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Sample records for ambrosia lake uranium

  1. Environmental Assessment of remedial action at the Ambrosia Lake uranium mill tailings site, Ambrosia Lake, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    1987-06-01

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Ambrosia Lake uranium mill tailings site located near Ambrosia Lake, New Mexico. The designated site covers 196 acres and contains 111 acres of tailings and some of the original mill structures. The Uranium Mill Tailings Radiation Control Act (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated properties off the site. The US Environmental Protection Agency promulgated standards for th remedial action (40 CFR Part 192). Remedial action must be performed in accordance with these standards and with the concurrence of the Nuclear Regulatory Commission. The proposed action is to stabilize the tailings at their present location by consolidating the tailings and associated contaminated materials into a recontoured pile. A radon barrier would be constructed over the pile and various erosion protection measures would be taken to assure the long-term stability of the pile. Another alternative which would involve moving the tailings to a new location is also assessed in this document. This alternative would generally involve greater short-term impacts and costs but would result in stabilization of the tailings at an undeveloped location. The no action alternative is also assessed in this document.

  2. Environmental Assessment of remedial action at the Ambrosia Lake uranium mill tailings site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Ambrosia Lake uranium mill tailings site located near Ambrosia Lake, New Mexico. The designated site covers 196 acres and contains 111 acres of tailings and some of the original mill structures. The Uranium Mill Tailings Radiation Control Act (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated properties off the site. The US Environmental Protection Agency promulgated standards for th remedial action (40 CFR Part 192). Remedial action must be performed in accordance with these standards and with the concurrence of the Nuclear Regulatory Commission. The proposed action is to stabilize the tailings at their present location by consolidating the tailings and associated contaminated materials into a recontoured pile. A radon barrier would be constructed over the pile and various erosion protection measures would be taken to assure the long-term stability of the pile. Another alternative which would involve moving the tailings to a new location is also assessed in this document. This alternative would generally involve greater short-term impacts and costs but would result in stabilization of the tailings at an undeveloped location. The no action alternative is also assessed in this document

  3. Engineering assessment of inactive uranium mill tailings: Phillips/United Nuclear site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Phillips/United Nuclear site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Ambrosia Lake, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from 2.6 million dry tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $21,500,000 for stabilization in-place, to about $45,200,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Phillips/United Nuclear tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing.The cost of the uranium recovered would be about $87/lb of U3O8 by either heap leach or conventional plant process. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Phillips/United Nuclear tailings for uranium recovery does not appear to be economically attractive under present or foreseeable market conditions

  4. Radiological survey of the inactive uranium-mill tailings at Ambrosia Lake, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    Haywood, F.F.; Christian, D.J.; Ellis, B.S.; Hubbard, H.M. Jr.; Lorenzo, D.; Shinpaugh, W.H.

    1980-06-01

    The inactive uranium-mill tailings pile at Ambrosia Lake, New Mexico, contains approximately 1520 Ci of /sup 226/Ra in 2.4 million metric tons of tailings covering an area of 43 hectares. All of the former mill buildings were intact and, at the time of this survey, several were in use. The tailings have not been stabilized, but the crusty surface is reported to be resistant to wind erosion. The average gamma-ray exposure rate 1 m above the tailings is 720 ..mu..R/h while the average rate in the former mill area is 150 ..mu..R/h. The adjacent area, between the mill site, ponds, and tailings pile, has an average exposure rate of 230 ..mu..R/h. Gamma radiation measurements outside these areas, as well as the results of analyses of surface or near-surface sediment and soil samples, show fairly wide dispersion of contamination around the site. The subsurface distribution of /sup 226/Ra in 18 holes drilled at the site, calculated from gamma-ray monitoring data, is presented graphically and compared with measured concentrations in two holes.

  5. Summary of the engineering assessment of inactive uranium mill tailings: Phillips/United Nuclear site, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Phillips/United Nuclear site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Ambrosia Lake, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.6 million dry tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $21,500,000 for stabilization in-place, to about $45,200,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Phillips/United Nuclear tailings were examined: heap leaching; treatment at an existing mill; reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $87/lb of U3O8 by either heap leach or conventional plant process. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Phillips/United Nuclear tailings for uranium recovery does not appear to be economically attractive under present or foreseeable market conditions

  6. Phase II, Title I engineering assessment of inactive uranium mill tailings, Phillips/United Nuclear Site, Ambrosia Lake, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    None

    1977-12-01

    An engineering assessment was performed of the problems resulting from the existence of radioactive uranium mill tailings at the Phillips/United Nuclear site at Ambrosia Lake, New Mexico. Services included the preparation of topographic maps, the performance of core drillings sufficient to determine areas and volumes of tailings, and radiometric measurements to determine radium-contaminated materials, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas release from the 2.6 million tons of tailings at the Phillips/United Nuclear site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The estimated radiological health effects to the general population are considered to be minimal. The two alternative actions presented are: dike stabilization, fencing, and maintenance; and adding 2 ft of stabilization cover material. Both options include remedial action at off-site structures and on-site decontamination around the tailings pile. Cost estimates for the two options are $920,000 and $2,230,000, respectively.

  7. Remedial action plan and site conceptual design for stabilization of the inactive uranium mill tailings site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    This Remedial Action Plan (RAP) has been developed to serve a dual purpose. It presents the series of activities that is proposed by the US Department of Energy (DOE) to stabilize and control radioactive materials at the inactive Phillips/United Nuclear uranium processing site designated as the Ambrosia Lake site in McKinley County, New Mexico. It also serves to document the concurrence of both State of New Mexico and the US Nuclear Regulatory Commission (NRC) in the remedial action. This agreement, upon execution by the DOE and the state and concurrence by NRC, becomes Appendix B of the Cooperative Agreement

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

    Science.gov (United States)

    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

  9. Site observational work plan for the UMTRA Project site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    The Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site is within the Grants Mineral Belt and was one of numerous uranium mills supplied by many local mines. Ground water contamination at the site occurred as a result of uranium mill operations. The potential for impacts to human health and the environment from contaminated ground water currently does not exist. No domestic or livestock wells accessing ground water from the uppermost aquifer have been identified within a 5 mile radius from the site. Therefore, no current exposure pathways to humans, livestock, or wildlife exist, nor are any foreseen. The proposed ground water compliance strategy under consideration for application at the Ambrosia Lake site is to perform no remediation, based on the application of supplemental standards because the ground water has ''limited use.''

  10. Site Observational Work Plan for the UMTRA project site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    Ground water compliance for the Uranium Mill Tailings Remedial Action (UMTRA) Project sites, including the Ambrosia Lake, New Mexico, site, is governed by the Uranium Mills Tailings Radiation Control Act (42 USC section 7901 et seq.) and the U.S. Environmental Protection Agency's Health and Environmental Protection Standards for Uranium and Thorium Mill Tailings (40 CFR Part 192; 60 FR 2854). The EPA standards describe specific conditions for which the U.S. Department of Energy (DOE) may apply for supplemental standards for contaminated ground water rather than meeting background levels or numerical standards. To achieve compliance with Subpart A of the EPA standards the residual radioactive materials are currently being consolidated on the site by the DOE in a disposal cell, isolating them from direct human or ecological contact and further dispersion into the environment. Completion of the disposal cell is scheduled for early 1995. An environmental assessment and a Finding of No Significant Impact (FONSI) were completed in 1987. Concurrence with the UMTRA Surface Project Ambrosia Lake remedial action plan (RAP) was granted by the U.S. Nuclear Regulatory Commission (NRC) and state of New Mexico in 1990. The DOE deferred compliance with Subpart B of the EPA standards in the Surface Project RAP. This site observational work plan (SOWP) is the first document to address ground water compliance under Subpart B at the Ambrosia Lake site. The Ambrosia Lake UMTRA Project site is within the Grants Mineral Belt and was one of numerous uranium mills supplied by many local mines. Ground water contamination at the site occurred as a result of uranium mill operations. Contamination of ground water resulted from discharge of waste water, infiltration of water through the tailings pile, hydraulic placement of mill tailings in nearby mines, and water pumped from mine shafts

  11. Supplement to the UMTRA Project water sampling and analysis plan, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    The Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site is in McKinley County, New Mexico. As part of UMTRA surface remediation, residual radioactive materials were consolidated on the site in a disposal cell that was completed July 1995. The need for ground water monitoring was evaluated and found not to be necessary beyond the completion of the remedial action because the ground water in the uppermost aquifer is classified as limited use

  12. Final audit report of remedial action construction at the UMTRA Project Ambrosia Lake, New Mexico, site

    International Nuclear Information System (INIS)

    The final audit report for remedial action at the Ambrosia Lake, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project site consists of a summary of the radiological surveillances/audits, quality assurance (QA) in-process surveillances, and a QA final closeout inspection performed by the US Department of Energy (DOE) and the Technical Assistance Contractor (TAC). One radiological surveillance and three radiological audits were performed at the Ambrosia Lake site. The surveillance was performed on 12--16 April 1993 (DOE, 1993d). The audits were performed on 26--29 July 1993 (DOE, 1993b); 21--23 March 1994 (DOE, 1994d); and 1--2 August 1994 (DOE, 1994d). The surveillance and audits resulted in 47 observations. Twelve of the observations raised DOE concerns that were resolved on site or through subsequent corrective action. All outstanding issues were satisfactorily closed out on 28 December 1994. The radiological surveillance and audits are discussed in this report. A total of seven QA in-process surveillances were performed at the Ambrosia Lake UMTRA site are discussed. The DOE/TAC Ambrosia Lake final remedial action close-out inspection was conducted on 26 July 1995 (DOE, 1995a). To summarize, a total of 155 observations were noted during DOE/TAC audit and surveillance activities. Follow-up to responses required from the RAC for the DOE/TAC surveillance and audit observations indicated that all issues related to the Ambrosia Lake site were resolved and closed to the satisfaction of the DOE

  13. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-07-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the U.S. Department of Energy`s (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials.

  14. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-11-01

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the US Department of Energy`s (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials.

  15. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the U.S. Department of Energy's (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the U.S. Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials

  16. Long-term surveillance plan for the Ambrosia Lake, New Mexico disposal site

    International Nuclear Information System (INIS)

    This long-term surveillance plan (LTSP) for the Uranium Mill Tailings Remedial Action (UMTRA) Project Ambrosia Lake disposal site in McKinley County, New Mexico, describes the US Department of Energy's (DOE) long-term care program for the disposal site. The DOE will carry out this program to ensure that the disposal cell continues to function as designed. This LTSP was prepared as a requirement for acceptance under the US Nuclear Regulatory Commission (NRC) general license for custody and long-term care of residual radioactive materials

  17. UMTRA project water sampling and analysis plan, Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    This water sampling and analysis plan (WSAP) provides the basis for ground water sampling at the Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site during fiscal year 1994. It identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations and will be updated annually. The Ambrosia Lake site is in McKinley County, New Mexico, about 40 kilometers (km) (25 miles [mi]) north of Grants, New Mexico, and 1.6 km (1 mi) east of New Mexico Highway 509 (Figure 1.1). The town closest to the tailings pile is San Mateo, about 16 km ( 10 mi) southeast (Figure 1.2). The former mill and tailings pile are in Section 28, and two holding ponds are in Section 33, Township 14 North, Range 9 West. The site is shown on the US Geological Survey (USGS) map (USGS, 1980). The site is approximately 2100 meters (m) (7000 feet [ft]) above sea level

  18. UMTRA project water sampling and analysis plan, Ambrosia Lake, New Mexico

    Energy Technology Data Exchange (ETDEWEB)

    1994-02-01

    This water sampling and analysis plan (WSAP) provides the basis for ground water sampling at the Ambrosia Lake Uranium Mill Tailings Remedial Action (UMTRA) Project site during fiscal year 1994. It identifies and justifies the sampling locations, analytical parameters, detection limits, and sampling frequency for the monitoring locations and will be updated annually. The Ambrosia Lake site is in McKinley County, New Mexico, about 40 kilometers (km) (25 miles [mi]) north of Grants, New Mexico, and 1.6 km (1 mi) east of New Mexico Highway 509 (Figure 1.1). The town closest to the tailings pile is San Mateo, about 16 km ( 10 mi) southeast (Figure 1.2). The former mill and tailings pile are in Section 28, and two holding ponds are in Section 33, Township 14 North, Range 9 West. The site is shown on the US Geological Survey (USGS) map (USGS, 1980). The site is approximately 2100 meters (m) (7000 feet [ft]) above sea level.

  19. Geology and ore deposits of the Section 23 mine, Ambrosia Lake District, New Mexico

    International Nuclear Information System (INIS)

    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 uranium district, during the early 1960s. Two distinct types of unoxidized ore occur in the mine. One type consists of uranium-rich authigenic organic matter that impregnates parts of the reduced sandstone host rocks. This type of ore occurs as peneconcordant layers which are typically elongate east-southeast, subparallel both to the sedimentary trends and to the regional strike of the host rock. A second type of ore is essentially devoid of organic matter and occurs in thick zones which conform to interfaces that separate oxidized from reduced parts of the host rocks. Genesis of the second type of ore is similar to that of roll-type deposits in Tertiary rocks of Wyoming and Texas. Organic matter in the primary ores was probably introduced into the host rock as humic acids that precipitated in the pores of the sandstone. This material is inferred first to have fixed uranium as urano-organic compounds but with further diagenesis, to have released some of the uranium to form coffinite. Vanadium, molybdenum, and selenium are associated with primary ore and may also have been fixed by the organic matter. The secondary or roll-type ores contain uranium mostly in the form of coffinite and only rarely as uraninite. They also contain vanadium and selenium but are virtually devoid of molybdenum

  20. Supplement to the site observational work plan for the UMTRA Project Site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    The purpose of this document is to provide additional and more detailed information to supplement review of the site observational work plan (SOWP) for the Ambrosia Lake, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project site. This document includes a discussion of (1) the average linear velocity of the ground water in the alluvium; (2) the ground water quality of the alluvium, weathered Mancos Shale, and the Tres Hermanos-C Member of the Mancos Shale; and (3) the fate and transport of contaminants from the uppermost aquifer to the Westwater Canyon Member of the Morrison Formation. The data from a 1989 aquifer test were analyzed using the curve-matching software AQTESOLV and then compared with the original results. A hydrograph of the ground water elevations in monitoring wells screened in the alluvium is presented to show how the ground water elevations change with time. Stiff and Piper diagrams were created to describe the changes in ground water geochemistry in the alluvium/weathered Mancos Shale unit, the Tres Hermanos-C Sandstone unit, the Tres Hermanos-B Sandstone unit, and the Dakota Sandstone. Background information on other related topics such as site history, cell construction, soil characteristics, and well construction are presented in the SOWP. Figure 1 is a geologic cross section depicting the conceptual model of the hydrostratigraphy and ground water chemistry of the Ambrosia Lake site. Table 1 presents hydrogeologic information of each hydrostratigraphic unit

  1. Supplement to the site observational work plan for the UMTRA project site at Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    The purpose of this document is to provide additional and more detailed information to supplement review of the site observational work plan (SOWP) (DOE, 1995) for the Ambrosia Lake, New Mexico, Uranium Mill Tailings Remedial Action (UMTRA) Project site. This document includes a discussion of the average linear velocity of the ground water in the alluvium and a discussion of the ground water quality of the alluvium, weathered Mancos Shale, and the Tres Hermanos-C Member of the Mancos Shale. The data from a 1989 aquifer test were analyzed using the curve-matching software AQTESOLV and then compared with the original results. A hydrograph of the ground water elevations in monitoring wells screened in the alluvium is presented to show how the ground water elevations change with time. Stiff and Piper diagrams were created to describe the changes in ground water geochemistry in the alluvium/weathered Mancos Sahel unit, the Tres Hermanos-C Sandstone unit, the Tres Hermanos-B Sandstone unit, and the Dakota Sandstone. Background information on other related topics such as site history, cell construction, soil characteristics, and well construction are presented in the SOWP. A geologic cross section depicts the conceptual model of the hydrostratigraphy and ground water chemistry of the Ambrosia Lake site. Hydrogeologic information of each hydrostratigraphic unit is presented

  2. The Ambrosia Lake project archaeological investigations of three small sites associated with the southern Chacoan outlier of Kin Nizhoni, McKinley County, New Mexico

    International Nuclear Information System (INIS)

    During the fall of 1987, Complete Archaeological Service Associates conducted mitigative excavations at three sites (LA50363, LA50364, and LA50371) in McKinley County, New Mexico. These sites are adjacent to the Phillips/United Nuclear Inactive Uranium Mill and Tailings site at Ambrosia Lake, New Mexico. The primary deposition at each of these sites appears to be related to a Pueblo II or Bonito Phase occupation. Temporal placement is based primarily on the cross dating of ceramics and archaeomagnetic determinations when possible. No tree-ring or radiocarbon samples are available from these sites. These Ambrosia Lake sites indicate that this area was occupied primarily by Pueblo II people who may have had close social, economic, and ceremonial ties with the people living at the nuclear community of Lower Nizhoni about 3 km south-southeast. The later component at LA50364 indicates a Pueblo III occupation by people who may have had similar ties to the people of the Kin Nizhoni nuclear community. The Ambrosia Lake sites, then, provide important information on the structure of subnuclear communities within the southern Chaco periphery

  3. Lake Way uranium project

    Energy Technology Data Exchange (ETDEWEB)

    Eskell, S.; French, R.R.

    1982-01-01

    Several years ago Lake Way was considered by many to be too small and too low in grade to compete with the larger high grade deposits in other parts of Australia, and particularly in the Northern Territory. The pendulum has now swung and as far as Australian uranium resources are concerned Lake Way now has many advantages over the larger, richer deposits in other parts of Australia. These advantages are set out under appropriate headings (size, location, aboriginals, operating procedures, shipping, equity, and timing).

  4. Radiological surveillance of Remedial Action activities at the processing site, Ambrosia Lake, New Mexico, April 12--16, 1993. Final report

    International Nuclear Information System (INIS)

    The Uranium Mill Tailings Remedial Action (UMTRA) Project's Technical Assistance Contractor (TAC) performed a radiological surveillance of the Remedial Action Contractor (RAC), MK-Ferguson and CWM Federal Environmental Services, Inc., at the processing site in Ambrosia Lake, New Mexico. The requirements and attributes examined during the audit were developed from reviewing working-level procedures developed by the RAC. Objective evidence, comments, and observations were verified based on investigating procedures, documentation, records located at the site, personal interviews, and tours of the site. No findings were identified during this audit. Ten site-specific observations, three good practice observations, and five programmatic observations are presented in this report. The overall conclusion from the surveillance is that the radiological aspects of the Ambrosia Lake, New Mexico, remedial action program are performed adequately. The results of the good practice observations indicate that the site health physics (HP) staff is taking the initiative to address and resolve potential issues, and implement suggestions useful to the UMTRA Project. However, potential exists for improving designated storage areas for general items, and the RAC Project Office should consider resolving site-specific and procedural inconsistencies

  5. Health implications of radionuclide levels in cattle raised near U mining and milling facilities in Ambrosia Lake, New Mexico

    International Nuclear Information System (INIS)

    This study was conducted to determine radionuclide tissue levels in cattle raised near U mining and milling facilities. Ambrosia Lake, New Mexico, has been the site of extensive U mining for 30 y and contains several underground U mines, a processing mill, and two large U tailings piles. Ten cows were purchased from two grazing areas in Ambrosia Lake and ten control animals were purchased from Crownpoint, New Mexico. Muscle, liver, kidney, and bone tissue taken from these animals, and environmental samples, including water, grasses and soil collected from the animals' grazing areas, were analyzed for 238U, 234U, 230Th, 226Ra, 210Pb, and 210Po. Mean radionuclide levels in cattle tissue and environmental samples from Ambrosia Lake were higher in almost every comparison than those found in respective controls. Liver and kidney tissues were particularly elevated in 226Ra and 210Po. Radiation dose commitments from eating cattle tissue with these radionuclide concentrations were calculated. We concluded that the health risk to the public from eating exposed cattle is minimal, unless large amounts of this tissue, especially liver and kidney, are ingested

  6. Mineralogy and geochemistry of Mariano Lake uranium deposit, Smith Lake district

    International Nuclear Information System (INIS)

    The Mariano Lake uranium deposit is located on the west side of the Smith Lake district in the Grants mineral belt. Mineralization is restricted to a basal arkosic sandstone of the Brushy Basin Member of the Morrison Formation (Upper Jrassic). This sandstone is equivalent to the Poison Canyon sandstone of the Ambrosia Lake district and contains a series of paleochannels that have been mineralized. The ore displays a roll-type geometry and is located at an iron-sulfur redox interface. The deposit is chemically different from other deposits of the grants mineral belt. It is characterized by low total carbon dioxide, calcium, molybdenum, and selenium, whereas sulfur and vanadium are enriched. Arsenic and zinc exhibit regular zoning patterns across the deposit. The deposit contains an ubiquitous assemblage of pyrite, kaolinite, chlorite, illite, and illite-montmorillonite associated with vanadiferous ore mixed with organic carbon. No primary uranium minerals have been identified. Gypsum (variety selenite) is present, but calcite is absent. The age of mineralization is unknown. The ore has been remobilized, perhaps more than once, and mineralization may have occurred during mid-Cretaceous, Laramide, or post-Laramide time. Based on existing data, polygenetic models are as reasonable as a single stage of remobilization

  7. Uranium ore rolls in Westwater Canyon sandstone, San Juan Basin, New Mexico

    International Nuclear Information System (INIS)

    Recent relatively deep uranium-exploration drilling in the Nose Rock area, San Juan Basin, McKinley County, New Mexico, has resulted in the discovery of previously unrecognized uranium ore rolls in gray, unoxidized Westwater Canyon Sandstone of the Morrison Formation. Both the Nose Rock ores and the primary Ambrosia Lake uranium ores were emplaced during the Late Jurassic-Early Cretaceous erosional interval under the same geologic conditions by the same geochemical-cell process. The red, altered interior ground resulting from the geochemical-cell process has been re-reduced by the subsequent entry of reductants into the formation. The original roll form of the Ambrosia Lake orebodies has been obscured and modified by redistribution related to the present-day active redox interface interweaving with the Ambrosia Lake ores

  8. Midwest Lake uranium discovery, Saskatchewan, Canada

    International Nuclear Information System (INIS)

    The discovery of the Midwest Lake uranium deposit in Saskatchewan came some ten years after the start of exploration. The original mining rights were acquired on the basis of regional published, geology and proximity to the earlier discovery. Aerial radiometric surveys led to the location of a train of radioactive, glacially transported sandstone boulders and cobbles. The source of these mineralized erratics did not outcrop, and an extensive series of magnetic, electromagnetic, seismic and gravity surveys was carried out in an unsuccessful attempt to identify the source location. These surveys were followed by several programmes of diamond drilling, geochemical surveys and Pleistocene geological studies. None of these programmes or surveys encountered bedrock mineralization. When information about ore controls in the Athabasca Basin became available, a limited programme of three 300-m wildcat diamond-drill holes was proposed. The second of these holes cut weak radioactivity in a poorly cored intersection. This intersection was at an unconformity at a depth of 200 m. The programme terminated prematurely with early melting of lake ice. The first hole in the subsequent winter's follow-up drilling intersected uranium values in excess of 8%. (author)

  9. Uranium anomalies in deep-water sediments of Lake Baikal

    International Nuclear Information System (INIS)

    On the base of data of the element analysis of the Lake Baikal water and deep-water sediments are investigated the causes of uranium anomalous content in terrigenous pelitic silts. It is established that the anomaly cause is uranium accumulation by silt diatom aches component due to its complexation with humic acids. An attempt is made to carry out the uranium material balance with account for uranium coming with river water and sedimentation with diatom aceous slits

  10. Metallogenic characteristic of Sasyk-kul lake water type uranium deposit

    International Nuclear Information System (INIS)

    Sasyk-kul lake water type uranium deposit is located in Pamirs uranium metallogenic area, the ore body is the lake water, uranium concentration of lake water reaches the level of industrial production solution, and can be regarded as one of special type of hydrogenic uranium deposit. Uranium metallogenesis not only includes surficial infiltration origin but also deep geothermal water origin, main reason of uranium concentration was caused by evaporation under condition of arid climate, and the deposit can be classified to the polygenetic uranium deposit. (authors)

  11. CONCENTRATION OF URANIUM IN WATERS OF THE BIGGEST LAKES OF THE TYWA RIVER DRAINAGE BASIN

    OpenAIRE

    Jacek Kubiak; Sylwia Machula

    2014-01-01

    The paper presents the results of research of uranium concentrations in its different kinds – suspended and dissolved – in waters of the largest lakes located in the catchment area of the River Tywa – Strzeszowskie Lake, Dłużyna Lake, Długie Lake and Dłuzec Lake. Small (or the order of several 0,01 µg/l) variations in concentration of uranium in different lakes were noted. The study has also shown a seasonal variation – in a similar range – in concentrations of the above species of uranium, a...

  12. Expansion of the uranium mines in the Elliot Lake area

    International Nuclear Information System (INIS)

    This report forms the response of the government of Ontario to an earlier report issued by an Envrionmental Assessment Board. Specifically, the report deals with the rapid growth of the town of Elliot Lake due to expansion of several uranium mine-mill operations. Rapid growth of small communities presents considerable problems in providing housing, essential services, and educational facilities. Several specific actions taken by the government to help the town cope with rapid growth are presented. (O.T.)

  13. Uranium and base metal dispersion studies in the Maquire Lake area, Saskatchewan

    International Nuclear Information System (INIS)

    The objective of this study was to study uranium and base metal dispersion in various sample media occurring in the Maguire Lake area of Saskatchewan: bedrock, overburden, lake water, and lake sediments. Factors controlling partitioning of metals among various sample media were investigated, and lake sediment data were interpreted in terms of the factors to determine the significance of lake sediment data in indicating local mineralization. The association between organic matter contents and metal contents was found to vary between lake-center and nearshore sediments. Nickel, cobalt and zinc in lake sediments are strongly controlled by hydroxide precipitation and are less dependent on bedrock type. The concentration of Fe in center-lake sediments appears to reflect only the physicochemical parameters in the lake. Uranium and copper are strongly controlled by and preferentially concentrated in the organic matter; however, in center-lake sediments with >12 percent organic matter, U and Cu strongly reflect rock type

  14. Acid chloride leaching of Midwest Lake uranium ore (northern Saskatchewan, Canada)

    International Nuclear Information System (INIS)

    The feasibility of acid chloride leaching (i.e. alternative leaching process) of high-grade complex uranium ore was studied on Midwest Lake uranium ore, one of the main objectives of the work being to produce effluents and tailings almost free from radioisotopes and other toxic materials. Irrespective of leachants, uranium extractions were always high (∼99%). 32 refs.; 5 tabs

  15. Elliot Lake uranium mine reclamation, the first ten years

    International Nuclear Information System (INIS)

    In 1989, Rio Algom Limited finalized its plans for the closure and subsequent decommissioning of two of its then three operating mines in Elliot Lake as a result of market conditions. These two mines closed in August 1990. These mine closures had significant impacts. The principal mining operations of Rio Algom at that time were still in Elliot Lake and had been the very foundation of the company for about 40 years. The business impact on the Corporation was regarded as possibly severe. The resultant layoff of over 1,500 long-term, highly qualified, skilled and well-paid employees, a devastating blow to the affected employees and their families, would have a significant financial impact on the municipal economy, particularly as this announcement was seen as the first step in the early closure of all four operating mines in the region. At that time there was little precedence for such a high profile mine closure program and consequently the many unknowns relating to the mine decommissioning process, legislative requirements and society's expectations resulted in a perception of a significant yet ill-defined liability. In this atmosphere of understandable company, stakeholder and public concern, Rio Algom Limited embarked on what has turned out to be a long, rigorous, challenging yet ultimately reasonable and rewarding process of progressive reclamation of all its Elliot Lake mines, some ten in total (nine uranium, one copper). Over the past ten years, reclamation of all ten mines has been successfully completed, some $70 m plus has been expended in direct site reclamation works and the workforce has been reduced from over 2,500 to just 4. After ten years, the focus of attention is now on the long-term care, maintenance, monitoring and reporting required for the decommissioned mine sites, and the accomplishment of this in the best interests of all the stakeholders. (author)

  16. Excess helium-4 in Teggau Lake: possibilities for a uranium ore body

    International Nuclear Information System (INIS)

    Excess 4He (more than five times the solubility) has been measured in Teggau Lake in northwestern Ontario. A model suggests that an adjacent mass of greater than 104 kilograms of uranium is responsible for the observed 4He excess. The area is favorable for pegmatitic uranium deposits, and the release of trapped 4He from uraninite dikes larger than 30 cubic meters (1% U3O8) provides the best explanation for the excess 4He in the lake

  17. Hydrogeochemistry and uranium fixation in the Cigar Lake uranium deposit, northern Saskatchewan

    International Nuclear Information System (INIS)

    The 1.3 billion year old Cigar Lake uranium deposit, discovered by COGEMA in 1981, is a very rich and large mineralization of uraninite-pitchblende and coffinite in the Athabasca Sandstone in northern Saskatchewan. The mineralization occurs at the -450 m deep unconformity contact of the sandstone with the underlying high-grade rocks of the basement. The sandstone, particularly its basal unit, is the regional aquifer and, due to permeability caused by extensive fracturing, groundwater is found in all parts of the deposit. The composition of this groundwater has been studied in detail over the past 3 years. The compositions of the groundwaters from different parts of the deposit reveal a reduced, redox-buffered, steady-state system of water interaction with the ore and host rock. All groundwaters, including those in contact with the mineralization, are dilute, neutral pH waters containing low concentrations of dissolved uranium (∼10-7.9 to 10-9 mol/L U). Concentrations of dissolved radium-226 and radon-222 are also low except in groundwaters sampled within the ore zone. The redox chemistry is controlled by a number of different processes, including inorganic and organic reactions, bacterial activity and radiolysis of water in the ore zone. The iron-redox couple is the main process controlling the redox conditions in the present dynamic system. The formation of iron colloids in the ore zone and the retention of these colloids in the bordering clay zone restrict the migration of naturally occurring radionuclides, such as uranium, thorium and radium, from the ore. Information from the redox, colloid and isotope chemistries is used to discuss the history of uranium fixation in this deposit. (author)

  18. Uranium

    International Nuclear Information System (INIS)

    Canada produced one-third of the Western World's uranium production in 1989, twice as much from Saskatchewan as from Ontario, where mine closures have led to the loss of over 2,000 jobs. Canadian production in 1990 was about 8.8 Gg U. In 1990, Canada's primary producers were Denison Mines, Rio Algom, Cluff Mining, and Cameco. In Saskatchewan, there are three operations: Key Lake, Rabbit Lake/Collins Bay, and Cluff Lake. Canada stands fourth in uranium resources, but because of favourable geology remains the focus of much exploration activity, which cost about C$60 in 1989. Large stockpiles overhang the market, so new sources of uranium will not be needed before the mid 1990's, but long-term prospects seem good

  19. Orientation study of the Lake Sunapee area, New Hampshire. National Uranium Resource Evaluation Program

    International Nuclear Information System (INIS)

    An orientation study was conducted in the area of Lake Sunapee, New Hampshire, in preparation for a hydrogeochemical and stream sediment reconnaissance in glacial terrain. The study was carried out by the Savannah River Laboratory as part of the National Uranium Resource Evaluation (NURE). Ground water, lake water, stream water, lake sediment, and stream sediment samples were collected at 188 sites. The concentrations of uranium and other elements were determined by neutron activation analysis. This report is issued in draft form, without detailed technical and copy editing. This was done to make the report available to the public before the end of the NURE program

  20. Rabbit Lake uranium mining a-zone, d-zone, eagle point: report of the environmental assessment panel

    International Nuclear Information System (INIS)

    A report of the environmental assessment panel on Rabbit Lake, Saskatchewan. A review of the proposed development of the uranium mining facility at Rabbit Lake with respect to the environmental, health, safety, and socioeconomic impacts

  1. Distribution and isotope uranium composition in river run-off and in lake Baikal water

    International Nuclear Information System (INIS)

    Uranium geochemistry investigation in a river run-off and conditions of its accumulation in the Baikal sea sediments is carried out. It is shown that uranium content, exceeding 0.2-0.5 μg/l is observed in the river waters, whatersheds whereof are composed of granitoid or metamorphic rocks, containing uranium and thorium. The uranium balance evaluation showed that the difference in the uranium quantity between its ingress (51.7 t/year) and discharge from the lake (25.4 t/year) constitutes 26.3 t/year. the intensity of uranium sedimentation changes from 1.8 up to 5.8x10-5 g/cm2x103 years. Diatom algae are depleted by uranium whereas organic fraction is enriched by it. 15 refs.; 4 figs.; 2 tabs

  2. Some aspects of the genesis of the uranium deposits of the Morrison formation in the Grants Uranium Region, New Mexico, inferred from chemical characteristics of the deposits

    International Nuclear Information System (INIS)

    Statistical treatment of the chemical data for samples from the Church Rock, Smith Lake, Ambrosia Lake, and Laguna districts, all in the Grants uranium region, San Juan basin, indicates that primary ore-forming processes concentrated copper, iron, manganese, molybdenum, selenium, vanadium, yttrium, arsenic, organic carbon, and sulfur, along with uranium. The initial uranium and vanadium mineralization occurred before compaction of the host rocks. A barium halo associated with all of these deposits formed as a result of secondary processes. Calcium and strontium were also enriched in the ores by secondary processes. Comparison of the chemical characteristics of redistributed deposits in the Church Rock district with those of primary deposits in the Grants uranium region indicates that calcium, manganese, strontium, yttrium, copper, iron, molybdenum, lead, selenium and vanadium are chemically separated from uranium during redistribution of the deposits in the Church Rock district. Comparisons of the chemical characteristics of the Church Rock deposits with those of the secondary deposits in the Ambrosia Lake district suggest some differences in the processes that were involved in the genesis of the redistributed deposits in these two areas

  3. Canadian Experience in Decommissioning of Uranium Tailings Facilities -- Elliot Lake, Canada

    International Nuclear Information System (INIS)

    Commencing in the 1950s, a total of approximately 12 uranium mining operations were commissioned primarily near Elliot Lake, Ontario. Many of the mines operated for only a few years before being shut down. Beginning in the early 1970s, reactivation of four mines in the Elliot Lake area commenced. The Denison Mine was owned and operated by Denison Mines Limited. The Quirke, Panel and Stanleigh Mines were owned and operated by Rio Algom Limited. With the discovery of high-grade uranium deposits in Northern Saskatchewan and the slump in uranium prices as a result of the end of the Cold War, decommissioning of the Elliot Lake Uranium Mines began in the early 1990s. Studies related to the decommissioning commenced in the late 1980s. The last operating mine, the Stanleigh Mine, was closed in 1996. The permitting, operation and decommissioning of uranium mines in Canada is primarily regulated by the Canadian Nuclear Safety Commission (CNSC), formerly the Atomic Energy Control Board (AECB). However, the provincial Departments of Environment are also involved in the process. Studies related to the decommissioning of the Denison, Quirke, Panel and Stanleigh mines commenced in the late 1980s. The Environmental Assessment Panel issued its report 'Decommissioning of Uranium Mine Tailings Management Areas in The Elliot Lake Area' in June, 1996. Monitoring, care and maintenance of the sites is ongoing. This paper will review the process of closure planning and the review process for these mines. (author)

  4. Chemical characteristics of some major uranium deposits in western USA

    International Nuclear Information System (INIS)

    Multi-element chemical analyses of several thousand samples were retrieved from the US Geological Survey's computerized Rock Analysis Storage System and used to estimate the average abundances of various elements in each of several types of uranium deposits, in altered rocks associated with some of these deposits, and in unmineralized parts of the various host rocks. Deposits for which results are presented include the tabular deposits in the Morrison Formation, Ambrosia Lake district, New Mexico; secondary deposits in the Ambrosia Lake district; tabular deposits in the Morrison Formation of the Henry Mountains, Utah; tabular deposits in the Chinle Formation in Utah and Colorado; roll-type deposits in Tertiary rocks from the Texas Gulf district; roll-type deposits in the Tertiary basins of Wyoming; tabular deposits in the Entrada Sandstone in Colorado; and a vein-type deposit in crystalline rocks of the Front Range of Colorado. Statistical treatment of the data identified elements that were notably more or less abundant in the deposits and altered rocks than in the unmineralized parts of the host rocks. Comparisons of the mean abundances of elements in the deposits show that the chemical composition of roll-type deposits varies greatly even among deposits in the same district. By contrast, the chemical characteristics of tabular deposits display little variation; the Ambrosia Lake tabular deposits and those of the Henry Mountains district are particularly similar. The data place some constraints on the geochemical aspects of genetic models and suggest certain elements as potential prospecting guides

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

    Science.gov (United States)

    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

  6. Evaluation of the uranium potential of areas covered by lake waters, using geophysical, geochemical and radiometric techniques

    International Nuclear Information System (INIS)

    To evaluate various techniques of exploring for uranium in areas underlain by lakes, the Alces Lake area was chosen for study. The lake is situated about 30km northeast of Eldorado in northern Saskatchewan (59 degrees 40 minutes N:108 degrees 0.3 minutes W). The Ace-Fay and Verna pitchblende deposits of Eldorado Nuclear Limited are associated with the St. Louis fault, which is believed to extend under Alces Lake. The lake was systematically sampled at 20-m intervals along grid-lines spaced 200m apart. At each sample location, a lake-bottom sediment sample was taken, 2 litres of lake water from the basal metre of the lake were collected and depth soundings and VLF measurements were made. The lake-water samples were analysed in the field for radon and subsequently in the laboratory for uranium. Lake sediment samples were analysed for uranium. Several of the lines were traversed with an underwater scintillometer which was operated by towing the probe along the lake bottom from a boat and also by guiding the probe along the lake bottom by scuba divers. The paper describes and evaluates the various techniques and discusses the results. In view of the fact that as much as 30% uranium districts within the Canadian Shield are covered by lake water, these techniques will be of considerable interest for the further evaluation of these uraniferous areas. (author)

  7. Mini-pilot-scale hydrochloric acid leaching of an Elliot Lake uranium ore

    International Nuclear Information System (INIS)

    An hydrochloric acid leaching process has been found to provide high uranium recoveries and low residual radium content in the tailings. Several uranium extraction process flowsheets have been developed based on hydrochloric acid leaching of uranium ores, of pyrite-free tails from pyrite flotation minerals and of magnetic concentrates from high intensity magnetic separation of radioactive minerals. Two-stage hydrochloric acid leaching of an Elliot Lake uranium ore with 4-hr. retention in each stage provided 98% overall recovery of uranium and tailings containing 30 pCi g-1 Ra. However, the economics of the acid chloride process compares unfavourably both in capital and in operating costs with the conventional sulphuric acid process, unless such a process provides significant savings in environmental costs. (orig.)

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

    International Nuclear Information System (INIS)

    The Mariano Lake uranium deposit, hosted by the Brushy Basin Member of the Jurassic Morrison Formation, occurs in the Smith Lake district of the Grants uranium region, New Mexico. The orebody, contains abundant amorphous organic material, which suggests that it represents a primary-type deposit; however, the orebody is close to a regional reduction-oxidation interface, which suggests that uranium was secondarily redistributed by oxidative processes. Uranium contents correlate positively with organic carbon contents. Petrographic evidence points to uranium residence in amorphous organic material that was postdepositionally introduced in the diagenetic history of the host sandstone. Uranium mineralization was preceded by precipitation of pyrite (δ/sup 34/S values of -11.0 to -38.2 per mil), mixed-layer smectite-illite clays, and quartz and potassium feldspar overgrowths; and also partial dissolution of some detrital feldspars. Alterations associated with uranium mineralization include precipitation of the organic material, microcrystalline quartz, and pyrite and marcasite (δ/sup 34/S values of -29.4 to -41.6 per mil), and the destruction of detrital Fe-Ti oxide grains. Following mineralization, calcite, dolomite, barite, and kaolinite were precipitated, and some iron disulfides were replaced by ferric oxides. Geochemical data and petrographic observations both indicate that the Mariano Lake orebody is a primary-type deposit. Oxidative processes have not noticeably redistributed uranium in the immediate vicinity of the deposit, nor have they greatly modified geochemical characteristics in the ore. Impedance of ground-water flow by local folds and the lower porosity characteristics of ore zones may have helped to preserve the deposit

  9. Ra-226 concentrations in otter, Lutra canadensis, trapped near uranium tailings at Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    The Elliot Lake area of Ontario, is currently the major uranium producing region of Canada. It is estimated there are 120 million tons of uranium tailings spread over 600 ha in the vicinity of Elliot Lake. The transfer and fate of uranium-series radionuclides from tailing sites remain primary ecological concerns in these areas. It has been demonstrated that the levels of radionuclides, including Ra-226, are elevated in vegetation, small mammals and fish living on or near tailing disposal sites. However, the transfer potential of Ra-226 to predatory species has not been examined in detail. The objective of this study was to measure Ra-226 levels in otters (Lutra canadensis), captured near tailing sites, to provide further information on the fate of radionuclides in the environment

  10. Uranium mine New Quirke (Rio Algom Mines) at Elliot Lake, Ontario, Canada

    International Nuclear Information System (INIS)

    A description is given of uranium ore mining at the New Quirke uranium mine of the Rio Algom Mines Company in the Elliot Lake area in Ontario, Canada. The uranium content of the ore is 0.15% and ore is extracted using the pillar and chamber technique. The product is crushed underground to a grain size of 100 mm and is hoisted by skips. Production capacity is 7000 tons per day. The mechanical dressing plant is described in detail. In 1971 it processed 2100 tons of uranium concentrate from 1.6 million tons of ore. Special attention is devoted to waste treatment, its stabilization and the improvement of soil conditions for enhancing plant growth. Water from the mine is fully neutralized and then discharged into the river. Problems of underground and surface environmental protection are being solved

  11. Structural and hydrothermal modification of the Gaertner uranium deposit, Key Lake, Saskatchewan, Canada

    International Nuclear Information System (INIS)

    The Key Lake uranium deposits are located at the southeastern edge of the Athabasca Basin, approximately 240 km north of La Ronge, Saskatchewan. Key Lake Mining Corporation is at present the world's largest uranium producer with an annual rated production of approximately 12 million pounds of U3O8. The Gaertner deposit consists of massive aggregates of uranium and nickel minerals immediately above the Early/Middle Proterozoic unconformity at its intersection with the Key Lake structural zone. Peripheral ore shoots extend along fractures into the wall rocks. The main ore minerals are uraninite and coffinite which are accompanied by Ni-arsenides, Ni-sulpharsenides and Ni-, Fe-, Pb-, Co- and Cu-sulphides. Radially textured anisotropic uraninite in the Gaertner deposit represents the oldest mineralization phase dated at 1255+-12 Ma. A series of tectonic events and accompanying hydrothermal mobilization and alteration resulted in modifications of the original monomineralic uranium orebody. Based on ore microscopic examinations and field observations in the Gaertner open pit, the following modification stages are identified: 1. ∼900 Ma: Fracturing of radially textured anisotropic uraninite, the oldest recognised uranium ore, subsequent introduction of Ni, As, S, Fe, Co and Cu. Radiometric dating of associated coffinite indicates an age of approximately 900 Ma. 2. ∼300 Ma: Renewed fracturing of the nickeliferous uranium ore stockwork, hydrothermal carbonate and clay alteration with dispersion of mobilized elements into the wall rocks, and multiple redistribution/introduction of U under varying physico-chemical conditions. On the basis of isotropy and optical reflectivity, four uraninite/pitchblende generations are distinguished in addition to a second nickel mineral suite and a coffinite phase. 3. <300 Ma: Vertical offset within the deposit under shallow conditions. Hydrothermal activity is not apparent. (author). 13 refs, 10 figs

  12. Near-field analog features from the Cigar Lake uranium deposit

    International Nuclear Information System (INIS)

    The Proterozoic Cigar Lake uranium deposit in northern Saskatchewan is being studied as a natural analog system that includes many features similar to those of a conceptual disposal vault for used fuel. The more than one billion year old deposit has survived without significant dispersion and, at present, without any direct indications at surface as to its presence at a depth of about 450 m. This paper gives a description of the deposit and its analog features, including uranium mineralogy, clay mineralogy and host rock alteration, radionuclide migration, groundwater composition, colloids and radiolysis. (author)

  13. Ecological distribution and bioavailability of uranium series radionuclides in terrestrial food chains: Key Lake uranium operations, northern Saskatchewan

    International Nuclear Information System (INIS)

    The purpose of this study was to determine radionuclide uptake within the terrestrial ecosystem at uranium mining operations in northern Saskatchewan. The study site was the Key Lake mine, chosen because it has been an operational mine, mill, and surface tailings area for 15 years and will continue to be an active ore-milling and tailings disposal area for the next 40 years. The focus of the study was on the small mammal food chains in black spruce bogs nearest to the Key Lake facilities, since bog habitats tend to absorb and accumulate radionuclides. Three study sites were chosen on the basis of their proximity to sources of radioactive dust and the presence of bog habitats. Interconnected terrestrial ecosystem components were sampled at the same time at each site. Samples of needles, twigs, ground cover, litter, soils, small mammals, and birds were analyzed for the four radionuclides of greatest concern in the uranium decay series. Radiation doses were calculated to small mammals and birds, food chain transfer parameters were determined to enable future modelling of environmental pathways, and a variety of atmospheric dust collectors were pilot tested to examine the rates of radionuclide deposition from facility emissions to local environments. Four sets of conclusions are discussed regarding: radionuclide distribution within habitats and among sites; the radionuclides responsible for animal doses; the relative bioavailability of radionuclides among sites; and the measurement of atmospheric deposition rates

  14. 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)

  15. The Cigar Lake uranium deposit: Analog information for Canada's nuclear fuel waste disposal concept

    International Nuclear Information System (INIS)

    The Cigar Lake uranium deposit, located in northern Saskatchewan, has many features that parallel those being considered within the Canadian concept for disposal of nuclear fuel waste. The study of these natural structures and processes provides valuable insight toward the eventual design and site selection of a nuclear fuel waste repository. The main feature of this analog is the absence of any indication on the surface of the rich uranium ore 450 m below. This shows that the combination of natural barriers has been effective in isolating the uranium ore from the surface environment. More specifically, the deposit provides analog information relevant to the stability of UO2 fuel waste, the performance of clay-based and general aspects of water-rock interaction. The main geotechnical studies on this deposit focus on the evolution of groundwater compositions in the deposit and on their redox chemistry with respect to the uranium, iron and sulphide systems. This report reviews and summarizes the analog information and data from the Cigar Lake analog studies for the processes and scenarios expected to occur in the disposal system for used nuclear fuel proposed in Canada. (author). 45 refs., 10 figs

  16. Cameco Corporation - The Key Lake uranium mill. Current status and vision for the future

    International Nuclear Information System (INIS)

    The Key Lake mill located approximately 570 km north of Saskatoon, Saskatchewan, Canada and is currently the world's largest primary producer of uranium producing 8. 106 kg U3O8 annually. The feed to the Key Lake mill currently originates from the McArthur River mine, an underground mine located approximately 80 kilometers north of the Key Lake mill. The McArthur River mine, located within the Athabasca Basin, is the world's largest high-grade uranium deposit with proven and probable reserve, as of 31 December 2003 of 190 million kg U3O8. Approximately 700 people are employed at Key Lake and McArthur River of which 57% of the workforce are residents of Saskatchewan's north. The mine site and mill are remote and employees commute via air travel to and from the sites from Saskatoon, Saskatchewan as well as communities throughout northern Saskatchewan. Employees work a 7-day in/7-day out work rotation and reside in permanent camps during the work week at the mine and mill. (author)

  17. Elliot Lake. Uranium mining - a life cycle review

    International Nuclear Information System (INIS)

    The mine decommissioning programs were designed to address the principle and key issues associated with our particular facilities and wastes in relation to location and local conditions. The key concerns were identified as the residual low-level radioactivity associated with the mine wastes (tailings) together with the potential for acid generation as a consequence of the average 5 to 7% pyrite associated with the orebody. In developing the plans, consideration was given to relatively remote and sparsely populated area that the minesites were in, the limited current or future land use for the rocky terrain, and therefore a limited pressure on development of alternative land use, the geological and climatic conditions and the abundance of freshwater lakes in the region. Also, the mines had been responsibly operated and managed for many years therefore had few significant or difficult site conditions to deal with at closure. Decommissioning plans were prepared to address the three areas of the facilities, namely the underground workings, surface processing and maintenance facilities and particularly the tailings/waste from the mine operations. (orig.)

  18. Derivation of uranium residual radioactive material guidelines for the 4400 Piehl Road Site, Ottawa Lake, Michigan

    International Nuclear Information System (INIS)

    Residual radioactive material guidelines for uranium were derived for the 4400 Piehl Road site in Ottawa Lake, Michigan. This site has been designated for remedial action under the Formerly Utilized Sites Remedial Action Program (FUSRAP) of the US Department of Energy (DOE). Single nuclide and total uranium guidelines were derived on the basis of the requirement that the 50-year committed effective dose equivalent to a hypothetical individual who lives or works in the immediate vicinity of the 4400 Piehl Road site should not exceed 30 mrem/yr following remedial action for the current use and plausible future use scenarios. The DOE residual radioactive material guideline computer code, RESRAD, which applies the methodology described in the DOE manual for implementing residual radioactive material guidelines, was used in this evaluation

  19. Transport modelling in the natural analogue study of the Cigar Lake uranium deposit (Saskatchewan, Canada)

    Science.gov (United States)

    Liu, Jinson; Yu, Ji-Wei; Neretnieks, Ivars

    1996-02-01

    A near-field release model is developed both conceptually and mathematically. The model is tested against known helium release from the Cigar Lake uranium ore deposit. The release and transport of various aqueous species (including some radionuclides) in the deposit are studied by using this model. The uranium release rate predicted by the model is extremely low, which is consistent with field observations. In modelling the release of three other radionuclides ( 3H, 14C and 36Cl), the in situ generation and decay are taken into account. The measured concentration gradients of hydrogen was used to estimate the net rate of radiolysis. The simultaneously formed oxidising species are found in sulphates formed by oxidation of sulphides. There is a good agreement of the estimated rate of formation of the reducing component hydrogen and the oxidising component as found in the sulphate.

  20. Canadian regulatory and technical requirements for uranium mine decommissioning Elliot Lake, Ontario experience

    International Nuclear Information System (INIS)

    Uranium mining in Canada is regulated by the Atomic Energy Control Board (AECB), a federal nuclear control agency whose mission is to ensure that the use of nuclear energy in Canada does not pose undue risk to health, safety, security and the environment. The mining of uranium is regulated by the Atomic Energy Control Act and specifically the Uranium and Thorium Mining Regulations. While the AECB remains the lead regulatory agency, other relevant federal and provincial regulatory bodies are also involved. The regulatory process involves the issuing of licences for specific activities during the life cycle of a mine from siting, construction, operation to decommissioning. The AECB objectives with respect to decommissioning nuclear facilities and uranium mines are to minimize any burden placed on future generations, protect the environment and human health taking into account social and economic factors. This is achieved through a non prescriptive approach where each decommissioning plan is evaluated on a case-by-case basis. This paper illustrates the technical and regulatory requirements that have been applied by the AECB through a number of site specific examples from the recent decommissioning activities undertaken in the Elliot Lake Area situated in Northern Ontario. These decommissioning projects follow a staged approach which includes initial, transitional and closure phases. The most challenging aspect is the long-term management of the acid generating tailings. The regulatory and technical requirements related to the long-term environmental performance, structural integrity and maintenance of the tailings management facilities will be described in detail. (author)

  1. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, H.; Ferrari, C.; Roque, C.V.; Nascimento, M.R. [Brazilian Nuclear Energy Commission/Pocos de Caldas Laboratory (Brazil); Wisniewski, M.J. [Alfenas Federal University/Limnology Laboratory (Brazil); Rodgher, S. [Universidade Estadual Paulista Julio de Mesquita Filho/Science and Technology Laboratory (Brazil)

    2014-07-01

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m{sup -3}), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  2. An overview of a uranium acidic mining lake (Caldas, Brazil): composition of the zooplankton community and limno-chemical aspects

    International Nuclear Information System (INIS)

    This research represents an attempt to fill a gap in the information on the zooplankton composition and limno-chemical aspects of the uranium pit lake (Osamu Utsumi Pit, Brazil), affected by acid mine drainage. In the present study water samples were collected three-monthly, for a period of one year (2008-2009). The water samples from the uranium pit lake showed moderately acidic pH values (3.6 to 4.1), high values of the electrical conductivity, sulfate, uranium, fluoride, zinc, manganese and aluminum concentrations. The Rotifera cephalodella sp., Keratella americana, K. cochlearis, Bdelloidea order and the Cladocera Bosminopsis deitersi, Bosmina sp., were registered in the samples from the uranium pit lake with ADM. Of the species registered the Bdelloidea order was the most important in terms of density (17,500 - 77,778 ind m-3), since it occurred throughout the whole sampling period. In this study, probably the combined effect of moderately acid pH values and other potentially co-stressors factors, for example the high concentrations of stable and radioactive chemical species, could have influenced this richness and also the composition of the zooplankton species in the water samples from the uranium pit lake. Document available in abstract form only. (authors)

  3. Mapping of uranium and phosphorus in sediments of Lakes Baikal and Issyk-Kul by neutron-induced autoradiography

    International Nuclear Information System (INIS)

    The uranium and phosphorus distribution in sediment cores from the axial part of the Akademicheskiy Ridge in Lake Baikal and in the southern coastal part of Lake Issyk-Kul were studied using neutron-induced autoradiography based on the 235U(n,f) and 31P(n,β)32P reactions. The composition, morphology and structure of the mineral phases which include U and P, were studied by an electron microprobe, combined with scanning and transmission electron microscopy. Layers and concretions of uranium-bearing phosphorite (U and P concentration of about 50 ppm and 19.2 wt%, respectively) were identified by autoradiography in the sediments of Lake Baikal. These layers may be considered as good paleomarkers for sediment chronology in Lake Baikal. The phosphorites consist of a metastable phase of calcium-deficient phosphate which has not been observed before in sediments and rocks

  4. Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill

    Energy Technology Data Exchange (ETDEWEB)

    Kelly, Jocelyn M. [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3 (Canada); Janz, David M., E-mail: david.janz@usask.ca [Toxicology Centre, University of Saskatchewan, 44 Campus Drive, Saskatoon, SK, S7N 5B3 (Canada); Department of Veterinary Biomedical Sciences, Western College of Veterinary Medicine, University of Saskatchewan, 52 Campus Drive, Saskatoon, SK, S7N 5B4 (Canada)

    2009-05-17

    Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most

  5. Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill

    International Nuclear Information System (INIS)

    Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most

  6. Assessment of oxidative stress and histopathology in juvenile northern pike (Esox lucius) inhabiting lakes downstream of a uranium mill.

    Science.gov (United States)

    Kelly, Jocelyn M; Janz, David M

    2009-05-17

    Lakes receiving effluent from the Key Lake uranium mill in northern Saskatchewan contain elevated trace metals, some of which are associated with increased reactive oxygen species (ROS) in cells and tissues causing oxidative stress. The potential for oxidative stress was assessed in juvenile (age 1+) northern pike (Esox lucius) collected from two exposure (high and low) and one reference lake near the Key Lake operation. The concentrations of total, reduced and oxidized glutathione and the ratio of oxidized to reduced glutathione in liver and kidney did not differ significantly among pike collected from exposure and reference lakes, with the exception of low exposure pike kidney that had significantly greater oxidized glutathione and ratio of oxidized to reduced glutathione. The concentrations of by-products of lipid peroxidation (malondialdehyde and 4-hydroxyalkenal) were significantly greater in kidney of pike collected from the reference lake compared to both exposure lakes. The activity of the antioxidant enzyme glutathione peroxidase in liver was greater in pike collected from the high exposure lake compared to the reference lake. Histopathological evaluations revealed greater pathology in reference lake pike as indicated by a greater number of pyknotic and fragmented nuclei and dilated tubules as well as a thickening of Bowman's capsule in kidney, and as a thickening of the primary filament epithelial padding in gills. In liver, hepatocyte morphology, including transsectional area and degree of vacuolation, differed among lakes without any clear signs of pathology. Trace metal analyses of muscle showed that eight elements (arsenic, cobalt, copper, iron, molybdenum, selenium, thallium, and uranium) were significantly elevated in pike collected from both exposure lakes compared to reference. These results provide only limited evidence of oxidative stress in exposure pike tissues and no evidence of histopathology despite indications that trace metals, most

  7. Radon progeny inhalation study as applicable to uranium mining operations. Fifth annual progress report covering the calendar year 1969

    Energy Technology Data Exchange (ETDEWEB)

    Schiager, K.J.

    1970-02-28

    The main efforts of the past year have been directed towards investigation of the behavior of the radioactive aerosols in actual in mining operations. Activities can be categorized as follows: Preparation of equipment for taking data in uranium mines; development of background of personnel to carry out intended experiments; research data from United Nuclear Homestake Partners Section 25 mine in the Ambrosia Lake area near Grants, New Mexico; updating of computer programs for data analysis in order to extract more information; and the development of a thermal precipitator for partical size analysis in the submicron range.

  8. Decommissioning of Elliot Lake Uranium Mines - Site Performance and Long-Term Radium Mobility

    International Nuclear Information System (INIS)

    Low ore grade and uranium market conditions led to the closure of all uranium mines in the Elliot Lake region of north-central Ontario, Canada. This was followed by rehabilitation and decommissioning of all previously closed, inactive (past historic) and recently closed-out mines and associated waste management facilities in accordance with the licensing requirements of the Canadian Nuclear Safety Commission (CNSC). Acid mine drainage and contaminant migration, including uranium decay series radionuclides and trace heavy metals, from waste management areas are major environmental concerns at many of these sites. Hence, long term prevention, control and treatment measures are required. In the past, many older and inactive surface-deposited waste management sites, having acidic drainage problems, were rehabilitated with vegetation covers. This has controlled surface erosion and greatly improved site aesthetics. However, acidic drainage continues at these sites and long term effluent collection and treatment measures are required. The waste management areas at the newer, recently closed mines have been rehabilitated with shallow, in situ water covers, having a minimum depth of approximately 1m, to minimize acid generation and release of radon gas and its progeny. Acid generation at these sites has decreased significantly and at most sites only a limited effluent treatment is required for pH control and radium removal. The mobility of Ra-226 from pyritic uranium tailings was evaluated for both on-land and underwater disposal scenarios. During the acid generation phase and/or in the presence of available sulphate ions, the dissolution and mobility of radium was very low due to sulphate ion solubility control. With the cessation of acid generation, and/or upon depletion of sulphate ion control, including microbial sulphate degradation, the solubility of radium was enhanced. Hence, further investigations are needed to improve the understanding of the long term stability

  9. Po-210 and Pb-210 in water and fish from Taboshar uranium mining Pit Lake, Tajikistan

    International Nuclear Information System (INIS)

    Polonium-210 in water and 210Pb and 210Po in different fish organs from 3 different fish species in Taboshar Pit Lake (n = 13), located in the uranium mining area in Tajikistan, and in Kairakkum Reservoir (reference lake, n = 3), have been determined as part of a Joint project between Norway, Kazakhstan, Kyrgyzstan and Tajikistan. The average activity concentration of 210Pb and 210Po in liver, muscle and bone of Carassius auratus was higher than the concentration in similar tissues of C. carpio and Sander lucioperca from the reference site. The accumulation of 210Po was higher than for 210Pb, and the accumulation of 210Po was highest in the liver of C. auratus (3673 ± 434 Bq kg−1 ww). Although the average activity concentration of 210Pb in liver and bones of C. auratus from Pit Lake were fairly similar, a huge variation in the liver activity concentrations (25–327 Bq kg−1 ww) was found. The results confirm direct uptake of unsupported 210Po into the liver, and that the distributions of 210Po and 210Pb in fish organs were different. The BCF (L/kg) for 210Po in bone, liver and muscle clearly demonstrates high accumulation of 210Po in C. auratus, especially in the liver. The average BCFs of liver, bone and muscle were >1.4 × 105, >2.5 × 104 and >1.4 × 104, respectively. All fish in the Pit Lake were found to be in the same trophic level, however, a linear correlation between log 210Po in liver and δ15N could indicate biomagnification of 210Po in liver of C. auratus. In regards to the recommended Annual Limit of Intake (ALI) for 210Po, the concentration of 210Po in muscle tissues of C. auratus is alarming, as there is a high probability for the local population at risk to exceed the recommended ALI through consumption of fish from Taboshar Pit Lake

  10. Liquid effluent treatment initiatives at the Key Lake uranium mine, Saskatchewan, Canada, 1996-2000

    International Nuclear Information System (INIS)

    The Canadian paper focuses on liquid effluent-related work at the Key Lake mine in Northern Saskatchewan. Over the 1996-2000 period covered under this CRP, the work at Key Lake focused primarily on better understanding how the mine site's effluents impact the near-field aquatic environment. Three separate projects were tracked in this paper: i) an assessment of the significance of elevated nickel and molybdenum concentrations in the mine dewatering and mill effluents; ii) a report on efforts to determine and eliminate the cause of fish toxicity in Key Lake mill effluent; and iii) a report on efforts made to reduce nickel loadings to the environment from Key Lake mine dewatering effluent. The paper also provides a history of the Key Lake site as it relates to liquid effluent, describes the effluent treatment processes, reviews current environmental impact against original predictions made in the Environmental Impact Statement written in 1979 prior to start-up, and finally, reviews some of the wider issues facing Canadian uranium producers. In terms of nickel toxicity, a series of four studies over the past eight years have essentially not found significant environmental impact in the nearfield receiving environment. However, the studies also essentially site-validated the receiving water quality objective established for nickel to protect the most sensitive species from biological harm (in their early life cycles). With respect to molybdenum toxicity, site-specific laboratory studio concluded that waterborne Mo was not toxic to any life stage of any fish species tested. Field-based early life cycle testing showed sore response in Mo-containing waters, however dietary selinium toxicity is the suspected cursitive agent, despite very low waterborne Se levels. The overall conclusion on early life cycle toxicity testing, particularly using indigenous fish species, is that they are difficult to conduct, easy to critique, can generate variable results, and do not

  11. Interim report on studies of uranium, thorium, and lead migration at Key Lake, Saskatchewan, Canada

    Energy Technology Data Exchange (ETDEWEB)

    Curtis, D.B.; Gancarz, A.J.

    1980-07-01

    The redistribution of uranium, thorium, and lead is being examined in samples representing several million cubic meters of sandstone and metamorphased sediments in the Athabasca Basin which is located in the northwest corner of the Canadian province of Saskatchewan. The region of study includes zones of uranium mineralization at Key Lake. Mineralization occurs at the unconformity between the Athabasca sandstone and the underlying metasediments and in fault zones within the metasediments. Lead isotopes record a radiometric age of 1300 +- 150 m.y. in samples from above and below the unconformity. This age probably reflects the time of deposition of the sandstones and an associated redistribution of uranium and/or lead in the underlying rocks. Many of the samples have been fractionated with respect to radiogenic lead and the actinide parent elements since that time. Sandstones and altered rocks from the region above the unconformity have been a transport path and are a repository for lead. In contrast, mineralized rocks are deficient in radiogenic lead and must be an important source of lead in the local geologic environment. However, the isotopic composition of lead missing from the ores is different from that found in the overlying sandstones. The two types of rocks do not appear to represent complements with respect to a source and a repository for lead.

  12. Uranium

    International Nuclear Information System (INIS)

    The article includes a historical preface about uranium, discovery of portability of sequential fission of uranium, uranium existence, basic raw materials, secondary raw materials, uranium's physical and chemical properties, uranium extraction, nuclear fuel cycle, logistics and estimation of the amount of uranium reserves, producing countries of concentrated uranium oxides and percentage of the world's total production, civilian and military uses of uranium. The use of depleted uranium in the Gulf War, the Balkans and Iraq has caused political and environmental effects which are complex, raising problems and questions about the effects that nuclear compounds left on human health and environment.

  13. Data report: Jean Lake Area, Nevada. National Uranium Resource Evaluation Program

    International Nuclear Information System (INIS)

    This report presents the results of detailed sampling of soils, rocks, and dry lake bed material from the area of Jean Dry Lake in southern Nevada. The study area is in the Kingman 10 x 20 quadrangle of the National Topographic Map Series. Samples were collected from 1000 sites. The target density of sampling was 16 sites per square mile in the lake bed and four sites per square mile for soil samples. Neutron activation analyses are presented for uranium and 16 other elements. Scintillometer readings are reported for each site. Analytical data and scintillometer measurements are presented in tables. Statistical summaries and a brief description of the results are given. Data from the sites (on microfiche in pocket) include; (1) elemental analyses (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, and V); and (2) scintillometer readings. To make the data available for public use without further delay, this report is being issued without the normal technical and copy editing

  14. Geochemistry of the waters associated with the Cigar lake uranium deposit (Saskatchewan, (CA)) and their uranium and lead isotope contents as guides for prospecting

    International Nuclear Information System (INIS)

    The primary objective of this study is to understand the chemical evolution of the waters crossing the Cigar Lake (Saskatchewan, Canada) uranium ore deposit, then to investigate the behavior of the lead and uranium isotopes, and to test their use as guides in exploration. The underground waters around the Cigar Lake ore deposit were sampled by pumping boreholes or by air lifting. Isotopic analyses of U and Pb and chemical analyses of the major elements and of some trace elements (Ba, Ra, U) were completed. Based on these results, a model is proposed to explain the genesis and evolution of the waters, and also to account for the water-minerals equilibria. 37 refs., 8 figs., 4 tabs

  15. Geology and genesis of uranium deposits in the early proterozoic: Blind River - Elliot Lake Basin, Ontario, Canada

    International Nuclear Information System (INIS)

    Large stratiform uranium deposits in the Blind River - Elliot Lake basin, Ontario, Canada, occur in early Proterozoic siliciclastic beds and lenses deposited in paleo-depressions and marginal portions of a pericratonic basin at the southern margin of the Canadian Shield. They are heavy mineral concentrations deposited syngenetically with quartz pebble conglomerate. The beds form the basal part of the Huronian Supergroup deposited between 2.6 and 2.25 Ga ago. Uranium mineralogy shows evidence of later modification by epigenetic processes. A conceptual genetic model for formation of the deposits is as follows: (a) derivation of uranium-bearing detritus from granitic source rocks, which were emplaced during the Kenoran Orogeny; (b) fluvial transportation of this detritus under oxygen-deficient conditions (between 10-2 and 10-6 Pal (Present Atmospheric Level)) and deposition of the well-sorted material as placer concentrations; and (c) diagenetic modification of the deposits associated with formation of authigenic minerals such as 'brannerite' (a U-Ti-Si phase) and coffinite. The uraniferous conglomerate consists of quartz pebbles embedded in an arkosic matrix with abundant pyrite, uraninite, 'brannerite', monazite, zircon and other heavy minerals. Locally hydrocarbon seams, veins and nodules are found in the conglomerate and they contain elevated amounts of uranium and gold. Several uranium-bearing conglomerate beds (reefs), indicate cyclic sedimentation related to epeirogenetic movements of the source area and/or the depositional sites. The main reefs form large sheet-like bodies containing from 10,000 to more than 100,000 tonnes of uranium metal. The younger members occur in the Elliot Lake segment, i.e. in the Quirke syncline. The Huronian Supergroup is intruded by gabbroic dykes and locally contains intercalated gabbroic sills. The mines in the Blind River - Elliot Lake basin have, from 1955 until the end of 1984, produced 108,847 tonnes of uranium metal from ores

  16. Solvent degradation and high sulphuric acid stripping in the Rabbit Lake uranium mill

    International Nuclear Information System (INIS)

    The Rabbit Lake uranium mill started processing Collins Bay B-Zone ore in 1985 using the conventional process of acid leaching/tertiary amine extraction followed by a new stripping method employing 400 g/L sulphuric acid as the stripping agent. By mid-1986 a large portion of the tertiary amine component of the solvent had degraded, producing a waxy gel which resulted in numerous operational problems and eventually required replacement of the solvent inventory. This paper describes several aspects of this problem including: i) plant experience; ii) identification of the degradation products as secondary amines complexed with sulphuric acid as both cationic and anionic complexes; and iii) testwork directed at the resolution of the solvent degradation problem. This latter program identified the key operational parameters which must be controlled to prevent a recurrence of the problem, thereby allowing for routine use of the high acid stripping process

  17. Microbiological treatment of uranium mine waters

    International Nuclear Information System (INIS)

    Percolation of uranium mine discharge water through Ambrosia Lake, NM, soil is shown to be an effective method for lowering selenium, uranium, molybdenum, and sulfate concentrations in the mine water. Selenium concentrations were lowered from approx.1.6 to <0.05 mg/L by reduction of soluble selenate and selenite to insoluble selenium metal. This reaction is most likely performed by bacteria belonging to the genus Clostridium. In addition, sulfate-reducing bacteria in the soil, such as Desulfovibrio bacteria, metabolize sulfate to hydrogen sulfide, which reacts with uranyl and molybdate ions to form insoluble uranium and molybdenum species. The concentrations of sulfate, uranium, and molybdenum were reduced to less than 600, 0.1, and 0.05 mg/L, respectively. A qualitative understanding of the effects of mine water temperature, flow rate, and nutrients on metals removal is provided. The process was successfully field tested for 7 months in a soil column 1.5 m deep. 13 references, 3 figures, 4 tables

  18. Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

    International Nuclear Information System (INIS)

    This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site

  19. Baseline risk assessment of ground water contamination at the uranium mill tailings site Salt Lake City, Utah

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    This baseline risk assessment of groundwater contamination at the uranium mill tailings site near Salt Lake City, Utah, evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium ore processing site. The tailings and other contaminated material at this site were placed in a disposal cell located at Clive, Utah, in 1987 by the US Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate residual ground water contamination at the former uranium processing site, known as the Vitro processing site. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine the appropriate remedial action for contaminated ground water at the site.

  20. From uranium mine to fishing lake: Environmental remediation in France’s Limousin region

    International Nuclear Information System (INIS)

    Artificial lakes, fishing spots and solar farms dot the landscape in France’s Limousin region, where uranium operations have gradually come to an end. This transformation would not have been possible without stakeholder involvement, transparent processes and well-coordinated activities, said Yves Marignac, the coordinator of the French Pluralistic Expert Group (GEP), involved with remediation activities in the region. The local population had an important consultative role during the environmental remediation programme, and they now use the former mining sites for recreation. “A consultative approach to remediation management is key to having the people’s support when we had to deal with the closing of the uranium mining sites in Limousin,” Marignac said. Uniquely, the non-governmental organizations (NGOs) were the driving force behind broadening the scope of environmental remediation, he added. An important factor for any successful remediation project is public engagement in the decision-making process. The local communities have the most interest in successful environmental remediation, and they need to get satisfactory answers to questions on why, when and how will it impact them. “Their involvement is vital and necessary to ensure technically sound and socially acceptable decisions,” Marignac said

  1. A qualitative evaluation of long-term processes governing the behaviour of uranium mill tailings placed in deep lakes

    International Nuclear Information System (INIS)

    The emplacement of uranium mill tailings in deep lakes may provide an acceptable method of tailings disposal at certain sites in Canada. Disposal in a depositional environment typical of deep lakes appears to offer greater prospects for long-term stability than present methods of land-based management. From the regulatory point of view, it is necessary to know which factors should be taken into account in assessing the acceptability of such an approach. This report examines the environmental variables governing the behaviour of radionuclides and trace elements in the groundwater systems, lake water, and finally in the biosphere over the short and long term. Physical, chemical and biological factors are each considered. Conclusions are presented in terms of points for and against disposal in deep lakes. This report summarizes the data and conclusions presented in an annex volume

  2. A study of facilities relative to stabilization of uranium mill tailings at Elliot Lake

    International Nuclear Information System (INIS)

    The total project capital cost of facilities to stabilize uranium mill tailings at Elliot Lake while producing 350,000 short tons per year of sulphuric acid and 266,000 short tons per year of triple superphosphate is approximately 153 million dollars. This includes pyrite flotation, roasting, acid and phosphate production, site preparation, utilities and project overhead. A new operating credit of 20.43 dollars per short ton of acid is estimated, achieved from the sale of steam and fertilizer. Two alternatives to the above were also examined, as follows: a) Production of 596,000 short tons per year of acid, and the sale of 246,000 short tons which are in excess of the Elliot Lake mill's requirement. The capital cost of this scheme is approximately 89 million dollars, with a net operating credit of 14.97 dollars per short ton of acid. b) Production of only 350,000 short tons per year of acid. This would entail disposal of the excess pyrite floated from the Rio Algom mills. The capital cost of this scheme is approximately 75 million dollars, with an operating cost of 10.47 dollars per short ton of acid

  3. Formation and evolution of the Cigar Lake uranium deposit based on U-Pb and K-Ar isotope systematics

    International Nuclear Information System (INIS)

    A systematic geochronological study was conducted on the Cigar Lake uranium deposit. U-Pb and Pb-Pb systematics were applied to different types of uranium ore, and various associated sheet silicates were dated by the K-Ar method. These two approaches define a widespread retrograde metamorphic event in the basement, which occurred at about 1780 Ma during the Hudsonian orogeny, and a four-stage evolutionary model for the ore deposit. This model is compatible with the history of other unconformity-type uranium deposits in the Athabasca Basin. The first stage in the evolution of the Cigar Lake uranium deposit is marked by uraninite crystallization at 1341 ± 17 Ma, which, in association with arsenides and sulfarsenides, constitutes the mineralization of economic interest (main orebody). The second stage, characterized by a Fe-kaolinite and Fe-illite paragenesis, occurred locally at about 900 Ma. The third stage involved uranium mobilization at about 325 Ma and is characterized by (i) preferential loss of radiogenic lead from primary uraninite and crystallization of pitchblende at the rims of uraninite grains and (ii) formation of pitchblende associated with Fe sulfides or hematite in the main and perched orebodies. The last stage is characterized by recent alteration and coffinitization which have affected all ore types. 40 refs., 8 figs., 3 tabs

  4. Ragweed (Ambrosia sp. seeds in bird feed

    Directory of Open Access Journals (Sweden)

    Frick, G.

    2011-01-01

    Full Text Available In 2005, the Swiss official feed inspection of Agroscope Liebefeld-Posieux Research Station (ALP was mandated to check bird feed and raw materials for the presence of Ambrosia sp. seeds. Indeed, such seeds were found in varying amounts when analyzed in the feed microscopy laboratory. The producers were informed, and a limit of intervention (50 mg.kg-1 ≈ 9 to 10 seeds.kg-1 was finally set for this undesirable component. The results of five years of controls show, at first, around 50% of contaminated samples. With appropriate measures, the level of contamination could be lowered in the following years. In parallel, the size of Ambrosia sp. seeds and the sieves to be used for routine analyses were checked. Ambrosia sp. seeds found in feed checked in Switzerland were seldom larger ("wider" than 3.5 mm and never smaller than 1.5 mm. Several EU Member States started their own control and monitoring programs. The results of studies from Germany, Slovenia and Denmark, presented by their feed microscopists at the IAG meetings, indicate the presence of Ambrosia sp. seeds in 21 to 75% of the products put on the market.

  5. Uranium

    International Nuclear Information System (INIS)

    With the worldwide revival of nuclear energy comes the question of uranium reserves. For more than 20 years, nuclear energy has been neglected and uranium prospecting has been practically abandoned. Therefore, present day production covers only 70% of needs and stocks are decreasing. Production is to double by 2030 which represents a huge industrial challenge. The FBR-type reactors technology, which allows to consume the whole uranium content of the fuel, is developing in several countries and will ensure the long-term development of nuclear fission. However, the implementation of these reactors (the generation 4) will be progressive during the second half of the 21. century. For this reason an active search for uranium ores will be necessary during the whole 21. century to ensure the fueling of light water reactors which are huge uranium consumers. This dossier covers all the aspects of natural uranium production: mineralogy, geochemistry, types of deposits, world distribution of deposits with a particular attention given to French deposits, the exploitation of which is abandoned today. Finally, exploitation, ore processing and the economical aspects are presented. Contents: 1 - the uranium element and its minerals: from uranium discovery to its industrial utilization, the main uranium minerals (minerals with tetravalent uranium, minerals with hexavalent uranium); 2 - uranium in the Earth's crust and its geochemical properties: distribution (in sedimentary rocks, in magmatic rocks, in metamorphic rocks, in soils and vegetation), geochemistry (uranium solubility and valence in magmas, uranium speciation in aqueous solution, solubility of the main uranium minerals in aqueous solution, uranium mobilization and precipitation); 3 - geology of the main types of uranium deposits: economical criteria for a deposit, structural diversity of deposits, classification, world distribution of deposits, distribution of deposits with time, superficial deposits, uranium

  6. Uranium

    International Nuclear Information System (INIS)

    The author discusses the contribution made by various energy sources in the production of electricity. Estimates are made of the future nuclear contribution, the future demand for uranium and future sales of Australian uranium. Nuclear power growth in the United States, Japan and Western Europe is discussed. The present status of the six major Australian uranium deposits (Ranger, Jabiluka, Nabarlek, Koongarra, Yeelerrie and Beverley) is given. Australian legislation relevant to the uranium mining industry is also outlined

  7. Uranium

    International Nuclear Information System (INIS)

    The development, prospecting, research, processing and marketing of South Africa's uranium industry and the national policies surrounding this industry form the headlines of this work. The geology of South Africa's uranium occurences and their positions, the processes used in the extraction of South Africa's uranium and the utilisation of uranium for power production as represented by the Koeberg nuclear power station near Cape Town are included in this publication

  8. Uranium

    International Nuclear Information System (INIS)

    A discussion is given of uranium as an energy source in The Australian economy. Figures and predictions are presented on the world supply-demand position and also figures are given on the added value that can be achieved by the processing of uranium. Conclusions are drawn about Australia's future policy with regard to uranium (R.L.)

  9. Uranium

    International Nuclear Information System (INIS)

    The geological setting of uranium resources in the world can be divided in two basic categories of resources and are defined as reasonably assured resources, estimated additional resources and speculative resources. Tables are given to illustrate these definitions. The increasing world production of uranium despite the cutback in the nuclear industry and the uranium requirements of the future concluded these lecture notes

  10. Survey of the occurrence of Ra-226 in the Rio Algom Quirke I uranium mill, Elliot Lake

    International Nuclear Information System (INIS)

    The main solution ore and residue pulp streams in the Rio Algom Quirke I uranium mill at Elliot Lake have been sampled and analyzed for radium-226. Analysis of the ore and leached residues indicates that Ra-226 dissolves and precipitates within the first pachuca tank. A maximum of approximately 0.2% of the Ra-226 in the ore remains in solution during leaching. (author)

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

    Science.gov (United States)

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

    2015-11-01

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

  12. Uranium deposits of the Grants mineral belt: geochemical constraints on origin

    International Nuclear Information System (INIS)

    A polygenetic origin of the uranium deposits of the Grants mineral belt is consistent with geologic and geochemical evidence. The characteristic suite of elements associated with uranium from distant source areas, viz. V, Mo, Se, As, indicates processes for deposition similar to those for Wyoming and Texas roll types of deposits, except that the rates of deposition were probably more dynamic thus leading to primary ore body geometries described as trend ore. Organic matter is associated with the ore and was important for both transport and precipitation; directly by providing reductants in addition to sulfide: sulfate redox reactions, and indirectly by promoting attack on allogenic rock forming and early formed diagenetic clay minerals. The trend ore in the Ambrosia Lake district and Smith Lake area is very nearly syngenetic; recent Rb-Sr age determinations yield ages of mineralization for coffinite-chlorite-organic carbon-pyrite assemblages of 135 +- 10 My as opposed to age of sedimentation for barren host rock of 145 +- 10 My. Only in the Jackpile-Paguate area are ages of mineralization quite different, i.e., 110-115 My. The Rb-Sr data also reveal for the Ambrosia Lake-Smith Lake areas Precambrian source materials and Permian--Triassic source material; both of which provided U to the Grants mineral belt. The trace element suites from ore zones, oxidized rocks near ore, and both oxidized and reduced rocks removed from ore suggest that the upper units of the Morrison Formation (i.e., Brushy Basin Member) contained volcanic detritus which provided not only U, V, Mo, Se, As but other trace elements which are not usually transported far from their sites of origin; viz. rare earth elements, Th, Ta, Sb.Thus a polygenetic model similar to the rolltype mechanisms but involving more complex sedimentary control and U from several source areas is compatible with the trend and other ore in the Grants mineral belt

  13. Radionuclide uptake by various plants growing on uranium tailings, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    Detectable levels of Ra-226 (0.2 to 27.6 pCi/g), Ra-223 (<= 0.1 to 4.3 pCi/g) and Pb-210 (0.6 to 6.9 pCi/g) were measured in various species of vegetation growing on various uranium tailings in Elliot Lake. On the other hand levels of Th-232 (<= 0.1 pCi/g), Th-230 (<= 0.1 pCi/g) were near detection limits in the same vegetation samples. In tailings substrates, all radionuclides investigated were detectable: Ra-226 (8.8 to 552 pCi/g), Ra-223 (3.1 to 213 pCi/g), Pb-210 (5.4 to 441 pCi/g), Th-232 (1.6 to 15.4 pCi/g), Th-230 (4.9 to 62 pCi/g) and Th-228 (1.3 to 38 pCi/g). Lower Th than Ra and Pb levels in tailings substrate were believed to be the cause for the relatively lower Th levels measured in vegetation when compared to Ra and Pb concentrations. No correlation was observed between the level of a given radionuclide in tailings and in the vegetation growing on that tailings

  14. Determination of radon flux rates in a uranium mine (Cluff Lake, Saskatchewan)

    International Nuclear Information System (INIS)

    The Atomic Energy Control Board contracted SENES Consultants Limited to design and implement a field program at Amok Limited's Cluff Lake uranium mine, with the overall objective of obtaining reliable radon flux data applicable for use in the VENTRAD computer model. The VENTRAD model was developed to model underground mine ventilation systems. To avoid the uncertainties inherent in localized flux measurements made on small surfaces, radon flux measurements were determined through measurement of incremental changes in the concentration of radon between the incoming and outgoing air in selected areas of the underground workings. The locations were selected throughout the mine in both ore and sterile rock. Average radon flux rates measured during three field campaigns were as follows: sterile rock decline 4 pCi/m2.second; sterile rock mainway 25 pCi/m2.second; worked-out stope 100 pCi/m2.second; active work stope 240 pCi/m2.second; and work face 14,000 pCi/m2.second. Data collected during the three field programs were used to validate the VENTRAD computer model. The results of the validation exercise suggest close agreement between predicted and measured air flow rates and radon concentrations were overestimated for areas immediately impacted by auxiliary ventilation fans and ore transfer mill holes which connect the ore extraction and haulage levels of the mine

  15. The behavior of uranium and manganese under the diagenesis of carbonate sediments in small lakes of the Baikal region

    Science.gov (United States)

    Vosel, Yu. S.; Strakhovenko, V. D.; Makarova, I. V.; Vosel, S. V.

    2015-05-01

    This report considers the experimental studies of diagenetic processes involving uranium and manganese in lacustrine sediments, especially to prove the possibility of formation of UO2 + x reduced phases. Comparative research was performed for two lakes of different depths, hydrological conditions, mineralization, and chemical composition of waters. The layerwise successive leaching of sediments was carried out, with subsequent measurement of the contents of the uranium-238 and -234 isotopes in chemogenic fractions of the sediment. By means of ESR and successive leaching, the profiles of the manganese oxide and hydroxide content over the section were obtained. The performed studies confirmed the hypothesis of the formation of UO2 + x reduced phases in sediments. The sediments of the deeper freshwater Alyaty Lake are characterized by an increase in the content of the UO2 + x reduced phases and a decrease of manganese oxides and hydroxides downwards and upwards through the section, respectively. This conforms quite well to the behavior of these elements in oceanic sediments. The shallow saline Tsagan-Tyrm Lake is characterized by the reverse situation: the bulk of the UO2 + x reduced phase occurs in upper layers where, in turn, the oxide phases of manganese are simply absent. This is caused by different reductive conditions in the sediments.

  16. contaminant migration in a sand aquifer near an inactive uranium tailings impoundment, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    An investigation of the movement of contaminated groundwater from inactive uranium tailings through a sand aquifer is being conducted at the Nordic Main tailings impoundment near Elliot Lake, Ontario. During 1979 and 1980, multilevel bundle-type piezometers were installed at several locations around the edge of the tailings impoundment. Chemical analysis of water samples from the bundle piezometers indicate that a major contaminant plume extends outward through a sand aquifer from the southeastern part of the Nordic Main impoundment dam. In the vincinity of the contaminant plume, the sand aquifer varies in thickness from about 9 to 15 m. The plume has two distinct segments, referred to as the inner core and the outer zone. The inner core, which has a pH of 4.3-5.0 and extends about 15 m from the foot of the tailings dam, contains several grams per litre of iron and sulfate, and tens of pCi/L of 226Ra and 210Pb. Water levels in piezometers within the inner core show that groundwater is moving horizontally, away from the tailings impoundment, with a velocity of up to several hundred metres per year. The outer zone, which extends a few hundred metres downgradient from the dam, is characterized by hundreds to thousands of milligrams per litre of iron and sulfate, less than 15pCi/L of 226Ra, and a pH greater than 5.7. Comparison of 1979 and 1980 data shows that the front of the inner core is advancing a few metres per year, which is less than a few percent of the groundwater velocity. This retardation of movement of the inner core is caused by neutralization of the acidic water as a result of dissolution of calcium carbonate in the sand. With the rise in pH, precipitation of iron carbonate and possibly some iron hydroxide occurs and the contaminants of main concern such as 226Ra, 210Pb, and uranium are removed from solution by adsorption or coprecipitation

  17. Clay mineralogy and isotope geochemistry of the alteration halo at the Cigar Lake uranium deposit

    International Nuclear Information System (INIS)

    The clay-size fraction of the alteration halo associated with the Cigar Lake uranium deposit consists of illite with subordinate kaolinite, sudoite (Al-chlorite), Fe-chlorite, hematite, and traces of an illite-chlorite mixed-layer mineral. The Kuebler Index of illite crystallinity ranges from 2.0 to 6.7; the most-altered samples average 4.0. These data indicate that high-grade diagenetic to anchizonal conditions have been reached within the alteration halo. Intensity ratios of the 002 and 001 illite reflections (I(002)/I(001)) are generally greater than 0.4, the phengite-muscovite boundary, reflecting aluminum-rich illites; illite composition approaches hydromuscovite. K-Ar dates for illite-rich samples, from 1255 to 1148 Ma, could reflect variable resetting of the K-Ar system during hydrothermal fluid circulation after or during main-stage ore formation. The sudoite-illite assemblage from an altered basement sample yield a date of 815 Ma, unlike the clay-rich ore sample which contains no radiogenic argon. The younger date of the basement sample and the lack of radiogenic 40Ar in the ore sample may result from alteration. Average δD and δ18O values for illite-rich samples are -82 and +10, respectively. Samples that contain sudoite are enriched in D, but the ore sample containing Fe-chlorite is depleted in D and 18O relative to the illite-rich samples. 72 refs., 12 figs., 6 tabs

  18. Enumeration and characterization of microorganisms associated with the uranium ore deposit at Cigar Lake, Canada. Informal report

    International Nuclear Information System (INIS)

    The high-grade uranium deposit at Cigar Lake, Canada, is being investigated as a natural analog for the disposal of nuclear fuel waste. Geochemical aspects of the site have been studied in detail, but the microbial ecology has not been fully investigated. Microbial populations in an ore sample and in groundwater samples from the vicinity of the ore zone were examined to determine their effect on uranium mobility. Counts of the total number of bacteria and of respiring bacteria were obtained by direct microscopy, and the viable aerobic and anaerobic bacteria were assessed as colony forming units (CFUs) by the dilution plating technique. In addition, the population distribution of denitrifiers, fermenters, iron- and sulfur-oxidizers, iron- and sulfate-reducers, and methanogens was determined by the most probable number (MPN) technique

  19. Mount Taylor uranium deposit, San Mateo, New Mexico

    International Nuclear Information System (INIS)

    The Mount Taylor uranium deposit is located at the extreme eastern end of the Ambrosia Lake District in the Grants Mineral Belt of New Mexico. This deposit is a sandstone-type uranium deposit which was formed by lateral secretion. This study has demonstrated the existence of a clay mineral alteration pattern around the Mount Taylor deposit. Montmorillonite is the dominant clay downdip of the deposit. As the deposit is approached from the downdip side, montmorillonite gives way to chlorite in edge-to-face arrangement. In the ore body, chlorite as rosettes is the dominant clay mineral. Updip of the ore zone the dominant clay mineral is kaolinite. A positive correlation has been demonstrated between uranium and organic materials as determined by LOI in the ore zones of the deposit. Organic geochemical leaching studies have also shown organic acids to be effective uranium leaching agents; and traces of them have been found in SEM photomicrographs. This suggests that organic acids or short-chain functional groups may have been transporting agents for the uranium. Adsorption of these polar molecules to clays to form the ore body would explain the lack of uranium-bearing minerals. Several of the trace elements studied may be useful pathfinders: Manganese, ytterbium, and cerium show positive downdip anomalies; sodium and samarium show negative updip anomalies; and zinc and uranium show positive updip anomalies. Additional work is needed to verify theusefulness of each of these. The presence of a redox interface in a deposit which is 3000 to 5000 feet deep suggests that the oxidation phenomena responsible for ore remobilization may be a relic Morrison feature

  20. Uranium

    International Nuclear Information System (INIS)

    The uranium production industry is well into its third recession during the nuclear era (since 1945). Exploration is drastically curtailed, and many staffs are being reduced. Historical market price production trends are discussed. A total of 3.07 million acres of land was acquired for exploration; drastic decrease. Surface drilling footage was reduced sharply; an estimated 250 drill rigs were used by the uranium industry during 1980. Land acquisition costs increased 8%. The domestic reserve changes are detailed by cause: exploration, re-evaluation, or production. Two significant discoveries of deposits were made in Mohave County, Arizona. Uranium production during 1980 was 21,850 short tons U3O8; an increase of 17% from 1979. Domestic and foreign exploration highlights were given. Major producing areas for the US are San Juan basin, Wyoming basins, Texas coastal plain, Paradox basin, northeastern Washington, Henry Mountains, Utah, central Colorado, and the McDermitt caldera in Nevada and Oregon. 3 figures, 8 tables

  1. Uranium Mill Tailings Remedial Action Project 1994 environmental report

    International Nuclear Information System (INIS)

    This annual report documents the Uranium Mill Tailings Remedial Action (UMTRA) Project environmental monitoring and protection program. The UMTRA Project routinely monitors radiation, radioactive residual materials, and hazardous constituents at associated former uranium tailings processing sites and disposal sites. At the end of 1994, surface remedial action was complete at 14 of the 24 designated UMTRA Project processing sites: Canonsburg, Pennsylvania; Durango, Colorado; Grand Junction, Colorado; Green River Utah, Lakeview, Oregon; Lowman, Idaho; Mexican Hat, Utah; Riverton, Wyoming; Salt Lake City, Utah; Falls City, Texas; Shiprock, New Mexico; Spook, Wyoming, Tuba City, Arizona; and Monument Valley, Arizona. Surface remedial action was ongoing at 5 sites: Ambrosia Lake, New Mexico; Naturita, Colorado; Gunnison, Colorado; and Rifle, Colorado (2 sites). Remedial action has not begun at the 5 remaining UMTRA Project sites that are in the planning stage. Belfield and Bowman, North Dakota; Maybell, Colorado; and Slick Rock, Colorado (2 sites). The ground water compliance phase of the UMTRA Project started in 1991. Because the UMTRA Project sites are.' different stages of remedial action, the breadth of the UMTRA environmental protection program differs from site to site. In general, sites actively undergoing surface remedial action have the most comprehensive environmental programs for sampling media. At sites where surface remedial action is complete and at sites where remedial action has not yet begun, the environmental program consists primarily of surface water and ground water monitoring to support site characterization, baseline risk assessments, or disposal site performance assessments

  2. The centuries-old and thousand- year oscillations of uranium distribution in the Lake Baikal sediments, according to the neutron-fission (n,f)-autoradiography

    Science.gov (United States)

    Kirichenko, Ivan; Zhmodik, Sergey; Belyanin, Dmitriy; Khlistov, Oleg

    2016-04-01

    The trace elements local distribution data, particularly (U, P, Br, Mo, BiSi et. all) in a lake and oceans bottom sediments reflects the conditions of those sediments formation, and correlates with changes in paleoclimatic conditions. In papers [Colman et all, 1995; Goldberg et all, 2000, etc.] established that the concentrations of some elements contained in the bottom sediments of Lake Baikal, in particular BiSi, Sr / Ba, Sr / Rb, Ti, U et al., reflect changes in insolation caused by periodic oscillations parameters Earth's orbit (Milankovitch cycles). At the same time, a bottom sediments of the largest continental lake (Lake Baikal), can keep a record of changes less periodicity. Our research focuses on the study of the spatial distribution of uranium with high resolution in the bottom sediments of Lake Baikal. The purpose of this research is determination the centure-old and thousand- old year oscillations in the concentration of uranium in the sediments of Lake Baikal. Fragments of the lake sediment columns taken from the axial part of the Akademicheskiy Ridge in Lake Baikal (stations coordinates St -8 (53 32'15"N 107 56'25"E); - and St11 - (53 33'51"N 108 00'05"E) were studied using complex of local analysis methods, such as: n, f - and n, β-autoradiography, SEM. The distributions of uranium and phosphorus in the authigenic component of sediments along the whole columns length (with the resolution of 10 micron which corresponds to the time resolution of about six months) have been studied by the autoradiography method. Statistical data analysis (Fourier and wavelet analysis) were used for detection oscillations in the uranium concentration Three main different factors of concentrators were established for uranium and phosphorus in the sediments of the Academic mountain range:1) sedimentation, 2) nutrient,3) diagenetic. The periodicity (range from 100 to 1,000 years), in the distribution of authigenic uranium in the sediment column were identified by

  3. Distribution of Invasive Weed Ambrosia artemisiifolia L. in Croatia

    Directory of Open Access Journals (Sweden)

    Natalija Galzina

    2010-06-01

    Full Text Available Ambrosia artemisiifolia L. is an invasive alien plant in Europe that has been the subject of research of many scientific disciplines, particularly in last twenty years. In addition to being known as a noxious weed, it came into the public interest as a source of very strong allergenic pollen that causes allergic responses in 10% of the Croatian population, a figure similar to that of other European countries. The genus Ambrosia consists of about 40 species but in Europe just five of them are present. The most widespread is Ambrosia artemisiifolia L. It is present normally in row crops, particularly in sunflower (Helianthus annuus L. fields. Furthermore, its presence is noticed along communication lines, in urban, industrial and building areas, and other non-agricultural areas. Distribution monitoring of Ambrosia artemisiifolia L. was conducted during three years, from 2004 to 2006, by recording its presence or absence in settlements of districts in the 21 counties of Croatia. Inland parts of Croatia are highly infested with Ambrosia artemisiifolia L. while in the coastal area it is mainly concentrated on bands along communication lines. In this area we observed individual (solitary plants. Systematic and well organized monitoring of the Ambrosia artemisiifolia L. spread and distribution in the coastal parts of Croatia would reduce its progression to the more southern parts and the Croatian islands.

  4. A combined chemical, isotopic and microstructural study of pyrite from roll-front uranium deposits, Lake Eyre Basin, South Australia

    Science.gov (United States)

    Ingham, Edwina S.; Cook, Nigel J.; Cliff, John; Ciobanu, Cristiana L.; Huddleston, Adam

    2014-01-01

    The common sulfide mineral pyrite is abundant throughout sedimentary uranium systems at Pepegoona, Pepegoona West and Pannikan, Lake Eyre Basin, South Australia. Combined chemical, isotopic and microstructural analysis of pyrite indicates variation in fluid composition, sulfur source and precipitation conditions during a protracted mineralization event. The results show the significant role played by pyrite as a metal scavenger and monitor of fluid changes in low-temperature hydrothermal systems. In-situ micrometer-scale sulfur isotope analyses of pyrite demonstrated broad-scale isotopic heterogeneity (δ34S = -43.9 to +32.4‰VCDT), indicative of complex, multi-faceted pyrite evolution, and sulfur derived from more than a single source. Preserved textures support this assertion and indicate a genetic model involving more than one phase of pyrite formation. Authigenic pyrite underwent prolonged evolution and recrystallization, evidenced by a genetic relationship between archetypal framboidal aggregates and pyrite euhedra. Secondary hydrothermal pyrite commonly displays hyper-enrichment of several trace elements (Mn, Co, Ni, As, Se, Mo, Sb, W and Tl) in ore-bearing horizons. Hydrothermal fluids of magmatic and meteoric origins supplied metals to the system but the geochemical signature of pyrite suggests a dominantly granitic source and also the influence of mafic rock types. Irregular variation in δ34S, coupled with oscillatory trace element zonation in secondary pyrite, is interpreted in terms of continuous variations in fluid composition and cycles of diagenetic recrystallization. A late-stage oxidizing fluid may have mobilized selenium from pre-existing pyrite. Subsequent restoration of reduced conditions within the aquifer caused ongoing pyrite re-crystallization and precipitation of selenium as native selenium. These results provide the first qualitative constraints on the formation mechanisms of the uranium deposits at Beverley North. Insights into

  5. Distribution and genesis of sedimentary uranium near Curnamona, Lake Frome region, South Australia

    International Nuclear Information System (INIS)

    Exploration in the Curnamona area of South Australia has delineated two lower Tertiary paleochannels incised into Middle Cambrian red beds of the Arrowie basin. One of these, the Billeroo channel, contains pervasive uranium mineralization in sediments deposited in a braided stream draining northward off the Proterozoic Willyama Complex. One potentially economic uranium deposit, the Gould's Dam deposit, and several other significant uranium occurrences, have been located within the sands of the channel section. Detailed evaluation of the distribution of mineralization within the channel sands has revealed a clear relation among uranium mineralization, geochemical zonation, and the sedimentologic features of the host sands. A genetic model is proposed in which a uraniferous geochemical cell migrated down gradient through each sand of the channel section. The resulting partly-discrete cells were preferentially guided through areas of high transmissivity, corresponding to the main channels of the braided stream. Under favorable conditions uranium was deposited at the redox interface of the geochemical cells developed along the edge of these channels adjacent to and within the less permeable, more reducing longitudinal-bar deposits of the braided stream. The geometry and geochemistry of the resulting mineralization are very similar to that of roll-front uranium deposits in Wyoming

  6. Uranium activity ratio in water and fish from pit lakes in Kurday, Kazakhstan and Taboshar, Tajikistan

    International Nuclear Information System (INIS)

    Kurday in Kazhakstan and Taboshar in Tajikistan were U mining sites operated during the 1950s and 1960s as part of the USSR nuclear weapon program. Today, they represent sources of potential U contamination of the environment. Within both mining sites, open pits from which U ore was extracted have been filled with water due to ground water inflow and precipitation. These artificial pit lakes contain fish consumed occasionally by the local people, and wild and domestic animals are using the water for drinking purposes. To assess the potential impact from U in these pit lakes, field work was performed in 2006 in Kurday and 2006 and 2008 in Taboshar. Results show that the U concentration in the lake waters were relatively high, about 1 mg/L in Kurday Pit Lake and about 3 mg/L in Taboshar Pit Lake. The influence of U-bearing materials on the lakes and downstream waters were investigated by measuring the U concentration and the 234U/238U activity ratios. In both Kurday and Taboshar, the ratios increased distinctively from about 1 at the pit lakes to >1.5 far downstream the lakes. The concentrations of 238U in gill, liver, muscle and bones in fish from the pit lakes were much higher than in the reference fish. Peak concentration of U was seen in bones (13 mg/kg w.w.), kidney (9.1 mg/kg w.w.) and gills (8.9 mg/kg w.w.) from Cyprinus auratus caught in the Taboshar Pit Lake. Bioconcentration factors (BCF) calculated for organs from fish caught in the Taboshar Pit Lake, with the same tendency seen in the Kurday Pit Lake, showed that U accumulates most in bone (BCF = 4.8 L/kg w.w.), gills (BCF = 3.6 L/kg w.w.), kidney (BCF = 3.6 L/kg w.w.), and liver (BCF = 2.5 L/kg w.w.), while least was accumulated in the muscle (BCF = 0.12 L/kg w.w.)

  7. New Sesquiterpenoids from Ambrosia artemisiifolia L.

    Directory of Open Access Journals (Sweden)

    Wenbing Ding

    2015-03-01

    Full Text Available A new pseudoguaianolide 1 and two new guaiane-type sesquiterpene glucosides 2 and 3, were isolated from the aerial parts of Ambrosia artemisiifolia L together with two known sesquiterpene dilactones 4 and 5. The new compounds were determined on the basis of spectroscopic and chemical methods to be 3β-acetoxy-4β-hydroxy-1α,7α, 10β,11αH-pseudoguaia-12,8β-olide (1, 1β,7β,9β,10β,13αH-guaia-4(5-en-12,6β-olide 9-O-β-d-glucoside (2 and 4β-hydroxy-1α,5α,7α,9αH-guaia-10(14,11(13-dien-12-acid 9-O-β-d-glucoside (3. The isolated compounds were evaluated for cytotoxicity against human promyelocytic leukemia HL-60 cell lines in vitro, but were all inactive.

  8. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Salt Lake City, Utah. Revision 1

    International Nuclear Information System (INIS)

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the first is the Surface Project, and the second is the Ground Water Project. For the UMTRA Project site known as the Vitro site, near Salt Lake City, Utah, Surface Project cleanup occurred from 1985 to 1987. The UMTRA Project's second phase, the Ground Water Project, evaluates the nature and extent of ground water contamination resulting from uranium processing and determines a strategy for ground water compliance with the Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. A risk assessment is the process of describing a source of contamination and showing how that contamination may reach people and the environment. The amount of contamination people or the environment may be exposed to is calculated and used to characterize the possible health or environmental effects that may result from this exposure. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Vitro site. The results of this report and further site characterization of the Vitro site will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards

  9. Baseline risk assessment of ground water contamination at the uranium mill tailings site near Salt Lake City, Utah. Revision 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-09-01

    The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the first is the Surface Project, and the second is the Ground Water Project. For the UMTRA Project site known as the Vitro site, near Salt Lake City, Utah, Surface Project cleanup occurred from 1985 to 1987. The UMTRA Project`s second phase, the Ground Water Project, evaluates the nature and extent of ground water contamination resulting from uranium processing and determines a strategy for ground water compliance with the Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. A risk assessment is the process of describing a source of contamination and showing how that contamination may reach people and the environment. The amount of contamination people or the environment may be exposed to is calculated and used to characterize the possible health or environmental effects that may result from this exposure. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Vitro site. The results of this report and further site characterization of the Vitro site will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards.

  10. Elliot Lake study: factors affecting the uranium mine working environment prior to the introduction of current ventilation practices

    International Nuclear Information System (INIS)

    A study was carried out to assist in the retrospective assessment of the underground environment that existed in the Elliot Lake uranium mines in the late 1950's and early 1960's. The environmental conditions and work practices of the late 1950's were established by a combination of literature review and interviews with veteran miners. The practices of the 1950's were imitated in a pilot raise, and extensive measurements of the radiation environment were made. Realistic values of radon and thoron daughter production and removal rates were obtained. The computer model demonstrated that it could reproduce all the observed features of the radiation environment given realistic input parameters. A realistic time and space dependent computer model was used to calculate and compare the average expsoure of the miner in the 1950's with the exposure that would be expected from contemporary measurements, and with that of the miner today. The calculated exposure is about half of that expected from contemporary measurements, which gives assurance that previous exposures for pilot raise miners were not underestimated. Relative to today's miner, the average exposure of the typical raise miner of the 1950's is estimated as three times higher for radon daughters, equal for thoron daughters, equal for exposure to gamma radiation, but much higher for uranium and quartz dust

  11. Phase II, Title I engineering assessment of inactive uranium mill tailings, Vitro Site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    As a result of a preliminary survey (Phase I) completed in October 1974, ERDA identified some 18 sites in the states of Arizona, Colorado, Idaho, New Mexico, Oregon, Texas, Utah, and Wyoming for which practicable remedial measures are to be evaluated. Most of these mills produced by far the greatest part of their output of uranium under contracts with the U.S. Atomic Energy Commission during the period 1947 through 1970. After operations ceased some companies made no attempt to stabilize the tailings, while others did so with varying degrees of success. In recent years there has developed a growing concern about the possible adverse effects to the general public from long-term exposure to low-level sources of radiation. Much attention has been focused on the growing accumulation of wastes containing radium and thorium at uranium ore processing mills in the western United States. To date, the studies of radiation levels in the vicinity of these sites have been limited in scope. The factual data available were insufficient to permit an assessment of risk to people with any degree of confidence in the conclusions reached. In addition, information on practicable measures to reduce radiation exposures and estimates of their projected costs are completely lacking. The purpose of this study is to develop the necessary information to provide a basis for decision making for appropriate remedial action. This report is the first of a series to be made on inactive uranium mill sites in the western United States. The site of the former Vitro Chemical Company mill in Salt Lake City, Utah, was selected for the first study since it includes a large unstabilized mill tailings pile, is located in a major metropolitan area, and involves most of the problems expected to be encountered at other locations. The effort required to complete the engineering analysis of the remaining sites and to prepare reports is expected to require about a year

  12. Licensing of in situ leach recovery operations for the Crownpoint and Church Rock uranium deposits, New Mexico: A case study

    International Nuclear Information System (INIS)

    Licensing of in situ leach recovery operations in New Mexico, adjacent to the Navajo Indian Reservation, required significant effort on the part of Uranium Resources, Inc. and the subsidiary, Hydro Resources Inc., since the original application in 1988. On January 5, 1998, the U.S. Nuclear Regulatory Commission issued the license to operate following a lengthy Environmental Impact Statement process jointly managed by the U.S. Nuclear Regulatory Commission, the U.S. Bureau of Indian Affairs, and the U.S. Bureau of Land Management. The principal stakeholders include the State of New Mexico, the Navajo Nation and a number of citizen groups. The U.S. Environmental Protection Agency reviewed the Environmental Impact Statement. Since licensing, Hydro Resources Inc. overcame legal challenges to the source material license from groups opposed to uranium development and obtained the necessary water rights from the State of New Mexico on October 19, 1999. On January 19, 2000, the Navajo Nation lifted its 1983 moratorium on uranium mining for uranium in situ leach recovery. Since then, Hydro Resources Inc.'s focus has changed to preparing the Restoration Action Plan for Church Rock Section 17 site, Crownpoint Unit One, and Crownpoint. The U.S. Nuclear Regulatory Commission has since approved these plans. The Grants Uranium Region is located in northwestern New Mexico and is part of the Colorado Plateau physiographic province. The Jurassic Westwater Canyon Member of the Morrison Formation in the San Juan Basin hosts the uranium. The Crownpoint and Church Rock ore trends are monometallic, regional redox-controlled, roll-front type uranium deposits and occur as stacked roll-fronts. Other uranium deposits in the Grants Uranium Region include humate-type sandstone deposits including the Ambrosia Lakes District. Total low-cost Reasonably Assured Resources (RAR) for properties controlled by Hydro Resources Inc. includes 38,462 Tonnes U (100 million lbs U3O8). This paper reviews the

  13. High-precision uranium-series dating of lacustrine carbon-ates from Daihai Lake

    Institute of Scientific and Technical Information of China (English)

    2001-01-01

    Ages of small aragonite samples retrieved from sediments from the Daihai Lake are determined by using the Thermal Ionization Mass Spectrometry (TIMS) technique. The ages of the samples range from (8740±601) to (10446±489) a, with a precision of 2%-3% for non-corrected dating ages and 4.7%-9.8% for corrected ages respectively, and are consistent within the deviation range. At about 10.5 ka BP, the grain-size of the sediments coarsens sharply, the frequency curves of grain-size distribution show coarse grain dominated single-double kurtosis, indicating cooling, de-creased hydrodynamic conditions and increased wind influ-ence procedure. This is in good agreement with previous results obtained from the Daihai Lake, which suggests that the climate was cold and the lake surface was shrinking. The TIMS ages of the sediments are therefore believed to be credible.

  14. Lake

    Science.gov (United States)

    Wien, Carol Anne

    2008-01-01

    The lake is blue black and deep. It is a glaciated finger lake, clawed out of rock when ice retracted across Nova Scotia in a northerly direction during the last ice age. The lake is narrow, a little over a mile long, and deep, 90 to 190 feet in places according to local lore, off the charts in others. The author loves to swim there, with a sense…

  15. Biological processes for concentrating trace elements from uranium mine waters. Technical completion report

    International Nuclear Information System (INIS)

    Waste water from uranium mines in the Ambrosia Lake district near Grants, New Mexico, USA, contains uranium, selenium, radium and molybdenum. The Kerr-McGee Corporation has a novel treatment process for waters from two mines to reduce the concentrations of the trace contaminants. Particulates are settled by ponding, and the waters are passed through an ion exchange resin to remove uranium; barium chloride is added to precipitate sulfate and radium from the mine waters. The mine waters are subsequently passed through three consecutive algae ponds prior to discharge. Water, sediment and biological samples were collected over a 4-year period and analyzed to assess the role of biological agents in removal of inorganic trace contaminants from the mine waters. Some of the conclusions derived from this study are: (1) The concentrations of soluble uranium, selenium and molybdenum were not diminished in the mine waters by passage through the series of impoundments which constituted the mine water treatment facility. Uranium concentrations were reduced but this was due to passage of the water through an ion exchange column. (2) The particulate concentrations of the mine water were reduced at least ten-fold by passage of the waters through the impoundments. (3) The sediments were anoxic and enriched in uranium, molybdenum and selenium. The deposition of particulates and the formation of insoluble compounds were proposed as mechanisms for sediment enrichment. (4) The predominant algae of the treatment ponds were the filamentous Spirogyra and Oscillatoria, and the benthic alga, Chara. (5) Adsorptive processes resulted in the accumulation of metals in the algae cells. (6) Stimulation of sulfate reduction by the bacteria resulted in retention of molybdenum, selenium, and uranium in sediments. 1 figure, 16 tables

  16. Mineralogical variations across Mariano Lake roll-type uranium deposits, McKinley County

    International Nuclear Information System (INIS)

    Mineralogy of core samples from the Mariano orebody was determined. The data obtained were used to develop exploration tools for roll-type uranium deposits. Preliminary interpretations of the physical and chemical conditions of ore deposition were made on the basis of paragenetic relationships. The host sandstones occur between the bentonitic rock units and contain scattered intercalations of detrital montmorillonitic material in the form of clay galls, stringers, and lenses derived from these bentonites. Authigenic clay minerals identified in the host rocks include cellular montmorillonite, platy chlorite, and pseudohexagonal books of kaolinite. The cellular montmorillonite is concentrated in the oxidized zone and appears to have formed prior to ore deposition. Authigenic chlorite is most abundant in the ore zone and has formed at the expense of cellular montmorillonite; its formation is interpreted as being related to the ore-forming processes. Kaolinite in sandstones is the last clay mineral to form and is enriched in the reduced zone. Calcite, considered typical of such deposits, is not found in this orebody. Iron-titanium oxides and their alteration products are the most abundant heavy-mineral species in the host rocks. In addition to anatase and rutile, the alteration products include hematite in the oxidized zone and pyrite in the ore and reduced zones. Carbonaceous material introudced later into the potential ore zone appears to have been responsible for the decomposition of Fe-Ti oxides and the formation of pyrite. The paragenetic relationship indicates oxidation of pyrite by mineralizing solutions, resulting in reduction and subsequent deposition of uranium. The positive correlation between organic carbon and uranium suggests that carbonaceous material also acted as a reductant for uranium

  17. Business Plan Analysis of a New Reverse Osmosis Plant at a Uranium Mine, the Rabbit Lake Operation-Eagle Point Mine

    OpenAIRE

    Khosravinejad, Mehran

    2011-01-01

    This thesis provides a prefeasibility justification for a new Reverse Osmosis Water Treatment Plant at Cameco’s Rabbit Lake operation. The economics of the proposed project are discussed in detail including an in-depth explanation of the uranium industry, required capital investment, and expected gains. As well, the potential environmental and social effects of constructing the reverse osmosis facility and extending the life of the Eagle Point mine are examined. After all potential impacts of...

  18. Phylogeny of ambrosia beetle symbionts in the genus Raffaelea.

    Science.gov (United States)

    Dreaden, Tyler J; Davis, John M; de Beer, Z Wilhelm; Ploetz, Randy C; Soltis, Pamela S; Wingfield, Michael J; Smith, Jason A

    2014-12-01

    The genus Raffaelea was established in 1965 when the type species, Raffaelea ambrosia, a symbiont of Platypus ambrosia beetles was described. Since then, many additional ambrosia beetle symbionts have been added to the genus, including the important tree pathogens Raffaelea quercivora, Raffaelea quercus-mongolicae, and Raffaelea lauricola, causal agents of Japanese and Korean oak wilt and laurel wilt, respectively. The discovery of new and the dispersal of described species of Raffaelea to new areas, where they can become invasive, presents challenges for diagnosticians as well as plant protection and quarantine efforts. In this paper, we present the first comprehensive multigene phylogenetic analysis of Raffaelea. As it is currently defined, the genus was found to not be monophyletic. On the basis of this work, Raffaelea sensu stricto is defined and the affinities of undescribed isolates are considered. PMID:25457944

  19. Development and test of models in the natural analogue studies of the Cigar Lake uranium deposit

    International Nuclear Information System (INIS)

    In the model of steady-state near-field mass transport, the model concepts are essentially the same as those in the models developed for a nuclear waste repository. The validity of the model is tested against known helium release. The models shows that the release of Uranium is negligibly low, the release of sulfate is roughly balanced by the release of dissolved hydrogen, indicating possible water radiolysis. The release of radionuclides is in agreement with field observations. In the model of radiation energy deposition, the issue of water radiolysis is addressed directly by calculating the radiation energy deposited in the pore water in the ore body. In the test of the models of coupled solute transport with geochemical reactions, the observed hematisation in the clay halo adjacent to the ore is simulated. The model results show that, at a certain rate of oxidant production, hematite can possibly precipitate in the clay adjacent to the ore body, as observed. The model results also reveal a threshold of oxidant production rate for hematisation. In general, the three models are capable of predicting the most prominent features observed in the deposit. All models point to a certain extent of water radiolysis in the ore body. In addition, the existence of a negligibly permeable clay halo and the presence of reducing minerals like pyrite in the ore and nearby are of vital importance for the preservation of the Uranium ore. 107 refs, 7 figs, 5 tabs

  20. Uranium-bearing and associated minerals in their geochemical and sedimentological context, Elliot Lake, Ontario

    International Nuclear Information System (INIS)

    The depositional energy environment of the Rio Algom-Denison ore reef was investigated on a regional scale using several parameters including pebble size. Regional trends of decreasing pebble size coincide with the regional direction of sediment transport. Pebble size was also used to characterize the depositional energy environment at the sample level. Quartz-pebble size and pyrite-grain size as determined from the same samples have a correlation coefficient of 0.93 which indicates that the coarse granular pyrite is detrital. Bulk chemical analyses of selected elements (U, Th, Pb, Ti, Ce, La, Y and Zr) which were chosen to reflect specific minerals (uraninite, brannerite, monazite and zircon), showed strong correlation with quartz-pebble size of the respective samples. Electron microprobe analyses of uraninite and brannerite are reported. The uraninites have typical pegmatitic compositions. Several types of brannerite are described; the conclusion reached is that although some brannerite may be detrital, most of it formed by adsorption of uranium onto titania collectors. Redistribution of some of the uranium has not changed the placer nature of the ore reef. Genesis of individual minerals (pyrite, uraninite, brannerite, zircon and monazite) is discussed. It is concluded that the mineralogy and its geochemical expression have been controlled by processes of fluvial deposition. As a result of the regional patterns in depositional environment, the ore reef shows a broad mineralogical zoning. Fluctuations in depositional energy have also produced lithologically related mineral zoning on a smaller scale. (author)

  1. Ra-226 concentrations in blueberries Vaccinium angustifolium Ait. near an inactive uranium tailings site in Elliot Lake, Ontario, Canada

    International Nuclear Information System (INIS)

    Ra-226 concentrations were measured in blueberries growing around the Stanrock uranium tailings area near Elliot Lake, Ontario, Canada. Elevated levels of total Ra-226 ranging between 20 to 290 mBq g-1 were observed in samples collected within 500 m from the tailings. Highest levels, approx. 285 mBq g-1, were observed in a sample collected on a tailings spill. For sites located more than 500 m away in the upwind direction, and those situated at distances greater than 1 km downwind from the waste pile, the total Ra-226 concentrations approached background levels which were measured as 2 to 6 mBq g-1. Approximately 17% of the total Ra-226 measured was removable by washing the samples with distilled water. Wind dispersal of the tailings material and its deposition in the form of dust on blueberries was believed to be responsible for the external contamination. Based on the ICRP recommended dose limits for oral intake of Ra-226, it was calculated that approximately 160 kg a-1, 3350 kg a-1 and 47 kg a-1 of washed blueberries from inside and outside the influenced zone, and from the tailings spill site, respectively, would need to be consumed before the individual annual limit for the general public was exceeded. (author)

  2. The effects of phosphorus additions on the sedimentation of contaminants in a uranium mine pit-lake.

    Science.gov (United States)

    Dessouki, Tarik C E; Hudson, Jeff J; Neal, Brian R; Bogard, Matthew J

    2005-08-01

    We investigated the usefulness of phytoplankton for the removal of surface water contaminants. Nine large mesocosms (92.2m(3)) were suspended in the flooded DJX uranium pit at Cluff Lake (Saskatchewan, Canada), and filled with highly contaminated mine water. Each mesocosm was fertilized with a different amount of phosphorus throughout the 35 day experiment to stimulate phytoplankton growth, and to create a range in phosphorus load (g) to examine how contaminants may be affected by different nutrient regimes. Algal growth was rapid in fertilized mesocosms (as demonstrated by chlorophyll a profiles). As phosphorus loads increased there were significant declines (puranium (p=0.065). The surface water concentrations of Ra-226, Mo, and Se showed no relationship to phosphorus load. Contaminant concentrations in sediment traps suspended at the bottom of each mesocosm generally showed the opposite trend to that observed in the surface water, with most contaminants (As, Co, Cu, Mn, Ni, Ra-226, U, and Zn) exhibiting a significant positive relationship (pphytoremediation has the potential to lower many surface water contaminants through the sedimentation of phytoplankton. Based on our results, we estimate that the Saskatchewan Surface Water Quality Objectives (SSWQO) for DJX pit would be met in approximately 45 weeks for Co, 65 weeks for Ni, 15 weeks for U, and 5 weeks for Zn. PMID:15979684

  3. The redbay ambrosia beetle, Xyleborus glabratus: A threat to avocado

    Science.gov (United States)

    Laurel wilt (LW) is a disease caused by Raffaelea sp., a fungal symbiont associated with the recently-introduced redbay ambrosia beetle (RAB), Xyleborus glabratus. Impact of RAB as a vector of the disease to avocado is a threat to avocado production in the U.S. Since 2006, we have a) tested suscepti...

  4. Licensing of in situ leach mining for the Crownpoint and Church Rock uranium deposits, New Mexico

    International Nuclear Information System (INIS)

    the Ambrosia Lake District. Total low-cost Reasonably Assured Resources (RAR) for properties controlled by Hydro Resources Inc. includes 32 730 tonnes U (85 million lbs U3O8). This paper reviews the process of developing and licensing this resource. Hydro Resources, Inc. ('HRI') is a wholly owned subsidiary of Uranium Resources, Inc. (URI) whose role is the operating company for acquisition, permitting (licensing) and developing of the New Mexico properties. The corporation has invested over $20 million in New Mexico since 1986 because the San Juan Basin is the most prolific uranium province in the United States with historical production of over 133,000 tonnes U (347 million lbs U3O8) nearly matching the resources of several of the world class Australian and Canadian deposits

  5. Age and origin of uraninite in the Elliot Lake, Ontario uranium ores

    International Nuclear Information System (INIS)

    There is a strong, positive linear correlation between the 204Pb/206Pb and 207Pb/206Pb ratios and between the 208Pb/206Pb and 207Pb/206Pb ratios in the galenas. The linear relation is interpreted to be the result of ''mixing'' of isotopically distinct Pb produced during two uraninite Pb loss episodes. A complete mixing of crustal Pb and radiogenic Pb released from the associated uraninite at a time T1 formed one end member of the observed trends. The other end member consists of radiogenic Pb released from the uraninite at a later time T2. The galena Pb isotope data indicate that T0, the inital age of the uraninite in the Elliot Lake ores, is 2200-3300 Ma, T1 is less than 2200 Ma, and T2 is less than 1350 Ma. Upper concordia intercepts for most uraninite grains range from 2210 +/- 430 Ma to 2575 +/- 180 Ma; lower concordia intercepts range from 1200 +/- 120 Ma to 1705 +/- 30 Ma. During the first Pb loss episode, at time T1, the centers of most uraninite grains released 45-90% of the accumulated Pb and the outer 5 μm region of the grains released 95-100% of the accumulated Pb. During the second Pb loss episode, at time T2, the grain exteriors released 2-6 times more Pb than the grain centers. A few highly fractured grains appear to have been ''reset'' at T1. The uraninite U-Pb data indicate that T0 greater than or equal to 1700 Ma. Together, the galena Pb isotope and uraninite U-Pb data require that T0 = 2560 +/- 50 Ma, T1, = 1700 +/- 50 Ma, and T2 = 500 +/- 180 Ma, if the 2350 +/- 100 Ma estimated age of deposition of the Huronian rocks (Roscoe, 1973) is correct, the 2560 +/- Ma obtained for the uraninite requires that the uraninite in the Elliot Lake ores is of detrital derivation

  6. Evaluation of the effects of water hardness and chemical pollutants on the zooplankton community in uranium mining lakes with acid mine drainage

    Energy Technology Data Exchange (ETDEWEB)

    Nascimento, H.; Ferrari, C.; Nascimento, M.R. [Brazilian Nulcear Energy Commission/Pocos de Caldas Laboratory (Brazil); Rodgher, S. [Universidade Estadual Paulista Julio de Mesquita Filho/Science and Technology Institute (Brazil); Wisniewski, M.J. [Alfenas Federal University/Limnology Laboratory (Brazil)

    2014-07-01

    Several mining lakes are characterized by the inorganic pollution of its waters, known as acid mine drainage (AMD). The current study was developed in order to evaluate the effect of water hardness and chemical pollutants on the richness and density of the zoo-planktonic community species. A seasonal study was conducted in a uranium mining lake affected by AMD. In environmental conditions of extremely high hardness water values (960.3 to 1284,9 mg/l), zoo-planktonic species have indicated resistance to the combined effect of elevated average concentrations of chemical pollutants such as Al (81.9 mg/l), Zn (15.5 mg/l), Mn (102.8 mg/l), U (2.9 mg/l) and low pH values (average = 3.8). Thus, in environments of extreme chemical conditions, such as a uranium mining lake affected by AMD, the hardness showed to be the best predictor of the zoo-planktonic community richness, indicating a protective effect of ions Ca{sup +2} over in special to Bosminopsis deitersi, Bosmina sp., Keratella americana and K. cochlearis. Document available in abstract form only. (authors)

  7. Evaluation of the effects of water hardness and chemical pollutants on the zooplankton community in uranium mining lakes with acid mine drainage

    International Nuclear Information System (INIS)

    Several mining lakes are characterized by the inorganic pollution of its waters, known as acid mine drainage (AMD). The current study was developed in order to evaluate the effect of water hardness and chemical pollutants on the richness and density of the zoo-planktonic community species. A seasonal study was conducted in a uranium mining lake affected by AMD. In environmental conditions of extremely high hardness water values (960.3 to 1284,9 mg/l), zoo-planktonic species have indicated resistance to the combined effect of elevated average concentrations of chemical pollutants such as Al (81.9 mg/l), Zn (15.5 mg/l), Mn (102.8 mg/l), U (2.9 mg/l) and low pH values (average = 3.8). Thus, in environments of extreme chemical conditions, such as a uranium mining lake affected by AMD, the hardness showed to be the best predictor of the zoo-planktonic community richness, indicating a protective effect of ions Ca+2 over in special to Bosminopsis deitersi, Bosmina sp., Keratella americana and K. cochlearis. Document available in abstract form only. (authors)

  8. Age and origin of uraninite in the Elliot Lake, Ontario uranium ores

    Energy Technology Data Exchange (ETDEWEB)

    Meddaugh, W.S.

    1983-01-01

    There is a strong, positive linear correlation between the /sup 204/Pb//sup 206/Pb and /sup 207/Pb//sup 206/Pb ratios and between the /sup 208/Pb//sup 206/Pb and /sup 207/Pb//sup 206/Pb ratios in the galenas. The linear relation is interpreted to be the result of ''mixing'' of isotopically distinct Pb produced during two uraninite Pb loss episodes. A complete mixing of crustal Pb and radiogenic Pb released from the associated uraninite at a time T/sub 1/ formed one end member of the observed trends. The other end member consists of radiogenic Pb released from the uraninite at a later time T/sub 2/. The galena Pb isotope data indicate that T/sub 0/, the inital age of the uraninite in the Elliot Lake ores, is 2200-3300 Ma, T/sub 1/ is less than 2200 Ma, and T/sub 2/ is less than 1350 Ma. Upper concordia intercepts for most uraninite grains range from 2210 +/- 430 Ma to 2575 +/- 180 Ma; lower concordia intercepts range from 1200 +/- 120 Ma to 1705 +/- 30 Ma. During the first Pb loss episode, at time T/sub 1/, the centers of most uraninite grains released 45-90% of the accumulated Pb and the outer 5 ..mu..m region of the grains released 95-100% of the accumulated Pb. During the second Pb loss episode, at time T/sub 2/, the grain exteriors released 2-6 times more Pb than the grain centers. A few highly fractured grains appear to have been ''reset'' at T/sub 1/. The uraninite U-Pb data indicate that T/sub 0/ greater than or equal to 1700 Ma. Together, the galena Pb isotope and uraninite U-Pb data require that T/sub 0/ = 2560 +/- 50 Ma, T/sub 1/, = 1700 +/- 50 Ma, and T/sub 2/ = 500 +/- 180 Ma, if the 2350 +/- 100 Ma estimated age of deposition of the Huronian rocks (Roscoe, 1973) is correct, the 2560 +/- Ma obtained for the uraninite requires that the uraninite in the Elliot Lake ores is of detrital derivation.

  9. Uranium distribution in waters (wells, taps, rivers and lakes) in Kazakhstan: laying stress on the areas around the Semipalatinsk Test Site, Kazakhstan-Chinese border and uranium mine near Astana

    International Nuclear Information System (INIS)

    Since 1994, we have visited the areas around the Semipalatinsk Test Site, Kazakhstan, every year to evaluate the consequence of the radiation exposure to residents living here. Long-lived radionuclides such as 137Cs and Pu isotopes on land at various areas have been measured together with Pu and U isotopes in human tissues taken at autopsy from residents who died in some settlements and Semipalatinsk city. Uranium in drinking waters has been also measured from a viewpoint of internal dose assessment, because that, among naturally occurring radionuclides, uranium belongs to the most chemical and radiological toxicity of elements for human. Other than radioactive contamination on land related to the nuclear explosion, it is well known that the extraction and processing of earth materials affect exposure to natural radiation of workers and general public when these materials or their industrial products (or by products) contain high level of natural radionuclides. The largest hazard is due to the generation of electrical energy by nuclear reactors (nuclear fuel cycle, including mining and milling of U ore), and the small hazard may be derived from energy production in use of coal, oil and natural gases. Usually, these wastes contain relatively large amount of technologically enhanced naturally occurring radioactive materials (TENORM). These are often stored on the surface and elevate radiation risk for human by increase of dust, food chain and environmental pollution around transportation. Thus, wastes with occurrence of TENORM become also one of the important problems. In this work we provide the baseline data for uranium contents in well and tap waters as drinking sources, streams (rivers) and lakes at some fields as shown below, and an assessment of the potential radiological consequences arising from the consumption of drinking waters in these fields. 1) Some settlements around the Semipalatinsk nuclear test site: well and tap waters (61 samples), and river and

  10. Studies of colloids and suspended particles, Cigar Lake uranium deposit, Saskatchewan, Canada

    International Nuclear Information System (INIS)

    The Cigar Lake U deposit located in the eastern part of the Athabasca Sandstone Basin, consists of a high-grade ore body (up to 55% U) located at a depth of ∼ 430 m. As part of a study to evaluate the analog features of this deposit with respect to a disposal vault for waste nuclear fuel, colloids (1-450 nm) and suspended particles (> 450 nm) in groundwater have been investigated to evaluate their effect on element transport. The results show that particle compositions are similar to the composition of minerals in the sandstones and ore body, suggesting that particles in groundwater are generated by the erosion of fracture-lining minerals and concentrations are affected by the integrity of the host rock. The observed colloid and suspended particle concentrations in the deep groundwaters are too low to have a significant impact on radionuclide migration, provided that radionuclide sorption is reversible. If radionuclides are irreversibly sorbed to particles they cannot sorb to the host rock and their migration can only be evaluated with an understanding of particle mobility. The data for dissolved and particulate U, Th and Ra were used to calculate field-derived distribution ratios (Rd) between particles and groundwater. The wide range of observed Rd values indicates that these radionuclides in particulate form are not in equilibrium with groundwater. U-series isotope data indicated that most of the U and Ra on particles was derived from groundwater. Some particles could have retained their U for as long as 8000 a. The U and Ra contents of particles in the ore and surrounding clay zones are significantly higher than in particles from sandstone, suggesting that the clay has been an effective barrier to particle migration. (author)

  11. Patterns of functional enzyme activity in fungus farming ambrosia beetles

    Directory of Open Access Journals (Sweden)

    De Fine Licht Henrik H

    2012-06-01

    Full Text Available Abstract Introduction In wood-dwelling fungus-farming weevils, the so-called ambrosia beetles (Curculionidae: Scolytinae and Platypodinae, wood in the excavated tunnels is used as a medium for cultivating fungi by the combined action of digging larvae (which create more space for the fungi to grow and of adults sowing and pruning the fungus. The beetles are obligately dependent on the fungus that provides essential vitamins, amino acids and sterols. However, to what extent microbial enzymes support fungus farming in ambrosia beetles is unknown. Here we measure (i 13 plant cell-wall degrading enzymes in the fungus garden microbial consortium of the ambrosia beetle Xyleborinus saxesenii, including its primary fungal symbionts, in three compartments of laboratory maintained nests, at different time points after gallery foundation and (ii four specific enzymes that may be either insect or microbially derived in X. saxesenii adult and larval individuals. Results We discovered that the activity of cellulases in ambrosia fungus gardens is relatively small compared to the activities of other cellulolytic enzymes. Enzyme activity in all compartments of the garden was mainly directed towards hemicellulose carbohydrates such as xylan, glucomannan and callose. Hemicellulolytic enzyme activity within the brood chamber increased with gallery age, whereas irrespective of the age of the gallery, the highest overall enzyme activity were detected in the gallery dump material expelled by the beetles. Interestingly endo-β-1,3(4-glucanase activity capable of callose degradation was identified in whole-body extracts of both larvae and adult X. saxesenii, whereas endo-β-1,4-xylanase activity was exclusively detected in larvae. Conclusion Similar to closely related fungi associated with bark beetles in phloem, the microbial symbionts of ambrosia beetles hardly degrade cellulose. Instead, their enzyme activity is directed mainly towards comparatively more easily

  12. Iron-titanium oxide minerals and magnetic susceptibility anomalies in the Mariano Lake-Lake Valley cores - Constraints on conditions of uranium mineralization in the Morrison Formation, San Juan Basin, New Mexico

    International Nuclear Information System (INIS)

    Petrographic study of the Mariano Lake-Lake Valley cores reveals three distinct zones of postdepositional alteration of detrital Fe-Ti (iron-titanium) oxide minerals in the Westwater Canyon Member of the Upper Jurassic Morrisson Formation. In the uranium-bearing and adjacent portions of the Westwater Canyon, these detrital Fe-Ti oxide minerals have been thoroughly altered by leaching of iron. Stratigraphically lower parts of the Westwater Canyon and the underlying Recapture Member are characterized by preservation of Fe-Ti oxide grains, primarily magnetite and ilmenite, and of hematite, and by an absence or uranium concentrations. Partly destroyed Fe-Ti oxide minerals occupy an interval between the zones of destruction and preservation. Alteration patterns of the Fe-Ti oxide minerals are reflected in bore-hole magnetic susceptibility logs. Magnetic susceptibility response in the upper parts of the Westwater Canyon Member is flat and uniformly <500 μSI units, but at greater depths it fluctuates sharply, from <1,000 to nearly 8,000 μSI units. The boundary between uniformly low and high magnetic susceptibility response corresponds closely to the interval that divides the zone of completely altered from the zone of preserved detrital Fe-Ti oxide minerals. The alteration pattern suggests that solutions responsible for destruction of the Fe-ti oxide minerals originated in the overlying Brushy Basin Member of the Morrison Formation. Previous studies indicate that these solutions were rich in soluble organic matter and perhaps in uranium. Uranium precipitation may have been controlled by a vertically fluctuation interface between organic-rich solutions and geochemically different fluids in which the detrital Fe-Ti oxide minerals were preserved

  13. Uranium deposit research, 1983

    International Nuclear Information System (INIS)

    Research on uranium deposits in Canada, conducted as a prerequisite for assessment of the Estimated Additional Resources of uranium, revealed that (a) the uranium-gold association in rudites of the Huronian Supergroup preferably occurs in the carbon layers; (b) chloritized ore at the Panel mine, Elliot Lake, Ontario, occurs locally in tectonically disturbed areas in the vicinity of diabase dykes; (c) mineralization in the Black Sturgeon Lake area, Ontario, formed from solutions in structural and lithological traps; (d) the Cigar Lake deposit, Saskatchewan, has two phases of mineralization: monomineralic and polymetallic; (e) mineralization of the JEB (Canoxy Ltd.) deposit is similar to that at McClean Lake; (f) the uranium-carbon assemblage was identified in the Claude deposit, Carswell Structure; and (g) the Otish Mountains area, Quebec, should be considered as a significant uranium-polymetallic metallogenic province

  14. Novo besouro-de-ambrosia em guanandi (Calophyllum brasiliense Cambessedes)

    OpenAIRE

    Wagner Calixto de Castro Morais*; Maria Eunice Paula de Souza; Norivaldo dos Anjos

    2011-01-01

    Calophyllum brasiliense, known as Guanandi, is a heliophytic tree, and native to the Americancontinent and show great historic importance in Brazil. There is some information about insectsassociated with this tree species, but very few specific records. The aim of this study was to describethe occurrence and damage of a new Ambrosia beetle attacking Guanandi tree. In order to getthis information, pieces of attacked Guanandi branch were collected and kept under observationfor a period of 39 da...

  15. A rapid in situ method for determining the ages of uranium oxide minerals: Evolution of the Cigar Lake deposit, Athabasca Basin

    International Nuclear Information System (INIS)

    The authors present a rapid and accurate technique for making in situ U-Pb isotopic measurements of uranium oxide minerals that utilizes both electron and ion microprobes. U and Pb concentrations are determined using an electron microprobe, whereas the isotopic composition of Pb for the same area is measured using a high-resolution ion microprobe. The advantages of this approach are: mineral separation and chemical digestion are unnecessary; homogeneous uranium oxide standards, which are difficult to obtain, are not required; and precise and accurate U-Pb ages on ∼10 microm spots can be obtained in a matter of hours. The authors have applied their method to study the distribution of U-Pb ages in complexly intergrown uranium oxides from the unconformity-type Cigar Lake uranium deposit, Saskatchewan, Canada. In situ U-Pb results from early formed uraninite define a well-correlated array on concordia with upper and lower intercepts of 1,467 ± 63 Ma and 443 ± 96 Ma (±1σ), respectively. The 1,467 Ma age is interpreted as the minimum age of mineralization and is consistent with the age of clay-mineral alteration (approximately1477 Ma) and magnetization of diagenetic hematite (1,650 to 1,450 Ma) that is associated with these unconformity-type uranium deposits and early diagenesis of the Athabasca Basin sediments. In situ U-Pb isotopic analysis of uraninite and coffinite can document the Pb*/U heterogeneities that can occur on a scale of 15 to 30 microm, thus providing relatively accurate information regarding the timing of fluid interactions associated with the evolution of these deposits

  16. A Field and Modeling Study of Windblown Particles from a Uranium Mill Tailings Pile

    Energy Technology Data Exchange (ETDEWEB)

    Schwendiman, L. C.; Sehmel, G. A.; Horst, T. W.; Thomas, C. W.; Perkins, R. W.

    1980-06-01

    An extensive field study whose primary objective was to obtain knowledge and understanding of the nature and quantity of windblown particles from uranium mill tailings piles was conducted in the Ambrosia Lake District of New Mexico. The following major field tasks were undertaken: determination of physical, chemical, and radioactivity characteristics of mill tailings particles; an investigation of the nature and quantity of tailings particles in soil in the vicinity of tailings piles; and the determination of the nature and flux of particles being transported by wind as a function of wind speed and height. Results of the field study are presented. Particle size distributions and associated radioactivity were measured. Radioactivity relationships showed uranium daughters in mill tailings to be in essential radioactive equilibrium for the carbonate leach process but thorium-230 tends to be leached into the slurry water for the acid process mill tailings. One objective of the study was to relate windblown particle concentrations, fluxes, and particle sizes to wind speed. Hundreds of samples were taken and analyses were performed, but relationships between wind speed, airborne particle sizes and concentrations were found to be vague and inconclusive. A resuspension, deposition, and transport model was developed and applied using site meteorology. Ground deposition patterns predicted were similar to those found.

  17. Ambrosia airborne pollen concentration modelling and evaluation over Europe

    Science.gov (United States)

    Hamaoui-Laguel, Lynda; Vautard, Robert; Viovy, Nicolas; Khvorostyanov, Dmitry; Colette, Augustin

    2014-05-01

    Native from North America, Ambrosia artemisiifolia L. (Common Ragweed) is an invasive annual weed introduced in Europe in the mid-nineteenth century. It has a very high spreading potential throughout Europe and releases very allergenic pollen leading to health problems for sensitive persons. Because of its health effects, it is necessary to develop modelling tools to be able to forecast ambrosia air pollen concentration and to inform allergy populations of allergenic threshold exceedance. This study is realised within the framework of the ATOPICA project (https://www.atopica.eu/) which is designed to provide first steps in tools and estimations of the fate of allergies in Europe due to changes in climate, land use and air quality. To calculate and predict airborne concentrations of ambrosia pollen, a chain of models has been built. Models have been developed or adapted for simulating the phenology (PMP phonological modelling platform), inter-annual production (ORCHIDEE vegetation model), release and airborne processes (CHIMERE chemical transport model) of ragweed pollen. Airborne pollens follow processes similar to air quality pollutants in CHIMERE with some adaptations. The detailed methodology, formulations and input data will be presented. A set of simulations has been performed to simulate airborne concentrations of pollens over long time periods on a large European domain. Hindcast simulations (2000 - 2012) driven by ERA-Interim re-analyses are designed to best simulate past periods airborne pollens. The modelled pollen concentrations are calibrated with observations and validated against additional observations. Then, 20-year long historical simulations (1986 - 2005) are carried out using calibrated ambrosia density distribution and climate model-driven weather in order to serve as a control simulation for future scenarios. By comparison with multi-annual observed daily pollen counts we have shown that the model captures well the gross features of the pollen

  18. Architecture of Ambrosia psilostachya DC. Individuals in different habitats

    Directory of Open Access Journals (Sweden)

    Maciej Korczyński

    2012-12-01

    Full Text Available Ambrosia psilostachya is a plant of North American origin, well-domesticated in Poland. It covers ruderal habitats and is found in crops and in city green areas. The density of ragweed shoots in the researched areas ranged from 55 to 111 per m2. The production of biomass of this species relates to the production of synanthropic communities and city lawns. The factor limiting the population is cutting which affects mostly the number of shoots per patch, less considerably the state of a single individual. Habitats affected by mechanical factors are the biggest source of pollen causing allergies .

  19. A qualitative evaluation of long-term processes governing the behaviour of uranium mill tailings placed in deep lakes

    International Nuclear Information System (INIS)

    The emplacement of uranim mill tailings in deep lakes may provide an acceptable method of tailings disposal at certain sites in Canada. Disposal in a depositional environment typical of deep lakes appears to offer greater prospects for long-term stability than present methods of land-based management. From the regulatory point of view, it is necessary to know which factors should be taken into account in assessing the acceptability of such an approach. This report examines the environmental variables governing the behaviour of radionuclides and trace elements in the groundwater systems, lake water, and finally in the biosphere over the short and long-term. Physical, chemical and biological factors are each considered. Conclusions are presented in terms of points for and against disposal in deep lakes

  20. Synthesis of surface imprinted nanospheres for selective removal of uranium from simulants of Sambhar salt lake and ground water

    Energy Technology Data Exchange (ETDEWEB)

    Milja, Thazhathuparambil Elias; Prathish, Krishnapillai Padmajakumari [Chemical Sciences and Technology Division (CSTD), National Institute for Interdisciplinary Science and Technology (NIIST)-CSIR, Trivandrum 695019 (India); Prasada Rao, Talasila, E-mail: tprasadarao@rediffmail.com [Chemical Sciences and Technology Division (CSTD), National Institute for Interdisciplinary Science and Technology (NIIST)-CSIR, Trivandrum 695019 (India)

    2011-04-15

    Graphical abstract: Surface imprinted nanospheres synthesized by modified precipitation polymerization method offer higher retention capacity and imprinting coefficients for removal of uranium from natural waters. - Abstract: Imprinted polymer nanospheres for uranium were prepared by complexing uranyl ion on to quinoline-8-ol functionalized 3-aminopropyltrimethoxysilane modified silica nanoparticles followed by surface imprinting with 4-VP (4-vinyl pyridine), HEMA (2-hydroxy ethyl methacrylate) and EGDMA (ethylene glycol dimethacrylate) as the functional monomers and cross linking agent respectively with AIBN (2,2'-azo-bis-isobutyronitrile) as initiator and 2-methoxyethanol as the porogen. Non-imprinted polymer material was also prepared under similar conditions omitting uranyl ion. The above materials were used for solid phase extraction of uranium. Recent realization that its chemical toxicity is dominant than radiation hazards makes decontamination a relevant topic for environmental point of view, particularly in the light of projected global thrust for uranium fuel based atomic power plants. The material offers high retention capacity of 97.1 {mu}mol g{sup -1} for 10 mg L{sup -1} of uranium that does not require tedious grinding and sieving steps, is water compatible and works in the pH range of 5-7, making it ideal for possible use in decontamination of polluted natural water samples or front end effluents of nuclear power reactors.

  1. Synthesis of surface imprinted nanospheres for selective removal of uranium from simulants of Sambhar salt lake and ground water

    International Nuclear Information System (INIS)

    Graphical abstract: Surface imprinted nanospheres synthesized by modified precipitation polymerization method offer higher retention capacity and imprinting coefficients for removal of uranium from natural waters. - Abstract: Imprinted polymer nanospheres for uranium were prepared by complexing uranyl ion on to quinoline-8-ol functionalized 3-aminopropyltrimethoxysilane modified silica nanoparticles followed by surface imprinting with 4-VP (4-vinyl pyridine), HEMA (2-hydroxy ethyl methacrylate) and EGDMA (ethylene glycol dimethacrylate) as the functional monomers and cross linking agent respectively with AIBN (2,2'-azo-bis-isobutyronitrile) as initiator and 2-methoxyethanol as the porogen. Non-imprinted polymer material was also prepared under similar conditions omitting uranyl ion. The above materials were used for solid phase extraction of uranium. Recent realization that its chemical toxicity is dominant than radiation hazards makes decontamination a relevant topic for environmental point of view, particularly in the light of projected global thrust for uranium fuel based atomic power plants. The material offers high retention capacity of 97.1 μmol g-1 for 10 mg L-1 of uranium that does not require tedious grinding and sieving steps, is water compatible and works in the pH range of 5-7, making it ideal for possible use in decontamination of polluted natural water samples or front end effluents of nuclear power reactors.

  2. Novo besouro-de-ambrosia em guanandi (Calophyllum brasiliense Cambessedes

    Directory of Open Access Journals (Sweden)

    Wagner Calixto de Castro Morais*

    2011-04-01

    Full Text Available Calophyllum brasiliense, known as Guanandi, is a heliophytic tree, and native to the Americancontinent and show great historic importance in Brazil. There is some information about insectsassociated with this tree species, but very few specific records. The aim of this study was to describethe occurrence and damage of a new Ambrosia beetle attacking Guanandi tree. In order to getthis information, pieces of attacked Guanandi branch were collected and kept under observationfor a period of 39 days. Adult beetles emerged from the timber were collected and measured.Branch pieces were dissected to evaluate the damage caused by the Ambrosia beetle to thewood. We collected 113 adult beetles, identified as Premnobius cavipennis, Eichhoff with a bodylength ranging from 2.7 to 2.9 mm. The timber infested with P. cavipennis had tunnels (galleries andholes, with diameters ranging from 1.1 to 1.3 mm. Furthermore, we observed that the timber showedstains around the galleries, which were caused by a fungus introduced by this beetle into the wood.This study is the first record of attack and damage of P. cavipennis in the Guanandi tree.

  3. Hydrochloric acid leaching of uranium, thorium, radium and rare-earth elements, from an Elliot lake radioactive ore

    International Nuclear Information System (INIS)

    Extraction of uranium by commercial methods using sulphuric acid developed a lot of environmental problems. To avoid such problems, other uranium extraction techniques have been adopted including fluorination, chlorination, chlorine assisted leaching, hydrochloric acid leaching, etc. This work is oriented towards the study of the factors controlling the hydrochloric acid leaching. The target of the study is to extract the total amount of U, Th, Ra-226 and rare earth elements. By using a suitable combination of the leaching factors, it was possible to achieve the designed target

  4. The ambrosia symbiosis is specific in some species and promiscuous in others: evidence from community pyrosequencing

    Czech Academy of Sciences Publication Activity Database

    Kostovčík, Martin; Bateman, C.C.; Kolařík, Miroslav; Stelinski, L.L.; Jordal, B.H.; Hulcr, J.

    2015-01-01

    Roč. 9, č. 1 (2015), s. 126-138. ISSN 1751-7362 Institutional support: RVO:61388971 Keywords : ambrosia symbiosis * pyrosequencing Subject RIV: EE - Microbiology, Virology Impact factor: 9.302, year: 2014

  5. APPROACHES ON THE INVASIVE ALIEN TAXA IN ROMANIA - AMBROSIA ARTEMISIIFOLIA (RAGWEED) II

    OpenAIRE

    Nicoleta IANOVICI

    2011-01-01

    In a previous paper we presented the localities in Romania where we identified populations of Ambrosia artemisiifolia. Between 2008-2011, investigations were continuing. Our data clearly show that Ambrosia is present throughout the country. The territories heavily infested are railway embankments, along traffic routes, gravel pits, building sites, forest edges, industrial areas, cemeteries and recreational areas. It is quite common to find ragweed in many private gardens, or flower pots in ur...

  6. The Action Programme Ambrosia in Germany – State of the art and future prospects

    OpenAIRE

    Starfinger, Uwe

    2012-01-01

    Common ragweed (Ambrosia artemisiifolia) originally from North America occurs as an alien species in several European countries. In Germany it has spread only recently. Because of its negative impact on agriculture and human health, further spread is undesired. At the Julius Kühn-Institute, Federal Research Centre for Cultivated Plants an “Interdisciplinary working group Ambrosia” has launched an Action Programme Ambrosia early in 2007 in order to prevent further spread of this alien plant. F...

  7. Spatio-Temporal Distribution of Bark and Ambrosia Beetles in a Brazilian Tropical Dry Forest.

    Science.gov (United States)

    Macedo-Reis, Luiz Eduardo; Novais, Samuel Matos Antunes de; Monteiro, Graziela França; Flechtmann, Carlos Alberto Hector; Faria, Maurício Lopes de; Neves, Frederico de Siqueira

    2016-01-01

    Bark and the ambrosia beetles dig into host plants and live most of their lives in concealed tunnels. We assessed beetle community dynamics in tropical dry forest sites in early, intermediate, and late successional stages, evaluating the influence of resource availability and seasonal variations in guild structure. We collected a total of 763 beetles from 23 species, including 14 bark beetle species, and 9 ambrosia beetle species. Local richness of bark and ambrosia beetles was estimated at 31 species. Bark and ambrosia composition was similar over the successional stages gradient, and beta diversity among sites was primarily determined by species turnover, mainly in the bark beetle community. Bark beetle richness and abundance were higher at intermediate stages; availability of wood was the main spatial mechanism. Climate factors were effectively non-seasonal. Ambrosia beetles were not influenced by successional stages, however the increase in wood resulted in increased abundance. We found higher richness at the end of the dry and wet seasons, and abundance increased with air moisture and decreased with higher temperatures and greater rainfall. In summary, bark beetle species accumulation was higher at sites with better wood production, while the needs of fungi (host and air moisture), resulted in a favorable conditions for species accumulation of ambrosia. The overall biological pattern among guilds differed from tropical rain forests, showing patterns similar to dry forest areas. PMID:27271969

  8. Position paper on the applicability of supplemental standards to the uppermost aquifer at the Uranium Mill Tailings Vitro Processing Site, Salt Lake City, Utah

    International Nuclear Information System (INIS)

    This report documents the results of the evaluation of the potential applicability of supplemental standards to the uppermost aquifer underlying the Uranium Mill Tailings Remedial Action (UMTRA) Project, Vitro Processing Site, Salt Lake City, Utah. There are two goals for this evaluation: provide the landowner with information to make an early qualitative decision on the possible use of the Vitro property, and evaluate the proposed application of supplemental standards as the ground water compliance strategy at the site. Justification of supplemental standards is based on the contention that the uppermost aquifer is of limited use due to wide-spread ambient contamination not related to the previous site processing activities. In support of the above, this report discusses the site conceptual model for the uppermost aquifer and related hydrogeological systems and establishes regional and local background water quality. This information is used to determine the extent of site-related and ambient contamination. A risk-based evaluation of the contaminants' effects on current and projected land uses is also provided. Reports of regional and local studies and U.S. Department of Energy (DOE) site investigations provided the basis for the conceptual model and established background ground water quality. In addition, a limited field effort (4 through 28 March 1996) was conducted to supplement existing data, particularly addressing the extent of contamination in the northwestern portion of the Vitro site and site background ground water quality. Results of the field investigation were particularly useful in refining the conceptual site model. This was important in light of the varied ground water quality within the uppermost aquifer. Finally, this report provides a critical evaluation, along with the related uncertainties, of the applicability of supplemental standards to the uppermost aquifer at the Salt Lake City Vitro processing site

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

    Science.gov (United States)

    Riegler, Thomas; Quirt, Dave; Beaufort, Daniel

    2016-02-01

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

  10. Fluids preserved in variably altered graphitic pelitic schists in the Dufferin Lake Zone, south-central Athabasca Basin, Canada: implications for graphite loss and uranium deposition

    Science.gov (United States)

    Pascal, Marjolaine; Boiron, Marie-Christine; Ansdell, Kevin; Annesley, Irvine R.; Kotzer, Tom; Jiricka, Dan; Cuney, Michel

    2016-06-01

    The Athabasca Basin (Canada) contains the highest grade unconformity-type uranium deposits in the world. Underlying the Athabasca Group sedimentary rocks of the Dufferin Lake Zone are variably graphitic, pelitic schists (VGPS), altered to chlorite and hematite (Red/Green Zone: RGZ). They were locally bleached near the unconformity during paleoweathering and/or later fluid interaction. Overall, graphite was lost from the RGZ and the bleached zone relative to the original VGPS. Fluid inclusions were examined in different generations of quartz veins, using microthermometry and Raman spectroscopy, to characterize and compare the different fluids that interacted with the RGZ and the VGPS. In the VGPS, CH4-, and N2-rich fluid inclusions, which homogenize into the vapor phase between -100 and -74 °C, and -152 and -125 °C, respectively, and CO2-rich fluid inclusions, homogenizing either into vapor or liquid between 20 and 28 °C, are present. Carbonic fluids could be the result of the breakdown of graphite to CH4 + CO2, whereas N2-rich fluid is interpreted to be the result of breakdown of feldspars/micas to NH4 ++N2. In the RGZ, the presence of fluid inclusions with low ice melting temperature (-38 to -16 °C) reflect the presence of CaCl2, and fluid inclusions with halite daughter minerals that dissolve between 190 and 240 °C indicate the presence of highly saline fluids. These fluids are interpreted to be derived from the Athabasca Basin. The circulation of carbonic fluids and brines occurred during two different events related to different P-T conditions of trapping. The carbonic fluids interacted with basement rocks during retrograde metamorphism of the basement rocks before deposition of the Athabasca Basin, whereas the brines circulated after the deposition of the Athabasca Basin. These latter fluids are similar to brines related to uranium mineralization at McArthur River and thus, in addition to possibly being related to graphite depletion in the RGZ, they could

  11. Suitability of California bay laurel and other species as potential hosts for the non-native redbay ambrosia beetle and granulate ambrosia beetle

    Science.gov (United States)

    The redbay ambrosia beetle (Xyleborus glabratus Eichhoff) is a non-native invasive forest pest and vector of the pathogen that causes laurel wilt, a deadly disease of trees in the family Lauraceae in the southeastern United States (U.S.). Concern exists that X. glabratus and its fungal symbiont cou...

  12. /sup 137/Cs radioactive dating of Lake Ontario sediment cores

    Energy Technology Data Exchange (ETDEWEB)

    Ward, T.E.; Breeden, J.; Komisarcik, K.; Porter, R.; Czuczwa, J.; Kaminski, R.; McVeety, B.D.

    1987-12-01

    The distribution of /sup 137/Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with /sup 210/Pb dating and distribution of Ambrosia (ragweed) pollen compare well with /sup 137/Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs.

  13. 137Cs radioactive dating of Lake Ontario sediment cores

    International Nuclear Information System (INIS)

    The distribution of 137Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 137Cs dating. These methods can determine with precision, changes in sedimentation occurring over the past 100 years or so. Typical sedimentation rates of 0.18-0.36 cm/yr were measured. 16 refs., 3 figs., 2 tabs

  14. Mineralogical and process controls on the oxidative acid-leaching of radioactive phases in Elliot Lake, Ontario, uranium ores: II - Brannerite and allied titaniferous assemblages

    International Nuclear Information System (INIS)

    In representative run-of-mine samples from the Panel and New Quirke mines of the Elliot Lake uranium district, Ontario, brannerite, a metamict uranous titanate, occurs in microscopic grain-aggregates which display wide variations, both in textural habit and in the relative proportions of brannerite, titania polymorphs and/or 'uraniferous titania'. As is widely documented, much of the brannerite occurs as trellis-like arrays of laths and needles pseudomorphing rutile or anatase. In some cases, the laths and needles are cemented by coffinite. Brannerite, with an average composition of (U0.629 Th0.039 Ca0.020) (Ti2.199 Fe0.13)O69 contains ≤3 wt% Th and is distinctly Ti-rich relative to the ideal composition, UTi2O6. Much of the Si reporting consistently in electron microprobe analyses (between 1 wt% and 5 wt%) is tentatively attributed to contamination by the quartz-sericite matrix, and a minor proportion is attributed to the presence of coffinite intergrowths. 'Uraniferous titania' (average partial composition by weight: 10.8% U, 0.3% Th, 32.9% Ti) is considered to represent an intermediate stage in the conversion of titania to brannerite. The leaching behaviour of brannerite in its different modes of occurence was studied qualitatively by the rotating-disc (polished section). (author). 23 refs., 4 tabs., 11 figs

  15. Canada: The largest uranium producer

    International Nuclear Information System (INIS)

    Despite all the current difficulties, previous erroneous forecasts and other mistakes, the longer term future looks good for uranium mining and for Canada's industry in particular. Saskatchewan continues to offer the most exciting new prospects, the huge and fabulously high grade Cigar Lake deposits being the most spectacular of the recent discoveries. Notwithstanding continuous mining for 30 years from Elliot Lake there still remain there significant uncommitted reserves which can be developed when the market for uranium is in better balance

  16. Sieben Jahre Aktionsprogramm Ambrosia in Bayern – eine Bestandsaufnahme

    Directory of Open Access Journals (Sweden)

    Brix, Jutta

    2014-07-01

    Full Text Available Since 2005 the common ragweed, Ambrosia artemisiifolia, which was introduced from North America has also been found in Bavaria in larger stocks and has an increasing tendency to spread. After receiving the report of the Bavarian Ministry of Health, the Bavarian Parliament addressed the implications for health. There was consensus across all political groups to combat the plant. Under the auspices of the Ministry of Health the action programme “eradication campaign against ragweed” aimed at systematic control was set up in 2007 in cooperation with the Ministries of Agriculture (registration office at the State Research Center for Agriculture and the Interior (district administration authorities. The 96 district administration authorities, which each have a trained ragweed officer, report to the registration office on new verified ragweed locations with more than 100 plants. The reports of common ragweed stands are filed by citizens or through research by the district administration authorities, who are also responsible for supporting the fight against stocks. On behalf of the Bavarian Ministry of Health, the Working Group Biodiversity monitors the situation and finds many new locations. Since 2006, 279 new common ragweed stocks were registered. After control measures there are currently 190 known remaining stocks. Since 2007, however, the populated area has tripled. This means that the control measures need further improvement. This is especially true for the common ragweed stocks along roadsides where the plants have increased massively in recent years. Sustainable control has proved to be particularly difficult.

  17. Combining cutting and herbicide application for Ambrosia artemisiifolia control

    Directory of Open Access Journals (Sweden)

    Sölter, Ulrike

    2016-02-01

    Full Text Available The effect on Ambrosia artemisiifolia (common ragweed of combining cutting and herbicide application was studied in pot experiments in Germany and Denmark in 2013. Single plants of common ragweed were established in 2 L pots in glasshouses. Two cutting treatments were conducted: cutting to 10 cm height at the beginning of male budding (BBCH 51-59 and no cutting. Clopyralid (in Germany: Lontrel 600, in Denmark: Matrigon, mesotrione (in Germany and Denmark: Callisto and glyphosate (in Germany: Clinic, in Denmark: Roundup Bio were applied at 4 doses at three different timings: on the day of cutting, one week and two weeks after cutting. The plants were harvested 5 weeks after the last herbicide application. At both sites clopyralid and mesotrione had a low efficacy on common ragweed when applied on developed plants with only minor differences in efficacy at the three timings. Application after cutting improved the efficacy of clopyralid at both sites and of mesotrione in Denmark. In Germany glyphosate had a higher efficacy on noncut plants in comparison to the cut plants, in Denmark it was vice versa. The highest dose of glyphosate provided higher control levels on developed plants than clopyralid and mesotrione at both sites. In Denmark the highest effects were obtained shortly after cutting with the maximum dose of each herbicide and declined with time between cutting and herbicide application. In summary the results demonstrated that herbicides can be applied shortly after cutting without loss of efficacy.

  18. Daily Ambrosia Pollen Concentration in the Air of Ankara,Turkey (1990-1999)

    Institute of Scientific and Technical Information of China (English)

    Ayse KAPLAN; Nazmiye SAKIYAN; N Münevver PINAR

    2003-01-01

    The airborne ragweed pollen spectrum was investigated in the air of Ankara, Turkey for aperiod of ten years (1990-1999) using a Burkard seven-day volumetric recording trap. In our study period,long distance transported Ambrosia pollen has been registered. Daily pollen levels varied from low to highin Burge's system. In last three years, the pollen concentration of Ambrosia showed a clear increasingtendency. Our results prove that ragweed pollen may be an important threat for ragweed sensitive patientsin Ankara city in near future.

  19. The Key Lake project

    International Nuclear Information System (INIS)

    Key Lake is located in the Athabasca sand stone basin, 640 kilometers north of Saskatoon, Saskatchewan, Canada. The three sources of ore at Key Lake contain 70 100 tonnes of uranium. Features of the Key Lake Project were described under the key headings: work force, mining, mill process, tailings storage, permanent camp, environmental features, worker health and safety, and economic benefits. Appendices covering the historical background, construction projects, comparisons of western world mines, mining statistics, Northern Saskatchewan surface lease, and Key Lake development and regulatory agencies were included

  20. New species of Geosmithia and Graphium associated with ambrosia beetles in Costa Rica

    Czech Academy of Sciences Publication Activity Database

    Kolařík, Miroslav; Hulcr, J.; Kirkendall, L.R.

    2015-01-01

    Roč. 67, č. 1 (2015), s. 29-35. ISSN 1211-0981 R&D Projects: GA ČR(CZ) GAP506/11/2302 Institutional support: RVO:61388971 Keywords : ambrosia fungi * Hypocreales * Scolytodes Subject RIV: EE - Microbiology, Virology

  1. Repeated evolution of crop theft in fungus-farming ambrosia beetles.

    Science.gov (United States)

    Hulcr, Jiri; Cognato, Anthony I

    2010-11-01

    Ambrosia beetles, dominant wood degraders in the tropics, create tunnels in dead trees and employ gardens of symbiotic fungi to extract nutrients from wood. Specificity of the beetle-fungus relationship has rarely been examined, and simple vertical transmission of a specific fungal cultivar by each beetle species is often assumed in literature. We report repeated evolution of fungal crop stealing, termed mycocleptism, among ambrosia beetles. The mycocleptic species seek brood galleries of other species, and exploit their established fungal gardens by tunneling through the ambient mycelium-laden wood. Instead of carrying their own fungal sybmbionts, mycocleptae depend on adopting the fungal assemblages of their host species, as shown by an analysis of fungal DNA from beetle galleries. The evidence for widespread horizontal exchange of fungi between beetles challenges the traditional concept of ambrosia fungi as species-specific symbionts. Fungus stealing appears to be an evolutionarily successful strategy. It evolved independently in several beetle clades, two of which have radiated, and at least one case was accompanied by a loss of the beetles' fungus-transporting organs. We demonstrate this using the first robust phylogeny of one of the world's largest group of ambrosia beetles, Xyleborini. PMID:20633043

  2. Erhöhte Frosttoleranz und vorteilhafte Keimeigenschaften in europäischen Ambrosia artemisiifolia Populationen

    OpenAIRE

    Leiblein-Wild, Marion Carmen; Kaviani, Rana; Tackenberg, Oliver

    2014-01-01

    Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants. Within this study, we investigated germination characteristics of Ambrosia artemisiifolia L. populations from native and invasive ranges. We determined germination rates and speed under different temperature conditions. From these parameters we calculated minimal, optimal, and maximal temperature for germination. We also investigated the frost tolerance of seed...

  3. Comparison of ambrosia beetle communities in two host with laurel wilt: swampbay vs. avocado

    Science.gov (United States)

    The invasive redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), is an exotic wood-boring pest first detected in 2002 near Savannah, Georgia. The beetle’s dominant fungal symbiont, Raffaelea lauricola, is the pathogen that causes laurel wilt, a lethal disease of tre...

  4. A plant taxonomic survey of the Uranium City region, Lake Athabasca north shore, emphasizing the naturally colonizing plants on uranium mine and mill wastes and other human-disturbed sites

    International Nuclear Information System (INIS)

    A goal of this study was to acquire more complete baseline data on the existing flora of the Uranium City region, both in natural and human-disturbed sites. Emphasis was given to determining which plant species were naturally revegetating various abandoned uranium mine and mill waste disposal areas, other human-disturbed sites, and ecologically analogous sites. Another goal was to document the occurrence and distribution in the study region of rare and possibly endangered species. A further objective was to suggest regionally-occurring species with potential value for revegetating uranium mine and mill waste sites. Field investigations were carried out in the Uranium City region during August, 1981. During this time 1412 plant collections were made; a total of 366 plant species - trees, shrubs, forbs, graminoids, lichens, and bryophytes were recorded. The report includes an annotated checklist of plant species of the Uranium City region and a reference index of plant taxa indicating species that have high revegetation potential

  5. Western Canada uranium perspective

    International Nuclear Information System (INIS)

    The current situation in the exploration for uranium in British Columbia, the Yukon, the Northwest Territories, and Saskatchewan is reviewed. A moratorium on exploration has been in effect in British Columbia since 1980; it is due to expire in 1987. Only the Blizzard deposit appears to have any economic potential. The Lone Gull discovery in the Thelon Basin of the Northwest Territories has proven reserves of more than 35 million pounds U3O8 grading 0.4%. Potentially prospective areas of the northern Thelon Basin lie within a game sanctuary and cannot be explored. Exploration activity in Saskatchewan continues to decline from the peak in 1980. Three major deposits - Cluff Lake, Rabbit Lake and Key Lake - are in production. By 1985 Saskatchewan will produce 58% of Canada's uranium, and over 13% of the western world's output. (L.L.) (3 figs, 2 tabs.)

  6. Ontario's uranium mining industry

    International Nuclear Information System (INIS)

    This report traces the Ontario uranium mining industry from the first discovery of uranium north of Sault Ste. Marie through the uranium boom of the 1950's when Elliot Lake and Bancroft were developed, the cutbacks of the 1960s, the renewed enthusiasm in exploration and development of the 1970s to the current position when continued production for the domestic market is assured. Ontario, with developed mines and operational expertise, will be in a position to compete for export markets as they reopen. The low level of expenditures for uranium exploration and the lack of new discoveries are noted. The report also reviews and places in perspective the development of policies and regulations governing the industry and the jurisdictional relationships of the Federal and Provincial governments

  7. Effect of tree species and end seal on attractiveness and utility of cut bolts to the redbay ambrosia beetle and granulate ambrosia beetle (coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Mayfield, A E; Hanula, J L

    2012-04-01

    The redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is a non-native invasive pest and vector of the fungus that causes laurel wilt disease in certain trees of the family Lauraceae. This study assessed the relative attractiveness and suitability of cut bolts of several tree species to X. glabratus. In 2009, female X. glabratus were equally attracted to traps baited with swampbay (Persea palustris (Rafinesque) Sargent) and camphortree (Cinnamomum camphora (L.) J. Presl), which were more attractive than avocado (Persea americana Miller), lancewood (Ocotea coriacea (Swartz) Britton), and sweetbay (Magnolia virginiana L.). These species were more attractive than loblolly bay (Gordonia lasianthus (L.) J. Ellis). X. glabratus entrance hole density and emergence from caged bolts were highest on swampbay and camphortree. In 2010, swampbay was significantly more attractive to X. glabratus than sassafras (Sassafras albidum (Nuttall) Nees), yellow poplar (Liriodendron tulipifera L.), and eastern redbud (Cercis canadensis L.). Sassafras bolts end sealed with a liquid wax-and-water emulsion were more attractive to X. glabratus than end-sealed bolts of yellow poplar and redbud. Relative to unsealed bolts, end seal decreased X. glabratus entrance hole density on swampbay and decreased granulate ambrosia beetle (Xylosandrus crassiusculus (Motschulsky)) trap catch, entrance hole density, and adult emergence from swampbay. X. crassiusculus was not attracted to sassafras, yellow poplar, and redbud and was not more attracted to manuka oil than to unbaited traps. Sassafras was more attractive to X. glabratus than previously reported and supported reproducing populations of the insect. End sealing bolts with a wax-and-water emulsion may not be optimal for attracting and rearing ambrosia beetles in small logs. PMID:22606816

  8. Minireview: importance of herbicide-tolerant sunflower hybrids in suppressing common ragweed (Ambrosia artemisiifolia) pollen production

    OpenAIRE

    Peter Reisinger; Gabor Kukorelli; Andras Bittsanszky; Tamas Komives

    2014-01-01

    Common ragweed (Ambrosia artemisiifolia) is the number one weed in Hungary: it covers ca. 5% of the arable land, causing huge losses in row crops, especially in sunflowers. In addition, because of the high allergenicity of its pollen, common ragweed is a heavy burden on the health care system. This minireview discusses the importance of use of herbicide-tolerant sunflower hybrids in eliminating common ragweed from sunflower fields, with special emphasis on the efficacy of common ragweed contr...

  9. Yeast Associated with the Ambrosia Beetle, Platypus koryoensis, the Pest of Oak Trees in Korea

    OpenAIRE

    Yun, Yeo Hong; Suh, Dong Yeon; Yoo, Hun Dal; Oh, Man Hwan; Kim, Seong Hwan

    2015-01-01

    Oak tree death caused by symbiosis of an ambrosia beetle, Platypus koryoensis, and an ophiostomatoid filamentous fungus, Raffaelea quercus-mongolicae, has been a nationwide problem in Korea since 2004. In this study, we surveyed the yeast species associated with P. koryoensis to better understand the diversity of fungal associates of the beetle pest. In 2009, a total of 195 yeast isolates were sampled from larvae and adult beetles (female and male) of P. koryoensis in Cheonan, Goyang, and Paj...

  10. Effect of plant growth promoting rhizobacteria on Ambrosia rtemisiifolia L. seed germination

    OpenAIRE

    Vrbničanin Sava; Božić Dragana; Sarić Marija; Pavlović Danijela; Raičević Vera

    2011-01-01

    Soil bacteria are able either to stimulate or inhibit seed germination. If seed germination is stimulated, the seedlings of weed species emerge more uniformly, so that they could be killed in the next step of weed control. This investigation focused on testing the germination of Ambrosia artemisiifolia L. on several media: Pseudomonas fluorescens (B1), Azotobacter chroococcum (B2), Bacillus licheniformis (B3), B. pumilus (B4), B. amyloliquefaciens (B5). In ...

  11. Effect of Plant Growth Promoting Rhizobacteria on Ambrosia artemisiifolia L. Seed Germination

    OpenAIRE

    Sava Vrbničanin; Dragana Božić; Marija Sarić; Danijela Pavlović; Vera Raičević

    2011-01-01

    Soil bacteria are able either to stimulate or inhibit seed germination. If seed germination is stimulated, the seedlings of weed species emerge more uniformly, so that they could be killed in the next step of weed control. This investigation focused on testing the germination of Ambrosia artemisiifolia L. on several media: Pseudomonas fluorescens (B1), Azotobacter chroococcum (B2), Bacillus licheniformis (B3), B. pumilus (B4), B. amyloliquefaciens (B5). In control, seeds germinated in water. ...

  12. Plants remember past weather: a study for atmospheric pollen concentrations of Ambrosia, Poaceae and Populus

    Science.gov (United States)

    Matyasovszky, István; Makra, László; Csépe, Zoltán; Sümeghy, Zoltán; Deák, Áron József; Pál-Molnár, Elemér; Tusnády, Gábor

    2015-10-01

    After extreme dry (wet) summers or years, pollen production of different taxa may decrease (increase) substantially. Accordingly, studying effects of current and past meteorological conditions on current pollen concentrations for different taxa have of major importance. The purpose of this study is separating the weight of current and past weather conditions influencing current pollen productions of three taxa. Two procedures, namely multiple correlations and factor analysis with special transformation are used. The 11-year (1997-2007) data sets include daily pollen counts of Ambrosia (ragweed), Poaceae (grasses) and Populus (poplar), as well as daily values of four climate variables (temperature, relative humidity, global solar flux and precipitation). Multiple correlations of daily pollen counts with simultaneous values of daily meteorological variables do not show annual course for Ambrosia, but do show definite trends for Populus and Poaceae. Results received using the two methods revealed characteristic similarities. For all the three taxa, the continental rainfall peak and additional local showers in the growing season can strengthen the weight of the current meteorological elements. However, due to the precipitation, big amount of water can be stored in the soil contributing to the effect of the past climate elements during dry periods. Higher climate sensitivity (especially water sensitivity) of the herbaceous taxa ( Ambrosia and Poaceae) can be definitely established compared to the arboreal Populus. Separation of the weight of the current and past weather conditions for different taxa involves practical importance both for health care and agricultural production.

  13. Limno-chemical and microbiology aspects in Uranium Pit Mine Lake (Osamu Utsumi), in Antas and Bortolan reservoirs under the influence of effluent Ore Treatment Unit, Caldas - Minas Gerais State, Brazil

    International Nuclear Information System (INIS)

    Due to high natural radioactivity there in Pocos de Caldas Plateau (Minas Gerais State, Brazil) and the existence of the first uranium mine in Brazil (Pit Mine Osamu Utsumi - Mineral Treatment Unit/Brazilian Nuclear Industries, MTU/BNI), which is characterized by an open-pit mine presents as increased environmental liability the formation of acid mine drainage, this study was conducted to evaluate the limno-chemicals and microbiology aspects (protozooplankton and bacterioplankton) belonging to uranium pit mine lake (PM) and evaluate the possible effects of acid effluents treated and discharged by MTU/BNI in Antas reservoir-AR and downstream of this, the Bortolan reservoir-BR. Besides the realization of abiotic and microbiology analysis of protozooplankton and bacterioplankton; was held standardization and deployment of the Fluorescence 'In Situ' Hybridization (FISH) technical using oligonucleotide probes for extremophile Archaea and Bacteria. According to the results, the PM showed the highest values for the chemical variables, lower pH values, lower protozooplankton density, however, protozooplanktonic high biomass showing the presence of tolerant species in this extreme environment. Antas and Bortolan reservoirs showed differences in the abiotic and biotic variables, AR showed suffer greater interference of acid effluents released at P41point and downstream of this at P14 point, lower protozooplankton biomass, lower bacterial density and pollution characteristics of inorganic sources. Using the FISH technique standard in this study to water bodies evaluated, it was possible to detect the presence of the extremophile bacteria of the Archaea domain in the three water bodies. The results of this study contribute to the knowledge of the pit mine lakes limnology which have become a major concern due to increased mining in the open. (author)

  14. Limno-chemical and microbiology aspects in Uranium Pit Mine Lake (Osamu Utsumi), in Antas and Bortolan reservoirs under the influence of effluent Ore Treatment Unit, Caldas - Minas Gerais State, Brazil

    Energy Technology Data Exchange (ETDEWEB)

    Ronqui, Leilane B.; Nasciment, Marcos R.L. do; Roque, Claudio V.; Bruschi, Armando; Borba Junior, Palvo J.; Nascimento, Heliana A. F. do, E-mail: leilanebio@yahoo.com.br, E-mail: pmarcos@cnen.gov.br, E-mail: cvroque@cnen.gov.br, E-mail: abruschi@cnen.gov.br, E-mail: jouber_borba@hotmail.com, E-mail: hazevedo@cnen.gov.br [Comissao Nacional de Energia Nuclear (LAPOC/CNEN), Pocos de Caldas, MG (Brazil). Laboratorio de Pocos de Caldas; Almeida, Tito C.M. de, E-mail: titoalmeida2008@gmail.com [Universidade do Vale do Itajai (CTT-Mar/UNIVALI), SC (Brazil). Centro de Ciencias Tecnologicas da Terra e do Mar

    2013-07-01

    Due to high natural radioactivity there in Pocos de Caldas Plateau (Minas Gerais State, Brazil) and the existence of the first uranium mine in Brazil (Pit Mine Osamu Utsumi - Mineral Treatment Unit/Brazilian Nuclear Industries, MTU/BNI), which is characterized by an open-pit mine presents as increased environmental liability the formation of acid mine drainage, this study was conducted to evaluate the limno-chemicals and microbiology aspects (protozooplankton and bacterioplankton) belonging to uranium pit mine lake (PM) and evaluate the possible effects of acid effluents treated and discharged by MTU/BNI in Antas reservoir-AR and downstream of this, the Bortolan reservoir-BR. Besides the realization of abiotic and microbiology analysis of protozooplankton and bacterioplankton; was held standardization and deployment of the Fluorescence 'In Situ' Hybridization (FISH) technical using oligonucleotide probes for extremophile Archaea and Bacteria. According to the results, the PM showed the highest values for the chemical variables, lower pH values, lower protozooplankton density, however, protozooplanktonic high biomass showing the presence of tolerant species in this extreme environment. Antas and Bortolan reservoirs showed differences in the abiotic and biotic variables, AR showed suffer greater interference of acid effluents released at P41point and downstream of this at P14 point, lower protozooplankton biomass, lower bacterial density and pollution characteristics of inorganic sources. Using the FISH technique standard in this study to water bodies evaluated, it was possible to detect the presence of the extremophile bacteria of the Archaea domain in the three water bodies. The results of this study contribute to the knowledge of the pit mine lakes limnology which have become a major concern due to increased mining in the open. (author)

  15. APPROACHES ON THE INVASIVE ALIEN TAXA IN ROMANIA - AMBROSIA ARTEMISIIFOLIA (RAGWEED II

    Directory of Open Access Journals (Sweden)

    Nicoleta IANOVICI

    2011-01-01

    Full Text Available In a previous paper we presented the localities in Romania where we identified populations of Ambrosia artemisiifolia. Between 2008-2011, investigations were continuing. Our data clearly show that Ambrosia is present throughout the country. The territories heavily infested are railway embankments, along traffic routes, gravel pits, building sites, forest edges, industrial areas, cemeteries and recreational areas. It is quite common to find ragweed in many private gardens, or flower pots in urban areas. The few foci observed along riversides got there by household waste and construction waste. In many rural communities find it on the drainage ditches. Disturbed and neglected land (on city limits and outside the city, abandonment of land without subsequent turning of stubble and another wrong agricultural practice, absence of ruderal weed control are the main causes that favor the dissemination of our country. Intensity of anthropogenic influence is manifested mainly by transport of materials and soil movement during road rehabilitation and construction of highways. The recent observations show that could be expected to appear on agricultural fields, now being found only on the outskirts of cultivated land, at 5-6 meters from high traffic roads. Ambrosia benefits from human activities to spread. This implies a strong control strategy. The main objective of the fighting activities need to be to reduce damages caused by its pollen and to limit its expansion. If invasion by Ambrosia is left uncontrolled, increase of allergies could heavily augment the treatments. Knowledge about mechanical or chemical control of ragweed could be very important for road and rail services, agricultural institutions, farmers, staff responsible for managing natural areas, institutions that approves and oversees residential sites and factories, responsible personnel of the administrations from cities and rural localities. Reducing the population is more required than

  16. Canadian experience with uranium tailings disposal

    International Nuclear Information System (INIS)

    During the first years of uranium production in Canada uranium tailings were discharged directly into valleys or lakes near the mill. Treatment with barium chloride to precipitate radium began in 1965 at the Nordic Mine at Elliot Lake, Ontario. In the mid-60s and early 70s water quality studies indicated that discharges from uranium tailings areas were causing degradation to the upper part of the Serpent River water system. Studies into acid generation, revegetation, and leaching of radium were initiated by the mining companies and resulted in the construction of treatment plants at a number of sites. Abandoned tailings sites were revegetated. At hearings into the expansion of the Elliot Lake operations the issue of tailings management was a major item for discussion. As a result federal and provincial agencies developed guidelines for the siting and development of urnaium tailings areas prior to issuing operating licences. Western Canadian uranium producers do not have the acid generation problem of the Elliot Lake operations. The Rabbit Lake mill uses settling ponds followed by filtration. High-grade tailings from Cluff Lake are sealed in concrete and buried. Uranium producers feel that the interim criteria developed by the Atomic Energy Control Board, if adopted, would have a harmful effect on the viability of the Canadian uranium industry

  17. Spatial Distribution of Ambrosia Weediness in Soybean at Different Rates of Nitrogen Fertilization, based on Digital Imagery Analysis

    Directory of Open Access Journals (Sweden)

    Ivana Vuković

    2007-03-01

    Full Text Available In order to determine distribution of ambrosia within soybean at different fertilization rates on experimental field Potok–Popovača (2005, technique of aerial digital imaging at ground level by digital RGB camera was applied. The digital imaging was carried out within multidiscipline research team: Faculty of Agriculture, Faculty of Geodesy and Croatian Centre for Demining. Area of cca. 4 ha (300x130m, was under long time research with 10 different rates of nitrogen fertilization. Based on interpretation of aerial digital imagery, the main object of this study was to determine ambrosia weediness in soybean at different rates of nitrogen fertilization, its spatial distribution within soybean, and nitrogen taking by ambrosia and soybean. Ambrosia detection from aerial digital RGB imagery and its spatial distribution have been defined. Bases to continue research by airborne multispectral digital imaging of experimental field within different crops during following years were provided. Digital imaging of field variants at diff erent fertilization rates, and ground samples (4 by experimental variant, including land surveying, was performed by digital RGB camera from 13th - 25th September, 2005. Interpretation of aerial digital imagery was made by field data analysis obtained by sampling plant material, in order to determine biomass, moisture and nitrogen content in both species. Comparison with field data shows that method of aerial digital RGB imagery interpretation is reliable mean of weed detection within immanent crop, and its spatial distribution at different fertilization rates – ambrosia distribution/variant.

  18. Scientific Opinion on the effect on public or animal health or on the environment on the presence of seeds of Ambrosia spp. in animal feed

    DEFF Research Database (Denmark)

    Baker, R.; Candresse, T.; Dormannsné Simon, E.;

    2010-01-01

    The European Commission requested EFSA to provide a scientific opinion on the effect on public or animal health or on the environment on the further distribution of Ambrosia spp. in the European Union and on the importance of feed materials, in particular bird feed, in the dispersion of Ambrosia...... spp. The genus Ambrosia (Asteraceae family) is distributed worldwide. Ambrosia artemisiifolia (common ragweed) has heavily colonised several areas of South-East Europe. Ambrosia spp., both in their native range and in invaded areas, are of public health concern due to the allergenic properties of...

  19. Uranium conversion

    International Nuclear Information System (INIS)

    FOI, has performed a study on uranium conversion processes that are of importance in the production of different uranium compounds in the nuclear industry. The same conversion processes are of interest both when production of nuclear fuel and production of fissile material for nuclear weapons are considered. Countries that have nuclear weapons ambitions, with the intention to produce highly enriched uranium for weapons purposes, need some degree of uranium conversion capability depending on the uranium feed material available. This report describes the processes that are needed from uranium mining and milling to the different conversion processes for converting uranium ore concentrate to uranium hexafluoride. Uranium hexafluoride is the uranium compound used in most enrichment facilities. The processes needed to produce uranium dioxide for use in nuclear fuel and the processes needed to convert different uranium compounds to uranium metal - the form of uranium that is used in a nuclear weapon - are also presented. The production of uranium ore concentrate from uranium ore is included since uranium ore concentrate is the feed material required for a uranium conversion facility. Both the chemistry and principles or the different uranium conversion processes and the equipment needed in the processes are described. Since most of the equipment that is used in a uranium conversion facility is similar to that used in conventional chemical industry, it is difficult to determine if certain equipment is considered for uranium conversion or not. However, the chemical conversion processes where UF6 and UF4 are present require equipment that is made of corrosion resistant material

  20. Dominique-Janine extension, McClean Lake project, and midwest joint venture: report of the joint Federal-Provincial panel on uranium mining developments in Northern Saskatchewan

    International Nuclear Information System (INIS)

    A report of the joint federal-provincial panel on uranium mining developments in northern Saskatchewan. The review of the projects have taken into consideration the impact upon the peoples living in northern Saskatchewan. Benefits will be seen in the form of employment, business opportunities and royalties while causing only a small incremental increase to existing environmental and health risks

  1. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site in Lakeview, Oregon

    International Nuclear Information System (INIS)

    This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site in Lake view, Oregon evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site

  2. Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site in Lakeview, Oregon

    Energy Technology Data Exchange (ETDEWEB)

    1994-10-01

    This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site in Lake view, Oregon evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site.

  3. Some aspects of chemical ecology of the sponges of the Caribbean, Axinyssa ambrosia and Aplysina insularis

    International Nuclear Information System (INIS)

    Axinyssamine hydrochloride (compound 1) was recently found in the marine sponge Axinyssa ambrosia at concentrations in the order of 10 mg/ml. Lethality assays using compound 1 against the coral Madracis mirabilis allowed determining that the mentioned compound is lethal to coral polyps at the natural concentration present in the sponge. Additionally, by performing exudation experiments in aquaria and chemical detection by HRGC-MS (scan and sim modes) it was found that the compounds ll-formamide-7β-H-eudesm-5-ene (2) and 4 α-formamidogorgon-ll-ene (3) are continually exuded by Axinyssa ambrosia creating a protective chemical barrier around the sponge. Exudation rates increase 3.80 and 2.47 fold respectively for each compound, under stress conditions or aggression. These results suggest that the sponge Axinyssa ambrosia may use the above-mentioned three metabolites as chemical defenses. Other experiments were carried out with the sponge Aplysina insularis in situ, under ecologically relevant conditions, with the purpose of determining if the chemical composition (Brominated metabolites) changes over variable time periods after inflicting wounds on the sponge surface. Metabolites were detected and identified by LC-MS. No evidence of chemical transformation of high molecular weight compounds into the compounds Aeroplysinin-l (4) and/or the dibromo cyclohexadienone (5) was obtained as a consequence of tissue damage, both in short (2,5 minutes) and long duration experiments (120 minutes). These results suggest that the conversion of high molecular weight compounds into small, active forms does not take place in Aplysina insularis as a chemical defense mechanism

  4. Uranium in Canada

    International Nuclear Information System (INIS)

    In 1988 Canada's five uranium producers reported output of concentrate containing a record 12,470 metric tons of uranium (tU), or about one third of total Western world production. Shipments exceeded 13,200 tU, valued at $Cdn 1.1 billion. Most of Canada's uranium output is available for export for peaceful purposes, as domestic requirements represent about 15 percent of production. The six uranium marketers signed new sales contracts for over 11,000 tU, mostly destined for the United States. Annual exports peaked in 1987 at 12,790 tU, falling back to 10,430 tU in 1988. Forward domestic and export contract commitments were more than 70,000 tU and 60,000 tU, respectively, as of early 1989. The uranium industry in Canada was restructured and consolidated by merger and acquisition, including the formation of Cameco. Three uranium projects were also advanced. The Athabasca Basin is the primary target for the discovery of high-grade low-cost uranium deposits. Discovery of new reserves in 1987 and 1988 did not fully replace the record output over the two-year period. The estimate of overall resources as of January 1989 was down by 4 percent from January 1987 to a total (measured, indicated and inferred) of 544,000 tU. Exploration expenditures reached $Cdn 37 million in 1987 and $59 million in 1988, due largely to the test mining programs at the Cigar Lake and Midwest projects in Saskatchewan. Spot market prices fell to all-time lows from 1987 to mid-1989, and there is little sign of relief. Canadian uranium production capability could fall below 12,000 tU before the late 1990s; however, should market conditions warrant output could be increased beyond 15,000 tU. Canada's known uranium resources are more than sufficient to meet the 30-year fuel requirements of those reactors in Canada that are now or are expected to be in service by the late 1990s. There is significant potential for discovering additional uranium resources. Canada's uranium production is equivalent, in

  5. Ambrosia maritima L., Molluscicide végétal prometteur !

    Directory of Open Access Journals (Sweden)

    Sidhom, MZ.

    1983-01-01

    Full Text Available Ambrosia maritima L., a promising molluscicide of plant origin !. Masses of granivorous birds destroy about 5-10 % of the rice crop produced in the central Niger delta. To the local species (ducks, ploceid birds and the quelea, which is the most abundant and noxious pest with numbers ranging from 18 million in January to 10 million in May-June add palearctic migratory birds, which are mainly ducks and stilt-birds. Bird control is necessarily undertaken but is inefficient due to the vastness of the region, difficult access to the sites, the number of birds and insufficient financial means.

  6. Ambrosia maritima L., Molluscicide végétal prometteur !

    OpenAIRE

    Sidhom, MZ.; GEERTS, S

    1983-01-01

    Ambrosia maritima L., a promising molluscicide of plant origin !. Masses of granivorous birds destroy about 5-10 % of the rice crop produced in the central Niger delta. To the local species (ducks, ploceid birds and the quelea, which is the most abundant and noxious pest with numbers ranging from 18 million in January to 10 million in May-June) add palearctic migratory birds, which are mainly ducks and stilt-birds. Bird control is necessarily undertaken but is inefficient due to the vastness ...

  7. Fusarium symbionts of an ambrosia beetle (Euwallacea sp.) in southern Florida are pathogens of avocado, Persea americana

    Science.gov (United States)

    Fusarium dieback, a destructive disease of avocado (Persea americana), was reported in California and Israel in 2012. It is associated with an ambrosia beetle, Euwallacea sp., and damage caused by an unnamed symbiont of the beetle in Clade 3 of the Fusarium solani species complex (FSSC) designated p...

  8. Flood stress as a technicque to assess preventive insecticide and fungicide treatments for protecting trees against ambrosia beetles

    Science.gov (United States)

    The exotic ambrosia beetles Xylosandrus germanus, Xylosandrus crassiusculus, and Xylosandrus compactus tunnel into the heartwood of trees where they cultivate and feed upon a symbiotic fungus. We assessed the effectiveness of flood stress as a tactic for making trees attractive and vulnerable to att...

  9. Efficacy and longevity of essential oil lures for capture of the redbay ambrosia beetle Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

    Science.gov (United States)

    The redbay ambrosia beetle Xyleborus glabratus Eichhoff is an exotic wood-boring pest native to southeastern Asia. It carries a symbiotic fungus (Raffaelea lauricola) that causes laurel wilt, a lethal vascular disease of trees in the Lauraceae. First detected in Georgia in 2002, the beetle has spre...

  10. Fusarium euwallaceae sp. nov.—a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California

    Science.gov (United States)

    The invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) and a novel Fusarium sp. that it farms in its galleries as a source of nutrition seriously damage over 20 species of live trees and pose a serious threat to avocado production (Persea americana) in Israel and Cali...

  11. Redbay ambrosia beetle/Laurel wilt: Overview of projects at the USDA-ARS Subtropical Horticulture Research Station

    Science.gov (United States)

    ABSTRACT Laurel wilt, a deadly fungal disease of avocado and other trees in the Lauraceae, is vectored by the redbay ambrosia beetle (Xyleborus glabratus). First detected near Savannah, GA in 2002, the beetle and its obligatory pathogen have since spread to South Carolina and Florida. Currently, t...

  12. Fusarium euwallaceae, a novel species cultivated by a Euwallacea ambrosia beetle that threatens avocado production in Israel and California

    Science.gov (United States)

    Avocado production in Israel and California, USA is facing a serious threat due to damage caused by an invasive Euwallacea ambrosia beetle and a novel Fusarium that it cultivates as a source of food. Adult female beetles possess mandibular mycangia within which they carry the Fusarium symbiont. At l...

  13. The invasive ambrosia beetle Euwallacea fornicates vectors an exotic symbiotic Fusarium species that threatens avocado production in Israel

    Science.gov (United States)

    The invasive ambrosia beetle (Euwallacea fornicatus Eichhoff) was first recorded in Israel in 2009, and it has been shown to vector an exotic fusarial pathogen. Multilocus molecular phylogenetic analyses indicate that the pathogen represents a novel symbiotic Fusarium sp. within Clade 3 of the Fusar...

  14. A pernicious agent affecting avocado in Israel: a novel symbiotic Fusarium sp. associated with the ambrosia beetle Euwallacea fornicatus

    Science.gov (United States)

    Since first recorded in Israel in 2009, the ambrosia beetle, Euwallacea fornicatus Eichhoff, has been shown to vector a fusarial pathogen of avocado (Persea Americana Miller) in its mandibular mycangia. Multilocus molecular phylogenetic analyses indicate the pathogen represents a novel symbiotic Fus...

  15. Effect of Gamma Rays and Salinity on Growth and Chemical Composition of Ambrosia maritima L. Plant

    International Nuclear Information System (INIS)

    This work achieved to study the effects of, mixture of salt 2:2:1 (Na Cl-CaCl2 and Mg SO4), concentration of (0, 2000, 4000 and 6000 ppm). on growth characters, some chemical components and some active ingredients in shoots of Ambrosia maritima plants, at different stages of growth, during two seasons. Pots 30 cm in diameter were filled of sand-loamy soils in appropriate concentration, all pots were irrigated with tap water. The exposed damsisa seeds to gamma rays, doses (0, 20, 40, and 80 Gy) before sowing together with control non irradiated seeds were sown in saline soils (0, 2000, 4000 and 6000 ppm). Soil salinity treatments caused a decrease in plant height, number of leaves, content of damsin, and an increase in fresh weigh, dry weight, total sugars, total chlorophyll, amino acids and ambrosine content. Also, Gamma rays caused an increase in most of growth parameters and most of chemical composition. It was observed that 40 or 80 Gy was more effective. We investigated the combined effect of levels of salinity and doses of radiation used, this interference improve growth parameters and chemical composition in ambrosia maritima plants and caused ascertain the role of gamma irradiation in plants tolerance to soil salinity and alleviation their harmful effect on plants.

  16. Ambrosia Beetle (Coleoptera: Scolytidae) Species, Flight, and Attack on Living Eastern Cottonwood Trees.

    Energy Technology Data Exchange (ETDEWEB)

    Coyle, D R; D.C. Booth: M.S. Wallace

    2005-12-01

    ABSTRACT In spring 2002, ambrosia beetles (Coleoptera: Scolytidae) infested an intensively managed 22-ha tree plantation on the upper coastal plain of South Carolina. Nearly 3,500 scolytids representing 28 species were captured in ethanol-baited traps from 18 June 2002 to 18 April 2004. More than 88% of total captures were exotic species. Five species [Dryoxylon onoharaensum (Murayama), Euwallacea validus (Eichhoff), Pseudopityophthorus minutissimus (Zimmermann), Xyleborus atratus Eichhoff, and Xyleborus impressus Eichhoff]) were collected in South Carolina for the first time. Of four tree species in the plantation, eastern cottonwood, Populus deltoides Bartram, was the only one attacked, with nearly 40% of the trees sustaining ambrosia beetle damage. Clone ST66 sustained more damage than clone S7C15. ST66 trees receiving fertilization were attacked more frequently than trees receiving irrigation, irrigation_fertilization, or controls, although the number of S7C15 trees attacked did not differ among treatments. The study location is near major shipping ports; our results demonstrate the necessity for intensive monitoring programs to determine the arrival, spread, ecology, and impact of exotic scolytids.

  17. Pathogenic microorganisms survival in ambrosiaSobrevivência de micro-organismos patogênicos em ambrósia

    Directory of Open Access Journals (Sweden)

    Cláudio Dias Timm

    2013-09-01

    Full Text Available Ambrosia is a kind of dulce de leche homemade with milk, eggs and sugar. It is usually sold in free markets and it is largely consumed in South America. Food contamination by pathogenic microorganisms can occur during the food processing, in distribution centers, in retail markets or in the consumer’s homes. The aim of this study was to evaluate the survival in ambrosia of main pathogenic microorganisms eventually transmitted by dairy products. Ambrosia fractions were experimentally contaminated with Salmonella enterica subsp. enterica serotype Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes and Staphylococcus aureus. Analysis to evaluate the microorganisms’ viability were made after storage for 0, 1, 2, 3, 5, 10, 20 and 30 days. Salmonella and L. monocytogenes were recovered from all samples during the 30 days of study. E. coli O157:H7 was isolated until the tenth day and S. aureus until the third day. It was demonstrated that important pathogenic microorganisms are able to survive up to 30 days in ambrosia, which makes this product a potential carrier of food-borne diseases. This work is the first study about the possibility of ambrosia transmitting relevant public-health danger pathogenic microorganisms. Ambrosia é um tipo de doce de leite preparado artesanalmente com leite, ovos e açúcar, comumente comercializado em feiras livres e muito consumido na América do Sul. A contaminação de alimentos por microrganismos patogênicos pode ocorrer durante as etapas de processamento, nos centros de distribuição, no mercado varejista ou na casa do consumidor. O trabalho teve como objetivo avaliar a sobrevivência em ambrosia dos principais microrganismos patogênicos eventualmente transmitidos por leite e derivados. Alíquotas de ambrosia foram experimentalmente contaminadas com Salmonella enterica subsp. enterica sorotipo Typhimurium, Escherichia coli O157:H7, Listeria monocytogenes e Staphylococcus aureus. Foram realizadas

  18. Americium, plutonium and uranium contamination and speciation in well waters, streams and atomic lakes in the Sarzhal region of the Semipalatinsk Nuclear Test Site, Kazakhstan

    International Nuclear Information System (INIS)

    New data are reported on the concentrations, isotopic composition and speciation of americium, plutonium and uranium in surface and ground waters in the Sarzhal region of the Semipalatinsk Test Site, and an adjacent area including the settlement of Sarzhal. The data relate to filtered water and suspended particulate from (a) streams originating in the Degelen Mountains, (b) the Tel'kem 1 and Tel'kem 2 atomic craters, and (c) wells on farms located within the study area and at Sarzhal. The measurements show that 241Am, 239,240Pu and 238U concentrations in well waters within the study area are in the range 0.04-87 mBq dm-3, 0.7-99 mBq dm-3, and 74-213 mBq dm-3, respectively, and for 241Am and 239,240Pu are elevated above the levels expected solely on the basis of global fallout. Concentrations in streams sourced in the Degelen Mountains are similar, while concentrations in the two water-filled atomic craters are somewhat higher. Suspended particulate concentrations in well waters vary considerably, though median values are very low, at 0.01 mBq dm-3, 0.08 mBq dm-3 and 0.32 mBq dm-3 for 241Am, 239,240Pu and 238U, respectively. The 235U/238U isotopic ratio in almost all well and stream waters is slightly elevated above the 'best estimate' value for natural uranium worldwide, suggesting that some of the uranium in these waters is of test-site provenance. Redox analysis shows that on average most of the plutonium present in the microfiltered fraction of these waters is in a chemically reduced form (mean 69%; 95% confidence interval 53-85%). In the case of the atomic craters, the proportion is even higher. As expected, all of the americium present appears to be in a reduced form. Calculations suggest that annual committed effective doses to individual adults arising from the daily ingestion of these well waters are in the range 11-42 μSv (mean 21 μSv). Presently, the ground water feeding these wells would not appear to be contaminated with radioactivity from past

  19. Risico’s van introductie van exotische plantensoorten, in het bijzonder uit het geslacht Ambrosia L., via import van zaden voor met name veevoer en vogelvoer

    OpenAIRE

    Denderen, van, A.C.; Tamis, Wil L.M.; Valkenburg

    2010-01-01

    Import van landbouwproducten, in het bijzonder zaden, zijn een belangrijke bron voor de introductie van exotische plantensoorten. In dit artikel wordt ingegaan op twee studies naar het voorkomen van exotische planten, in het bijzonder uit het geslacht Ambrosia, in geïmporteerde partijen zaden. Met name van Alsemambrosia (Ambrosia artemisiifolia) is bekend dat het pollen een sterke hooikoortsreactie kan veroorzaken en derhalve gezondheidsrisico’s met zich meebrengt. In de eerste studie is geke...

  20. Is the recent decrease in airborne Ambrosia pollen in the Milan area due to the accidental introduction of the ragweed leaf beetle Ophraella communa?

    OpenAIRE

    Bonini, Maira; Šikoparija, B.; Prentović, M.; Cislaghi, G; Colombo, P.; Testoni, C.; Grewling, L.; Lommen, Suzanne T. E.; Müller-Schärer, Heinz; M. Smith

    2015-01-01

    This study aims to determine whether a significant decrease in airborne concentrations of Ambrosia pollen witnessed in the north-west of the Province of Milan in Northern Italy could be explained by environmental factors such as meteorology, or whether there is evidence to support the hypothesis that the decrease was related to the presence of large numbers of the oligophagous Ophraella communa leaf beetles that are used as a biological control agent against Ambrosia in other parts of the wor...

  1. Developments in uranium in 1984

    International Nuclear Information System (INIS)

    The same conditions - low prices, inventory liquidations by utilities, and foreign competition - that existed in 1983, continued into 1984. Production exceeded consumption and, as a result, exploration for uranium in the US declined for the sixth straight year. In 1984, an estimated $30 million was spent on uranium exploration, including 2.5 million ft of surface drilling. This drilling was done mainly in the producing areas and in areas of recent discoveries. Production of uranium concentrate declined in 1984, for the fourth straight year, when 15 million lb of uranium oxide (U3O8) were produced. Uranium produced as the result of solution mining and as the by-product of phosphoric acid production accounted for about 35% of the total production in the US. Due to the soft market, numerous mines and 4 mills closed in 1984. Canada continues to dominate the free world's market with the opening of the world's largest uranium production center at Key Lake, Saskatchewan. The decline of the domestic producing industry in 1984 is expected to continue into 1985, and the US will slip into third place in uranium production in the free world. 3 figures, 2 tables

  2. Key Lake spill. Final report

    International Nuclear Information System (INIS)

    On January 5, 1984 contaminated water overflowed a storage reservoir at the Key Lake uranium mill onto the ice on a neighboring lake, into a muskeg area and onto a road. Outflow continued for two days, partially undercutting a retaining dyke. This report concludes the spill was the result of poor operation by the Key Lake Mining Corp.. The environmental impact will be minimal after cleanup. Improvements can be made in the regulatory process, and it is necessary to prepare for possible future mishaps

  3. Czechoslovak uranium

    International Nuclear Information System (INIS)

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

  4. Cigar Lake, an original method for an exceptional deposit

    International Nuclear Information System (INIS)

    In 1976, the discovery of the high grade Deposit at Cluff Lake in the north of the province of Saskatchewan (Canada) opened new prospects in uranium deposits, which in turn quickly led to the discovery of exceptional deposits both in terms of grade (up 10 % in metal uranium) and tonnage (150, 000 tons of metal per deposit and more). Among these deposits are Key Lake, Cigar Lake, Midwest, MacClean, and more recently, Mac Arthur. These discoveries as well as future ones make the north of Saskatchewan the world's greatest and most interesting uranium-producing province. (authors)

  5. Summary on uranium in Canada, 1984

    International Nuclear Information System (INIS)

    Field and laboratory investigations of recently discovered uranium occurrences and deposits have revealed that (a) the mineralization processes that formed the Cigar Lake deposit, Saskatchewan were similar to those reported for the McClean Lake deposit; (b) the recently discovered Boomerang Lake occurrence related to the sub-Thelon unconformity occurs in a geological environment similar to that hosting deposits related to the sub-Athabasca unconformity; (c) additional occurrences of mineralization similar to the Black Sturgeon Lake showing, Ontario, will be restricted to areas containing uraniferous igneous rocks adjacent to ferruginous metavolcanic rocks in areas affected by Keweenawan hydrothermal activity; (d) uranium occurrences in the Otish Basin, Labrador Trough, Central Mineral Belt of Labrador and the Nonacho Basin were formed by epigenetic processes

  6. Flotation of uranium from uranium ores in Canada. Part 1

    International Nuclear Information System (INIS)

    About 150 flotation tests were done on Elliot Lake ore with 15 reagents as collectors in order to screen and choose an attractive collector for uranium flotation. Several variables were studied including pH, conditioning time and mode of collector addition. The tests were done in a Denver or Agitair subaeration cell. The particle size of the ore was kept at 85% below -325 mesh. Three reagents (Kelex 00, TOPO, and cupferron) were identified as having the most promise. The best results were obtained with cupferron, where 93-95% of the uranium was recovered in 25-30% of the mass of original ore. Radium in the tails varied between 5 and 30 pCi/g depending on the mass of uranium floated. Radium was recovered in proportion to uranium in the tests done at neutral pH. The preconcentration results obtained by flotation alone were comparable to those obtained using pyrite flotation and wet high-intensity magnetic separation of uranium. The consumption of cupferron was 4 kg/Mg ore for each flotation stage. This was 10-15 times larger than the collector usage in conventional oxide flotation. This scheme did not require other reagents as depressants, activators or modifiers. Reproducibility was good and similar recoveries were obtained with fresh or old ores, and with distilled or mine water. The selectivity of cupferron for uranium in the ore studied was outstanding

  7. Uranium production

    International Nuclear Information System (INIS)

    The alltime high for uranium concentrate production is expected to be reached in 1980. The average grade of ore fed to process will be up about 10% from last year. Some curtailments in uranium processing were announced, but three new processing plants began production in 1980. The prospects for 1981 are not as encouraging. The continuation of low prices and slow demand for U3O8 are expected to be reflected in a significant reduction in overall production and in the postponement of some plans for expansion and construction of uranium processing facilities. Increases in production capacity will occur when Plateau Resource's 750 TPD mill at Ticaboo, Utah, starts up early next year, and additional production of byproduct uranium is expected from western phosphate operations and from the southern states. These increases in capacity, however, will not offset the cutbacks in uranium processing already in force together with the additional curtailments anticipated during the course of 1981

  8. Uranium enrichment

    International Nuclear Information System (INIS)

    GAO was asked to address several questions concerning a number of proposed uranium enrichment bills introduced during the 100th Congress. The bill would have restructured the Department of Energy's uranium enrichment program as a government corporation to allow it to compete more effectively in the domestic and international markets. Some of GAO's findings discussed are: uranium market experts believe and existing market models show that the proposed DOE purchase of a $750 million of uranium from domestic producers may not significantly increase production because of large producer-held inventories; excess uranium enrichment production capacity exists throughout the world; therefore, foreign producers are expected to compete heavily in the United States throughout the 1990s as utilities' contracts with DOE expire; and according to a 1988 agreement between DOE's Offices of Nuclear Energy and Defense Programs, enrichment decommissioning costs, estimated to total $3.6 billion for planning purposes, will be shared by the commercial enrichment program and the government

  9. Uranium: Prices, rise, then fall

    International Nuclear Information System (INIS)

    Uranium prices hit eight-year highs in both market tiers, $16.60/lb U3O8 for non-former Soviet Union (FSU) origin and $15.50 for FSU origin during mid 1996. However, they declined to $14.70 and $13.90, respectively, by the end of the year. Increased uranium prices continue to encourage new production and restarts of production facilities presently on standby. Australia scrapped its open-quotes three-mineclose quotes policy following the ouster of the Labor party in a March election. The move opens the way for increasing competition with Canada's low-cost producers. Other events in the industry during 1996 that have current or potential impacts on the market include: approval of legislation outlining the ground rules for privatization of the US Enrichment Corp. (USEC) and the subsequent sales of converted Russian highly enriched uranium (HEU) from its nuclear weapons program, announcement of sales plans for converted US HEU and other surplus material through either the Department of Energy or USEC, and continuation of quotas for uranium from the FSU in the United States and Europe. In Canada, permitting activities continued on the Cigar Lake and McArthur River projects; and construction commenced on the McClean Lake mill

  10. Feasibility study of the dissolution rates of uranium ore dust, uranium concentrates and uranium compounds in simulated lung fluid

    International Nuclear Information System (INIS)

    A flow-through apparatus has been devised to study the dissolution in simulated lung fluid of aerosol materials associated with the Canadian uranium industry. The apparatus has been experimentally applied over 16 day extraction periods to approximately 2g samples of < 38um and 53-75um particle-size fractions of both Elliot Lake and Mid-Western uranium ores. The extraction of uranium-238 was in the range 24-60% for these samples. The corresponding range for radium-226 was 8-26%. Thorium-230, lead-210, polonium-210, and thorium-232 were not significantly extracted. It was incidentally found that the elemental composition of the ores studied varies significantly with particle size, the radionuclide-containing minerals and several extractable stable elements being concentrated in the smaller size fraction. Samples of the refined compounds uranium dioxide and uranium trioxide were submitted to similar 16 day extraction experiments. Approximately 0.5% of the uranium was extracted from a 0.258g sample of unsintered (fluid bed) uranium dioxide of particle size < 38um. The corresponding figure for a 0.292g sample of uranium trioxide was 97%. Two aerosol samples on filters were also studied. Of the 88ug uranium initially measured on stage 2 of a cascade impactor sample collected from the yellow cake packing area of an Elliot Lake mill, essentially 100% was extracted over a 16 day period. The corresponding figure for an open face filter sample collected in a fuel fabrication plant and initially measured at 288ug uranium was approximately 3%. Recommendations are made with regard to further work of a research nature which would be useful in this area. Recommendations are also made on sampling methods, analytical methods and extraction conditions for various aerosols of interest which are to be studied in a work of broader scope designed to yield meaningful data in connection with lung dosimetry calculations

  11. Dianchi Lake

    OpenAIRE

    Gipouloux, François

    2012-01-01

    This photo is taken in Dianchi lake of Kunming city. After 1970, the industrial zones and farmland areas around Kunming evacuated waste water into Dianchi Lake, resulting in a significant growth of cyanobacteria and serious eutrophication in Dianchi Lake. Although the Kunming city government has been actively trying to solve the problem of pollution in Dianchi Lake, in order to significantly improve water quality, the lake is still at a pollution level far below the level of drinkable water.

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

    International Nuclear Information System (INIS)

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

  13. Tramp uranium

    International Nuclear Information System (INIS)

    Many utilities have implemented a no leaker philosophy for fuel performance and actively pursue removing leaking fuel assemblies from their reactor cores whenever a leaking fuel assembly is detected. Therefore, the only source for fission product activity in the RCS when there are no leaking fuel assemblies is tramp uranium. A technique has been developed that strips uranium impurities from ZrCl4. Unless efforts are made to remove natural uranium impurities from reactor materials, the utilities will not be able to reduce the RCS specific 131I activity in PWRs to below the lower limit of ∼1.0 x 10-4 μCi/g

  14. Geochemical and microbiological processes in sediments and in the sediment-water boundary layer of acid lakes in mining landscapes

    International Nuclear Information System (INIS)

    Subjects: Applications and characterisation of sulphate-reducing bacteria in acid lakes in abandanod uranium and lignite mines; biological analysis of the lakes and their sediments; analytical methods and biogeochemical analysis of mining lakes, technical deacidification experiments, balances and models of mass flow in lakes and sediments of mining landscapes

  15. Discordant phylogenies suggest repeated host shifts in the Fusarium-Euwallacea ambrosia beetle mutualism.

    Science.gov (United States)

    O'Donnell, Kerry; Sink, Stacy; Libeskind-Hadas, Ran; Hulcr, Jiri; Kasson, Matthew T; Ploetz, Randy C; Konkol, Joshua L; Ploetz, Jill N; Carrillo, Daniel; Campbell, Alina; Duncan, Rita E; Liyanage, Pradeepa N H; Eskalen, Akif; Na, Francis; Geiser, David M; Bateman, Craig; Freeman, Stanley; Mendel, Zvi; Sharon, Michal; Aoki, Takayuki; Cossé, Allard A; Rooney, Alejandro P

    2015-09-01

    The mutualism between xyleborine beetles in the genus Euwallacea (Coleoptera: Curculionidae: Scolytinae) and members of the Ambrosia Fusarium Clade (AFC) represents one of 11 known evolutionary origins of fungiculture by ambrosia beetles. Female Euwallacea beetles transport fusarial symbionts in paired mandibular mycangia from their natal gallery to woody hosts where they are cultivated in galleries as a source of food. Native to Asia, several exotic Euwallacea species were introduced into the United States and Israel within the past two decades and they now threaten urban landscapes, forests and avocado production. To assess species limits and to date the evolutionary diversification of the mutualists, we reconstructed the evolutionary histories of key representatives of the Fusarium and Euwallacea clades using maximum parsimony and maximum likelihood methods. Twelve species-level lineages, termed AF 1-12, were identified within the monophyletic AFC and seven among the Fusarium-farming Euwallacea. Bayesian diversification-time estimates placed the origin of the Euwallacea-Fusarium mutualism near the Oligocene-Miocene boundary ∼19-24 Mya. Most Euwallacea spp. appear to be associated with one species of Fusarium, but two species farmed two closely related fusaria. Euwallacea sp. #2 in Miami-Dade County, Florida cultivated Fusarium spp. AF-6 and AF-8 on avocado, and Euwallacea sp. #4 farmed Fusarium ambrosium AF-1 and Fusarium sp. AF-11 on Chinese tea in Sri Lanka. Cophylogenetic analyses indicated that the Euwallacea and Fusarium phylogenies were largely incongruent, apparently due to the beetles switching fusarial symbionts (i.e., host shifts) at least five times during the evolution of this mutualism. Three cospeciation events between Euwallacea and their AFC symbionts were detected, but randomization tests failed to reject the null hypothesis that the putative parallel cladogenesis is a stochastic pattern. Lastly, two collections of Euwallacea sp. #2 from Miami

  16. 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

  17. Uranium Market

    International Nuclear Information System (INIS)

    The main fuel component for commercial nuclear power reactors is Uranium. When compared to fossil fuels, it has a competitive edge due to factors such as economics and environmental conditions and in particular due to its international market availability. Uranium world demand reached to 67 320 tU in 2004, which was covered with additional sources. To project the uranium markets behavior requires to know and to accept some conditions tied to the demand, such as the electrical world consumption, the greenhouse effect; water desalination, production of hydrogen, industrial heat, the innovative development of nuclear reactors, and the average time of 10 years between the beginning of exploration programs and definition of deposits, which it owes mainly to the difficulty of achieving the legal, environmental and local community authorizations, to open new mining centers. Uranium market future projections, made by IAEA experts in 2001, that considered middle and high demand scenarios, concluded that cumulatively to year 2050, with regard to demand it will be required 5.4 and 7.6 million tons of uranium respectively, and with regard to the uranium price, it should present a sustained increase. In the last years the situation of the uranium market has changed dramatically. In August 2006 the price of uranium reached to USD 106/kgU in the spot market, surpassing all the made projections. The increase in price that has stayed in rise in the last five years is reactivating the prospection and exploration efforts anywhere in the world, and competition between prospective areas of potential resources mainly in less explored territories

  18. Uranium, depleted uranium, biological effects

    International Nuclear Information System (INIS)

    Physicists, chemists and biologists at the CEA are developing scientific programs on the properties and uses of ionizing radiation. Since the CEA was created in 1945, a great deal of research has been carried out on the properties of natural, enriched and depleted uranium in cooperation with university laboratories and CNRS. There is a great deal of available data about uranium; thousands of analyses have been published in international reviews over more than 40 years. This presentation on uranium is a very brief summary of all these studies. (author)

  19. Uranium loans

    International Nuclear Information System (INIS)

    When NUEXCO was organized in 1968, its founders conceived of a business based on uranium loans. The concept was relatively straightforward; those who found themselves with excess supplies of uranium would deposit those excesses in NUEXCO's open-quotes bank,close quotes and those who found themselves temporarily short of uranium could borrow from the bank. The borrower would pay interest based on the quantity of uranium borrowed and the duration of the loan, and the bank would collect the interest, deduct its service fee for arranging the loan, and pay the balance to those whose deposits were borrowed. In fact, the original plan was to call the firm Nuclear Bank Corporation, until it was discovered that using the word open-quotes Bankclose quotes in the name would subject the firm to various US banking regulations. Thus, Nuclear Bank Corporation became Nuclear Exchange Corporation, which was later shortened to NUEXCO. Neither the nuclear fuel market nor NUEXCO's business developed quite as its founders had anticipated. From almost the very beginning, the brokerage of uranium purchases and sales became a more significant activity for NUEXCO than arranging uranium loans. Nevertheless, loan transactions have played an important role in the international nuclear fuel market, requiring the development of special knowledge and commercial techniques

  20. Advances in the exploration model for Athabasca unconformity uranium deposits

    International Nuclear Information System (INIS)

    This paper covers the genetic model of ore formation and exploration techniques Uranerz Exploration and Mining is presently using to explore for unconformity uranium deposits in the deeper parts of the Athabasca Basin. The main objectives of this paper are: 1) to present a genetic model for unconformity uranium deposits which is being used in our current exploration strategy, and 2) to present the sequence of exploration techniques used by Uranerz to explore for uranium in areas of the Athabasca Basin with up to 1000 m of sandstone cover. The Athabasca unconformity deposits are located in northern Saskatchewan, Canada. Within the Precambrian Athabasca Basin, exploration companies have discovered 18 uranium deposits. These contain more than 500 million kilograms of uranium, with average grades ranging from 0.3 to 12%. Uranerz discovered the Key Lake deposits in 1975, currently the largest and richest open pit uranium mine in the world. Uranerz also holds interests in the Rabbit Lake, Midwest Lake and McArthur River deposits, all in Saskatchewan, and is also actively exploring for uranium worldwide. The first discovery in the eastern Athabasca Basin was in 1968 at Rabbit Lake, followed by Key Lake in 1975. Both deposits had surficial indicators, such as radioactive boulders, strong geochemical anomalies in the surrounding lakes and swamps, and well-defined geophysical signatures. After the Key Lake discovery, an exploration model was devised which incorporated the underlying graphitic horizon and its strong electro-magnetic signature. Since then, there have been numerous new discoveries made by systematically drilling along these electro-magnetic conductors. The advancements in geophysical and geochemical techniques have led to discoveries at increasing depths. In 1988, the McArthur River deposit was discovered at a depth of 500 m. (author). 6 refs

  1. Chemical composition and antibacterial activity of the essential oil of Ambrosia peruviana Willd. from Venezuelan plains

    Directory of Open Access Journals (Sweden)

    Carlos A. Yánez C.

    2011-08-01

    Full Text Available In Venezuela, are currently exploring new sources of natural antibacterial agents, due to increased bacterial resistance, including essential oils derived from plants. For this reason in the present study we determined the chemical composition of essential oil obtained from leaves collected on Ambrosia peruviana Willd Guasdualito, Apure State, Venezuela. The volatile compounds were isolated by hydrodistillation in a Clevenger trap and then subjected to qualitative analysis and quantitative by gas chromatography-mass spectrometry (GC / MS on an HP GC-MS System, model 5973, finding as the major compound gamma-curcumeno (23.99% followed by curcumeno-ar (14.08%, bornyl acetate (10.35%, camphor (5.03% and epoxide oximene (4.79%. The antibacterial activity of essential oil by the agar diffusion method with discs against Staphylococcus aureus, Enterococcus faecalis, Escherichia coli, Klebsiella pneumoniae, Salmonella typhi and Pseudomonas aeruginosa showed activity against S. aureus, E. faecalis, E. coli and S. Typhi, with MIC values of 350-500 micrograms/ mL. This research represents the first report of antibacterial activity of A. peruviana.

  2. Minireview: importance of herbicide-tolerant sunflower hybrids in suppressing common ragweed (Ambrosia artemisiifolia pollen production

    Directory of Open Access Journals (Sweden)

    Peter Reisinger

    2014-01-01

    Full Text Available Common ragweed (Ambrosia artemisiifolia is the number one weed in Hungary: it covers ca. 5% of the arable land, causing huge losses in row crops, especially in sunflowers. In addition, because of the high allergenicity of its pollen, common ragweed is a heavy burden on the health care system. This minireview discusses the importance of use of herbicide-tolerant sunflower hybrids in eliminating common ragweed from sunflower fields, with special emphasis on the efficacy of common ragweed control of two acetolactate-synthase inhibitor postemergence herbicides (imazamox and tribenuron methyl in several sunflower hybrids that carry the resistance gene against such herbicides. Common ragweed control by these herbicides was excellent: they suppressed the growth of the weed plant until the canopy closure of the crop (8-leaf stage. Common ragweed plants germinating after this date were unable to compete with the crop: although they survived, they remained small (ca. 70% reduction in height, produced ca. 90% less male inflorescences (source of the allergenic pollen, and caused no significant reduction in the crop yield. In order to stop the seed production by the few late-germinating weed plants we recommend a mechanical common measure (row-cultivator in late August.

  3. Yeast Associated with the Ambrosia Beetle, Platypus koryoensis, the Pest of Oak Trees in Korea.

    Science.gov (United States)

    Yun, Yeo Hong; Suh, Dong Yeon; Yoo, Hun Dal; Oh, Man Hwan; Kim, Seong Hwan

    2015-12-01

    Oak tree death caused by symbiosis of an ambrosia beetle, Platypus koryoensis, and an ophiostomatoid filamentous fungus, Raffaelea quercus-mongolicae, has been a nationwide problem in Korea since 2004. In this study, we surveyed the yeast species associated with P. koryoensis to better understand the diversity of fungal associates of the beetle pest. In 2009, a total of 195 yeast isolates were sampled from larvae and adult beetles (female and male) of P. koryoensis in Cheonan, Goyang, and Paju; 8 species were identified by based on their morphological, biochemical and molecular analyses. Meyerozyma guilliermondii and Candida kashinagacola were found to be the two dominant species. Among the 8 species, Candida homilentoma was a newly recorded yeast species in Korea, and thus, its mycological characteristics were described. The P. koryoensis symbiont R. quercusmongolicae did not show extracelluar CM-cellulase, xylanase and avicelase activity that are responsible for degradation of wood structure; however, C. kashinagacola and M. guilliermondii did show the three extracellular enzymatic activities. Extracelluar CM-cellulase activity was also found in Ambrosiozyma sp., C. homilentoma, C. kashinagacola, and Candida sp. Extracelluar pectinase activity was detected in Ambrosiozyma sp., C. homilentoma, Candida sp., and M. guilliermondii. All the 8 yeast species displayed compatible relationships with R. quercus-mongolicae when they were co-cultivated on yeast extract-malt extract plates. Overall, our results demonstrated that P. koryoensis carries the yeast species as a symbiotic fungal associate. This is first report of yeast diversity associated with P. koryoensis. PMID:26839506

  4. Erhöhte Frosttoleranz und vorteilhafte Keimeigenschaften in europäischen Ambrosia artemisiifolia Populationen

    Directory of Open Access Journals (Sweden)

    Leiblein-Wild, Marion Carmen

    2014-06-01

    Full Text Available Germination characteristics and frost tolerance of seedlings are crucial parameters for establishment and invasion success of plants. Within this study, we investigated germination characteristics of Ambrosia artemisiifolia L. populations from native and invasive ranges. We determined germination rates and speed under different temperature conditions. From these parameters we calculated minimal, optimal, and maximal temperature for germination. We also investigated the frost tolerance of seedlings. The European populations were characterized by a higher fitness with higher germination rates and germination speed, increased biomass and higher frost tolerance of seedlings. Furthermore, the temperature niche width for germination was significantly broader for the European populations. The increased frost tolerance of the European populations might allow germination earlier in the year which may subsequently lead to higher biomass allocation – due to a longer growing period – and result in higher pollen and seed production. The increase in germination rates, germination speed and seedling frost tolerance might result in a higher fitness of the European populations which may facilitate further successful invasion and sharpen the existing problems.

  5. Effects of seed traits variation on seedling performance of the invasive weed, Ambrosia artemisiifolia L.

    Science.gov (United States)

    Ortmans, William; Mahy, Grégory; Monty, Arnaud

    2016-02-01

    Seedling performance can determine the survival of a juvenile plant and impact adult plant performance. Understanding the factors that may impact seedling performance is thus critical, especially for annuals, opportunists or invasive plant species. Seedling performance can vary among mothers or populations in response to environmental conditions or under the influence of seed traits. However, very few studies have investigated seed traits variations and their consequences on seedling performance. Specifically, the following questions have been addressed by this work: 1) How the seed traits of the invasive Ambrosia artemisiifolia L. vary among mothers and populations, as well as along the latitude; 2) How do seed traits influence seedling performance; 3) Is the influence on seedlings temperature dependent. With seeds from nine Western Europe ruderal populations, seed traits that can influence seedling development were measured. The seeds were sown into growth chambers with warmer or colder temperature treatments. During seedling growth, performance-related traits were measured. A high variability in seed traits was highlighted. Variation was determined by the mother identity and population, but not latitude. Together, the temperature, population and the identity of the mother had an effect on seedling performance. Seed traits had a relative impact on seedling performance, but this did not appear to be temperature dependent. Seedling performance exhibited a strong plastic response to the temperature, was shaped by the identity of the mother and the population, and was influenced by a number of seed traits.

  6. Life history trait differentiation and local adaptation in invasive populations of Ambrosia artemisiifolia in China.

    Science.gov (United States)

    Li, Xiao-Meng; She, Deng-Ying; Zhang, Da-Yong; Liao, Wan-Jin

    2015-03-01

    Local adaptation has been suggested to play an important role in range expansion, particularly among invasive species. However, the extent to which local adaptation affects the success of an invasive species and the factors that contribute to local adaptation are still unclear. This study aimed to investigate a case of population divergence that may have contributed to the local adaptation of invasive populations of Ambrosia artemisiifolia in China. Common garden experiments in seven populations indicated clinal variations along latitudinal gradients, with plants from higher latitudes exhibiting earlier flowering and smaller sizes at flowering. In reciprocal transplant experiments, plants of a northern Beijing origin produced more seeds at their home site than plants of a southern Wuhan origin, and the Wuhan-origin plants had grown taller at flowering than the Beijing-origin plants in Wuhan, which is believed to facilitate pollen dispersal. These results suggest that plants of Beijing origin may be locally adapted through female fitness and plants from Wuhan possibly locally adapted through male fitness. Selection and path analysis suggested that the phenological and growth traits of both populations have been influenced by natural selection and that flowering time has played an important role through its direct and indirect effects on the relative fitness of each individual. This study evidences the life history trait differentiation and local adaptation during range expansion of invasive A. artemisiifolia in China. PMID:25362583

  7. Thermal, mechanical and chemical control of ragweed (Ambrosia artemisiifolia in different habitats

    Directory of Open Access Journals (Sweden)

    Sölter, Ulrike

    2014-02-01

    Full Text Available A small plot field experiment with transplanted ragweed (Ambrosia artemisiifolia into gravel and grassland and a large scale field experiment on a roadside banquette in Brandenburg with a natural ragweed infestation were carried out. Thermal control treatments were hot air (gravel and grassland and hot water (roadside and flaming, the mechanical treatment was mowing and the chemical treatment was the application of the herbicide combination MCPA and Dicamba. The gravel and grassland experiment was conducted at two growth stages of ragweed (BBCH 16-18 and 22-29, at the roadside ragweed was at BBCH 50-65. Dry matter yield of ragweed was assessed 9 weeks after the treatments were conducted in gravel and grassland and 4 weeks after the treatment at the roadside. In gravel and grassland the best eradication at both growth stages by thermal control was achieved by hot air in comparison to the untreated plots (significant at P <0.05. And at the roadside significant lower dry matter was determined by hot water and flaming in comparison to the untreated plots (significant at P <0.05. The results of these experiments demonstrated the efficiency of thermal control methods based on hot air and hot water as an alternative to herbicide control and mowing in habitats where herbicide application is not allowed or mowing gives no sufficient eradication results, like on roadside banquettes.

  8. Uranium resources and uranium supply

    International Nuclear Information System (INIS)

    The availability of natural uranium is currently considered unproblematic. Out of concern about the sufficient availability of uranium, an international working group of OECD-NEA, in which the Federal Office for Geosciences and Resources (BGR) participates as a German partner, has conducted analyses of uranium availability since 1965. Its findings are published biannually in the so-called 'Red Book', 'Uranium, Resources, Production, and Demand'. Changes in the political situation worldwide have profoundly influenced the military importance of uranium and thus also greatly improved its accessibility. As a consequence, there was a decline in production in the nineties from approx. 57,000 t of U in 1989 to, at present (2001), approx. 35,000 t annually. Estimates of the worldwide requirement of natural uranium in 2015 range between approx. 55,000 t and 80,000 t of U, because of the unforeseeable extent of the use of nuclear power, as against approx. 63,000 t of U in 2001. The most recent statistics published in the 1999 Red Bock show low-cost reserves (up to Dollar 40 per kg of U) of 1325 million t, and 2234 t of uranium at extraction costs of up to t Dollar 80 per kg. This indicates a statistical range of reserves of approx. 35 years. It should be noted that these figures are snapshots of a dynamic system. A resumption of extensive exploration and technical developments could greatly influence the resource situation. In the nineties, for instance, there is a net increase in uranium reserves of approx. 700,000 t of U as a consequence of exploration activities. (orig.)

  9. Uranium and thorium deposits of Northern Ontario

    International Nuclear Information System (INIS)

    This, the second edition of the uranium-thorium deposit inventory, describes briefly the deposits of uranium and/or thorium in northern Ontario, which for the purposes of this circular is defined as that part of Ontario lying north and west of the Grenville Front. The most significant of the deposits described are fossil placers lying at or near the base of the Middle Precambrian Huronian Supergroup. These include the producing and past-producing mines of the Elliot Lake - Agnew Lake area. Also included are the pitchblende veins spatially associated with Late Precambrian (Keweenawan) diabase dikes of the Theano Point - Montreal River area. Miscellaneous Early Precambrian pegmatite, pitchblende-coffinite-sulphide occurrences near the Middle-Early Precambrian unconformity fringing the Lake Superior basin, and disseminations in diabase, granitic rocks, alkalic complexes and breccias scattered throughout northern Ontario make up the rest of the occurrences

  10. Uranium mining

    International Nuclear Information System (INIS)

    Full text: The economic and environmental sustainability of uranium mining has been analysed by Monash University researcher Dr Gavin Mudd in a paper that challenges the perception that uranium mining is an 'infinite quality source' that provides solutions to the world's demand for energy. Dr Mudd says information on the uranium industry touted by politicians and mining companies is not necessarily inaccurate, but it does not tell the whole story, being often just an average snapshot of the costs of uranium mining today without reflecting the escalating costs associated with the process in years to come. 'From a sustainability perspective, it is critical to evaluate accurately the true lifecycle costs of all forms of electricity production, especially with respect to greenhouse emissions, ' he says. 'For nuclear power, a significant proportion of greenhouse emissions are derived from the fuel supply, including uranium mining, milling, enrichment and fuel manufacture.' Dr Mudd found that financial and environmental costs escalate dramatically as the uranium ore is used. The deeper the mining process required to extract the ore, the higher the cost for mining companies, the greater the impact on the environment and the more resources needed to obtain the product. It is clear that there is a strong sensitivity of energy and water consumption and greenhouse emissions to ore grade, and that ore grades are likely to continue to decline gradually in the medium to long term. These issues are critical to the current debate over nuclear power and greenhouse emissions, especially with respect to ascribing sustainability to such activities as uranium mining and milling. For example, mining at Roxby Downs is responsible for the emission of over one million tonnes of greenhouse gases per year and this could increase to four million tonnes if the mine is expanded.'

  11. Uranium enrichment

    International Nuclear Information System (INIS)

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

  12. 芳香石豆兰的繁殖生态学%Reproductive ecology of Bulbophyllum ambrosia (Orchidaceae)

    Institute of Scientific and Technical Information of China (English)

    陈玲玲; 高江云

    2011-01-01

    芳香石豆兰(Bulbophyllum ambrosia)是分布于我国南方石灰岩山热带季节性雨林中的一种常见附生兰科植物,附着生长于岩石或树干上,野外监测发现其自然不结实.对芳香石豆兰繁殖生态学的研究表明,不同于石豆兰属其他具有蝇类传粉综合征的种类,其花具有香味和花蜜,中华蜜蜂(Apis cerana cerana)是芳香石豆兰唯一的有效传粉者,具有较高的访问频率,自然种群中有较高的花粉块移出率和柱头花粉块沉降率,在中华蜜蜂的传粉过程中,芳香石豆兰铰链结构的唇瓣起着重要作用.人工授粉试验表明,芳香石豆兰自交授粉不结实,异交授粉结实率达90%以上,芳香石豆兰为自交不亲和的繁育系统.芳香石豆兰具有较强的克隆生长能力,同一个体花期内有大量的花同时开放,其传粉者中华蜜蜂平均单次访花(4.29±0.40)朵(n=66),造成了严重的同株异花传粉.芳香石豆兰附生于石灰岩山顶岩石或树干上,种群密度较低,使得不同个体之间花粉交流困难,自交不亲和的特性导致了芳香石豆兰自然不结实.本研究结果为开展芳香石豆兰的有效保护提供了依据.%Aims Bulbophyllum ambrosia is an epiphytic orchid growing on rocks and trees in limestone seasonal rainforests and is commonly distributed in southern China. We found no fruit set of B. ambrosia during long-term monitoring of species diversity, reproductive phenology and pollinators of local orchid species in Green Stone Forest Park. Our objective was to determine barriers to fruit set in B. ambrosia.Methods Flowering phenology and natural fruit-set were monitored once a week for three years. Floral morphology was studied during flowering time. We also investigated the rate of pollinia removal and deposition over two flowering seasons. To determine the self-compatibility system, different hand-pollination treatments were conducted over three years at the study site. We also

  13. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    Directory of Open Access Journals (Sweden)

    Petre GÂŞTESCU

    2009-06-01

    Full Text Available Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes, studies lake biotopes, and biological limnology (the biology of lakes, studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904, which focuses on the geology physics, chemistry and biology of lakes. He was also author of the first textbook of limnology, Handbuch der Seenkunde: allgemeine Limnologie,(1901. Since both the lake biotope and its biohydrocoenosis make up a single whole, the lake and lakes, respectively, represent the most typical systems in nature. They could be called limnosystems (lacustrine ecosystems, a microcosm in itself, as the American biologist St.A. Forbes put it (1887.

  14. Uranium bombs

    Science.gov (United States)

    DeGroot, Gerard

    2009-11-01

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

  15. LIMNOLOGY, LAKE BASINS, LAKE WATERS

    OpenAIRE

    Petre GÂŞTESCU

    2009-01-01

    Limnology is a border discipline between geography, hydrology and biology, and is also closely connected with other sciences, from it borrows research methods. Physical limnology (the geography of lakes), studies lake biotopes, and biological limnology (the biology of lakes), studies lake biocoenoses. The father of limnology is the Swiss scientist F.A. Forel, the author of a three-volume entitled Le Leman: monographie limnologique (1892-1904), which focuses on the geology physics, chemistry a...

  16. Uranium separations using extraction chromatography

    International Nuclear Information System (INIS)

    In the analysis of environmental samples for uranium and thorium pollutants and at natural levels for the dating of geological samples there was felt a need to develop better uranium and thorium, separation procedures to replace the established anion exchange method used at AEA Technology plc. This was the first aim of the PhD research. Separation of uranium from thorium prior to measurement of the isotopes by alpha spectrometry was necessary due to the similar alpha energies of 234U and 230Th. TRU and UTEVA extraction chromatography resins (EIChroM Industries) were investigated as potential replacements to the anion exchange separation method. The resins are claimed by EIChroM to offer the advantage of providing an actinide specific separation while reducing the separation time from 2 to 0.5 days; the volume of acidic waste produced by a factor of 3, therefore, the cost of analysis was reduced. A uranium and thorium separation procedure using the UTEVA extraction chromatography resin was developed. The uranium and thorium were sorbed by the UTEVA resin from 2M nitric acid. The thorium was then eluted from the resin with 5M hydrochloric acid and the uranium with 0.02M hydrochloric acid. The separation procedure was then evaluated using uraninite ore, coral, granite and lake sediment reference materials. The uranium and thorium concentrations and the 234U/238U and 230Th/234U activity ratio values determined for the reference material were in good agreement with certified values. The presence of plutonium was found to interfere with the measurement of uranium and thorium by alpha spectrometry. This was due to the similar alpha energies of uranium, thorium and plutonium. The co-elution of plutonium with uranium and thorium from the UTEVA resin was prevented by the inclusion of a reduction step using iron (II) sulphamate. The resulting plutonium (III) was not retained by the UTEVA column. The chemical recoveries for the procedure were similar to those for anion

  17. 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

  18. Climate inferences between paleontological, geochemical, and geophysical proxies in Late Pleistocene lacustrine sediments from Summer Lake, Oregon, western Great Basin

    Science.gov (United States)

    Heaton, Eric; Thompson, Greg; Negrini, Rob; Wigand, Peter

    2016-04-01

    Paleontological, geochemical, and geophysical data from western Great Basin pluvial Summer Lake, Oregon have established a high resolution paleoclimate record during the late Pleistocene Mono Lake Excursion (~34.75 ka), Dansgaard-Oeschger interstadials 6-8, and the end of Heinrich Even 4 (~38 ka). Proxies of grain-size, magnetic susceptibility, carbon/nitrogen ratio, ostracode analysis and palynology from a depocenter core show new results with improved age control regarding high amplitude, high frequency changes in lake level, lake temperature, and regional precipitation and temperature which correspond directly with colder/warmer and respectively drier/wetter climates as documented with Northern Atlantic Greenland ice core data. Results from geophysical and geochemical analysis, and the presence of ostracode Cytherissa lacustris consistently demonstrate the correspondence of low lake conditions and colder water temperatures during Dansgaard-Oeschger stadials and the Mono Lake Excursion. The opposite holds true during interstadials. Smaller grain size, increases in carbon/nitrogen ratio and consistent absence of C. lacustris suggest periods of increased discharge into the lake, increased lake level, and warmer water temperatures. Warmer/wetter climate conditions are confirmed during interstadials 7 and 8 from pollen analysis. Existence of Atriplex, Rosaceae, Chrysothamnus and Ambrosia, and pollen ratios of Juniperus/Dip Pinus and (Rosaceae+Atriplex+Poaceae+Chrysothamnus+Ambrosia)/(Pinus+Picea+T. mertensiana+Sarcobatus) suggest warmer/wetter semi-arid woodland conditions during interstadials 7 and 8. This contrasts with absences in these pollens and pollen ratios indicating colder/drier continental montane woodland conditions during stadials and the Mono Lake Excursion. Increases in Juniper/Dip Pinus ratio suggest a warmer/wetter climate during interstadial 6 however additional proxies do not demonstrate comparative warmer/wetter climate, deeper lake level or

  19. Ozone affects pollen viability and NAD(P)H oxidase release from Ambrosia artemisiifolia pollen

    Energy Technology Data Exchange (ETDEWEB)

    Pasqualini, Stefania, E-mail: spas@unipg.it [Department of Applied Biology, University of Perugia, Perugia (Italy); Tedeschini, Emma; Frenguelli, Giuseppe [Department of Applied Biology, University of Perugia, Perugia (Italy); Wopfner, Nicole; Ferreira, Fatima [Department of Molecular Biology, CD Laboratory for Allergy Diagnosis and Therapy, University of Salzburg, Salzburg (Austria); D' Amato, Gennaro [Division of Respiratory and Allergic Diseases, ' A. Cardarelli' High Speciality Hospital, Naples (Italy); Ederli, Luisa [Department of Applied Biology, University of Perugia, Perugia (Italy)

    2011-10-15

    Air pollution is frequently proposed as a cause of the increased incidence of allergy in industrialised countries. We investigated the impact of ozone (O{sub 3}) on reactive oxygen species (ROS) and allergen content of ragweed pollen (Ambrosia artemisiifolia). Pollen was exposed to acute O{sub 3} fumigation, with analysis of pollen viability, ROS and nitric oxide (NO) content, activity of nicotinamide adenine dinucleotide phosphate (NAD[P]H) oxidase, and expression of major allergens. There was decreased pollen viability after O{sub 3} fumigation, which indicates damage to the pollen membrane system, although the ROS and NO contents were not changed or were only slightly induced, respectively. Ozone exposure induced a significant enhancement of the ROS-generating enzyme NAD(P)H oxidase. The expression of the allergen Amb a 1 was not affected by O{sub 3}, determined from the mRNA levels of the major allergens. We conclude that O{sub 3} can increase ragweed pollen allergenicity through stimulation of ROS-generating NAD(P)H oxidase. - Highlights: > O{sub 3} reduces the viability of ragweed pollen. > ROS and allergens of ragweed pollen were not affected by O{sub 3} exposure. > O{sub 3} enhances the activity of the ROS-generating enzyme NAD(P)H oxidase. > O{sub 3} increases ragweed pollen allergenicity through NAD(P)H-oxidase stimulation. - This study focuses on the effects of the atmospheric pollutant ozone on ROS content and NAD(P)H oxidase activity of ragweed pollen grains.

  20. Risico’s van introductie van exotische plantensoorten, in het bijzonder uit het geslacht Ambrosia L., via import van zaden voor met name veevoer en vogelvoer

    NARCIS (Netherlands)

    Denderen, van Daniël P.D.; Tamis, Wil L.M.; Valkenburg, van Johan L.C.H.

    2010-01-01

    Import van landbouwproducten, in het bijzonder zaden, zijn een belangrijke bron voor de introductie van exotische plantensoorten. In dit artikel wordt ingegaan op twee studies naar het voorkomen van exotische planten, in het bijzonder uit het geslacht Ambrosia, in geïmporteerde partijen zaden. Met n

  1. Abundance in Persea americana of the Redbay Ambrosia Beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae), Vector of Laurel Wilt: A Case of Intra-guild Competition?

    Science.gov (United States)

    The redbay ambrosia beetle, Xyleborus glabratus is a pest of plant species in the Lauraceae, including Persea borbonia, P. pallustris, P. americana, and others. Xyleborus glabratus infestation levels in P. borbonia maintain a high proportion compared to other species, such as Xylosandrus crassiuscu...

  2. Association of the symbiotic fungi Fusarium euwallaceae, Graphium sp. and Acremonium sp., with the ambrosia beetle Euwallacea nr. fornicatus in avocado

    Science.gov (United States)

    The ambrosia beetle, Euwallacea nr. fornicatus (Coleoptera:Scolytinae), is a new invasive species to Israel. To date, the beetle has been recorded from 48 tree species representing 25 plant families. Amongst the most affected are avocado, castor-bean and box elder. Isolations from beetle heads revea...

  3. Evaluation of commercial formulations of entomopathogenic fungi to manage the redbay ambrosia beetle, vector of Laurel wilt, a lethal disease affecting avocados in Florida

    Science.gov (United States)

    The redbay ambrosia beetle (RAB), Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae) vectors the fungal pathogen, Raffaelea lauricola, which causes laurel wilt (LW), a lethal disease of trees in the family Lauraceae, including the most commercially important crop in this family, avocado, Pe...

  4. An Asian ambrosia beetle Euwallacea fornicatus and its novel symbiotic fungus Fusarium sp. pose a serious threat to the Israeli avocado industry

    Science.gov (United States)

    The ambrosia beetle Euwallacea fornicatus Einchoff was first recorded in Israel in 2009. A novel unnamed symbiotic species within Clade 3 of the Fusarium solani species complex, carried in the mandibular mycangia of the beetle, is responsible for the typical wilt symptoms inflicted on avocado (Perse...

  5. Volatile chemicals from host and non-host trees of the redbay ambrosia beetle Xyleborus glabratus, threatening the Floridian avocado production.

    Science.gov (United States)

    The redbay ambrosia beetle Xyleborus glabratus (Coleoptera: Scolytinae) is an invasive pest introduced in spreading in Southeastern US. The beetle carries a symbiotic fungus which causes laurel wilt, a vascular disease killing of host trees of the Laureacea family as 6 weeks. We compare the chemical...

  6. Uranium industry annual 1996

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-04-01

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

  7. Uranium industry annual 1996

    International Nuclear Information System (INIS)

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

  8. Uranium industry annual, 1991

    International Nuclear Information System (INIS)

    In the Uranium Industry Annual 1991, data on uranium raw materials activities including exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities including domestic uranium purchases, commitments by utilities, procurement arrangements, uranium imports under purchase contracts and exports, deliveries to enrichment suppliers, inventories, secondary market activities, utility market requirements, and uranium for sale by domestic suppliers are presented in Chapter 2. A feature article entitled ''The Uranium Industry of the Commonwealth of Independent States'' is included in this report

  9. Lake George

    OpenAIRE

    Mafabi, P.

    2000-01-01

    Uganda ratified the Ramsar Convention in 1988, and designated Lake George a Ramsar site. Located astride the equator, the lake and associated wetlands support a wide variety of biological resources. The reasons for this are varied, ranging from the good climate to shallow stratified waters (average 2.4m) which allow for a thorough mixing of the different layers, and a high alkalinity and photosynthetic activity. The status of Lake George is varied with most of the wetlands fringing the Lak...

  10. Uranium market

    International Nuclear Information System (INIS)

    Neuxco's estimates of uranium output from operating US centers plus facilities under construction are tabulated through 1990. Buyer inventories will continue to grow through the end of 1982 and will fall off thereafter. The relative inventory level will remain at two years or above through 1984, and will consistently drop thereafter. This is an indication of the market available for imports and for new US production. 1 table

  11. Depleted uranium

    International Nuclear Information System (INIS)

    Full text: The Director General of the International Atomic Energy Agency (IAEA), Mohamed ElBaradei, issued today the following statement: The IAEA has been involved in United Nations efforts relating to the impact of the use of depleted uranium (DU) ammunition in Kosovo. It has supported the United Nations Environment Programme (UNEP) in the assessment which it is making, at the request of the Secretary-General, of that impact. In this connection, in November 2000, Agency experts participated in a UNEP-led fact-finding mission in Kosovo. DU is only slightly radioactive, being about 40% as radioactive as natural uranium. Chemically and physically, DU behaves in the same way as natural uranium. The chemical toxicity is normally the dominant factor for human health. However, it is necessary to carefully assess the impact of DU in the special circumstances in which it was used, e.g. to determine whether it was inhaled or ingested or whether fragments came into close contact with individuals. It is therefore essential, before an authoritative conclusion can be reached, that a detailed survey of the territory in which DU was used and of the people who came in contact with the depleted uranium in any form be carried out. In the meantime it would be prudent, as recommended by the leader of the November UNEP mission, to adopt precautionary measures. Depending on the results of the survey further measures may be necessary. The Agency, within its statutory responsibilities and on the basis of internationally accepted radiation safety standards, will continue to co-operate with other organizations, in particular WHO and UNEP, with a view to carrying out a comprehensive assessment. Co-operation by and additional information from NATO will be prerequisites. The experience gained from such an assessment could be useful for similar studies that may be carried out elsewhere in the Balkans or in the Gulf. (author)

  12. Uranium enrichment

    International Nuclear Information System (INIS)

    This paper reports that in 1990 the Department of Energy began a two-year project to illustrate the technical and economic feasibility of a new uranium enrichment technology-the atomic vapor laser isotope separation (AVLIS) process. GAO believes that completing the AVLIS demonstration project will provide valuable information about the technical viability and cost of building an AVLIS plant and will keep future plant construction options open. However, Congress should be aware that DOE still needs to adequately demonstrate AVLIS with full-scale equipment and develop convincing cost projects. Program activities, such as the plant-licensing process, that must be completed before a plant is built, could take many years. Further, an updated and expanded uranium enrichment analysis will be needed before any decision is made about building an AVLIS plant. GAO, which has long supported legislation that would restructure DOE's uranium enrichment program as a government corporation, encourages DOE's goal of transferring AVLIS to the corporation. This could reduce the government's financial risk and help ensure that the decision to build an AVLIS plant is based on commercial concerns. DOE, however, has no alternative plans should the government corporation not be formed. Further, by curtailing a planned public access program, which would have given private firms an opportunity to learn about the technology during the demonstration project, DOE may limit its ability to transfer AVLIS to the private sector

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

    Science.gov (United States)

    Brookins, D. G.

    1982-03-01

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

  14. Brazilian uranium exploration program

    International Nuclear Information System (INIS)

    General information on Brazilian Uranium Exploration Program, are presented. The mineralization processes of uranium depoits are described and the economic power of Brazil uranium reserves is evaluated. (M.C.K.)

  15. Radioactivity of lakes in the urbanized territories

    International Nuclear Information System (INIS)

    Full text: The lakes contain the same radioactive elements as rivers and seas. Main radioactive elements in natural waters are uranium, radium, radon and potassium. To study radioactivity of the lakes in the Absheron peninsula in 1998 and in 2000 we took specimens of water and bottom sediments from 20 typical lakes. Selection site of bottom specimens is: coast-centre of the lake, from the surface of the floor as deep as 0,5 m. There was determined amount of thorium, radium, potassium, radon-220, radon-222 in Bq/l and in the bottom sediments there was determined amount of uranium (in compliance with radium), thorium, potassium in Bq/kg. All these analyses were made in Geology Institute of Azerbaijan National Academy of Sciences. Results of the analyses to verify amount of radionuclides in the water of the investigated lakes demonstrate their absence in the water. Only one analysis revealed a small amount of radium, in the water of the lake Khodjagasa. Radioactivity of some lake waters in the Absheron peninsula is determined by potassium. Amount of potassium varies in a wide range - from 0 to 1,4 g/l. In most of the lakes amount of potassium is not more than 0,2-9,3 g/l. 0,56 g/l of potassium in the lake Pirshagi and 1,2-1,4 g/l of potassium in the lake Gyrmyzy are abnormal and demonstrate high concentration of salts in the waters of these lakes. Probably potassium is delivered to the lakes with coastal drainage. However one can suppose that the lake Gyrmyzy is a relict of marine waters and it is a basin of a lagoon origin. In the oceanic water amount of potassium varies about 0,39 g/l, i.e. it is rather high to create anomaly in the waters of the relict lakes during the evaporation. In the lakes like Beyuk Shor, Masazyr, Duzly etc. amount of potassium is somewhat lower than in the oceanic water but many times it exceeds its amount in the river water

  16. RAGWEED (AMBROSIA ARTEMISIIFOLIA L. – AGRONOMIC AND PUBLIC-HEALTH PROBLEM IN BARANYA REGION

    Directory of Open Access Journals (Sweden)

    Sanda Rašić

    2012-06-01

    Full Text Available Ragweed (Ambrosia artemisiifolia is very allergeni plant species causing a big health problem to a sensitive person. Moreover, due its high cover values ragweed is also a problem in agricultural and non-agricultural areas. By the floristic surveys (reléve method Br.-Bl, 1964 it is determined that ragweed cover a significant part of investigated territory. Floristic records (106, performed during August and beginning of September identified ragweed populations with significant number of units per area. High cover values were recorded in sunflower and stubbles, and these places are considered a focus problem. High values were also registered in ruderal habitats, and along roads and canals. Field investigations confirmed the doubts that ragweed occupies and invades more and more areas. Besides agronomic problem, ragweed is also a significant public health problem. Pollen of this weed species is exceptionally strong aeroallergen, causing big problems among sensitive persons during the summer time. Therefore, detailed aerobiological investigations (2003–2008 were performed using the volumetric method (Burkard pollen and spore trap in order to identify parameters of pollination. Ragweed pollen was mostly present in the air at the end of summer. This is the period when the allergic reaction among the sensitive persons is most registered. Pollination starts in July and finishes in October according to six year aerobiology monitoring. Length of pollination in the investigated area lasted on the average from 74 to 94 days, with the peak between 22th of August and 3rd of September. Total daily pollen counts varied from year to year from 143 pollen grains per m3 of air to 439 pollen grains per m3 of air. Meteorological parameters have a significant influence for amount of pollen grains in the air. It is proved that concentration of the pollen in the air is getting higher along with higher temperature, but it the relative humidity increases concentration

  17. Evaluation of flexible membrane liners as long-term barriers for uranium mill tailings

    International Nuclear Information System (INIS)

    The National Uranium Tailings Program has commissioned a study to evaluate flexible membrane liners (geomembranes) as long-term barriers for Canadian uranium mill tailings. This study reviews the common liner type and addresses flexible liners (polymeric membranes and asphalt) in detail. Liner fabrication, design, installation, and performance are reviewed. Conceptual designs are presented for basins to accommodate 20 years accumulation of uranium tailings from mills in Elliot Lake and southeastern Athabasca. Nine polymeric and three asphalt liner types have been considered with respect to the physical and chemical environment in the uranium producing areas of Canada. All materials indicate good chemical resistance to uranium wastes but are subject to installation problems

  18. Uranium industry annual, 1986

    International Nuclear Information System (INIS)

    Uranium industry data collected in the EIA-858 survey provide a comprehensive statistical characterization of annual activities of the industry and include some information about industry plans over the next several years. This report consists of two major sections. The first addresses uranium raw materials activities and covers the following topics: exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment. The second major section is concerned with the following uranium marketing activities: uranium purchase commitments, uranium prices, procurement arrangements, uranium imports and exports, enrichment services, inventories, secondary market activities utility market requirements and related topics

  19. The uranium deposits of Ontario

    International Nuclear Information System (INIS)

    The principal types of uranium deposits in Ontario are carbonatites and fenites, alkalic volcanic rocks, pegiatites, calc-silicate rocks, pyritic quartz-pebble conglomerates, polymictic conglomerates and some pelitic rocks, and various 'pitchblende' deposits including late Precambrian unconformities, possibly late Precambrian diabase dikes, and other unconformities: carbonates, sandstones, lignites, and semi-pelitic rocks of middle and upper Precambrian age. Only red unzoned pegmatite and the pyritic quartz-pebble conglomerate have supported production. Ontario reasonably assured and estimated resources in the economic and subeconomic categories in 1977 amounted to 553 000 tonnes U, and 1977 production was 4000 tonnes U. Measured, indicated, and inferred resources in the Elliot Lake - Agnew Lake area are at least 400 000 tonnes U. The latter deposits are also a significant thorium resource. Geological features reflecting major changes in physics and chemistry are prime controls on distribution of uranium deposits. Geological province and subprovince boundaries, major faults, higher metamorphic grades, domain boundaries related to quartz monzonite batholiths, alkalic complexes, and the distribution of carbonate rocks are examples of such geological features

  20. Uranium Industry Annual, 1992

    International Nuclear Information System (INIS)

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

  1. Uranium Industry Annual, 1992

    Energy Technology Data Exchange (ETDEWEB)

    1993-10-28

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

  2. Environmental impact of uranium mining and milling

    International Nuclear Information System (INIS)

    The Atomic Energy Control Board is now involved from the early planning stages in the development of uranium mine/mill facilities. As a result, new facilities (including tailings management areas) are designed and developed to meet a high standard. The impact of the mines and tailings areas in the Elliot Lake area on ground and surface waters and air quality is discussed in detail

  3. Biological aspects and life table of Uroleucon ambrosiae (Thomas, 1878 as a function of temperature Aspectos biológicos e tabela de vida de Uroleucon ambrosiae (Thomas em função da temperatura

    Directory of Open Access Journals (Sweden)

    Alexander Machado Auad

    2003-12-01

    Full Text Available The aphid Uroleucon ambrosiae (Thomas is considered a pest of hidroponically-grown lettuce, but basic and applied information on its control are scarce in Brazil. The aim of this study was to determine the effect of different temperatures on biological aspects and life history of U. ambrosiae (Thomas developing on hydroponic lettuce (Lactuca sativa L. crop. Newly emerged nymphs were placed on 4-cm discs of hydroponic lettuce, var. Verônica, which were maintained on 5-cm Petri dishes, at temperatures of 15, 20 and 25ºC and 14 h photophase, and inside a greenhouse, within micro-cages at room temperature. The duration of development in all nymphal stages varied inversely to temperature. Nymphs maintained at 20ºC and 25ºC, had similar development period. However, at fluctuating greenhouse temperatures (daily mean = 21ºC, different results were obtained, which was also true for the pre-reproductive, reproductive and post-reproductive periods. Daily and total fertilities at 20ºC were better in comparison to the other treatments. The highest mortality rate of aphids occurred under greenhouse conditions. The production of 1.28 nymphs per female per day, the time needed for the population to double in size (TD=2.77days, and the intrinsic rate of population increase (r m=0.25, were similar for in insects maintained at 20 and 25ºC. On the other hand, time interval between generations (T and the net reproductive rate (Ro were higher at 20ºC. In the greenhouse, even though T was similar to laboratory conditions at 20 and 25ºC, the R0, r m and l parameters were lower and TD was higher. Based on biological aspects, fertility and life expectancy tables, constant temperature of 20ºC is the most suitable for U. ambrosiae.O afídeo Uroleucon ambrosiae (Thomas é considerado praga em alface de cultivo hidropônico, mas conhecimentos básicos e aplicados que auxiliam no seu controle, são escassos no Brasil. O objetivo do trabalho foi determinar o efeito

  4. Uranium recovery from slags of metallic uranium

    International Nuclear Information System (INIS)

    The Center of the Nuclear Fuel of the Institute of Nuclear Energy Research - IPEN finished the program of attainment of fuel development for research reactors the base of Uranium Scilicet (U3 Si2) from Hexafluoride of Uranium (UF6) with enrichment 20% in weight of 235U. In the process of attainment of the league of U 3 Si 2 we have as Uranium intermediate product the metallic one whose attainment generates a slag contend Uranium. The present work shows the results gotten in the process of recovery of Uranium in slags of calcined slags of Uranium metallic. Uranium the metallic one is unstable, pyrophoricity and extremely reactive, whereas the U3O8 is a steady oxide of low chemical reactivity, what it justifies the process of calcination of slags of Uranium metallic. The calcination of the Uranium slag of the metallic one in oxygen presence reduces Uranium metallic the U3O8. Experiments had been developed varying it of acid for Uranium control and excess, nitric molar concentration gram with regard to the stoichiometric leaching reaction of temperature of the leaching process. The 96,0% income proves the viability of the recovery process of slags of Uranium metallic, adopting it previous calcination of these slags in nitric way with low acid concentration and low temperature of leaching. (author)

  5. The Effect of Field Dodder (Cuscuta campestris Yunck. on Morphological and Fluorescence Parameters of Giant Ragweed (Ambrosia trifida L.

    Directory of Open Access Journals (Sweden)

    Sava Vrbničanin

    2013-01-01

    Full Text Available The effect of the parasitic flowering plant known as field dodder (Cuscuta campestrisYunck. on morphological and fluorescence parameters of infested giant ragweed(Ambrosia trifida L. plants was examined under controlled conditions. The parameters ofchlorophyll fluorescence (Fo, Fv/Fm, ΦPSII, Fv, Fm, ETR and IF were measured on infested (Iand non-infested (N A. trifida plants over a period of seven days, beginning with the day ofinfestation. Morphological parameters (plant height, dry and fresh weight were measuredon the last day of fluorescence measurements. C. campestris was found to affect the height,fresh and dry weight of the infested A. trifida plants, causing significant reduction in plantheight and dry weight. Field dodder also affected several parameters of chlorophyll fluorescence(Fo, Fv/Fm, ΦPSII and Fv in infested A. trifida plants.

  6. [Spread of Ambrosia elatior in rural areas (investigation performed during the years 1985 and 1986 in southern Drome)].

    Science.gov (United States)

    Couturier, P

    1987-06-01

    The settings of Ambrosia development are not only construction zones, waste grounds, road works; a country extension has been observed; more and more varied lands under cultivation (cereals, sunflowers, peach-trees...) are overgrown and the advance, toward South Drome and Ardèche since few years, clearly indicates that all the Rhone Valley is under threat. Several forms of spreading are possible, sometimes very unexpected, so, for instance, the irrigation by spraying. The struggle must associate the mowing when it is easy (town zones, verges...), selective weed-killer use and a good farming rotation (country zones). A better information of town councils about those problems is also absolutely necessary for us. PMID:3454180

  7. Erfahrungen mit der Bekämpfung von Ambrosia in der Schweiz – ein Rückblick

    Directory of Open Access Journals (Sweden)

    Bohren, Christian

    2014-07-01

    Full Text Available The dicotyledonous summer annual common ragweed (Ambrosia artemisiifolia L. is on the one hand a noxious arable weed and on the other hand an invasive neophyte with a great potential to spread. Various possibilities are known for control of common ragweed in agricultural fields with mechanical and chemical methods. Limits are set in sunflowers because sunflower and ragweed are botanically related. Because no weed control action results in 100% efficacy, common ragweed can propagate quickly in untreated corners of the field or in other disturbed soils. The legal obligation of reporting and control – introduced in Switzerland a couple of years ago – allowed the development of specific distribution maps and enhanced the quality of control measures. Facts and figures from the Canton of Geneva prove that the ragweed invasion has been stopped, but the species is not eradicated. The results of Geneva represent the results of good ragweed control in the whole country. Beside agriculture, traffic infrastructure, building sites, gravel pits and urban park and garden areas are sensible to ragweed invasion. This is why the formation of “Ambrosia Groups” helps to exchange experiences and to understand factors provoking the invasion. The responsibility of individuals helps to improve control efficiency even if financial funds are small. A sustainable control success depends on the efficiency to hamper seed production. The reduction of pollen quantity in the air in a long term is part of the earnings for the control effort. Actually, the publicity of common ragweed is fed by specialist information and its distribution in the media. It would be an interesting task to develop in our fast moving era an awareness level comparable to that of the stinging nettle.

  8. International uranium production. An eastern Canadian perspective

    International Nuclear Information System (INIS)

    The Eastern Canadian perspective on uranium production is based on 30 years of continuous mining at Elliot Lake and on the experience of selling uranium over the same time period, mainly to export markets. In Ontario the orebodies are basically contiguous, being part of the same large formation. All the mining is underground. Ore grades are low, but economic extraction is improved by continuity and uniformity of grades, stable ground conditions, and the ability to mine and mill on a large scale. Mining is being carried out by two companies, Denison and Rio Algom. It is unlikely that mine capacity will be increased. Government policies have significant effects on the Eastern Canadian uranium industry in particular, as to U.S. import policies. (L.L.)

  9. Environmental impact of uranium mining and milling

    International Nuclear Information System (INIS)

    The author introduces the subject with an overview of the regulatory requirments and philosophy applied to uranium mines and mills. The special attention given to tailings management is highlighted, and a discussion of the basic environmental concerns is concluded with an itemizing of the main tasks facing the AECB. The extent of the environmental impact of uranium mining, milling and waste management is illustrated with specific details pertaining to mines in the Elliot Lake area. The author concludes that the impact on the ground and surface water system is not alarming, and the impact on air quality is not significant beyond a few hundred metres from the mining facilities. The publicly perceived impact is discussed, followed by a rationale for the continued licensing of new uranium mining operations complete with tailings management facilities

  10. Uranium enrichment

    International Nuclear Information System (INIS)

    This chapter discusses the development of uranium enrichment processes. In the introduction there is a brief history of uranium enrichment, followed by a summary of the criteria used for the assessment of an isotope separation process, e.g. the separation factor, separative power, and the power consumption of a separating element. This is followed by a discussion of the two main processes used, i.e. gaseous diffusion and centrifugation. The reason for the change from diffusion to centrifugation in the UK, mainly on power costs, is discussed. The development potential of centrifuges is also assessed. Other processes which have been developed up to pilot stage are described, e.g. the Becker jet nozzle and the South African process. This is followed by a description of some plasma-based methods. The next topic is concerned with chemical exchange methods and an attempt is made to assess their potential in the enrichment scene from published information. This chapter concludes with a discussion of the advanced laser isotope-separation methods. The two approaches, i.e. the atomic and the molecular routes are discussed again using published information. This information is insufficient to give a complete assessment of the methods, especially the molecular route, but is enough to give indications of their potential

  11. Uranium processing and properties

    CERN Document Server

    2013-01-01

    Covers a broad spectrum of topics and applications that deal with uranium processing and the properties of uranium Offers extensive coverage of both new and established practices for dealing with uranium supplies in nuclear engineering Promotes the documentation of the state-of-the-art processing techniques utilized for uranium and other specialty metals

  12. Irradiated uranium reprocessing

    International Nuclear Information System (INIS)

    Task concerned with reprocessing of irradiated uranium covered the following activities: implementing the method and constructing the cell for uranium dissolving; implementing the procedure for extraction of uranium, plutonium and fission products from radioactive uranium solutions; studying the possibilities for using inorganic ion exchangers and adsorbers for separation of U, Pu and fission products

  13. Issues in uranium availability

    International Nuclear Information System (INIS)

    The purpose of this publication is to show the process by which information about uranium reserves and resources is developed, evaluated and used. The following three papers in this volume have been abstracted and indexed for the Energy Data Base: (1) uranium reserve and resource assessment; (2) exploration for uranium in the United States; (3) nuclear power, the uranium industry, and resource development

  14. Uranium industry annual 1985

    International Nuclear Information System (INIS)

    This report consists of two major sections. The first addresses uranium raw materials activities and covers the following topics: exploration activities and expenditures, resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment. The second major section is concerned with the following uranium marketing activities: uranium purchase commitments, uranium prices, procurement arrangements, uranium imports and exports, enrichment services, inventories, secondary market activities, utility market requirements, and related topics. A glossary and appendices are included to assist the reader in interpreting the substantial array of statistical data in this report and to provide background information about the survey

  15. Playa Lakes

    Data.gov (United States)

    Kansas Data Access and Support Center — This digital dataset provides information about the spatial distribution of soil units associated with playa lakes. Specific soil types have been designated by the...

  16. Reports on investigations of uranium anomalies. National Uranium Resource Evaluation

    International Nuclear Information System (INIS)

    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 10 x 20 quadrangles for the NURE program also yielded anomalies, which could not be adequately checked 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

  17. Uranium infiltration from a river to shallow groundwater

    International Nuclear Information System (INIS)

    The infiltration of uranium from the polluted River Glatt (Switzerland) into a hydraulically connected saturated aquifer was investigated during a period of almost five years. The uranium concentrations and the 234U/238U activity ratios (ARs) were analysed monthly in the water of the river and of four groundwater sampling wells. The speciation of uranium and its relation to other aqueous and solid components were investigated experimentally and in model calculations. The uranium concentration and the ARs in the river varied seasonally with a maximum and a minimum, respectively, in summer. Processes, such as photo-reductive dissolution of iron-oxyhydroxides or the enhanced decomposition of organic matter and calcite in the upstream, eutrophic Lake Greifen may have caused these variations. Laboratory experiments confirmed a possible release of uranium by photochemical reactions. The concentration maximum of uranium was also detected in the shallow groundwater, but with a delay of about six months to the maximum in the river. Under the assumption that the maxima in the river and the groundwater were related, an in situ distribution coefficient (KD) for uranium of ∼7 mL g-1 can be calculated for this Quaternary gravel aquifer. Uranium was present predominantly as UO2-carbonate complexes, whereas the formation of phosphate and organic complexes (e.g., UO2-humates/EDTA/NTA) was negligible. Particles and colloids played a minor role for the transport of uranium in this aquifer. In the course of this study, we observed an ongoing general decrease of the uranium concentrations and a disappearance of its summerly maxima in the River Glatt. We relate this unexpected effect to a better control of the phosphate concentration in surface waters, which diminished the growth of aquatic biota. This, in turn, led to changes in the redox conditions of lake and river sediments, and herewith to a reduced release of heavy metals

  18. Lake Ponkapog

    Institute of Scientific and Technical Information of China (English)

    蓝洋

    2002-01-01

    @@ Thirty years ago,Lake Ponkapog in Hartwell,New Jersey,was full of life.Many birds and animals rived beside the water,which was frill of fish.Now there are few birds.animals and fish.The lake water is polluted(污染的).It is in a colour of dirty brown,and it is filled with strange plants.

  19. Depleted Uranium Management

    International Nuclear Information System (INIS)

    The paper considers radiological and toxic impact of the depleted uranium on the human health. Radiological influence of depleted uranium is less for 60 % than natural uranium due to the decreasing of short-lived isotopes uranium-234 and uranium-235 after enrichment. The formation of radioactive aerosols and their impact on the human are mentioned. Use of the depleted uranium weapons has also a chemical effect on intake due to possible carcinogenic influence on kidney. Uranium-236 in the substance of the depleted uranium is determined. The fact of beta-radiation formation in the uranium-238 decay is regarded. This effect practically is the same for both depleted and natural uranium. Importance of toxicity of depleted uranium, as the heavier chemical substance, has a considerable contribution to the population health. The paper analyzes risks regarding the use of the depleted uranium weapons. There is international opposition against using weapons with depleted uranium. Resolution on effects of the use of armaments and ammunitions containing depleted uranium was five times supported by the United Nations (USA, United Kingdom, France and Israel did not support). The decision for banning of depleted uranium weapons was supported by the European Parliament

  20. Key Lake, a model of Canadian development

    International Nuclear Information System (INIS)

    Canada ranks among the world's top four countries in terms of measured, indicated, and inferred uranium resources. Since 1984, Canada has been the world's largest uranium producer providing some 30% of the world's total. An important reason for this strong position is related to the discovery of high-grade near-surface uranium deposits in northern Saskatchewan in 1968 and subsequently. The history of the discovery of one such deposit near Key Lake made by the German-controlled Uranerz Exploration and Mining Limited is recounted briefly. The Key Lake mine became operational in 1983 and currently is the largest uranium-producing facility in the world. At present, less than 20% of the country's annual uranium output of approximately 11,000 tonnes U is required to provide fuel for the domestic nuclear power program. The excess, more than 9000 tonnes U annually, is planned to be exported abroad, primarily to customers in Western Europe, Eastern Asia and the United States. Given its strong resource base, large-scale exports from Canada should continue well into the next century. (orig.)

  1. URANIUM DECONTAMINATION

    Science.gov (United States)

    Buckingham, J.S.; Carroll, J.L.

    1959-12-22

    A process is described for reducing the extractability of ruthenium, zirconium, and niobium values into hexone contained in an aqueous nitric acid uranium-containing solution. The solution is made acid-deficient, heated to between 55 and 70 deg C, and at that temperature a water-soluble inorganic thiosulfate is added. By this, a precipitate is formed which carries the bulk of the ruthenium, and the remainder of the ruthenium as well as the zirconium and niobium are converted to a hexone-nonextractable form. The rutheniumcontaining precipitate can either be removed from the solu tion or it can be dissolved as a hexone-non-extractable compound by the addition of sodium dichromate prior to hexone extraction.

  2. Natural uranium

    International Nuclear Information System (INIS)

    This sheet belongs to a collection which relates to the use of radionuclides essentially in unsealed sources. Its goal is to gather on a single document the most relevant information as well as the best prevention practices to be implemented. These sheets are made for the persons in charge of radiation protection: users, radioprotection-skill persons, labor physicians. Each sheet treats of: 1 - the radio-physical and biological properties; 2 - the main uses; 3 - the dosimetric parameters; 4 - the measurement; 5 - the protection means; 6 - the areas delimitation and monitoring; 7 - the personnel classification, training and monitoring; 8 - the effluents and wastes; 9 - the authorization and declaration administrative procedures; 10 - the transport; and 11 - the right conduct to adopt in case of incident or accident. This sheet deals specifically with natural uranium

  3. Liquefaction of uranium tailings

    International Nuclear Information System (INIS)

    Numerical methods for assessing the liquefaction potential of soils are reviewed with a view to their application to uranium tailings. The method can be divided into two categories: total stress analysis, where changes in pore pressure are not considered in the soil model, and effective stress analysis, where changes in pore pressure are included in the soil model. Effective stress analysis is more realistic, but few computer programs exist for such analysis in two or three dimensions. A simple linearized, two-dimensional, finite element effective stress analysis which incorporates volumetric compaction due to shear motion is described and implemented. The new program is applied to the assessment of liquefaction potential of tailings in the Quirke Mine tailings area near Elliot Lake, Ontario. The results are compared with those of a total stress analysis. Both analyses indicate liquefaction would occur if a magnitude 6.0 earthquake were to occur near the area. However, the extent of liquefaction predicted by the effective stress analysis is much less than that predicted by the total stress analysis. The results of both methods are sensitive to assumed material properties and to the method used to determine the cyclic shear strength of the tailings. Further analysis, incorporating more in situ and/or laboratory data, is recommended before conclusions can be made concerning the dynamic stability of these tailings

  4. Tempo de busca e de manuseio de larvas de Chrysoperla externa (Hagen, 1861 (Neuroptera, Chrysopidae alimentadas com Uroleucon ambrosiae (Thomas, 1878 (Hemiptera, Aphididae

    Directory of Open Access Journals (Sweden)

    Alexander M. Auad

    2002-01-01

    Full Text Available Searching and handling time of Chrysoperla externa (Hagen, 1861 (Neuroptera, Chrysopidae larvae fed on Uroleucon ambrosiae (Thomas, 1878 (Hemiptera, Aphididae. The objective of this research was to determine the searching and handling times of three larval instars of C. externa fed on U. ambrosiae at densities of 30, 40 and 50 per vial, with the feeding of the larvae at the preceding instars being U. ambrosiae nymphs or Sitotroga cerealella (Olivier, 1819 eggs. The larvae were maintained at 25 ± 2 ºC, 70 ± 10% RH and a 14-h photophase. A completely randomized design in a 6 x 3 factorial scheme with 12 replicates was adopted. The shortest searching time was found for the 2nd and 3rd instar larvae of C. externa, and this parameter was variable depending on the feeding given to the larvae previously. The handling time was similar for the 1st, 2nd and 3rd instar larvae. The longest searching time was found at an aphid density of 30, as compared to densities of 40 and 50 prey, with which there were no significant differences. Prey density did not have any influence on handling time.

  5. Geology and discovery of proterozoic uranium deposits, Central District of Keewatin, Northwest Territories, Canada

    International Nuclear Information System (INIS)

    Proterozoic supracrustal successions, Central District of Keewatin, are similar to the Proterozoic basins of northern Saskatchewan which contain economic uranium deposits. In this paper, examples of three of the more important uranium deposit types are described. Early Aphebian shallow marine pelitic to psammitic metasediments of the upper Amer group host subeconomic uranium concentrations. Late Aphebian structurally controlled depressions, Baker Lake Basin, Yathkyed Lake and Angikuni Lake subbasins, are filled with continental sediments and volcanics of the Dubawnt Group. Structurally controlled uranium mineralisation is most common adjacent to the margins of these basins. Conglomerate and sandstone of the Helikian Thelon Basin lie unconformably on a highly weathered basement complex. The Lone Gull deposit is hosted in retrograded and altered psammitic to pelitic metasediments and undeformed granite near the erosional edge of the basin. Mineralisation is structurally controlled and associated with zones of intense K- and Mg-metasomatism. These features parallel those of the unconformity-related deposits of N. Saskatchewan

  6. Morphology Characterization of Uranium Particles From Laser Ablated Uranium Materials

    Institute of Scientific and Technical Information of China (English)

    2011-01-01

    In the study, metallic uranium and uranium dioxide material were ablated by laser beam in order to simulate the process of forming the uranium particles in pyrochemical process. The morphology characteristic of uranium particles and the surface of

  7. Lake Victoria: the Changing Lake.

    OpenAIRE

    Mwirigi, P.; Rutagemwa, D.; Gikuma-Njuru, P.; Njuguna, H.; Matovu, A.; Waya, R.; Mwebaza-Ndawula, L.; Ssenfuma-Nsubuga, M.; Kinobe, J.; Abuodha, J.; Hecky, R

    2005-01-01

    Water quality monitoring activities were carried out on physical-chemical parameters, water chemistry and biotic indices at selected littoral and pelagic stations along north-south and east-west transects over an annual cycle between 2000 and 2005. The activities were aimed at collecting baseline information and data for use to define the current lake conditions and make a water quality assessment of the lake in relation to nutrient/ pollutant loadings as a basis for future monitoring surveys...

  8. 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)

  9. Uranium management activities

    International Nuclear Information System (INIS)

    One of the missions of the Department of Energy's (DOE) Oak Ridge Office (ORO) has been the management of the Department's uranium materials. This mission has been accomplished through successful integration of ORO's uranium activities with the rest of the DOE complex. Beginning in the 1980's, several of the facilities in that complex have been shut down and are in the decommissioning process. With the end of the Cold War, the shutdown of many other facilities is planned. As a result, inventories of uranium need to be removed from the Department facilities. These inventories include highly enriched uranium (HEU), low enriched uranium (LEU), normal uranium (NU), and depleted uranium (DU). The uranium materials exist in different chemical forms, including metals, oxides, solutions, and gases. Much of the uranium in these inventories is not needed to support national priorities and programs. (author)

  10. Uranium Provinces in China

    Institute of Scientific and Technical Information of China (English)

    2000-01-01

    Three uranium provinces are recognized in China, the Southeast China uranium province, the Northeast China-lnner Mongolia uranium province and the Northwest China (Xinjiang) uranium province. The latter two promise good potential for uranium resources and are major exploration target areas in recent years. There are two major types of uranium deposits: the Phanerozoic hydrothermal type (vein type) and the Meso-Cenozoic sandstone type in different proportions in the three uranium provinces. The most important reason or prerequisite for the formation of these uranium provinces is that Precambrian uranium-enriched old basement or its broken parts (median massifs) exists or once existed in these regions, and underwent strong tectonomagmatic activation during Phanerozoic time. Uranium was mobilized from the old basement and migrated upwards to the upper structural level together with the acidic magma originating from anatexis and the primary fluids, which were then mixed with meteoric water and resulted in the formation of Phanerozoic hydrothermal uranium deposits under extensional tectonic environments. Erosion of uraniferous rocks and pre-existing uranium deposits during the Meso-Cenozoic brought about the removal of uranium into young sedimentary basins. When those basins were uplifted and slightly deformed by later tectonic activity, roll-type uranium deposits were formed as a result of redox in permeable sandstone strata.

  11. Uranium industry annual 1998

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-04-22

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry`s activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ``Uranium Industry Annual Survey.`` Data provides a comprehensive statistical characterization of the industry`s activities for the survey year and also include some information about industry`s plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ``Uranium Industry Annual Survey`` is provided in Appendix C. The Form EIA-858 ``Uranium Industry Annual Survey`` is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs.

  12. Uranium industry annual 1998

    International Nuclear Information System (INIS)

    The Uranium Industry Annual 1998 (UIA 1998) provides current statistical data on the US uranium industry's activities relating to uranium raw materials and uranium marketing. It contains data for the period 1989 through 2008 as collected on the Form EIA-858, ''Uranium Industry Annual Survey.'' Data provides a comprehensive statistical characterization of the industry's activities for the survey year and also include some information about industry's plans and commitments for the near-term future. Data on uranium raw materials activities for 1989 through 1998, including exploration activities and expenditures, EIA-estimated reserves, mine production of uranium, production of uranium concentrate, and industry employment, are presented in Chapter 1. Data on uranium marketing activities for 1994 through 2008, including purchases of uranium and enrichment services, enrichment feed deliveries, uranium fuel assemblies, filled and unfilled market requirements, and uranium inventories, are shown in Chapter 2. The methodology used in the 1998 survey, including data edit and analysis, is described in Appendix A. The methodologies for estimation of resources and reserves are described in Appendix B. A list of respondents to the ''Uranium Industry Annual Survey'' is provided in Appendix C. The Form EIA-858 ''Uranium Industry Annual Survey'' is shown in Appendix D. For the readers convenience, metric versions of selected tables from Chapters 1 and 2 are presented in Appendix E along with the standard conversion factors used. A glossary of technical terms is at the end of the report. 24 figs., 56 tabs

  13. Uranium industry annual 1994

    International Nuclear Information System (INIS)

    The Uranium Industry Annual 1994 (UIA 1994) provides current statistical data on the US uranium industry's activities relating to uranium raw materials and uranium marketing during that survey year. The UIA 1994 is prepared for use by the Congress, Federal and State agencies, the uranium and nuclear electric utility industries, and the public. It contains data for the 10-year period 1985 through 1994 as collected on the Form EIA-858, ''Uranium Industry Annual Survey.'' Data collected on the ''Uranium Industry Annual Survey'' (UIAS) provide a comprehensive statistical characterization of the industry's activities for the survey year and also include some information about industry's plans and commitments for the near-term future. Where aggregate data are presented in the UIA 1994, care has been taken to protect the confidentiality of company-specific information while still conveying accurate and complete statistical data. A feature article, ''Comparison of Uranium Mill Tailings Reclamation in the United States and Canada,'' is included in the UIA 1994. Data on uranium raw materials activities including exploration activities and expenditures, EIA-estimated resources and reserves, mine production of uranium, production of uranium concentrate, and industry employment are presented in Chapter 1. Data on uranium marketing activities, including purchases of uranium and enrichment services, and uranium inventories, enrichment feed deliveries (actual and projected), and unfilled market requirements are shown in Chapter 2

  14. Modeling and management of pit lake water chemistry 1: Theory

    International Nuclear Information System (INIS)

    Highlights: • Review of pit lake literature in the context of pit lake predictions. • Review of approaches used to predict pit wall-rock runoff and leachate. • Review of approaches used to generate a pit lake water balance. • Review of approaches used to generate a hydrodynamic prediction. • Review of approaches used to generate a geochemical prediction of a future pit lake. - Abstract: Pit lakes are permanent hydrologic/landscape features that can result from open pit mining for metals, coal, uranium, diamonds, oil sands, and aggregates. Risks associated with pit lakes include local and regional impacts to water quality and related impacts to aquatic and terrestrial ecosystems. Stakeholders rely on predictive models of water chemistry to prepare for and manage these risks. This paper is the first of a two part series on the modeling and management of pit lakes. Herein, we review approaches that have been used to quantify wall-rock runoff geochemistry, wall-rock leachate geochemistry, pit lake water balance, pit lake limnology (i.e. extent of vertical mixing), and pit lake water quality, and conclude with guidance on the application of models within the mine life cycle. The purpose of this paper is to better prepare stakeholders, including future modelers, mine managers, consultants, permitting agencies, land management agencies, regulators, research scientists, academics, and other interested parties, for the challenges of predicting and managing future pit lakes in un-mined areas

  15. Uranium: one utility's outlook

    International Nuclear Information System (INIS)

    The perspective of the Arizona Public Service Company (APS) on the uncertainty of uranium as a fuel supply is discussed. After summarizing the history of nuclear power and the uranium industries, a projection is made for the future uranium market. An uncrtain uranium market is attributed to various determining factors that include international politics, production costs, non-commercial government regulation, production-company stability, and questionable levels of uranium sales. APS offers its solutions regarding type of contract, choice of uranium producers, pricing mechanisms, and aids to the industry as a whole. 5 references, 10 figures, 1 table

  16. Uranium: a basic evaluation

    International Nuclear Information System (INIS)

    All energy sources and technologies, including uranium and the nuclear industry, are needed to provide power. Public misunderstanding of the nature of uranium and how it works as a fuel may jeopardize nuclear energy as a major option. Basic chemical facts about uranium ore and uranium fuel technology are presented. Some of the major policy decisions that must be made include the enrichment, stockpiling, and pricing of uranium. Investigations and lawsuits pertaining to uranium markets are reviewed, and the point is made that oil companies will probably have to divest their non-oil energy activities. Recommendations for nuclear policies that have been made by the General Accounting Office are discussed briefly

  17. Enriching recycled uranium

    International Nuclear Information System (INIS)

    The paper reviews the progress of the use of recycled uranium during the period 1985-8. This article was originally presented as a paper at the 1988 Uranium Institute symposium (which was held in London). A description is given of the differences between natural and recycled uranium, and the presence of U236 in recycled uranium. The concept of equivalent reactivity is described, as well as the cost benefit of using recycled uranium. A summary of Urenco tests and trials with reprocessed uranium is given. Enrichment, UF6 conversion and fuel fabrication are also discussed. (U.K.)

  18. Uranium health physics

    International Nuclear Information System (INIS)

    This report contains the papers delivered at the Summer School on Uranium Health Physics held in Pretoria on the 14 and 15 April 1980. The following topics were discussed: uranium producton in South Africa; radiation physics; internal dosimetry and radiotoxicity of long-lived uranium isotopes; uranium monitoring; operational experience on uranium monitoring; dosimetry and radiotoxicity of inhaled radon daughters; occupational limits for inhalation of radon-222, radon-220 and their short-lived daughters; radon monitoring techniques; radon daughter dosimeters; operational experience on radon monitoring; and uranium mill tailings management

  19. Uranium: myths and realities the depleted uranium

    International Nuclear Information System (INIS)

    Uranium is an element whose name causes worry. The uranium properties are very unknown for people. However the element plays an important roll in the Earth as responsible of numerous natural phenomena, which are vital for life evolution. An example of the low knowledge about uranium has been the Balkan syndrome. A relation between cancers and the use of depleted uranium in ammunition in the Balkan War has been pretended to be established. From the beginning, this hypothesis could have been discarded as it has been confirmed and stated in recent reports of UNEP Commissions who have studied this matter. (Author)

  20. Uranium production

    International Nuclear Information System (INIS)

    The domestic uranium industry is in a state of stagflation. Costs continue to rise while the market for the product remains stagnant. During the last 12 months, curtailments and closures of mines and mills have eliminated over 5000 jobs in the industry, plus many more in those industries that furnish supplies and services. By January 1982, operations at four mills and the mines that furnish them ore will have been terminated. Other closures may follow, depending on cost trends, duration of current contracts, the degree to which mills have been amortized, the feasibility of placing mines on standby, the grade of the ore, and many other factors. Open-pit mines can be placed on standby without much difficulty, other than the possible cost of restoration before all the ore has been removed. There are a few small, dry, underground mines that could be mothballed; however, the major underground producers are wet sandstone mines that in most cases could not be reopened after a prolonged shutdown; mills can be mothballed for several years. Figure 8 shows the location of all the production centers in operation, as well as those that have operated or are on standby. Table 1 lists the same production centers plus those that have been deferred, showing nominal capacity of conventional mills in tons of ore per calendar day, and the industry production rate for those mills as of October 1, 1981

  1. Statistical study of geochemistry and mineralogy of uraniferous lake beds in Oligocene Brule Formation in northwestern Nebraska

    International Nuclear Information System (INIS)

    A small area of uranium enrichment is present in an evaporitic lake deposit of the Oligocene Brule Formation about 16 mi northeast of Chadron in northwestern Nebraska. Detrital sediments in the lake beds consist of quartz, feldspar, montmorillonite, illite, and volcanic shards. Minerals precipitated from lake waters are calcite, dolomite, and gypsum; they represent increasing concentration, in that order, of dissolved solids in lake waters. Diagenetic minerals are mainly opal and chalcedony and some calcite, dolomite, and gypsum. Elements mainly associated with detrital sediments include Al, Fe, K, Ti, Na, Li, and Cu. Elements mainly associated with chemical precipitates and diagenetic minerals are Ca, Sr, Si, Mn, and U. Silica and uranium were probably derived from volcanic ash abundant in the sediments. Uranium was deposited in the most evaporitic lake phases. No zeolites or authigenic clay minerals were found in any lake facies. Altered ash beds within the Brule contain abundant authigenic montmorillonitic clay that was apparently reworked before or during lacustrine deposition. Strontium is associated with gypsum and was apparently deposited in that mineral as a substitute for Ca. Uranium is associated with strontium, but probably only because they were both deposited during the most evaporitic periods of lake deposition. Uranium was not linked to any other element in a factor analysis (for four factors), which accounted for only about 27% of the variation in uranium

  2. Characterization of a Plasmopara species on Ambrosia artemisiifolia, and notes on P. halstedii, based on morphology and multiple gene phylogenies.

    Science.gov (United States)

    Choi, Young-Joon; Kiss, Levente; Vajna, László; Shin, Hyeon-Dong

    2009-10-01

    Common ragweed (Ambrosia artemisiifolia) is an invasive and highly allergenic plant species, on which two species, Plasmopara halstedii and Plasmopara angustiterminalis, have been recognized to cause downy mildew disease. In this study, morphological and molecular patterns of seven Plasmopara specimens collected from A. artemisiifolia in Canada, Hungary, and USA were compared with those of P. halstedii and P. angustiterminalis from Helianthus and Xanthium, respectively. Analyses of partial sequences of three genes, namely those for the large subunit (28S) of rDNA, cytochrome c oxidase subunit II (COX2), and NADH dehydrogenase subunit I (ND1) of mtDNA, were carried out to examine the phylogenetic relationships among these specimens using both Bayesian and maximum parsimony methods. All the phylogenetic analyses revealed that the downy mildew pathogens infecting A. artemisiifolia in Hungary and North America clearly represent a lineage distinct from other Plasmopara taxa investigated. The shape of sporangia and the width of trunks and branches also allowed the separation of the specimens parasitic to A. artemisiifolia from P. halstedii on Helianthus annuus and P. angustiterminalis on Xanthium strumarium. Surprisingly, the Hungarian and the Canadian specimens were more closely related to each other than to those from the USA based on COX2 and ND1 mtDNA data, although the D1/D2/D3 sequences of 28S rDNA were identical in all these Plasmopara specimens. The regional distribution of the mtDNA haplotypes seen in this study suggests a transatlantic migration has occurred and would be interesting to follow up with a more detailed sampling. To investigate the diversity within P. halstedii sensu lato, infecting different host plant species, specimens from six asteraceous genera, Ambrosia, Flaveria, Helianthus, Siegesbeckia, Solidago, and Xanthium, were also included in molecular analyses. These represented six distinct lineages according to the host plant genera. These

  3. Hydrogeology of an ancient arid closed basin: Implications for tabular sandstone-hosted uranium deposits

    International Nuclear Information System (INIS)

    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

  4. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    The following topics are described briefly: the way phosphate fertilizers are made; how uranium is recovered in the phosphate industry; and how to detect covert uranium recovery operations in a phsophate plant

  5. Uranium exploration in Australia

    International Nuclear Information System (INIS)

    Australia has more low-cost uranium in deposits than any other country, but finding it is not easy. While the price for uranium has been low, little was found but now exploration is starting to increase.

  6. DEPLETED URANIUM TECHNICAL WORK

    Science.gov (United States)

    The Depleted Uranium Technical Work is designed to convey available information and knowledge about depleted uranium to EPA Remedial Project Managers, On-Scene Coordinators, contractors, and other Agency managers involved with the remediation of sites contaminated with this mater...

  7. Uranium mining in Australia

    International Nuclear Information System (INIS)

    The mining of uranium in Australia is criticised in relation to it's environmental impact, economics and effects on mine workers and Aborigines. A brief report is given on each of the operating and proposed uranium mines in Australia

  8. International trade in uranium

    International Nuclear Information System (INIS)

    The subject is discussed under the following headings: need for security of uranium supply; pressures on international trade; mechanism of international trade; non-proliferation and uranium trade; means of increasing security of supply. (U.K.)

  9. Brazilian uranium deposits

    International Nuclear Information System (INIS)

    Estimatives of uranium reserves carried out in Figueira, Itataia, Lagoa Real and Espinharas, in Brazil are presented. The samples testing allowed to know geological structures, and the characteristics of uranium mineralization. (M.C.F.)

  10. Uranium in Niger

    International Nuclear Information System (INIS)

    This document presents government policy in the enhancement of uranium resources, existing mining companies and their productions, exploitation projects and economical outcome related to the uranium mining and auxiliary activities

  11. Invasive alien species giant ragweed (Ambrosia trifida L.) and its risk assessment%外来入侵物种三裂叶豚草(Ambrosia trifida L.)及其风险分析

    Institute of Scientific and Technical Information of China (English)

    魏守辉; 曲哲; 张朝贤; 李咏军; 李香菊

    2006-01-01

    外来入侵物种严重威胁着农业生产、生态安全及人类健康,已成为世界各国广泛关注和研究的热点.本文对外来杂草三裂叶豚草(Ambrosia trifida L.)的起源和分布、生物生态学特性、经济和生态影响及其控制管理措施等进行了系统综述.根据生物生态学特性、潜在风险及管理控制的难度等指标,初步建立了外来杂草的风险评估体系.应用该体系对三裂叶豚草进行了风险评估,得出其风险值为83,属高度危险的检疫性有害生物.

  12. Radiation damage of uranium

    International Nuclear Information System (INIS)

    Study of radiation damage covered the following: Kinetics of electric resistance of uranium and uranium alloy with 1% of molybdenum dependent on the second phase and burnup rate; Study of gas precipitation and diffusion of bubbles by transmission electron microscopy; Numerical analysis of the influence of defects distribution and concentration on the rare gas precipitation in uranium; study of thermal sedimentation of uranium alloy with molybdenum; diffusion of rare gas in metal by gas chromatography method

  13. Governing uranium in China

    OpenAIRE

    Patton Schell, Tamara

    2014-01-01

    Nuclear power is playing an increasingly prominent role in China's long-term strategic energy calculus. In response, China is responding by producing more uranium domestically, buying more uranium on the international market, and investing heavily in overseas uranium properties. At the same time, China has been updating its nuclear regulations over the last three decades, resulting in a myriad of regulatory agencies with widely varying responsibilities related to implementing uranium regulati...

  14. Uranium in fossil bones

    International Nuclear Information System (INIS)

    An attempt has been made to determine the uranium content and thus the age of certain fossil bones Haritalyangarh (Himachal Pradesh), India. The results indicate that bones rich in apatite are also rich in uranium, and that the radioactivity is due to radionuclides in the uranium series. The larger animals apparently have a higher concentration of uranium than the small. The dating of a fossil jaw (elephant) places it in the Pleistocene. (Auth.)

  15. Bicarbonate leaching of uranium

    International Nuclear Information System (INIS)

    The alkaline leach process for extracting uranium from uranium ores is reviewed. This process is dependent on the chemistry of uranium and so is independent on the type of mining system (conventional, heap or in-situ) used. Particular reference is made to the geochemical conditions at Crownpoint. Some supporting data from studies using alkaline leach for remediation of uranium-contaminated sites is presented

  16. Uranium mining: Saskatchewan status

    International Nuclear Information System (INIS)

    This paper gives the status of uranium mining by Areva in Saskatchewan. Uranium production now meets 85% of world demand for power generation. 80% of world production of uranium comes from top 5 countries: Kazakhstan, Canada, Australia, Niger and Namibia. Saskatchewan is currently the only Canadian province with active uranium mines and mills and the largest exploration programs. Several mine projects are going through the environmental assessment process. Public opinion is in favour of mining activities in Saskatchewan.

  17. Uranium resources, 1983

    International Nuclear Information System (INIS)

    The specific character of uranium as energy resources, the history of development of uranium resources, the production and reserve of uranium in the world, the prospect regarding the demand and supply of uranium, Japanese activity of exploring uranium resources in foreign countries and the state of development of uranium resources in various countries are reported. The formation of uranium deposits, the classification of uranium deposits and the reserve quantity of each type are described. As the geological environment of uranium deposits, there are six types, that is, quartz medium gravel conglomerate deposit, the deposit related to the unconformity in Proterozoic era, the dissemination type magma deposit, pegmatite deposit and contact deposit in igneaus rocks and metamorphic rocks, vein deposit, sandstone type deposit and the other types of deposit. The main features of respective types are explained. The most important uranium resources in Japan are those in the Tertiary formations, and most of the found reserve belongs to this type. The geological features, the state of yield and the scale of the deposits in Ningyotoge, Tono and Kanmon Mesozoic formation are reported. Uranium minerals, the promising districts in the world, and the matters related to the exploration and mining of uranium are described. (Kako, I.)

  18. Uranium and thorium

    International Nuclear Information System (INIS)

    Present article is devoted to uranium and thorium content in fluorite. In order to obtain the comprehensive view on uranium and thorium distribution in fluorite 100 fluorite samples of various geologic deposits and ores of Kazakhstan, Uzbekistan, Tajikistan and some geologic deposits of Russia were studied. The uranium and thorium content in fluorite of geologic deposits of various mineralogical and genetic type was defined.

  19. Koontz Lake

    OpenAIRE

    Zebell, Dennis A; Medors, Sky K; Delgado, Dan G

    2013-01-01

    A case study of the SR 23 replacement at the Koontz Lake Dam will be presented. The dam replacement, road re-alignment, and labyrinth spillway will be discussed. The design criteria and processes associated with each of those items will be discussed as well as the coordination with and expectations of the multiple owners involved with the project.

  20. ARBUSCULAR MYCORRHIZAL COLONIZATION OF LARREA TRIDENTATA AND AMBROSIA DUMOSA ROOTS VARIES WITH PRECIPITATION AND SEASON IN THE MOJAVE DESERT

    Energy Technology Data Exchange (ETDEWEB)

    M. E. APPLE; C. I. THEE; V. L. SMITH-LONGOZO; C. R. COGAR; C. E. WELLS; R. S. NOWAK

    2004-01-01

    The percentage of fine roots colonized by arbuscular mycorrhizal (AM) fungi varied with season and with species in the co-dominant shrubs Lurreu tridentutu and Ambrosia dumosu at a site adjacent to the Nevada Desert FACE (Free-Air CO{sub 2} Enrichment) Facility (NDFF) in the Mojave Desert. We excavated downward and outward from the shrub bases in both species to collect and examine fine roots (< 1.0 mm diameter) at monthly intervals throughout 2001 and from October 2002 to September 2003. Fungal structures became visible in cleared roots stained with trypan blue. We quantified the percent colonization of roots by AM fungi via the line intercept method. In both years and for both species, colonization was highest in fall, relatively low in spring when root growth began, increased in late spring, and decreased during summer drought periods. Increases in colonization during summer and fall reflect corresponding increases in precipitation. Spring mycorrhizal colonization is low despite peaks in soil water availability and precipitation, indicating that precipitation is not the only factor influencing mycorrhizal colonization. Because the spring decrease in mycorrhizal colonization occurs when these shrubs initiate a major flush of fine root growth, other phenological events such as competing demands for carbon by fine root initiation, early season shoot growth, and flowering may reduce carbon availability to the fungus, and hence decrease colonization. Another possibility is that root growth exceeds the rate of mycorrhizal colonization.

  1. Biogeochemistry of uranium minerals

    International Nuclear Information System (INIS)

    Cyclic behaviour in the earth's crust is probably easier to demonstrate for uranium than for most elements. The chenmical basis of that behaviour is described with the roles which organisms can play during their life and as organic residues - after their death. The way in which this behaviour has led to the redistribution of uranium in rocks (to form ore bodies in favourable cases) is considered together with the related topic of biogeochemical prospecting for uranium. Many of the same considerations are relevant to the recovery of uranium by leaching from broken rock and to the way in which the cycling of uranium may affect the environment. (Auth.)

  2. The recovering Dian Lake

    OpenAIRE

    Ai, Chi-Han

    2013-01-01

    Dian Lake, also known as Kunming Lake, is the largest freshwater lake in Yunnan Province. However, the value of tourism isn't a perpetual blessing for Dian Lake. Since 1980, due to the rapid urbanization in China, water pollution in Dian Lake has worsened year by year.

  3. Two uranium tailings management facilities

    International Nuclear Information System (INIS)

    Uranium tailings management facilities in Saskatchewan have undergone a host of regulatory changes in the last 50 years. The designs at these facilities reflect the influence of these changes. The designs at two of these facilities (Rabbit Lake Above Ground Facility and Deilmann lnpit Facility) are described in this paper. The Rabbit Lake above Ground tailings management facility (RLATMF) is a first generation (valley type) facility which was operated between 1975 and 1985. Tailings up to a depth of 23.5 m are contained behind two earthfill dams at this facility. The RLATMF is presently undergoing decommissioning, including cover placement on the tailings surface and slope flattening and rock riprap placement at the containment dams. The Deilmann Inpit TMF (DTMF) is a recently approved second generation facility. Tailings are deposited subaqueously in the 170 m deep mined-out Deilmann pit. The design at the DTMF includes an under drainage and partial side drainage system. Tailings are expected to fully consolidate to a low permeability (-7m/s) for timely decommissioning within 10 years of end of tailings deposition. (author)

  4. Uranium speciation in plants

    International Nuclear Information System (INIS)

    Detailed knowledge of the nature of uranium complexes formed after the uptake by plants is an essential prerequisite to describe the migration behavior of uranium in the environment. This study focuses on the determination of uranium speciation after uptake of uranium by lupine plants. For the first time, time-resolved laser-induced fluorescence spectroscopy and X-ray absorption spectroscopy were used to determine the chemical speciation of uranium in plants. Differences were detected between the uranium speciation in the initial solution (hydroponic solution and pore water of soil) and inside the lupine plants. The oxidation state of uranium did not change and remained hexavalent after it was taken up by the lupine plants. The chemical speciation of uranium was identical in the roots, shoot axis, and leaves and was independent of the uranium speciation in the uptake solution. The results indicate that the uranium is predominantly bound as uranyl(VI) phosphate to the phosphoryl groups. Dandelions and lamb's lettuce showed uranium speciation identical to lupine plants. (orig.)

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

    Science.gov (United States)

    2010-07-01

    ... 31 Money and Finance: Treasury 3 2010-07-01 2010-07-01 false Uranium feed; natural uranium feed... (Continued) OFFICE OF FOREIGN ASSETS CONTROL, DEPARTMENT OF THE TREASURY HIGHLY ENRICHED URANIUM (HEU) AGREEMENT ASSETS CONTROL REGULATIONS General Definitions § 540.317 Uranium feed; natural uranium feed....

  6. Submission to the Royal Commission on Health and Environmental Protection - Uranium Mining. Phase VII: public and worker health

    International Nuclear Information System (INIS)

    This submission is intended to provide a brief resume of Elliot Lake's uranium mining/milling history, particularly with respect to the adverse effects on workers' health and the environment in general. Elliot Lake has pioneered various uranium mining and processing techniques. Its operations have also been directly linked with death and incapacities of workers and considerable destruction of the surrounding environment. The union believes that many unknowns continue to exist and that considerable research is required before various answers are available. It is for for these reasons that the union approaches uranium mining expansion and new developments with extreme caution

  7. Development of the disposal technology research component of the national uranium tailings program

    International Nuclear Information System (INIS)

    The National Technical Planning Group on Uranium Tailings Research, organized by CANMET in 1980, recommended the establishment of a National Uranium Tailings Program to develop research on the long-term abandonment of uranium mine tailings. This report deals with the disposal technology component of this program and attempts to provide recommendations with respect to potential research avenues in this area. A description of uranium tailings in Canada is provided in order to identify the current situation with uranium tailings management. Uranium mining sites described include the Elliot Lake and Bancroft area of Ontario, the northern Saskatchewan properties and the two abandoned sites in the North West Territories. The description of the sites was facilitated by subdividing the tailings into inactive sites, active sites, new tailings sites and areas of tailings in a close-out situation. Methods identified as promising include subsurface disposal, in-situ leaching, prevention of pyrite oxidation and reclamation studies at abandoned sites

  8. Bathymetry of Lake Ontario

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Ontario has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  9. Designated Wildlife Lakes - points

    Data.gov (United States)

    Minnesota Department of Natural Resources — This is a point shapefile of Designated Wildlife Lakes in Minnesota. This shapefile was created by converting lake polygons from the Designated Wildlife Lakes...

  10. Bathymetry of Lake Michigan

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Michigan has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  11. Bathymetry of Lake Huron

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  12. Hydrography - Lakes Assessments - Attaining

    Data.gov (United States)

    NSGIC GIS Inventory (aka Ramona) — This layer shows only attaining lakes of the Integrated List. The Lakes Integrated List represents lake assessments in an integrated format for the Clean Water Act...

  13. Bathymetry of Lake Superior

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Superior has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and make it more...

  14. Great Lakes Bathymetry

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lakes Michigan, Erie, Saint Clair, Ontario and Huron has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological...

  15. Radioactivity levels in waters and sediments from Van Lake / Turkey

    International Nuclear Information System (INIS)

    It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements dissolved and particulate phases in aquatic systems. Significant radiation doses to man can potentially occur following radioactive contamination of water bodies such as rivers, lakes and reservoirs. In the long term, radioactivity in the water body can remain at significant levels as a result of secondary contamination processes. The Van Lake is located at Eastern part of Turkey and it is largest Lake of Turkey. The purpose of this study is to measure natural radioactivity in the waters and sediments taken from along to shore of Van Lake. Total of 19 surface coast lake waters and 18 sediments samples were collected from Van Lake in dry season in 2005, in the first part of this Project. In surface lake water samples, pH, mV and conductivity values were measured and alkalinity content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. Radioactivities related to gross radium isotopes, gross-α and gross-β radioactivity levels in the surface water were determined. Gross radium isotopes were separated using the barium sulphate co-precipitation method and then the radioactivity of gross radium isotopes was measured by ZnS(Ag) alpha scintillation counter. The correlation among measured parameters for water samples and concentrations of uranium and gross radium isotopes are also discussed. Natural radioactivity in the sediments was also determined by gamma spectrometer. The field and laboratory studies on this project are carried out

  16. The infestation by an exotic ambrosia beetle, Euplatypus parallelus (F. (Coleoptera: Curculionidae: Platypodinae of Angsana trees (Pterocarpus indicus Willd. in southern Thailand

    Directory of Open Access Journals (Sweden)

    Sara Bumrungsri

    2008-07-01

    Full Text Available An exotic ambrosia beetle, Euplatypus parallelus (F. was collected from infested Pterocarpus indicus Willd. trees in Prince of Songkla University. Larvae and eggs were found in simple galleries with a single branch. Either a single male or a male and a female were found in each gallery. Half of these infested trees were previously attacked by long-horned beetles probably Aristobia horridula (Hope (Coleoptera: Cerambycidae, while some of them appeared to be healthy. Fusarium oxysporum Schlecht.:Fr. was isolated from frass, sapwood samples and insect larvae, and might be a cause of death of P.indicus.

  17. Record uranium sales reported by Eldorado Nuclear

    International Nuclear Information System (INIS)

    Short communication. Full text included in abstract. With sales up 66% to $335 million last year from $202 million in 1986, Eldorado Nuclear Ltd. of Ottawa moved into the black in 1987 reporting a profit of $12 million. This compared with a loss of $64.4 million in the previous year. The Crown-owned company's operating profit leaped 150% to $109 million from $44 million a year earlier. Chairman George Bonar ascribed the large gap between operating and final profits to costs incurred borrowing foreign funds in previous years to finance a $500 million capital expansion. He said costs associated with the loans amounted to $95 million last year. Mr. Bonar attributed the strong turnaround to record sales to Canadian and foreign electrical utilities and company-wide reductions. The 9.7 million pounds of uranium concentrates sold last year was 111% higher than the 4.6 million pounds sold in 1986. Largely due to higher output at Eldorado's Rabbit Lake facility, production at this and the Key Lake mines in northern Saskatchewan spurted 51% to 3,062 metric tons. While setting new production records, Eldorado's uranium processing operations at Blind River and Port Hope, Ontario trimmed unit costs by 12%. Compared with the previous record output of 8,239 tons set in 1986, the volume of uranium processed rose 32% to 10,897 tons. At the end of 1987, reserves totalled about 175 million pounds of uranium oxide, Mr. Bonar said. This compared with 30 million pounds prior to the capital expansion in 1981. All dollar figures are in Canadian funds

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

    International Nuclear Information System (INIS)

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

  19. Uranium hexafluoride public risk

    Energy Technology Data Exchange (ETDEWEB)

    Fisher, D.R.; Hui, T.E.; Yurconic, M.; Johnson, J.R.

    1994-08-01

    The limiting value for uranium toxicity in a human being should be based on the concentration of uranium (U) in the kidneys. The threshold for nephrotoxicity appears to lie very near 3 {mu}g U per gram kidney tissue. There does not appear to be strong scientific support for any other improved estimate, either higher or lower than this, of the threshold for uranium nephrotoxicity in a human being. The value 3 {mu}g U per gram kidney is the concentration that results from a single intake of about 30 mg soluble uranium by inhalation (assuming the metabolism of a standard person). The concentration of uranium continues to increase in the kidneys after long-term, continuous (or chronic) exposure. After chronic intakes of soluble uranium by workers at the rate of 10 mg U per week, the concentration of uranium in the kidneys approaches and may even exceed the nephrotoxic limit of 3 {mu}g U per gram kidney tissue. Precise values of the kidney concentration depend on the biokinetic model and model parameters assumed for such a calculation. Since it is possible for the concentration of uranium in the kidneys to exceed 3 {mu}g per gram tissue at an intake rate of 10 mg U per week over long periods of time, we believe that the kidneys are protected from injury when intakes of soluble uranium at the rate of 10 mg U per week do not continue for more than two consecutive weeks. For long-term, continuous occupational exposure to low-level, soluble uranium, we recommend a reduced weekly intake limit of 5 mg uranium to prevent nephrotoxicity in workers. Our analysis shows that the nephrotoxic limit of 3 {mu}g U per gram kidney tissues is not exceeded after long-term, continuous uranium intake at the intake rate of 5 mg soluble uranium per week.

  20. The uranium potential of the Bushveld igneous complex

    International Nuclear Information System (INIS)

    A review of published literature supported by field observations on the uranium potential of the Bushveld Complex indicates that this geological region may host deposits with reserves in the range of a few thousand tons U3O8. The possibility that the Bushveld Complex or its cover rocks hosts, or has ever hosted in the past, giant uranium deposits such as those of Olympic Dam, Key Lake, Jabiluka or Rossing is considered to be unlikely. The potential for volcanogenic, caldera-type deposits in the Rooiberg Felsites remains at present untested. Recommendations for research currently sponsored by the AEC at the University of Pretoria are presented

  1. Uranium production, exploration and mine development in Canada

    International Nuclear Information System (INIS)

    Full text: Full text: Canada has been the world leader in uranium production since the early 1990's and production in 2005 was 11,629 te U. The Elliott Lake region of Ontario was once the centre of production, but after the last facilities closed in 1996, all production now comes from the Athabasca Basin in northern Saskatchewan. Average grades of the world's two largest high grade deposits at McArthur River and Cigar Lake are 10 to 100 times the grade of deposits mined elsewhere. McArthur River has been in production since late 1999 and first production from Cigar Lake is expected in 2007. If all expansion and probable mine openings come to fruition, annual Canadian production could amount to 16,000 te U by 2011. All currently operating uranium mines have been the subject of a comprehensive environmental assessment and review process. Uranium mining brings significant benefits to local area residents in northern Saskatchewan. Residents of northern Saskatchewan are active participants in Environmental Quality Committees. Recent survey results show the majority of Saskatchewan residents support the continuation of uranium mining in the province. The closed uranium mines in Canada have been successfully decommissioned and rehabilitated in particular in the Elliott Lake region of Ontario. The principle exploration target in Canada remains the Athabasca Basin, but activity has also been reported in several of the other territories and provinces. Natural Resources Canada estimates that some $CAN81M was spent on exploration in Canada in 2005. Under the Canadian Constitution, natural resources are owned by the provinces or by the federal government if they are on federal lands north of 600C latitude. The provinces have jurisdiction over exploration activities within their borders and for most commodities have jurisdiction over mine development and production, operations, health and safety and environmental matters. Once a company starts to develop a deposit into a mine it

  2. Microbial interactions with uranium: implications for uranium bioremediation

    International Nuclear Information System (INIS)

    Accidental release of uranium into the environment has the potential of inducing chemical and radiological toxicity. In situ bioremediation of uranium by microbial processes has been shown to be effective for immobilizing uranium in contaminated sites. Such microbial processes are important components of biogeochemical cycles and regulate the mobility and fate of uranium in the environment. This talk focuses on the spectrum of mechanisms displayed by various microorganisms in order to alleviate uranium toxicity which forms the basis of uranium bioremediation. (author)

  3. Uranium enrichment. Principles

    International Nuclear Information System (INIS)

    Uranium enrichment industry is a more than 60 years old history and has developed without practically no cost, efficiency or profit constraints. However, remarkable improvements have been accomplished since the Second World War and have led to the development of various competing processes which reflect the diversity of uranium compositions and of uranium needs. Content: 1 - general considerations: uranium isotopes, problem of uranium enrichment, first realizations (USA, Russia, Europe, Asia, other countries), present day situation, future needs and market evolution; 2 - principles of isotopic separation: processes classification (high or low enrichment), low elementary enrichment processes, equilibrium time, cascade star-up and monitoring, multi-isotopes case, uranium reprocessing; 3 - enrichment and proliferation. (J.S.)

  4. Uranium Newsletter. No. 1

    International Nuclear Information System (INIS)

    The new Uranium Newsletter is presented as an IAEA annual newsletter. The organization of the IAEA and its involvement with uranium since its founding in 1957 is described. The ''Red Book'' (Uranium Resources, Production and Demand) is mentioned. The Technical Assistance Programme of the IAEA in this field is also briefly mentioned. The contents also include information on the following meetings: The Technical Committee Meeting on Uranium Deposits in Magmatic and Metamorphic Rocks, Advisory Group Meeting on the Use of Airborne Radiometric Data, and the Technical Committee Meeting on Metallogenesis. Recent publications are listed. Current research contracts in uranium exploration are mentioned. IAEA publications on uranium (in press) are listed also. Country reports from the following countries are included: Australia, Brazil, Canada, China (People's Republic of), Denmark, Finland, Germany (Federal Republic of), Malaysia, Philippines, Portugal, South Africa (Republic of), Spain, Syrian Arab Republic, United Kingdom, United States of America, Zambia, and Greece. There is also a report from the Commission of European Communities

  5. Uses of depleted uranium

    International Nuclear Information System (INIS)

    The depleted uranium is that in which percentage of uranium-235 fission executable is less than 0.2% or 0.3%. It is usually caused by the process of reprocessing the nuclear fuel burning, and also mixed with some other radioactive elements such as uranium 236, 238 and plutonium 239. The good features of the depleted uranium are its high density, low price and easily mined. So, the specifications for depleted uranium make it one of the best materials in case you need to have objects small in size, but quite heavy regarding its size. Uses of deplet ed uranium were relatively increased in domestic industrial uses as well as some uses in nuclear industry in the last few years. So it has increased uses in many areas of military and peaceful means such as: in balancing the giant air crafts, ships and missiles and in the manufacture of some types of concrete with severe hardness. (author)

  6. Uranium purchases report 1992

    International Nuclear Information System (INIS)

    Data reported by domestic nuclear utility companies in their responses to the 1991 and 1992 ''Uranium Industry Annual Survey,'' Form EIA-858, Schedule B ''Uranium Marketing Activities,are provided in response to the requirements in the Energy Policy Act 1992. Data on utility uranium purchases and imports are shown on Table 1. Utility enrichment feed deliveries and secondary market acquisitions of uranium equivalent of US DOE separative work units are shown on Table 2. Appendix A contains a listing of firms that sold uranium to US utilities during 1992 under new domestic purchase contracts. Appendix B contains a similar listing of firms that sold uranium to US utilities during 1992 under new import purchase contracts. Appendix C contains an explanation of Form EIA-858 survey methodologies with emphasis on the processing of Schedule B data

  7. Geochemical exploration for uranium

    International Nuclear Information System (INIS)

    This Technical Report is designed mainly to introduce the methods and techniques of uranium geochemical exploration to exploration geologists who may not have had experience with geochemical exploration methods in their uranium programmes. The methods presented have been widely used in the uranium exploration industry for more than two decades. The intention has not been to produce an exhaustive, detailed manual, although detailed instructions are given for a field and laboratory data recording scheme and a satisfactory analytical method for the geochemical determination of uranium. Rather, the intention has been to introduce the concepts and methods of uranium exploration geochemistry in sufficient detail to guide the user in their effective use. Readers are advised to consult general references on geochemical exploration to increase their understanding of geochemical techniques for uranium

  8. A new approach used to explore associations of current Ambrosia pollen levels with current and past meteorological elements.

    Science.gov (United States)

    Matyasovszky, István; Makra, László; Csépe, Zoltán; Deák, Áron József; Pál-Molnár, Elemér; Fülöp, Andrea; Tusnády, Gábor

    2015-09-01

    The paper examines the sensitivity of daily airborne Ambrosia (ragweed) pollen levels of a current pollen season not only on daily values of meteorological variables during this season but also on the past meteorological conditions. The results obtained from a 19-year data set including daily ragweed pollen counts and ten daily meteorological variables are evaluated with special focus on the interactions between the phyto-physiological processes and the meteorological elements. Instead of a Pearson correlation measuring the strength of the linear relationship between two random variables, a generalised correlation that measures every kind of relationship between random vectors was used. These latter correlations between arrays of daily values of the ten meteorological elements and the array of daily ragweed pollen concentrations during the current pollen season were calculated. For the current pollen season, the six most important variables are two temperature variables (mean and minimum temperatures), two humidity variables (dew point depression and rainfall) and two variables characterising the mixing of the air (wind speed and the height of the planetary boundary layer). The six most important meteorological variables before the current pollen season contain four temperature variables (mean, maximum, minimum temperatures and soil temperature) and two variables that characterise large-scale weather patterns (sea level pressure and the height of the planetary boundary layer). Key periods of the past meteorological variables before the current pollen season have been identified. The importance of this kind of analysis is that a knowledge of the past meteorological conditions may contribute to a better prediction of the upcoming pollen season. PMID:25376632

  9. A new approach used to explore associations of current Ambrosia pollen levels with current and past meteorological elements

    Science.gov (United States)

    Matyasovszky, István; Makra, László; Csépe, Zoltán; Deák, Áron József; Pál-Molnár, Elemér; Fülöp, Andrea; Tusnády, Gábor

    2015-09-01

    The paper examines the sensitivity of daily airborne Ambrosia (ragweed) pollen levels of a current pollen season not only on daily values of meteorological variables during this season but also on the past meteorological conditions. The results obtained from a 19-year data set including daily ragweed pollen counts and ten daily meteorological variables are evaluated with special focus on the interactions between the phyto-physiological processes and the meteorological elements. Instead of a Pearson correlation measuring the strength of the linear relationship between two random variables, a generalised correlation that measures every kind of relationship between random vectors was used. These latter correlations between arrays of daily values of the ten meteorological elements and the array of daily ragweed pollen concentrations during the current pollen season were calculated. For the current pollen season, the six most important variables are two temperature variables (mean and minimum temperatures), two humidity variables (dew point depression and rainfall) and two variables characterising the mixing of the air (wind speed and the height of the planetary boundary layer). The six most important meteorological variables before the current pollen season contain four temperature variables (mean, maximum, minimum temperatures and soil temperature) and two variables that characterise large-scale weather patterns (sea level pressure and the height of the planetary boundary layer). Key periods of the past meteorological variables before the current pollen season have been identified. The importance of this kind of analysis is that a knowledge of the past meteorological conditions may contribute to a better prediction of the upcoming pollen season.

  10. North American Lauraceae: terpenoid emissions, relative attraction and boring preferences of redbay ambrosia beetle, Xyleborus glabratus (coleoptera: curculionidae: scolytinae.

    Directory of Open Access Journals (Sweden)

    Paul E Kendra

    Full Text Available The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia and swampbay (P. palustris trees in the southeastern USA, threatens avocado (P. americana production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race, redbay, swampbay, silkbay (Persea humilis, California bay laurel (Umbellularia californica, sassafras (Sassafras albidum, northern spicebush (Lindera benzoin, camphor tree (Cinnamomum camphora, and lancewood (Nectandra coriacea. In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and

  11. Effects of elevated CO2 on biomass and fungi associated with two ecotypes of ragweed (Ambrosia artemisiifolia L.).

    Science.gov (United States)

    Runion, G Brett; Prior, Stephen A; Price, Andrew J; McElroy, J Scott; Torbert, H Allen

    2014-01-01

    Herbicide resistant weed populations have developed due to the repeated application of herbicides. Elevated concentrations of atmospheric CO2 can have positive effects on weed growth, but how rising CO2 might affect herbicide resistant weeds is not known. Ragweed (Ambrosia artemisiifolia L.) ecotypes known to be resistant or susceptible to glyphosate herbicide were exposed to either ambient or elevated (ambient +200 μ mol mol(-1)) concentrations of CO2 in open top chambers. Plants were harvested following 8 weeks of CO2 exposure; at this time, they had begun to exhibit disease symptoms including spots on leaves and stems. Elevated CO2 significantly increased top, root, and total plant biomass. Also, glyphosate resistant plants had significantly greater top, root, and total biomass than plants susceptible to the herbicide. There were no significant CO2 by ecotype interactions. Fungi from 13 genera were associated with ragweed, several of which can be either pathogens (i.e., Alternaria, Fusarium, Rhizoctonia), aiding the decline in health of the ragweed plants, or saprophytes existing on dead plant tissues. The common foliar disease powdery mildew was significantly higher on susceptible compared with resistant ragweed. Susceptible plants also showed an increased frequency of Rhizoctonia on leaves and Alternaria on stems; however, Fusarium occurred more frequently on resistant ragweed leaves. Fungi were not affected by CO2 concentration or its interaction with ecotype. This study reports the first information on the effects of elevated CO2 on growth of herbicide resistant weeds. This is also the first study examining the impact of herbicide resistance and elevated CO2 on fungi associated with weeds. What effects herbicide resistance might have on plant diseases and how rising atmospheric CO2 might impact these effects needs to be addressed, not only with important weeds but also with crops. PMID:25309569

  12. Fusarium euwallaceae sp. nov.--a symbiotic fungus of Euwallacea sp., an invasive ambrosia beetle in Israel and California.

    Science.gov (United States)

    Freeman, S; Sharon, M; Maymon, M; Mendel, Z; Protasov, A; Aoki, T; Eskalen, A; O'Donnell, K

    2013-01-01

    The invasive Asian ambrosia beetle Euwallacea sp. (Coleoptera, Scolytinae, Xyleborini) and a novel Fusarium sp. that it farms in its galleries as a source of nutrition causes serious damage to more than 20 species of live trees and pose a serious threat to avocado production (Persea americana) in Israel and California. Adult female beetles are equipped with mandibular mycangia in which its fungal symbiont is transported within and from the natal galleries. Damage caused to the xylem is associated with disease symptoms that include sugar or gum exudates, dieback, wilt and ultimately host tree mortality. In 2012 the beetle was recorded on more than 200 and 20 different urban landscape species in southern California and Israel respectively. Euwallacea sp. and its symbiont are closely related to the tea shot-hole borer (E. fornicatus) and its obligate symbiont, F. ambrosium occurring in Sri Lanka and India. To distinguish these beetles, hereafter the unnamed xyleborine in Israel and California will be referred to as Euwallacea sp. IS/CA. Both fusaria exhibit distinctive ecologies and produce clavate macroconidia, which we think might represent an adaption to the species-specific beetle partner. Both fusaria comprise a genealogically exclusive lineage within Clade 3 of the Fusarium solani species complex (FSSC) that can be differentiated with arbitrarily primed PCR. Currently these fusaria can be distinguished only phenotypically by the abundant production of blue to brownish macroconidia in the symbiont of Euwallacea sp. IS/CA and their rarity or absence in F. ambrosium. We speculate that obligate symbiosis of Euwallacea and Fusarium, might have driven ecological speciation in these mutualists. Thus, the purpose of this paper is to describe and illustrate the novel, economically destructive avocado pathogen as Fusarium euwallaceae sp. nov. S. Freeman et al. PMID:23928415

  13. North American Lauraceae: terpenoid emissions, relative attraction and boring preferences of redbay ambrosia beetle, Xyleborus glabratus (coleoptera: curculionidae: scolytinae).

    Science.gov (United States)

    Kendra, Paul E; Montgomery, Wayne S; Niogret, Jerome; Pruett, Grechen E; Mayfield, Albert E; MacKenzie, Martin; Deyrup, Mark A; Bauchan, Gary R; Ploetz, Randy C; Epsky, Nancy D

    2014-01-01

    The invasive redbay ambrosia beetle, Xyleborus glabratus, is the primary vector of Raffaelea lauricola, a symbiotic fungus and the etiologic agent of laurel wilt. This lethal disease has caused severe mortality of redbay (Persea borbonia) and swampbay (P. palustris) trees in the southeastern USA, threatens avocado (P. americana) production in Florida, and has potential to impact additional New World species. To date, all North American hosts of X. glabratus and suscepts of laurel wilt are members of the family Lauraceae. This comparative study combined field tests and laboratory bioassays to evaluate attraction and boring preferences of female X. glabratus using freshly-cut bolts from nine species of Lauraceae: avocado (one cultivar of each botanical race), redbay, swampbay, silkbay (Persea humilis), California bay laurel (Umbellularia californica), sassafras (Sassafras albidum), northern spicebush (Lindera benzoin), camphor tree (Cinnamomum camphora), and lancewood (Nectandra coriacea). In addition, volatile collections and gas chromatography-mass spectroscopy (GC-MS) were conducted to quantify terpenoid emissions from test bolts, and electroantennography (EAG) was performed to measure olfactory responses of X. glabratus to terpenoids identified by GC-MS. Significant differences were observed among treatments in both field and laboratory tests. Silkbay and camphor tree attracted the highest numbers of the beetle in the field, and lancewood and spicebush the lowest, whereas boring activity was greatest on silkbay, bay laurel, swampbay, and redbay, and lowest on lancewood, spicebush, and camphor tree. The Guatemalan cultivar of avocado was more attractive than those of the other races, but boring response among the three was equivalent. The results suggest that camphor tree may contain a chemical deterrent to boring, and that different cues are associated with host location and host acceptance. Emissions of α-cubebene, α-copaene, α-humulene, and calamenene were

  14. Cubeb Oil Lures: Terpenoid Emissions, Trapping Efficacy, and Longevity for Attraction of Redbay Ambrosia Beetle (Coleoptera: Curculionidae: Scolytinae).

    Science.gov (United States)

    Kendra, Paul E; Niogret, Jerome; Montgomery, Wayne S; Deyrup, Mark A; Epsky, Nancy D

    2015-02-01

    Redbay ambrosia beetle, Xyleborus glabratus Eichhoff, is an exotic wood borer and the primary vector of Raffaelea lauricola, a symbiotic fungus that causes laurel wilt. This lethal disease has decimated native redbay [Persea borbonia (L.) Sprengel] and swampbay [Persea palustris (Rafinesque) Sargent] throughout southeastern U.S. forests, and currently threatens avocado (Persea americana Miller) in Florida. To curtail the spread of laurel wilt, effective attractants are needed for early detection of the vector. Phoebe oil lures were the best known attractant for X. glabratus, but they are no longer available. The current detection system uses manuka oil lures, but previous research indicated that manuka lures have a short field life in Florida. Recently, cubeb oil was identified as a new attractant for X. glabratus, and cubeb bubble lures are now available commercially. This study compared trapping efficacy and field longevity of cubeb and manuka lures with phoebe lures that had been in storage since 2010 over a 12-wk period in south Florida. In addition, terpenoid emissions were quantified from cubeb and manuka lures aged outdoors for 12 wk. Captures were comparable with all three lures for 3 wk, but by 4 wk, captures with manuka were significantly less. Equivalent captures were obtained with cubeb and phoebe lures for 7 wk, but captures with cubeb were significantly greater from 8 to 12 wk. Our results indicate that cubeb bubble lures are the most effective tool currently available for detection of X. glabratus, with a field life of 3 months due to extended low release of attractive sesquiterpenes, primarily α-copaene and α-cubebene. PMID:26470139

  15. Uranium: A Dentist's perspective

    OpenAIRE

    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 repla...

  16. Uranium in Canada

    International Nuclear Information System (INIS)

    In 1974 the Minister of Energy, Mines and Resources (EMR) established a Uranium Resource Appraisal Group (URAG) within EMR to audit annually Canada's uranium resources for the purpose of implementing the federal government's uranium export policy. A major objective of this policy was to ensure that Canadian uranium supplies would be sufficient to meet the needs of Canada's nuclear power program. As projections of installed nuclear power growth in Canada over the long term have been successively revised downwards (the concern about domestic security of supply is less relevant now than it was 10 years ago) and as Canadian uranium supply capabilities have expanded significantly. Canada has maintained its status as the western world's leading exporter of uranium and has become the world's leading producer. Domestic uranium resource estimates have increased to 551 000 tonnes U recoverable from mineable ore since URAG completed its last formal assessment (1982). In 1984, Canada's five primary uranium producers employed some 5800 people at their mining and milling operations, and produced concentrates containing some 11 170 tU. It is evident from URAG's 1984 assessment that Canada's known uranium resources, recoverable at uranium prices of $150/kg U or less, are more than sufficient to meet the 30-year fuelling requirements of those reactors that are either in opertaion now or committed or expected to be in-service by 1995. A substantial portion of Canada's identified uranium resources, recoverable within the same price range, is thus surplus to Canadian needs and available for export. Sales worth close to $1 billion annually are assured. Uranium exploration expenditures in Canada in 1983 and 1984 were an estimated $41 million and $35 million, respectively, down markedly from the $128 million reported for 1980. Exploration drilling and surface development drilling in 1983 and 1984 were reported to be 153 000 m and 197 000 m, respectively, some 85% of which was in

  17. Uranium industry annual, 1988

    International Nuclear Information System (INIS)

    This report presents data on US uranium raw materials and marketing activities of the domestic uranium industry. It contains aggregated data reported by US companies on the ''Uranium Industry Annual Survey'' (1988), Form EIA-858, and historical data from prior data collections and other pertinent sources. The report was prepared by the Energy Information Administration (EIA), the independent agency for data collection and analysis with the US Department of Energy

  18. Biogeochemistry of uranium

    International Nuclear Information System (INIS)

    The possible receipt of uranium from poor ores with application of biotechnology and use of microorganisms is presented. A particular attention is paid to mechanisms of bacterium leaching of uranium and to factors that influence the efficiency of this process and also, to tolerance of microorganisms to toxic metals. Processes of uranium biosorption from a sea water by algae, mushrooms and bacteria are also described. 36 refs. (author)

  19. Simulating distinguish enriched uranium from depleted uranium by activation method

    International Nuclear Information System (INIS)

    Detecting uranium material is an important work in arms control Active detection is an efficient method for uranium material. The paper focuses on the feasibility that can distinguish the enriched uranium and the depleted uranium by MCNP program. It can distinguish the enriched uranium and the depleted uranium by the curve of relationship between fission rate of uranium material and thickness of moderator.Advantages of 252Cf and 14 MeV neutron sources are discussed in detecting uranium material through calculation. The results show that 252Cf neutron source is better than 14 MeV one. Delayed neutrons are more easily detected than delayed gamma ray at measurement aspect. (authors)

  20. CHEMICAL TOXICITY OF URANIUM

    OpenAIRE

    2007-01-01

    Uranium, occurs naturally in the earth’s crust, is an alpha emitter radioactive element from the actinide group. For this reason, U-235 and U-238, are uranium isotopes with long half lives, have got radiological toxicity. But, for natural-isotopic-composition uranium (NatU), there is greater risk from chemical toxicity than radiological toxicity. When uranium is get into the body with anyway, also its chemical toxicity must be thought. [TAF Prev Med Bull 2007; 6(3.000): 215-220

  1. Uranium and drinking water

    International Nuclear Information System (INIS)

    Uranium is provoking public anxiety based on the radioactivity of several isotopes and the connection to nuclear technology. Drinking water contains at the most geogenic uranium in low concentrations that might be interesting in the frame of chemical of toxicology, but not due to radiological impact. The contribution gives an overview on the uranium content in drinking water and health effects for the human population based on animal tests. These experiments indicate a daily tolerable intake of 0.2 microgram per kg body mass. The actual limiting value for uranium in drinking water is 0.3 microgram per kg body mass water (drinking water regulation from 2001).

  2. CHEMICAL TOXICITY OF URANIUM

    Directory of Open Access Journals (Sweden)

    Sermin Cam

    2007-06-01

    Full Text Available Uranium, occurs naturally in the earth’s crust, is an alpha emitter radioactive element from the actinide group. For this reason, U-235 and U-238, are uranium isotopes with long half lives, have got radiological toxicity. But, for natural-isotopic-composition uranium (NatU, there is greater risk from chemical toxicity than radiological toxicity. When uranium is get into the body with anyway, also its chemical toxicity must be thought. [TAF Prev Med Bull 2007; 6(3.000: 215-220

  3. International trade in uranium

    International Nuclear Information System (INIS)

    Two reports are presented; one has been prepared by the Uranium Institute and is submitted by the United Kingdom delegation, the other by the United States delegation. The report of the Uranium Institute deals with the influence of the government on international trade in uranium. This influence becomes apparent predominantly by export and import restrictions, as well as by price controls. The contribution submitted by the United States is a uranium market trend analysis, with pricing methods and contracting modes as well as the effect of government policies being investigated in the light of recent developments

  4. Phospholyl-uranium complexes

    International Nuclear Information System (INIS)

    After having reported a bibliographical study on penta-methylcyclopentadienyl uranium complexes, and a description of the synthesis and radioactivity of uranium (III) and (IV) boron hydrides compounds, this research thesis reports the study of mono and bis-tetramethyl-phospholyl uranium complexes comprising chloride, boron hydride, alkyl and alkoxide ligands. The third part reports the comparison of structures, stabilities and reactions of homologue complexes in penta-methylcyclopentadienyl and tetramethyl-phospholyl series. The last part addresses the synthesis of tris-phospholyl uranium (III) and (IV) complexes.

  5. Uranium production from phosphates

    International Nuclear Information System (INIS)

    According to estimates of the world's uranium consumption, exploitation of most rich sources is expected by the 1980's. Forecasts show that the rate of uranium consumption will increase towards the end of the century. It is therefore desirable to exploit poor sources not yet in use. In the near future, the most reasonable source for developing uranium is phosphate rock. Uranium reserves in phosphates are estimated at a few million tons. Production of uranium from phosphates is as a by-product of phosphate rock processing and phosphoric acid production; it will then be possible to save the costs incurred in crushing and dissolving the rock when calculating uranium production costs. Estimates show that the U.S. wastes about 3,000 tons of uranium per annum in phosphoric acid based fertilisers. Studies have also been carried out in France, Yugoslavia and India. In Israel, during the 1950's, a small plant was operated in Haifa by 'Chemical and Phosphates'. Uranium processes have also been developed by linking with the extraction processes at Arad. Currently there is almost no activity on this subject because there are no large phosphoric acid plants which would enable production to take place on a reasonable scale. Discussions are taking place about the installation of a plant for phosphoric acid production utilising the 'wet process', producing 200 to 250,000 tons P2O5 per annum. It is necessary to combine these facilities with uranium production plant. (author)

  6. Heating uranium alloy billets

    International Nuclear Information System (INIS)

    Data were obtained for the surface heat transfer coefficient of uranium and the alloys of uranium-0.75 wt percent titanium, uranium-6 wt percent niobium, and uranium-7.5 wt percent niobium-2.5 wt percent zirconium. Samples were heated to 8500C in both a molten salt bath and an argon-purged air furnace, then the samples were cooled in air. Surface heat transfer coefficients were calculated from the experimental data for both heating and cooling of the metals. 4 fig, 4 tables

  7. Environmental conditions of two abandoned uranium mill tailings sites in northern Saskatchewan

    International Nuclear Information System (INIS)

    Two abandoned uranium mill tailings sites near Uranium City, Saskatchewan, have been studied in an attempt to follow the natural rehabilitation processes. The Gunnar site is a largely terrestrial environment while the Lorado mill tailings were discharged mainly into Nero Lake. This report describes the ecological conditions of both sites, potential long-term environmental degradation, and possible measures to assist the recovery of both areas

  8. Detection of ambrosia beetles using a pan-sharpened image generated from ALOS/AVNIR-2 and ALOS/PRISM imagery

    Directory of Open Access Journals (Sweden)

    Rei Sonobe

    2014-03-01

    Full Text Available Aim of study: The ambrosia beetle, Platypus quercivorus, is a vector of Japanese oak wilt, which causes massive mortality of oak trees in Japan. ALOS/AVNIR-2 true color images can be used to help detect areas of oak wilt, although such detection by inventory surveys is not realistic. Applying pan-sharpening techniques, a higher spatial resolution multispectral image can be generated from lower-resolution multispectral images and higher-resolution panchromatic images. In this study, some pan-sharpening algorithms were considered and evaluated for the detection of damage points.Area of study: The oak forests in Kanazawa prefecture, Japan.Materials and methods: The ALOS/AVNIR-2 and ALOS/PRISM sensors were used. The pan-sharpening algorithms adopted were: Brovey transformation, Modified IHS transformation, Wavelet transformation, Ehlers fusion and High Pass Filter Resolution Merge. Four types of quantitative spectral analyses and visual detection were conducted to evaluate these algorithms.Main results: The Brovey transformation was the most useful algorithm to detect damage points, although it had an issue with the preservation of spectral characteristics.Research highlights: The detection rate of damage points was improved in 50% by applying the Brovey algorithm to a 10 m panchromatic image and 62.5 m multispectral image.Key words: ambrosia beetle; oak wilt; pan-sharpening; satellite imagery; visual detection.

  9. Australia's Uranium and thorium resources and their global significance

    International Nuclear Information System (INIS)

    Full text: Full text: Australia's world-leading uranium endowment appears to result from the emplacement of uranium enriched felsic igneous rocks in three major periods during the geological evolution of the continent. Australia has over 27% of the world's total reasonably assured uranium resources (RAR) recoverable at < US$80/kgU (which approximates recent uranium spot prices). Olympic Dam is the largest known uranium deposit, containing approximately 19% of global RAR (and over 40% of global inferred resources) recoverable at < US$80/kg U; the uranium is present at low concentrations and the viability of its recovery is underpinned by co-production of copper and gold. Most of Australia's other identified resources are within Ranger, Jabiluka, Koongarra, Kintyre and Yeelirrie, the last four of which are not currently accessible for mining. In 2004, Australia's three operating uranium mines - Ranger, Olympic Dam, and Beverley -produced 22% of global production. Canada was the only country to produce more uranium (29%) and Kazakhstan (9%) ranked third. Considerably increased uranium production has been recently foreshadowed from Australia (through developing a large open pit at Olympic Dam), Canada (mainly through opening of the Cigar Lake mine), and Kazakhstan (developing several new in situ leach mines). These increases should go a long way towards satisfying demand from about 2010. Olympic Dam has sufficient resources to sustain such increased production over many decades. Thorium is expected to be used in some future generations of nuclear reactors. Australia also has major (but incompletely quantified) resources of this commodity, mainly in heavy mineral sands deposits and associated with alkaline igneous rocks. It is inevitable that the international community will be looking increasingly to Australia to sustain its vital role in providing fuels for future nuclear power generation, given its world-leading identified resources, considerable potential for new

  10. Uranium industry annual 1993

    International Nuclear Information System (INIS)

    Uranium production in the United States has declined dramatically from a peak of 43.7 million pounds U3O8 (16.8 thousand metric tons uranium (U)) in 1980 to 3.1 million pounds U3O8 (1.2 thousand metric tons U) in 1993. This decline is attributed to the world uranium market experiencing oversupply and intense competition. Large inventories of uranium accumulated when optimistic forecasts for growth in nuclear power generation were not realized. The other factor which is affecting U.S. uranium production is that some other countries, notably Australia and Canada, possess higher quality uranium reserves that can be mined at lower costs than those of the United States. Realizing its competitive advantage, Canada was the world's largest producer in 1993 with an output of 23.9 million pounds U3O8 (9.2 thousand metric tons U). The U.S. uranium industry, responding to over a decade of declining market prices, has downsized and adopted less costly and more efficient production methods. The main result has been a suspension of production from conventional mines and mills. Since mid-1992, only nonconventional production facilities, chiefly in situ leach (ISL) mining and byproduct recovery, have operated in the United States. In contrast, nonconventional sources provided only 13 percent of the uranium produced in 1980. ISL mining has developed into the most cost efficient and environmentally acceptable method for producing uranium in the United States. The process, also known as solution mining, differs from conventional mining in that solutions are used to recover uranium from the ground without excavating the ore and generating associated solid waste. This article describes the current ISL Yang technology and its regulatory approval process, and provides an analysis of the factors favoring ISL mining over conventional methods in a declining uranium market

  11. Uranium industry annual 1993

    Energy Technology Data Exchange (ETDEWEB)

    1994-09-01

    Uranium production in the United States has declined dramatically from a peak of 43.7 million pounds U{sub 3}O{sub 8} (16.8 thousand metric tons uranium (U)) in 1980 to 3.1 million pounds U{sub 3}O{sub 8} (1.2 thousand metric tons U) in 1993. This decline is attributed to the world uranium market experiencing oversupply and intense competition. Large inventories of uranium accumulated when optimistic forecasts for growth in nuclear power generation were not realized. The other factor which is affecting U.S. uranium production is that some other countries, notably Australia and Canada, possess higher quality uranium reserves that can be mined at lower costs than those of the United States. Realizing its competitive advantage, Canada was the world`s largest producer in 1993 with an output of 23.9 million pounds U{sub 3}O{sub 8} (9.2 thousand metric tons U). The U.S. uranium industry, responding to over a decade of declining market prices, has downsized and adopted less costly and more efficient production methods. The main result has been a suspension of production from conventional mines and mills. Since mid-1992, only nonconventional production facilities, chiefly in situ leach (ISL) mining and byproduct recovery, have operated in the United States. In contrast, nonconventional sources provided only 13 percent of the uranium produced in 1980. ISL mining has developed into the most cost efficient and environmentally acceptable method for producing uranium in the United States. The process, also known as solution mining, differs from conventional mining in that solutions are used to recover uranium from the ground without excavating the ore and generating associated solid waste. This article describes the current ISL Yang technology and its regulatory approval process, and provides an analysis of the factors favoring ISL mining over conventional methods in a declining uranium market.

  12. Longevity of Lake Superior lake trout

    Science.gov (United States)

    Schram, Stephen T.; Fabrizio, Mary C.

    1998-01-01

    The age structure of mature lake trout Salvelinus namaycush from the Wisconsin waters of Lake Superior increased following a population recovery that has taken place since the 1960s. As the population aged, it became apparent that scales were unreliable aging structures. Beginning in 1986, we examined both scale and sagittal otolith ages from tagged fish with a known period at liberty. We found large discrepancies in scale and sagittal otolith ages of mature fish, such that scale ages were biased low. We estimated lake trout living up to 42 years, which is greater than previously reported from Lake Superior. Investigators studying lake trout population dynamics in the Great Lakes should be aware that lake trout can live longer than previously thought.

  13. Uranium from phosphate ores

    International Nuclear Information System (INIS)

    Phosphate rock, the major raw material for phosphate fertilizers, contains uranium that can be recovered when the rock is processed. This makes it possible to produce uranium in a country that has no uranium ore deposits. The author briefly describes the way that phosphate fertilizers are made, how uranium is recovered in the phosphate industry, and how to detect uranium recovery operations in a phosphate plant. Uranium recovery from the wet-process phosphoric acid involves three unit operations: (1) pretreatment to prepare the acid; (2) solvent extraction to concentrate the uranium; (3) post treatment to insure that the acid returning to the acid plant will not be harmful downstream. There are 3 extractants that are capable of extracting uranium from phosphoric acid. The pyro or OPPA process uses a pyrophosphoric acid that is prepared on site by reacting an organic alcohol (usually capryl alcohol) with phosphorous pentoxide. The DEPA-TOPO process uses a mixture of di(2-ethylhexyl)phosphoric acid (DEPA) and trioctyl phosphine oxide (TOPO). The components can be bought separately or as a mixture. The OPAP process uses octylphenyl acid phosphate, a commercially available mixture of mono- and dioctylphenyl phosphoric acids. All three extractants are dissolved in kerosene-type diluents for process use

  14. Uranium and Thorium

    Science.gov (United States)

    Finch, Warren I.

    1978-01-01

    The results of President Carter's policy on non-proliferation of nuclear weapons are expected to slow the growth rate in energy consumption, put the development of the breeder reactor in question, halt plans to reprocess and recycle uranium and plutonium, and expand facilities to supply enriched uranium. (Author/MA)

  15. Depleted uranium in Japan

    International Nuclear Information System (INIS)

    In Japan, depleted uranium ammunition is regarded as nuclear weapons and meets with fierce opposition. The fact that US Marines mistakenly fired bullets containing depleted uranium on an island off Okinawa during training exercises in December 1995 and January 1996, also contributes. The overall situation in this area in Japan is outlined. (P.A.)

  16. Uranium Measurements and Attributes

    International Nuclear Information System (INIS)

    It may be necessary to find the means to determine unclassified attributes of uranium in nuclear weapons or their components for future transparency initiatives. We briefly describe the desired characteristics of attribute measurement systems for transparency. The determination of uranium attributes; in particular, by passive gamma-ray detection is a formidable challenge

  17. Australia and uranium

    International Nuclear Information System (INIS)

    A brief justification of the Australian Government's decision to mine and export Australian Uranium is presented along with a description of the Alligator River Region in the Northern Territory where the major mines are to be located. Aboriginal interests and welfare in the region, the proposed Kakadu National Park and the economic benefits resulting from uranium development are also briefly covered. (J.R.)

  18. Rheinbraun's Australian uranium business

    International Nuclear Information System (INIS)

    The leaflet argues against the mining activities of the Rheinische Braunkohlenwerke AG in Germany and especially against uranium mining in Australia. The ethno-ecological impact on flora and fauna, aborigines and miners are pointed out. Uranium mining and lignite mining are compared. (HSCH)

  19. World uranium production outlook

    International Nuclear Information System (INIS)

    An outlook on the uranium trade (concentrate and hexafluoride) between the Western world and the the former Comecon countries. The flow from East to West is increased. Up to 1998 existing lower-cost reserves appear to supply enough uranium. Later, the supply gap will require greater output from development of known reserves at costs higher than $30/lb. 4 figs., 1 ref

  20. Uranium: biokinetics and toxicity

    International Nuclear Information System (INIS)

    This report was achieved as a part of a collaboration with the Fuel Cycle Direction. Its aim was to give the state of the art about: the behaviour of uranium in the human organism (biokinetics) after ingestion, its toxicity (mainly renal) and the current regulation about its incorporation. Both in the upstream and in the downstream of the fuel cycle, uranium remains, quantitatively, the first element in the cycle which is, at the present time, temporarily disposed or recycled. Such a considerable quantity of uranium sets the problem of its risk on the health. In the long term, the biosphere may be affected and consequently the public may ingest water or food contaminated with uranium. In this way, radiological and chemical toxicity risk may be activated. This report emphasizes: the necessity of confirming some experimental and epidemiological biokinetic data used or not in the ICRP models. Unsolved questions remain about the gastrointestinal absorption according to chemical form (valency state, mixtures...), mass and individual variations (age, disease) further a chronic ingestion of uranium. It is well established that uranium is mainly deposited in the skeleton and the kidney. But the skeleton kinetics following a chronic ingestion and especially in some diseases has to be more elucidated; the necessity of taking into account uranium at first as a chemical toxic, essentially in the kidney and determining the threshold of functional lesion. In this way, it is important to look for some specific markers; the problem of not considering chemical toxicity of uranium in the texts regulating its incorporation

  1. Coupled Uranium-Series and (U-Th)/He Zircon Geochronology of the Emmons Lake Volcanic Center (ELVC): Dating the Record of Voluminous Tephra Production in Quaternary Eastern-Beringia.

    Science.gov (United States)

    Burgess, S. D.; Vazquez, J. A.; Grove, M. J.; Coble, M. A.; Hourigan, J. K.; Waythomas, C. F.; Coombs, M. L.; Wallace, K.

    2015-12-01

    Tephrochronology is an invaluable tool used to date, link, and reconstruct paleo-environments, climates, and landscapes. Single tephra layers represent isochronous markers across broad regions, thus accurate and precise temporal constraints on the timing of eruption are critical to their utility. If a U-bearing accessory phase such as zircon is present, U/Pb, U-series, and (U-Th)/He geochronometers may be selectively applied. Application of multiple geochronometers to the same sample corroborates accuracy, can potentially resolve mineral crystallization and volcano eruption dates, and can define an eruption age from inherited crystals, assuming complete thermal resetting of the (U-Th)/He system upon crystal incorporation into magma prior to eruption. The Emmons Lake Volcanic Center is one of the largest Quaternary volcanic systems in the Aleutian volcanic arc, and is characterized by at least two major caldera-forming eruptions. C1 has been dated by 40Ar/39Ar at ~238 ka, and was originally proposed as the source for the Old Crow tephra, the largest and most widespread Quaternary tephra in eastern Beringia, and a critical time horizon for reconstruction of Pleistocene paleo-environment and climate. C2 produced the widespread Dawson tephra, and has been dated indirectly by radiocarbon at ~27 ka. We present in-situ grain-surface ion microprobe (SHRIMP-RG) 238U-230Th and/or U/Pb data on a suite of autocrysitc zircon grains from a C1 sample, the Old Crow, and from the Dawson. On these same zircon crystals, we utilize a noble gas sector mass spectrometer to make sensitive, low blank, single crystal 4He measurements. With these datasets, we investigate the temporal and potential genetic relationship between C1 and Old Crow, and place absolute radiogenic time constraints on the C2 eruption. Coupled 238U-230Th and sector field (U-Th)/He application shows significant promise for generating accurate, precise dates for Quaternary tephra bearing a U-rich accessory mineral phase.

  2. EPR of uranium ions

    International Nuclear Information System (INIS)

    A review of the electron paramagnetic resonance data on the uranium ions is given. After a general account of the electronic structure of the uranium free atoms and ions, the influence of the external fields (magnetic field, crystal fields) is discussed. The main information obtained from EPR studies on the uranium ions in crystals are emphasized: identification of the valence and of the ground electronic state, determination of the structure of the centers, crystal field effects, role of the intermediate coupling and of the J-mixing, role of the covalency, determination of the nuclear spin, maqnetic dipole moment and electric quadrupole moment of the odd isotopes of uranium. These data emphasize the fact that the actinide group has its own identity and this is accutely manifested at the beginning of the 5fsup(n) series encompassed by the uranium ions. (authors)

  3. Foreign uranium supply

    International Nuclear Information System (INIS)

    Known foreign uranium resources are concentrated in a few countries. The resources of many countries are largely unassessed, but the known uranium countries appear to have the best potential for future expansion. Availability of supply from known resources will depend on resolution of national policies regarding uranium production, ownership and export, and actions of the mining industry. Foreign uranium demand projections have decreased markedly in the last few years, and currently planned and attainable production should be adequate through the 1980's. Longer term resources and supply outlook are still a major concern to both those planning electric supply systems based on converter reactors and those considering reprocessing and recycle of uranium and plutonium and development of breeder reactors. Work continues to clarify long-term supply in several countries and internationally, but more effort, and time, will be needed to clarify these issues

  4. Management of depleted uranium

    International Nuclear Information System (INIS)

    Large stocks of depleted uranium have arisen as a result of enrichment operations, especially in the United States and the Russian Federation. Countries with depleted uranium stocks are interested in assessing strategies for the use and management of depleted uranium. The choice of strategy depends on several factors, including government and business policy, alternative uses available, the economic value of the material, regulatory aspects and disposal options, and international market developments in the nuclear fuel cycle. This report presents the results of a depleted uranium study conducted by an expert group organised jointly by the OECD Nuclear Energy Agency and the International Atomic Energy Agency. It contains information on current inventories of depleted uranium, potential future arisings, long term management alternatives, peaceful use options and country programmes. In addition, it explores ideas for international collaboration and identifies key issues for governments and policy makers to consider. (authors)

  5. Method of recovering uranium

    International Nuclear Information System (INIS)

    Uranium is recovered from a carbonate leach solution containing a dissolved uranium salt and a monovalent ion. The pH of the leach solution is adjusted to about 5 to about 7.5, and preferably to about 6 to about 7. Phosphate ion is then added to typical in-situ leach solutions in an amount from about 10 to about 30 mole % in excess of the amount needed to stoichiometrically react with the uranium in said solution. This results in the precipitation of a compound made up of the monovalent ion, uranium, and the phosphate ion, which is insoluble in the solution. The precipitate is then separated from the solution preferably by means of a centrifuge or a vortex clarifier. It can then be dissolved in acid, and the uranium extracted into an organic solvent such as DEHPA-TOPA in kerosene

  6. Jabiluka uranium project

    International Nuclear Information System (INIS)

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

  7. Responding to non-technical challenges in the uranium mining industry

    International Nuclear Information System (INIS)

    The modern uranium mining industry in Saskatchewan has been working with northerners, governments, and educational institutions for nearly 20 years to bring about one of the highest levels of northern and aboriginal participation in an industrial sector in Canada. It has accomplished this in the face of challenges - those arising from the demographics of the north, continuously rising expectations, and the at times difficult demands from evolving aboriginal political institutions. Every second apprenticeship vacancy at Key Lake is to be awarded to an employee of aboriginal ancestry. Saskatchewan dominates uranium mining because of the high grade of its deposits. Even though Key Lake, Rabbit Lake and Cluff Lake are coming near the end of their lives, they will be replaced by: McArthur River (with average grade 15% U3O8), Cigar Lake (9%), McClean Lake (3.5), Midwest (4.5). Without doubt, the grade and size of these new deposits will contribute to the competitiveness of the Saskatchewan uranium mining industry; but so too will the workforce

  8. Migration of uranium

    International Nuclear Information System (INIS)

    Uranium migration is treated as a process leading to mobilization and concentration of uranium in ore deposits. During the formation of global zonation, uranium migration contributed to the enrichment of this radioactive metal in the Earth's crust. The process of upper mantle and crust fractionation and differentiation is the first cycle of the mobilization process which led to uranium enrichment in rocks in some areas of the upper Earth's crust that could be considered as the primordial uranium provinces. Uranium migration is related to the structural history of sial Earth's crust and sial magmatism. During orogeny conditions could be created for development of progressive metamorphism and for magma generation. The latter is the best process for uranium mobilization. The effectiveness of this process depends on the composition of the primordial rocks and the intensity of the process. The importance of the magmatism for uranium mobilization is due to the magmatic differentiation. Selectively mobilized felsitic parts of the rocks migrate and form felsitic magmatic portions, which mobilize uranium. Solutions are the best uranium mobilization agents. Their generation starts with water separation from local permeable reservoirs and finishes with water dissociation from minerals during their dehydration. Such solutions could be endogenous or exogenous, depending on the igneous or sedimentary rocks which have been deformed. Some of the solutions can have mixed origin, if deformed magmatic rocks contain exogenous water in pores and cracks and endogenous water in minerals. The mobilizing ability of the solutions depends on their energy, which could derive from their chemical compositions and from physical conditions of the geological environment. The movement of the mineralized solutions can be due to steam pressure and the pressure difference between the starting and the final point of the juvenile solutions, gravity for meteoric waters, convection in geoconvection cells

  9. 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

  10. Bathymetry of Lake Erie and Lake Saint Clair

    Data.gov (United States)

    National Oceanic and Atmospheric Administration, Department of Commerce — Bathymetry of Lake Erie and Lake Saint Clair has been compiled as a component of a NOAA project to rescue Great Lakes lake floor geological and geophysical data and...

  11. Investigations in hydrogeochemical samples for uranium exploration

    International Nuclear Information System (INIS)

    The primary mandate of Atomic Minerals Directorate for Exploration and Research (AMD) is to explore and establish the uranium and other atomic mineral resources required for the country's nuclear power programme. During the geochemical exploration, a large number of ground, surface, spring, stream and lake water samples are collected and analysed for various parameters. These include physical parameters such as temperature, pH, Eh, electrical conductivity etc., and concentrations of uranium and multi-ions at mg/L to ng/L using state-of-the-art instrumental analytical techniques. Hydrogeochemical analysis is considered to be a cost effective and rapid exploration tool for getting sub-surface information leading to finding of concealed uranium deposits. Water samples from a bore well, dug well, stream, spring which is in dynamic equilibrium with the rocks are collected in a white, thick walled, non-transparent, non-recycled and air-tight container, stored and analysed within eight hours if possible to avoid change in Eh-pH conditions and precipitation-dissolution of trace elements

  12. Reconnaissance for uranium and thorium in Alaska, 1954

    Science.gov (United States)

    Matzko, John J.; Bates, Robert G.

    1957-01-01

    During 1954 reconnaissance investigations to locate minable deposits of uranium and thorium in Alaska were unsuccessful. Areas examined, from which prospectors had submitted radioactive samples, include Cap Yakataga, Kodiak Island, and Shirley Lake. Unconcentrated gravels from the beach at Cape Yakataga average about 0.001 percent equivalent uranium. Uranothorianite has been identified by X-ray diffraction data and is the principal source of radioactivity in the Cape Yakataga beach sands studied; but the zircon, monazite, and uranothorite are also radioactive. The black, opaque uranothorianite generally occurs as minute euhedral cubs, the majority of which will pass through a 100-mesh screen. The bedrock source of the radioactive samples from Kodiak Island was not found; the maximum radioactivity of samples from the Shirley Lake area was equivalent to about 0.02 percent uranium. Radiometric traverses of the 460-foot level of the Garnet shaft of the Nixon Fork mine in the Nixon Fork mining district indicated a maximum of 0.15 mr/hr. In the Hot Springs district, drill hole concentrates of gravels examined contained a maximum of 0.03 percent equivalent uranium. A radioactivity anomaly noted during the Survey's airborne reconnaissance of portions of the Territory during 1954 is located in the Fairhaven district. A ground check disclosed that the radioactivity was due to accessory minerals in the granitic rock.

  13. Uranium rich granite and uranium productive granite in south China

    International Nuclear Information System (INIS)

    The paper briefly introduces the differences between uranium rich granite and uranium productive granite in the 5 provinces of South China, and discusses their main characteristics in 4 aspects, the uranium productive granite is highly developed in fracture, very strong in alteration, often occurred as two-mica granite and regularly developed with intermediate-basic and acid dikes. The above characteristics distinguish the uranium productive granite from the uranium rich granite. (authors)

  14. The Fakili (Turkey) uranium deposit and its formation

    International Nuclear Information System (INIS)

    The Fakili deposit is situated in the Aegean region, in the west of Turkey. The rocks in the vicinity of the deposit consist principally of the metamorphic series of the Menderes Massif and Neogene sediments. The metamorphic series, comprising mainly augen-gneisses, constitutes the basement rock of the Neogene sedimentary basin. The Neogene sediments can be divided into three categories: the detrital series lowest down, above that the marl series and then lacustrine limestone. The detrital series consists of clays, silts, sands, gravels and conglomerates. The lower parts are distinctly fluviatile, with intersecting stratification. Higher up within the series, starting at the lower fluviatile sediments, are the lacustrine sediments, with horizontal beds providing for lateral continuity. The marl series consists of alternating clay and tuffite layers with silts, sandstone and marls; it is inhomogeneous and irregular, with many changes of facies. At the same stratigraphic level, however, there are two distinct facies: the first is generally representative of the series and contains marls; the second is the Fakili facies, distinguished from the first by a number of characteristics-variegated colouring, absence of marl, presence of secondary gypsum and sedimentary pyrites, and a generally higher level of radioactivity. The Fakili uranium deposit is located in this facies. The lacustrine limestones are the youngest sediments of the Neogene lake. The Fakili uranium deposit was created in two phases: syngenetic precipitation and epigenetic concentration. At the start of the sedimentation of the marl series, the lake water was rich in dissolved uranium. The Neogene detrital series became enriched in sulphate compounds near the base of the Fakili facies; the sulphate concentration is at a maximum above the contact with the Fakili facies and decreases as one moves upwards. This high sulphate concentration is the result of evaporation in this part of the lake. Evaporation

  15. Uranium deposits in Africa

    International Nuclear Information System (INIS)

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

  16. Uranium resource assessments

    International Nuclear Information System (INIS)

    The objective of this investigation is to examine what is generally known about uranium resources, what is subject to conjecture, how well do the explorers themselves understand the occurrence of uranium, and who are the various participants in the exploration process. From this we hope to reach a better understanding of the quality of uranium resource estimates as well as the nature of the exploration process. The underlying questions will remain unanswered. But given an inability to estimate precisely our uranium resources, how much do we really need to know. To answer this latter question, the various Department of Energy needs for uranium resource estimates are examined. This allows consideration of whether or not given the absence of more complete long-term supply data and the associated problems of uranium deliverability for the electric utility industry, we are now threatened with nuclear power plants eventually standing idle due to an unanticipated lack of fuel for their reactors. Obviously this is of some consequence to the government and energy consuming public. The report is organized into four parts. Section I evaluates the uranium resource data base and the various methodologies of resource assessment. Part II describes the manner in which a private company goes about exploring for uranium and the nature of its internal need for resource information. Part III examines the structure of the industry for the purpose of determining the character of the industry with respect to resource development. Part IV arrives at conclusions about the emerging pattern of industrial behavior with respect to uranium supply and the implications this has for coping with national energy issues

  17. Cost study on waste management at three model Canadian uranium mines

    International Nuclear Information System (INIS)

    A waste management cost study was initiated to determine the capital and operating costs of three different uranium waste management systems which incorporate current technologies being used in Canadian uranium mining operations. Cost estimates were to be done to a thirty percent level of accuracy and were to include all waste management related costs of a uranium ore processing facility. Each model is based on an annual uranium production of 1,923,000 kg U (5,000,000 lbs U3O8) with a total operating life of 20 years for the facility. The three models, A, B, and C, are based on three different uranium ore grades, 0.10 percent U3O8, 0.475 percent U3O8 and 1.5 percent U3O8 respectively. Yellowcake production is assumed to start in January 1984. Model A is based on a conceptual 7,180 tonne per day uranium ore processing facility and waste management system typical of uranium operations in the Elliot Lake area of northern Ontario with an established infrastructure. Model B is a 1.512 tonne per day operation based on a remote uranium operation typical of the Athabasca Basin properties in northern Saskatchewan. Model C is a 466 tonne per day operation processing a high-grade uranium ore containing arsenic and heavy metal concentrations typical of some northern Saskatchewan deposits

  18. The uranium in the environment

    International Nuclear Information System (INIS)

    The uranium is a natural element omnipresent in the environment, with a complex chemistry more and more understood. Many studies are always today devoted to this element to better improve the uranium behavior in the environment. To illustrate this knowledge and for the public information the CEA published this paper. It gathers in four chapters: historical aspects and properties of the uranium, the uranium in the environment and the impacts, the metrology of the uranium and its migration. (A.L.B.)

  19. Production of uranium peroxide

    International Nuclear Information System (INIS)

    The invention provides a process for recovering uranium values as uranium peroxide from an aqueous uranyl solution containing dissolved vanadium and sodium impurities. It consists of treating the uranyl solution with hydrogen peroxide in an amount equal to at least 0.5 part H2O2 per part of vanadium (V2O5) in solution in excess of the stoichiometric (1.26 parts/part U3O8) amount required to form the uranium peroxide. The hydrogen peroxide treatment is carried out in three phases. (auth)

  20. Uranium assay in milk

    International Nuclear Information System (INIS)

    Powder milk, and fresh milk from buffalo and dairy cattle in North India, were irradiated with a thermal neutron flux of 1017 n cm-2. Neutron dose was calculated by counting tracks on an etched K-43 glass dosimeter. The uranium concentration in milk is low when compared with concentrations in other food stuffs, and its radiotoxicity to humans is considerably lower than chemical toxicity. If a human consumes 1 litre of milk/day, containing .1 μg uranium/litre, for 60 yrs, total intake of uranium would be only 2 mg compared to a maximum permissible intake of 40mg. (U.K.)

  1. Depleted uranium management alternatives

    International Nuclear Information System (INIS)

    This report evaluates two management alternatives for Department of Energy depleted uranium: continued storage as uranium hexafluoride, and conversion to uranium metal and fabrication to shielding for spent nuclear fuel containers. The results will be used to compare the costs with other alternatives, such as disposal. Cost estimates for the continued storage alternative are based on a life-cycle of 27 years through the year 2020. Cost estimates for the recycle alternative are based on existing conversion process costs and Capital costs for fabricating the containers. Additionally, the recycle alternative accounts for costs associated with intermediate product resale and secondary waste disposal for materials generated during the conversion process

  2. Uranium mining and milling

    International Nuclear Information System (INIS)

    In this report uranium mining and milling are reviewed. The fuel cycle, different types of uranium geological deposits, blending of ores, open cast and underground mining, the mining cost and radiation protection in mines are treated in the first part of this report. In the second part, the milling of uranium ores is treated, including process technology, acid and alkaline leaching, process design for physical and chemical treatment of the ores, and the cost. Each chapter is clarified by added figures, diagrams, tables, and flowsheets. (HK)

  3. Geology of the Honeymoon Uranium Project

    International Nuclear Information System (INIS)

    The Honeymoon Uranium Project comprises the Honeymoon Deposit, Goulds Dam Deposit and Yarramba Prospect in the Southern Lake Frome region, South Australia. Both the Yarramba Prospect and Honeymoon Deposit (which includes Honeymoon and East Kalkaroo orebodies) are located in the Yarramba Palaeovalley. The Goulds Dam Deposit is about 75 km north west of Honeymoon, in the Billeroo Palaeovalley. Exploration for sediment-hosted uranium began in the area in the late 1960s, culminating in the discovery of Honeymoon and Goulds Dam in the early 1970s. In 1982, a 25 L/s demonstration plant was built at Honeymoon to confirm suitability for in situ leaching. The project was put on hold in 1983 due to changes in government policy. Southern Cross Resources Australia Pty Ltd acquired the project in mid 1997. Roll-front deposits form from a migrating geochemical cell, an advancing reduction-oxidation interface between oxygenated uranium-bearing groundwater and its reduced aquifer host. The source of metal is uranium-anomalous granites, which were eroded from surrounding ranges. The weathered granites and resultant sediments are stripped of uranium by oxidised groundwaters, to form solutions carrying uranyl carbonate complexes. The solutions percolate down-slope through permeable sand zones until contacting a reduced environment where uranium precipitates. Uranium mineralisation occurs interstitially between and as thin coatings on sand grains, usually in the form of uraninite or coffinite. The palaeovalleys (previously termed palaeochannels) are incised into underlying Cambrian/Precambrian basement rocks and filled with semi-consolidated, largely un-cemented, Tertiary sediments of the Eyre Formation. The late Palaeocene to middle Eocene Eyre Formation is the basal unit of the Tertiary succession in the Callabonna Sub-basin of the Lake Eyre Basin. Further to the north, the Lake Eyre Basin overlies the Jurassic-Cretaceous Eromanga Basin, which comprises much of the Great Australian

  4. ZHOUZHUANG, A "TOWN IN LAKES"

    Institute of Scientific and Technical Information of China (English)

    2005-01-01

    @@ Zhouzhuang Town islocated in thesouthwestern part ofKunshan City,neighboring WujiangCity, Suzhou City andQingpu District ofShanghai City, andsurrounded by ChengLake, Changbai Lake,Dianshan Lake, BaiyiLake and South Lake, asknown as a "town in lakes".

  5. Radioactive material in the West Lake Landfill: Summary report

    Energy Technology Data Exchange (ETDEWEB)

    None

    1988-06-01

    The West Lake Landfill is located near the city of St. Louis in Bridgeton, St. Louis County, Missouri. The site has been used since 1962 for disposing of municipal refuse, industrial solid and liquid wastes, and construction demolition debris. This report summarizes the circumstances of the radioactive material in the West Lake Landfill. The radioactive material resulted from the processing of uranium ores and the subsequent by the AEC of processing residues. Primary emphasis is on the radiological environmental aspects as they relate to potential disposition of the material. It is concluded that remedial action is called for. 8 refs., 2 figs., 1 tab.

  6. Uranium in granites

    International Nuclear Information System (INIS)

    Recent research activities of the Canadian Uranium in Granites Study are presented in 18 papers and 3 abstracts. 'Granites' is used as a generic term for granitoids, granitic rocks, and plutonic rocks

  7. Uranium purchases report 1993

    International Nuclear Information System (INIS)

    Data reported by domestic nuclear utility companies in their responses to the 1991 through 1993 ''Uranium Industry Annual Survey,'' Form EIA-858, Schedule B,'' Uranium Marketing Activities,'' are provided in response to the requirements in the Energy Policy Act 1992. Appendix A contains an explanation of Form EIA-858 survey methodologies with emphasis on the processing of Schedule B data. Additional information published in this report not included in Uranium Purchases Report 1992, includes a new data table. Presented in Table 1 are US utility purchases of uranium and enrichment services by origin country. Also, this report contains additional purchase information covering average price and contract duration. Table 2 is an update of Table 1 and Table 3 is an update of Table 2 from the previous year's report. The report contains a glossary of terms

  8. Uranium hydrothermal deposits

    Czech Academy of Sciences Publication Activity Database

    René, Miloš

    New York : Nova Science Publishers, 2012 - (Vasiliev, A.; Sidorov, M.), s. 211-244 ISBN 978-1-62081-207-5 Institutional research plan: CEZ:AV0Z30460519 Keywords : uranium * hydrothermal deposits * uraninite Subject RIV: DB - Geology ; Mineralogy

  9. Uranium Location Database

    Data.gov (United States)

    U.S. Environmental Protection Agency — A GIS compiled locational database in Microsoft Access of ~15,000 mines with uranium occurrence or production, primarily in the western United States. The metadata...

  10. 300 AREA URANIUM CONTAMINATION

    International Nuclear Information System (INIS)

    (smbullet) Uranium fuel production (smbullet) Test reactor and separations experiments (smbullet) Animal and radiobiology experiments conducted at the. 331 Laboratory Complex (smbullet) .Deactivation, decontamination, decommissioning,. and demolition of 300 Area facilities

  11. Uranium in alkaline rocks

    Energy Technology Data Exchange (ETDEWEB)

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

    1978-04-01

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

  12. The uranium market prospects

    International Nuclear Information System (INIS)

    A historical analysis of the uranium market points out the cyclical nature of the market and suggests that the spot price, exploration levels, and mill capacity utilization rate are dependent on economic factors. An examination of the current uranium market suggests that the effects of the forecasted surplus supply, the diminishing returns in exploration and the long lead times and high costs of development may mean that future production levels are uncertain. The general prospects for the uranium industry are also uncertain because of barriers to trade, environmental regulations and public opinion. The paper concludes that by the use of long term contracts, appropriate inventory policy and greater discussion between producers and consumers the prospects for the uranium market can be made more certain and further imbalances in demand and supply can be avoided. (author)

  13. Selective separation of uranium

    International Nuclear Information System (INIS)

    A process for the selective separation of uranium from elements accompanying it in a uranium-containing ore is claimed. It comprises preparing a uranium-containing solution; adding hydrochloric acid in an amount sufficient to form complex anions of the type (UO2Clsub(n))sup(2-n) where n is 3 or 4, or sulfuric acid in an amount sufficient to form complex anions of the type UO2(SO4)sub(m)sup(2-2m) where m is 2 or 3; adding a cationic surface active agent which forms a difficultly soluble precipitate with the complex anion; subjecting the solution to a gas flotation step to produce a foam fraction containing the pecipitate and a liquid fraction; separating the two fractions; and recovering uranium from the foam fraction

  14. Uranium determination in zirconium

    International Nuclear Information System (INIS)

    The method used for the spectrometric uranium determination with 2-(2-thiolase)-5-diethylaminophenol was modified for its application in the zirconium samples analysis with an uranium content of the 0.1% order. The samples, previously dissolved in nitric acid, were submitted to a separative stage of liquid-liquid extraction, with a trioctylphosphine (TOPO) oxide diluted in cyclohexane. A sodium fluoride aqueous solution was necessary to be aggregated in the spectrometric determination so as to complex the zirconium vestiges, which could be present, originated by the Zr/U high relation of the initial sample. Under the established working conditions, different spectrometric assays, dyes absorption spectra and its uranium complex, complex stability, PH influence determination of the dyes-uranium relation, calculation of the complex's apparent formation constant and its molar absorption, were performed. (Author)

  15. Uranium in alkaline rocks

    International Nuclear Information System (INIS)

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

  16. Uranium hexafluoride purification

    International Nuclear Information System (INIS)

    Uranium hexafluoride might contain a large amount of impurities after manufacturing or handling. Three usual methods of purification of uranium hexafluoride were presented: selective sorption, sublimation, and distillation. Since uranium hexafluoride usually is contaminated with hydrogen fluoride, a theoretical study of the phase equilibrium properties was performed for the binary system UF6-HF. A large deviation from the ideal solution behaviour was observed. A purification unity based on a constant reflux batch distillation process was developed. A procedure was established in order to design the re boiler, condenser and packed columns for the UF6-HF mixture separation. A bench scale facility for fractional distillation of uranium hexafluoride was described. Basic operations for that facility and results extracted from several batches were discussed. (author)

  17. Uranium conversion and enrichment

    International Nuclear Information System (INIS)

    A description is given of the Atomic Energy Corporation's uranium conversion and enrichment plants at Valinda ba, including a brief discussion of problems encountered and plans for future developments. (author)

  18. Workshop on radon and radon daughters in urban communities associated with uranium mining and processing

    International Nuclear Information System (INIS)

    This meeting of Atomic Energy Control Board staff, representatives of other government departments, and consultants was called to exchange information on steps taken to lower radiation levels in houses in communities such as Elliot Lake, Uranium City, and Port Hope. Discussions covered the sources of radon and radon daughters in these houses, radon measurement techniques, and remedial methods that worked or were not successful

  19. Ranger uranium environmental enquiry

    International Nuclear Information System (INIS)

    The submission is divided into three sections. Section A considers the international implications of the development of uranium resources including economic and resource aspects and environmental and social aspects. Section B outlines the government's position on export controls over uranium and its effect on the introduction of nuclear power in Australia. Section C describes the licensing and regulatory functions that would be needed to monitor the environmental and health aspects of the Ranger project. (R.L.)

  20. Uranium purchases report 1994

    International Nuclear Information System (INIS)

    US utilities are required to report to the Secretary of Energy annually the country of origin and the seller of any uranium or enriched uranium purchased or imported into the US, as well as the country of origin and seller of any enrichment services purchased by the utility. This report compiles these data and also contains a glossary of terms and additional purchase information covering average price and contract duration. 3 tabs

  1. Recovery of uranium values

    International Nuclear Information System (INIS)

    A process is provided for the recovery of uranium from an organic extractant phase containing an amine. The extractant phase is contacted in a number of mixing stages with an acidic aqueous stripping phase containing sulphate ions, and the phases are passed together through a series of mixing stages while maintaining a dispersion of droplets of one phase in the other. Uranium is precipitated from the final stage by raising the pH. An apparatus having several mixing chambers is described

  2. Uranium project. Geochemistry prospection

    International Nuclear Information System (INIS)

    Geochemistry studies the distribution of the chemicals elements in the terrestrial crust and its ways to migrate. The terminology used in this report is the following one: 1) Principles of the prospection geochemistry 2) Stages of the prospection geochemistry 3)utility of the prospection geochemistry 4) geochemistry of uranium 5) procedures used within the framework of uranium project 6) Average available 7) Selection of the zones of prospection geochemistry 8) Stages of the prospection, Sample preparation and analisis 9) Presentation of the results

  3. Uranium tailings bibliography

    International Nuclear Information System (INIS)

    A bibliography containing 1,212 references is presented with its focus on the general problem of reducing human exposure to the radionuclides contained in the tailings from the milling of uranium ore. The references are divided into seven broad categories: uranium tailings pile (problems and perspectives), standards and philosophy, etiology of radiation effects, internal dosimetry and metabolism, environmental transport, background sources of tailings radionuclides, and large-area decontamination

  4. Separation of uranium isotopes

    International Nuclear Information System (INIS)

    This invention provides a method for separating uranium isotopes comprising the steps of selectively irradiating a photochemically-reactive uranyl source material at a wavelength selective to a desired isotope of uranium at an effective temperature for isotope spectral line splitting below about 77 K, further irradiating the source material within the fluorescent lifetime of the selectively irradiated source material to selectively photochemically reduce the selectively excited isotopic species, and chemically separating the reduced isotope species from the remaining uranyl salt compound

  5. Automated uranium assays

    International Nuclear Information System (INIS)

    Precise, timely inventories of enriched uranium stocks are vital to help prevent the loss, theft, or diversion of this material for illicit use. A wet-chemistry analyzer has been developed at LLL to assist in these inventories by performing automated analyses of uranium samples from different stages in the nuclear fuel cycle. These assays offer improved accuracy, reduced costs, significant savings in manpower, and lower radiation exposure for personnel compared with present techniques

  6. Uranium determination in water

    International Nuclear Information System (INIS)

    In our laboratory, a procedure has been assessed to determine uranium content of water in normal situations. The method proposed without sample pre-treatment, is simple and rapid. Uranium mass is measured by fluorimetry. For calculation of detection limit (Ld) and quantification level (Lq) we used blank samples and the results were analyzed for different statistical test. The calculation of total propagated uncertainty and sources contribution on real samples are presented. (author)

  7. Uranium leads political stakes

    International Nuclear Information System (INIS)

    Until the announcement by the federal Environment Minister Peter Garrett that the government would permit uranium mining at Beverly Four Mile, South Australia, there had been little news flow from the sector over the past year. Uranium was the first to turn down, even before the United States sub-prime mortgage crisis began to cause shock waves through the global economy, a report by BGF Equities analyst Warwick Grigor shows.

  8. National Lakes Assessment Data

    Data.gov (United States)

    U.S. Environmental Protection Agency — The National Lakes Assessment (NLA) is a first-ever statistically-valid survey of the biological condition of lakes and reservoirs throughout the U.S. The U.S....

  9. DNR 24K Lakes

    Data.gov (United States)

    Minnesota Department of Natural Resources — Medium scale lake polygons derived from the National Wetlands Inventory (NWI) polygons and MnDOT Basemap lake delineations. Integrated with the DNR 24K Streams...

  10. Aktivitäten der Bundesländer zur Verhinderung der Ausbreitung der Beifuß- Ambrosie (Ambrosia artemisiifolia in Deutschland

    Directory of Open Access Journals (Sweden)

    Nawrath, Stefan

    2014-07-01

    Full Text Available In the seventh year after the publication of the Federal Programme of Action aiming at the prevention of the spread of ragweed, an assessment based on 14 criteria is made to which extent the tasks of the programme were implemented by the states. It was validated whether a monitoring system could be established. Since common ragweed is not homogeneously distributed in Germany, the requirement to implement measures against the species differs between the federal states. Thus, the population size of common ragweed was estimated for each of the 16 German federal states first and after that the states were classified depending on the size of the species’ occurrences. Requirements for action were formulated. At present, the largest ragweed stands occur in the federal state Brandenburg, followed by Bavaria, Baden-Württemberg, Rhineland–Palatinate and Hesse. The most extensive measures were conducted in Bavaria, Baden-Württemberg, Berlin and Brandenburg. The investigation shows that the scope of the measures does not correlate with the extent of Ambrosia occurrences in the states in every case. Since ragweed pollen coming from extensive plant populations can be spread by wind, and since ragweed spread will not stop at administrative borders, it should be the goal to achieve a nationwide equal as possible high level of activities. If the measures against common ragweed will not be intensified, further spread of the species is likely. The historic opportunity, to prevent the spread of Ambrosia in an early phase of the propagation process with even relatively little effort and thus protection of the health of the population, then would be wasted.

  11. Production of sized particles of uranium oxides and uranium oxyfluorides

    International Nuclear Information System (INIS)

    A process for converting uranium hexafluoride to uranium dioxide of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen to form a mixture of uranium oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed. (Patent Office Record)

  12. Production of uranium peroxide

    International Nuclear Information System (INIS)

    The process of recovering uranium values as uranium peroxide from an aqueous uranyl solution containing dissolved vanadium and sodium impurities, characterized by treating the uranyl solution with hydrogen peroxide in an amount sufficient to have an excess of at least 0.5 parts H2O2 per part vanadium (V2O5) above the stoichio-metric amount required to form the uranium peroxide, the hydrogen peroxide treatment being carried out in three sequential phases consisting of: 1) a precipitation phase in which the hydrogen peroxide is added to the uranyl solution to precipitate the uranium peroxide and the pH of the reaction media maintained in the range of 3.0 to 7.0 for a period of 5 to 180 60 minutes after the hydrogen peroxide addition; 2) a digestion phase in which the pH of the reaction medium is maintained in the range of 3.0 to 7.0 for a period of 5 to 180 minutes and 3) a final phase in which the pH of the reaction media is maintained in the range of 4.0 to 7.0 for a period of 1 to 60 minutes during which time the uranium peroxide is separated from the reaction solution containing the dissolved vanadium and sodium impurities, the excess hydrogen peroxide aforesaid being maintained until the uranium peroxide is separated from the reaction mixture

  13. Kvanefjeld uranium project

    International Nuclear Information System (INIS)

    The purpose of the Kvanefjeld uranium project is to evaluate the possibility of a uranium production from the deposit at Narssaq, South Greenland. The project comprises investigations in the fields of geology, mining, process chemistry and technology, economy and environment protection. The predominant uraniferous rock is a nepheline syenite called lujavrite in which the main uranium mineral is steenstrupine. The deposit can be mined in an open pit. Calculations have shown a resource of 56 million tonnes of ore with an average grade of 365 ppm corresponding to 20,400 tonnes of uranium. The uranium is extracted by a sodium carbonate solution at 260degC in an autoclave. A pilot plant has been established including ball mill, continuous pipe autoclave and a belt filter for separation of leach liquor and residue. The uranium is finally precipitated as UO2 by reduction in an autoclave at 260degC. With the existing ore sample, recoveries of more than 80% have been obtained. The carbonate leaching causes a low solubility of most contaminants in the tailings. A draft project has been prepared for an industrial plant in Greenland. The total investments have been calculated at 3 x 109 Dkr. Electrical energy is assumed to be supplied by a hydropower plant at Johan Dahl Land. The mine and mill are expected to employ 500-600 persons. (author)

  14. Uranium entrapment in wetlands: A case study at the Boston Peak fen, Colorado, U.S.A

    International Nuclear Information System (INIS)

    The Boston Peak fen, a 5-hectare, uranium-enriched wetland located northwest of Rocky Mountain National Park in northern Colorado, has been the subject of intensive study by U.S. Geological Survey scientists through surface mapping, drilling, and sampling of an extensive network of 59 auger and core holes. Uranium concentrations increased dramatically in the organic-rich gyttja (50-150 ppm) compared to the lower lakebeds (4-70 ppm). The uranium in the gyttja is stratabound, and variations in uranium content between sediment layers could be caused by differences in supply of dissolved uranium to the lake and differences in sediment redox conditions. Uranium concentrations in the gyttja drop before the transition to peat, except in lake sediment near spring or seep sources, despite the constant or increasing organic matter content of the gyttja. Dissolved uranium delivered by spring water was now locally fixed by peat adjacent to the spring pools, resulting in uranium concentrations of as much as 4,000 ppm (dry weight) whereas peat distant from spring pools may have only a few ppm of uranium. Water chemistry and uranium in peat are discussed. Studies of this wetland confirm the well-documented observation that wetlands serve as natural filters for uranium and many other potentially hazardous trace elements that may otherwise enter downstream surface waters. Inadvertent or deliberate destruction of metalbearing wetlands may diminish water quality and remove the potential for continued filtering activity. The processes affecting uranium transport, sorption, and ultimate fixation in the peat may have relevance for understanding uranium-organic associations in ore deposits in the major sandstone uranium districts of the San Juan Basin and elsewhere. Stratabound uranium in the gyttja may serve as an analogue of much older uranium- and organic-matter-rich systems such as the massive low-grade lacustrine uranium deposits of late Tertiary age in some western Arizona basins

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

    International Nuclear Information System (INIS)

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

  16. Technologies for lake restoration

    OpenAIRE

    Helmut KLAPPER

    2003-01-01

    Lakes are suffering from different stress factors and need to be restored using different approaches. The eutrophication remains as the main water quality management problem for inland waters: both lakes and reservoirs. The way to curb the degradation is to stop the nutrient sources and to accelerate the restoration with help of in-lake technologies. Especially lakes with a long retention time need (eco-) technological help to decrease the nutrient content in the free water. The microbial and...

  17. Uranium distribution in Baikal sediments using SSNTD method for paleoclimate reconstruction

    CERN Document Server

    Zhmodik, S M; Nemirovskaya, N A; Zhatnuev, N S

    1999-01-01

    First data on local distribution of uranium in the core of Lake Baikal floor sediments (Academician ridge, VER-95-2, St 3 BC, 53 deg. 113'12'N/108 deg. 25'01'E) are presented in this paper. They have been obtained using (n,f)-radiography. Various forms of U-occurrence in floor sediments are shown, i.e. evenly disseminated, associated with clayey and diatomaceous components; micro- and macroinclusions of uranium bearing minerals - microlocations with uranium content 10-50 times higher than U-concentrations associated with clayey and diatomaceous components. Relative and absolute U-concentration can be determined for every mineral. Signs of various order periodicity of U-distribution in the core of Lake Baikal floor sediments have been found. Using (n,f)-radiography method of the study of Baikal floor sediment permits gathering of new information that can be used at paleoclimate reconstruction.

  18. Uranium distribution in Baikal sediments using SSNTD method for paleoclimate reconstruction

    International Nuclear Information System (INIS)

    First data on local distribution of uranium in the core of Lake Baikal floor sediments (Academician ridge, VER-95-2, St 3 BC, 53 deg. 113'12'N/108 deg. 25'01'E) are presented in this paper. They have been obtained using (n,f)-radiography. Various forms of U-occurrence in floor sediments are shown, i.e. evenly disseminated, associated with clayey and diatomaceous components; micro- and macroinclusions of uranium bearing minerals - microlocations with uranium content 10-50 times higher than U-concentrations associated with clayey and diatomaceous components. Relative and absolute U-concentration can be determined for every mineral. Signs of various order periodicity of U-distribution in the core of Lake Baikal floor sediments have been found. Using (n,f)-radiography method of the study of Baikal floor sediment permits gathering of new information that can be used at paleoclimate reconstruction

  19. Distribution and behavior of radionuclides and stable elements in Lake Obuchi

    International Nuclear Information System (INIS)

    This investigation focused on the relationship between the uranium concentration and organic matter in the lake water and the bottom sediment of Lake Obuchi, Rokkasho Village, Aomori. Concentrations of 238U and organic matter were measured at various points in the lake, and compiled to obtain the distributions and variation characteristics. Concentrations of dissolved organic carbon (DOC) in the lake water were approximately 1.8 mg l-1. In contrast, these concentrations were low (0.5 mg l-1) in Futamata River. The relationship between the concentrations of 238U and DOC in the lake water did not have a significant correlation. However, there was a close relationship (r=-0.87) between the ratios of 238U/salinity and DOC in the bottom layer water. Moreover, a relationship between concentration of uranium and total organic carbon in core sediment had a significant correlation (r=0.80). These results suggest that uranium was reduced from a stable form +6 valence from to an unstable +4 valence form and was removed from the lake water, after the consumption of O2 accompanied by the decomposition of the organic matter in sediment caused chemical reduction in the bottom layer. (author)

  20. Anticorrosion protection of uranium

    International Nuclear Information System (INIS)

    Uranium in atmospheric conditions is non-stable. Sloughing products are being generated on its surface during storage or use. These corrosion products make many difficulties because of necessity to provide personnel safety. Besides, uranium corrosion may cause damage in parts. The first works devoted to uranium corrosion were performed in the framework of the USA Manhattan Project in the early forties of last century. Various methods of uranium protection were investigated, among them the galvanic one was the most studied. Later on the galvanic technology was patented. The works on this problem remains urgent up to the present time. In Russia, many methods of uranium corrosion protection, mainly against atmospheric corrosion, were tried on. In particular, such methods as diffusion zinc and paint coating were investigated. In the first case, a complex intermetallic U-Zn compound was formed but its protection was not reliable enough, this protection system was inconvenient and uncertain and that is why an additional paint coating was necessary. In the case of paint coatings another problem appeared. It was necessary to find such a coating where gas-permeability would prevail over water-permeability. Otherwise significant uranium corrosion occurs. This circumstance together with low mechanical resistance of paint coatings does not allow to use paint coating for long-term protection of uranium. Currently, there are following methods of uranium protection: ion-plasma, galvanic and thermo-vacuum annealing. These are described in this paper. In the end the issue of corrosion protection in reactor core zones is addressed. Here the greatest difficulties are caused when enriched uranium heated up to 500 deg. C needs anticorrosion protection. In this case various metal coatings are not reliable because of brittle inter-metallide formation. The reliable protection may be provided only up to the temperature plus 400 - 500 deg. C with the help of galvanic copper coating since

  1. Study of uranium plating measurement

    International Nuclear Information System (INIS)

    In neutron physics experiments, the measurement for plate-thickness of uranium can directly affect uncertainties of experiment results. To measure the plate-thickness of transform target (enriched uranium plating and depleted uranium plating), the back to back ionization chamber, small solid angle device and Au-Si surface barrier semi-conductor, were used in the experiment study. Also, the uncertainties in the experiment were analyzed. Because the inhomo-geneous of uranium lay of plate can quantitively affect the result, the homogeneity of uranium lay is checked, the experiment result reflects the homogeneity of uranium lay is good. (authors)

  2. Uranium. Suppl. Vol. A3

    International Nuclear Information System (INIS)

    This supplement volume 'Uranium' deals with uranium technology, from winning to the fabrication of nuclear fuels containing uranium and their use in various reactor types. Alternative reprocessing methods for ores are described e.g. winning from phosphate ores and sea water, production of uranium compounds (oxide, carbide, nitride etc., hexafluoride for isotope separation) and of uranium-metals and -alloys as well as the utilization of metallic and other compounds of uranium - single or embedded - as nuclear fuels and their fabrication. The behaviour of the nuclear fuel and the way it modifies during reactor operation are described in an extra volume (supplement volume A4). (RB)

  3. Uranium currently selling very badly

    International Nuclear Information System (INIS)

    Surplus offers and declining revenue have caused exploratory and uranium mining activities to slow down. The same applies to research activities on the profitability of leading uranium-carrying rock or recovering uranium from seawater, which have been cut off worldwide. Prices for natural uranium are plunging deep as a consequence of surplus offers. There is little hope among uranium producers that the situation might change in the near future. For the projected Wackersdorf fuel reprocessing facility, this means that one argument of supporters, - lack of uranium for fuel fabrication - has lost its basis. (DG)

  4. Determination of low concentration of uranium in uranium amalgam

    International Nuclear Information System (INIS)

    Because of the strong interference in the determination of low concentrations of uranium in uranium amalgam by spectrophotometry, a new and rapid method has been developed for the removal of the interference of mercury(II) ion in the range of low uranium concentration by reducing Hg(II) to Hg in the sample dissolved in nitric acid with ascorbic acid. The separated uranium in the solution is determined by spectrophotometry in the concentration range of 0.25 approximately 5 mg/g uranium amalgam. The average error is about 2%. Very low concentrations of uranium (approximately 0.25 mg/g) in the uranium amalgam can be determined directly by fluorometric method. No interference effect has been observed at the mercury to uranium ratio up to 105; the average error is about 10%. (author)

  5. Australia's uranium export potential

    International Nuclear Information System (INIS)

    During the period 1954-71 in Australia approximately 9000 MT of U3O8 was produced from five separate localities. Of this, 7000 MT was exported to the United Kingdom and United States and the balance stockpiled by the Australian Atomic Energy Commission (AAEC). Australia's uranium ore reserves occur in eight deposits in three states and the Northern Territory. However, 83% of Australia's reserves are contained in four deposits in lower Proterozoic rocks in the East Alligator River region of the Northern Territory. The AAEC has calculated Australia's recoverable uranium reserves by eliminating estimated losses during the mining and milling of the ores. AAEC has estimated reasonably assured resources of 289,000 MT of uranium at a recovery cost of less than US$80 per kilogram uranium. The companies have collectively announced a larger ore reserve than the Australian Atomic Energy Commission. This difference is a result of the companies adopting different ore reserve categories. On August 25, 1977, the federal government announced that Australia would develop its uranium resources subject to stringent environmental controls, recognition of Aboriginal Land Rights, and international safeguards. Australian uranium production should gradually increase from 1981 onward, growing to 10,000 to 15,000 MT by 1985-86. Further increases in capacity may emerge during the second half of the 1980s when expansion plans are implemented. Exploration for uranium has not been intensive due to delays in developing the existing deposits. It is likely that present reserves can be substantially upgraded if more exploration is carried out. 6 figures, 3 tables

  6. Uranium in Todilto Limestone (Jurassic) of New Mexico: example of a Sabkha-Like Deposit

    International Nuclear Information System (INIS)

    The Todilto Limestone was deposited in or near a large lake that became restricted at times and evaporated to dryness. The formation has a lower limestone member and an upper gypsum member. The limestone member has been divided informally into three zones: the lower platy zone, a middle crinkly zone, and an upper recrystallized zone. The platy zone is interpreted to have been deposited below wave base under anoxic conditions. The crinkly zone has thin stromatolitic laminations that may form algal domes. The upper recrystallized zone appears in part to be a collapsed breccia caused by the removal of interbedded gypsum. Uranium ore is restricted primarily to the crinkly and recrystallized zones. These two zones may have been formed in a sabkhalike environment. A sabkha origin has been proposed for some stratiform copper deposits. The same conditions that cause copper to precipitate would also cause uranium to precipitate. Ground water bearing U+6 could also be drawn upward by evaporative pumping through the decaying algal-mat zone where the uranium would be reduced to U+4 and precipitated. Carbonate materials lithify early, destroying permeability, so that uranium emplacement must occur before lithification. Radioisotope dates on uraninite in the Todilto Limestone indicate ore emplacement shortly after deposition. Uranium-bearing ground water moved basinward in the underlying Entrada Sandstone and was drawn upward through the stromatolitic zones along the southwest margins of Lake Todilto where uranium was precipitated

  7. Uranium production capability: North America, Australia, Asia and Africa

    International Nuclear Information System (INIS)

    With the apparent need for additional primary uranium supply, the paper discusses necessary preconditions for mine construction and then reviews the supply potential in North America, Australia, Africa and Asia. Canadian uranium supply will increase from 12 000 t U to over 16 000 t U by 2011 with the commencement of production at the Cigar Lake mine and the eventual mining of the Midwest Lake deposit. Canadian production levels will then begin a slow and steady decline from 2014 onwards as existing economic deposits become exhausted. Production in the United States of America will continue to be dominated by in situ leech mines but certain conventional mines will provide some additional production. Total US production may reach 4000 t U by 2010. Future Australian production levels are clouded in uncertainty. Restrictive Government policies are once again having an impact on uranium prices. A potential tripling of production at Olympic Dam, however, will have a dramatic impact on uranium supplies if a decision to expand production is indeed made. Depending upon market forces, Government and corporate decisions, uranium production in Australia could vary from as little as 4500 t U to as much as 22 000 t U by 2020. After 30 years of production, Phase 1 mining at the Roessing mine in Namibia is nearly complete and the mine is now faced with a series of difficult decisions in order to remain in operation beyond 2009. Steady output from existing mines in Niger is expected for at least a further ten years, and additional mining opportunities have been identified. Other potential African production sources are also discussed. Mongolia has the potential to become a new modest sized producer, depending upon the outcome of further studies. Production levels in India and China are expected to increase modestly in order to help satisfy domestic needs. (author)

  8. Influence of uranium hydride oxidation on uranium metal behaviour

    International Nuclear Information System (INIS)

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

  9. Interaction between geosphere and biosphere in lake sediments

    International Nuclear Information System (INIS)

    One main issue in the safety assessment of nuclear repositories, in which processes influence the distribution pattern of radionuclide elements in the biopshere when released radioactivity is carried with groundwater that penetrates through the bottom sediment of a lake. To be able to evaluate the transport of elements such as thorium, uranium, and rare earth elements (REE), sampling of lake sediment cores at different Swedish sites with different degrees of groundwater leakage was performed. Different lake sediment fractions have been identified. One fraction is related to aluminosilicates (clay and sand contents), while the other major fraction contains organic material. Enrichment of uranium is observed in areas of groundwater seepage, and U-contents is correlated to the levels of organic matter. Besides a higher mobility and enrichment of uranium compared to thorium is observed. Chondrite normalised REE sediment contents have been found higher in the most reducing sediments. The weathering and deposition processes are discussed in connection with the degree of mobility of elements. Elements as titanium, zirconium and hafnium are nearly insoluble in aqueous solutions. The immobility of these elements have been confirmed by this study. Hafnium is selected to study the differentiation of the sediment fraction originating from refractory and other physically weathered minerals. (au) (33 refs., 45 figs., 30 tbls.)

  10. Uranium hexafluoride handling

    International Nuclear Information System (INIS)

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF6 from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride

  11. Uranium deposits of Brazil

    International Nuclear Information System (INIS)

    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) U3O8 (100 thousand pounds). Brazil's state-owned uranium production and processing company, Uranio do Brasil, announced it 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 U3O8 (600 million pounds U3O8) in reserves

  12. Microbial reduction of uranium

    International Nuclear Information System (INIS)

    Reduction of the soluble, oxidized form of uranium, U(VI), to insoluble U(IV) is an important mechanism for the immobilization of uranium in aquatic sediments and for the formation of some uranium ores. U(VI) reduction had generally been regarded as an abiologial reaction in which sulphide, molecular hydrogen or organic compounds function as the reductant. Microbial involvement in U(VI) reduction has been considered to be limited to indirect effects, such as microbial metabolism providing the reduced compounds for abiological U(VI) reduction and microbial cell walls providing a surface to stimulate abiological U(VI) reduction. We report here, however, that dissimilatory Fe(III)-reducing microorganisms can obtain energy for growth by electron transport to U(VI). This novel form of microbial metabolism can be much faster than commonly cited abiological mechanisms for U(VI) reduction. Not only do these findings expand the known potential terminal electron acceptors for microbial energy transduction, they offer a likely explanation for the deposition of uranium in aquatic sediments and aquifers, and suggest a method for biological remediation of environments contaminated with uranium. (author)

  13. Uranium hexafluoride handling. Proceedings

    Energy Technology Data Exchange (ETDEWEB)

    1991-12-31

    The United States Department of Energy, Oak Ridge Field Office, and Martin Marietta Energy Systems, Inc., are co-sponsoring this Second International Conference on Uranium Hexafluoride Handling. The conference is offered as a forum for the exchange of information and concepts regarding the technical and regulatory issues and the safety aspects which relate to the handling of uranium hexafluoride. Through the papers presented here, we attempt not only to share technological advances and lessons learned, but also to demonstrate that we are concerned about the health and safety of our workers and the public, and are good stewards of the environment in which we all work and live. These proceedings are a compilation of the work of many experts in that phase of world-wide industry which comprises the nuclear fuel cycle. Their experience spans the entire range over which uranium hexafluoride is involved in the fuel cycle, from the production of UF{sub 6} from the naturally-occurring oxide to its re-conversion to oxide for reactor fuels. The papers furnish insights into the chemical, physical, and nuclear properties of uranium hexafluoride as they influence its transport, storage, and the design and operation of plant-scale facilities for production, processing, and conversion to oxide. The papers demonstrate, in an industry often cited for its excellent safety record, continuing efforts to further improve safety in all areas of handling uranium hexafluoride. Selected papers were processed separately for inclusion in the Energy Science and Technology Database.

  14. Uranium tailings sampling manual

    International Nuclear Information System (INIS)

    The purpose of this manual is to describe the requisite sampling procedures for the application of uniform high-quality standards to detailed geotechnical, hydrogeological, geochemical and air quality measurements at Canadian uranium tailings disposal sites. The selection and implementation of applicable sampling procedures for such measurements at uranium tailings disposal sites are complicated by two primary factors. Firstly, the physical and chemical nature of uranium mine tailings and effluent is considerably different from natural soil materials and natural waters. Consequently, many conventional methods for the collection and analysis of natural soils and waters are not directly applicable to tailings. Secondly, there is a wide range in the physical and chemical nature of uranium tailings. The composition of the ore, the milling process, the nature of tailings depositon, and effluent treatment vary considerably and are highly site-specific. Therefore, the definition and implementation of sampling programs for uranium tailings disposal sites require considerable evaluation, and often innovation, to ensure that appropriate sampling and analysis methods are used which provide the flexibility to take into account site-specific considerations. The following chapters describe the objective and scope of a sampling program, preliminary data collection, and the procedures for sampling of tailings solids, surface water and seepage, tailings pore-water, and wind-blown dust and radon

  15. Uranium markets after the hangover

    Energy Technology Data Exchange (ETDEWEB)

    Douglas, H. (Hugh Douglas and Co. Ltd., San Francisco, CA (USA))

    1982-07-01

    A report is given on the current depressed state of the world's uranium markets and on the prospects for recovery. The impact on the uranium industry of low prices and reduced demand are outlined.

  16. Uranium analysis. Fluorine ionometric determination

    International Nuclear Information System (INIS)

    Fluorine determination in uranium, applicable for fluorine content between 10 to 2000 ppm, by dissolution in nitric acid, uranium (VI) citric complex formation, ionometry, potential is compared with a calibration curve

  17. Some Lake Level Control Alternatives for the Great Salt Lake

    OpenAIRE

    Allen, Marvin E.; Christensen, Ronald K.; Riley, J. Paul

    1983-01-01

    Fluctuations of the level of the Great Salt Lake cause large changes in both surface area and shoreline. Developments adjacent to the lake have been damaged by both high and low lake levels; and unless measures are implemented to regulate lake level fluctuations or otherwise to protect these developments, damages will continue. Various possible managment alternatives for mitigating potential damages from lake leve...

  18. The geochemical immobilization of uranium in a spent fuel repository in the Canadian Shield: Evidence from natural analogue investigations

    International Nuclear Information System (INIS)

    Natural analogue studies of uranium ore deposits provide valuable information on the geochemical conditions that control the mobilization of uranium and associated radionuclides in groundwaters. At Cigar Lake in northern Saskatchewan, the Pocos de Caldas site in Brazil, and at Palmottu in Finland, groundwaters are sufficiently reducing to prevent significant oxidation of U+4 to the more soluble U+6 oxidation state. Despite being one of the richest uranium deposits in the world, uranium concentrations in the groundwaters around the Cigar Lake ore are less than 5 x 10-8 M. Even under oxiding conditions uranium may not necessarily be highly mobilized by groundwaters. Studies of the relatively shallow uranium ore deposits in the Alligator Rivers region of Australia have shown that uranium transport by groundwater can be limited because of uranium sorption onto secondary iron oxides within the aquifer. However, studies at 'negative analgoue' sites indicate that where the host rocks contain low concentrations of reductants such as iron sulphides, strongly reducing conditions are not established and high concentrations of dissolved uranium can result, even in areas where uranium ore deposits are not known to occur. The release rate of radionuclides from a spent fuel repository will be strongly dependent on the redox conditions that are established following resaturation of the repository. Groundwater at depths of 500 m in a granitic pluton may not be sufficiently reducing to prevent oxidative dissolution of uranium or oxidation of associated radionuclides such as 99Tc. Accordingly other shield rocks richer in reductants, such as greenstone belts, should be considered as potential host rocks for a repository or the repository should be constructed at depths closer to 1000 m in granitic rock where more reducing conditions are likely to prevail. Alternatively, addition of reductants to the waste containers may be feasible as a means of maintaining reducing conditions around

  19. Geology and uranium favorability of the Sonora Pass region, Alpine and Tuolumne Counties, California

    International Nuclear Information System (INIS)

    Uranium mineralization at the Juniper Mine is restricted to host rocks of the Relief Peak Formation and is most common in coarse-grained lithic sandstone, conglomerate, and lithic wacke. The richest beds contain as much as 0.5% U3O8. Uranium is present as coffinite, uraninite, and unidentified minerals. Thorium/uranium ratios are generally low and erratic. Equivalent uranium determinations are low in comparison with chemical uranium values, indicating that uranium mineralization of the Juniper Mine is geologically young. Core drilling at 16 localities shows that widely separated exposures of the Relief Peak Formation have very similar lithology, geochemistry, and stratigraphy. Some sections are similar to the Juniper Mine section. Core from the bottom of drill hole SP-1 contains 83 ppM uranium, the greatest known concentration outside the mine area. Significant uranium deposits may be concealed beneath the thick Tertiary volcanic cover of the region. The quartz latitic Eureka Valley Tuff is fairly widespread in east-central California and western Nevada. It contains 12 to 14 ppM uranium and stratigraphically overlies the Relief Peak Formation. It is permeable and contains abundant alkali metals and volcanic glass. Because of its petrology, geochemistry, and position, this formation is the most likely source for uranium mineralization of the Sonora Pass region. It should be examined as a potential source rock in other areas with special regard to its relationship to carbonaceous sedimentary formations. The uraniferous granite pegmatitite dike that crops out in the Niagara Creek area appears too small to be a significant source rock. The most favorable rocks in the Sonora Pass region occur near the Juniper Mine and west of it, in the Dardanelles, the Whittakers Dardanelles, and the area of the Big Meadow Quadrangle. Potential uranium host rocks crop out in areas along the crest of the Sierra Nevada from Lake Tahoe to Yosemite

  20. The Toxicity of Depleted Uranium

    OpenAIRE

    Wayne Briner

    2010-01-01

    Depleted uranium (DU) is an emerging environmental pollutant that is introduced into the environment primarily by military activity. While depleted uranium is less radioactive than natural uranium, it still retains all the chemical toxicity associated with the original element. In large doses the kidney is the target organ for the acute chemical toxicity of this metal, producing potentially lethal tubular necrosis. In contrast, chronic low dose exposure to depleted uranium may not produce a c...

  1. Uranium resources, production and demand

    International Nuclear Information System (INIS)

    Nuclear power-generating capacity will continue to expand, albeit at a slower pace than during the past fifteen years. This expansion must be matched by an adequately increasing supply of uranium. This report compares uranium supply and demand data in free market countries with the nuclear industry's natural uranium requirements up to the year 2000. It also reviews the status of uranium exploration, resources and production in 46 countries

  2. Radiation damage of metal uranium

    International Nuclear Information System (INIS)

    This report is concerned with the role of dispersion second phase in uranium and burnup rate. The role of dispersion phases in radiation stability of metal uranium was studies by three methods: variation of electric conductivity dependent on the neutron flux and temperature of pure uranium for different states of dispersion second phase; influence of dispersion phase on the radiation creep; transmission electron microscopy of fresh and irradiated uranium

  3. A new approach for designing, safe operation and decommissioning of high grade uranium mill facilities

    International Nuclear Information System (INIS)

    COGEMA Resources Inc.'s operation at McClean Lake will consist of milling and processing ores from the richest uranium deposits in the world. These deposits, located in the Athabasca basin of northern Saskatchewan, Canada, include those of Cigar Lake, McClean Lake and Midwest Projects. All the ores from these deposits will be processed at the McClean Lake JEB mill. The ore grades vary up to 30% uranium, and in some cases pure massive pitchblende is encountered. The McClean Lake JEB mill, is designed with an initial capacity of 6 million lb. U3O8 annually. Following approval of the Cigar Lake Project by both governments, the capacity of the mill will be expanded to 24 million lb. U3O8. Although the initial grade of ores to be processed at the JEB Mill (2% uranium to 4.75% uranium) are much less than those expected from Cigar Lake (up to 30% uranium), they are still high enough to warrant special radiation protection measures. The philosophical tenet for the mill design includes health, safety and environment protection for the short and long term. Thus, the design ensures a maintenance free solution after decommissioning to protect future generations and the land. To this end, the ore receiving facility for Cigar Lake and Midwest ores will be remotely operated to protect employees from gamma radiation. The leaching area of the mill is based on a two-floor concept with an elevated concrete slab of about 40 cm separating the upper and lower floors. The vessels also have concrete cells around them and access is strictly restricted to protect personnel. A dual ventilation system has been established in the mill with specific pressure gradients. With the single pass ventilation, a positive pressure will be maintained in the clean areas (control rooms) and a negative pressure will be kept in the potentially contaminated areas, from where the air will be exhausted to the atmosphere. Due to the presence of radiation and other industrial hazards, the mill has been zoned

  4. Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

    Energy Technology Data Exchange (ETDEWEB)

    Kraemer, Lisa D., E-mail: lisakraemer@trentu.ca [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada); Evans, Douglas [Trent University, 1600 West Bank Drive, Peterborough, ON, K9J 7B8 (Canada)

    2012-11-15

    Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2-3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios ({sup 15}N/{sup 14}N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

  5. Uranium bioaccumulation in a freshwater ecosystem: Impact of feeding ecology

    International Nuclear Information System (INIS)

    Uranium bioaccumulation in a lake that had been historically affected by a U mine and (2) to use a combined approach of gut content examination and stable nitrogen and carbon isotope analysis to determine if U bioaccumulation in fish was linked to foodweb ecology. We collected three species of fish: smallmouth bass (Micropterus dolomieu), yellow perch (Perca flavescens) and bluegill (Lepomis macrochirus), in addition to several invertebrate species including freshwater bivalves (family: Sphaeriidae), dragonfly nymphs (order: Odonata), snails (class: Gastropoda) and zooplankton (family: Daphniidae). Results showed significant U bioaccumulation in the lake impacted by historical mining activities. Uranium accumulation was 2–3 orders of magnitude higher in invertebrates than in the fish species. Within fish, U was measured in operculum (bone), liver and muscle tissue and accumulation followed the order: operculum > liver > muscle. There was a negative relationship between stable nitrogen ratios (15N/14N) and U bioaccumulation, suggesting U biodilution in the foodweb. Uranium bioaccumulation in all three tissues (bone, liver, muscle) varied among fish species in a consistent manner and followed the order: bluegill > yellow perch > smallmouth bass. Collectively, gut content and stable isotope analysis suggests that invertebrate-consuming fish species (i.e. bluegill) have the highest U levels, while fish species that were mainly piscivores (i.e. smallmouth bass) have the lowest U levels. Our study highlights the importance of understanding the feeding ecology of fish when trying to predict U accumulation.

  6. Uranium extraction technology

    International Nuclear Information System (INIS)

    In 1983 the Nuclear Energy Agency of the Organisation for Economic Co-operation and Development (OECD/NEA) and the IAEA jointly published a book on Uranium Extraction Technology. A primary objective of this report was to document the significant technological developments that took place during the 1970s. The purpose of this present publication is to update and expand the original book. It includes background information about the principle of the unit operations used in uranium ore processing and summarizes the current state of the art. The publication also seeks to preserve the technology and the operating 'know-how' developed over the past ten years. This publication is one of a series of Technical Reports on uranium ore processing that have been prepared by the Division of Nuclear Fuel Cycle and Waste Management at the IAEA. A complete list of these reports is included as an addendum. Refs, figs and tabs

  7. Therapy of uranium contaminations

    International Nuclear Information System (INIS)

    Renal risks associated with the use of chelating agent as a treatment for acute uranium contamination were investigated. Rats were given a single intramuscular injection of uranyl nitrate solution. The percentage of renal uptake of uranyl nitrate as a function of the quantity injected was measured. Then the effect of a single DTPA intraperitoneal injection and the effect of a single bicarbonate injection on renal uptake of uranyl nitrate were studied. The preliminary results were as follows: constancy of renal uptake of uranyl nitrate (13 to 20% of the quantity injected); harmlessness of DTPA as a treatment for uranium contamination (DTPA does not increase uranium renal burden); inefficacy of bicarbonates on uranyl renal uptake

  8. The Kintyre uranium project

    Energy Technology Data Exchange (ETDEWEB)

    Larson, B. [Canning Resources Pty. Ltd., Perth, WA (Australia)

    1997-12-31

    The Kintyre Uranium Project is being developed by Canning Resources Pty Ltd, a subsidiary of Rio Tinto (formerly CRA). The work on the project includes the planning and management of a number of background environmental studies. The company has also commissioned studies by external consultants into process technologies, mining strategies and techniques for extracting the uranium ore from the waste rock. In addition, Canning Resources has made a detailed assessment of the worldwide market potential for Australian uranium in the late 1990s and into the 21st century. The most significant factor affecting the future of this project is the current product price. This price is insufficient to justify the necessary investment to bring this project into production. 8 figs.

  9. The Kintyre uranium project

    International Nuclear Information System (INIS)

    The Kintyre Uranium Project is being developed by Canning Resources Pty Ltd, a subsidiary of Rio Tinto (formerly CRA). The work on the project includes the planning and management of a number of background environmental studies. The company has also commissioned studies by external consultants into process technologies, mining strategies and techniques for extracting the uranium ore from the waste rock. In addition, Canning Resources has made a detailed assessment of the worldwide market potential for Australian uranium in the late 1990s and into the 21st century. The most significant factor affecting the future of this project is the current product price. This price is insufficient to justify the necessary investment to bring this project into production

  10. Early uranium politics

    International Nuclear Information System (INIS)

    An account is given of early uranium politics, including personal reminiscences. The discovery of and early work on uranium is sketched, leading to the price war over the sale of radium. Details are given of the situation as it developed from the discovery of fission and the outbreak of war, when large quantities of ore were secured for use in the United States atomic bomb project. Negotiations with the Belgians for Belgian Congo ores are described. The post-war period is covered, with a near monopoly for the US-UK-Canada purchasing agency changing to an open market for uranium. The attempts to get agreement on safeguards, to avoid proliferation of atomic weapons, and the particular situation of the French government, are also covered. (U.K.)

  11. Uranium exploration in Ecuador

    International Nuclear Information System (INIS)

    The 600-km segment of the Andean Cordillera in Ecuador includes zones that can be correlated, geologically, with uranium districts elsewhere in the Andes. It is believed that these essentially unexplored zones have the potential for economic uranium mineralization. Exploration activity to date has been limited, although it has involved both geochemical and radiometric techniques to evaluate geological concepts. Minor uranium occurrences (with chemical analyses up to 100 ppm) have been encountered, which provide further incentive to commence large-scale systematic exploration. It is recognized that a very large exploration budget and considerable technical expertise will be required to ensure exploration success. Consequently, participation by groups of proven capability from other countries will be sought for Ecuador's national exploration programme. (author)

  12. Uranium Enrichment, an overview

    International Nuclear Information System (INIS)

    This general presentation on uranium enrichment will be followed by lectures on more specific topics including descriptions of enrichment processes and assessments of the prevailing commercial and industrial situations. I shall therefore avoid as much as possible duplications with these other lectures, and rather dwell on: some theoretical aspects of enrichment in general, underlying the differences between statistical and selective processes, a review and comparison between enrichment processes, remarks of general order regarding applications, the proliferation potential of enrichment. It is noteworthy that enrichment: may occur twice in the LWR fuel cycle: first by enriching natural uranium, second by reenriching uranium recovered from reprocessing, must meet LWR requirements, and in particular higher assays required by high burn up fuel elements, bears on the structure of the entire front part of the fuel cycle, namely in the conversion/reconversion steps only involving UF6 for the moment. (author). tabs., figs., 4 refs

  13. Uranium extraction from seawater

    International Nuclear Information System (INIS)

    After an introduction to the physics and chemistry of the sea and an estimation of the chances for the absorption of uranium from rivers, the material-sepecific characteristics of the adsorber technology are decribed in detail. Then, the methods used for gaining uranium form seawater are described with special regard to the tidal and the so-called serial (sequency) method. Whether all methods described can be realised is an economic problem since very high quantitics of water are necessary because of the low contents of uranium. A positive energy balance (gained energy/lost energy) is not definitely ensured yet for the production methods used. The development measures to be taken to obtain a positive energy balance are briefly described, and the research programme of the UEBG is mentioned. (UA)

  14. Uranium - surplus or scarcity

    International Nuclear Information System (INIS)

    The new joint report of the OECD Nuclear Energy Agency and the International Atomic Energy Agency will help to remove some of the prevailing confusion about the world's actual and potential resources of uranium. The Agencies confirm that the danger of a worldwide uranium shortage has receded and that, over the new few years, there could actually develop an over-supply situation, with a consequent drop in prices. They emphasise, however, that this will be a temporary phenomenon and that inadequate uranium supplies may set limits, in the longer run, to the rapid build-up of nuclear power installations. The report is the latest in a series of similar studies which now normally appear at two-yearly intervals. (author)

  15. A review of CANMET's acid chloride leaching of uranium ores

    International Nuclear Information System (INIS)

    Conventional sulphuric acid leach processing of uranium ore is technically and economically viable but presents some environmental concerns because almost all of the radium and the sulphides, especially pyrite (an acid generating mineral), present in the ore report to the tailing disposal sites. In order to obtain leach tailings with a radium (226) content of 20-25 pCi/g solids and essentially free of pyrite, an alternative HCl leach process has been developed. Hydrochloric acid leaching of low-grade pyritic uranium ore (e.g. Elliot Lake U-ore) followed by flotation for pyrite removal from the final leach residue yielded tailings essentially free of pyrite and radionuclides, the radium level in the tailings being in the range of 25-30 pCi g-1 solids. Acid chloride leaching of Midwest Lake uranium ore, under various conditions (e.g., HCl, HCl-CaCl2-O2 pressure, HCL-FeCl3) provided high extraction of U, Ni, As and Ra and tailings with radium levels above 177 pCi g-1 solids. However HCl leaching of the radium preleached Midwest Lake uranium ore provided the best extraction of U(>99%), Ni(88%), As(90%) and Ra (98%) and the tailings with only 108 pCi g-1 solids radium. Of course, out of these 108 pCi/g solids, at least 66 pCi/g solids were tied up with the residual uranium (0.02%) in the tailings, and the remaining radium (42 pCi/g solids) present as sparingly soluble radium salt/salts (e.g., RaS04). The acid chloride leaching process for uranium ore has definite technological and environmental merits but presently compares unfavourably both in capital and operating costs with the conventional sulphuric acid leach process. However, the economics of the HCl leach process could become viable when the costs of removing the radium (226) and the sulphides (i.e., the acid generating minerals) from sulphuric acid leach tailings are taken into consideration

  16. Consumo de Uroleucon ambrosiae (Thomas, 1878 (Hemiptera: Aphididae por larvas de Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae em casa-de-vegetação Consumption of Uroleucon ambrosiae (Thomas, 1878 (Hemiptera: Aphididae BY Chrysoperla externa (Hagen, 1861 (Neuroptera: Chrysopidae larvae in greenhouse

    Directory of Open Access Journals (Sweden)

    Alexander M. Auad

    2003-06-01

    Full Text Available Com esta pesquisa objetivou-se verificar o consumo de Uroleucon ambrosiae em diferentes densidades, por larvas de Chrysoperla externa provenientes de diferentes regimes alimentares, em casa-de-vegetação. Ninfas de 3º e 4º ínstares do afídeo foram separadas nas densidades 30, 40 e 50, e colocadas nas plantas de alface (35 dias de idade, as quais, foram envolvidas por gaiola de armação de ferro de 27x27x26 cm cobertas com tecido “voil” e acoplada nos tubos de PVC do cultivo hidropônico. Quatro horas após, uma larva de C. externa, de diferentes ínstares e previamente alimentadas com U. ambrosiae ou ovos de Sitotroga cerealella (Olivier, 1819, foi liberada próximo à colônia de afídeos, sendo a gaiola fechada imediatamente; o mesmo procedimento foi adotado sem que a larva fosse confinada. Após quarenta e oito horas, realizou-se a contagem do número de afídeos consumidos em cada densidade de presa disponível. A eficiência do predador, confinado em gaiola, foi de 12,46%, 13,63% e 25,76% para larvas de 1º, 2º e 3º ínstares previamente alimentadas com ovos de S. cerealella; 9,59% e 17,63% para aquelas de 2º e 3º ínstares alimentadas anteriormente com ninfas de U. ambrosiae, respectivamente e de 18,62% para larvas de 3º ínstar previamente alimentadas com ovos do lepidóptero no 1º ínstar e ninfas dos afídeos no 2º instar; no entanto, para larvas não confinadas, não foram verificadas diferenças significativas na eficiência. Nas densidades de 40 e 50 afídeos, as porcentagens de predação (18,30 e 18,72, respectivamente foram significativamente superiores quando comparada à densidade 30 (11,79; para testes sem confinamento, não houve influência da densidade da presa na resposta do predador. Assim, o alimento fornecido às larvas de C. externa antes de serem liberadas em casa-de-vegetação, o confinamento das mesmas e a densidade de U. ambrosiae disponível influenciaram o potencial de consumo do predador

  17. Uranium immobilization and nuclear waste

    International Nuclear Information System (INIS)

    Considerable information useful in nuclear waste storage can be gained by studying the conditions of uranium ore deposit formation. Further information can be gained by comparing the chemistry of uranium to nuclear fission products and other radionuclides of concern to nuclear waste disposal. Redox state appears to be the most important variable in controlling uranium solubility, especially at near neutral pH, which is characteristic of most ground water. This is probably also true of neptunium, plutonium, and technetium. Further, redox conditions that immobilize uranium should immobilize these elements. The mechanisms that have produced uranium ore bodies in the Earth's crust are somewhat less clear. At the temperatures of hydrothermal uranium deposits, equilibrium models are probably adequate, aqueous uranium (VI) being reduced and precipitated by interaction with ferrous-iron-bearing oxides and silicates. In lower temperature roll-type uranium deposits, overall equilibrium may not have been achieved. The involvement of sulfate-reducing bacteria in ore-body formation has been postulated, but is uncertain. Reduced sulfur species do, however, appear to be involved in much of the low temperature uranium precipitation. Assessment of the possibility of uranium transport in natural ground water is complicated because the system is generally not in overall equilibrium. For this reason, Eh measurements are of limited value. If a ground water is to be capable of reducing uranium, it must contain ions capable of reducing uranium both thermodynamically and kinetically. At present, the best candidates are reduced sulfur species

  18. Uranium resources, demand and production

    International Nuclear Information System (INIS)

    Estimations of the demand and production of principal uranium resource categories are presented. The estimations based on data analysis made by a joint 'NEA/IAEA Working Party on Uranium Resources' and the corresponding results are published by the OECD (Organization for Economic Co-operation and Development) in the 'Uranium Resources, Production and Demand' Known as 'Red Book'. (M.C.K.)

  19. Uranium hazards stressed by Ham

    International Nuclear Information System (INIS)

    The Ham report, from the Ontario Royal Commission on the Health and Safety of Workers in Mines, is summarized. An unprecedented postwar uranium mining boom strained regulatory resources, causing a disproportionate number of uranium miners to succumb to silicosis. Ventilation, not job rotation, is the answer to radiation protection in uranium mining. (E.C.B.)

  20. Uranium. Resources, production and demand

    International Nuclear Information System (INIS)

    The events characterising the world uranium market in the last several years illustrate the persistent uncertainly faced by uranium producers and consumers worldwide. With world nuclear capacity expanding and uranium production satisfying only about 60 per cent of demand, uranium stockpiles continue to be depleted at a high rate. The uncertainty related to the remaining levels of world uranium stockpiles and to the amount of surplus defence material that will be entering the market makes it difficult to determine when a closer balance between uranium supply and demand will be reached. Information in this report provides insights into changes expected in uranium supply and demand until well into the next century. The 'Red Book', jointly prepared by the OECD Nuclear Energy Agency and the International Atomic Energy Agency, is the foremost reference on uranium. This world report is based on official information from 59 countries and includes compilations of statistics on resources, exploration, production and demand as of 1 January 1997. It provides substantial new information from all of the major uranium producing centres in Africa, Australia, Eastern Europe, North America and the New Independent States, including the first-ever official reports on uranium production in Estonia, Mongolia, the Russian Federation and Uzbekistan. It also contains an international expert analysis of industry statistics and worldwide projections of nuclear energy growth, uranium requirements and uranium supply

  1. Sandstone-type uranium deposits

    International Nuclear Information System (INIS)

    World-class sandstone-type uranium deposits are defined as epigenetic concentrations of uranium minerals occurring as uneven impregnations and minor massive replacements primarily in fluvial, lacustrine, and deltaic sandstone formations. The main purpose of this introductory paper is to define, classify, and introduce to the general geologic setting for sandstone-type uranium deposits

  2. The uranium International trade

    International Nuclear Information System (INIS)

    The aim of this thesis is the understanding of how the present dynamic of uranium International trade is developed, the variables which fall into, the factors that are affecting and conditioning it, in order to clarify which are going to be the outlook in the future of this important resource in front of the present ecological situation and the energetic panorama of XXI Century. For this purpose, as starting point, the uranium is considered as a strategic material which importance take root in its energetic potential as alternate energy source, and for this reason in Chapter I, the general problem of raw materials, its classification and present situation in the global market is presented. In Chapter II, by means of a historical review, is explain what uranium is, how it was discovered, and how since the end of the past Century and during the last three decades of present, uranium pass of practically unknown element, to the position of a strategic raw material, which by degrees, generate an International market, owing to its utilization as a basic resource in the generation of energy. Chapter III, introduce us in the roll played by uranium, since its warlike applications until its utilization in nuclear reactors for the generation of electricity. Also is explain the reason for this change in the perception at global level. Finally, in Chapter IV we enter upon specifically in the present conditions of the International market of this mineral throughout the trends of supply and demand, the main producers, users, price dynamics, and the correlation among these economical variables and other factors of political, social and ecological nature. All of these with the purpose to found out, if there exist, a meaning of the puzzle that seems to be the uranium International trade

  3. Lake retention of manufactured nanoparticles

    NARCIS (Netherlands)

    Koelmans, A.A.; Quik, J.T.K.; Velzeboer, I.

    2015-01-01

    For twenty-five world lakes and three engineered nanoparticles (ENP), lake retention was calculated using a uniformly mixed lake mass balance model. This follows similar approaches traditionally used in water quality management. Lakes were selected such that lake residence times, depths and areal hy

  4. Chemwes Uranium Plant

    International Nuclear Information System (INIS)

    The Chemwes Uranium Plant is located in an area which is underlain to a major extent by pinnacled dolomite. It was decided to adopt a replacement fill for support of light structures in preference to alternatives such as the installation of piles or 'bridging' between pinnacles. The 3 m thick soil 'raft' resulting from the fill replacement technique made it possible to support all but a very small number of foundations upon shallow spread footings or raft slabs. This article describes a replacement fill for support of light structures at the Chemwes Uranium Plant

  5. Uranium - Australia's decision

    International Nuclear Information System (INIS)

    Ministerial statements by the Prime Minister, Deputy Prime Minister, Acting Minister for Foreign Affairs, Minister for Aboriginal Affairs, Minister for Environmental, Housing and Community Development and the Minister for Health, concerning Australia's decision to mine and export uranium are presented. Background information setting out the factors which guided the Government in reaching its decision is included. Reference to the findings and recommendations of the Ranger Uranium Environmental Inquiry, nuclear safeguards, health and safety aspects of nuclear power generation, mining and milling safety and the impact of mining on Aboriginal society is also made. (J.R.)

  6. Uranium ore deposits

    International Nuclear Information System (INIS)

    The main uranium deposits and occurrences in the Argentine Republic are described, considering, in principle, their geologic setting, the kind of 'model' of the mineralization and its possible origin, and describing the ore species present in each case. The main uraniferous accumulations of the country include the models of 'sandstong type', veintype and impregnation type. There are also other kinds of accumulations, as in calcrete, etc. The main uranium production has been registered in the provinces of Mendoza, Salta, La Rioja, Chubut, Cordoba and San Luis. In each case, the minerals present are mentioned, having been recognized 37 different species all over the country (M.E.L.)

  7. Uranium conversion wastes

    International Nuclear Information System (INIS)

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

  8. Uranium exploration techniques

    International Nuclear Information System (INIS)

    The subject is discussed under the headings: introduction (genetic description of some uranium deposits; typical concentrations of uranium in the natural environment); sedimentary host rocks (sandstones; tabular deposits; roll-front deposits; black shales); metamorphic host rocks (exploration techniques); geologic techniques (alteration features in sandstones; favourable features in metamorphic rocks); geophysical techniques (radiometric surveys; surface vehicle methods; airborne methods; input surveys); geochemical techniques (hydrogeochemistry; petrogeochemistry; stream sediment geochemistry; pedogeochemistry; emanometry; biogeochemistry); geochemical model for roll-front deposits; geologic model for vein-like deposits. (U.K.)

  9. Concentrations of trace elements and radionuclides in four fish species from the Black Lake area of northern Saskatchewan

    International Nuclear Information System (INIS)

    Future expansion of uranium mines in northern Saskatchewan, as well as the presence of the small abandoned Nisto uranium mine on the north shore of Black Lake, have raised concerns over potential contaminants in fish consumed by local residents. This report presents results of analyses of six fish caught in Black Lake and Stony Lake by local residents and analyzed for radionuclides and trace elements. For comparison, a rainbow trout raised on a British Columbia fish farm was also analyzed. Food chain transfer of radionuclides and other elements was estimated by using concentrations in gastrointestinal tract samples to represent the food source of the fish. Elements analyzed include uranium, radium-226, lead-210, calcium, potassium, mercury, and chromium

  10. Production of sized particles of uranium oxides and uranium oxyfluorides

    International Nuclear Information System (INIS)

    A process is claimed for converting uranium hexafluoride (UF6) to uranium dioxide (UO2) of a relatively large particle size in a fluidized bed reactor by mixing uranium hexafluoride with a mixture of steam and hydrogen and by preliminary reacting in an ejector gaseous uranium hexafluoride with steam and hydrogen to form a mixture of uranium and oxide and uranium oxyfluoride seed particles of varying sizes, separating the larger particles from the smaller particles in a cyclone separator, recycling the smaller seed particles through the ejector to increase their size, and introducing the larger seed particles from the cyclone separator into a fluidized bed reactor where the seed particles serve as nuclei on which coarser particles of uranium dioxide are formed. 9 claims, 2 drawing figures

  11. Reactivity of ceramic coating materials with uranium and uranium trichlorid

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Sung Ho; Cho, Choon Ho; Lee, Yoon Sang; Lee, Han Soo; Kim, Jeong Guk [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2010-05-15

    Uranium and uranium alloys are typically induction melted in graphite crucibles under a vacuum. The graphite crucible is used for the manufacturing of uranium ingots in the casting equipment. But, due to the chemical reactivity of uranium and most alloying elements with carbon, a protective ceramic coating is generally applied to the crucibles. In this study, to investigate the most suitable ceramic coating material applied to graphite melting crucibles and ingot moldsused in the melting and casting of uranium in the casting equipment, firstly, the thermodynamic analysis was performed by using HSC software to investigate the reactivity between uranium and several ceramic materials and the experiments on the reaction of ceramic coated crucibles in molten uranium were carried out at 1300 .deg. C

  12. Reactivity of ceramic coating materials with uranium and uranium trichlorid

    International Nuclear Information System (INIS)

    Uranium and uranium alloys are typically induction melted in graphite crucibles under a vacuum. The graphite crucible is used for the manufacturing of uranium ingots in the casting equipment. But, due to the chemical reactivity of uranium and most alloying elements with carbon, a protective ceramic coating is generally applied to the crucibles. In this study, to investigate the most suitable ceramic coating material applied to graphite melting crucibles and ingot moldsused in the melting and casting of uranium in the casting equipment, firstly, the thermodynamic analysis was performed by using HSC software to investigate the reactivity between uranium and several ceramic materials and the experiments on the reaction of ceramic coated crucibles in molten uranium were carried out at 1300 .deg. C

  13. Key Lake pit development a formidable design challenge

    International Nuclear Information System (INIS)

    Interest in the mineral potential of the southeast rim of the Athabasca Basin was sparked in 1971 with the discovery of two uraniferous boulders 500 m from Key Lake. It was not until 1975, however, that geologists discovered the Gaertner deposit. The Deilmann deposit was drilled the following year. These two deposits, with combined reserves of over 3.5 million t grading 2.35 per cent U3O8, are the backbone of the non-communist world's largest uranium producer. Construction began at Key Lake in September 1981, following one of the most extensive public hearings ever held for a Canadian mining project. The Key Lake surface lease is one of this country's most stringent. Employment, training, business opportunities, environmental guidelines and monitoring processes are all spelled out in detail

  14. Preliminary cleanup activities at vicinity properties near Salt Lake City, Utah: Environmental assessment

    International Nuclear Information System (INIS)

    This document describes the preliminary cleanup activities and their impacts for the approximately 100 properties in Salt Lake Valley that have been contaminated by radioactive tailings from the site of the inactive Vitro uranium mill. The 23 properties already included on the official list for cleanup have been used as the basis for estimating impacts at all 100 sites

  15. UMTRA Project water sampling and analysis plan, Salt Lake City, Utah. Revision 1

    International Nuclear Information System (INIS)

    This water sampling and analysis plan describes planned, routine ground water sampling activities at the US Department of Energy Uranium Mill Tailings Remedial Action Project site in Salt Lake City, Utah. This plan identifies and justifies sampling locations, analytical parameters, detection limits, and sampling frequencies for routine monitoring of ground water, sediments, and surface waters at monitoring stations on the site

  16. Hydrogeochemical and stream sediment reconnaissance basic data for Chandler Lake Quadrangle, Alaska

    International Nuclear Information System (INIS)

    Field and laboratory data are presented for 616 water samples from the Chandler Lake Quadrangle, Alaska. The samples were collected by Los Alamos Scientific Laboratory; laboratory analysis and data reporting were done by the Uranium Resource Evaluation Project at Oak Ridge, Tennessee

  17. The genesis of surficial uranium deposits

    International Nuclear Information System (INIS)

    Surficial uranium deposits can form in such diverse environments as calcareous-dolomitic-gypsiferous fluvial and aeolian valley sediments in hot arid and semi-arid regions, oxidizing and reducing alkaline and saline playas, highly organic and/or clay-rich wetland areas, calcareous regoliths in arid terranes, laterites, lake sediments, and highly fractured zones in igneous and metamorphic basement complexes. Formation of ore is governed by the interrelationships between source of ore-forming elements, mechanisms of migration, environment of deposition, climate, preservation, tectonic history and structural framework. The principal factors controlling mobilization of ore-forming elements from source to site of deposition are the availability of elements in source rocks, presence of complexing agents, climate, nature of source rock regolith and structure of source rock terrane. The major processes governing precipitation of uranium in the surficial environment are reduction mechanisms, sorption processes, dissociation of uranyl complexes, change in redox states of ore-forming constituents, evaporation of surface and groundwaters, change in partial pressure of dissolved carbon dioxide, changes in pH, colloidal precipitation, and mixing of two or more surface and groundwaters. One or a number of these processes may be actively involved in ore formation. (author)

  18. Uranium sorption by tannin resins

    International Nuclear Information System (INIS)

    The sorption of uranium by immobilised Eucalyptus Saligna Sm. and Lysiloma latisiliqua L tannins was investigated. Immobilization condition were analyzed. These resins resulted suitable adsorbent for the concentration of uranium from aqueous systems. The sorption of uranium is pH dependent. At pH 5.5 maximum in sorption capacity is registered. The presence of appreciable amount of sodium chloride do not have any effect on uranium removal. Carbonate and calcium ions in concentrations similar to these that could be found in sea water and other natural water do not decrease the uranium uptake. Tannin resins can be used several times without an appreciable decay of their sorption capacity

  19. Uranium mineralization in fluviatile facies

    International Nuclear Information System (INIS)

    Over half the world's known uranium reserves occur in fluviatile rocks. These deposits include Archean quartz-pebble conglomerates of alluvial fan facies and arkosic braided and meandering fluviatile sandstone facies. Uranium-bearing quartz-pebble conglomerates are described. Approximately 40% of the world's uranium reserves have been found in epigenetic sandstone deposits. Deposits of uranium in braided or meandering fluviatile sandstones can be grouped into peneconcordant and roll-front types. Uranium deposits are widely distributed through central, northern and western Australia but only a very small proportion of the reserves occur in fluviatile sequences

  20. Eldorado plans second uranium refinery

    International Nuclear Information System (INIS)

    Eldorado Nuclear Ltd. intends to open a new uranium refinery at Port Granby, Ont., by 1980, thereby tripling output of uranium hexafluoride. In the 1980's, the company plans to build a third refinery in Saskatchewan. The process of producing uranium hexafluoride from crude yellowcake is explained, and improvements introduced by Eldorado are discussed. They include a continuous denitrator for producing uranium trioxide, and 'pillow block' briquetting rollers for briquetting it before it is reduced with hydrogen to uranium dioxide. (N.D.H.)