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Sample records for bohemian uranium miners

  1. The Rožná uranium deposit (Bohemian Massif, Czech Republic): shear zone-hosted, late Variscan and post-Variscan hydrothermal mineralization

    NASA Astrophysics Data System (ADS)

    Kříbek, Bohdan; Žák, Karel; Dobeš, Petr; Leichmann, Jaromír; Pudilová, Marta; René, Miloš; Scharm, Bohdan; Scharmová, Marta; Hájek, Antonín; Holeczy, Daniel; Hein, Ulrich F.; Lehmann, Bernd

    2009-01-01

    Three major mineralization events are recorded at the Rožná uranium deposit (total mine production of 23,000 t U, average grade of 0.24% U): (1) pre-uranium quartz-sulfide and carbonate-sulfide mineralization, (2) uranium, and (3) post-uranium quartz-carbonate-sulfide mineralization. (1) K-Ar ages for white mica from wall rock alteration of the pre-uranium mineralization style range from 304.5 ± 5.8 to 307.6 ± 6.0 Ma coinciding with the post-orogenic exhumation of the Moldanubian orogenic root and retrograde-metamorphic equilibration of the high-grade metamorphic host rocks. The fluid inclusion record consists of low-salinity aqueous inclusions, together with H2O-CO2-CH4, CO2-CH4, and pure CH4 inclusions. The fluid inclusion, paragenetic, and isotope data suggest that the pre-uranium mineralization formed from a reduced low-salinity aqueous fluid at temperatures close to 300°C. (2) The uraniferous hydrothermal event is subdivided into the pre-ore, ore, and post-ore substages. K-Ar ages of pre-ore authigenic K-feldspar range from 296.3 ± 7.5 to 281.0 ± 5.4 Ma and coincide with the transcurrent reorganization of crustal blocks of the Bohemian Massif and with Late Stephanian to Early Permian rifting. Massive hematitization, albitization, and desilicification of the pre-ore altered rocks indicate an influx of oxidized basinal fluids to the crystalline rocks of the Moldanubian domain. The wide range of salinities of fluid inclusions is interpreted as a result of the large-scale mixing of basinal brines with meteoric water. The cationic composition of these fluids indicates extensive interaction with crystalline rocks. Chlorite thermometry yielded temperatures of 260°C to 310°C. During this substage, uranium was probably leached from the Moldanubian crystalline rocks. The hydrothermal alteration of the ore substage followed, or partly overlapped in time, the pre-ore substage alteration. K-Ar ages of illite from ore substage alteration range from 277.2 ± 5.5 to

  2. Age and mineralogy of supergene uranium minerals — Tools to unravel geomorphological and palaeohydrological processes in granitic terrains (Bohemian Massif, SE Germany)

    NASA Astrophysics Data System (ADS)

    Dill, H. G.; Gerdes, A.; Weber, B.

    2010-04-01

    Uranyl phosphates (torbernite, autunite, uranocircite, saleeite) and hydrated uranyl silicates (normal and beta-uranophane) found in various erosion levels and structures in the Late Variscan granites at the western edge of the Bohemian Massif, Germany, were the target of mineralogical investigations and age dating, using conventional and more advanced techniques such as Laser-Ablation-Inductive-Coupled-Plasma Mass Spectrometry (LA-ICP-MS). Supergene U minerals have an edge over other rock-forming minerals for such studies, because of their inherent ‘clock’ and their swift response to chemical and physical environmental changes on different scales. Uraniferous phoscretes and silcretes, can be used to characterize the alkalinity/acidity of meteoric/per descensum fluids and to constrain the redox conditions during geomorphic processes. This study aims to decipher the geomorphological and palaeohydrological regime that granitic rocks of the Central European Variscides (Moldanubian and Saxothuringian zones) went through during the Neogene and Quaternary in the foreland of the rising Alpine mobile fold belt. The study provides an amendment to the current sub-division of the regolith by introducing the term “hydraulith”, made up of percolation and infiltration zones, for the supergene alteration zone in granitic terrains. It undercuts the regolith at the brink of the phreatic to vadose hydrological zones. Based upon the present geomorphological and mineralogical studies a four-stage model is proposed for the evolution of the landscape in a granitic terrain which might also be applicable to other regions of the European Variscides, considering the hydrological facies changes along with paleocurrent and paleoslope in the basement and the development of the fluvial drainage system in the foreland. Stage I (U mineralization in the infiltration zone) is a mirror image of the relic granitic landscape with high-altitude divides and alluvial-fluvial terraces. Its

  3. Possible uranium mineralization, Mineral Mountains, Utah

    USGS Publications Warehouse

    Miller, W. Roger; McHugh, John B.; Ficklin, Walter H.

    1979-01-01

    The Mineral Mountains block in west-central Utah is a horst whose core stands structurally high relative to all nearby basin-and-range fault blocks. Rocks of the Mineral Mountains range from Precambrian to Quaternary in age, but mostly consist of Tertiary granitic rocks. The range lies with the Wah Wah-Tusher mineral belt. Lead, silver, gold, and tungsten have been mined commercially. During a geochemical survey conducted in the summer of 1978, 30 water samples and 29 stream-sediment samples were collected from the Mineral Mountains area. The interpretation of simple plots of uranium concentrations and the results of a Q-mode factor analysis indicate that potential exists for uranium mineral deposits within the Mineral Mountains. The most favorable areas are in the granitic pluton near its contacts with sedimentary and metamorphic rocks. The most likely source of the uranium anomalies is uraninite-bearing epigenic veins along faults and fractures within the pluton. Three hypothetical models are proposed to account for the uranium mineralization.

  4. Structural changes in amber due to uranium mineralization.

    PubMed

    Havelcová, Martina; Machovič, Vladimír; Mizera, Jiří; Sýkorová, Ivana; René, Miloš; Borecká, Lenka; Lapčák, Ladislav; Bičáková, Olga; Janeček, Oldřich; Dvořák, Zdeněk

    2016-07-01

    The presence of uranium, with a bulk mass fraction of about 1.5 wt% and radiolytic alterations are a feature of Cenomanian amber from Křižany, at the northeastern edge of the North Bohemian Cretaceous uranium ore district. Pores and microcracks in the amber were filled with a mineral admixture, mainly in the form of Zr-Y-REE enriched uraninite. As a result of radiolytic alterations due to the presence of uranium, structural changes were observed in the Křižany amber in comparison with a reference amber from Nové Strašecí in central Bohemia; this was of similar age and botanical origin but did not contain elevated levels of uranium. Structural changes involved an increase in aromaticity due to dehydroaromatization of aliphatic cyclic hydrocarbons, loss of oxygen functional groups, an increase in the degree of polymerization, crosslinking of CC bonds, formation of a three-dimensional hydrocarbon network in the bulk organic matrix, and carbonization of the organic matrix around the uraninite infill. PMID:27085038

  5. Mortality among Navajo uranium miners.

    PubMed Central

    Roscoe, R J; Deddens, J A; Salvan, A; Schnorr, T M

    1995-01-01

    OBJECTIVES. To update mortality risks for Navajo uranium miners, a retrospective cohort mortality study was conducted of 757 Navajos from the cohort of Colorado Plateau uranium miners. METHODS. Vital status was followed from 1960 to 1990. Standardized mortality ratios were estimated, with combined New Mexico and Arizona non-White mortality rates used for comparison. Cox regression models were used to evaluate exposure-response relationships. RESULTS. Elevated standardized mortality ratios were found for lung cancer (3.3), tuberculosis (2.6), and pneumoconioses and other respiratory diseases (2.6). Lowered ratios were found for heart disease (0.6), circulatory disease (0.4), and liver cirrhosis (0.5). The estimated relative risk for a 5-year duration of exposure vs none was 3.7 for lung cancer, 2.1 for pneumoconioses and other respiratory diseases, and 2.0 for tuberculosis. The relative risk for lung cancer was 6.9 for the midrange of cumulative exposure to radon progeny compared with the least exposed. CONCLUSIONS. Findings were consistent with those from previous studies. Twenty-three years after their last exposure to radon progeny, these light-smoking Navajo miners continue to face excess mortality risks from lung cancer and pneumoconioses and other respiratory diseases. PMID:7702118

  6. Uranium mineralization in southern Victoria Land, Antarctica

    SciTech Connect

    Dreschhoff, G.A.M.; Zeller, E.J.

    1986-01-01

    For the past 10 antarctic field seasons, an airborne gamma-ray spectrometric survey has been conducted over widely separated parts of the continent. Localized accumulations of both primary and secondary uranium minerals have been discovered at several localities scattered along the Transantarctic Mountains from the Scott Glacier to northern Victoria Land. A number of highly significant radiation anomalies have been discovered in the area between the Koettlitz Glacier and the Pyramid Trough. The occurrences consist of pegmatite vein complexes which contain an association of primary uranium and thorium minerals. Of still greater significance is the fact that abundant secondary uranium minerals were found in association with the primary deposits, and they indicate clearly that uranium is geochemically mobile under the conditions imposed by the arid polar climate that now exists in southern Victoria Land. Preliminary results of a uranium analysis performed by neutron activation indicate a concentration of 0.12% uranium in a composite sample from the two veins. Even higher levels of thorium are present. The nature of the primary uranium mineralization is currently under investigation. Preliminary results are discussed.

  7. Lung cancer among Navajo uranium miners

    SciTech Connect

    Gottlieb, L.S.; Husen, L.A.

    1982-04-01

    Lung cancer has been a rare disease among the Indians of the southwestern United States. However, the advent of uranium mining in the area has been associated with an increased incidence of lung cancer among Navajo uranium miners. This study centers on Navajo men with lung cancer who were admitted to the hospital from February 1965 to May 1979. Of a total of 17 patients with lung cancer, 16 were uranium miners, and one was a nonminer. The mean value of cumulative radon exposure for this group was 1139.5 working level months (WLMs). The predominant cancer type was the small cell undifferentiated category (62.5 percent). The low frequency of cigarette smoking in this group supports the view that radiation is the primary cause of lung cancer among uranium miners and that cigarette smoking acts as a promoting agent.

  8. Uranium miner lung cancer study. Final report

    SciTech Connect

    Saccomanno, G.

    1986-06-01

    This study on uranium miners was started in 1957 and extended through June 30, 1986. It consisted of the routine screening of sputum from uranium miners of the Colorado Plateau, and collection of surgical and autopsy material from uranium miners who developed lung cancer. The projects resulted in: (1) Proof, for the first time, that cancer takes from 10 to 15 years to develop from the maximum accumulated carcinogenic insult and can be demonstrated through progressive cellular changes of the bronchial tree; (2) Development of a method for preserving, concentrating, and processing sputum samples. This is known as the Saccomanno Technique, and is used worldwide in diagnosing lung cancer; (3) Publication of the 1st and 2nd editions of a full-color textbook entitled ''Diagnostic Pulmonary Cytology;'' (4) Presentation of conclusive data on the effects of cigarette smoking and alpha progeny radiation on uranium miners, and information on safe radiation exposure levels; (5) Development of a brush-wash tube for collecting, concentrating, and preparing bronchial brushings and washings; (6) Development of cytological criteria which has improved sensitivity from 30% to about 60%; (7) Development of criteria for cytologic identification of carcinoma in situ, making it possible to diagnose lung cancer before it can be detected on chest x-ray.

  9. Evolution of uranium and thorium minerals

    NASA Astrophysics Data System (ADS)

    Hazen, R. M.; Ewing, R. C.; Sverjensky, D. A.

    2009-12-01

    The origins and near-surface distributions of the approximately 250 known uranium and/or thorium minerals elucidate principles of mineral evolution. This history can be divided into four phases. The first, from ~4.5 to 3.5 Ga, involved successive concentrations of uranium and thorium from their initial uniform trace distribution into magmatic-related fluids from which the first U4+ and Th4+ minerals, uraninite (UO2), thorianite (ThO2) and coffinite (USiO4), precipitated in the crust. The second period, from ~3.5 to 2.2 Ga, saw the formation of large low-grade concentrations of detrital uraninite (containing several weight percent Th) in the Witwatersrand-type quartz-pebble conglomerates deposited in a highly anoxic fluvial environment. Abiotic alteration of uraninite and coffinite, including radiolysis and auto-oxidation caused by radioactive decay and the formation of helium from alpha particles, may have resulted in the formation of a limited suite of uranyl oxide-hydroxides. Earth’s third phase of uranium mineral evolution, during which most known U minerals first precipitated from reactions of soluble uranyl (U6+O2)2+ complexes, followed the Great Oxidation Event (GOE) at ~2.2 Ga and thus was mediated indirectly by biologic activity. Most uraninite deposited during this phase was low in Th and precipitated from saline and oxidizing hydrothermal solutions (100 to 300°C) transporting (UO2)2+-chloride complexes. Examples include the unconformity- and vein-type U deposits (Australia and Canada) and the unique Oklo natural nuclear reactors in Gabon. The onset of hydrothermal transport of (UO2)2+ complexes in the upper crust may reflect the availability of CaSO4-bearing evaporites after the GOE. During this phase, most uranyl minerals would have been able to form in the O2-bearing near-surface environment for the first time through weathering processes. The fourth phase of uranium mineralization began approximately 400 million years ago, as the rise of land plants

  10. EXAFS studies of uranium sorption on layer-silicate minerals

    SciTech Connect

    Hudson, E.A.; Terminello, L.J.; Viani, B.E.

    1995-12-31

    The local structure of uranium sorbed on mineral surfaces was investigated by uranium L{sub 3}-edge EXAFS. Solutions of uranyl chloride, UO{sub 2}Cl{sub 2}, were exposed to vermiculite, an expansible layer silicate mineral, under conditions which favor sorption by either cation exchange or surface complexation. EXAFS of the resulting mineral samples indicates a larger distortion of the uranyl equatorial shell for cation exchange, possibly due to steric effects of interlayer sorption. The uranyl U-O axial bond distance is greater for surface complexation than for ion exchange. Uranyl sorption on talc and pyrophyllite, layer silicate minerals with essentially no cation-exchange capacity, gives results which generally support the trends for surface complexation on vermiculite.

  11. Lung cancer in a nonsmoking underground uranium miner.

    PubMed Central

    Mulloy, K B; James, D S; Mohs, K; Kornfeld, M

    2001-01-01

    Working in mines is associated with acute and chronic occupational disorders. Most of the uranium mining in the United States took place in the Four Corners region of the Southwest (Arizona, Colorado, New Mexico, and Utah) and on Native American lands. Although the uranium industry collapsed in the late 1980s, the industry employed several thousand individuals who continue to be at increased risk for developing lung cancers. We present the case of a 72-year-old Navajo male who worked for 17 years as an underground uranium miner and who developed lung cancer 22 years after leaving the industry. His total occupational exposure to radon progeny was estimated at 506 working level months. The miner was a life-long nonsmoker and had no other significant occupational or environmental exposures. On the chest X-ray taken at admission into the hospital, a right lower lung zone infiltrate was detected. The patient was treated for community-acquired pneumonia and developed respiratory failure requiring mechanical ventilation. Respiratory failure worsened and the patient died 19 days after presenting. On autopsy, a 2.5 cm squamous cell carcinoma of the right lung arising from the lower lobe bronchus, a right broncho-esophageal fistula, and a right lower lung abscess were found. Malignant respiratory disease in uranium miners may be from several occupational exposures; for example, radon decay products, silica, and possibly diesel exhaust are respiratory carcinogens that were commonly encountered. In response to a growing number of affected uranium miners, the Radiation Exposure Compensation Act (RECA) was passed by the U.S. Congress in 1990 to make partial restitution to individuals harmed by radiation exposure resulting from underground uranium mining and above-ground nuclear tests in Nevada. PMID:11333194

  12. Lung cancer epidemiology in New Mexico uranium miners

    SciTech Connect

    Samet, J.M.

    1991-11-01

    This investigation assesses the health effects of radon progeny exposure in New Mexico uranium miners. Cumulative exposures sustained by most New Mexico miners are well below those received earlier in the Colorado Plateau. This project utilizes the research opportunity offered by New Mexico miners to address unresolved issues related to radon progeny exposure: (1) the lung cancer risk of lower levels of exposure, (2) interaction between radon progeny exposure and cigarette smoking in the causation of lung cancer, (3) the relationship between lung cancer histologic type and radon progeny exposure, and (4) possible effects of radon progeny exposure other than lung cancer. A cohort study of 3800 men with at least one year of underground uranium mining experience in New Mexico is in progress. Results are discussed.

  13. Detection of trisomy 7 in bronchial cells from uranium miners

    SciTech Connect

    Lechner, J.F.; Neft, R.E.; Belinsky, S.A.

    1995-12-01

    New Mexico was the largest producer of uranium in the western world during 1960s and 1970s. Investigators at the University of New Mexico School of Medicine`s Epidemiology and Cancer Control Program have been conducting epidemiological studies on uranium miners over the past 2 decades. Currently, this cohort includes more than 3600 men who had completed at least 1 y of underground work experience in New Mexico by December 31, 1976. These miners, who are now in their 5th through 7th decades, the age when lung cancer incidence is highest, are at high risk for developing this disease because they were exposed to high levels of radon progeny in the mines, and they also smoked tobacco. However, not all people comparably exposed develop lung cancer; in fact, the lifetime risk of lung cancer for the smoking uranium miners has been projected by epidemiological analyses to be no higher than 50%. Therefore, the identification of gene alterations in bronchial epithelium would be a valuable tool to ascertain which miners are at greatest risk for lung cancer. The underlying significance of the current effort confirms the hypothesis that chronic exposure to high concentrations of {alpha}-particles and tobacco smoke produces genetically altered lung epithelial cells throughout the respiratory tract of some susceptible individuals before they develop clinical disease.

  14. A modelling study on the fractionation of uranium among minerals during rock weathering

    SciTech Connect

    Ohnuki, Toshihiko; Murakami, Takashi; Yanase, Nobuyuki

    1993-12-31

    A modelling study has been carried out to understand the effect of rock alteration on the fractionation of uranium among coexisting minerals (chlorite, vermiculite, kaolinite, amorphous and crystalline iron minerals) at the Koongarra ore deposit, Australia. The model considers the chlorite weathering process, its mechanism and rate, and assumes the presence of reversible and irreversible sorption sites in the secondary minerals. The calculated uranium concentrations at the two different sites in the minerals were compared with the results of sequential extraction experiments. Good agreement between the calculated and observed uranium concentrations was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of the altered clay minerals. However, a conventional K{sub d} model gave inconsistent uranium concentrations. The calculated results show that the crystalline iron minerals sorb uranium during all stages of weathering, and that the uranium fractionation among the minerals varies with time until the end of the weathering.

  15. Alteration and vein mineralization, Schwartzwalder uranium deposit, Front Range, Colorado

    USGS Publications Warehouse

    Wallace, Alan R.

    1983-01-01

    The Schwartzwalder uranium deposit, in the Front Range west of Denver, Colorado, is the largest vein-type uranium deposit in the United States. The deposit is situated in a steeply dipping fault system that cuts Proterozoic metamorphic rocks. The host rocks represent a submarine volcanic system with associated chert and iron- and sulfide-rich pelitic rocks. Where faulted, the more competent garnetiferous and quartzitic units behaved brittlely and created a deep, narrow conduit. The ores formed 70-72 m.y. ago beneath 3 km of Phanerozoic sedimentary rocks. Mineralization included two episodes of alteration and three stages of vein-mineralization. Early carbonate-sericite alteration pseudomorphically replaced mafic minerals, whereas the ensuing hematite-adularia episode replaced only the earlier alteration assemblage. Early vein mineralization produced a minor sulfide-adularia-carbonate assemblage. Later vein mineralization generated the uranium ores in two successive stages. Carbonates, sulfides, and adularia filled the remaining voids. Clastic dikes composed of fault gouge and, locally, ore were injected into new and existing fractures. Geologic and chemical evidence suggest that virtually all components of the deposit were derived from major hornblende gneiss units and related rocks. The initial fluids were evolved connate/metamorphic water that infiltrated and resided along the extensive fault zones. Complex fault movements in the frontal zone of the eastern Front Range caused the fluids to migrate to the most permeable segments of the fault zones. Heat was supplied by increased crustal heat flow related to igneous activity in the nearby Colorado mineral belt. Temperatures decreased from 225?C to 125?C during later mineralization, and the pressure episodically dropped from 1000 bars. The CO2 fugacity was initially near 100 bars, and uranium was carried as a dicarbonate complex. Sudden decreases in confining pressure during fault movement caused evolution of CO2

  16. Mining death: Cancer among America`s uranium miners

    SciTech Connect

    Ball, H.

    1995-10-01

    The approach the author takes in this book is that American uranium miners suffered unnecessary severe, often fatal, health problems because of their exposure to radiation. More than half the book reprints a 1986 report from the Committee on Energy and Commerce titled `America`s Nuclear Guinea Pigs: three Decades of Radiation Experiments on U.S. Citizens.` The book continues well documented history of the nuclear era.

  17. Alteration and vein mineralization, Ladwig uranium mine, Jefferson County, Colorado

    USGS Publications Warehouse

    Wallace, Alan R.

    1979-01-01

    Uranium ore at the Ladwig mine, Jefferson County, Colo., occurs in steeply dipping, northwest-striking faults and related fractures with a carbonate-adularia assemblage that forms in altered wallrocks and fills veins. The faults occur between large intrusive pegmatites and garnetiferous gneisses of Precambrian age, and were reactivated as the result of the early Paleocene uplift of the Front Range foothills. Mineralization in the deposit includes both wallrock alteration and vein filling. Alteration was intense but local, and chiefly involved the carbonatization of mafic minerals in the wallrocks. Felsic minerals in the wallrocks are relatively unaltered. The veins are filled with an adularia-pitchblende-carbonate assemblage with minor related sulfides and coffinite. Many of the iron-bearing carbonates in both the alteration and vein assemblages have been altered to hematite. The mineralization and alteration are believed to have formed in response to initially high amounts of CO2 and the subsequent release of dissolved CO2 by boiling or effervescence. Uranium, carried in a dicarbonate complex, was precipitated directly as pitchblende when the CO2 was released. The expulsion of H+ during boiling created a net oxidizing environment which oxidized the iron-bearing carbonates. Late stage calcite and sulfides were deposited in existing voids in the veins.

  18. Behavior of Colorado Plateau uranium minerals during oxidation

    USGS Publications Warehouse

    Garrels, Robert Minard; Christ, C.L.

    1956-01-01

    Uranium occurs as U(VI) and U(IV) in minerals of the Colorado Plateau ores. The number of species containing U(VI) is large, but only two U(IV) minerals are known from the Plateau: uraninite, and oxide, and coffinite, a hydroxy-silicate. These oxidize to yield U(VI) before reacting significantly with other mineral constituents. Crystal-structure analysis has shown that U(VI) invariable occurs as uranyl ion, UO2+2. Uranyl ion may form complex carbonate or sulfate ions with resulting soluble compounds, but only in the absence of quinquevalent vanadium, arsenic, or phosphorous. In the presence of these elements in the +5 valence state, the uranyl ion is fixed in insoluble layer compounds formed by union of uranyl ion with orthovanadate, orthophosphate, or orthoarsenate. Under favorable conditions UO2+2 may react to form the relatively insoluble rutherfordine, UO2CO3, or hydrated uranyl hydroxides. These are rarely found on the Colorado Plateau as opposed to their excellent development in other uraniferous areas, a condition which is apparently related to the semiarid climate and low water table of the Plateau. Uranium may also be fixed as uranyl silicate, but little is known about minerals of this kind. In the present study emphasis has been placed on a detailing of the chemical and crystal structural changes which occur in the oxidation paragenetic sequence.

  19. X-ray powder data for uranium and thorium minerals

    USGS Publications Warehouse

    Frondel, Clifford; Riska, Daphne; Frondel, Judith Weiss

    1956-01-01

    The U.S. Geological Survey has in preparation a comprehensive volume on the mineralogy of uranium and thorium. This work has been done as part of a continuing systematic survey of data on uranium and thorium minerals on behalf of the Division of Raw Materials, U.S. Atomic Energy Commission. Pending publication of this volume and in response to a widespread demand among workers in uranium and thorium mineralogy, the X-ray powder diffraction data for the known minerals that contain uranium or thorium as an essential constituent are presented here. The coverage is complete except for a few minerals for which there are no reliable data owing to lack of authentic specimens. With the exception of that for ianthinite, the new data either originated in the Geological Survey or in the Mineralogical Laboratory of Harvard University. Data from the literature or other sources were cross-checked against the files of standard patterns of these laboratories; the sources are indicated in the references. Data not accompanied by a reference were obtained from films in the Harvard Standard File and cross-checked as to the identity of the film with the Geological Survey's file. Minor differences can be expected in the d-spacings reported for the same specimens by different investigators because of the manner of preparation of the mount, the conditions of X-ray irradiation, and the method of photography and measurement of the film or chart. The Harvard and Geological Survey data all were obtained from films taken in 114-mm diameter cameras, using either ethyl cellulose and toluene or collodion spindle mounts and Straumanis-type film mounting. Unless otherwise indicated all patterns were taken with copper radiation (Kα 1.5418 A.) and nickel filter and data are given in Angstrom units. The d-spacings are not corrected for film shrinkage. The correction ordinarily is small and in general is less than either the variation in spacing arising from differences in experimental technique of

  20. Mineral transformations during the dissolution of uranium ore minerals by dissimilatory metal-reducing bacteria

    NASA Astrophysics Data System (ADS)

    Glasauer, S.; Weidler, P.; Fakra, S.; Tyliszczak, T.; Shuh, D.

    2011-12-01

    Carnotite minerals [X2(UO2)2(VO4)2]; X = K, Ca, Ba, Mn, Na, Cu or Pb] form the major ore of uranium in the Colorado Plateau. These deposits are highly oxidized and contain U(VI) and V(IV). The biotransformation of U(VI) bound in carnotite by bacteria during dissimilatory metal reduction presents a complex puzzle in mineral chemistry. Both U(VI) and V(V) can be respired by metal reducing bacteria, and the mineral structure can change depending on the associated counterion. We incubated anaerobic cultures of S. putrefaciens CN32 with natural carnotite minerals from southeastern Utah in a nutrient-limited defined medium. Strain CN32 is a gram negative bacterium and a terrestrial isolate from New Mexico. The mineral and metal transformations were compared to a system that contained similar concentrations of soluble U(VI) and V(V). Electron (SEM, TEM) microscopies and x-ray spectromicroscopy (STXM) were used in conjunction with XRD to track mineral changes, and bacterial survival was monitored throughout the incubations. Slow rates of metal reduction over 10 months for the treatment with carnotite minerals revealed distinct biotic and abiotic processes, providing insight on mineral transformation and bacteria-metal interactions. The bacteria existed as small flocs or individual cells attached to the mineral phase, but did not adsorb soluble U or V, and accumulated very little of the biominerals. Reduction of mineral V(V) necessarily led to a dismantling of the carnotite structure. Bioreduction of V(V) by CN32 contributed small but profound changes to the mineral system, resulting in new minerals. Abiotic cation exchange within the carnotite group minerals induced the rearrangement of the mineral structures, leading to further mineral transformation. In contrast, bacteria survival was poor for treatments with soluble U(VI) and V(V), although both metals were reduced completely and formed solid UO2 and VO2; we also detected V(III). For these treatments, the bacteria

  1. Variable mineral composition of metamorphic rocks from a single quarry compared to their ASR potential (Bohemian Massif, Czech Republic)

    NASA Astrophysics Data System (ADS)

    Stastna, Aneta; Sachlova, Sarka; Pertold, Zdenek; Nekvasilova, Zuzana; Prikryl, Richard

    2013-04-01

    The alkali-silica reaction (ASR) is one of the most damaging factors for concrete structures. ASR originates due to the presence of reactive silica (SiO2) that reacts with alkaline ions under wet conditions. The reaction mechanism consists of four different steps: initial attack of OH- compounds on SiO2 at aggregate-cement paste boundary; formation of silanol groups at SiO2 surface; formation of siloxane groups and their polymerization; adsorption of alkaline and Ca2+ ions and formation of alkali-silica gels. Alkali-silica gels tend to absorb water molecules and swell causing increasing internal pressures in concrete and microcracking. The most reactive aggregates are mainly composed of amorphous and/or fine-grained SiO2-rich phases. In the Czech Republic, ASR was observed in deteriorating concrete structures containing very fine-grained quartz (quartz in tuffaceous sandstones and greywackes), as well as quartz indicating variable degree of deformation (quartz in quartzite, granodiorite and various metamorphic rock types). In this study, mineralogical-petrographic methods (polarizing, electron and cathodoluminescence microscopy) were combined with the accelerated mortar bar test (following the standard ASTM C1260), with the aim to quantify the ASR potential, as well as to distinguish reactive mineral phases. Different aggregate varieties from the Těchobuz quarry (Moldanubian Zone, Czech Republic) have been compared. Mineralogical-petrographic characteristics permit a distinction between 1) medium-grained plagioclase quartzite and 2) fine-grained biotite-plagioclase-quartz paragneiss and 3) fine-grained calc-silicate rock. Mineralogical composition of the first type is quartz + Ca-plagioclase + K-feldspar + biotite + chlorite + diopside + pyrite + apatite + titanite ± calcite. The second type has mineral assemblage including quartz + Ca-plagioclase + K-feldspar + biotite + chlorite + pyrite + tourmaline + apatite + titanite ± calcite. The third type contains

  2. Uranium minerals in Oligocene gypsum near Chadron, Dawes County, Nebraska

    USGS Publications Warehouse

    Dunham, R.J.

    1955-01-01

    Carnotite, sabugalite [HAI(UO2)4(PO4)4 • 16H2O] and autunite occur in the basal 25 feet of a 270-foot sequence of nonmarine bedded gypsum and gypsiferous clay in the Brule formation of Oligocene age about 12 miles northeast of Chadron in northeastern Dawes County, Nebraska. Uranium minerals are visible at only two localities and are associated with carbonaceous matter. Elsewhere the basal 25 feet of the gypsum sequence is interbedded with carbonate rocks and is weakly but persistently uraniferous. Uranium probably was emplaced from above by uranyl solutions rich in sulfate.

  3. Lung cancer mortality among U. S. uranium miners: a reappraisal

    SciTech Connect

    Whittemore, A.S.; McMillan, A.

    1983-09-01

    This report examines lung cancer mortality among a cohort of white underground uranium miners in the Colorado plateau and is based on mortality follow-up through December 31, 1977. The analytic methods represent a miner's annual age-specific lung cancer mortality rate as the (unspecified) rate among nonsmoking men born at the same time and with no mining history, multiplied by the relative risk factor R. This factor depends on the miner's total exposures to radon daughters (in working level months (WLM) and to cigarettes (in packs), accumulated from start of exposure until 10 years before his current age. Among those examined, the relative risk function giving the highest likelihood of the data was R . (1 + 0.31 X 10(-/sup 2/) WLM)(1 + 0.51 X 10(-/sup 3/) packs). This multiplicative function specifies that ratios of mortality rates for miners versus nonminers with similar age and smoking characteristics do not depend on smoking status. By contrast, differences between miners' and nonminers' mortality rates are substantially higher for smokers than for nonsmokers. The data rejected (P . .01) several additive functions for R that specify relative risk as a sum of components due to radiation and to cigarette smoking. Cumulative exposures to both radiation and cigarettes gave better fits to the data than did average annual exposure rates. Age at start of underground mining had no effect on risk, after controlling for age at lung cancer death, year of birth, and cumulative radiation and smoking exposures.

  4. Micronuclei in lymphocytes from currently active uranium miners.

    PubMed

    Zölzer, Friedo; Hon, Zdeněk; Skalická, Zuzana Freitinger; Havránková, Renata; Navrátil, Leoš; Rosina, Jozef; Škopek, Jiří

    2012-08-01

    Micronuclei can be used as markers of past radiation exposure, but only few studies have dealt with uranium miners. In this paper, we report on micronuclei in lymphocytes from individuals currently working at Rožná, Czech Republic, the last functioning uranium mine in the European Union. A modified micronucleus-centromere test was applied to assess the occurrence of micronuclei in stimulated lymphocytes, as well as their content in terms of whole chromosomes or fragments. Compared with unexposed individuals, the miners had higher frequencies of micronucleus-containing lymphocytes and higher percentages of micronuclei without centromeres, and the differences were significant for both parameters (0.74 ± 0.60 vs. 0.50 ± 0.42, p = 0.017 and 49 ± 44 vs. 12 ± 21, p = 0.0002; means ± standard deviations). There were also significant correlations between one or other of these parameters on the one hand and various dose values on the other, in particular with a 'retrievable' dose, that is, a dose whose effect should still be recognisable in lymphocytes assuming a half-life of 3 years. The 'retrievable' dose at which a doubling of the micronucleus frequency was observed was around 35 mSv, corresponding to a total dose of 90 mSv received while working in the mines. Altogether, our data show that the micronucleus-centromere test is a valuable tool for the assessment of past radiation exposure in uranium miners. The scatter in the data is of course far too great to allow individual dosimetry, but for groups of a few dozen exposed individuals, the method can be used to monitor doses clearly below 100 mSv. PMID:22622995

  5. Long-term persistence of chromosome aberrations in uranium miners.

    PubMed

    Mészáros, Gabriella; Bognár, Gabriella; Köteles, G J

    2004-07-01

    Chromosome aberration analyses were performed on blood samples from 165 active underground uranium miners between 1981 and 1985. After decommissioning the mine in 1997 chromosome aberration analyses were also included in the medical laboratory investigations of health conditions of 141 subjects between 1998 and 2002 within the framework of a follow-up-study. The numerical data are presented as functions of the exposure categories expressed in working level month up to 600. In the active groups the dicentric level was 7 to 12 times higher than in the unexposed population, the acentrics also higher with more than an order of magnitude, the frequency of total aberrations--including dicentrics, acentrics, rings, deletions, minits and numerical aberrations, i.e. both chromatid and chromosome type of aberrations were also well above the control level. In the group of former uranium miners although there were slight decreases in the dicentrics after 8 to 25 yr, the values were not significantly different from the values of active miners. The frequency of deletions was also maintained in the post-mining period. The frequency of acentrics, however, decreased significantly, but even the lowest values remained 2-3 times higher than the values in the unexposed population.The possibility is suggested that for the long-term persistence of cytogenetic alterations the permanent production and presence of clastogenic factors might be responsible. The comparison of the two datasets suggest a long-term persistence of cytogenetic alterations above the population average values in a large fraction of persons investigated. PMID:15308832

  6. UraniumVI sorption behavior on silicate mineral mixtures.

    PubMed

    Prikryl, J D; Jain, A; Turner, D R; Pabalan, R T

    2001-02-01

    UraniumVI sorption experiments involving quartz and clinoptilolite, important mineral phases at the proposed US nuclear waste repository at Yucca Mountain, NV, were conducted to evaluate the ability of surface complexation models to predict UVI sorption onto mineral mixtures based on parameters derived from single-mineral experiments. The experiments were conducted at an initial UVI aqueous concentration of approximately 2.0 x 10(-7) mol.l-1 (0.1 mol.l-1 NaNO3 matrix) and over the pH range approximately 2.5 to approximately 9.5. The UVI solutions were reacted with either quartz or clinoptilolite only, or with mixtures of the two minerals. The experiments were carried out under atmospheric pCO2(g) conditions (in loosely capped containers) or under limited pCO2(g) (in capped containers or in a glove box). Data from sorption experiments on quartz at atmospheric pCO2 conditions were used to derive UVI binding constants for a diffuse-layer surface complexation model (DLM). The DLM was then used with surface area as a scaling factor to predict sorption of UVI onto clinoptilolite and clinoptilolite/quartz mixtures under both atmospheric and low pCO2 conditions. The calculations reproduced many aspects of the pH-dependent sorption behavior. If this approach can be demonstrated for natural mineral assemblages, it may be useful as a relatively simple method for improving radionuclide transport models in performance-assessment calculations. PMID:11288580

  7. Uranium mineralization in response to regional metamorphism at Lilljuthatten, Sweden.

    USGS Publications Warehouse

    Stuckless, J.S.; Troeng, B.

    1984-01-01

    Uranium deposits occur in the Olden granite of approx 1650 m.y. in age. This granite outcrops in the northern and eastern segments of the Precambrian Olden window of the central Swedish Caledonides. The Olden granite is a 'highly evolved' biotite granite, with SiO2 >70%. The granite was rich in U (and other incompatible trace elements) and much of the U was located in labile sites. During the Caledonian orogeny 420 m.y. ago, the granite was metamorphosed to greenschist facies, clastically deformed, hydrothermally altered in turn, and mineralized along fractures with quartz, fluorite, calcite and galena. Pitchblende and coffinite were locally deposited as fracture fillings, in particular association with biotitic alteration, whose relation to hydrothermal alteration is obscure; biotite is concentrated along fractures. The U deposits are partly and 'recently' oxidized. The Pb-U, Pb-Pb, and Sr-Rb isotopic systems of most samples were strongly to completely reset by the Caledonian orogeny. The source and host of the Lilljuthatten uranium ore was a special type of granite. The granite fractured, U was mobilized by metamorphism, and deposited in the fractures, and the deposit was preserved from weathering. Similar U deposits in high U granites, common in the Swedish Caledonides, should occur elsewhere.-G.J.N.

  8. Uranium mineralization in fluorine-enriched volcanic rocks

    SciTech Connect

    Burt, D.M.; Sheridan, M.F.; Bikun, J.; Christiansen, E.; Correa, B.; Murphy, B.; Self, S.

    1980-09-01

    Several uranium and other lithophile element deposits are located within or adjacent to small middle to late Cenozoic, fluorine-rich rhyolitic dome complexes. Examples studied include Spor Mountain, Utah (Be-U-F), the Honeycomb Hills, Utah (Be-U), the Wah Wah Mountains, Utah (U-F), and the Black Range-Sierra Cuchillo, New Mexico (Sn-Be-W-F). The formation of these and similar deposits begins with the emplacement of a rhyolitic magma, enriched in lithophile metals and complexing fluorine, that rises to a shallow crustal level, where its roof zone may become further enriched in volatiles and the ore elements. During initial explosive volcanic activity, aprons of lithicrich tuffs are erupted around the vents. These early pyroclastic deposits commonly host the mineralization, due to their initial enrichment in the lithophile elements, their permeability, and the reactivity of their foreign lithic inclusions (particularly carbonate rocks). The pyroclastics are capped and preserved by thick topaz rhyolite domes and flows that can serve as a source of heat and of additional quantities of ore elements. Devitrification, vapor-phase crystallization, or fumarolic alteration may free the ore elements from the glassy matrix and place them in a form readily leached by percolating meteoric waters. Heat from the rhyolitic sheets drives such waters through the system, generally into and up the vents and out through the early tuffs. Secondary alteration zones (K-feldspar, sericite, silica, clays, fluorite, carbonate, and zeolites) and economic mineral concentrations may form in response to this low temperature (less than 200 C) circulation. After cooling, meteoric water continues to migrate through the system, modifying the distribution and concentration of the ore elements (especially uranium).

  9. Identification and occurrence of uranium and vanadium minerals from the Colorado Plateaus

    USGS Publications Warehouse

    Weeks, A.D.; Thompson, M.E.

    1954-01-01

    This report, designed to make available to field geologists and others informa- tion obtained in recent investigations by the Geological Survey on identification and occurrence of uranium minerals of the Colorado Plateaus, contains descriptions of the physical properties, X-ray data, and in some instances results of chemical and spectrographic analysis of 48 uranium and vanadium minerals. Also included is a list of locations of mines from which the minerals have been identified.

  10. Silicosis and lung cancer risk in underground uranium miners

    SciTech Connect

    Samet, J.M.; Pathak, D.R.; Morgan, M.V.

    1994-04-01

    The presence of radiographic silicosis as a risk factor for lung cancer was assessed in a case-control study conducted within a study cohort of New Mexico underground uranium miners. Chest radiographs were interpreted for the presence of silicosis for 65 lung cancer cases and 216 controls. The presence of silicosis on the chest radiograph taken closest to the start of employment or on the latest radiograph available was not associated with lung cancer risk after adjustment for cumulative exposure to radon progeny. The odds ratio associated with the presence of any type of opacity indicative of pneumoconiosis on the chest x ray closest to the start of employment was 1.33 (95% confidence interval, 0.31-5.72). For the most recent available chest x ray, the corresponding odds ratio was 1.16 (95% confidence interval, 0.35-3.84). Although the findings are limited by the relatively small number of subjects, the lack of association of silicosis with lung cancer suggests that silica exposure should not be regarded as a major uncertainty in extrapolating radon risk estimates from miners to the general population. 20 refs., 1 fig., 1 fig.

  11. Early lung cancer detection in uranium miners with abnormal sputum cytology

    SciTech Connect

    Saccomanno, G.

    1992-08-01

    This work supported by the United States of Energy, continues to add data on the health affects of cigarette smoking and radon exposure on uranium miners. Since the last Technical Progress Report in July or 1991, 537 sputum cytology samples have been collected on the 300 uranium workers in the surveillance study. To date there are 436 lung cancer cases in the Uranium Miner Tumor Registry with diagnostic slides from surgery and/or autopsy; an additional 40 cases have been diagnosed with sputum cytology only. In March of 1991 the Geno Saccomanno Uranium Workers Archive was established at St. Mary's Hospital and Medical Center as a depository for biological specimens and epidemiological data from the 17,700 uranium miners who have been a part or the study.

  12. Geochemistry of clay minerals for uranium exploration in the Grants mineral belt, New Mexico

    NASA Astrophysics Data System (ADS)

    Brookins, D. G.

    1982-03-01

    Clay mineralogy studies of ore rocks versus barren rocks in the Grants mineral belt, New Mexico, show that some combination of chlorite (rosette form), illite, mixed-layer illite-montmorillonite, (±Mg-montmorillonite) are penecontemporaneous with uranium minerals in trend ore; these same clay minerals plus kaolinite are related to the roll-type ore near the main redox front of the Grants mineral belt. Clay minerals from barren rocks are characterized by a greater abundance of Na-montmorillonite, kaolinite, and face-to-edge form chlorite. Chlorites from ore zones contain much more vanadium than do chlorites from barren rocks. Trend orr probably formed from southeasterly flowing waters following paleochannels in the Late Jurassic. These deposits are found almost entirely in reduced rocks, and organic carbon may have been an important reductant to remove U-V-U-V-Se-Mo from solution as carbonate from ore zones contains some organic carbon based on stable isotope studies. Uplift, remobilization, and reprecipitation of some of the trend ore resulted in the formation of redistributed ore, some of which possesses a roll-type geometry. Mineralization for the roll-type ore was apparently controlled by sulfide-sulfate equilibria at or near the main redox front in the Grants mineral belt. Trend and roll-type ore possess different assemblages of clay minerals and different trace element abundances. Laramide-age faults cut both trend ore and some roll-type ores. Stack ore is found in Laramide-age fault zones. Limited oxygen isotopic data from clay minerals collected from two mines at Ambrosia Lake in reduced rocks indicate probable preservation of ancient, formational waters and show no evidence of infiltration by young meteoric waters. This information, plus the pre-Laramide-age faults, suggest, but do not unequivocally prove, that the main redox front has been relatively stable since its formation, probably some time in the Cretaceous. Younger encroachment of the redox front

  13. Lung cancer in uranium miners and the implications of the U/V ratio in uranium-bearing particles

    SciTech Connect

    Paschoa, A.S.; Wrenn, M.E.; Singh, N.P.; Bruenger, F.W.; Miller, S.C.; Cholewa, M.; Jones, K.W.

    1985-01-01

    Several geological formations mined for uranium ore during and after the second World War had been mined earlier for vanadium. Most miners and millers from the Utah-Colorado mining region worked with this ore or its tailings at one time or another. Preliminary investigation to determine the size and location of uranium-bearing particles retained in the lungs of a former uranium miner and miller from this region, who died of lung cancer (mesothelioma), showed a high nonuniform distribution of vanadium. This observation leads to the hypothesis that the vanadium content in that lung could be associated with inhaled particles. Further examination of spectra of characteristic x-rays obtained by scanning microPIXE (particle induced x-ray emission) of an autopsy sample of this lung indicated that vanadium was indeed present in localized sites within the 20 ..mu..m spatial resolution of the proton beam. This work points out that the vanadium found in the lungs of this former miner and miller is nonuniformly distributed, and can be used for site localization and size determination of inhaled particles retained in the lungs. The meaning of U/V ratios in dust particles and in lungs is discussed. Further studies are in progress to: (1) locate uranium-bearing particles in lung tissues of former uranium miners and millers; and (2) evaluate the local alpha doses received from these particles. 11 refs., 3 figs., 1 tab.

  14. High resolution remote sensing information identification for characterizing uranium mineralization setting in Namibia

    NASA Astrophysics Data System (ADS)

    Zhang, Jie-Lin; Wang, Jun-hu; Zhou, Mi; Huang, Yan-ju; Xuan, Yan-xiu; Wu, Ding

    2011-11-01

    The modern Earth Observation System (EOS) technology takes important role in the uranium geological exploration, and high resolution remote sensing as one of key parts of EOS is vital to characterize spectral and spatial information of uranium mineralization factors. Utilizing satellite high spatial resolution and hyperspectral remote sensing data (QuickBird, Radarsat2, ASTER), field spectral measurement (ASD data) and geological survey, this paper established the spectral identification characteristics of uranium mineralization factors including six different types of alaskite, lower and upper marble of Rössing formation, dolerite, alkali metasomatism, hematization and chloritization in the central zone of Damara Orogen, Namibia. Moreover, adopted the texture information identification technology, the geographical distribution zones of ore-controlling faults and boundaries between the different strata were delineated. Based on above approaches, the remote sensing geological anomaly information and image interpretation signs of uranium mineralization factors were extracted, the metallogenic conditions were evaluated, and the prospective areas have been predicted.

  15. Experimental study of uranium(6+) sorption of the zeolite mineral clinoptilolite

    SciTech Connect

    Pabalan, R.T.; Prikryl, J.D.; Muller, P.M.; Dietrich, T.B.

    1993-12-31

    Experiments on the sorption of uranium(6+) on clinoptilolite from solutions in equilibrium with atmospheric CO{sub 2}(g) were conducted to understand the fundamental controls on uranium sorption on zeolite minerals, including the effects of pH, aqueous uranium speciation, and uranium concentration in solution. The results indicate that uranium(6+) species are strongly sorbed on the zeolite mineral clinoptilolite at near-neutral pH. The amount of uranium sorbed is strongly dependent on pH and, to some extent, on the total concentration of uranium. Uranium sorption on clinoptilolite is important in the pH range where UO{sub 2}(OH){sub 2}{degrees}(aq) is the predominant uranium aqueous species, whereas sorption is inhibited at pH`s where carbonate- and hydroxy-carbonate-complexes are the primary uranyl species. Surface adsorption appears to be the main sorption mechanism, although at pH<4 the results suggest ion exchange may occur between the UO{sub 2}{sup 2+} ions in solution and the cations in the intracrystalline cation exchange sites of clinoptilolite. The effectiveness of zeolite-rich horizons underneath Yucca Mountain, Nevada, as barriers to actinide transport through sorption processes will depend strongly on groundwater chemistry. Reliable predictions of radionuclide transport through these horizons will need to properly account for changes in solution chemistry.

  16. U-Pb geochronology of the Lagoa Real uranium district, Brazil: Implications for the age of the uranium mineralization

    NASA Astrophysics Data System (ADS)

    Lobato, Lydia Maria; Pimentel, Márcio Martins; Cruz, Simone C. P.; Machado, Nuno; Noce, Carlos Maurício; Alkmim, Fernando Flecha

    2015-03-01

    The Lagoa Real uranium district in Bahia, northeastern Brazil, is the most important uranium province in the country and presently produces this metal in an open-pit mine operated by Indústrias Nucleares do Brasil. Uranium-rich zones are associated with plagioclase (dominantly albite ± oligoclase) -rich rocks, albitites and metasomatized granitic-gneisses, distributed along NNW/SSE striking shear zones. We have used the ID-TIMS U-Pb method to date zircon and titanite grains from the São Timóteo granitoid, and albite-rich rocks from the Lagoa Real district in order to assess the age of granite emplacement, deformation/metamorphism and uranium mineralization. The isotopic data support the following sequence of events (i) 1746 ± 5 Ma - emplacement of the São Timóteo granitoid (U-Pb zircon age) in an extensional setting, coeval with the beginning of the sedimentation of the Espinhaço Supergroup; (ii) 956 ± 59 Ma hydrothermal alteration of the São Timóteo granitoid and emplacement of the uranium mineralization (U-Pb titanite age on an albite-rich sample); (iii) 480 Ma metamorphism, remobilization and Pb loss (U-Pb titanite age for the gneiss sample), during the nucleation of shear zones related to the collision between the São Francisco-Congo and Amazonia paleoplates. The 956 ± 59-Ma mineralization age is apparently associated with the evolution of the Macaúbas-Santo Onofre rift. This age bracket may bear an important exploration implication, and should be included in the diverse age scenario of uranium deposits worldwide.

  17. Uranium co-precipitation with iron oxide minerals

    NASA Astrophysics Data System (ADS)

    Duff, Martine C.; Coughlin, Jessica Urbanik; Hunter, Douglas B.

    2002-10-01

    In oxidizing environments, the toxic and radioactive element uranium (U) is most soluble and mobile in the hexavalent oxidation state. Sorption of U(VI) on Fe-oxides minerals (such as hematite [α-Fe 2O 3] and goethite [α-FeOOH]) and occlusion of U(VI) by Fe-oxide coatings are processes that can retard U transport in environments. In aged U-contaminated geologic materials, the transport and the biological availability of U toward reduction may be limited by coprecipitation with Fe-oxide minerals. These processes also affect the biological availability of U(VI) species toward reduction and precipitation as the less soluble U(IV) species by metal-reducing bacteria. To examine the dynamics of interactions between U(VI) and Fe oxides during crystallization, Fe-oxide phases (containing 0.5 to 5.4 mol% U/(U + Fe)) were synthesized by means of solutions of U(VI) and Fe(III). Wet chemical (digestions and chemical extractions) and spectroscopic techniques were used to characterize the synthesized Fe oxide coprecipitates after rinsing in deionized water. Leaching the high mol% U solids with concentrated carbonate solution (for sorbed and solid-phase U(VI) species) typically removed most of the U, leaving, on average, about 0.6 mol% U. Oxalate leaching of solids with low mol% U contents (about 1 mol% U or less) indicated that almost all of the Fe in these solids was crystalline and that most of the U was associated with these crystalline Fe oxides. X-ray diffraction and Fourier-transform infrared (FT-IR) spectroscopic studies indicate that hematite formation is preferred over that of goethite when the amount of U in the Fe-oxides exceeds 1 mol% U (˜4 wt% U). FT-IR and room temperature continuous wave luminescence spectroscopic studies with unleached U/Fe solids indicate a relationship between the mol% U in the Fe oxide and the intensity or existence of the spectra features that can be assigned to UO 22+ species (such as the IR asymmetric υ 3 stretch for O = U = O for

  18. Depositional environments as a guide to uranium mineralization in the Chinle Formation, San Rafael Swell, Utah

    USGS Publications Warehouse

    Lupe, Robert

    1976-01-01

    Uranium deposits in the San Rafael Swell are related to sedimentary depositional environments in the Triassic Chinle Formation. The sedimentary textures resulting from depositional processes operating in lower energy environments appear to have influenced uranium mineralization. The Chinle consists of three fining-upward, fluvial-lacustrine sequences. Uranium mineralization is concentrated in the lower part of the lowest sequence in areas where sediments of lower energy environments are complexly interbedded with sediments of other environments. Areas favorable for uranium exploration exist in the subsurface to the north, west, and south of the Chinle outcrop in the Swell. This determination is based on the spatial distribution of depositional environments and the pattern of Chinle deposition through time.

  19. Early Lung Cancer Detection in Uranium Miners with Abnormal Sputum Cytology

    SciTech Connect

    Saccomanno, G.

    2000-06-30

    ''Early Lung Cancer Detection in Uranium Miners with Abnormal Sputum Cytology'' was funded by the Department of Energy to monitor the health effects of radon exposure and/or cigarette smoke on uranium workers from the Colorado Plateau. The resulting Saccomanno Uranium Workers Archive and data base has been used as a source of information to prove eligibility for compensation under the Radiation Exposure Compensation Act and as the source of primary data tissue for a subcontract and other collaborations with outside investigators. The latter includes a study of radon exposure and lung cancer risk in a non-smoking cohort of uranium miners (subcontract); a study of genetic markers for lung cancer susceptibility; and a study of {sup 210}Pb accumulation in the skull as a biomarker of radon exposure.

  20. Radium and uranium data for mineral springs in eight Western States

    USGS Publications Warehouse

    Felmlee, J. Karen; Cadigan, Robert Allen

    1978-01-01

    Data for 116 mineral springs in eight Western States show a wide range of values. Specific conductance, temperature, and pH were measured at the sites between 1975 and 1977, and samples for radium and uranium analysis were collected. Correlation and regression analyses among the five measured parameters indicate that a positive correlation exists between radium and specific conductance and that negative correlations exist between radium and pH, specific conductance and pH, and uranium and temperature.

  1. X-ray absorption studies of uranium sorption on mineral substrates

    SciTech Connect

    Hudson, E.A.; Terminello, L.J.; Viani, B.E.

    1994-11-01

    Uranium L{sub 3}-edge x-ray absorption spectra have been measured for uranium-mineral sorption systems. An expansible layer silicate, vermiculite, was treated to obtain a collapsed and non-expanding phase, thereby limiting access to the interior cation exchange sites. Samples were prepared by exposing the finely powdered mineral, in the natural and modified form, to aqueous solutions of uranyl chloride. EXAFS spectra of the encapsulated samples were measured at the Stanford Synchrotron Radiation Laboratory. Results indicate that the uranyl ion possesses a more symmetric local structure within the interlayer regions of vermiculite than on the external surfaces.

  2. Genesis of secondary uranium minerals associated with jasperoid veins, El Erediya area, Eastern Desert, Egypt

    NASA Astrophysics Data System (ADS)

    Abd El-Naby, Hamdy H.

    2008-11-01

    Uranium mineralization in the El Erediya area, Egyptian Eastern Desert, has been affected by both high temperature and low temperature fluids. Mineralization is structurally controlled and is associated with jasperoid veins that are hosted by a granitic pluton. This granite exhibits extensive alteration, including silicification, argillization, sericitization, chloritization, carbonatization, and hematization. The primary uranium mineral is pitchblende, whereas uranpyrochlore, uranophane, kasolite, and an unidentified hydrated uranium niobate mineral are the most abundant secondary uranium minerals. Uranpyrochlore and the unidentified hydrated uranium niobate mineral are interpreted as alteration products of petscheckite. The chemical formula of the uranpyrochlore based upon the Electron Probe Micro Analyzer (EPMA) is A {left( {{text{U}}_{{1.07}} {text{Ca}}_{{0.28}} {text{Pb}}_{{0.03}} {text{Na}}_{{0.21}} {text{Mg}}_{{0.02}} } right)}_{{Σ 1.6}} B {left( {{text{Nb}}_{{0.57}} {text{Si}}_{{0.62}} {text{Zr}}_{{0.35}} {text{P}}_{{0.20}} {text{Fe}}_{{0.17}} {text{Al}}_{{0.06}} {text{Ti}}_{{0.03}} } right)}_{{Σ 2}} . It is characterized by a relatively high Zr content (average ZrO2 = 6.6 wt%). The average composition of the unidentified hydrated uranium niobate mineral is ^{{text{U}}} {left( {{text{U}}_{{1.89}} {text{Ca}}_{{0.49}} {text{Pb}}_{{0.13}} {text{Na}}_{{0.06}} {text{Mg}}_{{0.02}} } right)}_{{Σ 2.59}} ^{{{text{Nb}}}} {left( {{text{Nb}}_{{1.31}} {text{Fe}}_{{0.34}} {text{Si}}_{{0.14}} {text{P}}_{{0.10}} {text{Ti}}_{{0.05}} {text{Zr}}_{{0.03}} {text{Al}}_{{0.03}} } right)}_{{Σ 2.0}} , where U and Nb represent the dominant cations in the U and Nb site, respectively. Uranophane is the dominant U6+ silicate phase in oxidized zones of the jasperoid veins. Kasolite is less abundant than uranophane and contains major U, Pb, and Si but only minor Ca, Fe, P, and Zr. A two-stage metallogenetic model is proposed for the alteration processes and uranium mineralization at

  3. Lung cancer in uranium miners: A tissue resource and pilot study. Final performance report

    SciTech Connect

    Samet, J.; Gilliland, F.D.

    1998-08-13

    This project incorporates two related research projects directed toward understanding respiratory carcinogenesis in radon-exposed former uranium miners. The first project involved a continuation of the tissue resource of lung cancer cases from former underground uranium miners and comparison cases from non-miners. The second project was a pilot study for a proposed longitudinal study of respiratory carcinogenesis in former uranium miners. The objectives including facilitating the investigation of molecular changes in radon exposed lung cancer cases, developing methods for prospectively studying clinical, cytologic, cytogenetic, and molecular changes in the multi-event process of respiratory carcinogenesis, and assessing the feasibility of recruiting former uranium miners into a longitudinal study that collected multiple biological specimens. A pilot study was conducted to determine whether blood collection, induced sputum, bronchial brushing, washings, and mucosal biopsies from participants at two of the hospitals could be included efficiently. A questionnaire was developed for the extended study and all protocols for specimen collection and tissue handling were completed. Resource utilization is in progress at ITRI and the methods have been developed to study molecular and cellular changes in exfoliated cells contained in sputum as well as susceptibility factors.

  4. Multisource data set integration and characterization of uranium mineralization for the Montrose Quadrangle, Colorado

    SciTech Connect

    Bolivar, S.L.; Balog, S.H.; Campbell, K.; Fugelso, L.E.; Weaver, T.A.; Wecksung, G.W.

    1981-04-01

    Several data-classification schemes were developed by the Los Alamos National Laboratory to detect potential uranium mineralization in the Montrose 1/sup 0/ x 2/sup 0/ quadrangle, Colorado. A first step was to develop and refine the techniques necessary to digitize, integrate, and register various large geological, geochemical, and geophysical data sets, including Landsat 2 imagery, for the Montrose quadrangle, Colorado, using a grid resolution of 1 km. All data sets for the Montrose quadrangle were registered to the Universal Transverse Mercator projection. The data sets include hydrogeochemical and stream sediment analyses for 23 elements, uranium-to-thorium ratios, airborne geophysical survey data, the locations of 90 uranium occurrences, a geologic map and Landsat 2 (bands 4 through 7) imagery. Geochemical samples were collected from 3965 locations in the 19 200 km/sup 2/ quadrangle; aerial data were collected on flight lines flown with 3 to 5 km spacings. These data sets were smoothed by universal kriging and interpolated to a 179 x 119 rectangular grid. A mylar transparency of the geologic map was prepared and digitized. Locations for the known uranium occurrences were also digitized. The Landsat 2 imagery was digitally manipulated and rubber-sheet transformed to quadrangle boundaries and bands 4 through 7 were resampled to both a 1-km and 100-m resolution. All possible combinations of three, for all data sets, were examined for general geologic correlations by utilizing a color microfilm output. Subsets of data were further examined for selected test areas. Two classification schemes for uranium mineralization, based on selected test areas in both the Cochetopa and Marshall Pass uranium districts, are presented. Areas favorable for uranium mineralization, based on these schemes, were identified and are discussed.

  5. Appraisal of selected epidemiologic issues from studies of lung cancer among uranium and hard rock miners

    SciTech Connect

    Petersen, G R; Sever, L E

    1982-04-01

    An extensive body of published information about lung cancer among uranium miners was reviewed and diverse information, useful in identifying important issues but not in resolving them was found. Measuring exposure and response; thresholds of exposure; latency or the period from first mining experience to death; effort to predict excess risk of death, using a model; effects of smoking and radon daughter exposure on the histology of lung tumors; and the interplay of factors on the overall risk of death were all examined. The general concept of thresholds; that is, an exposure level below which risk does not increase was considered. The conclusion is that it should be possible to detect and estimate an epidemiologic threshold when the cohorts have been followed to the death of all members. Issues concerning latency in the studies of uranium miners published to date were examined. It is believed that the induction-latent period for lung cancer among uranium miners may be: as little as 10 to more than 40 years; dependent on age at which exposure begins; exposure rate; and ethnicity or smoking habits. Although suggested as factual, their existence is uncertain. An effect due to the exposure rate may exist although it has not been factual, their existence is uncertain. An effect due to the exposure rate may exist although it has not been confirmed. The median induction-latent period appears to be in excess of the 15 years frequently cited for US uranium miner. A distinct pattern of shorter induction-latent periods with increasing age at first mining exposure is reported. The evidence for and against an unusual histologic pattern of lung cancers among uranium miners was examined. The ratio of epidermoid to small cell types was close to 1:2; the ratio in the general population is nearer 2:1. The histologic pattern warrants closer attention of pathologists and epidemiologists. (ERB) (ERB)

  6. Lung cancer epidemiology in New Mexico uranium miners. Progress report, March 1, 1991--November 30, 1991

    SciTech Connect

    Samet, J.M.

    1991-11-01

    This investigation assesses the health effects of radon progeny exposure in New Mexico uranium miners. Cumulative exposures sustained by most New Mexico miners are well below those received earlier in the Colorado Plateau. This project utilizes the research opportunity offered by New Mexico miners to address unresolved issues related to radon progeny exposure: (1) the lung cancer risk of lower levels of exposure, (2) interaction between radon progeny exposure and cigarette smoking in the causation of lung cancer, (3) the relationship between lung cancer histologic type and radon progeny exposure, and (4) possible effects of radon progeny exposure other than lung cancer. A cohort study of 3800 men with at least one year of underground uranium mining experience in New Mexico is in progress. Results are discussed.

  7. Magnetic Titanohematite Minerals in Uranium-Bearing Sandstones

    USGS Publications Warehouse

    Reynolds, Richard L.

    1977-01-01

    Detrital grains of the rhombohedral ilmenite (FeT1O3)--hematite (Fe2O3) solid solution series (titanohematites) have been identified by thermomagnetic, reflection microscopic, and X-ray diffraction analysis in six uranium-bearing sandstones in the western United States. Many of the titanohematites are ferrimagnetic and have Curie temperatures ranging from about 70 Deg C to 220 Deg C. Magnetic titanohematite is commonly more abundant than magnetite in many samples and, therefore, should be considered as a major source of the permanent magnetization in these units.

  8. Uranium, geoinformatics, and the economic image of mineral exploration.

    PubMed

    Schilling, Tom

    2013-09-01

    When uranium prospectors working in northern Canada want to visualize a new deposit, they can't simply walk outside and take a picture of the ground beneath their feet. 'Mapping' an ore body in the twenty-first century means building a statistical model from a grid of chemical data, a collaborative process demanding the efforts of drilling crews, geologists, chemists, and statisticians. As rock samples are translated into numerical concentration values and then back into images of geological features, scientific theories become economic data, reshaping geological theory, environmental regulation and development in the process. PMID:23830622

  9. In vivo measurements of lead-210 for assessing cumulative radon exposure in uranium miners

    SciTech Connect

    Guilmette, R.A.; Laurer, G.R.; Lambert, W.E.; Gilliland, F.D.

    1995-12-01

    It has long been recognized that a major contributor to the uncertainty in risk analysis of lung cancer in uranium and other hard rock miners is the estimation of total radon progeny exposure of individual miners under study. These uncertainties arise from the fact that only a limited number of measurements of airborne {sup 222}Rn progeny concentrations were made in the mines during the times that the miners were being exposed, and that dosimeters capable of integrating the Rn progeny exposures of the miners did not exist. Historically, the cumulative exposures for individual uranium and other hard rock miners have been calculated by combining the employee`s work history, which may or may not have included time spent at different jobs within the mines and at different locations within the mines, with whatever periodic measurements of Rn and Rn progeny were available. The amount and quality of the measurement data varied enormously from mine to mine and from population to population. Because the quality of the exposure data collected during the period of active mining in the United STates cannot now be altered substantially, significant improvement in individual miner exposure estimates is only likely to be achieved if a new cumulative exposure metric is developed and implemented. The decay chain of Rn includes the production of {sup 210}Pb, which can accumulate in the skeleton in amounts proportional to the intake of Rn progeny. We hypothesize that the in vivo measurement of {sup 210}Pb in the skulls of miners will provide such a metric. In summary, the primary purpose of this pilot study to demonstrate the feasibility of measuring {sup 210}Pb in the heads of former uranium miners has been accomplished.

  10. Detailed mineral and chemical relations in two uranium-vanadium ores

    USGS Publications Warehouse

    Garrels, Robert M.; Larsen, E. S., III; Pommer, A.M.; Coleman, R.G.

    1956-01-01

    Channel samples from two mines on the Colorado Plateau have been studied in detail both mineralogically and chemically. A channel sample from the Mineral Joe No. 1 mine, Montrose County, Colo., extends from unmineralized rock on one side, through a zone of variable mineralization, into only weakly mineralized rock. The unmineralized rock is a fairly clean quartz sand cemented with gypsum and contains only minor amounts of clay minerals. One boundary between unmineralized and mineralized rock is quite sharo and is nearly at right angles to the bedding. Vanadium clay minerals, chiefly mixed layered mica-montmorillonite and chlorite-monmorillonite, are abundant throughout the mineralized zone. Except in the dark "eye" of the channel sample, the vanadium clay minerals are accompanied by hewettite, carnotite, tyuyamunite, and probably unidentified vanadates. In the dark "eye," paramontroseite, pyrite, and marcasite are abundant, and bordered on each side by a zone containing abundant corvusite. No recognizable uranium minerals were seen in the paramontroseite zone although uranium is abundant there. Coaly material is recognizable throughout all of the channel but is most abundant in and near the dark "eye." Detailed chemical studies show a general increase in Fe, Al, U, and V, and a decrease in SO4 toward the "eye" of the channel. Reducing capacity studies indicate that V(IV) and Fe(II) are present in the clay mineral throughout the channel, but only in and near the "eye" are other V(IV) minerals present (paramontroseite and corvusite). The uranium is sexivalent, although its state of combination is conjectural where it is associated with paramontroseite. Where the ore boundary is sharp, the boundary of introduced trace elements is equally sharp. Textural and chemical relations leave no doubt that the "eye: is a partially oxidized remnant of a former lower-valence ore, and the remainder of the channel is a much more fully oxidized remnant. A channel sample from the

  11. Uranium and thorium sorption on minerals studied by x-ray absorption spectroscopy

    SciTech Connect

    Hudson, E.A.; Terminello, L.J.; Viani, B.E.

    1995-12-01

    Several actinide-mineral sorption systems were studied by uranium and thorium L{sub 3}-edge x-ray absorption spectroscopy. A series of layer silicate minerals, including micas, were selected for their systematic variations in surface structure, e.g. degree of permanent negative charge on the basal planes. An expansible layer silicate, vermiculite, was treated to provide several different interlayer spacings, allowing variations in the accessibility of interior cation exchange sites. The finely powdered minerals were exposed to aqueous solutions of uranyl chloride or thorium chloride. Analysis of the EXAFS and XANES spectra indicates the influence of the mineral substrate upon the local structure of the bound actinide species. Trends in the data are interpreted based upon the known variations in mineral structure.

  12. Unexpected rates of chromosomal instabilities and alterations of hormone levels in Namibian uranium miners.

    PubMed

    Zaire, R; Notter, M; Riedel, W; Thiel, E

    1997-05-01

    A common problem in determining the health consequences of radiation exposure is factoring out other carcinogenic influences. The conditions in Namibia provide a test case for distinguishing the effects of long-term low-dose exposure to uranium from the other environmental factors because of good air quality and the lack of other industries with negative health effects. Present records indicate a much higher prevalence of cancer among male workers in the open-pit uranium mine in Namibia compared with the general population. The objective of the present study was to determine whether long-term exposure to low doses of uranium increases the risk of a biological radiation damage which would lead to malignant diseases and to derive a dose-response model for these miners. To investigate this risk, we measured uranium excretion in urine, neutrophil counts and the serum level of FSH, LH and testosterone and analyzed chromosome aberrations in whole blood cells using fluorescence in situ hybridization. A representative cohort of 75 non-smoking, HIV-negative miners was compared to a control group of 31 individuals with no occupational history in mining. A sixfold increase in uranium excretion among the miners compared to the controls was recorded (P < 0.001). Furthermore, we determined a significant reduction in testosterone levels (P < 0.008) and neutrophil count (P < 0.004) in miners compared to the unexposed controls. A threefold increase in chromosome aberrations in the miners compared to the nonexposed controls was recorded (P < 0.0001). Most remarkably, cells with multiple aberrations such as "rogue" cells were observed for the first time in miners; these cells had previously been found only after short-term high-dose radiation exposure, e.g. from the Hiroshima atomic bomb or the Chernobyl accident. We conclude that the miners exposed to uranium are at an increased risk to acquire various degrees of genetic damage, and that the damage may be associated with an

  13. Large uraniferous springs and associated uranium minerals, Shirley Mountains, Carbon County, Wyoming -- A preliminary report

    USGS Publications Warehouse

    Love, J.D.

    1963-01-01

    Ten springs along the southeast flank of the Shirley Mountains, Carbon County, Wyoming, have water containing from 12 to 27 parts per billion uranium, have a total estimated flow of 3 million gallons of clear fresh water per day, and have a combined annual output that may be as much as 166 pounds of uranium. These springs emerge from Pennsylvanian, Permian, and Triassic rocks on the east flank of a faulted anticlinal fold. In the vicinity of several springs, metatyuyamunite occurs locally in crystalline calcite veins averaging 3 feet in width but reaching a maximum of 24 feet. The veins are as much as several hundred feet long-and cut vertically through sandstones of Pennsylvanian age overlying the Madison Limestone (Mississippian). This limestone is believed to be the source of the calcite. A 3-foot channel sample cross one calcite vein contains 0.089 percent uranium. Lesser amounts of uranium were obtained from other channel samples. Selected samples contain from 0.39 to 2.2 percent uranium and from 0.25 to 0.86 percent vanadium. Three possible sources of the uranium are: (1) Precambrian rocks, (2) Paleozoic rocks, (3) Pliocene(?) tuffaceous strata that were deposited unconformably across older .rocks in both the graphically high and low parts of the area, but were subsequently removed by erosion except for a few small remnants, one of which contains carnotite. There is apparently a close genetic relation between the uraniferous springs and uranium mineralization in the calcite veins. Data from this locality illustrate how uraniferous ground water can be used as a guide in the exploration for areas where uranium deposits may occur. Also demonstrated is the fact that significant quantities of uranium are present in water of some large flowing springs.

  14. Geologic controls of uranium mineralization in the Tallahassee Creek uranium district, Fremont County, Colorado.

    USGS Publications Warehouse

    Dickinson, K.A.

    1981-01-01

    Two important orebodies have been defined by drilling in the Tallahassee Creek uranium district, Fremont County, Colorado, namely the Hansen and the Picnic Tree. Host rocks are respectively the upper Eocene Echo park Alluvium, and the lower Oligocene Tallahassee Creek Conglomerate. Average ore grade is about 0.08% U3O8. The principal source rock is the lower Oligocene Wall Mountain Tuff. Leaching and transportation of the uranium occurred in alkaline oxidizing ground water that developed during alteration of the ash in a semi-arid environment. The uranium was transported in the groundwater and deposited in a reducing environment controlled by carbonaceous material and associated pyrite. Localization of the ore was controlled by groundwater flow conditions and by the distribution of organic matter in the host rock. -from Author

  15. Geologic controls of uranium mineralization in the Tallahassee Creek uranium district, Fremont County, Colorado

    SciTech Connect

    Dickinson, K.A.

    1981-10-01

    Two important orebodies have been defined by drilling in the Tallahassee Creek uranium district, Fremont County, Colorado. They are the Hansen orebody, which contains about 12 million kg of U/sub 3/O/sub 8/, and the Picnic Tree orebody, which contains about 1 million kg of U/sub 3/O/sub 8/. Host rock for the Hansen is the upper Eocene Echo Park Alluvium, and host rock for the Picnic Tree is the lower Oligocene Tallahassee Creek onglomerate. Average ore grade for both deposits is about 0.08 percent U/sub 3/O/sub 8/. The principal source rock for the uranium depsoits is the lower Oligocene Wall Mountain Tuff, although a younger volcanic rock, the Oligocene Thirtynine Mile Andesite, and Precambrian granitic rocks probably also contributed some uranium. Leaching and transportation of the uranium occurred in alkaline oxidizing ground water that developed during alteration of the ash in a semi-arid environment. The uranium was transported in the ground water to favorable sites where it was deposited in a reducing environment controlled by carbonaceous material and associated pyrite. Localization of the ore was controlled by ground-water flow conditions and by the distribution of organic matter in the host rock. Ground-water flow, which was apparently to the southeast in Echo Park Alluvium that is confined in the Echo Park graben, was impeded by a fault that offsets the southern end of the graben. This offset prevented efficient discharge into the ancestral Arkansas River drainage, and protected chemically reducing areas from destruction by the influx of large amounts of oxidizing ground water. The location of orebodies in the Echo Park Alluvium also may be related to areas where overlying rocks of low permeability were breached by erosion during deposition of the fluvial Tallahassee Creek Conglomerate allowing localized entry of uranium-bearing water.

  16. Uranium*

    NASA Astrophysics Data System (ADS)

    Grenthe, Ingmar; Drożdżyński, Janusz; Fujino, Takeo; Buck, Edgar C.; Albrecht-Schmitt, Thomas E.; Wolf, Stephen F.

    Uranium compounds have been used as colorants since Roman times (Caley, 1948). Uranium was discovered as a chemical element in a pitchblende specimen by Martin Heinrich Klaproth, who published the results of his work in 1789. Pitchblende is an impure uranium oxide, consisting partly of the most reduced oxide uraninite (UO2) and partly of U3O8. Earlier mineralogists had considered this mineral to be a complex oxide of iron and tungsten or of iron and zinc, but Klaproth showed by dissolving it partially in strong acid that the solutions yielded precipitates that were different from those of known elements. Therefore he concluded that it contained a new element (Mellor, 1932); he named it after the planet Uranus, which had been discovered in 1781 by William Herschel, who named it after the ancient Greek deity of the Heavens.

  17. Lung cancer in uranium miners: A tissue resource and pilot study. Progress report, September 25, 1992--May 31, 1993

    SciTech Connect

    Samet, J.M.

    1993-05-01

    This project involves two related activities directed toward understanding respiratory carcinogenesis in radon-exposed former uranium miners. The first activity involves a continuation of the tissue resource of lung cancer cases from former underground uranium miners and comparison cases from non-miners. The second activity is a pilot study for a proposed longitudinal study of respiratory carcinogenesis in former uranium miners. The objectives are to facilitate the investigation of molecular changes in radon exposed lung cancer cases and to develop methods for prospectively studying clinical, cytologic, cytogenetic, and molecular changes in the multi-event process of respiratory carcinogenesis, and to assess the feasibility of recruiting former uranium miners into a longitudinal study that collects multiple biologic specimens.

  18. Unexpected rates of chromosomal instabilities and alterations of hormone levels in Namibian uranium miners

    SciTech Connect

    Zaire, R.; Notter, M.; Thiel, E.

    1997-05-01

    A common problem in determining the health consequences of radiation exposure is factoring out other carcinogenic influences. The conditions in Namibia provide a test case for distinguishing the effects of long-term low-dose exposure to uranium from the other environmental factors because of good air quality and the lack of other industries with negative health effects. Present records indicate a much higher prevalence of cancer among male workers in the open-pit uranium mine in Namibia compared with the general population. The objective of the present study was to determine whether long-term exposure to low doses of uranium increases the risk of a biological radiation damage which would lead to malignant diseases and to derive a dose-response model for these miners. To investigate this risk, we measured uranium excretion in urine, neutrophil counts and the serum level of FSH, LH and testosterone and analyzed chromosome aberrations in whole blood cells using fluorescence in situ hybridization. A representative cohort of 75 non-smoking, HIV-negative miners was compared to a control group of 31 individuals with no occupational history in mining. A sixfold increase in uranium excretion among the miners compared to the controls was recorded (P < 0.001). Furthermore, we determined a significant reduction in testosterone levels (P < 0.008) and neutrophil count (P < 0.0001). Most remarkably, cells with multiple aberrations such as {open_quotes}rogue{close_quotes} cells were observed for the first time in miners; these cells had previously been found only after short-term high-dose radiation exposure, e.g. from the Hiroshima atomic bomb or the Chernobyl accident. 19 refs., 1 fig., 3 tabs.

  19. Early lung cancer detection in uranium miners with abnormal sputum cytology

    SciTech Connect

    Saccomanno, G.

    1991-07-01

    This work, supported by the United States Department of Energy, continues to add data on the health effects of cigarette smoking and radon exposure. Since the beginning of this contract, 473 sputum samples have been collected from 286 uranium workers who are routinely screened in an effort to identify cell changes that could signal possible progression to lung cancer; seven new lung cancer cases have been identified during this period. At this time, there are 426 lung cancer cases in the uranium miner tumor registry with diagnostic slides from surgery and/or autopsy; an additional 40 cases have been diagnosed with sputum cytology only.

  20. Ethnic differences in the prevalence of nonmalignant respiratory disease among uranium miners.

    PubMed Central

    Mapel, D W; Coultas, D B; James, D S; Hunt, W C; Stidley, C A; Gilliland, F D

    1997-01-01

    OBJECTIVES: This study (1) investigates the relationship of nonmalignant respiratory disease to underground uranium mining and to cigarette smoking in Native American, Hispanic, and non-Hispanic White miners in the Southwest and (2) evaluates the criteria for compensation of ethnic minorities. METHODS: Risk for mining-related lung disease was analyzed by stratified analysis, multiple linear regression, and logistic regression with data on 1359 miners. RESULTS: Uranium mining is more strongly associated with obstructive lung disease and radiographic pnuemoconiosis in Native Americans than in Hispanics and non-Hispanic Whites. Obstructive lung disease in Hispanic and non-Hispanic White miners is mostly related to cigarette smoking. Current compensation criteria excluded 24% of Native Americans who, by ethnic-specific standards, had restrictive lung disease and 4.8% who had obstructive lung disease. Native Americans have the highest prevalence of radiographic pneumoconiosis, but are less likely to meet spirometry criteria for compensation. CONCLUSIONS: Native American miners have more nonmalignant respiratory disease from underground uranium mining, and less disease from smoking, than the other groups, but are less likely to receive compensation for mining-related disease. PMID:9184515

  1. Application of solution-mineral equilibrium chemistry to solution mining of uranium ores

    SciTech Connect

    Riese, A.C.; Propp, C.J.

    1980-01-01

    Modern methods of uranium solution mining are typically accompanied by gains and losses of mass through reagent consumption by rock-forming minerals, with subsequent formation of clay minerals, gypsum, carbonates, and iron oxyhydroxides. A systematic approach to alleviate such problems involves the application of leach solutions that are in equilibrium with the host-rock minerals but in disequilibrium with the ore-forming minerals. This partial equilibrium can be approximated by solution-composition adjustments within the systems K/sub 2/O-Al/sub 2/O/sub 3/SiO/sub 2/-H/sub 2/O and Na/sub 2/O/sub 3/-Al/sub 2/O/sub 3/SiO/sub 2/-H/sub 2/O. Uranium ore containing 0.15 percent U/sub 3/O/sub 8/ from the Gulf Mineral Resources Corporation's Mariano Lake mine, the Smith Lake district of the Grants mineral belt, was collected for investigation. Presented are a theoretical evaluation of leachate data and an experimental treatment of the ore, which contained mainly K-feldspar, plagioclase feldspar, and quartz (with lesser amounts of micas, clay minerals, and organic carbonaceous material). Small-scale (less than or equal to 1 kg) column-leaching experiments were conducted to model the results of conventional leaching operations and to provide leachate solutions that could be compared with solutions calculated to be in equilibrium with the matrix minerals. Leach solutions employed include: 1) sulfuric acid, 2) sodium bicarbonate, and 3) sulfuric acid with 1.0 molal potassium chloride. The uranium concentrations in the sodium-bicarbonate leach solution and the acid-leach solution were about a gram per liter at the termination of the tests. However, the permeability of the ore in the acid leach was greatly reduced, owing to the formation of clay minerals. Uranium solubility in the leach column stabilized with the potassium-chloride solution was calculated from leachate compositions to be limited by the solubility of carnotite.

  2. Uranium (VI) sorption onto selected mineral surfaces: Key geochemical parameters

    SciTech Connect

    Pabalan, R.T.; Bertetti, F.P.; Prikryl, J.D.; Turner, D.R.

    1996-10-01

    Batch U(VI) sorption experiments were conducted using quartz, montmorillonite, clinoptilolite, and {alpha}-alumina to determine the key geochemical parameters that influence sorption onto mineral surfaces. The experiments were done at different initial U concentration, pH, M/V, and ionic strength, and at ambient and elevated PCO{sub 2} (10{sup -3.5} and 10{sup -2.0} atm, respectively). The results show that U(VI) sorption on all the minerals studied reaches a maximum at near-neutral pH ({approximately}6.3-6.8) and decreases sharply towards more acidic or alkaline conditions. The pH range where U sorption occurs corresponds to the predominance field of aqueous monomeric U(VI)-hydroxy complexes. Sorption is inhibited at high pH and PCO{sub 2} due to formation of aqueous U(VI)-carbonate complexes. For montmorillonite and clinoptilolite, ion-exchange was suppressed due to the relatively high ionic strength of the solutions. Surface charge properties of the sorbent are inferred to be relatively unimportant factors in U(VI) sorption. Sorption data plotted in terms of K{sub d} show that M/V ratio has little influence on the distribution of U(VI) between the solid and aqueous phases. Modeling of the sorption behavior of U(VI) was performed using a surface complexation approach (Diffuse-Layer Model).

  3. Early lung cancer detection in uranium miners with abnormal sputum cytology. Technical progress report, July 31, 1991--July 31, 1992

    SciTech Connect

    Saccomanno, G.

    1992-08-01

    This work supported by the United States of Energy, continues to add data on the health affects of cigarette smoking and radon exposure on uranium miners. Since the last Technical Progress Report in July or 1991, 537 sputum cytology samples have been collected on the 300 uranium workers in the surveillance study. To date there are 436 lung cancer cases in the Uranium Miner Tumor Registry with diagnostic slides from surgery and/or autopsy; an additional 40 cases have been diagnosed with sputum cytology only. In March of 1991 the Geno Saccomanno Uranium Workers Archive was established at St. Mary`s Hospital and Medical Center as a depository for biological specimens and epidemiological data from the 17,700 uranium miners who have been a part or the study.

  4. Geophysical Investigations of the Uranium Mineralized Formation in the Coaly Black Shale Deposits in Korea

    NASA Astrophysics Data System (ADS)

    Kim, C.; Son, J.; Yoon, H.; Park, S.

    2011-12-01

    Geophysical investigations using electrical resistivity, Spectral Induced Polarization (SIP) methods, and laboratory measurements of the rock physical properties were conducted for uranium exploration in the Okchoen Metamorphic Belt in Korea. The geology of the study site consists of age-unknown slate formations such as coaly black and dark gray slates, limestone interbedded in the slates, and intrusion of cretaceous quartz porphyry of the acidic dikes. The slate formations shows the strike of N40~60E and dip 50~60 toward northwest direction in the site. It has been reported that the low grade concentration of uranium minerals were found in the coaly black slate formations in the site. The main objective of the study is to investigate the geological structures of the slate formations including uranium-bearing black slates. The resistivity of the dark gray slate was measured to be 1,800-10,000 Ohm-M, while that of the coaly black slate to be 17-200 Ohm-M. The conceptual geophysical model of the uranium-bearing black coal slates was constructed for geologic structure of the site, consisting of very high-angled formation with low resistivity and with high IP response due to the presences of coal and pyrite components. On the contrary, the dark gray slates show the geophysical properties of relatively high resistivity, and low IP response due to the absence of sulfide minerals. The results of the geophysical surveys showed high IP response was detected in the coal-bearing slate formation due to sulfide minerals such as pyrite. In addition, the low resistivity anomalies with very high angles were also detected due to coal component in the black slates on both numerical resistivity modeling using conceptual model and on the field resistivity data. The results of the geophysical investigation are in good agreement with the geological and geochemical study results, and were employed for drilling investigations in the site. In order to probe the uranium-bearing formation

  5. Radon exposure, cigarette smoking, and other mining experience in the beaverlodge uranium miners cohort

    SciTech Connect

    L'Abbe, K.A.; Howe, G.R.; Burch, J.D.; Miller, A.B.; Abbatt, J.; Band, P.; Choi, W.; Du, J.; Feather, J.; Gallagher, R. )

    1991-04-01

    A nested case-control study within the Beaverlodge Uranium Miners Cohort was undertaken to assess any possible contribution of confounding by smoking and other mining experience to the risk estimate derived from the original cohort study. Next of kin have been interviewed for 46 lung cancer cases and 95 controls enrolled in the Beaverlodge Uranium Miners Cohort Study who died between 1950 and 1980. Confounding by cigarette smoking and other mining experience appears unlikely to have contributed to the relative risk coefficient for exposure to Rn decay products derived in the parent study. Data for smoking and exposure to Rn decay products are consistent with a multiplicative model, although considerable caution must be applied to this interpretation.

  6. Interpretation of aircraft multispectral scanner images for mapping of alteration with uranium mineralization, Copper Mountain, Wyoming

    NASA Technical Reports Server (NTRS)

    Conel, J. E.

    1983-01-01

    NS-001 multispectral scanner data (0.45-2.35 micron) combined as principal components were utilized to map distributions of surface oxidation/weathering in Precambrian granitic rocks at Copper Mountain, Wyoming. Intense oxidation is found over granitic outcrops in partly exhumed pediments along the southern margin of the Owl Creek uplift, and along paleodrainages higher in the range. Supergene(?) uranium mineralization in the granites is localized beneath remnant Tertiary sediments covering portions of the pediments. The patterns of mineralization and oxidation are in agreement, but the genetic connections between the two remain in doubt.

  7. Mineral transformation and biomass accumulation associated with uranium bioremediation at Rifle, Colorado

    SciTech Connect

    Li, L.; Steefel, C.I.; Williams, K.H.; Wilkins, M.J.; Hubbard, S.S.

    2009-04-20

    Injection of organic carbon into the subsurface as an electron donor for bioremediation of redox-sensitive contaminants like uranium often leads to mineral transformation and biomass accumulation, both of which can alter the flow field and potentially bioremediation efficacy. This work combines reactive transport modeling with a column experiment and field measurements to understand the biogeochemical processes and to quantify the biomass and mineral transformation/accumulation during a bioremediation experiment at a uranium contaminated site near Rifle, Colorado. We use the reactive transport model CrunchFlow to explicitly simulate microbial community dynamics of iron and sulfate reducers, and their impacts on reaction rates. The column experiment shows clear evidence of mineral precipitation, primarily in the form of calcite and iron monosulfide. At the field scale, reactive transport simulations suggest that the biogeochemical reactions occur mostly close to the injection wells where acetate concentrations are highest, with mineral precipitate and biomass accumulation reaching as high as 1.5% of the pore space. This work shows that reactive transport modeling coupled with field data can be an effective tool for quantitative estimation of mineral transformation and biomass accumulation, thus improving the design of bioremediation strategies.

  8. Uranium-bearing minerals of lunar rock 12013.

    NASA Technical Reports Server (NTRS)

    Haines, E. L.; Albee, A. L.; Chodos, A. A.; Wasserburg, G. J.

    1971-01-01

    The U distribution in rock 12013 was studied by fission track and elemental mapping techniques. Major U-bearing phases are whitlockite, apatite, zircon, and phase beta, which is a Zr-Ti mineral rich in Fe, Nb, Y, REE, and containing up to 3.6% UO2, 4.7% ThO2 and 4.2% PbO. Calculated microprobe ages for phase beta average 4.0 b.y. and are in reasonable agreement with Rb-Sr and K-Ar ages. Phase beta plays a significant role in the U-Th-Pb systematics of rock 12012 and may play a similar role in the model ages of lunar soil.

  9. Radon Exposure, IL-6 Promoter Variants, and Lung Squamous Cell Carcinoma in Former Uranium Miners

    PubMed Central

    Leng, Shuguang; Thomas, Cynthia L.; Snider, Amanda M.; Picchi, Maria A.; Chen, Wenshu; Willis, Derall G.; Carr, Teara G.; Krzeminski, Jacek; Desai, Dhimant; Shantu, Amin; Lin, Yong; Jacobson, Marty R.; Belinsky, Steven A.

    2015-01-01

    Background: High radon exposure is a risk factor for squamous cell carcinoma, a major lung cancer histology observed in former uranium miners. Radon exposure can cause oxidative stress, leading to pulmonary inflammation. Interleukin-6 (IL-6) is a pro-carcinogenic inflammatory cytokine that plays a pivotal role in lung cancer development. Objectives: We assessed whether single nucleotide polymorphisms (SNPs) in the IL6 promoter are associated with lung cancer in former uranium miners with high occupational exposure to radon gas. Methods: Genetic associations were assessed in a case–control study of former uranium miners (242 cases and 336 controls). A replication study was performed using data from the Gene Environment Association Studies (GENEVA) Genome Wide Association Study (GWAS) of Lung Cancer and Smoking. Functional relevance of the SNPs was characterized using in vitro approaches. Results: We found that rs1800797 was associated with squamous cell carcinoma in miners and with a shorter time between the midpoint of the period of substantial exposure and diagnosis among the cases. Furthermore, rs1800797 was also associated with lung cancer among never smokers in the GENEVA dataset. Functional studies identified that the risk allele was associated with increased basal IL-6 mRNA level and greater promoter activity. Furthermore, fibroblasts with the risk allele showed greater induction of IL-6 secretion by hydrogen peroxide or benzo[a]pyrene diolepoxide treatments. Conclusions: An IL6 promoter variant was associated with lung cancer in uranium miners and never smokers in two external study populations. The associations are strongly supported by the functional relevance that the IL6 promoter SNP affects basal expression and carcinogen-induced IL-6 secretion. Citation: Leng S, Thomas CL, Snider AM, Picchi MA, Chen W, Willis DG, Carr TG, Krzeminski J, Desai D, Shantu A, Lin Y, Jacobson MR, Belinsky SA. 2016. Radon exposure, IL-6 promoter variants, and lung squamous

  10. Wall-rock argillic alteration and uranium mineralization of the northwestern Strel'tsovka caldera

    NASA Astrophysics Data System (ADS)

    Andreeva, O. V.; Golovin, V. A.; Petrov, V. A.

    2010-02-01

    Alteration of rocks and localization of uranium mineralization in the northwestern Strel’tsovka caldera are exemplified in the Dal’nee deposit. In the main parameters of hydrothermal mineralization (temperature, pH, pressure, and composition of solution), the Dal’nee deposit differs from the deposits of the Strel’tsovka ore field located in the central part of the caldera. The localization of high-grade stratiform orebodies are interpreted in light of kinematic relations between steeply and gently dipping faults that formed in the tectonic setting of the NE-SW-trending, long-living, right-lateral, strike-slip faulting. The wide halos of argillic alteration and the structural control of uranium mineralization are caused by the fact that the deposit is located at the margin of the geological block, which has developed since the Late Triassic in a regime of extension (pull-apart) to form a depression, which is arranged en echelon relative to the main caldera and comparable to it in area. Currently, this depression is overlapped by sediments of the Sukhoi Urulyungui Basin. Such a structure markedly increases the probability of finding hidden uranium ores associated with low-temperature argillic alteration in the volcanosedimantary rocks and granitoid basement of the northwestern Strel’tsovka caldera.

  11. Spectral discrimination of uranium-mineralized breccia pipes in northwestern Arizona

    SciTech Connect

    Kwarteng, A.Y.; Goodell, P.C.; Pingitore, N.E. Jr.; Wenich, K.J.

    1989-03-01

    The price of uranium is currently the lowest in more than a decade. The only type of uranium deposit that is economically viable in the depressed uranium market is such high-grade ore as the unconformity type found in Canada and Australia. Exploration for uranium-bearing breccia pipes in northwestern Arizona by both domestic and foreign companies is currently active because of the relatively high-grade ore they contain and their tendency to be polymetallic. In the US, uranium-mineralized breccia pipes are one of the few deposits that can compete in the current market. A stepwise discriminant analysis was performed on spectral data acquired from the field, laboratory, and Landsat thematic mapper (TM). The principal objectives were (1) to investigate the fundamental differences in the spectral properties of outcrops on the surface of breccia pipes and the background, (2) to choose TM bandpasses that were statistically optimum for distinguishing between breccia pipes and the background, and (3) to compare the results of the field, laboratory, and TM digital data which were acquired by different instruments having different spatial and spectral resolutions.

  12. Uranium Immobilization and Nanofilm Formation on Magnesium-Rich Minerals.

    PubMed

    van Veelen, Arjen; Bargar, John R; Law, Gareth T W; Brown, Gordon E; Wogelius, Roy A

    2016-04-01

    Polarization-dependent grazing incidence X-ray absorption spectroscopy (XAS) measurements were completed on oriented single crystals of magnesite [MgCO3] and brucite [Mg(OH)2] reacted with aqueous uranyl chloride above and below the solubility boundaries of schoepite (500, 50, and 5 ppm) at pH 8.3 and at ambient (PCO2 = 10(-3.5)) or reduced partial pressures of carbon dioxide (PCO2 = 10(-4.5)). X-ray absorption near edge structure (XANES) spectra show a striking polarization dependence (χ = 0° and 90° relative to the polarization plane of the incident beam) and consistently demonstrated that the uranyl molecule was preferentially oriented with its Oaxial═U(VI)═Oaxial linkage at high angles (60-80°) to both magnesite (101̅4) and brucite (0001). Extended X-ray absorption fine structure (EXAFS) analysis shows that the "effective" number of U(VI) axial oxygens is the most strongly affected fitting parameter as a function of polarization. Furthermore, axial tilt in the surface thin films (thickness ∼ 21 Å) is correlated with surface roughness [σ]. Our results show that hydrated uranyl(-carbonate) complexes polymerize on all of our experimental surfaces and that this process is controlled by surface hydroxylation. These results provide new insights into the bonding configuration expected for uranyl complexes on the environmentally significant carbonate and hydroxide mineral surfaces. PMID:26990311

  13. Wyartite: Crystallographic evidence for the first pentavalent-uranium mineral

    SciTech Connect

    Burns, P.C.; Finch, R.J.

    1999-09-01

    Determination of the structure of wyartite provides the first evidence for a pentavalent-U mineral. The structure of wyartite, CaU{sup 5+}(UO{sub 2}){sub 2}(CO{sub 3})O{sub 4}(OH)(H{sub 2}O), was solved by direct methods and refined to an agreement index (R) of 4.9% for 2309 unique reflections collected using MoK{alpha}X-radiation and a CCD-based detector. The structure contains three unique U positions; two contain U{sup 6+} and involve uranyl ions with typical pentagonal-bipyramidal coordination. Seven anions coordinate the other U position, but there is no uranyl ion present. The polyhedral geometry, the bond-valence sum incident at this U site, and electroneutrality requirements, all indicate that this site contains U{sup 5+}. The U{phi}{sub 7} ({phi}: O, OH, H{sub 2}O) polyhedra share edges and corners to form a unique sheet in which a CO{sub 3} group shares an edge with the U{sup 5+}{phi}{sub 7} polyhedron. The structure contains one Ca site coordinated by seven anions. The Ca atom and its associated H{sub 2}O groups occupy interlayer sites, along with two H{sub 2}O groups that are held in the structure by H bonds only. The Ca{phi}{sub 7} polyhedron is linked to one adjacent sheet by sharing an edge with the CO{sub 3} group and an O atom with a U{sup 6+}{phi}{sub 7} polyhedron. Structural units are linked together through hydrogen bonds only.

  14. Dissolution of Uranium-Bearing Minerals and Mobilization of Uranium by Organic Ligands in a Biologically Reduced Sediment

    SciTech Connect

    Luo, Wensui; Gu, Baohua

    2011-01-01

    The stability and mobility of uranium (U) is a concern following its reductive precipitation or immobilization by techniques such as bioremediation at contaminated sites. In this study, the influences of complexing organic ligands such as citrate and ethylenediaminetetraacetate (EDTA) on the mobilization of U were investigated in both batch and column flow systems using a contaminated and bioreduced sediment. Results indicate that both reduced U(IV) and oxidized U(VI) in the sediment can be effectively mobilized with the addition of EDTA or citrate under anaerobic conditions. The dissolution and mobilization of U appear to be correlated to the dissolution of iron (Fe)- or aluminum (Al)-bearing minerals, with EDTA being more effective (with R2 0.89) than citrate (R2 <0.60) in dissolving these minerals. The column flow experiments confirm that U, Fe, and Al can be mobilized by these ligands under anoxic conditions, although the cumulative amounts of U removal constituted ~0.1% of total U present in this sediment following a limited period of leaching. This study concludes that the presence of complexing organic ligands may pose a long-term concern by slowly dissolving U-bearing minerals and mobilizing U even under a strict anaerobic environment.

  15. X-ray absorption studies of uranium sorption on mineral substrates

    SciTech Connect

    Hudson, E.A.; Terminello, L.J.; Viani, B.E.; Reich, T.; Bucher, J.J.; Shuh, D.K.; Edelstein, N.M.

    1995-09-01

    Aqueous transport of actinides in the geosphere can be significantly retarded by sorption and/or precipitation upon mineral surfaces. Despite the importance of this effect to environmental remediation efforts and nuclear waste repository design, there is only limited direct knowledge about the microscopic nature of the actinide-mineral interaction. Here, uranium L{sub 3}-edge x-ray absorption spectra have been measured for uranium-mineral sorption systems. An expansible layer silicate, vermiculite, was treated to obtain a collapsed phase, thereby limiting access to the interior cation exchange sites. Samples were prepared by exposing the finely powdered mineral, in the natural and modified form, to aqueous solutions of uranyl chloride. EXAFS spectra of the encapsulated samples were measured at the Stanford Synchrotron Radiation Laboratory. Results indicate that the uranyl ion possesses a more symmetric local structure for the natural vermiculite than for the collapsed form, suggesting structural differences between uranyl species within the interlayer regions of vermiculite and on the external surfaces.

  16. Incidence of non-lung solid cancers in Czech uranium miners: A case-cohort study

    SciTech Connect

    Kulich, M.; Rericha, V.; Rericha, R.; Shore, D.L.; Sandler, D.P.

    2011-04-15

    Objectives: Uranium miners are chronically exposed to radon and its progeny, which are known to cause lung cancer and may be associated with leukemia. This study was undertaken to evaluate risk of non-lung solid cancers among uranium miners in Pribram region, Czech Republic. Methods: A retrospective stratified case-cohort study in a cohort of 22,816 underground miners who were employed between 1949 and 1975. All incident non-lung solid cancers were ascertained among miners who worked underground for at least 12 months (n=1020). A subcohort of 1707 subjects was randomly drawn from the same population by random sampling stratified on age. The follow-up period lasted from 1977 to 1996. Results: Relative risks comparing 180 WLM (90th percentile) of cumulative lifetime radon exposure to 3 WLM (10th percentile) were 0.88 for all non-lung solid cancers combined (95% CI 0.73-1.04, n=1020), 0.87 for all digestive cancers (95% CI 0.69-1.09, n=561), 2.39 for gallbladder cancer (95% CI 0.52-10.98, n=13), 0.79 for larynx cancer (95% CI 0.38-1.64, n=62), 2.92 for malignant melanoma (95% CI 0.91-9.42, n=23), 0.84 for bladder cancer (95% CI 0.43-1.65, n=73), and 1.13 for kidney cancer (95% CI 0.62-2.04, n=66). No cancer type was significantly associated with radon exposure; only malignant melanoma and gallbladder cancer showed elevated but non-significant association with radon. Conclusions: Radon was not significantly associated with incidence of any cancer of interest, although a positive association of radon with malignant melanoma and gallbladder cancer cannot be entirely ruled out. - Research highlights: {yields} Uranium miners are chronically exposed to radon. {yields} We evaluate risk of non-lung solid cancers among uranium miners. {yields} No cancer type was significantly associated with radon exposure. {yields} Malignant melanoma and gallbladder cancer showed non-significant elevated risk.

  17. Mineral-Water Interface Processes Affecting Uranium Fate in Contaminated Sediments

    NASA Astrophysics Data System (ADS)

    Catalano, J. G.

    2011-12-01

    Widespread uranium contamination of soil, sediments, and groundwater systems has resulted from mining activities, nuclear weapon production, and energy generation. The fate and transport of uranium in such systems is strongly affected by geochemical processes occurring at mineral-water interfaces. I will present a summary of the mineral-water interface processes found to affect uranium fate in example contaminated sediments at the U.S. Department of Energy's Hanford sites and in related model systems. Processes occurring under oxic conditions will be the primary focus of this talk as under these conditions uranium is most mobile and thus presents the greatest hazard. Three dominant solid-phase uranium species are observed in contaminated soil and sediments at the Hanford site: uranyl silicates, uranyl phosphates, and uranyl adsorbed to clays and iron oxides. In deep sediments, uranyl silicates are found in microfractures in feldspar grains, likely because slow diffusion in such fractures maintains a high silicate activity. Such silicates are also found in waste-impacted shallow sediments and soil; waste fluids or evaporative processes may have generated the silicate activity needed to produce such phases. Uranyl phosphates are less abundant, occurring primarily in shallow sediments exposed to P-bearing waste fluids. However, remediation approaches under consideration may produce substantial quantities of uranyl phosphates in the future. Adsorbed uranyl is dispersed throughout contaminated soils and shallow sediments and likely has the greatest potential for remobilization. Analogue studies show that precipitation of uranyl phosphates is rapid when such phases are supersaturated and that both homogeneous and heterogeneous nucleation may occur. Specific adsorption of uranyl to minerals is strongly affected by the presence of complexation anions. Carbonate suppresses uranyl adsorption but also forms uranyl-carbonate ternary surface complexes. At conditions below

  18. German uranium miner study--historical background and available histopathological material.

    PubMed

    Wesch, H; Wiethege, T; Spiethoff, A; Wegener, K; Müller, K M; Mehlhorn, J

    1999-12-01

    Mining activities in the former German Democratic Republic were documented as early as 1168 in the ore mountains (Erzgebirge) of Saxony. Silver, bismuth, cobalt, nickel and tungsten were mined from then up to the end of the 19th century. After the Second World War, the Soviet Occupation Authorities reopened the old silver mines in Saxony to mine uranium for the Soviet nuclear industry. About 400, 000 workers produced a total of 220,000 tons of uranium during the years 1946 to 1990. After the reunification of Germany, the archive of the Institute of Pathology of the mining area was opened for research. It contains protocols of 28,975 autopsy cases and about 400,000 slides collected from 1957 to 1992, about 66,000 tissue blocks, and 238 whole lungs. From the autopsy cases, 17,466 could be identified as workers of the uranium mining company. The remainder of the cases were in the population of the mining area. A comparison of the frequencies of malignancies of male workers older than 15 years with those of the population of the mining area for the years 1957 to 1989 demonstrates a significantly higher percentage of lung cancer among the uranium miners. There was no significant difference for other solid cancers and leukemias. PMID:10564936

  19. Potentiation of cigarette smoking and radiation: evidence from a sputum cytology survey among uranium miners and controls

    SciTech Connect

    Band, P.; Feldstein, M.; Saccomanno, G.; Watson, L.; King, G.

    1980-03-15

    To assess the effect of cigarette smoking and of exposure to radon daughters, a prospective survey consisting of periodic sputum cytology evaluation was initiated among 249 underground uranium miners and 123 male controls. Sputum cytology specimens showing moderate atypia, marked atypia, or cancer cells were classified as abnormal. As compared to control smokers, miners who smoke had a significantly higher incidence of abnormal cytology (P = 0.025). For miner smokers, the observed frequencies of abnormal cytology were linearly related to cumulative exposure to radon daughters and to the number of years of uranium mining. A statistical model relating the probability of abnormal cytology to the risk factors was investigated using a binary logistic regression. The estimated frequency of abnormal cytology was significantly dependent, for controls, on the duration of cigarette smoking, and for miners, on the duration of cigarette smoking and of uranium mining.

  20. Uranium (-nickel-cobalt-molybdenum) mineralization along the Singhbhum copper belt, India, and the problem of ore genesis

    NASA Astrophysics Data System (ADS)

    Sarkar, S. C.

    1982-08-01

    Uranium mineralization is present at many places along the 200 km long Singhbhum copper belt, but the mineralization is relatively concentrated at the central part of it. The belt is characterized by many shear zone features, such as mylonites, phyllonites, and L-S type of structures and of course, copious metasomatism. Country rocks are basic schists, metapelites, quartzose rocks and albite schist/gneiss (‘Soda Granite’). Orebodies are sheet-like, conformable with the pervasive planar structures in the host rocks. No pronounced ‘wall rock alteration’ accompanied the mineralization. Grade of the ore is low (<0.1% U3O8). The principal uraniferous mineral uraninite occurs as dissemination. Other uranium-bearing minerals include pitchblende, allanite, xenotime, davidite, clarkeite, autunite (-metaautunite), torbernite, schoepite (-metaschoepite) and uranophane. Uranium is also present in a number of refractory phases either as inclusion of uraninite or in the crystal structure. Additionally, nickel, cobalt and molybdenum are present at Jaduguda-Bhatin in the form of millerite, gersdorffite, melonite, nickel-bearing pyrite, molybdenite etc. Dominance of uraninite over pitchblende and the larger cell-edge of uraninite, development of hematite-bearing quartz and Na-oligoclase at places in the ore zone, association of uranium mineralization with Ni-Co-Mo(-S-As) mineralization at Jaduguda-Bhatin and continuation of the orebodies to considerable depths, suggest that the uranium mineralization along the Singhbhum belt belongs to moderate to high temperature ‘vein type’. The age obtained by Pb207/Pb206 ratio and the concordia method suggest that the uranium mineralization in Singhbhum took place 1500 1600 Ma ago and this age is not far different from the age of formation of uranium-vein deposits in many other Precambrian shields of the world. The following two mechanisms of the formation of the deposits are discussed: 1) uranium precipitated in the Dhanjori basal

  1. Uranium mineral - groundwater equilibration at the Palmottu natural analogue study site, Finland

    SciTech Connect

    Ahonen, L.; Ruskeeniemi, T.; Blomqvist, R.; Ervanne, H.; Jaakkola, T.

    1993-12-31

    The redox-potential, pH, chemical composition of fracture waters, and uraninite alteration associated with the Palmottu uranium mineralization, have been studied. The data have been interpreted by means of thermodynamic calculations. The results indicate equilibrium between uraninite, ferric hydroxide and groundwater in the bedrock of the study site. Partially oxidized uraninite (UO{sub 2.33}) and ferric hydroxide are in equilibrium with the fresh, slightly acidic and oxidized water type, while primary uraninite is stable with deeper waters that have a higher pH and lower Eh. Measured Eh-pH values of groundwater cluster within a relatively narrow range indicating buffering by heterogeneous redox-processes. A good consistency between measured Eh and analyzed uranium oxidation states was observed.

  2. Exploration techniques for locating uranium-mineralized breccia pipes in northern Arizona

    SciTech Connect

    Wenrich, K.J.

    1986-05-01

    Thousands of solution-collapse breccia pipes may crop out in the canyons and on the plateaus of northern Arizona, and more than 80 contain uranium or copper mineralized rock; however, their small size and limited rock outcrop make them difficult to locate. Recognition of the pipes on the plateaus is particularly important because mining access to the plateaus is far easier than to the canyons. Several reconnaissance geochemical methods have been tested to help locate suspected and mineralized breccia pipes. (1) A hydrogeochemical survey conducted on the 1500 mi/sup 2/ (4000 km/sup 2/) Hualapai Indian Reservation appears to yield anomalous values downstream from regions, such as Mohawk Canyon, where clusters of mineralized pipes occur. Pigeon Spring, east of the Pigeon mine, also had anomalous uranium (44 ppb). (2) A stream-sediment survey was not made on the Hualapai Reservation because the dilution factor that results from the large volume of country rock, compared to that of mineralized rock, swamps out any low-level geochemical signature contributed to streams by rock or soil overlying breccia pipes. Several types of detailed geochemical and geophysical surveys, made over individual collapse features located through examination of aerial photographs and later field mapping, have generally been successful at delineating collapse features from the surrounding host rock: (1) rock geochemistry commonly shows Ag, As, Ba, Cu, Pb, Se, and/or Zn enrichments of from 3 to 100 times background levels over mineralized breccia pipes; (2) soil surveys appear to have the greatest exploration potential of the geochemical methods (e.g., samples collected from the centers of several collapse features show consistently twice the background value for a number of elements);

  3. What are the health costs of uranium mining? A case study of miners in Grants, New Mexico

    PubMed Central

    Jones, Benjamin A

    2014-01-01

    Background: Uranium mining is associated with lung cancer and other health problems among miners. Health impacts are related with miner exposure to radon gas progeny. Objectives: This study estimates the health costs of excess lung cancer mortality among uranium miners in the largest uranium-producing district in the USA, centered in Grants, New Mexico. Methods: Lung cancer mortality rates on miners were used to estimate excess mortality and years of life lost (YLL) among the miner population in Grants from 1955 to 2005. A cost analysis was performed to estimate direct (medical) and indirect (premature mortality) health costs. Results: Total health costs ranged from $2.2 million to $7.7 million per excess death. This amounts to between $22.4 million and $165.8 million in annual health costs over the 1955–1990 mining period. Annual exposure-related lung cancer mortality was estimated at 2185.4 miners per 100 000, with a range of 1419.8–2974.3 per 100 000. Conclusions: Given renewed interest in uranium worldwide, results suggest a re-evaluation of radon exposure standards and inclusion of miner long-term health into mining planning decisions. PMID:25224806

  4. Lung cancer mortality among U.S. uranium miners: a reappraisal.

    PubMed

    Whittemore, A S; McMillan, A

    1983-09-01

    This report examines lung cancer mortality among a cohort of white underground uranium miners in the Colorado plateau and is based on mortality follow-up through December 31, 1977. The analytic methods represent a miner's annual age-specific lung cancer mortality rate as the (unspecified) rate among nonsmoking men born at the same time and with no mining history, multiplied by the relative risk factor R. This factor depends on the miner's total exposures to radon daughters [in working level months (WLM) and to cigarettes (in packs), accumulated from start of exposure until 10 years before his current age. Among those examined, the relative risk function giving the highest likelihood of the data was R = (1 + 0.31 X 10(-2) WLM)(1 + 0.51 X 10(-3) packs). This multiplicative function specifies that ratios of mortality rates for miners versus nonminers with similar age and smoking characteristics do not depend on smoking status. By contrast, differences between miners' and nonminers' mortality rates are substantially higher for smokers than for nonsmokers. The data rejected (P = .01) several additive functions for R that specify relative risk as a sum of components due to radiation and to cigarette smoking. Cumulative exposures to both radiation and cigarettes gave better fits to the data than did average annual exposure rates. Age at start of underground mining had no effect on risk, after controlling for age at lung cancer death, year of birth, and cumulative radiation and smoking exposures. PMID:6577225

  5. Kidney cancer mortality and ionizing radiation among French and German uranium miners.

    PubMed

    Drubay, Damien; Ancelet, Sophie; Acker, Alain; Kreuzer, Michaela; Laurier, Dominique; Rage, Estelle

    2014-08-01

    The investigation of potential adverse health effects of occupational exposures to ionizing radiation, on uranium miners, is an important area of research. Radon is a well-known carcinogen for lung, but the link between radiation exposure and other diseases remains controversial, particularly for kidney cancer. The aims of this study were therefore to perform external kidney cancer mortality analyses and to assess the relationship between occupational radiation exposure and kidney cancer mortality, using competing risks methodology, from two uranium miners cohorts. The French (n = 3,377) and German (n = 58,986) cohorts of uranium miners included 11 and 174 deaths from kidney cancer. For each cohort, the excess of kidney cancer mortality has been assessed by standardized mortality ratio (SMR) corrected for the probability of known causes of death. The associations between cumulative occupational radiation exposures (radon, external gamma radiation and long-lived radionuclides) or kidney equivalent doses and both the cause-specific hazard and the probability of occurrence of kidney cancer death have been estimated with Cox and Fine and Gray models adjusted to date of birth and considering the attained age as the timescale. No significant excess of kidney cancer mortality has been observed neither in the French cohort (SMR = 1.49, 95 % confidence interval [0.73; 2.67]) nor in the German cohort (SMR = 0.91 [0.77; 1.06]). Moreover, no significant association between kidney cancer mortality and any type of occupational radiation exposure or kidney equivalent dose has been observed. Future analyses based on further follow-up updates and/or large pooled cohorts should allow us to confirm or not the absence of association. PMID:24858911

  6. Uranium Isotopic Fractionation Induced by U(VI) Adsorption Onto Common Aquifer Minerals

    NASA Astrophysics Data System (ADS)

    Jemison, N.; Johnson, T. M.; Shiel, A. E.; Lundstrom, C.

    2014-12-01

    Mining and processing of uranium (U) ore for nuclear energy and weapons has led to U contamination of groundwater. Reduction of soluble, mobile U(VI) to UO2 decreases uranium groundwater concentrations and is an important driver of natural and stimulated attenuation. 238U/235U measurements can be used to monitor and perhaps quantify U(VI) reduction; biological reduction of U(VI) has been shown to produce a ~1.0‰ isotopic fractionation in both laboratory and field settings, with the reduced product enriched in 238U. However, adsorption of U(VI) onto minerals may complicate the use of 238U/235U in this application; adsorption of U(VI) onto Mn oxides induces an isotopic fractionation of 0.2‰ with the sorbed U(VI) depleted in 238U. At present, the isotopic shift produced by adsorption of U(VI) onto other minerals has not yet been explored. This study measures U isotopic fractionation during adsorption onto goethite, birnessite, quartz, illite, and complex aquifer materials. In addition, the effect of U speciation on fractionation is also examined by adsorption of uranyl (UO22+), uranyl carbonato (such as UO2(CO3)22- and UO2(CO3)34-), and calcium uranyl carbonato (Ca2UO2(CO3)3(aq) and CaUO2(CO3)32-) ions to goethite and birnessite. Experiments are carried out with a multi-stage, batch approach, in which a U(VI)-bearing solution is exposed to three stages of adsorption, and the final solution is analyzed by a double-spike MC-ICP-MS method. This increases our ability to resolve among sorbents the extent of fractionation. Early results suggest that uranium adsorption to different minerals produces different isotopic fractionations, with quartz producing little to no fractionation (<0 .05‰), while goethite produces a 0.16‰ isotopic shift (adsorbed U(VI) depleted in 238U).

  7. Interaction between aqueous uranium (VI) and sulfide minerals: Spectroscopic evidence for sorption and reduction

    SciTech Connect

    Wersin, P.; Hochella, M.F. Jr.; Persson, P.; Redden, G.; Leckie, J.O. ); Harris, D.W. )

    1994-07-01

    The interaction of aqueous U(VI) with galena and pyrite surfaces under anoxic conditions has been studied by solution analysis and by spectroscopic methods. The solution data indicate that uranyl uptake is strongly dependent on pH; maximum uptake (>98%) occurs above a pH range of between 4.8 and 5.5, depending on experimental conditions. Increasing the sorbate/sorbent ratio results in a relative decrease in uptake of uranyl and in slower sorption kinetics. Auger electron spectroscopy analysis indicates an inhomogeneous distribution of sorbed uranium at the surface. In the case of galena, formation of small precipitates ([approximately] 40 nm wide needles) of a uranium oxide compound are found. Pyrite shows a patchy distribution of uranium, mainly associated with oxidized surface species of sulfur and iron. X-ray photoelectron spectroscopy yields insight into possible redox processes indicating, for both sulfides, the concomitant formation of polysulfides and a uranium oxide compound with a mixed oxidation state at a U(VI)/U(IV) ratio of [approximately] 2. Furthermore, in the case of pyrite, at pH above 6 increased oxidation of sulfur and iron and higher relative amounts of unreduced surface-uranyl are observed. Fourier Transformed Infrared analysis of surface-bound uranyl shows a significant shift of the asymmetric stretching frequency to lower wavenumbers which is consistent with the formation of a U[sub 3]O[sub 8]-type compound and thus, independently, confirms the partial reduction of uranyl at the sulfide surface. The combination of AES, XPS, and FTIR provides a powerful approach for identifying mechanisms that govern the interaction of redox sensitive compounds in aqueous systems. The overall results indicate that sulfide minerals are efficient scavengers of soluble uranyl. Comparing the results with recent field observations, the authors suggest that thermodynamically metastable U[sub 3]O[sub 8] controls uranium concentrations in many anoxic groundwaters.

  8. Investigation on Microbial Dissolution of Uranium (VI) from Autunite Mineral - 13421

    SciTech Connect

    Sepulveda, Paola; Katsenovich, Yelena; Lagos, Leonel

    2013-07-01

    Precipitating autunite minerals by polyphosphate injection was identified as a feasible remediation strategy for sequestering uranium in contaminated groundwater and soil in situ at the Hanford Site. Autunite stability under vadose and saturated zone environmental conditions can help to determine the long-term effectiveness of this remediation strategy. The Arthrobacter bacteria are one of the most common groups in soils and are found in large numbers in Hanford soil as well as other subsurface environments contaminated with radionuclides. Ubiquitous in subsurface microbial communities, these bacteria can play a significant role in the dissolution of minerals and the formation of secondary minerals. The main objective of this investigation was to study the bacterial interactions under oxidizing conditions with uranium (VI); study the potential role of bicarbonate, which is an integral complexing ligand for U(VI) and a major ion in groundwater compositions; and present data from autunite dissolution experiments using Arthrobacter strain G968, a less U(VI)-tolerant strain. Sterile 100 mL glass mixed reactors served as the major bioreactor for initial experimentation. These autunite-containing bioreactors were injected with bacterial cells after the autunite equilibrated with the media solution amended with 0 mM, 3 mM 5 mM and 10 mM concentrations of bicarbonate. G968 Arthrobacter cells in the amount of 10{sup 6} cells/mL were injected into the reactors after 27 days, giving time for the autunite to reach steady state. Abiotic non-carbonate controls were kept without bacterial inoculation to provide a control for the biotic samples. Samples of the solution were analyzed for dissolved U(VI) by means of kinetic phosphorescence analyzer KPA-11 (Chemcheck Instruments, Richland, WA). Analysis showed that as [HCO{sub 3}{sup -}] increases, a diminishing trend on the effect of bacteria on autunite leaching is observed. Viability of cells was conducted after 24 hours of cell

  9. PHASE ANALYSES OF URANIUM-BEARING MINERALS FROM THE HIGH GRADE ORE, NOPAL I, PENA BLANCA, MEXICO

    SciTech Connect

    M. Ren; P. Goodell; A. Kelts; E.Y. Anthony; M. Fayek; C. Fan; C. Beshears

    2005-07-11

    The Nopal I uranium deposit is located in the Pena Blanca district, approximately 40 miles north of Chihuahua City, Mexico. The deposit was formed by hydrothermal processes within the fracture zone of welded silicic volcanic tuff. The ages of volcanic formations are between 35 to 44 m.y. and there was secondary silicification of most of the formations. After the formation of at least part of the uranium deposit, the ore body was uplifted above the water table and is presently exposed at the surface. Detailed petrographic characterization, electron microprobe backscatter electron (BSE) imagery, and selected x-ray maps for the samples from Nopal I high-grade ore document different uranium phases in the ore. There are at least two stages of uranium precipitation. A small amount of uraninite is encapsulated in silica. Hexavalent uranium may also have been a primary precipitant. The uranium phases were precipitated along cleavages of feldspars, and along fractures in the tuff. Energy dispersive spectrometer data and x-ray maps suggest that the major uranium phases are uranophane and weeksite. Substitutions of Ca and K occur in both phases, implying that conditions were variable during the mineralization/alteration process, and that compositions of the original minerals have a major influence on later stage alteration. Continued study is needed to fully characterize uranium behavior in these semi-arid to arid conditions.

  10. Lung cancer mortality among nonsmoking uranium miners exposed to radon daughters

    SciTech Connect

    Roscoe, R.J.; Steenland, K.; Halperin, W.E.; Beaumont, J.J.; Waxweiler, R.J.

    1989-08-04

    Radon daughters, both in the workplace and in the household, are a continuing cause for concern because of the well-documented association between exposure to radon daughters and lung cancer. To estimate the risk of lung cancer mortality among nonsmokers exposed to varying levels of radon daughters, 516 white men who never smoked cigarettes, pipes, or cigars were selected from the US Public Health Service cohort of Colorado Plateau uranium miners and followed up from 1950 through 1984. Age-specific mortality rates for nonsmokers from a study of US veterans were used for comparison. Fourteen deaths from lung cancer were observed among the nonsmoking miners, while 1.1 deaths were expected, yielding a standardized mortality ratio of 12.7 with 95% confidence limits of 8.0 and 20.1. These results confirm that exposure to radon daughters in the absence of cigarette smoking is a potent carcinogen that should be strictly controlled.

  11. The role of anaerobic respiration in the immobilization of uranium through biomineralization of phosphate minerals

    NASA Astrophysics Data System (ADS)

    Salome, Kathleen R.; Green, Stefan J.; Beazley, Melanie J.; Webb, Samuel M.; Kostka, Joel E.; Taillefert, Martial

    2013-04-01

    Although bioreduction of uranyl ions (U(VI)) and biomineralization of U(VI)-phosphate minerals are both able to immobilize uranium in contaminated sediments, the competition between these processes and the role of anaerobic respiration in the biomineralization of U(VI)-phosphate minerals has yet to be investigated. In this study, contaminated sediments incubated anaerobically in static microcosms at pH 5.5 and 7.0 were amended with the organophosphate glycerol-2-phosphate (G2P) as sole phosphorus and external carbon source and iron oxides, sulfate, or nitrate as terminal electron acceptors to determine the most favorable geochemical conditions to these two processes. While sulfate reduction was not observed even in the presence of G2P at both pHs, iron reduction was more significant at circumneutral pH irrespective of the addition of G2P. In turn, nitrate reduction was stimulated by G2P at both pH 5.5 and 7.0, suggesting nitrate-reducing bacteria provided the main source of inorganic phosphate in these sediments. U(VI) was rapidly removed from solution in all treatments but was not reduced as determined by X-ray absorption near edge structure (XANES) spectroscopy. Simultaneously, wet chemical extractions and extended X-ray absorption fine structure (EXAFS) spectroscopy of these sediments indicated the presence of U-P species in reactors amended with G2P at both pHs. The rapid removal of dissolved U(VI), the simultaneous production of inorganic phosphate, and the existence of U-P species in the solid phase indicate that uranium was precipitated as U(VI)-phosphate minerals in sediments amended with G2P. Thus, under reducing conditions and in the presence of G2P, bioreduction of U(VI) was outcompeted by the biomineralization of U(VI)-phosphate minerals and U(VI) sorption at both pHs.

  12. Structure of uranium sorption complexes on alumino-silicate minerals studied by x-ray absorption spectroscopy

    SciTech Connect

    Hudson, E.A.; Terminello, L.J.; Viani, B.E.

    1996-10-01

    The local geometry of uranium bound to mineral surfaces was investigated by uranium L{sub 3}-edge EXAFS. Uranium(6+) in solution was exposed to vermiculite and clinoptilolite, under conditions which favor sorption by either cation exchange or surface complexation. The aqueous speciation of uranium in each solution was predicted using the thermodynamic modeling code EQ3/6, and is dominated by complexes of the uranyl ion (UO{sub 2}{sup 2+}). EXAFS of the resulting mineral samples indicates that in all cases the sorbed species is a monomeric uranyl complex. A larger distortion of the uranyl equatorial shell is observed for cation exchange, possibly due to steric effects at internal cation exchange sites. The uranyl U-O axial bond distance is greater for surface complexation than for ion exchange.

  13. Uranium in big sagebrush from western U.S. and evidence of possible mineralization in the Owyhee mountains of Idaho

    USGS Publications Warehouse

    Erdman, J.A.; Harrach, G.H.

    1981-01-01

    Two regional studies of big sagebrush (Artemisia tridentata), a widely distributed and dominant shrub in the western United States, have shown its responsiveness to known uranium mineralization in the Monument Hill and Pumpkin Buttes districts of the southern Powder River Basin, Wyoming, and the Uravan mineral belt area in southeastern Utah and southwestern Colorado. Uranium concentrations in the ash of 154 stem-and-leaf samples of sagebrush are plotted on two maps, one representing the sampling design for the Powder River Basin study, and the other representing the sampling design for the Colorado Plateaus, the Basin and Range, and the Columbia Plateaus physiographic provinces of the West. Sites having high concentrations in sagebrush correspond not only to the above uranium districts, but also reveal an area along the northeast flanks of the Owyhee Mountains in Idaho that should be further explored for its possible uranium potential.

  14. Healthy worker survivor bias in the Colorado Plateau uranium miners cohort.

    PubMed

    Keil, Alexander P; Richardson, David B; Troester, Melissa A

    2015-05-15

    Cohort mortality studies of underground miners have been used to estimate the number of lung cancer deaths attributable to radon exposure. However, previous studies of the radon-lung cancer association among underground miners may have been subject to healthy worker survivor bias, a type of time-varying confounding by employment status. We examined radon-mortality associations in a study of 4,124 male uranium miners from the Colorado Plateau who were followed from 1950 through 2005. We estimated the time ratio (relative change in median survival time) per 100 working level months (radon exposure averaging 130,000 mega-electron volts of potential α energy per liter of air, per working month) using G-estimation of structural nested models. After controlling for healthy worker survivor bias, the time ratio for lung cancer per 100 working level months was 1.168 (95% confidence interval: 1.152, 1.174). In an unadjusted model, the estimate was 1.102 (95% confidence interval: 1.099, 1.112)-39% lower. Controlling for this bias, we estimated that among 617 lung cancer deaths, 6,071 person-years of life were lost due to occupational radon exposure during follow-up. Our analysis suggests that healthy worker survivor bias in miner cohort studies can be substantial, warranting reexamination of current estimates of radon's estimated impact on lung cancer mortality. PMID:25837305

  15. Healthy Worker Survivor Bias in the Colorado Plateau Uranium Miners Cohort

    PubMed Central

    Keil, Alexander P.; Richardson, David B.; Troester, Melissa A.

    2015-01-01

    Cohort mortality studies of underground miners have been used to estimate the number of lung cancer deaths attributable to radon exposure. However, previous studies of the radon–lung cancer association among underground miners may have been subject to healthy worker survivor bias, a type of time-varying confounding by employment status. We examined radon-mortality associations in a study of 4,124 male uranium miners from the Colorado Plateau who were followed from 1950 through 2005. We estimated the time ratio (relative change in median survival time) per 100 working level months (radon exposure averaging 130,000 mega-electron volts of potential α energy per liter of air, per working month) using G-estimation of structural nested models. After controlling for healthy worker survivor bias, the time ratio for lung cancer per 100 working level months was 1.168 (95% confidence interval: 1.152, 1.174). In an unadjusted model, the estimate was 1.102 (95% confidence interval: 1.099, 1.112)—39% lower. Controlling for this bias, we estimated that among 617 lung cancer deaths, 6,071 person-years of life were lost due to occupational radon exposure during follow-up. Our analysis suggests that healthy worker survivor bias in miner cohort studies can be substantial, warranting reexamination of current estimates of radon's estimated impact on lung cancer mortality. PMID:25837305

  16. Inhibition Effect of Secondary Phosphate Mineral Precipitation on Uranium Release from Contaminated Sediments

    SciTech Connect

    Shi, Zhenqing; Liu, Chongxuan; Zachara, John M.; Wang, Zheming; Deng, Baolin

    2009-11-01

    The inhibitory effect of phosphate mineral precipitation on uranium release was evaluated using a U(VI)-contaminated sediment collected from the US Department of Energy (DOE) Hanford site. The sediment contained U(VI) that was associated with diffusion-limited intragrain regions within its mm-size granitic lithic fragments. The sediment was first treated to promote phosphate mineral precipitation in batch suspensions spiked with 1 and 50 mM aqueous phosphate, and calcium in a stoichiometric ratio of mineral hydroxyapatite. The phosphate-treated sediment was then leached to solubilize contaminant U(VI) in a column system using a synthetic groundwater that contained chemical components representative of Hanford groundwater. Phosphate treatment significantly decreased the extent of U(VI) release from the sediment. Within the experimental duration of about 200 pore volumes, the effluent U(VI) concentrations were consistently lower by over one and two orders of magnitude after the sediment was treated with 1 and 50 mM of phosphate, respectively. Measurements of solid phase U(VI) using various spectroscopes and chemical extraction of the sediment collectively indicated that the inhibition of U(VI) release from the sediment was caused by: 1) U(VI) adsorption to the secondary phosphate precipitates and 2) the transformation of initially present U(VI) mineral phases to less soluble forms.

  17. Radioactive mineral spring precipitates, their analytical and statistical data and the uranium connection

    USGS Publications Warehouse

    Cadigan, R.A.; Felmlee, J.K.

    1982-01-01

    Major radioactive mineral springs are probably related to deep zones of active metamorphism in areas of orogenic tectonism. The most common precipitate is travertine, a chemically precipitated rock composed chiefly of calcium carbonate, but also containing other minerals. The mineral springs are surface manifestations of hydrothermal conduit systems which extend downward many kilometers to hot source rocks. Conduits are kept open by fluid pressure exerted by carbon dioxide-charged waters rising to the surface propelled by heat and gas (CO2 and steam) pressure. On reaching the surface, the dissolved carbon dioxide is released from solution, and calcium carbonate is precipitated. Springs also contain sulfur species (for example, H2S and HS-), and radon, helium and methane as entrained or dissolved gases. The HS- ion can react to form hydrogen sulfide gas, sulfate salts, and native sulfur. Chemical salts and native sulfur precipitate at the surface. The sulfur may partly oxidize to produce detectable sulfur dioxide gas. Radioactivity is due to the presence of radium-226, radon-222, radium-228, and radon-220, and other daughter products of uranium-238 and thorium-232. Uranium and thorium are not present in economically significant amounts in most radioactive spring precipitates. Most radium is coprecipitated at the surface with barite. Barite (barium sulfate) forms in the barium-containing spring water as a product of the oxidation of sulfur species to sulfate ions. The relatively insoluble barium sulfate precipitates and removes much of the radium from solution. Radium coprecipitates to a lesser extent with manganese-barium- and iron-oxy hydroxides. R-mode factor analysis of abundances of elements suggests that 65 percent of the variance of the different elements is affected by seven factors interpreted as follows: (1) Silica and silicate contamination and precipitation; (2) Carbonate travertine precipitation; (3) Radium coprecipitation; (4) Evaporite precipitation

  18. U-Pb isotope systematics and age of uranium mineralization, Midnite mine, Washington.

    USGS Publications Warehouse

    Ludwig, K. R.; Nash, J.T.; Naeser, C.W.

    1981-01-01

    Uranium ores at the Midnite mine, near Spokane, Washington, occur in phyllites and calcsilicates of the Proterozoic Togo Formation, near the margins of an anomalously uraniferous, porphyritic quartz monzonite of Late Cretaceous age. The present geometry of the ore zones is tabular, with the thickest zones above depressions in the pluton-country rock contact. Analyses of high-grade ores from the mine define a 207 Pb/ 204 Pb- 235 U/ 204 Pb isochron indicating an age of mineralization of 51.0 + or - 0.5 m.y. This age coincides with a time of regional volcanic activity (Sanpoil Volcanics), shallow intrusive activity, erosion, and faulting. U-Th-Pb isotopic ages of zircons from the porphyritic quartz monzonite in the mine indicate an age of about 75 m.y., hence the present orebodies were formed about 24 m.y. after its intrusion. The 51-m.y. time of mineralization probably represents a period of mobilization and redeposition of uranium by supergene ground waters, perhaps aided by mild heating and ground preparation and preserved by a capping of newly accumulated, impermeable volcanic rocks. It seems most likely that the initial concentration of uranium occurred about 75 m.y. ago, probably from relatively mild hydrothermal fluids in the contact-metamorphic aureole of the U-rich porphyritic quartz monzonite.Pitchblende, coffinitc, pyrite, marcasite, and hisingerite are the most common minerals in the uranium-bearing veinlets, with minor sphalerite and chalcopyrite. Coffinitc with associated marcasite is paragenetically later than pitchblende, though textural and isotopic evidence suggests no large difference in the times of pitchblende and colfinite formation.The U-Pb isotope systematics of total ores and of pitchblende-coffinite and pyrite-marcasite separates show that whereas open system behavior for U and Pb is essentially negligible for large (200-500 g) ore samples, Pb migration has occurred on a scale of 1 to 10 mm (out of pitchblende and coffinite and into pyrite

  19. Ianthinite: A rare hydrous uranium oxide mineral from Akkavaram, Andhra Pradesh, India

    NASA Astrophysics Data System (ADS)

    Singh, Yamuna; Viswanathan, R.; Parashar, K. K.; Srivastava, S. K.; Ramesh Babu, P. V.; Parihar, P. S.

    2014-02-01

    Ianthinite is the only known uranyl oxide hydrate mineral that contains both U6 + and U4 + . For the first time, we report ianthinite from India (at Akkavaram, Andhra Pradesh), which is hosted in basement granitoids. The mineral occurs in the form of tiny grains, encrustations and coatings in intimate association with uraninite and uranophane. X-ray diffraction (XRD) data reveals that d-spacings of the investigated ianthinite are in close agreement with the corresponding values given for ianthinite standard in International Centre for Diffraction Data (ICDD) card no. 12-272. The crystallographic parameters of the studied ianthinite are: ao = 11.3 (1) Å, bo = 7.19 (3) Å and co = 30.46 (8) Å, with a unit cell volume of 2474 (27) Å3. The association of investigated ianthinite with uraninite suggests that the former has formed due to oxidation of the latter. Since a major part of the uraninite was exposed to oxidizing meteoric water, much of it has been transformed into hydrous uranium oxide (ianthinite) and very little part remained unaltered as uranium oxide (uraninite). Absence of schoepite in the investigated ianthinite suggests that after its formation it (ianthinite) was not exposed to oxygen/oxidizing meteoric water. As the oxidation was partial and short lived, some amount of primary uraninite is also preserved.

  20. Resource characterization for uranium mineralization in the Montrose 1/sup 0/ x 2/sup 0/ quadrangle, Colorado

    SciTech Connect

    Bolivar, S.L.; Balog, S.H.; Weaver, T.A.

    1981-01-01

    A data-classification scheme was developed to detect potential uranium mineralization in the Montrose 1/sup 0/ x 2/sup 0/ quadrangle, Colorado. The methodology developed is a rapid and efficient method of resource evaluation on a reconnaissance scale. The necessary techniques were developed and refined to digitize, integrate, and register various large geological, geochemical, and geophysical data sets for the Montrose quadrangle, Colorado, using a grid resolution of 1 km. All data sets for the Montrose quadrangle were registered to the Universal Transverse Mercator projection. The data sets include hydrogeochemical and stream sediment analyses for 23 elements, uranium-to-thorium ratios, airborne geophysical survey data, the locations of 90 uranium occurrences, and a geologic map (scale 1:250 000). Geochemical samples were collected from 3965 locations in the 19 200 km/sup 2/ quadrangle; aerial data were collected on flight lines flown with 3 to 5 km spacings. These data sets were smoothed by universal kriging and interpolated to a 179 x 119 rectangular grid (each grid block is 1 km/sup 2/). A mylar transparency of the geologic map was prepared and digitized. All possible combinations of three, for all data sets, were examined for general geologic correlations by utilizing a color microfilm output. Subsets of data were further examined for selected test areas. A classification scheme for uranium mineralization, based on selected test areas in the Cochetopa uranium district, is presented. Areas favorable for uranium mineralization, based on this scheme, were identified and are discussed.

  1. Application of gamma ray spectrometric measurements and VLF-EM data for tracing vein type uranium mineralization

    NASA Astrophysics Data System (ADS)

    Gaafar, Ibrahim

    2015-12-01

    This study is an attempt to use the gamma ray spectrometric measurements and VLF-EM data to identify the subsurface structure and map uranium mineralization along El Sela shear zone, South Eastern Desert of Egypt. Many injections more or less mineralized with uranium and associated with alteration processes were recorded in El Sela shear zone. As results from previous works, the emplacement of these injections is structurally controlled and well defined by large shear zones striking in an ENE-WSW direction and crosscut by NW-SE to NNW-SSE fault sets. VLF method has been applied to map the structure and the presence of radioactive minerals that have been delineated by the detection of high uranium mineralization. The electromagnetic survey was carried out to detect the presence of shallow and deep conductive zones that cross the granites along ENE-WSW fracturing directions and to map its spatial distribution. The survey comprised seventy N-S spectrometry and VLF-EM profiles with 20 m separation. The resulted data were displayed as composite maps for K, eU and eTh as well as VLF-Fraser map. Twelve profiles with 100 m separation were selected for detailed description. The VLF-EM data were interpreted qualitatively as well as quantitatively using the Fraser and the Karous-Hjelt filters. Fraser filtered data and relative current density pseudo-sections indicate the presence of shallow and deep conductive zones that cross the granites along ENE-WSW shearing directions. High uranium concentrations found just above the higher apparent current-density zones that coincide with El-Sela shear zone indicate a positive relation between conductivity and uranium minerals occurrence. This enables to infer that the anomalies detected by VLF-EM data are due to the highly conductive shear zone enriched with uranium mineralization extending for more than 80 m.

  2. Evolutionary and geological factors controlling endogenic uranium mineralization and the potential for the discovery of new ore districts

    NASA Astrophysics Data System (ADS)

    Mashkovtsev, G. A.; Miguta, A. K.; Shchetochkin, V. N.

    2015-03-01

    The exhaustion of known surface and near-surface high-grade uranium deposits poses the serious problem of prospecting and exploration of new large endogenic deposits. A comparison of large data sets for endogenic deposits from the world's major uranium districts allowed the authors to develop an evolutionary geological model of large-scale uranium ore genesis, which reflects the succession and nature of preore, ore-forming, and post-ore processes. The study reveals a combination of general (recurrent) factors controlling the formation of ore districts with large-scale uranium mineralization regardless of the genesis and timing of the mineralization. At the same time, these factors depend on the regional setting and can vary considerably among deposits of the same type localized in different tectonic blocks with different characteristics and structural evolution. In connection with this, the exploration of major genetic types of deposits requires the application of specified criteria. Along with the consideration of the evolutionary geological model of ore formation, the study discusses a variety of tectono-magmatic, mineralogical, geochemical, radiogeochemical, and physicochemical factors and indications in three uranium districts (the Streltsovskoe, Elkon, and Central Ukrainian districts), which can form the basis for further uranium prospecting and exploration. Using a combination of favorable prerequisite conditions the study compares the possibilities for the discovery of large endogenic uranium deposits in several regions of Russia.

  3. Quantitative risk assessment of lung cancer in U. S. uranium miners

    SciTech Connect

    Hornung, R.W.; Meinhardt, T.J.

    1986-01-16

    The mortality experience of a cohort of 3346 underground uranium miners evaluated in 1977 was updated through 1982. As of 1982, there were 1214 miners who were deceased; 255 had died of lung cancer. Variables considered in the development of the model included cumulative exposure, exposure rate, cumulative cigarette smoking, smoking rate, age at initial exposure, calendar year of initial exposure, birth year, height, duration of underground employment, and years of prior hardrock mining. Cumulative cigarette smoking and cumulative radon daughter exposure had a joint effect intermediate between additive and multiplicative, implying a synergistic relationship. Results indicated that modeling cumulative exposure alone may not adequately predict the relative risk of lung cancer from chronic exposure to radon daughters. Miners receiving a given amount of cumulative exposure at lower rates for longer periods of time were at greater risk relative to those with the same cumulative exposure received at higher rates for shorter time periods. Data suggested that radon daughters act at a late stage in the carcinogenic process. The epidemiologic model developed for the study was found to provide a very good fit to data from 60 to 6000 working level months.

  4. Remote sensing applied to the exploration for uranium-mineralized breccia pipes in northwestern Arizona

    SciTech Connect

    Kwarteng, A.M.Y.

    1988-01-01

    Exploration for uranium-mineralized breccia pipes in northwestern Arizona has been active because of the high-grade ore they contain, which may also include such by-products as Ag, Au, Cu, Pb, Zn, and V. These breccia pipes were formed from the collapse of the overlying sedimentary strata into karst caverns developed in the Mississippian Redwall Limestone; mineralization occurred between 200 and 220 m.y. ago as determined previously by U-Pb isotopic analyses. Spectroscopic and statistical analyses of field, laboratory, and digital Landsat Thermatic Mapper (TM) data were carried out to determine the fundamental spectral and mineralogical differences between samples on the surface of breccia pipes and their background areas. Spectroscopic and XRD mineralogical studies clearly demonstrate that hydrothermally altered rocks associated with mineralized breccia pipes are distinguished from the surrounding rocks by the Fe{sup 3+}, hydroxyl, and carbonate minerals content. Discriminant analyses of field, laboratory, and TM data indicates that 64-80% of the samples collected on the surfaces of breccia pipes and their immediately surrounding areas were correctly classified. Digitally enhanced TM images printed at the scale of 1:100,000 resulted in the recognition of more than 80% of previously known orebodies as well as additional anomalies identified in the study areas. Digital image processing techniques were applied to airborne geophysical data consisting of apparent resistivity, total-field magnetics, derived overburden thickness, and very low-frequency electromagnetics (VLF-EM) to evaluate the utility of the data sets for breccia pipe exploration. The processing and critical analysis of the geophysical data is apparently the most promising approach to breccia pipe exploration in this study.

  5. Uranium miner lung cancer study. Progress report, 1 July 1980-1 July 1981

    SciTech Connect

    Saccomanno, G.

    1981-08-21

    The projects supported during the past year consist of: (a) collection of material from uranium miners known to have cancer of the lung into a tumor registry; (b) collection of interesting cases for second edition of the Manual on Pulmonary Cytology; (c) the regression study has been modified by computerization of re-reads of all cases which showed moderate atypical squamous cell metaplasia or higher since 1968; (d) continuation of sputum collection, and collection of lungs from deceased miners; (e) cooperation with fluorescent bronchoscopy development for localization of carcinoma in situ of the lung; (f) the immunological studies are presently funded by The Abbott Laboratories, but are closely associated with the lung cancer studies. Our findings suggest that patients developing lung cancer concomitantly develop immune suppression; and (g) a small plastic tube has been developed which will aid in the removal of cells from fiberoptic brushings. The plastic mold is presently being developed by Medi-Tech Corporation in Boston and the tube will be available in September 1981. Analysis of the incidence of small cell cancers of the lung over the last 30 years indicates that the incidence has dropped to 22% during 1975-1979 whereas it was 76.5% during the five year span from 1954-1959. General observations indicate that cigarette smoking is the most potent carcinogen, but that tumors are increased in miners who smoke. Moreover, the ultimate incidence of oat cell carcinoma results in earlier death than with other tumor types. The most commonly found tumor in the non-smoking miner is the small cell type.

  6. Characterization of uranium surfaces machined with aqueous propylene glycol-borax or perchloroethylene-mineral oil coolants

    SciTech Connect

    Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.; Richards, H.L.; Seals, R.D.; Byrd, V.R.

    1986-12-31

    The use of perchloroethylene (perc) as an ingredient in coolants for machining enriched uranium at the Oak Ridge Y-12 Plant has been discontinued because of environmental concerns. A new coolant was substituted in December 1985, which consists of an aqueous solution of propylene glycol with borax (sodium tetraborate) added as a nuclear poison and with a nitrite added as a corrosion inhibitor. Uranium surfaces machined using the two coolants were compared with respects to residual contamination, corrosion or corrosion potential, and with the aqueous propylene glycol-borax coolant was found to be better than that of enriched uranium machined with the perc-mineral oil coolant. The boron residues on the final-finished parts machined with the borax-containing coolant were not sufficient to cause problems in further processing. All evidence indicated that the enriched uranium surfaces machined with the borax-containing coolant will be as satisfactory as those machined with the perc coolant.

  7. Mortality from Circulatory System Diseases among French Uranium Miners: A Nested Case-Control Study.

    PubMed

    Drubay, Damien; Caër-Lorho, Sylvaine; Laroche, Pierre; Laurier, Dominique; Rage, Estelle

    2015-05-01

    A significant association has been observed between radon exposure and cerebrovascular disease (CeVD) mortality among French uranium miners, but risk factors for circulatory system diseases (CSD) have not been previously considered. We conducted new analyses in the recently updated (through 2007) French cohort of uranium miners (n = 5,086), which included 442 deaths from CSD, 167 of them from ischemic heart disease (IHD) and 105 from CeVD. A nested case-control study was then set up to collect and investigate the influence of these risk factors on the relationships between mortality from CSD and occupational external gamma ray and internal ionizing radiation exposure (radon and long-lived radionuclides) in this updated cohort. The nested case-control study included miners first employed after 1955, still employed in 1976 and followed up through 2007. Individual information about CSD risk factors was collected from medical files for the 76 deaths from CSD (including 26 from IHD and 16 from CeVD) and 237 miners who had not died of CSD by the end of follow-up. The exposure-risk relationships were assessed with a Cox proportional hazard model weighted by the inverse sampling probability. A significant increase in all CSD and CeVD mortality risks associated with radon exposure was observed in the total cohort [hazard ratios: HRCSD/100 working level months (WLM) = 1.11, 95% confidence interval (1.01; 1.22) and HRCeVD/100 WLM = 1.25 (1.09; 1.43), respectively]. A nonsignificant exposure-risk relationship was observed for every type of cumulative ionizing radiation exposure and every end point [e.g., HRCSD/100WLM = 1.43 (0.71; 2.87)]. The adjustment for each CSD risk factor did not substantially change the exposure-risk relationships. When the model was adjusted for overweight, hypertension, diabetes, hypercholesterolemia and smoking status, the HR/100WLM for CSD, for example, was equal to 1.21 (0.54; 2.75); and when it was adjusted for risk factors selected with the

  8. Quantitative relationship between silica exposure and lung cancer mortality in German uranium miners, 1946–2003

    PubMed Central

    Sogl, M; Taeger, D; Pallapies, D; Brüning, T; Dufey, F; Schnelzer, M; Straif, K; Walsh, L; Kreuzer, M

    2012-01-01

    Background: In 1996 and 2009, the International Agency for Research on Cancer classified silica as carcinogenic to humans. The exposure–response relationship between silica and lung cancer risk, however, is still debated. Data from the German uranium miner cohort study were used to further investigate this relationship. Methods: The cohort includes 58 677 workers with individual information on occupational exposure to crystalline silica in mg m−3-years and the potential confounders radon and arsenic based on a detailed job-exposure matrix. In the follow-up period 1946–2003, 2995 miners died from lung cancer. Internal Poisson regression with stratification by age and calendar year was used to estimate the excess relative risk (ERR) per dust-year. Several models including linear, linear quadratic and spline functions were applied. Detailed adjustment for cumulative radon and arsenic exposure was performed. Results: A piecewise linear spline function with a knot at 10 mg m−3-years provided the best model fit. After full adjustment for radon and arsenic no increase in risk <10 mg m−3-years was observed. Fixing the parameter estimate of the ERR in this range at 0 provided the best model fit with an ERR of 0.061 (95% confidence interval: 0.039, 0.083) >10 mg m−3-years. Conclusion: The study confirms a positive exposure–response relationship between silica and lung cancer, particularly for high exposures. PMID:22929885

  9. Iron disulfide minerals and the genesis of roll-type uranium deposits

    SciTech Connect

    Reynolds, R.L.; Goldhaber, M.B.

    1983-01-01

    Iron disulfide (FeS/sub 2/) minerals in host rocks for roll-type uranium deposits that contain fossil vegetal (organic) matter differ in abundance, distribution, texture, and sulfur isotopic ratios from FeS/sub 2/ minerals in host rocks for deposits that do not contain fossil vegetal matter. In three south Texas deposits lacking such organic matter, preore FeS/sub 2/ is dominantly euhedral pyrite. This preore pyrite formed in close proximity to fault zones in response to solutions emanating from these faults. In these deposits, ore-stage FeS/sub 2/ is dominantly marcasite that occurs as overgrowths on preore pyrite in the ore zone and as far as 400 m downdip from the altered tongue. In three deposits (two in Wyoming and one in Texas) that contain organic matter, preore FeS/sub 2/ is also dominantly pyrite, but it occurs commonly as framboids and as replacements of plant fragments. This preore pyrite formed by bacterial sulfate reduction during early diagenesis and may be isotopically distinct from pyrite formed from fault-related fluids. Orestage FeS/sub 2/ in these deposits is primarily pyrite. Geochemical conditions favoring pyrite formation (such as bacterial control on pH and sulfur speciation) suggest that bacterial sulfate reduction provided sulfide for ore-stage pyrite in deposits which contain organic matter. In contrast, abiologic sulfur transformations (involving elemental sulfur or metastable sulfur oxyanions) tend to produce ore-stage marcasite in deposits that do not contain organic matter. The contrasting origins of ore-stage FeS/sub 2/ minerals in host rocks with and without organic matter are consistent with previously proposed biogenic and nonbiogenic theories for the origin of roll-type deposits.

  10. Minerals

    MedlinePlus

    Minerals are important for your body to stay healthy. Your body uses minerals for many different jobs, including building bones, making ... regulating your heartbeat. There are two kinds of minerals: macrominerals and trace minerals. Macrominerals are minerals your ...

  11. The chemical evolution and paragenesis of uranium minerals from the ruggles and palermo granitic pegmatites, New Hampshire

    USGS Publications Warehouse

    Korzeb, S.L.; Foord, E.E.; Lichte, F.E.

    1997-01-01

    A study of the chemical evolution and paragenesis of the uranium minerals at the Palermo No. 1 and Ruggles granitic pegmatites, Grafton County, New Hampshire, revealed four stages of secondary mineralization. A total of eight uranium minerals were identified in the four stages. The first stage is a mixture of uranyl oxide hydroxide-hydrates represented by mineral "A", which surrounds and replaces a uraninite core. The second stage is a carbonate stage found only at the Palermo No. 1 pegmatite, and is represented by rutherfordine. The third stage is represented by uranyl silicates. At the Palermo No. 1 pegmatite, this stage consists of ??-uranophane, and at the Ruggles pegmatite, it consists of soddyite and ??-uranophane. A final fourth stage is a phosphate stage represented by phosphuranylite and meta-autunite I. The first three stages of mineralization developed from hydrothermal and meteoric processes. With dropping temperatures, hydrothermal fluids reached meteoric temperatures and acquired the characteristics of meteoric water. The pH shifted from acidic (pH less than about 6 at 100??C) to alkaline (pH > 7 at 25??C). Since mineral "A" contains hydroxyl and a low amount of molecular water, it probably formed at a temperature greater than 100??C in the acidic environment. After the first stage, the hydrothermal fluids likely reached the temperatures of meteoric water. The initial pH of the meteoric water was acidic (pH less than about 6 at 25??C) and then slowly shifted to alkaline. The mineralizing fluids became oversaturated in CO3, Ca, K, and Si. Uraninite and mineral "A" became unstable and were replaced by rutherfordine and uranyl silicates. The fourth or phosphate stage developed from the introduction of groundwater. The uranyl phosphate minerals precipitated from an acidic fluid (pH < 7 at 25??C) that was oversaturated with Ca, K, U, and P.

  12. Mortality of a cohort of French uranium miners exposed to relatively low radon concentrations.

    PubMed

    Tirmarche, M; Raphalen, A; Allin, F; Chameaud, J; Bredon, P

    1993-05-01

    A cohort mortality study has been performed on French uranium miners having experienced more than 2 years of underground mining, with first radon exposure between 1946 and 1972. Vital status has been ascertained from the date of entry to the 31 December 1985 for 99% of the members of this cohort; causes of death are identified for 95.5% of the decedents. The different causes of death are compared to the age specific national death rates by indirect standardisation and expressed by standardised mortality ratios (SMR). A statistically significant excess has been observed for lung and laryngeal cancer deaths. The Poisson trend test shows a statistically significant trend for the risk of lung cancer death as a function of cumulative radon exposure, assuming a lag time of 5 years; for laryngeal cancer no significant trend has been observed. Poisson regression modelling has been applied to the following exposure groups: < 10 WLM (Working Level Month); 10-49 WLM; 50-149 WLM; 150-299 WLM; > or = 300 WLM; it indicates an increase in the SMR for lung cancer of 0.6% per WLM (standard error: 0.4%) with an estimated intercept at 0 WLM of 1.68 (standard error: 0.4). The distinction of two working periods, differing by their annual radon concentration (before/since 1956) does not modify this exposure-response relationship. This coefficient of risk per unit of exposure is lower than in most of the other uranium miners' studies but it lies in the range of the evaluation of the ICRP 50 committee and the 'BEIR IV' report of the U.S. National Academy of Science. It is observed in a cohort having experienced low cumulative exposure to radon (mean: 70 WLM) spread over a mean duration of 14.5 years. Even though occupational exposure in mines differs in several particulars from domestic exposure, this study presents characteristics of low annual exposure comparable to radon gas concentrations in houses of 500-1000 Bq.m-3, and will contribute to the evaluation of cancer risk for the public

  13. Age of uranium mineralization at the Jabiluka and Ranger deposits, Northern Territory, Australia: New U- Pb isotope evidence.

    USGS Publications Warehouse

    Ludwig, K. R.; Grauch, R.I.; Nutt, C.J.; Nash, J.T.; Frishman, D.; Simmons, K.R.

    1987-01-01

    The Ranger and Jabiluka uranium deposits are the largest in the Alligator Rivers uranium field, which contains at least 20% of the world's low-cost uranium reserves. Ore occurs in early Proterozoic metasediments, below an unconformity with sandstones of the 1.65 b.y.-old Kombolgie Formation. This study has used U-Pb isotope data from a large number of whole-rock drill core samples with a variety of mineral assemblages and textures. Both Ranger and Jabiluka reflect a common, profound isotopic disturbance at about 400 to 600 m.y. This disturbance, which was especially pronounced at Jabiluka, may correspond to the development of basins and associated basalt flows to the W and SW.-from Authors

  14. Remote Sensing Detecting for Hydrocarbon Microseepage and Relationship with the Uranium Mineralization in Dongsheng Area, Ordos Basin, China

    NASA Astrophysics Data System (ADS)

    Zhu, M.; Liu, D.; Gao, Y.

    2005-12-01

    The Ordos Basin is located at the central area of northern China with an area of about 250,000 km2. It is well known "a basin of energy resources" of China for its large reserves of coal, oil and gas. A large-scale sandstone-type uranium metallogenic belt has been found recently in Zhiluo Formation of middle Jurassic in Dongsheng area in the northeastern part of the basin. The ore-forming mechanism remains unsolved so far. There is a hypothesis that the uranium precipitation was related to a hydrocarbon migration from the central basin. In order to explore the evidences of ever existed hydrocarbon microseepage and migration in this area, several indices such as the Iron Oxide Index, Ferrous Index, Clay Mineral Index, Mineral Composite Index, and Ferrous Transfer Percentage Index have been derived. Thorium Normalization of aeroradiometric data and fusion of aeroradiometric and TM data have been carried out as well. Therefore, the subaerial oxide and reduced area, uranium outmigrated and immigrated area, and ancient recharge and discharge of groundwater are thus delineated. As a result, two hydrocarbon microseepage belts in Dongsheng area have been extracted by combining the methods mentioned above. One is in the northern of Dongsheng along a nearly east-westward fault zone and the other one is in the southern of Dongsheng uranium mineralization belt along a nearly northwestward fault zone. The study suggests that the subaerial reduced area was related to hydrocarbon microseepage and the hydrocarbon migration along the fault and fracture zone or penetrable strata played an important role for uranium deposition in Zhiluo Formation near the northwestward fault zone.

  15. A study to verify a reported excess of chromosomal aberrations in blood lymphocytes of Namibian uranium miners.

    PubMed

    Lloyd, D C; Lucas, J N; Edwards, A A; Deng, W; Valente, E; Hone, P A; Moquet, J E

    2001-06-01

    This report describes a study to verify an earlier report of excess chromosomal damage in the blood lymphocytes of uranium miners. Coded blood samples from 10 miners and 10 controls were analyzed conventionally for unstable aberrations and by FISH for translocations. Conventional analysis, scoring 1000 metaphases per subject, showed no significant difference between miners and controls in the frequencies of chromosome- and chromatid-type aberrations. Investigators at two laboratories undertook FISH analyses, each scoring 4000 metaphases per subject. When the data from each laboratory were examined separately, one found slightly more translocations in the miners while the other found fewer. In neither case was the difference significant at the 95% level of confidence. Combining the data likewise showed no significant excess of damage in the miners. This applied to simple one- and two-way translocations and to cells with complex exchanges. There was no correlation between levels of translocations and total lifetime doses from occupational and/or background irradiation. A borderline significant excess of rogue cells was found in the miners. This may be a chance observation, as these rare, highly abnormal cells are considered to be unrelated to radiation exposure and are probably due to a virus. The overall conclusion is that the frequency of chromosomal damage in the miners did not exceed that in the controls. Therefore, the result of the earlier study was not confirmed. PMID:11352763

  16. Annotated bibliography of environmentally relevant investigations of uranium mining and milling in the Grants Mineral Belt, northwestern New Mexico

    USGS Publications Warehouse

    Otton, James K.

    2011-01-01

    Studies of the natural environment in the Grants Mineral Belt in northwestern New Mexico have been conducted since the 1930s; however, few such investigations predate uranium mining and milling operations, which began in the early 1950s. This report provides an annotated bibliography of reports that describe the hydrology and geochemistry of groundwaters and surface waters and the geochemistry of soils and sediments in the Grants Mineral Belt and contiguous areas. The reports referenced and discussed provide a large volume of information about the environmental conditions in the area after mining started. Data presented in many of these studies, if evaluated carefully, may provide much basic information about the baseline conditions that existed over large parts of the Grants Mineral Belt prior to mining. Other data may provide information that can direct new work in efforts to discriminate between baseline conditions and the effects of the mining and milling on the natural environment.

  17. Radiation dose dependent risk of liver cancer mortality in the German uranium miners cohort 1946-2003.

    PubMed

    Dufey, F; Walsh, L; Sogl, M; Tschense, A; Schnelzer, M; Kreuzer, M

    2013-03-01

    An increased risk of mortality from primary liver cancers among uranium miners has been observed in various studies. An analysis of the data from a German uranium miner cohort (the 'Wismut cohort') was used to assess the relationship with ionising radiation. To that end the absorbed organ dose due to high and low linear energy transfer radiation was calculated for 58 987 miners with complete information on radiation exposure from a detailed job-exposure matrix. 159 deaths from liver cancer were observed in the follow-up period from 1946 to 2003. Relative risk models with either linear or categorical dependence on high and low linear energy transfer radiation liver doses were fitted by Poisson regression, stratified on age and calendar year. The linear trend of excess relative risk in a model with both low and high linear transfer radiation is -0.8 (95% confidence interval (CI): -3.7, 2.1) Gy(-1) and 48.3 (95% CI: -32.0, 128.6) Gy(-1) for low and high linear energy transfer radiation, respectively, and thus not statistically significant for either dose. The increase of excess relative risk with equivalent liver dose is 0.57 (95% CI: -0.69, 1.82) Sv(-1). Adjustment for arsenic only had a negligible effect on the radiation risk. In conclusion, there is only weak evidence for an increase of liver cancer mortality with increasing radiation dose in the German uranium miners cohort considered. However, both a lack of statistical power and potential misclassification of primary liver cancer are issues. PMID:23295324

  18. Association between lymph node silicosis and lung silicosis in 4,384 German uranium miners with lung cancer.

    PubMed

    Taeger, Dirk; Brüning, Thomas; Pesch, Beate; Müller, Klaus-Michael; Wiethege, Thorsten; Johnen, Georg; Wesch, Horst; Dahmann, Dirk; Hoffmann, Wolfgang

    2011-01-01

    This study investigates the association between lymph node-only and lung silicosis in uranium miners with lung cancer and exposure to quartz dust. Tissue slides of 4,384 German uranium miners with lung cancer were retrieved from an autopsy archive and reviewed by 3 pathologists regarding silicosis in the lungs and lymph nodes. Cumulative exposure to quartz dust was assessed with a quantitative job-exposure matrix. The occurrence of silicosis by site was investigated with regression models for exposure to quartz dust. Miners with lung silicosis had highest cumulative quartz exposure, followed by lymph node-only silicosis and no silicosis. At a cumulative quartz exposure of 40 mg/m(3) × years, the probability of lung silicosis was above 90% and the likelihood of lymph node-only silicosis and no silicosis do not differ anymore. The results support that lymph node silicosis can precede lung silicosis, at least in a proportion of subjects developing silicosis, and that lung silicosis strongly depends on the cumulative quartz dose. PMID:21337184

  19. Influence of mineral colloids and humic substances on uranium(VI) transport in water-saturated geologic porous media.

    PubMed

    Wang, Qing; Cheng, Tao; Wu, Yang

    2014-12-01

    Mineral colloids and humic substances often co-exist in subsurface environment and substantially influence uranium (U) transport. However, the combined effects of mineral colloids and humic substances on U transport are not clear. This study is aimed at quantifying U transport and elucidating geochemical processes that control U transport when both mineral colloids and humic acid (HA) are present. U-spiked solutions/suspensions were injected into water-saturated sand columns, and U and colloid concentrations in column effluent were monitored. We found that HA promoted U transport via (i) formation of aqueous U-HA complexes, and (ii) competition against aqueous U for surface sites on transport media. Illite colloids had no influence on U transport at pH5 in the absence of HA due to low mobility of the colloids. At pH9, U desorbed from mobile illite and the presence of illite decreased U transport. At pH5, high U transport occurred when both illite colloids and HA were present, which was attributed to enhanced U adsorption to illite colloids via formation of ternary illite-HA-U surface complexes, and enhanced illite transport due to HA attachment to illite and transport media. This study demonstrates that the combined effects of mineral colloids and HA on contaminant transport is different from simple addition of the individual effect. PMID:25444118

  20. Relationship of radioactive radon daughters and cigarette smoking in the genesis of lung cancer in uranium miners

    SciTech Connect

    Saccomanno, G.; Huth, G.C.; Auerbach, O.; Kuschner, M.

    1988-10-01

    This article documents the study of 383 cases of lung cancer in uranium miners and presents for the first time the relationship of radioactive radon gas and cigarette smoking. There is evidence that alpha radiation from radon gas at exposure levels above 465 working level months (WLM) is a strong contributor to the development of lung cancer. Cigarette smoking plays the most significant role in causing lung tumor; this is also noticed in nonminers who smoke cigarettes. A synergistic or additive effect of these two carcinogens is strongly suggested. The data indicate that small cell tumors develop in younger nonsmoking miners exposed to radon levels above 465 WLM. Lung cancers develop in smoking miners at lower levels of radon exposure than in nonsmoking miners. Based on an average mining experience of 15 years, there is substantial evidence that the present maximum allowable limit of 0.3 working levels (WL), or 4 working level months (WLM) per year, is safe, representing a margin of safety of approximately 10:1. Furthermore, a comparison of these data with the radon levels in some homes, averaging in the neighborhood of 0.025 WL, would indicate that health risks at these levels are negligible. It is suggested that 20 picocuries/liter, which equals 0.10 WL, be the maximum allowable level in homes.

  1. Potential precious and strategic metals as by-products of uranium mineralized breccia pipes in northern Arizona

    SciTech Connect

    Wenrich, K.J.; Silberman, M.L.

    1984-07-01

    The development of caves within the Mississippian Redwall Limestone, accompanied by later upward stoping of overlying Paleozoic and Triassic rock, resulted in the formation of breccia pipes. Despite the depressed uranium market, some of these pipes are presently being mined for uranium. No brecciated rock within pipes has been observed above its normal stratigraphic position, nor is any volcanic rock associated in space or time with these pipes. Mineralized rock transects any strata from the Redwall Limestone to the Triassic Chinle Formation. Over 400 collapse structures, believed to represent breccia pipes (many with exposed breccia), have been mapped. Those with gamma radiation exceeding 2.5 times background (57 pipes) have been sampled (155 samples). Of these oxidized surface samples collected solely on the basis of radioactivity, 30% have Ag exceeding 10 ppm, some with up to 1150 ppm. Two samples of brecciated, oxidized sandstone with radioactivity exceeding 20 and 40 times background from this adit, and another sample of hematite-, malachite-, and chalcocite-impregnated sandstone from a higher level adit contained high concentrations of Au, Hg, Cd, and W, along with many elements commonly anomalous in mineralized breccia pipes from northern Arizona: Ag, As, Co, Cu, Mo, Ni, and Pb. The potential for economic recovery from breccia pipes of elements other than U, such as Ag, Au, Co, and Ni, should not be ignored as their concentrations are even more enhanced in unoxidized samples.

  2. Uranium and thorium behavior in groundwater of the natural spa area “Choygan mineral water” (East Tuva)

    NASA Astrophysics Data System (ADS)

    Kopylova, Y.; Guseva, N.; Shestakova, A.; Khvaschevskaya, A.; Arakchaa, K.

    2015-11-01

    The natural spa area “Choygan mineral waters”, a unique deposit of natural carbon dioxide mineral waters in Siberia, is located in the Eastern Sayan Mountains. There are 33 spring discharges in this area. Spring waters are mainly of HCO3-Na-Ca type. TDS varies from 300 mg/L to 2600 mg/L, the temperature ranges from 7 °C (in spring 33) to 39 °C (in spring 12), pH varies from 5.9 to 8.3, and the value of the oxidation-reduction potential is from -170 mV to 236 mV. All studied waters were divided into two groups according to their temperature and geochemical conditions: cold fresh water in oxidizing environment and warm slightly brackish water in reducing environment. The uranium concentration varies from 0.7 to 14 μg/l and the thorium concentration varies from 0.001 to 0.33 μg/l in the studied waters. The predominant uranium complexes are (UO2(CO3)3)4-, (UO2(CO3)2)2-, UO2CO3, (UO2(PO4)2)4- in the waters in oxidizing and reducing environments. It was found that acid-alkaline and oxidizing-reducing conditions were the determining factors for uranium behavior and speciation in the studied waters. The pH conditions are determining factors for thorium behavior and speciation in the studied waters. In slightly acidic water the predominant thorium species is negatively charge complex (ThCO3(OH)3)- (more than 95%).

  3. Minerals

    Technology Transfer Automated Retrieval System (TEKTRAN)

    Fish require the same minerals or inorganic elements as terrestrial animals for tissue formation, osmoregulation and various metabolic functions. Those required in large quantities are termed macro- or major minerals and those required in small quantities are called micro- or trace minerals. Fish ca...

  4. Groundwater prospecting for sandstone-type uranium deposits: the merits of mineral-solution equilibria versus single element tracer methods. Volume II

    SciTech Connect

    Wanty, R.B.; Langmuir, D.; Chatham, J.R.

    1981-08-01

    This report presents the results of further research on the groundwater geochemistry of 96 well waters in two uraniferous aquifers in Texas and Wyoming, and is a continuation of the work presented by Chatham et al. (1981). In this study variations in concentrations of U, As, Mo, Se and V were compared with the saturation state of the groundwater with respect to mineral phases of these elements known or expected to occur in each area. The non-radiogenic trace elements exhibited strong redox dependence consistent with thermodynamic predictions, but their variations did not pinpoint existing uranium ore bodies, because of a shift in groundwater flow patterns since the time of ore emplacement. Saturation levels of trace element minerals such as realgar, native Se, and molybdenite showed broad anomalies around the ore-bearing areas, similar to patterns found for U minerals by Langmuir and Chatham (1980), and Chatham et al. (1981). The radiogenic elements Ra and Rn showed significant anomalies directly within the ore zones. Helium anomalies were displaced in the direction of groundwater flow, but by their magnitude and areal extent provided strong evidence for the existence of nearby uranium accumulations. Uranium isotope ratios showed no systematic variations within the two aquifers studied. Saturation maps for kaolinite, illite, montmorillonite and the zeolites analcime and clinoptilolite provided 1 to 2 km anomalies around the ore at the Texas site. Saturation values for the gangue minerals pyrite and calcite defined the redox interface and often suggested the position of probable uranium mineralization. When properly used, the groundwater geochemical concepts for exploration can accurately pinpoint uranium mineralization at a fraction of the cost of conventional methods that involve test drilling and geophysical and core logging.

  5. Enhancement of lung cancer by cigarette smoking in uranium and other miners

    SciTech Connect

    Archer, V.E.

    1985-01-01

    There are substantial animal and epidemiological data related to cigarette smoking and lung cancer among miners exposed to elevated levels of radon daughters that appears to be in disagreement. An hypothesis is advanced that explains most of this disagreement as being derived from temporal differences of cancer expression. The hypothesis is that a given radiation exposure induced a finite number of lung cancers, which have shorter latent periods due to the cancer promotion activity of smoke among cigarette smokers. According to this hypothesis, the life-shortening effect is greater among smoking miners than nonsmoking miners, and the ultimate number of lung cancers among smoking miners will be only a little larger than among nonsmokers. The greater number will derive from the additive effect of radiation and smoking, plus the greater force of competing causes of death among elderly nonsmokers.

  6. The Schwartzwalder uranium deposit. I: Geology and structural controls on mineralization.

    USGS Publications Warehouse

    Wallace, A.R.; Karlson, R.C.

    1985-01-01

    Numerous uranium veins occupy fractures and faults in brittle Proterozoic gneisses along the east central Front Range of Colorado. The deposit size correlates with the density and localization of brittle fracture. The largest deposit, the Schwartzwalder, is explained by a singular configuration of complexly broken, deep-reaching brittle gneisses between impervious schists. The gneisses are described as being derived from volcanic rocks, shales, and chemical sediments, including iron, quartz and sulphide formations.-G.J.N.

  7. Thermodynamic modeling of the behavior of Uranium and Arsenic in mineralized Shaazgai-Nuur Lake (Northwest Mongolia)

    NASA Astrophysics Data System (ADS)

    Gaskova, O. L.; Isupov, V. P.; Vladimirov, A. G.; Shvartsev, S. L.; Kolpakova, M. N.

    2015-11-01

    Highly mineralized closed lakes on the territory of ore regions of Mongolia are of special interest in relation to the search for nonconventional sources of metals. Water of soda Shaazgai-Nuur Lake contains ~1 mg/L U, and the content of the undesirable admixture of As is up to 300 μg/L. Uranium and Arsenic speciation in solution and in the bottom sediments of the lake was estimated using thermodynamic modeling, and a method of their separation was suggested. Calculation of the models of sorption of these elements by goethite and calcite showed that at pH 9.4 typical of natural water it could be effective only at a high concentration of FeOOH sorbent. In this case, at pH <5 and >8 (the area of U sorption), As may be removed by simple filtering of solutions from the suspension upon additional coagulation.

  8. Development of advanced methods for early detection of lung cancer in the uranium miner/worker population

    SciTech Connect

    Profio, A.E.; Balchum, O.J.; Saccomanno, G.; Huth, G.C.

    1983-01-01

    Fluorescence bronchoscopy with a violet laser and image intensifier has been developed for imaging the red fluorescence of a tumor-specific agent, hematoporphyrin derivative, that has been injected before the examination. The instrument was developed to localize carcinoma in situ and early, small bronchogenic tumors diagnosed by sputum cytology but invisible on chest x-ray and conventional bronchoscopy, in underground uranium miners and others at risk for lung cancer. In addition to the imaging devices, a video system including a processor and electronics for digital background image subtraction has been developed to enhance contrast. A ratio fluorometer and a rapid-scan spectrum analyzer have been designed for quantitative measurements of fluorescence intensity and dependence on dosage and time after injection of the fluorescent agent. Clinical trials demonstrate detection of carcinoma in situ, and the true positive rate should be improved by the new instrumentation and optimization of time delay and dosage. 14 references, 6 figures.

  9. Correcting for exposure measurement error in a reanalysis of lung cancer mortality for the Colorado Plateau Uranium Miners cohort.

    PubMed

    Stram, D O; Langholz, B; Huberman, M; Thomas, D C

    1999-09-01

    The exposure estimates used to date for the analysis of lung cancer mortality in the Colorado Plateau Uranium Miners cohort were developed from radon progeny measurements taken in mines beginning in 1951. Since uranium miners were often exposed over long periods of time and since mines were not continuously monitored, much extrapolation and/or interpolation of measured dose-rates was needed in order to develop estimates of exposure for each of the miners in the cohort. We have recently re-examined the interpolation scheme used to create the histories in the light of the fit of a statistical model for the radon progeny measurements taken in mines within the Plateau, and we have computed revised exposure estimates for the large majority of miners in the cohort. This report describes the use of these new model-based revised exposure estimates in the analysis of lung cancer mortality, using follow-up data current through 1990. Specific issues addressed here are (1) the strength of the association between exposure and risk of lung cancer mortality; (2) effects of attained age and time since exposure upon risk of lung cancer mortality; and (3) exposure-rate effects upon risk. Results using the revised exposure estimates are compared to those obtained fitting the same models using the original Public Health Service (PHS) exposure estimates. We found evidence that the new exposure histories provide a better fit to the lung cancer mortality data than do the histories based upon the original PHS dose-rate estimates. In general, the new results show a stronger overall relationship (larger slope estimate) between lung cancer mortality and exposure per unit exposure compared to those obtained with the original estimates, while displaying similar age at exposure and time since exposure effects. In the reanalysis the impact of low dose-rate exposure is found to be relatively unchanged before and after exposure error correction, while the estimate of the effect of high dose

  10. Biologically based analysis of the data for the Colorado uranium miners cohort: age, dose and dose-rate effects.

    PubMed

    Luebeck, E G; Heidenreich, W F; Hazelton, W D; Paretzke, H G; Moolgavkar, S H

    1999-10-01

    This study is a comprehensive analysis of the latest follow-up of the Colorado uranium miners cohort using the two-stage clonal expansion model with particular emphasis on effects related to age and exposure. The model provides a framework in which the hazard function for lung cancer mortality incorporates detailed information on exposure to radon and radon progeny from hard rock and uranium mining together with information on cigarette smoking. Even though the effect of smoking on lung cancer risk is explicitly modeled, a significant birth cohort effect is found which shows a linear increase in the baseline lung cancer risk with birth year of the miners in the cohort. The analysis based on the two-stage clonal expansion model suggests that exposure to radon affects both the rate of initiation of intermediate cells in the pathway to cancer and the rate of proliferation of intermediate cells. However, in contrast to the promotional effect of radon, which is highly significant, the effect of radon on the rate of initiation is found to be not significant. The model is also used to study the inverse dose-rate effect. This effect is evident for radon exposures typical for mines but is predicted to be attenuated, and for longer exposures even reversed, for the more protracted and lower radon exposures in homes. The model also predicts the drop in risk with time after exposure ceases. For residential exposures, lung cancer risks are compared with the estimates from the BEIR VI report. While the risk estimates are in agreement with those derived from residential studies, they are about two- to fourfold lower than those reported in the BEIR VI report. PMID:10477911

  11. Comparison of abundances of chemical elements in mineralized and unmineralized sandstone of the Brushy Basin Member of the Morrison Formation, Smith Lake District, Grants uranium region, New Mexico

    USGS Publications Warehouse

    Pierson, C.T.; Spirakis, C.S.; Robertson, J.F.

    1983-01-01

    Statistical treatment of analytical data from the Mariano Lake and Ruby uranium deposits in the Smith Lake district, New Mexico, indicates that organic carbon, arsenic, barium, calcium, cobalt, copper, gallium, iron, lead, manganese, molybdenum, nickel, selenium, strontium, sulfur, vanadium, yttrium, and zirconium are concentrated along with uranium in primary ore. Comparison of the Smith Lake data with information from other primary deposits in the Grants uranium region and elsewhere in the Morrison Formation of the Colorado Plateau suggests that these elements, with the possible exceptions of zirconium and gallium and with the probable addition of aluminum and magnesium, are typically associated with primary, tabular uranium deposits. Chemical differences between the Ruby and Mariano Lake deposits are consistent with the interpretation that the Ruby deposit has been more affected by post-mineralization oxidizing solutions than has the Mariano Lake deposit.

  12. Minerals

    MedlinePlus

    ... your body needs in larger amounts. They include calcium, phosphorus, magnesium, sodium, potassium, chloride and sulfur. Your body needs just small amounts of trace minerals. These include iron, manganese, copper, iodine, zinc, cobalt, fluoride and selenium. The best way to ...

  13. Radon, cigarette smoke, and lung cancer: A re-analysis of the Colorado Plateau uranium miners' data [see comments

    SciTech Connect

    Moolgavkar, S.H.; Luebeck, E.G.; Krewski, D.; Zielinski, J.M. )

    1993-05-01

    Much of our knowledge regarding the interaction of radon and tobacco smoke in the etiology of human lung cancer derives from studies of uranium miners. In this article, we present a re-analysis of lung cancer mortality in the Colorado Plateau miners' cohort within the framework of the two-mutation clonal expansion model of carcinogenesis. This analysis takes into account the patterns of exposure to radon and cigarette smoke experienced by individuals in the cohort. A simultaneous re-analysis of the British doctors' cohort indicated that those model parameters relating to the effects of tobacco were comparable in the two data sets. We found no evidence of interaction between radon and tobacco smoke with respect to their joint effect on the first or second stage mutation rates or on the rate of proliferation of initiated cells. The age-specific relative risks associated with joint exposure to radon and cigarette smoke, however, were supra-additive but submultiplicative. The analysis also confirmed that fractionation of radon exposures leads to higher lung cancer risks. Finally, we present some estimates of lung cancer risk from environmental radon exposure for non-smokers and smokers.

  14. Iron disulfide minerals and the genesis of roll-type uranium deposits.

    USGS Publications Warehouse

    Reynolds, R.L.; Goldhaber, M.B.

    1983-01-01

    Studies of the distribution of and textural relationships among pyrite and marcasite in host rocks for a number of roll-type sedimentary U deposits have enabled identification of several generations of FeS2 minerals. A critical factor influencing mineral formation is the complex relationship of pH and the S species that are precursors of FeS2 minerals. The presence or absence of intrinsic organic matter for bacterial sulphate reduction also plays a key role. In deposits lacking such organic matter, the pre-ore is often euhedral pyrite and the ore-stage is marcasite. In contrast, in deposits containing organic matter the pre-ore is pyrite occurring as framboids or as replacements of plant material, and the ore-stage is also pyrite. These contrasting FeS2 assemblages and their respective modes of origin are consistent with previously proposed biogenic and nonbiogenic theories of the genesis of roll-type U deposits. -J.E.S.

  15. A review of the results from the German Wismut uranium miners cohort.

    PubMed

    Walsh, L; Grosche, B; Schnelzer, M; Tschense, A; Sogl, M; Kreuzer, M

    2015-04-01

    The Wismut cohort is currently the largest single study on the health risks associated with occupational exposures to ionising radiation and dust accrued during activities related to uranium mining. The cohort has ∼59 000 male workers, first employed between 1946 and 1989, at the Wismut Company in Germany. The main effect is a statistically significant increase in mortality from lung cancer with both increasing cumulative radon exposure and silica dust exposure. Risks for cancers of the extrathoracic airways, all extra-pulmonary cancers and cardiovascular diseases associated with radiation exposures have been evaluated. Cohort mortality rates for some other cancer sites, stomach and liver, are statistically significantly increased in relation to the general population, but not statistically significantly related to occupational exposures. No associations between leukaemia mortality and occupational doses of ionising radiation were found. PMID:25267854

  16. Mineral resource assessment of rare-earth elements, thorium, titanium, and uranium in the Greenville 1 degree by 2 degrees Quadrangle, South Carolina, Georgia, and North Carolina

    USGS Publications Warehouse

    Lesure, Frank G.; Curtin, Gary C.; Daniels, David L.; Jackson, John C.

    1993-01-01

    Mineral resources of the Greenville 1° x 2° quadrangle, South Carolina, Georgia, and North Carolina, were assessed between 1984 and 1990 under the Conterminuous United States Mineral Assessment Program (CUSMAP) of the U.S. Geological Survey (USGS). The mineral resource assessments were made on the basis of geologic, geochemical, and geophysical investigations and the presence of mines, prospects, and mineral occurrences from the literature. This report is an assessment of the rare-earth elements (REE), thorium, titanium, and uranium resources in the Greenville quadrangle and is based on heavy mineral concentrates collected in 1951-54 by the USGS (Overstreet and others, 1968; Caldwell and White, 1973; Cuppels and White, 1973); on the results of the U.S. Department of Energy, National Uranium Resource Evaluation (NURE) sampling program (Ferguson, 1978, 1979); on analyses of stream-sediment and heavy-mineral-concentrate samples (Jackson and Moore, 1992, G.C Cullin, USGS, unpub. data, 1992) on maps showing aerial gamma radiation in the Greenville quadrangle (D.L. Daniels, USGS, unpub. data, 1992); and on the geology as mapped by Nelson and others (1987, 1989).

  17. Investigation of Great Basin big sagebrush and black greasewood as biogeochemical indicators of uranium mineralization. Final report. National Uranium Resource Evaluation

    SciTech Connect

    Diebold, F.E.; McGrath, S.

    1982-11-01

    The effects of varying phosphate concentrations in natural aqueous systems upon the uptake of uranium by big sagebrush (Artemesia tridentata subsp. tridentata) and black greasewood (Sarcobatus vermiculatus (Hook) Torr.) were investigated. Two separate growth experiments with five drip-flow hyroponic units were used and plant seedlings were grown for 60 days in solutions of varying phosphate and uranium concentrations. Successful growth experiments were obtained only for big sagebrush; black greasewood did not sustain sufficient growth. The phosphate concentration of the water did affect the uptake of uranium by the big sagebrush, and this effect is most pronounced in the region of higher concentrations of uranium in the water. The ratio of the concentration of uranium in the plant to that in the water was observed to decrease with increasing uranium concentration in solution. This is indicative of an absorption barrier in the plants. The field data shows that big sagebrush responds to uranium concentrations in the soil water and not the groundwater. The manifestation of these results is that the use of big sagebrush as a biogeochemical indicator of uranium is not recommended. Since the concentration of phosphate must also be knwon in the water supplying the uranium to the plant, one should analyze this natural aqueous phase as a hydrochemical indicator rather than the big sagebrush.

  18. Uranium isotopic distribution in the mineral phases of granitic fracture fillings by a sequential extraction procedure.

    PubMed

    Crespo, M T; Pérez del Villar, L; Jiménez, A; Pelayo, M; Quejido, A; Sánchez, M

    1996-01-01

    In order to study the recent rock-water interaction processes in the E1 Berrocal site, a sequential leaching method has been applied to granitic fracture fillings to obtain the U isotopic distribution in the mineral phases of these samples. Based on the mineralogical composition of these materials, six dissolution steps have been chosen to extract U as exchangeable cation, from carbonates, amorphous Fe-oxyhydroxides, labile resistates and highly insoluble resistates. In this way, the processes involved in the rock-water interaction phenomena, mainly dissolution, precipitation, coprecipitation and adsorption can be distinguished and even approximately dated. PMID:8976044

  19. Cooling pattern and mineralization history of the Saint Sylvestre and western Marche leucogranite pluton, French Massif Central: II. Thermal modelling and implications for the mechanisms of uranium mineralization

    NASA Astrophysics Data System (ADS)

    Scaillet, S.; Cuney, M.; le Carlier de Veslud, C.; Cheilletz, A.; Royer, J. J.

    1996-12-01

    A two-dimensional (2-D) thermal modelling of the Saint Sylvestre - western Marche leucogranite complex (northwestern Limousin, French Massif Central, FMC) was conducted to help constrain the cooling history and the uranium mineralization postdating the time of intrusion by 40-50 m.y. Numerical simulation of the post-emplacement cooling of the complex (<700°C) indicates that the pluton thermally equilibrated with its country rocks (at around 360-400°C and a mean depth of 10.5 km) by conduction in as little as 4 m.y. after its intrusion age (324 ± 4 Ma). Integration of the regional 40Ar /39Ar muscovite data in the 2-D model with an assumed universal Ar closure temperature of 325 ± 25°C reveals several sub-stages in the subsolidus cooling of the complex. The cooling pattern regionally defined by the muscovite data indicates that cooling was driven by the extensional exhumation and erosion of the thickened crust (+ intrusion) at a mean denudation rate of 0.3 mm y -1 Complete cooling below 325°C ended at 301 Ma via a transient faster denudation rate of 1.5 mm y -1 at the Westphalian-Stephanian boundary. The genetic relationships between the fluid circulations, the mineralization, and the cooling history of the pluton are discussed with particular emphasis on the tectonic process driving exhumation (extension). The initiation of the regional uplift at ˜320 Ma triggered at depth the circulation of in situ derived low-density aqueous fluids that reacted with the granite to form large vertical dissolution conduits (episyenites) characterized by the strong leaching of SiO 2. The hydrothermal alteration was further enhanced during uplift by the structurally focused throughput of large volumes of aqueous fluids along brittle faults cutting across the laccolith. These conduits acted more than 20-30 m.y. after the trap formation as preferential channelways for the U-ore deposition at 270-280 Ma, due to sustained hydrothermal circulation adjacent to the high-heat producing

  20. Spatial distribution and compositional variation of APS minerals related to uranium deposits in the Kiggavik-Andrew Lake structural trend, Nunavut, Canada

    NASA Astrophysics Data System (ADS)

    Riegler, Thomas; Quirt, Dave; Beaufort, Daniel

    2016-02-01

    The Kiggavik-Andrew Lake structural trend consists of four mineralized zones, partially outcropping, lying 2 km south of the erosional contact with the unmetamorphosed sandstone and basal conglomerates of the Paleoproterozoic Thelon Formation. The mineralization is controlled by a major E-W fault system associated with illite and sudoite alteration halos developed in the Archean metagraywackes of the Woodburn Lake Group. Aluminum phosphate sulfate (APS) minerals from the alunite group crystallized in association with the clay minerals in the basement alteration halo as well as in the overlying sandstones, which underwent mostly diagenesis. APS minerals are Sr- and S-rich (svanbergite end-member) in the sedimentary cover overlying the unconformity, whereas they are light rare earth elements (LREE)-rich (florencite end-member) in the altered basement rocks below the unconformity. The geochemical signature of each group of APS minerals together with the petrography indicates three distinct generations of APS minerals related to the following: (1) paleoweathering of continental surfaces prior to the basin occurrence, (2) diagenetic processes during the burial history of the lower unit of the Thelon sandstones, and (3) hydrothermal alteration processes which accompanied the uranium deposition in the basement rocks and partially overlap the sedimentary-diagenetic mineral parageneses. In addition, the association of a first generation of APS minerals with both detrital cerium oxide and aluminum oxy-hydroxide highlights the fact that a part of the detrital material of the basal Thelon Formation originated from eroded paleolaterite (allochthonous regolith). The primary rare earth element (REE)-bearing minerals (e.g., monazite, REE carbonates, and allanite) of the host rocks were characterized to identify the potential sources of REE. The REE chemical composition highlights a local re-incorporation of the REE released from the alteration processes in the APS minerals of

  1. Petrogenetic evolution of Late Paleozoic rhyolites of the Harvey Group, southwestern New Brunswick (Canada) hosting uranium mineralization

    NASA Astrophysics Data System (ADS)

    Dostal, J.; van Hengstum, T. R.; Shellnutt, J. G.; Hanley, J. J.

    2016-06-01

    The 360 Ma subaerial felsic volcanic and volcaniclastic rocks of the Harvey Group form a belt about 15 km long and 3 km wide in southwestern New Brunswick (Canada) that has been correlated with parts of the Mount Pleasant caldera complex, the site of a significant polymetallic (tin, tungsten, molybdenum, indium and bismuth) deposit. The Harvey volcanic rocks are highly fractionated peraluminous within-plate F-rich rhyolites, which host uranium mineralization. The rocks were modified by late-magmatic and post-magmatic processes. A comparison of the composition of whole rocks and melt inclusions in the quartz phenocrysts shows that some trace elements, including U, were affected by the post-magmatic processes. Their flat REE patterns accompanied by distinct negative Eu anomalies are typical of highly evolved F-rich leucogranites and rhyolites. Nd isotopic ratios (ɛNd(360) = +0.6 to -1.0) are similar to those of the felsic rocks of the Mount Pleasant complex. The Harvey rhyolites were generated by extensive fractional crystallization of andesites of the Mount Pleasant caldera. The melt evolved at the apex of the magma chamber where volatile elements become concentrated. The Harvey rhyolite (with melt inclusions containing ~20 ppm U) had the potential to develop a significant U mineralization. The erupted glassy rhyolite is a favorable U source rock amendable to leaching by post-magmatic hydrothermal and meteoric water. The high Th/U ratios in the Harvey volcanic rocks compared to the low ratios in the U-rich melt inclusions is indicative of such a process.

  2. Agricolaite, a new mineral of uranium from Jáchymov, Czech Republic

    NASA Astrophysics Data System (ADS)

    Skála, Roman; Ondruš, Petr; Veselovský, František; Císařová, Ivana; Hloušek, Jan

    2011-11-01

    The new mineral agricolaite, a potassium uranyl carbonate with ideal formula K4(UO2)(CO3)3, occurs in vugs of ankerite gangue in gneisses in the abandoned Giftkiesstollen adit at Jáchymov, Czech Republic. The name is after Georgius Agricola (1494-1555), German scholar and scientist. Agricolaite occurs as isolated equant irregular translucent grains to 0.3 mm with yellow color, pale yellow streak, and vitreous luster. It is brittle with uneven fracture and displays neither cleavage nor parting. Agricolaite is non-fluorescent. Mohs hardness is ~4. It is associated with aragonite, brochantite, posnjakite, malachite, rutherfordine, and "pseudo-voglite". Experimental density is higher than 3.3 g.cm-3, Dcalc is 3.531 g. cm-3. The mineral is monoclinic, space group C2/ c, with a 10.2380(2), b 9.1930(2), c 12.2110(3) Å, β 95.108(2)°, V 1144.71(4) Å3, Z = 4. The strongest lines in the powder X-ray diffraction pattern are d( I)( hkl): 6.061(55)(002), 5.087(57)(200), 3.740(100)(202), 3.393(43)(113), 2.281(52)(402). Average composition based on ten electron microprobe analyses corresponds to (in wt.%) UO3 48.53, K2O 31.49, CO2(calc) 22.04 which gives the empirical formula K3.98(UO2)1.01(CO3)3.00. The crystal structure was solved from single-crystal X-ray diffraction data and refined to R 1 = 0.0184 on the basis of the 1,308 unique reflections with F o > 4 σF o. The structure of agricolaite is identical to that of synthetic K4(UO2)(CO3)3 and consists of separate UO2(CO3)3 groups organized into layers parallel to (100) and two crystallographically non-equivalent sites occupied by K+ cations. Both the mineral and its name were approved by the IMA-CNMNC.

  3. Fixation of radionuclides in the 238U decay series in the vicinity of mineralized zones: 1. The Austatom Uranium Prospect, Northern Territory, Australia

    NASA Astrophysics Data System (ADS)

    Shirvington, P. J.

    1983-03-01

    The minimum age of a zone of secondary uranium mineralization, located at the Austatom Prospect in the Alligator Rivers region of Australia, is estimated to be 3.6 × 10 5y. This is derived from a geochronological model based on retarded leaching of 234U with respect to 238U and on ratios within the ore of these members of the 238U decay series. Although kaolinite is a dominant mineral in the weathered schist-host-rocks, retarded dissolution of 234U occurs only in the presence of the clay minerals illite and montmorillonite. In their absence the reverse occurs. A model is proposed to explain the results. Ratios of 230Th to 238U indicate that the mineralization has probably remained stationary within the weathered schist for at least 1 to 2 × 10 5y. Future use of clay minerals as buffers in radioactive waste repositories is supported by the excellent long-term retention obtained for oxidized uranium, probably due in part to isomorphic substitution into the clay crystal lattice.

  4. Geology and mineral resources of the Florence, Beaufort, Rocky Mount, and Norfolk 1/sup 0/ x 2/sup 0/ NTMS quadrangles. National Uranium Resource Evaluation program

    SciTech Connect

    Harris, W.B.

    1982-08-01

    This document provides geologic and mineral resources data for previously-issued Savannah River Laboratory hydrogeochemical and stream sediment reports of the Beaufort, Florence, Norfolk, and Rocky Mount 1/sup 0/ x 2/sup 0/ National Topographic Map Series quadrangles in the southeastern United States. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the National Uranium Resource Evaluation program.

  5. Isotopic Evidence for Reductive Immobilization of Uranium Across a Roll-Front Mineral Deposit.

    PubMed

    Brown, Shaun T; Basu, Anirban; Christensen, John N; Reimus, Paul; Heikoop, Jeffrey; Simmons, Ardyth; Woldegabriel, Giday; Maher, Kate; Weaver, Karrie; Clay, James; DePaolo, Donald J

    2016-06-21

    We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in groundwater across a roll front redox gradient. Our study was conducted at the Smith Ranch-Highland in situ recovery (ISR) U mine in eastern Wyoming, USA, where economic U deposits occur in the Paleocene Fort Union formation. To evaluate the fate of aqueous U in and adjacent to the ore body, we investigated the chemical composition and isotope ratios of groundwater samples from the roll-front type ore body and surrounding monitoring wells of a previously mined area. The (238)U/(235)U of groundwater varies by approximately 3‰ and is correlated with U concentrations. Fluid samples down-gradient of the ore zone are the most depleted in (238)U and have the lowest U concentrations. Activity ratios of (234)U/(238)U are ∼5.5 up-gradient of the ore zone, ∼1.0 in the ore zone, and between 2.3 and 3.7 in the down-gradient monitoring wells. High-precision measurements of (234)U/(238)U and (238)U/(235)U allow for development of a conceptual model that evaluates both the migration of U from the ore body and the extent of natural attenuation due to reduction. We find that the premining migration of U down-gradient of the delineated ore body is minimal along eight transects due to reduction in or adjacent to the ore body, whereas two other transects show little or no sign of reduction in the down-gradient region. These results suggest that characterization of U isotopic ratios at the mine planning stage, in conjunction with routine geochemical analyses, can be used to identify where more or less postmining remediation will be necessary. PMID:27203292

  6. Isotopic evidence for reductive immobilization of uranium across a roll-front mineral deposit

    DOE PAGESBeta

    Brown, Shaun T.; Basu, Anirban; Christensen, John N.; Reimus, Paul; Heikoop, Jeffrey; Simmons, Ardyth; Woldegabriel, Giday; Maher, Kate; Weaver, Karrie; Clay, James; et al

    2016-06-21

    We use uranium (U) isotope ratios to detect and quantify the extent of natural U reduction in groundwater across a roll front redox gradient. Our study was conducted at the Smith Ranch-Highland in situ recovery (ISR) U mine in eastern Wyoming, USA, where economic U deposits occur in the Paleocene Fort Union formation. To evaluate the fate of aqueous U in and adjacent to the ore body, we investigated the chemical composition and isotope ratios of groundwater samples from the roll-front type ore body and surrounding monitoring wells of a previously mined area. The 238U/235U of groundwater varies by approximatelymore » 3‰ and is correlated with U concentrations. Fluid samples down-gradient of the ore zone are the most depleted in 238U and have the lowest U concentrations. Activity ratios of 234U/238U are ~5.5 up-gradient of the ore zone, ~1.0 in the ore zone, and between 2.3 and 3.7 in the down-gradient monitoring wells. High-precision measurements of 234U/238U and 238U/235U allow for development of a conceptual model that evaluates both the migration of U from the ore body and the extent of natural attenuation due to reduction. We find that the premining migration of U down-gradient of the delineated ore body is minimal along eight transects due to reduction in or adjacent to the ore body, whereas two other transects show little or no sign of reduction in the down-gradient region. Lastly, these results suggest that characterization of U isotopic ratios at the mine planning stage, in conjunction with routine geochemical analyses, can be used to identify where more or less postmining remediation will be necessary.« less

  7. Feasibility of using fluorescence in situ hybridization (FISH) to detect early gene changes in sputum cells from uranium miners

    SciTech Connect

    Neft, R.E.; Rogers, J.L.; Belinsky, S.A.

    1995-12-01

    Epidemiological studies have shown that combined exposure to radon progeny and tobacco smoke produce a greater than additive or synergistic increase in lung cancer risk. Lung cancer results from multiple genetic changes over a long period of time. An early change that occurs in lung cancer is trisomy 7 which is found in 50% of non-small cell lung cancer and in the far margins of resected lung tumors. The 80% mortality associated with lung cancer is in part related to the high proportion of patients who present with an advanced, unresectable tumor. Therefore, early detection of patients at risk for tumor development is critical to improve treatment of this disease. Currently, it is difficult to detect lung cancer early while it is still amendable by surgery. Saccomanno, G. has shown that premalignant cytologic changes in sputum cells collected from uranium miners can be detected by a skilled, highly trained cytopathologist. A more objective alternative for identifying premalignant cells in sputum may be to determine whether an early genetic change such as trisomy 7 is present in these cells. Fluorescence in situ hybridization (FISH) can be used to identify cells with trisomy 7. The results of this investigation indicate that FISH may prove to be an accurate, efficient method to test at-risk individuals for genetic alterations in bronchial epithelial cells from sputum.

  8. 3D Reconstruction of Biological Organization and Mineralization in Sediment Attached Biofilms During Uranium Bioremediation

    SciTech Connect

    Banfield, Jillian; Comolli, Luis R.; Singer, Steve

    2014-11-17

    development of a platform for routine correlative cryogenic microscopy and spectroscopy with samples prepared on-site. 2) The determination of which organisms dominate planktonic and biofilm communities in the subsurface. 3) Identification of microorganism-mineral associations and discovery of a novel mechanism that sustains activity of iron-reducing bacteria. 4) The detection of bacteria from the OP11-OD1-WWE3 (etc.) radiation and elucidation of their remarkable structural organization by cryog-TEM cryo-electron tomograhpy (cryo-ET). 5) Extensive analysis of biofilms and documentation of the association of cells and Se minerals. 6) The comparison of expressed c-type cytochromes between pure cultures of G. bemidjiensis and related field populations, provided insight into possible molecular mechanisms for U(VI) reduction in the aquifer. At least sixteen publications will result from this project (partial support), which provide both graduate student and post doctoral training.

  9. External gamma radiation and mortality from cardiovascular diseases in the German WISMUT uranium miners cohort study, 1946-2008.

    PubMed

    Kreuzer, M; Dufey, F; Sogl, M; Schnelzer, M; Walsh, L

    2013-03-01

    It is currently unclear whether exposure of the heart and vascular system, at lifetime accumulated dose levels relevant to the general public (<500 mGy), is associated with an increased risk of cardiovascular disease. Therefore, data from the German WISMUT cohort of uranium miners were investigated for evidence of a relationship between external gamma radiation and death from cardiovascular diseases. The cohort comprises 58,982 former employees of the Wismut company. There were 9,039 recorded deaths from cardiovascular diseases during the follow-up period from 1946 to 2008. Exposures to external gamma radiation were estimated using a detailed job-exposure matrix. The exposures were based on expert ratings for the period 1946-1954 and measurements thereafter. The excess relative risk (ERR) per unit of cumulative gamma dose was obtained with internal Poisson regression using a linear ERR model with baseline stratification by age and calendar year. The mean cumulative gamma dose was 47 mSv for exposed miners (86 %), with a maximum of 909 mSv. No evidence for an increase in risk with increasing cumulative dose was found for mortality from all cardiovascular diseases (ERR/Sv = -0.13; 95 % confidence interval (CI): -0.38; 0.12) and ischemic heart diseases (n = 4,613; ERR/Sv = -0.03; 95 % CI: -0.38, 0.32). However, a statistically insignificant increase (n = 2,073; ERR/Sv = 0.44; 95 % CI: -0.16, 1.04) for mortality from cerebrovascular diseases was observed. Data on smoking, diabetes, and overweight are available for subgroups of the cohort, indicating no major correlation with cumulative gamma radiation. Confounding by these factors or other risk factors, however, cannot be excluded. In conclusion, the results provide weak evidence for an increased risk of death due to gamma radiation only for cerebrovascular diseases. PMID:23192731

  10. Isotopes of uranium and thorium, lead-210, and polonium-210 in the lungs of coal miners of Appalachia and the lungs and livers of residents of central Ohio

    SciTech Connect

    Gilbert, G.E.; Casella, V.R.; Bishop, C.T.; Aguirre, A.G.

    1985-10-21

    The lungs of twelve and the livers of three residents of central Ohio and the lungs of four coal miners of Appalachia were analyzed for uranium-238, uranium-234, thorium-230, lead-210, polonium-210, and thorium-232. Mean and median lung concentrations of uranium-238 and of uranium-234 in the lungs of central Ohioans were essentially the same and were equal to 4 fCi/g dry. Mean concentrations of these isotopes in the lungs of Appalachian coal miners were also essentially the same and were equal to 9 fCi/g. Little uranium was found in the liver. The median concentration of thorium-230 in the lungs of central Ohioans was also 4 fCi/g dry; however, the mean concentration was 8 fCi/g due to the relatively high concentration values in a few persons. The mean concentrations of this isotope in the lungs of central Ohioans and Appalachian coal miners were essentially the same; i.e. 8 fCi/g. The mean and median concentrations of thorium-232 in the lungs of central Ohioans were assentially the same and equal to 4 fCi/g. The mean concentration of this isotope in the lungs of Appalachian coal miners was 9 fCi/g. Little thorium was found in the liver. The mean concentrations of lead-210 in the lungs of the two populations were nearly equal and about 23 fCi/g dry. The mean liver/lung ratio of this isotope was essentially two, and the concentrations appeared to be positively correlated with smoking. Polonium-210 concentrations in the lungs were distributed into three sets of values which are described here as low (2-4 fCi/g), medium (20-30 fCi/g), and high (>100 fCi/g), and also appeared to be correlated with smoking. Mean liver concentrations of this irotope were nearly equal to the mean liver concentrations of lead-210 (50 as opposed to 47 fCi/g). 18 refs., 6 tabs.

  11. Large-basin ground water circulation and paleo-reconstruction of circulation leading to uranium mineralization in Grand Canyon breccia pipes, Arizona

    SciTech Connect

    Huntoon, P.W.

    1996-07-01

    Breccia pipes - vertical collapse structures - are common in the Phanerozoic sedimentary section in the Grand Canyon region. Breccias in economically significant pipes are as great as 900 m high and 90 m in diameter. The pipes originated through collapse into paleocaverns in Mississippian carbonates. The large heights of the mineralized pipes is attributed to upward stoping resulting from progressive creation of space within the pipes through dissolution of wall rocks and soluble constituents in the breccia clasts. The paleocaves that served as nucleation sites for the pipes date from Mississippian time. Stoping appears to have been reactivated or accelerated during Triassic time as terrains to the south became uplifted. Uplift cause hydraulic gradients within aquifers in the Paleozoic section to increase significantly which enhanced ground water circulation and attendant dissolution. The most likely source for uranium in the Grand Canyon breccia pipes was eroding volcanic and Precambrian crystalline rocks in the Triassic Mogollon highlands south of the Grand Canyon region. The circulation model proposed herein assumes that uranium-rich waters originating in the highlands recharged through the exposed Redwall Limestone and circulated northward in the artesian Redwall aquifer. On reaching the Grand Canyon region, the water circulated upward into the Phanerozoic section in the breccia pipes which served as permeability pathways through thick confining strata. The pipes concentrated fluid circulation and directed it through reducing environments which caused precipitation of the uranium and associated metals yielding a number of economic uranium ore bodies. The architecture of the circulation systems in the Colorado plateau prior to incision of the Colorado river was such that hydraulic heads decreased within successively shallower aquifers. Consequently, head gradients at any location were upward in the pipes during the mineralizing stages.

  12. U-Pb ages of uraniferous opals and implications for the history of beryllium, fluorine, and uranium mineralization at Spor Mountain, Utah

    USGS Publications Warehouse

    Ludwig, K. R.; Lindsey, D.A.; Zielinski, R.A.; Simmons, K.R.

    1980-01-01

    The U-Pb isotope systematics of uraniferous opals from Spor Mountain, Utah, were investigated to determine the suitability of such material for geochronologic purposes, and to estimate the timing of uranium and associated beryllium and fluorine mineralization. The results indicate that uraniferous opals can approximate a closed system for uranium and uranium daughters, so that dating samples as young as ???1 m.y. should be possible. In addition, the expected lack of initial 230Th and 231Pa in opals permits valuable information on the initial 234U/238U to be obtained on suitable samples of ???10 m.y. age. The oldest 207Pb/235U apparent age observed, 20.8 ?? 1 m.y., was that of the opal-fluorite core of a nodule from a beryllium deposit in the Spor Mountain Formation. This age is indistinguishable from that of fission-track and K-Ar ages from the host rhyolite, and links the mineralization to the first episode of alkali rhyolite magmatism and related hydrothermal activity at Spor Mountain. Successively younger ages of 13 m.y. and 8-9 m.y. on concentric outer zones of the same nodule indicate that opal formed either episodically or continuously for over 10 m.y. Several samples of both fracture-filling and massive-nodule opal associated with beryllium deposits gave 207Pb/235U apparent ages of 13-16 m.y., which may reflect a restricted period of mineralization or perhaps an averaging of 21- and <13-m.y. periods of opal growth. Several samples of fracture-filling opal in volcanic rocks as young as 6 m.y. gave 207Pb/235U ages of 3.4-4.8 m.y. These ages may reflect hot-spring activity after the last major eruption of alkali rhyolite. ?? 1980.

  13. Application of mineral-solution equilibria to geochemical exploration for sandstone-hosted uranium deposits in two basins in west central Utah.

    USGS Publications Warehouse

    Miller, W.R.; Wanty, R.B.; McHugh, J.B.

    1984-01-01

    This study applies mineral-solution equilibrium methods to the interpretation of ground-water chemistry in evaluating the uranium potential of the Beaver and Milford basins in west central Utah. Waters were collected mainly from wells and springs at 100 sites in limited areas in the basins, and in part from mixed sources. The waters were analysed for T, pH, alkalinity, specific conductance, SO4, Cl, F, NO3, Ca, Mg, Na, K, SiO2, Zn, Cu, Mo, As, U, V, Se, Li, Fe, Mn, and Al on different fractions. A computer model (WATEQ3) was used to calculate the redox potential and the state of saturation of the waters with respect to uraninite, coffinite, realgar and arsenopyrite. Mineral saturation studies have reliably predicted the location of known (none given here) U deposits and are more diagnostic of these deposits than are concentrations of indicator elements (U, Mo, As, Se). Several areas in the basins have ground-water environments of reducing redox potential, favourable for precipitation of reduced U minerals, and some of these areas are saturated or near-saturated with respect to uraninite and coffinite. The approach shows only that the environment is favourable locally for precipitation of reduced U minerals, but thereby locates exploration targets for (modern?) sandstone-hosted U deposits.-G.J.N.

  14. Deposition and diagenesis of the Brushy Basin and upper Westwater Canyon members of the Morrison Formation in northwest New Mexico and its relationship to uranium mineralization

    SciTech Connect

    Bell, T.E.

    1983-01-01

    Diagenetic facies in the upper Westwater Canyon and Brushy Basin Members closely parallel the distribution of lithofacies, just as in the smaller closed basins of late Cenozoic age of western North America. Vitric ash in the sediment has altered to montmorillonite in the fluvial facies. Calcite and montmorillonite are the alteration products where the fluvial and outermost playa facies meet. Vitric ash has altered to clinoptilolite and heulandite along the playa margins. In the center of the playa facies, analcime has replaced clinoptilolite, an early zeolite. Diagenetic zonation of this type is a result of pH and salinity gradients which existed across the basin. These early diagenetic minerals were replaced by albite, quartz, and mixed-layer illite-montmorillonite where the upper Westwater Canyon and Brushy Basin Members have been deeply buried in the San Juan basin. Relatively fresh ground water carrying dissolved organic compounds and uranium mixed with the saline alkaline brine from underlying playa mudstones, result in uranium mineralization of the upper Jurassic Morrison Formation near Laguna New Mexico.

  15. Radiation-associated lung cancer: A comparison of the histology of lung cancers in uranium miners and survivors of the atomic bombings of Hiroshima and Nagasaki

    SciTech Connect

    Land, C.E.; Shimosato, Y.; Saccomanno, G.; Tokuoka, S.; Auerbach, O.; Tateishi, R.; Greenberg, S.D.; Nambu, S.; Carter, D.; Akiba, S. )

    1993-05-01

    A binational panel of Japanese and American pulmonary pathologists reviewed tissue slides of lung cancer cases diagnosed among Japanese A-bomb survivors and American uranium miners and classified the cases according to histological subtype. Blind reviews were completed on slides from 92 uranium miners and 108 A-bomb survivors, without knowledge of population, sex, age, smoking history, or level of radiation exposure. Consensus diagnoses were obtained with respect to principal subtype, including squamous-cell cancer, small-cell cancer, adenocarcinoma, and less frequent subtypes. The results were analyzed in terms of population, radiation dose, and smoking history. As expected, the proportion of squamous-cell cancer was positively related to smoking history in both populations. The relative frequencies of small-cell cancer and adenocarcinoma were very different in the two populations, but this difference was accounted for adequately by differences in radiation dose or, more specifically, dose-based relative risk estimates based on published data. Radiation-induced cancers appeared more likely to be of the small-cell subtype, and less likely to be adenocarcinomas, in both populations. The data appeared to require no additional explanation in terms of radiation quality (alpha particles vs gamma rays), uniform or local irradiation, inhaled vs external radiation source, or other population difference.

  16. Effect of mineral constituents in the bioleaching of uranium from uraniferous sedimentary rock samples, Southwestern Sinai, Egypt.

    PubMed

    Amin, Maisa M; Elaassy, Ibrahim E; El-Feky, Mohamed G; Sallam, Abdel Sattar M; Talaat, Mona S; Kawady, Nilly A

    2014-08-01

    Bioleaching, like Biotechnology uses microorganisms to extract metals from their ore materials, whereas microbial activity has an appreciable effect on the dissolution of toxic metals and radionuclides. Bioleaching of uranium was carried out with isolated fungi from uraniferous sedimentary rocks from Southwestern Sinai, Egypt. Eight fungal species were isolated from different grades of uraniferous samples. The bio-dissolution experiments showed that Aspergillus niger and Aspergillus terreus exhibited the highest leaching efficiencies of uranium from the studied samples. Through monitoring the bio-dissolution process, the uranium grade and mineralogic constituents of the ore material proved to play an important role in the bioleaching process. The tested samples asserted that the optimum conditions of uranium leaching are: 7 days incubation time, 3% pulp density, 30 °C incubation temperature and pH 3. Both fungi produced the organic acids, namely; oxalic, acetic, citric, formic, malonic, galic and ascorbic in the culture filtrate, indicating an important role in the bioleaching processes. PMID:24682031

  17. Hydrochemical monitoring results in relation to the vogtland-nw bohemian earthquake swarm period 2000

    NASA Astrophysics Data System (ADS)

    Kämpf, H.; Bräuer, K.; Dulski, P.; Faber, E.; Koch, U.; Mrlina, J.; Strauch, G.; Weise, S. M.

    2003-04-01

    The Vogtland-NW Bohemian earthquake swarm area/Central Europe is characterised by carbon dioxide- rich mineral springs and mofetts. The August-December 2000 earthquake period was the strongest compared with the December 1985/86 swarms occurred in the area of Novy Kostel, Czech Republic. Here, we present first results of long-term hydrochemical monitoring studies before, during and after the 2000 swarm period. The swarm 2000 lasted from August 28 until December 26 and consisted of altogether nine sub-swarm episodes, each of them lasting for several days. At the mineral spring Wettinquelle, Bad Brambach/Germany the water chemistry and isotope (D, 18O) composition was monitored weekly and two-weekly, respectively, since May 2000. The mineral spring Wettinquelle is located in a distance of about 10 km from the epicentral area of Novy Kostel. The aim of our investigation was to look for seismic induced or seismic coupled changes of the chemical and isotope composition of the mineral water. We had to separate seismohydrological effects from seasonal and hydrological caused changes. The seasonal caused shifts were found for water temperature and alkaline elements (Li, Na, K, Rb and Cs) as well as for discharge, conductivity, hydrogenecarbonate- concentration, and the concentration of the alkaline earth's (Ca, Mg, Sr). Strain related anomalies which could influence the hydrogeochemistry of the mineral water seems to be visible in the iron- concentration of the spring water, in the methane- concentration of the free gas component and caused probably changes of the groundwater level of the well H3 located about 5 km SE of the Wettinquelle at Skalna.

  18. Tectono-metamorphic evolution of the internal zone of the Pan-African Lufilian orogenic belt (Zambia): Implications for crustal reworking and syn-orogenic uranium mineralizations

    NASA Astrophysics Data System (ADS)

    Eglinger, Aurélien; Vanderhaeghe, Olivier; André-Mayer, Anne-Sylvie; Goncalves, Philippe; Zeh, Armin; Durand, Cyril; Deloule, Etienne

    2016-01-01

    The internal zone of the Pan-African Lufilian orogenic belt (Zambia) hosts a dozen uranium occurrences mostly located within kyanite micaschists in a shear zone marking the contact between metasedimentary rocks attributed to the Katanga Neoproterozoic sedimentary sequence and migmatites coring domes developed dominantly at the expense of the pre-Neoproterozoic basement. The P-T-t-d paths reconstructed for these rocks combining field observations, microstructural analysis, metamorphic petrology and thermobarometry and geochronology indicate that they have recorded burial and exhumation during the Pan-African orogeny. Both units of the Katanga metasedimentary sequence and pre-Katanga migmatitic basement have underwent minimum peak P-T conditions of ~ 9-11 kbar and ~ 640-660 °C, dated at ca. 530 Ma by garnet-whole rock Lu-Hf isochrons. This suggests that this entire continental segment has been buried up to a depth of 40-50 km with geothermal gradients of 15-20 °C.km- 1 during the Pan-African orogeny and the formation of the West Gondwana supercontinent. Syn-orogenic exhumation of the partially molten root of the Lufilian belt is attested by isothermal decompression under P-T conditions of ~ 6-8 kbar at ca. 530-500 Ma, witnessing an increase of the geothermal gradients to 25-30 °C·km- 1. Uranium mineralizations that consist of uraninite and brannerite took place at temperatures ranging from ~ 600 to 700 °C, and have been dated at ca. 540-530 Ma by U-Pb ages on uraninite. The main uranium deposition thus occurred at the transition from the syn-orogenic burial to the syn-orogenic exhumation stages and has been then partially transposed and locally remobilized during the post-orogenic exhumation accommodated by activation of low-angle extensional detachment.

  19. Prostate cancer mortality risk in relation to working underground in the Wismut cohort study of German uranium miners, 1970–2003

    PubMed Central

    Dufey, Florian; Tschense, Annemarie; Schnelzer, Maria; Sogl, Marion; Kreuzer, Michaela

    2012-01-01

    Objective A recent study and comprehensive literature review has indicated that mining could be protective against prostate cancer. This indication has been explored further here by analysing prostate cancer mortality in the German ‘Wismut’ uranium miner cohort, which has detailed information on the number of days worked underground. Design An historical cohort study of 58 987 male mine workers with retrospective follow-up before 1999 and prospective follow-up since 1999. Setting and participants Uranium mine workers employed during the period 1970–1990 in the regions of Saxony and Thuringia, Germany, contributing 1.42 million person-years of follow-up ending in 2003. Outcome measure Simple standardised mortality ratio (SMR) analyses were applied to assess differences between the national and cohort prostate cancer mortality rates and complemented by refined analyses done entirely within the cohort. The internal comparisons applied Poisson regression excess relative prostate cancer mortality risk model with background stratification by age and calendar year and a whole range of possible explanatory covariables that included days worked underground and years worked at high physical activity with γ radiation treated as a confounder. Results The analysis is based on miner data for 263 prostate cancer deaths. The overall SMR was 0.85 (95% CI 0.75 to 0.95). A linear excess relative risk model with the number of years worked at high physical activity and the number of days worked underground as explanatory covariables provided a statistically significant fit when compared with the background model (p=0.039). Results (with 95% CIs) for the excess relative risk per day worked underground indicated a statistically significant (p=0.0096) small protective effect of −5.59 (−9.81 to −1.36) ×10−5. Conclusion Evidence is provided from the German Wismut cohort in support of a protective effect from working underground on prostate cancer mortality risk. PMID

  20. Genetic variation in SIRT1 affects susceptibility of lung squamous cell carcinomas in former uranium miners from the Colorado plateau

    PubMed Central

    Leng, Shuguang; Picchi, Maria A.; Liu, Yushi; Thomas, Cynthia L.; Willis, Derall G.; Bernauer, Amanda M.; Carr, Teara G.; Mabel, Padilla T.; Han, Younghun; Amos, Christopher I.; Lin, Yong; Stidley, Christine A.; Gilliland, Frank D.; Jacobson, Marty R.; Belinsky, Steven A.

    2013-01-01

    Epidemiological studies of underground miners suggested that occupational exposure to radon causes lung cancer with squamous cell carcinoma (SCC) as the predominant histological type. However, the genetic determinants for susceptibility of radon-induced SCC in miners are unclear. Double-strand breaks induced by radioactive radon daughters are repaired primarily by non-homologous end joining (NHEJ) that is accompanied by the dynamic changes in surrounding chromatin, including nucleosome repositioning and histone modifications. Thus, a molecular epidemiological study was conducted to assess whether genetic variation in 16 genes involved in NHEJ and related histone modification affected susceptibility for SCC in radon-exposed former miners (267 SCC cases and 383 controls) from the Colorado plateau. A global association between genetic variation in the haplotype block where SIRT1 resides and the risk for SCC in miners (P = 0.003) was identified. Haplotype alleles tagged by the A allele of SIRT1 rs7097008 were associated with increased risk for SCC (odds ratio = 1.69, P = 8.2×10−5) and greater survival in SCC cases (hazard ratio = 0.79, P = 0.03) in miners. Functional validation of rs7097008 demonstrated that the A allele was associated with reduced gene expression in bronchial epithelial cells and compromised DNA repair capacity in peripheral lymphocytes. Together, these findings substantiate genetic variation in SIRT1 as a risk modifier for developing SCC in miners and suggest that SIRT1 may also play a tumor suppressor role in radon-induced cancer in miners. PMID:23354305

  1. Lung cancer in French and Czech uranium miners: Radon-associated risk at low exposure rates and modifying effects of time since exposure and age at exposure.

    PubMed

    Tomasek, Ladislav; Rogel, Agnès; Tirmarche, Margot; Mitton, Nicolas; Laurier, Dominique

    2008-02-01

    Radon is recognized as a public health concern for indoor exposure. Precise quantification derived from occupational exposure in miners is still needed for estimating the risk and the factors that modify the dependence on cumulated exposure. The present paper reports on relationship between radon exposure and lung cancer risk in French and Czech cohorts of uranium miners (n = 10,100). Miners from these two cohorts are characterized by low levels of exposure (average cumulated exposure of less than 60 WLM) protracted over a long period (mean duration of exposure of 10 years) and by a good quality of individual exposure estimates (95% of annual exposures based on radon measurements). The modifying effect of the quality of exposure on the risk is analyzed. A total of 574 lung cancer deaths were observed, which is 187% higher than expected from the national statistics. This significantly elevated risk is strongly associated with cumulated radon exposure. The estimated overall excess relative risk per WLM is 0.027 (95% CI: 0.017-0.043, related to measured exposures). For age at exposure of 30 and 20 years since exposure, the ERR/WLM is 0.042, and this value decreases by approximately 50% for each 10-year increase in age at exposure and time since exposure. The present study emphasizes that the quality of exposure estimates is an important factor that may substantially influence results. Time since exposure and simultaneously age at exposure were the most important effect modifiers. No inverse exposure-rate effect below 4 WL was observed. The results are consistent with estimates of the BEIR VI report using the concentration model at an exposure rate below 0.5 WL. PMID:18220460

  2. Assessment of the vertical distribution of natural radionuclides in a mineralized uranium area in south-west Spain.

    PubMed

    Blanco Rodríguez, P; Vera Tomé, F; Lozano, J C

    2014-01-01

    Low-level alpha spectrometry techniques using semiconductor detectors (PIPS) and liquid scintillation (LKB Quantulus 1220™) were used to determine the activity concentration of (238)U, (234)U, (230)Th, (226)Ra, (232)Th, and (210)Pb in soil samples. The soils were collected from an old disused uranium mine located in southwest Spain. The soils were sampled from areas with different levels of influence from the installation and hence had different levels of contamination. The vertical profiles of the soils (down to 40 cm depth) were studied in order to evaluate the vertical distribution of the natural radionuclides. To determine the origin of these natural radionuclides the Enrichment Factor was used. Also, study of the activity ratios between radionuclides belonging to the same radioactive series allowed us to assess the different types of behaviors of the radionuclides involved. The vertical profiles for the radionuclide members of the (238)U series were different at each sampling point, depending on the level of influence of the installation. However, the profiles of each point were similar for the long-lived radionuclides of the (238)U series ((238)U, (234)U, (230)Th, and (226)Ra). Moreover, a major imbalance was observed between (210)Pb and (226)Ra in the surface layer, due to (222)Rn exhalation and the subsequent surface deposition of (210)Pb. PMID:24182407

  3. Accounting for smoking in the radon-related lung cancer risk among German uranium miners: results of a nested case-control study.

    PubMed

    Schnelzer, Maria; Hammer, Gaël P; Kreuzer, Michaela; Tschense, Annemarie; Grosche, Bernd

    2010-01-01

    The possible confounding effect of smoking on radon-associated risk for lung cancer mortality was investigated in a case-control study nested in the cohort of German uranium miners. The study included 704 miners who died of lung cancer and 1,398 controls matched individually for birth year and attained age. Smoking status was reconstructed from questionnaires and records from the mining company's health archives for 421 cases and 620 controls. Data on radon exposure were taken from a job-exposure matrix. Smoking adjusted odds ratios for lung cancer in relation to cumulative radon exposure have been calculated with conditional logistic regression. The increase in risk per Working Level Month (WLM) was assessed with a linear excess relative risk (ERR) model taking smoking into account as a multiplicative factor. In addition, the potential impact of temporal factors on the ERR per WLM was examined. Lung cancer mortality risk increased with increasing radon exposure, yielding a crude ERR per WLM of 0.25% (95% CI: 0.13-0.46%). Adjustment for smoking led only to marginal changes of the radon-associated lung cancer risks. The adjusted ERR per WLM was very similar (0.23%, 95%-CI: 0.11-0.46%) to the crude risk and to the risk found in the Wismut cohort study. This stability of the radon-related lung cancer risks with and without adjustment for smoking suggests that smoking does not act as a major confounder in this study and presumably also not in the cohort study. PMID:19959947

  4. Computer-assisted decision aid for the estimation of mineral endowment: uranium in the San Juan Basin, New Mexico, a case study

    SciTech Connect

    Carrigan, F.J.

    1983-01-01

    This methodology comprises two main sections, each executed on a different computer system. The first section, the Geologic Decision Model, has been computerized as an interactive PLATO program. Using the PLATO system, the geologist describes probabilistically the perceived states of geologic processes and conditions. The decision model analyzes this information and computes a probability distribution for mineral occurrence. The second section, the Endowment Simulation Model (program MASTER), is run on the DEC 10 and Cyber 175 computers. Program MASTER takes the product of the Geologic Decision Model, combines it with other data, and produces a probabilistic estimate of mineral endowment for the region being evaluated. Development and testing of the Arizona Appraisal System were carried out simultaneously over a period of about three years. During this period, four geologists from government and industry were called upon four or five times over a period of about a year for a study of the uranium (U/sub 3/O/sub 8/) endowment in the San Juan Basin of northwestern New Mexico. The results produced by the system consist, for each geologist, of a probability distribution for tons of U/sub 3/O/sub 8/ endowment for (1) each partition of each stratigraphic unit, (2) each stratigraphic unit as a whole, (3) ''formations'' or ''merged units'' (groups of stratigraphic units), and (4) the San Juan Basin as a whole (all stratigraphic units). The system also calculates the average distribution across all geologists for the various merged units and for the basin as a whole. The result for the basin as a whole (in thousands of tons) is: mean 3,855, variance 4,108 x 10/sup 9/, and 95th percentile 6,541.

  5. Composition and Diversity of Microbial Communities Recovered from Surrogate Minerals Incubated in an Acidic Uranium-Contaminated Aquifer

    PubMed Central

    Reardon, Catherine L.; Cummings, David E.; Petzke, Lynn M.; Kinsall, Barry L.; Watson, David B.; Peyton, Brent M.; Geesey, Gill G.

    2004-01-01

    Our understanding of subsurface microbiology is hindered by the inaccessibility of this environment, particularly when the hydrogeologic medium is contaminated with toxic substances. In this study, surrogate geological media contained in a porous receptacle were incubated in a well within the saturated zone of a pristine region of an aquifer to capture populations from the extant communities. After an 8-week incubation, the media were recovered, and the microbial community that developed on each medium was compared to the community recovered from groundwater and native sediments from the same region of the aquifer, using 16S DNA coding for rRNA (rDNA)-based terminal restriction fragment length polymorphism (T-RFLP). The groundwater and sediment communities were highly distinct from one another, and the communities that developed on the various media were more similar to groundwater communities than to sediment communities. 16S rDNA clone libraries of communities that developed on particles of a specular hematite medium incubated in the same well as the media used for T-RFLP analysis were compared with those obtained from an acidic, uranium-contaminated region of the same aquifer. The hematite-associated community formed in the pristine area was highly diverse at the species level, with 25 distinct phylotypes identified, the majority of which (73%) were affiliated with the β-Proteobacteria. Similarly, the hematite-associated community formed in the contaminated area was populated in large part by β-Proteobacteria (62%); however, only 13 distinct phylotypes were apparent. The three numerically dominant clones from the hematite-associated community from the contaminated site were affiliated with metal- and radionuclide-tolerant or acidophilic taxa, consistent with the environmental conditions. Only two populations were common to both sites. PMID:15466548

  6. Multistage evolution of UHT granulites from the southernmost part of the Gföhl Nappe, Bohemian Massif, Lower Austria

    NASA Astrophysics Data System (ADS)

    Schantl, Philip; Hauzenberger, Christoph; Linner, Manfred

    2016-04-01

    A detailed petrological investigation has been undertaken in leucocratic kyanite-garnet bearing and mesocratic orthopyroxene bearing granulites from the Dunkelsteiner Wald, Pöchlarn-Wieselburg and Zöbing granulite bodies from the Moldanubian Zone in the Bohemian Massif (Austria). A combination of textural observations, conventional geothermobarometry, phase equilibrium modelling as well as major and trace element analyses in garnet enables us to confirm a multistage Variscan metamorphic history. Chemically homogenous garnet cores with near constant grossular-rich plateaus are considered to reflect garnet growth during an early HP/UHP metamorphic evolution. Crystallographically oriented rutile exsolutions restricted to those grossular-rich garnet cores point to a subsequent isothermal decompression of the HP/UHP rocks. Overgrowing garnet rims show a pronounced zonation and are interpreted as the result of dehydration melting reactions during an isobaric heating phase which could have taken place near the base of an overthickened continental crust, where the previously deeply subducted rocks were exhumed to. For this HP granulite facies event maximum PT conditions of ~1050 °C and 1.6 GPa have been estimated from leucocratic granulites comprising the peak mineral assemblage quartz, ternary feldspar, garnet, kyanite and rutile. The pronounced zoning of garnet rims indicates that the HP granulite facies event must have been short lived since diffusion in this temperature region is usually sufficient fast to homogenize a zoning pattern in garnet. A retrogressive metamorphic stage is documented in these rocks by the replacement of kyanite to sillimanite and the growth of biotite. This retrograde event took place within the granulite facies but at significantly lower pressures and temperatures with ~0.8 GPa and ~760 °C. This final stage of re-equilibration is thought to be linked with a second exhumation phase into middle crustal levels accompanied by intensive

  7. The Nolans Bore rare-earth element-phosphorus-uranium mineral system: geology, origin and post-depositional modifications

    NASA Astrophysics Data System (ADS)

    Huston, David L.; Maas, Roland; Cross, Andrew; Hussey, Kelvin J.; Mernagh, Terrence P.; Fraser, Geoff; Champion, David C.

    2016-01-01

    Nolans Bore is a rare-earth element (REE)-U-P fluorapatite vein deposit hosted mostly by the ~1805 Ma Boothby Orthogneiss in the Aileron Province, Northern Territory, Australia. The fluorapatite veins are complex, with two stages: (1) massive to granular fluorapatite with inclusions of REE silicates, phosphates and (fluoro)carbonates, and (2) calcite-allanite with accessory REE-bearing phosphate and (fluoro)carbonate minerals that vein and brecciate the earlier stage. The veins are locally accompanied by narrow skarn-like (garnet-diopside-amphibole) wall rock alteration zones. SHRIMP Th-Pb analyses of allanite yielded an age of 1525 ± 18 Ma, interpreted as the minimum age of mineralisation. The maximum age is provided by a ~1550 Ma SHRIMP U-Pb age for a pegmatite that predates the fluorapatite veins. Other isotopic systems yielded ages from ~1443 to ~345 Ma, implying significant post-depositional isotopic disturbance. Calculation of initial ɛNd and 87Sr/86Sr at 1525 Ma and stable isotope data are consistent with an enriched mantle or lower crust source, although post-depositional disturbance is likely. Processes leading to formation of Nolans Bore began with north-dipping subduction along the south margin of the Aileron Province at 1820-1750 Ma, producing a metasomatised, volatile-rich, lithospheric mantle wedge. About 200 million years later, near the end of the Chewings Orogeny, this reservoir and/or the lower crust sourced alkaline low-degree partial melts which passed into the mid- and upper-crust. Fluids derived from these melts, which may have included phosphatic melts, eventually deposited the Nolans Bore fluorapatite veins due to fluid-rock interaction, cooling, depressurisation and/or fluid mixing. Owing to its size and high concentration of Th (2500 ppm), in situ radiogenic heating caused significant recrystallisation and isotopic resetting. The system finally cooled below 300 °C at ~370 Ma, possibly in response to unroofing during the Alice Springs

  8. The Nolans Bore rare-earth element-phosphorus-uranium mineral system: geology, origin and post-depositional modifications

    NASA Astrophysics Data System (ADS)

    Huston, David L.; Maas, Roland; Cross, Andrew; Hussey, Kelvin J.; Mernagh, Terrence P.; Fraser, Geoff; Champion, David C.

    2016-08-01

    Nolans Bore is a rare-earth element (REE)-U-P fluorapatite vein deposit hosted mostly by the ~1805 Ma Boothby Orthogneiss in the Aileron Province, Northern Territory, Australia. The fluorapatite veins are complex, with two stages: (1) massive to granular fluorapatite with inclusions of REE silicates, phosphates and (fluoro)carbonates, and (2) calcite-allanite with accessory REE-bearing phosphate and (fluoro)carbonate minerals that vein and brecciate the earlier stage. The veins are locally accompanied by narrow skarn-like (garnet-diopside-amphibole) wall rock alteration zones. SHRIMP Th-Pb analyses of allanite yielded an age of 1525 ± 18 Ma, interpreted as the minimum age of mineralisation. The maximum age is provided by a ~1550 Ma SHRIMP U-Pb age for a pegmatite that predates the fluorapatite veins. Other isotopic systems yielded ages from ~1443 to ~345 Ma, implying significant post-depositional isotopic disturbance. Calculation of initial ɛNd and 87Sr/86Sr at 1525 Ma and stable isotope data are consistent with an enriched mantle or lower crust source, although post-depositional disturbance is likely. Processes leading to formation of Nolans Bore began with north-dipping subduction along the south margin of the Aileron Province at 1820-1750 Ma, producing a metasomatised, volatile-rich, lithospheric mantle wedge. About 200 million years later, near the end of the Chewings Orogeny, this reservoir and/or the lower crust sourced alkaline low-degree partial melts which passed into the mid- and upper-crust. Fluids derived from these melts, which may have included phosphatic melts, eventually deposited the Nolans Bore fluorapatite veins due to fluid-rock interaction, cooling, depressurisation and/or fluid mixing. Owing to its size and high concentration of Th (2500 ppm), in situ radiogenic heating caused significant recrystallisation and isotopic resetting. The system finally cooled below 300 °C at ~370 Ma, possibly in response to unroofing during the Alice Springs

  9. The calculated solubility of platinum and gold in oxygen-saturated fluids and the genesis of platinum-palladium and gold mineralization in the unconformity-related uranium deposits

    NASA Astrophysics Data System (ADS)

    Jaireth, S.

    1992-01-01

    Thermodynamic calculations on the solubility of platinum and gold indicate that saline (1 m NaCl), fluids saturated with atmospheric oxygen can transport geologically realistic concentrations of platinum-group-elements (PGE), gold, and uranium as chloro-complexes. A number of calculations involving fluid-rock interaction suggest that the oxygen-saturated fluids flowing through rocks containing quartz, muscovite, kaolinite, magnetite and hematite, initially oxidize any magnetite to hematite, allowing subsequent batches of ore fluids to retain their high oxidation state. During their migration through the aquifer, the oxidizing fluids would move the oxidation-reduction interface deeper into the aquifer, leaching and redepositing platinum and gold. The redissolution of earlier precipitated platinum and gold depends on the fluid/ rock ratio and the associated increase in the oxidation state. Therefore, lowering of fluid/rock ratios and/or mixing of the oxidized fluids with a large amount of reduced fluid will precipitate uranium, PGE, and gold. It is suggested that this model can explain the genesis of gold and PGE mineralization in the unconformity-related uranium deposits of the Alligator Rivers Uranium Field in the Northern Territory, Australia.

  10. UHP kyanite eclogite associated with garnet peridotite and diamond-bearing granulite, northern Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Kotková, Jana; Janák, Marian

    2015-06-01

    Kyanite eclogites enclosed in garnet peridotites may provide important information on P-T evolution of orogenic peridotites in deep subduction and collision zones. Kyanite eclogite interlayered with garnet peridotite occurs in the borehole T-7, in the Saxothuringian basement of the northern part of the Bohemian Massif. This orogenic peridotite of mantle origin is associated with felsic granulites, which contain diamond as a consequence of deep subduction of the continental crust. Here, we report on the metamorphic evolution of kyanite eclogite, which shows a well-preserved peak-pressure mineral assemblage of garnet, omphacite, kyanite and phengite. Conventional geothermobarometry, average PT method and thermodynamic modelling constrain the metamorphic conditions of this assemblage up to 3.5-4.5 GPa at 900-1050 °C. Two compositional types of garnet, i.e., Mg-rich and Ca-rich, have been recognised. Thermodynamic modelling shows that the composition of Ca-rich garnet with XCa (0.35-0.37) in the core corresponds to stability of garnet at 3.5-4.5 GPa. Amphibole and zoisite are preserved as inclusions in garnet cores, and they are stable below 2.5 GPa, indicating that garnet grew at the expense of these phases at increasing P-T conditions during the prograde evolution of the rock. A post-peak metamorphism decompression and cooling are recorded by decrease of Ca-Eskola end-member in omphacite, drop in XMg and XGrs at garnet rim and a very restricted formation of pargasitic amphibole in the matrix. The absence of symplectites after omphacite in the investigated eclogite may be due to a very low content of quartz and possibly also fluid in the rock. Our study suggests that kyanite-bearing eclogite underwent UHP metamorphism as a consequence of subduction, together with interlayered garnet peridotite. Both rocks were incorporated into the subducted continental crust (diamond-bearing granulites) during the Variscan orogeny.

  11. Low pressure granulites from the Bohemian Massif, Upper Austria

    NASA Astrophysics Data System (ADS)

    Sorger, Dominik; Daghighi, Donia; Simic, Katica; Pichler, Ruth; Schwaiger, Christian; Hauzenberger, Christoph; Linner, Manfred; Iglseder, Christoph

    2014-05-01

    Low pressure granulite facies rocks are commonly found in the Bohemian Massif in Upper Austria. They belong to the Moldanubian Unit and were metamorphosed during the last stage of the Variscan orogeny. The investigated granulites from the Donau valley (west of Linz), Lichtenberg (northwest of Linz), Sauwald (south of the river Danube) and Bad Leonfelden zone comprise mainly migmatic paragneisses. Most of these rocks underwent high degrees of melting forming meta- and diatexites (''Perlgneise)''. Al-rich metapelites with partly cm-sized garnet porphyroblasts, which are suitable for precise PT and PT-path determinations, can be found in some localities of this unit. In this study samples taken along the Danube valley between Linz and Wilhering, from Lichtenberg and from Bad Leonfelden (north of Linz) were sampled and investigated petrographically in detail. Since garnets are rare and usually consumed by cordierite, a sample with large garnets was investigated in detail. A chemical zoning profile across the c. 1cm large garnet displayed elevated Ca contents (Xgrs=0.06) in the central part which decreased discontinuously towards the rim to Xgrs=0.02. Almandine, pyrope and spessartine components do not show any pronounced zoning pattern. Most of the smaller garnet grains in other samples are also homogeneous in composition with a slight Xalm increase and Xprp decrease at the rims, typical for retrograde diffusional zoning. The cordierite-garnet-sillimanite-granulites as well as some mafic granulites were used for geothermobarometry. Metamorphic conditions of around 770°C to 850°C and 0.5-0.6 GPa could be obtained, which are similar to the values obtained by Tropper et al. (2006). P. Tropper I. Deibl F. Finger R. Kaindl (2006). P-T-t evolution of spinel-cordierite-garnet gneisses from the Sauwald Zone (Southern Bohemian Massif, Upper Austria): is there evidence for two independent late-Variscan low-P / high-T events in the Moldanubian Unit? Int J Earth Sci (Geol

  12. The performance of functional methods for correcting non-Gaussian measurement error within Poisson regression: corrected excess risk of lung cancer mortality in relation to radon exposure among French uranium miners.

    PubMed

    Allodji, Rodrigue S; Thiébaut, Anne C M; Leuraud, Klervi; Rage, Estelle; Henry, Stéphane; Laurier, Dominique; Bénichou, Jacques

    2012-12-30

    A broad variety of methods for measurement error (ME) correction have been developed, but these methods have rarely been applied possibly because their ability to correct ME is poorly understood. We carried out a simulation study to assess the performance of three error-correction methods: two variants of regression calibration (the substitution method and the estimation calibration method) and the simulation extrapolation (SIMEX) method. Features of the simulated cohorts were borrowed from the French Uranium Miners' Cohort in which exposure to radon had been documented from 1946 to 1999. In the absence of ME correction, we observed a severe attenuation of the true effect of radon exposure, with a negative relative bias of the order of 60% on the excess relative risk of lung cancer death. In the main scenario considered, that is, when ME characteristics previously determined as most plausible from the French Uranium Miners' Cohort were used both to generate exposure data and to correct for ME at the analysis stage, all three error-correction methods showed a noticeable but partial reduction of the attenuation bias, with a slight advantage for the SIMEX method. However, the performance of the three correction methods highly depended on the accurate determination of the characteristics of ME. In particular, we encountered severe overestimation in some scenarios with the SIMEX method, and we observed lack of correction with the three methods in some other scenarios. For illustration, we also applied and compared the proposed methods on the real data set from the French Uranium Miners' Cohort study. PMID:22996087

  13. Bohemian circular structure, Czechoslovakia: Search for the impact evidence

    NASA Technical Reports Server (NTRS)

    Rajlich, Petr

    1992-01-01

    Test of the impact hypothesis for the origin of the circular, 260-km-diameter structure of the Bohemian Massif led to the discovery of glasses and breccias in the Upper Proterozoic sequence that can be compared to autogeneous breccias of larger craters. The black recrystallized glass contains small exsolution crystals of albite-oligoclase and biotite, regularly dispersed in the matrix recrystallized to quartz. The occurrence of these rocks is limited to a 1-sq-km area. It is directly underlain by the breccia of the pelitic and silty rocks cemented by the melted matrix, found on several tens of square kilometers. The melt has the same chemistry as rock fragments in major and in trace elements. It is slightly impoverished in water. The proportion of melted rocks to fragments varies from 1:5 to 10:1. The mineralogy of melt viens is the function of later, mostly contact metamorphism. On the contact of granitic plutons it abounds on sillimanite, cordierite, and small bullets of ilmenite. Immediately on the contact with syenodiorites it contains garnets. The metamorphism of the impact rock melt seems the most probable explanation of the mineralogy and the dry total fusion of rocks accompanied by the strong fragmentation. Other aspects of this investigation are discussed.

  14. The Freyenstein Shear Zone - Implications for exhumation of the South Bohemian Batholith (Moldanubian Superunit, Strudengau, Austria)

    NASA Astrophysics Data System (ADS)

    Griesmeier, Gerit; Iglseder, Christoph; Konstantin, Petrakakis

    2016-04-01

    The Moldanubian superunit is part of the internal zone of the Variscan Orogen in Europe and borders on the Saxothuringian and Sudetes zones in the north. In the south, it is blanketed by the Alpine foreland molasse. Tectonically it is subdivided into the Moldanubian Nappes (MN), the South Bohemian Batholith (SBB) and the Bavarian Nappes. This work describes the ~ 500 m thick Freyenstein shear zone, which is located at the southern border of the Bohemian Massif north and south of the Danube near Freyenstein (Strudengau, Lower Austria). The area is built up by granites of Weinsberg-type, which are interlayered by numerous dikes and paragneisses of the Ostrong nappe system. These dikes include medium grained granites and finegrained granites (Mauthausen-type granites), which form huge intrusions. In addition, smaller intrusions of dark, finegrained diorites und aplitic dikes are observed. These rocks are affected by the Freyenstein shear zone und ductily deformed. Highly deformed pegmatoides containing white mica crystals up to one cm cut through the deformed rocks and form the last dike generation. The Freyenstein shear zone is a NE-SW striking shear zone at the eastern edge of the SBB. The mylonitic foliation is dipping to the SE with angles around 60°. Shear-sense criteria like clast geometries, SĆ structures as well as microstructures show normal faulting top to S/SW with steep (ca. 50°) angles. The Freyenstein shear zone records a polyphase history of deformation and crystallization: In a first phase, mylonitized mineral assemblages in deformed granitoides can be observed, which consist of pre- to syntectonic muscovite-porphyroclasts and biotite as well as dynamically recrystallized potassium feldspar, plagioclase and quartz. The muscovite porphyroclasts often form mica fishes and show top to S/SW directed shear-sense. The lack of syntectonic chlorite crystals points to metamorphic conditions of lower amphibolite-facies > than 450° C. In a later stage fluid

  15. Mineral bioprocessing

    SciTech Connect

    Torma, A.E.

    1993-05-01

    In the last 25 years, the introduction of biotechnological methods in hydrometallurgy has created new opportunities and challenges for the mineral processing industry. This was especially true for the production of metal values from mining wastes and low-and-complex-grade mineral resources, which were considered economically not amenable for processing by conventional extraction methods. Using bio-assisted heap, dump and in-situ leaching technologies, copper and uranium extractions gained their first industrial applications. The precious metal industries were the next to adopt the bio-preoxidation technique in the extraction of gold from refractory sulfide-bearing ores and concentrates. A variety of other bioleaching opportunities exist for nickel, cobalt, cadmium and zinc sulfide leaching. Recently developed bioremediation methods and biosorption technologies have shown a good potential for industrial applications to remove trace heavy metal and radionuclide concentrations from contaminated soils, and mining and processing effluents.

  16. Recent geodynamic pattern of the eastern part of the Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Schenk, V.; Schenková, Z.; Grácová, M.

    2009-04-01

    The Bohemian Massif, a Precambrian cratonic terrane, had been affected by several orogeneses forming its tectonic pattern. To detect the recent geodynamic motions going on fundamental geological structures of the Massif four regional geodynamic networks were established for epoch GPS measurements and one countrywide GEONAS network for permanent GPS satellite signals monitoring. In the east part of the Bohemian Massif sinistral movements on the Sudetic NW-SE faults and as well on the NNE-SSW faults of the Moravo-Silesian tectonic system have been detected. The sinistral trends dominate on many faults situated close to the contact of the Moldanuabian and Lugian parts and the Moravo-Silesian part of the Bohemian Massif. Because of tectonic systems intersections an existence of dextral movements cannot be excluded. Additional analyses displayed that eastern part of the Massif could be under extending trends. The preliminary site velocities assessed from GPS data for the eastern part of the Bohemian Massif are discussed from a viewpoint of regional geological structure motions. The work was supported by the Grant Agency of the Academy of Sciences of the Czech Republic (Project IAA300460507), the Targeted Research Programme of the Academy of Sciences of the CR (1QS300460551) and by the Ministry of Education, Youth and Sport of the Czech Republic (Projects LC506 and 1P05ME781).

  17. A Treasure Chest of Nanogranites: the Bohemian Massif (Central Europe)

    NASA Astrophysics Data System (ADS)

    Ferrero, S.; O'Brien, P. J.; Walczak, K.; Wunder, B.; Ziemann, M. A.; Hecht, L.

    2014-12-01

    Despite 150 years of investigation of the Bohemian Massif (Central Europe), it is only recently that the investigation of old and new samples displayed the occurrence of tiny portions of crystallized anatectic melt in regional migmatites. These vestiges of magma, called "nanogranites", are natural probes of the partial melting processes in the crust. Original melt composition and water content can be directly analyzed after piston cylinder re-homogenization. When compared to classic re-melting experiments, nanogranites are ideal "natural" experimental charges of anatectic melt. They are encapsulated in peritectic garnet immediately after production - both phases are products of the same partial melting reaction. Sheltered inside garnet, they remain unaffected by the physico-chemical changes which affected the host migmatites during their slow cooling, unlike leucosomes and anatexis-related plutons. Five different case studies of nanogranite-bearing high-grade rocks have been identified so far: three in metapelites from the Moldanubian Zone, and two in metagranitoids from the Granulitgebirge and Orlica-Śnieżnik Dome. Their characterization provides insights into how the continental crust melts at different depths, from shallow levels to mantle depths, during different moments of its metamorphic history (prograde vs. decompressional melting). For example, the investigation and experimental re-melting of nanogranites from Grt+Ky leucogranulites (Orlica-Śnieżnik Dome) recently provided evidence of prograde melting of metagranitoids under eclogite-facies conditions (T≥875°C and P~2.7 GPa), close to the stability field of coesite. The melt generated is granitic, hydrous (6 wt% H2O) and metaluminous (ASI=1.03), and is at the moment the "deepest" glass obtained through re-homogenization of primary polycrystalline inclusions in natural rocks. This work confirms that nanogranites in migmatites 1) are a powerful tool to constrain anatexis in natural rocks, and 2) can

  18. Preliminary report on the use of LANDSAT-1 (ERTS-1) reflectance data in locating alteration zones associated with uranium mineralization near Cameron, Arizona

    USGS Publications Warehouse

    Spirakis, Charles S.; Condit, Christopher D.

    1975-01-01

    LANDSAT-I (ERTS-I) multispectral reflectance data were used to enhance the detection of alteration around uranium deposits near Cameron, Ariz. The technique involved stretching and ratioing computer-enhanced data from which electronic noise and atmospheric haze had been removed. Using present techniques, the work proves that LANDSAT-I data are useful in detecting alteration around uranium deposits, but the method may still be improved. Bluish-gray mudstone in the target area could not be differentiated from the altered zones on the ratioed images. Further experiments involving combinations of ratioed and nonratioed data will be required to uniquely define the altered zones.

  19. Uranium: A Dentist's perspective

    PubMed Central

    Toor, R. S. S.; Brar, G. S.

    2012-01-01

    Uranium is a naturally occurring radionuclide found in granite and other mineral deposits. In its natural state, it consists of three isotopes (U-234, U-235 and U-238). On an average, 1% – 2% of ingested uranium is absorbed in the gastrointestinal tract in adults. The absorbed uranium rapidly enters the bloodstream and forms a diffusible ionic uranyl hydrogen carbonate complex (UO2HCO3+) which is in equilibrium with a nondiffusible uranyl albumin complex. In the skeleton, the uranyl ion replaces calcium in the hydroxyapatite complex of the bone crystal. Although in North India, there is a risk of radiological toxicity from orally ingested natural uranium, the principal health effects are chemical toxicity. The skeleton and kidney are the primary sites of uranium accumulation. Acute high dose of uranyl nitrate delays tooth eruption, and mandibular growth and development, probably due to its effect on target cells. Based on all previous research and recommendations, the role of a dentist is to educate the masses about the adverse effects of uranium on the overall as well as the dental health. The authors recommended that apart from the discontinuation of the addition of uranium to porcelain, the Public community water supplies must also comply with the Environmental Protection Agency (EPA) standards of uranium levels being not more than 30 ppb (parts per billion). PMID:24478959

  20. Decorative marbles from the Krkonoše-Jizera Terrane (Bohemian Massif, Czech Republic): provenance criteria

    NASA Astrophysics Data System (ADS)

    Šťastná, Aneta; Přikryl, Richard

    2009-03-01

    Marbles from western part of the Krkonoše-Jizera Terrane (northern part of the Bohemian Massif) have been studied to obtain mineropetrographic and chemical reference data for provenance studies. Samples from six different quarries were analysed by mineralogical-petrographic and geochemical methods (optical microscopy, X-ray diffraction, stable isotope ratio analysis, cathodoluminescence, bulk magnetic susceptibility). Petrographic characteristics permit a distinction between fine-grained to medium-grained marbles from the Jizera Mts (amphibolite metamorphic facies) and fine-grained marbles from the Ještěd Mts (low-grade greenschist facies). The samples studied are mainly calcitic, with the exception of those from Raspenava in which dolomite is abundant in two types. The mineralogical composition of the insoluble residues is clinochlore ± serpentine ± tremolite ± diopside ± pyrite + magnetite in case of the locality Raspenava and clinochlore + muscovite ± quartz ± pyrite ± rutile ± haematite in case of the localities from the Ještěd Mts. δ13C and δ18O variations in primary and secondary carbonate phases allow to distinguish genetically different carbonate veins and permit quarry separation in one case (Raspenava, Jizera Mts). The δ13C and δ18O values of the groundmass range from -1 to +3‰ and from -8 to -20‰ (PDB), respectively. The δ13C and δ18O values of secondary carbonate veins decrease to -3‰ and reach more negative values up to -26‰ in case of δ18O. The fabric of cathodomicrofacies allows the distinction between calcite and dolomite, except three localities (Pilínkov, Horní Hanychov, Jitrava—rose type) with majority of quenchers (high content of iron in carbonate). The genetically different calcite is characterised by a pale and dark orange luminescence distribution. Serpentine, tremolite, forsterite, opaque minerals and quartz have no luminescence and very dull luminescence, respectively. The majority of studied marbles

  1. The Leyden uranium prospect, Jefferson County, Colorado

    USGS Publications Warehouse

    Gott, Garland B.

    1950-01-01

    The Leyden uranium prospect is in sec. 28, T, 2 S., R. 70 W, Jefferson County, Cplo, Examination of the property was made in February 1950. Uranium was first reported in this locality in 1875 by Captain E. L. Berthoud, who noted uranium minerals associated with the main coal bed. The Old Leyden coal mine workings have long been abandoned and caved, but specimens of the uranium-bearing rock can be seen on the old dump 700 feet to the south. The mineralized coal bed is 10 to 12 feet thick and occurs near the base of the Laramie formation of Upper Cretaceous age. Uranium minerals are present in the form of yellow incrustations and inclusions in fractured and partly silicified coal. Petrographic studies indicate that the silica and uranium minerals were deposited after deposition and carbonization of the coal. Secondary uranium minerals also were found by C. R. Butler along the outcrop of the sandstones in the Laramie formation. No uranium minerals were found in place by the writer, but four samples from the dump contained 0.001, 0,005, 0.17 and 0.69 percent uranium.

  2. 1996 annual report on Alaska's mineral resources

    USGS Publications Warehouse

    Schneider, Jill L.

    1997-01-01

    This is the fifteenth annual report that has been prepared in response to the Alaska National Interest Lands Conservation Act. Current Alaskan mineral projects and events that occurred during 1995 are summarized. For the purpose of this document, the term 'minerals' encompasses both energy resources (oil and gas, coal and peat, uranium, and geothermal) and nonfuel-mineral resources (metallic and industrial minerals).

  3. Crustal structure of the Bohemian Massif in the light of seismic refraction data

    NASA Astrophysics Data System (ADS)

    Hrubcova, Pavla

    2010-05-01

    The Bohemian Massif is one of the largest stable outcrops of pre-Permian rocks in Central and Western Europe. It forms the easternmost part of the Variscan Belt, which developed approximately between 500 and 250 Ma during a stage of large-scale crustal convergence, collision of continental plates and microplates, and possibly also subduction. It consists mainly of low- to high-grade metamorphic and plutonic Palaeozoic rocks. The area of the Bohemian Massif can be subdivided into various tectonostratigraphic units separated by faults, shear zones or thrusts trending roughly in a SW-NE direction, and reflecting varying influence of the Cadomian and Variscan orogenies: the Saxothuringian, Teplá-Barrandian, Moldanubian and Moravo-Silesian. Geographically, it comprises the area of the Czech Republic, partly Austria, Germany and Poland. While the post-collisional history of the Variscan Bohemian Massif is relatively clear, the kinematics of plate movements before and during collision is still subject of debates. To investigate such a complex structure, the Bohemian Massif has been covered by a network of seismic experiments as a result of a massive international cooperative effort in central Europe. Detailed analyses of the data from the main profiles of the CELEBRATION 2000, ALP 2002, and SUDETES 2003 refraction and wide-angle reflection seismic experiments show crustal and uppermost mantle structure of the massif and delimit the continuation of various tectonic units in depth. The differences in seismic velocities reflect, to some extent, the structural variances and give some indications for tracing of crust-forming processes during individual tectonic events. Lower crust in the Saxothuringian exhibits complicated structure, ranging from a highly reflective lower crustal layer above Moho with a strong velocity contrast at the top of this layer. Another possible explanation can be a double Moho or the Moho with some lateral topography. This complicated lower crust

  4. Significance of the effect of mineral alteration of nuclide migration

    SciTech Connect

    Murakami, Takashi; Ohnuki, Toshihiko; Isobe, Hiroshi; Sato, Tsutomu; Yanase, Nobuyuki; Kimura, Hideo

    1994-12-31

    In order to clarify the effect of mineral alteration on nuclide migration, we examined the processes, mechanisms, and kinetics of chlorite weathering, and the uranium concentrations in minerals and rocks at Koongarra, Australia. The observed concentrations of uranium in rocks were compared to those calculated. The sequence of chlorite weathering may be simply expressed as a chlorite {yields} vermiculite {yields} kaolinite conversion. These minerals occur as a function of depth, which corresponds well to uranium concentrations on the meter scale. Iron minerals, closely related to the uranium redistribution, are released during the weathering. The first-order kinetic model of the weathering process suggests that the weathering rate is not constant but time-dependent. The uranium concentrations are qualitatively proportional to the extent of the weathering, the weathered part having higher uranium concentration. Uranium mainly occurs with iron minerals, and sub micron sized saleeite, a uranyl phosphate, is one of the most probable uranyl phases associated with the iron minerals. The uranium fixation mechanisms are probably saleeite microcrystal coprecipitation and sorption to the iron minerals. Our model, which describes uranium concentrations in rocks as a function of time, shows that the transition zone (a vermiculite dominant area) plays an important role in the uranium migration. We have established that weathering of chlorite has affected the redistribution of uranium for more than one million years. The present study demonstrates the significance of mineral alteration when we estimate nuclide migration for geologic time.

  5. Significance of Geological Units of the Bohemian Massif, Czech Republic, as Seen by Ambient Noise Interferometry

    NASA Astrophysics Data System (ADS)

    Růžek, Bohuslav; Valentová, Lubica; Gallovič, František

    2016-05-01

    Broadband recordings of 88 seismic stations distributed in the Bohemian Massif, Czech Republic, and covering the time period of up to 12 years were processed by a cross-correlation technique. All correlograms were analyzed by a novel approach to get both group and phase dispersion of Rayleigh and Love waves. Individual dispersion curves were averaged in five distinct geological units which constitute the Bohemian Massif (Saxothuringian, Teplá-Barrandean, Sudetes, Moravo-Silesian, and Moldanubian). Estimated error of the averaged dispersion curves are by an order smaller than the inherent variability due to the 3D distribution of seismic velocities within the units. The averaged dispersion data were inverted for 1D layered velocity models including their uncertainty, which are characteristic for each of the geological unit. We found that, overall, the differences between the inverted velocity models are of similar order as the variability inside the geological units, suggesting that the geological specification of the units is not fully reflected into the S-wave propagation velocities on a regional scale. Nevertheless, careful treatment of the dispersion data allowed us to identify some robust characteristics of the area. The vp to vs ratio is anomalously low (~1.6) for all the units. The Moldanubian is the most rigid and most homogeneous part of the Bohemian Massif. Middle crust in the depth range of ~3-15 km is relatively homogeneous across the investigated region, while both uppermost horizon (0-3 km) and lower crust (>15 km) exhibit lower degree of homogeneity.

  6. Uraniferous bitumen nodules in the Talvivaara Ni-Zn-Cu-Co deposit (Finland): influence of metamorphism on uranium mineralization in black shales

    NASA Astrophysics Data System (ADS)

    Lecomte, Andreï; Cathelineau, Michel; Deloule, Etienne; Brouand, Marc; Peiffert, Chantal; Loukola-Ruskeeniemi, Kirsti; Pohjolainen, Esa; Lahtinen, Hannu

    2014-04-01

    In the central part of the Fennoscandian Shield, the Talvivaara Ni-Zn-Cu-Co deposit, hosted by Palaeoproterozoic metamorphosed black schists, contains low uranium concentrations ranging from 10 to 30 ppm. The Talvivaara black schists were deposited 2.0-1.9 Ga ago and underwent subsequent metamorphism during the 1.9-1.79 Ga Svecofennian orogeny. Anhedral uraninite crystals rimmed by bitumen constitute the main host of uranium. U-Pb secondary ion mass spectrometry dating indicates that uraninite crystals were formed between 1,878 ± 17 and 1,871 ± 43 Ma, during peak metamorphism. Rare earth element patterns and high Th content (average 6.38 wt%) in disseminated uraninite crystals indicate that U was concentrated during high temperature metamorphism (>400 °C). The formation of bitumen rims around uraninite may be explained by two distinct scenarios: (a) a transport of U coincident with the migration of hydrocarbons or (b) post-metamorphic formation of bitumen rims, through radiolytic polymerization of gaseous hydrocarbons at the contact with uraninite.

  7. P T and fluid evolution of barren and lithium pegmatites from Vlastějovice, Bohemian Massif, Czech Republic

    NASA Astrophysics Data System (ADS)

    Ackerman, Lukáš; Zachariáš, Jiří; Pudilová, Marta

    2007-08-01

    Fluid inclusions, mineral thermometry and stable isotope data from two types of mineralogically and texturally contrasting pegmatites, barren ones and lithium ones, from the Moldanubian Zone of the Bohemian Massif were studied in order to constrain P T conditions of their emplacement, subsolidus hydrothermal evolution and to estimate composition of the early exsolved fluid and that of the parental melt. Despite the fact that the lithium pegmatites are abundant throughout the crystalline units of the Bohemian Massif, data similar to this paper have not been published yet. The studied pegmatites are hosted by iron-rich calcic skarn bodies. This specific setting allowed scavenging of calcium, fluorine and some other elements from the host rocks into the pegmatitic melts and post-magmatic fluids. Such contamination process was important namely in the case of barren pegmatites, as can be deduced from the variation in anorthite contents in plagioclase and from the presence of fluorite, hornblende (with F content) or garnet in the contact zones of pegmatite dykes. Fluid inclusions were studied mostly in quartz, but also in fluorite, titanite and apatite. Early aqueous carbonic and late aqueous fluids were identified in both pegmatite types. The P T conditions of crystallization as well as the detailed composition of exsolved magmatic fluid, however, particularly differ. The magmatic fluids associated with barren pegmatites correspond to H2O CO2 low salinity fluids, composition of which evolved from 20 to 23 to <5 mol% CO2, and from 2 to 4 6 mol% NaCl eq. Sudden decrease in the CO2 content of the post-magmatic fluids (<5 mol% CO2) seems to coincide with the enrichment of the fluid in calcium (from the contamination process) and resulted in precipitation of calcites (frequently found as trapped solid phases in fluid inclusions). The fluids associated with lithium pegmatites are more complex (H2O CO2/N2 H3BO3 NaCl). The CO2 content of early exsolved fluid is 26 20 mol% CO2

  8. Monazite and zircon as major carriers of Th, U, and Y in peraluminous granites: examples from the Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Breiter, Karel

    2016-06-01

    The chemical compositions of zircon and monazite and the relationships between the contents of Th, U, Y, and REE in both minerals and in the bulk samples of their parental rocks were studied in three Variscan composite peraluminous granite plutons in the Bohemian Massif. It was established that granites of similar bulk composition contain zircon and monazite of significantly different chemistry. Monazite typically contains 5-13 wt% (rarely up to 28 wt%) ThO2, 0.4-2 wt% (up to 8.2 wt%) UO2, and 0.5-2 wt% (up to 5 wt%) Y2O3, whereas zircon typically contains less than 0.1 wt% (rarely up to 1.7 wt%) ThO2, less than 1 wt% UO2 (in the Plechý/Plockenstein granite, commonly, 1-2 wt% and scarcely up to 4.8 wt% UO2), and less than 1 wt% Y2O3 (in the Nejdek pluton often 2-5, maximally 7 wt% Y2O3). Monazite is an essential carrier of thorium, hosting more than 80 % of Th in all studied granites. Monazite also appears to be an important carrier of Y (typically 14-16 %, and in the Melechov pluton, up to 81 % of the total rock content) and U (typically 18-35 % and occasionally 6-60 % of the total rock budget). The importance of zircon for the rock budget of all the investigated elements in granites is lower: 4-26 % U, 5-17 % Y, and less than 5 % Th.

  9. Two Lithologies in Lithospheric Mantle Beneath Nothern Margin of the Bohemian Massif (e Germany and SW Poland).

    NASA Astrophysics Data System (ADS)

    Matusiak-Małek, Magdalena; Puziewicz, Jacek; Ntaflos, Theodoros; Kukuła, Anna; Ćwiek, Mateusz

    2014-05-01

    The subcontinental lithospheric mantle (SCLM) occurring beneath Bohemian Massif in Central Europe has been sampled in Cenozoic times by numerous lavas. Recent studies (Puziewicz et al. 2011 and references therein) show that mantle in this region is mostly anhydrous, harzburgitic, and was subjected to various kinds of metasomatic events. Two major mantle lithologies characterized by different major element composition of peridotite- forming minerals occur in the SCLM Lower Silesia and Lusatia (op. cit. and unpublished results, 9 sites). Lithology "A" (minimal temperatures from 900 to 1000ºC or no equilibrium between cpx and opx) contains olivine Fo90.5 -92.0. Part of the population "A" peridotites contain clinopyroxene of mg# 94 - 95, typical for low temperatures of equilibration. The lithology "B" (equilibration temperatures close to 900 ºC) contains olivine Fo87.5-90.0. Elevated contents of LREE in clinopyroxene from both the lithologies "A" and "B" suggest their equilibration with one of the two metasomatic agents stated in this area: anhydrous silicate alkaline melt or carbonatite-silicate melt. Action of hydrous alkaline melts in the mantle in the region is recorded only locally (e.g. Wilcza Góra). In some sites (e.g. Krzeniów) the trace element patterns show that decreasing mg# of clinopyroxene in the "A" peridotites is due to gradual replacement of primary lower-temperature mineral assemblage by the later higher-temperature one. This suggests that the variation of mineral chemistry is rather due to chromatographic fractionation of metasomatic agents than due to vertical variation in lithospheric mantle temperatures (Christensen et al.,2001). The "B" peridotites originated due to "Fe-metasomatism" of more magnesian peridotites by silicate melts percolating through lithospheric mantle. The peridotites belonging to lithology "A" might have been partly the protolith of the lithology "B". The data on Central European lithospheric mantle are equivocal and thus

  10. Solubility measurement of uranium in uranium-contaminated soils

    SciTech Connect

    Lee, S.Y.; Elless, M.; Hoffman, F.

    1993-08-01

    A short-term equilibration study involving two uranium-contaminated soils at the Fernald site was conducted as part of the In Situ Remediation Integrated Program. The goal of this study is to predict the behavior of uranium during on-site remediation of these soils. Geochemical modeling was performed on the aqueous species dissolved from these soils following the equilibration study to predict the on-site uranium leaching and transport processes. The soluble levels of total uranium, calcium, magnesium, and carbonate increased continually for the first four weeks. After the first four weeks, these components either reached a steady-state equilibrium or continued linearity throughout the study. Aluminum, potassium, and iron, reached a steady-state concentration within three days. Silica levels approximated the predicted solubility of quartz throughout the study. A much higher level of dissolved uranium was observed in the soil contaminated from spillage of uranium-laden solvents and process effluents than in the soil contaminated from settling of airborne uranium particles ejected from the nearby incinerator. The high levels observed for soluble calcium, magnesium, and bicarbonate are probably the result of magnesium and/or calcium carbonate minerals dissolving in these soils. Geochemical modeling confirms that the uranyl-carbonate complexes are the most stable and dominant in these solutions. The use of carbonate minerals on these soils for erosion control and road construction activities contributes to the leaching of uranium from contaminated soil particles. Dissolved carbonates promote uranium solubility, forming highly mobile anionic species. Mobile uranium species are contaminating the groundwater underlying these soils. The development of a site-specific remediation technology is urgently needed for the FEMP site.

  11. URANIUM RECOVERY

    DOEpatents

    Fitch, F.T.; Cruikshank, A.J.

    1958-10-28

    A process for recovering uranium from a solution of a diethyl dithiocarbaruate of uranium in an orgakic solvent substantially immiscible with water is presented. The process comprises brlnging the organic solutlon into intimate contact wlth an aqueous solution of ammonium carbonate, whereby the uranium passes to the aqueous carbonate solution as a soluble uranyl carbonate.

  12. The Uranium Resource: A Comparative Analysis

    SciTech Connect

    Schneider, Erich A.; Sailor, William C.

    2007-07-01

    An analogy was drawn between uranium and thirty five minerals for which the USGS maintains extensive records. The USGS mineral price data, which extends from 1900 to the present, was used to create a simple model describing long term price evolution. Making the assumption that the price of uranium, a geologically unexceptional mineral, will evolve in a manner similar to that of the USGS minerals, the model was used to project its price trend for this century. Based upon the precedent set by the USGS data, there is an 80% likelihood that the price of uranium will decline. Moreover, the most likely scenario would see the equilibrium price of uranium decline by about 40% by mid-century. (authors)

  13. Reactivity of North Bohemian coals in coprocessing of coal/oil mixtures

    SciTech Connect

    Sebor, G.; Cerny, J.; Maxa, D.; Blazek, J.; Sykorova, I.

    1995-12-01

    Autoclave experiments with North Bohemian coal were done in order to evaluate their reactivity in coprocessing with petroleum vacuum residue, Selected coals were comprehensively characterized by using a number of analytical methods. While the coals were of similar geological origin, some of their characteristics differed largely from one coal to another. Despite the differences in physical and chemical structure, the coals provided very similar yields of desired reaction products. The yields of a heavy non- distillable fraction and/or an insoluble solid residue were, under experimental conditions, largely affected by retrogressive reactions (coking). The insoluble solid fractions were examined microscopically under polarized light.

  14. Effects of clay minerals and organic matter in formulated sediments on the bioavailability of sediment-associated uranium to the freshwater midge, Chironomus dilutus.

    PubMed

    Crawford, Sarah E; Liber, Karsten

    2015-11-01

    It is well established that bioavailability influences metal toxicity in aquatic ecosystems. However, the factors and mechanisms that influence uranium (U) bioavailability and toxicity in sediment have not been thoroughly evaluated, despite evidence that suggests different sediment components can influence the sorption and interaction of some metals. Given that dissolved U is generally accepted as being the primary bioavailable fraction of U, it is hypothesized that adsorption and interaction of U with different sediment components will influence the bioavailability of U in sediment. We investigated the effects of key sediment physicochemical properties on the bioavailability of U to a model freshwater benthic invertebrate, Chironomus dilutus. Several 10-day spiked sediment bioaccumulation experiments were performed, exposing C. dilutus larvae to a variety of formulated sediments spiked with different concentrations of U (5, 50 and/or 200 mg U/kg d.w.). Mean accumulation of U in C. dilutus larvae decreased significantly from 1195 to 10 mg U/kg d.w. as kaolin clay content increased from 0% to 60% in sediment spiked with 50 mg U/kg d.w. Similarly, higher organic matter content also resulted in a significant reduction of U bioaccumulation in C. dilutus larvae, indicating a reduction in U bioavailability. Concentrations of U in both the overlying water and sediment pore water displayed a strong positive relationship to U bioaccumulation in C. dilutus larvae (r(2) = 0.77, p<0.001 and r(2) = 0.57, p < 0.001, respectively) for all experiments, while total U concentrations in the sediment had a poor relationship to U bioaccumulation (r(2) = 0.10, p = 0.028). Results from this research confirm that sediment clay and organic matter content play a significant role in altering U bioavailability, which is important in informing risk assessments of U contaminated sites and in the development of site-specific sediment quality guidelines for U. PMID:26205073

  15. Variations in the uranium isotopic compositions of uranium ores from different types of uranium deposits

    NASA Astrophysics Data System (ADS)

    Uvarova, Yulia A.; Kyser, T. Kurt; Geagea, Majdi Lahd; Chipley, Don

    2014-12-01

    Variations in 238U/235U and 234U/238U ratios were measured in uranium minerals from a spectrum of uranium deposit types, as well as diagenetic phosphates in uranium-rich basins and peraluminous rhyolites and associated autunite mineralisation from Macusani Meseta, Peru. Mean δ238U values of uranium minerals relative to NBL CRM 112-A are 0.02‰ for metasomatic deposits, 0.16‰ for intrusive, 0.18‰ for calcrete, 0.18‰ for volcanic, 0.29‰ for quartz-pebble conglomerate, 0.29‰ for sandstone-hosted, 0.44‰ for unconformity-type, and 0.56‰ for vein, with a total range in δ238U values from -0.30‰ to 1.52‰. Uranium mineralisation associated with igneous systems, including low-temperature calcretes that are sourced from U-rich minerals in igneous systems, have low δ238U values of ca. 0.1‰, near those of their igneous sources, whereas uranium minerals in basin-hosted deposits have higher and more variable values. High-grade unconformity-related deposits have δ238U values around 0.2‰, whereas lower grade unconformity-type deposits in the Athabasca, Kombolgie and Otish basins have higher δ238U values. The δ234U values for most samples are around 0‰, in secular equilibrium, but some samples have δ234U values much lower or higher than 0‰ associated with addition or removal of 234U during the past 2.5 Ma. These δ238U and δ234U values suggest that there are at least two different mechanisms responsible for 238U/235U and 234U/238U variations. The 234U/238U disequilibria ratios indicate recent fluid interaction with the uranium minerals and preferential migration of 234U. Fractionation between 235U and 238U is a result of nuclear-field effects with enrichment of 238U in the reduced insoluble species (mostly UO2) and 235U in oxidised mobile species as uranyl ion, UO22+, and its complexes. Therefore, isotopic fractionation effects should be reflected in 238U/235U ratios in uranium ore minerals formed either by reduction of uranium to UO2 or chemical

  16. Modelling study on uranium migration in rocks under weathering condition

    SciTech Connect

    Ohnuki, Toshihiko; Isobe, Hiroshi; Sato, Tsutomu; Yanase, Nobuyuki; Murakami, Takashi

    1995-12-31

    A modelling study has been completed to understand the effect of rock alteration on uranium migration at the Koongarra ore deposit, Australia. The model considers the weathering process, the mechanism and rate of chlorite alteration, a major mineral of the host rock, and assumes the presence of reversible sorption sites of chlorite and the presence of reversible and irreversible sorption sites of the weathering products. One- and two-dimensional, calculated uranium concentrations were compared with those observed. Good agreement between the calculated and observed uranium concentration profiles was obtained only when an appropriate fraction of uranium is fixed to the irreversible sorption sites of Fe-minerals produced during weathering of chlorite. On the other hand, the conventional Kd model failed to estimate an adequate uranium concentration profile. The results suggest that the fixation of uranium to Fe-minerals has dominated the migration of uranium in the vicinity of the Koongarra ore deposit.

  17. Electron microprobe mineral analysis guide

    NASA Technical Reports Server (NTRS)

    Brown, R. W.

    1980-01-01

    Electron microprobe mineral analysis guide is a compilation of X-ray tables and spectra recorded from various mineral matrices. Spectra were obtained using electron microprobe, equipped with LiF geared, curved crystal X-ray spectrometers, utilizing typical analytical operating conditions: 15 Kv acceleration potential, 0.02 microampere sample current as measured on a clinopyroxene standard (CP19). Tables and spectra are presented for the majority of elements, fluorine through uranium, occurring in mineral samples from lunar, meteoritic and terrestrial sources. Tables for each element contain relevant analytical information, i.e., analyzing crystal, X-ray peak, background and relative intensity information, X-ray interferences and a section containing notes on the measurement. Originally intended to cover silicates and oxide minerals the tables and spectra have been expanded to cover other mineral phases. Electron microprobe mineral analysis guide is intended as a spectral base to which additional spectra can be added as the analyst encounters new mineral matrices.

  18. Mineral Deposit Data for Epigenetic Base- and Precious-metal and Uranium-thorium Deposits in South-central and Southwestern Montana and Southern and Central Idaho

    USGS Publications Warehouse

    Klein, T.L.

    2004-01-01

    Metal deposits spatially associated with the Cretaceous Boulder and Idaho batholiths of southwestern Montana and southern and central Idaho have been exploited since the early 1860s. Au was first discovered in placer deposits; exploitation of vein deposits in bedrock soon followed. In 1865, high-grade Ag vein deposits were discovered and remained economically important until the 1890s. Early high-grade deposits of Au, Ag and Pb were found in the weathered portions of the veins systems. As mining progressed to deeper levels, Ag and Pb grades diminished. Exploration for and development of these vein deposits in this area have continued until the present. A majority of these base- and precious-metal vein deposits are classified as polymetallic veins (PMV) and polymetallic carbonate-replacement (PMR) deposits in this compilation. Porphyry Cu and Mo, epithermal (Au, Ag, Hg and Sb), base- and precious-metal and W skarn, W vein, and U and Th vein deposits are also common in this area. The world-class Butte Cu porphyry and the Butte high-sulfidation Cu vein deposits are in this study area. PMV and PMR deposits are the most numerous in the region and constitute about 85% of the deposit records compiled. Several types of syngenetic/diagenetic sulfide mineral deposits in rocks of the Belt Supergroup or their equivalents are common in the region and they have been the source of a substantial metal production over the last century. These syngenetic deposits and their metamorphosed/structurally remobilized equivalents were not included in this database; therefore, deposits in the Idaho portion of the Coeur d'Alene district and the Idaho Cobalt belt, for example, have not been included because many of them are believed to be of this type.

  19. Petrological Characterization of the Triassic Paleosurface in the Northern Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Yao, Kouakou; Thiry, Medard; Szuszkiewicz, Adam; Turniak, Krzysztof

    2010-05-01

    ‘Albitization' is a widespread alteration process affecting sedimentary, igneous and metamorphic rocks. Albitized facies usually show a pinkish to red colour, depending on the degree of alteration. The main mineralogical process of this phenomenon is the pseudomorphic replacement of the primary Ca-Na plagioclases by secondary albite (Na). During this replacement biotite is often transformed to chlorite and inclusions of hematite, apatite, titanite, and calcite develop. So far, albitization has been systematically regarded as caused by magmatic derived hydrothermal brines, alkaline metasomatism reactions (Cathelineau, 1986; Petersson and Eliasson, 1997), or as a low grade metamorphic facies (Boles and Coombs, 1977). Recent studies in the Morvan Massif granites (Ricordel et al., 2007; Parcerisa et al., 2009) showed that the albitization there is related to the Triassic paleosurface. The decrease of this alteration with depth and its paleomagnetic age support the link of the albitization to the Triassic paleosurface. Furthermore, the petrographic data suggest the import of sodium by weathering solutions. The enrichement in Na+ of the fluids that triggered this alteration is probably linked to the Triassic salt deposits. Albitised pinkish facies have been recognized in the northern part of the Bohemian Massif (Polish Sudetes). Typical igneous and metamorphic rocks of the Klodzko area (southern Poland) are granites, granodiorites, schists, amphibolite, and gneisses, mostly of Paleozoic age. Three sites in the Klodzko area were sampled in detail from N to S: (1) Laski quarry, (2) Laski village, and (3) Chwalislaw. Here, the occurrence of the albitization is well developed and specific in its mineralogical paragenesis. Throughout the sample sites different albitization stages can be observed. The most albitized and therefore reddish facies can be found at the Laski village granite that consists of primary quartz and K-feldspar, biotite, and development of secondary

  20. RECOVERY OF URANIUM VALUES FROM RESIDUES

    DOEpatents

    Schaap, W.B.

    1959-08-18

    A process is described for the recovery of uranium from insoluble oxide residues resistant to repeated leaching with mineral acids. The residue is treated with gaseous hydrogen fluoride, then with hydrogen and again with hydrogen fluoride, preferably at 500 to 700 deg C, prior to the mineral acid leaching.

  1. URANIUM COMPOSITIONS

    DOEpatents

    Allen, N.P.; Grogan, J.D.

    1959-05-12

    This patent relates to high purity uranium alloys characterized by improved stability to thermal cycling and low thermal neutron absorption. The high purity uranium alloy contains less than 0.1 per cent by weight in total amount of any ore or more of the elements such as aluminum, silicon, phosphorous, tin, lead, bismuth, niobium, and zinc.

  2. Minerals yearbook: Mineral industries of Africa. Volume 3. 1992 international review

    SciTech Connect

    Not Available

    1992-01-01

    The 53 countries that constituted Africa in 1992 accounted for a significant portion of total world output of a number of mineral commodities. Among the most significant mineral commodities produced in Africa were andalusite, antimony, asbestos, bauxite, chromite, coal, cobalt, copper, diamond, fluorspar, gold, lithium minerals, manganese, phosphate, platinum-group metals, the titanium minerals-ilmenite and rutile, vanadium, vermiculite, uranium, and zircon. Chromite, cobalt, and manganese, were not mined in the Untied States.

  3. Tonalite sill emplacement at an oblique plate boundary: northeastern margin of the Bohemian Massif

    NASA Astrophysics Data System (ADS)

    Parry, Matthew; Sˇtípská, Pavla; Schulmann, Karel; Hrouda, Frantisˇek; Jezˇek, Josef; Kröner, Alfred

    1997-10-01

    A tonalitic sill has been examined at the Variscan transpressive boundary of the Lugian and Silesian plates at the NE margin of the Bohemian Massif. A structural, petrological and geochronological study reveals that it was emplaced syn-tectonically with major ductile shearing in lower crustal rocks. Magmatic and pre-rheological critical melt percentage (RCMP) fabrics are concordant with the hanging wall structures but discordant with those of the footwall. The AMS study shows the predominance of flattening strain at the margins and plane strain fabrics in the core. Numerical modelling of AMS fabrics is in good agreement with the hypothesis of magma flow and deformation in oblique transpression. A tectonic model was developed explaining emplacement and syn-tectonic deformation of progressively cooled tonalitic intrusion.

  4. Uranium phosphate biomineralization by fungi.

    PubMed

    Liang, Xinjin; Hillier, Stephen; Pendlowski, Helen; Gray, Nia; Ceci, Andrea; Gadd, Geoffrey Michael

    2015-06-01

    Geoactive soil fungi were investigated for phosphatase-mediated uranium precipitation during growth on an organic phosphorus source. Aspergillus niger and Paecilomyces javanicus were grown on modified Czapek-Dox medium amended with glycerol 2-phosphate (G2P) as sole P source and uranium nitrate. Both organisms showed reduced growth on uranium-containing media but were able to extensively precipitate uranium and phosphorus-containing minerals on hyphal surfaces, and these were identified by X-ray powder diffraction as uranyl phosphate species, including potassium uranyl phosphate hydrate (KPUO6 .3H2 O), meta-ankoleite [(K1.7 Ba0.2 )(UO2 )2 (PO4 )2 .6H2 O], uranyl phosphate hydrate [(UO2 )3 (PO4 )2 .4H2 O], meta-ankoleite (K(UO2 )(PO4 ).3H2 O), uramphite (NH4 UO2 PO4 .3H2 O) and chernikovite [(H3 O)2 (UO2 )2 (PO4 )2 .6H2 O]. Some minerals with a morphology similar to bacterial hydrogen uranyl phosphate were detected on A. niger biomass. Geochemical modelling confirmed the complexity of uranium speciation, and the presence of meta-ankoleite, uramphite and uranyl phosphate hydrate between pH 3 and 8 closely matched the experimental data, with potassium as the dominant cation. We have therefore demonstrated that fungi can precipitate U-containing phosphate biominerals when grown with an organic source of P, with the hyphal matrix serving to localize the resultant uranium minerals. The findings throw further light on potential fungal roles in U and P biogeochemistry as well as the application of these mechanisms for element recovery or bioremediation. PMID:25580878

  5. JACKETING URANIUM

    DOEpatents

    Saller, H.A.; Keeler, J.R.

    1959-07-14

    The bonding to uranium of sheathing of iron or cobalt, or nickel, or alloys thereof is described. The bonding is accomplished by electro-depositing both surfaces to be joined with a coating of silver and amalgamating or alloying the silver layer with mercury or indium. Then the silver alloy is homogenized by exerting pressure on an assembly of the uranium core and the metal jacket, reducing the area of assembly and heating the assembly to homogenize by diffusion.

  6. The East Slope No. 2 uranium prospect, Piute County, Utah

    USGS Publications Warehouse

    Wyant, Donald Gray

    1954-01-01

    The secondary uranium minerals autunite, metatorbernite, uranophane(?), and schroeckingerite occur in altered hornfels at the East Slope No. 9. uranium prospect. The deposit, in sec. 6, T. 9.7 S., R. 3 W., Piute County, Utah, is about 1 mile west of the Bullion Monarch mine which is in the central producing area of the Marysvale uranium district. Hornfels, formed by contact metamorphism of rocks of the Bullion Canyon volcanics borderhug the margin of a quartz monzonite stock, is in fault contact with the later Mount Belknap rhyolite. The hornfels was intensely altered by hydrothermal solutions in pre-Mount Belknap time. Hematite-alunite-quartz-kaolinite rock, the most completely altered hornfels, is surrounded by orange to white argillized hornfels containing beidellite-montmorillonite clay, and secondary uranium minerals. The secondary uranium minerals probably have been derived from pitchblende, the primary ore mineral in other deposits of the Marysvale area. The two uranium-rich zones, 4 feet ad 5 feet thick, have been traced on the surface for 60 feet and 110 feet, respectively. Channel samples from these zones contained as much as 0.047 percent uranium. The deposit is significant because of its position outside the central producing area and because of the association of uranium minerals with alunitic rock in hydrothermally altered hornfels of volcanic rocks of early Tertiary age.

  7. Yellow Canary uranium deposits, Daggett County, Utah

    USGS Publications Warehouse

    Wilmarth, Verl Richard

    1953-01-01

    The Yellow Canary uranium deposit is on the west side of Red Creek Canyon in the northern part of the Uinta Mountains, Daggett County, Utah. Two claims have been developed by means of an adit, three opencuts, and several hundred feet of bulldozer trenches. No uranium ore has been produced from this deposit. The deposit is in the pre-Cambrian Red Creek quartzite. This formation is composed of intercalated beds of quartzite, hornblendite, garnet schist, staurolite schist, and quartz-mica schist and is intruded by dioritic dikes. A thick unit of highly fractured white quartzite near the top of the formation contains tyuyamunite as coatings on fracture surfaces. The tyuyamunite is associated with carnotite, volborthite, iron oxides, azurite, malachite, brochantite, and hyalite. The uranium and vanadium minerals are probably alteration products of primary minerals. The uranium content of 15 samples from this property ranged from 0.000 to 0.57 percent.

  8. Tramp uranium

    SciTech Connect

    Hendrixson, E.S.; Williamson, T.G.

    1988-01-01

    Many utilities have implemented a no leaker philosophy for fuel performance and actively pursue removing leaking fuel assemblies from their reactor cores whenever a leaking fuel assembly is detected. Therefore, the only source for fission product activity in the RCS when there are no leaking fuel assemblies is tramp uranium. A technique has been developed that strips uranium impurities from ZrCl{sub 4}. Unless efforts are made to remove natural uranium impurities from reactor materials, the utilities will not be able to reduce the RCS specific {sup 131}I activity in PWRs to below the lower limit of {approximately}1.0 x 10{minus{sup 4}} {mu}Ci/g.

  9. Uranium bombs

    NASA Astrophysics Data System (ADS)

    DeGroot, Gerard

    2009-11-01

    Enrico Fermi was a brilliant physicist, but he did occasionally get things wrong. In 1934 he famously bombarded a sample of uranium with neutrons. The result was astounding: the experiment had, Fermi concluded, produced element 93, later called neptunium. The German physicist Ida Noddack, however, came to an even more spectacular conclusion, namely that Fermi had split the uranium nucleus to produce lighter elements. Noddack's friend Otto Hahn judged that idea preposterous and advised her to keep quiet, since ridicule could ruin a female physicist. She ignored that advice, and was, indeed, scorned.

  10. Uranium content and leachable fraction of fluorspars.

    PubMed

    Landa, E R; Councell, T B

    2000-09-01

    Much attention in the radiological health community has recently focused on the management and regulation of naturally occurring radioactive materials. Although uranium-bearing minerals are present in a variety of fluorspar deposits, their potential consideration as naturally occurring radioactive materials has received only limited recognition. The uranium content of 28 samples of acid- and cryolite-grade (>97% CaF2) fluorspar from the National Defense Stockpile was found to range from 120 to 24,200 microg kg(-1), with a mean of 2,145 microg kg(-1). As a point of comparison, the average concentration of uranium in the upper crust of the earth is about 2,500 microg kg(-1). Leachability of this uranium was assessed by means of the Toxicity Characteristic Leaching Procedure (TCLP). The TCLP extractable fraction ranged from 1 to 98%, with a mean of 24% of the total uranium. The typically low concentrations of uranium seen in these materials probably reflects the removal of uranium-bearing mineral phases during the beneficiation of the crude fluorspar ore to achieve industrial specifications. Future NORM studies should examine crude fluorspar ores and flotation tailings. PMID:10949254

  11. Mineral Chart

    MedlinePlus

    ... How Can I Help a Friend Who Cuts? Mineral Chart KidsHealth > For Teens > Mineral Chart Print A A A Text Size en ... sources of calcium. You'll also find this mineral in broccoli and dark green, leafy vegetables. Soy ...

  12. Mineral oils

    NASA Technical Reports Server (NTRS)

    Furby, N. W.

    1973-01-01

    The characteristics of lubricants made from mineral oils are discussed. Types and compositions of base stocks are reviewed and the product demands and compositions of typical products are outlined. Processes for commercial production of mineral oils are examined. Tables of data are included to show examples of product types and requirements. A chemical analysis of three types of mineral oils is reported.

  13. Uranium redistribution under oxidizing conditions in Oklo natural reactor zone 2, Gabon

    SciTech Connect

    Isobe, H.; Ohnuki, T.; Murakami, T.; Gauthier-Lafaye, F.

    1995-12-31

    This mineralogical study was completed to elucidate the relationships between uranium distribution and alteration products of the host rock of natural reactor zone clays just below the reactor core. Uraninite is preserved without any alteration in the reactor core. Uranium minerals are found to be present in the fractures in the reactor zone clays associated with iron-mineral veins, galena and Ti-bearing minerals. Uranium, for which the phases could not be identified, occurs in iron-mineral veins and the iron-mineral rim of pyrite grains in the reactor zone clays. Uranium is not associated with granular iron minerals occurring in the illite matrix of the reactor zone clays. The degree of crystallinity and uranium content of the three iron-bearing alteration products suggest that they formed under different conditions; the granular iron minerals, under alteration conditions where uranium was not mobilized while the iron-mineral veins and the iron-mineral rim of pyrite, under conditions in which uranium is mobilized after the formation of the granular iron minerals.

  14. Machining of uranium and uranium alloys

    SciTech Connect

    Morris, T.O.

    1981-12-14

    Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures.

  15. Uranium, natural

    Integrated Risk Information System (IRIS)

    Uranium , natural ; CASRN 7440 - 61 - 1 Human health assessment information on a chemical substance is included in the IRIS database only after a comprehensive review of toxicity data , as outlined in the IRIS assessment development process . Sections I ( Health Hazard Assessments for Noncarcinogeni

  16. URANIUM ALLOYS

    DOEpatents

    Seybolt, A.U.

    1958-04-15

    Uranium alloys containing from 0.1 to 10% by weight, but preferably at least 5%, of either zirconium, niobium, or molybdenum exhibit highly desirable nuclear and structural properties which may be improved by heating the alloy to about 900 d C for an extended period of time and then rapidly quenching it.

  17. Ore petrography of a sedimentary uranium deposit, Live Oak County, Texas

    SciTech Connect

    Bomber, B.J.; Ledger, E.B.; Tieh, T.T.

    1986-01-01

    Samples from the McLean 5 open-pit uranium mine, a small high-grade deposit located along a normal fault in the Miocene Oakville sandstone of Live Oak County, Texas, have been studied for uranium abundance, distribution, and nature of occurrence on the microscopic level. The host sandstone is composed of quartz, feldspars, and volcanic rock fragments, cemented by sparry calcite. Authigenic minerals include iron disulfide minerals (dominantly pyrite and some marcasite) and small amounts of clays, Ti oxides, and opal. High-grade ore (to 3% U) occurs along the fault, decreasing to less than 1,000 ppm within 10 m from the fault. The ore mineral is amorphous pitchblende and exhibits botryoidal morphology. The microscopic occurrence of uranium, documented by fission-track mapping of petrographic thin sections, is presented in detail. Uranium occurs abundantly as grain coatings and fillings in intergranular spaces in samples with high uranium content, where calcite cement has been partially or totally leached as mineralization proceeded. Lesser amounts are adsorbed onto leucoxene (microcrystalline anatase), mud clasts, and altered igneous rock fragments. Adsorbed uranium is the major code of occurrence in samples, with lower uranium contents farther from the orebody. Textural relations indicate that iron sulfides formed both before and after mineralization. Initial mineralization was by adsorption onto aggregates of fine particles of Ti oxide and clay minerals of various origins. With dissolution of cement and continued uranium influx, uranium precipitated as grain coatings and pore fillings.

  18. Minerals yearbook: Mineral industries of Africa. Volume 3. 1990 international review

    SciTech Connect

    Not Available

    1990-01-01

    The 53 countries that constituted Africa in 1990 accounted for a significant portion of total world output of a number of mineral commodities. Among the most significant to be produced in Africa were andalusite, antimony, asbestos, bauxite, chromite, coal, cobalt, copper, diamond, fluorspar, gold, lithium minerals, manganese, phosphate, platinum-group metals, the titanium minerals--ilmenite and rutile, vanadium, vermiculite, uranium, and zircon. Several of these, chromite, cobalt, diamond, and manganese, were not produced in the United States.

  19. Clay Mineral: Radiological Characterization

    NASA Astrophysics Data System (ADS)

    Cotomácio, J. G.; Silva, P. S. C.; Mazzilli, B. P.

    2008-08-01

    Since the early days, clays have been used for therapeutic purposes. Nowadays, most minerals applied as anti-inflammatory, pharmaceutics and cosmetic are the clay minerals that are used as the active ingredient or, as the excipient, in formulations. Although their large use, few information is available in literature on the content of the radionuclide concentrations of uranium and thorium natural series and 40K in these clay minerals. The objective of this work is to determine the concentrations of 238U, 232Th, 226Ra, 228Ra, 210Pb and 40K in commercial samples of clay minerals used for pharmaceutical or cosmetic purposes. Two kinds of clays samples were obtained in pharmacies, named green clay and white clay. Measurement for the determination of 238U and 232Th activity concentration was made by alpha spectrometry and gamma spectrometry was used for 226Ra, 228Ra, 210Pb and 40K determination. Some physical-chemical parameters were also determined as organic carbon and pH. The average activity concentration obtained was 906±340 Bq kg-1 for 40K, 40±9 Bq kg-1 for 226Ra, 75±9 Bq kg-1 for 228Ra, 197±38 Bq kg-1 for 210Pb, 51±26 Bq kg-1 for 238U and 55±24 Bq kg-1 for 232Th, considering both kinds of clay.

  20. Bioleaching of Minerals

    SciTech Connect

    F. Roberto

    2002-02-01

    Bioleaching is the term used to describe the microbial dissolution of metals from minerals. The commercial bioleaching of metals, particularly those hosted in sulfide minerals, is supported by the technical disciplines of biohydrometallurgy, hydrometallurgy, pyrometallurgy, chemistry, electrochemistry, and chemical engineering. The study of the natural weathering of these same minerals, above and below ground, is also linked to the fields of geomicrobiology and biogeochemistry. Studies of abandoned and disused mines indicate that the alterations of the natural environment due to man's activities leave as remnants microbiological activity that continues the biologically mediated release of metals from the host rock (acid rock drainage; ARD). A significant fraction of the world's copper, gold and uranium is now recovered by exploiting native or introduced microbial communities. While some members of these unique communities have been extensively studied for the past 50 years, our knowledge of the composition of these communities, and the function of the individual species present remains relatively limited. Nevertheless, bioleaching represents a major strategy in mineral resource recovery whose importance will increase as ore reserves decline in quality, become more difficult to process (due to increased depth, increased need for comminution, for example), and as environmental considerations eliminate traditional physical processes such as smelting, which have served the mining industry for hundreds of years.

  1. The Auchenorrhyncha fauna of peat bogs in the Austrian part of the Bohemian Forest (Insecta, Hemiptera).

    PubMed

    Holzinger, Werner E; Schlosser, Lydia

    2013-01-01

    The first overview on the Auchenorrhyncha fauna of peat bogs of the Austrian Bohemian Forest is presented. Seven oligotrophic peat bog sites were studied in 2011 by suction sampler ("G-Vac") and 93 Auchenorrhyncha species (with 7465 adult specimens) were recorded. Eleven species (about 18 % of the individuals) are tyrphobiontic or tyrphophilous. The relative species abundance plot is not very steep; the six most abundant species represent 50 % of the individuals. The most common species is Conomelus anceps (17 % of the individuals). Compared to the whole Austrian Auchenorrhyncha fauna, the fauna of peat bogs comprises distinctly more univoltine species and more species hibernating in nymphal stage. Densities of adult Auchenorrhyncha in peat bogs are low in spring (about 10-60 individuals per m²) and high in July, with up to 180 (±50) individuals per m². Disturbed peat bogs have higher species numbers and higher Auchenorrhyncha densities in total, but lower numbers and densities in peat bog specialists. PMID:24039517

  2. Adjusting stream-sediment geochemical maps in the Austrian Bohemian Massif by analysis of variance

    USGS Publications Warehouse

    Davis, J.C.; Hausberger, G.; Schermann, O.; Bohling, G.

    1995-01-01

    The Austrian portion of the Bohemian Massif is a Precambrian terrane composed mostly of highly metamorphosed rocks intruded by a series of granitoids that are petrographically similar. Rocks are exposed poorly and the subtle variations in rock type are difficult to map in the field. A detailed geochemical survey of stream sediments in this region has been conducted and included as part of the Geochemischer Atlas der Republik O??sterreich, and the variations in stream sediment composition may help refine the geological interpretation. In an earlier study, multivariate analysis of variance (MANOVA) was applied to the stream-sediment data in order to minimize unwanted sampling variation and emphasize relationships between stream sediments and rock types in sample catchment areas. The estimated coefficients were used successfully to correct for the sampling effects throughout most of the region, but also introduced an overcorrection in some areas that seems to result from consistent but subtle differences in composition of specific rock types. By expanding the model to include an additional factor reflecting the presence of a major tectonic unit, the Rohrbach block, the overcorrection is removed. This iterative process simultaneously refines both the geochemical map by removing extraneous variation and the geological map by suggesting a more detailed classification of rock types. ?? 1995 International Association for Mathematical Geology.

  3. On the occurrence of Ctenocheles (Decapoda, Axiidea, Ctenochelidae) in the Bohemian Cretaceous Basin

    PubMed Central

    HYŽNÝ, MATÚŠ; VESELSKÁ, MARTINA KOČOVÁ; DVOŘÁK, PAVEL

    2015-01-01

    Because of close morphological affinities, fossil cheliped fragments of the ghost shrimp Ctenocheles (Decapoda, Axiidea, Ctenochelidae) can be easily misidentified as remains of different decapod crustacean taxa. Re-examination of the Cretaceous decapods deposited in the National Museum in Prague revealed that all supposed specimens of the lobster genus Oncopareia found in the Middle Coniacian calcareous claystones of the Březno Formation, including one of the Fritsch’s original specimens of Stenocheles parvulus, actually belong to Ctenocheles. This material together with newly collected specimens from the same locality, allowed for erection of a new species, Ctenocheles fritschi. Its major chela possesses a serrated ischium and ovoid, unarmed merus; therefore, it is considered a close relative of the extant C. collini and C. maorianus. Ctenocheles fritschi sp. nov. represents the first report on the occurrence of the genus from the Bohemian Cretaceous Basin. It is one of the oldest records of Ctenocheles and simultaneously one of the best preserved fossils of the genus reported to date. Confusing taxonomy of S. parvulus is reviewed and shortly discussed. PMID:25983568

  4. Uranium industry annual 1996

    SciTech Connect

    1997-04-01

    The Uranium Industry Annual 1996 (UIA 1996) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. The UIA 1996 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. Data on uranium raw materials activities for 1987 through 1996 including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2006, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, uranium imports and exports, and uranium inventories are shown in Chapter 2. A feature article, The Role of Thorium in Nuclear Energy, is included. 24 figs., 56 tabs.

  5. Quarterly minerals outlook, June 1983

    SciTech Connect

    Glass, G.B.

    1983-01-01

    An overview is presented of the mineral industry of Wyoming. Petroleum production shows a slight annual decline. Many producers have been shutting in their natural gas wells due to the sharp decline in demand. Activities in the base, precious, and ferrous metals industry are summarized. Uranium and trona production is down from the previous year. Other minerals mentioned are gypsum, limestone, bentonite, and phosphorus. Production of coal is given by county. Electric utilities have not used all the coal they bought last year, and construction of several power plants have been delayed indefinitely. Underground coal gasification projects are mentioned. Tables present production forecasts for coal to 1990, for oil and gas to 1988, and for uranium and trona to 1987. 5 tables.

  6. Bioremediation of uranium contaminated soils and wastes

    SciTech Connect

    Francis, A.J.

    1998-12-31

    Contamination of soils, water, and sediments by radionuclides and toxic metals from uranium mill tailings, nuclear fuel manufacturing and nuclear weapons production is a major concern. Studies of the mechanisms of biotransformation of uranium and toxic metals under various microbial process conditions has resulted in the development of two treatment processes: (1) stabilization of uranium and toxic metals with reduction in waste volume and (2) removal and recovery of uranium and toxic metals from wastes and contaminated soils. Stabilization of uranium and toxic metals in wastes is accomplished by exploiting the unique metabolic capabilities of the anaerobic bacterium, Clostridium sp. The radionuclides and toxic metals are solubilized by the bacteria directly by enzymatic reductive dissolution, or indirectly due to the production of organic acid metabolites. The radionuclides and toxic metals released into solution are immobilized by enzymatic reductive precipitation, biosorption and redistribution with stable mineral phases in the waste. Non-hazardous bulk components of the waste volume. In the second process uranium and toxic metals are removed from wastes or contaminated soils by extracting with the complexing agent citric acid. The citric-acid extract is subjected to biodegradation to recover the toxic metals, followed by photochemical degradation of the uranium citrate complex which is recalcitrant to biodegradation. The toxic metals and uranium are recovered in separate fractions for recycling or for disposal. The use of combined chemical and microbiological treatment process is more efficient than present methods and should result in considerable savings in clean-up and disposal costs.

  7. National Uranium Resource Evaluation, Klamath Falls Quadrangle, Oregon and California

    SciTech Connect

    Castor, S.B.; Berry, M.R.; Robins, J.W.

    1982-07-01

    The Klamath Falls Quadrangle, Oregon, was evaluated to identify and delineate areas favorable for uranium deposits according to criteria developed for the National Uranium Resource Evaluation. Surface radiometric reconnaissance and geochemical sampling were used for overall evaluation of the quadrangle. Detailed rock sampling, geologic mapping, and examinations of uranium mines and occurrences were performed in suspected favorable areas. Results of the work indicate good potential for shallow hydrothermal volcanogenic uranium deposits in the Lakeview favorable area, which comprises a northwest-trending belt of rhyolite intrusions in the eastern half of the quadrangle. The young age, peraluminous chemistry, and low thorium-to-uranium ratios of the rhyolite intrusions, as well as low uranium content of groundwater samples, indicate that uranium has not been leached from the intrusions by ground water. Therefore, supergene uranium deposits are not likely in the area. Scattered occurrences of ash-flow tuff in the east half of the quadrangle that contain high uranium and (or) thorium contents, and four occurrences of secondary uranium minerals in ash-flow tuff, indicate possible uranium deposits in ash flows in a poorly defined area that is partially coextensive with the Lakeview favorable area. Small granitic plutons with associated quartz-tourmaline breccia veins and base-metal occurrences may also be favorable for uranium deposits but were not examined during this study.

  8. Hydrothermal Phase Relations Among Uranyl Minerals at the Nopal I Analog Site

    SciTech Connect

    Murphy, William M.

    2007-07-01

    Uranyl mineral paragenesis at Nopal I is an analog of spent fuel alteration at Yucca Mountain. Petrographic studies suggest a variety of possible hydrothermal conditions for uranium mineralization at Nopal I. Calculated equilibrium phase relations among uranyl minerals show uranophane stability over a broad range of realistic conditions and indicate that uranyl mineral variety reflects persistent chemical potential heterogeneity. (author)

  9. Search for uranium in western United States

    USGS Publications Warehouse

    McKelvey, Vincent Ellis

    1953-01-01

    The search for uranium in the United States is one of the most intensive ever made for any metal during our history. The number of prospectors and miners involved is difficult to estimate but some measure of the size of the effort is indicated by the fact that about 500 geologists are employed by government and industry in the work--more than the total number of geologists engaged in the study of all other minerals together except oil. The largest part of the effort has been concentrated in the western states. No single deposit of major importance by world standards has been discovered but the search has led to the discovery of important minable deposits of carnotite and related minerals on the Colorado Plateau; of large, low grade deposits of uranium in phosphates in the northwestern states and in lignites in the Dakotas, Wyoming, Idaho and New Mexico; and of many new and some promising occurrences of uranium in carnotite-like deposits and in vein deposits. Despite the fact that a large number of the districts considered favorable for the occurrence of uranium have already been examined, the outlook for future discoveries is bright, particularly for uranium in vein and in carnotite-like deposits in the Rocky Mountain States.

  10. The History of Uranium Mining and the Navajo People

    PubMed Central

    Brugge, Doug; Goble, Rob

    2002-01-01

    From World War II until 1971, the government was the sole purchaser of uranium ore in the United States. Uranium mining occurred mostly in the southwestern United States and drew many Native Americans and others into work in the mines and mills. Despite a long and well-developed understanding, based on the European experience earlier in the century, that uranium mining led to high rates of lung cancer, few protections were provided for US miners before 1962 and their adoption after that time was slow and incomplete. The resulting high rates of illness among miners led in 1990 to passage of the Radiation Exposure Compensation Act. PMID:12197966

  11. Derived enriched uranium market

    SciTech Connect

    Rutkowski, E.

    1996-12-01

    The potential impact on the uranium market of highly enriched uranium from nuclear weapons dismantling in the Russian Federation and the USA is analyzed. Uranium supply, conversion, and enrichment factors are outlined for each country; inventories are also listed. The enrichment component and conversion components are expected to cause little disruption to uranium markets. The uranium component of Russian derived enriched uranium hexafluoride is unresolved; US legislation places constraints on its introduction into the US market.

  12. Uranium on the Checkerboard: Crisis at Crownpoint

    ERIC Educational Resources Information Center

    Barry, Tom; Wood, Beth

    1978-01-01

    Some 22 companies are currently exploring for uranium in the Crownpoint, New Mexico area. Due to complicated patterns of land and mineral ownership on the Navajo Reservation, the mining companies do not feel obligated to communicate, and the Navajo are, consequently, worried about their social and physical environment. (JC)

  13. Cleaning of uranium vs machine coolant formulations

    SciTech Connect

    Cristy, S.S.; Byrd, V.R.; Simandl, R.F.

    1984-10-01

    This study compares methods for cleaning uranium chips and the residues left on chips from alternate machine coolants based on propylene glycol-water mixtures with either borax, ammonium tetraborate, or triethanolamine tetraborate added as a nuclear poison. Residues left on uranium surfaces machined with perchloroethylene-mineral oil coolant and on surfaces machined with the borax-containing alternate coolant were also compared. In comparing machined surfaces, greater chlorine contamination was found on the surface of the perchloroethylene-mineral oil machined surfaces, but slightly greater oxidation was found on the surfaces machined with the alternate borax-containing coolant. Overall, the differences were small and a change to the alternate coolant does not appear to constitute a significant threat to the integrity of machined uranium parts.

  14. Industrial Minerals.

    ERIC Educational Resources Information Center

    Brady, Lawrence L.

    1983-01-01

    Discusses trends in and factors related to the production of industrial minerals during 1982, indicating that, as 1981 marked a downturn in production of industrial minerals, 1982 continued the trend with temporary and permanent cutbacks in mine and plant production. Includes highlights of several conferences/conference papers in this field.…

  15. Uranium in granites from the southwestern United States: actinide parent-daughter systems, sites and mobilization. Second year report. National Uranium Resource Evaluation

    SciTech Connect

    Silver, L.T.; Woodhead, J.A.; Williams, I.S.; Chappell, B.W.

    1984-09-01

    Results of detailed field and laboratory studies are reported on the primary distribution of uranium (and thorium and lead) in the radioactive minerals of five radioactive granite bodies in Arizona and California. This distribution was examined in a granite pluton. Granites with uranium concentrations ranging from 4 to 47 ppM, thorium concentrations from 11 to 181 ppM, and Th/U ratios of 0.6 to 16.0 were compared. Evidence for secondary mobilization, migration, fixation and/or loss of uranium, thorium and radiogenic leads was explored. Uranium distribution in radioactive granites is hosted in a far greater diversity of sites than has previously been known. Uranium and thorium distribution in primary minerals of granites is almost entirely a disequilibrium product involving local fractionation processes during magmatic crystallization. Every radioactive granite studied contains minerals that contain uranium and/or thorium as major stoichiometric components. When the granites are subject to secondary geochemical events and processes, the behavior of uranium is determined by the stability fields of the different radioactive minerals in the rocks. The two most powerful tools for evaluating uranium migration in a granite are (a) isotope dilution mass spectrometry and (b) the electron microprobe. Uranium mobilization and loss is a common feature in radioactive granites of the southwestern United States. A model for the evaluation of uranium loss from granites has been developed. The mineral zircon can be used as an independent indicator of uranium and thorium endowment. The weathering products show surprising differences in the response of different granites in arid region settings. Significant losses of primary uranium (up to 70%) has been a common occurrence. Uranium, thorium and radiogenic lead exist in labile (movable) form on surfaces of cleavages, fractures and grain boundaries in granites.

  16. The Nopal 1 Uranium Deposit: an Overview

    NASA Astrophysics Data System (ADS)

    Calas, G.; Allard, T.; Galoisy, L.

    2007-05-01

    The Nopal 1 natural analogue is located in the Pena Blanca uranium district, about 50 kms north of Chihuahua City, Mexico. The deposit is hosted in tertiary ignimbritic ash-flow tuffs, dated at 44 Ma (Nopal and Colorados formations), and overlying the Pozos conglomerate formation and a sequence of Cretaceous carbonate rocks. The deposit is exposed at the ground surface and consists of a near vertical zone extending over about 100 m with a diameter of 40 m. An interesting characteristic is that the primary mineralization has been exposed above the water table, as a result of the uplift of the Sierra Pena Blanca, and subsequently oxidized with a remobilization of hexavalent uranium. The primary mineralization has been explained by various genetic models. It is associated to an extensive hydrothermal alteration of the volcanic tuffs, locally associated to pyrite and preserved by an intense silicification. Several kaolinite parageneses occur in fissure fillings and feldspar pseudomorphs, within the mineralized breccia pipe and the barren surrounding rhyolitic tuffs. Smectites are mainly developed in the underlying weakly welded tuffs. Several radiation-induced defect centers have been found in these kaolinites providing a unique picture of the dynamics of uranium mobilization (see Allard et al., this session). Another evidence of this mobilization is given by the spectroscopy of uranium-bearing opals, which show characteristic fluorescence spectra of uranyl groups sorbed at the surface of silica. By comparison with the other uranium deposits of the Sierra Pena Blanca and the nearby Sierra de Gomez, the Nopal 1 deposit is original, as it is one of the few deposits hving retained a reduced uranium mineralization.

  17. Flash flood in 1714 in the Bohemian-Moravian Highlands - Reconstructing a Catastrophe.

    NASA Astrophysics Data System (ADS)

    Elleder, Libor; Krejčí, Jakub; Šírová, Jolana

    2015-04-01

    Read against the backdrop of the past twenty years with their exceptional frequency of summer floods, records of historical flood events have become highly topical. Aside from the May flood of 1872, the flash flood that occurred at the turn of July and August 1714 in the Bohemian-Moravian Highlands is probably the most important case of its kind in the Czech lands, and may likely be ranked among the most notable occurrences of extreme weather even within the larger Central European context. Within the catchment basin of the Sázava River, the headwater level rose about three meters above the highest floods on the hydrological record and 1.5m above the highest historical flood-mark. Taking into account the time period - i.e., the beginning of the 18th century - some of the concurrent accounts of the flood are uncommonly detailed, containing not only a specification of the damage caused, but also high water mark figures and, at least in broad strokes, a record of the changing water levels over time. The flood caused tremendous material damage at the time, breaching e.g. about 70 fish ponds and destroying essentially all bridges; over 230 people were killed. It was revealed that the area of Žďárské vrchy (Žďár Hills) at the divide of the rivers Loučná, Chrudimka, Sázava, and Svratka which was impacted by the causative extreme precipitation may have measured 800 to 1000 square kilometers. Rough estimates of the headwater flow rate equal about four times current Q100 values. We therefore used the hydrological model Aqualog in order to determine whether an event of this scope was at all realistic. The goal was to assess whether it was realistically possible that precipitation may have been of such scope as to trigger a hydrological response of this intensity.

  18. The rare earth element potential of kaolin deposits in the Bohemian Massif (Czech Republic, Austria)

    NASA Astrophysics Data System (ADS)

    Höhn, S.; Frimmel, H. E.; Pašava, J.

    2014-12-01

    Four kaolin deposits in the Bohemian Massif were studied in order to assess the potential for the recovery of rare earth elements (REE) as by-products from the residue after extraction and refining of the raw kaolin. The behaviour of REE + Y during kaolinitization was found to be largely a function of pre-alteration mineralogy. In the examples studied, i.e. granite-derived deposits of Kriechbaum (Austria) and Božičany, and arkose-derived deposits of Kaznějov and Podbořany (all Czech Republic), the REE + Y are predominantly hosted by monazite which has remained unaffected by kaolinitization. The overall REE + Y content of the variably kaolinitized rocks is strongly dependent on their genesis. While ion adsorption plays only a minor role in the concentration of REE + Y in the studied kaolinitized rocks, the processing and refining of the raw kaolin leads to residues that are enriched in REE + Y by a factor of up to 40. The use of a magnetic separator and a hydrocyclone in the processing of the raw material can yield REE + Y contents of as much as 0.77 wt%. Although this value compares well with the REE + Y concentration in some potentially economic REE + Y projects elsewhere, the overall tonnage of the (REE + Y)-enriched residue is by far not sufficient to consider economic extraction of REE + Y as by-product. Our results are most probably applicable also to other kaolin deposits derived from the weathering of Hercynian basement granites elsewhere (e.g. in Saxonia and Bavaria, Germany). Overall, the potential for REE + Y production as by-product from kaolin mining has to be regarded as minimal.

  19. Influence of acidic and alkaline waste solution properties on uranium migration in subsurface sediments.

    PubMed

    Szecsody, Jim E; Truex, Mike J; Qafoku, Nikolla P; Wellman, Dawn M; Resch, Tom; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments have significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100 s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH2) resulted in a rapid (<10 h) increase in aqueous carbonate (with Ca(2+), Mg(2+)) and phosphate and a slow (100 s of hours) increase in silica, Al(3+), and K(+), likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH13) resulted in a rapid (<10h) increase in carbonate, followed by a slow (10 s to 100 s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in not only uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity. PMID:23851265

  20. Influence of acidic and alkaline waste solution properties on uranium migration in subsurface sediments

    NASA Astrophysics Data System (ADS)

    Szecsody, Jim E.; Truex, Mike J.; Qafoku, Nikolla P.; Wellman, Dawn M.; Resch, Tom; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments have significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100 s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH 2) resulted in a rapid (< 10 h) increase in aqueous carbonate (with Ca2 +, Mg2 +) and phosphate and a slow (100 s of hours) increase in silica, Al3 +, and K+, likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH 13) resulted in a rapid (< 10 h) increase in carbonate, followed by a slow (10 s to 100 s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in not only uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity.

  1. Influence of Acidic and Alkaline Waste Solution Properties on Uranium Migration in Subsurface Sediments

    SciTech Connect

    Szecsody, James E.; Truex, Michael J.; Qafoku, Nikolla; Wellman, Dawn M.; Resch, Charles T.; Zhong, Lirong

    2013-08-01

    This study shows that acidic and alkaline wastes co-disposed with uranium into subsurface sediments has significant impact on changes in uranium retardation, concentration, and mass during downward migration. For uranium co-disposal with acidic wastes, significant rapid (i.e., hours) carbonate and slow (i.e., 100s of hours) clay dissolution resulted, releasing significant sediment-associated uranium, but the extent of uranium release and mobility change was controlled by the acid mass added relative to the sediment proton adsorption capacity. Mineral dissolution in acidic solutions (pH 2) resulted in a rapid (< 10 h) increase in aqueous carbonate (with Ca2+, Mg2+) and phosphate and a slow (100s of hours) increase in silica, Al3+, and K+, likely from 2:1 clay dissolution. Infiltration of uranium with a strong acid resulted in significant shallow uranium mineral dissolution and deeper uranium precipitation (likely as phosphates and carbonates) with downward uranium migration of three times greater mass at a faster velocity relative to uranium infiltration in pH neutral groundwater. In contrast, mineral dissolution in an alkaline environment (pH 13) resulted in a rapid (< 10 h) increase in carbonate, followed by a slow (10s to 100s of hours) increase in silica concentration, likely from montmorillonite, muscovite, and kaolinite dissolution. Infiltration of uranium with a strong base resulted in uranium-silicate precipitation (presumed Na-boltwoodite) but also desorption of natural uranium on the sediment due to the high ionic strength solution, or 60% greater mass with greater retardation compared with groundwater. Overall, these results show that acidic or alkaline co-contaminant disposal with uranium can result in complex depth- and time-dependent changes in uranium dissolution/precipitation reactions and uranium sorption, which alter the uranium migration mass, concentration, and velocity.

  2. Enhanced Uranium Immobilization and Reduction by Geobacter sulfurreducens Biofilms

    PubMed Central

    Cologgi, Dena L.; Speers, Allison M.; Bullard, Blair A.; Kelly, Shelly D.

    2014-01-01

    Biofilms formed by dissimilatory metal reducers are of interest to develop permeable biobarriers for the immobilization of soluble contaminants such as uranium. Here we show that biofilms of the model uranium-reducing bacterium Geobacter sulfurreducens immobilized substantially more U(VI) than planktonic cells and did so for longer periods of time, reductively precipitating it to a mononuclear U(IV) phase involving carbon ligands. The biofilms also tolerated high and otherwise toxic concentrations (up to 5 mM) of uranium, consistent with a respiratory strategy that also protected the cells from uranium toxicity. The enhanced ability of the biofilms to immobilize uranium correlated only partially with the biofilm biomass and thickness and depended greatly on the area of the biofilm exposed to the soluble contaminant. In contrast, uranium reduction depended on the expression of Geobacter conductive pili and, to a lesser extent, on the presence of the c cytochrome OmcZ in the biofilm matrix. The results support a model in which the electroactive biofilm matrix immobilizes and reduces the uranium in the top stratum. This mechanism prevents the permeation and mineralization of uranium in the cell envelope, thereby preserving essential cellular functions and enhancing the catalytic capacity of Geobacter cells to reduce uranium. Hence, the biofilms provide cells with a physically and chemically protected environment for the sustained immobilization and reduction of uranium that is of interest for the development of improved strategies for the in situ bioremediation of environments impacted by uranium contamination. PMID:25128347

  3. Uranium Industry Annual, 1992

    SciTech Connect

    Not Available

    1993-10-28

    The Uranium Industry Annual provides current statistical data on the US uranium industry for the Congress, Federal and State agencies, the uranium and electric utility industries, and the public. The feature article, ``Decommissioning of US Conventional Uranium Production Centers,`` is included. Data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2.

  4. Chemical Equilibrium of the Dissolved Uranium in Groundwaters From a Spanish Uranium-Ore Deposit

    SciTech Connect

    Garralon, Antonio; Gomez, Paloma; Turrero, Maria Jesus; Buil, Belen; Sanchez, Lorenzo

    2007-07-01

    The main objectives of this work are to determine the hydrogeochemical evolution of an uranium ore and identify the main water/rock interaction processes that control the dissolved uranium content. The Mina Fe uranium-ore deposit is the most important and biggest mine worked in Spain. Sageras area is located at the north part of the Mina Fe, over the same ore deposit. The uranium deposit was not mined in Sageras and was only perturbed by the exploration activities performed 20 years ago. The studied area is located 10 Km northeast of Ciudad Rodrigo (Salamanca) at an altitude over 650 m.a.s.l. The uranium mineralization is related to faults affecting the metasediments of the Upper Proterozoic to Lower Cambrian schist-graywacke complex (CEG), located in the Centro-Iberian Zone of the Hesperian Massif . The primary uranium minerals are uraninite and coffinite but numerous secondary uranium minerals have been formed as a result of the weathering processes: yellow gummite, autunite, meta-autunite, torbernite, saleeite, uranotile, ianthinite and uranopilite. The water flow at regional scale is controlled by the topography. Recharge takes place mainly in the surrounding mountains (Sierra Pena de Francia) and discharge at fluvial courses, mainly Agueda and Yeltes rivers, boundaries S-NW and NE of the area, respectively. Deep flows (lower than 100 m depth) should be upwards due to the river vicinity, with flow directions towards the W, NW or N. In Sageras-Mina Fe there are more than 100 boreholes drilled to investigate the mineral resources of the deposit. 35 boreholes were selected in order to analyze the chemical composition of groundwaters based on their depth and situation around the uranium ore. Groundwater samples come from 50 to 150 m depth. The waters are classified as calcium-bicarbonate type waters, with a redox potential that indicates they are slightly reduced (values vary between 50 to -350 mV). The TOC varies between <0.1 and 4.0 mgC/L and the dissolved

  5. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2011 CFR

    2011-07-01

    ... 31 Money and Finance:Treasury 3 2011-07-01 2011-07-01 false Uranium feed; natural uranium feed...) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed. The term uranium feed or natural uranium feed means natural uranium in the form of UF6 suitable for...

  6. 31 CFR 540.317 - Uranium feed; natural uranium feed.

    Code of Federal Regulations, 2010 CFR

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed...) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed. The term uranium feed or natural uranium feed means natural uranium in the form of UF6 suitable for...

  7. URANIUM EXTRACTION

    DOEpatents

    Harrington, C.D.; Opie, J.V.

    1958-07-01

    The recovery of uranium values from uranium ore such as pitchblende is described. The ore is first dissolved in nitric acid, and a water soluble nitrate is added as a salting out agent. The resulting feed solution is then contacted with diethyl ether, whereby the bulk of the uranyl nitrate and a portion of the impurities are taken up by the ether. This acid ether extract is then separated from the aqueous raffinate, and contacted with water causing back extractioa of the uranyl nitrate and impurities into the water to form a crude liquor. After separation from the ether extract, this crude liquor is heated to about 118 deg C to obtain molten uranyl nitrate hexahydratc. After being slightly cooled the uranyl nitrate hexahydrate is contacted with acid free diethyl ether whereby the bulk of the uranyl nitrate is dissolved into the ethcr to form a neutral ether solution while most of the impurities remain in the aqueous waste. After separation from the aqueous waste, the resultant ether solution is washed with about l0% of its volume of water to free it of any dissolved impurities and is then contacted with at least one half its volume of water whereby the uranyl nitrate is extracted into the water to form an aqueous product solution.

  8. Treatability Test Plan for 300 Area Uranium Stabilization through Polyphosphate Injection

    SciTech Connect

    Vermeul, Vincent R.; Williams, Mark D.; Fritz, Brad G.; Mackley, Rob D.; Mendoza, Donaldo P.; Newcomer, Darrell R.; Rockhold, Mark L.; Williams, Bruce A.; Wellman, Dawn M.

    2007-06-01

    The U.S. Department of Energy has initiated a study into possible options for stabilizing uranium at the 300 Area using polyphosphate injection. As part of this effort, PNNL will perform bench- and field-scale treatability testing designed to evaluate the efficacy of using polyphosphate injections to reduced uranium concentrations in the groundwater to meet drinking water standards (30 ug/L) in situ. This technology works by forming phosphate minerals (autunite and apatite) in the aquifer that directly sequester the existing aqueous uranium in autunite minerals and precipitates apatite minerals for sorption and long term treatment of uranium migrating into the treatment zone, thus reducing current and future aqueous uranium concentrations. Polyphosphate injection was selected for testing based on technology screening as part of the 300-FF-5 Phase III Feasibility Study for treatment of uranium in the 300-Area.

  9. High resolution remote sensing image processing technology and its application to uranium geology

    NASA Astrophysics Data System (ADS)

    Zhang, Jie-lin

    2008-12-01

    Hyperspectral and high spatial resolution remote sensing technology take important role in uranium geological application, data mining and knowledge discovery methods are key to character spectral and spatial information of uranium mineralization factors. Based on curvelet transform algorithm, this paper developed the image fusion technology of hyperspectral (Hyperion) and high spatial data (SPOT5), and results demonstrated that fusion image had advantage in denoising, enhancing and information identification. Used discrete wavelet transform, the spectral parameters of uranium mineralization factors were acquired, the spectral identification pedigrees of typical quadrivalence and hexavalence uranium minerals were established. Furthermore, utilizing hyperspectral remote sensing observation technology, this paper developed hyperspectral logging of drill cores and trench, it can quickly processed lots of geological and spectral information, and the relationship between radioactive intensity and abnormal spectral characteristics of Fe3+ was established. All those provided remote sensing technical bases to uranium geology, and the better results have been achieved in Taoshan uranium deposits in south China.

  10. Mineral Quantification.

    PubMed

    2016-01-01

    Optimal intakes of elements, such as sodium, potassium, magnesium, calcium, manganese, copper, zinc and iodine, can reduce individual risk factors including those related to cardiovascular diseases among humans and animals. In order to meet the need for vitamins, major minerals, trace minerals, fatty acids and amino acids, it is necessary to include a full spectrum programme that can deliver all of the nutrients in the right ratio. Minerals are required for normal growth, activities of muscles, skeletal development (such as calcium), cellular activity, oxygen transport (copper and iron), chemical reactions in the body, intestinal absorption (magnesium), fluid balance and nerve transmission (sodium and potassium), as well as the regulation of the acid base balance (phosphorus). The chapter discusses the chemical and instrumentation techniques used for estimation of minerals such as N, P, Ca, Mg, K, Na, Fe, Cu, Zn, B and Mb. PMID:26939263