Incidence of Leukemia, Lymphoma, and Multiple Myeloma in Czech Uranium Miners: A Case–Cohort Study

PubMed Central

Řeřicha, Vladimír; Kulich, Michal; Řeřicha, Robert; Shore, David L.; Sandler, Dale P.

2006-01-01

Objective Uranium miners are chronically exposed to low levels of radon and its progeny. We investigated whether radon exposure is associated with increased incidence of leukemia, lymphoma, or multiple myeloma in this population. Design We conducted a retrospective case–cohort study in 23,043 uranium miners and identified a total of 177 incident cases of leukemia, lymphoma, and myeloma. Detailed information on occupational radon exposure was obtained for the cases and a randomly selected subcohort of 2,393 subjects. We used the proportional hazards model with power relative risk (RR) function to estimate and test the effects of cumulative radon exposures on incidence rates. Results Incidence of all leukemia combined and chronic lymphocytic leukemia (CLL) alone was positively associated with cumulative radon exposure. The RR comparing high radon exposure [110 working level months (WLM); 80th percentile] to low radon exposure (3 WLM; 20th percentile) was 1.75 [95% confidence interval (CI), 1.10–2.78; p = 0.014] for all leukemia combined and 1.98 (95% CI, 1.10–3.59; p = 0.016) for CLL. Myeloid leukemia and Hodgkin lymphoma were also associated with radon, but RRs were not statistically significant. There was no apparent association of radon with either non-Hodgkin lymphoma or multiple myeloma. Exposure to radon and its progeny was associated with an increased risk of developing leukemia in underground uranium miners. CLL, not previously believed to be radiogenic, was linked to radon exposure. PMID:16759978

Reactivity of Uranium and Ferrous Iron with Natural Iron Oxyhydroxides.

PubMed

Stewart, Brandy D; Cismasu, A Cristina; Williams, Kenneth H; Peyton, Brent M; Nico, Peter S

2015-09-01

Determining key reaction pathways involving uranium and iron oxyhydroxides under oxic and anoxic conditions is essential for understanding uranium mobility as well as other iron oxyhydroxide mediated processes, particularly near redox boundaries where redox conditions change rapidly in time and space. Here we examine the reactivity of a ferrihydrite-rich sediment from a surface seep adjacent to a redox boundary at the Rifle, Colorado field site. Iron(II)-sediment incubation experiments indicate that the natural ferrihydrite fraction of the sediment is not susceptible to reductive transformation under conditions that trigger significant mineralogical transformations of synthetic ferrihydrite. No measurable Fe(II)-promoted transformation was observed when the Rifle sediment was exposed to 30 mM Fe(II) for up to 2 weeks. Incubation of the Rifle sediment with 3 mM Fe(II) and 0.2 mM U(VI) for 15 days shows no measurable incorporation of U(VI) into the mineral structure or reduction of U(VI) to U(IV). Results indicate a significantly decreased reactivity of naturally occurring Fe oxyhydroxides as compared to synthetic minerals, likely due to the association of impurities (e.g., Si, organic matter), with implications for the mobility and bioavailability of uranium and other associated species in field environments.

Release behavior of uranium in uranium mill tailings under environmental conditions.

PubMed

Liu, Bo; Peng, Tongjiang; Sun, Hongjuan; Yue, Huanjuan

2017-05-01

Uranium contamination is observed in sedimentary geochemical environments, but the geochemical and mineralogical processes that control uranium release from sediment are not fully appreciated. Identification of how sediments and water influence the release and migration of uranium is critical to improve the prevention of uranium contamination in soil and groundwater. To understand the process of uranium release and migration from uranium mill tailings under water chemistry conditions, uranium mill tailing samples from northwest China were investigated with batch leaching experiments. Results showed that water played an important role in uranium release from the tailing minerals. The uranium release was clearly influenced by contact time, liquid-solid ratio, particle size, and pH under water chemistry conditions. Longer contact time, higher liquid content, and extreme pH were all not conducive to the stabilization of uranium and accelerated the uranium release from the tailing mineral to the solution. The values of pH were found to significantly influence the extent and mechanisms of uranium release from minerals to water. Uranium release was monitored by a number of interactive processes, including dissolution of uranium-bearing minerals, uranium desorption from mineral surfaces, and formation of aqueous uranium complexes. Considering the impact of contact time, liquid-solid ratio, particle size, and pH on uranium release from uranium mill tailings, reducing the water content, decreasing the porosity of tailing dumps and controlling the pH of tailings were the key factors for prevention and management of environmental pollution in areas near uranium mines. Copyright © 2017 Elsevier Ltd. All rights reserved.

Sandstone type uranium deposits in the Ordos Basin, Northwest China: A case study and an overview

NASA Astrophysics Data System (ADS)

Akhtar, Shamim; Yang, Xiaoyong; Pirajno, Franco

2017-09-01

This paper provides a comprehensive review on studies of sandstone type uranium deposits in the Ordos Basin, Northwest China. As the second largest sedimentary basin, the Ordos Basin has great potential for targeting sandstone type U mineralization. The newly found and explored Dongsheng and Diantou sandstone type uranium deposits are hosted in the Middle Jurassic Zhilou Formation. A large number of investigations have been conducted to trace the source rock compositions and relationship between lithic subarkose sandstone host rock and uranium mineralization. An optical microscopy study reveals two types of alteration associated with the U mineralization: chloritization and sericitization. Some unusual mineral structures, with compositional similarity to coffinite, have been identified in a secondary pyrite by SEM These mineral phases are proposed to be of bacterial origin, following high resolution mapping of uranium minerals and trace element determinations in situ. Moreover, geochemical studies of REE and trace elements constrained the mechanism of uranium enrichment, displaying LREE enrichment relative to HREE. Trace elements such as Pb, Mo and Ba have a direct relationship with uranium enrichment and can be used as index for mineralization. The source of uranium ore forming fluids and related geological processes have been studied using H, O and C isotope systematics of fluid inclusions in quartz veins and the calcite cement of sandstone rocks hosting U mineralization. Both H and O isotopic compositions of fluid inclusions reveal that ore forming fluids are a mixture of meteoric water and magmatic water. The C and S isotopes of the cementing material of sandstone suggest organic origin and bacterial sulfate reduction (BSR), providing an important clue for U mineralization. Discussion of the ore genesis shows that the greenish gray sandstone plays a crucial role during processes leading to uranium mineralization. Consequently, an oxidation-reduction model for sandstone-type uranium deposit is proposed, which can elucidate the source of uranium in the deposits of the Ordos Basin, based on the role of organic materials and sulfate reducing bacteria. We discuss the mechanism of uranium deposition responsible for the genesis of these large sandstone type uranium deposits in this unique sedimentary basin.

Radioactive deposits in California

USGS Publications Warehouse

Walker, George W.; Lovering, Tom G.

1954-01-01

Reconnaissance examination by Government geologists of many areas, mine properties, and prospects in California during the period between 1948 and 1953 has confirmed the presence of radioactive materials in place at more than 40 localities. Abnormal radioactivity at these localities is due to concentrations of primary and secondary uranium minerals, to radon gas, radium (?), and to thorium minerals. Of the known occurrences only three were thought to contain uranium oxide (uranitite or pitchblende), 4 contained uranium-bearing columbate, tantalate, or titanate minerals, 12 contained secondary uranium minerals, such as autunite, carnotite, and torbernite, one contained radon gas, 7 contained thorium minerals, and, at the remaining 16 localities, the source of the anomalous radiation was not positively determined. The occurrences in which uranium oxide has been tentatively identified include the Rathgeb mine (Calaveras County), the Yerih group of claims (San Bernardino County), and the Rainbow claim (Madera County). Occurrences of secondary uranium minerals are largely confined to the arid desert regions of south-eastern California including deposits in San Bernardino, Kern, Inyo, and Imperial Counties. Uranium-bearing columbate, tantalate, or titanate minerals have been reported from pegmatite and granitic rock in southeastern and eastern California. Thorium minerals have been found in vein deposits in eastern San Bernardino County and from pegmatites and granitic rocks in various parts of southeastern California; placer concentrations of thorium minerals are known from nearly all areas in the State that are underlain, in part, by plutonic crystalline rocks. The primary uranium minerals occur principally as minute accessory crystals in pegmatite or granitic rock, or with base-metal sulfide minerals in veins. Thorium minerals also occur as accessory crystals in pegmatite or granitic rock, in placer deposits derived from such rock, and, at Mountain Pass, in veins containing rare earths. Secondary uranium minerals have been found as fracture coatings and as disseminations in various types of wall rock, although they are largely confined to areas of Tertiary volcanic rocks. Probably the uranium in the uraniferous deposits in California is related genetically to felsic crystalline rocks and felsic volcanic rocks; the present distribution of the secondary uranium minerals has been controlled, in part, by circulating ground waters and probably, in part, by magmatic waters related to the Tertiary volcanic activity. The thorium minerals are genetically related to the intrusion of pegmatite and plutonic crystalline rocks. None of the known deposits of radioactive minerals in California contain marketable reserves of uranium or thorium ore under economic conditions existing in 1952. With a favorable local market small lots of uranium ore may be available in the following places: the Rosamund prospect, the Rafferty and Chilson properties, the Lucky Star claim, and the Yerih group. The commercial production of thorium minerals will be possible, in the near future, only if these minerals can be recovered cheaply as a byproduct either from the mining of rare earths minerals at Mountain Pass or as a byproduct of placer mining for gold.

Integrated geophysical investigations for the delineation of source and subsurface structure associated with hydro-uranium anomaly: A case study from South Purulia Shear Zone (SPSZ), India

NASA Astrophysics Data System (ADS)

Sharma, S. P.; Biswas, A.

2012-12-01

South Purulia Shear Zone (SPSZ) is an important region for prospecting of uranium mineralization. Geological studies and hydro-uranium anomaly suggest the presence of Uranium deposit around Raghunathpur village which lies about 8 km north of SPSZ. However, detailed geophysical investigations have not been carried out in this region for investigation of uranium mineralization. Since surface signature of uranium mineralization is not depicted near the location, a deeper subsurface source is expected for hydro uranium anomaly. To delineate the subsurface structure and to investigate the origin of hydro-uranium anomaly present in the area, Vertical Electrical Sounding (VES) using Schlumberger array and Gradient Resistivity Profiling (GRP) were performed at different locations along a profile perpendicular to the South Purulia Shear Zone. Apparent resistivity computed from the measured sounding data at various locations shows a continuously increasing trend. As a result, conventional apparent resistivity data is not able to detect the possible source of hydro uranium anomaly. An innovative approach is applied which depicts the apparent conductivity in the subsurface revealed a possible connection from SPSZ to Raghunathpur. On the other hand resistivity profiling data suggests a low resistive zone which is also characterized by low Self-Potential (SP) anomaly zone. Since SPSZ is characterized by the source of uranium mineralization; hydro-uranium anomaly at Raghunathpur is connected with the SPSZ. The conducting zone has been delineated from SPSZ to Raghunathpur at deeper depths which could be uranium bearing. Since the location is also characterized by a low gravity and high magnetic anomaly zone, this conducting zone is likely to be mineralized zone. Keywords: Apparent resistivity; apparent conductivity; Self Potential; Uranium mineralization; shear zone; hydro-uranium anomaly.

Radionuclides and radiation doses in heavy mineral sands and other mining operations in Mozambique.

PubMed

Carvalho, Fernando P; Matine, Obete F; Taímo, Suzete; Oliveira, João M; Silva, Lídia; Malta, Margarida

2014-01-01

Sites at the littoral of Mozambique with heavy mineral sands exploited for ilmenite, rutile and zircon and inland mineral deposits exploited for tantalite, uranium and bauxite were surveyed for ambient radiation doses, and samples were collected for the determination of radionuclide concentrations. In heavy mineral sands, (238)U and (232)Th concentrations were 70±2 and 308±9 Bq kg(-1) dry weight (dw), respectively, whereas after separation of minerals, the concentrations in the ilmenite fraction were 2240±64 and 6125±485 Bq kg(-1) (dw), respectively. Tantalite displayed the highest concentrations with 44 738±2474 Bq kg(-1) of (238)U. Radiation exposure of workers in mining facilities is likely to occur at levels above the dose limit for members of the public (1 mSv y(-1)) and therefore radiation doses should be assessed as occupational exposures. Local populations living in these regions in general are not exposed to segregated minerals with high radionuclide concentrations. However, there is intensive artisanal mining and a large number of artisanal miners and their families may be exposed to radiation doses exceeding the dose limit. A radiation protection programme is therefore needed to ensure radiation protection of the public and workers of developing mining projects.

Incidence of non-lung solid cancers in Czech uranium miners: a case-cohort study

PubMed Central

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

2011-01-01

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 Příbram 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. PMID:21256480

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

PubMed

Kulich, M; Reřicha, V; Reřicha, R; Shore, D L; Sandler, D P

2011-04-01

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 Příbram region, Czech Republic. 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. 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. 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. Copyright © 2011 Elsevier Inc. All rights reserved.

Behavior of uranium under conditions of interaction of rocks and ores with subsurface water

NASA Astrophysics Data System (ADS)

Omel'Yanenko, B. I.; Petrov, V. A.; Poluektov, V. V.

2007-10-01

The behavior of uranium during interaction of subsurface water with crystalline rocks and uranium ores is considered in connection with the problem of safe underground insulation of spent nuclear fuel (SNF). Since subsurface water interacts with crystalline rocks formed at a high temperature, the mineral composition of these rocks and uranium species therein are thermodynamically unstable. Therefore, reactions directed toward the establishment of equilibrium proceed in the water-rock system. At great depths that are characterized by hindered water exchange, where subsurface water acquires near-neutral and reducing properties, the interaction is extremely sluggish and is expressed in the formation of micro- and nanoparticles of secondary minerals. Under such conditions, the slow diffusion redistribution of uranium with enrichment in absorbed forms relative to all other uranium species is realized as well. The products of secondary alteration of Fe- and Ti-bearing minerals serve as the main sorbents of uranium. The rate of alteration of minerals and conversion of uranium species into absorbed forms is slow, and the results of these processes are insignificant, so that the rocks and uranium species therein may be regarded as unaltered. Under reducing conditions, subsurface water is always saturated with uranium. Whether water interacts with rock or uranium ore, the equilibrium uranium concentration in water is only ≤10-8 mol/l. Uraninite ore under such conditions always remains stable irrespective of its age. The stability conditions of uranium ore are quite suitable for safe insulation of SNF, which consists of 95% uraninite (UO2) and is a confinement matrix for all other radionuclides. The disposal of SNF in massifs of crystalline rocks at depths below 500 m, where reducing conditions are predominant, is a reliable guarantee of high SNF stability. Under oxidizing conditions of the upper hydrodynamic zone, the rate of interaction of rocks with subsurface water increases by orders of magnitude and subsurface water is commonly undersaturated with uranium. Uranium absorbed by secondary minerals, particularly by iron hydroxides and leucoxene, is its single stable species under oxidizing conditions. The impact of oxygen-bearing water leads to destruction of uranium ore. This process is realized simultaneously at different hypsometric levels even if the permeability of the medium is variable in both the lateral and vertical directions. As a result, intervals containing uranyl minerals and relics of primary uranium ore are combined in ore-bearing zones with intervals of completely dissolved uranium minerals. A wide halo of elevated uranium contents caused by sorption is always retained at the location of uranium ore entirely destroyed by weathering. Uranium ore commonly finds itself in the aeration zone due to technogenic subsidence of the groundwater table caused by open-pit mining or pumping out of water from underground mines. The capillary and film waters that interact with rocks and ores in this zone are supplemented by free water filtering along fractures when rain falls or snow is thawing. The interaction of uranium ore with capillary water results in oxidation of uraninite, accompanied by loosening of the mineral surface, formation of microfractures, and an increase in solubility with enrichment of capillary water in uranium up to 10-4 mol/l. Secondary U(VI) minerals, first of all, uranyl hydroxides and silicates, replace uraninite, and uranium undergoes local diffusion redistribution with its sorption by secondary minerals of host rocks. The influx of free water facilitates the complete dissolution of primary and secondary uranium minerals, the removal of uranium at the sites of groundwater discharge, and its redeposition under reducing conditions at a greater depth. It is evident that the conditions of the upper hydrodynamic zone and the aeration zone are unfit for long-term insulation of SNF and high-level wastes because, after the failure of containers, the leakage of radionuclides into the environment becomes inevitable.

The origin of the Avram Iancu U-Ni-Co-Bi-As mineralization, Băiţa (Bihor) metallogenic district, Bihor Mts., Romania

NASA Astrophysics Data System (ADS)

Zajzon, Norbert; Szentpéteri, Krisztián; Szakáll, Sándor; Kristály, Ferenc

2015-10-01

The Băiţa metallogenic district in the Bihor Mountains is a historically important mining area in Romania. Uranium mining took place between 1952 and 1998 from various deposits, but very little is known about the geology and mineralogy of these deposits. In this paper, we describe geology and mineralogy of uranium mineralization of the Avram Iancu uranium mine from waste dump samples collected before complete remediation of the site. Texturally and mineralogically complex assemblages of nickeline, cobaltite-gersdorffite solid solution, native Bi, Bi-sulfosalts, molybdenite, and pyrite-chalcopyrite-sphalerite occur with uraninite, "pitchblende," and brannerite in most of the ore samples. The association of nickel, cobalt, and arsenic with uranium is reminiscent of five-element association of vein type U-Ni-Co-Bi-As deposits; however, the Avram Iancu ores appear to be more replacement-type stratiform/stratabound. Avram Iancu ore samples contain multistage complex, skarn, uranium sulfide, arsenide assemblages that can be interpreted to have been formed in the retrograde cooling stages of the skarn hydrothermal system. This mineralizing system may have built-up along Upper Cretaceous-Paleogene "Banatite" intrusions of diorite-to-granite composition. The intrusions crosscut the underlying uraniferous Permian formations in the stacked NW-verging Biharia Nappe System. The mineralization forms stacked, multilayer replacement horizons, along carbonate-rich lithologies within the metavolcanic (tuffaceous) Muncel Series. Mineral paragenesis and some mineral chemistry suggest moderate-to-high <450, i.e., 350-310 °C, formation temperatures for the uranium sulfide stage along stratigraphically controlled replacement zones and minor veins. Uranium minerals formed abundantly in this early stage and include botryoidal, sooty and euhedral uraninite, brannerite, and coffinite. Later and/or lower-temperature mineral assemblages include heterogeneous, complexly zoned arsenide-sulfarsenide solid solutions associated with minute but abundant uranium minerals. Within the later arsenide-sulfarsenide mineral assemblage, there is great variation in Ni, Co, and S content with generally increasing arsenic content. Uranium minerals in this late-stage assemblage include very fine euhedral uraninite and brannerite inclusions in arsenide-sulfarsenide minerals. Native bismuth and Bi-sulfosalt krupkaite are observed in this As-S-rich assemblage strongly associated with cobaltite.

Incorporation of Uranium into Hematite during Crystallization from Ferrihydrite

PubMed Central

2014-01-01

Ferrihydrite was exposed to U(VI)-containing cement leachate (pH 10.5) and aged to induce crystallization of hematite. A combination of chemical extractions, TEM, and XAS techniques provided the first evidence that adsorbed U(VI) (≈3000 ppm) was incorporated into hematite during ferrihydrite aggregation and the early stages of crystallization, with continued uptake occurring during hematite ripening. Analysis of EXAFS and XANES data indicated that the U(VI) was incorporated into a distorted, octahedrally coordinated site replacing Fe(III). Fitting of the EXAFS showed the uranyl bonds lengthened from 1.81 to 1.87 Å, in contrast to previous studies that have suggested that the uranyl bond is lost altogether upon incorporation into hematite. The results of this study both provide a new mechanistic understanding of uranium incorporation into hematite and define the nature of the bonding environment of uranium within the mineral structure. Immobilization of U(VI) by incorporation into hematite has clear and important implications for limiting uranium migration in natural and engineered environments. PMID:24580024

Enhanced uranium immobilization and reduction by Geobacter sulfurreducens biofilms.

PubMed

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

2014-11-01

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. Copyright © 2014, American Society for Microbiology. All Rights Reserved.

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

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.

Identification of Uranyl Minerals Using Oxygen K-Edge X Ray Absorption Spectroscopy

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

Ward, Jesse D.; Bowden, Mark E.; Resch, Charles T.

2016-03-01

Uranium analysis is consistently needed throughout the fuel cycle, from mining to fuel fabrication to environmental monitoring. Although most of the world’s uranium is immobilized as pitchblende or uraninite, there exists a plethora of secondary uranium minerals, nearly all of which contain the uranyl cation. Analysis of uranyl compounds can provide clues as to a sample’s facility of origin and chemical history. X-ray absorption spectroscopy is one technique that could enhance our ability to identify uranium minerals. Although there is limited chemical information to be gained from the uranium X-ray absorption edges, recent studies have successfully used ligand NEXAFS tomore » study the physical chemistry of various uranium compounds. This study extends the use of ligand NEXAFS to analyze a suite of uranium minerals. We find that major classes of uranyl compounds (carbonate, oxyhydroxide, silicate, and phosphate) exhibit characteristic lineshapes in the oxygen K-edge absorption spectra. As a result, this work establishes a library of reference spectra that can be used to classify unknown uranyl minerals.« less

A preliminary report on the geology of the Dennison-Bunn uranium claim, Sandoval County, New Mexico

USGS Publications Warehouse

Ridgley, Jennie L.

1978-01-01

Uranium at the Dennison-Bunn claim, south of Cuba, N. Mex., along the east margin of the San Juan Basin, occurs in unoxidized gray, fluvial channel sandstone of the Westwater Canyon Member of the Upper Jurassic Morrison Formation. The uranium-bearing sandstone is bounded on the north and south by a variable zone of buff and orange sandstone. Within the mineralized zone, the uranium has been remobilized and reconcentrated along the margins of numerous smaller tongues of oxidized rock in a configuration similar to that found in roll-type uranium deposits. In cross section, these small-scale features are zoned; they have an inner, pale orange, oxidized core, a mineralized redox rim cemented with hematite(?), and an outer-shell of -gray, slightly to moderately mineralized rock. The uranium content in the mineralized rock ranges from 0.001 to 0.07 percent U3O8. The uranium, at this locality, is believed to have originated within the Westwater Canyon Member or to have been derived from the overlying Brushy Basin Member. Based on observed outcrop relations, two hypotheses are proposed for explaining the origin of the occurrence. Briefly these hypotheses are: (1) the mineralized zone represents the remnant of an original roll-type uranium deposit, formed during early Eocene time, which has undergone subsequent oxidation with remobilization and redeposition of uranium around the margins of smaller tongues of oxidized rock; and (2) the mineralized zone represents the remnant of an original tabular deposit which has undergone subsequent oxidation with remobilization and redeposition of uranium around the margins of smaller tongues of oxidized rock.

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 precipitation in the form of U6+ minerals. The δ238U values of uranium ore minerals from a variety of deposits are controlled by the isotopic signature of the uranium source, the efficiency of uranium reduction in the case of UO2 systems, and the degree to which uranium was previously removed from the fluid, with less influence from temperature of ore formation and later alteration of the ore. Uranium isotopes are potentially superb tracers of redox in natural systems.

ASTER, ALI and Hyperion sensors data for lithological mapping and ore minerals exploration.

PubMed

Beiranvand Pour, Amin; Hashim, Mazlan

2014-01-01

This paper provides a review of the Advanced Spaceborne Thermal Emission and Reflection Radiometer (ASTER), Advanced Land Imager (ALI), and Hyperion data and applications of the data as a tool for ore minerals exploration, lithological and structural mapping. Spectral information extraction from ASTER, ALI, and Hyperion data has great ability to assist geologists in all disciplines to map the distribution and detect the rock units exposed at the earth's surface. The near coincidence of Earth Observing System (EOS)/Terra and Earth Observing One (EO-1) platforms allows acquiring ASTER, ALI, and Hyperion imagery of the same ground areas, resulting accurate information for geological mapping applications especially in the reconnaissance stages of hydrothermal copper and gold exploration, chromite, magnetite, massive sulfide and uranium ore deposits, mineral components of soils and structural interpretation at both regional and district scales. Shortwave length infrared and thermal infrared bands of ASTER have sufficient spectral resolution to map fundamental absorptions of hydroxyl mineral groups and silica and carbonate minerals for regional mapping purposes. Ferric-iron bearing minerals can be discriminated using six unique wavelength bands of ALI spanning the visible and near infrared. Hyperion visible and near infrared bands (0.4 to 1.0 μm) and shortwave infrared bands (0.9 to 2.5 μm) allowed to produce image maps of iron oxide minerals, hydroxyl-bearing minerals, sulfates and carbonates in association with hydrothermal alteration assemblages, respectively. The techniques and achievements reviewed in the present paper can further introduce the efficacy of ASTER, ALI, and Hyperion data for future mineral and lithological mapping and exploration of the porphyry copper, epithermal gold, chromite, magnetite, massive sulfide and uranium ore deposits especially in arid and semi-arid territory.

Hydrogeochemical and stream sediment reconnaissance basic data for Brownsville-McAllen NTMS Quadrangles, Texas

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

Not Available

1980-09-30

Results of a reconnaissance geochemical survey of the Brownsville-McAllen Quadrangles, Texas are reported. Field and laboratory data are presented for 427 groundwater and 171 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. Pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate the most promising area for potential uranium mineralization occurs in the northwestern section of the quadrangles (Jim Hogg, Starr, and Zapata Counties), where waters are derived from the Catahoula Formation. These groundwaters have high concentrations of uranium, uranium associated elements,more » and low values for specific conductance. Another area with high uranium concentrations is in the southeastern portion of the survey area (Hidalgo, Cameron, and Willacy Counties). Shallow wells <10 m (30 ft) are numerous in this area and high specific conductance values may indicate contamination from extensive fertilization. Stream sediment data for the survey does not indicate an area favorable for uranium mineralization. Anomalous acid soluble uranium values in the southeastern area (Hidalgo, Cameron, and Willacy Counties) can be attributed to phosphate fertilizer contamination. Four samples in the western part of the area (western Starr County) have anomalously high total uranium values and low acid soluble uranium values, indicating the uranium may be contained in resistate minerals.« less

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

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

PubMed

Jones, Benjamin A

2014-10-01

Uranium mining is associated with lung cancer and other health problems among miners. Health impacts are related with miner exposure to radon gas progeny. 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. 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. 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. 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.

Potential Aquifer Vulnerability in Regions Down-Gradient from ...

EPA Pesticide Factsheets

Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are instrumental in leaching uranium from source rocks and transporting it in low concentrations to a chemical redox interface where it is deposited in an ore zone typically containing the uranium minerals uraninite, pitchblende, and/or coffinite; various iron sulfides; native selenium; clays; and calcite. In situ recovery (ISR) of these uranium ores is a process of contacting the uranium mineral deposit with leaching (lixiviant) fluids via injection of the lixiviant into wells drilled into the subsurface aquifer that hosts uranium ore, while other extraction wells pump the dissolved uranium after dissolution of the uranium minerals. Environmental concerns during and after ISR include water quality impacts from: 1) potential excursions of leaching solutions away from the injection zone into down-dip, underlying, or overlying aquifers; 2) potential migration of uranium and its decay products (e.g., Ra, Rn, Pb); and, 3) potential migration of redox-sensitive trace metals (e.g., Fe, Mn, Mo, Se, V), metalloids (e.g., As), and anions (e.g., sulfate). This review describes the geochemical processes that control roll-front uranium transport and fate in groundwater systems, identifies potential aquifer vulnerabilities to ISR operations, identifies

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

Loomis, D.P.

The exfoliated-cell micronucleus assay is a relatively new cytogenetic technique which can provide a measure of the genetic effect of exposure to carcinogens and mutagens in target tissues where tumors arise among exposed populations. It is responsive to the effects of ionizing radiation and tobacco smoke in some in vivo human cell systems, but has not been extensively field tested as an indicator of lung cancer-related effects, despite the public health importance of exposure to occupational and environmental lung carcinogens. In this study the exfoliated-cell micronucleus assay was used to assess effects of exposure to radon progeny and cigarette smokemore » in a population of uranium industry workers (including employees in underground and open-pit mines, mills, laboratories, and administrative offices); underground uranium miners experience markedly elevated lung cancer risk because of exposure to ionizing radiation from radon progeny. Ninety-nine workers were selected at random from among workers in Colorado Plateau uranium-related facilities who participated in a workplace sputum cytology screening program from 1964-1988. The prevalence of cells with micronuclei was determined by a manual assay of one sputum specimen for each worker under a light microscope. Occupational and smoking data obtained by interview during screening were used to classify exposure and smoking status at the time the sputum specimen was taken and to obtain information on potential confounders and effect modifiers; underground miners were classified as exposed to radon progeny, and others were considered unexposed. Neither radon progeny exposure nor cigarette smoking had any appreciable effect on the prevalence of micronucleated cells. Crude prevalence ratios were 1.0 (95% CI 0.7-1.4) and 0.9 (95% CI 0.6-1.3), respectively, for radon exposure and smoking.« less

Potential for U sequestration with select minerals and sediments via base treatment.

PubMed

Emerson, Hilary P; Di Pietro, Silvina; Katsenovich, Yelena; Szecsody, Jim

2018-06-13

Temporary base treatment is a potential remediation technique for heavy metals through adsorption, precipitation, and co-precipitation with minerals. Manipulation of pH with ammonia gas injection may be especially useful for vadose zone environments as it does not require addition of liquids that would increase the flux towards groundwater. In this research, we conducted laboratory batch experiments to evaluate the changes in uranium mobility and mineral dissolution with base treatments including sodium hydroxide, ammonium hydroxide, and ammonia gas. Our data show that partitioning of uranium to the solid phase increases by several orders of magnitude following base treatment in the presence of different minerals and natural sediments from the Hanford site. The presence of dissolved calcium and carbonate play an important role in precipitation and co-precipitation of uranium at elevated pH. In addition, significant incongruent dissolution of bulk mineral phases occurs and likely leads to precipitation of secondary mineral phases. These secondary phases may remove uranium via adsorption, precipitation, and co-precipitation processes and may coat uranium phases with low solubility minerals as the pH returns to natural conditions. Copyright © 2018 Elsevier Ltd. All rights reserved.

Ground gamma-ray spectrometric studies of El-Sahu area, southwestern Sinai, Egypt

NASA Astrophysics Data System (ADS)

Abdrabboh, Ahmad M.

2017-12-01

Based on the previous airborne gamma-ray spectrometric study carried out in southwestern Sinai area, El Sahu area was selected for detail ground gamma-ray spectrometric survey. This area is considered as a good target for radioactive mineral exploration. The study area is exposed in a Paleozoic basin covered by different rocks (ranging from Precambrian to Quaternary). The ground gamma-ray spectrometric survey has been conducted along the study area through random survey. The resultant gamma-ray spectrometric maps show different levels of radioactivity over the studied area, which reflect contrasting radioelement contents for the exposed various rock types. The studied area possesses total count ranging from 2.6 to 326 Ur, 0.1 to 2.8% K, 1.7 to 316 ppm eU and 0.9 to 47.5 ppm eTh. The highest uranium concentrations are located in the northern and southern parts of El Sahu area. They are mainly associated with Um Bogma Formation occurrences. Uranium ratio maps (eU/K and eU/eTh) as well as ternary maps show sharp increase of eU content over both potassium and thorium contents associated with the ENE and NNW trends in Um Bogma Formation, indicating an increase in the U-potentiality than the surrounding rocks. This indicates that the mineralization in the study area may be structurally-controlled.

The formation of technic soil in a revegetated uranium ore waste rock pile (Limousin, France)

NASA Astrophysics Data System (ADS)

Boekhout, Flora; Gérard, Martine; Kanzari, Aisha; Calas, Georges; Descostes, Michael

2014-05-01

Mining took place in France between 1945 and 2001 during which time ~210 different sites were exploited and/or explored. A total of 76 Kt of uranium was produced, 52 Mt of ore was extracted, but also 200 Mt of waste rocks was produced, the majority of which, with uranium levels corresponding to the natural environment. So far, the processes of arenisation and technic soil formation in waste rock piles are not well understood but have important implications for understanding the environmental impact and long-term speciation of uranium. Understanding weathering processes in waste rock piles is essential to determine their environmental impact. The main objectives of this work are to assess 1) the micromorphological features and neo-formed U-bearing phases related to weathering and 2) the processes behind arenisation of the rock pile. The site that was chosen is the Vieilles Sagnes waste rock pile in Fanay (Massif Central France) that represents more or less hydrothermally altered granitic rocks that have been exposed to weathering since the construction of the waste rock pile approximately 50 years ago. Two trenches were excavated to investigate the vertical differentiation of the rock pile. This site serves as a key location for studying weathering processes of waste rock piles, as it has not been reworked after initial construction and has therefore preserved information on the original mineralogy of the waste rock pile enabling us to access post emplacement weathering processes. The site is currently overgrown by moss, meter high ferns and small trees. At present day the rock pile material can be described as hydrothermally altered rocks and rock fragments within a fine-grained silty clay matrix exposed to surface conditions and weathering. A sandy "paleo" technic soil underlies the waste rock pile and functions as a natural liner by adsorption of uranium on clay minerals. Post-mining weathering of rock-pile material is superimposed on pre-mining hydrothermal and possible supergene alteration. Clay minerals present are kaolinite, smectite and chlorite. The formation of these minerals is however ambiguous, and can form during both hydrothermal as weathering processes, calling for a detailed micromorphological study. Micromorphological investigations on undisturbed samples by microscopic and ultramicroscopic techniques allow us to interpretate the processes behind the formation of technic soil in the matrix of the waste rock pile, as well as the rate and chronology of mineral formation and arenisation related to weathering (formation of protosoil and saprolitisation). By studying the formation of weathering aureaoles in between the different granitic blocks, we quantify the anthropogenic influence on weathering of this rock pile and their impacts on local ecosystem by comparing our site with natural occuring outcrops of granites currently subjected to weathering. Electron microscope imaging and microgeochemical mapping permits us to make detailed micromorphological observations linking nanoscale processes to petrolographical macroscopic features and field observations. Different petrographic and electronic images of the mineral paragenesis in the micromass associated to their microgeochemical characteristics will be presented. Also, the impact of previous hydrothermal alteration will be highlighted.

Identification of Uranium Minerals in Natural U-Bearing Rocks Using Infrared Reflectance Spectroscopy

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

Beiswenger, Toya N.; Gallagher, Neal B.; Myers, Tanya L.

The identification of minerals, including uranium-bearing minerals, is traditionally a labor-intensive-process using x-ray diffraction (XRD), fluorescence, or other solid-phase and wet chemical techniques. While handheld XRD and fluorescence instruments can aid in field identification, handheld infrared reflectance spectrometers can also be used in industrial or field environments, with rapid, non-destructive identification possible via spectral analysis of the solid’s reflectance spectrum. We have recently developed standard laboratory measurement methods for the infrared (IR) reflectance of solids and have investigated using these techniques for the identification of uranium-bearing minerals, using XRD methods for ground-truth. Due to the rich colors of such species,more » including distinctive spectroscopic signatures in the infrared, identification is facile and specific, both for samples that are pure or are partially composed of uranium (e.g. boltwoodite, schoepite, tyuyamunite, carnotite, etc.) or non-uranium minerals. The method can be used to detect not only pure and partial minerals, but is quite sensitive to chemical change such as hydration (e.g. schoepite). We have further applied statistical methods, in particular classical least squares (CLS) and multivariate curve resolution (MCR) for discrimination of such uranium minerals and two uranium pure chemicals (U3O8 and UO2) against common background materials (e.g. silica sand, asphalt, calcite, K-feldspar) with good success. Each mineral contains unique infrared spectral features; some of the IR features are similar or common to entire classes of minerals, typically arising from similar chemical moieties or functional groups in the minerals: phosphates, sulfates, carbonates, etc. These characteristic 2 infrared bands generate the unique (or class-specific) bands that distinguish the mineral from the interferents or backgrounds. We have observed several cases where the chemical moieties that provide the spectral discrimination in the longwave IR do so by generating upward-going reststrahlen bands in the reflectance data, but the same minerals have other weaker (overtone) bands, sometimes from the same chemical groups, that are manifest as downward-going transmission-type features in the midwave and shortwave infrared.« less

Uranium provinces of North America; their definition, distribution, and models

USGS Publications Warehouse

Finch, Warren Irvin

1996-01-01

Uranium resources in North America are principally in unconformity-related, quartz-pebble conglomerate, sandstone, volcanic, and phosphorite types of uranium deposits. Most are concentrated in separate, well-defined metallogenic provinces. Proterozoic quartz-pebble conglomerate and unconformity-related deposits are, respectively, in the Blind River–Elliot Lake (BRELUP) and the Athabasca Basin (ABUP) Uranium Provinces in Canada. Sandstone uranium deposits are of two principal subtypes, tabular and roll-front. Tabular sandstone uranium deposits are mainly in upper Paleozoic and Mesozoic rocks in the Colorado Plateau Uranium Province (CPUP). Roll-front sandstone uranium deposits are in Tertiary rocks of the Rocky Mountain and Intermontane Basins Uranium Province (RMIBUP), and in a narrow belt of Tertiary rocks that form the Gulf Coastal Uranium Province (GCUP) in south Texas and adjacent Mexico. Volcanic uranium deposits are concentrated in the Basin and Range Uranium Province (BRUP) stretching from the McDermitt caldera at the Oregon-Nevada border through the Marysvale district of Utah and Date Creek Basin in Arizona and south into the Sierra de Peña Blanca District, Chihuahua, Mexico. Uraniferous phosphorite occurs in Tertiary sediments in Florida, Georgia, and North and South Carolina and in the Lower Permian Phosphoria Formation in Idaho and adjacent States, but only in Florida has economic recovery been successful. The Florida Phosphorite Uranium Province (FPUP) has yielded large quantities of uranium as a byproduct of the production of phosphoric acid fertilizer. Economically recoverable quantities of copper, gold, molybdenum, nickel, silver, thorium, and vanadium occur with the uranium deposits in some provinces.Many major epochs of uranium mineralization occurred in North America. In the BRELUP, uranium minerals were concentrated in placers during the Early Proterozoic (2,500–2,250 Ma). In the ABUP, the unconformity-related deposits were most likely formed initially by hot saline formational water related to diagenesis (»1,400 to 1,330 Ma) and later reconcentrated by hydrothermal events at »1,280–»1,000, »575, and »225 Ma. Subsequently in North America, only minor uranium mineralization occurred until after continental collision in Permian time (255 Ma). Three principal epochs of uranium mineralization occurred in the CPUP: (1) » 210–200 Ma, shortly after Late Triassic sedimentation; (2) »155–150 Ma, in Late Jurassic time; and (3) » 135 Ma, after sedimentation of the Upper Jurassic Morrison Formation. The most likely source of the uranium was silicic volcaniclastics for the three epochs derived from a volcanic island arc at the west edge of the North American continent. Uranium mineralization occurred during Eocene, Miocene, and Pliocene times in the RMIBUP, GCUP, and BRUP. Volcanic activity took place near the west edge of the continent during and shortly after sedimentation of the host rocks in these three provinces. Some volcanic centers in the Sierra de Peña Blanca district within the BRUP may have provided uranium-rich ash to host rocks in the GCUP.Most of the uranium provinces in North America appear to have a common theme of close associations to volcanic activity related to the development of the western margin of the North American plate. The south and west margin of the Canadian Shield formed the leading edge of the progress of uranium source development and mineralization from the Proterozoic to the present. The development of favorable hosts and sources of uranium is related to various tectonic elements developed over time. Periods of major uranium mineralization in North America were Early Proterozoic, Middle Proterozoic, Late Triassic–Early Jurassic, Early Cretaceous, Oligocene, and Miocene. Tertiary mineralization was the most pervasive, covering most of Western and Southern North America. 

Potential aquifer vulnerability in regions down-gradient from uranium in situ recovery (ISR) sites.

PubMed

Saunders, James A; Pivetz, Bruce E; Voorhies, Nathan; Wilkin, Richard T

2016-12-01

Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are important in leaching uranium from source rocks and transporting it in low concentrations to a chemical redox interface where it is deposited in an ore zone typically containing the uranium minerals uraninite, pitchblende, and/or coffinite; various iron sulfides; native selenium; clays; and calcite. In situ recovery (ISR) of uranium ores is a process of contacting the uranium mineral deposit with leaching and oxidizing (lixiviant) fluids via injection of the lixiviant into wells drilled into the subsurface aquifer that hosts uranium ore, while other extraction wells pump the dissolved uranium after dissolution of the uranium minerals. Environmental concerns during and after ISR include water quality degradation from: 1) potential excursions of leaching solutions away from the injection zone into down-gradient, underlying, or overlying aquifers; 2) potential migration of uranium and its decay products (e.g., Ra, Rn, Pb); and, 3) potential mobilization and migration of redox-sensitive trace metals (e.g., Fe, Mn, Mo, Se, V), metalloids (e.g., As), and anions (e.g., sulfate). This review describes the geochemical processes that control roll-front uranium transport and fate in groundwater systems, identifies potential aquifer vulnerabilities to ISR operations, identifies data gaps in mitigating these vulnerabilities, and discusses the hydrogeological characterization involved in developing a monitoring program. Published by Elsevier Ltd.

Observational studies as human experimentation: the uranium mining experience in the Navajo Nation (1947-66).

PubMed

Moure-Eraso, R

1999-01-01

This article evaluates how an observational epidemiologic study of federal agencies in uranium miners became an experiment of opportunity for radiation effects. Navajo miners and communities suffered environmental exposures caused by the practices of uranium mining and milling in the Navajo reservation during the 1947 to 1966 period. A historical review of the state-of-the-art knowledge of the health effects of uranium mining and milling during the years prior to 1947 was conducted. Contemporary prevention and remediation practices also were assessed. An appraisal of the summary of findings of a comprehensive evaluation of radiation human experimentation conducted by the U.S. federal government in 1995-96 (ACHRE) demonstrates that uranium miners, including Navajo miners, were the single group that was put more seriously at risk of harm from radiation exposures, with inadequate disclosure and often with fatal consequences. Uranium miners were unwilling and unaware victims of human experimentation to evaluate the health effects of radiation. The failure of the State and U.S. Governments to issue regulations or demand installation of known mine-dust exposure control measures caused widespread environmental damage in the Navajo Nation.

Leukemia and exposure to ionizing radiation among German uranium miners.

PubMed

Möhner, Matthias; Lindtner, Manfred; Otten, Heinz; Gille, Hans-G

2006-04-01

It is well known that uranium miners are at an increased risk of lung cancer. Whether they also have an increased risk for other cancer sites remains under discussion. The aim of this study was to examine the leukemia risk among miners. An individually matched case-control study of former uranium miners in East Germany was conducted with 377 cases and 980 controls. Using conditional logistic regression models, a dose-response relationship between leukemia risk and radon progeny could not be confirmed. Yet, a significantly elevated risk is seen in the category > or = 400 mSv when combining gamma-radiation and long-lived radionuclides. The results suggest that an elevated risk for leukemia is restricted to employees with a very long occupational career in underground uranium mining or uranium processing. Moreover, the study does not support the hypothesis of an association between exposure to short-lived radon progeny and leukemia risk. Copyright 2006 Wiley-Liss, Inc.

28 CFR 79.40 - Scope of subpart.

Code of Federal Regulations, 2011 CFR

2011-07-01

... ACT Eligibility Criteria for Claims by Uranium Miners § 79.40 Scope of subpart. The regulations in... miners, i.e., uranium mine workers, and the nature of the evidence that will be accepted as proof of the... exposure to a defined minimum level of radiation during employment in aboveground or underground uranium...

28 CFR 79.40 - Scope of subpart.

Code of Federal Regulations, 2013 CFR

2013-07-01

... ACT Eligibility Criteria for Claims by Uranium Miners § 79.40 Scope of subpart. The regulations in... miners, i.e., uranium mine workers, and the nature of the evidence that will be accepted as proof of the... exposure to a defined minimum level of radiation during employment in aboveground or underground uranium...

28 CFR 79.40 - Scope of subpart.

Code of Federal Regulations, 2012 CFR

2012-07-01

... ACT Eligibility Criteria for Claims by Uranium Miners § 79.40 Scope of subpart. The regulations in... miners, i.e., uranium mine workers, and the nature of the evidence that will be accepted as proof of the... exposure to a defined minimum level of radiation during employment in aboveground or underground uranium...

28 CFR 79.40 - Scope of subpart.

Code of Federal Regulations, 2010 CFR

2010-07-01

... ACT Eligibility Criteria for Claims by Uranium Miners § 79.40 Scope of subpart. The regulations in... miners, i.e., uranium mine workers, and the nature of the evidence that will be accepted as proof of the... exposure to a defined minimum level of radiation during employment in aboveground or underground uranium...

Uranium mineralization and unconformities: how do they correlate? - A look beyond the classic unconformity-type deposit model?

NASA Astrophysics Data System (ADS)

Markwitz, Vanessa; Porwal, Alok; Campbell McCuaig, T.; Kreuzer, Oliver P.

2010-05-01

Uranium deposits are usually classified based on the characteristics of their host rocks and geological environments (Dahlkamp, 1993; OECD/NEA Red Book and IAEA, 2000; Cuney, 2009). The traditional unconformity-related deposit types are the most economical deposits in the world, with the highest grades amongst all uranium deposit types. In order to predict undiscovered uranium deposits, there is a need to understand the spatial association of uranium mineralization with structures and unconformities. Hydrothermal uranium deposits develop by uranium enriched fluids from source rocks, transported along permeable pathways to their depositional environment. Unconformities are not only separating competent from incompetent sequences, but provide the physico-chemical gradient in the depositional environment. They acted as important fluid flow pathways for uranium to migrate not only for surface-derived oxygenated fluids, but also for high oxidized metamorphic and magmatic fluids, dominated by their geological environment in which the unconformities occur. We have carried out comprehensive empirical spatial analyses of various types of uranium deposits in Australia, and first results indicate that there is a strong spatial correlation between unconformities and uranium deposits, not only for traditional unconformity-related deposits but also for other styles. As a start we analysed uranium deposits in Queensland and in particular Proterozoic metasomatic-related deposits in the Mount Isa Inlier and Late Carboniferous to Early Permian volcanic-hosted uranium occurrences in Georgetown and Charters Towers Regions show strong spatial associations with contemporary and older unconformities. The Georgetown Inlier in northern Queensland consists of a diverse range of rocks, including Proterozoic and early Palaeozoic metamorphic rocks and granites and late Palaeozoic volcanic rocks and related granites. Uranium-molybdenum (+/- fluorine) mineralization in the Georgetown inlier varies from strata- to structure-bound and occurs above regional unconformities. The Proterozoic basins in the Mount Isa Inlier rest unconformably on Palaeoproterozoic basement accompanied by volcanic and igneous rocks, which were deformed and metamorphosed in the Mesoproterozoic. Uranium occurrences in the Western Succession of Mount Isa are either hosted in clastic metasediments or mafic volcanics that belong to the Palaeoproterozoic Eastern Creek Volcanics. Uranium and vanadium mineralization occur in metasomatised and hematite-magnetite-carbonate alteration zones, bounded by major faults and regional unconformities. The results of this study highlight the importance of unconformities in uranium minerals systems as possible fluid pathways and/or surfaces of physico-chemical contrast that could have facilitated the precipitation of uranium, not only in classical unconformity style uranium deposits but in several other styles of uranium mineralization as well. References Cuney, M., 2009. The extreme diversity of uranium deposits. Mineralium Deposita, 44, 3-9. Dahlkamp, F. J., 1993. Uranium ore deposits. Springer, Berlin, p 460. OECD / NEA Red Book & IAEA, 2000. Uranium 1999: Resources, Production and Demand. OECD Nuclear Energy Agency and International Atomic Energy Agency, Paris.

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

Saccomanno, G.

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 Hospitalmore » 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.« less

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

Saccomanno, G.

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 Hospitalmore » 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.« less

The social costs of uranium mining in the US Colorado Plateau cohort, 1960-2005.

PubMed

Jones, Benjamin A

2017-05-01

Long-term social costs associated with underground uranium mining are largely unknown. This study estimated health costs of Native American and white (Hispanic and non-Hispanic origin) uranium miners in the US Public Health Service Colorado Plateau cohort study. Elevated uranium miner person-years of life lost (PYLL) were calculated from the most recent study of the Colorado Plateau cohort over 1960-2005. Nine causes of death categories were included. Costs to society of miner PYLL were monetized using the value of a statistical life-year approach. Costs over 1960-2005 totaled $2 billion USD [95% CI: $1.8, $2.2], or $2.9 million per elevated miner death. This corresponds to $43.1 million [95%: $38.7, $48.7] in annual costs. Lung cancer was the most costly cause of death at $1.4 billion [95%: $1.3, $1.5]. Absolute health costs were largest for white miners, but Native Americans had larger costs per elevated death. Annual excess mortality over 1960-2005 averaged 366.4 per 100,000 miners; 404.6 (white) and 201.5 per 100,000 (Native American). This research advances our understanding of uranium extraction legacy impacts, particularly among indigenous populations.

Estimation of the reactive mineral surface area during CO2-rich fluid-rock interaction: the influence of neogenic phases

NASA Astrophysics Data System (ADS)

Scislewski, A.; Zuddas, P.

2010-12-01

Mineral dissolution and precipitation reactions actively participate to control fluid chemistry during water-rock interaction. It is however, difficult to estimate and well normalize bulk reaction rates if the mineral surface area exposed to the aqueous solution and effectively participating on the reactions is unknown. We evaluated the changing of the reactive mineral surface area during the interaction between CO2-rich fluids and Albitite/Granitoid rocks (similar mineralogy but different abundances), reacting under flow-through conditions. Our methodology, adopting an inverse modeling approach, is based on the estimation of dissolution rate and reactive surface area of the different minerals participating in the reactions by the reconstruction the chemical evolution of the interacting fluids. The irreversible mass-transfer processes is defined by a fractional degree of advancement, while calculations were carried out for Albite, Microcline, Biotite and Calcite assuming that the ion activity of dissolved silica and aluminium ions was limited by the equilibrium with quartz and kaolinite. Irrespective of the mineral abundance in granite and albitite, we found that mineral dissolution rates did not change significantly in the investigated range of time where output solution’s pH remained in the range between 6 and 8, indicating that the observed variation in fluid composition depends not on pH but rather on the variation of the parent mineral’s reactive surface area. We found that the reactive surface area of Albite varied by more than 2 orders of magnitude, while Microcline, Calcite and Biotite surface areas changed by 1-2 orders of magnitude. We propose that parent mineral chemical heterogeneity and, particularly, the stability of secondary mineral phases may explain the observed variation of the reactive surface area of the minerals. Formation of coatings at the dissolving parent mineral surfaces significantly reduced the amount of surface available to react with CO2-rich fluids, decreasing the effective reactive surface area. Predictive models of CO2 sequestration under geological conditions should take into account the inhibiting role of surface coating formation. The CO2 rich fluid-rock interactions may also have significant consequences on metal mobilization. Our results indicated that the formation of stable carbonate complexes enhances the solubility of uranium minerals of both albitite and granite, facilitating the U(IV) oxidation, and limiting the extent of uranium adsorption onto particles in oxidized waters. This clearly produces an increase of the uranium mobility with significant consequences for the environment.

Multisource geological data mining and its utilization of uranium resources exploration

NASA Astrophysics Data System (ADS)

Zhang, Jie-lin

2009-10-01

Nuclear energy as one of clear energy sources takes important role in economic development in CHINA, and according to the national long term development strategy, many more nuclear powers will be built in next few years, so it is a great challenge for uranium resources exploration. Research and practice on mineral exploration demonstrates that utilizing the modern Earth Observe System (EOS) technology and developing new multi-source geological data mining methods are effective approaches to uranium deposits prospecting. Based on data mining and knowledge discovery technology, this paper uses multi-source geological data to character electromagnetic spectral, geophysical and spatial information of uranium mineralization factors, and provides the technical support for uranium prospecting integrating with field remote sensing geological survey. Multi-source geological data used in this paper include satellite hyperspectral image (Hyperion), high spatial resolution remote sensing data, uranium geological information, airborne radiometric data, aeromagnetic and gravity data, and related data mining methods have been developed, such as data fusion of optical data and Radarsat image, information integration of remote sensing and geophysical data, and so on. Based on above approaches, the multi-geoscience information of uranium mineralization factors including complex polystage rock mass, mineralization controlling faults and hydrothermal alterations have been identified, the metallogenic potential of uranium has been evaluated, and some predicting areas have been located.

Virgin Valley opal district, Humboldt County, Nevada

USGS Publications Warehouse

Staatz, Mortimer Hay; Bauer, Herman L.

1951-01-01

The Virgin Valley opal district, Humboldt County, Nevada, is near the Oregon-Nevada border in the Sheldon Game Refuge. Nineteen claims owned by Jack and Toni Crane were examined, sampled, and tested radiometrically for uranium. Numerous discontinuous layers of opal are interbedded with a gently-dipping series of vitric tuff and ash which is at least 300 ft thick. The tuff and ash are capped by a dark, vesicular basalt in the eastern part of the area and by a thin layer of terrace qravels in the area along the west side of Virgin Valley. Silicification of the ash and tuff has produced a rock that ranges from partly opalized rock that resembles silicified shale to completely altered rock that is entirely translucent, and consists of massive, brown and pale-green opal. Carnotite, the only identified uranium mineral, occurs as fracture coatings or fine layers in the opal; in places, no uranium minerals are visible in the radioactive opal. The opal layers are irregular in extent and thickness. The exposed length of the layers ranges from 8 to 1, 200 ft or more, and the thickness of the layers ranges from 0. 1 to 3. 9 ft. The uranium content of each opal layer, and of different parts of the same layer, differs widely. On the east side of Virgin Valley four of the seven observed opal layers, nos. 3, 4, 5, and 7, are more radioactive than the average; and the uranium content ranges from 0. 002 to 0. 12 percent. Two samples, taken 5 ft apart across opal layer no. 7, contained 0. 003 and 0. -049 percent uranium. On the west side of the valley only four of the fifteen observed opal layers, nos; 9, , 10, 14, and 15, are more radioactive than the average; and the uranium content ranges from 0. 004 to 0. 047 percent. Material of the highest grade was found in a small discontinuous layer of pale-green opal (no. 4) on the east side of Virgin Valley. The grade of this layer ranged from 0. 027 to 0. 12 percent uranium.

Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments

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

Wang, Guohui; Um, Wooyong; Wang, Zheming

The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford’s cribs, USA. During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO2)(PO4)·3H2O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K2(UO2)6O4(OH)6·7H2O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitatedmore » as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67E-12 mol g-1 s-1. In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42E-10 mol g-1 s-1. The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.« less

Uranium Release from Acidic Weathered Hanford Sediments: Single-Pass Flow-Through and Column Experiments.

PubMed

Wang, Guohui; Um, Wooyong; Wang, Zheming; Reinoso-Maset, Estela; Washton, Nancy M; Mueller, Karl T; Perdrial, Nicolas; O'Day, Peggy A; Chorover, Jon

2017-10-03

The reaction of acidic radioactive waste with sediments can induce mineral transformation reactions that, in turn, control contaminant fate. Here, sediment weathering by synthetic uranium-containing acid solutions was investigated using bench-scale experiments to simulate waste disposal conditions at Hanford's cribs (Hanford, WA). During acid weathering, the presence of phosphate exerted a strong influence over uranium mineralogy and a rapidly precipitated, crystalline uranium phosphate phase (meta-ankoleite [K(UO 2 )(PO 4 )·3H 2 O]) was identified using spectroscopic and diffraction-based techniques. In phosphate-free system, uranium oxyhydroxide minerals such as K-compreignacite [K 2 (UO 2 ) 6 O 4 (OH) 6 ·7H 2 O] were formed. Single-pass flow-through (SPFT) and column leaching experiments using synthetic Hanford pore water showed that uranium precipitated as meta-ankoleite during acid weathering was strongly retained in the sediments, with an average release rate of 2.67 × 10 -12 mol g -1 s -1 . In the absence of phosphate, uranium release was controlled by dissolution of uranium oxyhydroxide (compreignacite-type) mineral with a release rate of 1.05-2.42 × 10 -10 mol g -1 s -1 . The uranium mineralogy and release rates determined for both systems in this study support the development of accurate U-release models for the prediction of contaminant transport. These results suggest that phosphate minerals may be a good candidate for uranium remediation approaches at contaminated sites.

Preliminary examination of uranium deposits near Marysvale, Piute County, Utah

USGS Publications Warehouse

Granger, Harry C.; Bauer, Herman L.

1950-01-01

Autunite and other uranium minerals were discovered in 1948 by Pratt Seegmiller about 3 1/4 miles north of Marysvale, Piute County, Utah. Mining operations were begun in the summer of 1949 by the Vanadium Corporation of America on the Prospector and the Freedom claims, and by the Bullion Monarch Mining Company a the Bullion Monarch claims. These claims were examined briefly in December 1949 and January 1950 by the writers. The uranium deposits of the Marysvale district are in north-easterly striking fault zones in quartz monzonite that intrudes rocks of the "older" Tertiary volcanic sequence. Flows and tuffs of the "younger" Tertiary volcanic sequence uncomfortably overlie the earlier rocks. Autunite, tobernite, uranophane, schroeckingerite, and at least one unidentified secondary uranium mineral occur in the upper parts of the deposits. Pitchblende has been mined from the underground workings of the Prospector No. 1 mine. The uranium minerals are associated with dense quartz veins and intensely argillized wall rock. In the upper parts of the deposits pyrite is completely oxidized. The secondary uranium minerals probably were formed by the alteration of primary pitchblende by circulating meteoric waters.

Occurrences of uranium-bearing minerals in the St. Kevin District, Lake County, Colorado

USGS Publications Warehouse

Pierson, C.T.; Singewald, Q.D.

1953-01-01

None of the uranium occurrences are of commercial importance. They are for the most part in non-glaciated terrane, which has been subjected to a very long period of weathering.  Thus, chemical leaching within the zone of weathering may have greatly reduced the uranium content of material near the surface, and occurrences of even small quantities of secondary uranium minerals might be related to stronger, primary concentrations at depth.

Uranium mining and lung cancer among Navajo men in New Mexico and Arizona, 1969 to 1993.

PubMed

Gilliland, F D; Hunt, W C; Pardilla, M; Key, C R

2000-03-01

Navajo men who were underground miners have excess risk of lung cancer. To further characterize the long-term consequences of uranium mining in this high-risk population, we examined lung cancer incidence among Navajo men residing in New Mexico and Arizona from 1969 to 1993 and conducted a population-based case-control study to estimate the risk of lung cancer for Navajo uranium miners. Uranium mining contributed substantially to lung cancer among Navajo men over the 25-year period following the end of mining for the Navajo Nation. Sixty-three (67%) of the 94-incident lung cancers among Navajo men occurred in former uranium miners. The relative risk for a history of mining was 28.6 (95% confidence interval, 13.2-61.7). Smoking did not account for the strong relationship between lung cancer and uranium mining. The Navajo experience with uranium mining is a unique example of exposure in a single occupation accounting for the majority of lung cancers in an entire population.

Identification of Uranium Minerals in Natural U-Bearing Rocks Using Infrared Reflectance Spectroscopy.

PubMed

Beiswenger, Toya N; Gallagher, Neal B; Myers, Tanya L; Szecsody, James E; Tonkyn, Russell G; Su, Yin-Fong; Sweet, Lucas E; Lewallen, Tricia A; Johnson, Timothy J

2018-02-01

The identification of minerals, including uranium-bearing species, is often a labor-intensive process using X-ray diffraction (XRD), fluorescence, or other solid-phase or wet chemical techniques. While handheld XRD and fluorescence instruments can aid in field applications, handheld infrared (IR) reflectance spectrometers can now also be used in industrial or field environments, with rapid, nondestructive identification possible via analysis of the solid's reflectance spectrum providing information not found in other techniques. In this paper, we report the use of laboratory methods that measure the IR hemispherical reflectance of solids using an integrating sphere and have applied it to the identification of mineral mixtures (i.e., rocks), with widely varying percentages of uranium mineral content. We then apply classical least squares (CLS) and multivariate curve resolution (MCR) methods to better discriminate the minerals (along with two pure uranium chemicals U 3 O 8 and UO 2 ) against many common natural and anthropogenic background materials (e.g., silica sand, asphalt, calcite, K-feldspar) with good success. Ground truth as to mineral content was attained primarily by XRD. Identification is facile and specific, both for samples that are pure or are partially composed of uranium (e.g., boltwoodite, tyuyamunite, etc.) or non-uranium minerals. The characteristic IR bands generate unique (or class-specific) bands, typically arising from similar chemical moieties or functional groups in the minerals: uranyls, phosphates, silicates, etc. In some cases, the chemical groups that provide spectral discrimination in the longwave IR reflectance by generating upward-going (reststrahlen) bands can provide discrimination in the midwave and shortwave IR via downward-going absorption features, i.e., weaker overtone or combination bands arising from the same chemical moieties.

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.

Geology of uranium in the Chadron area, Nebraska and South Dakota

USGS Publications Warehouse

Dunham, Robert Jacob

1961-01-01

The Chadron area covers 375 square miles about 25 miles southeast of the Black Hills. Recurrent mild tectonic activity and erosion on the Chadron arch, a compound anticlinal uplift of regional extent, exposed 1900 feet of Upper Cretaceous rocks, mostly marine shale containing pyrite and organic matter, and 600 feet of Oligocene and Miocene rocks, mostly terrestrial fine-grained sediment containing volcanic ash. Each Cretaceous formation truncated by the sub-Oligocene unconformity is stained yellow and red, leached, kaolinized, and otherwise altered to depths as great as 55 feet. The composition and profile of the altered material indicate lateritic soil; indirect evidence indicates Eocene(?) age. In a belt through the central part of the area, the Brule formation of Oligocene age is a sequence of bedded gypsum, clay, dolomite, and limestone more than 300 feet thick. Uranium in Cretaceous shale in 58 samples averages 0.002 percent, ten times the average for the earths crust. Association with pyrite and organic matter indicates low valency. The uranium probably is syngenetic or nearly so. Uranium in Eocene(?) soil in 43 samples averages 0.054 percent, ranging up to 1.12 percent. The upper part of the soil is depleted in uranium; enriched masses in the basal part of the soil consist of remnants of bedrock shale and are restricted to the highest reaches of the ancient oxidation-reduction interface. The uranium is probably in the from of a low-valent mineral, perhaps uraninite. Modern weathering of Cretaceous shale is capable of releasing as much as 0.780 ppm uranium to water. Eocene(?) weathering probably caused enrichment of the ancient soil through 1) leaching of Cretaceous shale, 2) downward migration of uranyl complex ions, and 3) reduction of hydrogen sulfide at the water table. Uranium minerals occur in the basal 25 feet of the gypsum facies of the Brule formation at the two localities where the gypsum is carbonaceous; 16 samples average 0.066 percent uranium and range up to 0.43 percent. Elsewhere uranium in dolomite and limestone in the basal 25 feet of the gypsum facies in 10 samples averages 0.007 percent, ranging up to 0.12 percent. Localization of the uranium at the base of the gypsum facies suggests downward moving waters; indirect evidence that the water from which the gypsum was deposited was highly alkaline suggests that the uranium was leached from volcanic ash in Oligocene time.

Geology of the area adjacent to the Free Enterprise uranium-silver Mine, Boulder District, Jefferson County, Montana

USGS Publications Warehouse

Roberts, W.A.; Gude, A.J.

1952-01-01

Uranium minerals.occur in pods associated with cryptocrystalline silica, silver minerals, and scattered sulfide mineral grains in a hydrothermal vein that cuts quartz monzonite and alaskite at the Free Enterprise mine, 2 miles west of Boulder, Mont. The Free Enterprise vein is one of many silicified reef-like structures in this area, most of which trend about N. 60° E. The cryptocrystalline silica zones of the area are lenticular and are bordered by an altered zone where quartz monzonite is the wall rock. No alteration was noticed where alaskite is adjacent to silica zones. No uranium minerals were observed at the surface, but radioactivity anomalies were noted at 57 outcrops. Underground mining has shown that leaching by downward percolating waters has removed most of the uranium from the near-surface part of the Free Enterprise vein and probably has enriched slightly, parts of the vein and the adjacent wall rock from the bottom of the leached zone to the ground-water level. It is possible that other veins that show low to moderate radioactivity at the surface may contain significant concentrations of uranium minerals at relatively shallow depth. The quartz monzonite appears to be a more favorable host rock for the cryptocrystalline silica and associated uranium minerals than the alaskite. The alaskite occurs as vertical_dikes plug-like masses, and as irregularly shaped, gently dipping masses that are believed to have been intruded into open fractures formed during the cooling of the quartz monzonite.

The discovery and character of Pleistocene calcrete uranium deposits in the Southern High Plains of west Texas, United States

USGS Publications Warehouse

Van Gosen, Bradley S.; Hall, Susan M.

2017-12-18

This report describes the discovery and geology of two near-surface uranium deposits within calcareous lacustrine strata of Pleistocene age in west Texas, United States. Calcrete uranium deposits have not been previously reported in the United States. The west Texas uranium deposits share characteristics with some calcrete uranium deposits in Western Australia—uranium-vanadium minerals hosted by nonpedogenic calcretes deposited in saline lacustrine environments.In the mid-1970s, Kerr-McGee Corporation conducted a regional uranium exploration program in the Southern High Plains province of the United States, which led to the discovery of two shallow uranium deposits (that were not publicly reported). With extensive drilling, Kerr-McGee delineated one deposit of about 2.1 million metric tons of ore with an average grade of 0.037 percent U3O8 and another deposit of about 0.93 million metric tons of ore averaging 0.047 percent U3O8.The west-Texas calcrete uranium-vanadium deposits occur in calcareous, fine-grained sediments interpreted to be deposited in saline lakes formed during dry interglacial periods of the Pleistocene. The lakes were associated with drainages upstream of a large Pleistocene lake. Age determinations of tephra in strata adjacent to one deposit indicate the host strata is middle Pleistocene in age.Examination of the uranium-vanadium mineralization by scanning-electron microscopy indicated at least two generations of uranium-vanadium deposition in the lacustrine strata identified as carnotite and a strontium-uranium-vanadium mineral. Preliminary uranium-series results indicate a two-component system in the host calcrete, with early lacustrine carbonate that was deposited (or recrystallized) about 190 kilo-annum, followed much later by carnotite-rich crusts and strontium-uranium-vanadium mineralization in the Holocene (about 5 kilo-annum). Differences in initial 234U/238U activity ratios indicate two separate, distinct fluid sources.

Dosimetric calculations for uranium miners for epidemiological studies.

PubMed

Marsh, J W; Blanchardon, E; Gregoratto, D; Hofmann, W; Karcher, K; Nosske, D; Tomásek, L

2012-05-01

Epidemiological studies on uranium miners are being carried out to quantify the risk of cancer based on organ dose calculations. Mathematical models have been applied to calculate the annual absorbed doses to regions of the lung, red bone marrow, liver, kidney and stomach for each individual miner arising from exposure to radon gas, radon progeny and long-lived radionuclides (LLR) present in the uranium ore dust and to external gamma radiation. The methodology and dosimetric models used to calculate these organ doses are described and the resulting doses for unit exposure to each source (radon gas, radon progeny and LLR) are presented. The results of dosimetric calculations for a typical German miner are also given. For this miner, the absorbed dose to the central regions of the lung is dominated by the dose arising from exposure to radon progeny, whereas the absorbed dose to the red bone marrow is dominated by the external gamma dose. The uncertainties in the absorbed dose to regions of the lung arising from unit exposure to radon progeny are also discussed. These dose estimates are being used in epidemiological studies of cancer in uranium miners.

Impact craters - Are they useful?

NASA Astrophysics Data System (ADS)

Masaitis, V. L.

1992-03-01

Terrestrial impact craters are important geological and geomorphological objects that are significant not only for scientific research but for industrial and commercial purposes. The structures may contain commercial minerals produced directly by thermodynamic transformation of target rocks (including primary forming ores) controlled by some morphological, structural or lithological factors and exposed in the crater. Iron and uranium ores, nonferrous metals, diamonds, coals, oil shales, hydrocarbons, mineral waters and other raw materials occur in impact craters. Impact morphostructures may be used for underground storage of gases or liquid waste material. Surface craters may serve as reservoirs for hydropower. These ring structures may be of value to society in other ways. Scientific investigation of them is especially important in comparative planetology, terrestrial geology and in other divisions of the natural sciences.

Geology and mineral deposits of the Carlile quadrangle, Crook County, Wyoming

USGS Publications Warehouse

Bergendahl, M.H.; Davis, R.E.; Izett, G.A.

1961-01-01

The Carlile quadrangle-is along the northwestern flank of the Black Hills uplift in Crook County, Wyo. The area-is primarily one of canyons and divides that are a result of downcutting by the Belle Fourche River and its tributaries through an alternating succession of sandstone, siltstone, and mudstone or shale beds. The present topography is also influenced by the regional structure, as reflected by the beds that dip gently westward and by the local structural features such as anticlines, domes, synclines, basins, and terraces, which are superimposed upon the regional setting. Rocks exposed include shale and thin limestone and sandstone beds belonging to the Redwater shale member of the Sundance formation and to the Morrison formation, both of Late Jurassic age; sandstone, siltstone, and mudstone of the Lakota and Fall River formations of Early Cretaceous age; and shale and sandstone of the Skull Creek shale, Newcastle sandstone, and Mowry shale, also of Early Cretaceous age. In the southwestern part of the quadrangle rocks of the Upper Cretaceous series are exposed. These include the Belle Fourche shale, Greenhorn formation, and Carlile shale. Gravel terraces, landslide debris, and stream alluvium comprise the surficial deposits. The Lakota and Fall River formations, which make up the Iriyan Kara group, contain uranium deposits locally in the northern Black Hills. These formations were informally subdivided in order to show clearly the vertical and lateral distribution of the sandstone, siltstone, and mudstone facies within them.The Lakota was subdivided into a sandstone unit and an overlying mudstone unit; the Fall River was subdivided, in ascending order, into a siltstone unit, a mudstone unit, a sandstone unit, and an upper unit. The lithologic character of the Lakota changes abruptly locally, and the units are quite inconsistent with respect to composition, thickness, and extent. This is in contrast to a notable consistency in the lithologic character and thickness among all the Fall River units, with the exception of the upper unit. Petrographic studies on selected samples of units from both formations show differences in composition between Lakota and Fall River rocks.The Carlile quadrangle lies immediately east of the monocline that marks the outer limit of the Black Hills uplift, and the rocks in this area have a regional dip of less than 2° outward from the center of the uplift. Superimposed upon the regional uplift are many subordinate structural features anticlines, synclines, domes, basins, and terraces which locally modify the regional features. The most pronounced of these subordinate structural features are the doubly-plunging Pine Ridge, Oil Butte, and Dakota Divide anticlines, and the Eggie Creek syncline. Stress throughout the area was relieved almost entirely through folding; only a few small nearly vertical normal faults were found within the quadrangle.Uranium has been mined from the Carlile deposit, owned by the Homestake Mining Co. The ore minerals, carnotite and tyuyamnuite occur in a sandstone lens that is enclosed within relatively impermeable clayey beds in the mudstone unit of the Lakota formation. The ore also includes unidentified black vanadium minerals and possibly coffinite. Uranium minerals are more abundant in and adjacent to thicker carbonaceous and silty seams in the sandstone lens. A mixture of fine-grained calcium carbonate and calcium sulfate fills the interstices between detrital quartz grains in mineralized sandstone. Selenium and arsenic are more abundant in samples that are high in uranium. Drilling on Thorn Divide about 1 mile west of the Carlile mine has roughly outlined concentrations of a sooty black uranium mineral associated with pyrite In two stratigraphic intervals of the Lakota formation. One is in the same sandstone lens that contains the ore at the Carlile mine; the other is in conglomeratic sandstone near the base of the Lakota. These deposits are relatively deep, and no mining has been attempted. The mineralogy of the Carlile deposits and the lithologic features of the sandstone host rock suggest that uranium and vanadium were transported in the high-valent state by carbonate or sulfate solutions, were extracted from solution by organic material, and were reduced to low-valent states to form an original assemblage of oxides and silicates. These primary minerals were oxidized in place, and the present carnotite-tyuyamunite assemblage was formed. In general, radioactivity analyses correspond fairly closely with chemical analyses of uranium, thus it is believed that only minor solution and migration of uranium has occurred since the present suite of oxidized minerals was formed. The factors responsible for ore localization are not clear, but probably a combination of three lithologic and structural elements contributed to provide a favorable environment for precipitating uranium from aqueous solutions: abundant carbonaceous material or pyrite in a thin, permeable sandstone enclosed within relatively thick impermeable clays; local structural basins; and a regional structural setting involving a broad syncline between two anticlines. The structural features controlled the regional flow of ground water and the lithologic features controlled the local rate of flow and provided the proper chemical environment for uranium deposition. Bentonite has been mined from an opencut in the Mowry shale in the southwest part of the quadrangle. A bentonite bed in the Newcastle sandstone also seems to be of minable thickness and quality. Exploration for petroleum has been unsuccessful within the quadrangle; however, some wells that yielded oil were recently drilled on small anticlines to the west and southeast. It is possible that similar structural features in the Carlile area, that were previously overlooked, may be equally productive.

The roles of organic matter in the formation of uranium deposits in sedimentary rocks

USGS Publications Warehouse

Spirakis, C.S.

1996-01-01

Because reduced uranium species have a much smaller solubility than oxidized uranium species and because of the strong association of organic matter (a powerful reductant) with many uranium ores, reduction has long been considered to be the precipitation mechanism for many types of uranium deposits. Organic matter may also be involved in the alterations in and around tabular uranium deposits, including dolomite precipitation, formation of silicified layers, iron-titanium oxide destruction, dissolution of quartz grains, and precipitation of clay minerals. The diagenetic processes that produced these alterations also consumed organic matter. Consequently, those tabular deposits that underwent the more advanced stages of diagenesis, including methanogenesis and organic acid generation, display the greatest range of alterations and contain the smallest amount of organic matter. Because of certain similarities between tabular uranium deposits and Precambrian unconformity-related deposits, some of the same processes might have been involved in the genesis of Precambrian unconformity-related deposits. Hydrologic studies place important constraints on genetic models of various types of uranium deposits. In roll-front deposits, oxidized waters carried uranium to reductants (organic matter and pyrite derived from sulfate reduction by organic matter). After these reductants were oxidized at any point in the host sandstone, uranium minerals were reoxidized and transported further down the flow path to react with additional reductants. In this manner, the uranium ore migrated through the sandstone at a rate slower than the mineralizing ground water. In the case of tabular uranium deposits, the recharge of surface water into the ground water during flooding of lakes carried soluble humic material to the water table or to an interface where humate precipitated in tabular layers. These humate layers then established the chemical conditions for mineralization and related alterations. In the case of Precambrian unconformity-related deposits, free thermal convection in the thick sandstones overlying the basement rocks carried uranium to concentrations of organic matter in the basement rocks.

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.

Spatial investigation of some uranium minerals using nuclear microprobe

NASA Astrophysics Data System (ADS)

Valter, Anton A.; Knight, Kim B.; Eremenko, Gelij K.; Magilin, Dmitry V.; Ponomarov, Artem A.; Pisansky, Anatoly I.; Romanenko, Alexander V.; Ponomarev, Alexander G.

2018-01-01

In this work, several individual grains of uranium minerals—uraninite with high content of Ca, Ca-rich boltwoodite, growths of uranophane with β-uranophane, and weeksite—from different uranium deposits were studied by a scanning nuclear microprobe. Particle-induced X-ray emission technique provided by the microprobe (µ-PIXE) was carried out to obtain a concentration and 2D distribution of elements in these minerals. In addition, energy dispersive X-ray spectrometry (SEM-EDS) provided by a scanning electron microscope was used. The types of minerals were determined by X-ray diffraction methods. Results of this study improved the understanding of trace elemental composition of the uranium minerals depending on their origin. Obtained signatures could be linked then to the sample provenance. Such data are important for nuclear forensics to identify the ore types and even specific ore bodies, when only small samples may be available for analysis. In this study, the µ-PIXE technique was used for obtaining the 2D distribution of trace elements that are not commonly measured by SEM-EDS at the relevant concentrations. The detected levels and precisions of elements determination by µ-PIXE were also defined. Using µ-PIXE, several micro mineral inclusions such as phosphate with high level of V and Si were identified. The age of the uranium minerals was estimated due to a significant content of radiogenic Pb that provides an additional parameter for determination of the main attributive characteristics of the minerals. This work also showed that due to its high elemental sensitivity the nuclear microprobe can be a new analytical tool for creating a nuclear forensic database from the known uranium deposits and a subsequent analysis of the intercepted illicit materials.

Spatial investigation of some uranium minerals using nuclear microprobe

NASA Astrophysics Data System (ADS)

Valter, Anton A.; Knight, Kim B.; Eremenko, Gelij K.; Magilin, Dmitry V.; Ponomarov, Artem A.; Pisansky, Anatoly I.; Romanenko, Alexander V.; Ponomarev, Alexander G.

2018-06-01

In this work, several individual grains of uranium minerals—uraninite with high content of Ca, Ca-rich boltwoodite, growths of uranophane with β-uranophane, and weeksite—from different uranium deposits were studied by a scanning nuclear microprobe. Particle-induced X-ray emission technique provided by the microprobe (µ-PIXE) was carried out to obtain a concentration and 2D distribution of elements in these minerals. In addition, energy dispersive X-ray spectrometry (SEM-EDS) provided by a scanning electron microscope was used. The types of minerals were determined by X-ray diffraction methods. Results of this study improved the understanding of trace elemental composition of the uranium minerals depending on their origin. Obtained signatures could be linked then to the sample provenance. Such data are important for nuclear forensics to identify the ore types and even specific ore bodies, when only small samples may be available for analysis. In this study, the µ-PIXE technique was used for obtaining the 2D distribution of trace elements that are not commonly measured by SEM-EDS at the relevant concentrations. The detected levels and precisions of elements determination by µ-PIXE were also defined. Using µ-PIXE, several micro mineral inclusions such as phosphate with high level of V and Si were identified. The age of the uranium minerals was estimated due to a significant content of radiogenic Pb that provides an additional parameter for determination of the main attributive characteristics of the minerals. This work also showed that due to its high elemental sensitivity the nuclear microprobe can be a new analytical tool for creating a nuclear forensic database from the known uranium deposits and a subsequent analysis of the intercepted illicit materials.

Carcinogenic and Cocarcinogenic Effects of Radon and Radon Daughters in Rats.

PubMed Central

Monchaux, G; Morlier, JP; Morin, M; Chameaud, J; Lafuma, J; Masse, R

1994-01-01

It has been previously established that lung cancer could be induced in rats by exposure to radon and radon daughters. Although the oat-cell carcinomas that are common in humans were not found in rats, other histological types of lung carcinomas, especially squamous cell carcinomas and primitive lung adenocarcinomas, were similar to those observed in humans. A dose-effect relationship was established for cumulative doses varying from 25 to 3000 working-level-months (WLM), which was similar for medium and high cumulative doses to that observed in uranium miners. This experimental protocol was also used to study the potential cocarcinogenic effects of other environmental or industrial airborne pollutants such as tobacco smoke, mineral fibers, diesel exhausts, or minerals from metallic mine ores that may act synergistically with radon exposure. In rats exposed to radon and tobacco smoke combined, the incidence of lung cancers was higher by a factor of 2-4 according to the cumulative radon exposure and the duration of tobacco smoke exposure. When mineral fibers were injected intrapleurally, an increased incidence of malignant thoracic tumors was observed in rats exposed to radon and fibers combined, but synergistic effects resulted in additivity. With diesel exhausts or minerals from metallic ores, a slight, nonsignificant increase in the incidence of lung carcinomas was observed compared with rats exposed to radon alone. These results demonstrated that it is possible to establish the potential cocarcinogenic action, showing either multiplicative, additive, or no effect of various environmental or industrial airborne pollutants combined with radon exposure. This radon model is valid for investigating possible interactions between two occupational exposures. Images p64-a Figure 1. Figure 2. Figure 3. Figure 4. Figure 5. Figure 6. PMID:9719670

Raoultella sp. SM1, a novel iron-reducing and uranium-precipitating strain.

PubMed

Sklodowska, Aleksandra; Mielnicki, Sebastian; Drewniak, Lukasz

2018-03-01

The main aim of this study was the characterisation of novel Raoutella isolate, an iron-reducing and uranium-precipitating strain, originating from microbial mats occurring in the sediments of a closed down uranium mine in Kowary (SW Poland). Characterisation was done in the context of its potential role in the functioning of these mats and the possibility to use them in uranium removal/recovery processes. In our experiment, we observed the biological precipitation of iron and uranium's secondary minerals containing oxygen, potassium, sodium and phosphor, which were identified as ningyoite-like minerals. The isolated strain, Raoultella sp. SM1, was also able to dissimilatory reduce iron (III) and uranium (VI) in the presence of citrate as an electron donor. Our studies allowed us to characterise a new strain which may be used as a model microorganism in the study of Fe and U respiratory processes and which may be useful in the bioremediation of uranium-contaminated waters and sediments. During this process, uranium may be immobilised in ningyoite-like minerals and can then be recovered in nano/micro-particle form, which may be easily transformed to uraninite. Copyright © 2017 Elsevier Ltd. All rights reserved.

Hydrogeochemical and stream sediment detailed geochemical survey for Edgemont, South Dakota; Wyoming

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

Butz, T.R.; Dean, N.E.; Bard, C.S.

1980-05-31

Results of the Edgemont detailed geochemical survey are reported. Field and laboratory data are presented for 109 groundwater and 419 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are given. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwaters containing greater than or equal to 7.35 ppB uranium are present in scattered clusters throughout the area sampled. Most of these groundwaters are from wells drilled where the Inyan Kara Group is exposed at themore » surface. The exceptions are a group of samples in the northwestern part of the area sampled and south of the Dewey Terrace. These groundwaters are also produced from the Inyan Kara Group where it is overlain by the Graneros Group and alluvium. The high uranium groundwaters along and to the south of the terrace are characterized by high molybdenum, uranium/specific conductance, and uranium/sulfate values. Many of the groundwaters sampled along the outcrop of the Inyan Kara Group are near uranium mines. Groundwaters have high amounts of uranium and molybdenum. Samples taken downdip are sulfide waters with low values of uranium and high values of arsenic, molybdenum, selenium, and vanadium. Stream sediments containing greater than or equal to 5.50 ppM soluble uranium are concentrated in basins draining the Graneros and Inyan Kara Groups. These values are associated with high values for arsenic, selenium, and vanadium in samples from both groups. Anomalous values for these elements in the Graneros Group may be caused by bentonite beds contained in the rock units. As shown on the geochemical distribution plot, high uranium values that are located in the Inyan Kara Group are almost exclusively draining open-pit uranium mines.« less

Indian Creek uranium prospects, Beaver County, Utah

USGS Publications Warehouse

Wyant, Donald G.; Stugard, Frederick

1951-01-01

The secondary uranium minerals metatorbernite (?) and autunite (?) were discovered at Indian Creek in the spring of 1950. The deposits, in sec. 26, T. 27 S., R. 6 T., Beaver County, Utah, are 20 miles west of Marysvale, and about three-eighths of a mile east of a quartz monzonite stock. The uranium minerals are sparsely disseminated in argillized and silicified earlier Tertiary Bullion Canyon latite and related volcanic rock beneart, but close to, the contact of the overlying later Tertiary Mount Belknap gray rhyolite. The prospects are in a landslide area where exposures are scarce. Therefore, trend and possible continuity of the altered and the uraniferous zones cannot be established definitely. The occurrence of secondary uranium minerals in beidellite-montmorillonite rock, formed by alteration of earlier Tertiary rocks near a quartz monzonite stock, is similar to that in some of the deposits in the Marysvale uranium district.

Effects of ammonium on uranium partitioning and kaolinite mineral dissolution.

PubMed

Emerson, Hilary P; Di Pietro, Silvina; Katsenovich, Yelena; Szecsody, Jim

2017-02-01

Ammonia gas injection is a promising technique for the remediation of uranium within the vadose zone. It can be used to manipulate the pH of a system and cause co-precipitation processes that are expected to remove uranium from the aqueous phase and decrease leaching from the solid phase. The work presented in this paper explores the effects of ammonium and sodium hydroxide on the partitioning of uranium and dissolution of the kaolinite mineral in simplified synthetic groundwaters using equilibrium batch sorption and sequential extraction experiments. It shows that there is a significant increase in uranium removal in systems with divalent cations present in the aqueous phase but not in sodium chloride synthetic groundwaters. Further, the initial conditions of the aqueous phase do not affect the dissolution of kaolinite. However, the type of base treatment does have an effect on mineral dissolution. Published by Elsevier Ltd.

28 CFR 79.42 - Criteria for eligibility for claims by miners.

Code of Federal Regulations, 2011 CFR

2011-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.42 Criteria for... in a uranium mine or mines during the period identified in paragraph (b) of this section; and (d) The...

28 CFR 79.42 - Criteria for eligibility for claims by miners.

Code of Federal Regulations, 2012 CFR

2012-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.42 Criteria for... in a uranium mine or mines during the period identified in paragraph (b) of this section; and (d) The...

28 CFR 79.42 - Criteria for eligibility for claims by miners.

Code of Federal Regulations, 2013 CFR

2013-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.42 Criteria for... in a uranium mine or mines during the period identified in paragraph (b) of this section; and (d) The...

28 CFR 79.42 - Criteria for eligibility for claims by miners.

Code of Federal Regulations, 2010 CFR

2010-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.42 Criteria for... in a uranium mine or mines during the period identified in paragraph (b) of this section; and (d) The...

Detection of depleted uranium in urine of veterans from the 1991 Gulf War.

PubMed

Gwiazda, R H; Squibb, K; McDiarmid, M; Smith, D

2004-01-01

American soldiers involved in "friendly fire" accidents during the 1991 Gulf War were injured with depleted-uranium-containing fragments or possibly exposed to depleted uranium via other routes such as inhalation, ingestion, and/or wound contamination. To evaluate the presence of depleted uranium in these soldiers eight years later, the uranium concentration and depleted uranium content of urine samples were determined by inductively coupled plasma mass spectrometry in (a) depleted uranium exposed soldiers with embedded shrapnel, (b) depleted uranium exposed soldiers with no shrapnel, and (c) a reference group of deployed soldiers not involved in the friendly fire incidents. Uranium isotopic ratios measured in many urine samples injected directly into the inductively coupled plasma mass spectrometer and analyzed at a mass resolution m/delta m of 300 appeared enriched in 235U with respect to natural abundance (0.72%) due to the presence of an interference of a polyatomic molecule of mass 234.81 amu that was resolved at a mass resolution m/delta m of 4,000. The 235U abundance measured on uranium separated from these urines by anion exchange chromatography was clearly natural or depleted. Urine uranium concentrations of soldiers with shrapnel were higher than those of the two other groups, and 16 out of 17 soldiers with shrapnel had detectable depleted uranium in their urine. In depleted uranium exposed soldiers with no shrapnel, depleted uranium was detected in urine samples of 10 out of 28 soldiers. The median uranium concentration of urines with depleted uranium from soldiers without shrapnel was significantly higher than in urines with no depleted uranium, though substantial overlap in urine uranium concentrations existed between the two groups. Accordingly, assessment of depleted uranium exposure using urine must rely on uranium isotopic analyses, since urine uranium concentration is not an unequivocal indicator of depleted uranium presence in soldiers with no embedded shrapnel.

Progress report on the Happy Jack mine, Which Canyon area, San Juan county, Utah

USGS Publications Warehouse

Trites, Albert F.; Chew, Randall T.

1954-01-01

The Happy Jack mine is in the White Canyon area, San Juan county, Utah. Production is from high-grade uranium deposits in the Shinarump conglomerate of the Triassic age. In this area the Shinarump beds range from about 16 to 40 feet in thickness and the lower part of these beds fills an east-trending channel this is note than 750 feet wide and 10 feet deep. The Shinarump conglomerate consists of beds of coarse- to fine-grained quartzose sandstone, conglomerate, siltstone, and claystone. Carbonized wood is abundant in these beds, and in the field it was classified as mineral charcoal and coal. Intra-Shinarump channels, cross-stratification, current lineation, and slumping and compaction structures have been recognized in the mine. Steeply dipping fractures have dominant trends in four directions -- N 65°W, N 60°E, N 85°E, and due north. Uranium occurs as bedded deposits, as replacement bodies in accumulations of "trash", and as replacements of larger fragments of wood. An "ore shoot" is formed where the three types of uranium deposits occur together; these ore shoots appear to be elongate masses with sharp boundaries. Uranium minerals include uraninite, sooty pitchblende(?), and the sulfate--betazippeite, johannite, and uranopilite. Associated with the uraninite are the sulfide minerals covellite, bornite, chalcopyritw, and pyrite. Galena and sphalerite have been found in close association with uranium minerals. The gaunge minerals include: limonite and hematite present in most of the sandstone beds throughout the deposit, jarosite that impregnates much of the sandstone in the outer parts of the mine workings, gypsum that fills many of the fractures, and barite that impregnates the sandstone in at least one part of the mine. Secondary copper minerals, mainly copper sulfates, occur throughout the mine, but most abundant near the adits in the outermost 30 feet of the workings. The minerals comprising the bulk of the country rock include quartz, feldspar, and clay minerals. The amount of uranium minerals deposited in a sandstone bed is believed to have been determined by the position of the bed in the channel, the permeability of the sandstone in the bed, and the amount of carbonized wood and plant remains within the bed. The beds considered most favorable for uranium deposition contain an abundance of claystone and siltstone both as matrix filling and as fragments and pebbles. Suggested exploration guides from uranium ore bodies include the following: (1) interbedded siltstone lenses, (2) claystone and siltstone cement and pabbles, (3) concentrations of "trash", (4) covelllite and bornite, (5) chalcopyrite, and (6) carbonized wood.

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. Copyright © 2013 Elsevier B.V. All rights reserved.

Uranium- and thorium-bearing pegmatites of the United States

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

Adams, J.W.; Arengi, J.T.; Parrish, I.S.

1980-04-01

This report is part of the National Uranium Resource Evaluation (NURE) Program designed to identify criteria favorable for the occurrence of the world's significant uranium deposits. This project deals specifically with uranium- and thorium-bearing pegmatites in the United States and, in particular, their distribution and origin. From an extensive literature survey and field examination of 44 pegmatite localities in the United States and Canada, the authors have compiled an index to about 300 uranium- and thorium-bearing pegmatites in the United States, maps giving location of these deposits, and an annotated bibliography to some of the most pertinent literature on themore » geology of pegmatites. Pegmatites form from late-state magma differentiates rich in volatile constituents with an attendant aqueous vapor phase. It is the presence of an aqueous phase which results in the development of the variable grain size which characterizes pegmatites. All pegmatites occur in areas of tectonic mobility involving crustal material usually along plate margins. Those pegmatites containing radioactive mineral species show, essentially, a similar distribution to those without radioactive minerals. Criteria such as tectonic setting, magma composition, host rock, and elemental indicators among others, all serve to help delineate areas more favorable for uranium- and thorium-bearing pegmatites. The most useful guide remains the radioactivity exhibited by uranium- and thorium-bearing pegmatites. Although pegmatites are frequently noted as favorable hosts for radioactive minerals, the general paucity and sporadic distribution of these minerals and inherent mining and milling difficulties negate the resource potential of pegmatites for uranium and thorium.« less

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

Preliminary report of the uranium favorability of shear zones in the crystalline rocks of the southern Appalachians

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

Penley, H.M.; Schot, E.H.; Sewell, J.M.

1978-11-01

Three sheared areas in the crystalline Piedmont and Blue Ridge provinces, from which uranium occurrences or anomalous radioactivity have been reported, were studied to determine their favorability for uranium mineralization. The study, which involved a literature review, geologic reconnaissance, ground radiometric surveys, and sampling of rock outcrops for petrographic and chemical analyses, indicates that more-detailed investigations of these and similar areas are warranted. In each area, surface leaching and deep residual cover make it difficult to assess the potential for uranium mineralization on the basis of results from chemical analyses for U/sub 3/O/sub 8/ and the radiometric surveys. Although anomalousmore » radioactivity and anomalous chemical uranium values were noted in only a few rock exposures and samples from the shear zones, the potential for uranium mineralization at depth could be much greater than indicated by these surface data. The study indicates that shear zones within Precambiran granitic basement complexes (such as the Wilson Creek Gneiss of western North Carolina, the Cranberry Gneiss of eastern Tennessee, and the Toxaway Gneiss of western South Carolina) are favorable as hosts for uranium and may contain subsurface deposits. Mylonitized graphitic schists immediately north of the Towaliga fault in Alabama and Georgia may be favorable host rocks for uranium.« less

Uranium in granites from the Southwestern United States: actinide parent-daughter systems, sites and mobilization. First year report

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

Silver, L T; Williams, I S; Woodhead, J A

1980-10-01

Some of the principal findings of the study on the Lawler Peak Granite are: the granite is dated precisely by this work at 1411 +- 3 m.y., confirming its synchroneity with a great regional terrane of granites. Uranium is presently 8-10 times crustal abundance and thorium 2-3 times in this granite. Uranium is found to be enriched in at least eight, possibly ten, primary igneous mineral species over the whole-rock values. Individual mineral species show distinct levels in, and characteristics ranges of, uranium concentration. It appears that in a uraniferous granite such as this, conventional accuracy mineral suites probably cannotmore » account for most of the uranium in the rock, and more rare, high U-concentration phases also are present and are significant uranium hosts. It appears that at least two different geological episodes have contributed to the disturbance of the U-Th-Pb isotope systems. Studies of various sites for transient dispersal of uranium, thorium, and radiogenic lead isotopes indicate a non-uniform dispersal of these components. It appears that the bulk rock has lost at least 24 percent of its original uranium endowment, accepting limited or no radiogenic lead or thorium migration from the sample.« less

Geology of the Midnite uranium mine, Stevens County, Washington; a preliminary report

USGS Publications Warehouse

Nash, J. Thomas; Lehrman, Norman J.

1975-01-01

The Midnite mine is one of only two mines in the United States currently producing uranium from discordant deposits in crystalline host rocks. Ore bodies are in metamorphosed steeply dipping Precambrian pelitic and calcareous rocks of a roof pendant adjacent to a Cretaceous(?) porphyritic quartz monzonite pluton. Production during 14 years, of operation has been about 8 million pounds of U3O8 from oxidized and reduced ores averaging 0.23 percent U3O8. Uranium deposits are generally tabular in form and dimensions range up to 380 m long, 210 m wide, and 50 m thick. Deposits are bounded on at least one side by unmineralized intrusive ribs of granitic rock, and thickest mineralized zones invariably occur at depressions in the intrusive contact. Upper limits of some deposits are nearly horizontal, and upper elevations of adjacent mineralized zones separated by ribs of granite are similar. Near surface ore is predominantly autunite, but ore at depth consists of pitchblende and coffinite with abundant pyrite and marcasite. Uranium minerals occur as .disseminations along foliation, replacements, and stockwork fracture-fillings. No stratigraphic controls on ore deposition are recognized. Rather, mineralized zones cut across lithologic boundaries if permeability is adequate. Most ore is in muscovite schist and mica phyllite, but important deposits occur in calc-silicate hornfels. Amphibolite sills and mid-Tertiary dacite dikes locally, carry ore where intensely fractured. High content of iron and sulfur, contained chiefly in FeS2, appear to be an important feature of favorable host rocks. Geometry of deposits, structural, and geochemical features suggest that uranium minerals were deposited over a span of time from late Cretaceous to late Tertiary. Ore occurs in but is not offset by a shear zone that displaces mid-Tertiary rocks.. Economic zones of uranium are interpreted to have been secondarily enriched in late Tertiary time by downward and lateral migration of uranium into permeable zones where deposition was influenced by ground water controls and minerals that could reduce or neutralize uranium-bearing solutions.

Sorption behavior of uranium(VI) on a biotite mineral

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

Idemitsu, K.; Obata, K.; Furuya, H.

1995-12-31

Biotite has the most important role for the sorption of radionuclides in granitic rocks. Experiments on the sorption of uranium(VI) on biotite were conducted to understand the fundamental controls on uranium sorption on biotite mineral, including the effects of pH and uranium concentration in solution. Biotite powder (mesh 32--60) were washed with 1N HCl for a week and were rinsed twice with deionized water for a week. This HCl treatment was necessary to avoid the effects by other minerals. The agreement between surface adsorption coefficient, Ka, of both biotites with and without HCl treatment was within one order of magnitude.more » The peak Ka value was in the range of 0.1 to 0.01 cm{sup 3}/cm{sup 2} around pH 6. A comparison of aqueous uranium speciations and sorption results indicates that neutral uranyl hydroxide could be an important species sorbed on the biotite. Sequential desorption experiments with KCl and HCl solutions were also carried out after sorption experiments to investigate sorption forms of uranium. Approximately 20% of uranium in solution were sorbed on the biotite as an exchangeable ion. The fraction of exchangeable uranium had a little dependence on pH. The other uranium could not be extracted even by 6N HCl solution. It is possible that most of the uranium could be precipitated as U(IV) via Fe(II) reduction on the biotite surface.« less

The importance of dissolved free oxygen during formation of sandstone-type uranium deposits

USGS Publications Warehouse

Granger, Harry Clifford; Warren, C.G.

1979-01-01

One factor which distinguishes t, he genesis of roll-type uranium deposits from the Uravan Mineral Belt and other sandstone-type uranium deposits may be the presence and concentration of dissolved free oxygen in the ore-forming. solutions. Although dissolved oxygen is a necessary prerequisite for the formation of roll-type deposits, it is proposed that a lack of dissolved oxygen is a prerequisite for the Uravan deposits. Solutions that formed both types of deposits probably had a supergene origin and originated as meteoric water in approximate equilibrium with atmospheric oxygen. Roll-type deposits were formed where the Eh dropped abruptly following consumption of the oxygen by iron sulfide minerals and creation of kinetically active sulfur species that could reduce uranium. The solutions that formed the Uravan deposits, on the other hand, probably first equilibrated with sulfide-free ferrous-ferric detrital minerals and fossil organic matter in the host rock. That is, the uraniferous solutions lost their oxygen without lowering their Eh enough to precipitate uranium. Without oxygen, they then. became incapable of oxidizing iron sulfide minerals. Subsequent localization and formation of ore bodies from these oxygen-depleted solutions, therefore, was not necessarily dependent on large reducing capacities.

Uranium XAFS analysis of kidney from rats exposed to uranium

PubMed Central

Kitahara, Keisuke; Numako, Chiya; Terada, Yasuko; Nitta, Kiyohumi; Homma-Takeda, Shino

2017-01-01

The kidney is the critical target of uranium exposure because uranium accumulates in the proximal tubules and causes tubular damage, but the chemical nature of uranium in kidney, such as its chemical status in the toxic target site, is poorly understood. Micro-X-ray absorption fine-structure (µXAFS) analysis was used to examine renal thin sections of rats exposed to uranyl acetate. The U L III-edge X-ray absorption near-edge structure spectra of bulk renal specimens obtained at various toxicological phases were similar to that of uranyl acetate: their edge position did not shift compared with that of uranyl acetate (17.175 keV) although the peak widths for some kidney specimens were slightly narrowed. µXAFS measurements of spots of concentrated uranium in the micro-regions of the proximal tubules showed that the edge jump slightly shifted to lower energy. The results suggest that most uranium accumulated in kidney was uranium (VI) but a portion might have been biotransformed in rats exposed to uranyl acetate. PMID:28244440

Uranium XAFS analysis of kidney from rats exposed to uranium.

PubMed

Kitahara, Keisuke; Numako, Chiya; Terada, Yasuko; Nitta, Kiyohumi; Shimada, Yoshiya; Homma-Takeda, Shino

2017-03-01

The kidney is the critical target of uranium exposure because uranium accumulates in the proximal tubules and causes tubular damage, but the chemical nature of uranium in kidney, such as its chemical status in the toxic target site, is poorly understood. Micro-X-ray absorption fine-structure (µXAFS) analysis was used to examine renal thin sections of rats exposed to uranyl acetate. The U L III -edge X-ray absorption near-edge structure spectra of bulk renal specimens obtained at various toxicological phases were similar to that of uranyl acetate: their edge position did not shift compared with that of uranyl acetate (17.175 keV) although the peak widths for some kidney specimens were slightly narrowed. µXAFS measurements of spots of concentrated uranium in the micro-regions of the proximal tubules showed that the edge jump slightly shifted to lower energy. The results suggest that most uranium accumulated in kidney was uranium (VI) but a portion might have been biotransformed in rats exposed to uranyl acetate.

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

Loomis, D.P.; Shy, C.M.; Allen, J.W.

The exfoliated-cell micronucleus (MN) assay was used to assess cytogenetic effects of exposure to radon progeny and cigarette smoke among 99 Colorado plateau uranium workers. Subjects were selected at random from employees in underground and open-pit uranium mines, ore mills, laboratories, and offices participating in a sputum screening program from 1964-88. The prevalence of cells with MN was determined by scoring one sputum specimen for each worker. Data obtained by interview were used to classify exposure to radon progeny and smoking at the time sputum specimens were taken. Underground miners were considered exposed to radon progeny, and others were consideredmore » unexposed. Neither radon progeny exposure nor cigarette smoking had any appreciable effect on the prevalence of cells with MN; crude prevalence ratios were 1.0 (95% CI 0.7-1.4) and 0.9 (95% CE 0.6-1.3), respectively. The effects of radon and smoking were not confounded by each other or by age, and there was no evidence of synergy between exposures. The findings appear to cast doubt on the epidemiological utility of a sputum-based MN assay for studies of other populations exposed to occupational or environmental lung carcinogens.« less

Detailed mineral and chemical relations in two uranium-vanadium ores

USGS Publications Warehouse

Garrels, Robert M.; Larsen, E. S.; 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 Virgin No. 3 mine, Montrose County, Colo., extends from weakly mineralized sandstone on both sides through a strongly mineralized central zone. The weakly mineralized zone is a poorly sorted sandstone with common detrital clay partings; chlorite and mixed layer mica-montmorrillonite are abundant interstitial to the quartz grains. No distinct vanadium or uranium minerals are recognizable, although the clay minerals are vanadium bearing. Euherdral pyrite grains and selenian galena are present but rare. The strongly mineralized rock is separated from the weakly mineralized rock by a narrow transition zone which only apporiximates the bedding planes. It contains abundant vanadium-bearing clay minerals (predominantly chlorite) interstitial to the quartz grains, and apparently replacing them. Paramontroseite is common and is intergrown with the clay minerals. Pyrite and marcasite are present, chiefly in or near the abundant blebs and fragments of carbonaceous material. Selenian galena is rarely present, and generally in or near carbonaceous material. Coffinite is the only uranium mineral idenitified; it is extremely fine grained and was identified only in X-ray diffraction patterns of heavy separates. Distribution of trace elements is not clear; some are consistently high in the strongly mineralized rocks, and some are consistently low. The trace element composition of the unmineralized rock is not known. Chemical studies show a very abrupt rise in the total U, V, and Fe from the weakly mineralized to strongly mineralized rock. Reducing-capacity studies indicate that most of the vanadium is present as V(IV), but some is present as V(V); that iron is present as both Fe(II) and Fe(III), the latter believed to have been present in the primary clays of the unmineralized rock; and that come of the uranium is present as U(VI) in addition to the U(IV) in the coffinite. All evidence points to weak oxidation of an ore once having a somewhat lower valence state. The channel samples from both the Mineral Joe No. 1 mine and the Virgin No. 3 mine are believe to have been essentially identical in mineralogy prior to oxidation by weathering: vanadium was present as V(III) in montroseite and V(IV) in the vanadium clays; uranium was present largely as U(IV) in coffinite and/or uraninite. The Mineral Joe No. 1 mine channel sample is now more fully oxidized. Vanadium clays are unquestionably formed abundantly during the primary mineralization, and they persist with a minimum of alteration during much of the weathering. They suggest that the vanadium is carried as V(IV) in the ore-forming fluids; it seems likely too that the uranium is carried as a U(VI) ion.

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.

Nanostructured Metal Oxide Sorbents for the Collection and Recovery of Uranium from Seawater

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

Chouyyok, Wilaiwan; Warner, Cynthia L.; Mackie, Katherine E.

2016-02-07

The ability to collect uranium from seawater offers the potential for a long-term green fuel supply for nuclear energy. However, extraction of uranium, and other trace minerals, is challenging due to the high ionic strength and low mineral concentrations in seawater. Herein we evaluate the use of nanostructured metal oxide sorbents for the collection and recovery of uranium from seawater. Chemical affinity, chemical adsorption capacity and kinetics of preferred sorbent materials were evaluated. High surface area manganese and iron oxide nanomaterials showed excellent performance for uranium collection from seawater. Inexpensive nontoxic carbonate solutions were demonstrated to be an effective andmore » environmental benign method of stripping the uranium from the metal oxide sorbents. Various formats for the utilization of the nanostructured metals oxide sorbent materials are discussed including traditional and nontraditional methods such as magnetic separation. Keywords: Uranium, nano, manganese, iron, sorbent, seawater, magnetic, separations, nuclear energy« less

Preliminary report on the Comet area, Jefferson County, Montana

USGS Publications Warehouse

Becraft, George Earle

1952-01-01

Several radioactivity anomalies and a few specimens of sooty pitchblende and other uranium minerals have been found on the mine dumps of formerly productive base-and precious-metal mines along the Comet-Gray Eagle shear zone in the Comet area in southwestern Montana. The shear zone is from 50 to 200 feet wide and has been traced for at least 5 1/2 miles. It trends N. 80° W. across the northern part of the area and cuts the quartz monzonitic rocks of the Boulder batholith and younger silicic intrusive rocks, as well as the pre-batholitic volcanic rocks, and is in turn cut by dacite and andesite dikes. The youngest period of mineralization is represented by chalcedonic vein zones comprising one or more discontinuous stringers and veins of cryptocrystalline silica in silicified quartz monzonite and in alaskite that has not been appreciably silicified. In some places these zones contain no distinct chalcedonic veins, but are represented only by silicified quartz monzonite. These zones locally contain uranium in association with very small amounts of the following minerals: pyrite, galena, ruby silver, argentite, native silver, molybdenite, chalcopyrite, arsenopyrite, and barite. At the Free Enterprise mine, uranium has been produced from a narrow chalcedonic vein that contains disseminated secondary uranium minerals and local small pods of pitchblende and from disseminated secondary uranium minerals in the adjacent quartz monzonite. Undiscovered commercial deposits of uranium ore may occur spatially associated with the base-and precious-metal deposits along the Comet-Gray Eagle shear zone, and chalcedonic vein zones similar to the Free Enterprise.

WEST NEEDLE WILDERNESS STUDY AREA, COLORADO.

USGS Publications Warehouse

Van Loenen, Richard E.; Scott, David C.

1984-01-01

The West Needle Wilderness Study Area, southwestern Colorado, was evaluated for mineral-resource potential. An area extending westward into the wilderness near the Elk Park mine, has a probable mineral-resource potential for uranium. Uranium resources, and associated silver, nickel, cobalt, and copper, are located at the Elk Park mine, directly adjacent to the eastern study area boundary. No potential for other mineral or energy resources was identified in this study.

Metallogenic evolution of uranium deposits in the Middle East and North Africa deposits

NASA Astrophysics Data System (ADS)

Howari, Fares; Goodell, Philip; Salman, Abdulaty

2016-02-01

This paper is briefly involved in classification and distributions of the Middle East and North Africa (MENA) uranium deposits. The study of these mineral systems can significantly contribute to our further understanding of the metallogeny of known and poorly explored deposits. This provides contribution to, and further enhancement of, current classifications and metallogenic models of uranium systems, allowing researchers to emphasize on unknown or poorly studied mineral systems found in MENA. The present study identified eight metallogenic types of uranium associated with: 1) the Archean rocks and intra-cratonic basins, 2) the Pan-African granites and rhyolites which are characterized by igneous activity, 3) Phanerozoic (Paleozoic) clastics, these deposits are the sedimentological response to Pan African magmatism, 4) Mesozoic (basal) clastics type e.g. Nubia sandstones which are characterized by uranium minerals, 5) regional sedimentary phosphate deposits which are categorized as geosynclinal, or continental margin deposits, on the shelf of the Tethys Ocean, 6) Cenozoic Intracratonic Felsic Magmatism of the Tibesti and Hoggar, and the sandstone U deposits of adjoining Niger. These are similar to the Pan-African magmatism metallogenic, 7) Calcretes, and 8) Resistate minerals which are often enriched in rare earth elements, sometimes including uranium. They are thus sometimes considered as U resources but poorly explored in the MENA region. These metallogenic types are described and discussed in the current paper.

Preliminary Report on the White Canyon Area, San Juan County, Utah

USGS Publications Warehouse

Benson, William Edward Barnes; Trites, A.F.; Beroni, E.P.; Feeger, J.A.

1952-01-01

The White Canyon area in San Juan County, Utah, contains known deposits of copper-uranium ore and is currently being mapped and studied by the Geological Survey. To date, approximately 75 square miles, or about 20 percent of the area, has been mapped on a scale 1 inch=1 mile. The White Canyon area is underlain by more than 2,000 feet of sedimentary rocks, Carboniferous to Jurassic(?) in age. The area is on the flank of the Elk Ridge anticline, and the strata have a regional dip of 1 deg to 2 deg SW. The Shinarump conglomerate of Late Triassic age is the principal ore-bearing formation. The Shinarump consists of lenticular beds of sandstone, conglomeratic sandstone, clay, and siltstone, and ranges in thickness from a feather edge to as much as 75 feet. Locally the sandstones contain silicified and carbonized wood and fragments of charcoal. These vegetal remains are especially common in channel-fill deposits. Jointing is prominent in the western part of the area, and apparently affects all formations. Adjacent to the joints some of the redbeds in the sequence are bleached. Deposits of copper-uranium minerals have been found in the Moenkopi, Shinarump, and Chinle formations, but the only production of ore has been from the Shinarump conglomerate. The largest concentration of these minerals is in the lower third of the Shinarump, and the deposits seem to be controlled in part by ancient channel fills and in part by fractures. Locally precipitation of the copper and uranium minerals apparently has been aided by charcoal and clays. Visible uranium minerals include both hard and soft pitchblende and secondary hydrosulfates, phosphates, and silicates. In addition, unidentified uranium compounds are present in carbonized wood and charcoal, and in veinlets of hydrocarbons. Base-metal sulfides have been identified in all prospects that extend beyond the oxidized zone. Secondary copper minerals in the oxidized zone include the hydrous sulfates and carbonates, and possibly chrysocolla. The principal gangue minerals are quartz, clay minerals, chlorite, oxides of iron and manganese, alunite, calcite, gypsum, pyrite, allophane, gibbsite, opal, and chalcedony. The origin of the copper-uranium ores has not been determined, but the association of many deposits with fractures, the mineralogic assemblage, and a lead-uranium age determination of 50 to 60 million years for the pitchblende in the Happy Jack mine favor the hypothesis that the ores are of hydrothermal origin and were deposited in early Tertiary time. Criteria believed to be the most useful in prospecting for new deposits are (1) visible uranium minerals; (2) visible copper minerals; (3) alunite; (4) hydrocarbons; and (5) bleaching of the underlying Moenkopi formation.

75 FR 48305 - Kaibab National Forest; Arizona; Uranium Exploratory Drilling Project

Federal Register 2010, 2011, 2012, 2013, 2014

2010-08-10

... DEPARTMENT OF AGRICULTURE Forest Service Kaibab National Forest; Arizona; Uranium Exploratory... a notice of intent to prepare an Environmental Impact Statement for the Uranium Exploratory Drilling... this notice may be mailed or hand-delivered to Kaibab National Forest, Attn: VANE Minerals Uranium...

National Uranium Resource Evaluation Program. Hydrogeochemical and stream sediment reconnaissance basic data for Beeville NTMS Quadrangle, Texas. Uranium resource evaluation project

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

Not Available

Results of a reconnaissance geochemical survey of the Beeville Quadrangle, Texas are reported. Field and laboratory data are presented for 373 groundwater and 364 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. The groundwater data indicate that the northwestern corner of the quadrangle is the most favorable for potential uranium mineralization. Favorability is indicated by high uranium concentrations; high arsenic, molybdenum, and vanadium concentrations;more » and proximity and similar geologic setting to the mines of the Karnes County mining district. Other areas that appear favorable are an area in Bee and Refugio Counties and the northeastern part of the quadrangle. Both areas have water chemistry similar to the Karnes County area, but the northeastern area does not have high concentrations of pathfinder elements. The stream sediment data indicate that the northeastern corner of the quadrangle is the most favorable for potential mineralization, but agricultural practices and mineralogy of the outcropping Beaumont Formation may indicate a false anomaly. The northwestern corner of the quadrangle is considered favorable because of its proximity to the known uranium deposits, but the data do not seem to support this.« less

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

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

Garralon, Antonio; Gomez, Paloma; Turrero, Maria Jesus

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. Themore » 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 uranium has a maximum value of 7.7 mg/L. According the analytical data of dissolved uranium, the mineral closest to equilibrium seems to be UO{sub 2}(am). The tritium contents in the groundwaters vary between 1.5 and 7.3 T.U. Considering that the mean value of tritium in rainwater from the studied area has a value of 4 T.U., it can be concluded that the residence times of the groundwaters are relatively short, not longer than 50 years in the oldest case. (authors)« less

Geology of the Midnite uranium mine area, Washington: maps, description, and interpretation

USGS Publications Warehouse

Nash, J. Thomas

1977-01-01

Bedrock geology of about 12 km2 near the Midnite mine has been mapped at the surface, in mine exposures, and from drilling, at scales from 1:600 to 1:12,000 and is presented here at 1:12,000 to provide description of the setting of uranium deposits. Oldest rocks in the area are metapelitic and metacarbonate rocks of the Precambrian (Y) Togo Formation. The chief host for uranium deposits is graphitic and pyritic mica phyllite and muscovite schist. Ore also occurs in calc-silicate hornfels and marble at the western edge of a calcareous section about 1,150 m thick. Calcareous rocks of the Togo are probably older than the pelitic as they are interpreted to be near the axis of a broad anticline. The composition and structural position of the calcareous unit suggests correlation with less metamorphosed carbonate-bearing rocks of the Lower Wallace Formation, Belt Supergroup, about 200 km to the east. Basic sills intrusive into the Togo have been metamorphosed to amphibolite. Unmetamorphosed rocks in the mine area are Cretaceous(?) and Eocene igneous rocks. Porphyritic quartz monzonite of Cretaceous age, part of the Loon Lake batholith, is exposed over one third of the mine area. It underlies the roof pendant of Precambrian rocks in which the Midnite mine occurs at depths of generally less than 300 m. The pluton is a two-mica granite and exhibits pegmatitic and aplitic textural features indicative of water saturation and pressure quenching. Eocene intrusive and extrusive rocks in the area provide evidence that the Eocene surface was only a short distance above the present uranium deposits. Speculative hypotheses are presented for penesyngenetic, hydrothermal, and supergene modes of uranium emplacement. The Precambrian Stratigraphy, similar in age and pre-metamorphic lithology to that of rocks hosting large uranium deposits in Saskatchewan and Northern Territory, Australia, suggests the possibility of uranium accumulation along with diagenetic pyrite in carbonaceous muds in a marine shelf environment. This hypothesis is not favored by the author because there is no evidence for stratabound uranium such as high regional radioactivity in the Togo. A hydrothermal mode of uranium emplacement is supported by the close apparent ages of mineralization and plutonism, and by petrology of the pluton. I speculate that uranium may have become enriched in postmagmatic fluids at the top of the pluton, possibly by hydrothermal leaching of soluble uranium associated with magnetite, and diffused outward into metasedimentary wall rocks to create an aureole about 100 m thick containing about 100 ppm uranium. Chemistry of the hydrothermal process is not understood, but uranium does not appear to have been transported by an oxidizing fluid, and the fluid did not produce veining and alteration comparable to that of base-metal sulfide deposits. Uranium in the low-grade protore is believed to have been redistributed into permeable zones in the Tertiary to create ore grades. Geologic and isotopic ages of uranium mineralization, and the small volume of porphyritic quartz monzonite available for leaching, are not supportive of supergene emplacement of uranium.

Extracellular reduction of uranium via Geobacter conductive pili as a protective cellular mechanism.

PubMed

Cologgi, Dena L; Lampa-Pastirk, Sanela; Speers, Allison M; Kelly, Shelly D; Reguera, Gemma

2011-09-13

The in situ stimulation of Fe(III) oxide reduction by Geobacter bacteria leads to the concomitant precipitation of hexavalent uranium [U(VI)] from groundwater. Despite its promise for the bioremediation of uranium contaminants, the biological mechanism behind this reaction remains elusive. Because Fe(III) oxide reduction requires the expression of Geobacter's conductive pili, we evaluated their contribution to uranium reduction in Geobacter sulfurreducens grown under pili-inducing or noninducing conditions. A pilin-deficient mutant and a genetically complemented strain with reduced outer membrane c-cytochrome content were used as controls. Pili expression significantly enhanced the rate and extent of uranium immobilization per cell and prevented periplasmic mineralization. As a result, pili expression also preserved the vital respiratory activities of the cell envelope and the cell's viability. Uranium preferentially precipitated along the pili and, to a lesser extent, on outer membrane redox-active foci. In contrast, the pilus-defective strains had different degrees of periplasmic mineralization matching well with their outer membrane c-cytochrome content. X-ray absorption spectroscopy analyses demonstrated the extracellular reduction of U(VI) by the pili to mononuclear tetravalent uranium U(IV) complexed by carbon-containing ligands, consistent with a biological reduction. In contrast, the U(IV) in the pilin-deficient mutant cells also required an additional phosphorous ligand, in agreement with the predominantly periplasmic mineralization of uranium observed in this strain. These findings demonstrate a previously unrecognized role for Geobacter conductive pili in the extracellular reduction of uranium, and highlight its essential function as a catalytic and protective cellular mechanism that is of interest for the bioremediation of uranium-contaminated groundwater.

Have we been wrong about ionizing radiation and chronic lymphocytic leukemia?

PubMed

Hamblin, Terry J

2008-04-01

It is almost axiomatic that chronic lymphocytic leukemia (CLL) is not caused by ionizing radiation. This assumption has been challenged recently by a critical re-appraisal of existing data. A recent paper implicated radon exposure in Czech uranium miners as a possible cause of CLL and in this issue of Leukemia Research the first paper examining the incidence of CLL among those exposed to radiation from the accident at the nuclear power plant in Chernobyl is published. It suggests that CLL occurring among the clean-up workers was of a more aggressive form than is normally seen in the community.

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

Spatial analysis techniques applied to uranium prospecting in Chihuahua State, Mexico

NASA Astrophysics Data System (ADS)

Hinojosa de la Garza, Octavio R.; Montero Cabrera, María Elena; Sanín, Luz H.; Reyes Cortés, Manuel; Martínez Meyer, Enrique

2014-07-01

To estimate the distribution of uranium minerals in Chihuahua, the advanced statistical model "Maximun Entropy Method" (MaxEnt) was applied. A distinguishing feature of this method is that it can fit more complex models in case of small datasets (x and y data), as is the location of uranium ores in the State of Chihuahua. For georeferencing uranium ores, a database from the United States Geological Survey and workgroup of experts in Mexico was used. The main contribution of this paper is the proposal of maximum entropy techniques to obtain the mineral's potential distribution. For this model were used 24 environmental layers like topography, gravimetry, climate (worldclim), soil properties and others that were useful to project the uranium's distribution across the study area. For the validation of the places predicted by the model, comparisons were done with other research of the Mexican Service of Geological Survey, with direct exploration of specific areas and by talks with former exploration workers of the enterprise "Uranio de Mexico". Results. New uranium areas predicted by the model were validated, finding some relationship between the model predictions and geological faults. Conclusions. Modeling by spatial analysis provides additional information to the energy and mineral resources sectors.

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

Band, P.; Feldstein, M.; Saccomanno, G.

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 probabilitymore » 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.« less

Uranium bioprecipitation mediated by yeasts utilizing organic phosphorus substrates.

PubMed

Liang, Xinjin; Csetenyi, Laszlo; Gadd, Geoffrey Michael

2016-06-01

In this research, we have demonstrated the ability of several yeast species to mediate U(VI) biomineralization through uranium phosphate biomineral formation when utilizing an organic source of phosphorus (glycerol 2-phosphate disodium salt hydrate (C3H7Na2O6P·xH2O (G2P)) or phytic acid sodium salt hydrate (C6H18O24P6·xNa(+)·yH2O (PyA))) in the presence of soluble UO2(NO3)2. The formation of meta-ankoleite (K2(UO2)2(PO4)2·6(H2O)), chernikovite ((H3O)2(UO2)2(PO4)2·6(H2O)), bassetite (Fe(++)(UO2)2(PO4)2·8(H2O)), and uramphite ((NH4)(UO2)(PO4)·3(H2O)) on cell surfaces was confirmed by X-ray diffraction in yeasts grown in a defined liquid medium amended with uranium and an organic phosphorus source, as well as in yeasts pre-grown in organic phosphorus-containing media and then subsequently exposed to UO2(NO3)2. The resulting minerals depended on the yeast species as well as physico-chemical conditions. The results obtained in this study demonstrate that phosphatase-mediated uranium biomineralization can occur in yeasts supplied with an organic phosphate substrate as sole source of phosphorus. Further understanding of yeast interactions with uranium may be relevant to development of potential treatment methods for uranium waste and utilization of organic phosphate sources and for prediction of microbial impacts on the fate of uranium in the environment.

Geochemistry of vanadium in an epigenetic, sandstone-hosted vanadium- uranium deposit, Henry Basin, Utah

USGS Publications Warehouse

Wanty, R.B.; Goldhaber, M.B.; Northrop, H.R.

1990-01-01

The epigenetic Tony M vanadium-uranium orebody in south-central Utah is hosted in fluvial sandstones of the Morrison Formation (Upper Jurassic). Measurements of the relative amounts of V+3 and V +4 in ore minerals show that V+3 is more abundant. Thermodynamic calculations show that vanadium was more likely transported to the site of mineralization as V+4. The ore formed as V+4 was reduced by hydrogen sulfide, followed by hydrolysis and precipitation of V+3 in oxide minerals or chlorite. Uranium was transported as uranyl ion (U+6), or some complex thereof, and reduced by hydrogen sulfide, forming coffinite. Detrital organic matter in the rocks served as the carbon source for sulfate-reducing bacteria. Vanadium most likely was derived from the dissolution of iron-titanium oxides. Uranium probably was derived from the overlying Brushy Basin Member of the Morrison Formation. Previous studies have shown that the ore formed at the density-stratified interface between a basinal brine and dilute meteoric water. The mineralization processes described above occurred within the mixing zone between these two fluids. -from Authors

Mineral and energy resources of the BLM Roswell Resource Area, east-central New Mexico

USGS Publications Warehouse

Bartsch-Winkler, Susan B.

1992-01-01

The sedimentary formations of the Roswell Resource Area have significant mineral and energy resources. Some of the pre-Pennsylvanian sequences in the Northwestern Shelf of the Permian Basin are oil and gas reservoirs, and Pennsylvanian rocks in Tucumcari basin are reservoirs of oil and gas as well as source rocks for oil and gas in Triassic rocks. Pre-Permian rocks also contain minor deposits of uranium and vanadium, limestone, and associated gases. Hydrocarbon reservoirs in Permian rocks include associated gases such as carbon dioxide, helium, and nitrogen. Permian rocks are mineralized adjacent to the Lincoln County porphyry belt, and include deposits of copper, uranium, manganese, iron, polymetallic veins, and Mississippi-valley-type (MVT) lead-zinc. Industrial minerals in Permian rocks include fluorite, barite, potash, halite, polyhalite, gypsum, anhydrite, sulfur, limestone, dolomite, brine deposits (iodine and bromine), aggregate (sand), and dimension stone. Doubly terminated quartz crystals, called "Pecos diamonds" and collected as mineral specimens, occur in Permian rocks along the Pecos River. Mesozoic sedimentary rocks are hosts for copper, uranium, and small quantities of gold-silver-tellurium veins, as well as significant deposits of oil and gas, COa, asphalt, coal, and dimension stone. Mesozoic rocks contain limited amounts of limestone, gypsum, petrified wood, dinosaur remains, and clays. Tertiary rocks host ore deposits commonly associated with intrusive rocks, including platinum group elements, iron skarns, manganese, uranium and vanadium, molybdenum, polymetallic vein deposits, gold-silver- tellurium veins, and thorium-rare earth veins. Museum-quality quartz crystals in Lincoln County were formed in association with intrusive rocks in the Lincoln County porphyry belt. Industrial minerals in Tertiary rocks include fluorite, vein- and bedded-barite, caliche, limestone, and aggregate. Tertiary and Quaternary sediments host important placer deposits of gold and titanium, and minor silver, uranium occurrences, as well as important industrial commodities, including caliche, limestone and dolomite, and aggregate (sand). Quaternary basalt contains sub-ore-grade uranium, scoria, and clay deposits.

Mineral and energy resources of the Roswell Resource Area, East-Central New Mexico

USGS Publications Warehouse

Bartsch-Winkler, Susan B.; Donatich, Alessandro J.

1995-01-01

The sedimentary formations of the Roswell Resource Area have significant mineral and energy resources. Some of the pre-Pennsylvanian sequences in the Northwestern Shelf of the Permian Basin are oil and gas reservoirs, and Pennsylvanian rocks in Tucumcari Basin are reservoirs of oil and gas as well as source rocks for oil and gas in Triassic rocks. Pre-Permian rocks also contain minor deposits of uranium and vanadium, limestone, and gases. Hydrocarbon reservoirs in Permian rocks include associated gases such as carbon dioxide, helium, and nitrogen. Permian rocks are mineralized adjacent to the Lincoln County porphyry belt, and include deposits of copper, uranium, manganese, iron, polymetallic veins, and Mississippi-Valley-type lead-zinc. Industrial minerals in Permian rocks include fluorite, barite, potash, halite, polyhalite, gypsum, anhydrite, sulfur, limestone, dolomite, brine deposits (iodine and bromine), aggregate (sand), and dimension stone. Doubly terminated quartz crystals, called 'Pecos diamonds' and collected as mineral specimens, occur in Permian rocks along the Pecos River. Mesozoic sedimentary rocks are hosts for copper, uranium, and small quantities of gold-silver-tellurium veins, as well as significant deposits of oil and gas, carbon dioxide, asphalt, coal, and dimension stone. Mesozoic rocks contain limited amounts of limestone, gypsum, petrified wood, and clay. Tertiary rocks host ore deposits commonly associated with intrusive rocks, including platinum-group elements, iron skarns, manganese, uranium and vanadium, molybdenum, polymetallic vein deposits, gold-silver-tellurium veins, and thorium-rare-earth veins. Museum-quality quartz crystals are associated with Tertiary intrusive rocks. Industrial minerals in Tertiary rocks include fluorite, vein- and bedded-barite, caliche, limestone, and aggregate. Tertiary and Quaternary sediments host important placer deposits of gold and titanium, and occurrences of silver and uranium. Important industrial commodities include caliche, limestone and dolomite, and aggregate. Quaternary basalt contains sub-ore-grade uranium, scoria, and clay deposits.

Preliminary report on the Comet area, Jefferson County, Montana

USGS Publications Warehouse

Becraft, George Earle

1953-01-01

Several radioactivity anomalies and a few specimens of sooty pitchblende and other uranium minerals have been found on the mine dumps of formerly productive base- and precious-metal mines along the Comet-Gray Eagle shear zone in the Comet area in southwestern Montana. The shear zone is from 50 to 200 feet wide and has been traced for at least 5? miles. It trends N. 80 ? W. across the northern part of the area and cuts the quartz monzonitic rocks of the Boulder batholith and younger silicic intrusive rocks, as well as prebatholithic volcanic rocks, and is in turn cut by dacite and andesite dikes. The youngest period of mineralization is represented by chalcedonic vein zones comprising one or more discontinuous stringers and veins of cryptocrystalline silica in silicified quartz monzonite and in alaskite that has not been appreciably silicified. In some places these zones contain no distinct chalcedonic veins but are represented only by silicified quartz monzonite. These zones locally contain uranium in association with very small amounts of pyrite, galena, ruby silver, arqentite, native silver, molybdenite, chalcopyrite, arsenopyrite, and barite. At the Free Enterprise mine, uranium has been produced from a narrow chalcedonic vein that contains disseminated secondary uranium minerals and local small pods of pitchblende and also from disseminated secondary uranium ,minerals in the adjacent quartz monzonite. Undiscovered deposits of uranium ore may occur spatially associated with the base- and precious-metal deposits along the Comet-Gray Eagle shear zone and with chalcedonic vein zones similar to the Free Enterprise.

Investigation of uranium binding forms in selected German mineral waters.

PubMed

Osman, Alfatih A A; Geipel, Gerhard; Bernhard, Gert; Worch, Eckhard

2013-12-01

Cryogenic time-resolved laser-induced fluorescence spectroscopy was successfully used to identify uranium binding forms in selected German mineral waters of extremely low uranium concentrations (<2.0 μg/L). The measurements were performed at a low temperature of 153 K. The spectroscopic data showed a prevalence of aquatic species Ca2UO2(CO3)3 in all investigated waters, while other uranyl-carbonate complexes, viz, UO2CO3(aq) and UO2(CO3)2 (2-), only existed as minor species. The pH value, alkalinity (CO3 (2-)), and the main water inorganic constituents, specifically the Ca(2+) concentration, showed a clear influence on uranium speciation. Speciation modeling was performed using the most recent thermodynamic data for aqueous complexes of uranium. The modeling results for the main uranium binding form in the investigated waters indicated a good agreement with the spectroscopy measurements.

Hydrogeochemical and stream sediment reconnaissance basic data for Palestine NTMS Quadrangle, Texas

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

Not Available

1979-05-04

Results of a reconnaissance geochemical survey of the Palestine Quadrangle are reported. Field and laboratory data are presented for 714 groundwater and 577 stream sediment samples. Statistical and areal distributions of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate that uranium concentrations above the 85th percentile occur primarily in the Caddell, Wellborn, and Manning Formations of the Jackson Group; and the Yegua Formation of the Claiborne Group. Saline watermore » trends are also prominent in these formations. Stream sediment data indicate that uranium values above the 85th percentile correlate with high concentrations of cerium, niobium, thorium, titanium, yttrium, and zirconium. This elemental suite probably indicates that uranium is associated with resistate and/or heavy minerals.« less

Preliminary report on the White Canyon area, San Juan county, Utah

USGS Publications Warehouse

Benson, William E.; Trites, Albert F.; Beroni, Ernest P.; Feeger, John A.

1952-01-01

The White Canyon area, in the central part of San Juan County, Utah, consists of approximately two 15-minute quadrangles. Approximately 75 square miles have been mapped by the Geological Survey on a scale of 1 inch equals 1 mile, using a combined aerial photography-plane table method. Structure contours were drawn on top of the Organ Rock member of the Cutler formation. Parts of the Gonway and North Point claims, 1/4 mile east of the Happy Jack mine, were mapped in detail. The principal objectives of the investigations were: (1) to establish ore guides; (2) to select areas favorable for exploration; and (3) to map the general geology and to determine the regional relationships of the uranium deposits. The White Canyon area is comprised of sedimentary rocks of Carboniferous to Jurassic age, more than 2,000 feet thick, having a regional dip of 1° to 2° SW. The nearest igneous rocks are in the Henry Mountains about 7 miles west of the northern part of the area; The Shinarump conglomerate of the late Triassic age, the principal ore horizon in the White Canyon area, consists of lenticular beds of sandstone, conglomeratic sandstone, conglomerate, clay, and siltstone. The Shinarump conglomerate, absent in places, is as much as 75 feet thick. The sandstones locally contain molds of logs and fragments of altered volcanic ash. Some of the logs have been replaced by copper and uranium minerals and iron oxides. The clay and siltstone underlie and are interbedded with the sandstone, and are most common in channels that cut into the underlying Moenkopi formation. The Shinarump conglomerate contains reworked Moenkopi siltstone fragments, clay balls, carbonized wood, and pebbles of quarts, quartzite, and chert. Jointing is prominent in the Western part of the mapped area. The three most prominent joint trends are due east, N. 65°-75° W., and N. 65°-75° E. All joints have vertical dips. The red beds are bleached along some joints, especially those that trend N. 65°-75° W. All uranium ore produced has been from the lower part of the Shinarump conglomerate, where it commonly occurs with copper as disseminations and fracture coatings in sandstone. Uranium and copper minerals also occur in low-grade disseminated deposits in the lower Chinle and in the Moenkopi formation and in veins cutting these formations. Although some uranium deposits occur in Chinarump channels and scours, copper and uranium minerals along fractures suggest that channel control may be secondary. Logs and clay balls apparently have exerted some chemical influences for deposition. The uranium occurs as the oxide in some deposits, and as secondary hydrous sulfates, phosphates, oxides, and silicates in these and several other deposits. Charcoal, iron and manganese oxides, and veinlets of hydrocarbon are abnormally radioactive in most of the deposits. Base-metal sulfides are commonly found inside the oxidized zone. Secondary copper minerals include the hydrous sulfates and carbonate. Gangue minerals include quarts, clay minerals, and manganese oxides, dickite (?), calcite, gypsum, pyrite, and chalcedony (?). Principal wall-rock alteration appears to have been silicification, clay alteration, and bleaching. Most of the shipped ore has contained more than 0.3 percent uranium. The ore also contains copper, commonly in grades lower than 1.0 percent. Criteria believed to be most useful for prospecting for concealed uranium deposits are (1) visible uranium minerals; (2) sulfide minerals; (3) secondary copper minerals; (4) dickite (?); (5) hydrocarbons; and (6) bleaching and alteration of the Moenkopi formation.

PROGRESS REPORT ON GEOLOGIC STUDIES OF THE RANGER OREBODIES, NORTHERN TERRITORY, AUSTRALIA.

USGS Publications Warehouse

Nash, J. Thomas; Frishman, David; ,

1985-01-01

The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes U//3O//8 in highly chloritized metasediments of the lower Proterozoic Cahill Formation within about 500 m of the projected sub-Kombolgie Formation unconformity. In both orebodies, oxidized and reduced uranium minerals occur chiefly in quartzose schists that have highly variable amounts of muscovite, sericite, and chlorite. The effects of several periods of alteration are pervasive in the vicinity of orebodies where biotite and garnet are altered to chlorite, and feldspars to white mica or chlorite. Oxidized uranium minerals, associated with earthy iron oxides, occur from the surface to a depth of about 60 m. Below the oxidized zone, uranium occurs chiefly as uraninite and pitchblende disseminated through thick sections of quartz-chlorite-muscovite schist and has no apparent association with graphite or sulphides. The geologic age(s) of uranium emplacement are obscure because there are few age criteria. Reduced uranium minerals are younger than 1. 8-b. y. -old granite dykes, and some occur locally in 1. 65-b. y. -old Kombolgie Formation.

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

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

Leng, Shuguang; Thomas, Cynthia L.; Snider, Amanda M.

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 usingmore » 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. Lastly, the associations are strongly supported by the functional relevance that the IL6 promoter SNP affects basal expression and carcinogen-induced IL-6 secretion« less

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

DOE PAGES

Leng, Shuguang; Thomas, Cynthia L.; Snider, Amanda M.; ...

2015-09-15

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 usingmore » 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. Lastly, the associations are strongly supported by the functional relevance that the IL6 promoter SNP affects basal expression and carcinogen-induced IL-6 secretion« less

Uranium content and leachable fraction of fluorspars

USGS Publications Warehouse

Landa, E.R.; Councell, T.B.

2000-01-01

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 ??g kg-1, with a mean of 2,145 ??g kg-1. As a point of comparison, the average concentration of uranium in the upper crust of the earth is about 2,500 ??g 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.

RIBE at an inter-organismic level: A study on genotoxic effects in Daphnia magna exposed to waterborne uranium and a uranium mine effluent.

PubMed

Reis, P; Lourenço, J; Carvalho, F P; Oliveira, J; Malta, M; Mendo, S; Pereira, R

2018-05-01

The induction of RIBE (Radiation Induced Bystander Effect) is a non-target effect of low radiation doses that has already been verified at an inter-organismic level in fish and small mammals. Although the theoretical impact in the field of environmental risk assessment (ERA) is possible, there is a gap of knowledge regarding this phenomenon in invertebrate groups and following environmentally relevant exposures. To understand if RIBE should be considered for ERA of radionuclide-rich wastewaters, we exposed Daphnia magna (<24 h and 5d old) to a 2% diluted uranium mine effluent for 48 h, and to a matching dose of waterborne uranium (55.3 μg L -1 ). Then the exposed organisms were placed (24 and 48 h) in a clean medium together with non-exposed neonates. The DNA damage observed for the non-exposed organisms was statistically significant after the 24 h cohabitation for both uranium (neonates p = 0.002; 5 d-old daphnids p = <0.001) and uranium mine effluent exposure (only for neonates p = 0.042). After 48 h cohabitation significant results were obtained only for uranium exposure (neonates p = 0.017; 5 d-old daphnids p = 0.013). Although there may be some variability associated to age and exposure duration, the significant DNA damage detected in non-exposed organisms clearly reveals the occurrence of RIBE in D. magna. The data obtained and here presented are a valuable contribution for the discussion about the relevance of RIBE for environmental risk assessment. Copyright © 2018 Elsevier B.V. All rights reserved.

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.

Chronic Exposure to Uranium from Gestation: Effects on Behavior and Neurogenesis in Adulthood

PubMed Central

Dinocourt, Céline; Culeux, Cécile; Legrand, Marie; Elie, Christelle; Lestaevel, Philippe

2017-01-01

Uranium exposure leads to cerebral dysfunction involving for instance biochemical, neurochemical and neurobehavioral effects. Most studies have focused on mechanisms in uranium-exposed adult animals. However, recent data on developing animals have shown that the developing brain is also sensitive to uranium. Models of uranium exposure during brain development highlight the need to improve our understanding of the effects of uranium. In a model in which uranium exposure began from the first day of gestation, we studied the neurobehavioral consequences as well as the progression of hippocampal neurogenesis in animals from dams exposed to uranium. Our results show that 2-month-old rats exposed to uranium from gestational day 1 displayed deficits in special memory and a prominent depressive-like phenotype. Cell proliferation was not disturbed in these animals, as shown by 5-bromo-2′deoxyuridine (BrdU)/neuronal specific nuclear protein (NeuN) immunostaining in the dentate gyrus. However, in some animals, the pyramidal cell layer was dispersed in the CA3 region. From our previous results with the same model, the hypothesis of alterations of neurogenesis at prior stages of development is worth considering, but is probably not the only one. Therefore, further investigations are needed to correlate cerebral dysfunction and its underlying mechanistic pathways. PMID:28513543

Chronic Exposure to Uranium from Gestation: Effects on Behavior and Neurogenesis in Adulthood.

PubMed

Dinocourt, Céline; Culeux, Cécile; Legrand, Marie; Elie, Christelle; Lestaevel, Philippe

2017-05-17

Uranium exposure leads to cerebral dysfunction involving for instance biochemical, neurochemical and neurobehavioral effects. Most studies have focused on mechanisms in uranium-exposed adult animals. However, recent data on developing animals have shown that the developing brain is also sensitive to uranium. Models of uranium exposure during brain development highlight the need to improve our understanding of the effects of uranium. In a model in which uranium exposure began from the first day of gestation, we studied the neurobehavioral consequences as well as the progression of hippocampal neurogenesis in animals from dams exposed to uranium. Our results show that 2-month-old rats exposed to uranium from gestational day 1 displayed deficits in special memory and a prominent depressive-like phenotype. Cell proliferation was not disturbed in these animals, as shown by 5-bromo-2'deoxyuridine (BrdU)/neuronal specific nuclear protein (NeuN) immunostaining in the dentate gyrus. However, in some animals, the pyramidal cell layer was dispersed in the CA3 region. From our previous results with the same model, the hypothesis of alterations of neurogenesis at prior stages of development is worth considering, but is probably not the only one. Therefore, further investigations are needed to correlate cerebral dysfunction and its underlying mechanistic pathways.

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

Chambers, Doug; Wiatzka, Gerd; Brown, Steve

This paper provides the life story of Canada's original radium/uranium mine. In addition to the history of operations, it discusses the unique and successful approach used to identify the key issues and concerns associated with the former radium, uranium and silver mining property and the activities undertaken to define the remedial actions and subsequent remedial plan. The Port Radium Mine site, situated approximately 275 km north of Yellowknife on the east shore of Great Bear Lake, Northwest Territories, was discovered in 1930 and underground mining began in 1932. The mine operated almost continuously from 1932 to 1982, initially for recoverymore » of radium, then uranium and finally, for recovery of silver. Tailings production totaled an estimated 900,000 tons and 800,000 tons from uranium and silver processing operations respectively. In the early days of mining, Port Radium miners were exposed to radon and associated decay product levels (in Working Level Months of exposure - WLM) hundreds of times greater than modern standards. The experience of the Port Radium miners provides important contribution to understanding the risks from radon. While the uranium mine was originally decommissioned in the early 1960's, to the standards of the day, the community of Deline (formerly Fort Franklin) had concerns about residual contamination at the mine site and the potential effects arising from use of traditional lands. The Deline people were also concerned about the possible risks to Deline Dene arising from their work as ore carriers. In the late 1990's, the community of Deline brought these concerns to national attention and consequently, the Government of Canada and the community of Deline agreed to move forward in a collaborative manner to address these concerns. The approach agreed to was to establish the Canada-Deline Uranium Table (CDUT) to provide a joint process by which the people of Deline could have their concerns expressed and addressed. A great deal of work was done through the CDUT, including efforts to assess site environment and safety issues in the context of modern reclamation standards. In addition to the environmental and remediation studies, an assessment of historic exposures of Deline ore carriers to radiation and a follow-up epidemiological feasibility study were performed. SENES Consultants Limited (SENES) carried out the dose reconstruction for the Port Radium miners in the 1990's, was the environmental consultant to the CDUT from 2000 to 2005, developed the Remedial Action Plan (RAP), engineering plans and specifications for decommissioning the Port Radium mine and vicinity sites in 2005/6, supervised the remedial works in 2007 and carried out the long term post closure monitoring from 2008 to 2012. Our firsthand experience from working cooperatively with the CDUT provides insights into effective decommissioning of historic contaminated sites. (authors)« less

The Toxicity of Depleted Uranium

PubMed Central

Briner, Wayne

2010-01-01

Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a clear and defined set of symptoms. Chronic low-dose, or subacute, exposure to depleted uranium alters the appearance of milestones in developing organisms. Adult animals that were exposed to depleted uranium during development display persistent alterations in behavior, even after cessation of depleted uranium exposure. Adult animals exposed to depleted uranium demonstrate altered behaviors and a variety of alterations to brain chemistry. Despite its reduced level of radioactivity evidence continues to accumulate that depleted uranium, if ingested, may pose a radiologic hazard. The current state of knowledge concerning DU is discussed. PMID:20195447

Mineral resources of the Fort Piute Wilderness Study Area, San Bernardino County, California

USGS Publications Warehouse

Nielson, Jane E.; Frisken, James G.; Jachens, Robert C.; McDonnell, John R.

1987-01-01

The Fort Piute Wilderness Study Area (CDCA-267) is in northeastern San Bernardino County, California, near the boundary between California and Nevada. Mineral surveys were requested for 31,371 acres of the Fort Piute Wilderness Study Area. In this report the area studied is referred to as "the study area". Examination of mines and prospects in the area was accomplished by the U.S. Bureau of Mines in 1981 and 1982. Field investigations of the area were carried out by the U.S. Geological Survey in 1983 and 1985. No mines or prospects, few mining claims, and no identified resources are located within the wilderness study area. Moderate and low potential for gold resources appears limited to outcrops of gneiss and granite exposed along the eastern side of the Piute Range. Available information indicates that there is no potential for energy resources, including oil and gas, uranium, or geothermal, in the study area.

Risk evaluation of uranium mining: A geochemical inverse modelling approach

NASA Astrophysics Data System (ADS)

Rillard, J.; Zuddas, P.; Scislewski, A.

2011-12-01

It is well known that uranium extraction operations can increase risks linked to radiation exposure. The toxicity of uranium and associated heavy metals is the main environmental concern regarding exploitation and processing of U-ore. In areas where U mining is planned, a careful assessment of toxic and radioactive element concentrations is recommended before the start of mining activities. A background evaluation of harmful elements is important in order to prevent and/or quantify future water contamination resulting from possible migration of toxic metals coming from ore and waste water interaction. Controlled leaching experiments were carried out to investigate processes of ore and waste (leached ore) degradation, using samples from the uranium exploitation site located in Caetité-Bahia, Brazil. In experiments in which the reaction of waste with water was tested, we found that the water had low pH and high levels of sulphates and aluminium. On the other hand, in experiments in which ore was tested, the water had a chemical composition comparable to natural water found in the region of Caetité. On the basis of our experiments, we suggest that waste resulting from sulphuric acid treatment can induce acidification and salinization of surface and ground water. For this reason proper storage of waste is imperative. As a tool to evaluate the risks, a geochemical inverse modelling approach was developed to estimate the water-mineral interaction involving the presence of toxic elements. We used a method earlier described by Scislewski and Zuddas 2010 (Geochim. Cosmochim. Acta 74, 6996-7007) in which the reactive surface area of mineral dissolution can be estimated. We found that the reactive surface area of rock parent minerals is not constant during time but varies according to several orders of magnitude in only two months of interaction. We propose that parent mineral heterogeneity and particularly, neogenic phase formation may explain the observed variation of the reactive mineral surface area. The formation of coatings on dissolving mineral surfaces significantly reduces the amount of surface available to react with fluids. Our results show that negatively charged ion complexes, responsible for U transport, decreases when alkalinity and rock buffer capacity is similarly lower. Carbonate ion pairs however, may increase U mobility when radionuclide concentration is high and rock buffer capacity is low. The present work helps to orient future monitoring of this site in Brazil as well as of other sites where uranium is linked to igneous rock formations, without the presence of sulphides. Monitoring SO4 migration (in acidic leaching uranium sites) seems to be an efficient and simple way to track different hazards, especially in tropical conditions, where the succession of dry and wet periods increases the weathering action of the residual H2SO4. Nevertheless, models of risk evaluation should take into account reactive surface areas and neogenic minerals since they determine the U ion complex formation, which in turn, controls uranium mobility in natural systems. Keywords: uranium mining, reactive mineral surface area, uranium complexes, inverse modelling approach, risk evaluation

Non-enzymatic U(VI) interactions with biogenic mackinawite

NASA Astrophysics Data System (ADS)

Veeramani, H.; Qafoku, N. P.; Kukkadapu, R. K.; Murayama, M.; Hochella, M. F.

2011-12-01

Reductive immobilization of hexavalent uranium [U(VI)] by stimulation of dissimilatory metal and/or sulfate reducing bacteria (DMRB or DSRB) has been extensively researched as a remediation strategy for subsurface U(VI) contamination. These bacteria derive energy by reducing oxidized metals as terminal electron acceptors, often utilizing organic substrates as electron donors. Thus, when evaluating the potential for in-situ uranium remediation in heterogeneous subsurface media, it is important to understand how the presence of alternative electron acceptors such as Fe(III) and sulfate affect U(VI) remediation and the long term behavior and reactivity of reduced uranium. Iron, an abundant subsurface element, represents a substantial sink for electrons from DMRB, and the reduction of Fe(III) leads to the formation of dissolved Fe(II) or to reactive biogenic Fe(II)- and mixed Fe(II)/Fe(III)- mineral phases. Consequently, abiotic U(VI) reduction by reactive forms of biogenic Fe(II) minerals could be a potentially important process for uranium immobilization. In our study, the DMRB Shewanella putrefaciens CN32 was used to synthesize a biogenic Fe(II)-bearing sulfide mineral: mackinawite, that has been characterized by XRD, SEM, HRTEM and Mössbauer spectroscopy. Batch experiments involving treated biogenic mackinawite and uranium (50:1 molar ratio) were carried out at room temperature under strict anoxic conditions. Following complete removal of uranium from solution, the biogenic mackinawite was analyzed by a suite of analytical techniques including XAS, HRTEM and Mössbauer spectroscopy to determine the speciation of uranium and investigate concomitant Fe(II)-phase transformation. Determining the speciation of uranium is critical to success of a remediation strategy. The present work elucidates non-enzymatic/abiotic molecular scale redox interactions between biogenic mackinawite and uranium.

Materials. Section 1 of Symposium on the peaceful uses of atomic energy in Australia, 1958, held in Sydney, in June 1958

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

None

The environments of the known uranium occurences in South Australia arc described, and the relation of uranium mineralization with sodic granitic rocks is emphasized. The problems in designing equipment for radiometric prospecting are reviewed. The fabrication and properties of BeO, UO/sub 2/, ThO/sub 2/, and mixed oxides are discussed. The use of pulsing in a uranium extraction pilot plant ion exchange column is described. The wetting of metals by liquid metals is reviewed with emphasis on liquid sodium. The geological nature, extent, and future prospects of minerals with atomic energy applications, occurring in New South Wales are outlined. The developmentmore » of a process for uranium recovery from Mary Kathleen ores is described. Techniques and processes involved in locating, mining, and concentrating davidite-type ores at Radium Hill, South Australia are described. The uranium deposits of the Northern Territory, Australia, are classified and described. The flotation behavior of the simple oxide minerals, uraninite and the colloform variety is discussed. The Port Pirie Treatment Plant for uranium recovery from refractory Radium Hill concentrates is described. The plant utilizes the sulfuric acid-ion exchange process. The uranium deposits of Queensland are described. the details of the production of uranium ore concentrates at Rum jungle near Darwin, Australia, are given. A brief account of the use of neutron diffraction analysis in crystallography is given, and the neutron spectrometers installed on the High Flux Australian Research Reactor are described. (T.R.H.)« less

Development of experimental approach to examine U occurrence continuity over the extended area reconnoitory boreholes: Lostoin Block, West Khasi Hills district, Meghalaya (India).

PubMed

Kukreti, B M; Kumar, Pramod; Sharma, G K

2015-10-01

Exploratory drilling was undertaken in the Lostoin block, West Khasi Hills district of Meghalaya based on the geological extension to the major uranium deposit in the basin. Gamma ray logging of drilled boreholes shows considerable subsurface mineralization in the block. However, environmental and exploration related challenges such as climatic, logistic, limited core drilling and poor core recovery etc. in the block severely restricted the study of uranium exploration related index parameters for the block with a high degree confidence. The present study examines these exploration related challenges and develops an integrated approach using representative sampling of reconnoitory boreholes in the block. Experimental findings validate a similar geochemically coherent nature of radio elements (K, Ra and Th) in the Lostoin block uranium hosting environment with respect to the known block of Mahadek basin and uranium enrichment is confirmed by the lower U to Th correlation index (0.268) of hosting environment. A mineralized zone investigation in the block shows parent (refers to the actual parent uranium concentration at a location and not a secondary concentration such as the daughter elements which produce the signal from a total gamma ray measurement) favoring uranium mineralization. The confidence parameters generated under the present study have implications for the assessment of the inferred category of uranium ore in the block and setting up a road map for the systematic exploration of large uranium potential occurring over extended areas in the basin amid prevailing environmental and exploratory impediments. Copyright © 2015 Elsevier Ltd. All rights reserved.

Cleaning of uranium vs machine coolant formulations

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

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 tomore » the alternate coolant does not appear to constitute a significant threat to the integrity of machined uranium parts.« less

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

Sahara Desert, Niger

NASA Image and Video Library

1996-01-20

STS072-709-063 (11-20 Jan. 1996) --- The astronauts aboard the Space Shuttle Endeavour exposed this 70mm frame of the Air Mountains, located in the country of Niger. These Sahara Desert structures are granitic intrusions. They are resistant to erosion and are very prominent in the lighter colored sands of the area. According to NASA geologists studying the photo collection, the ring-like structure on the lower left-hand edge of the photograph is probably a Quaternary volcanic feature. The highest peaks in the range approach 1,800 meters (6,000 feet). Deep valleys in the range are used by the Tuaregs for pasturage. Uranium and other minerals are being mined in the massif.

XAFS investigation of polyamidoxime-bound uranyl contests the paradigm from small molecule studies

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

Mayes, Richard T.; Piechowicz, Marek; Lin, Zekai

In this study, limited resource availability and population growth have motivated interest in harvesting valuable metals from unconventional reserves, but developing selective adsorbents for this task requires structural knowledge of metal binding environments. Amidoxime polymers have been identified as the most promising platform for large-scale extraction of uranium from seawater. However, despite more than 30 years of research, the uranyl coordination environment on these adsorbents has not been positively identified. We report the first XAFS investigation of polyamidoxime-bound uranyl, with EXAFS fits suggesting a cooperative chelating model, rather than the tridentate or η 2 motifs proposed by small molecule andmore » computational studies. Samples exposed to environmental seawater also display a feature consistent with a μ 2-oxo-bridged transition metal in the uranyl coordination sphere, suggesting in situ formation of a specific binding site or mineralization of uranium on the polymer surface. These unexpected findings challenge several long-held assumptions and have significant implications for development of polymer adsorbents with high selectivity.« less

XAFS investigation of polyamidoxime-bound uranyl contests the paradigm from small molecule studies

DOE PAGES

Mayes, Richard T.; Piechowicz, Marek; Lin, Zekai; ...

2015-11-12

In this study, limited resource availability and population growth have motivated interest in harvesting valuable metals from unconventional reserves, but developing selective adsorbents for this task requires structural knowledge of metal binding environments. Amidoxime polymers have been identified as the most promising platform for large-scale extraction of uranium from seawater. However, despite more than 30 years of research, the uranyl coordination environment on these adsorbents has not been positively identified. We report the first XAFS investigation of polyamidoxime-bound uranyl, with EXAFS fits suggesting a cooperative chelating model, rather than the tridentate or η 2 motifs proposed by small molecule andmore » computational studies. Samples exposed to environmental seawater also display a feature consistent with a μ 2-oxo-bridged transition metal in the uranyl coordination sphere, suggesting in situ formation of a specific binding site or mineralization of uranium on the polymer surface. These unexpected findings challenge several long-held assumptions and have significant implications for development of polymer adsorbents with high selectivity.« less

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

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

Li, L.; Steefel, C.I.; Williams, K.H.

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.more » 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.« less

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

PubMed

Li, Li; Steefel, Carl I; Williams, Kenneth H; Wilkins, Michael J; Hubbard, Susan S

2009-07-15

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 bean effective tool for quantitative estimation of mineral transformation and biomass accumulation, thus improving the design of bioremediation strategies.

Potential Aquifer Vulnerability in Regions Down-Gradient from Uranium In Situ Recovery (ISR) Sites

EPA Science Inventory

Sandstone-hosted roll-front uranium ore deposits originate when U(VI) dissolved in groundwater is reduced and precipitated as insoluble U(IV) minerals. Groundwater redox geochemistry, aqueous complexation, and solute migration are instrumental in leaching uranium from source rock...

The uranium deposit at the Yellow Canary claims, Daggett County, Utah

USGS Publications Warehouse

Wilmarth, V.R.; Vickers, R.C.; McKeown, F.A.; Beroni, E.P.

1952-01-01

The Yellow Canary claims uranium deposit is on the west side of Red Creek Canyon in the northern part of the Uinta Mountains, Daggett County, Utah. The claims have been developed by two adits, three open cuts, and several hundred deep of bulldozer trenches. No uranium ore has been produced from this deposit. The uranium deposit at the Yellow Canary claims is in the Red Creek quartzite of pre-Cambrian age. The formation is composed of intercalated beds of quartzite, hornblendite, garnet schist, staurolite schist, and quartz-mica schist and is intruded by diorite dikes. A thick unit of highly fractured white quatrzite at the top of the formation contains tyutamunite as coatings on fracture surfaces. The tyutamunite is associated with carnotite, volborthite, iron oxides, azurite, malachite, brochantite, and hyalite. The secondary uranium and vanadium minerals are believed to be alteration products of primary minerals. The uranium content of 15 samples from this property ranged from 0.000 to 0.57 percent.

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.

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.

Leukemia, lymphoma and multiple myeloma mortality (1950–1999) and incidence (1969–1999) in the Eldorado uranium workers cohort

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

Zablotska, Lydia B., E-mail: Lydia.Zablotska@ucsf.edu; Lane, Rachel S.D.; Frost, Stanley E.

Uranium workers are chronically exposed to low levels of radon decay products (RDP) and gamma (γ) radiation. Risks of leukemia from acute and high doses of γ-radiation are well-characterized, but risks from lower doses and dose-rates and from RDP exposures are controversial. Few studies have evaluated risks of other hematologic cancers in uranium workers. The purpose of this study was to analyze radiation-related risks of hematologic cancers in the cohort of Eldorado uranium miners and processors first employed in 1932–1980 in relation to cumulative RDP exposures and γ-ray doses. The average cumulative RDP exposure was 100.2 working level months andmore » the average cumulative whole-body γ-radiation dose was 52.2 millisievert. We identified 101 deaths and 160 cases of hematologic cancers in the cohort. Overall, male workers had lower mortality and cancer incidence rates for all outcomes compared with the general Canadian male population, a likely healthy worker effect. No statistically significant association between RDP exposure or γ-ray doses, or a combination of both, and mortality or incidence of any hematologic cancer was found. We observed consistent but non-statistically significant increases in risks of chronic lymphocytic leukemia (CLL) and Hodgkin lymphoma (HL) incidence and non-Hodgkin lymphoma (NHL) mortality with increasing γ-ray doses. These findings are consistent with recent studies of increased risks of CLL and NHL incidence after γ-radiation exposure. Further research is necessary to understand risks of other hematologic cancers from low-dose exposures to γ-radiation. - Highlights: • We analyzed long-term follow-up for hematologic cancers of the Eldorado uranium workers. • Workers were exposed to a unique combination of radon decay products (RDP) and gamma (γ) ray doses. • Exposures to RDP and γ-ray doses were not associated with significantly increased risks of cancers. • Radiation risks of chronic lymphocytic leukemia (CLL) and Hodgkin lymphoma were increased. • Study findings provide additional support for radiation-related risks of CLL.« less

Effect of nephrotoxic treatment with gentamicin on rats chronically exposed to uranium.

PubMed

Rouas, Caroline; Stefani, Johanna; Grison, Stéphane; Grandcolas, Line; Baudelin, Cédric; Dublineau, Isabelle; Pallardy, Marc; Gueguen, Yann

2011-01-11

Uranium is a radioactive heavy metal with a predominantly chemical toxicity, affecting especially the kidneys and more particularly the proximal tubular structure. Until now, few experimental studies have examined the effect of chronic low-dose exposure to uranium on kidney integrity: these mainly analyse standard markers such as creatinine and urea, and none has studied the effect of additional co-exposure to a nephrotoxic agent on rats chronically exposed to uranium. The aim of the present study is to examine the potential cumulative effect of treating uranium-exposed rats with a nephrotoxic drug. Neither physiological indicators (diuresis and creatinine clearance) nor standard plasma and urine markers (creatinine, urea and total protein) levels were deteriorated when uranium exposure was combined with gentamicin-induced nephrotoxicity. A histological study confirmed the preferential impact of gentamicin on the tubular structure and showed that uranium did not aggravate the histopathological renal lesions. Finally, the use of novel markers of kidney toxicity, such as KIM-1, osteopontin and kallikrein, provides new knowledge about the nephrotoxicity threshold of gentamicin, and allows us to conclude that under our experimental conditions, low dose uranium exposure did not induce signs of nephrotoxicity or enhance renal sensitivity to another nephrotoxicant. Copyright © 2010 Elsevier Ireland Ltd. All rights reserved.

Geologic report on the San Rafael Swell Drilling Project, San Rafael Swell, Utah

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

Bluhm, C.T.; Rundle, J.G.

1981-08-01

Twenty-two holes totaling 34,874 feet (10,629.6 meters) were rotary and core drilled on the northern and western flanks of the San Rafael Swell to test fluvial-lacustrine sequences of the Morrison Formation and the lower part of the Chinle Formation. The objective of the project was to obtain subsurface data so that improved uranium resource estimates could be determined for the area. Although the Brushy Basin and the Salt Wash Members of the Morrison Formation are not considered favorable in this area for the occurrence of significant uranium deposits, uranium minerals were encountered in several of the holes. Some spotty ormore » very low-grade mineralization was also encountered in the White Star Trunk area. The lower part of the Chinle Formation is considered to be favorable for potentially significant uranium deposits along the west flank of the San Rafael Swell. One hole (SR-202) east of Ferron, Utah, intersected uranium, silver, molybdenum, and copper mineralization. More exploratory drilling in the vicinity of this hole is recommended. As a result of the study of many geochemical analyses and a careful determination of the lithology shown by drilling, a sabkha environment is suggested for the concentration of uranium, zinc, iron, lead, copper, silver, and perhaps other elements in parts of the Moody Canyon Member of the Moenkopi Formation.« less

National Uranium Resource Evaluation: Aztec quadrangle, New Mexico and Colorado

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

Green, M.W.

1982-09-01

Areas and formations within the Aztec 1/sup 0/ x 2/sup 0/ Quadrangle, New Mexico and Colorado considered favorable for uranium endowment of specified minimum grade and tonnage include, in decreasing order of favorability: (1) the Early Cretaceous Burro Canyon Formation in the southeastern part of the Chama Basin; (2) the Tertiary Ojo Alamo Sandstone in the east-central part of the San Juan Basin; and (3) the Jurassic Westwater Canyon and Brushy Basin Members of the Morrison Formation in the southwestern part of the quadrangle. Favorability of the Burro Canyon is based on the presence of favorable host-rock facies, carbonaceous materialmore » and pyrite to act as a reductant for uranium, and the presence of mineralized ground in the subsurface of the Chama Basin. The Ojo Alamo Sandstone is considered favorable because of favorable host-rock facies, the presence of carbonaceous material and pyrite to act as a reductant for uranium, and the presence of a relatively large subsurface area in which low-grade mineralization has been encountered in exploration activity. The Morrison Formation, located within the San Juan Basin adjacent to the northern edge of the Grants mineral belt, is considered favorable because of mineralization in several drill holes at depths near 1500 m (5000 ft) and because of favorable facies relationships extending into the Aztec Quadrangle from the Grants mineral belt which lies in the adjacent Albuquerque and Gallup Quadrangles. Formations considered unfavorable for uranium deposits of specified tonnage and grade include the remainder of sedimentary and igneous formations ranging from Precambrian to Quaternary in age. Included under the unfavorable category are the Cutler Formation of Permian age, and Dakota Sandstone of Late Cretaceous age, and the Nacimiento and San Jose Formations of Tertiary age.« less

Immobilization of actinides in stable mineral type and ceramic materials (high temperature synthesis)

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

Starkov, O.; Konovalov, E.

1996-05-01

Alternative vitrification technologies are being developed in the world for the immobilization of high radioactive waste in materials with improved thermodynamic stability, as well as improved chemical and thermal stability and stability to radiation. Oxides, synthesized in the form of analogs to rock-forming minerals and ceramics, are among those materials that have highly stable properties and are compatible with the environment. In choosing the appropriate material, we need to be guided by its geometric stability, the minimal number of cations in the structure of the material and the presence of structural elements in the mineral that are isomorphs of uraniummore » and thorium, actinoids found in nature. Rare earth elements, yttrium, zirconium and calcium are therefore suitable. The minerals listed in the table (with the exception of the zircon) are pegatites by origin, i.e. they are formed towards the end of the magma crystallization of silicates form the residual melt, enriched with Ta, Nb, Ti, Zr, Ce, Y, U and Th. Uranium and thorium in the form of isomorphic admixtures form part of the lattice of the mineral. These minerals, which are rather simple in composition and structure and are formed under high temperatures, may be viewed as natural physio-chemical systems that are stable and long-lived in natural environments. The similarity of the properties of actinoids and lanthanoids plays an important role in the geochemistry of uranium and thorium; however, uranium (IV) is closer to the {open_quotes}heavy{close_quotes} group of lanthanoids (the yttrium group) while thorium (IV) is closer to the {open_quotes}light{close_quotes} group (the cerium group). That is why rare earth minerals contain uranium and thorium in the form of isomorphic admixtures.« less

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.

Cancer risk in nuclear workers occupationally exposed to uranium-emphasis on internal exposure.

PubMed

Canu, Irina Guseva; Ellis, Elizabeth Dupree; Tirmarche, Margot

2008-01-01

Workers involved in the nuclear fuel cycle have a potential for internal exposure to uranium. The present review of epidemiological studies of these workers aims to elucidate the relationship between occupational internal uranium exposure and cancer risk. Eighteen cohort and 5 nested case-control studies published since 1980 are reviewed. Workers occupationally exposed to uranium appear to be at increased risk of mortality from neoplasms of the lung, larynx, and lymphatic and haematopoietic tissue. Currently available evidence for a positive association between internal exposure to uranium and the risk of cancer is limited. The common weaknesses in reviewed studies include low statistical power and inaccurate assessment of internal exposure to uranium. Further investigations should focus on precise assessment of occupational exposure and address the issue of potential confounders.

Anomalous Lead Isotopic Composition of Galena and Age of Altered Uranium Minerals: a Case study of Chauli Deposits, Chatkal-Qurama District, Uzbekistan

NASA Astrophysics Data System (ADS)

Chernyshev, I. V.; Golubev, V. N.; Chugaev, A. V.

2017-11-01

The enrichment of lead isotopic composition of nonuranium minerals, in the first place galena in 206Pb and 207Pb, as compared to common lead is a remarkable feature of uranium deposits. The study of such lead isotopic composition anomalous in 206Pb and 207Pb in uranium minerals provides an opportunity for not only identification of superimposed processes resulting in transformation of uranium ores during deposit history but also calculation of age of these processes under certain model assumptions. Galena from the Chauli deposit in the Chatkal-Qurama district, Uzbekistan, a typical representative of hydrothermal uranium deposits associated with domains of Phanerozoic continental volcanism, has been examined with the highprecision (±0.02%) MC-ICP-MS method. Twenty microsamples of galena were taken from polished sections. Six of them are galena hosted in carbonate adjacent to pitchblende spherulites or filling thin veinlets (approximately 60 μm) cutting pitchblende. Isotopically anomalous lead with 206Pb/204Pb and 207Pb/204Pb values reaching 20.462 and 15.743, respectively, has been found in these six microsamples in contrast to another fourteen in which the Pb-Pb characteristics are consistent with common lead. On the basis of these data and with account for the 292 ± 2 Ma age for the Chauli deposit, the age of epigenetic transformation of uranium ores of this deposit has been estimated. During this process, radiogenic lead partly lost from pitchblende was captured into galena. The obtained date is 170 Ma. In the Chatkal-Qurama district, these epigenetic processes are apparently caused by the interaction of uranium minerals with activated underground water under tectonic activity and relief transformation, which took place from the post-Permian (i.e., after the Chauli formation) to the Jurassic period.

Separation of Depleted Uranium From Soil

DTIC Science & Technology

2009-03-01

order to remove the metallic DU present in these soils. This procedure would re- duce the amount of time that metallic uranium could undergo corrosion ...slow corrosion is not sufficient to ignite the uranium . Unfired rod Weathered, unfired rod with yellow uranyl salt deposits Figure 1. Comparison...resulting in less downward movement. Interactions between uranium corrosion products and soil mineral and organic components can also affect

Epithermal uranium deposits in a volcanogenic context: the example of Nopal 1 deposit, Sierra de Pena Blanca, Mexico

NASA Astrophysics Data System (ADS)

Calas, G.; Angiboust, S.; Fayek, M.; Camacho, A.; Allard, T.; Agrinier, P.

2009-12-01

The Peña Blanca molybdenum-uranium field (Chihuahua, Mexico) exhibits over 100 airborne anomalies hosted in tertiary ignimbritic ash-flow tuffs (44 Ma) overlying the Pozos conglomerate and a sequence of Cretaceous carbonate rocks. Uranium occurrences are associated with breccia zones at the intersection of two or more fault systems. Periodic reactivation of these structures associated with Basin and Range and Rio Grande tectonic events resulted in the mobilization of U and other elements by meteoric fluids heated by geothermal activity. Trace element geochemistry (U, Th, REE) provides evidence for local mobilization of uranium under oxidizing conditions. In addition, O- and H-isotope geochemistry of kaolinite, smectite, opal and calcite suggests that argillic alteration proceeded at shallow depth with meteoric water at 25-75 °C. Focussed along breccia zones, fluids precipitated several generations of pyrite and uraninite together with kaolinite, as in the Nopal 1 mine, indicating that mineralization and hydrothermal alteration of volcanic tuffs are contemporaneous. Low δ34S values (~ -24.5 ‰) of pyrites intimately associated with uraninite suggest that the reducing conditions at the origin of the U-mineralization arise from biological activity. Later, the uplift of Sierra Pena Blanca resulted in oxidation and remobilization of uranium, as confirmed by the spatial distribution of radiation-induced defect centers in kaolinites. These data show that tectonism and biogenic reducing conditions can play a major role in the formation and remobilization of uranium in epithermal deposits. By comparison with the other uranium deposits at Sierra Pena Blanca and nearby Sierra de Gomez, Nopal 1 deposit is one of the few deposits having retained a reduced uranium mineralization.

Background stratified Poisson regression analysis of cohort data.

PubMed

Richardson, David B; Langholz, Bryan

2012-03-01

Background stratified Poisson regression is an approach that has been used in the analysis of data derived from a variety of epidemiologically important studies of radiation-exposed populations, including uranium miners, nuclear industry workers, and atomic bomb survivors. We describe a novel approach to fit Poisson regression models that adjust for a set of covariates through background stratification while directly estimating the radiation-disease association of primary interest. The approach makes use of an expression for the Poisson likelihood that treats the coefficients for stratum-specific indicator variables as 'nuisance' variables and avoids the need to explicitly estimate the coefficients for these stratum-specific parameters. Log-linear models, as well as other general relative rate models, are accommodated. This approach is illustrated using data from the Life Span Study of Japanese atomic bomb survivors and data from a study of underground uranium miners. The point estimate and confidence interval obtained from this 'conditional' regression approach are identical to the values obtained using unconditional Poisson regression with model terms for each background stratum. Moreover, it is shown that the proposed approach allows estimation of background stratified Poisson regression models of non-standard form, such as models that parameterize latency effects, as well as regression models in which the number of strata is large, thereby overcoming the limitations of previously available statistical software for fitting background stratified Poisson regression models.

Enriched but not depleted uranium affects central nervous system in long-term exposed rat.

PubMed

Houpert, Pascale; Lestaevel, Philippe; Bussy, Cyrill; Paquet, François; Gourmelon, Patrick

2005-12-01

Uranium is well known to induce chemical toxicity in kidneys, but several other target organs, such as central nervous system, could be also affected. Thus in the present study, the effects on sleep-wake cycle and behavior were studied after chronic oral exposure to enriched or depleted uranium. Rats exposed to 4% enriched uranium for 1.5 months through drinking water, accumulated twice as much uranium in some key areas such as the hippocampus, hypothalamus and adrenals than did control rats. This accumulation was correlated with an increase of about 38% of the amount of paradoxical sleep, a reduction of their spatial working memory capacities and an increase in their anxiety. Exposure to depleted uranium for 1.5 months did not induce these effects, suggesting that the radiological activity induces the primary events of these effects of uranium.

The Itataia phosphate-uranium deposit (Ceará, Brazil) new petrographic, geochemistry and isotope studies

NASA Astrophysics Data System (ADS)

Veríssimo, César Ulisses Vieira; Santos, Roberto Ventura; Parente, Clóvis Vaz; Oliveira, Claudinei Gouveia de; Cavalcanti, José Adilson Dias; Nogueira Neto, José de Araújo

2016-10-01

The Itataia phosphate-uranium deposit is located in Santa Quitéria, in central Ceará State, northeastern Brazil. Mineralization has occurred in different stages and involves quartz leaching (episyenitization), brecciation and microcrystalline phase formation of concretionary apatite. The last constitutes the main mineral of Itatiaia uranium ore, namely collophane. Collophanite ore occurs in massive bodies, lenses, breccia zones, veins or episyenite in marble layers, calc-silicate rocks and gneisses of the Itataia Group. There are two accepted theories on the origin of the earliest mineralization phase of Itataia ore: syngenetic (primary) - where the ore is derived from a continental source and then deposited in marine and coastal environments; and epigenetic (secondary) - whereby the fluids are of magmatic, metamorphic and meteoric origin. The characterization of pre- or post-deformational mineralization is controversial, since the features of the ore are interpreted as deformation. This investigation conducted isotopic studies and chemical analyses of minerals in marbles and calc-silicate rocks of the Alcantil and Barrigas Formations (Itataia Group), as well as petrographic and structural studies. Analysis of the thin sections shows at least three phosphate mineral phases associated with uranium mineralizaton: (1) A prismatic fluorapatite phase associated with chess-board albite, arfvedsonite and ferro-eckermannite; (2) a second fluorapatite phase with fibrous radial or colloform habits that replaces calcium carbonate in marble, especially along fractures, with minerals such as quartz, chlorite and zeolite also identified in calc-silicate rocks; and (3) an younger phosphate phase of botryoidal apatite (fluorapatite and hydroxyapatite) related with clay minerals and probably others calcium and aluminum phosphates. Detailed isotopic analysis carried out perpendicularly to the mineralized levels and veins in the marble revealed significant variation in isotopic ratios. Mineralized zones exhibit a decrease in δ13C and δ18O isotope values and a higher 87Sr/86Sr ratio toward the center of the vein. In conjunction with petrographic studies, these changes contesting the hypothesis of a sedimentary origin for uranium and suggest a radiogenic Sr input by alkaline to peralkaline fluids from fertile granites of the end of Brasiliano/Pan-African orogeny, located outside the deposit. The origin of the phosphorous is associated with phosphorite deposits in the same depositional environment of the neoproterozoic supracrustal quartz-pelite-carbonate sediments of the Itataia Group. Considering the studies conducted here and available geological data, three main mineralizing events can be identified in Itataia: (1) an initial high temperature event connected with a sodium metasomatism-related uranium episode, taking place in Borborema Province and its African counterpart; (2) a second lower temperature stage, consisting of a multiphase cataclastic/hydrothermal event limited to fault and paleokarst zones; and (3) a third and final event, developed in frankly oxidizing conditions. The last two involving mixing of hydrothermal and meteoric fluids.

Mobilization of radionuclides from uranium mill tailings and related waste materials in anaerobic environments

USGS Publications Warehouse

Landa, E.R.

2003-01-01

Specific extraction studies in our laboratory have shown that iron and manganese oxide- and alkaline earth sulfate minerals are important hosts of radium in uranium mill tailings. Iron- and sulfate-reducing bacteria may enhance the release of radium (and its analog barium) from uranium mill tailings, oil field pipe scale [a major technologically enhanced naturally occurring radioactive material (TENORM) waste], and jarosite (a common mineral in sulfuric acid processed-tailings). These research findings are reviewed and discussed in the context of nuclear waste forms (such as barium sulfate matrices), radioactive waste management practices, and geochemical environments in the Earth's surficial and shallow subsurface regions.

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.

Evolution of uranium distribution and speciation in mill tailings, COMINAK Mine, Niger.

PubMed

Déjeant, Adrien; Galoisy, Laurence; Roy, Régis; Calas, Georges; Boekhout, Flora; Phrommavanh, Vannapha; Descostes, Michael

2016-03-01

This study investigated the evolution of uranium distribution and speciation in mill tailings from the COMINAK mine (Niger), in production since 1978. A multi-scale approach was used, which combined high resolution remote sensing imagery, ICP-MS bulk rock analyses, powder X-ray diffraction, Scanning Electron Microscopy, Focused Ion Beam--Transmission Electron Microscopy and X-ray Absorption Near Edge Spectroscopy. Mineralogical analyses showed that some ore minerals, including residual uraninite and coffinite, undergo alteration and dissolution during tailings storage. The migration of uranium and other contaminants depends on (i) the chemical stability of secondary phases and sorbed species (dissolution and desorption processes), and (ii) the mechanical transport of fine particles bearing these elements. Uranium is stabilized after formation of secondary uranyl sulfates and phosphates, and adsorbed complexes on mineral surfaces (e.g. clay minerals). In particular, the stock of insoluble uranyl phosphates increases with time, thus contributing to the long-term stabilization of uranium. At the surface, a sulfate-cemented duricrust is formed after evaporation of pore water. This duricrust limits water infiltration and dust aerial dispersion, though it is enriched in uranium and many other elements, because of pore water rising from underlying levels by capillary action. Satellite images provided a detailed description of the tailings pile over time and allow monitoring of the chronology of successive tailings deposits. Satellite images suggest that uranium anomalies that occur at deep levels in the pile are most likely former surface duricrusts that have been buried under more recent tailings. Copyright © 2015 Elsevier B.V. All rights reserved.

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 different investigators, including the varying absorption of samples of different thickness and concentration, or the variation attending slight changes in the chemical composition of the mineral. Some uranium minerals give poor diffraction patterns. The best results are generally obtained by using relatively small diameter spindles and long exposures, with a take-off angle from teh X-ray tube of about 4°. It is sometimes advantageous to shield the film from fluorescence in the visible region excited by X-ray irradiation. Copper radiation is preferable. The patterns of a few uranium minerals are greatly impaired by heavy grinding of the sample. Light crushing of the coarse sample after mixing with about one-third its volume of coarsely powdered low-absorption glass is helpful. Many uranium minerals, such as the members of the torbernite group, readily lose zeolithic water or transform to lower hydrates at or near ordinary conditions of temperature and humidity and care should be taken to control this in the manner of preservation and preparation of the sample.

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.

U-Pb dating of uranium deposits in collapse breccia pipes of the Grand Canyon region

USGS Publications Warehouse

Ludwig, K. R.; Simmons, K.R.

1992-01-01

Two major periods of uranium mineralization are indicated by U-Pb isotope dating of uranium ores from collapse breccia pipes in the Grand Canyon region, northern Arizona. The Hack 2 and 3, Kanab North, and EZ 1 and 2 orebodies apparently formed in the interval of 200 ?? 20 Ma, similar to ages inferred for strata-bound, Late Triassic-hosted uranium deposits in southern Utah and northern Arizona. Samples from the Grand Canyon and Pine Nut pipes, however, indicate a distinctly older age of about 260 Ma. The clustering in ages for a variety of uranium deposits at about the age of the lower part of the Chinle Formation (Late Triassic) suggests that uranium in these deposits may have been derived by leaching from volcanic ash in the Chinle and mobilized by ground-water movement. Pb isotope ratios of galenas in mineralized pipes are more radiogenic than those of sulfides from either uranium-poor pipes or occurrences away from pipes. Fluids which passed through the pipes had interacted with the Proterozoic basement, possibly through the vertical fractures which influenced the location and evolution of the pipes themselves. -from Authors

Radioactive rare-earth deposit at Scrub Oaks mine, Morris County, New Jersey

USGS Publications Warehouse

Klemic, Harry; Heyl, A.V.; Taylor, Audrey R.; Stone, Jerome

1959-01-01

A deposit of rare-earth minerals in the Scrub Oaks iron mine, Morris County, N. J., was mapped and sampled in 1955. The rare-earth minerals are mainly in coarse-grained magnetite ore and in pegmatite adjacent to it. Discrete bodies of rare-earth-bearing magnetite ore apparently follow the plunge of the main magnetite ore body at the north end of the mine. Radioactivity of the ore containing rare earths is about 0.2 to 0.6 mllliroentgens per hour. The principal minerals of the deposit are quartz, magnetite, hematite, albiteoligoclase, perthite and antiperthite. Xenotime and doverite aggregates and bastnaesite with intermixed leucoxene are the most abundant rare-earth minerals, and zircon, sphene, chevkinite, apatite, and monazite are of minor abundance in the ore. The rare-earth elements are partly differentiated into cerium-rich bastnaesite, chevkinite, and monazite, and yttrium-rich xenotime and doverite. Apatite, zircon, and sphene contain both cerium and yttrium group earths. Eleven samples of radioactive ore and rock average 0.009 percent uranium, 0.062 percent thorium, 1.51 percent combined rare-earth oxides including yttrium oxide and 24.8 percent iron. Scatter diagrams of sample data show a direct correlation between equivalent uranium, uranium, thorium, and combined rare^ earth oxides. Both cerium- and yttrium-group earths are abundant in the rare-earth minerals. Radioactive magnetite ore containing rare-earth minerals probably formed as a variant of the magnetite mineralization that produced the main iron ore of the Scrub Oaks deposit. The rare-earth minerals and the iron ore were deposited contemporaneously. Zircon crystals, probably deposited at the same time, have been determined by the Larsen method to be about 550 to 600 million years old (late Precambrian age). Uranium, thorium, and rare-earth elements are potential byproducts of iron in the coarse-grained magnetite ore.

Taxation and regulation of uranium mining in Canada

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

NONE

1990-11-01

Government taxation and regulation have a profound influence on mineral operations. In Canada, taxation occurs both on the federal and provincial levels. In addition, both federal and provincial regulations also affect mine operations, sometimes with overlapping, or conflicting, legislation and jurisdiction. Three broad areas of regulation affect the mine production of uranium in Canada: (1) mining law or mineral rights; (2) the licensing procedures; and (3) regulation of occupational health and safety.

Dynamic interplay between uranyl phosphate precipitation, sorption, and phase evolution

DOE PAGES

Munasinghe, P. Sumudu; Elwood Madden, Megan E.; Brooks, Scott C.; ...

2015-04-17

We report that natural examples demonstrate uranyl-phosphate minerals can maintain extremely low levels of aqueous uranium in groundwaters due to their low solubility. Thus, greater understanding of the geochemical factors leading to uranyl phosphate precipitation may lead to successful application of phosphate-based remediation methods. However, the solubility of uranyl phosphate phases varies over >3 orders of magnitude, with the most soluble phases typically observed in lab experiments. To understand the role of common soil/sediment mineral surfaces in the nucleation and transformation of uranyl phosphate minerals under environmentally relevant conditions, we carried out batch experiments with goethite and mica at pHmore » 6 in mixed electrolyte solutions ranging from 1–800 μM U and 1–800 μM P. All experiments ended with uranium concentrations below the USEPA MCL for U, but with 2–3 orders of magnitude difference in uranium concentrations.« less

OCCUPATIONAL EXPOSURE TO RADON IN DIFFERENT KINDS OF NON-URANIUM MINES.

PubMed

Fan, D; Zhuo, W; Zhang, Y

2016-09-01

For more accurate assessments of the occupational exposure to radon for miners, the individual monitoring was conducted by using an improved passive integrating (222)Rn monitor. A total of 120 miners in 3 different kinds of mines were monitored throughout a year. The results showed that the individual exposure to radon significantly varied with types of mines and work. Compared with the exposure to coal miners, the exposure to copper miners was much higher. Furthermore, it was found that the exposure might be overestimated if the environmental (222)Rn monitored by the passive integrating monitors was used for assessment. The results indicate that the individual monitoring of radon is necessary for an accurate assessment of radon exposure to miners, and radon exposure to non-uranium miners should also be assessed from the viewpoint of radiation protection. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Uranium hydrogeochemical and stream sediment reconnaissance of the Newcastle NTMS Quadrangle, Wyoming, including concentrations of forty-two additional elements

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

Goff, S.J.; Sandoval, W.F.; Gallimore, D.L.

1980-06-01

Water and sediment samples were collected and each water sample was analyzed for U, and each sediment sample was analyzed for 43 elements, including U and Th. Uranium concentrations in water samples range from below the detection limit of 0.02 ppB to 702.26 ppB and have a median of 1.73 ppB and a mean of 11.76 ppB. Water samples containing high uranium concentrations generally are associated with known uranium mining activity or units known to be uranium bearing. About one-third of the water samples containing high uranium concentrations were collected from locations within the Pumpkin Buttes and Turnercrest-Ross Districts. Nearlymore » half of the water samples containing high uranium concentrations were collected from locations just west of the Monument Hill and Highland Flats-Box Creek Districts. Similar anomalous uranium concentrations in this region have been reported updip from Exxon's Highland uranium deposits. High uranium concentrations were also found associated with the Lance Creek-Old Woman Anticline District. Uranium concentrations in sediment samples range from 1.14 to 220.70 ppM and have a median of 3.37 ppM and a mean of 4.03 ppM. Throughout the major uranium mining districts of the Powder River Basin, sediment samples with high uranium concentrations were collected from dry streams located near wells producing water samples with high uranium concentrations. High uranium concentrations were also found associated with the Lance Creek oil field where uranium mineralization is known in the White River formation. High uranium concentrations were also found in sediment samples in areas where uranium mineralization is not known. These samples are from dry streams in areas underlain by the White River formation, the Niobrara formation, and the Pierre, Carlisle, Belle Fourche, and Mowry shales.« less

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

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

Cristy, S.S.; Bennett, R.K. Jr.; Dillon, J.J.

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 themore » 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.« less

Determination of uranium in tap water by ICP-MS.

PubMed

El Himri, M; Pastor, A; de la Guardia, M

2000-05-01

A fast and accurate procedure has been developed for the determination of uranium at microg L(-1) level in tap and mineral water. The method is based on the direct introduction of samples, without any chemical pre-treatment, into an inductively coupled plasma mass spectrometer (ICP-MS). Uranium was determined at the mass number 238 using Rh as internal standard. The method provides a limit of detection of 2 ng L(-1) and a good repeatability with relative standard deviation values (RSD) about 3% for five independent analyses of samples containing 73 microg L(-1) of uranium. Recovery percentage values found for the determination of uranium in spiked natural samples varied between 91% and 106%. Results obtained are comparable with those found by radiochemical methods for natural samples and of the same order for the certified content of a reference material, thus indicating the accuracy of the ICP-MS procedure without the need of using isotope dilution. A series of mineral and tap waters from different parts of Spain and Morocco were analysed.

Origin of the Mariano Lake uranium deposit, McKinley County, New Mexico

USGS Publications Warehouse

Fishman, Neil S.; Reynolds, Richard L.

1982-01-01

The Mariano Lake uranium deposit, hosted by the Brushy Basin Member of the Jurassic Morrison Formation, occurs in the trough of an east-west trending syncline at the western end of the Smith Lake-Mariano Lake group of uranium deposits near Crownpoint, New Mexico. The orebody, which contains abundant amorphous organic material, is situated on the reduced side of a regional reduction-oxidation (redox) interface. The presence of amorphous organic material suggests the orebody may represent a tabular (primary) deposit, whereas the close proximity of the orebody to the redox interface is suggestive that uranium was secondarily redistributed by oxidative processes from pre-existing tabular orebodies. Uranium contents correlate positively with both organic carbon and vanadium contents. Petrographic evidence and scanning electron microscope-energy dispersive analyses point to uranium residence in the epigentically introduced amorphous organic material, which coats detrital grains and fills voids. Uranium mineralization was preceded by the following diagenetic alterations: precipitation of pyrite (d34S values ranging from-11.0 to-38.2 per mil); precipitation of mixed-layer smectite-illite clays; partial dissolution of some of the detrital feldspar population; and precipitation of quartz and adularia overgrowths. Alterations associated with uranium mineralization include emplacement of amorphous organic material (possibly uranium bearing); destruction of detrital iron-titanium oxide grains; coprecipitation of chlorite and microcrystalline quartz, and precipitation of pyrite and marcasite (d34S values for these sulfides ranging from -29.4 to -41.6 per mil). After mineralization, calcite, dolomite, barite, and kaolinite precipitated, and authigenic iron disulfides were replaced by ferric oxides and hydroxides. Geochemical data (primarily the positive correlation of uranium content to both organic carbon and vanadium contents) and petrographic observations (epigentically introduced amorphous organic matter and uranium residence in this organic matter) indicate that the Mariano Lake orebody is a tabular-type uranium deposit. Oxidative processes have not noticeably redistributed and reconcentrated primary uranium in the immediate vicinity of the deposit nor have they greatly modified geochemical characteristics in the ore. Preservation of the Mariano Lake deposit may not only be related to its position along the synclinal trough, where oxidative destruction of the orebody has been inhibited by stagnation of oxidizing ground waters by the structure, but also due to the deflection of ground waters (resulting from low orebody porosity) around the orebody.

Psychosocial and health impacts of uranium mining and milling on Navajo lands.

PubMed

Dawson, Susan E; Madsen, Gary E

2011-11-01

The uranium industry in the American Southwest has had profoundly negative impacts on American Indian communities. Navajo workers experienced significant health problems, including lung cancer and nonmalignant respiratory diseases, and psychosocial problems, such as depression and anxiety. There were four uranium processing mills and approximately 1,200 uranium mines on the Navajo Nation's over 27,000 square miles. In this paper, a chronology is presented of how uranium mining and milling impacted the lives of Navajo workers and their families. Local community leaders organized meetings across the reservation to inform workers and their families about the relationship between worker exposures and possible health problems. A reservation-wide effort resulted in activists working with political leaders and attorneys to write radiation compensation legislation, which was passed in 1990 as the Radiation Exposure Compensation Act (RECA) and included underground uranium miners, atomic downwinders, and nuclear test-site workers. Later efforts resulted in the inclusion of surface miners, ore truck haulers, and millworkers in the RECA Amendments of 2000. On the Navajo Nation, the Office of Navajo Uranium Workers was created to assist workers and their families to apply for RECA funds. Present issues concerning the Navajo and other uranium-impacted groups include those who worked in mining and milling after 1971 and are excluded from RECA. Perceptions about uranium health impacts have contributed recently to the Navajo people rejecting a resumption of uranium mining and milling on Navajo lands.

Control and distribution of uranium in coral reefs during diagenesis

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

Gvirtzman, G.; Friedman, G.M.; Miller, D.S.

1973-12-01

The concentration of about 2 ppM of uranium in the aragonitic skeletons of modern scleractinian corals which we studied is a constant value, regardless of occurrence, anatomy, or taxonomy. The presence of cement of aragonite or high- magnesian calcite usually raises the concentration of bulk samples to about 3 ppM. Modern corals may contain up to 50% of cementing minerals. Organisms, such as corals and coralline algae, while secreting their skeleton, discriminate against the uptake of uranium, whereas the uptake of uranium by mineral cements is less restrained. Aragonite cement contains about 3.6 ppM and highmagnesian calcite cement 2.6 ppMmore » uranium. During leaching by freshwater, the aragonite of the skeletons of corals dissolves out. This creates hollow molds which fill with drusy low-magnesian calcite. In emergent reefs from the shores of the Red Sea which display the ellects of progressive diagenesis this calcite is enriched in uranium (3.9 ppM) beyond that found in marine cements. Second-generation calcite, which fills original voids in the corals from the emergent reefs, contains a lower level of uranium concent ration (1.3 ppM). The level of concentration of uranium in low-magnesian calcite of diagenetically altered corals is a function of the availability of uranium in meteoric waters. In aragonite as well as in high- and low-magnesian calcite uranium replaces calcium or occupies lattice vacancies in the crystal lattice. (auth)« less

Fast formation of supergene Mn oxides/hydroxides under acidic conditions in the oxic/anoxic transition zone of a shallow aquifer.

PubMed

Schäffner, F; Merten, D; Pollok, K; Wagner, S; Knoblauch, S; Langenhorst, F; Büchel, G

2015-12-01

Extensive uranium mining in the former German Democratic Republic (GDR) in eastern Thuringia and Saxony took place during the period of 1946-1990. During mining activities, pelitic sediments rich in organic carbon and uranium were processed and exposed to oxygen. Subsequent pyrite oxidation and acidic leaching lead to partial contamination of the area with heavy metals and acid mine drainage (AMD) even few years after completion of remediation. One of those areas is the former heap Gessen (Ronneburg, Germany) were the residual contamination can be found 10 m under the base of the former heap containing partly permeable drainage channels. Actually, in such a system, a rapid but locally restricted mineralization of Mn oxides takes place under acidic conditions. This formation can be classified as a natural attenuation process as certain heavy metals, e.g., Cd (up to 6 μg/g), Ni (up to 311 μg/g), Co (up to 133 μg/g), and Zn (up to 104 μg/g) are bound to this phases. The secondary minerals occur as colored layers close to the shallow aquifer in glacial sediments and could be identified as birnessite and todorokite as Mn phase. The thermodynamic model shows that even small changes in the system are sufficient to shift either the pH or the Eh in the direction of stable Mn oxide phases in this acidic system. As a consequence of 9-15-year-long formation process (or even less), the supergene mineralization provides a cost-efficient contribution for remediation (natural attenuation) strategies of residual with heavy metals (e.g., Cd, Co, Ni, Zn) contaminated substrates.

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

WANG,YIFENG; XU,HUIFANG

Correctly identifying the possible alteration products and accurately predicting their occurrence in a repository-relevant environment are the key for the source-term calculation in a repository performance assessment. Uraninite in uranium deposits has long been used as a natural analog to spent fuel in a repository because of their chemical and structural similarity. In this paper, a SEM/AEM investigation has been conducted on a partially alternated uraninite sample from a uranium ore deposit of Shinkolobwe of Congo. The mineral formation sequences were identified: uraninite {yields} uranyl hydrates {yields} uranyl silicates {yields} Ca-uranyl silicates or uraninite {yields} uranyl silicates {yields} Ca-uranyl silicates.more » Reaction-path calculations were conducted for the oxidative dissolution of spent fuel in a representative Yucca Mountain groundwater. The predicted sequence is in general consistent with the SEM observations. The calculations also show that uranium carbonate minerals are unlikely to become major solubility-controlling mineral phases in a Yucca Mountain environment. Some discrepancies between model predictions and field observations are observed. Those discrepancies may result from poorly constrained thermodynamic data for uranyl silicate minerals.« less

Hydrologic and Temporal Influences of Evaporite Minerals on the Vertical Distribution, Storage, and Mobility of Uranium

NASA Astrophysics Data System (ADS)

Roycroft, S. J.; Noel, V.; Boye, K.; Besancon, C.; Weaver, K. L.; Johnson, R. H.; Dam, W. L.; Fendorf, S. E.; Bargar, J.

2016-12-01

Uranium contaminated groundwater in Riverton, Wyoming persists despite anticipated natural attenuation outside of a former uranium ore processing facility. The inability of natural flushing to dilute the uranium below the regulatory threshold indicates that sediments act as secondary sources likely (re)supplying uranium to groundwater. Throughout the contaminated floodplain, uranium rich-evaporites are readily abundant in the upper 2 m of sediments and are spatially coincident with the location of the plume, which suggests a likely link between evaporites and increased uranium levels. Knowledge of where and how uranium is stored within evaporite-associated sediments is required to understand processes controlling the mobility of uranium. We expect that flooding and seasonal changes in hydrologic conditions will affect U phase partitioning, and thus largely control U mobility. The primary questions we are addressing in this project are: What is the relative abundance of uranium incorporated in various mineral complexes throughout the evaporite sediments? How do the factors of depth, location, and seasonality influence the relative incorporation, mobility and speciation of uranium?We have systematically sampled from two soil columns over three dates in Riverton. The sampling dates span before and after a significant flooding event, providing insight into the flood's impact on local uranium mobility. Sequential chemical extractions are used to decipher the reactivity of uranium and approximate U operationally defined within reactants targeting carbonate, silicate, organic, and metal oxide bound or water and exchangeable phases. Extractions throughout the entirety of the sediment cores provide a high-resolution vertical profile of the distribution of uranium in various extracted phases. Throughout the profile, the majority (50-60%) of uranium is bound within carbonate-targeted extracts, a direct effect of the carbonate-rich evaporite sediments. The sum of our analyses provide a dynamic model of uranium incorporation within evaporite sediments holding implications for the fate of uranium throughout contaminated sites across the Colorado River Basin.

Uranium in Surface Waters and Sediments Affected by Historical Mining in the Denver West 1:100,000 Quadrangle, Colorado

USGS Publications Warehouse

Zielinski, Robert A.; Otton, James K.; Schumann, R. Randall; Wirt, Laurie

2008-01-01

Geochemical sampling of 82 stream waters and 87 stream sediments within mountainous areas immediately west of Denver, Colorado, was conducted by the U.S. Geological Survey in October 1994. The primary purpose was to evaluate regionally the effects of geology and past mining on the concentration and distribution of uranium. The study area contains uranium- and thorium-rich bedrock, numerous noneconomic occurrences of uranium minerals, and several uranium deposits of variable size and production history. During the sampling period, local streams had low discharge and were more susceptible to uranium-bearing acid drainage originating from historical mines of base- and precious-metal sulfides. Results indicated that the spatial distribution of Precambrian granites and metamorphic rocks strongly influences the concentration of uranium in stream sediments. Within-stream transport increases the dispersion of uranium- and thorium rich mineral grains derived primarily from granitic source rocks. Dissolved uranium occurs predominantly as uranyl carbonate complexes, and concentrations ranged from less than 1 to 65 micrograms per liter. Most values were less than 5 micrograms per liter, which is less than the current drinking water standard of 30 micrograms per liter and much less than locally applied aquatic-life toxicity standards of several hundred micrograms per liter. In local streams that are affected by uranium-bearing acid mine drainage, dissolved uranium is moderated by dilution and sorptive uptake by stream sediments. Sorbents include mineral alteration products and chemical precipitates of iron- and aluminum-oxyhydroxides, which form where acid drainage enters streams and is neutralized. Suspended uranium is relatively abundant in some stream segments affected by nearby acid drainage, which likely represents mobilization of these chemical precipitates. The 234U/238U activity ratio of acid drainage (0.95-1.0) is distinct from that of local surface waters (more than 1.05), and this distinctive isotopic composition may be preserved in iron-oxyhydroxide precipitates of acid drainage origin. The study area includes a particularly large vein-type uranium deposit (Schwartzwalder mine) with past uranium production. Stream water and sediment collected downstream from the mine's surface operations have locally anomalous concentrations of uranium. Fine-grained sediments downstream from the mine contain rare minute particles (10-20 micrometers) of uraninite, which is unstable in a stream environment and thus probably of recent origin related to mining. Additional rare particles of very fine grained (less than 5 micrometer) barite likely entered the stream as discharge from settling ponds in which barite precipitation was formerly used to scavenge dissolved radium from mine effluent.

28 CFR 79.44 - Proof of working level month exposure to radiation.

Code of Federal Regulations, 2013 CFR

2013-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.44 Proof of...; (2) Certified copies of records of the owner or operator of a uranium mine in the specified states... employment in a uranium mine that a claimant establishes under § 79.43(c) as to which paragraph (d) of this...

28 CFR 79.44 - Proof of working level month exposure to radiation.

Code of Federal Regulations, 2012 CFR

2012-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.44 Proof of...; (2) Certified copies of records of the owner or operator of a uranium mine in the specified states... employment in a uranium mine that a claimant establishes under § 79.43(c) as to which paragraph (d) of this...

28 CFR 79.44 - Proof of working level month exposure to radiation.

Code of Federal Regulations, 2011 CFR

2011-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.44 Proof of...; (2) Certified copies of records of the owner or operator of a uranium mine in the specified states... employment in a uranium mine that a claimant establishes under § 79.43(c) as to which paragraph (d) of this...

28 CFR 79.44 - Proof of working level month exposure to radiation.

Code of Federal Regulations, 2010 CFR

2010-07-01

... RADIATION EXPOSURE COMPENSATION ACT Eligibility Criteria for Claims by Uranium Miners § 79.44 Proof of...; (2) Certified copies of records of the owner or operator of a uranium mine in the specified states... employment in a uranium mine that a claimant establishes under § 79.43(c) as to which paragraph (d) of this...

Risk of Lung Cancer Mortality in Nuclear Workers from Internal Exposure to Alpha Particle-emitting Radionuclides

PubMed Central

Atkinson, Will; Bérard, Philippe; Bingham, Derek; Birchall, Alan; Blanchardon, Eric; Bull, Richard; Guseva Canu, Irina; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Do, Minh T.; Engels, Hilde; Figuerola, Jordi; Foster, Adrian; Holmstock, Luc; Hurtgen, Christian; Laurier, Dominique; Puncher, Matthew; Riddell, Anthony E.; Samson, Eric; Thierry-Chef, Isabelle; Tirmarche, Margot; Vrijheid, Martine; Cardis, Elisabeth

2017-01-01

Background: Carcinogenic risks of internal exposures to alpha-emitters (except radon) are poorly understood. Since exposure to alpha particles—particularly through inhalation—occurs in a range of settings, understanding consequent risks is a public health priority. We aimed to quantify dose–response relationships between lung dose from alpha-emitters and lung cancer in nuclear workers. Methods: We conducted a case–control study, nested within Belgian, French, and UK cohorts of uranium and plutonium workers. Cases were workers who died from lung cancer; one to three controls were matched to each. Lung doses from alpha-emitters were assessed using bioassay data. We estimated excess odds ratio (OR) of lung cancer per gray (Gy) of lung dose. Results: The study comprised 553 cases and 1,333 controls. Median positive total alpha lung dose was 2.42 mGy (mean: 8.13 mGy; maximum: 316 mGy); for plutonium the median was 1.27 mGy and for uranium 2.17 mGy. Excess OR/Gy (90% confidence interval)—adjusted for external radiation, socioeconomic status, and smoking—was 11 (2.6, 24) for total alpha dose, 50 (17, 106) for plutonium, and 5.3 (−1.9, 18) for uranium. Conclusions: We found strong evidence for associations between low doses from alpha-emitters and lung cancer risk. The excess OR/Gy was greater for plutonium than uranium, though confidence intervals overlap. Risk estimates were similar to those estimated previously in plutonium workers, and in uranium miners exposed to radon and its progeny. Expressed as risk/equivalent dose in sieverts (Sv), our estimates are somewhat larger than but consistent with those for atomic bomb survivors. See video abstract at, http://links.lww.com/EDE/B232. PMID:28520643

Occurrence of Uranium Ores in the Schist Formation of the Pre-Ordovician Portugal; OCCURENCE DE MINERAIS D'URANIUM DANS LES FORMATIONS DE SCHISTES ANTE-ORDOVICIENS

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

Lobato, C.P.; Ferrao, C.N.

1959-10-31

The occurrence of uranium ores in concentrations of economical interest in the pre-ordovician schists was noted by the first time, in the region of Pinhel, in November 1958. The occurrence is situated in a zone of graphitic brown-greyish schists which are enclosed in a formation of gneiss with tourmaline near the contact of the latter with the hercinian granite, which constitutes the Beiras' Massif. The uraniferous mineralization is constituted by autunite down to the depth which has been reached by the explorntion work. The radiometric study and the sampling taken nt the depth of about ten meters suggest the continuitymore » of the structure and the persistence of the mineralization associated with it. The structural type and the distribution of the mineralization in the joints and the brecciated zone of the schists suggest that the deposition of uranium ore is not syngenetic, but, rather, that it is attribated to the circulation of mineralized solutions through the breakage produced along the hypothermal veilns, in a posterior reopening connected to the last movements of the alpidic orogenesis. The content obtained in the sampling reveals the existence of an enlarged ore deposit following the directions of the schistosity, wfth an extension of 140 meters and with the medium content of 0.27% U/sub 3/O/ sub 8/. (auth)« less

Uranium Biomineralization By Natural Microbial Phosphatase Activities in the Subsurface

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

Taillefert, Martial

This project investigated the geochemical and microbial processes associated with the biomineralization of radionuclides in subsurface soils. During this study, it was determined that microbial communities from the Oak Ridge Field Research subsurface are able to express phosphatase activities that hydrolyze exogenous organophosphate compounds and result in the non-reductive bioimmobilization of U(VI) phosphate minerals in both aerobic and anaerobic conditions. The changes of the microbial community structure associated with the biomineralization of U(VI) was determined to identify the main organisms involved in the biomineralization process, and the complete genome of two isolates was sequenced. In addition, it was determined thatmore » both phytate, the main source of natural organophosphate compounds in natural environments, and polyphosphate accumulated in cells could also be hydrolyzed by native microbial population to liberate enough orthophosphate and precipitate uranium phosphate minerals. Finally, the minerals produced during this process are stable in low pH conditions or environments where the production of dissolved inorganic carbon is moderate. These findings suggest that the biomineralization of U(VI) phosphate minerals is an attractive bioremediation strategy to uranium bioreduction in low pH uranium-contaminated environments. These efforts support the goals of the SBR long-term performance measure by providing key information on "biological processes influencing the form and mobility of DOE contaminants in the subsurface".« less

Health Effects and Environmental Justice Concerns of Exposure to Uranium in Drinking Water.

PubMed

Corlin, Laura; Rock, Tommy; Cordova, Jamie; Woodin, Mark; Durant, John L; Gute, David M; Ingram, Jani; Brugge, Doug

2016-12-01

We discuss the recent epidemiologic literature regarding health effects of uranium exposure in drinking water focusing on the chemical characteristics of uranium. While there is strong toxicologic evidence for renal and reproductive effects as well as DNA damage, the epidemiologic evidence for these effects in people exposed to uranium in drinking water is limited. Further, epidemiologic evidence is lacking for cardiovascular and oncogenic effects. One challenge in characterizing health effects of uranium in drinking water is the paucity of long-term cohort studies with individual level exposure assessment. Nevertheless, there are environmental justice concerns due to the substantial exposures for certain populations. For example, we present original data suggesting that individuals living in the Navajo Nation are exposed to high levels of uranium in unregulated well water used for drinking. In 10 out of 185 samples (5.4 %), concentrations of uranium exceeded standards under the Safe Drinking Water Act. Therefore, efforts to mitigate exposure to toxic elements in drinking water are warranted and should be prioritized.

National Uranium Resource Evaluation. Volume 1. Summary of the geology and uranium potential of Precambrian conglomerates in southeastern Wyoming

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

Karlstrom, K.E.; Houston, R.S.; Flurkey, A.J.

1981-02-01

A series of uranium-, thorium-, and gold-bearing conglomerates in Late Archean and Early Proterozoic metasedimentary rocks have been discovered in southern Wyoming. The mineral deposits were found by applying the time and strata bound model for the origin of uranium-bearing quartz-pebble conglomerates to favorable rock types within a geologic terrane known from prior regional mapping. No mineral deposits have been discovered that are of current (1981) economic interest, but preliminary resource estimates indicate that over 3418 tons of uranium and over 1996 tons of thorium are present in the Medicine Bow Mountains and that over 440 tons of uranium andmore » 6350 tons of thorium are present in Sierra Madre. Sampling has been inadequate to determine gold resources. High grade uranium deposits have not been detected by work to date but local beds of uranium-bearing conglomerate contain as much as 1380 ppM uranium over a thickness of 0.65 meters. This project has involved geologic mapping at scales from 1/6000 to 1/50,000 detailed sampling, and the evaluation of 48 diamond drill holes, but the area is too large to fully establish the economic potential with the present information. This first volume summarizes the geologic setting and geologic and geochemical characteristics of the uranium-bearing conglomerates. Volume 2 contains supporting geochemical data, lithologic logs from 48 drill holes in Precambrian rocks, and drill site geologic maps and cross-sections from most of the holes. Volume 3 is a geostatistical resource estimate of uranium and thorium in quartz-pebble conglomerates.« less

Summary of the mineralogy of the Colorado Plateau uranium ores

USGS Publications Warehouse

Weeks, Alice D.; Coleman, Robert Griffin; Thompson, Mary E.

1956-01-01

In the Colorado Plateau uranium has been produced chiefly from very shallow mines in carnotite ores (oxidized vanadiferous uranium ores) until recent deeper mining penetrated black unoxidized ores in water-saturated rocks and extensive exploration has discovered many deposits of low to nonvanadiferous ores. The uranium ores include a wide range from highly vanadiferous and from as much as one percent to a trace of copper, and contain a small amount of iron and traces of lead, zinc, molybdenum, cobalt, nickel, silver, manganese, and other metals. Recent investigation indicates that the carnotite ores have been derived by progressive oxidation of primary (unoxidized) black ores that contain low-valent uranium and vanadium oxides and silicates. The uranium minerals, uraninite and coffinite, are associated with coalified wood or other carbonaceous material. The vanadium minerals, chiefly montroseite, roscoelite, and other vanadium silicates, occur in the interstices of the sandstone and in siltstone and clay pellets as well as associated with fossil wood. Calcite, dolomite, barite and minor amounts of sulfides, arsenides, and selenides occur in the unoxidized ore. Partially oxidized vanadiferous ore is blue black, purplish brown, or greenish black in contrast to the black or dark gray unoxidized ore. Vanadium combines with uranium to form rauvite. The excess vanadium is present in corvusite, fernandinite, melanovanadite and many other quadrivalent and quinquevalent vanadium minerals as well as in vanadium silicates. Pyrite and part or all of the calcite are replaced by iron oxides and gypsum. In oxidized vanadiferous uranium ores the uranium is fixed in the relatively insoluble minerals carnotite and tyuyamunite, and the excess vanadium commonly combines with one or more of the following: calcium, sodium, potassium, magnesium, aluminum, iron, copper, manganese, or barium, or rarely it forms the hydrated pentoxide. The relatively stable vanadium silicates are little affected by oxidation. The unoxidized nonvanadiferous ores contain uraninite and coffinite in close association with coalified wood and iron and copper sulfides, and traces of many other sulfides, arsenides and selenides. The oxidized nonvanadiferous ores differ from the vanadiferous ores because, in the absence of vanadium to complex the uranium, a great variety of secondary yellow and greenish-yellow uranyl minerals are formed. The uranyl sulfates and carbonates are more common than the oxides, phosphates, arsenates, and silicates. Because the sulfates and carbonates are much less stable that carnotite, the oxidized nonvanadiferous ores occure only as halos around cores of unoxidized ore and do not form large oxidized deposits close to the surface of the ground as carnotite ores. Oxidation has taken place since the lowering of the water table in the present erosion cycle. Because of local structures and the highly lenticular character of the fluviatile host rocks perched water tables and water-saturated lenses of sandstone are common high above the regional water table. Unoxidized ore has been preserved in these water-saturated rocks and the boundary between oxidized and unoxidized ore is very irregular.

Study on the Classification of the Uranium Mineral of Venta de Cardena; ESTUDIO SOBRE LA CLASIFICACION DEL MINERAL DE VENTA DE CARDENA

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

Otero, A.R.

1959-01-01

The behavior of uranium mineral from Venta de Cardena in a spiral classifier which operates in a closed system with a ball mill was studied to obtain data for the design of a milling-classification system with a production capacity of 200 tons per day with a particle size less than 0.417 mm. The characteristics of such a system, the problems in normal operation, the inconveriences which these cause, and their solution were investigated. Correlations between these tests and the results obtained with long glass tubes are presented. (J.S.R.)

Analysis by Activation. Part III. Simultaneous Determination of Copper and Uranium in Minerals by Radioactivation; ANALISES POR ATIVACAO. PARTE III. DETERMINACAO SIMULTANEA DE OURO E URANIC NOS MINERAIS POR RADIOATIVACAO

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

Abrao, A.

1959-04-01

ABS>Copper and uranium frequently associated in the same mineral, can be qualitatively and quantitatlvely determined by means of the radioisotopes Au/sup 198/ and Np/sup 239/ formed during the irradiation of the mineral in a reactor The copper is separated from the neptunium and fission products by anion resin without the addition of isotopic carriers. The efficiency of the chemical separation and the purity of the two radioisotopes is controlled by gamma spectroscopy and bidetermination of the half lives. (tr-auth)

Petrography, fluid inclusion analysis, and geochronology of the End uranium deposit, Kiggavik, Nunavut, Canada

NASA Astrophysics Data System (ADS)

Chi, Guoxiang; Haid, Taylor; Quirt, David; Fayek, Mostafa; Blamey, Nigel; Chu, Haixia

2017-02-01

The End deposit is one of several uranium deposits in the Kiggavik area near the Proterozoic Thelon Basin, which is geologically similar to the Athabasca Basin known for its unconformity-related uranium deposits. The mineralization occurs as uraninite and coffinite in quartz veins and wall rocks (psammopelitic gneisses) in the sub-Thelon basement and is associated with clay- and hematite-altered fault zones. Fluid inclusions were studied in quartz cementing unmineralized breccias formed before mineralization (Q2), quartz veins that were formed before mineralization but spatially associated with uranite (Q4), and calcite veins that were formed after mineralization. Four types of fluid inclusions were recognized, namely liquid-dominated biphase (liquid + vapor), vapor-dominated biphase (vapor + liquid), monophase (vapor-only), and triphase (liquid + vapor + halite) inclusions. The first three types were found in Q2, whereas all four types were found in Q4 and calcite. The coexistence of these different types of inclusions within individual fluid inclusion assemblages is interpreted to indicate fluid immiscibility and heterogeneous trapping. Based on microthermometry, the fluids associated with Q2 are characterized by low salinities (0.4 to 6.6 wt%) and moderate temperatures from 148 to 261 °C, and the fluids associated with calcite show high salinities (26.8 to 29.3 wt%) and relatively low temperatures from 146 to 205 °C, whereas the fluids associated with Q4 have a wide range of salinities from 0.7 to 38.8 wt% and temperatures from 80 to 332 °C. Microthermometric and cryogenic Raman spectroscopic studies indicate that the high-salinity fluids in Q4 and calcite belong to the H2O-NaCl-CaCl2 ± MgCl2 system, with some dominated by NaCl and others by CaCl2. The fluid inclusions in Q2 are interpreted to be unrelated to mineralization, whereas those in Q4 and calcite reflect the mineralizing fluids. The fluid inclusion data are consistent with a genetic link of mineralization with basinal brines derived from the Thelon Basin. However, unlike the conventional deep-burial (>5 km) diagenetic-hydrothermal model proposed for the unconformity-related uranium deposits, the uranium mineralization in the End deposit is inferred to have formed in a shallow environment (probably <2 km), based on fluid immiscibility and low fluid pressures obtained in this study. The U-Pb age of uraninite (1295 ± 12 Ma) is interpreted to reflect isotopic resetting after the primary mineralization.

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

U redox fronts and kaolinisation in basement-hosted unconformity-related U ores of the Athabasca Basin (Canada): late U remobilisation by meteoric fluids

NASA Astrophysics Data System (ADS)

Mercadier, Julien; Cuney, Michel; Cathelineau, Michel; Lacorde, Mathieu

2011-02-01

Proterozoic basement-hosted unconformity-related uranium deposits of the Athabasca Basin (Saskatchewan, Canada) were affected by significant uranium redistribution along oxidation-reduction redox fronts related to cold and late meteoric fluid infiltration. These redox fronts exhibit the same mineralogical and geochemical features as the well-studied uranium roll-front deposits in siliclastic rocks. The primary hydrothermal uranium mineralisation (1.6-1.3 Ga) of basement-hosted deposits is strongly reworked to new disseminated ores comprising three distinctly coloured zones: a white-green zone corresponding to the previous clay-rich alteration halo contemporaneous with hydrothermal ores, a uranium front corresponding to the uranium deposition zone of the redox front (brownish zone, rich in goethite) and a hematite-rich red zone marking the front progression. The three zones directly reflect the mineralogical zonation related to uranium oxides (pitchblende), sulphides, iron minerals (hematite and goethite) and alumino-phosphate-sulphate (APS) minerals. The zoning can be explained by processes of dissolution-precipitation along a redox interface and was produced by the infiltration of cold (<50°C) meteoric fluids to the hydrothermally altered areas. U, Fe, Ca, Pb, S, REE, V, Y, W, Mo and Se were the main mobile elements in this process, and their distribution within the three zones was, for most of them, directly dependent on their redox potential. The elements concentrated in the redox fronts were sourced by the alteration of previously crystallised hydrothermal minerals, such as uranium oxides and light rare earth element (LREE)-rich APS. The uranium oxides from the redox front are characterised by LREE-enriched patterns, which differ from those of unconformity-related ores and clearly demonstrate their distinct conditions of formation. Uranium redox front formation is thought to be linked to fluid circulation episodes initiated during the 400-300 Ma period during uplift and erosion of the Athabasca Basin when it was near the Equator and to have been still active during the last million years. A major kaolinisation event was caused by changes in the fluid circulation regime, reworking the primary uranium redox fronts and causing the redistribution of elements originally concentrated in the uranium-enriched meteoric-related redox fronts.

Influence of microwaves on the leaching kinetics of uraninite from a low grade ore in dilute sulfuric acid.

PubMed

Madakkaruppan, V; Pius, Anitha; T, Sreenivas; Giri, Nitai; Sarbajna, Chanchal

2016-08-05

This paper describes a study on microwave assisted leaching of uranium from a low-grade ore of Indian origin. The host rock for uranium mineralization is chlorite-biotite-muscovite-quartzo-feldspathic schist. The dominant presence of siliceous minerals determined leaching of uranium values in sulfuric acid medium under oxidizing conditions. Process parametric studies like the effect of sulfuric acid concentration (0.12-0.50M), redox potential (400-500mV), particle size (600-300μm) and temperature (35°-95°C) indicated that microwave assisted leaching is more efficient in terms of overall uranium dissolution, kinetics and provide relatively less impurities (Si, Al, Mg and Fe) in the leach liquor compared to conventional conductive leaching. The kinetics of leaching followed shrinking core model with product layer diffusion as controlling mechanism. Copyright © 2016 Elsevier B.V. All rights reserved.

Surface Functionalized Nanostructured Ceramic Sorbents for the Effective Collection and Recovery of Uranium from Seawater

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

Chouyyok, Wilaiwan; Pittman, Jonathan W.; Warner, Marvin G.

2016-05-02

The ability to collect uranium from seawater offers the potential for a nearly limitless fuel supply for nuclear energy. We evaluated the use of functionalized nanostructured sorbents for the collection and recovery of uranium from seawater. Extraction of trace minerals from seawater and brines is challenging due to the high ionic strength of seawater, low mineral concentrations, and fouling of surfaces over time. We demonstrate that rationally assembled sorbent materials that integrate high affinity surface chemistry and high surface area nanostructures into an application relevant micro/macro structure enables collection performance that far exceeds typical sorbent materials. High surface area nanostructuredmore » silica with surface chemistries composed of phosphonic acid, phosphonates, 3,4 hydroxypyridinone, and EDTA showed superior performance for uranium collection. A few phosphorous-based commercial resins, specifically Diphonix and Ln Resin, also performed well. We demonstrate an effective and environmentally benign method of stripping the uranium from the high affinity sorbents using inexpensive nontoxic carbonate solutions. The cyclic use of preferred sorbents and acidic reconditioning of materials was shown to improve performance. Composite thin films composed of the nanostructured sorbents and a porous polymer binder are shown to have excellent kinetics and good capacity while providing an effective processing configuration for trace mineral recovery from solutions. Initial work using the composite thin films shows significant improvements in processing capacity over the previously reported sorbent materials.« less

Rare-earth element fractionation in uranium ore and its U(VI) alteration minerals

DOE PAGES

Balboni, Enrica; Spano, T; Cook, N; ...

2017-10-20

We developed a cation exchange chromatography method employing sulfonated polysterene cation resin (DOWEX AG50-X8) in order to separate rare-earth elements (REEs) from uranium-rich materials. The chemical separation scheme is designed to reduce matrix effects and consequently yield enhanced ionization efficiencies for concentration determinations of REEs without significant fractionation using solution mode-inductively coupled plasma mass spectrometry (ICP-MS) analysis. This method was then applied to determine REE abundances in four uraninite (ideally UO 2) samples and their associated U(VI) alteration minerals. In three of the samples analyzed, the concentration of REEs for primary uraninite are higher than those for their corresponding secondarymore » uranium alteration phases. The results for U(VI) alteration minerals of two samples indicate enrichment of the light REEs (LREEs) over the heavy REEs (HREEs). This differential mobilization is attributed to differences in the mineralogical composition of the U(VI) alteration. There is a lack of fractionation of the LREEs in the uraninite alteration rind that is composed of U(VI) minerals containing Ca 2+ as the interlayer cation (uranophane and bequerelite); contrarily, U(VI) alteration minerals containing K + and Pb 2+ as interlayer cations (fourmarierite, dumontite) indicate fractionation (enrichment) of the LREEs. Our results have implications for nuclear forensic analyses since a comparison is reported between the REE abundances for the CUP-2 (processed uranium ore) certified reference material and previously determined values for uranium ore concentrate (UOC) produced from the same U deposit (Blind River/Elliott Lake, Canada). UOCs represent the most common form of interdicted nuclear material and consequently is material frequently targeted for forensic analysis. The comparison reveals similar chondrite normalized REE signatures but variable absolute abundances. Based on the results reported here, the latter may be attributed to the differing REE abundances between primary ore and associated alteration phases, and/or is related to varying fabrication processes adopted during production of UOC.« less

Rare-earth element fractionation in uranium ore and its U(VI) alteration minerals

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

Balboni, Enrica; Spano, T; Cook, N

We developed a cation exchange chromatography method employing sulfonated polysterene cation resin (DOWEX AG50-X8) in order to separate rare-earth elements (REEs) from uranium-rich materials. The chemical separation scheme is designed to reduce matrix effects and consequently yield enhanced ionization efficiencies for concentration determinations of REEs without significant fractionation using solution mode-inductively coupled plasma mass spectrometry (ICP-MS) analysis. This method was then applied to determine REE abundances in four uraninite (ideally UO 2) samples and their associated U(VI) alteration minerals. In three of the samples analyzed, the concentration of REEs for primary uraninite are higher than those for their corresponding secondarymore » uranium alteration phases. The results for U(VI) alteration minerals of two samples indicate enrichment of the light REEs (LREEs) over the heavy REEs (HREEs). This differential mobilization is attributed to differences in the mineralogical composition of the U(VI) alteration. There is a lack of fractionation of the LREEs in the uraninite alteration rind that is composed of U(VI) minerals containing Ca 2+ as the interlayer cation (uranophane and bequerelite); contrarily, U(VI) alteration minerals containing K + and Pb 2+ as interlayer cations (fourmarierite, dumontite) indicate fractionation (enrichment) of the LREEs. Our results have implications for nuclear forensic analyses since a comparison is reported between the REE abundances for the CUP-2 (processed uranium ore) certified reference material and previously determined values for uranium ore concentrate (UOC) produced from the same U deposit (Blind River/Elliott Lake, Canada). UOCs represent the most common form of interdicted nuclear material and consequently is material frequently targeted for forensic analysis. The comparison reveals similar chondrite normalized REE signatures but variable absolute abundances. Based on the results reported here, the latter may be attributed to the differing REE abundances between primary ore and associated alteration phases, and/or is related to varying fabrication processes adopted during production of UOC.« less

The role of extracellular DNA in uranium precipitation and biomineralisation.

PubMed

Hufton, Joseph; Harding, John H; Romero-González, Maria E

2016-10-26

Bacterial extra polymeric substances (EPS) have been associated with the extracellular precipitation of uranium. Here we report findings on the biomineralisation of uranium, with extracellular DNA (eDNA) used as a model biomolecule representative of EPS. The complexation and precipitation of eDNA with uranium were investigated as a function of pH, ionic strength and varying concentrations of reactants. The role of phosphate moieties in the biomineralisation mechanism was studied by enzymatically releasing phosphate (ePO 4 ) from eDNA compared to abiotic phosphate (aPO 4 ). The eDNA-uranium precipitates and uranium minerals obtained were characterised by Attenuated Total Reflectance-Fourier Transform Infrared (ATR-FT-IR) spectroscopy, Scanning Electron Microscopy-Energy Dispersive X-Ray analysis (SEM-EDX), X-Ray Powder Diffraction (XRD) and X-Ray Photoelectron Spectroscopy (XPS). ATR-FT-IR showed that at pH 5, the eDNA-uranium precipitation mechanism was predominantly mediated by interactions with phosphate moieties from eDNA. At pH 2, the uranium interactions with eDNA occur mainly through phosphate. The solubility equilibrium was dependent on pH with the formation of precipitate reduced as the pH increased. The XRD data confirmed the formation of a uranium phosphate precipitate when synthesised using ePO 4 . XPS and SEM-EDX studies showed the incorporation of carbon and nitrogen groups from the enzymatic orthophosphate hydrolysis on the obtained precipitated. These results suggested that the removal of uranium from solution occurs via two mechanisms: complexation by eDNA molecules and precipitation of a uranium phosphate mineral of the type (UO 2 HPO 4 )·xH 2 O by enzymatic orthophosphate hydrolysis. This demonstrated that eDNA from bacterial EPS is a key contributor to uranium biomineralisation.

Application of total-count aeroradiometric maps to the exploration for heavy-mineral deposits in the coastal plain of Virginia, with a section on field-spectrometer-data reduction

USGS Publications Warehouse

Grosz, A.E.; Kosanke, Kenneth L.

1983-01-01

Total-count contoured aeroradiometric maps for the Coastal Plain of Virginia were used in an effort to locate economic heavy-mineral placer deposits. The principle behind this approach is that heavy- mineral suites commonly contain radioactive minerals that, if the concentration of heavy minerals is exposed at or within inches of the surface, enable the deposit to be located by use of airborne instruments because of its radiometric contrast with the host sediment. Detailed and regional geologic maps, soil maps, land-use and land- cover maps, information on fertilizer use, and ground-spectrometer data were used to study aeroradiometric anomalies for efficient exploration. Aeroradiometric anomalies in the Coastal Plain of Virginia have three general causes. First, the most intense anomalies are associated with cultural features, such as roads made of granitic material. Second, most anomalies of high to intermediate intensity are associated with land used for agricultural purposes and evidently are caused by applications of radioactive fertilizer. Third, anomalies of intermediate to low intensity are associated with heavy-mineral deposits. Results of this study show that aeroradiometric anomalies associated with heavy-mineral accumulations in the Coastal Plain of Virginia have ground radiometric spectra in which thorium is the strongest component and uranium and potassium are lesser components. Heavy-mineral accumulations found in this study by use of the aeroradiometric data are not considered to be of economic importance, mostly because of the low percentage of economic minerals in the heavy-mineral suites and also because of other factors such as the very fine grained nature of the host sediments and competing land use.

A record of uranium-series transport at Nopal I, Sierra Pena Blanca, Mexico: Implications for natural uranium deposits and radioactive waste repositories

DOE PAGES

Denton, J. S.; Goldstein, S. J.; Paviet, P.; ...

2016-04-10

Studies of uranium-series (U-series) disequilibria within and around ore deposits provide valuable information on the extent and timing of actinide mobility, via mineral-fluid interaction, over a range of spatial and temporal scales. Such information is useful in studies of analogs of high-level nuclear-waste repositories, as well as for mining and mineral extraction sites, locations of previous nuclear weapons testing, and legacy nuclear waste contamination. In this study we present isotope dilution mass spectrometry U-series measurements for fracture-fill materials (hematite, goethite, kaolinite, calcite, dolomite and quartz) from one such analog; the Nopal I uranium ore deposit situated at Peña Blanca inmore » the Chihuahua region of northern Mexico. The ore deposit is located in fractured, unsaturated volcanic tuff and fracture-fill materials from surface fractures as well as fractures in a vertical drill core have been analyzed. High uranium concentrations in the fracture-fill materials (between 12 and 7700 ppm) indicate uranium mobility and transport from the deposit. Furthermore, uranium concentrations generally decrease with horizontal distance away from the deposit but in this deposit there is no trend with depth below the surface.« less

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

Catalano, Jeffrey G.; Giammar, Daniel E.; Wang, Zheming

Phosphate addition is an in situ remediation approach that may enhance the sequestration of uranium without requiring sustained reducing conditions. However, the geochemical factors that determine the dominant immobilization mechanisms upon phosphate addition are insufficiently understood to design efficient remediation strategies or accurately predict U(VI) transport. The overall objective of our project is to determine the dominant mechanisms of U(VI)-phosphate reactions in subsurface environments. Our research approach seeks to determine the U(VI)-phosphate solid that form in the presence of different groundwater cations, characterize the effects of phosphate on U(VI) adsorption and precipitation on smectite and iron oxide minerals, examples ofmore » two major reactive mineral phases in contaminated sediments, and investigate how phosphate affects U(VI) speciation and fate during water flow through sediments from contaminated sites. The research activities conducted for this project have generated a series of major findings. U(VI) phosphate solids from the autunite mineral family are the sole phases to form during precipitation, with uranyl orthophosphate not occurring despite its predicted greater stability. Calcium phosphates may take up substantial quantities of U(VI) through three different removal processes (adsorption, coprecipitation, and precipitation) but the dominance of each process varies with the pathway of reaction. Phosphate co-adsorbs with U(VI) onto smectite mineral surfaces, forming a mixed uranium-phosphate surface complex over a wide range of conditions. However, this molecular-scale association of uranium and phosphate has not effect on the overall extent of uptake. In contrast, phosphate enhanced U(VI) adsorption to iron oxide minerals at acidic pH conditions but suppresses such adsorption at neutral and alkaline pH, despite forming mixed uranium-phosphate surface complexes during adsorption. Nucleation barriers exist that inhibit U(VI) phosphate solids from precipitating in the presence of smectite and iron oxide minerals as well as sediments from contaminated sites. Phosphate addition enhances retention of U(VI) by sediments from the Rifle, CO and Hanford, WA field research sites, areas containing substantial uranium contamination of groundwater. This enhanced retention is through adsorption processes. Both fast and slow uptake and release behavior is observed, indicating that diffusion of uranium between sediment grains has a substantial effect of U(VI) fate in flowing groundwater systems. This project has revealed the complexity of U(VI)-phosphate reactions in subsurface systems. Distinct chemical processes occur in acidic and alkaline groundwater systems. For the latter, calcium phosphate formation, solution complexation, and competition between phosphate and uranium for adsorption sites may serve to either enhance or inhibit U(VI) removal from groundwater. Under the groundwater conditions present at many contaminated sites in the U.S., phosphate appears to general enhance U(VI) retention and limit transport. However, formation of low-solubility uranium phosphate solids does not occur under field-relevant conditions, despite this being the desired product of phosphate-based remediation approaches. In addition, simple equilibrium approaches fail to well-predict uranium fate in contaminated sediments amended with phosphate, with reactive transport models that include reaction rates and mass transport through occluded domains needed to properly describe the system. Phosphate addition faces challenges to being effective as a stand-alone groundwater treatment approach but would prove beneficial as an add-on to other treatment methods that will further limit uranium migration in the subsurface.« less

Chemical treatment of low-grade uranium ores. Extraction of uranium from tricalcium phosphate; TRAITEMENT CHIMIQUE DES MINERAIS PAUVRES D'URANIUM. EXTRACTION DE L'URANIUM DU PHOSPHATE TRICALCIQUE (in French)

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

Mechelynck, Ph.

1958-07-15

After an examination of the different processes for the treatment of uranium minerals, it is concluded that the extraction of uranium by ion exchange is not applicable to hydrochloric acid solutions of phosphates. A sulfuric or phosphoric solution can be used. For solvent extraction of uranium, sulfuric or phosphoric solutions are the best, but hydrochloric solutions can be used. The cost of the solvents used would determine the cost of the operation. It is necessary, in the case of liquid-liquid extraction, to filter or decant the solution before extraction. (tr-auth)

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).

A summary of niobium and rare earth localities from Ha'il and other areas in western Saudi Arabia: a preliminary study

USGS Publications Warehouse

Matzko, John J.; Naqvi, Mohammed Ibne

1978-01-01

Investigations in 1965 located veins containing radioactive material in the Halaban Group on the east side of a granite pluton at Jabal Aja near Ha'il. Later study extended the known area of radioactivity to a total length of about 30 km. Mineralogic studies indicated that the samples were low in uranium and that the radioactivity was due principally to thorium in niobium-bearing minerals. Two samples were reexamined to identify the sources of radioactivity, but X-ray and alpha plate studies did not reveal the radioactive minerals, even though uranium mineralization was indicated by the alpha plates. Further sampling is suggested to isolate the sources of radioactivity. This study indicates that niobium occurrences are related to alkaline intrusives in many areas of western Saudi Arabia. These areas should be investigated for their possible niobium and rare earth contents; their uranium content is apparently too low to be of economic interest.

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. Copyright © 2016 Elsevier Ltd. All rights reserved.

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

Denton, J. S.; Goldstein, S. J.; Paviet, P.

Studies of uranium-series (U-series) disequilibria within and around ore deposits provide valuable information on the extent and timing of actinide mobility, via mineral-fluid interaction, over a range of spatial and temporal scales. Such information is useful in studies of analogs of high-level nuclear-waste repositories, as well as for mining and mineral extraction sites, locations of previous nuclear weapons testing, and legacy nuclear waste contamination. In this study we present isotope dilution mass spectrometry U-series measurements for fracture-fill materials (hematite, goethite, kaolinite, calcite, dolomite and quartz) from one such analog; the Nopal I uranium ore deposit situated at Peña Blanca inmore » the Chihuahua region of northern Mexico. The ore deposit is located in fractured, unsaturated volcanic tuff and fracture-fill materials from surface fractures as well as fractures in a vertical drill core have been analyzed. High uranium concentrations in the fracture-fill materials (between 12 and 7700 ppm) indicate uranium mobility and transport from the deposit. Furthermore, uranium concentrations generally decrease with horizontal distance away from the deposit but in this deposit there is no trend with depth below the surface.« less

LEUKEMIA, LYMPHOMA AND MULTIPLE MYELOMA MORTALITY (1950–1999) AND INCIDENCE (1969–1999) IN THE ELDORADO URANIUM WORKERS COHORT

PubMed Central

Zablotska, Lydia B.; Lane, Rachel S.D.; Frost, Stanley E.; Thompson, Patsy A.

2014-01-01

Uranium workers are chronically exposed to low levels of radon decay products (RDP) and gamma (γ) radiation. Risks of leukemia from acute and high doses of γ-radiation are well-characterized, but risks from lower doses and dose-rates and from RDP exposures are controversial. Few studies have evaluated risks of other hematologic cancers in uranium workers. The purpose of this study was to analyze radiation-related risks of hematologic cancers in the cohort of Eldorado uranium miners and processors first employed in 1932–1980 in relation to cumulative RDP exposures and γ-ray doses. The average cumulative RDP exposure was 100.2 working level months and the average cumulative whole-body γ-radiation dose was 52.2 millisievert. We identified 101 deaths and 160 cases of hematologic cancers in the cohort. Overall, male workers had lower mortality and cancer incidence rates for all outcomes compared with the general Canadian male population, a likely healthy worker effect. No statistically significant association between RDP exposure or γ-ray doses, or a combination of both, and mortality or incidence of any hematologic cancer was found. We observed consistent but non-statistically significant increases in risks of chronic lymphocytic leukemia (CLL) and Hodgkin lymphoma (HL) incidence and non-Hodgkin lymphoma (NHL) mortality with increasing γ-ray doses. These findings are consistent with recent studies of increased risks of CLL and NHL incidence after γ-radiation exposure. Further research is necessary to understand risks of other hematologic cancers from low-dose exposures to γ-radiation. PMID:24583244

INDIAN PEAKS WILDERNESS, COLORADO.

USGS Publications Warehouse

Pearson, Robert C.; Speltz, Charles N.

1984-01-01

The Indian Peaks Wilderness northwest of Denver is partly within the Colorado Mineral Belt, and the southeast part of it contains all the geologic characteristics associated with the several nearby mining districts. Two deposits have demonstrated mineral resources, one of copper and the other of uranium; both are surrounded by areas with probable potential. Two other areas have probable resource potential for copper, gold, and possibly molydenum. Detailed gravity and magnetic studies in the southeast part of the Indian Peaks Wilderness might detect in the subsurface igneous bodies that may be mineralized. Physical exploration such as drilling would be necessary to determine more precisely the copper resources at the Roaring Fork locality and uranium resources at Wheeler Basin.

Modelling of the dissolution and reprecipitation of uranium under oxidising conditions in the zone of shallow groundwater circulation.

PubMed

Dutova, Ekaterina M; Nikitenkov, Aleksei N; Pokrovskiy, Vitaly D; Banks, David; Frengstad, Bjørn S; Parnachev, Valerii P

2017-11-01

Generic hydrochemical modelling of a grantoid-groundwater system, using the Russian software "HydroGeo", has been carried out with an emphasis on simulating the accumulation of uranium in the aqueous phase. The baseline model run simulates shallow granitoid aquifers (U content 5 ppm) under conditions broadly representative of southern Norway and southwestern Siberia: i.e. temperature 10 °C, equilibrated with a soil gas partial CO 2 pressure (P CO2 , open system) of 10 -2.5 atm. and a mildly oxidising redox environment (Eh = +50 mV). Modelling indicates that aqueous uranium accumulates in parallel with total dissolved solids (or groundwater mineralisation M - regarded as an indicator of degree of hydrochemical evolution), accumulating most rapidly when M = 550-1000 mg L -1 . Accumulation slows at the onset of saturation and precipitation of secondary uranium minerals at M = c. 1000 mg L -1 (which, under baseline modelling conditions, also corresponds approximately to calcite saturation and transition to Na-HCO 3 hydrofacies). The secondary minerals are typically "black" uranium oxides of mixed oxidation state (e.g. U 3 O 7 and U 4 O 9 ). For rock U content of 5-50 ppm, it is possible to generate a wide variety of aqueous uranium concentrations, up to a maximum of just over 1 mg L -1 , but with typical concentrations of up to 10 μg L -1 for modest degrees of hydrochemical maturity (as indicated by M). These observations correspond extremely well with real groundwater analyses from the Altai-Sayan region of Russia and Norwegian crystalline bedrock aquifers. The timing (with respect to M) and degree of aqueous uranium accumulation are also sensitive to Eh (greater mobilisation at higher Eh), uranium content of rocks (aqueous concentration increases as rock content increases) and P CO2 (low P CO2 favours higher pH, rapid accumulation of aqueous U and earlier saturation with respect to uranium minerals). Copyright © 2017 Elsevier Ltd. All rights reserved.

Fate and transport of heavy metals and radioelements in groundwater aquifers of Al-Qunfudhah and Wadi Haliy quadrangles, southwest of Saudi Arabia

NASA Astrophysics Data System (ADS)

Bajabaa, S. A.; Abd El-Naby, H.; Dawood, Y.

2009-12-01

The fate and transport of heavy metals and radioelements in groundwater aquifers in five wadis located in the Al Qunfudhah and Wadi Haliy quadrangles were investigated. These wadis are an important source of water to the Red Sea coastal plain. Copper, zinc and other base-metals mineralization occur at eastern parts of these quadrangles that dominates the water catchments area of these wadis. Water, rock and soil samples were collected from all wadis and they were analyzed for major, trace elements, heavy metals and stable isotopes. The chemical and isotopic results showed active water/rock interaction. The preliminary investigation of the data analyses showed some samples with high heavy metals and uranium contents. Generally, the uranium and heavy metal contents are higher in samples collected from the upstream area of each wadi where the crystalline rocks are exposed and direct contact with the runoff. The uranium contents were as high as 120 ppb in some water samples. These elevated values are mainly due to two factors water rock interaction and concentration through evaporation. It was also observed to have elevated heavy metal contents near mining activates, which suggests that these mining activates are playing an important role in mobilizing the heavy elements and in turn affecting the water quality in these wadis.

A moral history of the evolution of a caste of workers.

PubMed Central

Samuels, S W

1996-01-01

Using a dialectic method of philosophic inquiry, the actual ethical, legal, and social situation associated with genetic testing of beryllium-exposed workers in Department of Energy nuclear weapons facilities for markers of chronic beryllium disease is described. The cultural evolution of a caste system in a similar situation, and its social and biological implications, among uranium miners in the Erz Gebirge of Central Europe and on the Colorado Plateau of the United States, marked by suicide and lung disease, including cancer, is also described. The historically persistent social disease resulting from these situations. The Masada Syndrome, named from an analogous situation in biblical times, is characterized. Cultural intervention, a necessary condition for the ethical progression of the Human Genome Project, is outlined. PMID:8933047

On the distribution of uranium in hair: Non-destructive analysis using synchrotron radiation induced X-ray fluorescence microprobe techniques

NASA Astrophysics Data System (ADS)

Israelsson, A.; Eriksson, M.; Pettersson, H. B. L.

2015-06-01

In the present study the distribution of uranium in single human hair shafts has been evaluated using two synchrotron radiation (SR) based micro X-ray fluorescence techniques; SR μ-XRF and confocal SR μ-XRF. The hair shafts originated from persons that have been exposed to elevated uranium concentrations. Two different groups have been studied, i) workers at a nuclear fuel fabrication factory, exposed mainly by inhalation and ii) owners of drilled bedrock wells exposed by ingestion of water. The measurements were carried out on the FLUO beamline at the synchrotron radiation facility ANKA, Karlsruhe. The experiment was optimized to detect U with a beam size of 6.8 μm × 3 μm beam focus allowing detection down to ppb levels of U in 10 s (SR μ-XRF setup) and 70 s (SR confocal μ-XRF setup) measurements. It was found that the uranium was present in a 10-15 μm peripheral layer of the hair shafts for both groups studied. Furthermore, potential external hair contamination was studied by scanning of unwashed hair shafts from the workers. Sites of very high uranium signal were identified as particles containing uranium. Such particles, were also seen in complementary analyses using variable pressure electron microscope coupled with energy dispersive X-ray analyzer (ESEM-EDX). However, the particles were not visible in washed hair shafts. These findings can further increase the understanding of uranium excretion in hair and its potential use as a biomonitor.

A multi-instrumental geochemical study of anomalous uranium enrichment in coal.

PubMed

Havelcová, Martina; Machovič, Vladimír; Mizera, Jiří; Sýkorová, Ivana; Borecká, Lenka; Kopecký, Lubomír

2014-11-01

Contents of uranium in coals from Odeř in the northernmost part of the Sokolov Basin, Czech Republic, in the vicinity of the well known St. Joachimsthal uranium ore deposits, reach extremely high values. In the present work, coal samples with contents of uranium ranging from 0.02 to 6 wt.% were studied. The study employing a whole complex of analytical techniques has been aimed at identification of changes in the structure of coal organic matter, which are associated with the high contents of uranium in coal. The study includes proximate and ultimate analyses, multielement analysis by instrumental neutron and photon activation analyses, micropetrographic analysis by optical microscopy, ESEM/EDX analysis of mineral matter, infrared and Raman spectroscopies, solvent extraction followed by gas chromatography with mass spectroscopy (GC/MS), and analytical pyrolysis (Py-GC/MS). The study has confirmed previously proposed explanation of uraniferous mineralization in sedimentary carboniferous substances by the mechanism of reduction and fixation of soluble U(VI) (uranyl, UO2(2+)) species (e.g., humic, carbonate/hydroxo/phosphate complexes) by sedimentary organic matter under diagenetic or hydrothermal conditions, and formation of insoluble U(IV) species as phosphate minerals and uraninite. The process is accompanied with alteration and destruction of the coal organic matter. The changes in the structure of coal organic matter involve dehydrogenation and oxidation mainly in the aliphatic, aromatic and hydroxyl structures, and an increase in aromaticity, content of ether bonds, and the degree of coalification. Copyright © 2014 Elsevier Ltd. All rights reserved.

A microfluidic approach to water-rock interactions using thin rock sections: Pb and U sorption onto thin shale and granite sections.

PubMed

Oh, Youn Soo; Jo, Ho Young; Ryu, Ji-Hun; Kim, Geon-Young

2017-02-15

The feasibility of using microfluidic tests to investigate water-rock (mineral) interactions in fractures regarding sorption onto thin rock sections (i.e., shale and granite) of lead (Pb) and uranium (U) was evaluated using a synthetic PbCl 2 solution and uranium-containing natural groundwater as fluids. Effluent composition and element distribution on the thin rock sections before and after microfluidic testing were analyzed. Most Pb removal (9.8mg/cm 2 ) occurred within 3.5h (140 PVF), which was 74% of the total Pb removal (13.2mg/cm 2 ) at the end of testing (14.5h, 560 PVF). Element composition on the thin shale sections determined by μ-XRF analysis indicated that Pb removal was related primarily to Fe-containing minerals (e.g., pyrite). Two thin granite sections (biotite rich, Bt-R and biotite poor, Bt-P) exhibited no marked difference in uranium removal capacity, but a slightly higher amount of uranium was removed onto the thin Bt-R section (266μg/cm 2 ) than the thin Bt-P section (240μg/cm 2 ) within 120h (4800 PVF). However, uranium could not be detected by micro X-ray fluorescence (μ-XRF) analysis, likely due to the detection limit. These results suggest that microfluidic testing on thin rock sections enables quantitative evaluation of rock (mineral)-water interactions at the micro-fracture or pore scale. Copyright © 2016 Elsevier B.V. All rights reserved.

Reconnaissance of uranium and copper deposits in parts of New Mexico, Colorado, Utah, Idaho, and Wyoming

USGS Publications Warehouse

Gott, Garland B.; Erickson, Ralph L.

1952-01-01

Because of the common association of uranium and copper in several of the commercial uranium deposits in the Colorado Plateau Province, a reconnaissance was made of several known deposits of copper disseminated through sandstone to determine whether they might be a source of uranium. In order to obtain more information regarding the relationship between copper, uranium and carbonaceous materials, some of the uraniferious asphaltrite deposits in the Shinarump conglomerate along the west flank of the San Rafael Swell were also investigated briefly. During this reconnaissance 18 deposits were examined in New Mexico, eight in Utah, two in Idaho, and one each in Wyoming and Colorado. No uranium deposits of commercial grade are associated with the copper deposits that were examined. The uraniferous asphaltites in the Shinarump conglomerate of Triassic age on the west flank of the San Rafael Swell, however, are promising from the standpoint of commercial uranium production. Spectrographic analyses of crude oil, asphalt, and bituminous shales show a rather consistent suite of trace metals including vanadium, nickel, copper, cobalt, chromium, lead zinc, and molybdenum. The similarity of the metal assemblage, including uranium of the San Rafael Swell asphaltites, to the metal assemblage in crude oil and other bituminous materials suggests that these metals were concentrated in the asphaltites from petroleum. However, the hypothesis that uranium minerals were already present before the hydrocarbons were introduced and that some sort of replacement or uranium minerals by carbon compounds was effected after the petroleum migrated into the uranium deposit should not be disregarded. The widespread association of uranium with asphaltic material suggests that it also may have been concentrated by some agency connected with the formation of petroleum. The problem of the association of uranium and other trace metals with hydrocarbons should be studied further both in the field and in the laboratory.

Uranium Biomineralization by Natural Microbial Phosphatase Activities in the Subsurface

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

Sobecky, Patricia A.

2015-04-06

In this project, inter-disciplinary research activities were conducted in collaboration among investigators at The University of Alabama (UA), Georgia Institute of Technology (GT), Lawrence Berkeley National Laboratory (LBNL), Brookhaven National Laboratory (BNL), the DOE Joint Genome Institute (JGI), and the Stanford Synchrotron Radiation Light source (SSRL) to: (i) confirm that phosphatase activities of subsurface bacteria in Area 2 and 3 from the Oak Ridge Field Research Center result in solid U-phosphate precipitation in aerobic and anaerobic conditions; (ii) investigate the eventual competition between uranium biomineralization via U-phosphate precipitation and uranium bioreduction; (iii) determine subsurface microbial community structure changes of Areamore » 2 soils following organophosphate amendments; (iv) obtain the complete genome sequences of the Rahnella sp. Y9-602 and the type-strain Rahnella aquatilis ATCC 33071 isolated from these soils; (v) determine if polyphosphate accumulation and phytate hydrolysis can be used to promote U(VI) biomineralization in subsurface sediments; (vi) characterize the effect of uranium on phytate hydrolysis by a new microorganism isolated from uranium-contaminated sediments; (vii) utilize positron-emission tomography to label and track metabolically-active bacteria in soil columns, and (viii) study the stability of the uranium phosphate mineral product. Microarray analyses and mineral precipitation characterizations were conducted in collaboration with DOE SBR-funded investigators at LBNL. Thus, microbial phosphorus metabolism has been shown to have a contributing role to uranium immobilization in the subsurface.« less

Uranium potential of precambrian rocks in the Raft River area of northwestern Utah and south-central Idaho. Final report

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

Black, B.A.

1980-09-01

A total of 1214 geochemical samples were collected and analyzed. The sampling media included 334 waters, 616 stream sediments, and 264 rocks. In addition, some stratigraphic sections of Elba and Yost Quartzites and Archean metasedimentary rock were measured and sampled and numerous radiation determinations made of the various target units. Statistical evaluation of the geochemical data permitted recognition of 156 uranium anomalies, 52 in water, 79 in stream sediment, and 25 in rock. Geographically, 68 are located in the Grouse Creek Mountains, 43 in the Raft River Mountains, and 41 in the Albion Range. Interpretation of the various data leadsmore » to the conclusion that uranium anomalies relate to sparingly and moderately soluble uraniferous heavy minerals, which occur as sparse but widely distributed magmatic, detrital, and/or metamorphically segregated components in the target lithostratigraphic units. The uraniferous minerals known to occur and believed to account for the geochemical anomalies include allanite, monazite, zircon, and apatite. In some instances samarskite may be important. These heavy minerals contain uranium and geochemically related elements, such as Th, Ce, Y, and Zr, in sufficient quantities to account for both the conspicuous lithologic preference and the generally observed low amplitude of the anomalies. The various data generated in connection with this study, as well as those available in the published literature, collectively support the conclusion that the various Precambrian W and X lithostratigraphic units pre-selected for evaluation probably lack potential to host important Precambrian quartz-pebble conglomerate uranium deposits. Moreover it is also doubted that they possess any potential to host Proterozoic unconformity-type uranium deposits.« less

Diatremes of the Hopi Buttes, Arizona; chemical and statistical analyses

USGS Publications Warehouse

Wenrich, K.J.; Mascarenas, J.F.

1982-01-01

Lacustrine sediments deposited in maar lakes of the Hopi Buttes diatremes are hosts for uranium mineralization of as much as 1500 ppm. The monchiquites and limburgite turfs erupted from the diatremes are distinguished from normal alkalic basalts of the Colorado Plateau by their extreme silica undersaturation and high water, TiO2, and P2O5 contents. Many trace elements are also unusually abundant, including Ag, As, Ba, Be, Ce, Dy, Eu, F, Gd, Hf, La, Nd, Pb, Rb, Se, Sm, Sn, Sr, Ta, Tb, Th, U, V, Zn, and Zr. The lacustrine sediments, which consist predominantly of travertine and clastic rocks, are the hosts for syngenetic and epigenetic uranium mineralization of as much as 1500 ppm uranium. Fission track maps show the uranium to be disseminated within the travertine and clastic rocks, and although microprobe analyses have not, as yet, revealed discrete uranium-bearing phases, the clastic rocks show a correlation of high Fe, Ti, and P with areas of high U. Correlation coefficients show that for the travertines, clastics, and limburgite ruffs, Mo, As, Sr, Co, and V appear to have the most consistent and strongest correlations with uranium. Many elements, including many of the rare-earth elements, that are high in these three rocks are also high in the monchiquites, as compared to the average crustal abundance for the respective rock type. This similar suite of anomalous elements, which includes such immobile elements as the rare earths, suggests that Fluids which deposited the travertines were related to the monchiquitic magma. The similar age of about 5 m.y. for both the lake beds and the monchiquites also appears to support this source for the mineralizing fluids.

Uranophane at Silver Cliff mine, Lusk, Wyoming

USGS Publications Warehouse

Wilmarth, Verl R.; Johnson, D.H.

1954-01-01

The uranium deposit at the Silver Cliff mine near Lusk, Wyo., consists primarily of uranophane which occurs as fracture fillings and small replacement pockets in faulted and fractured calcareous sandstone of Cambrian (?) age. The country rock in the vicinity of the mine is schist of pre-Cambrian age intruded by pegmatite dikes and is unconformably overlain by almost horizontal sandstone of Cambrian(?) age. The mine is on the southern end of the Lusk Dome, a local structure probably related to the Hartville uplift. In the immediate vicinity of the mine, the dome is cut by the Silver Cliff fault, a north-trending high-angle reverse fault about 1,200 feet in length with a stratigraphic throw of 70 feet. Uranophane, metatorbernite, pitchblende, calcite, native silver, native copper, chalcocite, azurite, malachite, chrysocolla, and cuprite have been deposited in fractured sandstone. The fault was probably mineralized throughout its length, but because of erosion, the mineralized zone is discontinuous. The principal ore body is about 800 feet long. The width and depth of the mineralized zone are not accurately known but are at least 20 feet and 60 feet respectively. The uranium content of material sampled in the mine ranges from 0.001 to 0.23 percent uranium, whereas dump samples range from 0.076 to 3.39 percent uranium.

Depleted and enriched uranium exposure quantified in former factory workers and local residents of NL Industries, Colonie, NY USA

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

Arnason, John G.

Background: Between 1958 and 1982, NL Industries manufactured components of enriched (EU) and depleted uranium (DU) at a factory in Colonie NY, USA. More than 5 metric tons of DU was deposited as microscopic DU oxide particles on the plant site and surrounding residential community. A prior study involving a small number of individuals (n=23) indicated some residents were exposed to DU and former workers to both DU and EU, most probably through inhalation of aerosol particles. Objectives: Our aim was to measure total uranium [U] and the uranium isotope ratios: {sup 234}U/{sup 238}U; {sup 235}U/{sup 238}U; and {sup 236}U/{supmore » 238}U, in the urine of a cohort of former workers and nearby residents of the NLI factory, to characterize individual exposure to natural uranium (NU), DU, and EU more than 3 decades after production ceased. Methods: We conducted a biomonitoring study in a larger cohort of 32 former workers and 99 residents, who may have been exposed during its period of operation, by measuring Total U, NU, DU, and EU in urine using Sector Field Inductively Coupled Plasma - Mass Spectrometry (SF-ICP-MS). Results: Among workers, 84% were exposed to DU, 9% to EU and DU, and 6% to natural uranium (NU) only. For those exposed to DU, urinary isotopic and [U] compositions result from binary mixing of NU and the DU plant feedstock. Among residents, 8% show evidence of DU exposure, whereas none shows evidence of EU exposure. For residents, the [U] geometric mean is significantly below the value reported for NHANES. There is no significant difference in [U] between exposed and unexposed residents, suggesting that [U] alone is not a reliable indicator of exposure to DU in this group. Conclusions: Ninety four percent of workers tested showed evidence of exposure to DU, EU or both, and were still excreting DU and EU decades after leaving the workforce. The study demonstrates the advantage of measuring multiple isotopic ratios (e.g., {sup 236}U/{sup 238}U and {sup 235}U/{sup 238}U) over a single ratio ({sup 235}U/{sup 238}U) in determining sources of uranium exposure. - Highlights: • Biomonitoring study of residents and former workers exposed to DU in Colonie NY. • Urine (99 residents+32 former workers) analyzed for depleted uranium (DU). • DU detected in 84% of workers and 8% of residents >30 years after plant closed. • Enriched uranium detected in 6% of former workers based on isotope ratios.« less

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 formed extensive biofilms or flocs that contained U and V in the exopolymer, but excluded these metals from the bacteria. This suggests a specific mechanism to inhibit metal sorption to cell wall components. The example illustrates the interplay between bacteria and minerals under conditions that model oligotrophic survival, and provides insight on U mobilization from common uranium ore minerals.

Distribution of Major and trace elements in Koppunuru area, Guntur district, Andhra Pradesh, India.

PubMed

Arumugam, K; Srinivasalu, S; Purvaja, R; Ramesh, R

2018-06-01

From koppunuru study area totally 58 samples were collected in 7 different boreholes, minimum depth of 28 m and Maximum depth of 157.7 m. The borehole samples geochemical analysis (major and trace elements) was carried out at Atomic Minerals Directorate for Exploration & Research (AMD), Hyderabad, India. Major and trace element studies have been conducted on the Neoproterozoic Palnad sub-basin Andhra Pradesh, South India, to determine their Geochemistry, Uranium mineralization and provenance characteristics. Geochemically, this sedimentary basin has a different litho - unit like as gritty quartzite, conglomerate, and Shale. This study area mainly dominated by Uranium deposited and radioactive elements are predominately deposit. Strong positive correlation between Uranium and Lead ( r = 0.887) suggested radiogenic nature of this system.

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.

Intense alpha-particle emitting crystallites in uranium mill wastes

USGS Publications Warehouse

Landa, E.R.; Stieff, L.R.; Germani, M.S.; Tanner, A.B.; Evans, J.R.

1994-01-01

Nuclear emulsion microscopy has demonstrated the presence of small, intense ??-particle emitting crystallites in laboratory-produced tailings derived from the sulfuric acid milling of uranium ores. The ??-particle activity is associated with the isotope pair 210Pb 210Po, and the host mineral appears to be PbSO4 occurring as inclusions in gypsum laths. These particles represent potential inhalation hazards at uranium mill tailings disposal areas. ?? 1994.

Depleted and enriched uranium exposure quantified in former factory workers and local residents of NL Industries, Colonie, NY USA.

PubMed

Arnason, John G; Pellegri, Christine N; Moore, June L; Lewis-Michl, Elizabeth L; Parsons, Patrick J

2016-10-01

Between 1958 and 1982, NL Industries manufactured components of enriched (EU) and depleted uranium (DU) at a factory in Colonie NY, USA. More than 5 metric tons of DU was deposited as microscopic DU oxide particles on the plant site and surrounding residential community. A prior study involving a small number of individuals (n=23) indicated some residents were exposed to DU and former workers to both DU and EU, most probably through inhalation of aerosol particles. Our aim was to measure total uranium [U] and the uranium isotope ratios: (234)U/(238)U; (235)U/(238)U; and (236)U/(238)U, in the urine of a cohort of former workers and nearby residents of the NLI factory, to characterize individual exposure to natural uranium (NU), DU, and EU more than 3 decades after production ceased. We conducted a biomonitoring study in a larger cohort of 32 former workers and 99 residents, who may have been exposed during its period of operation, by measuring Total U, NU, DU, and EU in urine using Sector Field Inductively Coupled Plasma - Mass Spectrometry (SF-ICP-MS). Among workers, 84% were exposed to DU, 9% to EU and DU, and 6% to natural uranium (NU) only. For those exposed to DU, urinary isotopic and [U] compositions result from binary mixing of NU and the DU plant feedstock. Among residents, 8% show evidence of DU exposure, whereas none shows evidence of EU exposure. For residents, the [U] geometric mean is significantly below the value reported for NHANES. There is no significant difference in [U] between exposed and unexposed residents, suggesting that [U] alone is not a reliable indicator of exposure to DU in this group. Ninety four percent of workers tested showed evidence of exposure to DU, EU or both, and were still excreting DU and EU decades after leaving the workforce. The study demonstrates the advantage of measuring multiple isotopic ratios (e.g., (236)U/(238)U and (235)U/(238)U) over a single ratio ((235)U/(238)U) in determining sources of uranium exposure. Copyright © 2016 Elsevier Inc. All rights reserved.

Biomineralization of U(VI) phosphate promoted by microbially-mediated phytate hydrolysis in contaminated soils

NASA Astrophysics Data System (ADS)

Salome, Kathleen R.; Beazley, Melanie J.; Webb, Samuel M.; Sobecky, Patricia A.; Taillefert, Martial

2017-01-01

The bioreduction of uranium may immobilize a significant fraction of this toxic contaminant in reduced environments at circumneutral pH. In oxic and low pH environments, however, the low solubility of U(VI)-phosphate minerals also makes them good candidates for the immobilization of U(VI) in the solid phase. As inorganic phosphate is generally scarce in soils, the biomineralization of U(VI)-phosphate minerals via microbially-mediated organophosphate hydrolysis may represent the main immobilization process of uranium in these environments. In this study, contaminated sediments were incubated aerobically in two pH conditions to examine whether phytate, a naturally-occurring and abundant organophosphate in soils, could represent a potential phosphorous source to promote U(VI)-phosphate biomineralization by natural microbial communities. While phytate hydrolysis was not evident at pH 7.0, nearly complete hydrolysis was observed both with and without electron donor at pH 5.5, suggesting indigenous microorganisms express acidic phytases in these sediments. While the rate of hydrolysis of phytate generally increased in the presence of uranium, the net rate of inorganic phosphate production in solution was decreased and inositol phosphate intermediates were generated in contrast to similar incubations conducted without uranium. These findings suggest uranium stress enhanced the phytate-metabolism of the microbial community, while simultaneously inhibiting phosphatase production and/or activity by the indigenous population. Finally, phytate hydrolysis drastically decreased uranium solubility, likely due to formation of ternary sorption complexes, U(VI)-phytate precipitates, and U(VI)-phosphate minerals. Overall, the results of this study provide evidence for the ability of natural microbial communities to liberate phosphate from phytate in acidic sediments, possibly as a detoxification mechanism, and demonstrate the potential utility of phytate-promoted uranium immobilization in subsurface environments. These processes should be investigated in more detail with pure cultures isolated from these sediments.

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

Kuzmina, L.A.

A method has been developed for determining uranium, thorium, and ionium (Th/sup 230/) in sea silt from a single sample. The completeness of isolation and radiochemical purity of thorium isotopes have been tested by means of tracers. The method has been proved on samples of sea silt as well as of rocks, ores, and minerals. It is applicable at thorium content from 5 x 10/sup -5/ to x x 10/sup - 4/% when uranium content is x x 10/sup -4/ % and at uranium content up to 70% when ionium contert is x x 10/sup -4/% (uranium equivalent). (tr-auth)

Final Technical Report

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

Sobecky, Patricia A; Taillefert, Martial

This final technical report describes results and findings from a research project to examine the role of microbial phosphohydrolase enzymes in naturally occurring subsurface microorganisms for the purpose of promoting the immobilization of the radionuclide uranium through the production of insoluble uranium phosphate minerals. The research project investigated the microbial mechanisms and the physical and chemical processes promoting uranium biomineralization and sequestration in oxygenated subsurface soils. Uranium biomineralization under aerobic conditions can provide a secondary biobarrier strategy to immobilize radionuclides should the metal precipitates formed by microbial dissimilatory mechanisms remobilize due to a change in redox state.

SLURRY SOLVENT EXTRACTION PROCESS FOR THE RECOVERY OF METALS FROM SOLID MATERIALS

DOEpatents

Grinstead, R.R.

1959-01-20

A solvent extraction process is described for recovering uranium from low grade uranium bearing minerals such as carnotit or shale. The finely communited ore is made up as an aqueous slurry containing the necessary amount of acid to solubilize the uranium and simultaneously or subsequently contacted with an organic solvent extractant such as the alkyl ortho-, or pyro phosphoric acids, alkyl phosphites or alkyl phosphonates in combination with a diluent such as kerosene or carbon tetrachlorids. The extractant phase is separated from the slurry and treated by any suitable process to recover the uranium therefrom. One method for recovering the uranium comprises treating the extract with aqueous HF containing a reducing agent such as ferrous sulfate, which reduces the uranium and causes it to be precipitated as uranium tetrafluoride.

Uranium ores and depleted uranium in the environment, with a reference to uranium in the biosphere from the Erzgebirge/Sachsen, Germany.

PubMed

Meinrath, A; Schneider, P; Meinrath, G

2003-01-01

The Erzgebirge ('Ore Mountains') area in the eastern part of Germany was a major source of uranium for Soviet nuclear programs between 1945 and 1989. During this time, the former German Democratic Republic became the third largest uranium producer in the world. The high abundance of uranium in the geological formations of the Erzgebirge are mirrored in the discovery of uranium by M. Klaproth close to Freiberg City in 1789 and the description of the so-called 'Schneeberg' disease, lung cancer caused in miners by the accumulation of the uranium decay product, radon, in the subsurfaces of shafts. Since 1991, remediation and mitigation of uranium at production facilities, rock piles and mill tailings has taken place. In parallel, efforts were initiated to assess the likely adverse effects of uranium mining to humans. The costs of these activities amount to about 6.5 10(9) Euro. A comparison with concentrations of depleted uranium at certain sites is given.

Uranium deposits at the Jomac mine, White Canyon area, San Juan County, Utah

USGS Publications Warehouse

Trites, A.F.; Hadd, G.A.

1955-01-01

azurite, and chalcanthite occur locally with the uranium minerals. Principal ore guides at the Jomac mine are channels, and scours at the bottom of these channels coal-bearing sandstone or conglomerate at the base of the Shinarump conglomerate, coal, and jarosite.

10 CFR 39.2 - Definitions.

Code of Federal Regulations, 2012 CFR

2012-01-01

... neutron generator tube to produce neutrons for use in well logging applications. Uranium sinker bar means a weight containing depleted uranium used to pull a logging tool toward the bottom of a well. Well... drilled holes for the purpose of oil, gas, mineral, groundwater, or geological exploration. Well logging...

10 CFR 39.2 - Definitions.

Code of Federal Regulations, 2013 CFR

2013-01-01

... neutron generator tube to produce neutrons for use in well logging applications. Uranium sinker bar means a weight containing depleted uranium used to pull a logging tool toward the bottom of a well. Well... drilled holes for the purpose of oil, gas, mineral, groundwater, or geological exploration. Well logging...

10 CFR 39.2 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-01-01

... neutron generator tube to produce neutrons for use in well logging applications. Uranium sinker bar means a weight containing depleted uranium used to pull a logging tool toward the bottom of a well. Well... drilled holes for the purpose of oil, gas, mineral, groundwater, or geological exploration. Well logging...

10 CFR 39.2 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-01-01

... neutron generator tube to produce neutrons for use in well logging applications. Uranium sinker bar means a weight containing depleted uranium used to pull a logging tool toward the bottom of a well. Well... drilled holes for the purpose of oil, gas, mineral, groundwater, or geological exploration. Well logging...

10 CFR 39.2 - Definitions.

Code of Federal Regulations, 2011 CFR

2011-01-01

... neutron generator tube to produce neutrons for use in well logging applications. Uranium sinker bar means a weight containing depleted uranium used to pull a logging tool toward the bottom of a well. Well... drilled holes for the purpose of oil, gas, mineral, groundwater, or geological exploration. Well logging...

Geology of the Ralston Buttes district, Jefferson County, Colorado: a preliminary report

USGS Publications Warehouse

Sheridan, Douglas M.; Maxwell, Charles H.; Albee, Arden L.; Van Horn, Richard

1956-01-01

The Ralston Buttes district in Jefferson County is one of the most significant new uranium districts located east of the Continental Divide in Colorado. The district is east of the Colorado Front Range mineral belt, along the east front of the range. From November 1953 through October 1956, about 10,000 tons of uranium ore, much of which was high-grade pitchblende-bearing vein material, was shipped from the district. The ore occurs in deposits that range in size from bodies containing less than 50 tons to ore shoots containing over 1,000 tons. The only other mining activity in the area has been a sporadic production of beryl, feldspar, and scrap mica from Precambrian pegmatites, and quarrying of dimension stone, limestone, and clay from sedimentary rocks. Most of the Ralston Buttes district consists of complexly folded Precambrian metamorphic and igneous rocks - gneiss, schist, quartzite, amphibolite, and granodiorite. Paleozoic and Mesozoic sedimentary rocks crop out in the northeastern part of the district. These rocks are cut by northwesterly-trending fault systems of Laramide age and by small bodies of intrusive rocks that are Tertiary in age. The typical uranium deposits in the district are hydrothermal veins occupying openings in Laramide fault breccias or related fractures that cut the Precambrian rocks. Pitchblende and lesser amounts of secondary uranium minerals are associated with sparse base-mental sulfides in a gangue of carbonate minerals, potash feldspar, and, more rarely, quartz. Less common types of deposits consist of pitchblende and secondary uranium minerals that occupy fractures cutting pegmatites and quartz veins. The uranium deposits are concentrated in two areas, the Ralston Creek area and the Golden Gate Canyon area. The deposits in the Ralston Creek area are located along the Rogers fault system, and the deposits in the Golden Gate Canyon area are along the Hurricane Hill fault system. Two geologic factors were important to the localization of the uranium deposits: (1) favorable structural environment and (2) favorable host rocks. The deposits in each of the two major areas are located where a northwesterly-trending Laramide fault system splits into a complex network of faults. Also, most of the deposits appear to be localized where the faults cut Precambrian rocks rich in hornblende, biotite, or garnet and biotite. The ore controls recognized in this relatively new uranium district may have wider application in areas of similar geology elsewhere in the Front Range.

Drinking Water with Uranium below the U.S. EPA Water Standard Causes Estrogen Receptor–Dependent Responses in Female Mice

PubMed Central

Raymond-Whish, Stefanie; Mayer, Loretta P.; O’Neal, Tamara; Martinez, Alisyn; Sellers, Marilee A.; Christian, Patricia J.; Marion, Samuel L.; Begay, Carlyle; Propper, Catherine R.; Hoyer, Patricia B.; Dyer, Cheryl A.

2007-01-01

Background The deleterious impact of uranium on human health has been linked to its radioactive and heavy metal–chemical properties. Decades of research has defined the causal relationship between uranium mining/milling and onset of kidney and respiratory diseases 25 years later. Objective We investigated the hypothesis that uranium, similar to other heavy metals such as cadmium, acts like estrogen. Methods In several experiments, we exposed intact, ovariectomized, or pregnant mice to depleted uranium in drinking water [ranging from 0.5 μg/L (0.001 μM) to 28 mg/L (120 μM). Results Mice that drank uranium-containing water exhibited estrogenic responses including selective reduction of primary follicles, increased uterine weight, greater uterine luminal epithelial cell height, accelerated vaginal opening, and persistent presence of cornified vaginal cells. Coincident treatment with the antiestrogen ICI 182,780 blocked these responses to uranium or the synthetic estrogen diethylstilbestrol. In addition, mouse dams that drank uranium-containing water delivered grossly normal pups, but they had significantly fewer primordial follicles than pups whose dams drank control tap water. Conclusions Because of the decades of uranium mining/milling in the Colorado plateau in the Four Corners region of the American Southwest, the uranium concentration and the route of exposure used in these studies are environmentally relevant. Our data support the conclusion that uranium is an endocrine-disrupting chemical and populations exposed to environmental uranium should be followed for increased risk of fertility problems and reproductive cancers. PMID:18087588

Uranium and organic matters: use of pyrolysis-gas chromatography, carbon, hydrogen, and uranium contents to characterize the organic matter from sandstone-type deposits

USGS Publications Warehouse

Leventhal, Joel S.

1979-01-01

Organic matter seems to play an important role in the genesis of uranium deposits in sandstones in the western United States. Organic materials associated with ore from the Texas coastal plain, Tertiary basins of Wyoming, Grants mineral belt of New Mexico, and the Uravan mineral belt of Utah and Colorado vary widely in physical appearance and chemical composition. Partial characterization of organic materials is achieved by chemical analyses to determine atomic hydrogen-to-carbon (H/C) ratios and by gas chromatographic analyses to determine the molecular fragments evolved during stepwise pyrolysis. From the pyrolysis experiments the organic materials can be classified and grouped: (a) lignites from Texas and Wyoming and (b) hydrogen poor materials, from Grants and Uravan mineral belts and Wyoming; (c) naphthalene-containing materials from Grants mineral belt and Wyoming; and (d) complex and aromatic materials from Uravan, Grants and Wyoming. The organic materials analyzed have atomic H/C ratios that range from approximately 0.3 to at least 1.5. The samples with higher H/C ratios yield pyrolysis products that contain as many as 30 carbon atoms per molecule. Samples with low H/C ratios are commonly more uraniferous and yield mostly methane and low-molecular-weight gases during pyrolysis.

Geochemical soil sampling for deeply-buried mineralized breccia pipes, northwestern Arizona

USGS Publications Warehouse

Wenrich, K.J.; Aumente-Modreski, R. M.

1994-01-01

Thousands of solution-collapse breccia pipes crop out in the canyons and on the plateaus of northwestern Arizona; some host high-grade uranium deposits. The mineralized pipes are enriched in Ag, As, Ba, Co, Cu, Mo, Ni, Pb, Sb, Se, V and Zn. These breccia pipes formed as sedimentary strata collapsed into solution caverns within the underlying Mississippian Redwall Limestone. A typical pipe is approximately 100 m (300 ft) in diameter and extends upward from the Redwall Limestone as much as 1000 m (3000 ft). Unmineralized gypsum and limestone collapses rooted in the Lower Permian Kaibab Limestone or Toroweap Formation also occur throughout this area. Hence, development of geochemical tools that can distinguish these unmineralized collapse structures, as well as unmineralized breccia pipes, from mineralized breccia pipes could significantly reduce drilling costs for these orebodies commonly buried 300-360 m (1000-1200 ft) below the plateau surface. Design and interpretation of soil sampling surveys over breccia pipes are plagued with several complications. (1) The plateau-capping Kaibab Limestone and Moenkopi Formation are made up of diverse lithologies. Thus, because different breccia pipes are capped by different lithologies, each pipe needs to be treated as a separate geochemical survey with its own background samples. (2) Ascertaining true background is difficult because of uncertainties in locations of poorly-exposed collapse cones and ring fracture zones that surround the pipes. Soil geochemical surveys were completed on 50 collapse structures, three of which are known mineralized breccia pipes. Each collapse structure was treated as an independent geochemical survey. Geochemical data from each collapse feature were plotted on single-element geochemical maps and processed by multivariate factor analysis. To contrast the results between geochemical surveys (collapse structures), a means of quantifying the anomalousness of elements at each site was developed. This degree of anomalousness, named the "correlation value", was used to rank collapse features by their potential to overlie a deeply-buried mineralized breccia pipe. Soil geochemical results from the three mineralized breccia pipes (the only three of the 50 that had previously been drilled) show that: (1) Soils above the SBF pipe contain significant enrichment of Ag, Al, As, Ba, Ga, K, La, Mo, Nd, Ni, Pb, Sc, Th, U and Zn, and depletion in Ca, Mg and Sr, in contrast to soils outside the topographic and structural rim; (2) Soils over the inner treeless zone of the Canyon pipe show Mo and Pb enrichment anf As and Ga depletion, in contrast to soils from the surrounding forest; and (3) The soil survey of the Mohawk Canyon pipe was a failure because of the rocky terrane and lack of a B soil horizon, or because the pipe plunges. At least 11 of the 47 other collapse structures studied contain anomalous soil enrichments similar to the SBF uranium ore-bearing pipe, and thus have good potential as exploration targets for uranium. One of these 11, #1102, does contain surface mineralized rock. These surveys suggest that soil geochemical sampling is a useful tool for the recognition of many collapse structures with underlying ore-bearing breccia pipes. ?? 1994.

Geological and geochemical investigations of uranium occurrences in the Arrastre Lake area of the Medicine Bow Mountains, Wyoming

USGS Publications Warehouse

Miller, W. Roger; Houston, R.S.; Karlstrom, K.E.; Hopkins, D.M.; Ficklin, W.H.

1977-01-01

Metasedimentary rocks of Precambrian X age in and near the Snowy Range wilderness study area of southeastern Wyoming are lithologically and chronologically similar to those on the north shore of Lake Huron in Canada. The rocks in Canada contain major deposits of uranium in quartz-pebble conglomerates near the base of the metasedimentary sequence. Similar conglomerates in the Deep Lake Formation in the Medicine Bow Mountains of southeastern Wyoming are slightly radioactive and may contain deposits of uranium and other valuable heavy metals. During the summer of 1976, a geological and geochemical pilot study was conducted in the vicinity of Arrastre Lake in the Medicine Bow Mountains to determine the most effective exploration methods for evaluating the uranium potential of the Snowy Range wilderness study area. The area around Arrastre Lake was selected because of the presence of a radioactive lens within a quartz-pebble conglomerate of the Deep Lake Formation. The results of the survey indicate possible uranium mineralization in the subsurface rocks of this formation. The radon content of the dilute waters of the area is much higher than can be accounted for by the uranium content of the surface rocks. Two sources for the high content of the radon are possible. In either case, the high values of radon obtained in this study are a positive indication of uranium mineralization in the subsurface rocks. The determination of the radon content of water samples is the recommended geochemical technique for uranium exploration in the area. The determination of uranium in water and in organic-rich bog material is also recommended.

Geology of the Shinarump No. 1 uranium mine, Seven Mile Canyon area, Grand County, Utah

USGS Publications Warehouse

Finch, Warren Irvin

1954-01-01

The geology of the Shinarump No. 1 uranium mine, located about 12 miles northwest of Moab, Utah, in the Seven Mile Canyon area, Grand County, Utah, was studied to determine the habits, ore controls, and possible origin of the deposit. Rocks of Permian, Triassic, and Jurassic age crop out in the area mapped, and uranium deposits are found in three zones in the lower 25 feet of the Chinle formation of Late Triassic age. The Shinarump No. 1 mine, which is in the lowermost zone, is located on the west flank of the Moab anticline near the Moab fault. The Shinarump No. 1 uranium deposit consists of discontinuous lenticular layers of mineralized rock, irregular in outline, that, in general, follow the bedding. Ore minerals, mainly uraninite, impregnate the rock. High-grade ore seams of uraninite and chalcocite occur along bedding planes. Uraninite formed later than, or simultaneous with, most sulfides, and the chalcocite may be of two ages, with some being later than uraninite. Uraninite and chalcocite are concentrated in the more poorly sorted parts of siltstones. In the Seven Mile Canyon area guides to ore inferred from the study of the Shinarump No. 1 deposit are the presence of bleached siltstone, carbonaceous matter, and copper sulfides. Results of spectrographic analysis indicate that the mineralizing solutions contained important amounts of barium, vanadium, uranium, and copper, as well as lesser amounts of strontium, chromium, boron, yttrium, lead, and zinc. The origin of the Shinarump No. 1 deposit is thought to be hydrothermal.

Geology of the Shinarump No. 1 uranium mine, Seven Mile Canyon area, Grand County, Utah

USGS Publications Warehouse

Finch, Warren Irvin

1953-01-01

The Shinarump No. 1 uranium mine is located about 12 miles northwest of Moab, Utah, in the Seven Mile Canyon area, Grand County, Utah. A study was made of the geology of the Shinarump No. 1 mine in order to determine the habits, ore controls, and possible origin of the deposit. Rocks of Permain, Triassic, and Jurassic age crop out in the area mapped. Uranium deposits are found in three zones in the lower 25 feet of the Upper Triassic Chinle formation. The Shinarump No. 1 mine, which is in the lowermost zone, is located on the west flank of the Moab anticline near the Moab fault. The Shinarump No. 1 uranium deposit consists of discontinuous lenticular layers of mineralized rock, irregular in outline, that, in general, follow the bedding. Ore minerals, mainly uranite, impregnate the rock. High-grade seams of uranite and chalcocite occur along bedding planes. Formation of unraninite is later than or simultaneous with most sulfides. Chalcocite may be of two ages, with some being later than uraninite. Uraninite and chalcocite are concentrated in the poorer sorted parts of siltstones. Guides to ore in the Seven Mile Canyon area inferred from the study of the Shinarump No. 1 deposit are the presence of bleached siltstone, copper sulfides, and carbonaceous matter. Results of spectrographic analysis indicated that the mineralizing solutions contained important amounts of barium, vanadium, uranium, and copper as well as lesser amounts of strontium, chromium, boron, yttrium, lead, and zinc. The origin of the Shinarump No. 1 deposit is thought to be hydrothermal, dated as later or early.

Genesis of kasolite associated with aplite-pegmatite at Jabal Sayid, Hijaz region, Kingdom of Saudi Arabia

NASA Astrophysics Data System (ADS)

Dawood, Yehia H.; Harbi, Hesham M.; Abd El-Naby, Hamdy H.

2010-01-01

In this study, we report kasolite Pb(UO 2)SiO 4·(H 2O) for the first time as a main uranyl mineral in the mineralized aplite-pegmatite of Jabal Sayid, Hijaz region. It commonly forms clusters of yellow acicular crystals in the voids and fractures. The mineral chemistry and mineralogical characteristics of kasolite were investigated using different techniques. Calcium, iron and phosphorus are detected in kasolite in addition to its major constituents; uranium, lead and silicon. Lead does not exist as a radiogenic product and not even as a substitute for uranium in the mineral structure. Alternatively, galena mineralization could be considered as a source for lead. The fluoride and carbonate complexes played a significant role in the formation of kasolite. High temperature hydrothermal solutions reacted with pre-existing uranium-bearing metamictized accessory minerals such as pyrochlore, U-rich thorite and zircon to form uranous fluoride complexes. These complexes are predominant in reducing environment and at pH 4. When the fluids approached the surface passing through fracture system, the oxygen fugacity ( fO 2) and the pH increased because of the loss of volatile components. At these conditions, uranous fluorides would convert to uranyl fluoride complexes UO 2F 3-. Further decrease in temperature was associated with the decay of the activity of fluorine ion by the dilution of hydrothermal solutions and precipitation of fluorite. At this condition, uranyl-carbonate complexes are favoured. These complexes were combined later with silica and lead to form kasolite.

28 CFR 79.43 - Proof of employment as a miner.

Code of Federal Regulations, 2011 CFR

2011-07-01

... Service (PHS) in the course of any health studies of uranium workers during or including the period 1942...) Records of federally supported, health-related studies of uranium workers, including: (i) Studies conducted by Geno Saccamanno, M.D., St. Mary's Hospital, Grand Junction, Colorado; and (ii) Studies...

28 CFR 79.43 - Proof of employment as a miner.

Code of Federal Regulations, 2014 CFR

2014-07-01

... Service (PHS) in the course of any health studies of uranium workers during or including the period 1942...) Records of federally supported, health-related studies of uranium workers, including: (i) Studies conducted by Geno Saccamanno, M.D., St. Mary's Hospital, Grand Junction, Colorado; and (ii) Studies...

28 CFR 79.43 - Proof of employment as a miner.

Code of Federal Regulations, 2012 CFR

2012-07-01

... Service (PHS) in the course of any health studies of uranium workers during or including the period 1942...) Records of federally supported, health-related studies of uranium workers, including: (i) Studies conducted by Geno Saccamanno, M.D., St. Mary's Hospital, Grand Junction, Colorado; and (ii) Studies...

28 CFR 79.43 - Proof of employment as a miner.

Code of Federal Regulations, 2013 CFR

2013-07-01

... Service (PHS) in the course of any health studies of uranium workers during or including the period 1942...) Records of federally supported, health-related studies of uranium workers, including: (i) Studies conducted by Geno Saccamanno, M.D., St. Mary's Hospital, Grand Junction, Colorado; and (ii) Studies...

28 CFR 79.43 - Proof of employment as a miner.

Code of Federal Regulations, 2010 CFR

2010-07-01

... Service (PHS) in the course of any health studies of uranium workers during or including the period 1942...) Records of federally supported, health-related studies of uranium workers, including: (i) Studies conducted by Geno Saccamanno, M.D., St. Mary's Hospital, Grand Junction, Colorado; and (ii) Studies...

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)

Determination of the elemental concentration of uranium and thorium in the products and by-products of amang tin tailings process

NASA Astrophysics Data System (ADS)

Alnour, I. A.; Wagiran, H.; Ibrahim, N.; Hamzah, S.; Elias, M. S.

2017-01-01

Amang or tin tailing is processed into concentrated ores and other economical valuable minerals such as monazite, zircon, xenotime, ilmenite etc. Besides that, the tailings from these ores may have a significant potential source of radiation exposure to amang plants' workers. This study was conducted to determine the elemental concentration of uranium and thorium in mineral samples collected from five amang tailing factories. The concentration of uranium and thorium was carried out by using instrumental neutron activation analysis (INAA) relative technique. The concentration of uranium and thorium in ppm obtained in this study are as follows: raw (189-1064) and (622-4965); monazite (1076-1988) and (3467-33578); xenotime 4053 and 5540; zircon (309-3090) and (387-6339); ilmenite (104-583) and (88-1205); rutile (212-889) and (44-1119); pyrite (7-43) and (9-132); and waste (5-338) and (9-1218) respectively. The analysis results shows that the monazite, xenotime and zircon have high content of uranium and thorium, whereas ilmenite, rutile, pyrite and waste have lower concentration compare with raw materials after tailing process. The highest values of uranium and thorium concentrations (4053 ± 428 ppm and 33578 ± 873 ppm, respectively) were observed in xenotime and monazite; whereas the lowest value was 5.48 ± 0.86 ppm of uranium recorded in waste (sand) and 9 ± 0.32 ppm of thorium for waste (sand) and pyrite.

Mineral resources of the Mount Tipton Wilderness Study Area, Mohave County, Arizona

USGS Publications Warehouse

Greene, Robert C.; Turner, Robert L.; Jachens, Robert C.; Lawson, William A.; Almquist, Carl L.

1989-01-01

The Mount Tipton Wilderness Study Area (AZ-020-012/ 042) comprises 33,950 acres in Mohave County, Ariz. At the request of the U.S. Bureau of Land Management, this area was evaluated for identified mineral resources (known) and mineral resource potential (undiscovered). This work was carried out by the U.S. Bureau of Mines and the U.S. Geological Survey in 1984-87. In this report, the area studied is referred to as the "wilderness study area" or simply "the study area." There are no identified mineral resources in the study area. The southernmost part of the study area is adjacent to the Wallapai (Chloride) mining district and has low mineral resource potential for gold, silver, copper, lead, zinc, and molybdenum in hydrothermal veins. This area also has a low mineral resource potential for tungsten in vein deposits and for uranium in vein deposits or pegmatites. In the central part of the wilderness study area, one small area has low mineral resource potential for uranium in vein deposits or pegmatites and another small area has low resource potential for thorium in vein deposits. The entire study area has low resource potential for geothermal energy but no potential for oil or gas resources.

Leukemia, lymphoma and multiple myeloma mortality (1950-1999) and incidence (1969-1999) in the Eldorado uranium workers cohort.

PubMed

Zablotska, Lydia B; Lane, Rachel S D; Frost, Stanley E; Thompson, Patsy A

2014-04-01

Uranium workers are chronically exposed to low levels of radon decay products (RDP) and gamma (γ) radiation. Risks of leukemia from acute and high doses of γ-radiation are well-characterized, but risks from lower doses and dose-rates and from RDP exposures are controversial. Few studies have evaluated risks of other hematologic cancers in uranium workers. The purpose of this study was to analyze radiation-related risks of hematologic cancers in the cohort of Eldorado uranium miners and processors first employed in 1932-1980 in relation to cumulative RDP exposures and γ-ray doses. The average cumulative RDP exposure was 100.2 working level months and the average cumulative whole-body γ-radiation dose was 52.2 millisievert. We identified 101 deaths and 160 cases of hematologic cancers in the cohort. Overall, male workers had lower mortality and cancer incidence rates for all outcomes compared with the general Canadian male population, a likely healthy worker effect. No statistically significant association between RDP exposure or γ-ray doses, or a combination of both, and mortality or incidence of any hematologic cancer was found. We observed consistent but non-statistically significant increases in risks of chronic lymphocytic leukemia (CLL) and Hodgkin lymphoma (HL) incidence and non-Hodgkin lymphoma (NHL) mortality with increasing γ-ray doses. These findings are consistent with recent studies of increased risks of CLL and NHL incidence after γ-radiation exposure. Further research is necessary to understand risks of other hematologic cancers from low-dose exposures to γ-radiation. Copyright © 2014 The Authors. Published by Elsevier Inc. All rights reserved.

Applied technology for mine waste water decontamination in the uranium ores extraction from Romania

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

Bejenaru, C.; Filip, G.; Vacariu, V.T.

1996-12-31

The exploitation of uranium ores in Romania is carried out in underground mines. In all exploited uranium deposits, mine waste waters results and will still result after the closure of uranium ore extraction activity. The mine waters are radioactively contaminated with uranium and its decay products being a hazard both for underground waters as for the environment. This paper present the results of research work carried out by authors for uranium elimination from waste waters as the problems involved during the exploitation process of the existent equipment as its maintenance in good experimental conditions. The main waste water characteristics aremore » discussed: solids as suspension, uranium, radium, mineral salts, pH, etc. The moist suitable way to eliminate uranium from mine waste waters is the ion exchange process based on ion exchangers in fluidized bed. A flowsheet is given with main advantages resulted.« less

A study of contaminated soils near Crucea-Botus, ana uranium mine (East Carpathians, Romania): metal distribution and partitioning of natural actinides with implications for vegetation uptake

NASA Astrophysics Data System (ADS)

Petrescu, L.; Bilal, E.

2012-04-01

Between 1962 and 2009, National Company of Uranium - CNU, the former Romanian Rare Metals Mining Company, mined over 1,200,000 tones of pitchblende ore in the East Carpathians (Crucea-Botušana area, Bistrita Mountains). The exploration and mining facilities include 32 adits, situated between 780 and 1040 m above sea level. Radioactive waste resulted from mining are disposed next to the mining facilities. Mine dumps (32) cover an area of 364,000 square meters and consist of waste rock (rocks with sub-economic mineralization) and gangue minerals. Older dumps (18) have been already naturally reclaimed by forest vegetation, which played an important role in stabilizing the waste dump cover and in slowing down the uranium migration processes. The soils samples have been collected from different mine dumps in the Crucea-Botušana uranium deposit, mainly from 1, 4, 5, 6, 8, 9, 1/30 and 950 mine waste galleries. Soil samples were collected from the upper part and slope at each mine dump, from the vegetation root zones. Total uranium concentration in soils collected from Crucea-Botušana site ranged from 6.10 to 680.70 ppm, with a mean of 52.48 ppm (dry wt.). Total thorium varies between 7.70 and 115.30 ppm (dry wt.). This indicates that the adsorption of the radioactive elements by the soils is high and variable, influenced by the ore dump - sample relationship. The sequential extraction has emphasized the fact that the uranium is associated with all the mineral fractions present in the soil samples. A great percentage of U can be found in the carbonate (21.77%), organic (15.04%) and oxides fractions (15.88%) - in accordance with the high absorbed/adsorbed properties of this element. The percentage of uranium detected in the exchangeable fraction is rather small - 2.16%. It is also to be expected that the uranium should be irreversible adsorbed by the organic matter and by the clay minerals due to its ionic radius and to its positive charge. The fact that 21.77% of the total uranium can be found in the specifically absorbed and carbonate bound fraction, indicated the important role played by the carbonates in the retention of U; one the other hand this fraction is liable to release the uranium if the pH should happen to change. Thorium appear in high-enough concentration in the soil is scarcely available because 70.29% is present in residual fraction, and about 21.78% in the crystalline iron oxides occluded fraction and organically and secondary sulfide bound fraction. This is certainly due to the fact that this naturally occurring radionuclide can be associated with relatively insoluble mineral phases like alumino-silicates and refractory oxides. Its association with the organic matter (10.93%) suggests that it can form soluble organic complexes that can facilitate its removal by the stream waters. Grounded on these results, we were able to prove that the examined mine dumps can represent an impact on the environment, which constitute an argument in favor of the initiation of a program of remedying the quality of the environment from this mining zone. Although from our research it resulted that the natural actinides does not concentrate in the exchangeable fraction (Th) or it concentrates very little in it (U), the isolation of the mineral fraction of soil rich in U and Th helps us in the future identification of the links between the bioavailability and the pedogenesis, connections which control the cycle of the radioactive metals.

Olympic Dam copper-uranium-gold deposit, South Australia

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

Lalor, J.H.

1986-07-01

The Olympic Dam copper-uranium-gold deposit was discovered in July 1975. It is located 650 km north-northwest of Adelaide on Roxby Downs Station in South Australia. The first diamond drill hole, RD1, intersected 38 m of 1.05% copper. A further eight holes were drilled with only marginal encouragement to November 1976, when RD10 cored 170 m of 2.12% copper and 0.06% of uranium oxide, thus confirming an economic discovery. The discovery of Olympic Dam is an excellent example applying broad-scale, scientifically based conceptual studies to area selection. Exploration management supported its exploration scientists in testing their ideas with stratigraphic drilling. Geologicmore » modeling, supported by geophysical interpretations and tectonic studies, was used to site the first hole. The discovery also illustrates the persistence required in mineral exploration. The deposit appears to be a new type of stratabound sediment-hosted ore. It has an areal extent exceeding 20 km/sup 2/ with vertical thicknesses of mineralization up to 350 m. It is estimated to contain more than 2000 million MT of mineralized material with an average grade of 1.6% copper, 0.06% uranium oxide, and 0.6 g/MT gold. The deposit occurs in middle Proterozoic basement beneath 350 m of unmineralized, flat upper Proterozoic sediments. The sediments comprising the local basement sequence are predominantly sedimentary breccias controlled by a northwest-trending graben.« less

Radon exhalation and radiometric prospecting on rocks associated with Cu-U mineralizations in the Singhbhum shear zone, Bihar.

PubMed

Sengupta, D; Kumar, R; Singh, A K; Prasad, R

2001-12-01

The Singhbhum thrust belt is a 200 km long arcuate orogenic belt in Bihar, eastern India. The huge mineral resources, viz. copper, uranium, magnetite, apatite and molybdenite, etc., make it significant from an economic as well as a geological point of view. The belt hosts three types of mineralization: sulphides of copper and other metals, uranium oxides and apatite-magnetite. Several distinct geological episodes are responsible for the evolution of mineralization and the thrust zone itself. Extensive and reliable radiometric prospecting and assaying have been carried out by us for the past 5 years from Dhobani in the east to Turamdih in the west of the Singhbhum shear zone. The present work indicates uranium mineralization in the Pathargora-Rakha area presently being mined for copper and also within areas in the vicinity of Bhatin. Studies on radon emanation have also been undertaken in some parts of the shear zone which indicate reasonably high radon emanation of the soils and rocks studied. This suggests the need for regular monitoring and suitable controls on the mine environment (air quality) and its vicinity. Radon emanation studies coupled with gamma-ray spectrometry and the subsequent modelling of the radiometric and radon measurements will help in the application of radon as a geophysical tracer in exploration of radioactive ore bodies and in radon risk assessment as well as in delineating active and passive faults and even in petroleum exploration.

Depositional environments and paleocurrent directions in the Precambrian Moeda Formation, Minas Gerais, Brazil

USGS Publications Warehouse

Lindsey, David A.

1975-01-01

The middle Precambrian Moeda Formation of Minas Gerais, Brazil, contains uranium and other minerals believed to be of detrital origin. Two areas of anomalously high concentrations of uranium have been discovered in conglomeratic zones that are interpreted as paleochannels. Because the distribution of uranium is believed to be controlled at least in part by sedimentation, a reconnaissance study was undertaken to assess the depositional environment and sediment dispersal pattern of the Moeda Formation.

Rates and mechanisms of uranyl oxyhydroxide mineral dissolution

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

Reinoso-Maset, Estela; Steefel, Carl I.; Um, Wooyong

Uranyl oxyhydroxide minerals are important weathering products in uranium-contaminated surface and subsurface environments that regulate dissolved uranium concentrations. However, dissolution rates for this class of minerals and associated dissolution mechanisms have not been previously reported for circumneutral pH conditions, particularly for the case of flow through porous media. In this paper, the dissolution rates of K- and Na-compreignacite (K 2(UO 2) 6O 4(OH) 6·8H 2O and Na 2(UO 2) 6O 4(OH) 6·8H 2O respectively) were measured using flow-through columns reacted with two simulated background porewater (BPW) solutions of low and high dissolved total carbonate content (ca. 0.2 and 2.8 mmolmore » L -1). Column materials were characterized before and after reaction with electron microscopy, bulk chemistry, and EXAFS to identify structural and chemical changes during dissolution and to obtain insight into molecular-scale processes. The reactive transport code CrunchFlow was used to calculate overall dissolution rates while accounting for fluid transport and changes in mineral volume and reactive surface area and results were compared to steady-state dissolution rate calculations. In low carbonate BPW systems, interlayer K and Na were initially leached from both minerals, and in Na-compreignacite, K and minor divalent cations from the input solution were incorporated into the mineral structure. Results of characterization analyses suggested that after reaction both K- and Na-compreignacite resembled a disordered K-compreignacite with altered surfaces. A 10-fold increase in dissolved carbonate concentration and corresponding increase in pH (from 6.65 to 8.40) resulted in a net removal of 58-87% of total uranium mass from the columns, compared to <1% net loss in low carbonate BPW systems. Steady-state release of dissolved uranium was not observed with high carbonate solutions and post-reaction characterizations indicated a lack of development of leached or altered surfaces. Dissolution rates (normalized to specific surface area) were about 2.5-3 orders-of-magnitude faster in high versus low carbonate BPW systems, with Na-compreignacite dissolving more rapidly than K-compreignacite under both BPW conditions, possibly due to greater ion exchange (1.57·10 -10 vs. 1.28·10 -13 mol m -2 s -1 [log R = -9.81 and -12.89] and 5.79·10 -10 vs. 3.71·10 -13 mol m -2 s -1 [log R = -9.24 and -12.43] for K- and Na-compreignacite respectively). Experimental and spectroscopic results suggest that the dissolution rate is controlled by bond breaking of a uranyl group and detachment from polyhedral layers of the mineral structure. With higher dissolved carbonate concentrations, this rate-determining step is accelerated by the formation of Ca-uranyl carbonate complexes (dominant species under these conditions), which resulted in an increase of the dissolution rates. Optimization of both dissolution rate and mineral volume fraction in the reactive transport model to account for uranium mass removal during dissolution more accurately reproduced effluent data in high carbonate systems, and resulted in faster overall rates compared with a steady-state dissolution assumption. Finally, this study highlights the importance of coupling reaction and transport processes during the quantification of mineral dissolution rates to accurately predict the fate of contaminants such as uranium in porous geomedia.« less

Rates and mechanisms of uranyl oxyhydroxide mineral dissolution

DOE PAGES

Reinoso-Maset, Estela; Steefel, Carl I.; Um, Wooyong; ...

2017-06-01

Uranyl oxyhydroxide minerals are important weathering products in uranium-contaminated surface and subsurface environments that regulate dissolved uranium concentrations. However, dissolution rates for this class of minerals and associated dissolution mechanisms have not been previously reported for circumneutral pH conditions, particularly for the case of flow through porous media. In this paper, the dissolution rates of K- and Na-compreignacite (K 2(UO 2) 6O 4(OH) 6·8H 2O and Na 2(UO 2) 6O 4(OH) 6·8H 2O respectively) were measured using flow-through columns reacted with two simulated background porewater (BPW) solutions of low and high dissolved total carbonate content (ca. 0.2 and 2.8 mmolmore » L -1). Column materials were characterized before and after reaction with electron microscopy, bulk chemistry, and EXAFS to identify structural and chemical changes during dissolution and to obtain insight into molecular-scale processes. The reactive transport code CrunchFlow was used to calculate overall dissolution rates while accounting for fluid transport and changes in mineral volume and reactive surface area and results were compared to steady-state dissolution rate calculations. In low carbonate BPW systems, interlayer K and Na were initially leached from both minerals, and in Na-compreignacite, K and minor divalent cations from the input solution were incorporated into the mineral structure. Results of characterization analyses suggested that after reaction both K- and Na-compreignacite resembled a disordered K-compreignacite with altered surfaces. A 10-fold increase in dissolved carbonate concentration and corresponding increase in pH (from 6.65 to 8.40) resulted in a net removal of 58-87% of total uranium mass from the columns, compared to <1% net loss in low carbonate BPW systems. Steady-state release of dissolved uranium was not observed with high carbonate solutions and post-reaction characterizations indicated a lack of development of leached or altered surfaces. Dissolution rates (normalized to specific surface area) were about 2.5-3 orders-of-magnitude faster in high versus low carbonate BPW systems, with Na-compreignacite dissolving more rapidly than K-compreignacite under both BPW conditions, possibly due to greater ion exchange (1.57·10 -10 vs. 1.28·10 -13 mol m -2 s -1 [log R = -9.81 and -12.89] and 5.79·10 -10 vs. 3.71·10 -13 mol m -2 s -1 [log R = -9.24 and -12.43] for K- and Na-compreignacite respectively). Experimental and spectroscopic results suggest that the dissolution rate is controlled by bond breaking of a uranyl group and detachment from polyhedral layers of the mineral structure. With higher dissolved carbonate concentrations, this rate-determining step is accelerated by the formation of Ca-uranyl carbonate complexes (dominant species under these conditions), which resulted in an increase of the dissolution rates. Optimization of both dissolution rate and mineral volume fraction in the reactive transport model to account for uranium mass removal during dissolution more accurately reproduced effluent data in high carbonate systems, and resulted in faster overall rates compared with a steady-state dissolution assumption. Finally, this study highlights the importance of coupling reaction and transport processes during the quantification of mineral dissolution rates to accurately predict the fate of contaminants such as uranium in porous geomedia.« less

Source identification of uranium-containing materials at mine legacy sites in Portugal.

PubMed

Keatley, A C; Martin, P G; Hallam, K R; Payton, O D; Awbery, R; Carvalho, F P; Oliveira, J M; Silva, L; Malta, M; Scott, T B

2018-03-01

Whilst prior nuclear forensic studies have focused on identifying signatures to distinguish between different uranium deposit types, this paper focuses on providing a scientific basis for source identification of materials from different uranium mine sites within a single region, which can then be potentially used within nuclear forensics. A number of different tools, including gamma spectrometry, alpha spectrometry, mineralogy and major and minor elemental analysis, have been utilised to determine the provenance of uranium mineral samples collected at eight mine sites, located within three different uranium provinces, in Portugal. A radiation survey was initially conducted by foot and/or unmanned aerial vehicle at each site to assist sample collection. The results from each mine site were then compared to determine if individual mine sites could be distinguished based on characteristic elemental and isotopic signatures. Gamma and alpha spectrometry were used to differentiate between samples from different sites and also give an indication of past milling and mining activities. Ore samples from the different mine sites were found to be very similar in terms of gangue and uranium mineralogy. However, rarer minerals or specific impurity elements, such as calcium and copper, did permit some separation of the sites examined. In addition, classification rates using linear discriminant analysis were comparable to those in the literature. Crown Copyright © 2018. Published by Elsevier Ltd. All rights reserved.

Distribution of trace elements in drilling chip samples around a roll-type uranium deposit, San Juan Basin, New Mexico

USGS Publications Warehouse

Day, H.C.; Spirakis, C.S.; Zech, R.S.; Kirk, A.R.

1983-01-01

Chip samples from rotary drilling in the vicinity of a roll-type uranium deposit in the southwestern San Juan Basin were split into a whole-washed fraction, a clay fraction, and a heavy mineral concentrate fraction. Analyses of these fractions determined that cutting samples could be used to identify geochemical halos associated with this ore deposit. In addition to showing a distribution of selenium, uranium, vanadium, and molybdenum similar to that described by Harshman (1974) in uranium roll-type deposits in Wyoming, South Dakota, and Texas, the chemical data indicate a previously unrecognized zinc anomaly in the clay fraction downdip of the uranium ore.

quantifying and Predicting Reactive Transport

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

Peter C. Burns, Department of Civil Engineering and Geological Sciences, University of Notre Dame

2009-12-04

This project was led by Dr. Jiamin Wan at Lawrence Berkeley National Laboratory. Peter Burns provided expertise in uranium mineralogy and in identification of uranium minerals in test materials. Dr. Wan conducted column tests regarding uranium transport at LBNL, and samples of the resulting columns were sent to Dr. Burns for analysis. Samples were analyzed for uranium mineralogy by X-ray powder diffraction and by scanning electron microscopy, and results were provided to Dr. Wan for inclusion in the modeling effort. Full details of the project can be found in Dr. Wan's final reports for the associated effort at LBNL.

Efficacy of Biostimulation for Uranium Sequestration: Coupled Effects Sediment/Groundwater Geochemistry and Microbiology

NASA Astrophysics Data System (ADS)

Xu, J.; Veeramani, H.; Qafoku, N. P.; Singh, G.; Pruden, A.; Kukkadapu, R. K.; Hochella, M. F., Jr.

2015-12-01

A systematic flow-through column study was conducted using sediments and groundwater from the subsurface at the U.S. Department of Energy's Integrated Field Research Challenge (IFRC) site in Rifle, Colorado, to better understand the efficacy of uranium removal from the groundwater with and without biostimulation in the form of acetate amendments. The interactive effects of acetate amendment, groundwater/sediment geochemistry, and intrinsic bacterial community composition were evaluated using four types of sediments, collected from different uranium-contaminated (D08, LQ107, CD) or non-contaminated (RABS) aquifers. Subtle variations in the sediments' geochemistry in terms of mineral compositions, particle sizes, redox conditions, and metal(loid) co-contaminants had a marked effect on the uranium removal efficiency, following a descending trend of D08 (~ 90 to 95%) >> RABS (~ 20 to 25) ≥ LQ107 (~ 15 to 20%) > CD (~ -10 to 0%). Overall, biostimulation of the sediments with acetate drove deeper anoxic conditions and observable shifts in bacterial population structures. The abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, were highest in the sediments that performed best in terms of uranium removal. By comparison, no obvious associations were found between the uranium removal efficiency and the abundance of typical iron-reducing microorganisms, e.g., Geobacter spp. In the sediments where bacterial biomass was relatively low and sulfate-reduction was not detected (i.e., CD), abiotic adsorption onto fine mineral surfaces such as phyllosilates likely played a dominant role in the attenuation of aqueous uranium. In these scenarios, however, acetate amendment induced significant remobilization of the sequestered uranium and other heavy metals (e.g., strontium), leading to zero or negative uranium removal efficiencies (i.e., CD). The results of this study suggest that reductive immobilization of uranium can be effectively achieved under predominantly sulfate-reducing conditions in sediment microenvironments when bioavailable iron (III) (oxyhydr)oxides are mostly depleted, and provide insight into the integrated roles of sediment geochemistry, mineralogy, and bacterial population dynamics.

SIERRA ANCHA WILDERNESS, ARIZONA.

USGS Publications Warehouse

Wrucke, Chester T.; Light, Thomas D.

1984-01-01

Mineral surveys show that the Sierra Ancha Wilderness in Arizona has demonstrated resources of uranium, asbestos, and iron; probable and substantiated resource potential for uranium, asbestos, and iron; and a probable resource potential for fluorspar. Uranium resources occur in vein and strata-bound deposits in siltstone that underlies much of the wilderness. Deposits of long-staple chrysotile asbestos are likely in parts of the wilderness adjacent to known areas of asbestos production. Magnetite deposits in the wilderness form a small iron resource. No fossil fuel resources were identified in this study.

Early Jurassic mafic dykes from the Aigao uranium ore deposit in South China: Geochronology, petrogenesis and relationship with uranium mineralization

NASA Astrophysics Data System (ADS)

Zhang, Di; Zhao, Kui-Dong; Chen, Wei; Jiang, Shao-Yong

2018-05-01

Mafic dykes are abundant and widely distributed in many granite-hosted uranium ore deposits in South China. However, their geochronology, petrogenesis and relationship with uranium mineralization were poorly constrained. In this study, apatite U-Pb dating, whole-rock major and trace element and Sr-Nd-Pb isotope analysis were conducted for the dolerite dykes from the Aigao uranium ore deposit. Apatite U-Pb isotopic data indicate that the mafic dykes were emplaced at Early Jurassic (189 ± 4 Ma), which provides new evidence for the rarely identified Early Jurassic magmatism in South China. Pyroxene from the dykes is mainly augite, and plagioclase belongs to albite. The dolerite samples have relatively low SiO2 contents (45.33-46.79 wt%), relatively high total alkali contents (K2O + Na2O = 4.11-4.58 wt%) and Al2O3 contents (13.39-13.80 wt%), and medium MgO contents (4.29-5.16 wt%). They are enriched in Nb, Ta, Ti, rare earth elements and depleted in Rb, K, Sr, Th, showing the typical OIB-like geochemical affinity. All the dolerite samples show homogeneous Sr-Nd-Pb isotopic compositions, with (87Sr/86Sr)i varying from 0.706049 to 0.707137, εNd(t) from +4.6 to +5.2, 206Pb/204Pb from 19.032 to 19.126 and 207Pb/204Pb from 15.641 to 15.653. The mafic dykes in the Aigao deposit should be derived from the partial melting of the asthenospheric mantle and formed in a within-plate extensional environment. The emplacement age of the mafic dykes is older than the uranium mineralization age. Therefore, CO2 in ore-forming fluids couldn't originate from the basaltic magma as suggested by previous studies. The dolerite dykes might only provide a favorable reducing environment to promote the precipitation of uraninite from oxidize hydrothermal fluids.

Petrography and geochemistry of granitoids from the Samphire Pluton, South Australia: Implications for uranium mineralisation in overlying sediments

NASA Astrophysics Data System (ADS)

Domnick, Urs; Cook, Nigel J.; Bluck, Russel; Brown, Callan; Ciobanu, Cristiana L.

2018-02-01

The Blackbush uranium deposit (JORC Inferred Resource: 12,580 tonnes U), located on the north-eastern Eyre Peninsula, is currently the only sediment-hosted U deposit investigated in detail in the Gawler Craton. Uranium is hosted within Eocene sandstone of the Kanaka Beds, overlying Mesoproterozoic granites of the Samphire pluton, affiliated with the Hiltaba Intrusive Suite ( 1.6 Ga). These are considered the most probable source rocks for uranium mineralisation. By constraining the petrography and mineralogy of the granites, insights into the post-emplacement evolution can be gained, which may provide an exploration indicator for other sediment-hosted uranium systems. Three geochemically distinct granite types were identified in the Samphire Pluton and correspond to domains interpreted from geophysical data. All granites show complex alteration overprints and textures with increasing intensity closer to the deposit, as well as crosscutting veining. Alkali feldspar has been replaced by porous K-feldspar and albite, and plagioclase is overprinted by an assemblage of porous albite + sericite ± calc-silicates (prehnite, pumpellyite and epidote). This style of feldspar alteration is regionally widespread and known from Hiltaba-aged granites associated with iron-oxide copper-gold mineralisation at Olympic Dam and in the Moonta-Wallaroo region. In two granite types biotite is replaced by calcic garnet. Calc-silicates are indicative of Ca-metasomatism, sourced from the anorthite component of altered plagioclase. Minor clay alteration of feldspars is present in all samples. Mineral assemblages in veins include quartz + hematite, hematite + coffinite, fluorite + quartz, and clay minerals. Minor chlorite and sericite are found in all vein types. All granite types are anomalously rich in U (concentrations between 10 and 81 ppm). Highly variable Th/U ratios, as well as hydrothermal U minerals (mostly coffinite) in granites and veins, are clear evidence for U mobility. Uranium may have been preconcentrated in veins in the upper parts of the pluton, and was subsequently leached after deposition of the sediment.

National Uranium Resource Evaluation: Marfa Quadrangle, Texas

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

Henry, C D; Duex, T W; Wilbert, W P

1982-09-01

The uranium favorability of the Marfa 1/sup 0/ by 2/sup 0/ Quadrangle, Texas, was evaluated in accordance with criteria established for the National Uranium Resource Evaluation. Surface and subsurface studies, to a 1500 m (5000 ft) depth, and chemical, petrologic, hydrogeochemical, and airborne radiometric data were employed. The entire quadrangle is in the Basin and Range Province and is characterized by Tertiary silicic volcanic rocks overlying mainly Cretaceous carbonate rocks and sandstones. Strand-plain sandstones of the Upper Cretaceous San Carlos Formation and El Picacho Formation possess many favorable characteristics and are tentatively judged as favorable for sandstone-type deposits. The Tertiarymore » Buckshot Ignimbrite contains uranium mineralization at the Mammoth Mine. This deposit may be an example of the hydroauthigenic class; alternatively, it may have formed by reduction of uranium-bearing ground water produced during diagenesis of tuffaceous sediments of the Vieja Group. Although the presence of the deposit indicates favorability, the uncertainty in the process that formed the mineralization makes delineation of a favorable environment or area difficult. The Allen intrusions are favorable for authigenic deposits. Basin fill in several bolsons possesses characteristics that suggest favorability but which are classified as unevaluated because of insufficient data. All Precambrian, Paleozoic, other Mesozoic, and other Cenozoic environments are unfavorable.« less

Chemical and Sr isotopic characterization of North America uranium ores: Nuclear forensic applications

DOE PAGES

Balboni, Enrica; Jones, Nina; Spano, Tyler; ...

2016-08-31

This study reports major, minor, and trace element data and Sr isotope ratios for 11 uranium ore (uraninite, UO 2+x) samples and one processed uranium ore concentrate (UOC) from various U.S. deposits. The uraninite investigated represent ores formed via different modes of mineralization (e.g., high- and low-temperature) and within various geological contexts, which include magmatic pegmatites, metamorphic rocks, sandstone-hosted, and roll front deposits. In situ trace element data obtained by laser ablation-ICP-MS and bulk sample Sr isotopic ratios for uraninite samples investigated here indicate distinct signatures that are highly dependent on the mode of mineralization and host rock geology. Relativemore » to their high-temperature counterparts, low-temperature uranium ores record high U/Th ratios (>1000), low total rare earth element (REE) abundances (<1 wt%), high contents (>300 ppm) of first row transition metals (Sc, Ti, V, Cr, Mn, Co, Ni), and radiogenic 87Sr/ 86Sr ratios (>0.7200). Comparison of chondrite normalized REE patterns between uraninite and corresponding processed UOC from the same locality indicates identical patterns at different absolute concentrations. Lastly, this result ultimately confirms the importance of establishing geochemical signatures of raw, uranium ore materials for attribution purposes in the forensic analysis of intercepted nuclear materials.« less

Chemical and Sr isotopic characterization of North America uranium ores: Nuclear forensic applications

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

Balboni, Enrica; Jones, Nina; Spano, Tyler

This study reports major, minor, and trace element data and Sr isotope ratios for 11 uranium ore (uraninite, UO 2+x) samples and one processed uranium ore concentrate (UOC) from various U.S. deposits. The uraninite investigated represent ores formed via different modes of mineralization (e.g., high- and low-temperature) and within various geological contexts, which include magmatic pegmatites, metamorphic rocks, sandstone-hosted, and roll front deposits. In situ trace element data obtained by laser ablation-ICP-MS and bulk sample Sr isotopic ratios for uraninite samples investigated here indicate distinct signatures that are highly dependent on the mode of mineralization and host rock geology. Relativemore » to their high-temperature counterparts, low-temperature uranium ores record high U/Th ratios (>1000), low total rare earth element (REE) abundances (<1 wt%), high contents (>300 ppm) of first row transition metals (Sc, Ti, V, Cr, Mn, Co, Ni), and radiogenic 87Sr/ 86Sr ratios (>0.7200). Comparison of chondrite normalized REE patterns between uraninite and corresponding processed UOC from the same locality indicates identical patterns at different absolute concentrations. Lastly, this result ultimately confirms the importance of establishing geochemical signatures of raw, uranium ore materials for attribution purposes in the forensic analysis of intercepted nuclear materials.« less

Uranium deposits of the northern part of the Boulder Batholith, Montana

USGS Publications Warehouse

Becraft, George E.

1955-01-01

Uranium minerals and radioactivity anomalies occur in many silver-lead veins and chalcedony veins and vein zones in the Boulder batholith of southwestern Montanao Pitchblende has been identified in a few silver-lead veins. These veins occupy shear zones along which there is no evidence of large-scale lateral displacement. The wall rock adjacent to the veins is intensely silicified and sencitized quartz monzonite and granodiortte. The veins have yielded substantial quantities of lead, silver, zinc, and gold. The silver-lead veins consist principal1y of galena, spha1erite, tetrahedrite, cha1copyrite and pyrite in a gangue of light to dark gray quartz, altered rock, gouge, and subordinate chalcedony and carbonate minerals. No anomalous radioactivity nor uranium minerals have been found in similar veins in pre-batholithic rocks of the area. Chalcedony veins and vein zones, some of which are ttraniferous, are distinctly different from the silver-lead veins and, with a single except1on, are known only in the batholith. The chalcedony vein zones consist of one or more discontinuous stringers or veins of cha1cedony and microcrystalline quartz in silicified and sericitized quartz monzonite and granodiorite, and in less strongly altered alaskite. On1y small amounts of silver ore have been produced from these chalcedony veins and vein zones. All of the veins are ear1y Tertiary in age, but the silver-lead veins probably are older than the chalcedony veins. Uranium is closely associated with chalcedory and microcrystalline quartz in both types of veins. This association suggests that all of the uranium in the area is of the same age. If so, some of the silver-lead veins must have been reopened during the period of chalcedony vein formation.

Preliminary summary review of thorium-bearing mineral occurrences in Alaska

USGS Publications Warehouse

Bates, Robert G.; Wedow, Helmuth

1952-01-01

Thorium-bearing minerals are known at 47 localities in Alaska. At these localities the thorium occurs as a major constituent or in minor amounts as an impurity in one or more of the following 12 minerals: allanite, columbite, ellsworthite, eschynite, gummite, monazite, orangite, parisite, thorianite, thorite, xenotime, and zircon. In addition other minerals, such as biotite and sphene, are radioactive and may contain thorium. Several unidentified columbate minerals with uranium or thorium and uranium as major constituents have been recognized at some localities. The distribution, by type of deposit, of the 57 thorium occurrences is as follows: lode - 3, lode and placer - 1, granitic rock - 3, granitic rock and related placer - 14, and placer - 26. Of the four lode occurrences only the radioactive veins at Salmon Bay in southeastern Alaska and the contact metamorphic deposit in the Nixon Fork area of central Alaska warrant further consideration, although insufficient data are available to determine whether these two deposits have commercial possibilities. The remaining occurrences of thorium-bearing minerals in Alaska are limited to placer deposits and disseminations of accessory minerals in granitic rocks. In most of these occurrences the thorium-bearing minerals occur in only trace amounts and consequently warrent little further consideration. More data are needed to determine the possibilities of byproduct recovery of thorium-bearing minerals from several of the gold and tin placers.

PRIMARY MINERALIZATION OF URANIUM-BEARING "SILICEOUS REEF" VEINS IN THE BOULDER BATHOLITH, MONTANA. PART I. THE HOST ROCKS

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

Wright, H.D.; Bieler, B.H.

1960-01-01

Between 1952 and 1956 a study was made of some of the uranium-bearing hydrothermal veins in the northern part of the Boulder batholith, Montana. Three mines, the W. Wilson, G. Washington, and Free Enterprise, were investigated in detail. The veins are characterized by a microcrystalline quartz gangue containing sparsely scattered, very fine-grained sulfide minerals and uraninite. Above the present water table, secondary uranium minerals are abundant locally. Throughout the area the veins --called "siliceous reefs"--strike east to northeast, are of steep dip, and vary in thickness from a fraction of an inch to several feet. The country rock is granodioritemore » containing, in order of abundance, plagioclase (An/sub 30/ to An/sub 36/), quartz, orthoclase, biotite, and hornblende, with apatite, zircon, and sphene. Small bodies of aplite, pegmatite, and alaskite occur along some veins. The granodiorite adjacent to the veins is rather strongly altered. The alteration is similar throughout all of the deposits studied, in barren and orebearing portions alike. The essential minerals show a characteristic sequence of alteration, in the order hornblende, andesine, biotite, orthoclase, and quartz. Successive zones of alteration are characterized, from the vein outward, by maximum development of sericite (muscovite polytype 1M, in part), kaolinite, and montmorillonite. Other alteration products are quartz, pyrite, calcite, leucoxene, and chlorite. The alteration resulted in an increase in silica and ferric iron, a decrease in alumina, total iron, ferrous iron, lime, soda, and magnesia, and little change in potash, titania, phosphorus, carbon dioxide, and sulfur. Consideration of the stability fields of the sheet structure silicate minerals indicates little basis for interpretation of the temperatures prevailing during mineralization. (auth)« less

Uranium miner lung cancer study. Progress report for period, July 1, 1977--July 1 1978

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

Saccomanno, G.

1978-09-15

This study was initiated in 1957 by the U.S. Public Health, and many facets of this project are reaching final objectives. Many new studies have developed in the course of this study and will continue. The projects supported by The Department of Energy during the past year are of utmost importance and consist of: (a) collection of material from uranium miners known to have cancer of the lung into a tumor registry; (b) completion and publication of the Manual on Pulmonary Cytology; (c) regression study of sputum cytological findings in uranium miners who showed marked atypical squamous cell metaplasia andmore » have quit smoking cigarettes, mining, or both; (d) continuation of sputum collection and collection of lungs from deceased miners; (e) sensory development for localization of carcinoma in situ of the lung; and (f) lung histology program. Since we have examined approximately 80,000 sputum samples the last 21 years in cases that showed normal cytology at the inception of the study and some subsequently developed carcinoma of the lung, we have an accumulation of material that is worthy of study and presentation. In addition, we continue to add new knowledge to the art of diagnostic pulmonary cytology. This is a relatively new field, and our contributions resulting from these studies have added much to this new diagnostic tool.« less

Occupational and diagnostic exposure to ionizing radiation and leukemia risk among German uranium miners.

PubMed

Möhner, Matthias; Gellissen, Johannes; Marsh, James W; Gregoratto, Demetrio

2010-09-01

Lung cancer is a well-known effect of radon exposure in uranium mines. However, little is known about the induction of leukemia by radiation exposure in mines. Moreover, miners usually have occupational medical checkup programs that include chest x-ray examinations. Therefore, the aim of the present study was to re-examine leukemia risk among miners, taking into account exposure to x rays for diagnostic purposes. The data used were from a previously analyzed individually matched case-control study of former uranium miners in East Germany with 377 cases and 980 controls. Additionally, data on x-ray examinations were taken from medical records for most of the subjects. Finally, the absorbed dose to red bone marrow was calculated considering both occupational and diagnostic exposures. Using conditional logistic regression models, a moderately but not statistically significant elevated risk was seen in the dose category above 200 mGy for the combined dose from both sources [odds ratio (OR) = 1.33, 90% confidence interval (CI): (0.82-2.14)]. Ignoring the dose accumulated in the recent 20 y, the risk in the highest dose category (>105 mGy) was higher [OR = 1.77, 90% CI: (1.06-2.95)]. Ignoring diagnostic exposure yielded similar results. For the highest dose category (absorbed dose lagged by 20 y) the risk was more than doubled [OR = 2.64, 90% CI: (1.60-4.35)].

Determination of uranium isotopes in environmental samples by anion exchange in sulfuric and hydrochloric acid media.

PubMed

Popov, L

2016-09-01

Method for determination of uranium isotopes in various environmental samples is presented. The major advantages of the method are the low cost of the analysis, high radiochemical yields and good decontamination factors from the matrix elements, natural and man-made radionuclides. The separation and purification of uranium is attained by adsorption with strong base anion exchange resin in sulfuric and hydrochloric acid media. Uranium is electrodeposited on a stainless steel disk and measured by alpha spectrometry. The analytical method has been applied for the determination of concentrations of uranium isotopes in mineral, spring and tap waters from Bulgaria. The analytical quality was checked by analyzing reference materials. Copyright © 2016 Elsevier Ltd. All rights reserved.

Origin of coffinite in sedimentary rocks by a sequential adsorption-reduction mechanism.

USGS Publications Warehouse

Goldhaber, M.B.; Hemingway, B.S.; Mohagheghi, A.; Reynolds, R.L.; Northrop, H.R.

1987-01-01

Coffinite is the dominant ore mineral in the V-U ores of the Tony-M mine in the Henry Mts mineral belt of the Colorado Plateau. This orebody was formed at a density-stratified solution interface between uranyl-ion-bearing meteoric water and a saline fluid which was locally reducing. The localization of U at this solution interface occurred by adsorption onto the surfaces of detrital minerals, this adsorption being related to the pH difference between the two fluids. Experimental evidence is presented showing that the adsorption facilitated the reduction of uranium to U(IV). This adsorbed, reduced uranium bonded with aqueous silica in the ore zone to form coffinite. The high concentration of silica (as a monomeric species) in the ore-forming solution stabilized coffinite in preference to uraninite.-R.A.H.

[The characteristics of type I, III collagen and LN in pulmonary fibrosis induced by uranium ore dust in rats].

PubMed

Hu, Ying-chun; Luo, Zhen-hua; Yuan, Xing-jiang; Yang, Li-ping; Wang, Shou-feng; Li, Guang-yue; He, Xing-peng

2011-02-01

To explore the characteristics of LN and type I, III collagen in pulmonary fibrosis induced by uranium ore dust in rats. 60 adult Wistar rats were divided randomly into two groups, control group (30 rats) and uranium ore dust group (30 rats). Non-exposed intratracheal instillation method was used. Uranium ore dust group was exposed 20 mg/ml uranium ore dust suspension 1ml per rat, meanwhile control group was exposed normal saline 1ml per rat. Post-exposed the 7, 14, 21, 30 and 60 d, 6 rats in each group were killed randomly, lung tissue were collected. The pathological changes in lung tissue were observed by microscope using HE staining, the collagen I and III in lungs were observed by polarizing microscope using Biebrich scarlet staining. The expression of LN protein in lung tissue was observed by immunohistochemistry-SP. During lung fibrosis, a large amount of the proliferated I and III collagen in lungs were observed. Post-exposure to uranium ore dust, the characteristics in proliferated collagen in lungs were type I collagen deposited in lung interstitium mainly in the early stage. The area percentage of collagen I and III was increased significantly at 7, 14, 21, 30 and 60d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). The over expression of LN in the lung tissue were observed. The expression of LN was distributed in the lung tissue as thickening of the linear or cluster. The integral optical density of LN was increased significantly at 21, 30 and 60 d in the experimental group as compared with that in the control group (P < 0.05 or P < 0.01). After exposure to uranium ore dust, the characteristics in proliferated collagen in lungs are the type of I collagen deposited in lung interstitium mainly in the early stage, while the type of III collagen increase significantly at the later period. The overexpression of LN exists in the process of pulmonary fibrosis. It suggests that LN has a role effect in the process of pulmonary fibrosis.

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.

Natural thorium resources and recovery: Options and impacts

USGS Publications Warehouse

Ault, Timothy; Van Gosen, Bradley S.; Krahn, Steven; Croff, Allen

2016-01-01

This paper reviews the front end of the thorium fuel cycle, including the extent and variety of thorium deposits, the potential sources of thorium production, and the physical and chemical technologies required to isolate and purify thorium. Thorium is frequently found within rare earth element–bearing minerals that exist in diverse types of mineral deposits, often in conjunction with other minerals mined for their commercial value. It may be possible to recover substantial quantities of thorium as a by-product from active titanium, uranium, tin, iron, and rare earth mines. Incremental physical and chemical processing is required to obtain a purified thorium product from thorium minerals, but documented experience with these processes is extensive, and incorporating thorium recovery should not be overly challenging. The anticipated environmental impacts of by-product thorium recovery are small relative to those of uranium recovery since existing mining infrastructure utilization avoids the opening and operation of new mines and thorium recovery removes radionuclides from the mining tailings.

Elevated Uranium in Aquifers of the Jacobsville Sandstone

NASA Astrophysics Data System (ADS)

Sherman, H.; Gierke, J.

2003-12-01

The EPA has announced a new standard for uranium in drinking water of 30 parts per billion (ppb). This maximum contaminant level (MCL) takes effect for community water supplies December 2003. The EPA's ruling has heightened awareness among residential well owners that uranium in drinking water may increase the risk of kidney disease and cancer and has created a need for a quantified, scientific understanding of the occurrence and distribution of uranium isotopes in aquifers. The authors are investigating the occurrence of elevated uranium in northern Michigan aquifers of the Middle Proterozoic Jacobsville sandstone, a red to mottled sequence of sandstones, conglomerates, siltstones and shales deposited as basin fill in the 1.1 Ga Midcontinent rift. Approximately 25% of 300 well water samples tested for isotopic uranium have concentrations above the MCL. Elevated uranium occurrences are distributed throughout the Jacobsville sandstone aquifers stretching across Michigan's Upper Peninsula. However, there is significant variation in well water uranium concentrations (from 0.01 to 190 ppb) and neighboring wells do not necessarily have similar concentrations. The authors are investigating hydrogeologic controls on ground water uranium concentrations in the Jacobsville sandstone, e.g. variations in lithology, mineralogy, groundwater residence time and geochemistry. Approximately 2000' of Jacobsville core from the Amoco St. Amour well was examined in conjunction with the spectral gamma ray log run in the borehole. Spikes in equivalent uranium (eU) concentration from the log are frequently associated with clay and heavy mineral layers in the sandstone core. The lithology and mineralogy of these layers will be determined by analysis of thin sections and x-ray diffraction. A portable spectrometer, model GRS-2000/BL, will be used on the sandstone cliffs along Lake Superior to characterize depositional and lithologic facies of the Jacobsville sandstone in terms of concentrations and ratios of eU, eTh and K. Equipped with borehole accessories, the spectrometer will be used to log residential drinking wells to determine a relationship between the uranium concentration of well water and the eU concentration in the sandstone. Tritium/helium-3 dating will be used to determine whether ground water uranium concentrations increase with residence time. PHREEQCI will be used to model dominate aqueous species of uranium and saturation indices of uranium minerals.

75 FR 71668 - Cibota National Forest, Mount Taylor Ranger District, NM, Roca Honda Mine

Federal Register 2010, 2011, 2012, 2013, 2014

2010-11-24

... develop and conduct underground uranium mining operations on their mining claims on and near Jesus Mesa in... open to mineral entry under the General Mining Law of 1872. Section 16 is State of New Mexico land... statement (EIS) to assess the development of a uranium mining operation on the Mount Taylor Ranger District...

Micro-PIXE characterisation of uranium occurrence in the coal zones and the mudstones of the Springbok Flats Basin, South Africa

NASA Astrophysics Data System (ADS)

Nxumalo, V.; Kramers, J.; Mongwaketsi, N.; Przybyłowicz, W. J.

2017-08-01

Uranium occurrence and characterisation in the coal samples of the upper coal zones of the Vryheid Formation and mudstones of the Volksrust Formation was investigated using micro-PIXE (Proton-Induced X-ray Emission) and proton backscattering spectrometry (BS) in conjunction with the nuclear microprobe. Two styles of uranium mineralisation in the Springbok Flats Basin were found: syngenetic mineralisation in which uranium occurs organically bound with coal matrix, with no discrete uranium minerals formed, and epigenetic mineralisation in which uranium occurs in veins that are filled with coffinite with botryoidal texture in the mudstones of the Volksrust Formation, overlying the coal zones. Micro-PIXE analysis made it possible to map out trace elements (including uranium) associated with the coals at low levels of detection, which other techniques such as SEM-EDS and ore microscopy failed. This information will help in better understanding of the best extraction methods to be employed to recover uranium from the coals of the Springbok Flats Basin.

Nanoscale Zirconium-(oxyhydr)oxide in Contaminated Sediments From Hanford, WA - A New Host for Uranium

NASA Astrophysics Data System (ADS)

Stubbs, J. E.; Elbert, D. C.; Veblen, L. A.; Zachara, J. M.; Davis, J. A.; Veblen, D. R.

2008-12-01

Zirconium-, uranium-, and copper-bearing wastes have leached from former disposal ponds into vadose zone sediments in the 300 Area at the Department of Energy's Hanford Site. Zirconium is enriched in the shallow portion of the vadose zone, and we have discovered an amorphous Zr-(oxyhydr)oxide that contains 16% of the total uranium budget (84.24 ppm) in one of the shallow samples. We have characterized the oxide using electron microprobe analysis (EMPA), a focused ion beam (FIB) instrument, and transmission electron microscopy (TEM). It occurs in fine-grained coatings found on lithic and mineral fragments in these sediments. The oxide is intimately intergrown with the phyllosilicates and other minerals of the coatings, and in places can be seen coating individual, nano-sized phyllosilicate mineral grains. Electron energy-loss spectroscopy (EELS) shows that the Zr-(oxyhydr)oxide has a P:Zr atomic ratio around 0.2, suggesting it is either intergrown with minor amounts of a Zr-phosphate or has adsorbed a significant amount of phosphate. This material has adsorbed or incorporated a substantial amount of uranium. Thus, understanding its nature is critical to predicting the long-term fate of U in the Hanford vadose zone. While the low-temperature uptake of U by Zr-(oxhydr)oxides and phosphates has been studied for several decades in laboratory settings, to our knowledge ours is the first report of such uptake in the field.

TECHNICAL REPORT ON TECHNOLOGICALLY ENHANCED NATURALLY OCCURRING RADIOACTIVE MATERIALS FROM URANIUM MINING, VOLUME II: INVESTIGATION OF POTENTIAL HEALTH, GEOGRAPHIC, AND ENVIRONMENTAL ISSUES OF ABANDONED URANIUM MINES

EPA Science Inventory

Volume II investigates the potential radiogenic risks from abandoned uranium mines and evaluates which may pose the greatest hazards to members of the public and to the environment. The intent of this report is to identify who may be most likely to be exposed to wastes at small a...

Mining Agreements with Indian Tribes

ERIC Educational Resources Information Center

Luebben, Tom

1976-01-01

The article discusses aspects of negotiating agreements for exploration, development, and mining of hard minerals on Indian Reservations. The agreements discussed are typical of copper agreements, but the general points under discussion are applicable to most hard minerals except for uranium, coal, and oil which are substantially different.…

Radioactive minerals - Multimedias strategies for their divulgation

NASA Astrophysics Data System (ADS)

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

2014-05-01

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

Application of the two-stage clonal expansion model in characterizing the joint effect of exposure to two carcinogens

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

Zielinski, J.M.; Krewski, D.

1992-12-31

In this paper, we describe application of the two-stage clonal expansion model to characterize the joint effect of exposure to two carcinogens. This biologically based model of carcinogenesis provides a useful framework for the quantitative description of carcinogenic risks and for defining agents that act as initiators, promoters, and completers. Depending on the mechanism of action, the agent-specific relative risk following exposure to two carcinogens can be additive, multiplicative, or supramultiplicative, with supra-additive relative risk indicating a synergistic effect between the two agents. Maximum-likelihood methods for fitting the two-stage clonal expansion model with intermittent exposure to two carcinogens are describedmore » and illustrated, using data on lung-cancer mortality among Colorado uranium miners exposed to both radon and tobacco smoke.« less

Pena blanca natural analogue project: summary of activities

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

Levy, Schon S; Goldstein, Steven J; Abdel - Fattah, Amr I

2010-12-08

The inactive Nopal I uranium mine in silicic tuff north of Chihuahua City, Chihuahua, Mexico, was studied as a natural analogue for an underground nuclear-waste repository in the unsaturated zone. Site stratigraphy was confirmed from new drill core. Datafrom site studies include chemical and isotopic compositions of saturated- and unsaturated-zone waters. A partial geochronology of uranium enrichment and mineralization was established. Evidence pertinent to uranium-series transport in the soil zone and changing redox conditions was collected. The investigations contributed to preliminary, scoping-level performance assessment modeling.

Mineral resource potential map of the Pyramid Roadless Area, El Dorado County, Colorado

USGS Publications Warehouse

Armstrong, Augustus K.; Chaffee, Maurice A.; Scott, Douglas F.

1983-01-01

Studies show., there is low potential for small deposits of gold, silver, and base metals in the Pyramid Roadless Area. There are two uranium claims (Cliff Ridge mining claims) located within the roadless area, but samples from this site showed no uranium. There are no indications of geothermal resources, coal, oil, or gas.

Identifying anthropogenic uranium compounds using soft X-ray near-edge absorption spectroscopy

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

Ward, Jesse D.; Bowden, Mark; Tom Resch, C.

2017-01-01

Uranium ores mined for industrial use are typically acid-leached to produce yellowcake and then converted into uranium halides for enrichment and purification. These anthropogenic chemical forms of uranium are distinct from their mineral counterparts. The purpose of this study is to use soft X-ray absorption spectroscopy to characterize several common anthropogenic uranium compounds important to the nuclear fuel cycle. Non-destructive chemical analyses of these compounds is important for process and environmental monitoring and X-ray absorption techniques have several advantages in this regard, including element-specificity, chemical sensitivity, and high spectral resolution. Oxygen K-edge spectra were collected for uranyl nitrate, uranyl fluoride,more » and uranyl chloride, and fluorine K-edge spectra were collected for uranyl fluoride and uranium tetrafluoride. Interpretation of the data is aided by comparisons to calculated spectra. These compounds have unique spectral signatures that can be used to identify unknown samples.« less

RECOVERY OF URANIUM AND THORIUM FROM AQUEOUS SOLUTIONS

DOEpatents

Calkins, G.D.

1958-06-10

>A process is described for the recovery of uranium and thorium from monazite sand, which is frequently processed by treating it with a hot sodium hydroxide solution whereby a precipitate forms consisting mainly of oxides or hydroxides of the rare earths, thorium and uranium. The precipitate is dissolved in mineral acid, and the acid solution is then neutralized to a pH value of between 5.2 and 6.2 whereby both the uranium and thorium precipitate as the hydroxides, while substantially all the rare earth metal values present remain in the solution. The uranium and thoriunn can then be separated by dissolving the precipitate in a solution containing a mixture of alkali carbonate and alkali bicarbonate: and contacting the carbonate solution with a strong-base anion exchange resin whereby the uranium values are adsorbed on the resin while the thorium remains in solution.

Uranium Mining and Norm in North America-Some Perspectives on Occupational Radiation Exposure.

PubMed

Brown, Steven H; Chambers, Douglas B

2017-07-01

All soils and rocks contain naturally occurring radioactive materials (NORM). Many ores and raw materials contain relatively elevated levels of natural radionuclides, and processing such materials can further increase the concentrations of naturally occurring radionuclides. In the U.S., these materials are sometimes referred to as technologically-enhanced naturally occurring radioactive materials (TENORM). Examples of NORM minerals include uranium ores, monazite (a source of rare earth minerals), and phosphate rock used to produce phosphate fertilizer. The processing of these materials has the potential to result in above-background radiation exposure to workers. Following a brief review of the sources and potential for worker exposure from NORM in these varied industries, this paper will then present an overview of uranium mining and recovery in North America, including discussion on the mining methods currently being used for both conventional (underground, open pit) and in situ leach (ISL), also referred to as In Situ Recovery (ISR), and the production of NORM materials and wastes associated with these uranium recovery methods. The radiological composition of the NORM products and wastes produced and recent data on radiological exposures received by workers in the North American uranium recovery industry are then described. The paper also identifies the responsible government agencies in the U.S. and Canada assigned the authority to regulate and control occupational exposure from these NORM materials.

Uranium resources in the Silver Reef (Harrisburg) district, Washington County, Utah

USGS Publications Warehouse

Stugard, Frederick

1951-01-01

The Silver Reef district is near Leeds, about 16 miles north of St. George, Utah. The major structural feature of the district is the Virgin anticline, a fold extending southwestward toward St. George. The anticline has been breached by erosion, and sandstone hogbacks or 'reefs' are carved from the Shinarump conglomerate mud sandstone members of the Chinle formation, both of Triassic age. Thirteen occurrences of uranium-vanadium minerals, all within the Tecumseh sandstone, which is the upper part of the Silver Reef sandstone member of the Chinle formation, have been examined over an area about 1.75 miles wide and 3 miles long. Two shipments of uranium-vanadium ore have been produced from the Chloride Chief and Silver Point claims. Samples from the deposits contain as much as 0.94 percent U3O8. The ore contains several times as much vanadium oxide as uranium, some copper, and traces of silver. It occurs in thinly bedded cross-bedded shales and sandstones within the fluviatile Tecumseh sandstone member of the Chinle formation. The ore beds are lenticular and are localized 2 near the base, center, and top of this sandstone member. The uranium-vanadium ore contains several yellow and green minerals not yet identified; the occurrences are similar to, but not associated with, the cerargyrite ore that made the district famous from 1879 to 1909.

Biogeochemical study of termite mounds: a case study from Tummalapalle area of Andhra Pradesh, India.

PubMed

Arveti, Nagaraju; Reginald, S; Kumar, K Sunil; Harinath, V; Sreedhar, Y

2012-04-01

Termite mounds are abundant components of Tummalapalle area of uranium mineralization of Cuddapah District of Andhra Pradesh, India. The systematic research has been carried out on the application of termite mound sampling to mineral exploration in this region. The distribution of chemical elements Cu, Pb, Zn, Ni, Co, Cr, Li, Rb, Sr, Ba, and U were studied both in termite soils and adjacent surface soils. Uranium accumulations were noticed in seven termite mounds ranging from 10 to 36 ppm. A biogeochemical parameter called "Biological Absorption Coefficient" of the termite mounds indicated the termite affected soils contained huge amounts of chemical elements than the adjacent soils.

Mineral resources of the Scorpion Wilderness study area, Garfield and Kane counties, Utah

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

Bartsch-Winkler, S.; Jones, J.L.; Kilburn, J.E.

1989-01-01

This paper reports on the Scorpion Wilderness Study Area which covers 14,978 acres in south- central Utah in Garfield and Kane counties. No mining claims or oil and gas leases or lease applications extend inside this study-area boundary. Demonstrated subeconomic resources of less than 30,000 tons of gypsum are in this study area. The mineral resource potential is low for undiscovered gypsum in the Carmel Formation, for undiscovered uranium in the Chinle Formation in the subsurface, and for undiscovered metals other than uranium. The energy resource potential is low for geothermal resources and is moderate for oil, gas, and carbonmore » dioxide.« less

MULTIPLE EPISODES OF IGNEOUS ACTIVITY, MINERALIZATION, AND ALTERATION IN THE WESTERN TUSHAR MOUNTAINS, UTAH.

USGS Publications Warehouse

Cunningham, Charles G.; Steven, Thomas A.; Campbell, David L.; Naeser, Charles W.; Pitkin, James A.; Duval, Joseph S.

1984-01-01

The report outlines the complex history of igneous activity and associated alteration and mineralization in the western Tushar Mountains, Utah and pointss out implciations for minerals exploration. The area has been subjected to recurrent episodes of igneous intrusion, hydrothermal alteration, and mineralization, and the mineral-resource potential of the different mineralized areas is directly related to local geologic history. The mineral commodities to be expected vary from one hydrothermal system to another, and from one depth to another within any given system. Uranium and molybdenum seem likely to have the greatest economic potential, although significant concentrations of gold may also exist.

Uranium in bone: metabolic and autoradiographic studies in the rat.

PubMed

Priest, N D; Howells, G R; Green, D; Haines, J W

1982-03-01

The distribution and retention of intravenously injected hexavalent uranium-233 in the skeleton of the female rat has been investigated using a variety of autoradiographic and radiochemical techniques. These showed that approximately one third of the injected uranium is deposited in the skeleton where it is retained with an initial biological half-time of approximately 40 days. The studies also showed that: 1 Uranium is initially deposited onto all types of bone surface, but preferentially onto those that are accreting. 2 Uranium is deposited in the calcifying zones of skeletal cartilage. 3 Bone accretion results in the burial of surface deposits of uranium. 4 Bone resorption causes the removal of uranium from surfaces. 5 Resorbed uranium is not retained by osteoclasts and macrophages in the bone marrow. 6 Uranium removed from bone surfaces enters the bloodstream where most is either redeposited in bone or excreted via the kidneys. 7 The recycling of resorbed uranium within the skeleton tends to produce a uniform level of uranium contamination throughout mineralized bone. These results are taken to indicate that uranium deposition in bone shares characteristics in common with both the 'volume-seeking radionuclides' typified by the alkaline earth elements and with the 'bone surface-seeking radionuclides' typified by plutonium.

Chemical aspects of uranium behavior in soils: A review

NASA Astrophysics Data System (ADS)

Vodyanitskii, Yu. N.

2011-08-01

Uranium has varying degrees of oxidation (+4 and +6) and is responsive to changes in the redox potential of the environment. It is deposited at the reduction barrier with the participation of biota and at the sorption barrier under oxidative conditions. Iron (hydr)oxides are the strongest sorbents of uranium. Uranium, being an element of medium biological absorption, can accumulate (relative to thorium) in the humus horizons of some soils. The high content of uranium in uncontaminated soils is most frequently inherited from the parent rocks in the regions of positive U anomalies: in the soils developed on oil shales and in the marginal zone of bogs at the reduction barrier. The development of nuclear and coal-fired power engineering resulted in the environmental contamination with uranium. The immobilization of anthropogenic uranium at artificial geochemical barriers is based on two preconditions: the stimulation of on-site metal-reducing bacteria or the introduction of strong mineral reducers, e.g., Fe at low degrees of oxidation.

Hydrogeochemical and stream sediment reconnaissance basic data for Waco NTMS quadrangle, Texas

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

Not Available

1981-07-31

Results of a reconnaissance geochemical survey of the Waco Quadrangle are reported. Field and laboratory data are presented for 218 groundwater and 614 stream sediment samples. Statistical and areal distribution of uranium and possible uranium-related variables are displayed. A generalized geologic map of the survey area is provided, and pertinent geologic factors which may be of significance in evaluating the potential for uranium mineralization are briefly discussed. Groundwater data indicate that uranium concentrations above the 85th percentile occur primarily in the Upper cretaceous units (Navarro, Taylor, and Woodbine Groups) and Lower Cretaceous carbonate units (Fredricksburg and Wilcox Groups). Saline watermore » trends are also prominent in these units. Stream sediment data indicate high uranium concentrations occur in the western portion of the quadrangle. Most of the samples with high uranium values are collected from the Upper and Lower Cretaceous and Tertiary units. Associated with the high uranium values are high concentrations of aluminum, chromium, iron, scandium, yttrium, zinc, and zirconium.« less

Accumulation of uranium by immobilized persimmon tannin

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

Sakaguchi, Takashi; Nakajima, Akira

1994-01-01

We have discovered that the extracted juice of unripe astringent persimmon fruit, designated as kakishibu or shibuol, has an extremely high affinity for uranium. To develop efficient adsorbents for uranium, we tried to immobilize kakishibu (persimmon tannin) with various aldehydes and mineral acids. Persimmon tannin immobilized with glutaraldehyde can accumulate 1.71 g (14 mEq U) of uranium per gram of the adsorbent. The uranium accumulating capacity of this adsorbent is several times greater than that of commercially available chelating resins (2-3 mEq/g). Immobilized persimmon tannin has the most favorable features for uranium recovery; high selective adsorption ability, rapid adsorption rate,more » and applicability in both column and batch systems. The uranium retained on immobilized persimmon tannin can be quantitatively and easily eluted with a very dilute acid, and the adsorbent can thus be easily recycled in the adsorption-desorption process. Immobilized persimmon tannin also has a high affinity for thorium. 23 refs., 13 figs., 7 tabs.« less

Laser-Assisted Atom Probe Tomography of Deformed Minerals: A Zircon Case Study.

PubMed

La Fontaine, Alexandre; Piazolo, Sandra; Trimby, Patrick; Yang, Limei; Cairney, Julie M

2017-04-01

The application of atom probe tomography to the study of minerals is a rapidly growing area. Picosecond-pulsed, ultraviolet laser (UV-355 nm) assisted atom probe tomography has been used to analyze trace element mobility within dislocations and low-angle boundaries in plastically deformed specimens of the nonconductive mineral zircon (ZrSiO4), a key material to date the earth's geological events. Here we discuss important experimental aspects inherent in the atom probe tomography investigation of this important mineral, providing insights into the challenges in atom probe tomography characterization of minerals as a whole. We studied the influence of atom probe tomography analysis parameters on features of the mass spectra, such as the thermal tail, as well as the overall data quality. Three zircon samples with different uranium and lead content were analyzed, and particular attention was paid to ion identification in the mass spectra and detection limits of the key trace elements, lead and uranium. We also discuss the correlative use of electron backscattered diffraction in a scanning electron microscope to map the deformation in the zircon grains, and the combined use of transmission Kikuchi diffraction and focused ion beam sample preparation to assist preparation of the final atom probe tip.

Uranium from German Nuclear Power Projects of the 1940s— A Nuclear Forensic Investigation

PubMed Central

Mayer, Klaus; Wallenius, Maria; Lützenkirchen, Klaus; Horta, Joan; Nicholl, Adrian; Rasmussen, Gert; van Belle, Pieter; Varga, Zsolt; Buda, Razvan; Erdmann, Nicole; Kratz, Jens-Volker; Trautmann, Norbert; Fifield, L Keith; Tims, Stephen G; Fröhlich, Michaela B; Steier, Peter

2015-01-01

Here we present a nuclear forensic study of uranium from German nuclear projects which used different geometries of metallic uranium fuel.3b,d, 4 Through measurement of the 230Th/234U ratio, we could determine that the material had been produced in the period from 1940 to 1943. To determine the geographical origin of the uranium, the rare-earth-element content and the 87Sr/86Sr ratio were measured. The results provide evidence that the uranium was mined in the Czech Republic. Trace amounts of 236U and 239Pu were detected at the level of their natural abundance, which indicates that the uranium fuel was not exposed to any major neutron fluence. PMID:26501922

Uranium hydrogeochemical and stream sediment reconnaissance data from the area of the Shishmaref, Kotzebue, Selawik and Shungnak Quadrangles, northern Seward Peninsula and vicinity, Alaska

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

Warren, R.G.; Hill, D.E.; Sharp, R.R. Jr.

1978-05-01

During the summer of 1976, 1336 water and 1251 sediment samples were collected for Los Alamos Scientific Laboratory (LASL) from 1356 streams and small lakes or ponds within Shishmaref, Kotzebue, Selawik, and western portion of Shungnak NTMS quadrangles in western Alaska. Both a water and sediment sample were generally obtained from each location at a nominal location density of 1/23 km/sup 2/. Total uranium was measured in waters by fluorometry and in sediments and a few waters by delayed neutron counting at LASL. Uranium concentrations in waters have a mean of 0.31 ppB and a maximum of 9.23 ppB, andmore » sediments exhibit a mean of 3.44 ppM and a maximum of 37.7 ppM. A large number of high-uranium concentrations occur in both water and sediment samples collected in the Selawik Hills. At least two locations within the Selawik Hills appear favorable for further investigation of possible uranium mineralization. A cluster of high-uranium sediments, seen in the Waring Mountains, are probably derived from a lower Cretaceous conglomerate unit which is assocated with known airborne radiometric anomalies. Apparently less favorable areas for further investigation of possible uranium mineralization are also located in the Waring Mountains and Kiana Hills. Additional samples were collected within the Shungnak quadrange to increase the sampling density used elsewhere in the area to about one location per 11 km/sup 2/ (double-density). Contoured plots of uranium concentrations for both waters and sediments were prepared for all double-density sample locations, and then for the even-numbered and odd-numbered locations separately. These plots indicate that the HSSR sampling density of 1/23 km/sup 2/ used in lowland areas of Alaska provide essentially the same definition of relative areal uranium distributions in waters and sediments as seen when the density is doubled. These plots indicate that regional distribution patterns for uranium are well defined without selective sampling of geologic units.« less

MINERALOGY, PETROGRAPHY, AND RADIOACTIVITY OF REPRESENTATIVE SAMPLES OF CHATTANOOGA SHALE

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

Bates, T.F.; Strahl, E.O.

1957-01-01

Qualitative and quantitative mineralogical studies of the Chattanooga Shale are in progress. Problems of separation and analysis of mineral and organic components are difficult because the rock is fine-grained. However, the applicaiion of light and electron microscopy, x-ray diffraction, nuclear-track study, and other methods has provided data of interest. Megascopically, the shalc is a massive chocolate-brown sediment which displays faint indications of lamination. Some pyrite lenses, nodules, and crystals and a few mica flakes are large enough to be seen with a hand lens. In thin section the rock is seen to consist of grains of quartz and feldspar inmore » a matrix of yellow to red--brown organic material, which incorporates shreds of mica and probably clay particles and is dotted by small clusters of pyrite. Larger organic fragments with associated pyrite are common and take various forms. Individual mineral particles range from pyrite cubes less than 0.15 micron on a side to quartz and feldspar grains as large as 0.10 mm. X-ray studies show the clay minerals to be illite, kaolinite, and chlorite in decreasing order of abundance. Tourmaline, zircon, and apatite are the characteristic heavy minerals of the sediment. Quantitative studies, accomplished by a combination of chemical and mineralogical methods, have shown the composition of a batch sample of this rock to be approxiinately: 22% quartz, 9% feldspar, 31% illite and kaolinite, 22% organic matter, 11% pyrite and marcasite, 2% chlorite, 2% iron oxides, and l% tourmaline, zircon, and apatite. Alphatrack studies of cniulsion-covered thin sections indicate that no uranium mineral is present. Approximately 70% of the uranium atoms is randomly distributed throughout the finegrained matrix of the rock, whereas another 25% is concentrated in organic-pyrite-clay complexes such as pyrite nodules and discrete organic bodies. In unweathered samples there is no relationship between uranium distribution and textural fcatures such as bedding. The data indicate that the uranium was precipitated from sea water under reducing conditions and has not been redistributed following compaction of the sediment. (auth)« less

The aqueous geochemistry of uranium in a drainage containing uraniferous organic-rich sediments, Lake Tahoe area, Nevada, USA

USGS Publications Warehouse

Zielinski, R.A.; Otton, J.K.; Wanty, R.B.; Pierson, C.T.

1988-01-01

Anomalously uraniferous waters occur in a small (4.2 km2) drainage in the west-central Carson Range, Nevada, on the eastern side of Lake Tahoe. The waters transport uranium from local U-rich soils and bedrock to organic-rich valley-fill sediments where it is concentrated, but weakly bound. The dissolved U and the U that is potentially available from coexisting sediments pose a threat to the quality of drinking water that is taken from the drainage. The U concentration in samples of 6 stream, 11 spring and 7 near-surface waters ranged from 0.1 V). Possible precipitation of U(IV) minerals is predicted under the more reducing conditions that are particularly likely in near-surface waters, but the inhibitory effects of sluggish kinetics or organic complexing are not considered. These combined results suggest that a process such as adsorption or ion exchange, rather than mineral saturation, is the most probable mechanism for uranium fixation in the sediments. -Authors

An investigation into heterogeneity in a single vein-type uranium ore deposit: Implications for nuclear forensics.

PubMed

Keatley, A C; Scott, T B; Davis, S; Jones, C P; Turner, P

2015-12-01

Minor element composition and rare earth element (REE) concentrations in nuclear materials are important as they are used within the field of nuclear forensics as an indicator of sample origin. However recent studies into uranium ores and uranium ore concentrates (UOCs) have shown significant elemental and isotopic heterogeneity from a single mine site such that some sites have shown higher variation within the mine site than that seen between multiple sites. The elemental composition of both uranium and gangue minerals within ore samples taken along a single mineral vein in South West England have been measured and reported here. The analysis of the samples was undertaken to determine the extent of the localised variation in key elements. Energy Dispersive X-ray spectroscopy (EDS) was used to analyse the gangue mineralogy and measure major element composition. Minor element composition and rare earth element (REE) concentrations were measured by Electron Probe Microanalysis (EPMA). The results confirm that a number of key elements, REE concentrations and patterns used for origin location do show significant variation within mine. Furthermore significant variation is also visible on a meter scale. In addition three separate uranium phases were identified within the vein which indicates multiple uranium mineralisation events. In light of these localised elemental variations it is recommended that representative sampling for an area is undertaken prior to establishing the REE pattern that may be used to identify the originating mine for an unknown ore sample and prior to investigating impact of ore processing on any arising REE patterns. Copyright © 2015 Elsevier Ltd. All rights reserved.

Margaritasite: a new mineral of hydrothermal origin from the Pena Blanca uranium district, Mexico.

USGS Publications Warehouse

Wenrich, K.J.; Modreski, P.J.; Zielinski, R.A.; Seeley, J.L.

1982-01-01

Margaritasite, (Cs,K,H3O)2(UO2)2V2O8.nH2O (where Cs > K, H3O and n approx 1), a 10.514, b 8.425, c 7.25 A, beta 106.01o, P21/a, Z = 2, is a newly recognized uranium ore mineral named for the Margaritas deposit, Pena Blanca uranium district, Chihuahua, Mexico, at which it was discovered. A Cs-rich analogue of carnotite, margaritasite is the natural equivalent of synthetic Cs-uranyl vanadate (A.M. 43- 799, 50-825). A fine-grained yellow mineral, it is most easily distinguished from carnotite by XRD; X-ray powder patterns (CuKalpha radiation) show that the (001) reflection of margaritasite lies at 12.7o (2theta ), while that of carnotite is found at 13.8o (2theta ). The shift of the (001) reflection in margaritasite reflects the structural changes caused when Cs occupies the sites filled by K in carnotite. Synthesis experiments indicate that margaritasite also differs from carnotite in a higher-T hydrothermal origin. Chemical analyses and XRD data for margaritasite and synthetic Cs- carnotite, and chemical analyses for rocks from Sierra Pena Blanca and vicinity, are tabulated.-J.A.Z.

Laboratory Enrichment of Radioactive Assemblages and Estimation of Thorium and Uranium Radioactivity in Fractions Separated from Placer Sands in Southeast Bangladesh

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

Sasaki, Takayuki, E-mail: sasaki@nucleng.kyoto-u.ac.jp; Rajib, Mohammad; Akiyoshi, Masafumi

2015-06-15

The present study reports the likely first attempt of separating radioactive minerals for estimation of activity concentration in the beach placer sands of Bangladesh. Several sand samples from heavy mineral deposits located at the south-eastern coastal belt of Bangladesh were processed to physically upgrade their radioactivity concentrations using plant and laboratory equipment. Following some modified flow procedure, individual fractions were separated and investigated using gamma-ray spectrometry and powder-XRD analysis. The radioactivity measurements indicated contributions of the thorium and uranium radioactive series and of {sup 40}K. The maximum values of {sup 232}Th and {sup 238}U, estimated from the radioactivity of {supmore » 208}Tl and {sup 234}Th in secular equilibrium, were found to be 152,000 and 63,300 Bq/kg, respectively. The fraction of the moderately conductive part in electric separation contained thorium predominantly, while that of the non-conductive part was found to be uranium rich. The present arrangement of the pilot plant cascade and the fine tuning of setting parameters were found to be effective and economic separation process of the radioactive minerals from placer sands in Bangladesh. Probable radiological impacts and extraction potentiality of such radioactive materials are also discussed.« less

Geology of the Anderson Mesa quadrangle, Colorado

USGS Publications Warehouse

Cater, Fred W.; Withington, C.F.

1953-01-01

The Anderson Mesa quadrangle is one of the eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of the southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteenth quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quarternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-tending folds. Conspicuous among the folds are large anticlines having cores of intrusive slat and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing many thousands of tons. The ore consists of largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Uranium in surface soils: an easy-and-quick assay combining X-ray diffraction and fluorescence qualitative data

NASA Astrophysics Data System (ADS)

Figueiredo, M. O.; Silva, T. P.; Batista, M. J.; Leote, J.; Ferreira, M. L.; Limpo, V.

2009-04-01

Portugal has been a uranium-producer since the beginning of the last century. The uranium-rich area of Alto Alentejo, East-central Portugal, was identified more than fifty years ago [1]. Almost all the uranium-bearing mineralization occurs in schistose rocks of the contact metamorphic aureole produced by intrusion of the Hercynian monzonitic granite of Alto Alentejo into the pre-Ordovitian schist-greywacke complex forming deposits of vein and dissemination type. The Nisa uranium-reservoir, situated at the sharp border of a large and arch shaped granite pluton, was identified in 1957 [2] but its exploitation was considered economically impracticable until recently. However, its existence and the accumulated detritus of these prospect efforts are a concern for local populations [3]. A study of the near-surface soils close to the Nisa reservoir was therefore undertaken to assess the uranium retention by adsorption on clay components under the form of uranyl ions, [UO2]2+ [4-6] and its eventual release into the aquifer groundwater. As an attempt to very quickly appraise the presence of uranium in as-collected near-surface sediment samples a combination of laboratory X-ray techniques was designed: X-ray diffraction (XRD) to identify the mineral phases and roughly estimate its relative proportion plus X-ray fluorescence spectrometry in wavelength dispersive mode (XRF-WDS) to ascertain the presence of uranium and tentatively evaluate its content by comparison with selected chemical components of the soil. A description of the experimental methodology adopted for the implemented easy-and-quick uranium assay is presented. Obtained results compare quite well to the data of certified time-consuming analytical tests of uranium in those soil samples. [1] L. Pilar (1966) Conditions of formation of Nisa uranium deposit (in Portuguese). Comunic. Serv. Geol. Portugal, tomo L, 50-85. [2] C. Gonçalves & J.V. Teixeira Lopes (1971) Uranium deposit of Nisa: geological aspects of its discovery and valorisation (in Portuguese). Internal Rept., JEN, 20 pp. [3] http://www.naturtejo.com [4] J.A. Davis et al. (2006) Processes affecting transport of uranium in a suboxic aquifer. Phys. Chem. of the Earth 31, 548-555. [5] Y. Arai et al. (2007) Spectroscopic evidence for uranium bearing precipitates in Vadose zone sediments at the Hanford 300-Area site. Environ. Sci. Technol. 41, 4633-4639. [6] A. Kremleva, S. Krüger & N. Rösch (2008) Density functional model studies of uranyl adsorption on (001) surfaces of kaolinite. Langmuir 24, 9515-9524.

Proteome changes in rat serum after a chronic ingestion of enriched uranium: Toward a biological signature of internal contamination and radiological effect.

PubMed

Petitot, F; Frelon, S; Chambon, C; Paquet, F; Guipaud, O

2016-08-22

The civilian and military use of uranium results in an increased risk of human exposure. The toxicity of uranium results from both its chemical and radiological properties that vary with isotopic composition. Validated biomarkers of health effects associated with exposure to uranium are neither sensitive nor specific to uranium radiotoxicity and/or radiological effect. This study aimed at investigating if serum proteins could be useful as biomarkers of both uranium exposure and radiological effect. Male Sprague-Dawley rats were chronically exposed through drinking water to low levels (40mg/L, corresponding to 1mg of uranium per animal per day) of either 4% (235)U-enriched uranium (EU) or 12% EU during 6 weeks. A proteomics approach based on two-dimensional electrophoresis (2D-DIGE) and mass spectrometry (MS) was used to establish protein expression profiles that could be relevant for discriminating between groups, and to identify some differentially expressed proteins following uranium ingestion. It demonstrated that the expressions of 174 protein spots over 1045 quantified spots were altered after uranium exposure (p<0.05). Using both inferential and non-supervised multivariate statistics, we show sets of spots features that lead to a clear discrimination between controls and EU exposed groups on the one hand (21 spots), and between 4% EU and 12% EU on the other hand (7 spots), showing that investigation of the serum proteome may possibly be of relevance to address both uranium contamination and radiological effect. Finally, using bioinformatics tools, pathway analyses of differentially expressed MS-identified proteins find that acute phase, inflammatory and immune responses as well as oxidative stress are likely involved in the response to contamination, suggesting a physiological perturbation, but that does not necessarily lead to a toxic effect. Copyright © 2016 Elsevier Ireland Ltd. All rights reserved.

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

Kilpatrick, Laura E.; Cotter, Ed

The U.S. Department of Energy (DOE) Office of Legacy Management is responsible for administering the DOE Uranium Leasing Program (ULP) and its 31 uranium lease tracts located in the Uravan Mineral Belt of southwestern Colorado (see Figure 1). In addition to administering the ULP for the last six decades, DOE has also undertaken the significant task of reclaiming a large number of abandoned uranium (legacy) mine sites and associated features located throughout the Uravan Mineral Belt. In 1995, DOE initiated a 3-year reconnaissance program to locate and delineate (through extensive on-the-ground mapping) the legacy mine sites and associated features containedmore » within the historically defined boundaries of its uranium lease tracts. During that same time frame, DOE recognized the lack of regulations pertaining to the reclamation of legacy mine sites and contacted the U.S. Bureau of Land Management (BLM) concerning the reclamation of legacy mine sites. In November 1995, The BLM Colorado State Office formally issued the United States Department of the Interior, Colorado Bureau of Land Management, Closure/Reclamation Guidelines, Abandoned Uranium Mine Sites as a supplement to its Solid Minerals Reclamation Handbook (H-3042-1). Over the next five-and-one-half years, DOE reclaimed the 161 legacy mine sites that had been identified on DOE withdrawn lands. By the late 1990's, the various BLM field offices in southwestern Colorado began to recognize DOE's experience and expertise in reclaiming legacy mine sites. During the ensuing 8 years, BLM funded DOE (through a series of task orders) to perform reclamation activities at 182 BLM mine sites. To date, DOE has reclaimed 372 separate and distinct legacy mine sites. During this process, DOE has learned many lessons and is willing to share those lessons with others in the reclamation industry because there are still many legacy mine sites not yet reclaimed. DOE currently administers 31 lease tracts (11,017 ha) that collectively contain over 220 legacy (abandoned) uranium mine sites. This contrasts to the millions of hectares administered by the BLM, the U.S. Forest Service, and other federal, tribal, and state agencies that contain thousands of such sites. DOE believes that the processes it has used provide a practical and cost-effective approach to abandoned uranium mine-site reclamation. Although the Federal Acquisition Regulations preclude DOE from competing with private industry, DOE is available to assist other governmental and tribal agencies in their reclamation efforts. (authors)« less

RUM JUNGLE PROJECT

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

Australia. Atomic Energy Commission

1963-01-01

A report is presented on the uranium mining and treatment industry established at Rum Jungle and its contribution to the development of the Northern Territory. The Combined Development Agency contract for uranium procurement (terminated in 1963) and some of its results are described. A description of Rum Jungle and its geology and mineralization is given. Mining and treatment of ore are discussed, and some production statistics are given. (D.L.C.)

ALKYL PYROPHOSPHATE METAL SOLVENT EXTRACTANTS AND PROCESS

DOEpatents

Long, R.L.

1958-09-30

A process is presented for the recovery of uranium from aqueous mineral acidic solutions by solvent extraction. The extractant is a synmmetrical dialkyl pyrophosphate in which the alkyl substituents have a chain length of from 4 to 17 carbon atoms. Mentioned as a preferred extractant is dioctyl pyrophosphate. The uranium is precipitated irom the organic extractant phase with an agent such as HF, fluoride salts. alcohol, or ammonia.

Migration behavior of naturally occurring radionuclides at the Nopal I uranium deposit, Chihuahua, Mexico

NASA Astrophysics Data System (ADS)

Prikryl, James D.; Pickett, David A.; Murphy, William M.; Pearcy, English C.

1997-04-01

Oxidation of pyrite at the Nopal I uranium deposit, Peña Blanca district, Chihuahua, Mexico has resulted in the formation of Fe-oxides/hydroxides. Anomalous U concentrations (i.e. several hundred to several thousand ppm) measured in goethite, hematite, and amorphous Fe-oxyhydroxides in a major fracture that crosscuts the deposit and the absence of U minerals in the fracture suggest that U was retained during secondary mineral growth or sorbed on mineral surfaces. Mobilization and transport of U away from the deposit is suggested by decreasing U concentrations in fracture-infilling materials and in goethite and hematite with distance from the deposit. Greater than unity {234U}/{238U} activity ratios measured in fracture-infilling materials indicate relatively recent ( < 1 Ma) U uptake from fluids that carried excess 234U. Systematic decreases in {234U}/{238U} activity ratios of fracture materials with distance from the deposit suggest a multistage mobilization process, such as remobilization of U from 234U-enriched infill minerals or differential or diminished transport of U-bearing solutions containing excess 234U.

ISOTOPIC EVIDENCE ON THE ORIGIN AND AGE OF THE BLIND RIVER URANIUM DEPOSITS

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

Mair, J.A.; Maynes, A.D.; Patchett, J.E.

Isotopic analyses of lead extracted from a variety of minerals from Blind River. Ontario, are repeated. The detrital minerals monazite and zircon both give leadratio ages of 2500 million years. The uraainite ore gives a lead- ratio age of 1700 m a. Other isotopic evidence is quoted to suggest that the age of the sediment in which the uranium is found may also be approximately 1700 m y, or older. The lead found in pyrite, pyrrhotite, sericite, and feldspar has anomalous isotopic ratios which can be explained by the hypothesis that they received additions of radiogenic lead from the uraninitesmore » (presumed to be 1700 m y old) 1200 to 1300 m y ago. In any case the age of these minerals, in the sense of time of last chemical alteration, is not greater than 1450 plus or minus 150 m y. All our measurements can be interpreted without asauming a major period of mineralization more recent than 1000 m y ago, although we are unable to rule out such a possibility from our evidence. (auth)« less

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.

Organic geochemical analysis of sedimentary organic matter associated with uranium

USGS Publications Warehouse

Leventhal, J.S.; Daws, T.A.; Frye, J.S.

1986-01-01

Samples of sedimentary organic matter from several geologic environments and ages which are enriched in uranium (56 ppm to 12%) have been characterized. The three analytical techniqyes used to study the samples were Rock-Eval pyrolysis, pyrolysis-gas chromatography-mass spectrometry, and solid-state C-13 nuclear magnetic resonance (NMR) spectroscopy. In samples with low uranium content, the pyrolysis-gas chromatography products contain oxygenated functional groups (as hydroxyl) and molecules with both aliphatic and aromatic carbon atoms. These samples with low uranium content give measurable Rock-Eval hydrocarbon and organic-CO2 yields, and C-13 NMR values of > 30% aliphatic carbon. In contrast, uranium-rich samples have few hydrocarbon pyrolysis products, increased Rock-Eval organic-CO2 contents and > 70% aromatic carbon contents from C-13 NMR. The increase in aromaticity and decrease in hydrocarbon pyrolysis yield are related to the amount of uranium and the age of the uranium minerals, which correspond to the degree of radiation damage. The three analytical techniques give complementary results. Increase in Rock-Eval organic-CO2 yield correlates with uranium content for samples from the Grants uranium region. Calculations show that the amount of organic-CO2 corresponds to the quantity of uranium chemically reduced by the organic matter for the Grants uranium region samples. ?? 1986.

Consequences of slow growth for 230Th/U dating of Quaternary opals, Yucca Mountain, NV, USA

USGS Publications Warehouse

Neymark, L.A.; Paces, J.B.

2000-01-01

Thermal ionization mass-spectrometry 234U/238U and 230Th/238U data are reported for uranium-rich opals coating fractures and cavities within the silicic tuffs forming Yucca Mountain, NV, the potential site of a high-level radioactive waste repository. High uranium concentrations (up to 207 ppm) and extremely high 230Th/232Th activity ratios (up to about 106) make microsamples of these opals suitable for precise 230Th/U dating. Conventional 230Th/U ages range from 40 to greater than 600 ka, and initial 234U/238U activity ratios between 1.03 and 8.2. Isotopic evidence indicates that the opals have not experienced uranium mobility; however, wide variations in apparent ages and initial 234U/238U ratios for separate subsamples of the same outermost mineral surfaces, positive correlation between ages and sample weights, and negative correlation between 230Th/U ages and calculated initial 234U/238U are inconsistent with the assumption that all minerals in a given subsample was deposited instantaneously. The data are more consistent with a conceptual model of continuous deposition where secondary mineral growth has occurred at a constant, slow rate up to the present. This model assumes that individual subsamples represent mixtures of older and younger material, and that calculations using the resulting isotope ratios reflect an average age. Ages calculated using the continuous-deposition model for opals imply average mineral growth rates of less than 5 mm/m.y. The model of continuous deposition also predicts discordance between ages obtained using different radiometric methods for the same subsample. Differences in half-lives will result in younger apparent ages for the shorter-lived isotope due to the greater influence of younger materials continuously added to mineral surfaces. Discordant 14C, 230Th/U and U-Pb ages obtained from outermost mineral surfaces at Yucca Mountain support this model. (C) 2000 Elsevier Science B.V. All rights reserved.

Influence of uranium on bacterial communities: a comparison of natural uranium-rich soils with controls.

PubMed

Mondani, Laure; Benzerara, Karim; Carrière, Marie; Christen, Richard; Mamindy-Pajany, Yannick; Février, Laureline; Marmier, Nicolas; Achouak, Wafa; Nardoux, Pascal; Berthomieu, Catherine; Chapon, Virginie

2011-01-01

This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil.

Influence of Uranium on Bacterial Communities: A Comparison of Natural Uranium-Rich Soils with Controls

PubMed Central

Mondani, Laure; Benzerara, Karim; Carrière, Marie; Christen, Richard; Mamindy-Pajany, Yannick; Février, Laureline; Marmier, Nicolas; Achouak, Wafa; Nardoux, Pascal; Berthomieu, Catherine; Chapon, Virginie

2011-01-01

This study investigated the influence of uranium on the indigenous bacterial community structure in natural soils with high uranium content. Radioactive soil samples exhibiting 0.26% - 25.5% U in mass were analyzed and compared with nearby control soils containing trace uranium. EXAFS and XRD analyses of soils revealed the presence of U(VI) and uranium-phosphate mineral phases, identified as sabugalite and meta-autunite. A comparative analysis of bacterial community fingerprints using denaturing gradient gel electrophoresis (DGGE) revealed the presence of a complex population in both control and uranium-rich samples. However, bacterial communities inhabiting uraniferous soils exhibited specific fingerprints that were remarkably stable over time, in contrast to populations from nearby control samples. Representatives of Acidobacteria, Proteobacteria, and seven others phyla were detected in DGGE bands specific to uraniferous samples. In particular, sequences related to iron-reducing bacteria such as Geobacter and Geothrix were identified concomitantly with iron-oxidizing species such as Gallionella and Sideroxydans. All together, our results demonstrate that uranium exerts a permanent high pressure on soil bacterial communities and suggest the existence of a uranium redox cycle mediated by bacteria in the soil. PMID:21998695

Uranium from German Nuclear Power Projects of the 1940s--A Nuclear Forensic Investigation.

PubMed

Mayer, Klaus; Wallenius, Maria; Lützenkirchen, Klaus; Horta, Joan; Nicholl, Adrian; Rasmussen, Gert; van Belle, Pieter; Varga, Zsolt; Buda, Razvan; Erdmann, Nicole; Kratz, Jens-Volker; Trautmann, Norbert; Fifield, L Keith; Tims, Stephen G; Fröhlich, Michaela B; Steier, Peter

2015-11-02

Here we present a nuclear forensic study of uranium from German nuclear projects which used different geometries of metallic uranium fuel. Through measurement of the (230)Th/(234)U ratio, we could determine that the material had been produced in the period from 1940 to 1943. To determine the geographical origin of the uranium, the rare-earth-element content and the (87)Sr/(86)Sr ratio were measured. The results provide evidence that the uranium was mined in the Czech Republic. Trace amounts of (236)U and (239)Pu were detected at the level of their natural abundance, which indicates that the uranium fuel was not exposed to any major neutron fluence. © 2015 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.

METHOD OF ELECTROPLATING ON URANIUM

DOEpatents

Rebol, E.W.; Wehrmann, R.F.

1959-04-28

This patent relates to a preparation of metallic uranium surfaces for receiving coatings, particularly in order to secure adherent electroplated coatings upon uranium metal. In accordance with the invention the uranium surface is pretreated by degreasing in trichloroethylene, followed by immersion in 25 to 50% nitric acid for several minutes, and then rinsed with running water, prior to pickling in trichloroacetic acid. The last treatment is best accomplished by making the uranium the anode in an aqueous solution of 50 per cent by weight trichloroacetic acid until work-distorted crystals or oxide present on the metal surface have been removed and the basic crystalline structure of the base metal has been exposed. Following these initial steps the metallic uranium is rinsed in dilute nitric acid and then electroplated with nickel. Adnerent firmly-bonded coatings of nickel are obtained.

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

Saccomanno, G.

''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 minersmore » (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.« less

The determination of uranium (IV) in apatite

USGS Publications Warehouse

Clarke, Roy S.; Altschuler, Zalman S.

1956-01-01

Geologic and mineralogic evidence indicate that the uranium present in apatite may proxy for calcium in the mineral structure as U(IV). An experimental investigation was conducted and chemical evidence was obtained that establishes the presence of U(IV) in apatite. The following analytical procedure was developed for the determination of U(IV). Carbonate-fluorapatite is dissolved in cold 1.5M orthophosphoric acid and fluorapatite is dissolved in cold 1.2M hydrochloric acid containing 1.5 g of hydroxylamine hydrochloride per 100 ml. Uranium (IV) is precipitated by cupferron using titanium as a carrier. The uranium in the precipitate is separated by use of the ethyl acetate extraction procedure and determined fluorimetrically. The validity and the limitations of the method have been established by spike experiments.

Uranium in the Mayoworth area, Johnson County, Wyoming - a preliminary report

USGS Publications Warehouse

Love, J.D.

1954-01-01

The uranium mineral, metatyuyamunite, occurs in the basal limestone of the Sundance formation of late Jurassic age along the east flank of the Bighorn Mountains, about 2 miles southwest of the abandoned Mayoworth post office. This occurrence is of particular interest because it is the first uranium mineralization reported from a marine limestone in Wyoming. The discovery uranium claims were filed in July 1953, by J.S. Masek, Dan Oglesby, and Jack Emery of Casper, Wyo. Subsequent reconnaissance investigations have been made by private individuals and geologists of the U.S. Geological Survey and Atomic Energy Commission. The metatyuyamunite is concentrated in a hard gray oolitic limestone that forms the basal bed of the Sundance formation. A selected sample of limestone from a fresh face in the northernmost deposit known at the time of the field examination contained 0.70 percent equivalent uranium and 0.71 percent uranium. Eight samples of the limestone taken at the sample place by the Atomic Energy Commission contained from 0.007 to 0.22 percent uranium. A chip sample from the weathered outcrop at the top of this limestone half a mile to the southeast contained 0.17 percent equivalent uranium and 0.030 percent uranium. A dinosaur bone from the middle part of the Morrison formation contained 0.044 percent equivalent uranium and 0.004 percent uranium. metatyuyamunite forms a conspicuous yellow coating along fracture planes cutting the oolitic limestone and has also replaced many of the oolites within the solid limestone and has also replaced many of the oolites within the solid limestone even where fractures are not present. Many radioactive spots in the basal limestone of the Sundance formation were examined in a reconnaissance fashion along the outcrop for a distance of half a mile south of the initial discovery. Samples were taken for analysis only at the northern and southern margins of this interval. Outcrops farther north and south were not studied. There are not sufficient data to make even rough estimates of tonnage and grade of the occurrences. The extent of the limestone, the approximate boundaries of the area of above-normal radioactivity, and the possibilities of other radioactive zones have not been thoroughly investigated. Although dinosaur bones in the Morrison formation were radioactive wherever they were tested, no significant amount of radioactivity was observed in rocks adjacent to the bones.

Progress report on geologic studies of the Ranger orebodies, Northern Territory, Australia

USGS Publications Warehouse

Nash, J.T.; Frishman, David

1982-01-01

The Ranger No. 1 and No. 3 orebodies contain about 124,000 tonnes U3O8 in highly chloritized metasediments of the lower Proterozoic Cahill Formation within about 500 m of the projected sub-Kombolgie Formation unconformity. In both orebodies, oxidized and reduced uranium minerals occur chiefly in quartzose schists that have highly variable amounts of muscovite, sericite, and chlorite. The effects of several periods of alteration are pervasive in the vicinity of orebodies where biotite and garnet are altered to chlorite, and feldspars to white mica or chlorite. Oxidized uranium minerals, associated with earthy iron oxides, occur from the surface to a depth of about 60 m. Below the oxidized zone, uranium occurs chiefly as uraninite and pitchblende disseminated through thick sections of quartz-chlorite-muscovite schist and has no apparent association with graphite or sulfides. In fact, graphite is rare and sulfides are generally low in abundance (<0.5 percent). Higher ore grades occur in disrupted zones a few centimeters thick and in some quartz-chlorite vein-like zones of uncertain origin. Uranium correlates strongly with chlorite, but not all of the many ages of chlorite have associated uranium. At least five textural varieties of chlorite are present and represent at least 3 ages. Preliminary microprobe analyses suggest that Mg-Fe-Al contents are relatively uniform. Apatite commonly occurs with chlorite. Uranium is not common in carbonate rocks and seems to occur only in disrupted zones that have chlorite alteration. Chloritization and silicification are more widespread and intense in the No. 1 orebody than in the No. 3. In both orebodies, hematite occurs tens to hundreds of meters below the weathered zone, in both altered and largely unaltered rocks, with and without uranium. The structure of the orebodies is outwardly simple, particularly in No. 3; dips are less than 40? on most lithologic contacts. The No. 1 orebody is in a basin-like structure about 400 m wide that probably formed in part by progressive removal of carbonate rocks that are as much as 200 m thick adjacent to the No. 1 orebody and below the No. 3 orebody. Quartz-chlorite breccias have formed in the zone of carbonate thinning; uranium is spotty and low grade in these breccias. Chloritized and uraniferous broken and sheared zones, a few centimeters to a few meters thick, have an unknown attitude but must have small displacement. Blocks of altered Kombolgie sandstone are downfaulted into the No. 3 orebody and locally contain reduced uranium minerals. One or more shear zones 5-30 m thick of crushed and smeared fine to coarse rock fragments occur below the orebodies, and other low-angle shears probably occur in the orebodies. The shear zone dips about 40 o and displacement on it is not known. The footwall rocks generally are less retrograded than those in the hanging wall (orebody) and consist of quartz-biotite-feldspar schists and gneisses flanking the Nanambu Complex. A few scattered fractures in the footwall sequence contain pitchblende of unknown age and origin. Major element chemical analyses confirm the lithologic observations of large changes in composition during multiple stages of alteration. Granitic dikes and pelitic schists have gained Fe and Mg and lost Si, Ca, Na, and K during chloritization. Marbles have gained Si, Al, Fe, and P, and lost Mg, Ca, and K during jasperoid-chlorite alteration. Total net chemical gains and losses in the Ranger No. 1 orebody were huge: equal to about 37 percent of the mass of the ore-bearing rock that will be mined. There were net gains in Si and P and net losses in Al, Fe, Mg, Ca, K, and Na. The geologic age(s) of uranium emplacement are obscure because there are few age criteria. Reduced uranium minerals are younger than 1.8-b.y.-old granite dikes, and some occur locally in 1.65-b.y.-old Kombolgie Formation. Diabase dikes (age not known) are thoroughly chloritized and contain sparse ore minerals. Oxidized ura

VapC toxins drive cellular dormancy under uranium stress for the extreme thermoacidophile Metallosphaera prunae.

PubMed

Mukherjee, Arpan; Wheaton, Garrett H; Counts, James A; Ijeomah, Brenda; Desai, Jigar; Kelly, Robert M

2017-07-01

When abruptly exposed to toxic levels of hexavalent uranium, the extremely thermoacidophilic archaeon Metallosphaera prunae, originally isolated from an abandoned uranium mine, ceased to grow, and concomitantly exhibited heightened levels of cytosolic ribonuclease activity that corresponded to substantial degradation of cellular RNA. The M. prunae transcriptome during 'uranium-shock' implicated VapC toxins as possible causative agents of the observed RNA degradation. Identifiable VapC toxins and PIN-domain proteins encoded in the M. prunae genome were produced and characterized, three of which (VapC4, VapC7, VapC8) substantially degraded M. prunae rRNA in vitro. RNA cleavage specificity for these VapCs mapped to motifs within M. prunae rRNA. Furthermore, based on frequency of cleavage sequences, putative target mRNAs for these VapCs were identified; these were closely associated with translation, transcription, and replication. It is interesting to note that Metallosphaera sedula, a member of the same genus and which has a nearly identical genome sequence but not isolated from a uranium-rich biotope, showed no evidence of dormancy when exposed to this metal. M. prunae utilizes VapC toxins for post-transcriptional regulation under uranium stress to enter a cellular dormant state, thereby providing an adaptive response to what would otherwise be a deleterious environmental perturbation. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

A literature review of interaction of oxidized uranium species and uranium complexes with soluble organic matter

USGS Publications Warehouse

Jennings, Joan K.; Leventhal, J.S.

1978-01-01

Organic material is commonly found associated with uranium ores in sandstone-type deposits. This review of the literature summarizes the classes and separations of naturally occurring organic material but the emphasis is on soluble organic species. The main class of materials of interest is humic substances which are high-molecular-weight complex molecules that are soluble in alkaline solution. These humic substances are able to solubilize (make soluble) minerals and also to complex [by ion exchange and (or) chelation] many cations. The natural process of soil formation results in both mineral decomposition and element complexing by organic species. Uranium in solution, such as ground water, can form many species with other elements or complexes present depending on Eh and pH. In natural systems (oxidizing Eh, pH 5-9) the uranium is usually present as a complex with hydroxide or carbonate. Thermodynamic data for these species are presented. Interacting metals and organic materials have been observed in nature and studied in the laboratory by many workers in diverse scientific disciplines. The results are not easily compared. Measurements of the degree of complexation are reported as equilibrium stability constant determinations. This type of research has been done for Mn, Fe, Cu, Zn, Pb, Ni, Co, Mg, Ca, Al, and to a limited degree for U. The use of Conditional Stability Constants has given quantitative results in some cases. The methods utilized in experiments and calculations are reviewed.

Impact of quaternary climate on seepage at Yucca Mountain, Nevada

USGS Publications Warehouse

Whelan, J.F.; Paces, J.B.; Neymark, L.A.; Schmitt, A.K.; Grove, M.

2006-01-01

Uranium-series ages, oxygen-isotopic compositions, and uranium contents were determined in outer growth layers of opal and calcitefrom 0.5- to 3-centimeter-thick mineral coatings hosted by lithophysal cavities in the unsaturated zone at Yucca Mountain, Nevada, the proposed site of a permanent repository for high-level radioactive waste. Micrometer-scale growth layering in the minerals was imaged using a cathodoluminescence detector on a scanning electron microscope. Determinations of the chemistry, ages, and delta oxygen-18 (??18O) values of the growth layers were conducted by electron microprobe analysis and secondary ion mass spectrometry techniques at spatial resolutions of 2 to about 20 micrometers (??m) and 25 to 40 ??m, respectively. Growth rates for the last 300 thousand years (k.y.) calculated from about 300 new high-resolution uranium-series ages range from approximately 0.5 to 1.5 ??m/k.y. for 1- to 3-centimeter-thick coatings, whereas coatings less than about 1-centimeter-thick have growth rates less than 0.5 ??m/k.y. At the depth of the proposed repository, correlations of uranium concentration and ??18O values with regional climate records indicate that unsaturated zone percolation and seepage water chemistries have responded to changes in climate during the last several hundred thousand years.

Measurement of 238U and 232Th radionuclides in ilmenite and synthetic rutile

NASA Astrophysics Data System (ADS)

Idris, M. I.; Siong, K. K.; Fadzil, S. M.

2018-01-01

The only factory that currently processes ilmenite to produce synthetic rutile is Tor Minerals in Ipoh, Perak, Malaysia. These two minerals contain radioactive elements such as uranium and thorium. Furthermore, this factory was built close to the residential areas. Thus, the primary issues are radiation exposure attributed to the decay of the radionuclides. Hence, the objectives of this study are to measure the dose and to evaluate activity levels of uranium and thorium. Dose rates from surrounding area of factory indicate the normal range for both on the surface and 1 meter above the ground (0.3-0.7 μSv/hr) lower than the global range of 0.5-1.3 μSv/hr set by UNSCEAR. The mean activity levels of uranium and thorium for ilmenite are 235 Bq/kg and 503 Bq/kg while for synthetic rutile are 980 Bq/kg and 401 Bq/kg, respectively. The result shows that uranium activity levels of synthetic rutile is 4 times higher than ilmenite but it is still lower than the regulatory exemption limit of 1000 Bq/kg set by IAEA Basic Safety Standards. Even though the dose rates at the factory and the activity levels are within safe limits, safety precautions must be followed by the factory management to prevent any unwanted accident to occur.

Practical issues in discriminating between environmental and occupational sources in a uranium urinalysis bioassay program

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

Long, M.P.; Carbaugh, E.H.; Fairrow, N.L.

1994-11-01

Workers at two Department of Energy facilities, the Pantex Plant in Texas and the Hanford Site in Washington, are potentially exposed to class Y depleted or natural uranium. Since trace amounts of uranium are naturally present in urine excretion, site bioassay programs must be able to discern occupational exposure from naturally occurring uranium exposure. In 1985 Hanford established a 0.2-{mu}g/d environmental screening level for elemental uranium in urine; the protocol was based on log-normal probability analysis of unexposed workers. A second study of background uranium levels commenced in 1990, and experiences in the field indicated that there seemed to bemore » an excessive number of urine samples with uranium above the screening level and that the environmental screening level should be reviewed. Due to unforeseen problems, that second study was terminated before the complete data could be obtained. Natural uranium in rock (by weight, 99.27% {sup 288}U, 0.72% {sup 235}U, and 0.006% {sup 234}U) has approximately equal activity concentrations of {sup 238}U and {sup 234}U. Earlier studies, summarized by the U.S. Environmental Protection Agency in 51 FR 32068, have indicated that {sup 234}U (via {sup 234}Th) has a greater environmental mobility than {sup 238}U and may well have a higher concentration in ground water. By assuming that the {sup 238}U-to {sup 234}U ratio in the urine of nonoccupationally exposed persons should reflect the ratio of environmental levels, significant occupational exposure to depleted uranium would shift that ratio in favor of {sup 238}U, allowing use of the ratio as a co-indicator of occupational exposure in addition to the isotope-specific screening levels. This approach has been adopted by Pantex. The Pacific Northwest Laboratory is studying the feasibility of applying this method to the natural and recycled uranium mixtures encountered at Hanford. The Hanford data included in this report represent work-in-progress.« less

26 CFR 1.613-2 - Percentage depletion rates.

Code of Federal Regulations, 2012 CFR

2012-04-01

... minerals are produced: (i) 271/2 percent—Gas wells, oil wells. (ii) 23 percent—Sulfur, uranium. (iii) 15... in the deposit. Example 2. Oil and gas are produced from a single mineral property of a taxpayer who operates a retail outlet for the sale of oil products within the meaning of section 613A(d)(2). The...

26 CFR 1.613-2 - Percentage depletion rates.

Code of Federal Regulations, 2010 CFR

2010-04-01

... minerals are produced: (i) 271/2 percent—Gas wells, oil wells. (ii) 23 percent—Sulfur, uranium. (iii) 15... in the deposit. Example 2. Oil and gas are produced from a single mineral property of a taxpayer who operates a retail outlet for the sale of oil products within the meaning of section 613A(d)(2). The...

26 CFR 1.613-2 - Percentage depletion rates.

Code of Federal Regulations, 2011 CFR

2011-04-01

... minerals are produced: (i) 271/2 percent—Gas wells, oil wells. (ii) 23 percent—Sulfur, uranium. (iii) 15... in the deposit. Example 2. Oil and gas are produced from a single mineral property of a taxpayer who operates a retail outlet for the sale of oil products within the meaning of section 613A(d)(2). The...

26 CFR 1.613-2 - Percentage depletion rates.

Code of Federal Regulations, 2014 CFR

2014-04-01

... minerals are produced: (i) 271/2 percent—Gas wells, oil wells. (ii) 23 percent—Sulfur, uranium. (iii) 15... in the deposit. Example 2. Oil and gas are produced from a single mineral property of a taxpayer who operates a retail outlet for the sale of oil products within the meaning of section 613A(d)(2). The...

26 CFR 1.613-2 - Percentage depletion rates.

Code of Federal Regulations, 2013 CFR

2013-04-01

... minerals are produced: (i) 271/2 percent—Gas wells, oil wells. (ii) 23 percent—Sulfur, uranium. (iii) 15... in the deposit. Example 2. Oil and gas are produced from a single mineral property of a taxpayer who operates a retail outlet for the sale of oil products within the meaning of section 613A(d)(2). The...

Preliminary notes on distribution of uranium in the Florida pebble phosphate field and suggestions for studying and sampling

USGS Publications Warehouse

,

1948-01-01

The accompanying map and sections show examples of the present state of information about the occurrence of the "Leached" uranium-bearing bed in the Florida pebble phosphate district. The dashed lines on the map define, as closely as present data permit, the limit of the area in which this bed contains significant amounts of uranium. The figures next to localities on the map indicate first, the thickness of the bed in feet; and second the uranium content in thousandths of percent. For example, the figures 16-10 next to the TVA localities in Secs. 9 and 10, T. 32 S., R. 26 E. indicate 16 feet at 0.010 percent uranium. A "0" by a locality indicates either that the uranium content is less than 0.001 percent or less than the concentration in the underlying phosphate beds (matrix of the miners) or that the leached bed is not present.

Identifying anthropogenic uranium compounds using soft X-ray near-edge absorption spectroscopy

NASA Astrophysics Data System (ADS)

Ward, Jesse D.; Bowden, Mark; Tom Resch, C.; Eiden, Gregory C.; Pemmaraju, C. D.; Prendergast, David; Duffin, Andrew M.

2017-01-01

Uranium ores mined for industrial use are typically acid-leached to produce yellowcake and then converted into uranium halides for enrichment and purification. These anthropogenic chemical forms of uranium are distinct from their mineral counterparts. The purpose of this study is to use soft X-ray absorption spectroscopy to characterize several common anthropogenic uranium compounds important to the nuclear fuel cycle. Chemical analyses of these compounds are important for process and environmental monitoring. X-ray absorption techniques have several advantages in this regard, including element-specificity, chemical sensitivity, and high spectral resolution. Oxygen K-edge spectra were collected for uranyl nitrate, uranyl fluoride, and uranyl chloride, and fluorine K-edge spectra were collected for uranyl fluoride and uranium tetrafluoride. Interpretation of the data is aided by comparisons to calculated spectra. The effect of hydration state on the sample, a potential complication in interpreting oxygen K-edge spectra, is discussed. These compounds have unique spectral signatures that can be used to identify unknown samples.

Botanical prospecting for uranium on La Ventana Mesa, Sandoval County, New Mexico

USGS Publications Warehouse

Starrett, Wm. H.; Cannon, Helen L.

1954-01-01

A botanical sampling program has been completed by the U.S. Geological Survey on La Ventana Mesa, Sandoval County, N. Mex. A uranium-bearing coal in the Allison-Gibson members of the Cretaceous Mesaverde formation crops out in erosional remnants of the mesa.The coal is capped by a well-fractured 65-foot sandstone bed through which roots of a pinyon-juniper forest penetrate. Samples of several hundred branches of trees growing on top of the mesa were collected and analyzed for uranium. The assays ranged from 0.1 part per million to 2.3 ppm uranium in the wood ash. Dead branches, which were found to contain more uranium in the ash than live branches, were sampled where possible. The results have been contoured to indicated probable areas of mineralized coal. Parts of the north butte are recommended as favorable for physical exploration.

Comparison of the mineralogy of the Boss-Bixby, Missouri copper-iron deposit, and the Olympic Dam copper-uranium-gold deposit, South Australia

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

Brandom, R.T.; Hagni, R.D.; Allen, C.R.

1985-01-01

An ore microscopic examination of 80 polished sections prepared from selected drill core specimens from the Boss-Bixby, Missouri copper-iron deposit has shown that its mineral assemblage is similar to that of the Olympic Dam (Roxby Downs) copper-uranium-gold deposit in South Australia. A comparison with the mineralogy reported for Olympic Dam shows that both deposits contain: 1) the principal minerals, magnetite, hematite, chalcopyrite, and bornite, 2) the cobalt-bearing phases, carrollite and cobaltian pyrite, 3) the titanium oxides, rutile and anatase, 4) smaller amounts of martite, covellite, and electrum, 5) fluorite and carbonates, and 6) some alteration minerals. The deposits also aremore » similar with regard to the sequence of mineral deposition: 1) early oxides, 2) then sulfide minerals, and 3) a final oxide generation. The deposits, however, are dissimilar with regard to their host rock lithologies and structural settings. The Boss-Bixby ores occupy breccia zones within a hydrothermally altered basic intrusive and intruded silicic volcanics, whereas the Olympic Dam ores are contained in sedimentary breccias in a graben or trough. Also, some minerals have been found thus far to occur at only one of the deposits. The similarity of mineralogy in these deposits suggests that they were formed from ore fluids that had some similarities in character and that the St. Francois terrane of Missouri is an important region for further exploration for deposits with this mineral assemblage.« less

Radionuclide sorption in Yucca Mountain tuffs with J-13 well water: Neptunium, uranium, and plutonium. Yucca Mountain site characterization program milestone 3338

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

Triay, I.R.; Cotter, C.R.; Kraus, S.M.

1996-08-01

We studied the retardation of actinides (neptunium, uranium, and plutonium) by sorption as a function of radionuclide concentration in water from Well J-13 and of tuffs from Yucca Mountain. Three major tuff types were examined: devitrified, vitric, and zeolitic. To identify the sorbing minerals in the tuffs, we conducted batch sorption experiments with pure mineral separates. These experiments were performed with water from Well J-13 (a sodium bicarbonate groundwater) under oxidizing conditions in the pH range from 7 to 8.5. The results indicate that all actinides studied sorb strongly to synthetic hematite and also that Np(V) and U(VI) do notmore » sorb appreciably to devitrified or vitric tuffs, albite, or quartz. The sorption of neptunium onto clinoptilolite-rich tuffs and pure clinoptilolite can be fitted with a sorption distribution coefficient in the concentration range from 1 X 10{sup -7} to 3 X 10{sup -5} M. The sorption of uranium onto clinoptilolite-rich tuffs and pure clinoptilolite is not linear in the concentration range from 8 X 10{sup -8} to 1 X 10{sup -4} M, and it can be fitted with nonlinear isotherm models (such as the Langmuir or the Freundlich Isotherms). The sorption of neptunium and uranium onto clinoptilolite in J-13 well water increases with decreasing pH in the range from 7 to 8.5. The sorption of plutonium (initially in the Pu(V) oxidation state) onto tuffs and pure mineral separates in J-13 well water at pH 7 is significant. Plutonium sorption decreases as a function of tuff type in the order: zeolitic > vitric > devitrified; and as a function of mineralogy in the order: hematite > clinoptilolite > albite > quartz.« less

A Uranium Bioremediation Reactive Transport Benchmark

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

Yabusaki, Steven B.; Sengor, Sevinc; Fang, Yilin

A reactive transport benchmark problem set has been developed based on in situ uranium bio-immobilization experiments that have been performed at a former uranium mill tailings site in Rifle, Colorado, USA. Acetate-amended groundwater stimulates indigenous microorganisms to catalyze the reduction of U(VI) to a sparingly soluble U(IV) mineral. The interplay between the flow, acetate loading periods and rates, microbially-mediated and geochemical reactions leads to dynamic behavior in metal- and sulfate-reducing bacteria, pH, alkalinity, and reactive mineral surfaces. The benchmark is based on an 8.5 m long one-dimensional model domain with constant saturated flow and uniform porosity. The 159-day simulation introducesmore » acetate and bromide through the upgradient boundary in 14-day and 85-day pulses separated by a 10 day interruption. Acetate loading is tripled during the second pulse, which is followed by a 50 day recovery period. Terminal electron accepting processes for goethite, phyllosilicate Fe(III), U(VI), and sulfate are modeled using Monod-type rate laws. Major ion geochemistry modeled includes mineral reactions, as well as aqueous and surface complexation reactions for UO2++, Fe++, and H+. In addition to the dynamics imparted by the transport of the acetate pulses, U(VI) behavior involves the interplay between bioreduction, which is dependent on acetate availability, and speciation-controlled surface complexation, which is dependent on pH, alkalinity and available surface complexation sites. The general difficulty of this benchmark is the large number of reactions (74), multiple rate law formulations, a multisite uranium surface complexation model, and the strong interdependency and sensitivity of the reaction processes. Results are presented for three simulators: HYDROGEOCHEM, PHT3D, and PHREEQC.« less

SANTA LUCIA WILDERNESS, AND GARCIA MOUNTAIN, BLACK MOUNTAIN, LA PANZA, MACHESNA MOUNTAIN, LOS MACHOS HILLS, BIG ROCKS, AND STANLEY MOUNTAIN ROADLESS AREAS, CALIFORNIA.

USGS Publications Warehouse

Frizzell, Virgil A.; Kuizon, Lucia

1984-01-01

The Santa Lucia Wilderness Area and Garcia Mountain, Black Mountain, La Panza, Machesna Mountain, Los Machos Hills, Big Rocks, and Stanley Mountain Roadless Areas together occupy an area of about 218 sq mi in the Los Padres National Forest, California. On the basis of a mineral-resource evaluation a small area in the Black Mountain Roadless Area has a probable mineral-resource potential for uranium, and a small area in the Stanley Mountain Roadless Area has probable potential for low-grade mercury resources. Although petroleum resources occur in rocks similar to those found in the study area, no potential for petroleum resources was identified in the wilderness or any of the roadless areas. No resource potential for other mineral resources was identified in any of the areas. Detailed geologic mapping and geochemical sampling probably would increase knowledge about distribution and modes of occurrence of uranium and cinnabar in those areas, respectively.

Rapid Dissolution of Soluble Uranyl Phases in Arid, Mine-Impacted Catchments Near Church Rock, NM

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

deLemos, J.L.; Bostick, B.C.; Quicksall, A.N.

2009-05-14

We tested the hypothesis that runoff of uranium-bearing particles from mining waste disposal areas was a significant mechanism for redistribution of uranium in the northeastern part of the Upper Puerco River watershed (New Mexico). However, our results were not consistent with this hypothesis. Analysis of >100 sediment and suspended sediment samples collected adjacent to and downstream from uranium source areas indicated that uranium levels in the majority of the samples were not elevated above background. Samples collected within 50 m of a known waste disposal site were subjected to detailed geochemical characterization. Uranium in these samples was found to bemore » highly soluble; treatment with synthetic pore water for 24 h caused dissolution of 10-50% of total uranium in the samples. Equilibrium uranium concentrations in pore water were >4.0 mg/L and were sustained in repeated wetting events, effectively depleting soluble uranium from the solid phase. The dissolution rate of uranium appeared to be controlled by solid-phase diffusion of uranium from within uranium-bearing mineral particles. X-ray adsorption spectroscopy indicated the presence of a soluble uranyl silicate, and possibly a uranyl phosphate. These phases were exhausted in transported sediment suggesting that uranium was readily mobilized from sediments in the Upper Puerco watershed and transported in the dissolved load. These results could have significance for uranium risk assessment as well as mining waste management and cleanup efforts.« less

Comparison of the Kinetic Rate Law Parameters for the Dissolution of Natural and Synthetic Autunite in the Presence of Aqueous Bicarbonate Ions

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

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn M.

2013-08-02

Bicarbonate is one of the most significant components within the uranium geochemical cycle. In aqueous solutions, bicarbonate forms strong complexes with uranium. As such, aqueous bicarbonate may significantly increase the rate of uranium release from uranium minerals. Quantifying the relationship of aqueous bicarbonate concentration to the rate of uranium release during dissolution is critical to understanding the long-term fate of uranium within the environment. Single-pass flow-through (SPTF) experiments were conducted to estimate the rate of uranium release from Na meta-autunite as a function of bicarbonate (0.0005-0.003 M) under the pH range of 6-11 and a temperature range of 5-60oC. Consistentmore » with the results of previous investigation, the rate of uranium release exhibited minimal dependency on temperature; but were strongly dependent on pH. Increasing aqueous bicarbonate concentrations afforded comparable increases in the rate of release of uranium. Most notably under low pH conditions the aqueous bicarbonate resulted in up to 370 fold increases in the rate of uranium release in relative to the rate of uranium release in the absence of bicarbonate. However, the effect of aqueous bicarbonate on the release of uranium was significantly less under higher pH conditions. It is postulated that at high pH values, surface sites are saturated with carbonate, thus the addition of more bicarbonate would have less effect on uranium release.« less

Rapid Dissolution of Soluble Uranyl Phases in Arid, Mine-Impacted Catchments near Church Rock, NM

PubMed Central

DELEMOS, JAMIE L.; BOSTICK, BENJAMIN C.; QUICKSALL, ANDREW N.; LANDIS, JOSHUA D.; GEORGE, CHRISTINE C.; SLAGOWSKI, NAOMI L.; ROCK, TOMMY; BRUGGE, DOUG; LEWIS, JOHNNYE; DURANT, JOHN L.

2008-01-01

We tested the hypothesis that runoff of uranium-bearing particles from mining waste disposal areas was a significant mechanism for redistribution of uranium in the northeastern part of the Upper Puerco River watershed (New Mexico). However, our results were not consistent with this hypothesis. Analysis of >100 sediment and suspended sediment samples collected adjacent to and downstream from uranium source areas indicated that uranium levels in the majority of the samples were not elevated above background. Samples collected within 50 m of a known waste disposal site were subjected to detailed geochemical characterization. Uranium in these samples was found to be highly soluble; treatment with synthetic pore water for 24 h caused dissolution of 10–50% of total uranium in the samples. Equilibrium uranium concentrations in pore water were >4.0 mg/L and were sustained in repeated wetting events, effectively depleting soluble uranium from the solid phase. The dissolution rate of uranium appeared to be controlled by solid-phase diffusion of uranium from within uranium-bearing mineral particles. X-ray adsorption spectroscopy indicated the presence of a soluble uranyl silicate, and possibly a uranyl phosphate. These phases were exhausted in transported sediment suggesting that uranium was readily mobilized from sediments in the Upper Puerco watershed and transported in the dissolved load. These results could have significance for uranium risk assessment as well as mining waste management and cleanup efforts. PMID:18589950

Urinary excretion of uranium in adult inhabitants of the Czech Republic.

PubMed

Malátová, Irena; Bečková, Věra; Kotík, Lukáš

2016-02-01

The main aim of this study was to determine and evaluate urinary excretion of uranium in the general public of the Czech Republic. This value should serve as a baseline for distinguishing possible increase in uranium content in population living near legacy sites of mining and processing uranium ores and also to help to distinguish the proportion of the uranium content in urine among uranium miners resulting from inhaled dust. The geometric mean of the uranium concentration in urine of 74 inhabitants of the Czech Republic was 0.091 mBq/L (7.4 ng/L) with the 95% confidence interval 0.071-0.12 mBq/L (5.7-9.6 ng/L) respectively. The geometric mean of the daily excretion was 0.15 mBq/d (12.4 ng/d) with the 95% confidence interval 0.12-0.20 mBq/d (9.5-16.1 ng/d) respectively. Despite the legacy of uranium mines and plants processing uranium ore in the Czech Republic, the levels of uranium in urine and therefore, also human body content of uranium, is similar to other countries, esp. Germany, Slovenia and USA. Significant difference in the daily urinary excretion of uranium was found between individuals using public supply and private water wells as a source of drinking water. Age dependence of daily urinary excretion of uranium was not found. Mean values and their range are comparable to other countries, esp. Germany, Slovenia and USA. Copyright © 2015 Elsevier Ltd. All rights reserved.

Uranium fate in wetland mesocosms: Effects of plants at two iron loadings with different pH values

EPA Science Inventory

Small-scale continuous flow wetland mesocosms (~0.8 L) were used to evaluate how plant roots under different iron loadings affect uranium (U) mobility. When significant concentrations of ferrous iron (Fe) were present at circumneutral pH values, U concentrations in root exposed ...

Zeolite-clay mineral zonation of volcaniclastic sediments within the McDermitt caldera complex of Nevada and Oregon

USGS Publications Warehouse

Glanzman, Richard K.; Rytuba, James J.

1979-01-01

Volcaniclastic sediments deposited in the moat of the collapsed McDermitt caldera complex have been altered chiefly to zeolites and potassium feldspar. The original rhyolitic and peralkaline ash-flow tuffs are included in conglomerates at the caldera rims and grade into a lacustrine series near the center of the collapse. The tuffs show a lateral zeolitic alteration from almost fresh glass to clinoptilolite, clinoptilolite-mordenite, and erionite; to analcime-potassium feldspar; and finally to potassium feldspar. Vertical zonation is in approximately the same order. Clay minerals in associated mudstones, on the other hand, show little lateral variation but a distinct vertical zonation, having a basal dioctahedral smectite, a medial trioctahedral smectite, and an upper dioctahedral smectite. The medial trioctahedral smectite is enriched in lithium (as much as 6,800 ppm Li). Hydrothermal alteration of the volcaniclastic sediments, forming both mercury and uranium deposits, caused a distinct zeolite and clay-mineral zonation within the general lateral zonation. The center of alteration is generally potassium feldspar, commonly associated with alunite. Potassium feldspar grades laterally and vertically to either clinoptilolite or clinoptilolite-mordenite, generally associated with gypsum. This zone then grades vertically and laterally into fresh glass. The clay minerals are a dioctahedral smectite, a mixed-layer clay mineral, and a 7-A clay mineral. The mixed-layer and 7-A clay minerals are associated with the potassium feldspar-alunite zone of alteration, and the dioctahedral smectite is associated with clinoptilolite. This mineralogical zonation may be an exploration guide for mercury and uranium mineralization in the caldera complex environment.

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

Campbell, Sam; Dam, Wiliam

In 2012, the U.S.Department of Energy (DOE) began reassessing the former Riverton, Wyoming, Processing Site area for potential contaminant sources impacting groundwater. A flood in 2010 along the Little Wind River resulted in increases in groundwater contamination (DOE 2013).This investigation is a small part of continued efforts by DOE and other stakeholders to update human health and ecological risk assessments, to make a comprehensive examination of all exposure pathways to ensure that the site remains protective through established institutional controls. During field inspections at the Riverton Site in 2013, a white evaporitic mineral deposit was identified along the bank ofmore » the Little Wind River within the discharge zone of the groundwater contamination plume. In December 2013, Savannah River National Laboratory (SRNL) personnel collected a sample for analysis by X-ray fluorescence (Figure 1 shows the type of material sampled). The sample had a uranium concentration of approximately 64 to 73 parts per million. Although the uranium in this mineral deposit is within the expected range for evaporatic minerals in the western United States (SRNL 2014), DOE determined that additional assessment of the mineral deposit was warranted. In response to the initial collection and analysis of a sample of the mineral deposit, DOE developed a work plan (Work Plan to Sample Mineral Deposits Along the Little Wind River, Riverton, Wyoming, Processing Site [DOE 2014]) to further define the extent of these mineral deposits and the concentration of the associated contaminants (Appendix A). The work plan addressed field reconnaissance, mapping, sampling, and the assessment of risk associated with the mineral deposits adjacent to the Little Wind River.« less

Uranium(IV) adsorption by natural organic matter in anoxic sediments

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

Bone, Sharon E.; Dynes, James J.; Cliff, John

Uranium is an important carbon-free fuel source and environmental contaminant that accumulates in the tetravalent state, U(IV), in anoxic sediments, such as ore deposits, marine basins, and contaminated aquifers. However, little is known about the speciation of U(IV) in low-temperature geochemical environments, inhibiting the development of a conceptual model of U behavior. Until recently, U(IV) was assumed to exist predominantly as the sparingly soluble mineral uraninite (UO 2+x) in anoxic sediments; however, studies now show that this is not often the case. Yet a model of U(IV) speciation in the absence of mineral formation under field-relevant conditions has not yetmore » been developed. Uranium(IV) speciation controls its reactivity, particularly its susceptibility to oxidative mobilization, impacting its distribution and toxicity. Here we show adsorption to organic carbon and organic carbon-coated clays dominate U(IV) speciation in an organic-rich natural substrate under field-relevant conditions. Whereas previous research assumed that U(IV) speciation is dictated by the mode of reduction (i.e., whether reduction is mediated by microbes or by inorganic reductants), our results demonstrate that mineral formation can be diminished in favor of adsorption, regardless of reduction pathway. Projections of U transport and bioavailability, and thus its threat to human and ecosystem health, must consider U(IV) adsorption to organic matter within the sediment environment.« less

Uranium(IV) adsorption by natural organic matter in anoxic sediments

DOE PAGES

Bone, Sharon E.; Dynes, James J.; Cliff, John; ...

2017-01-09

Uranium is an important carbon-free fuel source and environmental contaminant that accumulates in the tetravalent state, U(IV), in anoxic sediments, such as ore deposits, marine basins, and contaminated aquifers. However, little is known about the speciation of U(IV) in low-temperature geochemical environments, inhibiting the development of a conceptual model of U behavior. Until recently, U(IV) was assumed to exist predominantly as the sparingly soluble mineral uraninite (UO 2+x) in anoxic sediments; however, studies now show that this is not often the case. Yet a model of U(IV) speciation in the absence of mineral formation under field-relevant conditions has not yetmore » been developed. Uranium(IV) speciation controls its reactivity, particularly its susceptibility to oxidative mobilization, impacting its distribution and toxicity. Here we show adsorption to organic carbon and organic carbon-coated clays dominate U(IV) speciation in an organic-rich natural substrate under field-relevant conditions. Whereas previous research assumed that U(IV) speciation is dictated by the mode of reduction (i.e., whether reduction is mediated by microbes or by inorganic reductants), our results demonstrate that mineral formation can be diminished in favor of adsorption, regardless of reduction pathway. Projections of U transport and bioavailability, and thus its threat to human and ecosystem health, must consider U(IV) adsorption to organic matter within the sediment environment.« less

Implications of modelled radioactivity measurements along coastal Odisha, Eastern India for heavy mineral resources

NASA Astrophysics Data System (ADS)

Ghosal, S.; Agrahari, S.; Guin, R.; Sengupta, D.

2017-01-01

A radioelemental assemblage assessment of two beaches of Odisha is performed for the first time. The radiation is measured in two ways, both on field with the help of a hand held environmental survey meter and in the laboratory, where the concentrations of radionuclide's 238U, 232Th and 4K have been determined with the help of High Purity Germanium detector (HPGe). Mineralogical analysis of selected samples has been performed with the help of X-Ray Fluorescence Spectrometry (XRF). A marked difference between the concentration of Uranium (274 Bq kg-1) and Thorium (2489 Bq kg-1) is observed and discussed based on the geology of the area. The placer deposits showing an enrichment of thorium can be an important source of nuclear fuel for the thorium based nuclear reactors. The ratio of thorium and uranium concentrations gives us an idea about the coastal processes associated with the beach. Statistical analysis of the data shows a positive correlation between 238U and 232Th and a strong negative correlation is indicated between 4 K and 238U, 232Th. A cross plot between the equivalent thorium and the equivalent uranium and the equivalent thorium and potassium, represents the nature of deposition and its association with the heavy mineral along with the radioactive elements. Heavy minerals exhibit an increasing trend towards Northeast-Southwest along the south eastern coast of India.

Uranium mobility and accumulation along the Rio Paguate, Jackpile Mine in Laguna Pueblo, NM.

PubMed

Blake, Johanna M; De Vore, Cherie L; Avasarala, Sumant; Ali, Abdul-Mehdi; Roldan, Claudia; Bowers, Fenton; Spilde, Michael N; Artyushkova, Kateryna; Kirk, Matthew F; Peterson, Eric; Rodriguez-Freire, Lucia; Cerrato, José M

2017-04-19

The mobility and accumulation of uranium (U) along the Rio Paguate, adjacent to the Jackpile Mine, in Laguna Pueblo, New Mexico was investigated using aqueous chemistry, electron microprobe, X-ray diffraction and spectroscopy analyses. Given that it is not common to identify elevated concentrations of U in surface water sources, the Rio Paguate is a unique site that concerns the Laguna Pueblo community. This study aims to better understand the solid chemistry of abandoned mine waste sediments from the Jackpile Mine and identify key hydrogeological and geochemical processes that affect the fate of U along the Rio Paguate. Solid analyses using X-ray fluorescence determined that sediments located in the Jackpile Mine contain ranges of 320 to 9200 mg kg -1 U. The presence of coffinite, a U(iv)-bearing mineral, was identified by X-ray diffraction analyses in abandoned mine waste solids exposed to several decades of weathering and oxidation. The dissolution of these U-bearing minerals from abandoned mine wastes could contribute to U mobility during rain events. The U concentration in surface waters sampled closest to mine wastes are highest during the southwestern monsoon season. Samples collected from September 2014 to August 2016 showed higher U concentrations in surface water adjacent to the Jackpile Mine (35.3 to 772 μg L -1 ) compared with those at a wetland 4.5 kilometers downstream of the mine (5.77 to 110 μg L -1 ). Sediments co-located in the stream bed and bank along the reach between the mine and wetland had low U concentrations (range 1-5 mg kg -1 ) compared to concentrations in wetland sediments with higher organic matter (14-15%) and U concentrations (2-21 mg kg -1 ). Approximately 10% of the total U in wetland sediments was amenable to complexation with 1 mM sodium bicarbonate in batch experiments; a decrease of U concentration in solution was observed over time in these experiments likely due to re-association with sediments in the reactor. The findings from this study provide new insights about how hydrologic events may affect the reactivity of U present in mine waste solids exposed to surface oxidizing conditions, and the influence of organic-rich sediments on U accumulation in the Rio Paguate.

Patch testing with uranyl acetate in veterans exposed to depleted uranium during the 1991 Gulf war and the Iraqi conflict.

PubMed

Shvartsbeyn, Marianna; Tuchinda, Papapit; Gaitens, Joanna; Squibb, Katherine S; McDiarmid, Melissa A; Gaspari, Anthony A

2011-01-01

The Depleted Uranium Follow-Up Program is a clinical surveillance program run by the Baltimore Veterans Affairs Medical Center since 1993 for veterans of the Gulf and Iraqi wars who were exposed to depleted uranium (DU) as a result of "friendly-fire" incidents. In 2009, 40 veterans from this cohort were screened for skin reactivity to metals by patch-testing with extended metal series and uranyl acetate (0.25%, 2.5%, and 25%). A control arm comprised 46 patients without any known occupational exposures to DU who were seen at the University of Maryland Dermatology Clinic for evaluation of allergic contact dermatitis. Excluding irritant reactions, no patch-test reactions to uranyl acetate were observed in the participants. Irritant reactions to DU were more common in the clinic cohort, likely reflective of the demographic differences between the two arms of the study. Biologic monitoring of urine uranium concentrations in the DU program participants with 24-hour urine samples showed evidence of percutaneous uranium absorption from the skin patches. We conclude that dermatitis observed in a subset of the veterans was unrelated to their military DU exposure. Our data suggest that future studies of skin testing with uranyl acetate should utilize 0.25%, the least irritating concentration.

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; (5) Hydrous limonite precipitation and coprecipitated elements including uranium; (6) Rare earth elements deposited with detrital contamination (?); (7) Metal carbonate adsorption and precipitation. Economically recoverable minerals occurring at some localities in spring precipitates are ores of iron, manganese, sulfur, tungsten and barium and ornamental travertine. Continental radioactive mineral springs occur in areas of crustal thickening caused by overthrusting of crustal plates, and intrusion and metamorphism. Sedimentary rocks on the lower plate are trapped between the plates and form a zone of metamorphism. Connate waters, carbonate rocks and organic-carbon-bearing rocks react to extreme pressure and temperature to produce carbon dioxide, and steam. Fractures are forced open by gas and fluid pressures. Deep-circulating meteoric waters then come in contact with the reactive products, and a hydrothermal cell forms. When hot mineral-charged waters reach the surface they form the familiar hot mineral springs. Hot springs also occur in relation to igneous intrusive action or volcanism both of which may be products of the crustal plate overthrusting. Uranium and thorium in the sedimentary rocks undergoing metamorphism are sometimes mobilized, but mobilization is generally restricted to an acid hydrothermal environment; much is redeposited in favorable environments in the metamorphosed sediments. Radium and radon, which are highly mobile in both acid and alkaline aqueous media move upward into the hydrothermal cell and to the surface.

Summary of reconnaissance for radioactive deposits in Alaska, 1945-1954, and an appraisal of Alaskan uranium possibilities

USGS Publications Warehouse

Wedow, Helmuth

1956-01-01

In the period 1945-1954 over 100 investigations for radioactive source materials were made in Alaska. The nature of these investigations ranged from field examinations of individual prospects or the laboratory analysis of significantly radioactive samples submitted by prospectors to reconnaissance studies of large districts. In this period no deposits of uranium or thorium that would warrant commercial exploitation were discovered. The investigations, however, disclosed that radioactive materials occur in widely scattered areas of Alaska and in widely diverse environments. Many igneous rocks throughout Alaska are weakly radioactive because of uranium- and thorium-bearing accessory minerals, such as allanite, apatite, monazite, sphene, xenotime, and zircon; more rarely the radioactivity of these rocks is due to thorianite or thorite and their uranoan varieties. The felsic rocks, for example, granites and syenites, are generally more radioactive than the mafic igneous rocks. Pegmatites, locally, have also proved to be radioactive, but they have little commercial significance. No primary uranium oxide minerals have been found yet in Alaskan vein deposits, except, perhaps, for a mineral tentatively identified as pitchblende in the Hyder district of southeastern Alaska. However, certain occurrences of secondary uranium minerals, chiefly those of the uranite group, on the Seward Peninsula, in the Russian Mountains, and in the vicinity of Kodiak suggest that pitchblende-type ores may occur at depth beneath zones of alteration. Thorite-bearing veins have been discovered on Prince of Wales Island in southeastern Alaska. Although no deposits or carnotite-type minerals have been found in Alaska, several samples containing such minerals have been submitted by Alaskan prospectors. Efforts to locate the deposits from which these minerals were obtained have been unsuccessful, but review of available geologic data suggests that several Alaskan areas are potentially favorable for carnotite-type deposits. The chief of these areas is the Alaska Peninsula-Cook Inlet area which encompasses most of the reported occurrences of the prospectors' carnotite-type samples. Alaska is also potentially favorable for the occurrence of large bodies of the very low-grade uraniferous sedimentary rocks, such as phosphorites and black shales. This type of deposit, however, has not received much study because of the emphasis on the search for bonanza-type high-grade ores. Uraniferous phosphorites similar to those of Idaho, Montana, and Wyoming occur in northern Alaska on the north flank of the Brooks Range; black shales comparable to the uraniferous shales of the Chattanooga formation of southeastern United States have been noted along the Yukon River near the international boundary. Placer deposits in Alaska have some small potential for the production of the radioactive elements as byproducts of gold- and tin-placer mining. the placer area believed to have the relatively greatest potential in Alaska lies in the Kahiltna River valley where concentrates are known to contain such commercial minerals as ilmenite, cassiterite, platinum, and gold in addition to uranothorianite and monazite. The possibilities of the natural fluids--water and petroleum--have not yet been tested in Alaska to any great extent. Studies of fluids are in progress to determine whether they may be used to discover and define areas potentially favorable for the occurrence of uraniferous lodes.

Characterization of Uranium Contamination, Transport, and Remediation at Rocky Flats - Across Remediation into Post-Closure

NASA Astrophysics Data System (ADS)

Janecky, D. R.; Boylan, J.; Murrell, M. T.

2009-12-01

The Rocky Flats Site is a former nuclear weapons production facility approximately 16 miles northwest of Denver, Colorado. Built in 1952 and operated by the Atomic Energy Commission and then Department of Energy, the Site was remediated and closed in 2005, and is currently undergoing long-term surveillance and monitoring by the DOE Office of Legacy Management. Areas of contamination resulted from roughly fifty years of operation. Of greatest interest, surface soils were contaminated with plutonium, americium, and uranium; groundwater was contaminated with chlorinated solvents, uranium, and nitrates; and surface waters, as recipients of runoff and shallow groundwater discharge, have been contaminated by transport from both regimes. A region of economic mineralization that has been referred to as the Colorado Mineral Belt is nearby, and the Schwartzwalder uranium mine is approximately five miles upgradient of the Site. Background uranium concentrations are therefore elevated in many areas. Weapons-related activities included work with enriched and depleted uranium, contributing anthropogenic content to the environment. Using high-resolution isotopic analyses, Site-related contamination can be distinguished from natural uranium in water samples. This has been instrumental in defining remedy components, and long-term monitoring and surveillance strategies. Rocky Flats hydrology interlinks surface waters and shallow groundwater (which is very limited in volume and vertical and horizontal extent). Surface water transport pathways include several streams, constructed ponds, and facility surfaces. Shallow groundwater has no demonstrated connection to deep aquifers, and includes natural preferential pathways resulting primarily from porosity in the Rocky Flats alluvium, weathered bedrock, and discontinuous sandstones. In addition, building footings, drains, trenches, and remedial systems provide pathways for transport at the site. Removal of impermeable surfaces (buildings, roads, and so on) during the Site closure efforts resulted in major changes to surface and shallow groundwater flow. Consistent with previous documentation of uranium operations and contamination, only very small amounts of highly enriched uranium are found in a small number of water samples, generally from the former Solar Ponds complex and central Industrial Area. Depleted uranium is more widely distributed at the site, and water samples exhibit the full range of depleted plus natural uranium mixtures. However, one third of the samples are found to contain only natural uranium, and three quarters of the samples are found to contain more than 90% natural uranium - substantial fractions given that the focus of these analyses was on evaluating potentially contaminated waters. Following site closure, uranium concentrations have increased at some locations, particularly for surface water samples. Overall, isotopic ratios at individual locations have been relatively consistent, indicating that the increases in concentrations are due to decreases in dilution flow following removal of impermeable surfaces and buildings.

Quantification of kinetic rate law parameters for the dissolution of natural autunite in the presence of aqueous bicarbonate ions at high concentrations

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

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn

Uranium is a key contaminant of concern in the groundwater at 91 waste sites at 18 U.S. Department of Energy (DOE) facilities within the United States and is a potential source of groundwater contamination and a risk to human health and the environment through discharges to surface water. Dissolved inorganic carbon (bicarbonate/carbonate) has a high affinity for complexing with uranium that is present as sorbed or unique uranium-bearing mineral phases within the sedimentary matrix. This process can result in the formation of soluble uranyl carbonate aqueous species, which are mobile under circumneutral pH conditions. This study was conducted to quantifymore » the rate of release of uranium from the autunite mineral, (Ca[(UO 2)(PO 4)] 2∙3H 2O), that was formed during polyphosphate injection to remediate uranium; the dissolution of uranium was studied as a function of the aqueous bicarbonate concentration, ranging from 25 to 100 mM. Experiments were carried out in the pH range from 7 to 11 in the temperature range of 23-90°C via single-pass flow-through testing. Consistent with the results of previous studies (Gudavalli et al., 2013 a, b), the rate of uranium release from autunite exhibited minimal dependency on temperature, but was strongly dependent on pH and increasing concentrations of bicarbonate in the solution. Data obtained during these experiments were compared with results of previous experiments conducted using a low-concentration range of bicarbonate solutions (0.5-3.0 mM). An 8- to 30 fold increase in the rate of uranium release was observed in the presence of high bicarbonate concentrations at pH 7-8 compared to low bicarbonate values, while at pH 9-11, there was only a 5-fold increase in uranium rate of release with an increase in bicarbonate concentrations. The rate of uranium release was calculated to be between 5.18 x 10 -8 and 1.69 x 10 -7 mol m -2 s -1. The activation energy values at high and low bicarbonate concentrations were similar, with ratio values in the range of 0.6-1.0.« less

Quantification of kinetic rate law parameters for the dissolution of natural autunite in the presence of aqueous bicarbonate ions at high concentrations.

PubMed

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn

2018-05-02

Uranium is a key contaminant of concern in the groundwater at U.S. Department of Energy (DOE) facilities within the United States and is a potential source of groundwater contamination and a risk to human health and the environment through discharges to surface water. Dissolved inorganic carbon (bicarbonate/carbonate) has a high affinity for complexing with uranium that is present as sorbed or unique uranium-bearing mineral phases within the sedimentary matrix. This process can result in the formation of soluble uranyl carbonate aqueous species, which are mobile under circumneutral pH conditions. This study was conducted to quantify the rate of release of uranium from the autunite mineral, (Ca[(UO 2 )(PO 4 )] 2 •3H 2 O), that was formed during polyphosphate injection to remediate uranium; the dissolution of uranium was studied as a function of the aqueous bicarbonate concentration, ranging from 25 to 100 mM. Experiments were carried out in the pH range from 7 to 11 in the temperature range of 23-90 °C via single-pass flow-through testing. Consistent with the results of previous studies (Gudavalli et al., 2013a, 2013b), the rate of uranium release from autunite exhibited minimal dependency on temperature, but was strongly dependent on pH and increasing concentrations of bicarbonate in the solution. Data obtained during these experiments were compared with results of previous experiments conducted using a low-concentration range of bicarbonate solutions (0.5-3.0 mM). An 8- to 30-fold increase in the rate of uranium release was observed in the presence of high bicarbonate concentrations at pH 7-8 compared to low bicarbonate values, while at pH 9-11, there was only a 5-fold increase in uranium rate of release with an increase in bicarbonate concentrations. The rate of uranium release was calculated to be between 5.18 × 10 -8 and 1.69 × 10 -7  mol m -2 s -1 . The activation energy values at high and low bicarbonate concentrations were similar, with ratio values in the range of 0.6-1.0. Copyright © 2018 Elsevier Ltd. All rights reserved.

Aerial radiometric and magnetic reconnaissance survey of portions of Arizona, Idaho, Montana, New Mexico, South Dakota and Washington. Volume 2-F. Lewistown Quadrangle. Final report

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

Not Available

1979-06-01

Results of a high-sensitivity, aerial, gamma-ray spectrometer and magnetometer survey of the Lewistown Quadrangle, Montana, are presented. Instrumentation and methods are described in Volume 1 of this final report. Statistical and geological analysis of the radiometric data revealed 58 uranium anomalies worthy of field-checking as possible prospects. One anomaly may be associated with the Cambrian Flathead Quartzite that may contain deposits similar to the Blind River and Rand uranium deposits. Three anomalies may be indicative of sandstone-type deposits in Jurassic rocks, particularly the Morrison Formation, which hosts uranium mineralization elsewhere. One of the latter anomalies is also related to rocksmore » of the Mississippian Madison Group, and this suggests the possible presence of uranium in limestones of the Mission Canyon Formation. There are 45 anomalies related to the Cretaceous rocks. Lignite in the Hell Creek and Judith River formations and Eagle Sandstone may have caused the formation of 22 epigenetic uranium deposits. Many anomalies occur in the Bearpaw Shale and Claggett Formation. However, only five are considered significant of the remainder are expected to be caused by large amounts of radioactive bentonite or bentonitic shale. Two other Cretaceous units that may host sandstone-type deposits are the Colorado Shale and Kootenai Formation that register 16 and two anomalies respectively. Only one anomaly pertains to Tertiary rocks, and it may be indicative of vein-type deposits in the intrusives of the Judith Mountains. These rocks may also act as source rocks for deposits surrounding the Judith Mountains. Eight anomalies related only to Quaternary units may be demonstrative of uranium-rich source rocks that could host uranium mineralization.Several anomalies are located close to oil fields and may have been cause by radium-rich oil-field brines.« less

Incorporation of Uranium: II. Distribution of Uranium Absorbed through the Lungs and the Skin

PubMed Central

Walinder, G.; Fries, B.; Billaudelle, U.

1967-01-01

In experiments on mice, rabbits, and piglets the distribution of uranium was studied at different times after exposure. Uranium was administered by inhalation (mice) and through the skin (rabbits and piglets). These investigations show that the uptakes of uranium in different organs of the three species are highly dependent on the amounts administered. There seems to be a saturation effect in the spleen and bone tissue whenever the uranium concentration in the blood exceeds a certain level. The effect in the kidney is completely different. If, in a series of animals, the quantity of uranium is continuously increased, the uptakes by the kidneys increase more rapidly than the quantities administered. This observation seems to be consistent with the toxic effects of uranium on the capillary system in the renal cortex. Polyphloretin phosphate, a compound which reduces permeability, was investigated with respect to its effect on the uptake of uranium deposited in skin wounds in rabbits and piglets. It significantly reduced the absorption of uranium, even from depots in deep wounds. The findings are discussed with reference to the routine screening of persons exposed to uranium at AB Atomenergi. Images PMID:6073090

SELKIRK ROADLESS AREA, IDAHO.

USGS Publications Warehouse

Miller, Fred K.; Benham, John R.

1984-01-01

On the basis of mineral-resource surveys the Selkirk Roadless Area, Idaho has little promise for the occurrence of mineral or energy resources. Molybdenum, lead, uranium, thorium, chromium, tungsten, zirconium, and several rare-earth elements have been detected in panned concentrates from samples of stream sediment, but no minerals containing the first five elements were found in place, nor were any conditions conducive to their concentration found. Zirconium, thorium, and the rare earths occur in sparsely disseminated accessory minerals in granitic rocks and no resource potential is identified. There is no history of mining in the roadless area and there are no oil, gas, mineral, or geothermal leases or current claims.

PYRAMID ROADLESS AREA, CALIFORNIA.

USGS Publications Warehouse

Armstrong, Augustus K.; Scott, Douglas F.

1984-01-01

A geologic and mineral survey was conducted in the Pyramid Roadless Area, California. The area contains mineral showings, but no mineral-resource potential was identified during our studies. Three granodiorite samples on the west side of the roadless area contained weakly anomalous concentrations of uranium. Two samples of roof-pendant rocks, one metasedimentary rock and one metavolcanic rock, contain low concentrations of copper, and of copper and molybdenum, respectively. Although none was identified, the geologic terrane is permissive for mineral occurrences and large-scale, detailed geologic mapping of the areas of metasedimentary and metavolcanic roof pendants in the Pyramid Roadless Area could define a mineral-resource potential for tungsten and precious metals.

Effects of topographic features on postfire exposed mineral soil in small watersheds

Treesearch

Mariana Dobre; Joan Q. Wu; William J. Elliot; Ina S. Miller; Theresa B. Jain

2014-01-01

Exposed mineral soil is an immediate result of forest fires with direct relevance on surface runoff and soil erosion. The goal of this study was to determine which topographic features influence the distribution of exposed mineral soil following wildfire in forested watersheds. In a field investigation 2 months after a simulated wildfire, ground cover was measured and...

Three-dimensional inversion of magnetotelluric data for mineral exploration: An example from the McArthur River uranium deposit, Saskatchewan, Canada

NASA Astrophysics Data System (ADS)

Farquharson, Colin G.; Craven, James A.

2009-08-01

Shallow exploration targets are becoming scarce, meaning interest is turning towards deeper targets. The magnetotelluric method has the necessary depth capability, unlike many of the controlled-source electromagnetic prospecting techniques traditionally used. The geological setting of ore deposits is usually complex, requiring three-dimensional Earth models for their representation. An example of the applicability of three-dimensional inversion of magnetotelluric data to mineral exploration is presented here. Inversions of an audio-magnetotelluric data-set from the McArthur River uranium mine in the Athabasca Basin were carried out. A sub-set comprising data from eleven frequencies distributed over almost three decades was inverted. The form of the data used in the inversion was impedance. All four elements of the tensor were included. No decompositions of the data were done, nor rotation to a preferred strike direction, nor correction for static shifts. The inversions were successful: the observations were adequately reproduced and the main features in the conductivity model corresponded to known geological features. These included the graphitic basement fault along which the McArthur River uranium deposit is located.

Uranium-bearing lignite and its relation to the White River and Arikaree formations in northwestern South Dakota and adjacent states

USGS Publications Warehouse

Denson, N.M.; Bachman, G.O.; Zeller, H.D.

1954-01-01

the original White River and Arikaree sediments. Individual maps showing the extent, thickness, and variations in mineral content of the important deposits in the Table Mountain, Cave Hills, Slim Buttes, Lodgepole, and Medicine Pole areas are included. Conditions controlling the concentration of uranium are described and their application as guides to finding additional reserves by the presently held concepts are explained and illustrated.

Uranium association with iron-bearing phases in mill tailings from Gunnar, Canada.

PubMed

Othmane, Guillaume; Allard, Thierry; Morin, Guillaume; Sélo, Madeleine; Brest, Jessica; Llorens, Isabelle; Chen, Ning; Bargar, John R; Fayek, Mostafa; Calas, Georges

2013-11-19

The speciation of uranium was studied in the mill tailings of the Gunnar uranium mine (Saskatchewan, Canada), which operated in the 1950s and 1960s. The nature, quantification, and spatial distribution of uranium-bearing phases were investigated by chemical and mineralogical analyses, fission track mapping, electron microscopy, and X-ray absorption near edge structure (XANES) and extended X-ray absorption fine structure (EXAFS) spectroscopies at the U LIII-edge and Fe K-edge. In addition to uranium-containing phases from the ore, uranium is mostly associated with iron-bearing minerals in all tailing sites. XANES and EXAFS data and transmission electron microscopy analyses of the samples with the highest uranium concentrations (∼400-700 mg kg(-1) of U) demonstrate that uranium primarily occurs as monomeric uranyl ions (UO2(2+)), forming inner-sphere surface complexes bound to ferrihydrite (50-70% of the total U) and to a lesser extent to chlorite (30-40% of the total U). Thus, the stability and mobility of uranium at the Gunnar site are mainly influenced by sorption/desorption processes. In this context, acidic pH or alkaline pH with the presence of UO2(2+)- and/or Fe(3+)-complexing agents (e.g., carbonate) could potentially solubilize U in the tailings pore waters.

Laser fluorometric analysis of plants for uranium exploration

USGS Publications Warehouse

Harms, T.F.; Ward, F.N.; Erdman, J.A.

1981-01-01

A preliminary test of biogeochemical exploration for locating uranium occurrences in the Marfa Basin, Texas, was conducted in 1978. Only 6 of 74 plant samples (mostly catclaw mimosa, Mimosa biuncifera) contained uranium in amounts above the detection limit (0.4 ppm in the ash) of the conventional fluorometric method. The samples were then analyzed using a Scintrex UA-3 uranium analyzer* * Use of trade names in this paper is for descriptive purposes only and does not constitute endorsement by the U.S. Geological Survey. - an instrument designed for direct analysis of uranium in water, and which can be conveniently used in a mobile field laboratory. The detection limit for uranium in plant ash (0.05 ppm) by this method is almost an order of magnitude lower than with the fluorometric conventional method. Only 1 of the 74 samples contained uranium below the detection limit of the new method. Accuracy and precision were determined to be satisfactory. Samples of plants growing on mineralized soils and nonmineralized soils show a 15-fold difference in uranium content; whereas the soils themselves (analyzed by delayed neutron activation analysis) show only a 4-fold difference. The method involves acid digestion of ashed tissue, extraction of uranium into ethyl acetate, destruction of the ethyl acetate, dissolution of the residue in 0.005% nitric acid, and measurement. ?? 1981.

Reconnaissance for uraniferous rocks in northwestern Colorado, southwestern Wyoming, and northeastern Utah

USGS Publications Warehouse

Beroni, E.P.; McKeown, F.A.

1952-01-01

Previous discoveries and studies of radioactive lignites of Tertiary age in North Dakota, South Dakota, Montana, and Wyoming led the Geological Survey in 1950 to do reconnaissance in the Green River and Uinta Basin of Wyoming and Utah, where similar lignites were believed to be present. Because of the common association of uranium with copper deposits and the presence of such deposits in the Uinta Basin, several areas containing copper-uranium minerals were also examined. No deposits commercially exploitable under present conditions were found. Samples of coal from the Bear River formation at Sage, Wyo., assayed 0.004 to 0.013 percent uranium in the ash; in the old Uteland copper mine in Uinta County, Utah, 0.007 to 0.017 percent uranium; in a freshwater limestone, Duchesne County, Utah, as much as 0.019 percent uranium; and in the Mesaverde formation at the Snow and Bonniebell claims near Jensen, Uintah County, Utah, 0.003 to 0.090 percent uranium. Maps were made and samples were taken at the Skull Creek carnotite deposits in Moffat County, Colo. (0.006 to 0.16 percent uranium); at the Fair-U claims in Routt County, Colo. (0.002 to 0.040 percent uranium); and at the Lucky Strike claims near Kremmling in Grand County, Colo. (0.006 to 0.018 percent uranium).

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

Elevated radionuclide concentrations in heavy mineral-rich beach sands in the Cox's Bazar region, Bangladesh and related possible radiological effects.

PubMed

Zaman, Mashrur; Schubert, Michael; Antao, Sytle

2012-01-01

The study focuses on elevated levels of environmental radioactivity present in heavy mineral deposits located along a 120-km coastal section of Cox's Bazar on the eastern panhandle of Bangladesh. The deposits are situated in or at sand dunes located on the recent beach (foredune area) or in attached paleo-beach areas (backdune area). This study investigates activity concentrations in bulk beach sands (six representative samples) and in five mineral fractions separated from the beach sands in order to assess potential radio-ecological effects and the possible use of the mineral deposits as a source for uranium and thorium. The bulk beach sands and individual mineral fractions were analysed by gamma-ray spectroscopy. The activity concentrations of U-238, U-235, Th-232 and K-40 in the bulk beach sand samples were found to be considerably high and positively correlated to the concentration of heavy minerals in the sand. In the mineral fractions, the highest activity concentrations were found in the zircon fraction followed by garnet, rutile, ilmenite and magnetite. The determination of (i) the radium activity, (ii) several radiation hazard indices and (iii) adsorbed and effective gamma doses allowed to assess the related exposure of the environment and the local population to elevated radioactivity. It becomes evident from the present data that (1) if raw sands or mineral fractions mined in the study area are used for building purposes or industrial use, their activity concentrations have to be considered from a radio-ecological perspective and (2) if mining and processing of the minerals is being considered, uranium and thorium may become strategically significant by-products.

STUDY OF THE U/Th RATIO IN A THORITE FROM KIVU (BELGIAN CONGO) WITH REGARD TO ITS UTILIZATION IN THE PREPARATION OF THORIUM STANDARDS FOR GAMMA SPECTROMETRY (in French)

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

Poulaert, G.

1958-01-01

The uranium and thorium contents of a thorite from Kivu were determined. The very low U/Th ratio found makes this mineral a good standard for gamma spectrometry and fer all other direct radiometric measurements of thorium. The mineral was used in the preparation of ThB standards for the determination of the absolute age of rocks and minerals. (tr-auth)

NORTH ABSAROKA STUDY AREA, MONTANA.

USGS Publications Warehouse

Elliott, J.E.; Stotelmeyer, R.B.

1984-01-01

A mineral survey of the North Absaroka study area in Montana was conducted. The results of this survey indicate that parts of the area are extensively mineralized and that the area has potential for resources of gold, silver, copper, molybdenum, nickel, lead, zinc, platinum-group metals, uranium, iron, manganese, chromium, tungsten, and arsenic. Six areas of probable and substantiated mineral-resource potential were identified. The nature of the geologic terrain indicates that there is little likelihood for occurrence of oil, gas, coal, or geothermal resources.

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

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

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.more » 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 incubation with the appropriate uranium and bicarbonate concentration treatment. As expected, the cells started to reduce after day 41 due to the nutritional exhaustion of the media. Moreover, viable bacteria accounted for more than 94% in the presence of 10 mM bicarbonate. Experiments showed that despite differences between the G975 and the G968 bacterial strains resistance to U(VI), in the presence of bicarbonate ions they are able to dissolute uranium from autunite mineral at the same capacity. The effect of both bacterial strains on autunite dissolution is reduced as the concentration of bicarbonate increases while the increase in soluble U(VI) concentration induced by G968 and G975 is dwarfed, for larger [HCO{sub 3}{sup -}]. (authors)« less

Molecular Simulations of the Diffusion of Uranyl Carbonate Species in Nanosized Mineral Fractures

NASA Astrophysics Data System (ADS)

Kerisit, S.; Liu, C.

2010-12-01

Uranium is a major groundwater contaminant at uranium processing and mining sites as a result of intentional and accidental discharges of uranium-containing waste products into subsurface environments. Recent characterization has shown that uranium preferentially associates with intragrain and intra-aggregate domains in some of the uranium-contaminated sediments collected from the US Department of Energy Hanford Site [1, 2]. In these sediments, uranium existed as precipitated and/or adsorbed phases in grain micropores with nano- to microscale sizes. Desorption and diffusion characterization studies and continuum-scale modeling indicated that ion diffusion in the microfractures is a major mechanism that led to preferential uranium concentration in the microfracture regions and will control the future mobility of uranium in the subsurface sediments [1, 3-4]. However, the diffusion properties of uranyl species in the intragrain regions, especially at the solid-liquid interface, are still poorly understood. Therefore, a general aim of this work is to provide atomic-level insights into the contribution of microscopic surface effects to the slow diffusion process of uranyl species in porous media with nano- to microsized fractures. In this presentation, we will first present molecular dynamics (MD) simulations of feldspar-water interfaces to investigate their interfacial structure and dynamics and establish a theoretical framework for subsequent simulations of water and ion diffusion at these interfaces [5]. We will then report on MD simulations carried out to probe the effects of confinement and of the presence of the mineral surface on the diffusion of water and electrolyte ions in nanosized feldspar fractures [6]. Several properties of the mineral-water interface were varied, such as the fracture width, the ionic strength of the contacting solution, and the surface charge. Our calculations reveal a 2.0-2.5 nm interfacial region within which the diffusion properties of water and that of the electrolyte ions differ significantly from those in bulk aqueous solutions. We will then present MD simulations of the diffusion of a series of alkaline-earth uranyl carbonate species in aqueous solutions [7]. The MD simulations show that the alkaline-earth uranyl carbonate complexes have distinct water exchange dynamics, which could lead to different reactivities. Finally, we will present recent results on the diffusion and adsorption of uranyl carbonate species in intragrain micropores, modeled with the feldspar-water interfaces mentioned in the above, to help interpret the diffusion behavior of uranium in contaminated sediments. [1] Liu C. et al. Geochim. Cosmochim. Acta 68 4519 (2004) [2] McKinley J. P. et al. Geochim. Cosmochim. Acta 70 1873 (2006) [3] Liu C. et al. Water Resour. Res. 42 W12420 (2006) [4] Ilton E. S. et al. Environ. Sci. Technol. 42 1565 (2009) [5] Kerisit S. et al. Geochim. Cosmochim. Acta 72 1481 (2008) [6] Kerisit S. and Liu C. Environ. Sci. Technol. 43 777 (2009) [7] Kerisit S. and Liu C. Geochim. Cosmochim. Acta 74 4937 (2010)

Uranium metallogenesis of the peraluminous leucogranite from the Pontivy-Rostrenen magmatic complex (French Armorican Variscan belt): the result of long-term oxidized hydrothermal alteration during strike-slip deformation

NASA Astrophysics Data System (ADS)

Ballouard, C.; Poujol, M.; Mercadier, J.; Deloule, E.; Boulvais, P.; Baele, J. M.; Cuney, M.; Cathelineau, M.

2018-06-01

In the French Armorican Variscan belt, most of the economically significant hydrothermal U deposits are spatially associated with peraluminous leucogranites emplaced along the south Armorican shear zone (SASZ), a dextral lithospheric scale wrench fault that recorded ductile deformation from ca. 315 to 300 Ma. In the Pontivy-Rostrenen complex, a composite intrusion, the U mineralization is spatially associated with brittle structures related to deformation along the SASZ. In contrast to monzogranite and quartz monzodiorite (3 < U < 9 ppm; Th/U > 3), the leucogranite samples are characterized by highly variable U contents ( 3 to 27 ppm) and Th/U ratios ( 0.1 to 5) suggesting that the crystallization of magmatic uranium oxide in the more evolved facies was followed by uranium oxide leaching during hydrothermal alteration and/or surface weathering. U-Pb dating of uranium oxides from the deposits reveals that they mostly formed between ca. 300 and 270 Ma. In monzogranite and quartz monzodiorite, apatite grains display magmatic textures and provide U-Pb ages of ca. 315 Ma reflecting the time of emplacement of the intrusions. In contrast, apatite grains from the leucogranite display textural, geochemical, and geochronological evidences for interaction with U-rich oxidized hydrothermal fluids contemporaneously with U mineralizing events. From 300 to 270 Ma, infiltration of surface-derived oxidized fluids leached magmatic uranium oxide from fertile leucogranite and formed U deposits. This phenomenon was sustained by brittle deformation and by the persistence of thermal anomalies associated with U-rich granitic bodies.

Forms of uranium associated to silica in the environment of the Nopal deposit (Mexico)

NASA Astrophysics Data System (ADS)

Allard, T.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Calas, G.; Fayek, M.

2011-12-01

The understanding of the processes that control the transfers of uranium in the environment is necessary for the safety assessement of nuclear waste repositories. In particular, several poorly ordered phases (e.g. Fe oxihydroxides) are expected to play an important role in trapping uranium from surface waters. Among them, natural systems containing amorphous silica are poorly documented. A former study from the environment of the Peny mine (France) showed the importance of silica in uranium speciation [1]. The Nopal uranium deposit is located in volcanic tuff from tertiary period. It hosted several hydrothermal alteration episodes responsible for clay minerals formation. A primary uranium mineralisation occurred in a breccia pipe, consisting in uraninite, subsequently altered in secondary uranium minerals among which several silicates. Eventually, opal was formed and coated uranyl silicates such as uranophane and weeksite [2], [3]. Opals also contain minor amounts of uranium. The Nopal deposit is still considered as a natural analogue of high level nuclear waste repository located in volcanic tuff. It may be used to reveal the low temperature conditions of trapping of uranium in systems devoid of iron oxides such as silica-containing ones. The aim of this study is then to determine the uranium speciation, and its possible complexity, associated to these opals that represent a late trapping episode. It will provide insights ranging from the micrometer scale of electron microscopies to the molecular scale provided by fluorescence spectroscopy. Three samples of green or yellow opals have been analysed by a combination of complementary tools including scanning electron microscopy (SEM) on cross-sections, transmission electron microscopy (TEM) on focused ion beam (FIB) films, cathodoluminescence and time-resolved laser fluorescence spectroscopy (TRLFS). Uranium speciation was found to be complex. We first evidence U-bearing microparticles of beta-uranophane Ca[(UO2)(SiO3OH)]2(H2O)5 and apatite Ca5(PO4)3(OH,Cl,F) containing minor amounts of uranium. Uranophane was formed prior to opal and coated by it. However the major part of uranium is concentrated in Ca-U-enriched zones with a Ca:U ratio of 1:1 and displaying botryoidal features. The exact nature of Ca-U species in these zones was not specified but TEM, cathodoluminescence and TRLFS analyses suggest the presence of Cam-(UO2)m-(O/OH/H2O)n complexes adsorbed or incorporated in opal. These results will be discussed in terms of chemical conditions that prevailed during U incorporation and compared to other known U-Si environmental systems, including the Peny system (France). [1] Allard, T. et al. (1999) Chem. Geol., 158, 81-103 [2] Calas, G. et al. (2008) Terra Nova, 20, 206-212. [3] Schindler, M. et al. (2010) Geochim. Cosmochim. Ac, 74, 187-202.

Effect of natural uranium on the UMR-106 osteoblastic cell line: impairment of the autophagic process as an underlying mechanism of uranium toxicity.

PubMed

Pierrefite-Carle, Valérie; Santucci-Darmanin, Sabine; Breuil, Véronique; Gritsaenko, Tatiana; Vidaud, Claude; Creff, Gaelle; Solari, Pier Lorenzo; Pagnotta, Sophie; Al-Sahlanee, Rasha; Auwer, Christophe Den; Carle, Georges F

2017-04-01

Natural uranium (U), which is present in our environment, exerts a chemical toxicity, particularly in bone where it accumulates. Generally, U is found at oxidation state +VI in its oxocationic form [Formula: see text] in aqueous media. Although U(VI) has been reported to induce cell death in osteoblasts, the cells in charge of bone formation, the molecular mechanism for U(VI) effects in these cells remains poorly understood. The objective of our study was to explore U(VI) effect at doses ranging from 5 to 600 µM, on mineralization and autophagy induction in the UMR-106 model osteoblastic cell line and to determine U(VI) speciation after cellular uptake. Our results indicate that U(VI) affects mineralization function, even at subtoxic concentrations (<100 µM). The combination of thermodynamic modeling of U with EXAFS data in the culture medium and in the cells clearly indicates the biotransformation of U(VI) carbonate species into a meta-autunite phase upon uptake by osteoblasts. We next assessed U(VI) effect at 100 and 300 µM on autophagy, a survival process triggered by various stresses such as metal exposure. We observed that U(VI) was able to rapidly activate autophagy but an inhibition of the autophagic flux was observed after 24 h. Thus, our results indicate that U(VI) perturbs osteoblastic functions by reducing mineralization capacity. Our study identifies for the first time U(VI) in the form of meta-autunite in mammalian cells. In addition, U(VI)-mediated inhibition of the autophagic flux may be one of the underlying mechanisms leading to the decreased mineralization and the toxicity observed in osteoblasts.

The ultimate mineral processing challenge: Recovery of rare earths, phosphorus and uranium from Florida phosphatic clay

DOE PAGES

Zhang, Patrick; Liang, Haijun; Jin, Zhen; ...

2017-11-01

We report phosphate beneficiation in Florida generates more than one tonne of phosphatic clay, or slime, per tonne of phosphate rock produced. Since the start of the practice of large-scale washing and desliming for phosphate beneficiation, more than 2 Gt of slime has accumulated, containing approximately 600 Mt of phosphate rock, 600 kt of rare earth elements (REEs) and 80 million kilograms of uranium. The recovery of these valuable elements from the phosphatic clay is one of the most challenging endeavors in mineral processing, because the clay is extremely dilute, with an average solids concentration of 3 percent, and finemore » in size, with more than 50 percent having particle size smaller than 2 μm, and it contains nearly 50 percent clay minerals as well as large amounts of magnesium, iron and aluminum. With industry support and under funding from the Critical Materials Institute, the Florida Industrial and Phosphate Research Institute in conjunction with the Oak Ridge National Laboratory undertook the task to recover phosphorus, rare earths and uranium from Florida phosphatic clay. This paper presents the results from the preliminary testing of two approaches. The first approach involves three-stage cycloning using cyclones with diameters of 12.4 cm (5 in.), 5.08 cm (2 in.) and 2.54 cm (1 in.), respectively, to remove clay minerals followed by flotation and leaching. The second approach is a two-step leaching process. In the first step, selective leaching was conducted to remove magnesium, thus allowing the production of phosphoric acid suitable for the manufacture of diammonium phosphate (DAP) in the second leaching step. The results showed that multistage cycloning with small cyclones is necessary to remove clay minerals. Finally, selective leaching at about pH 3.2 using sulfuric acid was found to be effective for removing more than 80 percent of magnesium from the feed with minimal loss of phosphorus.« less

The ultimate mineral processing challenge: Recovery of rare earths, phosphorus and uranium from Florida phosphatic clay

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

Zhang, Patrick; Liang, Haijun; Jin, Zhen

We report phosphate beneficiation in Florida generates more than one tonne of phosphatic clay, or slime, per tonne of phosphate rock produced. Since the start of the practice of large-scale washing and desliming for phosphate beneficiation, more than 2 Gt of slime has accumulated, containing approximately 600 Mt of phosphate rock, 600 kt of rare earth elements (REEs) and 80 million kilograms of uranium. The recovery of these valuable elements from the phosphatic clay is one of the most challenging endeavors in mineral processing, because the clay is extremely dilute, with an average solids concentration of 3 percent, and finemore » in size, with more than 50 percent having particle size smaller than 2 μm, and it contains nearly 50 percent clay minerals as well as large amounts of magnesium, iron and aluminum. With industry support and under funding from the Critical Materials Institute, the Florida Industrial and Phosphate Research Institute in conjunction with the Oak Ridge National Laboratory undertook the task to recover phosphorus, rare earths and uranium from Florida phosphatic clay. This paper presents the results from the preliminary testing of two approaches. The first approach involves three-stage cycloning using cyclones with diameters of 12.4 cm (5 in.), 5.08 cm (2 in.) and 2.54 cm (1 in.), respectively, to remove clay minerals followed by flotation and leaching. The second approach is a two-step leaching process. In the first step, selective leaching was conducted to remove magnesium, thus allowing the production of phosphoric acid suitable for the manufacture of diammonium phosphate (DAP) in the second leaching step. The results showed that multistage cycloning with small cyclones is necessary to remove clay minerals. Finally, selective leaching at about pH 3.2 using sulfuric acid was found to be effective for removing more than 80 percent of magnesium from the feed with minimal loss of phosphorus.« less

30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

Code of Federal Regulations, 2011 CFR

2011-07-01

... 30 Mineral Resources 1 2011-07-01 2011-07-01 false Lightning arresters; ungrounded and exposed power conductors and telephone wires. 75.521 Section 75.521 Mineral Resources MINE SAFETY AND HEALTH... telephone wires. Each ungrounded, exposed power conductor and each ungrounded, exposed telephone wire that...

30 CFR 75.521 - Lightning arresters; ungrounded and exposed power conductors and telephone wires.

Code of Federal Regulations, 2010 CFR

2010-07-01

... 30 Mineral Resources 1 2010-07-01 2010-07-01 false Lightning arresters; ungrounded and exposed power conductors and telephone wires. 75.521 Section 75.521 Mineral Resources MINE SAFETY AND HEALTH... telephone wires. Each ungrounded, exposed power conductor and each ungrounded, exposed telephone wire that...

Health Risk Assessment of Embedded Depleted Uranium: Behavior, Physiology, Histology and Biokenetic Modeling

DTIC Science & Technology

1997-10-01

mg/in) (or in dogs or monkeys exposed for 5 years). Yet uranium concentrations in the kidney were as high as 1.1 tg U/g kidney wet weight in the rat...8.3 in the dog and 17.0 in the monkey), levels reported to cause acute renal toxicity (e.g., 2). Thus the chronic effects of uranium exposure remain...Anesthesia is induced with ketamine hydrochloride (80 mg/kg) in combination with xylazine hydrochloride (4 mg/kg), given i.p. Fragments are implanted within

Biogenic formation and growth of uraninite (UO₂).

PubMed

Lee, Seung Yeop; Baik, Min Hoon; Choi, Jong Won

2010-11-15

Biogenic UO₂ (uraninite) nanocrystals may be formed as a product of a microbial reduction process in uranium-enriched environments near the Earth's surface. We investigated the size, nanometer-scale structure, and aggregation state of UO₂ formed by iron-reducing bacterium, Shewanella putrefaciens CN32, from a uranium-rich solution. Characterization of biogenic UO₂ precipitates by high-resolution transmission electron microscopy (HRTEM) revealed that the UO₂ nanoparticles formed were highly aggregated by organic polymers. Nearly all of the nanocrystals were networked in more or less 100 nm diameter spherical aggregates that displayed some concentric UO₂ accumulation with heterogeneity. Interestingly, pure UO₂ nanocrystals were piled on one another at several positions via UO₂-UO₂ interactions, which seem to be intimately related to a specific step in the process of growing large single crystals. In the process, calcium that was easily complexed with aqueous uranium(VI) appeared not to be combined with bioreduced uranium(IV), probably due to its lower binding energy. However, when phosphate was added to the system, calcium was found to be easily associated with uranium(IV), forming a new uranium phase, ningyoite. These results will extend the limited knowledge of microbial uraniferous mineralization and may provide new insights into the fate of aqueous uranium complexes.

Geology of the Gateway quadrangle, Mesa county Colorado

USGS Publications Warehouse

Cater, Fred W.

1953-01-01

The Gateway quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Egnar quadrangle, Dolores and San Miguel counties, Colorado

USGS Publications Warehouse

Cater, Fred W.; Bush, A.L.; Bell, Henry

1954-01-01

The Egnar quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Hamm Canyon quadrangle, Colorado

USGS Publications Warehouse

Cater, Fred W.

1953-01-01

The Hamm Canyon quadrangle is on eof eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Davis Mesa quadrangle, Colorado

USGS Publications Warehouse

Cater, Fred W.; Bryner, Leonid

1953-01-01

The Davis Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as "Uruvan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Joe Davis Hill quadrangle, Dolores and San Miguel counties, Colorado

USGS Publications Warehouse

Cater, Fred W.; Bell, Henry

1953-01-01

The Joe Davis Hill quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by hih-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Gypsum Gap quadrangle, Colorado

USGS Publications Warehouse

Cater, Fred W.

1953-01-01

The Gypsum Gap quadrangle is one eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comparative study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through a arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The core consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Pine Mountain quadrangle, Mesa county, Colorado

USGS Publications Warehouse

Cater, Fred W.

1953-01-01

The Pine Mountain quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from Paleozoic to Quaternary. Over mush of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confines to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in sizer from irregular masses containing only a few ton of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Naturita NW quadrangle, Colorado

USGS Publications Warehouse

Cater, Fred W.; Vogel, J.D.

1953-01-01

The Naturita NW quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles were mapped by the U.S. Geological Survey on behalf of the U.S. Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear ro be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Calamity Mesa quadrangle, Mesa county, Colorado

USGS Publications Warehouse

Cater, Fred W.; Stager, Harold K.

1953-01-01

The Calamity Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks the range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Horse Range Mesa quadrangle, Colorado

USGS Publications Warehouse

Cater, Fred W.; Bush, A.L.; Bell, Henry; Withington, C.F.

1953-01-01

The Horse Range Mesa quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of the quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary strictures in sandstones of favorable composition.

Geology of Bull Canyon quadrangle, Montrose and San Miguel counties, Colorado

USGS Publications Warehouse

Cater, Fred W.

1953-01-01

The Bull Canyon quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite depots. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tones. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to be related to certain sedimentary structures in sandstones of favorable composition.

Geology of the Uravan quadrangle, Montrose county, Colorado

USGS Publications Warehouse

Cater, Fred W.; Butler, A.P.; McKay, E.J.; Boardman, Robert L.

1954-01-01

The Uravan quadrangle is one of eighteen 7 1/2-minute quadrangles covering the principal carnotite-producing area of the southwestern Colorado. The geology of these quadrangles was mapped by the U.S. Geological Survey for the Atomic Energy Commission as part of a comprehensive study of carnotite deposits. The rocks exposed in the eighteen quadrangles consist of crystalline rocks of pre-Cambrian age and sedimentary rocks that range in age from late Paleozoic to Quaternary. Over much of the area the sedimentary rocks are flat lying, but in places the rocks are disrupted by high-angle faults, and northwest-trending folds. Conspicuous among the folds are large anticlines having cores of intrusive salt and gypsum. Most of the carnotite deposits are confined to the Salt Wash sandstone member of the Jurassic Morrison formation. Within this sandstone, most of the deposits are spottily distributed through an arcuate zone known as the "Uravan Mineral Belt". Individual deposits range in size from irregular masses containing only a few tons of ore to large, tabular masses containing many thousands of tons. The ore consists largely of sandstone selectively impregnated and in part replaced by uranium and vanadium minerals. Most of the deposits appear to the related to certain sedimentary structures in sandstones of favorable composition.

Determination of the oxidation state of uranium in apatite and phosphorite deposits

USGS Publications Warehouse

Clarke, R.S.; Altschuler, Z.S.

1958-01-01

Geological and mineralogical evidence indicate that the uranium present in apatite may proxy for calcium in the mineral structure as U(IV). An experimental investigation was conducted and chemical evidence was obtained that establishes the presence of U(IV) in apatite. The following analytical procedure was developed for the determination of U(IV). Carbonatefluorapatite is dissolved in 1.5 M orthophosphoric acid at a temperature of 5??C or slightly below and fluorapatite is dissolved in cold 1.2 M hydrochloric acid (approximately 5??C) containing 1.5 g of hydroxylamine hydrochloride per 100 ml. Uranium(IV) is precipitated by cupferron using titanium as a carrier. The uranium in the precipitate is separated by use of the ethyl acetate extraction procedure and determined fluorimetrically. The validity and the limitations of the method have been established by spike experiments. ?? 1958.

Natural radioactivity in commercial granites extracted near old uranium mines: scientific, economic and social impact of disinformation.

NASA Astrophysics Data System (ADS)

Pereira, Dolores; Pereira, Alcides; Neves, Luis

2015-04-01

The study of radioactivity in natural stones is a subject of great interest from different points of view: scientific, social and economic. Several previous studies have demonstrated that the radioactivity is dependent, not only on the uranium content, but also on the structures, textures, minerals containing the uranium and degree of weathering of the natural stone. Villavieja granite is extracted in a village where uranium mining was an important activity during the 20th century. Today the mine is closed but the granite is still extracted. Incorrect information about natural radioactivity given to natural stone users, policy makers, construction managers and the general public has caused turmoil in the media for many years. This paper considers problems associated with the communication of reliable information, as well as uncertainties, on natural radioactivity to these audiences.

Aftermath of Uranium Ore Processing on Floodplains: Lasting Effects of Uranium on Soil and Microbes

NASA Astrophysics Data System (ADS)

Tang, H.; Boye, K.; Bargar, J.; Fendorf, S. E.

2016-12-01

A former uranium ore processing site located between the Wind River and the Little Wind River near the city of Riverton, Wyoming, has generated a uranium plume in the groundwater within the floodplain. Uranium is toxic and poses a threat to human health. Thus, controlling and containing the spread of uranium will benefit the human population. The primary source of uranium was removed from the processing site, but a uranium plume still exists in the groundwater. Uranium in its reduced form is relatively insoluble in water and therefore is retained in organic rich, anoxic layers in the subsurface. However, with the aid of microbes uranium becomes soluble in water which could expose people and the environment to this toxin, if it enters the groundwater and ultimately the river. In order to better understand the mechanisms controlling uranium behavior in the floodplains, we examined sediments from three sediment cores (soil surface to aquifer). We determined the soil elemental concentrations and measured microbial activity through the use of several instruments (e.g. Elemental Analyzer, X-ray Fluorescence, MicroResp System). Through the data collected, we aim to obtain a better understanding of how the interaction of geochemical factors and microbial metabolism affect uranium mobility. This knowledge will inform models used to predict uranium behavior in response to land use or climate change in floodplain environments.

Overview of Phosphate-Based Remediation Technologies At The Hanford Site, Richland Washington

NASA Astrophysics Data System (ADS)

Thompson, K. M.; Fruchter, J. S.

2009-12-01

Phosphate-based technologies have been tested to sequester strontium-90 and uranium at the Hanford Site, part of the U.S. Department of Energy's (DOE)nuclear weapons complex that encompasses approximately 586 square miles in southeast Washington State. The Columbia River flows through the site (Hanford Reach) where localized groundwater plumes upwell into the river. Efforts to reduce the flux of Sr-90 to the Columbia River from Hanford Site 100-N Area past practice liquid waste disposal sites have been underway since the early 1990s. Termination of all liquid discharges to the ground in 1993 was a major step toward meeting this goal. However, Sr 90 adsorbed onto sediment beneath liquid waste disposal sites, and onto sediment that extends beneath the near-shore riverbed, remains a continuing contaminant source for impacting groundwater and the Columbia River. Initial remediation efforts using a pump-and treat system proved to be ineffective as a long-term solution because of the geochemical characteristics of Sr-90. Following an evaluation of potential Sr-90 treatment technologies and their applicability under 100-N Area hydrogeologic conditions, the U.S. Department of Energy and the Washington State Department of Ecology agreed to evaluate apatite sequestration as the primary remedial technology, combined with a secondary polishing step utilizing phytoextraction if necessary. DOE is also evaluating the efficacy of using polyphosphate to reduce uranium concentrations in the groundwater with the goal of meeting drinking water standards (30 μg/L). 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. These remedial technologies are being developed by Pacific Northwest National Laboratory. CH2M Hill Plateau Remediation Company is implementing the technologies in the field, with support from the Laboratory. An overview of the technologies and results to date are presented.

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

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

NASA Astrophysics Data System (ADS)

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 pH 5 in the absence of HA due to low mobility of the colloids. At pH 9, U desorbed from mobile illite and the presence of illite decreased U transport. At pH 5, 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.

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.

Natural uranium impairs the differentiation and the resorbing function of osteoclasts.

PubMed

Gritsaenko, Tatiana; Pierrefite-Carle, Valérie; Lorivel, Thomas; Breuil, Véronique; Carle, Georges F; Santucci-Darmanin, Sabine

2017-04-01

Uranium is a naturally occurring radionuclide ubiquitously present in the environment. The skeleton is the main site of uranium long-term accumulation. While it has been shown that natural uranium is able to perturb bone metabolism through its chemical toxicity, its impact on bone resorption by osteoclasts has been poorly explored. Here, we examined for the first time in vitro effects of natural uranium on osteoclasts. The effects of uranium on the RAW 264.7 monocyte/macrophage mouse cell line and primary murine osteoclastic cells were characterized by biochemical, molecular and functional analyses. We observed a cytotoxicity effect of uranium on osteoclast precursors. Uranium concentrations in the μM range are able to inhibit osteoclast formation, mature osteoclast survival and mineral resorption but don't affect the expression of the osteoclast gene markers Nfatc1, Dc-stamp, Ctsk, Acp5, Atp6v0a3 or Atp6v0d2 in RAW 274.7 cells. Instead, we observed that uranium induces a dose-dependent accumulation of SQSTM1/p62 during osteoclastogenesis. We show here that uranium impairs osteoclast formation and function in vitro. The decrease in available precursor cells, as well as the reduced viability of mature osteoclasts appears to account for these effects of uranium. The SQSTM1/p62 level increase observed in response to uranium exposure is of particular interest since this protein is a known regulator of osteoclast formation. A tempting hypothesis discussed herein is that SQSTM1/p62 dysregulation contributes to uranium effects on osteoclastogenesis. We describe cellular and molecular effects of uranium that potentially affect bone homeostasis. Copyright © 2017 Elsevier B.V. All rights reserved.

High-Resolution Mineralogical Characterization and Biogeochemical Modeling of Uranium Reduction Pathways at the NABIR Field-Research Center

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

David R. Veblen; Chen Zhu; Lee Krumholz

The effectiveness and feasibility of bioremediation at the field scale cannot be fully assessed until the mechanisms of immobilization and U speciation in the solid matrix are resolved. However, characterization of the immobilized U and its valence states is extremely difficult, because microbially mediated mineral precipitates are generally nanometer (nm)-sized, poorly crystalline, or amorphous. We are developing combined field emission gun--scanning electron microscopy (FEG-SEM, at Indiana University) and FEG transmission electron microscopy (TEM, at Hopkins) to detect and isolate uranium containing phases; (1) method developments for TEM sample preparations and parallel electron energy loss spectroscopy (EELS) determination of uranium valence;more » and (2) to determine the speciation, fate, reactivity, valence states of immobilized uranium, using the state-of-the-art 300-kV, FEG-TEM. We have obtained preliminary results on contaminated sediments from Area 3 at the Oak Ridge Field Research Center (FRC). TEM results show that the sediments contain numerous minerals, including quartz, mica/clay (muscovite and/or illite), rutile, ilmenite, zircon, and an Al-Sr-Ce-Ca phosphate mineral, none of which contain uranium above the EDS detection limit. Substantial U (up to {approx}2 wt.%) is, however, clearly associated with two materials: (1) the Fe oxyhydroxide and (2) clots of a chemically complex material that is likely a mixture of several nm-scale phases. The Fe oxyhydroxide was identified as goethite from its polycrystalline SAED pattern and EDS analysis showing it to be very Fe-rich; the aggregate also displays one of several morphologies that are common for goethite. U is strongly sorbed to goethite in the FRC sediment, and the ubiquitous association with phosphorous suggests that complexes containing both U and P may play an important role in that sorption. Results from bulk analysis and SEM had previously demonstrated the association of U with Fe and thus suggested that U may be sorbed by Fe oxide or oxyhydroxide (Dr. Roh, image presented by David Watson). However, rigorous identification of the host minerals for U requires TEM results such as these involving imaging, electron diffraction, and spectroscopic analysis. An even higher concentration of U occurs in the chemically complex material noted above. These ''clots'' are high in Fe but also contain C, O, Mg, Al, Si, P, S, Cl, K, Ca, Mn, and U. This chemical complexity strongly suggests that they consist of aggregates of carbonate, silicate, phosphate, and sulfate phases, and TEM images also suggest that they may be intergrowths of numerous exceedingly small nanoparticles. EELS and EFTEM studies should be able to resolve these various components and identify precisely where the uranium is in these complex materials. From the results, it is clear that the FEG-SEM and FEG-TEM can readily detect uranium in the FRC samples. The FEG-SEM allows a wide field of view of the samples and can detect U-rich aggregates as small as 20-30 nm. The FEG-TEM can then focus on these aggregates and use SAED, EDS, EFTEM, and PEELS techniques to determine the valence states, structures, and compositional data for these aggregates. This research will provide a crucial component for a complete understanding of the efficacy of uranium bioremediation.« less

Uranium-bearing copper deposits in the Coyote district, Mora County, New Mexico

USGS Publications Warehouse

Zeller, H.D.; Baltz, Elmer Harold

1954-01-01

Uranium-bearing copper deposits occur in steeply dipping beds of the Sangre de Cristo formation of Pennsylvanian and Permian(?) age south of Coyote, Mora County, N. Mex. Mapping and sampling of these deposits indicate that they are found in lenticular carbonaceous zones in shales and arkosic sandstones. Samples from these zones contain as much as 0.067 percent uranium and average 3 percent copper. Metatyuyamunite is dissemihatedin some of the arkosic sandstone beds, and uraninite is present in some of the copper sulfide nodules occurring in the shale. These sulfide nodules are composed principally of chalcocite but include some bornite, covellite, pyrite, and malachite. Most of the samples were collected near the surface from the weathered zone. The copper and uranium were probably deposited with the sediments and concentrated into zones during compaction and lithification. Carbonaceous material in the Sangre de Cristo formation provided the environment that precipitated uranium and copper from mineral-charged connate waters forced from the clayey sediments.

Determination of uranium and thorium in materials associated with real time electronic solar neutrino detectors

NASA Astrophysics Data System (ADS)

Fassett, J. D.; Kelly, W. R.

1992-07-01

The application of isotope dilution thermal ionization mass spectrometry to the determination of both uranium and thorium in four different target materials used or proposed for electronic neutrino detectors is described. Isotope dilution analysis is done using highly enriched 233U and 230Th separated isotopes. Sensitivity of the technique is such that sub-picogram amounts of material are readily measured. The overall limit to measurement is caused by contamination of these elements during the measurement process. Uranium is more easily measured than thorium because both the instrumental sensitivity is higher and contamination is better controlled. The materials analyzed were light and heavy water, pseudocumene, and mineral oil.

Lichen physiology and cell biology

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

Brown, D.H.

1985-01-01

This book presents information on topics relating to mineral element accumulation in bog lichens, nitrogen losses from diazotrophic lichens, influence of automobile exhaust and lead on the oxygen exchange of lichens, temporal variation in lichen element levels, and lead and uranium uptake by lichens. Other topics include the architecture of the concentric bodies in the mycobiont of Peltigera praetextata; multiple enzyme forms in lichens, photosynthesis, water relations multiple enzyme forms in lichens, photosynthesis, water relations and thallus structure of strictaceae lichens; and aspects of carbohydrate metabolism in lichens. The distribution of uranium and companion elements in lichen heath associated withmore » undisturbed uranium deposits in the Canadian Arctic is also discussed.« less

Paragenesis and Geochronology of the Nopal I Uranium Deposit, Mexico

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

M. Fayek; M. Ren

2007-02-14

Uranium deposits can, by analogy, provide important information on the long-term performance of radioactive waste forms and radioactive waste repositories. Their complex mineralogy and variable elemental and isotopic compositions can provide important information, provided that analyses are obtained on the scale of several micrometers. Here, we present a structural model of the Nopal I deposit as well as petrography at the nanoscale coupled with preliminary U-Th-Pb ages and O isotopic compositions of uranium-rich minerals obtained by Secondary Ion Mass Spectrometry (SIMS). This multi-technique approach promises to provide ''natural system'' data on the corrosion rate of uraninite, the natural analogue ofmore » spent nuclear fuel.« less

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

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

Spirakis, C.S.; Condit, C.D.

1975-01-01

LANDSAT-1 (ERTS-1) 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-1 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.

Leukaemia mortality and low-dose ionising radiation in the WISMUT uranium miner cohort (1946-2013).

PubMed

Kreuzer, Michaela; Sobotzki, Christina; Fenske, Nora; Marsh, James W; Schnelzer, Maria

2017-03-01

To examine the risk of death from leukaemia in relation to occupational chronic low-level external and internal radiation exposure in a cohort of 58 972 former German uranium miners with mortality follow-up from 1946 to 2013. The red bone marrow (RBM) dose from low-linear energy transfer (LET) (mainly external γ-radiation) and high-LET (mainly radon gas) radiation was estimated based on a job-exposure matrix and biokinetic/dosimetric models. Linear excess relative risks (ERR) and 95% CIs were estimated via Poisson regression for chronic lymphatic leukaemia (CLL) and non-CLL. The mean cumulative low-LET and high-LET RBM doses among the 86% radiation-exposed workers were 48 and 9 mGy, respectively. There was a positive non-significant dose-response for mortality from non-CLL (n=120) in relation to low-LET (ERR/Gy=2.18; 95% CI -0.41 to 6.37) and high-LET radiation (ERR/Gy=16.65; 95% -1.13 to 46.75). A statistically significant excess was found for the subgroup chronic myeloid leukaemia (n=31) in relation to low-LET radiation (ERR/Gy=7.20; 95% CI 0.48 to 24.54) and the subgroup myeloid leukaemia (n=99) (ERR/Gy=26.02; 95% CI 2.55 to 68.99) for high-LET radiation. The ERR/Gy tended to be about five to ten times higher for high-LET versus low-LET radiation; however, the CIs largely overlapped. Results indicate no association of death from CLL (n=70) with either type of radiation. Our findings indicate an increased risk of death for specific subtypes from non-CLL in relation to chronic low-LET and high-LET radiation, but no such relation for CLL. Published by the BMJ Publishing Group Limited. For permission to use (where not already granted under a licence) please go to http://www.bmj.com/company/products-services/rights-and-licensing/.

Electron transfer at the cell-uranium interface in Geobacter spp.

PubMed

Reguera, Gemma

2012-12-01

The in situ stimulation of Fe(III) oxide reduction in the subsurface stimulates the growth of Geobacter spp. and the precipitation of U(VI) from groundwater. As with Fe(III) oxide reduction, the reduction of uranium by Geobacter spp. requires the expression of their conductive pili. The pili bind the soluble uranium and catalyse its extracellular reductive precipitation along the pili filaments as a mononuclear U(IV) complexed by carbon-containing ligands. Although most of the uranium is immobilized by the pili, some uranium deposits are also observed in discreet regions of the outer membrane, consistent with the participation of redox-active foci, presumably c-type cytochromes, in the extracellular reduction of uranium. It is unlikely that cytochromes released from the outer membrane could associate with the pili and contribute to the catalysis, because scanning tunnelling microscopy spectroscopy did not reveal any haem-specific electronic features in the pili, but, rather, showed topographic and electronic features intrinsic to the pilus shaft. Pili not only enhance the rate and extent of uranium reduction per cell, but also prevent the uranium from traversing the outer membrane and mineralizing the cell envelope. As a result, pili expression preserves the essential respiratory activities of the cell envelope and the cell's viability. Hence the results support a model in which the conductive pili function as the primary mechanism for the reduction of uranium and cellular protection in Geobacter spp.

Extraction of reduced alteration information based on Aster data: a case study of the Bashibulake uranium ore district

NASA Astrophysics Data System (ADS)

Ye, Fa-wang; Liu, De-chang

2008-12-01

Practices of sandstone-type uranium exploration in recent years in China indicate that the uranium mineralization alteration information is of great importance for selecting a new uranium target or prospecting in outer area of the known uranium ore district. Taking a case study of BASHIBULAKE uranium ore district, this paper mainly presents the technical minds and methods of extracting the reduced alteration information by oil and gas in BASHIBULAKE ore district using ASTER data. First, the regional geological setting and study status in BASHIBULAKE uranium ore district are introduced in brief. Then, the spectral characteristics of altered sandstone and un-altered sandstone in BASHIBULAKE ore district are analyzed deeply. Based on the spectral analysis, two technical minds to extract the remote sensing reduced alteration information are proposed, and the un-mixing method is introduced to process ASTER data to extract the reduced alteration information in BASHIBULAKE ore district. From the enhanced images, three remote sensing anomaly zones are discovered, and their geological and prospecting significances are further made sure by taking the advantages of multi-bands in SWIR of ASTER data. Finally, the distribution and intensity of the reduced alteration information in Cretaceous system and its relationship with the genesis of uranium deposit are discussed, the specific suggestions for uranium prospecting orientation in outer of BASHIBULAKE ore district are also proposed.

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 and marcasite). Also, long-term continuous leakage of radioactive daughters of 238 U (probably 222 Rn) has occurred on scales of from approximately 100 mu m approximately 10 cm. The isotopic composition of unsupported radiogenic Pb in pyrite-marcasite seems to depend on the mineralogical microenvironment of the grains, so that the radiogenic Pb in pyrite-marcasite intimately intermixed with pitchblende-coffinite tends to be deficient in 206 Pb, and the radiogenic Pb in pyrite-marcasite in gangue tends to have excess 206 Pb. These systematics probably reflect differences between the average distances of Pb and 222 Rn diffusion since the formation of the ores.

Phosphorus K-edge XANES spectroscopy of mineral standards

PubMed Central

Ingall, Ellery D.; Brandes, Jay A.; Diaz, Julia M.; de Jonge, Martin D.; Paterson, David; McNulty, Ian; Elliott, W. Crawford; Northrup, Paul

2011-01-01

Phosphorus K-edge X-ray absorption near-edge structure (XANES) spectroscopy was performed on phosphate mineral specimens including (a) twelve specimens from the apatite group covering a range of compositional variation and crystallinity; (b) six non-apatite calcium-rich phosphate minerals; (c) 15 aluminium-rich phosphate minerals; (d) ten phosphate minerals rich in either reduced iron or manganese; (e) four phosphate minerals rich in either oxidized iron or manganese; (f) eight phosphate minerals rich in either magnesium, copper, lead, zinc or rare-earth elements; and (g) four uranium phosphate minerals. The identity of all minerals examined in this study was independently confirmed using X-ray powder diffraction. Minerals were distinguished using XANES spectra with a combination of pre-edge features, edge position, peak shapes and post-edge features. Shared spectral features were observed in minerals with compositions dominated by the same specific cation. Analyses of apatite-group minerals indicate that XANES spectral patterns are not strongly affected by variations in composition and crystallinity typical of natural mineral specimens. PMID:21335905

Exogenous contamination of uranium in human scalp hair.

PubMed

Muikku, Maarit; Heikkinen, Tarja

2012-06-01

The use of human scalp hair as a bioindicator of occupational or environmental exposure has been the subject of some debate over the years. One problem is how to distinguish internal contamination from external contamination. In this study, possibility that elevated levels of natural uranium in human hair are partly due to the exogenously bound uranium from uranium-rich household water was tested. Hair samples from six adult volunteers were cut and then exposed externally to uranium by using washing water with highly elevated levels of natural uranium. After that, and before making the analysis using inductively coupled plasma mass spectrometry (ICP-MS), the samples were washed using two commonly used washing procedures in order to remove external contamination. No quantitative information was gained in the tests, but it was shown that the use of uranium-rich water when washing hair affects the uranium concentration in hair. Although the samples were cleaned according to widely used washing procedures before the analysis, the uranium concentrations in hair were about three orders of magnitude higher after the tests. The possibility of external contamination should be kept in mind, especially when considering hair as an excretion pathway for estimating internal dose.

Physico-Chemical Characteristics of Uraniferous Supergene Minerals; CARACTERISTIQUES PHYSICO-CHIMIQUES DES MINERAUX URANIFERES SUPERGENES

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

Semat, M.A.

1960-01-01

Transport and deposit conditions of uraniferous minerals are breifly described. The synthesis of crystallograpic, physical, optical, and thermal properties permits defining the main characteristics of this mineralogical group. Tables to facilicate identification of the supergene uranium minerals are given on investigation by anion and cation; system, cleavages, cell parameters, interplanar spacings, refractive indices, optical barings; classification by decreasing values of the most intense line of the powder diagram; diagram for the three higher interplanar spacings; and diagram of the refractive indices. (auth)

Quantification of Kinetic Rate Law Parameters of Uranium Release from Sodium Autunite as a Function of Aqueous Bicarbonate Concentrations

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

Gudavalli, Ravi; Katsenovich, Yelena; Wellman, Dawn M.

2013-09-05

ABSTRACT: Hydrogen carbonate is one of the most significant components within the uranium geochemical cycle. In aqueous solutions, hydrogen carbonate forms strong complexes with uranium. As such, aqueous bicarbonate may significantly increase the rate of uranium release from uranium minerals. Quantifying the relationship of aqueous hydrogen carbonate solutions to the rate of uranium release during dissolution is critical to understanding the long-term fate of uranium within the environment. Single-pass flow-through (SPTF) experiments were conducted to estimate the rate of uranium release from Na meta-autunite as a function of bicarbonate solutions (0.0005-0.003 M) under the pH range of 6-11 and temperaturesmore » of 5-60oC. Consistent with the results of previous investigation, the rate of uranium release from sodium autunite exhibited minimal dependency on temperature; but were strongly dependent on pH and increasing concentrations of bicarbonate solutions. Most notably at pH 7, the rate of uranium release exhibited 370 fold increases relative to the rate of uranium release in the absence of bicarbonate. However, the effect of increasing concentrations of bicarbonate solutions on the release of uranium was significantly less under higher pH conditions. It is postulated that at high pH values, surface sites are saturated with carbonate, thus the addition of more bicarbonate would have less effect on uranium release. Results indicate the activation energies were unaffected by temperature and bicarbonate concentration variations, but were strongly dependent on pH conditions. As pH increased from 6 to 11, activation energy values were observed to decrease from 29.94 kJ mol-1 to 13.07 kJ mol-1. The calculated activation energies suggest a surface controlled dissolution mechanism.« less

Compositions and methods for treating nuclear fuel

DOEpatents

Soderquist, Chuck Z; Johnsen, Amanda M; McNamara, Bruce K; Hanson, Brady D; Smith, Steven C; Peper, Shane M

2013-08-13

Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Compositions and methods for treating nuclear fuel

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

Soderquist, Chuck Z; Johnsen, Amanda M; McNamara, Bruce K

Compositions are provided that include nuclear fuel. Methods for treating nuclear fuel are provided which can include exposing the fuel to a carbonate-peroxide solution. Methods can also include exposing the fuel to an ammonium solution. Methods for acquiring molybdenum from a uranium comprising material are provided.

Simultaneous reduction of arsenic(V) and uranium(VI) by mackinawite: role of uranyl arsenate precipitate formation.

PubMed

Troyer, Lyndsay D; Tang, Yuanzhi; Borch, Thomas

2014-12-16

Uranium (U) and arsenic (As) often occur together naturally and, as a result, can be co-contaminants at sites of uranium mining and processing, yet few studies have examined the simultaneous redox dynamics of U and As. This study examines the influence of arsenate (As(V)) on the reduction of uranyl (U(VI)) by the redox-active mineral mackinawite (FeS). As(V) was added to systems containing 47 or 470 μM U(VI) at concentrations ranging from 0 to 640 μM. In the absence of As(V), U was completely removed from solution and fully reduced to nano-uraninite (nano-UO2). While the addition of As(V) did not reduce U uptake, at As(V) concentrations above 320 μM, the reduction of U(VI) was limited due to the formation of a trögerite-like uranyl arsenate precipitate. The presence of U also significantly inhibited As(V) reduction. While less U(VI) reduction to nano-UO2 may take place in systems with high As(V) concentrations, formation of trögerite-like mineral phases may be an acceptable reclamation end point due to their high stability under oxic conditions.

MICROSCALE METABOLIC, REDOX AND ABIOTIC REACTIONS IN HANFORD 300 AREA SUBSURFACE SEDIMENTS

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

Beyenal, Haluk; McLEan, Jeff; Majors, Paul

2013-11-14

The Hanford 300 Area is a unique site due to periodic hydrologic influence of river water resulting in changes in groundwater elevation and flow direction. This area is also highly subject to uranium remobilization, the source of which is currently believed to be the region at the base of the vadose zone that is subject to period saturation due to the changes in the water levels in the Columbia River. We found that microbial processes and redox and abiotic reactions which operate at the microscale were critical to understanding factors controlling the macroscopic fate and transport of contaminants in themore » subsurface. The combined laboratory and field research showed how microscale conditions control uranium mobility and how biotic, abiotic and redox reactions relate to each other. Our findings extended the current knowledge to examine U(VI) reduction and immobilization using natural 300 Area communities as well as selected model organisms on redox-sensitive and redox-insensitive minerals. Using innovative techniques developed specifically to probe biogeochemical processes at the microscale, our research expanded our current understanding of the roles played by mineral surfaces, bacterial competition, and local biotic, abiotic and redox reaction rates on the reduction and immobilization of uranium.« less

Concerted Uranium Research in Europe (CURE): toward a collaborative project integrating dosimetry, epidemiology and radiobiology to study the effects of occupational uranium exposure.

PubMed

Laurent, Olivier; Gomolka, Maria; Haylock, Richard; Blanchardon, Eric; Giussani, Augusto; Atkinson, Will; Baatout, Sarah; Bingham, Derek; Cardis, Elisabeth; Hall, Janet; Tomasek, Ladislav; Ancelet, Sophie; Badie, Christophe; Bethel, Gary; Bertho, Jean-Marc; Bouet, Ségolène; Bull, Richard; Challeton-de Vathaire, Cécile; Cockerill, Rupert; Davesne, Estelle; Ebrahimian, Teni; Engels, Hilde; Gillies, Michael; Grellier, James; Grison, Stephane; Gueguen, Yann; Hornhardt, Sabine; Ibanez, Chrystelle; Kabacik, Sylwia; Kotik, Lukas; Kreuzer, Michaela; Lebacq, Anne Laure; Marsh, James; Nosske, Dietmar; O'Hagan, Jackie; Pernot, Eileen; Puncher, Matthew; Rage, Estelle; Riddell, Tony; Roy, Laurence; Samson, Eric; Souidi, Maamar; Turner, Michelle C; Zhivin, Sergey; Laurier, Dominique

2016-06-01

The potential health impacts of chronic exposures to uranium, as they occur in occupational settings, are not well characterized. Most epidemiological studies have been limited by small sample sizes, and a lack of harmonization of methods used to quantify radiation doses resulting from uranium exposure. Experimental studies have shown that uranium has biological effects, but their implications for human health are not clear. New studies that would combine the strengths of large, well-designed epidemiological datasets with those of state-of-the-art biological methods would help improve the characterization of the biological and health effects of occupational uranium exposure. The aim of the European Commission concerted action CURE (Concerted Uranium Research in Europe) was to develop protocols for such a future collaborative research project, in which dosimetry, epidemiology and biology would be integrated to better characterize the effects of occupational uranium exposure. These protocols were developed from existing European cohorts of workers exposed to uranium together with expertise in epidemiology, biology and dosimetry of CURE partner institutions. The preparatory work of CURE should allow a large scale collaborative project to be launched, in order to better characterize the effects of uranium exposure and more generally of alpha particles and low doses of ionizing radiation.

Uranium quantification in semen by inductively coupled plasma mass spectrometry

USGS Publications Warehouse

Todorov, Todor I.; Ejnik, John W.; Guandalini, Gustavo S.; Xu, Hanna; Hoover, Dennis; Anderson, Larry W.; Squibb, Katherine; McDiarmid, Melissa A.; Centeno, Jose A.

2013-01-01

In this study we report uranium analysis for human semen samples. Uranium quantification was performed by inductively coupled plasma mass spectrometry. No additives, such as chymotrypsin or bovine serum albumin, were used for semen liquefaction, as they showed significant uranium content. For method validation we spiked 2 g aliquots of pooled control semen at three different levels of uranium: low at 5 pg/g, medium at 50 pg/g, and high at 1000 pg/g. The detection limit was determined to be 0.8 pg/g uranium in human semen. The data reproduced within 1.4–7% RSD and spike recoveries were 97–100%. The uranium level of the unspiked, pooled control semen was 2.9 pg/g of semen (n = 10). In addition six semen samples from a cohort of Veterans exposed to depleted uranium (DU) in the 1991 Gulf War were analyzed with no knowledge of their exposure history. Uranium levels in the Veterans’ semen samples ranged from undetectable (<0.8 pg/g) to 3350 pg/g. This wide concentration range for uranium in semen is consistent with known differences in current DU body burdens in these individuals, some of whom have retained embedded DU fragments.

Caulobacter crescentus as a Whole-Cell Uranium Biosensor▿ †

PubMed Central

Hillson, Nathan J.; Hu, Ping; Andersen, Gary L.; Shapiro, Lucy

2007-01-01

We engineered a strain of the bacterium Caulobacter crescentus to fluoresce in the presence of micromolar levels of uranium at ambient temperatures when it is exposed to a hand-held UV lamp. Previous microarray experiments revealed that several Caulobacter genes are significantly upregulated in response to uranium but not in response to other heavy metals. We designated one of these genes urcA (for uranium response in caulobacter). We constructed a reporter that utilizes the urcA promoter to produce a UV-excitable green fluorescent protein in the presence of the uranyl cation, a soluble form of uranium. This reporter is specific for uranium and has little cross specificity for nitrate (<400 μM), lead (<150 μM), cadmium (<48 μM), or chromium (<41.6 μM). The uranium reporter construct was effective for discriminating contaminated groundwater samples (4.2 μM uranium) from uncontaminated groundwater samples (<0.1 μM uranium) collected at the Oak Ridge Field Research Center. In contrast to other uranium detection methodologies, the Caulobacter reporter strain can provide on-demand usability in the field; it requires minimal sample processing and no equipment other than a hand-held UV lamp, and it may be sprayed directly on soil, groundwater, or industrial surfaces. PMID:17905881

Depleted uranium analysis in blood by inductively coupled plasma mass spectrometry

USGS Publications Warehouse

Todorov, T.I.; Xu, H.; Ejnik, J.W.; Mullick, F.G.; Squibb, K.; McDiarmid, M.A.; Centeno, J.A.

2009-01-01

In this study we report depleted uranium (DU) analysis in whole blood samples. Internal exposure to DU causes increased uranium levels as well as change in the uranium isotopic composition in blood specimen. For identification of DU exposure we used the 235U/238U ratio in blood samples, which ranges from 0.00725 for natural uranium to 0.002 for depleted uranium. Uranium quantification and isotopic composition analysis were performed by inductively coupled plasma mass spectrometry. For method validation we used eight spiked blood samples with known uranium concentrations and isotopic composition. The detection limit for quantification was determined to be 4 ng L-1 uranium in whole blood. The data reproduced within 1-5% RSD and an accuracy of 1-4%. In order to achieve a 235U/238U ratio range of 0.00698-0.00752% with 99.7% confidence limit a minimum whole blood uranium concentration of 60 ng L??1 was required. An additional 10 samples from a cohort of veterans exposed to DU in Gulf War I were analyzed with no knowledge of their medical history. The measured 235U/ 238U ratios in the blood samples were used to identify the presence or absence of DU exposure within this patient group. ?? 2009 The Royal Society of Chemistry.

Radon and Cancer

MedlinePlus

... in the Danish study: another source of dose. Health Physics 2009; 97(4):343–347. [PubMed Abstract] Krewski ... radiation and leukemia risk among German uranium miners. Health Physics 2010; 99(3):314–321. [PubMed Abstract] National ...

Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

USGS Publications Warehouse

Sims, P.K.; Osterwald, F.W.; Tooker, E.W.

1954-01-01

The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these that deposited pitchblende.

Microbial communities associated with uranium in-situ recovery mining process are related to acid mine drainage assemblages.

PubMed

Coral, Thomas; Descostes, Michaël; De Boissezon, Hélène; Bernier-Latmani, Rizlan; de Alencastro, Luiz Felippe; Rossi, Pierre

2018-07-01

A large fraction (47%) of the world's uranium is mined by a technique called "In Situ Recovery" (ISR). This mining technique involves the injection of a leaching fluid (acidic or alkaline) into a uranium-bearing aquifer and the pumping of the resulting solution through cation exchange columns for the recovery of dissolved uranium. The present study reports the in-depth alterations brought to autochthonous microbial communities during acidic ISR activities. Water samples were collected from a uranium roll-front deposit that is part of an ISR mine in operation (Tortkuduk, Kazakhstan). Water samples were obtained at a depth of ca 500 m below ground level from several zones of the Uyuk aquifer following the natural redox zonation inherited from the roll front deposit, including the native mineralized orebody and both upstream and downstream adjacent locations. Samples were collected equally from both the entrance and the exit of the uranium concentration plant. Next-generation sequencing data showed that the redox gradient shaped the community structures, within the anaerobic, reduced, and oligotrophic habitats of the native aquifer zones. Acid injection induced drastic changes in the structures of these communities, with a large decrease in both cell numbers and diversity. Communities present in the acidified (pH values < 2) mining areas exhibited similarities to those present in acid mine drainage, with the dominance of Sulfobacillus sp., Leptospirillum sp. and Acidithiobacillus sp., as well as the archaean Ferroplasma sp. Communities located up- and downstream of the mineralized zone under ISR and affected by acidic fluids were blended with additional facultative anaerobic and acidophilic microorganisms. These mixed biomes may be suitable communities for the natural attenuation of ISR mining-affected subsurface through the reduction of metals and sulfate. Assessing the effect of acidification on the microbial community is critical to evaluating the potential for natural attenuation or active bioremediation strategies. Copyright © 2018 Elsevier B.V. All rights reserved.

Organic matter diagenesis as the key to a unifying theory for the genesis of tabular uranium-vanadium deposits in the Morrison Formation, Colorado Plateau

USGS Publications Warehouse

Hansley, P.L.; Spirakis, C.S.

1992-01-01

Interstitial, epigenetic amorphous organic matter is intimately associated with uranium in the Grants uranium region and is considered essential to genetic models for these deposits. In contrast, uranium minerals are intimately associated with authigenic vanadium chlorite and vanadium oxides in amorphous organic matter-poor ores of the Slick Rock and Henry Mountains mining districts and therefore, in some genetic models amorphous organic matter is not considered crucial to the formation of these deposits. Differences in organic matter content can be explained by recognizing that amorphous organic matter-poor deposits have been subjected to more advanced stages of diagenesis than amorphous organic matter-rich deposits. Evidence that amorphous organic matter was involved in the genesis of organic matter-poor, as well as organic matter-rich, deposits is described. -from Authors

Aerial radiometric and magnetic reconnaissance survey of Baltimore, Washington, and Richmond Quadrangles: Washington Quadrangle

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

Not Available

1978-09-01

The results of a high-sensitivity aerial gamma-ray spectrometer and magnetometer survey of the Washington Quadrangle, Maryland and Virginia, are presentd. Instrumentation and methods are described in Volume 1 of this final report. Statistical and geological analysis of the radiometric data revealed six uranium anomalies worthy of field checking as possible prospects. Four (1, 2, 7, and 8) are located over sediments that may have long-range future potential for low-grade sedimentary uranium deposits. In particular, anomalies 1 and 8 are related to a unit (Triassic New Oxford Formation) known to contain uranium occurrences in Pennsylvania. One anomaly (3) may be associatedmore » with vein-type mineralization in augen gneiss, and one (12) may be caused by vein-type or hydrothermal uranium associated with a north-south striking fault at the boundary between the Appalachian Highlands and the Coastal Plain physiographic provinces.« less

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 Akaike information criterion, it was equal to 1.44 (0.66; 3.14). To our knowledge, this is the first study to use a uranium miner cohort to consider the major standard CSD risk factors in assessing the relationships between ionizing radiation exposure and the risk of death from these diseases. These results suggest that the significant relationship between CeVD risk and radon exposure observed in the total French cohort is probably not affected by the CSD risk factors. Extending the collection of information about CSD risk factors to a larger subsample would be useful to confirm this result.

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.

Remote sensing and uranium exploration at Lisbon Valley, Utah

NASA Technical Reports Server (NTRS)

Conel, J. E.; Niesen, P. L.

1981-01-01

As part of the joint NASA-Geosat uranium test case program, aircraft-acquired multispectral scanner data are used to investigate the distribution of bleaching in Windgate sandstone exposed in Lisbon Valley anticline, Utah. It is noted that all of the large ore bodies contained in lower Chinle Triassic age or Cutler Permian age strata in this area lie beneath or closely adjacent to such bleached outcrops. The geographic coincidences reported here are seen as inviting renewed interest in speculation of a causal relation between occurrences of Mississippian-Pennsylvanian oil and gas in this area and of Triassic uranium accumulation and rock bleaching.

PROCESS FOR PRODUCTION OF URANIUM

DOEpatents

Crawford, J.W.C.

1959-09-29

A process is described for the production of uranium by the autothermic reduction of an anhydrous uranium halide with an alkaline earth metal, preferably magnesium One feature is the initial reduction step which is brought about by locally bringing to reaction temperature a portion of a mixture of the reactants in an open reaction vessel having in contact with the mixture a lining of substantial thickness composed of calcium fluoride. The lining is prepared by coating the interior surface with a plastic mixture of calcium fluoride and water and subsequently heating the coating in situ until at last the exposed surface is substantially anhydrous.

Precipitation and Dissolution of Uranyl Phosphates in a Microfluidic Pore Structure

NASA Astrophysics Data System (ADS)

Werth, C. J.; Fanizza, M.; Strathmann, T.; Finneran, K.; Oostrom, M.; Zhang, C.; Wietsma, T. W.; Hess, N. J.

2011-12-01

The abiotic precipitation of uranium (U(VI)) was evaluated in a microfluidic pore structure (i.e. micromodel) to assess the efficacy of using a phosphate amendment to immobilize uranium in groundwater and mitigate the risk of this contaminant to potential down-gradient receptor sites. U(VI) was mixed transverse to the direction of flow with hydrogen phosphate (HPO42-), in the presence or absence of calcium (Ca2+) or sulfate (SO42-), in order to identify precipitation rates, the morphology and types of minerals formed, and the stability of these minerals to dissolution with and without bicarbonate (HCO3-) present. Raman backscattering spectroscopy and micro X-ray diffraction (μ-XRD) results both showed that the only mineral precipitated was chernikovite (also known as hydrogen uranyl phosphate; UO2HPO4), even though the formation of other minerals were thermodynamically favored depending on the experimental conditions. Precipitation and dissolution rates varied with influent conditions. Relative to when only U(VI) and HPO42- were present, precipitation rates were 2.3 times slower when SO42- was present, and 1.4 times faster when Ca2+ was present. These rates were inversely related to the size of crystals formed during precipitation. Dissolution rates for chernikovite increased with increasing HCO3- concentrations, consistent with formation of uranyl carbonate complexes in aqueous solution, and they were the fastest for chernikovite formed in the presence of SO42-, and slowest for the chernikovite formed in the presence of Ca2+. These rates are related to the ratios of mineral-water interfacial area to mineral volume. Fluorescent tracer studies and laser confocal microscopy images showed that densely aggregated precipitates blocked pores and reduced permeability. The results suggest that changes in the solute conditions evaluated affect precipitation rates, crystal morphology, and crystal stability, but not mineral type.

Uranium Associations with Kidney Outcomes Vary by Urine Concentration Adjustment Method

PubMed Central

Shelley, Rebecca; Kim, Nam-Soo; Parsons, Patrick J.; Lee, Byung-Kook; Agnew, Jacqueline; Jaar, Bernard G.; Steuerwald, Amy J.; Matanoski, Genevieve; Fadrowski, Jeffrey; Schwartz, Brian S.; Todd, Andrew C.; Simon, David; Weaver, Virginia M.

2017-01-01

Uranium is a ubiquitous metal that is nephrotoxic at high doses. Few epidemiologic studies have examined the kidney filtration impact of chronic environmental exposure. In 684 lead workers environmentally exposed to uranium, multiple linear regression was used to examine associations of uranium measured in a four-hour urine collection with measured creatinine clearance, serum creatinine- and cystatin-C-based estimated glomerular filtration rates, and N-acetyl-β-D-glucosaminidase (NAG). Three methods were utilized, in separate models, to adjust uranium levels for urine concentration - μg uranium/g creatinine; μg uranium/L and urine creatinine as separate covariates; and μg uranium/4 hr. Median urine uranium levels were 0.07 μg/g creatinine and 0.02 μg/4 hr and were highly correlated (rs =0.95). After adjustment, higher ln-urine uranium was associated with lower measured creatinine clearance and higher NAG in models that used urine creatinine to adjust for urine concentration but not in models that used total uranium excreted (μg/4 hr). These results suggest that, in some instances, associations between urine toxicants and kidney outcomes may be statistical, due to the use of urine creatinine in both exposure and outcome metrics, rather than nephrotoxic. These findings support consideration of non-creatinine-based methods of adjustment for urine concentration in nephrotoxicant research. PMID:23591699

Retention and chemical speciation of uranium in an oxidized wetland sediment from the Savannah River Site.

PubMed

Li, Dien; Seaman, John C; Chang, Hyun-Shik; Jaffe, Peter R; Koster van Groos, Paul; Jiang, De-Tong; Chen, Ning; Lin, Jinru; Arthur, Zachary; Pan, Yuanming; Scheckel, Kirk G; Newville, Matthew; Lanzirotti, Antonio; Kaplan, Daniel I

2014-05-01

Uranium speciation and retention mechanisms onto Savannah River Site (SRS) wetland sediments was studied using batch (ad)sorption experiments, sequential extraction, U L3-edge X-ray absorption near-edge structure (XANES) spectroscopy, fluorescence mapping and μ-XANES. Under oxidized conditions, U was highly retained by the SRS wetland sediments. In contrast to other similar but much lower natural organic matter (NOM) sediments, significant sorption of U onto the SRS sediments was observed at pH < 4 and pH > 8. Sequential extraction indicated that the U species were primarily associated with the acid soluble fraction (weak acetic acid extractable) and organic fraction (Na-pyrophosphate extractable). Uranium L3-edge XANES spectra of the U-bound sediments were nearly identical to that of uranyl acetate. Based on fluorescence mapping, U and Fe distributions in the sediment were poorly correlated, U was distributed throughout the sample and did not appear as isolated U mineral phases. The primary oxidation state of U in these oxidized sediments was U(VI), and there was little evidence that the high sorptive capacity of the sediments could be ascribed to abiotic or biotic reduction to the less soluble U(IV) species or to secondary mineral formation. Collectively, this study suggests that U may be strongly bound to wetland sediments, not only under reducing conditions by reductive precipitation, but also under oxidizing conditions through NOM-uranium bonding. Published by Elsevier Ltd.

Transgenerational Adaptation to Pollution Changes Energy Allocation in Populations of Nematodes.

PubMed

Goussen, Benoit; Péry, Alexandre R R; Bonzom, Jean-Marc; Beaudouin, Rémy

2015-10-20

Assessing the evolutionary responses of long-term exposed populations requires multigeneration ecotoxicity tests. However, the analysis of the data from these tests is not straightforward. Mechanistic models allow the in-depth analysis of the variation of physiological traits over many generations, by quantifying the trend of the physiological and toxicological parameters of the model. In the present study, a bioenergetic mechanistic model has been used to assess the evolution of two populations of the nematode Caenorhabditis elegans in control conditions or exposed to uranium. This evolutionary pressure resulted in a brood size reduction of 60%. We showed an adaptation of individuals of both populations to experimental conditions (increase of maximal length, decrease of growth rate, decrease of brood size, and decrease of the elimination rate). In addition, differential evolution was also highlighted between the two populations once the maternal effects had been diminished after several generations. Thus, individuals that were greater in maximal length, but with apparently a greater sensitivity to uranium were selected in the uranium population. In this study, we showed that this bioenergetics mechanistic modeling approach provided a precise, certain, and powerful analysis of the life strategy of C. elegans populations exposed to heavy metals resulting in an evolutionary pressure across successive generations.

Uranium Biominerals Precipitated by an Environmental Isolate of Serratia under Anaerobic Conditions.

PubMed

Newsome, Laura; Morris, Katherine; Lloyd, Jonathan R

2015-01-01

Stimulating the microbially-mediated precipitation of uranium biominerals may be used to treat groundwater contamination at nuclear sites. The majority of studies to date have focussed on the reductive precipitation of uranium as U(IV) by U(VI)- and Fe(III)-reducing bacteria such as Geobacter and Shewanella species, although other mechanisms of uranium removal from solution can occur, including the precipitation of uranyl phosphates via bacterial phosphatase activity. Here we present the results of uranium biomineralisation experiments using an isolate of Serratia obtained from a sediment sample representative of the Sellafield nuclear site, UK. When supplied with glycerol phosphate, this Serratia strain was able to precipitate 1 mM of soluble U(VI) as uranyl phosphate minerals from the autunite group, under anaerobic and fermentative conditions. Under phosphate-limited anaerobic conditions and with glycerol as the electron donor, non-growing Serratia cells could precipitate 0.5 mM of uranium supplied as soluble U(VI), via reduction to nano-crystalline U(IV) uraninite. Some evidence for the reduction of solid phase uranyl(VI) phosphate was also observed. This study highlights the potential for Serratia and related species to play a role in the bioremediation of uranium contamination, via a range of different metabolic pathways, dependent on culturing or in situ conditions.

Uranium Biominerals Precipitated by an Environmental Isolate of Serratia under Anaerobic Conditions

PubMed Central

Newsome, Laura; Morris, Katherine; Lloyd, Jonathan. R.

2015-01-01

Stimulating the microbially-mediated precipitation of uranium biominerals may be used to treat groundwater contamination at nuclear sites. The majority of studies to date have focussed on the reductive precipitation of uranium as U(IV) by U(VI)- and Fe(III)-reducing bacteria such as Geobacter and Shewanella species, although other mechanisms of uranium removal from solution can occur, including the precipitation of uranyl phosphates via bacterial phosphatase activity. Here we present the results of uranium biomineralisation experiments using an isolate of Serratia obtained from a sediment sample representative of the Sellafield nuclear site, UK. When supplied with glycerol phosphate, this Serratia strain was able to precipitate 1 mM of soluble U(VI) as uranyl phosphate minerals from the autunite group, under anaerobic and fermentative conditions. Under phosphate-limited anaerobic conditions and with glycerol as the electron donor, non-growing Serratia cells could precipitate 0.5 mM of uranium supplied as soluble U(VI), via reduction to nano-crystalline U(IV) uraninite. Some evidence for the reduction of solid phase uranyl(VI) phosphate was also observed. This study highlights the potential for Serratia and related species to play a role in the bioremediation of uranium contamination, via a range of different metabolic pathways, dependent on culturing or in situ conditions. PMID:26132209

Depleted uranium instead of lead in munitions: the lesser evil.

PubMed

Jargin, Sergei V

2014-03-01

Uranium has many similarities to lead in its exposure mechanisms, metabolism and target organs. However, lead is more toxic, which is reflected in the threshold limit values. The main potential hazard associated with depleted uranium is inhalation of the aerosols created when a projectile hits an armoured target. A person can be exposed to lead in similar ways. Accidental dangerous exposures can result from contact with both substances. Encountering uranium fragments is of minor significance because of the low penetration depth of alpha particles emitted by uranium: they are unable to penetrate even the superficial keratin layer of human skin. An additional cancer risk attributable to the uranium exposure might be significant only in case of prolonged contact of the contaminant with susceptible tissues. Lead intoxication can be observed in the wounded, in workers manufacturing munitions etc; moreover, lead has been documented to have a negative impact on the intellectual function of children at very low blood concentrations. It is concluded on the basis of the literature overview that replacement of lead by depleted uranium in munitions would be environmentally beneficial or largely insignificant because both lead and uranium are present in the environment.

The Permo-Triassic uranium deposits of Gondwanaland

NASA Astrophysics Data System (ADS)

le Roux, J. P.; Toens, P. D.

The world's uranium provinces are time bound and occur in five distinct periods ranging from the Proterozoic to the Recent. One of these periods embraces the time of Gondwana sedimentation and probably is related to the proliferation of land plants from the Devonian on-ward. Decaying vegetal matter produced reducing conditions that enhanced uranium precipitation. The association of uranium with molassic basins adjacent to uplifted granitic and volcanic arcs suggests that lithospheric plate subduction, leading to anatexis of basement rocks and andesitic volcanism, created favorable conditions for uranium mineralization. Uranium occurrences of Gondwana age are of four main types: sandstone-hosted, coal-hosted, pelite-hosted, and vein-type deposits. Sandstone-hosted deposits commonly occur in fluviodeltaic sediments and are related to the presence of organic matter. These deposits commonly are enriched in molybdenum and other base metal sulfides and have been found in South Africa, Zimbabwe, Zambia, Angola, Niger, Madagascar, India, Australia, Argentina, and Brazil. Coalhosted deposits contain large reserves of uranium but are of low grade. In Africa they are mostly within the Permian Ecca Group and its lateral equivalents, as in the Springbok Flats, Limpopo, Botswana, and Tanzania basins. Uraniferous black shales are present in the Gabon and Amazon basins but grades are low. Vein-type uranium is found in Argentina, where it occurs in clustered veins crosscutting sedimentary rocks and quartz porphyries.

Uranium as a possible criterion for the hydro-chemical alteration of betafite

NASA Astrophysics Data System (ADS)

Hosseinpour Khanmiri, Mohammad; Yanson, Svetlana Yu.; Fomin, Edward V.; Titov, Anatoly V.; Grebeniuk, Andrey V.; Polekhovsky, Yury S.; Bogdanov, Roman V.

2018-01-01

Hydro-chemical processes significantly alter the original composition of metamict minerals. In the work presented here, an attempt was made to reconstruct the chemical composition of betafite in the earlier stages of its geological history. The time scale is determined by the leaching rate of the isotope 238U, a process that takes its course in line with first-order kinetics, or something close to it. The leaching rate constant of this uranium isotope was assessed. Based on available data in the literature, the hydro-chemical behavior of various atoms in group A of betafite was analyzed. The chemical composition of the mineral was calculated taking into account the total charge of the cations that the betafite had at the time it was formed, or possibly the last time it was completely reformed as a result of diverse endogenic processes.

Composition, stability, and measurement of reduced uranium phases for groundwater bioremediation at Old Rifle, CO

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

Campbell, K. M.; Davis, J. A.; Bargar, J.

2011-10-15

Reductive biostimulation is currently being explored as a possible remediation strategy for uranium (U) contaminated groundwater, and is currently being investigated at a field site in Rifle, CO, USA. The long-term stability of the resulting U(IV) phases is a key component of the overall performance and depends upon a variety of factors, including rate and mechanism of reduction, mineral associations in the subsurface, and propensity for oxidation. To address these factors, several approaches were used to evaluate the redox sensitivity of U: measurement of the rate of oxidative dissolution of biogenic uraninite (UO{sub 2(s)}) deployed in groundwater at Rifle, characterizationmore » of a zone of natural bioreduction exhibiting relevant reduced mineral phases, and laboratory studies of the oxidative capacity of Fe(III) and reductive capacity of Fe(II) with regard to U(IV) and U(VI), respectively.« less

WHETSTONE ROADLESS AREA, ARIZONA.

USGS Publications Warehouse

Wrucke, Chester T.; McColly, Robert A.

1984-01-01

A mineral survey conducted has shown that areas in and adjacent to the Whetstone Roadless Area, Arizona have a substantiated resource potential for copper, lead, gold, silver, and quartz, and a probable mineral-resource potential for copper silver, lead, gold, molybdenum, tungsten, uranium, and gypsum. Copper and silver occur in a small vein deposit in the southwestern part of the roadless area. Copper, lead, silver, gold, and molybdenum are known in veins associated with a porphyry copper deposit in a reentrant near the southern border of the roadless area. Vein deposits of tungsten and uranium are possible in the northeast part of the roadless area near areas of known production of these commodities. Demonstrated resources of quartz for smelter flux extend into the roadless area from the Ricketts mine. Areas of probable potential for gypsum resources also occur within the roadless area. No potential for fossil fuel resources was identified in the study.

Uranium as a possible criterion for the hydro-chemical alteration of betafite

NASA Astrophysics Data System (ADS)

Hosseinpour Khanmiri, Mohammad; Yanson, Svetlana Yu.; Fomin, Edward V.; Titov, Anatoly V.; Grebeniuk, Andrey V.; Polekhovsky, Yury S.; Bogdanov, Roman V.

2018-06-01

Hydro-chemical processes significantly alter the original composition of metamict minerals. In the work presented here, an attempt was made to reconstruct the chemical composition of betafite in the earlier stages of its geological history. The time scale is determined by the leaching rate of the isotope 238U, a process that takes its course in line with first-order kinetics, or something close to it. The leaching rate constant of this uranium isotope was assessed. Based on available data in the literature, the hydro-chemical behavior of various atoms in group A of betafite was analyzed. The chemical composition of the mineral was calculated taking into account the total charge of the cations that the betafite had at the time it was formed, or possibly the last time it was completely reformed as a result of diverse endogenic processes.

Effect of exposure of miners to aluminium powder.

PubMed

Rifat, S L; Eastwood, M R; McLachlan, D R; Corey, P N

1990-11-10

'McIntyre Powder' (finely ground aluminium and aluminium oxide) was used as a prophylactic agent against silicotic lung disease between 1944 and 1979 in mines in northern Ontario. To find out whether the practice produced neurotoxic effects a morbidity prevalence study was conducted between 1988 and 1989. There were no significant differences between exposed and non-exposed miners in reported diagnoses of neurological disorder; however, exposed miners performed less well than did unexposed workers on cognitive state examinations; also, the proportion of men with scores in the impaired range was greater in the exposed than non-exposed group. Likelihood of scores in the impaired range increased with duration of exposure. The findings are consistent with putative neurotoxicity of chronic aluminium exposure.

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

Cunningham, C.G.; Steven, T.A.

In studying the economic mineral potential of the Tushar Mountains and adjacent areas in west-central Utah, members of the US Geological Survey have delineated several geologic environments that seem favorable for the occurrence of uranium deposits. This report is concerned primarily with three areas: (1) the ring fracture zone of the Mount Belknap caldera, (2) the Beaver Valley, and (3) the Sevier River Valley near Marysvale. The data and interpretations presented are tentative and will be revised as work in the area continues. Other environments containing uranium exist, but are not discussed here. This report presents preliminary geologic data andmore » interpretations to assist in uranium resource evaluation by the US Department of Energy, and to aid in exploration programs by private industry.« less

Oxidation of naturally reduced uranium in aquifer sediments by dissolved oxygen and its potential significance to uranium plume persistence

NASA Astrophysics Data System (ADS)

Davis, J. A.; Smith, R. L.; Bohlke, J. K.; Jemison, N.; Xiang, H.; Repert, D. A.; Yuan, X.; Williams, K. H.

2015-12-01

The occurrence of naturally reduced zones is common in alluvial aquifers in the western U.S.A. due to the burial of woody debris in flood plains. Such reduced zones are usually heterogeneously dispersed in these aquifers and characterized by high concentrations of organic carbon, reduced mineral phases, and reduced forms of metals, including uranium(IV). The persistence of high concentrations of dissolved uranium(VI) at uranium-contaminated aquifers on the Colorado Plateau has been attributed to slow oxidation of insoluble uranium(IV) mineral phases found in association with these reducing zones, although there is little understanding of the relative importance of various potential oxidants. Four field experiments were conducted within an alluvial aquifer adjacent to the Colorado River near Rifle, CO, wherein groundwater associated with the naturally reduced zones was pumped into a gas-impermeable tank, mixed with a conservative tracer (Br-), bubbled with a gas phase composed of 97% O2 and 3% CO2, and then returned to the subsurface in the same well from which it was withdrawn. Within minutes of re-injection of the oxygenated groundwater, dissolved uranium(VI) concentrations increased from less than 1 μM to greater than 2.5 μM, demonstrating that oxygen can be an important oxidant for uranium in such field systems if supplied to the naturally reduced zones. Dissolved Fe(II) concentrations decreased to the detection limit, but increases in sulfate could not be detected due to high background concentrations. Changes in nitrogen species concentrations were variable. The results contrast with other laboratory and field results in which oxygen was introduced to systems containing high concentrations of mackinawite (FeS), rather than the more crystalline iron sulfides found in aged, naturally reduced zones. The flux of oxygen to the naturally reduced zones in the alluvial aquifers occurs mainly through interactions between groundwater and gas phases at the water table. Seasonal variations of the water table at the Rifle, CO site may play an important role in introducing oxygen into the system. Although oxygen was introduced directly to the naturally reduced zones in these experiments, delivery of oxidants to the system may also be controlled by other oxidative pathways in which oxygen plays an indirect role.

Calixarene cleansing formulation for uranium skin contamination.

PubMed

Phan, Guillaume; Semili, Naïma; Bouvier-Capely, Céline; Landon, Géraldine; Mekhloufi, Ghozlene; Huang, Nicolas; Rebière, François; Agarande, Michelle; Fattal, Elias

2013-10-01

An oil-in-water cleansing emulsion containing calixarene molecule, an actinide specific chelating agent, was formulated in order to improve the decontamination of uranium from the skin. Commonly commercialized cosmetic ingredients such as surfactants, mineral oil, or viscosifying agents were used in preparing the calixarene emulsion. The formulation was characterized in terms of size and apparent viscosity measurements and then was tested for its ability to limit uranyl ion permeation through excoriated pig-ear skin explants in 24-h penetration studies. Calixarene emulsion effectiveness was compared with two other reference treatments consisting of DTPA and EHBP solutions. Application of calixarene emulsion induced the highest decontamination effect with an 87% decrease in uranium diffusion flux. By contrast, EHBP and DTPA solutions only allowed a 50% and 55% reduction of uranium permeation, respectively, and had the same effect as a simple dilution of the contamination by pure water. Uranium diffusion decrease was attributed to uranyl ion-specific chelation by calixarene within the formulation, since no significant effect was obtained after application of the same emulsion without calixarene. Thus, calixarene cleansing emulsion could be considered as a promising treatment in case of accidental contamination of the skin by highly diffusible uranium compounds.

US Transuranium and Uranium Registries case study on accidental exposure to uranium hexafluoride.

PubMed

Avtandilashvili, Maia; Puncher, Matthew; McComish, Stacey L; Tolmachev, Sergei Y

2015-03-01

The United States Transuranium and Uranium Registries' (USTUR) whole-body donor (Case 1031) was exposed to an acute inhalation of uranium hexafluoride (UF6) produced from an explosion at a uranium processing plant 65 years prior to his death. The USTUR measurements of tissue samples collected at the autopsy indicated long-term retention of inhaled slightly enriched uranium material (0.85% (235)U) in the deep lungs and thoracic lymph nodes. In the present study, the authors combined the tissue measurement results with historical bioassay data, and analysed them with International Commission on Radiological Protection (ICRP) respiratory tract models and the ICRP Publication 69 systemic model for uranium using maximum likelihood and Bayesian statistical methods. The purpose of the analysis was to estimate intakes and model parameter values that best describe the data, and evaluate their effect on dose assessment. The maximum likelihood analysis, which used the ICRP Publication 66 human respiratory tract model, resulted in a point estimate of 79 mg of uranium for the occupational intake composed of 86% soluble, type F material and 14% insoluble, type S material. For the Bayesian approach, the authors applied the Markov Chain Monte Carlo method, but this time used the revised human respiratory tract model, which is currently being used by ICRP to calculate new dose coefficients for workers. The Bayesian analysis estimated that the mean uranium intake was 160 mg, and calculated the case-specific lung dissolution parameters with their associated uncertainties. The parameters were consistent with the inhaled uranium material being predominantly soluble with a small but significant insoluble component. The 95% posterior range of the rapid dissolution fraction (the fraction of deposited material that is absorbed to blood rapidly) was 0.12 to 0.91 with a median of 0.37. The remaining fraction was absorbed slowly, with a 95% range of 0.000 22 d(-1) to 0.000 36 d(-1) and a median of 0.000 31 d(-1). The effective dose per unit intake calculated using the dissolution parameters derived from the maximum likelihood and the Bayesian analyses was higher than the current ICRP dose coefficient for type F uranium by a factor of 2 or 7, respectively; the higher value of the latter was due to use of the revised respiratory tract model. The dissolution parameter values obtained here may be more appropriate to use for radiation protection purposes when individuals are exposed to a UF6 mixture that contains an insoluble uranium component.

Preliminary report on uranium and thorium content of intrusive rocks in northeastern Washington and northern Idaho

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

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

1977-11-01

This study delineates favorable areas for uranium resources in northeastern Washington and northern Idaho by identifying granitic rocks with relatively large amounts of uranium and (or) thorium. Results are based on analysis of 344 rock samples. Uranium analyses obtained by gamma-ray spectrometric data correlate closely with fluorometric determinations. On the basis of cumulative frequency distribution curves, more than 8 ppM equivalent uranium and more than 20 ppM equivalent thorium are considered anomalous for granitic rocks in northeastern Washington and northern Idaho. Granitic rocks anomalously high in uranium and (or) thorium are concentrated in two northeast-trending belts. The most prominent, themore » Midnite-Hall Mountain belt, includes the Midnite and Sherwood uranium mines, and two lesser but productive areas farther north. This belt follows the contact between Precambrian and Paleozoic rocks, which is also the locus of the Kootenai arc fold belt. The second belt of anomalously radioactive granitic rocks is along the Republic graben, a prominent linear structure in an area with no recorded uranium production. Anomalously radioactive granitic rocks are generally massive quartz monzonite, alaskite, or pegmatite, which contain abundant quartz and potash feldspar. They are also characterized by pink potash feldspar, commonly as large phenocrysts, and by the presence of muscovite. Several uranium and thorium minerals have been identified in these rocks. The two belts of anomalously radioactive plutons are considered favorable for uranium resources. Deposits could occur in the intrusive rocks themselves or in favorable environments in adjacent rocks. 13 figs., 2 tables.« less

The distribution and mobility of uranium in glassy and zeolitized tuff, Keg Mountain area, Utah, U.S.A.

USGS Publications Warehouse

Zielinski, R.A.; Lindsey, D.A.; Rosholt, J.N.

1980-01-01

The distribution and mobility of uranium in a diagenetically altered, 8 Ma old tuff in the Keg Mountain area, Utah, are modelled in this study. The modelling represents an improvement over similar earlier studies in that it: (1) considers a large number of samples (76) collected with good geologic control and exhibiting a wide range of alteration; (2) includes radiometric data for Th, K and RaeU (radium equivalent uranium) as well as U; (3) considers mineralogic and trace-element data for the same samples; and (4) analyzes the mineral and chemical covariation by multivariate statistical methods. The variation of U in the tuff is controlled mainly by its primary abundance in glass and by the relative abundance of non-uraniferous detritus and uraniferous accessory minerals. Alteration of glass to zeolite, even though extensive, caused no large or systematic change in the bulk concentration of U in the tuff. Some redistribution of U during diagenesis is indicated by association of U with minor alteration products such as opal and hydrous Fe-Mn oxide minerals. Isotopic studies indicate that the zeolitized tuff has been open to migration of U decay products during the last 0.8 Ma. The tuff of Keg Mountain has not lost a statistically detectable fraction of its original U, even though it has a high (??? 9 ppm) trace U content and has been extensively altered to zeolite. Similar studies in a variety of geological environments are required in order to identify the particular combination of conditions most favorable for liberation and migration of U from tuffs. ?? 1980.

Radioactive mineral springs in Delta County, Colorado

USGS Publications Warehouse

Cadigan, Robert A.; Rosholt, John N.; Felmlee, J. Karen

1976-01-01

The system of springs in Delta County, Colo., contains geochemical clues to the nature and location of buried uranium-mineralized rock. The springs, which occur along the Gunnison River and a principal tributary between Delta and Paonia, are regarded as evidence of a still-functioning hydrothermal system. Associated with the springs are hydrogen sulfide and sulfur dioxide gas seeps, carbon dioxide gas-powered geysers, thick travertine deposits including radioactive travertine, and a flowing warm-water (41?C) radioactive well. Geochemical study of the springs is based on surface observations, on-site water-property measurements, and sampling of water, travertine, soft precipitates, and mud. The spring deposits are mostly carbonates, sulfates, sulfides, and chlorides that locally contain notable amounts of some elements, such as arsenic, barium, lithium, and radium. Samples from five localities have somewhat different trace element assemblages even though they are related to the same hydrothermal system. All the spring waters but one are dominated by sodium chloride or sodium bicarbonate. The exception is an acid sulfate water with a pH of 2.9, which contains high concentrations of aluminum and iron. Most of the detectable radioactivity is due to the presence of radium-226, a uranium daughter product, but at least one spring precipitate contains abundant radium-228, a thorium daughter product. The 5:1 ratio of radium-228 to radium-226 suggests the proximity of a vein-type deposit as a source for the radium. The proposed locus of a thorium-uranium mineral deposit is believed to lie in the vicinity of Paonia, Colo. Exact direction and depth are not determinable from data now available.

Thorium and Uranium in the Rock Raw Materials Used For the Production of Building Materials

NASA Astrophysics Data System (ADS)

Pękala, Agnieszka

2017-10-01

Thorium and uranium are constant components of all soils and most minerals thereby rock raw materials. They belong to the particularly dangerous elements because of their natural radioactivity. Evaluation of the content of the radioactive elements in the rock raw materials seems to be necessary in the early stage of the raw material evaluation. The rock formations operated from deposits often are accumulated in landfills and slag heaps where the concentration of the radioactive elements can be many times higher than under natural conditions. In addition, this phenomenon may refer to buildings where rock raw materials are often the main components of the construction materials. The global control system of construction products draws particular attention to the elimination of used construction products containing excessive quantities of the natural radioactive elements. In the presented study were determined the content of thorium and uranium in rock raw materials coming from the Bełachatów lignite deposit. The Bełchatów lignite deposit extracts mainly lignite and secondary numerous accompanying minerals with the raw material importance. In the course of the field works within the framework of the carried out work has been tested 92 samples of rocks of varied petrographic composition. There were carried out analyses of the content of the radioactive elements for 50 samples of limestone of the Jurassic age, 18 samples of kaolinite clays, and 24 samples of siliceous raw materials, represented by opoka-rocks, diatomites, gaizes and clastic rocks. The measurement of content of the natural radioactive elements thorium and uranium based on measuring the frequency counts of gamma quantum, recorded separately in measuring channels. At the same time performed measurements on volume patterns radioactive: thorium and uranium. The studies were carried out in Mazar spectrometer on the powdered material. Standardly performed ten measuring cycles, after which were calculated the concentration of radioactive elements in the sample. The highest concentration of thorium and uranium has been found in the clayey raw material. Their value was respectively from 8 to 12 mg/kg for thorium and from 2.3 to 3.5 mg/kg for uranium. In carbonate sediments the content of thorium was at the level from 0.5 to 2.1 mg/kg and uranium from 0.5-2.2 mg/kg. From a group of the siliceous raw materials the diatomite had a highest concentrations of radioactive elements where the content of thorium was from 1.5 to 1.8 mg/kg and uranium from 1.3 to 1.7 mg/kg.

Hydrogeochemical and stream sediment reconnaissance basic data report for Kingman NTMS Quadrangle, Arizona, California, and Nevada

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

Qualheim, B.J.

This report presents the results of the geochemical reconnaissance sampling in the Kingman 1 x 2 quadrangle of the National Topographical Map Series (NTMS). Wet and dry sediment samples were collected throughout the 18,770-km arid to semiarid area and water samples at available streams, springs, and wells. Neutron activation analysis of uranium and trace elements and other measurements made in the field and laboratory are presented in tabular hardcopy and microfiche format. The report includes five full-size overlays for use with the Kingman NTMS 1 : 250,000 quadrangle. Water sampling sites, water sample uranium concentrations, water-sample conductivity, sediment sampling sites,more » and sediment-sample total uranium and thorium concentrations are shown on the separate overlays. General geological and structural descriptions of the area are included and known uranium occurrences on this quadrangle are delineated. Results of the reconnaissance are briefly discussed and related to rock types in the final section of the report. The results are suggestive of uranium mineralization in only two areas: the Cerbat Mountains and near some of the western intrusives.« less

SOME GEOCHEMICAL METHODS OF URANIUM EXPLORATION

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

Illsley, C.T.; Bills, C.W.; Pollock, J.W.

Geochemical research and development projects were carried on to provide basic information which may be applied to exploration or general studies of uranium geology. The applications and limitations of various aspects of geochemistry to uranium geological problems are considerd. Modifications of existing analytical techniques were made and tested in the laboratory and in the field. These include rapid quantitative determination of unranium in water, soil and peat, and of trace amounts of sulfate and phosphate in water. Geochemical anomaly'' has been defined as a significant departure from the average abundance background of an element where the distribution has not beenmore » disturbed by mineralization. The detection and significance of geocthemical anomalies are directly related to the mobility of the element being sought in the zone of weathering. Mobility of uranium is governed by complex physical, chemical, and biological factors. For uranium anomalies in surface materils, the chemicaly factors affecting mobility are the most sigificant. The effects of pH, solubility, coprecipitution, adsorption complexion, or compound formation are discussed in relation to anomalies detected in water, soil, and stream sediments. (auth)« less

Experience of on-site disposal of production uranium-graphite nuclear reactor.

PubMed

Pavliuk, Alexander O; Kotlyarevskiy, Sergey G; Bespala, Evgeny V; Zakharova, Elena V; Ermolaev, Vyacheslav M; Volkova, Anna G

2018-04-01

The paper reported the experience gained in the course of decommissioning EI-2 Production Uranium-Graphite Nuclear Reactor. EI-2 was a production Uranium-Graphite Nuclear Reactor located on the Production and Demonstration Center for Uranium-Graphite Reactors JSC (PDC UGR JSC) site of Seversk City, Tomsk Region, Russia. EI-2 commenced its operation in 1958, and was shut down on December 28, 1990, having operated for the period of 33 years all together. The extra pure grade graphite for the moderator, water for the coolant, and uranium metal for the fuel were used in the reactor. During the operation nitrogen gas was passed through the graphite stack of the reactor. In the process of decommissioning the PDC UGR JSC site the cavities in the reactor space were filled with clay-based materials. A specific composite barrier material based on clays and minerals of Siberian Region was developed for the purpose. Numerical modeling demonstrated the developed clay composite would make efficient geological barriers preventing release of radionuclides into the environment. Copyright © 2018 Elsevier Ltd. All rights reserved.

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. Copyright © 2014 Elsevier Ltd. All rights reserved.

Grants Mining District

EPA Pesticide Factsheets

The Grants Mineral Belt was the focus of uranium extraction and production activities from the 1950s until the late 1990s. EPA is working with state, local, and federal partners to assess and address health risks and environmental effects of the mines

Economic geology of the Central City district, Gilpin County, Colorado

USGS Publications Warehouse

Sims, P.K.; Drake, Avery A.; Tooker, E.W.

1963-01-01

The Central City district, in Gilpin County, Colo., is on the east flank of the Front Range, about 30 miles west of Denver. The district is the most important mining camp in the Front Range mineral belt, and has yielded more than $100 million worth of gold, silver, uranium, and base-metal ores since 1859. Gold accounts for about 85 percent of the dollar value of the ore. In recent years mining activity has been slack but from 1950 to 1955 the search for uranium ores stimulated prospecting and development.

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

USGS Publications Warehouse

Landa, Edward R.

2004-01-01

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

Excess lead in "rusty rock" 66095 and implications for an early lunar differentiation

USGS Publications Warehouse

Nunes, P.D.; Tatsumoto, M.

1973-01-01

Apollo 16 breccia 66095 contains a remarkably high amount of lead (15 part's per million), 85 percent of which is not supported by uranium and thorium in the rock. An acid leach experiment coupled with separate analyses of the whole rock and mineral fractions for uranium, thorium, and lead indicate that the excess lead has a lunar source and was apparently introduced about 4.0 X 109 years ago. The data also suggest that a major lunar crustal differentiation occurred about 4.47 X 109 years ago.

Proteogenomic insights into uranium tolerance of a Chernobyl's Microbacterium bacterial isolate.

PubMed

Gallois, Nicolas; Alpha-Bazin, Béatrice; Ortet, Philippe; Barakat, Mohamed; Piette, Laurie; Long, Justine; Berthomieu, Catherine; Armengaud, Jean; Chapon, Virginie

2018-04-15

Microbacterium oleivorans A9 is a uranium-tolerant actinobacteria isolated from the trench T22 located near the Chernobyl nuclear power plant. This site is contaminated with different radionuclides including uranium. To observe the molecular changes at the proteome level occurring in this strain upon uranyl exposure and understand molecular mechanisms explaining its uranium tolerance, we established its draft genome and used this raw information to perform an in-depth proteogenomics study. High-throughput proteomics were performed on cells exposed or not to 10μM uranyl nitrate sampled at three previously identified phases of uranyl tolerance. We experimentally detected and annotated 1532 proteins and highlighted a total of 591 proteins for which abundances were significantly differing between conditions. Notably, proteins involved in phosphate and iron metabolisms show high dynamics. A large ratio of proteins more abundant upon uranyl stress, are distant from functionally-annotated known proteins, highlighting the lack of fundamental knowledge regarding numerous key molecular players from soil bacteria. Microbacterium oleivorans A9 is an interesting environmental model to understand biological processes engaged in tolerance to radionuclides. Using an innovative proteogenomics approach, we explored its molecular mechanisms involved in uranium tolerance. We sequenced its genome, interpreted high-throughput proteomic data against a six-reading frame ORF database deduced from the draft genome, annotated the identified proteins and compared protein abundances from cells exposed or not to uranyl stress after a cascade search. These data show that a complex cellular response to uranium occurs in Microbacterium oleivorans A9, where one third of the experimental proteome is modified. In particular, the uranyl stress perturbed the phosphate and iron metabolic pathways. Furthermore, several transporters have been identified to be specifically associated to uranyl stress, paving the way to the development of biotechnological tools for uranium decontamination. Copyright © 2017. Published by Elsevier B.V.

Igneous activity and related ore deposits in the western and southern Tushar Mountains, Marysvale volcanic field, west-central Utah

USGS Publications Warehouse

Steven, Thomas A.

1984-01-01

PART A: Igneous activity in the Marysvale volcanic field of western Utah can be separated into many episodes of extrusion, intrusion, and hydrothermal activity. The rocks of the western Tushar Mountains, near the western part of the volcanic field, include intermediate-composition, calc-alkalic volcanic rocks erupted from scattered volcanoes in Oligocene through earliest Miocene time and related monzonitic intrusions emplaced 24-23 m.y. ago. Beginning 22-21 m.y. ago and extending through much of the later Cenozoic, a bimodal basalt-rhyolite assemblage was erupted widely throughout the volcanic field. Only volcanic and intrusive rocks belonging to the rhyolitic end member of this bimodal assemblage are present in the western Tushar Mountains; most of these rocks either fill the Mount Belknap caldera (19 m.y. old) or are part of the rhyolite of Gillies Hill (9---8 m.y. old). Episodic hydrothermal activity altered and mineralized rocks at many places in the western Tushar Mountains during Miocene time. The earliest activity took place in and adjacent to monzonitic calcalkalic intrusions emplaced in the vicinity of Indian Creek and Cork Ridge. These rocks were widely propylitized, and gold-bearing quartz-pyrite-carbonate veins formed in local fractures. Hydrothermal activity associated with the Mount Belknap caldera mobilized and redeposited uranium contained in the caldera-fill rocks and formed primary concentrations of lithophile elements (including molybdenum and uranium) in the vicinity of intrusive bodies. Hydrothermal activity associated with the rhyolite of Gillies Hill altered and mineralized rocks at several places along the fault zone that marks the western margin of the Tushar Mountains; the zoned alunite and gold deposits at Sheep Rock, the gold deposit at the Sunday Mine, and an alunite deposit near Indian Creek were thus produced. Resetting of isotopic ages suggests that another center of hydrothermally altered rocks associated with a buried pluton about 16 m.y. old may exist near Indian Creek just west of the Mount Belknap caldera. Geophysical evidence confirms the probability of a buried pluton near Indian Creek, and also indicates that another buried pluton probably exists beneath the 9-m.y.-old mineralized area at Sheep Rock. The mineral potential of the different hydrothermal systems, and the types of minerals deposited probably vary considerably from one period of mineralization to another and from one depth environment to another within a given system. PART B: The Big John caldera, on the western flank of the Tushar Mountains in the Marysvale volcanic field in west-central Utah, formed 23-22 m.y. ago in response to ash-flow eruptions of the Delano Peak Tuff Member of the Bullion Canyon Volcanics. These eruptions were near the end of the period of Oligocene-early Miocene calc-alkalic igneous activity that built a broad volcanic plateau in this part of Utah. About 22 m.y. ago, the composition of rocks erupted changed to a bimodal assemblage of mafic and silicic volcanics that was erupted episodically through the remainder of Cenozoic time. The alkali rhyolites are uranium rich in part, and are associated with all the known uranium deposits in the Marysvale volcanic field. The Big John caldera was a broad drained basin whose floor was covered by a layer of stream gravels when ash flows from the western source area of the Mount Belknap Volcanics filled the caldera with the Joe Lott Tuff Member about 19 m.y. ago. Devitrified and zeolitized rocks in the caldera fill have lost one-quarter to one-half of the uranium contained in the original magma. This mobilized uranium probably moved into the hydrologic regime, and some may have been redeposited in stream gravels underlying the Joe Lott within the caldera, or in gravels filling the original drainage channel that extended south from the caldera.

Clay minerals trap hydrogen in the Earth's crust: Evidence from the Cigar Lake uranium deposit, Athabasca

NASA Astrophysics Data System (ADS)

Truche, Laurent; Joubert, Gilles; Dargent, Maxime; Martz, Pierre; Cathelineau, Michel; Rigaudier, Thomas; Quirt, David

2018-07-01

Hydrogen (H2)-rich fluids are observed in a wide variety of geologic settings including gas seeps in serpentinized ultramafic rocks, sub-seafloor hydrothermal vents, fracture networks in crystalline rocks from continental and oceanic crust, and volcanic gases. Natural hydrogen sources can sustain deep microbial ecosystems, induce abiotic hydrocarbons synthesis and trigger the formation of prebiotic organic compounds. However, due to its extreme mobility and small size, hydrogen is not easily trapped in the crust. If not rapidly consumed by redox reactions mediated by bacteria or suitable mineral catalysts it diffuses through the rocks and migrates toward the surface. Therefore, H2 is not supposed to accumulate in the crust. We challenge this view by demonstrating that significant amount of H2 may be adsorbed by clay minerals and remain trapped beneath the surface. Here, we report for the first time H2 content in clay-rich rocks, mainly composed of illite, chlorite, and kaolinite from the Cigar Lake uranium ore deposit (northern Saskatchewan, Canada). Thermal desorption measurements reveal that H2 is enriched up to 500 ppm (i.e. 0.25 mol kg-1 of rock) in these water-saturated rocks having a very low total organic content (<0.5 wt%). Such hydrogen uptake is comparable and even exceeds adsorbed methane capacities reported elsewhere for pure clay minerals or shales. Sudoite (Al-Mg di-trioctahedral chlorite) is probably the main mineral responsible for H2 adsorption in the present case. The presence of multiple binding sites in interlinked nanopores between crystal layers of illite-chlorite particles offers the ideal conditions for hydrogen sorption. We demonstrate that 4 to 17% of H2 produced by water radiolysis over the 1.4-Ga-lifetime of the Cigar Lake uranium ore deposit has been trapped in the surrounding clay alteration haloes. As a result, sorption processes on layered silicates must not be overlooked as they may exert an important control on the fate and mobility of H2 in the crust. Furthermore, the high capacity of clay minerals to sorb molecular hydrogen may also open up new opportunities for exploration of unexpected energy resources and for H2 storage based on geo-inspired materials.

A combined chemical, isotopic and microstructural study of pyrite from roll-front uranium deposits, Lake Eyre Basin, South Australia

NASA Astrophysics Data System (ADS)

Ingham, Edwina S.; Cook, Nigel J.; Cliff, John; Ciobanu, Cristiana L.; Huddleston, Adam

2014-01-01

The common sulfide mineral pyrite is abundant throughout sedimentary uranium systems at Pepegoona, Pepegoona West and Pannikan, Lake Eyre Basin, South Australia. Combined chemical, isotopic and microstructural analysis of pyrite indicates variation in fluid composition, sulfur source and precipitation conditions during a protracted mineralization event. The results show the significant role played by pyrite as a metal scavenger and monitor of fluid changes in low-temperature hydrothermal systems. In-situ micrometer-scale sulfur isotope analyses of pyrite demonstrated broad-scale isotopic heterogeneity (δ34S = -43.9 to +32.4‰VCDT), indicative of complex, multi-faceted pyrite evolution, and sulfur derived from more than a single source. Preserved textures support this assertion and indicate a genetic model involving more than one phase of pyrite formation. Authigenic pyrite underwent prolonged evolution and recrystallization, evidenced by a genetic relationship between archetypal framboidal aggregates and pyrite euhedra. Secondary hydrothermal pyrite commonly displays hyper-enrichment of several trace elements (Mn, Co, Ni, As, Se, Mo, Sb, W and Tl) in ore-bearing horizons. Hydrothermal fluids of magmatic and meteoric origins supplied metals to the system but the geochemical signature of pyrite suggests a dominantly granitic source and also the influence of mafic rock types. Irregular variation in δ34S, coupled with oscillatory trace element zonation in secondary pyrite, is interpreted in terms of continuous variations in fluid composition and cycles of diagenetic recrystallization. A late-stage oxidizing fluid may have mobilized selenium from pre-existing pyrite. Subsequent restoration of reduced conditions within the aquifer caused ongoing pyrite re-crystallization and precipitation of selenium as native selenium. These results provide the first qualitative constraints on the formation mechanisms of the uranium deposits at Beverley North. Insights into depositional conditions and sources of both sulfide and uranium mineralization and an improved understanding of pyrite geochemistry can also underpin an effective vector for uranium exploration at Beverley North and other sedimentary systems of the Lake Eyre Basin, as well as in comparable geological environments elsewhere. Average intensity of 32S signal in counts per second × 108.Drift corrected 34S/32S prior to IMF calibration.Two-sigma propagated uncertainty on individual measurements.

Uranium in groundwater - A synopsis based on a large hydrogeochemical data set.

PubMed

Riedel, Thomas; Kübeck, Christine

2018-02-01

Most of the knowledge on the occurrence of Uranium (U) in groundwater comes from in-situ manipulation experiments in the field, computational modelling studies or from laboratory analyses where individual processes of U mobilization were studied in isolation. Because of Uranium's vital redox chemistry it interacts, often simultaneously, with many other element cycles (e.g., sulfur, carbon, iron, and manganese) making it difficult to predict U concentrations in natural environments. For the present study a large data set was analyzed to predict the occurrence of U in groundwater from basic hydrochemistry. The data set consists of more than 8000 chemical groundwater analyses (including Uranium concentrations) from more than 2000 sampling locations. A strong relation between U concentrations and electric conductivity as well as alkalinity was observed, suggesting that weathering of geogenic source material and desorption from mineral surfaces is the principle mechanism of U release. Except for aquifers with strongly reducing conditions this process leads to a slow but continuous accumulation of U in groundwater in most cases. Importantly, the occurrence of U is modulated by the prevailing redox conditions in an aquifer. Uranium concentrations were moderate under oxic conditions and highest under manganese and nitrate-reducing conditions (heterotrophic as wells as autotrophic nitrate reduction). Only in iron- and sulfate-reducing groundwater the probability of U concentrations above 1 μg l -1 was virtually zero, as these ground waters act as U sinks. The combination of mineral weathering (especially carbonates) with mobilization of U under manganese and nitrate reducing conditions results in the highest risk of detecting U. In contrast, a low risk is associated with low pH (<7) and low mineralization of groundwater, which is the case in granitic catchments, for example. Our results further provide evidence, that agricultural practices such as liming, use of fertilizers and irrigation influence the occurrence of U in groundwater in multiple ways. Accurate management of aquifers underlying farmland will therefore become more and more important in the future. In summary, we find that the vulnerability of an aquifer to elevated U concentrations cannot be explained by a single factor. This complicates efforts to target elevated U concentrations in groundwaters that are abstracted for drinking water production. Copyright © 2017 Elsevier Ltd. All rights reserved.

Heavy metal mining using microbes.

PubMed

Rawlings, Douglas E

2002-01-01

The use of acidiphilic, chemolithotrophic iron- and sulfur-oxidizing microbes in processes to recover metals from certain types of copper, uranium, and gold-bearing minerals or mineral concentrates is now well established. During these processes insoluble metal sulfides are oxidized to soluble metal sulfates. Mineral decomposition is believed to be mostly due to chemical attack by ferric iron, with the main role of the microorganisms being to reoxidize the resultant ferrous iron back to ferric iron. Currently operating industrial biomining processes have used bacteria that grow optimally from ambient to 50 degrees C, but thermophilic microbes have been isolated that have the potential to enable mineral biooxidation to be carried out at temperatures of 80 degrees C or higher. The development of higher-temperature processes will extend the variety of minerals that can be commercially processed.

In-situ, time resolved monitoring of uranium in BFS:OPC grout. Part 1: Corrosion in water vapour.

PubMed

Stitt, C A; Paraskevoulakos, C; Banos, A; Harker, N J; Hallam, K R; Davenport, A; Street, S; Scott, T B

2017-08-11

Uranium encapsulated in grout was exposed to water vapour for extended periods of time. Through synchrotron x-ray powder diffraction and tomography measurements, uranium dioxide was determined the dominant corrosion product over a 50-week time period. The oxide growth rate initiated rapidly, with rates comparable to the U + H 2 O reaction. Over time, the reaction rate decreased and eventually plateaued to a rate similar to the U + H 2 O + O 2 reaction. This behaviour was not attributed to oxygen ingress, but instead the decreasing permeability of the grout, limiting oxidising species access to the metal surface.

Trace Uranium Partitioning in a Multiphase Nano-FeOOH System.

PubMed

McBriarty, Martin E; Soltis, Jennifer A; Kerisit, Sebastien; Qafoku, Odeta; Bowden, Mark E; Bylaska, Eric J; De Yoreo, James J; Ilton, Eugene S

2017-05-02

The characterization of trace elements in minerals using extended X-ray absorption fine structure (EXAFS) spectroscopy constitutes a first step toward understanding how impurities and contaminants interact with the host phase and the environment. However, limitations to EXAFS interpretation complicate the analysis of trace concentrations of impurities that are distributed across multiple phases in a heterogeneous system. Ab initio molecular dynamics (AIMD)-informed EXAFS analysis was employed to investigate the immobilization of trace uranium associated with nanophase iron (oxyhydr)oxides, a model system for the geochemical sequestration of radiotoxic actinides. The reductive transformation of ferrihydrite [Fe(OH) 3 ] to nanoparticulate iron oxyhydroxide minerals in the presence of uranyl (UO 2 ) 2+ (aq) resulted in the preferential incorporation of U into goethite (α-FeOOH) over lepidocrocite (γ-FeOOH), even though reaction conditions favored the formation of excess lepidocrocite. This unexpected result is supported by atomically resolved transmission electron microscopy. We demonstrate how AIMD-informed EXAFS analysis lifts the strict statistical limitations and uncertainty of traditional shell-by-shell EXAFS fitting, enabling the detailed characterization of the local bonding environment, charge compensation mechanisms, and oxidation states of polyvalent impurities in complex multiphase mineral systems.

Trace Uranium Partitioning in a Multiphase Nano-FeOOH System

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

McBriarty, Martin E.; Soltis, Jennifer A.; Kerisit, Sebastien

The characterization of trace elements in minerals using extended X-ray absorption fine structure (EXAFS) spectroscopy constitutes a first step toward understanding how impurities and contaminants interact with the host phase and the environment. However, limitations to EXAFS interpretation complicate the analysis of trace concentrations of impurities that are distributed across multiple phases in a heterogeneous system. Ab initio molecular dynamics (AIMD)-informed EXAFS analysis was employed to investigate the immobilization of trace uranium associated with nanophase iron (oxyhydr)oxides, a model system for the geochemical sequestration of radiotoxic actinides. The reductive transformation of ferrihydrite [Fe(OH)3] to nanoparticulate iron oxyhydroxide minerals in themore » presence of uranyl (UO 2) 2+(aq) resulted in the preferential incorporation of U into goethite (α-FeOOH) over lepidocrocite (γ-FeOOH), even though reaction conditions favored the formation of excess lepidocrocite. This unexpected result is supported by atomically resolved transmission electron microscopy. We demonstrate how AIMD-informed EXAFS analysis lifts the strict statistical limitations and uncertainty of traditional shell-by-shell EXAFS fitting, enabling the detailed characterization of the local bonding environment, charge compensation mechanisms, and oxidation states of polyvalent impurities in complex multiphase mineral systems.« less

Efficacy of hair analysis for monitoring exposure to uranium: a mini-review.

PubMed

Joksić, Agnes Šömen; Katz, Sidney A

2014-01-01

In spite of the ease with which samples may be collected and the stability of the samples after collection, the use of hair mineral analysis for monitoring environmental exposures and evaluating heavy metal poisonings has remained controversial since its initial applications for these purposes in the early 1950s. Among the major arguments against using hair mineral analysis in general were the absence of biokinetic models and/or metabolic data that adequately described the incorporation of trace elements into the hair, the absence of correlations between the concentrations of trace elements in the hair and their concentrations in other tissues, the inability to distinguish between trace elements that were deposited in the hair endogenously and those that were deposited on the hair exogenously, the absence of reliable reference ranges for interpreting the results of hair mineral analysis and a lack of standard procedures for the collecting, preparing and analyzing the hair samples. The developments of the past two decades addressing these objections are reviewed here, and arguments supporting the use of hair analysis for monitoring environmental and/or occupational exposures to uranium are made on the basis of the information presented in this review.

Reconnaissance for radioactive materials in northeastern United States during 1952

USGS Publications Warehouse

McKeown, Francis A.; Klemic, Harry

1953-01-01

Reconnaissance for radioactive materials was made in parts of Maine, New York, New Jersey, and Pennsylvania. The primary objective was to examine the iron ore deposits and associated rocks in the Adirondack Mountains of New York and the Highlands of New Jersey. In addition, several deposits known or reported to contain radioactive minerals were examined to delimit their extent. Most of the deposits examined are not significant as possible sources of radioactive elements and the data pertaining to them are summarized in table form. Deposits that do warrant more description than can be given in table form are: Benson Mines, St. Lawrence County, N. Y.; Rutgers mine, Clinton County, N. Y.; Mineville Mines, Essex County, N. Y.l Canfield phosphate mine, Morris County, N. J.; Mullgan quarry, Hunterdon County, N. J.; and the Chestnut Hill-Marble Mountain area, Pennsylvania and New Jersey. The Old Bed in the Mineville district is the only deposit that may be economically significant. Apatite from Old Bed ore contains as much as 4.9 percent total rare earth. 0.04 percent thorium, and 0.018 percent uranium. Magnetite ore at the Rutgers mine contains radioactive zircon and apatite. Radioactivity measurements of outcrops and dump material show that the ore contains from 0.005 to 0.010 percent equivalent uranium. One sample of lean magnetite ore contains 0.006 percent equivalent uranium. Garnet-rich zones in the Benson Mines magnetite deposit contain as much as 0.017 equivalent uranium. Most of the rock and ore, however, contains about 0.005 percent equivalent uranium. Available data indicate that the garnet-rich zones are enriched in radioactive allanite. A shear zone in the Kittatinny limestone of Cambrian age at the Mulligan quarry contains uraniferous material. Radioactivity anomalies elsewhere in the quarry and in adjacent fields indicate that there may be other uraniferous shear zones. Assays of samples and measurements of outcrop radioactivity indicate that the uranium content of these zones is low; samples contain from 0.008 to 0.068 percent equivalent uranium. The anomalies, however, may indicate greater concentrations of uranium below surficial leached zones. The Chestnut Hill-Marble Mountain area contains radioactivity anomalies for about 2 miles along the strike of the contact of pre-Cambrian Pickering gneiss and Franklin limestone formations. In places this contact is injected with pegmatite, which probably was the source of the radioelements. The most favorable area for further study is at Marble Mountain, where a nearly continuous anomaly extends for about 1500 feet. Samples from part of this area contain as much as 0.044 percent equivalent uranium and 0.005 percent uranium. Radioactive hematite and florencite, in which thorium may have substituted for cerium, are the only radioactive minerals observed in the Marble Mountain area.

Hydrocarbon-mediated gold and uranium concentration in the Witwatersrand Basin, South Africa

NASA Astrophysics Data System (ADS)

Fuchs, Sebastian; Williams-Jones, Anthony; Schumann, Dirk; Couillard, Martin; Murray, Andrew

2016-04-01

The Witwatersrand deposits in South Africa represent the largest repository of gold in the World and a major resource of uranium. The genesis of the gold and uranium ores in the quartz-pebble conglomerates (reefs), however, is still a matter of considerable discussion. Opinion has been divided over whether they represent paleo-placers that have been partly remobilised by hydrothermal fluids or if the mineralisation is entirely hydrothermal in origin. In addition, recently published models have proposed a syngenetic origin for the gold involving bacterially-mediated precipitation from meteoric water and shallow seawater. An important feature of the gold and uranium mineralisation in the reefs is the strong spatial association with organic matter. In some reefs, up to 70% of the gold and almost the entire uranium resource is spatially associated with pyrobitumen seams, suggesting a genetic relationship of the gold-uranium mineralisation with hydrocarbons. Here we report results of a study of the Carbon Leader Reef, using high-resolution scanning and transmission electron microscopy (SEM / TEM) and LA-ICP-MS that provide new insights into the role of hydrocarbons in the concentration of the gold and uranium. A detailed examination revealed gold monocrystals containing numerous rounded or elliptical inclusions filled with pyrobitumen. We interpret these inclusions to record the crystallisation of the gold around droplets of a hydrocarbon liquid that migrated through the Witwatersrand basin, and was converted to pyrobitumen by being heated. We propose that the gold was transported in a hydrothermal fluid as a bisulphide complex and that this fluid mixed with the hydrocarbon liquid to form a water-oil emulsion. The interaction between the two fluids caused a sharp reduction in fO2 at the water-oil interface, which destabilised the gold-bisulphide complexes, causing gold monocrystals to precipitate around the oil droplets. In contrast to the gold, uraninite, the principal uranium mineral, occurs as complex-shaped grains that represent aggregates containing billions of uraninite nanocrystals (5 - 7 nm in diameter), which grew in situ in the pyrobitumen matrix or more likely its liquid precursor (Fuchs et al., 2015). This in situ growth of isolated nanocrystalline aggregates shows that uranium was mobilised and concentrated by liquid hydrocarbons, and that uraninite nanocrystals were released from the oils during the conversion of oil to pyrobitumen. Our study provides new insights into the complex mechanisms of ore formation in the Witwatersrand Supergroup and compelling evidence that hydrocarbons played a major role in the concentration of the gold and uranium. It does not rule out the possibility that gold and uranium were introduced into the Witwatersrand Basin as detrital grains but shows that mobilisation of gold and uranium by hydrothermal fluids and hydrocarbon liquids, respectively, and the mixing of these fluids, were essential to ore formation. Fuchs, S., Schumann, D., Williams-Jones, A.E., Vali, H., 2015. The growth and concentration of uranium and titanium minerals in hydrocarbons of the Carbon Leader Reef, Witwatersrand Supergroup, South Africa. Chemical Geology 393-394, 55-66.

28 CFR 79.41 - Definitions.

Code of Federal Regulations, 2010 CFR

2010-07-01

..., surgery, and thoracic surgery (and including subspecialties such as cardiovascular disease, medical... Criteria for Claims by Uranium Miners § 79.41 Definitions. (a) Cor pulmonale means heart disease, including... Compensation Program upon request. (g) Nonmalignant respiratory disease means fibrosis of the lung, pulmonary...

Application of self-organizing maps to the study of U-Zr-Ti-Nb distribution in sandstone-hosted uranium ores

NASA Astrophysics Data System (ADS)

Klus, Jakub; Pořízka, Pavel; Prochazka, David; Mikysek, Petr; Novotný, Jan; Novotný, Karel; Slobodník, Marek; Kaiser, Jozef

2017-05-01

This paper presents a novel approach for processing the spectral information obtained from high-resolution elemental mapping performed by means of Laser-Induced Breakdown Spectroscopy. The proposed methodology is aimed at the description of possible elemental associations within a heterogeneous sample. High-resolution elemental mapping provides a large number of measurements. Moreover, typical laser-induced plasma spectrum consists of several thousands of spectral variables. Analysis of heterogeneous samples, where valuable information is hidden in a limited fraction of sample mass, requires special treatment. The sample under study is a sandstone-hosted uranium ore that shows irregular distribution of ore elements such as zirconium, titanium, uranium and niobium. Presented processing methodology shows the way to reduce the dimensionality of data and retain the spectral information by utilizing self-organizing maps (SOM). The spectral information from SOM is processed further to detect either simultaneous or isolated presence of elements. Conclusions suggested by SOM are in good agreement with geological studies of mineralization phases performed at the deposit. Even deeper investigation of the SOM results enables discrimination of interesting measurements and reveals new possibilities in the visualization of chemical mapping information. Suggested approach improves the description of elemental associations in mineral phases, which is crucial for the mining industry.

Toxicological Evaluation of Depleted Uranium in Rats: Six-Month Evaluation Point

DTIC Science & Technology

1998-02-01

mild renal dysfunction with increased urinary excretion of beta2-microglobulin and various amino acids. In rats exposed subchronically to low doses...reabsorption. Urinary enzymes are sen- sitive, non-invasive markers of toxicity primarily in the kidney tubules [46]. NAG is a lysosomal enzyme found...studies. Environmental Research 61:323-336 42. Neuman WF (1950) Urinary uranium as a meas- ure of exposure hazard. Industrial Medicine and Surgery 19

Laboratory column experiments and transport modeling to evaluate retardation of uranium in an aquifer downgradient of a uranium in-situ recovery site

DOE PAGES

Dangelmayr, Martin A.; Reimus, Paul W.; Wasserman, Naomi L.; ...

2017-05-01

The purpose of this study was to determine the attenuation potential and retardation of uranium in sediments taken from boreholes at the Smith-Ranch Highland in-situ recovery (ISR) site. Five column experiments with four different sediments were conducted to study the effects of variable mineralogy and alkalinity on uranium breakthrough. Uranium transport was modeled with PHREEQC using a generalized composite surface complexation model (GC SCM) with one, two, and, three generic surfaces, respectively. Reactive surface areas were approximated with PEST using BET derived surface areas to constrain fitting parameters. Uranium breakthrough was delayed by a factor of 1.68, 1.69 and 1.47more » relative to the non-reactive tracer for three of the 5 experiments at an alkalinity of 540 mg/l. A sediment containing smectite and kaolinite retained uranium by a factor of 2.80 despite a lower measured BET surface area. Decreasing alkalinity to 360 mg/l from 540 mg/l increased retardation by a factor of 4.26. Model fits correlated well to overall BET surface area in the three columns where clay content was less than 1%. For the sediment with clay, models consistently understated uranium retardation when reactive surface sites were restricted by BET results. Calcite saturation was shown to be a controlling factor for uranium desorption as the pH of the system changes. A pH of 6 during a secondary background water flush remobilized previously sorbed uranium resulting in a secondary uranium peak at twice the influent concentrations. Furthermore, this study demonstrates the potential of GC SCM models to predict uranium transport in sediments with homogenous mineral composition, but highlights the need for further research to understand the role of sediment clay composition and calcite saturation in uranium transport.« less

Laboratory column experiments and transport modeling to evaluate retardation of uranium in an aquifer downgradient of a uranium in-situ recovery site

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

Dangelmayr, Martin A.; Reimus, Paul W.; Wasserman, Naomi L.

The purpose of this study was to determine the attenuation potential and retardation of uranium in sediments taken from boreholes at the Smith-Ranch Highland in-situ recovery (ISR) site. Five column experiments with four different sediments were conducted to study the effects of variable mineralogy and alkalinity on uranium breakthrough. Uranium transport was modeled with PHREEQC using a generalized composite surface complexation model (GC SCM) with one, two, and, three generic surfaces, respectively. Reactive surface areas were approximated with PEST using BET derived surface areas to constrain fitting parameters. Uranium breakthrough was delayed by a factor of 1.68, 1.69 and 1.47more » relative to the non-reactive tracer for three of the 5 experiments at an alkalinity of 540 mg/l. A sediment containing smectite and kaolinite retained uranium by a factor of 2.80 despite a lower measured BET surface area. Decreasing alkalinity to 360 mg/l from 540 mg/l increased retardation by a factor of 4.26. Model fits correlated well to overall BET surface area in the three columns where clay content was less than 1%. For the sediment with clay, models consistently understated uranium retardation when reactive surface sites were restricted by BET results. Calcite saturation was shown to be a controlling factor for uranium desorption as the pH of the system changes. A pH of 6 during a secondary background water flush remobilized previously sorbed uranium resulting in a secondary uranium peak at twice the influent concentrations. Furthermore, this study demonstrates the potential of GC SCM models to predict uranium transport in sediments with homogenous mineral composition, but highlights the need for further research to understand the role of sediment clay composition and calcite saturation in uranium transport.« less

The effect of bicarbonate on the microbial dissolution of autunite mineral in the presence of gram-positive bacteria.

PubMed

Sepulveda-Medina, Paola M; Katsenovich, Yelena P; Wellman, Dawn M; Lagos, Leonel E

2015-06-01

Bacteria are key players in the processes that govern fate and transport of contaminants. The uranium release from Na and Ca-autunite by Arthrobacter oxydans strain G968 was evaluated in the presence of bicarbonate ions. This bacterium was previously isolated from Hanford Site soil and in earlier prescreening tests demonstrated low tolerance to U(VI) toxicity compared to other A. oxydans isolates. Experiments were conducted using glass serum bottles as mixed bioreactors and sterile 6-well cell culture plates with inserts separating bacteria cells from mineral solids. Reactors containing phosphorus-limiting media were amended with bicarbonate ranging between 0 and 10 mM and meta-autunite solids to provide a U(VI) concentration of 4.4 mmol/L. Results showed that in the presence of bicarbonate, A. oxydans G968 was able to enhance the release of U(VI) from Na and Ca autunite at the same capacity as other A. oxydans isolates with relatively high tolerance to U(VI). The effect of bacterial strains on autunite dissolution decreases as the concentration of bicarbonate increases. The results illustrate that direct interaction between the bacteria and the mineral is not necessary to result in U(VI) biorelease from autunite. The formation of secondary calcium-phosphate mineral phases on the surface of the mineral during the dissolution can ultimately reduce the natural autunite mineral contact area, which bacterial cells can access. This thereby reduces the concentration of uranium released into the solution. This study provides a better understanding of the interactions between meta-autunite and microbes in conditions mimicking arid and semiarid subsurface environments of western U.S. Copyright © 2015 Elsevier Ltd. All rights reserved.

The Effect of Bicarbonate on the Microbial Dissolution of Autunite Mineral in the Presence of Gram-Positive Bacteria

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

Sepulveda-Medina, Paola; Katsenovich, Yelena; Wellman, Dawn M.

Bacteria are key players in the processes that govern fate and transport of contaminants. The uranium release from Na and Ca-autunite by Arthrobacter oxydans strain G968 was evaluated in the presence of bicarbonate ions. This bacterium was previously isolated from Hanford Site soil and in earlier prescreening tests demonstrated low tolerance to U(VI) toxicity compared to other A.oxydans isolates. Experiments were conducted using glass serum bottles as mixed bioreactors and sterile 6-well cell culture plates with inserts separating bacteria cells from mineral solids. Reactors containing phosphorus-limiting media were amended with bicarbonate ranging between 0-10 mM and metaautunite solids to providemore » a U(VI) concentration of 4.4 mmol/L. Results showed that in the presence of bicarbonate, A.oxydans G968 was able to enhance the release of U(VI) from Na and Ca autunite at the same capacity as other A.oxydans isolates with relatively high tolerance to U(VI). The effect of bacterial strains on autunite dissolution decreases as the concentration of bicarbonate increases. The results illustrate that direct interaction between the bacteria and the mineral is not necessary to result in U (VI) biorelease from autunite. The formation of secondary calcium-phosphate mineral phases on the surface of the mineral during the dissolution can ultimately reduce the natural autunite mineral contact area, which bacterial cells can access. This thereby reduces the concentration of uranium released into the solution. This study provides a better understanding of the interactions between meta-autunite and microbes in conditions mimicking arid and semiarid subsurface environments of western U.S.« less

Formation of secondary minerals in a lysimeter approach - A mineral-microbe interaction

NASA Astrophysics Data System (ADS)

Schäffner, F.; Merten, D.; De Giudici, G.; Beyer, A.; Akob, D. M.; Ricci, P. C.; Küsel, K.; Büchel, G.

2012-04-01

Heavy metal contamination of large areas due to uranium mining operations poses a serious long-term environmental problem. In the Ronneburg district (eastern Thuringia, Germany), leaching of low grade uranium bearing ores (uranium content < 300 g/t) occurred from 1972 to 1990 using acid mine drainage (AMD; pH 2.7-2.8) and diluted sulphuric acid (10 g/l). Secondary mineral phases like birnessite, todorokite and goethite occur within a natural attenuation process associated with enrichment of heavy metals, especially Cd, Ni, Co, Cu and Zn due to a residual contamination even after remediation efforts. To reveal the processes of secondary mineral precipitation in the field a laboratory lysimeter approach was set up under in situ-like conditions. Homogenized soil from the field site and pure quartz sand were used as substrates. In general, in situ measurements of redox potentials in the substrates showed highly oxidizing conditions (200-750 mV). Water was supplied to the lysimeter from below via a mariottés bottle containing contaminated groundwater from the field. Evaporation processes were allowed, providing a continuous flow of water. This led to precipitation of epsomite and probably aplowite on the top layer of substrate, similar to what is observed in field investigations. After 4 weeks, the first iron and manganese bearing secondary minerals became visible. Soil water samples were used to monitor the behaviour of metals within the lysimeter. Saturation indices (SI) for different secondary minerals were calculated with PHREEQC. The SI of goethite showed oversaturation with respect to the soil solution. SEM-EDX analyses and IR spectroscopy confirmed the formation of goethite. Geochemical data revealed that goethite formation was mainly dominated by Eh/pH processes and that heavy metals, e.g. Zn and U, could be enriched in this phase. Although Eh/pH data does not support formation of manganese minerals, Mn(II)-oxidizing bacteria (MOB) could be isolated from field soil samples, supporting the fact that microorganisms may influence this natural attenuation process. Laser ablation ICP-MS data reveal accumulation of manganese in MOB biomass on Mn(II)-containing agar plates. Furthermore, it was possible to show the importance of iron on this process, as some MOB isolates were able to oxidize manganese independently from the iron content, whereas some are not. The latter isolates are only able to oxidize manganese if iron is present in the media. In the lysimeter, SEM-EDX data showed microorganisms in organic rich phases together with the occurrence of manganese, oxygen, and nickel, indicating manganese oxides enriched in nickel. Although this new mineral phases could not yet be identified microprobe EDX results from polished thin sections showed needle-like mineral structures that are similar to the birnessite and todorokite samples observed from field samples. Hence, the lysimeter experiment revealed that the formation of iron and manganese minerals that are involved in heavy metal natural attenuation is result of both abiotic and biotic processes.

Bio-precipitation of uranium by two bacterial isolates recovered from extreme environments as estimated by potentiometric titration, TEM and X-ray absorption spectroscopic analyses.

PubMed

Merroun, Mohamed L; Nedelkova, Marta; Ojeda, Jesus J; Reitz, Thomas; Fernández, Margarita López; Arias, José M; Romero-González, María; Selenska-Pobell, Sonja

2011-12-15

This work describes the mechanisms of uranium biomineralization at acidic conditions by Bacillus sphaericus JG-7B and Sphingomonas sp. S15-S1 both recovered from extreme environments. The U-bacterial interaction experiments were performed at low pH values (2.0-4.5) where the uranium aqueous speciation is dominated by highly mobile uranyl ions. X-ray absorption spectroscopy (XAS) showed that the cells of the studied strains precipitated uranium at pH 3.0 and 4.5 as a uranium phosphate mineral phase belonging to the meta-autunite group. Transmission electron microscopic (TEM) analyses showed strain-specific localization of the uranium precipitates. In the case of B. sphaericus JG-7B, the U(VI) precipitate was bound to the cell wall. Whereas for Sphingomonas sp. S15-S1, the U(VI) precipitates were observed both on the cell surface and intracellularly. The observed U(VI) biomineralization was associated with the activity of indigenous acid phosphatase detected at these pH values in the absence of an organic phosphate substrate. The biomineralization of uranium was not observed at pH 2.0, and U(VI) formed complexes with organophosphate ligands from the cells. This study increases the number of bacterial strains that have been demonstrated to precipitate uranium phosphates at acidic conditions via the activity of acid phosphatase. Copyright © 2011 Elsevier B.V. All rights reserved.

Hydrothermal synthesis of (C6N2H14)2(UVI2UIVO4F12), a mixed-valent one-dimensional uranium oxyfluoride.

PubMed

Allen, S; Barlow, S; Halasyamani, P S; Mosselmans, J F; O'Hare, D; Walker, S M; Walton, R I

2000-08-21

A new hybrid organic-inorganic mixed-valent uranium oxyfluoride, (C6N2H14)2(U3O4F12), UFO-17, has been synthesized under hydrothermal conditions using uranium dioxide as the uranium source, hydrofluoric acid as mineralizer, and 1,4-diazabicyclo[2.2.2]octane as template. The single-crystal X-ray structure was determined. Crystals of UFO-17 belonged to the orthorhombic space group Cmcm (no. 63), with a = 14.2660(15) A, b = 24.5130(10) A, c = 7.201(2) A, and Z = 4. The structure reveals parallel uranium-containing chains of two types: one type is composed of edge-sharing UO2F5 units; the other has a backbone of edge-sharing UF8 units, each sharing an edge with a pendant UO2F5 unit. Bond-valence calculations suggest the UF8 groups contain UIV, while the UO2F5 groups contain UVI. EXAFS data give results consistent with the single-crystal X-ray structure determination, while comparison of the uranium LIII-edge XANES of UFO-17 with that of related UIV and UVI compounds supports the oxidation-state assignment. Variable-temperature magnetic susceptibility measurements on UFO-17 and a range of related hybrid organic-inorganic uranium(IV) and uranium(VI) fluorides and oxyfluorides further support the formulation of UFO-17 as a mixed-valent UIV/UVI compound.

The combined effect of uranium and gamma radiation on biological responses and oxidative stress induced in Arabidopsis thaliana.

PubMed

Vanhoudt, Nathalie; Vandenhove, Hildegarde; Horemans, Nele; Wannijn, Jean; Van Hees, May; Vangronsveld, Jaco; Cuypers, Ann

2010-11-01

Uranium never occurs as a single pollutant in the environment, but always in combination with other stressors such as ionizing radiation. As effects induced by multiple contaminants can differ markedly from the effects induced by the individual stressors, this multiple pollution context should not be neglected. In this study, effects on growth, nutrient uptake and oxidative stress induced by the single stressors uranium and gamma radiation are compared with the effects induced by the combination of both stressors. By doing this, we aim to better understand the effects induced by the combined stressors but also to get more insight in stressor-specific response mechanisms. Eighteen-day-old Arabidopsis thaliana seedlings were exposed for 3 days to 10 muM uranium and 3.5 Gy gamma radiation. Gamma radiation interfered with uranium uptake, resulting in decreased uranium concentrations in the roots, but with higher transport to the leaves. This resulted in a better root growth but increased leaf lipid peroxidation. For the other endpoints studied, effects under combined exposure were mostly determined by uranium presence and only limited influenced by gamma presence. Furthermore, an important role is suggested for CAT1/2/3 gene expression under uranium and mixed stressor conditions in the leaves.

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

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

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, particle size, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population andmore » composition, which mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfatereducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. The results of this study suggest that reductive immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

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

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population and composition, whichmore » mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. Lastly, the results of this study suggest that immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

DOE PAGES

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.; ...

2016-12-29

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population and composition, whichmore » mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. Lastly, the results of this study suggest that immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less