WorldWideScience

Sample records for beaverlodge

  1. Uranium deposits in the Beaverlodge area, northern Saskatchewan: their relationship to the Martin Group (Proterozoic) and the underlying basement

    International Nuclear Information System (INIS)

    The rocks of the Martin Group crop out in an area 60 km by 50 km north of Lake Athabasca near Uranium City, northern Saskatchewan. This area has numerous uranium showings within a few kilometres of the unconformity below the Martin Group. Mineralization occurs in fault zones, in basement rocks and in sedimentary and volcanic rocks of the Martin Group. Martin Group sediments accumulated in alluvial fans, braided streams, and ephemeral lakes. The thickest sequence (8 km to 10 km) is preserved in the Beaverlodge area, near Uranium City. The style of sedimentation changed through time as the basin evolved from deposition of conglomeratic detritus along fault scarps to the accumulation of silt in ephemeral lakes. The uneven nature of the sub-Martin unconformity surface, the lithotype of the lowermost conglomerates and breccias (Beaverlodge Formation), and the shape of the basin fill indicate deposition in fault-controlled basins. The earliest economic uranium mineralization in the rocks of the Martin Group was epigenetic. The mineralization was coeval with that in basement rocks. Economic mineralization in basement rocks and in the lowermost formation of the Martin Group is close to the unconformity. Epigenetic uranium mineralization thus appears to have resulted from processes that were related, in time and space, to either the formation of the unconformity or the deposition of the Martin Group or both. (author). 29 refs, 5 figs

  2. Annual report, 1977

    International Nuclear Information System (INIS)

    A financial report for 1977 is presented. Net earnings were $6,933,172. The Beaverlodge operations produced 255,622 tons of ore and 1,184,961 lb. of concentrate. The Port Hope refinery produced 8.5 million lb. of UF6 and 1.8 million lb. of UO2. Sales to Japan and some other countries were held up pending ratification by these countries of the non-proliferation treaty. (LL)

  3. Annual report, 1978

    International Nuclear Information System (INIS)

    A financial report for 1978 is presented. Net earnings were $17,618,000. The Beaverlodge mine produced 307,000 tons of ore, and the mill 1,283,000 lb. of concentrate. The Port Hope refinery produced 1,283,000 lb of UF6 and 2.1 million lb. of U02. The construction of a new UF6 refinery near Port Granby, Ontario was turned down by the federal government on environmental grounds. The search for a new site is continuing. Exploration is underway in seven provinces and two territories; a share in the Key Lake joint venture was acquired. (LL)

  4. Decommissioning of uranium mines and mills - Canadian regulatory approach and experience

    International Nuclear Information System (INIS)

    At the time of the recent closures of the Agnew Lake, Beaverlodge and Madawaska Mines Limited uranium mining and milling facilities, several relevant regulatory initiatives, including the development of decommissioning criteria, were underway, or contemplated. In the absence of precedents, the regulatory agencies and companies involved adopted approaches to the decommissioning of these facilities that reflected site specific circumstances, federal and provincial regulatory requirements, and generally accepted principles of good engineering practice and environmental protection. This paper summarizes related historical and current regulatory policies, requirements and guidelines; including those implemented at the three decommissioned sites

  5. Radioactive ores DH-1, DL-1, BL-2, BL-3, and BL-4

    International Nuclear Information System (INIS)

    The preparation and characterization of a set of six ores of the naturally radioactive elements, for use as certified reference materials in chemical and radiometric analysis, is described. The set consists of two series representing Canada's original uranium-producing areas - Elliot Lake in Ontario and Beaverlodge in Saskatchewan. The Elliot Lake series comprises two samples, one of ore and the other of waste-grade material, both of which contain uranium and thorium. The second series consists of essentially thorium-free material from Beaverlodge, covering the range of 0.02% to 1% U. The former is intended as a reference material for chemical determination of uranium and thorium, while the latter may also be employed in calibrating and verifying radiometric surveying and assaying equipment. In addition to their uranium and thorium contents, supplementary information as to mineralogical composition, state of radioactive equilibrium, and composition with respect to most common and many trace elements of significance in ore processing is given. (author)

  6. Ore reserve calculation methods used by Eldorado Nuclear Limited

    International Nuclear Information System (INIS)

    Uranium-bearing pitchblende deposits of the Beaverlodge area in northern Saskatchewan are highly complex. The ideas and concepts of ore reserve calculation methods employed by Eldorado Nuclear Limited in assessing and planning the mining of these deposits are described. A manual block-system of ore reserve calculation was used before the adoption of the current computerized system. Four classifications are used for ore reserves calculated by the system, which provides two main program jobs for calculating ore reserves and several additional ones that involve calculations and graphical presentation of ore reserve information for use in mine planning. A comparison of production statistics and ore reserve calculations illustrates the accuracy of the method. (author)

  7. Eldorado Nuclear Limited annual report 1979

    International Nuclear Information System (INIS)

    In the fiscal year ending Dec. 31, 1979 Eldorado Nuclear had gross revenues totalling $111 498 000. Net earnings were $398 000. Progress was made towards the completion of capital projects leading to the development of the key Lake deposit and the construction of a new UF6 plant. Studies on a new conversion plant to be located in Saskatchewan are being carried out. Eldorado's mining and processing capacity is to be more than doubled in the early 1980's. The company participated in 28 exploration projects in eight provinces and both territories in 1979. The Beaverlodge mine produced more than 312 000 tons of ore, and 1 006 000 pounds of U3O8 were recovered. Uranium hexafluoride production was 9 890 000 pounds U, and UO2 production accounted for 2 919 000 pounds U. (LL)

  8. Modelling Singhbhum uranium mineralization in the light of Proterozoic uranium metallogeny

    International Nuclear Information System (INIS)

    In mineral deposit modelling, a conceptual or genetic model is preferred to other ones when it is not dogmatic. The characteristics and genesis of major Proterozoic uranium deposits, such as the quartz-pebble conglomerate -type deposits, Franceville deposit, copper belt type deposits, Beaverlodge lake deposits, unconformity - type deposits, the fluidized hematite breccia deposit of Olympic dam, and the albitite - type deposits are discussed. They are grouped into four principal genetic types: (a) palaeoplacer - type, (b) (diagenetic - ) metamorphic - type, (c) the hydrothermal hematitic breccia type, and (d) metasomatic - type. There may be some amount of overprinting of a principal mechanism of ore formation by the features of a later process. In 'a' the original depositional and diagenetic features are still considerably maintained. Type 'b' is generally polygenetic and their genetic history is not always traceable. Type 'c' is hydrothermal, but atypical is being hematite-rich and the nature and origin of the ore fluid and the source of ore-elements in the hydrothermal fluid are far from clear. Albitite - uranium is also an important ore type in the Proterozoic, but far less discussed in the geological literature in English. 'a' and 'b' and 'd' are divisible into sub-types, depending on details. Occurrence along a zone of pronounced ductile (-brittle) shearing close to an Archean-Proterozoic boundary, ore participation in the metamorphic-metasomatic petrography and the ore bodies obeying the L-S structures, confirm an earlier conclusion that the uranium mineralization along the Singhbhum copper-uranium belt belongs to the metamorphic-metasomatic type. It rather belongs to the Beaverlodge lake sub-type. (author). 42 refs., 7 figs

  9. Athabasca basin unconformity-type uranium deposits. A special class of sandstone-type deposits

    International Nuclear Information System (INIS)

    Two major episodes of uranium metallogenesis are recognized in Northern Saskatchewan. The first is of late-Hudsonian age and gave rise to metamorphic-hydrothermal pitchblende deposits of simple mineralogy at Beaverlodge (primary mineralization: 1780+-20 m.y.). The second and more important episode of approximately Grenvillian age rendered unconformity-type deposits in the Athabasca Basin (primary mineralization: 1000-1300 m.y.). The late-Hudsonian deposits at Beaverlodge were overprinted by this second event and new deposits of complex mineralogy were formed in that area. The metallogenetic importance of a third and much later episode which gave rise to mineralization within the Athabasca Formation is uncertain at the moment. With regards to metallogenesis of the unconformity-type deposits, presently available evidence favours a diagenetic-hydrothermal rather than a near-surface supergene or a magmatic/metamorphic hydrothermal model. The diagenetic-hydrothermal model relates uranium mineralization to 'red bed-type' diagenetic processes in the Athabasca Formation involving post-depositional oxidation and leaching, which continued for several hundred million years after deposition. Ore deposits were formed by interaction, under conditions of deep burial at elevated temperatures and pressures, of a uraniferous oxidizing Athabasca aquifer with reducing, graphite-bearing, metamorphic rocks of the basin floor. The large-scale convection required for such interaction may have been induced by mafic magmatic activity coeval with the episode of mineralization. The diagenetic-hydrothermal model displays close similarities with metallogenetic models developed for certain sandstone-type deposits. (author)

  10. Geological characteristics of the main deposits in the world. Geological characteristics of French uranium deposits; their consequences on the different stages of valorisation. The uranium market

    International Nuclear Information System (INIS)

    This document gathers three contributions. In the first one, after having recalled data regarding uranium ore and metal reserves in Canada, USA, South Africa and France, the author describes and discusses the geological and mineral characteristics of the main deposits in Canada (Great Bear Lake, Ace-Verna and other deposits of the Beaverlodge district, Gunnar, Blind River and Bancroft), in the USA (New Mexico, Colorado and Arizona), and in South Africa (similar structure as observed in Blind River). The second contribution addresses the French uranium deposits by firstly presenting, describing and classifying vein deposits (five types are distinguished) and sedimentary deposits in different geological formations, and by secondly discussing the impacts of these characteristics on exploration, surface exploration works, and mining works. The third contribution proposes an overview of the uranium market: comments of world productions (conventional extraction processes and technical peculiarities, costs and prices, reserves and production in Canada, USA, South Africa, France, Australia and others), presentation of the French program (location and production capacity of uranium production plants, locations of ore extraction), overview of the current situation of the world market (price levels, possible prices after 1962), discussion of the comparison between demands and supplies, overview of the French uranium policy

  11. Nature's uncommon elements: Plutonium and technetium

    International Nuclear Information System (INIS)

    The authors have taken advantage of the extremely sensitive method of thermal ionization mass spectrometry to measure technetium and plutonium concentrations in sample masses that are smaller by as much as three orders of magnitude than those used in the early research efforts. The work reported in this paper extends the understanding of the geochemistry of plutonium and technetium by developing detailed descriptions of their associations in well characterized geologic samples, and by using modern neutron-transport modeling tools to better interpret the meaning of the results. Analyses were conducted on samples from three uranium ore deposits selected for their contrasting geochemical environments. The Cigar Lake deposit is an unweathered, unaltered primary ore in a reducing environment which is expected to closely approximate a system that is closed with respect to uranium and its products. The Koongarra deposit is a shallow system, both altered and weathered, subject to active ground water flow. Finally, a sample from the Beaverlodge deposit is included because it is a commercially-available uranium ore standard that allows demonstration of the precision of the analytical results

  12. Alberta Environment's performance measures and indicators - levels 1 and 2 : environmental indicators, behavioural indicators

    International Nuclear Information System (INIS)

    Industries in Alberta are required to monitor ambient air pollution concentrations near their facilities. The Alberta Sustainable Resource Development Department was created in March 2001 to oversee such measures as the air quality index, surface water quality index, reduction of municipal solid waste to landfills, pulp production versus the amount of substance (biochemical oxygen demand), government action on greenhouse gas emissions, and action by Alberta organizations to improve energy efficiency. This paper lists the performance measures for 2000-2001 based on data collected from 9 continuous monitoring stations in Alberta, 3 in Edmonton, 3 in Calgary, 1 in Beaverlodge, 1 in Fort Saskatchewan and 1 in Red Deer. In Edmonton and Calgary, carbon monoxide levels have decreased by more than 60 per cent over the past 2 decades, while nitrogen dioxide levels have decreased by more than 30 per cent over the same time period, and particulate levels have decreased from 40 to 50 per cent since 1986. Benzene levels have also decreased by 30 to 50 per cent over the last decade. For each of the other measures, this paper presented Alberta's goals, the data, the target, results, methodology, external factors, and comparison with other provinces. Responses to frequently asked questions regarding each measure are provided. 14 tabs., 1 fig

  13. Decommissioning: A critical component of the design for uranium tailings management facilities

    International Nuclear Information System (INIS)

    Uranium was discovered in the Beaverlodge area of northern Saskatchewan in 1934 with the first major mill beginning operation in 1953. Little attention was paid to tailings quality or tailings management practices. With the onset of the modern uranium operations beginning in the late 1970's, it was repeatedly evident, that the public had significant concerns, particularly with respect to tailings management, that must be addressed if the developments were to be allowed to proceed. Primary considerations related to environmental protection, public safety and an assurance of the ongoing sustainable development of the region. Integrating the decommissioning of a mine/mill site into development planning from the very outset has proven to be a critical component that has contributed to the ongoing success of the Saskatchewan uranium operations. This paper will provide a case study of the evolution of the uranium tailings management technology utilized in Saskatchewan. It documents the evolution of tailings management processes and the characteristics of tailings produced by successive mines in northern Saskatchewan. It also discusses the evolution of technologies applied to management of uranium mill tailings and demonstrates how progressively increasing levels of environmental protection have been achieved during the last 47 years of uranium mill operation. The paper also shows that the planned and progressive decommissioning of an operational site is the key to: Minimizing environmental impacts; Satisfying public and regulatory concerns; Minimizing operational and decommissioning costs; Minimizing corporate liability; and Shifting public resistance to public support. (author)

  14. Decommissioning: A critical component of the design for uranium tailings management facilities

    International Nuclear Information System (INIS)

    Uranium was discovered in the Beaverlodge area of northern Saskatchewan in 1934 with the first major mill beginning operation in 1953. Little attention was paid to tailings quality or tailings management practices. With the onset of the modem uranium operations beginning in the late 1970's, it was repeatedly evident, that the public had significant concerns, particularly with respect to tailings management, that must be addressed if the developments were to be allowed to proceed. Primary considerations related to environmental protection, public safety and an assurance of the ongoing sustainable development of the region. Integrating the decommissioning of a mine/mill site into development planning from the very outset has proven to be a critical component that has contributed to the ongoing success of the Saskatchewan uranium operations. This paper will provide a case study of the evolution of the uranium tailings management technology utilized in Saskatchewan. It documents the evolution of tailings management processes and the characteristics of tailings produced by successive mines in northern Saskatchewan. It also discusses the evolution of technologies applied to management of uranium mill tailings and demonstrates how progressively increasing levels of environmental protection have been achieved during the last 47 years of uranium mill operation. The paper also shows that the planned and progressive decommissioning of an operational site is the key to: Minimizing environmental impacts; Satisfying public and regulatory concerns; Minimizing operational and decommissioning costs; Minimizing corporate liability; and Shifting public resistance to public support. (author)

  15. Annual report, 1982

    International Nuclear Information System (INIS)

    In 1982 Eldorado Nuclear Ltd. acquired important new sources of uranium in the Wollaston Lake area of northern Saskatchewan by purchasing the shares of Gulf Minerals Canada Ltd. and Uranerz Canada Ltd. Eldorado Nuclear Ltd. is now sole owner of the Rabbit Lake properties, consisting of more than 30 million kg of U3O8 and a mill with a capacity of 2.5 million kg annually. Production records were set at the Port Hope, Ontario, uranium processing plant, and processing capacity continued to expand there and at the new Blind River, Ontario, refinery. The uneconomic Beaverlodge mine in northern Saskatchewan was closed as scheduled. The company participated in the development of the Key Lake project in northern Saskatchewan. This high-grade, open pit mine has reserves containing more than 80 million kg of U3O8, and will have a production capacity of 5.4 million kg annually when production begins in 1983. Company assets were increased from $618.4 million in 1981 to $875.6 million in 1982; and corporate structure was re-organized to integrate newly-acquired operations. Earnings for 1982 were $4 million

  16. Response to inquiry request from the Ludwig, Schilthuis, Boonstra, Wright, Bryzgorni and Johnstone families and Dr. W. O. Scott

    International Nuclear Information System (INIS)

    An EUB inquiry into oil and gas activities in the Hythe and Beaverlodge area in Alberta was requested by a number of families and individuals, living near the area, complaining of emissions from petroleum operations, as well as expressing concerns about increasing community frustration and intentional damage to petroleum facilities. During the Board's consideration of the request two members of the group, Wiebo Ludwig and Richard Boonstra, were charged with criminal offences related to damage to oil and gas facilities in northwestern Alberta. They were tried and convicted for these offences in April 2000. Subsequently, the Board denied the request for an inquiry on the grounds that the oil and gas operations identified by the families have been conducted in compliance with the terms of the respective companies' approvals, licences and permits, and the operations conformed to provincial standards. Furthermore, the families, especially the Ludwig, Boonstra and Schilthuis families, have consistently demonstrated a lack of cooperation over the years in participating in efforts initiated by the Board, industry and government, to find solutions to their concerns. Also, the Board found no objective evidence that the harmful effects identified by the families resulted from the lawful activities of the energy companies operating in the Hythe area. This Memorandum of Decision contains the detailed reasoning of the Board for denying the request for an inquiry, and to provide context, including facts about the extent, scope and performance of oil and gas operations in the area. 2 figs

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

    International Nuclear Information System (INIS)

    Exploration for mineral deposits in Canada resulted in the discovery of large uranium deposits, such as at Great. Bear Lake, Northwest Territories (1930), in the Elliot Lake area, Ontario (1949); Beaverlodge, Wollaston Lake Fold Belt and Carswell Structure in Saskatchewan (1946-1975) and many uranium occurrences in the Canadian Shield, in the Orogenic Belts and in the Platforms. Uranium output in Canada since 1942 until and including 1976 amounted to 112,000 tonnes U. Reasonably Assured uranium resources as of 1976 amounted to 167,000 tonnes U (at a price up to $40/lb. U308) and 15,000 tonnes U (at a price more than $40 up to $60/lb. U3O8). Estimated Additional uranium resources as of 1976 amounted to 392,000 tonnes U (at a price up to $40/lb. U-Og) and 264,000 tonnes U (at a price more than $40 up to $60/lb. U308). Possible further potential beyond the above mentioned classes is tentatively estimated to be in the 6th category according to NEA/IAEA favourability classification. (author)

  18. Surficial origin of North American pitchblende and related uranium deposits

    International Nuclear Information System (INIS)

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

  19. Oxygen and carbon isotopes in ore deposits in sedimentary rocks, ch. 7

    International Nuclear Information System (INIS)

    In this chapter some aspects of the distribution and processes controlling the abundance of 18O and 13C in hydrothermal systems are discussed. The term hydrothermal refers to hot, mineralized fluids which, in this specific case, deposited economic amounts of ore minerals in sedimentary rocks. Such ore minerals contain, only in exceptional cases, significant amounts of oxygen and carbon but both are normally very abundant in the associated gangue minerals: carbonates and silicates. Therefore, most stable isotope investigations which use 18O or 13C are based on the distribution of these isotopes in these gangue minerals and it is evident that the paragenetic relationships between gangue and ore must be fully understood if such data are to yield information about the formation of ore minerals and the origin of fluids and metals. A more detailed discussion concentrates on four genetically different deposits: the Providencia mines in Mexico; the Bluebell Mine in British Columbia (Canada), the Pine Point deposits in the Northwest Territories (Canada), and the Eldorado Mines in the Beaverlodge district in Saskatchewan (Canada)

  20. Uranium mining and exploration are held back in Canada

    International Nuclear Information System (INIS)

    Denison and Rio Algom are nearing the end of expansion programs at their Elliot Lake operations. Denison doubled its throughput to 1500 tonnes/day, and Rio Algom's Quirke and Panel mines produced 350 and 2990 tonnes/day respectively in 1981. The Rabbit Lake mine in Saskatchewan produced 1391 tonnes in 1981. Production at the Cluff Lake mine began in 1980, and the extraction and stockpiling of the 5000 tonne D orebody was completed by Oct. 1981. Key Lake is scheduled to start up in mid-1983 and will have capacity to produce 12 million pounds/yr of U3O8. Ontario Hydro is to buy 5200 tonnes of uranium from Key Lake, a third of its requirements between 1985 and 1993. Madawaska Mines, Agnew Lake Mines, and Eldorado's Beaverlodge mine are closing, startup on the Midwest Lake project is being deferred. Exploration for uranium is centered in Saskatchwan, at Dawn Lake, McClean Lake, and in the Athabasca basin. Activity is also high in the Northwest Territories. Moratoriums on uranium mining and exploration continue in British Columbia and Nova Scotia

  1. The geological survey's contribution to uranium exploration in Canada - A commentary

    International Nuclear Information System (INIS)

    In Canada mineral resource activities are divided between three jurisdictions: The Federal and Provincial governments and the dominantly privately owned mineral and petroleum industry. Management of mineral resources is a provincial government responsibility. Uranium is an exception, as a consequence of special legislation enacted by the Federal Government in 1942 because of the element's unique properties and strategic importance. This enabled the Geological Survey of Canada (GSC), as a Federal agency, to make studies of uranium resources, including assessment and the study of deposits, that were not possible with respect to other mineral commodities. During the 40's GSC participated in early exploration for uranium. In 1951 search for the commodity was opened to private prospectors and this led rapidly to the development of the Beaverlodge, Bancroft and Elliot Lake uranium camps. During this period GSC maintained a watching brief, and undertook research on uranium deposit geology and exploration method development. Exploration method research became particularly active after 1967 with the development of gamma ray spectrometry instruments and methods, and geochemical exploration methods including radon methods. The Uranium Reconnaissance Programme was launched following the 1973/74 oil crisis, and resulted in geochemical surveys mapping the distribution of 8 to 12 elements over 860,000 km2 and gamma ray spectrometer surveys over 1,590,000 km2. Information released in the form of hundreds of maps had stimulated many millions of dollars of exploration activity by industry. The data subsequently proved valuable for other commodities in addition to uranium. GSC provided basic uranium resource information. In addition it encouraged the development of high quality uranium exploration techniques which were subsequently made available to explorationists all over the world through Canada's support of the uranium activities of the IAEA. 15 refs, 4 figs, 1 tab

  2. Uranium geology of the eastern Baker Lake basin, District of Keewatin, Northwest Territories

    International Nuclear Information System (INIS)

    Proterozoic sequences associated with major unconformities are potential uranium metallogenic provinces. Late Aphebian to Paleohelikian Dubawnt Group contintental clastic sedimentary and subaerial alkaline volcanic rocks and underlying Archean gneisses, District of Keewatin, Northwest Territories, represent one such uraniferous metallogenic province. Three types of uranium mineralization are present in the eastern Baker Lake basin, which extends from Christopher Island at the eastern end of Baker Lake southwestwards to the western limit of Thirty Mile Lake. The three uranium associations are: 1) fracture controlled mineralization in the Dubawnt Group and basement gneisses (U-Cu-Ag-Au-Se or U-Cu-Pb-Mo-Zn), 2)diatreme breccia mineralization in basement gneisses (U-Cu-Zn), and 3) impregnation and microfracture mineralization in altered arkose peripheral to lamprophyre dykes(U-Cu-Ag). Hydrothermal fracture related mineralization is controlled by northwest- and east-northeast-trending fault-fracture zones. Diatreme breccia mineralization results from the channelling of groundwaters through highly permeable brecciated gneiss. Mineralization within the altered Kazan arkose peripheral to alkaline dyke complexes formed by a two stage process. Iron and copper sulphides and silver were deposited within the outer portions of the thermal aureole in response to a temperature and Eh gradient across a convective cell created by the thermal anomaly of the dyke complex. The epigenetic sulphide mineralization subsequently provided the reducing environment for precipitation of uranium from groundwater. All three uranium associations show a close spatial distribution to the basal Dubawnt unconformity. The lithological and structural relationships of the Dubawnt Group rocks, types of mineralization and associated alteration assemblages are strikingly similar to the Beaverlodge district, Saskatchewan. (author)

  3. Modeling of U-series Radionuclide Transport Through Soil at Pena Blanca, Chihuahua, Mexico

    Science.gov (United States)

    Pekar, K. E.; Goodell, P. C.; Walton, J. C.; Anthony, E. Y.; Ren, M.

    2007-05-01

    The Nopal I uranium deposit is located at Pena Blanca in Chihuahua, Mexico. Mining of high-grade uranium ore occurred in the early 1980s, with the ore stockpiled nearby. The stockpile was mostly cleared in the 1990s; however, some of the high-grade boulders have remained there, creating localized sources of radioactivity for a period of 25-30 years. This provides a unique opportunity to study radionuclide transport, because the study area did not have any uranium contamination predating the stockpile in the 1980s. One high-grade boulder was selected for study based upon its shape, location, and high activity. The presumed drip-line off of the boulder was marked, samples from the boulder surface were taken, and then the boulder was moved several feet away. Soil samples were taken from directly beneath the boulder, around the drip-line, and down slope. Eight of these samples were collected in a vertical profile directly beneath the boulder. Visible flakes of boulder material were removed from the surficial soil samples, because they would have higher concentrations of U-series radionuclides and cause the activities in the soil samples to be excessively high. The vertical sampling profile used 2-inch thicknesses for each sample. The soil samples were packaged into thin plastic containers to minimize the attenuation and to standardize sample geometry, and then they were analyzed by gamma-ray spectroscopy with a Ge(Li) detector for Th-234, Pa-234, U-234, Th-230, Ra-226, Pb-214, Bi-214, and Pb-210. The raw counts were corrected for self-attenuation and normalized using BL-5, a uranium standard from Beaverlodge, Saskatchewan. BL-5 allowed the counts obtained on the Ge(Li) to be referenced to a known concentration or activity, which was then applied to the soil unknowns for a reliable calculation of their concentrations. Gamma ray spectra of five soil samples from the vertical profile exhibit decreasing activities with increasing depth for the selected radionuclides