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)

Cullington, B.J.

1990-01-01

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

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

International Nuclear Information System (INIS)

1981-10-01

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 U 3 O 8 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

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

1995-11-01

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

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)

1993-04-01

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

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

International Nuclear Information System (INIS)

Granger, H.C.; Santos, E.S.

1986-01-01

The Section 23 mine is one of about 18 large uranium mines opened in sandstones of the fluvial Westwater Canyon Member of the Jurassic Morrison Formation, in the Ambrosia Lake 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

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

International Nuclear Information System (INIS)

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

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

International Nuclear Information System (INIS)

1996-02-01

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

Geology and ore deposits of Johnny M mine, Ambrosia Lake District

International Nuclear Information System (INIS)

Falkowski, S.K.

1980-01-01

The Johnny M mine is one of very few mines in the Ambrosia Lake district with uranium ore in two members of the Morrison Formation (Jurassic); these members are the Westwater Canyon Sandstone and the Brushy Basin Shale. The Westwater Canyon ore is contained in the two upper sandstone units of the member, and the Brushy Basin ore is contained in the Poison Canyon sandstone (informal usage). The sedimentary features and structures in the Westwater Canyon sandstones indicate that the sediments were deposited by a system of aggrading braided streams, possibly at the distal end of coalescing alluvial fans. The Poison Canyon sandstone was probably the result of deposition in a complex environment of meandering and braided streams. Paleocurrent-direction indicators, such as fossilized-log orientation, foreset azimuths, and the axes of crossbeds and channel scours, suggest that the local palostream flow was to the east and southeast. The uranium mineralization is closely associated with 1) local accumulations of carbonaceous (humate) matter derived from the decay of organic material and 2) paleostream channels preserved in the rocks. The ore elements were derived from the leaching of volcanic air-fall tuffs and ash, which were introduced into the fluvial system during volcanic activity in the western United States. The mobile ore-element ions were reduce and concentrated by humic acids and bacteria present in the fluvial system and ultimately remobilized into the forms present today. The uranium is thus envisioned as forming either essentially on the surface as the sediments were being deposited or at very shallow depth

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

International Nuclear Information System (INIS)

Lapham, S.C.; Millard, J.B.; Samet, J.M.

1989-01-01

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 238 U, 234 U, 230 Th, 226 Ra, 210 Pb, and 210 Po. 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 226 Ra and 210 Po. 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

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

Data Validation Package December 2015 Groundwater Sampling at the Ambrosia Lake, New Mexico, Disposal Site March 2016

Energy Technology Data Exchange (ETDEWEB)

Tsosie, Bernadette [USDOE Office of Legacy Management, Washington, DC (United States); Johnson, Dick [Navarro Research and Engineering, Inc., Oak Ridge, TN (United States)

2016-03-01

The Long-Term Surveillance Plan for the Ambrosia Lake, New Mexico, Disposal Site does not require groundwater monitoring because groundwater in the uppermost aquifer is of limited use, and supplemental standards have been applied to the aquifer. However, at the request of the New Mexico Environment Department, the U.S. Department of Energy conducts annual monitoring at three locations: monitoring wells 0409, 0675, and 0678. Sampling and analyses were conducted as specified in the Sampling and Analysis Plan for US. Department of Energy Office of Legacy Management Sites (LMS/PRO/S04351, continually updated). Monitoring Well 0409 was not sampled during this event because it was dry. Water levels were measured at each sampled well. One duplicate sample was collected from location 0675. Groundwater samples from the two sampled wells were analyzed for the constituents listed in Table 1. Time-concentration graphs for selected analytes are included in this report. At well 0675, the duplicate results for total dissolved solids and for most metals (magnesium, molybdenum, potassium, selenium, sodium, and uranium) were outside acceptance criteria, which may indicate non-homogeneous conditions at this location. November 2014 results for molybdenum and uranium at well 0675 also were outside acceptance criteria. The well condition will be evaluated prior to the next sampling event.

Uranium Geochemistry in Hypersaline Soda Lakes in Eastern Mongolia

Science.gov (United States)

Linhoff, B. S.; Bennett, P.; Puntsag, T.

2007-12-01

Extremely high concentrations of uranium were discovered in water samples from hypersaline soda lakes in eastern Mongolia. The origin and fate of uranium in these lakes was examined using geochemical analyses and modeling, using samples collected from five lakes, six wells and one stream. Samples were analyzed for strontium and uranium isotopes, cations and trace metals, anions, alkalinity, and unstable field parameters. The lakes are small, shallow (chlorine to bromine ratios implying groundwater discharges to lake water and is subsequently evaporated. Evaporation is intense with lake waters having average chlorine concentrations 300 times that of well waters. Uranium in well samples is higher than typical for shallow groundwaters (7-101ppb) suggesting discharging groundwater as a probable source of uranium in lake water. Concentrations of uranium in lake water ranges from 57-14,900ppb making these lakes possibly the highest naturally occurring uranium concentration reported. Lake water alkalinity is strongly correlated to uranium abundance suggesting uranium is complexed with carbonate as the aqueous species UO2CO3. Consequently, the extremely high alkalinity of the most alkaline lake (pH = 9.8, 1288.8 meq alk/L) also has the highest uranium concentrations. Stable strontium isotopes were used to assess the degree of water rock interactions and the presence of 90Sr was checked for to test the possibility of input of nuclear fallout. 90Sr was not detected in lake water samples suggesting the high uranium is of natural origins. A large difference in the 87Sr/86Sr ratio was found between groundwater and lake water samples. Groundwater samples displayed large variation in the 87Sr/86Sr ratio (0.70612-0.709776) whereas lake water samples averaged a high radiogenic ratio (0.709432). The large variation in the strontium isotopes in groundwater samples suggests varying degrees of water rock interactions, however the least radiogenic samples likely are derived from

Lake Austin uranium deposit, Western Australia

International Nuclear Information System (INIS)

Heath, A.G.; Deutscher, R.L.; Butt, C.R.M.

1984-01-01

The Lake Austin uranium deposit is a calcrete type deposit in the Yilgarn Block, near Cue, in a catchment area of granitoids and greenstones. The uranium is in valley fill and the sediments of the Lake Austin playa. The mineralization occurs over 1 to 6 meter thickness close to the water table in calcrete overlying clays and/or weathered bedrock. The principal uranium mineral is carnotite. Waters in nearby channels have an uranium content of over 30 ppb. The chloride content of the water increases downstream in the nearby drainages, as does the uranium and vanadium content. (author)

Possible pitfalls in the search for uranium deposits using lake sediments and lake waters

International Nuclear Information System (INIS)

Levinson, A.A.; Bland, C.J.

1978-01-01

The organic-rich sediments from the centres of Canadian lakes are a valuable sampling medium in the search for uranium. However, because of the young age of hydromorphically transported uranium in these sediments, which must post-date the last period of glaciation, there has been insufficient time for the isotope 214 Bi to reach equilibrium with its ancestor 238 U. This results in equivalent uranium (eU) values significantly lower than actual uranium values determined by fluorometry or delayed neutron activation analysis. Radiometric ( 226 Ra) analyses of 12 centre-lake sediments from Seahorse Lake, Saskatchewan illustrate the potential pitfalls which may be encountered using gamma-ray spectrometry, as only 3-8% of the actual uranium present in most of the samples would have been detected. (author)

Uranium distribution in relation to sedimentary facies, Kern Lake, California

International Nuclear Information System (INIS)

Merifield, P.M.; Carlisle, D.; Idiz, E.; Anderhalt, R.; Reed, W.E.; Lamar, D.L.

1980-04-01

Kern Lake has served as a sink for drainage from the southern Sierra Nevada and, in lesser amounts, from the southern Temblor Range. Both areas contain significant uranium source rocks. The uranium content in Holocene Kern Lake sediments correlates best with the mud (silt and clay) fraction. It correlates less well with organic carbon. Biotite grains could account for much of the uranium in the sand fraction, and perhaps the silt fraction as well. The data suggest that fixation of uranium by adsorption on mineral grains is a dominant process in this lake system. Further work is required to determine the importance of cation-exchange of uranium on clays and micas and of organically complexed uranium adsorbed to mineral surfaces. These findings also raise the question of whether uranium transport down the Kern River occurs largely as uranium adsorbed to mineral surfaces

The McClean Lake uranium project

International Nuclear Information System (INIS)

Blaise, J.R.

2001-01-01

The McClean Lake Uranium Project, located in the northern part of Saskatchewan, consists of five uranium deposits, Jeb - Sue A - Sue B - Sue C - McClean, scattered in three different locations on the mineral lease. On 16 March 1995, COGEMA Resources Inc and its partners, Denison Mines Ltd and OURD (Canada) Co Ltd, made the formal decision to develop the McClean Lake Project. Construction of the mine and mill started during summer 1995 and should be finished by mid 1997. Mining of the first deposit, Jeb started in 1996, ore being currently mined. The start of the yellowcake production is scheduled to start this fall. (author)

Exploration of the Key Lake uranium deposits, Saskatchewan, Canada

International Nuclear Information System (INIS)

Gatzweiler, R.; Schmeling, B.; Tan, B.

1981-01-01

In 1969, one year after the discovery of the Rabbit Lake uranium deposit, exploration started in the Key Lake area as part of a major uranium rush into Northern Saskatchewan, and within the frame of a joint venture. The area was not chosen on the basis of a particular metallogenetic concept. The lack of exploratory success in 1969 and 1970, together with the introduction in March 1970 of foreign ownership restrictions for uranium mining in Canada, discouraged six of the nine companies forming the original joint venture. In 1971 the three remaining companies decided to continue under a redefined concept, based on the knowledge obtained from the Rabbit Lake deposit (Uranerz had acquired a 49% share in 1970) and from the newly discovered uranium deposits in the Pine Creek Geosyncline, Australia. In the same year, exploration work resulted in the discovery of two high-grade mineralized boulders and significant radioactive and geochemical anomalies 5 km SW of Key Lake deposits. Subsequent exploration, aimed at finding the source of the mineralized boulders, comprised geological, glacial geological and ground radiometric surveys, boulder tracing, air-photo interpretation, lake sediment and muskeg sampling surveys, radon surveys, ground magnetic, gravity, electromagnetic and IP surveys, and drilling. The systematic exploration efforts resulted in the discovery of the Gaertner ore body in July 1975 and the Deilmann ore body in June 1976, where glacial geology, lake sediment sampling, magnetic and electromagnetic surveys were the key methods in defining the drilling targets. Three further years and a total of about 2400 drillholes were needed to fully delineate the two ore bodies. (author)

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

International Nuclear Information System (INIS)

Sopuck, V.J.; Lehto, D.A.W.; Alley, D.W.

1980-03-01

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

Settlement of uranium mill tailings

International Nuclear Information System (INIS)

Chen, P.K.; Guros, F.B.; Keshian, B.

1988-01-01

Two test embankments were constructed on top of an old tailings deposit near Ambrosia Lake, New Mexico to determine settlement characteristics of hydraulically- deposited uranium mill tailings. Before construction of the embankments, properties of in-situ tailings and foundation soils were determined using data from boreholes, piezocone soundings, and laboratory tests. These properties were used to estimate post-construction settlement of a planned disposal embankment to be constructed on the tailings. However, excessive uncertainty existed in the following: field settlement rates of saturated and unsaturated tailings, degree of preconsolidation of the upper 15 feet of tailings, and the ability of an underlying silty sand foundation layer to facilitate drainage. Thus, assurance could not be provided that differential settlements of the radon barrier and erosion protection layers would be within allowable limits should the planned disposal embankment be constructed in a single-stage

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

International Nuclear Information System (INIS)

Fishman, N.S.; Reynolds, R.L.

1986-01-01

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

Chlorine-assisted leaching of Key Lake uranium ore

International Nuclear Information System (INIS)

Haque, K.E.

1981-04-01

Bench-scale chlorine-assisted leach tests were conducted on the Key Lake uranium ore. Leach tests conducted at 80 0 C on a slurry containing 50% solids during 10 hours of agitation gave the maximum extraction of uranium - 96% and radium-226 - 91%. Chlorine was added at 23.0 Kg Cl 2 /tonne of ore to maintain the leach slurry pH in the range of 1.5-1.0. To obtain residue almost free of radionuclides, hydrochloric acid leaches were conducted on the first stage leach residues. The second stage leach residue still was found to contain uranium - 0.0076% and radium-226 - 200 pCi/g of solids

Midwest Lake uranium discovery, Saskatchewan, Canada

International Nuclear Information System (INIS)

Scott, F.

1981-01-01

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)

Recent Developments in the Treatment of Uranium Ores from the Elliot Lake District

Energy Technology Data Exchange (ETDEWEB)

Downes, K W [Extraction Metallurgy Division, Department of Mines and Technical Surveys, Ottawa (Canada)

1967-06-15

A summary of the results obtained during investigations on the treatment of uranium ores from the Elliot Lake district in the laboratories of the Mines Branch, and of developments in operating procedures introduced in the uranium mills in the Elliot Lake district, is presented. Concentration of Elliot Lake ore on a pilot-plant scale by a combined gravity-flotation procedure yielded a 90% recovery of uranium at a ratio of concentration of 2.4 to 1.0. The mineralogical composition of the ore, the flow sheet used and the reagents employed are described. An approximate cost estimate indicates that, although the capacity of an existing uranium leaching plant would be doubled by introducing the procedure, the production cost per pound of U{sub 3}0{sub 8} would not be affected. Bacterial leaching of Elliot Lake ore on a laboratory scale yielded, under favourable conditions, extractions of 90 per cent in 5 weeks, and of 95 per cent in 15 weeks. The conditions that were found to influence the leaching results are outlined, and the effects of the leaching solutions are discussed. The purification of ion exchange eluates by liquid-liquid extraction, using tri-n-butyl phosphate, dibutyl butylphosphonate and tri-capryl amine in a continuous process, yielded solutions from which refined ammonium diuranate was precipitated using gaseous ammonia. The effectiveness of the three extractants is discussed, and the effects of the procedures employed on the production costs per pound of U{sub 3}O{sub 8} is estimated. Some improvements in operating procedures introduced in the Elliot Lake district uranium mills are briefly described, and their effects on the operations are indicated. Present methods of controlling radiological pollution of drainage waters by uranium mill tailings are outlined. (author)

Geochemistry of the Cigar Lake uranium deposit: XPS studies

International Nuclear Information System (INIS)

Sunder, S.; Cramer, J.J.; Miller, N.H.

1996-01-01

Samples of uranium ore from the Cigar Lake deposit in northern Saskatchewan, Canada, were analyzed using XPS. High-resolution spectra were recorded for the strongest bands of the major elements (U 4f, C 1 s, O 1 s, Pb 4 f, S 2 p, Cu 2 p, Fe 2 p, and the valence region (0-20 eV)) to obtain chemical state information for these samples. In general, the U VI /U IV ratio was very low, i.e., much less than 0.5, the threshold for the oxidative dissolution of UO 2 . The low values of the U VI /U IV ratio observed for samples from the Cigar Lake deposit indicate thermodynamic stability of the uranium ore in the reduced aqueous environment. Similarities between the disposal vault envisaged in the Canadian Nuclear Fuel Waste Management Program and the Cigar Lake deposit suggest that, if geochemical conditions in the vault were to be similar to those in the deposit, the long-term dissolution of UO 2 fuel would be very minimal. (orig.)

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

International Nuclear Information System (INIS)

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

2005-01-01

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

Ragweed (Ambrosia) pollen source inventory for Austria.

Science.gov (United States)

Karrer, G; Skjøth, C A; Šikoparija, B; Smith, M; Berger, U; Essl, F

2015-08-01

This study improves the spatial coverage of top-down Ambrosia pollen source inventories for Europe by expanding the methodology to Austria, a country that is challenging in terms of topography and the distribution of ragweed plants. The inventory combines annual ragweed pollen counts from 19 pollen-monitoring stations in Austria (2004-2013), 657 geographical observations of Ambrosia plants, a Digital Elevation Model (DEM), local knowledge of ragweed ecology and CORINE land cover information from the source area. The highest mean annual ragweed pollen concentrations were generally recorded in the East of Austria where the highest densities of possible growth habitats for Ambrosia were situated. Approximately 99% of all observations of Ambrosia populations were below 745m. The European infection level varies from 0.1% at Freistadt in Northern Austria to 12.8% at Rosalia in Eastern Austria. More top-down Ambrosia pollen source inventories are required for other parts of Europe. A method for constructing top-down pollen source inventories for invasive ragweed plants in Austria, a country that is challenging in terms of topography and ragweed distribution. Crown Copyright © 2015. Published by Elsevier B.V. All rights reserved.

Herbarium collection-based phylogenetics of the ragweeds (Ambrosia, Asteraceae).

Science.gov (United States)

Martin, Michael D; Quiroz-Claros, Elva; Brush, Grace S; Zimmer, Elizabeth A

2018-03-01

Ambrosia (Asteraceae) is a taxonomically difficult genus of weedy, wind-pollinated plants with an apparent center of diversity in the Sonoran Desert of North America. Determining Ambrosia's evolutionary relationships has been the subject of much interest, with numerous studies using morphological characters, cytology, comparative phytochemistry, and chloroplast restriction site variation to produce conflicting accounts the relationships between Ambrosia species, as well as the classification of their close relatives in Franseria and Hymenoclea. To resolve undetermined intra-generic relationships within Ambrosia, we used DNA extracted from tissues obtained from seed banks and herbarium collections to generate multi-locus genetic data representing nearly all putative species, including four from South America. We performed Bayesian and Maximum-Likelihood phylogenetic analyses of six chloroplast-genome and two nuclear-genome markers, enabling us to infer monophyly for the genus, resolve major infra-generic species clusters, as well as to resolve open questions about the evolutionary relationships of several Ambrosia species and former members of Franseria. We also provide molecular data supporting the hypothesis that A. sandersonii formed through the hybridization of A. eriocentra and A. salsola. The topology of our chloroplast DNA phylogeny is almost entirely congruent with the most recent molecular work based on chloroplast restriction site variation of a much more limited sampling of 14 North American species of Ambrosia, although our improved sampling of global Ambrosia diversity enables us to draw additional conclusions. As our study is the first direct DNA sequence-based phylogenetic analyses of Ambrosia, we analyze the data in relation to previous taxonomic studies and discuss several instances of chloroplast/nuclear incongruence that leave the precise geographic center of origin of Ambrosia in question. Copyright © 2017 Elsevier Inc. All rights reserved.

Uranium Mill Tailings Remedial Action Project 1994 environmental report

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

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.

Uranium Mill Tailings Remedial Action Project 1994 environmental report

International Nuclear Information System (INIS)

1995-08-01

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

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

International Nuclear Information System (INIS)

Miller, A.R.

1980-01-01

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)

Prospecting exploration and development of the uranium deposits Key Lake, Canada

International Nuclear Information System (INIS)

Kirchner, G.; Tan, B.H.

1977-01-01

This lecture gives a survey of the methods employed by the Uranerzbergbau-GmbH and Co. KG and the experience gained in connection with prospecting and exploration activities at the uranium deposits in Saskatchewan, illustrated by the case history Key Lake. (orig.) [de

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

International Nuclear Information System (INIS)

1993-11-01

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1993-11-01

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.

Assay of Uranium Isotopic Ratios 234U/238U, 235U/238U in Bottom Sediment Samples Using Destructive and Non Destructive Techniques (Nasser Lake)

International Nuclear Information System (INIS)

Agha, A.R.; El-Mongy, S.A.; Kandel, A.E.

2011-01-01

Nasser Lake is the greatest man-made lake in the World. It is considered as the main source of water where the Nile water is impounded behind the Aswan high dam.. Uranium has three naturally occurring isotopes 234 U, 235 U and 238 U with isotopic abundance 0.00548, 0.7200 and 99.2745 atom percent. Dissolved uranium in the lake is primary due to weathering process. Monitoring of the isotopic ratios of uranium is used as a good indicator to trace and evaluate the origin and activities associated with any variation of uranium in the lake environment. The main objective of the present study is to clarify any potential variation of natural uranium 234 U/ 238 U, 235 U/ 238 U ratios in sediment samples of Nasser Lake by using destructive alpha and non destructive gamma- techniques. The results show that the uranium isotopic activity ratios are very close to the natural values. This study can also be used for radiological protection and safety evaluation purposes.

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)

Hydrochloric acid leach of Agnew Lake uranium concentrate

International Nuclear Information System (INIS)

Haque, K.E.; Ipekoglue, B.

1981-10-01

Hydrochloric acid leaching was conducted on the radioactive mineral concentrate separated from the Agenw Lake uranium ore. Leach tests conducted at the optimum conditions (75 0 C; 36 hours; 66.0 Kg HCl/tonne; solid:liquid -1:1) resulted in the extraction of 87% uranium and 84% radium. The radionuclide level of the residue was U-0.016%, Th-0.24% and Ra-65 pCi/g solids. However to obtain a residue almost free of radium (i.e., Ra level at the detection limit: 4-6 pCi/g solids), the first stage leach residue was further treated with hydrochloric acid. The radium level in the best second stage leach residue was also above the target level. Therefore, multistage (3 or 4) hydrochloric acid and/or neutral chloride leaching is recommended to obtain tailings almost free of radionuclide

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

International Nuclear Information System (INIS)

Cramer, J.J.

1995-05-01

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 UO 2 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

New gSSR and EST-SSR markers reveal high genetic diversity in the invasive plant Ambrosia artemisiifolia L. and can be transferred to other invasive Ambrosia species.

Science.gov (United States)

Meyer, Lucie; Causse, Romain; Pernin, Fanny; Scalone, Romain; Bailly, Géraldine; Chauvel, Bruno; Délye, Christophe; Le Corre, Valérie

2017-01-01

Ambrosia artemisiifolia L., (common ragweed), is an annual invasive and highly troublesome plant species originating from North America that has become widespread across Europe. New sets of genomic and expressed sequence tag (EST) based simple sequence repeats (SSRs) markers were developed in this species using three approaches. After validation, 13 genomic SSRs and 13 EST-SSRs were retained and used to characterize the genetic diversity and population genetic structure of Ambrosia artemisiifolia populations from the native (North America) and invasive (Europe) ranges of the species. Analysing the mating system based on maternal families did not reveal any departure from complete allogamy and excess homozygosity was mostly due the presence of null alleles. High genetic diversity and patterns of genetic structure in Europe suggest two main introduction events followed by secondary colonization events. Cross-species transferability of the newly developed markers to other invasive species of the Ambrosia genus was assessed. Sixty-five percent and 75% of markers, respectively, were transferable from A. artemisiifolia to Ambrosia psilostachya and Ambrosia tenuifolia. 40% were transferable to Ambrosia trifida, this latter species being seemingly more phylogenetically distantly related to A. artemisiifolia than the former two.

Environmental assessment: Uranium Geologic Drilling Project, Winnemucca Dry Lake, Pershing, Nevada

International Nuclear Information System (INIS)

This environmental assessment has been prepared to provide the environmental input into the DOE decision to drill and log ten (10) holes of under 7-in. diameters to depths of 100 to 1500 feet in the northern margin of Winnemucca Dry Lake, Pershing County, Nevada, to obtain subsurface information related to uranium favorability

Prospecting and exploration of the Key Lake uranium deposits, Saskatchewan, Canada

International Nuclear Information System (INIS)

Tan, B.H.

1980-01-01

The research activities which led to the detection of the Key Lake deposit and their model character for uranium prospecting in this area are discussed. The genesis of the ores and the surrounding rocks are described, and the possible genesis of the deposit is discussed on the basis of the present state of knowledge. (HP) [de

Radionuclide levels in vegetation growing on uranium tailings, Elliot Lake, Ontario

International Nuclear Information System (INIS)

Pave, N.K.; Cloutier, N.R.; Lim, T.P.

1985-01-01

In Elliot Lake, Ontario, Canada, most of the inactive uranium tailings have been reclaimed by revegetation where a thick vegetation cover has been established. The surface amendments have also prompted volunteer growth of various species of local trees and shrubs on tailings. Radionuclide levels were measured in various tissues of grasses, legumes and trees growing on uranium tailings at different sites. 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

Uranium deposit research, 1983

International Nuclear Information System (INIS)

Ruzicka, V.; LeCheminant, G.M.

1984-01-01

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

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

International Nuclear Information System (INIS)

Brierley, C.L.; Brierley, J.A.

1981-12-01

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

Expansion of the uranium mines in the Elliot Lake area

International Nuclear Information System (INIS)

1979-11-01

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.)

Chemical ecology and serendipity: Developing attractants for Florida ambrosia beetle pests

Science.gov (United States)

Two exotic ambrosia beetles have become established in southern Florida: Xyleborus glabratus, the redbay ambrosia beetle (RAB), and Euwallacea fornicatus, the tea shot hole borer (TSHB). Both pests vector pathogenic fungal symbionts; the former for laurel wilt and the latter for Fusarium dieback d...

Estimating calibration equations for predicting Ra-226 soil concentrations using RTRAK in-situ detectors at the Ambrosia Lake, New Mexico, Umtra site

International Nuclear Information System (INIS)

Gilbert, R. O.; Meyer, H. R.; Miller, M. L.; Begley, C.

1988-06-01

This report describes a field study conducted at the Ambrosia Lake, New Mexico, UMTRA site to obtain data for calibrating the RTRAK Sodium Iodide (NaI) detectors for estimating concentrations of Ra-226 in surface soil. The statistical analyses indicate that the data are useful for estimating the calibration equations. Several statistical models are used to evaluate which model is best as a basis for the calibration equations. A procedure is provided for using the estimated calibration equations and extensive RTRAK measurements to estimate the average Ra-226 concentration on 100-m 2 land areas to determine whether additional remedial action is needed. The UMTRA Project office proposes to use the RTRAK for cleanup verification of surface Ra-226 contamination. The system enables 100% coverage of areas having undergone remedial action. The sensitivity of the system enables verification at less than 5 pCi/g averaged over 100 m 2 , as specified by the Environmental Protection Agency (EPA) standards (40 CFR Part 192). This analysis demonstrates RTRAK's ability to meet reasonable standards of statistical accuracy, using commonly accepted procedures. 5 refs., 8 figs., 1 tab

36Cl production and mobility in the Cigar Lake uranium deposit

International Nuclear Information System (INIS)

Cornett, R.J.; Fabryka-Martin, J.; Cramer, J.J.; Andrew, H.R.; Koslowsky, V.T.

2010-01-01

Can accelerator mass spectrometry (AMS) studies validate risk assessments of the long-term behaviour of contaminants such as radionuclides? AMS measurements on samples from the 1.3 billion-year-old Cigar Lake uranium ore deposit provide one approach to address this question. In Cigar Lake, elevated concentrations of uranium enhance the in situ neutron flux that produces 36 Cl and other radionuclides. We calculated the production of 36 Cl using a Monte Carlo neutron transport code. We then tested for the loss of 36 Cl from ore samples collected from an 8 m stratigraphic section through the deposit by comparing the predicted values (assuming equilibrium between production and decay) with the concentrations measured by AMS. The 36 Cl:Cl atom ratios within the ore were more than two orders of magnitude higher than in the surrounding host rock and ranged from 4 to 64 x 10 -12 . The 36 Cl concentrations in the ore, rock, clay and fracture infilling minerals all agree with the values predicted by the Monte Carlo simulations. We conclude that 36 Cl has very limited mobility. Even in matrix adjacent to more permeable fractures, there is no evidence that the measured isotopic ratios deviate significantly from the predicted values.

The geology of the Cluff Lake uranium deposits

International Nuclear Information System (INIS)

Harper, C.T.

1978-01-01

The uranium deposits discovered by Amok (Canada) Ltd. in the Cluff Lake area of northwestern Saskatchewan occur at or near the southern edge of the uplifted basement core of the Carswell circular structure. Two types of mineralization, distinguishable by their geological and structural setting and mineral paragenesis, have been recognized. The N-Claude type is characterized by a relatively simple mineral assemblage, consisting of uraninite or pitchblende with coffinite, and is accompanied by variable amounts of graphite and organic matter, and Fe, Cu, Pb and Mo sulphides. Both N and Claude orebodies occur within quartzofeldpathic gneisses of the basement core. On the other hand, the D-type ore has a complex mineral assemblage consisting of: uraninite, pitchblende, tucholite and coffinite, along with native gold and selenium; gold tellurides, and selenides of Pb, Bi, Ni and Co; sulphides of Fe, Cu and Pb; and organic matter. The D orebody occurs within carbonaceous shales at the base of the Athabasca Formation as well as in fault zones in regolithic quartzofeldspathic gneisses above the inverted unconformity. An age of 1050 m.y., which is consistent with a period (circa 1200-1000 m.y.) of widespread hydrothermal activity and uranium mineralization or reworking within and adjacent to the Athabasca Basin, has been obtained from uranium mineralization from the D orebody. Later reworking (circa 470 m.y.) of the mineralization occurred at the intersection of older mineralized shear zones with radial faults produced during meteorite impact. (auth)

Simulation of weathering processes of uranium-nickel ore from Key Lake, Sask., Canada - a contribution of uranium mineralogy to environmental protection

International Nuclear Information System (INIS)

Pechmann, E. von; Voultsidis, V.

1979-01-01

The impact of frost and rain on stockpiles of uranium-nickel or from the Key Lake deposits has been investigated in simulation tests. Frost splitting causes strong disaggregation of the rock and fragmentation of the mineral grains. The ore is much less affected in the sandstone than in the mylonitized basement. During the tests, the uranium minerals have nearly not been weathered. The nickel minerals are quickly transformed into water soluble secondary minerals (sulphates and arsenate). The weathering effects on stored ore depend on the degree of ore comminution and its exposition to the atmospheric elements. (orig.) [de

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

International Nuclear Information System (INIS)

Cook, J.R.

1982-05-01

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 1 0 x 2 0 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

Canadian experience with uranium tailings disposal

International Nuclear Information System (INIS)

Culver, K.B.

1982-06-01

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

Alternative management techniques for the uranium mill tailings site at Salt Lake City, UT

International Nuclear Information System (INIS)

Rogers, V.C.; Goldsmith, W.A.; Haywood, F.F.; Gantner, G.K.

1976-01-01

The concentrations of 226 Ra and other uranium-chain radionuclides present in tailings piles at uranium-milling sites are on the order of 10 3 times higher than those usually found in soil-surface minerals. The public radiation exposure attributable to these sites is primarily due to inhalation of 222 Rn progeny. This paper presents the radiological assessment of the uranium-milling site at Salt Lake City, Utah. Adverse health effects are estimated from present and projected public radiation exposures. Three alternative remedial action measures can be used to reduce radiation exposures: (1) decontamination of offsite areas contaminated by tailings materials; (2) covering the tailings with contamination-free material; and (3) removal of the tailings to a more remote location. These three measures are examined in terms of costs incurred and serious health effects avoided

Symbiont diversification in ambrosia beetles: Diversity of fungi associated with exotic scolytine beetles

Science.gov (United States)

In virtually every forest habitat, ambrosia beetles (Coleoptera: Curculionidae: Scolytinae, Platypodinae) plant and maintain symbiotic fungus gardens inside dead or dying wood. Some introduced ambrosia beetles aggressively attack live trees and can damage tree crops, lumber, and native woody plant t...

Patterns of functional enzyme activity in fungus farming ambrosia beetles.

Science.gov (United States)

De Fine Licht, Henrik H; Biedermann, Peter H W

2012-06-06

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. 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. 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 accessible hemicellulose components of the ray

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

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

International Nuclear Information System (INIS)

Kelly, Jocelyn M.; Janz, David M.

2009-01-01

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

Bark and Ambrosia Beetles Show Different Invasion Patterns in the USA.

Directory of Open Access Journals (Sweden)

Davide Rassati

Full Text Available Non-native bark and ambrosia beetles represent a threat to forests worldwide. Their invasion patterns are, however, still unclear. Here we investigated first, if the spread of non-native bark and ambrosia beetles is a gradual or a discontinuous process; second, which are the main correlates of their community structure; third, whether those correlates correspond to those of native species. We used data on species distribution of non-native and native scolytines in the continental 48 USA states. These data were analyzed through a beta-diversity index, partitioned into species richness differences and species replacement, using Mantel correlograms and non-metric multidimensional scaling (NMDS ordination for identifying spatial patterns, and regression on distance matrices to test the association of climate (temperature, rainfall, forest (cover area, composition, geographical (distance, and human-related (import variables with β-diversity components. For both non-native bark and ambrosia beetles, β-diversity was mainly composed of species richness difference than species replacement. For non-native bark beetles, a discontinuous invasion process composed of long distance jumps or multiple introduction events was apparent. Species richness differences were primarily correlated with differences in import values while temperature was the main correlate of species replacement. For non-native ambrosia beetles, a more continuous invasion process was apparent, with the pool of non-native species arriving in the coastal areas that tended to be filtered as they spread to interior portions of the continental USA. Species richness differences were mainly correlated with differences in rainfall among states, while rainfall and temperature were the main correlates of species replacement. Our study suggests that the different ecology of bark and ambrosia beetles influences their invasion process in new environments. The lower dependency that bark beetles have

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.

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

International Nuclear Information System (INIS)

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

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. © The Author 2016. Published by Oxford University Press on behalf of the Entomological Society of America.

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

Uranium industry update

International Nuclear Information System (INIS)

Poissonnet, M.

1994-01-01

Canada is the world's largest producer of uranium. With stockpiles becoming depleted, new sources of production will soon be needed. Production in Ontario was expected to cease in 1996, leaving decommissioning as the main activity there. Present production in Canada is almost entirely from the Athabasca basin in Saskatchewan, and mainly from three mines, Key Lake and Rabbit Lake (both owned by Cameco and Uranerz), and Cluff Lake (owned by Cogema). Following hearings in 1993, extensions to Cluff Lake and Rabbit Lake, and a new project at McClean Lake (by Minatco) received environmental approval, while the Midwest project as presented by Denison was rejected, but Cogema was revising it (at the time of the conference). An environmental impact statement for Cigar Lake was due to be submitted to the Assessment panel in October 1994. The author regrets that discussion of 'natural analogues' has created confusion between uranium mining and nuclear waste disposal in the public mind. 2 ills

Close-out concepts for the Elliot Lake uranium mining operations

International Nuclear Information System (INIS)

Culver, K.B.; Chakravatti, J.L.; Gorber, D.M.; Knapp, R.A.; Davis, J.B.

1982-01-01

In the Elliot Lake area, approximately 100 million tonnes of tailings have been generated and deposited in ten separate management areas covering a total of 460 hectares. With continued placement of tailings into land-based management areas, the ultimate combined area covered with tailings would be in the order of 1500 to 2000 hectares. The principal environmental concerns associated with the land-based management areas in the long term (after mining has ceased), as seen by the Canadian regulatory authorities, are the potential of acid generation from pyrite oxidation, and the release and migration of radionuclides into air and water. The development of close-out criteria and concepts, therefore, has focussed on addressing these concerns. A position paper was issued for comment by the Canadian Atomic Energy Control Board on long-term aspects of uranium tailings management. In response, three of the uranium companies, Rio Algom Limited, Denison Mines Limited, and Eldorado Nuclear Limited, have countered with their own position and supported it with the extensive research on close-out procedures that has been carried out on their properties. The companies' position is that regulations should allow for site specific solutions and that institutional control is a valid long-term control option. As radiological loadings to air and water in the long term will be less than during operations, the only long-term concern in Elliot Lake is pyrite oxidation. Research has indicated that pyrite oxidation can be controlled in the upper zone of tailings. A summary of options available to control pyrite oxidation in this upper zone, including vegetation, limestone addition, pyrite removal, and physical cover is presented as well as preliminary cost estimates of each alternative. (author)

After twelve years of exploration Cluff Lake uranium within Amok's grasp

International Nuclear Information System (INIS)

Watson, L.M.

1979-01-01

Amok Ltd. recently began construction of a uranium mine and processing plant at Cluff Lake, Saskatchewan. The deposits occur in the Carswell Dome, a formation of basement rock intruding through the Athabaska sandstone which appears to have been caused by a meteorite impact approximately 467 million years ago. The uranium deposits are around 1 billion years old and are linked to organic compounds. Proven reserves are in the order of 23 000 million tonnes, averaging 7 percent U 3 O 8 but ranging from 0.3 to 45 percent. The D ore body, the richest, will be mined first in an open pit operation that will start up at 317 tpd in Sept. 1980. Special radiation protection precautions are necessary. Great care will be taken with mine wastes, waste water, and ore stockpiles to avoid groundwater contamination. High-grade ore can proceed directly to chemical treatment after crushing, while low-grade ore will receive gravity concentration. Sulphuric acid will be used to dissolve the uranium, followed by filtration, lime treatment to remove iron and aluminum, and neutralization with magnesium oxide to precipitate yellowcake. Radioactive wastes will be stored underground in concrete vaults; non-radioactive tailings will go to an impervious pond. (LL)

Approaches to control diseases vectored by ambrosia beetles in avocado and other American Lauraceae

Science.gov (United States)

Invasive ambrosia beetles and the plant pathogenic fungi they vector represent a significant challenge to North American agriculture, native and landscape trees. Ambrosia beetles encompass a range of insect species and they vector a diverse set of plant pathogenic fungi. Our lab has taken several bi...

Interaction of insecticide and media moisture on ambrosia beetle (Coleoptera: Curculionidae) attacks on ornamental trees

Science.gov (United States)

Exotic ambrosia beetles, particularly Xylosandrus crassiusculus (Motschulsky) and Xylosandrus germanus (Blandford), are among the most economically damaging pests of ornamental trees in nurseries. Growers have had few tactics besides insecticide applications to reduce ambrosia beetle attacks but rec...

137Cs radioactive dating of Lake Ontario sediment cores

International Nuclear Information System (INIS)

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

1987-12-01

The distribution of 137 Cs in sediment cores from Lake Ontario provides estimates of the sediment accumulation rates. Geochronology with 210 Pb dating and distribution of Ambrosia (ragweed) pollen compare well with 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

Summary of the engineering assessment of inactive uranium mill tailings. Vitro site, Salt Lake City, Utah

International Nuclear Information System (INIS)

1981-04-01

This report is a summary of a parent report (issued under separate cover) entitled Engineering Assessment of Inactive Uranium Mill Tailings for Vitro Site, Salt Lake City, Utah. Bacon and Davis Utah Inc. has reevaluated the Vitro site in order to revise the April 1976 assessment of the problems resulting from the existence of radioactive uranium mill tailings at Salt Lake City, Utah. 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 the 1.9 million tons of tailings at the Vitro 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 and off-site decontamination with the addition of 3 m of stabilization cover material (Option 1), to removal of the tailings to remote disposal sites, and decontamination of the tailings site (Options II through IV). Cost estimates for the four options range from about $36,400,000 for stabilization in-place, to about $91,000,000 for disposal at a distance of about 85 mi. Three principal alternatives for the reprocessing of the Vitro 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 $200/lb by heap leach and $130/lb by conventional plant processes. Spot market price for uranium was $28.00 in November 1980. Therefore, reprocessing the tailings for uranium recovery appears to be economically unattractive at present

Risk of exposure to airborne Ambrosia pollen from local and distant sources in Europe – an example from Denmark

Directory of Open Access Journals (Sweden)

Janne Sommer

2015-12-01

The high allergenic capacity of Ambrosia pollen means that only small amounts of pollen are relevant for allergy sufferers, and just a few plants will be sufficient to produce enough pollen to affect pollen allergy sufferers within a short distance from the source. It is necessary to adopt control measures to restrict Ambrosia numbers. Recommendations for the removal of all Ambrosia plants can effectively reduce the amount of local pollen, as long as the population of Ambrosia plants is small.

Root Exudation in Common Ragweed (Ambrosia Artemisiifolia L.)

Czech Academy of Sciences Publication Activity Database

Figala, J.; Hohnová, Barbora; Moravcová, Dana; Lvončík, S.; Lojková, L.; Formánek, P.

2016-01-01

Roč. 5, č. 5 (2016), s. 1034-1037 ISSN 2278-1862 Institutional support: RVO:68081715 Keywords : ambrosia artemisiifolia * root exudates * amino acids * aliphatic organic acids * allelopathy Subject RIV: CB - Analytical Chemistry, Separation

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

McClean Lake. Site Guide

International Nuclear Information System (INIS)

2016-09-01

Located over 700 kilometers northeast of Saskatoon, Areva's McClean Lake site is comprised of several uranium mines and one of the most technologically advanced uranium mills in the world - the only mill designed to process high-grade uranium ore without dilution. Areva has operated several open-pit uranium mines at the McClean Lake site, and is evaluating future mines at and near the site. The McClean Lake mill has recently undergone a multimillion-dollar upgrade and expansion, which has doubled its annual production capacity of uranium concentrate to 24 million pounds. It is the only facility in the world capable of processing high-grade uranium ore without diluting it. The mill processes the ore from the Cigar Lake mine, the world's second largest and highest-grade uranium mine. The McClean Lake site operates 365 days a year on a week-in/week-out rotation schedule for workers, over 50% of whom reside in northern Saskatchewan communities. Tailings are waste products resulting from milling uranium ore. This waste is made up of leach residue solids, waste solutions and chemical precipitates that are carefully engineered for long-term disposal. The TMF serves as the repository for all resulting tailings. This facility allows proper waste management, which minimizes potential adverse environmental effects. Mining projections indicate that the McClean Lake mill will produce tailings in excess of the existing capacity of the TMF. After evaluating a number of options, Areva has decided to pursue an expansion of this facility. Areva is developing the Surface Access Borehole Resource Extraction (SABRE) mining method, which uses a high-pressure water jet placed at the bottom of the drill hole to extract ore. Areva has conducted a series of tests with this method and is evaluating its potential for future mining operations. McClean Lake maintains its certification in ISO 14001 standards for environmental management and OHSAS 18001 standards for occupational health

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

International Nuclear Information System (INIS)

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

2012-01-01

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

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

International Nuclear Information System (INIS)

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

2011-01-01

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

Pathogenic microorganisms survival in ambrosia
Sobrevivência de micro-organismos patogênicos em ambrósia

OpenAIRE

Cláudio Dias Timm; Daiani Teixeira Silva; Priscila Alves Dias; Rita de Cássia Santos Conceição

2013-01-01

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 contamina...

Study on environmental background values of uranium in water of Dongting Lake system

International Nuclear Information System (INIS)

Zhai Pengji; Kang Tiesheng

1987-01-01

Study on environmental background values in water is the base of evaluating water quality and also is the foundational work of studying the law of distribution, accumulation and transfer of the elements. Research on background values of U in water not only can understand radioactive level but also has actual significance for the general survey of U by water. In the work uranium contents were determined by fission track analytical technique in the filtered and unfiltered specimens of river water, reservoir water and spring water taken from more than one hundred sections located in Dongting Lake system and the statistical process of data were carried out by computer. The environmental background values in water of various river system were obtained and compared with the situation of home and abroad. The seasonal variety of uranium content and the level of U in reservoir, spring water and natural reserve were discussed

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

International Nuclear Information System (INIS)

1982-03-01

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

Elliot Lake uranium mine reclamation, the first ten years

International Nuclear Information System (INIS)

Payne, R.A.

2000-01-01

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)

Ambrosia beetles associated with laurel wilt of avocado

Science.gov (United States)

Redbay ambrosia beetle, Xyleborus glabratus, 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 trees in the family Lauraceae. Laurel wilt has since spr...

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

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 their pollen. The NDA Panel concluded that inhalation of the plant pollen causes rhino-conjunctivitis and asthma, with skin allergies and food allergy playing minor roles. Ambrosia may cross-sensitize patients to other allergens, including food allergens. There is some evidence for allergenicity of Ambrosia...... contains significant quantities of Ambrosia seeds and remains unprocessed. Therefore, bird feed seems to play an important role in introducing Ambrosia to new, previously not infested areas....

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)

Uranium in surficial deposits and waters at Palmottu

International Nuclear Information System (INIS)

Ahonen, L.; Blomqvist, R.; Ervanne, H.; Suksi, J.; Jaakkola, T.

1994-01-01

Occurrence of uranium in surficial formations in the vicinity of an underground U deposit was studied. Several water samples from the Lake Palmottu and nearby springs, three lake sediment cores and three peat cores were collected for the study. Uranium concentrations in the water samples varied from 1.4 to 6.9 mBq/l, reflecting the average concentration of near-surface waters in Finland. In some samples, however, the 234 U/ 238 U activity ratio and water chemistry suggest a partial mixing with deeper groundwaters. In the lake sediments, uranium concentrations increases from 53 Bq/kg in surface layer to five fold in the bottom layers deposited 9000 years ago. In peat cores large variations in uranium concentrations can be observed: from tens of Bq/kg to over 20 kBq/kg of peat ash. The large variation also in the 234 U/ 238 U activity ratio, from 0.79 to l.91, tends to indicate uranium migration to the peat from more than one uranium source. (orig.) (19 refs., 5 figs., 1 tab.)

Advances in the exploration model for Athabasca unconformity uranium deposits

International Nuclear Information System (INIS)

Wheatley, K.; Murphy, J.; Leppin, M.; Cutts, C.; Climie, J.A.

1997-01-01

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

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

Science.gov (United States)

Albert (Bud) Mayfield; Martin MacKenzie; Philip G. Cannon; Steve Oak; Scott Horn; Jaesoon Hwang; Paul E. Kendra

2013-01-01

The redbay ambrosia beetle Xyleborus glabratus Eichhoff is a non-native vector of the pathogen that causes laurel wilt, a deadly disease of trees in the family Lauraceae in the southeastern U.S.A.Concern exists that X. glabratus and its fungal symbiont could be transported to the western U....

Canada: The largest uranium producer

International Nuclear Information System (INIS)

Lowell, A.F.

1985-01-01

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

Chemical ecology and lure development for redbay ambrosia beetle

Science.gov (United States)

The exotic redbay ambrosia beetle, Xyleborus glabratus Eichhoff, has become a serious invasive pest in the U.S., currently established in nine southeastern states. Female beetles are the primary vectors of a pathogenic fungus (Raffaelea lauricola) that causes laurel wilt. This lethal vascular dise...

Surficial origin of North American pitchblende and related uranium deposits

International Nuclear Information System (INIS)

Langford, F.F.

1977-01-01

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

Summary on uranium in Canada, 1984

International Nuclear Information System (INIS)

Ruzicka, V.; LeCheminant, G.M.

1985-01-01

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

Chemical ecology of sudden oak death/ambrosia beetle interactions

Science.gov (United States)

Frances S. Ockels; Pierluigi Bonello; Brice McPherson; David L. Wood

2006-01-01

Coast live oaks, Quercus agrifolia, infected with Phytophthora ramorum in California produce a characteristic sequence of symptoms and signs. Ambrosia beetles consistently tunnel into the bark of bleeding cankers in naturally infected trees. In field monitoring conducted since 2000, every bleeding coast live oak that subsequently...

Uranium producers foresee new boom

International Nuclear Information System (INIS)

McIntyre, H.

1979-01-01

The status of uranium production in Canada is reviewed. Uranium resources in Saskatchewan and Ontario are described and the role of the Cluff Lake inquiry in securing a government decision in favour of further uranium development is mentioned. There have been other uranium strikes near Kelowna, British Columbia and in the Northwest Territories. Increasing uranium demand and favourable prices are making the development of northern resources economically attractive. In fact, all uranium currently produced has been committed to domestic and export contracts so that there is considerable room for expanding the production of uranium in Canada. (T.I.)

Anti-inflammatory activity of Ambrosia artemisiaefolia and Rhoeo spathacea.

Science.gov (United States)

Pérez G, R M

1996-09-01

Alcoholic extracts of the leaves of Ambrosia artemisiaefolia and Rhoeo spathacea have been investigated for anti-inflammatory activity using various experimental models of inflammation (croton oil ear oedema, carrageenan-induced edema, cotton pellet granuloma and formaldehyde induced arthritis) and the results compared with phenylbutazone and bethamethasone, standard anti-inflammatory drugs. These extracts at doses of 50, 100 and 150mg/kg of A. artemisiaefolia and R. spathacea, showed significant inhibition of acute oedema in rats and mice induced by the phlogistic agents, carrageenan and croton oil, in a dose-dependant manner. The ethanol extracts reduced cotton pellet granuloma and caused a statistically significant inhibitory effect on edema in the chronic model of formaldehyde arthritis in rats. Since Ambrosia artemisiaefolia and Rhoeo spathacea were found to be effective in both acute and chronic phases of inflammation they can be considered as general anti-inflammatory agents. Copyright © 1996 Gustav Fischer Verlag · Stuttgart · Jena · New York. Published by Elsevier GmbH.. All rights reserved.

Vertical Distribution and Daily Flight Periodicity of Ambrosia Beetles (Coleoptera: Curculionidae) in Florida Avocado Orchards Affected by Laurel Wilt

Science.gov (United States)

Ambrosia beetles have emerged as significant pests of avocado (Persea americana Miller) due to their association with pathogenic fungal symbionts, most notably Raffaelea lauricola, the causal agent of laurel wilt. We evaluated the interaction of ambrosia beetles with host avocado trees by documentin...

Cigar Lake, an original method for an exceptional deposit

International Nuclear Information System (INIS)

Caleix, C.

1997-01-01

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)

Engineering assessment of inactive uranium mill tailings. Vitro site, Salt Lake City, Utah

International Nuclear Information System (INIS)

1981-04-01

Ford, Bacon and Davis Utah Inc. has reevaluated the Vitro site in order to revise the April 1976 assessment of the problems resulting from the existence of radioactive uranium mill tailings at Salt Lake City, Utah. 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 the 1.9 million tons of tailings at the Vitro 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 and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites, and decontamination of the tailings site (Options II through IV). Cost estimates for the four options range from about $36,400,000 for stabilization in-place, to about $91,000,000 for disposal at a distance of about 85 mi. Three principal alternatives for the reprocessing of the Vitro 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 $200/lb by heap leach and $130/lb by conventional plant processes. Spot market price for uranium was $28.00 in November 1980. Therefore, reprocessing the tailings for uranium recovery appears to be economically unattractive at present

Biological aspects and life table of Uroleucon ambrosiae (Thomas, 1878) as a function of temperature

OpenAIRE

Auad Alexander Machado; Moraes Jair Campos de

2003-01-01

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 te...

Western Canada uranium perspective

International Nuclear Information System (INIS)

Lloyd, R.E.

1984-01-01

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 U 3 O 8 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.)

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

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)

Reynolds, R.L.; Fishman, N.S.; Scott, J.H.; Hudson, M.R.

1986-01-01

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

Invasive Asian Fusarium – Euwallacea ambrosia beetle mutualists pose a serious threat to forests, urban landscapes and the avocado industry

Science.gov (United States)

Several species of the ambrosia beetle Euwallacea (Coleoptera: Curculionidae: Scolytinae) cultivate Ambrosia Fusarium Clade (AFC) species in their galleries as a source of food. Like all other scolytine beetles in the tribe Xyleborini, Euwallacea are thought to be obligate mutualists with their fung...

Uranium peroxide precipitate drying temperature relationships

Energy Technology Data Exchange (ETDEWEB)

Rodgers, C.; Dyck, B., E-mail: chick_rodgers@cameco.com [Cameco Corp., Saskatoon, SK (Canada)

2010-07-01

Cameco Corporation is in the process of revitalizing the mill at its Key Lake operation in northern Saskatchewan. The current Key Lake process employs ammonia stripping and ammonia precipitation. As part of the revitalization, the company is considering installing strong acid stripping in solvent extraction as used at its Rabbit Lake operation. This change would lead to using hydrogen peroxide for uranium precipitation. As part of the process evaluation, tests were carried out to study how changes in the temperature of an indirect fired dryer affected the properties of uranium peroxide [yellowcake] precipitate. This paper discusses the results of the test work, including the relationships between drying temperature and the following: (author)

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

International Nuclear Information System (INIS)

Francis, A.J.; Joshi-Tope, G.; Gillow, J.B.; Dodge, C.J.

1994-03-01

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

Responding to non-technical challenges in the uranium mining industry

International Nuclear Information System (INIS)

Shpyth, A.

1997-01-01

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% U 3 O 8 ), 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

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

International Nuclear Information System (INIS)

Dixit, Aabha

2016-01-01

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

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

International Nuclear Information System (INIS)

Dixit, Aabha

2016-01-01

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.

Current approaches to geochemical reconnaissance for uranium in the Canadian Shield

International Nuclear Information System (INIS)

Cameron, E.M.; Hornbrook, E.H.W.

1976-01-01

Wide-interval geochemical reconnaissance is currently being carried out over large areas of the Canadian Shield by the Geological Survey of Canada. This work is in support of the federal-provincial Uranium Reconnaissance Program. The paper reviews the methodology employed for this reconnaissance to outline areas of enhanced potential for uranium and other mineral commodities. The generally low relief of the Shield virtually restricts wide-interval reconnaissance to the mobile elements that can travel some distance in solution. The high mobility of uranium, particularly in waters of neutral pH, makes it one of the most suitable types of mineralization for detection. For much of the Shield the most appropriate sampling media are lake sediments and lake waters. Centre-lake sediments are homogeneous, and are readily and economically collected utilizing helicopter support. They provide a good response for uranium and a variety of other indicator elements. Waters collected at the same sample sites are a useful supplement in the search for uranium mineralization, particularly in carbonate terrain. However, because of the very low content of uranium in many Shield waters, they present as yet unresolved problems of analysis and storage. The influence of organic material, iron and manganese on the uranium content of lake sediments are examined. Their scavenging influence has been found to be significant only at their lower concentration levels, particularly for organic matter and iron. For the majority of centre-lake samples the effect is negligible. The choice of sample interval is related to total survey costs, to speed of coverage, and to ability to detect uranium and other types of mineralization. For current G.S.C. programs a sample density of one per five square mile appears optimal. The results are presented as l:250,000 symbol maps that are prepared largely by computer, and as 1:1,000,000 contoured compilation maps. (author)

Resting cysts of freshwater dinoflagellates in southeastern Georgian Bay (Lake Huron) as proxies of cultural eutrophication

DEFF Research Database (Denmark)

McCarthy, Francine M.G.; Mertens, Kenneth Neil; Ellegaard, Marianne

2011-01-01

conditions, comprise 60–74% of the cysts identified in Ambrosia (ragweed)-rich sediments in the upper 20 cm of a gravity core taken from Honey Harbour. Euro-Canadian settlement and land-clearing that began in the Midland-Penetanguishene region around A.D. 1840 are evident in the increase in Ambrosia (ragweed...... contained between ~ 750 and 8500 cysts/cm3. However, winnowing by bottom currents and high concentrations of dissolved oxygen adversely impact the dinoflagellate cyst record on the lakebed, and cyst concentrations in easily remobilized muds on bathymetric highs were core changes......-Canadian settlement, when cyst flux was an order of magnitude lower. This is consistent with the restriction of this species to relatively warm, oligotrophic to mesotrophic lakes in North America. An earlier increase in P. willei at the expense of P. wisconsinense in the core from Honey Harbour within pollen zone 3 d...

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

International Nuclear Information System (INIS)

Robertson, R.

1986-01-01

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

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

International Nuclear Information System (INIS)

1977-08-01

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

Radioactivity levels in surface water of lakes around Izmir / Turkey

International Nuclear Information System (INIS)

Doyurum, S.; Turkozu, D. A.; Aslani, M. A. A.; Aytas, S.; Eral, M.; Kaygun, A. K.

2006-01-01

Radioactivity presents in surface continental waters is mainly due to the presence of radioactive elements in the earth's crust, other artificial radionuclides have appeared due to such human activities as nuclear power plants, nuclear weapons testing and manufacture and use of radioactive sources It is well known that natural radionuclides can be effective as tracers for the different processes controlling the distribution of elements among dissolved and particulate phases in aquatic systems. The detection of high radionuclide concentrations was proposed as a public health problem in several areas and consequently studies into the risks of radionuclides were started in the 2000s. Especially, these radioactive substances in groundwater are an unwanted and involuntary risk factor from natural sources, not artificial sources. These radioactive substances include uranium, radon found in uranium series, and other radioactive substances such as radium and gross alpha. Uranium present in rock, soil, and natural materials, and is found in small quantities in air, water, and food that people always contact. In this project, lake water samples were collected from three lakes around Izmir-Turkey. In surface lake water samples, pH, mV and conductivity values were measured and alkaline content was determined titrimetrically. The uranium concentrations in the lake water samples were measured using uranium analyzer. The radioactivity concentrations related to gross radium isotopes, gross-? and gross-? activities in the surface lake water were determined. The correlation among some parameters for water samples and concentrations of uranium, activity concentration of gross radium isotopes, gross alpha and gross beta radioactivity are also discussed

Uranium Mill Tailings Remedial Action Project Annual Environmental Monitoring Report calendar year 1992: Volume 1

International Nuclear Information System (INIS)

1993-01-01

This report describes environmental monitoring and compliance at eight UMTRA sites where remedial action was underway during 1992 and at the ten sites that were complete at the end of 1992. Volume I contains information for Ambrosia Lake, NM; Cannonsburg/Burrell, PA; Durango, CO; Falls City, TX; Grand Junction, CO; Green River, UT; and Gunnison, CO. Each site report contains a site description, compliance summary, environmental program information, environmental radiological and non-radiological program information, water resources protection, and quality assurance information

Uranium Mill Tailings Remedial Action Project Annual Environmental Monitoring Report calendar year 1992: Volume 1

Energy Technology Data Exchange (ETDEWEB)

None

1993-12-31

This report describes environmental monitoring and compliance at eight UMTRA sites where remedial action was underway during 1992 and at the ten sites that were complete at the end of 1992. Volume I contains information for Ambrosia Lake, NM; Cannonsburg/Burrell, PA; Durango, CO; Falls City, TX; Grand Junction, CO; Green River, UT; and Gunnison, CO. Each site report contains a site description, compliance summary, environmental program information, environmental radiological and non-radiological program information, water resources protection, and quality assurance information.

The Key Lake project

International Nuclear Information System (INIS)

1991-01-01

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

Saskatchewan resources. [including uranium

Energy Technology Data Exchange (ETDEWEB)

1979-09-01

The production of chemicals and minerals for the chemical industry in Saskatchewan are featured, with some discussion of resource taxation. The commodities mentioned include potash, fatty amines, uranium, heavy oil, sodium sulfate, chlorine, sodium hydroxide, sodium chlorate and bentonite. Following the successful outcome of the Cluff Lake inquiry, the uranium industry is booming. Some developments and production figures for Gulf Minerals, Amok, Cenex and Eldorado are mentioned.

Partnerships Between Ambrosia Beetles and Fungi: Lineage-Specific Promiscuity Among Vectors of the Laurel Wilt Pathogen, Raffaelea lauricola.

Science.gov (United States)

Saucedo-Carabez, J R; Ploetz, Randy C; Konkol, J L; Carrillo, D; Gazis, R

2018-04-20

Nutritional mutualisms that ambrosia beetles have with fungi are poorly understood. Although these interactions were initially thought to be specific associations with a primary symbiont, there is increasing evidence that some of these fungi are associated with, and move among, multiple beetle partners. We examined culturable fungi recovered from mycangia of ambrosia beetles associated with trees of Persea humilis (silk bay, one site) and P. americana (avocado, six commercial orchards) that were affected by laurel wilt, an invasive disease caused by a symbiont, Raffaelea lauricola, of an Asian ambrosia beetle, Xyleborus glabratus. Fungi were isolated from 20 adult females of X. glabratus from silk bay and 70 each of Xyleborus affinis, Xyleborus bispinatus, Xyleborus volvulus, Xyleborinus saxesenii, and Xylosandrus crassiusculus from avocado. With partial sequences of ribosomal (LSU and SSU) and nuclear (β-tubulin) genes, one to several operational taxonomic units (OTUs) of fungi were identified in assayed individuals. Distinct populations of fungi were recovered from each of the examined beetle species. Raffaelea lauricola was present in all beetles except X. saxesenii and X. crassiusculus, and Raffaelea spp. predominated in Xyleborus spp. Raffaelea arxii, R. subalba, and R. subfusca were present in more than a single species of Xyleborus, and R. arxii was the most abundant symbiont in both X. affinis and X. volvulus. Raffaelea aguacate was detected for the first time in an ambrosia beetle (X. bispinatus). Yeasts (Ascomycota, Saccharomycotina) were found consistently in the mycangia of the examined beetles, and distinct, putatively co-adapted populations of these fungi were associated with each beetle species. Greater understandings are needed for how mycangia in ambrosia beetles interact with fungi, including yeasts which play currently underresearched roles in these insects.

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

International Nuclear Information System (INIS)

1983-06-01

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

Modelling of the underwater disposal of uranium mine tailings in Elliot Lake

International Nuclear Information System (INIS)

Halbert, B.E.; Scharer, J.M.; Chakravatti, J.L.; Barnes, E.

1982-01-01

Underwater disposal of uranium mine tailings from the Elliot Lake area operations offers potential advantages in controlling radon gas release, emission of airborne particulate matter, and acid production from pyrites in the tailings. In addition, the proximity of the three active properties, one owned by Denison Mines Limited and two by Rio Algom Limited, to a large deep lake has spurred interest in the concept. It has been estimated that the placement of approximately 150 million tonnes of tailings from future planned production would occupy less than 20% of the lake volume. To assess the applicability of the underwater tailings disposal concept, a multi-stage study was developed in conjunction with the regulatory agencies. The most important facet identified for investigation during the first-stage investigations was an assessment of the effects of underwater disposal on water quality in the Serpent River Basin watershed. To simulate the effects of underwater disposal, a computer simulation routine was developed and integrated with a water quality model previously developed for the Basin which predicts levels of total dissolved solids, ammonia, dissolved radium-226 and pH. The underwater disposal model component reflects the effects of direct input of tailings into the hypolimnion, the chemical/biological transformation of dissolved constituents in the water column, the reactions of pyritic tailings deposited on the bottom, and the flux of dissolved constituents from the tailings into the water column. To establish site-specific values for the underwater disposal model, field and laboratory experiments were utilized to evaluate rates of pyrite and ammonia oxidation, and pH-alkalinity relationships. The results of these studies and their use in the water quality model are discussed. In addition, the results of two model run simulations are presented. (author)

Overview of the environmental impact assessment for the proposed expansion of the Elliot Lake Ontario uranium mines

International Nuclear Information System (INIS)

Gorber, D.M.; Graham, R.G.; Ibbotson, B.G.

1978-01-01

As a result of the resurgence in the demand for uranium, Denison Mines Limited and Rio Algom Limited began preparations, in 1973 and 1974 respectively, for expansion of their facilities at Elliot Lake, Ontario. These programmes involved not only the expansion of facilities currently in operation in the area, but also the rehabilitation of non-operating properties that were previously used during the 1960's. This paper reviews the methodology employed during the environmental assessment study of the proposed expansion and highlights the long and short-term strategies recommended

Hinkler Well - Centipede uranium deposits

International Nuclear Information System (INIS)

Crabb, D.; Dudley, R.; Mann, A.W.

1984-01-01

The Hinkler Well - Centipede deposits are near the northeastern margin of the Archean Yilgarn Block on a drainage system entering Lake Way. Basement rocks are granitoids and greenstones. The rocks are deeply weathered and overlain by alluvism. Granitoids, the probable uranium source, currently contain up to 25 ppm uranium, in spite of the weathering. The host calcrete body is 33 km long and 2 km wide. Uranium up to 1000 ppm occurs in carnotite over a 15 km by 2.5 km area. (author)

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

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

Science.gov (United States)

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

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)

Albert E. Mayfield; James L. Hanula

2012-01-01

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...

Petrology of the Fort Smith - Great Slave Lake radiometric high near Pilot Lake, N.W.T

International Nuclear Information System (INIS)

Burwash, R.A.; Cape, D.F.

1981-01-01

Near Pilot Lake, the east boundary of the Fort Smith - Great Slave Lake radiometric high coincides with the contact of a well-foliated, porphyroblastic microcline-plagioclase-quartz-garnet-biotite gneiss (Pilot Lake Gneiss) with a hybrid assemblage of quartzite, mica schist, garnet-cordierite gneiss, and minor amphibolite (Variable Paragneiss). Anomalously high concentrations of uranium and thorium are associated with mafic-rich, lenticular bodies with a mineral assemblage biotite + monazite + zircon + ilmenite + hematite +- plagioclase +- quartz, within both the Variable Paragneiss and the Pilot Lake Gneiss. Corundum and spinel occur in the mafic lenses and sillimanite, kyanite, and hypersthene in other inclusions of the Pilot Lake Gneiss. The ilmenite-magnetite--monazite-zircon-apatite assemblage is interpreted as a 'black sand' concentration in a clastic sedimentary sequence subsequently metamorphosed by a regional granulite facies event. A granite pluton intruded during the same orogenic cycle assimilated the clastic metasedimentary rocks containing black sand interlayers, becoming enriched in thorium from the monazite. A second metamorphic event at lower P-T conditions, accompanied by strong cataclasis, developed the texture of the Pilot Lake Gneiss as now observed. Shearing within the gneiss locally concentrated hematite + quartz + uranium. Regional tectonic extrapolations suggest that the pyroxene granulite event was Kenoran and the later amphibolite event Hudsonian. (author)

Distribution and behavior of radionuclides and stable elements in Lake Obuchi

International Nuclear Information System (INIS)

Ueda, Shinji; Hasegawa, Hidenao; Takaku, Yuichi; Kondo, Kunio; Inaba, Jiro

2001-01-01

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 238 U 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 238 U 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 238 U/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 O 2 accompanied by the decomposition of the organic matter in sediment caused chemical reduction in the bottom layer. (author)

Ontario's uranium mining industry

International Nuclear Information System (INIS)

Runnalls, O.J.C.

1981-01-01

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

Ambrosia beetle communities in forest and agriculture ecosystems with laurel wilt disease

Science.gov (United States)

The invasive redbay ambrosia beetle, Xyleborus glabratus, 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 trees in the family Lauraceae. Redbay ambro...

Bacterial community composition in the water column of a lake formed by a former uranium open pit mine.

Science.gov (United States)

Edberg, Frida; Andersson, Anders F; Holmström, Sara J M

2012-11-01

Mining of pyrite minerals is a major environmental issue involving both biological and geochemical processes. Here we present a study of an artificial lake of a former uranium open pit mine with the aim to connect the chemistry and bacterial community composition (454-pyrosequencing of 16S rRNA genes) in the stratified water column. A shift in the water chemistry from oxic conditions in the epilimnion to anoxic, alkaline, and metal and sulfide-rich conditions in the hypolimnion was corresponded by a strong shift in the bacterial community, with few shared operational taxonomic units (OTU) between the water layers. The epilimnetic bacterial community of the lake (~20 years old) showed similarities to other temperate freshwater lakes, while the hypolimnetic bacterial community showed similarity to extreme chemical environments. The epilimnetic bacterial community had dominance of Actinobacteria and Betaproteobacteria. The hypolimnion displayed a higher bacterial diversity and was dominated by the phototrophic green sulphur bacterium of the genus Chlorobium (ca. 40 % of the total community). Deltaproteobacteria were only represented in the hypolimnion and the most abundant OTUs were affiliated with ferric iron and sulfate reducers of the genus Geobacter and Desulfobulbus, respectively. The chemistry is clearly controlling, especially the hypolimnetic, bacterial community but the community composition also indicates that the bacteria are involved in metal cycling in the lake.

Disjunct population of redbay ambrosia beetle and laurel wilt disease discovered in Mississippi

Science.gov (United States)

J.J. Riggins; M. Hughes; J.A. Smith; R. Chapin

2011-01-01

Laurel wilt is an aggressive, non-native vascular wilt disease of redbay trees (Persea borbonia), sassafras (Sassafras albidum), and other plants within the Lauraceae family. The laurel wilt pathogen, (Raffaelea lauricola), is vectored by the redbay ambrosia beetle (Xyleborus glabratus), which...

Aqueous-chlorine leaching of typical Canadian uranium ores

International Nuclear Information System (INIS)

Haque, K.E.

1982-01-01

Laboratory-scale aqueous-chlorine leaches were conducted on quartz-pebble conglomerates, pegmatite and vein-type ores. Optimum leach temperatures, pulp density and retention times were determined. Uranium extraction of 98 per cent was obtained from the Elliot Lake, Madawaska Mines of Bancroft and Rabbit Lake ores, 96 per cent from the Key Lake ore and 86 per cent from the Agnew Lake ore. However, tailings containing 15-20 pCi g -1 of radium-226 were obtained only from the Elliot Lake and Agnew lake quartz-pebble conglomerates and Bancroft pegmatite-type ores by second-stage leaches with HCl. The second-stage leach results indicate that multistage (3 or 4) acid-chloride or salt-chloride leaches might be effective to obtain tailings containing 15-20 pCi 226 Ra g -1 from the high-grade vein-type ores. Comparative reagent-cost estimates show that the sulphuric-acid leach process is far less expensive than aqueous chlorine leaching. Nevertheless, only the aqueous chlorine and acid-chloride leaches in stages are effective in producing tailings containing 15-20 pCi 226 Ra g -1 from the typical Canadian uranium ores. (Auth.)

Uranium and thorium deposits of Northern Ontario

International Nuclear Information System (INIS)

Robertson, J.A.; Gould, K.L.

1983-01-01

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

Uranium tailings reference materials

International Nuclear Information System (INIS)

Smith, C.W.; Steger, H.F.; Bowman, W.S.

1984-01-01

Samples of uranium tailings from Bancroft and Elliot Lake, Ontario, and from Beaverlodge and Rabbit Lake, Saskatchewan, have been prepared as compositional reference materials at the request of the National Uranium Tailings Research Program. The four samples, UTS-1 to UTS-4, were ground to minus 104 μm, each mixed in one lot and bottled in 200-g units for UTS-1 to UTS-3 and in 100-g units for UTS-4. The materials were tested for homogeneity with respect to uranium by neutron activation analysis and to iron by an acid-decomposition atomic absorption procedure. In a free choice analytical program, 18 laboratories contributed results for one or more of total iron, titanium, aluminum, calcium, barium, uranium, thorium, total sulphur, and sulphate for all four samples, and for nickel and arsenic in UTS-4 only. Based on a statistical analysis of the data, recommended values were assigned to all elements/constituents, except for sulphate in UTS-3 and nickel in UTS-4. The radioactivity of thorium-230, radium-226, lead-210, and polonium-210 in UTS-1 to UTS-4 and of thorium-232, radium-228, and thorium-228 in UTS-1 and UTS-2 was determined in a radioanalytical program composed of eight laboratories. Recommended values for the radioactivities and associated parameters were calculated by a statistical treatment of the results

Influence of uranium mill tailings on tree growth at Elliot Lake

International Nuclear Information System (INIS)

Murray, D.R.

1978-01-01

A four-year study was carried out to determine the ability of coniferous trees to aid in the reclamation of uranium tailings at Elliot Lake. Five species were planted: white cedar, white spruce, jack pine, scotch pine and red pine. More than 570 bare-root, two-year-old seedlings were planted on bare tailings and in areas of established grasses. A further division was made between areas of coarse and fine tailings. Over-all survival and growth of the trees has been far below expectations based on previous experience with several varieties of grasses. The criteria for assessment have been per cent survival and yearly growth as determined by plant height. Pine was superior, with 68% survival when planted in bare coarse tailings, 45% for vegetated coarse tailings and 34% for vegetated fine tailings. Cedar had the worst survival rates at 49%, 14% and 7% respectively. No species survived on bare fine tailings. The survival and growth of the coniferous trees have been related to species, environmental conditions and tailings properties. (author)

Influence of uranium mill tailings on tree growth at Elliot Lake

International Nuclear Information System (INIS)

Murray, D.R.

1978-01-01

A four year study was carried out to determine the ability of coniferous trees to aid in the reclamation of uranium tailings at Elliot Lake. Five species were planted: white cedar, white spruce, jack pine, scotch pine and red pine. More than 570 bare-root, two-year-old seedlings were planted on bare tailings and in areas of established grasses. A further division was made between areas of coarse and fine tailings. Over-all survival and growth of the trees has been far below expectations based on previous experience with several varieties of grasses. The crieteria for assessment have been per cent survival and yearly growth as determined by plant height. Pine was superior, with 68% survival when planted in bare coarse tailings, 45% for vegetated coarse tailings and 34% for vegetated fine tailings. Cedar had the worst survival rates at 49%, 14% and 7% respectively. No species survived on bare fine tailings. The survival and growth of the coniferous trees have been related to species, environmental conditions and tailings properties. (auth)

Uranium production, acquisition and exploration in North America. Uran in Nordamerika: Produktion - Akquisition - Exploration

Energy Technology Data Exchange (ETDEWEB)

Akin, H; Kuchelka, R

1991-06-01

Uranerz Exploration and Mining Limited (UEM or Uranerz), the Canadian subsidiary of Uranerzbergbau GmbH, Bonn, has become a significant producer of uranium concentrates in the world during the last 20 years. The first step in this development was the acquisition of a large share in the former Rabbit Lake deposit and mill in 1970. Five years later UEM discovered the famous Key Lake deposit, containing the Gaertner and Deilmann orebodies, which today form the basis of the single largest and probably most economic uranium mine and mill complex in the world. Recently, the acquisition of a share in the 'new' Rabit Lake mill together with major adjacent uranium deposits at Collins Bay and Eagle Point has been concluded. In the United States, where there is less hope for large rich uranium deposits to be found, Uranerz has concentrated on the development of in situ leaching technology which enables low cost production from relatively low grade deposits. The latest exploration success in Canada was achieved in the McArthur River Joint Ventures by drilling an underground uranium deposit, which can be compared with Key Lake in grade and size. This will further improve the reserve base and ensure that Uranerz will maintain its position in a growing uranium market even after the turn of the century. (orig.).

Aspectos biológicos e tabela de vida de Uroleucon ambrosiae (Thomas) em função da temperatura

OpenAIRE

Auad, Alexander Machado; Moraes, Jair Campos de

2003-01-01

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 te...

The Key Lake project

International Nuclear Information System (INIS)

Glattes, G.

1985-01-01

Aspects of project financing for the share of the Canadian subsidiary of Uranerzbergbau-GmbH, Bonn, in the uranium mining and milling facility at Key Lake, Saskatchewan, by a Canadian bank syndicate. (orig.) [de

Chlorination of uranium ore for extraction of uranium, thorium and radium and for pyrite removal

International Nuclear Information System (INIS)

Skeaf, J.M.

1979-01-01

The high-temperature chlorination of uranium ore was investigated. The objective was to develop a process which is both economically viable and environmentally acceptable. Test work was directed toward obtaining high extractions of uranium, thorium and radium-226, as well as iron, sulphur and the rare earths, and consists of chlorinating samples of an Elliot Lake uranium ore at elevated temperatures and repulping the resulting calcine in dilute hydrochloric acid. The effect of temperature and chlorine throughput on the extraction of the various metals was investigated. The best conditions yielded extractions of uranium, iron and sulphur (all as chlorides) greater than 95 percent. Chlorine consumption varied between 6 and 16 percent by weight of the ore charge. (author)

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

Uranium production, exploration and mine development in Canada

International Nuclear Information System (INIS)

Vance, R. E

2006-01-01

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 60 0 C 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

Key Lake spill. Final report

International Nuclear Information System (INIS)

1984-03-01

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

Uranium in tertiary stream channels, Lake Frome area, South Australia

International Nuclear Information System (INIS)

Brunt, D.A.

1978-01-01

Uranium exploration over a wide area of the Southern Frome Embayment, South Australia, has defined a number of Lower Tertiary fluvial palacochannels incised in older rocks. The buried channels contain similar stratigraphic sequences of interbedded sand, silt, and clay, probably derived from the adjacent uranium-rich Olary Province. Uranium mineralization is pervasive within two major palacochannels, and four small uranium deposits have been found in the basal sands of these channel sequences, at the margins of extensive tongues of limonitic sand. A genetic model is proposed suggesting formation by a uraniferous geochemical cell which migrated down the stream gradient and concentrated uranium on its lateral margins adjacent to the channel bank

Unconventional uranium resources in China

International Nuclear Information System (INIS)

Qi Fucheng; Zhang Zilong; Li Zhixing; Wang Zhiming; He Zhongbo; Wang Wenquan

2011-01-01

Unconventional uranium resources in China mainly include black-rock series, peat, salt lake and evaporitic rocks. Among them, uraniferous black-rock series, uraniferous phosphorite and uranium-polymetallic phosphorite connected with black-rock series are important types for the sustainable support of uranium resources in China. Down-faulting and epocontinental rift in continental margin are the most important and beneficial ore-forming environment for unconventional uranium resources of black-rock series in China and produced a series of geochemistry combinations, such as, U-Cd, U-V-Mo, U-V-Re, U-V-Ni-Mo and U-V-Ni-Mo-Re-Tl. Unconventional uranium resources of black-rock series in China is related to uranium-rich marine black-rock series which are made up of hydrothermal sedimentary siliceous rocks, siliceous phospheorite and carbonaceous-siliceous-pelitic rock and settled in the continental margin down-faulting and epicontinental rift accompanied by submarine backwash and marine volcano eruption. Hydrothermal sedimentation or exhalation sedimentary is the mechanism to form unconventional uranium resources in black-rock series or large scale uranium-polymetallic mineralization in China. (authors)

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

International Nuclear Information System (INIS)

Skipperud, L.; Jørgensen, A.G.; Heier, L.S.; Salbu, B.; Rosseland, B.O.

2013-01-01

Polonium-210 in water and 210 Pb and 210 Po 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 210 Pb and 210 Po 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 210 Po was higher than for 210 Pb, and the accumulation of 210 Po was highest in the liver of C. auratus (3673 ± 434 Bq kg −1 ww). Although the average activity concentration of 210 Pb 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 210 Po into the liver, and that the distributions of 210 Po and 210 Pb in fish organs were different. The BCF (L/kg) for 210 Po in bone, liver and muscle clearly demonstrates high accumulation of 210 Po in C. auratus, especially in the liver. The average BCFs of liver, bone and muscle were >1.4 × 10 5 , >2.5 × 10 4 and >1.4 × 10 4 , respectively. All fish in the Pit Lake were found to be in the same trophic level, however, a linear correlation between log 210 Po in liver and δ 15 N could indicate biomagnification of 210 Po in liver of C. auratus. In regards to the recommended Annual Limit of Intake (ALI) for 210 Po, the concentration of 210 Po 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

Development and survival of Aulacorthum solani, Macrosiphum euphorbiae and Uroleucon ambrosiae at six temperatures

NARCIS (Netherlands)

Conti, de B.F.; Bueno, V.H.P.; Sampaio, M.V.; Lenteren, van J.C.

2011-01-01

Temperature is one of the most important factors in determining the survival and developmental rate of aphids. The aim of this study was to evaluate the developmental time and survival of the aphid species Aulacorthum solani (Kaltenbach), Macrosiphum euphorbiae (Thomas) and Uroleucon ambrosiae

Comparison of ambrosia beetle communities in two hosts 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...

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: 9.328, year: 2015

Effets de dix traitements sur la germination des akènes d'Ambrosia maritima L

Directory of Open Access Journals (Sweden)

Schafer, JL.

1989-01-01

Full Text Available Effects of ten treatments on the germination of Ambrosia maritima L. seeds. Stratification of Ambrosia maritima seeds at + 10°C for 7 days appeared to be the best practical method to break their embryonic dormancy with 80 % germination occuring 18 days following the treatment, compared to 17 % for the control. This experiment confirms the susceptibility of embryonic dormancy to low temperatures. Treatments with waterat + 80°C or concentrated H2S04 for 15 mn and mechanical treatments eliminating the inhibition effect of seed integuments also gave higher results (43 to 53 % germination rate. However, germination in the control group was significantly higher than in the group of seeds subjected to dry heat. Although the first results obtained on the field from these trials were satisfactory, further research is needed to confirm them.

Development and testing af a model for the supergene distribution of uranium and accompanying elements around a known uranium deposit associated with an alkaline intrusion

International Nuclear Information System (INIS)

Rose-Hansen, J.; Soerensen, H.

1983-01-01

The Ilimaussaq intrusion may be characterized as a geochemically abnormal region, since its rocks are strongly enriched in a number of rare elements, including elements which accompany uranium in deposits in other parts of the world. Examples are the rare earth metals, Nb, Ta, Be, Li, and metals as Cu, Pb, Zn, Mo and Sn. It was proposed to develop and test a model for the supergene distribution of uranium and accompanying elements around a known uranium deposit associated with an alkaline intrusion. The most promising results are those obtained by the PCA technique. For a more preliminary study of a region fjord and river sediments might be the sampling target. These sediments were found to be mixtures in which the proportion of material from the Ilimaussaq U-deposit could be evaluated by the PCA technique involving a distance function related to the loadings in the first principal dimen- sion of the elements characterizing the Ilimaussaq Intrusion. One of the major features of the material sampled in this study is the general high degree of preservation in the sub-arctic environment of the primary igneous mineralogy in the sediments, and in other areas, the structure of data should be investigated in order to test them in this respect. One obvious way is X-ray diffraction analysis. It was indicated that uranium is selectively absorbed on the organic material in lakes and is able to reflect the concentration of U in the lake waters, informing the ultimate potential of the drainage areas in question. It is however yet to be established whether the correlation of uranium and the organic material of the lake sediments actually reflects the long term U concentrations of the lake water. The use of the cluster analysis and discriminant analysis techniques proved to be of lesser value in this project. (author)

Uranium exploration and evaluation techniques

International Nuclear Information System (INIS)

Bowie, S.H.U.

1977-01-01

Ground, carborne and airborne surveys for uranium commenced with GM-counters and developed to total-count scintillation counters which have subsequently been replaced to some extent by gamma spectrometers. Stabilisation of the last mentioned is important and has only been achieved recently. Hydrogeochemistry has been revitalised by the introduction of neutron activation analysis and has considerable promise of success in the discovery of surface and near-surface uranium deposits. Soil, stream sediment and lake sediment analyses also have potential particularly in follow-up surveys. One of the most encouraging methods of detecting relatively deeply buried uranium ore bodies is by measuring the radon content of air retained in soil or sub-soil; also that dissolved in stream or lake water. Helium, particularly 4 He, which is also a decay product of uranium but which has an infinite half-life could be measured along with radon. Theoretically this could not only give additional information on buried ore bodies, but on the depth of burial. Another possible technique for use in the detection of buried ore bodies is that of measuring the increased heat flow at surface which, in favourable circumstatnces, should be associated with significant uranium occurrences. Measurement of heat flow could either be by surface thermal sensors or by thermal infra-red scanning techniques from aircraft. For the purposes of preliminary surveys of large areas, airborne geochemical techniques offer considerable scope. Possibilities include the measurement of 222 Rn in the atmosphere. Alternatively, one or more of the decay products of radon could be measured. These are 210 Pb, 210 Bi and 210 Po. It is concluded that there is ample evidence to suggest that the more widespread application of known exploration methods, together with new techniques that can already be envisaged, will result in important new discoveries of uranium reserves

Jarosite formation in the uranium processing circuit of Denison Mines Limited, Elliot Lake, Ontario

International Nuclear Information System (INIS)

Dutrizac, J.E.

1985-04-01

Jarosite precipitation occurs in several parts of the uranium processing circuit of Denison Mines Limited, Elliot Lake, Ontario. Extensive precipitation of jarosite takes place in the filter cloth and on the drum face of the secondary drum filters, and this precipitation causes severe operating difficulties. Precipitation of jarosite is also observed in the ion exchange beads, but it is not known whether the jarosite is responsible for the observed decrease in resin efficiency. The resin beads are also rimmed with significant quantities of silica, lead, phosphate, sulphate, etc. which could be responsible for the fouling of the resin. In every instance, potassium jarosite, containing only minor amounts of sodium or ammonium, was the observed species; the potassium likely originates from the acid leaching of muscovite in the ore. Potential methods of avoiding the jarosite problem are discussed, but these may not be compatible with the overall process requirements

Uranium and radium in Finnsjoen - an experimental approach for calculation of transfer factors

International Nuclear Information System (INIS)

Evans, S.; Bergman, R.

1981-01-01

The radiological safety studies for underground disposal of HLW show that the future individual and collective doses to an important extent may originate from groundwater borne radium and uranium which reach the biosphere. Indications that the dispersion rates presently used give rise to overestimations of calculated doses justified an investigation for more realistic turnover rates of radium and uranium than those which now are in use. Within one of the sites selected for testing, the area around lake Finnsjoen, a small number of environmental samples were collected and analyzed with respect to radium and uranium and the new transfer coefficients between soil and lake water were derived. The dose rates obtained with the new transfer factors show a close agreement for radium and a slight increase for uranium compared with earlier calculations. (Auth.)

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.

Flotation of uranium from uranium ores in Canada. Part 1

International Nuclear Information System (INIS)

Muthuswami, S.V.; Vigayan, S.; Woods, D.R.; Banerjee, S.

1983-01-01

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

Cluff Lake mill operations - a historical review

International Nuclear Information System (INIS)

Schnell, H.A.; Doell, E.; Corpus, E.

2000-01-01

The Cluff Lake operation started uranium production in 1980 and has produced over 50 million pounds of uranium since that time. The plant started with high grade ore (+30% U) processing and went through a series of modifications to its present operating status: Phase 1 - High-grade ore (+30% U) processing with acid leach and iron cake precipitation followed by direct yellowcake precipitation. Lower grade ore was concentrated in a gravity circuit to +30% U; Phase 1 1/2 - Reprocessing Phase 1 gravity tailings (+1% U) in an acid leach circuit with solvent extraction purification prior to yellowcake precipitation; Reprocessing of the Phase 1 leach tails (58 g/t Au) to recover gold in a Cyanide/CIP circuit followed by additional uranium recovery, and destruction and recycle of cyanide by volatilization; and Phase 2 - Treatment of the lower grade ore (0.5 to 1% U) at an increased tonnage with an acid leach, CCD, SX circuit as it is found in the existing plant. This paper will review the various processing circuits used during the phases of the Cluff Lake Mill from first uranium production to the present operation. (author)

Residue age and tree attractiveness influence efficacy of insecticide treatments against ambrosia beetles (Coleoptera: Curculionidae)

Science.gov (United States)

Management of ambrosia beetles in ornamental nurseries relies, in part, on treatments of insecticides to prevent beetles from boring into trees emitting stress-induced ethanol. However, data on residual efficacy of commonly used pyrethroid insecticides is warranted to gauge the duration that trees ...

The uranium ore deposits of the pine creek geosyncline in North Territory, Australia

International Nuclear Information System (INIS)

Kneuper, G.K.; Clasen, D.

1980-01-01

The geological history of the Pine Creek geosyncline is reviewed, and recent research findings and model assumption on the formation of uranium ore deposits are presented. The geological similarities between the Alligator River uranium ore district and the Athabasca Lake district in Saskatchewan, Canada, are pointed out. Present geographic and climatic differences between these two uranium districts and the consequences of these differences for uranium exploration are discussed. The uranium mining activities planned in Australia are illustrated by the example of the Ranger uranium deposit. (orig.) [de

The technology of uranium extraction from the brine with high chlorine-ion content

International Nuclear Information System (INIS)

Khakimov, N.; Nazarov, Kh.M.; Mirsaidov, I.U.; Negmatov, Sh.I.; Barotov, B.B.

2010-01-01

Present article is devoted to technology of uranium extraction from the brine with high chlorine-ion content. The research results on uranium extraction from the brine of Sasik-Kul Lake by means of sorption method were considered. The chemical composition of salt was determined. The process of uranium sorption was described and analyzed. The technology of uranium extraction from the brine with high chlorine-ion content was proposed.

Western states uranium resource survey

International Nuclear Information System (INIS)

Tinney, J.F.

1977-01-01

ERDA's National Uranium Resource Evaluation (NURE) program was established to provide a comprehensive description of uranium resources in the United States. To carry out this task, ERDA has contracted with various facilities, including universities, private companies, and state agencies, to undertake projects such as airborne radiometric surveys, geological and geochemical studies, and the development of advanced geophysical technology. LLL is one of four ERDA laboratories systematically studying uranium distribution in surface water, groundwater, and lake and stream sediments. We are specifically responsible for surveying seven western states. This past year we have designed and installed facilities for delayed-neutron counting and neutron-activation analysis, completed seven orientation surveys, and analyzed several thousand field samples. Full-scale reconnaissance surveys began last fall

Attraction of ambrosia and bark beetles to coast live oaks infected by Phytophthora ramorum

Science.gov (United States)

Brice A. McPherson; Nadir Erbilgin; David L. Wood; Pavel Svihra; Andrew J. Storer; Richard B. Standiford

2008-01-01

Sudden oak death, caused by Phytophthora ramorum (Werres, de Cock & Man in?t Veld), has killed thousands of oaks (Quercus spp.) in coastal California forests since the mid-1990s. Bark and ambrosia beetles that normally colonize dead or severely weakened trees selectively tunnel into the bleeding cankers that are the first...

Fungus cultivation by ambrosia beetles: Behavior and laboratory breeding success in three Xyleborine species

Science.gov (United States)

Peter Biedermann; Kier Klepzig; Taborsky Michael

2009-01-01

Fungus cultivation by ambrosia beetles is one of the four independently evolved cases of agriculture known in animals. Such cultivation is most advanced in the highly social subtribe Xyleborina (Scolytinae), which is characterized by haplodiploidy and extreme levels of inbreeding. Despite their ubiquity in forests worldwide, the behavior of these beetles remains poorly...

Design and results of the Mariano Lake-Lake Valley drilling project, Northwestern New Mexico

International Nuclear Information System (INIS)

Kirk, A.R.; Huffman, A.C. Jr.; Zech, R.S.

1986-01-01

This drilling project included 12 holes along a north-south-trending line from Mariano Lake to Lake Valley, New Mexico, near the southern margin of the San Juan basin. Of a total 33,075 ft (10,088m) drilled, 4,550 ft (1,388m) were cored in the stratigraphic interval that included the basal part of the Dakota Sandstone, the Brushy Basin and Westwater Canyon Members of the Morrison Formation, and the upper part of the Recapture Member of the Morrison Formation. The project objectives were (1) to provide cores and geophysical logs for study of the sedimentology, petrography, geochemistry, and mineralization in the uranium-bearing Westwater Canyon Member; (2) to provide control for a detailed seismic study of Morrison stratigraphy and basement structures; (3) to define and correlate the stratigraphy of Cretaceous coal-bearing units; (4) to supply background data for studies of ground-water flow pattern and ground-water quality; and (5) to provide data to aid resource assessment or uranium and coal. The project design included selection of (1) drill-hole locations to cross known ore and depositional trends in the Morrison Formation; (2) a coring interval to include the uranium-bearing unit and adjacent units; geophysical logs for lithologic correlations, quantitative evaluation of uranium mineralization, qualitative detection of coal beds, preparation of synthetic seismograms, and magnetic susceptibility studies of alteration in the Morrison; and (3) a high-salinity mud program to enhance core recovery

Stratigraphy and uranium potential of early proterozoic metasedimentary rocks in the Medicine Bow Mountains, Wyoming

International Nuclear Information System (INIS)

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

1979-01-01

The Medicine Bow Mountains of southeastern Wyoming contain an eight mile (13 km) thick section of Early Proterozoic (2500 to 1700 My b.p.) metasedimentary rocks which is subdivided into three successions: the Phantom Lake Metamorphic Suite (oldest), Deep Lake Group, and Libby Creek Group. The most promising units are the basal conglomerate of the upper Phantom Lake Suite, which appears to unconformably overlie metavolcanics of the lower Phantom Lake Suite, and the Magnolia Formation, which unconformably overlies the upper Phantom Lake Suite. Outcrops of the former have yielded assays of up to 141 ppM U and 916 ppM Th, with no appreciable gold. Outcrops of the Magnolia Formation have yielded up to 8.4 ppM U and 38 ppM Th. Several factors indicate that these units deserve further study. First, the lithologies of the radioactive and nonradioactive units are remarkably similar to those found in known uranium fossil-placers. Second, the paleogeography was favorable for placer accumulation if the conglomerates are fluvial sediments in an epicontinental clastic succession which was deposited during several transgressive-regressive cycles, as interpreted to be, Third, the age of the conglomerates may be similar to the age of other known uranium placers-i.e., more than 2000 My b.p. And fourth, geological and geochemical studies indicate that both uranium and pyrite have been strongly leached from outcrops and that subsurface rocks contain more uranium than surface rocks do

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)

Fayek, M.; Harrison, T.M.; Grove, M.; Coath, C.D.

2000-01-01

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

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

International Nuclear Information System (INIS)

Dave, N.K.; Lim, T.P.; Cloutier, N.R.

1984-02-01

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

Simple and Efficient Trap for Bark and Ambrosia Beetles (Coleoptera: Curculionidae) to Facilitate Invasive Species Monitoring and Citizen Involvement.

Science.gov (United States)

Steininger, M S; Hulcr, J; Šigut, M; Lucky, A

2015-06-01

Bark and ambrosia beetles (Coleoptera: Curculionidae: Scolytinae & Platypodinae) are among the most damaging forest pests worldwide, and monitoring is essential to damage prevention. Unfortunately, traps and attractants that are currently used are costly, and agencies rely on limited field personnel for deployment. The situation can be greatly aided by 1) the development of cost-effective trapping techniques, and 2) distribution of the effort through the Citizen Science approach. The goal of this study was to test a simple, effective trap that can be made and deployed by anyone interested in collecting bark and ambrosia beetles. Three trap types made from 2-liter soda bottles and, separately, four attractants were compared. Simple, one-window traps performed comparably at capturing species in traps painted or with multiple windows. A comparison of attractants in two-window traps found that 95% ethanol attracted the highest number of species but that Purell hand sanitizer (70% ethanol) and then Germ-X hand sanitizer (63% ethanol) were also effective. A perforated zip-top plastic bag containing Purell hanging over a trap filled with automobile antifreeze attracted the fewest species and individual specimens. Overall, >4,500 bark and ambrosia beetles, including 30 species were captured, representing a third of the regional species diversity. More than three quarters of the specimens were nonnative, representing nearly half of the known regional exotic species. These results suggest that simple one-window soda bottle traps baited with ethanol-based hand sanitizer will be effective and inexpensive tools for large-scale monitoring of bark and ambrosia beetles. © The Authors 2015. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

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

International Nuclear Information System (INIS)

Puyana Monica; Petrichtcheva, Natalia; Morales, Alicia; Duque Carmenza

2002-01-01

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

Vertical distribution and daily flight periodicity of ambrosia beetles associated with laurel wilt affected avocado orchards.

Science.gov (United States)

Recently, ambrosia beetles have emerged as significant pests of avocado (Persea americana Mill.; Lauraceae) due to their association with fungal pathogens, in particular, the causal agent of laurel wilt disease, Raffaelea lauricola. The objective of this study was to provide insights into the intera...

Drill site selection process using geophysical (seismic, EM, magnetic) surveys and regional geochemical uranium deposit vectors within the Keefe Lake Uranium Property and its vicinity – Athabasca Basin, Saskatchewan, Canada

International Nuclear Information System (INIS)

Hajnal, Z.; Pandit, B.; Annesley, I.; Takacs, E.

2014-01-01

This study was initiated at the request of Athabasca Uranium Inc. of Vancouver, Canada. The area of investigation is around 4000 km"2 and includes the Keefe Lake (KL) property of the Company, located at the southeastern flank of the Athabasca Basin in Northern Saskatchewan. The intention of the program was multi-fold: to establish trends of regional uranium mineralization vectors, and incorporate these findings into the multidimensional integrated analysis of the currently available KL data set with an aim of providing an advanced priority ranking of drill hole selection process for the upcoming drilling programs. The information adapted for this investigation includes data from 450 boreholes, as well as drilling results of a recent KL prospect; data obtained from 114 Assessment Reports of the Saskatchewan Mineral Assessment Data Base (SMAD), and the analyses of 4 highresolution 2D seismic profiles within the claims of Athabasca Uranium Inc. To establish more effective spatial perspectives, the results of the regional lithology study (investigating alteration, graphitic, structural, pelitic, and pegmatitic features) were displayed along with the EM conductors, whereas basement lithology and faults were obtained from the Geological Atlas of Saskatchewan (southeastern segment of the Athabasca Basin). The regional investigation also included a study of the depth variations of the unconformity (UC), spatial vectors in geochemistry of the indicative path finder elements (U, Co, Cu, Ni, Pb, Zn, As, and B), and also the clay mineralization (illite and kaolinite) indicative of uranium mineralization related to alteration zones. Local area investigations consisted of integrating the AEROTEM (2009) and VTEM (2013) airborne EM data, the associated magnetic observations, and computation of relevant attributes. The comprehensive synthesis of the above geophysical information incorporated all the available and derived geological perspectives. The high-resolution 2D seismic data

Analysis on metallogenic conditions of paleochannel sandstone type uranium deposits in kelulun region

Energy Technology Data Exchange (ETDEWEB)

Mingyue, Feng [Beijing Research Inst. of Uranium Geology, Beijing (China)

1999-07-01

On the basis of comprehensively analyzing metallogenic conditions of paleochannel sandstone type uranium deposits, the author discusses regional geologic background, characteristics of the basement and sedimentary cover of Kelulun basin and Huchawula-Hulun Lake basin, and the metallogenic potential of paleochannel sandstone type uranium deposits is proposed.

Analysis on metallogenic conditions of paleochannel sandstone type uranium deposits in kelulun region

International Nuclear Information System (INIS)

Feng Mingyue

1999-01-01

On the basis of comprehensively analyzing metallogenic conditions of paleochannel sandstone type uranium deposits, the author discusses regional geologic background, characteristics of the basement and sedimentary cover of Kelulun basin and Huchawula-Hulun Lake basin, and the metallogenic potential of paleochannel sandstone type uranium deposits is proposed

The uranium deposits of Ontario

International Nuclear Information System (INIS)

Robertson, J.A.

1981-01-01

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

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.

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

Science.gov (United States)

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

2017-12-18

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

DH-1a: a certified uranium-thorium reference ore

International Nuclear Information System (INIS)

Steger, H.F.; Bowman, W.S.; Zechanowitsch, G.

1981-09-01

A 122-kg sample of uranium-thorium ore, DH-1a, from Elliot Lake, Ontario, was prepared as a compositional reference material to replace the similar certified ore, DH-1. DH-1a was ground to minus 74μm, blended in one lot, and bottled in 200 g units. The homogeneity of DH-1a with respect to uranium was confirmed using the volumetric umpire method. The recommended value for uranium is based on the data from the confirmation of homogeneity. For thorium, twelve laboratories provided results in a free choice analytical program. A statistical analysis of the data gave a recommended value of 0.263 percent for uranium and 0.091 percent for thorium

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

International Nuclear Information System (INIS)

Seguin, H.

1980-01-01

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

Biological aspects and life table of Uroleucon ambrosiae (Thomas, 1878 as a function of temperature

Directory of Open Access Journals (Sweden)

Auad Alexander Machado

2003-01-01

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.

Preliminary U-Th Dating of Endogenic Gypsum From Lake Petén-Itzá, Guatemala

Science.gov (United States)

Gamble, V. C.; Gallup, C. D.; Hodell, D.; Anselmetti, F.; Brenner, M.; Ariztegui, D.

2007-05-01

Uranium-thorium dating of lake sediments can provide accurate ages beyond the range of radiocarbon dating. Many lakes have endogenic precipitation of calcium bearing minerals that allow for substitution by uranium within their crystal structures. The water chemistry of Lake Petén-Itzá, located in northern Guatemala, is dominated by calcium, sulfate and carbonate ions (Deevey et al. 1980; Curtis et al. 1998). Changes in regional climate due to suspected shifts in the ITCZ over the past 85,000 years resulted in both calcite and gypsum deposition, especially during drier periods (Hodell et al. 2006). Both precipitates incorporate uranium from the lake water and can be used for U-Th dating. U-Th dating is problematic in lake systems for several reasons: the potential for 1) diagenetic alteration or dissolution while the endogenic precipitates are settling and after deposition and 2) contamination by detrital thorium. Contamination is a primary issue because of the difficulty of separating the precipitates from the sediment. Despite these concerns, U-Th dating of lake sediments has the potential to be successful with careful selection of precipitates and thorough analysis of the precipitate, the lake system, and the diagenetic environment. Preliminary samples of Lake Petén-Itzá gypsum contain euhedral crystals, indicating a lack of post-depositional alteration. However, the samples have high background thorium levels, indicating the necessity of using the U-Th total sample dissolution isochron dating method (as described by Ku, 2000) to quantify authigenic thorium. Curtis J.H., Brenner M., Hodell D.A., Balser R.A., Islebe G.A., Hooghiemstra H. 1998. A multi-proxy study of Holocene environmental change in the Maya lowlands of Petén, Guatemala. Journal of Paleolimnology 19, 139-159. Deevey E.S., Brenner M., Flannery M.S., Yezdani G.H. 1980. Lakes Yaxha and Scanab, Petén, Guatemala: Limnology and hydrology. Arch. Hydrobiol. 57, 419-460. Hodell D.A., Anselmetti F

Clay minerals trap hydrogen in the Earth's crust: Evidence from the Cigar Lake uranium deposit, Athabasca

Science.gov (United States)

Truche, Laurent; Joubert, Gilles; Dargent, Maxime; Martz, Pierre; Cathelineau, Michel; Rigaudier, Thomas; Quirt, David

2018-07-01

Hydrogen (H2)-rich fluids are observed in a wide variety of geologic settings including gas seeps in serpentinized ultramafic rocks, sub-seafloor hydrothermal vents, fracture networks in crystalline rocks from continental and oceanic crust, and volcanic gases. Natural hydrogen sources can sustain deep microbial ecosystems, induce abiotic hydrocarbons synthesis and trigger the formation of prebiotic organic compounds. However, due to its extreme mobility and small size, hydrogen is not easily trapped in the crust. If not rapidly consumed by redox reactions mediated by bacteria or suitable mineral catalysts it diffuses through the rocks and migrates toward the surface. Therefore, H2 is not supposed to accumulate in the crust. We challenge this view by demonstrating that significant amount of H2 may be adsorbed by clay minerals and remain trapped beneath the surface. Here, we report for the first time H2 content in clay-rich rocks, mainly composed of illite, chlorite, and kaolinite from the Cigar Lake uranium ore deposit (northern Saskatchewan, Canada). Thermal desorption measurements reveal that H2 is enriched up to 500 ppm (i.e. 0.25 mol kg-1 of rock) in these water-saturated rocks having a very low total organic content (reported elsewhere for pure clay minerals or shales. Sudoite (Al-Mg di-trioctahedral chlorite) is probably the main mineral responsible for H2 adsorption in the present case. The presence of multiple binding sites in interlinked nanopores between crystal layers of illite-chlorite particles offers the ideal conditions for hydrogen sorption. We demonstrate that 4 to 17% of H2 produced by water radiolysis over the 1.4-Ga-lifetime of the Cigar Lake uranium ore deposit has been trapped in the surrounding clay alteration haloes. As a result, sorption processes on layered silicates must not be overlooked as they may exert an important control on the fate and mobility of H2 in the crust. Furthermore, the high capacity of clay minerals to sorb molecular

Tax neutrality and the Saskatchewan Uranium Royalty

International Nuclear Information System (INIS)

Campbell, H.F.; Wrean, D.L.

1984-01-01

The effect of the Saskatchewan Uranium Royalty (SUR) on the extraction plans of uranium mining companies operating in Saskatchewan are discussed. The SUR consists of a basic royalty on the value of production and a graduated rate of return tax. Companies are also subject to federal and provincial income taxes. A model, based on the Key Lake mine in Australia, is used to determine whether the tax regime operating in Saskatchewan has the property of neutrality and effects the optimal extraction rate. Results show that SUR is a relatively low-cost means of collecting an economic rent from uranium mining and results in a lower extraction rate contributing to environmental protection in the province. (U.K.)

The effect of isabelin, a sesquiterpene lactone from Ambrosia artemisiifolia on soil microorganisms and human pathogens

NARCIS (Netherlands)

Molinaro, F.; Tyc, O.; Beekwilder, J.; Cankar, Katarina; Bertea, C.M.; Negre, M.; Garbeva, P.V.

2018-01-01

Ambrosia artemisiifolia L. (common ragweed) is an invasive weed, well-known for the strong allergenic effect of its pollen, as well as for its invasiveness and impact in crop fields (e.g. causing yield losses). This species produces a broad range of sesquiterpenoids. In recent years, new bioactive

National Uranium Resource Evaluation: Durango Quadrangle, Colorado

International Nuclear Information System (INIS)

Theis, N.J.; Madson, M.E.; Rosenlund, G.C.; Reinhart, W.R.; Gardner, H.A.

1981-06-01

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

National uranium resource evaluation, Montrose Quadrangle, Colorado

International Nuclear Information System (INIS)

Goodknight, C.S.; Ludlam, J.R.

1981-06-01

The Montrose Quadrangle in west-central Colorado was evaluated to identify and delineate areas favorable for the occurrence of uranium deposits according to National Uranium Resource Evaluation program criteria. General surface reconnaissance and geochemical sampling were conducted in all geologic environments in the quadrangle. Preliminary data from aerial radiometric and hydrogeochemical and stream-sediment reconnaissance were analyzed and brief followup studies were performed. Twelve favorable areas were delineated in the quadrangle. Five favorable areas contain environments for magmatic-hydrothermal uranium deposits along fault zones in the Colorado mineral belt. Five areas in parts of the Harding and Entrada Sandstones and Wasatch and Ohio Creek Formations are favorable environments for sandstone-type uranium deposits. The area of late-stage rhyolite bodies related to the Lake City caldera is a favorable environment for hydroauthigenic uranium deposits. One small area is favorable for uranium deposits of uncertain genesis. All near-surface Phanerozoic sedimentary rocks are unfavorable for uranium deposits, except parts of four formations. All near-surface plutonic igneous rocks are unfavorable for uranium deposits, except five areas of vein-type deposits along Tertiary fault zones. All near-surface volcanic rocks, except one area of rhyolite bodies and several unevaluated areas, are unfavorable for uranium. All near-surface Precambrian metamorphic rocks are unfavorable for uranium deposits. Parts of two wilderness areas, two primitive areas, and most of the subsurface environment are unevaluated

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

International Nuclear Information System (INIS)

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

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.

Uranium in Canada

International Nuclear Information System (INIS)

1989-01-01

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

Uranium tailings in Canada

International Nuclear Information System (INIS)

Boulden, R.S.; Bragg, K.

1982-01-01

The last few years have produced significant changes in the way uranium tailings are managed in Canada. This is due both to the development of new technology and to changes in regulatory approach. The interrelationships between these two areas are examined with particular attention paid to the long term and the development of close-out criteria. New technological initiatives are examined including dry placement techniques, pit disposal and deep lake disposal

International uranium production. An eastern Canadian perspective

International Nuclear Information System (INIS)

Albino, G.R.

1984-01-01

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.)

Interaction of Insecticide and Media Moisture on Ambrosia Beetle (Coleoptera: Curculionidae) Attacks on Selected Ornamental Trees.

Science.gov (United States)

Frank, Steven D; Anderson, Amanda L; Ranger, Christopher M

2017-12-08

Exotic ambrosia beetles, particularly Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae: Scolytinae) and Xylosandrus germanus (Blandford) (Coleoptera: Curculionidae: Scolytinae), are among the most damaging pests of ornamental trees in nurseries. Growers have had few tactics besides insecticide applications to reduce ambrosia beetle attacks but recent research has shown that attacks may be reduced by maintaining media moisture below a 50% threshold thereby reducing flood stress. We compared the efficacy of managing media moisture and insecticide applications for reducing ambrosia beetle attacks on three ornamental tree species in North Carolina. During trials in spring 2013 and 2015, flooded Cornus florida and Cornus kousa were heavily attacked despite sprays with permethrin, but nonflooded C. kousa or C. florida were not attacked. In spring 2015 trials, both nonflooded and flooded Styrax japonicus were heavily attacked regardless of permethrin applications. Although ethanol emissions were not measured, the apparently healthy nonflooded S. japonicus trees may have been exposed to an unknown physiological stress, such as low temperature injury, the previous winter, which predisposed them to beetle attack. However, ethanol levels within host tissues were not measured as part of the current study. X. crassiusculus (75%), Xyloborinus saxesenii Ratzburg (13%), and X. germanus (9%) were the most abundant species collected in ethanol baited traps deployed in 2015, while X. crassiusculus (63%) and X. germanus (36%) were the predominant species reared from attacked trees. Results indicate that managing media moisture levels at or below 50%, and maximizing tree health overall, may provide significant protection against Xylosandrus spp. attacks in flood intolerant tree species. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For permissions, please e-mail: journals.permissions@oup.com.

Methods of evaluating ore processing and effluent treatment for Cigar Lake ore at the Rabbit Lake Mill

International Nuclear Information System (INIS)

Edwards, C.R.

2002-01-01

Cigar Lake is the second-largest, high grade uranium orebody in the world. Mineable reserves for Cigar Lake Phase 1 are estimated at 191 million pounds U 3 O 8 with a grade of 25.6% U 3 O 8 . Subject to regulatory approval, Cameco intends to process the majority of ore from Cigar Lake in the Rabbit Lake mill. Cameco initiated a programme to study the processing of Cigar Lake ore and the treatment of the resulting waste streams. Laboratory and follow-up pilot scale ore leaching tests with Cigar Lake ore samples were performed. Tailings and effluents were generated from the products of the pilot scale leach tests. Mill process tailings were blended with ground waste rock. Using these materials, geotechnical and geochemical properties, including long term tailings pore water characteristics, will be evaluated. In addition, proposed changes to the mill waste treatment operations were developed to deal with increased levels of arsenic and radium in the waste streams. This paper describes the methods and techniques Cameco used in this programme. (author)

Uranium mining

International Nuclear Information System (INIS)

Cheeseman, E.W.

1980-01-01

The international uranium market appears to be currently over-supplied with a resultant softening in prices. Buyers on the international market are unhappy about some of the restrictions placed on sales by the government, and Canadian sales may suffer as a result. About 64 percent of Canada's shipments come from five operating Ontario mines, with the balance from Saskatchewan. Several other properties will be producing within the next few years. In spite of the adverse effects of the Three Mile Island incident and the default by the T.V.A. of their contract, some 3 600 tonnes of new uranium sales were completed during the year. The price for uranium had stabilized at US $42 - $44 by mid 1979, but by early 1980 had softened somewhat. The year 1979 saw the completion of major environmental hearings in Ontario and Newfoundland and the start of the B.C. inquiry. Two more hearings are scheduled for Saskatchewan in 1980. The Elliot Lake uranium mining expansion hearings are reviewed, as are other recent hearings. In the production of uranium for nuclear fuel cycle, environmental matters are of major concern to the industry, the public and to governments. Research is being conducted to determine the most effective method for removing radium from tailings area effluents. Very stringent criteria are being drawn up by the regulatory agencies that must be met by the industry in order to obtain an operating licence from the AECB. These criteria cover seepages from the tailings basin and through the tailings retention dam, seismic stability, and both short and long term management of the tailings waste management area. (auth)

Trace element patterns in lichens following uranium mine closures

International Nuclear Information System (INIS)

Fahselt, D.; Wu, T.W.; Mott, B.

1995-01-01

Instrumental neutron activation analysis was used to determine trace elements in Cladina mitis (Sandst). Hale ampersand Culb. along transects extending from uranium mines at Elliot Lake and Agnew Lake in central Ontario, Canada. Levels of 11 elements were reported and the presence of uranium (U) was confirmed, although U concentrations were much less than in Cladina rangiferina 10 years earlier. Among the elements identified in lichen thalli was Th, which occurred in higher concentrations than U. All trace elements, including the two radionuclides, were found in deteriorating thallus parts as well as living podetia, and five of these seem to have originated as airborne particulates from minesites. In spite of mine closures, levels of Th and U remained higher near sources of ore dust and there was little relationship between radionuclide concentrations in thallus and substrate. 24 refs., 4 figs., 3 tabs

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

International Nuclear Information System (INIS)

1984-07-01

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

Uranium production

International Nuclear Information System (INIS)

Spriggs, M.

1980-01-01

The balance between uranium supply and demand is examined. Should new resources become necessary, some unconventional sources which could be considered include low-grade extensions to conventional deposits, certain types of intrusive rock, tuffs, and lake and sea-bed sediments. In addition there are large but very low grade deposits in carbonaceous shales, granites, and seawater. The possibility of recovery is discussed. Programmes of research into the feasibility of extraction of uranium from seawater, as a by-product from phosphoric acid production, and from copper leach solutions, are briefly discussed. Other possible sources are coal, old mine dumps and tailings, the latter being successfully exploited commercially in South Africa. The greatest constraints on increased development of U from lower grade sources are economics and environmental impact. It is concluded that apart from U as a by-product from phosphate, other sources are unlikely to contribute much to world requirements in the foreseeable future. (U.K.)

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

International Nuclear Information System (INIS)

1989-12-01

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/m 2 .second; sterile rock mainway 25 pCi/m 2 .second; worked-out stope 100 pCi/m 2 .second; active work stope 240 pCi/m 2 .second; and work face 14,000 pCi/m 2 .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

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

International Nuclear Information System (INIS)

1985-03-01

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

Limnological and fisheries investigation of the flooded open pit at the Gunnar uranium mine

International Nuclear Information System (INIS)

Tones, P.I.

1982-02-01

The Gunnar uranium mine on the north shore of Lake Athabaska was closed in 1964 and became flooded. This study describes the physical, chemical and biological characteristics of the water-filled open pit mine. Depth profiles of temperature, dissolved oxygen and specific conductivity indicated the presence of five strata in the 110 m-deep lake during the summer. Radionuclides and dissolved salts were concentrated in the deepest layer, where there was almost no dissolved oxygen and living organisms. The concentrations of heavy metals except uranium are generally very low at all depths. Surface levels of radium 226, thorium, uranium and lead 210 are low. There is no surface seepage out of the pit. Bacteria and phytoplankton populations are typical of those found in warm nutrient-rich waters; the total number of species is low, but there is a large number of individuals. No benthic species are present at the bottom or at 82.5 m. Northern pike, common suckers, and longnose suckers were caught; all appeared to be in good condition and larger than individuals of the same age in the neighbouring lakes. Radionuclide levels in their flesh were one to two orders of magnitude greater than background

Evolution of ore-bearing material sources of endogenous uranium deposits

International Nuclear Information System (INIS)

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

1976-01-01

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

Flood Stress as a Technique to Assess Preventive Insecticide and Fungicide Treatments for Protecting Trees against Ambrosia Beetles

Directory of Open Access Journals (Sweden)

Christopher M. Ranger

2016-08-01

Full Text Available Ambrosia beetles tunnel into the heartwood of trees where they cultivate and feed upon a symbiotic fungus. We assessed the effectiveness of flood stress for making Cercis canadensis L. and Cornus florida L. trees attractive to attack as part of insecticide and fungicide efficacy trials conducted in Ohio and Virginia. Since female ambrosia beetles will not begin ovipositing until their symbiotic fungus is established within the host, we also assessed pre-treatment of trees with permethrin, azoxystrobin, and potassium phosphite on fungal establishment and beetle colonization success. Permethrin reduced attacks on flooded trees, yet no attacks occurred on any of the non-flooded trees. Fewer galleries created within flooded trees pre-treated with permethrin, azoxystrobin, and potassium phosphite contained the purported symbiotic fungus; foundress’ eggs were only detected in flooded but untreated trees. While pre-treatment with permethrin, azoxystrobin, and potassium phosphite can disrupt colonization success, maintaining tree health continues to be the most effective and sustainable management strategy.

Environmental impact of uranium mining and milling

International Nuclear Information System (INIS)

Dory, A.B.

1981-08-01

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

RL-1: a certified uranium reference ore

International Nuclear Information System (INIS)

Steger, H.F.; Bowman, W.S.

1985-06-01

A 145-kg sample of a uranium ore from Rabbit Lake, Saskatchewan, has been prepared as a compositional reference material. RL-1 was ground to minus 74 μm and mixed in one lot. Approximately one half of this ore was bottled in 100-g units, the remainder being stored in bulk. The homogeneity of RL-1 with respect to uranium and nickel was confirmed by neutron activation and X-ray fluorescence analytical techniques. In a 'free choice' analytical program, 13 laboratories contributed results for one or more of uranium, nickel and arsenic in one bottle of RL-1. Based on a statistical analysis of the data, the following recommended values were assigned: U, 0.201%; Ni, 185 μg/g; and As, 19.6 μg/g

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

International Nuclear Information System (INIS)

Walker, G.W.

1980-01-01

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

Diffusion of uranium in H-451 graphite at 900 to 14000C

International Nuclear Information System (INIS)

Tallent, O.K.; Wichner, R.P.; Towns, R.L.

1983-03-01

In this study, the diffusion of uranium (as a stand-in for plutonium) was investigated under conditions approximating those of the primary coolant loop in a High Temperature Gas-Cooled Reactor (HTGR). Profiles were obtained for uranium penetration in H-451 graphite (from the Great Lakes Carbon Company) at temperatures ranging from 900 to 1400 0 C. Diffusion coefficients are established for UO 2 and UC 2

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

International Nuclear Information System (INIS)

Kalin, M.

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

Analysis of geophysical well logs from the Mariano Lake-Lake Valley drilling project, San Juan Basin, Northwestern New Mexico

International Nuclear Information System (INIS)

Scott, J.H.

1986-01-01

Geophysical well logs were obtained in eight deep holes drilled and cored by the U.S. Geological Survey to examine the geology of the Mariano Lake-Lake Valley area in the southern part of the San Juan basin, New Mexico. The logs were made to determine the petrophysical properties of the rocks penetrated by the holes, to aid in making stratigraphic correlations between the holes, and to estimate the grade of uranium enrichment in mineralized zones. The logs can be divided into six categories-nuclear, electric, sonic, magnetic, dipmeter, and borehole conditions. Examples of these logs are presented and related to lithological and petrophysical properties of the cores recovered. Gamma-ray and prompt fission neutron logs were used to estimate uranium grade in mineralized zones. Resistivity and spontaneous potential logs were used to make stratigraphic correlations between drill holes and to determine the variability of the sandstone:mudstone ratios of the major sedimentary units. In one drill hole a dipmeter log was used to estimate the direction of sediment transport of the fluvial host rock. Magnetic susceptibility logs provided supportive information for a laboratory study of magnetic mineral alteration in drill cores. This study was used to infer the geochemical and hydrologic environment associated with uranium deposition in the project area

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

Sedimentology of the Westwater Canyon and Brushy Basin Members, Upper Jurassic Morrison Formation, Colorado Plateau, and relationship to uranium mineralization

International Nuclear Information System (INIS)

Turner-Peterson, C.E.

1987-01-01

The Westwater Canyon Member was deposited by eastward-flowing, high energy, intermittent streams that drained a source area of diverse lithologies. Multi-channel river systems exhibited only minor downstream changes, most notably a slight increase in the amount of lateral accretion deposition. During deposition of the overlying Brushy Basin Member, a large saline, alkaline lake developed in an area that encompasses both the San Juan basin and the Paradox basin. Alteration of airborne volcanic ash that became incorporated in the lake sediments resulted in a lateral zonation of authigenic minerals that resembles the zonation characteristic of Cenozoic saline, alkaline lakes. The lake, named Lake T'oo'dichi, is the largest and oldest saline, alkaline lake known. Localization of primary uranium ore in the Grants uranium region, New Mexico, is more related to depositional facies in the Brushy Basin Member than to any special attribute of the host sandstones in the Westwater Canyon Member. Coincidence of depositional facies in the Brushy Basin Member with ore distribution and ore-related alteration patterns in the Westwater Canyon Member suggests a model in which humic acids originated in pore waters of smectitic mudstones of the Brushy Basin Member and moved downward into the underlying sandstones of the Westwater Canyon Member. Here, the humic acids precipitated to form humin layers that subsequently concentrated uranium from ground water to form the orebodies

Norm Levels in Mine Pit Lakes in South-Western Spain

International Nuclear Information System (INIS)

Manjón, G.; Galván, J.; Mantero, J.; Díaz, I.; García-Tenorio, R.

2015-01-01

Former mining activities in a pyritic area in south-western Spain have generated mine pits in which underground water and rainwater has accumulated. The accumulated waters have produced oxidation of the pyrite and, consequently, the pit water has become acidic, causing the dissolution of metals and radionuclides of natural origin. The paper discusses the activity concentration levels of uranium isotopes and other radionuclides in water samples and sediments collected from these mine pit lakes. Tributaries of the nearby Odiel River, when crossing the mining area, show low pH values and high concentrations of uranium isotopes due to acid mine drainage. Through the analysis of several isotope activity ratios, the presence of radionuclides in the pit lakes and the influence of these radionuclides on the surrounding area and the Odiel River are evaluated. (author)

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

International Nuclear Information System (INIS)

Curry, D.L.

1981-01-01

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

Ensuring safe use of water in a river basin with uranium drainage

International Nuclear Information System (INIS)

Carvalho, F.; Oliveira, J.; Malta, M.

2014-01-01

A regular radioactivity monitoring programme ensures radioactivity surveillance in a river system with multiple and intensive uses of water. In the catchment of River Mondego, centre of Portugal, there is a uranium mining and milling legacy which encompasses about 12 old uranium mine sites and 3 uranium milling sites. This river basin is an important agriculture and cattle growing region with forest areas for paper pulp production. In the catchment of this river there are four dams for electricity production and two main artificial lakes which are water reservoirs to supply drinking water to more than 3 million people, and irrigation water for agriculture including maize and rice production. In the river basin, environmental remediation works were recently implemented especially at the milling tailings and at the major mine sites, which reduced radioactive drainage into the Mondego tributaries and thus into the Mondego river. Mine drainage and seepage from tailings are recuperated and treated in mine water treatment stations. Although, for example, in drainage from milling tailings at Urgeiriça, water may contain high concentrations of dissolved uranium ("2"3"8U), radium ("2"2"6Ra) and polonium ("2"1"0Po) at 35,700±1100, 1084±30, and 700±40 mBq/L, respectively, in the stream receiving discharges of treated water today radionuclide concentrations are orders of magnitude lower. The tributary streams that in the past received untreated mine discharges are today recovering and concentrations decreased to near natural levels. In the artificial lake of Aguieira dam, built on the Mondego River downstream all uranium sites, and where the main capture of water for human consumption is located, radionuclide concentrations were of 9.2±0.3 mBq/L, 17.7±1.9 mBq/L, and 5.3±0.2 mBq/L for uranium ("2"3"8U), radium ("2"2"6Ra) and polonium ("2"1"0Po), respectively. This water has been over the last years consistently in compliance with the EU drinking water quality standards

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.

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)

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

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

International Nuclear Information System (INIS)

Sanford, R.F.

1990-01-01

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

Uranium exploration in Australia

International Nuclear Information System (INIS)

Battey, G.C.; Hawkins, B.W.

1977-01-01

As a result of exploration which recommenced in 1966 Australia's uranium reserves increased from 6,200 tonnes in 1967 to 227,000 tonnes uranium by June 1976. Most discoveries in the early 1950's were made by prospectors. The increase in reserves during the past decade is the result of exploration by companies utilising improved technology in areas selected as geologically favourable. These reserves were established at relatively low cost. In the Alligator Rivers Uranium Province the ''vein'' type deposits at Jabiluka, Ranger, Koongarra and Nabarlek contain 17% of the world's reserves. Most of these discoveries resulted from the investigation of airborne radiometric anomalies but cover over the prospective host rocks will necessitate the future use of costlier and more indirect exploration techniques. There was exploration for sandstone type uranium deposits in most of Australia's sedimentary basins. The greatest success was achieved in the Lake Frome Basin in South Australia. Other deposits were found in the Ngalia and Amadeus Basins in Central Australia and in the Westmoreland area, N.W. Queensland. A major uranium deposit was found in an unusual environment at Yeelirrie, Western Australia where carnotite occurs in a caliche and clay host which fills a shallow, ancient drainage channel. Although caliche occurrences are relatively widespread on the Precambrian shield no other economic deposit has been found. Recent discoveries in the Georgetown area of Queensland indicate the presence of another uranium province but it is too early to assess its potential. The ore occurs in clastic sediments at the base of a volcanic sequence overlying a Precambrian basement. Several companies which have established large uranium reserves have a number of additional attractive prospects. Exploration activity in Australia in 1975 was at a lower level than in previous years, but the potential for discovering further deposits is considered to be high

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

International Nuclear Information System (INIS)

Mazimhaka, P.K.; Hendry, H.E.

1989-01-01

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

Uranium - a challenging mining business

International Nuclear Information System (INIS)

Stadelhofer, J.W.; Wedig, M.J.

2007-01-01

The main application of uranium is its use as a fuel for the nuclear electricity generation. Presently about 68,000 t (177 mill. lbs) of uranium are annually required, of which 41,500 (108 mill. lbs) are provided from fresh mine production whereas 26,500 t (69 mill. lbs) are stock drawdown supplies from civil or military sources. Two-thirds of production are recovered by underground mining and about 75% (30,350 t) of the world's uranium mine production are extracted from top ten mines. All major uranium mining companies are making efforts to enlarge their production capacities: The paramount Cameco's Cigar Lake project has been delayed due to mine water inflow. Production is expected to commence by latest in 2010; the nameplate capacity of 6000 t/a should be reached in 2011. AREVA reported plans to invest about Euro 500 to 600 mill. to double its uranium production by 2010. In 2006 Denison Mines and International Uranium Corporation announced that they have entered into an agreement to merge the two companies in order to create a mid-tier, North American-focused uranium producer with the potential annual production of more than 5.5 mill. lbs of U 3 O 8 by 2010. The skyrocketing global electricity demand, growing public acceptance and more favourable policies have initiated a new round of global development of the nuclear industry. Against this backdrop, about 30,000 t/a to 40,000 t/a of additional mine production will be required within the upcoming 20 years to substitute secondary uranium supplies and to meet the expected increased demand; new start-up junior mining companies (e.g. Paladin) will contribute to this increased production. (orig.)

Interpretation of some geochemical distributions in Key and Seahorse Lakes, Saskatchewan

Energy Technology Data Exchange (ETDEWEB)

Parslow, G.R.

1979-04-01

U, Fe, Mn, Ni, Cu, Zn and Co data for the sediment in both Key and Seahorse lakes, which overlie portions of known economic uranium deposits in the region, are presented. With the exception of U, Fe and Mn, the elemental distributions can be considered anomalous, in a statistical sense, in both lakes. The U values are of particular interest in that Key Lake is not anomalous, whereas Seahorse Lake is markedly anomalous. Tentative correlations made with background data from other surveys in attempt to differentiate between anomalous and background values indicate that deviations from linearity in a distribution, and not absolute mean or maximum values, are indicative of anomalous samples within the distribution.

Crusher isolation to keep Key Lake mill dust free

International Nuclear Information System (INIS)

Turnbull, Andy.

1982-01-01

About a mile of four-inch pipe will virtually eliminate dust in the mill area of the new Key Lake uranium mine when production begins in the summer of 1983. The ore from the pit will be crushed beside the pit, wetground, and piped as a slurry to the mill, which will be isolated from dust-producing processes. The pipeline will carry about 780 tons per day and will replace about one and half haulage trucks. The mill will be able to extract more than 99 percent of the uranium from the ore, which contains about 2.5 to 2.7 percent uranium. The life span of the mine is planned to be about 20 years, with a production of 12 million pounds of yelloscake a year. There will never be a townsite at Key Lake because personnel are to be flown in for seven days of 11-hour shifts, then fly out for seven days off. The tailings pond under construction is designed for sastes which will soon become dry and solid due to the high gypsum content of the ore. Process water from the mine will be held in one of five ponds for a day and released only after monitoring. An ammonium sulfate crystallization plant on the site will use waste from the uranium precipitation process to make fertilizer. The mine and mill are costing about $500 million to develop and bring into production

International uranium supply to the US market

International Nuclear Information System (INIS)

Bonny, J.

1987-01-01

The 1980s have seen a major redistribution of global uranium production. Since 1984, the first full year of production from the Key Lake Mine, Canada has displaced the US as the world's largest uranium producer. Uranium production in the US has stabilized in the range of 10 to 15 million lb U 3 O 8 per year, having declined from a peak of over 43 million lb in 1980. Production from Africa and Europe has declined slightly, and Australia, with the startup of Ranger Mine, has emerged as a significant producer. The main factors that have affected the distribution of production aside from price and demand are ore grades and production costs, currency exchange rates, long-term contracts, and tied supply. It is interesting to examine uranium supply and demand for the North American continent. In 1980 and 1981, North American production was more than twice reactor requirements. By 1985, however, requirements were only slightly lower than production, a situation that has persisted into 1987. Indeed, given the export commitments by Canadian and US producers to Europe and Asia, it is apparent that the US must import uranium from other countries. The relative balance in North American supply and demand suggests that free trade between Canada and the US for both uranium and conversion services would be beneficial to both countries

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

International Nuclear Information System (INIS)

Moemen, A.M.E.

2012-01-01

This work achieved to study the effects of, mixture of salt 2:2:1 (Na Cl-CaCl 2 and Mg SO 4 ), 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.

The uranium potential of the Bushveld igneous complex

International Nuclear Information System (INIS)

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

1987-06-01

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

Environmental impact of uranium mining and milling

International Nuclear Information System (INIS)

Dory, A.B.

1981-08-01

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

Vertical Distribution and Daily Flight Periodicity of Ambrosia Beetles (Coleoptera: Curculionidae) in Florida Avocado Orchards Affected by Laurel Wilt.

Science.gov (United States)

Menocal, Octavio; Kendra, Paul E; Montgomery, Wayne S; Crane, Jonathan H; Carrillo, Daniel

2018-03-08

Ambrosia beetles have emerged as significant pests of avocado ((Persea americana Mill. [Laurales: Lauraceae])) due to their association with pathogenic fungal symbionts, most notably Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva (Ophiostomatales: Ophiostomataceae), the causal agent of the laurel wilt (LW) disease. We evaluated the interaction of ambrosia beetles with host avocado trees by documenting their flight height and daily flight periodicity in Florida orchards with LW. Flight height was assessed passively in three avocado orchards by using ladder-like arrays of unbaited sticky traps arranged at three levels (low: 0-2 m; middle: 2-4 m; high: 4-6 m). In total, 1,306 individuals of 12 Scolytinae species were intercepted, but six accounted for ~95% of the captures: Xyleborus volvulus (Fabricius) (Coleoptera: Curculionidae), Xyleborinus saxesenii Ratzeburg (Coleoptera: Curculionidae), Euplatypus parallelus (Fabricius) (Coleoptera: Curculionidae), Xyleborus bispinatus Eichhoff (Coleoptera: Curculionidae), Xyleborus affinis Eichhoff (Coleoptera: Curculionidae), and Hypothenemus sp. (Coleoptera: Curculionidae). The primary vector of R. lauricola, Xyleborus glabratus Eichhoff (Coleoptera: Curculionidae), was not detected. Females of X. volvulus showed a preference for flight at low levels and X. bispinatus for the low and middle levels; however, captures of all other species were comparable at all heights. At a fourth orchard, a baiting method was used to document flight periodicity. Females of X. saxesenii and Hypothenemus sp. were observed in flight 2-2.5 h prior to sunset; X. bispinatus, X. volvulus, and X. affinis initiated flight at ~1 h before sunset and Xylosandrus crassiusculus (Motschulsky) (Coleoptera: Curculionidae) at 30 min prior to sunset. Results suggest that ambrosia beetles in South Florida fly near sunset (when light intensity and wind speed decrease) at much greater heights than previously assumed and have species-specific patterns in host

North American Lauraceae: terpenoid emissions, relative attraction and boring preferences of redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae).

Science.gov (United States)

Paul E. Kendra; Wayne S. Montgomery; Jerome Niogret; Grechen E. Pruett; Albert (Bud) Mayfield; Martin MacKenzie; Mark A. Deyrup; Gary R. Bauchan; Randy C. Ploetz

2014-01-01

Abstract 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...

Geology of the Honeymoon Uranium Project

International Nuclear Information System (INIS)

Bampton, K.F.; Haines, J.B.; Randell, M.H.

2001-01-01

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

Reports on investigations of uranium anomalies. National Uranium Resource Evaluation

International Nuclear Information System (INIS)

Goodknight, C.S.; Burger, J.A.

1982-10-01

During the National Uranium Resource Evaluation (NURE) program, conducted for the US Department of Energy (DOE) by Bendix Field Engineering Corporation (BFEC), radiometric and geochemical surveys and geologic investigations detected anomalies indicative of possible uranium enrichment. Data from the Aerial Radiometric and Magnetic Survey (ARMS) and the Hydrogeochemical and Stream-Sediment Reconnaissance (HSSR), both of which were conducted on a national scale, yielded numerous anomalies that may signal areas favorable for the occurrence of uranium deposits. Results from geologic evaluations of individual 1 0 x 2 0 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

Distribution of uranium series radionuclides in upland vegetation of northern Saskatchewan

International Nuclear Information System (INIS)

Sheard, J.W.

1986-01-01

Multivariate methods are used to explore patterns of accumulation of radionuclides and stable elements among 10 plant species at four localities in northern Saskatchewan. Principal components analysis and canonical correlation analysis of the radionuclides and stable elements showed that lead-210 and polonium-210 are correlated with crustal elements distributed in the atmoshpere and therefore are accumulated more abundantly by lichen and moss species than by vascular plants. Uranium showed a similar trend. Neither these radionuclides nor radium-226 showed strong correlations with other stable elements. The highest accumulation of uranium was in the Wollaston Lake region, especially for the nonvascular plants, where the soil levels are lowest. This tends to substantiate previous suggestions that uranium available for uptake by vascular plants is associated with groundwater rather than soil particles. Canonical variates analysis on radionuclide levels in vegetation by species group shows that trees, shrubs, lichens, and moss all have significantly different patterns of accumulation. The vascular and nonvascular groups are separated primarily by lead-210 and polonium- 210 accumulation. The trees and shrubs are separated by radium-226 levels. A similar analysis by locality showed significant differences in radionuclide accumulation by vegetation in all possible pairs of localities, except between the two Wollaston Lake localities. The largest distances were between regions and were based primarily on uranium accumulation in the nonvascular plants. Differences in radium-226 levels among the shrub species are responsible for the significant difference between the two localities in the Churchill River region

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...

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

International Nuclear Information System (INIS)

Morin, K.A.; Cherry, J.A.

1982-01-01

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 226 Ra and 210 Pb. 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 226 Ra, 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 226 Ra, 210 Pb, and uranium are removed from solution by adsorption or coprecipitation

Non-Native Ambrosia Beetles as Opportunistic Exploiters of Living but Weakened Trees.

Science.gov (United States)

Ranger, Christopher M; Schultz, Peter B; Frank, Steven D; Chong, Juang H; Reding, Michael E

2015-01-01

Exotic Xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. We sought to characterize the role of host physiological condition on preference and colonization by two invaders, Xylosandrus germanus and Xylosandrus crassiusculus. When given free-choice under field conditions among flooded and non-flooded deciduous tree species of varying intolerance to flooding, beetles attacked flood-intolerant tree species over more tolerant species within 3 days of initiating flood stress. In particular, flood-intolerant flowering dogwood (Cornus florida) sustained more attacks than flood-tolerant species, including silver maple (Acer saccharinum) and swamp white oak (Quercus bicolor). Ethanol, a key host-derived attractant, was detected at higher concentrations 3 days after initiating flooding within stems of flood intolerant species compared to tolerant and non-flooded species. A positive correlation was also detected between ethanol concentrations in stem tissue and cumulative ambrosia beetle attacks. When adult X. germanus and X. crassiusculus were confined with no-choice to stems of flood-stressed and non-flooded C. florida, more ejected sawdust resulting from tunneling activity was associated with the flood-stressed trees. Furthermore, living foundresses, eggs, larvae, and pupae were only detected within galleries created in stems of flood-stressed trees. Despite a capability to attack diverse tree genera, X. germanus and X. crassiusculus efficiently distinguished among varying host qualities and preferentially targeted trees based on their intolerance of flood stress. Non-flooded trees were not preferred or successfully colonized. This study demonstrates the host-selection strategy exhibited by X. germanus and X. crassiusculus in non-native habitats involves

Non-Native Ambrosia Beetles as Opportunistic Exploiters of Living but Weakened Trees.

Directory of Open Access Journals (Sweden)

Christopher M Ranger

Full Text Available Exotic Xylosandrus spp. ambrosia beetles established in non-native habitats have been associated with sudden and extensive attacks on a diverse range of living trees, but factors driving their shift from dying/dead hosts to living and healthy ones are not well understood. We sought to characterize the role of host physiological condition on preference and colonization by two invaders, Xylosandrus germanus and Xylosandrus crassiusculus. When given free-choice under field conditions among flooded and non-flooded deciduous tree species of varying intolerance to flooding, beetles attacked flood-intolerant tree species over more tolerant species within 3 days of initiating flood stress. In particular, flood-intolerant flowering dogwood (Cornus florida sustained more attacks than flood-tolerant species, including silver maple (Acer saccharinum and swamp white oak (Quercus bicolor. Ethanol, a key host-derived attractant, was detected at higher concentrations 3 days after initiating flooding within stems of flood intolerant species compared to tolerant and non-flooded species. A positive correlation was also detected between ethanol concentrations in stem tissue and cumulative ambrosia beetle attacks. When adult X. germanus and X. crassiusculus were confined with no-choice to stems of flood-stressed and non-flooded C. florida, more ejected sawdust resulting from tunneling activity was associated with the flood-stressed trees. Furthermore, living foundresses, eggs, larvae, and pupae were only detected within galleries created in stems of flood-stressed trees. Despite a capability to attack diverse tree genera, X. germanus and X. crassiusculus efficiently distinguished among varying host qualities and preferentially targeted trees based on their intolerance of flood stress. Non-flooded trees were not preferred or successfully colonized. This study demonstrates the host-selection strategy exhibited by X. germanus and X. crassiusculus in non-native habitats

Building a Uranium Heap Leach Project

International Nuclear Information System (INIS)

Schnell, Henry

2014-01-01

Despite all these we have seen many HL successes and many interesting projects coming down the pipe. • Previous experience in Uranium with previous ROM projects in France (Bessines, Langone), Niger (Somair), Canada (Agnew Lake) and other locations had provided some basic background. • Heap leach based on copper experience with crushed ore has operated for many years in Brazil (Caetite). • Many gold operations for many decades in all climates and continents. • Copper at +20% of production, many in Chile, but also now in many other countries. • Uranium with agglomerated crushed ores is now becoming more prominent – Somair, Imouraren, Trekkopje. • Work also ongoing for Ranger, Rossing, and in consideration for other projects. • Other notable work in Nickel, and multi-metal such as Talvivaara

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

International Nuclear Information System (INIS)

Melis, L.A.

1983-03-01

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

LASL approach to uranium geochemical reconnaissance

Energy Technology Data Exchange (ETDEWEB)

Sharp, R.R. Jr.

1977-01-01

The US ERDA, as part of the NURE program, has initiated a nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR). The aims of the NURE program are to provide data on which to base more accurate estimates of US uranium reserves for long-range planning and to aid in meeting the nation's projected uranium demands into the next century. The HSSR objective is to complete, by 1980, a reconnaissance of the nation's surface waters, ground waters, and stream and lake sediments, to aid in assessment of uranium reserves and identification of areas of interest for exploration. Patterned after extensive uranium reconnaissance done in many other countries, the LASL project is comprised of the following five components: (1) organization and planning, which includes management, design, and execution; (2) field sampling, which includes orientation studies, generation of specifications, and contracting and inspection of field work; (3) sample receiving and analysis, which includes development of methods and hardware, quality assurance, and archival storage; (4) data handling and presentation, including verification, storage, output, and plotting; and (5) data evaluation and publication, which incorporates geochemical, geological, statistical, and empirical evaluation and report writing. The LASL approach to each component and the current status in each state are described.

LASL approach to uranium geochemical reconnaissance

International Nuclear Information System (INIS)

Sharp, R.R. Jr.

1977-01-01

The US ERDA, as part of the NURE program, has initiated a nationwide Hydrogeochemical and Stream Sediment Reconnaissance (HSSR). The aims of the NURE program are to provide data on which to base more accurate estimates of US uranium reserves for long-range planning and to aid in meeting the nation's projected uranium demands into the next century. The HSSR objective is to complete, by 1980, a reconnaissance of the nation's surface waters, ground waters, and stream and lake sediments, to aid in assessment of uranium reserves and identification of areas of interest for exploration. Patterned after extensive uranium reconnaissance done in many other countries, the LASL project is comprised of the following five components: (1) organization and planning, which includes management, design, and execution; (2) field sampling, which includes orientation studies, generation of specifications, and contracting and inspection of field work; (3) sample receiving and analysis, which includes development of methods and hardware, quality assurance, and archival storage; (4) data handling and presentation, including verification, storage, output, and plotting; and (5) data evaluation and publication, which incorporates geochemical, geological, statistical, and empirical evaluation and report writing. The LASL approach to each component and the current status in each state are described

Uranium hydrogeochemical and stream sediment reconnaissance of the McGrath and Talkeetna NTMS Quadrangles, Alaska, including concentrations of forty-three additional elements

International Nuclear Information System (INIS)

Aamodt, P.L.; Jacobsen, S.I.; Hill, D.E.

1979-04-01

During the summer of 1977, 1268 water and 1206 sediment samples were collected from 1292 lakes and streams throughout the two quadrangles in south-central Alaska. Each of the water samples was analyzed for uranium and 12 other elements and each of the sediment samples for uranium, thorium, and 41 other elements. Uranium concentrations in water samples range from below 0.02 ppB to 19.64 ppB. In general, lake waters contain somewhat less uranium than stream waters, and the highest concentrations in both sample types were found in or near the Alaska Range. Uranium concentrations in sediment samples range from 0.10 ppM to 172.40 ppM. The highest concentrations are found in samples collected in the Alaska Range near areas of felsic igneous rocks. Sediment samples having high thorium concentrations also come from areas underlain by felsic igneous rocks in the Alaska Range. The following areas were found to be most favorable for significant uranium mineralization: (1) the Windy Fork stock on the southeastern boundary of the McGrath quadrangle; (2) an area in the northwest corner of the Talkeetna quadrangle near the Mespelt prospects; (3) the Hidden River drainage in the northeast corner of the Talkeetna quadrangle; (4) an area near Chelatna Lake in the center of the Talkeetna quadrangle; (5) the Kichatna River drainage, near the western border of the Talkeetna quadrangle; and (6) an area near the Mount Estelle pluton in the extreme southwest corner of the Talkeetna quadrangle

Geophysical experiments at Mariano Lake uranium orebody

International Nuclear Information System (INIS)

Thompson, D.T.

1980-01-01

Several geophysical experiments were performed over the Mariano Lake orebody before mining. Surface self-potential methods, surface-to-hole induced-polarization methods, and reflection-seismic methods were used. These geophysical techniques provided data which relate to the conceptual model of this orebody. Currents generated in the productive formation by oxidation-reduction reactions do not generate measurable potential anomalies at the surface. Surface-to-hole induced-polarization measurements apparently can detect an oxidation-reduction front in the vicinity of an exploration borehole. Reflection-seismic techniques can provide information concening the paleostructure of the area

Radiological survey results at 4400 Piehl Road, Ottawa Lake, Michigan

International Nuclear Information System (INIS)

Foley, R.D.; Johnson, C.A.

1993-04-01

At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory conducted a radiological survey at 4400 Piehl Road in Ottawa Lake, Michigan. The survey was performed in September, 1992. The purpose of the survey was to determine if materials containing uranium from work performed under government contract at the former Baker Brothers facility in Toledo, Ohio had been transported off-site to this neighboring area. The radiological survey included surface gamma scans indoors and outdoors, alpha and beta scans inside the house and attached garage, beta-gamma scans of the hard surfaces outside, and the collection of soil, water, and dust samples for radionuclide analyses. Results of the survey demonstrated that the majority of the measurements on the property were within DOE guidelines. However, the presence of isolated spots of uranium contamination were found in two areas where materials were allegedly transported to the property from the former Baker Brothers site. Uranium uptake by persons on the property by ingestion is fairly unlikely, but inhalation is a possibility. Based on these findings, it is recommended that the residential property at 4400 Piehl Road in Ottawa Lake, Michigan be considered for inclusion under FUSRAP

Entomopathogenic fungi as a biological control agents for the vector of the laurel wilt disease, the redbay ambrosia beetle, Xyleborus glabratus (Coleoptera: Curculionidae)

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...

Preconcentration of low-grade uranium ores with environmentally acceptable tailings, part I

International Nuclear Information System (INIS)

Raicevic, D.; Raicevic, M.; McCarthy, D.R.

1979-08-01

The low-grade ore sample used for this investigation originated from Agnew Lake Mines Limited, Espanola, Ontario. It contained about 1% pyrite and 0.057% uranium, mainly as uranothorite with a small amount of brannerite. Both of these minerals occur in the quartz-sericite matrix of a conglomerate. A preconcentration process has been developed to give a high uranium recovery, reject pyrite, radium and thorium from the ore and produce environmentally acceptable tailings. This process applies flotation in combination with high intensity magnetic separation and gravity concentration

Recent activities and trend in the uranium market

International Nuclear Information System (INIS)

Kwasny, R.; Aul, F.; Lohrey, K.

2007-01-01

Concerns about the impact of hydrocarbon use on climate and global warming are significantly growing. Furthermore, we are all well aware that security of supply is increasingly an issue. In this context, it is now principally recognised that nuclear energy has to be back on the agenda. All in all, the prospects for the nuclear power industry and thus for the uranium activities is very positive for the coming years. The changes that have taken place in the international uranium market during the past several years are remarkable. Since 2002, the uranium prices have increased more than tenfold. The spot market price of uranium began an increase from about USD 9/lb U 3 O 8 in mid 2001 following a fire at the Olympic Dam mill (Australia) in October 2001 and was propelled in subsequent years by a series of interrupting events, such as the mine shaft flooding at the McArthur River mine (Canada) in April 2003, the threat of the early shutdown of the Roessing mine (Namibia) and the Ranger mine (Australia) in 2003, the decision of Techsnabexport (Tenex, Russia) in October 2003 to terminate sales of UF6 to the US trading company Globe Nuclear Services and Supply GNSS Ltd. (GNSS), and finally the complete flooding at the developing Cigar Lake mine (Canada) in October 2006. With the emergence of hedge funds and investors, that began in late 2004, increased uranium demand and upward pressure on market prices were further stimulated. What about the recent events and trends in the uranium industry? Are the uranium producers and the utilities well prepared to meet all the challenges associated with developments in the uranium business? And what about the risks, uncertainties and other factors that could affect the developments in the uranium industry and uranium markets? (orig.)

Final report of the AECL/SKB Cigar Lake analog study

International Nuclear Information System (INIS)

Cramer, J.

1994-05-01

The Cigar Lake uranium deposit is located in northern Saskatchewan, Canada. The 1.3-billion-year-old deposit is located at a depth of about 450 m below surface in a water-saturated sandstone at the unconformity contact with the high-grade metamorphic rocks of the Canadian Shield. The Cigar Lake deposit 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 indicates 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 UO 2 fuel waste, the performance of clay-based barriers, radionuclide migration, colloid formation, radiolysis, fission-product geochemistry and general aspects of water-rock interaction. The main geochemical 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. Since 1984, through cooperation from the owners of the Cigar Lake deposit, analog studies have been conducted. AECL, with support from Ontario Hydro under the auspices of the CANDU Owners Group, initiated international participation in 1989 through collaboration with the Swedish Nuclear Fuel and Waste Management Company (SKB) and, more recently, with the Los Alamos National Laboratory (LANL). This report gives the results of the various studies carried out during the 3-year collaboration between AECL and SKB, as well as a summery of the LANL study. It provides detailed information on the generated databases and models, and integrates this information into conclusions for use in safety

Isolations from the redbay ambrosia beetle, Xyleborus glabratus, confirm that the laurel wilt pathogen, Raffaelea lauricola, originated in Asia

Science.gov (United States)

Thomas C. Harrington; Hye Young Yun; Sheng-Shan Lu; Hideaki Goto; Dilzara N. Aghayeva; Stephen W. Fraedrich

2011-01-01

The laurel wilt pathogen Raffaelea lauricola was hypothesized to have been introduced to the southeastern USA in the mycangium of the redbay ambrosia beetle, Xyleborus glabratus, which is native to Asia. To test this hypothesis adult X. glabratus were trapped in Taiwan and on Kyushu Island, Japan, in 2009, and dead beetles were sent to USA for isolation of fungal...

Results of uranium HSSR survey of the San Juan area southwestern Colorado

International Nuclear Information System (INIS)

Maxwell, J.C.

1977-01-01

During June--July 1976, 1706 water samples and 1982 sediment samples were collected from 1995 sites in the San Juan Mountains area and analyzed for uranium. The area includes the southern third of the Colorado mineral belt which has yielded rich ores of gold, silver, copper, lead, zinc, and molybdenum. The broadly domed mountains are capped by 2500 m of Tertiary volcanics, deeply eroded to expose a Precambrian crystalline core. Adjacent plateaus underlain by Mesozoic sedimentary rocks were included in the reconnaissance. Average value of uranium in water samples from mountains was less than 0.5 ppB, from plateaus was 1 to 2 ppB, and from Mancos shale areas exceeded 2 ppB. Anomalous sediment samples, 40 ppM uranium, came from near Storm King Mountain and upper Vallecito Creek. Other anomalous areas, including the Lake City mining district, were well defined by 4 to 30 ppM uranium in sediment and 3 to 30 ppB uranium in water. Above-average concentrations of uranium not previously reported indicate areas favorable for detailed exploration

Cost study on waste management at three model Canadian uranium mines

International Nuclear Information System (INIS)

1984-03-01

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 U 3 O 8 ) 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 U 3 O 8 , 0.475 percent U 3 O 8 and 1.5 percent U 3 O 8 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

Bioassays with caged hyalella azteca to determine in situ toxicity downstream of two Saskatchewan, Canada, uranium operations.

Science.gov (United States)

Robertson, Erin L; Liber, Karsten

2007-11-01

The main objectives of this in situ study were to evaluate the usefulness of an in situ bioassay to determine if downstream water bodies at the Key Lake and Rabbit Lake uranium operations (Saskatchewan, Canada) were toxic to Hyalella azteca and, if toxicity was observed, to differentiate between the contribution of surface water and sediment contamination to in situ toxicity. These objectives were achieved by performing 4-d in situ bioassays with laboratory-reared H. azteca confined in specially designed, paired, surface water and sediment exposure chambers. Results from the in situ bioassays revealed significant mortality, relative to the respective reference site, at the exposure sites at both Key Lake (p Lake (p = 0.001). No statistical differences were found between survival in surface water and sediment exposure chambers at either Key Lake (p = 0.232) or Rabbit Lake (p = 0.072). This suggests that surface water (the common feature of both types of exposure chambers) was the primary cause of in situ mortality of H. azteca at both operations, although this relationship was stronger at Key Lake. At Key Lake, the primary cause of aquatic toxicity to H. azteca did not appear to be correlated with the variables measured in this study, but most likely with a pulse of organic mill-process chemicals released during the time of the in situ study-a transient event that was caused by a problem with the mill's solvent extraction process. The suspected cause of in situ toxicity to H. azteca at Rabbit Lake was high levels of uranium in surface water, sediment, and pore water.

Fate and transport modelling of uranium in Port Hope Harbour

International Nuclear Information System (INIS)

Pinilla, C.E.; Garisto, N.; Peters, R.

2010-01-01

Fate and transport modelling of contaminants in Port Hope Harbour and near-shore Lake Ontario was undertaken in support of an ecological and human health risk assessment. Uranium concentrations in the Harbour and near-shore Lake Ontario due to groundwater and storm water loadings were estimated with a state-of-the-art 3D hydrodynamic and contaminant transport model (ECOMSED). The hydrodynamic model was simplified to obtain a first estimate of the flow pattern in the Harbour. The model was verified with field data using a tracer (fluoride). The modelling results generally showed good agreement with the tracer field data. (author)

Uranium and radium-226 in runoff from the rehabilitated Rum Jungle Creek South uranium mine, Northern territory: interim results and health implications

International Nuclear Information System (INIS)

Woods, P.H.

1993-01-01

The Rum Jungle Creek South uranium mine is located 3 km west of the town of Batchelor, Northern Territory, and was mined between 1961 and 1963. No formal rehabilitation was carried out after mining. The open pit filled with water of good quality and the site became a popular recreation area for picnicking, camping and water activities. The popularity of the area meant that high radiation and health protection standards need to be considered. Rehabilitation works to render the site radiologically suitable for unrestricted access were carried out in 1990 and 1991. Initial sampling over the 1991/92 wet season showed that the runoff was acidic (pH 3.7 to 6.2) and had elevated electrical conductivity (EC 134 to 1080 μS cm -1 ) due to dissolved weathering products. Diversion of runoff from the dump away from the pit ensured that there was no observable effect on the lake, and field measurements confirmed effective dilution and no observed effect on the receiving stream. Three samples of runoff from the main drain on the rehabilitated waste rock dump (taken on 25 February 1992) were analysed for uranium and radium, with values between 5 and 3960 μg L -1 for uranium and 0.026 and 0.180 Bq L -1 for Ra-226. The drains leading from the dump flow only during and immediately after large rainfall events. They do not impact on the suitability of the lake for recreational use (during 1990-91, uranium and Ra-226 ranged from 20 to 43 μ L -1 , and from 0.033 to 0.083 Bq L -1 , respectively). Dilution of at least one thousand times is achieved in the receiving stream prior to the first downstream habitation, so no health problems are anticipated for potential downstream users. 14 refs., 3 tabs., 2 figs

Radionuclides in the lichen-caribou-human food chain near uranium mining operations in northern Saskatchewan, Canada.

OpenAIRE

Thomas, P A; Gates, T E

1999-01-01

The richest uranium ore bodies ever discovered (Cigar Lake and McArthur River) are presently under development in northeastern Saskatchewan. This subarctic region is also home to several operating uranium mines and aboriginal communities, partly dependent upon caribou for subsistence. Because of concerns over mining impacts and the efficient transfer of airborne radionuclides through the lichen-caribou-human food chain, radionuclides were analyzed in tissues from 18 barren-ground caribou (Ran...

An evaluation of the chemical, radiological, and ecological conditions of West Lake on the Hanford site

Energy Technology Data Exchange (ETDEWEB)

Poston, T.M.; Price, K.L.; Newcomer, D.R.

1991-03-01

West Lake and its immediate surrounding basin represent a unique habitat that is dominated by highly saline water and soil. The basin offers a valuable research site for studies of a rare and complex wetland area in the desert. This report is an evaluation of the chemical, radiological, and ecological conditions at West Lake and describes how ground water influences site properties. The scope of this evaluation consisted of a sampling program in 1989 and a review of data from the perspective of assessing the impact of Hanford Site operations on the physical, chemical, and ecological conditions of West Lake and its surrounding basin. The water level in West Lake fluctuates in relation to changes in the water table. The connection between West Lake and ground water is also supported by the presence of {sup 3}H and {sup 99}Tc in the ground water and in the lake. There are relatively high concentrations of uranium in West Lake; the highest concentrations are found in the northernmost isolated pool. Analyses of water, sediment, vegetation, and soil indicate possible shifts of isotropic ratios that indicate a reduction of {sup 235}U. Uranium-236 was not detected in West Lake water; its presence would indicate neutron-activated {sup 235}U from fuel reprocessing at Hanford. Trace metals are found at elevated concentrations in West Lake. Arsenic, chromium, copper, and zinc were found at levels in excess of US Environmental Protection Agency water quality criteria. Levels of radiological and chemical contamination in the West Lake basin are relatively low. Concentrations of fission isotopes exceed those that could be explained by atmospheric fallout, but fall short of action levels for active waste management areas. 31 refs., 8 figs., 18 tabs.

An evaluation of the chemical, radiological, and ecological conditions of West Lake on the Hanford site

International Nuclear Information System (INIS)

Poston, T.M.; Price, K.L.; Newcomer, D.R.

1991-03-01

West Lake and its immediate surrounding basin represent a unique habitat that is dominated by highly saline water and soil. The basin offers a valuable research site for studies of a rare and complex wetland area in the desert. This report is an evaluation of the chemical, radiological, and ecological conditions at West Lake and describes how ground water influences site properties. The scope of this evaluation consisted of a sampling program in 1989 and a review of data from the perspective of assessing the impact of Hanford Site operations on the physical, chemical, and ecological conditions of West Lake and its surrounding basin. The water level in West Lake fluctuates in relation to changes in the water table. The connection between West Lake and ground water is also supported by the presence of 3 H and 99 Tc in the ground water and in the lake. There are relatively high concentrations of uranium in West Lake; the highest concentrations are found in the northernmost isolated pool. Analyses of water, sediment, vegetation, and soil indicate possible shifts of isotropic ratios that indicate a reduction of 235 U. Uranium-236 was not detected in West Lake water; its presence would indicate neutron-activated 235 U from fuel reprocessing at Hanford. Trace metals are found at elevated concentrations in West Lake. Arsenic, chromium, copper, and zinc were found at levels in excess of US Environmental Protection Agency water quality criteria. Levels of radiological and chemical contamination in the West Lake basin are relatively low. Concentrations of fission isotopes exceed those that could be explained by atmospheric fallout, but fall short of action levels for active waste management areas. 31 refs., 8 figs., 18 tabs

Metallogenesis and metallogenic model of Nuheting uranium deposit in Erlian Basin

International Nuclear Information System (INIS)

Li Hongjun; Kuang Wenzhan

2010-01-01

Based on the study on geological characteristics, metallogesis and geochemical features in Nuheting uranium deposit, it is considered that the deposit belongs to syn-sedimentary and epigenetic reworking type. The deposit position was controlled by the lake area developed during Erlian period in Late Cretaceous. The metallognesis has experienced three stages, they are syn-sedimentary metallogenesis, epigenetic reworking metallogenesis and exogenic metallogenesis. The ore-forming ages are respectively 85 Ma, (41±5)Ma and 6-13 Ma. Based on the summary of metallogenic geological features,metallogenesis and geochemical features, the metallogenic model of Nuheting uranium deposit has been established. (authors)

Investigations in hydrogeochemical samples for uranium exploration

International Nuclear Information System (INIS)

Krishnakumar, M.

2015-01-01

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

Comparing recent uranium supply scenarios

International Nuclear Information System (INIS)

Arnold, N.; Gufler, K.

2014-01-01

For more than one decade – even after the Fukushima accidents - an increase in global nuclear energy generation capacity is widely expected. At the same time a variety of uranium supply scenarios were published by industry, academics or international organizations, drawing different pictures of future uranium supply. They were created with the background of a uranium market facing several challenges. First an excursion in the uranium market price, in 2007, then reduced nuclear growth expectations after 2011, at least in non-Asian countries, also implying considerable changes to the supply side. For this publication a meta-study was carried out identifying, evaluating and comparing different recent scenarios on the availability of uranium. While there are some differences in the frame conditions (e.g. the expected uranium demand, the time fame, the considered mining projects,..), there are also notable similarities in these scenarios. This concerns long lead times for mine openings as well as the dependence on large mining projects (e.g. Olympic Dam, Cigar Lake). Generally, a decline in production in about 10 years is assumed, and thus the necessity of the timely development of mining projects is pointed out. In addition the omission of uranium from Russian nuclear weapons and the chances of keeping the changes in secondary supplies in balance with primary production have been widely discussed. Here, the production growth in Kazakhstan but also the role of the current market situation are central aspects. As another aspect the possible contribution from unconventional resources is of interest, particularly against the background of rising production costs for conventional resources. Finally, it shall be reflected how well older scenarios were able to map the reality and which trends could or could not be anticipated. It is relevant to identify which aspects in the development of mining capacities are essential for security of supply, and can therefore be regarded

Lake Champlain 10 x 20 NTMS area New York, Vermont, and New Hampshire: data report (abbreviated). National Uranium Resource Evaluation program, hydrogeochemical and stream sediment reconnaissance

International Nuclear Information System (INIS)

Cook, J.R.

1981-03-01

This abbreviated data report presents results of ground water and stream sediment reconnaissance in the National Topographic Map Series (NTMS) Lake Champlain 1 0 x 2 0 quadrangle. Surface sediment samples were collected at 1196 sites. Ground-water samples were collected at 619 sites. Neutron activation analysis (NAA) results are given for uranium and 16 other elements in sediments, for uranium and 8 other elements in ground water, and for uranium and 9 other elements in surface water. Field measurements and observations are reported for each site. Analytical data and field measurements are presented in tables and maps. Data from ground-water sites include (1) water chemistry measurements (pH, conductivity, and alkalinity), (2) physical measurements where applicable (water temperature, well description, etc.), and (3) elemental analyses (U, Al, Br, Cl, Dy, F, Mn, Na, and V). Data from sediment sites include (1) stream water chemistry measurements (pH, conductivity, and alkalinity), and (2) elemental analyses for sediment samples (U, Th, Hf, Al, Ce, Dy, Eu, Fe, La, Lu, Mn, Sc, Sm, Na, Ti, V, and Yb). Sample site descriptors (stream characteristics, vegetation, etc.) are also tabulated. A real distribution maps, histograms, and cumulative frequency plots for most elements and for U/Th and U/Hf ratios are included. Key data from stream water sites include (1) water quality measurements (pH, conductivity, and alkalinity) and (2) elemental analyses (U, Al, Br, Cl, Dy, F, Mg, Mg, Na, and V). Uranium concentrations in the sediments range from 0.30 to 43.40 ppM with a mean of 3.03 ppM. A cluster of high log (U/Th+Hf) ratios appear in the southeastern portion of the quadrangle. The U x 1000/conductivity ratio in surface water is high in this same area

Radionuclide and metal contamination in pit lakes in former U mining sites in Central Asia

Energy Technology Data Exchange (ETDEWEB)

Skipperud, L.; Rosseland, B.O.; Heier, L.S.; Salbu, B. [Centre for Environmental Radioactivity - CERAD, Norwegian University of Life Sciences - NMBU (Norway); Stegnar, P. [Josef Stefan Institute (Slovenia); Yunusov, M. [IA Vostokredmet (Tajikistan); Burkitbaev, L.M. [Al-Farabi Kazakh National University (Kazakhstan)

2014-07-01

The uranium mining industry in the USSR was established in the late 1940's - early 1950's in the former Soviet Republics of Kazakhstan, Kyrgyzstan, Tajikistan and Uzbekistan as part of the nuclear weapon program. In most countries, uranium mining is considered a hazardous step of nuclear materials production, both in terms of radiation doses and in the number of people affected. Key problems have been associated with the transport of uranium and its daughters in aquatic and terrestrial ecosystems, where radionuclides are transferred from air, water, and soils into plants, fish/animals and finally to man. In this paper, special attention is paid to the assessment of radionuclides and metals in Central Asian Pit Lakes. Field works to Kurday, Kasakhstan, and Taboshar, Tajikistan, Pit Lakes have been performed. In addition to sampling of water, fish, sediments, and vegetation, in situ fractionation of water were achieved. The concentrations of U and associated trace metals were enriched in the Kurday Pit Lake and in the artesian water at the Kurday site (U exceeding the WHO guideline value for drinking water), and decreased downstream from the mining area. Uranium, As, Mo and Ni were predominantly present as mobile low molecular mass species in waters, while a significant proportion of Cr, Mn and Fe were associated with colloids and particles. Due to oxidation of divalent iron in the artesian ground water upon contact with air, Fe served as scavenger for other elements, and peak concentrations of U, Ra-isotopes, As and Mn were seen. The U concentrations in water from Taboshar Pit Lake (2.0 mg U/L) were higher than waters collected in other areas in Tajikistan. The Pit Lake and the stream water from the tailing mountain were also characterized by elevated concentrations of As, Mo, Mn and Fe, exceeding the WHO recommended values for drinking water. Uranium, As, Mo and Ni were present as low molecular mass species in the waters, and are therefore considered

Modeling and management of pit lake water chemistry 1: Theory

International Nuclear Information System (INIS)

Castendyk, D.N.; Eary, L.E.; Balistrieri, L.S.

2015-01-01

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

Influence of climatic conditions and elevation on the spatial distribution and abundance of Trypodendron ambrosia beetles (Coleoptera: Curculionidae: Scolytinae) in Alaska

Science.gov (United States)

Robin M. Reich; John E. Lundquist; Robert E. Acciavati

2014-01-01

The objective of this study was to model the influence of temperature and precipitation on the distribution and abundance of the ambrosia beetles in the genus Trypodendron. Although these beetles do not attack and kill healthy trees, their gallery holes and accompanying black and gray stain associated with symbiotic ambrosial fungi can cause significant economic losses...

Challenges with modifications of the McClean Lake mill to process midwest ore

International Nuclear Information System (INIS)

Nguyen, T.T.; Backham, L.

2010-01-01

Midwest is a unique uranium deposit with exceptionally high arsenic content. The ore body is located 17 km west of the McClean Lake operation. The McClean Lake mill will be modified to process Midwest ore and handle solid wastes from the Midwest water treatment plant. This paper describes the modifications required of the McClean Lake mill, process challenges associated with treatment of the arsenic, and the possibility of recovering nickel and cobalt as a by-product. It also reviews the complexity in the design of the Midwest water treatment facility which incorporates reverse osmosis technology with conventional physical-chemical water treatment. (author)

Final report of the AECL/SKB Cigar Lake analog study

International Nuclear Information System (INIS)

Cramer, J.J.

1994-07-01

The Cigar Lake uranium deposit is located in northern Saskatchewan, Canada. The 1.3-billion-year-old deposit is located at a depth of about 450 m below surface in a water-saturated sandstone at the unconformity contact with the high-grade metamorphic rocks of the Canadian Shield. The uranium mineralization, consisting primarily of uraninite (UO 2 ), is surrounded by a clay-rich halo in both sandstone and basement rocks, and remains extremely well preserved and intact. The average grade of the mineralization is ∼ 8 wt.% U; locally grades are as high as ∼ 55 wt.%U. The Cigar lake deposit has many features that parallel those being considered within the Canadian concept for disposal of nuclear fuel waste. Specifically, the deposit provides analog information relevant to the stability of UO 2 fuel waste, the performance of clay-based barriers, radionuclide migration, colloid formation, radiolysis, fission-product geochemistry and general aspects of water-rock interaction. The main geochemical 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. Since 1984, through cooperation from the owners of the Cigar lake deposit, analog studies have been conducted. AECL, with support from Ontario Hydro under the auspices of the CANDU Owners Group, initiated international participation in 1989 through collaboration with the Swedish Nuclear Fuel and Waste Management Company (SKB) and, more recently, with the Los Alamos National Laboratory (LANL). This report gives the results of the various studies carried out during the 3-year collaboration between AECL and SKB, as well as a summary of the LANL study. It provides detailed information on the generated databases and models, and integrates this information into conclusions for use in safety assessment of the Canadian, Swedish and United States disposal concepts. 15 refs., 25 figs., 55 tabs

Radioactive material in the West Lake Landfill: Summary report

International Nuclear Information System (INIS)

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

Elevated Uranium in Aquifers of the Jacobsville Sandstone

Science.gov (United States)

Sherman, H.; Gierke, J.

2003-12-01

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

An innovative jet boring mining method available for the high grade uranium ore underground deposits

International Nuclear Information System (INIS)

Narcy, J.L.

1996-01-01

An innovative mining method, based on the capability of a high pressure water jet to desaggregate rock, has been conceived and tested with success at the highest grade uranium ore deposit in the world, the Cigar Lake deposit in Saskatchewan, Canada. 113 tonnes of ore at 13% U were mined out by a new jet-boring mining method operated on a semi-industrial basis, in 1992 during the test mining program of Cigar Lake Project. (author). 9 figs

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.

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

International Nuclear Information System (INIS)

Sachdev, S.C.

1980-01-01

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

Physical characteristics and solubility of long-lived airborne particulates in uranium producing and manufacturing facilities Phase IV - Part III

International Nuclear Information System (INIS)

Robertson, R.; Stuart, D.C.

1995-08-01

The rates of dissolution in simulated lung fluid of uranium, thorium-230, radium-226 and lead-210 from six aerosol samples associated with mining operations at Cluff Lake, Saskatchewan were determined. Parallel studies were carried out for uranium aerosol samples collected directly on open-face filters at the Port Hope refinery and from four aerosol samples generated in the laboratory from yellowcake dusts obtained from the Blind River mill in Ontario. Bulk dusts were collected from surfaces in workplace locations. These dusts were resuspended in the laboratory and collected on glass fibre substrates using cascade impactor sampling methods. Two particle size fractions, less than 7 microns and 7-10 microns were collected. In all, 18 samples were subjected to parallel extractions by simulated lung fluid under continuous flow, at 37 deg C at pH 7.4, over a period of 66 days. For each extraction, 10 lung fluid fractions were collected at predetermined intervals and analyzed for uranium to estimate uranium dissolution rates as a function of time. For the Cluff Lake ore dust samples, analyses and dissolution rates estimates for thorium-230, radium-226 and lead-210 were also performed. The samples taken from Cluff Lake were found to be relatively insoluble. Uranium dissolution rates of about 20% were measured over 66 days. No measurable Th-228 dissolution was found during the experiments. Ra-226 and Pb-210 were most soluble as a fine particulate (less than 7 μm), with complete dissolution for some samples. Aerosol samples from Blind River and Port Hope were more readily soluble (complete dissolution over 66 days). The Blind River aerosols dissolved more slowly than the Port Hope aerosols. In both cases, the majority of the dissolution occurred within the first week. There was no effect of particle size on dissolution rate. (author). 12 refs., 6 tabs., 1 fig

Uranium-series dating of some lake and dune deposits in south-east Australia

International Nuclear Information System (INIS)

Herczeg, A.L.

1987-01-01

A correction scheme developed over many years was used to obtain reliable dates for impure carbonates and gypsum from uranium disequilibrium analyses. The materials analyzed thus far and their sources are described. The results indicated that reliable dating can be obtained provided that there is no post-depositional alteration in the sample and that sufficient uranium is present. The object is to investigate further sites in order to reconstruct palaeohydrology and environments in Australia over the last 400000 years. 4 refs

Environmental assessment of remedial action at the inactive uraniferous lignite ashing sites at Belfield and Bowman, North Dakota

International Nuclear Information System (INIS)

1993-09-01

The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 authorized the US Department of Energy (DOE) to perform remedial actions at Belfield and Bowman inactive lignite ashing sites in southwestern North Dakota to reduce the potential public health impacts from the residual radioactivity remaining at the sites. The US Environmental Protection Agency (EPA) promulgated standards (40 CFR 192) that contain measures to control the residual radioactive materials and other contaminated materials, and proposed standards to protect the groundwater from further degradation. Remedial action at the Belfield and Bowman sites must be performed in accordance with these standards and with the concurrence of the US Nuclear Regulatory Commission (NRC) and the state of North Dakota. The Belfield and Bowman designated sites were used by Union Carbide and Kerr-McGee, respectively, to process uraniferous lignite in the 1960s. Uranium-rich ash from rotary kiln processing of the lignite was loaded into rail cars and transported to uranium mills in Rifle, Colorado, and Ambrosia Lake, New Mexico, respectively. As a result of the ashing process, there is a total of 158,400 cubic yards (yd 3 ) [121,100 cubic meters (m 3 )] of radioactive ash-contaminated soils at the two sites. Windblown ash-contaminated soil covers an additional 21 acres (8.5 ha) around the site, which includes grazing land, wetlands, and a wooded habitat

Green ambrosia for Soil- Dry Cow Dung Powder: Rhexistasy to Biostasy

Science.gov (United States)

Bagla, Hemlata; Barot, Nisha

2013-04-01

"Greener ambrosia for Soil - Dry cow dung powder: Rhexistasy to Biostasy" Pedosphere, the soil with its biotic and abiotic component, is produced by lithosphere`s interactions with atmosphere, hydrosphere and biosphere. The theory of Biorhexistasy proposed by pedologist H. Erhart [1], describes two crucial climatic phases of soil i.e. Biostasy, period of soil formation and Rhexistasy, periods of soil erosion. Humus, the organic matter in soil, permits better aeration, enhances the absorption and releases nutrients, and makes the soil less susceptible to leaching and erosion [2], thus the agent of soil`s vitality. Mismanagement of soil, leads to the degradation of millions of acres of land through erosion, compaction, salinization and acidification. Among these threats salinity is a major abiotic stress reducing the yield of wide variety of crops all over the world [3]. It is been proved that Humic Acid (HA) treatment can ameliorate the deleterious effects of salt stress by increasing root growth, altering mineral uptake, and decreasing membrane damage, thus inducing salt tolerance in plants [4]. HA can be inexpensively incorporated into soils via different biowastes. Dry cow dung powder (DCP), is naturally available bio-organic, complex, polymorphic humified fecal matter, enriched with minerals, carbohydrates, fats, proteins, bile pigments, aliphatic - aromatic species such as HA, Fulvic Acid (FA) etc [5]. The microbial consortium enables DCP with considerable potentials for biodegradation and biotransformation of even saline soil and further contributes to many biogeochemical processes, boosting humus content of soil. Due to unambiguous biological, microbiological as well as chemical inert properties of DCP, it has been successfully utilized as a fertilizer and soil conditioner since ages in India, one of the leading agrarian countries of the world. Thus we summarize that DCP is one of the best contenders for the biostasy and desaliner of soil, aptly, soil

Australia's Uranium and thorium resources and their global significance

International Nuclear Information System (INIS)

Lambert, I.B.; McKay, A.; Miezitis, Y.

2006-01-01

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

Cleaning-up abandoned uranium mines in Saskatchewan's North

International Nuclear Information System (INIS)

Schramm, L.L.

2012-01-01

Thirty-six now-abandoned uranium mine and mill sites were developed and operated on or near Lake Athabasca, in Northern Saskatchewan, Canada, from approximately 1957 through 1964. During their operating lifetimes these mines produced large quantities of ore and tailings. After closure in the 1960's, these mine and mill sites were abandoned with little remediation and no reclamation being done. The governments of Canada and Saskatchewan are now funding the cleanup of these abandoned northern uranium mine and mill sites and have contracted the management of the project to the Saskatchewan Research Council (SRC). The clean-up activity is underway, with work at many of the smaller sites largely completed, work at the Gunnar site well underway, and a beginning made at the Lorado site. This lecture presents an overview of these operations. (author)

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

International Nuclear Information System (INIS)

Bottomley, D.J.

1996-04-01

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 99 Tc. 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

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

International Nuclear Information System (INIS)

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

1977-02-01

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

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

Uranium hydrogeochemical and stream sediment reconnaissance in the San Juan Mountains, Southwest Colorado

Energy Technology Data Exchange (ETDEWEB)

Maxwell, J.C.

1977-02-01

From 1995 sites in the San Juan Mountains area, 1706 water and 1982 sediment samples were collected during June--July 1976 and analyzed for uranium. The area includes the southern third of the Colorado mineral belt which has yielded rich ores of gold, silver, copper, lead, zinc, and molybdenum. The broadly domed mountains are capped by 2500 m of Tertiary volcanics, deeply eroded to expose a Precambrian crystalline core. Adjacent plateaus underlain by Mesozoic sedimentary rocks were included in the reconnaissance. Average value of uranium in water samples from mountains was less than 0.5 ppB, from plateaus was 1 to 2 ppB, from Mancos shale areas exceeded 2 ppB. Anomalous sediment samples, 40 ppM uranium, came from near Storm King Mountain and upper Vallecito Creek. Other anomalous areas, including the Lake City mining district, were well defined by 4 to 30 ppM uranium in sediment and 3 to 30 ppB uranium in water. Anomalous areas not previously reported indicate favorable areas for future exploration.

Uranium hydrogeochemical and stream sediment reconnaissance in the San Juan Mountains, Southwest Colorado

International Nuclear Information System (INIS)

Maxwell, J.C.

1977-02-01

From 1995 sites in the San Juan Mountains area, 1706 water and 1982 sediment samples were collected during June--July 1976 and analyzed for uranium. The area includes the southern third of the Colorado mineral belt which has yielded rich ores of gold, silver, copper, lead, zinc, and molybdenum. The broadly domed mountains are capped by 2500 m of Tertiary volcanics, deeply eroded to expose a Precambrian crystalline core. Adjacent plateaus underlain by Mesozoic sedimentary rocks were included in the reconnaissance. Average value of uranium in water samples from mountains was less than 0.5 ppB, from plateaus was 1 to 2 ppB, from Mancos shale areas exceeded 2 ppB. Anomalous sediment samples, 40 ppM uranium, came from near Storm King Mountain and upper Vallecito Creek. Other anomalous areas, including the Lake City mining district, were well defined by 4 to 30 ppM uranium in sediment and 3 to 30 ppB uranium in water. Anomalous areas not previously reported indicate favorable areas for future exploration

Environmental restoration of uranium mines in Canada: Progress over 52 years

International Nuclear Information System (INIS)

Feasby, D.G.

1997-01-01

In Canada, the technology for disposal of uranium mine wastes and reclamation of mines has evolved over a period of 52 years. Early practice involved dumping untreated wastes into the nearest depression or lake and leaving rock and infrastructure in place. Now, the practice is to deposit chemically-stabilized tailings, waste rock and building rubble into highly engineered waste management facilities or mine openings. Similarly the ''footprint'' of the mining activity has been reduced to a very small area and the site is restored as-close-as-possible to pre-mining status. This paper describes the evolution of disposal and reclamation methods and the criteria which have determined the development path followed. Remediation techniques to bring older and now unacceptable tailings deposits into satisfactory compliance with current regulations are reviewed. Some monitoring results are presented. All of the uranium mines in Elliot Lake, Ontario, a large uranium producer since 1957, are now permanently closed. Considerable progress has been made on decommissioning the tailings areas by developing long term maintenance of water covers on some, and water treatment plants and stable soil covers on the others. The innovative methods being used to develop the water covers are described, along with the challenges remaining. Methods now under development in Saskatchewan for subaqueous deposition of paste tailings for permanent disposal in mined out open pits are also described. This method will provide for the first time, ''walkaway'', meaning no long term monitoring and maintenance will be required

Report on a structural and sedimentological analysis in the uranium province of the Orobic Alps, Italy

International Nuclear Information System (INIS)

Cassinis, G.; Dal Piaz, G.V.; Massari, P.F.

1986-01-01

Detailed structural and sedimentological studies have been conducted in two areas near the Val Vedello uranium mine in northern Italy. These studies indicate that both the Variscan basement (locally called the Orobic basement) and the Permian cover rocks were thrust southward during the Alpine orogeny. Variscan mylonitic zones were rejuvenated during the Alpine orogeny and became fault boundaries for the Permo-Triassic basins. Alpine faults also are related to contemporaneous east-west folds and these faults have displaced Permo-Triassic uranium deposits. Uranium mineralisation is attributed to a Late Permian to Triassic geothermal event which leached uranium from Permian ignimbrites and transported it along Permo-Triassic faults. Detailed mapping indicates that the host sediments formed in an arid, closed basin characterised by alluvial fans and perennial saline lakes. (orig.)

Techniques Currently Used in Uranium Prospecting in Canada

Energy Technology Data Exchange (ETDEWEB)

Little, H. W.; Smith, A. Y. [Geological Survey of Canada, Ottawa, Ont. (Canada)

1969-03-15

The sequence of existing practice in the search for uranium deposits in Canada begins with the establishment of a factual classification of types of uranium deposits and the criteria for recognition of the geological environment favourable to each type. The next step is the careful appraisal of geological maps and reports to determine regions and, more specifically, rock formations in which these criteria exist. Guidelines in the selection of such areas were given in a recent Geological Survey paper by S M. Roscoe. In most areas, once a favourable region or formation is selected, initial field investigation is preceded by an airborne scintillometer or airborne gamma-ray spectrometer survey. Detailed geological mapping is usually done, particularly by the larger companies, with special attention to the cause of anomalies. The form of geological studies is dependent on the type of uranium deposit, in the Elliot Lake area sedimentological studies comprise the mam guidelines in the search for ore whereas structural interpretation is the keynote in such areas as Uranium City. Detailed scintillometer grid surveys on the ground are used subsequently to pinpoint the targets to be surface trenched or diamond drilled. The drilling pattern is also governed by the type of deposit. Down-hole scintillometer probes are used to extrapolate data obtained by more costly chemical assays. Research is being conducted, both by private industry and by the Geological Survey of Canada, into improved design and sensitivity of airborne gamma-ray spectrometry, and airborne magnetometers. The Geological Survey is testing AFMAG equipment, and plans to cover the Uranium City area, where pitchblende-bearing veins are in or close to faults. Geochemical research is being undertaken on the behaviour of uranium ions, in stream sediments, in soils, and in surface waters, relative to their use in prospecting for uranium deposits. Recent analyses for radon in surface waters has shown a closer

Results of uranium hydrogeochemical and stream sediment reconnaissance of the San Juan area, southwestern Colorado

International Nuclear Information System (INIS)

Maxwell, J.C.

1977-01-01

During June-July 1976, 1706 water samples and 1982 sediment samples were collected from 1995 sites in the San Juan Mountains area and analyzed for uranium. The area includes the southern third of the Colorado mineral belt which has yielded rich ores of gold, silver, copper, lead, zinc, and molybdenum. The broadly domed mountains are capped by 2500 m of Tertiary volcanics, deeply eroded to expose a Precambrian crystalline core. Adjacent plateaus underlain by Mesozoic sedimentary rocks were included in the reconnaissance. Average value of uranium in water samples from mountains was less than 0.5 ppb, from plateaus was 1 to 2 ppb, and from Mancos shale areas exceeded 2 ppb. Anomalous sediment samples, 40 ppM uranium, came from near Storm King Mountain and upper Vallecito Creek. Other anomalous areas, including the Lake City mining district, were well defined by 4 to 30 ppM uranium in sediment and 3 to 30 ppB uranium in water. Above-average concentrations of uranium not previously reported indicate areas favorable for detailed exploration

The relationship between uranium distribution and some major crustal features in Canada

International Nuclear Information System (INIS)

Darnley, A.G.

1982-01-01

The availability of reconnaissance scale geochemical maps for large areas of Canada enables spatial associations between major crustal structures and surface uranium content to be identified. Maps of the distribution of uranium for an area greater than 2 million km 2 compiled from airborne gamma-ray spectrometry data are supplemented by maps for uranium, based on stream and lake sediment and some bore hole sampling. These are examined in relation to gravity, aeromagnetic and geological maps. The radioelement distribution can be related in detail to exposed bedrock and surface geology, but in addition there is evidence of the control of uranium distribution by major structural features which are marked by granitoids containing elevated levels of radioelements; several of these granitoids are associated with large negative Bouguer gravity anomalies. The distribution of such granitoids appears to be related to 'megashears', as in the case of the South Mountain batholith in Nova Scotia, or zones of tension. A belt of uranium enrichment, the Athabasca axis which is characterized by uraniferous granitoids with negative Bouguer gravity anomalies and associated tension faulting extends 2500 km northeastward from Edmonton, Alberta to the Melville Peninsula. This structure passes under the Athabasca basin which contains many large uranium deposits. (author)

Geological characteristics of the main deposits in the world. Geological characteristics of French uranium deposits; their consequences on the different stages of valorisation. The uranium market; Caracteres geologiques des principaux gisements du monde. Caracteres geologiques des gisements francais d'uranium; leurs consequences dans les differents stades de la mise en valeur. Le marche de l'uranium

Energy Technology Data Exchange (ETDEWEB)

Gangloff, A.; Lenoble, A.; Mabile, J.

1958-07-15

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

Uranium Mill Tailings Remedial Action Program. Annual status report

International Nuclear Information System (INIS)

1983-12-01

The FY 1983 project accomplishments are: completed the Remedial Action Plan and Phase I engineering design for the Canonsburg processing site; completed remedial action on an additional 52 vicinity properties and the inclusion of an additional 303 properties in the Uranium Mill Tailings Remedial Action Project; executed cooperative agreements with four states and the Navajo Nation; published the draft environmental impact statement for Salt Lake City site; and issued the approved Project Plan

North American Lauraceae: Terpenoid Emissions, Relative Attraction and Boring Preferences of Redbay Ambrosia Beetle, Xyleborus glabratus (Coleoptera: Curculionidae: Scolytinae)

OpenAIRE

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 mem...

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

International Nuclear Information System (INIS)

Gangloff, A.; Lenoble, A.; Mabile, J.

1958-07-01

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

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

International Nuclear Information System (INIS)

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

1978-02-01

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

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)

Ronqui, Leilane B.; Nasciment, Marcos R.L. do; Roque, Claudio V.; Bruschi, Armando; Borba Junior, Palvo J.; Nascimento, Heliana A. F. do; Almeida, Tito C.M. de

2013-01-01

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)

Minimizing the risk and impact of uranium hexafluoride production

International Nuclear Information System (INIS)

Clark, D.R.; Kennedy, T.W.

2010-01-01

Cameco Corporation's Port Hope conversion facility, situated on the shore of Lake Ontario in the Municipality of Port Hope, Ontario, Canada, converts natural uranium trioxide (UO_3) into uranium dioxide (UO_2) or natural uranium hexafluoride (UF_6). Conversion of UO_3 to UF_6 has been undertaken at the Port Hope conversion facility since 1970 and is currently carried out in a second-generation plant licensed to annually produce 12,500 tonnes U as UF_6. Consistent with Cameco's vision, values and measures of success, Cameco recognizes safety and health of its workers and the public, protection of the environment, and the quality of our processes as the highest corporate priorities. Production of UF_6 in a brownfield urban setting requires a commitment to design, build and maintain multiple layers of containment (defence-in-depth) and to continually improve in all operational aspects to achieve this corporate commitment. This paper will describe the conversion processes utilized with a focus on the cultural, management and physical systems employed to minimize the risk and impact of the operation. (author)

SNG-logs at the Bagsvaerd Lake

International Nuclear Information System (INIS)

Korsbech, U.

1992-11-01

Spectral Natural Gamma-logs (SNG) were taken in old boreholes around Bagsvaerd Lake (Zealand). The purpose of this investigation was to clarify the geologic/lithologic conditions in this region and the potential risks of waste penetration into ground water. Relationship curves for thorium, uranium and potassium concentrations are given. Some special logs which can be useful for evaluating concentration variations or transition forms among various lithological layers are collected. Appendices contain technical information on the boreholes and discussion of differences between results of SNG-logging and the conventional gamma-logging. (EG)

Scope of work-supplemental standards-related fieldwork - Salt Lake City UMTRA Project Site, Salt Lake City, Utah

International Nuclear Information System (INIS)

1996-01-01

This scope of work governs the field effort to conduct transient in situ (hereafter referred to by the trademark name HydroPunch reg-sign) investigative subsurface logging and ground water sampling, and perform well point installation services at the U.S. Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project site near Salt Lake City, Utah. The HydroPunch reg-sign and well point services subcontractor (the Subcontractor) shall provide services as stated herein to be used to investigate the subsurface, collect and analyze ground water samples, and install shallow well points

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.

National uranium resource evaluation, Las Vegas Quadrangle, Nevada, Arizona, and California

International Nuclear Information System (INIS)

Johnson, C.; Glynn, J.

1982-03-01

The Las Vegas 1 0 x 2 0 quadrangle, Nevada, Arizona, and California, contains rocks and structures from Precambrian through Holocene in age. It lies within the Basin and Range physiographic province adjacent to the westernmost portion of the Colorado Plateau. Miocene nonmarine sedimentary rocks of the Horse Spring Formation contain in excess of 100 tons U 3 O 8 in deposits at a grade of 0.01% or greater, and therefore meet National Uranium Resource Evaluation base criteria for uranium favorability. One favorable area lies in the South Virgin Mountains at the type locality of the Horse Spring Formation, although the favorable environment extends into the unevaluated Lake Mead National Recreation Area and Desert National Wildlife Range. Environments within the Las Vegas Quadrangle considered unfavorable for uranium include the Shinarump Conglomerate member of the Triassic Chinle Formation, Mesozoic sediments of the Glen Canyon Group, Precambrian pegmatites, Pliocene and Quaternary calcrete, Laramide thrust faults, and a late Precambrian unconformity

Application of solution-mineral equilibrium chemistry to solution mining of uranium ores

International Nuclear Information System (INIS)

Riese, A.C.; Propp, C.J.

1980-01-01

Modern methods of uranium solution mining are typically accompanied by gains and losses of mass through reagent consumption by rock-forming minerals, with subsequent formation of clay minerals, gypsum, carbonates, and iron oxyhydroxides. A systematic approach to alleviate such problems involves the application of leach solutions that are in equilibrium with the host-rock minerals but in disequilibrium with the ore-forming minerals. This partial equilibrium can be approximated by solution-composition adjustments within the systems K 2 O-Al 2 O 3 SiO 2 -H 2 O and Na 2 O 3 -Al 2 O 3 SiO 2 -H 2 O. Uranium ore containing 0.15 percent U 3 O 8 from the Gulf Mineral Resources Corporation's Mariano Lake mine, the Smith Lake district of the Grants mineral belt, was collected for investigation. Presented are a theoretical evaluation of leachate data and an experimental treatment of the ore, which contained mainly K-feldspar, plagioclase feldspar, and quartz (with lesser amounts of micas, clay minerals, and organic carbonaceous material). Small-scale (less than or equal to 1 kg) column-leaching experiments were conducted to model the results of conventional leaching operations and to provide leachate solutions that could be compared with solutions calculated to be in equilibrium with the matrix minerals. Leach solutions employed include: 1) sulfuric acid, 2) sodium bicarbonate, and 3) sulfuric acid with 1.0 molal potassium chloride. The uranium concentrations in the sodium-bicarbonate leach solution and the acid-leach solution were about a gram per liter at the termination of the tests. However, the permeability of the ore in the acid leach was greatly reduced, owing to the formation of clay minerals. Uranium solubility in the leach column stabilized with the potassium-chloride solution was calculated from leachate compositions to be limited by the solubility of carnotite

Observations on stake holder confidence related to uranium mine waste management in the elliot lake region

International Nuclear Information System (INIS)

MacDonald, G.

2003-01-01

G. MacDonald, representing the Township of the North Shore and the Standing Environmental Committee (SEC) of the Serpent River Watershed, stated that she is a stakeholder living downstream from 175 million tonnes of acid-generating and radioactive uranium mine tailings. Public confidence in the Elliot Lake region is influenced by past mining issues: worker health concerns and difficulties in obtaining compensation; myriad observations of radium uptake; drinking water contamination issues and inequitable quality standards adverse to the Serpent River First Nation; loss of land use. Government failed to set aside funds for local monitoring of the decommissioned mining region, or to involve citizens in decisions as recommended by the Kirkwood Panel. These failures represent betrayals of trust and furthermore give public confidence little chance to improve. In these circumstances, the affected community has given attention on their own to mid- and long-term issues. At issue is not the current funding or management of the waste storage sites, but rather, creating and maintaining local knowledge and competence to monitor their management over the coming decades and generations. Concerned members of the community note that the federal government 'has done nothing long-lasting to ensure confidence', on this level. They highlight the importance of questions like: 'Do I have the knowledge to act in my best interest?' and 'Who can I trust to protect my interest?' - and have set out to answer them. (author)

Information from uranium and thorium isotopes recorded in lake bottom sediment - Lake Kawaguchi. Attempt to evaluate environmental changes

International Nuclear Information System (INIS)

Sakaguchi, A.; Yamamoto, M.; Shimizu, T.; Sasaki, K.; Koshimizu, S.

2003-01-01

Lake sediments, as well as ice cores and marine sediments, have been used to reveal past environmental changes caused by both natural and artificial events with local and global scales. Particles in the lake originate from soil and other suspended matter which are carried in from the inflowing water or from direct discharge (lithogenous particles), and they are also formed in the lake as a result of the growth, metabolism and death of plants and animals (autogenous particles). The settling particles contain U and Th isotopes due to lithogenous particles (soil), and adsorbed U to the particles. Thorium has an exceedingly low solubility in water and is very strongly adsorbed onto particles. If we can distinguish these two different components in the mixture of U due to lithogenous particles themselves and adsorption fractions, the former might provide useful information on past environmental changes by natural events, while the latter information on past environmental changes by artificial events. In this paper, we aimed to test the above hypothesis using data on U and Th isotopes of sediment cores (0- ca. 40 cm depth, covering periods of past several hundred years) from 3 points in Lake Kawaguchi of Fuji-Goko in Japan. By using model equation and results obtained from analysis, we distinguished U due to lithogenous and autogenous particles. And these depth profiles were compared with changes in the rainfall during the period of 1933 - 2001. Although the changes in the 238 U/ 232 Th ratios with depth for lithogenous particles and rainfall do not fluctuate synchronously, some parts of depth coincided with each other. The results suggest strongly that variation in the U and Th isotopic ratios separated by model might be helpful in tracing the past environmental changes in regional scale. To check the usefulness of this method, physical and chemical data such as grain size, grain density, water content and biogenic SiO 2 in the sediment will be further compared with the

Measurement of uranium and thorium in marine sediments

International Nuclear Information System (INIS)

Denden, Ibtihel

2009-01-01

Lakes, oceans and seas accumulate sediments. These sediments constitute a file of the last environmental conditions going up in some cases to thousands of years. In our study, we consulted this file by analyzing radioisotopes of Uranium and Thorium that are included in a carrot of marine sediment taken from the south of Mediterranean Sea. When we applied the technique developed by the maritime environment's laboratory of Monaco, we found spectra with bad resolutions. For this reason, the optimization of this protocol appeared necessary. (Author).

Microbes: uranium miners, money makers, problem solvers

Energy Technology Data Exchange (ETDEWEB)

Williamson, A.L., E-mail: awilliamson@mirarco.org [MIRARCO, Sudbury, ON (Canada); Laurentian Univ., Sudbury, ON (Canada); Payne, R.; Kerr, F. [Pele Mountain Resources Inc., Toronto, ON (Canada); Hall, S. [Laurentian Univ., Sudbury, ON (Canada); Spiers, G.A. [MIRARCO, Sudbury, ON (Canada); Laurentian Univ., Sudbury, ON (Canada)

2010-07-01

Bioleaching, the microbial dissolution of minerals, is potentially useful in exploiting a variety of ore deposits, including the lower-grade uraniferous quartz-pebble conglomerate beds of the Quirke Syncline, Elliot Lake, Ontario. The metabolism of chemolithotropic bacterium Acidithiobacillus ferrooxidans is dependent on its ability to derive energy and reducing power from the oxidation of ferrous iron. The characteristics of this bacterium, in particular the ability to oxidize both iron and sulphur with an associated high tolerance of low acidity, allow the organism to contribute significantly to bioleaching processes. Under ideal conditions, A. ferrooxidans promotes the oxidation of iron-containing sulphide ore materials, breaking their crystal structure and promoting the dissolution of iron, base metals, as well as uranium, rare earth elements and associated elements of toxicological interest such as arsenic and selenium. The current study documents an overview of the recovery of uranium and rare earth elements to solution, plus investigates the acid generating potential of the solid residues from a series of environmentally controlled, biologically-mediated uranium ore extraction experiments. The findings will be used in the design of larger scale bioleaching experiments to further assess the potential for success of bioleaching as a metallurgical extraction technique potentially leading to minimum maintenance decommissioning strategies for the ore deposits of the Quirke Syncline. (author)

Microbes: uranium miners, money makers, problem solvers

International Nuclear Information System (INIS)

Williamson, A.L.; Payne, R.; Kerr, F.; Hall, S.; Spiers, G.A.

2010-01-01

Bioleaching, the microbial dissolution of minerals, is potentially useful in exploiting a variety of ore deposits, including the lower-grade uraniferous quartz-pebble conglomerate beds of the Quirke Syncline, Elliot Lake, Ontario. The metabolism of chemolithotropic bacterium Acidithiobacillus ferrooxidans is dependent on its ability to derive energy and reducing power from the oxidation of ferrous iron. The characteristics of this bacterium, in particular the ability to oxidize both iron and sulphur with an associated high tolerance of low acidity, allow the organism to contribute significantly to bioleaching processes. Under ideal conditions, A. ferrooxidans promotes the oxidation of iron-containing sulphide ore materials, breaking their crystal structure and promoting the dissolution of iron, base metals, as well as uranium, rare earth elements and associated elements of toxicological interest such as arsenic and selenium. The current study documents an overview of the recovery of uranium and rare earth elements to solution, plus investigates the acid generating potential of the solid residues from a series of environmentally controlled, biologically-mediated uranium ore extraction experiments. The findings will be used in the design of larger scale bioleaching experiments to further assess the potential for success of bioleaching as a metallurgical extraction technique potentially leading to minimum maintenance decommissioning strategies for the ore deposits of the Quirke Syncline. (author)

On the geology of the uranium mineralization in the Swiss Alps

International Nuclear Information System (INIS)

Gillieron, F.

1988-01-01

Numerous radiometric anomalies and several uranium occurrences were found in the Swiss Alps by systematic prospecting of selected areas carried out between 1957 and 1984. Most of the uranium indications lie in a rather narrow belt that follows roughly the valleys of the Rhone und of the Rhine Anterior, from Martigny onto Ilanz and extending northwards towards the Lake of Walenstadt. The uranium occurrences were found in the following geological environments: - permocarboniferous continental, variably metamorphosed series, belonging either to the formation of the 'Verrucano' or to the Penninic St. Bernhard nappe; - muscovite-chlorite-albite gneisses belonging to the pre-Westphalian basement of the St. Bernhard nappe; - muscovite-chlorite gneisses and phyllites of the Hercynian Tavetsch massiv; - muscovite-biotite gneisses within the southern border of the Aar massif; - Vallorcine granite of the Auguilles-Rouges massiv and polymetamorphic biotite gneisses along its northwestern contact zone. The possible geological (or 'in situ') resources are estimated to be 50-250 tonnes uranium in each one of the investigated mineralization zones of some importance; the respective estimated grades are 50-250 ppm U. Therefore the occurrences are actually of no economic value. (author) 25 figs., 1 tab., refs

Quantitative analysis of the taxation of uranium mines in Australia and Canada

International Nuclear Information System (INIS)

Barnett, D.W.; Anderson, D.L.

1984-01-01

The degree of neutrality of a tax policy is a gauge of how willing a government is to share in the risk of mineral development. This paper analyzes the practical characteristics of the uranium taxation policies of the Northern Territory in Australia and Saskatchewan in Canada. It superimposes these two policies on a large Australian uranium mine, based on the Ranger mine, and on a slightly larger Canadian mine, based on the Key Lake mine. The analysis focuses on the impact on the net-present-value of the producers' returns, the sharing of economic rent between the arms of government and the producer, and on the apparent neutrality of the tax policies. 24 references, 6 figures

Uranium exploration (2004-2014): New discoveries, new resources

International Nuclear Information System (INIS)

Polack, C.

2014-01-01

The last decade has demonstrated the dynamic of the mining industry to respond of the need of the market to explore and discover new deposits. For the first time in the uranium industry, the effort was conducted not only by the majors but by numerous junior mining companies, more than 800 companies where involved. Junior miners introduced new methodologies, innovations and fresh approach. Working mainly on former prospects of the 70’s and 80’s they discovered new deposits, transformed historical resources into compliant resources and reserves and developed new large resources in Africa, North America and Australia. In Australia, the Four Mile, Mt Gee, Samphire (SA), Mount Isa (Qld), Mulga Rock, Wiluna-Lake Maitland, Carley Bore-Yanrey-Manyingee (WA) projects were all advanced to compliant resources or reserves by junior mining companies. In Canada, activity was mainly focused on Athabasca basin, Newfoundland and Québec, the results are quite amazing. In the Athabasca 2 new deposits were identified, Roughrider and Patterson South Lake, Whilst in Québec the Matouch project and in New Foundland the Michelin project are showing good potential. In Namibia, alaskite and surficial deposits, extended the model of the Dalmaradian Central belt with the extension of rich alaskite of Z20, Husab, Omahola and large deposits of Etango and Norasa. A new mine commenced production Langer Heinrich and two are well advanced on way to production: Trekkopje and Husab. The ISL model continues its success in Central Asia with large discoveries in Mongolia and China. Europe has been revisited by some juniors with an increase of resources in Spain (Salamanca) and Slovakia (Kuriskova). Some countries entered into the uranium club with maiden resources namely Mali (Falea), Mauritania and Peru (Macusani caldeira). The Karoo formation revitalised interest for exploration within Paraguay, South Africa (Rieskuil), Botswana (Lethlakane), Zambia (Mutanga, Chirundu) and the exploitation

Uranium

International Nuclear Information System (INIS)

Hamdoun, N.A.

2007-01-01

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.

Uranium extraction from gold-uranium ores

Energy Technology Data Exchange (ETDEWEB)

Laskorin, B.N.; Golynko, Z.Sh.

1981-01-01

The process of uranium extraction from gold-uranium ores in the South Africa is considered. Flowsheets of reprocessing gold-uranium conglomerates, pile processing and uranium extraction from the ores are presented. Continuous counter flow ion-exchange process of uranium extraction using strong-active or weak-active resins is noted to be the most perspective and economical one. The ion-exchange uranium separation with the succeeding extraction is also the perspective one.

Hydrology of uranium deposits in calcretes of western Australia

International Nuclear Information System (INIS)

Gaskin, A.J.; Butt, C.R.M.; Deutscher, R.L.; Horwitz, R.C.; Mann, A.W.

1981-01-01

Carnotite is the principal uranium mineral occurring in the calcreted trunk valleys of the ancient drainage system which extends over 400,000 sq km of south-western Australia. The calcretes, accumulations of calcium and magnesium carbonates up to 100 km long, 5 km wide, and 20 m thick, are discontinuous in character but act as aquifers for groundwaters of relatively low salinity that flow sluggishly to playa lakes. Catchment basins draining large areas of Precambrian granitic rocks can yield up to 200 parts per billion of uranium in the oxidizing environment of the water at shallow depth near the base of the calcretes. Where the product of the concentrations of active ion species of uranium, vanadium, and potassium exceeds the solubility product of carnotite, this mineral precipitates in fissures or between the carbonate and clay particles. Vanadium appears to be generally deficient in the upper levels of the aquifers; however, where it has been supplied at the required concentration from deeper reduced waters, forced up, for example, by a bar of resistant bedrock, carnotite mineralization has occurred. The incongruent dissolution of carnotite liberates vanadium preferentially. Some carnotite deposits currently are being leached and redeposited downstream. Where calcrete channels reach salt lakes, great increases in the activity of calcium and potassium promote further carnotite deposition by the decomplexing of uranyl carbonate complexes carried down the aquifers. Many areas of carnotite mineralization are now known. The largest, at Yeelirre, contains 46,000 MT of U 3 O 8 at an average grade of 0.15%. Extraction from the ore is hampered by the carbonate content and the presence of illite-montmorillonite clay phases, but alkaline leach techniques are practicable. An appreciable proportion of the carnotite, in an extremely fine-grained form, can be associated with the clay fraction

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

International Nuclear Information System (INIS)

1977-11-01

Finland covers an area of 337,000 skm. One third of the country lies north of the northern polar circle. 31,613 skm are covered by lakes. 71% of the landscape are covered by coniferous -wood. Climatlcal conditions are continental. The topography of the country is gently rolling with highest elevations of 300 m in the northern part. The most interesting geological units for uranium are Karelian, marginal meta-sediments, mainly quarzites and conglomerates but also schists. These schists are intruded by orogenlc plutonic rocks which are 1800-My-old. Potassium granites are common adjacent to the contact of the Pre-karelian basement (2500 My). In addition to these geological environment uranium and thorium minerals have been found in a large carbonatite in northern Finland, which is explored now

Method for converting uranium oxides to uranium metal

International Nuclear Information System (INIS)

Duerksen, W.K.

1988-01-01

A method for converting uranium oxide to uranium metal is described comprising the steps of heating uranium oxide in the presence of a reducing agent to a temperature sufficient to reduce the uranium oxide to uranium metal and form a heterogeneous mixture of a uranium metal product and oxide by-products, heating the mixture in a hydrogen atmosphere at a temperature sufficient to convert uranium metal in the mixture to uranium hydride, cooling the resulting uranium hydride-containing mixture to a temperature sufficient to produce a ferromagnetic transition in the uranium hydride, magnetically separating the cooled uranium hydride from the mixture, and thereafter heating the separated uranium hydride in an inert atmosphere to a temperature sufficient to convert the uranium hydride to uranium metal

High temperature chlorination of uranium and some radionuclides from rich sulphide ores

International Nuclear Information System (INIS)

Mahdy, M.A.

1992-01-01

This work is concerned with the application of the high temperature chlorination technique upon a sulphide-rich uranium ore from elliot lake, ontario, canada. The purpose is to find a substitute to conventional sulphuric acid leaching which involves both acid drainage and radionuclide dissolution problems. Test work has therefore been directed towards studying some relevant factors of chlorination beside the effect of a number of additives

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

International Nuclear Information System (INIS)

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

1983-01-01

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

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)

The Canadian Nuclear Safety Commission regulatory process for decommissioning a uranium mining facility

International Nuclear Information System (INIS)

Scissons, K.; Schryer, D.M.; Goulden, W.; Natomagan, C.

2002-01-01

The Canadian Nuclear Safety Commission (CNSC) regulates uranium mining in Canada. The CNSC regulatory process requires that a licence applicant plan for and commit to future decommissioning before irrevocable decisions are made, and throughout the life of a uranium mine. These requirements include conceptual decommissioning plans and the provision of financial assurances to ensure the availability of funds for decommissioning activities. When an application for decommissioning is submitted to the CNSC, an environmental assessment is required prior to initiating the licensing process. A case study is presented for COGEMA Resources Inc. (COGEMA), who is entering the decommissioning phase with the CNSC for the Cluff Lake uranium mine. As part of the licensing process, CNSC multidisciplinary staff assesses the decommissioning plan, associated costs, and the environmental assessment. When the CNSC is satisfied that all of its requirements are met, a decommissioning licence may be issued. (author)

Using geological information to develop new exploration project for uranium deposits in Southern Africa

International Nuclear Information System (INIS)

Takahashi, Osamu

1992-01-01

Unconformity related uranium deposits which contain a large amount of resources with higher grades will be economically superior to other types of deposits. This paper presents the integrated use of geological information, which includes compilation data for the Precambrian geology in southern Africa and selected structural geologic data for some analogues of unconformity related uranium deposit in Canada (e.g. Key Lake deposit in Athabasca Basin) and the Precambrian rock hosted uranium deposit in Africa (e.g. Oklo-Munana, Rossing, Shinkolobwe and Dome deposits). Finally, some favourable geological terrains for unconformity related uranium deposit and the Precambrian rock hosted uranium deposit were selected on the basis of geological information. Further significant discoveries are likely in the following geological terrains. 1. Both the unconformity related and Oklo-Munana type deposits are favourable at (a) and (b). (a) the Lower Proterozoic Eburnian belts which are unconformably overlain by sequences of Kibaran and also the unmetamorphosed sequences in Pan-African. The age and paleoenvironment of the unmetamorphosed sequences in Pan-African is comparable to Kibaran. (b) the unmetamorphosed sequences in Eburnian. 2. The Rossing, Shinkolobwe and Dome type deposits are favourable at the Upper Proterozoic Pan-African Belts. (author)

Bioherbicidal activity of a germacranolide sesquiterpene dilactone from Ambrosia artemisiifolia L.

Science.gov (United States)

Molinaro, Francesco; Monterumici, Chiara Mozzetti; Ferrero, Aldo; Tabasso, Silvia; Negre, Michèle

2016-12-01

Ambrosia artemisiifolia L. (common ragweed) is an invasive plant whose allelopathic properties have been suggested by its field behaviour and demonstrated through phytotoxicity bioassays. However, the nature of the molecules responsible for the allelopathic activity of common ragweed has not been explored. The main objective of this study was to identify the phytotoxic molecules produced by A. artemisiifolia. A preliminary investigation has indicated that a methanol extract of A. artemisiifolia completely inhibited the germination of cress and radish. Semi-preparative fractionation of the methanol extract allowed separating of phytotoxic fraction which contained a single compound. The structure of this compound was elucidated by liquid chromatography-mass spectrometry (LC-MS)/MS, high-resolution mass spectral, nuclear magnetic resonance, and Fourier transform infrared spectra as sesquiterpene lactone isabelin (C 15 H 16 O 4 ). The effect of pure isabelin was tested on four different weed species, confirming the inhibitory activity of molecule. The results indicate directions for the future studies about herbicidal specific activity of isabelin, as pure molecule or in the crude extract, as a potential candidate for biological weed control.

Method for converting uranium oxides to uranium metal

Science.gov (United States)

Duerksen, Walter K.

1988-01-01

A process is described for converting scrap and waste uranium oxide to uranium metal. The uranium oxide is sequentially reduced with a suitable reducing agent to a mixture of uranium metal and oxide products. The uranium metal is then converted to uranium hydride and the uranium hydride-containing mixture is then cooled to a temperature less than -100.degree. C. in an inert liquid which renders the uranium hydride ferromagnetic. The uranium hydride is then magnetically separated from the cooled mixture. The separated uranium hydride is readily converted to uranium metal by heating in an inert atmosphere. This process is environmentally acceptable and eliminates the use of hydrogen fluoride as well as the explosive conditions encountered in the previously employed bomb-reduction processes utilized for converting uranium oxides to uranium metal.

Morphological Comparison of U3O8 Ore Concentrates from Canada Key Lake and Namibia Sources

Energy Technology Data Exchange (ETDEWEB)

Schwartz, Daniel S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Tandon, Lav [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Martinez, Patrick Thomas [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

2016-03-11

Uranium ore concentrates from two different sources were examined using scanning electron microscopy (SEM) and energy dispersive spectroscopy (EDS). The ore powders are referred to as Namibia (id. no. 90036, LIMS id. no. 18775) and Canada Key Lake (id. no. 90019, LIMS id. no. 18774). Earlier work identified the ores as the U₃O₈ phase of uranium oxide using x-ray diffraction. Both sets of powders were in the form of dark brown to black powder fines. However, the Canada Key Lake concentrates contained larger chunks of material on the millimeter scale that were easily visible to the unaided eye. The powders were mounted for SEM examination by hand dispersing a small amount onto conductive sticky tape. Two types of applicators were used and compared: a fine-tipped spatula and a foam-tipped applicator. The sticky tape was on a standard SEM “tee” mount, which was tapped to remove loose contamination before being inserted into the SEM.

First records of Cyclorhipidion fukiense (Eggers) (Coleoptera: Curculionidae: Scolytinae: Xyleborini), an ambrosia beetle native to Asia, in North America.

Science.gov (United States)

Hoebeke, E Richard; Rabaglia, Robert J; KnÍŽek, MiloŠ; Weaver, John S

2018-03-13

The Asian ambrosia beetle, Cyclorhipidion fukiense (Eggers) was detected for the first time in North America based on three specimens trapped in 2012 from three localities in South Carolina and two other specimens intercepted at the port of Savannah, Georgia, in 2010. The species is characterized, illustrated with high-resolution images, and compared with two other congeneric, adventive species (C. bodoanum and C. pelliculosum) presently established in eastern North America. Morphometric measurements are provided and a provisional key is presented to the species of Cyclorhipidion occurring in North America.

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

International Nuclear Information System (INIS)

Dave, N.K.; Lim, T.P.; Cloutier, N.R.

1985-01-01

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)

Uranium

International Nuclear Information System (INIS)

Cuney, M.; Pagel, M.; Leroy, J.

1992-01-01

First, this book presents the physico-chemical properties of Uranium and the consequences which can be deduced from the study of numerous geological process. The authors describe natural distribution of Uranium at different scales and on different supports, and main Uranium minerals. A great place in the book is assigned to description and classification of uranium deposits. The book gives also notions on prospection and exploitation of uranium deposits. Historical aspects of Uranium economical development (Uranium resources, production, supply and demand, operating costs) are given in the last chapter. 7 refs., 17 figs

Uranium resources in fine-grained carbonaceous rocks of the Great Divide Basin, south-central Wyoming. National Uranium Resource Evaluation

International Nuclear Information System (INIS)

Burger, J.A.; Roe, L.M. II; Hacke, C.M.; Mosher, M.M.

1982-11-01

The uranium resources of the fine-grained carbonaceous rocks of the Great Divide Basin in southern Wyoming were assessed. The assessment was based primarily on data from some 600 boreholes. The data included information from geophysical logs, lithologic logs and cores, and drill cuttings. The cores and cuttings were analyzed for chemical U 3 O 8 , radiometric U, Th and trace elements. Selected samples were examined by thin section, sieve analysis, x-ray, SEM, ion probe, and alpha track methods. The uranium is associated with fine-grained carbonaceous shales, siltstones, mudstones, and coals in radioactive zones 5 to 50 ft thick that are continuous over broad areas. These rocks have a limited stratigraphic range between the Red Desert tongue of the Wasatch Formation and the lower part of the Tipton tongue of the Green River Formation. Most of this uranium is syngenetic in origin, in part from the chelation of the uranium by organic material in lake-side swamps and in part as uranium in very fine detrital heavy minerals. The uraniferous fine-grained carbonaceous rocks that exceed a cutoff grade of 100 ppM eU 3 O 8 extend over an area of 542 mi 2 and locally to a depth of approximately 2000 ft. The uraniferous area is roughly ellipical and embraces the zone of change between the piedmont and alluvial-fan facies and the lacustrine facies of the intertonguing Battle Spring, Wasatch, and Green River Formations. About 1.05 x 10 6 tons U 3 O 8 , based on gross-gamma logs not corrected for thorium, are assigned to the area in the first 500 ft; an estimated 3.49 x 10 6 tons are assigned to a depth of 1000 ft. These units also contain a substantial thorium resource that is also associated with fine-grained rocks. The thorium-to-uranium ratio generally ranges between 1 and 4. A thorium resource of 3.43 x 10 6 tons to a depth of 500 ft is estimated for the assessment area. 5 figures, 3 tables

Analysis of expert opinion on uranium mill tailings remedial action project (UMTRAP) alternatives: a decision-support-system pilot study

International Nuclear Information System (INIS)

Thode, E.F.

1983-01-01

The Uranium Mill Tailings Remedial Action Project requires a specific remedial action individually chosen for each site. A panel of professionals was asked to rate objectives for remedial action and to rank alternatives for meeting the objectives. Responses were statistically analyzed. The panel's preference was earth cover in place at the Salt Lake City, Utah, and Shiprock, New Mexico, sites. Asphalt cover was next at Salt Lake City. This decision support system is appropriate for use with other inactive and active tailings sites

Uranium

International Nuclear Information System (INIS)

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

2010-01-01

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

Results of the independent radiological verification survey at 4400 Piehl Road, Ottawa Lake, Michigan (BTO002)

Energy Technology Data Exchange (ETDEWEB)

Murray, M.E.; Brown, K.S.

1996-04-01

At the request of the US Department of Energy (DOE), a team from Oak Ridge National Laboratory (ORNL) conducted an independent radiological verification survey at Ottawa Lake, Michigan. The survey was performed in November and December of 1994. The purpose of the survey was to verify that the site was remediated to levels below the DOE guidelines for FUSRAP sites. Results of the independent radiological verification survey at Ottawa Lake, Michigan confirm that the residual uranium contamination at the site is below DOE FUSRAP guidelines for unrestricted use.

Low grade uranium deposits of India - a bane or boon

International Nuclear Information System (INIS)

Chaki, Anjan

2010-01-01

Uranium resources of the world is estimated to be 5.5 million tonnes and the proven resources in India forms 3% of the world resources. The biggest uranium deposit is the Olympic dam deposit in Australia, which contains nearly one million tonnes of 0.04% U 3 O 8 , while the highest grade of nearly 20% is established in the McArthur river deposit, Canada. Another very high grade deposit, the Cigar lake deposit, is established in Canada with an average grade of nearly 18%. Most of the uranium deposits established in India so far falls under the category of low grade. These low grade uranium deposits are distributed mainly in Singhbhum Shear Zone, eastern India; in parts of Chhattisgarh; Southern parts of Meghalaya; Cuddapah Basin, Andhra Pradesh; in parts of Karnataka and Aravalli- and Delhi Supergroups, Rajasthan and Haryana. These deposits are mainly hydrothermal vein type, stratabound type and unconformity related. The Singhbhum Shear Zone, Jharkhand hosts a seventeen low grade uranium deposits, aggregating about 30% of Indian uranium resources. The uranium mineralisation hosted by Vempalle dolostone extends over 160 km belt along southwestern margin of Cuddapah Basin in Andhra Pradesh and accounts 23% of the Indian resources. Though the dolostone hosted Tummalapalle uranium deposit was established in the early nineties, because of techno-economic constraints, the deposit remained dormant. As a consequence of the development of an innovative pressure alkali beneficiation process, the deposit became economically viable and a mine and mill are being constructed here. Recent exploration inputs are leading to prove a number of low grade uranium deposits in the extension areas of Tummalapalle. Nearly 10 blocks have been identified within a 30 km belt which are being actively explored and a large uranium deposit has already been proved in this province. The deposit at Tummalapalle and adjoining areas is likely to become the second biggest deposit in the world. The

The geology of the Collins Bay uranium deposit, Saskatchewan

International Nuclear Information System (INIS)

Jones, B.E.

1980-01-01

The Collins Bay deposit lies within the Churchill Province on the western edge of the Wollaston lithostructural domain where it underlies the eastern edge of the Helikian Athabasca Formation. It is 6 miles north-northeast of the Rabbit Lake mine. Two principal zones of uranium mineralization are described. The A zone, a partly eroded, high-grade pod of metal oxide and arsenides sheathed by clay-like minerals, which trends north-northeast and lies under 25 to 40 feet of water; and the B zone, which lies 6 000 ft south of the A, subcrops under till cover and is a partly eroded zone composed of metal oxide and arsenides which occur within variably altered Athabasca Formation. The deposit is typical of the unconformity-type uranium-nickel deposits of the Athabasca Basin. Observed features fit well with the diagenetic-hydrothermal model for such deposts. (auth)

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

International Nuclear Information System (INIS)

Arsenault, J.E.

2008-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Arsenault, J.E

2008-03-15

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

Uranium isotopes in waters and bottom sediments of rivers and lakes in Poland

International Nuclear Information System (INIS)

Pietrzak-Flis, Z.; Kaminska, I.; Chrzanowski, E.

2004-01-01

Activity concentrations of 238 U, 234 U and 235 U were determined in waters and bottom sediments in two main rivers in Poland (the Vistula and Odra rivers) with their tributaries, in four coastal rivers and six lakes. Concentration of 238 U and 233 U were compared with the concentrations of 226 Ra determined in another study. As compared with concentrations in coastal rivers and in lakes, enhanced concentrations of the radionuclides were observed in water and bottom sediments in the upper and middle courses of Vistula river, whereas in the Odra river the enhanced concentrations were present only in the bottom sediments. The enhanced concentrations in the Vistula river result from the discharge of coal mine waters from the Upper Silesian Coal Basin, and they indicate that the discharge was continued. The enhanced concentration in Odra river observed only in bottom sediments indicate that the discharge occurred in the past. The 234 U/ 238 U ratio for the bottom sediments was close to unity, indicating that these isotopes were close to equilibrium, whereas for water the average ratio was form 1.2 for lakes to 1.5 for the Vistula river, demonstrating the lack of equilibrium. (author)

Uranium concentrations in lake and stream waters and sediments from selected sites in the Susitna River Basin, Alaska

International Nuclear Information System (INIS)

Hill, D.E.

1977-03-01

During the summer of 1976, 141 water and 211 sediment samples were taken from 147 locations in the Susitna River basin in Alaska by the Geophysical Institute of the University of Alaska for the LASL. These samples were taken to provide preliminary information on the uranium concentrations in waters and sediments from the Susitna River basin and to test the analytical methods proposed for the NURE Hydrogeochemical and Stream Sediment Reconnaissance for uranium in Alaska. The uranium determinations resulting from the fluorometric analysis of the water samples and the delayed-neutron counting of the sediment samples are presented. The low levels of uranium in the water samples, many of which were below the detectable limit of the LASL fluorometric technique, indicate that a more sensitive analytical method is needed for the analysis of Alaskan water samples from this area. An overlay showing numbered sample locations and overlays graphically portraying the concentrations of uranium in the water and sediment samples, all at 1:250,000 scale for use with existing USGS topographic sheets, are also provided as plates

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

Energy Technology Data Exchange (ETDEWEB)

Thunaes, A [Eldorado Mining and Refining Ltd., Ottawa (Canada)

1967-06-15

The Canadian production of uranium increased in a spectacular manner during the period 1955-1959 from 1000 to 15 500 tons U{sub 3}O{sub 8} per year. Since 1959 the production has declined to the 1966 level of 3900 tons U{sub 3}O{sub 8} per year; stretch-out of contracts and government stockpiling programmes has made the decline gradual, and is maintaining the current rate of production until 1970. Nineteen mills were in operation during the period of peak production but only three are operating today. Ten mills were shut down and dismantled because of exhaustion of ore bodies or because the operation was uneconomical; six mills are maintained in stand-by condition. The total daily capacity of mills in operation or standing by is about 28 000 tons ore, but some of these mills would not be reopened unless an appreciable increase in uranium price occurs. The tide of uranium demand is about ready to turn and prospecting for uranium is very active this year, particularly in the Elliot Lake and Beaverlodge areas. The estimates for uranium demand in 1975-1980 are such that new ore will have to be found and developed, and new treatment plants must be built. The new ore that is found will likely be of lower grade or more expensive to mine than most of the current proven reserves in Canada and the most efficient methods of treatment will be needed to avoid excessive increases in production costs. This seems an opportune time to review Canadian milling of uranium ore, the improvements that have been made and development work towards further improvements.

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

Energy Technology Data Exchange (ETDEWEB)

Rapp, J.S.; Short, W.O.

1981-06-01

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% U/sub 3/O/sub 8/. 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.

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

International Nuclear Information System (INIS)

Rapp, J.S.; Short, W.O.

1981-06-01

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% U 3 O 8 . 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

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

International Nuclear Information System (INIS)

1995-06-01

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

Uranium concentrations and 234U/238U activity ratios in fault-associated groundwater as possible earthquake precursors

International Nuclear Information System (INIS)

Finkel, R.C.

1981-01-01

In order to assess the utility of uranium isotopes as fluid phase earthquake precursors, uranium concentrations and 234 U/ 238 U activity ratios have been monitored on a monthly or bimonthly basis in water from 24 wells and springs associated with Southern California fault zones. Uranium concentrations vary from 0.002 ppb at Indian Canyon Springs on the San Jacinto fault to 8.3 ppb at Lake Hughes well on the San Andreas fault in the Palmdale area. 234 U/ 238 U activity ratios vary from 0.88 at Agua Caliente Springs on the Elsinore fault to 5.4 at Niland Slab well on the San Andreas fault in the Imperial Valley. There was one large earthquake in the study area during 1979, the 15 October 1979 M = 6.6 Imperial Valley earthquake. Correlated with this event, uranium concentrations varied by a factor of more than 60 and activity ratios by a factor of 3 at the Niland Slab site, about 70 km from the epicenter. At the other sites monitored, uranium concentrations varied in time, but with no apparent pattern, while uranium activity ratios remained essentially constant throughout the monitoring period

The determination of radium-226 in uranium ores and mill products by alpha energy spectrometry

International Nuclear Information System (INIS)

Zimmerman, J.B.; Armstrong, V.C.

1975-12-01

A reliable routine procedure for determining 226 Ra by alpha energy spectrometry is described. Radium is isolated as sulphate from the sample matrix by co-precipitation with a small mass of barium and analysed using a ruggedized silicon surface barrier detector. The method is capable of providing high accuracy over a large 226 Ra concentration range and is applicable to materials such as uranium ores, uranium mill products and effluent streams. Samples resulting from nitric acid leach experiments with Elliot Lake ores were examined using the procedure. The distribution of 223 Ra, 224 Ra and 226 Ra between the leach products, (residue and leach liquor), is discussed. (author)

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

International Nuclear Information System (INIS)

Gallagher, G.L.

1976-10-01

The area is approximately 1,800 square miles and extends from Cripple Creek northward to Fairplay and Bailey. The Precambrian rocks include the metamorphic sequences of the Idaho Springs Formation and the Boulder Creek Granodiorite, Silver Plume Granite, Pikes Peak Granite, and Redskin Granite. The known uranium deposits in the area include six vein deposits, three pegmatite occurrences, and one zone of probable secondary enrichment; they have not yielded any significant production. The vein deposits are probably the result of downward percolation of ground water. The zone of secondary uranium enrichment may have formed above a volcanic pipe, vein, or tuffaceous lake bed. Favorability in the area is considered good for both vein and large, disseminated, low-grade uranium deposits. On the bases of known uranium occurrences, favorable structures and host rocks, and a water-sampling program, recommendations are given for exploration. The occurrences in the area have substantial similarities with the Rossing deposit in South-West Africa and the Wheeler Basin uranium occurrence in Grand County, Colorado. 6 figures, 9 tables

Uranium conversion

International Nuclear Information System (INIS)

Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina

2006-03-01

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 UF 6 and UF 4 are present require equipment that is made of corrosion resistant material

Transfer of the uranium decay products, polonium-210 and lead-210, through the lichen-caribou-wolf food chain in northern Canada (manuscript report)

International Nuclear Information System (INIS)

Thomas, P.A.

1991-05-01

The main purpose of this study is to investigate the accumulation and transfer of polonium-210 and lead-210 in the arctic food chain, lichen-caribou-wolf, in the Northwest Territories. Polonium-210 arises from lead-210 decay and is a widespread alpha-emitting radionuclide. It seeks soft tissue and has the potential to accumulate in the food chain. Caribou, wolves and other wildlife may become exposed to enhanced levels of these two uranium-series radionuclides if the proposed uranium mine near Baker Lake, Northwest Territories, proceeds. Baker Lake lies at the crossroads of the ranges of the Beverly, the Kaminuriak and the Wager Bay caribou herds. Therefore, it is important to establish baseline concentrations and natural food chain transfer of uranium series radionuclides, in this study. This information can be used for baseline data before any further mining development takes place. This study will also provide data regarding the statistical uncertainty attached to transfer coefficients. This can help ensure reliable and appropriate future monitoring of environmental change. With the participation of the hunters of Baker Lake, caribou and wolf samples were collected and analyzed for polonium. Results indicate that polonium-210 activity in caribou tissues were somewhat higher than previous data reported from Alaska. Transfer coefficients for polonium-210 from caribou to wolf were near unity for many tissues. However, polonium-210 does not appear to cross the placenta in caribou. Further study includes lichen collections and collection of further caribou samples from the beverly herd in order to determine transfer from lichens to caribou in both the Baker Lake and Snowdrift areas in the Northwest Territories. (author). 26 refs., 3 tabs

Transfer of the uranium decay products, polonium-210 and lead-210, through the lichen-caribou-wolf food chain in northern Canada (manuscript report)

Energy Technology Data Exchange (ETDEWEB)

Thomas, P A [Sasatchewan Univ., Saskatoon (Canada). Biology Dept.

1991-05-01

The main purpose of this study is to investigate the accumulation and transfer of polonium-210 and lead-210 in the arctic food chain, lichen-caribou-wolf, in the Northwest Territories. Polonium-210 arises from lead-210 decay and is a widespread alpha-emitting radionuclide. It seeks soft tissue and has the potential to accumulate in the food chain. Caribou, wolves and other wildlife may become exposed to enhanced levels of these two uranium-series radionuclides if the proposed uranium mine near Baker Lake, Northwest Territories, proceeds. Baker Lake lies at the crossroads of the ranges of the Beverly, the Kaminuriak and the Wager Bay caribou herds. Therefore, it is important to establish baseline concentrations and natural food chain transfer of uranium series radionuclides, in this study. This information can be used for baseline data before any further mining development takes place. This study will also provide data regarding the statistical uncertainty attached to transfer coefficients. This can help ensure reliable and appropriate future monitoring of environmental change. With the participation of the hunters of Baker Lake, caribou and wolf samples were collected and analyzed for polonium. Results indicate that polonium-210 activity in caribou tissues were somewhat higher than previous data reported from Alaska. Transfer coefficients for polonium-210 from caribou to wolf were near unity for many tissues. However, polonium-210 does not appear to cross the placenta in caribou. Further study includes lichen collections and collection of further caribou samples from the beverly herd in order to determine transfer from lichens to caribou in both the Baker Lake and Snowdrift areas in the Northwest Territories. (author). 26 refs., 3 tabs.

Behaviour of uranium series radionuclides in surface water (Crouzille, Limousin). Geochemical implications

International Nuclear Information System (INIS)

Moulin, J.

2008-06-01

Understanding natural radionuclides behaviour in surface water is a required step to achieve uranium mine rehabilitation and preserve water quality. The first objective of this thesis is to determine which are the radionuclides sources in a drinking water reservoir. The second objective is to improve the knowledge about the behaviour of uranium series radionuclides, especially actinium. The investigated site is a brook (Sagnes, Limousin, France) which floods a peat bog contaminated by a former uranium mine and which empties into the Crouzille lake. It allows studying radionuclides transport in surface water and radionuclides retention through organic substance or water reservoir. Radionuclides distribution in particulate, colloidal and dissolved phases is determined thanks to ultra-filtrations. Gamma spectrometry allows measuring almost all natural radionuclides with only two counting stages. However, low activities of 235 U series radionuclides impose the use of very low background well-type Ge detectors, such as those of the Underground Laboratory of Modane (France). Firstly, this study shows that no or few radionuclides are released by the Sagnes peat bog, although its radioactivity is important. Secondly, it provides details on the behaviour of uranium series radionuclides in surface water. More specifically, it provides the first indications of actinium solubility in surface water. Actinium's behaviour is very close to uranium's even if it is a little less soluble. (author)

Machining of uranium and uranium alloys

International Nuclear Information System (INIS)

Morris, T.O.

1981-01-01

Uranium and uranium alloys can be readily machined by conventional methods in the standard machine shop when proper safety and operating techniques are used. Material properties that affect machining processes and recommended machining parameters are discussed. Safety procedures and precautions necessary in machining uranium and uranium alloys are also covered. 30 figures

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)

Harms, V.L.

1982-07-01

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

Identification of poorly crystalline scorodite in uranium mill tailings

International Nuclear Information System (INIS)

Frey, R.; Rowson, J.; Hughes, K.; Rinas, C.; Warner, J.

2010-01-01

The McClean Lake mill, located in northern Saskatchewan, processes a variety of uranium ore bodies to produce yellowcake. A by-product of this process is an acidic waste solution enriched in arsenic, referred to as raffinate. The raffinate waste stream is treated in the tailings preparation circuit, where arsenic is precipitated as a poorly crystalline scorodite phase. Raffinate neutralization studies have successfully identified poorly crystalline scorodite using XRD, SEM, EM, XANES and EXAFS methods, but to date, scorodite has not been successfully identified within the whole tailing solids. During the summer of 2008, a drilling program sampled the in situ tailings within the McClean Lake tailings management facility. Samples from this drilling campaign were sent to the Canadian Light Source Inc. for EXAFS analysis. The sample spectra positively identify a poorly crystalline scorodite phase within the McClean tailings management facility. (author)

Uranium Mill Tailings Remedial Action Program. Annual status report

International Nuclear Information System (INIS)

1984-12-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project FY 1984 major accomplishments are summarized. Twenty-five percent of the processing site remedial actions at Canonsburg, PA, were completed. Remedial action on 118 vicinity properties at four designated locations were initiated and survey and inclusion activities on a total of 420 vicinity properties were completed. The Environmental Impact Statement (EIS) for Salt Lake City, UT, and the Environmental Assessment (EA) for Shiprock, NM were published, and the preliminary draft EIS for Durango, CO, was prepared. Remedial Action Plans (RAPs) for Salt Lake City, UT, and Shiprock, NM were completed, and draft RAPs for Gunnison, CO, and Riverton, WY were prepared. Cooperative agreements with Oregon, Wyoming, and South Dakota were executed, and the Utah cooperative agreement was modified to assign the construction management responsibility to the state. An Interagency Agreement with TVA for disposal of the Edgemont vicinity property material was executed

Uranium recovery from slags of metallic uranium

International Nuclear Information System (INIS)

Fornarolo, F.; Frajndlich, E.U.C.; Durazzo, M.

2006-01-01

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 (U 3 Si 2 ) from Hexafluoride of Uranium (UF 6 ) with enrichment 20% in weight of 235 U. 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 U 3 O 8 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 U 3 O 8 . 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)

Uranium, depleted uranium, biological effects; Uranium, uranium appauvri, effets biologiques

Energy Technology Data Exchange (ETDEWEB)

NONE

2001-07-01

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)

Nocturnal drainage wind characteristics in two converging air sheds

International Nuclear Information System (INIS)

Gedayloo, T.; Clements, W.E.; Barr, S.; Archuleta, J.A.

1980-01-01

During the short experimental period in the Grants Basin of Northeastern New Mexico a survey was conducted on the complex meteorology of this area. Emphasis was placed on the nocturnal drainage flow because of the potential hazards to the populated areas of Milan and Grants from the effluents of the uranium mining and milling operation in this area. This investigation has shown that the nocturnal drainage flow patterns agree with the winds predicted on the basis of the complex terrain of the area. Because of the surface cooling at night (over 25 0 C during summer and about 20 0 C during winter), air from elevated surrounding areas flows to the low lying regions consequently setting up a nocturnal drainage flow. This regime exists over 60% of the time during summer months and over 65% of the time during winter months with a depth generally less than 200 m. In the San Mateo air shed the drainage flow is east northeast, and in the Ambrosia Lake air shed it is from northwest. The confluence of these two air flows contributes mainly to the drainage flow through the channel formed by La Ja Mesa and Mesa Montanosa. The analysis of data collected by the recording Flats Station confirms the prediction that although the area south of the channel region broadens considerably causing a reduction in flow speed, contributions from the southside of La Jara Mesa and Mesa Montanosa partly compensate for this reduction. The position of this recording station is 15 to 20 km from the populated towns of Milan and Grants. A drainage flow speed of approximately 2.2 m s -1 and the duration of over 11 hours as recorded by this station indicates that air from the San Mateo and Ambrosia Lake regions may be transported southwards to these population centers during a nocturnal period. In order to test this prediction, a series of multi-atmospheric tracer experiments were conducted in the Grants Basin

Radionuclide concentrations in fish collected from Jemez, Nambe, and San Ildefonso Tribal Lakes

International Nuclear Information System (INIS)

Fresquez, P.R.; Armstrong, D.R.; Salazar, J.G.

1995-02-01

Radionuclide concentrations ( 90 Sr, 137 Cs, 238 Pu, 239 Pu,and total uranium) were determined in fish collected from Jemez, Nambe, and San Ildefonso tribal lakes. With the exception of 137 Cs, all other radionuclides were not significantly different in (stocked) rainbow trout collected from Jemez and Nambe as compared with game fish collected from Abiquiu, Heron, and El Vado Reservoirs. Although 137 Cs levels in trout from Jemez (3.2 x 10 -2 pCi per dry gram) and Nambe (7.5 x 10 -2 pCi per dry gram) were significantly higher than 137 Cs concentrations in fish from Abiquiu, Heron, and El Vado, they were still well below the regional statistical (worldwide fallout) reference level (i.e., -2 pCi per dry gram). Game and nongame fish collected from San Ildefonso contained higher and significantly higher concentrations of uranium, respectively, as compared with fish collected from Abiquiu, Heron, and El Vado. The higher uranium concentrations in fish from San Ildefonso as compared with fish from Abiquiu, Heron, and El Vado were attributed to the higher natural soil uranium contents in the area as compared with the geology of the area upstream of San Ildefonso. The effective (radiation) dose equivalent (EDE) from consuming 46 lb of game fish from Jemez, Nambe, and San Ildefonso lakes, after natural background has been subtracted, was 0.013 (±0.002), 0.019 (±0.012), and 0.017 (±0.028) mrem/yr, respectively. Similarly, the EDE from consuming nongame fish from San Ildefonso was 0.0092 (±0.0084) mrem/yr. The highest calculated dose, based on the mean + 2 standard deviation (95% confidence level), was 0.073 mrem/yr; this was <0.08% of the International Commission on Radiological Protection permissible dose limit for protecting members of the public

The genesis of surficial uranium deposits

International Nuclear Information System (INIS)

Boyle, D.R.

1984-01-01

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)

Uranium series radionuclides, polonium-210 and lead-210, in the lichen-caribou-wolf food chain of the Northwest Territories

International Nuclear Information System (INIS)

Thomas, P.A.; Sheard, J.W.; Swanson, S.

1994-01-01

This report examines baseline concentrations and transfer of the uranium decay products polonium-210 and lead-210 in the lichen-caribou-wolf food chain at two locations in the Northwest Territories, Baker Lake and Snowdrift. At each location, concentrations of the two radionuclides were determined in the lichen species Cetraria nivalis and Cladina mitis, and several tissues from caribou and wolves. Baseline concentrations and transfer coefficients within the food chain were compared between the two locations. Lichen samples were also collected from Kasba Lake, a third hunting ground used by northern Saskatchewan hunters. The lichen species chosen were common forage for caribou. Both the predominant lichen species at each location and rumen contents were used to estimate the winter diet of caribou in the calculation of transfer coefficients. The results are relevant to environmental monitoring in areas of potential future uranium mining development and the transfer coefficients determined in the study may be used to estimate radionuclide concentrations and radiation doses in future environmental assessments

Uranium tailings in the public eye

International Nuclear Information System (INIS)

Lyon, B.

1976-01-01

The ORNL field team visits to Grand Junction, Colorado, and to other sources of uranium mill tailings, are described. The radioactive hazards of these tailings, which are principally due to Th, Ra, Rn, and radon daughters, are discussed briefly. Government actions which were taken as a result of public concern are listed. The ORNL Health Physics Division mobile laboratory van and its use in assessing the tailings piles at Salt Lake City and elsewhere are described. The highest γ-ray background found was 155 mRem/y, with levels being as high as 1750 mRem/y near points of public access to piles. Some possible solutions to the problem are discussed

Hydrology of Quirke and Panel uranium tailings basins

International Nuclear Information System (INIS)

King, R.M.; MacPhie, L.

1991-11-01

The research project described by this report provides the AECB with an independent assessment of the 'saturated tailings concept' for the decommissioning of tailing areas at the Rio Algom Quirke and Panel uranium mines near Elliot Lake in Northern Ontario. Hydrologic and hydraulic modelling for each facility showed the interrelation between the design of the water-level control facilities and the water levels in each cell for design flood and extreme low-flow conditions, taking into account all water-balance components. The estimate of seepage rates through the tailings mass is identified as a critical issue

The Cigar Lake analog study: An international R ampersand D project

International Nuclear Information System (INIS)

Cramer, J.J.; Sargent, F.P.

1994-01-01

This paper provides background information and summarizes the results of AECL's analog study on the Cigar Lake uranium deposit. This R ampersand D project includes national and international cooperation with many organizations directly or indirectly involved in nuclear waste management research. The emphasis is on the analog aspects of this deposit and the implications of modelling activities related to the environmental and safety assessment of the Canadian disposal concept for nuclear fuel waste

Evaluation of Van Lake (Turkey) about radiological and hydrogeological risk

International Nuclear Information System (INIS)

Akyil, S.; Aytas, S.; Yusan, S.; Aslani, M. A. A.; Aycan, H. A.; Eral, M.; Tuerkoezue, D. A.; Isik, M. A.; Oelgen, M. K.

2009-01-01

Basins which are grow in the continent and not discharge to open sea are named as a close basin. Lead, uranium and thorium are high levels in respect to open basins. Lake of Van is a close basin. In the lake basins, rivers which are discharge basin are the most important source of the heavy metal concentration. In this study, surface water, coast and deep sediments of Van Lake and Inci Kefal (fish) were analyzed as a radiological and evaluated in terms of hydrogeological. Data was obtained for natural radioactivity concentration of this lake and evaluated using geostatistical methods in a geographical information system environment and fitted for isoradioactivity contour maps. The concentration and distribution of natural radionuclides in Van Lake were investigated with the aim of evaluating the environmental radioactivity. Sixty three coastal and deep sediments, 228 lake surface waters and 12 fish samples were taken in Van Lake over the time period 2005-2008 and the distribution pattern of the measured radionuclides was presented. The mean concentrations of gross alpha and beta, eU, eTh and K-40 activities in sediments were 207±96, 1046±60, 207±96, 70±29 and 399±231 Bq/kg, respectively. On the other hand, water samples from Van Lake had mean concentrations of 0.74±0.46 Bq/L for gross alpha activity concentration, 0.02±0.01 Bq/L for gross beta activity concentration, 0.06±0.04 Bq/L for gross radium isotopes, respectively. The mean gross alpha and beta, eU, eTh and K-40 activities in fish samples were 47±18, 470±12, 0.57±0.22, 0.022±0.006, 319±11 Bq/kg, respectively. An average annual effective dose equivalent (mSv/y) was calculated.

Possible uranium sources of Streltsovsky uranium ore field

International Nuclear Information System (INIS)

Zhang Lisheng

2005-01-01

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

Process for continuous production of metallic uranium and uranium alloys

Science.gov (United States)

Hayden, Jr., Howard W.; Horton, James A.; Elliott, Guy R. B.

1995-01-01

A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO.sub.3), or any other substantially stable uranium oxide, to form the uranium dioxide (UO.sub.2). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl.sub.4), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation.

Process for continuous production of metallic uranium and uranium alloys

Science.gov (United States)

Hayden, H.W. Jr.; Horton, J.A.; Elliott, G.R.B.

1995-06-06

A method is described for forming metallic uranium, or a uranium alloy, from uranium oxide in a manner which substantially eliminates the formation of uranium-containing wastes. A source of uranium dioxide is first provided, for example, by reducing uranium trioxide (UO{sub 3}), or any other substantially stable uranium oxide, to form the uranium dioxide (UO{sub 2}). This uranium dioxide is then chlorinated to form uranium tetrachloride (UCl{sub 4}), and the uranium tetrachloride is then reduced to metallic uranium by reacting the uranium chloride with a metal which will form the chloride of the metal. This last step may be carried out in the presence of another metal capable of forming one or more alloys with metallic uranium to thereby lower the melting point of the reduced uranium product. The metal chloride formed during the uranium tetrachloride reduction step may then be reduced in an electrolysis cell to recover and recycle the metal back to the uranium tetrachloride reduction operation and the chlorine gas back to the uranium dioxide chlorination operation. 4 figs.

Relationship between natural radioactivity and rock type in the Van lake basin - Turkey

International Nuclear Information System (INIS)

Tolluoglu, A. U.; Eral, M.; Aytas, S.

2004-01-01

The Van Lake basin located at eastern part of Turkey. The Van lake basin essentially comprises two province, these are namely Van and Bitlis. The former geochemistry research indicated that the uranium concentrations of Van lake water and deep sediments are 78-116 ppb and 0.1-0.5 ppm respectively. Uranium was transported to Van Lake by rivers and streams, flow through to outcrops of Paleozoic Bitlis Massive, and young Pleistocene alkaline/calkalkaline volcanic rocks. This study focused on the revealing natural radioactivity and secondary dispersion of radioactivity related to rock types surface environments in the Van Lake Basin. The Van Lake Basin essentially subdivided into three different parts; the Eastern parts characterized by Mesozoic basic and ultra basic rocks, southern parts dominated by metamorphic rocks of Bitlis Massive, Western and Northwestern parts covered by volcanic rocks of Pleistocene. Volcanic rocks can be subdivided into two different types. The first type is mafic rocks mainly composed of basalts. The second type is felsic rocks represented by rhyolites, dacites and pumice tuff. Surface gamma measurements (cps) and dose rate measurements (μR/h) show different values according to rock type. Surface gamma measurement and surface dose rate values in the basaltic rocks are slightly higher than the average values (130 cps, 11 μR/h). In the felsic volcanic rocks such as rhyolites and dacites surface gamma measurement values and surface dose rate values, occasionally exceed the background. Highest values were obtained in the pumice tuffs. Rhyolitic eruptions related to Quaternary volcanic activity formed thick pumice (natural glassy froth related to felsic volcanic rocks and exhibit spongy texture) sequences Northern and Western part of Van Lake basin. The dose rate of pumice rocks was measured mean 15 μR/h. The highest value for surface gamma measurements was recorded as 200 cps. The pumice has very big water capacity, due to porous texture of

Bacterial diversity and composition of an alkaline uranium mine tailings-water interface.

Science.gov (United States)

Khan, Nurul H; Bondici, Viorica F; Medihala, Prabhakara G; Lawrence, John R; Wolfaardt, Gideon M; Warner, Jeff; Korber, Darren R

2013-10-01

The microbial diversity and biogeochemical potential associated with a northern Saskatchewan uranium mine water-tailings interface was examined using culture-dependent and -independent techniques. Morphologically-distinct colonies from uranium mine water-tailings and a reference lake (MC) obtained using selective and non-selective media were selected for 16S rRNA gene sequencing and identification, revealing that culturable organisms from the uranium tailings interface were dominated by Firmicutes and Betaproteobacteria; whereas, MC organisms mainly consisted of Bacteroidetes and Gammaproteobacteria. Ion Torrent (IT) 16S rRNA metagenomic analysis carried out on extracted DNA from tailings and MC interfaces demonstrated the dominance of Firmicutes in both of the systems. Overall, the tailings-water interface environment harbored a distinct bacterial community relative to the MC, reflective of the ambient conditions (i.e., total dissolved solids, pH, salinity, conductivity, heavy metals) dominating the uranium tailings system. Significant correlations among the physicochemical data and the major bacterial groups present in the tailings and MC were also observed. Presence of sulfate reducing bacteria demonstrated by culture-dependent analyses and the dominance of Desulfosporosinus spp. indicated by Ion Torrent analyses within the tailings-water interface suggests the existence of anaerobic microenvironments along with the potential for reductive metabolic processes.

Profundal sideritic mudstone from an Eocene lake in Alaska

International Nuclear Information System (INIS)

Dickinson, K.A.

1987-01-01

Sideritic lacustrine mudstone was found in drill core from a uranium deposit in the Death Valley area in the eastern part of the Seward Peninsula, Alaska. The precursor sediments for this rock were deposited in an unusual iron-meromictic Eocene lake, herein named Lake Tubutulik, which occupied part of the Boulder Creek basin, a graben that is probably a southern extension of the larger Death Valley basin. The Boulder Creek basin is bounded on the west by granite of the Upper Cretaceous Darby pluton and on the east by Precambrian to Paleozoic metasedimentary rocks. The lake basin was formed by basaltic flows that dammed the valley of the ancestral Tubutulik River in early Eocene time. The lake sediments included a nearshore facies of fine-grained organic mud and an offshore facies of laminated sideritic mud. The offshore (profundal) laminated mudstone consists of alternating layers of authigenic siderite and detrital grains, mostly quartz and clay minerals. Both lacustrine facies contain turbidites. The lacustrine rocks graded laterally into an onshore facies of colluvial and fluvial sandstone, paludal mudstone, and coal. The ancient lake occupied a small, deep basin in a tectonically active area of high relief. Meromixis was apparently stabilized by reduced iron and bicarbonate dissolved in the monimolimnion. The intensity of meromixis decreased as the lake became shallower from sediment filling. The source of the dissolved iron in the monoimolimnion was probably the Eocene basalt. Carbon isotope analysis of the siderite suggests that the dissolved bicarbonate in the profundal facies was largely inorganic. Sideritic carbon in one sample from the onshore paludal facies has an isotopic signature (δ 13 C = +16.9) consistent with residual carbonate formed during methanogenic fermentation

Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 2: Small mammal food chains and bioavailability

Energy Technology Data Exchange (ETDEWEB)

Thomas, P.A.

2000-06-01

Food chain transfer through the soil-vegetation-small mammal food chain was measured by concentration ratios (CRs) for uranium, {sup 226}Ra, {sup 210}Pb, and {sup 210}Po at three sites near the Key Lake uranium mill in northern Saskatchewan. Plant/soil CRs, animal carcass/GI tract CRs, and animal/soil CRs were depressed at sites impacted by mill and tailings dusts relative to a nearby control site. Thus, radionuclides associated with large particulates in tailings and/or ore dusts may be less bioavailable to terrestrial plants and animals than natural sources of radioactive dust. These results show that reliance on default food chain transfer parameters, obtained from uncontaminated terrestrial ecosystems, may overpredict impacts at uranium mine and mill sites. Given the omnivorous diet of small mammals and birds, animal/soil CRs are recommended as the most cost-effective and robust means of predicting animal concentrations from environmental monitoring data at uranium mill facilities.

Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 2: Small mammal food chains and bioavailability

International Nuclear Information System (INIS)

Thomas, P.A.

2000-01-01

Food chain transfer through the soil-vegetation-small mammal food chain was measured by concentration ratios (CRs) for uranium, 226 Ra, 210 Pb, and 210 Po at three sites near the Key Lake uranium mill in northern Saskatchewan. Plant/soil CRs, animal carcass/GI tract CRs, and animal/soil CRs were depressed at sites impacted by mill and tailings dusts relative to a nearby control site. Thus, radionuclides associated with large particulates in tailings and/or ore dusts may be less bioavailable to terrestrial plants and animals than natural sources of radioactive dust. These results show that reliance on default food chain transfer parameters, obtained from uncontaminated terrestrial ecosystems, may overpredict impacts at uranium mine and mill sites. Given the omnivorous diet of small mammals and birds, animal/soil CRs are recommended as the most cost-effective and robust means of predicting animal concentrations from environmental monitoring data at uranium mill facilities

Recovery of uranium from crude uranium tetrafluoride

Energy Technology Data Exchange (ETDEWEB)

Ghosh, S K; Bellary, M P; Keni, V S [Chemical Engineering Division, Bhabha Atomic Research Centre, Mumbai (India)

1994-06-01

An innovative process has been developed for recovery of uranium from crude uranium tetrafluoride cake. The process is based on direct dissolution of uranium tetrafluoride in nitric acid in presence of aluminium hydroxide and use of solvent extraction for removal of fluorides and other bulk impurities to make uranium amenable for refining. It is a simple process requiring minimum process step and has advantage of lesser plant corrosion. This process can be applied for processing of uranium tetrafluoride generated from various sources like uranium by-product during thorium recovery from thorium concentrate, first stage product of uranium recovery from phosphoric acid by OPPA process and off grade uranium tetrafluoride material. The paper describes the details of the process developed and demonstrated on bench and pilot scale and its subsequent modification arising out of bulky solid waste generation. The modified process uses a lower quantity of aluminium hydroxide by allowing a lower dissolution of uranium per cycle and recycles the undissolved material to the next cycle, maintaining the overall recovery at high level. This innovation has reduced the solid waste generated by a factor of four at the cost of a slightly larger dissolution vessel and its increased corrosion rate. (author). 4 refs., 1 fig., 3 tabs.

Recovery of uranium from crude uranium tetrafluoride

International Nuclear Information System (INIS)

Ghosh, S.K.; Bellary, M.P.; Keni, V.S.

1994-01-01

An innovative process has been developed for recovery of uranium from crude uranium tetrafluoride cake. The process is based on direct dissolution of uranium tetrafluoride in nitric acid in presence of aluminium hydroxide and use of solvent extraction for removal of fluorides and other bulk impurities to make uranium amenable for refining. It is a simple process requiring minimum process step and has advantage of lesser plant corrosion. This process can be applied for processing of uranium tetrafluoride generated from various sources like uranium by-product during thorium recovery from thorium concentrate, first stage product of uranium recovery from phosphoric acid by OPPA process and off grade uranium tetrafluoride material. The paper describes the details of the process developed and demonstrated on bench and pilot scale and its subsequent modification arising out of bulky solid waste generation. The modified process uses a lower quantity of aluminium hydroxide by allowing a lower dissolution of uranium per cycle and recycles the undissolved material to the next cycle, maintaining the overall recovery at high level. This innovation has reduced the solid waste generated by a factor of four at the cost of a slightly larger dissolution vessel and its increased corrosion rate. (author)

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

International Nuclear Information System (INIS)

1978-01-01

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

The red bed-type and sandstone-type uranium deposits in the inland basins of the northwest China

International Nuclear Information System (INIS)

Wang Zhilong.

1988-01-01

On the basis of the study on the relationship between the red bed-type and sandstone-type uranium deposits in the inland basins of the northwest China, a classification of red beds based on sedimentary facies and redding origin is presented. Red beds in the inland badins can be divided into six types: 1. alluvial plain and 2. shallow lake red beds formed at the stage of continental disintegration; 3. fluvial alluvial red bed, 4. delta plain and 5. desert red beds formed at the diagenetic-epigenetic stage; 6. spattered red (secondaty red beds) formed at the hypergenic weathering stage. According to the characteristics, structural environments of these six types of red beds, and changes of various geochemical characteristic values (Eh, pH, Th/U, Fe 3+ /Fe 2+ , Sr/Ba, etc.) from host rocks to different kinds of red beds , the relationship between these values and sandstone-type uranium deposits was determined. it is an open system, the mobile uranium is easily leached, thus it is unfavoutable for mineralization; but when the rock reddens at the diagenetic epigenetic stage (closed system) that is favourable for mineraizaltion, the mobile uranium can be concentrated to form uranium deposits

Presence and Prevalence of Raffaelea lauricola, Cause of Laurel Wilt, in Different Species of Ambrosia Beetle in Florida, USA.

Science.gov (United States)

Ploetz, Randy C; Konkol, Joshua L; Narvaez, Teresa; Duncan, Rita E; Saucedo, Ramon J; Campbell, Alina; Mantilla, Julio; Carrillo, Daniel; Kendra, Paul E

2017-04-01

We summarize the information available on ambrosia beetle species that have been associated in Florida with Raffaelea lauricola T.C. Harr., Fraedrich & Aghayeva, the primary symbiont of Xyleborus glabratus Eichhoff and cause of laurel wilt. In total, 14 species in Ambrosiodmus, Euwallacea, Premnobius, Xyleborus, Xyleborinus, and Xylosandrus were either reared from laurel wilt-affected host trees or trapped in laurel wilt-affected stands of the same, and assayed for R. lauricola. In six collections from native species in the southeastern United States [Persea borbonia (L.), Persea palustris (Raf.) Sarg., and Persea humilis Nash] and four from avocado (Persea americana Mill.), extracted mycangia or heads (taxa with mandibular mycangia) or intact bodies (taxa with mycangia in other locations) were surface-disinfested before assays on a semi-selective medium for the isolation of Raffaelea (CSMA+). Raffaelea lauricola was identified based on its characteristic phenotype on CSMA+, and the identity of a random subset of isolates was confirmed with taxon-specific microsatellite markers. The pathogen was recovered from 34% (246 of 726) of the individuals that were associated with the native Persea spp., but only 6% (58 of 931) of those that were associated with avocado. Over all studies, R. lauricola was recovered from 10 of the ambrosia beetle species, but it was most prevalent in Xyleborus congeners. This is the first record of R. lauricola in Ambrosiodmus lecontei Hopkins, Xyleborinus andrewesi (Blandford), and Xyleborus bispinatus Eichhoff. The potential effects of R. lauricola's promiscuity are discussed. © The Authors 2017. Published by Oxford University Press on behalf of Entomological Society of America. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

Removal of U(VI) from aqueous solutions using Shewanella sp. RCRI7, isolated from Qurugoel Lake in Iran

Energy Technology Data Exchange (ETDEWEB)

Abdehvand, Adib Zaheri; Keshtkar, Alireza; Fatemi, Faezeh [Nuclear Science and Technology Research Institute, Tehran (Iran, Islamic Republic of). Nuclear Fuel Cycle Research School; Tarhiz, Vahideh; Hejazi, Mohammad Saeid [Tabriz Univ. of Medical Sciences (Iran, Islamic Republic of). Molecular Medicine Research Center

2017-04-01

Isolation, genotypic and phenotypic characterization of an aqueous bacterium, Shewanella sp RCRI7, from Qurugoel Lake in Iran and uranium removal from aqueous solutions using the isolate is described. Based on 16S rRNA gene sequence analysis and phylogenetic tree, strain RCRI7{sup T} falls into genus Shewanella. Closely related type strains include Shewanella xiamenensis S4{sup T} KJ542801, Shewanella profunda DSM15900{sup T} FR733713, Shewanella putrefaciens LMG 26268{sup T} X81623 and Shewanella oneidensis MR-1{sup T} AE014299. Anaerobic incubation of the bacteria in the presence of U(VI) led to uranium removal from the solution and formation of a black precipitate. Analysis of the precipitate using UV-vis confirmed the reduction of U(VI) to U(IV). The effects of pH, temperature, U(VI) concentration and cell density on uranium removal were elucidated. The maximum uranium removal was 97%. As a conclusion, the findings revealed the ability of the local strain RCRI7 for U(VI) bioreduction as an effective bacterium for uranium immobilization.

Removal of U(VI) from aqueous solutions using Shewanella sp. RCRI7, isolated from Qurugoel Lake in Iran

International Nuclear Information System (INIS)

Abdehvand, Adib Zaheri; Keshtkar, Alireza; Fatemi, Faezeh; Tarhiz, Vahideh; Hejazi, Mohammad Saeid

2017-01-01

Isolation, genotypic and phenotypic characterization of an aqueous bacterium, Shewanella sp RCRI7, from Qurugoel Lake in Iran and uranium removal from aqueous solutions using the isolate is described. Based on 16S rRNA gene sequence analysis and phylogenetic tree, strain RCRI7 T falls into genus Shewanella. Closely related type strains include Shewanella xiamenensis S4 T KJ542801, Shewanella profunda DSM15900 T FR733713, Shewanella putrefaciens LMG 26268 T X81623 and Shewanella oneidensis MR-1 T AE014299. Anaerobic incubation of the bacteria in the presence of U(VI) led to uranium removal from the solution and formation of a black precipitate. Analysis of the precipitate using UV-vis confirmed the reduction of U(VI) to U(IV). The effects of pH, temperature, U(VI) concentration and cell density on uranium removal were elucidated. The maximum uranium removal was 97%. As a conclusion, the findings revealed the ability of the local strain RCRI7 for U(VI) bioreduction as an effective bacterium for uranium immobilization.

In situ production of 36CI in uranium ore: a hydrogeological assessment tool

International Nuclear Information System (INIS)

Cornett, R.J.; Cramer, J.; Andrews, H.R.; Chant, L.A.; Davies, W.; Greiner, B.F.; Imahori, Y.; Koslowsky, V.; McKay, J.; Milton, G.M.; Milton, J.C.D.

1996-01-01

In situ neutron activation of 35 Cl within the rock and groundwater of geologic deposits that have elevated concentrations of uranium provides a hydrogeological tracer. We determine the production rate and mobility of 36 Cl in the 1.3-billion-year-old Cigar Lake uranium ore deposit. Accelerator mass spectrometry was used to map the Concentrations of 36 Cl in the ore and in the groundwater that were up to 100 times greater than those encountered in unmineralized portions of the host sandstone aquifer. The residence time of this mobile anion in groundwater within the mineralized zone ranged from 14 to 280 kyr. These residence times are consistent with the hydraulic and geochemical data, suggesting significant control of Cl - and groundwater movement by the clay-rich matrix of the mineralized zone. (author)

Analytical method of uranium (IV) and uranium (VI) in uranium ores and uranium-bearing rocks

International Nuclear Information System (INIS)

Shen Zhuqin; Zheng Yongfeng; Li Qingzhen; Zhong Miaolan; Gu Dingxiang

1995-11-01

The best conditions for keeping the original valences of uranium during the dissolution and separation procedure of geological samples (especially those micro uranium-bearing rock) were studied. With the exist of high concentration protectants, the sample was decomposed with concentration HF at 40 +- 5 degree C. The U(VI) was dissolved completely and formed stable complex UO 2 F 2 , the U(IV) was precipitated rapidly and carried by carrier. Quantitative separation was carried out immediately with suction. The decomposition of sample and separation of solid/liquid phases was completed within two minutes. After separation, the U(IV) and U(VI) were determined quantitatively with laser fluorescence or voltametry respectively according to the uranium content. The limit of detection for this method is 0.7 μg/g, RSD is 10.5%, the determinate range of uranium is 2 x 10 -6 ∼10 -1 g/g. The uranium contents and their valence state ratio were measured for more than one hundred samples of sand stone and granite, the accuracy and precision of these results are satisfactory for uranium geological research. (12 tabs.; 11 refs.)

Reduction of uranium hexafluoride to uranium tetrafluoride

International Nuclear Information System (INIS)

Chang, I.S.; Do, J.B.; Choi, Y.D.; Park, M.H.; Yun, H.H.; Kim, E.H.; Kim, Y.W.

1982-01-01

The single step continuous reduction of uranium hexafluoride (UF 6 ) to uranium tetrafluoride (UF 4 ) has been investigated. Heat required to initiate and maintain the reaction in the reactor is supplied by the highly exothermic reaction of hydrogen with a small amount of elemental fluorine which is added to the uranium hexafluoride stream. When gases uranium hexafluoride and hydrogen react in a vertical monel pipe reactor, the green product, UF 4 has 2.5g/cc in bulk density and is partly contaminated by incomplete reduction products (UF 5 ,U 2 F 9 ) and the corrosion product, presumably, of monel pipe of the reactor itself, but its assay (93% of UF 4 ) is acceptable for the preparation of uranium metal with magnesium metal. Remaining problems are the handling of uranium hexafluoride, which is easily clogging the flowmeter and gas feeding lines because of extreme sensitivity toward moisture, and a development of gas nozzel for free flow of uranium hexafluoride gas. (Author)

Precise coulometric titration of uranium in a high-purity uranium metal and in uranium compounds

International Nuclear Information System (INIS)

Tanaka, Tatsuhiko; Yoshimori, Takayoshi

1975-01-01

Uranium in uranyl nitrate, uranium trioxide and a high-purity uranium metal was assayed by the coulometric titration with biamperometric end-point detection. Uranium (VI) was reduced to uranium (IV) by solid bismuth amalgam in 5M sulfuric acid solution. The reduced uranium was reoxidized to uranium (VI) with a large excess of ferric ion at a room temperature, and the ferrous ion produced was titrated with the electrogenerated manganese(III) fluoride. In the analyses of uranium nitrate and uranium trioxide, the results were precise enough when the error from uncertainty in water content in the samples was considered. The standard sample of pure uranium metal (JAERI-U4) was assayed by the proposed method. The sample was cut into small chips of about 0.2g. Oxides on the metal surface were removed by the procedure shown by National Bureau of Standards just before weighing. The mean assay value of eleven determinations corrected for 3ppm of iron was (99.998+-0.012) % (the 95% confidence interval for the mean), with a standard deviation of 0.018%. The proposed coulometric method is simple and permits accurate and precise determination of uranium which is matrix constituent in a sample. (auth.)

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. The...

Uranium exploration

International Nuclear Information System (INIS)

De Voto, R.H.

1984-01-01

This paper is a review of the methodology and technology that are currently being used in varying degrees in uranium exploration activities worldwide. Since uranium is ubiquitous and occurs in trace amounts (0.2 to 5 ppm) in virtually all rocks of the crust of the earth, exploration for uranium is essentially the search of geologic environments in which geologic processes have produced unusual concentrations of uranium. Since the level of concentration of uranium of economic interest is dependent on the present and future price of uranium, it is appropriate here to review briefly the economic realities of uranium-fueled power generation. (author)

Uranium

International Nuclear Information System (INIS)

1982-01-01

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

Monitoring of uranium concentrations in water samples collected near potentially hazardous objects in North-West Tajikistan.

Science.gov (United States)

Zoriy, P; Schläger, M; Murtazaev, K; Pillath, J; Zoriy, M; Heuel-Fabianek, B

2018-01-01

The water contamination near ecologically problematic objects was investigated between 2009 and 2014 in North-West Tajikistan as a part of a joint project between Forschungszentrum Jülich and Khujand State University. The main part of this work was the determination of uranium in water samples collected near the Degmay tailings dump, the Taboshar pit lake and the Syr Darya river. More than 130 water samples were collected and analyzed to monitor the uranium concentration near the investigated areas. Two different mass spectrometers and an ion chromatograph were used for element concentration measurements. Based on the results obtained, the uranium influence of the Degmay tailings on the rivers Khoja-Bakyrgan-Say and Syr Darya and surrounding water was not found. The uranium concentration in water samples was monitored for a lengthy period at seven locations Great differences in the uranium concentration in waters collected in 2010, 2011, 2012, 2013 for each location were not observed. Drinking water samples from the region of North-West Tajikistan were analyzed and compared with the World Health Organization's guidelines. Seven out of nine drinking water samples near Taboshar exceeded the WHO guideline value for uranium concentrations (30 μg/L). The average uranium concentration of water samples from Syr Darya for the period from 2009 to 2014 was determined to be 20.1 (±5.2) μg/L. The uranium contamination of the Syr Darya was determined from the western border to the eastern border and the results are shown in this paper. Copyright © 2017 Elsevier Ltd. All rights reserved.

Influence of uranium hydride oxidation on uranium metal behaviour

International Nuclear Information System (INIS)

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

2013-01-01

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

Influence of uranium hydride oxidation on uranium metal behaviour

Energy Technology Data Exchange (ETDEWEB)

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

2013-07-01

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

SF6 ventilation study at Agnew Lake Mines, Ontario

International Nuclear Information System (INIS)

1979-03-01

In September 1978, James F. MacLaren Limited was awarded a contract by the Canada Centre for Mineral and Energy Technology (CANMET) to undertake a ventilation study at an underground uranium mine using sulphur hexafluoride (SF 6 ) as a tracer gas. The mine selected for the study was that of Agnew Lake Mines Limited in Northern Ontario. This is a relatively new mine with the combined mine/mill facilities first operational in mid-1977. Uranium is recovered from broken ore by in-situ leaching. The ventilation study was divided into two phases. A laboratory study was undertaken to develop a practical sampling technique, provide an evaluation of the logistics of long range sample transport and develop a laboratory analytical technique. Field programmes demonstrated the SF 6 tracer gas technique for mine ventilation trouble-shooting with the intent of providing information which will lead to more efficient use of existing mine ventilation capacity. This report outlines the findings of the laboratory study and the two field programmes

UMTRA project water sampling and analysis plan, Salt Lake City, Utah

International Nuclear Information System (INIS)

1994-06-01

Surface remedial action was completed at the Salt Lake City, Utah, Uranium Mill Tailings Remedial Action (UMTRA) Project site in the fall of 1987. Results of water sampling for the years 1992 to 1994 indicate that site-related ground water contamination occurs in the shallow unconfined aquifer (the uppermost aquifer). With respect to background ground water quality, contaminated ground water in the shallow, unconfined aquifer has elevated levels of chloride, sodium, sulfate, total dissolved solids, and uranium. No contamination associated with the former tailings pile occurs in levels exceeding background in ground water in the deeper confined aquifer. This document provides the water sampling and analysis plan for ground water monitoring at the former uranium processing site in Salt Lake City, Utah (otherwise known as the ''Vitro'' site, named after the Vitro Chemical Company that operated the mill). All contaminated materials removed from the processing site were relocated and stabilized in a disposal cell near Clive, Utah, some 85 miles west of the Vitro site (known as the ''Clive'' disposal site). No ground water monitoring is being performed at the Clive disposal site, since concurrence of the remedial action plan by the US Nuclear Regulatory Commission and completion of the disposal cell occurred before the US Environmental Protection Agency issued draft ground water standards in 1987 (52 FR 36000) for cleanup, stabilization, and control of residual radioactive materials at the disposal site. In addition, the likelihood of post-closure impact on the ground water is minimal to nonexistent, due to the naturally poor quality of the ground water. Water sampling activities planned for calendar year 1994 consist of sampling ground water from nine monitor wells to assess the migration of contamination within the shallow unconfined aquifer and sampling ground water from two existing monitor wells to assess ground water quality in the confined aquifer

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

International Nuclear Information System (INIS)

McKee, Paul; Snodgrass, William; Lush, D.L.; Ross, P.

1982-03-01

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

Uranium conversion; Urankonvertering

Energy Technology Data Exchange (ETDEWEB)

Oliver, Lena; Peterson, Jenny; Wilhelmsen, Katarina [Swedish Defence Research Agency (FOI), Stockholm (Sweden)

2006-03-15

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 UF{sub 6} and UF{sub 4} are present require equipment that is made of corrosion resistant material.

Polonium-210 accumulates in a lake receiving coal mine discharges-anthropogenic or natural?

Science.gov (United States)

Nelson, A W; Eitrheim, E S; Knight, A W; May, D; Wichman, M D; Forbes, T Z; Schultz, M K

2017-02-01

Coal is an integral part of global energy production; however, coal mining is associated with numerous environmental health impacts. It is well documented that coal-mine waste can contaminate the environment with naturally-occurring radionuclides from the uranium-238 ( 238 U) decay series. However, the behavior of the final radionuclide in the 238 U-series, i.e., polonium-210 ( 210 Po) arising from coal-mine waste-water discharge is largely unexplored. Here, results of a year-long (2014-2015) field study, in which the concentrations of 210 Po in sediments and surface water of a lake that receives coal-mine waste-water discharge in West Virginia are presented. Initial measurements identified levels of 210 Po in the lake sediments that were in excess of that which could be attributed to ambient U-series parent radionuclides; and were indicative of discharge site contamination of the lake ecosystem. However, control sediment obtained from a similar lake system in Iowa (an area with no coal mining or unconventional drilling) suggests that the levels of 210 Po in the lake are a natural phenomenon; and are likely unrelated to waste-water treatment discharges. Elevated levels of 210 Po have been reported in lake bottom sediments previously, yet very little information is available on the radioecological implications of 210 Po accumulation in lake bottom sediments. The findings of this study suggest that (Monthly Energy Review, 2016) the natural accumulation and retention of 210 Po in lake sediments may be a greater than previously considered (Chadwick et al., 2013) careful selection of control sites is important to prevent the inappropriate attribution of elevated levels of NORM in lake bottom ecosystems to industrial sources; and (Van Hook, 1979) further investigation of the source-terms and potential impacts on elevated 210 Po in lake-sediment ecosystems is warranted. Copyright © 2016 Elsevier Ltd. All rights reserved.

Lawrence Livermore Laboratory hydrogeochemical and stream sediment reconnaissance. Raw data report: Winnemucca Dry Lake Basin orientation study, Lovelock and Reno 10 x 20 NTMS area, Nevada

International Nuclear Information System (INIS)

Puchlik, K.P.; Holder, B.E.; Smith, C.F.

1978-01-01

This report presents the results of the Winnemucca Dry Lake Basin, Nevada, orientation study in the Lovelock and Reno 1 0 x 2 0 quadrangles of the National Topographic Map Series (NTMS). Wet, dry, and playa sediment samples were collected throughout the 597 km 2 semi-arid, closed basin. Water samples were collected at the few available streams and springs. In addition to neutron activation analysis for uranium and 15 to 20 trace elements on all samples, field and laboratory measurements were made on water samples. Analytical data and field measurements are presented in tabular hardcopy and fiche format. Eight full-size overlays for use with the Lovelock and Reno NTMS 1:250,000 quadrangles are included. Water sample site locations, water sample uranium concentration, sediment sample site locations, and sediment sample total uranium concentration are shown on the separate overlays. A general description of the area and the rock type distribution is presented. Some of the data in this report have been issued previously in ''Preliminary Report on the Winnemucca Dry Lake Basin Pilot Study,'' GJBX-41(76), August 1976

Study of immobilization of waste from treatment of acid waters of a uranium mining facility

International Nuclear Information System (INIS)

Goda, R.T.; Oliveira, A.P. de; Silva, N.C. da; Villegas, R.A.S.; Ferreira, A.M.

2017-01-01

This study aimed to produce scientific and technical knowledge aiming at the development of techniques to immobilize the waste generated in the treatment of acid waters in the UTM-INB Caldas uranium mining and processing facility using Portland cement. This residue (calcium diuranate - DUCA) contains uranium compounds and metal hydroxides in a matrix of calcium sulfate. It is observed that this material, in contact with the lake of acid waters of the mine's own pit, undergoes resolubilization and, therefore, changes the quality of the acidic water contained therein, changing the treatment parameters. For the study of immobilization of this residue, the mass of water contained in both the residue deposited in the pit of the mine and in the pulp resulting from the treatment of the acid waters was determined. In addition, different DUCA / CEMENT / WATER ratios were used for immobilization and subsequent mechanical strength and leaching tests. The results showed that in the immobilized samples with 50% cement mass condition, no uranium was detected in the leaching tests, and the mechanical strength at compression was 9.4 MPa, which indicates that more studies are needed, but indicate a good capacity to immobilize uranium in cement

Uranium

International Nuclear Information System (INIS)

Mackay, G.A.

1978-01-01

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

Second workshop on radon and radon daughters in urban communities associated with uranium mining and processing

International Nuclear Information System (INIS)

1979-01-01

A second meeting of Atomic Energy Control Board staff, federal and provincial government representatives, and consultants was held to discuss progress in reducing the concentrations of radon and its daughter products in houses in communities like Bancroft, Elliot Lake, Port Hope, and Uranium City. Participants discussed successful and unsuccessful remedial techniques, possible sources of radon, and methods of measuring radon and radon daughters in buildings

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.

Czechoslovak uranium

International Nuclear Information System (INIS)

Pluskal, O.

1992-01-01

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

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

International Nuclear Information System (INIS)

Milja, Thazhathuparambil Elias; Prathish, Krishnapillai Padmajakumari; Prasada Rao, Talasila

2011-01-01

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.

Uranium in Niger; L'uranium au Niger

Energy Technology Data Exchange (ETDEWEB)

Gabelmann, E

1978-03-15

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. [French] Le document presente la politique de l'Etat dans le cadre de la mise en valeur des ressources d'uranium, les societes minieres existantes et leurs productions, les projets d'exploitation d'uranium et les retombees economiques liees aux activites uraniferes et connexes.

Remediation of the closed-down uranium mine in Sweden

International Nuclear Information System (INIS)

Linder, P.; Sundblad, B.

1993-01-01

During the 1960s uranium was extracted from alum shale deposits at Ranstad in the south of Sweden. This mine was part of the development of a Swedish nuclear power program based on the heavy-water/natural uranium concept. In this report the history of Swedish uranium production is briefly presented as well as the reason for the closing-down of the mine at Ranstad. In 1985 the planning of the restoration of the area started. The aim of the remediation work was to find a permanent solution that excluded the need for any maintenance in the future. The procedures and techniques for remedial action are described for the open pit mine and the mill tailing deposits. As the leachate from the mill tailings was collected and purified, there was no urgent need for action. Investigations could be made to find an effective way for reducing the weathering of the pyrite in the tailings and the authorities concerned could accept the remediation plan after a detailed review. The main part of the plan has now been implemented and many experiences from the performance technique and the significant quality assurance program have been obtained. The old open pit mine has already been transformed into a lake and the mill tailings are covered by a leaktight barrier and a protective layer. The natural environment in the whole area has been reestablished

Uranium ores

International Nuclear Information System (INIS)

Poty, B.; Roux, J.

1998-01-01

The processing of uranium ores for uranium extraction and concentration is not much different than the processing of other metallic ores. However, thanks to its radioactive property, the prospecting of uranium ores can be performed using geophysical methods. Surface and sub-surface detection methods are a combination of radioactive measurement methods (radium, radon etc..) and classical mining and petroleum prospecting methods. Worldwide uranium prospecting has been more or less active during the last 50 years, but the rise of raw material and energy prices between 1970 and 1980 has incited several countries to develop their nuclear industry in order to diversify their resources and improve their energy independence. The result is a considerable increase of nuclear fuels demand between 1980 and 1990. This paper describes successively: the uranium prospecting methods (direct, indirect and methodology), the uranium deposits (economical definition, uranium ores, and deposits), the exploitation of uranium ores (use of radioactivity, radioprotection, effluents), the worldwide uranium resources (definition of the different categories and present day state of worldwide resources). (J.S.)

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

International Nuclear Information System (INIS)

Whitehead, W.

1986-09-01

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

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

International Nuclear Information System (INIS)

1977-08-01

Bolivia has an area of 1,098,580 square kilometers. Its capital is La Paz. The western part of the country is dominated by two ranges of the Andes Mountains, the Cordillera Occidental on the vest flank of the high plateau (Altiplano) and the Cordillera Real (or Oriental) on the east flank. The northern Andes average 5,486 meters in elevation; the southern Andes are not as lofty. The Altiplano is 3,658 to A,267 meters high and 129 km. in average width; it is the largest basin of inland drainage in South America and contains the renowned Lake Titicaca on the Peruvian-Bolivian border. The eastern tropical lowlands or pampas (Oriente) comprise about two-thirds of the country, with rain forest in the northern portion. An intermediate zone of valleys and basins lies between the eastern Andes and Oriente. Bolivia differs from other Andean countries, like Chile, Peru and Ecuador, in having large areas of Preeambrian schists, gneisses, migmatites and granites. These crop out in the eastern part of the country. Parts of these rocks contain banded iron formations (i.e., in the Muttin region) and are probably early Precambrian in age. Little systematic exploration for uranium was undertaken in Bolivia until the late 1960's. In 1967, 1968 and 1969 technical assistance was requested from, and provided by, the IAEA. This work led to evaluation of radioactive anomalies in veins of northeast Bolivia and in sandstones in the extreme southern part of the country. Although no uranium reserves are now credited to Bolivia, the geologic possibilities for several kinds of uranium deposits coupled with the relatively limited work done to date suggest that uranium orebodies will be discovered. It is estimated that the potential resources of Bolivia are in the range of 10,000 to 100,000 tonnes uranium

Detailed analysis of radon flux studies at Australian uranium projects

International Nuclear Information System (INIS)

Mudd, Gavin M.

2005-01-01

The release of radon gas and radon progeny from uranium projects is a major issue during operation as well as for the design of rehabilitation works. In Australia, there have been a number of premining radon flux studies as part of the environmental investigation and potential development of recent uranium projects. There is also an increasing amount of operational data on radon fluxes and loads from various aspects of projects, such as tailings, waste rock and mills. Thus there exists much useful measured data which can be used to assess the design radon flux and load targets for rehabilitation. The main projects for which radon data exists includes Ranger, Olympic Dam, Beverley, Honeymoon, Jabiluka, Yeelirrie, Lake Way, Koongarra, Moline, Coronation Hill, Rockhole, Nabarlek, Rum Jungle, Port Pirie and Ben Lomond. To date, much of this data has not been systematically evaluated. The need to compile and assess this data is twofold. Firstly, to assess the loads released from uranium production as an input into life-cycle analyses of the nuclear fuel cycle, such as those undertaken by UNSCEAR and industry groups. Secondly, there is a need to set suitable design standards for radon flux for the rehabilitation of former and current uranium projects. This paper will present such a detailed compilation of radon fluxes and loads which can then be used as the basis for both life-cycle analyses as well as setting appropriate site-specific rehabilitation criteria for radon. The implications for former and current projects is then discussed as well as future data needs. Ultimately, there is a critical need for thorough baseline surveys prior to mining to ensure accurate assessments of changes to radon fluxes and loads. The data and analysis presented is considered applicable to all uranium projects in Australia, as well as being a useful model for considering such issues internationally

Pengaruh Kandungan Uranium Dalam Umpan Terhadap Efisiensi Pengendapan Uranium

OpenAIRE

Torowati

2010-01-01

PENGARUH KANDUNGAN URANIUM DALAM UMPAN TERHADAP EFISIENSI PENGENDAPAN URANIUM. Setiap aktivitas analisis di Laboratorium Kendali Kualitas, Bidang Bahan Bakar Nuklir selalu dihasilkan limbah radioaktif cair. Limbah radioaktif cair di laboratorium masih mengandung uranium yang cukup besar ± 0,600 g U/l dengan keasamaan yang cukup besar pula. Karena uranium mempunyai nilai ekonomis yang cukup tinggi maka perlu USAha untuk mengambil kembali uranium tersebut. Pada kegiatan ini telah dilak...

The long-term effect of hydrogen on the UO2 spent fuel stability under anoxic conditions: Findings from the Cigar Lake Natural Analogue study

International Nuclear Information System (INIS)

Bruno, Jordi; Spahiu, Kastriot

2014-01-01

Highlights: • We have reviewed current information on the effect of hydrogen in UO 2 spent fuel. • We explored the radiolytic models generated in the Cigar Lake project. • The Cigar Lake data supports that H 2 reduces alpha radiolysis oxidants. • The results indicate the hydrogen effect is present after 100.000 years deposition. - Abstract: The present paradigm on UO 2 spent fuel stability under anoxic conditions assumes that the potential oxidative alteration of the matrix is suppressed in the presence of the hydrogen generated by the anoxic corrosion of iron by water. The observations from the Cigar Lake Natural Analogue project indicated the long-term stability of the uraninite ore under anoxic conditions and with substantial hydrogen generation. The radiolytic models developed in the analogue project have been used to test some of the hypothesis concerning the activation of hydrogen on the uranium(IV) oxide surface. Suggestions to pathways of radiolytic oxidant consumption by other processes than uranium dioxide or sulphide oxidation are presented. The stability of the ore body for billions of year indicates the presence of processes which neutralise radiolytic oxidants and one major factor may be the presence of dissolved hydrogen in the groundwaters contacting the ore body. The results from this test would indicate that hydrogen is activated on the surface of the Cigar Lake uraninites by alpha radiation consuming the generated radiolytic oxidants

Radionuclides and heavy metals in rainbow trout from Tsichomo, Nana Ka, Wen Povi, and Pin De Lakes in Santa Clara Canyon

International Nuclear Information System (INIS)

Fresquez, P.R.; Armstrong, D.R.; Naranjo, L. Jr.

1998-04-01

Radionuclide ( 3 H, 90 Sr, 137 Cs, 238 Pu, 239 Pu, and total uranium) and heavy metal (Ag, As, Ba, Be, Cd, Cr, Hg, Ni, Pb, Sb, Se, and TI) concentrations were determined in rainbow trout collected from Tsichomo, Nana Ka, Wen Povi, and Pin De lakes in Santa Clara Canyon in 1997. Most radionuclide and heavy metal concentrations in fish collected from these four lakes were within or just above upper limit background concentrations (Abiquiu reservoir), and as a group were statistically (p < 0.05) similar in most parameters to background

Scanning SRXF analysis and isotopes of uranium series from bottom sediments of Siberian lakes for high-resolution climate reconstructions

International Nuclear Information System (INIS)

Goldberg, E.L.; Grachev, M.A.; Chebykin, E.P.; Phedorin, M.A.; Kalugin, I.A.; Khlystov, O.M.; Zolotarev, K.V.

2005-01-01

High-resolution scanning X-ray Fluorescence Analysis with Synchrotron Radiation (SRXFA) was applied to investigate the downcore distribution of elements in Lake Baikal and Lake Teletskoye. Physical modeling of river runoff taking into account the chemistry of U series isotopes and their concentrations in sediments allowed a decade-scale reconstruction of Holocene (0-11 ky) river input to Lake Baikal. Holocene moisture peaks in East Siberia are synchronous with abrupt spells in the Atlantic. The multi-element data from Lake Teletskoye were used to predict the function of geochemical response to climate change in plainland Altai and to reconstruct the trends of annual (winter) air temperatures and atmospheric precipitation for the past 500 years

Uranium leaching from phosphatic sandstone and shale of Qatrani using citrate as a new leaching reagent

International Nuclear Information System (INIS)

Hussein, E.M.

1997-01-01

Uranium is found in Qatrani area (Southwest of Cairo and North of lake Qarun) in various forms in sedimentary rocks. Two important ore materials have been chosen for studying the recovery of their uranium contents namely; the phosphatic sandstone and the carbonaceous shale. The main emphasis in this thesis is the choice of an acid that would selectively leach uranium from thesis ores while leaving calcium phosphate and carbonate minerals minerals almost completely intact. Citric acid was indeed found advantageous due primarily to its strong ability to form stable complexes with uranium over a wide range of PH values beside the possibility of controlling thr solubility of calcium-bearing compounds by adding calcium citrate. The latter is actually characterized by its ability to exist in an unionized or associated from in citric acid solutions. From the general leaching characteristics of both uranium and P 2 O 5 from Qatrani phosphatic sandstone by citric acid, it was found that uranium could be completely leached beside the possibility of realizing a differential leaching percent values vs P 2 O 5 which is generally of limited solubility. Such a low solubility of P 2 O 5 has even been completely inhibited by providing calcium citrate to the citric acid solutions in amounts sufficient to exist in an optimum ionized non-associated state. Such a provision would render the solution unable to carry any further calcium ions thus the breakdown of the phosphate mineral was hindered while uranium has completely been selectively

Glances on uranium. From uranium in the earth to electric power

International Nuclear Information System (INIS)

Valsardieu, C.

1995-01-01

This book is a technical, scientific and historical analysis of the nuclear fuel cycle from the origin of uranium in the earth and the exploitation of uranium ores to the ultimate storage of radioactive wastes. It comprises 6 chapters dealing with: 1) the different steps of uranium history (discovery, history of uranium chemistry, the radium era, the physicists and the structure of matter, the military uses, the nuclear power, the uranium industry and economics), 2) the uranium in nature (nuclear structure, physical-chemical properties, radioactivity, ores, resources, cycle, deposits), 3) the sidelights on uranium history (mining, prospecting, experience, ore processing, resources, reserves, costs), 4) the uranium in the fuel cycle, energy source and industrial product (fuel cycle, fission, refining, enrichment, fuel processing and reprocessing, nuclear reactors, wastes management), 5) the other energies in competition and the uranium market (other uranium uses, fossil fuels and renewable energies, uranium market), and 6) the future of uranium (forecasting, ecology, economics). (J.S.)

Evaluación de la actividad antioxidante bioautográfica de cinco variedades de aceites esenciales andinos (Aristeguietia glutinosa; Myrcianthes rhopaloides; Ambrosia arborescens; Lantana camara; Minthostachys mollis)

OpenAIRE

Guerrero Toapanta, Priscila Pamela; Pozo Morales, Karla Natalia

2016-01-01

This experimental work had the goal of assessing the antioxidant capabilities of five essential oils: Minthostachys mollis, Aristeguietia glutinosa, Ambrosia arborescens, Myrcianthes rhopaloides and Lantana camara; all of which were obtained from the Ecuadorian Andes. This work used the DPPH and ABTS methods to assess free radical-capturing capacity, and it used the β-carotene Test to determine the antioxidant activity of each essential oil. The natural referent used herein...

Meeting of the French geological society - Uranium: geology, geophysics, chemistry. Book of abstracts; Reunion de la Societe Geologique de France - Uranium: geologie, geophysique, chimie. Recueil des resumes

Energy Technology Data Exchange (ETDEWEB)

Zakari, A.A.; Mima, S.; Bidaud, A.; Criqui, P.; Menanteau, P.; David, S.; Pagel, M.; Chagnes, A.; Cote, G.; Courtaud, B.; Thiry, J.; Miehe, J.M.; Gilbert, F.; Cuney, M.; Bruneton, P.; Ewington, D.; Vautrin-Ul, C.; Cannizzo, C.; Betelu, S.; Chausse, A.; Ly, J.; Bourgeois, D.; Maynadie, J.; Meyer, D.; Clavier, N.; Costin, D.T.; Cretaz, F.; Szenknect, S.; Ravaux, J.; Poinssot, C.; Dacheux, N.; Durupt, N.; Blanvillain, J.J.; Geffroy, F.; Aparicio, B.; Dubessy, J.; Nguyen-Trung, C.; Robert, P.; Uri, F.; Beaufort, D.; Lescuyer, J.L.; Morichon, E.; Allard, T.; Milesi, J.P.; Richard, A.; Rozsypal, C.; Mercadier, J.; Banks, D.A.; Boiron, M.C.; Cathelineau, M.; Dardel, J.; Billon, S.; Patrier, P.; Wattinne, A.; Vanderhaeghe, O.; Fabre, C.; Castillo, M.; Salvi, S.; Beziat, D.; Williams-Jones, A.E.; Trap, P.; Durand, C.; Goncalves, P.; Marquer, D.; Feybesse, J.L.; Richard, Y.; Orberger, B.; Hofmann, A.; Megneng, M.; Orberger, B.; Bouttemy, M.; Vigneron, J.; Etcheberry, A.; Perdicakis, M.; Prignon, N.; Toe, W.; Andre-Mayer, A.S.; Eglinger, A.; Jordaan, T.; Hocquet, S.; Ledru, P.; Selezneva, V.; Vendryes, G.; Lach, P.; Cuney, M.; Mercadier, J.; Brouand, M.; Duran, C.; Seydoux-Guillaume, A.M.; Bingen, B.; Parseval, P. de; Guillaume, D.; Bosse, V.; Paquette, J.L.; Ingrin, J.; Montel, J.M.; Giot, R.; Maucotel, F.; Hubert, S.; Gautheron, C.; Tassan-Got, L.; Pagel, M.; Barbarand, J.; Cuney, M.; Lach, P.; Bonhoure, J.; Leisen, M.; Kister, P.; Salaun, A.; Villemant, B.; Gerard, M.; Komorowski, J.C.; Michel, A.; Riegler, T.; Tartese, R.; Boulvais, P.; Poujols, M.; Gloaguen, E.; Mazzanti, M.; Mougel, V.; Nocton, G.; Biswas, B.; Pecaut, J.; Othmane, G.; Menguy, N.; Vercouter, T.; Morin, G.; Galoisy, L.; Calas, G.; Fayek, M.

2010-11-15

-temperature, and metallogenic provinces; 21 - Magmatic-hydrothermal transition in the Roessing pegmatite: implications for uranium mineralisation; 22 - Deformation and partial fusion of a Archean-paleo-Proterozoic crust: implication on uraniferous ores mobilization and deposition, Torngats orogenesis, Ungava bay; 23 - Black chert pebbles of the Pongola basin conglomerates ({approx}2, 9 Ga - South Africa): a potential uranium source?; 24 - origin and evolution of detrital pyrites in meso-Archean conglomerates (3.08-2.64 Ga) of South Africa: uranium source or trap?; 25 - Experimental study of U(VI) carbonates with respect to 3 parameters: pH, carbonate concentration, temperature, using vibrational (Raman, FTIR, ATR) and optical (UV-visible) spectroscopy; 26 - Nature and significance of the contact between the Abbabis gneiss complex and the meta-sedimentary sequences of the Damara orogenic belt; 27 - Metallogenic potentialities of Proterozoic orogenic belts accreted to Archean basements: the Damara/Lufilien orogen - Namibia and Zambia; 28 - Contribution of the Geological Exploration to the development of the KATCO ISR mine - Chu-Sarysu basin, Kazakhstan; 29 - Remarks about some remarkable events which occurred during the Francevillien formation; 30 - Geochemical signature of different mineral phases obtained by ICP-MS laser ablation (trace elements and rare earths): Application Uranium deposits; 31 - Role of fluids and irradiation in complex pegmatite euxenite/zircon assemblies from Norway and their U-Pb geochronological consequences; 32 - Mechanical modeling of rupture around metamictic minerals; 33 - Helium diffusion in apatite: Effect alpha recoil-linked damages; 34 - Rare earth spectra in uranium oxides: a marker of the uranium deposit type; 35 - Rare earths: tracers of uranium behaviour during acid sulphated hydrothermal weathering - the Guadeloupe example; 36 - What metallogenic model for the Kiggavik-Andrew Lake trend? Nunavut, Canada; 37 - Uranium mobility in the Southern

Uranium prospecting; La prospection de l'uranium

Energy Technology Data Exchange (ETDEWEB)

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

1955-07-01

This report is an instruction book for uranium prospecting. It appeals to private prospecting. As prospecting is now a scientific and technical research, it cannot be done without preliminary studies. First of all, general prospecting methods are given with a recall of fundamental geologic data and some general principles which are common with all type of prospecting. The peculiarities of uranium prospecting are also presented and in particular the radioactivity property of uranium as well as the special aspect of uranium ores and the aspect of neighbouring ores. In a third part, a description of the different uranium ores is given and separated in two different categories: primary and secondary ores, according to the place of transformation, deep or near the crust surface respectively. In the first category, the primary ores include pitchblende, thorianite and rare uranium oxides as euxenite and fergusonite for example. In the second category, the secondary ores contain autunite and chalcolite for example. An exhaustive presentation of the geiger-Mueller counter is given with the presentation of its different components, its functioning and utilization and its maintenance. The radioactivity interpretation method is showed as well as the elaboration of a topographic map of the measured radioactivity. A brief presentation of other detection methods than geiger-Mueller counters is given: the measurement of fluorescence and a chemical test using the fluorescence properties of uranium salts. Finally, the main characteristics of uranium deposits are discussed. (M.P.)

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)

1996-03-01

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

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

International Nuclear Information System (INIS)

Mahdy, M.A.

1988-01-01

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

Uranium

International Nuclear Information System (INIS)

Stewart, E.D.J.

1974-01-01

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.)

Uranium favorability of tertiary sedimentary rocks of the western Okanogan highlands and of the upper Columbia River valley, Washington. [Measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples; no known uranium deposits

Energy Technology Data Exchange (ETDEWEB)

Marjaniemi, D.K.; Robins, J.W.

1975-08-01

Tertiary sedimentary rocks in the northern portions of the western Okanogan highlands and in the upper Columbia River valley were investigated during a regional study to determine the favorability for potential uranium resources of the Tertiary sedimentary rocks of northeastern Washington. This project involved measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples. No portion of the project area of this report is rated of high or of medium favorability for potential uranium resources. Low favorability ratings are given to Oroville, Tonasket, and Pine Creek areas of the Okanogan River valley; to the Republic graben; and to the William Lakes, Colville, and Sheep Creek areas of the upper Columbia River valley. All these areas contain some fluvial, poorly sorted feldspathic or arkosic sandstones and conglomerates. These rocks are characterized by very low permeability and a consistently high siliceous matrix suggesting very low initial permeability. There are no known uranium deposits in any of these areas, and low level uranium anomalies are rare.

Uranium, depleted uranium, biological effects

International Nuclear Information System (INIS)

2001-01-01

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)

Solubility measurement of uranium in uranium-contaminated soils

International Nuclear Information System (INIS)

Lee, S.Y.; Elless, M.; Hoffman, F.

1993-08-01

A short-term equilibration study involving two uranium-contaminated soils at the Fernald site was conducted as part of the In Situ Remediation Integrated Program. The goal of this study is to predict the behavior of uranium during on-site remediation of these soils. Geochemical modeling was performed on the aqueous species dissolved from these soils following the equilibration study to predict the on-site uranium leaching and transport processes. The soluble levels of total uranium, calcium, magnesium, and carbonate increased continually for the first four weeks. After the first four weeks, these components either reached a steady-state equilibrium or continued linearity throughout the study. Aluminum, potassium, and iron, reached a steady-state concentration within three days. Silica levels approximated the predicted solubility of quartz throughout the study. A much higher level of dissolved uranium was observed in the soil contaminated from spillage of uranium-laden solvents and process effluents than in the soil contaminated from settling of airborne uranium particles ejected from the nearby incinerator. The high levels observed for soluble calcium, magnesium, and bicarbonate are probably the result of magnesium and/or calcium carbonate minerals dissolving in these soils. Geochemical modeling confirms that the uranyl-carbonate complexes are the most stable and dominant in these solutions. The use of carbonate minerals on these soils for erosion control and road construction activities contributes to the leaching of uranium from contaminated soil particles. Dissolved carbonates promote uranium solubility, forming highly mobile anionic species. Mobile uranium species are contaminating the groundwater underlying these soils. The development of a site-specific remediation technology is urgently needed for the FEMP site

Uranium complex recycling method of purifying uranium liquors

International Nuclear Information System (INIS)

Elikan, L.; Lyon, W.L.; Sundar, P.S.

1976-01-01

Uranium is separated from contaminating cations in an aqueous liquor containing uranyl ions. The liquor is mixed with sufficient recycled uranium complex to raise the weight ratio of uranium to said cations preferably to at least about three. The liquor is then extracted with at least enough non-interfering, water-immiscible, organic solvent to theoretically extract about all of the uranium in the liquor. The organic solvent contains a reagent which reacts with the uranyl ions to form a complex soluble in the solvent. If the aqueous liquor is acidic, the organic solvent is then scrubbed with water. The organic solvent is stripped with a solution containing at least enough ammonium carbonate to precipitate the uranium complex. A portion of the uranium complex is recycled and the remainder can be collected and calcined to produce U 3 O 8 or UO 2

Uranium favorability of tertiary sedimentary rocks of the western Okanogan highlands and of the upper Columbia River valley, Washington

International Nuclear Information System (INIS)

Marjaniemi, D.K.; Robins, J.W.

1975-08-01

Tertiary sedimentary rocks in the northern portions of the western Okanogan highlands and in the upper Columbia River valley were investigated during a regional study to determine the favorability for potential uranium resources of the Tertiary sedimentary rocks of northeastern Washington. This project involved measurement and sampling of surface sections, collection of samples from isolated outcrops, and chemical and mineralogical analyses of samples. No portion of the project area of this report is rated of high or of medium favorability for potential uranium resources. Low favorability ratings are given to Oroville, Tonasket, and Pine Creek areas of the Okanogan River valley; to the Republic graben; and to the William Lakes, Colville, and Sheep Creek areas of the upper Columbia River valley. All these areas contain some fluvial, poorly sorted feldspathic or arkosic sandstones and conglomerates. These rocks are characterized by very low permeability and a consistently high siliceous matrix suggesting very low initial permeability. There are no known uranium deposits in any of these areas, and low level uranium anomalies are rare

Uranium

International Nuclear Information System (INIS)

Toens, P.D.

1981-03-01

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

Exhaustible resources and economic growth: the case of uranium mining in Saskatchewan

International Nuclear Information System (INIS)

Campbell, H.F.

1984-09-01

This study examines the effect of a booming natural resource sector on regional economic growth, with particular attention to the impact of regional government policy on mineral rent taxation and the allocation of resource revenues. The author's approach is first to document the relevant theory and then to apply it to the case of the uranium industry in Saskatchewan. Governments often hold the view that a significant portion of resource rents flowing from the boom should be appropriated by the public sector. The usual arguments of efficiency and equity are explained, as is their applicability to uranium in Saskatchewan. The model is extended to include provincial tax and expenditure policies. Chapter 2 concentrates on mineral taxes and examines their various effects on the behaviour of firms with respect to exploration and extraction. The theory about the effects of mineral taxes on exploration and extraction is reviewed and is subsequently used to anticipate the effect of taxes on uranium mining. The Saskatchewan Uranium Royalty is explicitly considered in a quantitative model to analyse the effect on the rate of extraction on the Key Lake Mine. It is agreed that taxes collected by the Saskatchewan government are corrective in nature in that they lower the rate of extraction and make up for certain market failures and improve efficiency of resource use. It is not accepted, however, that the allocation of these taxes contributes to economic efficiency. Plentiful low cost uranium reserves are predicted but government policy is likely to limit rapid expansion. Weighing these factors and the world uranium market, uranium production forecasts are derived and an estimate is made of the impact of the industry on economic growth in Saskatchewan. The contribution to Gross Domestic Provincial Product in 2000 could be as high as 10% of the 1980 GDPP level and the contribution to employment as high as 9% of 1980 nonagricultural employment. The reader is cautioned that the

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.

Recovery of uranium from uranium bearing black shale

International Nuclear Information System (INIS)

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

2016-01-01

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

Uranium resources, 1983

International Nuclear Information System (INIS)

1983-01-01

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.)

Los Alamos Scientific Laboratory approach to hydrogeochemical and stream sediment reconnaissance for uranium in the United States

International Nuclear Information System (INIS)

Bolivar, S.L.

1981-01-01

The Los Alamos Scientific Laboratory of the United States is conducting a geochemical survey for uranium in the Rocky Mountain states of New Mexico, Colorado, Wyoming, and Montana and in Alaska. This survey is part of a national hydrogeochemical and stream sediment reconnaissance in which four Department of Energy laboratories will study the uranium resources of the United States to provide data for the National Uranium Resource Evaluation program. The reconnaissance will identify areas having higher than background concentrations of uranium in ground waters, surface waters, and water-transported sediments. Water and sediment samples are collected at a nominal density of one sample location per 10 km 2 except for lake areas of Alaska where the density is one sample location per 23 km 2 . Water samples are analyzed for uranium by fluorometry which has a 0.02 parts per billion lower limit of detection. Concentrations of 12 additional elements in water are determined by plasma-source emission spectrography. All sediments are analyzed for uranium by delayed-neutron counting with a 20 parts per billion lower limit of detection, which is well below the range of uranium concentrations in natural sediment samples. Elemental concentrations in sediments are also determined by neutron activation analysis for 31 elements by x-ray fluorescence for 9 elements, and by arc-source emission spectrography for 2 elements. The multielement analyses provide valuable data for studies concerning pathfinder elements, environmental pollution, elemental distributions, dispersion halos, and economic ore deposits other than uranium. To date, all of four Rocky Mountain states and about 80% of Alaska have been sampled. About 220,000 samples have been collected from an area of nearly 2,500,000 km 2

Uranium management activities

International Nuclear Information System (INIS)

Jackson, D.; Marshall, E.; Sideris, T.; Vasa-Sideris, S.

2001-01-01

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)

Provision by the uranium and uranium products

International Nuclear Information System (INIS)

Elagin, Yu.P.

2005-01-01

International uranium market is converted from the buyer market into the seller market. The prices of uranium are high and the market attempts to adapt to changing circumstances. The industry of uranium enrichment satisfies the increasing demands but should to increase ots capacities. On the whole the situation is not stable and every year may change the existing position [ru

Microplastic pollution in lakes and lake shoreline sediments - A case study on Lake Bolsena and Lake Chiusi (central Italy).

Science.gov (United States)

Fischer, Elke Kerstin; Paglialonga, Lisa; Czech, Elisa; Tamminga, Matthias

2016-06-01

Rivers and effluents have been identified as major pathways for microplastics of terrestrial sources. Moreover, lakes of different dimensions and even in remote locations contain microplastics in striking abundances. This study investigates concentrations of microplastic particles at two lakes in central Italy (Lake Bolsena, Lake Chiusi). A total number of six Manta Trawls have been carried out, two of them one day after heavy winds occurred on Lake Bolsena showing effects on particle distribution of fragments and fibers of varying size categories. Additionally, 36 sediment samples from lakeshores were analyzed for microplastic content. In the surface waters 2.68 to 3.36 particles/m(3) (Lake Chiusi) and 0.82 to 4.42 particles/m(3) (Lake Bolsena) were detected, respectively. Main differences between the lakes are attributed to lake characteristics such as surface and catchment area, depth and the presence of local wind patterns and tide range at Lake Bolsena. An event of heavy winds and moderate rainfall prior to one sampling led to an increase of concentrations at Lake Bolsena which is most probable related to lateral land-based and sewage effluent inputs. The abundances of microplastic particles in sediments vary from mean values of 112 (Lake Bolsena) to 234 particles/kg dry weight (Lake Chiusi). Lake Chiusi results reveal elevated fiber concentrations compared to those of Lake Bolsena what might be a result of higher organic content and a shift in grain size distribution towards the silt and clay fraction at the shallow and highly eutrophic Lake Chiusi. The distribution of particles along different beach levels revealed no significant differences. Copyright © 2016 Elsevier Ltd. All rights reserved.

Uranium industry framework

International Nuclear Information System (INIS)

Riley, K.

2008-01-01

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

High-temperature thermal conductivity of uranium chromite and uranium niobate

International Nuclear Information System (INIS)

Fedoseev, D.V.; Varshavskaya, I.G.; Lavrent'ev, A.V.; Oziraner, S.N.; Kuznetsova, D.G.

1979-01-01

The technique of determining thermal conductivity coefficient of uranium niobate and uranium chromite on heating with laser radiation is described. Determined is the coefficient of free-convective heat transfer (with provision for a conduction component) by means of a standard specimen. The thermal conductivity coefficients of uranium chromite and niobate were measured in the 1300-1700 K temperature range. The results are presented in a diagram form. It has been calculated, that the thermal conductivity coefficient for uranium niobate specimens is greater in comparison with uranium chromite specimens. The thermal conductivity coefficients of the materials mentioned depend on temperature very slightly. Thermal conductivity of the materials considerably depends on their porosity. The specimens under investigation were fabricated by the pressing method and had the following porosity: uranium chromite - 30 %, uranium niobate - 10 %. Calculation results show, that thermal conductivity of dense uranium chromite is higher than thermal conductivity of dense uranium niobate. The experimental error equals approximately 20 %, that is mainly due to the error of measuring the temperature equal to +-25 deg, with a micropyrometer

Study of reactions between uranium-plutonium mixed oxide and uranium nitride and between uranium oxide and uranium nitride; Etude des reactions entre l`oxyde mixte d`uranium-plutonium et le nitrure d`uranium et entre l`oxyde d`uranium et le nitrure d`uranium

Energy Technology Data Exchange (ETDEWEB)

Lecraz, C

1993-06-11

A new type of combustible elements which is a mixture of uranium nitride and uranium-plutonium oxide could be used for Quick Neutrons Reactors. Three different studies have been made on the one hand on the reactions between uranium nitride (UN) and uranium-plutonium mixed oxide (U,Pu)O{sub 2}, on the other hand on these between UN and uranium oxide UO{sub 2}. They show a sizeable reaction between nitride and oxide for the studied temperatures range (1573 K to 1973 K). This reaction forms a oxynitride compound, MO{sub x} N{sub y} with M=U or M=(U,Pu), whose crystalline structure is similar to oxide`s. Solubility of nitride in both oxides is studied, as the reaction kinetics. (TEC). 32 refs., 48 figs., 22 tabs.

Design guidelines for multi-seam mining at Elliot Lake

International Nuclear Information System (INIS)

Hedley, D.G.F.

1978-04-01

With the current expansion in uranium mining, multi-seam mining could again be practised at Elliot Lake as it was in the 1960s. Information on the dimensions of stopes, pillars, and parting zone was gathered from plans and sections of the relevant closed mines. Discussions were held with personnel familiar with these mines to establish instances of pillar, roof, and parting zone failures. Design guidelines are formulated for stope and pillar dimensions in multi-seam mining for a range of orebody configurations using past practice in a back-analysis approach. Constraints imposed by dip and seam thickness on the choice of equipment and mining layout are evaluated. An attempt is made to bring together the engineering aspects, including rock mechanics, of multi-seam mine design with uranium recovery and other economic factors for three alternative mine layouts: single-seam mining, double-seam mining, and seams-and-parting mining. A series of examples are worked through, showing how the design guidelines can be applied for typical orebody configurations