Some physio-graphical keys to interpret reservoirs-traps, hosts of uranium-bearing mineralizations

International Nuclear Information System (INIS)

Parize, O.; Feybesse, J.L.; Wattinne-Morice, A.; Benedicto, A.; Richard, Y.; Sol, R.; Milesi, J.P.; Duchemin, Ch.; James, O.; Girard, Ch.

2009-01-01

As an approach in the search for silici-clastic formations which are reservoirs-traps hosting uranium-bearing mineralizations, the authors describe the use of facies sedimentology to describe successive deposits the arrangement of which determines the sequences according to which mineralisation will preferentially concentrate. They describe the use of sequential stratigraphy and how uranium had moved and deposited in successive eras and formations. They illustrate this approach by discussing different uranium-bearing deposits located in Niger and in France. They show how diagenesis, tectonics and sedimentology are combined to analyse these sites, and even to reassess them while exploiting them

Study of petrological characteristics of uranium-bearing sandstone in the south of ordos basin, China

International Nuclear Information System (INIS)

Tian Cheng; Jia Licheng; Li Song; Zhang Zimin

2007-01-01

This paper discusses the relation between uranium-bearing abundance and texture constituent of sedimentary rock, on the basis of the research of petrological characteristic of sandstone in the south of Ordos basin. The influence of infiltration of sandstone and uranium migration and accumulation by the major diagenesis of compaction and cementation, clay minerals evolution, corrosion and forming of secondary porosity are discussed. Uranium-bearing sandstones are divided into four types and their petrological characteristics are discussed. After mineralization conditions being summed up, the uranium-mineralization model of sandstone-type is built. Reliable petrological evidences for evaluating favourable uranium mineralization rich areas are furnished. (authors)

Results of geochemical and mineralogical studies on uranium in Zechstein copper-bearing strata from Lubin-Polkowice area

International Nuclear Information System (INIS)

Bareja, E.

1977-01-01

The paper presents the results of geochemical and mineralogical studies on uranium in Zechstein copper-bearing strata from the Lubin-Polkowice area. It was found that particular lithofacial varietes of Zechstein copper-bearing strata are characterized by different concentration of uranium. The mineralogical studies made possible determination of the nature of uranium mineralization and the interdependence between uranium and lithology of copper-bearing strata. An interesting uranium mineralization was found in tectonic breccias which yield black blende and schroeckingerite as well as calcite, gypsum, pyrite, hematite and geothite. Secondary minerals such as schroeckingerite and geothite evidence intense weathering processes acting in the copper deposit. The highest value of geochemical background of uranium in the copper-bearing series is displayed by basel copper-bearing shales (so called pitch-black shales) - 68.10 x 10 -40 /0 U. Statistical distribution of that element is unimodal. Distribution of uranium is polymodal in basal sandstones of the copper-bearing series. The geochemical background of red-coloured sandstones (Rotliegendes) is low, equalling 0.39 x 10 40 /0 U, whilst that of gray-coloured sandstones (Zechstein) - 2.32 x 10 -40 /0 U. An anomallous population (344.0 x 10 -40 /0 U) found in the case of gray sandstones of the Lubin-Polkowice area evidences the effects of secondary processes on concentration of uranium. In sandstones occur black blende, carburanes as well as calcite, hematite and goethite. A bimodal distribution of uranium was found in carbonate series. Limestones are characterized by low value of geochemical background (Dsub(x1) = 0.78 x 10 -40 /0 U) whilst dolomites by markedly higher values of the background (Dsub(x2) = 2.73 x 10 -40 /0 U). (author)

Radioactive equilibrium of uranium-bearing ores in some problems of applied geology

International Nuclear Information System (INIS)

Coulomb, R.; Girard, Ph.; Goldsztein, M.

1964-01-01

The state of equilibrium between several nuclides in radioactive relationship is determined with accuracy by the fundamental equations of radioactivity. It can be measured physically and expressed in suitable and internationally adopted units; Equilibrium - disequilibrium of uranium-bearing ores is a fairly complex phenomenon but the problem can be much simplified by well-chosen approximations in various practical field cases. The results of radiometric and radiochemical measurements lead to the interpretation of geochemical anomalies and may be used in the qualitative and quantitative estimation of uranium bearing deposits. (authors) [fr

Evaluation of the uranium potential of the Bushveld Complex

International Nuclear Information System (INIS)

Cheney, E.S.

1986-04-01

The poor quality of the airborne radiometric surveys and the lack of exploration geochemical data in the public domain prevent a satisfactory assessment of the uranium potential of the Bushveld area. Undue reliance must be placed upon fitting models of uranium ore deposits to the geology of the Bushveld area. Although the Bushveld granites have an unusually high background of uranium (20 to 40 ppm), they probably only host small vein-type deposits. The vein at the Albert Silver mine should be investigated as a type example to determine if it is only economic in the narrow interval of supergene enrichment. The Rooiberg Group has considerable potential for caldera-related deposits and for uranium-bearing sulphide deposits (including Olympic Dam-type deposits) in sedimentary interbeds. The Loskop Formation appears to be correlative with the Glentig and lower Swaershoek Formations of the Waterberg area. The Waterberg Group is the logical host to investigate for giant uncomformity/vein-type uranium deposits like those in Canada and Australia. Because the Waterberg consists of four uncomformity-bounded sequences, it is rarely more than 3 km thick; all of the sequences could be younger than 1770 Ma

A Convenient Method for Estimation of the Isotopic Abundance in Uranium Bearing Samples

International Nuclear Information System (INIS)

AI -Saleh, F.S.; AI-Mukren, Alj.H.; Farouk, M.A.

2008-01-01

A convenient and simple method for estimation of the isotopic abundance in some uranium bearing samples using gamma-ray spectrometry is developed using a hyper pure germanium spectrometer and a standard uranium sample with known isotopic abundance

Distinguishing of uranium-bearing sandstone by the geochemical characteristics in northern Sichuan

International Nuclear Information System (INIS)

Wang Wangzhang; Zhang Zhufeng; Wang Yunliang; Sun Shuqin.

1994-01-01

Expounding geochemical characteristics of sandstone-type uranium deposits in northern Sichuan, the authors demonstrate the favourable and unfavourable conditions for enrichment of uranium on the basis of element abundances and ratios of U, Th and K measured by the gamma-ray spectroscopy surveying. The differences between uranium-bearing and non-uranium sandstones and between red sandstone (clay stone) and greenish sandstone can be determined by the gamma-ray spectroscopy (measuring U, Th and K) and XRF analysis (measuring As and Ba). Therefore, the prospecting of the sandstone-type uranium deposits in northern Sichuan can be concentrated in a certain range

Investigation of Alaska's uranium potential

International Nuclear Information System (INIS)

Eakins, G.R.

1975-01-01

Of the various geographical regions in Alaska that were examined in an exhaustive literary search for the possibility of uranium--either vein type or sedimentary--six offer encouragement: the Copper River Basin, the alkaline intrusive belt of west-central Alaska and Selawik Basin area, the Seward Peninsula, the Susitna Lowland, the coal-bearing basins of the north flank of the Alaska Range, the Precambrian gneisses of the USGS 1:250,000 Goodnews quadrangle, and Southeastern Alaska, which has the sole operating uranium mine in the state. Other areas that may be favorable for the presence of uranium include the Yukon Flats area, the Cook Inlet Basin, and the Galena Basin

Evolution of ore-bearing material sources of endogenous uranium deposits

International Nuclear Information System (INIS)

Kazansk, V.I.; Laverov, N.P.; Tugarinov, A.I.

1976-01-01

Considered are the regularities of changes in types and conditions of uranium deposit formation in connection with the general development of the earth crust tectonic structures. Out of pre-Kembrian uranium deposits considered are Vitwatersrand conglomerates, hydrothermal deposits in pre-Kembrian iron quartzites in the areas of regional fractures in exocontacts of big multiphase granitoid massifs of Proterozoic age and in the fundament folded structures. The hydrothermal-metamorphogen theory is supported of the origin of uranium-bearing sodium metasomatite of Proterozoic, including uranium deposits in the area of the Atabaska lake. Four genetic classes of Palaeozoic deposits are considered. Four periods are singled out in the development of Palaeozoic uranium provinces. Most of the Palaeozoic deposits are shown to be of polygenous origin. Mesozoic deposits are also polygenous, but the combination of ore substance sources in them is more complex

General science on Cluff discovery: memory of a uranium-bearing system

International Nuclear Information System (INIS)

Dardel, J.

2009-01-01

The author comments the different observations and interpretations made about the geological history and structure of the Athabasca Basin in Canada, and how the different bore holes gave different results in terms of presence of uranium. Findings illustrate the concept of uranium-bearing system which brings together geological factors which locally control the deposit genesis, and essential elements (source, transport, deposit) and chemical processes

Characteristics and significance of uranium bearing pan african younger granite in the eastern desert, Egypt

International Nuclear Information System (INIS)

Hassan, M.A.; Dabbour, G.A.; Mohammden, T.F.

1998-01-01

Surficial uranium mineralization was discovered in four pan african younger granite plutons in the eastern desert of egypt. The present study revealed great similarity between these plutons both in petrography and geochemistry. They are two-feldspar, two-mica peraluminous granites which have been formed by melting of crustal materials and emplaced during the late stage stage of a late proterozoic orogenic cycle. Radiometric and geochemical investigations indicate that these granites are fertile with respect to U and form a potential target for primary uranium deposits. Four models are suggested to explain the source and mechanism of the surficial uranium mineralization in these granites. The most applicable model is the oxidation of U +4 found in minute disseminated uraninite grains and its subsequent mobilization. This is supported by petrographic and autoradiographic studies. The bearings of the present study on further exploration for uranium deposits in granites of the arabian- Nubian shield in general are discussed

Synergetic treatment of uranium-bearing waste water with sulfate reducing bacteria and zero-valent iron

International Nuclear Information System (INIS)

Zhou Quanyu; Tan Kaixuan; Zeng Sheng; Liu Dong

2009-01-01

The treatment of uranium-bearing wastewater from uranium mine and using microorganism to treat wastewater were paid much attention to environmental researchers. Based on column experiments, we investigated the potential using sulfate reducing bacteria (SRB) and zero-valent iron (ZVI) to synergetic treat contamination in wastewater such as sulfate, uranium, etc. SRB+ZVI can effectively remove contamination U(VI) and SO 4 2- in wastewater. The removal rate is 99.4% and 86.2% for U(VI) and SO 4 2- , respectively. The pH of wastewater can be basified to neutral. U(VI) and SO 4 2- as electron acceptor of sulfate reducing bacteria are removed by biological reduction. The corrosion of ZVI is benefit to enhance the pH of wastewater, forms anaerobic reducing environment, strengthens survival and metabolism reaction of SRB, and plays a synergetic enhancement. (authors)

Treatment of uranium-bearing wastewater by vacuum membrane distillation

International Nuclear Information System (INIS)

Duan Xiaolin; Li Qicheng; Chen Bingbing

2006-01-01

The removal of uranium from wastewater was carried out by vacuum membrane distillation (VMD) using microporous polypropylene membrane. The effects of feed temperature, mass concentration of U, flow rate and vacuum-side pressure on permeation flux and rejection were studied. The optimum experimental conditions are as follows: feed flow rate is 0.5 m/s, feed temperature is 55 degree C, vacuum-side pressure is 2.66 kPa. When the mass concentrations of U in the feed solution range from 1 mg/L to 9 mg/L, the membrane flux is 3.5 kg/(m 2 ·h) and the rejection rate is 99.1% under the optimum conditions. The water separated from uranium solution by vacuum membrane distillation could meet the state-controlled discharge standard 0.05 mg/L. The VMD as a novel technology will play an important role in the treatment of uranium-bearing wastewater. (authors)

Geostatistics applied to estimation of uranium bearing ore reserves

International Nuclear Information System (INIS)

Urbina Galan, L.I.

1982-01-01

A computer assisted method for assessing uranium-bearing ore deposit reserves is analyzed. Determinations of quality-thickness, namely quality by thickness calculations of mineralization, were obtained by means of a mathematical method known as the theory of rational variables for each drill-hole layer. Geostatistical results were derived based on a Fortrand computer program on a DEC 20/40 system. (author)

Gamma-spectrometric determination of {sup 232}U in uranium-bearing materials

Energy Technology Data Exchange (ETDEWEB)

Zsigrai, Jozsef [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), 76125 Karlsruhe, P.O. Box 2340 (Germany); Nguyen, Tam Cong [Centre for Energy Research of the Hungarian Academy of Sciences (EK), 1525 Budapest 114, P.O. Box 49 (Hungary); Berlizov, Andrey [European Commission, Joint Research Centre (JRC), Institute for Transuranium Elements (ITU), 76125 Karlsruhe, P.O. Box 2340 (Germany)

2015-09-15

The {sup 232}U content of various uranium-bearing items was measured using low-background gamma spectrometry. The method is independent of the measurement geometry, sample form and chemical composition. Since {sup 232}U is an artificially produced isotope, it carries information about previous irradiation of the material, which is relevant for nuclear forensics, nuclear safeguards and for nuclear reactor operations. A correlation between the {sup 232}U content and {sup 235}U enrichment of the investigated samples has been established, which is consistent with theoretical predictions. It is also shown how the correlation of the mass ratio {sup 232}U/{sup 235}U vs. {sup 235}U content can be used to distinguish materials contaminated with reprocessed uranium from materials made of reprocessed uranium.

Method and apparatus for separating uranium isotopes

International Nuclear Information System (INIS)

Bernstein, E.R.

1977-01-01

A uranium compound in the solid phase (uranium borohydride four) is subjected to radiation of a first predetermined frequency that excites the uranium-235 isotope-bearing molecules but not the uranium-238 isotope-bearing molecules. The compound is simultaneously subjected to radiation of a second predetermined frequency which causes the excited uranium-235 isotope-bearing molecules to chemically decompose but which does not affect the uranium-238 isotope-bearing molecules. Sufficient heat is then applied to the irradiated compound in the solid phase to vaporize the non-decomposed uranium-238 isotope-bearing molecules but not the decomposed uranium-235 isotope-bearing molecules, thereby physically separating the uranium-235 isotope-bearing molecules from the uranium-238 isotope-bearing molecules. The uranium compound sample in the solid phase is deposited or grown in an elongated tube supported within a dewar vessel having a clear optical path tail section surrounded by a coolant. Two sources of radiation are focused on the uranium compound sample. A heating element is attached to the elongated tube to vaporize the irradiated compound

Recovery of uranium from uranium bearing black shale

International Nuclear Information System (INIS)

Das, Amrita; Yadav, Manoj; Singh, Ajay K.

2016-01-01

Black shale is the unconventional resource of uranium. Recovery of uranium from black shale has been carried out by the following steps: i) size reduction, ii) leaching of uranium in the aqueous medium, iii) fluoride ion removal, iv) solvent extraction of uranium from the aqueous leach solution, v) scrubbing of the loaded solvent after extraction to remove impurities as much as possible and vi) stripping of uranium from the loaded organic into the aqueous phase. Leaching of black shale has been carried out in hydrochloric acid. Free acidity of the leach solution has been determined by potentiometric titration method. Removal of fluoride ions has been done using sodium chloride. Solvent extraction has been carried out by both tributyl phosphate and alamine-336 as extractants. Scrubbing has been tried with oxalic acid and sulphuric acid. Stripping with sodium carbonate solution has been carried out. Overall recovery of uranium is 95%. (author)

Investigation of disposal of nitrate-bearing effluent from in-situ leaching process by natural evaporation in Yining uranium mine

International Nuclear Information System (INIS)

Huang Chongyuan; Li Weicai; Zhang Yutai; Gao Xizhen

2000-01-01

Experiments indicated, after lime neutralization and precipitation of nitrate-bearing effluent from in-situ leaching process, uranium concentration increase with the increasing of nitrate concentration. Only when nitrate concentration is <0.5 mg/L, uranium concentration can drop from 1.5-2.0 mg/L to about 1.0 mg/L. The permeability coefficient of soil is about 1.0-1.1 m/d in the place which is scheduled for building natural evaporation pool. After lime neutralization of nitrate-bearing effluent, it can drop to 0.03-0.01 m/d. Setting up water-proof layer in natural evaporation pool can reduce pollution of underground water by uranium, nitrate and ammonium

Geochemical features of the ore-bearing medium in uranium deposits in the Khiagda ore field

Science.gov (United States)

Kochkin, B. T.; Solodov, I. N.; Ganina, N. I.; Rekun, M. L.; Tarasov, N. N.; Shugina, G. A.; Shulik, L. S.

2017-09-01

The Neogene uranium deposits of the Khiagda ore field (KOF) belong to the paleovalley variety of the hydrogene type and differ from other deposits of this genetic type in the geological and geochemical localization conditions. The contemporary hydrogeochemical setting and microbiological composition of ore-bearing medium are discussed. The redox potential of the medium (Eh is as low as-400 mV) is much lower than those established at other hydrogenic deposits, both ancient Late Mesozoic and young Late Alpine, studied with the same methods in Russia, Uzbekistan, and southern Kazakhstan. The pH of subsurface water (6.86-8.13) differs in significant fluctuations both between neighboring deposits and within individual ore lodes. Hydrogen-forming and denitrifying bacteria are predominant in microbiological populations, whereas sulfate-reducing bacteria are low-active. The consideration of these factors allowed us to describe the mechanism of uranium ore conservation as resulting from the development of the cryolithic zone, which isolates ore lodes from the effect of the external medium. Carbonated water supplied from the basement along fault zones also participates in the formation of the present-day hydrogeochemical setting. Based on the features of the ore-bearing medium, we propose a method of borehole in situ acid leaching to increase the efficiency of mining in the Khiagda ore field.

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

Energy Technology Data Exchange (ETDEWEB)

Beiswenger, Toya N. [Pacific Northwest National Laboratory, Richland, WA, USA; Gallagher, Neal B. [Eigenvector Research, Inc., Manson, WA, USA; Myers, Tanya L. [Pacific Northwest National Laboratory, Richland, WA, USA; Szecsody, James E. [Pacific Northwest National Laboratory, Richland, WA, USA; Tonkyn, Russell G. [Pacific Northwest National Laboratory, Richland, WA, USA; Su, Yin-Fong [Pacific Northwest National Laboratory, Richland, WA, USA; Sweet, Lucas E. [Pacific Northwest National Laboratory, Richland, WA, USA; Lewallen, Tricia A. [Pacific Northwest National Laboratory, Richland, WA, USA; Johnson, Timothy J. [Pacific Northwest National Laboratory, Richland, WA, USA

2017-10-24

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, 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

Discussion on prospecting potential for rich uranium deposits in Xiazhuang uranium ore-field, northern Guangdong

International Nuclear Information System (INIS)

Wu Lieqin; Tan Zhengzhong

2004-01-01

Based on analyzing the prospecting potential for uranium deposits in Xiazhuang uranium ore field this paper discusses the prospecting for rich uranium deposits and prospecting potential in the region. Research achievements indicate: that the Xiazhuang ore-field is an ore-concentrated area where uranium has been highly enriched, and possesses good prospecting potential and perspective, becoming one of the most important prospecting areas for locating rich uranium deposits in northern Guangdong; that the 'intersection type', the alkaline metasomatic fractured rock type and the vein-group type uranium deposits are main targets and the prospecting direction for future uranium prospecting in this region

Uranium and thorium abundances in some graphite-bearing precambrian rocks of India and implications

International Nuclear Information System (INIS)

Pandey, U.K.; Krishnamurthy, P.

1995-01-01

Graphite schists from parts of Gujarat in the Aravalli supergroup show maximum contents of uranium (70-95 ppm), hosted mainly in the graphites, whereas such schists from the Tamil Nadu granulite terrain contain distinctly lower amounts of uranium (7-9 ppm). Graphite-bearing hornblende gneiss and calc-granulites from Madurai, Tamil Nadu, contain higher amounts of uranium (12-28 ppm) than the schists, and uranium is mainly hosted by the magnetite and allanite occurring as independent grains with flaky graphite and also as inclusions within quartz. Khondalites from Andhra Pradesh are depleted in uranium (0.9-1.3 ppm) compared to Th (17.5-20.2 ppm). Except for the khondalites, which have high Th/U ratio (13.5-22.4), all the other samples have very low Th/U ratios (0.10-0.80) compared to the crustal average (3-4). Such variations among similar rock types, may in part be related to uranium and thorium abundances inherited from parental rocks, modified later by hydrothermal and/or metasomatic processes. Graphites from such rock types can provide both in situ and migrant reductants for hosting a variety of uranium and other metallic deposits. (author). 12 refs., 1 tab., 1 fig

A mineralogical investigation of a uranium-bearing phosphatic siltstone from Tsongnapan, Northwestern Cape Province

International Nuclear Information System (INIS)

Brynard, H.J.

1980-02-01

A sample of uranium-bearing phosphatic siltstone from Tsongnapan in the Northwestern Cape Province was investigated mineralogically. The siltstone consists of cyclically alternating apatite- and calcite spherulite-rich layers. The calcite content of the rock is 11,4% and the apatite content is 42,1%. The groundmass shows the presence of the following elements: Si, Ca, P, Fe, Mg, K, Al, Cu and Zn. Detrital quartz, albite and magnetite are mainly confined to calcite spherulitic layers. The uranium content of the siltstone is 1 120 ppm U 3 O 8 and the thorium content 638 ppm ThO 2 . Both uranium and thorium occur mainly in the apatite-rich groundmass and to a minor extent in subsidiary monazite and zircon. Laboratory-scale metallurgical tests showed that the uranium is almost wholly leachable by hydrochloric acid while sulphuric and acetic acid dissolve only a small percentage of the uranium with concomitant formation of calcium sulphate. The rock probably formed in a low-energy regime in a marine environment where apatite and calcite spherulites crystallised from a possibly colloidal state [af

U-bearing particles in miners' and millers' lungs

International Nuclear Information System (INIS)

Paschoa, A.S.; Wrenn, M.E.; Singh, N.P.; Miller, S.C.; Jones, K.W.; Cholewa, M.; Hanson, A.L.; Saccomanno, G.

1984-01-01

The size distribution of uranium-bearing particles in air particulates in occupational areas of active uranium mines and mills is largely uninvestigated. Investigation of the size of residual uranium-bearing particles in uranium miners' and millers' lungs is warranted because significant inhalation of uranium can occur in certain occupational areas. Average uranium concentrations of about 0.3 ppM U in uranium miners' and millers' lungs have been reported. Local uranium concentrations in uranium-bearing particles inhaled and regionally deposited in the lungs of uranium miners and millers are orders of magnitude larger than the average uranium concentrations reported. The feasibility of using microPIXE (particle induced x-ray emission) techniques to search for such uranium-bearing particles embedded in lung tissues has been demonstrated. Proton microbeams 20 μm in diameter, scanning in 5 μm steps, were used to irradiate sections of lung tissues 10 to 40 μm thick. The paper will briefly describe the method, and present and discuss the results obtained in an extensive search for uranium-bearing particles embedded in lung tissues, collected at autopsy, of former uranium miners and millers. 13 references, 1 table

Technical application of agglomerated acidic heap leaching of clay-bearing uranium ore in China

International Nuclear Information System (INIS)

Zeng Yijun; Li Jianhua; Li Tieqiu; Zhong Pingru

2002-01-01

The permeability of ore mass has a great influence on the leaching period of heap leaching and the leaching efficiency, hence the uranium ores with high content of clay is difficult to acidic heap leaching. The Research Institute of Uranium Mining has engaged several years studies on the cementing agents of acidic agglomeration, agglomeration conditions, as well as the curing measures of agglomerated balls. On the basis of these studies, several types of clay-bearing ores have been tested with good results. The technique of agglomerated acidic heap leaching has been successfully applied in a uranium mine. Since agglomeration has effectively increased the permeability of ore heap, its leaching period is decreased from 200 days to 60 days, the leaching efficiency is increased to 96% from less than 40% comparing with direct heap leaching program

Application of Taguchi method for separation of uranium from acetate bearing wastewater using hydroxamic acid based sorbent

International Nuclear Information System (INIS)

Satpati, S.K.; Hareendran, K.; Roy, S.B.; Vaidya, A.; Bankar, V.; Dasgupta, K.; Pal, S.

2016-01-01

Separation and recovery of uranium from effluent of nuclear facility has drawn immense attention in separation science research. The acetic acid based uranium solution effluent generated in uranium metal powder production facility was targeted for the study. Solid state separation technique has been employed using hydroxamic acid based chelating sorbent because of several advantages. In the study, the sorbent performances have been evaluated for its important parameters like isotherm, efficiency and kinetics. The equilibrium adsorption capacity (q e ) and distribution coefficient (K d ) of U(VI) have been evaluated as 3.24 mg/g sorbent and 805 ml/g sorbent respectively. Uranium has been recovered using HCl solution. Uranium removal from the feed was found to be more than 95% and the recovery of uranium was more than 99% from the adsorbed phase. Elution process is faster than sorption process. Taguchi optimization method has been applied for designing experimental study and also to identify the optimum operational conditions for uranium separation process.The developed process is useful for separation and recovery of uranium from acetate bearing wastewater generated in uranium processing facilities

A study of geochemical prospecting for uranium-bearing low grade coal beds in Korea

International Nuclear Information System (INIS)

Kim, O.B.

1980-01-01

Trend surface analysis was applied in order to find the criteria for geochemcial prospecting of uranium bearing narrow coal bed in Ogcheon Group. Soil samples were taken from the Mogso-ri area, the Deogpyeong-ri area, and the Jeogum-ri area and were analyzed for U, V, Mo, Pb, Zn, Cu, Cd, and Cr by colorimetry and atomic absorption. All data were processed statistically by HP 3000 computer. The results were as follows: Molybdenium could be used as the best competent indicator element for uranium. Lead, Copper, Vanadium could be used as assistant indicator. The trend surface analysis and the residual map were very useful for statistical interpretation of analyzed data. Second or third degree trend surface analysis was sufficient for this work. The trend map revealed that the origin of uranium in these area was the same. (Author)

Thoughts about uranium-bearing quartz-pebble conglomerates: a summary of ideas presented at the workshop

International Nuclear Information System (INIS)

Skinner, B.J.

1981-01-01

A summation of papers given at the Workshop on the Genesis of Uranium- and Gold-Bearing Precambrian Quartz-Pebble Conglomerates held at Golden, Colorado, on October 13-15, 1975, is presented. Seven pertinent topics, chosen by the author, are compiled from the several papers and are critically discussed. The time of formation of these deposits is between 3- and 2-billion years ago. The uraniferous conglomerates appear to be of fluvial origin and the known uranium reserves are plotted along an idealized fluviatile system. The source areas for the placers are related to 3 billion year old granites, greenstones and metamorphic rocks of the cratons - these most probably were located paleogeographically in a polar region. The role of diagenesis in the formation of uranium ores is discussed with respect to oxygen content of Precambrian atmospheres and of subsurface waters. The effect of subsequent metamorphism and recrystallization upon indigenous pyrites and kerogen is related. Finally characteristics of known uranium deposits are correlated to suggest a strategy to be employed while prospecting for undiscovered uranium ores. (DT)

Potential uranium host rocks and structures in the central Great Plains

International Nuclear Information System (INIS)

Zeller, E.J.; Dreschhoff, G.; Angino, E.; Holdoway, K.; Hakes, W.; Jayaprakash, G.; Crisler, K.; Saunders, D.F.

1975-01-01

A preliminary study was completed of the uranium potential of the Central Great Plains. The study area extends from longitude 99 to 104 0 W and is bounded by the North Platte River on the north and the Canadian River on the south. This region has no known commercial uranium accumulations, but is an area which contains formations with similar facies that are known to have deposits in other areas. A new method of utilizing petroleum exploration gamma-ray well log data was tested in the western Kansas portion of the survey area. Gamma activities in the Dakota and Morrison formations were computer-processed by trend surface analysis, statistically analyzed, and the anomalies were compared with regional geomorphic lineaments derived from satellite imagery as well as regional geology, to draw conclusions as to their origin and significance. Conclusions are: (1) possible uraniferous provinces have been outlined in the subsurface of western Kansas; (2) the new well log data approach can be used to define potential uraniferous provinces in any well-explored petroleum region; (3) the close spatial correlation between anomalies and regional geomorphic lineaments provides strong support for the concept that the lineaments represent vertical fracture zones which can act as preferred pathways for vertical fluid migration; and (4) the location of the strongest anomalies over impervious salt bodies indicates that any uranium bearing mineralizers must have moved down through the geologic section rather than upward. Recommendations are made to extend the application of the well-log approach, to do drilling and sampling to prove whether the anomalies are really due to uranium, and to add geobotanical and emanometric measurements during future studies

Difference of ore-bearing and non-ore-bearing pegmatite in the Guangshigou area and its research significance

International Nuclear Information System (INIS)

Zuo Wenqian; Zhang Zhanshi; Sha Yazhou; Rao Chaojun

2011-01-01

Guangshigou uranium deposit is one of the typical granite-pegmatite uranium deposits in China, the ore-body are located in the density zone of the outside contact zone of granite pluton. To distinguish the ore-bearing and Non-ore-bearing pegmatite is one of the most practices and have great significance for the effect of mineral exploration. Based on the field investigation and former research results, contrast research on the characteristics of the pegmatite on petrology, geophysical, geochemistry and stable isotopes have been carried out. It is pointed out that the ore-bearing pegmatite differ from the non-ore-bearing one from macro-and-micro-view in Guangshigou Uranium deposits, the main characteristics are summarized; the macro-and-micro signs are established, the genetic difference between the ore-bearing and non-ore-bearing pegmatite are discussed primarily. The achievements would be helpful for prospecting and researching of this type uranium deposits in China. (authors)

Dazai super-large uranium-bearing germanium deposit in western Yunnan region metallogenic geological conditions and prospect

International Nuclear Information System (INIS)

Han Yanrong; Yuan Qingbang; Li Yonghua; Zhang Ling; Dai Jiemin

1995-05-01

The Dazai super-large uranium-bearing germanium deposit is located in Bangmai Fault Basin, Western Yunnan, China. The basin basement is migmatitic granite and the cover is miocene coal-bearing clastics, Bangmai Formation. The basin development had undergone faulted rhombus basin forming, synsedimentary structure-developing and up-lifted-denuded stages. Synsedimentary faults had controlled distribution of sedimentary formation and lithofacies, and uranium and germanium mineralization. Germanium ore-bodies occur mainly in master lignite-bed of lower rhythmite. Hosted germanium-lignite is taken as main ore-type. Germanium occurs in vitrinite of lignite in the form of metal-organic complex. The metallogenetic geological conditions of the deposit are that ground preparation is uplift zone-migmatitic granite-fault basin-geothermal anomaly area, rich and thick ore-body is controlled by synsedimentary fault, peat-bog phase is favorable to accumulation for ore-forming elements, and unconformity between overlying cover and underlying basement is a channel-way of mineralizing fluid. A multiperiodic composite, being regarded sedimentation and diagenesis as a major process, uranium and germanium ore deposit has been formed through two mineralization. Four prospecting areas have been forecasted and two deposits have been accordingly discovered again. Technical-economic provableness shows that the deposit is characterized by shallow-buried, rich grade, large scale, easy mining and smelting. (9 figs.)

Potential uranium provinces in some arabian countries

Energy Technology Data Exchange (ETDEWEB)

Salman, A A [Nuclear materials authority, El Maadi, Cairo, (Egypt)

1995-10-01

This work represents an attempt to delineate potential uranium provinces in some Arabian countries using various related recognition criteria. Definition of these provinces is based on the available geologic and tectonic setting beside geochronological sequence and some geochemical characteristics. This trial would be of a great help for interchanging the ideas and necessary data for the development in the fields of uranium exploration and production. As a result of this study, a number of promising potential uranium provinces are recommended in some arabian countries. 5 figs.

Potential uranium provinces in some arabian countries

International Nuclear Information System (INIS)

Salman, A.A.

1995-01-01

This work represents an attempt to delineate potential uranium provinces in some Arabian countries using various related recognition criteria. Definition of these provinces is based on the available geologic and tectonic setting beside geochronological sequence and some geochemical characteristics. This trial would be of a great help for interchanging the ideas and necessary data for the development in the fields of uranium exploration and production. As a result of this study, a number of promising potential uranium provinces are recommended in some arabian countries. 5 figs

A uranium-bearing coalificated wood remain from the Upper Carboniferous uranium ore deposit in the Baden-Baden region of the Black Forest

International Nuclear Information System (INIS)

Kirchheimer, F.

1981-01-01

From the 1973 discovered Upper Carboniferous uranium ore sandstone deposit in the Baden-Baden region (Black Forest) a uranium-bearing coalificated wood remain derived, probably the relic of a Cordaites-trunk. The chemical determinated whole uranium content of this amounts about to 40 wght.-%. Pitchblende of the collomorphic type is embedded in the vitrinite of the fossil and imitates the nearly destroyed former wood-structure. The aggregates of this mineral, surrounded by zones of contact, consist of at least two modifications of different reflectance and hardness. Radiometric analyses reveale a different disturbed radioactive equilibrium, which indicated partly loss and re-enrichment of the uranium-content in recent time. A part of the fossil is completely mineralized by pitchblende of high reflectance and associated galena. For this paragenesis the radiometric investigations proved an approached equilibrium of radioactive substances. Therefore it is to be estimated, that the pitchblende is not alterated substantially, in contrast to the embeddings in the vitrinite, rich in little reflecting and soft nasturanium. The inhomogenic mineralization of the highly coalificated fossil, also to recognise microscopically, is set in relation to the controverse genetic interpretation of the deposit. Final remarks are concerned to other uranium-enriched fossils, especially remains of bones of different origin and age. (orig.) [de

Czechoslovak uranium

International Nuclear Information System (INIS)

Pluskal, O.

1992-01-01

Data and knowledge related to the prospecting, mining, processing and export of uranium ores in Czechoslovakia are presented. In the years between 1945 and January 1, 1991, 98,461.1 t of uranium were extracted. In the period 1965-1990 the uranium industry was subsidized from the state budget to a total of 38.5 billion CSK. The subsidies were put into extraction, investments and geologic prospecting; the latter was at first, ie. till 1960 financed by the former USSR, later on the two parties shared costs on a 1:1 basis. Since 1981 the prospecting has been entirely financed from the Czechoslovak state budget. On Czechoslovak territory uranium has been extracted from deposits which may be classified as vein-type deposits, deposits in uranium-bearing sandstones and deposits connected with weathering processes. The future of mining, however, is almost exclusively being connected with deposits in uranium-bearing sandstones. A brief description and characteristic is given of all uranium deposits on Czechoslovak territory, and the organization of uranium mining in Czechoslovakia is described as is the approach used in the world to evaluate uranium deposits; uranium prices and actual resources are also given. (Z.S.) 3 figs

Maintaining the Uranium Resources Assessment Data System and assessing the 1990 US uranium potential resources

International Nuclear Information System (INIS)

McCammon, R.B.; Finch, W.I.; Grundy, W.D.; Pierson, C.T.

1991-01-01

The Energy Information Administration's (EIA) Uranium Resource Assessment Data System contains information on potential resources (undiscovered) of uranium in the United States. The purpose of this report is: (1) to describe the work carried out to maintain and update the Uranium Resource Assessment Data (URAD) System, (2) to assess the 1990 US uranium potential resources in various cost categories, and (3) to identify problems and to recommend changes that are needed to improve the URAD System. 13 refs., 5 figs., 4 tabs

Uranium potentialities of precambrian from Goias State

International Nuclear Information System (INIS)

Danni, J.C.M.; Marini, O.J.; Faria, A. de; Dardenne, M.A.

1983-01-01

A chrono-stratigraphy synthesis of geological unities from Precambrian, with emphasis on characterization of its depositional region, tectonics and or lithology is presented. The main ideas relating to uranium metallogeny in precambrian ages referring to geologic situation in Goias is described. The uranium occurrence associated to precambrian unities from region and some interpretations for evaluation the potentialities of uranium metallotect are also cited. (C.G.C.)

Approaches to mastering the uranium potential of Cameroon

International Nuclear Information System (INIS)

Chakam Tagheu, P.; Simo, A.

2014-01-01

Uranium deposits are spread over the five continents. According to the International Atomic Energy Agency (IAEA) estimation in 2009, the global reserves of economically recoverable uranium are estimated at 4.5 million tonnes. In 2012, the world production of uranium was about 54,610 tonnes and the main producers were Kazakhstan (36%), Canada (15%) and Australia (12%). Brazil, Russia, China, India productions accounted for 9.4% of the overall world production. Significant deposits also exist in Africa including Cameroon; those currently in mining stage are in Namibia, Malawi, and Niger. Cameroon has significant mineral deposits such as gold, alluvial diamonds, iron, bauxite and uranium. All of them are still in the exploration stage. Although Cameroon has not launched a nuclear power programme, the mining of its uranium resources is considered as an important component of the national economy. Many uranium occurrences have so far been discovered in Cameroon. They include Kitongo, Salaki, Mayo Nielse and Teubang in the Northern region and Ngombas near Lolodorf in the Southern region. The Cameroon Government is engaged in (i) the assessment of the U-ore resource through drilling, and (ii) the airborne geophysical survey of mining potentials areas. The result of these studies may lead to a better estimation of the national uranium potential. This paper aims at pointing out constraints to assess the uranium potential of Cameroon and proposes measures that could improve on the leveraging of exploitation of this mineral. (author)

Maintaining the uranium resources data system and assessing the 1991 US uranium potential resources

Energy Technology Data Exchange (ETDEWEB)

McCammon, R.B. (Geological Survey, Reston, VA (United States)); Finch, W.I.; Grundy, W.D.; Pierson, C.T. (Geological Survey, Denver, CO (United States))

1992-12-31

The Energy Information Administration's (EIA) Uranium Resource Assessment Data (URAD) System contains information on potential resources (undiscovered) of uranium in the United States. The purpose of this report is: (1) to describe the work carried out to maintain and update the URAD system; (2) to assess the 1991 U.S. uranium potential resources in various cost categories; and (3) to describe the progress that has been made to automate the generation of the assessment reports and their subsequent transmittal by diskette.

Petrology, mineralogy and geochemistry of surficial uranium deposits

International Nuclear Information System (INIS)

Pagel, M.

1984-01-01

A comprehensive understanding of the petrology, mineralogy, and geochemistry of surficial uranium ore deposits is important for developing prospecting and evaluation strategies. Carnotite is the main uranium mineral and is found in those deposits that have the greatest potential uranium resources. The following uranium-bearing minerals have been reported to occur in surficial deposits: carnotite, tyuyamunite, soddyite, weeksite, haiweeite, uranophane, betauranophane, metaankoleite, torbernite, autunite, phosphuranylite, schroeckingerite, Pb-V-U hydroxide (unnamed mineral), uraninite and organourano complexes. The interrelationships between some of the minerals of the host rocks (especially the clays) are not well understood. (author)

The sedimentology of uranium-bearing sandstones on the farm Ryst Kuil 351 Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1979-06-01

A study of the sedimentology of some uranium-bearing sandstones on the farm Ryst Kuil 351 was made in order to assess possible relationships between the mineralisation and the sedimentary facies and/or the palaeo-environment. Use was made of 6 vertical profiles, derived from horizontal traverses. 12 sedimentary facies were recognised according to grain-size and sedimentary structure. The transitions between these facies, as derived from the vertical profiles, were subjected to Markov analysis. Only 3 Markov-dependent transitions were derived, but several facies transitions and associations occurred with greater than random frequency. These, together with the vertical profiles, were used to interpret the palaeo-environmental succession. This succession is fluvial meandering and two sub-environments - channel and flood plain - were delineated according to the prevalence of sandstone or mudstone facies. The uranium-bearing sandstones occur in the lower part of a thick (29 - 46m) multistorey point bar sequence within the channel sub-environment. The mineralisation is associated with koffieklip and is restricted to two sedimentary facies - massive very fine-to-finegrained sandstone and horizontally bedded, very fine- to fine-grained sandstone. The mineralisation normally occurs near the bases of the point bars

Recovery of uranium from uranium mine waters and copper ore leaching solutions

Energy Technology Data Exchange (ETDEWEB)

George, D R; Ross, J R [Salt Lake City Metallurgy Research Center, Salt Lake City, UT (United States)

1967-06-15

Waters pumped from uranium mines in New Mexico are processed by ion exchange to recover uranium. Production is approximately 200 lb U{sub 3}O{sub 8}/d from waters containing 5 to 15 ppm U{sub 3}O{sub 8}. Recoveries range from 80 to 90%. Processing plants are described. Uranium has been found in the solutions resulting from the leaching of copper-bearing waste rock at most of the major copper mines in western United States. These solutions, which are processed on a very large scale for recovery of copper, contain 2 to 12 ppm U{sub 3}O{sub 8}. Currently, uranium is not being recovered, but a potential production of up to 6000 lb U{sub 3}O{sub 8}/d is indicated. Ion exchange and solvent extraction research studies are described. (author)

Exploration and uranium mining in Niger

International Nuclear Information System (INIS)

Moussa, M.

2014-01-01

features are important in trapping the mineralisation which is often of roll front type, either reduced consisting in pitchblende and coffinite (Akouta, Arlit, Afasto, Madaouela) or oxidized (Imouraren). The main exploration companies of Uranium in the basin of Tim Mersoï (Northern Iullemenden) are: • AREVA-Niger for the uranium-bearing prospecting permits of Imouraren, Afouday, Agebout; • Cominak for the uranium-bearing prospecting permit Western Afasto; • NorthWestern Mineral Ventures Inc for the uranium-bearing prospecting permits Irhazer and Ingal; • North Atlantic Resources Ltd. for the uranium-bearing prospecting permit Abélajouad; • CNUC for the uranium-bearing permit of Tiguida • Goviex for uranium permit of Madaouéla; • International Uranium Ltd for the uranium-bearing prospecting permits of Agelal I, II, III, IV and Aserka I, II, III, IV; • Total Uranium Corporation for the licences of Chock Negouran I, II, III and IV; • Trend Field Holding SA for the uranium-bearing prospecting permits Tagaza II and IV. (author)

Geochemistry and petrogenesis of the proterozoic granites from Jhabua and Dhar districts, Madhya Pradesh, India and their bearing on uranium mineralisation

International Nuclear Information System (INIS)

Pant, P.C.; Goyal, Navin; Rawal, Neeru

2004-01-01

In the western part of Madhya Pradesh a number of small plutonic granites occur as intrusive into the gneisses and Aravalli metasediments. Granites are of grey, pink colour and gneissic varieties. Mineralogically, the granites are two mica bearing. Chemically they are K 2 O rich, calc-alkaline, metaluminous to peraluminous and differentiated in nature. Tectonically they are volcanic arc types with an affinity to syn-collisional setup. Basement reactivation may be the cause of the emplacement of these granites as the area is traversed by a number of basement lineaments. They are enriched in light REE with Ce/Yb ratio ranging from 1.4 to 8.4. Negative Eu anomaly (Eu/Eu* 0.2 to 0.8) suggests that they are fractionated. High Th/U ratio (1-18) indicates that uranium has been leached out. Hence the overlying infratrappeans hold potential for litho/structural controlled uranium mineralisation.(author)

Uranium exploration status in Bangladesh: Conceptual feasibility studies

International Nuclear Information System (INIS)

Majumder, R.; Khalil, M.; Rashid, M.

2014-01-01

Bangladesh has a nuclear power program of its own and has been trying to setup a nuclear power reactor. For this reason the Bangladesh Atomic Energy Commission (BAEC) is very much interested to get uranium from indigenous sources. Considering the basic need of nuclear minerals and favourable geological setup for nuclear mineral exploration in Bangladesh, BAEC has been operating nuclear mineral exploration program by its limited resource. As Bangladesh is geologically made of solely sedimentary rocks, it is only possibility to mineralize sedimentary types of uranium deposits under favourable reducing environment, which tends to be deposited as commercial uranium ore. Considering the favourable criteria for uranium formation Bangladesh has been divided into 4 zones as the (1) Eastern Mobile Belt (EMB), (2) Stable Platform (SP), (3) Dauki Fault Belt (DFB) and (4) Dinajpur Slope (DS). The occurrence of uranium in Harargaj anticline is the most suitable indication of uranium potentiality in the EMB. The SP is characterized by the occurrences of Gondwana basins in the subsurface. These basins are quite similar to those exist in uranium bearing Gondwana basins of India, South Africa, Brazil, Argentina, Niger, Australia and Madagascar. The DFB is situated close to the Mahadek uranium belt in the southern fringe of Shillong plateau. Recent investigations has shown that number of anomalous radioactive sites have been detected in Jaintiapur, Sreepur and Jadukata river valley of DFB. These results indicate that uranium bearing solution is still flowing in this zone. So, it can be assumed that the solution has been flowing for very long geologic time and ore might have been formed in and around the DFB. The Dinajpur Slope is characterized by Siwalik sediments, which is capable of hosting uranium as found in India and Pakistan. Besides, the gravels beds of alluvial fans have originated from Darjeeling and Sikkim belts, that are two reportedly uranium potential zones of uranium

Non-cyanide process for flotation of a uranium-bearing lead-zinc polymetallic sulphide ore

International Nuclear Information System (INIS)

Li Qingxin

1988-01-01

The characteristics of the minerals of a urnium-bearing lead-zinc ore are described in this paper, And the experimentsl results of non-cyanide flotation process are given. The tests show that the selective flotation process of lead and zinc followed by uranium treatment is feasible in technology and reasonable in economics. When the run-of-mine contains 2.86%Pb, 2.47%Zn and 0,019%U, the lead concentrate containing 65.13%Pb, and 4.51%Zn, the zinc concentrate containing 52.00%Zn and 1.22%Pb, and the uranium concentrate containing 0.028%U can be obtained with the recoveries of 94.87%Pb, 87.61%Zn and 66.13%U respectively. The influence of sodium sulphite on flotaion process, the effect of sodium sulphite and the flotation mechanism of dibutyldithiophosphate ammonium are also discussed

Potential health hazard of nuclear fuel waste and uranium ore

International Nuclear Information System (INIS)

Mehta, K.; Sherman, G.R.; King, S.G.

1991-06-01

The variation of the radioactivity of nuclear fuel waste (used fuel and fuel reprocessing waste) with time, and the potential health hazard (or inherent radiotoxicity) resulting from its ingestion are estimated for CANDU (Canada Deuterium Uranium) natural-uranium reactors. Four groups of radionuclides in the nuclear fuel waste are considered: actinides, fission products, activation products of zircaloy, and activation products of fuel impurities. Contributions from each of these groups to the radioactivity and to the potential health hazard are compared and discussed. The potential health hazard resulting from used fuel is then compared with that of uranium ore, mine tailings and refined uranium (fresh fuel) on the basis of equivalent amounts of uranium. The computer code HAZARD, specifically developed for these computations, is described

Experience with restoration of ore-bearing aquifers after in situ leach uranium mining

International Nuclear Information System (INIS)

Yazikov, V.G.; Zabaznov, V.U.

2002-01-01

In many cases the most important environmental issue for in situ leach uranium mining technology is the impact on groundwater. Usually the greatest issue is the chemical condition of the ore bearing aquifer following the completion of leaching. Based on experience gained during post leach monitoring, it has been found that in properly selected sites the impact following leaching is greatly reduced because of the process of self restoration, otherwise known as natural attenuation. This paper provides ground water monitoring data from 1985 to 1997 following completion of leaching at the Irkol uranium deposit, Kazakhstan. It shows the evolution of the pH, and other chemical parameters over this period. The monitoring results demonstrate that at this site the process of natural attenuation appears to have effectively reduced the impact on groundwater at the site, as well as to keep contaminated leaching fluids from moving more than a few hundreds of metres from the wellfield. (author)

The sedimentology of uranium-bearing sandstones on the farm Riet Kuil 307, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1980-10-01

The sedimentology of four sandstones was studied in outcrop and in the subsurface on the farm Riet Kuil 307, near Beaufort West. Only two of these sandstones are mineralised. These are four surface and two subsurface uranium anomalies and one surface uranium anomaly. The sedimentological study was made by means of 47 vertical profiles measured across and adjacent to the surface anomalies as well as 11 core-logs, which intersected the subsurface anomalies. The unmineralised sandstones are included in this study. A total of 19 sedimentary facies was recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structure. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation is almost entirely confined to the coarser-grained sedimentary facies, which probably acted as suitable aquifers for the transport of uraniferous solutions prior to the precipitation of the uranium. Horizontally bedded sandstone facies comprises 60 per cent of the total cumulative thickness of mineralisation. The nature of the bedding of this facies may have provided a more effective permeability zone for the transport of uraniferous solutions. This facies contains an abundance of carbonaceous material which acted as an important indirect reductant for the precipitation of uranium from solution. The direct reductant was most probably H 2 S produced by enaerobic bacteria acting on this carbonaceous material shortly after deposition of the sediments. Carbonaceous material also occurs in the other mineralised facies and is considered to be the major control on the mineralisation in the uranium-bearing sandstones

Depositional environments of the uranium bearing Cutler Formations, Lisbon Valley, Utah

International Nuclear Information System (INIS)

Campbell, J.A.; Steele-Mallory, B.A.

1979-01-01

The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67 0 W. on the average, whereas marine currents moved sediment S. 36 0 E. and N. 24 0 W., and wind transported sand S. 80 0 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little

Depositional environments of the uranium-bearing Cutler Formations, Lisbon Valley, Utah

Science.gov (United States)

Campbell, John A.; Steele-Mallory, Brenda A.

1979-01-01

The Cutler Formation in Lisbon Valley, San Juan County, Utah, is composed predominantly of fluvial arkosic sandstones, siltstones, shales, and mudstones that were deposited by meandering streams that flowed across a flood plain and tidal flat close to sea level. Two types of channel deposits are recognized from their sedimentary structures: meandering and distributary. The flood plain was occasionally transgressed by a shallow sea from the west, resulting in the deposition of several thin limestones and marine sandstones. The marine sandstones were deposited as longshore bars. Wind transported sand along the shoreline of the shallow sea, forming a coastal dune field. Marine sandstones and eolian sandstones are more common in the upper Cutler in the southern part of the area, whereas in the central and northern part of the area the formation is predominantly fluvial. Crossbed orientation indicates that Cutler streams flowed S. 67? W. on the the average, whereas marine currents moved sediment S. 36? E. and N. 24? W., and wind transported sand S. 800 E. The uranium in the Cutler is found in the central and northern part of the area, in the upper part of the formation, in small fluvial sandstone bodies that were deposited predominantly in a distributary environment. No uranium is known in the marine or eolian sandstones. Petrographically, the uranium-bearing sandstones are identical to other Cutler fluvial sandstones except that they contain less calcite and more clay and are slightly coarser grained. Ore formation has modified the host sandstones very little.

Uranium and REE potential of the albitite-pyroxenite-microclinite belt of Rajasthan, India

International Nuclear Information System (INIS)

Singh, Govind; Sharma, D.K.; Yadav, O.P.; Jain, Rajan B.; Singh, Rajendra

1998-01-01

A number of radioactive albitite, pyroxenite and microclinite occurrences have been identified in north and central Rajasthan, along or in close proximity to major lineaments, from Dancholi - Mewara in the NE to Tal in the SW. With these new findings the total extent of Albitite belt of Rajasthan now stands at over 320 km. These occurrences have been evaluated on the basis of their U, Th and REE content to identify the potential areas for the second phase of uranium exploration programme. Further, based on the various characteristic features of radioactive host rocks, the Albitite Belt has been divided into five sectors. The U 3 O 8 content of albitites varies from 0.008 to 0.44% and of pyroxenites from 0.022 to 2.0% whereas ThO 2 varies from < 0.005 to 0.83% in albitites and <0.005 to 0.033% in pyroxenities. These albitites, microclinites and pyroxenites are also characterised by anomalous concentration of REEs. Uranium and REE bearing phases are represented by uraninite, brannerite, davidite, fergusonite, monazite, anatase, rutile, zircon, allanite and britholite. The data accrued so far suggest that U and REE potential of the Mewara-Maonda and Hurra Ki Dhani-Rohil sectors are very high and hence needs further detailed integrated exploration. (author)

Oxidation kinetics of hydride-bearing uranium metal corrosion products

International Nuclear Information System (INIS)

Totemeier, T.C.; Pahl, R.G.; Frank, S.M.

1998-01-01

The oxidation behavior of hydride-bearing uranium metal corrosion products from zero power physics reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2 , Ar-9%O 2 , and Ar-20%O 2 . Ignition of corrosion product samples from two moderately corroded plates was observed between 125 C and 150 C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride. (orig.)

Effects of potential once-through improvements on the uranium utilization in the closed LWR cycle assuming self generated recycling of uranium and plutonium

International Nuclear Information System (INIS)

1979-06-01

This paper is concerned with potential improvements to the resource utilization of current generation light water reactors operating on a closed U/Pu fuel cycle. Only those modifications to existing systems layout and fuel cycle practise are discussed that have been considered in Working Group 8 A for the once-through cycle. The objective is to give an impression how much the difference in resource utilization between the once-through and the closed U/Pu cycle were changed if both cycles were reoptimized independantly from each other with respect to uranium consumption. No commercial recycling of U/Pu has been taken place to date in 1300 MWe light water reactors. The feasibility of thermal recycling has been demonstrated however on an industrial scale in reactors of the 300 MWe class. (Obrigheim, Gundremmingen). From this experience and from extensive design calculations it has been concluded that for Pu bearing fuel assemblies of 1300 MWe plants it would be favorable to use the same structural layout and similar fuel management procedures as for uranium assemblies. This would result in plant life-time averaged uranium savings on the order of 35 - 40 % relative to the once-through cycle in case of the Self Generated Recycling Mode

Possible uranium sources of Streltsovsky uranium ore field

International Nuclear Information System (INIS)

Zhang Lisheng

2005-01-01

The uranium deposit of the Late Jurassic Streltsovaky caldera in Transbaikalia of Russia is the largest uranium field associated with volcanics in the world, its uranium reserves are 280 000 t U, and it is the largest uranium resources in Russia. About one third of the caldera stratigraphic pile consists of strongly-altered rhyolites. Uranium resources of the Streltsovsky caldera are much larger than any other volcanic-related uranium districts in the world. Besides, the efficiency of hydrothermal alteration, uranium resources appear to result from the juxtaposition of two major uranium sources; highly fractionated peralkaline rhyolites of Jurassic age in the caldera, and U-rich subalkaline granites of Variscan age in the basement in which the major uranium-bearing accessory minerals were metamict at the time of the hydrothermal ore formation. (authors)

Maintaining the uranium resources data system and assessing the 1991 US uranium potential resources. Final report

Energy Technology Data Exchange (ETDEWEB)

McCammon, R.B. [Geological Survey, Reston, VA (United States); Finch, W.I.; Grundy, W.D.; Pierson, C.T. [Geological Survey, Denver, CO (United States)

1992-12-31

The Energy Information Administration`s (EIA) Uranium Resource Assessment Data (URAD) System contains information on potential resources (undiscovered) of uranium in the United States. The purpose of this report is: (1) to describe the work carried out to maintain and update the URAD system; (2)to assess the 1991 U.S. uranium potential resources in various cost categories; and (3) to describe the progress that has been made to automate the generation of the assessment reports and their subsequent transmittal by diskette.

Meso-Cenozoic tectonic evolution and uranium potential evaluations of basins in Beishan-Gansu corridor region

International Nuclear Information System (INIS)

Guo Qingyin; Chen Zuyi; Liu Hongxu; Yu Jinshui

2006-01-01

Beishan-Gansu Corridor region is located at the intersection of the plates of Tarim, North China, Kazakhstan, Siberia and Qaidam. During the Meso-Cenozoic, the region experienced movements of Indo-sinian, Yanshanian, Sichuanian, North China, Himalayan and Neotectonic, and over 20 medium-small size superimposed continental basins were formed. On the basis of analyzing the tectonic stress field, sediment-filling and structure-deformation; the general trending of tectonic evolution in the Meso-Cenozoic is summarized as three-time compressional uplifting and two-time extensional down-faulting. The different evolution of basins under the above mentioned setting can be divided into six stages according to characteristics of filled sediment. The sand bodies developed in down-faulted basins are favorable for uranium ore-formation as they are formed under humid paleoclimates, and rich in reducing matter. Therefore, the Lower-Middle Jurassic is selected as the main target horizon for sandstone-hosted uranium deposit, and the Lower Cretaceous as the minor one. Although the tectonic reactivation of the target horizon after its deposition was generally strong, the slopes formed in some basins could be favorable for the infiltration of uranium-and oxygen-bearing groundwater into sand bodies and form uranium deposits. According to the favorable sand bodies and tectonic reactivation, the northern parts of Chaoshui and Bayingobi basins are regarded as potential regions which are worthy of further exploration. (authors)

Distribution of uranium-bearing phases in soils from Fernald

International Nuclear Information System (INIS)

Buck, E.C.; Brown, N.R.; Dietz, N.L.

1993-01-01

Electron beam techniques have been used to characterize uranium-contaminated soils and the Fernald Site, Ohio. Uranium particulates have been deposited on the soil through chemical spills and from the operation of an incinerator plant on the site. The major uranium phases have been identified by electron microscopy as uraninite, autunite, and uranium phosphite [U(PO 3 ) 4 ]. Some of the uranium has undergone weathering resulting in the redistribution of uranium within the soil

Purification and concentration of uranium-bearing solutions at the plants of the Societe industrielle des minerais de l'Ouest

International Nuclear Information System (INIS)

Vollerin, G.

1980-01-01

The author describes the various processes for purification of uranium-bearing solutions used at the plants of the Societe industrielle des minerais de l'Ouest (SIMO) from their commissioning up to the present time, together with the purification circuit adopted at the two plants at present operating in Niger. (author)

Some potential strategies for the treatment of waste uranium metal and uranium alloys

International Nuclear Information System (INIS)

Burns, C.J.; Frankcom, T.M.; Gordon, P.L.; Sauer, N.N.

1993-01-01

Large quantities of uranium metal chips and turnings stored throughout the DOE Complex represent a potential hazard, due to the reactivity of this material toward air and water. Methods are being sought to mitigate this by conversion of the metal, via room temperature solutions routes, to a more inert oxide form. In addition, the recycling of uranium and concomitant recovery of alloying metals is a desirable goal. The emphasis of the authors' research is to explore a variety of oxidation and reduction pathways for uranium and its compounds, and to investigate how these reactions might be applied to the treatment of bulk wastes

Forecasting sandstone uranium deposits in oil-and-gas bearing basins

International Nuclear Information System (INIS)

Pechenkin, I.

2014-01-01

The interrelation between oxidation and reduction processes in the carbonaceous strata of Paleogene age was first studied in the 1950s in deposit of the Fergana depression. The presence of pre-ore and post-ore epigenesis of petroleum series was established. Part of uranium mineralization was found to be covered with fluid oil. In the middle of the 1960s in the Sabirsay deposit (Uzbekistan) in primary red-coloured continental sediment of Cretaceous age were studied pre-ore reduction changes, which caused economic uranium mineralization in contrasting geochemical barrier. Further research showed that multidirectional epigenetic processes had changed repeatedly. Later, in the 1970s, American geologists studying uranium deposits in the oil-and-gas bearing Texas Plain reached similar conclusions. From their point of view, in the Benevides deposit the main zones of mineralization tend to be located near the boundary where the zones of oxidation in the strata wedge in, developing in epigenetically reduced formations. A second post-mineral reduction was registered in a number of rock bodies. The complexity of the processes is determined by the double role of hydrocarbon fluids and the products of their dissolution. On the one hand, bituminization of permeable strata as well as pyritization, chloritization, dolomitization and other alterations associated with it create favourable geochemical conditions of a reducing character for a subsequent concentration of ore and nonmetal raw materials. On the other hand, intrusion of bitumen and its dissolution in the aeration zone leads to the burial of the mineralization which formed earlier and disappearance of all traces of its formation (epigenetic oxidation zoning). Thus forecasting and subsequent prospecting become impeded. The established sequence of epigenetic alterations allows us to carry out specialized mapping in productive regions, uncovering hidden parts of epigenetic oxidation zoning and “buried” mineralization

The sedimentology of uranium-bearing sandstones on the farm Kaffersfontein 328, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1979-10-01

The sedimentology of uranium-bearing sandstones on the farm Kaffersfontein 328 was studied by use of 23 vertical profiles measured across and adjacent to 3 mineralised deposits. The profiles consist of 18 field sections and 5 borehole logs. The vertical profiles basically consist of a succession of sedimentary facies. A total of 18 facies were recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structures. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation coincides with areas of thicker sandstone, usually where channel over-deepening has taken place. It always occurs above the base of a channel, which often marks the base of the fluvial sandstone sequence. Irregularities in the base of the channel probably caused interruptions to the flow of uraniferous solutions and allowed sufficient time for the precipitation of the uranium. Carbonaceous debris is always associated with the mineralisation and most likely acted as an indirect reductant for the precipitation of uranium from solution. The direct reductant was most probably H 2 S produced by anaerobic bacteria acting on the carbonaceous debris. The mineralisation is confined to the coarser-grained sedimentary facies, which suggests that permeability was an important control on the mineralisation. These facies probably acted as suitable aquifers for the transport of uraniferous solutions. Horizontally bedded sandstone facies comprises 41 per cent of the total cumulative thickness of mineralisation. This facies represents a higher stream power and may consequently contain more carbonaceous material derived from plants, which were eroded from upstream areas. The nature of the bedding may also have provided a more effective permeability zone for the transport of uraniferous solutions prior to precipitation of the uranium

Uranium metallogenic features and prospecting potentialities in the areas around Shabazi uranium deposit in Nanling metallogenic belt

International Nuclear Information System (INIS)

Yang Shanghai

2008-01-01

Based on the actuality of exploration and research on Shabazi uranium deposit in Nanling metallogenic belt, the author analyzes and summarizes uranium metallogenic features of the deposit. Under the direction of modern metallogenic theories of uranium deposit, such as deep-source mineralization and deep prospecting for uranium deposits, it is shown that there is great mineralization and prospecting potentiality in the areas around Shabazi uranium deposit and high attention importance should be paid to the areas in the future exploration according to the synthetical analysis on geologic background of the deposit, uranium mineralization features, ore-controlling factors and systematic data of geology. (authors)

The potential for an Australian uranium industry

International Nuclear Information System (INIS)

Silver, J.M.

1982-06-01

The production of uranium and its part upgrading to enriched uranium for export could be equivalent to 20-25 per cent of Australia's future export income from coal. Australia could be supplying 15,000 tonnes U/yr. and enrichment services of 2.5 million SWU/yr. by 2000. The principles of nuclear energy, nuclear power reactors and the nuclear fuel cycle are described and the relationship between nuclear power and the requirements for uranium and the other steps in the fuel cycle is discussed. Estimates are given of the future world supply-demand balance for each step in the fuel cycle. A survey is made of world uranium resources and fuel cycle upgrading facilities. The costs of production and pricing are assessed in relation to the potential for an Australian industry. Comments are made on the possibility that Australia could provide the repository for both low-level radioactive waste from small countries and the bulk of the world's high level waste. The impact of a uranium industry on the Australian economy is discussed

Oxidation kinetics of hydride-bearing uranium metal corrosion products

Science.gov (United States)

Totemeier, Terry C.; Pahl, Robert G.; Frank, Steven M.

The oxidation behavior of hydride-bearing uranium metal corrosion products from Zero Power Physics Reactor (ZPPR) fuel plates was studied using thermo-gravimetric analysis (TGA) in environments of Ar-4%O 2, Ar-9%O 2, and Ar-20%O 2. Ignition of corrosion product samples from two moderately corroded plates was observed between 125°C and 150°C in all environments. The rate of oxidation above the ignition temperature was found to be dependent only on the net flow rate of oxygen in the reacting gas. Due to the higher net oxygen flow rate, burning rates increased with increasing oxygen concentration. Oxidation rates below the ignition temperature were much slower and decreased with increasing test time. The hydride contents of the TGA samples from the two moderately corroded plates, determined from the total weight gain achieved during burning, were 47-61 wt% and 29-39 wt%. Samples from a lightly corroded plate were not reactive; X-ray diffraction (XRD) confirmed that they contained little hydride.

Uranium-bearing breccia pipes of northwestern Arizona - an overview

International Nuclear Information System (INIS)

Chenoweth, W.L.

1986-01-01

During the 1950s and 1960s, the uranium deposits in breccia pipes of the Grand Canyon region were regarded as geologic curiosities. Today this area is the site of numerous exploration projects for ore-bearing pipes. The classic example of the older mines is the Orphan Lode, a patented claim within Grand Canyon National Park. Between 1956 and 1969, this deposit produced 4.26 million lb U 3 O 8 . Exploration since the mid-1970s has developed numerous new deposits in the Grand Canyon region. The Hack 1, 2, and 3, Pigeon, Kanab North, Canyon, and Pinenut deposits are, or will be, mined. The pipes are circular and originated by dissolution of the Mississippian Redwall Limestone and collapse of the overlying strata. Uraninite ore occurs in both the pipe fill and in association with the peripheral shear zone. The principal host rocks are the Coconino Sandstone, Hermit Shale, and Esplanade Sandstone. Although small (3 to 5 million lb U 3 O 8 ), the high grade (60 to 70% U 3 O 8 ) of the deposits makes the pipes attractive exploration targets

Automated controlled-potential coulometric determination of uranium

International Nuclear Information System (INIS)

Knight, C.H.; Clegg, D.E.; Wright, K.D.; Cassidy, R.M.

1982-06-01

A controlled-potential coulometer has been automated in our laboratory for routine determination of uranium in solution. The CRNL-designed automated system controls degassing, prereduction, and reduction of the sample. The final result is displayed on a digital coulometer readout. Manual and automated modes of operation are compared to show the precision and accuracy of the automated system. Results are also shown for the coulometric titration of typical uranium-aluminum alloy samples

The solubility of thorium and uranium from respirable monazite bearing dust in simulated lung and gut fluids

International Nuclear Information System (INIS)

Twining, J.; McGlinn, P.; Hart, K.

1993-01-01

The accurate assessment of the radiological dose to workers in the mineral sands industry requires information on the human bio-availability of thorium and uranium from monazite bearing respirable dust. The results of a short-term test to determine some of the solubility characteristics of these radionuclides are presented, together with a discussion on the optimum methods which may be applied to longer term studies. The solubility of thorium and uranium were found to be generally less than that of the parent monazite bearing dust in simulated lung and gut fluids over the one month extraction period. In particular, thorium was up to two orders of magnitude less soluble than its host mineral matrix. Assuming that the conservative nature of these radioactive constituents can be extrapolated to longer term exposures, these results imply that radiological dose estimates to the lung should be increased. Solubility of both elements was proportional to particle size. An exponential increase in solubility with decreasing diameter was observed, which implies a time variable solubility. There was also some indication of preferential solubility of radium progeny in both decay series. These factors may have to be accounted for in model estimates of committed dose. 16 refs., 4 tabs., 2 figs

Uranium Enrichment, an overview

International Nuclear Information System (INIS)

Coates, J.H.

1994-01-01

This general presentation on uranium enrichment will be followed by lectures on more specific topics including descriptions of enrichment processes and assessments of the prevailing commercial and industrial situations. I shall therefore avoid as much as possible duplications with these other lectures, and rather dwell on: some theoretical aspects of enrichment in general, underlying the differences between statistical and selective processes, a review and comparison between enrichment processes, remarks of general order regarding applications, the proliferation potential of enrichment. It is noteworthy that enrichment: may occur twice in the LWR fuel cycle: first by enriching natural uranium, second by reenriching uranium recovered from reprocessing, must meet LWR requirements, and in particular higher assays required by high burn up fuel elements, bears on the structure of the entire front part of the fuel cycle, namely in the conversion/reconversion steps only involving UF 6 for the moment. (author). tabs., figs., 4 refs

The computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in Northern Xinjiang, China

Energy Technology Data Exchange (ETDEWEB)

Zhengbang, Wang; Mingkuan, Qin; Ruiquan, Zhao; Shenghuang, Tang [Beijing Research Inst. of Uranium Geology, CNNC (China); Baoqun, Wang; Shuangxing, Lin [Geo-prospecting Team No. 216, CNNC (China)

2001-08-01

The process of establishment of the model includes following steps: (1) Systematically studying a known typical in-situ leachable sandstone type uranium deposit--Deposit No. 512 in Yili basin, analyzing its controlling factors and establishing its metallogenetic model; (2) Establishing the metallogenetic models of this type of uranium deposit and uranium-bearing area on the basis of comparison study on the deposit No. 512 with the same type uranium deposits in the world; (3) Creating the computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in northern Xinjiang; (4) Determining the standards of giving a evaluation-mark for each controlling factor of in-situ leachable sandstone type uranium deposit and uranium-bearing area; (5) Evaluating uranium potential and prospect of the unknown objective target.

The computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in Northern Xinjiang, China

International Nuclear Information System (INIS)

Wang Zhengbang; Qin Mingkuan; Zhao Ruiquan; Tang Shenghuang; Wang Baoqun; Lin Shuangxing

2001-01-01

The process of establishment of the model includes following steps: (1) Systematically studying a known typical in-situ leachable sandstone type uranium deposit--Deposit No. 512 in Yili basin, analyzing its controlling factors and establishing its metallogenetic model; (2) Establishing the metallogenetic models of this type of uranium deposit and uranium-bearing area on the basis of comparison study on the deposit No. 512 with the same type uranium deposits in the world; (3) Creating the computerized semi-quantitative comprehensive identification-evaluation model for the large-sized in-situ leachable sandstone type uranium deposits in northern Xinjiang; (4) Determining the standards of giving a evaluation-mark for each controlling factor of in-situ leachable sandstone type uranium deposit and uranium-bearing area; (5) Evaluating uranium potential and prospect of the unknown objective target

Geological characteristics and prospecting potential of sandstone-type uranium deposits in the north margin of Qaidam basin

International Nuclear Information System (INIS)

Liu Lin; Song Xiansheng; Feng Wei

2012-01-01

The north margin of Qaidam Basin is composed with rift trough and Oulongbuluke landmass which is clamped by Qilian Mountain and Qaidam block Suture zone. The two activities provide a rich source of uranium for the basin area. The coal-bearing rocks as stratums of medium and lower Jurassic, is the main exploration target zones of sandstone-type uranium ore. Through geological survey and drilling, we think that the interlayer oxidation zone. being primary factors of sandstone-type uranium, can be divided into ancient type and modern type. The ancient interlayer oxidation zone type uranium deposit is the main prospecting types in the north margin of Qaidam Basin. Combined with analysis on geological conditions of sandstone-type uranium mineralization, we propose that eastern edge of Yuqia, southern edge of Lucao Mountain, Beidatan and northwest edge of Ulan depression are good prospects. (authors)

Investigation of Witwatersrand uranium-bearing quartz-pebble conglomerates in 1944-1945

International Nuclear Information System (INIS)

Bourret, W.

1981-01-01

The paper discusses the results-both short- and long-term of a 1944 study undertaken by a team from the Manhattan Project (supported by the governments of Great Britain and Canada) to assess the potential for uranium occurrence in the Witwatersrand mining region of South Africa. Details are given on the methods used by the Manhattan team and the results of the sampling study and survey that the team conducted in South Africa. The findings for 23 mines that were surveyed in the Witwatersrand are documented. These mines were the major producing mines in the Witwatersrand region. The prior research that led the Manhattan Project administrators to concentrate efforts on the Witwatersrand is described. The history of uranium production in the Rand since the 1944 study is delineated. Tables show the findings of the sampling study in terms of various major mines. A graph is included to show the growth of uranium production in the Witwatersrand from the initiation of the first operation in 1952 to 1975

Analysis on hydrogeological conditions of uranium formation in mulaamite sag in Kumux basin

International Nuclear Information System (INIS)

Wang Chengwei; Chen Liyun; Wang Juntang

2008-01-01

Based on the comprehensive analysis on the materials, hydrogeological conditions, features of water-bearing rock formation, relationship amoung the hydrogeochemical features and interlayer oxidation zone and uranium formation are analyzed from the point of view of basic geological conditions, it is preliminarily considered that Kuluketage fore-mountain zone has a good potential to develop the interlayer oxidation belt and uranium mineralization. (authors)

Impact of the uranium (VI) speciation in mineralised urines on its extraction by calix[6]arene bearing hydroxamic groups used in chromatography columns.

Science.gov (United States)

Baghdadi, S; Bouvier-Capely, C; Ritt, A; Peroux, A; Fevrier, L; Rebiere, F; Agarande, M; Cote, G

2015-11-01

Actinides determination in urine samples is part of the analyses performed to monitor internal contamination in case of an accident or a terrorist attack involving nuclear matter. Mineralisation is the first step of any of these analyses. It aims at reducing the sample volume and at destroying all organic compounds present. The mineralisation protocol is usually based on a wet ashing step, followed by actinides co-precipitation and a furnace ashing step, before redissolution and the quantification of the actinides by the appropriate techniques. Amongst the existing methods to perform the actinides co-precipitation, alkali-earth (typically calcium) precipitation is widely used. In the present work, the extraction of uranium(VI), plutonium(IV) and americium(III) from the redissolution solutions (called "mineralised urines") on calix[6]arene columns bearing hydroxamic groups was investigated as such an extraction is a necessary step before their determination by ICP-MS or alpha spectrometry. Difficulties were encountered in the transfer of uranium(VI) from raw to mineralised urines, with yield of transfer ranging between 0% and 85%, compared to about 90% for Pu and Am, depending on the starting raw urines. To understand the origin of such a difficulty, the speciation of uranium (VI) in mineralised urines was investigated by computer simulation using the MEDUSA software and the associated HYDRA database, compiled with recently published data. These calculations showed that the presence of phosphates in the "mineralised urines" leads to the formation of strong uranyl-phosphate complexes (such as UO2HPO4) which compete with the uranium (VI) extraction by the calix[6]arene bearing hydroxamic groups. The extraction constant of uranium (VI) by calix[6]arene bearing hydroxamic groups was determined in a 0.04 mol L(-1) sodium nitrate solution (logK=4.86±0.03) and implemented in an extraction model taking into account the speciation in the aqueous phase. This model allowed to

A study on the forms of existence of germanium in uranium-bearing coals of Bangmai basin of Yunnan

International Nuclear Information System (INIS)

Zhang Shuling; Wang Shuying; Yin Jinshuang

1988-07-01

The Bangmai basin is an asymmetrical intermontane synclinal basin with a Hercynian-Yenshan granitic body (γ 3 3 -γ 5 2 ) as its basement. Its overlying strata are made up of the N 1 of coal-bearing clastic rocks of Neogene period. Germanium ore mostly occur within the N 1 2 coal-seam. Uranium, germanium-bearing coals are mainly lignites of low grade in coalation and belong to semidurain, semiclarain, duroclarain and clarodurain. In order to probe into the forms of existence of germanium in coal, six kinds of analytical methods (electronic probe analysis, separation of heavy liquid, grain-size analysis, electric osmosis, chemical extraction and grade-extraction) have been adopted. A simulated test of humic complex germanium in the laboratory was carried out. According to infrared spectral analysis, it is found that 1700 cm -1 wavecrest almost disappears, 1250 cm -1 peak weakens and 1600 cm -1 peak strengthens, 1400 cm -1 peak slightly strengthens. No doubt, these illustrate the formatiion of humic germanium complex. Afterward, through differential thermal analysis and measurement of pH variation of media, it futher proves the presence of humic germanium complex. It is considered that the forms of existence of germanium in uranium-bearing coals mainly are: (1) In close chemical combination with organic matter, usually in the form of humic germanium complex and germanium organic compound; (2) In the state of adsorption, germanium is adsorbed by some organic matter, clay minerals and limonite etc.; (3) A very rare part occurring as isomorphous form

The potential for criticality following disposal of uranium at low-level waste facilities: Uranium blended with soil

Energy Technology Data Exchange (ETDEWEB)

Toran, L.E.; Hopper, C.M.; Naney, M.T. [and others

1997-06-01

The purpose of this study was to evaluate whether or not fissile uranium in low-level-waste (LLW) facilities can be concentrated by hydrogeochemical processes to permit nuclear criticality. A team of experts in hydrology, geology, geochemistry, soil chemistry, and criticality safety was formed to develop achievable scenarios for hydrogeochemical increases in concentration of special nuclear material (SNM), and to use these scenarios to aid in evaluating the potential for nuclear criticality. The team`s approach was to perform simultaneous hydrogeochemical and nuclear criticality studies to (1) identify some achievable scenarios for uranium migration and concentration increase at LLW disposal facilities, (2) model groundwater transport and subsequent concentration increase via sorption or precipitation of uranium, and (3) evaluate the potential for nuclear criticality resulting from potential increases in uranium concentration over disposal limits. The analysis of SNM was restricted to {sup 235}U in the present scope of work. The outcome of the work indicates that criticality is possible given established regulatory limits on SNM disposal. However, a review based on actual disposal records of an existing site operation indicates that the potential for criticality is not a concern under current burial practices.

The potential for criticality following disposal of uranium at low-level waste facilities: Uranium blended with soil

International Nuclear Information System (INIS)

Toran, L.E.; Hopper, C.M.; Naney, M.T.

1997-06-01

The purpose of this study was to evaluate whether or not fissile uranium in low-level-waste (LLW) facilities can be concentrated by hydrogeochemical processes to permit nuclear criticality. A team of experts in hydrology, geology, geochemistry, soil chemistry, and criticality safety was formed to develop achievable scenarios for hydrogeochemical increases in concentration of special nuclear material (SNM), and to use these scenarios to aid in evaluating the potential for nuclear criticality. The team's approach was to perform simultaneous hydrogeochemical and nuclear criticality studies to (1) identify some achievable scenarios for uranium migration and concentration increase at LLW disposal facilities, (2) model groundwater transport and subsequent concentration increase via sorption or precipitation of uranium, and (3) evaluate the potential for nuclear criticality resulting from potential increases in uranium concentration over disposal limits. The analysis of SNM was restricted to 235 U in the present scope of work. The outcome of the work indicates that criticality is possible given established regulatory limits on SNM disposal. However, a review based on actual disposal records of an existing site operation indicates that the potential for criticality is not a concern under current burial practices

Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography

International Nuclear Information System (INIS)

Thomas, J.M.; Garland, P.A.; White, M.B.; Daniel, E.W.

1980-09-01

This bibliography, a compilation of 474 references, is the fourth in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base was created for the Grand Junction Office of the Department of Energy's National Uranium Resource Evaluation Project by the Ecological Sciences Information Center, Oak Ridge National Laboratory. The references in the bibliography are arranged by subject category: (1) geochemistry, (2) exploration, (3) mineralogy, (4) genesis of deposits, (5) geology of deposits, (6) uranium industry, (7) geology of potential uranium-bearing areas, and (8) reserves and resources. The references are indexed by author, geographic location, quadrangle name, geoformational feature, and keyword

Potential supply system for uranium based upon a crustal abundance model

International Nuclear Information System (INIS)

Chavez-Martinez, M.L.

1982-01-01

The design of a computerized system for the estimation of uranium potential supply in the US was the primary objective of this study. Once completed, this system performs for various levels of economic variables, such as prices and estimation of potential uranium supply, without requiring the appraisal by geologists, area by area, of undiscovered uranium endowment. The main components that form the system are explicit models of endowment, exploration, and production. These component models are derived from engineering and geological data, and together, they comprise the system. This system is unique in that it likes physical attributes of endowment to time series of price and production. This linkage is made by simulating the activities of the US uranium industry, activities (exploration, mine development, and production) that are involved in the transformation of endowment to potential supply

Environment of deposition and stratigraphy of the uranium-bearing strata around Beaufort West, South Africa

International Nuclear Information System (INIS)

Horowitz, A.

1976-04-01

Palynological analyses of some 50 samples collected from uranium-bearing strata - as well as the layers immediately above and below them - around Beaufort West, South Africa, indicate that these sediments were laid down in a wide, rather shallow delta in Late Permian times. Most of the sediments are fluvio-deltaic, and most of the plant remains were transported from the north, the hinterland in those times. A considerable percentage of the microfossils, e.g. Veryhachium and hystrichospheres, are clearly from a marine environment. The occurrence of marine microfossils in the spectrum, as compared with those of terrestrial provenance, increases considerably southwards [af

Geology and uranium deposits of the Cochetopa and Marshall Pass districts, Saguache and Gunnison Counties, Colorado

International Nuclear Information System (INIS)

Olson, J.C.

1988-01-01

The geology of two districts in southwestern Colorado is described, particularly geologic features bearing on the uranium deposits, which are mainly fault controlled and localized near an unconformity beneath Tertiary volcanics. A genetic model for uranium ore formation is proposed to aid in exploration and evaluation of uranium potential; this model involves Tertiary siliceous tuffs as source rocks, leaching and solution of uranium by supergene ground waters, and localization of ore in favorable structural environments along faults and other permeable zones

Discussion on age and paleo geographical environment of ore bearing strata for sandstone-type uranium deposits in Bayanwula area, Erlian basin

International Nuclear Information System (INIS)

Fan Xiujun; Nie Fengjun; Chen Yiping; Wang Wei

2008-01-01

The sandstone-type uranium ore-bearing strata of Erlian basin is a suit of coarse crumb rocks that are mainly of river and marsh sedimentary faces, age of ore-bearing strata in this area is in dispute. By studying the palynology of ore-bearing strata in Bayanwula area, particularly the distribution of the spore and the pollen in the stratum and the comparison of domestic and the international palynology as- semblage, its age of the strata was identified belong to aptian-albian stages of the Later Early Cretaceous (Aptian-Albian) under substropic warm humid climate with the tendency to semihumid and semi-dryhot. The paleo geography was of the low-fiat and undulating topography, a few middling and high mountains distributing around the basin. (authors)

The uranium potential of the Bushveld igneous complex

International Nuclear Information System (INIS)

Andreoli, M.A.G.; Hart, R.J.; Brynard, H.J.; Camisani-Calzolari, F.A.G.M.

1987-06-01

A review of published literature supported by field observations on the uranium potential of the Bushveld Complex indicates that this geological region may host deposits with reserves in the range of a few thousand tons U 3 O 8 . The possibility that the Bushveld Complex or its cover rocks hosts, or has ever hosted in the past, giant uranium deposits such as those of Olympic Dam, Key Lake, Jabiluka or Rossing is considered to be unlikely. The potential for volcanogenic, caldera-type deposits in the Rooiberg Felsites remains at present untested. Recommendations for research currently sponsored by the AEC at the University of Pretoria are presented

Australia's uranium export potential

International Nuclear Information System (INIS)

Mosher, D.V.

1981-01-01

During the period 1954-71 in Australia approximately 9000 MT of U 3 O 8 was produced from five separate localities. Of this, 7000 MT was exported to the United Kingdom and United States and the balance stockpiled by the Australian Atomic Energy Commission (AAEC). Australia's uranium ore reserves occur in eight deposits in three states and the Northern Territory. However, 83% of Australia's reserves are contained in four deposits in lower Proterozoic rocks in the East Alligator River region of the Northern Territory. The AAEC has calculated Australia's recoverable uranium reserves by eliminating estimated losses during the mining and milling of the ores. AAEC has estimated reasonably assured resources of 289,000 MT of uranium at a recovery cost of less than US$80 per kilogram uranium. The companies have collectively announced a larger ore reserve than the Australian Atomic Energy Commission. This difference is a result of the companies adopting different ore reserve categories. On August 25, 1977, the federal government announced that Australia would develop its uranium resources subject to stringent environmental controls, recognition of Aboriginal Land Rights, and international safeguards. Australian uranium production should gradually increase from 1981 onward, growing to 10,000 to 15,000 MT by 1985-86. Further increases in capacity may emerge during the second half of the 1980s when expansion plans are implemented. Exploration for uranium has not been intensive due to delays in developing the existing deposits. It is likely that present reserves can be substantially upgraded if more exploration is carried out. 6 figures, 3 tables

ALPHA SPECTROMETRIC EVALUATION OF SRM-995 AS A POTENTIAL URANIUM/THORIUM DOUBLE TRACER SYSTEM FOR AGE-DATING URANIUM MATERIALS

Energy Technology Data Exchange (ETDEWEB)

Beals, D.

2011-12-06

Uranium-233 (t{sub 1/2} {approx} 1.59E5 years) is an artificial, fissile isotope of uranium that has significant importance in nuclear forensics. The isotope provides a unique signature in determining the origin and provenance of uranium-bearing materials and is valuable as a mass spectrometric tracer. Alpha spectrometry was employed in the critical evaluation of a {sup 233}U standard reference material (SRM-995) as a dual tracer system based on the in-growth of {sup 229}Th (t{sub 1/2} {approx} 7.34E3 years) for {approx}35 years following radiochemical purification. Preliminary investigations focused on the isotopic analysis of standards and unmodified fractions of SRM-995; all samples were separated and purified using a multi-column anion-exchange scheme. The {sup 229}Th/{sup 233}U atom ratio for SRM-995 was found to be 1.598E-4 ({+-} 4.50%) using recovery-corrected radiochemical methods. Using the Bateman equations and relevant half-lives, this ratio reflects a material that was purified {approx} 36.8 years prior to this analysis. The calculated age is discussed in contrast with both the date of certification and the recorded date of last purification.

Contribution to study of effects consecutive to alpha decay of uranium 238 in some uranium compounds and uranium ores

International Nuclear Information System (INIS)

Ordonez-Regil, E.

1985-06-01

The consequences of alpha decay of 238 U in uranium compounds and in uranium bearing ores have been examined in two ways: leaching of 234 Th and determination of the activity ratio of 234 U and 238 U. The results have been interpreted mainly in terms of the ''hot'' character of the nascent 234 Th atoms [fr

Distribution of uranium in kolm. Evidence from backscattered electron imagery

Energy Technology Data Exchange (ETDEWEB)

Parnell, J [Dep. of Geology, Belfast (Northern Ireland)

1985-02-06

The distribution of uranium in kolm from Upper Cambriam alum shales has been studied using backscattered electron imagery, and found to be concentrated in discrete mineral phases. Authigenic minerals in kolm include pyrite, galena, and a cerium-bearing mineral referable to monazite. Uranium occurs within the monazite and generally shows a close relationship with phosphorus. Uranium bearing monazite has also been identified within the host alum shale.

Distribution of indoor radon concentrations and uranium-bearing rocks in Texas

International Nuclear Information System (INIS)

Hudak, P.F.

1996-01-01

The purpose of this study was to compare regional patterns of indoor radon concentration with uranium-bearing rock zones and county populations in Texas. Zones yielding radon concentrations that are relatively high for Texas include shale and sandstone in northwest Texas; red beds in north-central Texas; felsic volcanic rocks in west Texas; and sandstone, limestone, and igneous rocks in central Texas. Located in northwest Tecas, only five of the 202 counties evaluated have mean indoor radon concentrations above 4.0 pCi l -1 . Two of those counties have populations above the state median of 20115. The highest county mean concentration is 8.8 pCi l -1 . Results of the study suggest that (1) regional geology influences indoor radon concentrations in Texas, (2) statewide, the radon concentrations are relatively low, (3) highly populated counties do not coincide with regions of high indoor radon concentration, and (4) regions that may warrant further monitoring include northwest Texas and, to a lesser degree, west and central Texas. (orig.)

Biological treatment of nitrate bearing wastewater from a uranium production plant

International Nuclear Information System (INIS)

Benear, A.K.; Kneip, R.W.

1988-01-01

The Feed Materials Production Center (FMPC) produces uranium metal products used for DOE defense programs resulting in the generation of nitrate-bearing wastewaters. To treat these wastewaters, a two-column fluidized bed biodenitrification facility (BDN) was constructed at the FMPC. The operation of the BDN resulted in substantial compliance with the design criteria limits for nitrate from July through November, 1987. Since the BDN surge lagoon (BSL) proved inadequate for providing nitrate concentration equalization, the BDN feed nitrate concentration fluctuated widely throughout this period of operation. BDN effluent caused a doubling of the hydraulic loading and a tripling of the organic loading on the FMPC sewage treatment plant (STP). Better control of the methanol feed to the BDN, coupled with reduced throughput and improved preaeration, caused a significant improvement in the operation of the STP. The overloading of the STP prompted a decision to add a stand-alone effluent treatment system to the BDN

Ore bearing system and hydrological characteristics of mineralized sector in Hushiliang area

International Nuclear Information System (INIS)

Zhang Zhaolin; Liu Zhengbang; Miao Aisheng

2010-01-01

Hushiliang area is one of the best uranium ore bearing areas in Erdos basin from the point of fluvial sedimentary system and uranium geochemical environment, So far, three mineralized sector has been found that are Nalingou, Nongshengxin, Baobeigou. By using the first-hand data of uranium regional survey in this area lately and systematically comparing and analyzing of the hydrological structure in the mineralized sector of this area, the thesis ascertain the ore and water bearing fluid reservoir's spatial relationship generally, and argues that the Zhiluo formation ore and water bearing fluid reservoir in this area is a unified underwater ore bearing system, and the orebody's hydrological structure is propitious in the distributary channel and unpropitious in the main channel because of deep ore bearing layer to the ISL. (authors)

Uranium in the Bunter sediments of the Polish area

International Nuclear Information System (INIS)

Saldan, M.; Strzelecki, R.

1980-01-01

Uranium mineralization occurring in the Triassic sediments in the Polish area is discussed. Systematic work conducted for over ten years revealed the presence of uranium mineralization in the following geological units: Peribaltic syneclize, Fore-Sudetic monocline, Zary pericline and Pomerania trough. Out of three uranium-bearing horizons which can be correlated with each other two (the lower and the middle) are connected with the Middle Bunter, while the upper horizon is related to the Upper Bunter. Mineralization was found in sandstones, conglomerates, mudstones and claystones and, in the Fore-Sudetic monocline, also in carbonates. Among uranium minerals uranium black and coffinite were identified. In addition to uranium, increased vanadium, selenium and molybdenum contents were found in the sandstones. Some of the uranium-bearing horizons are of economic value. (author)

Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography

Energy Technology Data Exchange (ETDEWEB)

Garland, P.A.; Thomas, J.M.; Brock, M.L.; Daniel, E.W. (comps.)

1980-06-01

A bibliography of 479 references encompassing the fields of uranium and thorium geochemistry and mineralogy, geology of uranium deposits, uranium mining, and uranium exploration techniques has been compiled by the Ecological Sciences Information Center of Oak Ridge National Laboratory. The bibliography was produced for the National Uranium Resource Evaluation Program, which is funded by the Grand Junction Office of the Department of Energy. The references contained in the bibliography have been divided into the following eight subject categories: (1) geology of deposits, (2) geochemistry, (3) genesis O deposits, (4) exploration, (5) mineralogy, (6) uranium industry, (7) reserves and resources, and (8) geology of potential uranium-bearing areas. All categories specifically refer to uranium and thorium; the last category contains basic geologic information concerning areas which the Grand Junction Office feels are particularly favorable for uranium deposition. The references are indexed by author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword.

Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography

International Nuclear Information System (INIS)

Garland, P.A.; Thomas, J.M.; Brock, M.L.; Daniel, E.W.

1980-06-01

A bibliography of 479 references encompassing the fields of uranium and thorium geochemistry and mineralogy, geology of uranium deposits, uranium mining, and uranium exploration techniques has been compiled by the Ecological Sciences Information Center of Oak Ridge National Laboratory. The bibliography was produced for the National Uranium Resource Evaluation Program, which is funded by the Grand Junction Office of the Department of Energy. The references contained in the bibliography have been divided into the following eight subject categories: (1) geology of deposits, (2) geochemistry, (3) genesis O deposits, (4) exploration, (5) mineralogy, (6) uranium industry, (7) reserves and resources, and (8) geology of potential uranium-bearing areas. All categories specifically refer to uranium and thorium; the last category contains basic geologic information concerning areas which the Grand Junction Office feels are particularly favorable for uranium deposition. The references are indexed by author, geographic location, quadrangle name, geoformational feature, taxonomic name, and keyword

Regional metallogenic essential factor of granite-type uranium deposits in Guangdong province

International Nuclear Information System (INIS)

Pan Yongzheng

1987-12-01

The uranium origin, activation region, red basin, and fault depressed zone constitute the regional metallogenic essential factor of the four united like one granite-type uranium deposits in the post-Caledonian rise area in China. In the development of sub-geosyncline in the Caledonian, the clastic formation with widely deposited carbon, silicon, mud rich bearing organic matter, which drow a great amount of uranium formed the uranium-bearing system in the Sinian-Cambrian period. The magmagranite activation in a large scale in the Indosinian-Yenshanian period caused the continental crust to be suffered strong reformation and the uranium-bearing basement system to be eroded and remelted, and formed the rich uranium granite body. The multiple structure-magmatic movement further made the uranium in the rock body suffered the endogenic, structure, supergene active reformation, and produced mobile uranium concentrated area. Under the dry and hot paleoclimate condition in the Cretaceous-Tertiary period, strong weathering and hot water leaching forced uranium to be concentrated into the 'rock origin activation' type uranium deposits in the fault depressed zone

The geochronology of uranium deposits in the Great Bear batholith, Northwest Territories

International Nuclear Information System (INIS)

Miller, R.G.

1982-01-01

The oldest uranium mineralisation found in the Great Bear batholith during this study may be hydrothermal pitchblende-hematite veins at Hottah Lake. Their apparent age of 2058 +- 34 Ma can also be explained by the contamination of deposits only 440 +- 57 Ma old, which is the age of pitchblende veins nearby. Numerous pendants of metamorphosed, uraninite-bearing 'black sand' placers in a north-trending belt west of the Wopmay Fault are 1860 +- 20 Ma old, the age of the granites that intrude them. Mineralisation at Echo Bay is from 1500 +- 10 to 1424 +- 29 Ma old, and extends up to 30 km north and 40 km south of Echo Bay. The JD claims contain small quartz vein deposits dated at 535 +- 164 and 1092 +- 115 Ma. At Mountain Lake, pitchblende in Helikian sandstones overlying the batholith is 1076 +- 96 Ma old. Polymetallic veinlets at Mazenod Lake are 457 +- 26 Ma old. Pitchblende in a giant quartz vein at the Rayrock mine is 511 +- 86 Ma old. Small pitchblende veins east of the batholith along the Coppermine River are between 400 and 660 Ma old. All the deposits are either between approximately 395 and 660 Ma old, or indicate remobilization during this interval. These events may be related to a marine transgression and regression approximately 600 and 350 Ma ago, respectively

78 FR 25484 - License Amendment for Anadarko Petroleum Corporation, Bear Creek Facility, Converse County, Wyoming

Science.gov (United States)

2013-05-01

... Petroleum Corporation, Bear Creek Facility, Converse County, Wyoming AGENCY: Nuclear Regulatory Commission.... 47 for its Bear Creek Uranium Mill facility in Converse County, Wyoming. The NRC has prepared an... INFORMATION: I. Background The Bear Creek Uranium Mill operated from September 1977 until January 1986, and...

Uranium-series dating of fossil bones from alpine caves

International Nuclear Information System (INIS)

Leitner-Wild, E.; Steffan, I.

1993-01-01

During the course of an investigation of fossil cave bear populations the uranium-series method for absolute age determination has been applied to bone material. The applicability of the method to bone samples from alpine caves is demonstrated by the concordance of U/Th and U/Pa ages and cross-checks with the radiocarbon method. Stratigraphic agreement between bone ages and carbonate speleothem ages also indicates the potential of the uranium-series method as a suitable tool for the age determination of fossil bones from alpine cave environments. (Author)

Possible application of underground leaching of uranium in ''sandstone'' deposits by drilling method

International Nuclear Information System (INIS)

Bareja, E.

1988-01-01

Underground leaching as the method for excavation of uranium from its sandstone deposits is applied in many countries. A preliminary examination of a possible use of this method to sandstone deposits in Poland suggests it to be analysed against the uranium mineralization, noted within sediments of the Lower Triassic age in the Peribaltic Syneclise in the Krynica Morska - Paslek area. Before a definite decision on such exploitation of uranium, geologic and hydrogeologic conditions should be studied of individual uranium-bearing beds, particularly their permeability and insulation by impermeable claystone series as well as extraction of uranium from its bearing sandstones. The depth at which uranium-bearing beds occur, forms a very important item. The depth at which uranium ores described in literature and exploited by this method occur, does not exceed 700 m. 7 refs. (author)

PROCESS OF RECOVERING URANIUM

Science.gov (United States)

Carter, J.M.; Larson, C.E.

1958-10-01

A process is presented for recovering uranium values from calutron deposits. The process consists in treating such deposits to produce an oxidlzed acidic solution containing uranium together with the following imparities: Cu, Fe, Cr, Ni, Mn, Zn. The uranium is recovered from such an impurity-bearing solution by adjusting the pH of the solution to the range 1.5 to 3.0 and then treating the solution with hydrogen peroxide. This results in the precipitation of uranium peroxide which is substantially free of the metal impurities in the solution. The peroxide precipitate is then separated from the solution, washed, and calcined to produce uranium trioxide.

Mortimer Hills pegmatite uranium prospect: a Rossing-type uranium deposit in the Gascoyne Province

International Nuclear Information System (INIS)

Carter, J.D.

1984-01-01

A uraninite-bearing pegmatite of large dimensions in the Gascoyne Province is described. The pegmatite is compared with the Rossing uranium ore body of South West Africa and the two are shown to have common characteristics. Exploration recommendations for Rossing-type uranium mineralization in the Gascoyne Province are made

Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. [474 references

Energy Technology Data Exchange (ETDEWEB)

Thomas, J.M.; Garland, P.A.; White, M.B.; Daniel, E.W.

1980-09-01

This bibliography, a compilation of 474 references, is the fourth in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base was created for the Grand Junction Office of the Department of Energy's National Uranium Resource Evaluation Project by the Ecological Sciences Information Center, Oak Ridge National Laboratory. The references in the bibliography are arranged by subject category: (1) geochemistry, (2) exploration, (3) mineralogy, (4) genesis of deposits, (5) geology of deposits, (6) uranium industry, (7) geology of potential uranium-bearing areas, and (8) reserves and resources. The references are indexed by author, geographic location, quadrangle name, geoformational feature, and keyword.

The Tosudite, a clayey mineral which marks the uranium-bearing mineralisation in the Arlit area (Niger)

International Nuclear Information System (INIS)

Billon, S.; Beaufort, D.; Sardini, P.; Wattinne, A.

2009-01-01

The authors report an investigation which aims at the identification of clayey minerals in the sedimentary series of the Tim Mersoi basin in Niger, and of their petrogenetic meaning. Based on spectrometry and on chemical micro-analysis, they identify the different components of the Tosudite present in the clayey phase: a sodoite-type chlorite and a montmorillonite-type smectite. The presence of Tosudite is interpreted as the result of a post-diagenetic episode related to infiltrations of magnesium-based and oxidative solutions. The way the uranium-bearing minerals precipitated suggests that the Tosudite is a marker of a mineralisation episode

The sedimentology of uranium-bearing sandstones on the Waterval portion of the farm Brandewyns Gat 214, Beaufort West area

International Nuclear Information System (INIS)

Cole, D.I.

1980-08-01

The sedimentology of two uranium-bearing sandstones on the Waterval portion of the farm Brandewyns Gat 214 was studied by means of 36 vertical profiles measured across, through and adjacent to 4 mineralised deposits. The vertical profiles basically consist of a succession of sedimentary facies. A total of 19 facies was recognised within the fluvial sandstone sequence according to the criteria of grain-size and sedimentary structure. Transitions between the facies were subjected to a Markov chain analysis in order to delineate Markov-dependent transitions. Uranium mineralisation occurs mostly within the lower half of the fluvial sandstone sequence and is confined to the coarser-grained sedimentary facies. These facies probably acted as suitable aquifers for the transport of uraniferous solutions and permeability differences between the sandstone and the underlying mudstone and siltstone must have restricted these solutions to the lower half of the channel sandstone. The massive mudstone facies contains 13 per cent of the total cumulative thickness of mineralisation. This mineralisation probably originated from synchronously deposited tuffaceous material. Subsequent migration of uraniferous solutions may have concentrated the uranium

Bio leaching of Uranium - bearing material from Abu Thor area, West Central Sinai, Egypt for recovering uranium

International Nuclear Information System (INIS)

Abd El Wahab, G.M.; Amin, M.M.; Aita, S.K.

2012-01-01

A uranium-bearing material was recorded within the Intra-Carboniferous Paleokarst Profile of Um-Bogma Formation at Abu Thor area, West Central Sinai, Egypt. The present paper is concerned with the bio leaching of U and Cu using Aspergillus Niger (A. Niger) followed their proper recovery. The working Abu Thor representative sample assays 0.22% U as the element of interest as well as up to 25% CuO beside the other rock constituents SiO 2 (33%), Al 2 O 3 (10.4%) and CaO(8.5%). The effective bio leaching of U and Cu from Abu Thor ore sample using A.Niger was performed at the following optimum conditions: an incubation time of 6 days, sample/ liquid (S/L) ratio of 1/10, ph value of 1 and a temperature of 60 degree C. The prepared bio leach liquor assays 0.19 g/l of U and 15.8 g/l of Cu with leaching efficiencies of 97% and 79%, respectively. Uranium was recovered using 25% TBP in kerosene at O/A ratio of 1/1 and contact time of 5 min with achieved extraction efficiency of 96%. However the stripping of U was conducted by using 8% Na 2 CO 3 at A/O ratio of 1/1 and contact time of 5 min with stripping efficiency reached 99%. On the other hand, Cu was directly precipitated as CuS using the freshly released H 2 S gas with the addition of solid Na 2 S. The optimum precipitation conditions were S/L ratio of 1/100, ph 1.5 and room temperature where the precipitation efficiency of Cu achieved 99%

Uranium deposits in granitic rocks

International Nuclear Information System (INIS)

Nishimori, R.K.; Ragland, P.C.; Rogers, J.J.W.; Greenberg, J.K.

1977-01-01

This report is a review of published data bearing on the geology and origin of uranium deposits in granitic, pegmatitic and migmatitic rocks with the aim of assisting in the development of predictive criteria for the search for similar deposits in the U.S. Efforts were concentrated on the so-called ''porphyry'' uranium deposits. Two types of uranium deposits are primarily considered: deposits in pegmatites and alaskites in gneiss terrains, and disseminations of uranium in high-level granites. In Chapter 1 of this report, the general data on the distribution of uranium in igneous and metamorphic rocks are reviewed. Chapter 2 contains some comments on the classification of uranium deposits associated with igneous rocks and a summary of the main features of the geology of uranium deposits in granites. General concepts of the behavior of uranium in granites during crustal evolution are reviewed in Chapter 3. Also included is a discussion of the relationship of uranium mineralization in granites to the general evolution of mobile belts, plus the influence of magmatic and post-magmatic processes on the distribution of uranium in igneous rocks and related ore deposits. Chapter 4 relates the results of experimental studies on the crystallization of granites to some of the geologic features of uranium deposits in pegmatites and alaskites in high-grade metamorphic terrains. Potential or favorable areas for igneous uranium deposits in the U.S.A. are delineated in Chapter 5. Data on the geology of specific uranium deposits in granitic rocks are contained in Appendix 1. A compilation of igneous rock formations containing greater than 10 ppM uranium is included in Appendix 2. Appendix 3 is a report on the results of a visit to the Roessing area. Appendix 4 is a report on a field excursion to eastern Canada

Biotechnology for uranium extraction and environmental control

International Nuclear Information System (INIS)

Natarajan, K.A.

2012-01-01

India is looking forward to augmenting mining and extraction of uranium mineral for its nuclear energy needs. Being a radio-active mineral, mining and processing of uranium ore deposits need be carried out in an environmentally acceptable fashion. In this respect, a biotechnological approach holds great promise since it is environment-friendly, cost-effective and energy-efficient. There are several types of microorganisms which inhabit uranium ore bodies and biogenesis plays an important role in the mineralisation and transport of uranium-bearing minerals under the earth's crust. Uranium occurrences in India are only meagre and it becomes essential to tap effectively all the available resources. Uraninite and pitchblende occurring along with sulfide mineralisation such as pyrite are ideal candidates for bioleaching. Acidithiobacillus ferrooxidans present ubiquitously in the ore deposits can be isolated, cultured and utilised to bring about efficient acidic dissolution of uranium. Many such commercial attempts to extract uranium from even lean ores using acidophilic autotrophic bacteria have been made in different parts of the world. Anaerobes such a Geobacter and Sulfate Reducing Bacteria (SRB) can be effectively used in uranium mining for environmental control. Radioactive uranium mined wastes and tailing dumps can be cleaned and protected using microorganisms. In this lecture use of biotechnology in uranium extraction and bioremediation is illustrated with practical examples. Applicability of environment-friendly biotechnology for mining and extraction of uranium from Indian deposits is outlined. Commercial potentials for bioremediation in uranium-containing wastes are emphasised. (author)

A study of U-Pb isotopic evolutionary system in Chanziping uranium deposit

International Nuclear Information System (INIS)

Xu Weichang; Huang Shijie; Xia Yuliang.

1988-01-01

Chanziping uranium deposit occurred in the black siliceous slate of Lower cambrian. The uranium mineralization was controlled by both interstratified fault belt and the ore-bearing beds. Based on the study of the U-Pb isotopic system of the various rocks, ores and minerals in the ore-bearing beds, the authors find out the obvious disequilibrium of U-Pb isotopic composition in most rock samples which indicates the loss of uranium form the ore-bearing beds and surrounding granite. Its counting loss ranges from 30 to 80%. The age of rich ores of the U-Pb concordance diagram and the U-Pb three stage model are t 1 = 523 ± 19M. Y. , t 2 = 22 ± 2 M.Y.. The isochronal ages for pitchblend are 75 ± 4 M.Y., 43 ± 7 M.Y., and for rock is 416 M.y.. These data shows that the uranium in ore-bearing beds was mainly derived from the ore-bearing beds itself and partly from the surrounding granite. The ore deposit can be considered to be of stratabound uranium deposit of sedimentation and late transformation type

Uranium in spring water and bryophytes at Basin Creek in central Idaho

International Nuclear Information System (INIS)

Shacklette, H.T.; Erdman, J.A.

1982-01-01

Arkosic sandstones and conglomerates of Tertiary age beneath the Challis Volcanics of Eocene age at Basin Creek, 10 km northeast of Stanley, Idaho, contain uranium-bearing vitrainized carbon fragments. The economic potential of these sandstones and conglomerates is currently being assessed. Water from 22 springs and associated bryophytes were sampled; two springs were found to contain apparently anomalous concentrations (normalized) of uranium. Water from a third spring contained slightly anomalous amounts of uranium, and two species of mosses at the spring contained anomalous uranium and high levels of both cadmium and lead. Water from a fourth spring was normal for uranium, but the moss from the water contained a moderate uranium level and highly anomalous concentrations of lead, germanium, and thallium. These results suggest that, in the Basin Creek area, moss sampling at springs may give a more reliable indication of uranium occurrence than would water sampling. (Auth.)

Geology of the Cannonball Formation (Paleocene) in the Williston basin, with reference to uranium potential. Report of investigation No. 57

International Nuclear Information System (INIS)

Cvancara, A.M.

1976-01-01

The Paleocene Cannonball Formation is a marine, non-lignitic-bearing clastic sequence in the lower part of the Fort Union Group. It is overlain by the lignite-bearing Tongue River Formation in places and both overlain and underlain by the lignite-bearing Ludlow Formation in places. The Cannonball crops out primarily in southwest-central North Dakota and probably occurs throughout the western one-half of the state. It occurs also in northwestern South Dakota and may extend into parts of Saskatchewan and Manitoba. Poorly consolidated, very fine- to fine-grained, light to medium brownish yellow-weathering sandstone and light gray-weathering, sandy mudstone are the principal types of lithology. Mudstone generally predominates in North Dakota whereas sandstone seems to predominate in South Dakota. Although uranium in the Williston basin has been found almost entirely in lignite and nonmarine carbonaceous rocks, its occurrence in the marine Cannonball Formation is possible. If the Cannonball, Ludlow, Tongue River, and Sentinel Butte Formations are at least partly penecontemporaneous, a variety of depositional environments were in areal juxtaposition during the Paleocene. Streams originating or passing through coastal plain bogs could have carried uranium ions (derived from volcanic materials) to the Cannonball sea where they were deposited syngenetically. Epigenetic uranium may occur in Cannonball mudstones or sandstones that directly underlie the Ludlow Formation, which is known to contain volcanic materials

Potential of Melastoma malabathricum as bio-accumulator for uranium and thorium from soil

Energy Technology Data Exchange (ETDEWEB)

Saat, Ahmad, E-mail: ahmad183@salam.uitm.edu.my [Institute of Science, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia); Kamsani, Ain Shaqina; Kamri, Wan Nur Aina Nadzira; Talib, Nur Hasyimah Mat; Wood, Ab Khalik; Hamzah, Zaini [Faculty of Applied Sciences, Universiti Teknologi MARA, 40450 Shah Alam (Malaysia)

2015-04-29

Uranium and Thorium are naturally occuring radionuclides. However, due to anthropogenic activities in some locations their concentrations in the soils could be elevated. This study explores the potential of Melastoma malabathricum (locally known as ‘pokok senduduk’) as bio-accumulator of uranium and thorium from soils of three different study areas, namely former tin mining, industrial and residential/commercial areas in Peninsular Malaysia. The study found elevated concentrations of uranium and thorium in former tin mining soils as compared to natural abundance. However in industral and residential/commercial areas the concentrations are within the range of natural abundance. In terms of transfer factor (TF), in ex-mining areas TF > 1 for uranium in the leaf, stem and roots, indicating accumulation of uranium from soil. However for thorium TF < 1, indicating the occurence of transfer from soil to root, stem and leaf, but no accumulation. For other areas only transfer of uranium and thorium were observed. The results indicated the potential of Melastoma malabathricum to be used as bio-accumulatior of uranium, especially in areas of elevated concentration.

Potential of Melastoma malabathricum as bio-accumulator for uranium and thorium from soil

International Nuclear Information System (INIS)

Saat, Ahmad; Kamsani, Ain Shaqina; Kamri, Wan Nur Aina Nadzira; Talib, Nur Hasyimah Mat; Wood, Ab Khalik; Hamzah, Zaini

2015-01-01

Uranium and Thorium are naturally occuring radionuclides. However, due to anthropogenic activities in some locations their concentrations in the soils could be elevated. This study explores the potential of Melastoma malabathricum (locally known as ‘pokok senduduk’) as bio-accumulator of uranium and thorium from soils of three different study areas, namely former tin mining, industrial and residential/commercial areas in Peninsular Malaysia. The study found elevated concentrations of uranium and thorium in former tin mining soils as compared to natural abundance. However in industral and residential/commercial areas the concentrations are within the range of natural abundance. In terms of transfer factor (TF), in ex-mining areas TF > 1 for uranium in the leaf, stem and roots, indicating accumulation of uranium from soil. However for thorium TF < 1, indicating the occurence of transfer from soil to root, stem and leaf, but no accumulation. For other areas only transfer of uranium and thorium were observed. The results indicated the potential of Melastoma malabathricum to be used as bio-accumulatior of uranium, especially in areas of elevated concentration

Lithofacies-paleo-geography and uranium sedimentary facies in Hailar basin

International Nuclear Information System (INIS)

Qi Fucheng

1992-01-01

Cretaceous-Tertiary sedimentary paleo-structure and lithofacies-paleo-geography in Hailar Basin are described. Taking Chenqi coal field as an example, the sedimentary facies pattern of coal-bearing series characterized by alternating sedimentation of fluviatile and lacustrine-swampy facies is reconstructed. It is pointed out that this sedimentary facies not only controls the sedimentation and distribution of syngenetic uranium mineralization, but also is a favourable place that converges uranium-bearing solution and reduces and precipitates uranium for the second time in epigenetic mineralization

Uranium minerals in Upper Carboniferous rocks in the Nowa Ruda region

International Nuclear Information System (INIS)

Bareja, E.

1981-01-01

Results of mineralogical studies on uranium in Upper Carboniferous rocks (Glinik Beds - Westphalian C - D and Ludwikowice Beds - Stephanian) in the vicinities of Nowa Ruda (Central Sudetic Depression) are presented. Uranium mineralization is here related to sandstones and polymictic conglomerates with clay and clay-carbonate cement. The major uranium-bearing horizon was found in middle part of the Glinik Beds, and some increase in uranium content - at the base of that unit. In the case of Stephanian rocks, points with uranium mineralization were found in various parts of the Ludwikowice Beds sequence: in basal conglomerate horizon and platy sandstones. Uranium minerals mainly occur in cement of sandstones and conglomerates. They were mainly identified as uranium blende and minerals of the sulfate group - zippeite and uranopilite. Mineralized uranium-bearing horizons display mineral paragenesis typical of Upper Carboniferous rocks of the Central Sudetic Depression: uranium blende, pyrite, chalcopyrite, sphalerite and galena. (author)

Radiological impacts of uranium recovery in the phosphate industry

International Nuclear Information System (INIS)

Ryan, M.T.

1981-01-01

This article characterizes the occupational and public radiological health impacts associated with phosphate mining and milling. These impacts are related to the phosphate industry's uranium production potential and are compared with those associated with conventional uranium mining and milling. The radiological impacts resulting from occupational and nonoccupational exposures are assessed. Occupational exposures in phosphate facilities are compared to background exposures and radiological population dose assessments, which characterize important radionuclides and exposure pathways. The following conclusions were reached: (1) public consequences of phosphate mining will occur whether or not uranium is recovered as a by-product, (2) radiological consequences of phosphate mining may be comparable to those associated with uranium mining and milling per unit uranium production, (3) radiological impacts via surface waterways and crops fertilized with uranium-bearing phosphates are of minor consequence, and (4) major radiological public health problems associated with phosphate mining are related to radon and radon progeny exposures in structures built on reclaimed lands or with phosphate mining residues, although the magnitudes of these impacts are difficult to evaluate with current data

Two main types of uranium deposit within phanerozoic formations of Ukraine

International Nuclear Information System (INIS)

Shumlyanskiy, V.A.

1997-01-01

The two main types of uranium deposits occurring within Phanaerozoic formations of Ukraine are described. They consist of uraniferous bearing bitumen in the Upper Carboniferous to Lower Triassic red beds, and infiltration (roll front type) uranium ores, occurring in the sediments filling ancient Paleogene river valleys. The first deposit type include black to dark brown beds of disseminated to massive bitumen occurring respectively as ozyantraxolite and oxykerite. These beds include uranium, as well as other metals. This uranium mineralization is dated at 195 to 200 million years old. The second type includes infiltration deposits in Paleogene coal bearing sediments, with the uranium mineralization occurring in the upper part of the sequence. The sediments occur within paleovallyes eroded into the underlying crystalline basement of the Ukraine shield and its weathered crust. The paleovalleys extend to a depth of 70 to 90 metres. The coal bearing sediments are overlain by sediments of younger age. Several uranium deposits of the second type are known, including a few identified as being of industrial grade. (author). 7 figs

Oxygen potential of uranium--plutonium oxide as determined by controlled-atmosphere thermogravimetry

International Nuclear Information System (INIS)

Swanson, G.C.

1975-10-01

The oxygen-to-metal atom ratio, or O/M, of solid solution uranium-plutonium oxide reactor fuel is a measure of the concentration of crystal defects in the oxide which affect many fuel properties, particularly, fuel oxygen potential. Fabrication of a high-temperature oxygen electrode, employing an electro-active tip of oxygen-deficient solid-state electrolyte, intended to confirm gaseous oxygen potentials is described. Uranium oxide and plutonium oxide O/M reference materials were prepared by in situ oxidation of high purity metals in the thermobalance. A solid solution uranium-plutonium oxide O/M reference material was prepared by alloying the uranium and plutonium metals in a yttrium oxide crucible at 1200 0 C and oxidizing with moist He at 250 0 C. The individual and solid solution oxides were isothermally equilibrated with controlled oxygen potentials between 800 and 1300 0 C and the equilibrated O/M ratios calculated with corrections for impurities and buoyancy effects. Use of a reference oxygen potential of -100 kcal/mol to produce an O/M of 2.000 is confirmed by these results. However, because of the lengthy equilibration times required for all oxides, use of the O/M reference materials rather than a reference oxygen potential is recommended for O/M analysis methods calibrations. (auth)

Estimation of potential uranium resources

International Nuclear Information System (INIS)

Curry, D.L.

1977-09-01

Potential estimates, like reserves, are limited by the information on hand at the time and are not intended to indicate the ultimate resources. Potential estimates are based on geologic judgement, so their reliability is dependent on the quality and extent of geologic knowledge. Reliability differs for each of the three potential resource classes. It is greatest for probable potential resources because of the greater knowledge base resulting from the advanced stage of exploration and development in established producing districts where most of the resources in this class are located. Reliability is least for speculative potential resources because no significant deposits are known, and favorability is inferred from limited geologic data. Estimates of potential resources are revised as new geologic concepts are postulated, as new types of uranium ore bodies are discovered, and as improved geophysical and geochemical techniques are developed and applied. Advances in technology that permit the exploitation of deep or low-grade deposits, or the processing of ores of previously uneconomic metallurgical types, also will affect the estimates

Uranium Content in the Geological Samples of Different River Valleys in the Dauki fault Belt of Jaintiapur

International Nuclear Information System (INIS)

Chowdhury, Minhaz ul Islam; Ahmed Monir; Bhuiyan Abu Daiyan; Akon Eunus

1996-01-01

Thirty four geological samples that include six radioactive rock samples, four soil samples, two ooze samples,twelve stream-sediment samples and ten water samples, collected during a field survey in Jaintiapur area of the Dauki fault belt, oriented to the study on probable mobility of uranium either as detritus or in aquatic solution through the region, have been investigated with fluorimeter so as to find out content of uranium in the samples. The investigation aims at determining geochemical significance on uranium occurrence prevailing in the area. In general, the content of uranium in the rock samples lies in average distribution of geochemical interest. However, 194 ppm of uranium content in the gross material of the rock sample, collected from Lalakhal anomaly that records 1500 cps in situ, bears geochemical significance. But, the anomaly being associated with a cross -bedding, the presence of uranium may be inferred as an accumulation in placer sediment transported from a nearby source, Despite absence of in situ radiometric anomalies in the overall geological formations other than the Tipam and the Dupitila Sandstone members as encountered in the traverse of Sari valley , the area, in general, appears to be potential for possible occurrence of uranium. The transported stream sediments ooze and surface run-off water, as collected from the Rangapani, the Sari and even the Nayagang show geochemically significant distribution of uranium. Laboratory analyses of soil samples refers to dispersion of U bearing materials in the soil along the major channels.Uranium content in the surface run-off water of the Sari, the Rangapani and the Nayagang that have originated from the uranium bearing Meghalayan hills strongly support previous inference on mobility of uranium in aquatic solution through the geological formations of the area for possible formation of secondary uranium deposits. Eventually, prevailing geological evidences advocate that the area may be brought

Reactions of plutonium and uranium with water: Kinetics and potential hazards

International Nuclear Information System (INIS)

Haschke, J.M.

1995-12-01

The chemistry and kinetics of reactions between water and the metals and hydrides of plutonium and uranium are described in an effort to consolidate information for assessing potential hazards associated with handling and storage. New experimental results and data from literature sources are presented. Kinetic dependencies on pH, salt concentration, temperature and other parameters are reviewed. Corrosion reactions of the metals in near-neutral solutions produce a fine hydridic powder plus hydrogen. The corrosion rate for plutonium in sea water is a thousand-fold faster than for the metal in distilled water and more than a thousand-fold faster than for uranium in sea water. Reaction rates for immersed hydrides of plutonium and uranium are comparable and slower than the corrosion rates for the respective metals. However, uranium trihydride is reported to react violently if a quantity greater than twenty-five grams is rapidly immersed in water. The possibility of a similar autothermic reaction for large quantities of plutonium hydride cannot be excluded. In addition to producing hydrogen, corrosion reactions convert the massive metals into material forms that are readily suspended in water and that are aerosolizable and potentially pyrophoric when dry. Potential hazards associated with criticality, environmental dispersal, spontaneous ignition and explosive gas mixtures are outlined

Potentiality of uranium biosorption from nitric acid solutions using shrimp shells

International Nuclear Information System (INIS)

Ahmed, S.H.; El Sheikh, E.M.; Morsy, A.M.A.

2014-01-01

Biosorption has gained important credibility during recent years because of its good performance and low cost. This work is concerned with studying the potentiality of the chitin component of the shrimp shells for uranium biosorption from nitric acid liquid solutions. The structural characteristics of the working chitin have been determined via Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was examined using Scanning Electron Microscopy (SEM). The adsorption capacity of biomass was investigated experimentally. The influence of contact time, pH, metal ion concentration, solution volume to mass ratio and temperature were evaluated and the results were fitted using adsorption isotherm models. The kinetic of uranium biosorption was also investigated as well as biosorption thermodynamic. - Graphical abstract: Physicochemical process of biosorption is known to be promising technique due to the ease of operation and comparable low cost of biosorbant application. Chitin flakes extracted from shrimp shells show potentiality in uranium adsorption reached 7.48 mg uranium at the following conditions: 60 min contact time, pH 3.66, 50:1 V/m ration and at room temperature. The theoretical sorption capacity was 25.31 mg g −1 , according to Langmuir isotherm model. The rate of sorption follows pseudo second-order. The nature of biosorption process is spontaneous and exothermic. - Highlights: • This study shows the potentially for shrimp shell beads for uranium adsorption. • The max. biosorption was achieved at pH 3.6, contact time 60 min, S/L ratio 1:50. • Uranium sorption follows Langmuir isotherm with theoretical capacity of 25.31 g/kg. • The nature of sorption process of the sorbents is spontaneous and exothermic. • The rate of sorption follows pseudo second-order

The main advance and achievements in the potential evaluation of uranium resource in China

International Nuclear Information System (INIS)

Zhang Jindai; Guo Qingyin; Li Youliang; Li Ziying; Cai Yuqi; Han Changqing

2012-01-01

The national uranium resources potential evaluation is one of the important national census in China. The evaluation is based on the data and results accomplished by nuclear geological industry in last decades and wholly performed on GIS platform by absorbing related technology and geological achievement in home and broad, and has figured out 329 uranium predicted mineralization areas and estimated more than 2000000 tones resource on a national scale. Innovative achievements has been made in the classification of uranium deposit type and mineralization belt, integration of geological-geophysical-geochemical-remote sensing information and research of uranium mineralization pattern. For the first time, the potential evaluation has been performed totally by digitalisation and information, the evaluation will provide important evidence for developing middle-long term planning of uranium exploration and laid good foundation to future dynamic and regular evaluation of uranium resource in China. (authors)

The uranium market 1980 - 1990

International Nuclear Information System (INIS)

Darmayan, Philippe

1980-01-01

The Supply and Demand Committee of the Uranium Institute was established to monitor continuously information and developments bearing on the uranium market and to publish from time to time reports giving its views on the supply and demand outlook. The last Uranium institute supply and demand report was published in July 1979 and a summary was given by Mr. Erkes at the last Uranium Institute symposium. Its main conclusions were that from 1979 to 1990 the flexibilities of the market were such as to offer adequate scope to producers and consumers of uranium to ensure a balance between supply and demand. Is that conclusion still valid one and a half years later [fr

Formation conditions for regenerated uranium blacks in uranium-molybdenum deposits

International Nuclear Information System (INIS)

Skvortsova, K.V.; Sychev, I.V.; Modnikov, I.S.; Zhil'tsova, I.G.

1980-01-01

Formation conditions of regenerated uranium blacks in the zone of incomplete oxidation and cementation of uranium-molybdenum deposit have been studied. Mixed and regenerated blacks were differed from residual ones by the method of determining excess quantity of lead isotope (Pb 206 ) in ores. Determined were the most favourable conditions for formation of regenerated uranium blacks: sheets of brittle and permeable volcanic rocks characterized by heterogeneous structure of a section, by considerable development of gentle interlayer strippings and zones of hydrothermal alteration; predominance of reduction conditions in a media over oxidation ones under limited oxygen access and other oxidating agents; the composition of hypogenic ores characterized by optimum correlations of uranium minerals, sulfides and carbonates affecting violations of pH in oxidating solutions in the range of 5-6; the initial composition of ground water resulting from climatic conditions of the region and the composition of ore-bearing strata and others. Conditions unfavourable for the formation of regenerated uranium blacks are shown

Analysis on uranium mineralization-formation condition and prospecting potential in Xidamingshan metallogenic belt

International Nuclear Information System (INIS)

Li Zhixing; Qi Fucheng; He Zhongbo; Zhang Zilong

2012-01-01

There are many different opinions about the source of uranium and metallogenic mechanism in Xidamingshan metallogenic belt. therefore it blocked uranium resources potential evaluation and ore exploration. Through absorb in- formation and investigate Daxin deposit and systematic analysis on samples. It is believed that uranium source mainly came from Cambrian System, a little came from the deep. The Devonian System is favorable room for saving ores in addition to be pre-concentrated room for uranium. Also, there are new cognition about uranium metallogenic mechanism, establish ore-forming series of Xidamingshan metallogenic belt, It is proposed that uranium mineralization have experienced 4 stages; It is cleared that hydrothermal fluid superposition transform type uranium deposit is main genetic type, ancient karst accumulate type is secondary genetic type, the later is formed by leaching the former and then precipitate, enrichment in ancient karst congeries, which is formed nearby faults and with the movement of Xishan structural movement. It is proven that metallogenic potential of Xidamingshan metallogenic belt is good. Tectonic rock controlled by subsidiary fracture nearby regional main fault, which connected with the Cambrian System and the Devonian System, and the deep of the deposit is guideline of mineral prospecting next stage. (authors)

Natural radioactivity measurements and dose calculations to the public: Case of the uranium-bearing region of Poli in Cameroon

International Nuclear Information System (INIS)

Saidou; Bochud, Francois O.; Baechler, Sebastien; Moise, Kwato Njock; Merlin, Ngachin; Froidevaux, Pascal

2011-01-01

The objective of this work is to carry out a baseline study of the uranium-bearing region of Poli in which lies the uranium deposit of Kitongo, prior to its impending exploitation. This study required sampling soil, water and foodstuffs representative of the radioactivity exposure and food consumption patterns of the population of Poli. After sampling and radioactivity measurements were taken, our results indicated that the activities of natural series in soil and water samples are low. However, high levels of 210 Po and 210 Pb in foodstuffs (vegetables) were discovered and elevated activities of 40 K were observed in some soil samples. All components of the total dose were assessed and lead to an average value of 5.2 mSv/year, slightly higher than the average worldwide value of 2.4 mSv/year. Most of this dose is attributable to the ingestion dose caused by the high levels of 210 Po and 210 Pb contained in vegetables, food items which constitute an important part of the diet in Northern Cameroon. Consequently, bringing uranium ore from underground to the surface might lead to an increased dose for the population of Poli through a higher deposition of 222 Rn decay products on leafy vegetables.

In situ mobility of uranium in the presence of nitrate following sulfate-reducing conditions.

Science.gov (United States)

Paradis, Charles J; Jagadamma, Sindhu; Watson, David B; McKay, Larry D; Hazen, Terry C; Park, Melora; Istok, Jonathan D

2016-04-01

Reoxidation and mobilization of previously reduced and immobilized uranium by dissolved-phase oxidants poses a significant challenge for remediating uranium-contaminated groundwater. Preferential oxidation of reduced sulfur-bearing species, as opposed to reduced uranium-bearing species, has been demonstrated to limit the mobility of uranium at the laboratory scale yet field-scale investigations are lacking. In this study, the mobility of uranium in the presence of nitrate oxidant was investigated in a shallow groundwater system after establishing conditions conducive to uranium reduction and the formation of reduced sulfur-bearing species. A series of three injections of groundwater (200 L) containing U(VI) (5 μM) and amended with ethanol (40 mM) and sulfate (20 mM) were conducted in ten test wells in order to stimulate microbial-mediated reduction of uranium and the formation of reduced sulfur-bearing species. Simultaneous push-pull tests were then conducted in triplicate well clusters to investigate the mobility of U(VI) under three conditions: 1) high nitrate (120 mM), 2) high nitrate (120 mM) with ethanol (30 mM), and 3) low nitrate (2 mM) with ethanol (30 mM). Dilution-adjusted breakthrough curves of ethanol, nitrate, nitrite, sulfate, and U(VI) suggested that nitrate reduction was predominantly coupled to the oxidation of reduced-sulfur bearing species, as opposed to the reoxidation of U(IV), under all three conditions for the duration of the 36-day tests. The amount of sulfate, but not U(VI), recovered during the push-pull tests was substantially more than injected, relative to bromide tracer, under all three conditions and further suggested that reduced sulfur-bearing species were preferentially oxidized under nitrate-reducing conditions. However, some reoxidation of U(IV) was observed under nitrate-reducing conditions and in the absence of detectable nitrate and/or nitrite. This suggested that reduced sulfur-bearing species may not be fully effective at

Health hazard evaluation determination report HE-80-71-703, Bear Creek Uranium Company, Douglas, Wyoming

International Nuclear Information System (INIS)

Gunter, B.J.

1980-06-01

An environmental survey was conducted in February 1980 to evaluate exposure to CRC, a cleaning solvent containing perchloroethylene (127184), (PCE) and 1,1,1-trichloroethane (71556) (TCE) at Bear Creek Uranium Company (SIC-1094) in Wyoming. The survey was requested by the company safety engineer. Breathing zone and general room air samples were collected and analyzed. One mine electrician was exposed to 6,500 milligrams per cubic meter (mg/cu m) (PCE recommended OSHA limit is 690mg/cu m). Of the 7 samples of TCE, none exceeded the OSHA standard of 1900mg/cu m. Overexposure did occur when workers used the solvent in confined areas. The authors concluded that a health hazard existed when the solvent was used on confined spaces, and they recommend improved work practices

Application of Rock-Eval pyrolysis to the detection of hydrocarbon property in sandstone-type uranium deposits

International Nuclear Information System (INIS)

Sun Ye; Li Ziying; Guo Qingyin; Xiao Xinjian

2006-01-01

Rock-Eval pyrolysis is introduced into the research of uranium geology by means of oil-gas geochemical evaluation. Hydrocarbon (oil-gas) components in DS sandstone-type uranium deposit are detected quantitatively. Through analyzing the oil-gas bearing categories of the uranium-bearing sandstones, the internal relationships between the uranium deposit and the oil-gas are revealed. Rock-Eval pyrolysis is an effective method to study the interaction between inorganic and organic matters, and should be extended to the study of sandstone-type uranium deposits. (authors)

Characterization of uranium- and plutonium-contaminated soils by electron microscopy

International Nuclear Information System (INIS)

Buck, E.C.; Dietz, N.L.; Fortner, J.A.; Bates, J.K.; Brown, N.R.

1995-01-01

Electron beam techniques have been used to characterize uranium-contaminated soils from the Fernald Site in Ohio, and also plutonium-bearing 'hot particles, from Johnston Island in the Pacific Ocean. By examining Fernald samples that had undergone chemical leaching it was possible to observe the effect the treatment had on specific uranium-bearing phases. The technique of Heap leaching, using carbonate solution, was found to be the most successful in removing uranium from Fernald soils, the Heap process allows aeration, which facilitates the oxidation of uraninite. However, another refractory uranium(IV) phase, uranium metaphosphate, was not removed or affected by any soil-washing process. Examination of ''hot particles'' from Johnston Island revealed that plutonium and uranium were present in 50--200 nm particles, both amorphous and crystalline, within a partially amorphous aluminum oxide matrix. The aluminum oxide is believed to have undergone a crystalline-to-amorphous transition caused by alpha-particle bombardment during the decay of the plutonium

Uranium purchasers reassert their influence

International Nuclear Information System (INIS)

Braatz, U.

1976-01-01

The growing uranium requirement in the Western world in the long run can be met only by a participation of the electricity generating industry and the governments of the participating countries in the development costs of new deposits, according to statements by leading representatives of the uranium producers and consumers at a symposium organized by the Uranium Institute in the summer of 1976. On the other hand, the uranium market is likely to get under more and more pressure because of the delays in nuclear power programs worldwide. It is probable that the price of uranium will soon have reached its peak for a long time to come. Uranium producers also will have to bear in mind that a price policy which makes the use of uranium unattractive compared with other sources of energy could well result in a situation in which the largest uranium consumers would build more conventional thermal power stations to bridge the time to commercial introduction of fast breeder reactors. (orig.) [de

Mortality (1968-2008) in a French cohort of uranium enrichment workers potentially exposed to rapidly soluble uranium compounds.

Science.gov (United States)

Zhivin, Sergey; Guseva Canu, Irina; Samson, Eric; Laurent, Olivier; Grellier, James; Collomb, Philippe; Zablotska, Lydia B; Laurier, Dominique

2016-03-01

Until recently, enrichment of uranium for civil and military purposes in France was carried out by gaseous diffusion using rapidly soluble uranium compounds. We analysed the relationship between exposure to soluble uranium compounds and exposure to external γ-radiation and mortality in a cohort of 4688 French uranium enrichment workers who were employed between 1964 and 2006. Data on individual annual exposure to radiological and non-radiological hazards were collected for workers of the AREVA NC, CEA and Eurodif uranium enrichment plants from job-exposure matrixes and external dosimetry records, differentiating between natural, enriched and depleted uranium. Cause-specific mortality was compared with the French general population via standardised mortality ratios (SMR), and was analysed via Poisson regression using log-linear and linear excess relative risk models. Over the period of follow-up, 131 161 person-years at risk were accrued and 21% of the subjects had died. A strong healthy worker effect was observed: all causes SMR=0.69, 95% CI 0.65 to 0.74. SMR for pleural cancer was significantly increased (2.3, 95% CI 1.06 to 4.4), but was only based on nine cases. Internal uranium and external γ-radiation exposures were not significantly associated with any cause of mortality. This is the first study of French uranium enrichment workers. Although limited in statistical power, further follow-up of this cohort, estimation of internal uranium doses and pooling with similar cohorts should elucidate potential risks associated with exposure to soluble uranium compounds. 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/

Concentration factors of uranium mineralization in VII depositional cycle of Shuixigou group, lower-middle Jurassic at Wukurqi uranium deposit, Yili basin

International Nuclear Information System (INIS)

Liu Taoyong

2004-01-01

Starting with the analysis on uranium mineralization, this paper emphatically discusses factors related to uranium concentration in VII depositional cycle, such as the structure, the paleoclimate, the lithofacies-paleogeography, the lithology, the hydrogeology, the geochemistry, and the content of effective reductant. The author suggests that key factors of uranium migration and concentration at Wukurqi uranium deposit are the existence of ore-hosting formation (sand body), the long-term recharge of oxygen and uranium-bearing groundwater, the existence of effective reductant in ore-hosting formation

Physico-chemical and radiological characterization of uranium tailings from Tummalapalle uranium mining site

International Nuclear Information System (INIS)

Patra, A.C.; Sahoo, S.K.; Lenka, P.; Gupta, Anil; Jha, S.K.; Tripathi, R.M.; Molla, S.; Rana, B.K.

2018-01-01

Mining of uranium bearing minerals is essential for the extraction of uranium to meet the power requirements of India. Mining and milling activities produce large quantities of low active tailings, as wastes, which are contained in Tailings Ponds. The nature of tailings depends on the mineralogy of ore and host rock and their quantity depends on the configuration of the ore body and mining methods. The mobility of an element from these tailings depends on elemental concentration, pH, particle size, cation exchange capacity, bulk density and porosity of the tailings etc. This necessitates complete characterisation of the tailings. In this paper we aim to characterize the uranium mill tailings generated from Tummalapalle uranium mining facility in Kadappa district, Andhra Pradesh, India

Zircon U-Pb geochronology and geochemistry of granites in the Zhuguangshan complex, South China: Implications for uranium mineralization

Science.gov (United States)

Zhang, Long; Chen, Zhenyu; Li, Xiaofeng; Li, Shengrong; Santosh, M.; Huang, Guolong

2018-05-01

The Zhuguangshan complex, composed of Caledonian, Indosinian, and Yanshanian granites, and Cretaceous mafic dykes, is one of the most important granite-hosted uranium producers in South China. Here we present LA-ICP-MS zircon U-Pb and hornblende 40Ar/39Ar geochronology and whole-rock and biotite geochemistry for the granites in this complex to evaluate the magmatism and its constraints on uranium mineralization. Samples collected from the Fuxi, Youdong, Longhuashan, Chikeng, Qiling, and Sanjiangkou intrusions yield zircon weighted 206Pb/238U ages of 426.7 ± 5.4 Ma, 226.4 ± 3.5 Ma, 225.0 ± 2.7 Ma, 152.2 ± 3.0 Ma, 153.9 ± 2.1 Ma, and 155.2 ± 2.1 Ma, respectively. A new Ar-Ar dating of the hornblende of the diabase from the Changjiang uranium ore field yields a plateau age of 145.1 ± 1.5 Ma. These results coupled with published geochronological data indicate that six major magmatic events occurred in the study area at 420-435 Ma, 225-240 Ma, 150-165 Ma, 140 Ma, 105 Ma, and 90 Ma. Both U-bearing and barren granites occur in this complex, and they display differences in whole-rock and biotite geochemistry. The barren granites show higher Al2O3, CaO, TFMM, Rb, Zr, Ba, SI, Mg#, (La/Yb)N, and Eu/Eu*, but lower SiO2, ALK, Rb, DI, Rb/Sr, and TiO2/MgO than those of the U-bearing granites. Biotites in the U-bearing granites are close to the Fe-rich siderophyllite-annite end member with Fe/(Fe + Mg) ratios higher than 0.66, whereas those in the barren granites are relatively close to the Mg-rich eastonite-phlogopite end member with Fe/(Fe + Mg) ratios uranium ore potential of the granites in the Zhuguangshan complex. The geochemical variations of U-bearing and barren granites can serve as a potential detector for granite-hosted uranium deposits.

Surficial uranium occurrences in relation to climate and physical setting

International Nuclear Information System (INIS)

Carlisle, D.

1984-01-01

Important surficial chemogenic uranium deposits develop within 1) calcretes, 2) simple evaporative environments and 3) bogs or similar organic environments (''young'' uranium). Calcrete occurrences are the largest, most novel and most dependent upon extreme aridity and geomorphic stability. Economic calcrete deposits are nonpedogenic, resulting from near-surface groundwater transport and lateral concentration of uranium, vanadium, potassium, calcium, and magnesium rather than from ordinary soil-forming processes. Their genesis is essentially observable in Western Australia where carnotite-bearing nonpedogenic calcrete is currently forming under a unique aridic soil moisture regime and where major deposits have formed under similar climates during the last few thousand years. Rainfall is less than 250mm annually, only 1/12 to 1/20 of potential evaporation and concentrated almost entirely in episodic late summer storms. Outside this region, under less arid conditions, only pedogenic calcretes form and they do not contain economic uranium. In southern Africa, calcrete and gypcrete uranium deposits, although Late Tertiary to Quaternary in age, are also nonpedogenic and appear to have formed under similar climatic constraints with local variations in geomorphology and calcrete morphology. (author)

International Uranium Resources Evaluation Project (IUREP) national favourability studies: Canada

International Nuclear Information System (INIS)

1977-08-01

Exploration for mineral deposits in Canada resulted in the discovery of large uranium deposits, such as at Great. Bear Lake, Northwest Territories (1930), in the Elliot Lake area, Ontario (1949); Beaverlodge, Wollaston Lake Fold Belt and Carswell Structure in Saskatchewan (1946-1975) and many uranium occurrences in the Canadian Shield, in the Orogenic Belts and in the Platforms. Uranium output in Canada since 1942 until and including 1976 amounted to 112,000 tonnes U. Reasonably Assured uranium resources as of 1976 amounted to 167,000 tonnes U (at a price up to $40/lb. U 3 0 8 ) and 15,000 tonnes U (at a price more than $40 up to $60/lb. U 3 O 8 ). Estimated Additional uranium resources as of 1976 amounted to 392,000 tonnes U (at a price up to $40/lb. U-Og) and 264,000 tonnes U (at a price more than $40 up to $60/lb. U 3 0 8 ). Possible further potential beyond the above mentioned classes is tentatively estimated to be in the 6th category according to NEA/IAEA favourability classification. (author)

Uranium and the generation of power - the South African perspective

International Nuclear Information System (INIS)

Von Backstrom, J.W.

1975-01-01

The author examines uranium requirements, uranium production capacity and uranium reserves in the light of estimated energy forecasts for South Africa and the western world. The impact of breeder reactors, plutonium and uranium enrichment is also considered. He then deals with the South African uranium situation and the exploration that is currently under way, and makes some recommendations. These are followed by a list of characteristics and criteria that have a bearing on uranium mineralisation in various formations in South Africa

Geology and potential of the formation of sandstone type uranium mineralization at Hatapang region, North Sumatera

International Nuclear Information System (INIS)

Ngadenin

2013-01-01

The Study based on geological setting of Hatapang region, North Sumatera, identified as a favourable area to the formation of sandstone type uranium mineralization. This characterized by the occurred of anomalous radioactivity, uranium contents of the upper cretaceous granite intrusions and radioactivity anomalous of tertiary sedimentary rocks deposited in terrestrial environments. The study is objective to find out the potential formation of sandstone type-uranium mineralization within tertiary sedimentary rocks based on data’s studies of geological, geochemical, mineralogy, radioactivity of rocks. Stratigraphy of Hatapang area of the oldest to youngest are quartz units (permian-carboniferous), sandstone units (upper Triassic), granite (upper cretaceous), conglomerate units (Lower –middle Miocene) and tuff units (Pleistocene). Hatapang’s granite is S type granite which is not only potential as source of radioactive minerals, particularly placer type monazite, but also potential as source rocks of sandstone type-uranium mineralization on lighter sedimentary rocks. Sedimentary rock of conglomerate units has potential as host rock, even though uranium did not accumulated in its rocks since the lack number of carbon as precipitant material and dissolved U"+"6 in water did not reduced into U"+"4 caused the uranium mineralization did not deposited. (author)

Radioactive equilibrium of uranium-bearing ores in some problems of applied geology; Les equilibres radioactifs des menerais uraniferes dans quelques problemes de geologie appliquee

Energy Technology Data Exchange (ETDEWEB)

Coulomb, R; Girard, Ph; Goldsztein, M [Commissariat a l' Energie Atomique, Fontenay-aux-Roses (France). Centre d' Etudes Nucleaires

1964-07-01

The state of equilibrium between several nuclides in radioactive relationship is determined with accuracy by the fundamental equations of radioactivity. It can be measured physically and expressed in suitable and internationally adopted units; Equilibrium - disequilibrium of uranium-bearing ores is a fairly complex phenomenon but the problem can be much simplified by well-chosen approximations in various practical field cases. The results of radiometric and radiochemical measurements lead to the interpretation of geochemical anomalies and may be used in the qualitative and quantitative estimation of uranium bearing deposits. (authors) [French] L'etat d'equilibre entre plusieurs radioelements en filiation se definit avec precision par les equations fondamentales de la radioactivite et peut etre determine par des mesures physiques dans des systemes d'unites commodes et internationalement adoptes. Le probleme general equilibre-desequilibre des minerais uraniferes est relativement complexe, mais peut se simplifier largement par des approximations judicieuses dans de nombreux cas particuliers rencontres concretement sur le terrain. Les resultats des mesures radiometriques et radiochimiques permettent l'interpretation des anomalies geochimiques et peuvent servir a l'estimation qualitative et quantitative des gisements de minerais uraniferes. (auteurs)

Uranium

International Nuclear Information System (INIS)

Poty, B.; Cuney, M.; Bruneton, P.; Virlogeux, D.; Capus, G.

2010-01-01

concentration in peat bogs, deposits combined with marine phosphates, with coal and lignite, with black shales, with carbonate rocks, deposits in Precambrian quartz pebble conglomerates, basal-type deposits, deposits in sandstones (tabular, roll-type and tectono-lithologic deposits), breccia chimney filling deposits, deposits in metamorphic rocks, metasomatic deposits, deposits in intrusive rocks, deposits associated with hematite breccia complexes, deposits in granitic rocks, deposits in volcanic rocks, deposits in proterozoic discordances (Athabasca basin, Pine Creek geo-syncline); 4 - French uranium bearing areas and deposits: history of the French uranium mining industry, geological characteristics of French deposits (black shales, sandstones, granites), abroad success of French mining companies (Africa, North America, South America, Australia, Asia); 5 - exploration and exploitation; 6 - uranium economy: perspectives of uranium demand, present day production status, secondary resources, possible resources, market balances, prices and trends, future availability and nuclear perspectives. (J.S.)

Double-layer structure model of the uranium generating bed in the land basins of the northwestern China and its significance

International Nuclear Information System (INIS)

Wang Zhilong

1988-04-01

The paper puts forward a double layer structure model of uranium generating bed in the land basins of Northwestern China, i.e. uranium ganerating bed = source layer of uranium+gathering uranium layer. The mechanism of its formation: Feldspar was hydromicatized. Some feldspar, quarts detrital silicate minerals were replaced to redden by the authigenesis of hematite and goethite. In the course of the oxidation, a little uranium is released from the detrital minerals. Because of the oxidation environment, the released uranium wasn't able to be precipitated, only to diffuse to the adjacent grey bed which has low Eh value with uranium-bearing 'stagnant water' fixed in pores during the dewatering process of the diagenesis and form minable uranium deposit. The significance of the model for uranium prospecting are as follows: (1) Uranium source range is much expanded concerning ruanium prospecting in sandstone. (2) For the potential assessment of basin and the selection of potential area, the model is an important prospecting criterion. (3) By using the main criterion uranium-generating bed-arkosic red beds well, the buried ore bodies can be found provided that arkosic red beds were regarded as a significant criterion of uranium-generating bed

The study of distribution and forms of uranium occurrences in Lake Baikal sediments by the SSNTD method

International Nuclear Information System (INIS)

Zhmodik, S.M.; Verkhovtseva, N.V.; Soloboeva, E.V.; Mironov, A.G.; Nemirovskaya, N.A.; Ilic, R.; Khlystov, O.M.; Titov, A.T.

2005-01-01

Sediments of Lake Baikal drill cores VER-96-1 St8 TW2 (53 deg. 32 ' 15 ' 'E; 107 deg. 56 ' 25 ' 'N) (interval 181.8-235cm from the sediment surface) were studied by means of SSNTD with the aim of defining uranium occurrence in the sediments and the uranium concentration. The neutron-fission ((n,f)-autoradiographic) method allowed a detailed study of uranium distribution of these Lake Baikal sediments within the Academicheskiy Ridge. Layered accumulations of uranium-bearing grained phosphorite, uranium-bearing particles of organic material, and abnormal uranium concentration in diatomite of unknown origin were discovered

Processing of uranium-containing coal

International Nuclear Information System (INIS)

Cordero Alvarez, M.

1987-01-01

A direct storage of uranium-bearing coal requires the processing of large amounts of raw materials while lacking guarantee of troublefree process cycles. With the example of an uranium-bearing bituminous coal from Stockheim, it was aimed at the production of an uranium ore concentrate by means of mechanical, thermal and chemical investigations. Above all, amorphous pitch blende was detected as a uranium mineralization which occurs homogeneously distributed in the grain size classes of the comminuted raw material with particle diameters of a few μm and, after the combustion, enriches in the field of finest grain of the axis. Heterogeneous and solid-state reactions in the thermal decarburization above 700deg C result in the development of hardly soluble uranium oxides and and calcium uranates as well as in enclosures in mineral glass. Thus, the pre-enrichment has to take place in a temperature range below 600deg C. By means of a sorting classification of the ash at ± 2.0 mm, it is possible to achieve an enrichment of up to factor 15 for a mineral of a mainly low carbonate content and, for a mineral of a rich carbonate content, up to the factor 4. The separation of the uranium from the concentrates produced is possible with a yield of 95% by means of leaching with sulphuric acid at a temperature of 20deg C. As far as their reproducibility was concerned, the laboratory tests were verified on a semi-industrial scale. A processing method is suggested on the basis of the data obtained. (orig.) [de

Determination of uranium by controlled-potential coulometry with platinum electrode

International Nuclear Information System (INIS)

Eppis, M.R.; Adelfang, P.

1990-01-01

In this work it was investigated the process by which is possible to determine uranium by means of a controlled-potential coulometry with a platinum electrode, using a reversible method, in presence of Pu(III) or Fe(II), that permits to analyze uranium and plutonium jointly with the same work electrode. The method has been adapted to be used in a standard electrochemical cell, without any modification. The determination occurs in five stages: 1) Uranium and iron reduction, with an electrolysis at -250mV vs standard calomel electrode (S.C.E.). 2) Electrolysis at +200 mV vs S.C.E. to remove the hydrogen generated in the former stage. 3) Oxidation of U(IV) to U(VI) and Fe(II) to Fe(III) by an electrolysis at +650 mV vs S.C.E. 4) Reduction of Fe(III) to Fe(II) at +200 mV vs S.C.E. 5) A new oxidation of Fe(II) to Fe(III) at +650 mV vs S.C.E. By difference between the integrated charge in the steps 3) and 5), the integrated charge corresponding to the uranium oxidation is obtained. It was necessary to determine: a) the potential and the time that is necessary to apply to realize quantitative electrochemical reduction of uranium. b) the dependence of the U/Fe concentration ratios. c) the weight of U contained in the aliqout and its influence on the method. The accuracy and precision of the method was studied and results with a standard deviation of 0.03% was obtained. Moreover, the method presents the following advantages: a) it is possible to determine U and Pu on the same aliquot; b) the process is reversible; c) the use of mercury in glove-box is avoided. (Author) [es

Hydrogeology of exogenic epigenic uranium deposits (sedimentary type) in Uzbekistan

International Nuclear Information System (INIS)

Irgashev, Yu.I.; Gavrilov, V.A.; Muslimov, B.A.

1996-01-01

Common problems of hydrogeology and geotechnology for uranium deposits (sedimentary type) in the Republic of Uzbekistan are discussed in the paper. Hydrogeology includes studies of texture of water-bearing horizons, occurrences of ore bodies in horizons, hydrochemical survey, hydrodynamics and engineering geology. Features of deposits workable by underground leaching are presented. Such terms as 'water-bearing horizon', 'efficiency', 'water-bearing bed' are explained accounting the results of 30 year investigations conducted during prospecting, designing and exploitation of uranium deposits. Stages of hydrogeological survey are listed and features of each of them are described. Importance of geotechnology for a deposit characterization is shown. (author). 6 refs.; 1 fig.; 1 tab

Potential impacts of offshore oil spills on polar bears in the Chukchi Sea.

Science.gov (United States)

Wilson, Ryan R; Perham, Craig; French-McCay, Deborah P; Balouskus, Richard

2018-04-01

Sea ice decline is anticipated to increase human access to the Arctic Ocean allowing for offshore oil and gas development in once inaccessible areas. Given the potential negative consequences of an oil spill on marine wildlife populations in the Arctic, it is important to understand the magnitude of impact a large spill could have on wildlife to inform response planning efforts. In this study we simulated oil spills that released 25,000 barrels of oil for 30 days in autumn originating from two sites in the Chukchi Sea (one in Russia and one in the U.S.) and tracked the distribution of oil for 76 days. We then determined the potential impact such a spill might have on polar bears (Ursus maritimus) and their habitat by overlapping spills with maps of polar bear habitat and movement trajectories. Only a small proportion (1-10%) of high-value polar bear sea ice habitat was directly affected by oil sufficient to impact bears. However, 27-38% of polar bears in the region were potentially exposed to oil. Oil consistently had the highest probability of reaching Wrangel and Herald islands, important areas of denning and summer terrestrial habitat. Oil did not reach polar bears until approximately 3 weeks after the spills. Our study found the potential for significant impacts to polar bears under a worst case discharge scenario, but suggests that there is a window of time where effective containment efforts could minimize exposure to bears. Our study provides a framework for wildlife managers and planners to assess the level of response that would be required to treat exposed wildlife and where spill response equipment might be best stationed. While the size of spill we simulated has a low probability of occurring, it provides an upper limit for planners to consider when crafting response plans. Published by Elsevier Ltd.

Ore controlling oxidized zonation epigenetic uranium-coal deposits and regularities in lignite transformations

International Nuclear Information System (INIS)

Uspenskij, V.A.; Kulakova, Ya.M.

1982-01-01

Complex of analytical methods was used to study epigenetic transformations in uranium-coal ore manifestation. To clarify the principle scheme of oxidized zonation in coals the materials, related to three similar objects were used. When comparing obtained epigenetic column with columns of similar ore objects the principle scheme of oxidized epigenetic zonation for ancient infiltration uranium-coal deposits was specified; general regularities of eignite transformations and characteristics of profile distribution of uranium and accessory metal zonations were revealed. Infiltration processes, proceeded in coal measureses, formed the steady epigenetic oxidized zonation: O - zone of barren unoxidized coals, 1 - zone of ore-bearing unoxidized coals, 2 - zone of weakly ore-bearing oxidized coals, 3 - zone of oxidized terrigenous rocks with zonules of development of yellow and red iron hydroxides. Capacities of some zones and zonules reflect the intensity and duration of ore-forming processes. Distribution of U and accessory elements obeys completely epigenetic zonation. It is assumed, that ancient infiltration uranium-coal deposits formed due to weakly uranium-bearing oxygen-containing waters

Pressure leaching of uranium-bearing Witwatersrand ores

International Nuclear Information System (INIS)

Bovey, H.J.; Stewart, L.N.

1979-01-01

Since 1955 extensive pressure-leaching testwork has been conducted by Anglo American Research Laboratories (AARL) in laboratory-scale batch autoclaves. In 1958 a small continuous pilot-plant of 45 kg of solids per hour was operated by AARL. In 1974, when high uranium prices were anticipated, Anglo American, encouraged by successful commercial-scale autoclave operations as practised by Outokumpu, Sherritt Gordon, and Impala Platinium, decided to install a continuous pilot plant at Western Deep Levels. At that time the proposed pilot plant was considered to be of prototype size. The project was funded by members of the Nuclear Fuels Corporation (Nufcor). Since its commissioning in February 1977, the pilot plant at Western Deep Levels, which can treat between 10 and 20 tons of dry solids per hour, has been used to test ores from four different mines. The paper compares the uranium extractions and pyrite oxidation obtained in laboratory batch autoclaves with those obtained in the continuous pilot plant. In general, differences in uranium extraction are not great and can be explained; the differences in pyrite oxidation are less well understood. The effect on plant design of the evolution of carbon dioxide during leaching is discussed. Evaluation of the equipment and materials of construction would have been almost impossible in a small-scale batch autoclave. It is doubtful whether such results would have generated the necessary confidence to permit decisions to install a commercial-size plant. The development and performance of the multistage pumps, instrumention, shaft seals and shaft-seal water treatment are discussed. It is concluded that the operation of a large-scale continuous pressure-leaching pilot plant to supplement laboratory batch autoclave tests has been a necessary part of the development of this process [af

Aeromagnetic data processing and application in the evaluation of uranium resource potential in China

International Nuclear Information System (INIS)

Wang Yuanzhi; Zhang Junwei; Feng Chunyuan

2012-01-01

The article introduces the main methods to deduce geological structures with aeromagnetic data, and summarizes the prediction elements of aeromagnetic characteristics for granite, volcanic, carbonaceous-siliceous-argillaceous rock and sandstone type uranium deposits. By analysing the relationship of aeromagnetic deduced geological structures and uranium mineralization, the prediction model of combined factors was summarized for each type uranium deposit. A case study in Taoshan-Zhuguang mineralization belt shows that the fault, plutons and volcanic structures deduced from areomagnetic information can judge the favorable mineralization environment and ore control structure. Therefore, the process and application of aeromagnetic data can play an important role in the evaluation of uranium resource potential and uranium exploration. (authors)

Aspects of the sedimentology of some uranium-bearing sandstones in the Beaufort West area, Cape Province

International Nuclear Information System (INIS)

Cole, D.I.

1980-01-01

The sedimentology of some uranium-bearing sandstones from the Beaufort Group in the Beaufort West area was studied by use of some 116 vertical profiles measured across and adjacent to 14 mineralized deposits. The vertical profiles consist of 91 field sections and 25 borehole logs. The sandstones are usually multistorey and alternate with a mudstone and/or siltstone succession. The vertical profiles basically consist of a succession of facies. Some 19 facies were recognised within the sandstones on the basis of texture and sedimentary structure. The facies transitions within the sandstone sequence were subjected to a one-step Markov chain analysis. The cumulative thickness of uranium mineralization for each sedimentary facies within the sandstone sequence was measured. Some 99 per cent of the total cumulative thickness occurs within the coarser-grained facies (grain sizes in excess of very fine), which suggests that permeability was an important control on the mineralization. The coarser-grained facies, which mostly represent lower point bar or channel bar deposits near the base of each storey, probably acted as suitable aquifers for the transport of uraniferous solutions. Irregularities in the base of each storey may have interrupted the flow of these solutions and allowed sufficient time for precipitation of the uranium. Carbonaceous debris is frequently associated with the mineralized deposits and most likely acted as an indirect reductant for this precipitation. Mineralization decreases upwards in the sandstone sequence and some 40 per cent of the total cumulative thickness is restricted to the initial storey. The horizontally bedded facies contain a high proportion of the total cumulative thickness of mineralization (45 per cent) and this again may be related to a more abundant content of carbonaceous debris

Radiation pathways and potential health impacts from inactive uranium mill tailings

International Nuclear Information System (INIS)

1978-07-01

Radiation exposure pathways and potential health impacts were estimated as part of the evaluation of radioactive uranium mill tailings at the sites of inactive mills in eight western states. The purpose of this report is to describe in detail the methodology used in performing the pathway analysis and health effects estimations. In addition, specific parameters are presented for each of the 22 uranium mill sites that were evaluated. A computer program, RADAD, developed as part of this program, is described and listed

Vein-type uranium deposits

International Nuclear Information System (INIS)

Rich, R.A.; Holland, H.D.; Petersen, U.

1975-01-01

A critical review is presented of published data bearing on the mineralogy, paragenesis, geochemistry, and origin of veiw-type uranium deposits. Its aim is to serve as a starting point for new research and as a basis for the development of new exploration strategies. During the formation of both vein and sandstone types of deposits uranium seems to have been dissolved by and transported in rather oxidized solutions, and deposited where these solutions encountered reducing agents such as carbon, sulfides, ferrous minerals and hydrocarbons. Granitic rocks abnormally enriched in uranium have apparently been the most common source for uranium in vein-type deposits. Oxidizing solutions have been derived either from the surface or from depth. Surface solutions saturated with atmospheric oxygen have frequently passed through red bed or clean sandstone conduits on their way to and from uranium source rocks. Deep solutions of non-surface origin have apparently become sufficiently oxidizing by passage through and equilibration with red beds. The common association of clean sandstones or red beds with uranium-rich granites in the vicinity of vein-type uranium deposits is probably not fortuitous, and areas where these rock types are found together are considered particularly favorable targets for uranium exploration

Geological, radiometrical, and geochemical studies of Banggai granites and Bobong formation to determine potential Uranium area in Taliabu Island, North Maluku

International Nuclear Information System (INIS)

Ngadenin

2016-01-01

Geological, radiometrical, and geochemical studies of Banggai granites and Bobong Formation have been conducted in order to obtain potential uranium area. Taliabu Island is selected for the study because Taliabu Island is a micro continent fraction of the Gondwana super continent that separated at the end of the Mesozoic to Paleogene period. Some types of uranium mineralization formed in the period of Gondwana include sandstone-type, lignite coal type, and vein-type. Taliabu Island is a small part from the Gondwana super continent so it is expected will be found uranium mineralization or at least indications of uranium mineralization occurrences. The aim of this study is to obtain uranium potential areas for the development of uranium exploration in the future. The methods used are reviewing geological, radiometric, and geochemical data from various sources. The results of review showed that geological setting, radiometric, and geochemical data gives positive indication to the formation of uranium mineralization for sandstone type. Banggai granite is a potential uranium source. Sandstone of Bobong Formation as a potential host rock. Coal and pyrite as a potential precipitant. Uranium potential area is located on Bobong Formation and its surrounding. (author)

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Sandstone-type uranium deposits

International Nuclear Information System (INIS)

Austin, S.R.; D'Andrea, R.F. Jr.

1978-01-01

Three overall factors are necessary for formation of uranium deposits in sandstone: a source of uranium, host rocks capable of transmitting uranium-bearing solutions, and a precipitant. Possible sources of uranium in sandstone-type deposits include groundwaters emanating from granitic highlands, arkosic sediments, tuffaceous material within or overlying the host rocks, connate fluids, and overlying black shales. The first three sources are considered the most likely. Host rocks are generally immature sandstones deposited in alluvial-fan, intermontane-basin or marginal-marine environments, but uranium deposits do occur in well-winnowed barrier-bar or eolian sands. Host rocks for uranium deposits generally show coefficients of permeability on the order of 1 to 100 gal/day/ft 2 . Precipitants are normally agents capable of reducing uranium from the uranyl to the uranous state. The association of uranium with organic matter is unequivocal; H 2 S, a powerful reductant, may have been present at the time of formation of some deposits but may go unnoticed today. Vanadium can serve to preserve the tabular characteristics of some deposits in the near-surface environment, but is considered an unlikely primary precipitant for uranium. Uranium deposits in sandstone are divided into two overall types: peneconcordant deposits, which occur in locally reducing environments in otherwise oxidized sandstones; and roll-type deposits, which occur at the margin of an area where an oxidized groundwater has permeated an otherwise reduced sandstone. Uranium deposits are further broken down into four subclasses; these are described

Potential for Methanosarcina to contribute to uranium reduction during acetate-promoted groundwater bioremediation

DEFF Research Database (Denmark)

Holmes, Dawn E; Orellana, Roberto; Giloteaux, Ludovic

2017-01-01

Previous studies of in situ bioremediation of uranium-contaminated groundwater with acetate injections have focused on the role of Geobacter species in U(VI) reduction because of a lack of other abundant known U(VI)-reducing microorganisms. Monitoring the levels of methyl CoM reductase subunit...... an important role in the long-term bioremediation of uranium-contaminated aquifers after depletion of Fe(III) oxides limits the growth of Geobacter species. The results also suggest that Methanosarcina have the potential to influence uranium geochemistry in a diversity of anaerobic sedimentary environments....

Systems and economics for the estimation of uranium potential supply

International Nuclear Information System (INIS)

Harris, D.P.; Ortiz-Vertiz, R.; Chavex, M.L.; Agbolosoo, E.K.

1981-07-01

This report consists of four parts, each one reasonably complete unto itself: Part I - Potential Supply Systems Based upon the Simulation of Sequential Exploration and Economic Decisions -- Systems Designed for the Analysis of NURE Endowment; Part II - Crustal Abundance and a Potential Supply System; Part III - An Investigation of Productivity and Technical Change in Exploration for and Production of Uranium; and Part IV - The Use of Solute Transport Models to Generate Geochemical Responses from a Hypothetical Uranium Deposit - An Early Effort in the Exploration Model Design. The bulk of this research was devoted to the design of potential supply systems. However, in that such systems require the modeling of exploration and exploitation, both of these activities were investigated as economic phenomena and as the subjects of models. Part I represents the largest of the research efforts. An attempt was made to design a system in which exploration is modeled in terms of both its efficiency and economics. While the exploration model demonstrated in this report is for roll-type sandstone deposits, this potential supply system, as a system per se, also applies to tabular deposits (San Juan Basin). Part II explores the concept of crustal abundance and existing crustal abundance models. The design of this crustal abundance potential supply system differs from that of any previously constructedcrustal abundance models in that it explicitly considers the third dimension, depth to deposit, and it places great emphasis upon the credible representation of the economics of exploration and exploitation. Part III reports on an attempt to measure the magnitude of technical change and depletion on the productivity of exploration and mining. This research examined these issues from the perspective of the economist, not the engineer. Part IV reports on an investigation of the feasibility of modeling the geochemical exploration for uranium, radon, and helium plumes

Uranium Potential and Socio-Political Environment for Uranium Mining in the Eastern United States Of America with Emphasis on the Coles Hill Uranium Deposit

Energy Technology Data Exchange (ETDEWEB)

Reynolds, N.W., E-mail: MMastilovic@vaunic.com [Virginia Uranium, Inc., Chatham, VA (United States)

2014-05-15

Virginia Uranium, Inc. (“VUI”) is an exploration and development company that holds exclusive rights to the world class Coles Hill uranium project in Pittsylvania County, Virginia. This project has the potential to supply significant uranium to the market. Since the 1980s over US$60 million has been expended to advance the project. The Coles Hill uranium deposit is located in south central Virginia and is probably the largest undeveloped uranium deposit in the United States. It has a measured and indicated resource of 119 million pounds of U{sub 3}O{sub 8}{sup (A)} {sup (B)} at a cut-off grade of 0.025% U{sub 3}O{sub 8} based on a National Instrument 43-101 technical report prepared for Santoy Resources Ltd. and Virginia Uranium, Inc. by Behre Dolbear and Company, Ltd., Marshall Miller and Associates, Inc., and PAC Geological Consulting Inc. dated February 2, 2009 and revised April, 2009. The whole rock analyses of the deposit indicate a relatively monomineralic ore that does not contain quantities of heavy metals that are typical of uranium ores of the southwestern United States. The Colorado School of Mines Research Institute conducted mill mineral processing tests in the 1980s. Project pre-feasibility studies and other plans completed in the 1980s will be updated over the next 12 months.Mining and support personnel can reasonably be recruited from the local area, as the skill sets needed for miners exist already among people and companies who are comfortable with farming and heavy equipment. Virginia currently requires that uranium mining regulations and permitting be adopted by law prior to approving a mining operation at Coles Hill. Virginia has regulated and permitted many similar mining industries. In fact, lead has been mined in the state from 1750–1981 and heavy metal sands have been mined since 1991 in Dinwiddie County that is over 90 miles/144 kilometers east of Coles Hill. A process to evaluate uranium mining through the Virginia Coal and Energy

Gravity data processing and research in potential evaluation of uranium resource in China

International Nuclear Information System (INIS)

Liu Hu; Zhao Dan; Ke Dan; Li Bihong; Han Shaoyang

2012-01-01

Through data processing, anomaly extraction, geologic structure deduction from gravity in 39 uranium metallogenic zones and 29 prediction areas, the predicting factors such as tectonic units, faults, scope and depth of rocks, scope of basins and strata structure were provided for the evaluation of uranium resources potential. Gravity field features of uranium metallogenic environment were summarized for hydrothermal type uranium deposits (granite, volcanic and carbonate-siliceous-argillaceous type) as regional gravity transition from high to the low field or the region near the low field, and the key metallogenic factors as granite rocks and volcanic basins in the low gravity field. It was found that Large-scale sandstone type uranium mineralization basins are located in the high regional gravity field, provenance areas are in the low field, and the edge and inner uplift areas usually located in the high field of the residual gravity. Faults related to different type uranium mineralization occur as the gradient zones, boundaries, a string of bead anomalies and striped gravity anomalies in the gravity field. (authors)

Potential health and environmental hazards of uranium mine wastes. Volume 3. Appendixes. Report to the congress

International Nuclear Information System (INIS)

1983-01-01

Contents include: summary of federal laws potentially affecting uranium mining; federal water programs and right activities; congressionally approved compacts that apportion water; state laws, regulations, and guides for uranium mining; active uranium mines in the United States; inactive uranium mines in the United States; general observations of uranium mine sites in Colorado, New Mexico, Texas, and Wyoming; influence of mine drainage on seepage to groundwater and surface water outflow; computation of mass emission factors for wind erosion; aquatic dosimetry and health effects models and parameter values; Airborne pathway modeling; and health risk assessment methodology

The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of Western Qinling

International Nuclear Information System (INIS)

Qian Farong; Zhou Dean; Ji Hongfang

1995-11-01

The siliceous-calcareous-argillaceous rock type uranium deposit in south subzone of western Qinling is an inland found type deposit with specific mineralization and good potentiality. The mineralization distributes along definite horizons and occurs in siliceous layer and lenses of siliceous-calcareous rocks. Orebody presents in forms of stratoid, lenticular and irregular veins and controlled by factorial structures. Ore is identified as massive and sandy and each characterized by various mineral compositions and element associations. The study shows that the mineralizing materials are mainly derived from ore-bearing strata. The metallogenic environment has characteristics of middle-low temperature and supergene The metallogenesis underwent three stages: (1) Sedimentation-diagenesis of the ore-bearing strata led to preliminary concentration of uranium; (2) Polytectonic activities accompanied by underground hydrothermal process resulted in the industrial concentration of uranium; and (3) Orebody reworked by oxidation-denudation and leaching, locally has taken place secondary concentration. The deposit in origin attributes to polygenesis dominated by underground hydrothermal metallogenesis. Main metallogenic epoch happens during the periods of Late Yanshan and Himalayan. According to the geological-tectonic conditions the further prospecting direction in study area is proposed. (3 refs., 5 figs., 9 tabs.)

Uranium production in Sweden

International Nuclear Information System (INIS)

Bergh, S.

1994-01-01

The history of uranium production in Sweden is reviewed in the article. The World War II led to an exploitation of the Swedish alum shale on a large scale. In the last phase of the war it also became obvious that the shale might be used for energy production of quite another kind than oil. In 1947 AB Atom energy was founded, an enterprise with one of its purposes to extract uranium for peaceful use. A plant with a yearly capacity of 120 tons of uranium was erected at Ranstad and ready for production by 1965. From the start in Ranstad and for many years to come there was hardly any interest in an immediate large uranium production. It was decided to use the plant for studies on its more effective exploitation in case of an expansion in the future, bearing in mind the reactor programme. In the course of time economical reasons began to speak against the project. The shale seemed to have a future neither as oil nor as uranium resource. The complete termination of the work on uranium production from shale occurred in 1989

Uranium potential of the Central African Republic

International Nuclear Information System (INIS)

Bangoto, R.

2014-01-01

Several factors determine the long-term sustainability of nuclear power. The terms of reference of the URAM-2014 already give very valuable insights on the future of nuclear energy. The combination of all these factors plus the new ores discoveries generated by ongoing exploration efforts can satisfy nuclear power by long and sunny days. Member countries of the IAEA, such as the Central African Republic (CAR), are each called in what concerns him to invest in shares arising on these factors. The mineral potential of the CAR which is pretty well supplied with at least 470 mineral occurrences, but few are mined other than some gold and diamond enterprises that are operated by craftsmen. The weakness of its economy does not allow the CAR to undertake by itself work to highlight possible extensions of these occurrences in depth and that might constitute possible mineable deposits. Note the presence occurrences of rare earths elements among these occurrences. The uranium exploration which started since 1947 in the CAR has not yet been able to progress to allow the country to join the list of producer countries. The door for a new producer is unfortunately very narrow. Its unique sedimentary Bakouma site of uranium mineralization is known. However, the Areva Company, for internal reasons, suspended the completion of research there. Expectations are that this uranium deposit may see its beginning of extraction in the future, but it is also expected that exploration will continue in granite, pegmatite and metamorphic rocks using new exploration technologies in the framework of public-private partnership. (author)

Uranium mineralization of the Witwatersrand and Dominion Reef systems

International Nuclear Information System (INIS)

Simpson, P.R.; Bowles, J.F.W.

1977-01-01

Uranium-bearing minerals in the Witwatersrand and Dominion Reef sediments have been studied by ore microscopic, electron microprobe, fission track and neutron activation analytical methods to determine the controls of uranium mineralization. In the Dominion Reef, which represents a high-energy banket type of depositional environment, allogenic thorian uraninite occurs in hydraulic equivalence with allogenic pyrite, quartz and possibly also gold in the sediments which have uranium-thorium ratios between 3.1 and 5.6 indicating substantial amounts of thorium-rich resistate minerals. The Witwatersrand sediments have uranium-thorium ratios ranging between 7.1 and 19.6 indicating lesser amounts of resistates which is consistent with the lower-energy depositional environment. The proximal or nearshore deposits are of banket type but are distinguished from the Dominion Reef by the abundance of concretionary pyrite formed within the Basin and the presence of carbonaceous matter. The distal deposits formed at greater distance from the shoreline contain decaying organic material which has precipitated both uranium and gold from solution. Subsequent metamorphism has resulted in the formation of carbonaceous material bearing finely disseminated low-thorium pitchblende and a fine dissemination of gold associated with sulphides and arsenides. (author)

Analysis of geological condition and prospecting potential of uranium metallogenesis in Maling granite mass

International Nuclear Information System (INIS)

Shao Fei; Zou Maoqing; Wu Yong; Xu Jinshan; Xu Wang; Chen Chang

2011-01-01

Based on the study of regional geological evolution of Maling granite mass, uranium content of granite mass and its peripheric strata, petrogeochemistry and the known spatial distribution pattern of uranium mineralization and ore-controlling structures, new recognition is 1) Maling composite mass is the 'S' type re-melted granite, 2) the accumulative area of regional uranium metallogenic substances forms uranium-rich re-melted strata, 3) magma evolution is the matter base for the uranium-rich hydrotherm, 4) NE-trending main faults are channels for metallogenesis and the lateral high-angle dipping faults, fractures and interlayer fractures in the peripheric strata are the spaces of mineralization. The ore intersected by drilling in Maling granite is acidic type. Prospecting potential of Maling granite mass is analyzed, and preferable prospecting space is delineated for further exploration. (authors)

Uranium deposits in Africa

International Nuclear Information System (INIS)

Wilpolt, R.H.; Simov, S.D.

1979-01-01

Africa is not only known for its spectacular diamond, gold, copper, chromium, platinum and phosphorus deposits but also for its uranium deposits. At least two uranium provinces can be distinguished - the southern, with the equatorial sub-province; and the south Saharan province. Uranium deposits are distributed either in cratons or in mobile belts, the first of sandstone and quartz-pebble conglomerate type, while those located in mobile belts are predominantly of vein and similar (disseminated) type. Uranium deposits occur within Precambrian rocks or in younger platform sediments, but close to the exposed Precambrian basement. The Proterozoic host rocks consist of sediments, metamorphics or granitoids. In contrast to Phanerozoic continental uranium-bearing sediments, those in the Precambrian are in marginal marine facies but they do contain organic material. The geology of Africa is briefly reviewed with the emphasis on those features which might control the distribution of uranium. The evolution of the African Platform is considered as a progressive reduction of its craton area which has been affected by three major Precambrian tectonic events. A short survey on the geology of known uranium deposits is made. However, some deposits and occurrences for which little published material is available are treated in more detail. (author)

Potential for uranium recovery at Nolans

International Nuclear Information System (INIS)

Soldenhoff, K.; Ho, E.

2007-01-01

The concentration of uranium in Nolans is higher than is typical of phosphate rock deposits worldwide. This requires appropriate management of the radioactivity during ore processing, but also provides an opportunity for recovery of uranium as a by-product. The recovery must be integrated into the rare earth process, which is the primary focus of the project. Furthermore, the separation of rare earths from the phosphate matrix and the recovery of phosphoric acid or other fertiliser products is also an important consideration. This paper discusses the various process options that are being considered for the development of a process for Nolans that integrates the recovery of phosphate values and uranium as by-products or rare earth processing

Uranium mineralization environment and prospecting potential of Dawan ore field in Nanling metallogenic belt

International Nuclear Information System (INIS)

Yang Shanghai

2011-01-01

Located in the middle part of Jiuyishan complex pluton, Nanling metallogenic belt, Dawan uranium ore field in Hunan Province is an important uranium-producing and rare metal, nonferrous metal cluster area due to the favourable mineralization environment. The Cambrian is the main uranium source bed and their contact zone to the pluton is the favorable part for mineralization. The uranium deposits which have been explored are all located in the exocontact zone of Jinjiling pluton in the middle part of Jiuyishan complex pluton which is composed of the independent eastern and western magma evolution centers. In the west center, Jinjiling pluton is closely related to uranium mineralization where the trinity geologic setting was formed with magma evolution, hydrothermal fluid action and mineralization. The deep slitted and large faults provide the pathway and thermodynamic source for circulating migration of mineralizing fluid. The uranium mineralization mainly occurred in crustal stress conversion period of Late Cretaceous and related to the tensive NW extending fault and deep originated fluid. The gravity, aero magnetic, airborne gamma-ray spectrometry anomalies and radioactivity hydrochemical anomaly are important criteria for uranium prospecting. Based on the analysis of regional uranium mineralization environment, the prospecting potential is forecasted. (authors)

Technological study about a disposal measures of low-level radioactive waste including uranium and long-half-life radionuclides

International Nuclear Information System (INIS)

Sugaya, Toshikatsu; Nakatani, Takayoshi; Sakai, Akihiro; Sakamoto, Yoshiaki; Sasaki, Toshihisa; Nakamura, Yasuo

2017-02-01

Japan Atomic Energy Agency (JAEA) performed the technical studies contributed for the disposal measures of uranium-bearing waste with low concentration and intermediate depth disposal-based waste occurring from the process of the nuclear fuel cycle. (1) Study of the trench disposal of uranium-bearing waste. As a part of the study of disposal measures of the uranium-bearing waste, we carried out the safety assessment (exposure dose assessment) and derived the upper limit of radioactivity concentration of uranium which was allowed to be included in radioactive waste for trench disposal. (2) Preliminary study for the expansion of material applied to clearance in uranium-bearing waste. Currently, the clearance level of uranium handling facilities was derived from the radioactivity concentration of uranium corresponding to dose criterion about the exposure pathways of the reuse and recycle of metal. Therefore, we preliminarily evaluated whether metal and concrete were able to be applied to clearance by the method of the undergrounding disposal. (3) Study of the concentration limitation scenarios for the intermediate depth disposal-based waste. We carried out dose assessment of intermediate depth disposal of radioactive waste generated from JAEA about radioactive concentration limitation scenarios of which the concept was shown by the study team in Nuclear Regulation Authority. Based on the results, we discussed whether the waste was applied to radioactive waste conforming to concept of intermediate depth disposal. (author)

A new approach for geochemical surveys of large areas for uranium resource potential

International Nuclear Information System (INIS)

Arendt, J.W.; Butz, T.R.; Cagle, G.W.; Kane, V.E.; Nichols, C.E.

1977-01-01

The Grand Junction, Colorado office of the United States Energy Research and Development Administration (ERDA) is conducting the National Uranium Resource Evaluation Program to evaluate the uranium resources in the United States and Alaska. The program is designed to identify favorable areas for uranium exploration, to assess the supply of domestic resources, and to improve exploration technology. The Nuclear Division of the Union Carbide Corporation has been assigned the responsibility of conducting a hydrogeochemical and stream sediment survey of the mid-continental states in the United States. This survey covers approximately 2,500,000 km 2 (1,000,000 mi 2 ) and includes the states of Texas, Oklahoma, Kansas, Nebraska, South Dakota, North Dakota, Minnesota, Wisconsin, Michigan, Indiana, Illinois, and Iowa. The uranium potential of sandstones, Precambrian conglomerates, veins, granites, and phosphorites is being assessed utliizing a three-part program consisting of pilot surveys in each geological province and two phases of reconnaissance sampling of drainage basins. Samples of stream sediment, stream water, groundwater, algae, and vegetation are analyzed for uranium and some 20 additional elements. Data resulting from this program is released to private industry by ERDA as it becomes available. Analysis of results from a typical three-part survey are given. For distinctive geological regions, the pilot survey will: (1) define characteristic concentration background levels of the elements of interest, (2) identify potential uranium pathfinder elements, (3) determine relationship between stream, stream sediment and botanical samples, (4) identify any necessary modification to field sampling techniques, and (5) determine necessary sensitivities required for chemical analysis. The first reconnaissance phase average sample spacing of one station per 250 km 2 (100 mi 2 ) drainage basin is shown to delineate general boundaries of uranium provinces, and the second

Bear Creek Project. Final environmental statement

International Nuclear Information System (INIS)

1977-06-01

The Bear Creek Project consists of certain mining and milling operations involving uranium ore deposits located in Converse County, Wyoming. Mining of uranium from nine known ore bodies will take place over a period of ten years (estimated); a mill with a nominal capacity of 1000 tons per day of ore will be constructed and operated as long as ore is available. The waste material (tailings) from the mill, also produced at a rate of about 1000 tons per day, will be stored onsite in an impoundment. Environmental impacts and adverse effects are summarized

Study on integrated evaluation of sandstone-hosted uranium metallogenic potential in southern Yili basin

International Nuclear Information System (INIS)

Han Shaoyang; Ke Dan; Xu Jianguo; Zheng Enjiu; Li Shengxiang

2008-01-01

Plenty of geological data have been accumulated during mineral resource survey in China; under the guidance of new metallogenic theories, it is an important task of how to use these data most effectively for the new cycle uranium survey. In this paper, the flow of establishing the integrated mineral deposits prospecting model for sandstone-hosted uranium deposits is put forward. Based on studying geologic, hydrogeologic and regional geophysical field characteristics of representative uranium deposits No. 512 in southern Yili basin, its multi-source information descriptive model has been established, from which 512-type integrated prospecting models of sandstone-hosted uranium orefield and deposits are summarized. According to the established integrated prospecting models, the metallogenic information extraction of sandstone-hosted uranium deposits has completed in the study area. Finally, the integrated quantitative evaluation of sandstone-hosted uranium metallogenic potential is performed by using the evidence weighing method to integrate middle scale multi-source metallogenic information in the southern Yili basin, and good prediction effect is obtained. (authors)

Epidemiological study of workers at risk of internal exposure to uranium

International Nuclear Information System (INIS)

Guseva Canu, I.

2008-09-01

This work is a pilot-study among nuclear fuel cycle workers potentially exposed to alpha radiation. Internal exposure from inhalation of uranium compounds during uranium conversion and enrichment operations was estimated at the AREVA NC Pierrelatte plant. A plant specific semi-quantitative job exposure matrix (JEM) was elaborated for 2709 workers employed at this plant between 1960 and 2006. The JEM has permitted to estimate the exposure to uranium and 16 other categories of pollutants and to calculate individual cumulative exposure score. Numerous correlations were detected between uranium compounds exposure and exposure to other pollutants, such as asbestos, ceramic refractive fibers, TCE and so on. 1968-2005 mortality follow-up showed an increasing risk of mortality from pleural cancer, rectal cancer and lymphoma on the basis of national mortality rates. Analyses of association between cancer mortality and uranium exposure suggested an increase in mortality due to lung cancer among workers exposed to slowly soluble uranium compounds derived from natural and reprocessed uranium. However these results are not statistically significant and based on a small number of observed deaths. These results are concordant with previously reported results from other cohorts of workers potentially exposed to uranium. Experimental studies of biokinetic and action mechanism of slowly soluble uranium oxides bear the biological plausibility of the observed results. Influence of bias was reduced by taking into account of possible confounding including co-exposure to other carcinogenic pollutants and tobacco consumption in the study. Nevertheless, at this stage statistical power of analyses is too limited to obtain more conclusive results. This pilot study shows the interest and feasibility of an epidemiological investigation among workers at risk of internal exposure to uranium and other alpha emitters at the national level. It demonstrates the importance of exposure assessment for

U-Th-Pb systematics of some granitoids from the northeastern Yilgarn Block, Western Australia and implications for uranium source rock potential

Energy Technology Data Exchange (ETDEWEB)

Stuckless, J S; Nkomo, I T [Geological Survey, Denver, CO (USA); Bunting, J A [Geological Survey of Western Australia, Perth

1981-11-01

The Mount Boreas-type granite and spatially associated syenitic granitoid of Western Australia yield Pb-Pb ages of 2370 +- 100 Ma and 2760 +- 210 Ma, respectively. Th-Pb ages, although less precise, are concordant with these ages, and therefore the apparent ages are interpreted to be the crystallisation ages for these two units. U-Pb ages are variable and for the most part anomalously old, which suggests a Cainozoic uranium loss. However, this loss is generally small (3..mu..g/g); therefore, neither granitoid in its fresh state provides a good source for nearby calcrete-hosted uranium deposits. The possibility remains that the Mount Boreas-type granite that has been completely weathered during the Tertiary could have been a source for the calcrete-type uranium deposits in W.A. Although the Mount Boreas-type granite is highly fractionated, it does not bear a strong geochemical imprint of a sedimentary precursor. This feature contrasts it with apparently fresh granitoids from other parts of the world that have lost large amounts of uranium (approx. 20..mu..g/g) and are associated with large roll-type and other low temperature-type uranium deposits.

Kinetic and thermodynamic bases to resolve issues regarding conditioning of uranium metal fuels

International Nuclear Information System (INIS)

Johnson, A.B.; Ballinger, R.G.; Simpson, K.A.

1994-12-01

Numerous uranium - bearing fuels are corroding in fuel storage pools in several countries. At facilities where reprocessing is no longer available, dry storage is being evaluated to preclude aqueous corrosion that is ongoing. It is essential that thermodynamic and kinetic factors are accounted for in transitions of corroding uranium-bearing fuels to dry storage. This paper addresses a process that has been proposed to move Hanford N-Reactor fuel from wet storage to dry storage

Uranium in phosphorus-bearing raw materials and technological problems of its recovery

Energy Technology Data Exchange (ETDEWEB)

Gorecki, H; Gorecka, H [Politechnika Wroclawska (Poland)

1981-01-01

A problem of uranium recovery from phosphorus-bearinq raw materials is discussed. The different methods of uranium recovery from extractive phosphoric acid are briefly described. The information on their applications in the industry is also given.

Tianmujian caldera. A potential area for locating rich and large uranium deposit

International Nuclear Information System (INIS)

Lin Ziyu; Xu Jinshan; Chen Mingzhuo; Jiang Jinyuan; Fan Honghai; Cheng Qi

2001-01-01

Based on the comprehensive analysis on geologic, remote sensing, gravimetric, magnetic and geochemical data, and the field geologic investigation, the author has preliminarily ascertained the formation and the distribution characteristics of the Tianmujian caldera, and recognized the porphyroclastic lava system which is extensively distributed in the area. The authors suggest that the Tianmujian volcanic basin experienced two evolution stages--the thermal uplifting and the formation of caldera, that large concealed uranium-rich granitic massif occurs in the area, and during the vertical evolution process the uranium showed its concentration in the lower part and depletion in the upper part, and large amount of ore-forming material moved upward along with the magmatic hydrothermals entering the caldera to form uranium deposit. In addition, it is clarified that the NE-NW rhombic-formed basement structural pattern is predominated by the NE-trending fault. At the same time, the important role of the basement faults in controlling the magmatic activities, in the formation of volcanic basins, as well as the formation of uranium mineralization is emphasized. On the basis of the above comprehensive analysis the authors suggest that the Tianmujian caldera is a quite favourable potential area for possessing the basic conditions necessary for the formation of rich and large uranium deposit including uranium 'source, migration, concentration, preservation' and favourable multiple metallogenic information is displayed in the Tianmujian area

The Potential for Criticality Following Disposal of Uranium at Low-Level-Waste Facilities. Containerized Disposal

International Nuclear Information System (INIS)

Colten-Bradley, V.A.; Hopper, C.M.; Parks, C.V.; Toran, L.E.

1999-01-01

The purpose of this study was to evaluate whether or not fissile uranium in low-level-waste (LLW) facilities can be concentrated by hydrogeochemical processes to permit nuclear criticality. A team of experts in hydrology, geology, geochemistry, soil chemistry, and criticality safety was formed to develop and test some reasonable scenarios for hydrogeochemical increases in concentration of special nuclear material (SNM) and to use these scenarios to aid in evaluating the potential for nuclear criticality. The team's approach was to perform simultaneous hydrogeochemical and nuclear criticality studies to (1) identify some possible scenarios for uranium migration and concentration increase at LLW disposal facilities, (2) model groundwater transport and subsequent concentration increase via precipitation of uranium, and (3) evaluate the potential for nuclear criticality resulting from potential increase in uranium concentration over disposal limits. The analysis of SNM was restricted to 235 U in the present scope of work. The work documented in this report indicates that the potential for a criticality safety concern to arise in an LLW facility is extremely remote, but not impossible. Theoretically, conditions that lead to a potential criticality safety concern might arise. However, study of the hydrogeochemical mechanisms, the associated time frames, and the factors required for an actual criticality event indicate that proper emplacement of the SNM at the site can eliminate practical concerns relative to the occurrence and possible consequences of a criticality event

Uranium laterite from Ipora/Amorinopolis region- Goias, Brazil

International Nuclear Information System (INIS)

Fernandes, S.M.

1983-01-01

The present study gives an account of the uranium bearing laterite in the district of Amorinopolis, GO. Emphasis is given in the study of its mineralogy and of the mineralization controls. The uranium mineralization is chiefly found within the arkosic sandstones at the base of the Devonian Ponta Grossa Formation. The ore is tabular and concordant with the bedding, the controls being simultaneously litho-stratigraphic and biochemical. Narrow permeable horizons of arkosic sandstone lie between impermeable shale an siltstone layers. Within the permeable horizon fossil remains (probably brachiopods) are replaced by uranium minerals. The oxidized iron minerals may have acted to insulate and preserve the secondary soluble uranium minerals. (author)

Brief analysis on uranium metallogenic potential in Wunikeng area

International Nuclear Information System (INIS)

Wang Binghua

2010-01-01

Through the geological mapping, gamma total equivalent weight survey in Wunikeng area, the tectonics and gamma anomalies discovered in this area are analyzed, uranium metallogenic potential is analyzed by combining the regional metallogenic condition, contrasting the metallogenic geological background, massif condition, tectonic framework from these aspects of the regional geological background, massif condition on the work area, tectonic framework, etc.. (authors)

Uranium and nuclear issues

International Nuclear Information System (INIS)

1983-01-01

This seminar focussed on the major issues affecting the future of the entire nuclear fuel cycle. In particular it covered issues bearing on the formation of public policy in relation to the use of uranium as an energy source: economic risk, industrial risks, health effects, site selection, environmental issues, and public acceptance

The significance of zircon characteristic and its uranium concentration in evaluation of uranium metallogenetic prospect

International Nuclear Information System (INIS)

Li Yaosong; Zhu Jiechen; Xia Yuliang

1992-02-01

Zircon characteristic and its relation to uranium metallogenetic process have been studied on the basis of physics properties and chemical compositions. It is indicated that the colour of zircon crystal is related to uranium concentration; on the basis of method of zircon population type of Pupin J.P., the sectional plan of zircon population type has been designed, from which result that zircon population type of uranium-producing rock body is distributed mainly in second section, secondly in fourth section; U in zircon presents synchronous increase trend with Th, Hf and Ta; the uranium concentration in zircon from uranium-producing geologic body increases obviously and its rate of increase is more than that of the uranium concentration in rock; the period, in which uranium concentration in zircon is increased, is often related to better uranium-producing condition in that period of this area. 1785 data of the average uranium concentration in zircon have been counted and clear regularity has been obtained, namely the average uranium concentrations in zircon in rich uranium-producing area, rock, geologic body and metallogenetic zone are all higher than that in poor or no uranium-producing area, rock, geologic body and metallogenetic zone. This shows that the average uranium concentration in zircon within the region in fact reflects the primary uranium-bearing background in region and restricts directly follow-up possibility of uranium mineralization. On the basis of this, the uranium source conditions of known uranium metallogenetic zones and prospective provinces have been discussed, and the average uranium concentrations in zircon from magmatic rocks for 81 districts have been contrasted and graded, and some districts in which exploration will be worth doing further are put forward

Site-wide remedial alternative development in Bear Creek Valley, Oak Ridge Reservation

International Nuclear Information System (INIS)

Anderson, M.

1995-07-01

This paper presents a case study of an environmental restoration project at a major mixed waste site that poses unique challenges to remediation efforts. Bear Creek Valley is located immediately west of the Y-12 Plant on the Oak Ridge Reservation (ORR) in Oak Ridge, Tennessee. The Y-12 Plant was built in 1943 as part of the Manhattan Project, with its original mission being electromagnetic separation of uranium. Since being completed, the Y-12 Plant has also been used for chemical processing of uranium and lithium compounds as well as precision fabrication of components containing these and other materials. Wastes containing radionuclides, metals, chlorinated solvents, oils, coolants, polychlorinated biphenyis (PCBs), and others were disposed of in large quantities at Bear Creek Valley as a result of manufacturing operations at the Y-12 Plant. The Bear Creek Valley feasibility study is using innovative strategies to efficiently and thoroughly consider the information available regarding Bear Creek Valley and process options that could be combined into its remedial alternatives

Potential synergy between two renal toxicants: DTPA and uranium

International Nuclear Information System (INIS)

Muller, D.; Houpert, P.; Henge Napoli, M.H.; Paquet, F.; Muller, D.; Henge Napoli, M.H.; Metivier, H.

2006-01-01

At present, the most appropriate therapeutic approach to treat an accidental contamination with plutonium and uranium oxide mixture (MOX) is administration of diethylene-triamine-penta-acetate acid (DTPA) in order to accelerate plutonium excretion. As uranium and DTPA are both nephro-toxic compounds, the administration of DTPA after a contamination containing uranium could enhance the nephro-toxic effects of uranium. The aim of the present work was to study in vitro on a kidney proximal tubule cell line (LLC-PK 1 ) the cytotoxicity induced by increasing concentrations of uranium in presence of 3 different chemical forms of DTPA. The results showed that the DTPA used alone induced no cytotoxicity at the concentration used here (420 μM). However, this concentration of DTPA increased the cytotoxicity induced by uranium. This increase was maximal for uranium concentrations close to the lethal concentration for 50% of the cells and reached 37, 31 and 28% for anhydrous DTPA, Na 3 CaDTPA and Na 3 ZnDTPA, respectively. These results suggest that administration of DTPA could enhance the nephrotoxicity induced by uranium. (authors)

300 Area Uranium Stabilization Through Polyphosphate Injection: Final Report

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-30

The objective of the treatability test was to evaluate the efficacy of using polyphosphate injections to treat uranium-contaminated groundwater in situ. A test site consisting of an injection well and 15 monitoring wells was installed in the 300 Area near the process trenches that had previously received uranium-bearing effluents. This report summarizes the work on the polyphosphate injection project, including bench-scale laboratory studies, a field injection test, and the subsequent analysis and interpretation of the results. Previous laboratory tests have demonstrated that when a soluble form of polyphosphate is injected into uranium-bearing saturated porous media, immobilization of uranium occurs due to formation of an insoluble uranyl phosphate, autunite [Ca(UO2)2(PO4)2•nH2O]. These tests were conducted at conditions expected for the aquifer and used Hanford soils and groundwater containing very low concentrations of uranium (10-6 M). Because autunite sequesters uranium in the oxidized form U(VI) rather than forcing reduction to U(IV), the possibility of re-oxidation and subsequent re-mobilization is negated. Extensive testing demonstrated the very low solubility and slow dissolution kinetics of autunite. In addition to autunite, excess phosphorous may result in apatite mineral formation, which provides a long-term source of treatment capacity. Phosphate arrival response data indicate that, under site conditions, the polyphosphate amendment could be effectively distributed over a relatively large lateral extent, with wells located at a radial distance of 23 m (75 ft) reaching from between 40% and 60% of the injection concentration. Given these phosphate transport characteristics, direct treatment of uranium through the formation of uranyl-phosphate mineral phases (i.e., autunite) could likely be effectively implemented at full field scale. However, formation of calcium-phosphate mineral phases using the selected three-phase approach was problematic. Although

Application potential of sequence stratigraphy to prospecting for sandstone-type uranium deposit in continental depositional basins

International Nuclear Information System (INIS)

Li Shengxiang; Chen Zhaobo; Chen Zuyi; Xiang Weidong; Cai Yuqi

2001-01-01

Sequence stratigraphy has been widely used in hydrocarbon exploration and development, and great achievements have been achieved. However, its application to the prospecting for sandstone-type uranium deposits is just beginning. The metallogenic characteristics of sandstone-type uranium deposits and those of oil and gas are compared, and the relationship between sandstone-type uranium metallogenesis and the system tracts of sequence stratigraphy is studied. The authors propose that highest and system tracts are the main targets for prospecting interlayer oxidation zone type sandstone uranium deposits, and the incised valleys of low stand system tracts are favourable places for phreatic oxidation zone type sandstone uranium deposits, and transgressive system tracts are generally unfavorable to the formation of in-situ leachable sandstone-type uranium deposits. Finally, the authors look ahead the application potential of sequence stratigraphy to the prospecting for sandstone-type uranium deposits in continental depositional basins

Brazil's uranium/thorium deposits: geology, reserves, potential

International Nuclear Information System (INIS)

McNeil, M.

1979-01-01

With its area of 8.5 million square kilometers (3.3 million square miles) Brazil is the world's fifth largest nation, occupying almost one half of the continent of South America. Its vastness and its wide variety of geological terrain suggest that parts of Brazil may be favorable for many kinds of uranium deposits. The nation's favorability for uranium is indicated by the high correspondence between discoveries and the amount of exploration done to date. For the first time, the uranium and thorium resources of Brazil and their geologic setting are described here in a single volume. 270 refs

Removing uranium from drinking water by metal hydroxides and anion-exchange resin

International Nuclear Information System (INIS)

Lee, S.Y.; Bondietti, E.A.

1983-01-01

Results of bench-scale testing on uranium removal from a natural water that was chosen as a good representative of uranium-bearing waters indicated that conventional coagulant and lime softening treatment removes more than 85 percent of dissolved uranium (83 μg U/L) when an optimum pH and dosage were provided. A strong base anion-exchange column is a recommended option for the treatment of private well waters containing uranium at higher than desirable levels

Mechanism of near-fault ore deposition in stratal infiltration uranium deposits

International Nuclear Information System (INIS)

Belova, L.L.; Krichevets, G.N.; Shmariovich, E.M.; Salmin, Yu.P.; Tatarkin, M.A.

1986-01-01

The authors have examined the conditions for the formation of uranium ores associated with faults, which constitute a distinct type at various deposits associated with stratal zones of limonitization. Mathematical and experimental models were devised in which uranium-bearing oxidizing fluids and H 2 S-bearing reducing fluids interact in porous media. The algorithm used incorporated the hydrodynamics, the dispersal, and as far as possible also the thermodynamics and kinetics. This combined approach enabled them to examine not only the final result but also the intermediate stages, which are time- and space-dependent. The authors have found that the models reproduce zoning pattern found in natural uranium deposits. The paper describes the algorithm, discusses the results of mathematical modeling, and compares the results of mathematical and physical modeling. 16 references, 3 figures

Method of recovering uranium from aqueous solution

International Nuclear Information System (INIS)

Albright, R.L.

1980-01-01

Anion exchange resin derived from insoluble crosslinked polymers of vinyl benzyl chloride which are prepared by polymerizing vinyl benzyl chloride and a crosslinking monomer are particularly suitable in the treatment of uranium bearing leach liquors

Performance evaluation of indigenous controlled potential coulometer for the determination of uranium and plutonium

International Nuclear Information System (INIS)

Sharma, H.S.; Jisha, V.; Noronha, D.M.; Sharma, M.K.; Aggarwal, S.K.

2007-09-01

We have carried out performance evaluation of indigenously manufactured controlled potential coulometer for the determination of uranium and plutonium respectively in Rb 2 U(SO 4 ) 3 and K 4 Pu(SO 4 ) 4 chemical assay standards. The coulometric results obtained on uranium determination showed an insignificant difference as compared with the biamperometric results at 95% and 99.9% confidence levels while for plutonium determination showed a difference of -0.4% at 95% with respect to expected value. The results obtained show that indigenous coulometer is suitable for uranium and plutonium determination in chemical assay standards. (author)

Enriched uranium recovery at Los Alamos

International Nuclear Information System (INIS)

Herrick, C.C.

1984-01-01

Graphite casting scrap, fuel elements and nongraphite combustibles are calcined to impure oxides. These materials along with zircaloy fuel elements and refractory solids are leach-dissolved separately in HF-HNO 3 acid to solubilize the contained enriched uranium. The resulting slurry is filtered and the clear filtrate (to which mineral acid solutions bearing enriched uranium may be added) are passed through solvent extraction. The solvent extraction product is filtered, precipitated with H 2 O 2 and the precipitate calcined to U 3 O 8 . Metal is made from U 3 O 8 by conversion to UO 2 , hydrofluorination and reduction to metal. Throughput is 150 to 900 kg uranium per year depending on the type of scrap

Geochemical and sedimentologic problems of uranium deposits of Texas Gulf Coastal Plain

International Nuclear Information System (INIS)

Huang, W.H.

1978-01-01

Exploration targets for sedimentary uranium ore bodies in the Texas Gulf Coastal Plain include: (1) favorable source rocks for uranium, (2) favorable conditions for uranium leached and transported out of the source rocks, and (3) favorable geologic characteristics of the host rocks for the accumulation of uranium of economic importance. However, data available from known deposits point out more questions of research than answers. Mobility and accumulation of uranium of economic importance in host rocks are controlled by at least three factors - physical, chemical-mineralogic, and hydrologic - that interact dynamically. Physical factors include the nature (viscosity) of the transporting fluid, the permeability of host rock with respect to transporting solution in terms of medium rate, potential differentials, and temperature of the uranium-bearing solution in the macroenvironment. Chemical-mineralogic factors include the ionic strength of solution, chemical activities of species in the solution, chemical activities of pore water in host rocks, surface activity and surface energy of mineral constituents in host rocks, solubilities of ore and gangue minerals, pH, and Eh in the microenvironment. Hydrologic factors include fluctuation of the depth of the oxidation-reduction interfaces in the paleoaquifer host rocks, and their subsequent modification by present hydrologic factors. Geochemical mechanisms that are likely to have been in operation for uranium accumulation are precipitation, adsorption, and/or complexing. 4 figures

Solubility of airborne uranium compounds at the Fernald Environmental Management Project

International Nuclear Information System (INIS)

Heffernan, T.E.; Lodwick, J.C.; Spitz, H.; Neton, J.; Soldano, M.

2000-01-01

The in vitro volubility of airborne uranium dusts collected at a former uranium processing facility now undergoing safe shutdown, decontamination and dismantling was evaluated by immersing air filters from high volume samplers in simulated lung fluid and measuring the 238 U in sequential dissolution fractions using specific radiochemical analysis for uranium. X rays and photons from the decay of uranium and thorium remaining on the filter after each dissolution period were also directly measured using a planar germanium detector as a means for rapidly evaluating the volubility of the uranium bearing dusts. Results of these analyses demonstrate that two -distinct types of uranium bearing dusts were collected on the filters depending upon the location of the air samplers. The first material exhibited a dissolution half-time much less than one day and was most likely UO 3 . The dissolution rate of the second material, which was most likely U 3 O 8 , exhibited two components. Approximately one-third of this material dissolved with a halftime much less than one day. The remaining two-thirds of the material dissolved with half times between 230 ± 16 d and 1350 ± 202 d. The dissolution rates for uranium determined by radiochemical analysis and by gamma spectrometry were similar. However, gamma spectrometry analysis suggested a difference between the half times of 238 U and its daughter 234 Th which may have important implications for in vivo monitoring of uranium

Uranium decontamination of common metals by smelting, a review (handbook)

International Nuclear Information System (INIS)

Mautz, E.W.; Briggs, G.G.; Shaw, W.E.; Cavendish, J.H.

1975-01-01

The published and unpublished literature relating to the smelting of common metals scrap contaminated with uranium-bearing compounds has been searched and reviewed. In general, standard smelting practice produces ingots having a low uranium content, particularly for ferrous, nickel, and copper metals or alloys. Aluminum recovered from uranium contaminated scrap shows some decontamination by smelting but the uranium content is not as low as for other metals. Due to the heterogeneous nature and origin of scrap metals contaminated with uranium, information is frequently missing as to the extent of the initial contamination and the degree of decontamination obtained. The uranium content of the final cast ingots is generally all that is available. Results are summarized below by the primary composition of the uranium contaminated scrap metal. (U.S.)

National Uranium Resource Evaluation: Lewistown Quadrangle, Montana

International Nuclear Information System (INIS)

Culver, J.C.

1982-09-01

Uranium resources in the Lewistown Quadrangle, Montana, were evaluated to a depth of 1500 m (5000 ft). All existing geologic data were considered, including geologic surveys, literature, theses, radiometric surveys, oil- and water-well logs. Additional data were generated during the course of two field seasons, including the collection of more than 350 water, rock, crude oil and panned concentrate samples for analyses, sedimentary facies maps, structural geology and isopach maps, and field examination of reported areas of anomalous radioactivity. Three environments with potential for the occurrence of a minimum of 100 t of 0.01% U 3 O 8 were delineated. The most favorable environment is located in the southeastern portion of the quadrangle; here, Tertiary felsic dikes intrude four potential sandstone host rocks in the Kootenai Formation and the Colorado Shale. Structural-chemical traps for allogenic uranium are provided by the juxtaposition of oil-bearing domes. A second potential environment is located in the Eagle Sandstone in the northwestern and western portions of the quadrangle; here, anomalous water samples were obtained downtip from oxidized outcrops that are structurally related to Tertiary intrusive rocks of the Bearpaw and Highwood Mountains. Lignitic lenses and carbonaceous sandstones deposited in a near-shore lagoonal and deltaic environment provide potential reductants for hexavalent uranium in this environment. A third environment, in the Judith River Formation, was selected as favorable on the basis of water-well and gamma-ray log anomalies and their structural relationship with the Bearpaw Mountains. Organic materials are present in the Judith River Formation as potential reductants. They were deposited in a near-shore fluvial and lagoonal system similar to the depositional environment of the Jackson Group of the Texas Gulf Coast

Uranium favorability of tertiary rocks in the Badger Flats, Elkhorn Thrust Area, Park and Teller Counties, Colorado

International Nuclear Information System (INIS)

Young, P.; Mickle, D.G.

1976-10-01

Uranium potential of Tertiary rocks in the Badger Flats--Elkhorn Thrust area of central Colorado is closely related to a widespread late Eocene erosion surface. Most uranium deposits in the area are in the Eocene Echo Park Alluvium and Oligocene Tallahassee Creek Conglomerate, which were deposited in paleodrainage channels on or above this surface. Arkosic detritus within the channels and overlying tuffaceous sedimentary rocks of the Antero and Florissant Formations of Oligocene age and silicic tuffs within the volcanic units provide abundant sources of uranium that could be concentrated in the channels where carbonaceous debris facilitates a reducing environment. Anomalous soil, water, and stream-sediment samples near the Elkhorn Thrust and in Antero basin overlie buried channels or are offset from them along structural trends; therefore, uranium-bearing ground water may have moved upward from buried uranium deposits along faults. The area covered by rocks younger than the late Eocene erosion surface, specifically the trends of mapped or inferred paleochannels filled with Echo Park Alluvium and Tallahassee Creek Conglomerate, and the Antero Formation are favorable for the occurrence of uranium deposits

Review of international classification systems for uranium resources

International Nuclear Information System (INIS)

Wang Wenyou

2007-01-01

The two primary classification systems for uranium resources in common use in the whole world are described. These uranium resource classification systems were developed under two distinct philosophies, it implies two very different processes, criteria, terms and definitions from which the systems evolved and were implemented. However, the two primary systems are all based on two considerations: the degree of geological confidence and the degree of economic attractiveness based on cost of producing the resource. The uranium resource classification methods currently used in most major uranium producing countries have all a bearing on the two aforesaid classification systems. The disparity exists only in the way or practice of classifying and estimating the uranium resources for reasons of different political and economical systems in various countries. The harmonization of these resource classification systems for uranium can be realized with the economic integration on a global scale. (authors)

Geology and structure of major uranium-bearing zones in India and their exploration

International Nuclear Information System (INIS)

Nagabhushana, J.C.; Vasudeva Rao, M.; Sahasrabudhe, G.H.; Krishnamoorthy, B.; Suryanarayana Rao, C.; Rama Rao, Y.N.

1976-01-01

Radiogeologic, lithostratigraphic, tectonic, and crustal evolutionary considerations have enabled the recognition of three major uranium provinces in India: the Singhbhum Province in the north-east; the Rajasthan Province in the north-west; and the Madhya Pradesh Province in central India. The paper describes the salient features of the three uranium provinces, with particular emphasis on their structural set-up, magmatectonics, and the controls of uranium mineralization, and presents a few recent case histories of individual deposits (Bagjata and Turamdih in Singhbhum, and Dhabi-Dumhat in Madhya Pradesh) discovered by integrated exploration techniques. The three uranium provinces are related to major deep-seated faults: the Singhbhum Province lies at the arcuate north-east end of the deep fault of the Eastern Ghats; the Rajasthan Province parallels the great boundary fault; and the Madhya Pradesh Province aligns with the Mahanadi-Son rift system. Some of the plausible explanations for these remarkable features are: localization of uranium ore during episodes of crustal fracturing in Precambrian times; reactivation and rejuvenation of favourable basement structures; and the role of local 'hot spots' (aided by compressional and vertical tectonics) in crustal zones anomalously enriched in the heat-producing elements. Uranium exploration strategy in India during the last three decades reveals two significant trends - the application of conventional radiometric techniques during the period 1950-65; and introduction of sophisticated methodology comprising non-radiometric geophysical techniques, emanometry, aerial and car-borne gamma-ray spectrometry, geochemical surveys, and photogeological techniques as supplements to conventional radiometry, during the period 1965-75. It is concluded that extension of such integrated exploration techniques to favourable virgin terrains in India would lead to newer and richer uranium ore discoveries. (author)

Investigation of Alaska's uranium potential. Part 1. Reconnaissance program, West-Central Alaska and Copper River basin. Part 2. Uranium and thorium in granitic and alkaline rocks in Western Alaska

International Nuclear Information System (INIS)

Eakins, G.R.; Jones, B.K.; Forbes, R.B.

1977-02-01

A 6-week reconnaissance program was conducted in west-central Alaska and in the Copper River basin--Chitina River valley area to aid in determining the uranium potential of the state. Division personnel also submitted samples from the Healy, Eagle, and Charley River quadrangles. Collected were 916 stream-sediment samples and 427 bedrock samples for uranium, thorium, and potassium oxide determinations, and 565 water samples for uranium analyses. A statistical analysis of the determinations was made using a computer at the University of Alaska. Thresholds, anomalies, and U:Th ratios were calculated for eight separate regions. Anomalous values of the U, Th, and K 2 O, and radiometric measurements are discussed. A combination of all uranium exploration techniques is needed to locate potential uranium deposits in Alaska. Correlations between aerial and ground radiometric surveys and geochemical surveys were often lacking, indicating that each method may or may not be effective, depending on local conditions. One hundred and eight rock samples were selected from traverses across five plutons in western Alaska and analyzed for uranium, thorium, and potassium. The highest uranium concentrations detected were 86 and 92 ppM from a mineralized dike intrusion zone in the Selawik Lake Complex. Analysis of individual plutons yields strong correlations between mineralogy and radioactivity. The mineralogical variable that correlates with uranium or thorium varies from one pluton to the next. Based on these correlations, mineralogical guidelines are offered for the selection of uranium enriched variants in four of the five plutons

Uranium isotopic disequilibrium in ground water as an indicator of anomalies

International Nuclear Information System (INIS)

Osmond, J.K.; Cowart, J.B.; Ivanovich, M.

1983-01-01

Because of the unique elemental and isotopic properties of uranium, ground water surveys are a most appropriate approach to prospecting for surficial and secondary uranium deposits. Uranium4+ is generally immobile, but in oxidising and carbonate bearing waters U 6 + is mobile and conservative. Uranium 234 is the radiogenic daughter of 238 U. The intervening α-decay event causes recoil displacements and radioactive disequilibrium between the two isotopes in open systems such as surficial aquifers. Extreme variations in dissolved uranium composition of ground waters combined with significant variations in the ratio 234 U/ 238 U are indicative of the proximity and stage of evolution of secondary deposits. (author)

Uranium-bearing zeolite-analcime concretions with authi genous loellingite

International Nuclear Information System (INIS)

Kudryavtsev, V.E.; Kashenova, A.G.; Gundrenko, E.I.

1978-01-01

Zeolite-analcime concrections, mounted in green-coloured molasses of middle Palaeozoic, were studied by X-ray radiometric method. It is established that concrection formator is heliogenious carbonated pellitemorphic material arisen at the cost of aluminium-silicon gels in the process of their dehydration into the sediment diagenesis stage. Uranium, molybdenum, arsenic, zirconium and other metals are scattered in a dispersed way in the pellitemorphic material. They are present in the aqueous solution of liquid inclusions. They can also form smallest extractions of nasturane, uranium black (coffinite), loellingites, pyrite, chalcopyrite, arseno-pyrite, molybdenite and others in the substrate. Loellingite forms tetra and hexabeam triplets. There are xenomorphic extractions and seldom crystals with extended rectangular or hexagonal cross sections in big grains. Its main constituents are arsenic and ferrum. The loellingite presence in the concrections studied testifies to the possibility of its formation not only under the conditions of hydrothermal and metasomatic deposits, but in a wider range of thermodynamic conditions

Formation mechanism of self-potential at ISL-amenable interlayer oxidation zone sandstone-type uranium deposit and the simulation and application of self-potential anomalies

International Nuclear Information System (INIS)

Tang Hongzhi; Liu Qingcheng; Su Zhaofeng; Gong Yuling

2006-01-01

Based on the analysis of geochemical characteristics and metallogenic physico-chemical conditions of ISL-amenable sandstone-type uranium deposits, the formation mechanism of self-potential field is discussed, a mathematic calculation model has been set up, and the simulation calculation has been performed for self-potential anomalies above uranium ore bodies of ordinary form, features of survey curve are analysed and methods for correcting topography at self-potential anomalies are discussed, and a simulation curve of self-potential in the area of slope topography has been presented. Finally, the availability of the method is demonstrated by an example. (authors)

Effects of uranium concentration on microbial community structure and functional potential.

Science.gov (United States)

Sutcliffe, Brodie; Chariton, Anthony A; Harford, Andrew J; Hose, Grant C; Greenfield, Paul; Elbourne, Liam D H; Oytam, Yalchin; Stephenson, Sarah; Midgley, David J; Paulsen, Ian T

2017-08-01

Located in the Northern Territory of Australia, Ranger uranium mine is directly adjacent to the UNESCO World Heritage listed Kakadu National Park, with rehabilitation targets needed to ensure the site can be incorporated into the park following the mine's closure in 2026. This study aimed to understand the impact of uranium concentration on microbial communities, in order to identify and describe potential breakpoints in microbial ecosystem services. This is the first study to report in situ deployment of uranium-spiked sediments along a concentration gradient (0-4000 mg U kg -1 ), with the study design maximising the advantages of both field surveys and laboratory manipulative studies. Changes to microbial communities were characterised through the use of amplicon and shotgun metagenomic next-generation sequencing. Significant changes to taxonomic and functional community assembly occurred at a concentration of 1500 mg U kg -1 sediment and above. At uranium concentrations of ≥ 1500 mg U kg -1 , genes associated with methanogenic consortia and processes increased in relative abundance, while numerous significant changes were also seen in the relative abundances of genes involved in nitrogen cycling. Such alterations in carbon and nitrogen cycling pathways suggest that taxonomic and functional changes to microbial communities may result in changes in ecosystem processes and resilience. © 2017 Society for Applied Microbiology and John Wiley & Sons Ltd.

Uranium prospecting through radon detection; La prospection de l'uranium par le radon

Energy Technology Data Exchange (ETDEWEB)

Pradel, J [Commissariat a l' Energie Atomique, Saclay (France). Centre d' Etudes Nucleaires

1956-07-01

Prospecting rests on the determination of the concentration of ground air in radon. Radon diffusing from deep uranium bearing layers is detected in upper ground layers. (author) [French] La prospection est basee sur l'etude de la concentration en radon dans l'air du sol. Dans les terrains superficiels, on decele le radon qui diffuse a partir des couches profondes uraniferes. (auteur)

Research within the coordinated progamme on bacterial leaching of uranium ores

International Nuclear Information System (INIS)

Marjanovic, D.

1978-01-01

Effect of magnetic field on the growth rate of Thiobacillus ferrooxidans bacteria was studied at intensities of 30, 100, 2400, and 4000 Oe. Low intensity magnetic field was found to stimulate the bacteria growth rate and the rate of ferrosulphate oxidation with optimum values at 30 to 300 Oe (maximum at 300 Oe). Magnetic field of high intensity (2400, 3200, 4000 Oe) inhibits the growth of bacteria and processes of bacterial oxidation. The possibility was also studied of using biocides for inhibiting bacterial processes in uranium-bearing waste dumps. The use of biocides resulted in a decrease of uranium-bearing waste dump autochthonous microflora density

Mine design for producing 100,000 tons per day of uranium-bearing Chattanooga Shale

International Nuclear Information System (INIS)

Hoe, H.L.

1979-01-01

Chattanooga Shale, underlying some 40,000 square miles in the southeastern United States, is considered to be a potentially large, low-grade source of uranium. The area in and near Dekalb County, Tennessee, appears to be the most likely site for commercial development. This paper deals with the mine design, mining procedures, equipment requirements, and operating maintenance costs for an underground mining complex capable of producing 100,000 tons of Chattanooga Shale per day for delivery to a beneficiation process

Discussion on the application potential of thermal infrared remote sensing technology in uranium deposits exploration

International Nuclear Information System (INIS)

Wang Junhu; Zhang Jielin; Liu Dechang

2011-01-01

With the continual development of new thermal infrared sensors and thermal radiation theory, the technology of thermal infrared remote sensing has shown great potential for applications in resources exploration, especially in the field of uranium exploration. The paper makes a systemic summary of the theoretical basis and research status of the thermal infrared remote sensing applications in resources exploration from the surface temperature, thermal inertia and thermal infrared spectrum. What's more, the research objective and the research content of thermal infrared remote sensing in the uranium deposits exploration applications are discussed in detail. Besides, based on the thermal infrared ASTER data, the paper applies this technology to the granite-type uranium deposits in South China and achieves good result. Above all, the practice proves that the thermal infrared remote sensing technology has a good application prospects and particular value in the field of uranium prospecting and will play an important role in the prospecting target of the uranium deposits. (authors)

PROCESS FOR THE RECOVERY AND PURIFICATION OF URANIUM DEPOSITS

Science.gov (United States)

Carter, J.M.; Kamen, M.D.

1958-10-14

A process is presented for recovering uranium values from UCl/sub 4/ deposits formed on calutrons. Such deposits are removed from the calutron parts by an aqueous wash solution which then contains the uranium values in addition to the following impurities: Ni, Cu, Fe, and Cr. This impurity bearing wash solution is treated with an oxidizing agent, and the oxidized solution is then treated with ammonia in order to precipitate the uranium as ammonium diuranate. The metal impurities of iron and chromium, which form insoluble hydroxides, are precipitated along with the uranium values. The precipitate is separated from the solution, dissolved in acid, and the solution again treated with ammonia and ammonium carbonate, which results in the precipitation of the metal impurities as hydroxides while the uranium values remain in solution.

Uranium dioxide sintering Kinetics and mechanisms under controlled oxygen potentials

International Nuclear Information System (INIS)

Freitas, C.T. de.

1980-06-01

The initial, intermediate, and final sintering stages of uranium dioxide were investigated as a function of stoichiometry and temperature by following the kinetics of the sintering reaction. Stoichiometry was controlled by means of the oxygen potential of the sintering atmosphere, which was measured continuously by solid-state oxygen sensors. Included in the kinetic study were microspheres originated from UO 2 gels and UO 2 pellets produced by isostatic pressing ceramic grade powders. The microspheres sintering behavior was examined using hot-stage microscopy and a specially designed high-temperature, controlled atmosphere furnace. This same furnace was employed as part of an optical dilatometer, which was utilized in the UO 2 pellet sintering investigations. For controlling the deviations from stoichiometry during heat treatment, the oxygen partial pressure in the sintering atmosphere was varied by passing the gas through a Cu-Ti-Cu oxygen trap. The trap temperature determined the oxygen partial pressure of the outflowing mixture. Dry hydrogen was also used in some of the UO sub(2+x) sintering experiments. The determination of diametrial shrinkages and sintering indices was made utilizing high-speed microcinematography and ultra-microbalance techniques. It was observed that the oxygen potential has a substantial influence on the kinetics of the three sintering stages. The control of the sintering atmosphere oxygen partial pressure led to very fast densification of UO sub(2+x). Values in the interval 95.0 to 99.5% of theoretical density were reached in less than one minute. Uranium volume diffusion is the dominant mechanism in the initial and intermediate sintering stages. For the final stage, uranium grain boundary diffusion was found to be the main sintering mechanism. (Author) [pt

Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps and human health hazards associated with uranium exploration and mining, Red, White, and Fry Canyons, southeastern Utah, 2007

Science.gov (United States)

Beisner, Kimberly R.; Marston, Thomas M.; Naftz, David L.; Snyder, Terry; Freeman, Michael L.

2010-01-01

During May, June, and July 2007, 58 solid-phase samples were collected from abandoned uranium mine waste dumps, background sites, and adjacent streambeds in Red, White, and Fry Canyons in southeastern Utah. The objectives of this sampling program were to (1) assess the nonpoint-source chemical loading potential to ephemeral and perennial drainage basins from uranium waste dumps and (2) assess potential effects on human health due to recreational activities on and around uranium waste dumps on Bureau of Land Management property. Uranium waste-dump samples were collected using solid-phase sampling protocols. After collection, solid-phase samples were homogenized and extracted in the laboratory using a leaching procedure. Filtered (0.45 micron) water samples were obtained from the field leaching procedure and were analyzed for major and trace elements at the Inductively Coupled Plasma-Mass Spectrometry Metals Analysis Laboratory at the University of Utah. A subset of the solid-phase samples also were digested with strong acids and analyzed for major ions and trace elements at the U.S. Geological Survey Geologic Division Laboratory in Denver, Colorado. For the initial ranking of chemical loading potential for uranium waste dumps, results of leachate analyses were compared with existing aquatic-life and drinking-water-quality standards. To assess potential effects on human health, solid-phase digestion values for uranium were compared to soil screening levels (SSL) computed using the computer model RESRAD 6.5 for a probable concentration of radium. One or more chemical constituents exceeded aquatic life and drinking-water-quality standards in approximately 64 percent (29/45) of the leachate samples extracted from uranium waste dumps. Most of the uranium waste dump sites with elevated trace-element concentrations in leachates were located in Red Canyon. Approximately 69 percent (31/45) of the strong acid digestible soil concentration values were greater than a calculated

Status Report from Czechoslovakia [Processing of Low-Grade Uranium Ores

Energy Technology Data Exchange (ETDEWEB)

Civin, V; Belsky, M [Research and Development Laboratory No.3 of the Uranium Industry, Prague, Czechoslovakia (Czech Republic)

1967-06-15

The present paper deals with the fundamental problems and the main routes followed in processing low-grade uranium ores in CSSR. In this connection it may be useful to discuss the definition of low-grade ore. In our country this term is applied to uraniferous material with a very low content of uranium (of the order of 0.01%) whose treatment causes no particular difficulty. However, the same term is also used to designate those materials whose processibility lies on the verge of economic profitability. In our view, this classification, of an ore using two independent criteria (i.e. uranium content and processing economy) is useful from the standpoint of technology. The treatment of both such ore types is as a rule carried out by specific technological processes. Consequently, low-grade uranium ores can be divided into two groups: (1) Ores with a low uranium content. To this category belong in our country uraniferous materials which originate as a by-product of technological processes used in processing other materials. This is primarily gangue and tailings of various physical or physico-chemical pretreatment operations to which the ore is subjected at the mining site. Mention should be made in this connection of mine waters, which represent a useful complementary source of uranium despite their low uranium content (of the order of milligrams per litre). (2) Ores whose economical treatment is problematic. To this category belong deposits of conventional ore types with a uranium content on the limit of profitable treatment. Also, those deposits containing atypical materials possessing such properties which impair the economy of their treatment. This includes ores with a considerable amount of components which are difficult to separate and which at the same time consume the leaching agents. Finally, it covers uranium-bearing materials in refractory forms which are difficult to dissolve and also some special materials, such as lignites, uranium-bearing shales, loams

Potentiality of uranium biosorption from nitric acid solutions using shrimp shells.

Science.gov (United States)

Ahmed, S H; El Sheikh, E M; Morsy, A M A

2014-08-01

Biosorption has gained important credibility during recent years because of its good performance and low cost. This work is concerned with studying the potentiality of the chitin component of the shrimp shells for uranium biosorption from nitric acid liquid solutions. The structural characteristics of the working chitin have been determined via Fourier Transform Infrared Spectroscopy (FTIR). The surface morphology was examined using Scanning Electron Microscopy (SEM). The adsorption capacity of biomass was investigated experimentally. The influence of contact time, pH, metal ion concentration, solution volume to mass ratio and temperature were evaluated and the results were fitted using adsorption isotherm models. The kinetic of uranium biosorption was also investigated as well as biosorption thermodynamic. Copyright © 2014 Elsevier Ltd. All rights reserved.

International Uranium Resources Evaluation Project (IUREP) national favourability studies: Burma

International Nuclear Information System (INIS)

1977-10-01

There is no information on production of nuclear raw materials in Burma, although there are some uranium occurrences. Hunting Geophysics Ltd has done some aerial prospecting work in the area of Victoria Point in Southern Burma. All the data collected has been plotted on several maps and issued to various Burmese organizations, with a complete report. The follow-up ground exploration was done by a prospecting party headed by Dr Gjelsvik. The Hunting Geophysics' and Dr Gjelsvik reports are not available in the IAEA. The Raw Materials Division in the Union of Burma Atomic Energy Center commenced operations in 1955. The area of Mogok was selected by U Soo Win, the head of the Division, as most favourable for uranium exploration. The region is mountainous, with heavy forest cover. A ground gamma-ray survey was carried out in Mogok Mineral Belt by two geologists accompanied by two assistants, at a spacing of one km. This work showed monazite in all streams over an area of about 150 sq km and has given a detailed studies led to the discovery of some uraninite and pitchblende in the overburden of an old lode. Based, on these first discoveries the Government of Burma requested assistance from the IAEA and an expert was sent there for a period of one year. His field work was mainly limited in the Mogok Mineral Belt, however some reconnaissance field trips were made in other parts of the country. Dr D L Searle concluded that the Mogok area represents a zone of high temperature mineralization but a lower temperature form of uranium mineralization may have developed along the outer edges of the principal high grade zone. He recommended that the area between the Mogok scarp and the Shweli River be systematically traversed. Uranium bearing minerals in Burma are the following: monazite bearing beach sands near Amherst, Tenasserim; monazite placers from near Momeik, Northern Shan States; uraninte crystals from the gem-gravels around Mogok; a radioactive anomaly in syenite at

International Uranium Resources Evaluation Project (IUREP) national favourability studies: Burma

Energy Technology Data Exchange (ETDEWEB)

NONE

1977-10-15

There is no information on production of nuclear raw materials in Burma, although there are some uranium occurrences. Hunting Geophysics Ltd has done some aerial prospecting work in the area of Victoria Point in Southern Burma. All the data collected has been plotted on several maps and issued to various Burmese organizations, with a complete report. The follow-up ground exploration was done by a prospecting party headed by Dr Gjelsvik. The Hunting Geophysics' and Dr Gjelsvik reports are not available in the IAEA. The Raw Materials Division in the Union of Burma Atomic Energy Center commenced operations in 1955. The area of Mogok was selected by U Soo Win, the head of the Division, as most favourable for uranium exploration. The region is mountainous, with heavy forest cover. A ground gamma-ray survey was carried out in Mogok Mineral Belt by two geologists accompanied by two assistants, at a spacing of one km. This work showed monazite in all streams over an area of about 150 sq km and has given a detailed studies led to the discovery of some uraninite and pitchblende in the overburden of an old lode. Based, on these first discoveries the Government of Burma requested assistance from the IAEA and an expert was sent there for a period of one year. His field work was mainly limited in the Mogok Mineral Belt, however some reconnaissance field trips were made in other parts of the country. Dr D L Searle concluded that the Mogok area represents a zone of high temperature mineralization but a lower temperature form of uranium mineralization may have developed along the outer edges of the principal high grade zone. He recommended that the area between the Mogok scarp and the Shweli River be systematically traversed. Uranium bearing minerals in Burma are the following: monazite bearing beach sands near Amherst, Tenasserim; monazite placers from near Momeik, Northern Shan States; uraninte crystals from the gem-gravels around Mogok; a radioactive anomaly in syenite at

Molybdenum from uranium solutions

International Nuclear Information System (INIS)

Gardner, H.E.

1981-01-01

A method of removing molybdenum from a uranium bearing solution is claimed. It comprises adding sufficient reactive lead compound to supply at least 90 percent of the stoichiometric quantity of lead ion required to fully react with the molybdenum present to form insoluble lead molybdate and continuing the reaction with agitation until the desired percentage of the molybdenum present has reacted with the lead ion

Characterization of Uranium-Bearing Material by Passive Non-Destructive Gamma Spectrometry

International Nuclear Information System (INIS)

Lakosi, L.; Zsigrai, J.; Nguyen, C.T.

2009-01-01

Characterization of nuclear materials is equally important in nuclear safeguards (inventory verification) and in nuclear security (revealing illicit trafficking). Analysis of materials is a key issue in both fields. Natural (NU), depleted (DU), low-enriched (LEU), and high-enriched uranium (HEU) samples were analysed by high resolution gamma spectrometry (HRGS). Isotopic composition and total U-content of reactor fuel pellets and powder were determined. A unique HRGS method was developed for the first time for determining the production date of the material of unknown origin. Identifying reprocessed uranium proved to be possible by HRGS as well.

Heterogeneity of uranium host rocks in Zhiluo formation in Dongsheng area and its relation to uranium mineralization

International Nuclear Information System (INIS)

Yi Chao; Zheng Yunlong; Wang Mingtai

2013-01-01

Numbers of uranium deposits have be found in Dongsheng area. The major ore-bearing layer is the sub member of the lower member of the Zhiluo Formation, the heterogeneity of host rocks plays an important role during the process of uranium mineralization. This paper sorted and counted up the data of sand body and the impermeable bed in Dongsheng area to study the heterogeneity characteristic of host rock and its relationship to uranium mineralization in horizontal and vertical directions. The thickness of sand body in Dongsheng area decreases gradually from northwest to southeast. The uranium mineralization is mainly distributed in the place where the thickness of sand body changed from the thick to the thin. Statistics shows that the best uranium mineralization occurred in sand body thickness between 20 m to 40 m and the sand rate over 60% in the eastern part of Dongsheng area. And the best uranium mineralization in the western part occurred in area of sand body thickness between 60 m to 70 m and the sand rate over 70%. In vertical direction, the numbers and the thickness of the impermeable beds have negative relation to sand rate. Moreover, uranium deposits generally exist in the area of less number impermeable bed and small thickness. The uranium mineralization grade decreased with the increase of number and thickness of the impermeable beds. (authors)

Uranium mineralization in the Molteno and Elliot Formations

International Nuclear Information System (INIS)

Le Roux, J.P.

1990-01-01

To date very little has been published on the uranium deposits of the Molteno and Elliot Formations. Two selected deposits from these formations are described and compared to the uranium occurrences of the Beaufort Group. Whereas the latter are generally confined to channel zones due to the fine grain size and impermeable nature of the host sandstones, uranium in the Molteno and Elliot Formations seems to be concentrated in the less permeable 'island' areas. An apparent association with dolerite sills and dykes also suggests that the host sandstones were still sufficiently permeable after intrusion of the dolorite so that ground waters could remobilize the uranium. This agrees with recently published isotopic ages for the mineralization. There is a distinct possibility that roll-type uranium deposits may be present in the Molteno and Elliot Formations, and any future exploration should bear this in mind. 9 figs., 1 tab., 16 refs

An analysis of prominent prospect of in-situ sandstone type uranium deposits in Yanji basins group, Jilin province

International Nuclear Information System (INIS)

Peng Zhidong; Zhang Shuyi

2003-01-01

In Mesozoic-Cenozoic era, many medium-small-sized sedimentary basins had been formed in Yanbian draped-faulted region of Jilin Province. The basement of these basins is constituted of U-riched granite body produced during late Hercynian-early Yanshan period. Uranium-mineralization has been found in coal-bearing formation, oil-bearing formation and in tint layer of red formation. On the bases of analyzing of uranium source, geologic tectonic, paleoclimatology, paleogeography, hydrogeology and reconstruction, it is concluded that there is a prominent prospect to discover large in-situ sandstone-type uranium deposits in Yanji basins. (authors)

Uranium industry framework

International Nuclear Information System (INIS)

Riley, K.

2008-01-01

The global uranium market is undergoing a major expansion due to an increase in global demand for uranium, the highest uranium prices in the last 20 years and recognition of the potential greenhouse benefits of nuclear power. Australia holds approximately 27% of the world's uranium resources (recoverable at under US$80/kg U), so is well placed to benefit from the expansion in the global uranium market. Increasing exploration activity due to these factors is resulting in the discovery and delineation of further high grade uranium deposits and extending Australia's strategic position as a reliable and safe supplier of low cost uranium.

Low grade uranium ores as potential sources of raw material

International Nuclear Information System (INIS)

Venzlaff, H.

1976-01-01

Reports on the uranium requirement and the uranium reserves show that, even if the demand were to be stretched out slightly, the rate of new discoveries of uranium would have to be doubled or even tripled within a few years in order to ensure supply. Despite some spectacular discoveries of large scale deposits in Australia it must be said that only very few truly new uranium provinces have been discovered over the past twenty years. In this situation more attention is now being devoted to low grade uranium depositis, to findings whose concentration does not exceed 1,000 ppm. These deposits contain quantities of uranium many times larger than the deposits that can now be mined at prices up to 30/lb of U 3 O 8 . Even now low grade uranium ore is being mined as a byproduct, with the actual valuable mineral producing most of the income from mining activities. However, if one strikes a balance in this situation, one finds that only part of the requirement can be met in this way. Hence, all possibilities must be exhausted to mine uranium as a byproduct, new techniques of uranium production from low grade ores must be developed, and also conventional prospection must be intensified, if the continuity of supply of the nuclear power stations in the eighties and nineties is to be guaranteed. (orig.) [de

Felsic magmatism and uranium deposits

International Nuclear Information System (INIS)

Cuney, M.

2014-01-01

Uranium strongly incompatible behaviour in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behaviour, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth which crystallized uraninite appeared at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: peralkaline, high-K metaluminous calc-alkaline, L-type peraluminous ones and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass in their volcanic equivalents represent the best U source. Peralkaline granites or syenites represent the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction at the present economic conditions and make them unfavourable U sources for other deposit types. By contrast, felsic peralkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals [U-thorite, allanite, Nb oxides] become metamict. The volcanic rocks of the same geochemistry may be also a

Types of tectonic structures, sedimentary volcanogenetic formations of a mantle, favourable processes for exogenetic and polygenetic uranium deposits formation

International Nuclear Information System (INIS)

Danchev, V.I.; Komarnitskij, G.M.; Levin, V.N.; Shumlyanskij, V.A.

1985-01-01

Factors, affecting mineralization processes are considered. Characteristic features of uranium-bearing provinces are as follows: the presence of crust of continental type; deep-seated tectonic structures-rises and saggings, roofs, gneiss domes, rift zones and transform fractures; specialization for uranium of sedimentary and magmatic formations; the presence of manifestation regions of deep thermal and gaseous flow, etc. In uranium-bearing provinces territories favourable for the manifestation of different types of uranium mineralization: metamorphogenetic, polygenetic and exogenetic ones, are singled out. Different epochs of uranium ore formation are established. In sedimentary masses tectonic regime and climate are of special importance, and for epigenetic deposits, formed with an aid of underground waters-hydrogeological conditions. In the limits of the main structural elements of the Earth crust and geotectonic structures of higher orders the following types of sedimentary and volcanic formations can be singled out: 1-formations with exogenous uranium mineralization; 2-formations, accumulated in the epochs of epigenous ore formation; 3-formations fav ourable for epigenous uranium deposit formation; 4-formations unfavourable for the formation and localization of uranium mineralization

White sand potentially suppresses radon emission from uranium tailings

Science.gov (United States)

Abdel Ghany, H. A.; El Aassy, Ibrahim E.; Ibrahim, Eman M.; Gamil, S. H.

2018-03-01

Uranium tailings represent a huge radioactive waste contaminant, where radon emanation is considered a major health hazard. Many trials have been conducted to minimize radon exhalation rate by using different covering materials. In the present work, three covering materials, commonly available in the local environment, (kaolin, white sand and bentonite) have been used with different thickness 10, 15, and 20 mm). 238U, 232Th, 40K and the radon exhalation rate were measured by using gamma spectrometry with a Hyper Pure Germanium (HPGe) detector and solid state nuclear track detectors (CR-39). Radon exhalation rate, calculated before and after covering, ranged from 2.80 ± 0.14 to 4.20 ± 0.21 Bq m-2 h-1, and from 0.30 ± 0.01 to 4.00 ± 0.20 Bq m-2 h-1, respectively. Also, the attenuation coefficients of different covering materials and radon emanation were calculated. The obtained results demonstrate that covering of uranium tailings by kaolin, white sand and bentonite has potentially minimized both the radon exhalation rate and the corresponding internal doses.

Relation between uranium mineralization and structural features, Gebel Gattar, north eastern desert, Egypt

International Nuclear Information System (INIS)

Salman, A.B.; Shalaby, M.H.; Abuzaid, M.M.; Ragab, A.

1998-01-01

Gebel Gattar area is situated in the northern Eastern Desert of Egypt, SW Hurghada city and is considered as an area of high potentialities for uranium deposits. The area is covered by Hammamat sediments and Gattarian granites. The Hammamat sediments are dissected by different types of dykes, while Gebel Gattar granites are cut only by basic dykes. These granites are mentioned as the younger pink granites, perthitic leucogranites, calc-alkaline and within plate granites. The structural deformations of the study area are represented by primary structures and secondary ones. The most prevailing structures are folding, faulting and jointing. The faults, especially those trending in the NNE-SSW and N-S directions played as pass ways to the ascending uranium-bearing hydrothermal solutions carrying uranium mineralizations. Most of them are located within a large pull apart basin. It is found from the relation between structures and uranium mineralization within the highly pro missing shear zones that uranium mineralizations are located within a large pull-apart basin, having about 2 km length and 0.5 km width. This idea is based up on the distribution of uranium mineralized lenses as shown in a block diagram. This conclusion is based on the structural framework of the area, the shape of mineralization and its distribution and their mutual relationships of Gl, Gll and GVl shear zones

International Uranium Resources Evaluation Project (IUREP) national favourability studies: Sweden

International Nuclear Information System (INIS)

1977-11-01

Sweden, covers an area of approx. 450 000 square kilometers. It has a population of 8 millions. With few exceptions in the northern part the access can be regarded as good. A dense network of motorroads and railroad exists. The results obtained by the exploration works combined with other available geo-information permit a separation of two principal uranium provinces in Sweden. The first one is confined to sediments of Upper Cambrian and Lower Ordovician which appears in Southern Sweden and along the border of the Caledonian mountain range in Central Sweden. The uranium occurrence are stratiform, of blackshale type which occurs in the Peltura zone of Upper Cambrian or they are associated to a phosphatite-bearing unit of Lower Ordovician overlying the Cambrian shale formation. The distribution of uranium in Upper Cambrian rocks is in general dependant on their lithology which itself is related to the paleography. This conditions explain relatively higher uranium content of the shale from Billigen.The potential resources of the province are estimated at about 1 million tonnes uranium. The second uranium province, called Arjeplog-Arvidsjaur, situated immediately south of the Arctic circle, comprises one deposit - Pleutajokk - and a group of more than twenty occurrences of similar characteristics and age (1 700 - 1 800 my.). The results of the past exploration have shown that uranium is present in different types of rocks. Because of the presence of uranium in many of the pegmatites the possibility of the formation of large low grade deposits should be tested. Favourable areas are those regions where the geological conditions are similar to the geology of the Grenville province in Canada or the Damara belt of SW-Africa. Special studies are recommended on this subject

Microbial communities in low permeability, high pH uranium mine tailings: characterization and potential effects.

Science.gov (United States)

Bondici, V F; Lawrence, J R; Khan, N H; Hill, J E; Yergeau, E; Wolfaardt, G M; Warner, J; Korber, D R

2013-06-01

To describe the diversity and metabolic potential of microbial communities in uranium mine tailings characterized by high pH, high metal concentration and low permeability. To assess microbial diversity and their potential to influence the geochemistry of uranium mine tailings using aerobic and anaerobic culture-based methods, in conjunction with next generation sequencing and clone library sequencing targeting two universal bacterial markers (the 16S rRNA and cpn60 genes). Growth assays revealed that 69% of the 59 distinct culturable isolates evaluated were multiple-metal resistant, with 15% exhibiting dual-metal hypertolerance. There was a moderately positive correlation coefficient (R = 0·43, P tailings depth was shown to influence bacterial community composition, with the difference in the microbial diversity of the upper (0-20 m) and middle (20-40 m) tailings zones being highly significant (P tailings zone being significant (P tailings environment, along with their demonstrated capacity for transforming metal elements, suggests that these organisms have the potential to influence the long-term geochemistry of the tailings. This study is the first investigation of the diversity and functional potential of micro-organisms present in low permeability, high pH uranium mine tailings. © 2013 The Society for Applied Microbiology.

The relations between hydrodynamic characteristics and interbedding oxidation zone type uranium mineralization

International Nuclear Information System (INIS)

Bai Jingping

2001-01-01

Infiltrating type hydrodynamic way controls the formation of interbedding oxidation zone type uranium deposit. The author analyzes hydrodynamic condition of Songliao basin and concludes that during evolution and development of Songliao basin, Water-bearing petrofabric of Mingshui Formation and above inherit completely infiltrating hydrodynamic way as they were deposited and that Sifangtai Formation inherit the way to some extent, that below Sifangtai Formation water bearing petrofabric were completely reformed in northern part of Songliao watershed. The contact line between infiltrating and out filtrating type hydrodynamic way, e.g. underground water dividing lines formed in different geological period, restricts development of interbedding oxidation zone in this period and controls uranium mineralization

Amine synergism in uranium extraction

International Nuclear Information System (INIS)

Rinelli, G.; Abbruzzese, C.

1977-01-01

Commercial products based on C 8 to C 12 tertiary amine mixtures are now widely used in the solvent extraction of uranium from sulphuric pregnant solutions. The satisfactory results generally obtained have never required an analysis of the synergistic effects of amine combinations similar to that carried out for the organo-phosphorus compounds. In the research described the increase in the extraction power of an organic phase composed of an amine binary mixture was studied with regard to an aqueous solution from the sulphuric acid treatment of uranium ore. On the basis of the experimental results obtained, it is possible to select the best composition of the amine mixture to ensure a percentage increase in uranium recovery. Bearing in mind the tendency for the yellow-cake price to rise, the study is considered to be a useful contribution in the context of commercial products currently available on the market. (author)

Relative probabilities of the uranium isotopes for thorium x-ray emission and fluorescence of uranium x-rays

International Nuclear Information System (INIS)

Parker, J.L.

1991-01-01

Both thorium x-rays from decaying uranium isotopes and self-fluoresced uranium x-rays are prominent in high-resolution gamma-ray spectra of uranium-bearing materials. Useful application of the information carried by those x-rays has been curtailed because the probabilities of the uranium isotopes for thorium x-ray emission and for uranium x-ray fluorescence have not been known. By analyzing enrichment-meter geometry spectra from uranium oxide standards whose enrichments ranged from 0.7% to 91%, relative values, primarily, have been obtained for the probabilities of both processes. Thorium x-ray emission is very heavily dominated by 235 U. In all ordinarily occurring uranium isotopic distributions, thorium x-rays may be used as a valid 235 U signature. The probability for a thorium K α1 x-ray to be emitted in the decay of a 235 U atom is 0.048 ±0.002. In infinitely thick uranium oxide materials, the relative ratios of effectiveness for self-fluorescence, on a per unit mass basis, are approximately 234 U : 235 U : 236 U : 238 U = 1.13 : 1.00 : 0.52 : 0.028. on a per decay basis, the approximate ratios are 0.00039 : 1.00 : 0.017 : 0.18. These results imply that, contrary to what has often been stated, gamma rays are far more important than alpha particles in the self-fluorescence of uranium. Because of the importance of gamma-ray self-fluorescence, the uranium x-ray yield will be somewhat influenced by the size, shape, and composition of the materials. 4 refs., 1 fig

The role of post-ore processes in the alteration of infiltrational uranium deposits

International Nuclear Information System (INIS)

Kondrat'eva, I.A.; Bobrova, L.L.; Nesterova, M.V.

1992-01-01

Ore-bearing rocks and ores of uranium deposits that are associated with gray alluvial deposits and formed through oxidation of sedimentary beds at the end of the Jurassic, have undergone intensive alterations. The impact of hot carbonic acid solutions on infiltrational uranium deposits, along with calcite and hematite, resulted in partial dissolution of and redeposition of uranium. Uranium concentrates with newly formed Fe-bisulfides and hydroxides in the reducing stage of epigenetic alterations within a hydrochemical sulfide-gley medium, leading to changes in ore morphology. 20 refs., 7 figs., 3 tabs

Uptake of uranium by native aquatic plants: potential for bioindication and phytoremediation

Directory of Open Access Journals (Sweden)

Favas P. J. C.

2013-04-01

Full Text Available The work presented here is a part the on going study on the uraniferous geochemical province of Central Portugal in which, the use of aquatic plants as indicators of uranium contamination is being probed using aquatic plants emphasizing their potential use in the emerging phytotechnologies. Even though we have observed very low concentration of U in the fresh waters of the studied sites we found a set of vegetable species with the ability to accumulate U in concentrations which are orders of magnitude higher than the surrounding environment. We have observed that Apium nodiflorum, Callitriche stagnalis, Lemna minor and Fontinalis antipyretica accumulated significant amounts of uranium, whereas Oenanthe crocata excluded U. These results indicate substantial scope for proper radiophytoremediation and phytosociological investigation exploiting the native flora. These species show great potential for phytoremediation because they are endemic and easy to grow in their native conditions. A. nodiflorum and C. stagnalis have high bioproductivity and yield good biomass.

Assessment of nonpoint source chemical loading potential to watersheds containing uranium waste dumps associated with uranium exploration and mining, Browns Hole, Utah

Science.gov (United States)

Marston, Thomas M.; Beisner, Kimberly R.; Naftz, David L.; Snyder, Terry

2012-01-01

During August of 2008, 35 solid-phase samples were collected from abandoned uranium waste dumps, undisturbed geologic background sites, and adjacent streambeds in Browns Hole in southeastern Utah. The objectives of this sampling program were (1) to assess impacts on human health due to exposure to radium, uranium, and thorium during recreational activities on and around uranium waste dumps on Bureau of Land Management lands; (2) to compare concentrations of trace elements associated with mine waste dumps to natural background concentrations; (3) to assess the nonpoint source chemical loading potential to ephemeral and perennial watersheds from uranium waste dumps; and (4) to assess contamination from waste dumps to the local perennial stream water in Muleshoe Creek. Uranium waste dump samples were collected using solid-phase sampling protocols. Solid samples were digested and analyzed for major and trace elements. Analytical values for radium and uranium in digested samples were compared to multiple soil screening levels developed from annual dosage calculations in accordance with the Comprehensive Environmental Response, Compensation, and Liability Act's minimum cleanup guidelines for uranium waste sites. Three occupancy durations for sites were considered: 4.6 days per year, 7.0 days per year, and 14.0 days per year. None of the sites exceeded the radium soil screening level of 96 picocuries per gram, corresponding to a 4.6 days per year exposure. Two sites exceeded the radium soil screening level of 66 picocuries per gram, corresponding to a 7.0 days per year exposure. Seven sites exceeded the radium soil screening level of 33 picocuries per gram, corresponding to a 14.0 days per year exposure. A perennial stream that flows next to the toe of a uranium waste dump was sampled, analyzed for major and trace elements, and compared with existing aquatic-life and drinking-water-quality standards. None of the water-quality standards were exceeded in the stream samples.

The effect of sedimentation background of depression target stratum containing mineral in Erlian basin, Ulanqab to uranium mineralization type

International Nuclear Information System (INIS)

Kang Shihu; Jiao Yangquan; Men Hong; Kuang Wenzhan

2012-01-01

The ore bearing stratum in depression of Ulanqab contains target stratum of lower cretaceous Saihan formation, upper cretaceous Erlian formation, paleogene system etc. The uranium mineralization type which have found by now contains sandstone type, mudstone type and coal petrography. The genetic type of mineral deposit contains paleovalley-type, reformed type after superposition with sedimentation and diagenesis by sedimentation. Uranium mineralization of both the natural type and genetic type have close relationship with its ore bearing stratum. Different geological background forms different sedimentary system combination, and different sedimentary system combination forms different uranium mineralization type. (authors)

Analyses on the Bayintala basin tectonic movement control of the uranium mineralization

International Nuclear Information System (INIS)

Guo Funeng; Yao Rongyan; Cai Jianfang; Zhou Wenbo

2014-01-01

Ban Tara tectonic evolution, analysis of the relationship between depression of ore-bearing layer deposition system and epigenetic alteration and uranium mineralization, forms of uranium precipitation and enrichment in each movement stage, thus mineralization regularity in the area and oreprospecting direction. Depression experienced extensional Early Cretaceous warped fault, pull-apart sedimentary, four main stages of evolution inversion uplifting since the late Cretaceous sedimentary and. Deposition of the Tenggeer group and the Saihan group two prospecting target layer, the fan delta Tenggeer formation is sand body and Saihan group of braided river facies sand body, as the main prospecting target layer. According to the analysis of faulted depression-depression sedimentary stage of the formation of the grey clastic rocks are the important ore-bearing horizon, and inversion uplifting the strata with relatively open environment, to provide the necessary conditions for the later formation of uranium deposits. (authors)

The Outlook on Potential Uranium ISL Mining at Nyota Deposit (Tanzania)

International Nuclear Information System (INIS)

Boytsov, A.; Stander, S.; Martynenko, V.

2014-01-01

Conclusion: • The Nyota deposit is a world class deposit, which holds over 50Mlb which is potentially amenable to ISR. • Significant resources upside potential. • Initial ISL testing has yielded encouraging results, which should be followed up. • The ISR project is currently at the R&D stage, and the next steps have been identified and planned. • Technical, commercial and SHEQ challenges remains that must be overcome. • Uranium One will continue to investigate the ISR potential via a responsible, toll gated approach. • Successful testing could unlock a new ISL production region.

Correlation of uranium geology between South America and Africa

International Nuclear Information System (INIS)

1986-01-01

Acting upon the recommendation of an Advisory Group Meeting held in 1980, the IAEA organized a Working Group on the Correlation of the Uranium Geology between South America and Africa because of the tremendous geological potential for uranium and the interest showed by the Member States of the regions concerned. The report of this Working Group is now presented. The aim of this report is to provide the nuclear industry and, in particular, the countries of the region with a broad but updated outline of current development in the uranium geology and the uranium potential of Africa and South America. The scope is such that it will provide, for those not directly involved in uranium exploration in the area, a general technical summary on the regional geology and tectonics of these two continents in order that the geodynamic setting of their uranium occurrences may be correlated. With respect to the area to be covered and bearing in mind the purpose of this study, the Working Group surveyed the most relevant parts of western Gondwanaland, of which the two continents form a part. The area covered by the report extends from north of the West African Craton and the Guiana Shield to the southern end of South America and Africa; from the Amazonian Province in western Brazil and western Argentina to the central part of the West African Craton, Congo-Kasai Craton. The Andean Chain in South America and the Atlas Mountains in North Africa, which were formed by continental accretion in recent geological time and post-dated the split and drift of the two land masses, were not considered. Some of the inner portions of those cratons distant from the coastlines and for which the correlation features do not apply have also been omitted. However, certain areas of important uranium mineralization outside the main study area have been described in order to offer comparative models for future exploration elsewhere. The subject of the report is discussed under six headings: cratonic areas

Catahoula formation of the Texas coastal plain: origin, geochemical evolution, and characteristics of uranium deposits

International Nuclear Information System (INIS)

Galloway, W.E.; Kaiser, W.R.

1979-01-01

Uranium was released from volcanic glass deposited within the Catahoula through early pedogenic and diagenetic processes. Pedogenesis was the most efficient process for mobilizing uranium. Original uranium content in fresh Catahoula glass is estimated to have averaged at least 10 ppM; about 5 ppM was mobilized after deposition and made available for migration. Uranium was transported predominantly as uranyl dicarbonate ion. Chlorinity mapping reveals modern ground-water flow patterns. Six utranium deposits representative of the ores were studied. Uranium-bearing meteoric waters were reduced by pre-ore stage pyrite formed by extrinsically introduced fault-leaked sulfide or intrinsically by organic matter. Uranium was concentrated in part by adsorption on Ca-montmorillonite cutans, amorphous TiO 2 , and/or organic matter followed by uranyl reduction to U 4+ in amorphous uranous silicates. Clinoptilolite is not correlative with mineralization. Calcite is pervasive throughout host sands but shows no relationship to uranium mineralization. Presence of marcasite and uranium together at the alteration front strongly supports an acid pH during Catahoula mineralization. Maximum adsorption and minimum solubility of uranium occur at pH 6 in carbonate-rich waters. Log activity ratios of individual waters supersaturated with respect to montmorillonite, taken from montmorillonite-clinoptilolite activity diagrams, show positive correlation with uranium mineralization. High Ca 2+ , Mg 2+ , Al(OH) 4 - , and H + activities promote the formation of montmorillonite relative to clinoptilolite. High saturation ratios for montmorillonite show fair correlation with mineralization. The mineral-solution equilibria approach is a potential method of geochemical exploration. 56 figures, 8 tables

Wind Transport of Radionuclide- Bearing Dust, Peña Blanca, Chihuahua, Mexico

Science.gov (United States)

Velarde, R.; Goodell, P. C.; Gill, T. E.; Arimoto, R.

2007-05-01

This investigation evaluates radionuclide fractionation during wind erosion of high-grade uranium ore storage piles at Peña Blanca (50km north of Chihuahua City), Chihuahua, Mexico. The aridity of the local environment promotes dust resuspension by high winds. Although active operations ceased in 1983, the Peña Blanca mining district is one of Mexico`s most important uranium ore reserves. The study site contains piles of high grade ore, left loose on the surface, and separated by the specific deposits from which they were derived (Margaritas, Nopal I, and Puerto I). Similar locations do not exist in the United States, since uranium mining sites in the USA have been reclaimed. The Peña Blanca site serves as an analog for the Yucca Mountain project. Dust deposition is collected at Peña Blanca with BSNE sediment catchers (Fryrear, 1986) and marble dust traps (Reheis, 1999). These devices capture windblown sediment; subsequently, the sample data will help quantify potentially radioactive short term field sediment loss from the repository surface and determine sediment flux. Aerosols and surface materials will be analyzed and radioactivity levels established utilizing techniques such as gamma spectroscopy. As a result, we will be able to estimate how much radionuclide contaminated dust is being transported or attached geochemically to fine grain soils or minerals (e.g., clays or iron oxides). The high-grade uranium-bearing material is at secular equilibrium, thus the entire decay series is present. Of resulting interest is not only the aeolian transport of uranium, but also of the other daughter products. These studies will improve our understanding of geochemical cycling of radionuclides with respect to sources, transport, and deposition. The results may also have important implications for the geosciences and homeland security, and potential applications to public health. Funding for this project is provided in part via a NSF grant to Arimoto.

Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence. Literature Review and DOE-LM Site Surveys

International Nuclear Information System (INIS)

2016-01-01

This report on evaporite mineralization was completed as an Ancillary Work Plan for the Applied Studies and Technology program under the U.S. Department of Energy (DOE) Office of Legacy Management (LM). This study reviews all LM sites under Title I and Title II of the Uranium Mill Tailings Radiation Control Act (UMTRCA) and one Decontamination and Decommissioning site to provide (1) a summary of which sites have evaporite deposits, (2) any available quantitative geochemical and mineralogical analyses, and (3) references to relevant reports. In this study, 'evaporite' refers to any secondary mineral precipitate that occurs due to a loss of water through evaporative processes. This includes efflorescent salt crusts, where this term refers to a migration of dissolved constituents to the surface with a resulting salt crust, where 'salt' can refer to any secondary precipitate, regardless of constituents. The potential for the formation of evaporites at LM sites has been identified, and may have relevance to plume persistence issues. Evaporite deposits have the potential to concentrate and store contaminants at LM sites that could later be re-released. These deposits can also provide a temporary storage mechanism for carbonate, chloride, and sulfate salts along with uranium and other contaminants of concern (COCs). Identification of sites with evaporites will be used in a new technical task plan (TTP), Persistent Secondary Contaminant Sources (PeSCS), for any proposed additional sampling and analyses. This additional study is currently under development and will focus on determining if the dissolution of evaporites has the potential to hinder natural flushing strategies and impact plume persistence. This report provides an initial literature review on evaporites followed by details for each site with identified evaporites. The final summary includes a table listing of all relevant LM sites regardless of evaporite identification.

Uranium-Bearing Evaporite Mineralization Influencing Plume Persistence. Literature Review and DOE-LM Site Surveys

Energy Technology Data Exchange (ETDEWEB)

None, None

2016-05-01

This report on evaporite mineralization was completed as an Ancillary Work Plan for the Applied Studies and Technology program under the U.S. Department of Energy (DOE) Office of Legacy Management (LM). This study reviews all LM sites under Title I and Title II of the Uranium Mill Tailings Radiation Control Act (UMTRCA) and one Decontamination and Decommissioning site to provide (1) a summary of which sites have evaporite deposits, (2) any available quantitative geochemical and mineralogical analyses, and (3) references to relevant reports. In this study, “evaporite” refers to any secondary mineral precipitate that occurs due to a loss of water through evaporative processes. This includes efflorescent salt crusts, where this term refers to a migration of dissolved constituents to the surface with a resulting salt crust, where “salt” can refer to any secondary precipitate, regardless of constituents. The potential for the formation of evaporites at LM sites has been identified, and may have relevance to plume persistence issues. Evaporite deposits have the potential to concentrate and store contaminants at LM sites that could later be re-released. These deposits can also provide a temporary storage mechanism for carbonate, chloride, and sulfate salts along with uranium and other contaminants of concern (COCs). Identification of sites with evaporites will be used in a new technical task plan (TTP), Persistent Secondary Contaminant Sources (PeSCS), for any proposed additional sampling and analyses. This additional study is currently under development and will focus on determining if the dissolution of evaporites has the potential to hinder natural flushing strategies and impact plume persistence. This report provides an initial literature review on evaporites followed by details for each site with identified evaporites. The final summary includes a table listing of all relevant LM sites regardless of evaporite identification.

Impacts of Canada's uranium mining industry

International Nuclear Information System (INIS)

Holman, G.J.

1982-05-01

This study examines economic and environmental impacts of uranium mining in Canada and compares these impacts with those of other extractive and energy industries. The uranium industry generates taxes and royalties, income, employment, foreign exchange earnings, security of energy supply, and technological spinoffs. The indirect impacts of the industry as measured by employment and income multipliers are lower than those for other types of mining and comparable to oil and gas because of the high proportion of costs withdrawn from the economy in the form of taxes and operator margin. Social costs are primarily occupational hazards. Uranium mining probably has a lower non-health environmental impact than other mining industries due to much smaller throughputs and transportation requirements. Residents of the area surrounding the mine bear a disproportionate share of the social costs, while non-residents receive most of the benefits

Benchmarking the DFT+U method for thermochemical calculations of uranium molecular compounds and solids.

Science.gov (United States)

Beridze, George; Kowalski, Piotr M

2014-12-18

Ability to perform a feasible and reliable computation of thermochemical properties of chemically complex actinide-bearing materials would be of great importance for nuclear engineering. Unfortunately, density functional theory (DFT), which on many instances is the only affordable ab initio method, often fails for actinides. Among various shortcomings, it leads to the wrong estimate of enthalpies of reactions between actinide-bearing compounds, putting the applicability of the DFT approach to the modeling of thermochemical properties of actinide-bearing materials into question. Here we test the performance of DFT+U method--a computationally affordable extension of DFT that explicitly accounts for the correlations between f-electrons - for prediction of the thermochemical properties of simple uranium-bearing molecular compounds and solids. We demonstrate that the DFT+U approach significantly improves the description of reaction enthalpies for the uranium-bearing gas-phase molecular compounds and solids and the deviations from the experimental values are comparable to those obtained with much more computationally demanding methods. Good results are obtained with the Hubbard U parameter values derived using the linear response method of Cococcioni and de Gironcoli. We found that the value of Coulomb on-site repulsion, represented by the Hubbard U parameter, strongly depends on the oxidation state of uranium atom. Last, but not least, we demonstrate that the thermochemistry data can be successfully used to estimate the value of the Hubbard U parameter needed for DFT+U calculations.

Species of organic matter and their role in the formation of statiform uranium ores

International Nuclear Information System (INIS)

Goleva, P.K.; Uspenskij, V.A.

1983-01-01

Results of investigation of organic mather (OM) from stratiform uranium ore manifestation in sedimentary Upper Proterozoic rocks of large trough with caledonian folded base are given. Role of OM in concentration of uranium-ore formations of two ore-bearing horizons, presented by rocks of facies of large lakes (''lacustrine'') and continental deltas (''alluvial'') was clarified. Characteristics of OM of rocks of ''lacustrine'' and ''alliivial'' facies, OM types, chemical composition of OM of ''alluvial'' horizon rocks, om spectrograms and diffractograms are presented. It was established that OM of ''lacustrine'' and ''alluvial'' ore-bearing horizons are presented by different morphological and genetic types, which played different roles in t.he process of uranium ore-formation. Faneiy dispersed OM, related to the category of oxidized lower kerites is present in ''lacustrine'' horizon. Ore uranium-arsenide nuneral association substitutes OM of early generation. The latest OM generation is related to epigenetic thread veinlet of dolomite and barite. In ''alluvial'' horizon OM is present in the form of carbonized vegetative residues+ ciosely assocaating with sulfides of different metals, and is presented by high-moiecular carbocyctnc hydroxy compouds. Uranium of carbonized vegetative residues is in finely dispersed state; the form of its fixation was not established. It is proposed that the major part of uranium was sorbed by OM during sedimentogenesis

Metallogenic condition and regularity of inter layered oxidation zone-type sandstone uranium deposit in southwestern part of Turpan-Hami basin, Northwestern China

International Nuclear Information System (INIS)

Xiang Weidong; Chen Zhaobo; Chen Zuyi; Yin Jinshuang

2001-01-01

Regional geological surveying and drilling evaluation in recent years show that there are very large potential resources of sandstone-type uranium deposits in the southwestern part of Turpan-Hami basin. According to the characteristics of tectonic evolution and sedimentary cover of the basin, the evolution stages and types of the basin are divided, and the favorable development stages for the ore-bearing formation and the formation of uranium deposits in the evolution process are identified. The metallogenic conditions of uranium deposits are deeply discussed from four aspects: basic tectonics, paleoclimate evolution, hydrogeology and uranium source of the region. All these have laid an important foundation for accurate prediction and evaluation of uranium resources in this region. The research indicates that the uranium metallogeny is a process of long-term, multi-stage and pulsation. The authors try to ascertain the role of organic matter in concentrating uranium. The organic matter is of humic type in sandstone host-rock in the studied area, whose original mother material mainly belongs to terrestrial high plant. The maturity of the organic matter is very low, being in low-grade stage of thermal evolution. Correlation analysis and separation experiments show that uranium concentration is closely related with the organic matter, and the organic matter in uranium ore is mainly in the form of humic acid adsorption and humate. For this reason the total organic carbon content is often increased in the geochemical redox zone in epigenetic sandstone-type uranium deposits. It is suggested that the north of China is of great potential for sandstone-type uranium resources

Derived enriched uranium market

International Nuclear Information System (INIS)

Rutkowski, E.

1996-01-01

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

The controlling role of positive structures over the metallogenesis and emplacement of inter layer oxidation sandstone type uranium deposits

International Nuclear Information System (INIS)

Gu Kangheng; Chen Zuyi

2010-01-01

The positive structures in this paper mean the geological structures related to the occurrence of U-metallogenic zones or U-deposit such as anticlines, uplifts and uplifted fault-blocks. Occurrence features of interlayer oxidation sandstone type deposit at the southern margin of Yili basin and southwestern margin of Turpan-Hami basin, the northeastern margin of Jiudong basin illustrate that the sandstone-hosted uranium deposits, the U-mineralized sections and the uranium occurrences are always selectively emplaced on/in positive structures. The reasons for this lie in the formation mechanism of sandstone-hosted U-deposits. The positive structures raised the elevation of ore-hosting sandstone horizon and make it close to ground surface or exposed at the ground surface, which result in the infiltration of uranium and oxygen bearing groundwater from recharge area into host sandstone horizon, and the interlayer oxidation of host sandstone, as well as the dissolution and the migration of uranium in host sandstone, and the reduction mineralization at the oxidation-reduction interface. Sufficient attention should be paid to the controlling role of positive structures over the metallogenesis and emplacement of sandstone-hosted uranium deposits. They could act as an important criterion for recognizing and prognosticating potential uranium mineralized areas in uranium metallogenic zones or uranium-productive sedimentary basins. (authors)

Development of a stable uranium recovery regulatory framework for uranium recovery activities in the United States

International Nuclear Information System (INIS)

Layton, M.C.; Abrams, C.E.

2000-01-01

The U.S. Nuclear Regulatory Commission (NRC) has historically regulated operations at all uranium and thorium recovery facilities under the authority of the Atomic Energy Act of 1954, as amended. Uranium recovery facilities are those plants, or portions of facilities that process uranium- or thorium-bearing material primarily for its source material content. The uranium recovery industry expressed some concerns over several aspects of the NRC's practices, as described in the NRC's guidance documents. In April 1998, the National Mining Association submitted a report to the Commission, that identified specific concerns with NRC's current position and guidance regarding concurrent jurisdiction at uranium mills; dual regulatory authority at in situ leach facilities; the use of mill tailings impoundments for disposal of radioactive material other than 11e.(2) byproduct material; and the ability to process alternate feed material at uranium mills. The NRC staff addressed most of these concerns in two SECY (staff recommendations) papers that were concurrently provided to the Commission, along with a SECY paper on a draft rulemaking plan relating to these and other issues. The issues addressed in these papers included a new rulemaking, disposal of materials other than 11 e.(2) byproduct material, processing of materials other than natural ores, and improved efficiency for regulating in situ leach uranium facilities. The Commission issued final policy decisions on these issues and directions for NRC staff to implement those decisions in July 2000. (author)

Recycling of reprocessed uranium

International Nuclear Information System (INIS)

Randl, R.P.

1987-01-01

Since nuclear power was first exploited in the Federal Republic of Germany, the philosophy underlying the strategy of the nuclear fuel cycle has been to make optimum use of the resource potential of recovered uranium and plutonium within a closed fuel cycle. Apart from the weighty argument of reprocessing being an important step in the treatment and disposal of radioactive wastes, permitting their optimum ecological conditioning after the reprocessing step and subsequent storage underground, another argument that, no doubt, carried weight was the possibility of reducing the demand of power plants for natural uranium. In recent years, strategies of recycling have emerged for reprocessed uranium. If that energy potential, too, is to be exploited by thermal recycling, it is appropriate to choose a slightly different method of recycling from the one for plutonium. While the first generation of reprocessed uranium fuel recycled in the reactor cuts down natural uranium requirement by some 15%, the recycling of a second generation of reprocessed, once more enriched uranium fuel helps only to save a further three per cent of natural uranium. Uranium of the second generation already carries uranium-232 isotope, causing production disturbances, and uranium-236 isotope, causing disturbances of the neutron balance in the reactor, in such amounts as to make further fabrication of uranium fuel elements inexpedient, even after mixing with natural uranium feed. (orig./UA) [de

Oxidation of naturally reduced uranium in aquifer sediments by dissolved oxygen and its potential significance to uranium plume persistence

Science.gov (United States)

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

Hydrothermal uranium vein deposits in Marysvale volcanic field, Utah

International Nuclear Information System (INIS)

Rasmussen, J.D.; Cunningham, C.G.; Steven, T.A.; Rye, R.O.; Romberger, S.B.

1984-01-01

Hydrothermal uranium veins are exposed over a 300 m (980 ft) vertical range in mines of the Central Mining area, near Marysvale, Utah. They cut 23 Ma quartz monzonite, 21 Ma granite, and 19 Ma rhyolite ash-flow tuff. The veins formed 18-19 Ma, in an area 1 km (0.6 mi) across, above the center of a composite magma chamber at least 12 x 6 km across that fed a sequence of 21-14 Ma hypabyssal granitic stocks, and rhyolitic lava flows, ash-flow tuffs, and volcanic domes. Intrusive pressure uplifted and fractured the roof; molybdenite-bearing, uranium-rich glassy dikes were intruded; and a breccia pipe and uranium-bearing veins were formed. The veins appear to have been deposited near the surface above a concealed rhyolite stock, where they filled high-angle fault zones and flat-lying to concave-downward pull-apart fractures. Low pH and fO 2 hydrothermal fluids at temperatures near 200 0 C (392 0 F) permeated the fractured rocks; these fluids were rich in fluorine and potassium, and contained uranium as uranous-fluoride complexes. Fluid-wall rock interaction increased fluid pH, causing precipitation of uranium minerals. At the deepest exposed levels, wall rocks were altered to kaolinite and sericite, and uraninite, coffinite, jordisite, fluorite, molybdenite, quartz, and pyrite (with delta 34 S near zero per mil) were deposited. The fluids were progressively oxidized higher in the system; iron in the wall rocks was oxidized to hematite, and sooty uraninite and umohoite were deposited

Exploration of method determining hydrogeologic parameters of low permeability sandstone uranium deposits

International Nuclear Information System (INIS)

Ji Hongbin; Wu Liwu; Cao Zhen

2012-01-01

A hypothesis of regarding injecting test as 'anti-pumping' test is presented, and pumping test's 'match line method' is used to process data of injecting test. Accurate hydrogeologic parameters can be obtained by injecting test in the sandstone uranium deposits with low permeability and small pumping volume. Taking injecting test in a uranium deposit of Xinjiang for example, the hydrogeologic parameters of main ore-bearing aquifer were calculated by using the 'anti-pumping' hypothesis. Results calculated by the 'anti-pumping' hypothesis were compared with results calculated by water level recovery method. The results show that it is feasible to use 'anti-pumping' hypothesis to calculate the hydrogeologic parameters of main ore-bearing aquifer. (authors)

Characteristics of uranium mineralization and prospecting direction in the northeast of Ordos basin

International Nuclear Information System (INIS)

Li Xide

2012-01-01

With greenness considered a kind of symbol of ancient interformational oxidation in under subsegment of Zhiluo Group in the northeast of Ordos Basin, Zaohuohao Uranium deposit , Husiliang, Hantaimiao, and Chaidenghao Uranium mines have been founded one after the other in the exploration process of Sandstone-type uranium deposits and achieved results. The thickness in different sections of the ore bearing sand bodies, Output features in space of ancient interformational oxidation, ore body scales, and configuration are more difference. In the paper some characteristics of Uranium mineralization are summarized, and preliminary proposals are given on prospecting direction in different sections. (author)

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

International Nuclear Information System (INIS)

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

2005-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2005-07-11

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

Nuclear purity and the production of uranium (1962)

International Nuclear Information System (INIS)

Verte, P.

1962-01-01

When the production of 'nuclear grade' uranium is dealt with, it is difficult, the author of this study points out, to separate its chemical, technical, and economical bearings. While recalling the evolution of chemical processes in various countries and describing the technic of uranium manufacture in the plant of the French 'Commissariat a l'Energie Atomique' at Le Bouchet, the author outlines the effect of economical contingencies on the problems the chemists and engineer are faced with. The question of cost price is also considered here with particular attention. (author) [fr

Migration and fixation of Uranium in the surficial environment. Case histories and applications to geochemical exploration

International Nuclear Information System (INIS)

Pradier, B.

Uranium geochemistry is studied in three different test areas: surface waters, sediments, and isohumic soils. Using data from the WATEQ-type thermodynamic model the state of uranium in sampled waters is examined. Uranium is present in the oxidized state U 6 , as uranyl ion UO 2 ++ , complexed by the HPO 4 -- ion and CO 3 ion. Estimated residual uranium values, have shown the very probable existence of a non mineral support for uranium in solution, probably uranyl-fulvates. Uranium in stream-sediments is preferentially located in the fine-grained fractions. The bearing phases of the geochemical uranium, identified in the fine-grained fractions, are mainly composed by amorphous or cryptocrystallized iron oxi-hydroxide, and accessorily by fulvic (and humic) acids. Ferric phases support 60 to 75% of the total uranium. In the isohumic soils, the uranium mobility depends on the existence of highly reactive and poorly evoluted organic compounds, and amorphous or cryptocristallised ferric phases located in the first centimeters of the upper horizon. The recognition of the factors governing uranium behavior in the superficial media requires the preliminary definition of the uranium expression in waters, and that of its bearing phases in soils and stream-sediments. High uranium content in waters are not significant if related to high HCO 3 - and/or PO 4 3- content, and doubtlessly to high dissolved organic carbon content. The interest of residual uranium mapping in stream-sediment geochemistry is underlined. Data are computed by difference between natural value and the corresponding estimated value, calculated by regression taking in account the adsorbant phases content of each sample [fr

Xenon Defects in Uranium Dioxide From First Principles and Interatomic Potentials

Science.gov (United States)

Thompson, Alexander

In this thesis, we examine the defect energetics and migration energies of xenon atoms in uranium dioxide (UO2) from first principles and interatomic potentials. We also parameterize new, accurate interatomic potentials for xenon and uranium dioxide. To achieve accurate energetics and provide a foundation for subsequent calculations, we address difficulties in finding consistent energetics within Hubbard U corrected density functional theory (DFT+U). We propose a method of slowly ramping the U parameter in order to guide the calculation into low energy orbital occupations. We find that this method is successful for a variety of materials. We then examine the defect energetics of several noble gas atoms in UO2 for several different defect sites. We show that the energy to incorporate large noble gas atoms into interstitial sites is so large that it is energetically favorable for a Schottky defect cluster to be created to relieve the strain. We find that, thermodynamically, xenon will rarely ever be in the interstitial site of UO2. To study larger defects associated with the migration of xenon in UO 2, we turn to interatomic potentials. We benchmark several previously published potentials against DFT+U defect energetics and migration barriers. Using a combination of molecular dynamics and nudged elastic band calculations, we find a new, low energy migration pathway for xenon in UO2. We create a new potential for xenon that yields accurate defect energetics. We fit this new potential with a method we call Iterative Potential Refinement that parameterizes potentials to first principles data via a genetic algorithm. The potential finds accurate energetics for defects with relatively low amounts of strain (xenon in defect clusters). It is important to find accurate energetics for these sorts of low-strain defects because they essentially represent small xenon bubbles. Finally, we parameterize a new UO2 potential that simultaneously yields accurate vibrational properties

Two concepts of uranium geology in the United States of America that may be useful in Latin American uranium exploration

International Nuclear Information System (INIS)

Curry, D.L.

1981-01-01

Two concepts of the origin and deposition of uranium are described that are somewhat different from the conventional sandstone deposits of the United States of America. The first concept relates to granites as source and host rocks. Work done in the Granite Mountains of Wyoming provides considerable support for a granitic source. Calculations indicate that between 50 and 75% of the uranium has been leached from the granite to depths of nearly 400 m, and could have been source rocks for deposits in the Tertiary sandstones in adjacent basins. Areas of intense fracturing are also hosts for redeposition and concentration of uranium in granites of the Granite Mountains. The second concept describes resurgent cauldrons as source and host rocks. The development of resurgent cauldrons provides a variety of geological settings favourable for both intra-caldera deposits and deposits forming in adjacent basins. A collapsed caldera may contain a lake into which sediments from ejected material carrying uranium could be carried and into which direct contributions of uranium could come from the underlying magma. Weathering of uranium-bearing material deposited outside the caldera could provide uranium to be redeposited in conventional deposits such as roll fronts. Geological investigations carried out in the Great Basins of Utah and Nevada are cited. (author)

Remote sensing applied to copper and uranium exploration

International Nuclear Information System (INIS)

Abrams, M.; Conel, J.

1982-01-01

A summary of some of the results of the Joint NASA/Geosat Test Case copper and uranium projects is presented. Two uranium deposits in Wyoming and Utah were investigated. These sites represented a Colorado Plateau sedimentary uranium deposit, and a deposit in fractured and crushed Precambrian granite. Each of the remote sensing data sets analyzed provided some important geologic information applicable to porphyry copper and uranium exploration. Landsat and Seasat data were best suited for regional reconnaissance of structural patterns, and some lithologic/alteration mapping. The higher spatial and spectral resolution provided by the aircraft scanners allowed improved separation of geologic units and delineation of more detailed fault patterns. Overall, th TMS provided the most useful data for lithologic and alteration mapping. The presence of the wavelength band in the 2.2 μm region was found to be invaluable for identifying areas with hydrous mineral-bearing rocks

Stochastic Resonance with a Joint Woods-Saxon and Gaussian Potential for Bearing Fault Diagnosis

Directory of Open Access Journals (Sweden)

Haibin Zhang

2014-01-01

Full Text Available This work aims for a new stochastic resonance (SR model which performs well in bearing fault diagnosis. Different from the traditional bistable SR system, we realize the SR based on the joint of Woods-Saxon potential (WSP and Gaussian potential (GP instead of a reflection-symmetric quartic potential. With this potential model, all the parameters in the Woods-Saxon and Gaussian SR (WSGSR system are not coupled when compared to the traditional one, so the output signal-to-noise ratio (SNR can be optimized much more easily by tuning the system parameters. Besides, a smoother potential bottom and steeper potential wall lead to a stable particle motion within each potential well and avoid the unexpected noise. Different from the SR with only WSP which is a monostable system, we improve it into a bistable one as a general form offering a higher SNR and a wider bandwidth. Finally, the proposed model is verified to be outstanding in weak signal detection for bearing fault diagnosis and the strategy offers us a more effective and feasible diagnosis conclusion.

Uranium resources potential for Asia and the Pacific

International Nuclear Information System (INIS)

Tauchid, M.

1988-01-01

Only four countries in Asia, India, Japan, the Republic of Korea and Turkey, reported having uranium resources in response to a Nuclear Energy Agency of the OECD/International Atomic Energy Agency questionnaire circulated before preparation of the report on Uranium: Resources, Production and Demand (the 'Red Book'). The reasonably assured resources (RAR) of these countries, which are recoverable at costs of up to US $130/kg U, amount to 67,690 t U or 3% of the total for the World Outside the Centrally Planned Economies Area (WOCA). It is believed that the largest uranium resources in Asia are in China; however, no official published figures are available to substantiate this fact. Within the framework of the International Uranium Resources Evaluation Project (IUREP) it was estimated that the speculative resources (SR) for Asia and the Far East outside the Centrally Planned Economies Area (CPEA) are of the order of 300,000 t U. This is 4.7% of the total for WOCA. With the exception of Proterozoic unconformity related deposits, all types of uranium deposits and occurrences are known to exist in Asia. Most deposits are of the vein and sandstone hosted types. Several published reports indicate that deposits in China are mainly of the volcanic type and those associated with granitic intrusion. For undiscovered deposits, probably India and China have the best possibility of finding deposits of the Precambrian quartz-pebble conglomerate and Proterozoic unconformity related types. In South-East Asia the deposits most likely to be found are those associated with Mesozoic granites and those in the intramontane basin sediments adjacent to these intrusions. The less known acid volcanic type is also a possibility. Only in China, India and Pakistan does there appear to be the possibility of finding calcrete type deposits. Uranium can still be recovered as a by-product of the phosphate rocks, monazite placer deposits and carbonatite known in many parts of Asia. (author). 21 refs

Felsic magmatism and uranium deposits

International Nuclear Information System (INIS)

Cuney, Michel

2014-01-01

The strongly incompatible behaviour of uranium in silicate magmas results in its concentration in the most felsic melts and a prevalence of granites and rhyolites as primary U sources for the formation of U deposits. Despite its incompatible behavior, U deposits resulting directly from magmatic processes are quite rare. In most deposits, U is mobilized by hydrothermal fluids or ground water well after the emplacement of the igneous rocks. Of the broad range of granite types, only a few have U contents and physico-chemical properties that permit the crystallization of accessory minerals from which uranium can be leached for the formation of U deposits. The first granites on Earth, which crystallized uraninite, dated at 3.1 Ga, are the potassic granites from the Kaapval craton (South Africa) which were also the source of the detrital uraninite for the Dominion Reef and Witwatersrand quartz pebble conglomerate deposits. Four types of granites or rhyolites can be sufficiently enriched in U to represent a significant source for the genesis of U deposits: per-alkaline, high-K met-aluminous calc-alkaline, L-type peraluminous and anatectic pegmatoids. L-type peraluminous plutonic rocks in which U is dominantly hosted in uraninite or in the glass of their volcanic equivalents represent the best U source. Per-alkaline granites or syenites are associated with the only magmatic U-deposits formed by extreme fractional crystallization. The refractory character of the U-bearing minerals does not permit their extraction under the present economic conditions and make them unfavorable U sources for other deposit types. By contrast, felsic per-alkaline volcanic rocks, in which U is dominantly hosted in the glassy matrix, represent an excellent source for many deposit types. High-K calc-alkaline plutonic rocks only represent a significant U source when the U-bearing accessory minerals (U-thorite, allanite, Nb oxides) become metamict. The volcanic rocks of the same geochemistry may be

Inositol hexa-phosphate: a potential chelating agent for uranium

International Nuclear Information System (INIS)

Cebrian, D.; Tapia, A.; Real, A.; Morcillo, M.A.

2007-01-01

Chelation therapy is an optimal method to reduce the radionuclide-related risks. In the case of uranium incorporation, the treatment of choice is so far i.v infusion of a 1.4% sodium bicarbonate solution, but the efficacy has been proved to be not very high. In this study, we examine the efficacy of some substances: bicarbonate, citrate, diethylenetriamine pentaacetic acid (DTPA), ethidronate (EHBP) and inositol hexa-phosphate (phytic acid) to chelate uranium using a test developed by Braun et al. Different concentrations of phytic acid, an abundant component of plant seeds that is widely distributed in animal cells and tissues in substantial levels, were tested and compared to the same concentrations of sodium citrate, bicarbonate, EHBP and DTPA. The results showed a strong affinity of inositol hexa-phosphate for uranium, suggesting that it could be an effective chelating agent for uranium in vivo. (authors)

Uranium resources in New Mexico

International Nuclear Information System (INIS)

McLemore, V.T.; Chenoweth, W.L.

1989-01-01

For nearly three decades (1951-1980), the Grants uranium district in northwestern New Mexico produced more uranium than any other district in the world. The most important host rocks containing economic uranium deposits in New Mexico are sandstones within the Jurassic Morrison Formation. Approximately 334,506,000 lb of U 3 O 8 were produced from this unit from 1948 through 1987, accounting for 38% of the total uranium production from the US. All of the economic reserves and most of the resources in New Mexico occur in the Morrison Formation. Uranium deposits also occur in sandstones of Paleozoic, Triassic, Cretaceous, Tertiary, and Quaternary formations; however, only 468,680 lb of U 3 O 8 or 0.14% of the total production from New Mexico have been produced from these deposits. Some of these deposits may have a high resource potential. In contrast, almost 6.7 million lb of U 3 O 8 have been produced from uranium deposits in the Todilto Limestone of the Wanakah Formation (Jurassic), but potential for finding additional economic uranium deposits in the near future is low. Other uranium deposits in New Mexico include those in other sedimentary rocks, vein-type uranium deposits, and disseminated magmatic, pegmatitic, and contact metasomatic uranium deposits in igneous and metamorphic rocks. Production from these deposits have been insignificant (less than 0.08% of the total production from New Mexico), but there could be potential for medium to high-grade, medium-sized uranium deposits in some areas. Total uranium production from New Mexico from 1948 to 1987 amounts to approximately 341,808,000 lb of U 3 O 8 . New Mexico has significant uranium reserves and resources. Future development of these deposits will depend upon an increase in price for uranium and lowering of production costs, perhaps by in-situ leaching techniques

The uranium potential of the continental Cretaceous of Patagonia

International Nuclear Information System (INIS)

Olsen, H.; Berizzo, J.

1980-01-01

The geological features of the fluvial sedimentation of the Cretaceous of Patagonia - the Grupo Chubut Formation in the provinces of Chubut and Santa Cruz, underlined this environment as one of high favourability for discovering uranium deposits. The area has been explored by the CNEA who found two outstanding levels of fluvial sediments that are today the target of further studies to find new deposits. The general geological features are given, together with the results of the exploration up to date, distribution of radiometric anomalies, deposits discovered and an estimation of the uraniferous potential of the Formation. (author)

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

Energy Technology Data Exchange (ETDEWEB)

Israelsson, A., E-mail: axel.israelsson@liu.se [Department of Medical and Health Sciences, Linköping University, 58183 Linköping (Sweden); Eriksson, M. [Swedish Radiation Safety Authority, 17116 Stockholm (Sweden); Pettersson, H.B.L. [Department of Radiation Physics, Linköping University, 58183 Linköping (Sweden); Department of Medical and Health Sciences, Linköping University, 58183 Linköping (Sweden)

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. - Highlights: • Uranium at the fg level was detectable and the uranium distribution in single hair shafts was derived. • The uranium is located peripherally on the shafts in what seems to be a layer of approximately 10-15 μm thickness. • Uranium bearing particles were found on hairs that had not been washed.

Potential paths for male-mediated gene flow to and from an isolated grizzly bear population

Science.gov (United States)

Peck, Christopher P.; van Manen, Frank T.; Costello, Cecily M.; Haroldson, Mark A.; Landenburger, Lisa; Roberts, Lori L.; Bjornlie, Daniel D.; Mace, Richard D.

2017-01-01

For several decades, grizzly bear populations in the Greater Yellowstone Ecosystem (GYE) and the Northern Continental Divide Ecosystem (NCDE) have increased in numbers and range extent. The GYE population remains isolated and although effective population size has increased since the early 1980s, genetic connectivity between these populations remains a long-term management goal. With only ~110 km distance separating current estimates of occupied range for these populations, the potential for gene flow is likely greater now than it has been for many decades. We sought to delineate potential paths that would provide the opportunity for male-mediated gene flow between the two populations. We first developed step-selection functions to generate conductance layers using ecological, physical, and anthropogenic landscape features associated with non-stationary GPS locations of 124 male grizzly bears (199 bear-years). We then used a randomized shortest path (RSP) algorithm to estimate the average number of net passages for all grid cells in the study region, when moving from an origin to a destination node. Given habitat characteristics that were the basis for the conductance layer, movements follow certain grid cell sequences more than others and the resulting RSP values thus provide a measure of movement potential. Repeating this process for 100 pairs of random origin and destination nodes, we identified paths for three levels of random deviation (θ) from the least-cost path. We observed broad-scale concordance between model predictions for paths originating in the NCDE and those originating in the GYE for all three levels of movement exploration. Model predictions indicated that male grizzly bear movement between the ecosystems could involve a variety of routes, and verified observations of grizzly bears outside occupied range supported this finding. Where landscape features concentrated paths into corridors (e.g., because of anthropogenic influence), they typically

Preliminary report on the geology of the Lakeview uranium area, Lake County, Oregon

International Nuclear Information System (INIS)

Walker, G.W.

1980-01-01

This study was directed partly toward determining uranium resources, but, more specifically toward establishing the geochemical relations of uranium and other metals with rhyolite bodies in the Lakeview uranium area and to compare these bodies with similar rhyolitic bodies outside the area. The ultimate goal of this work was to determine, if possible, the uranium resource potential of these kinds of rocks over an area of several thousand square kilometers and to apply knowledge gained from this resource assessment to similar terranes within the Northern Basin and Range Province. The regional evaluation is still in progress, and its results will be reported at some appropriate time in the future. To these ends a review was made of previous geologic studies of the area and of the uranium deposits themselves, and some regional geologic mapping was done at a scale of 1:24,000. A geologic map was prepared of an area covering about 450 km 2 (approx. 170 mi 2 ), more or less centered on the White King and Lucky Lass mines and on the major cluster of uranium-bearing rhyolites, and some geologic reconnaissance and attendant sampling of rhyolite intrusives and extrusives well outside the Lakeview uranium area were completed. Isotopic dates were obtained on some units and magnetic polarity characteristics were determined on many units in order to more firmly establish age and stratigraphic relations of the diverse volcanic and volcaniclastic units of the region. Major oxide chemistry and selected trace-element chemistry were obtained on those rhyolitic units suitable for analysis in order to establish distribution patterns for uranium, as well as several other metals, in the rhyolitic rocks of the Lakeview uranium area and to make regional correlations with other analyzed rhyolitic rocks

Analytical electron microscopy characterization of uranium-contaminated soils from the Fernald Site, FY1993 report

International Nuclear Information System (INIS)

Buck, E.C.; Cunnane, J.C.; Brown, N.R.; Dietz, N.L.

1994-10-01

A combination of optical microscopy, scanning electron microscopy with backscattered electron detection (SEM/BSE), and analytical electron microscopy (AEM) is being used to determine the nature of uranium in soils from the Fernald Environmental Management Project. The information gained from these studies is being used to develop and test remediation technologies. Investigations using SEM have shown that uranium is contained within particles that are typically 1 to 100 μm in diameter. Further analysis with AEM has shown that these uranium-rich regions are made up of discrete uranium-bearing phases. The distribution of these uranium phases was found to be inhomogeneous at the microscopic level

Uranium-bearing metasediment and granite in the Tasermiut area, South Greenland

International Nuclear Information System (INIS)

Leth Nielsen, B.; Tukiainen, T.

1981-01-01

Regional exploration for uranium was carried out in South Greenland in 1979 and 1980. From the planning stage the area between the fjords Tasermiut and Soendre Sermilik was considered a favourable target because deposits from geological environments of similar age, structure and lithology are known, e.g. the Makkovik Bay area in Labrador. The deposits sought were mainly pegmatitic or vein type deposits related to a Proterozoic unconformity. During the South Greenland uranium exploration project the area was covered in 1979 by a regional reconnaissance gamma-spectrometric survey and by drainage geochemistry (stream sediments and stream waters). Several areas of anomalous radioactivity were recorded, and on the basis of this and short field visit in 1979 it was decided to undertake a more systematic follow-up in 1980. The preliminary results of this work are reported below. (author)

Influence of uranium hydride oxidation on uranium metal behaviour

International Nuclear Information System (INIS)

Patel, N.; Hambley, D.; Clarke, S.A.; Simpson, K.

2013-01-01

This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

Influence of uranium hydride oxidation on uranium metal behaviour

Energy Technology Data Exchange (ETDEWEB)

Patel, N.; Hambley, D. [National Nuclear Laboratory (United Kingdom); Clarke, S.A. [Sellafield Ltd (United Kingdom); Simpson, K.

2013-07-01

This work addresses concerns that the rapid, exothermic oxidation of active uranium hydride in air could stimulate an exothermic reaction (burning) involving any adjacent uranium metal, so as to increase the potential hazard arising from a hydride reaction. The effect of the thermal reaction of active uranium hydride, especially in contact with uranium metal, does not increase in proportion with hydride mass, particularly when considering large quantities of hydride. Whether uranium metal continues to burn in the long term is a function of the uranium metal and its surroundings. The source of the initial heat input to the uranium, if sufficient to cause ignition, is not important. Sustained burning of uranium requires the rate of heat generation to be sufficient to offset the total rate of heat loss so as to maintain an elevated temperature. For dense uranium, this is very difficult to achieve in naturally occurring circumstances. Areas of the uranium surface can lose heat but not generate heat. Heat can be lost by conduction, through contact with other materials, and by convection and radiation, e.g. from areas where the uranium surface is covered with a layer of oxidised material, such as burned-out hydride or from fuel cladding. These rates of heat loss are highly significant in relation to the rate of heat generation by sustained oxidation of uranium in air. Finite volume modelling has been used to examine the behaviour of a magnesium-clad uranium metal fuel element within a bottle surrounded by other un-bottled fuel elements. In the event that the bottle is breached, suddenly, in air, it can be concluded that the bulk uranium metal oxidation reaction will not reach a self-sustaining level and the mass of uranium oxidised will likely to be small in relation to mass of uranium hydride oxidised. (authors)

Sunflower: A potential fructan-bearing crop?

Directory of Open Access Journals (Sweden)

Giselle eMartinez-Noel

2015-10-01

Full Text Available Grain filling in sunflower (Helianthus annuus L. mainly depends on actual photosynthesis, being the contribution of stored reserves in stems (sucrose, hexoses and starch rather low. Drought periods during grain filling often reduce yield. Increasing the capacity of stem to store reserves could help to increase grain filling and yield stability in dry years. Fructans improve water uptake in soils at low water potential, and allow the storage of large amount of assimilates per unit tissue volume that can be readily remobilized to grains. Sunflower is a close relative to Jerusalem artichoke (Helianthus tuberosus L., which accumulates large amounts of fructan (inulin in tubers and true stems. The reason why sunflower does not accumulate fructans is obscure. Through a bioinformatics analysis of a sunflower transcriptome database, we found sequences that are homologous to dicotyledon and monocotyledon fructan synthesis genes. A HPLC analysis of stem sugar composition revealed the presence of low amounts of 1-kestose, while a drastic enhancement of endogenous sucrose levels by capitulum removal did not promote 1-kestose accumulation. This suggests that the regulation of fructan synthesis in this species may differ from the currently best known model, mainly derived from research on Poaceae, where sucrose acts as both a signaling molecule and substrate, in the induction of fructan synthesis. Thus, sunflower might potentially constitute a fructan-bearing species, which could result in an improvement of its performance as a grain crop. However, a large effort is needed to elucidate how this up to now unsuspected potential could be effectively

Airborne uranium, its concentration and toxicity in uranium enrichment facilities

International Nuclear Information System (INIS)

Thomas, J.; Mauro, J.; Ryniker, J.; Fellman, R.

1979-02-01

The release of uranium hexafluoride and its hydrolysis products into the work environment of a plant for enriching uranium by means of gas centrifuges is discussed. The maximum permissible mass and curie concentration of airborne uranium (U) is identified as a function of the enrichment level (i.e., U-235/total U), and chemical and physical form. A discussion of the chemical and radiological toxicity of uranium as a function of enrichment and chemical form is included. The toxicity of products of UF 6 hydrolysis in the atmosphere, namely, UO 2 F 2 and HF, the particle size of toxic particulate material produced from this hydrolysis, and the toxic effects of HF and other potential fluoride compounds are also discussed. Results of an investigation of known effects of humidity and temperature on particle size of UO 2 F 2 produced by the reaction of UF 6 with water vapor in the air are reported. The relationship of the solubility of uranium compounds to their toxic effects was studied. Identification and discussion of the standards potentially applicable to airborne uranium compounds in the working environment are presented. The effectiveness of High Efficiency Particulate (HEPA) filters subjected to the corrosive environment imposed by the presence of hydrogen fluoride is discussed

The ignitability potential of uranium {open_quotes}roaster oxide{close_quotes}

Energy Technology Data Exchange (ETDEWEB)

Stakebake, J.L.

1994-11-01

The oxidation of uranium to form Uranium `roaster oxide` was investigated with respect to concerns of unreacted metal remaining in the roaster oxide matrix. It was found that ignition of unreacted uranium chips in the roaster oxide as synthesized is unlikely under normal storage conditions.

Chapter 6. Uranium extraction possibilities from natural uranium-bearing waters of complex salt composition. 6.2. Technology for uranium extraction from brine with a high content of ion-chlorine

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

2012-01-01

Present article is devoted to technology for uranium extraction from brine with a high content of ion-chlorine. The content of basic anions and cations in lake waters of Sasik-Kul deposit was defined. Results of X-ray spectral analysis of salt residual after water evaporation from Sasik-Kul lake was discussed. Investigations revealed that uranium extraction from brines containing ion-chlorine is possible. The developed basic process flow diagram of uranium extraction from Sasik-Kul Lake' brine consists of the following basic stages: evaporation, leaching, catching of formed gases (HCl), sorption, desorption, deposition, drying and tempering.

Chapter 6. Uranium extraction possibilities from natural uranium-bearing waters of complex salt composition. 6.2. Technology for uranium extraction from brine with a high content of ion-chlorine

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.

2011-01-01

Present article is devoted to technology for uranium extraction from brine with a high content of ion-chlorine. The content of basic anions and cations in lake waters of Sasik-Kul deposit was defined. Results of X-ray spectral analysis of salt residual after water evaporation from Sasik-Kul lake was discussed. Investigations revealed that uranium extraction from brines containing ion-chlorine is possible. The developed basic process flow diagram of uranium extraction from Sasik-Kul Lake' brine consists of the following basic stages: evaporation, leaching, catching of formed gases (HCl), sorption, desorption, deposition, drying and tempering.

Metallogenic geologic conditions and prospecting direction of sandstone type uranium mineralizations in Yili basin of Xinjiang

International Nuclear Information System (INIS)

Chen Daisheng; Wang Ruiying; Li Shengxiang; Zhang Kefang

1994-09-01

Yili basin is a Mesozoic down-warped basin superimposed on the late Paleozoic volcanic taphrogenic basin. Uranium mineralizations are hosted in the Middle-Lower Jurassic coal-bearing series. The depositions environment in the basin is turbulent in the east and relatively stable in the west. It is characterized by coarse-grained sequence with thin thickness in the eastern part and fine-grained with thick thickness in the western part. On the analytical basis of sedimentary facies indices, it is the first time to present a sedimentary model of 'alluvial fan-braided stream-(narrow) lakeshore delta-lacustrine facies and marsh facies' for the coal-bearing series. The authors have summarized the basic geologic features of U-mineralizations in the interlayer oxidation zone, analyzed the difference and cause of U-mineralizations between the south and north, as well as the east and west. The genetic mechanism of U-mineralizations in the basin is discussed. Finally, seven items of geologic prerequisites for the formation of in-situ leachable sandstone type uranium deposits have been suggested and the potential of sandstone type U-mineralizations in the basin has been evaluated. Four promising target areas are selected

Geochemical study for primary dispersion of trace elements in uranium bearing black slates of the Ogcheon Group, Korea

International Nuclear Information System (INIS)

Kim, O.B.

1980-01-01

Total 145 boring core samples of Deogpyongri, Geosan and Mogsori, Geumsan in Ogcheon Group have been collected and analyzed for uranium and trace elements such as lead, zinc, copper, chromium, cadmium, vanadium and mloybdenium. All the data of the elments analyzed have been processed statistically by computer in order to estimate the correlation co-efficient between elements. The vertical distribution pattern of trace elements has been discussed. The results obtained are summarized as follows: Uranium has high correlation co-efficients with vanadium and molybdenium. And the last two can be used as indicator elements for the geochemical prospecting of uranium. The occurrence of uranium is closely related with the carbonaceous material in boring core of Ogcheon Group. Considering the vertical distribution pattern of uranium, it can't be said that the epigenetic uranium absorption to the carbonaceous material is in progress. The uranium minerals in the carbonanceous material must be correctly defined to resolve the genetic problems of uranium deposit in Ogcheon Group. (Author)

Federal and state permits required to open a new uranium mine with comments on uranium development on Indian reservations

International Nuclear Information System (INIS)

Root, T.E.; Whisler, J.S.

1976-01-01

Three federally related problems are discussed: the environmental impact statement, water discharge permits, and access. A cookbook approach to the permitting process is given as it exists in Wyoming, Utah, New Mexico, and Arizona. The question of jurisdiction is dealt with by using a case study approach to illustrate how jurisdiction bears on uranium development on Indian reservations

Epigenetic zonation and fluid flow history of uranium-bearing fluvial aquifer systems, south Texas uranium province. Report of Investigations No. 119

International Nuclear Information System (INIS)

Galloway, W.E.

1982-01-01

The Oligocene-Miocene fluvial uranium host aquifers of the South Texas uranium province were deposited principally as syndepositionally oxidized sands and muds. Early intrusion of reactive sulfide-enriched waters produced large intrastratal islands of epigenetic sulfidic alteration, which contain isotopically heavy pyrite exhibiting unique replacement textures. The only known reservoir containing such sulfidic waters is the deeply buried Mesozoic carbonate section beneath the thick, geopressured Tertiary basin fill. Thermobaric waters were expulsed upward along major fault zones into shallow aquifers in response to a pressure head generated by compaction and dehydration in the abyssal ground-water regime. Vertical migration of gaseous hydrogen sulfide was less important. Repeated flushing of the shallow aquifers by oxidizing meteoric waters containing anomalous amounts of uranium, selenium, and molybdenum alternating with sulfidic thermobaric waters caused cyclic precipitation and oxidation of iron disulfide. Uranium deposits formed along hydrologically active oxidation interfaces separating epigenetic sulfidic and epigenetic oxidation zones. Multiple epigenetic events are recorded in imperfectly superimposed, multiple mineralization fronts, in regional and local geometric relations between different alteration zones, and in the bulk matrix geochemistry and mineralogy of alteration zones. The dynamic mineralization model described in this report may reflect processes active in many large, depositionally active basins

The uranium ore deposits in Ciudad Rodrigo Phyllites. about the possibility of new deposits

International Nuclear Information System (INIS)

Mingarro Martin, E.; Marin Benavente, C.

1969-01-01

The main features of the genesis of uranium deposits of the Fe mine type, are discussed in this paper. Pitchblende ore is related with phyllites bearing organic material and with geomorphological level, fossilized by eocene sediments. As a result, new uranium ore deposits are possible under Ciudad Rodrigo tertiary basin, tertiary cover depth being little more than three hundred feet. (Author)

Itaconic acid based potential sorbent for uranium recovery

International Nuclear Information System (INIS)

Kalyan, Y.; Naidu, G.R.K.; Das, Sadananda; Pandey, A.K.; Reddy, A.V.R.

2010-01-01

Cross-linked hydrogels and adsorptive membranes containing Itaconic acid, Acrylamide, Penta erythritol tetra acrylate and α, α-dimethyl- α-phenyl aceto phenone were prepared by UV-initiated bulk polymerization. These hydrogels and adsorptive membranes were characterized for pH uptake, sorption and desorption kinetics and selectivity towards uranium. The sorption ability of the sorbents towards uranyl ion was thoroughly examined. The developed itaconic acid based sorbents were evaluated for the recovery of uranium from lean sources like sea water. (author)

Eldorado Port Hope refinery - uranium production (1933-1951)

International Nuclear Information System (INIS)

Arsenault, J.E.

2008-01-01

Since the discovery of pitchblende in 1930 by Gilbert LaBine at Great Bear Lake (GBL), North West Territories, uranium has played a central role in the growth of the Canadian mining sector and it in turn has propelled the country into it's present position as the world's top uranium producer. The rich ore mined there was used originally by Eldorado Gold Mines Limited to build a business based on the extraction of radium, which was selling at $70,000 a gram at the time, and silver which was present in the ore in commercial amounts. The mine site on GBL became known as Port Radium. In 1933 Eldorado brought a refinery on-line at Port Hope, Ontario nearly 4,000 miles away from the mine, and began to produce radium, silver and uranium products. Initially uranium played a minor role in the business and the products were sold into the ceramics industry to manufacture a variety of crockery with long-lasting colours. In addition, there were sales and loans of uranium products to research laboratories that were exploring nuclear energy for possible use in weapons and power generation, as the potential for this was clearly understood from 1939 onwards. These laboratories included the National Research Council (George Laurence), Columbia University (Enrico Fermi) and International Chemical Industries (J.P. Baxter). With the beginning of World War II the radium business suffered from poor sales and by 1940 the mine was closed but the refinery continued operation, using accumulated stockpiles. By 1942 uranium had become a strategic material, the mine was reopened, and the refinery began to produce large quantities of uranium oxide destined for The Manhattan Project. As events unfolded Eldorado was unable to produce sufficient ore from GBL so that a large quantity of ore from the Belgian Congo was also processed at Port Hope. Ultimately, as a result of the efforts of this enterprise, World War II was finally ended by use of atomic weapons. After World War II the refinery

Eldorado Port Hope refinery - uranium production (1933-1951)

Energy Technology Data Exchange (ETDEWEB)

Arsenault, J.E

2008-03-15

Since the discovery of pitchblende in 1930 by Gilbert LaBine at Great Bear Lake (GBL), North West Territories, uranium has played a central role in the growth of the Canadian mining sector and it in turn has propelled the country into it's present position as the world's top uranium producer. The rich ore mined there was used originally by Eldorado Gold Mines Limited to build a business based on the extraction of radium, which was selling at $70,000 a gram at the time, and silver which was present in the ore in commercial amounts. The mine site on GBL became known as Port Radium. In 1933 Eldorado brought a refinery on-line at Port Hope, Ontario nearly 4,000 miles away from the mine, and began to produce radium, silver and uranium products. Initially uranium played a minor role in the business and the products were sold into the ceramics industry to manufacture a variety of crockery with long-lasting colours. In addition, there were sales and loans of uranium products to research laboratories that were exploring nuclear energy for possible use in weapons and power generation, as the potential for this was clearly understood from 1939 onwards. These laboratories included the National Research Council (George Laurence), Columbia University (Enrico Fermi) and International Chemical Industries (J.P. Baxter). With the beginning of World War II the radium business suffered from poor sales and by 1940 the mine was closed but the refinery continued operation, using accumulated stockpiles. By 1942 uranium had become a strategic material, the mine was reopened, and the refinery began to produce large quantities of uranium oxide destined for The Manhattan Project. As events unfolded Eldorado was unable to produce sufficient ore from GBL so that a large quantity of ore from the Belgian Congo was also processed at Port Hope. Ultimately, as a result of the efforts of this enterprise, World War II was finally ended by use of atomic weapons. After World War II the

Distribution characteristics of interlayer oxidation zone and its relationship with sedimentary facies and uranium mineralization in QJD uranium deposit, Songliao basin, NE China

International Nuclear Information System (INIS)

Chen Xiaolin; Xiang Weidong; Li Tiangang; Fang Xiheng; Xia Yuliang; Pang Yaqing; Zheng Jiwei; Zhang Mingyu; Zhang Zegui; Tian Shifeng

2006-01-01

QJD uranium deposit is a sandstone-type uranium deposit with the special shape of the interlayer oxidation zone. After studying the palaeoclimate condition and sedimentation of host sandstones, contrasting drilling cross sections, this paper suggests that primary colors of host sandstones are mostly in gray, red and yellow colors of sandstones are the result of oxidation alteration. According to the positions of drill holes with red and yellow alteration sandstones, the plane distribution of oxidation roll fronts of the Upper and Lower Member of Yaojia Formation are delineated. By contrasting the plane distribution of oxidation fronts and sedimentary facies, it can be found that oxidation fronts are obviously controlled by interchannel fine-grained sediments. The movement of uranium-bearing oxidizing groundwater can be obstructed by interchannel sediments and pelitic interbeds of host sandstones. As a result, redox interface will be developed and uranium can be concentrated in neighbouring sandstones. (authors)

On the characteristics of metallotect features and origin of Chanziping uranium deposit

International Nuclear Information System (INIS)

Kang Zili; Liu Haiying

1991-01-01

Chanziping Uranium Deposit is one of the representative uranium deposits which lie in the Lower Cambrian Qingxi Formation in China, Chiefly composed of black shale formation. The mineralization is largely controlled by the U-rich strata and bedding-plane faults. The former is the source of ore and ore-bearing wallrock; the latter controls the distributions of ore bodies, and is the source of force for remobilization, and mineralization of uranium and other metallogenetic elements. The formation of this deposit approximately undergoes the following 4 stages: 1. Preliminary enrichment of sedimentary uranium source layer in the Qingxi Formation; 2. Further uranium enrichment during the deformation and metamorphism of strata; 3. Formation of hydrothermal (thermal water) uranium deposit (main metallogenetic epoch) due to dynamic differentation and thermodynamic metamorphism; 4. Formation of rich multiple ore bodies due to the secondary leaching and enrichment. Then, the deposit, which contains strata-bound features, becomes a polygenetic compound uranium deposit. These characteristics may be used as the rules for searching for uranium deposits of this type

Study of a proposed method of uranium concentration determination using low-energy γ-ray spectroscopy

International Nuclear Information System (INIS)

Rossiter, K.G.; Tang, J.C.N.

1980-01-01

The problems associated with in-situ uranium assaying are discussed, especially in relation to the secular disequilibrium between the parent uranium and its radioactive daughters. A detailed study of the gamma-spectra of some natural uranium bearing ore and mineral samples was performed using a high resolution Ge(Li) detector. A method of spectroscopic analysis of the low energy gamma-rays of U-238 and its daughter Th-234, using a proportional counter and a series of Ross filters, was found to be feasible. The application of such a method to uranium assaying in natural ore bodies is discussed

The U.S. uranium industry

International Nuclear Information System (INIS)

Glasier, G.E.

1987-01-01

This presentation concentrates on the future of the U.S. uranium industry in light of potential embargo legislation and the uranium producers' lawsuit. The author discusses several possible resolutions which would lead to a more certain and possibly stable uranium market. The probability of one or more Six possible actions which would effect the uranium industry are addressed

An Assessment of Gas Foil Bearing Scalability and the Potential Benefits to Civilian Turbofan Engines

Science.gov (United States)

Bruckner, Robert J.

2010-01-01

Over the past several years the term oil-free turbomachinery has been used to describe a rotor support system for high speed turbomachinery that does not require oil for lubrication, damping, or cooling. The foundation technology for oil-free turbomachinery is the compliant foil bearing. This technology can replace the conventional rolling element bearings found in current engines. Two major benefits are realized with this technology. The primary benefit is the elimination of the oil lubrication system, accessory gearbox, tower shaft, and one turbine frame. These components account for 8 to 13 percent of the turbofan engine weight. The second benefit that compliant foil bearings offer to turbofan engines is the capability to operate at higher rotational speeds and shaft diameters. While traditional rolling element bearings have diminished life, reliability, and load capacity with increasing speeds, the foil bearing has a load capacity proportional to speed. The traditional applications for foil bearings have been in small, lightweight machines. However, recent advancements in the design and manufacturing of foil bearings have increased their potential size. An analysis, grounded in experimentally proven operation, is performed to assess the scalability of the modern foil bearing. This analysis was coupled to the requirements of civilian turbofan engines. The application of the foil bearing to larger, high bypass ratio engines nominally at the 120 kN (approx.25000 lb) thrust class has been examined. The application of this advanced technology to this system was found to reduce mission fuel burn by 3.05 percent.

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

Science.gov (United States)

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.

A review of uranium corrosion by hydrogen and the formation of uranium hydride

OpenAIRE

Banos, A.; Harker, N. J.; Scott, T. B.

2018-01-01

Uranium hydride (UH3) is the direct product of the reaction between uranium metal and gaseous hydrogen. In the context of uranium storage, this corrosion reaction is considered deleterious, not just because the structure of the metal may become significantly degraded but also because the resulting hydride is pyrophoric and therefore potentially flammable in air if present in significant quantity. The current review draws from the literature surrounding the uranium-hydrogen system accrued over...

Uranium from phosphates in the United Arab Republic

Energy Technology Data Exchange (ETDEWEB)

NONE

1959-04-15

In response to a request from the UAR Government, the IAEA sent a Soviet expert, to make an on-the-spot study of data on the mining and processing of phosphates in the UAR and to examine the possibility of recovering uranium from the phosphate ores. In his report to the IAEA Director General, he has listed the following conclusions: 1.The uranium content of run-of-the-mine phosphoric ores in the United Arab Republic is very low and the recovery of uranium from them is therefore hardly likely to be an economic proposition. 2. It is essential to press on with prospecting work in order to discover richer uranium deposits and regions of phosphoritic ores. 3. It is essential to organize scientific research work on the recovery of uranium from the various types of uranium-bearing phosphoritic ores in the United Arab Republic, using mechanical concentrating methods and chemical processing methods. 4. The Agency could assist in carrying out this work either by sending as many technicians as a required to help in planning and undertaking the research work in the UAR or by getting appropriate Member States to carry out this work on preliminary samples of ore with the participation of representatives of the UAR

The weak acid resin process: a dustless conversion route for the synthesis of americium bearing-blanket precursors

International Nuclear Information System (INIS)

Picart, S.; Gauthe, A.; Parant, P.; Remy, E.; Jobelin, I.; Pomared, J.M.; Grangaud, P.; Dauby, J.; Delahaye, T.; Caisso, M.; Bataille, M.; Bayle, J.P.; Frost, C.; Delage, C.; Martin, C.L.; Ayral, E.

2016-01-01

Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Conversion and fabrication processes are currently developed to make those materials in the form of dense and homogeneous oxide ceramic pellets or dense granulates incorporating uranium and americium. Their development points out the need of a simplified and optimized process which could lower hazards linked to dust generation of highly contaminating and irradiating compounds and facilitate material transfer in remote handling operations. This reason motivated the development of innovative 'dustless' route such as the Weak Acid Resin route (WAR) which provides the oxide precursors in the form of sub-millimeter-sized microspheres with optimal flowability and limits dust generation during conversion and fabrication steps. This study is thus devoted to the synthesis of mixed uranium-americium oxide microspheres by the WAR process and to the characterization of such precursors. This work also deals with their application to the fabrication of dense or porous pellets and with their potential use as dense spherules to make Sphere-Pac fuel. (authors)

The weak acid resin process: a dustless conversion route for the synthesis of americium bearing-blanket precursors

Energy Technology Data Exchange (ETDEWEB)

Picart, S.; Gauthe, A.; Parant, P.; Remy, E.; Jobelin, I.; Pomared, J.M.; Grangaud, P.; Dauby, J.; Delahaye, T. [CEA, Centre de Marcoule, DEN/MAR/DRCP, F-30207 Bagnols-sur-Ceze (France); Caisso, M.; Bataille, M.; Bayle, J.P. [CEA, Centre de Marcoule, DEN/MAR/DTEC, F-30207 Bagnols-sur-Ceze (France); Frost, C. [CEA, Centre de Marcoule, DEN/MAR/DRCP, F-30207 Bagnols-sur-Ceze (France); Institut Europeen des Membranes, CNRS-ENSCM-UM, CC47, University of Montpellier, F-34095 Montpellier (France); Delage, C. [CEA, Centre de Cadarache, DEN/CAD/DEC, Saint-Paul-lez-Durance (France); Martin, C.L. [Univ. Grenoble Alpes, CNRS, SIMAP, F-38000 Grenoble (France); Ayral, E. [Institut Europeen des Membranes, CNRS-ENSCM-UM, CC47, University of Montpellier, F-34095 Montpellier (France)

2016-07-01

Mixed uranium-americium oxides are one of the materials envisaged for Americium Bearing Blankets dedicated to transmutation in fast neutron reactors. Conversion and fabrication processes are currently developed to make those materials in the form of dense and homogeneous oxide ceramic pellets or dense granulates incorporating uranium and americium. Their development points out the need of a simplified and optimized process which could lower hazards linked to dust generation of highly contaminating and irradiating compounds and facilitate material transfer in remote handling operations. This reason motivated the development of innovative 'dustless' route such as the Weak Acid Resin route (WAR) which provides the oxide precursors in the form of sub-millimeter-sized microspheres with optimal flowability and limits dust generation during conversion and fabrication steps. This study is thus devoted to the synthesis of mixed uranium-americium oxide microspheres by the WAR process and to the characterization of such precursors. This work also deals with their application to the fabrication of dense or porous pellets and with their potential use as dense spherules to make Sphere-Pac fuel. (authors)

Enhanced fuel production in thorium/lithium hybrid blankets utilizing uranium multipliers

International Nuclear Information System (INIS)

Pitulski, R.H.

1979-10-01

A consistent neutronics analysis is performed to determine the effectiveness of uranium bearing neutron multiplier zones on increasing the production of U 233 in thorium/lithium blankets for use in a tokamak fusion-fission hybrid reactor. The nuclear performance of these blankets is evaluated as a function of zone thicknesses and exposure by using the coupled transport burnup code ANISN-CINDER-HIC. Various parameters such as U 233 , Pu 239 , and H 3 production rates, the blanket energy multiplication, isotopic composition of the fuels, and neutron leakages into the various zones are evaluated during a 5 year (6 MW.y.m -2 ) exposure period. Although the results of this study were obtained for a tokomak magnetic fusion device, the qualitative behavior associated with the use of the uranium bearing neutron multiplier should be applicable to all fusion-fission hybrids

Uranium potential inventory on systematic prospection stage at Jumbang I sector, West Kalimantan

International Nuclear Information System (INIS)

Widodo, Manto; Rusmadi; Widito, P.; Marzuki, Anang; Sularto, Priyo

2002-01-01

At Jumbang I sector, West Kalimantan was discovered a uranium mineralization as outcrops, boulders, and high radioactivity soils. This research aim is to get know how of the extension, characters, and potential. The research approach was topographic, geologic, and radiometric soil mapping, trenching, and mineralogical and chemical analysis. The results are soil radiometric anomalies orientation are WNW-ESE strike or N-S, appropriate to the mineralization orientation. The mineralization have filled WNW-ESE fractures and associated with N-S fractures and it can be distinguished into five mineralization zones. The radioactive mineral consists of uraninite, gummite, autunite, and monazite, which are associated with magnetite, ilmenite, pyrite, quartz, feldspar, pyrrhotite, and chalcopyrite. Geochemically, the uranium content is well correlated with Co (R=0.601), Ni (R=0.646), Ag (R=0.752), Au (R=0.654), Pb (R=0.896) and Mo (R=0.847). The mineralization at Jumbang I sector could be classified as vein type granite related subtype, peri granitic class. Their potential until 50 m depth is 230.08 tons U within the speculative category of resources

Sulphatising roasting of a Greenlandic uranium ore, reactivity of minerals and recovery

International Nuclear Information System (INIS)

Gamborg Hansen, J.K.

1977-03-01

Uranium in the lujavrite ore from Kvanefjeld, South Greenland, can be solubilised by sulphatising roasting at 700degC. The reactivity of various lujavrite minerals in the roasting process and the mechanism of the reaction were investigated by X-ray diffraction, optical microscopy, electron microprobe, thermal analysis, Moessbauer and infrared spectroscopy. Soluble sulphates are formed on the surface of the grains; an outer zone of the grains is transformed; usually a core remains unchanged. Variations in uranium recovery can be explained by variations in the contents of the uranium-bearing minerals, steenstrupine and uranium-containing pigmentary material (altered Zr containing silicate minerals), and in the degree of alteration os steenstrupine. Characterization of these minerals required many qualitative and a few quantitative electron microprobe analyses. (author)

Methods of mineral potential assessment of uranium deposits: A mineral systems approach

International Nuclear Information System (INIS)

Jaireth, S.

2014-01-01

Mineral potential represents the likelihood (probability) that an economic mineral deposit could have formed in an area. Mineral potential assessment and prospectivity analysis use a probabilistic concepts to mineral deposits, where the probability of an event (formation of a mineral deposit) is conditional on two factors : i) geological processes occurring in the area, and ii) the presence of geological features indicative of those process. For instance, one of the geological processes critical for the formation of sandstone-hosted uranium deposits in an area is transport of uranium in groundwaters. Geological features indicative of this process in an area comprise, i) presence of leachable source rocks of uranium; ii) presence of highly permeable sandstone; and iii) suitable hydrogeological gradient driving flow groundwaters. Mineral deposits can also be conceptualised as mineral systems with more emphasis on mineralising processes. This concept has some clear parallels with the petroleum systems approach which has proven to be a useful in oil and gas exploration. Mineral systems are defined as ‘all geological factors that control the generation and preservation of mineral deposits’. Seven important geological factors are outlined to define the characteristics of a hydrothermal mineral system. These factors include: i) source of the mineralising fluids and transporting legends; ii) source of metals and other ore components; iii) migration pathways which may include inflow as well as outflow zones; iv) thermal gradients; v) source of energy to mobilised fluids; vi) mechanical and structural focusing mechanism at the trap site; and vii) chemical and/or physical cause for precipitation of ore minerals at the trap site. This approach, commonly known as the ‘source’, ‘transport’ and ‘trap’ paradigm has been redefined to introduce five questions as a basis to understand spatial and temporal evolution of a mineral system at all scales (regional to

Hydrothermal uranium deposits containing molybdenum and fluorite in the Marysvale volcanic field, west-central Utah

Science.gov (United States)

Cunningham, C.G.; Rasmussen, J.D.; Steven, T.A.; Rye, R.O.; Rowley, P.D.; Romberger, S.B.; Selverstone, J.

1998-01-01

Uranium deposits containing molybdenum and fluorite occur in the Central Mining Area, near Marysvale, Utah, and formed in an epithermal vein system that is part of a volcanic/hypabyssal complex. They represent a known, but uncommon, type of deposit; relative to other commonly described volcanic-related uranium deposits, they are young, well-exposed and well-documented. Hydrothermal uranium-bearing quartz and fluorite veins are exposed over a 300 m vertical range in the mines. Molybdenum, as jordisite (amorphous MoS2, together with fluorite and pyrite, increase with depth, and uranium decreases with depth. The veins cut 23-Ma quartz monzonite, 20-Ma granite, and 19-Ma rhyolite ash-flow tuff. The veins formed at 19-18 Ma in a 1 km2 area, above a cupola of a composite, recurrent, magma chamber at least 24 ?? 5 km across that fed a sequence of 21- to 14-Ma hypabyssal granitic stocks, rhyolite lava flows, ash-flow tuffs, and volcanic domes. Formation of the Central Mining Area began when the intrusion of a rhyolite stock, and related molybdenite-bearing, uranium-rich, glassy rhyolite dikes, lifted the fractured roof above the stock. A breccia pipe formed and relieved magmatic pressures, and as blocks of the fractured roof began to settle back in place, flat-lying, concave-downward, 'pull-apart' fractures were formed. Uranium-bearing, quartz and fluorite veins were deposited by a shallow hydrothermal system in the disarticulated carapace. The veins, which filled open spaces along the high-angle fault zones and flat-lying fractures, were deposited within 115 m of the ground surface above the concealed rhyolite stock. Hydrothermal fluids with temperatures near 200??C, ??18OH2O ~ -1.5, ?? -1.5, ??DH2O ~ -130, log fO2 about -47 to -50, and pH about 6 to 7, permeated the fractured rocks; these fluids were rich in fluorine, molybdenum, potassium, and hydrogen sulfide, and contained uranium as fluoride complexes. The hydrothermal fluids reacted with the wallrock resulting in

A new approach for the high-precision determination of the elemental uranium concentration in uranium ore by gamma-ray spectrometry

International Nuclear Information System (INIS)

Nagel, W.; Quik, F.

1993-01-01

A new approach for the determination of elemental uranium in uranium bearing ore, using high resolution gamma-ray spectrometry, was applied. Using a variant of the enrichment meter technique an agreement of better than 1% has been obtained between gamma-ray measurement results and the certified value obtained by other analytical methods. For the calibration of the gamma-ray spectrometer uranium reference samples have been used which are made available jointly in Europe and the USA as Certified Reference Materials for Gamma-ray Spectrometry (EC NRM 171 and NBS SRM 969, respectively). The measured ore has been put in a special designed container which ensured in all directions seen from the radiation window a uniform degree of infinite thickness of about 95%. The measurement results can be taken as an example for the applicability of gamma-ray spectrometry when high accuracy is required and under conditions where homogeneous distributed elemental uranium is embedded in a larger amount of matrix material. (author). 8 refs., 10 figs., 2 tabs., 2 appendices

Preliminary study of the uranium potential of the Triassic Sanford basin and Colon cross structure, North Carolina

International Nuclear Information System (INIS)

Lee, C.H.

1978-01-01

A preliminary geologic investigation was conducted to determine if Triassic sedimentary rocks of the Sanford basin and Colon cross structure in North Carolina are favorable hosts for uranium deposits. Rocks of adjacent Carolina slate belt were also examined as a potential source of uranium. On the basis of favorability criteria for sandstone-type uranium deposits, and geologic and geophysical investigations of the study area, the most favorable sites for further investigation are (1) at the contacts between the Pekin and Cumnock and between the Pekin and Sanford Formations near the Colon cross structure and (2) at the base of the Jonesboro fault, which lies below the Sanford Formation, northwest of Sanford. The highly weathered granites southeast of the Jonesboro fault were a source of the detritus deposited on the cross structure and may have been a primary source of uranium. Uranium leached from the coarse sediment (Pekin Formation) of the cross structure may have been transported downdip and may have been precipitated by the carbonaceous shales of the Cumnock Formation on the western side of the cross structure or at the Pekin-Sanford contact to the east. The Jonesboro fault may provide an impermeable barrier to ground-water migration in the metamorphosed basement rocks below the Triassic sediments. Such a barrier would constitute a favorable site for the precipitation and retention of uranium. Scintillometer surveys and laboratory analyses indicate no anomalous surface radioactivity in the study area. However, deep surface weathering may have caused the uranium to be leached from the exposed rocks and redeposited at depth. Geologic investigations show that conditions which have proven favorable for deposition of uranium in other areas are present in the Triassic rocks of the Sanford basin and Colon cross structure. However, because of deep surface weathering, further subsurface studies are necessary to confirm the favorability of the rocks as hosts for uranium

National uranium resource evaluation, preliminary report

International Nuclear Information System (INIS)

1976-06-01

The results of the initial phase of the National Uranium Resource Evaluation (NURE) are reported. NURE is a comprehensive nationwide program to evaluate uranium resources and to identify areas favorable for uranium exploration. Part I presents estimates of uranium ore reserves and potential resources available at costs (not prices) of $10, $15, and $30 per pound U 3 O 8 (uranium oxide). These estimates comprise the national uranium resource position. They are, however, preliminary because limitations of time and available geologic data prevented adequate assessment of some areas that may be favorable for potential resources. Part II presents the potential uranium resources for each of 13 regions, whose boundaries have been drawn chiefly on geologic considerations. The general geology is summarized, and the types of uranium deposits are described. Although limited geologic reconnaissance was done in various parts of the country, the report is based primarily on the compilation and evaluation of data in ERDA files. Mining companies furnished a substantial amount of information on exploration results, development, production, and future plans. Published, manuscript, and open-file reports by government agencies, universities, and research organizations were reviewed. In addition, many individuals affiliated with universities and with state and federal agencies provided supplemental geologic information. This was particularly helpful in the eastern and central states and in Alaska, where information on uranium occurrences is limited

Nuclear purity and the production of uranium (1962); La purete nucleaire et la fabrication de l'uranium (1962)

Energy Technology Data Exchange (ETDEWEB)

Verte, P [Commissariat a l' Energie Atomique, Centre du Bouchet, Saclay (France). Centre d' Etudes Nucleaires

1962-07-01

When the production of 'nuclear grade' uranium is dealt with, it is difficult, the author of this study points out, to separate its chemical, technical, and economical bearings. While recalling the evolution of chemical processes in various countries and describing the technic of uranium manufacture in the plant of the French 'Commissariat a l'Energie Atomique' at Le Bouchet, the author outlines the effect of economical contingencies on the problems the chemists and engineer are faced with. The question of cost price is also considered here with particular attention. (author) [French] Lorsqu'il s'agit de la production d'uranium de 'qualite nucleaire', il est difficile, souligne l'auteur de cette etude, de separer les aspects chimique, technique et economique. Aussi, en retracant l'evolution des procedes chimiques dans divers pays et decrivant les techniques de fabrication de l'uranium a l'usine du Bouchet du Commissariat a l'Energie Atomique, l'auteur ne manque-t-il pas de rappeler les incidences de la conjoncture economique sur les problemes posees au chimiste et a l'ingenieur. La question du prix de revient, egalement, est traitee ici avec une attention particuliere. (auteur)

Dictyonema black shale and Triassic sandstones as potential sources of uranium

Directory of Open Access Journals (Sweden)

Kiegiel Katarzyna

2015-09-01

Full Text Available The main objective of the present study was an assessment of the possibility of uranium recovery from domestic resources in Poland. In the first stage uranium was leached from the ground uranium ore by using acidic (sulfuric acid or hydrochloric acid or alkaline (carbonate solutions. The leaching efficiencies of uranium were dependent on the type of ore and it reached 81% for Dictyonemic shales and almost 100% for sandstones. The novel leaching routes, with the application of the helical membrane contactor equipped with rotating part were tested. The obtained postleaching solutions were concentrated and purified using solvent extraction or ion exchange chromatography. New methods of solvent extraction, as well as hybrid processes for separation and purification of the product, were studied. Extraction with the use of membrane capillary contactors that has many advantages above conventional methods was also proposed as an alternative purification method. The final product U3O8 could be obtained by the precipitation of ‘yellow cake’, followed by calcination step. The results of precipitation of ammonium diuranate and uranium peroxide from diluted uranium solution were presented

Reviews on the metallogenic and geological features of sandstone-type uranium deposits in Japan

International Nuclear Information System (INIS)

Pei Chengkai; Huang Xianfang; Zhang Baoju

2006-01-01

Regional geologic settings of sandstone-type uranium deposits in Japan are firstly analyzed. The regional tectonic evolution characteristics of 'Green tuff region' and 'Non green tuff region' and their relationship with uranium mineralization are elaborated in depth. Based on those mentioned above, the uranium sources of sandstone-type uranium deposits in Japan are discussed deeply and the most favorable uranium sources are considered to come from the basement and the surrounding granites. Their intrusive epochs range from Later Cretaceous to Palaeogene (about 60 to 70 Ma ago). The characteristics of ore-bearing host rocks, matter compositions of the deposits, ore formation enrichment factors, the hydrogeologic conditions and so on are described by taking Ningyo-Toge and Tono deposits as examples. Finally, the prospecting measures for the palaeo-channel sandstone-type uranium deposits (basal type) are reviewed. (authors)

Uranium enrichment

International Nuclear Information System (INIS)

Rae, H.K.; Melvin, J.G.

1988-06-01

Canada is the world's largest producer and exporter of uranium, most of which is enriched elsewhere for use as fuel in LWRs. The feasibility of a Canadian uranium-enrichment enterprise is therefore a perennial question. Recent developments in uranium-enrichment technology, and their likely impacts on separative work supply and demand, suggest an opportunity window for Canadian entry into this international market. The Canadian opportunity results from three particular impacts of the new technologies: 1) the bulk of the world's uranium-enrichment capacity is in gaseous diffusion plants which, because of their large requirements for electricity (more than 2000 kW·h per SWU), are vulnerable to competition from the new processes; 2) the decline in enrichment costs increases the economic incentive for the use of slightly-enriched uranium (SEU) fuel in CANDU reactors, thus creating a potential Canadian market; and 3) the new processes allow economic operation on a much smaller scale, which drastically reduces the investment required for market entry and is comparable with the potential Canadian SEU requirement. The opportunity is not open-ended. By the end of the century the enrichment supply industry will have adapted to the new processes and long-term customer/supplier relationships will have been established. In order to seize the opportunity, Canada must become a credible supplier during this century

Automated electron microprobe identification of minerals in stream sediments for the national uranium resources evaluation program

International Nuclear Information System (INIS)

Mosley, W.C. Jr.

1979-01-01

Over 500 stream sediment particles have been analyzed. About 96% have been identified as distinct minerals. Most of the others appeared to be mixtures. Only zinc-bearing gahnite had to be analyzed further for positive identification. Monazite and zircon were the only minerals with concentrations of uranium significantly above the detection limit. The Frantz Isodynamic Magnetic Separator isolated the monazite into the 1.0 fraction. Monazite particles in anomalous sediments contained up to 3.7 wt % uranium. This uranium concentration is unusually high for monazite, which normally has about 0.5 wt % uranium, and may be the cause of the anomaly

Zeta potential of Polish copper-bearing shale in the absence and presence of flotation frothers

Directory of Open Access Journals (Sweden)

Mengsu Peng

2014-09-01

Full Text Available In this paper, zeta potential as a function of pH of copper-bearing shale, which is mined in Poland by KGHM, was investigated. The measurements were conducted in water and aqueous solutions of selected flotation frothers. It was established that for investigated copper-bearing shale, after dispersion in water, the isoelectric point (IEP occurs at pH=3.5. Addition of frothers decreased the IEP on the pH scale and the IEP for butanol was 1.93, for MIBC 2.90 and for eicosaethylene glycol hexadecyl ether (C16E20 2.76. In the case of introducing frothers changed, the zeta potential becomes less negative. An empirical equation, having two adjustable parameters, was used in the paper to approximate the course of the zeta potential-pH curve. The equation showed a very good approximation of the zeta potential of the investigated shale either in water or frother aqueous solutions.

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

Science.gov (United States)

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

Potential for radionuclide immobilization in the EBS/NFE: solubility limiting phases for neptunium, plutonium, and uranium

Energy Technology Data Exchange (ETDEWEB)

Rard, J. A., LLNL

1997-10-01

Retardation and dispersion in the far field of radionuclides released from the engineered barrier system/near field environment (EBS/NFE) may not be sufficient to prevent regulatory limits being exceeded at the accessible environment. Hence, a greater emphasis must be placed on retardation and/or immobilization of radionuclides in the EBS/NFE. The present document represents a survey of radionuclide-bearing solid phases that could potentially form in the EBS/NFE and immobilize radionuclides released from the waste package and significantly reduce the source term. A detailed literature search was undertaken for experimental solubilities of the oxides, hydroxides, and various salts of neptunium, plutonium, and uranium in aqueous solutions as functions of pH, temperature, and the concentrations of added electrolytes. Numerous solubility studies and reviews were identified and copies of most of the articles were acquired. However, this project was only two months in duration, and copies of some the identified solubility studies could not be obtained at short notice. The results of this survey are intended to be used to assess whether a more detailed study of identified low- solubility phase(s) is warranted, and not as a data base suitable for predicting radionuclide solubility. The results of this survey may also prove useful in a preliminary evaluation of the efficacy of incorporating chemical additives to the EBS/NFE that will enhance radionuclide immobilization.

Development of the Ranger uranium milling operations

International Nuclear Information System (INIS)

Baily, P.A.

1982-01-01

The development and operation of the Ranger uranium project is described. In 1969 Ranger discovered a uranium-bearing ore deposit in the Alligator Rivers Region of the Northern Territory of Australia. Extensive testwork on drill core samples proved the viability of the extraction of the uranium and a process flowsheet and plant design criteria were developed based on a conventional crushing, grinding, acid leach, C.C.D., solvent extraction circuit. Detailed design concentrated on plant layout, materials of construction, equipment vendor selection and process control. These factors required special attention because of the remote location of the mine and the high cost and difficulty in obtaining trained labour for such sites. Environmental considerations were key factors in design. The mine is located adjacent to a national park and has an average rainfall of 1,600 mm. No water or liquid effluents are to be released from the project area and thus water management is a key factor. Tailings are ponded in an impervious earth-rockfill dam

Uranium in blood

International Nuclear Information System (INIS)

Koul, S.L.; Chadderton, L.T.

1979-01-01

When fission fragments pass through certain solids they leave trails of radiation damage which can be observed by transmission electron microscopy. If the solid can be chemically etched these tracks are 'developed' and brought within the resolving power of the light optical microscope. Since its introduction the etching technique has been used to reveal tracks formed due to the thermal neutron induced fission of U 235 atoms in many uranium bearing materials of both terrestrial and extraterrestrial origin. Successful experiments have been performed in determining the distribution of uranium in selected botanical species. On the basis of this most recent work it was decided to make a feasibility study of a determination of the concentration in human blood. This short report produces evidence not only that the fission track etching technique is useful for this purpose but that there are significant uranium concentration differences in blood taken from leukemia patients compared with samples taken from healthy norms. Whilst experiments of this kind generally employ direct registration of the fission fragments in the material itself, as with minerals, an alternative procedure is to employ some overlay, such as thin sheets of muscovite mica, or of a suitable plastic. In the present investigations the plastic Lexan polycarbonate (C 6 H 15 O 3 ) was selected as an overlay since it is easy to etch chemically. (author)

Radioactivity and uranium potentialities of wadi hammad area, north eastern desert, Egypt. Vol. 3

Energy Technology Data Exchange (ETDEWEB)

Salman, A B; Shalaby, M H; Khamis, H A [Nuclear Material Authority, Cairo, (Egypt)

1996-03-01

Late proterozoic, pan-african rocks exposed at Wadi Hammad area are represented by metamorphosed and un metamorphosed sediments and volcanics in addition to different types of intensive rocks. Systematic radiometric survey is conducted at W.Hammad area in order to reveal the distribution of radioactivity and uranium potentialities. Statistical analysis of the field data collected indicate that, high level of {delta}-radioactivity is linked to the younger granites compared with the other rock types. The tree types of younger granites recorded in the area namely: porphyritic granites, biotite granites, and perthitic leucogranites differ among each other in their ground radioactivity. The increase in ground {delta}- radioactivity from the porphyritic to biotite granites to perthitic leucogranites corresponds to the increase in the uranium content of these granites. Four radioactive anomalies were discovered in the younger granites of the area of W.Hammad. The genetic relation between certain set of fractures and the distribution of {delta}- radioactivity in G. El Gulf granites indicates that the area of anomalous radioactivity are structurally controlled by joint sets trending N-S, NNE-SSW and NNW-SSE. The presence of intensive hematitization episyenitization, red and milky silica veins, aplites and pegmatite veins indicate the presence of hydrothermal activities along these fractures. It is worth to mention that, the presence of episyentizied zone associated with radioactive anomaly, represents a good indication for the possibility of hosting uranium deposits in deeper horizon. Moreover, the presence of high back-ground of magnetic uranium in the perthitic leucogranites increases studied the possibility of concentration of uranium by leaching from the granites. 12 figs., 1 tab.

Radioactivity and uranium potentialities of wadi hammad area, north eastern desert, Egypt. Vol. 3

International Nuclear Information System (INIS)

Salman, A.B.; Shalaby, M.H.; Khamis, H.A.

1996-01-01

Late proterozoic, pan-african rocks exposed at Wadi Hammad area are represented by metamorphosed and un metamorphosed sediments and volcanics in addition to different types of intensive rocks. Systematic radiometric survey is conducted at W.Hammad area in order to reveal the distribution of radioactivity and uranium potentialities. Statistical analysis of the field data collected indicate that, high level of δ-radioactivity is linked to the younger granites compared with the other rock types. The tree types of younger granites recorded in the area namely: porphyritic granites, biotite granites, and perthitic leucogranites differ among each other in their ground radioactivity. The increase in ground δ- radioactivity from the porphyritic to biotite granites to perthitic leucogranites corresponds to the increase in the uranium content of these granites. Four radioactive anomalies were discovered in the younger granites of the area of W.Hammad. The genetic relation between certain set of fractures and the distribution of δ- radioactivity in G. El Gulf granites indicates that the area of anomalous radioactivity are structurally controlled by joint sets trending N-S, NNE-SSW and NNW-SSE. The presence of intensive hematitization episyenitization, red and milky silica veins, aplites and pegmatite veins indicate the presence of hydrothermal activities along these fractures. It is worth to mention that, the presence of episyentizied zone associated with radioactive anomaly, represents a good indication for the possibility of hosting uranium deposits in deeper horizon. Moreover, the presence of high back-ground of magnetic uranium in the perthitic leucogranites increases studied the possibility of concentration of uranium by leaching from the granites. 12 figs., 1 tab

Kinetic study of the thermal decomposition of uranium metaphosphate, U(PO{sub 3}){sub 4}, into uranium pyrophosphate, UP{sub 2}O{sub 7}

Energy Technology Data Exchange (ETDEWEB)

Yang, Hee-Chul, E-mail: nhcyang@kaeri.re.kr; Kim, Hyung-Ju; Lee, Si-Young; Yang, In-Hwan; Chung, Dong-Yong

2017-06-15

The thermochemical properties of uranium compounds have attracted much interest in relation to thermochemical treatments and the safe disposal of radioactive waste bearing uranium compounds. The characteristics of the thermal decomposition of uranium metaphosphate, U(PO{sub 3}){sub 4}, into uranium pyrophosphate, UP{sub 2}O{sub 7}, have been studied from the view point of reaction kinetics and acting mechanisms. A mixture of U(PO{sub 3}){sub 4} and UP{sub 2}O{sub 7} was prepared from the pyrolysis residue of uranium-bearing spent TBP. A kinetic analysis of the reaction of U(PO{sub 3}){sub 4} into UP{sub 2}O{sub 7} was conducted using an isoconversional method and a master plot method on the basis of data from a non-isothermal thermogravimetric analysis. The thermal decomposition of U(PO{sub 3}){sub 4} into UP{sub 2}O{sub 7} followed a single-step reaction with an activation energy of 175.29 ± 1.58 kJ mol{sup −1}. The most probable kinetic model was determined as a type of nucleation and nuclei-growth models, the Avrami-Erofeev model (A3), which describes that there are certain restrictions on nuclei growth of UP{sub 2}O{sub 7} during the solid-state decomposition of U(PO{sub 3}){sub 4}. - Highlights: •Thermal decomposition kinetics of U(PO{sub 3}){sub 4} into UP{sub 2}O{sub 7} was investigated. •The thermal decomposition followed a single-step reaction with an activation energy of 175.3 ± 1.6 kJ mol{sup −1}. •The most probable kinetic model was determined as a type of nucleation and nuclei-growth models, the Avrami-Erofeev (A3).

Uranium Speciation in Drinking Water from Drilled Wells in Southern Finland and Its Potential Links to Health Effects

International Nuclear Information System (INIS)

Prat, O.; Vercouter, Th.; Ansoborlo, E.; Fichet, P.; Perret, P.; Kurttio, P.; Salonen, L.

2009-01-01

Exceptionally high concentrations of natural uranium have been found in drinking water originating from drilled wells in Southern Finland. However, no clear clinical symptoms have been observed among the exposed population. Hence a question arose as to whether uranium speciation could be one reason for the lack of significant adverse health effects. Uranium species were determined using time-resolved laser-induced-fluorescence-spectroscopy. We performed multi-element chemical analyses in these water samples, and predictive calculations were carried out using up-to-date thermodynamic data. The results indicated good agreement between measurements and modeling. The low toxicity of Finnish bedrock water may be due to the predominance of two calcium dependent species, Ca 2 UO 2 (CO 3 ) 3 (aq) and CaUO 2 (CO 3 ) 3 2- , whose non toxicity for cells has been described previously. This interdisciplinary study describes chemical speciation of drinking water with elevated uranium concentrations and the potential consequence on health. From these results, it appears that modeling could be used for a better understanding of uranium toxicity of drinking water in the event of contamination. (authors)

Bear Creek Project. Draft environmental statement

International Nuclear Information System (INIS)

1977-01-01

The Bear Creek Project consists of mining and milling operations involving uranium ore deposits located in Converse County, Wyoming. Mining of uranium from six known ore bodies will take place over ten years; a 1000 tons ore/day will be constructed and operated as long as ore is available. The tailings will be stored onsite in an impoundment. The project would convert 2700 acres from grazing use to mining/milling activities for about ten years. Mining would disturb a total of 1600 acres but, because of reclamation, the max acreage disturbed at any one time would be about 1000 acres, the average being about 650 acres. Dose rates were computed for an individual in a ranch house at the nearest ranch. Conditions for the protection of the environment are proposed. Possible environmental impacts evaluated cover air, land, water, soil, vegetation, wildlife, and community. A benefit-cost analysis is made

Enhanced fuel production in thorium/lithium hybrid blankets utilizing uranium multipliers

Energy Technology Data Exchange (ETDEWEB)

Pitulski, R.H.

1979-10-01

A consistent neutronics analysis is performed to determine the effectiveness of uranium bearing neutron multiplier zones on increasing the production of U/sup 233/ in thorium/lithium blankets for use in a tokamak fusion-fission hybrid reactor. The nuclear performance of these blankets is evaluated as a function of zone thicknesses and exposure by using the coupled transport burnup code ANISN-CINDER-HIC. Various parameters such as U/sup 233/, Pu/sup 239/, and H/sup 3/ production rates, the blanket energy multiplication, isotopic composition of the fuels, and neutron leakages into the various zones are evaluated during a 5 year (6 MW.y.m/sup -2/) exposure period. Although the results of this study were obtained for a tokomak magnetic fusion device, the qualitative behavior associated with the use of the uranium bearing neutron multiplier should be applicable to all fusion-fission hybrids.

A dark side of the fuel cycle: some military uses of depleted uranium and potential consequences

International Nuclear Information System (INIS)

Andrews, W.S.; Lewis, B.J.; Bennett, L.G.I.; Ough, E.A.

2001-01-01

Over the past quarter century, depleted uranium (DU) has replaced tungsten alloys as the material of choice for penetrators in armour piercing rounds, in some armies, as well as a supplement to steel in tank armour. The tendency for adiabatic shear failure to overcome work hardening, and increased ductility are attributed for the improved ballistic performance. The aerosolization of a portion of the penetrator on impact creates a potential health hazard, particularly through ingesting resuspended aerosol particles. Bioassays of US and Canadian servicemen, potentially exposed to DU contamination, have failed to establish a link between DU and symptoms of 'Gulf War illness'. Further, Canadian testing has not been able to identify elevated levels of DU or even natural uranium in urine, hair or bone samples of veterans. (author)

Jabiluka uranium project

International Nuclear Information System (INIS)

Anon.

1991-01-01

The Jabiluka uranium and gold deposit located in the Northern Territory of Australia is the world's largest known primary uranium deposits and as such has the potential to become one of the most important uranium projects in the world. Despite the financial and structural challenges facing the major owner Pancontinental Mining Limited and the changing political policies in Australia, Jabiluka is well situated for development during the 1990's. With the availability of numerous financial and development alternatives, Jabiluka could, by the turn of the century, take its rightful place among the first rank of world uranium producers. The paper discusses ownership, location, property rights, licensing, environmental concerns, marketing and development, capital costs, royalties, uranium policy considerations, geologic exploration history, regional and site geology, and mining and milling operations

Determination of rare earth elements in uranium bearing samples using Inductively Coupled Plasma Mass Spectrometry (ICPMS)

International Nuclear Information System (INIS)

Mishra, S.; Chaudhury, P.; Pradeepkumar, K.S.; Sahoo, S.K.

2017-01-01

In the present study a methodology has been described for determination of REEs without involving separation and the method is successfully applied for determination of REE concentration in uranium ore as well as in soil samples from a uranium mining site

Surficial origin of North American pitchblende and related uranium deposits

International Nuclear Information System (INIS)

Langford, F.F.

1977-01-01

The ubiquitous association of pitchblende uranium deposits with terrestrial sediments is believed to be the natural result of formation of the orebodies by surficial processes operating under continental conditions. The major uranium deposits of North America illustrate this. The quartz-pebble conglomerate uranium deposits of Elliot Lake, Ontario, have thorium-rich uranium minerals that indicate a detrital origin. With the development of an oxygenic atmosphere before 1,700 m.y. ago, uranium was transported in solution in meteoric surface and near-surface ground water, and produced pitchblende veins in fractures in the basement and in lava flows in terrestrial environments. This accounts for the closee association of fluvial sediments with the pitchblende deposits at Beaverlodge, Rabbit Lake, Baker Lake, and Great Bear Lake, Canada. The development of land plants about 300 m.y. ago produced favorable environments within the terrestrial sandstones themselves, and resulted in the tabular uranium orebodies of the Colorado Plateau. The close relation of tabular orebodies to sedimentation is apparent when compared to recent fluvial sedimentation. In Wyoming, the stratigraphic restriction of the boundary-roll deposits to a few zones in Eocene rocks results from their being remobilized tabular deposits

Genesis of uranium deposits of the Tono Mine, Japan

International Nuclear Information System (INIS)

Katayama, N.; Kubo, K.; Hirono, S.

1974-01-01

The uranium deposits of the Tono mine, Gifu Prefecture, Japan, occur in the basal part of the Toki group of Miocene age, and are distributed in the tributaries or at the head of channels on the plane of unconformity under the formation. These features characterize the basal ground-water type of uranium deposit, and they are unique in that their typical ore mineral is a zeolite of the heulandite-clinoptilolite group, uranium being adsorbed in it. The paper presents the history of formation of the Tsukiyoshi deposits, the most intensely explored in the Tono mine. The matrices of conglomerates and sandstones of the Toki group usually contain tuffaceous material, which has been montmorillonitized or zeolitized diagenetically. The conduit of uranium-bearing ground waters that migrated from the basement granites into the Tertiary sediments was controlled by the impermeable barriers, which are rocks in which montmorillonite predominated, or by the Tsukiyoshi fault, as well as by channel structures. Where the waters became rather stagnant, uranium was adsorbed in zeolite from them. Enrichment of uranium further proceeded locally as follows. Pyrite was oxidized to produce sulphuric acid solution which leached the uranium that had been adsorbed in zeolite. The pH of the uranium-rich solution became higher and higher in the course of migration and, as soon as it reached about 4, the uranium in the solution was again adsorbed in zeolite, the uranium content of which may have been enriched up to 0.9%. Coffinites have been formed where uranium was accumulated over the adsorption capacity of zeolite or where strongly reducing conditions were maintained by carbonaceous matter. (author)

Synthesis of Uranium nitride powders using metal uranium powders

International Nuclear Information System (INIS)

Yang, Jae Ho; Kim, Dong Joo; Oh, Jang Soo; Rhee, Young Woo; Kim, Jong Hun; Kim, Keon Sik

2012-01-01

Uranium nitride (UN) is a potential fuel material for advanced nuclear reactors because of their high fuel density, high thermal conductivity, high melting temperature, and considerable breeding capability in LWRs. Uranium nitride powders can be fabricated by a carbothermic reduction of the oxide powders, or the nitriding of metal uranium. The carbothermic reduction has an advantage in the production of fine powders. However it has many drawbacks such as an inevitable engagement of impurities, process burden, and difficulties in reusing of expensive N 15 gas. Manufacturing concerns issued in the carbothermic reduction process can be solved by changing the starting materials from oxide powder to metals. However, in nitriding process of metal, it is difficult to obtain fine nitride powders because metal uranium is usually fabricated in the form of bulk ingots. In this study, a simple reaction method was tested to fabricate uranium nitride powders directly from uranium metal powders. We fabricated uranium metal spherical powder and flake using a centrifugal atomization method. The nitride powders were obtained by thermal treating those metal particles under nitrogen containing gas. We investigated the phase and morphology evolutions of powders during the nitriding process. A phase analysis of nitride powders was also a part of the present work

Spectral discrimination of uranium-mineralized breccia pipes in northwestern Arizona

International Nuclear Information System (INIS)

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

1989-01-01

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

Some characteristics of uranium distribution in granular phosphorites of Arabian-African phosphorite-bearing Province and the Middle Asia

Energy Technology Data Exchange (ETDEWEB)

Pokryshkin, V I; Bol' shov, V A; Kharitonova, R Sh; Bojko, V S; Berman, I B

1982-01-01

The comprative characteristic of uranium distribution regula-Arities in phosphorites of Arabian-African province and the Middle Asia is given. The data on radioactivity of phosphorites of Arabian-African province are borrowed for the published papers, the laboratory U and Th determinations are partially performed. Radioactivity of the Middle Asia phosphorites is studied by field radiometric and gamma spectrometric methods. Spatial uranium distribution in granular phosphorites has been determined by the f-radiography method. At the presence of general for granular phosphorites of both regions of increased radioactivity, uranium confinement to phosphate matter and identicity of uranium distribution in them, higher uranium content of Arabian-African province is pointed out. By K and Th quatities being due to a radioactivity unit, Arabian-African phosphorites are similar to authigenous phosphorites of the Middle Asia, by uranium content Arabian phosphorites are richer than the Asian ones. Allothigenous phosphorites differ from authigenous and African ones, relative (per radioactivity unit) uranium contents in them are 2.2-1.3 times less, while thorium and potassium 5.2-6.8 times higher. This fact reflects their poverty in phosphate matter and enrichment by terrigenous sandy-argillaceous material.

Politics of Uranium

International Nuclear Information System (INIS)

Anon.

1982-01-01

Uranium is the most political of all the elements, the material for the production of both the large amounts of electricity and the most destructive weapons in the world. The problems that its dual potential creates are only now beginning to become evident. Author Norman Moss looks at this situation and sheds light on many of the questions that emerge. The nuclear issue always comes back to how much uranium there is, what can be done with it, and which countries have it. Starting with a concise history of uranium and explaining its technology in terms the nonspecialist can understand, The Politics of Uranium considers the political issues that technical arguments obscure. It tells the little-known story of the international uranium cartel, explains the entanglements of governments with the uranium trade, and describes the consequences of wrong decisions and blunders-especially the problems of nuclear waste. It also examines the intellectual and emotional roots of the anti-nuclear movement

Oxidation state analyses of uranium with emphasis on chemical speciation in geological media

International Nuclear Information System (INIS)

Ervanne, H.

2004-01-01

This thesis focuses on chemical methods suitable for the determination of uranium redox species in geological materials. Nd-coprecipitation method was studied for the determination of uranium oxidation states in ground waters. This method is ideally suited for the separation of uranium oxidation states in the field, which means that problems associated with the instability of U(IV) during transport are avoided. An alternative method, such as ion exchange, is recommended for the analysis of high saline and calcium- and iron-rich ground waters. U(IV)/Utot was 2.8-7.2% in ground waters in oxidizing conditions and 60-93% in anoxic conditions. From thermodynamic model calculations applied to results from anoxic ground waters it was concluded that uranium can act as redox buffer in granitic ground waters. An ion exchange method was developed for the analysis of uranium oxidation states in different solid materials of geological origin. These included uranium minerals, uraniumbearing minerals, fracture coatings and bulk rock. U(IV)/Utot was 50-70% in uraninites, 5.8-8.7% in secondary uranium minerals, 15-49% in different fracture coatings and 64- 77% in samples from deep bedrock. In the uranium-bearing minerals, U(IV)/Utot was 33-43% (allanites), 5.9% (fergusonite) and 93% (monazite). Although the ion exchange method gave reliable results, there is a risk for the conversion of uranium oxidation states during analysis of heterogeneous samples due to the redox reactions that take place in the presence of some iron compounds. This risk was investigated in a study of several common iron-bearing minerals. The risk for conversion of uranium oxidation states can be screened by sample selection and minimized with use of a redox buffer compound such as polyacrylic acid (PAA). In studies of several carboxylic acids, PAA was found to be the most suitable for extending the application of the method. The stability of uranium oxidation states during analysis and the selectivity

Formation of albitite-hosted uranium within IOCG systems: the Southern Breccia, Great Bear magmatic zone, Northwest Territories, Canada

Science.gov (United States)

Montreuil, Jean-François; Corriveau, Louise; Potter, Eric G.

2015-03-01

Uranium and polymetallic U mineralization hosted within brecciated albitites occurs one kilometer south of the magnetite-rich Au-Co-Bi-Cu NICO deposit in the southern Great Bear magmatic zone (GBMZ), Canada. Concentrations up to 1 wt% U are distributed throughout a 3 by 0.5 km albitization corridor defined as the Southern Breccia zone. Two distinct U mineralization events are observed. Primary uraninite precipitated with or without pyrite-chalcopyrite ± molybdenite within magnetite-ilmenite-biotite-K-feldspar-altered breccias during high-temperature potassic-iron alteration. Subsequently, pitchblende precipitated in earthy hematite-specular hematite-chlorite veins associated with a low-temperature iron-magnesium alteration. The uraninite-bearing mineralization postdates sodic (albite) and more localized high-temperature potassic-iron (biotite-magnetite ± K-feldspar) alteration yet predates potassic (K-feldspar), boron (tourmaline) and potassic-iron-magnesium (hematite ± K-feldspar ± chlorite) alteration. The Southern Breccia zone shares attributes of the Valhalla (Australia) and Lagoa Real (Brazil) albitite-hosted U deposits but contains greater iron oxide contents and lower contents of riebeckite and carbonates. Potassium, Ni, and Th are also enriched whereas Zr and Sr are depleted with respect to the aforementioned albitite-hosted U deposits. Field relationships, geochemical signatures and available U-Pb dates on pre-, syn- and post-mineralization intrusions place the development of the Southern Breccia and the NICO deposit as part of a single iron oxide alkali-altered (IOAA) system. In addition, this case example illustrates that albitite-hosted U deposits can form in albitization zones that predate base and precious metal ore zones in a single IOAA system and become traps for U and multiple metals once the tectonic regime favors fluid mixing and oxidation-reduction reactions.

Monitoring and mitigating measures to reduce potential impacts of oil and gas exploration and development on bears in the Inuvik region

Energy Technology Data Exchange (ETDEWEB)

Branigan, M. [Government of the Northwest Territories, Inuvik, NT (Canada). Dept. of Environment and Natural Resources

2007-07-01

The Inuvik Region consists of the Northwest Territories portion of the Inuvialuit Settlement Region and the Gwich'in Settlement Area. The range of grizzly bears, polar bears and black bears extends to different parts of the region. The potential impact of development depends on the season of the development and the species of bear found in the footprint. As such, monitoring and mitigation measures should take this into consideration. This presentation focused on the potential impacts and current practices to monitor and mitigate the impacts in the region. Mitigation measures currently used include: communication with stakeholders; waste management guidelines; use of wildlife monitors to identify key habitat and den sites and to deter bears; minimum flight altitudes; and safety training. Suggestions for additional mitigation measures were also presented. figs.

Metals other than uranium affected microbial community composition in a historical uranium-mining site.

Science.gov (United States)

Sitte, Jana; Löffler, Sylvia; Burkhardt, Eva-Maria; Goldfarb, Katherine C; Büchel, Georg; Hazen, Terry C; Küsel, Kirsten

2015-12-01

To understand the links between the long-term impact of uranium and other metals on microbial community composition, ground- and surface water-influenced soils varying greatly in uranium and metal concentrations were investigated at the former uranium-mining district in Ronneburg, Germany. A soil-based 16S PhyloChip approach revealed 2358 bacterial and 35 archaeal operational taxonomic units (OTU) within diverse phylogenetic groups with higher OTU numbers than at other uranium-contaminated sites, e.g., at Oak Ridge. Iron- and sulfate-reducing bacteria (FeRB and SRB), which have the potential to attenuate uranium and other metals by the enzymatic and/or abiotic reduction of metal ions, were found at all sites. Although soil concentrations of solid-phase uranium were high, ranging from 5 to 1569 μg·g (dry weight) soil(-1), redundancy analysis (RDA) and forward selection indicated that neither total nor bio-available uranium concentrations contributed significantly to the observed OTU distribution. Instead, microbial community composition appeared to be influenced more by redox potential. Bacterial communities were also influenced by bio-available manganese and total cobalt and cadmium concentrations. Bio-available cadmium impacted FeRB distribution while bio-available manganese and copper as well as solid-phase zinc concentrations in the soil affected SRB composition. Archaeal communities were influenced by the bio-available lead as well as total zinc and cobalt concentrations. These results suggest that (i) microbial richness was not impacted by heavy metals and radionuclides and that (ii) redox potential and secondary metal contaminants had the strongest effect on microbial community composition, as opposed to uranium, the primary source of contamination.

Incorporation of uranium in pyrochlore oxides and pressure-induced phase transitions

Energy Technology Data Exchange (ETDEWEB)

Zhang, F.X., E-mail: zhangfx@umich.edu [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Lang, M.; Tracy, C.; Ewing, R.C. [Department of Earth and Environmental Sciences, University of Michigan, Ann Arbor, MI 48109 (United States); Gregg, D.J.; Lumpkin, G.R. [Institute of Materials Engineering, ANSTO, Locked Bag 2001, Kirrawee DC 2232, NSW (Australia)

2014-11-15

Uranium-doped gadolinium zirconates with pyrochlore structure were studied at ambient and high-pressure conditions up to 40 GPa. The bonding environment of uranium in the structure was determined by x-ray photoelectron and Raman spectroscopies and x-ray diffraction. The uranium valence for samples prepared in air is mainly U{sup 6+}, but U{sup 4+} is present in pyrochlores fabricated in an argon atmosphere. Rietveld refinement of the XRD pattern suggests that uranium ions in pyrochlores are on the 16d site in 6-fold coordination with oxygen. At pressures greater than 22 GPa, the pyrochlore structure transformed to a cotunnite-type phase. The cotunnite high-pressure phase transformed to a defect fluorite structure on the release of pressure. - Graphical abstract: In U-bearing pyrochlore, U ions mainly occupy the 16d site and replace the smaller Zr{sup 4+}, part of the oxygen will occupy the 8b site, which is empty to most pyrochlores. At pressure of 22 GPa, the pyrochlore lattice is not stable and transforms to a cotunnite-type structure. The high-pressure structure is not stable and transform to a fluorite or back to the pyrochlore structure when pressure is released. - Highlights: • We found that U ions mainly occupy the smaller cation site in U-bearing pyrochlore. • Pyrochlore structure is not stable at pressure of more than 20 GPa. • The quenched sample has a pyrochlore or a disordered fluorite structure.

Dissolved radon and uranium in groundwater in a potential coal seam gas development region (Richmond River Catchment, Australia).

Science.gov (United States)

Atkins, Marnie L; Santos, Isaac R; Perkins, Anita; Maher, Damien T

2016-04-01

The extraction of unconventional gas resources such as shale and coal seam gas (CSG) is rapidly expanding globally and often prevents the opportunity for comprehensive baseline groundwater investigations prior to drilling. Unconventional gas extraction often targets geological layers with high naturally occurring radioactive materials (NORM) and extraction practices may possibly mobilise radionuclides into regional and local drinking water resources. Here, we establish baseline groundwater radon and uranium levels in shallow aquifers overlying a potential CSG target formation in the Richmond River Catchment, Australia. A total of 91 groundwater samples from six different geological units showed highly variable radon activities (0.14-20.33 Bq/L) and uranium levels (0.001-2.77 μg/L) which were well below the Australian Drinking Water Guideline values (radon; 100 Bq/L and uranium; 17 μg/L). Therefore, from a radon and uranium perspective, the regional groundwater does not pose health risks to consumers. Uranium could not explain the distribution of radon in groundwater. Relatively high radon activities (7.88 ± 0.83 Bq/L) in the fractured Lismore Basalt aquifer coincided with very low uranium concentrations (0.04 ± 0.02 μg/L). In the Quaternary Sediments aquifers, a positive correlation between U and HCO3(-) (r(2) = 0.49, p uranium was present as uranyl-carbonate complexes. Since NORM are often enriched in target geological formations containing unconventional gas, establishing radon and uranium concentrations in overlying aquifers comprises an important component of baseline groundwater investigations. Copyright © 2016 Elsevier Ltd. All rights reserved.

Potential criticality accident at the General Electric Nuclear Fuel and Component Manufacturing Facility, May 29, 1991

International Nuclear Information System (INIS)

1991-08-01

At the General Electric Nuclear Fuel and Component Manufacturing facility, located near Wilmington, North Carolina, on May 28 and 29, 1991, approximately 150 kilograms of uranium were inadvertently transferred from safe process tanks to an unsafe tank located at the waste treatment facility, thus creating the potential for a localized criticality safety problem. The excess uranium was ultimately safely recovered when the tank contents were centrifuged to remove the uranium-bearing material. Subsequently, the US Nuclear Regulatory Commission dispatched an Incident Investigation Team to determine what happened, to identify probable causes, and to make appropriate findings and conclusions. This report describes the incident, the methodology used by the team in its investigation, and presents the team's findings and conclusions. 48 figs., 8 tabs

Uranium in alkaline rocks

Energy Technology Data Exchange (ETDEWEB)

Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

1978-04-01

Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential.

Uranium in alkaline rocks

International Nuclear Information System (INIS)

Murphy, M.; Wollenberg, H.; Strisower, B.; Bowman, H.; Flexser, S.; Carmichael, I.

1978-04-01

Geologic and geochemical criteria were developed for the occurrence of economic uranium deposits in alkaline igneous rocks. A literature search, a limited chemical analytical program, and visits to three prominent alkaline-rock localities (Ilimaussaq, Greenland; Pocos de Caldas, Brazil; and Powderhorn, Colorado) were made to establish criteria to determine if a site had some uranium resource potential. From the literature, four alkaline-intrusive occurrences of differing character were identified as type-localities for uranium mineralization, and the important aspects of these localities were described. These characteristics were used to categorize and evaluate U.S. occurrences. The literature search disclosed 69 U.S. sites, encompassing nepheline syenite, alkaline granite, and carbonatite. It was possible to compare two-thirds of these sites to the type localities. A ranking system identified ten of the sites as most likely to have uranium resource potential

A spectroscopic and microscopic study of uranium speciation in the infiltration pond sediments at Hanford, USA

International Nuclear Information System (INIS)

Wang, Z.; Zachara, J.M.; McKinley, J.P.; Smith, S.C.; Qafoku, O.; Catalano, J.G.

2005-01-01

Full text of publication follows: The infiltration ponds in the '300 area' of the U.S. Department of Energy Hanford Site received large volumes of nuclear waste that contained tens of metric tons of uranium along with high concentrations of other metals such as Cu, Fe, Mn, Al and Ca during their operations from 1943 to 1975. Leaching and migration of uranium in the pond sediments threatens the integrity of the Columbia River that is with 100 m of these ponds. A clear understanding of the speciation of uranium in the pond sediments is key to predict the dissolution and migration behavior of uranium and to develop any necessary containment or decontamination strategies. In this work, we studied the speciation of uranium in a series of Hanford infiltration pond sediments and its changes after dissolution in various solution media including DDI water, sodium bicarbonate (pH 9.5) and 1 M sodium acetate (pH 4.8), using liquid-helium temperature time-resolved laser-induced fluorescence spectroscopy (TRLFS) and time-resolved laser-induced fluorescence imaging spectro-microscopy (TRLFISM), and X-ray absorption spectroscopy (XAS). XAS analysis indicated that uranium in the sediment primarily existed in the 6+ oxidation state. The TRLFS spectra of uranium in several sediments resembled those in natural, uranyl-bearing calcite and those reported for uranium co-precipitated synthetic calcite and aragonite, suggesting the presence of similar uranyl coordination environments. The TRLFS spectra varied with both sediment location and depth and there was not a linear correlation between the spectral intensity and the overall concentration of uranium, indicating the presence of multiple uranium species. While for some sediment the major spectral characteristics appeared to remain the same after extraction using DDI water, sodium bicarbonate and even sodium acetate, for others, spectral changes were observed. Comparison of the sediment uranium TRLFS spectra with a standard spectral

The Toxicity of Depleted Uranium

OpenAIRE

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 c...

Orientation geochemical survey for uranium exploration using 230Th

International Nuclear Information System (INIS)

Xia Dingliang.

1985-01-01

The distribution of 230 Th in soils, rocks and ores and its relationship with respect to uranium ore formation are discussed for its possible use in geochemical exploration for U. 230 Th, U and Ra, being members of the same decay series, are different in their geochemical behavior upon which the study is orientated. Twenty uranium deposits and occurrences located in western and southern Hunan province are tested. Geochemical data obtained are comprehensively correlated. It is suggested that 230 Th is useful not only in U-Ra disequilibrium study but also in understanding the geochemical evolution of U ores. The data aid to interpret the genesis of uranium deposits and to assess the radioactive anomalies and uranium-bearing zones. Therefore, it can be adopted as a tool for searching in deep-buried uranium ores. The field procedure is rather simple and flexible to meet any geological environment. It is easy to read out and is less influnced by any kind of interference. In case of disequilibrium caused by oxidation and reduction during the period of ore formation it still gives good indication compared with that of radiometry, radonmetry and geochemical sampling for U

Uranium in early proterozoic phosphate-rich metasedimentary rocks of east-central Minnesota

International Nuclear Information System (INIS)

McSwiggen, P.L.; Morey, G.B.; Weiblen, P.W.

1986-01-01

Exploration for unconformity-type uranium deposits in the late 1970s in east-central Minnesota led to the discovery of several uranium-bearing phosphorite occurrences in rocks of early Proterozoic age. In this report the authors use the term phosphorite for a rock or specimen that contains substantial sedimentary apatite (Altschuler et al., 1958). The deposits in Minnesota are especially interesting because of their high uranium content but low metamorphic grade. These occurrences characteristically contain 0.025 to 0.085 percent U and locally as much as 0.157 percent U (Ullmer, 1981), whereas typical primary marine phosphorites have uranium contents of 0.005 to 0.02 percent U (Altschuler et al., 1958). The presence of uranium in a marine phosphorite generally is explained by either the replacement of calcium in the apatite crystal structure or the adsorption of uranium in admixed organic matter and cryptocrystalline apatite. In east-central Minnesota the uranium is closely associated with the finely crystalline apatite, but the uranium has also been involved in several episodes of remobilization and redeposition. Thus, even though the phosphorite deposits are an interesting geologic phenomenon in themselves, they also are important as a possible source for epigenetic uranium deposits that may occur in the area

Uranium fixation by mineralization at the redox front

International Nuclear Information System (INIS)

Isobe, Hiroshi

1998-01-01

The behavior of actinide elements including uranium in geomedia is controlled by redox conditions. Under the oxidized conditions, uranium forms uranyl ion (UO 2 2+ ) and its complexes, and dissolves in ground water. Under the reduced conditions, U(IV) has much lower solubility than uranyl ion. In the Koongarra uranium deposit, Australia, lead-bearing uraninite, uranyl lead oxide and uranyl silicate minerals occur in the unweathered, primary ore zone, and uranyl phosphate minerals occur in the weathered, secondary ore zone. Between unweathered and weathered zones, the transition zone exists as a redox front. In the transition zone, graphite and sulfide minerals react as reducing agents for species dissolved in ground water. By SEM, spherical grains of uraninite were observed in veins with graphite. Pyrite had coffinite rim with crystals of uraninite. Calculation based on the ground water chemistry and hydrology at Koongarra shows that the uranium in the transition zone may be fixed from the ground water. In the Koongarra transition zone, recent mineralization of uranium by reduction takes place. Mineralization is much stronger fixation mechanism than adsorption on clay minerals. Pyrite in the buffer materials of possible radioactive waste repositories can fix radionuclides in oxidized ground water by mineralization with reducing reactions. (author)

Fluid inclusion and oxygen isotope studies of the Nabarlek and Jabiluka uranium deposits, Northern Territory, Australia

International Nuclear Information System (INIS)

Ypma, P.J.M.; Fuzikawa, K.

1980-01-01

We lack a basic understanding of the solutions producing the uranium deposits of the Alligator Rivers Uranium Field (ARUF). Several theories have been proposed ranging from syngenetic, epigenetic hydrothermal, epigenetic metamorphogenic, surficial origin (Ferguson et al., this volume), and mobilization by evaporite deposits. As for a precipitation mechanism, we do not seem to find much beyond the presence of graphite in some ore-bearing and intra-formational strata, and pre-uranium sulphides, none of which reducing factors are common throughout all ore bodies. This study was initiated with the aim of obtaining direct fluid inclusion evidence of the solution transport and precipitation of uranium

Uranium recovery from AVLIS slag

International Nuclear Information System (INIS)

D'Agostino, A.E.; Mycroft, J.R.; Oliver, A.J.; Schneider, P.G.; Richardson, K.L.

2000-01-01

Uranium metal for the Atomic Vapor Laser Isotope Separation (AVLIS) project was to have been produced by the magnesiothermic reduction of uranium tetrafluoride. The other product from this reaction is a magnesium fluoride slag, which contains fine and entrained natural uranium as metal and oxide. Recovery of the uranium through conventional mill leaching would not give a magnesium residue free of uranium but to achieve more complete uranium recovery requires the destruction of the magnesium fluoride matrix and liberation of the entrapped uranium. Alternate methods of carrying out such treatments and the potential for recovery of other valuable byproducts were examined. Based on the process flowsheets, a number of economic assessments were performed, conclusions were drawn and the preferred processing alternatives were identified. (author)

The case against uranium mining

International Nuclear Information System (INIS)

Robotham, F.P.

1980-01-01

Australia is a potential uranium supplier. The case against uranium mining is presented. Biological effects of radiation, risks involved in reactor operation and the problems of waste disposal are discussed

Remote identification of potential polar bear maternal denning habitat in northern Alaska using airborne LiDAR

Science.gov (United States)

Jones, B. M.; Durner, G. M.; Stoker, J.; Shideler, R.; Perham, C.; Liston, G. E.

2013-12-01

Polar bear (Ursus maritimus) populations throughout the Arctic are being threatened by reductions in critical sea ice habitat. Throughout much of their range, polar bears give birth to their young in winter dens that are excavated in snowdrifts. New-born cubs, which are unable to survive exposure to Arctic winter weather, require 2-3 months of the relatively warm, stable, and undisturbed environment of the den for their growth. In the southern Beaufort Sea (BS), polar bears may den on the Alaskan Arctic Coastal Plain (ACP).The proportion of dens occurring on land has increased because of reductions in stable multi-year ice, increases in unconsolidated ice, and lengthening of the fall open-water period. Large portions of the ACP are currently being used for oil and gas activities and proposed projects will likely expand this footprint in the near future. Since petroleum exploration and development activities increase during winter there is the potential for human activities to disturb polar bears in maternal dens. Thus, maps showing the potential distribution of terrestrial denning habitat can help to mitigate negative interactions. Prior remote sensing efforts have consisted of manual interpretation of vertical aerial photography and automated classification of Interferometric Synthetic Aperture (IfSAR) derived digital terrain models (DTM) (5-m spatial resolution) focused on the identification of snowdrift forming landscape features. In this study, we assess the feasibility of airborne Light Detection and Ranging (LiDAR) data (2-m spatial resolution) for the automated classification of potential polar bear maternal denning habitat in a 1,400 km2 area on the central portion of the ACP. The study region spans the BS coast from the Prudhoe Bay oilfield in the west to near Point Thompson in the east and extends inland from 10 to 30 km. Approximately 800 km2 of the study area contains 19 known den locations, 51 field survey sites with information on bank height and

Uranium-Series Disequilibria in the Groundwater of the Shihongtan Sandstone-Hosted Uranium Deposit, NW China

Directory of Open Access Journals (Sweden)

Xinjian Peng

2015-12-01

Full Text Available Uranium (U concentration and the activities of 238U, 234U, and 230Th were determined for groundwaters, spring waters, and lake water collected from the Shihongtan sandstone-hosted U ore district and in the surrounding area, NW China. The results show that the groundwaters from the oxidizing aquifer with high dissolved oxygen concentration (O2 and oxidation-reduction potential (Eh are enriched in U. The high U concentration of groundwaters may be due to the interaction between these oxidizing groundwaters and U ore bodies, which would result in U that is not in secular equilibrium. Uranium is re-precipitated as uraninite on weathered surfaces and organic material, forming localized ore bodies in the sandstone-hosted aquifer. The 234U/238U, 230Th/234U, and 230Th/238U activity ratios (ARs for most water samples show obvious deviations from secular equilibrium (0.27–2.86, indicating the presence of water-rock/ore interactions during the last 1.7 Ma and probably longer. The 234U/238U AR generally increases with decreasing U concentrations in the groundwaters, suggesting that mixing of two water sources may occur in the aquifer. This is consistent with the fact that most of the U ore bodies in the deposit have a tabular shape originati from mixing between a relatively saline fluid and a more rapidly flowing U-bearing meteoric water.

Discussion on the genesis and mineralization of sandstone type uranium deposit in the southern-central Longchuanjiang basin, western Yunnan province

International Nuclear Information System (INIS)

Cai Yuqi; Li Mangen

2002-01-01

The author mainly discusses the character of the depositional systems, geological structures and ore-bearing series in the south-central Longchuanjiang basin, and points out that the uranium mineralization is closely related to the two depositional discontinuities caused by the tectonic evolution. Based on the characteristics of uranium mineralization in the area, pitchblende, uranium blacks and phosphuranylite are discovered in No. 382 uranium deposit and radiometric super-micro-minerals in No. 381 deposit. The research on the uranium mineralization age in No. 382 deposit shows that the mineralization in the south-central part of the basin has genetically multi-staged

Application of self-potential method in uranium exploration - a case study from Arbail, Karnataka, India

International Nuclear Information System (INIS)

Anantharaman, K.B.; Narasimha Rao, B.; Sethuram, S.; Rao, K.K.

1986-01-01

The application of non-radiometric geophysical methods like magnetic, electrical resistivity, induced polarisation, electromagnetic and seismic for uranium exploration has been discussed by many workers. In thispaper it has been demonstrated that the self-potential technique which is simple, fast and cheap can also be effectively and meaningfully employed. For this purpose, a case study from Arbail (Lat 14 0 , 50' 40'', Long 74 0 38' 25''), India where uranium mineralisation is known to occur in association with sulphides, is presented. The method of downward continuation is used to estimate the depth to the top of the target and the results thus obtained are correlated with the data obtained from subsequent borehole drilling. (author)

The relational of Mesozoic volcanism to uranium mineralization in Guyuan-Hongshanzi area

International Nuclear Information System (INIS)

Wu Rengui; Xu Zhe; Yu Zhenqing; Jiang Shan; Shen Kefeng

2011-01-01

Based on the time of Mesozoic volcanism,the characteristic of major and trace element, and REE pattern of the volcanic rocks in Guyuan-Hongshanzi area, The Mesozoic volcanism can be divided into the early cycle and later cycle during the Early Cretaceous, and it's magma series is classified in two sub-series, one is alkaline series of trachyte dominated and another is subalkaline series of rhyolite dominated. The relations between Mesozoic volcanism and uranium mineralization is mainly shown in four aspects: (1) Uranium mineralization controlled by the coexist of two magma series; (2) Uranium mineralization controlled by superhypabyssal porphyry body in later cycle volcanism during the Early Cretaceous; (3) The porphyry body close to uranium mineralization,bearing the genesis characteristics of crust-mantle action; and (4) High Si and K content in the chemical composition of the mineralization volcanic rocks. (authors)

Current uranium activities in Pakistan

International Nuclear Information System (INIS)

Moghal, M.Y.

2001-01-01

The rocks of Siwaliks group in Pakistan, extending from Kashmir in the east through Potwar Plateau, Bannu Basin and Sulaiman range up to the Arabian Sea in the west have been extensively explored for uranium. The Dhok Pathan Formation, which is younger member of the middle Siwaliks has been aeroradiometrically surveyed and extensively prospected on foot. A large number of anomalies were encountered in Kashmir, Potwar Plateau, Bannu Basin and Sulaiman range. While exploratory work in Sulaiman range and Bannu Basin yielded a few workable deposits, none of the anomalous areas yielded an ore grade concentration in Potwar Plateau. As conventional exploration activities in Potwar Plateau did not yield any ore grade concentration therefore a resource potential evaluation programme through geological modeling was started under the guidance of an IAEA expert. The volcanic material found in the middle Siwaliks is considered to be the main source of uranium and siliceous cement in the sandstones. These findings have considerably increased uranium potential in Siwaliks. The tectonic deformation during and after the deposition of Siwaliks is considered to be the main reason for mobilization of uranium, while permeability barriers and upward movement of oil products may provide trappings for the mobilized uranium. Through this survey south western part of Potwar Plateau being relatively less deformed is considered to provide conducive environments for concentration of uranium. Low grade uranium concentrations have also been discovered in carbonatites in northern part of Pakistan. Preliminary exploration in Sallai Patti carbonatite through drilling supplemented by trenching, pitting and aditing, subsurface continuation of surface concentrations has been confirmed. The ore contains about 200 ppm of uranium and 3 to 4% phosphate in addition to magnetite, rare metals and rare earths. It has been demonstrated on laboratory/pilot scale that the concentrations of uranium and phosphate

Uranium-enriched granites in Sweden

International Nuclear Information System (INIS)

Wilson, M.R.; Aakerblom, G.

1980-01-01

Granites with uranium contents higher than normal occur in a variety of geological settings in the Swedish Precambrian, and represent a variety of granite types and ages. They may have been generated by the anatexis of continental crust or processes occurring at a much greater depth. They commonly show enrichment in F, Sn, W and/or Mo. Only in one case is an important uranium mineralization thought to be directly related to a uranium-enriched granite, while the majority of epigenetic uranium mineralizations with economic potential are related to hydrothermal processes in areas where the bedrock is regionally uranium-enhanced. (author)

Uranium enriched granites in Sweden

International Nuclear Information System (INIS)

Wilson, M.R.; Aakerblom, G.

1980-01-01

Granites with uranium contents higher than normal occur in a variety of geological settings in the Swedish Precambrian, and represent a variety of granite types and ages. They may have been generated by (1) the anatexis of continental crust (2) processes occurring at a much greater depth. They commonly show enrichement in F, Sn, W and/or Mo. Only in one case is an important uranium mineralization thought to be directly related to a uranium-enriched granite, while the majority of epigenetic uranium mineralizations with economic potential are related to hydrothermal processes in areas where the bedrock is regionally uranium-enhanced. (Authors)

Acidic aqueous uranium electrodeposition for target fabrication

International Nuclear Information System (INIS)

Saliba-Silva, A.M.; Oliveira, E.T.; Garcia, R.H.L.; Durazzo, M.

2013-01-01

Direct irradiation of targets inside nuclear research or multiple purpose reactors is a common route to produce 99 Mo- 99m Tc radioisotopes. The electroplating of low enriched uranium over nickel substrate might be a potential alternative to produce targets of 235 U. The electrochemistry of uranium at low temperature might be beneficial for an alternative route to produce 99 Mo irradiation LEU targets. Electrodeposition of uranium can be made using ionic and aqueous solutions producing uranium oxide deposits. The performance of uranium electrodeposition is relatively low because a big competition with H 2 evolution happens inside the window of electrochemical reduction potential. This work explores possibilities of electroplating uranium as UO 2 2+ (Uranium-VI) in order to achieve electroplating uranium in a sufficient amount to be commercially irradiated in the future Brazilian RMB reactor. Electroplated nickel substrate was followed by cathodic current electrodeposition from aqueous UO 2 (NO 3 ) 2 solution. EIS tests and modeling showed that a film formed differently in the three tested cathodic potentials. At the lower level, (-1.8V) there was an indication of a double film formation, one overlaying the other with ionic mass diffusion impaired at the interface with nickel substrate as showed by the relatively lower admittance of Warburg component. (author)

Topical and working papers on uranium resources and availability

International Nuclear Information System (INIS)

Basic topics relative to world-wide resources and availability of uranium resources; potential for recovery of uranium from mill tailings in Canada; uranium from seawater; depleted uranium as an energy source; world uranium requirements in perspective

Uranium Sequestration by Aluminum Phosphate Minerals in Unsaturated Soils

International Nuclear Information System (INIS)

Jerden, James L. Jr.

2007-01-01

A mineralogical and geochemical study of soils developed from the unmined Coles Hill uranium deposit (Virginia) was undertaken to determine how phosphorous influences the speciation of uranium in an oxidizing soil/saprolite system typical of the eastern United States. This paper presents mineralogical and geochemical results that identify and quantify the processes by which uranium has been sequestered in these soils. It was found that uranium is not leached from the saturated soil zone (saprolites) overlying the deposit due to the formation of a sparingly soluble uranyl phosphate mineral of the meta-autunite group. The concentration of uranium in the saprolites is approximately 1000 mg uranium per kg of saprolite. It was also found that a significant amount of uranium was retained in the unsaturated soil zone overlying uranium-rich saprolites. The uranium concentration in the unsaturated soils is approximately 200 mg uranium per kg of soil (20 times higher than uranium concentrations in similar soils adjacent to the deposit). Mineralogical evidence indicates that uranium in this zone is sequestered by a barium-strontium-calcium aluminum phosphate mineral of the crandallite group (gorceixite). This mineral is intimately inter-grown with iron and manganese oxides that also contain uranium. The amount of uranium associated with both the aluminum phosphates (as much as 1.4 weight percent) has been measured by electron microprobe micro-analyses and the geochemical conditions under which these minerals formed has been studied using thermodynamic reaction path modeling. The geochemical data and modeling results suggest the meta-autunite group minerals present in the saprolites overlying the deposit are unstable in the unsaturated zone soils overlying the deposit due to a decrease in soil pH (down to a pH of 4.5) at depths less than 5 meters below the surface. Mineralogical observations suggest that, once exposed to the unsaturated environment, the meta-autunite group

Waste management implications of concentrating slimes - characteristics and potential problems

International Nuclear Information System (INIS)

1986-05-01

This report describes the geotechnical, geochemical and environmental characteristics of fine-grained uranium tailings (slimes) which may influence both short- and long-term management of slime-enriched uranium tailings impoundments. Properties of slimes are compared and contrasted with those of sand tailings using field and laboratory data primarily from naturally segregated tailings in the Elliot Lake area, Ontario and Northern Saskatchewan uranium-bearing regions of Canada. Key management considerations are included

Hydrogeological analysis applied to regional evaluation of sandstone-type uranium ore-formation in sedimentary basins

International Nuclear Information System (INIS)

Xu Laisheng

2005-01-01

The main purpose of regional evaluation of uranium ore-formation is to preliminarily divide environmental zones and to delineate favourable areas for uranium ore-formation in order to provide basis for further detailed prospecting work. Of the various kinds of prospecting work, the hydrogeologic work should be mainly carried out in following aspects: division of hydrogeological units, the determination of artesian water-bearing system and the identification of prospecting target horizon; the analysis on hydrodynamic regime, the analysis on hydrogeochemical environments, the paleo-hydrogeologic analysis and the delineation of redox front and favourable area for uranium ore-formation. (author)

Geology and uranium mineralization in the eastern part of the Kani Basin, Gifu, Central Japan

International Nuclear Information System (INIS)

Kobayashi, Takao

1989-01-01

The Misano and Utozaka uranium deposits in the eastern part of the Kani Basin are within Miocene nonmarine sediments which unconformably overlie Paleozoic-Mesozoic sediments and Cretaceous-Paleogene granites. These deposits are classified as sandstone type deposits structurally controlled by palaeo-channel structures formed on the pre-Miocene basement rocks. The host rock is the Kani lignite-bearing formation which is the lowermost sequence of the Kani Group. The age of the formation was estimated to be 20-19 Ma by fission track dating. The mineralized host sediments consist of conglomerates, arkosic, tuffaceous and carbonaceous sandstones. Although no primary uranium mineral was identified to date, it is considered that uranium is present in uranous form. The mineralization was strongly controlled by a fault structure within the basement granites as well as the channel structure formed on the basement rocks, especially on the granites. The enriched ore zone of the Misano deposit distributes within the basal part of the Kani lignite-bearing formation above the basement fault structure and in the palaeo-channel downward from the fault structure. The basement granites were also mineralized along the fault structure. Groundwater leached uranium form the basement granites, and migrated along the fault structure to the host sediments to form the deposite. (Kako, I.)

Development of technology for reduction of radiotoxicity of uranium mixture

International Nuclear Information System (INIS)

Kim, Kwangwook; Lee, E. H.; Yang, H. B.

2012-03-01

The phase 1 of this research project was carried out as a project entitled 'Development of technology for reduction of actinide radiotoxicity' in 2007 to 2009. Its phase 2 was carried out as a project entitled 'Development of technology for reduction of radiotoxicity of uranium mixture' in 2010 to 2011. Five unit research items to accomplish it such as evaluation of dissolution and aquatic chemistry characteristics of U, TRU, RE, and etc elements evaluation of chemical and electrolytic dissolution characteristics of U and SIMFUEL oxides evaluation of removal of environmentally-detrimental elements, and high purity precipitation of uranium evaluation of salt-free electrolytic decarbonation characteristics, and recovery of used carbonate salt, and development of the process to treat uranium mixture materials and the relevant unit equipments and system with engineering concept. were carried out. The obtained results were as follows. -Evaluation of chemical characteristics of several uranium oxide materials and verification of insolubility properties of TRU oxides in carbonate media -Suggestion of the optimal conditions for dissolutions of uranium and SIMFUEL oxides - Development of technology for co-precipitation of environmentally-detrimental elements - Development of an electrolytic recycle way of used carbonate salt solution - Suggestion of a new conceptual process, named COL process to treat spent nuclear fuel, uranium-bearing wastes with high and low contents

Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach.

Science.gov (United States)

Mudd, Gavin M

2008-02-01

The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting.

Radon releases from Australian uranium mining and milling projects: assessing the UNSCEAR approach

International Nuclear Information System (INIS)

Mudd, Gavin M.

2008-01-01

The release of radon gas and progeny from the mining and milling of uranium-bearing ores has long been recognised as a potential radiological health hazard. The standards for exposure to radon and progeny have decreased over time as the understanding of their health risk has improved. In recent years there has been debate on the long-term releases (10,000 years) of radon from uranium mining and milling sites, focusing on abandoned, operational and rehabilitated sites. The primary purpose has been estimates of the radiation exposure of both local and global populations. Although there has been an increasing number of radon release studies over recent years in the USA, Australia, Canada and elsewhere, a systematic evaluation of this work has yet to be published in the international literature. This paper presents a detailed compilation and analysis of Australian studies. In order to quantify radon sources, a review of data on uranium mining and milling wastes in Australia, as they influence radon releases, is presented. An extensive compilation of the available radon release data is then assembled for the various projects, including a comparison to predictions of radon behaviour where available. An analysis of cumulative radon releases is then developed and compared to the UNSCEAR approach. The implications for the various assessments of long-term releases of radon are discussed, including aspects such as the need for ongoing monitoring of rehabilitation at uranium mining and milling sites and life-cycle accounting

Influence of uranyl speciation and iron oxides on uranium biogeochemical redox reactions

Energy Technology Data Exchange (ETDEWEB)

Stewart, B.D.; Amos, R.T.; Nico, P.S.; Fendorf, S.

2010-03-15

Uranium is a pollutant of concern to both human and ecosystem health. Uranium's redox state often dictates its partitioning between the aqueous- and solid-phases, and thus controls its dissolved concentration and, coupled with groundwater flow, its migration within the environment. In anaerobic environments, the more oxidized and mobile form of uranium (UO{sub 2}{sup 2+} and associated species) may be reduced, directly or indirectly, by microorganisms to U(IV) with subsequent precipitation of UO{sub 2}. However, various factors within soils and sediments may limit biological reduction of U(VI), inclusive of alterations in U(VI) speciation and competitive electron acceptors. Here we elucidate the impact of U(VI) speciation on the extent and rate of reduction with specific emphasis on speciation changes induced by dissolved Ca, and we examine the impact of Fe(III) (hydr)oxides (ferrihydrite, goethite and hematite) varying in free energies of formation on U reduction. The amount of uranium removed from solution during 100 h of incubation with S. putrefaciens was 77% with no Ca or ferrihydrite present but only 24% (with ferrihydrite) and 14% (no ferrihydrite) were removed for systems with 0.8 mM Ca. Imparting an important criterion on uranium reduction, goethite and hematite decrease the dissolved concentration of calcium through adsorption and thus tend to diminish the effect of calcium on uranium reduction. Dissimilatory reduction of Fe(III) and U(VI) can proceed through different enzyme pathways, even within a single organism, thus providing a potential second means by which Fe(III) bearing minerals may impact U(VI) reduction. We quantify rate coefficients for simultaneous dissimilatory reduction of Fe(III) and U(VI) in systems varying in Ca concentration (0 to 0.8 mM), and using a mathematical construct implemented with the reactive transport code MIN3P, we reveal the predominant influence of uranyl speciation, specifically the formation of uranyl

National Uranium Resource Evaluation: Marfa Quadrangle, Texas

International Nuclear Information System (INIS)

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

1982-09-01

The uranium favorability of the Marfa 1 0 by 2 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 Tertiary 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

Hydrogeochemical radioactive features and prospecting in granopegmatite type uranium ore district in Danfeng area

International Nuclear Information System (INIS)

Feng Zhangsheng

2011-01-01

Hydrochemical radioactive prospecting plays an important role in the all stages of grano-pegmatite type uranium deposit exploration in Danfeng area dut to its fast, simple, economic and high effective advantage. Radioactive anomalous halo in the shallow underground water has identical distribution scopes with the ore-bearing biotite granite-pegmatite, which can be used to delineate uranium ore-forming prospective area, reconnaissance area and detailed prospecting area. Deep underground water close to the ore is characterized by hydrogeochemical radioactive features with high uranium and radon content. Through prospecting engineering of radioactive hydrogeochemical, the situation of blind ore bodies can be used to guide the layout. (authors)

Uranium solution mining: comparison of New Mexico with South Texas

International Nuclear Information System (INIS)

Conine, W.D.

1980-01-01

In-situ uranium-leaching or solution-mining operations are currently underway in both south Texas and Wyoming. Mobil Oil Corporation is in the process of applying solution-mining technology, such as that developed at the O'Hern facility in south Texas, to uranium orebodies located near Crownpoint, New Mexico. The O'Hern facility uses an alkaline-leach process to bring the uranium to the surface, where it is removed from solution using ion-exchange resin and chemical precipitation. Line-drive and five-spot well field patterns are used to inject and recover the leach solutions. Although details of ore occurrence in New Mexico differ from those in south Texas, laboratory, engineering-design, and field-hydrology tests indicate that solution mining of uranium should be feasible in New Mexico. To determine the commercial feasibility, Mobil is proceeding with the construction of pilot-plant facilities for a 75-gallon-perminute (gpm) test at an orebody near Crownpoint. The pilot test will use five-spot patterns at various spacings for production of uranium-bearing leachate. Initial surface processing will be the same as that used in south Texas

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

International Nuclear Information System (INIS)

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 leads 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

Initial results of uranium prospecting in Baluchistan, Iran

International Nuclear Information System (INIS)

Hemmer, C.

1980-01-01

Uranium prospecting in Baluchistan, SE-Iran, led to the discovery of uranium occurrences at the northern rim of the undrained Jaz Murian Depression. All known uranium occurrences are epigenetic local enrichments of no economic significance which originate from mobilization of uranium from Tertiary acidic magmatic rocks. The great extent of both the uranium source and the host areas indicate significant uranium mobilization and a possible economic potential for the area as a uranium province in the future. (orig.) [de

Study on Kalimantan uranium province: The assessment on uranium mineralization of metamorphic and granitic rocks at Schwaner mountains

International Nuclear Information System (INIS)

Tjokrokardono, Soeprapto

2002-01-01

Uranium exploration activities done by CEA-BATAN had discovered uranium occurrences as the radiometric and uranium content anomalies at metamorphic and granite rocks of Schwaner Mountains, Kalimantan. A part of the occurrences on metamorphic rocks at Kalan basin has been evaluated and be developed onto follow-up step of prospecting by construction of some drilling holes and an exploration adit. In order to increase the national uranium resources, it is necessarily to extent the exploration activity to out side or nearby of Kalan basin. The goal of this assessment is to understand the uranium accumulation mechanism at Pinoh metamorphic rocks of Kalan Kalimantan and to delineate areas that uranium may exist. The assessment was based on the aspect of geology, anomaly of radioactivity and uranium contents, tectonics and alterations. Pinoh metamorphic rocks which is influenced by Sukadana granite intrusion are the high potential rocks for the uranium accumulation, because the intrusion contains a relatively high of U, Th, Cu, Zn, Nb, Mn, and W. The potential rock distributions are in between G. Ransa granite intrusion at the east and Kotabaru granite intrusions at the west. The mineralizations are categorized as vein type deposits of granitic association

Uranium distribution in Brazilian granitic rocks. Identification of uranium provinces

International Nuclear Information System (INIS)

Tassinari, C.G.G.

1993-01-01

The research characterized and described uranium enriched granitoids in Brazil. They occur in a variety of tectonic environments and are represented by a variety granite types of distinct ages. It may be deduced that in general they have been generated by partial melting process of continental crust. However, some of them, those with tonality composition, indicate a contribution from mantle derived materials, thus suggesting primary uranium enrichment from the upper mantle. Through this study, the identification and characterization of uranium enriched granite or uranium provinces in Brazil can be made. This may also help identify areas with potential for uranium mineralization although it has been note that uranium mineralization in Brazil are not related to the uranium enrichment process. In general the U-anomalous granitoids are composed of granites with alkaline composition and granite ''sensu strictu'' which comprise mainly of syenites, quartz-syenites and biotite-hornblende granites, with ages between 1,800 - 1,300 M.a. The U-anomalous belongings to this period present high Sr initial ratios values, above 0.706, and high Rb contents. Most of the U-enriched granitoids occur within ancient cratonic areas, or within Early to Mid-Proterozoic mobile belts, but after their cratonization. Generally, these granitoids are related to the border zones of the mobile belts or deep crustal discontinuity. Refs, 12 figs, 3 tabs

The Toxicity of Depleted Uranium

Directory of Open Access Journals (Sweden)

Wayne Briner

2010-01-01

Full Text Available 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.

Radium-bearing waters in the Upper Silesian Coal Basin

International Nuclear Information System (INIS)

Tomza, I.; Lebecka, J.; Pluta, I.

1986-01-01

Natural waters with a high radium content occuring in underground workings of coal mines in Upper Silesia are described. Above 1500 water samples from carbonifereous aquifers were taken and the concentration of 226 Ra was measured. In about 100 samples also uranium was determined. The 226 Ra concentration varied in a wide range from 0.01 kBq/m 3 to 270 kBq/m 3 , while the uranium content was usually much lower than one could expect from the equilibrium between radium and uranium. It was observed that the 226 Ra concentration increases with mineralization of water, however the correlation was rather poor. Two types of radium-bearing waters were distinguished. Waters type A - containing Ba 2+ ions and waters type B - containing SO 4 2- ions. Waters type A are always reach in radium and usually have higher concentration of 226 Ra than waters type B. The described waters have one of the highest radium concentration which have been found so far in the natural environment. (author)

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

Science.gov (United States)

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...

Transformations of highly enriched uranium into metal or oxide

International Nuclear Information System (INIS)

Nollet, P.; Sarrat, P.

1964-01-01

The enriched uranium workshops in Cadarache have a double purpose on the one hand to convert uranium hexafluoride into metal or oxide, and on the other hand to recover the uranium contained in scrap materials produced in the different metallurgical transformations. The principles that have been adopted for the design and safety of these workshops are reported. The nuclear safety is based on the geometrical limitations of the processing vessels. To establish the processes and the technology of these workshops, many studies have been made since 1960, some of which have led to original achievements. The uranium hexafluoride of high isotopic enrichment is converted either by injection of the gas into ammonia or by an original process of direct hydrogen reduction to uranium tetrafluoride. The uranium contained m uranium-zirconium metal scrap can be recovered by combustion with hydrogen chloride followed treatment of the uranium chloride by fluorine in order to obtain the uranium in the hexafluoride state. Recovery of the uranium contained m various scrap materials is obtained by a conventional refining process combustion of metallic scrap, nitric acid dissolution of the oxide, solvent purification by tributyl phosphate, ammonium diuranate precipitation, calcining, reduction and hydro fluorination into uranium tetrafluoride, bomb reduction by calcium and slag treatment. Two separate workshops operate along these lines one takes care of the uranium with an isotopic enrichment of up to 3 p. 100, the other handles the high enrichments. The handling of each step of this process, bearing in mind the necessity for nuclear safety, has raised some special technological problems and has led to the conception of new apparatus, in particular the roasting furnace for metal turnings, the nitric acid dissolution unit, the continuous precipitator and ever safe filter and dryer for ammonium diuranate, the reduction and hydro fluorination furnace and the slag recovery apparatus These are

U.S. reference paper on the potential and limitations of uranium to meet the anticipated needs of nuclear energy

International Nuclear Information System (INIS)

1978-10-01

A framework is provided to analyze the interrelationship between uranium availability and the deployment of fast breeder and converter reactors. Included are models which can be used to estimate the uranium price for economic parity between breeders and converters, the dates for economical commercialization of fast breeders, and the effect of breeder deployment on uranium availability. Factors such as energy demand, resources and economics which are dominant in decisions as to potential breeder commercialization are discussed. Included are examples which show that breeder breakeven introduction date could fall between the year 2000 and well beyond 2025. A principal conclusion is that the break-even introduction date is very sensitive to uncertainty in the estimate of increase in capital costs of the breeder relative to the LWR, the estimates of power demand, and the estimate of the uranium resource base available at less than $130/kg (e.g. consideration of the IUREP estimates of speculative resources which if available doubles or triples the resource base)

50 years of uranium metal production in Uranium Metal Plant, BARC, Trombay

International Nuclear Information System (INIS)

2009-01-01

The Atomic Energy Programme in India, from the very beginning, has laid emphasis on indigenous capabilities in all aspects of nuclear technology. This meant keeping pace with developments abroad and recognizing the potentials of indigenous technologies. With the development of nuclear programme in India, the importance of uranium was growing at a rapid pace. The production of reactor grade uranium in India started in January 1959 when the first ingot of nuclear pure uranium was discharged using CTR process at Trombay. The decision to set up a uranium refinery to purify the crude uranium fluoride, obtained as a by-product of the DAE's Thorium Plant at Trombay, and to produce nuclear grade pure uranium metal was taken at the end of 1956. The task was assigned to the 'Project Fire Wood Group'. The main objective of the plant was to produce pure uranium metal for use in the Canada India Reactor and Zerlina. Besides this, it was to function as a pilot plant to collect operational data and to train personnel for larger plants to be set up in future. The plant designing and erection work was entrusted to Messrs. Indian Rare Earths Ltd.

Uranium conversion wastes

International Nuclear Information System (INIS)

Vicente, R.; Dellamano, J.C.

1989-12-01

A set of mathematical equations was developed and used to estimate the radiological significance of each radionuclide potentially present in the uranium refining industry effluents. The equations described the evolution in time of the radionuclides activities in the uranium fuel cycle, from mining and milling, through the yellowcake, till the conversion effluents. Some radionuclides that are not usually monitored in conversion effluents (e.g. Pa-231 and Ac-227) were found to be potentially relevant from the radiological point of view in conversion facilities, and are certainly relevant in mining and milling industry, at least in a few waste streams. (author) [pt

A new opportunity for Australian uranium

International Nuclear Information System (INIS)

1994-07-01

This study analyses the outlook for the world uranium industry and includes projections of uranium demand, supply and prices over the next decade and a comparison with other forecasts. The potential increases in Australian output are quantified, under both continuation of the three mine policy and an open mine policy, as well as the potential impact on the world uranium market, using the well known ORANI model of the Australian economy. It is estimated that Australian output could almost double by 2004 if the three mine policy were abolished. 53 refs., 20 tabs., 6 figs

A new opportunity for Australian uranium

Energy Technology Data Exchange (ETDEWEB)

NONE

1994-07-01

This study analyses the outlook for the world uranium industry and includes projections of uranium demand, supply and prices over the next decade and a comparison with other forecasts. The potential increases in Australian output are quantified, under both continuation of the three mine policy and an open mine policy, as well as the potential impact on the world uranium market, using the well known ORANI model of the Australian economy. It is estimated that Australian output could almost double by 2004 if the three mine policy were abolished. 53 refs., 20 tabs., 6 figs.

Chemical Separation of Fission Products in Uranium Metal Ingots from Electrolytic Reduction Process

International Nuclear Information System (INIS)

Lee, Chang-Heon; Kim, Min-Jae; Choi, Kwang-Soon; Jee, Kwang-Yong; Kim, Won-Ho

2006-01-01

Chemical characterization of various process materials is required for the optimization of the electrolytic reduction process in which uranium dioxide, a matrix of spent PWR fuels, is electrolytically reduced to uranium metal in a medium of LiCl-Li 2 O molten at 650 .deg. C. In the uranium metal ingots of interest in this study, residual process materials and corrosion products as well as fission products are involved to some extent, which further adds difficulties to the determination of trace fission products. Besides it, direct inductively coupled plasma atomic emission spectrometric (ICP-AES) analysis of uranium bearing materials such as the uranium metal ingots is not possible because a severe spectral interference is found in the intensely complex atomic emission spectra of uranium. Thus an adequate separation procedure for the fission products should be employed prior to their determinations. In present study ion exchange and extraction chromatographic methods were adopted for selective separation of the fission products from residual process materials, corrosion products and uranium matrix. The sorption behaviour of anion and tri-nbutylphosphate (TBP) extraction chromatographic resins for the metals in acidic solutions simulated for the uranium metal ingot solutions was investigated. Then the validity of the separation procedure for its reliability and applicability was evaluated by measuring recoveries of the metals added

Nuclear genomic sequences reveal that polar bears are an old and distinct bear lineage.

Science.gov (United States)

Hailer, Frank; Kutschera, Verena E; Hallström, Björn M; Klassert, Denise; Fain, Steven R; Leonard, Jennifer A; Arnason, Ulfur; Janke, Axel

2012-04-20

Recent studies have shown that the polar bear matriline (mitochondrial DNA) evolved from a brown bear lineage since the late Pleistocene, potentially indicating rapid speciation and adaption to arctic conditions. Here, we present a high-resolution data set from multiple independent loci across the nuclear genomes of a broad sample of polar, brown, and black bears. Bayesian coalescent analyses place polar bears outside the brown bear clade and date the divergence much earlier, in the middle Pleistocene, about 600 (338 to 934) thousand years ago. This provides more time for polar bear evolution and confirms previous suggestions that polar bears carry introgressed brown bear mitochondrial DNA due to past hybridization. Our results highlight that multilocus genomic analyses are crucial for an accurate understanding of evolutionary history.

Rock-water interaction involving uranium and thorium isotopes in the fractures of El Berrocal granite, Spain

International Nuclear Information System (INIS)

Ivanovich, M.; Cahmbers, N.; Hernandez-Benitez, A.

1996-01-01

In the framework of a number of R and D programmes, low permeability rocks in which the groundwater flow is governed by fractures are being considered as potentially suitable candidates for the long-term storage of radioactive waste at depth [1]. Such rocks are often one of the main sources of the radionuclides deriving from the natural radioactive decay chains headed by U and Th. This characteristic makes this type of rock very useful in providing geochemical analogues for the behaviour of transuranic radionuclides present in the nuclear waste [2,3]. The main aim of the work reported here is to study in detail the distribution of naturally occurring radionuclides in several types of fracture infill material from the El Berrocal granitic pluton. The pluton in situated at the southern edge of the Spanish Central System and contains a uranium-mineralized quartz vein (UQV) that has been mined for uranium in the past [4]. Groundwaters as well as natural colloids have been sampled from some of the boreholes with the ultimate intention to model rock/water interaction processes which may take place in the water-bearing fractures in the batholith. The second aim of this work has been to date some of the calcite-rich fracture infills derived from the drill cores at depth, especially at water-bearing horizons. (Author)

Occurrence of uranium in the itabiritic iron ore of Morro Agudo on the NE border of the iron Quadrangle/Minas Gerais, Brasilien

International Nuclear Information System (INIS)

Guba, I.

1982-01-01

The precambrian itabirites and hematite ores of the Morro Agudo iron ore mine on the NE border of the Quadrilatero Ferrifero in Minas Gerais/Brazil contain uranium-bearing minerals and rare-earth elements. In association with phosphates they occupy planes of joints, fractures and cleavage in the area of amphibolitic schist which is intercalated in the s 1 -planes of the itabirites and hematite ores. Preliminary analyses of the uranium-bearing minerals were made by energy dispersive X-ray spectrometry and electron microscopy. The results are presented in connection with the lithologic and tectonic features of the Morro Agudo mine. (orig.) [de

The Nopal 1 Uranium Deposit: an Overview

Science.gov (United States)

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

2007-05-01

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

National uranium resource evaluation program. Hydrogeochemical and stream sediment reconnaissance basic data for Oklahoma City NTMS Quadrangle, Oklahoma. Uranium resource evaluation project

International Nuclear Information System (INIS)

1978-01-01

Field and laboratory data are presented for 812 groundwater samples and 847 stream sediment samples. Statistical and areal distributions of uranium and other possibly 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. Based on the results from groundwater sampling, the most promising formations for potential uranium mineralization in the quadrangle are the Permian Bison, Purcell-Salt Plains-Kingman, Fairmont, Dog Creek, Chickasha, Duncan, and Cedar Hills Formations. These units are characterized by relatively high average concentrations of uranium, conductivity, arsenic, calcium, lithium, molybdenum, and sulfate. In addition, groundwaters from the Pennsylvanian Oscar Formation are characterized by values above the 85th percentile for uranium, conductivity, the uranium/sulfate ratio, arsenic, and vanadium. Results of stream sediment sampling indicate that the most promising formations for potential uranium mineralization include the same Permian Formation as indicated by groundwater sampling (Bison, Purcell-Salt Plains-Kingman, Fairmont, Dog-Creek, Chickasha, Duncan, and Cedar Hill Formations) in an area where these formations crop out north of the North Canadian River. Stream sediment samples from this area are characterized by concentrations above the 85th percentile for uranium, thorium, arsenic, lithium, manganese, and vanadium

The potential of centrifugal casting for the production of near net shape uranium parts

International Nuclear Information System (INIS)

Robertson, E.

1993-09-01

This report was written to provide a detailed summary of a literature survey on the near net shape casting process of centrifugal casting. Centrifugal casting is one potential casting method which could satisfy the requirements of the LANL program titled Near Net Shape Casting of Uranium for Reduced Environmental, Safety and Health Impact. In this report, centrifugal casting techniques are reviewed and an assessment of the ability to achieve the near net shape and waste minimization goals of the LANL program by using these techniques is made. Based upon the literature reviewed, it is concluded that if properly modified for operation within a vacuum, vertical or horizontal centrifugation could be used to safely cast uranium for the production of hollow, cylindrical parts. However, for the production of components of geometries other than hollow tubes, vertical centrifugation could be combined with other casting methods such as semi-permanent mold or investment casting

Solution (in situ leach) mining of uranium: an overview

International Nuclear Information System (INIS)

Kuhaida, A.J. Jr.; Kelly, M.J.

1978-01-01

Increases in the demand for and price of uranium have made in-situ mining an attractive alternative to the open-pit and underground U mining methods. Up to 50% of the known ore-bearing sandstone in the western U.S. can be mined using the in-situ mining method. In-situ mining also offers a significant environmental advantage. Restoration of the contaminated groundwater is discussed

The prospecting and - research of uranium in Brazil

International Nuclear Information System (INIS)

Forman, J.

1981-01-01

The Nuclebras methodology used for the uranium prospecting and uranium research is described. Tjhe uraniferous potential is evaluated and the historical aspects of the four mainly uranium reserves are presented. (L.H.L.L.) [pt

The behavior of uranium in the soil/plant system with special consideration of the uranium input by mineral phosphorus fertilizer

International Nuclear Information System (INIS)

Setzer, Sascha

2014-01-01

The fate of uranium in the environment and, consequently, its hazard potential for human beings is still discussed controversially in the scientific literature. Mineral phosphorous fertilizer can contain uranium as impurity, so that their application can cause an additional input of uranium into agricultural environments. It is still unclear whether and to what extent fertilizer-derived uranium can enter the human food chain by the consumption of contaminated waters or vegetable crop products. The mobility and availability of uranium in the agricultural ecosystem is mainly determined by its behavior in the pedosphere. Due to interactions with organic and inorganic components, the pedosphere is an effective storage and filter system for pollutants and thus plays an important role for the fate of uranium in the environment. In order to improve the assessment of the hazard potential, the present study investigates the behavior of uranium in the soil/plant-system with a focus on the uranium input by mineral phosphorous fertilizer. The specific objectives were (A) to investigate the general distribution of uranium in soils, (B) to determine the effect of CaCO 3 on the sorption behavior of uranium and to quantify the effects of (C - D) varying substrate properties and (E) the application of phosphorus fertilizers on the uranium uptake by ryegrass. The results of these experiments imply that the use of mineral phosphorous fertilizers does not pose an acute risk within the meaning of consumer protection. The studied soils predominantly had a high to very high sorption capability for uranium. At the same time, a small soil-to-plant-transfer of uranium was determined, where the majority of uranium accumulated in/to the plant roots. The availability of uranium in soils and its uptake by plants can thus be classified as generally low. Furthermore, some soil parameters were identified which seem to favor a higher uranium-availability. This study found that very high and very

In-SEM Raman microspectroscopy coupled with EDX - a case study of uranium reference particles

International Nuclear Information System (INIS)

Stefaniak, Elzbieta A.; Pointurier, Fabien; Marie, Olivier; Truyens, Jan; Aregbe, Yetunde

2014-01-01

Information about the molecular composition of airborne uranium-bearing particles may be useful as an additional tool for nuclear safeguards. In order to combine the detection of micrometer-sized particles with the analysis of their molecular forms, we used a hybrid system enabling Raman microanalysis in high vacuum inside a SEM chamber (SEM-SCA system). The first step involved an automatic scan of a sample to detect and save coordinates of uranium particles, along with X-ray microanalysis. In the second phase, the detected particles were relocated in a white light image and subjected to Raman microanalysis. The consecutive measurements by the two beams showed exceptional fragility of uranium particles, leading to their ultimate damage and change of uranium oxidation state. We used uranium reference particles prepared by hydrolysis of uranium hexafluoride to test the reliability of the Raman measurements inside the high vacuum. The results achieved by the hybrid system were verified by using a standalone Raman micro spectrometer. When deposited on exceptionally smooth substrates, uranyl fluoride particles smaller than 1000 nm could successfully be analyzed with the SEM-SCA system. (authors)

Uranium exploration in India: present status and future strategies

International Nuclear Information System (INIS)

Maithani, P.B.

2011-01-01

Exploration for Uranium in India dates back to 1949, where surveys to locate atomic minerals were initiated in the well established Copper Thrust Belt (CTB) of Singhbhum, in the present day Jharkhand state. Based on the limited understanding on uranium geology, the thrust zones of Singhbhum which were popularly known for hosting Copper mineralization were targeted presuming sympathetic relation between Copper and Uranium. Exploration for uranium over the past six decades has resulted in identifying eleven major uranium deposits distributed in varied geological environs all over the country. Apart from conventional uranium mineralization, non-conventional resources like phosphorite, black shale etc. have immense potential. Even though their uranium grades will be of lower order, their uranium content will be huge due to their extensive size. In addition to intensifying uranium exploration in potential geological domains, AMD also plans to tap the non-conventional resources which will add substantially to the resource base

Uranium in Nova Scotia: a background summary for the uranium inquiry, Nova Scotia

International Nuclear Information System (INIS)

1982-01-01

Since the mid 1970's Nova Scotia has experienced increased exploration for a number of commodities including uranium. The exploration activity for uranium has resulted in discovery of significant occurrences of the element. It became obvious to the Government of Nova Scotia that a segment of the population of the Province is concerned about the potential hazards associated with the exploration, mining and milling stages of the uranium industry. Public concern has resulted in the appointment of a Commissioner under the Public Inquiries Act of Nova Scotia to inquire and make recommendations to the Governor-in-Council on all aspects of exploration, development, mining, processing, storage, waste management and transportation of uranium in any form. The regulation of mineral exploration and mining activities is carried out by the Nova Scotia Department of Mines and Energy through the Mineral Resources Act of the Province of Nova Scotia. The regulation of the special radioactive aspects involved in the mining and processing of uranium ore is the responsibility of the federal Atomic Energy Control Board. The purposes of this report is to: outline the history of uranium exploration in Nova Scotia; summarize the results of geological surveys by provincial and federal government agencies, universities and exploration companies which document the natural levels of radioactivity in the Province; briefly outline the physical and chemical characteristics of uranium and thorium which make these elements unique and a potential environmental and health concern; outline chronologically the steps taken by the Nova Scotia Department of Mines and Energy to monitor and regulate uranium exploration activities; classify the types of uranium deposits known to occur in Nova Scotia and describe their main geological features; outline the role of the Nova Scotia Department of Mines and Energy in the regulation of mining activities in the Province. The report is written for the interested

Fluvial sedimentology of a major uranium-bearing sandstone - A study of the Westwater Canyon member of the Morrison Formation, San Juan Basin, New Mexico

International Nuclear Information System (INIS)

Turner-Peterson, C.E.

1986-01-01

The Westwater Canyon Member of the Morrison Formation, the main ore-bearing sandstone in the San Juan basin, consists of a sequence of vertically stacked braided stream deposits. Three fluvial units within the sequence can be delineated in the basin. Volcanic pebbles are abundant in the middle fluvial unit, in a zone that forms a crude time line. A pronounced thickening of sandstone in the Westwater Canyon Member north of Gallup, once believed to be the apex of a large alluvial fan, is now thought to merely reflect a greater accumulation of sediment in response to downwarping of the basin in that area. Provenance studies suggest that highlands that contributed detritus to Westwater Canyon streams were located several hundred kilometers to the west and southwest of the San Juan basin, and thus fan apices would also have been several hundred kilometers upstream. The fluvial units recognized in the basin may well be coalesced distal fan deposits, but are probably best interpreted as vertically stacked braided steam sequences. Facies changes in fine-grained interbeds of the Westwater Canyon probably have greater significance in terms of localizing ore than any special attribute of the fluvial sandstones themselves. Uranium ore generally occurs in sandstones that are interbedded with greenish-gray lacustrine mudstones. Pore waters that were expelled from these mudstones are thought to have been the source of the pore-filling organic matter (humate) associated with primary uranium ore in nearby sandstones

Characteristics of isotope geology of sandstone-type uranium deposit in Turpan-Hami Basin

International Nuclear Information System (INIS)

Liu Hanbin; Xia Yuliang; Lin Jinrong; Fan Guang

2003-01-01

This paper expounds the isotope characteristics of in-situ leachable sandstone-type uranium deposit of Shihongtan in the southwestern part of Turpan-Hami basin. The results suggest that uranium mineralization age of 48 ± 2 Ma and 28 ± 4 Ma are obtained. The ages of the porphyritic granite and gneissic granite from the southwestern area are 422 ± 5 Ma and 268 ± 23 Ma. The U-Pb age of clastic zircons from ore-bearing sandstone is 283 ± 67 Ma, which is corresponding to the age of gneissic granite of the provenance area indicating the material source of uraniferous sandstone.Based. The sources are uraniferous sandstone accumulated during the deposition and the uranium leached from provenance area rocks by weathering. (authors)

Preliminary discussion on prospecting potential for sandstone-type uranium deposits in meso-cenozoic basins, northern Ordos

International Nuclear Information System (INIS)

Di Yongqiang

2002-01-01

Characteristics of the regional stratigraphy, tectonic movement, geologic evolution and hydrogeology are briefly introduced. Using the metallogenic theory and prospecting criteria for interlayer oxidation zone sandstone-type uranium deposits, the author analyses the prospecting potential and main prospecting targets in the region, and proposes suggestions for further prospecting work as well

Preliminary study of the uranium favorability of Malheur County, Oregon

International Nuclear Information System (INIS)

Erikson, E.H.

1977-11-01

A reconnaissance study of middle and upper Tertiary volcaniclastic sedimentary and silicic volcanic rocks in Malheur County, Oregon, indicates that, based upon the data available: (1) it is unlikely that sandstone-type uranium deposits exist in sedimentary rocks of north-central Malheur County; and (2) favorable uranium environments are more likely to exist in and adjacent to uraniferous silicic eruptive centers and plugs. Some rhyolites in the northern part of the county contain marginally anomalous uranium abundances (6 to 8 +- 2 ppM U 3 O 8 ), compared with similar rocks in southeastern Oregon. Available uranium from these rocks, as determined by nitric-acid leaching, approaches 50 to 75 percent of the total chemical U 3 O 8 present. One Pliocene rhyolite vitrophyre sample from Duck Butte in western Malheur County contains 9 +- 2 ppM U 3 O 8 . The uranium contents of these rhyolites approach those found in silicic plugs spatially related to uranium deposits in the Lakeview district, Oregon (Erikson and Curry, 1977). It is possible that undiscovered epithermal and (or) supergene uranium deposits may exist in favorable wall rocks subjacent to uraniferous silicic eruptive centers (Duck Butte), calderas (McDermitt caldera to the south and others identified in western Owyhee County, Idaho), and silicic plugs (as in the Lakeview district). With the exception of one small uranium anomaly found in unconsolidated sands in the Grassy Mountain Formation, the sedimentary rocks observed in the study area did not possess abnormal radioactivity or exhibit evidence of uranium mobility and enrichment. Carbonaceous trash is uncommon in these rocks. Gently dipping sandstone members of the Deer Butte Formation (upper Miocene) and local channel sands in the Grassy Mountain Formation (Pliocene) may have once been the most permeable rocks in the Tertiary section; but, there is no evidence to suggest that they were conduits for uranium-bearing solutions

Prospects for increasing uranium resources in the Khiagda ore field (Russian Federation)

International Nuclear Information System (INIS)

Novgorodtcev, A.; Martynenko, V.; Gladyshev, A.

2014-01-01

The Khiagda ore field uranium deposits are located in the Republic of Buryatia, on the Amalat Plateau formed by the Neogene basalts. The position of the ore field is defined by a large tectonic structure having a north-eastern strike the Baisykhan Uplift. The slopes of the Baisykhan dividing uplift are incised by short (4 to 16 km) lateral tributaries of the Amalat and Atalanga paleorivers. The paleovalley network is filled with terrigenous-volcanogenic units of the Miocene Dzhilinda Formation (N1dz) buried under a thick cover of plateau basalts. The upheaval of the Baisykhan Uplift in the Neogene caused the penetration of the hydrodynamic flow of oxygenous uranium-bearing water into the sedimentary rock mass and formation of the subsoil/tabular oxidation zone (STOZ) on the boundary of which there formed uranium mineralisation.