

  12. The development of radioactive sample surrogates for training and exercises

    SciTech Connect

    Martha Finck; Bevin Brush; Dick Jansen; David Chamberlain; Don Dry; George Brooks; Margaret Goldberg

    2012-03-01

    The development of radioactive sample surrogates for training and exercises Source term information is required for to reconstruct a device used in a dispersed radiological dispersal device. Simulating a radioactive environment to train and exercise sampling and sample characterization methods with suitable sample materials is a continued challenge. The Idaho National Laboratory has developed and permitted a Radioactive Response Training Range (RRTR), an 800 acre test range that is approved for open air dispersal of activated KBr, for training first responders in the entry and exit from radioactively contaminated areas, and testing protocols for environmental sampling and field characterization. Members from the Department of Defense, Law Enforcement, and the Department of Energy participated in the first contamination exercise that was conducted at the RRTR in the July 2011. The range was contaminated using a short lived radioactive Br-82 isotope (activated KBr). Soil samples contaminated with KBr (dispersed as a solution) and glass particles containing activated potassium bromide that emulated dispersed radioactive materials (such as ceramic-based sealed source materials) were collected to assess environmental sampling and characterization techniques. This presentation summarizes the performance of a radioactive materials surrogate for use as a training aide for nuclear forensics.

  13. Electrodeposition of radioactive rhenium onto stents to prevent restenosis.

    PubMed

    Häfeli, U O; Warburton, M C; Landau, U

    1998-05-01

    Radioactive stents are currently being evaluated for preventing restenosis. A major difficulty to overcome is the need to load any pre-manufactured stents with defined amounts of radioactivity at the time of use. Using stents that are preloaded by the manufacturer is not ideal because the stent length usually differs from the length needed for a specific lesion and the amounts of radioactivity varies widely due to ongoing decay of the source. Thus, we have developed a novel method that allows any currently used stainless steel or tantalum stent to be coated with radioactive rhenium. The method involves placing the stent in a series of rinsing and electroplating solutions, one containing radioactive rhenium (186Re, 188Re, or both). The overall processing time is 15 min and the procedure may be conveniently applied just prior to the stent insertion. The plated stent contains radioactive rhenium in a 1.2 microm-thick cobalt layer, with an outer 2 microm layer of gold. The gold layer gives the radioactive stent excellent radiochemical stability, good bending and biocompatibility properties, and improves stent visibility during fluoroscopy. PMID:9690834

  14. Assessment of public perception of radioactive waste management in Korea.

    SciTech Connect

    Trone, Janis R.; Cho, SeongKyung (Myongji University, Korea); Whang, Jooho (Kyung Hee University, Korea); Lee, Moo Yul

    2011-11-01

    The essential characteristics of the issue of radioactive waste management can be conceptualized as complex, with a variety of facets and uncertainty. These characteristics tend to cause people to perceive the issue of radioactive waste management as a 'risk'. This study was initiated in response to a desire to understand the perceptions of risk that the Korean public holds towards radioactive waste and the relevant policies and policy-making processes. The study further attempts to identify the factors influencing risk perceptions and the relationships between risk perception and social acceptance.

  15. Radioactive beam experiments using the Fragment Mass Analyzer

    SciTech Connect

    Davids, C.N.

    1994-04-01

    The Fragment Mass Analyzer (FMA) is a recoil mass spectrometer that has many potential applications in experiments with radioactive beams. The FMA can be used for spectroscopic studies of nuclei produced in reactions with radioactive beams. The FMA is also an ideal tool for studying radiative capture reactions of astrophysical interest, using inverse kinematics. The FMA has both mass and energy dispersion, which can be used to efficiently separate the reaction recoils from the primary beam. When used with radioactive beams, the FMA allows the recoils from radiative capture reactions to be detected in a low-background environment.

  16. Environmental Radioactivity Study in Surface Sediments of Guacanayabo Gulf (Cuba)

    NASA Astrophysics Data System (ADS)

    Reyes, H.; López-Pino, N.; Rizo, O. Díaz; Bernal, J. L.; D'Alessandro, K.; Padilla, F.; Corrales, Y.; Casanova, O. A.; Gelen, A.; Martínez, Y.; Aguilar, J.; Arado, J. O.; Maidana, N. L.

    2009-06-01

    Sediment samples have been collected in the Guacanayabo gulf located in the southeast Cuba, to determinate the radioactivity levels of 210Pb, 234Th, 214Pb, 137Cs, 232Th and 40K using Low-Background Gamma Spectrometry and to evaluate its impact in the habitat of important marine species for fishery industry. The obtained results show the lowest radioactivity levels determined in Cuban marine environments. The species capture declination in the last years is not originated by radioactive pollution of the zone.

  17. Natural radioactivity contamination problems. Report no. 2. (final)

    SciTech Connect

    Not Available

    1981-09-01

    Levels of naturally occurring radionuclides associated with the bauxite, columbium-tantalum, phosphate, tin, pumice, and titanium mineral extraction industries are reported. Data is also presented on radioactivity measurements in ground water, in selected geothermal waters, and in oil production brines. Radiation protection guidance is provided for uranium recovery from wet-process phosphate plants, for soil contamination limits, and for radiological exposure in natural caves. Dose pathways from incidental uses of naturally occurring radioactive materials are presented. Model state regulations for protecting public health and safety from use and disposal of naturally occurring radioactive material are outlined.

  18. Management of Disused Radioactive Sealed Sources in Egypt - 13512

    SciTech Connect

    Mohamed, Y.T.; Hasan, M.A.; Lasheen, Y.F. [Hot Laboratories and Waste Management Center, Egyptian Atomic Energy Authority, 11787, Cairo (Egypt)] [Hot Laboratories and Waste Management Center, Egyptian Atomic Energy Authority, 11787, Cairo (Egypt)

    2013-07-01

    The future safe development of nuclear energy and progressive increasing use of sealed sources in medicine, research, industry and other fields in Egypt depends on the safe and secure management of disused radioactive sealed sources. In the past years have determined the necessity to formulate and apply the integrated management program for radioactive sealed sources to assure harmless and ecological rational management of disused sealed sources in Egypt. The waste management system in Egypt comprises operational and regulatory capabilities. Both of these activities are performed under legislations. The Hot Laboratories and Waste Management Center HLWMC, is considered as a centralized radioactive waste management facility in Egypt by law 7/2010. (authors)

  19. Radioactive minerals - Multimedias strategies for their divulgation

    NASA Astrophysics Data System (ADS)

    Cabral, João; Gomes, Ana; Aldano, Ana; Fonseca, Pedro; Cabral, Tiago; Nobre, José

    2014-05-01

    The region corresponding to Sortelha-Penalobo - Bendada, located deep in the transition zone between the Hesperian massif and the Cova da Beira in the central part of Portugal, more specifically in the Mountainous region of the province of Beira Alta, county Sabugal. This region is characterized by great mineral wealth combined with geomorphology of recognized landscape value. Under the scientific point of view, this region is the origin of the mineral sabugalite (HAl(UO2)4(PO4)4.16H2O) that was described by the famous American mineralogist Clifford Frondel (1907-2002) in the fifties of the 20th century. Uranium minerals of Sabugal region were also associated with the radioactivity studies made by the well-known French physicist Marie Curie (1867-1934). In 2007, U. Kolitsch et al described the Bendadaite (Fe (AsO4) 2 (OH) 2 • 4H2O), which corresponds to a new mineral from the group arthurite. The mineral wealth of this region is responsible for a rich history of mining and to highlight the importance until the 1990s the extraction of uranium minerals. The main uranium minerals extracted were the tobernite (Cu (UO2) 2 (PO4) 2 • 12 H2O), the metatobernite (Cu (UO2) 2 (PO4) 2 • 8 H 2 O), the autonite (Ca (UO2) 2 (PO4 ) 2 • 12H2O-10) and sabugalite (HAL (UO2) 4 (PO4) 4 16H2O). Due to the high radioactivity of these minerals, their handling becomes infeasible for disclosure purposes. An integrated and multidisciplinary museological strategy aims to access 3D images by QR codes, using multitouch as the primary means of interaction with the user, and can handle even the virtual samples, access various magnifications and enjoy explanations supplied by a mascot, in a fun way. All this framework and geological environment becomes an asset for the scientific, educational and economic development of the region. On the other hand, it has a vital importance in the context of a strategy of forming a geological park, in the point of view of tourism, research and interpretation.

  20. Radioactivity backgrounds in ZEPLIN-III

    NASA Astrophysics Data System (ADS)

    Araújo, H. M.; Akimov, D. Yu.; Barnes, E. J.; Belov, V. A.; Bewick, A.; Burenkov, A. A.; Chepel, V.; Currie, A.; Deviveiros, L.; Edwards, B.; Ghag, C.; Hollingsworth, A.; Horn, M.; Kalmus, G. E.; Kobyakin, A. S.; Kovalenko, A. G.; Lebedenko, V. N.; Lindote, A.; Lopes, M. I.; Lüscher, R.; Majewski, P.; Murphy, A. St. J.; Neves, F.; Paling, S. M.; Pinto da Cunha, J.; Preece, R.; Quenby, J. J.; Reichhart, L.; Scovell, P. R.; Silva, C.; Solovov, V. N.; Smith, N. J. T.; Smith, P. F.; Stekhanov, V. N.; Sumner, T. J.; Thorne, C.; Walker, R. J.

    2012-03-01

    We examine electron and nuclear recoil backgrounds from radioactivity in the ZEPLIN-III dark matter experiment at Boulby. The rate of low-energy electron recoils in the liquid xenon WIMP target is 0.75 ± 0.05 events/kg/day/keV, which represents a 20-fold improvement over the rate observed during the first science run. Energy and spatial distributions agree with those predicted by component-level Monte Carlo simulations propagating the effects of the radiological contamination measured for materials employed in the experiment. Neutron elastic scattering is predicted to yield 3.05 ± 0.5 nuclear recoils with energy 5-50 keV per year, which translates to an expectation of 0.4 events in a 1 yr dataset in anti-coincidence with the veto detector for realistic signal acceptance. Less obvious background sources are discussed, especially in the context of future experiments. These include contamination of scintillation pulses with Cherenkov light from Compton electrons and from ? activity internal to photomultipliers, which can increase the size and lower the apparent time constant of the scintillation response. Another challenge is posed by multiple-scatter ?-rays with one or more vertices in regions that yield no ionisation. If the discrimination power achieved in the first run can be replicated, ZEPLIN-III should reach a sensitivity of ˜1 × 10-8pb · yr to the scalar WIMP-nucleon elastic cross-section, as originally conceived.

  1. Use of radioactive phosphorus in haematology.

    PubMed

    Roberts, B E; Smith, A H

    1997-09-01

    Following the development of the cyclotron in 1932, radio-isotopes became available for use in medicine both as tracer substances and therapeutic agents. The father of nuclear medicine, Dr J. H. Lawrence, pioneered their use in a range of disease states and found that radio-isotopes were of enormous value in the diagnosis and treatment of haemopoetic disease, particularly the myeloproliferative disorders. Radioactive phosphorus 32P emerged as the radio-isotope of choice for the myelosuppressive treatment of myeloproliferative disorders. This article also describes the use of radio-isotopes in the treatment of other disorders: chronic myeloid leukaemia, chronic lymphocytic leukaemia and myeloma, work that is now largely forgotten. All myeloproliferative disorders may evolve without treatment into myelodysplastic syndrome or blast-cell transformation. It is accepted that life is prolonged in myeloproliferative disorders treated with 32P or alkylating agents, yet both are leukaemogenic. The ideal form of treatment for polycythaemia vera is unknown and will remain so, for patients with this disorder often outlive their physician and achieve 90% of normal life expectation. 32P remains the treatment of choice for elderly patients with polycythaemia vera. PMID:9370045

  2. European Measurement Comparisons of Environmental Radioactivity

    NASA Astrophysics Data System (ADS)

    Wätjen, Uwe

    2008-08-01

    The scheme of European measurement comparisons to verify radioactivity monitoring in the European Union is briefly explained. After a review of comparisons conducted during the years 1990, the approach of IRMM organising these comparisons since 2003 is presented. IRMM is providing comparison samples with a reference value traceable to the SI units and which is fully documented to all participants and national authorities after completion of the comparison. The sample preparation and determination of traceable reference values at IRMM, the sample treatment and measurement in the participating laboratories, as well as the evaluation of comparison results are described in some detail using the example of an air filter comparison. The results of a comparison to determine metabolised 40K, 90Sr and 137Cs in milk powder are presented as well. The necessary improvements in the estimation of measurement uncertainty by the participating laboratories are discussed. The performance of individual laboratories which have participated in at least four comparison exercises over the years is studied in terms of observable trends.

  3. Closing Radioactive Waste Tanks in South Carolina

    SciTech Connect

    Newman, J.L.

    2000-08-29

    The Savannah River Site (SRS) is owned by the US Department of Energy (DOE) and is operated by the Westinghouse Savannah River Company (WSRC). Since the early 1950s, the primary mission of the site has been to produce nuclear materials for national defense. The chemical separations processes used to recover uranium and plutonium from production reactor fuel and target assemblies in the chemical separations area at SRS generated liquid high-level radioactive waste. This waste, which now amounts to approximately 34 million gallons, is stored in underground tanks in the F- and H-Areas near the center of the site. DOE is closing the High Level Waste (HLW) tank systems, which are permitted by SCDHEC under authority of the South Carolina Pollution Control Act (SCPCA) as wastewater treatment facilities, in accordance with South Carolina Regulation R.61-82, ''Proper Closeout of Wastewater Treatment Facilities''. To date, two HLW tank systems have been closed in place. Closure of these tanks is the first of its kind in the US. This paper describes the waste tank closure methodologies, standards and regulatory background.

  4. [Polonium: the radioactive killer from tobacco smoke].

    PubMed

    Zagà, Vincenzo; Gattavecchia, Enrico

    2008-01-01

    Among all carcinogenic substances contained in tobacco smoke, Polonium 210 (Po-210), with a half-life of 138 days, is one of the most dangerous, by exerting a devastating, chronic, slow and progressive carcinogenesis activity. The main source of Po-210 in tobacco is represented by fertilizers (polyphosphates) containing radium-226 (Ra-222) which decades to plumb 210 (Pb-210). Through the thricomes Pb-210 is concentrated in the tobacco leaves, where it turns to Po-210, which at the cigarette combustion temperature (800-900 degrees C) reaches the gaseous state and it is absorbed by the micro particles released into tobacco smoke. Thus, smoke becomes radioactive in both its gaseous and corpuscular components and reaches the airways, where, particularly at the branches level and together with other substances, it exerts its carcinogenic activity, especially in those subjects with impaired respiratory mucosal clearance. The carcinogenic risk/one year lifetime of a smoker of 20 cigarettes per day is equivalent to that of undertaking 300 chest x-rays. It is calculated that Po-210 may be independently responsible of 4 lung cancers every 10,000 smokers. During cigarette's combustion, tobacco smoke is also released in the air, contributing to serious health risks for those exposed to passive smoke. PMID:19186689

  5. Radioactive contamination incidents involving protective clothing

    SciTech Connect

    Reichelt, R.; Clay, M.; Eichorst, J.

    1996-10-01

    The study focuses on incidents at Department of Energy (DOE) facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work; (2) working conditions; (3) type of anti-contamination (anti-C) material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning (D&D) projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-C clothing most often identified was cotton or water-resistant, disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled.

  6. Radioactive contamination incidents involving protective clothing

    SciTech Connect

    Reichelt, R.A.; Clay, M.E.; Eichorst, A.J. [Los Alamos National Lab., NM (United States)

    1998-01-01

    The study focuses on incidents at Department of Energy facilities involving the migration of radioactive contaminants through protective clothing. The authors analyzed 68 occurrence reports for the following factors: (1) type of work, (2) working conditions, (3) type of anti-contamination material; (4) area of body or clothing contaminated; and (5) nature of spread of contamination. A majority of reports identified strenuous work activities such as maintenance, construction, or decontamination and decommissioning projects. The reports also indicated adverse working conditions that included hot and humid or cramped work environments. The type of anti-contamination clothing most often identified was cotton or water-resistant disposable clothing. Most of the reports also indicated contaminants migrating through perspiration-soaked areas, typically in the knees and forearms. On the basis of their survey, the authors recommend the use of improved engineering controls and resilient, breathable, waterproof protective clothing for work in hot, humid, or damp areas where the possibility of prolonged contact with contamination cannot be easily avoided or controlled. 1 ref., 6 figs., 1 tab.

  7. European Measurement Comparisons of Environmental Radioactivity

    SciTech Connect

    Waetjen, Uwe [European Commission, Joint Research Centre, Institute for Reference Materials and Measurements (IRMM), Retieseweg 111, B-2440 Geel (Belgium)

    2008-08-14

    The scheme of European measurement comparisons to verify radioactivity monitoring in the European Union is briefly explained. After a review of comparisons conducted during the years 1990, the approach of IRMM organising these comparisons since 2003 is presented. IRMM is providing comparison samples with a reference value traceable to the SI units and which is fully documented to all participants and national authorities after completion of the comparison. The sample preparation and determination of traceable reference values at IRMM, the sample treatment and measurement in the participating laboratories, as well as the evaluation of comparison results are described in some detail using the example of an air filter comparison. The results of a comparison to determine metabolised {sup 40}K, {sup 90}Sr and {sup 137}Cs in milk powder are presented as well. The necessary improvements in the estimation of measurement uncertainty by the participating laboratories are discussed. The performance of individual laboratories which have participated in at least four comparison exercises over the years is studied in terms of observable trends.

  8. The production of accelerated radioactive ion beams

    SciTech Connect

    Olsen, D.K.

    1993-11-01

    During the last few years, substantial work has been done and interest developed in the scientific opportunities available with accelerated radioactive ion beams (RIBs) for nuclear physics, astrophysics, and applied research. This interest has led to the construction, development, and proposed development of both first- and second-generation RIB facilities in Asia, North America, and Europe; international conferences on RIBs at Berkeley and Louvain-la-Neuve; and many workshops on specific aspects of RIB production and science. This paper provides a discussion of both the projectile fragmentation, PF, and isotope separator on-line, ISOL, approach to RIB production with particular emphasis on the latter approach, which employs a postaccelerator and is most suitable for nuclear structure physics. The existing, under construction, and proposed facilities worldwide are discussed. The paper draws heavily from the CERN ISOLDE work, the North American IsoSpin Laboratory (ISL) study, and the operating first-generation RIB facility at Louvain-la-Neuve, and the first-generation RIB project currently being constructed at ORNL.

  9. [Decorporation agents for internal radioactive contamination].

    PubMed

    Ohmachi, Yasushi

    2015-01-01

    When radionuclides are accidentally ingested or inhaled, blood circulation or tissue/organ deposition of the radionuclides causes systemic or local radiation effects. In such cases, decorporation therapy is used to reduce the health risks due to their intake. Decorporation therapy includes reduction and/or inhibition of absorption from the gastrointestinal tract, isotopic dilution, and the use of diuretics, adsorbents, and chelating agents. For example, penicillamine is recommended as a chelating agent for copper contamination, and diethylene triamine pentaacetic acid is approved for the treatment of internal contamination with plutonium. During chelation therapy, the removal effect of the drugs should be monitored using a whole-body counter and/or bioassay. Some authorities, such as the National Council on Radiation Protection and Measurements and International Atomic Energy Agency, have reported recommended decorporation agents for each radionuclide. However, few drugs are approved by the US Food and Drug Administration, and many are off-label-use agents. Because many decontamination agents are drugs that have been available for a long time and have limited efficacy, the development of new, higher-efficacy drugs has been carried out mainly in the USA and France. In this article, in addition to an outline of decorporation agents for internal radioactive contamination, an outline of our research on decorporation agents for actinide (uranium and plutonium) contamination and for radio-cesium contamination is also presented. PMID:25832835

  10. ConcepTest: Calculating Rock Age from Parent Radioactive Isotope

    NSDL National Science Digital Library

    A radioactive (parent) isotope of element X is discovered in different amounts in four rocks (A, B, C, D) of the same composition. Which rock has the oldest calculated age? a. 15% of element X remains in Rock A b. ...

  11. Detecting and Locating Radioactive Signals with Wireless Sensor Networks

    E-print Network

    Zhang, Tonglin

    as a hidden nuclear weapon held by nuclear terrorists or as a leak of nuclear radioactive materials at a unit- nications and electronics have enabled the development of low cost, lower-power, multifunctional sensor

  12. RADIOACTIVE ELEMENT REMOVAL FROM WATER USING GRAPHENE OXIDE (GO) 

    E-print Network

    Concklin, Joshua Paul

    2013-12-19

    and uranium. Naturally occurring radioactive materials (NORM) are abundant throughout the earth's crust. Human manipulation of NORM for economic ends, such as mining, ore processing, fossil fuel extraction, and commercial aviation, may lead to what is known...

  13. Radioactive Waste Management in Non-Nuclear Countries - 13070

    SciTech Connect

    Kubelka, Dragan; Trifunovic, Dejan [SORNS, Frankopanska 11, HR-10000 Zagreb (Croatia)] [SORNS, Frankopanska 11, HR-10000 Zagreb (Croatia)

    2013-07-01

    This paper challenges internationally accepted concepts of dissemination of responsibilities between all stakeholders involved in national radioactive waste management infrastructure in the countries without nuclear power program. Mainly it concerns countries classified as class A and potentially B countries according to International Atomic Energy Agency. It will be shown that in such countries long term sustainability of national radioactive waste management infrastructure is very sensitive issue that can be addressed by involving regulatory body in more active way in the infrastructure. In that way countries can mitigate possible consequences on the very sensitive open market of radioactive waste management services, comprised mainly of radioactive waste generators, operators of end-life management facilities and regulatory body. (authors)

  14. The Study of Soil Radioactivity around Central Region of Mongolia

    SciTech Connect

    Erkhembayar, Ts.; Norov, N.; Khuukhenkhuu, G.; Odsuren, M. [Nuclear Research Center, National University of Mongolia (Mongolia)

    2009-03-31

    The specific radioactivity of {sup 238}U, {sup 232}Th, {sup 40}K were measured in soil samples around some provinces of Central region in Mongolia using the HP-Ge gamma-spectrometer. The effective equivalent dose was determined.

  15. Geological Problems in Radioactive Waste Isolation: Second Worldwide Review

    E-print Network

    2010-01-01

    are mainly waste paper, clothes, plastics, wood materials,Radioactive waste dis- posal into a plastic clay formation -waste," The next step was to demonstrate that it was technically feasible to build a repository in such a plastic

  16. The basics in transportation of low-level radioactive waste

    SciTech Connect

    Allred, W.E.

    1998-06-01

    This bulletin gives a basic understanding about issues and safety standards that are built into the transportation system for radioactive material and waste in the US. An excellent safety record has been established for the transport of commercial low-level radioactive waste, or for that matter, all radioactive materials. This excellent safety record is primarily because of people adhering to strict regulations governing the transportation of radioactive materials. This bulletin discusses the regulatory framework as well as the regulations that set the standards for packaging, hazard communications (communicating the potential hazard to workers and the public), training, inspections, routing, and emergency response. The excellent safety record is discussed in the last section of the bulletin.

  17. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am - the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting ...

  18. Controlled Containment, Radioactive Waste Management in the Netherlands

    SciTech Connect

    Codee, H.

    2002-02-26

    All radioactive waste produced in The Netherlands is managed by COVRA, the central organization for radioactive waste. The Netherlands forms a good example of a country with a small nuclear power program which will end in the near future. However, radioisotope production, nuclear research and other industrial activities will continue to produce radioactive waste. For the small volume, but broad spectrum of radioactive waste, including TENORM, The Netherlands has developed a management system based on the principles to isolate, to control and to monitor the waste. Long term storage is an essential element of the management system and forms a necessary step in the strategy of controlled containment that will ultimately result in final removal of the waste. Since the waste will remain retrievable for long time new technologies and new disposal options can be applied when available and feasible.

  19. Hydrocolloid-stabilized magnetite for efficient removal of radioactive phosphates.

    PubMed

    Vellora Thekkae Padil, Vinod; Rouha, Michael; Cerník, Miroslav

    2014-01-01

    Liquid radioactive waste is a common by-product when using radioactive isotopes in research and medicine. Efficient remediation of such liquid waste is crucial for increasing safety during the necessary storage of the material. Herein, we present a novel Gum Karaya stabilized magnetite for the efficient removal of radioactive phosphorus (32)P from liquid radioactive waste. This environmentally friendly material is well suited to be used as a nanohydrogel for the removal of liquid waste, which can then be stored in a smaller space and without the risk of the spills inherent to the initial liquid material. The maximum adsorption capacity of the GK/M in this study was found to be 15.68 GBq/g. We present a thorough morphological characterization of the synthesised GK/M, as well as a discussion of the possible phosphorus adsorption mechanisms. PMID:24696854

  20. Categorization of In-use Radioactive Sealed Sources in Egypt

    SciTech Connect

    Hasan, M.A.; Mohamed, Y.T. [Egyptian Atomic Energy Authority, P.O. Box 13759, Inshas (Egypt); El Haleim, K.A. [Minstry of Health and populations, El 0khsheed St, Maneal El Roda (Egypt)

    2006-07-01

    Radioactive sealed sources have widespread applications in industry, medicine, research and education. While most sources are of relatively low activity, there are many of medium or very high activity. The mismanagement of high activity sources is responsible for most of the radiological accidents that result in loss of life or disabling injuries. Because of the variety of applications and activities of radioactive sources, a categorization system is necessary so that the controls that are applied to the sources are adequate with its radiological risk. The aim of this work is to use the international Atomic Energy Agency (IAEA) categorization system to provide a simple, logical system for grading radioactive sealed sources in Egypt. The categorizations of radioactive sealed sources are based on their potential to cause harm to human health. This study revealed that total of 1916 sources have been used in Egypt in the different applications with a total activity of 89400 Ci according to available data in October 2005. (authors)

  1. Formation of nuclear molecules in cluster radioactivity on interpretation of the cluster radioactivity mechanism

    NASA Astrophysics Data System (ADS)

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

    2013-05-01

    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.

  2. Environmental radioactivity levels in the Cumberland River at the Hartsville Nuclear Project site, 1975-1982

    SciTech Connect

    Not Available

    1985-07-01

    Samples of surface water taken from the Cumberland River during the period from 1975 through 1982 exhibited radioactivity levels less than 1% of the maximum permissible concentrations published by the Nuclear Regulatory Commission. Radioactivity concentrations reported herein are typical of natural radioactivity levels with slight indications of influences from fallout of radioactivity from atmospheric nuclear weapons testing.

  3. Radioactive waste management information for 1996 and record-to-date

    SciTech Connect

    French, D.L.; Lisee, D.J.; Taylor, K.A.

    1997-07-01

    This document presents detailed data, bar graphs, and pie charts on volume, radioactivity, isotopic identity, origin, and status of radioactive waste for calendar year 1996. It also summarizes the radioactive waste data records compiled from 1952 to present for the Idaho National Engineering and Environmental Laboratory (INEEL). The data presented are from the INEEL Radioactive Waste Management Information System.

  4. Sensor Analytics: Radioactive gas Concentration Estimation and Error Propagation

    SciTech Connect

    Anderson, Dale N.; Fagan, Deborah K.; Suarez, Reynold; Hayes, James C.; McIntyre, Justin I.

    2007-04-15

    This paper develops the mathematical statistics of a radioactive gas quantity measurement and associated error propagation. The probabilistic development is a different approach to deriving attenuation equations and offers easy extensions to more complex gas analysis components through simulation. The mathematical development assumes a sequential process of three components; I) the collection of an environmental sample, II) component gas extraction from the sample through the application of gas separation chemistry, and III) the estimation of radioactivity of component gases.

  5. The Dating Game: Radioactive Half-Life and Dating Techniques

    NSDL National Science Digital Library

    Hillary Tulley

    In this lab activity using M&M candy, students will explore the concepts of radioactive decay and dating. Students generate a radioactive decay table to simplify the math, use their data to plot a decay graph, develop the concept of half-life, and then use the graph to find the age of a mummified seal in Wright Valley, Antarctica. In a follow-up exercise, students will solve a mysterious Arctic murder.

  6. Environmental Radioactivity Study in Surface Sediments of Guacanayabo Gulf (Cuba)

    Microsoft Academic Search

    H. Reyes; N. López-Pino; O. Díaz Rizo; J. L. Bernal; K. D'Alessandro; F. Padilla; Y. Corrales; O. A. Casanova; A. Gelen; Y. Martínez; J. Aguilar; J. O. Arado; N. L. Maidana

    2009-01-01

    Sediment samples have been collected in the Guacanayabo gulf located in the southeast Cuba, to determinate the radioactivity levels of 210Pb, 234Th, 214Pb, 137Cs, 232Th and 40K using Low-Background Gamma Spectrometry and to evaluate its impact in the habitat of important marine species for fishery industry. The obtained results show the lowest radioactivity levels determined in Cuban marine environments. The

  7. Radioactive effluents, Portsmouth Uranium Enrichment Complex, calendar year 1983

    SciTech Connect

    Acox, T.A.; Klein, L.S.

    1984-03-01

    Radioactive discharges from the Portsmouth Uranium Enrichment Complex are discussed and tabulated. Tables indicate both the location of the discharge and the nuclides discharged. Routine discharges for 1983 are well below the Radioactive Concentration Guide limits specified in DOE Order 5480.1, Chapter XI. There was, however, an unplanned release in December from the X-326 Building Side Purge which exceeded the limits. 1 figure.

  8. Dose assessment for radioactive contamination of a child 

    E-print Network

    Kowalczik, Jeffrey Aaron

    2009-05-15

    DOSE ASSESSMENT FOR RADIOACTIVE SKIN CONTAMINATION OF A CHILD A Thesis by JEFFREY AARON KOWALCZIK Submitted to the Office of Graduate Studies of Texas A&M University in partial fulfillment of the requirements for the degree... of MASTER OF SCIENCE May 2008 Major Subject: Health Physics DOSE ASSESSMENT FOR RADIOACTIVE SKIN CONTAMINATION OF A CHILD A Thesis by JEFFREY AARON KOWALCZIK Submitted to the Office of Graduate Studies of Texas A&M University...

  9. Evaluation of the radioactivity in concrete from accelerator facilities

    Microsoft Academic Search

    Q. B. Wang; K. Masumoto; K. Bessho; H. Matsumura; T. Miura; T. Shibata

    2007-01-01

    For evaluation of radioactivity induced in the concrete samples from accelerator facilities, the residual radioactivity in\\u000a concrete sample, collected from seven accelerator facilities, was determined by ?-ray spectrometry. The tritium was extracted\\u000a by the heating method using an IR furnace, and measured with a liquid scintillation counter. It was found that the major radioisotopes\\u000a activated mainly by neutrons in the

  10. Method for fabricating thin californium-containing radioactive source wires

    DOEpatents

    Gross, Ian G; Pierce, Larry A

    2006-08-22

    A method for reducing the cross-sectional diameter of a radioactive californium-containing cermet wire while simultaneously improving the wire diameter to a more nearly circular cross section. A collet fixture is used to reduce the wire diameter by controlled pressurization pulses while simultaneously improving the wire cross-sectional diameter. The method is especially suitable for use in hot cells for the production of optimized cermet brachytherapy sources that contain large amounts of radioactive californium-252.

  11. Experimental results with endovascular irradiation via a radioactive stent

    Microsoft Academic Search

    Andrew J. Carter; John R. Laird

    1996-01-01

    Purpose: The objective of this article is to describe the methods used to manufacture a radioactive stent and to review the experimental data on this therapy designed to improve arterial patency rates after stent placement.Materials and Methods: Surface activation in a cyclotron and ion implantation techniques are used to render commercially available vascular stents radioactive. ?-Particle-emitting stents, most commonly 32P,

  12. Injection of Radioactivities into the Forming Solar System

    E-print Network

    Harri A. T. Vanhala; Alan P. Boss

    2001-11-08

    Meteorite studies have revealed the presence of short-lived radioactivities in the early solar system. The current data suggests that the origin of at least some of the radioactivities requires contribution from recent nucleosynthesis at a stellar site. This sets a strict time limit on the time available for the formation of the solar system and argues for the theory of the triggered origin of the solar system. According to this scenario, the formation of our planetary system was initiated by the impact of an interstellar shock wave on a molecular cloud core. The shock wave originated from a nearby explosive stellar event and carried with it radioactivities produced in the stellar source. In addition to triggering the collapse of the molecular cloud core, the shock wave also deposited some of the freshly synthesized radioactivities into the collapsing system. The radioactivities were then incorporated into the first solar system solids, in this manner leaving a record of the event in the meteoritic material. The viability of the scenario can be investigated through numerical simulations studying the processes involved in mixing shock wave material into the collapsing system. The high-resolution calculations presented here show that injection occurs through Rayleigh-Taylor instabilities, the injection efficiency is approximately 10%, and temporal and spatial heterogeneities in the abundances of the radioactivities existed at the time of their arrival in the forming solar system.

  13. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2013 CFR

    2013-01-01

    ...Radioactive Material Posting and Labeling Requirements E Appendix E to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. E Appendix E to Part 835—Values for Establishing...

  14. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2014 CFR

    2014-01-01

    ...Radioactive Material Posting and Labeling Requirements E Appendix E to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. E Appendix E to Part 835—Values for Establishing...

  15. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...Radioactive Material Posting and Labeling Requirements E Appendix E to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. E Appendix E to Part 835—Values for Establishing...

  16. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...Radioactive Material Posting and Labeling Requirements E Appendix E to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. E Appendix E to Part 835—Values for Establishing...

  17. 10 CFR Appendix E to Part 835 - Values for Establishing Sealed Radioactive Source Accountability and Radioactive Material Posting...

    Code of Federal Regulations, 2012 CFR

    2012-01-01

    ...Radioactive Material Posting and Labeling Requirements E Appendix E to Part 835 Energy DEPARTMENT OF ENERGY OCCUPATIONAL RADIATION PROTECTION Pt. 835, App. E Appendix E to Part 835—Values for Establishing...

  18. A radioactive ion beam facility using photofission

    NASA Astrophysics Data System (ADS)

    Diamond, William T.

    1999-08-01

    Use of a high-power electron linac as the driver accelerator for a Radioactive Ion Beam (RIB) facility is proposed. An electron beam of 30 MeV and 100 kW can produce nearly 5×10 13 fissions/s from an optimized 235U target and about 60% of this from a natural uranium target. An electron beam can be readily transmitted through a thin window at the exit of the accelerator vacuum system and transported a short distance through air to a water-cooled Bremsstrahlung-production target. The Bremsstrahlung radiation can, in turn, be transported through air to the isotope-production target. This separates the accelerator vacuum system, the Bremsstrahlung target and the isotope-production target, reducing remote handling problems. The electron beam can be scanned over a large target area to reduce the power density on both the Bremsstrahlung and isotope-production targets. These features address one of the most pressing technological challenges of a high-power RIB facility, namely the production of high yields of neutron-rich ions with reasonable power density in the target. The cost of an electron linac of the required specifications, including the facility shielding, is significantly less than the cost of any other primary-beam accelerator that could produce a comparable fission yield. A high-power electron linac could also be used with a multifoil helium-jet target. A large number of thin uranium foils could be irradiated with the scanned Bremsstrahlung beam and the fission fragments captured in aerosol-loaded helium and transported to an ion source that is well removed from the intense radiation fields of the primary target. The fission yield would be less than 1% of that available from a thick target, but this approach might be the easiest technical solution to obtain useable yields with manageable radiation-safety problems.

  19. Thyroid cancer following exposure to radioactive iodine.

    PubMed

    Robbins, J; Schneider, A B

    2000-04-01

    The thyroid gland is one of the most sensitive organs for radiation-induced oncogenesis and the magnitude of the risk from external radiation is well understood. This is not the case for internal radiation derived from the radioiodines, a matter of practical importance because of medical use and potential accidental exposure. This article reviews current knowledge derived from the follow-up of patients receiving diagnostic or therapeutic 131I and populations exposed to radioactive fallout. The latter includes the nuclear power station accident at Chernobyl and the results of atomic bomb development and testing at Hanford, the Nevada Test Site and the Marshall Islands. The most cogent information comes from Chernobyl where an epidemic of childhood thyroid cancer has followed exposure to radioiodine that was mainly 131I. Although much has been learned from this experience about the nature of radioiodine induced thyroid cancer in young children, the reconstruction of thyroid radiation doses is too preliminary to provide accurate knowledge of the risk in comparison to that from external radiation. In the Marshall Islands, much of the exposure was from short-lived radioiodines as well as external radiation, obviating the possibility to determine the risk from 131I. Exposure to 131I in the continental United States from atomic bomb testing is expected to have caused some thyroid cancers, but only in the immediate vicinity of the Nevada Test Site has any evidence of radiation-induced thyroid neoplasms been adduced. This evidence is minimally significant statistically, and not significant for thyroid cancer per se. Medical use of radioiodine has not been observed to cause thyroid cancer but very few of the patients studied were young children, the group most sensitive to thyroid radiation. Despite these limitations, this information is sufficient to make some suggestions concerning protective measures in the case of nuclear accidents and the follow up of individuals who have been exposed. PMID:11705004

  20. Radioactive Elements in Soils of Siberia (Russia)

    NASA Astrophysics Data System (ADS)

    Baranovskaya, N. V.; Rikhvanov, L. P.; Matveenko, I. N.; Strakhovenko, V. D.; Malikova, I. N.; Shcherbakov, B. L.; Sukhorukov, F. V.; Aturova, V. P.

    2012-04-01

    The Center of State Sanitary and Epidemiological Surveillance Department in Krasnoyarsk Territory, Krasnoyarsk In the course of long-term research a great deal of information on the content of natural and artificial radionuclides in soils of the Siberian regions has been obtained and summarized (Altai and Krasnoyarsk Territories, Altai Republic, Buryatia, Yakutia, Khakassia, Irkutsk, Novosibirsk, Tomsk Oblasts and a number of other Siberian regions). The content level of U(Ra), Th and K in soil of studied areas is within the range of values obtained for soil of other areas of Russia and the world and defined, first of all, by radioactivity of parent rocks. The authors have studied the total level of specific activity for 137Cs most completely in soils of different Siberian regions. The maximum density of such sites with global fallouts (nuclear air explosions in Novaya Zemlya, Lop Nor, Semipalatinsk etc.) is typical for the areas of Altai Territory and Buryatia Republic. Elevated level of radiocesium (to 1000 and more than Bq/kg) is characteristic for the sites adjacent to the area of NFP (Seversk, Zheleznogorsk). Our data obtained in determination of plutonium in soils of different Siberian regions excess remarkably its background accepted for Siberia. Particularly high accumulation levels of Pu in soil were observed in the zones of NFP operation (Seversk, Tomsk Oblast; Zheleznogorsk, Krasnoyarsk Territory, in the sites of accidents fallouts at underground nuclear explosions in Sakha Republic (Yakutia). Abnormally high ratio of 238Pu/239,240Pu in soils of Sakha republic, Aginsk Buryatia Autonomous District, Krasnoyarsk Territory has engaged our attention.

  1. Attempts to develop radioactive anticancer drugs

    SciTech Connect

    Mitchell, J.S.; Brown, I.; Chir, B.; Carpenter, R.N.

    1983-01-01

    Since 1953, attempts have been made to develop radioactive drugs. Preparations of tritiated menadiol sodium diphosphate (T-MNDP) of high specific activity showed a definite, though limited, but sometimes useful effect in the treatment of certain patients with advanced tumors, especially adenocarcinoma of the colon and of the pancreas and malignant melanoma of the skin. The next step was to use a much more effective isotope. 6-/sup 125/I-iodo-2-methyl-1,4-naphthoquinol bis (diammonium phosphate) - abbreviated 6-/sup 125/I-iodo-MNDP - has been synthesized, and in laboratory studies appears more promising. /sup 125/I provides radiations which behave predominately like high LET radiation, despite the accompanying X and gamma radiations. The astatine analogue, 6-/sup 211/At-astato-2-methyl-1,4-naphthoquinol bis (disodium phosphate) has also been synthesized. Confirming and greatly extending the earlier findings with T-MNDP, in vitro experiments showed that 6-/sup 125/I-iodo-MNDP is concentrated selectively in the cells of some human malignant tumors by a factor of about 15 to 20 or more in relation to the cells of normal origin that were studied. Macrodosimetric considerations and comparison with clinical treatments with T-MNDP suggest practical dosage. A typical treatment for a patient of body weight 70 kg with localized inoperable carcinoma of the colon could be 8 intravenous injections each of approximately 120mCi of 6-/sup 125/I-iodo-MNDP to a toal of 0.97 Ci in 25 days. Risks of late carcinogenesis and leukemogenesis are calculated to be less than 1%. Clinical indications are discussed briefly. Animal experiments are in progress and further preclinical studies are required.

  2. In situ vitrification pilot-scale radioactive test

    SciTech Connect

    Timmerman, C.L.; Oma, K.H.

    1984-10-01

    Pacific Northwest Laboratory (PNL) is developing in situ vitrification (ISV) as an in-place stabilization technique for selected liquid radioactive waste disposal sites. The process melts the wastes and surrounding soil to produce a durable glass and crystalline waste form. These ISV process development testing and evaluation studies are being conducted for the US Department of Energy. The results of an ISV pilot-scale test conducted in June of 1983 in which soils contaminated with actual radioactive transuranic and mixed fission product elements were vitrified are discussed. The primary objectives of the radioactive test were to: demonstrate containment and confinement of the radioactive material; verify equipment performance of the power and off-gas systems; identify losses to the off-gas system; and characterize the behavior of the radioactive material in the vitrified soil. The test successfully demonstrated the processing containment of radionuclides both within the vitrified mass and in the off-gas system. No environmental release of radioactive material was measured during testing operations. The vitrified soil had a greater than 99% retention of all radionuclides. Losses to the off-gas system varied from less than or equal to 0.03% for particulate materials (plutonium and strontium) to 0.8% for cesium which is a more volatile element. The off-gas system effectively contained both volatile and entrained radioactive materials. Analysis of the vitrified soil revealed that all radionuclides were distributed throughout the vitrified zone, some more uniformly than others. No migration of radionuclides outside the vitrification zone occurred, as indicated by analysis of soil samples from around the block. Previous waste form leaching studies indicate an acceptable durability of the ISV product. 8 references, 34 figures, 8 tables.

  3. The New Orphaned Radioactive Sources Program in the United States International Conference on the Safety of Radiation Sources and the Security of Radioactive

    E-print Network

    1 The New Orphaned Radioactive Sources Program in the United States International Conference on the Safety of Radiation Sources and the Security of Radioactive Materials. September 14-18, 1998 Neil Naraine Exposure of the public to uncontrolled radioactive sources has become an significant concern to the United

  4. Radioactive Semivolatiles in Nuclear Fuel Reprocessing

    SciTech Connect

    R. T. Jubin; D. M. Strachan; G. Ilas; B. B. Spencer; N. R. Soelberg

    2014-09-01

    In nuclear fuel reprocessing, various radioactive elements enter the gas phase from the unit operations found in the reprocessing facility. In previous reports, the pathways and required removal were discussed for four radionuclides known to be volatile, 14C, 3H, 129I, and 85Kr. Other, less volatile isotopes can also report to the off-gas streams in a reprocessing facility. These were reported to be isotopes of Cs, Cd, Ru, Sb, Tc, and Te. In this report, an effort is made to determine which, if any, of 24 semivolatile radionuclides could be released from a reprocessing plant and, if so, what would be the likely quantities released. As part of this study of semivolatile elements, the amount of each generated during fission is included as part of the assessment for the need to control their emission. Also included in this study is the assessment of the cooling time (time out of reactor) before the fuel is processed. This aspect is important for the short-lived isotopes shown in the list, especially for cooling times approaching 10 y. The approach taken in this study was to determine if semivolatile radionuclides need to be included in a list of gas-phase radionuclides that might need to be removed to meet Environmental Protection Agency (EPA) and Nuclear Regulatory Commission (NRC) regulations. A list of possible elements was developed through a literature search and through knowledge and literature on the chemical processes in typical aqueous processing of nuclear fuels. A long list of possible radionuclides present in irradiated fuel was generated and then trimmed by considering isotope half-life and calculating the dose from each to a maximum exposed individual with the US EPA airborne radiological dispersion and risk assessment code CAP88 (Rosnick 1992) to yield a short list of elements that actually need to be considered for control because they require high decontamination factors to meet a reasonable fraction of the regulated release. Each of these elements is then discussed with respect to what is known in the literature about their behavior in a reprocessing facility. The context for the evaluation in this document is a UO2-based fuel processed through an aqueous-based reprocessing system with a TBP-based solvent extraction chemistry. None of these elements form sufficiently volatile compounds in the context of the reprocessing facility to be of regulatory concern.

  5. Measurement of residual radioactivity in the nuclear facility being decommissioned

    SciTech Connect

    Ezure, H.; Yokota, M.; Komatsu, J.; Mizuno, O. [Research Association for Nuclear Facility Decommissioning (RANDEC), Ibaraki-Ken (Japan)] [and others

    1996-12-31

    Before site radioactive-free release of a nuclear facility being decommissioned, a termination survey should be carried out on radioactivity, because the site is possibly deposited mainly by {sup 60}Co, {sup 137}Cs, etc. This requires to be confirmed by a radioactivity measurement. However, the site is characterized by a very large area and by a very low level or little residual radioactivity. Therefore, detection and measuring works are required to be very efficient. Further the detection of {sup 60}Co is disturbed by the background due to {sup 40}K and other natural radioactivities. In order to enhance the efficiencies, a measuring system is being developed, which consists of several Nal(Tl) detectors and electronic circuits mounted on a vehicle and further, the position of measuring points is be determined by an auto-positioning apparatus. As a result of field running test, the vehicle can be located within a short distance from the measuring goal and it was confirmed that measuring operation is organized in sequence.

  6. Spreadsheet application to classify radioactive material for shipment

    SciTech Connect

    Brown, A.N.

    1997-12-01

    A spreadsheet application has been developed at the Idaho National Engineering and Environmental Laboratory to aid the shipper when classifying nuclide mixtures of normal form, radioactive materials. The results generated by this spreadsheet are used to confirm the proper US Department of Transportation (DOT) classification when offering radioactive material packages for transport. The user must input to the spreadsheet the mass of the material being classified, the physical form (liquid or not), and the activity of each regulated nuclide. The spreadsheet uses these inputs to calculate two general values: (1) the specific activity of the material, and (2) a summation calculation of the nuclide content. The specific activity is used to determine if the material exceeds the DOT minimal threshold for a radioactive material (Yes or No). If the material is calculated to be radioactive, the specific activity is also used to determine if the material meets the activity requirement for one of the three Low Specific Activity designations (LSA-I, LSA-II, LSA-III, or Not LSA). Again, if the material is calculated to be radioactive, the summation calculation is then used to determine which activity category the material will meet (Limited Quantity, Type A, Type B, or Highway Route Controlled Quantity).

  7. Scrap metal management issues associated with naturally occurring radioactive material

    SciTech Connect

    Smith, K.P.; Blunt, D.L.

    1995-08-01

    Certain industrial processes sometimes generate waste by-products that contain naturally occurring radioactive material (NORM) at elevated concentrations. Some industries, including the water treatment, geothermal energy, and petroleum industries, generate scrap metal that may be contaminated with NORM wastes. Of these three industries, the petroleum industry probably generates the largest quantity of NORM-contaminated equipment, conservatively estimated at 170,000 tons per year. Equipment may become contaminated when NORM-containing scale or sludge accumulates inside water-handling equipment. The primary radionuclides of concern in these NORM wastes are radium-226 and radium-228. NORM-contaminated equipment generated by the petroleum industry currently is managed several ways. Some equipment is routinely decontaminated for reuse; other equipment becomes scrap metal and may be disposed of by burial at a licensed landfill, encapsulation inside the wellbore of an abandoned well, or shipment overseas for smelting. In view of the increased regulatory activities addressing NORM, the economic burden of managing NORM-contaminated wastes, including radioactive scrap metal, is likely to continue to grow. Efforts to develop a cost-effective strategy for managing radioactive scrap metal should focus on identifying the least expensive disposition options that provide adequate protection of human health and the environment. Specifically, efforts should focus on better characterizing the quantity of radioactive scrap available for recycle or reuse, the radioactivity concentration levels, and the potential risks associated with different disposal options.

  8. Miscellaneous radioactive materials detected during uranium mill tailings surveys

    SciTech Connect

    Wilson, M.J.

    1993-10-01

    The Department of Energy`s (DOE) Office of Environmental Restoration and Waste Management directed the Oak Ridge National Laboratory Pollutant Assessments Group in the conduct of radiological surveys on properties in Monticello, Utah, associated with the Mendaciously millsite National Priority List site. During these surveys, various radioactive materials were detected that were unrelated to the Monticello millsite. The existence and descriptions of these materials were recorded in survey reports and are condensed in this report. The radioactive materials detected are either naturally occurring radioactive material, such as rock and mineral collections, uranium ore, and radioactive coal or manmade radioactive material consisting of tailings from other millsites, mining equipment, radium dials, mill building scraps, building materials, such as brick and cinderblock, and other miscellaneous sources. Awareness of the miscellaneous and naturally occurring material is essential to allow DOE to forecast the additional costs and schedule changes associated with remediation activities. Also, material that may pose a health hazard to the public should be revealed to other regulatory agencies for consideration.

  9. THE MORTALITY OF BACTERIOPHAGE CONTAINING ASSIMILATED RADIOACTIVE PHOSPHORUS

    PubMed Central

    Hershey, A. D.; Kamen, M. D.; Kennedy, J. W.; Gest, H.

    1951-01-01

    The bacteriophage T4 containing assimilated radioactive phosphorus is inactivated at a rate proportional to the specific radioactivity of the constituent phosphorus. The beta radiation from the phosphorus makes a negligible contribution to this effect. The inactivation is therefore a direct consequence of the nuclear reaction, which kills the phage with an efficiency of about 1/12. Several phages related to T4 behave similarly. When radioactive phage is grown from a seed of non-radioactive phage, all of the phage progeny are subject to killing by radioactive decay. The phage is killed by beta radiation from P32 with an efficiency of about 1/100 per ionization within the particle volume. Bacteriophage T4 and its relatives contain about 500,000 atoms of phosphorus per infective particle. Virtually all this phosphorus is adsorbed to bacteria with the specificity characteristic of the infective particles, and none of it can be removed from the particles by the enzyme desoxyribonuclease. The phosphorus content per particle, together with the published data on analytical composition, indicates a particle diameter close to 110 mµ for the varieties of phage studied. PMID:14824499

  10. Protocols for implementing DOE authorized release of radioactive scrap metals.

    PubMed

    Chen, S Y; Arnish, J; Kamboj, S; Nieves, L A

    1999-11-01

    A process to implement the U.S. Department of Energy's (DOE) policy for authorized release of radioactive materials from DOE facilities is provided in the Draft Handbook for Controlling Release for Reuse or Recycle of Property Containing Residual Radioactive Material, published by DOE in 1997 and distributed to DOE field offices for interim use and implementation. The authorized release of such property is intended to permit its beneficial use across the entire DOE complex. A computerized management tool--P2Pro(RSM)--has been developed to aid in carrying out the release process for radioactive metals. It contains protocols for the authorized release process and relevant information to facilitate the evaluation of scrap metals for reuse and recycle. The P2Pro(RSM) protocols provide DOE and its contractors with an effective, user-friendly tool for managing authorized release activities P2Pro(RSM) is designed to be used in the Windows environment. The protocols incorporate a relational database coupled with a graphic-user interface to guide the user through the appropriate steps so authorized release limits can be developed. With the information provided in the database, an as-low-as-reasonably-achievable (ALARA) optimization process can be easily set up and run for up to 10 alternatives for disposition of radioactive scrap metals. The results of the ALARA optimization process can be printed in a series of reports and submitted as part of the application for the authorized release of the radioactive scrap metals. PMID:10527156

  11. Economics and risks of recycling radioactively contaminated concrete

    SciTech Connect

    Parker, F.L.; Ayers, K.W. [Vanderbilt Univ., Nashville, TN (United States)

    1997-12-31

    As Decontamination and Decommissioning activities proceed within the DOE complex, tremendous volumes of both radioactively contaminated and non-contaminated concrete will be processed for disposal. Current practice is to decontaminate the concrete, dispose of the contamination at LLW facilities and ship the concrete rubble to C & D landfills for disposal. This study evaluates the economic, health and safety, legal, and social aspects of recycling radioactively contaminated concrete. Probabilistic models were used to estimate costs and risks. The model indicates that the radioactively contaminated concrete can be recycled at the same or lower cost than current or alternative practices. The risks associated with recycling were consistently less than or equal to the other alternatives considered.

  12. Nuclear astrophysics at the Holifield Radioactive Ion Beam Facility

    SciTech Connect

    Smith, M.S.

    1994-12-31

    The potential for understanding spectacular stellar explosions such as novae, supernovae, and X-ray bursts will be greatly enhanced by the availability of the low-energy, high-intensity, accelerated beams of proton-rich radioactive nuclei currently being developed at the Holifield Radioactive Ion Beam Facility (HRIBF) at Oak Ridge National Laboratory. These beams will be utilized in absolute cross section measurements of crucial (p, {gamma}) capture reactions in efforts to resolve the substantial qualitative uncertainties in current models of explosive stellar hydrogen burning outbursts. Details of the nuclear astrophysics research program with the unique HRIBF radioactive beams and a dedicated experimental endstation--centered on the Daresbury Recoil Separator--will be presented.

  13. Wide-range radioactive-gas-concentration detector

    DOEpatents

    Anderson, D.F.

    1981-11-16

    A wide-range radioactive-gas-concentration detector and monitor capable of measuring radioactive-gas concentrations over a range of eight orders of magnitude is described. The device is designed to have an ionization chamber 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.

  14. Commission operation. National Low-Level Radioactive Waste Management Program

    NASA Astrophysics Data System (ADS)

    1984-09-01

    Since Congress enacted the Low-Level Radioactive Waste Policy Act, the states have prepared to meet their responsibilities for management of low-level radioactive waste by entering into regional compacts. This option document is intended to provide a framework for the operation of a compact commission formed as the governing body of a low-level radioactive waste compact. The document is designed to be easily modified to meet the needs of various regional compacts. The ideas and format presented were taken in general from the Federal Administrative procedures Act, various state administrative procedures, and the state regulatory agencies' rules of procedure. Requirements of filing, time frames, and standard language are written from a legal perspective.

  15. Development of a wireless radioactive material sensor network

    NASA Astrophysics Data System (ADS)

    Katsis, Dimosthenis; Burns, David; Henriquez, Stanley; Howell, Steve; Litz, Marc

    2011-10-01

    Our team at the United States Army Research Laboratory (ARL) has designed and developed a low-power, compact, wireless-networked gamma sensor (WGS) array. The WGS system provides high sensitivity gamma photon detection and remote warning for a broad range of radioactive materials. This sensor identifies the presence of a 1 ?Ci Cs137 source at a distance of 1.5 m. The networked array of sensors presently operates as a facility and laboratory sensor for the movement of radioactive check sources. Our goal has been to apply this architecture for field security applications by incorporating low-power design with compact packaging. The performance of this radiation measurement network is demonstrated for both detection and location of radioactive material.

  16. Cluster radioactivities from an island of cluster emitters

    SciTech Connect

    Shanmugam, G.; Carmel Vigila Bai, G.M. [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli 627 002 (India)] [Department of Physics, Manonmaniam Sundaranar University, Tirunelveli 627 002 (India); Kamalaharan, B. [Department of Physics, Presidency College, Madras 600 005 (India)] [Department of Physics, Presidency College, Madras 600 005 (India)

    1995-05-01

    We have recently developed a realistic model for studying cluster radioactivities from actinide nuclei. This model uses a cubic potential in the overlapping region connected by a Yukawa-plus-exponential potential in the post-scission region. In the present work we use this model to study {sup 4}He, {sup 12}C, {sup 16}O, and {sup 28}Si radioactivities in the region of nuclides with proton and neutron number in the range {ital Z}=56--64 and {ital N}=58--72, which has been recently identified by Poenaru {ital et} {ital al}. as a new island of such cluster emitters. It is found that charge equilibration is not needed in the study of these radioactivities and the half-lives obtained for these decays lie very close to those reported by Poenaru {ital et} {ital al}. using their analytical super asymmetric fission model.

  17. Radioactive waste and contamination in the former Soviet Union

    SciTech Connect

    Suokko, K.; Reicher, D. (Natural Resources Defense Council, Washington, DC (United States))

    1993-04-01

    Decades of disregard for the hazards of radioactive waste have created contamination problems throughout the former Soviet Union rivaled only by the Chernobyl disaster. Although many civilian activities have contributed to radioactive waste problems, the nuclear weapons program has been by far the greatest culprit. For decades, three major weapons production facilities located east of the Ural Mountains operated in complete secrecy and outside of environmental controls. Referred to until recently only by their postal abbreviations, the cities of Chelyabinsk-65, Tomsk-7, and Krasnoyarsk-26 were open only to people who worked in them. The mismanagement of waste at these sites has led to catastrophic accidents and serious releases of radioactive materials. Lack of public disclosure, meanwhile, has often prevented proper medical treatment and caused delays in cleanup and containment. 5 refs.

  18. Application of microwave solidification technology to radioactive waste

    SciTech Connect

    Harris, M.; Sprenger, G.; Roushey, B.; Fenner, G.; Nieweg, R.

    1995-09-28

    The EPA has declared vitrification to be the Best Available Demonstrated Technology (BDAT) for High Level Radioactive Waste (40 CFR 268.42). Vitrification has been chosen as the method of choice for treating a number of radioactive residues and wastes in the DOE complex. Vitrification offers advantages of waste volume reduction, the ability to handle changing waste forms, and a stable, nonleachable final waste form. Microwave heating is a superior method for vitrification of radioactive wastes. Advantages of microwave heating include: (1) direct waste heating, eliminates need for electrodes, refractories and other consumables; (2) ``in-can`` processing allows for treatment of the material in its final container, (3) a mechanically simple system where the microwaves are generated away from the treatment area and transmitted to the treatment applicator by a wave guide, thus minimizing worker exposure to radiation; (4) easier equipment maintenance; and (5) a high degree of public acceptance.

  19. (1) Selective separation and solidification of radioactive nuclides by zeolites

    NASA Astrophysics Data System (ADS)

    Mimura, Hitoshi; Sato, Nobuaki; Kirishima, Akira

    Massive tsunami generated by the Great East Japan Earthquake attacked the Fukushima Daiichi Nuclear Power Plant and caused the nuclear accident of level 7 to overturn the safety myth of the nuclear power generation. The domestic worst accident does not yet reach the convergence, and many inhabitants around the power plant are forced to double pains of earthquake disaster and nuclear accident. Large amounts of high-activity-level water over 200,000 tons are accumulated on the basement floor of each turbine building, which is a serious obstacle to take measures for the nuclear accident. For the decontamination of high-activity-level water containing seawater, the inorganic ion-exchangers having high selectivity are effective especially for the selective removal of radioactive Cs. On the other hand, radioactive Cs and I released into the atmosphere from the power plant spread widely around Fukushima prefecture, and the decontamination of rainwater and soil become the urgent problem. At present, passing about four months after nuclear accident, the radioactive nuclides of 137Cs and 134Cs are mainly contained in the high-activity-level water and the selective adsorbents for radioactive Cs play an important part in the decontamination. Since the construction of original decontamination system is an urgent necessity, selective separation methods using inorganic ion-exchangers are greatly expected. From the viewpoint of cost efficiency and high Cs-selectivity, natural zeolites are effective for the decontamination of radioactive Cs. This special issue deals with the selective separation and solidification of radioactive Cs and Sr using zeolites.

  20. Emissions of naturally occuring radioactivity: Stauffer elemental phosphorus plant

    SciTech Connect

    Andrews, V.E.

    1982-11-01

    Naturally occurring radioactivity was measured in the atmospheric emissions and process materials of a thermal phosphate (elemental phosphorus) plant. Representative exhaust stack samples were collected from each process in the plant. The phosphate ore contained about 120 parts per million uranium. The radioactivity emitted in greatest quantity was radon-222 with an annual release from the plant of 8.3 curies. Emissions of lead-210 and polonium-210 were measured at 280 and 200 millicuries per year. Annual emissions of each of the other radionuclides of the uranium decay chain were estimated to be 4.2 millicuries. The slag pile was determined not to be a source of radon.

  1. The Scientific program with RIBRAS (Radioactive Ion Beams in Brasil)

    SciTech Connect

    Lichtenthaeler, R.; Lepine-Szily, A.; Guimaraes, V.; Faria, P. N. de; Mendes, D. R. Jr.; Pires, K. C. C.; Morcelle, V.; Hussein, M. S.; Barioni, A.; Condori, R. Pampa; Morais, M. C.; Alcantara Nunez, J.; Camargo, O. Jr.; Otani, Y.; Leistenschneider, E.; Scarduelli, V. [Instituto de Fisica da Universidade de Sao Paulo, C.P. 66318, 05389-970 Sao Paulo (Brazil); Benjamim, E. A. [Universidad de Santiago de Compostela, Depto. Fisica Particulas, Facultad Fisica, Campus Sur s/n 15786 Santiago de Compostela (Spain) (Spain); Moro, A. M. [Departamento de FAMN, Universidad de Sevilla, Apdo 1065, E-41080, Sevilla (Spain); Arazi, A. [Laboratorio Tandar, Departamento de Fisica, Comision Nacional de Energia Atomica, Av. del Libertador 8250, (1429), Buenos Aires (Argentina); Assuncao, M. [UNIFESP-Campus de Diadema, SP (Brazil)] (and others)

    2009-06-03

    The Radioactive Ion Beams Facility (RIBRAS) is in operation since 2004 at the Pelletron Accelerator Laboratory of the University of Sao Paulo and consists of two superconducting solenoids capable of producing low energy secondary beams of light exotic nuclei. Measurements of the elastic scattering, breakup and transfer reactions with radioactive projectiles such as {sup 6}He,{sup 8}Li,{sup 7}Be on several targets have been performed. A review of the research program carried on along the last four years using the RIBRAS facility is presented.

  2. New calculation of radioactive secondaries in cosmic rays

    E-print Network

    I. V. Moskalenko; S. G. Mashnik; A. W. Strong

    2001-08-17

    We use a new version of our numerical model for particle propagation in the Galaxy to study radioactive secondaries. For evaluation of the production cross sections we use the Los Alamos compilation of all available experimental cross sections together with calculations using the improved Cascade-Exciton Model code CEM2k. Using the radioactive secondary ratios 26Al/27Al, 36Cl/Cl, 54Mn/Mn, we show how the improved cross-section calculations together with the new propagation code allow us to better constrain the size of the CR halo.

  3. Monitoring radioactive xenon gas in room air using activated charcoal

    SciTech Connect

    Langford, J.; Thompson, G. (Princess Margaret Hospital for Children, Perth (Australia) Sir Charles Gairdner Hospital, Perth (Australia))

    1990-03-01

    A method for monitoring room air for radioactive xenon gas is described. It uses activated charcoal vials, a vacuum source and a well-type scintillation counter. The method may be adapted for detection and identification of any radioactive gas excluding those with ultra-short half-lives. Sampling room air during xenon-133 ({sup 133}Xe) ventilation lung studies was performed using this technique. The results show that low concentrations of {sup 133}Xe in room air can be reliably detected and that staff exposure to {sup 133}Xe at this institution was within ICRP recommendations.

  4. Rheology of Savannah River site tank 42 HLW radioactive sludge

    SciTech Connect

    Ha, B.C.

    1997-11-05

    Knowledge of the rheology of the radioactive sludge slurries at the Savannah River Site is necessary in order to ensure that they can be retrieved from waste tanks and processed for final disposal. At Savannah River Site, Tank 42 sludge represents on of the first HLW radioactive sludges to be vitrified in the Defense Waste Processing Facility. The rheological properties of unwashed Tank 42 sludge slurries at various solids concentrations were measured remotely in the Shielded Cells at the Savannah River Technology Center using a modified Haake Rotovisco viscometer.

  5. Emergency department management of patients internally contaminated with radioactive material.

    PubMed

    Kazzi, Ziad; Buzzell, Jennifer; Bertelli, Luiz; Christensen, Doran

    2015-02-01

    After a radiation emergency that involves the dispersal of radioactive material, patients can become externally and internally contaminated with 1 or more radionuclides. Internal contamination can lead to the delivery of harmful ionizing radiation doses to various organs and tissues or the whole body. The clinical consequences can range from acute radiation syndrome to the long-term development of cancer. Estimating the amount of radioactive material absorbed into the body can guide the management of patients. Treatment includes, in addition to supportive care and long term monitoring, certain medical countermeasures like Prussian blue, calcium diethylenetriamine pentaacetic acid (DTPA) and zinc DTPA. PMID:25455668

  6. Journey to the Nevada Test Site Radioactive Waste Management Complex

    ScienceCinema

    None

    2014-10-28

    Journey to the Nevada Test Site Radioactive Waste Management Complex begins with a global to regional perspective regarding the location of low-level and mixed low-level waste disposal at the Nevada Test Site. For decades, the Nevada National Security Site (NNSS) has served as a vital disposal resource in the nation-wide cleanup of former nuclear research and testing facilities. State-of-the-art waste management sites at the NNSS offer a safe, permanent disposal option for U.S. Department of Energy/U.S. Department of Defense facilities generating cleanup-related radioactive waste.

  7. Radioactive beams from gas catchers: The CARIBU facility

    NASA Astrophysics Data System (ADS)

    Savard, G.; Baker, S.; Davids, C.; Levand, A. F.; Moore, E. F.; Pardo, R. C.; Vondrasek, R.; Zabransky, B. J.; Zinkann, G.

    2008-10-01

    Gas catchers allow the transformation of radioactive recoils from various sources into a good optical quality low-energy radioactive beam that is then available for experiments at low-energy or for further acceleration. The CARIBU project uses such a large gas catcher to create beams of neutron-rich isotopes from a Californium source for post-acceleration through the ATLAS superconducting linac to open new research opportunities for nuclear structure physics and astrophysics. The RF gas catcher developed at Argonne has now demonstrated operation at the high intensity required for this application.

  8. Journey to the Nevada Test Site Radioactive Waste Management Complex

    SciTech Connect

    None

    2007-08-01

    Journey to the Nevada Test Site Radioactive Waste Management Complex begins with a global to regional perspective regarding the location of low-level and mixed low-level waste disposal at the Nevada Test Site. For decades, the Nevada National Security Site (NNSS) has served as a vital disposal resource in the nation-wide cleanup of former nuclear research and testing facilities. State-of-the-art waste management sites at the NNSS offer a safe, permanent disposal option for U.S. Department of Energy/U.S. Department of Defense facilities generating cleanup-related radioactive waste.

  9. HPGe virtual point detector for radioactive disk sources.

    PubMed

    Alfassi, Z B; Lavi, N; Presler, O; Pushkarski, V

    2007-02-01

    Validity of the model of a virtual point detector (implying existence of a point where all interactions virtually occur) was confirmed for measurements of radioactive disk sources with HPGe detectors. The existing correlation of the count rates with the distance between the virtual plain detector and the detector face makes it possible to inter- and extrapolate calibration curves for disk radioactive sources for use at different source-detector face distances. The dependence of the distance between the virtual plane detector and the detector face on the photon energy was studied for sources of various radii. PMID:17000113

  10. Criteria impacting shipments of Rocky Flats Plant radioactive mixed wastes

    SciTech Connect

    Clawson, R.L.; Eide, J.H.

    1992-05-01

    Westinghouse Hanford Company, Transportation and Packaging Division, under contract for the Los Alamos Technology Office-Rocky Flats Plant, has developed this synopsis report to be used as a reference in the development of the Rocky Flats Plant Comprehensive Treatment and Management Plan and the Rocky Flats Plant Residue Elimination Plan. This report represents the criteria for packaging, shipping, and transporting Rocky Flats Plant radioactive mixed wastes. It is a compilation of state and federal regulations, US Department of Energy orders, and acceptance criteria specific to US Department of Energy radioactive mixed waste treatment, storage and disposal facilities.

  11. Three multimedia models used at hazardous and radioactive waste sites

    SciTech Connect

    NONE

    1996-01-01

    The report provides an approach for evaluating and critically reviewing the capabilities of multimedia models. The study focused on three specific models: MEPAS version 3.0, MMSOILS Version 2.2, and PRESTO-EPA-CPG Version 2.0. The approach to model review advocated in the study is directed to technical staff responsible for identifying, selecting and applying multimedia models for use at sites containing radioactive and hazardous materials. In the report, restrictions associated with the selection and application of multimedia models for sites contaminated with radioactive and mixed wastes are highlighted.

  12. Assessing CZT detector performance for environmental radioactivity investigations.

    PubMed

    Rahman, Rubina; Plater, A J; Nolan, P J; Appleby, P G

    2013-05-01

    Cadmium zinc telluride (CdZnTe or CZT) is the leading semiconductor detector for gamma spectroscopy at room temperature. In the present study, a coplanar-grid CZT detector was used for gamma-ray measurements of environmental radioactivity on a contaminated saltmarsh sediment core in comparison with results from a coaxial high-purity germanium detector to assess their comparative performance. The findings reveal that the CZT performs well for both (241)Am and (137)Cs measurements over a broad range of activities, despite limited detector efficiency, and can be used to good effect in the study of environmental radioactivity in contaminated estuarine settings. PMID:23060429

  13. Vitrification of intermediate level radioactive waste by induction heating

    SciTech Connect

    Sobolev, I.A.; Dmitriyev, S.A.; Lifanov, F.A.; Stefanovsky, S.V.; Kobelev, A.P.; Kornev, V.I.; Knyazev, O.A.; Tsveshko, O.N. [SIA Radon, Moscow (Russian Federation)

    1995-12-31

    Vitrification of intermediate level liquid and solid radioactive wastes is an effective method of their immobilization. A new type of melter -- cold crucible -- suitable for production of high fusible materials has been developed. No refractories and internal electrodes are used in this melter. Based on the preliminary experience of SIA Radon with lab-scale and pilot plants, the full-scale plants for vitrification of liquid and solid radioactive wastes have been constructed. The main process variables such as melt capacity, melting ratio, cesium volatilization as well as materials properties have been determined. Advantages of cold crucible over Joule heated ceramic melter have been shown. Process flow sheets have been described.

  14. Industrial-Scale Processes For Stabilizing Radioactively Contaminated Mercury Wastes

    SciTech Connect

    Broderick, T. E.; Grondin, R.

    2003-02-24

    This paper describes two industrial-scaled processes now being used to treat two problematic mercury waste categories: elemental mercury contaminated with radionuclides and radioactive solid wastes containing greater than 260-ppm mercury. The stabilization processes were developed by ADA Technologies, Inc., an environmental control and process development company in Littleton, Colorado. Perma-Fix Environmental Services has licensed the liquid elemental mercury stabilization process to treat radioactive mercury from Los Alamos National Laboratory and other DOE sites. ADA and Perma-Fix also cooperated to apply the >260-ppm mercury treatment technology to a storm sewer sediment waste collected from the Y-12 complex in Oak Ridge, TN.

  15. Two-proton radioactivity - a curiosity of Nature?

    SciTech Connect

    Blank, B. [CEN Bordeaux-Gradignan, Le Haut-Vigneau, F-33175 Gradignan Cedex (France)

    2004-04-12

    In recent experiments at GANIL and GSI, we studied the decay of 45Fe, according to theoretical predictions one of the most promising cases for 2p radioactivity. Our results show for the first time clear evidence of this new radioactivity. In another experiment at GANIL, 2p emission was observed from excited states in 17Ne. In these complete kinematics measurements performed at the SPEG facility of GANIL, the angle between the two protons has been measured evidencing a 2He emission pattern. Both results will be presented and future studies are discussed.

  16. Radioactive air emissions notice of construction for HEPA filtered vacuum radioactive air emission units

    SciTech Connect

    Johnson, R.E.

    1997-10-27

    This notice of construction (NOC) requests a categorical approval for construction and operation of certain portable high-efficiency particulate air (HEPA) filtered vacuum radionuclide airborne emission units (HVUs). Approval of this NOC application is intended to allow operation of the HVUs without prior project-specific approval. This NOC does not request replacement or supersedence of any previous agreements/approvals by the Washington State Department of Health (WDOH) for the use of vacuums on the Hanford Site. These previous agreements/approvals include the approved NOCs for the use of EuroClean HEPA vacuums at the T Plant Complex and the Kelly Decontamination System at the Plutonium-Uranium Extraction (PUREX) Plant. Also, this NOC does not replace or supersede the agreement reached regarding the use of HEPA hand-held/shop-vacuum cleaners for routine cleanup activities conducted by the Environmental Restoration Project. Routine cleanup activities are conducted during the surveillance and maintenance of inactive waste sites (Radioactive Area Remedial Action Project) and inactive facilities. HEPA hand-held/shop-vacuum cleaners are used to clean up spot surface contamination areas found during outdoor radiological field surveys, and to clean up localized radiologically contaminated material (e.g., dust, dirt, bird droppings, animal feces, liquids, insects, spider webs, etc.). This agreement, documented in the October 12, 1994 Routine Meeting Minutes, is based on routine cleanup consisting of spot cleanup of low-level contamination provided that, in each case, the source term potential would be below 0.1 millirem per year. This application is intended to request sitewide approval for the new activities, and provide an option for any facility on the site to use this approval, within the terms of this NOC. The HVUs used in accordance with this NOC will support reduction of radiological contamination at various locations on the Hanford Site. Radiation Protection Air Emissions, Washington Administrative Code (WAC) 246-247, require that the WDOH approve an NOC application before construction or modification of any emission unit that would release airborne radioactivity. This includes changes in the isotopic makeup of the source term or replacement of emission control equipment, which might contribute to an increase in the offsite dose from a licensed facility. Reduction of radiologically contaminated areas by HEPA vacuums is a current need. The U.S. Department of Energy, Richland Operations Office (DOE-RL) potentially could generate numerous monthly applications.

  17. 75 FR 36445 - Draft Regulatory Guide, DG-4018, “Constraint on Releases of Airborne Radioactive Materials To the...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2010-06-25

    ...Airborne Radioactive Materials To the Environment for Licensees Other Than Power Reactors...Airborne Radioactive Materials to the Environment for Licensees Other than Power Reactors...Airborne Radioactive Materials to the Environment for Licensees Other than Power...

  18. 10 CFR 835.209 - Concentrations of radioactive material in air.

    Code of Federal Regulations, 2010 CFR

    2010-01-01

    ...2010-01-01 2010-01-01 false Concentrations of radioactive material in air...External Exposure § 835.209 Concentrations of radioactive material in air. (a) The derived air concentration (DAC) values given in...

  19. 10 CFR 835.209 - Concentrations of radioactive material in air.

    Code of Federal Regulations, 2011 CFR

    2011-01-01

    ...2011-01-01 2011-01-01 false Concentrations of radioactive material in air...External Exposure § 835.209 Concentrations of radioactive material in air. (a) The derived air concentration (DAC) values given in...

  20. Low-Dose Radioactive Iodine Destroys Thyroid Tissue Left After Surgery

    MedlinePLUS

    Low-Dose Radioactive Iodine Destroys Thyroid Tissue Left after Surgery Adapted from the NCI Cancer Bulletin . A low dose of radioactive iodine given after surgery for thyroid cancer destroyed (ablated) ...

  1. The Use of Induction Melting for the Treatment of Metal Radioactive Waste - 13088

    SciTech Connect

    Zherebtsov, Alexander; Pastushkov, Vladimir; Poluektov, Pavel; Smelova, Tatiana; Shadrin, Andrey [JSC 'VNIINM', Rogova st., 5, 123098, Moscow (Russian Federation)] [JSC 'VNIINM', Rogova st., 5, 123098, Moscow (Russian Federation)

    2013-07-01

    The aim of the work is to assess the efficacy of induction melting metal for recycling radioactive waste in order to reduce the volume of solid radioactive waste to be disposed of, and utilization of the metal. (authors)

  2. 70 FR 68350 - Disposal of Radioactive Material by Release Into Sanitary Sewer Systems; Withdrawal of Advance...

    Federal Register 2010, 2011, 2012, 2013, 2014

    2005-11-10

    ...effect of new technologies on radionuclide solubilities, but also how the solubility of radioactive materials change in sanitary...guidance on how licensees should demonstrate the solubility of radioactive material released to...

  3. 77 FR 14445 - Leakage Tests on Packages for Shipment of Radioactive Material

    Federal Register 2010, 2011, 2012, 2013, 2014

    2012-03-09

    ...NRC-2011-0045] Leakage Tests on Packages for Shipment of Radioactive...4, ``Leakage Tests on Packages for Radioactive Material...Documents Access and Management System (ADAMS): Publicly available...containment criteria for Type B packages described in 10 CFR...

  4. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2014 CFR

    2014-07-01

    ...204-SAFETY AND HEALTH STANDARDS FOR FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive...material. (a) No employer shall possess, use or transport radioactive material in such a manner as to...

  5. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ...204-SAFETY AND HEALTH STANDARDS FOR FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive...material. (a) No employer shall possess, use or transport radioactive material in such a manner as to...

  6. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ...204-SAFETY AND HEALTH STANDARDS FOR FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive...material. (a) No employer shall possess, use or transport radioactive material in such a manner as to...

  7. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2012 CFR

    2012-07-01

    ...204-SAFETY AND HEALTH STANDARDS FOR FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive...material. (a) No employer shall possess, use or transport radioactive material in such a manner as to...

  8. 41 CFR 50-204.22 - Exposure to airborne radioactive material.

    Code of Federal Regulations, 2013 CFR

    2013-07-01

    ...204-SAFETY AND HEALTH STANDARDS FOR FEDERAL SUPPLY CONTRACTS Radiation Standards § 50-204.22 Exposure to airborne radioactive...material. (a) No employer shall possess, use or transport radioactive material in such a manner as to...

  9. In situ electrochemical characterization of grouted radioactive waste

    SciTech Connect

    Gu, Jingyan; Shen, Wu-Mian; Tomkiewicz, Micha [Brooklyn Coll., NY (United States). Dept. of Physics; Kruger, A.A. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-04-01

    At the Hanford Site, twenty-eight double-shell tanks (DST) and one hundred and forty nine single-shell tanks (SST) are used for storage of radioactive liquid and sludge wastes and sat cake. A fundamental goal of the Westinghouse Hanford Company is to end the current storage practice for liquid wastes and to permanently dispose of the waste. The Hanford Defense Waste Environmental Impact Statement and subsequent record of decision has identified a cement-based waste form for disposal of DST low-level liquid waste. The low level radioactive fractions of these wastes will be immobilized in a cementitious grout at the Hanford Grout Processing Facility and disposed of in concrete vaults of the Grout Disposal Facility. Prior to closing each vault, postcuring verification will show that the final product meets the performance requirements. Any long term disposal system of radioactive waste will require monitoring to warn against structural deterioration and/or leach of the radioactive or hazardous components into the environment. We are investigating the possibility of monitoring the degree of immobilization of the waste by embedding a grid of long-lasting electrodes in grout. This work describes our ongoing attempts to understand the physics and chemistry of charge carriers in the grout under various load conditions.

  10. Mitigation of plant penetration into radioactive waste utilizing herbicides

    SciTech Connect

    Cox, G.R.

    1982-01-01

    This paper describes the use of herbicides as an effective method of precluding plant root penetration into buried radioactive wastes. The discussed surface applications are selective herbicides to control broadleaf vegetation in grasses; nonselective herbicides, which control all vegetation; and slow-release forms of these herbicides to prolong effectiveness.

  11. OBSERVATION OF BRICKWORK OF PHOSPHORUS OVENS USING RADIOACTIVE PREPARATIONS

    Microsoft Academic Search

    Schmeiser

    1960-01-01

    The supervision of furnace-wall thicknesses during operation by means of ; radioactive isotopes has definite advantages. A close examination of furnace ; walls and floor is ordinarily possible only when the furnace is completely empty. ; But since this requires several weeks, during which the furnace cannot be used, ; it is practicable only when extensive repairs are necessary. However,

  12. Accelerated radioactive nuclear beams: Existing and planned facilities

    SciTech Connect

    Nitschke, J.M.

    1992-07-01

    An over-view of existing and planned radioactive nuclear beam facilities world-wide. Two types of production methods are distinguished: projectile fragmentation and the on-line isotope separator (ISOL) method. While most of the projectile fragmentation facilities are already in operation, almost all the ISOL-based facilities are in still the planning stage.

  13. DEVELOPMENT OF GLASS MATRICES FOR HLW RADIOACTIVE WASTES

    Microsoft Academic Search

    Jantzen

    2010-01-01

    Vitrification is currently the most widely used technology for the treatment of high level radioactive wastes (HLW) throughout the world. Most of the nations that have generated HLW are immobilizing in either borosilicate glass or phosphate glass. One of the primary reasons that glass has become the most widely used immobilization media is the relative simplicity of the vitrification process,

  14. Lessons learned from two very different large radioactive spills

    Microsoft Academic Search

    Waggoner

    1996-01-01

    Hard lessons in radioactive spill response, including decontamination and confinement methods, priority setting, survey techniques, and release limit determination were learned (by trial and error) from two spills which occurred recently at the Radiochemical Engineering and Development Center (REDC) at Oak Ridge National Laboratory. The responsibilities of radiological control personnel, decontamination workers, and facility management were often redefined as decontamination

  15. The Accumulation of Radioactive Contaminants in Drinking Water Distribution Systems

    EPA Science Inventory

    The accumulation of trace contaminants in drinking water distribution systems has been documented and the subsequent release of the contaminants back to the water is a potential exposure pathway. Radioactive contaminants are of particular concern because of their known health eff...

  16. Characterization and Dissolution Kinetics Testing of Radioactive H-3 Calcine

    SciTech Connect

    Garn, Troy Gerry; Batcheller, Thomas Aquinas

    2002-09-01

    Characterization and dissolution kinetics testing were performed with Idaho radioactive H-3 calcine. Calcine dissolution is the key front-end unit operation for the Separations Alternative identified in the Idaho High Level Waste Draft EIS. The impact of the extent of dissolution on the feasibility of Separations must be clearly quantified.

  17. SURFACE COVERINGS OF STRUCTURAL COMPONENTS IN RADIOACTIVE LOCATIONS

    Microsoft Academic Search

    Komarovskii

    1961-01-01

    A surface coating should be stable to radiation, corrosive liquids and ; gases and thermal effects, should be easily decontaminated, should possess ; mechanical strength and resistance to wear, and should show a minimum amount of ; induced radioactivity due to neutron interaction. Although stainless steel sheet ; 2 to 3 mm thick has been extensively used to cover the

  18. Best Practices for the Security of Radioactive Materials

    Microsoft Academic Search

    D. T. Coulter; S. Musolino

    2009-01-01

    This work is funded under a grant provided by the US Department of Health and Human Services, Centers for Disease Control. The Department of Health and Mental Hygiene (DOHMH) awarded a contract to Brookhaven National Laboratory (BNL) to develop best practices guidance for Office of Radiological Health (ORH) licensees to increase on-site security to deter and prevent theft of radioactive

  19. Experiences managing radioactive material at the National Ignition Facility.

    PubMed

    Thacker, Rick L

    2013-06-01

    The National Ignition Facility at Lawrence Livermore National Laboratory is the world's largest and most energetic laser system for inertial confinement fusion and experiments studying high energy density science. Many experiments performed at the National Ignition Facility involve radioactive materials; these may take the form of tritium and small quantities of depleted uranium used in targets, activation products created by neutron-producing fusion experiments, and fission products produced by the fast fissioning of the depleted uranium. While planning for the introduction of radioactive material, it was recognized that some of the standard institutional processes would need to be customized to accommodate aspects of NIF operations, such as surface contamination limits, radiological postings, airborne tritium monitoring protocols, and personnel protective equipment. These customizations were overlaid onto existing work practices to accommodate the new hazard of radioactive materials. This paper will discuss preparations that were made prior to the introduction of radioactive material, the types of radiological work activities performed, and the hazards and controls encountered. Updates to processes based on actual monitoring results are also discussed. PMID:23629067

  20. Overview of linac applications at future radioactive beam facilities

    SciTech Connect

    Nolen, J.A.

    1996-11-01

    There is considerable interest worldwide in the research which could be done at a next generation, advanced radioactive beam facility. To generate high quality, intense beams of accelerated radionuclides via the {open_quotes}isotope separator on-line{close_quotes} (ISOL) method requires two major accelerator components: a high power (100 kW) driver device to produce radionuclides in a production target/ion source complex, and a secondary beam accelerator to produce beams of radioactive ions up to energies on the order of 10 MeV per nucleon over a broad mass range. In reviewing the technological challenges of such a facility, several types of modem linear accelerators appear well suited. This paper reviews the properties of the linacs currently under construction and those proposed for future facilities for use either as the driver device or the radioactive beam post-accelerator. Other choices of accelerators, such as cyclotrons, for either the driver or secondary beam devices of a radioactive beam complex will also be compared. Issues to be addressed for the production accelerator include the choice of ion beam types to be used for cost-effective production of radionuclides. For the post-accelerator the choice of ion source technology is critical and dictates the charge-to-mass requirements at the injection stage.

  1. Natural diatomite process for removal of radioactivity from liquid waste

    Microsoft Academic Search

    Ahmet Erdal Osmanlioglu

    2007-01-01

    Diatomite has a number of unique physical properties and has found diversified industrial utilization. The filtration characteristics are particularly significant in the purification of liquids. The purpose of this study was to test natural diatomaceous earth (diatomite) as an alternative material that could be used for removal of radioactivity from liquid waste. A pilot-scale column-type device was designed. Natural diatomite

  2. Foaming and Antifoaming in Radioactive Waste Pretreatment and Immobilization

    Microsoft Academic Search

    Darsh T. Wasan

    2002-01-01

    Radioactive waste treatment processes usually involve concentration of radionuclides before waste can be immobilized by storing it in stable solid form. Foaming is observed at various stages of waste processing like sludge chemical processing and melter operations. Hence, the objective of this research was to study the mechanisms that produce foaming during nuclear waste treatment, to identify key parameters which

  3. Ion sources for radioactive beams and related problems (Review) (invited)

    Microsoft Academic Search

    R. Kirchner; GSI Darmstadt

    1996-01-01

    Ion sources for radioactive beam facilities are integrated systems of production target and ionizer which have to convert the limited number of particles produced in nuclear reactions efficiently and selectively into an ion beam. The figures of merit for such a system are thus its efficiency for a desired isotope and its discrimination against the unwanted elements. The efficiency is

  4. Don't Throw Away Your Radioactive Sources!

    ERIC Educational Resources Information Center

    Tracy, Charles; Cunningham, Elizabeth

    2014-01-01

    This article reports on a plea directed to schools in England that changed status to an "academy" and thus lost their Local Authority Radiation Protection Adviser (RPA) service. These schools have been encouraged to do all that they can to hang on to their sources (radioactive equipment used in classroom experiments to investigate…

  5. Managing low-level radioactive wastes: a proposed approach

    Microsoft Academic Search

    J. W. Peel; G. B. Levin

    1980-01-01

    In 1978, President Carter established the Interagency Review Group on Nuclear Waste Management (IRG) to review the nation's plans and progress in managing radioactive wastes. In its final report, issued in March 1979, the group recommended that the Department of Energy (DOE) assume responsibility for developing a national plan for the management of low-level wastes. Toward this end, DOE directed

  6. Assessment of recycling or disposal alternatives for radioactive scrap metal

    Microsoft Academic Search

    W. E. Murphie; M. J. Lilly; L. A. Nieves; S. Y. Chen

    1993-01-01

    The US Department of Energy, Office of Environmental Restoration and Waste Management, Oak Ridge Programs Division, is participating with the Organization for Economic Cooperation and Development in providing analytical support for evaluation of management alternatives for radioactive scrap metals. For this purpose, Argonne National Laboratory is assessing environmental and societal implications of recycling and\\/or disposal process alternatives. This effort includes

  7. Analysis of disposition alternatives for radioactively contaminated scrap metal

    Microsoft Academic Search

    L. A. Nieves; S. Y. Chen; E. J. Kohout; B. Nabelssi; R. W. Tilbrook; S. E. Wilson

    1997-01-01

    Millions of tonnes of slightly radioactive, scrap iron and steel, stainless steel, and copper are likely to become available as nuclear and other facilities and equipment are withdrawn from service. Disposition of this material is an international policy issue under consideration currently. The major alternatives for managing this material are to either develop a regulatory process for decontamination and recycling

  8. Analysis of disposition alternatives for radioactively contaminated scrap metal

    Microsoft Academic Search

    L. A. Nieves; S. Y. Chen; E. J. Kohout; B. Nabelssi; R. W. Tilbrook; S. E. Wilson

    1998-01-01

    Millions of tons of slightly radioactive scrap iron and steel, stainless steel, and copper are likely to become available as nuclear and other facilities and equipment are withdrawn from service. Disposition of this material is an international policy issue under consideration currently. The major alternatives for managing this material are either to develop a regulatory process for decontamination and recycling

  9. ALTERNATE MATERIALS IN DESIGN OF RADIOACTIVE MATERIAL PACKAGES

    SciTech Connect

    Blanton, P.; Eberl, K.

    2010-07-09

    This paper presents a summary of design and testing of material and composites for use in radioactive material packages. These materials provide thermal protection and provide structural integrity and energy absorption to the package during normal and hypothetical accident condition events as required by Title 10 Part 71 of the Code of Federal Regulations. Testing of packages comprising these materials is summarized.

  10. Spin Observables in Reactions with Radioactive Ion Beams

    SciTech Connect

    Galindo-Uribarri, Alfredo {nmn} [ORNL; Urrego Blanco, Juan Pablo [ORNL

    2007-01-01

    Polarization observables in nuclear reactions with exotic nuclei will provide important information concerning structural properties of nuclei and reaction mechanisms. We are currently engaged in exploring the use of polarization observables with radioactive ion beams and in the development of a polarized cryogenic target.

  11. Locating a Radioactive Waste Repository in the Ring of Fire

    Microsoft Academic Search

    Mick Apted; Kelvin Berryman; Neil Chapman; Mark Cloos; Chuck Connor; Kazumi Kitayama; Steve Sparks; Hiroyuki Tsuchi

    2004-01-01

    The scientific, technical, and sociopolitical challenges of finding a secure site for a geological repository for radioactive wastes have created a long and stony path for many countries. Japan carried out many years of research and development before taking its first steps in site selection. The Nuclear Waste Management Organization of Japan (NUMO) began looking for a high-level waste repository

  12. Distribution of radioactive cesium in edible parts of cattle.

    PubMed

    Okada, Keiji; Sato, Itaru; Deguchi, Yoshitaka; Morita, Shigeru; Yasue, Takeshi; Yayota, Masato; Takeda, Ken-Ichi; Sato, Shusuke

    2013-12-01

    After the disastrous incident of the Fukushima Daiichi Nuclear Power Station, various agricultural, livestock and fishery products have been inspected for radioactive contamination with cesium in Japan. In this study, radioactive cesium was measured in various edible parts of cattle to verify the current inspection method for cattle, in which the neck tissues are generally used as samples. Radioactive cesium concentration in the short plate, diaphragm, liver, lung, omasum, abomasum and small intestine were lower and sirloin, tenderloin, top round meat and tongue were higher than that in the neck. There was no significant difference between the other organs (heart, kidney, lumen and reticulum) and the neck. Ninety-five percent upper tolerance limits of the relative concentration to the neck were 1.88 for sirloin, 1.74 for tenderloin, 1.87 for top round and 1.45 for tongue. These results suggest that a safety factor of 2 is recommended for the radioactivity inspection of cattle to prevent a marketing of meat with higher cesium than the legal limit. Re-inspection should be conducted using another part of muscle, for example, top round, when suspicious levels of 50-100 Bq/kg are detected in the neck. PMID:23638759

  13. DISTRIBUTION AND EXCRETION OF RADIOACTIVE RARE EARTH COMPOUNDS IN MICE

    Microsoft Academic Search

    B. Rosoff; E. Siegel; G. Williams; H. Spencer

    1962-01-01

    The distribution and excretion of radioactive scandium, yttrium, ; lanthanum, and samarium, intravenously administered to mice in ionic and chelated ; form, are described. The strong rare earth chelates (ScEDTA and YEDTA) are well ; excreted and very little is retained in the tissues. The weak and intermediate ; chelates are largely deposited in liver and spleen, and the chelates

  14. Meteorological factors affecting spread of radioactivity from nuclear bombs

    Microsoft Academic Search

    Machta

    1957-01-01

    Meteorological considerations accounting for atmospheric dispersal of all types of radioactive particulate debris caused by a nuclear explosion are explored on local, intermediate, and delayed dispersement phases. Considerations for local dispersement, accounted for in a day or less, are: (1) relative time of fall, as a function of altitude, used to predict downward transfer of fall-out, (2) turbulent diffusion causing

  15. Protostellar Cosmic Rays and Extinct Radioactivities in Meteorites

    Microsoft Academic Search

    Typhoon Lee; Frank H. Shu; Hsien Shang; Alfred E. Glassgold; K. E. Rehm

    1998-01-01

    Calcium-aluminumârich inclusions (CAIs) and chondrules of chondritic meteorites may originate with the melting of dustballs launched by a magnetically driven bipolar outflow from the inner edge of the primitive solar nebula. Bombardment by protostellar cosmic rays may make the rock precursors of CAIs and chondrules radioactive, producing radionuclides found in meteorites that are difficult to obtain with other mechanisms. Reasonable

  16. Simulation of atmospheric dispersion of radioactivity from the Chernobyl accident

    SciTech Connect

    Lange, R.; Sullivan, T.J.; Gudiksen, P.H. (Lawrence Livermore National Lab., CA (USA))

    1989-07-01

    Measurements of airborne radioactivity over Europe, Japan, and the United States indicated that the release from the Chernobyl reactor accident in the Soviet Union on April 26, 1986 contained a wide spectrum of fission up to heights of 7 km or more within a few days after the initial explosion. This high-altitude presence of radioactivity would in part be attributable to atmospheric dynamics factors other than the thermal energy released in the initial explosion. Indications were that two types of releases had taken place -- an initial powerful explosion followed by days of a less energetic reactor fire. The Atmospheric Release Advisory Capability (ARAC) at the Lawrence Livermore National Laboratory (LLNL) utilized three-dimensional atmospheric dispersion models to determine the characteristics of the source term (release) and the evolution of the spatial distributions of the airborne radioactivity as it was transported over Europe and subsequently over the northern hemisphere. This paper describes the ARAC involvement and the results of the hemispheric model calculations which graphically depict the extensive dispersal of radioactivity. 1 fig.

  17. Measurement of radioactivity in bottled drinking water in Spain

    Microsoft Academic Search

    M. Palomo; A. Peñalver; F. Borrull; C. Aguilar

    2007-01-01

    The radioactive parameters in the Spanish regulations on water intended for human consumption (law decree 140\\/2003) have been determined in 30 different brands of some of the most common bottled mineral waters produced and consumed in Spain. These waters are not included in this legislation but if their consumption increases, the dose of radiation in the population may also increase.After

  18. A pill to treat people exposed to radioactive materials

    ScienceCinema

    Abergel, Rebecca

    2014-06-24

    Berkeley Lab's Rebecca Abergel discusses "A pill to treat people exposed to radioactive materials" in this Oct. 28, 2013 talk, which is part of a Science at the Theater event entitled Eight Big Ideas. Go here to watch the entire event with all 8 speakers:

  19. THE PRICE OF CONTAINING RADIOACTIVITY IN DIGGING CRATERS

    Microsoft Academic Search

    Murphey

    1958-01-01

    The possibility is considered that useful craters may be obtained by ; means of shallow underground explosions of thermonuclear devices. The price of ; containing radioactivity in such craters is considered for underground and ; surface bursts. Data obtained from Rainier Burst during Operation Plumbbob and ; from Operation Teapot are used as a basis for the calculations. (C.H.);

  20. Natural radioactivity levels in building materials used in Egypt

    NASA Astrophysics Data System (ADS)

    Ahmad, Fawzia

    All building materials contain various amounts of radioactive nuclides. The levels of natural radioactivity in 43 selected typical building materials used in the construction of walls, windows and doors were determined. For the first time, the radioactivity of iron was measured, revealing the existence of 60Co. A shielded high-purity germanium detector was used to measure the abundance of 226Ra, 232Th and 40K. The materials examined in this work showed radioactivity levels below the limit estimated from radium equivalent activity for acceptable radiation doses attributable to building materials, except for the fact that one gypsum sample showed higher levels of activity than average world levels. The studied building materials were classified according to the radium equivalent activities, which varied from highest to lowest levels as follows: clay, cement, brick, gypsum except from Abu-Zaabal, sand, wood, iron, glass and hydrated lime The existence of the 137Cs isotope in some building materials was confirmed and its concentration levels were determined (ranging from 0.04 to 21.156 Bq kg-1). The alpha-activity of radon was measured in a number of building materials using CR-39 detectors.

  1. Simulating the venting of radioactivity from a soviet nuclear test

    NASA Astrophysics Data System (ADS)

    Rodriguez, Daniel J.; Peterson, Kendall R.

    Fresh fission products were found in several routine air samples in Europe during the second and third weeks of March 1987. Initially, it was suspected that the radionuclides, principally 133Xe and 131I, had been accidentally released from a European facility handling nuclear materials. However, the announcement of an underground nuclear test at Semipalatinsk, U.S.S.R. on 26 February 1987 suggested that the elevated amounts of radioactivity may, instead, have been caused by a venting episode. Upon learning of these events, we simulated the transport and diffusion of 133Xe with our Hemispheric MEDIC and ADPIC models, assuming Semipalatinsk to be the source of the radioactive emissions. The correspondence between the calculated concentrations and the daily average 133Xe measurements made by the Federal Office for Civil Protection in F.R.G. was excellent. While this agreement does not, in itself, prove that an atmospheric venting of radioactive material occurred at Semipalatinsk, a body of circumstantial evidence exists which, when added together, strongly supports this conclusion. Our calculations suggested a total fission yield of about 40 kt, which is within the 20-150 kt range of tests acknowledged by the U.S.S.R. Finally, dose calculations indicated that no health or environmental impact occurred outside of the U.S.S.R. due to the suspected venting of 133Xe. However, the inhalation dose resulting from 133I, an unmodeled component of the radioactive cloud, represented a greater potential risk to public health.

  2. Preparation of radioactive rare earth targets for neutron capture study

    Microsoft Academic Search

    G. G. Miller; P. Z. Rogers; P. Palmer; D. Dry; R. Rundberg; M. Fowler; J. Wilhelmy

    2005-01-01

    Summary  The neutron capture behavior of certain radioactive rare earth nuclides, among them 171Tm and 151Sm, is of interest for astrophysical reasons and for the interpretation of radiochemical data from underground nuclear tests. In order to measure neutron capture excitation functions for these radionuclides, targets were produced that met stringent requirements. This paper describes the purification chemistry and target preparation methods

  3. Plasma separation process: Disposal of PSP radioactive wastes

    SciTech Connect

    Not Available

    1989-07-01

    Radioactive wastes, in the form of natural uranium contaminated scrap hardware and residual materials from decontamination operations, were generated in the PSP facilities in buildings R1 and 106. Based on evaluation of the characteristics of these wastes and the applicable regulations, the various options for the processing and disposal of PSP radioactive wastes were investigated and recommended procedures were developed. The essential features of waste processing included: (1) the solidification of all liquid wastes prior to shipment; (2) cutting of scrap hardware to fit 55-gallon drums and use of inerting agents (diatomaceous earth) to eliminate pyrophoric hazards; and (3) compaction of soft wastes. All PSP radioactive wastes were shipped to the Hanford Site for disposal. As part of the waste disposal process, a detailed plan was formulated for handling and tracking of PSP radioactive wastes, from the point of generation through shipping. In addition, a waste minimization program was implemented to reduce the waste volume or quantity. Included in this document are discussions of the applicable regulations, the types of PSP wastes, the selection of the preferred waste disposal approach and disposal site, the analysis and classification of PSP wastes, the processing and ultimate disposition of PSP wastes, the handling and tracking of PSP wastes, and the implementation of the PSP waste minimization program. 9 refs., 1 fig., 8 tabs.

  4. Research on uranium deposits as analogies of radioactive waste repositories

    Microsoft Academic Search

    1988-01-01

    The disposal of highly radioactive waste deep underground in suitable geological formations is proposed by many countries to protect public health and safety. The study of natural analogies of nuclear waste repositories is one method of validating mathematical models and assuring that a proposed repository site and design will be safe. Since 1981, the AAEC has studied the major uranium

  5. Hazardous and radioactive waste: Public health issues and concerns

    Microsoft Academic Search

    1987-01-01

    The Uranium Mill Tailings Remedial Action Project (UMTRAP), managed by the USDOE, requires radioactive materials cleanup at numerous private properties and mill sites throughout the United States. To enhance public relations, Chem-Nuclear Systems (CNSI) and MK-Ferguson Company present a unique training and information program, allowing local individuals to understand and evaluate the relative hazards of the work. This paper describes

  6. A New Plant for Management of Radioactive Waste

    Microsoft Academic Search

    F. Schumann; G. Pfefferkorn; M. Loose

    1990-01-01

    By 1991 a new plant for management of radioactive waste will be erected in the CINR. Thus increased atomic safety and radiation protection will be attained, the economy of waste management and the quality of the conditioned waste will simultaneously be improved. Facilities for volume reduction (evaporation, press compaction, solidification) and conditioning (solidification, packing) will be available for the treatment

  7. Have the sharps been used with RADIOACTIVE MATERIALS?

    E-print Network

    Have the sharps been used with RADIOACTIVE MATERIALS? DISPOSAL: · Place all lab glass items as this poses a potential health and safety hazard to personnel during trash handling and pickup. All sharps containers are available close to where sharps waste is generated. Do not overfill sharps containers

  8. Self-closing shielded container for use with radioactive materials

    DOEpatents

    Smith, J.E.

    1984-10-16

    A container is described for storage of radioactive material comprising a container body and a closure member. The closure member being coupled to the container body to enable the closure body to move automatically from a first position (e.g., closed) to a second position (open). 1 fig.

  9. Self-closing shielded container for use with radioactive materials

    DOEpatents

    Smith, Jay E. (Pittsburgh, PA)

    1984-01-01

    A container for storage of radioactive material comprising a container body nd a closure member. The closure member being coupled to the container body to enable the closure body to move automatically from a first position (e.g., closed) to a second position (open).

  10. RadioActivity and the Law of Conservation of Mass

    Microsoft Academic Search

    O. W. Richardson

    1904-01-01

    MR. SODDY in the Wilde lecture on the ``Evolution of Matter as Revealed by the Radio-active Elements'' (Proc. Manchester Phil. Soc., vol. xlviii., part ii., p. 29) gives two methods of deducing the average life of a radium atom. The results become concordant if we assume that the complete disintegration of an atom of radium involves the emission of four

  11. Conversion of radioactive ferrocyanide compounds to immobile glasses

    Microsoft Academic Search

    W. W. Schulz; A. L. Dressen

    1977-01-01

    Complex radioactive ferrocyanide compounds result from the scavenging of cesium from waste products produced in the chemical reprocessing of nuclear fuel. These ferrocyanides, in accordance with this process, are converted to an immobile glass, resistant to leaching by water, by fusion together with sodium carbonate and a mixture of (a) basalt and boron trioxide (BâOâ) or (b) silica (SiOâ) and

  12. Development of an automatic handling system for radioactive waste

    Microsoft Academic Search

    D Rosli; S M Shalina; A R Anwar; H Mohd Zaid; K Mohd Ashhar

    2011-01-01

    This paper presents the development of Radioactive Waste Automatic Handling System (RWAHS). It is developed to minimise the human exposure to radiation during handling process. The development consists of conceptual simulation, control design, handling mechanism, storage and retrieval system and storage structure. The conceptual design was done using CATIA design and modelling to analyse the suitable mechanism. The control system

  13. Metamict mineral alteration: an implication for radioactive waste disposal.

    PubMed

    Ewing, R C

    1976-06-25

    Pervasive alteration is a common feature of metamict minerals. Previous studies of metamict niobium-tantalum-titanium oxides and electron microprobe analyses of altered areas in metamict yttrialite document the leaching of uranium, thorium, and rare earth elements. These data suggest that glasses may not provide a stable medium for radioactive waste disposal. PMID:17739840

  14. Transport Models for Radioactive Carbon Dioxide at RWMC

    SciTech Connect

    Hull, Laurence Charles; Hohorst, Frederick August

    2001-12-01

    Radioactive carbon dioxide (formed by oxidation of carbon-14) is a highly mobile, radioactive contaminant released from solid wastes buried at the Subsurface Disposal Area (SDA) at the Radioactive Waste Management Complex (RWMC) at the Idaho National Engineering and Environmental Laboratory (INEEL). Radioactive CO2 is chemically active in the environment, volatile, water soluble, and subject to adsorption on solids. For this reason, its fate must be understood and controlled to meet radiological requirements (protection of the atmosphere, aquifer, vadose zones, plants and animals). In the present work, the migration of carbon-14 as dissolved bicarbonate was studied using miscible displacement experiments in water-saturated columns containing sediments from RWMC. Dissolved carbon-14 was retarded relative to the movement of water by a factor of about 3.6, which translates to a partition coefficient (Kd) of 0.8 ml/g. Two different adsorption sites were identified, with one site possibly having a nonlinear adsorption isotherm. A conservative tracer gas, sulfur hexafluoride, was used to measure the tortuosity of sedimentary material for gaseous diffusion. The tortuosity of the RWMC sediment (Spreading Area B sediment) was determined to be 3.2, which is slightly greater than predicted by the commonly used Millington-Quirk equation. In terms of affecting the migration of carbon-14 to the aquifer, the relative importance of the parameters studied is: (1) natural moisture content of the sediments, (2) sediment tortuosity to gas-phase diffusion, and (3) adsorption onto solid phases.

  15. Rain Scavenging of Radioactive Particulate Matter from the Atmosphere

    Microsoft Academic Search

    S. M. Greenfield

    1957-01-01

    On the basis of Langmuir's theory of collection efficiencies, a model is derived to explain the removal of radioactive particulate matter from the atmosphere by rain. In this connection, Langmuir's collection efficiencies are modified to take into account the density of the solid particles, and are adjusted to express the fraction removed from a vertical cylinder of constant diameter. It

  16. Simulation Of Radioactive Release In Muria Peninsula Using Hysplit Model

    Microsoft Academic Search

    Teuku Alfa

    SIMULATION OF RADIOACTIVE RELEASE IN MURIA PENINSULA USING HYSPLIT MODEL. A nuclear accident, assumed to occur in Muria Peninsula, has been analyzed. Source term was calculated for Westinghouse PWR model 412 four-loop plant, that is assumed the reactor has been operated for 365, 440, 730 and 880 days at nominal power of 3339 MW thermal before the core was damaged

  17. Imagine the Universe: Radioactive Decay in Supernova Remnants

    NSDL National Science Digital Library

    This site explains how supernovae can be detected and studied by measuring the decay of radioactive elements in the material ejected from them. It is part of the Goddard Space Flight Center's "Imagine the Universe" website, created by GSFC's Laboratory for High Energy Astrophysics. It includes text, remotely sensed imagery, and links to other topics related to high energy astrophysics.

  18. ANNUAL REPORT. ACTINIDE-ALUMINATE SPECIATION IN ALKALINE RADIOACTIVE WASTE

    EPA Science Inventory

    Highly alkaline radioactive waste tanks contain a number of transuranic species, in particular U, Np, Pu, and Am-the exact forms of which are currently unknown. Knowledge of actinide speciation under highly alkaline conditions is essential towards understanding and predicting the...

  19. Measurement of Alpha Radioactivity in Some Building Construction Materials

    Microsoft Academic Search

    MONIKA GUPTA; MAMTA SAINI; R. P. CHAUHAN

    Natural radioactivity is wide spread in the earth's environment and it exists in various geological formations in soils, rocks, plants, water and air. The growing worldwide interest in natural radiation exposure has lead to extensive surveys in many countries. The building materials like bricks, concrete, sand, cement etc. are earth based, containing uranium and thorium in varying amounts which are

  20. Radioactive wastes from uranium mining enterprises and their environmental effects

    Microsoft Academic Search

    V. N. Mosinets

    1991-01-01

    content in the ore and the activity of the geochemical processes occurring in the deposit prior to mining, particularly natural leaching resulting from the shift in the equilibrium of uranium with regard to its decay products [i]. The level of radioactivity of the wastes from the exploitation of known uranium deposits is usually low, especially if it is compared with