Method for providing uranium with a protective copper coating

DOEpatents

Waldrop, Forrest B.; Jones, Edward

1981-01-01

The present invention is directed to a method for providing uranium metal with a protective coating of copper. Uranium metal is subjected to a conventional cleaning operation wherein oxides and other surface contaminants are removed, followed by etching and pickling operations. The copper coating is provided by first electrodepositing a thin and relatively porous flash layer of copper on the uranium in a copper cyanide bath. The resulting copper-layered article is then heated in an air or inert atmosphere to volatilize and drive off the volatile material underlying the copper flash layer. After the heating step an adherent and essentially non-porous layer of copper is electro-deposited on the flash layer of copper to provide an adherent, multi-layer copper coating which is essentially impervious to corrosion by most gases.

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

USGS Publications Warehouse

Olson, Jerry C.

1988-01-01

The Cochetopa and Marshall Pass uranium districts are in Saguache and Gunnison Counties, south-central Colorado. Geologic mapping of both districts has shown that their structural history and geologic relationships have a bearing on the distribution and origin of their uranium deposits. In both districts, the principal uranium deposits are situated at the intersection of major faults with Tertiary erosion surfaces. These surfaces were buried by early Tertiary siliceous tuffs-- a likely source of the uranium. That uranium deposits are related to such unconformities in various parts of the world has been suggested by many other authors. The purpose of this study is to understand the geology of the two districts and to define a genetic model for uranium deposits that may be useful in the discovery and evaluation of uranium deposits in these and other similar geologic settings. The Cochetopa and Marshall Pass uranium districts produced nearly 1,200 metric tons of uranium oxide from 1956 to 1963. Several workings at the Los Ochos mine in the Cochetopa district, and the Pitch mine in the Marshall Pass district, accounted for about 97 percent of this production, but numerous other occurrences of uranium are known in the two districts. As a result of exploration of the Pitch deposit in the 1970's, a large open-pit mining operation began in 1978. Proterozoic rocks in both districts comprise metavolcanic, metasedimentary, and igneous units. Granitic rocks, predominantly quartz monzonitic in composition, occupy large areas. In the northwestern part of the Cochetopa district, metavolcanic and related metasedimentary rocks are of low grade (lower amphibolite facies). In the Marshall Pass district, layered metamorphic rocks are predominantly metasedimentary and are of higher (sillimanite subfacies) grade than the Cochetopa rocks. Paleozoic sedimentary rocks in the Marshall Pass district range from Late Cambrian to Pennsylvanian in age and are 700 m thick. The Paleozoic rocks include, from oldest to youngest, the Sawatch Quartzite, Manitou Dolomite, Harding Quartzite, Fremont Dolomite, Parting Formation and Dyer Dolomite of the Chaffee Group, Leadville Dolomite, and Belden Formation. In the Cochetopa district, Paleozoic rocks are absent. Mesozoic sedimentary rocks overlie the Precambrian rocks in the Cochetopa district and comprise the Junction Creek Sandstone, Morrison Formation, Dakota Sandstone, and Mancos Shale. In the Marshall Pass district, Mesozoic rocks are absent and were presumably removed by pre-Tertiary erosion. Tertiary volcanic rocks were deposited on an irregular surface of unconformity; they blanketed both districts but have been eroded, away from much of the area. They include silicic ash flows as well as andesitic lava flows and breccias. In the Marshall Pass district, a 20to 20D-m thickness of waterlaid tuff of early Tertiary age indicates the former presence of a lake over much of the district. In the Cochetopa district, faults have a predominantly east-west trend, and the major Los Ochos fault shows displacement during Laramide time. In the Marshall Pass district, the Chester fault is a major north-trending reverse fault along which Proterozoic rocks have been thrust westward over Paleozoic and Proterozoic rocks. Displacement on the Chester fault was almost entirely of Laramide age. Both faults and old erosion surfaces or unconformities are important in the origin of uranium deposits because of their influence on the movement and localization of ore-forming solutions. In the Cochetopa district, all the known uranium occurrences crop out within 100 m of the inferred position of the unconformity surface beneath the Tertiary volcanic rocks. Much of the district was part of the drainage of an ancestral Cochetopa Creek. The principal uranium deposit, at the Los Ochos mine, is localized along the Los Ochos fault and is near the bottom of the paleovalley where the paleovalley crosses the fault. This

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

USGS Publications Warehouse

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

2017-12-18

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

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

NASA Astrophysics Data System (ADS)

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

2010-05-01

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

Uranium content and leachable fraction of fluorspars

USGS Publications Warehouse

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

2000-01-01

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

Characterization of Blistering and Delamination in Depleted Uranium Hohlraums

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

Biobaum, K. J. M.

2013-03-01

Blistering and delamination are the primary failure mechanisms during the processing of depleted uranium (DU) hohlraums. These hohlraums consist of a sputter-deposited DU layer sandwiched between two sputter-deposited layers of gold; a final thick gold layer is electrodeposited on the exterior. The hohlraum is deposited on a copper-coated aluminum mandrel; the Al and Cu are removed with chemical etching after the gold and DU layers are deposited. After the mandrel is removed, blistering and delamination are observed on the interiors of some hohlraums, particularly at the radius region. It is hypothesized that blisters are caused by pinholes in the coppermore » and gold layers; etchant leaking through these holes reaches the DU layer and causes it to oxidize, resulting in a blister. Depending on the residual stress in the deposited layers, blistering can initiate larger-scale delamination at layer interfaces. Scanning electron microscopy indicates that inhomogeneities in the machined aluminum mandrel are replicated in the sputter-deposited copper layer. Furthermore, the Cu layer exhibits columnar growth with pinholes that likely allow etchant to come in contact with the gold layer. Any inhomogeneities or pinholes in this initial gold layer then become nucleation sites for blistering. Using a focused ion beam system to etch through the gold layer and extract a cross-sectional sample for transmission electron microscopy, amorphous, intermixed layers at the gold/DU interfaces are observed. Nanometer-sized bubbles in the sputtered and electrodeposited gold layers are also present. Characterization of the morphology and composition of the deposited layers is the first step in determining modifications to processing parameters, with the goal of attaining a significant improvement in hohlraum yield.« less

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

USGS Publications Warehouse

Spirakis, C.S.

1996-01-01

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

Uranium potential of the Burro Canyon Formation in western Colorado

USGS Publications Warehouse

Craig, L.C.

1982-01-01

The Burro Canyon Formation of Early Cretaceous age overlies the Morrison Formation (Late Jurassic) and underlies the Dakota Sandstone (Late Cretaceous) over most of southeastern Utah and southwestern Colorado. It consists mainly of alternating beds of fluvial sandstone and overbank mudstone with sandstone dominating in the lower part of the formation and mudstone in the upper part. At the outcrop, the sandstones in the formation exhibit almost all the characteristics that are considered favorable for the occurrence of sandstone-type uranium deposits, but only a few small deposits have been discovered in the Colorado-Utah area. The major deficiency of the Burro Canyon in these outcrop areas is the absence of a reductant such as carbonaceous debris, humic or humate materials, or pyrite. Reductants were probably removed during a period of extensive oxidation at the time of deposition and during a subsequent erosional episode prior to deposition of the Dakota Sandstone. The formation reaches a lobate, inexactly located eastern margin that extends from near Meeker, Colorado, southward through the Piceance basin to near Aztec, New Mexico, in the northwestern part of the San Juan Basin. Along much of this distance, the formation is in the subsurface and has been penetrated by only a few drill holes. Along this eastern margin, the lobes project eastward where fluvial distributary streams built minor alluvial fans of relatively high-energy deposits out from the main axis of Burro Canyon stream deposition. The lower and distal reaches of these lobes may have survived the period of post depositional erosion and oxidation in a reduced condition because of low relief and the protection of a high water table. If so, the peripheral and distal parts of these lobes may have retained the precipitants necessary to form a uranium deposit. Two of the lobes extend into the southwest margin of the Piceance Basin and are considered the possible location of uranium deposits. Two additional lobes extend into the northwestern part of the San Juan Basin but have not been evaluated in this study.

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

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

Garland, P.A.; Thomas, J.M.; Brock, M.L.

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, andmore » (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.« less

Maps showing the distribution of uranium-deposit clusters in the Colorado Plateau uranium province

USGS Publications Warehouse

Finch, Warren I.

1991-01-01

The Colorado Palteau Uranium Province (CPUP) is defined by the distribution of uranium deposits, chiefly the sandstone-type, in upper Paleozoic and Mesozoic sedimentary rocks within the Colorado Plateau physiographic province (Granger and others, 1986).  The uranium province is bordered by widely distributed and mostly minor uranium deposits in Precambrian and Tertiary rocks and by outcrops of Tertiary extrusive and intrusive igneous rocks.  

Uniform deposition of uranium hexafluoride (UF6): Standardized mass deposits and controlled isotopic ratios using a thermal fluorination method

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

McNamara, Bruce K.; O’Hara, Matthew J.; Casella, Andrew M.

2016-07-01

Abstract: We report a convenient method for the generation of volatile uranium hexafluoride (UF6) from solid uranium oxides and other uranium compounds, followed by uniform deposition of low levels of UF6 onto sampling coupons. Under laminar flow conditions, UF6 is shown to interact with surfaces within the chamber to a highly predictable degree. We demonstrate the preparation of uranium deposits that range between ~0.01 and 470±34 ng∙cm-2. The data suggest the method can be extended to creating depositions at the sub-picogram∙cm-2 level. Additionally, the isotopic composition of the deposits can be customized by selection of the uranium source materials. Wemore » demonstrate a layering technique whereby two uranium solids, each with a different isotopic composition, are employed to form successive layers of UF6 on a surface. The result is an ultra-thin deposit of UF6 that bears an isotopic signature that is a composite of the two uranium sources. The reported deposition method has direct application to the development of unique analytical standards for nuclear safeguards and forensics.« less

Rhizofiltration using sunflower (Helianthus annuus L.) and bean (Phaseolus vulgaris L. var. vulgaris) to remediate uranium contaminated groundwater.

PubMed

Lee, Minhee; Yang, Minjune

2010-01-15

The uranium removal efficiencies of rhizofiltration in the remediation of groundwater were investigated in lab-scale experiments. Sunflower (Helianthus annuus L.) and bean (Phaseolus vulgaris L. var. vulgaris) were cultivated and an artificially uranium contaminated solution and three genuine groundwater samples were used in the experiments. More than 80% of the initial uranium in solution and genuine groundwater, respectively, was removed within 24h by using sunflower and the residual uranium concentration of the treated water was lower than 30 microg/L (USEPA drinking water limit). For bean, the uranium removal efficiency of the rhizofiltration was roughly 60-80%. The maximum uranium removal via rhizofiltration for the two plant cultivars occurred at pH 3-5 of solution and their uranium removal efficiencies exceeded 90%. The lab-scale continuous rhizofiltration clean-up system delivered over 99% uranium removal efficiency, and the results of SEM and EDS analyses indicated that most uranium accumulated in the roots of plants. The present results suggested that the uranium removal capacity of two plants evaluated in the clean-up system was about 25mg/kg of wet plant mass. Notably, the removal capacity of the root parts only was more than 500 mg/kg.

Application of remote sensor data to geologic analysis of the Bonanza test site Colorado

NASA Technical Reports Server (NTRS)

Lee, K. (Compiler)

1975-01-01

Selected samples of anomalous surface features commonly associated with the various types of uranium deposits are presented and recommendations for sensor applications are given. The features studied include: epigenetic uranium ore roll type; precambrian basal conglomerate type; vein-type uranium deposits; pipe-structure or diatreme deposits; evaporitic uranium deposits. The hydrogeology of the Mosquito Range and the San Luis Valley is also examined.

A new model for tabular-type uranium deposits

USGS Publications Warehouse

Sanford, R.F.

1992-01-01

Tabular-type uranium deposits occur as tabular, originally subhorizontal bodies entirely within reduced fluvial sandstones of Late Silurian age or younger. This paper proposes that belts of tabular-type uranium deposits formed in areas of mixed local and regional groundwater discharge shortly after deposition of the host sediments. The general characteristics of tabular-type uranium deposits indicate that their essential feature was the formation at a density-stratified ground-water interface in areas of local and regional ground-water discharge. Reconstruction of the paleohydrogeology is the key to understanding the formation of these deposits. Geologic ground-water controls that favor discharge, such as the pinch-out of major aquifers, are also favorable for uranium ore. The combination of topographic and geologic features that both cause discharge is most favorable for ore deposition. -from Author

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

USGS Publications Warehouse

Gott, Garland B.; Erickson, Ralph L.

1952-01-01

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

RELATIONSHIP OF URANIUM ORE DEPOSITS TO PETROLEUM AND GAS-BEARING STRUCTURES

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

Russell, R.T.

eposits are located on producing or breached oil and gas structures, or in the immediate vicinity of such structures. Individual deposits associated with these structures contain ore reserves which may exceed one million tons. Data derived from a study of the known deposits should be useful in evaluating the potentiality of other areas where similar structural relations and abnormal radioactivity are known to exist. Uranium deposits located in producing oil or gas fields include a deposit of more than one million tons of uranium ore on a single salt dome in Texas, and uranium deposits in the Poison Basin, Wyoming,more » which are situated over a producing naturalgas structure, having a potential of 100,000 to 200,000 tons. Important uranium mining districts are also located near producing oil fields or near structures which may have contained oil at some time in the past. The Gas Hills district to Wyoming is on the flanks of a breached anticline and within one mile of natural-gas seeps. Deposits in the Brown's Park formation near Maybell, Colorado, are witin 10 miles of producing oil wells and natural-gas seeps are known within one mile of some of the uranium mines; and at Morrison, Colorado, uranium ore is associated with tar seeps. On th Colorado Plateau, large ore bodies with total reserves of at least 30 million tons of 0.3% U/sub 3/O/sub 8/ ore in the Ambrosia Lake district near Grants, New Mexico, and produce ore associated with asphaltite.'' The uraniferous asphaltite'' ore at Temple Mountain, Utah has been known for nearly 50 years. At both Circle Cliffs and the Inter- River area in Utah, uranium ore is associated with asphaltic material on anticlinal structures. Many other deposits are on breached strucIn Wyoming, uranium deposits in Tertiary sandstone and arkose generally lack carbon trash, but are located near oil or gas structures that contain hydrocarbons and natural gases capable of precititating uranium. Also, many uranium deposits on the Colorado Plateau have insufficient plant remains present to be the fixing agent for uranium, but petroleum and/or natural gas are proposed as possible extractants. The hydrogen sulfide contaned in natural gas or dissolved in oil-field water has been a factor in the formation of some uranium deposits. Oil-type structural traps must have been effective in localizing both petroleum and uranium ore in some districts. Although petroleum may contain small amounts of uranium, it is doubtful if either oil or natural gas are important transporting agents for uranium. Careful consideration of these various factors will provide a basis upon which to evaluate more effectively many ore producing areas. (auth)« less

The Main Factors of Uranium Accumulation in the Ishim Plain Saline Lakes (Western Siberia)

NASA Astrophysics Data System (ADS)

Vladimirov, A. G.; Krivonogov, S. K.; Karpov, A. V.; Nikolaeva, I. V.; Razvorotneva, L. I.; Kolpakova, M. N.; Moroz, E. N.

2018-04-01

Hydrochemical analysis of the high-salinity lakes in the Ishim Plain (>250-300 g/L) located at the border with the Northern Kazakhstan uranium ore province is performed. The studies have shown that the main factor of concentration and redistribution of uranium in the lake basins of the Ishim Plain are the processes of intense salt deflation causing sanding of lakes and uranium depletion in the near-surface layer of the bottom deposits. The correlation between the hydroxide forms of uranium binding in the bottom lacustrine deposits of the Ishim Plain and the coffinite composition of the Semizbai deposit makes it possible to consider this province to be promising for the discovery of hydromineral uranium deposits.

Preliminary study of favorability for uranium resources in Juab County, Utah

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

Leedom, S.H.; Mitchell, T.P.

1978-02-01

The best potential for large, low-grade uranium deposits in Juab County is in the hydrothermally altered vitric tuffs of Pliocene age. The lateral extent of the altered tuffs may be determined by subsurface studies around the perimeter of the volcanic centers in the Thomas Range and the Honeycomb Hills. Because the ring-fracture zone associated with collapse of the Thomas caldera was a major control for hydrothermal uranium deposits, delineation of the northern and eastern positions of the ring-fracture zone is critical in defining favorable areas for uranium deposits. A small, medium-grade ore deposit in tuffaceous sand of Pliocene age atmore » the Yellow Chief mine in Dugway Dell is unique in origin, and the probability of discovering another deposit of this type is low. A deposit of this type may be present under alluvial cover in the northwestern Drum Mountains along the southern extension of the ring-fracture zone of the Thomas caldera. Festoonlike iron oxide structures and uranium deposition within permeable sandstone horizons indicate that the Yellow Chief deposit was formed by recent ground-water circulation. Granitic intrusive rocks in the Deep Creek Range and in Desert Mountain contain isolated epigenetic vein-type deposits. These rocks could be a source of arkosic sediments buried in adjacent valleys. The Pleistocene lacustrine sediments and playa lake brines may contain concentrations of uranium leached from uranium-rich rocks.« less

Hydrogeology of an ancient arid closed basin: implications for tabular sandstone-hosted uranium deposits

USGS Publications Warehouse

Sanford, R.F.

1990-01-01

Hydrogeologic modeling shows that tabular-type uranium deposits in the Grants uranium region of the San Juan basin, New Mexico, formed in zones of ascending and discharging regional ground-water flow. The association of either lacustrine mudstone or actively subsiding structures and uranium deposits can best be explained by the occurrence of lakes at topographic depressions where ground water having different sources and compositions is likely to converge, mix, and discharge. Ascending and discharging flow also explains the association of uranium deposits with underlying evaporites and suggests a brine interface. The simulations contradict previous suggestions that ground water moved downward in the mudflat. -Author

Descriptive models of major uranium deposits in China - Some results of the Workshop on Uranium Resource Assessment sponsored by the International Atomic Energy Agency, Vienna, Austria, in cooperation with China National Nuclear Corporation, Beijing, and the U.S. Geological Survey, Denver, Colorado, and Reston, Virginia

USGS Publications Warehouse

Finch, W.I.; Feng, S.; Zuyi, C.; McCammon, R.B.

1993-01-01

Four major types of uranium deposits occur in China: granite, volcanic, sandstone, and carbonaceous-siliceous-pelitic rock. These types are major sources of uranium in many parts of the world and account for about 95 percent of Chinese production. Descriptive models for each of these types record the diagnostic regional and local geologic features of the deposits that are important to genetic studies, exploration, and resource assessment. A fifth type of uranium deposit, metasomatite, is also modeled because of its high potential for production. These five types of uranium deposits occur irregularly in five tectonic provinces distributed from the northwest through central to southern China. ?? 1993 Oxford University Press.

Factors controlling localization of uranium deposits in the Dakota Sandstone, Gallup and Ambrosia Lake mining districts, McKinley County, New Mexico

USGS Publications Warehouse

Pierson, Charles Thomas; Green, Morris W.

1977-01-01

Geologic studies were made at all of the uranium mines and prospects in the Dakota Sandstone of Early(?) and Late Cretaceous age in the Gallup mining district, McKinley County, New Mexico. Dakota mines in the adjacent Ambrosia Lake mining district were visited briefly for comparative purposes. Mines in the eastern part of the Gallup district, and in the Ambrosia Lake district, are on the Chaco slope of the southern San Juan Basin in strata which dip gently northward toward the central part of the basin. Mines in the western part of the Gallup district are along the Gallup hogback (Nutria monocline) in strata which dip steeply westward into the Gallup sag. Geologic factors which controlled formation of the uranium deposits in the Dakota Sandstone are: (1) a source of uranium, believed to be uranium deposits of the underlying Morrison Formation of Late Jurassic age; (2) the accessibility to the Dakota of uranium-bearing solutions from the Morrison; (3) the presence in the Dakota of permeable sandstone beds overlain by impermeable carbonaceous shale beds; and (4) the occurrence within the permeable Dakota sandstone beds of carbonaceous reducing material as bedding-plane laminae, or as pockets of carbonaceous trash. Most of the Dakota uranium deposits are found in the lower part of the formation in marginal-marine distributary-channel sandstones which were deposited in the backshore environment. However, the Hogback no. 4 (Hyde) Mine (Gallup district) occurs in sandy paludal shale of the backshore environment, and another deposit, the Silver Spur (Ambrosia Lake district), is found in what is interpreted to be a massive beach or barrier-bar sandstone of the foreshore environment in the upper part of the Dakota. The sedimentary depositional environment most favorable for the accumulation of uranium is that of backshore areas lateral to main distributary channels, where levee, splay, and some distributary-channel sandstones intertongue with gray carbonaceous shales and siltstones of the well-drained swamp environment. Deposits of black carbonaceous shale which were formed in the poorly drained swamp deposits of the interfluve area are not favorable host rocks for uranium. The depositional energy levels of the various environments in which the sandstone and shale beds of the Dakota were deposited govern the relative favorability of the strata as uranium host rocks. In the report area, uranium usually occurs in carbonaceous sandstone deposited under low- to medium-energy fluvial conditions within distributary channels. A prerequisite, however, is that such sandstone be overlain by impermeable carbonaceous shale beds. Low- to medium-energy fluvial conditions result in the deposition of sandstone beds having detrital carbonaceous material distributed in laminae or in trash pockets on bedding planes. The carbonaceous laminae and trash pockets provide the necessary reductant to cause precipitation of uranium from solution. High-energy fluvial conditions result in the deposition of sandstones having little or no carbonaceous material included to provide a reductant. Very low energy swampy conditions result in carbonaceous shale deposits, which are generally barren of uranium because of their relative impermeability to migrating uranium-bearing solutions.

Measuring aerosols generated inside armoured vehicles perforated by depleted uranium ammunition.

PubMed

Parkhurst, M A

2003-01-01

In response to questions raised after the Gulf War about the health significance of exposure to depleted uranium (DU), the US Department of Defense initiated a study designed to provide an improved scientific basis for assessment of possible health effects on soldiers in vehicles struck by these munitions. As part of this study, a series of DU penetrators were fired at an Abrams tank and a Bradley fighting vehicle, and the aerosols generated by vehicle perforation were collected and characterised. A robust sampling system was designed to collect aerosols in this difficult environment and monitor continuously the sampler flow rates. The aerosol samplers selected for these tests included filter cassettes, cascade impactors, a five-stage cyclone and a moving filter. Sampler redundancy was an integral part of the sampling system to offset losses from fragment damage. Wipe surveys and deposition trays collected removable deposited particulate matter. Interior aerosols were analysed for uranium concentration and particle size distribution as a function of time. They were also analysed for uranium oxide phases, particle morphology and dissolution in vitro. These data, currently under independent peer review, will provide input for future prospective and retrospective dose and health risk assessments of inhaled or ingested DU aerosols. This paper briefly discusses the target vehicles, firing trajectories, aerosol samplers and instrumentation control systems, and the types of analyses conducted on the samples.

Bioremediation of uranium contamination with enzymatic uranium reduction

USGS Publications Warehouse

Lovley, D.R.; Phillips, E.J.P.

1992-01-01

Enzymatic uranium reduction by Desulfovibrio desulfuricans readily removed uranium from solution in a batch system or when D. desulfuricans was separated from the bulk of the uranium-containing water by a semipermeable membrane. Uranium reduction continued at concentrations as high as 24 mM. Of a variety of potentially inhibiting anions and metals evaluated, only high concentrations of copper inhibited uranium reduction. Freeze-dried cells, stored aerobically, reduced uranium as fast as fresh cells. D. desulfuricans reduced uranium in pH 4 and pH 7.4 mine drainage waters and in uraniumcontaining groundwaters from a contaminated Department of Energy site. Enzymatic uranium reduction has several potential advantages over other bioprocessing techniques for uranium removal, the most important of which are as follows: the ability to precipitate uranium that is in the form of a uranyl carbonate complex; high capacity for uranium removal per cell; the formation of a compact, relatively pure, uranium precipitate.

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

DOE PAGES

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

2016-04-10

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

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

USGS Publications Warehouse

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

1983-01-01

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

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

USGS Publications Warehouse

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

1983-01-01

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

Fate of Noble Metals during the Pyroprocessing of Spent Nuclear Fuel

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

B.R. Westphal; D. Vaden; S.X. Li

During the pyroprocessing of spent nuclear fuel by electrochemical techniques, fission products are separated as the fuel is oxidized at the anode and refined uranium is deposited at the cathode. Those fission products that are oxidized into the molten salt electrolyte are considered active metals while those that do not react are considered noble metals. The primary noble metals encountered during pyroprocessing are molybdenum, zirconium, ruthenium, rhodium, palladium, and technetium. Pyroprocessing of spent fuel to date has involved two distinctly different electrorefiner designs, in particular the anode to cathode configuration. For one electrorefiner, the anode and cathode collector are horizontallymore » displaced such that uranium is transported across the electrolyte medium. As expected, the noble metal removal from the uranium during refining is very high, typically in excess of 99%. For the other electrorefiner, the anode and cathode collector are vertically collocated to maximize uranium throughput. This arrangement results in significantly less noble metals removal from the uranium during refining, typically no better than 20%. In addition to electrorefiner design, operating parameters can also influence the retention of noble metals, albeit at the cost of uranium recovery. Experiments performed to date have shown that as much as 100% of the noble metals can be retained by the cladding hulls while affecting the uranium recovery by only 6%. However, it is likely that commercial pyroprocessing of spent fuel will require the uranium recovery to be much closer to 100%. The above mentioned design and operational issues will likely be driven by the effects of noble metal contamination on fuel fabrication and performance. These effects will be presented in terms of thermal properties (expansion, conductivity, and fusion) and radioactivity considerations. Ultimately, the incorporation of minor amounts of noble metals from pyroprocessing into fast reactor metallic fuel will be shown to be of no consequence to reactor performance.« less

National Uranium Resource Evaluation: Durango Quadrangle, Colorado

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

Theis, N.J.; Madson, M.E.; Rosenlund, G.C.

1981-06-01

The Durango Quadrangle (2/sup 0/), Colorado, was evaluated using National Uranium Resource Evaluation criteria to determine environments favorable for uranium deposits. General reconnaissance, geologic and radiometric investigations, was augmented by detailed surface examination and radiometric and geochemical studies in selected areas. Eight areas favorable for uranium deposits were delineated. Favorable geologic environments include roscoelite-type vanadium-uranium deposits in the Placerville and Barlow Creek-Hermosa Creek districts, sandstone uranium deposits along Hermosa Creek, and vein uranium deposits in the Precambrian rocks of the Needle Mountains area and in the Paleozoic rocks of the Tuckerville and Piedra River Canyon areas. The major portions ofmore » the San Juan volcanic field, the San Juan Basin, and the San Luis Basin within the quadrangle were judged unfavorable. Due to lack of information, the roscoelite belt below 1000 ft (300 m), the Eolus Granite below 0.5 mi (0.8 km), and the Lake City caldera are unevaluated. The Precambrian Y melasyenite of Ute Creek and the Animas Formation within the Southern Ute Indian Reservation are unevaluated due to lack of access.« less

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

NASA Astrophysics Data System (ADS)

Akhtar, Shamim; Yang, Xiaoyong; Pirajno, Franco

2017-09-01

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

Uranium distribution in the coastal waters and pore waters of Tampa Bay, Florida

USGS Publications Warehouse

Swarzenski, P.W.; Baskaran, M.

2006-01-01

The geochemical reactivity of uranium (238U) and dissolved organic carbon (DOC), Fe, Mn, Ba, and V was investigated in the water column, pore waters, and across a river/estuarine mixing zone in Tampa Bay, Florida. This large estuary is impacted both by diverse anthropogenic activity and by extensive U-rich phosphatic deposits. Thus, the estuarine behavior of uranium may be examined relative to such known U enrichments and anthropogenic perturbations. Dissolved (< 0.45??m) uranium exhibited both removal and enrichment processes across the Alafia River/estuarine mixing zone relative to conservative mixing. Such non-conservative U behavior may be attributed to: i) physical mixing processes within the river; ii) U carrier phase reactivity; and/or iii) fluid exchange processes across sediment/water interface. In the bay proper, U concentrations were ?????2 to 3 times greater than those reported for other estuarine systems and are likely a result of erosional inputs from the extensive, underlying U-rich phosphatic deposits. Whereas dissolved U concentrations generally did not approach seawater values (13.6??nM) along the Alafia River salinity transect, water column U concentrations exceeded 16??nM in select regions of the bay. Within the hydrogeological framework of the bay, such enriched U may also be derived from advective fluid transport processes across the sediment/water interface, such as submarine groundwater discharge (SGD) or hyporheic exchange within coastal rivers. Pore water profiles of U in Tampa Bay show both a flux into and out of bottom sediments, and average, diffusive U pore water fluxes (Jdiff) ranged from - 82.0 to 116.6??mol d- 1. It is likely that negative U fluxes imply seawater entrainment or infiltration (i.e., submarine groundwater recharge), which may contribute to the removal of water column uranium. For comparison, a bay-wide, Ra-derived submarine groundwater discharge estimate for Tampa Bay (8??L m- 2 d- 1) yielded an average, advective (JSGD) U flux of 112.9??mol d- 1. In Tampa Bay, the estuarine distribution of U indicates a strong natural, geologic control that may also be influenced by enhanced fluid transport processes across the sediment/water interface. ?? 2006 Elsevier B.V. All rights reserved.

Preparation of carbon coated Fe3O4 nanoparticles for magnetic separation of uranium

NASA Astrophysics Data System (ADS)

Zhang, Xiaofei; Wang, Jun

2018-01-01

Uranium(VI) was removed from aqueous solutions using carbon coated Fe3O4 nanoparticles (Fe3O4@C). Batch experiments were conducted to study the effects of initial pH, shaking time and temperature on uranium sorption efficiency. It was found that the maximum adsorption capacity of the Fe3O4@C toward uranium(VI) was ∼120.20 mg g-1 when the initial uranium(VI) concentration was 100 mg L-1, displaying a high efficiency for the removal of uranium(VI) ions. Kinetics of the uranium(VI) removal is found to follow pseudo-second-order rate equation. In addition, the uranium(VI)-loaded Fe3O4@C nanoparticles can be recovered easily from aqueous solution by magnetic separation and regenerated by acid treatment. Present study suggested that magnetic Fe3O4@C composite particles can be used as an effective and recyclable adsorbent for the removal of uranium(VI) from aqueous solutions.

Natural thorium resources and recovery: Options and impacts

USGS Publications Warehouse

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

2016-01-01

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

National uranium resource evaluation: Newark Quadrangle, Pennsylvania and New Jersey

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

Popper, G.H.P.; Martin, T.S.

1982-04-01

The Newark Quadrangle, Pennsylvania and New Jersey, was evaluated to a depth of 1500 m to identify geologic environments and delineate areas favorable for uranium deposits. Criteria used were those developed for the National Uranium Resource Evaluation program. Results of the investigation indicate that the Precambrian Reading Prong contains environments favorable for anatectic and allogenic uranium deposits. Two suites of rocks are favorable for anatectic-type concentrations: An alaskite-magnetite-gneiss association, and red granite and quartz monzonite. Allogenic uranium concentrations occur in rocks of the marble-skarn-serpentinite association. Environments favorable for peneconcordant sandstone-type uranium deposits occur in the upper one-third of the Catskillmore » Formation, the Mississippian-Pennsylvanian Mauch Chunk-Pottsville transition beds, and the upper half of the Triassic Stockton Formation. The Triassic Lockatong Formation contains environments favorable for carbonaceous shale-type uranium concentrations. The Ordovician Epler Formation and the Cretaceous-Tertiary strata of the Coastal Plain were not evaluated due to time restrictions and lack of outcroup. All other geologic environments are considered unfavorable for uranium deposits.« less

Uranium in the Islamic Republic of Mauritania (phase V, deliverable 81): Chapter N in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

USGS Publications Warehouse

Fernette, Gregory

2015-01-01

Uranium occurrences are also reported in the Tasiast-Tijirit Terrane of the Archean Rgueïbat Shield, the Mauritanide Belt, and the Coastal Basin. Geologic environments permissive for eight types of uranium deposits are recognized in Mauritania. These deposit types include: calcrete, granite-hosted vein/shear, alkaline intrusive, unconformity-associated, quartz pebble conglomerate, phosphate, sandstone, and red bed-type uranium deposits.

Removal of uranium (VI) from aqueous systems by nanoscale zero-valent iron particles suspended in carboxy-methyl cellulose

NASA Astrophysics Data System (ADS)

Popescu (Hoştuc), Ioana-Carmen; Filip, Petru; Humelnicu, Doina; Humelnicu, Ionel; Scott, Thomas Bligh; Crane, Richard Andrew

2013-11-01

Carboxy-methyl-cellulose (CMC), a common "delivery vehicle" for the subsurface deployment of iron nanoparticles (INP) has been tested in the current work for the removal of aqueous uranium from synthetic water samples. A comparison of the removal of aqueous uranium from solutions using carboxy-methyl-cellulose with and without iron nanoparticles (CMC-INP and CMC, respectively) was tested over a 48 h reaction period. Analysis of liquid samples using spectrophotometry determined a maximum sorption capacity of uranium, Qmax, of 185.18 mg/g and 322.58 mg/g for CMC and CMC-INP respectively, providing strong evidence of an independent aqueous uranium removal ability exhibited by CMC. The results point out that CMC provides an additional capacity for aqueous uranium removal. Further tests are required to determine whether similar behaviour will be observed for other aqueous contaminant species and if the presence of CMC within a INP slurry inhibits or aids the reactivity, reductive capacity and affinity of INP for aqueous contaminant removal.

Regularities of spatial association of major endogenous uranium deposits and kimberlitic dykes in the uranium ore regions of the Ukrainian Shield

NASA Astrophysics Data System (ADS)

Kalashnyk, Anna

2015-04-01

During exploration works we discovered the spatial association and proximity time formation of kimberlite dykes (ages are 1,815 and 1,900 Ga for phlogopite) and major industrial uranium deposits in carbonate-sodium metasomatites (age of the main uranium ore of an albititic formation is 1,85-1,70 Ga according to U-Pb method) in Kirovogradsky, Krivorozhsky and Alekseevsko-Lysogorskiy uranium ore regions of the Ukrainian Shield (UkrSh) [1]. In kimberlites of Kirovogradsky ore region uranium content reaches 18-20 g/t. Carbon dioxide is a major component in the formation of hydrothermal uranium deposits and the formation of the sodium in the process of generating the spectrum of alkaline ultrabasic magmas in the range from picritic to kimberlite and this is the connection between these disparate geochemical processes. For industrial uranium deposits in carbonate-sodium metasomatitics of the Kirovogradsky and Krivorozhsky uranium ore regions are characteristic of uranyl carbonate introduction of uranium, which causes correlation between CO2 content and U in range of "poor - ordinary - rich" uranium ore. In productive areas of uranium-ore fields of the Kirovogradsky ore region for phlogopite-carbonate veinlets of uranium ore albitites deep δ13C values (from -7.9 to -6.9o/oo) are characteristic. Isotope-geochemical investigation of albitites from Novokonstantynovskoe, Dokuchaevskoe, Partyzanskoe uranium deposits allowed obtaining direct evidence of the involvement of mantle material during formation of uranium albitites in Kirovogradsky ore region [2]. Petrological characteristics of kimberlites from uranium ore regions of the UkrSh (presence of nodules of dunite and harzburgite garnet in kimberlites, diamonds of peridotite paragenesis, chemical composition of indicator minerals of kimberlite, in particular Gruzskoy areas pyropes (Cr2O3 = 6,1-7,1%, MgO = 19,33-20,01%, CaO = 4,14-4,38 %, the content of knorringite component of most grains > 50mol%), chromites (Cr2O3 = 45,32-62,17%, MgO = 7,3-12,5%) allow us to estimate the depth of generation of kimberlite magmas more than 170-200 km. Ilmenites show two groups according to MgO, Cr2O3 and TiO2 content. Reconstructions of the mantle sections show also two intervals of pressures divided at 4.5 GPa, the upper part is highly metasomatized This high degree metasomatism is determined for almost all mantle columns. It is suggested that large-scale of uranium-bearing mantle fluids may be associated with the ancient degasation during the subduction which is highly enriched in U component . Analysis of the reasons for the marked association kimberlitic dykes and major industrial uranium deposits in carbonate-sodium metasomatic in the UkrSh led to the conclusion that hydrothermal uranium deposits are confined to the supply mantle fluid systems of mantle fault zones exercising brings sodium carbonate solutions enriched uranium from mantle sources. References: 1. Kalashnik A.A. New prognostic-evaluation criteria in technology prognosis of forming industrial endogenous uranium deposits of the Ukrainian Shield, 2014. Scientific proceedings of UkrSGRI, № 2, p. 27-54 (in Russian) 2. Stepanjuk L.M., Bondarenko S.V., Somka V.O. and other, 2012. Source of uranium and uranium-bearing sodium albitites for example of Dokuchaievskogo field of the Ingulsky megablock of the UkrSh: Abstracts of scientific conference "Theoretical issues and research practice metasomatic rocks and ores" (Kyiv, 14-16 March 2012), IGMOF, p.78-80. (in Ukrainian)

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

NASA Astrophysics Data System (ADS)

Howari, Fares; Goodell, Philip; Salman, Abdulaty

2016-02-01

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

Genetic and grade and tonnage models for sandstone-hosted roll-type uranium deposits, Texas Coastal Plain, USA

USGS Publications Warehouse

Hall, Susan M.; Mihalasky, Mark J.; Tureck, Kathleen; Hammarstrom, Jane M.; Hannon, Mark

2017-01-01

The coincidence of a number of geologic and climatic factors combined to create conditions favorable for the development of mineable concentrations of uranium hosted by Eocene through Pliocene sandstones in the Texas Coastal Plain. Here 254 uranium occurrences, including 169 deposits, 73 prospects, 6 showings and 4 anomalies, have been identified. About 80 million pounds of U3O8 have been produced and about 60 million pounds of identified producible U3O8 remain in place. The development of economic roll-type uranium deposits requires a source, large-scale transport of uranium in groundwater, and deposition in reducing zones within a sedimentary sequence. The weight of the evidence supports a source from thick sequences of volcanic ash and volcaniclastic sediment derived mostly from the Trans-Pecos volcanic field and Sierra Madre Occidental that lie west of the region. The thickest accumulations of source material were deposited and preserved south and west of the San Marcos arch in the Catahoula Formation. By the early Oligocene, a formerly uniformly subtropical climate along the Gulf Coast transitioned to a zoned climate in which the southwestern portion of Texas Coastal Plain was dry, and the eastern portion humid. The more arid climate in the southwestern area supported weathering of volcanic ash source rocks during pedogenesis and early diagenesis, concentration of uranium in groundwater and movement through host sediments. During the middle Tertiary Era, abundant clastic sediments were deposited in thick sequences by bed-load dominated fluvial systems in long-lived channel complexes that provided transmissive conduits favoring transport of uranium-rich groundwater. Groundwater transported uranium through permeable sandstones that were hydrologically connected with source rocks, commonly across formation boundaries driven by isostatic loading and eustatic sea level changes. Uranium roll fronts formed as a result of the interaction of uranium-rich groundwater with either (1) organic-rich debris adjacent to large long-lived fluvial channels and barrier–bar sequences or (2) extrinsic reductants entrained in formation water or discrete gas that migrated into host units via faults and along the flanks of salt domes and shale diapirs. The southwestern portion of the region, the Rio Grande embayment, contains all the necessary factors required for roll-type uranium deposits. However, the eastern portion of the region, the Houston embayment, is challenged by a humid environment and a lack of source rock and transmissive units, which may combine to preclude the deposition of economic deposits. A grade and tonnage model for the Texas Coastal Plain shows that the Texas deposits represent a lower tonnage subset of roll-type deposits that occur around the world, and required aggregation of production centers into deposits based on geologic interpretation for the purpose of conducting a quantitative mineral resource assessment.

Process for removing carbon from uranium

DOEpatents

Powell, George L.; Holcombe, Jr., Cressie E.

1976-01-01

Carbon contamination is removed from uranium and uranium alloys by heating in inert atmosphere to 700.degree.-1900.degree.C in effective contact with yttrium to cause carbon in the uranium to react with the yttrium. The yttrium is either in direct contact with the contaminated uranium or in indirect contact by means of an intermediate transport medium.

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

USGS Publications Warehouse

Granger, Harry Clifford; Warren, C.G.

1979-01-01

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

Different biosorption mechanisms of Uranium(VI) by live and heat-killed Saccharomyces cerevisiae under environmentally relevant conditions.

PubMed

Wang, Tieshan; Zheng, Xinyan; Wang, Xiaoyu; Lu, Xia; Shen, Yanghao

2017-02-01

Uranium adsorption mechanisms of live and heat-killed Saccharomyces cerevisiae in different pH values and biomass concentrations were studied under environmentally relevant conditions. Compared with live cells, the adsorption capacity of heat-killed cells is almost one order of magnitude higher in low biomass concentration and highly acidic pH conditions. To explore the mesoscopic surface interactions between uranium and cells, the characteristic of uranium deposition was investigated by SEM-EDX, XPS and FTIR. Biosorption process of live cells was considered to be metabolism-dependent. Under stimulation by uranyl ions, live cells could gradually release phosphorus and reduce uranium from U(VI) to U(IV) to alleviate uranium toxicity. The uranyl-phosphate complexes were formed in scale-like shapes on cell surface. The metabolic detoxification mechanisms such as reduction and "self-protection" are of significance to the migration of radionuclides. In the metabolism-independent biosorption process of heat-killed cells: the cells cytomembrane was damaged by autoclaving which led to the free diffusion of phosphorous from intracellular, and the rough surface and nano-holes indicated that the dead cells provided larger contact area to precipitate U(VI) as spherical nano-particles. The high biosorption capacity of heat-killed cells makes it become a suitable biological adsorbent for uranium removal. Copyright © 2016 Elsevier Ltd. All rights reserved.

Results of core drilling for uranium-bearing lignites in the Bar H area, Slim Buttes, Harding County, South Dakota

USGS Publications Warehouse

Zeller, Howard D.

1953-01-01

Core drilling in the Car H area, Slim Buttes, Harding County, South Dakota, under a contract with the B. H. Mott Drilling Co., Huntington, West Virginia, was resumed June 12, 1952 after a 6-month recess during the winter and was completed July 18, 1952. The drilling was undertaken to obtain information on the distribution and extent of the uranium-bearing lignite beds along the southeast edge of the Bar H area. Eight holes totalling 885 feet were drilled and 52 feet of lignite core submitted for study and analysis. The report includes detailed lithographic descriptions of the lignite cores, Bureau of Mines coal analyses, and the results of 100 chemical analyses for uranium. The drilling showed that the thicker, more persistent lignite beds exposed in the northern part of the Bar H area were removed by erosion prior to the deposition of the overlaying White River formation in the south-eastern part of the area. The beds penetrated by drilling were not of sufficient thickness or uranium content to add to the previously known reserves.

Uranium in the Wyoming Landscape Conservation Initiative study area, southwestern Wyoming

USGS Publications Warehouse

Wilson, Anna B.

2015-10-20

In the WLCI study area, all uranium areas except Poison Basin and Ketchum Buttes contain roll-front deposits in Eocene (56–34 Ma) sedimentary rocks. Tabular sandstone-hosted uranium deposits are also recognized within the study area.

Uranium (U)-Tolerant Bacterial Diversity from U Ore Deposit of Domiasiat in North-East India and Its Prospective Utilisation in Bioremediation

PubMed Central

Kumar, Rakshak; Nongkhlaw, Macmillan; Acharya, Celin; Joshi, Santa Ram

2013-01-01

Uranium (U)-tolerant aerobic chemo-heterotrophic bacteria were isolated from the sub-surface soils of U-rich deposits in Domiasiat, North East India. The bacterial community explored at molecular level by amplified ribosomal DNA restriction analysis (ARDRA) resulted in 51 distinct phylotypes. Bacterial community assemblages at the U mining site with the concentration of U ranging from 20 to 100 ppm, were found to be most diverse. Representative bacteria analysed by 16S rRNA gene sequencing were affiliated to Firmicutes (51%), Gammaproteobacteria (26%), Actinobacteria (11%), Bacteroidetes (10%) and Betaproteobacteria (2%). Representative strains removed more than 90% and 53% of U from 100 μM and 2 mM uranyl nitrate solutions, respectively, at pH 3.5 within 10 min of exposure and the activity was retained until 24 h. Overall, 76% of characterized isolates possessed phosphatase enzyme and 53% had PIB-type ATPase genes. This study generated baseline information on the diverse indigenous U-tolerant bacteria which could serve as an indicator to estimate the environmental impact expected to be caused by mining in the future. Also, these natural isolates efficient in uranium binding and harbouring phosphatase enzyme and metal-transporting genes could possibly play a vital role in the bioremediation of metal-/radionuclide-contaminated environments. PMID:23080407

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

USGS Publications Warehouse

Fishman, Neil S.; Reynolds, Richard L.

1982-01-01

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

Removal of uranium from aqueous HF solutions

DOEpatents

Pulley, Howard; Seltzer, Steven F.

1980-01-01

This invention is a simple and effective method for removing uranium from aqueous HF solutions containing trace quantities of the same. The method comprises contacting the solution with particulate calcium fluoride to form uranium-bearing particulates, permitting the particulates to settle, and separting the solution from the settled particulates. The CaF.sub.2 is selected to have a nitrogen surface area in a selected range and is employed in an amount providing a calcium fluoride/uranium weight ratio in a selected range. As applied to dilute HF solutions containing 120 ppm uranium, the method removes at least 92% of the uranium, without introducing contaminants to the product solution.

The Gas Hills uranium district and some probable controls for ore deposition

USGS Publications Warehouse

Zeller, Howard Davis

1957-01-01

Uranium deposits occur in the upper coarse-grained facies of the Wind River formation of Eocene age in the Gas Hills district of the southern part of the Wind River Basin. Some of the principal deposits lie below the water table in the unoxidized zone and consist of uraninite and coffinite occurring as interstitial fillings in irregular blanket-like bodies. In the near-surface deposits that lie above the water table, the common yellow uranium minerals consist of uranium phosphates, silicates, and hydrous oxides. The black unoxidized uraninite -coffinite ores show enrichment of molybdenum, arsenic, and selenium when compared to the barren sandstone. Probable geologic controls for ore deposits include: 1) permeable sediments that allowed passage of ore-bearing solutions; 2) numerous faults that acted as impermeable barriers impounding the ore -bearing solutions; 3) locally abundant pyrite, carbonaceous material, and natuial gas containing hydrogen sulfide that might provide a favorable environment for precipitation of uranium. Field and laboratory evidence indicate that the uranium deposits in the Gas Hills district are very young and related to the post-Miocene to Pleistocene regional tilting to the south associated with the collapse of the Granite Mountains fault block. This may have stopped or reversed ground water movement from a northward (basinward) direction and alkaline ground water rich in carbonate could have carried the uranium into the favorable environment that induced precipitation.

The Permo-Triassic uranium deposits of Gondwanaland

NASA Astrophysics Data System (ADS)

le Roux, J. P.; Toens, P. D.

The world's uranium provinces are time bound and occur in five distinct periods ranging from the Proterozoic to the Recent. One of these periods embraces the time of Gondwana sedimentation and probably is related to the proliferation of land plants from the Devonian on-ward. Decaying vegetal matter produced reducing conditions that enhanced uranium precipitation. The association of uranium with molassic basins adjacent to uplifted granitic and volcanic arcs suggests that lithospheric plate subduction, leading to anatexis of basement rocks and andesitic volcanism, created favorable conditions for uranium mineralization. Uranium occurrences of Gondwana age are of four main types: sandstone-hosted, coal-hosted, pelite-hosted, and vein-type deposits. Sandstone-hosted deposits commonly occur in fluviodeltaic sediments and are related to the presence of organic matter. These deposits commonly are enriched in molybdenum and other base metal sulfides and have been found in South Africa, Zimbabwe, Zambia, Angola, Niger, Madagascar, India, Australia, Argentina, and Brazil. Coalhosted deposits contain large reserves of uranium but are of low grade. In Africa they are mostly within the Permian Ecca Group and its lateral equivalents, as in the Springbok Flats, Limpopo, Botswana, and Tanzania basins. Uraniferous black shales are present in the Gabon and Amazon basins but grades are low. Vein-type uranium is found in Argentina, where it occurs in clustered veins crosscutting sedimentary rocks and quartz porphyries.

Reconnaissance for uraniferous rocks in northwestern Colorado, southwestern Wyoming, and northeastern Utah

USGS Publications Warehouse

Beroni, E.P.; McKeown, F.A.

1952-01-01

Previous discoveries and studies of radioactive lignites of Tertiary age in North Dakota, South Dakota, Montana, and Wyoming led the Geological Survey in 1950 to do reconnaissance in the Green River and Uinta Basin of Wyoming and Utah, where similar lignites were believed to be present. Because of the common association of uranium with copper deposits and the presence of such deposits in the Uinta Basin, several areas containing copper-uranium minerals were also examined. No deposits commercially exploitable under present conditions were found. Samples of coal from the Bear River formation at Sage, Wyo., assayed 0.004 to 0.013 percent uranium in the ash; in the old Uteland copper mine in Uinta County, Utah, 0.007 to 0.017 percent uranium; in a freshwater limestone, Duchesne County, Utah, as much as 0.019 percent uranium; and in the Mesaverde formation at the Snow and Bonniebell claims near Jensen, Uintah County, Utah, 0.003 to 0.090 percent uranium. Maps were made and samples were taken at the Skull Creek carnotite deposits in Moffat County, Colo. (0.006 to 0.16 percent uranium); at the Fair-U claims in Routt County, Colo. (0.002 to 0.040 percent uranium); and at the Lucky Strike claims near Kremmling in Grand County, Colo. (0.006 to 0.018 percent uranium).

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

USGS Publications Warehouse

Finch, Warren Irvin

1996-01-01

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

Development of practical decontamination process for the removal of uranium from gravel.

PubMed

Kim, Ilgook; Kim, Gye-Nam; Kim, Seung-Soo; Choi, Jong-Won

2018-01-01

In this study, a practical decontamination process was developed to remove uranium from gravel using a soil washing method. The effects of critical parameters including particle size, H 2 SO 4 concentration, temperature, and reaction time on uranium removal were evaluated. The optimal condition for two-stage washing of gravel was found to be particle size of 1-2 mm, 1.0 M H 2 SO 4 , temperature of 60°C, and reaction time of 3 h, which satisfied the required uranium concentration for self-disposal. Furthermore, most of the extracted uranium was removed from the waste solution by precipitation, implying that the treated solution can be reused as washing solution. These results clearly demonstrated that our proposed process can be indeed a practical technique to decontaminate uranium-polluted gravel.

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

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

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

Geology and recognition criteria for veinlike uranium deposits of the lower to middle Proterozoic unconformity and strata-related types. Final report

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

Dahlkamp, F.J.; Adams, S.S.

1981-01-01

The discovery of the Rabbit Lake deposit, Saskatchewan, in 1968 and the East Alligator Rivers district, Northern Territory, Australia, in 1970 established the Lower-Middle Proterozoic veinlike-type deposits as one of the major types of uranium deposits. The term veinlike is used in order to distinguish it from the classical magmatic-hydrothermal vein or veintype deposits. The veinlike deposits account for between a quarter and a third of the Western World's proven uranium reserves. Lower-Middle Proterozoic veinlike deposits, as discussed in this report include several subtypes of deposits, which have some significantly different geologic characteristics. These various subtypes appear to have formedmore » from various combinations of geologic processes ranging from synsedimentary uranium precipitation through some combination of diagenesis, metamorphism, metasomatism, weathering, and deep burial diagenesis. Some of the deposit subtypes are based on only one or two incompletely described examples; hence, even the classification presented in this report may be expected to change. Geologic characteristics of the deposits differ significantly between most districts and in some cases even between deposits within districts. Emphasis in this report is placed on deposit descriptions and the interpretations of the observers.« less

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

USGS Publications Warehouse

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

1952-01-01

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

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

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

Thomas, J.M.; Garland, P.A.; White, M.B.

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,more » quadrangle name, geoformational feature, and keyword.« less

The importance of colloids and mires for the transport of uranium isotopes through the Kalix River watershed and Baltic Sea

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

Porcelli, D.; Wasserburg, G.J.; Andersson, P.S.

The importance of colloids and organic deposits for the transport of uranium isotopes from continental source regions and through the estuarine environment was investigated in the mire-rich Kalix River drainage basin in northern Sweden and the Baltic Sea. Ultrafiltration techniques were used to separate uranium and other elements associated with colloids > 10 kD and >3 kD from {open_quotes}solute{close_quotes} uranium and provided consistent results and high recovery rates for uranium as well as for other elements from large volume samples. Uranium concentrations in 0.45 {mu}m-filtered Kalix River water samples increased by a factor of 3 from near the headwaters inmore » the Caledonides to the river mouth while major cation concentrations were relatively constant. {sup 234}U {sup 238}U ratios were high ({delta}{sup 234}U = 770-1500) throughout the basin, without showing any simple pattern, and required a supply of {sup 234}U-rich water. Throughout the Kalix River, a large fraction (30-90%) of the uranium is carried by >10 kD colloids, which is compatible with uranium complexation with humic acids. No isotopic differences were found between colloid-associated and solute uranium. Within the Baltic Sea, about half of the uranium is removed at low salinities. The proportion that is lost is equivalent to that of river-derived colloid-bound uranium, suggesting that while solute uranium behaves conservatively during estuarine mixing, colloid-bound uranium is lost due to rapid flocculation of colloidal material. The association of uranium with colloids therefore may be an important parameter in determining uranium estuarine behavior. Mire peats in the Kalix River highly concentrate uranium and are potentially a significant source of recoil {sup 234}U to the mirewaters and river waters. However, mirewater data clearly demonstrate that only small {sup 234}U/{sup 238}U shifts are generated relative to inflowing groundwater. 63 refs., 8 figs., 3 tabs.« less

Organic matter diagenesis as the key to a unifying theory for the genesis of tabular uranium-vanadium deposits in the Morrison Formation, Colorado Plateau

USGS Publications Warehouse

Hansley, P.L.; Spirakis, C.S.

1992-01-01

Interstitial, epigenetic amorphous organic matter is intimately associated with uranium in the Grants uranium region and is considered essential to genetic models for these deposits. In contrast, uranium minerals are intimately associated with authigenic vanadium chlorite and vanadium oxides in amorphous organic matter-poor ores of the Slick Rock and Henry Mountains mining districts and therefore, in some genetic models amorphous organic matter is not considered crucial to the formation of these deposits. Differences in organic matter content can be explained by recognizing that amorphous organic matter-poor deposits have been subjected to more advanced stages of diagenesis than amorphous organic matter-rich deposits. Evidence that amorphous organic matter was involved in the genesis of organic matter-poor, as well as organic matter-rich, deposits is described. -from Authors

Search for uranium in western United States

USGS Publications Warehouse

McKelvey, Vincent Ellis

1953-01-01

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

Yellow Canary uranium deposits, Daggett County, Utah

USGS Publications Warehouse

Wilmarth, Verl Richard

1953-01-01

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

Statistical sampling of the distribution of uranium deposits using geologic/geographic clusters

USGS Publications Warehouse

Finch, W.I.; Grundy, W.D.; Pierson, C.T.

1992-01-01

The concept of geologic/geographic clusters was developed particularly to study grade and tonnage models for sandstone-type uranium deposits. A cluster is a grouping of mined as well as unmined uranium occurrences within an arbitrary area about 8 km across. A cluster is a statistical sample that will reflect accurately the distribution of uranium in large regions relative to various geologic and geographic features. The example of the Colorado Plateau Uranium Province reveals that only 3 percent of the total number of clusters is in the largest tonnage-size category, greater than 10,000 short tons U3O8, and that 80 percent of the clusters are hosted by Triassic and Jurassic rocks. The distributions of grade and tonnage for clusters in the Powder River Basin show a wide variation; the grade distribution is highly variable, reflecting a difference between roll-front deposits and concretionary deposits, and the Basin contains about half the number in the greater-than-10,000 tonnage-size class as does the Colorado Plateau, even though it is much smaller. The grade and tonnage models should prove useful in finding the richest and largest uranium deposits. ?? 1992 Oxford University Press.

PROCESS OF RECOVERING URANIUM

DOEpatents

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.

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

USGS Publications Warehouse

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

1992-01-01

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

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

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

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,more » 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.« less

Resource potential for commodities in addition to Uranium in sandstone-hosted deposits: Chapter 13

USGS Publications Warehouse

Breit, George N.

2016-01-01

Sandstone-hosted deposits mined primarily for their uranium content also have been a source of vanadium and modest amounts of copper. Processing of these ores has also recovered small amounts of molybdenum, rhenium, rare earth elements, scandium, and selenium. These deposits share a generally common origin, but variations in the source of metals, composition of ore-forming solutions, and geologic history result in complex variability in deposit composition. This heterogeneity is evident regionally within the same host rock, as well as within districts. Future recovery of elements associated with uranium in these deposits will be strongly dependent on mining and ore-processing methods.

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

USGS Publications Warehouse

Nash, J. Thomas; Lehrman, Norman J.

1975-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2009-12-01

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

Preliminary study of uranium favorability of the Boulder batholith, Montana

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

Castor, S.B.; Robins, J.W.

1978-01-01

The Boulder batholith of southwestern Montana is a composite Late Cretaceous intrusive mass, mostly composed of quartz monzonite and granodiorite. This study was not restricted to the plutonic rocks; it also includes younger rocks that overlie the batholith, and older rocks that it intrudes. The Boulder batholith area has good overall potential for economic uranium deposits, because its geology is similar to that of areas that contain economic deposits elsewhere in the world, and because at least 35 uranium occurrences of several different types are present. Potential is greatest for the occurrence of small uranium deposits in chalcedony veins andmore » base-metal sulfide veins. Three areas may be favorable for large, low-grade deposits consisting of a number of closely spaced chalcedony veins and enriched wall rock; the Mooney claims, the Boulder area, and the Clancy area. In addition, there is a good possibility of by-product uranium production from phosphatic black shales in the project area. The potential for uranium deposits in breccia masses that cut prebatholith rocks, in manganese-quartz veins near Butte, and in a shear zone that cuts Tertiary rhyolite near Helena cannot be determined on the basis of available information. Low-grade, disseminated, primary uranium concentrations similar to porphyry deposits proposed by Armstrong (1974) may exist in the Boulder batholith, but the primary uranium content of most batholith rocks is low. The geologic environment adjacent to the Boulder batholith is similar in places to that at the Midnite mine in Washington. Some igneous rocks in the project area contain more than 10 ppM U/sub 3/O/sub 8/, and some metasedimentary rocks near the batholith contain reductants such as sulfides and carbonaceous material.« less

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

USGS Publications Warehouse

Granger, Harry C.; Bauer, Herman L.

1950-01-01

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

Uranium deposits of Brazil

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

NONE

Brazil is a country of vast natural resources, including numerous uranium deposits. In support of the country`s nuclear power program, Brazil has developed the most active uranium industry in South America. Brazil has one operating reactor (Angra 1, a 626-MWe PWR), and two under construction. The country`s economic challenges have slowed the progress of its nuclear program. At present, the Pocos de Caldas district is the only active uranium production. In 1990, the Cercado open-pit mine produced approximately 45 metric tons (MT) U{sub 3}O{sub 8} (100 thousand pounds). Brazil`s state-owned uranium production and processing company, Uranio do Brasil, announced itmore » has decided to begin shifting its production from the high-cost and nearly depleted deposits at Pocos de Caldas, to lower-cost reserves at Lagoa Real. Production at Lagoa Real is schedules to begin by 1993. In addition to these two districts, Brazil has many other known uranium deposits, and as a whole, it is estimated that Brazil has over 275,000 MT U{sub 3}O{sub 8} (600 million pounds U{sub 3}O{sub 8}) in reserves.« less

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

Bromfield, C.S.; Grauch, R.I.; Otton, J.K.

The Richfield Quadrangle in west-central Utah was evaluated to identify areas favorable for the occurrence of uranium deposits known or likely to contain 100 tons of uranium with an average grade of not less than 100 ppM U/sub 3/O/sub 8/. Geologic reconnaissance was made of all known environments thought to be favorable for uranium deposits, and a representative selection of uranium occurrences reported in the literature was visited. Geochemical analyses from rock and limited water samples were used in the evaluation. Preliminary and incomplete aeroradiometric data and hydrogeochemical and stream-sediment analyses arrived too late in the program to be field-checkedmore » or to be adequately analyzed for this report. Two areas favorable for uranium deposits were delineated: (1) volcanogenic deposits (class 500 to 599) in association with Miocene Mount Belknap rhyolite, and acidic plutons in the Marysvale Volcanic Field in the Antelope Range and Tushar Mountains; and (2) volcanogenic (class 500 to 599) and/or magmatic hydrothermal deposits (class 330) associated with Miocene high-silica high-alkali rhyolite tuffs, flows, and hypabyssal intrusives in volcanic or subvolcanic environments in the southern Wah Wah Mountains.« less

The Nopal 1 Uranium Deposit: an Overview

NASA Astrophysics Data System (ADS)

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

2007-05-01

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

Some concepts of favorability for world-class-type uranium deposits in the northeastern United States

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

Adler, H.H.

1981-03-01

An account is given of concepts of favorability of geologic environments in the eastern United States for uranium deposits of several major types existing elsewhere in the world. The purpose is to convey some initial ideas about the interrelationships of the geology of the eastern United States and the geologic settings of certain of these world-class deposits. The study and report include consideration of uranium deposits other than those generally manifesting the geologic, geochemical and genetic characteristics associated with the conventional sandstone-type ores of the western United States.

Numerical simulation of migration behavior of uranium ore dust particles in the human respiratory tract

NASA Astrophysics Data System (ADS)

Ye, Yong-jun; Yin, An-song; Li, Zhi; Lei, Bo; Ding, De-xin

2017-04-01

There is a certain concentration of radioactive dust particles in the air of workplace of underground uranium mines. Some small diameter particles will pass through the masks and enter the respiratory tract which will cause radiation damage to the human body. In order to study deposition regularity of uranium dust in the human respiratory tract, in this paper, we firstly use the RNG turbulence model to simulate the gas flow field in the human respiratory tract Z0 ∼ Z3 level under different respiratory intensity. Then we use DPM discrete phase model to simulate the concentration, particle size distribution, deposition rate and deposition share of uranium dust particles after being filtered through the masks in the human respiratory tract Z0 to Z3 bronchus. According to the simulation results, we have got the following conclusions: the particles’ number concentration of uranium dust after being filtered through the mask in the human respiratory tract basically decreases with the increasing of particle size under different respiratory intensities on the environment of uranium mine. In addition, the intensity of respiration and the mass concentration of particles have an important influence on the deposition rate and the deposition of particles in the respiratory tract.

Uranium removal from a contaminated effluent using a combined microbial and nanoparticle system.

PubMed

Baiget, Mar; Constantí, Magda; López, M Teresa; Medina, Francesc

2013-09-25

Reduction of soluble uranium(VI) to insoluble uranium(IV) for remediating a uranium-contaminated effluent (EF-03) was examined using a biotic and abiotic integrated system. Shewanella putrefaciens was first used and reduced U(VI) in a synthetic medium but not in the EF-03 effluent sample. Subsequently the growth of autochthonous microorganisms was stimulated with lactate. When lactate was supported on active carbon 77% U(VI) was removed in 4 days. Separately, iron nanoparticles that were 50 nm in diameter reduced U(VI) by 60% in 4 hours. The efficiency of uranium(VI) removal was improved to 96% in 30 min by using a system consisting of lactate and iron nanoparticles immobilized on active carbon. Lactate also stimulated the growth of potential uranium-reducing microorganisms in the EF-03 sample. This system can be efficiently used for the bioremediation of uranium-contaminated effluents. Copyright © 2013 Elsevier B.V. All rights reserved.

SIERRA ANCHA WILDERNESS, ARIZONA.

USGS Publications Warehouse

Wrucke, Chester T.; Light, Thomas D.

1984-01-01

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

Uranium-series constraints on radionuclide transport and groundwater flow at the Nopal I uranium deposit, Sierra Pena Blanca, Mexico.

PubMed

Goldstein, Steven J; Abdel-Fattah, Amr I; Murrell, Michael T; Dobson, Patrick F; Norman, Deborah E; Amato, Ronald S; Nunn, Andrew J

2010-03-01

Uranium-series data for groundwater samples from the Nopal I uranium ore deposit were obtained to place constraints on radionuclide transport and hydrologic processes for a nuclear waste repository located in fractured, unsaturated volcanic tuff. Decreasing uranium concentrations for wells drilled in 2003 are consistent with a simple physical mixing model that indicates that groundwater velocities are low ( approximately 10 m/y). Uranium isotopic constraints, well productivities, and radon systematics also suggest limited groundwater mixing and slow flow in the saturated zone. Uranium isotopic systematics for seepage water collected in the mine adit show a spatial dependence which is consistent with longer water-rock interaction times and higher uranium dissolution inputs at the front adit where the deposit is located. Uranium-series disequilibria measurements for mostly unsaturated zone samples indicate that (230)Th/(238)U activity ratios range from 0.005 to 0.48 and (226)Ra/(238)U activity ratios range from 0.006 to 113. (239)Pu/(238)U mass ratios for the saturated zone are <2 x 10(-14), and Pu mobility in the saturated zone is >1000 times lower than the U mobility. Saturated zone mobility decreases in the order (238)U approximately (226)Ra > (230)Th approximately (239)Pu. Radium and thorium appear to have higher mobility in the unsaturated zone based on U-series data from fractures and seepage water near the deposit.

Uranium transport in the Walker River Basin, California and Nevada

USGS Publications Warehouse

Benson, L.V.; Leach, D.L.

1979-01-01

During the summer of 1976 waters from tributaries, rivers, springs and wells were sampled in the Walker River Basin. Snow and sediments from selected sites were also sampled. All samples were analyzed for uranium and other elements. The resulting data provide an understanding of the transport of uranium within a closed hydrologic basin as well as providing a basis for the design of geochemical reconnaissance studies for the Basin and Range Province of the Western United States. Spring and tributary data are useful in locating areas containing anomalous concentrations of uranium. However, agricultural practices obscure the presence of known uranium deposits and render impossible the detection of other known deposits. Uranium is extremely mobile in stream waters and does not appear to sorb or precipitate. Uranium has a long residence time (2500 years) in the open waters of Walker Lake; however, once it crosses the sediment-water interface, it is reduced to the U(IV) state and is lost from solution. Over the past two million years the amount of uranium transported to the terminal point of the Walker River system may have been on the order of 4 ?? 108 kg. This suggests that closed basin termini are sites for significant uranium accumulations and are, therefore, potential sites of uranium ore deposits. ?? 1979.

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

EPA Pesticide Factsheets

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

Application of bimodal distribution to the detection of changes in uranium concentration in drinking water collected by random daytime sampling method from a large water supply zone.

PubMed

Garboś, Sławomir; Święcicka, Dorota

2015-11-01

The random daytime (RDT) sampling method was used for the first time in the assessment of average weekly exposure to uranium through drinking water in a large water supply zone. Data set of uranium concentrations determined in 106 RDT samples collected in three runs from the water supply zone in Wroclaw (Poland), cannot be simply described by normal or log-normal distributions. Therefore, a numerical method designed for the detection and calculation of bimodal distribution was applied. The extracted two distributions containing data from the summer season of 2011 and the winter season of 2012 (nI=72) and from the summer season of 2013 (nII=34) allowed to estimate means of U concentrations in drinking water: 0.947 μg/L and 1.23 μg/L, respectively. As the removal efficiency of uranium during applied treatment process is negligible, the effect of increase in uranium concentration can be explained by higher U concentration in the surface-infiltration water used for the production of drinking water. During the summer season of 2013, heavy rains were observed in Lower Silesia region, causing floods over the territory of the entire region. Fluctuations in uranium concentrations in surface-infiltration water can be attributed to releases of uranium from specific sources - migration from phosphate fertilizers and leaching from mineral deposits. Thus, exposure to uranium through drinking water may increase during extreme rainfall events. The average chronic weekly intakes of uranium through drinking water, estimated on the basis of central values of the extracted normal distributions, accounted for 3.2% and 4.1% of tolerable weekly intake. Copyright © 2015 Elsevier Ltd. All rights reserved.

Uranium-bearing copper deposits in the Coyote district, Mora County, New Mexico

USGS Publications Warehouse

Zeller, H.D.; Baltz, Elmer Harold

1954-01-01

Uranium-bearing copper deposits occur in steeply dipping beds of the Sangre de Cristo formation of Pennsylvanian and Permian(?) age south of Coyote, Mora County, N. Mex. Mapping and sampling of these deposits indicate that they are found in lenticular carbonaceous zones in shales and arkosic sandstones. Samples from these zones contain as much as 0.067 percent uranium and average 3 percent copper. Metatyuyamunite is dissemihatedin some of the arkosic sandstone beds, and uraninite is present in some of the copper sulfide nodules occurring in the shale. These sulfide nodules are composed principally of chalcocite but include some bornite, covellite, pyrite, and malachite. Most of the samples were collected near the surface from the weathered zone. The copper and uranium were probably deposited with the sediments and concentrated into zones during compaction and lithification. Carbonaceous material in the Sangre de Cristo formation provided the environment that precipitated uranium and copper from mineral-charged connate waters forced from the clayey sediments.

National Uranium Resource Evaluation: Wells Quadrangle, Nevada, Idaho, and Utah

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

Proffitt, J.L.; Mayerson, D.L.; Parker, D.P.

1982-08-01

The Wells 2/sup 0/ Quadrangle, Nevada, Idaho, and Utah, was evaluated using National Uranium Resource Evaluation criteria to delineate areas favorable for uranium deposits. Our investigation has resulted in the delineation of areas that contain Tertiary sedimentary rocks favorable for hydroallogenic deposits in the Mountain City area (Favorable Area A) and in the Oxley Peak area north of Wells (Favorable Area B). Environments considered to be unfavorable for uranium deposits include Tertiary felsic volcanic, felsic plutonic, intermediate to mafic volcanic, Paleozoic and Mesozoic sedimentary rocks, Precambrian rocks, and most Tertiary sedimentary rocks located outside the favorable areas. Present-day basins aremore » unevaluated environments because of a paucity of adequate outcrop and subsurface data. However, the scarce data indicate that some characteristics favorable for uranium deposits are present in the Susie Creek-Tule Valley-Wild Horse basin, the Contact-Granite Range-Tijuana John stocks area, the Charleston Reservoir area, and the Wells-Marys River basin.« less

An artificially constructed Syngonium podophyllum-Aspergillus niger combinate system for removal of uranium from wastewater.

PubMed

He, Jia-dong; Wang, Yong-dong; Hu, Nan; Ding, Dexin; Sun, Jing; Deng, Qin-wen; Li, Chang-wu; Xu, Fei

2015-12-01

Aspergillus niger was inoculated to the roots of five plants, and the Syngonium podophyllum-A. niger combinate system (SPANCS) was found to be the most effective in removing uranium from hydroponic liquid with initial uranium concentration of 5 mg L(-1). Furthermore, the hydroponic experiments on the removal of uranium from the hydroponic liquids with initial uranium concentrations of 0.5, 1.0, and 3.0 mg L(-1) by the SPANCS were conducted, the inhibitory effect of A. niger on the growth of S. podophyllum in the SPANCS was studied, the accumulation characteristics of uranium by S. podophyllum in the SPANCS were analyzed, and the Fourier transform infrared (FT-IR) and extended X-ray absorption fine structure (EXAFS) spectra were measured. The results show that the removal of uranium by the SPANCS from the hydroponic liquids with initial uranium concentrations of 0.5, 1.0, and 3.0 mg L(-1) reached 98.20, 97.90, and 98.50%, respectively, after 37 days of accumulation of uranium; that the uranium concentrations in the hydroponic liquids decreased to 0.009, 0.021, and 0.045 mg L(-1), respectively, which are lower than the stipulated concentration for discharge of 0.050 mg L(-1) by the People's Republic of China; that A. niger helped to generate more groups in the root of S. podophyllum which can improve the complexing capability of S. podophyllum for uranium; and that the uranium accumulated in the root of S. podophyllum was in the form of phosphate uranyl and carboxylic uranyl.

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

May, R.T.; Strand, J.R.; Reid, B.E.

Uranium favorability of the Sangre de Cristo Formation (Pennsylvanian-Permian) in the Las Vegas basin has been evaluated. The Las Vegas basin project area, located in Colfax, Mora, and San Miguel Counties, New Mexico, comprises about 3,489 sq mi. The formation contains sedimentologic and stratigraphic characteristics that are considered favorable for uranium deposition. Field investigations consisted of section measuring, rock sampling, and ground radiometric reconnaissance. North-south and east-west cross sections of the basin were prepared from well logs and measured sections. Petrographic, chemical, and spectrographic analyses were conducted on selected samples. Stratigraphic and sedimentologic information were used to determine depositional environments.more » The most favorable potential host rocks include red to pink, coarse-grained, poorly sorted, feldspathic to arkosic lenticular sandstones with stacked sandstone thicknesses of more than 20 ft and sandstone-to-shale ratios between 1:1 and 2:1. The sandstone is interbedded with mudstone and contains carbonaceous debris and anomalous concentrations of uranium locally. Areas of maximum favorability are found in a braided-stream, alluvial-plain depositional environment in the north-central part of the Las Vegas basin. There, carbonaceous material is well preserved, probably due to rapid subsidence and burial. Furthermore, uranium favorability is highest in the lower half of the formation because carbonaceous wood and plant fragments, as well as known uranium deposits, are concentrated in this zone. Piedmont deposits in the north and east, and meander-belt, alluvial-plain deposits in the south, are not considered favorable because of the paucity of uranium deposits and a minimum of carbonaceous material.« less

Geology and recognition criteria for sandstone uranium deposits in mixed fluvial-shallow marine sedimentary sequences, South Texas. Final report

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

Adams, S.S.; Smith, R.B.

1981-01-01

Uranium deposits in the South Texas Uranium Region are classical roll-type deposits that formed at the margin of tongues of altered sandstone by the encroachment of oxidizing, uraniferous solutions into reduced aquifers containing pyrite and, in a few cases, carbonaceous plant material. Many of the uranium deposits in South Texas are dissimilar from the roll fronts of the Wyoming basins. The host sands for many of the deposits contain essentially no carbonaceous plant material, only abundant disseminated pyrite. Many of the deposits do not occur at the margin of altered (ferric oxide-bearing) sandstone tongues but rather occur entirely within reduced,more » pyurite-bearing sandstone. The abundance of pyrite within the sands probably reflects the introduction of H/sub 2/S up along faults from hydrocarbon accumulations at depth. Such introductions before ore formation prepared the sands for roll-front development, whereas post-ore introductions produced re-reduction of portions of the altered tongue, leaving the deposit suspended in reduced sandstone. Evidence from three deposits suggests that ore formation was not accompanied by the introduction of significant amounts of H/sub 2/S.« less

Removal of uranium from soil samples for ICP-OES analysis of RCRA metals

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

Wero, M.; Lederer-Cano, A.; Billy, C.

1995-12-01

Soil samples containing high levels of uranium present unique analytical problems when analyzed for toxic metals (Ag, As, Ba, Cd, Cr, Cu, Ni, Pb, Se and Tl) because of the spectral interference of uranium in the ICP-OES emission spectrometer. Methods to remove uranium from the digestates of soil samples, known to be high in uranium, have been developed that reduce the initial uranium concentration (1-3%) to less than 500 ppm. UTEVA ion exchange columns, used as an ICP-OES analytical pre-treatment, reduces uranium to acceptable levels, permitting good analytical results of the RCRA metals by ICP-OES.

Actinide removal from spent salts

DOEpatents

Hsu, Peter C.; von Holtz, Erica H.; Hipple, David L.; Summers, Leslie J.; Adamson, Martyn G.

2002-01-01

A method for removing actinide contaminants (uranium and thorium) from the spent salt of a molten salt oxidation (MSO) reactor is described. Spent salt is removed from the reactor and analyzed to determine the contaminants present and the carbonate concentration. The salt is dissolved in water, and one or more reagents are added to precipitate the thorium as thorium oxide and/or the uranium as either uranium oxide or as a diuranate salt. The precipitated materials are filtered, dried and packaged for disposal as radioactive waste. About 90% of the thorium and/or uranium present is removed by filtration. After filtration, salt solutions having a carbonate concentration >20% can be dried and returned to the reactor for re-use. Salt solutions containing a carbonate concentration <20% require further clean-up using an ion exchange column, which yields salt solutions that contain less than 0.1 ppm of thorium or uranium.

Assessment of undiscovered resources in calcrete uranium deposits, Southern High Plains region of Texas, New Mexico, and Oklahoma, 2017

USGS Publications Warehouse

Hall, Susan M.; Mihalasky, Mark J.; Van Gosen, Bradley S.

2017-11-14

The U.S. Geological Survey estimates a mean of 40 million pounds of in-place uranium oxide (U3O8) remaining as potential undiscovered resources in the Southern High Plains region of Texas, New Mexico, and Oklahoma. This estimate used a geology-based assessment method specific to calcrete uranium deposits.

Uranium removal from aqueous solution by coir pith: equilibrium and kinetic studies.

PubMed

Parab, Harshala; Joshi, Shreeram; Shenoy, Niyoti; Verma, Rakesh; Lali, Arvind; Sudersanan, M

2005-07-01

Basic aspects of uranium adsorption by coir pith have been investigated by batch equilibration. The influence of different experimental parameters such as final solution pH, adsorbent dosage, sorption time, temperature and various concentrations of uranium on uptake were evaluated. Maximum uranium adsorption was observed in the pH range 4.0-6.0. The Freundlich and Langmuir adsorption models were used for the mathematical description of the adsorption equilibrium. The equilibrium data fitted well to both the equilibrium models in the studied concentration range of uranium (200-800 mg/l) and temperatures (305-336 K). The coir pith exhibited the highest uptake capacity for uranium at 317 K, at the final solution pH value of 4.3 and at the initial uranium concentration of 800 mg/l. The kinetics of the adsorption process followed a second-order adsorption. The adsorbent used proved to be suitable for removal of uranium from aqueous solutions. 0.2 N HCl was effective in uranium desorption. The results indicated that the naturally abundant coir pith of otherwise nuisance value exhibited considerable potential for application in removal of uranium from aqueous solution.

Preliminary study of radioactive limonite localities in Colorado, Utah, and Wyoming

USGS Publications Warehouse

Lovering, T.G.; Beroni, E.P.

1956-01-01

Nine radioactive limonite localities of different types were sampled during the spring and fall of 1953 in an effort to establish criteria for differentiating limonite outcrops associated with uranium or thorium deposits from limonite outcrops not associated with such deposits. The samples were analyzed for uranium and thorium by standard chemical methods, for equivalent uranium by the radiometric method, and for a number of common metals by semiquantitative geochemical methods. Correlation coefficients were then calculated for each of the metals with respect to equivalent uranium, and to uranium where present, for all of the samples from each locality. The correlation coefficients may indicate a significant association between uranium or thorium and certain metals. Occurrences of specific that are interpreted as significant very considerably for different uranium localities but are more consistent for the thorium localities. Samples taken from radioactive outcrops in the vicinity of uranium or thorium deposits can be quickly analyzed by geochemical methods for various elements. Correlation coefficients can then be determined for the various elements with respect to uranium or thorium; if any significant correlations are obtained, the elements showing such correlation may be indicators of uranium or thorium. Soil samples of covered areas in the vicinity of the radioactive outcrop may then be analyzed for the indicator elements and any resulting anomalies used as a guide for prospecting where the depth of overburden is too great to allow the use of radiation-detecting instruments. Correlation coefficients of the associated indicator elements, used in conjunction with petrographic evidence, may also be useful in interpreting the origin and paragenesis of radioactive deposits. Changes in color of limonite stains on the outcrop may also be a useful guide to ore in some areas.

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

USGS Publications Warehouse

Wyant, Donald Gray

1954-01-01

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

Electrorefining process and apparatus for recovery of uranium and a mixture of uranium and plutonium from spent fuels

DOEpatents

Ackerman, John P.; Miller, William E.

1989-01-01

An electrorefining process and apparatus for the recovery of uranium and a mixture of uranium and plutonium from spent fuel using an electrolytic cell having a lower molten cadmium pool containing spent nuclear fuel, an intermediate electrolyte pool, an anode basket containing spent fuel, and two cathodes, the first cathode composed of either a solid alloy or molten cadmium and the second cathode composed of molten cadmium. Using this cell, additional amounts of uranium and plutonium from the anode basket are dissolved in the lower molten cadmium pool, and then substantially pure uranium is electrolytically transported and deposited on the first alloy or molten cadmium cathode. Subsequently, a mixture of uranium and plutonium is electrotransported and deposited on the second molten cadmium cathode.

Electrorefining process and apparatus for recovery of uranium and a mixture of uranium and plutonium from spent fuels

DOEpatents

Ackerman, J.P.; Miller, W.E.

1987-11-05

An electrorefining process and apparatus for the recovery of uranium and a mixture of uranium and plutonium from spent fuels is disclosed using an electrolytic cell having a lower molten cadmium pool containing spent nuclear fuel, an intermediate electrolyte pool, an anode basket containing spent fuels, two cathodes and electrical power means connected to the anode basket, cathodes and lower molten cadmium pool for providing electrical power to the cell. Using this cell, additional amounts of uranium and plutonium from the anode basket are dissolved in the lower molten cadmium pool, and then purified uranium is electrolytically transported and deposited on a first molten cadmium cathode. Subsequently, a mixture of uranium and plutonium is electrotransported and deposited on a second cathode. 3 figs.

Immobilization of uranium into magnetite from aqueous solution by electrodepositing approach.

PubMed

Lu, Bing-Qing; Li, Mi; Zhang, Xiao-Wen; Huang, Chun-Mei; Wu, Xiao-Yan; Fang, Qi

2018-02-05

Immobilization of uranium into magnetite (Fe 3 O 4 ), which was generated from metallic iron by electrochemical method, was proposed to rapidly remove uranium from aqueous solution. The effects of electrochemical parameters such as electrode materials, voltage, electrode gap, reaction time and pH value on the crystallization of Fe 3 O 4 and uranium removal efficiencies were investigated. More than 90% uranium in the solution was precipitated with Fe 3 O 4 under laboratory conditions when uranium concentration range from 0.5mg/L to 10mg/L. The Fe 3 O 4 crystallization mechanism and immobilization of uranium was proved by XPS, XRD, TEM, FTIR and VSM methods. The results indicated that the cationic (including Fe 2+ , Fe 3+ and U(VI)) migrate to cathode side under the electric field and the uranium was incorporated or adsorbed by Fe 3 O 4 which was generated at cathode while the pH ranges between 2-7. The uranium-containing precipitate of Fe 3 O 4 can exist stably at the acid concentration below 60g/L. Furthermore, the precipitate may be used as valuable resources for uranium or iron recycling, which resulted in no secondary pollution in the removal of uranium from aqueous solution. Copyright © 2017. Published by Elsevier B.V.

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

NASA Astrophysics Data System (ADS)

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

2017-11-01

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

Aerial radiometric and magnetic reconnaissance survey of portions of Arizona, Idaho, Montana, New Mexico, South Dakota and Washington. Volume 2-F. Lewistown Quadrangle. Final report

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

Not Available

1979-06-01

Results of a high-sensitivity, aerial, gamma-ray spectrometer and magnetometer survey of the Lewistown Quadrangle, Montana, are presented. Instrumentation and methods are described in Volume 1 of this final report. Statistical and geological analysis of the radiometric data revealed 58 uranium anomalies worthy of field-checking as possible prospects. One anomaly may be associated with the Cambrian Flathead Quartzite that may contain deposits similar to the Blind River and Rand uranium deposits. Three anomalies may be indicative of sandstone-type deposits in Jurassic rocks, particularly the Morrison Formation, which hosts uranium mineralization elsewhere. One of the latter anomalies is also related to rocksmore » of the Mississippian Madison Group, and this suggests the possible presence of uranium in limestones of the Mission Canyon Formation. There are 45 anomalies related to the Cretaceous rocks. Lignite in the Hell Creek and Judith River formations and Eagle Sandstone may have caused the formation of 22 epigenetic uranium deposits. Many anomalies occur in the Bearpaw Shale and Claggett Formation. However, only five are considered significant of the remainder are expected to be caused by large amounts of radioactive bentonite or bentonitic shale. Two other Cretaceous units that may host sandstone-type deposits are the Colorado Shale and Kootenai Formation that register 16 and two anomalies respectively. Only one anomaly pertains to Tertiary rocks, and it may be indicative of vein-type deposits in the intrusives of the Judith Mountains. These rocks may also act as source rocks for deposits surrounding the Judith Mountains. Eight anomalies related only to Quaternary units may be demonstrative of uranium-rich source rocks that could host uranium mineralization.Several anomalies are located close to oil fields and may have been cause by radium-rich oil-field brines.« less

Handbook on surficial uranium deposits. Chapter 3. World distribution relative to climate and physical setting

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

Carlisle, D

1983-01-01

This chapter discusses regional controls which affect the world distribution of surficial chemogenic uranium deposits. The most important of these are (1) climate, (2) geomorphology, including physiographic and climatic stability, and (3) provenance, i.e., the weathering terrain from which uranium and associated substances are derived. The three economically important environments are the calcrete environment, simple evaporative environments and paludal environments. Of these three categories, the calcrete uranium environment is probably the most uniquely constrained in terms of regional climate, geomorphic setting, provenance (vanadium as well as uranium) and especially the need for long term stability of both climate and physiography.more » Purely evaporative deposits, though subject to some of the same kinds of constraints, can also reflect local circumstances and a wider range of climates, physiographic settings, and source terrains. The third category encompassing bogs, marshes and organic-rich playas can form under an even wider range of climates and settings provided only that organic materials accumulate in abundance and are contacted by uranium-bearing waters. For all of these reasons and also because of the great economic importance of the calcrete environment as well as its relative novelty and complexity the discussion in this chapter is focused on calcrete, dolocrete and gypcrete uranium deposits. Objective data are reviewed first follwed by inferences and suggestions. 13 figures.« less

Highly Efficient Interception and Precipitation of Uranium(VI) from Aqueous Solution by Iron-Electrocoagulation Combined with Cooperative Chelation by Organic Ligands.

PubMed

Li, Peng; Zhun, Bao; Wang, Xuegang; Liao, PingPing; Wang, Guanghui; Wang, Lizhang; Guo, Yadan; Zhang, Weimin

2017-12-19

A new strategy combining iron-electrocoagulation and organic ligands (OGLs) cooperative chelation was proposed to screen and precipitate low concentrations (0-18.52 μmol/L) of uranium contaminant in aqueous solution. We hypothesized that OGLs with amino, hydroxyl, and carboxyl groups hydrophobically/hydrophilically would realize precuring of uranyl ion at pH < 3.0, and the following iron-electrocoagulation would achieve faster and more efficient uranium precipitation. Experimentally, the strategy demonstrated highly efficient uranium(VI) precipitation efficiency, especially with hydrophilic macromolecular OGLs. The uranium removal efficiency at optimized experimental condition reached 99.65%. The decrease of zeta potential and the lattice enwrapping between U-OGLs chelates and flocculation precursor were ascribed to the enhanced uranium precipitation activity. Uranium was precipitated as oxides of U(VI) or higher valences that were easily captured in aggregated micelles under low operation current potential. The actual uranium tailing wastewater was treated, and a satisfied uranium removal efficiency of 99.02% was discovered. After elution of the precipitated flocs, a concentrated uranium solution (up to 106.52 μmol/L) with very few other metallic impurities was obtained. Therefore, the proposed strategy could remove uranium and concentrate it concurrently. This work could provide new insights into the purification and recovery of uranium from aqueous solutions in a cost-effective and environmentally friendly process.

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

PubMed

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

2016-12-01

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

Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits

NASA Astrophysics Data System (ADS)

Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly D.; Roebbert, Yvonne; Weyer, Stefan; Bernier-Latmani, Rizlan; Borch, Thomas

2017-06-01

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (~58-89%) of U is bound as U(IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U(VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotope signatures, consistent with largely biotic reduction of U(VI) to U(IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U(IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.

Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits

PubMed Central

Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly D.; Roebbert, Yvonne; Weyer, Stefan; Bernier-Latmani, Rizlan; Borch, Thomas

2017-01-01

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (∼58-89%) of U is bound as U(IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U(VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotope signatures, consistent with largely biotic reduction of U(VI) to U(IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U(IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment. PMID:28569759

Biogenic non-crystalline U (IV) revealed as major component in uranium ore deposits

DOE PAGES

Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly D.; ...

2017-06-01

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U (VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U (IV) generated through biologically mediated U (VI) reduction is the predominant U (IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (~58-89%) of U is bound as U (IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U (VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotopemore » signatures, consistent with largely biotic reduction of U (VI) to U (IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U (IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.« less

Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits.

PubMed

Bhattacharyya, Amrita; Campbell, Kate M; Kelly, Shelly D; Roebbert, Yvonne; Weyer, Stefan; Bernier-Latmani, Rizlan; Borch, Thomas

2017-06-01

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U (VI) ) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U (IV)  generated through biologically mediated U (VI)  reduction is the predominant U (IV)  species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (∼58-89%) of U is bound as U (IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U (VI) represent only minor components. The uranium deposit exhibited mostly 238 U-enriched isotope signatures, consistent with largely biotic reduction of U (VI) to U (IV) . This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U (IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.

Biogenic non-crystalline U (IV) revealed as major component in uranium ore deposits

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

Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly D.

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U (VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U (IV) generated through biologically mediated U (VI) reduction is the predominant U (IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (~58-89%) of U is bound as U (IV) to C-containing organic functional groups or inorganic carbonate, while uraninite and U (VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotopemore » signatures, consistent with largely biotic reduction of U (VI) to U (IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U (IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.« less

Biogenic non-crystalline U(IV) revealed as major component in uranium ore deposits

USGS Publications Warehouse

Bhattacharyya, Amrita; Campbell, Kate M.; Kelly, Shelly; Roebbert, Yvonne; Weyer, Stefan; Bernier-Latmani, Rizlan; Borch, Thomas

2017-01-01

Historically, it is believed that crystalline uraninite, produced via the abiotic reduction of hexavalent uranium (U(VI)) is the dominant reduced U species formed in low-temperature uranium roll-front ore deposits. Here we show that non-crystalline U(IV) generated through biologically mediated U(VI) reduction is the predominant U(IV) species in an undisturbed U roll-front ore deposit in Wyoming, USA. Characterization of U species revealed that the majority (∼58-89%) of U is bound as U(IV)to C-containing organic functional groups or inorganic carbonate, while uraninite and U(VI) represent only minor components. The uranium deposit exhibited mostly 238U-enriched isotope signatures, consistent with largely biotic reduction of U(VI) to U(IV). This finding implies that biogenic processes are more important to uranium ore genesis than previously understood. The predominance of a relatively labile form of U(IV) also provides an opportunity for a more economical and environmentally benign mining process, as well as the design of more effective post-mining restoration strategies and human health-risk assessment.

Remediation of uranium in-situ leaching area at Straz Pod Ralskem, Czech Republic

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

Vokal, Vojtech; Muzak, Jiri; Ekert, Vladimir

2013-07-01

A large-scale development in exploration and production of uranium ores in the Czech Republic was done in the 2nd half of the 20. century. Many uranium deposits were discovered in the territory of the Czech Republic. One of the most considerable deposits in the Czech Republic is the site Hamr na Jezere - Straz pod Ralskem where both mining methods - the underground mining and the acidic in-situ leaching - were used. The extensive production of uranium led to widespread environmental impacts and contamination of ground waters. Over the period of 'chemical' leaching of uranium (ca. 32 years), a totalmore » of more than 4 million tons of sulphuric acid and other chemicals have been injected into the ground. Most of the products (approx. 99.5 %) of the acids reactions with the rocks are located in the Cenomanian aquifer. The contamination of Cenomanian aquifer covers the area larger then 27 km{sup 2}. The influenced volume of groundwater is more than 380 million m{sup 3}. The total amount of dissolved SO{sub 4}{sup 2-} is about 3.6 million tons. After 1990 a large-scale environmental program was established and the Czech government decided to liquidate the ISL Mine and start the remediation in 1996. The remediation consists of contaminated groundwater pumping, removing of the contaminants and discharging or reinjection of treated water. Nowadays four main remedial technological installations with sufficient capacity for reaching of the target values of remedial parameters in 2037 are used - the 'Station for Acid Solutions Liquidation No. One', the 'Mother liquor reprocessing' station, the 'Neutralization and Decontamination Station NDS 6' and the 'Neutralization and Decontamination Station NDS 10'. It is expected that the amount of withdrawn contaminants will vary from 80 000 to 120 000 tons per year. Total costs of all remediation activities are expected to be in excess of 2 billion EUR. (authors)« less

Laser removal of loose uranium compound contamination from metal surfaces

NASA Astrophysics Data System (ADS)

Roberts, D. E.; Modise, T. S.

2007-04-01

Pulsed laser removal of surface contamination of uranyl nitrate and uranium dioxide from stainless steel has been studied. Most of the loosely bound contamination has been removed at fluence levels below 0.5 J cm -2, leaving about 5% fixed contamination for uranyl nitrate and 15% for uranium dioxide. Both alpha and beta activities are then sufficiently low that contaminated objects can be taken out of a restricted radiation area for re-use. The ratio of beta to alpha activity is found to be a function of particle size and changes during laser removal. In a separate experiment using technetium-99m, the collection of removed radioactivity in the filter was studied and an inventory made of removed and collected contamination.

The Robinson and Weatherly uraniferous pyrobitumen deposits near Placerville, San Miguel County, Colorado

USGS Publications Warehouse

Wilmarth, V.R.; Vickers, R.C.

1953-01-01

Uranium deposits that contain uraniferous pyrobitumen of possible hydrothermal origin occur at the Weatherly and Robinson properties near Placerville, San Miguel County, Colo. These deposits were mined for copper, silver, and gold more than 50 years ago and were developed for uranium in 1950. The Robinson property, half a mile east of Placerville, consists of the White Spar, New Discovery Lode, and Barbara Jo claims. The rocks in this area are nearly horizontal sandstones, shales, limestones, and conglomerates of the Cutler formation of Permian age and the Dolores formation of Triassic and Jurassic (?) age. These rocks have been faulted extensively and intruded by a Tertiary (?) andesite porphyry dike. Uranium-bearing pyrobitumen associated with tennantite, tetrahedrite, galena, sphalerite, chalcopyrite, bornite, azurite, malachite, calcite, barite, and quartz occurs in a lenticular body as much as 40 feet long and 6 feet wide along a northwest-trending, steeply dipping normal fault. The uranium content of eleven samples from the uranium deposit ranges from 0.001 to 0.045 percent uranium and averages about 0.02 percent uranium. The Weatherly property, about a mile northwest of Placerville, consists of the Black King claims nos. 1, 4, and 5. The rocks in this area include the complexly faulted Cutler formation of Permian age and the Dolores formation of Triassic and Jurassic (?) age. Uranium-bearing pyrobitumen arid uranophane occur, along a northwest-trending, steeply dipping normal fault and in the sedimentary rocks on the hanging wall of the fault. Lens-shaped deposits in the fault zone are as much as 6 feet long and 2 feet wide and contain as much as 9 percent uranium; whereas channel samples across the fault zone contain from 0.001 to 0.014 percent uranium. Tetrahedrite, chalcopyrite, galena, sphalerite, fuchsite, malachite, azurite, erythrite, bornite, and molybdite in a gangue of pyrite, calcite, barite, and quartz are associated with the uraniferous material. In the sedimentary rocks on the hanging wall, uranium-bearing pyrobitumen occurs in replacement lenses as much as,8 inches wide and 6 feet long, and in nodules as much as 6 inches in diameter for approximately 100 feet away from the fault. Pyrite and calcite are closely associated with the uraniferous material in the sedimentary rocks. Samples from the replacement bodies contain from 0. 007 to 1.4 percent uranium.

Volcanogenic Uranium Deposits: Geology, Geochemical Processes, and Criteria for Resource Assessment

USGS Publications Warehouse

Nash, J. Thomas

2010-01-01

Felsic volcanic rocks have long been considered a primary source of uranium for many kinds of uranium deposits, but volcanogenic uranium deposits themselves have generally not been important resources. Until the past few years, resource summaries for the United States or the world generally include volcanogenic in the broad category of 'other deposits' because they comprised less than 0.5 percent of past production or estimated resources. Exploration in the United States from the 1940s through 1982 discovered hundreds of prospects in volcanic rocks, of which fewer than 20 had some recorded production. Intensive exploration in the late 1970s found some large deposits, but low grades (less than about 0.10 percent U3O8) discouraged economic development. A few deposits in the world, drilled in the 1980s and 1990s, are now known to contain large resources (>20,000 tonnes U3O8). However, research on ore-forming processes and exploration for volcanogenic deposits has lagged behind other kinds of uranium deposits and has not utilized advances in understanding of geology, geochemistry, and paleohydrology of ore deposits in general and epithermal deposits in particular. This review outlines new ways to explore and assess for volcanogenic deposits, using new concepts of convection, fluid mixing, and high heat flow to mobilize uranium from volcanic source rocks and form deposits that are postulated to be large. Much can also be learned from studies of epithermal metal deposits, such as the important roles of extensional tectonics, bimodal volcanism, and fracture-flow systems related to resurgent calderas. Regional resource assessment is helped by genetic concepts, but hampered by limited information on frontier areas and undiscovered districts. Diagnostic data used to define ore deposit genesis, such as stable isotopic data, are rarely available for frontier areas. A volcanic environment classification, with three classes (proximal, distal, and pre-volcanic structures), permits use of geologic features on 1:500,000 to 1:100,000 scale maps. Geochemical databases for volcanic rocks are postulated to be more effective than databases for stream sediments or surface radioactivity, both of which tend to be inconsistent because of variable leaching of uranium from soils. Based on empirical associations, spatial associations with areas of wet paleoclimate, adjacent oil and gas fields, or evaporite beds are deemed positive. Most difficult to estimate is the location of depositional traps and reduction zones, in part because they are mere points at regional scale. Grade and tonnage data are reviewed and discussed for 32 deposits in the world. Experience of mining engineers and geologists in Asia suggests that tonnages could be higher than presently known in the Western Hemisphere. Geological analysis, and new data from Asia, suggest a typical or median deposit tonnage of about 5,000 tonnes U3O8, and an optimistic forecast of discoveries in the range of 5,000 to 20,000 tonnes U3O8. The likely grade of undiscovered deposits could be about 0.15 percent U3O8 , based on both western and eastern examples. Volcanic terrane is under-explored, relative to other kinds of uranium deposits, and is considered a favorable frontier area for new discoveries.

Decontamination of uranium-contaminated waste oil using supercritical fluid and nitric acid.

PubMed

Sung, Jinhyun; Kim, Jungsoo; Lee, Youngbae; Seol, Jeunggun; Ryu, Jaebong; Park, Kwangheon

2011-07-01

The waste oil used in nuclear fuel processing is contaminated with uranium because of its contact with materials or environments containing uranium. Under current law, waste oil that has been contaminated with uranium is very difficult to dispose of at a radioactive waste disposal site. To dispose of the uranium-contaminated waste oil, the uranium was separated from the contaminated waste oil. Supercritical R-22 is an excellent solvent for extracting clean oil from uranium-contaminated waste oil. The critical temperature of R-22 is 96.15 °C and the critical pressure is 49.9 bar. In this study, a process to remove uranium from the uranium-contaminated waste oil using supercritical R-22 was developed. The waste oil has a small amount of additives containing N, S or P, such as amines, dithiocarbamates and dialkyldithiophosphates. It seems that these organic additives form uranium-combined compounds. For this reason, dissolution of uranium from the uranium-combined compounds using nitric acid was needed. The efficiency of the removal of uranium from the uranium-contaminated waste oil using supercritical R-22 extraction and nitric acid treatment was determined.

High temperature UF6 RF plasma experiments applicable to uranium plasma core reactors

NASA Technical Reports Server (NTRS)

Roman, W. C.

1979-01-01

An investigation was conducted using a 1.2 MW RF induction heater facility to aid in developing the technology necessary for designing a self critical fissioning uranium plasma core reactor. Pure, high temperature uranium hexafluoride (UF6) was injected into an argon fluid mechanically confined, steady state, RF heated plasma while employing different exhaust systems and diagnostic techniques to simulate and investigate some potential characteristics of uranium plasma core nuclear reactors. The development of techniques and equipment for fluid mechanical confinement of RF heated uranium plasmas with a high density of uranium vapor within the plasma, while simultaneously minimizing deposition of uranium and uranium compounds on the test chamber peripheral wall, endwall surfaces, and primary exhaust ducts, is discussed. The material tests and handling techniques suitable for use with high temperature, high pressure, gaseous UF6 are described and the development of complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma, effluent exhaust gases, and residue deposited on the test chamber and exhaust system components is reported.

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

USGS Publications Warehouse

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 precipitation of uranium minerals. At the deepest exposed levels, wall-rocks were altered to sericite; and uraninite, coffinite, jordisite, fluorite, molybdenite, quartz, and pyrite were deposited in the veins. The fluids were progressively oxidized and cooled at higher levels in the system by boiling and degassing; iron-bearing minerals in wall rocks were oxidized to hematite, and quartz, fluorite, minor siderite, and uraninite were deposited in the veins. Near the ground surface, the fluids were acidified by condensation of volatiles and oxidation of hydrogen sulfide in near-surface, steam-heated, ground waters; wall rocks were altered to kaolinite, and quartz fluorite, and uraninite were deposited in veins. Secondary uranium minerals, hematite, and gypsum formed during supergene alteration later in the Cenozoic when the upper part of the mineralized system was exposed by erosion.

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

USGS Publications Warehouse

Bartsch-Winkler, Susan B.

1992-01-01

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

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

USGS Publications Warehouse

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

1995-01-01

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

Geological and geochronological evidence for the effect of Paleogene and Miocene uplift of the Northern Ordos Basin on the formation of the Dongsheng uranium district, China

NASA Astrophysics Data System (ADS)

Zhang, Chuang; Yi, Chao; Dong, Qian; Cai, Yu-Qi; Liu, Hong-Xu

2018-02-01

The Dongsheng uranium district, located in the northern part of the Ordos Basin, contains the largest known sandstone-hosted uranium deposit in China. This district contains (from west to east) the Daying, Nalinggou, and Dongsheng uranium deposits that host tens of thousands of metric tonnes of estimated recoverable uranium resources at an average grade of 0.05% U. These uranium orebodies are generally hosted by the lower member of the Zhiluo Formation and are dominantly roll or tabular in shape. The uranium deposits in this district formed during two stages of mineralization (as evidenced by U-Pb dating) that occurred at 65-60 and 25 Ma. Both stages generated coffinite, pitchblende, anatase, pyrite, and quartz, with or without sericite, chlorite, calcite, fluorite, and hematite. The post-Late Cretaceous uplift of the Northern Ordos Basin exposed the northern margins of the Zhiluo Formation within the Hetao depression at 65-60 Ma, introducing groundwater into the formation and generating the first stage of uranium mineralization. The Oligocene (∼25 Ma) uplift of this northern margin exposed either the entirety of the southern flank of the Hetao depression or only the clastic sedimentary part of this region, causing a second gravitational influx of groundwater into the Zhiluo Formation and forming the second stage of uranium mineralization.

Inhalation of uranium nanoparticles: respiratory tract deposition and translocation to secondary target organs in rats.

PubMed

Petitot, Fabrice; Lestaevel, Philippe; Tourlonias, Elie; Mazzucco, Charline; Jacquinot, Sébastien; Dhieux, Bernadette; Delissen, Olivia; Tournier, Benjamin B; Gensdarmes, François; Beaunier, Patricia; Dublineau, Isabelle

2013-03-13

Uranium nanoparticles (<100 nm) can be released into the atmosphere during industrial stages of the nuclear fuel cycle and during remediation and decommissioning of nuclear facilities. Explosions and fires in nuclear reactors and the use of ammunition containing depleted uranium can also produce such aerosols. The risk of accidental inhalation of uranium nanoparticles by nuclear workers, military personnel or civilian populations must therefore be taken into account. In order to address this issue, the absorption rate of inhaled uranium nanoparticles needs to be characterised experimentally. For this purpose, rats were exposed to an aerosol containing 10⁷ particles of uranium per cm³ (CMD=38 nm) for 1h in a nose-only inhalation exposure system. Uranium concentrations deposited in the respiratory tract, blood, brain, skeleton and kidneys were determined by ICP-MS. Twenty-seven percent of the inhaled mass of uranium nanoparticles was deposited in the respiratory tract. One-fifth of UO₂ nanoparticles were rapidly cleared from lung (T(½)=2.4 h) and translocated to extrathoracic organs. However, the majority of the particles were cleared slowly (T(½)=141.5 d). Future long-term experimental studies concerning uranium nanoparticles should focus on the potential lung toxicity of the large fraction of particles cleared slowly from the respiratory tract after inhalation exposure. Copyright © 2013 Elsevier Ireland Ltd. All rights reserved.

Precambrian uranium-bearing quartz-pebble conglomerates: exploration model and United States resource potential

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

Houston, R.S.; Karlstrom, K.E.

1979-11-01

Uranium has been discovered in fluvial quartz-pebble conglomerates in most of the Precambrian shield areas of the world, including the Canadian, African, South American, Indian, Baltic, and Australian shields. Occurrences in these and other areas are shown. Two of these occurrences, the Huronian supergroup of Canada and the Witwatersrand deposit of South Africa contain 20 to 30 percent of the planet's known uranium reserves. Thus it is critical that we understand the origin of these deposits and develop exploration models that can aid in finding new deposits. Inasmuch as these uranium-bearing conglomerates are confined almost entirely to rocks of Precambrianmore » age, Part I of this review begins with a discussion of Precambrian geology as it applies to the conglomerates. This is followed by a discussion of genetic concepts, a discussion of unresolved problems, and finally a suggested exploration model. Part II summarizes known and potential occurrences of Precambrian fossil placers in the world and evaluates them in terms of the suggested exploration model. Part III discusses the potential for important Precambrian fossil-placer uranium deposits in the United States and includes suggestions that may be helpful in establishing an exploration program in this country. Part III also brings together new (1975-1978) data on uranium occurrences in the Precambrian of the Wyoming Province. Part IV is a complete bibliography of Precambrian fossil placers, divided according to geographical areas. In total, this paper is designed to be a comprehensive review of Precambrian uranium-bearing fossil placers which will be of use to uranium explorationists and to students of Precambrian geology.« less

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

USGS Publications Warehouse

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

1956-01-01

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

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

NASA Astrophysics Data System (ADS)

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

2015-12-01

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

Geology and ore deposits of the McDermitt Caldera, Nevada-Oregon

USGS Publications Warehouse

Rytuba, James J.

1976-01-01

The McDermitt caldera is a Miocene collapse structure along the Nevada-Oregon border. The oval-shaped caldera is bounded by arcuate normal faults on the north and south and by rhyolite ring domes on the west. Precollapse ash-flow tuffs exposed within the south caldera rim consist of three cooling units and are peralkaline in composition. Refractive indexes of nonhydrated glasses from basal vitrophyres of the. units range from 1.493 to 1.503 and are typical of comendites. Post-collapse intracaldera rocks consist of tuffaceous lake sediments, rhyolite flows and domes, and ash-flow tuffs. Within the caldera are the mercury mines of Bretz, Cordero, McDermitt, Opalite, and Ruja and the Moonlight uranium mine. The mercury mines are adjacent to ring fracture faults, and the uranium mine and other uranium occurrences are located within rhyolite ring domes. Fluid inclusions in quartz indicate a deposition temperature of 340?C for the uranium deposit and 200?C for the mercury deposits. The mercury deposits formed at shallow depth by replacement of lakebed sediments and volcanic rocks.

Investigation of applications for high-power, self-critical fissioning uranium plasma reactors

NASA Technical Reports Server (NTRS)

Rodgers, R. J.; Latham, T. S.; Krascella, N. L.

1976-01-01

Analytical studies were conducted to investigate potentially attractive applications for gaseous nuclear cavity reactors fueled by uranium hexafluoride and its decomposition products at temperatures of 2000 to 6000 K and total pressures of a few hundred atmospheres. Approximate operating conditions and performance levels for a class of nuclear reactors in which fission energy removal is accomplished principally by radiant heat transfer from the high temperature gaseous nuclear fuel to surrounding absorbing media were determined. The results show the radiant energy deposited in the absorbing media may be efficiently utilized in energy conversion system applications which include (1) a primary energy source for high thrust, high specific impulse space propulsion, (2) an energy source for highly efficient generation of electricity, and (3) a source of high intensity photon flux for heating working fluid gases for hydrogen production or MHD power extraction.

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

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

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

1981-02-01

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

Paleontological analysis of a lacustrine carbonaceous uranium deposit at the Anderson mine, Date Creek basin, west-central Arizona (U.S.A.)

USGS Publications Warehouse

Otton, J.K.; Bradbury, J.P.; Forester, R.M.; Hanley, J.H.

1990-01-01

The Tertiary sedimentary sequence of the Date Creek basin area of Arizona is composed principally of intertonguing alluvial-fan and lacustrine deposits. The lacustrine rocks contain large intermediate- to, locally, high-grade uranium deposits that form one of the largest uranium resources in the United States (an estimated 670,000 tons of U3O8 at an average grade of 0.023% is indicated by drilling to date). At the Anderson mine, about 50,000 tons of U3O8 occurs in lacustrine carbonaceous siltstones and mudstones (using a cutoff grade of 0.01%). The Anderson mine constitutes a new class of ore deposit, a lacustrine carbonaceous uranium deposit. Floral and faunal remains at the Anderson mine played a critical role in creating and documenting conditions necessary for uranium mineralization. Organic-rich, uraniferous rocks at the Anderson mine contain plant remains and ostracodes having remarkably detailed preservation of internal features because of infilling by opaline silica. This preservation suggests that the alkaline lake waters in the mine area contained high concentrations of dissolved silica and that silicification occurred rapidly, before compaction or cementation of the enclosing sediment. Uranium coprecipitated with the silica. Thinly laminated, dark-colored, siliceous beds contain centric diatoms preserved with carbonaceous material suggesting that lake waters at the mine were locally deep and anoxic. These alkaline, silica-charged waters and a stagnant, anoxic environment in parts of the lake were necessary conditions for the precipitation of large amounts of uranium in the lake-bottom sediments. Sediments at the Anderson mine contain plant remains and pollen that were derived from diverse vegetative zones suggesting about 1500 m of relief in the area at the time of deposition. The pollen suggests that the valley floor was semiarid and subtropical, whereas nearby mountains supported temperate deciduous forests. ?? 1990.

Effect of Reaction Pathway on the Extent and Mechanism of Uranium(VI) Immobilization with Calcium and Phosphate

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

Mehta, Vrajesh S.; Maillot, Fabien; Wang, Zheming

Phosphate addition to subsurface environments contaminated with uranium can be used as an in situ remediation approach. Batch experiments were conducted to evaluate the dependence of the extent and mechanism of uranium uptake on the pathway for reaction with calcium phosphates. At pH 4.0 and 6.0 uranium uptake occurred via autunite (Ca(UO2)(PO4)3) precipitation irrespective of the starting forms of calcium and phosphate. At pH 7.5, the uptake mechanism depended on the nature of the calcium and phosphate. When dissolved uranium, calcium, and phosphate were added simultaneously, uranium was structurally incorporated into a newly formed amorphous calcium phosphate solid. Adsorption wasmore » the dominant removal mechanism for uranium contacted with pre-formed amorphous calcium phosphate solids,. When U(VI) was added to a suspension containing amorphous calcium phosphate solids as well as dissolved calcium and phosphate, then removal occurred through precipitation (57±4 %) of autunite and adsorption (43±4 %) onto calcium phosphate. The solid phase speciation of the uranium was determined using X-ray absorption spectroscopy and laser induced fluorescence spectroscopy. Dissolved uranium, calcium, and phosphate concentrations with saturation index calculations helped identify removal mechanisms and determine thermodynamically favorable solid phases.« less

Anaerobic bioremediation of hexavalent uranium in groundwater by reductive precipitation with methanogenic granular sludge.

PubMed

Tapia-Rodriguez, Aida; Luna-Velasco, Antonia; Field, Jim A; Sierra-Alvarez, Reyes

2010-04-01

Uranium has been responsible for extensive contamination of groundwater due to releases from mill tailings and other uranium processing waste. Past evidence has confirmed that certain bacteria can enzymatically reduce soluble hexavalent uranium (U(VI)) to insoluble tetravalent uranium (U(IV)) under anaerobic conditions in the presence of appropriate electron donors. This paper focuses on the evaluation of anaerobic granular sludge as a source of inoculum for the bioremediation of uranium in water. Batch experiments were performed with several methanogenic anaerobic granular sludge samples and different electron donors. Abiotic controls consisting of heat-killed inoculum and non-inoculated treatments confirmed the biological removal process. In this study, unadapted anaerobic granular sludge immediately reduced U(VI), suggesting an intrinsic capacity of the sludge to support this process. The high biodiversity of anaerobic granular sludge most likely accounts for the presence of specific microorganisms capable of reducing U(VI). Oxidation by O(2) was shown to resolubilize the uranium. This observation combined with X-ray diffraction evidence of uraninite confirmed that the removal during anaerobic treatment was due to reductive precipitation. The anaerobic removal activity could be sustained after several respikes of U(VI). The U(VI) removal was feasible without addition of electron donors, indicating that the decay of endogenous biomass substrates was contributing electron equivalents to the process. Addition of electron donors, such as H(2) stimulated the removal of U(VI) to varying degrees. The stimulation was greater in sludge samples with lower endogenous substrate levels. The present work reveals the potential application of anaerobic granular sludge for continuous bioremediation schemes to treat uranium-contaminated water. Copyright (c) 2009 Elsevier Ltd. All rights reserved.

PROCESS FOR REMOVING NOBLE METALS FROM URANIUM

DOEpatents

Knighton, J.B.

1961-01-31

A pyrometallurgical method is given for purifying uranium containing ruthenium and palladium. The uranium is disintegrated and oxidized by exposure to air and then the ruthenium and palladium are extracted from the uranium with molten zinc.

STRIPPING OF URANIUM FROM ORGANIC EXTRACTANTS

DOEpatents

Crouse, D.J. Jr.

1962-09-01

A liquid-liquid extraction method is given for recovering uranium values from uranium-containing solutions. Uranium is removed from a uranium-containing organic solution by contacting said organic solution with an aqueous ammonium carbonate solution substantially saturated in uranium values. A uranium- containing precipitate is thereby formed which is separated from the organic and aqueous phases. Uranium values are recovered from this separated precipitate. (AE C)

Biogeochemical prospecting for uranium with conifers: results from the Midnite Mine area, Washington

USGS Publications Warehouse

Nash, J. Thomas; Ward, Frederick Norville

1977-01-01

The ash of needles, cones, and duff from Ponderosa pine (Pinus ponderosa Laws) growing near uranium deposits of the Midnite mine, Stevens County, Wash., contain as much as 200 parts per million (ppm) uranium. Needle samples containing more than 10 ppm uranium define zones that correlate well with known uranium deposits or dumps. Dispersion is as much as 300 m but generally is less. Background is about 1 ppm. Tree roots are judged to be sampling ore, low-grade uranium halo, or ground water to a depth of about 15 m. Uptake of uranium by Douglas fir (Pseudotsuga menziesii (Mirb.) Franco) needles appears to be about the same as by Ponderosa pine needles. Cones and duff are generally enriched in uranium relate to needles. Needles, cones, and duff are recommended as easily collected, uncomplicated sample media for geochemical surveys. Samples can be analyzed by standard methods and total cost per sample kept to about $6.

Removal and recovery of uranium(VI) by waste digested activated sludge in fed-batch stirred tank reactor.

PubMed

Jain, Rohan; Peräniemi, Sirpa; Jordan, Norbert; Vogel, Manja; Weiss, Stephan; Foerstendorf, Harald; Lakaniemi, Aino-Maija

2018-05-24

This study demonstrated the removal and recovery of uranium(VI) in a fed-batch stirred tank reactor (STR) using waste digested activated sludge (WDAS). The batch adsorption experiments showed that WDAS can adsorb 200 (±9.0) mg of uranium(VI) per g of WDAS. The maximum adsorption of uranium(VI) was achieved even at an acidic initial pH of 2.7 which increased to a pH of 4.0 in the equilibrium state. Desorption of uranium(VI) from WDAS was successfully demonstrated from the release of more than 95% of uranium(VI) using both acidic (0.5 M HCl) and alkaline (1.0 M Na 2 CO 3 ) eluents. Due to the fast kinetics of uranium(VI) adsorption onto WDAS, the fed-batch STR was successfully operated at a mixing time of 15 min. Twelve consecutive uranium(VI) adsorption steps with an average adsorption efficiency of 91.5% required only two desorption steps to elute more than 95% of uranium(VI) from WDAS. Uranium(VI) was shown to interact predominantly with the phosphoryl and carboxyl groups of the WDAS, as revealed by in situ infrared spectroscopy and time-resolved laser-induced fluorescence spectroscopy studies. This study provides a proof-of-concept of the use of fed-batch STR process based on WDAS for the removal and recovery of uranium(VI). Copyright © 2018 Elsevier Ltd. All rights reserved.

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

USGS Publications Warehouse

Lindsey, David A.

1975-01-01

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

Radioactive deposits in California

USGS Publications Warehouse

Walker, George W.; Lovering, Tom G.

1954-01-01

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

Method to remove uranium/vanadium contamination from groundwater

DOEpatents

Metzler, Donald R.; Morrison, Stanley

2004-07-27

A process for removing uranium/vanadium-based contaminants from groundwater using a primary in-ground treatment media and a pretreatment media that chemically adjusts the groundwater contaminant to provide for optimum treatment by the primary treatment media.

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

USGS Publications Warehouse

Ridgley, Jennie L.

1978-01-01

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

Host rocks and their alterations as related to uranium-bearing veins in the United States

USGS Publications Warehouse

Walker, George W.

1956-01-01

This paper, dealing with the different kinds of host rocks and their alterations associated with uranium-bearing veins in the United States, is a chapter of a comprehensive report entitled , "Geology of uranium-bearing vein deposits in the United States," in preparation by George W. Walker, Frank W. Osterwald, and others. The comprehensive report will include detailed information on tectonic and structural setting, kinds of host rocks, wall-rock alteration, mineralogy, physical characteristics, processes of deposition, and concepts of origin of uraniferous veins; but, because it will not be completed until sometime in the future, some chapters of the report are being transmitted as they are finished. Part of an introductory chapter to the comprehensive report entitled, "Classification and distribution of uranium-bearing veins in the United States" (Walker and Osterwald, 1956) has already been transmitted; several of the terms used herein are defined in the introductory chapter. Data included in this chapter demonstrate that uranium-bearing veins are: 1) in rocks of nearly all textural, chemical, and mineralogic types; 2) most abundant in holocrystalline, commonly equigranular, igeneous and metamorphic rocks characterized by a moderate to high silica content and and by similar physical properties. Although some of the physiochemical properties of the host rocks are discussed in terms of favorability or nonfavoribility for uranium deposition, the principal purpose of this chapter is to establish the petroloic environment in which uranium-bearing veins have been found. Because favorability or nonfavorability of host rocks is related complexly to the chemistry of ore solutions and to methods or uranium transport and deposition, several hypothetical processes of transport and deposition have been referred to briefly; these and other hypotheses will be outlines and discussed in greater detail in a subsequent chapter. The compilation of data leading to this report and its preparation by a member of the Uranium Research and Resource Section, U.S. Geological Survey, was done on behalf of the Division of Raw Materials, U.S. Atomic Energy Commission. The report is based on both published and unpublished information collected principally by personnel of the U.S. Geological Survey, the U.S. Atomic Energy Commission or its predecessor organization, the Manhattan Engineer District, and to a lesser extent by staff members of other Federal or State agencies and by geologists in private industry. Information concerning foreign uranium-bearing vein deposits has been extracted almost exclusively from published reports; references to these and other data are included at appropriate places.

Global Uranium And Thorium Resources: Are They Adequate To Satisfy Demand Over The Next Half Century?

NASA Astrophysics Data System (ADS)

Lambert, I. B.

2012-04-01

This presentation will consider the adequacy of global uranium and thorium resources to meet realistic nuclear power demand scenarios over the next half century. It is presented on behalf of, and based on evaluations by, the Uranium Group - a joint initiative of the OECD Nuclear Energy Agency and the International Atomic Energy Agency, of which the author is a Vice Chair. The Uranium Group produces a biennial report on Uranium Resources, Production and Demand based on information from some 40 countries involved in the nuclear fuel cycle, which also briefly reviews thorium resources. Uranium: In 2008, world production of uranium amounted to almost 44,000 tonnes (tU). This supplied approximately three-quarters of world reactor requirements (approx. 59,000 tU), the remainder being met by previously mined uranium (so-called secondary sources). Information on availability of secondary sources - which include uranium from excess inventories, dismantling nuclear warheads, tails and spent fuel reprocessing - is incomplete, but such sources are expected to decrease in market importance after 2013. In 2008, the total world Reasonably Assured plus Inferred Resources of uranium (recoverable at less than 130/kgU) amounted to 5.4 million tonnes. In addition, it is clear that there are vast amounts of uranium recoverable at higher costs in known deposits, plus many as yet undiscovered deposits. The Uranium Group has concluded that the uranium resource base is more than adequate to meet projected high-case requirements for nuclear power for at least half a century. This conclusion does not assume increasing replacement of uranium by fuels from reprocessing current reactor wastes, or by thorium, nor greater reactor efficiencies, which are likely to ameliorate future uranium demand. However, progressively increasing quantities of uranium will need to be mined, against a backdrop of the relatively small number of producing facilities around the world, geopolitical uncertainties and strong opposition to growth of nuclear power in a number of quarters - it is vital that the market provides incentives for exploration and development of environmentally sustainable mining operations. Thorium: World Reasonably Assured plus Inferred Resources of thorium are estimated at over 2.2 million tonnes, in hard rock and heavy mineral sand deposits. At least double this amount is considered to occur in as yet undiscovered thorium deposits. Currently, demand for thorium is insignificant, but even a major shift to thorium-fueled reactors would not make significant inroads into the huge resource base over the next half century.

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

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

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

2007-07-01

The main objectives of this work are to determine the hydrogeochemical evolution of an uranium ore and identify the main water/rock interaction processes that control the dissolved uranium content. The Mina Fe uranium-ore deposit is the most important and biggest mine worked in Spain. Sageras area is located at the north part of the Mina Fe, over the same ore deposit. The uranium deposit was not mined in Sageras and was only perturbed by the exploration activities performed 20 years ago. The studied area is located 10 Km northeast of Ciudad Rodrigo (Salamanca) at an altitude over 650 m.a.s.l. Themore » uranium mineralization is related to faults affecting the metasediments of the Upper Proterozoic to Lower Cambrian schist-graywacke complex (CEG), located in the Centro-Iberian Zone of the Hesperian Massif . The primary uranium minerals are uraninite and coffinite but numerous secondary uranium minerals have been formed as a result of the weathering processes: yellow gummite, autunite, meta-autunite, torbernite, saleeite, uranotile, ianthinite and uranopilite. The water flow at regional scale is controlled by the topography. Recharge takes place mainly in the surrounding mountains (Sierra Pena de Francia) and discharge at fluvial courses, mainly Agueda and Yeltes rivers, boundaries S-NW and NE of the area, respectively. Deep flows (lower than 100 m depth) should be upwards due to the river vicinity, with flow directions towards the W, NW or N. In Sageras-Mina Fe there are more than 100 boreholes drilled to investigate the mineral resources of the deposit. 35 boreholes were selected in order to analyze the chemical composition of groundwaters based on their depth and situation around the uranium ore. Groundwater samples come from 50 to 150 m depth. The waters are classified as calcium-bicarbonate type waters, with a redox potential that indicates they are slightly reduced (values vary between 50 to -350 mV). The TOC varies between <0.1 and 4.0 mgC/L and the dissolved uranium has a maximum value of 7.7 mg/L. According the analytical data of dissolved uranium, the mineral closest to equilibrium seems to be UO{sub 2}(am). The tritium contents in the groundwaters vary between 1.5 and 7.3 T.U. Considering that the mean value of tritium in rainwater from the studied area has a value of 4 T.U., it can be concluded that the residence times of the groundwaters are relatively short, not longer than 50 years in the oldest case. (authors)« less

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

USGS Publications Warehouse

Stuckless, J.S.; Bunting, J.A.; Nkomo, I.T.

1981-01-01

The Mount Boreas-type granite and spatially associated syenitic granitoid of Western Australia yield Pb/Pb ages of 2370+ or -100Ma and 2760+ or -210Ma, 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 (<3mu 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 20mu g/g) and are associated with large roll-type and other low temperature-type uranium deposits.-Authors

Elution of uranium and transition metals from amidoxime-based polymer adsorbents for sequestering uranium from seawater

DOE PAGES

Pan, Horng-Bin; Kuo, Li-Jung; Miyamoto, Naomi; ...

2015-11-30

High-surface-area amidoxime and carboxylic acid grafted polymer adsorbents developed at Oak Ridge National Laboratory were tested for sequestering uranium in a flowing seawater flume system at the PNNL-Marine Sciences Laboratory. FTIR spectra indicate that a KOH conditioning process is necessary to remove the proton from the carboxylic acid and make the sorbent effective for sequestering uranium from seawater. The alkaline conditioning process also converts the amidoxime groups to carboxylate groups in the adsorbent. Both Na 2CO 3 H 2O 2 and hydrochloric acid elution methods can remove ~95% of the uranium sequestered by the adsorbent after 42 days of exposuremore » in real seawater. The Na 2CO 3 H 2O 2 elution method is more selective for uranium than conventional acid elution. Iron and vanadium are the two major transition metals competing with uranium for adsorption to the amidoxime-based adsorbents in real seawater. Tiron (4,5-Dihydroxy-1,3-benzenedisulfonic acid disodium salt, 1 M) can remove iron from the adsorbent very effectively at pH around 7. The coordination between vanadium (V) and amidoxime is also discussed based on our 51V NMR data.« less

Removal of uranium and fluorine from wastewater by double-functional microsphere adsorbent of SA/CMC loaded with calcium and aluminum

NASA Astrophysics Data System (ADS)

Wu, Liping; Lin, Xiaoyan; Zhou, Xingbao; Luo, Xuegang

2016-10-01

A novel dual functional microsphere adsorbent of alginate/carboxymethyl cellulose sodium composite loaded with calcium and aluminum (SA/CMC-Ca-Al) is prepared by an injection device to remove fluoride and uranium, respectively, from fluoro-uranium mixed aqueous solution. Batch experiments are performed at different conditions: pH, temperature, initial concentration and contact time. The results show that the maximum adsorption amount for fluoride is 35.98 mg/g at pH 2.0, 298.15 K concentration 100 mg/L, while that for uranium is 101.76 mg/g at pH 4.0, 298.15 K concentration 100 mg/L. Both of the adsorption process could be well described by Langmuir model. The adsorption kinetic data is fitted well with pseudo-first-order model for uranium and pseudo-second-order model for fluoride. Thermodynamic parameters are also evaluated, indicating that the adsorption of uranium on SA/CMC-Ca-Al is a spontaneous and exothermic process, while the removal of fluoride is non-spontaneous and endothermic process. The mechanism of modification and adsorption process on SA/CMC-Ca-Al is characterized by FT-IR, SEM, EDX and XPS. The results show that Ca (II) and Al (III) are loaded on SA/CMC through ion-exchange of sodium of SA/CMC. The coordination reaction and ion-exchange happen during the adsorption process between SA/CMC-Ca-Al and uranium, fluoride. Results suggest that the SA/CMC-Ca-Al adsorbent has a great potential in removing uranium and fluoride from aqueous solution.

Sedimentology of the lower part of the Upper Triassic Chinle Formation and its relationship to uranium deposits, White Canyon area, southeastern Utah

USGS Publications Warehouse

Dubiel, Russell F.

1983-01-01

Closely spaced measured stratigraphic sections of the lower part of the Late Triassic Chinle Formation in the White Canyon area of southeastern Utah depict a fluvial-deltaic-lacustrine depositional sequence that hosts uranium deposits in basal fluvial sandstones. The basal Shinarump Member consists of predominantly trough-crossbedded, coarse-grained sandstone and minor gray, carbonaceous mudstone and is interpreted as a valley-fill sequence overlain by deposits of a braided stream system. The overlying Monitor Butte Member is composed of cyclic- and foreset-bedded siltstone, sandstone, and mudstone and is interpreted as a succession of low-energy fluvial, deltaic and orqanicrich, lacustrine-marsh sediments. The overlying Moss Back Member is composed of a laterally extensive, coarse- to medium-grained, conglomeratic sandstone and is interpreted as a braided-stream system that flowed north to northwest. The entire sequence was deposited in response to changes in local base level associated with a large lake that lay to the west. Isopachs of lithofacies indicate distinct lacustrine basins and a correspondence between these facies and modern structural synclines. Facies changes and coincidence of isopach thicks suggest that structural synclines were active in the Late Triassic and influenced the pattern of sediment distribution within the basins. Uranium mineralization appears to be related to certain low-energy depositional environments in that uranium is localized in fluvial sandstones that lie beneath organic-rich lacustrine-marsh mudstones and carbonaceous delta-front sediments. The reducing environment preserved in these facies may have played an important role in the localization of uranium.

Patterns and Features of Global Uranium Resources and Production

NASA Astrophysics Data System (ADS)

Wang, Feifei; Song, Zisheng; Cheng, Xianghu; Huanhuan, MA

2017-11-01

With the entry into force of the Paris Agreement, the development of clean and low-carbon energy has become the consensus of the world. Nuclear power is one energy that can be vigorously developed today and in the future. Its sustainable development depends on a sufficient supply of uranium resources. It is of great practical significance to understand the distribution pattern of uranium resources and production. Based on the latest international authoritative reports and data, this paper analysed the distribution of uranium resources, the distribution of resources and production in the world, and the developing tendency in future years. The results show that the distribution of uranium resources is uneven in the world, and the discrepancies between different type deposits is very large. Among them, sandstone-type uranium deposits will become the main type owing to their advantages of wide distribution, minor environmental damage, mature mining technology and high economic benefit.

Method for cleaning bomb-reduced uranium derbies

DOEpatents

Banker, John G.; Wigginton, Hubert L.; Beck, David E.; Holcombe, Cressie E.

1981-01-01

The concentration of carbon in uranium metal ingots induction cast from derbies prepared by the bomb-reduction of uranium tetrafluoride in the presence of magnesium is effectively reduced to less than 100 ppm by removing residual magnesium fluoride from the surface of the derbies prior to casting. This magnesium fluoride is removed from the derbies by immersing them in an alkali metal salt bath which reacts with and decomposes the magnesium fluoride. A water quenching operation followed by a warm nitric acid bath and a water rinse removes the residual salt and reaction products from the derbies.

Method for cleaning bomb-reduced uranium derbies

DOEpatents

Banker, J.G.; Wigginton, H.L.; Beck, D.E.; Holcombe, C.E.

The concentration of carbon in uranium metal ingots induction cast from derbies prepared by the bomb-reduction of uranium tetrafluoride in the presence of magnesium is effectively reduced to less than 100 ppM by removing residual magnesium fluoride from the surface of the derbies prior to casting. This magnesium fluoride is removed from the derbies by immersing them in an alkali metal salt bath which reacts with and decomposes the magnesium fluoride. A water quenching operation followed by a warm nitric acid bath and a water rinse removes the residual salt and reaction products from the derbies.

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

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

Thomas, J.M.; Brock, M.L.; Garland, P.A.

1978-06-01

A compilation of 490 references is presented which is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadrangel name,more » geoformational feature, taxonomic name, and keyword.« less

Paragenesis and Geochronology of the Nopal I Uranium Deposit, Mexico

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

M. Fayek; M. Ren

2007-02-14

Uranium deposits can, by analogy, provide important information on the long-term performance of radioactive waste forms and radioactive waste repositories. Their complex mineralogy and variable elemental and isotopic compositions can provide important information, provided that analyses are obtained on the scale of several micrometers. Here, we present a structural model of the Nopal I deposit as well as petrography at the nanoscale coupled with preliminary U-Th-Pb ages and O isotopic compositions of uranium-rich minerals obtained by Secondary Ion Mass Spectrometry (SIMS). This multi-technique approach promises to provide ''natural system'' data on the corrosion rate of uraninite, the natural analogue ofmore » spent nuclear fuel.« less

Laboratory-scale uranium RF plasma confinement experiments

NASA Technical Reports Server (NTRS)

Roman, W. C.

1976-01-01

An experimental investigation was conducted using 80 kW and 1.2 MW RF induction heater facilities to aid in developing the technology necessary for designing a self-critical fissioning uranium plasma core reactor. Pure uranium hexafluoride (UF6) was injected into argon-confined, steady-state, RF-heated plasmas in different uranium plasma confinement tests to investigate the characteristics of plamas core nuclear reactors. The objectives were: (1) to confine as high a density of uranium vapor as possible within the plasma while simultaneously minimizing the uranium compound wall deposition; (2) to develop and test materials and handling techniques suitable for use with high-temperature, high-pressure gaseous UF6; and (3) to develop complementary diagnostic instrumentation and measurement techniques to characterize the uranium plasma and residue deposited on the test chamber components. In all tests, the plasma was a fluid-mechanically-confined vortex-type contained within a fused-silica cylindrical test chamber. The test chamber peripheral wall was 5.7 cm ID by 10 cm long.

SEPARATION OF URANIUM, PLUTONIUM AND FISSION PRODUCTS FROM NEUTRON- BOMBARDED URANIUM

DOEpatents

Martin, A.E.; Johnson, I.; Burris, L. Jr.; Winsch, I.O.; Feder, H.M.

1962-11-13

A process is given for removing plutonium and/or fission products from uranium fuel. The fuel is dissolved in molten zinc--magnesium (10 to 18% Mg) alloy, more magnesium is added to obtain eutectic composition whereby uranium precipitates, and the uranium are separated from the Plutoniumand fission-product- containing eutectic. (AEC)

DISSOLUTION OF ZIRCONIUM-CONTAINING FUEL ELEMENTS

DOEpatents

Horn, F.L.

1961-12-12

Uranium is recovered from spent uranium fuel elements containing or clad with zirconium. These fuel elements are placed in an anhydrous solution of hydrogen fluoride and nitrogen dioxide. Within this system uranium forms a soluble complex and zirconium forms an insoluble complex. The uranium can then be separated, treated, and removed from solution as uranium hexafluoride. (AEC)

Analysis of borehole geophysical information across a uranium deposit in the Jackson Group, Karnes County, Texas

USGS Publications Warehouse

Daniels, Jeffrey J.; Scott, James Henry; Smith, Bruce D.

1979-01-01

Borehole geophysical studies across a uranium deposit in the Jackson Group, South Texas, show the three geochemical environments often associated with uranium roll-type deposits: an altered (oxidized) zone, an ore zone, and an unaltered (reduced) zone. Mineralogic analysis of the total sulfides contained in the drill core shows only slight changes in the total sulfide content among the three geochemical regimes. However, induced polarization measurements on the core samples indicate that samples obtained from the reduced side of the ore zone are more electrically polarizable than those from the oxidized side of the ore zone, and therefore probably contain more pyrite. Analysis of the clay-size fraction in core samples indicates that montmorillonite is the dominant clay mineral. High resistivity values within the ore zone indicate the presence of calcite cement concentrations that are higher than those seen outside of the ore zone. Between-hole resistivity and induced polarization measurements show the presence of an extensive zone of calcite cement within the ore zone, and electrical polarizable material (such as pyrite) within and on the reduced side of the ore zone. A quantitative analysis of the between-hole resistivity data, using a layered-earth model, and a qualitative analysis of the between-hole induced polarization measurements showed that mineralogic variations among the three geochemical environments were more pronounced than were indicated by the geophysical and geologic well logs. Uranium exploration in the South Texas Coastal Plain area has focused chiefly in three geologic units: the Oakville Sandstone, the Catahoula Tuff, and the Jackson Group. The Oakville Sandstone and the Catahoula Tuff are of Miocene age, and the Jackson Group is of Eocene age (Eargle and others, 1971). Most of the uranium mineralization in these formations is low grade (often less than 0.02 percent U3O8) and occurs in shallow deposits that are found by concentrated exploratory drilling programs. The sporadic occurrence of these deposits makes it desirable to develop borehole geophysical techniques that will help to define the depositional environments of the uranium ore, which is characterized by geochemical changes near the uranium deposits. Geochemical changes are accompanied by changes in the physical characteristics of the rocks that can be detected with borehole geophysical tools. This study is concerned with a uranium deposit within the Jackson Group that is located just east of Karnes City, Tex. Five holes were drilled on this property to obtain borehole geophysical data and cores. The cores were analyzed for mineralogic and electrical properties. The borehole geophysical information at this property included induced polarization, resistivity, gamma-gamma density, neutron-neutron, gamma-ray, caliper, and single-point-resistance logs. Between-hole resistivity and induced polarization measurements were made between hole pairs across the ore deposit and off the ore deposit.

National Uranium Resource Evaluation: Marfa Quadrangle, Texas

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

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

1982-09-01

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

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

NASA Astrophysics Data System (ADS)

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

2011-02-01

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

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

USGS Publications Warehouse

Nash, J. Thomas

1977-01-01

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

Uranium deposits in the Eureka Gulch area, Central City district, Gilpin County, Colorado

USGS Publications Warehouse

Sims, P.K.; Osterwald, F.W.; Tooker, E.W.

1954-01-01

The Eureka Gulch area of the Central City district, Gilpin County, Colo., was mined for ores of gold, silver, copper, lead, and zinc; but there has been little mining activity in the area since World War I. Between 1951 and 1953 nine radioactive mine dumps were discovered in the area by the U.S. Geological Survey and by prospectors. the importance of the discoveries has not been determined as all but one of the mines are inaccessible, but the distribution, quantity, and grade of the radioactive materials found on the mine dumps indicate that the area is worth of additional exploration as a possible source of uranium ore. The uranium ans other metals are in and near steeply dipping mesothermal veins of Laramide age intrusive rocks. Pitchblende is present in at least four veins, and metatorbernite, associated at places with kosolite, is found along two veins for a linear distance of about 700 feet. The pitchblends and metatorbernite appear to be mutually exclusive and seem to occur in different veins. Colloform grains of pitchblende were deposited in the vein essentially contemporaneously with pyrite. The pitchblende is earlier in the sequence of deposition than galena and sphalerite. The metatorbernite replaces altered biotite-quartz-plagioclase gneiss and altered amphibolite, and to a lesser extent forms coatings on fractures in these rocks adjacent to the veins; the kasolite fills vugs in highly altered material and in altered wall rocks. Much of the pitchblende found on the dumps has been partly leached subsequent to mining and is out of equilibrium. Selected samples of metatorbernite-bearing rock from one mine dump contain as much as 6.11 percent uranium. The pitchblende is a primary vein mineral deposited from uranium-bearing hydrothermal solutions. The metatorbernite probably formed by oxidation, solution, and transportation of uranium from primary pitchblende, but it may be a primary mineral deposited directly from fluids of different composition from these that deposited pitchblende.

Thermodynamic properties of selected uranium compounds and aqueous species at 298.15 K and 1 bar and at higher temperatures; preliminary models for the origin of coffinite deposits

USGS Publications Warehouse

Hemingway, B.S.

1982-01-01

Thermodynamic values for 110 uranium-bearing phases and 28 aqueous uranium solution species (298.15 K and l bar) are tabulated based upon evaluated experimental data (largely from calorimetric experiments) and estimated values. Molar volume data are given for most of the solid phases. Thermodynamic values for 16 uranium-bearing phases are presented for higher temperatures in the form of and as a supplement to U.S. Geological Survey Bulletin 1452 (Robie et al., 1979). The internal consistency of the thermodynamic values reported herein is dependent upon the reliability of the experimental results for several uranium phases that have been used as secondary calorimetric reference phases. The data for the reference phases and for those phases evaluated with respect to the secondary reference phases are discussed. A preliminary model for coffinite formation has been proposed together with an estimate of the free energy of formation of coffinite. Free energy values are estimated for several other uranium-bearing silicate phases that have been reported as secondary uranium phases associated with uranium ore deposits and that could be expected to develop wherever uranium is leached by groundwaters.

Interim Report: Field Demonstration Of Permeable Reactive Barriers To Remove Dissolved Uranium From Groundwater, Fry Canyon, Utah

EPA Pesticide Factsheets

The Fry Canyon site in southeastern Utah was selected in 1996 as a long-term field demonstration site to assess the performance of selected permeable reactive barriers for the removal of uranium (U) from groundwater.

Reconnaissance for radioactive materials in northeastern United States during 1952

USGS Publications Warehouse

McKeown, Francis A.; Klemic, Harry

1953-01-01

Reconnaissance for radioactive materials was made in parts of Maine, New York, New Jersey, and Pennsylvania. The primary objective was to examine the iron ore deposits and associated rocks in the Adirondack Mountains of New York and the Highlands of New Jersey. In addition, several deposits known or reported to contain radioactive minerals were examined to delimit their extent. Most of the deposits examined are not significant as possible sources of radioactive elements and the data pertaining to them are summarized in table form. Deposits that do warrant more description than can be given in table form are: Benson Mines, St. Lawrence County, N. Y.; Rutgers mine, Clinton County, N. Y.; Mineville Mines, Essex County, N. Y.l Canfield phosphate mine, Morris County, N. J.; Mullgan quarry, Hunterdon County, N. J.; and the Chestnut Hill-Marble Mountain area, Pennsylvania and New Jersey. The Old Bed in the Mineville district is the only deposit that may be economically significant. Apatite from Old Bed ore contains as much as 4.9 percent total rare earth. 0.04 percent thorium, and 0.018 percent uranium. Magnetite ore at the Rutgers mine contains radioactive zircon and apatite. Radioactivity measurements of outcrops and dump material show that the ore contains from 0.005 to 0.010 percent equivalent uranium. One sample of lean magnetite ore contains 0.006 percent equivalent uranium. Garnet-rich zones in the Benson Mines magnetite deposit contain as much as 0.017 equivalent uranium. Most of the rock and ore, however, contains about 0.005 percent equivalent uranium. Available data indicate that the garnet-rich zones are enriched in radioactive allanite. A shear zone in the Kittatinny limestone of Cambrian age at the Mulligan quarry contains uraniferous material. Radioactivity anomalies elsewhere in the quarry and in adjacent fields indicate that there may be other uraniferous shear zones. Assays of samples and measurements of outcrop radioactivity indicate that the uranium content of these zones is low; samples contain from 0.008 to 0.068 percent equivalent uranium. The anomalies, however, may indicate greater concentrations of uranium below surficial leached zones. The Chestnut Hill-Marble Mountain area contains radioactivity anomalies for about 2 miles along the strike of the contact of pre-Cambrian Pickering gneiss and Franklin limestone formations. In places this contact is injected with pegmatite, which probably was the source of the radioelements. The most favorable area for further study is at Marble Mountain, where a nearly continuous anomaly extends for about 1500 feet. Samples from part of this area contain as much as 0.044 percent equivalent uranium and 0.005 percent uranium. Radioactive hematite and florencite, in which thorium may have substituted for cerium, are the only radioactive minerals observed in the Marble Mountain area.

Uranium-series dated authigenic carbonates and Acheulian sites in southern Egypt

NASA Technical Reports Server (NTRS)

Szabo, B. J.; Mchugh, W. P.; Schaber, G. G.; Breed, C. S.; Haynes, C. V., Jr.

1989-01-01

Field investigations of aggraded paleovalleys, which were identified in southern Egypt using SIR, are discussed. Acheulian artifacts were found in authigenic carbonate deposites along the edges of the paleovalleys. Uranium series dating of 25 carbonate samples shows that widespread carbonate deposition in the area occurred about 45, 141, and 212 thousand years ago. Analysis of the carbonate suggests that the deposition may be related to late Pleistocene humid climates that facilitated human settlement in the region.

Role of U(VI) Reduction by Geobacter species

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

Lovely, Derrick

2008-12-23

Previous work had suggested that Acholeplasma palmae has a higher capacity for uranium sorption than other bacteria studied. Sorption studies were performed with cells in suspension in various solutions containing uranium, and results were used to generate uranium-biosorption isotherms. Results from this study showed that the U(VI) sorption capacity of G. uraniireducens was relatively similar in simple solutions, such as sodium chloride or bicarbonate. However, this ability to sorb uranium significantly decreased in groundwater. This suggested that certain chemicals present in the groundwater were inhibiting the ability of cell components of Geobacter to adsorb uranium. It was hypothesized that uraniummore » removal would also be diminished in the bicarbonate solution. However, this did not seem to be the case, as uranium was as easily removed in the bicarbonate solution as in the sodium chloride solution.« less

SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

DOEpatents

Boyd, G.E.; Adamson, A.W.; Schubert, J.; Russell, E.R.

1958-10-01

A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This process provides a convenient and efficient means for isolating plutonium.

A study of radioactivity in modern stream gravels and its possible application as a prospecting method

USGS Publications Warehouse

Chew, Randall T.

1955-01-01

Traverses along some streams of the Colorado Plateau in areas known to contain minable uranium deposits show that anomalous radiation in the stream gravels can be detected with a suitable counter downstream from the deposits. The amount of radiation is influenced by the size of the uranium deposit, the size of the drainage area of the stream, the grain size of the sediments, and the lithology of the rocks over which the stream flows. The spacing of the stations where readings are taken is controlled by the size of the stream, and special readings are also taken directly downstream from important tributaries. An anomaly is empirically defined as a 10 percent rise over background. Radioactive material from large uranium deposits has been detected as much as 1 mile downstream. Radioactive material from smaller deposits is detachable over shorter distances. The method is slow but appears to be a useful prospecting tool under restricted conditions.

Geological and geochemical aspects of uranium deposits: a selected, annotated bibliography. Vol. 2, Rev. 1. [490 references

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

Thomas, J.M.; Brock, M.L.; Garland, P.A.

1979-07-01

This bibliography, a compilation of 490 references, is the second in a series compiled from the National Uranium Resource Evaluation (NURE) Bibliographic Data Base. This data base is one of six data bases created by the Ecological Sciences Information Center, Oak Ridge National Laboratory, for the Grand Junction Office of the Department of Energy. Major emphasis for this volume has been placed on uranium geology, encompassing deposition, genesis of ore deposits, and ore controls; and prospecting techniques, including geochemistry and aerial reconnaissance. The following indexes are provided to aid the user in locating references of interest: author, geographic location, quadranglemore » name, geoformational feature, taxonomic name, and keyword.« less

Removal of toxic uranium from synthetic nuclear power reactor effluents using uranyl ion imprinted polymer particles.

PubMed

Preetha, Chandrika Ravindran; Gladis, Joseph Mary; Rao, Talasila Prasada; Venkateswaran, Gopala

2006-05-01

Major quantities of uranium find use as nuclear fuel in nuclear power reactors. In view of the extreme toxicity of uranium and consequent stringent limits fixed by WHO and various national governments, it is essential to remove uranium from nuclear power reactor effluents before discharge into environment. Ion imprinted polymer (IIP) materials have traditionally been used for the recovery of uranium from dilute aqueous solutions prior to detection or from seawater. We now describe the use of IIP materials for selective removal of uranium from a typical synthetic nuclear power reactor effluent. The IIP materials were prepared for uranyl ion (imprint ion) by forming binary salicylaldoxime (SALO) or 4-vinylpyridine (VP) or ternary SALO-VP complexes in 2-methoxyethanol (porogen) and copolymerizing in the presence of styrene (monomer), divinylbenzene (cross-linking monomer), and 2,2'-azobisisobutyronitrile (initiator). The resulting materials were then ground and sieved to obtain unleached polymer particles. Leached IIP particles were obtained by leaching the imprint ions with 6.0 M HCl. Control polymer particles were also prepared analogously without the imprint ion. The IIP particles obtained with ternary complex alone gave quantitative removal of uranyl ion in the pH range 3.5-5.0 with as low as 0.08 g. The retention capacity of uranyl IIP particles was found to be 98.50 mg/g of polymer. The present study successfully demonstrates the feasibility of removing uranyl ions selectively in the range 5 microg - 300 mg present in 500 mL of synthetic nuclear power reactor effluent containing a host of other inorganic species.

World distribution of uranium deposits

USGS Publications Warehouse

Fairclough, M. C.; Irvine, J. A.; Katona, L. F.; Simmon, W. L.; Bruneton, P.; Mihalasky, Mark J.; Cuney, M.; Aranha, M.; Pylypenko, O.; Poliakovska, K.

2018-01-01

Deposit data derived from IAEA UDEPO (http://infcis.iaea.org/UDEPO/About.cshtml) database with assistance from P. Bruneton (France) and M. Mihalasky (U.S.A.). The map is an updated companion to "World Distribution of Uranium Deposits (UDEPO) with Uranium Deposit Classification, IAEA Tech-Doc-1629". Geology was derived from L.B. Chorlton, Generalized Geology of the World, Geological Survey of Canada, Open File 5529 , 2007. Map production by M.C. Fairclough (IAEA), J.A. Irvine (Austrailia), L.F. Katona (Australia) and W.L. Slimmon (Canada). World Distribution of Uranium Deposits, International Atomic Energy Agency, Vienna, Austria. Cartographic Assistance was supplied by the Geological Survey of South Australia, the Saskatchewan Geological Survey and United States Geological Survey to the IAEA. Coastlines, drainage, and country boundaries were obtained from ArcMap, 1:25 000 000 scale, and are copyrighted data containing the intellectual property of Environmental Systems Research Institute (ESRI). The use of particular designations of countries or territories does not imply any judgment by the publisher, the IAEA, as to the legal status of such countries or territories, of their authorities and institutions or of the delimitation of their boundaries. Any revisions or additional geological information known to the user would be welcomed by the International Atomic Energy Agency and the Geological Survey of Canada.

METHOD FOR RECOVERING URANIUM FROM OILS

DOEpatents

Gooch, L.H.

1959-07-14

A method is presented for recovering uranium from hydrocarbon oils, wherein the uranium is principally present as UF/sub 4/. According to the invention, substantially complete removal of the uranium from the hydrocarbon oil may be effected by intimately mixing one part of acetone to about 2 to 12 parts of the hydrocarbon oil containing uranium and separating the resulting cake of uranium from the resulting mixture. The uranium in the cake may be readily recovered by burning to the oxide.

Comparison of amino acid racemization geochronometry with lithostratigraphy, biostratigraphy, uranium-series coral dating, and magnetostratigraphy in the Atlantic Coastal Plain of the southeastern United States

USGS Publications Warehouse

McCartan, L.; Owens, J.P.; Blackwelder, B. W.; Szabo, B. J.; Belknap, D.F.; Kriausakul, N.; Mitterer, R.M.; Wehmiller, J.F.

1982-01-01

The results of an integrated study comprising litho- and biostratigraphic investigations, uranium-series coral dating, amino acid racemization in molluscs, and paleomagnetic measurements are compared to ascertain relative and absolute ages of Pleistocene deposits of the Atlantic Coastal Plain in North and South Carolina. Four depositional events are inferred for South Carolina and two for North Carolina by all methods. The data suggest that there are four Pleistocene units containing corals that have been dated at about 100,000 yr, 200,000 yr, 450,000 yr, and over 1,000,000 yr. Some conflicts exist between the different methods regarding the correlation of the younger of these depositional events between Charleston and Myrtle Beach. Lack of good uranium-series dates for the younger material at Myrtle Beach makes the correlation with the deposits at Charleston more difficult. ?? 1982.

Molecular marker and stable carbon isotope analyses of carbonaceous Ambassador uranium ores of Mulga Rock in Western Australia

NASA Astrophysics Data System (ADS)

Jaraula, C.; Schwark, L.; Moreau, X.; Grice, K.; Bagas, L.

2013-12-01

Mulga Rock is a multi-element deposit containing uranium hosted by Eocene peats and lignites deposited in inset valleys incised into Permian rocks of the Gunbarrel Basin and Precambrian rocks of the Yilgarn Craton and Albany-Fraser Orogen. Uranium readily adsorbs onto minerals or phytoclasts to form organo-uranyl complexes. This is important in pre-concentrating uranium in this relatively young ore deposit with rare uraninite [UO2] and coffinite [U(SiO4)1-x(OH)4x], more commonly amorphous and sub-micron uranium-bearing particulates. Organic geochemical and compound-specific stable carbon isotope analyses were conducted to identify possible associations of molecular markers with uranium accumulation and to recognize effect(s) of ionizing radiation on molecular markers. Samples were collected from the Ambassador deposit containing low (<200 ppm) to high (>2000 ppm) uranium concentrations. The bulk rock C/N ratios of 82 to 153, Rock-Eval pyrolysis yields of 316 to 577 mg hydrocarbon/g TOC (Hydrogen Index, HI) and 70 to 102 mg CO2/g TOC (Oxygen Index, OI) are consistent with a terrigenous and predominantly vascular plant OM source deposited in a complex shallow water system, ranging from lacustrine to deltaic, swampy wetland and even shallow lake settings as proposed by previous workers. Organic solvent extracts were separated into saturated hydrocarbon, aromatic hydrocarbon, ketone, and a combined free fatty acid and alcohol fraction. The molecular profiles appear to vary with uranium concentration. In samples with relatively low uranium concentrations, long-chain n-alkanes, alcohols and fatty acids derived from epicuticular plant waxes dominate. The n-alkane distributions (C27 to C31) reveal an odd/even preference (Carbon Preference Index, CPI=1.5) indicative of extant lipids. Average δ13C of -27 to -29 ‰ for long-chain n-alkanes is consistent with a predominant C3 plant source. Samples with relatively higher uranium concentrations contain mostly intermediate-length n-alkanes, ketones, alcohols, and fatty acids (C20 to C24) with no preferential distribution (CPI~1). Intermediate length n-alkanes have modest carbon isotope enrichment compared to long-chain n-alkanes. These shorter-chain hydrocarbons are interpreted to represent alteration products. The diversity and relative abundance of ketones in highly mineralised Mulga Rock peats and lignites are not consistent with aerobic and diagenetic degradation of terrigenous OM in oxic environments. Moreover, molecular changes cannot be associated with thermal breakdown due to the low maturity of the deposits. It is possible that the association of high uranium concentrations and potential radiolysis resulted in the oxidation of alcohol functional groups into aldehydes and ketones and breakdown of highly aliphatic macromolecules (i.e. spores, pollen, cuticles, and algal cysts). These phytoclasts are usually considered to be recalcitrant as they evolved to withstand chemical and physical degradation. Previous petrographic analyses show that spores, pollen and wood fragments are preferentially enriched in uranium. Their molecular compositions are feasible sources of short- to intermediate-length n-alkanes that dominate the mineralised peats and lignites.

Mechanism of uranium (VI) removal by two anaerobic bacterial communities.

PubMed

Martins, Mónica; Faleiro, Maria Leonor; da Costa, Ana M Rosa; Chaves, Sandra; Tenreiro, Rogério; Matos, António Pedro; Costa, Maria Clara

2010-12-15

The mechanism of uranium (VI) removal by two anaerobic bacterial consortia, recovered from an uncontaminated site (consortium A) and other from an uranium mine (consortium U), was investigated. The highest efficiency of U (VI) removal by both consortia (97%) occurred at room temperature and at pH 7.2. Furthermore, it was found that U (VI) removal by consortium A occurred by enzymatic reduction and bioaccumulation, while the enzymatic process was the only mechanism involved in metal removal by consortium U. FTIR analysis suggested that after U (VI) reduction, U (IV) could be bound to carboxyl, phosphate and amide groups of bacterial cells. Phylogenetic analysis of 16S rRNA showed that community A was mainly composed by bacteria closely related to Sporotalea genus and Rhodocyclaceae family, while community U was mainly composed by bacteria related to Clostridium genus and Rhodocyclaceae family. Copyright © 2010 Elsevier B.V. All rights reserved.

URANIUM REMOVAL FROM DRINKING WATER USING A SMALL FULL-SCALE SYSTEM

EPA Science Inventory

This report presents background and history of water quality, the basis for design and nine months of actual operating data for a small, full-scale strong-base ion exchange system that is used to remove uranium from a water supply serving a school in Jefferson County, CO. Informa...

Uranium deposits in Grant County, New Mexico

USGS Publications Warehouse

Granger, Harry C.; Bauer, Herman L.; Lovering, Tom G.; Gillerman, Elliot

1952-01-01

The known uranium deposits of Grant county, N. Mex., are principally in the White Signal and Black Hawk districts. Both districts are within a northwesterly-trending belt of pre-Cambrian rocks, composed chiefly of granite with included gneisses, schists, and quartzites. Younger dikes and stocks intrude the pre-Cambrian complex. The White Signal district is on the southeast flanks of the Burro Mountains; the Black Hawk district is about 18 miles northwest of the town of White Signal. In the White Signal district the seconday uranium phosphates--autunite and torbernite--occur as fracture coatings and disseminations in oxidized parts of quartz-pyrite veins, and in the adjacent mafic dikes and granites; uraniferous limonite is common locally. Most of the known uraniferous deposits are less that 50 feet in their greatest dimension. The most promising deposits in the district are on the Merry Widow and Blue Jay claims. The richest sample taken from the Merry Widow mine contained more than 2 percent uranium and a sample from the Blue Jay property contained as much as 0.11 percent; samples from the other properties were of lower grade. In the Black Hawk district pitchblende is associated with nickel, silver, and cobalt minerals in fissure veins. The most promising properties in the Black Hawk district are the Black Hawk, Alhambra, and Rose mines. No uranium analyses from this district were available in 1951. There are no known minable reserves of uranium ore in either district, although there is some vein material at the Merry Widow mine of ore grade, if a market were available in the region.

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

EPA Science Inventory

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

Remediation of subsurface and groundwater contamination with uranium from fuel fabrication facilities at Hanau (Germany)

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

Nitzsche, Olaf; Thierfeldt, Stefan; Hummel, Lothar

2013-07-01

This paper presents aspects of site decommissioning and clearance of a former fuel fabrication facility (development and production of fuel assemblies for research reactors and HTR) at Hanau (Germany). The main pathways for environmental contamination were deposition on soil surface and topsoil and pollution of deep soil and the aquifer by waste water channel leakage. Soil excavation could be done by classical excavator techniques. An effective removal of material from the saturated zone was possible by using advanced drilling techniques. A large amount of demolished building structure and excavated soil had to be classified. Therefore the use of conveyor detectormore » was necessary. Nearly 100000 Mg of material (excavated soil and demolished building material) were disposed of at an underground mine. A remaining volume of 700 m{sup 3} was classified as radioactive waste. Site clearance started in 2006. Groundwater remediation and monitoring is still ongoing, but has already provided excellent results by reducing the remaining Uranium considerably. (authors)« less

Uranium production in Romania

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

NONE

1994-12-01

This article reviews uranium production in Romania. Geological aspects of the country are discussed, and known uranium deposits are noted. Uranium mining and milling activities are also covered. Utilization of Romania`s uranium production industry will primarily be to supply the country`s nuclear power program, and with the present adequate supplies and the operation of their recently revamped fuel production facility, Romania should be self-reliant in the front end of the nuclear fuel cycle.

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

USGS Publications Warehouse

Finch, Warren Irvin

1954-01-01

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

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

USGS Publications Warehouse

Finch, Warren Irvin

1953-01-01

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

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

USGS Publications Warehouse

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

1987-01-01

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

Linearity assumption in soil-to-plant transfer factors of natural uranium and radium in Helianthus annuus L.

PubMed

Rodríguez, P Blanco; Tomé, F Vera; Fernández, M Pérez; Lozano, J C

2006-05-15

The linearity assumption of the validation of soil-to-plant transfer factors of natural uranium and (226)Ra was tested using Helianthus annuus L. (sunflower) grown in a hydroponic medium. Transfer of natural uranium and (226)Ra was tested in both the aerial fraction of plants and in the overall seedlings (roots and shoots). The results show that the linearity assumption can be considered valid in the hydroponic growth of sunflowers for the radionuclides studied. The ability of sunflowers to translocate uranium and (226)Ra was also investigated, as well as the feasibility of using sunflower plants to remove uranium and radium from contaminated water, and by extension, their potential for phytoextraction. In this sense, the removal percentages obtained for natural uranium and (226)Ra were 24% and 42%, respectively. Practically all the uranium is accumulated in the roots. However, 86% of the (226)Ra activity concentration in roots was translocated to the aerial part.

Preparation and biosorption evaluation of Bacillus subtilis/alginate–chitosan microcapsule

PubMed Central

Tong, Ke

2017-01-01

The aim of this study was to assess the effect of alginate–chitosan microcapsule on viability characteristics of Bacillus subtilis and the ability of B. subtilis/alginate–chitosan microcapsule to remove uranium ion from aqueous solution. The effects of particle size, chitosan molecular weight and inoculum density on viability characteristics were studied using alginate–chitosan microcapsule-immobilized B. subtilis experiments. In addition, the effects of pH, immobilized spherule dosage, temperature, initial uranium ion concentration and contact time on removal of uranium ion were studied using batch adsorption experiments. The results showed that alginate–chitosan microcapsule significantly improved the viability characteristics of B. subtilis and that B. subtilis/alginate–chitosan microcapsule strongly promoted uranium ion absorption. Moreover, the optimum values of pH was 6; immobilized spherule dosage was 3.5; temperature was 20°C; initial uranium ion concentration was 150 mg/L; contact time was 3 h of uranium ion absorption and the maximum adsorption capacity of uranium ion was 376.64 mg/g. PMID:28223783

Elution of Uranium and Transition Metals from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

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

Pan, Horng-Bin; Kuo, Li-Jung; Wai, Chien M.

2015-11-30

High-surface-area amidoxime and carboxylic acid grafted polymer adsorbents developed at Oak Ridge National Laboratory were tested for sequestering uranium in a flowing seawater flume system at the PNNL-Marine Sciences Laboratory. FTIR spectra indicate that a KOH conditioning process is necessary to remove the proton from the carboxylic acid and make the sorbent effective for sequestering uranium from seawater. The alkaline conditioning process also converts the amidoxime groups to carboxylate groups in the adsorbent. Both Na 2CO 3-H 2O 2 and hydrochloric acid elution methods can remove ~95% of the uranium sequestered by the adsorbent after 42 days of exposure inmore » real seawater. The Na 2CO 3-H 2O 2 elution method is more selective for uranium than conventional acid elution. Iron and vanadium are the two major transition metals competing with uranium for adsorption to the amidoxime-based adsorbents in real seawater.« less

Uranium and radon in ground water in the lower Illinois River basin

USGS Publications Warehouse

Morrow, William S.

2001-01-01

Uranium and radon are present in ground water throughout the United States, along with other naturally occurring radionuclides. The occurrence and distribution of uranium and radon are of concern because these radionuclides are carcinogens that can be ingested through drinking water. As part of the U.S. Geological Survey (USGS) National Water-Quality Assessment (NAWQA) program, water samples were collected and analyzed for uranium and radon from 117 wells in four aquifers in the lower Illinois River Basin (LIRB) from 1996 to 1997. The aquifers were the shallow glacial drift deposits of the Bloomington Ridged Plain (BRP) not overlying a buried bedrock valley (BRP N/O BV), shallow glacial drift deposits of the BRP overlying the Mahomet Buried Bedrock Valley (BRP O/L MBBV), shallow glacial drift deposits of the Galesburg/Springfield Plain not overlying a buried bedrock valley (GSP N/O BV), and the deep glacial drift deposits of the Mahomet Buried Bedrock Valley (MBBV). Uranium was detected in water samples from all aquifers except the MBBV and ranged in concentration from less than 1 microgram per liter ( ? g/L) to 17 ? g/L. Uranium concentrations did not exceed 20 ? g/L, the proposed U.S. Environmental Protection Agency (USEPA) Maximum Contaminant Level (MCL) at the time of sampling (1996?97). The current (2001) promulgated MCL is 30 ? g/L (U.S. Environmental Protection Agency, 2000). The highest median uranium concentration (2.0 ? g/L) among the four aquifers was in the BRP N/O BV. Uranium most often occurred in oxidizing and sulfate-rich water. Radon was detected in water samples from all aquifers in the LIRB. Radon concentrations in all aquifers ranged from less than 80 picocuries per liter (pCi/L) to 1,300 pCi/L. Of 117 samples, radon concentrations exceeded 300 pCi/L (the proposed USEPA MCL) in 34 percent of the samples. Radon concentrations exceeded 300 pCi/L in more than one-half of the samples from the GSP N/O BV and the BRP O/L MBBV. No sample exceeded the proposed Alternative Maximum Contaminant Level (AMCL) of 4,000 pCi/L. Concentrations of uranium and radon were not correlated.

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

USGS Publications Warehouse

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

1952-01-01

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

Potential of a New Technique for Remote Sensing of Hydrocarbon Accumulations and Blind Uranium Deposits: Buried Lif Thermoluminescence Dosimeters

NASA Technical Reports Server (NTRS)

Siegel, F. R.; Vaz, J. E.; Lindholm, R. C.

1982-01-01

Buried thermoluminescence dosimeters may be useful in remote sensing of petroleum and natural gas accumulations and blind uranium deposits. They act as integrating detectors that smooth out the effects of environmental variations that affect other measuring systems and result in irregularities and poor repeatability in measurements made during gas and radiometric surveys.

Indian Creek uranium prospects, Beaver County, Utah

USGS Publications Warehouse

Wyant, Donald G.; Stugard, Frederick

1951-01-01

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

PROCESS FOR SEPARATING URANIUM FISSION PRODUCTS

DOEpatents

Spedding, F.H.; Butler, T.A.; Johns, I.B.

1959-03-10

The removal of fission products such as strontium, barium, cesium, rubidium, or iodine from neutronirradiated uranium is described. Uranium halide or elemental halogen is added to melted irradiated uranium to convert the fission products to either more volatile compositions which vaporize from the melt or to higher melting point compositions which separate as solids.

Depleted Uranium | RadTown USA | US EPA

EPA Pesticide Factsheets

2018-01-12

Depleted uranium is the material left after most of the highly radioactive uranium-235 is removed from uranium ore for nuclear power and weapons. DU is used for tank armor, armor-piercing bullets and as weights to help balance aircraft. DU is both a toxic chemical and radiation health hazard when inside the body.

Uniform deposition of uranium hexafluoride (UF6): Standardized mass deposits and controlled isotopic ratios using a thermal fluorination method.

PubMed

McNamara, Bruce K; O'Hara, Matthew J; Casella, Andrew M; Carter, Jennifer C; Addleman, R Shane; MacFarlan, Paul J

2016-07-01

We report a convenient method for the generation of volatile uranium hexafluoride (UF6) from solid uranium oxides and other U compounds, followed by uniform deposition of low levels of UF6 onto sampling coupons. Under laminar flow conditions, UF6 is shown to interact with surfaces within a fixed reactor geometry to a highly predictable degree. We demonstrate the preparation of U deposits that range between approximately 0.01 and 500ngcm(-2). The data suggest the method can be extended to creating depositions at the sub-picogramcm(-2) level. The isotopic composition of the deposits can be customized by selection of the U source materials and we demonstrate a layering technique whereby two U solids, each with a different isotopic composition, are employed to form successive layers of UF6 on a surface. The result is an ultra-thin deposit that bears an isotopic signature that is a composite of the two U sources. The reported deposition method has direct application to the development of unique analytical standards for nuclear safeguards and forensics. Further, the method allows access to very low atomic or molecular coverages of surfaces. Copyright © 2016 Elsevier B.V. All rights reserved.

SEPARATION OF PLUTONIUM FROM URANIUM AND FISSION PRODUCTS

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

Boyd, G.E.; Adamson, A.W.; Schubert, J.

A chromatographic adsorption process is presented for the separation of plutonium from other fission products formed by the irradiation of uranium. The plutonium and the lighter element fission products are adsorbed on a sulfonated phenol-formaldehyde resin bed from a nitric acid solution containing the dissolved uranium. Successive washes of sulfuric, phosphoric, and nitric acids remove the bulk of the fission products, then an eluate of dilute phosphoric and nitric acids removes the remaining plutonium and fission products. The plutonium is selectively removed by passing this solution through zirconium phosphate, from which the plutonium is dissolved with nitric acid. This processmore » provides a convenient and efficient means for isolating plutonium.« less

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

USGS Publications Warehouse

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

1952-01-01

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

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

USGS Publications Warehouse

Trites, Albert F.; Chew, Randall T.

1954-01-01

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

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

USGS Publications Warehouse

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.

Exploration for uranium deposits in the Atkinson Mesa area, Montrose County, Colorado

USGS Publications Warehouse

Brew, Daniel Allen

1954-01-01

The U.S. Geological Survey explored the Atkinson Mesa area for uranium- and vanadium-bearing deposits from July 2, 1951, to June 18, 1953, with 397 diamond-drill holes that totaled 261,251 feet. Sedimentary rocks of Mesozoic age are exposed in the Atkinson Mesa area. They are: the Brushy Basin member of the Upper Jurassic Morrison formation, the Lower Cretaceous Burro Canyon formation, and the Upper and Lower Cretaceous Dakota sandstone. All of the large uranium-vanadium deposits discovered by Geological Survey drilling are in a series of sandstone lenses in the upper part of the Salt Wash member of the Jurassic Morrison formation. The deposits are mainly tabular and blanket-like, but some elongate pod-shaped masses, locally called "rolls" may be present. The mineralized material consists of sandstone impregnated with a uranium mineral which is probably coffinite, spme carnotite, and vanadium minerals, thought to be mainly corvusite and montroseite. In addition,, some mudstone and carbonaceous material is similarly impregnated. Near masses of mineralized material the sandstone is light gray or light brown, is generally over 40 feet thick, and usually contains some carbonaceous material and abundant disseminated pyrite or limonite stain. Similarly, the mudstone in contact with the ore-bearing sandstone near bodies of mineralized rock is commonly blue gray, as compared to its dominant red color away from ore deposits. Presence and degree of these features are useful guides in exploring for new deposits.

Removal of uranium from soil sample digests for ICP-OES analysis of trace metals

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

Foust, R.D. Jr.; Bidabad, M.

1996-10-01

An analytical procedure has been developed to quantitatively remove uranium from soil sample digests, permitting ICP-OES analysis of trace metals. The procedure involves digesting a soil sample with standard procedures (EPA SW-846, Method 3050), and passing the sample digestate through commercially available resin (U/TEVA{sm_bullet}Spec, Eichrom Industries, Inc.) containing diarryl amylphosphonate as the stationary phase. Quantitative removal of uranium was achieved with soil samples containing up to 60% uranium, and percent recoveries averaged better than 85% for 9 of the 10 metals evaluated (Ag, As, Cd. Cr, Cu, Ni, Pb, Se and Tl). The U/TEVA{sm_bullet}Spec column was regenerated by washing withmore » 200 mL of a 0.01 M oxalic acid/0.02 M nitric acid solution, permitting re-use of the column. GFAAS analysis of a sample spiked with 56.5% uranium, after treatment of the digestate with a U/TEVA{sm_bullet}Spec resin column, resulted in percent recoveries of 97% or better for all target metals.« less

Uranium(VI) interactions with mackinawite in the presence and absence of bicarbonate and oxygen.

PubMed

Gallegos, Tanya J; Fuller, Christopher C; Webb, Samuel M; Betterton, William

2013-07-02

Mackinawite, Fe(II)S, samples loaded with uranium (10(-5), 10(-4), and 10(-3) mol U/g FeS) at pH 5, 7, and 9, were characterized using X-ray absorption spectroscopy and X-ray diffraction to determine the effects of pH, bicarbonate, and oxidation on uptake. Under anoxic conditions, a 5 g/L suspension of mackinawite lowered 5 × 10(-5) M uranium(VI) to below 30 ppb (1.26 × 10(-7) M) U. Between 82 and 88% of the uranium removed from solution by mackinawite was U(IV) and was nearly completely reduced to U(IV) when 0.012 M bicarbonate was added. Near-neighbor coordination consisting of uranium-oxygen and uranium-uranium distances indicates the formation of uraninite in the presence and absence of bicarbonate, suggesting reductive precipitation as the dominant removal mechanism. Following equilibration in air, mackinawite was oxidized to mainly goethite and sulfur and about 76% of U(IV) was reoxidized to U(VI) with coordination of uranium to axial and equatorial oxygen, similar to uranyl. Additionally, uranium-iron distances, typical of coprecipitation of uranium with iron oxides, and uranium-sulfur distances indicating bidentate coordination of U(VI) to sulfate were evident. The affinity of mackinawite and its oxidation products for U(VI) provides impetus for further study of mackinawite as a potential reactive medium for remediation of uranium-contaminated water.

Successful remediation of four uranium calibration pits at Technical Area II, Sandia National Laboratories, Albuquerque, New Mexico, USA

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

Conway, R.; Wade, M.; Tharp, T.

1994-12-31

The first remediation of an Environmental Restoration (ER) Project site at Sandia National Laboratories (SNL) was successfully conducted in May and June 1994 at Technical Area II. The removal action involved four Uranium Calibration Pits (UCPs) filled with radioactive or hazardous materials. The concrete culvert pits were used to test and calibrate borehole radiometric logging tools for uranium exploration. The removal action consisted of excavating and containerizing the pit contents and contaminated soil beneath the culverts, removing the four culverts, and backfilling the excavation. Each UCP removal had unique complexities. Sixty 208-L drums of solid radioactive waste and eight 208-Lmore » drums of liquid hazardous waste were generated during the VCM. Two of the concrete culverts will be disposed as radioactive waste and two as solid waste. Uranium-238 was detected in UCP-2 ore material at 746 pci/g, and at 59 pci/g in UCP-1 silica sand. UCP-4 was empty; sludge from UCP-3 contained 122 mg/L (ppm) chromium.« less

Selective removal of uranium ions from contaminated waters using modified-X nanozeolite.

PubMed

Shakur, H R; Rezaee Ebrahim Saraee, Kh; Abdi, M R; Azimi, G

2016-12-01

In order to efficiently remove of uranium anionic species (which are the most dominant species of uranium in natural water at neutral pH) from contaminated waters, nano-NaX zeolite was synthesized and then modified using various divalent cations (Mg 2+ , Ca 2+ , Mn 2+ ) and ZnO nanoparticles (from 1.7 to 10.3wt%). Different characterization techniques of XRF, XRD, FE-SEM, TEM, FT-IR, and AAS were used to characterize the final synthesized absorbents. Sorption experiments by batch technique were done to study the effect of solid-liquid ratio, initial uranium concentration, contact time and temperature under neutral condition of pH and presence of all anions and cations which are available in the waters. Results showed that although nano-NaX zeolite due to its negative framework charge had a low sorption capacity for adsorption of uranium anionic species, but modification of parent nano-NaX zeolite with ZnO nanoparticles and various cations effectively improved its uranium adsorption capacity. Also, results showed that under optimum condition of pH=7.56, contact time of 60min at 27°C with solid-liquid ratio of 20g/L a maximum uranium removal efficiency of 99.7% can be obtained in the presence of all anions and cations which are available in the drinking waters by NaX/ZnO nanocomposite. Copyright © 2016 Elsevier Ltd. All rights reserved.

A METHOD OF PREPARING URANIUM DIOXIDE

DOEpatents

Scott, F.A.; Mudge, L.K.

1963-12-17

A process of purifying raw, in particular plutonium- and fission- products-containing, uranium dioxide is described. The uranium dioxide is dissolved in a molten chloride mixture containing potassium chloride plus sodium, lithium, magnesium, or lead chloride under anhydrous conditions; an electric current and a chlorinating gas are passed through the mixture whereby pure uranium dioxide is deposited on and at the same time partially redissolved from the cathode. (AEC)

Uranium in mining water of kaolin open pit in Zarów (Lower Silesia); methodology of determination and genetic remarks.

PubMed

Chau, N D; Wyszomirski, P; Chruściel, E; Ochoński, A

1999-11-01

In this paper, a method of determination of uranium 238 and 234 in mining waters of Andrzej kaolin open pit in Zarów (Lower Silesia) is presented. The method is based on independent measurements of alpha and beta radiation intensities by means of a liquid scintillation spectrometer alpha/beta. The initial volume of water sample was 3 dm3, then it was diminished by chemical preparation to 6 cm3, and then 12 cm3 of scintillator was added. The lower limit of detection (for the measurement time of 8 h) for both 234U and 238U amounted to 0.02 Bq/dm3. For determination of the uranium content in ferruginous sediments precipitating from mining waters of the above-mentioned open pit, gamma ray spectrometry was used. The obtained results may be viewed as a contribution to studies on anomalous uranium concentration within this kaolin deposit. The elevated uranium content, in comparison with its average concentration in the Earth crust, is characteristic for parent rocks of Andrzej kaolin deposit, which are granitoids of Strzegom-Sobótka massif. In connection with it, the high uranium content can be observed not only in kaolin and weakly kaolinised granitoids from the deposit in question, but also in mining waters genetically related with them.

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

PubMed

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

2017-02-15

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

Restructuring the Uranium Mining Industry in Romania: Actual Situation and Prospects

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

Georgescu, P.D.; Petrescu, S.T.; Iuhas, T.F.

2002-07-01

Uranium prospecting in Romania has started some 50 years ago, when a bilateral agreement between Romania and the former Soviet Union had been concluded and a joint Romanian-Soviet enterprise was created. The production started in 1952 by the opening of some deposits from western Transylvania (Bihor and Ciudanovita). From 1962 the production has continued only with Romanian participation on the ore deposit Avram Iancu and from 1985 on the deposits from Eastern Carpathians (Crucea and Botusana). Starting with 1978 the extracted ores have been completely processed in the Uranium Ore Processing Plant from Feldioara, Brasov. Complying with the initial stipulationsmore » of the Nuclear National Program launched at the beginning of the 1980's, the construction of a nuclear power station in Cernavoda has started in Romania, using natural uranium and heavy water (CANDU type), having five units of 650 MW installed capacity. After 1989 this initial Nuclear National Program was revised and the construction of the first unit (number 1) was finalized and put in operation in 1996. In 2001 the works at the unit number 2 were resumed, having the year 2005 as the scheduled activating date. The future of the other 3 units, being in different construction phases, hasn't been clearly decided. Taking into consideration the exhaustion degree of some ore deposits and from the prospect of exploiting other ore deposits, the uranium industry will be subject of an ample restructuring process. This process includes workings of modernization of the mines in operation and of the processing plant, increasing the profitableness, lowering of the production costs by closing out and ecological rehabilitation of some areas affected by mining works and even new openings of some uraniferous exploitations. This paper presents the actual situation and the prospects of uranium mining industry on the base of some new technical and economical strategic concepts in accordance with the actual Romanian Program for Nuclear Energetics. (authors)« less

PROCESS OF PURIFYING URANIUM

DOEpatents

Seaborg, G.T.; Orlemann, E.F.; Jensen, L.H.

1958-12-23

A method of obtaining substantially pure uranium from a uranium composition contaminated with light element impurities such as sodium, magnesium, beryllium, and the like is described. An acidic aqueous solution containing tetravalent uranium is treated with a soluble molybdate to form insoluble uranous molybdate which is removed. This material after washing is dissolved in concentrated nitric acid to obtaln a uranyl nitrate solution from which highly purified uranium is obtained by extraction with ether.

Uranium resource assessment by the Geological Survey; methodology and plan to update the national resource base

USGS Publications Warehouse

Finch, Warren Irvin; McCammon, Richard B.

1987-01-01

Based on the Memorandum of Understanding {MOU) of September 20, 1984, between the U.S. Geological Survey of the U.S. Department of Interior and the Energy Information Administration {EIA) of the U.S. Department of Energy {DOE), the U.S. Geological Survey began to make estimates of the undiscovered uranium endowment of selected areas of the United States in 1985. A modified NURE {National Uranium Resource Evaluation) method will be used in place of the standard NURE method of the DOE that was used for the national assessment reported in October 1980. The modified method, here named the 'deposit-size-frequency' {DSF) method, is presented for the first time, and calculations by the two methods are compared using an illustrative example based on preliminary estimates for the first area to be evaluated under the MOU. The results demonstrate that the estimate of the endowment using the DSF method is significantly larger and more uncertain than the estimate obtained by the NURE method. We believe that the DSF method produces a more realistic estimate because the principal factor estimated in the endowment equation is disaggregated into more parts and is more closely tied to specific geologic knowledge than by the NURE method. The DSF method consists of modifying the standard NURE estimation equation, U=AxFxTxG, by replacing the factors FxT by a single factor that represents the tonnage for the total number of deposits in all size classes. Use of the DSF method requires that the size frequency of deposits in a known or control area has been established and that the relation of the size-frequency distribution of deposits to probable controlling geologic factors has been determined. Using these relations, the principal scientist {PS) first estimates the number and range of size classes and then, for each size class, estimates the lower limit, most likely value, and upper limit of the numbers of deposits in the favorable area. Once these probable estimates have been refined by elicitation of the PS, they are entered into the DSF equation, and the probability distribution of estimates of undiscovered uranium endowment is calculated using a slight modification of the program by Ford and McLaren (1980). The EIA study of the viability of the domestic uranium industry requires an annual appraisal of the U.S. uranium resource situation. During DOE's NURE Program, which was terminated in 1983, a thorough assessment of the Nation's resources was completed. A comprehensive reevaluation of uranium resource base for the entire United States is not possible for each annual appraisal. A few areas are in need of future study, however, because of new developments in either scientific knowledge, industry exploration, or both. Four geologic environments have been selected for study by the U.S. Geological Survey in the next several years: (1) surficial uranium deposits throughout the conterminous United States, (2) uranium in collapse-breccia pipes in the Grand Canyon region of Arizona, (3) uranium in Tertiary sedimentary rocks of the Northern Great Plains, and (4) uranium in metamorphic rocks of the Piedmont province in the eastern States. In addition to participation in the National uranium resource assessment, the U.S. Geological Survey will take part in activities of the Nuclear Energy Agency of the Organization for Economic Cooperation and Development and those of the International Atomic Energy Agency.

Uranium(VI) Scavenging by Amorphous Iron Phosphate Encrusting Sphaerotilus natans Filaments.

PubMed

Seder-Colomina, Marina; Morin, Guillaume; Brest, Jessica; Ona-Nguema, Georges; Gordien, Nilka; Pernelle, Jean-Jacques; Banerjee, Dipanjan; Mathon, Olivier; Esposito, Giovanni; van Hullebusch, Eric D

2015-12-15

U(VI) sorption to iron oxyhydroxides, precipitation of phosphate minerals, as well as biosorption on bacterial biomass are among the most reported processes able to scavenge U(VI) under oxidizing conditions. Although phosphates significantly influence bacterially mediated as well as iron oxyhydroxide mediated scavenging of uranium, the sorption or coprecipitation of U(VI) with poorly crystalline nanosized iron phosphates has been scarcely documented, especially in the presence of microorganisms. Here we show that dissolved U(VI) can be bound to amorphous iron phosphate during their deposition on Sphaerotilus natans filamentous bacteria. Uranium LIII-edge EXAFS analysis reveals that the adsorbed uranyl ions share an equatorial oxygen atom with a phosphate tetrahedron of the amorphous iron phosphate, with a characteristic U-P distance of 3.6 Å. In addition, the uranyl ions are connected to FeO6 octahedra with U-Fe distances at ~3.4 Å and at ~4.0 Å. The shortest U-Fe distance corresponds to a bidentate edge-sharing complex often reported for uranyl adsorption onto iron oxyhydroxides, whereas the longest U-Fe and U-P distances can be interpreted as a bidentate corner-sharing complex, in which two adjacent equatorial oxygen atoms are shared with the vertices of a FeO6 octahedron and of a phosphate tetrahedron. Furthermore, based on these sorption reactions, we demonstrate the ability of an attached S. natans biofilm to remove uranium from solution without any filtration step.

Biosorption of uranium by Pseudomonas aeruginosa strain CSU: Characterization and comparison studies

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

Hu, M.Z.C.; Norman, J.M.; Faison, B.D.

1996-07-20

Pseudomonas aeruginosa strain CSU, a nongenetically engineered bacterial strain known to bind dissolved hexavalent uranium (as UO{sub 2}{sup 2+} and/or its cationic hydroxo complexes) was characterized with respect to its sorptive activity. The uranium biosorption equilibrium could be described by the Langmuir isotherm. The rate of uranium adsorption increased following permeabilization of the outer and/or cytoplasmic membrane by organic solvents such as acetone. P. aeruginosa CSU biomass was significantly more sorptive toward uranium than certain novel, patented biosorbents derived from algal or fungal biomass sources. P. aeruginosa CSU biomass was also competitive with commercial cation-exchange resins, particularly in the presencemore » of dissolved transition metals. Uranium binding by P. aeruginosa CSU was clearly pH dependent. Uranium loading capacity increased with increasing pH under acidic conditions, presumably as a function of uranium speciation and due to the H{sup +} competition at some binding sites. Nevertheless, preliminary evidence suggests that this microorganism is also capable of binding anionic hexavalent uranium complexes. Ferric iron was a strong inhibitor of uranium binding to P. aeruginosa CSU biomass, and the presence of uranium also decreased the Fe{sup 3+} loading when the biomass was not saturated with Fe{sup 3+}. Thus, a two-state process in which iron and uranium are removed in consecutive steps was proposed for efficient use of the biomass as a biosorbent in uranium removal from mine wastewater, especially acidic leachates.« less

Rapid and efficient uranium(VI) capture by phytic acid/polyaniline/FeOOH composites.

PubMed

Wei, Xintao; Liu, Qi; Zhang, Hongsen; Liu, Jingyuan; Chen, Rongrong; Li, Rumin; Li, Zhangshuang; Liu, Peili; Wang, Jun

2018-02-01

Uranium plays an indispensable role in nuclear energy, but there are limited land resources to meet the ever growing demand; therefore, a need exists to develop efficient materials for capturing uranium from water. Herein, we synthesize a promising adsorbent of phytic acid/polyaniline/FeOOH composites (PA/PANI/FeOOH) by oxidative polymerization. Phytic acid, acting asa gelator and dopant, plays an important role in the formation of polyaniline (PANI). The PA/PANI/FeOOH exhibites high adsorption capacity (q m =555.8mgg -1 , T=298K), rapid adsorption rate (within 5min), excellent selectivity and cyclic stability. In addition, the results show that the adsorption isotherm is well fitted to the Langmuir isotherm model, and the adsorption kinetics agree with a pseudo-second order model. XPS analysis indicates that the removal of uranium is mainly attributed to abundant amine and imine groups on the surface of PA/PANI/FeOOH. Importantly, the removal of uranium from low concentrations of simulated seawater is highly efficient with a removal rate exceeding 92%. From our study, superior adsorption capacities, along with a low-cost, environmentally friendly and facile synthesis, reveal PA/PANI/FeOOH asa promising material for uranium capture. Copyright © 2017. Published by Elsevier Inc.

DOUBLE TRACKS Test Site interim corrective action plan

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

NONE

The DOUBLE TRACKS site is located on Range 71 north of the Nellis Air Force Range, northwest of the Nevada Test Site (NTS). DOUBLE TRACKS was the first of four experiments that constituted Operation ROLLER COASTER. On May 15, 1963, weapons-grade plutonium and depleted uranium were dispersed using 54 kilograms of trinitrotoluene (TNT) explosive. The explosion occurred in the open, 0.3 m above the steel plate. No fission yield was detected from the test, and the total amount of plutonium deposited on the ground surface was estimated to be between 980 and 1,600 grams. The test device was composed primarilymore » of uranium-238 and plutonium-239. The mass ratio of uranium to plutonium was 4.35. The objective of the corrective action is to reduce the potential risk to human health and the environment and to demonstrate technically viable and cost-effective excavation, transportation, and disposal. To achieve these objectives, Bechtel Nevada (BN) will remove soil with a total transuranic activity greater then 200 pCI/g, containerize the soil in ``supersacks,`` transport the filled ``supersacks`` to the NTS, and dispose of them in the Area 3 Radioactive Waste Management Site. During this interim corrective action, BN will also conduct a limited demonstration of an alternative method for excavation of radioactive near-surface soil contamination.« less

THERMAL DECOMPOSITION OF URANIUM COMPOUNDS

DOEpatents

Magel, T.T.; Brewer, L.

1959-02-10

A method is presented of preparing uranium metal of high purity consisting contacting impure U metal with halogen vapor at between 450 and 550 C to form uranium halide vapor, contacting the uranium halide vapor in the presence of H/sub 2/ with a refractory surface at about 1400 C to thermally decompose the uranium halides and deposit molten U on the refractory surface and collecting the molten U dripping from the surface. The entire operation is carried on at a sub-atmospheric pressure of below 1 mm mercury.

REMOVAL OF URANIUM FROM DRINKING WATER BY CONVENTIONAL TREATMENT METHODS

EPA Science Inventory

The USEPA currently does not regulate uranium in drinking water but will be revising the radionuclide regulations during 1989 and will propose a maximum contaminant level for uranium. The paper presents treatment technology information on the effectiveness of conventional method...

The Effect of Si and Al Concentration Ratios on the Removal of U(VI) under Hanford Site 200 Area Conditions-12115

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

Katsenovich, Yelena; Gonzalez, Nathan; Moreno-Pastor, Carol

2012-07-01

Injection of reactive gases, such as NH{sub 3}, is an innovative technique to mitigate uranium contamination in soil for a vadose zone (VZ) contaminated with radionuclides. A series of experiments were conducted to examine the effect of the concentration ratio of silicon to aluminum in the presence of various bicarbonate concentrations on the coprecipitation process of U(VI). The concentration of Al in all tests remained unchanged at 2.8 mM. Experiments showed that the removal efficiency of uranium was not significantly affected by the different bicarbonate and U(VI) concentrations tested. For the lower Si:Al molar ratios of 2:1 and 18:1, themore » removal efficiency of uranium was relatively low (≤ 8%). For the Si:Al molar ratio of 35:1, the removal efficiency of uranium was increased to an average of ∼82% for all bicarbonate concentrations tested. At higher Si:Al molar ratios (53:1 and above), a relatively high removal efficiency of U(VI), approximately 85% and higher, was observed. These results demonstrate that the U(VI) removal efficiency is more affected by the Si:Al molar ratio than by the bicarbonate concentration in solution. The results of this experiment are promising for the potential implementation of NH{sub 3} gas injection for the remediation of U(VI) -contaminated VZ. (authors)« less

Uranium(VI) interactions with mackinawite in the presence and absence of bicarbonate and oxygen

USGS Publications Warehouse

Gallegos, Tanya J.; Fuller, Christopher C.; Webb, Samuel M.; Betterton, William J.

2013-01-01

Mackinawite, Fe(II)S, samples loaded with uranium (10-5, 10-4, and 10-3 mol U/g FeS) at pH 5, 7, and 9, were characterized using X-ray absorption spectroscopy and X-ray diffraction to determine the effects of pH, bicarbonate, and oxidation on uptake. Under anoxic conditions, a 5 g/L suspension of mackinawite lowered 5 × 10-5 M uranium(VI) to below 30 ppb (1.26 × 10-7 M) U. Between 82 and 88% of the uranium removed from solution by mackinawite was U(IV) and was nearly completely reduced to U(IV) when 0.012 M bicarbonate was added. Near-neighbor coordination consisting of uranium–oxygen and uranium-uranium distances indicates the formation of uraninite in the presence and absence of bicarbonate, suggesting reductive precipitation as the dominant removal mechanism. Following equilibration in air, mackinawite was oxidized to mainly goethite and sulfur and about 76% of U(IV) was reoxidized to U(VI) with coordination of uranium to axial and equatorial oxygen, similar to uranyl. Additionally, uranium-iron distances, typical of coprecipitation of uranium with iron oxides, and uranium-sulfur distances indicating bidentate coordination of U(VI) to sulfate were evident. The affinity of mackinawite and its oxidation products for U(VI) provides impetus for further study of mackinawite as a potential reactive medium for remediation of uranium-contaminated water.

Optimization of Uranium Molecular Deposition for Alpha-Counting Sources

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

Monzo, Ellen; Parsons-Moss, Tashi; Genetti, Victoria

2016-12-12

Method development for molecular deposition of uranium onto aluminum 1100 plates was conducted with custom plating cells at Lawrence Livermore National Laboratory. The method development focused primarily on variation of electrode type, which was expected to directly influence plated sample homogeneity. Solid disc platinum and mesh platinum anodes were compared and data revealed that solid disc platinum anodes produced more homogenous uranium oxide films. However, the activity distribution also depended on the orientation of the platinum electrode relative to the aluminum cathode, starting current, and material composition of the plating cell. Experiments demonstrated these variables were difficult to control undermore » the conditions available. Variation of plating parameters among a series of ten deposited plates yielded variations up to 30% in deposition efficiency. Teflon particles were observed on samples plated in Teflon cells, which poses a problem for alpha activity measurements of the plates. Preliminary electropolishing and chemical polishing studies were also conducted on the aluminum 1100 cathode plates.« less

Removal of Uranium in Drinking Water: Brimac Environmental Services, Inc. Brimac HA 216 Adsorptive Media

EPA Science Inventory

The Brimac HA 216 Adsorptive Media was tested for uranium (U) removal from a drinking water source (well water) at Grappone Toyota located in Bow, New Hampshire. The HA 216 media is a hydroxyapatite-based material. A pilot unit, consisting of a TIGG Corporation Cansorb® C-5 ste...

Summary of the geology and resources of uranium in the San Juan Basin and adjacent region, New Mexico, Arizona, Utah, and Colorado

USGS Publications Warehouse

Ridgley, Jennie L.; Green, M.W.; Pierson, C.T.; Finch, W.I.; Lupe, R.D.

1978-01-01

The San Juan Basin and adjacent region lie predominantly in the southeastern part of the uranium-rich Colorado Plateau of New Mexico, Arizona, Utah, and Colorado. Underlying the province are rocks of the Precambrian basement complex composed mainly of igneous and metamorphic rocks; a thickness of about 3,600 meters of generally horizontal Paleozoic, Mesozoic, and Cenozoic sedimentary rocks; and a variety of Upper Cretaceous and Cenozoic igneous rocks. Sedimentary rocks of the sequence are commonly eroded and well exposed near the present basin margins where Tertiary tectonic activity has uplifted, folded, and faulted the sequence into its present geologic configuration of basins, platforms, monoclines, and other related structural features. Sedimentary rocks of Jurassic age in the southern part of the San Juan Basin contain the largest uranium deposits in the United States, and offer the promise of additional uranium deposits. Elsewhere in the basin and the adjacent Colorado Plateau, reserves and resources of uranium are known primarily in Triassic, Jurassic, and Cretaceous strata. Only scattered occurrences of uranium are known in Paleozoic

Acceptance Test Data for BWXT Coated Particle Batch 93164A Defective IPyC Fraction and Pyrocarbon Anisotropy

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

Helmreich, Grant W.; Hunn, John D.; Skitt, Darren J.

2017-02-01

Coated particle fuel batch J52O-16-93164 was produced by Babcock and Wilcox Technologies (BWXT) for possible selection as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), or may be used as demonstration production-scale coated particle fuel for other experiments. The tristructural-isotropic (TRISO) coatings were deposited in a 150-mm-diameter production-scale fluidizedbed chemical vapor deposition (CVD) furnace onto 425-μm-nominal-diameter spherical kernels from BWXT lot J52L-16-69316. Each kernel contained a mixture of 15.5%-enriched uranium carbide and uranium oxide (UCO) and was coated with four consecutive CVD layers:more » a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μm-nominal thickness. The TRISO-coated particle batch was sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batch was designated by appending the letter A to the end of the batch number (i.e., 93164A).« less

The application of illite supported nanoscale zero valent iron for the treatment of uranium contaminated groundwater.

PubMed

Jing, C; Landsberger, S; Li, Y L

2017-09-01

In this study, nanoscale zero valent iron I-NZVI was investigated as a remediation strategy for uranium contaminated groundwater from the former Cimarron Fuel Fabrication Site in Oklahoma, USA. The 1 L batch-treatment system was applied in the study. The result shows that 99.9% of uranium in groundwater was removed by I-NZVI within 2 h. Uranium concentration in the groundwater stayed around 27 μg/L, and there was no sign of uranium release into groundwater after seven days of reaction time. Meanwhile the release of iron was significantly decreased compared to NZVI which can reduce the treatment impact on the water environment. To study the influence of background pH of the treatment system on removal efficiency of uranium, the groundwater was adjusted from pH 2-10 before the addition of I-NZVI. The pH of the groundwater was from 2.1 to 10.7 after treatment. The removal efficiency of uranium achieved a maximum in neutral pH of groundwater. The desorption of uranium on the residual solid phase after treatment was investigated in order to discuss the stability of uranium on residual solids. After 2 h of leaching, 0.07% of the total uranium on residual solid phase was leached out in a HNO 3 leaching solution with a pH of 4.03. The concentration of uranium in the acid leachate was under 3.2 μg/L which is below the EPA's maximum contaminant level of 30 μg/L. Otherwise, the concentration of uranium was negligible in distilled water leaching solution (pH = 6.44) and NaOH leaching solution (pH = 8.52). A desorption study shows that an acceptable amount of uranium on the residuals can be released into water system under strong acid conditions in short terms. For long term disposal management of the residual solids, the leachate needs to be monitored and treated before discharge into a hazardous landfill or the water system. For the first time, I-NZVI was applied for the treatment of uranium contaminated groundwater. These results provide proof that I-NZVI has improved performance compared to NZVI and is a promising technology for the restoration of complex uranium contaminated water resources. Copyright © 2017 Elsevier Ltd. All rights reserved.

Comparison of heavy metals and uranium removal using adsorbent in soil

NASA Astrophysics Data System (ADS)

Choi, Jaeyoung; Yun, Hunsik

2017-04-01

This study investigates heavy metals (As, Ni, Zn, Cd, and Pb) and uranium removal onto geomaterials (limestone, black shale, and concrete) and biosorbents (Pseudomonas putida and starfish) from waste in soil. Geomaterials or biosorbents with a high capacity for heavy metals and uranium can be obtained and employed of with little cost. For investigating the neutralization capacity, the change in pH, Eh, and EC as a function of time was quantified. The adsorption of heavy metals and uranium by the samples was influenced by pH, and increased with increasing heavy metals and uranium concentrations. Dead cells adsorbed the largest quantity of all heavy metals than lother sorbents. The adsorption capacity followed the order: U(VI) > Pb > Cd > Ni. The results also suggest that bacterial membrane cells can be used successfully in the treatment of high strength metal-contaminated soil.

Effects of ammonium on uranium partitioning and kaolinite mineral dissolution.

PubMed

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

2017-02-01

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

Landsat analysis for uranium exploration in Northeast Turkey

USGS Publications Warehouse

Lee, Keenan

1983-01-01

No uranium deposits are known in the Trabzon, Turkey region, and consequently, exploration criteria have not been defined. Nonetheless, by analogy with uranium deposits studied elsewhere, exploration guides are suggested to include dense concentrations of linear features, lineaments -- especially with northwest trend, acidic plutonic rocks, and alteration indicated by limonite. A suite of digitally processed images of a single Landsat scene served as the image base for mapping 3,376 linear features. Analysis of the linear feature data yielded two statistically significant trends, which in turn defined two sets of strong lineaments. Color composite images were used to map acidic plutonic rocks and areas of surficial limonitic materials. The Landsat interpretation yielded a map of these exploration guides that may be used to evaluate relative uranium potential. One area in particular shows a high coincidence of favorable indicators.

PROCESS FOR REMOVING ALUMINUM COATINGS

DOEpatents

Flox, J.

1959-07-01

A process is presented for removing aluminum jackets or cans from uranium slugs. This is accomplished by immersing the aluminum coated uranium slugs in an aqueous solution of 9 to 20% sodium hydroxide and 35 to 12% sodium nitrate to selectively dissolve the aluminum coating, the amount of solution being such as to obtain a molar ratio of sodium hydroxide to aluminum of at least

Arsenic and Uranium Removal from Drinking Water by Adsorptive Media U.S. EPA Demonstration Project at Upper Bodfish in Lake Isabella, CA -Final Performance Evaluation Report

EPA Science Inventory

This report documents the activities performed during and the results obtained from the performance evaluation of an arsenic (As) and uranium (U) removal technology demonstrated at Upper Bodfish in Lake Isabella, CA. The objectives of the project are to evaluate: (1) the effecti...

Assessment of undiscovered sandstone-hosted uranium resources in the Texas Coastal Plain, 2015

USGS Publications Warehouse

Mihalasky, Mark J.; Hall, Susan M.; Hammarstrom, Jane M.; Tureck, Kathleen R.; Hannon, Mark T.; Breit, George N.; Zielinski, Robert A.; Elliott, Brent

2015-12-02

The U.S. Geological Survey estimated a mean of 220 million pounds of recoverable uranium oxide (U3O8 ) remaining as potential undiscovered resources in southern Texas. This estimate used a geology-based assessment method for Tertiary sandstone-hosted uranium deposits in the Texas Coastal Plain sedimentary strata (fig.1).

Nuclear Proliferation in the Middle East: Implications for the Superpowers,

DTIC Science & Technology

1982-01-01

when Israeli nuclear scientists began extracting low grade uranium from phosphate deposits in the Negev Desert. With the encouragement of Chaim... Negev -and concomitantly assisted in de- signing the research facilities associated with the reactor. By the time the reactor went critical in 1964, a...deposits in the Negev . Since the early 1970s, an esti- mated 40-50 tons of uranium oxide has been produced annually.1 6 In addition, unconfirmed

Inherently safe in situ uranium recovery

DOEpatents

Krumhansl, James L; Brady, Patrick V

2014-04-29

An in situ recovery of uranium operation involves circulating reactive fluids through an underground uranium deposit. These fluids contain chemicals that dissolve the uranium ore. Uranium is recovered from the fluids after they are pumped back to the surface. Chemicals used to accomplish this include complexing agents that are organic, readily degradable, and/or have a predictable lifetime in an aquifer. Efficiency is increased through development of organic agents targeted to complexing tetravalent uranium rather than hexavalent uranium. The operation provides for in situ immobilization of some oxy-anion pollutants under oxidizing conditions as well as reducing conditions. The operation also artificially reestablishes reducing conditions on the aquifer after uranium recovery is completed. With the ability to have the impacted aquifer reliably remediated, the uranium recovery operation can be considered inherently safe.

Wall-rock control of cortain pitchblende deposits in Golden Gate Canyon, Jefferson County, Colorado

USGS Publications Warehouse

Adams, John W.; Stugard, Frederick

1954-01-01

Carbonate veins cutting pre-Cambrian metamorphic rocks in Golden Gate Canyon contain pitchblende and base-metal sulfides. The veins occupy extensive faults of Laramide age but normally contain pitchblende only where the cut hornblende gneiss. At the Union Pacific prospect, which was studied in detail, pitchblende, hermatite, and some ankerite formed in advance of sulfides, except possibly for minor pyrite. Base-metal sulfides and the bulk of ankerite-calcite vein-filling were deposited after the pitchblende. Chemical analyses show a high ferrous iron content in the hornblende gneiss in contrast to low ferrous iron in the adjacent biotite gneiss. It is hypothesized that ferrous iron released by alteration of hornblende was partly oxidized to hematite by the ore-bearing solutions and, contemporaneously, uranium was reduced and deposited as pitchblende. In other veins, biotite or iron sulfides may have been similarly effective in precipitating pitchblende. Apparently both the ferrous ion and the sulfide ion can serve as reducing agents and control pitchblende deposition. It is suggested that conditions particularly favorable for uranium deposition are present where uranium-bearing solutions had access to rocks rich in ferrous iron or pre-existing sulfides.

Some emerging applications of lasers

NASA Astrophysics Data System (ADS)

Christensen, C. P.

1982-10-01

Applications of lasers in photochemistry, advanced instrumentation, and information storage are discussed. Laser microchemistry offers a number of new methods for altering the morphology of a solid surface with high spatial resolution. Recent experiments in material deposition, material removal, and alloying and doping are reviewed. A basic optical disk storage system is described and the problems faced by this application are discussed, in particular those pertaining to recording media. An advanced erasable system based on the magnetooptic effect is described. Applications of lasers for remote sensing are discussed, including various lidar systems, the use of laser-induced fluorescence for oil spill characterization and uranium exploration, and the use of differential absorption for detection of atmospheric constituents, temperature, and humidity.

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

NASA Astrophysics Data System (ADS)

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

2009-04-01

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

Rapid removal of uranium from aqueous solutions using magnetic Fe3O4@SiO2 composite particles.

PubMed

Fan, Fang-Li; Qin, Zhi; Bai, Jing; Rong, Wei-Dong; Fan, Fu-You; Tian, Wei; Wu, Xiao-Lei; Wang, Yang; Zhao, Liang

2012-04-01

Rapid removal of U(VI) from aqueous solutions was investigated using magnetic Fe(3)O(4)@SiO(2) composite particles as the novel adsorbent. Batch experiments were conducted to study the effects of initial pH, amount of adsorbent, shaking time and initial U(VI) concentrations on uranium sorption efficiency as well as the desorbing of U(VI). The sorption of uranium on Fe(3)O(4)@SiO(2) composite particles was pH-dependent, and the optimal pH was 6.0. In kinetics studies, the sorption equilibrium can be reached within 180 min, and the experimental data were well fitted by the pseudo-second-order model, and the equilibrium sorption capacities calculated by the model were almost the same as those determined by experiments. The Langmuir sorption isotherm model correlates well with the uranium sorption equilibrium data for the concentration range of 20-200 mg/L. The maximum uranium sorption capacity onto magnetic Fe(3)O(4)@SiO(2) composite particles was estimated to be about 52 mg/g at 25 °C. The highest values of uranium desorption (98%) was achieved using 0.01 M HCl as the desorbing agent. Fe(3)O(4)@SiO(2) composite particles showed a good selectivity for uranium from aqueous solution with other interfering cation ions. Present study suggested that magnetic Fe(3)O(4)@SiO(2) composite particles can be used as a potential adsorbent for sorption uranium and also provided a simple, fast separation method for removal of heavy metal ion from aqueous solution. Copyright © 2011 Elsevier Ltd. All rights reserved.

METHOD OF PREPARING URANIUM, THORIUM, OR PLUTONIUM OXIDES IN LIQUID BISMUTH

DOEpatents

Davidson, J.K.; Robb, W.L.; Salmon, O.N.

1960-11-22

A method is given for forming compositions, as well as the compositions themselves, employing uranium hydride in a liquid bismuth composition to increase the solubility of uranium, plutonium and thorium oxides in the liquid bismuth. The finely divided oxide of uranium, plutonium. or thorium is mixed with the liquid bismuth and uranium hydride, the hydride being present in an amount equal to about 3 at. %, heated to about 5OO deg C, agitated and thereafter cooled and excess resultant hydrogen removed therefrom.

APPARATUS FOR CHARGING A RECEPTACLE WITH A DENSE SUBLIMATE FORM OF URANIUM CHLORIDE

DOEpatents

Davidson, P.H.

1959-08-18

An apparatus for filling a tubular storage receptacle with a dense massive form of uranium chloride is described. The apparatus includes an evacuated housing divided into a vaporizing chamber and a portion adapted to receive the receptacle. A nozzle conducts vaporized uranium chloride from the chamber to the interior of the receptacle. The nozzle is withdrawable to progressively deposit the uranium chloride under controlled conditions to produce a dense sublimate which fills the receptacle.

Methods for making a porous nuclear fuel element

DOEpatents

Youchison, Dennis L; Williams, Brian E; Benander, Robert E

2014-12-30

Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

Study of behaviors of aluminum overlayers deposited on uranium via AES, EELS, and XPS

NASA Astrophysics Data System (ADS)

Liu, Kezhao; Luo, Lizhu; Zhou, Wei; Yang, Jiangrong; Xiao, Hong; Hong, Zhanglian; Yang, Hui

2013-04-01

Aluminum overlayers on uranium were prepared by sputtering at room temperature in an ultra-high vacuum chamber. The growth mode of aluminum overlayers and behaviors of the Al/U interface reaction were studied in situ by auger electron spectroscopy, electron energy loss spectroscopy, and X-ray photoelectron spectroscopy. The results suggested that the interdiffusion took place at the Al/U interface during the initial stage of deposition. The U4f spectra of the Al/U interface showed strong correlation satellites at binding energies of 380.4 and 392.7 eV and plasma loss features at 404.2 eV, respectively. The interactions between aluminum and uranium yielded the intermetallic compound of UAlx, inducing the shift to a low binding energy for Al2p peaks. The results indicated that aluminum overlayers were formed on the uranium by sputtering in an island growth mode.

The effect of Si and Al concentrations on the removal of U(VI) in the alkaline conditions created by NH3 gas

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

Katsenovich, Yelena P.; Cardona, Claudia; Lapierre, Robert

2016-10-01

Remediation of uranium in the deep unsaturated zone is a challenging task, especially in the presence of oxygenated, high-carbonate alkalinity soil and pore water composition typical for arid and semi-arid environments of the western regions of the U.S. This study evaluates the effect of various pore water constituencies on changes of uranium concentrations in alkaline conditions, created in the presence of reactive gases such as NH3 to effectively mitigate uranium contamination in the vadose zone sediments. This contaminant is a potential source for groundwater pollution through slow infiltration of soluble and highly mobile uranium species towards the water table. Themore » objective of this research was to evaluate uranium sequestration efficiencies in the alkaline synthetic pore water solutions prepared in a broad range of Si, Al, and bicarbonate concentrations typically present in field systems of the western U.S. regions and identify solid uranium-bearing phases that result from ammonia gas treatment. In previous studies (Szecsody et al. 2012; Zhong et al. 2015), although uranium mobility was greatly decreased, solid phases could not be identified at the low uranium concentrations in field-contaminated sediments. The chemical composition of the synthetic pore water used in the experiments varied for silica (5–250 mM), Al3+ (2.8 or 5 mM), HCO3- (0–100 mM) and U(VI) (0.0021–0.0084 mM) in the solution mixture. Experiment results suggested that solutions with Si concentrations higher than 50 mM exhibited greater removal efficiencies of U(VI). Solutions with higher concentrations of bicarbonate also exhibited greater removal efficiencies for Si, Al, and U(VI). Overall, the silica polymerization reaction leading to the formation of Si gel correlated with the removal of U(VI), Si, and Al from the solution. If no Si polymerization was observed, there was no U removal from the supernatant solution. Speciation modeling indicated that the dominant uranium species in the presence of bicarbonate were anionic uranyl carbonate complexes (UO2(CO3)2-2 and UO2(CO3)3-4) and in the absence of bicarbonate in the solution, U(VI) major species appeared as uranyl-hydroxide (UO2(OH)3- and UO2(OH)4-2) species. The model also predicted the formation of uranium solid phases. Uranyl carbonates as rutherfordine [UO2CO3], cejkaite [Na4(UO2)(CO3)3] and hydrated uranyl silicate phases as Na-boltwoodite [Na(UO2)(SiO4)·1.5H2O] were anticipated for most of the synthetic pore water compositions amended from medium (2.9 mM) to high (100 mM) bicarbonate concentrations.« less

Natural Radioactivity in Soil and Water from Likuyu Village in the Neighborhood of Mkuju Uranium Deposit

PubMed Central

Mohammed, Najat K.; Mazunga, Mohamed S.

2013-01-01

The discovery of high concentration uranium deposit at Mkuju, southern part of Tanzania, has brought concern about the levels of natural radioactivity at villages in the neighborhood of the deposit. This study determined the radioactivity levels of 30 soil samples and 20 water samples from Likuyu village which is 54 km east of the uranium deposit. The concentrations of the natural radionuclides 238U, 232Th, and 40K were determined using low level gamma spectrometry of the Tanzania Atomic Energy Commission (TAEC) Laboratory in Arusha. The average radioactivity concentrations obtained in soil samples for 238U (51.7 Bq/kg), 232Th (36.4 Bq/kg), and 40K (564.3 Bq/kg) were higher than the worldwide average concentrations value of these radionuclides reported by UNSCEAR, 2000. The average activity concentration value of 238U (2.35 Bq/L) and 232Th (1.85 Bq/L) in water samples was similar and comparable to their mean concentrations in the control sample collected from Nduluma River in Arusha. PMID:23781247

Olympic Dam copper-uranium-gold deposit, South Australia

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

Lalor, J.H.

1986-07-01

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

ANALYSIS OF 2H-EVAPORATOR SCALE WALL [HTF-13-82] AND POT BOTTOM [HTF-13-77] SAMPLES

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

Oji, L.

2013-06-21

Savannah River Remediation (SRR) is planning to remove a buildup of sodium aluminosilicate scale from the 2H-evaporator pot by loading and soaking the pot with heated 1.5 M nitric acid solution. Sampling and analysis of the scale material has been performed so that uranium and plutonium isotopic analysis can be input into a Nuclear Criticality Safety Assessment (NCSA) for scale removal by chemical cleaning. Historically, since the operation of the Defense Waste Processing Facility (DWPF), silicon in the DWPF recycle stream combines with aluminum in the typical tank farm supernate to form sodium aluminosilicate scale mineral deposits in the 2Hevaporatormore » pot and gravity drain line. The 2H-evaporator scale samples analyzed by Savannah River National Laboratory (SRNL) came from the bottom cone sections of the 2H-evaporator pot [Sample HTF-13-77] and the wall 2H-evaporator [sample HTF-13-82]. X-ray diffraction analysis (XRD) confirmed that both the 2H-evaporator pot scale and the wall samples consist of nitrated cancrinite (a crystalline sodium aluminosilicate solid) and clarkeite (a uranium oxy-hydroxide mineral). On “as received” basis, the bottom pot section scale sample contained an average of 2.59E+00 ± 1.40E-01 wt % total uranium with a U-235 enrichment of 6.12E-01 ± 1.48E-02 %, while the wall sample contained an average of 4.03E+00 ± 9.79E-01 wt % total uranium with a U-235 enrichment of 6.03E-01% ± 1.66E-02 wt %. The bottom pot section scale sample analyses results for Pu-238, Pu-239, and Pu-241 are 3.16E- 05 ± 5.40E-06 wt %, 3.28E-04 ± 1.45E-05 wt %, and <8.80E-07 wt %, respectively. The evaporator wall scale samples analysis values for Pu-238, Pu-239, and Pu-241 averages 3.74E-05 ± 6.01E-06 wt %, 4.38E-04 ± 5.08E-05 wt %, and <1.38E-06 wt %, respectively. The Pu-241 analyses results, as presented, are upper limit values. These results are provided so that SRR can calculate the equivalent uranium-235 concentrations for the NCSA. Results confirm that the uranium contained in the scale remains depleted with respect to natural uranium. SRNL did not calculate an equivalent U-235 enrichment, which takes into account other fissionable isotopes U-233, Pu-239 and Pu-241. The applicable method for calculation of equivalent U-235 will be determined in the NCSA.« less

Webinar on the Removal of Uranium from Drinking Water by Small System Treatment Technology

EPA Science Inventory

Abstract: Radionuclides, such as uranium (U), occur naturally as trace elements in rocks and soils and thus can be found in dissolved forms in ground waters. Uranium has four oxidation states (+3, +4, +5, and +6) and is a very reactive element forming a variety of stable complexe...

Development of Nitride Coating Using Atomic Layer Deposition for Low-Enriched Uranium Fuel Powder

NASA Astrophysics Data System (ADS)

Bhattacharya, Sumit

High-performance research reactors require fuel that operates at high specific power and can withstand high fission density, but at relatively low temperatures. The design of the research reactor fuels is done for efficient heat emission, and consists of assemblies of thin-plates cladding made from aluminum alloy. The low-enriched fuels (LEU) were developed for replacing high-enriched fuels (HEU) for these reactors necessitates a significantly increased uranium density in the fuel to counterbalance the decrease in enrichment. One of the most promising new fuel candidate is U-Mo alloy, in a U-Mo/Al dispersion fuel form, due to its high uranium loading as well as excellent irradiation resistance performance, is being developed extensively to convert from HEU fuel to LEU fuel for high-performance research reactors. However, the formation of an interaction layer (IL) between U-Mo particles and the Al matrix, and the associated pore formation, under high heat flux and high burnup conditions, degrade the irradiation performance of the U-Mo/Al dispersion fuel. From the recent tests results accumulated from the surface engineering of low enriched uranium fuel (SELENIUM) and MIR reactor displayed that a surface barrier coating like physical vapor deposited (PVD) zirconium nitride (ZrN) can significantly reduce the interaction layer. The barrier coating performed well at low burn up but above a fluence rate of 5x 1021 ions/cm2 the swelling reappeared due to formation interaction layer. With this result in mind the objective of this research was to develop an ultrathin ZrN coating over particulate uranium-molybdenum nuclear fuel using a modified savannah 200 atomic layer deposition (ALD) system. This is done in support of the US Department of Energy's (DOE) effort to slow down the interaction at fluence rate and reach higher burn up for high power research reactor. The low-pressure Savannah 200 ALD system is modified to be designed as a batch powder coating system using the metal organic chemical precursors tetrakis dimethylamido zirconium (TDMAZr) and ammonia( NH3) for succesful deposition of ZrN coating. Nitrogen (N2) gas carried the chemicals to a hot wall reactor maintained at a temperature range of 235 to 245 °C. The ALD system design evolved over the course of this research as the process variables were steadily improved. The conditions found deemed for attaining best coating were at a temperature of 245 °C, with pulse time of 0.8 seconds for TDMAZr and 0.1 seconds for NH3 along with 15 seconds of purge time in-between each cycle. The ALD system was successful in making 1-micrometer (um) ZrN with low levels of chemical impurities over U-Mo powder batches. The deposited coatings were characterized using scanning electron microscopy (SEM), energy dispersive spectroscopy (EDS), electron energy loss spectroscopy (EELS) and Transmission electron microscope (TEM). This document describes the establishment of the Savannah 200 ALD system, precursor surface reaction procedures and finally the nature of the coating achieved, including characterization of the coating at the different stages of deposition. It was found that an interlayer of alumina in between ZrN and the U-Mo surface was required to reduce the residual stress generated during the ALD procedure. The alumina not only removed the risk of cracking and spallation of the ZrN coating but also provided adequate strength for the barrier layer to withstand the fuel plate rolling conditions. The ZrN coating was nano crystalline in nature, with grain size varying from 5-10 nm, the deposited layer was found to be dense consisting of a layered structure. The coating could retain its crystallinity and maintain its phase when irradiated with 1 MeV single charged ion Kr to produce a damage of 10 displacement per atom (DPA) at intermediate voltage electron microscopy (IVEM).

Morphology of uranium electrodeposits on cathode in electrorefining process: A phase-field simulation

NASA Astrophysics Data System (ADS)

Shibuta, Yasushi; Sato, Takumi; Suzuki, Toshio; Ohta, Hirokazu; Kurata, Masaki

2013-05-01

Morphology of uranium electrodeposits on cathode with respect to applied voltage, zirconium concentration in the molten salt and the size of primary deposit during pyroprocessing is systematically investigated by the phase-field simulation. It is found that there is a threshold zirconium concentration in the molten salt demarcating planar and cellular/needle-like electrodeposits, which agrees with experimental results. In addition, the effect of size of primary deposits on the morphology of electrodeposits is examined. It is then confirmed that cellular/needle-like electrodeposits are formed from large primary deposits at all applied voltages considered, whereas both the planar and cellular/needle-like electrodeposits are formed from the primary deposits of 10 μm and less.

Effect of pH and Fe/U ratio on the U(VI) removal rate by the synergistic effect of Fe(II) and O2

NASA Astrophysics Data System (ADS)

Fu, Yukui; Luo, Yingfeng; Fang, Qi; Xie, Yanpei; Wang, Zhihong; Zhu, Xiangyu

2018-02-01

As for the decommissioned uranium deposits of acid in-situ leaching, both of the concentrations of U(VI) and Fe(II) are relatively high in groundwater. In the presence of O2, the oxidation of Fe(II) into Fe(III) that forms Fe-hydroxides could effectively remove U(VI) in the forms of sorption or co-precipitation. In this process, pH condition and Fe content will have a significant effect on the U(VI) removal rate by the synergistic effect of Fe(II) and O2. In the present work, a series of batch experiments were carried out to investigate the effect of pH values and Fe/U mass ratio on the U(VI) removal rate by the synergistic effect of Fe(II) and O2. Experiment results show that the removal rate of U(VI) is mainly controlled by pH and secondly by Fe/U mass ratio. In the neutral conditions with pH at 7 and 8, the removal rate of U(VI) reaches up to 90% for all solutions with different initial Fe(II) concentrations. The optimal pH for the removal rate of U(VI) is above 7. In the acidic conditions with pH below 6, the effect of Fe/U mass ratio on the removal rate of U(VI) becomes more obvious and the optimal Fe/U mass ratio for U(VI) removal is 1:2.

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

NASA Astrophysics Data System (ADS)

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

2018-05-01

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

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

NASA Astrophysics Data System (ADS)

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

2018-02-01

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

Reconnaissance for trace elements in North Dakota and eastern Montana. Part 1. Geology and radioactivity. Part 2. Reserves and summary

USGS Publications Warehouse

Wyant, Donald G.; Beroni, Ernest P.

1950-01-01

The exact mode of origin of the uranium in the lignite is not known. Uranium may have accumulated in swamps at the same time as the organic debris, or it may have been introduced by ground water after the formation of lignite. In either case carbon or carbon compounds apparently caused the precipitation or fixation of uranium. Further work is needed to determine the origin of this type of uranium deposit.

METHOD OF PRODUCING URANIUM METAL BY ELECTROLYSIS

DOEpatents

Piper, R.D.

1962-09-01

A process is given for making uranium metal from oxidic material by electrolytic deposition on the cathode. The oxidic material admixed with two moles of carbon per one mole of uranium dioxide forms the anode, and the electrolyte is a mixture of from 40 to 75% of calcium fluoride or barium fluoride, 15 to 45% of uranium tetrafluoride, and from 10 to 20% of lithium fluoride or magnesium fluoride; the temperature of the electrolyte is between 1150 and 1175 deg C. (AEC)

Reconnaissance for uranium-bearing carbonaceous rocks in California and adjacent parts of Oregon and Nevada

USGS Publications Warehouse

Moore, George Winfred; Stephens, James G.

1954-01-01

During the summer of 1952 a reconnaissance was conducted in California and parts of Oregon and Nevada in search of new deposits of uranium-bearing carbonaceous rocks. The principal localities found in California where uranium occurs in coal are listed here with. the uranium content of the coal: Newhall prospect, Los Angeles County, 0.020 percent; Fireflex mine, San Benito County, 0.005 percent; American licyaite mine, Amador County, 0.004 percent; and Tesla prospect, Alameda County, 0.003 percent. An oil-saturated sandstone near Edna, San Luis Obispo County, contains 0.002 percent uranium.

Leachability of uranium and other elements from freshly erupted volcanic ash

USGS Publications Warehouse

Smith, D.B.; Zielinski, R.A.; Rose, W.I.

1982-01-01

A study of leaching of freshly erupted basaltic and dacitic air-fall ash and bomb fragment samples, unaffected by rain, shows that glass dissolution is the dominant process by which uranium is initially mobilized from air-fall volcanic ash. Si, Li, and V are also preferentially mobilized by glass dissolution. Gaseous transfer followed by fixation of soluble uranium species on volcanic-ash particles is not an important process affecting uranium mobility. Gaseous transfer, however, may be important in forming water-soluble phases, adsorbed to ash surfaces, enriched in the economically and environmentally important elements Zn, Cu, Cd, Pb, B, F, and Ba. Quick removal of these adsorbed elements by the first exposure of freshly erupted ash to rain and surface water may pose short-term hazards to certain forms of aquatic and terrestrial life. Such rapid release of material may also represent the first step in transportation of economically important elements to environments favorable for precipitation into deposits of commercial interest. Ash samples collected from the active Guatemalan volcanoes Fuego and Pacaya (high-Al basalts) and Santiaguito (hornblende-hypersthene dacite); bomb fragments from Augustine volcano (andesite-dacite), Alaska, and Heimaey (basalt), Vestmann Islands, Iceland; and fragments of "rhyolitic" pumice from various historic eruptions were subjected to three successive leaches with a constant water-to-ash weight ratio of 4:1. The volcanic material was successively leached by: (1) distilled-deionized water (pH = 5.0-5.5) at room temperature for 24 h, which removes water-soluble gases and salts adsorbed on ash surfaces during eruption; (2) dilute HCl solution (pH = 3.5-4.0) at room temperature for 24 h, which continues the attack initiated by the water and also attacks acid-soluble sulfides and oxides; (3) a solution 0.05 M in both Na,CO, and NaHCO, (pH = 9.9) at 80°C for one week, which preferentially dissolves volcanic glass. The first two leaches mimic interaction of ash with rain produced in the vicinity of an active eruption. The third leach accelerates the effect of prolonged contact of volcanic ash with alkaline ground water present during ash diagenesis.

Boron coating on boron nitride coated nuclear fuels by chemical vapor deposition

NASA Astrophysics Data System (ADS)

Durmazuçar, Hasan H.; Gündüz, Güngör

2000-12-01

Uranium dioxide-only and uranium dioxide-gadolinium oxide (5% and 10%) ceramic nuclear fuel pellets which were already coated with boron nitride were coated with thin boron layer by chemical vapor deposition to increase the burn-up efficiency of the fuel during reactor operation. Coating was accomplished from the reaction of boron trichloride with hydrogen at 1250 K in a tube furnace, and then sintering at 1400 and 1525 K. The deposited boron was identified by infrared spectrum. The morphology of the coating was studied by using scanning electron microscope. The plate, grainy and string (fiber)-like boron structures were observed.

Rapidly-formed ferromanganese deposit from the eastern Pacific Hess Deep

USGS Publications Warehouse

Burnett, W.C.; Piper, D.Z.

1977-01-01

A thick ferromanganese deposit encrusting fresh basaltic glass has been dredged from the Hess Deep in the eastern Pacific. Contiguous layers within the Fe-Mn crust have been analysed for uranium-series isotopes and metal contents. The rate of accumulation of the deposit, based on the decline of uranium-unsupported 230Th, is calculated to be approximately 50 mm per 106 yr. Based on hydration-rind dating of the underlying glass and an 'exposure age' calculation, this rate is concluded to be too slow, and an accretion rate on the order of 1 mm per 103 yr is more consistent with our data. ?? 1977 Nature Publishing Group.

REMOVAL OF URANIUM FROM ORGANIC LIQUIDS

DOEpatents

Vavalides, S.P.

1959-08-25

A process is described for recovering small quantities of uranium from organic liquids such as hydrocarbon oils. halogen-substituted hydrocarbons, and alcohols. The organic liquid is contacted with a comminuted alkaline earth hydroxide, calcium hydroxide particularly, and the resulting uranium-bearing solid is separated from the liquid by filtration. Uranium may then be recovered from the solid by means of dissolution in nitric acid and conventional extraction with an organic solvent such as tributyl phosphate.

Acceptance Test Data for BWXT Coated Particle Batches 93172B and 93173B—Defective IPyC and Pyrocarbon Anisotropy

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

Hunn, John D.; Helmreich, Grant W.; Dyer, John A.

Coated particle batches J52O-16-93172B and J52O-16-93173B were produced by Babcock and Wilcox Technologies (BWXT) as part of the production campaign for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), but were not used in the final fuel composite. However, these batches may be used as demonstration production-scale coated particle fuel for other experiments. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT lot J52R-16-69317 containing a mixture ofmore » 15.5%-enriched uranium carbide and uranium oxide (UCO). The TRISO coatings consisted of four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μm-nominal thickness. The TRISO-coated particle batches were sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batches were designated by appending the letter A to the end of the batch number (e.g., 93172A). Secondary upgrading by sieving was performed on the A-designated batches to remove particles with missing or very-thin buffer layers that were identified during previous analysis of the individual batches for defective IPyC, as reported in the acceptance test data report for the AGR-5/6/7 production batches [Hunn et al. 2017b]. The additionally-upgraded batches were designated by appending the letter B to the end of the batch number (e.g., 93172B).« less

Advanced remediation of uranium-contaminated soil.

PubMed

Kim, S S; Han, G S; Kim, G N; Koo, D S; Kim, I G; Choi, J W

2016-11-01

The existing decontamination method using electrokinetic equipment after acidic washing for uranium-contaminated soil requires a long decontamination time and a significant amount of electric power. However, after soil washing, with a sulfuric acid solution and an oxidant at 65 °C, the removal of the muddy solution using a 100 mesh sieve can decrease the radioactivity of the remaining coarse soil to the clearance level. Therefore, only a small amount of fine soil collected from the muddy solution requires the electrokinetic process for its decontamination. Furthermore, it is found that the selective removal of uranium from the sulfuric washing solution is not obtained using an anion exchanger but rather using a cation exchanger, unexpectedly. More than 90% of the uranium in the soil washing solutions is adsorbed on the S-950 resin, and 87% of the uranium adsorbed on S-950 is desorbed by washing with a 0.5 M Na 2 CO 3 solution at 60 °C. Copyright © 2016 Elsevier Ltd. All rights reserved.

In situ remediation of uranium contaminated groundwater

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

Dwyer, B.P.; Marozas, D.C.

1997-02-01

In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ to acceptablemore » regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field results are discussed with regard to other potential contaminated groundwater treatment applications.« less

In situ remediation of uranium contaminated groundwater

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

Dwyer, B.P.; Marozas, D.C.

1997-12-31

In an effort to develop cost-efficient techniques for remediating uranium contaminated groundwater at DOE Uranium Mill Tailing Remedial Action (UMTRA) sites nationwide, Sandia National Laboratories (SNL) deployed a pilot scale research project at an UMTRA site in Durango, CO. Implementation included design, construction, and subsequent monitoring of an in situ passive reactive barrier to remove Uranium from the tailings pile effluent. A reactive subsurface barrier is produced by emplacing a reactant material (in this experiment - various forms of metallic iron) in the flow path of the contaminated groundwater. Conceptually the iron media reduces and/or adsorbs uranium in situ tomore » acceptable regulatory levels. In addition, other metals such as Se, Mo, and As have been removed by the reductive/adsorptive process. The primary objective of the experiment was to eliminate the need for surface treatment of tailing pile effluent. Experimental design, and laboratory and field preliminary results are discussed with regard to other potential contaminated groundwater treatment applications.« less

PRECIPITATION OF ZIRCONIUM AND FLUORIDE IONS FROM SOLUTIONS

DOEpatents

Newby, B.J.

1963-06-11

A process is given for removing zirconium and fluorine ions from aqueous solutions also containing uranium(VI). The precipitation is carried out with sodium formate, and the uranium remains in solution. (AEC)

Volumetric determination of uranium using titanous sulfate as reductant before oxidimetric titration

USGS Publications Warehouse

Wahlberg, James S.; Skinner, Dwight L.; Rader, Lewis F.

1956-01-01

A new method for determining uranium in samples containing 0.05 percent or more U3O8, using titanous sulfate as reducing agent, is much shorter, faster, and has fewer interferences than conventional methods using reductor columns. The sample is dissolved with sulfuric, nitric, perchloric, and hydrofluoric acids. Elements that would otherwise form insoluble fluorides are kept in solution by complexing the fluoride ion with boric acid. A precipitation is made with cupferron to remove interfering elements. The solution is filtered to remove the precipitated cupferrates instead of extracting them with chloroform as is usually done. Filtration is preferred to extraction because any niobium that may be in solution forms an insoluble cupferrate that may be removed by filtering but is very difficult to extract with chloroform. Excess cupferron is destroyed by oxidizing with nitric and perchloric acids, and evaporating to dense fumes of sulfuric acid. The uranium is reduced to U(IV) by the addition of titanous sulfate, with cupric sulfate used as an indicator of the completeness of the reduction. Metallic copper is formed when all the uranium is reduced. The reduced copper is then reoxidized by the addition of mercuric perchlorate, an excess of ferric sulfate added, and the solution titrated immediately with standard ceric sulfate with ferroin as an indicator. Precision of the method compared favorable with methods in common use, both for uranium ores and for most types of uranium-rich materials.

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

NASA Astrophysics Data System (ADS)

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

2015-10-01

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

Methods for manufacturing porous nuclear fuel elements for high-temperature gas-cooled nuclear reactors

DOEpatents

Youchison, Dennis L [Albuquerque, NM; Williams, Brian E [Pocoima, CA; Benander, Robert E [Pacoima, CA

2010-02-23

Methods for manufacturing porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's). Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, a thin coating of nuclear fuel may be deposited inside of a highly porous skeletal structure made, for example, of reticulated vitreous carbon foam.

Porous nuclear fuel element for high-temperature gas-cooled nuclear reactors

DOEpatents

Youchison, Dennis L [Albuquerque, NM; Williams, Brian E [Pacoima, CA; Benander, Robert E [Pacoima, CA

2011-03-01

Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

Porous nuclear fuel element with internal skeleton for high-temperature gas-cooled nuclear reactors

DOEpatents

Youchison, Dennis L.; Williams, Brian E.; Benander, Robert E.

2013-09-03

Porous nuclear fuel elements for use in advanced high temperature gas-cooled nuclear reactors (HTGR's), and to processes for fabricating them. Advanced uranium bi-carbide, uranium tri-carbide and uranium carbonitride nuclear fuels can be used. These fuels have high melting temperatures, high thermal conductivity, and high resistance to erosion by hot hydrogen gas. Tri-carbide fuels, such as (U,Zr,Nb)C, can be fabricated using chemical vapor infiltration (CVI) to simultaneously deposit each of the three separate carbides, e.g., UC, ZrC, and NbC in a single CVI step. By using CVI, the nuclear fuel may be deposited inside of a highly porous skeletal structure made of, for example, reticulated vitreous carbon foam.

ELUTION OF URANIUM VALUES FROM ION EXCHANGE RESINS

DOEpatents

Kennedy, R.H.

1959-11-24

A process is described for eluting complex uranium ions absorbed on ion exchange resins. The resin is subjected to the action of an aqueous eluting solution contuining sulfuric acid and an alkali metal, ammonium, or magnesium chloride or nitrate, the elution being carried out until the desired amount of the uranium is removed from the resin.

A study on possible use of Urtica dioica (common nettle) plants as uranium (234U, 238U) contamination bioindicator near phosphogypsum stockpile.

PubMed

Olszewski, Grzegorz; Boryło, Alicja; Skwarzec, Bogdan

The aim of this study was to determine uranium concentrations in common nettle ( Urtica dioica ) plants and corresponding soils samples which were collected from the area of phosphogypsum stockpile in Wiślinka (northern Poland). The uranium concentrations in roots depended on its concentrations in soils. Calculated BCF and TF values showed that soils characteristics and air deposition affect uranium absorption and that different uranium species have different affinities to U . dioica plants. The values of 234 U/ 238 U activity ratio indicate natural origin of these radioisotopes in analyzed plants. Uranium concentration in plants roots is negatively weakly correlated with distance from phosphogypsum stockpile.

Uranium-Loaded Water Treatment Resins: 'Equivalent Feed' at NRC and Agreement State-Licensed Uranium Recovery Facilities - 12094

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

Camper, Larry W.; Michalak, Paul; Cohen, Stephen

Community Water Systems (CWSs) are required to remove uranium from drinking water to meet EPA standards. Similarly, mining operations are required to remove uranium from their dewatering discharges to meet permitted surface water discharge limits. Ion exchange (IX) is the primary treatment strategy used by these operations, which loads uranium onto resin beads. Presently, uranium-loaded resin from CWSs and mining operations can be disposed as a waste product or processed by NRC- or Agreement State-licensed uranium recovery facilities if that licensed facility has applied for and received permission to process 'alternate feed'. The disposal of uranium-loaded resin is costly andmore » the cost to amend a uranium recovery license to accept alternate feed can be a strong disincentive to commercial uranium recovery facilities. In response to this issue, the NRC issued a Regulatory Issue Summary (RIS) to clarify the agency's policy that uranium-loaded resin from CWSs and mining operations can be processed by NRC- or Agreement State-licensed uranium recovery facilities without the need for an alternate feed license amendment when these resins are essentially the same, chemically and physically, to resins that licensed uranium recovery facilities currently use (i.e., equivalent feed). NRC staff is clarifying its current alternate feed policy to declare IX resins as equivalent feed. This clarification is necessary to alleviate a regulatory and financial burden on facilities that filter uranium using IX resin, such as CWSs and mine dewatering operations. Disposing of those resins in a licensed facility could be 40 to 50 percent of the total operations and maintenance (O and M) cost for a CWS. Allowing uranium recovery facilities to treat these resins without requiring a license amendment lowers O and M costs and captures a valuable natural resource. (authors)« less

PROCESS OF PREPARING A FLUORIDE OF TETRAVLENT URANIUM

DOEpatents

Wheelwright, E.J.

1959-02-17

A method is described for producing a fluoride salt pf tetravalent uranium suitable for bomb reduction to metallic uranium. An aqueous solution of uranyl nitrate is treated with acetic acid and a nitrite-suppressor and then contacted with metallic lead whereby uranium is reduced from the hexavalent to the tetravalent state and soluble lead acetate is formed. Sulfate ions are then added to the solution to precipitate and remove the lead values. Hydrofluoric acid and alkali metal ions are then added causing the formation of an alkali metal uranium double-fluoride in which the uranium is in the tetravalent state. After recovery, this precipitate is suitable for using in the limited production of metallic uranium.

A deposit model for carbonatite and peralkaline intrusion-related rare earth element deposits: Chapter J in Mineral deposit models for resource assessment

USGS Publications Warehouse

Verplanck, Philip L.; Van Gosen, Bradley S.; Seal, Robert R.; McCafferty, Anne E.

2014-01-01

The greatest environmental challenges associated with carbonatite and peralkaline intrusion-related rare earth element deposits center on the associated uranium and thorium. Considerable uncertainty exists around the toxicity of rare earth elements and warrants further investigation. The acid-generating potential of carbonatites and peralkaline intrusion-related deposits is low due to the dominance of carbonate minerals in carbonatite deposits, the presence of feldspars and minor calcite within the alkaline intrusion deposits, and only minor quantities of potentially acid-generating sulfides. Therefore, acid-drainage issues are not likely to be a major concern associated with these deposits. Uranium has the potential to be recovered as a byproduct, which would mitigate some of its environmental effects. However, thorium will likely remain a waste-stream product that will require management since progress is not being made towards the development of thorium-based nuclear reactors in the United States or other large scale commercial uses. Because some deposits are rich in fluorine and beryllium, these elements may be of environmental concern in certain locations.

Acceptance Test Data for Candidate AGR-5/6/7 TRISO Particle Batches BWXT Coater Batches 93165 93172 Defective IPyC Fraction and Pyrocarbon Anisotropy

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

Helmreich, Grant W.; Hunn, John D.; Skitt, Darren J.

2017-03-01

Coated particle fuel batches J52O-16-93165, 93166, 93168, 93169, 93170, and 93172 were produced by Babcock and Wilcox Technologies (BWXT) for possible selection as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR). Some of these batches may alternately be used as demonstration coated particle fuel for other experiments. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT lot J52R-16-69317 containing a mixture of 15.5%-enriched uranium carbide andmore » uranium oxide (UCO). The TRISO coatings consisted of four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μmnominal thickness. The TRISO-coated particle batches were sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batches were designated by appending the letter A to the end of the batch number (e.g., 93165A).« less

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

NASA Astrophysics Data System (ADS)

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.

Spatial variability and geochemistry of rare earth elements in soils from the largest uranium-phosphate deposit of Brazil.

PubMed

Cunha, Cleyton Saialy Medeiros; da Silva, Ygor Jacques Agra Bezerra; Escobar, Maria Eugenia Ortiz; do Nascimento, Clístenes Williams Araújo

2018-02-22

The Itataia uranium-phosphate deposit is the largest uranium reserve in Brazil. Rare earth elements (REEs) are commonly associated with phosphate deposits; however, there are no studies on the concentrations of REEs in soils of the Itataia deposit region. Thus, the objective of the research was to evaluate the concentration and spatial variability of REEs in topsoils of Itataia phosphate deposit region. In addition, the influence of soil properties on the geochemistry of REEs was investigated. Results showed that relatively high mean concentrations (mg kg -1 ) of heavy REEs (Gd 6.01; Tb 1.25; Ho 1.15; Er 4.05; Tm 0.64; Yb 4.61; Lu 0.65) were found in surface soils samples. Soil properties showed weak influence on the geochemical behavior of REEs in soils, except for the clay content. On the other hand, parent material characteristics, such as P and U, had strong influence on REEs concentrations. Spatial distribution patterns of REEs in soils are clearly associated with P and U contents. Therefore, geochemical surveys aiming at the delineation of ore-bearing zones in the region can benefit from our data. The results of this work reinforce the perspective for co-mining of P, U and REEs in this important P-U reserve.

Radioactive source materials in Los Estados Unidos de Venezuela

USGS Publications Warehouse

Wyant, Donald G.; Sharp, William N.; Rodriguez, Carlos Ponte

1953-01-01

This report summarizes the data available on radioactive source materials in Los Estados Unidos de Venezuela accumulated by geologists of the Direccions Tecnica de Geolgia and antecedent agencies prior to June 1951, and the writers from June to November 1951. The investigation comprised preliminary study, field examination, office studies, and the preparation of this report, in which the areas and localities examined are described in detail, the uranium potentialities of Venezuela are summarized, and recommendations are made. Preliminary study was made to select areas and rock types that were known or reported to be radioactive or that geologic experience suggests would be favorable host for uranium deposits, In the office, a study of gamma-ray well logs was started as one means of amassing general radiometric data and of rapidly scanning many of ye rocks in northern Venezuela; gamma-ray logs from about 140 representative wells were examined and their peaks of gamma intensity evaluated; in addition samples were analyzed radiometrically, and petrographically. Radiometic reconnaissance was made in the field during about 3 months of 1951, or about 12 areas, including over 100 localities in the State of Miranda, Carabobo, Yaracuy, Falcon, Lara, Trujillo, Zulia, Merida, Tachira, Bolivar, and Territory Delta Amacuro. During the course of the investigation, both in the filed and office, information was given about geology of uranium deposits, and in techniques used in prospecting and analysis. All studies and this report are designed to supplement and to strengthen the Direccion Tecnica de Geologias's program of investigation of radioactive source in Venezuela now in progress. The uranium potentialities of Los Estados de Venezuela are excellent for large, low-grade deposits of uraniferous phospahtic shales containing from 0.002 to 0.027 percent uranium; fair, for small or moderate-sized, low-grade placer deposits of thorium, rare-earth, and uranium minerals; poor, for high-grade hydrothermal pitchblende deposits; and highly possible for small, medium- to high-grade despots of carnotite-or copper-uranium bearing sandstone. Recommendations for the Venezuelan uranium program include 1) the systematic collection of a mass general radiometric data by examining sample collections, expanding the gamma-ray program, encouraging the use of Geiger counter by field geologists, and by enlisting the aid of the general public; 2) , the examination of specific areas or localities, chosen on the basis of geologic favorability from the results of the amassing of data, or obtained by hints and rumors; 3), the organization of a unit within the Direccion Tecnica de Geologica to direct, collection, and collate metric data. It is emphasized that to be most fruitful the program requires the application of sounds and imaginative geologic theory.

Advanced electrorefiner design

DOEpatents

Miller, W.E.; Gay, E.C.; Tomczuk, Z.

1996-07-02

A combination anode and cathode is described for an electrorefiner which includes a hollow cathode and an anode positioned inside the hollow cathode such that a portion of the anode is near the cathode. A retaining member is positioned at the bottom of the cathode. Mechanism is included for providing relative movement between the anode and the cathode during deposition of metal on the inside surface of the cathode during operation of the electrorefiner to refine spent nuclear fuel. A method is also disclosed which includes electrical power means selectively connectable to the anode and the hollow cathode for providing electrical power to the cell components, electrically transferring uranium values and plutonium values from the anode to the electrolyte, and electrolytically depositing substantially pure uranium on the hollow cathode. Uranium and plutonium are deposited at a liquid cathode together after the PuCl{sub 3} to UCl{sub 3} ratio is greater than 2:1. Slots in the hollow cathode provides close anode access for the liquid pool in the liquid cathode. 6 figs.

Advanced electrorefiner design

DOEpatents

Miller, William E.; Gay, Eddie C.; Tomczuk, Zygmunt

1996-01-01

A combination anode and cathode for an electrorefiner which includes a hollow cathode and an anode positioned inside the hollow cathode such that a portion of the anode is near the cathode. A retaining member is positioned at the bottom of the cathode. Mechanism is included for providing relative movement between the anode and the cathode during deposition of metal on the inside surface of the cathode during operation of the electrorefiner to refine spent nuclear fuel. A method is also disclosed which includes electrical power means selectively connectable to the anode and the hollow cathode for providing electrical power to the cell components, electrically transferring uranium values and plutonium values from the anode to the electrolyte, and electrolytically depositing substantially pure uranium on the hollow cathode. Uranium and plutonium are deposited at a liquid cathode together after the PuCl.sub.3 to UCl.sub.3 ratio is greater than 2:1. Slots in the hollow cathode provides close anode access for the liquid pool in the liquid cathode.

[Biosorption of Radionuclide Uranium by Deinococcus radiodurans].

PubMed

Yang, Jie; Dong, Fa-qin; Dai, Qun-wei; Liu, Ming-xue; Nie, Xiao-qin; Zhang, Dong; Ma, Jia-lin; Zhou, Xian

2015-04-01

As a biological adsorbent, Living Deinococcus radiodurans was used for removing radionuclide uranium in the aqueous solution. The effect factors on biosorption of radionuclide uranium were researched in the present paper, including solution pH values and initial uranium concentration. Meanwhile, the biosorption mechanism was researched by the method of FTIR and SEM/EDS. The results show that the optimum conditions for biosorption are as follows: pH = 5, co = 100 mg · L(-1) and the maximum biosorption capacity is up to 240 mgU · g(-1). According to the SEM results and EDXS analysis, it is indicated that the cell surface is attached by lots of sheet uranium crystals, and the main biosorpiton way of uranium is the ion exchange or surface complexation. Comparing FTIR spectra and FTIR fitting spectra before and after biosorption, we can find that the whole spectra has a certain change, particularly active groups (such as amide groups of the protein, hydroxy, carboxyl and phosphate group) are involved in the biosorption process. Then, there is a new peak at 906 cm(-1) and it is a stretching vibration peak of UO2(2+). Obviously, it is possible that as an anti radiation microorganism, Deinococcus radiodurans could be used for removing radionuclide uranium in radiation environment.

Uranium enrichment in lacustrine oil source rocks of the Chang 7 member of the Yanchang Formation, Erdos Basin, China

NASA Astrophysics Data System (ADS)

Yang, Hua; Zhang, Wenzheng; Wu, Kai; Li, Shanpeng; Peng, Ping'an; Qin, Yan

2010-09-01

The oil source rocks of the Chang 7 member of the Yanchang Formation in the Erdos Basin were deposited during maximum lake extension during the Late Triassic and show a remarkable positive uranium anomaly, with an average uranium content as high as 51.1 μg/g. Uranium is enriched together with organic matter and elements such as Fe, S, Cu, V and Mo in the rocks. The detailed biological markers determined in the Chang 7 member indicate that the lake water column was oxidizing during deposition of the Chang 7 member. However, redox indicators for sediments such as S 2- content, V/Sc and V/(V + Ni) ratios demonstrate that it was a typical anoxic diagenetic setting. The contrasted redox conditions between the water column and the sediment with a very high content of organic matter provided favorable physical and chemical conditions for syngenetic uranium enrichment in the oil source rocks of the Chang 7 member. Possible uranium sources may be the extensive U-rich volcanic ash that resulted from contemporaneous volcanic eruption and uranium material transported by hydrothermal conduits into the basin. The uranium from terrestrial clastics was unlike because uranium concentration was not higher in the margin area of basin where the terrestrial material input was high. As indicated by correlative analysis, the oil source rocks of the Chang 7 member show high gamma-ray values for radioactive well log data that reflect a positive uranium anomaly and are characterized by high resistance, low electric potential and low density. As a result, well log data can be used to identify positive uranium anomalies and spatial distribution of the oil source rocks in the Erdos Basin. The estimation of the total uranium reserves in the Chang 7 member attain 0.8 × 10 8 t.

ELECTROLYSIS OF THORIUM AND URANIUM

DOEpatents

Hansen, W.N.

1960-09-01

An electrolytic method is given for obtaining pure thorium, uranium, and thorium-uranium alloys. The electrolytic cell comprises a cathode composed of a metal selected from the class consisting of zinc, cadmium, tin, lead, antimony, and bismuth, an anode composed of at least one of the metals selected from the group consisting of thorium and uranium in an impure state, and an electrolyte composed of a fused salt containing at least one of the salts of the metals selected from the class consisting of thorium, uranium. zinc, cadmium, tin, lead, antimony, and bismuth. Electrolysis of the fused salt while the cathode is maintained in the molten condition deposits thorium, uranium, or thorium-uranium alloys in pure form in the molten cathode which thereafter may be separated from the molten cathode product by distillation.

Exploration for uranium deposits in the Spring Creek Mesa area, Montrose County, Colorado

USGS Publications Warehouse

Roach, Carl Houston

1954-01-01

4. The “ore-bearing sandstone” in the vicinity of relatively unoxidized ore deposits commonly contains sparse to abundant disseminated pyrite. In the vicinity of oxidized deposits it commonly contains abundant limonite spots and widespread limonite staining.

FUEL ELEMENTS AND METHOD OF MAKING

DOEpatents

Noland, R.A.; Marzano, C.

1958-08-19

A process is described of surface-impregnating bodies of metallic uranium with silicon. Silicon metal is added to or admixed with alkali metal selected from the group consisting of sodiunn, potassium, and sodiunnpotassium alloy. The uraniunn body is then immersed in the mixture obtained and the temperature is raised to between 425 and 600 deg C. The silicon is dissolved and deposits as a uranium-silicon compound on the uranium body.

Aerial gamma ray and magnetic survey: Powder River II Project, Gillette Quadrangle, Wyoming. Final report

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

Not Available

1979-04-01

The Gillette quadrangle in northeastern Wyoming and western South Dakota contains approximately equal portions of the Powder River Basin and the Black Hills Uplift. In these two structures, a relatively thick sequence of Paleozoic and Mesozoic strata represent nearly continuous deposition over the Precambrian basement complex. The Powder River Basin also contains a thick sequence of early Tertiary rocks which cover about 50% of the surface. A stratigraphic sequence from Upper Cretaceous to Precambrian is exposed in the Black Hills Uplift to the east. Magnetic data apparently illustrate the relative depth to the Precambrian crystalline rocks, but only weakly definemore » the boundary between the Powder River Basin and the Black Hills Uplift. The positions of some small isolated Tertiary intrusive bodies in the Black Hills Uplift are relatively well expressed. The Gillette quadrangle has been productive in terms of uranium mining, but its current status is uncertain. The producing uranium deposits occur within the Lower Cretaceous Inyan Kara Group and the Jurassic Morrison Formation in the Black Hills Uplift. Other prospects occur within the Tertiary Wasatch and Fort Union Formations in the Pumpkin Buttes - Turnercrest district, where it extends into the quadrangle from the Newcastle quadrangle to the south. These four formations, all predominantly nonmarine, contain all known uranium deposits in the Gillette quadrangle. A total of 108 groups of sample responses in the uranium window constitute anomalies as defined in Volume I. The anomalies are most frequently found in the Inyan Kara-Morrison, Wasatch and Fort Union Formations. Many anomalies occur over known mines or prospects. Others may result from unmapped uranium mines or areas where material other than uranium is mined. The remainder may relate to natural geologic features.« less

METHOD OF DISSOLVING REFRACTORY ALLOYS

DOEpatents

Helton, D.M.; Savolainen, J.K.

1963-04-23

This patent relates to the dissolution of alloys of uranium with zirconium, thorium, molybdenum, or niobium. The alloy is contacted with an anhydrous solution of mercuric chloride in a low-molecular-weight monohydric alcohol to produce a mercury-containing alcohol slurry. The slurry is then converted to an aqueous system by adding water and driving off the alcohol. The resulting aqueous slurry is electrolyzed in the presence of a mercury cathode to remove the mercury and produce a uranium-bearing aqueous solution. This process is useful for dissolving irradiated nuclear reactor fuels for radiochemical reprocessing by solvent extraction. In addition, zirconium-alloy cladding is selectively removed from uranium dioxide fuel compacts by this means. (AEC)

PROCESS OF PREPARING URANIUM-IMPREGNATED GRAPHITE BODY

DOEpatents

Kanter, M.A.

1958-05-20

A method for the fabrication of graphite bodies containing uniformly distributed uranium is described. It consists of impregnating a body of graphite having uniform porosity and low density with an aqueous solution of uranyl nitrate hexahydrate preferably by a vacuum technique, thereafter removing excess aqueous solution from the surface of the graphite, then removing the solvent water from the body under substantially normal atmospheric conditions of temperature and pressure in the presence of a stream of dry inert gas, and finally heating the dry impregnated graphite body in the presence of inert gas at a temperature between 800 and 1400 d C to convert the uranyl nitrate hexahydrate to an oxide of uranium.

Uranium in the Upper Cambrian black shale of Sweden

USGS Publications Warehouse

McKelvey, Vincent Ellis

1955-01-01

The Peltura zone of the Upper Cambrian black shales of Sweden contains about 0.02 percent uranium. Maximum amounts are present in rocks deposited in an embayment in the sea and in rocks in or closely adjacent to that part of the vertical sequence that contains maximum amounts of distillable oil, total organic matter, pyrite, and a black highly uraniferous kerogen called "kolm". Available data suggest that the precipitation of uranium is favored by a low redox potential and that the uranium in the shale matrix may be in fine-grained kolm.

Efficient Removal of Uranium from Aqueous Solution by Reduced Graphene Oxide-Zn0.5Ni0.5Fe2O4 Ferrite-Polyaniline Nanocomposite

NASA Astrophysics Data System (ADS)

Tran, Dat Quang; Pham, Hung Thanh; Do, Hung Quoc

2017-06-01

Reduced graphene oxide-Zn0.5Ni0.5Fe2O4 ferrite-polyaniline nanocomposite (RGO-ZNF-PANI) was synthesized by a three-step method. The prepared samples were characterized by x-ray diffraction, Raman spectroscopy, scanning electron microscopy and vibrating sample magnetometer. In particular, we found that this material is capable of effectively removing uranium from an aquatic environment. This is confirmed by our experimental results using the method of inductively coupled plasma mass spectrometry. Adsorptive behaviour of uranium from an aqueous solution on the RGO-ZNF-PANI nanocomposite was examined as a function of pH, contact time, and equilibrium. Uranium concentration was carried out by batch techniques. The adsorption isotherm agrees well with the Langmuir model, having a maximum sorption capacity of 1885 mg/g, at pH 5 and 25°C.

Field Testing of Downgradient Uranium Mobility at an In-Situ Recovery Uranium Mine

NASA Astrophysics Data System (ADS)

Reimus, P. W.; Clay, J. T.; Rearick, M.; Perkins, G.; Brown, S. T.; Basu, A.; Chamberlain, K.

2015-12-01

In-situ recovery (ISR) mining of uranium involves the injection of O2 and CO2 (or NaHCO3) into saturated roll-front deposits to oxidize and solubilize the uranium, which is then removed by ion exchange at the surface and processed into U3O8. While ISR is economical and environmentally-friendly relative to conventional mining, one of the challenges of extracting uranium by this process is that it leaves behind a geochemically-altered aquifer that is exceedingly difficult to restore to pre-mining geochemical conditions, a regulatory objective. In this research, we evaluated the ability of the aquifer downgradient of an ISR mining area to attenuate the transport of uranium and other problem constituents that are mobilized by the mining process. Such an evaluation can help inform both regulators and the mining industry as to how much restoration of the mined ore zone is necessary to achieve regulatory compliance at various distances downgradient of the mining zone even if complete restoration of the ore zone proves to be difficult or impossible. Three single-well push-pull tests and one cross-well test were conducted in which water from an unrestored, previously-mined ore zone was injected into an unmined ore zone that served as a geochemical proxy for the downgradient aquifer. In all tests, non-reactive tracers were injected with the previously-mined ore zone water to allow the transport of uranium and other constituents to be compared to that of the nonreactive species. In the single-well tests, it was shown that the recovery of uranium relative to the nonreactive tracers ranged from 12-25%, suggesting significant attenuation capacity of the aquifer. In the cross-well test, selenate, molybdate and metavanadate were injected with the unrestored water to provide information on the transport of these potentially-problematic anionic constituents. In addition to the species-specific transport information, this test provided valuable constraints on redox conditions within the system, as redox couples involving these species collectively bracket the predicted transition redox potential for the U(VI)/U(IV) couple. Reduction should provide much longer-lasting immobilization of constituents than adsorption, especially given the inherent reducing characteristics of roll-front systems.

Statistical analysis of soil geochemical data to identify pathfinders associated with mineral deposits: An example from the Coles Hill uranium deposit, Virginia, USA

USGS Publications Warehouse

Levitan, Denise M.; Zipper, Carl E.; Donovan, Patricia; Schreiber, Madeline E.; Seal, Robert; Engle, Mark A.; Chermak, John A.; Bodnar, Robert J.; Johnson, Daniel K.; Aylor, Joseph G.

2015-01-01

Soil geochemical anomalies can be used to identify pathfinders in exploration for ore deposits. In this study, compositional data analysis is used with multivariate statistical methods to analyse soil geochemical data collected from the Coles Hill uranium deposit, Virginia, USA, to identify pathfinders associated with this deposit. Elemental compositions and relationships were compared between the collected Coles Hill soil and reference soil samples extracted from a regional subset of a national-scale geochemical survey. Results show that pathfinders for the Coles Hill deposit include light rare earth elements (La and Ce), which, when normalised by their Al content, are correlated with U/Al, and elevated Th/Al values, which are not correlated with U/Al, supporting decoupling of U from Th during soil generation. These results can be used in genetic and weathering models of the Coles Hill deposit, and can also be applied to future prospecting for similar U deposits in the eastern United States, and in regions with similar geological/climatic conditions.

Geographical coincidence of high heat flow, high seismicity, and upwelling, with hydrocarbon deposits, phosphorites, evaporites, and uranium ores.

PubMed

Libby, L M; Libby, W F

1974-10-01

Oil deposits occur in deep sediments, and appear to be organic matter that has been transformed through the action of geothermal heat and pressure. Deep sediments, rich in biological remains, are created by ocean upwelling, caused in part by high geothermal heat flow through the sea bottom. Such regions correlate with enhanced seismic activity. We look for correlations of seismicity, high heat flux, petroleum, uranium, phosphates, and salts, deposited from abundant plant life. These may be useful in discovering more petroleum and coal. We estimate that the known world reserves of petroleum and coal are about 10(-4) of the total of buried biogenic carbon.

Geographical Coincidence of High Heat Flow, High Seismicity, and Upwelling, with Hydrocarbon Deposits, Phosphorites, Evaporites, and Uranium Ores

PubMed Central

Libby, L. M.; Libby, W. F.

1974-01-01

Oil deposits occur in deep sediments, and appear to be organic matter that has been transformed through the action of geothermal heat and pressure. Deep sediments, rich in biological remains, are created by ocean upwelling, caused in part by high geothermal heat flow through the sea bottom. Such regions correlate with enhanced seismic activity. We look for correlations of seismicity, high heat flux, petroleum, uranium, phosphates, and salts, deposited from abundant plant life. These may be useful in discovering more petroleum and coal. We estimate that the known world reserves of petroleum and coal are about 10-4 of the total of buried biogenic carbon. Images PMID:16592185

Uranium comminution age tested by the eolian deposits on the Chinese Loess Plateau

NASA Astrophysics Data System (ADS)

Li, Le; Liu, Xiangjun; Li, Tao; Li, Laifeng; Zhao, Liang; Ji, Junfeng; Chen, Jun; Li, Gaojun

2017-06-01

The 234U/238U ratio of fine particles can record the time since their separation from bed rock because of the disruption of uranium series equilibrium introduced by the recoil of daughter 234Th nuclei (precursor of 234U) out of particle surfaces during the decay of 238U. Application of the uranium comminution age method, which has great potential in tracing production and transportation of sediments is however complicated by the weathering dissolution of 234U depleted particle surfaces, the difficulty in determining the fraction of recoiled nuclei, and the precipitation of exogenetic 234U. Here we minimize these complications by using a newly developed precise size separation using electroformed sieve, and a chemical protocol that involves reductive and oxidative leaching. Eolian deposits collected from the Chinese Loess Plateau (CLP) were used to test the validity of our method. Possible effects of weathering dissolution were also evaluated by comparing samples with different weathering intensities. The results show decreasing 234U/238U ratios in fine eolian particles with increasing sedimentation age, agreeing well with the theoretical prediction of the comminution age model. This successful application of the uranium comminution age approach to the eolian deposits on the CLP is also aided by a stable dust source, the low weathering intensity, the lack of consolidation, and the well-defined age model of the deposits. A transportation time of 242 ± 18 ka was calculated for the eolian deposits, which indicates a long residence time, and thus extensive mixing, of the dust particles in source regions, partly explaining the stable and homogeneous composition of the eolian dust over glacial-interglacial cycles.

Origin of intraformational folds in the Jurassic Todilto Limestone, Ambrosia Lake uranium mining district, McKinley and Valencia counties, New Mexico

USGS Publications Warehouse

Green, M.W.

1982-01-01

The Todilto Limestone of Middle Jurassic age in the Ambrosia Lake uranium mining district of McKinley and Valencia Counties, New Mexico, is the host formation for numerous small- to medium-sized uranium deposits in joints, shear zones, and fractures within small- to large-scale intraformational folds. The folds probably were formed as a result of differential sediment loading when eolian sand dunes of the overlying Summerville Formation of Middle Jurassic age migrated over soft, chemically precipitated, lime muds of the Todilto shortly after their deposition in a regressive, mixed fresh and saline lacustrine or marine environment of deposition. Encroachment of Summerville eolian dunes over soft Todilto lime muds was apparently a local phenomenon and was restricted to postulated beltlike zones which trended radially across the Todilto coastline toward the receding body of water. Intraformational folding is believed to be confined to the pathways of individual eolian dunes or clusters of dunes within the dune belts. During the process of sediment loading by migrating sand dunes, layers of Todilto lime mud were differentially compacted, contorted, and dewatered, producing both small- and large-scale plastic deformation structures, including convolute laminations, mounds, rolls, folds, and small anticlines and synclines. With continued compaction and dewatering, the mud, in localized areas, reached a point of desaturation at which sediment plasticity was lost. Prolonged loading by overlying dune sands thus caused faulting, shearing, fracturing, and jointing of contorted limestone beds. These areas or zones of deformation within the limestone became the preferred sites of epigenetic uranium mineralization because of the induced transmissivity created by sediment rupture. Along most of the prograding Todilto coastline, adjacent to the eolian dune belts, both interdune and coastal sabkha environments dominated during Todilto-Summerville time. Sediments in coastal areas consisted mainly of clay, silt, sandy silt, and very fine-grained sand, which was apparently derived from the winnowing of the finer grained fraction of sediment from adjacent dune fields during periods of eolian activity. Most of the sabkha sediments were probably carried in airborne suspension to the low-lying, ground-water-saturated coastal areas, where they were deposited as relatively uniform blanket-like layers. Deposition of sabkha deposits was apparently slow and uniform over most of the Todilto coastal areas and crested only small-scale deformation features in underlying Todilto rocks. Large-scale deformation features and uranium deposits are both notably absent in the Todilto where it is overlain by finer textured sabkha deposits in the Summerville.

Results of exploration at the Old Leyden coal mine, Jefferson County, Colorado

USGS Publications Warehouse

Gude, A.J.; McKeown, F.A.

1953-01-01

Six diamond core holes totaling 2, 201 feet were drilled by the. U, S. Bureau of Mines under contract to the U. S. Atomic Energy Commission at the Old Leyden coal mine, Jefferson County, Colo. The holes were spotted on the basis of geologic mapping by the U. S. Geological survey and were drilled to explore the lateral and downward extent of a uranium-bearing coal and the associated carnotite deposits in the adjacent sandstone° The data obtained from the diamond-core holes helped to explain the geology and structural control of the deposit. The uranium is most abundant in a coal bed that in places has been brecciated by shearing. and then altered to a hard, dense, and silicified rock. The uraniferous coal is in the nearly vertical beds of the Laramie formation of Upper Cretaceous age. Small lenticular bodies of uraniferous material, 50 feet long, 25 to 30 feet wide, and 2 to 4 feet thick, occur at intervals in the coal and silicified coal over a strike length of about 800 feet. These bodies contain 0.10 to 0.50 percent uranium. Data obtained from the drilling indicate a discontinuous radioactive zone between these higher-grade bodies; assays of samples from the cores range from 0.001 to 0.10 percent uranium. All drill holes were probed by Survey and A. E. C. logging equipment and showed anomalies where the core assayed more than 0.005 percent uranium. Material of ore grade--0.10 percent uranium--was found in one core; the rock in the other five holes was of lower grade. The presence of the radioactive zone in all holes suggests, however, that uranium is distributed irregularly in a southerly plunging deposit which is exposed in the adit, on the outcrop, and in other diamond-drill holes that were put down by the lessee.

28 CFR 79.41 - Definitions.

Code of Federal Regulations, 2014 CFR

2014-07-01

... includes in situ lung cancers. (j) Readily available documentation means documents in the possession... or uranium mine worker means a person who operated or otherwise worked in a uranium mine. (f... means a chronic lung disease resulting from inhalation and deposition in the lung of particulate matter...

LIQUID PHASE SINTERING OF METALLIC CARBIDES

DOEpatents

Hammond, J.; Sease, J.D.

1964-01-21

An improved method is given for fabricating uranium carbide composites, The method comprises forming a homogeneous mixture of powdered uranium carbide, a uranium intermetallic compound which wets and forms a eutectic with said carbide and has a non-uranium component which has a relatively high vapor pressure at a temperature in the range 1200 to 1500 deg C, and an organic binder, pressing said mixture to a composite of desired green strength, and then vacuum sintering said composite at the eutectic forming temperature for a period sufficient to remove at least a portion of the non-uranium containing component of said eutectic. (AEC)

Forms of uranium associated to silica in the environment of the Nopal deposit (Mexico)

NASA Astrophysics Data System (ADS)

Allard, T.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Calas, G.; Fayek, M.

2011-12-01

The understanding of the processes that control the transfers of uranium in the environment is necessary for the safety assessement of nuclear waste repositories. In particular, several poorly ordered phases (e.g. Fe oxihydroxides) are expected to play an important role in trapping uranium from surface waters. Among them, natural systems containing amorphous silica are poorly documented. A former study from the environment of the Peny mine (France) showed the importance of silica in uranium speciation [1]. The Nopal uranium deposit is located in volcanic tuff from tertiary period. It hosted several hydrothermal alteration episodes responsible for clay minerals formation. A primary uranium mineralisation occurred in a breccia pipe, consisting in uraninite, subsequently altered in secondary uranium minerals among which several silicates. Eventually, opal was formed and coated uranyl silicates such as uranophane and weeksite [2], [3]. Opals also contain minor amounts of uranium. The Nopal deposit is still considered as a natural analogue of high level nuclear waste repository located in volcanic tuff. It may be used to reveal the low temperature conditions of trapping of uranium in systems devoid of iron oxides such as silica-containing ones. The aim of this study is then to determine the uranium speciation, and its possible complexity, associated to these opals that represent a late trapping episode. It will provide insights ranging from the micrometer scale of electron microscopies to the molecular scale provided by fluorescence spectroscopy. Three samples of green or yellow opals have been analysed by a combination of complementary tools including scanning electron microscopy (SEM) on cross-sections, transmission electron microscopy (TEM) on focused ion beam (FIB) films, cathodoluminescence and time-resolved laser fluorescence spectroscopy (TRLFS). Uranium speciation was found to be complex. We first evidence U-bearing microparticles of beta-uranophane Ca[(UO2)(SiO3OH)]2(H2O)5 and apatite Ca5(PO4)3(OH,Cl,F) containing minor amounts of uranium. Uranophane was formed prior to opal and coated by it. However the major part of uranium is concentrated in Ca-U-enriched zones with a Ca:U ratio of 1:1 and displaying botryoidal features. The exact nature of Ca-U species in these zones was not specified but TEM, cathodoluminescence and TRLFS analyses suggest the presence of Cam-(UO2)m-(O/OH/H2O)n complexes adsorbed or incorporated in opal. These results will be discussed in terms of chemical conditions that prevailed during U incorporation and compared to other known U-Si environmental systems, including the Peny system (France). [1] Allard, T. et al. (1999) Chem. Geol., 158, 81-103 [2] Calas, G. et al. (2008) Terra Nova, 20, 206-212. [3] Schindler, M. et al. (2010) Geochim. Cosmochim. Ac, 74, 187-202.

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

PubMed

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

2018-06-01

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

Spectroscopic studies of uranium species for environmental decontamination applications

NASA Astrophysics Data System (ADS)

Eng, Charlotte

After the Cold War, Department of Energy began to concentrate its efforts on cleanup of former nuclear material processing facilities, especially uranium-contaminated groundwater and soil. This research aims to study uranium association to both organic and inorganic compounds found in the contaminated environment in the hopes that the information gathered can be applied to the development and optimization of cost-effective remediation techniques. Spectroscopic and electrochemical methods will be employed to examine the behavior of uranium in given conditions to further our understanding of its impact on the environment. Uranium found in groundwater and soil bind with various ligands, especially organic ligands present in the environment due to natural sources (e.g. metabolic by-products or degradation of plants and animals) or man-made sources (e.g. chelating agents used in operating or cleanup of uranium processing facilities). We selected reasonable analogs of naturally occurring matter and studied their structure, chemical and electrochemical behavior and found that the structure of uranyl complexes depends heavily on the nature of the ligand and environmental factors such as pH. Association of uranium-organic complexes with anaerobic bacteria, Clostridium sp. was studied to establish if the bacteria can effectively bioreduce uranium while going through normal bacterial activity. It was found that the nature of the organic ligand affected the bioavailability and toxicity of the uranium on the bacteria. In addition, we have found that the type of iron corrosion products and uranyl species present on the surface of corroded steel depended on various environmental factors, which subsequently affected the removal rate of uranium by a citric acid/hydrogen peroxide/deionized water cleaning process. The method was found to remove uranium from only the topmost corrosion layers and residual uranium could be found (a) deeper in the corrosion layers where it is occluded by the steel corrosion products or (b) in areas where the dissolved uranium/iron species, the products generated by the dissolution power of citric acid, was not properly rinsed away.

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

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

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

1996-12-31

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

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

USGS Publications Warehouse

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

1977-01-01

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

Navajo Nation: Cleaning Up Abandoned Uranium Mines

EPA Pesticide Factsheets

This site provides information about the progress of EPA's cleanup of abandoned uranium mines on Navajo and Hopi lands and in other areas of Arizona and New Mexico, including health impacts, major enforcement and removal milestones, and community actions.

THE MARY KATHLEEN URANIUM PROJECT

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

Nelson, A.

1960-02-01

A description is given of uranium mining and milling methods at the Mary Kathleen Mine in the Cloncurry-Mt. Isa district of Queensland, Australia. The discovery of this property and its development are outlined. The deposit cecurs in highly altered meta-sediments in the corella beds of lower proterozoic age. Because of the considerable internal waste in the deposit, it was necessary to devise a selective mining method which would keep dilution to the lowest possible level. The mining, haulage and handling, premilling program, drilling, and blasting are discussed. (M.C.G.)

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

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

None

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

Uranium- and thorium-bearing pegmatites of the United States

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

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

1980-04-01

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

The nucleation and growth of uranium on the basal plane of graphite studied by scanning tunneling microscopy

NASA Astrophysics Data System (ADS)

Tench, R. J.

1992-11-01

For the first time, nanometer scale uranium clusters were created on the basal plane of highly oriented pyrolytic graphite by laser ablation under ultra-high vacuum conditions. The physical and chemical properties of these clusters were investigated by scanning tunneling microscopy (STM) as well as standard surface science techniques. Auger electron and X-ray photoelectron spectroscopies found the uranium deposit to be free of contamination and showed that no carbide had formed with the underlying graphite. Clusters with sizes ranging from 42 to 630 sq A were observed upon initial room temperature deposition. Surface diffusion of uranium was observed after annealing the substrate above 800 K, as evidenced by the decreased number density and the increased size of the clusters. Preferential depletion of clusters on terraces near step edges as a result of annealing was observed. The activation energy for diffusion deduced from these measurements was found to be 15 Kcal/mole. Novel formation of ordered uranium thin films was observed for coverages greater than two monolayers after annealing above 900 K. These ordered films displayed islands with hexagonally faceted edges rising in uniform step heights characteristic of the unit cell of the P-phase of uranium. In addition, atomic resolution STM images of these ordered films indicated the formation of the (beta)-phase of uranium. The chemical properties of these surfaces were investigated and it was shown that these uranium films had a reduced oxidation rate in air as compared to bulk metal and that STM imaging in air induced a polarity-dependent enhancement of the oxidation rate.

Developing depleted uranium and gold cocktail hohlraums for the National Ignition Facility

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

Wilkens, H. L.; Nikroo, A.; Wall, D. R.

2007-05-15

Fusion ignition experiments are planned to begin at the National Ignition Facility (NIF) [J. A. Paisner, E. M. Campbell, and W. J. Hogan, Fusion Technol. 26, 755 (1994)] using the indirect drive configuration [J. D. Lindl, P. Amendt, R. L. Berger, S. G. Glendinning, S. H. Glenzer, S. W. Haan, R. L, Kauffman, O. L. Landen, and L. J. Suter, Phys. Plasmas 11, 339 (2004)]. Although the x-ray drive in this configuration is highly symmetric, energy is lost in the conversion process due to x-ray penetration into the hohlraum wall. To mitigate this loss, depleted uranium is incorporated into themore » traditional gold hohlraum to increase the efficiency of the laser to x-ray energy conversion by making the wall more opaque to the x rays [H. Nishumura, T. Endo, H. Shiraga, U. Kato, and S. Nakai, Appl. Phys. Lett. 62, 1344 (1993)]. Multilayered depleted uranium (DU) and gold hohlraums are deposited by sputtering by alternately rotating a hohlraum mold in front of separate DU and Au sources to build up multilayers to the desired wall thickness. This mold is removed to leave a freestanding hohlraum half; two halves are used to assemble the complete NIF hohlraum to the design specifications. In practice, exposed DU oxidizes in air and other chemicals necessary to hohlraum production, so research has focused on developing a fabrication process that protects the U from damaging environments. This paper reports on the most current depleted uranium and gold cocktail hohlraum fabrication techniques, including characterization by Auger electron spectroscopy, which is used to verify sample composition and the amount of oxygen uptake over time.« less

Development of solid materials for UF 6 sampling: FY16 Annual Report

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

Smith, Nicholas; Savina, Joseph; Hebden, Andrew

2016-10-31

A handheld implementation of the ABACC-developed Cristallini method, which captures uranium hexafluoride samples as an inert salt, was organized in FY17 and succeeded in demonstrating the handheld sampler concept with reactive hexafluoride gases. The Cristallini method relies on the use of a hydrated substrate to react the incoming hexafluoride resulting in the formation of a stable uranyl fluoride salt. The Cristallini method has been demonstrated as a facility modification installed near the sampling tap of a gas centrifuge enrichment plant. While very successful in reducing the hazards of uranium hexafluoride sample, the method still takes a considerable amount of timemore » and can only be used in facilities where the apparatus has been installed; this arrangement generally prohibits the sampling of filled cylinders that have already exited the facility and have been deposited in the on-site tank storage yard. The handheld unit under development will allow the use of the Cristallini method at facilities that have not been converted as well as tanks in the storage yard. The handheld system utilizes an active vacuum system, rather than a passive vacuum system in the facility setup, to drive the uranium hexafluoride onto the adsorbing media. The handheld unit will be battery operated for fully autonomous operation and will include onboard pressure sensing and flushing capability. To date, the system concept of operations was demonstrated with tungsten hexafluoride that showed the active vacuum pump with multiple cartridges of adsorbing media was viable. Concurrently, the hardened prototype system was developed and tested; removable sample cartridges were developed (the only non-COTS component to date); and preparations were made for uranium tests and a domestic field test.« less

JACKETING URANIUM

DOEpatents

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

1959-07-14

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

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

USGS Publications Warehouse

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

1955-01-01

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

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

USGS Publications Warehouse

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

1959-01-01

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

URANIUM SEPARATION PROCESS

DOEpatents

Lyon, W.L.

1962-04-17

A method of separating uranium oxides from PuO/sub 2/, ThO/sub 2/, and other actinide oxides is described. The oxide mixture is suspended in a fused salt melt and a chlorinating agent such as chlorine gas or phosgene is sparged through the suspension. Uranium oxides are selectively chlorinated and dissolve in the melt, which may then be filtered to remove the unchlorinated oxides of the other actinides. (AEC)

The Olympic Dam copper-uranium-gold deposit, Roxby Downs, South Australia

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

Roberts, D.E.; Hudson, G.R.T.

1983-08-01

The Olympic Dam copper-uranium-gold deposit appears to be a new type of strata-bound sediment-hosted ore deposit. It is located 650 km north-northwest of Adelaide in South Australia and was discovered in 1975. It has an areal extent exceeding 20 km/sup 2/ with vertical thicknesses of mineralization up to 350 m. The deposit is estimated to contain in excess of 2,000 million metric tons of mineralized material with an average grade of 1.6 percent copper, 0.06 percent uranium oxide, and 0.6 g/metric ton gold. The deposit occurs in the basement beneath 350 m of unmineralized, flat-lying Adelaidean (late Proterozoic) to Cambrianmore » sediments in the Stuart shelf region of South Australia. The host rocks of the deposit are unmetamorphosed and are probably younger than 1,580 m.y. The deposit is spatially related to coincident gravity and magnetic anomalies and the intersection of west-northwest- and north-northwest-trending lineaments. The Proterozoic sediments comprising the local basement sequence are predominantly sedimentary breccias ranging from matrix-poor granite breccias to matrix-rich polymict breccias containing clasts of a variety of rock types. This sequence is over 1 km thick and has been divided into two main units--the Olympic Dam Formation and the Greenfield Formation. The Olympic Dam Formation has five members, three of which are matrix rich. The Greenfield Formation has three members, the lower two being very hematite rich while the upper has a significant volcanic component. Pervasive hematite, chlorite, and sericite alteration of varying intensity affects all the basement sequence.« less

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

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

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, particle size, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population andmore » composition, which mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfatereducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. The results of this study suggest that reductive immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

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

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population and composition, whichmore » mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. Lastly, the results of this study suggest that immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

DOE PAGES

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.; ...

2016-12-29

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy's Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments' mineralogy, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population and composition, whichmore » mainly determines the system's performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, and the sediments' propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments' ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. Lastly, the results of this study suggest that immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less

Heat deposition analysis for the High Flux Isotope Reactor’s HEU and LEU core models

DOE PAGES

Davidson, Eva E.; Betzler, Benjamin R.; Chandler, David; ...

2017-08-01

The High Flux Isotope Reactor at Oak Ridge National Laboratory is an 85 MW th pressurized light-water-cooled and -moderated flux-trap type research reactor. The reactor is used to conduct numerous experiments, advancing various scientific and engineering disciplines. As part of an ongoing program sponsored by the US Department of Energy National Nuclear Security Administration Office of Material Management and Minimization, studies are being performed to assess the feasibility of converting the reactor’s highly enriched uranium fuel to low-enriched uranium fuel. To support this conversion project, reference models with representative experiment target loading and explicit fuel plate representation were developed andmore » benchmarked for both fuels to (1) allow for consistent comparison between designs for both fuel types and (2) assess the potential impact of low-enriched uranium conversion. These high-fidelity models were used to conduct heat deposition analyses at the beginning and end of the reactor cycle and are presented herein. This article (1) discusses the High Flux Isotope Reactor models developed to facilitate detailed heat deposition analyses of the reactor’s highly enriched and low-enriched uranium cores, (2) examines the computational approach for performing heat deposition analysis, which includes a discussion on the methodology for calculating the amount of energy released per fission, heating rates, power and volumetric heating rates, and (3) provides results calculated throughout various regions of the highly enriched and low-enriched uranium core at the beginning and end of the reactor cycle. These are the first detailed high-fidelity heat deposition analyses for the High Flux Isotope Reactor’s highly enriched and low-enriched core models with explicit fuel plate representation. Lastly, these analyses are used to compare heat distributions obtained for both fuel designs at the beginning and end of the reactor cycle, and they are essential for enabling comprehensive thermal hydraulics and safety analyses that require detailed estimates of the heat source within all of the reactor’s fuel element regions.« less

TECHNOLOGIES FOR RADON AND RADIONUCLIDE REMOVAL

EPA Science Inventory

This paper provides a summary of the technologies that are currently being used to remove radionuclides from drinking water. The radionuclides that are featured are the radionuclides currently regulated by EPA; radium, radon and uranium. Tehnologies effective for removal of eac...

URANIUM RECOVERY AND PURIFICATION PROCESS AND PRODUCTION OF HIGH PURITY URANIUM TETRAFLUORIDE

DOEpatents

Bailes, R.H.; Long, R.S.; Grinstead, R.R.

1957-09-17

A process is described wherein an anionic exchange technique is employed to separate uramium from a large variety of impurities. Very efficient and economical purification of contamimated uranium can be achieved by treatment of the contaminated uranium to produce a solution containing a high concentration of chloride. Under these conditions the uranium exists as an aniomic chloride complex. Then the uranium chloride complex is adsorbed from the solution on an aniomic exchange resin, whereby a portion of the impurities remain in the solution and others are retained with the uramium by the resin. The adsorbed impurities are then removed by washing the resin with pure concentrated hydrochloric acid, after which operation the uranium is eluted with pure water yielding an acidic uranyl chloride solution of high purity.

Modeling of the dispersion of depleted uranium aerosol.

PubMed

Mitsakou, C; Eleftheriadis, K; Housiadas, C; Lazaridis, M

2003-04-01

Depleted uranium is a low-cost radioactive material that, in addition to other applications, is used by the military in kinetic energy weapons against armored vehicles. During the Gulf and Balkan conflicts concern has been raised about the potential health hazards arising from the toxic and radioactive material released. The aerosol produced during impact and combustion of depleted uranium munitions can potentially contaminate wide areas around the impact sites or can be inhaled by civilians and military personnel. Attempts to estimate the extent and magnitude of the dispersion were until now performed by complex modeling tools employing unclear assumptions and input parameters of high uncertainty. An analytical puff model accommodating diffusion with simultaneous deposition is developed, which can provide a reasonable estimation of the dispersion of the released depleted uranium aerosol. Furthermore, the period of the exposure for a given point downwind from the release can be estimated (as opposed to when using a plume model). The main result is that the depleted uranium mass is deposited very close to the release point. The deposition flux at a couple of kilometers from the release point is more than one order of magnitude lower than the one a few meters near the release point. The effects due to uncertainties in the key input variables are addressed. The most influential parameters are found to be atmospheric stability, height of release, and wind speed, whereas aerosol size distribution is less significant. The output from the analytical model developed was tested against the numerical model RPM-AERO. Results display satisfactory agreement between the two models.

Uranium metallogenesis of the peraluminous leucogranite from the Pontivy-Rostrenen magmatic complex (French Armorican Variscan belt): the result of long-term oxidized hydrothermal alteration during strike-slip deformation

NASA Astrophysics Data System (ADS)

Ballouard, C.; Poujol, M.; Mercadier, J.; Deloule, E.; Boulvais, P.; Baele, J. M.; Cuney, M.; Cathelineau, M.

2018-06-01

In the French Armorican Variscan belt, most of the economically significant hydrothermal U deposits are spatially associated with peraluminous leucogranites emplaced along the south Armorican shear zone (SASZ), a dextral lithospheric scale wrench fault that recorded ductile deformation from ca. 315 to 300 Ma. In the Pontivy-Rostrenen complex, a composite intrusion, the U mineralization is spatially associated with brittle structures related to deformation along the SASZ. In contrast to monzogranite and quartz monzodiorite (3 < U < 9 ppm; Th/U > 3), the leucogranite samples are characterized by highly variable U contents ( 3 to 27 ppm) and Th/U ratios ( 0.1 to 5) suggesting that the crystallization of magmatic uranium oxide in the more evolved facies was followed by uranium oxide leaching during hydrothermal alteration and/or surface weathering. U-Pb dating of uranium oxides from the deposits reveals that they mostly formed between ca. 300 and 270 Ma. In monzogranite and quartz monzodiorite, apatite grains display magmatic textures and provide U-Pb ages of ca. 315 Ma reflecting the time of emplacement of the intrusions. In contrast, apatite grains from the leucogranite display textural, geochemical, and geochronological evidences for interaction with U-rich oxidized hydrothermal fluids contemporaneously with U mineralizing events. From 300 to 270 Ma, infiltration of surface-derived oxidized fluids leached magmatic uranium oxide from fertile leucogranite and formed U deposits. This phenomenon was sustained by brittle deformation and by the persistence of thermal anomalies associated with U-rich granitic bodies.

Geology and recognition criteria for uranium deposits of the quartz-pebble conglomerate type. Final report

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

Button, A.; Adams, S.S.

1981-03-01

This report is concerned with Precambrian uraniferous conglomerates. This class of deposit has been estimated to contain between approximately 16 and 35 percent of the global uranium reserve in two rather small areas, one in Canada, the other in South Africa. Similar conglomerates, which are often gold-bearing, are, however, rather widespread, being found in parts of most Precambrian shield areas. Data have been synthesized on the geologic habitat and character of this deposit type. The primary objective has been to provide the most relevant geologic observations in a structural fashion to allow resource studies and exploration to focus on themore » most prospective targets in the shortest possible time.« less

Uranium-series dated authigenic carbonates and acheulian sites in southern Egypt

USGS Publications Warehouse

Szabo, B. J.; McHugh, W.P.; Schaber, G.G.; Haynes, C.V.; Breed, C.S.

1989-01-01

Field investigations in southern Egypt have yielded Acheulian artifacts in situ in authigenic carbonate deposits (CaCO3-cemented alluvium) along the edges of nowaggraded paleovalleys (Wadi Arid and Wadi Safsaf). Uranium-series dating of 25 carbonate samples from various localities as far apart as 70 kilometers indicates that widespread carbonate deposition occurred about 45, 141 and 212 ka (thousand years ago). Most of the carbonate appears to have been precipitated from groundwater, which suggests that these three episodes of deposition may be related to late Pleistocene humid climates that facilitated human settlement in this now hyperarid region. Carbonate cements from sediments containing Acheulian artifacts provide a minimum age of 212 ka for early occupation of the paleovalleys.

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

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

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

1981-08-01

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

QUANTITATIVE DETERMINATION OF THE URANIUM CONTENT OF URANIUM ORES TECHNOLOGICAL PRODUCTS BY ION EXCHANGE-COMPLEXON SEPARATION (in Hungarian)

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

Fodor, M.

An ion exchange-complexion separation meihod was developed for the removal of interfering elements in the determination of the uranium content of recovery solutions. By adding (ethylenediamine)tetraacetic acid to the solution, most of the interfering elements can be brought into an anionic complex. Adjusting the soluiion to pH 7 and letting it pass through an Amberlite IRC-50 type cation exchanger of hydrogen form, the uranium remains on the column whereas the interfering elements pass into the effluent. The method was successfully applied in analyzing the recovery solutions of uranium ores. (auth)

MANUFACTURE OF UF$sub 4$

DOEpatents

Calcott, W.S.

1959-10-13

The manufacture of uranium tetrafluoride from urarium dioxide is described. Uranium dioxide is heated to about 500 deg C in a reactor. Anhydrous hydrogen fluoride is passed through the reactor in contact with uranium dioxide for several hours, the flow of hydrogen fluoride is discontinued, and hydrogen passed through the reactor for less than an hour. The flow of hydrogen fluoride is resumed for several hours, and then nitrogen is passed for a few minutes to expel unreacted hydrogen fluoride as water vapor. The reactor is cooled to room temperature and the uranium tetrafluoride removed.

The role of the thermal convection of fluids in the formation of unconformity-type uranium deposits: the Athabasca Basin, Canada

NASA Astrophysics Data System (ADS)

Pek, A. A.; Malkovsky, V. I.

2017-05-01

In the global production of uranium, 18% belong to the unconformity-type Canadian deposits localized in the Athabasca Basin. These deposits, which are unique in terms of their ore quality, were primarily studied by Canadian and French scientists. They have elaborated the diagenetic-hydrothermal hypothesis of ore formation, which suggests that (1) the deposits were formed within a sedimentary basin near an unconformity surface dividing the folded Archean-Proterozoic metamorphic basement and a gently dipping sedimentary cover, which is not affected by metamorphism; (2) the spatial accommodation of the deposits is controlled by the rejuvenated faults in the basement at their exit into the overlying sedimentary sequence; the ore bodies are localized above and below the unconformity surface; (3) the occurrence of graphite-bearing rocks is an important factor in controlling the local structural mineralization; (4) the ore bodies are the products of uranium precipitation on a reducing barrier. The mechanism that drives the circulation of ore-forming hydrothermal solutions has remained one of the main unclear questions in the general genetic concept. The ore was deposited above the surface of the unconformity due to the upflow discharge of the solution from the fault zones into the overlying conglomerate and sandstone. The ore formation below this surface is a result of the downflow migration of the solutions along the fault zones from sandstone into the basement rocks. A thermal convective system with the conjugated convection cells in the basement and sedimentary fill of the basin may be a possible explanation of why the hydrotherms circulate in the opposite directions. The results of our computations in the model setting of the free thermal convection of fluids are consistent with the conceptual reasoning about the conditions of the formation of unique uranium deposits in the Athabasca Basin. The calculated rates of the focused solution circulation through the fault zones in the upflow and downflow branches of a convection cell allow us to evaluate the time of ore formation up to the first hundreds of thousands years.

Coated Metal Articles and Method of Making

DOEpatents

Boller, Ernest R.; Eubank, Lowell D.

2004-07-06

The method of protectively coating metallic uranium which comprises dipping the metallic uranium in a molten alloy comprising about 20-75% of copper and about 80-25% of tin, dipping the coated uranium promptly into molten tin, withdrawing it from the molten tin and removing excess molten metal, thereupon dipping it into a molten metal bath comprising aluminum until it is coated with this metal, then promptly withdrawing it from the bath.

SURFACE TREATMENT OF METALLIC URANIUM

DOEpatents

Gray, A.G.; Schweikher, E.W.

1958-05-27

The treatment of metallic uranium to provide a surface to which adherent electroplates can be applied is described. Metallic uranium is subjected to an etchant treatment in aqueous concentrated hydrochloric acid, and the etched metal is then treated to dissolve the resulting black oxide and/or chloride film without destroying the etched metal surface. The oxide or chloride removal is effected by means of moderately concentrated nitric acid in 3 to 20 seconds.

Three-dimensional inversion of magnetotelluric data for mineral exploration: An example from the McArthur River uranium deposit, Saskatchewan, Canada

NASA Astrophysics Data System (ADS)

Farquharson, Colin G.; Craven, James A.

2009-08-01

Shallow exploration targets are becoming scarce, meaning interest is turning towards deeper targets. The magnetotelluric method has the necessary depth capability, unlike many of the controlled-source electromagnetic prospecting techniques traditionally used. The geological setting of ore deposits is usually complex, requiring three-dimensional Earth models for their representation. An example of the applicability of three-dimensional inversion of magnetotelluric data to mineral exploration is presented here. Inversions of an audio-magnetotelluric data-set from the McArthur River uranium mine in the Athabasca Basin were carried out. A sub-set comprising data from eleven frequencies distributed over almost three decades was inverted. The form of the data used in the inversion was impedance. All four elements of the tensor were included. No decompositions of the data were done, nor rotation to a preferred strike direction, nor correction for static shifts. The inversions were successful: the observations were adequately reproduced and the main features in the conductivity model corresponded to known geological features. These included the graphitic basement fault along which the McArthur River uranium deposit is located.

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

NASA Astrophysics Data System (ADS)

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

2014-04-01

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

Conversion of depleted uranium hexafluoride to a solid uranium compound

DOEpatents

Rothman, Alan B.; Graczyk, Donald G.; Essling, Alice M.; Horwitz, E. Philip

2001-01-01

A process for converting UF.sub.6 to a solid uranium compound such as UO.sub.2 and CaF. The UF.sub.6 vapor form is contacted with an aqueous solution of NH.sub.4 OH at a pH greater than 7 to precipitate at least some solid uranium values as a solid leaving an aqueous solution containing NH.sub.4 OH and NH.sub.4 F and remaining uranium values. The solid uranium values are separated from the aqueous solution of NH.sub.4 OH and NH.sub.4 F and remaining uranium values which is then diluted with additional water precipitating more uranium values as a solid leaving trace quantities of uranium in a dilute aqueous solution. The dilute aqueous solution is contacted with an ion-exchange resin to remove substantially all the uranium values from the dilute aqueous solution. The dilute solution being contacted with Ca(OH).sub.2 to precipitate CaF.sub.2 leaving dilute NH.sub.4 OH.

Porous membrane electrochemical cell for uranium and transuranic recovery from molten salt electrolyte

DOEpatents

Willit, James L [Ratavia, IL

2007-09-11

An improved process and device for the recovery of the minor actinides and the transuranic elements (TRU's) from a molten salt electrolyte. The process involves placing the device, an electrically non-conducting barrier between an anode salt and a cathode salt. The porous barrier allows uranium to diffuse between the anode and cathode, yet slows the diffusion of uranium ions so as to cause depletion of uranium ions in the catholyte. This allows for the eventual preferential deposition of transuranics present in spent nuclear fuel such as Np, Pu, Am, Cm. The device also comprises an uranium oxidation anode. The oxidation anode is solid uranium metal in the form of spent nuclear fuel. The spent fuel is placed in a ferric metal anode basket which serves as the electrical lead or contact between the molten electrolyte and the anodic uranium metal.

Porous membrane electrochemical cell for uranium and transuranic recovery from molten salt electrolyte

DOEpatents

Willit, James L [Batavia, IL

2010-09-21

An improved process and device for the recovery of the minor actinides and the transuranic elements (TRU's) from a molten salt electrolyte. The process involves placing the device, an electrically non-conducting barrier between an anode salt and a cathode salt. The porous barrier allows uranium to diffuse between the anode and cathode, yet slows the diffusion of uranium ions so as to cause depletion of uranium ions in the catholyte. This allows for the eventual preferential deposition of transuranics present in spent nuclear fuel such as Np, Pu, Am, Cm. The device also comprises an uranium oxidation anode. The oxidation anode is solid uranium metal in the form of spent nuclear fuel. The spent fuel is placed in a ferric metal anode basket which serves as the electrical lead or contact between the molten electrolyte and the anodic uranium metal.

Method for fabricating laminated uranium composites

DOEpatents

Chapman, L.R.

1983-08-03

The present invention is directed to a process for fabricating laminated composites of uranium or uranium alloys and at least one other metal or alloy. The laminated composites are fabricated by forming a casting of the molten uranium with the other metal or alloy which is selectively positioned in the casting and then hot-rolling the casting into a laminated plate in or around which the casting components are metallurgically bonded to one another to form the composite. The process of the present invention provides strong metallurgical bonds between the laminate components primarily since the bond disrupting surface oxides on the uranium or uranium alloy float to the surface of the casting to effectively remove the oxides from the bonding surfaces of the components.

[Effect of the chelator BPCBG on the decorporation of uranium in vivo and uranium-induced damage of human renal tubular epithelial cells in vitro].

PubMed

Bao, Yi-zhong; Wang, Dan; Hu, Yu-xing; Xu, Ai-hong; Sun, Mei-zhen; Chen, Hong-hong

2011-11-01

This study is to assess the efficacy of BPCBG on the decorporation of uranium (VI) and protecting human renal proximal tubular epithelial cells (HK-2) against uranium-induced damage. BPCBG at different doses was injected intramuscularly to male SD rats immediately after a single intraperitoneal injection of UO2(CH3COO)2. Twenty-four hours later uranium contents in urine, kidneys and femurs were measured by ICP-MS. After HK-2 cells were exposed to UO2(CH3COO)2 immediately or for 24 h followed by BPCBG treatment at different doses for another 24 or 48 h, the uranium contents in HK-2 cells were measured by ICP-MS, the cell survival was assayed by cell counting kit-8 assay, formation of micronuclei was determined by the cytokinesis-block (CB) micronucleus assay and the production of intracellular reactive oxygen species (ROS) was detected by 2',7'-dichlorofluorescin diacetate (DCFH-DA) oxidation. DTPA-CaNa3 was used as control. It was found that BPCBG at dosages of 60, 120, and 600 micromol kg(-1) resulted in 37%-61% increase in 24 h-urinary uranium excretion, and significantly decreased the amount of uranium retention in kidney and bone to 41%-31% and 86%-42% of uranium-treated group, respectively. After HK-2 cells that had been pre-treated with UO2(CH3COO)2 for 24 h were treated with the chelators for another 24 h, 55%-60% of the intracellular uranium was removed by 10-250 micromol L(-1) of BPCBG. Treatment of uranium-treated HK-2 cells with BPCBG significantly enhanced the cell survival, decreased the formation of micronuclei and inhibited the production of intracellular ROS. Although DTPA-CaNa3 markedly reduced the uranium retention in kidney of rats and HK-2 cells, its efficacy of uranium removal from body was significantly lower than that of BPCBG and it could not protect uranium-induced cell damage. It can be concluded that BPCBG effectively decorporated the uranium from UO2(CH3COO)2-treated rats and HK-2 cells, which was better than DTPA-CaNa3. It could also scavenge the uranium-induced intracellular ROS and protect against the uranium-induced cell damage. BPCBG is worth further investigation.

A graphene oxide/amidoxime hydrogel for enhanced uranium capture

PubMed Central

Wang, Feihong; Li, Hongpeng; Liu, Qi; Li, Zhanshuang; Li, Rumin; Zhang, Hongsen; Liu, Lianhe; Emelchenko, G. A.; Wang, Jun

2016-01-01

The efficient development of selective materials for the recovery of uranium from nuclear waste and seawater is necessary for their potential application in nuclear fuel and the mitigation of nuclear pollution. In this work, a graphene oxide/amidoxime hydrogel (AGH) exhibits a promising adsorption performance for uranium from various aqueous solutions, including simulated seawater. We show high adsorption capacities (Qm = 398.4 mg g−1) and high % removals at ppm or ppb levels in aqueous solutions for uranium species. In the presence of high concentrations of competitive ions such as Mg2+, Ca2+, Ba2+ and Sr2+, AGH displays an enhanced selectivity for uranium. For low uranium concentrations in simulated seawater, AGH binds uranium efficiently and selectively. The results presented here reveal that the AGH is a potential adsorbent for remediating nuclear industrial effluent and adsorbing uranium from seawater. PMID:26758649

Influence of terrestrial radionuclides on environmental gamma exposure in a uranium deposit in Paraíba, Brazil.

PubMed

Araújo Dos Santos Júnior, José; Dos Santos Amaral, Romilton; Simões Cezar Menezes, Rômulo; Reinaldo Estevez Álvarez, Juan; Marques do Nascimento Santos, Josineide; Herrero Fernández, Zahily; Dias Bezerra, Jairo; Antônio da Silva, Alberto; Francys Rodrigues Damascena, Kennedy; de Almeida Maciel Neto, José

2017-07-01

One of the main natural uranium deposits in Brazil is located in the municipality of Espinharas, in the State of Paraíba. This area may present high levels of natural radioactivity due to the presence of these radionuclides. Since this is a populated area, there is need for a radioecological dosimetry assessment to investigate the possible risks to the population. Based on this problem, the objective of this study was to estimate the environmental effective dose outdoors in inhabited areas influenced by the uranium deposit, using the specific activities of equivalent uranium, equivalent thorium and 40 K and conversion factors. The environmental assessment was carried using gamma spectroscopy in sixty-two points within the municipality, with a high-resolution gamma spectrometer with HPGe semiconductor detector and Be window. The results obtained ranged from 0.01 to 19.11 mSv y -1 , with an average of 2.64 mSv y -1 . These levels are, on average, 23 times higher than UNSCEAR reference levels and up to 273 times the reference value of the earth's crust for primordial radionuclides. Therefore, given the high radioactivity levels found, we conclude that there is need for further investigation to evaluate the levels of radioactivity in indoor environments, which will reflect more closely the risks of the local population. Copyright © 2017 Elsevier Inc. All rights reserved.

REMOVAL OF ALUMINUM COATINGS

DOEpatents

Peterson, J.H.

1959-08-25

A process is presented for dissolving aluminum jackets from uranium fuel elements without attack of the uranium in a boiling nitric acid-mercuric nitrate solution containing up to 50% by weight of nitrtc acid and mercuric nitrate in a concentration of between 0.05 and 1% by weight.

Efficacy of acetate-amended biostimulation for uranium sequestration: Combined analysis of sediment/groundwater geochemistry and bacterial community structure

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

Xu, Jie; Veeramani, Harish; Qafoku, Nikolla P.

Systematic flow-through column experiments were conducted using sediments and ground water collected from different subsurface localities at the U.S. Department of Energy’s Integrated Field Research Challenge site in Rifle, Colorado. The principal purpose of this study is to gain a better understanding of the interactive effects of groundwater geochemistry, sediment mineralogy, and indigenous bacterial community structures on the efficacy of uranium removal from the groundwater with/without acetate amendment. Overall, we find that the subtle variations in the sediments’ mineralogy, particle size, redox conditions, as well as contents of metal(loid) co-contaminants showed a pronounced effect on the associated bacterial population andmore » composition, which mainly determines the system’s performance with respect to uranium removal. Positive relationship was identified between the abundance of dissimilatory sulfate-reduction genes (i.e., drsA), markers of sulfate-reducing bacteria, and the sediments’ propensity to sequester aqueous uranium. In contrast, no obvious connections were observed between the abundance of common iron-reducing bacteria, e.g., Geobacter spp., and the sediments’ ability to sequester uranium. In the sediments with low bacterial biomass and the absence of sulfate-reducing conditions, abiotic adsorption onto mineral surfaces such as phyllosilicates likely played a relatively major role in the attenuation of aqueous uranium; however, in these scenarios, acetate amendment induced detectable rebounds in the effluent uranium concentrations. The results of this study suggest that reductive immobilization of uranium can be achieved under predominantly sulfate-reducing conditions, and provide insight into the integrated roles of various biogeochemical components in long-term uranium sequestration.« less

Nuclear fuel electrorefiner

DOEpatents

Ahluwalia, Rajesh K.; Hua, Thanh Q.

2004-02-10

The present invention relates to a nuclear fuel electrorefiner having a vessel containing a molten electrolyte pool floating on top of a cadmium pool. An anodic fuel dissolution basket and a high-efficiency cathode are suspended in the molten electrolyte pool. A shroud surrounds the fuel dissolution basket and the shroud is positioned so as to separate the electrolyte pool into an isolated electrolyte pool within the shroud and a bulk electrolyte pool outside the shroud. In operation, unwanted noble-metal fission products migrate downward into the cadmium pool and form precipitates where they are removed by a filter and separator assembly. Uranium values are transported by the cadmium pool from the isolated electrolyte pool to the bulk electrolyte pool, and then pass to the high-efficiency cathode where they are electrolytically deposited thereto.

Vanadium-uranium extraction from Wyoming vanadiferoud silicates. Report of investigations/1983

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

Hayashi, M.; Nichols, I.L.; Huiatt, J.L.

1983-11-01

The Bureau of Mines conducted laboratory studies on low-grade vanadiferous silicates from the Pumpkin Buttes and Nine Mile Lake deposits of Wyoming to examine techniques for extracting vanadium and uranium. Recovery from low-grade sources such as these could contribute to future vanadium production and reduce reliance on vanadium imports.

Elevated Uranium in Aquifers of the Jacobsville Sandstone

NASA Astrophysics Data System (ADS)

Sherman, H.; Gierke, J.

2003-12-01

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

In-line assay monitor for uranium hexafluoride

DOEpatents

Wallace, S.A.

1980-03-21

An in-line assay monitor for determining the content of uranium-235 in a uranium hexafluoride gas isotopic separation system is provided which removes the necessity of complete access to the operating parameters of the system for determining the uranium-235 content. The method and monitor for carrying out the method involve cooling of a radiation pervious chamber connected in fluid communication with the selected point in the system to withdraw a specimen and solidify the specimen in the chamber. The specimen is irradiated by means of an ionizing radiation source of energy different from that of the 185 keV gamma emissions from uranium-235. The uranium-235 content of the specimen is determined from comparison of the accumulated 185 keV energy counts and reference energy counts. The latter is used to measure the total uranium isotopic content of the specimen.

Effect of uranium(VI) speciation on simultaneous microbial reduction of uranium(VI) and iron(III).

PubMed

Stewart, Brandy D; Amos, Richard T; Fendorf, Scott

2011-01-01

Uranium is a pollutant of concern to both human and ecosystem health. Uranium's redox state often dictates whether it will reside in the aqueous or solid phase and thus plays an integral role in the mobility of uranium within the environment. In anaerobic environments, the more oxidized and mobile form of uranium (UO2(2+) and associated species) may be reduced, directly or indirectly, by microorganisms to U(IV) with subsequent precipitation of UO. However, various factors within soils and sediments, such as U(VI) speciation and the presence of competitive electron acceptors, may limit biological reduction of U(VI). Here we examine simultaneous dissimilatory reduction of Fe(III) and U(VI) in batch systems containing dissolved uranyl acetate and ferrihydrite-coated sand. Varying amounts of calcium were added to induce changes in aqueous U(VI) speciation. The amount of uranium removed from solution during 100 h of incubation with S. putrefaciens was 77% in absence of Ca or ferrihydrite, but only 24% (with ferrihydrite) and 14% (without ferrihydrite) were removed for systems with 0.8 mM Ca. Dissimilatory reduction of Fe(III) and U(VI) proceed through different enzyme pathways within one type of organism. We quantified the rate coefficients for simultaneous dissimilatory reduction of Fe(III) and U(VI) in systems varying in Ca concecentration (0-0.8 mM). The mathematical construct, implemented with the reactive transport code MIN3P, reveals predominant factors controlling rates and extent of uranium reduction in complex geochemical systems.

Uranium reduction and microbial community development in response to stimulation with different electron donors.

PubMed

Barlett, Melissa; Moon, Hee Sun; Peacock, Aaron A; Hedrick, David B; Williams, Kenneth H; Long, Philip E; Lovley, Derek; Jaffe, Peter R

2012-07-01

Stimulating microbial reduction of soluble U(VI) to less soluble U(IV) shows promise as an in situ bioremediation strategy for uranium contaminated groundwater, but the optimal electron donors for promoting this process have yet to be identified. The purpose of this study was to better understand how the addition of various electron donors to uranium-contaminated subsurface sediments affected U(VI) reduction and the composition of the microbial community. The simple electron donors, acetate or lactate, or the more complex donors, hydrogen-release compound (HRC) or vegetable oil, were added to the sediments incubated in flow-through columns. The composition of the microbial communities was evaluated with quantitative PCR probing specific 16S rRNA genes and functional genes, phospholipid fatty acid analysis, and clone libraries. All the electron donors promoted U(VI) removal, even though the composition of the microbial communities was different with each donor. In general, the overall biomass, rather than the specific bacterial species, was the factor most related to U(VI) removal. Vegetable oil and HRC were more effective in stimulating U(VI) removal than acetate. These results suggest that the addition of more complex organic electron donors could be an excellent option for in situ bioremediation of uranium-contaminated groundwater.

DISSOLUTION METHOD OF REMOVING BONDING AGENTS

DOEpatents

Hyman, H.H.

1960-04-19

A method is given for removing residual aluminumsilicon bonding agents from uranium slugs after the removal of aluminum coatings. To accomplish this the slug is immersed in an aqueous solution about 0.75 N in hydrofluoric acid and about 7 N in nitric acid.

PROCESS OF ELECTROPLATING METALS WITH ALUMINUM

DOEpatents

Schickner, W.C.

1960-04-26

A process of electroplating aluminum on metals from a nonaqueous bath and a novel method of pretreating or conditioning the metal prior to electrodeposition of the aluminum are given. The process of this invention, as applied by way of example to the plating of uranium, comprises the steps of plating the uranium with the barrier inetal, immersing the barrier-coated uranium in fatty acid, and electrolyzing a water-free diethyl ether solution of aluminum chloride and lithium hydride while making the uranium the cathode until an aluminum deposit of the desired thickness has been formed. According to another preferred embodiment the barrier-coated uranium is immersed in an isopropyl alcohol solution of sterato chromic chloride prior to the fatty acid treatment of this invention.

Sustained removal of uranium from contaminated groundwater following stimulation of dissimilatory metal reduction.

PubMed

N'Guessan, A Lucie; Vrionis, Helen A; Resch, Charles T; Long, Philip E; Lovley, Derek R

2008-04-15

Previous field studies on in situ bioremediation of uranium-contaminated groundwater in an aquifer in Rifle, Colorado identified two distinct phases following the addition of acetate to stimulate microbial respiration. In phase I, Geobacter species are the predominant organisms, Fe(III) is reduced, and microbial reduction of soluble U(VI) to insoluble U(IV) removes uranium from the groundwater. In phase II, Fe(III) is depleted, sulfate is reduced, and sulfate-reducing bacteria predominate. Long-term monitoring revealed an unexpected third phase during which U(VI) removal continues even after acetate additions are stopped. All three of these phases were successfully reproduced in flow-through sediment columns. When sediments from the third phase were heat sterilized, the capacity for U(VI) removal was lost. In the live sediments U(VI) removed from the groundwater was recovered as U(VI) in the sediments. This contrasts to the recovery of U(IV) in sediments resulting from the reduction of U(VI) to U(IV) during the Fe(III) reduction phase in acetate-amended sediments. Analysis of 16S rRNA gene sequences in the sediments in which U(VI) was being adsorbed indicated that members of the Firmicutes were the predominant organisms whereas no Firmicutes sequences were detected in background sediments which did not have the capacity to sorb U(VI), suggesting that the U(VI) adsorption might be due to the presence of these living organisms or at least their intact cell components. This unexpected enhanced adsorption of U(VI) onto sediments following the stimulation of microbial growth in the subsurface may potentially enhance the cost effectiveness of in situ uranium bioremediation.

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

NASA Astrophysics Data System (ADS)

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

1997-04-01

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

URANIUM PURIFICATION PROCESS

DOEpatents

Ruhoff, J.R.; Winters, C.E.

1957-11-12

A process is described for the purification of uranyl nitrate by an extraction process. A solution is formed consisting of uranyl nitrate, together with the associated impurities arising from the HNO/sub 3/ leaching of the ore, in an organic solvent such as ether. If this were back extracted with water to remove the impurities, large quantities of uranyl nitrate will also be extracted and lost. To prevent this, the impure organic solution is extracted with small amounts of saturated aqueous solutions of uranyl nitrate thereby effectively accomplishing the removal of impurities while not allowing any further extraction of the uranyl nitrate from the organic solvent. After the impurities have been removed, the uranium values are extracted with large quantities of water.

METHOD OF SEPARATING FISSION PRODUCTS FROM FUSED BISMUTH-CONTAINING URANIUM

DOEpatents

Wiswall, R.H.

1958-06-24

A process is described for removing metal selectively from liquid metal compositions. The method effects separation of flssion product metals selectively from dilute solution in fused bismuth, which contains uraniunn in solution without removal of more than 1% of the uranium. The process comprises contacting the fused bismuth with a fused salt composition consisting of sodium, potassium and lithium chlorides, adding to fused bismuth and molten salt a quantity of bismuth chloride which is stoichiometrically required to convert the flssion product metals to be removed to their chlorides which are more stable in the fused salt than in the molten metal and are, therefore, preferentially taken up in the fused salt phase.

Preliminary report on uranium deposits in the Miller Hill area, Carbon County, Wyoming

USGS Publications Warehouse

Love, J.D.

1953-01-01

A sequence of radioactive rocks of Miocene (?) age, the Browns Park formation, in the Miller Hill area of southern Wyoming is more than 1,000 feet thick. The formation crops out in an area of approximately 600 square miles, and consists of a basal conglomerate, tuffs, tuffaceous limy sandstones, and thin persistent radioactive algal limestones. Uranium is concentrated in both algal limestones and in tuffaceous limy sandstones. The uranium is believed to have been deposited. at least in part with the sediments, rather than to have come in at a later date. The highest uranium values were found in a widespread algal limestone bed, which contains as much as 0. 15 percent uranium. Values of 0.01 percent uranium or more were obtained from 8 samples taken from approximately 220 feet of stratigraphic section in the Browns Park formation. This is the first reported occurrence of limestone source rock from Wyoming that has been found to contain a commercial grade of uranium. The economic possibilities of the area have not been determined adequately and no estimates of tonnage are warranted at the present time. An airborne radiometric survey was made by the Geophysics Branch of the Geological Survey, of the west half of the area, recommended by the writer for investigation. Ground check of all anomalies reported at that time showed that they were in localities where the background radiation was much higher than average. Additional localities with high background radiation were found on the ground in the area east of that which was flown.

Geological and geochemical aspects of uranium deposits. A selected, annotated bibliography. Vol. 1

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

White, M.B.; Garland, P.A.

1977-10-01

This bibliography was compiled by selecting 580 references from the Bibliographic Information Data Base of the Department of Energy's (DOE) National Uranium Resource Evaluation (NURE) Program. This data base and five others have been created by the Ecological Sciences Information Center to provide technical computer-retrievable data on various aspects of the nation's uranium resources. All fields of uranium geology are within the defined scope of the project, as are aerial surveying procedures, uranium reserves and resources, and universally applied uranium research. References used by DOE-NURE contractors in completing their aerial reconnaissance survey reports have been included at the request ofmore » the Grand Junction Office, DOE. The following indexes are provided to aid the user in locating reference of interest: author, keyword, geographic location, quadrangle name, geoformational index, and taxonomic name.« less

Australia unlocks her uranium reserves. [Will develop deposits in Northern Territories

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

Scott, W.E.

1977-11-01

The economic implications of Australia's move to permit the development of uranium mining and to resume exporting uranium have led to forecasts that range from pessimism over unseen factors to an optimistic estimate of $A20 billion and 500,000 jobs. Direct benefits will go to those involved in road construction, mining equipment, and construction camps. The goverment plan calls for mining operations and yellowcake exports from four major uranium mines by 1985. An overview is given of the development plan, which emphasizes an orderly procedure rather than exploitation and excessive competition. The uranium industry is viewed as a stable long-term suppliermore » for international trade. Customers will be required to submit to international Atomic Energy Agency inspection and must guarantee to limit their uranium use to peaceful projects. (DCK)« less

PROCESSES OF RECOVERING URANIUM FROM A CALUTRON

DOEpatents

Baird, D.O.; Zumwalt, L.R.

1958-07-15

An improved process is described for recovering the residue of a uranium compound which has been subjected to treatment in a calutron, from the parts of the calutron disposed in the source region upon which the residue is deposited. The process may be utilized when the uranium compound adheres to a surface containing metals of the group consisting of copper, iron, chromium, and nickel. The steps comprise washing the surface with an aqueous acidic oxidizing solvent for the uranium whereby there is obtained an acidic aqueous Solution containing uranium as uranyl ions and metals of said group as impurities, treating the acidic solution with sodium acetate in the presenee of added sodium nitrate to precipitate the uranium as sodium uranyl acetate away from the impurities in the solution, and separating the sodium uranyl acetate from the solution.

THE CHEMICAL ANALYSIS OF TERNARY ALLOYS OF PLUTONIUM WITH MOLYBDENUM AND URANIUM

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

Phillips, G.; Woodhead, J.; Jenkins, E.N.

1958-09-01

It is shown that the absorptiometric determination of molybdenum as thiocyanate may be used in the presence of plutonium. Molybdenum interferes with previously published methods for determining uranium and plutonium but conditlons have been established for its complete removal by solvent extraction of the compound with alpha -benzoin oxime. The previous methods for uranium and plutonium are satisfactory when applied to the residual aqueous phase following this solvent extraction. (auth)

Small-scale geochemical cycles and the distribution of uranium in central and north Florida organic deposits

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

Bond, P.A.

1993-03-01

The global geochemical cycle for an element tracks its path from its various sources to its sinks via processes of weathering and transportation. The cycle may then be quantified in a necessarily approximate manner. The geochemical cycle (thus quantified) reveals constraints (known and unknown) on an element's behavior imposed by the various processes which act on it. In the context of a global geochemical cycle, a continent becomes essentially a source term. If, however, an element's behavior is examined in a local or regional context, sources and their related sinks may be identified. This suggests that small-scale geochemical cycles maymore » be superimposed on global geochemical cycles. Definition of such sub-cycles may clarify the distribution of an element in the earth's near-surface environment. In Florida, phosphate minerals of the Hawthorn Group act as a widely distributed source of uranium. Uranium is transported by surface- and ground-waters. Florida is the site of extensive wetlands and peatlands. The organic matter associated with these deposits adsorbs uranium and may act as a local sink depending on its hydrogeologic setting. This work examines the role of organic matter in the distribution of uranium in the surface and shallow subsurface environments of central and north Florida.« less

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

DOE PAGES

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

2016-08-31

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

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

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

Balboni, Enrica; Jones, Nina; Spano, Tyler

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

Tc-99 Decontamination From Heat Treated Gaseous Diffusion Membrane -Phase I

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

Oji, L.; Wilmarth, B.; Restivo, M.

2017-03-13

Uranium gaseous diffusion cascades represent a significant environmental challenge to dismantle, containerize and dispose as low-level radioactive waste. Baseline technologies rely on manual manipulations involving direct access to technetium-contaminated piping and materials. There is a potential to utilize novel thermal decontamination technologies to remove the technetium and allow for on-site disposal of the very large uranium converters. Technetium entered these gaseous diffusion cascades as a hexafluoride complex in the same fashion as uranium. Technetium, as the isotope Tc-99, is an impurity that follows uranium in the first cycle of the Plutonium and Uranium Extraction (PUREX) process. The technetium speciation ormore » exact form in the gas diffusion cascades is not well defined. Several forms of Tc-99 compounds, mostly the fluorinated technetium compounds with varying degrees of volatility have been speculated by the scientific community to be present in these cascades. Therefore, there may be a possibility of using thermal desorption, which is independent of the technetium oxidation states, to perform an in situ removal of the technetium as a volatile species and trap the radionuclide on sorbent traps which could be disposed as low-level waste.« less

Rapid extraction and assay of uranium from environmental surface samples

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

Barrett, Christopher A.; Chouyyok, Wilaiwan; Speakman, Robert J.

Extraction methods enabling faster removal and concentration of uranium compounds for improved trace and low-level assay are demonstrated for standard surface sampling material in support of nuclear safeguards efforts, health monitoring, and other nuclear analysis applications. A key problem with the existing surface sampling swipes is the requirement for complete digestion of sample and sampling matrix. This is a time-consuming and labour-intensive process that limits laboratory throughput, elevates costs, and increases background levels. Various extraction methods are explored for their potential to quickly and efficiently remove different chemical forms of uranium from standard surface sampling material. A combination of carbonatemore » and peroxide solutions is shown to give the most rapid and complete form of uranyl compound extraction and dissolution. This rapid extraction process is demonstrated to be compatible with standard inductive coupled plasma mass spectrometry methods for uranium isotopic assay as well as screening techniques such as x-ray fluorescence. The general approach described has application beyond uranium to other analytes of nuclear forensic interest (e.g., rare earth elements and plutonium) as well as heavy metals for environmental and industrial hygiene monitoring.« less

Improved ion exchange membrane

NASA Technical Reports Server (NTRS)

Rembaum, A.; Yen, S. P. S.; Klein, E.

1975-01-01

Membrane, made from commercially-available hollow fibers, is used in reverse osmosis, or dialysis. Fiber has skin layers which pass only small molecules. Macromolecules cannot penetrate skin. Fibers can also be used to remove other undesirable anions, such as phosphate, sulfate, carbonate, and uranium in form of uranium-sulfate complex.

The Feasibility of Ending HEU Fuel Use in the U.S. Navy

DOE PAGES

Philippe, Sebastian; von Hippel, Frank

2016-11-01

We report that since September 11, 2001, the U.S. government has sought to remove weapons-useable highly enriched uranium (HEU) containing 20 percent or more uranium-235 from as many locations as possible because of concerns about the possibility of nuclear terrorism.

Incorporation of Uranium: II. Distribution of Uranium Absorbed through the Lungs and the Skin

PubMed Central

Walinder, G.; Fries, B.; Billaudelle, U.

1967-01-01

In experiments on mice, rabbits, and piglets the distribution of uranium was studied at different times after exposure. Uranium was administered by inhalation (mice) and through the skin (rabbits and piglets). These investigations show that the uptakes of uranium in different organs of the three species are highly dependent on the amounts administered. There seems to be a saturation effect in the spleen and bone tissue whenever the uranium concentration in the blood exceeds a certain level. The effect in the kidney is completely different. If, in a series of animals, the quantity of uranium is continuously increased, the uptakes by the kidneys increase more rapidly than the quantities administered. This observation seems to be consistent with the toxic effects of uranium on the capillary system in the renal cortex. Polyphloretin phosphate, a compound which reduces permeability, was investigated with respect to its effect on the uptake of uranium deposited in skin wounds in rabbits and piglets. It significantly reduced the absorption of uranium, even from depots in deep wounds. The findings are discussed with reference to the routine screening of persons exposed to uranium at AB Atomenergi. Images PMID:6073090

An evaluation of uranium-series dating of fossil echinoids from southern California Pleistocene marine terraces

USGS Publications Warehouse

Muhs, D.R.; Kennedy, G.L.

1985-01-01

Fossil sea urchins (Strongylocentrotus) from Pleistocene marine terraces on the southern California Channel Islands have been dated by the uranium-series method in order to test the suitability of echinoids for dating marine terraces. Results indicate that urchin plates and spines do not behave as closed systems with respect to both uranium and thorium. Calculated ages based on these data do not agree with uranium-series ages (120,000 and 127,000 yrs) obtained previously from corals from the same localities. Thus, fossil sea urchins (Strongylocentrotus) are not considered suitable for uraniumseries dating of Pleistocene marine terrace deposits. ?? 1985.

The synthesis, characterization and application of iron oxide nanocrystals in magnetic separations for arsenic and uranium removal

NASA Astrophysics Data System (ADS)

Mayo, John Thomas

Arsenic and uranium in the environment are hazardous to human health and require better methods for detection and remediation. Nanocrystalline iron oxides offer a number of advantages as sorbents for water purification and environmental remediation. First, highly uniform and crystalline iron oxide nanocrystals (nMAG) were prepared using thermal decomposition of iron salts in organic solutions; for the applications of interest in this thesis, a central challenge was the adaptation of these conventional synthetic methods to the needs of low infrastructure and economically disadvantaged settings. We show here that it is possible to form highly uniform and magnetically responsive nanomaterials using starting reagents and equipment that are readily available and economical. The products of this approach, termed the 'Kitchen Synthesis', are of comparable quality and effectiveness to laboratory materials. The narrow size distributions of the iron oxides produced in the laboratory synthesis made it possible to study the size-dependence of the magnetic separation efficiency of nanocrystals; generally as the diameter of particles increased they could be removed under lower applied magnetic fields. In this work we take advantage of this size-dependence to use magnetic separation as a tool to separate broadly distributed populations of magnetic materials. Such work makes it possible to use these materials in multiplexed separation and sensing schemes. With the synthesis and magnetic separation studies of these materials completed, it was possible to optimize their applications in water purification and environmental remediation. These materials removed both uranium and arsenic from contaminated samples, and had remarkably high sorption capacities --- up to 12 wt% for arsenic and 30 wt% for uranium. The contaminated nMAG is removed from the drinking water by either retention in a sand column, filter, or by magnetic separation. The uranium adsorption process was also utilized for the enhanced detection of uranium in environmental matrices. By relying on alpha-particle detection in well-formed and dense nMAG films, it was possible to improve soil detection of uranium by more than ten-thousand-fold. Central for this work was a detailed understanding of the chemistry at the iron oxide interface, and the role of the organic coatings in mediating the sorption process.

PROCESSES OF RECLAIMING URANIUM FROM SOLUTIONS

DOEpatents

Zumwalt, L.R.

1959-02-10

A process is described for reclaiming residual enriched uranium from calutron wash solutions containing Fe, Cr, Cu, Ni, and Mn as impurities. The solution is adjusted to a pH of between 2 and 4 and is contacted with a metallic reducing agent, such as iron or zinc, in order to reduce the copper to metal and thereby remove it from the solution. At the same time the uranium present is reduced to the uranous state The solution is then contacted with a precipitate of zinc hydroxide or barium carbonate in order to precipitate and carry uranium, iron, and chromium away from the nickel and manganese ions in the solution. The uranium is then recovered fronm this precipitate.

Uranium deposits at Shinarump Mesa and some adjacent areas in the Temple Mountain district, Emery County, Utah

USGS Publications Warehouse

Wyant, Donald G.

1953-01-01

Deposits of uraniferous hydrocarbons are associated with carnotite in the Shinarump conglomerate of Triassic age at Shinarump Mesa and adjacent areas of the Temple Mountain district in the San Rafael Swell of Emery County, Utah. The irregular ore bodies of carnotite-bearing sandstone are genetically related to lenticular uraniferous ore bodies containing disseminated asphaltitic and humic hydrocarbon in permeable sandstones and were localized indirectly by sedimentary controls. Nearly non-uraniferous bitumen commonly permeates the sandstones in the Shinarump conglomerate and the underlying Moekopi formation in the area. The ore deposits at Temple Mountain have been altered locally by hydrothermal solutions, and in other deposits throughout the area carnotite has been transported by ground and surface water. Uraniferous asphaltite is thought to be the non-volatile residue of an original weakly uraniferous crude oil that migrated into the San Rafael anticline; the ore metals concentrated in the asphaltite as the oil was devolatilized and polymerized. Carnotite is thought to have formed from the asphaltite by ground water leaching. It is concluded that additional study of the genesis of the asphaltitic uranium ores in the San Rafael Swell, of the processes by which the hydrocarbons interact and are modified (such as heat, polymerization, and hydrogenation under the influence of alpha-ray bombardment), of petroleum source beds, and of volcanic intrusive rocks of Tertiary age are of fundamental importance in the continuing study of the uranium deposits on the Colorado Plateau.

Field, model, and computer simulation study of some aspects of the origin and distribution of Colorado Plateau-type uranium deposits

USGS Publications Warehouse

Ethridge, F.G.; Sunada, D.K.; Tyler, Noel; Andrews, Sarah

1982-01-01

Numerous hypotheses have been proposed to account for the nature and distribution of tabular uranium and vanadium-uranium deposits of the Colorado Plateau. In one of these hypotheses it is suggested that the deposits resulted from geochemical reactions at the interface between a relatively stagnant groundwater solution and a dynamic, ore-carrying groundwater solution which permeated the host sandstones (Shawe, 1956; Granger, et al., 1961; Granger, 1968, 1976; and Granger and Warren, 1979). The study described here was designed to investigate some aspects of this hypothesis, particularly the nature of fluid flow in sands and sandstones, the nature and distribution of deposits, and the relations between the deposits and the host sandstones. The investigation, which was divided into three phases, involved physical model, field, and computer simulation studies. During the initial phase of the investigation, physical model studies were conducted in porous-media flumes. These studies verified the fact that humic acid precipitates could form at the interface between a humic acid solution and a potassium aluminum sulfate solution and that the nature and distribution of these precipitates were related to flow phenomena and to the nature and distribution of the host porous-media. During the second phase of the investigation field studies of permeability and porosity patterns in Holocene stream deposits were investigated and the data obtained were used to design more realistic porous media models. These model studies, which simulated actual stream deposits, demonstrated that precipitates possess many characteristics, in terms of their nature and relation to host sandstones, that are similar to ore deposits of the Colorado Plateau. The final phase of the investigation involved field studies of actual deposits, additional model studies in a large indoor flume, and computer simulation studies. The field investigations provided an up-to-date interpretation of the depositional environments of the host sandstones in the Slick Rock District and data on the nature and distribution of the ore deposits which are found to be directly related to the architecture of the host sandstones which acted as conduits for the transport of mineralized groundwaters. Large-scale model studies, designed to simulate Grants Mineral Belt deposits, demonstrated that precipitates had characteristics similar to those of actual uranium deposits and data obtained from these studies strongly supported the hypothesis that the ores formed soon after deposition of the host sandstones and that their distribution was largely controlled by permeability and porosity patterns established at the time of deposition of the host sandstones. A numerical model was developed during the second and third stages of the investigation that can predict favorable locations for mineralization given sufficient data on porosity, hydraulic conductivity, the distribution and thickness of sandstone hosts, and an estimate of the initial hydrologic conditions. The model was successfully tested using data from the Slick Rock District.

METHOD OF ELECTROPLATING ON URANIUM

DOEpatents

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

1959-04-28

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

Reconnaissance for uranium in black shale, Northern Rocky Mountains and Great Plains, 1953

USGS Publications Warehouse

Mapel, W.J.

1954-01-01

Reconnaissance examinations for uranium in 22 formations containing black shale were conducted in parts of Montana, North Dakota, Utah, Idaho, and Oregon during 1953. About 150 samples from 80 outcrop localities and 5 oil and gas wells were submitted for uranium determinations. Most of the black shale deposits examined contain less than 0.003 percent uranium; however, thin beds of black shale at the base of the Mississippian system contain 0.005 percent uranium at 2 outcrop localities in southwestern Montana and as much as 0.007 percent uranium in a well in northeastern Montana. An eight-foot bed of phosphatic black shale at the base of the Brazer limestone of Late Mississippian age in Rich County, Utah, contains as much as 0.009 percent uranium. Commercial gamma ray logs of oil and gas wells drilled in Montana and adjacent parts of the Dakotas indicate that locally the Heath shale of Late Mississippian age contains as much as 0.01 percent equivalent uranium, and black shales of Late Cretaceous age contain as much as 0.008 percent equivalent uranium.

Uranium isotopes fingerprint biotic reduction.

PubMed

Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; Monga, Nikhil; Romaniello, Stephen J; Weyer, Stefan; Bernier-Latmani, Rizlan

2015-05-05

Knowledge of paleo-redox conditions in the Earth's history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U), i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth's crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. Additionally, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium.

Preliminary report on the Comet area, Jefferson County, Montana

USGS Publications Warehouse

Becraft, George Earle

1953-01-01

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

A preliminary evaluation of the nonfuel mineral potential of Somalia

USGS Publications Warehouse

Greenwood, W.R.

1982-01-01

Additional exploration in Somalia is warranted for a wide variety of metallic and nonmetallic deposits. In Precambrian rocks, deposit types favorable for exploration include: a banded iron formation; platinum-bearing mafic-ultramafic complexes; tin-bearing quartz veins; phosphorite; stratabound base-metal deposits; uranium associated with Precambrian(?) syenite; apatite, molybdenum, and alumina in alkalic rocks; Jurassic and Cretaceous black shales; possible bedded-barite and massive base- and precious-metal sulfide deposits; vein barite in Tertiary rocks in fault zones; sepiolite and bentonite for drilling muds and other industrial uses; celestite; possible Tertiary zeolite; and uranium deposits. Several of these deposit types could be Jointly developed and integrated into domestic industries; for example, phosphate and gypsum, or bentonite for pelletized iron from the banded iron deposits. Other deposits such as barite and sepiolite are of value because of their proximity to major drilling operations in the Arabian Gulf. Still other deposits, such as alumina and banded iron, might be marketable because of proximity to aluminum and iron-refining industries now being constructed in Saudi Arabia. Some deposits, such as celestite, can be developed with little capital investment; others, such as the iron deposits, would require large capital commitments. Exploration and evaluation for many of these deposits can be accomplished by Somali geologists with a few advisors. Most of the deposits require feasibility studies conducted by teams of economic geologists, extractive metallurgists, and economists. Some marginal deposits could be exploited if cooperative development schemes could be negotiated with governments in nearby countries.

Remediation of uranium contaminated soils with bicarbonate extraction and microbial U(VI) reduction

USGS Publications Warehouse

Philips , Elizabeth J.P.; Landa, Edward R.; Lovely, Derek R.

1995-01-01

A process for concentrating uranium from contaminated soils in which the uranium is first extracted with bicarbonate and then the extracted uranium is precipitated with U(VI)-reducing microorganisms was evaluated for a variety of uranuum-contaminated soils. Bicarbonate (100 mM) extracted 20–94% of the uranium that was extracted with nitric acid. The U(VI)-reducing microorganism,Desulfovibrio desulfuricans reduced the U(VI) to U(IV) in the bicarbonate extracts. In some instances unidentified dissolved extracted components, presumably organics, gave the extract a yellow color and inhibited U(VI) reduction and/or the precipitation of U(IV). Removal of the dissolved yellow material with the addition of hydrogen peroxide alleviated this inhibition. These results demonstrate that bicarbonate extraction of uranium from soil followed by microbial U(VI) reduction might be an effective mechanism for concentrating uranium from some contaminated soils.

77 FR 33782 - License Amendment To Construct and Operate New In Situ Leach Uranium Recovery Facility; Uranium...

Federal Register 2010, 2011, 2012, 2013, 2014

2012-06-07

...-Filing system also distributes an email notice that provides access to the document to the NRC's Office... mail, or expedited delivery service to the Office of the Secretary, Sixteenth Floor, One White Flint... courier, express mail, or expedited delivery service upon depositing the document with the provider of the...

METHOD OF FORMING A FUEL ELEMENT FOR A NUCLEAR REACTOR

DOEpatents

Layer, E.H. Jr.; Peet, C.S.

1962-01-23

A method is given for preparing a fuel element for a nuclear reactor. The method includes the steps of sandblasting a body of uranium dioxide to roughen the surface thereof, depositing a thin layer of carbon thereon by thermal decomposition of methane, and cladding the uranium dioxide body with zirconium by gas pressure bonding. (AEC)

Surface Cleaning Techniques: Ultra-Trace ICP-MS Sample Preparation and Assay of HDPE

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

Overman, Nicole R.; Hoppe, Eric W.; Addleman, Raymond S.

2013-06-01

The world’s most sensitive radiation detection and assay systems depend upon ultra-low background (ULB) materials to reduce unwanted radiological backgrounds. Herein, we evaluate methods to clean HDPE, a material of interest to ULB systems and the means to provide rapid assay of surface and bulk contamination. ULB level material and ultra-trace level detection of actinide elements is difficult to attain, due to the introduction of contamination from sample preparation equipment such as pipette tips, sample vials, forceps, etc. and airborne particulate. To date, literature available on the cleaning of such polymeric materials and equipment for ULB applications and ultra-trace analysesmore » is limited. For these reasons, a study has been performed to identify an effective way to remove surface contamination from polymers in an effort to provide improved instrumental detection limits. Inductively Coupled Plasma Mass Spectroscopy (ICP-MS) was utilized to assess the effectiveness of a variety of leachate solutions for removal of inorganic uranium and thorium surface contamination from polymers, specifically high density polyethylene (HDPE). HDPE leaching procedures were tested to optimize contaminant removal of thorium and uranium. Calibration curves for thorium and uranium ranged from 15 ppq (fg/mL) to 1 ppt (pg/mL). Detection limits were calculated at 6 ppq for uranium and 7 ppq for thorium. Results showed the most effective leaching reagent to be clean 6 M nitric acid for 72 hour exposures. Contamination levels for uranium and thorium found in the leachate solutions were significant for ultralow level radiation detection applications.« less

X-ray Analysis of Defects and Anomalies in AGR-5/6/7 TRISO Particles

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

Helmreich, Grant W.; Hunn, John D.; Skitt, Darren J.

2017-06-01

Coated particle fuel batches J52O-16-93164, 93165, 93166, 93168, 93169, 93170, and 93172 were produced by Babcock and Wilcox Technologies (BWXT) for possible selection as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR), or may be used for other tests. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT lot J52R-16-69317 containing a mixture of 15.4%-enriched uranium carbide and uranium oxide (UCO), with the exception of Batchmore » 93164, which used similar kernels from BWXT lot J52L-16-69316. The TRISO-coatings consisted of a ~50% dense carbon buffer layer with 100-μmnominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μm-nominal thickness. Each coated particle batch was sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batch was designated by appending the letter A to the end of the batch number (e.g., 93164A). Secondary upgrading by sieving was performed on the upgraded batches to remove specific anomalies identified during analysis for Defective IPyC, and the upgraded batches were designated by appending the letter B to the end of the batch number (e.g., 93165B). Following this secondary upgrading, coated particle composite J52R-16-98005 was produced by BWXT as fuel for the AGR Program’s AGR-5/6/7 irradiation test in the INL ATR. This composite was comprised of coated particle fuel batches J52O-16-93165B, 93168B, 93169B, and 93170B.« less

Acceptance Test Data for the AGR-5/6/7 Irradiation Test Fuel Composite Defective IPyC Fraction and Pyrocarbon Anisotropy

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

Helmreich, Grant W.; Hunn, John D.; Skitt, Darren J.

Coated particle composite J52R-16-98005 was produced by Babcock and Wilcox Technologies (BWXT) as fuel for the Advanced Gas Reactor Fuel Development and Qualification (AGR) Program’s AGR-5/6/7 irradiation test in the Idaho National Laboratory (INL) Advanced Test Reactor (ATR). This composite was comprised of four coated particle fuel batches J52O-16-93165B (26%), 93168B (26%), 93169B (24%), and 93170B (24%), chosen based on the Quality Control (QC) data acquired for each individual candidate AGR-5/6/7 batch. Each batch was coated in a 150-mm-diameter production-scale fluidized-bed chemical vapor deposition (CVD) furnace. Tristructural isotropic (TRISO) coatings were deposited on 425-μm-nominal-diameter spherical kernels from BWXT Lot J52R-16-69317more » containing a mixture of 15.5%-enriched uranium carbide and uranium oxide (UCO). The TRISO coatings consisted of four consecutive CVD layers: a ~50% dense carbon buffer layer with 100-μm-nominal thickness, a dense inner pyrolytic carbon (IPyC) layer with 40-μm-nominal thickness, a silicon carbide (SiC) layer with 35-μm-nominal thickness, and a dense outer pyrolytic carbon (OPyC) layer with 40-μm-nominal thickness. The TRISO-coated particle batches were sieved to upgrade the particles by removing over-sized and under-sized material, and the upgraded batches were designated by appending the letter A to the end of the batch number (e.g., 93165A). Secondary upgrading by sieving was performed on the A-designated batches to remove particles with missing or very-thin buffer layers that were identified during previous analysis of the individual batches for defective IPyC, as reported in the acceptance test data report for the AGR-5/6/7 production batches [Hunn et al. 2017]. The additionally-upgraded batches were designated by appending the letter B to the end of the batch number (e.g., 93165B).« less

Thorium and Uranium in the Rock Raw Materials Used For the Production of Building Materials

NASA Astrophysics Data System (ADS)

Pękala, Agnieszka

2017-10-01

Thorium and uranium are constant components of all soils and most minerals thereby rock raw materials. They belong to the particularly dangerous elements because of their natural radioactivity. Evaluation of the content of the radioactive elements in the rock raw materials seems to be necessary in the early stage of the raw material evaluation. The rock formations operated from deposits often are accumulated in landfills and slag heaps where the concentration of the radioactive elements can be many times higher than under natural conditions. In addition, this phenomenon may refer to buildings where rock raw materials are often the main components of the construction materials. The global control system of construction products draws particular attention to the elimination of used construction products containing excessive quantities of the natural radioactive elements. In the presented study were determined the content of thorium and uranium in rock raw materials coming from the Bełachatów lignite deposit. The Bełchatów lignite deposit extracts mainly lignite and secondary numerous accompanying minerals with the raw material importance. In the course of the field works within the framework of the carried out work has been tested 92 samples of rocks of varied petrographic composition. There were carried out analyses of the content of the radioactive elements for 50 samples of limestone of the Jurassic age, 18 samples of kaolinite clays, and 24 samples of siliceous raw materials, represented by opoka-rocks, diatomites, gaizes and clastic rocks. The measurement of content of the natural radioactive elements thorium and uranium based on measuring the frequency counts of gamma quantum, recorded separately in measuring channels. At the same time performed measurements on volume patterns radioactive: thorium and uranium. The studies were carried out in Mazar spectrometer on the powdered material. Standardly performed ten measuring cycles, after which were calculated the concentration of radioactive elements in the sample. The highest concentration of thorium and uranium has been found in the clayey raw material. Their value was respectively from 8 to 12 mg/kg for thorium and from 2.3 to 3.5 mg/kg for uranium. In carbonate sediments the content of thorium was at the level from 0.5 to 2.1 mg/kg and uranium from 0.5-2.2 mg/kg. From a group of the siliceous raw materials the diatomite had a highest concentrations of radioactive elements where the content of thorium was from 1.5 to 1.8 mg/kg and uranium from 1.3 to 1.7 mg/kg.

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

USGS Publications Warehouse

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

2008-01-01

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

Uranium in the Surrounding of San Marcos-Sacramento River Environment (Chihuahua, Mexico)

PubMed Central

Rentería-Villalobos, Marusia; Cortés, Manuel Reyes; Mantero, Juan; Manjón, Guillermo; García-Tenorio, Rafael; Herrera, Eduardo; Montero-Cabrera, Maria Elena

2012-01-01

The main interest of this study is to assess whether uranium deposits located in the San Marcos outcrops (NW of Chihuahua City, Mexico) could be considered as a source of U-isotopes in its surrounding environment. Uranium activity concentrations were determined in biota, ground, and surface water by either alpha or liquid scintillation spectrometries. Major ions were analyzed by ICP-OES in surface water and its suspended matter. For determining uranium activity in biota, samples were divided in parts. The results have shown a possible lixiviation and infiltration of uranium from geological substrate into the ground and surface water, and consequently, a transfer to biota. Calculated annual effective doses by ingestion suggest that U-isotopes in biota could not negligibly contribute to the neighboring population dose. By all these considerations, it is concluded that in this zone there is natural enhancement of uranium in all environmental samples analyzed in the present work. PMID:22536148

Fuel Retention Improvement at High Temperatures in Tungsten-Uranium Dioxide Dispersion Fuel Elements by Plasma-Spray Cladding

NASA Technical Reports Server (NTRS)

Grisaffe, Salvatore J.; Caves, Robert M.

1964-01-01

An investigation was undertaken to determine the feasibility of depositing integrally bonded plasma-sprayed tungsten coatings onto 80-volume-percent tungsten - 20-volume-percent uranium dioxide composites. These composites were face clad with thin tungsten foil to inhibit uranium dioxide loss at elevated temperatures, but loss at the unclad edges was still significant. By preheating the composite substrates to approximately 3700 degrees F in a nitrogen environment, metallurgically bonded tungsten coatings could be obtained directly by plasma spraying. Furthermore, even though these coatings were thin and somewhat porous, they greatly inhibited the loss of uranium dioxide. For example, a specimen that was face clad but had no edge cladding lost 5.8 percent uranium dioxide after 2 hours at 4750 dgrees F in flowing hydrogen. A similar specimen with plasma-spray-coated edges, however, lost only 0.75 percent uranium dioxide under the same testing conditions.

Fractionation of 238U/235U by reduction during low temperature uranium mineralisation processes

NASA Astrophysics Data System (ADS)

Murphy, Melissa J.; Stirling, Claudine H.; Kaltenbach, Angela; Turner, Simon P.; Schaefer, Bruce F.

2014-02-01

Investigations of ‘stable’ uranium isotope fractionation during low temperature, redox transformations may provide new insights into the usefulness of the 238U/235U isotope system as a tracer of palaeoredox processes. Sandstone-hosted uranium deposits accumulate at an oxidation/reduction interface within an aquifer from the low temperature reduction of soluble U(VI) complexes in groundwaters, forming insoluble U(IV) minerals. This setting provides an ideal environment in which to investigate the effects of redox transformations on 238U/235U fractionation. Here we present the first coupled measurements of 238U/235U isotopic compositions and U concentrations for groundwaters and mineralised sediment samples from the same redox system in the vicinity of the high-grade Pepegoona sandstone-hosted uranium deposit, Australia. The mineralised sediment samples display extremely variable 238U/235U ratios (herein expressed as δUCRM145238, the per-mil deviation from the international NBL standard CRM145). The majority of mineralised sediment samples have δUCRM145238 values between -1.30±0.05 and 0.55±0.12‰, spanning a ca. 2‰ range. However, one sample has an unusually light isotopic composition of -4.13±0.05‰, which suggests a total range of U isotopic variability of up to ca. 5‰, the largest variation found thus far in a single natural redox system. The 238U/235U isotopic signature of the mineralised sediments becomes progressively heavier (enriched in 238U) along the groundwater flow path. The groundwaters show a greater than 2‰ variation in their 238U/235U ratios, ranging from δUCRM145238 values of -2.39±0.07 to -0.71±0.05‰. The majority of the groundwater data exhibit a clear systematic relationship between 238U/235U isotopic composition and U concentration; samples with the lowest U concentrations have the lowest 238U/235U ratios. The preferential incorporation of 238U during reduction of U(VI) to U(IV) and precipitation of uranium minerals leaves the groundwaters enriched in 235U, resulting in a progressive shift in 238U/235U towards lighter values in the aqueous phase as U is removed. These data can be modelled by a closed system Rayleigh fractionation model, with a fractionation factor (α, representing the 238U/235U composition of the groundwater relative to the solid uranium minerals) ranging from ∼0.9996 to 1.0000, with the majority of datapoints ranging from α values of 0.9998 to 0.9999. The sense and magnitude of the results of this study imply that 238U/235U fractionation is likely to be controlled by volume-dependent nuclear field shift effects during the reduction of U(VI) to U(IV) during mineralisation processes. These findings support the use of the 238U/235U isotopic system as a tracer to constrain the nature and timing of palaeoredox conditions.

A preliminary report on the rapid fluorimetric determination of uranium in low-grade ores

USGS Publications Warehouse

Grimaldi, F.S.; Levine, Harry

1950-01-01

A simple and very rapid fluorimetric procedure is described for the determination of uranium in low-grade shale and phosphate ores. The best working range is from 0.001 to about 0.04 percent U. The procedure employs batch extraction of uranium nitrate by ethyl acetate, using aluminum nitrate as the salting agent, prior to the visual fluorimetric estimation. The procedure is especially designed to save reagents; only 9.5 g of aluminum nitrate and 10 ml of ethyl acetate being used for one analysis. The solution of the sample by means of a fusion with NaOH-NaNO3 flux is rapid. After fusion the sample is immediately extracted without removing silica and other hydrolytic precipitates. Aluminum nitrate very effectively ties up fluoride and phosphate, thus eliminating steps required for their removal.

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

NASA Astrophysics Data System (ADS)

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

2017-02-01

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

Model-Based Analysis of the Role of Biological, Hydrological and Geochemical Factors Affecting Uranium Bioremediation

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

Zhao, Jiao; Scheibe, Timothy D.; Mahadevan, Radhakrishnan

2011-01-24

Uranium contamination is a serious concern at several sites motivating the development of novel treatment strategies such as the Geobacter-mediated reductive immobilization of uranium. However, this bioremediation strategy has not yet been optimized for the sustained uranium removal. While several reactive-transport models have been developed to represent Geobacter-mediated bioremediation of uranium, these models often lack the detailed quantitative description of the microbial process (e.g., biomass build-up in both groundwater and sediments, electron transport system, etc.) and the interaction between biogeochemical and hydrological process. In this study, a novel multi-scale model was developed by integrating our recent model on electron capacitancemore » of Geobacter (Zhao et al., 2010) with a comprehensive simulator of coupled fluid flow, hydrologic transport, heat transfer, and biogeochemical reactions. This mechanistic reactive-transport model accurately reproduces the experimental data for the bioremediation of uranium with acetate amendment. We subsequently performed global sensitivity analysis with the reactive-transport model in order to identify the main sources of prediction uncertainty caused by synergistic effects of biological, geochemical, and hydrological processes. The proposed approach successfully captured significant contributing factors across time and space, thereby improving the structure and parameterization of the comprehensive reactive-transport model. The global sensitivity analysis also provides a potentially useful tool to evaluate uranium bioremediation strategy. The simulations suggest that under difficult environments (e.g., highly contaminated with U(VI) at a high migration rate of solutes), the efficiency of uranium removal can be improved by adding Geobacter species to the contaminated site (bioaugmentation) in conjunction with the addition of electron donor (biostimulation). The simulations also highlight the interactive effect of initial cell concentration and flow rate on U(VI) reduction.« less

Assessment of background gamma radiation levels using airborne gamma ray spectrometer data over uranium deposits, Cuddapah Basin, India - A comparative study of dose rates estimated by AGRS and PGRS.

PubMed

Srinivas, D; Ramesh Babu, V; Patra, I; Tripathi, Shailesh; Ramayya, M S; Chaturvedi, A K

2017-02-01

The Atomic Minerals Directorate for Exploration and Research (AMD) has conducted high-resolution airborne gamma ray spectrometer (AGRS), magnetometer and time domain electromagnetic (TDEM) surveys for uranium exploration, along the northern margins of Cuddapah Basin. The survey area includes well known uranium deposits such as Lambapur-Peddagattu, Chitrial and Koppunuru. The AGRS data collected for uranium exploration is utilised for estimating the average absorbed rates in air due to radio-elemental (potassium in %, uranium and thorium in ppm) distribution over these known deposit areas. Further, portable gamma ray spectrometer (PGRS) was used to acquire data over two nearby locations one from Lambapur deposit, and the other from known anomalous zone and subsequently average gamma dose rates were estimated. Representative in-situ rock samples were also collected from these two areas and subjected to radio-elemental concentration analysis by gamma ray spectrometer (GRS) in the laboratory and then dose rates were estimated. Analyses of these three sets of results complement one another, thereby providing a comprehensive picture of the radiation environment over these deposits. The average absorbed area wise dose rate level is estimated to be 130 ± 47 nGy h -1 in Lambapur-Peddagattu, 186 ± 77 nGy h -1 in Chitrial and 63 ± 22 nGy h -1 in Koppunuru. The obtained average dose levels are found to be higher than the world average value of 54 nGy h -1 . The gamma absorbed dose rates in nGy h -1 were converted to annual effective dose rates in mSv y -1 as proposed by the United Nations Scientific Committee on the Effect of Atomic Radiation (UNSCEAR). The annual average effective dose rates for the entire surveyed area is 0.12 mSv y -1 , which is much lower than the recommended limit of 1 mSv y -1 by International Commission on Radiation protection (ICRP). It may be ascertained here that the present study establishes a reference data set (baseline) in these areas to assess any changes in gamma radiation levels due to mining and milling activities in future. Copyright © 2016 Elsevier Ltd. All rights reserved.

Chemical aspects of uranium behavior in soils: A review

NASA Astrophysics Data System (ADS)

Vodyanitskii, Yu. N.

2011-08-01

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

Dose-response relationships between internally-deposited uranium and select health outcomes in gaseous diffusion plant workers, 1948-2011.

PubMed

Yiin, James H; Anderson, Jeri L; Bertke, Stephen J; Tollerud, David J

2018-05-09

To examine dose-response relationships between internal uranium exposures and select outcomes among a cohort of uranium enrichment workers. Cox regression was conducted to examine associations between selected health outcomes and cumulative internal uranium with consideration for external ionizing radiation, work-related medical X-rays and contaminant radionuclides technetium ( 99 Tc) and plutonium ( 239 Pu) as potential confounders. Elevated and monotonically increasing mortality risks were observed for kidney cancer, chronic renal diseases, and multiple myeloma, and the association with internal uranium absorbed organ dose was statistically significant for multiple myeloma. Adjustment for potential confounders had minimal impact on the risk estimates. Kidney cancer, chronic renal disease, and multiple myeloma mortality risks were elevated with increasing internal uranium absorbed organ dose. The findings add to evidence of an association between internal exposure to uranium and cancer. Future investigation includes a study of cancer incidence in this cohort. © 2018 Wiley Periodicals, Inc.

National Uranium Resource Evaluation, Tularosa Quadrangle, New Mexico

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

Berry, V.P.; Nagy, P.A.; Spreng, W.C.

1981-12-01

Uranium favorability of the Tularosa Quadrangle, New Mexico, was evaluated to a depth of 1500 m using National Uranium Resource Evaluation criteria. Uranium occurrences reported in the literature were located, sampled, and described in detail. Areas of anomalous radioactivity, interpreted from an aerial radiometric survey, and geochemical anomalies, interpreted from hydrogeochemical and stream-sediment reconnaissance, were also investigated. Additionally, several hundred rock samples were studied in thin section, and supplemental geochemical analyses of rock and water samples were completed. Fluorometric analyses were completed for samples from the Black Range Primitive Area to augment previously available geochemical data. Subsurface favorability was evaluatedmore » using gamma-ray logs and descriptive logs of sample cuttings. One area of uranium favorability was delineated, based on the data made available from this study. This area is the Nogal Canyon cauldron margin zone. Within the zone, characterized by concentric and radial fractures, resurgent doming, ring-dike volcanism, and intracauldron sedimentation, uranium conentration is confined to magmatic-hydrothermal and volcanogenic uranium deposits.« less

Recovery of uranium from an irradiated solid target after removal of molybdenum-99 produced from the irradiated target

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

Reilly, Sean Douglas; May, Iain; Copping, Roy

A process for minimizing waste and maximizing utilization of uranium involves recovering uranium from an irradiated solid target after separating the medical isotope product, molybdenum-99, produced from the irradiated target. The process includes irradiating a solid target comprising uranium to produce fission products comprising molybdenum-99, and thereafter dissolving the target and conditioning the solution to prepare an aqueous nitric acid solution containing irradiated uranium. The acidic solution is then contacted with a solid sorbent whereby molybdenum-99 remains adsorbed to the sorbent for subsequent recovery. The uranium passes through the sorbent. The concentrations of acid and uranium are then adjusted tomore » concentrations suitable for crystallization of uranyl nitrate hydrates. After inducing the crystallization, the uranyl nitrate hydrates are separated from a supernatant. The process results in the purification of uranyl nitrate hydrates from fission products and other contaminants. The uranium is therefore available for reuse, storage, or disposal.« less

Geology of the Holocene surficial uranium deposit of the north fork of Flodelle Creek, northeastern Washington ( USA).

USGS Publications Warehouse

Johnson, S.Y.; Otton, J.K.; Macke, D.L.

1987-01-01

The N fork of Flodelle Creek drainage basin in NE Washington contains the first surficial U deposit to be mined in the US. The U was leached from granitic bedrock and fixed in organic-rich pond sediments. The distribution of these pond sediments and, therefore, the U has been strongly influenced by relict glacial topography, slope proceses, and beaver activity. Ponds in the drainage basin have been sinks for fine-grained, organic-rich sediments. These organic-rich sediments provide a suitable geochemical environment for precipitation and adsorption of uranium leached from granitic bedrock into ground, spring, and surface waters. Processes of pond formation have thus been important in the development of surficial U deposits in the N fork of Flodelle Creek drainage basin and may have similar significance in other areas.-from Authors

An unusual temperature dependence in the oxidation of oxycarbide layers on uranium

NASA Astrophysics Data System (ADS)

Ellis, Walton P.

1981-09-01

An anomalous temperature dependence has been observed for the oxidation kinetics of outermost oxycarbide layers on polycrystalline uranium metal. Normally, oxidation or corrosion reactions are expected to proceed more rapidly as the temperature is elevated. Thus, it came as a surprise when we observed that the removal of the outermost atomic layers of carbon from uranium oxycarbide by O 2 reproducibly proceeds at a much faster rate at 25°C than at 280°C.

An unusual temperature dependence in the oxidation of oxycarbide layers on uranium

NASA Astrophysics Data System (ADS)

Ellis, Walton P.

An anomalous temperature dependence has been observed for the oxidation kinetics of outermost oxycarbide layers on polycrystalline uranium metal. Normally, oxidation or corrosion reactions are expected to proceed more rapidly as the temperature is elevated. Thus, it came as a surprise when we observed that the removal of the outermost atomic layers of carbon from uranium oxycarbide by O 2 reproducibly proceeds at a much faster rate at 25°C than at 280°C.

Uranium hydrogeochemical and stream sediment reconnaissance of the Cortez NTMS Quadrangle, Colorado/Utah, including concentrations of forty-three additional elements

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

Warren, R.G.

1979-05-01

During the summers of 1976, 1977, and 1978, 598 water and 1657 sediment samples were collected from 1775 locations within the 19,600-km/sup 2/ area of the Cortez Quadrangle, Colorado and Utah. Water samples were collected from streams, springs, and wells; sediment samples were collected from stream channels (wet and dry) and from springs. Each water sample was analyzed for 13 elements, and each sediment sample was analyzed for 43 elements. Uranium concentrations in water samples range from below the detection limit of 0.02 to 241.47 ppB and have a median of 0.87 ppB and a mean of 3.80 ppB. Backgroundmore » uranium concentrations are 2 to 5 ppB in several nonmountainous regions but are much lower in mountainous areas, particularly in the northeastern portion of the quadrangle. Water samples containing high uranium concentrations (>20 ppB) generally are associated with high conductivities, high concentrations of other metallic elements, and geologic units, such as the Mancos shale, that are unfavorable for uranium mineralization. However, four ground-water samples exhibit high uranium concentrations without concomitant high conductivities or high concentrations of other metallic elements. Two of these samples were collected from sites in the Slick Rock U--V district, and two were collected in the Morrison formation in the southern portion of the quadrangle where large uranium deposits are not known. Water samples collected from the northwestern corner of the quadrangle uniformly exhibit background uranium values but generally contain high nickel concentrations. In this area, U--Cu (White Canyon-type) deposits are hosted primarily by the Shinarump member of the Chinle formation. Uranium concentrations in sediment samples range from 0.51 to 76.41 ppM and have a median of 2.76 ppM and a mean of 3.08 ppM. Background uranium and metallic element concentrations decrease to the southwest from the highest values in the northeastern portion of the quadrangle.« less

Helium on Venus - Implications for uranium and thorium

NASA Technical Reports Server (NTRS)

Prather, M. J.; Mcelroy, M. B.

1983-01-01

Helium is removed at an average rate of 10 to the 6th atoms per square centimeter per second from Venus's atmosphere by the solar wind following ionization above the plasmapause. The surface source of helium-4 on Venus is similar to that on earth, suggesting comparable abundances of crustal uranium and thorium.

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

NASA Astrophysics Data System (ADS)

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

2016-10-01

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

Mineral resource potential map of the Chama River Canyon Wilderness and contiguous roadless area, Rio Arriba County, New Mexico

USGS Publications Warehouse

Ridgley, Jennie L.; Light, Thomas D.

1983-01-01

The Chama River Canyon Wilderness and Roadless Area have a moderate to high potential for the presence of small deposits of copper with associated uranium and silver. These deposits, as yet undetected, would occur in the Permian Cutler Formation and in the lower part of the Triassic Chinle Formation, rock units that are, for the most part, present only in the subsurface. The presence of these deposits is inferred because such deposits occur in rocks of equivalent age in adjacent areas. Gypsum, of probable minable quality and quantity, occurs throughout the area. Oil and gas are possibly present in Pennsylvanian strata in the subsurface, although no drilling in the study area has tested this hypothesis. Other commodities, including noncopper-related uranium, kaolinite, chromium, vanadium, manganese, and bitumen, although present locally in anomalous concentrations, do not appear to constitute potential resources for these commodities.

Reconnaissance for radioactive deposits in eastern Alaska, 1952

USGS Publications Warehouse

Nelson, Arthur Edward; West, Walter S.; Matzko, John J.

1954-01-01

Reconnaissance for radioactive deposits was conducted in selected areas of eastern Alaska during 1952. Examination of copper, silver, and molybdenum occurrences and of a reported nickel prospect in the Slana-Nabesna and Chisana districts in the eastern Alaska Range revealed a maximum radioactivity of about 0.003 percent equivalent uranium. No appreciable radioactivity anomolies were indicated by aerial and foot traverses in the area. Reconnaissance for possible lode concentrations of uranium minerals in the vicinity of reported fluoride occurrences in the Hope Creek and Miller House-Circle Hot Springs areas of the Circle quadrangle and in the Fortymile district found a maximum of 0.055 percent equivalent uranium in a float fragment of ferruginous breccia in the Hope Creek area; analysis of samples obtained in the vicinity of the other fluoride occurrences showed a maximum of only 0.005 percent equivalent uranium. No uraniferous loads were discovered in the Koyukuk-Chandalar region, nor was the source of the monazite, previously reported in the placer concentrates from the Chandalar mining district, located. The source of the uranotheorianite in the placers at Gold Bench on the South Fork of the Koyukuk River was not found during a brief reconaissance, but a placer concentrate was obtained that contains 0.18 percent equivalent uranium. This concentrate is about ten times more radioactive than concentrates previously available from the area.

Preliminary investigation of the elemental variation and diagenesis of a tabular uranium deposit, La Sal Mine, San Juan County, Utah

USGS Publications Warehouse

Brooks, Robert A.; Campbell, John A.

1976-01-01

Ore in the La Sal mine, San Juan County, Utah, occurs as a typical tabular-type uranium deposit of the-Colorado Plateau. Uranium-vanadium occurs in the Salt Wash Member of the Jurassic Morrison Formation. Chemical and petrographic analyses were used to determine elemental variation and diagenetic aspects across the orebody. Vanadium is concentrated in the dark clay matrix, which constitutes visible ore. Uranium content is greater above the vanadium zone. Calcium, carbonate carbon, and lead show greater than fifty-fold increase across the ore zone, whereas copper and organic carbon show only a several-fold increase. Large molybdenum concentrations are present in and above the tabular layer, and large selenium concentrations occur below the uranium zone within the richest vanadium zone. Iron is enriched in the vanadium horizon. Chromium is depleted from above the ore and strongly enriched below. Elements that vary directly with the vanadium content include magnesium, iron, selenium, zirconium, strontium, titanium, lead, boron, yttrium, and scandium. The diagenetic sequence is as follows: (1) formation of secondary quartz overgrowths as cement; (2) infilling and lining of remaining pores with amber opaline material; (3) formation of vanadium-rich clay matrix, which has replaced overgrowths as well as quartz grains; (4) replacement of overgrowths and detrital grains by calcite; (5) infilling of pores with barite and the introduction of pyrite and marcasite.

Exploration for uranium-vanadium deposits by the U.S. Geological Survey in the Club Mesa area, Uravan district, Montrose County, Colorado

USGS Publications Warehouse

Boardman, R.L.; Litsey, L.R.; Bowers, H.E.

1958-01-01

Club Mesa is one of the most productive areas for uranium-vanadium ore in southwestern Colorago. The average grade of this ore has ranged from about 0.25 to 1.50 percent U3O8 and 1.5 to 5.0 percent V2O5.

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

USGS Publications Warehouse

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

1983-01-01

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

Uranium distribution in pseudowollastonite slag from a phosphorus furnace

USGS Publications Warehouse

Young, Edward; Altschuler, Zalman S.

1956-01-01

Silicate slag from the Victor Chemical Company phosphorus furnace at Tarpon Springs, Fla., has been found to consist essentially of pseudowollastonite, α-CaSiO3. The first-formed crystals are euhedral laths which form a mesh making up most of the slag. As the slag continues to solidify, its composition changes slightly and more equant, subhedral crystals of pseudowollastonite are deposited within the framework of the earlier material. Finally, anherdral masses of fibrous, poorly crystallized material are deposited in the remaining pore spaces which are not always completely filled. Spherules of iron phosphide, Fe2P, occur very sparsely in the slag as inclusions from the immiscible iron phosphide melt. Uranium content increases in the later crystal products of the slag, and by heavy-liquid fractionation it has been possible to segregate partially the phases and to obtain a fourfold concentration of uranium in 5 percent of the material and a twofold concentration in 30 percent of the material. Nuclear-emulsion studies indicate that the last phases of the silicate slag are actually eight times as radioactive as the early phases. In addition, the iron phosphide spherules are comparably enriches in uranium.

Spectroscopic characterization of Greek dolomitic marble surface interacted with uranium and thorium in aqueous solutions

NASA Astrophysics Data System (ADS)

Godelitsas, A.; Kokkoris, M.; Chatzitheodoridis, E.; Misaelides, P.

2008-05-01

The surface of a typical Greek (Thassian) dolomitic marble was studied after interaction with U- and Th-containing aqueous solutions (1000 mg/L, free-drift experiments for 1 week at atmospheric PCO2), using 12C-RBS and Laser μ-Raman spectroscopy. Powder-XRD and SEM-EDS were also applied to investigate the phases deposited on the surface of the interacted samples. The obtained results indicated a considerable removal of U from the aqueous medium mainly due to massive surface precipitation of amorphous UO2-hydroxide phases forming a relatively thick (μm-sized) coating on the carbonate substrate. The interaction of Th with dolomitic marble surface is also intense leading to a formation of an amorphous Th-hydroxide layer of similar thickness but of significantly lower elemental atomic proportion.

Study of polyethyleneimine- and amidoxime-functionalized hybrid biomass of Spirulina (Arthrospira) platensis for adsorption of uranium (VI) ion.

PubMed

Bayramoglu, Gulay; Akbulut, Aydin; Arica, M Yakup

2015-11-01

This study investigates the potential application of the polyethyleneimine- (PEI) and amidoxime-modified Spirulina (Arthrospira) platensis biomasses for the removal of uranium ion in batch mode using the native biomass as a control system. The uranium ion adsorption was also characterized by attenuated total reflectance Fourier transform infrared (ATR-FTIR) spectra, zeta potential analysis, and surface area measurement studies. The effects of pH, biomass amount, contact time, initial uranium ion concentration, and ionic strength were evaluated by using native and modified algal biomass preparations. The uranium ion removal was rapid, with more than 70% of total adsorption taking place in 40 min, and equilibrium was established within 60 min. From the experimental data, it was found that the amount of adsorption uranium ion on the algal preparations decreased in the following series: amidoxime-modified algal biomass > PEI-modified algal biomass > native algal biomass. Maximum adsorption capacities of amidoxime- and PEI-modified, and native algal biomasses were found to be 366.8, 279.5, and 194.6 mg/g, respectively, in batchwise studies. The adsorption rate of U(VI) ion by amidoxime-modified algal biomass was higher than those of the native and PEI-modified counterparts. The adsorption processes on all the algal biomass preparations followed by the Dubinin-Radushkevitch (D-R) and Temkin isotherms and pseudo-second-order kinetic models. The thermodynamic parameters were determined at four different temperatures (i.e., 15, 25, 35, and 45 °C) using the thermodynamics constant of the Temkin isotherm model. The ΔH° and ΔG° values of U(VI) ion adsorption on algal preparations show endothermic heat of adsorption; higher temperatures favor the process. The native and modified algal biomass preparations were regenerated using 10 mM HNO3. These results show that amidoxime-modified algal biomass can be a potential candidate for effective removal of U(VI) ion from aqueous solution.

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

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

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

1985-01-01

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

Preliminary report on the Comet area, Jefferson County, Montana

USGS Publications Warehouse

Becraft, George Earle

1952-01-01

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

Uranium isotopes fingerprint biotic reduction

DOE PAGES

Stylo, Malgorzata; Neubert, Nadja; Wang, Yuheng; ...

2015-04-20

Knowledge of paleo-redox conditions in the Earth’s history provides a window into events that shaped the evolution of life on our planet. The role of microbial activity in paleo-redox processes remains unexplored due to the inability to discriminate biotic from abiotic redox transformations in the rock record. The ability to deconvolute these two processes would provide a means to identify environmental niches in which microbial activity was prevalent at a specific time in paleo-history and to correlate specific biogeochemical events with the corresponding microbial metabolism. Here, we demonstrate that the isotopic signature associated with microbial reduction of hexavalent uranium (U),more » i.e., the accumulation of the heavy isotope in the U(IV) phase, is readily distinguishable from that generated by abiotic uranium reduction in laboratory experiments. Thus, isotope signatures preserved in the geologic record through the reductive precipitation of uranium may provide the sought-after tool to probe for biotic processes. Because uranium is a common element in the Earth’s crust and a wide variety of metabolic groups of microorganisms catalyze the biological reduction of U(VI), this tool is applicable to a multiplicity of geological epochs and terrestrial environments. The findings of this study indicate that biological activity contributed to the formation of many authigenic U deposits, including sandstone U deposits of various ages, as well as modern, Cretaceous, and Archean black shales. In addition, engineered bioremediation activities also exhibit a biotic signature, suggesting that, although multiple pathways may be involved in the reduction, direct enzymatic reduction contributes substantially to the immobilization of uranium.« less

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

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

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

1980-06-01

During the summer and fall of 1977, 533 water and 1226 sediment samples were collected from 1740 locations within the 18,000 km/sup 2/ area of the Newcastle quadrangle, Wyoming. Water samples were collected from wells and springs; sediment samples were collected from stream channels and from springs. Each water sample was analyzed for uranium, and each sediment sample was analyzed for 43 elements, including uranium and thorium. Uranium concentrations in water samples range from below the detection limit of 0.02 ppB to 702.26 ppB and have a median of 1.73 ppB and a mean of 11.76 ppB. Water samples containingmore » high uranium concentrations (>20 ppB) generally are associated with known uranium mining activity or units known to be uranium bearing. About one-third of the water samples containing high uranium concentrations were collected from locations within the Pumpkin Buttes and Turnercrest-Ross Districts. Nearly half of the water samples containing high uranium concentrations were collected from locations just west of the Monument Hill and Highland Flats-Box Creek Districts. Similar anomalous uranium concentrations in this region have been reported updip from Exxon's Highland uranium deposits. High uranium concentrations were also found associated with the Lance Creek-Old Woman Anticline District.« less

Plant-uptake of uranium: Hydroponic and soil system studies

USGS Publications Warehouse

Ramaswami, A.; Carr, P.; Burkhardt, M.

2001-01-01

Limited information is available on screening and selection of terrestrial plants for uptake and translocation of uranium from soil. This article evaluates the removal of uranium from water and soil by selected plants, comparing plant performance in hydroponic systems with that in two soil systems (a sandy-loam soil and an organic-rich soil). Plants selected for this study were Sunflower (Helianthus giganteus), Spring Vetch (Vicia sativa), Hairy Vetch (Vicia villosa), Juniper (Juniperus monosperma), Indian Mustard (Brassica juncea), and Bush Bean (Phaseolus nanus). Plant performance was evaluated both in terms of the percent uranium extracted from the three systems, as well as the biological absorption coefficient (BAC) that normalized uranium uptake to plant biomass. Study results indicate that uranium extraction efficiency decreased sharply across hydroponic, sandy and organic soil systems, indicating that soil organic matter sequestered uranium, rendering it largely unavailable for plant uptake. These results indicate that site-specific soils must be used to screen plants for uranium extraction capability; plant behavior in hydroponic systems does not correlate well with that in soil systems. One plant species, Juniper, exhibited consistent uranium extraction efficiencies and BACs in both sandy and organic soils, suggesting unique uranium extraction capabilities.

Construction of the Syngonium podophyllum-Pseudomonas sp. XNN8 Symbiotic Purification System and Investigation of Its Capability of Remediating Uranium Wastewater.

PubMed

Deng, Qin-Wen; Wang, Yong-Dong; Ding, De-Xin; Hu, Nan; Sun, Jing; He, Jia-Dong; Xu, Fei

2017-02-01

The endophyte Pseudomonas sp. XNN8 was separated from Typha orientalis which can secrete indole-3-acetic acid and 1-aminocyclopropane-1-carboxylate deaminase and siderophores and has strong resistance to uranium it was then colonized in the Syngonium podophyllum; and the S. podophyllum-Pseudomonas sp. XNN8 symbiotic purification system (SPPSPS) for uranium-containing wastewater was constructed. Afterwards, the hydroponic experiments to remove uranium from uranium-containing wastewater by the SPPSPS were conducted. After 24 days of treatment, the uranium concentrations of the wastewater samples with uranium concentrations between 0.5 and 5.0 mg/L were lowered to below 0.05 mg/L. Furthermore, the uranium in the plants was assayed using Fourier transform infrared spectroscopy (FTIR) and extended X-ray absorption fine structure (EXAFS) spectroscopy. The Pseudomonas sp. XNN8 was found to generate substantial organic groups in the roots of the Syngonium podophyllum, which could improve the complexing capability of S. podophyllum for uranium. The uranium in the roots of S. podophyllum was found to be the uranyl phosphate (47.4 %) and uranyl acetate (52.6 %).

Permissive tracts for uranium deposits in Mauritania (phase V, deliverable 80): Chapter N1 in Second projet de renforcement institutionnel du secteur minier de la République Islamique de Mauritanie (PRISM-II)

USGS Publications Warehouse

Fernette, Gregory; Horton, John D.

2012-01-01

This report contains the USGS results of the PRISM-II Mauritania Minerals Project and is presented in cooperation with the Ministry of Petroleum, Energy, and Mines of the Islamic Republic of Mauritania. The Report is composed of separate chapters consisting of multidisciplinary interpretive reports with accompanying plates on the geology, structure, geochronology, geophysics, hydrogeology, geochemistry, remote sensing (Landsat TM and ASTER), and SRTM and ASTER digital elevation models of Mauritania. The syntheses of these multidisciplinary data formed the basis for additional chapters containing interpretive reports on 12 different commodities and deposit types known to occur in Mauritania, accompanied by countrywide mineral resource potential maps of each commodity/deposit type. The commodities and deposit types represented include: (1) Ni, Cu, PGE, and Cr deposits hosted in ultramafic rocks; (2) orogenic, Carlin-like, and epithermal gold deposits; (3) polymetallic Pb-Zn-Cu vein deposits; (4) sediment-hosted Pb-Zn-Ag deposits of the SEDEX and Mississippi Valley-type; (5) sediment-hosted copper deposits; ( 6) volcanogenic massive sulfide deposits; (7) iron oxide copper-gold deposits; (8) uranium deposits; (9) Algoma-, Superior-, and oolitic-type iron deposits; (10) shoreline Ti-Zr placer deposits; (11) incompatible element deposits hosted in pegmatites, alkaline rocks, and carbonatites, and; (12) industrial mineral deposits. Additional chapters include the Mauritanian National Mineral Deposits Database are accompanied by an explanatory text and the Mauritania Minerals Project GIS that contains all of the interpretive layers created by USGS scientists. Raw data not in the public domain may be obtained from the Ministry of Petroleum, Energy, and Mines in Nouakchott, Mauritania.

MULTIPLE CONTAMINANT ISSUES AND TECHNOLOGIES

EPA Science Inventory

The presentation provides information on the removal of arsenic with either nitrate, uranium, radium, radon and antimony as a co-contaminant. The technologies discussed as having the capability of removing arsenic and one of the other contaminants are reverse osmosis, anion and ...

Analysis of solid uranium samples using a small mass spectrometer

NASA Astrophysics Data System (ADS)

Kahr, Michael S.; Abney, Kent D.; Olivares, José A.

2001-07-01

A mass spectrometer for isotopic analysis of solid uranium samples has been constructed and evaluated. This system employs the fluorinating agent chlorine trifluoride (ClF 3) to convert solid uranium samples into their volatile uranium hexafluorides (UF 6). The majority of unwanted gaseous byproducts and remaining ClF 3 are removed from the sample vessel by condensing the UF 6 and then pumping away the unwanted gases. The UF 6 gas is then introduced into a quadrupole mass spectrometer and ionized by electron impact ionization. The doubly charged bare metal uranium ion (U 2+) is used to determine the U 235/U 238 isotopic ratio. Precision and accuracy for several isotopic standards were found to be better than 12%, without further calibration of the system. The analysis can be completed in 25 min from sample loading, to UF 6 reaction, to mass spectral analysis. The method is amenable to uranium solid matrices, and other actinides.

Molten salt extraction of transuranic and reactive fission products from used uranium oxide fuel

DOEpatents

Herrmann, Steven Douglas

2014-05-27

Used uranium oxide fuel is detoxified by extracting transuranic and reactive fission products into molten salt. By contacting declad and crushed used uranium oxide fuel with a molten halide salt containing a minor fraction of the respective uranium trihalide, transuranic and reactive fission products partition from the fuel to the molten salt phase, while uranium oxide and non-reactive, or noble metal, fission products remain in an insoluble solid phase. The salt is then separated from the fuel via draining and distillation. By this method, the bulk of the decay heat, fission poisoning capacity, and radiotoxicity are removed from the used fuel. The remaining radioactivity from the noble metal fission products in the detoxified fuel is primarily limited to soft beta emitters. The extracted transuranic and reactive fission products are amenable to existing technologies for group uranium/transuranic product recovery and fission product immobilization in engineered waste forms.

Biosorption of heavy metals and uranium from dilute solutions

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

Schneider, I.A.H.; Misra, M.; Smith, R.W.

1995-08-01

Eichhornia crassipes approaches being a scourge in many parts of the world, choking waterways and hindering transport upon them. At the same time it is known to readily abstract heavy metal ions from water and, thus, aids in the removal of heavy metals found in such waters. This paper considers the possibility of using specific parts of the plant as an inexpensive adsorbent for the removal of heavy metals from contaminated chemical and mining industry waste waters. In particular the root of the plant was found to be an excellent accumulator of heavy metal ions including uranium from solution. Itmore » is also suggested that dried roots of the plant might be placed in simple bags and used in a very low cost metal ion removal system.« less

Volumetric determination of uranium titanous sulfate as reductant before oxidimetric titration

USGS Publications Warehouse

Wahlberg, J.S.; Skinner, D.L.; Rader, L.F.

1957-01-01

Need for a more rapid volumetric method for the routine determination of uranium in uranium-rich materials has led to the development of a method that uses titanous sulfate as a reductant before oxidimetric titration. Separation of the hydrogen sulfide group is not necessary. Interfering elements precipitated by cupferron are removed by automatic filtrations made simultaneously rather than by the longer chloroform extraction method. Uranium is reduced from VI to IV by addition of an excess of titanous sulfate solution, cupric ion serving as an indicator by forming red metallic copper when reduction is complete. The copper is reoxidized by addition of mercuric perchlorate. The reduced uranium is then determined by addition of excess ferric sulfate and titration with ceric sulfate. The method has proved to be rapid, accurate, and economical.

Geochemical investigation of UMTRAP designated site at Durango, Colorado

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

Markos, G.; Bush, K.J.

1983-09-01

This report is the result of a geochemical investigation of the former uranium mill and tailings site at Durango, Colorado. This is one in a series of site specific geochemical investigations performed on the inactive uranium mill tailings included in the UMTRA Project. The objectives of the investigation are to characterize the geochemistry, to determine the contaminant distribution resulting from the former milling activities and tailings, and to infer chemical pathways and transport mechanisms from the contaminant distribution. The results will be used to model contaminant migration and to develop criteria for long-term containment media such as a cover systemmore » which is impermeable to contaminant migration. This report assumes a familiarity with the hydrologic conditions of the site and the geochemical concepts underlying the investigation. The results reported are based on a one-time sampling of waters and solid material from the background, the area adjacent to the site, and the site. The solid samples are water extracted remove easily soluble salts and acids extracted to remove cabonates and hydroxides. The water extracts and solid samples were analyzed for the major and trace elements. A limited number of samples were analyzed for radiological components. The report includes the methods of sampling, sample processing, analysis, and data interpretation. Three major conclusions are: (1) carbonate salts and low TDS characterize the tailings; (2) the adjacent area and raffinate ponds contain contaminants deposited by a single event of fluid permeation of the soils; and (3) the Animas River adjacent to the site has elevated gross alpha activity attributed to /sup 226/Ra in the sediments derived from the tailings or milling activities.« less

Microbiological, Geochemical and Hydrologic Processes Controlling Uranium Mobility: An Integrated Field-Scale Subsurface Research Challenge Site at Rifle, Colorado, Quality Assurance Project Plan

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

Fix, N. J.

The U.S. Department of Energy (DOE) is cleaning up and/or monitoring large, dilute plumes contaminated by metals, such as uranium and chromium, whose mobility and solubility change with redox status. Field-scale experiments with acetate as the electron donor have stimulated metal-reducing bacteria to effectively remove uranium [U(VI)] from groundwater at the Uranium Mill Tailings Site in Rifle, Colorado. The Pacific Northwest National Laboratory and a multidisciplinary team of national laboratory and academic collaborators has embarked on a research proposed for the Rifle site, the object of which is to gain a comprehensive and mechanistic understanding of the microbial factors andmore » associated geochemistry controlling uranium mobility so that DOE can confidently remediate uranium plumes as well as support stewardship of uranium-contaminated sites. This Quality Assurance Project Plan provides the quality assurance requirements and processes that will be followed by the Rifle Integrated Field-Scale Subsurface Research Challenge Project.« less

Recent developments in uranium exploration using the U.S. geological survey's mobile helium detector

USGS Publications Warehouse

Reimer, G.M.; Denton, E.H.; Friedman, I.; Otton, J.K.

1979-01-01

A mobile mass spectrometer to measure He concentrations has been developed by the U.S. Geological Survey. This instrument has been tested in areas of known uranium deposits, and He anomalies have been found in both soil gas and water. A gas sample is collected in a hypodermic syringe, injected into the spectrometer, and analyzed for He. Over 100 analyses a day can be performed with a sensitivity of 10 parts per billion (ppb). One detailed study conducted in Weld County, Colorado, shows that values for He in soil gas can be contoured to outline an anomalous area and that the anomaly is displaced from the deposit in the direction of groundwater flow. Other studies include the Schwartzwalder uranium mine, Jefferson County, Colorado, where He anomalies may be related to geologic structure; near Ambrosia Lake, New Mexico, where the location of He anomalies are related to groundwater movement; and tests for diurnal effects showing only slight variations probably related to soil-moisture content. ?? 1979.

METHOD OF PURIFYING URANIUM METAL

DOEpatents

Blanco, R.E.; Morrison, B.H.

1958-12-23

The removal of lmpurities from uranlum metal can be done by a process conslstlng of contacting the metal with liquid mercury at 300 icient laborato C, separating the impunitycontalnlng slag formed, cooling the slag-free liquld substantlally below the point at which uranlum mercurlde sollds form, removlng the mercury from the solids, and recovering metallic uranium by heating the solids.

Room temperature electrodeposition of actinides from ionic solutions

DOEpatents

Hatchett, David W.; Czerwinski, Kenneth R.; Droessler, Janelle; Kinyanjui, John

2017-04-25

Uranic and transuranic metals and metal oxides are first dissolved in ozone compositions. The resulting solution in ozone can be further dissolved in ionic liquids to form a second solution. The metals in the second solution are then electrochemically deposited from the second solutions as room temperature ionic liquid (RTIL), tri-methyl-n-butyl ammonium n-bis(trifluoromethansulfonylimide) [Me.sub.3N.sup.nBu][TFSI] providing an alternative non-aqueous system for the extraction and reclamation of actinides from reprocessed fuel materials. Deposition of U metal is achieved using TFSI complexes of U(III) and U(IV) containing the anion common to the RTIL. TFSI complexes of uranium were produced to ensure solubility of the species in the ionic liquid. The methods provide a first measure of the thermodynamic properties of U metal deposition using Uranium complexes with different oxidation states from RTIL solution at room temperature.

WHETSTONE ROADLESS AREA, ARIZONA.

USGS Publications Warehouse

Wrucke, Chester T.; McColly, Robert A.

1984-01-01

A mineral survey conducted has shown that areas in and adjacent to the Whetstone Roadless Area, Arizona have a substantiated resource potential for copper, lead, gold, silver, and quartz, and a probable mineral-resource potential for copper silver, lead, gold, molybdenum, tungsten, uranium, and gypsum. Copper and silver occur in a small vein deposit in the southwestern part of the roadless area. Copper, lead, silver, gold, and molybdenum are known in veins associated with a porphyry copper deposit in a reentrant near the southern border of the roadless area. Vein deposits of tungsten and uranium are possible in the northeast part of the roadless area near areas of known production of these commodities. Demonstrated resources of quartz for smelter flux extend into the roadless area from the Ricketts mine. Areas of probable potential for gypsum resources also occur within the roadless area. No potential for fossil fuel resources was identified in the study.

Aftermath of Uranium Ore Processing on Floodplains: Lasting Effects of Uranium on Soil and Microbes

NASA Astrophysics Data System (ADS)

Tang, H.; Boye, K.; Bargar, J.; Fendorf, S. E.

2016-12-01

A former uranium ore processing site located between the Wind River and the Little Wind River near the city of Riverton, Wyoming, has generated a uranium plume in the groundwater within the floodplain. Uranium is toxic and poses a threat to human health. Thus, controlling and containing the spread of uranium will benefit the human population. The primary source of uranium was removed from the processing site, but a uranium plume still exists in the groundwater. Uranium in its reduced form is relatively insoluble in water and therefore is retained in organic rich, anoxic layers in the subsurface. However, with the aid of microbes uranium becomes soluble in water which could expose people and the environment to this toxin, if it enters the groundwater and ultimately the river. In order to better understand the mechanisms controlling uranium behavior in the floodplains, we examined sediments from three sediment cores (soil surface to aquifer). We determined the soil elemental concentrations and measured microbial activity through the use of several instruments (e.g. Elemental Analyzer, X-ray Fluorescence, MicroResp System). Through the data collected, we aim to obtain a better understanding of how the interaction of geochemical factors and microbial metabolism affect uranium mobility. This knowledge will inform models used to predict uranium behavior in response to land use or climate change in floodplain environments.

National Uranium Resource Evaluation: Palestine Quadrangle, Texas and Louisiana

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

McGowen, M.; Basciano, J.; Fose, F.G. Jr.

1982-09-01

The uranium resource potential of the Palestine Quadrangle, Texas and Louisiana, was evaluated to a depth of 1500 m (5000 ft) using criteria established for the National Uranium Resource Evaluation program. Data derived from geochemical analyses of surface samples (substrate, soil, and stream sediment) in conjunction with hydrochemical data from water wells were used to evaluate geologic environments as being favorable or unfavorable for the occurrence of uranium deposits. Two favorable environments have been identified in the Palestine Quadrangle: potential deposits of modified Texas roll-type in fluvial channels and associated facies within the Yegua Formation, and potential occurrences along mineralizationmore » fronts associated with the Elkhart Graben and Mount Enterprise fault system. Unfavorable environments include: Cretaceous shales and limestones, Tertiary fine-grained marine sequences, Tertiary sandstone units that exhibit favorable host-rock characteristics but fail to show significant syngenetic or epigenetic mineralization, and Quaternary sands and gravels. Unevaluated units include the Woodbine Group (Upper Cretaceous), Jackson Group (Tertiary), and Catahoula Formation (Tertiary). The subsurface interval of the Jackson Group and Catahoula Formation contains depositional facies that may represent favorable environments; however, the evaluation of these units is inconclusive because of the general lack of shallow subsurface control and core material. The Woodbine Group, restricted to the subsurface except for a small exposure over Palestine Dome, occurs above 1500 m (5000 ft) in the northwest quarter of the quadrangle. The unit exhibits favorable host-rock characteristics, but the paucity of gamma logs and cores, as well as the lack of hydrogeochemical and stream-sediment reconnaissance data, makes evaluation of the unit difficult.« less

Effect of pH and Pressure on Uranium Removal from Drinking Water Using NF/RO Membranes.

PubMed

Schulte-Herbrüggen, Helfrid M A; Semião, Andrea J C; Chaurand, Perrine; Graham, Margaret C

2016-06-07

Groundwater is becoming an increasingly important drinking water source. However, the use of groundwater for potable purposes can lead to chronic human exposure to geogenic contaminants, for example, uranium. Nanofiltration (NF) and reverse osmosis (RO) processes are used for drinking water purification, and it is important to understand how contaminants interact with membranes since accumulation of contaminants to the membrane surface can lead to fouling, performance decline and possible breakthrough of contaminants. During the current study laboratory experiments were conducted using NF (TFC-SR2) and RO (BW30) membranes to establish the behavior of uranium across pH (3-10) and pressure (5-15 bar) ranges. The results showed that important determinants of uranium-membrane sorption interactions were (i) the uranium speciation (uranium species valence and size in relation to membrane surface charge and pore size) and (ii) concentration polarization, depending on the pH values. The results show that it is important to monitor sorption of uranium to membranes, which is controlled by pH and concentration polarization, and, if necessary, adjust those parameters controlling uranium sorption.

COORDINATION COMPOUND-SOLVENT EXTRACTION PROCESS FOR URANIUM RECOVERY

DOEpatents

Reas, W.H.

1959-03-10

A method is presented for the separation of uranium from aqueous solutions containing a uranyl salt and thorium. Thc separation is effected by adding to such solutions an organic complexing agent, and then contacting the solution with an organic solvent in which the organic complexing agent is soluble. By use of the proper complexing agent in the proper concentrations uranium will be complexed and subsequently removed in the organic solvent phase, while the thorium remains in the aqueous phase. Mentioned as suitable organic complexing agents are antipyrine, bromoantipyrine, and pyramidon.

METHOD OF ELECTROPOLISHING URANIUM

DOEpatents

Walker, D.E.; Noland, R.A.

1959-07-14

A method of electropolishing the surface of uranium articles is presented. The process of this invention is carried out by immersing the uranium anticle into an electrolyte which contains from 35 to 65% by volume sulfuric acid, 1 to 20% by volume glycerine and 25 to 50% by volume of water. The article is made the anode in the cell and polished by electrolyzing at a voltage of from 10 to 15 volts. Discontinuing the electrolysis by intermittently withdrawing the anode from the electrolyte and removing any polarized film formed therein results in an especially bright surface.

PROCESS OF RECOVERING URANIUM

DOEpatents

Price, T.D.; Jeung, N.M.

1958-06-17

An improved precipitation method is described for the recovery of uranium from aqueous solutions. After removal of all but small amounts of Ni or Cu, and after complexing any iron present, the uranium is separated as the peroxide by adding H/sub 2/O/sub 2/. The improvement lies in the fact that the addition of H/sub 2/O/sub 2/ and consequent precipitation are carried out at a temperature below the freezing; point of the solution, so that minute crystals of solvent are present as seed crystals for the precipitation.

Vacuum ultraviolet spectra of uranium hexafluoride/argon mixtures

NASA Technical Reports Server (NTRS)

Krascella, N. L.

1976-01-01

The transmission properties of room temperature helium at pressures up to 20 atmospheres were determined in the wavelength range from 80 to 300 nm. Similarly, the transmission properties of uranium hexafluoride at 393 K (pressures less than 1.0 mm) were determined in the wavelength range from 80 to about 120 nm. The results show that high pressure helium is sufficiently transparent in the vacuum ultraviolet region (provided trace contaminants are removed) to be utilized as a transparent purge gas in future fissioning gaseous uranium plasma reactor experiments. Absorption cross sections for uranium hexafluoride were calculated from the data between 80 and 120 nm and were of the order of 10 to the -17 power sq cm.

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

Rabin, S.A.; Lotts, A.L.; Hammond, J.P.

Uranium --molybdenum alloy rods containing from 10 to 15 wt% Mo and 1/16- in. in diameter were successfully fabricated by hot rotary swaging, followed by machining to remove the protective sheathing (Inconel with molybdenum barrier). Structurally strong rods with densities greater than 95% of theoretical were produced from both calciumreduced uranium mixed with hydrogen-reduced molybdenum and acid-cleaned, prealloyed shot when reduced in area about 55% at 1050 or 1100 deg C. Alloy homogeneity was good with prealloyed powders; however, traces of molybdenum -rich, gamma phase persisted in the elemental uranium -molybdenum material after swaging at 1100 deg C. Swagings embodyingmore » hydride uranium or oxide- contaminated prealloyed shot were unsatisfactory because of insufficient consolidation or poor interparticle bonding. (auth)« less

Distribution of calcretes and gypcretes in southwestern United States and their uranium favorability, based on a study of deposits in Western Australia and South West Africa (Namibia)

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

Carlisle, D.; Merifield, P.M.; Orme, A.R.

Calcrete, dolocrete, and gypcrete carnotite are abundant in western Australia and Namib Desert, although only a few are of ore grade. The geology of these deposits are described. A genetic classification of calcretes emphasizing uranium favorability was developed, based on the distinction between pedogenic and nonpedogenic processes. Similarities between western Australia and South West Africa give support for the conclusions that lateral transport of U in groundwater is essential to ore deposition and that bedrock barriers or constrictions which narrow the channel of subsurface flow or force the water close to the land surface, greatly favor the formation of uraniferousmore » calcretes. Criteria for uranium favorability deduced from the Australian and South West African studies were applied in a preliminary way to the southern Basin and Range Province of U.S. The procedure is to search for areas in which nonpedogenic calcrete or gypcrete may have developed. A caliche distribution map was compiled from soil survey and field data. Many areas were visited and some of the more interesting are described briefly, including parts of Clark County, Nevada, with occurrences of carnotite in calcrete. (DLC)« less

Plasma core reactor simulations using RF uranium seeded argon discharges

NASA Technical Reports Server (NTRS)

Roman, W. C.

1975-01-01

An experimental investigation was conducted using the United Technologies Research Center (UTRC) 80 kW and 1.2 MW RF induction heater systems to aid in developing the technology necessary for designing a self-critical fissioning uranium plasma core reactor (PCR). A nonfissioning, steady-state RF-heated argon plasma seeded with pure uranium hexafluoride (UF6) was used. An overall objective was to achieve maximum confinement of uranium vapor within the plasma while simultaneously minimizing the uranium compound wall deposition. Exploratory tests were conducted using the 80 kW RF induction heater with the test chamber at approximately atmospheric pressure and discharge power levels on the order of 10 kW. Four different test chamber flow configurations were tested to permit selection of the configuration offering the best confinement characteristics for subsequent tests at higher pressure and power in the 1.2 MW RF induction heater facility.

Selected annotated bibliography of the geology and occurrence of uranium-bearing marine black shales in the United States

USGS Publications Warehouse

Fix, Carolyn E.

1956-01-01

The bibliography consists of annotations or abstracts of selected reports that pertain to the geology and occurrence of uranium in marine black shales and their metamorphic equivalents in the United States. Only those reports that were available to the public prior to June 30, 1956, are included. Most of the reports may be consulted in the larger public, university, or scientific libraries. A few reports that have been released to the public in open file may be consulted at designated offices of the Geological Survey. An effort has been made to include only those references to shales whose uranium is believed to be of syngenetic origin and whose major source of radioactivity is uranium. Many general papers on the geology of uranium deposits refer to marine black shales, and some of these general papers have been included.

Sustainability of uranium mining and milling: toward quantifying resources and eco-efficiency.

PubMed

Mudd, Gavin M; Diesendorf, Mark

2008-04-01

The mining of uranium has long been a controversial public issue, and a renewed debate has emerged on the potential for nuclear power to help mitigate against climate change. The central thesis of pro-nuclear advocates is the lower carbon intensity of nuclear energy compared to fossil fuels, although there remains very little detailed analysis of the true carbon costs of nuclear energy. In this paper, we compile and analyze a range of data on uranium mining and milling, including uranium resources as well as sustainability metrics such as energy and water consumption and carbon emissions with respect to uranium production-arguably the first time for modern projects. The extent of economically recoverable uranium resources is clearly linked to exploration, technology, and economics but also inextricably to environmental costs such as energy/water/chemicals consumption, greenhouse gas emissions, and social issues. Overall, the data clearly show the sensitivity of sustainability assessments to the ore grade of the uranium deposit being mined and that significant gaps remain in complete sustainability reporting and accounting. This paper is a case study of the energy, water, and carbon costs of uranium mining and milling within the context of the nuclear energy chain.

SEPARATION OF PLUTONIUM

DOEpatents

Maddock, A.G.; Smith, F.

1959-08-25

A method is described for separating plutonium from uranium and fission products by treating a nitrate solution of fission products, uranium, and hexavalent plutonium with a relatively water-insoluble fluoride to adsorb fission products on the fluoride, treating the residual solution with a reducing agent for plutonium to reduce its valence to four and less, treating the reduced plutonium solution with a relatively insoluble fluoride to adsorb the plutonium on the fluoride, removing the solution, and subsequently treating the fluoride with its adsorbed plutonium with a concentrated aqueous solution of at least one of a group consisting of aluminum nitrate, ferric nitrate, and manganous nitrate to remove the plutonium from the fluoride.

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

NASA Astrophysics Data System (ADS)

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.

Exogenous contamination of uranium in human scalp hair.

PubMed

Muikku, Maarit; Heikkinen, Tarja

2012-06-01

The use of human scalp hair as a bioindicator of occupational or environmental exposure has been the subject of some debate over the years. One problem is how to distinguish internal contamination from external contamination. In this study, possibility that elevated levels of natural uranium in human hair are partly due to the exogenously bound uranium from uranium-rich household water was tested. Hair samples from six adult volunteers were cut and then exposed externally to uranium by using washing water with highly elevated levels of natural uranium. After that, and before making the analysis using inductively coupled plasma mass spectrometry (ICP-MS), the samples were washed using two commonly used washing procedures in order to remove external contamination. No quantitative information was gained in the tests, but it was shown that the use of uranium-rich water when washing hair affects the uranium concentration in hair. Although the samples were cleaned according to widely used washing procedures before the analysis, the uranium concentrations in hair were about three orders of magnitude higher after the tests. The possibility of external contamination should be kept in mind, especially when considering hair as an excretion pathway for estimating internal dose.

Recovery of tritium from tritiated molecules

DOEpatents

Swansiger, William A.

1987-01-01

A method of recovering tritium from tritiated compounds comprises the steps of heating tritiated water and other co-injected tritiated compounds in a preheater to temperatures of about 600.degree. C. The mixture is injected into a reactor charged with a mixture of uranium and uranium dioxide. The injected mixture undergoes highly exothermic reactions with the uranium causing reaction temperatures to occur in excess of the melting point of uranium, and complete decomposition of the tritiated compounds to remove tritium therefrom. The uranium dioxide functions as an insulating material and heat sink preventing the reactor side walls from attaining reaction temperatures to thereby minimize tritium permeation rates. The uranium dioxide also functions as a diluent to allow for volumetric expansion of the uranium as it is converted to uranium dioxide. The reactor vessel is preferably stainless steel of sufficient mass so as to function as a heat sink preventing the reactor side walls from approaching high temperatures. A disposable copper liner extends between the reaction chamber and stainless steel outer vessel to prevent alloying of the uranium with the outer vessel. Apparatus used to carry out the method of the invention is also disclosed.

Egypt/United States cooperative energy assessment. Volume II, Annex 1. Energy resources of Egypt

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

Not Available

1979-04-01

This report contains the findings and recommendations of the US Geological Survey geologists assigned to survey Egypts indigenous energy resources. Data on oil and gas, coal and oil shale, uranium and thorium, geothermal energy, water resources, and energy related minerals are presented. Thirty-nine oil and gas fields have been discovered in Egypt, proven reserves of oil were estimated to be 1,559,000,000 barrels in 1976. The Egyptian government hopes to attain a production rate of 1 million barrels a day in 1982. While the Gulf of Suez basin holds the most immediate prospects, the most promising frontier regions are the unexploredmore » broad expanses of the Western Desert, the Nile Basin and the Northern Sinai while oil shales have been found in Egypt, they are only 10 to 15 feet thick and their hydrocarbon content is low. Recovery would not be economic. Coal deposits contain reserves estimated at 95 to 112 million tons. Only 1 deposit is deemed workable under present conditions of technology and economy. No uranium and thorium are being produced however geological conditions appear favorable for finding uranium deposits using appropriate programs of prospecting, exploration and development. The potential for development of low-level sources of geothermal energy in Egypt is good; there is no evidence of a high-temperature source or a vapor-dominated system. The Nile is the primary source of water. In the western desert, the Nubian aquifer supplies water for irrigation. Energy related minerals are generally found in uneconomic concentrations or not at all. However, deposits of material used in cement making and some iron ore for steel making are available. Deposits of manganese may become available upon return of the Sinai to Egypt. 44 figures, 24 tables. (DMC)« less

Recovery Act Weekly Video: 200 Area Asbestos Removal, U-Ancillary Demolition, 200 West Transfer Building Footings

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

None

A weekly update of the Recovery Act at work. Demolition of U-Ancillary that was contaminated with uranium and asbestos as well as removing asbestos from the Steam Generation Plant in the 200 East Area.

Recovery Act Weekly Video: 200 Area Asbestos Removal, U-Ancillary Demolition, 200 West Transfer Building Footings

ScienceCinema

None

2018-05-23

A weekly update of the Recovery Act at work. Demolition of U-Ancillary that was contaminated with uranium and asbestos as well as removing asbestos from the Steam Generation Plant in the 200 East Area.

Uranium: A Dentist's perspective

PubMed Central

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

2012-01-01

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

Uranium-bearing breccia pipes of northwestern Arizona - an overview

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

Chenoweth, W.L.

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/sub 3/O/sub 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 pipesmore » 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/sub 3/O/sub 8/), the high grade (60 to 70% U/sub 3/O/sub 8/) of the deposits makes the pipes attractive exploration targets.« less

METHOD FOR MAKING FUEL ELEMENTS

DOEpatents

Kates, L.W.; Campbell, R.W.; Heartel, R.H.W.

1960-08-01

A method is given for making zirconium-clad uranium wire. A tube of zirconium is closed with a zirconium plug, after which a chilled uranium core is inserted in the tube to rest against the plug. Additional plugs and cores are inserted alternately as desired. The assembly is then sheathed with iron, hot worked to the desired size, and the iron sheath removed.

XANES and EXAFS investigation of uranium incorporation on nZVI in the presence of phosphate.

PubMed

Qiu, Muqing; Wang, Min; Zhao, Qingzhou; Hu, Baowei; Zhu, Yuling

2018-06-01

Effect of phosphate on the reduction of U(VI) on nZVI was determined by batch, XPS, XANES and EXAFS techniques. The batch experiments showed that nZVI was quite effective for the removal of uranium under the anaerobic conditions, whereas the addition of phosphate enhanced uranium removal over wide pH range. At low pH, the reduction of U(VI) to U(IV) significantly decreased with increasing phosphate concentration by XPS and XANES analysis. According to EXAFS analysis, the occurrence of UU shell at 10 mg/L phosphate and pH 4.0 was similar to that of U (IV) O 2 (s), whereas the UP and UFe shells were observed at 50 mg/L phosphate, revealing that reductive co-precipitate (U (IV) O 2 (s)) and precipitation of uranyl-phosphate were observed at low and high phosphate, respectively. The findings are crucial for the prediction of the effect of phosphate on the speciation and binding of uranium by nZVI at low pH, which is significant in controlling the mobility of U(VI) in contaminated environments. Copyright © 2018 Elsevier Ltd. All rights reserved.

RECOVERY OF THORIUM AND URANIUM VALUES FROM AQUEOUS SOLUTIONS

DOEpatents

Calkins, G.D.

1958-02-18

This patent deals with the separation and recovery of uranium from monazite sand. After initial treatment of the sand with sodium hydroxide, a precipitate is obtuined which contains the uranium, thorium, rare earths and some phosphorus. This precipitate is then dissolved in nitric acid. The bulk of the rare earths are removed from thls soiution by adding aa excess of alkali carbonate, causing precipitation of the rare earths together with part of the thorium present. The solution still contains a considerable amount of thorium, some rare earths, and practically all of the uranium originally present. Thorium and rare earth values are readily precipitated from such solution, and the uranium values thus isolated, by the addition of an excess hydrogen peroxide. The pH value of the solution is preferably adjusted to at least 9 prior to the addition of the peroxide.

Physical exploration for uranium during 1951 in the Silver Reef district, Washington County, Utah

USGS Publications Warehouse

Stugard, Frederick

1954-01-01

During 1951 a joint exploration program of the most promising uraniferous areas in the Silver Reef district was made by the U.S. Geological Survey and the U.S. atomic Energy Commission. A U.S. Bureau of Mines drill crew, on contract to the Atomic Energy Commission, did 2,450 feet of diamond drilling under the geological supervision of the U.S. Geological Survey. The purpose of the drilling was to delineate broadly the favorable ground for commercial development of the uranium deposits. Ten drill holes were located around Pumpkin Point, which is the northeastern end of Buckeye Reef, to probe for extensions of small ore sheets mined on the Point in fine-grained sandstones of the Chinle formation. Three additional holes were located around Tecumseh Hill to probe for extensions of the small showings of uranium-bearing rocks of Buckeye Reef. Only one trace of uranium mineral was detected in the 13 drill holes by logging of drill cores, gamma-ray logging of the holes, and analysis of many core splits from favorable lithology. Extensive traversing with Geiger counters throughout the district and detailed geologic mapping of areas on Buckeye Reef and on East Reef indicate that the chances of discovering significant uranium deposits in the Silver Reef district are very poor, because of: highly variable lithology, closely faulted structure, and obliteration of the shallow uranium-bearing lenses by silver mining. Most of the available ore in the district was in the Pumpkin Point area and has been mined during 1950 to 1953. No ore reserves can be computed for the district before further development work. The most favorable remaining area in the district is now being explored by the operators with Atomic Energy Commission supervision.

Spatial investigation of some uranium minerals using nuclear microprobe

NASA Astrophysics Data System (ADS)

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

2018-01-01

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

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

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

Black, B.A.

1980-09-01

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

Reports on investigations of uranium anomalies. National Uranium Resource Evaluation

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

Goodknight, C.S.; Burger, J.A.

1982-10-01

During the National Uranium Resource Evaluation (NURE) program, conducted for the US Department of Energy (DOE) by Bendix Field Engineering Corporation (BFEC), radiometric and geochemical surveys and geologic investigations detected anomalies indicative of possible uranium enrichment. Data from the Aerial Radiometric and Magnetic Survey (ARMS) and the Hydrogeochemical and Stream-Sediment Reconnaissance (HSSR), both of which were conducted on a national scale, yielded numerous anomalies that may signal areas favorable for the occurrence of uranium deposits. Results from geologic evaluations of individual 1/sup 0/ x 2/sup 0/ quadrangles for the NURE program also yielded anomalies, which could not be adequately checkedmore » during scheduled field work. Included in this volume are individual reports of field investigations for the following six areas which were shown on the basis of ARMS, HSSR, and (or) geologic data to be anomalous: (1) Hylas zone and northern Richmond basin, Virginia; (2) Sischu Creek area, Alaska; (3) Goodman-Dunbar area, Wisconsin; (4) McCaslin syncline, Wisconsin; (5) Mt. Withington Cauldron, Socorro County, New Mexico; (6) Lake Tecopa, Inyo County, California. Field checks were conducted in each case to verify an indicated anomalous condition and to determine the nature of materials causing the anomaly. The ultimate objective of work is to determine whether favorable conditions exist for the occurrence of uranium deposits in areas that either had not been previously evaluated or were evaluated before data from recent surveys were available. Most field checks were of short duration (2 to 5 days). The work was done by various investigators using different procedures, which accounts for variations in format in their reports. All papers have been abstracted and indexed.« less

Spatial investigation of some uranium minerals using nuclear microprobe

NASA Astrophysics Data System (ADS)

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

2018-06-01

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

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

USGS Publications Warehouse

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

1982-01-01

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

Chemical enhancement of surface deposition

DOEpatents

Patch, Keith D.; Morgan, Dean T.

1997-07-29

A method and apparatus for increasing the deposition of ions onto a surface, such as the adsorption of uranium ions on the detecting surface of a radionuclide detector. The method includes the step of exposing the surface to a complexing agent, such as a phosphate ion solution, which has an affinity for the dissolved species to be deposited on the surface. This provides, for example, enhanced sensitivity of the radionuclide detector.

Characterization of uranium redox state in organic-rich Eocene sediments.

PubMed

Cumberland, Susan A; Etschmann, Barbara; Brugger, Joël; Douglas, Grant; Evans, Katy; Fisher, Louise; Kappen, Peter; Moreau, John W

2018-03-01

The presence of organic matter (OM) has a profound impact on uranium (U) redox cycling, either limiting or promoting the mobility of U via binding, reduction, or complexation. To understand the interactions between OM and U, we characterised U oxidation state and speciation in nine OM-rich sediment cores (18 samples), plus a lignite sample from the Mulga Rock polymetallic deposit in Western Australia. Uranium was unevenly dispersed within the analysed samples with 84% of the total U occurring in samples containing >21 wt % OM. Analyses of U speciation, including x-ray absorption spectroscopy and bicarbonate extractions, revealed that U existed predominately (∼71%) as U(VI), despite the low pH (4.5) and nominally reducing conditions within the sediments. Furthermore, low extractability by water, but high extractability by a bi-carbonate solution, indicated a strong association of U with particulate OM. The unexpectedly high proportion of U(VI) relative to U(IV) within the OM-rich sediments implies that OM itself does not readily reduce U, and the reduction of U is not a requirement for immobilizing uranium in OM-rich deposits. The fact that OM can play a significant role in limiting the mobility and reduction of U(VI) in sediments is important for both U-mining and remediation. Copyright © 2017 Elsevier Ltd. All rights reserved.

Uranophane at Silver Cliff mine, Lusk, Wyoming

USGS Publications Warehouse

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

1954-01-01

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

National Uranium Resource Evaluation: Newcastle Quadrangle, Wyoming and South Dakota

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

Santos, E S; Robinson, K; Geer, K A

1982-09-01

Uranium resources of the Newcastle 1/sup 0/x2/sup 0/ Quadrangle, Wyoming and South Dakota were evaluated to a depth of 1500 m (5000 ft) using available surface and subsurface geologic information. Many of the uranium occurrences reported in the literature and in reports of the US Atomic Energy Commission were located, sampled and described. Areas of anomalous radioactivity, interpreted from an aerial radiometric survey, were outlined. Areas favorable for uranium deposits in the subsurface were evaluated using gamma-ray logs. Based on surface and subsurface data, two areas have been delineated which are underlain by rocks deemed favorable as hosts for uraniummore » deposits. One of these is underlain by rocks that contain fluvial arkosic facies in the Wasatch and Fort Union Formations of Tertiary age; the other is underlain by rocks containing fluvial quartzose sandstone facies of the Inyan Kara Group of Early Cretaceous age. Unfavorable environments characterize all rock units of Tertiary age above the Wasatch Formation, all rock units of Cretaceous age above the Inyan Kara Group, and most rock units of Mesozoic and Paleozoic age below the Inyan Kara Group. Unfavorable environments characterize all rock units of Cretaceous age above the Inyan Kara Group, and all rock units of Mesozoic and Paleozoic age below the Inyan Kara Group.« less

Biological pathways of exposure and ecotoxicity values for uranium and associated radionuclides: Chapter D in Hydrological, geological, and biological site characterization of breccia pipe uranium deposits in Northern Arizona

USGS Publications Warehouse

Hinck, Jo E.; Linder, Greg L.; Finger, Susan E.; Little, Edward E.; Tillitt, Donald E.; Kuhne, Wendy

2010-01-01

This chapter compiles available chemical and radiation toxicity information for plants and animals from the scientific literature on naturally occurring uranium and associated radionuclides. Specifically, chemical and radiation hazards associated with radionuclides in the uranium decay series including uranium, thallium, thorium, bismuth, radium, radon, protactinium, polonium, actinium, and francium were the focus of the literature compilation. In addition, exposure pathways and a food web specific to the segregation areas were developed. Major biological exposure pathways considered were ingestion, inhalation, absorption, and bioaccumulation, and biota categories included microbes, invertebrates, plants, fishes, amphibians, reptiles, birds, and mammals. These data were developed for incorporation into a risk assessment to be conducted as part of an environmental impact statement for the Bureau of Land Management, which would identify representative plants and animals and their relative sensitivities to exposure of uranium and associated radionuclides. This chapter provides pertinent information to aid in the development of such an ecological risk assessment but does not estimate or derive guidance thresholds for radionuclides associated with uranium. Previous studies have not attempted to quantify the risks to biota caused directly by the chemical or radiation releases at uranium mining sites, although some information is available for uranium mill tailings and uranium mine closure activities. Research into the biological impacts of uranium exposure is strongly biased towards human health and exposure related to enriched or depleted uranium associated with the nuclear energy industry rather than naturally occurring uranium associated with uranium mining. Nevertheless, studies have reported that uranium and other radionuclides can affect the survival, growth, and reproduction of plants and animals. Exposure to chemical and radiation hazards is influenced by a plant’s or an animal’s life history and surrounding environment. Various species of plants, invertebrates, fishes, amphibians, reptiles, birds, and mammals found in the segregation areas that are considered species of concern by State and Federal agencies were included in the development of the site-specific food web. The utilization of subterranean habitats (burrows in uranium-rich areas, burrows in waste rock piles or reclaimed mining areas, mine tunnels) in the seasonally variable but consistently hot, arid environment is of particular concern in the segregation areas. Certain species of reptiles, amphibians, birds, and mammals in the segregation areas spend significant amounts of time in burrows where they can inhale or ingest uranium and other radionuclides through digging, eating, preening, and hibernating. Herbivores may also be exposed though the ingestion of radionuclides that have been aerially deposited on vegetation. Measured tissues concentrations of uranium and other radionuclides are not available for any species of concern in the segregation areas. The sensitivity of these animals to uranium exposure is unknown based on the existing scientific literature, and species-specific uranium presumptive effects levels were only available for two endangered fish species known to inhabit the segregation areas. Overall, the chemical toxicity data available for biological receptors of concern were limited, although chemical and radiation toxicity guidance values are available from several sources. However, caution should be used when directly applying these values to northern Arizona given the unique habitat and life history strategies of biological receptors in the segregation areas and the fact that some guidance values are based on models rather than empirical (laboratory or field) data. No chemical toxicity information based on empirical data is available for reptiles, birds, or wild mammals; therefore, the risks associated with uranium and other radionuclides are unknown for these biota.

Mechanisms of uranium interactions with hydroxyapatite: Implications for groundwater remediation

USGS Publications Warehouse

Fuller, C.C.; Bargar, J.R.; Davis, J.A.; Piana, M.J.

2002-01-01

The speciation of U(VI) sorbed to synthetic hydroxyapatite was investigated using a combination of U LIII-edge XAS, synchrotron XRD, batch uptake measurements, and SEM-EDS. The mechanisms of U(VI) removal by apatite were determined in order to evaluate the feasibility of apatitebased in-situ permeable reactive barriers (PRBs). In batch U(VI) uptake experiments with synthetic hydroxyapatite (HA), near complete removal of dissolved uranium (>99.5%) to <0.05 ??M was observed over a range of total U(VI) concentrations up to equimolar of the total P in the suspension. XRD and XAS analyses of U(VI)-reacted HA at sorbed concentrations ???4700 ppm U(VI) suggested that uranium(VI) phosphate, hydroxide, and carbonate solids were not present at these concentrations. Fits to EXAFS spectra indicate the presence of Ca neighbors at 3.81 A??. U-Ca separation, suggesting that U(VI) adsorbs to the HA surfaces as an inner-sphere complex. Uranium(VI) phosphate solid phases were not detected in HA with 4700 ppm sorbed U(VI) by backscatter SEM or EDS, in agreement with the surface complexation process. In contrast, U(VI) speciation in samples that exceeded 7000 ppm sorbed U(VI) included a crystalline uranium(VI) phosphate solid phase, identified as chernikovite by XRD. At these higher concentrations, a secondary, uranium(VI) phosphate solid was detected by SEM-EDS, consistent with chernikovite precipitation. Autunite formation occurred at total U:P molar ratios ???0.2. Our findings provide a basis for evaluating U(VI) sorption mechanisms by commercially available natural apatites for use in development of PRBs for groundwater U(VI) remediation.

Uranium Sequestration During Biostimulated Reduction and In Response to the Return of Oxic Conditions In Shallow Aquifers

USGS Publications Warehouse

Fuller, Christopher C.; Johnson, Kelly J.; Akstin, Katherine; Singer, David M.; Yabusaki, Steven B.; Fang, Yilin; Fuhrmann, M.

2015-01-01

A proposed approach for groundwater remediation of uranium contamination is to generate reducing conditions by stimulating the growth of microbial populations through injection of electron donor compounds into the subsurface. Sufficiently reducing conditions will result in reduction of soluble hexavalent uranium, U(VI), and precipitation of the less soluble +4 oxidation state uranium, U(IV). This process is termed biostimulated reduction. A key issue in the remediation of uranium (U) contamination in aquifers by biostimulated reduction is the long term stability of the sequestered uranium. Three flow-through column experiments using aquifer sediment were used to evaluate the remobilization of bioreduced U sequestered under conditions in which biostimulation extended well into sulfate reduction to enhance precipitation of reduced sulfur phases such as iron sulfides. One column received added ferrous iron, Fe(II), increasing production of iron sulfides, to test their effect on remobilization of the sequestered uranium, either by serving as a redox buffer by competing for dissolved oxygen, or by armoring the reduced uranium. During biostimulation of the ambient microbial population with acetate, dissolved uranium was lowered by a factor of 2.5 or more with continued removal for over 110 days of biostimulation, well after the onset of sulfate reduction at ~30 days. Sequestered uranium was essentially all U(IV) resulting from the formation of nano-particulate uraninite that coated sediment grains to a thickness of a few 10’s of microns, sometimes in association with S and Fe. A multicomponent biogeochemical reactive transport model simulation of column effluents during biostimulation was generally able to describe the acetate oxidation, iron, sulfate, and uranium reduction for all three columns using parameters derived from simulations of field scale biostimulation experiments. Columns were eluted with artificial groundwater at equilibrium with atmospheric oxygen to simulate the upper limit of dissolved oxygen in recharge water. Overall about 9% of total uranium removed from solution during biostimulation was remobilized. Release of U during oxic elution was a continuous process over 140 days with dissolved uranium concentrations about 0.2 and 0.8 aM for columns with and without ferrous iron addition, respectively. Uranium remaining on the sediment was in the reduced form. The prolonged period of biostimulation and concomitant sulfate reduction appears to limit the rate of U(IV) oxidative remobilization in contrast to a large release observed for columns in previous studies that did not undergo sulfate reduction. Although continued sulfate reduction may cause decreased permeability from precipitation of iron sulfide, the greater apparent stability of the sequestered U(IV) provided by the sustained biostimulation should be considered in design of field scale remediation efforts. Remobilization of uranium following biostimulated reduction should be tested further at the field scale.

U/Th dating of carbonate deposits from Constantina (Sevilla), Spain.

PubMed

Alcaraz-Pelegrina, J M; Martínez-Aguirre, A

2007-07-01

Uranium-series method has been applied to continental carbonate deposits from Constantina, Seville, in Spain. All samples analysed were impure carbonates and the leachate-leachate method was used to obtain activity ratios in carbonate fraction. Leachate-residue methods were applied to one of the samples in order to compare with leachate-leachate method, but leachate-residue method assumptions did not meet and ages resulting from leachate-residue methods were not valid. Ages obtained by leachate-leachate method range from 1.8 to 23.5ky BP and are consistent with stratigraphical positions of samples analysed. Initial activity ratios for uranium isotopes are practically constant in this period, thus indicating that no changes in environmental conditions occur between 1.8 and 23.5ky period.

The estuarine chemistry and isotope systematics of 234,238U in the Amazon and Fly Rivers

USGS Publications Warehouse

Swarzenski, P.; Campbell, P.; Porcelli, D.; McKee, B.

2004-01-01

Natural concentrations of 238U and ??234U values were determined in estuarine surface waters and pore waters of the Amazon and Fly (Papua New Guinea) Rivers to investigate U transport phenomena across river-dominated land-sea margins. Discharge from large, tropical rivers is a major source of dissolved and solid materials transported to the oceans, and are important in defining not only oceanic mass budgets, but also terrestrial weathering rates. On the Amazon shelf, salinity-property plots of dissolved organic carbon, pH and total suspended matter revealed two vastly contrasting water masses that were energetically mixed. In this mixing zone, the distribution of uranium was highly non-conservative and exhibited extensive removal from the water column. Uranium removal was most pronounced within a salinity range of 0-16.6, and likely the result of scavenging and flocculation reactions with inorganic (i.e., Fe/Mn oxides) and organic colloids/particles. Removal of uranium may also be closely coupled to exchange and resuspension processes at the sediment/water interface. An inner-shelf pore water profile indicated the following diagenetic processes: extensive (???1 m) zones of Fe(III) - and, to a lesser degree, Mn(IV) - reduction in the absence of significant S(II) concentrations appeared to facilitate the formation of various authigenic minerals (e.g., siderite, rhodocrosite and uraninite). The pore water dissolved 238U profile co-varied closely with Mn(II). Isotopic variations as evidenced in ??234U pore waters values from this site revealed information on the origin and history of particulate uranium. Only after a depth of about 1 m did the ??234U value approach unity (secular equilibrium), denoting a residual lattice bound uranium complex that is likely an upper-drainage basin weathering product. This suggests that the enriched ??234U values represent a riverine surface complexation product that is actively involved in Mn-Fe diagenetic cycles and surface complexation reactions. In the Fly River estuary, 238U appears to exhibit a reasonably conservative distribution as a function of salinity. The absence of observed U removal does not necessarily imply non-reactivity, but instead may record an integration of concurrent U removal and release processes. There is not a linear correlation between ??234U vs. 1/ 238U that would imply simple two component mixing. It is likely that resuspension of bottom sediments, prolonged residence times in the lower reaches of the Fly River, and energetic particle-colloid interactions contribute to the observed estuarine U distribution. The supply of uranium discharged from humid, tropical river systems to the sea appears to be foremost influenced by particle/water interactions that are ultimately governed by the particular physiographic and hydrologic characteristics of an estuary. ?? 2004 Elsevier Ltd. All rights reserved.

Geology and ore deposits of the Section 23 Mine, Ambrosia Lake District, New Mexico

USGS Publications Warehouse

Granger, H.C.; Santos, E.S.

1982-01-01

The section 23 mine is one of about 18 large uranium mines opened in sandstones of the fluvial Westwater Canyon Member of the Jurassic Morrison Formation in the Ambrosia Lake mining district during the early 1960s. The Ambrosia Lake district is one of several mining districts within the Grants mineral belt, an elongate zone containing many uranium deposits along the southern flank of the San Juan basin. Two distinct types of ore occur in the mine. Primary ore occurs as peneconcordant layers of uranium-rich authigenic organic matter that impregnates parts of the reduced sandstone host rocks and which are typically elongate in an east-southeast direction subparallel both to the sedimentary trends and to the present-day regional strike of the strata. These are called prefault or trend ores because of their early genesis and their elongation and alinement. A second type of ore in the mine is referred to as postfault, stacked, or redistributed ore. Its genesis was similar to that of the roll-type deposits in Tertiary rocks of Wyoming and Texas. Oxidation, related to the development of a large tongue of oxidized rock extending from Gallup to Ambrosia Lake, destroyed much of the primary ore and redistributed it as massive accumulations of lower grade ores bordering the redox interface at the edge of the tongue. Host rocks in the southern half of sec. 23 (T. 14 N., R. 10 W.) are oxidized and contain only remnants of the original, tabular, organic-rich ore. Thick bodies of roll-type ore are distributed along the leading edge of the oxidized zone, and pristine primary ore is found only near the north edge of the section. Organic matter in the primary ore was derived from humic acids that precipitated in the pores of the sandstones and fixed uranium as both coffinite and urano-organic compounds. Vanadium, molybdenum, and selenium are also associated with the ore. The secondary or roll-type ores are essentially free of organic carbon and contain uranium both as coffinite and uraninite. They also contain vanadium and selenium but are virtually devoid of molybdenum. Although much has been learned about these deposits since the time this study was conducted, in 1966, a great deal more study will by required to completely elucidate their geologic history.

PROCESSING OF MONAZITE SAND

DOEpatents

Calkins, G.D.; Bohlmann, E.G.

1957-12-01

A process for the recovery of thorium, uranium, and rare earths from monazite sands is presented. The sands are first digested and dissolved in concentrated NaOH, and the solution is then diluted causing precipitation of uranium, thorium and rare earth hydroxides. The precipitate is collected and dissolved in HCl, and the pH of this solution is adjusted to about 6, precipitating the hydroxides of thorium and uranium but leaving the rare earths in solution. The rare earths are then separated from the solution by precipitation at a still higher pH. The thorium and uranium containing precipitate is redissolved in HNO/sub 3/ and the two elements are separated by extraction into tributyl phosphate and back extraction with a weakly acidic solution to remove the thorium.

FY-15 Progress Report on Cleanup of irradiated SHINE Target Solutions Containing 140g-U/L Uranyl Sulfate

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

Bennett, Megan E.; Bowers, Delbert L.; Vandegrift, George F.

2015-09-01

During FY 2012 and 2013, a process was developed to convert the SHINE Target Solution (STS) of irradiated uranyl sulfate (140 g U/L) to uranyl nitrate. This process is necessary so that the uranium solution can be processed by the UREX (Uranium Extraction) separation process, which will remove impurities from the uranium so that it can be recycled. The uranyl sulfate solution must contain <0.02 M SO 4 2- so that the uranium will be extractable into the UREXsolvent. In addition, it is desired that the barium content be below 0.0007 M, as this is the limit in the Resourcemore » Conservation and Recovery Act (RCRA).« less

SEPARATION OF URANIUM FROM THORIUM AND PROTACTINIUM

DOEpatents

Musgrave, W.K.R.

1959-06-30

This patent relates to the separation of uranium from thorium and protactinium; such mixtures of elements usually being obtained by neutron irradiation of thorium. The method of separating the constituents has been first to dissolve the mixture of elements in concertrated nitric acid and then to remove the protactinium by absorption on manganese dioxide and the uranium by solvent extraction with ether. Prior to now, comparatively large amounts of thorium were extracted with the uranium. According to the invention this is completely prevented by adding sodium diethyldithiocarbamate to the mixture of soluble nitrate salts. The organic salt has the effect of reacting only with the uranyl nitrate to form the corresponding uranyl salt which can then be selectively extracted from the mixture with amyl acetate.

Simultaneous determination of the quantity and isotopic ratios of uranium in individual micro-particles by isotope dilution thermal ionization mass spectrometry (ID-TIMS).

PubMed

Park, Jong-Ho; Choi, Eun-Ju

2016-11-01

A method to determine the quantity and isotopic ratios of uranium in individual micro-particles simultaneously by isotope dilution thermal ionization mass spectrometry (ID-TIMS) has been developed. This method consists of sequential sample and spike loading, ID-TIMS for isotopic measurement, and application of a series of mathematical procedures to remove the contribution of uranium in the spike. The homogeneity of evaporation and ionization of uranium content was confirmed by the consistent ratio of n((233)U)/n((238)U) determined by TIMS measurements. Verification of the method was performed using U030 solution droplets and U030 particles. Good agreements of resulting uranium quantity, n((235)U)/n((238)U), and n((236)U)/n((238)U) with the estimated or certified values showed the validity of this newly developed method for particle analysis when simultaneous determination of the quantity and isotopic ratios of uranium is required. Copyright © 2016 Elsevier B.V. All rights reserved.

SOLVENT EXTRACTION PROCESS FOR THE SEPARATION OF URANIUM AND THORIUM FROM PROTACTINIUM AND FISSION PRODUCTS

DOEpatents

Rainey, R.H.; Moore, J.G.

1962-08-14

A liquid-liquid extraction process was developed for recovering thorium and uranium values from a neutron irradiated thorium composition. They are separated from a solvent extraction system comprising a first end extraction stage for introducing an aqueous feed containing thorium and uranium into the system consisting of a plurality of intermediate extractiorr stages and a second end extractron stage for introducing an aqueous immiscible selective organic solvent for thorium and uranium in countercurrent contact therein with the aqueous feed. A nitrate iondeficient aqueous feed solution containing thorium and uranium was introduced into the first end extraction stage in countercurrent contact with the organic solvent entering the system from the second end extraction stage while intro ducing an aqueous solution of salting nitric acid into any one of the intermediate extraction stages of the system. The resultant thorium and uranium-laden organic solvent was removed at a point preceding the first end extraction stage of the system. (AEC)

Helium interactions with alumina formed by atomic layer deposition show potential for mitigating problems with excess helium in spent nuclear fuel

NASA Astrophysics Data System (ADS)

Zhang, Shenli; Yu, Erick; Gates, Sean; Cassata, William S.; Makel, James; Thron, Andrew M.; Bartel, Christopher; Weimer, Alan W.; Faller, Roland; Stroeve, Pieter; Tringe, Joseph W.

2018-02-01

Helium gas accumulation from alpha decay during extended storage of spent fuel has potential to compromise the structural integrity the fuel. Here we report results obtained with surrogate nickel particles which suggest that alumina formed by atomic layer deposition can serve as a low volume-fraction, uniformly-distributed phase for retention of helium generated in fuel particles such as uranium oxide. Thin alumina layers may also form transport paths for helium in the fuel rod, which would otherwise be impermeable. Micron-scale nickel particles, representative of uranium oxide particles in their low helium solubility and compatibility with the alumina synthesis process, were homogeneously coated with alumina approximately 3-20 nm by particle atomic layer deposition (ALD) using a fluidized bed reactor. Particles were then loaded with helium at 800 °C in a tube furnace. Subsequent helium spectroscopy measurements showed that the alumina phase, or more likely a related nickel/alumina interface structure, retains helium at a density of at least 1017 atoms/cm3. High resolution transmission electron microscopy revealed that the thermal treatment increased the alumina thickness and generated additional porosity. Results from Monte Carlo simulations on amorphous alumina predict the helium retention concentration at room temperature could reach 1021 atoms/cm3 at 400 MPa, a pressure predicted by others to be developed in uranium oxide without an alumina secondary phase. This concentration is sufficient to eliminate bubble formation in the nuclear fuel for long-term storage scenarios, for example. Measurements by others of the diffusion coefficient in polycrystalline alumina indicate values several orders of magnitude higher than in uranium oxide, which then can also allow for helium transport out of the spent fuel.

National Uranium Resource Evaluation: Lewistown Quadrangle, Montana

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

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/sub 3/O/sub 8/ were delineated. Themore » 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.« less

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

NASA Astrophysics Data System (ADS)

Sharma, S. P.; Biswas, A.

2012-12-01

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

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

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

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

1980-06-01

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

TREATMENT OF URANIUM SURFACES

DOEpatents

Slunder, C.J.

1959-02-01

An improved process is presented for prcparation of uranium surfaces prior to electroplating. The surfacc of the uranium to be electroplated is anodized in a bath comprising a solution of approximately 20 to 602 by weight of phosphoric acid which contains about 20 cc per liter of concentrated hydrochloric acid. Anodization is carried out for approximately 20 minutes at a current density of about 0.5 amperes per square inch at a temperature of about 35 to 45 C. The oxidic film produced by anodization is removed by dipping in strong nitric acid, followed by rinsing with water just prior to electroplating.

Investigations into Alternative Desorption Agents for Amidoxime-Based Polymeric Uranium Adsorbents

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

Gill, Gary A.; Kuo, Li-Jung; Strivens, Jonathan E.

2015-06-01

Amidoxime-based polymeric braid adsorbents that can extract uranium (U) from seawater are being developed to provide a sustainable supply of fuel for nuclear reactors. A critical step in the development of the technology is to develop elution procedures to selectively remove U from the adsorbents and to do so in a manner that allows the adsorbent material to be reused. This study investigates use of high concentrations of bicarbonate along with targeted chelating agents as an alternative means to the mild acid elution procedures currently in use for selectively eluting uranium from amidoxime-based polymeric adsorbents.

Microbial biogeochemistry of uranium mill tailings

USGS Publications Warehouse

Landa, Edward R.

2005-01-01

Uranium mill tailings (UMT) are the crushed ore residues from the extraction of uranium (U) from ores. Among the radioactive wastes associated with the nuclear fuel cycle, UMT are unique in terms of their volume and their limited isolation from the surficial environment. For this latter reason, their management and long-term fate has many interfaces with environmental microbial communities and processes. The interactions of microorganisms with UMT have been shown to be diverse and with significant consequences for radionuclide mobility and bioremediation. These radionuclides are associated with the U-decay series. The addition of organic carbon and phosphate is required to initiate the reduction of the U present in the groundwater down gradient of the mills. Investigations on sediment and water from the U-contaminated aquifer, indicates that the addition of a carbon source stimulates the rate of U removal by microbial reduction. Moreover, most attention with respect to passive or engineered removal of U from groundwaters focuses on iron-reducing and sulfate-reducing bacteria.

Chemical enhancement of surface deposition

DOEpatents

Patch, K.D.; Morgan, D.T.

1997-07-29

A method and apparatus are disclosed for increasing the deposition of ions onto a surface, such as the adsorption of uranium ions on the detecting surface of a radionuclide detector. The method includes the step of exposing the surface to a complexing agent, such as a phosphate ion solution, which has an affinity for the dissolved species to be deposited on the surface. This provides, for example, enhanced sensitivity of the radionuclide detector. 16 figs.

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

PubMed

Sklodowska, Aleksandra; Mielnicki, Sebastian; Drewniak, Lukasz

2018-03-01

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

Uranium-bearing lignite and its relation to the White River and Arikaree formations in northwestern South Dakota and adjacent states

USGS Publications Warehouse

Denson, N.M.; Bachman, G.O.; Zeller, H.D.

1954-01-01

the original White River and Arikaree sediments. Individual maps showing the extent, thickness, and variations in mineral content of the important deposits in the Table Mountain, Cave Hills, Slim Buttes, Lodgepole, and Medicine Pole areas are included. Conditions controlling the concentration of uranium are described and their application as guides to finding additional reserves by the presently held concepts are explained and illustrated.

Irradiation test of tungsten clad uranium carbide-zirconium carbide ((U,Zr)C) specimens for thermionic reactor application at conditions conductive to long-term performance

NASA Technical Reports Server (NTRS)

Creagh, J. W. R.; Smith, J. R.

1973-01-01

Uranium carbide fueled, thermionic emitter configurations were encapsulated and irradiated. One capsule contained a specimen clad with fluoride derived chemically vapor deposited (CVD) tungsten. The other capsule used a duplex clad specimen consisting of chloride derived on floride derived CVD tungsten. Both fuel pins were 16 millimeters in diameter and contained a 45.7-millimeter length of fuel.

The United States’ National Interests in Central Asia

DTIC Science & Technology

2000-03-23

Street Journal, 16 September 1997. 49 Ibid. 50 McHugh , Jane; Elfers, Steve. “Showtime for Sergeants.” Army Times, Vol 59, Issue 17 (23 November...petroleum, coal, manganese,chrome cant deposits of gold some petroleum, coal, sulfur, gold, uranium, ore, nickel , cobalt, and rare earth metals; uranium...Management Review, April 1999. McHugh , Jane; Elfers, Steve. “Showtime for Sergeants.” Army Times, Vol 59, Issue 17 (23 November 1998. Mikhailov

Radioactive mineral springs in Delta County, Colorado

USGS Publications Warehouse

Cadigan, Robert A.; Rosholt, John N.; Felmlee, J. Karen

1976-01-01

The system of springs in Delta County, Colo., contains geochemical clues to the nature and location of buried uranium-mineralized rock. The springs, which occur along the Gunnison River and a principal tributary between Delta and Paonia, are regarded as evidence of a still-functioning hydrothermal system. Associated with the springs are hydrogen sulfide and sulfur dioxide gas seeps, carbon dioxide gas-powered geysers, thick travertine deposits including radioactive travertine, and a flowing warm-water (41?C) radioactive well. Geochemical study of the springs is based on surface observations, on-site water-property measurements, and sampling of water, travertine, soft precipitates, and mud. The spring deposits are mostly carbonates, sulfates, sulfides, and chlorides that locally contain notable amounts of some elements, such as arsenic, barium, lithium, and radium. Samples from five localities have somewhat different trace element assemblages even though they are related to the same hydrothermal system. All the spring waters but one are dominated by sodium chloride or sodium bicarbonate. The exception is an acid sulfate water with a pH of 2.9, which contains high concentrations of aluminum and iron. Most of the detectable radioactivity is due to the presence of radium-226, a uranium daughter product, but at least one spring precipitate contains abundant radium-228, a thorium daughter product. The 5:1 ratio of radium-228 to radium-226 suggests the proximity of a vein-type deposit as a source for the radium. The proposed locus of a thorium-uranium mineral deposit is believed to lie in the vicinity of Paonia, Colo. Exact direction and depth are not determinable from data now available.

Investigations for the Recycle of Pyroprocessed Uranium

NASA Astrophysics Data System (ADS)

Westphal, B. R.; Price, J. C.; Chambers, E. E.; Patterson, M. N.

Given the renewed interest in uranium from the pyroprocessing of used nuclear fuel in a molten salt system, the two biggest hurdles for marketing the uranium are radiation levels and transuranic content. A radiation level as low as possible is desired so that handling operations can be performed directly with the uranium. The transuranic content of the uranium will affect the subsequent waste streams generated and, thus also should be minimized. Although the pyroprocessing technology was originally developed without regard to radiation and transuranic levels, adaptations to the process have been considered. Process conditions have been varied during the distillation and casting cycles of the process with increasing temperature showing the largest effect on the reduction of radiation levels. Transuranic levels can be reduced significantly by incorporating a pre-step in the salt distillation operation to remove a majority of the salt prior to distillation.

Bicarbonate Elution of Uranium from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

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

Pan, Horng-Bin; Wai, Chien M.; Kuo, Li-Jung

Uranium adsorbed on amidoxime-based polyethylene fibers in simulated seawater can be quantitatively eluted using 3 M KHCO3 at 40°C. Thermodynamic calculations are in agreement with the experimental observation that at high bicarbonate concentrations (3 M) uranyl ions bound to amidoxime molecules are converted to uranyl tris-carbonato complex in the aqueous solution. The elution process is basically the reverse reaction of the uranium adsorption process which occurs at a very low bicarbonate concentration (~10-3 M) in seawater. In real seawater experiments, the bicarbonate elution is followed by a NaOH treatment to remove natural organic matter adsorbed on the polymer adsorbent. Usingmore » the sequential bicarbonate and NaOH elution, the adsorbent is reusable after rinsing with deionized water and the recycled adsorbent shows no loss of uranium loading capacity based on real seawater experiments.« less

Bicarbonate Elution of Uranium from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

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

Pan, Horng-Bin; Wai, Chien M.; Kuo, Li-Jung

Uranium adsorbed on amidoxime-based polyethylene fibers in simulated seawater can be quantitatively eluted using 3 M KHCO 3 at 40°C. Thermodynamic calculations are in agreement with the experimental observation that at high bicarbonate concentrations (3 M) uranyl ions bound to amidoxime molecules are converted to uranyl tris-carbonato complex in the aqueous solution. The elution process is basically the reverse reaction of the uranium adsorption process which occurs at a very low bicarbonate concentration (~10 -3 M) in seawater. The bicarbonate elution is followed by a NaOH treatment to remove natural organic matter adsorbed on the polymer adsorbent, in real seawatermore » experiments. Furthermore, by using the sequential bicarbonate and NaOH elution, the adsorbent is reusable after rinsing with deionized water and the recycled adsorbent shows no loss of uranium loading capacity based on real seawater experiments.« less

Bicarbonate Elution of Uranium from Amidoxime-Based Polymer Adsorbents for Sequestering Uranium from Seawater

DOE PAGES

Pan, Horng-Bin; Wai, Chien M.; Kuo, Li-Jung; ...

2017-05-02

Uranium adsorbed on amidoxime-based polyethylene fibers in simulated seawater can be quantitatively eluted using 3 M KHCO 3 at 40°C. Thermodynamic calculations are in agreement with the experimental observation that at high bicarbonate concentrations (3 M) uranyl ions bound to amidoxime molecules are converted to uranyl tris-carbonato complex in the aqueous solution. The elution process is basically the reverse reaction of the uranium adsorption process which occurs at a very low bicarbonate concentration (~10 -3 M) in seawater. The bicarbonate elution is followed by a NaOH treatment to remove natural organic matter adsorbed on the polymer adsorbent, in real seawatermore » experiments. Furthermore, by using the sequential bicarbonate and NaOH elution, the adsorbent is reusable after rinsing with deionized water and the recycled adsorbent shows no loss of uranium loading capacity based on real seawater experiments.« less

CRUCIBLE LINING METHOD

DOEpatents

Bone, W.H.; Schmidt, W.W.

1958-11-01

A method is presented for forming refractory liners in cylindrical reaction vessels used for the reductlon of uranium tetrafluoride to metallic uranium. A preliminary form, having positioning lugs attached thereto, is inserted into the reaction vessel and the refractory powder, usually CaO, is put in the annular space between the form and the inner wall of the reaction vessel. A jolting table is used to compact this charge of liner material ln place, and after thls has been done, the preliminary form is removed and the flnal form or plug is lnserted without disturbing the partially completed lining. The remainder of the lining charge is then introduced and compacted by jolting, after which the form is removed.

Alpha spectrometric characterization of process-related particle size distributions from active particle sampling at the Los Alamos National Laboratory uranium foundry

NASA Astrophysics Data System (ADS)

Plionis, A. A.; Peterson, D. S.; Tandon, L.; LaMont, S. P.

2010-03-01

Uranium particles within the respirable size range pose a significant hazard to the health and safety of workers. Significant differences in the deposition and incorporation patterns of aerosols within the respirable range can be identified and integrated into sophisticated health physics models. Data characterizing the uranium particle size distribution resulting from specific foundry-related processes are needed. Using personal air sampling cascade impactors, particles collected from several foundry processes were sorted by activity median aerodynamic diameter onto various Marple substrates. After an initial gravimetric assessment of each impactor stage, the substrates were analyzed by alpha spectrometry to determine the uranium content of each stage. Alpha spectrometry provides rapid non-distructive isotopic data that can distinguish process uranium from natural sources and the degree of uranium contribution to the total accumulated particle load. In addition, the particle size bins utilized by the impactors provide adequate resolution to determine if a process particle size distribution is: lognormal, bimodal, or trimodal. Data on process uranium particle size values and distributions facilitate the development of more sophisticated and accurate models for internal dosimetry, resulting in an improved understanding of foundry worker health and safety.

Assessment of a Hydroxyapatite Permeable Reactive Barrier to Remediate Uranium at the Old Rifle Site Colorado.

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

Moore, Robert C.; Szecsody, James; Rigali, Mark J.

We have performed an initial evaluation and testing program to assess the effectiveness of a hydroxyapatite (Ca10(PO4)6(OH)2) permeable reactive barrier and source area treatment to decrease uranium mobility at the Department of Energy (DOE) former Old Rifle uranium mill processing site in Rifle, western Colorado. Uranium ore was processed at the site from the 1940s to the 1970s. The mill facilities at the site as well as the uranium mill tailings previously stored there have all been removed. Groundwater in the alluvial aquifer beneath the site still contains elevated concentrations of uranium, and is currently used for field tests tomore » study uranium behavior in groundwater and investigate potential uranium remediation technologies. The technology investigated in this work is based on in situ formation of apatite in sediment to create a subsurface apatite PRB and also for source area treatment. The process is based on injecting a solution containing calcium citrate and sodium into the subsurface for constructing the PRB within the uranium plume. As the indigenous sediment micro-organisms biodegrade the injected citrate, the calcium is released and reacts with the phosphate to form hydroxyapatite (precipitate). This paper reports on proof-of-principle column tests with Old Rifle sediment and synthetic groundwater.« less