A study on the decontamination of the gravels contaminated by uranium

Energy Technology Data Exchange (ETDEWEB)

Park, Ukryang; Kim, Gyenam; Kim, Seungsoo; Moon, Jaikwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-05-15

The amount of gravels contaminated by uranium is usually about 10% of the contaminated soil. Since such contaminated gravels show different kinds and volumes, it would cost a considerable amount of money if they are to be disposed of without going through any special process. Also, there has not been any particular way or technology for processing the gravels contaminated by uranium. Therefore, various fundamental experiments and researches have been carried out for the decontamination of the gravels contaminated by uranium. Through such experiments and researches, it has been possible to obtain some significant results. The acid cleaning process, which is based on the application of the soil cleaning method, can be regarded as one of the major ways used for decontamination. When the gravels contaminated by uranium are cleaned as they are, most of them tend to show an extremely-low level of decontamination. Therefore, it could be said that the inside of each gravel is also contaminated by uranium. As a result, the gravels contaminated by uranium need to be crushed before being cleaned, which would result in a higher level of efficiency for decontamination compared to the previous way. Therefore, it is more effective to crush the subject gravels before cleaning them in terms of decontamination. However, such test results can only be applied to the gravels contaminated by an average level of uranium concentration. Regarding the gravels showing a higher level of uranium concentration than the average, it is still necessary to carry out more researches. Therefore, this study focused on the level of efficiency for decontamination after the contaminated gravels were crushed before being cleaned, in order to find a way to effectively dispose of the gravels contaminated by high-concentration uranium and secure a high level of efficiency for decontamination. In order to decontaminate the gravels which were contained in the soil contaminated by uranium and showed a higher

Medical effects of internal contamination with uranium.

Science.gov (United States)

Duraković, A

1999-03-01

The purpose of this work is to present an outline of the metabolic pathways of uranium isotopes and compounds, medical consequences of uranium poisoning, and an evaluation of the therapeutic alternatives in uranium internal contamination. The chemical toxicity of uranium has been recognized for more than two centuries. Animal experiments and human studies are conclusive about metabolic adverse affects and nephro- toxicity of uranium compounds. Radiation toxicity of uranium isotopes has been recognized since the beginning of the nuclear era, with well documented evidence of reproductive and developmental toxicity, as well as mutagenic and carcinogenic consequences of uranium internal contamination. Natural uranium (238U), an alpha emitter with a half-life of 4.5x10(9) years, is one of the primordial substances of the universe. It is found in the earth's crust, combined with 235U and 234U, alpha, beta, and gamma emitters with respective half-lives of 7.1x10(8) and 2.5x10(5) years. A special emphasis of this paper concerns depleted uranium. The legacy of radioactive waste, environmental and health hazards in the nuclear industry, and, more recently, the military use of depleted uranium in the tactical battlefield necessitates further insight into the toxicology of depleted uranium. The present controversy over the radiological and chemical toxicity of depleted uranium used in the Gulf War warrants further experimental and clinical investigations of its effects on the biosphere and human organisms.

Remediation of soils contaminated with particulate depleted uranium by multi stage chemical extraction.

Science.gov (United States)

Crean, Daniel E; Livens, Francis R; Sajih, Mustafa; Stennett, Martin C; Grolimund, Daniel; Borca, Camelia N; Hyatt, Neil C

2013-12-15

Contamination of soils with depleted uranium (DU) from munitions firing occurs in conflict zones and at test firing sites. This study reports the development of a chemical extraction methodology for remediation of soils contaminated with particulate DU. Uranium phases in soils from two sites at a UK firing range, MOD Eskmeals, were characterised by electron microscopy and sequential extraction. Uranium rich particles with characteristic spherical morphologies were observed in soils, consistent with other instances of DU munitions contamination. Batch extraction efficiencies for aqueous ammonium bicarbonate (42-50% total DU extracted), citric acid (30-42% total DU) and sulphuric acid (13-19% total DU) were evaluated. Characterisation of residues from bicarbonate-treated soils by synchrotron microfocus X-ray diffraction and X-ray absorption spectroscopy revealed partially leached U(IV)-oxide particles and some secondary uranyl-carbonate phases. Based on these data, a multi-stage extraction scheme was developed utilising leaching in ammonium bicarbonate followed by citric acid to dissolve secondary carbonate species. Site specific U extraction was improved to 68-87% total U by the application of this methodology, potentially providing a route to efficient DU decontamination using low cost, environmentally compatible reagents. Copyright © 2013 The Authors. Published by Elsevier B.V. All rights reserved.

Feasibility testing of in situ vitrification of uranium-contaminated soils

International Nuclear Information System (INIS)

Ikuse, H.; Tsuchino, S.; Tasaka, H.; Timmerman, C.L.

1989-01-01

Process feasibility studies using in situ vitrification (ISV) were successfully performed on two different uranium-contaminated wastes. In situ vitrification is a thermal treatment process that converts contaminated soils into durable glass and crystalline form. Of the two different wastes, one waste was uranium mill tailings, while the other was uranium-contaminated soils which had high water contents. Analyses of the data from the two tests are presented

Activity concentration of uranium in groundwater from uranium mineralized areas and its neighborhood

International Nuclear Information System (INIS)

Arabi, S.A.; Funtua, I.I.; Dewu, B.B.M.; Alagbe, S.A.; Garba, M.L.; Kwaya, M.Y.; Baloga, A.D.

2013-01-01

Uranium mineralization in parts of northeastern Nigeria necessitated its exploration during early eighties by the Nigeria Uranium Mining Company (NUMCO) which was later abandoned. During their course of decay, uranium isotopes pass through radioactive decay stage and eventually into stable isotope of lead. The course of concern for soluble uranium in groundwater especially from the mineralized areas include ionizing radiation, chemical toxicity and reproductive defects for which ingested uranium has been implicated to have caused. This study is aimed at assessing the levels of concentration of uranium in groundwater to ascertain its compliance with the World Health Organization's (WHO) and the United State Environmental Protection Agency's (EPA) guideline for uranium in drinking water. Thirty five groundwater samples were collected using EPA's groundwater sampling protocol and analyzed at the Department of Geology, University of Cape Town using an Inductively Coupled Plasma Mass Spectrometric (ICP-MS) technique. Significant finding of this work was that there is radiological contamination of groundwater in the area. There is also an indication that the extent of radiological contamination is not much within the mineralized zones, therefore, there is likelihood that groundwater has acted as a medium of transporting and enhancing uranium in groundwater in an environment away from that of origin. About 5.7 % of the samples studied had uranium concentration above WHO and EPA's maximum contaminant level of 30 μg/L which is a major concern for inhabitants of the area. It was also apparent that radiological contamination at the southwestern part of the study area extends into the adjacent sheet (sheet 152). Uranium concentration above set standards in those areas might have originated from rocks around established mineralized zones but was transported to those contaminated areas by groundwater that leaches across the host rock and subsequently mobilizing soluble uranium

Remediation of soils contaminated with particulate depleted uranium by multi stage chemical extraction

Energy Technology Data Exchange (ETDEWEB)

Crean, Daniel E. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield (United Kingdom); Centre for Radiochemistry Research, School of Chemistry, The University of Manchester (United Kingdom); Livens, Francis R.; Sajih, Mustafa [Centre for Radiochemistry Research, School of Chemistry, The University of Manchester (United Kingdom); Stennett, Martin C. [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield (United Kingdom); Grolimund, Daniel; Borca, Camelia N. [Swiss Light Source, Paul Scherrer Institute, Villigen (Switzerland); Hyatt, Neil C., E-mail: n.c.hyatt@sheffield.ac.uk [Immobilisation Science Laboratory, Department of Materials Science and Engineering, The University of Sheffield (United Kingdom)

2013-12-15

Highlights: • Batch leaching was examined to remediate soils contaminated with munitions depleted uranium. • Site specific maximum extraction was 42–50% total U in single batch with NH{sub 4}HCO{sub 3}. • Analysis of residues revealed partial leaching and secondary carbonate phases. • Sequential batch leaching alternating between NH{sub 4}HCO{sub 3} and citric acid was designed. • Site specific extraction was increased to 68–87% total U in three batch steps. -- Abstract: Contamination of soils with depleted uranium (DU) from munitions firing occurs in conflict zones and at test firing sites. This study reports the development of a chemical extraction methodology for remediation of soils contaminated with particulate DU. Uranium phases in soils from two sites at a UK firing range, MOD Eskmeals, were characterised by electron microscopy and sequential extraction. Uranium rich particles with characteristic spherical morphologies were observed in soils, consistent with other instances of DU munitions contamination. Batch extraction efficiencies for aqueous ammonium bicarbonate (42–50% total DU extracted), citric acid (30–42% total DU) and sulphuric acid (13–19% total DU) were evaluated. Characterisation of residues from bicarbonate-treated soils by synchrotron microfocus X-ray diffraction and X-ray absorption spectroscopy revealed partially leached U(IV)-oxide particles and some secondary uranyl-carbonate phases. Based on these data, a multi-stage extraction scheme was developed utilising leaching in ammonium bicarbonate followed by citric acid to dissolve secondary carbonate species. Site specific U extraction was improved to 68–87% total U by the application of this methodology, potentially providing a route to efficient DU decontamination using low cost, environmentally compatible reagents.

Persistence of uranium groundwater plumes: Contrasting mechanisms at two DOE sites in the groundwater-river interaction zone

Science.gov (United States)

Zachara, John M.; Long, Philip E.; Bargar, John; Davis, James A.; Fox, Patricia; Fredrickson, Jim K.; Freshley, Mark D.; Konopka, Allan E.; Liu, Chongxuan; McKinley, James P.; Rockhold, Mark L.; Williams, Kenneth H.; Yabusaki, Steve B.

2013-04-01

We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influence plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences between the sites include the geochemical nature of

Uranium removal during low discharge in the Ganges-Brahmaputra mixing zone

International Nuclear Information System (INIS)

Carroll, J.; Moore, W.S.

1993-01-01

The Ganges-Brahmaputra river system supplies more dissolved uranium to the ocean than any other system in the world (Sarin et al., 1990; Sackett et al., 1973). However, there have been no investigations to determine whether riverine supplies of uranium are altered by geochemical reactions in the river-ocean mixing zone. In this study, uranium and salinity data were collected in the Ganges-Brahmaputra mixing zone during a period of low river discharge. The uranium distribution with salinity shows that in waters <12 ppt salinity, uranium activities are significantly lower than predicted from conservative mixing of river and seawater. This suggests that uranium is being removed within the mixing zone. The behavior of uranium in the Ganges-Brahmaputra is in sharp contrast to its behavior in the Amazon mixing zone where McKee et al. (1978) found uranium activities significantly higher than predicted from conservative mixing. The contrasting behaviors for uranium in these systems are due to the different locations where mixing between river and seawater occurs. For the Amazon, mixing takes place on the continental shelf whereas for the Ganges-Brahmaputra, mixing occurs within shoreline sedimentary environments. The physiochemical processes controlling uranium removal to sediment deposits in the Amazon are partly known. The authors discuss mechanisms which may be removing uranium to suspended and mangrove sediments in the Ganges-Brahmaputra

Assessment of trace ground-water contaminants release from south Texas in-situ uranium solution-mining sites

Energy Technology Data Exchange (ETDEWEB)

Kidwell, J.R.; Humenick, M.J.

1981-01-01

The future of uranium solution mining in south Texas depends heavily on the industry's ability to restore production zone ground water to acceptable standards. This study investigated the extent of trace contaminant solubilization during mining and subsequent restoration attempts, first through a literature search centered on uranium control mechanisms, and then by laboratory experiments simulating the mining process. The literature search indicated the complexity of the situation. The number of possible interactions between indigenous elements and materials pointed on the site specificity of the problem. The column studies evaluated three different production area ores. Uranium, molybdenum, arsenic, vanadium, and selenium were analyzed in column effluents. After simulated mining operations were completed, uranium was found to be the most persistent trace element. However, subsequent ground water flushing of the columns could restore in-situ water to EPA recommended drinking water concentrations. Limited data indicated that ground water flowing through mined areas may solubilize molybdenum present in down gradient areas adjacent to the production zone due to increased oxidation potential of ground water if adequate restoration procedures are not followed.

Applications of electrical resistivity measurements to research into the purification of uranium using floating molten zone by electronic bombardment; Applications des mesures de resistivite electrique a l'etude de la purification de l'uranium par fusion de zone flottante par bombardement electronique

Energy Technology Data Exchange (ETDEWEB)

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

1964-02-01

The purification of uranium has been achieved by zone melting. Because of the high affinity of uranium towards elements such as oxygen, contamination has been avoided by adopting the floating zone technique and by working under high vacuum. The difficulties created by the deformations of uranium rod, which are caused by anisotropy of dilatation of phases {alpha} and {beta} and allotropic transformations {alpha} {r_reversible} {beta} and {beta} {r_reversible} {alpha}, have been overcome by the use of electron bombardment stabilized by feedback. A rough control of the purification was obtained by micrographic examination, microhardness measurements, and tests of secondary recrystallization, allowed us to appreciate the new degree of purity of the uranium obtained. The investigation of the purity degree was pursued by electrical resistivity measurements at 20 deg. K. But one had to take care in the interpretation of those measurements of the anisotropy of the uranium resistivity and the influence of structure on residual resistivity. Those measurements have led us, by determination of single crystal and uranium resistivity, to be able to distinguish between the principal resistivity against axis [100] and [010]. (author) [French] La purification de l'uranium a ete realisee par l'application de la methode dite de la zone fondue. L'uranium etant particulierement reactif vis-a-vis d'elements tels que l'oxygene, les risques de contamination ont ete supprimes en adoptant la technique de la zone flottante et en operant sous vide eleve. Les difficultes creees par les deformations du barreau d'uranium, dues a l'anisotropie de dilatation des phases {alpha} et {beta} et ou passage des deux points de transformation allotropiques {alpha} {r_reversible} {beta} et {beta} {r_reversible} {alpha}, ont pu etre surmontees par l'emploi du chauffage par bombardement electronique, stabilise par un systeme tres simple de contre reaction. Un premier controle de la purification effectue par

Uranium uptake and accumulation in plants from soil contaminated with uranium in different concentrations

International Nuclear Information System (INIS)

Zhao Luxue; Tang Yongjin; Luo Xuegang

2014-01-01

The plants of Medicago sativa L., Hibiscus esulentus L, Waterspinach, Amaranthus retroflexus and Abutilon theophrasti Medic were employed as the indicator to investigate the uranium uptake and accumulation from soils contaminated with uranium (UO_2 (CH_3COO)_2 · 2H_2O) of 25 mg · kg"-"l, 75 mg · kg"-"1, 125 mg · kg"-"l, 175 mg · kg"-"l respectively, in a pot experiment. The result shows that, U concentration in the aerial part and underground part of the whole plant increased with the rise of uranium concentration in the soils. In the contaminated soils with 25∼125 mg · kg"-"l concentrations of uranium, U content of Medicago sativa L is the highset (6.78 mg · kg"-"l, 61.53 mg · kg"-"l, 74.06 mg · kg"-"l separately). While in the 175 mg · kg"-"l concentration of uranium contaminated soils, U content of Hibiscus esulentus L is the highest (86.72 mg · kg"-"1), which is mainly because of U concentration in its roots have higher level of uranium (388.16 mg · kg"-"l). Comprehensive analysis shows that Medicago sativa L. is a good plant for phytoextraction and Hibiscus esulentus L is a good immobilizing plant for phytoremediation. The results can provide some theoretical basis and technical support for remedying U-contaminated soils in different areas of our country. (authors)

A review of possible origins of the uranium 'plume' in the aquifer under the EPIC site in the Chernobyl Exclusion Zone

Energy Technology Data Exchange (ETDEWEB)

Simonucci, C.; Van Meir, N.; Courbet, C. [Institute for Radioprotection and Nuclear Safety, PRP-DGE/SRTG/LETIS, POB 17, F-92262, Fontenay-aux-Roses Cedex (France); Roux, C. [Institute for Radioprotection and Nuclear Safety, PRP-DGE/SRTG/LETIS, POB 17, F-92262, Fontenay-aux-Roses Cedex (France); Aix-Marseille University, CNRS, IRD, CEREGE UM34, 13545 Aix en Provence (France); Le Gal La Salle, C.; Verdoux, P.; Lancelot, J.C. [Nimes University, Laboratoire de Geochimie Isotopique (GIS), 150 rue George Besse, 30035 Nimes (France); Ruas, A. [CEA, Nuclear Energy Division, RadioChemistry and Processes Department, F-30207, Bagnols-sur-Ceze (France); Bassot, S. [Institute for Radioprotection and Nuclear Safety, PRP-DGE/SRTG/LAME, POB 17, F-92262, Fontenay-aux-Roses Cedex (France); Bugai, D. [Institute of Geological Sciences, 55-b, Gonchara Str., Kiev 01054 (Ukraine); Levchuk, S.; Kashparov, V. [Ukrainian Institute of Agricultural Radiology, UIAR NUBiP of Ukraine, Mashinobudivnykiv str. 7, Chabany, Kyiv-Svjatoshin (Ukraine)

2013-07-01

The uniqueness of the Chernobyl accident lies in the fact that so much radioactive material was discharged to the atmosphere as solid fuel particles from the reactor core. Between the 26 April and the 6 May 1986 more than 6 tons of small particles of highly radioactive uranium oxide fuel were discharged to the atmosphere and were responsible for more than 75 % of the radioactive contamination on the ground in the exclusion zone. In 1987, about 800 trenches had been dug in the exclusion zone to prevent re-suspension and to protect workers from contamination. In 1999, the IRSN, in collaboration with IGS and UIAR, equipped trench 22 (CPS) in order to monitor radionuclide migration in the environment (water, soil, plants). At the EPIC site high uranium concentrations were observed in the groundwater downstream from trench 22. We discuss the possible origins of this uranium 'plume'. (authors)

Total effective dose equivalent associated with fixed uranium surface contamination

International Nuclear Information System (INIS)

Bogard, J.S.; Hamm, R.N.; Ashley, J.C.; Turner, J.E.; England, C.A.; Swenson, D.E.; Brown, K.S.

1997-04-01

This report provides the technical basis for establishing a uranium fixed-contamination action level, a fixed uranium surface contamination level exceeding the total radioactivity values of Appendix D of Title 10, Code of Federal Regulations, part 835 (10CFR835), but below which the monitoring, posting, and control requirements for Radiological Areas are not required for the area of the contamination. An area of fixed uranium contamination between 1,000 dpm/100 cm 2 and that level corresponding to an annual total effective dose equivalent (TEDE) of 100 mrem requires only routine monitoring, posting to alert personnel of the contamination, and administrative control. The more extensive requirements for monitoring, posting, and control designated by 10CFR835 for Radiological Areas do not have to be applied for these intermediate fixed-contamination levels

Natural uranium toxicology - evaluation of internal contamination in man

International Nuclear Information System (INIS)

Chalabreysse, J.

1968-01-01

After reminding the physical and chemical properties of natural uranium which might affect its toxicology, a comprehensive investigation upon natural uranium metabolism and toxicity and after applying occupational exposure standards to this particular poison, it has been determined, from accident reports and human experience reported in the related literature, a series of formulae obtained by theoretical mathematical development giving principles for internal contamination monitoring and disclosure by determining uranium in the urine of occupationally exposed individuals. An assay is performed to determine individual internal contamination according to the various contamination cases. The outlined purposes, mainly practical, required some options and extrapolations. The proposed formula allows a preliminary approach and also to determine shortly a contamination extent or to discuss the systematical urinalysis results as compared with individual radio-toxicology monitoring professional standards. (author) [fr

The measurement test of uranium in a uranium-contaminated waste by passive gamma-rays measurement method

CERN Document Server

Sukegawa, Y; Ohki, K; Suzuki, S; Yoshida, M

2002-01-01

This report is completed about the measurement test and the proofreading of passive gamma - rays measurement method for Non - destructive assay of uranium in a uranium-contaminated waste. The following are the results of the test. 1) The estimation of the amount of uranium by ionization survey meter is difficult for low intensity of gamma-rays emitted from uranium under about 50g. 2) The estimation of the amount of uranium in the waste by NaI detector is possible in case of only uranium, but the estimation from mixed spectrums with transmission source (60-cobalt) is difficult to confirm target peaks. 3) If daughter nuclides of uranium and thorium chain of uranium ore exist, measurement by NaI detector is affected by gamma-rays from the daughter nuclides seriously-As a result, the estimation of the amount of uranium is difficult. 4) The measurement of uranium in a uranium-contaminated waste by germanium detector is possible to estimate of uranium and other nuclides. 5) As to estimation of the amount of uranium...

Operating and life-cycle costs for uranium-contaminated soil treatment technologies

International Nuclear Information System (INIS)

Douthat, D.M.; Armstrong, A.Q.

1995-09-01

The development of a nuclear industry in the US required mining, milling, and fabricating a large variety of uranium products. One of these products was purified uranium metal which was used in the Savannah River and Hanford Site reactors. Most of this feed material was produced at the US Department of Energy (DOE) facility formerly called the Feed Materials Production Center at Fernald, Ohio. During operation of this facility, soils became contaminated with uranium from a variety of sources. To avoid disposal of these soils in low-level radioactive waste burial sites, increasing emphasis has been placed on the remediating soils contaminated with uranium and other radionuclides. To address remediation and management of uranium-contaminated soils at sites owned by DOE, the DOE Office of Technology Development (OTD) evaluates and compares the versatility, efficiency, and economics of various technologies that may be combined into systems designed to characterize and remediate uranium-contaminated soils. Each technology must be able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from soil, (3) treat or dispose of resulting waste streams, (4) meet necessary state and federal regulations, and (5) meet performance assessment objectives. The role of the performance assessment objectives is to provide the information necessary to conduct evaluations of the technologies. These performance assessments provide the basis for selecting the optimum system for remediation of large areas contaminated with uranium. One of the performance assessment tasks is to address the economics of full-scale implementation of soil treatment technologies. The cost of treating contaminated soil is one of the criteria used in the decision-making process for selecting remedial alternatives

Removal of uranium from uranium-contaminated soils -- Phase 1: Bench-scale testing

International Nuclear Information System (INIS)

Francis, C.W.

1993-09-01

To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil's physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques

Immobilization of uranium in contaminated soil by natural apatite addition

International Nuclear Information System (INIS)

Mrdakovic Popic, Jelena; Stojanovic, Mirjana; Milosevic, Sinisa; Iles, Deana; Zildzovic, Snezana

2007-01-01

Available in abstract form only. Full text of publication follows: The goal of this study was to evaluate the effectiveness of Serbian natural mineral apatite as soil additive for reducing the migration of uranium from contaminated sediments. In laboratory study we investigated the sorption properties of domestic apatite upon different experimental conditions, such as pH, adsorbent mass, reaction period, concentration of P 2 O 5 in apatite, solid/liquid ratio. In second part of study, we did the quantification of uranium in soil samples, taken from uranium mine site 'Kalna', by sequential extraction method. The same procedure was, also, used for uranium determination in contaminated soil samples after apatite addition, in order to determine the changes in U distribution in soil fraction. The obtained results showed the significant level of immobilization (96.7%) upon certain conditions. Increase of %P 2 O 5 in apatite and process of mechano-chemical activation led to increase of immobilization capacity from 17.50% till 91.64%. The best results for uranium binding were obtained at pH 5.5 and reaction period 60 days (98.04%) The sequential extraction showed the presence of uranium (48.2%) in potentially available soil fractions, but with the apatite addition uranium content in these fractions decreased (30.64%), what is considering environmental aspect significant fact. In situ immobilization of radionuclide using inexpensive sequestering agents, such as apatite, is very adequate for big contaminated areas of soil with low level of contamination. This investigation study on natural apatite from deposit 'Lisina' Serbia was the first one of this type in our country. Key words: apatite, uranium, immobilization, soil, contamination. (authors)

Study on phytoremediation in the uranium contaminated environment

International Nuclear Information System (INIS)

Huang Dejuan; Zhu Yean; Hua Rong; Yu Yue; Luo Mingbiao; Liu Qingcheng; Huang Dechao

2012-01-01

Mechanisms of phytoremediation in the uranium contaminated environment are described, and a worldwide overview of the content and progress of the related research topics is provided. Based on the analysis, it is pointed out that we should strengthen the research of plant-microbial coexistence system as well as the research of the related molecular biology and genetic engineering in order to enhance the phytoremediation's efficiency in the uranium contaminated environment. (authors)

Uranium: properties and biological effects after internal contamination

International Nuclear Information System (INIS)

Souidi, M.; Tissandie, E.; Racine, R.; Ben Soussan, H.; Rouas, C.; Grignard, E.; Dublineau, I.; Gourmelon, P.; Lestaevel, P.; Gueguen, Y.

2009-01-01

Uranium is a radionuclide present in the environment since the origin of the Earth. In addition to natural uranium, recent deposits from industrial or military activities are acknowledged. Uranium's toxicity is due to a combination of its chemical (heavy metal) and radiological properties (emission of ionizing radiations). Acute toxicity induces an important weight loss and signs of renal and cerebral impairment. Alterations of bone growth, modifications of the reproductive system and carcinogenic effects are also often seen. On the contrary, the biological effects of a chronic exposure to low doses are unwell known. However, results from different recent studies suggest that a chronic contamination with low levels of uranium induces subtle but significant levels. Indeed, an internal contamination of rats for several weeks leads to detection of uranium in many cerebral structures, in association with an alteration of short-term memory and an increase of anxiety level. Biological effects of uranium on the metabolisms of xenobiotics, steroid hormones and vitamin D were described in the liver, testis and kidneys. These recent scientific data suggest that uranium could participate to increase of health risks linked to environmental pollution. (authors)

Purification of uranium metal

International Nuclear Information System (INIS)

Suzuki, Kenji; Shikama, Tatsuo; Ochiai, Akira.

1993-01-01

We developed the system for purifying uranium metal and its metallic compounds and for growing highly pure uranium compounds to study their intrinsic physical properties. Uranium metal was zone refined under low contamination conditions as far as possible. The degree of the purity of uranium metal was examined by the conventional electrical resistivity measurement and by the chemical analysis using the inductive coupled plasma emission spectrometry (ICP). The results show that some metallic impurities evaporated by the r.f. heating and other usual metallic impurities moved to the end of a rod with a molten zone. Therefore, we conclude that the zone refining technique is much effective to the removal of metallic impurities and we obtained high purified uranium metal of 99.99% up with regarding to metallic impurities. The maximum residual resistivity ratio, the r.r.r., so far obtained was about 17-20. Using the purified uranium, we are attempting to grow a highly pure uranium-titanium single crystals. (author)

Carbonate heap leach of uranium-contaminated soils

International Nuclear Information System (INIS)

Turney, W.R.; Mason, C.F.V.; Longmire, P.

1994-01-01

A new approach to removal of uranium from soils based on existing heap leach mining technologies proved highly effective for remediation of soils from the Fernald Environmental Management Project (FEMP) near Cincinnati, Ohio. In laboratory tests, remediation of uranium-contaminated soils by heap leaching with carbonate salt solutions was demonstrated in column experiments. An understanding of the chemical processes that occur during carbonate leach of uranium from soils may lead to enhancement of uranium removal. Carbonate leaching requires the use of an integrated and closed circuit process, wherein the leach solutions are recycled and the reagents are reused, resulting in a minimum secondary waste stream. Carbonate salt leach solution has two important roles. Primarily, the formation of highly soluble anionic carbonate uranyl species, including uranyl dicarbonate (UO 2 CO 32 = ) and uranyl tricarbonate (UO 2 CO 33 4- ), allows for high concentration of uranium in a leachate solution. Secondly, carbonate salts are nearly selective for dissolution of uranium from uranium contaminated soils. Other advantages of the carbonate leaching process include (1) the high solubility, (2) the selectivity, (3) the purity of the solution produced, (4) the relative ease with which a uranium product can be precipitated directly from the leachate solution, and (5) the relatively non-corrosive and safe handling characteristics of carbonate solutions. Experiments conducted in the laboratory have demonstrated the effectiveness of carbonate leach. Efficiencies of uranium removal from the soils have been as high as 92 percent. Higher molar strength carbonate solutions (∼0.5M) proved more effective than lower molar strength solutions (∼ 0.1M). Uranium removal is also a function of lixiviant loading rate. Furthermore, agglomeration of the soils with cement resulted in less effective uranium removal

The distribution of depleted uranium contamination in Colonie, NY, USA

International Nuclear Information System (INIS)

Lloyd, N.S.; Chenery, S.R.N.; Parrish, R.R.

2009-01-01

Uranium oxide particles were dispersed into the environment from a factory in Colonie (NY, USA) by prevailing winds during the 1960s and '70s. Uranium concentrations and isotope ratios from bulk soil samples have been accurately measured using inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) without the need for analyte separation chemistry. The natural range of uranium concentrations in the Colonie soils has been estimated as 0.7-2.1 μg g -1 , with a weighted geometric mean of 1.05 μg g -1 ; the contaminated soil samples comprise uranium up to 500 ± 40 μg g -1 . A plot of 236 U/ 238 U against 235 U/ 238 U isotope ratios describes a mixing line between natural uranium and depleted uranium (DU) in bulk soil samples; scatter from this line can be accounted for by heterogeneity in the DU particulate. The end-member of DU compositions aggregated in these bulk samples comprises (2.05 ± 0.06) x 10 -3235 U/ 238 U, (3.2 ± 0.1) x 10 -5236 U/ 238 U, and (7.1 ± 0.3) x 10 -6234 U/ 238 U. The analytical method is sensitive to as little as 50 ng g -1 DU mixed with the natural uranium occurring in these soils. The contamination footprint has been mapped northward from site, and at least one third of the uranium in a soil sample from the surface 5 cm, collected 5.1 km NNW of the site, is DU. The distribution of contamination within the surface soil horizon follows a trend of exponential decrease with depth, which can be approximated by a simple diffusion model. Bioturbation by earthworms can account for dispersal of contaminant from the soil surface, in the form of primary uranium oxide particulates, and uranyl species that are adsorbed to organic matter. Considering this distribution, the total mass of uranium contamination emitted from the factory is estimated to be c. 4.8 tonnes.

The distribution of depleted uranium contamination in Colonie, NY, USA

Energy Technology Data Exchange (ETDEWEB)

Lloyd, N.S., E-mail: nsl3@alumni.leicester.ac.uk [Department of Geology, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); Chenery, S.R.N. [British Geological Survey, Kingsley Dunham Centre, Keyworth, Nottingham, NG12 5GG (United Kingdom); Parrish, R.R. [Department of Geology, University of Leicester, University Road, Leicester, LE1 7RH (United Kingdom); NERC Isotope Geosciences Laboratory, Kingsley Dunham Centre, Keyworth, Nottingham, NG12 5GG (United Kingdom)

2009-12-20

Uranium oxide particles were dispersed into the environment from a factory in Colonie (NY, USA) by prevailing winds during the 1960s and '70s. Uranium concentrations and isotope ratios from bulk soil samples have been accurately measured using inductively coupled plasma quadrupole mass spectrometry (ICP-QMS) without the need for analyte separation chemistry. The natural range of uranium concentrations in the Colonie soils has been estimated as 0.7-2.1 {mu}g g{sup -1}, with a weighted geometric mean of 1.05 {mu}g g{sup -1}; the contaminated soil samples comprise uranium up to 500 {+-} 40 {mu}g g{sup -1}. A plot of {sup 236}U/{sup 238}U against {sup 235}U/{sup 238}U isotope ratios describes a mixing line between natural uranium and depleted uranium (DU) in bulk soil samples; scatter from this line can be accounted for by heterogeneity in the DU particulate. The end-member of DU compositions aggregated in these bulk samples comprises (2.05 {+-} 0.06) x 10{sup -3235}U/{sup 238}U, (3.2 {+-} 0.1) x 10{sup -5236}U/{sup 238}U, and (7.1 {+-} 0.3) x 10{sup -6234}U/{sup 238}U. The analytical method is sensitive to as little as 50 ng g{sup -1} DU mixed with the natural uranium occurring in these soils. The contamination footprint has been mapped northward from site, and at least one third of the uranium in a soil sample from the surface 5 cm, collected 5.1 km NNW of the site, is DU. The distribution of contamination within the surface soil horizon follows a trend of exponential decrease with depth, which can be approximated by a simple diffusion model. Bioturbation by earthworms can account for dispersal of contaminant from the soil surface, in the form of primary uranium oxide particulates, and uranyl species that are adsorbed to organic matter. Considering this distribution, the total mass of uranium contamination emitted from the factory is estimated to be c. 4.8 tonnes.

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Bioremediation of Uranium-Contaminated Groundwater using Engineered Injection and Extraction

Science.gov (United States)

Greene, J. A.; Neupauer, R.; Ye, M.; Kasprzyk, J. R.; Mays, D. C.; Curtis, G. P.

2017-12-01

During in-situ remediation of contaminated groundwater, a treatment chemical is injected into the contaminated groundwater to react with and degrade the contaminant, with reactions occurring where the treatment chemical contacts the contaminant. Traditional in-situ groundwater remediation relies on background groundwater flow for spreading of treatment chemicals into contaminant plumes. Engineered Injection and Extraction (EIE), in which time-varying induced flow fields are used to actively spread the treatment chemical into the contaminant plume, has been developed to increase contact between the contaminant and treatment chemical, thereby enhancing contaminant degradation. EIE has been investigated for contaminants that degrade through irreversible bimolecular reaction with a treatment chemical, but has not been investigated for a contaminant governed by reversible reactions. Uranium primarily occurs in its aqueous, mobile form, U(VI), in the environment but can be bioreduced to its sparingly soluble, immobile form, U(IV), by iron reducing bacteria stimulated by an acetate amendment. In this study, we investigate the ability of EIE to facilitate and sustain favorable conditions to immobilize uranium during remediation, and to prevent re-mobilization of uranium into the aqueous phase after active remediation has ended. Simulations in this investigation are conducted using a semi-synthetic model based on physical and chemical conditions at the Naturita Uranium Mill Tailings Remedial Action (UMTRA) site in southwestern Colorado and the Old Rifle UMTRA site in western Colorado. The EIE design is optimized for the synthetic model using the Borg multi-objective evolutionary algorithm.

Persistence of uranium groundwater plumes: contrasting mechanisms at two DOE sites in the groundwater-river interaction zone.

Science.gov (United States)

Zachara, John M; Long, Philip E; Bargar, John; Davis, James A; Fox, Patricia; Fredrickson, Jim K; Freshley, Mark D; Konopka, Allan E; Liu, Chongxuan; McKinley, James P; Rockhold, Mark L; Williams, Kenneth H; Yabusaki, Steve B

2013-04-01

We examine subsurface uranium (U) plumes at two U.S. Department of Energy sites that are located near large river systems and are influenced by groundwater-river hydrologic interaction. Following surface excavation of contaminated materials, both sites were projected to naturally flush remnant uranium contamination to levels below regulatory limits (e.g., 30 μg/L or 0.126 μmol/L; U.S. EPA drinking water standard), with 10 years projected for the Hanford 300 Area (Columbia River) and 12 years for the Rifle site (Colorado River). The rate of observed uranium decrease was much lower than expected at both sites. While uncertainty remains, a comparison of current understanding suggests that the two sites have common, but also different mechanisms controlling plume persistence. At the Hanford 300 A, the persistent source is adsorbed U(VI) in the vadose zone that is released to the aquifer during spring water table excursions. The release of U(VI) from the vadose zone and its transport within the oxic, coarse-textured aquifer sediments is dominated by kinetically-limited surface complexation. Modeling implies that annual plume discharge volumes to the Columbia River are small (oxidation of naturally reduced, contaminant U(IV) in the saturated zone and a continuous influx of U(VI) from natural, up-gradient sources influence plume persistence. Rate-limited mass transfer and surface complexation also control U(VI) migration velocity in the sub-oxic Rifle groundwater. Flux of U(VI) from the vadose zone at the Rifle site may be locally important, but it is not the dominant process that sustains the plume. A wide range in microbiologic functional diversity exists at both sites. Strains of Geobacter and other metal reducing bacteria are present at low natural abundance that are capable of enzymatic U(VI) reduction in localized zones of accumulated detrital organic carbon or after organic carbon amendment. Major differences between the sites include the geochemical nature of

Natural uranium toxicology - evaluation of internal contamination in man; Toxicologie de l'uranium naturel - essai d'evaluation de la contamination interne chez l'homme

Energy Technology Data Exchange (ETDEWEB)

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

1968-07-01

After reminding the physical and chemical properties of natural uranium which might affect its toxicology, a comprehensive investigation upon natural uranium metabolism and toxicity and after applying occupational exposure standards to this particular poison, it has been determined, from accident reports and human experience reported in the related literature, a series of formulae obtained by theoretical mathematical development giving principles for internal contamination monitoring and disclosure by determining uranium in the urine of occupationally exposed individuals. An assay is performed to determine individual internal contamination according to the various contamination cases. The outlined purposes, mainly practical, required some options and extrapolations. The proposed formula allows a preliminary approach and also to determine shortly a contamination extent or to discuss the systematical urinalysis results as compared with individual radio-toxicology monitoring professional standards. (author) [French] Apres le rappel des caracteristiques physiques et des proprietes chimiques de l'uranium naturel pouvant avoir une influence sur sa toxicologie, l'etude detaillee de son metabolisme et de sa toxicite, puis l'application des normes professionnelles d'exposition au cas particulier de ce toxique, il est etabli, a partir des comptes rendus d'accidents et de l'experimentation humaine rapportes dans la litterature, une serie de formules obtenues par developpement mathematique theorique qui posent les principes de la surveillance et de la mise en evidence de la contamination interne par la recherche et le dosage de l'uranium dans les urines d'individus professionnellement exposes. Un essai d'evaluation de la contamination interne individuelle suivant les differents cas de contamination est effectue. Le formulaire propose permet de faire une premiere approximation et d'apprecier rapidement l'importance d'une contamination ou bien d'interpreter les resultats d

Micro-distribution of uranium in bone after contamination: new insight into its mechanism of accumulation into bone tissue

Energy Technology Data Exchange (ETDEWEB)

Bourgeois, Damien [ICSM, LHYS, Bagnols-sur-Ceze (France); Burt-Pichat, Brigitte [INSERM, UMR 1033 Lyon (France); Lyon Univ. (France); Le Goff, Xavier [ICSM, L2ME, Bagnols-sur-Ceze (France)

2015-09-15

After internal contamination, uranium rapidly distributes in the body; up to 20 % of the initial dose is retained in the skeleton, where it remains for years. Several studies suggest that uranium has a deleterious effect on the bone cell system, but little is known regarding the mechanisms leading to accumulation of uranium in bone tissue. We have performed synchrotron radiation-based micro-X-ray fluorescence (SR μ-XRF) studies to assess the initial distribution of uranium within cortical and trabecular bones in contaminated rats' femurs at the micrometer scale. This sensitive technique with high spatial resolution is the only method available that can be successfully applied, given the small amount of uranium in bone tissue. Uranium was found preferentially located in calcifying zones in exposed rats and rapidly accumulates in the endosteal and periosteal area of femoral metaphyses, in calcifying cartilage and in recently formed bone tissue along trabecular bone. Furthermore, specific localized areas with high accumulation of uranium were observed in regions identified as micro-vessels and on bone trabeculae. These observations are of high importance in the study of the accumulation of uranium in bone tissue, as the generally proposed passive chemical sorption on the surface of the inorganic part (apatite) of bone tissue cannot account for these results. Our study opens original perspectives in the field of exogenous metal bio-mineralization.

A melt refining method for uranium-contaminated aluminum

International Nuclear Information System (INIS)

Uda, T.; Iba, H.; Hanawa, K.

1986-01-01

Melt refining of uranium-contaminated aluminum which has been difficult to decontaminate because of the high reactivity of aluminum, was experimentally studied. Samples of contaminated aluminum and its alloys were melted after adding various halide fluxes at various melting temperatures and various melting times. Uranium concentration in the resulting ingots was determined. Effective flux compositions were mixtures of chlorides and fluorides, such as LiF, KCl, and BaCl 2 , at a fluoride/chloride mole ratio of 1 to 1.5. The removal of uranium from aluminum (the ''decontamination effect'') increased with decreasing melting temperature, but the time allowed for reaction had little influence. Pure aluminum was difficult to decontaminate from uranium; however, uranium could be removed from alloys containing magnesium. This was because the activity of the aluminum was decreased by formation of the intermetallic compound Al-Mg. With a flux of LiF-KCl-BaCl 2 and a temperature of 800 0 C, uranium added to give an initial concentration of 500 ppm was removed from a commercial alloy of aluminum, A5056, which contains 5% magnesium, to a final concentration of 0.6 ppm, which is near that in the initial aluminum alloy

Removal of uranium from uranium-contaminated soils -- Phase 1: Bench-scale testing. Uranium in Soils Integrated Demonstration

Energy Technology Data Exchange (ETDEWEB)

Francis, C. W.

1993-09-01

To address the management of uranium-contaminated soils at Fernald and other DOE sites, the DOE Office of Technology Development formed the Uranium in Soils Integrated Demonstration (USID) program. The USID has five major tasks. These include the development and demonstration of technologies that are able to (1) characterize the uranium in soil, (2) decontaminate or remove uranium from the soil, (3) treat the soil and dispose of any waste, (4) establish performance assessments, and (5) meet necessary state and federal regulations. This report deals with soil decontamination or removal of uranium from contaminated soils. The report was compiled by the USID task group that addresses soil decontamination; includes data from projects under the management of four DOE facilities [Argonne National Laboratory (ANL), Los Alamos National Laboratory (LANL), Oak Ridge National Laboratory (ORNL), and the Savannah River Plant (SRP)]; and consists of four separate reports written by staff at these facilities. The fundamental goal of the soil decontamination task group has been the selective extraction/leaching or removal of uranium from soil faster, cheaper, and safer than current conventional technologies. The objective is to selectively remove uranium from soil without seriously degrading the soil`s physicochemical characteristics or generating waste forms that are difficult to manage and/or dispose of. Emphasis in research was placed more strongly on chemical extraction techniques than physical extraction techniques.

Building Conceptual Models of Field-Scale Uranium Reactive Transport in a Dynamic Vadose Zone-Aquifer-River System

International Nuclear Information System (INIS)

Yabusaki, Steven B.; Fang, Yilin; Waichler, Scott R.

2008-01-01

Subsurface simulation is being used to build, test, and couple conceptual process models to better understand controls on a 0.4 km by 1.0 km uranium plume that has persisted above the drinking water standard in the groundwater of the Hanford 300 Area over the last 15 years. At this site, uranium-contaminated sediments in the vadose zone and aquifer are subject to significant variations in water levels and velocities driven by the diurnal, weekly, seasonal, and episodic Columbia River stage dynamics. Groundwater flow reversals typically occur twice a day with significant exchange of river water and groundwater in the near-river aquifer. Mixing of the dilute solution chemistry of the river with the groundwater complicates the uranium sorption behavior as the mobility of U(VI) has been shown experimentally to be a function of pH, carbonate, calcium, and uranium. Furthermore, uranium mass transfer between solid and aqueous phases has been observed to be rate-limited in the context of the high groundwater velocities resulting from the river stage fluctuations and the highly transmissive sediments (hydraulic conductivities ∼1500 m/d). One- and two-dimensional vertical cross-sectional simulations of variably-saturated flow and reactive transport, based on laboratory-derived models of distributed rate mass transfer and equilibrium multicomponent surface complexation, are used to assess uranium transport at the dynamic vadose zone aquifer interface as well as changes to uranium mobility due to incursions of river water into the aquifer

Bioremediation of ground water contaminants at a uranium mill tailings site

International Nuclear Information System (INIS)

Barton, L.L.; Nuttall, H.E.; Thomson, B.M.; Lutze, W.

1995-01-01

Ground water contaminated with uranium from milling operations must be remediated to reduce the migration of soluble toxic compounds. At the mill tailings site near Tuba City, Arizona (USA) the approach is to employ bioremediation for in situ immobilization of uranium by bacterial reduction of uranyl, U(VI), compounds to uraninite, U(IV). In this initial phase of remediation, details are provided to indicate the magnitude of the contamination problem and to present preliminary evidence supporting the proposition that bacterial immobilization of uranium is possible. Additionally, consideration is given to contaminating cations and anions that may be at toxic levels in ground water at this uranium mill tailing site and detoxification strategies using bacteria are addressed. A model concept is employed so that results obtained at the Tuba City site could contribute to bioremediation of ground water at other uranium mill tailings sites

Derived surface contamination limits for the uranium mining and milling industry

International Nuclear Information System (INIS)

Ching, S.H.

1984-10-01

Derived Surface Contamination Limits (DSCL) are proposed for the control of surface contamination at the work place for the uranium mining and milling industry. They have been derived by a method incorporating recent ICRP recommendations and consideration of the radiation exposure pathways of ingestion, inhalation and external irradiation of the basal layer of skin. A generalized DSCL of 10 5 Bq/m 2 of beta activity is recommended for all contaminants likely to be found in uranium mine and mill workplaces except for fresh uranium concentrates. In the latter case, the DSCL is expressed in terms of alpha activity because the ratio of beta to alpha activities for fresh uranium concentrates is variable; the beta activity increases with the ingrowth of U-238 daughter products (Th-234 and Pa-234m) until secular equilibrium is re-established in about six months. A surface contamination limit of 10 4 Bq/m 2 of beta activity is proposed for the release of non-porous materials and equipment with no detectable loose contamination to the public domain

Uranium-contaminated soils: Ultramicrotomy and electron beam analysis

International Nuclear Information System (INIS)

Buck, E.C.; Dietz, N.L.; Bates, J.K.; Cunnane, J.C.

1994-01-01

Uranium contaminated soils from the Fernald Operation Site, Ohio, have been examined by a combination of optical microscopy, scanning electron microscopy with backscattered electron detection (SEM/BSE), and analytical electron microscopy (AEM). A method is described for preparing of transmission electron microscopy (TEM) thin sections by ultramicrotomy. By using these thin sections, SEM and TEM images can be compared directly. Uranium was found in iron oxides, silicates (soddyite), phosphates (autunites), and fluorite. Little uranium was associated with clays. The distribution of uranium phases was found to be inhomogeneous at the microscopic level

Remediation of soil/concrete contaminated with uranium and radium by biological method

International Nuclear Information System (INIS)

Gye-Nam Kim; Seung-Su Kim; Hye-Min Park; Won-Suk Kim; Uk-Ryang Park; Jei-Kwon Moon

2013-01-01

Biological method was studied for remediation of soil/concrete contaminated with uranium and radium. Optimum experiment conditions for mixing ratios of penatron and soil, and the pH of soil was obtained through several bioremediations with soil contaminated with uranium and radium. It was found that an optimum mixing ratio of penatron for bioremediation of uranium soil was 1 %. Also, the optimum pH condition for bioremediation of soil contaminated with uranium and radium was 7.5. The removal efficiencies of uranium and radium from higher concentration of soil were rather reduced in comparison with those from lower concentration of soil. Meanwhile, the removal of uranium and radium in concrete by bioremediation is possible but the removal rate from concrete was slower than that from soil. The removal efficiencies of uranium and radium from soil under injection of 1 % penatron at pH 7.5 for 120 days were 81.2 and 81.6 %, respectively, and the removal efficiencies of uranium and radium from concrete under the same condition were 63.0 and 45.2 %, respectively. Beyond 30 days, removal rates of uranium and radium from soil and concrete by bioremediation was very slow. (author)

Experiment on Physical Desalinisation of Uranium-contaminated Gravel Surface

International Nuclear Information System (INIS)

Park, Uk-Ryang; Kim, Gye-Nam; Kim, Seung-Soo; Han, Gyu-Seong; Moon, Jai-Kwon

2014-01-01

As a result, the method to wash uranium-contaminated gravels could not get satisfactory desalinization rate. During the long oxidization process it was judged that uranium penetrated inside the gravels, so we tried to increase the desalinization rate by fragmentizing them into pieces and then washing them. The desalinization rate after fragmentizing the gravels into pieces and washing them brought a satisfactory result.. However, we could obtain desired concentration for gravels with high uranium concentration by fragmentizing them and breaking them further into even smaller pieces. Likewise, desalinization using soil washing process is complicated and has to go through multiple washing steps, resulting in too much of waste fluid generated accordingly. The increase of waste fluid generated leads to the increase in by-products of the final disposal process later on, bringing a not good economic result. Furthermore, taking into account that the desalinization rate is 65% during soil washing process, it is expected that gravel washing will show a similar desalinization result; it is considered uneasy to have a perfect desalinization only by soil washing. The grinding method is actually used in the primary desalinization process in order to desalinize radioactivity-contaminated concrete. This method does desalinization by grinding the radioactivity-contaminated area of the concrete surface with desalinization equipment, which enables a near-to-perfect desalinization for relatively thinly contaminated surface. Likewise, this research verified the degree of desalinization by applying the grinding method and comparing it to the fragmentizing-washing method, and attempted to find a method to desalinize uranium-contaminated gravels more effectively. In order to desalinize uranium-contaminated gravels more effectively and compare to the existing washing-desalinization method, we conducted a desalinization experiment with grinding method that grinds gravel surface. As a

Remediation of uranium contaminated soils with bicarbonate extraction and microbial U(VI) reduction

International Nuclear Information System (INIS)

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

1995-01-01

A process for concentrating uranium from contaminated soils in which the uranium is first extracted with bicarbonate and then the extracted uranium is precipitated with U(VI)-reducing microorganisms was evaluated for a variety of uranium-contaminated soils. Bicarbonate (100 mM) extracted 20-94% of the uranium that was extracted with nitric acid. The U(VI)-reducing microorganism, Desulfovibrio desulfuricans reduced the U(VI) to U(IV) in the bicarbonate extracts. In some instances unidentified dissolved extracted components, presumably organics, gave the extract a yellow color and inhibited U(VI) reduction and/or the precipitation of U(IV). Removal of the dissolved yellow material with the addition of hydrogen peroxide alleviated this inhibition. These results demonstrate that bicarbonate extraction of uranium from soil followed by microbial U(VI) reduction might be an effective mechanism for concentrating uranium from some contaminated soils. (author)

Scale-Up Information for Gas-Phase Ammonia Treatment of Uranium in the Vadose Zone at the Hanford Site Central Plateau

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Zhong, Lirong [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Thomle, Jonathan N. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Uranium is present in the vadose zone at the Hanford Central Plateau and is of concern for protection of groundwater. The Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau identified gas-phase treatment and geochemical manipulation as potentially effective treatment approaches for uranium and technetium in the Hanford Central Plateau vadose zone. Based on laboratory evaluation, use of ammonia vapor was selected as the most promising uranium treatment candidate for further development and field testing. While laboratory tests have shown that ammonia treatment effectively reduces the mobility of uranium, additional information is needed to enable deployment of this technology for remediation. Of importance for field applications are aspects of the technology associated with effective distribution of ammonia to a targeted treatment zone, understanding the fate of injected ammonia and its impact on subsurface conditions, and identifying effective monitoring approaches. In addition, information is needed to select equipment and operational parameters for a field design. As part of development efforts for the ammonia technology for remediation of vadose zone uranium contamination, field scale-up issues were identified and have been addressed through a series of laboratory and modeling efforts. This report presents a conceptual description for field application of the ammonia treatment process, engineering calculations to support treatment design, ammonia transport information, field application monitoring approaches, and a discussion of processes affecting the fate of ammonia in the subsurface. The report compiles this information from previous publications and from recent research and development activities. The intent of this report is to provide technical information about these scale-up elements to support the design and operation of a field test for the ammonia treatment technology.

Hydrogeochemical exploration for uranium in parts of Bhiwani district, Haryana, India - a preliminary study

International Nuclear Information System (INIS)

Pande, Dheeraj; Verma, A.K.; Srinivasan, S.; Bangroo, P.N.; Manjeet Kumar; Singh, Diwakar

1998-01-01

Hydrogeochemical exploration was carried out in the soil covered areas with isolated outcrops of metaquartzites of middle-Proterozoic Alwar group (Delhi supergroup) in parts of Bhiwani district of Haryana for identifying suitable locales for uranium mineralisation and also for establishing the sub-surface extensions of outcropping mineralisation. The preliminary evaluation of hydrogeochemical data indicates that the ground waters have dominantly surface water characteristics and are modified to some extent by agricultural fertilisers. Three hydrogeochemical anomalous zones, one each of uranium, uranium-vanadium and vanadium have been identified in the area. Anomalous content of uranium in the uranium zone is most likely to be due to very high sulphate content which may be a result of either heavy application of fertilisers or presence of gypsum-like horizons. The uranium-vanadium zone lies in close proximity to surface radiometric anomalies identified in the area and show little effect of agricultural contamination. The vanadium zone exhibits the least agricultural contamination and is related to ground waters of deeper origin. The uranium-vanadium and vanadium zones are found to be significant from the point of view of uranium mineralisation. The close association of uranium and vanadium in the area and the proximity of the uranium-vanadium zone to the surface radiometric anomalies suggest that the surface anomalies may have deeper extensions. (author)

Natural uranium toxicology - evaluation of internal contamination in man; Toxicologie de l'uranium naturel - essai d'evaluation de la contamination interne chez l'homme

Energy Technology Data Exchange (ETDEWEB)

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

1968-07-01

After reminding the physical and chemical properties of natural uranium which might affect its toxicology, a comprehensive investigation upon natural uranium metabolism and toxicity and after applying occupational exposure standards to this particular poison, it has been determined, from accident reports and human experience reported in the related literature, a series of formulae obtained by theoretical mathematical development giving principles for internal contamination monitoring and disclosure by determining uranium in the urine of occupationally exposed individuals. An assay is performed to determine individual internal contamination according to the various contamination cases. The outlined purposes, mainly practical, required some options and extrapolations. The proposed formula allows a preliminary approach and also to determine shortly a contamination extent or to discuss the systematical urinalysis results as compared with individual radio-toxicology monitoring professional standards. (author) [French] Apres le rappel des caracteristiques physiques et des proprietes chimiques de l'uranium naturel pouvant avoir une influence sur sa toxicologie, l'etude detaillee de son metabolisme et de sa toxicite, puis l'application des normes professionnelles d'exposition au cas particulier de ce toxique, il est etabli, a partir des comptes rendus d'accidents et de l'experimentation humaine rapportes dans la litterature, une serie de formules obtenues par developpement mathematique theorique qui posent les principes de la surveillance et de la mise en evidence de la contamination interne par la recherche et le dosage de l'uranium dans les urines d'individus professionnellement exposes. Un essai d'evaluation de la contamination interne individuelle suivant les differents cas de contamination est effectue. Le formulaire propose permet de faire une premiere approximation et d'apprecier rapidement l'importance d

Remediation of uranium contaminated soils with bicarbonate extraction and microbial U(VI) reduction

Science.gov (United States)

Philips , Elizabeth J.P.; Landa, Edward R.; Lovely, Derek R.

1995-01-01

A process for concentrating uranium from contaminated soils in which the uranium is first extracted with bicarbonate and then the extracted uranium is precipitated with U(VI)-reducing microorganisms was evaluated for a variety of uranuum-contaminated soils. Bicarbonate (100 mM) extracted 20–94% of the uranium that was extracted with nitric acid. The U(VI)-reducing microorganism,Desulfovibrio desulfuricans reduced the U(VI) to U(IV) in the bicarbonate extracts. In some instances unidentified dissolved extracted components, presumably organics, gave the extract a yellow color and inhibited U(VI) reduction and/or the precipitation of U(IV). Removal of the dissolved yellow material with the addition of hydrogen peroxide alleviated this inhibition. These results demonstrate that bicarbonate extraction of uranium from soil followed by microbial U(VI) reduction might be an effective mechanism for concentrating uranium from some contaminated soils.

Determining uranium speciation in contaminated soils by molecular spectroscopic methods: Examples from the Uranium in Soils Integrated Demonstration

International Nuclear Information System (INIS)

Allen, P.G.; Berg, J.M.; Chisholm-Brause, C.J.; Conradson, S.D.; Donohoe, R.J.; Morris, D.E.; Musgrave, J.A.; Tait, C.D.

1994-01-01

The US Department of Energy's former uranium production facility located at Fernald, OH (18 mi NW of Cincinnati) is the host site for an Integrated Demonstration for remediation of uranium-contaminated soils. A wide variety of source terms for uranium contamination have been identified reflecting the diversity of operations at the facility. Most of the uranium contamination is contained in the top ∼1/2 m of soil, but uranium has been found in perched waters indicating substantial migration. In support of the development of remediation technologies and risk assessment, we are conducting uranium speciation studies on untreated and treated soils using molecular spectroscopies. Untreated soils from five discrete sites have been analyzed. We have found that ∼80--90% of the uranium exists as hexavalent UO 2 2+ species even though many source terms consisted of tetravalent uranium species such as UO 2 . Much of the uranium exists as microcrystalline precipitates (secondary minerals). There is also clear evidence for variations in uranium species from the microscopic to the macroscopic scale. However, similarities in speciation at sites having different source terms suggest that soil and groundwater chemistry may be as important as source term in defining the uranium speciation in these soils. Characterization of treated soils has focused on materials from two sites that have undergone leaching using conventional extractants (e.g., carbonate, citrate) or novel chelators such as Tiron. Redox reagents have also been used to facilitate the leaching process. Three different classes of treated soils have been identified based on the speciation of uranium remaining in the soils. In general, the effective treatments decrease the total uranium while increasing the ratio of U(IV) to U(VI) species

Uranium-contaminated soils: Ultramicrotomy and electron beam analysis

International Nuclear Information System (INIS)

Buck, E.C.; Dietz, N.L.; Bates, J.K.; Cunnane, J.C.

1994-02-01

Uranium-contaminated soils from the U.S. Department of Energy (DOE) Fernald Site, Ohio, have been examined by a combination of scanning electron microscopy with backscattered electron imaging (SEM/BSE) and analytical electron microscopy (AEM). The inhomogeneous distribution of particulate uranium phases in the soil required the development of a method for using ultramicrotomy to prepare transmission electron microscopy (TEM) thin sections of the SEM mounts. A water-miscible resin was selected that allowed comparison between SEM and TEM images, permitting representative sampling of the soil. Uranium was found in iron oxides, silicates (soddyite), phosphates (autunites), and fluorite (UO 2 ). No uranium was detected in association with phyllosilicates in the soil

Study on remediation for uranium contaminated soils enhanced by chelator using brassica mustard

International Nuclear Information System (INIS)

Wan Qinfang; Pan Ning; Jin Yongdong; Xia Chuanqin

2012-01-01

Screening of perfect hyperaccumulators is the key to the application of this technology. Through the previous stage study, mustard was found to be good at absorption and accumulation of uranium among 51 species, the plant grows fast with wide adaptability and large biomass. Researches will focus on the following two aspects: 1. Simulating U- contaminated soils was prepared by two different ways to add uranium. (1). UO 2 (NO 3 ) 2 . 6H 2 O solution was sprayed into soil when the plant was grown in the soil; (2). Above U-contaminated soils after planting and placed for a year. Study on whether the way of adding uranium can effect mustard accumulate uranium. Results found: in the first Phytoremediation, U-contaminated concentration at 100 mg/kg, U concentration in shoots reaches 1103.42 mg/kg, roots reach 1909.49 mg/kg, annual removal rate is 7.81%; in the second Phytoremediation, U-contaminated concentration at 100 mg/kg, U concentration in shoots reach 295.83 mg/kg, roots reach 268.42 mg/kg, annual removal rate is 2.52%. Led to the difference between the twice remediation is the speciation of uranium m soils has changed, respectively, Tessier-five step continuous extraction method for determination of uranium speciation in soils and found available uranium (exchangeable uranium, uranium carbonate) in the soil of the first phytoremediation was 52% higher than the second phytoremediation. 2. Study on chelators (Citric acids, Malic acids) and soil amendments (Organic fertilizer, microbe fertilizer. Humic acid organic fertilizer, Urea) whether effect mustard accumulate uranium, found organic fertilizer can reduce shoots accumulate uranium, Citric acid and microbe fertilizer increase shoots enrichment of uranium. (authors)

Treatment of uranium contaminated wastewater – a review

International Nuclear Information System (INIS)

Dulama, M.; Iordache, M.; Deneanu, N.

2013-01-01

The paper presents a study of the treatment techniques used for uranium recovery from aqueous solutions, such as: precipitation, ion exchange processes, sorption processes, solvent extractions, separation by liquid membrane, nanofiltration and reverse osmosis. The necessary elements for rigorous treatment experiments that can be used to define innovative procedure for uranium contaminated wastewater treatment are described in this review. The published data were summarized and the areas for further research were identified in order to be able to propose an environmental friendly technology in the field of uranium production and recovery cycle. (authors)

DEEP VADOSE ZONE TREATABILITY TEST PLAN

International Nuclear Information System (INIS)

Chronister, G.B.; Truex, M.J.

2009-01-01

(sm b ullet) Treatability test plan published in 2008 (sm b ullet) Outlines technology treatability activities for evaluating application of in situ technologies and surface barriers to deep vadose zone contamination (technetium and uranium) (sm b ullet) Key elements - Desiccation testing - Testing of gas-delivered reactants for in situ treatment of uranium - Evaluating surface barrier application to deep vadose zone - Evaluating in situ grouting and soil flushing

Uranium Phases in Contaminated Sediments Below Hanford's U Tank Farm

International Nuclear Information System (INIS)

Um, Wooyong; Wang, Zheming; Serne, R. Jeffrey; Williams, Benjamin D.; Brown, Christopher F.; Dodge, Cleveland J.; Francis, Arokiasamy J.

2009-01-01

Macroscopic and spectroscopic investigations (XAFS, XRF and TRLIF) on Hanford contaminated vadose zone sediments from the U-tank farm showed that U(VI) exists as different surface phases as a function of depth below ground surface (bgs). Dominant U(VI) silicate precipitates (boltwoodite and uranophane) were present in shallow-depth sediments (15-16 m bgs). In the intermediate depth sediments (20-25 m bgs), adsorbed U(VI) phases dominated but small amounts of surface precipitates consisting of polynuclear U(VI) surface complex were also identified. The deep depth sediments (> 28 m bgs) showed no signs of contact with tank wastes containing Hanford-derived U(VI), but natural uranium solid phases were observed. Most of the U(VI) was preferentially associated with the silt and clay size fractions and showed strong correlation with Ca, especially for the precipitated U(VI) silicate phase in the shallow depth sediments. Because U(VI) silicate precipitates dominate the U(VI) phases in the shallow depth sediments, macroscopic (bi)carbonate leaching should result in U(VI) releases from both desorption and dissolution processes. Having several different U(VI) surface phases in the Hanford contaminated sediments indicates that the U(VI) release mechanism could be complicated and that detailed characterization of the sediments would be needed to estimate U(VI) fate and transport in vadose zone

Process of quantity determination of uranium by chromatography in liquid zone

International Nuclear Information System (INIS)

Muller, J.P.; Cojean, J.; Daubizit, M.

1993-01-01

The invention concerns a process of quantity determination of uranium by chromatography in liquid zone, usable to determine the quantity of uranium traces. Solutions to be treated can be aqueous or organic

Biodegradation of uranium-contaminated waste oil

International Nuclear Information System (INIS)

Hary, L.F.

1983-01-01

The Portsmouth Gaseous Diffusion Plant routinely generates quantities of uranium-contaminated waste oil. The current generation rate of waste oil is approximately 2000 gallons per year. The waste is presently biodegraded by landfarming on open field soil plots. However, due to the environmental concerns associated with this treatment process, studies were conducted to determine the optimum biodegradation conditions required for the destruction of this waste. Tests using respirometric flasks were conducted to determine the biodegradation rate for various types of Portsmouth waste oil. These tests were performed at three different loading rates, and on unfertilized and fertilized soil. Additional studies were conducted to evaluate the effectiveness of open field landfarming versus treatment at a greenhouse-like enclosure for the purpose of maintaining soil temperatures above ambient conditions. The respirometric tests concluded that the optimum waste oil loading rate is 10% weight of oil-carbon/weight of soil (30,600 gallons of uranium-contaminated waste oil/acre) on soils with adjusted carbon:nitrogen and carbon:phosphorus ratios of 60:1 and 800:1, respectively. Also, calculational results indicated that greenhouse technology does not provide a significant increase in biodegradation efficiency. Based on these study results, a 6300 ft. 2 abandoned anaerobic digester sludge drying bed is being modified into a permanent waste oil biodegradation facility. The advantage of using this area is that uranium contamination will be contained by the bed's existing leachate collection system. This modified facility will be capable of handling approximately 4500 gallons of waste oil per year; accordingly current waste generation quantities will be satisfactorily treated. 15 refs., 14 figs., 4 tabs

Study on growth of highly pure uranium compounds

International Nuclear Information System (INIS)

Shikama, Tatsuo; Ochiai, Akira; Suzuki, Kenji.

1992-01-01

We developed the systems for growing highly pure uranium compounds to study their intrinsic physical properties. Uranium metal was zone refined under low contamination conditions as far as possible. Chemical analysis of the purified uranium was performed using the inductive coupled plasma emission spectrometry (ICP). The problem that emission spectra of the uranium conceal those of analyzed impurities was settled by extraction of the uranium using tri-n-butyl-phosphate (TBP). The result shows that some metallic impurities such as Pb, Mn, Cu etc. evaporated by the r.f. heating and other usual metallic impurities moved to the end of rod with molten zone. Therefore, we conclude that the zone refining technique is much effective to the removal of metallic impurities and we obtained highly purified uranium metal of 99.99 % up with regard to metallic impurities. Using the purified uranium, we attempted to grow a highly pure uranium-titanium single crystals. (author)

300 Area Treatability Test: Laboratory Development of Polyphosphate Remediation Technology for In Situ Treatment of Uranium Contamination in the Vadose Zone and Capillary Fringe

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Pierce, Eric M.; Bacon, Diana H.; Oostrom, Martinus; Gunderson, Katie M.; Webb, Samuel M.; Bovaird, Chase C.; Cordova, Elsa A.; Clayton, Eric T.; Parker, Kent E.; Ermi, Ruby M.; Baum, Steven R.; Vermeul, Vincent R.; Fruchter, Jonathan S.

2008-09-30

This report presents results from bench-scale treatability studies conducted under site-specific conditions to optimize the polyphosphate amendment for implementation of a field-scale technology demonstration to stabilize uranium within the 300 Area vadose and smear zones of the Hanford Site. The general treatability testing approach consisted of conducting studies with site sediment and under site conditions, to develop an effective chemical formulation and infiltration approach for the polyphosphate amendment under site conditions. Laboratory-scale dynamic column tests were used to 1) quantify the retardation of polyphosphate and its degradation products as a function of water content, 2) determine the rate of polyphosphate degradation under unsaturated conditions, 3) develop an understanding of the mechanism of autunite formation via the reaction of solid phase calcite-bound uranium and aqueous polyphosphate remediation technology, 4) develop an understanding of the transformation mechanism, the identity of secondary phases, and the kinetics of the reaction between uranyl-carbonate and -silicate minerals with the polyphosphate remedy under solubility-limiting conditions, and 5) quantify the extent and rate of uranium released and immobilized based on the infiltration rate of the polyphosphate remedy and the effect of and periodic wet-dry cycling on the efficacy of polyphosphate remediation for uranium in the vadose zone and smear zone.

Uranium Bio-accumulation and Cycling as revealed by Uranium Isotopes in Naturally Reduced Sediments from the Upper Colorado River Basin

Science.gov (United States)

Lefebvre, Pierre; Noël, Vincent; Jemison, Noah; Weaver, Karrie; Bargar, John; Maher, Kate

2016-04-01

Uranium (U) groundwater contamination following oxidized U(VI) releases from weathering of mine tailings is a major concern at numerous sites across the Upper Colorado River Basin (CRB), USA. Uranium(IV)-bearing solids accumulated within naturally reduced zones (NRZs) characterized by elevated organic carbon and iron sulfide compounds. Subsequent re-oxidation of U(IV)solid to U(VI)aqueous then controls the release to groundwater and surface water, resulting in plume persistence and raising public health concerns. Thus, understanding the extent of uranium oxidation and reduction within NRZs is critical for assessing the persistence of the groundwater contamination. In this study, we measured solid-phase uranium isotope fractionation (δ238/235U) of sedimentary core samples from four study sites (Shiprock, NM, Grand Junction, Rifle and Naturita, CO) using a multi-collector inductively coupled plasma mass spectrometer (MC-ICP-MS). We observe a strong correlation between U accumulation and the extent of isotopic fractionation, with Δ238U up to +1.8 ‰ between uranium-enriched and low concentration zones. The enrichment in the heavy isotopes within the NRZs appears to be especially important in the vadose zone, which is subject to variations in water table depth. According to previous studies, this isotopic signature is consistent with biotic reduction processes associated with metal-reducing bacteria. Positive correlations between the amount of iron sulfides and the accumulation of reduced uranium underline the importance of sulfate-reducing conditions for U(IV) retention. Furthermore, the positive fractionation associated with U reduction observed across all sites despite some variations in magnitude due to site characteristics, shows a regional trend across the Colorado River Basin. The maximum extent of 238U enrichment observed in the NRZ proximal to the water table further suggests that the redox cycling of uranium, with net release of U(VI) to the groundwater by

Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

Energy Technology Data Exchange (ETDEWEB)

1993-12-01

This Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells. This risk assessment evaluates the most contaminated monitor wells at the processing site. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.

Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

International Nuclear Information System (INIS)

1993-12-01

This Baseline Risk Assessment of Groundwater Contamination at the Uranium Mill Tailings Site Near Gunnison, Colorado evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells. This risk assessment evaluates the most contaminated monitor wells at the processing site. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium

Use of Gas Transported Reactants for Uranium Remediation in Vadose Zone Sediments

International Nuclear Information System (INIS)

Szecsody, James E.; Zhong, Lirong; Truex, Michael J.; Resch, Charles T.; Williams, Mark D.

2010-01-01

This laboratory-scale investigation is focused on decreasing mobility of uranium in subsurface contaminated sediments in the vadose zone by in situ geochemical manipulation at low water content. This geochemical manipulation of the sediment surface phases included reduction, pH change (acidic and alkaline), and additions of chemicals (phosphate, ferric iron) to form specific precipitates. Reactants were advected into 1-D columns packed with Hanford 200 area U-contaminated sediment as a reactive gas (for CO2, NH3, H2S, SO2), with a 0.1% water content mist (for NaOH, Fe(III), HCl, PO4) and with a 1% water content foam (for PO4). Because uranium is present in the sediment in multiple phases, changes in U surface phases were evaluated with a series of liquid extractions that dissolve progressively less soluble phases and electron microbe identification of mineral phases. In terms of the short-term decrease in U mobility (in decreasing order), NH3, NaOH mist, CO2, HCl mist, and Fe(III) mist showed 20% to 35% change in U surface phases. The two reductive gas treatments (H2S and SO2) showed little change. For long-term decrease in U transport, mineral phases created that had low solubility (phosphates, silicates) were desired, so NH3, phosphates (mist and foam delivered), and NaOH mist showed the greatest formation of these minerals.

Advanced remediation of uranium-contaminated soil.

Science.gov (United States)

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

2016-11-01

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

Uranium accumulation in valentinite within the oxidation zone of an antimony occurrence

International Nuclear Information System (INIS)

Sergeev, I.P.; Kurilo, M.V.

1985-01-01

As a result of mineralogic-radiogeochemical study of real composition of oxidation zone of antimony occurrence represented by quartz - antimonite vien in silicificated sandstones the previousy undescribed phenomenon of uranium concentration in valentinite Sb 2 O 3 one of antimonite oxidation products has been found. According to the data of fission radiography the enrichment of valentinite with uranium is clearly seen, particularly of its concentrically zonal aggregates. The valentinite is the basic uranium mineral-concentrator in the oxidation zone, whereas in the initial mineral - antimonite as well as in the product of its more complete oxidation - stibiconite - uranium is lacking. Probably the crystallochemical properties of anhydrous antimony oxide (valentinite) by analogy with those for iron (goethite hematite) and titanium (leucoxene) are the most favourable for uranium adsorption as compared with high-water antimony oxides (stibiconite) or iron (limonite), which do not usually sorb uranium

Uranium accumulation in valentinite within the oxidation zone of an antimony occurrence

Energy Technology Data Exchange (ETDEWEB)

Sergeev, I.P.; Kurilo, M.V.

1985-01-01

As a result of mineralogic-radiogeochemical study of real composition of oxidation zone of antimony occurrence represented by quartz - antimonite vien in silicificated sandstones the previousy undescribed phenomenon of uranium concentration in valentinite Sb/sub 2/O/sub 3/ one of antimonite oxidation products has been found. According to the data of fission radiography the enrichment of valentinite with uranium is clearly seen, particularly of its concentrically zonal aggregates. The valentinite is the basic uranium mineral-concentrator in the oxidation zone, whereas in the initial mineral - antimonite as well as in the product of its more complete oxidation - stibiconite - uranium is lacking. Probably the crystallochemical properties of anhydrous antimony oxide (valentinite) by analogy with those for iron (goethite hematite) and titanium (leucoxene) are the most favourable for uranium adsorption as compared with high-water antimony oxides (stibiconite) or iron (limonite), which do not usually sorb uranium.

Research on structure-alteration zone related to uranium mineralization and its exploration significance

International Nuclear Information System (INIS)

Huang Xianfang; Liu Dechang; Ye Fawang; Dong Xiuzhen; Yang Xu Zhang Hongguang

2008-01-01

The paper is focused on recommending geological characteristics of structure-alteration zone which is found from image interpretation in Bashibulake District, north of Tarim Basin, expounding remote sensing information enhancement and extraction technique, analyzing image feature, genetic mechanism and discussing the relationship between uranium mineralization and structure-alteration zone. A new discovery is raised through applying remote sensing information analysis and geologic analysis, that is, the uranium deposits in Bashibulake District are controlled by structure-alteration zone. The new understanding provides a new view point for reconsidering main controlling factors and uranium mineralization distribution in the area. It is helpful for further reconnaissance and exploration in the area. (authors)

Evaluation of residual uranium contamination in the dirt floor of an abandoned metal rolling mill.

Science.gov (United States)

Glassford, Eric; Spitz, Henry; Lobaugh, Megan; Spitler, Grant; Succop, Paul; Rice, Carol

2013-02-01

A single, large, bulk sample of uranium-contaminated material from the dirt floor of an abandoned metal rolling mill was separated into different types and sizes of aliquots to simulate samples that would be collected during site remediation. The facility rolled approximately 11,000 tons of hot-forged ingots of uranium metal approximately 60 y ago, and it has not been used since that time. Thirty small mass (≈ 0.7 g) and 15 large mass (≈ 70 g) samples were prepared from the heterogeneously contaminated bulk material to determine how measurements of the uranium contamination vary with sample size. Aliquots of bulk material were also resuspended in an exposure chamber to produce six samples of respirable particles that were obtained using a cascade impactor. Samples of removable surface contamination were collected by wiping 100 cm of the interior surfaces of the exposure chamber with 47-mm-diameter fiber filters. Uranium contamination in each of the samples was measured directly using high-resolution gamma ray spectrometry. As expected, results for isotopic uranium (i.e., U and U) measured with the large-mass and small-mass samples are significantly different (p 0.05) from results for the large- or small-mass samples. Large-mass samples are more reliable for characterizing heterogeneously distributed radiological contamination than small-mass samples since they exhibit the least variation compared to the mean. Thus, samples should be sufficiently large in mass to insure that the results are truly representative of the heterogeneously distributed uranium contamination present at the facility. Monitoring exposure of workers and the public as a result of uranium contamination resuspended during site remediation should be evaluated using samples of sufficient size and type to accommodate the heterogeneous distribution of uranium in the bulk material.

Remediation of uranium contaminated water and soil by PIMS approach

International Nuclear Information System (INIS)

Raicevic, S.; Raicevic, J.; Smiciklas, I. . E-mail address of corresponding author: raich@beotel.yu; Raicevic, S.)

2005-01-01

Contamination of soil by uranium (U) represents a permanent threat for food and water resources. For this reason, remediation is a very important measure for protection of the health of the population living in the vicinity of these contaminated sites. Phosphate- Induced Metal Stabilization (PIMS) represents one of the powerful methods for remediation of soil and water contaminated by U, including depleted uranium (DU). By this approach it is possible to stabilize metals in the form of phosphate phases and other low soluble phases that are stable over geological time. PIMS is based on application of a special form of apatite of biological origin, Apatite II, to clean up metal and radionuclide contamination, in situ or ex situ. This biogenic apatite can be emplaced as a down-gradient permeable reactive barrier, mixed into contaminated soil or waste or used as a disposal liner. Here we will briefly describe the PIMS remediation protocol. (author)

Gold, uranium and thorium in zones of greenschist displacement metamorphism

International Nuclear Information System (INIS)

Gavrilenko, B.V.; Savitskij, A.V.; Titov, V.V.

1987-01-01

Distribution of gold, uranium (bar and mobile) and thorium in 15 zones of greenschist dislocated metamorphism in different structures of the Karelo-Kola region carried out by geologic formations of the Early-Archean-Late-Proterozoic age has been studied. More than 200 samples of well core from 0-200 m depths have been analyzed. The results obtained testify to the increase of gold, uranium and less thorium content in zones of green-schist dislocated metamorphism in comparison with the enclosing rocks 1.4-3.1 times. The variation coefficient of gold, uranium and thorium content in green-schist dislocated tectonites increases 1.5-2.9 times. The correlation coefficient of Au/U mob. pair is +0.69, and Au/U bar pair -+0.87. Essential correlation between concentrations of all three elements in enclosing rocks is absent

Composition and Distribution of Tramp Uranium Contamination on BWR and PWR Fuel Rods

International Nuclear Information System (INIS)

Schienbein, Marcel; Zeh, Peter; Hurtado, Antonio; Rosskamp, Matthias; Mailand, Irene; Bolz, Michael

2012-09-01

In a joint research project of VGB and AREVA NP GmbH the behaviour of alpha nuclides in nuclear power plants with light water reactors has been investigated. Understanding the source and the behaviour of alpha nuclides is of big importance for planning radiation protection measures for outages and upcoming dismantling projects. Previous publications have shown the correlation between plant specific alpha contamination of the core and the so called 'tramp fuel' or 'tramp uranium' level which is linked to the defect history of fuel assemblies and accordingly the amount of previously washed out fuel from defective fuel rods. The methodology of tramp fuel estimation is based on fission product concentrations in reactor coolant but also needs a good knowledge of tramp fuel composition and in-core distribution on the outer surface of fuel rods itself. Sampling campaigns of CRUD deposits of irradiated fuel assemblies in different NPPs were performed. CRUD analyses including nuclide specific alpha analysis have shown systematic differences between BWR and PWR plants. Those data combined with literature results of fuel pellet investigations led to model improvements showing that a main part of fission products is caused by fission of Pu-239 an activation product of U-238. CRUD investigations also gave a better picture of the in-core composition and distribution of the tramp uranium contamination. It was shown that the tramp uranium distribution in PWR plants is time dependent. Even new fuel assemblies will be notably contaminated after only one cycle of operation. For PWR applies the following logic: the higher the local power the higher the contamination. With increasing burnup the local rod power usually decreases leading to decreasing tramp uranium contamination on the fuel rod surface. This is not applicable for tramp uranium contamination in BWR. CRUD contamination (including the tramp fuel deposits) is much more fixed and is constantly increasing

Experimental Plan: 300 Area Treatability Test: In Situ Treatment of the Vadose Zone and Smear Zone Uranium Contamination by Polyphosphate Infiltration

International Nuclear Information System (INIS)

Wellman, Dawn M.; Pierce, Eric M.; Oostrom, Mart; Fruchter, Jonathan S.

2007-01-01

The overall objectives of the treatability test is to evaluate and optimize polyphosphate remediation technology for infiltration either from ground surface, or some depth of excavation, providing direct stabilization of uranium within the deep vadose and capillary fringe above the 300 Area aquifer. Expected result from this experimental plan is a data package that includes: (1) quantification of the retardation of polyphosphate, (2) the rate of degradation and the retardation of degradation products as a function of water content, (3) an understanding of the mechanism of autunite formation via the reaction of solid phase calcite-bound uranium and aqueous polyphosphate remediation technology, (4) an understanding of the transformation mechanism, identity of secondary phases, and the kinetics of the reaction between uranyl-carbonate and silicate minerals with the polyphosphate remedy under solubility-limiting conditions, (5) quantification of the extent and rate of uranium released and immobilized based on the infiltration rate of the polyphosphate remedy and the effect of and periodic wet-dry cycling on the efficacy of polyphosphate remediation for uranium in the vadose zone and capillary fringe, and (6) quantification of reliable equilibrium solubility values for autunite under hydraulically unsaturated conditions allowing accurate prediction of the long-term stability of autunite. Moreover, results of intermediate scale testing will quantify the transport of polyphosphate and degradation products, and yield degradation rates, at a scale that is bridging the gap between the small-scale UFA studies and the field scale. These results will be used to test and verify a site-specific, variable saturation, reactive transport model and to aid in the design of a pilot-scale field test of this technology. In particular, the infiltration approach and monitoring strategy of the pilot test would be primarily based on results from intermediate-scale testing. Results from this

Effect of Co-Contaminants Uranium and Nitrate on Iodine Remediation

Energy Technology Data Exchange (ETDEWEB)

Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lee, Brady D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Lawter, Amanda R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Resch, Charles T. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Baum, Steven R. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Leavy, Ian I. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Freedman, Vicky L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2017-09-01

The objective of this study is to evaluate the significance of co-contaminants on the migration and transformation of iodine species in the Hanford subsurface environment. These impacts are relevant because remedies that target individual contaminants like iodine, may not only impact the fate and transport of other contaminants in the subsurface, but also inhibit the effectiveness of a targeted remedy. For example, iodine (as iodate) co-precipitates with calcite, and has been identified as a potential remedy because it immobilizes iodine. Since uranium also co-precipitates with calcite in field sediments, the presence of uranium may also inhibit iodine co-precipitation. Another potentially significant impact from co-existing contaminants is iodine and nitrate. The presence of nitrate has been shown to promote biogeochemical reduction of iodate to iodide, thereby increasing iodine species subsurface mobility (as iodide exhibits less sorption). Hence, this study reports on both laboratory batch and column experiments that investigated a) the change in iodate uptake mass and rate of uptake into precipitating calcite due to the presence of differing amounts of uranium, b) the amount of change of the iodate bio-reduction rate due to the presence of differing nitrate concentrations, and c) whether nitrite can reduce iodate in the presence of microbes and/or minerals acting as catalysts.

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

Interfacial Reduction-Oxidation Mechanisms Governing Fate and Transport of Contaminants in the Vadose Zone

Energy Technology Data Exchange (ETDEWEB)

Principal Investigator: Baolin Deng, University of Missouri, Columbia, MO; Co-Principal Investigator: Silvia Sabine Jurisson, University of Missouri, Columbia, MO; Co-Principal Investigator: Edward C. Thornton, Pacific Northwest National Laboratory Richland, WA; Co-Principal Investigator: Jeff Terry, Illinois Institute of Technology, Chicago, IL

2008-05-12

There are many soil contamination sites at the Department of Energy (DOE) installations that contain radionuclides and toxic metals such as uranium (U), technetium (Tc), and chromium (Cr). Since these contaminants are the main 'risk drivers' at the Hanford site (WA) and some of them also pose significant risk at other DOE facilities (e.g., Oak Ridge Reservation - TN; Rocky Flats - CO), development of technologies for cost effective site remediation is needed. Current assessment indicates that complete removal of these contaminants for ex-situ disposal is infeasible, thus in-situ stabilization through reduction to insoluble species is considered one of the most important approaches for site remediation. In Situ Gaseous Reduction (ISGR) is a technology developed by Pacific Northwest National Laboratory (PNNL) for vadose zone soil remediation. The ISGR approach uses hydrogen sulfide (H{sub 2}S) for reductive immobilization of contaminants that show substantially lower mobility in their reduced forms (e.g., Tc, U, and Cr). The technology can be applied in two ways: (i) to immobilize or stabilize pre-existing contaminants in the vadose zone soils by direct H{sub 2}S treatment, or (ii) to create a permeable reactive barrier (PRB) that prevents the migration of contaminants. Direct treatment involves reduction of the contaminants by H{sub 2}S to less mobile species. Formation of a PRB is accomplished through reduction of ferric iron species in the vadose zone soils by H{sub 2}S to iron sulfides (e.g., FeS), which provides a means for capturing the contaminants entering the treated zone. Potential future releases may occur during tank closure activities. Thus, the placement of a permeable reactive barrier by ISGR treatment can be part of the leak mitigation program. Deployment of these ISGR approaches, however, requires a better understanding of the immobilization kinetics and mechanisms, and a better assessment of the long-term effectiveness of treatment. The

The use of carbonate lixiviants to remove uranium from uranium-contaminated soils

International Nuclear Information System (INIS)

Francis, C.W.; Lee, S.Y.; Wilson, J.H.; Timpson, M.E.; Elless, M.P.

1997-01-01

The objective of this research was to design an extraction media and procedure that would selectively remove uranium without adversely affecting the soils' physicochemical characteristics or generating secondary waste forms difficult to manage or dispose of. Investigations centered around determining the best lixivant and how the various factors such as pH, time, and temperature influenced extraction efficiency. Other factors investigated included the influence of attrition scrubbing, the effect of oxidants and reductants and the recycling of lixiviants. Experimental data obtained at the bench- and pilot-scale levels indicated 80 to 95% of the uranium could be removed from the uranium-contaminated soils by using a carbonate lixiviant. The best treatment was three successive extractions with 0.25 M carbonate-bicarbonate (in presence of KMnO 4 as an oxidant) at 40 C followed with two water rinses

The relationship of carbonate-siliceous-pelitic uranium deposits with the plunging portions of down-faulted zones

International Nuclear Information System (INIS)

Liu Guihua; Liu Shouzhi; Zhou Huawen.

1985-01-01

Five uranium deposits of carbonate-siliceous-pelitic type occurred in different geological setting are studied. The geological data suggest that this type of uranium deposits is mostly located in the plunging portions of down-faulted zones. The cause of this kind of occurrence is tentatively discussed. It is proposed that uraniferous strata are the uranium source in deposits. The infiltration under arid climatic conditions promoted the uranium concentration up to ore grade. The mesozoic-cenozoic era which is characterized by the arid climate was the main ore-forming period. The converging condition of ground water in the plunging portions of down-faulted zones was better. Therefore, the plunging portions of down-faulted zones were more favourable for uranium ore formation compared with that of the uplifting portions. The preservation is the most important ore-controlling factor under the neotectonic movement and the plunging portions are the most favourable in this sence. The recognition criteria for the plunging portions of down-faulted zones which can be used in uranium exploration are proposed

Melt refining of uranium contaminated copper, nickel, and mild steel

International Nuclear Information System (INIS)

Ren Xinwen; Liu Wencang; Zhang Yuan

1993-01-01

This paper presents the experiment results on melt refining of uranium contaminated metallic discards such as copper, nickel, and mild steel. Based on recommended processes, uranium contents in ingots shall decrease below 1 ppm; metal recovery is higher than 96%; and slag production is below 5% in weight of the metal to be refined. The uranium in the slag is homogeneously distributed. The slag seems to be hard ceramics, insoluble in water, and can be directly disposed of after proper packaging

Physicochemical and mineralogical characterization of uranium-contaminated soils from the Fernald Integrated Demonstration Site

International Nuclear Information System (INIS)

Elless, M.P.; Lee, S.Y.; Timpson, M.E.

1994-01-01

An integrated approach that utilizes various characterization technologies has been developed for the Uranium Soil Integrated Demonstration program. The Fernald Environmental Restoration Management Corporation site near Cincinnati, Ohio, was selected as the host facility for this demonstration. Characterization of background, untreated contaminated, and treated contaminated soils was performed to assess the contamination and the effect of treatment efforts to remove uranium from these soils. Carbonate minerals were present in the contaminated soils (added for erosion control) but were absent in the nearby background soils. Because of the importance of the carbonate anion to uranium solubility, the occurrence of carbonate minerals in these soils will be an important factor in the development of a successful remediation technology. Uranium partitioning data among several particle-size fractions indicate that conventional soil washing will be ineffective for remediation of these soils and that chemical extraction will be necessary to lower the uranium concentration to the target level (52 mg/kg). Carbonate-based (sodium carbonate/bicarbonate) and acid-based (sulfuric and citric acids) lixiviants were employed for the selective removal of uranium from these soils. Characterization results have identified uranium phosphate minerals as the predominant uranium mineral form in both the untreated and treated soils. The low solubility associated with phosphate minerals is primarily responsible for their occurrence in the posttreated soils. Artificial weathering of the treated soils caused by the treatments, particularly acid-based lixiviants, was documented by their detrimental effects on several physicochemical characteristics of these soils (e.g., soil pH, particle-size distribution, and mineralogy)

Examination of health status of population from Uranium contaminated regions

International Nuclear Information System (INIS)

Milacic, S.; Jovicic, D.; Pantelic, G.; Kovacevic, R.; Pavlovic, M.; Tanaskovic, I.

2002-01-01

Uranium is widely distributed in the natural environment: in the soil, air and food. And thus all people on the planet inhale or ingest small quantities of uranium every day. However, depleted uranium (DU) is industrial product. It is used in medicine, aviation, astronomy, oil exploitation, as well as for military purposes for penetrating ammunition. America is not the only country that applies depleted uranium ammunition. It is a part of the military arsenal in France, England, Turkey, Israel, Russia, Saudi Arabia, Pakistan and Thailand. Depleted uranium is toxic for both humans and animals for two basic reasons: as a heavy metal, it has toxic chemical effects, and as an alpha-emitter, it also has radioactive effects. Although it is considered less radioactive than natural uranium, its toxicity is high due to high LET (linear energetic transfer) irradiation, tissue deposition (bones, kidneys, blood, lungs) and elimination time (5000 days). Radiation limit above which adverse health effects are initiated (radiation carcinogenic risk), depends on the quantity and contamination time (how much and how long), including also other factors, such as age, sex, previous health status, exposure to other materials, genetic predisposition and radiosensitivity (lack of indicators), diet and stress. According to ICRP recommendations, carcinogenic risk for the occupationally exposed individuals is minimal if the exposure is limited to the effective dose of 100 mSv for five years and not above 50 in a single year, being five times lower for general population. In average annual effective dose per population, from all sources is below 1mSv, carcinogenic risk will range from 1 per 10 000 to 1 per 100 000, and in occupationally exposed individuals exposed to maximum permitted doses (MPD), the risk of cancer with fatal outcome is below 3 per 100 000). Immediate effects of population exposure to low uranium doses do not result in evident clinical picture. Late consequences include

Flotation separation of uranium from contaminated soils

International Nuclear Information System (INIS)

Misra, M.; Mehta, R.; Garcia, H.; Chai, C.D.; Smith, R.W.

1995-01-01

The volume of low-level contaminated soil at the Department of Energy's Nuclear Weapon Sites are in the order of several million tons. Most of the contaminants are uranium, plutonium, other heavy metals and organic compounds. Selected physical separation processes have shown demonstrated potential in concentrating the radionuclides in a small fraction of the soil. Depending upon the size, nature of bonding and distributions of radionuclides, more than 90% of the radionuclide activity can be concentrated in a small volume of fraction of the soil. The physico-chemical separation processes such as flotation in a mechanical and microbubble tall column cell have shown promising applications in cleaning up the high volume contaminated soil

Selective leaching of uranium from uranium-contaminated soils: Progress report 1

International Nuclear Information System (INIS)

Francis, C.W.; Mattus, A.J.; Farr, L.L.; Elless, M.P.; Lee, S.Y.

1993-02-01

Three soils and a sediment contaminated with uranium were used to determine the effectiveness of sodium carbonate and citric acid leaching to decontaminated or remove uranium to acceptable regulatory levels. Two of the soils were surface soils from the DOE facility formerly called the Feed Materials Production Center (FMPC) at Fernald, Ohio. This facility is presently called the Femald Environmental Management Project (FEMP). Carbonate extractions generally removed from 70 to 90% of the uranium from the Fernald storage pad soil. Uranium was slightly more difficult to extract from the Fernald incinerator and the Y-12 landfarm soils. Very small amounts of uranium could be extracted from the storm sewer sediment. Extraction with carbonate at high solution-to-soil ratios were as effective as extractions at low solution-to-soil ratios, indicating attrition by the paddle mixer was not significantly different than that provided in a rotary extractor. Also, pretreatments such as milling or pulverizing the soil sample did not appear to increase extraction efficiency when carbonate extractions were carried out at elevated temperatures (60 degree C) or long extraction times (23 h). Adding KMnO 4 in the carbonate extraction appeared to increase extraction efficiency from the Fernald incinerator soil but not the Fernald storage pad soil. The most effective leaching rates (> 90 % from both Fernald soils) were obtained using a citrate/dithionite extraction procedure designed to remove amorphous (noncrystalline) iron/aluminum sesquioxides from surfaces of clay minerals. Citric acid also proved to be a very good extractant for uranium

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

Uranium Leaching from Contaminated Soil Utilizing Rhamnolipid, EDTA, and Citric Acid

Directory of Open Access Journals (Sweden)

Sara Asselin

2014-01-01

Full Text Available Biosurfactants have recently gained attention as “green” agents that can be used to enhance the remediation of heavy metals and some organic matter in contaminated soils. The overall objective of this paper was to investigate rhamnolipid, a microbial produced biosurfactant, and its ability to leach uranium present in contaminated soil from an abandoned mine site. Soil samples were collected from two locations in northern Arizona: Cameron (site of open pit mining and Leupp (control—no mining. The approach taken was to first determine the total uranium content in each soil using a hydrofluoric acid digestion, then comparing the amount of metal removed by rhamnolipid to other chelating agents EDTA and citric acid, and finally determining the amount of soluble metal in the soil matrix using a sequential extraction. Results suggested a complex system for metal removal from soil utilizing rhamnolipid. It was determined that rhamnolipid at a concentration of 150 μM was as effective as EDTA but not as effective as citric acid for the removal of soluble uranium. However, the rhamnolipid was only slightly better at removing uranium from the mining soil compared to a purified water control. Overall, this study demonstrated that rhamnolipid ability to remove uranium from contaminated soil is comparable to EDTA and to a lesser extent citric acid, but, for the soils investigated, it is not significantly better than a simple water wash.

Obtention of uranium-molybdenum alloy ingots technique to avoid carbon contamination

Energy Technology Data Exchange (ETDEWEB)

Pedrosa, Tercio A.; Paula, Joao Bosco de; Reis, Sergio C.; Brina, Jose Giovanni M.; Faeda, Kelly Cristina M.; Ferraz, Wilmar B., E-mail: tap@cdtn.b, E-mail: jbp@cdtn.b, E-mail: jgmb@cdtn.b, E-mail: ferrazw@cdtn.b [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

2011-07-01

The replacement of high enriched uranium (U{sup 235} > 85 wt%) by low enriched uranium (U{sup 235} < 20wt%) nuclear fuels in research and test reactors is being implemented as an initiative of the Reduced Enrichment for Research and Test Reactors (RERTR) program, conceived in the USA since mid-70s, in order to avoid nuclear weapons proliferation. Such replacement implies in the use of compounds or alloys with higher uranium densities. Among the several uranium alloys investigated since then, U-Mo presents great application potential due to its physical properties and good behavior during irradiation, which makes it an important option as a nuclear fuel material for the Brazilian Multipurpose Reactor - RMB. The development of the plate-type nuclear fuel based on U-Mo alloy is being performed at the Nuclear Technology Development Centre (CDTN) and also at IPEN. The carbon contamination of the alloy is one of the great concerns during the melting process. It was observed that U-Mo alloy is more critical considering carbon contamination when using graphite crucibles. Alternative melting technique was implemented at CDTN in order to avoid carbon contamination from graphite crucible using Yttria stabilized ZrO{sub 2} crucibles. Ingots with low carbon content and good internal quality were obtained. (author)

Geology, geochemistry, and geophysics of the Fry Canyon uranium/copper project site, southeastern Utah - Indications of contaminant migration

Science.gov (United States)

Otton, James K.; Zielinski, Robert A.; Horton, Robert J.

2010-01-01

The Fry Canyon uranium/copper project site in San Juan County, southeastern Utah, was affected by the historical (1957-68) processing of uranium and copper-uranium ores. Relict uranium tailings and related ponds, and a large copper heap-leach pile at the site represent point sources of uranium and copper to local soils, surface water, and groundwater. This study was designed to establish the nature, extent, and pathways of contaminant dispersion. The methods used in this study are applicable at other sites of uranium mining, milling, or processing. The uranium tailings and associated ponds sit on a bench that is as much as 4.25 meters above the level of the adjacent modern channel of Fry Creek. The copper heap leach pile sits on bedrock just south of this bench. Contaminated groundwater from the ponds and other nearby sites moves downvalley and enters the modern alluvium of adjacent Fry Creek, its surface water, and also a broader, deeper paleochannel that underlies the modern creek channel and adjacent benches and stream terraces. The northern extent of contaminated groundwater is uncertain from geochemical data beyond an area of monitoring wells about 300 meters north of the site. Contaminated surface water extends to the State highway bridge. Some uranium-contaminated groundwater may also enter underlying bedrock of the Permian Cedar Mesa Sandstone along fracture zones. Four dc-resistivity surveys perpendicular to the valley trend were run across the channel and its adjacent stream terraces north of the heap-leach pile and ponds. Two surveys were done in a small field of monitoring wells and two in areas untested by borings to the north of the well field. Bedrock intercepts, salt distribution, and lithologic information from the wells and surface observations in the well field aided interpretation of the geophysical profiles there and allowed interpretation of the two profiles not tested by wells. The geophysical data for the two profiles to the north of the

Effect of Particle-size Distribution on Chemical Washing Experiment of Uranium Contaminated Concrete

International Nuclear Information System (INIS)

Kim, Wan Suk; Kim, Gye Nam; Shon, Dong Bin; Park, Hye Min; Kim, Ki Hong; Lee, Kun Woo; Lee, Ki Won; Moon, Jei Kwon

2011-01-01

Taken down of nuclear institution was radioactive contaminated concrete over 70% of whole waste. Advanced countries have realized the importance of waste processing. Nuclear institutions keep a lot of radioactive contaminated concrete in internal waste storage. Therefore radioactive contaminated concrete disport to whole waste and reduce for self-processing standard concentration may be disposed of inexpensive more than radioactive waste storage. This study uses mechanical and thermal technology for a uranium contaminated concrete process in Korea Atomic Energy Research Institute's radioactive waste storage. Mechanical and thermal technologies are divided based on particle size. Each particles-sized concrete analyzed for uranium contamination using an MCA instrument. A chemical washing experiment was carried out

Environmental fate of depleted uranium at three sites contaminated during the balkan conflict

International Nuclear Information System (INIS)

Radenkovic, M.; Joksic, J.; Todorovic, D.; Kovacevic, M.

2006-01-01

A study on depleted uranium fate in the sites contaminated during the 1999 war conflict in Serbia was conducted in phases until the clean up activities were completed. The ammunition remains found at the locations in the surface soil were collected in the first phase during the radiation survey of the affected areas. The most of depleted uranium penetrators left buried deep into the ground exposed to the weathering and corrosion processes. The contamination level in the air, water, soil and bio -indicators was controlled all the time by routine gamma and alpha spectrometry measurements. Depleted uranium migration was studied through the soil profile surrounding the penetrator during the 2001 at the Bratoselce location showing the contamination level fall to the 1% of its value at approximately 15 cm distance to the source. The samples taken from the soil layers at different distances in the profile are subjected to a modified Tessiers five-step sequential extraction procedure. The uranium and heavy metals contents were determined in the obtained fractions. Results have specified carbonates and iron hydrous-oxides as the most probable substrates for uranium physical/chemical associations formed in the soil for the time elapsed. A very strong dependence of substrate onto contamination level was found. The correlation of uranium and other heavy metals was obtained. The 234 U/ 238 U and 235 U/ 238 U ratios are determined in extracts by alpha spectrometry after appropriate radiochemical separation procedure and thin alpha sources electroplating. The analysis has shown the share of depleted in total uranium content in exchangeable, carbonate, hydrous or crystalline iron/manganese, organic and residue phases indicating the bioavailability of depleted uranium present in the soil. The results are discussed related to detailed geochemical analysis of the particular soil type common for this region. Depleted uranium content in soil samples taken at the locations after the

Uranium Contamination in the Subsurface Beneath the 300 Area, Hanford Site, Washington

Energy Technology Data Exchange (ETDEWEB)

Peterson, Robert E.; Rockhold, Mark L.; Serne, R. Jeffrey; Thorne, Paul D.; Williams, Mark D.

2008-02-29

This report provides a description of uranium contamination in the subsurface at the Hanford Site's 300 Area. The principal focus is a persistence plume in groundwater, which has not attenuated as predicted by earlier remedial investigations. Included in the report are chapters on current conditions, hydrogeologic framework, groundwater flow modeling, and geochemical considerations. The report is intended to describe what is known or inferred about the uranium contamination for the purpose of making remedial action decisions.

Geophysical anomalies associated with uranium mineralization from Beldih mine, South Purulia Shear Zone, India

International Nuclear Information System (INIS)

Mandal, Animesh; Biswas, Arkoprovo; Mittal, Saurabh; Mohanty, William K.; Sharma, Shashi Prakash; Sengupta, Debashish; Sen, Joydip; Bhatt, A.K.

2013-01-01

Beldih mine at the central part of the South Purulia Shear Zone (SPSZ) has been reported with low grade uranium-bearing formation within quartz-magnetite-apatite host in kaolinized formation. Therefore, the present integrated geophysical study with gravity, magnetic, radiometric, very low frequency electromagnetic (VLF) and gradient resistivity profiling methods around the known mineralized zones aimed at identifying the exact geophysical signatures and lateral extent of these uranium mineralization bands. The closely spaced gravity-magnetic contours over the low to high anomaly transition zones of Bouguer, reduced-to-pole magnetic, and trend surface separated residual gravity-magnetic anomaly maps indicate the possibility of high altered zone(s) along NW-SE direction at the central part of the study area. High current density plots of VLF method and the low resistive zones in gradient resistivity study depict the coincidence with low gravity, moderately high magnetic and low resistivity anomalies at the same locations. Moderate high radioactive zones have also been observed over these locations. This also suggests the existence of radioactive mineralization over this region. Along profile P2, drilled borehole data revealed the presence of uranium mineralization at a depth of ∼100 m. The vertical projection of this mineralization band also identified as low gravity, low resistivity and high magnetic anomaly zone. Thus, the application of integrated geophysical techniques supported by geological information successfully recognized the nature of geophysical signatures associated with the uranium mineralization of this region. This enhances the scope of further integrated geophysical investigations in the unexplored regions of SPSZ. (author)

Characterization of Uranium Contamination, Transport, and Remediation at Rocky Flats - Across Remediation into Post-Closure

Science.gov (United States)

Janecky, D. R.; Boylan, J.; Murrell, M. T.

2009-12-01

The Rocky Flats Site is a former nuclear weapons production facility approximately 16 miles northwest of Denver, Colorado. Built in 1952 and operated by the Atomic Energy Commission and then Department of Energy, the Site was remediated and closed in 2005, and is currently undergoing long-term surveillance and monitoring by the DOE Office of Legacy Management. Areas of contamination resulted from roughly fifty years of operation. Of greatest interest, surface soils were contaminated with plutonium, americium, and uranium; groundwater was contaminated with chlorinated solvents, uranium, and nitrates; and surface waters, as recipients of runoff and shallow groundwater discharge, have been contaminated by transport from both regimes. A region of economic mineralization that has been referred to as the Colorado Mineral Belt is nearby, and the Schwartzwalder uranium mine is approximately five miles upgradient of the Site. Background uranium concentrations are therefore elevated in many areas. Weapons-related activities included work with enriched and depleted uranium, contributing anthropogenic content to the environment. Using high-resolution isotopic analyses, Site-related contamination can be distinguished from natural uranium in water samples. This has been instrumental in defining remedy components, and long-term monitoring and surveillance strategies. Rocky Flats hydrology interlinks surface waters and shallow groundwater (which is very limited in volume and vertical and horizontal extent). Surface water transport pathways include several streams, constructed ponds, and facility surfaces. Shallow groundwater has no demonstrated connection to deep aquifers, and includes natural preferential pathways resulting primarily from porosity in the Rocky Flats alluvium, weathered bedrock, and discontinuous sandstones. In addition, building footings, drains, trenches, and remedial systems provide pathways for transport at the site. Removal of impermeable surfaces (buildings

Cola soft drinks for evaluating the bioaccessibility of uranium in contaminated mine soils.

Science.gov (United States)

Lottermoser, Bernd G; Schnug, Ewald; Haneklaus, Silvia

2011-08-15

There is a rising need for scientifically sound and quantitative as well as simple, rapid, cheap and readily available soil testing procedures. The purpose of this study was to explore selected soft drinks (Coca-Cola Classic®, Diet Coke®, Coke Zero®) as indicators of bioaccessible uranium and other trace elements (As, Ce, Cu, La, Mn, Ni, Pb, Th, Y, Zn) in contaminated soils of the Mary Kathleen uranium mine site, Australia. Data of single extraction tests using Coca-Cola Classic®, Diet Coke® and Coke Zero® demonstrate that extractable arsenic, copper, lanthanum, manganese, nickel, yttrium and zinc concentrations correlate significantly with DTPA- and CaCl₂-extractable metals. Moreover, the correlation between DTPA-extractable uranium and that extracted using Coca-Cola Classic® is close to unity (+0.98), with reduced correlations for Diet Coke® (+0.66) and Coke Zero® (+0.55). Also, Coca-Cola Classic® extracts uranium concentrations near identical to DTPA, whereas distinctly higher uranium fractions were extracted using Diet Coke® and Coke Zero®. Results of this study demonstrate that the use of Coca-Cola Classic® in single extraction tests provided an excellent indication of bioaccessible uranium in the analysed soils and of uranium uptake into leaves and stems of the Sodom apple (Calotropis procera). Moreover, the unconventional reagent is superior in terms of availability, costs, preparation and disposal compared to traditional chemicals. Contaminated site assessments and rehabilitation of uranium mine sites require a solid understanding of the chemical speciation of environmentally significant elements for estimating their translocation in soils and plant uptake. Therefore, Cola soft drinks have potential applications in single extraction tests of uranium contaminated soils and may be used for environmental impact assessments of uranium mine sites, nuclear fuel processing plants and waste storage and disposal facilities. Copyright © 2011 Elsevier

Brittle-ductile gliding shear zone and its dynamic metallization in uranium deposit No. 3110

International Nuclear Information System (INIS)

Fang Shiyi.

1990-01-01

A preliminary study on the macroscopic geological structure, microstructures of plastic deformation rotary strain, structural geochemistry and zoning regularity of a brittle-ductile gliding shear zone in uranium deposit No. 3110 is made. Structural dynamic metallization of uranium caused by the strong shearing stress is discussed. It is pointed out that great attention must be paid to in further exploration

Baccharis Salicifolia development in the presence of high concentrations of uranium in the arid environment of San Marcos, Chihuahua

Energy Technology Data Exchange (ETDEWEB)

Luna P, M. Y.; Alarcon H, M. T.; Silva S, M.; Renteria V, M; Rodriguez V, M. A.; Herrera P, E.; Reyes C, M.; Montero C, M. E., E-mail: elena.montero@cimav.edu.m [Centro de Investigacion en Materiales Avanzados, S. C., Miguel de Cervantes 120, Complejo Industrial Chihuahua, 31109 Chihuahua (Mexico)

2011-02-15

In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. The results indicate a tendency for the plant to accumulate the uranium in its different parts, and to trans locate it to its stem and leaves. The plant is resistant to high concentrations of uranium, not showing any specific changes in relation to non contaminated areas that might indicate the presence of the contaminant. Therefore, its use as a bio monitor species is limited. (Author)

Baccharis Salicifolia development in the presence of high concentrations of uranium in the arid environment of San Marcos, Chihuahua

International Nuclear Information System (INIS)

Luna P, M. Y.; Alarcon H, M. T.; Silva S, M.; Renteria V, M; Rodriguez V, M. A.; Herrera P, E.; Reyes C, M.; Montero C, M. E.

2011-01-01

In humid zones and marine environments the bio indicator contaminants by trace elements are well established. However, in arid zones it is more difficult to find these tools because there is less biodiversity. The objective of this paper was to analyze the behavior of the Baccharis salicifolia plant in areas with high uranium concentration in arid zones, to determine the characteristics of tolerance and possible use as a bio monitor for the presence of such contaminants. For this project a uraniferous zone was selected in San Marcos, located northwest of the City of Chihuahua. A total of 8 sampling points of the plant and soil were located here. Each sample was divided into the root and the stem and leaves to determine the specific activity of the uranium in both parts of the plant and its sediments. The determination of the specific activities of the total uranium in the samples was obtained by liquid scintillation with alpha-beta separation. The results indicate a tendency for the plant to accumulate the uranium in its different parts, and to trans locate it to its stem and leaves. The plant is resistant to high concentrations of uranium, not showing any specific changes in relation to non contaminated areas that might indicate the presence of the contaminant. Therefore, its use as a bio monitor species is limited. (Author)

Radiological contamination by depleted uranium in the Al-Tahreer tower building

International Nuclear Information System (INIS)

Al-Ataby, N.R.; Aisa, B.H.; Jebir, H.M.; Hatem, J.N.

2011-01-01

The research plan included assessment of the radioactivity of the Al-Tahreer Tower Building (the Turkish restaurant recent) through direct measurements and sampling of soil for the four floors (1th,2th,3th,4th) of the building, which contains fourteen floor in addition to the basement, by using portable radiation detection equipment to know the increasing in the levels of exposure and contamination resulting from the bombing a Al-Tahreer Tower building by depleted uranium bullets, the results of radiological surveys by using the portable contamination radiation detection (CAB) indicated readings of contaminated soil reached to 60 c/sec, and parts of shells of depleted uranium reached to 90 c/ sec , while the natural contamination rate in the area is (0.5 c/sec), the natural exposure rate in the area is 9 μR/ hr but the higher exposure rate reached to 60 μR / hr when the device (Ludlum) putting on the contaminated regions(distance about 0.5 cm). The radiological analyses of the collected soil samples were done in the laboratory of the center of Radiological Researches in the Ministry of sciences and Technology by using gamma spectrometry (which contains High-purity Germanium Detector) with a efficiency of 40% and resolution 2 keV for Energy, 1.33 Mev,collection,preparations and tests of soil samples were all done according to IAEA.The normal concentration for Th 234 and Pa 234 m in the soil samples taken from areas near to the building (can consider as background radiation region) is in range 41 Bq /Kg for Th 234 ,and nil for pa 234 m ,while higher concentration of Th 234 in contaminated soil is 1194 Bq/kg,and 1664 Bq/kg for pa 234 m which is a clear indication of the presence of high concentrations an isotope of uranium 238 as they are supposed to be in equilibrium radiation. The major aim of this study include removal the contaminated regions in the building, to protect the population and the environment from the effect of radiological contamination which

Melting-decontamination method for radioactive contaminated metals

International Nuclear Information System (INIS)

Uda, Tatsuhiko; Tsuchiya, Hiroyuki; Miura, Noboru; Iba, Hajime.

1985-01-01

Purpose: To eliminate uranium components remaining in metals even after the uranium-contaminated metals are melted. Method: Metal wastes contaminated with actinide element or its compound as nuclear fuel substance are melted in a crucible. Molten metals are fallen through a filter disposed at the bottom of the crucible into another receiving crucible. Uranium compounds are still left in the molten metal fallen in the receiving crucible. The residual uranium compounds are concentrated by utilizing the principle of the zone-refining process. That is, a displaceable local-heating heater is disposed to the receiving crucible, by which metals once solidified in the receiving crucible is again heated locally to transfer from solid to molten phase in a quasi-equibilized manner. In this way, by eliminating the end of the metal rod at which the uranium is segregated, the contaminating coefficient can be improved. (Ikeda, J.)

Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado

International Nuclear Information System (INIS)

1994-04-01

This report evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells to determine the potential for immediate human health and environmental impacts. This risk assessment evaluates the most contaminated groundwater that flows beneath the processing site towards the Gunnison River. The monitor wells that have consistently shown the highest concentration of most contaminants are used in this risk assessment. This risk assessment will be used in conjunction with additional activities and documents to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium

Uranium migration in a podzol. The role of colloids in the non-saturated zone and the phreatic water: application to the Landes de Gascogne area

International Nuclear Information System (INIS)

Crancon, P.

2001-01-01

The non-saturated zone of a soil represents the interface between the atmosphere and the phreatic water. The confinement efficiency of the non-saturated zone above the phreatic water depends on the fastness of water transfers and on the type of pollutant transport mechanisms. Uranium (VI) can combine with humid acids to form very stable complexes. The aggregates of the absorbing complex are highly sensible to the variations of the ionic force of the environment. This sensitiveness can be at the origin of a strong remobilization of the colloid humic compounds of the soil, and of their migration towards the underground water. In this situation, the uranium complexed by humic compounds can rapidly migrate in the soil. The comparative reactive transport of the total uranium and its isotopes has been studied in a site, the Landes de Gascogne podzol (SW France), where metallic uranium has been sprinkled on the surface of the soil. The field study has been completed with an experimental column transport study using uranium isotopes tracer techniques. The field study shows that most of uranium is trapped in the very first cm of the soil. However, anomalous high uranium concentrations are observed in underground waters, more than 2 km away from the contaminated areas. This demonstrates that a fast and long distance transport process exists for uranium in the unsaturated zone. In the sandy soil of the study area, natural argillo-humic colloids migrate with the velocity of water but can be delayed when the ionic force of the underground waters increases. It is shown that uranium is strongly linked with the thin grain size fraction ( 233 U allows to discriminate between the uranium transported through the sand in a non-reactive way, and the uranium desorbed from the argillo-humic aggregates and the sand grain coatings. A fast reduction of the ionic force of the environment during the tests shows an important remobilization of uranium from the soil. When the complex relations

Vadose zone characterisation at industrial contaminated sites

OpenAIRE

Fernandez de Vera, Natalia; Dahan, Ofer; Dassargues, Alain; Vanclooster, Marnik; Nguyen, Frédéric; Brouyère, Serge

2015-01-01

In order to improve risk characterization and remediation measures for soil and groundwater contamination, there is a need to improve in situ vadose zone characterization. However, most available technologies have been developed in the context of agricultural soils. Such methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. To overcome such difficulties, a vadose zone experiment has been setup at a former industrial site in ...

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 migration in a podzol. The role of colloids in the non-saturated zone and the phreatic water: application to the Landes de Gascogne area; Migration de l'uranium dans un podzol. Le role des colloides dans la zone non saturee et la nappe: application aux Landes de Gascogne

Energy Technology Data Exchange (ETDEWEB)

Crancon, P

2001-01-01

The non-saturated zone of a soil represents the interface between the atmosphere and the phreatic water. The confinement efficiency of the non-saturated zone above the phreatic water depends on the fastness of water transfers and on the type of pollutant transport mechanisms. Uranium (VI) can combine with humid acids to form very stable complexes. The aggregates of the absorbing complex are highly sensible to the variations of the ionic force of the environment. This sensitiveness can be at the origin of a strong remobilization of the colloid humic compounds of the soil, and of their migration towards the underground water. In this situation, the uranium complexed by humic compounds can rapidly migrate in the soil. The comparative reactive transport of the total uranium and its isotopes has been studied in a site, the Landes de Gascogne podzol (SW France), where metallic uranium has been sprinkled on the surface of the soil. The field study has been completed with an experimental column transport study using uranium isotopes tracer techniques. The field study shows that most of uranium is trapped in the very first cm of the soil. However, anomalous high uranium concentrations are observed in underground waters, more than 2 km away from the contaminated areas. This demonstrates that a fast and long distance transport process exists for uranium in the unsaturated zone. In the sandy soil of the study area, natural argillo-humic colloids migrate with the velocity of water but can be delayed when the ionic force of the underground waters increases. It is shown that uranium is strongly linked with the thin grain size fraction (< 8 {mu}m) of the sand, and more particularly with the argillo-humic composite colloids. In the stable geochemical conditions of the experimental columns, more than 70% of uranium is trapped in the first 2 cm of the sand, even after the circulation of 100 volumes of water inside the column. This shows the strong trapping capacity of the Landes sand

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

International Nuclear Information System (INIS)

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

1995-01-01

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

Contaminant transport, revegetation, and trace element studies at inactive uranium mill tailings piles

International Nuclear Information System (INIS)

Dreesen, D.R.; Marple, M.L.; Kelley, N.E.

1978-01-01

The stabilization of inactive uranium mill tailings piles is presently under study. These studies have included investigations of stabilizing tailings by attempting to establish native vegetation without applying irrigation. Examination of processes which transport tailings or associated contaminants into the environment has been undertaken to better understand the containment provided by various stabilization methods. The uptake of toxic trace elements and radionuclides by vegetation has been examined as a mechanism of contaminant transport. The source terms of 222 Rn from inactive piles have been determined as well as the attenuation of radon flux provided by shallow soil covers. The possibility of shallow ground water contamination around an inactive pile has been examined to determine the significance of ground water transport as a mode of contaminant migration. The rationale in support of trace element studies related to uranium milling activities is presented including the enrichment, migration, and toxicities of trace elements often associated with uranium deposits. Some concepts for the stabilization of inactive piles are presented to extrapolate from research findings to practical applications. 25 references, 8 tables

Detection of uranium extraction zone by axial temperature profiles in a pulsed column for Purex process

International Nuclear Information System (INIS)

Tsukada, T.; Takahashi, K.

1991-01-01

A new method was presented for detecting uranium extraction zone in a pulsed column by means of measuring axial temperature profile originated from reaction heat during uranium extraction. Key parameters of the temperature profiles were estimated with a code developed for calculating temperature profiles in a direct-contact heat exchanger such as a pulsed column, and were verified using data from a small pulsed column simulating reaction heat with injecting hot water. Finally, the results were compared with those from an actual uranium extraction tests, indicating that the method presented was promising for detecting uranium extraction zone in a pulsed column. (author)

Cola soft drinks for evaluating the bioaccessibility of uranium in contaminated mine soils

International Nuclear Information System (INIS)

Lottermoser, Bernd G.; Schnug, Ewald; Haneklaus, Silvia

2011-01-01

There is a rising need for scientifically sound and quantitative as well as simple, rapid, cheap and readily available soil testing procedures. The purpose of this study was to explore selected soft drinks (Coca-Cola Classic (registered) , Diet Coke (registered) , Coke Zero (registered) ) as indicators of bioaccessible uranium and other trace elements (As, Ce, Cu, La, Mn, Ni, Pb, Th, Y, Zn) in contaminated soils of the Mary Kathleen uranium mine site, Australia. Data of single extraction tests using Coca-Cola Classic (registered) , Diet Coke (registered) and Coke Zero (registered) demonstrate that extractable arsenic, copper, lanthanum, manganese, nickel, yttrium and zinc concentrations correlate significantly with DTPA- and CaCl 2 -extractable metals. Moreover, the correlation between DTPA-extractable uranium and that extracted using Coca-Cola Classic (registered) is close to unity (+ 0.98), with reduced correlations for Diet Coke (registered) (+ 0.66) and Coke Zero (registered) (+ 0.55). Also, Coca-Cola Classic (registered) extracts uranium concentrations near identical to DTPA, whereas distinctly higher uranium fractions were extracted using Diet Coke (registered) and Coke Zero (registered) . Results of this study demonstrate that the use of Coca-Cola Classic (registered) in single extraction tests provided an excellent indication of bioaccessible uranium in the analysed soils and of uranium uptake into leaves and stems of the Sodom apple (Calotropis procera). Moreover, the unconventional reagent is superior in terms of availability, costs, preparation and disposal compared to traditional chemicals. Contaminated site assessments and rehabilitation of uranium mine sites require a solid understanding of the chemical speciation of environmentally significant elements for estimating their translocation in soils and plant uptake. Therefore, Cola soft drinks have potential applications in single extraction tests of uranium contaminated soils and may be used for

Cola soft drinks for evaluating the bioaccessibility of uranium in contaminated mine soils

Energy Technology Data Exchange (ETDEWEB)

Lottermoser, Bernd G., E-mail: Bernd.Lottermoser@utas.edu.au [School of Earth Sciences, University of Tasmania, Private Bag 79, Hobart, Tasmania 7001 (Australia); Schnug, Ewald; Haneklaus, Silvia [Institute for Crop and Soil Science, Federal Institute for Cultivated Plants, Julius Kuehn-Institute (JKI), Bundesallee 50, D-38116 Braunschweig (Germany)

2011-08-15

There is a rising need for scientifically sound and quantitative as well as simple, rapid, cheap and readily available soil testing procedures. The purpose of this study was to explore selected soft drinks (Coca-Cola Classic (registered) , Diet Coke (registered) , Coke Zero (registered) ) as indicators of bioaccessible uranium and other trace elements (As, Ce, Cu, La, Mn, Ni, Pb, Th, Y, Zn) in contaminated soils of the Mary Kathleen uranium mine site, Australia. Data of single extraction tests using Coca-Cola Classic (registered) , Diet Coke (registered) and Coke Zero (registered) demonstrate that extractable arsenic, copper, lanthanum, manganese, nickel, yttrium and zinc concentrations correlate significantly with DTPA- and CaCl{sub 2}-extractable metals. Moreover, the correlation between DTPA-extractable uranium and that extracted using Coca-Cola Classic (registered) is close to unity (+ 0.98), with reduced correlations for Diet Coke (registered) (+ 0.66) and Coke Zero (registered) (+ 0.55). Also, Coca-Cola Classic (registered) extracts uranium concentrations near identical to DTPA, whereas distinctly higher uranium fractions were extracted using Diet Coke (registered) and Coke Zero (registered) . Results of this study demonstrate that the use of Coca-Cola Classic (registered) in single extraction tests provided an excellent indication of bioaccessible uranium in the analysed soils and of uranium uptake into leaves and stems of the Sodom apple (Calotropis procera). Moreover, the unconventional reagent is superior in terms of availability, costs, preparation and disposal compared to traditional chemicals. Contaminated site assessments and rehabilitation of uranium mine sites require a solid understanding of the chemical speciation of environmentally significant elements for estimating their translocation in soils and plant uptake. Therefore, Cola soft drinks have potential applications in single extraction tests of uranium contaminated soils and may be used for

Modeling the migration of radioactive contaminants in groundwater of in situ leaching uranium mine

International Nuclear Information System (INIS)

Li Chunguang; Tai Kaixuan

2011-01-01

The radioactive contamination of groundwater from in situ leaching (ISL) of uranium mining is a widespread environmental problem. This paper analyzed the monitor results of groundwater contaminations for a in situ leaching uranium mine. A dynamic model of contaminants transport in groundwater in ISL well field was established. The processes and mechanisms of contaminant transport in groundwater were simulated numerically for a ISL well field. A small quantity of U and SO 4 2- migrate to outside of well field during ISL production stage. But the migration velocity and distance of contaminations is small, and the concentration is low. Contaminants migrate as anomalistic tooth-shape. The migration trend of U and SO 4 2- is consistent. Numerical modeling can provide an effective approach to analyse the transport mechanism, and forecast and control the migration of contaminants in groundwater in ISL well field. (authors)

Uranium migration in a podzol. The role of colloids in the non-saturated zone and the phreatic water: application to the Landes de Gascogne area; Migration de l'uranium dans un podzol. Le role des colloides dans la zone non saturee et la nappe: application aux Landes de Gascogne

Energy Technology Data Exchange (ETDEWEB)

Crancon, P

2001-01-01

The non-saturated zone of a soil represents the interface between the atmosphere and the phreatic water. The confinement efficiency of the non-saturated zone above the phreatic water depends on the fastness of water transfers and on the type of pollutant transport mechanisms. Uranium (VI) can combine with humid acids to form very stable complexes. The aggregates of the absorbing complex are highly sensible to the variations of the ionic force of the environment. This sensitiveness can be at the origin of a strong remobilization of the colloid humic compounds of the soil, and of their migration towards the underground water. In this situation, the uranium complexed by humic compounds can rapidly migrate in the soil. The comparative reactive transport of the total uranium and its isotopes has been studied in a site, the Landes de Gascogne podzol (SW France), where metallic uranium has been sprinkled on the surface of the soil. The field study has been completed with an experimental column transport study using uranium isotopes tracer techniques. The field study shows that most of uranium is trapped in the very first cm of the soil. However, anomalous high uranium concentrations are observed in underground waters, more than 2 km away from the contaminated areas. This demonstrates that a fast and long distance transport process exists for uranium in the unsaturated zone. In the sandy soil of the study area, natural argillo-humic colloids migrate with the velocity of water but can be delayed when the ionic force of the underground waters increases. It is shown that uranium is strongly linked with the thin grain size fraction (< 8 {mu}m) of the sand, and more particularly with the argillo-humic composite colloids. In the stable geochemical conditions of the experimental columns, more than 70% of uranium is trapped in the first 2 cm of the sand, even after the circulation of 100 volumes of water inside the column. This shows the strong trapping capacity of the Landes sand

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Durango, Colorado

International Nuclear Information System (INIS)

1995-02-01

This risk assessment evaluates the possibility of health and environmental risks from contaminated ground water at the uranium mill tailings site near Durango, Colorado. The former uranium processing site's contaminated soil and material were removed and placed at a disposal site located in Body Canyon, Colorado, during 1986--1991 by the US Departments of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating the nature and extent of ground water contamination at the site. This risk assessment follows an approach similar to that used by the US Environmental Protection Agency. The first step is to determine what site-related contaminants are found in ground water samples. The next step in the risk assessment is to determine how much of these contaminants people might ingest if they got their drinking water from a well on the site. In accordance with standard practice for this type of risk assessment, the highest contaminant concentrations from the most contaminated wells are used. The risk assessment then explains the possible health problems that could result from this amount of contamination

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Durango, Colorado

Energy Technology Data Exchange (ETDEWEB)

1995-02-01

This risk assessment evaluates the possibility of health and environmental risks from contaminated ground water at the uranium mill tailings site near Durango, Colorado. The former uranium processing site`s contaminated soil and material were removed and placed at a disposal site located in Body Canyon, Colorado, during 1986--1991 by the US Departments of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating the nature and extent of ground water contamination at the site. This risk assessment follows an approach similar to that used by the US Environmental Protection Agency. The first step is to determine what site-related contaminants are found in ground water samples. The next step in the risk assessment is to determine how much of these contaminants people might ingest if they got their drinking water from a well on the site. In accordance with standard practice for this type of risk assessment, the highest contaminant concentrations from the most contaminated wells are used. The risk assessment then explains the possible health problems that could result from this amount of contamination.

Reduction of radioactive waste from remediation of uranium-contaminated soil

Energy Technology Data Exchange (ETDEWEB)

Kim, Il Gook; Kim, Seung Soo; Kim, Gye Nam; Han, Gyu Seong; Choi, Jong Won [Decontamination and Decommissioning Research Division, Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2016-06-15

Great amounts of solid radioactive waste (second waste) and waste solution are generated from the remediation of uranium-contaminated soil. To reduce these, we investigated washing with a less acidic solution and recycling the waste solution after removal of the dominant elements and uranium. Increasing the pH of the washing solution from 0.5 to 1.5 would be beneficial in terms of economics. A high content of calcium in the waste solution was precipitated by adding sulfuric acid. The second waste can be significantly reduced by using sorption and desorption techniques on ampholyte resin S-950 prior to the precipitation of uranium at pH 3.0.

Reduction of radioactive waste from remediation of uranium-contaminated soil

International Nuclear Information System (INIS)

Kim, Il Gook; Kim, Seung Soo; Kim, Gye Nam; Han, Gyu Seong; Choi, Jong Won

2016-01-01

Great amounts of solid radioactive waste (second waste) and waste solution are generated from the remediation of uranium-contaminated soil. To reduce these, we investigated washing with a less acidic solution and recycling the waste solution after removal of the dominant elements and uranium. Increasing the pH of the washing solution from 0.5 to 1.5 would be beneficial in terms of economics. A high content of calcium in the waste solution was precipitated by adding sulfuric acid. The second waste can be significantly reduced by using sorption and desorption techniques on ampholyte resin S-950 prior to the precipitation of uranium at pH 3.0

Use of gamma camera for measurement of the internal contamination with depleted uranium

International Nuclear Information System (INIS)

Spaic, R.; Markovic, S.; Pavlovic, S.; Pavlovic, R.; Ajdinovic, B.; Baskot, B.; Djurovic, B.

2000-01-01

Depleted uranium from radioactive wastes is used for manufacturing bullets used in Iraq, Republic of Serbia and Yugoslavia. These bullets are extremely dense and capable of penetrating heavily armored vehicles. Their medical importance lies in the fact that the bullets contain seventy percent depleted uranium which creates aerosolized particles less than five microns in diameter, small enough to be inhaled, after spontaneous bullet burn at impact. Nuclear medicine scientists must be aware of this and be prepared to measure internal contamination of persons exposed to this radioactive material. Whole body counters (WBC) represent appropriate equipment for this purpose but their availability in developing countries is not sufficient. Gamma camera is an alternative. The minimum detectable activity (MDA) of depleted uranium, iodine and technetium for gamma cameras was measured in this paper. Low energy X-ray 100 KeV with 20% windows are used for the depleted uranium detection. About 40% gamma emissions from depleted uranium fall within these limits. The activities measured (50-100 Bq) are about ten times higher then on WBC (5 Bq). This does not limit the use of gamma cameras for measurement of lung or whole body internal contamination with depleted uranium. (author)

Baseline risk assessment of groundwater contamination at the uranium mill tailings site near Shiprock, New Mexico

International Nuclear Information System (INIS)

1993-09-01

This report evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1986 by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This risk assessment is the first document specific to this site for the Groundwater Project. This risk assessment follows the approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the floodplain groundwater are arsenic, magnesium, manganese, nitrate, sodium, sulfate, and uranium. The complete list of contaminants associated with the terrace groundwater could not be determined due to the lack of the background groundwater quality data. However, uranium, nitrate, and sulfate are evaluated since these chemicals are clearly associated with uranium processing and are highly elevated compared to regional waters. It also could not be determined if the groundwater occurring in the terrace is a usable water resource, since it appears to have originated largely from past milling operations. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if a drinking well were installed in the contaminated groundwater or if there were exposure to surface expressions of contaminated water. Potential exposures to surface water include incidental contact with contaminated water or sediments by children playing on the floodplain and consumption of meat and milk from domestic animals grazed and watered on the floodplain

Ways for forestry management in radioactive contamination zone

International Nuclear Information System (INIS)

Kaletnik, N.N.; Pasternak, P.S.; Kiselevskij, R.G.; Molotkov, P.I.; Kuchma, N.D.; Landin, V.P.; Matukhno, Yu.D.; Shlonchak, G.L.; Podkur, P.P.; Khudolej, V.I.

1989-01-01

The necessity of realization of forestry protection measures in the radioactive contamination zone is determined by the forest ecological part and the problems of elimination of the territory secondary contamination in the process of radionuclide migration. The damage of forest tracts in the zone is analyzed. The data on pine surface contamination levels, needles appearance in forests with different degree of damage and crown phytomass, growth for pines 20 years old in forests with different damage degrees are considered. The index of pine forest state is obtained. The data discussed reveal the complicated situation, which takes place in the 30-km zone forests. It is shown that the depth of radionuclide migration into soil for forest areas is twice lower as compared with that for open places. 6 tabs

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

International Nuclear Information System (INIS)

Bai Jingping

2001-01-01

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

Treatment of Uranium-Contaminated Concrete for Reducing Secondary Radioactive Waste

Energy Technology Data Exchange (ETDEWEB)

Kim, Seung Soo; Han, G. S; Park, U. K; Kim, G. N.; Moon, J. K. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2014-10-15

A volume reduction of the concrete waste by appropriate treatment technologies will decrease the amount of waste to be disposed of and result in a reduction of the disposal cost and an enhancement of the efficiency of the disposal site. Our group has developed a decontamination process for uranium-contaminated (U-contaminated) concrete, and some experiments were performed to reduce the second radioactive waste. A decontamination process was developed to remove uranium from concrete waste. The yellow or brown colored surface of the wall brick with high concentration of uranium was removed by a chisel until the radioactivity of remaining block reached less than 1 Bq/g. The concrete waste coated with epoxy was directly burned by an oil flame, and the burned surface was then removed using the same method as the treatment of the brick. The selective mechanical removal of the concrete block reduced the amount of secondary radioactive waste. The concrete blocks without an epoxy were crushed to below 30 mm and sifted to 1 mm. When the concrete pieces larger than 1 mm were sequentially washed with a clear recycle solution and 1.0 M of nitric acid, their radioactivity reached below the limit value of uranium for self-disposal. For the concrete pieces smaller than 1 mm, a rotary washing machine and electrokinetic equipment were also used.

Treatment of Uranium-Contaminated Concrete for Reducing Secondary Radioactive Waste

International Nuclear Information System (INIS)

Kim, Seung Soo; Han, G. S; Park, U. K; Kim, G. N.; Moon, J. K.

2014-01-01

A volume reduction of the concrete waste by appropriate treatment technologies will decrease the amount of waste to be disposed of and result in a reduction of the disposal cost and an enhancement of the efficiency of the disposal site. Our group has developed a decontamination process for uranium-contaminated (U-contaminated) concrete, and some experiments were performed to reduce the second radioactive waste. A decontamination process was developed to remove uranium from concrete waste. The yellow or brown colored surface of the wall brick with high concentration of uranium was removed by a chisel until the radioactivity of remaining block reached less than 1 Bq/g. The concrete waste coated with epoxy was directly burned by an oil flame, and the burned surface was then removed using the same method as the treatment of the brick. The selective mechanical removal of the concrete block reduced the amount of secondary radioactive waste. The concrete blocks without an epoxy were crushed to below 30 mm and sifted to 1 mm. When the concrete pieces larger than 1 mm were sequentially washed with a clear recycle solution and 1.0 M of nitric acid, their radioactivity reached below the limit value of uranium for self-disposal. For the concrete pieces smaller than 1 mm, a rotary washing machine and electrokinetic equipment were also used

Assessment Of Depleted Uranium Contamination In Selective IRAQI Soils

International Nuclear Information System (INIS)

Mohammed, A.A.; Hussien, A.Sh.M.; Tawfiq, N.F.

2008-01-01

The aim of this research was to measure the radiation exposure rates in three selected Locations in southren part of Iraq (two in Nassireya, and one in Amara) resulted from the existence of depleted uranium in soil and metal pieces have been taken from destroyed tank and study mathmatically the concentration of Depleted Uranium by its dispersion from soil surface by winds and rains from 2003 to 2007. The exposure rates were measured using inspector device, while depleted uranium concentration in soil samples and tank's matal pieces were detected with Solid State Nuclear Track Detectors(SSNTDs). The wind and rain effects were considered in the calculation of dispersion effect on depleted uranium concentration in soil, where the wind effect were calculated with respect to the sites nature and soil conditions, and rain effect with respect to dispersive-convective equation for radionuclide in soil. The results obtained for the exposure rates were high near the penetrated surfac, moderate and low in soil and metal pices. The Depleted Uranium concentration in soil and metal pieces have the highest value in Nassireya. The results from dispersion calculation (wind & rain) showed that the depleted uranium concentration in 2008 will be less than the danger level and in allowable contamination range

Remediation of uranium contaminated sites: clean-up activities in Serbia

International Nuclear Information System (INIS)

Raicevic, S.; Raicevic, J. . E-mail address of corresponding author: raich@beotel.yu; Raicevic, S.)

2005-01-01

One of the serious environmental problems in Serbia represent sites contaminated with depleted uranium (DU) during past war activities. According to UNEP reports and our findings there are two types of contamination: (i) localized points of high, concentrated contamination where DU penetrators enter the soil, and (ii) low level of widespread DU contamination, which indicates that during the conflict DU dust was dispersed into the environment. Remediation of these sites is an urgent need because they represent a permanent threat to the population living in this area. Here we give a brief description of approaches commonly used in remediation of DU contaminated sites, and an overview of current clean-up activities performed in Serbia. (author)

Geophysical Responses of Hydrocarbon-impacted Zones at the Various Contamination Conditions

Science.gov (United States)

Kim, C.; Ko, K.; Son, J.; Kim, J.

2008-12-01

One controlled experiment and two field surveys were conducted to investigate the geoelectrical responses of hydrocarbon-contaminated zones, so called smeared zone, on the geophysical data at the hydrocarbon- contaminated sites with various conditions. One controlled physical model experiment with GPR using fresh gasoline and two different 3-D electrical resistivity investigations at the aged sites. One field site (former military facilities for arms maintenance) was mainly contaminated with lubricating oils and the other (former gas station) was contaminated with gasoline and diesel, respectively. The results from the physical model experiment show that GPR signals were enhanced when LNAPL was present as a residual saturation in the water-saturated system due to less attenuation of the electromagnetic energy through the soil medium of the hydrocarbon-impacted zone (no biodegradation), compared to when the medium was saturated with only water (no hydrocarbon impaction). In the former gas station site, 3-D resistivity results demonstrate that the highly contaminated zones were imaged with low resistivity anomalies since the biodegradation of petroleum hydrocarbons has been undergone for many years, causing the drastic increase in the TDS at the hydrocarbon-impacted zones. Finally, 3-D resistivity data obtained from the former military maintenance site show that the hydrocarbon-contaminated zones show high resistivity anomalies since the hydrocarbons such as lubricating oils at the contaminated soils were not greatly influenced by microbial degradation and has relatively well kept their original physical properties of high electrical resistivity. The results of the study illustrated that the hydrocarbon-impacted zones under various contamination conditions yielded various geophysical responses which include (1) enhanced GPR amplitudes at the fresh LNAPL (Gasoline to middle distillates) spill sites, (2) low electrical resistivity anomalies due to biodegradation at the

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

This document evaluates potential impacts to public health and the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1989 by the US DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, UMTRA Project is evaluating ground water contamination in this risk assessment.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah

International Nuclear Information System (INIS)

1994-09-01

This document evaluates potential impacts to public health and the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1989 by the US DOE's Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, UMTRA Project is evaluating ground water contamination in this risk assessment

Feasibility studies on electrochemical recovery of uranium from solid wastes contaminated with uranium using 1-butyl-3-methylimidazorium chloride as an electrolyte

Energy Technology Data Exchange (ETDEWEB)

Ohashi, Yusuke, E-mail: ohhashi.yusuke@jaea.go.jp [Ningyo-toge Environmental Engineering center, Japan Atomic Energy Agency, 1550 Kamisaibara, Kagamino-cho, Tomata-gun, Okayama 708-0698 (Japan); Harada, Masayuki [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1-N1-34 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan); Asanuma, Noriko [Department of Nuclear Engineering, School of Engineering, Tokai University, 4-1-1 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292 (Japan); Ikeda, Yasuhisa [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology, 2-12-1-N1-34 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2015-09-15

Highlights: • The uranium component of steel wastes and spent NaF adsorbent are easily dissolved into BMICl. • The uranyl(VI) species in BMICl are reduced to U(V) irreversibly around −0.8 to −1.3 V. • The dissolved uranium species in BMICl are recovered as black deposits electrolytically. • The deposit is the mixtures of U(IV) and U(VI) compounds containing O, F, Cl, and N elements. - Abstract: In order to examine feasibility of the electrochemical deposition method for recovering uranium from the solid wastes contaminated with uranium using ionic liquid as electrolyte, we have studied the electrochemical behavior of each solution prepared by soaking the spent NaF adsorbents and the steel waste contaminated with uranium in BMICl (1-butyl-3-methyl- imidazolium chloride). The uranyl(VI) species in BMICl solutions were found to be reduced to U(V) irreversibly around −0.8 to −1.3 V vs. Ag/AgCl. The resulting U(V) species is followed by disproportionation to U(VI) and U(IV). Based on the electrochemical data, we have performed potential controlled electrolysis of each solution prepared by soaking the spent NaF adsorbents and steel wastes in BMICl at −1.5 V vs. Ag/AgCl. Black deposit was obtained, and their composition analyses suggest that the deposit is the mixtures of U(IV) and U(VI) compounds containing O, F, Cl, and N elements. From the present study, it is expected that the solid wastes contaminated with uranium can be decontaminated by treating them in BMICl and the dissolved uranium species are recovered electrolytically.

Baseline risk assessment of groundwater contamination at the Uranium Mill Tailings Site near Gunnison, Colorado. Revision 1

Energy Technology Data Exchange (ETDEWEB)

1994-04-01

This report evaluates potential impacts to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site are being placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This is the second risk assessment of groundwater contamination at this site. The first risk assessment was performed primarily to evaluate existing domestic wells to determine the potential for immediate human health and environmental impacts. This risk assessment evaluates the most contaminated groundwater that flows beneath the processing site towards the Gunnison River. The monitor wells that have consistently shown the highest concentration of most contaminants are used in this risk assessment. This risk assessment will be used in conjunction with additional activities and documents to assist in determining what remedial action is needed for contaminated groundwater at the site after the tailings are relocated. This risk assessment follows an approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the groundwater are cadmium, cobalt, iron, manganese, sulfate, uranium, and some of the products of radioactive decay of uranium.

Residual contamination and corrosion on electrochemically marked uranium

International Nuclear Information System (INIS)

Seals, R.D.; Bullock, J.S.; Bennett, R.K.

1981-01-01

Residual contamination and potential corrosion problems on uranium parts resulting from PHB-1 and PHB-1E electroetchants have been investigated using ion microprobe mass analysis (IMMA), scanning electron microscopy (SEM), and light microscopy (LM). The effectiveness of various solvent cleaning sequences and the influence of the use of an abrasive cleaner were evaluated. The marking thicknesses and chlorine distributions were determined

System-Scale Model of Aquifer, Vadose Zone, and River Interactions for the Hanford 300 Area - Application to Uranium Reactive Transport

Energy Technology Data Exchange (ETDEWEB)

Rockhold, Mark L.; Bacon, Diana H.; Freedman, Vicky L.; Parker, Kyle R.; Waichler, Scott R.; Williams, Mark D.

2013-10-01

This report represents a synthesis and integration of basic and applied research into a system-scale model of the Hanford 300 Area groundwater uranium plume, supported by the U.S. Department of Energy’s Richland Operations (DOE-RL) office. The report integrates research findings and data from DOE Office of Science (DOE-SC), Office of Environmental Management (DOE-EM), and DOE-RL projects, and from the site remediation and closure contractor, Washington Closure Hanford, LLC (WCH). The three-dimensional, system-scale model addresses water flow and reactive transport of uranium for the coupled vadose zone, unconfined aquifer, and Columbia River shoreline of the Hanford 300 Area. The system-scale model of the 300 Area was developed to be a decision-support tool to evaluate processes of the total system affecting the groundwater uranium plume. The model can also be used to address “what if” questions regarding different remediation endpoints, and to assist in design and evaluation of field remediation efforts. For example, the proposed cleanup plan for the Hanford 300 Area includes removal, treatment, and disposal of contaminated sediments from known waste sites, enhanced attenuation of uranium hot spots in the vadose and periodically rewetted zone, and continued monitoring of groundwater with institutional controls. Illustrative simulations of polyphosphate infiltration were performed to demonstrate the ability of the system-scale model to address these types of questions. The use of this model in conjunction with continued field monitoring is expected to provide a rigorous basis for developing operational strategies for field remediation and for defining defensible remediation endpoints.

Advances in treatment methods for uranium contaminated soil and water

International Nuclear Information System (INIS)

Navratil, J.D.

2002-01-01

Water and soil contaminated with actinides, such as uranium and plutonium, are an environmental concern at most U.S. Department of Energy sites, as well as other locations in the world. Remediation actions are on going at many sites, and plans for cleanup are underway at other locations. This paper will review work underway at Clemson University in the area of treatment and remediation of soil and water contaminated with actinide elements. (author)

Baseline risk assessment of groundwater contamination at the uranium mill tailings site near Shiprock, New Mexico. Draft

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

This report evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1986 by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating groundwater contamination. This risk assessment is the first document specific to this site for the Groundwater Project. This risk assessment follows the approach outlined by the US Environmental Protection Agency (EPA). The first step is to evaluate groundwater data collected from monitor wells at the site. Evaluation of these data showed that the main contaminants in the floodplain groundwater are arsenic, magnesium, manganese, nitrate, sodium, sulfate, and uranium. The complete list of contaminants associated with the terrace groundwater could not be determined due to the lack of the background groundwater quality data. However, uranium, nitrate, and sulfate are evaluated since these chemicals are clearly associated with uranium processing and are highly elevated compared to regional waters. It also could not be determined if the groundwater occurring in the terrace is a usable water resource, since it appears to have originated largely from past milling operations. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if a drinking well were installed in the contaminated groundwater or if there were exposure to surface expressions of contaminated water. Potential exposures to surface water include incidental contact with contaminated water or sediments by children playing on the floodplain and consumption of meat and milk from domestic animals grazed and watered on the floodplain.

Understanding Fluid and Contaminant Movement in the Unsaturated Zone Using the INEEL Vadose Zone Monitoring System

International Nuclear Information System (INIS)

Hubbell, J. M.; Mattson, E. D.; Sisson, J. B.; Magnuson, S. O.

2002-01-01

DOE has hundreds of contaminated facilities and waste sites requiring cleanup and/or long-term monitoring. These contaminated sites reside in unsaturated soils (i.e. the vadose zone) above the water table. Some of these sites will require active remediation activities or removal while other sites will be placed under institutional controls. In either case, evaluating the effectiveness of the remediation strategy or institutional controls will require monitoring. Classical monitoring strategies implemented at RCRA/CERCLA sites require ground water sampling for 30 years following closure. The overall effectiveness of ground water sampling is diminished due to the fact that by the time you detect chemical transport from a waste site, a major contamination plume likely exists in the vadose zone and the aquifer. This paper suggests a more effective monitoring strategy through monitoring near the contaminant sites within the vadose zone. Vadose zone monitoring allows for quicker detection of potential contaminant transport. The INEEL Vadose Zone Monitoring System (VZMS) is becoming an accepted, cost effective monitoring technology for assessing contaminant transport at DOE facilities. This paper describes the technologies employed in the VZMS and describes how it was used at several DOE facilities. The INEEL VZMS has provided the information in developing and validating both conceptual and risk assessment models of contaminant transport at the Idaho National Engineering and Environmental Laboratory (INEEL), Oak Ridge National Laboratory (ORNL), Savannah River Site (SRS) and the Hanford site. These DOE sites exhibit a broad range of meteorologic, hydrologic and geologic conditions representative of various common geologic environments. The VZMS is comprised of advanced tensiometers, water content sensors, temperature sensors and soil and gas samplers. These instruments are placed at multiple depths in boreholes and allows for the detection of water movement in the

Estimating contaminant discharge rates from stabilized uranium tailings embankments

International Nuclear Information System (INIS)

Weber, M.F.

1986-01-01

Estimates of contaminant discharge rates from stabilized uranium tailings embankments are essential in evaluating long-term impacts of tailings disposal on groundwater resources. Contaminant discharge rates are a function of water flux through tailings covers, the mass and distribution of tailings, and the concentrations of contaminants in percolating pore fluids. Simple calculations, laboratory and field testing, and analytical and numerical modeling may be used to estimate water flux through variably-saturated tailings under steady-state conditions, which develop after consolidation and dewatering have essentially ceased. Contaminant concentrations in water discharging from the tailings depend on tailings composition, leachability and solubility of contaminants, geochemical conditions within the embankment, tailings-water interactions, and flux of water through the embankment. These concentrations may be estimated based on maximum reported concentrations, pore water concentrations, extrapolations of column leaching data, or geochemical equilibria and reaction pathway modeling. Attempts to estimate contaminant discharge rates should begin with simple, conservative calculations and progress to more-complicated approaches, as necessary

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

Science.gov (United States)

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

2017-09-01

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

Calc-sodic zoning in rocks from Lagoa Real uranium Province, state of Bahia, Brazil

International Nuclear Information System (INIS)

Raposo, C.; Matos, E.C. de; Brito, W. de

1984-01-01

Preliminary studies of the lithogeochemistry, carried out on various deposits from the Uranium Province of Lagoa Real, show that in relation to the complex and multiphased processes of metasomatism, the sodic metasomatites are younger and were superposed on the potassic metasomatites. Such metasomatites developed in zones of extended and rejuvenated faults, after the transformation of the gnaisses, granitic rocks, amphibolites and ferruginous quartzites into various tectonites (mylonites, blastomylonites and protomylonites). The calcic metasomatism, subsequent to those phases, took place during the course of tectonothermal reactivations marking the termination of the principal metasomatic processes which aftected the rocks of Lagoa Real. The uranium deposit 'Jazida Laranjeiras', centrally situated in the Uranium Province of Lagoa Real is the only deposit in which the uranium mineralization is not intimately associated with the calcic metasomatism. Here, the ratio Na 2 O/CaO in the albitites is in the vicinity of 7,5 whereas in the other deposits this ratio decreases to values of about 1,5. The authors suggest calcic zoning (in the post-albitite phase) along the sigmoidal structure which localizes the uranium deposits, with an increase of the CaO content in the extreme parts of the structure - deposit 'Jazida Cachoeira' in the north and anomaly No. 02/12 in the south. Also suggested is the vertical zoning of calcium, whereby the intensity of the metasomatic phenomenon is increased towards the hanging wall side of the mieral parcel. (Author) [pt

Conceptual Model of Uranium in the Vadose Zone for Acidic and Alkaline Wastes Discharged at the Hanford Site Central Plateau

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Szecsody, James E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Serne, R. Jeffrey [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Historically, uranium was disposed in waste solutions of varying waste chemistry at the Hanford Site Central Plateau. The character of how uranium was distributed in the vadose zone during disposal, how it has continued to migrate through the vadose zone, and the magnitude of potential impacts on groundwater are strongly influenced by geochemical reactions in the vadose zone. These geochemical reactions can be significantly influenced by the disposed-waste chemistry near the disposal location. This report provides conceptual models and supporting information to describe uranium fate and transport in the vadose zone for both acidic and alkaline wastes discharged at a substantial number of waste sites in the Hanford Site Central Plateau. The conceptual models include consideration of how co-disposed acidic or alkaline fluids influence uranium mobility in terms of induced dissolution/precipitation reactions and changes in uranium sorption with a focus on the conditions near the disposal site. This information, when combined with the extensive information describing uranium fate and transport at near background pH conditions, enables focused characterization to support effective fate and transport estimates for uranium in the subsurface.

Surface and subsurface characterization of uranium contamination at the Fernald environmental management site

International Nuclear Information System (INIS)

Schilk, A.J.; Perkins, R.W.; Abel, K.H.; Brodzinski, R.L.

1993-04-01

The past operations of uranium production and support facilities at several Department of Energy (DOE) sites have occasionally resulted in the local contamination of some surface and subsurface soils, and the three-dimensional distribution of the uranium at these sites must be thoroughly characterized before any effective remedial protocols can be established. To this end, Pacific Northwest Laboratory (PNL) has been tasked by the DOE's Office of Technology Development with adapting, developing, and demonstrating technologies for the measurement of uranium in surface and subsurface soils at the Fernald Uranium in Soils Integrated Demonstration site. These studies are detailed in this report

The study on microb and organic metallogenetic process of the interlayer oxidized zone uranium deposit. A case study of the Shihongtan uranium deposit in Turpan-Hami basin

International Nuclear Information System (INIS)

Qiao Haiming; Shang Gaofeng

2010-01-01

Microbial and organic process internationally leads the field in the study of metallogenetic process presently. Focusing on Shi Hongtan uranium deposit, a typical interlayer oxidized zone sandstone-type deposit, this paper analyzes the geochemical characteristics of microb and organic matter in the deposit, and explores the interaction of microb and organic matter. It considers that the anaerobic bacterium actively takes part in the formation of the interlayer oxidized zone, as well as the mobilization and migration of uranium. In the redox (oxidation-reduction) transition zone, sulphate-reducing bacteria reduced sulphate to stink damp, lowing Eh and acidifying pH in the groundwater, which leads to reducing and absorbing of uranium, by using light hydrocarbon which is the product of the biochemical process of organism and the soluble organic matter as the source of carbon. The interaction of microb and organic matter controls the metallogenetic process of uranium in the deposit. (authors)

Influence of attrition scrubbing, ultrasonic treatment, and oxidant additions on uranium removal from contaminated soils

International Nuclear Information System (INIS)

Timpson, M.E.; Elless, M.P.; Francis, C.W.

1994-01-01

As part of the Uranium in Soils Integrated Demonstration Project being conducted by the US Department of Energy, bench-scale investigations of selective leaching of uranium from soils at the Fernald Environmental Management Project site in Ohio were conducted at Oak Ridge National Laboratory. Two soils (storage pad soil and incinerator soil), representing the major contaminant sources at the site, were extracted using carbonate- and citric acid-based lixiviants. Physical and chemical processes were used in combination with the two extractants to increase the rate of uranium release from these soils. Attrition scrubbing and ultrasonic dispersion were the two physical processes utilized. Potassium permanganate was used as an oxidizing agent to transform tetravalent uranium to the hexavalent state. Hexavalent uranium is easily complexed in solution by the carbonate radical. Attrition scrubbing increased the rate of uranium release from both soils when compared with rotary shaking. At equivalent extraction times and solids loadings, however, attrition scrubbing proved effective only on the incinerator soil. Ultrasonic treatments on the incinerator soil removed 71% of the uranium contamination in a single extraction. Multiple extractions of the same sample removed up to 90% of the uranium. Additions of potassium permanganate to the carbonate extractant resulted in significant changes in the extractability of uranium from the incinerator soil but had no effect on the storage pad soil

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Grand Junction, Colorado

Energy Technology Data Exchange (ETDEWEB)

1994-06-01

This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site Near Grand Junction, Colorado evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site. This risk assessment follows an approach outlined by the EPA. the first step is to evaluate ground water data collected from monitor wells at the site. Evaluation of these data showed that the contaminants of potential concern in the ground water are arsenic, cadmium, cobalt, fluoride, iron, manganese, molybdenum, nickel, sulfate, uranium, vanadium, zinc, and radium-226. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if they drank from a well installed in the contaminated ground water at the former processing site.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Grand Junction, Colorado

International Nuclear Information System (INIS)

1994-06-01

This Baseline Risk Assessment of Ground Water Contamination at the Uranium Mill Tailings Site Near Grand Junction, Colorado evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site. This risk assessment follows an approach outlined by the EPA. the first step is to evaluate ground water data collected from monitor wells at the site. Evaluation of these data showed that the contaminants of potential concern in the ground water are arsenic, cadmium, cobalt, fluoride, iron, manganese, molybdenum, nickel, sulfate, uranium, vanadium, zinc, and radium-226. The next step in the risk assessment is to estimate how much of these contaminants people would be exposed to if they drank from a well installed in the contaminated ground water at the former processing site

Contaminant distributions at typical U.S. uranium milling facilities and their effect on remedial action decisions

International Nuclear Information System (INIS)

Hamp, S.; Dotson, P.W.

1995-01-01

Past operations at uranium processing sites throughout the US have resulted in local contamination of soils and ground water by radionuclides, toxic metals, or both. Understanding the origin of contamination and how the constituents are distributed is a basic element for planning remedial action decisions. This report describes the radiological and nonradiological species found in ground water at a typical US uranium milling facility. The report will provide the audience with an understanding of the vast spectrum of contaminants that must be controlled in planning solutions to the long-term management of these waste materials

Integrated geophysical investigations for the delineation of source and subsurface structure associated with hydro-uranium anomaly: A case study from South Purulia Shear Zone (SPSZ), India

Science.gov (United States)

Sharma, S. P.; Biswas, A.

2012-12-01

South Purulia Shear Zone (SPSZ) is an important region for prospecting of uranium mineralization. Geological studies and hydro-uranium anomaly suggest the presence of Uranium deposit around Raghunathpur village which lies about 8 km north of SPSZ. However, detailed geophysical investigations have not been carried out in this region for investigation of uranium mineralization. Since surface signature of uranium mineralization is not depicted near the location, a deeper subsurface source is expected for hydro uranium anomaly. To delineate the subsurface structure and to investigate the origin of hydro-uranium anomaly present in the area, Vertical Electrical Sounding (VES) using Schlumberger array and Gradient Resistivity Profiling (GRP) were performed at different locations along a profile perpendicular to the South Purulia Shear Zone. Apparent resistivity computed from the measured sounding data at various locations shows a continuously increasing trend. As a result, conventional apparent resistivity data is not able to detect the possible source of hydro uranium anomaly. An innovative approach is applied which depicts the apparent conductivity in the subsurface revealed a possible connection from SPSZ to Raghunathpur. On the other hand resistivity profiling data suggests a low resistive zone which is also characterized by low Self-Potential (SP) anomaly zone. Since SPSZ is characterized by the source of uranium mineralization; hydro-uranium anomaly at Raghunathpur is connected with the SPSZ. The conducting zone has been delineated from SPSZ to Raghunathpur at deeper depths which could be uranium bearing. Since the location is also characterized by a low gravity and high magnetic anomaly zone, this conducting zone is likely to be mineralized zone. Keywords: Apparent resistivity; apparent conductivity; Self Potential; Uranium mineralization; shear zone; hydro-uranium anomaly.

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Canonsburg, Pennsylvania

International Nuclear Information System (INIS)

1994-09-01

This baseline risk assessment evaluates potential impacts to public health and the environment resulting from ground water contamination from past activities at the former uranium processing site in Canonsburg, Pennsylvania. The US Department of Energy Uranium Mill Tailings Remedial Action (UMTRA) Project has placed contaminated material from this site in an on-site disposal cell. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the UMTRA Ground Water Project. Currently, no domestic or drinking water well tap into contaminated ground water of the two distinct ground water units: the unconsolidated materials and the bedrock. Because there is no access, no current health or environmental risks are associated with the direct use of the contaminated ground water. However, humans and ecological organisms could be exposed to contaminated ground water if a domestic well were to be installed in the unconsolidated materials in that part of the site being considered for public use (Area C). The first step is evaluating ground water data collected from monitor wells at the site. For the Canonsburg site, this evaluation showed the contaminants in ground water exceeding background in the unconsolidated materials in Area C are ammonia, boron, calcium, manganese, molybdenum, potassium, strontium, and uranium

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Canonsburg, Pennsylvania

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

This baseline risk assessment evaluates potential impacts to public health and the environment resulting from ground water contamination from past activities at the former uranium processing site in Canonsburg, Pennsylvania. The US Department of Energy Uranium Mill Tailings Remedial Action (UMTRA) Project has placed contaminated material from this site in an on-site disposal cell. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the UMTRA Ground Water Project. Currently, no domestic or drinking water well tap into contaminated ground water of the two distinct ground water units: the unconsolidated materials and the bedrock. Because there is no access, no current health or environmental risks are associated with the direct use of the contaminated ground water. However, humans and ecological organisms could be exposed to contaminated ground water if a domestic well were to be installed in the unconsolidated materials in that part of the site being considered for public use (Area C). The first step is evaluating ground water data collected from monitor wells at the site. For the Canonsburg site, this evaluation showed the contaminants in ground water exceeding background in the unconsolidated materials in Area C are ammonia, boron, calcium, manganese, molybdenum, potassium, strontium, and uranium.

Environmental restoration plans and activities in the zones of uranium ore extraction and milling in Romania: 1995-1996 progress report

International Nuclear Information System (INIS)

Bejenaru, C.; Ionescu, I.; Georgescu, D.

1997-01-01

The objective of this paper is to present the ecological impact on environment as a consequence of more than 30 years of activity in the field of uranium exploration, mining and ore processing in Romania and a brief description of the measures taken for limiting the effects of contamination on the affected zones including the proposed restructuring and rehabilitation programmes. The Autonomous Regie for Rare Metals (RAMR), the coordinator of the activities in the uranium field is responsible to implement the provisions of the IAEA Technical Cooperation Project on Environmental Restoration in Central and Eastern Europe joined by Romania in 1993. The characterization of radioactively contaminated areas is dealt with broadly under two categories, one pertaining to sites where the mining and milling activities have already ceased and the other where the units are still operational but are going to be closed down in the near future and will be placed under surveillance. Generally speaking, the activity in the uranium field is developed by observing the national Norms of Nuclear Safety for the Activity of Geological Investigation, Mining and Milling of Nuclear Raw Material. This report includes an evaluation of the necessary investments for the first stage of the programme dealing with the environmental restoration and the necessary research activities. This will be followed by studies for closing down and surveillance of the mines with special problems taking into account their depth and complex hydrology

Characterization of Direct Push Vadose Zone Sediments from the T and TY Waste Management Areas

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F.; Valenta, Michelle M.; Serne, R. Jeffrey; Bjornstad, Bruce N.; Lanigan, David C.; Iovin, Cristian; Clayton, Ray E.; Geiszler, Keith N.; Clayton, Eric T.; Kutnyakov, Igor V.; Baum, Steven R.; Lindberg, Michael J.; Orr, Robert D.

2007-06-08

This report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from 5 direct push characterization holes emplaced to investigate vadose zone contamination associated with leaks from tanks 241-TY-105 (UPR-200-W-152) and 241-TY-106 (UPR-200-W-153). Tank 241-TY-105 is estimated to have leaked 35,000 gal of tributyl phosphate (TBP) waste from the uranium recovery process to the vadose zone in 1960. Tank 241-TY-106 is estimated to have leaked 20,000 gal of TBP-uranium recovery waste to the vadose zone in 1959. Although several drywells in the vicinity of tank 241-TY-106 contain measurable quantities of cesium-137 and/or cobalt-60, their relatively low concentrations indicate that the contaminant inventory in the vadose zone around tank 241-TY-106 is quite small. Additionally, this report contains all the geochemical and selected physical characterization data collected on vadose zone sediment recovered from 7 direct push characterization holes emplaced to investigate vadose zone contamination associated with an overfill event and leak from tank 241-T-101.

The use of geochemical barriers for reducing contaminants emanating from uranium mill tailings

International Nuclear Information System (INIS)

Groffman, A.R.; Longmire, P.; Mukhopadhyay, B.; Downs, W.

1991-01-01

A problem facing the Department of Energy's Uranium Mill Tailings Remediation Action (UMTRA) Project is the contamination of local ground water by leachate emanating form the tailings piles. These fluids have a low pH and contain heavy metals and trace elements such as arsenic, molybdenum, nitrate, selenium, and uranium. In order to meet ground water standards low hydraulic conductivity covers are installed over the tailings embankment. in some cases it may be necessary to install a geochemical barrier down gradient from the tailings embankment in order to remove the hazardous constituents. By using geochemical barriers to reduce undesirable species form a contaminant plume, fluids emanating form beneath a repository can in effect be scrubbed before entering the water table. Materials containing adsorbing clays, iron oxyhydroxides and zeolites, and reducing materials such as coal and peat, are being used effectively to attenuate contaminants form uranium mill tailings. Experiments to directly determine attenuation capacities of selected buffer/adsorption materials were conducted in the laboratory. Batch leach tests were conducted in lieu of column tests when the hydraulic conductivity of materials was too low to use in columns and shales

Bacterial biodiversity analysis of a contaminated soil from the Chernobyl exclusion zone and characterization of the committed interaction of a Microbacterium strain with uranium

International Nuclear Information System (INIS)

Theodorakopoulos, Nicolas

2013-01-01

The nuclear power plants accidents of Chernobyl and Fukushima demonstrate the importance of the understanding of the transfer of the radioactive contamination in the environment and its ecological consequences. Although certain studies have been realized on superior organisms of the food chain, studies on telluric bacterial communities are scarce. The latter play nevertheless an essential role in the mobility of contaminants in soils by decreasing or improving their transfer towards other compartments (water, vegetables and animals). Moreover radionuclides (RNs) can have toxic effects on bacteria, leading to an inhibition of their participation in such transfer. The objectives of this study were (1) to estimate the impact of the radioactive contamination on bacterial communities belonging to a soil of the Chernobyl exclusion zone (trench T22) and (2) to study the uranium-bacteria interactions of a resistant strain, isolated from this soil. The various techniques used to characterize the bacterial diversity (culture of bacteria, DGGE, 454 pyro-sequencing) all testified of the multiplicity and the abundance of the bacterial communities in spite of the contamination. An impact on the community structure was difficult to assess by DGGE or cultural approach, but was nevertheless highlighted by the use of pyro-sequencing, suggesting the presence of species more adapted to the contaminated soil conditions. A specific molecular tool dedicated to the search of bacteria affiliated to the known radiation resistant Deinococcus-Thermus phylum (for example the Deinococcus radiodurans specie survives after an irradiation of several kGy) was developed. However it did not reveal the presence of bacteria affiliated to such a phylum in the studied soil. In parallel to the study of the bacterial biodiversity, about fifty culturable bacteria were isolated from this site and were used as a support to select a species (Microbacterium) capable to survive strong U(VI) concentrations. The

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Tuba City, Arizona

International Nuclear Information System (INIS)

1994-06-01

This document evaluates potential public health or environmental impacts resulting from ground water contamination at the former uranium mill site. The tailings and other contaminated material at this site were placed in a disposal cell on the site in 1990 by the US Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project is to evaluate ground water contamination. This risk assessment is the first site-specific document under the Ground Water Project. It will help determine what remedial actions are necessary for contaminated ground water at the site

Study on metallogenetic prospect of interlayer oxidation zone sandstone type uranium deposit in Shanganning basin

International Nuclear Information System (INIS)

Wang Jinping

1998-01-01

As Compared with orogenic zone basin, which the interlayer oxidation zone sandstone type uranium deposits are found, the Shanganning basin a continental platform type basin is distinct either in the geodynamic background and the post-basin hydrogeological evolution or in the appearance of the metallogenetic dynamics-orogenesis. The prediction criteria summarized for interlayer oxidation zone type U-deposits in Middle Asia therefore can not be completely applied in such a basin. Based on analysis of the typical regional geological setting, the hydrogeology of the Meso-Cenozoic cover is studied in detail. Three hydrogeological cycles have been divided, and prospects of uranium deposits have been clarified and the most promising target have been proposed

Contribution of the surface contamination of uranium-materials on the quantitative analysis results by electron probe microbeam analysis

International Nuclear Information System (INIS)

Bonino, O.; Fournier, C.; Fucili, C.; Dugne, O.; Merlet, C.

2000-01-01

The analytical testing of uranium materials is necessary for quality research and development in nuclear industry applications (enrichment, safety studies, fuel, etc). Electron Probe Microbeam Analysis Wavelength Dispersive Spectrometry (EPMA-WDS) is a dependable non-destructive analytical technology. The characteristic X-ray signal is measured to identify and quantify the sample components, and the analyzed volume is about one micron cube. The surface contamination of uranium materials modifies and contributes to the quantitative analysis results of EPMA-WDS. This contribution is not representative of the bulk. A thin oxidized layer appears in the first instants after preparation (burnishing, cleaning) as well as a carbon contamination layer, due to metallographic preparation and carbon cracking under the impact of the electron probe. Several analytical difficulties subsequently arise, including an overlapping line between the carbon Ka ray and the Uranium U NIVOVI ray. Sensitivity and accuracy of the quantification of light elements like carbon and oxygen are also reduced by the presence of uranium. The aim of this study was to improve the accuracy of quantitative analysis on uranium materials by EPMA-WDS by taking account of the contribution of surface contamination. The first part of this paper is devoted to the study of the contaminated surface of the uranium materials U, UFe 2 and U 6 Fe a few hours after preparation. These oxidation conditions are selected so as to reproduce the same contamination surfaces occurring in microprobe analytical conditions. Surface characterization techniques were SIMS and Auger spectroscopy. The contaminated surfaces are shown. They consist of successive layers: a carbon layer, an oxidized iron layer, followed by an iron depletion layer (only in UFe 2 and U 6 Fe), and a ternary oxide layer (U-Fe-O for UFe 2 et U 6 Fe and UO 2+x for uranium). The second part of the paper addresses the estimation of the errors in quantitative

Assessment of surface contamination level in an operating uranium ore processing facility of Jaduguda, India

International Nuclear Information System (INIS)

Meena, J.S.; Patnaik, R.L.; Jha, V.N.; Sahoo, S.K.; Ravi, P.M.; Tripathi, R.M.

2014-01-01

Radiological concern of the occupational workers and the area is given priority over other safety issue in confirmation with the stipulated guideline of national regulatory agency (AERB/FEFCF/SG-2, 2007). The key concern from the radiological hazard evaluation point of view is air activity, external gamma level and surface contamination. Present investigations was carried out to ascertain the surface contamination level of uranium ore processing facility at Jaduguda, Jharkhand. For a low grade uranium ore processing industry surface contamination is a major concern in product precipitation and recovery section. In view of this, the ore processing plant can broadly be classified into three areas i.e. ion exchange area, precipitation and product recovery section and other areas. The monitoring results incorporate the level of surface contamination of the plant during the last five years. The geometric mean activity of surface contamination level was 31.1, 34.5 and 9.8 Bq dm -2 in ion exchange, product precipitation and recovery and other areas with GSD of 2, 2.5 and 1.9. In most of the cases the surface contamination level was well within the recommended limit of 100 Bq dm -2 for M class uranium compound. Occasional cases of surface contamination levels exceeding the recommended limit were addressed and areas were decontaminated. Based on the study, modification in the design feature of the surface of the finished product section was also suggested so that the decontamination procedure can be more effectively implemented

Subsurface Nitrogen-Cycling Microbial Communities at Uranium Contaminated Sites in the Colorado River Basin

Science.gov (United States)

Cardarelli, E.; Bargar, J.; Williams, K. H.; Dam, W. L.; Francis, C.

2015-12-01

Throughout the Colorado River Basin (CRB), uranium (U) persists as a relic contaminant of former ore processing activities. Elevated solid-phase U levels exist in fine-grained, naturally-reduced zone (NRZ) sediments intermittently found within the subsurface floodplain alluvium of the following Department of Energy-Legacy Management sites: Rifle, CO; Naturita, CO; and Grand Junction, CO. Coupled with groundwater fluctuations that alter the subsurface redox conditions, previous evidence from Rifle, CO suggests this resupply of U may be controlled by microbially-produced nitrite and nitrate. Nitrification, the two-step process of archaeal and bacterial ammonia-oxidation followed by bacterial nitrite oxidation, generates nitrate under oxic conditions. Our hypothesis is that when elevated groundwater levels recede and the subsurface system becomes anoxic, the nitrate diffuses into the reduced interiors of the NRZ and stimulates denitrification, the stepwise anaerobic reduction of nitrate/nitrite to dinitrogen gas. Denitrification may then be coupled to the oxidation of sediment-bound U(IV) forming mobile U(VI), allowing it to resupply U into local groundwater supplies. A key step in substantiating this hypothesis is to demonstrate the presence of nitrogen-cycling organisms in U-contaminated, NRZ sediments from the upper CRB. Here we investigate how the diversity and abundances of nitrifying and denitrifying microbial populations change throughout the NRZs of the subsurface by using functional gene markers for ammonia-oxidation (amoA, encoding the α-subunit of ammonia monooxygenase) and denitrification (nirK, nirS, encoding nitrite reductase). Microbial diversity has been assessed via clone libraries, while abundances have been determined through quantitative polymerase chain reaction (qPCR), elucidating how relative numbers of nitrifiers (amoA) and denitrifiers (nirK, nirS) vary with depth, vary with location, and relate to uranium release within NRZs in sediment

Non-radiological contaminants from uranium mining and milling at Ranger, Jabiru, Northern Territory, Australia.

Science.gov (United States)

Noller, B N

1991-10-01

Protection from the hazards from radioactivity is of prime importance in the management of uranium mine and mill wastes. Such wastes also contain non-radiological contaminants (heavy metals, acids and neutralising agents) which give rise to potential long-term health and environmental hazards and short-term hazards to the aquatic ecosystem, e.g. as a result of release of waste water. This study seeks to identify non-radiological contaminants (elements) transferred to waste water at the Ranger uranium mine/mill complex at Jabiru, which are likely to hazardous to the aquatic environment.The two principal sources of contaminants are: (i) ore and waste rock mobilised from mining; and (ii) process reagents used in the milling and mineral extraction process. These substances may or may not already be present in the natural environment but may lead to deleterious effects on the aquatic environment if increased above threshold levels.Rhenium, derived from the ore body, was found to be significantly enriched in waste water from Ranger, indicating its suitability as an indicator element for water originating from the mining and milling process, but only uranium, likewise derived from the ore, and magnesium, manganese and sulfur (as sulfate) from the milling process were found to be significant environmental contaminants.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Riverton, Wyoming

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

This Risk Assessment evaluated potential impacts to public health or the environment caused by ground water contamination at the former uranium mill processing site. In the first phase of the U.S. Department of Energy`s Uranium Mill Tailings Remedial Action (UMTRA) Project, the tailing and other contaminated material at this site were placed in a disposal cell near the Gas Hills Plant in 1990. The second phase of the UMTRA Project is to evaluate ground water contamination. This risk assessment is the first site-specific document to evaluate potential health and environmental risks for the Riverton site under the Ground Water Project; it will help determine whether remedial actions are needed for contaminated ground water at the site.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Riverton, Wyoming

International Nuclear Information System (INIS)

1994-09-01

This Risk Assessment evaluated potential impacts to public health or the environment caused by ground water contamination at the former uranium mill processing site. In the first phase of the U.S. Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Project, the tailing and other contaminated material at this site were placed in a disposal cell near the Gas Hills Plant in 1990. The second phase of the UMTRA Project is to evaluate ground water contamination. This risk assessment is the first site-specific document to evaluate potential health and environmental risks for the Riverton site under the Ground Water Project; it will help determine whether remedial actions are needed for contaminated ground water at the site

Baseline risk assessment of ground water contamination at the Monument Valley uranium mill tailings site Cane Valley, Arizona

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the Monument Valley UMTRA Project site near Cane Valley, Arizona, was completed in 1994. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Adverse ecological and agricultural effects may also result from exposure to contaminated ground water. For example, livestock should not be watered with contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site investigations will be used to determine a compliance strategy to comply with the UMTRA ground water standards.

Baseline risk assessment of ground water contamination at the Monument Valley uranium mill tailings site Cane Valley, Arizona

International Nuclear Information System (INIS)

1996-03-01

The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the Monument Valley UMTRA Project site near Cane Valley, Arizona, was completed in 1994. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Adverse ecological and agricultural effects may also result from exposure to contaminated ground water. For example, livestock should not be watered with contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site investigations will be used to determine a compliance strategy to comply with the UMTRA ground water standards

Decontamination of Uranium-Contaminated Soil Sand Using Supercritical CO2 with a TBP–HNO3 Complex

Directory of Open Access Journals (Sweden)

Kwangheon Park

2015-09-01

Full Text Available An environmentally friendly decontamination process for uranium-contaminated soil sand is proposed. The process uses supercritical CO2 as the cleaning solvent and a TBP–HNO3 complex as the reagent. Four types of samples (sea sand and coarse, medium, and fine soil sand were artificially contaminated with uranium. The effects of the amount of the reagent, sand type, and elapsed time after the preparation of the samples on decontamination were examined. The extraction ratios of uranium in all of the four types of sand samples were very high when the time that elapsed after preparation was less than a few days. The extraction ratio of uranium decreased in the soil sand with a higher surface area as the elapsed time increased, indicating the possible formation of chemisorbed uranium on the surface of the samples. The solvent of supercritical CO2 seemed to be very effective in the decontamination of soil sand. However, the extraction of chemisorbed uranium in soil sand may need additional processes, such as the application of mechanical vibration and the addition of bond-breaking reagents.

Removal of uranium from contaminated soil using indoor electrokinetic decontamination

International Nuclear Information System (INIS)

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

2016-01-01

Indoor electrokinetic decontamination equipment was manufactured to treat 1.2 tons of uranium-contaminated soil. For a reduction of waste electrolyte and metal oxide, waste electrolyte was reused and the optimum pH was adjusted to minimize metal oxide volume in the cathode chamber. It was found that the optimum pH of the waste electrolyte in a cathode chamber was below 2.35 at 25 deg C. When the initial uranium concentrations in the soils were 7.0-27.0 Bq/g, the reuse periods of waste electrolyte required for uranium concentrations in the soils to reach below 5.0 Bq/g were 5-25 days. In addition, when the initial concentrations in the soils were 7.0-20.0 Bq/g, the periods required to reach below the clearance concentration level were 25-40 days.

Na-metasomatism in the uranium fields of Singhbhum Shear zone, India

International Nuclear Information System (INIS)

Chaki, Anjan

2013-01-01

Singhbhum Shear Zone (SSZ) of eastern India hosts uranium, copper and apatite-magnetite mineralization, which occurs either independently or overlaps in space. SSZ is a nearly 200 km long, 1-5 km wide, intensely techtonized, northward-convex, arcuate mobile belt that separates the Archaean cratonic nucleus to its south from the Proterozoic North Singhbhum Fold Belt on the north. Except Bagjata mines in the eastern sector, majority of the known uranium deposits and mines (e.g. Jaduguda, Bhatin, Narwapahar, Banduhurang and Mohuldih) are situated in the central sector of the shear zone. All the deposits are of low grade (0.05% U 3 O 8 ) and low to medium tonnage. The common rock types of the SSZ are quartz-chlorite schists, quartzsericite schists, quartzite, metaconglomerate, soda granite, quartz-albite bearing schists/gneisses, granophyres and tourmalinite. The mineralization occur as lenticular to tabular bodies, which are (pene-) concordant with dominant planer structures, i.e. foliation parallel with the lithological layering (S 3 II S 0 ). Principal uranium mineral is uraninite with low thorium (UO 2 /ThO 2 =70-150), high lead (PbO =14-15%) and moderate REE contents with minor pitchblende and some secondary minerals near the surface. Many ore minerals, particularly the sulfide phases of Ni, Co, Mo, Cu and Fe are common

Assessment of the environmental radioactive contamination levels by depleted uranium after NATO aggression on FR Yugoslavia

International Nuclear Information System (INIS)

Pavlovic, S.; Pavlovic, R.; Markovic, S; Plecas, I.

2001-01-01

During NATO aggression on FR Yugoslavia various ammunition have been used, some of them for the first time. Among others, 30 mm bullets with depleted uranium (DU) penetrators have been used. Radioactivity contamination surveys have started during the war due to indications that DU is used in cruise missiles. Besides that, there were a lot of radioactivity analysis of food, drinking water etc. Some of the obtained results are presented in this paper. Depleted uranium ammunition can permanently contaminate environment and so produce effects on population. Relation of the international radiation and environmental protection standards and contamination levels are discussed as well. (author)

Evaluation of uranium anomalies in the Hylas zone and northern Richmond basin, east-central Virginia

International Nuclear Information System (INIS)

Baillieul, T.A.; Dexter, J.J.

1982-01-01

Conclusions from this study are: (1) Radon values in ground water from the Hylas Zone and the adjacent Richmomd Basin are anomalous and may indicate nearby uranium-enriched source rocks. (2) Pegmatites, protomylonitic granite, and the Petersburg Granite can be good sources of uranium for ground water. The pegmatites described in this report appear to be the best source rocks because of uranium values ranging from 82 to 235 ppM eU and corresponding low values of Th as well (average Th/U = 0.18). The protomylonitic granite has an average Th/U ratio of 0.5. Ground-water samples (ranging from 70 to 270 ppB uranium) from southwest Richmond are believed to have originated from a major ground-water system at the contact of the Petersburg Granite and overlying coastal plain sediments. Thus, the Petersburg Granite may be considered a possible source of uranium available to ground water entering the Richmond Basin. (3) The Richmond Basin could host uranium deposits of the sandstone class. As mentioned above, there appears to be an adequate supply of uranium in rocks surrounding the basin. The basin environment is presently classified as unevaluated. Further work is warranted on the basis of this study. (4) Pegmatites in the Hylas Zone could be favorable for the occurrence of uranium deposits of the pegmatitic class. However, it is not known how the uranium occurs in the pegmatites, and only pegmatites exposed in the Boscobel quarry were examined. Therefore, this environment remains unevaluated. 3 figures, 4 tables

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Shiprock, New Mexico

International Nuclear Information System (INIS)

1994-04-01

This baseline risk assessment at the former uranium mill tailings site near Shiprock, New Mexico, evaluates the potential impact to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an on-site disposal cell in 1986 through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. There are no domestic or drinking water wells in the contaminated ground water of the two distinct ground water units: the contaminated ground water in the San Juan River floodplain alluvium below the site and the contaminated ground water in the terrace alluvium area where the disposal cell is located. Because no one is drinking the affected ground water, there are currently no health or environmental risks directly associated with the contaminated ground water. However, there is a potential for humans, domestic animals, and wildlife to the exposed to surface expressions of ground water in the seeps and pools in the area of the San Juan River floodplain below the site. For these reasons, this risk assessment evaluates potential exposure to contaminated surface water and seeps as well as potential future use of contaminated ground water

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Canonsburg, Pennsylvania. Revision 1

International Nuclear Information System (INIS)

1995-11-01

For the UMTRA Project site located near Canonsburg, Pennsylvania (the Canonsburg site), the Surface Project cleanup occurred from 1983 to 1985, and involved removing the uranium processing mill tailings and radioactively contaminated soils and materials from their original locations and placing them in a disposal cell located on the former Canonsburg uranium mill site. This disposal cell is designed to minimize radiation emissions and further contamination of ground water beneath the site. The Ground Water Project will evaluate the nature and the extent of ground water contamination resulting from uranium processing at the former Canonsburg uranium mill site, and will determine a ground water strategy for complying with the US Environmental Protection Agency's (EPA) ground water standards established for the UMTRA Project. For the Canonsburg site, an evaluation was made to determine whether exposure to ground water contaminated by uranium processing could affect people's health. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Canonsburg site. The results of this report and further site characterization of the Canonsburg site will be used to determine how to protect public health and the environment, and how to comply with the EPA standards

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Canonsburg, Pennsylvania. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

For the UMTRA Project site located near Canonsburg, Pennsylvania (the Canonsburg site), the Surface Project cleanup occurred from 1983 to 1985, and involved removing the uranium processing mill tailings and radioactively contaminated soils and materials from their original locations and placing them in a disposal cell located on the former Canonsburg uranium mill site. This disposal cell is designed to minimize radiation emissions and further contamination of ground water beneath the site. The Ground Water Project will evaluate the nature and the extent of ground water contamination resulting from uranium processing at the former Canonsburg uranium mill site, and will determine a ground water strategy for complying with the US Environmental Protection Agency`s (EPA) ground water standards established for the UMTRA Project. For the Canonsburg site, an evaluation was made to determine whether exposure to ground water contaminated by uranium processing could affect people`s health. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Canonsburg site. The results of this report and further site characterization of the Canonsburg site will be used to determine how to protect public health and the environment, and how to comply with the EPA standards.

Use of Polyphosphate to Decrease Uranium Leaching in Hanford 300 Area Smear Zone Sediments

Energy Technology Data Exchange (ETDEWEB)

Szecsody, James E.; Zhong, Lirong; Oostrom, Martinus; Vermeul, Vincent R.; Fruchter, Jonathan S.; Williams, Mark D.

2012-09-30

The primary objective of this study is to summarize the laboratory investigations performed to evaluate short- and long-term effects of phosphate treatment on uranium leaching from 300 area smear zone sediments. Column studies were used to compare uranium leaching in phosphate-treated to untreated sediments over a year with multiple stop flow events to evaluate longevity of the uranium leaching rate and mass. A secondary objective was to compare polyphosphate injection, polyphosphate/xanthan injection, and polyphosphate infiltration technologies that deliver phosphate to sediment.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Rifle, Colorado. Revision 2

International Nuclear Information System (INIS)

1996-02-01

The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further ground water contamination. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. Two UMTRA Project sites are near Rifle, Colorado: the Old Rifle site and the New Rifle site. Surface cleanup at the two sites is under way and is scheduled for completion in 1996. The Ground Water Project is in its beginning stages. A risk assessment identifies a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the environment may be exposed, and the health or environmental effects that could result from that exposure. This report is a site-specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. This evaluation and further site characterization will be used to determine if action is needed to protect human health or the environment. Human health risk may result from exposure to ground water contaminated from uranium ore processing. Exposure could occur from drinking water obtained from a well placed in the areas of contamination. Furthermore, environmental risk may result from plant or animal exposure to surface water and sediment that have received contaminated ground water

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Rifle, Colorado. Revision 2

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-02-01

The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further ground water contamination. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. Two UMTRA Project sites are near Rifle, Colorado: the Old Rifle site and the New Rifle site. Surface cleanup at the two sites is under way and is scheduled for completion in 1996. The Ground Water Project is in its beginning stages. A risk assessment identifies a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the environment may be exposed, and the health or environmental effects that could result from that exposure. This report is a site-specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. This evaluation and further site characterization will be used to determine if action is needed to protect human health or the environment. Human health risk may result from exposure to ground water contaminated from uranium ore processing. Exposure could occur from drinking water obtained from a well placed in the areas of contamination. Furthermore, environmental risk may result from plant or animal exposure to surface water and sediment that have received contaminated ground water.

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1996-03-01

The U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase I) and the Ground Water Project (Phase II). Under the UMTRA Surface Project, tailings, contaminated soil, equipment, and materials associated with the former uranium ore processing at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to minimize further contamination of ground water. Surface cleanup at the UMTRA Project site near Lakeview, Oregon, was completed in 1989. The mill operated from February 1958 to November 1960. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment.

Contribution to the study of renal load and its therapeutic modifications during acute uranium contaminations

International Nuclear Information System (INIS)

Bourguignon, M.H.N.

1977-01-01

The renal load during acute experimental contaminations in rats and the possible effects of treatment with chelators (DTPA) and bicarbonates are estinated. The following points are examined in turn: kidney uptake of uranyl nitrate and therapeutic tests; in vitro solubility of oxides UO 3 and U 3 O 8 in synthetic serum, their kidney uptake and therapeutic tests. The experimental values of the in vitro uranium oxide dissolution method were checked against in vivo observations. These experiments lead to the following conclusions: concerning the solubility of uranium compounds the strong solubility of UO 3 and much lesser solubility of U 3 O 8 in biological media are confirmed; with regard to the kidney uptake of uranium derivatives the fixation is proportional to the amount injected when the compound (uranyl nitrate) is soluble, which would correspond to the dissolved fraction in the case of more or less insoluble oxide. The right-left uptake is symmetrical. The therapeutic conclusions are as follows: the effectiveness of DTPA, in clearing the organism, especially from bone contamination is proved, but the renal uranium load is neither increased nor reduced; single injections of bicarbonates appear to reduce the kidney load in cases of U 3 O 8 contamination but are ineffective for UO 3 and UO 2 ++ . This difference may be explained by the low circulating concentration, due to weak contamination and low solubility, of U 3 O 8 as compared with the other two compounds [fr

Baseline risk assessment of ground water contamination at the uranium mill tailings sites near Slick Rock, Colorado

International Nuclear Information System (INIS)

1994-11-01

This baseline risk assessment of ground water contamination at the uranium mill tailings sites near Slick Rock, Colorado, evaluates potential public health and environmental impacts resulting from ground water contamination at the former North Continent (NC) and Union Carbide (UC) uranium mill processing sites. The tailings at these sites will be placed in a disposal cell at the proposed Burro Canyon, Colorado, site. The US Department of Energy (DOE) anticipates the start of the first phase remedial action by the spring of 1995 under the direction of the DOE's Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project will evaluate ground water contamination. This baseline risk assessment is the first site-specific document for these sites under the Ground Water Project. It will help determine the compliance strategy for contaminated ground water at the site. In addition, surface water and sediment are qualitatively evaluated in this report

Baseline risk assessment of ground water contamination at the uranium mill tailings sites near Slick Rock, Colorado

Energy Technology Data Exchange (ETDEWEB)

1994-11-01

This baseline risk assessment of ground water contamination at the uranium mill tailings sites near Slick Rock, Colorado, evaluates potential public health and environmental impacts resulting from ground water contamination at the former North Continent (NC) and Union Carbide (UC) uranium mill processing sites. The tailings at these sites will be placed in a disposal cell at the proposed Burro Canyon, Colorado, site. The US Department of Energy (DOE) anticipates the start of the first phase remedial action by the spring of 1995 under the direction of the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. The second phase of the UMTRA Project will evaluate ground water contamination. This baseline risk assessment is the first site-specific document for these sites under the Ground Water Project. It will help determine the compliance strategy for contaminated ground water at the site. In addition, surface water and sediment are qualitatively evaluated in this report.

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

Science.gov (United States)

Davis, J. A.; Smith, R. L.; Bohlke, J. K.; Jemison, N.; Xiang, H.; Repert, D. A.; Yuan, X.; Williams, K. H.

2015-12-01

The occurrence of naturally reduced zones is common in alluvial aquifers in the western U.S.A. due to the burial of woody debris in flood plains. Such reduced zones are usually heterogeneously dispersed in these aquifers and characterized by high concentrations of organic carbon, reduced mineral phases, and reduced forms of metals, including uranium(IV). The persistence of high concentrations of dissolved uranium(VI) at uranium-contaminated aquifers on the Colorado Plateau has been attributed to slow oxidation of insoluble uranium(IV) mineral phases found in association with these reducing zones, although there is little understanding of the relative importance of various potential oxidants. Four field experiments were conducted within an alluvial aquifer adjacent to the Colorado River near Rifle, CO, wherein groundwater associated with the naturally reduced zones was pumped into a gas-impermeable tank, mixed with a conservative tracer (Br-), bubbled with a gas phase composed of 97% O2 and 3% CO2, and then returned to the subsurface in the same well from which it was withdrawn. Within minutes of re-injection of the oxygenated groundwater, dissolved uranium(VI) concentrations increased from less than 1 μM to greater than 2.5 μM, demonstrating that oxygen can be an important oxidant for uranium in such field systems if supplied to the naturally reduced zones. Dissolved Fe(II) concentrations decreased to the detection limit, but increases in sulfate could not be detected due to high background concentrations. Changes in nitrogen species concentrations were variable. The results contrast with other laboratory and field results in which oxygen was introduced to systems containing high concentrations of mackinawite (FeS), rather than the more crystalline iron sulfides found in aged, naturally reduced zones. The flux of oxygen to the naturally reduced zones in the alluvial aquifers occurs mainly through interactions between groundwater and gas phases at the water table

Baseline risk assessment for groundwater contamination at the uranium mill tailings site near Monument Valley, Arizona

International Nuclear Information System (INIS)

1993-09-01

This baseline risk assessment evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site near Monument Valley, Arizona. The tailings and other contaminated material at this site are being relocated and stabilized in a disposal cell at Mexican Hat, Utah, through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The tailings removal is planned for completion by spring 1994. After the tailings are removed, groundwater contamination at the site will continue to be evaluated. This risk assessment is the first document specific to this site for the Groundwater Project. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site

Uranium mill tailings neutralization: contaminant complexation and tailings leaching studies

International Nuclear Information System (INIS)

Opitz, B.E.; Dodson, M.E.; Serne, R.J.

1985-05-01

Laboratory experiments were performed to compare the effectiveness of limestone (CaCO 3 ) and hydrated lime [Ca(OH) 2 ] for improving waste water quality through the neutralization of acidic uranium mill tailings liquor. The experiments were designed to also assess the effects of three proposed mechanisms - carbonate complexation, elevated pH, and colloidal particle adsorption - on the solubility of toxic contaminants found in a typical uranium mill waste solution. Of special interest were the effects each of these possible mechanisms had on the solution concentrations of trace metals such as Cd, Co, Mo, Zn, and U after neutralization. Results indicated that the neutralization of acidic tailings to a pH of 7.3 using hydrated lime provided the highest overall waste water quality. Both the presence of a carbonate source or elevating solution pH beyond pH = 7.3 resulted in a lowering of previously achieved water quality, while adsorption of contaminants onto colloidal particles was not found to affect the solution concentration of any constituent investigated. 24 refs., 8 figs., 19 tabs

Laboratory studies on natural restoration of ground water after in-situ leach uranium mining

International Nuclear Information System (INIS)

Bell, N.E.; Deutsch, W.J.; Serne, R.J.

1983-05-01

When uranium is mined using in-situ leach techniques, the chemical quality of the ground water in the ore-zone aquifer is affected. This could lead to long-term degradation of the ground water if restoration techniques are not applied after the leaching is completed. Pacific Northwest Laboratory (PNL), is conducting an NRC-sponsored research project on natural restoration and induced-restoration techniques. Laboratory studies were designed to evaluate the ability of the natural system (ore-zone sediments and groundwater) to mitigate the effects of mining on aquifer chemistry. Using batch and flow-through column experiments [performed with lixiviant (leaching solution) and sediments from the reduced zone of an ore-zone aquifer], we found that the natural system can lower uranium and bicarbonate concentrations in solutions and reduce the lixiviant redox potential (Eh). The change in redox potential could cause some of the contaminants that were dissolved during the uranium leaching operation to precipitate, thereby lowering their solution concentration. The concentrations of other species such as calcium, potassium, and sulfate increased, possibly as a result of mineral dissolution and ion exchange. In this paper, we describe the experimentally determined mobility of contaminants after in-situ leach mining, and discuss the possible chemical process affecting mobility

Laboratory studies on natural restoration of ground water after in-situ leach uranium mining

Energy Technology Data Exchange (ETDEWEB)

Bell, N.E.; Deutsch, W.J.; Serne, R.J.

1983-05-01

When uranium is mined using in-situ leach techniques, the chemical quality of the ground water in the ore-zone aquifer is affected. This could lead to long-term degradation of the ground water if restoration techniques are not applied after the leaching is completed. Pacific Northwest Laboratory (PNL), is conducting an NRC-sponsored research project on natural restoration and induced-restoration techniques. Laboratory studies were designed to evaluate the ability of the natural system (ore-zone sediments and groundwater) to mitigate the effects of mining on aquifer chemistry. Using batch and flow-through column experiments (performed with lixiviant (leaching solution) and sediments from the reduced zone of an ore-zone aquifer), we found that the natural system can lower uranium and bicarbonate concentrations in solutions and reduce the lixiviant redox potential (Eh). The change in redox potential could cause some of the contaminants that were dissolved during the uranium leaching operation to precipitate, thereby lowering their solution concentration. The concentrations of other species such as calcium, potassium, and sulfate increased, possibly as a result of mineral dissolution and ion exchange. In this paper, we describe the experimentally determined mobility of contaminants after in-situ leach mining, and discuss the possible chemical process affecting mobility.

A complete remediation process for a uranium-contaminated site and application to other sites

International Nuclear Information System (INIS)

Mason, C.F.V.; Lu, N.; Kitten, H.D.; Williams, M.; Turney, W.R.J.R.

1998-01-01

During the summer of 1996 the authors were able to test, at the pilot scale, the concept of leaching uranium (U) from contaminated soils. The results of this pilot scale operation showed that the system they previously had developed at the laboratory scale is applicable at the pilot scale. The paper discusses these results, together with laboratory scale results using soil from the Fernald Environmental Management Project (FEMP), Ohio. These FEMP results show how, with suitable adaptations, the process is widely applicable to other sites. The purpose of this paper is to describe results that demonstrate remediation of uranium-contaminated soils may be accomplished through a leach scheme using sodium bicarbonate

A complete remediation process for a uranium-contaminated site and application to other sites

Energy Technology Data Exchange (ETDEWEB)

Mason, C.F.V.; Lu, N.; Kitten, H.D.; Williams, M.; Turney, W.R.J.R.

1998-12-31

During the summer of 1996 the authors were able to test, at the pilot scale, the concept of leaching uranium (U) from contaminated soils. The results of this pilot scale operation showed that the system they previously had developed at the laboratory scale is applicable at the pilot scale. The paper discusses these results, together with laboratory scale results using soil from the Fernald Environmental Management Project (FEMP), Ohio. These FEMP results show how, with suitable adaptations, the process is widely applicable to other sites. The purpose of this paper is to describe results that demonstrate remediation of uranium-contaminated soils may be accomplished through a leach scheme using sodium bicarbonate.

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Lakeview, Oregon. Revision 1

International Nuclear Information System (INIS)

1995-12-01

Surface cleanup at the Uranium Mill Tailings Remedial Action (UMTRA) Project site near Lakeview, Oregon was completed in 1989. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Lakeview, Oregon. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-12-01

Surface cleanup at the Uranium Mill Tailings Remedial Action (UMTRA) Project site near Lakeview, Oregon was completed in 1989. The Ground Water Project evaluates the nature and extent of ground water contamination that resulted from the uranium ore processing activities. The Ground Water Project is in its beginning stages. Human health may be at risk from exposure to ground water contaminated by uranium ore processing. Exposure could occur by drinking water pumped out of a hypothetical well drilled in the contaminated areas. Ecological risks to plants or animals may result from exposure to surface water and sediment that have received contaminated ground water. A risk assessment describes a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the ecological environment may be exposed, and the health or ecological effects that could result from that exposure. This risk assessment is a site-specific document that will be used to evaluate current and potential future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will determine whether any action is needed to protect human health or the ecological environment.

Transport and degradation of contaminants in the vadose zone

NARCIS (Netherlands)

Schotanus, D.

2013-01-01

Leaching of contaminants from the vadose zone to the groundwater depends on the soil properties and the infiltration rate. In this thesis, organic degradable contaminants were studied, such as de-icing chemicals (consisting of propylene glycol, PG) and pesticides. Heterogeneous soil properties

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Falls City, Texas: Revision 1

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

This baseline risk assessment of ground water contamination of the uranium mill tailings site near Falls City, Texas, evaluates potential impact to public health and the environment resulting from ground water contamination at the former Susquehanna Western, Inc. (SWI), uranium mill processing site. This document fulfills the following objectives: determine if the site presents immediate or potential future health risks, determine the need for interim institutional controls, serve as a key input to project planning and prioritization, and recommend future data collection efforts to more fully characterize risk. The Uranium Mill Tailings Remedial Action (UMTRA) Project has begun its evaluation of ground water contamination at the Falls City site. This risk assessment is one of the first documents specific to this site for the Ground Water Project. The first step is to evaluate ground water data collected from monitor wells at or near the site. Evaluation of these data show the main contaminants in the Dilworth ground water are cadmium, cobalt, fluoride, iron, nickel, sulfate, and uranium. The data also show high levels of arsenic and manganese occur naturally in some areas.

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Falls City, Texas: Revision 1

International Nuclear Information System (INIS)

1994-09-01

This baseline risk assessment of ground water contamination of the uranium mill tailings site near Falls City, Texas, evaluates potential impact to public health and the environment resulting from ground water contamination at the former Susquehanna Western, Inc. (SWI), uranium mill processing site. This document fulfills the following objectives: determine if the site presents immediate or potential future health risks, determine the need for interim institutional controls, serve as a key input to project planning and prioritization, and recommend future data collection efforts to more fully characterize risk. The Uranium Mill Tailings Remedial Action (UMTRA) Project has begun its evaluation of ground water contamination at the Falls City site. This risk assessment is one of the first documents specific to this site for the Ground Water Project. The first step is to evaluate ground water data collected from monitor wells at or near the site. Evaluation of these data show the main contaminants in the Dilworth ground water are cadmium, cobalt, fluoride, iron, nickel, sulfate, and uranium. The data also show high levels of arsenic and manganese occur naturally in some areas

Experimental Plan: Uranium Stabilization Through Polyphosphate Injection 300 Area Uranium Plume Treatability Demonstration Project

Energy Technology Data Exchange (ETDEWEB)

Wellman, Dawn M.; Fruchter, Jonathan S.; Vermeul, Vince R.

2006-09-20

This Test Plan describes a laboratory-testing program to be performed at Pacific Northwest National Laboratory (PNNL) in support of the 300-FF-5 Feasibility Study (FS). The objective of the proposed treatability test is to evaluate the efficacy of using polyphosphate injections to treat uranium contaminated groundwater in situ. This study will be used to: (1) Develop implementation cost estimates; (2) Identify implementation challenges; and (3) Investigate the technology's ability to meet remedial objectives These activities will be conducted in parallel with a limited field investigation, which is currently underway to more accurately define the vertical extent of uranium in the vadose zone, and in the capillary fringe zone laterally throughout the plume. The treatability test will establish the viability of the method and, along with characterization data from the limited field investigation, will provide the means for determining how best to implement the technology in the field. By conducting the treatability work in parallel with the ongoing Limited Field Investigation, the resulting Feasibility Study (FS) will provide proven, site-specific information for evaluating polyphosphate addition and selecting a suitable remediation strategy for the uranium plume within the FS time frame at an overall cost savings.

Microbial bioremediation of Uranium: an overview

International Nuclear Information System (INIS)

Acharya, Celin

2015-01-01

Uranium contamination is a worldwide problem. Preventing uranium contamination in the environment is quite challenging and requires a thorough understanding of the microbiological, ecological and biogeochemical features of the contaminated sites. Bioremediation of uranium is largely dependent on reducing its bioavailability in the environment. In situ bioremediation of uranium by microbial processes has been shown to be effective for immobilizing uranium in contaminated sites. Such microbial processes are important components of biogeochemical cycles and regulate the mobility and fate of uranium in the environment. It is therefore vital to advance our understanding of the uranium-microbe interactions to develop suitable bioremediation strategies for uranium contaminated sites. This article focuses on the fundamental mechanisms adopted by various microbes to mitigate uranium toxicity which could be utilized for developing various approaches for uranium bioremediation. (author)

Metabolomics identifies a biological response to chronic low-dose natural uranium contamination in urine samples.

Science.gov (United States)

Grison, Stéphane; Favé, Gaëlle; Maillot, Matthieu; Manens, Line; Delissen, Olivia; Blanchardon, Eric; Banzet, Nathalie; Defoort, Catherine; Bott, Romain; Dublineau, Isabelle; Aigueperse, Jocelyne; Gourmelon, Patrick; Martin, Jean-Charles; Souidi, Maâmar

2013-01-01

Because uranium is a natural element present in the earth's crust, the population may be chronically exposed to low doses of it through drinking water. Additionally, the military and civil uses of uranium can also lead to environmental dispersion that can result in high or low doses of acute or chronic exposure. Recent experimental data suggest this might lead to relatively innocuous biological reactions. The aim of this study was to assess the biological changes in rats caused by ingestion of natural uranium in drinking water with a mean daily intake of 2.7 mg/kg for 9 months and to identify potential biomarkers related to such a contamination. Subsequently, we observed no pathology and standard clinical tests were unable to distinguish between treated and untreated animals. Conversely, LC-MS metabolomics identified urine as an appropriate biofluid for discriminating the experimental groups. Of the 1,376 features detected in urine, the most discriminant were metabolites involved in tryptophan, nicotinate, and nicotinamide metabolic pathways. In particular, N -methylnicotinamide, which was found at a level seven times higher in untreated than in contaminated rats, had the greatest discriminating power. These novel results establish a proof of principle for using metabolomics to address chronic low-dose uranium contamination. They open interesting perspectives for understanding the underlying biological mechanisms and designing a diagnostic test of exposure.

The dendroanalysis of oak trees as a method of biomonitoring past and recent contamination in an area influenced by uranium mining.

Science.gov (United States)

Märten, Arno; Berger, Dietrich; Köhler, Mirko; Merten, Dirk

2015-12-01

We reconstructed the contamination history of an area influenced by 40 years of uranium mining and subsequent remediation actions using dendroanalysis (i.e., the determination of the elemental content of tree rings). The uranium content in the tree rings of four individual oak trees (Quercus sp.) was determined by laser ablation with inductively coupled plasma mass spectrometry (LA-ICP-MS). This technique allows the investigation of trace metals in solid samples with a spatial resolution of 250 μm and a detection limit below 0.01 μg/g for uranium. The investigations show that in three of the four oaks sampled, there were temporally similar uranium concentrations. These were approximately 2 orders of magnitude higher (0.15 to 0.4 μg/g) than those from before the period of active mining (concentrations below 0.01 μg/g). After the mining was terminated and the area was restored, the uranium contents in the wood decreased by approximately 1 order of magnitude. The similar radial uranium distribution patterns of the three trees were confirmed by correlation analysis. In combination with the results of soil analyses, it was determined that there was a heterogeneous contamination in the forest investigated. This could be confirmed by pre-remediation soil uranium contents from literature. The uranium contents in the tree rings of the oaks investigated reflect the contamination history of the study area. This study demonstrates that the dendrochemical analysis of oak tree rings is a suitable technique for investigating past and recent uranium contamination in mining areas.

Uranium biomineralization by a metal resistant Pseudomonas aeruginosa strain isolated from contaminated mine waste

Energy Technology Data Exchange (ETDEWEB)

Choudhary, Sangeeta [Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302 (India); Sar, Pinaki, E-mail: sarpinaki@yahoo.com [Department of Biotechnology, Indian Institute of Technology, Kharagpur 721302 (India)

2011-02-15

Uranium biomineralization by a metal-resistant Pseudomonas aeruginosa strain isolated from uranium mine waste was characterized for its potential in bioremediation. Uranium resistance, its cellular localization and chemical nature of uranium-bacteria interaction were elucidated. Survival and uranium biomineralization from mine water were investigated using microcosm experiments. The selected bacterium showed U resistance and accumulation (maximum of 275 mg U g{sup -1} cell dry wt.) following incubation in 100 mg U L{sup -1}, pH 4.0, for 6 h. Transmission electron microscopy and X-ray diffraction analyses revealed that bioaccumulated uranium was deposited within the cell envelope as needle shaped U-phosphate compounds that attain crystallinity only at pH 4.0. A synergistic involvement of deprotonated phosphate and carboxyl moieties in facilitating bioprecipitation of uranium was evident from FTIR analysis. Based on these findings we attribute the localized U sequestration by this bacterium as innocuous complex to its possible mechanism of uranium resistance. Microcosm data confirmed that the strain can remove soluble uranium (99%) and sequester it as U oxide and phosphate minerals while maintaining its viability. The study showed that indigenous bacteria from contaminated site that can survive uranium and other heavy metal toxicity and sequester soluble uranium as biominerals could play important role in uranium bioremediation.

Elimination of natural uranium and 226Ra from contaminated waters by rhizofiltration using Helianthus annuus L

International Nuclear Information System (INIS)

Vera Tome, F.; Blanco Rodriguez, P.; Lozano, J.C.

2008-01-01

The elimination of natural uranium and 226 Ra from contaminated waters by rhizofiltration was tested using Helianthus annuus L. (sunflower) seedlings growing in a hydroponic medium. Different experiments were designed to determine the optimum age of the seedlings for the remediation process, and also to study the principal way in which the radionuclides are removed from the solution by the sunflower roots. In every trial a precipitate appeared which contained a major fraction of the natural uranium and 226 Ra. The results indicated that the seedlings themselves induced the formation of this precipitate. When four-week-old seedlings were exposed to contaminated water, a period of only 2 days was sufficient to remove the natural uranium and 226 Ra from the solution: about 50% of the natural uranium and 70% of the 226 Ra were fixed in the roots, and essentially the rest was found in the precipitate, with only very small percentages fixed in the shoots and left in solution

The selection of hyperaccumulators for phytoremediation of uranium-contaminated soils and their uranium-accumulating characters

International Nuclear Information System (INIS)

Tang Li; Ren Yamin; Xu Jun; Yao Zhongwei; Xia Chuanqin; Bo Yun; Deng Dachao

2009-01-01

A pot experiment was conducted to investigate the possibility for phytoremediation of U-contaminated soils. The plants of cruciferae (8 species), malvaceae or compositae were planted for 55 days in the U-contaminated soils (100 mg·kg -1 ). The samples were analyzed using an inductively-coupled plasma atomic emission spectrometer (ICP-AES). The results showed that U concentration was the highest in shoots of Chinese mustard (var.Texuanzhacai, 1115 mg·kg -1 ), the highest U removal from U-contaminated soils to plants occurred in the shoots of Artemisia argyi(1113 μg per pot). For the Chinese mustard (var.Paoqingcai, var. Texuanzhacai), uranium concentration in shoots was higher than in roots, and bioaccumulation factors (BFs) and transfer factors (TFs) were more than one. They showed better suitability for phytoremediation of U than other plants due to their high U accumulation in the aboveground tissues. (authors)

Baseline risk assessment for groundwater contamination at the uranium mill tailings site near Monument Valley, Arizona. Draft

Energy Technology Data Exchange (ETDEWEB)

1993-09-01

This baseline risk assessment evaluates potential impact to public health or the environment resulting from groundwater contamination at the former uranium mill processing site near Monument Valley, Arizona. The tailings and other contaminated material at this site are being relocated and stabilized in a disposal cell at Mexican Hat, Utah, through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The tailings removal is planned for completion by spring 1994. After the tailings are removed, groundwater contamination at the site will continue to be evaluated. This risk assessment is the first document specific to this site for the Groundwater Project. It will be used to assist in determining what remedial action is needed for contaminated groundwater at the site.

Unintentional contaminant transfer from groundwater to the vadose zone during source zone remediation of volatile organic compounds.

Science.gov (United States)

Chong, Andrea D; Mayer, K Ulrich

2017-09-01

Historical heavy use of chlorinated solvents in conjunction with improper disposal practices and accidental releases has resulted in widespread contamination of soils and groundwater in North America and worldwide. As a result, remediation of chlorinated solvents is required at many sites. For source zone treatment, common remediation strategies include in-situ chemical oxidation (ISCO) using potassium or sodium permanganate, and the enhancement of biodegradation by primary substrate addition. It is well known that these remediation methods tend to generate gas (carbon dioxide (CO 2 ) in the case of ISCO using permanganate, CO 2 and methane (CH 4 ) in the case of bioremediation). Vigorous gas generation in the presence of chlorinated solvents, which are categorized as volatile organic contaminants (VOCs), may cause gas exsolution, ebullition and stripping of the contaminants from the treatment zone. This process may lead to unintentional 'compartment transfer', whereby VOCs are transported away from the contaminated zone into overlying clean sediments and into the vadose zone. To this extent, benchtop column experiments were conducted to quantify the effect of gas generation during remediation of the common chlorinated solvent trichloroethylene (TCE/C 2 Cl 3 H). Both ISCO and enhanced bioremediation were considered as treatment methods. Results show that gas exsolution and ebullition occurs for both remediation technologies. Facilitated by ebullition, TCE was transported from the source zone into overlying clean groundwater and was subsequently released into the column headspace. For the case of enhanced bioremediation, the intermediate degradation product vinyl chloride (VC) was also stripped from the treatment zone. The concentrations measured in the headspace of the columns (TCE ∼300ppm in the ISCO column, TCE ∼500ppm and VC ∼1380ppm in the bioremediation column) indicate that substantial transfer of VOCs to the vadose zone is possible. These findings

Process for producing uranium oxide rich compositions from uranium hexafluoride

International Nuclear Information System (INIS)

DeHollander, W.R.; Fenimore, C.P.

1978-01-01

Conversion of gaseous uranium hexafluoride to a uranium dioxide rich composition in the presence of an active flame in a reactor defining a reaction zone is achieved by separately introducing a first gaseous reactant comprising a mixture of uranium hexafluoride and a reducing carrier gas, and a second gaseous reactant comprising an oxygen-containing gas. The reactants are separated by a shielding gas as they are introduced to the reaction zone. The shielding gas temporarily separates the gaseous reactants and temporarily prevents substantial mixing and reacting of the gaseous reactants. The flame occurring in the reaction zone is maintained away from contact with the inlet introducing the mixture to the reaction zone. After suitable treatment, the uranium dioxide rich composition is capable of being fabricated into bodies of desired configuration for loading into nuclear fuel rods. Alternatively, an oxygen-containing gas as a third gaseous reactant is introduced when the uranium hexafluoride conversion to the uranium dioxide rich composition is substantially complete. This results in oxidizing the uranium dioxide rich composition to a higher oxide of uranium with conversion of any residual reducing gas to its oxidized form

Baseline risk assessment for groundwater contamination at the uranium mill tailings site, Gunnison, Colorado

International Nuclear Information System (INIS)

1990-11-01

The Gunnison Baseline Risk Assessment for Groundwater Contamination at the Uranium Mill Tailings Site was performed to determine if long-term use of groundwater from domestic wells near the site has a potential for adverse health effects. The risk assessment was based on the results of sampling domestic wells during 1989--1990. A risk assessment evaluates health risks by comparing the amount of a contaminant taken in by a person with the amount of the contaminant that may be toxic. The Gunnison Risk Assessment used high intake values to estimate the maximum levels a person might be exposed to. The results of the risk assessment are divided into cancer (carcinogenic) risks and non-carcinogenic risks. Five key contaminants were evaluated for adverse health risks: uranium, manganese, lead antimony, and cadmium. Due to the potential health risks and the unavoidable uncertainties associated with limited groundwater and toxicity data, it is prudent public health policy to provide a permanent alternate water supply. Additionally, providing a permanent alternate water supply is cost-effective compared to long-term routine monitoring

VADOSE ZONE STUDIES AT AN INDUSTRIAL CONTAMINATED SITE: THE VADOSE ZONE MONITORING SYSTEM AND CROSS-HOLE GEOPHYSICS

OpenAIRE

Fernandez de Vera, Natalia; Beaujean, Jean; Jamin, Pierre; Nguyen, Frédéric; Dahan, Ofer; Vanclooster, Marnik; Brouyère, Serge

2014-01-01

In situ vadose zone characterization is essential to improve risk characterization and remediation measures for soil and groundwater contamination. However, most available technologies have been developed in the context of agricultural soils. Most of these methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. In addition, they are applicable only in the first meters of soils, leaving deeper vadose zones with lack of informatio...

Development of complex electrokinetic decontamination method for soil contaminated with uranium

International Nuclear Information System (INIS)

Kim, Gye-Nam; Kim, Seung-Soo; Park, Hye-Min; Kim, Wan-Suk; Moon, Jei-Kwon; Hyeon, Jay-Hyeok

2012-01-01

520L complex electrokinetic soil decontamination equipment was manufactured to clean up uranium contaminated soils from Korean nuclear facilities. To remove uranium at more than 95% from the radioactive soil through soil washing and electrokinetic technology, decontamination experiments were carried out. To reduce the generation of large quantities of metal oxides in cathode, a pH controller is used to control the pH of the electrolyte waste solution between 0.5 and 1 for the formation of UO 2+ . More than 80% metal oxides were removed through pre-washing, an electrolyte waste solution was circulated by a pump, and a metal oxide separator filtered the metal oxide particles. 80–85% of the uranium was removed from the soil by soil washing as part of the pre-treatment. When the initial uranium concentration of the soil was 21.7 Bq/g, the required electrokinetic decontamination time was 25 days. When the initial concentration of 238 U in the soil was higher, a longer decontamination time was needed, but the removal rate of 238 U from the soil was higher.

The technique for determination of surface contamination by uranium on U3Si2-Al plate-type fuel elements

International Nuclear Information System (INIS)

Li Shulan; He Fengqi; Wang Qingheng; Han Jingquan

1993-04-01

The NDT method for determining the surface contamination by uranium on U 3 Si 2 -Al plate-type fuel elements, the process of standard specimen preparation and the graduation curve are described. The measurement results of U 3 Si 2 -Al plate-type fuel elements show that the alpha counting method to measure the surface contamination by uranium on fuel plate is more reliable. The UB-1 type surface contamination meter, which was recently developed, has many advantages such as high sensitivity to determine the uranium pollution, short time in measuring, convenience for operation, and the minimum detectable amount of uranium is 5 x 10 -10 g/cm 2 . The measuring device is controlled by a microcomputer. Besides data acquisition and processing, it has functions of statistics, output data on terminal or to printer and alarm. The procedures of measurement are fully automatic. All of these will meet the measuring needs in batch process

Geochemical zoning around the McClean uranium deposits, Saskatchewan, Canada

International Nuclear Information System (INIS)

Golightly, J.P.; Brummer, J.J.; Saracoglu

1983-01-01

The uranium mineralization of the McClean deposits can be described as belonging to two different facies; a more reduced sulphide-arsenide facies and a more oxidized hematite-'bleached' facies, superimposed on any one of three host rocks. The trace metals can be grouped according to their redox behaviour. Vanadium, Mo and U, occurring as oxides, form one group while Ni, Co, Zn, Cu and As, occurring as sulphides and/or arsenides, form intermediate and most reduced groups, respectively. The ratio of oxidized to reduced minerals can be represented by the ratio of U/Ni. This ratio can be used to estimate the variation of redox potential in the deposit at the time of deposition or alteration. A generalized Eh-pH diagram is used to qualitatively describe the significance of each mineral facies. The U/Ni ratio of the transition between the hematite and 'bleached' facies increases upwards. The phase diagram suggests that a possible cause is an upward decrease in pH and increase in Eh. Uranium analysis of the drill core shows that there is little movement of U into the overlying sandstones from basement rocks and regolith that contain no uranium deposits. Uranium in the Athabasca sandstone from these areas averages less than 1 ppm. However, where uranium zones have been found in the basement rocks, regolith and lower Athabasca sandstone, U values greater than 2-3 ppm consistently occur in the overlying sandstones at or near surface. Results suggest that target areas containing deeply buried uranium deposits could be defined by U analyses of the Athabasca sandstone from quite widely spaced holes of limited depth. (Auth.)

Conceptual Models for Migration of Key Groundwater Contaminants Through the Vadose Zone and Into the Upper Unconfined Aquifer Below the B-Complex

Energy Technology Data Exchange (ETDEWEB)

Serne, R. Jeffrey; Bjornstad, Bruce N.; Keller, Jason M.; Thorne, Paul D.; Lanigan, David C.; Christensen, J. N.; Thomas, Gregory S.

2010-07-01

The B-Complex contains 3 major crib and trench disposal sites and 3 SST farms that have released nearly 346 mega-liters of waste liquids containing the following high groundwater risk drivers: ~14,000 kg of CN, 29,000 kg of Cr, 12,000 kg of U and 145 Ci of Tc-99. After a thorough review of available vadose zone sediment and pore water, groundwater plume, field gamma logging, field electrical resistivity studies, we developed conceptual models for which facilities have been the significant sources of the contaminants in the groundwater and estimated the masses of these contaminants remaining in the vadose zone and currently present in the groundwater in comparison to the totals released. This allowed us to make mass balance calculations on how consistent our knowledge is on the current deep vadose zone and groundwater distribution of contaminants. Strengths and weaknesses of the conceptual models are discussed as well as implications on future groundwater and deep vadose zone remediation alternatives. Our hypothesized conceptual models attribute the source of all of the cyanide and most of the Tc-99 currently in the groundwater to the BY cribs. The source of the uranium is the BX-102 tank overfill event and the source of most of the chromium is the B-7-A&B and B-8 cribs. Our mass balance estimates suggest that there are much larger masses of U, CN, and Tc remaining in the deep vadose zone within ~20 ft of the water table than is currently in the groundwater plumes below the B-Complex. This hypothesis needs to be carefully considered before future remediation efforts are chosen. The masses of these groundwater risk drivers in the the groundwater plumes have been increasing over the last decade and the groundwater plumes are migrating to the northwest towards the Gable Gap. The groundwater flow rate appears to flucuate in response to seasonal changes in hydraulic gradient. The flux of contaminants out of the deep vadose zone from the three proposed sources also

Chlorite in alteration zone of uranium deposits No.201, No.325 and No.706

Energy Technology Data Exchange (ETDEWEB)

Jianguo, He; Jiashu, Rong; Yuxian, Mao; Jianzhong, Li; Changliang, Wang; Mingyue, Feng [Beijing Research Inst. of Uranium Geology, Beijing (China); Minqiang, Zhu; Minghui, Rao [East China Inst. of T echnology, Fuzhou (China)

2008-09-15

According to mineralogical examination and electron microprobe data analysis, post-biotite chlorite and spheluritic chlorite are two forms of chlorites in the alteration zone of granite-type uranium deposits No.325 and No.706. As post-biotite chlorite is substituted for spheluritic chlorite, during the substitution, some Fe are released and Mg replace in, which results in the further hematization in rock. This is probably one of the reasons that red color occurs in sodium metasomatic alteration zone. The chlorites in uranium deposits No.201 and No.325 are brunsvigite and ripidolite. Most of the chlorites in uranium deposit No.706 are pycnochlorite and diabantite, while a few are brunsvigites. A new finding shows that the chlorite variety is determined mainly by {Sigma}FeO and MgO ratio of primary rock and is independent of alteration characteristic (acidic alteration or alkalic alteration). The proportion of Mg hydroxyl and Al hydroxyl in the unit-cell of chlorite may cause spectrum difference of diagnostic absorptive valley position and depth at 2259-2262 nm and 2348-2359 nm. (authors)

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Riverton, Wyoming. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the Surface Project and the Ground Water Project. At the UMTRA Project site near Riverton, Wyoming, Surface Project cleanup occurred from 1988 to 1990. Tailings and radioactively contaminated soils and materials were taken from the Riverton site to a disposal cell in the Gas Hills area, about 60 road miles (100 kilometers) to the east. The surface cleanup reduces radon and other radiation emissions and minimizes further ground water contamination. The UMTRA Project`s second phase, the Ground Water Project, will evaluate the nature and extent of ground water contamination at the Riverton site that has resulted from the uranium ore processing activities. Such evaluations are used at each site to determine a strategy for complying with UMTRA ground water standards established by the US Environmental Protection Agency (EPA) and if human health risks could result from exposure to ground water contaminated by uranium ore processing. Exposure could hypothetically occur if drinking water were pumped from a well drilled in an area where ground water contamination might have occurred. Human health and environmental risks may also result if people, plants, or animals are exposed to surface water that has mixed with contaminated ground water.

Baseline risk assessment of ground water contamination at the uranium mill tailings site near Riverton, Wyoming. Revision 1

International Nuclear Information System (INIS)

1995-09-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of two phases: the Surface Project and the Ground Water Project. At the UMTRA Project site near Riverton, Wyoming, Surface Project cleanup occurred from 1988 to 1990. Tailings and radioactively contaminated soils and materials were taken from the Riverton site to a disposal cell in the Gas Hills area, about 60 road miles (100 kilometers) to the east. The surface cleanup reduces radon and other radiation emissions and minimizes further ground water contamination. The UMTRA Project's second phase, the Ground Water Project, will evaluate the nature and extent of ground water contamination at the Riverton site that has resulted from the uranium ore processing activities. Such evaluations are used at each site to determine a strategy for complying with UMTRA ground water standards established by the US Environmental Protection Agency (EPA) and if human health risks could result from exposure to ground water contaminated by uranium ore processing. Exposure could hypothetically occur if drinking water were pumped from a well drilled in an area where ground water contamination might have occurred. Human health and environmental risks may also result if people, plants, or animals are exposed to surface water that has mixed with contaminated ground water

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Shiprock, New Mexico. Revision 1

Energy Technology Data Exchange (ETDEWEB)

1994-04-01

This baseline risk assessment at the former uranium mill tailings site near Shiprock, New Mexico, evaluates the potential impact to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an on-site disposal cell in 1986 through the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project. There are no domestic or drinking water wells in the contaminated ground water of the two distinct ground water units: the contaminated ground water in the San Juan River floodplain alluvium below the site and the contaminated ground water in the terrace alluvium area where the disposal cell is located. Because no one is drinking the affected ground water, there are currently no health or environmental risks directly associated with the contaminated ground water. However, there is a potential for humans, domestic animals, and wildlife to the exposed to surface expressions of ground water in the seeps and pools in the area of the San Juan River floodplain below the site. For these reasons, this risk assessment evaluates potential exposure to contaminated surface water and seeps as well as potential future use of contaminated ground water.

Tackling the Challenge of Deep Vadose Zone Remediation at the Hanford Site

Science.gov (United States)

Morse, J. G.; Wellman, D. M.; Gephart, R.

2010-12-01

The Central Plateau of the Hanford Site in Washington State contains some 800 waste disposal sites where 1.7 trillion liters of contaminated water was once discharged into the subsurface. Most of these sites received liquids from the chemical reprocessing of spent uranium fuel to recover plutonium. In addition, 67 single shell tanks have leaked or are suspected to have leaked 3.8 million liters of high alkali and aluminate rich cesium-contaminated liquids into the sediment. Today, this inventory of subsurface contamination contains an estimated 550,000 curies of radioactivity and 150 million kg (165,000 tons) of metals and hazardous chemicals. Radionuclides range from mobile 99Tc to more immobilized 137Cs, 241Am, uranium, and plutonium. A significant fraction of these contaminants likely remain within the deep vadose zone. Plumes of groundwater containing tritium, nitrate, 129I and other contaminants have migrated through the vadose zone and now extend outward from the Central Plateau to the Columbia River. During most of Hanford Site history, subsurface studies focused on groundwater monitoring and characterization to support waste management decisions. Deep vadose zone studies were not a priority because waste practices relied upon that zone to buffer contaminant releases into the underlying aquifer. Remediation of the deep vadose zone is now central to Hanford Site cleanup because these sediments can provide an ongoing source of contamination to the aquifer and therefore to the Columbia River. However, characterization and remediation of the deep vadose zone pose some unique challenges. These include sediment thickness; contaminant depth; coupled geohydrologic, geochemical, and microbial processes controlling contaminant spread; limited availability and effectiveness of traditional characterization tools and cleanup remedies; and predicting contaminant behavior and remediation performance over long time periods and across molecular to field scales. The U

Baseline risk assessment of ground water contamination at the uranium mill tailings sites near Rifle, Colorado. Revision 1

International Nuclear Information System (INIS)

1995-08-01

The US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase 1) and the Ground Water Project (Phase 2). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further ground water contamination. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. Two UMTRA Project sites are near Rifle, Colorado: the Old Rifle site and the New Rifle site. Surface cleanup at the two sites is under way and is scheduled for completion in 1996. The Ground Water Project is in its beginning stages. A risk assessment identifies a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the environment may be exposed, and the health or environmental effects that could result from that exposure. This report is a site-specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. This evaluation and further site characterization will be used to determine if action is needed to protect human health or the environment

Baseline risk assessment of ground water contamination at the uranium mill tailings sites near Rifle, Colorado. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

The US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (Phase 1) and the Ground Water Project (Phase 2). Under the UMTRA Surface Project, tailings, radioactive contaminated soil, equipment, and materials associated with the former uranium ore processing sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further ground water contamination. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. Two UMTRA Project sites are near Rifle, Colorado: the Old Rifle site and the New Rifle site. Surface cleanup at the two sites is under way and is scheduled for completion in 1996. The Ground Water Project is in its beginning stages. A risk assessment identifies a source of contamination, how that contamination reaches people and the environment, the amount of contamination to which people or the environment may be exposed, and the health or environmental effects that could result from that exposure. This report is a site-specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. This evaluation and further site characterization will be used to determine if action is needed to protect human health or the environment.

Uranium biomineralization by a metal resistant Pseudomonas aeruginosa strain isolated from contaminated mine waste.

Science.gov (United States)

Choudhary, Sangeeta; Sar, Pinaki

2011-02-15

Uranium biomineralization by a metal-resistant Pseudomonas aeruginosa strain isolated from uranium mine waste was characterized for its potential in bioremediation. Uranium resistance, its cellular localization and chemical nature of uranium-bacteria interaction were elucidated. Survival and uranium biomineralization from mine water were investigated using microcosm experiments. The selected bacterium showed U resistance and accumulation (maximum of 275 mg U g(-1)cell dry wt.) following incubation in 100 mg U L(-1), pH 4.0, for 6 h. Transmission electron microscopy and X-ray diffraction analyses revealed that bioaccumulated uranium was deposited within the cell envelope as needle shaped U-phosphate compounds that attain crystallinity only at pH 4.0. A synergistic involvement of deprotonated phosphate and carboxyl moieties in facilitating bioprecipitation of uranium was evident from FTIR analysis. Based on these findings we attribute the localized U sequestration by this bacterium as innocuous complex to its possible mechanism of uranium resistance. Microcosm data confirmed that the strain can remove soluble uranium (99%) and sequester it as U oxide and phosphate minerals while maintaining its viability. The study showed that indigenous bacteria from contaminated site that can survive uranium and other heavy metal toxicity and sequester soluble uranium as biominerals could play important role in uranium bioremediation. Copyright © 2010 Elsevier B.V. All rights reserved.

TECHNICAL BASIS FOR EVALUATING SURFACE BARRIERS TO PROTECT GROUNDWATER FROM DEEP VADOSE ZONE CONTAMINATION

International Nuclear Information System (INIS)

Fayer, J.M.; Freedman, V.L.; Ward, A.L.; Chronister, G.B.

2010-01-01

The U.S. DOE and its predecessors released nearly 2 trillion liters (450 billion gallons) of contaminated liquid into the vadose zone at the Hanford Site. Some of the contaminants currently reside in the deeper parts of the vadose zone where they are much less accessible to characterization, monitoring, and typical remediation activities. The DOE Richland Operations Office (DOE-RL) prepared a treatability test plan in 2008 to examine remediation options for addressing contaminants in the deep vadose zone; one of the technologies identified was surface barriers (also known as engineered barriers, covers, and caps). In the typical configuration, the contaminants are located relatively close to the surface, generally within 15 m, and thus they are close to the base of the surface barrier. The proximity of the surface barrier under these conditions yielded few concerns about the effectiveness of the barrier at depth, particularly for cases in which the contaminants were in a lined facility. At Hanford, however, some unlined sites have contaminants located well below depths of 15 m. The issue raised about these sites is the degree of effectiveness of a surface barrier in isolating contaminants in the deep vadose zone. Previous studies by Hanford Site and PNNL researchers suggest that surface barriers have the potential to provide a significant degree of isolation of deep vadose zone contaminants. The studies show that the actual degree of isolation is site-specific and depends on many factors, including recharge rates, barrier size, depth of contaminants, geohydrologic properties ofthe sediments, and the geochemical interactions between the contaminants and the sediments. After the DOE-RL treatability test plan was published, Pacific Northwest National Laboratory was contracted to review the information available to support surface barrier evaluation for the deep vadose zone, identify gaps in the information and outcomes necessary to fill the data gaps, and outline

Microbial links between sulfate reduction and metal retention in uranium- and heavy metal-contaminated soil.

Science.gov (United States)

Sitte, Jana; Akob, Denise M; Kaufmann, Christian; Finster, Kai; Banerjee, Dipanjan; Burkhardt, Eva-Maria; Kostka, Joel E; Scheinost, Andreas C; Büchel, Georg; Küsel, Kirsten

2010-05-01

Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB in groundwater-influenced soils from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany. In situ activity of SRB, measured by the (35)SO(4)(2-) radiotracer method, was restricted to reduced soil horizons with rates of metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that approximately 80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based dsrAB clone libraries were dominated by sequences affiliated with members of the Desulfobacterales but also the Desulfovibrionales, Syntrophobacteraceae, and Clostridiales. [(13)C]acetate- and [(13)C]lactate-biostimulated soil microcosms were dominated by sulfate and Fe(III) reduction. These processes were associated with enrichment of SRB and Geobacteraceae; enriched SRB were closely related to organisms detected in soils by using the dsrAB marker. Concentrations of soluble nickel, cobalt, and occasionally zinc declined uranium increased in carbon-amended treatments, reaching metal attenuation and (ii) the fate of uranium mobility is not predictable and may lead to downstream contamination of adjacent ecosystems.

Development of a pharmaceutical form containing calixarene molecules for the treatment of intact or injured skin contaminated by uranium

International Nuclear Information System (INIS)

Spagnul, A.

2009-11-01

The first objective of this research thesis was to develop a formulation containing a tricarboxylic calixarene for cutaneous application for the local treatment of skin contamination by uranium. A second objective is to assess the efficiency of a calixarene nano-emulsion for such a treatment. In a first part, the author proposes an overview of risks associated with skin contamination by uranium, and of current treatments and treatments under development. In the second part, the author presents the oil-in-water-type nano-emulsion, reports an in vitro assessment of the decontamination efficiency of the calixarene nano-emulsion, reports an in vivo assessment of this efficiency (on pig ear skin explants contaminated by uranium), and presents the main publications and a patent request related to this research work

Water treatment strategy for underground and surface waters in order to reduce the hydro-network contamination due to close out of a uranium mining area in Romania

International Nuclear Information System (INIS)

Georgescu, D.; Radulescu, C.

1999-01-01

Under the present circumstances, in correlation with the national nuclear program and strategy, it is foreseen to stop the exploitation activities in two important uranium mining areas from Romania. This close-out action is involving a number of technical decisions for environmental restoration. Reduction of waters radioactive contamination in these zones, both during the operating period and after the closeout period, is one of the main components of the environment rehabilitation strategy. In this paper there are presented the today situation and the program foreseen for ground and surface water treatment at an uranium mining unit situated in the SW side of Romania, program based on the results of our own research carried out to decrease the content of pollutant radioactive elements. (author)

Changes in Uranium Speciation through a Depth Sequence of Contaminated Hanford Sediments

International Nuclear Information System (INIS)

Catalano, Jeffrey G.; McKinley, James P.; Zachara, John M.; Heald, Steve M.; Smith, Steven C.; Brown, Gordon E.

2006-01-01

The disposal of basic sodium-aluminate and acidic U(VI)-Cu(II) wastes into the now-dry North and South 300 A Process Ponds at the Hanford site resulted in U(VI) groundwater plume. To gain insight into the geochemical processes that occurred during waste disposal and that will affect the future fate and transport of this uranium plume, the solid-phase speciation of uranium in a depth sequence from the base of the North Process Pond through the vadose zone to the water table was investigated using electron microprobe measurements and x-ray absorption fine structure spectroscopy. Uranium in sediments from the base of the pond was predominantly coprecipitated with calcite. From ∼2 m below the pond base to the water table uranium occurred dominantly in a sorbed form, likely on the surface aluminosilicate clay minerals. The presence of a U(VI)-phosphate phase was also observed in this region, but it only occurred as a major uranium species at one depth. The initial sequestration of U(VI) in these sediments likely occurred through coprecipitation with calcite as conditions did not favor adsorption. As the calcite-bearing pond sediments have been removed as part of a remediation effort, future uranium fate and transport will likely be controlled primarily by adsorption/desorption phenomena

Quantifying and Predicting Reactive Transport of Uranium in Waste Plumes: Are Colloids and Nanoparticles Important?

International Nuclear Information System (INIS)

Jiamin Wan; Tetsu Tokunaga; Carl Steefel; Peter Burns

2006-01-01

The Hanford Site is the DOE's largest legacy waste site, with uranium (U) from plutonium processing being a major contaminant in its subsurface. Accidental release of highly concentrated high-level wastes left large quantities of U in the vadose zone under tank farms. The U contamination has been found in groundwater beneath the tank farms, indicating U is mobile

Development of the fission fragment track registration technique for the determination of the uranium contamination

International Nuclear Information System (INIS)

Tanaka, E.M.

1979-01-01

The Fission Fragment Track Registration Technique is developed to measure the uranium concentration about microgram of uranium per litre of liquid samples. The drying method of drops on the detector (Makrofol KG) and a special sampling procedure to avoid the cumbersome high density of tracks formation at the edge of the deposition surface as a 'ring' is adopted. The samples are irradiated by neutrons produced by the IEA-R1 Reactor (thermal neutron flux about 10 12 neutrons/cm 2 .s) inducing the uranium fission. The tracks registered by the fission fragments in the detector are chemically enlarged and counted by an automatic couting system. By this method the uranium concentrations ranging from 0,9 to 7,6 microgram of uranium per litre, can be determined with precisions between 2,7% the greater and 23% to the lower concentration. The uranium concentration measurements in human hair and urine are made showing that this method is very useful to control and detect eventual uranium contamination [pt

Radiation protection of the workers, public and the environment during / after uranium site restoration and clean-up of additional contaminated areas

International Nuclear Information System (INIS)

Aurelian, F.; Georgescu, D.; Popescu, M.

2006-01-01

Full text of publication follows: Beginning with 1950 the uranium mining industry was developed in Romania. Banat region was one of the most important metallogenic zones of the country and its exploitation began on 1962. Between 1988 and 1998 uranium exploitation activity was ceased due to the uranium ore deposits exhaustion. Therefore, between 2000 and 2004 the entire mining zone closure, ecological rehabilitation and decommissioning documentation was conceived. The proposed solutions were elaborated according to the Romanian Environmental and Nuclear Authority concerning the terrain, equipment, devices and buildings unrestricted utilization after the mining site decommissioning and ecological rehabilitation. The radioactive sources (dumps, contaminated soil, and mining waters), radioactive pollution spreading pathways and the affected target groups were identified based on the research studies carried out in order to elaborate the mining area closure, decommissioning and ecological rehabilitation technical project. The closured mining zone map with these elements positions and their radioactive potential, namely the uranium and radium content, gamma radiation and radon concentration is presented. The present paper shows the assessment of the supplementary effective doses received by the population from the critical groups, which are calculated for the following three distinct situations: a) at the moment of uranium ore exploitation activity closure; b) during the closure, decommissioning and rehabilitation workings time; c) after the site rehabilitation and remediation. Each moment is characterized by a map, which presents the radioactivity levels discussed for four distinct scenarios. Each one of these scenarios is characterized and justified for its chosen. For each one of the scenarios there are presented maps with the pollution sources and pathways and there are calculated the public supplementary effective doses before and after site restoration. During the

Elimination of natural uranium and {sup 226}Ra from contaminated waters by rhizofiltration using Helianthus annuus L

Energy Technology Data Exchange (ETDEWEB)

Vera Tome, F. [Departamento de Fisica Aplicada, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain)], E-mail: fvt@unex.es; Blanco Rodriguez, P. [Departamento de Fisica, Facultad de Ciencias, Universidad de Extremadura, 06071 Badajoz (Spain); Lozano, J.C. [Laboratorio de Radiactividad Ambiental, Facultad de Ciencias, Universidad de Salamanca, 37008 Salamanca (Spain)

2008-04-15

The elimination of natural uranium and {sup 226}Ra from contaminated waters by rhizofiltration was tested using Helianthus annuus L. (sunflower) seedlings growing in a hydroponic medium. Different experiments were designed to determine the optimum age of the seedlings for the remediation process, and also to study the principal way in which the radionuclides are removed from the solution by the sunflower roots. In every trial a precipitate appeared which contained a major fraction of the natural uranium and {sup 226}Ra. The results indicated that the seedlings themselves induced the formation of this precipitate. When four-week-old seedlings were exposed to contaminated water, a period of only 2 days was sufficient to remove the natural uranium and {sup 226}Ra from the solution: about 50% of the natural uranium and 70% of the {sup 226}Ra were fixed in the roots, and essentially the rest was found in the precipitate, with only very small percentages fixed in the shoots and left in solution.

Evaluation of Soil Flushing for Application to the Deep Vadose Zone in the Hanford Central Plateau

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Oostrom, Martinus; Zhang, Z. F.; Carroll, Kenneth C.; Schramke, Janet A.; Wietsma, Thomas W.; Tartakovsky, Guzel D.; Gordon, Kathryn A.; Last, George V.

2010-11-01

Soil flushing was included in the Deep Vadose Zone Treatability Test Plan for the Hanford Central Plateau as a technology with the potential to remove contaminants from the vadose zone. Soil flushing operates through the addition of water, and if necessary an appropriate mobilizing agent, to mobilize contaminants and flush them from the vadose zone and into the groundwater where they are subsequently captured by a pump-and-treat system. There are uncertainties associated with applying soil flushing technology to contaminants in the deep vadose zone at the Hanford Central Plateau. The modeling and laboratory efforts reported herein are intended to provide a quantitative assessment of factors that impact water infiltration and contaminant flushing through the vadose zone and into the underlying groundwater. Once in the groundwater, capture of the contaminants would be necessary, but this aspect of implementing soil flushing was not evaluated in this effort. Soil flushing was evaluated primarily with respect to applications for technetium and uranium contaminants in the deep vadose zone of the Hanford Central Plateau.

Former uranium mine-induced effects in caged roach: a multiparametric approach for the evaluation of in situ metal toxicity.

Science.gov (United States)

Gagnaire, Béatrice; Bado-Nilles, Anne; Betoulle, Stéphane; Amara, Rachid; Camilleri, Virginie; Cavalié, Isabelle; Chadili, Edith; Delahaut, Laurence; Kerambrun, Elodie; Orjollet, Daniel; Palluel, Olivier; Sanchez, Wilfried

2015-01-01

To characterize environmental risks linked to former uranium mines in the Limousin region of France, a study was conducted on fish health effects from uranium releases. Two private ponds were compared in this study, one with uranium contamination and one background site, upstream of the mining zone. Roach, Rutilus rutilus, were caged for 28 days in both ponds. Physico-chemical parameters of water and sediments and bioaccumulation of metals in several organs were determined. After 14 and 28 days of caging, immune, oxidative stress, biotransformation, neurotoxicity and physiological parameters were measured. Iron and aluminium were quantified in the water of both sites; however, barium and manganese were only present in the water of the uranium contaminated site. Uranium was present in both sites but at very different concentrations. The sediments from the uranium contaminated site contained high levels of radioactive elements coming from the disintegration chain of uranium. Results of biological parameters indicated stimulation of immune parameters and of oxidative stress and a decrease of AChE in fish caged in the uranium contaminated pond compared to the uranium-free pond. Overall, the results determined roach health status in the context of pollution from poly-metallic mining. The data strengthen our knowledge of the environmental risk assessment associated with radioactive substances in the environment.

In situ effects of metal contamination from former uranium mining sites on the health of the three-spined stickleback (Gasterosteus aculeatus, L.).

Science.gov (United States)

Le Guernic, Antoine; Sanchez, Wilfried; Bado-Nilles, Anne; Palluel, Olivier; Turies, Cyril; Chadili, Edith; Cavalié, Isabelle; Delahaut, Laurence; Adam-Guillermin, Christelle; Porcher, Jean-Marc; Geffard, Alain; Betoulle, Stéphane; Gagnaire, Béatrice

2016-08-01

Human activities have led to increased levels of various pollutants including metals in aquatic ecosystems. Increase of metallic concentrations in aquatic environments represents a potential risk to exposed organisms, including fish. The aim of this study was to characterize the environmental risk to fish health linked to a polymetallic contamination from former uranium mines in France. This contamination is characterized by metals naturally present in the areas (manganese and iron), uranium, and metals (aluminum and barium) added to precipitate uranium and its decay products. Effects from mine releases in two contaminated ponds (Pontabrier for Haute-Vienne Department and Saint-Pierre for Cantal Department) were compared to those assessed at four other ponds outside the influence of mine tailings (two reference ponds/department). In this way, 360 adult three-spined sticklebacks (Gasterosteus aculeatus) were caged for 28 days in these six ponds before biomarker analyses (immune system, antioxidant system, biometry, histology, DNA integrity, etc.). Ponds receiving uranium mine tailings presented higher concentrations of uranium, manganese and aluminum, especially for the Haute-Vienne Department. This uranium contamination could explain the higher bioaccumulation of this metal in fish caged in Pontabrier and Saint-Pierre Ponds. In the same way, many fish biomarkers (antioxidant and immune systems, acetylcholinesterase activity and biometric parameters) were impacted by this environmental exposure to mine tailings. This study shows the interest of caging and the use of a multi-biomarker approach in the study of a complex metallic contamination.

Identification of chemical processes influencing constituent mobility during in-situ uranium leaching

International Nuclear Information System (INIS)

Sherwood, D.R.; Hostetler, C.J.; Deutsch, W.J.

1984-07-01

In-situ leaching of uranium has become a widely accepted method for production of uranium concentrate from ore zones that are too small, too deep, and/or too low in grade to be mined by conventional techniques. One major environmental concern that exists with in-situ leaching of uranium is the possible adverse effects mining might have on regional ground water quality. The leaching solution (lixiviant), which extracts uranium from the ore zone, might also mobilize other potential contaminants (As, Se, Mo, and SO 4 ) associated with uranium ore. Column experiments were performed to investigate the geochemical interactions between a lixiviant and a uranium ore during in-situ leaching and to identify chemical processes that might influence contaminant mobility. The analytical composition data for selected column effluents were used with the MINTEQ code to develop a computerized geochemical model of the system. MINTEQ was used to calculate saturation indices for solid phases based on the composition of the solution. A potential constraint on uranium leaching efficiency appears to be the solubility control of schoepite. Gypsum and powellite solubilities may limit the mobilities of sulfate and molybdenum, respectively. In contrast, the mobilities of arsenic and selenium were not limited by solubility constraints, but were influenced by other chemical interaction between the solution and sediment, perhaps adsorption. Bulk chemical and mineralogical analyses were performed on both the original and leached ores. Using these analyses together with the column effluent data, mass balance calculations were performed on five constituents based on solution chemical analysis and bulk chemical and γ-spectroscopy analysis for the sediment. 6 references, 10 figures, 10 tables

CMI Remedy Selection for HE- and Barium-Contaminated Vadose Zone and Alluvium at LANL

Science.gov (United States)

Hickmott, D.; Reid, K.; Pietz, J.; Ware, D.

2008-12-01

A high explosives (HE) machining building outfall at Los Alamos National Laboratory's Technical Area 16 discharged millions of gallons of HE- and barium-contaminated water into the Canon de Valle watershed. The effluent contaminated surface soils, the alluvial aquifer, vadose zone waters, and deep-perched and regional groundwaters with HE and barium, frequently at levels greater than regulatory standards. Site characterization studies began in 1995 and included extensive monitoring of surface water, groundwater, soils, and subsurface solid media. Hydrogeologic and geophysical studies were conducted to help understand contaminant transport mechanisms and pathways. Results from the characterization studies were used to develop a site conceptual model. In 2000 the principal source area was removed. The ongoing Corrective Measure Study (CMS) and Corrective Measure Implementation (CMI) focus on residual vadose zone contamination and on the contaminated alluvial system. Regulators recently selected a CMI remedy that combined: 1) augmented source removal; 2) grouting of an HE- contaminated surge bed; 3) deployment of Stormwater Management System (SMS) stormfilters in contaminated springs; and 4) permeable reactive barriers (PRBs) in contaminated alluvium. The hydrogeologic conceptual model for the vadose zone and alluvial system as well as the status of the canyon as habitat for the Mexican Spotted Owl were key factors in selection of these minimal-environmental-impact remedies. The heterogeneous vadose zone, characterized by flow and contaminant transport in fractures and in surge beds, requires contaminant treatment at a point of discharge. The canyon PRB is being installed to capture water and contaminants prior to infiltration into the vadose zone. Pilot-scale testing of the SMS and lab-scale batch and column tests of a range of media suggest that granular activated carbon, zeolite, and gypsum may be effective media for removal of HE and/or barium from contaminated

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site at Grand Junction, Colorado. Revision 1

Energy Technology Data Exchange (ETDEWEB)

1994-09-01

This risk assessment evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy`s (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site at Grand Junction, Colorado. Revision 1

International Nuclear Information System (INIS)

1994-09-01

This risk assessment evaluates potential impacts to public health or the environment resulting from ground water contamination at the former uranium mill processing site. The tailings and other contaminated material at this site were placed in an off-site disposal cell by the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The remedial activities at the site were conducted from 1989 to 1993. Currently, the UMTRA Project is evaluating ground water contamination. This risk assessment evaluates the most contaminated ground water that flows beneath the processing site toward the Colorado River. The monitor wells that have consistently shown the highest concentrations of most contaminants are used to assess risk. This risk assessment will be used in conjunction with additional activities and documents to determine what remedial action may be needed for contaminated ground water at the site

Characterization of the vadose zone above a shallow aquifer contaminated with gas condensate hydrocarbons

International Nuclear Information System (INIS)

Sublette, K.; Duncan, K.; Thoma, G.; Todd, T.

2002-01-01

A gas production site in the Denver Basin near Ft. Lupton, Colorado has leaked gas condensate hydrocarbons from an underground concrete tank used to store produced water. The leak has contaminated a shallow aquifer. Although the source of pollution has been removed, a plume of hydrocarbon contamination still remains for nearly 46 m from the original source. An extensive monitoring program was conducted in 1993 of the groundwater and saturated sediments. The objective was to determine if intrinsic aerobic or anaerobic bioremediation of hydrocarbons occurred at the site at a rate that would support remediation. Geochemical indicators of hydrogen biodegradation by microorganisms in the saturated zone included oxygen depletion, increased alkalinity, sulfate depletion, methane production and Fe2+ production associated with hydrogen contamination. The presence of sulfate-reducing bacteria and methanogens was also much higher in the contaminated sediments. Degraded hydrocarbon metabolites were found in contaminated groundwater. An extensive characterization of the vadose zone was conducted in which the vadose zone was sample in increments of 15 cm from the surface to the water table at contaminated and non contaminated sites. The samples were tested for individual C3+ hydrocarbons, methane, CO2, total organic carbon, total inorganic carbon, and total petroleum hydrocarbons. The vadose zone consisted of an active and aerobic bioreactor fueled by condensate hydrocarbons transported into the unsaturated zone by evaporation of hydrocarbons at the water table. It was concluded that the unsaturated zone makes an important contribution to the natural attenuation of gas condensate hydrocarbons in the area. 17 refs., 2 tabs., 28 figs

Chemical aspects of uranium behavior in soils: A review

Science.gov (United States)

Vodyanitskii, Yu. N.

2011-08-01

Uranium has varying degrees of oxidation (+4 and +6) and is responsive to changes in the redox potential of the environment. It is deposited at the reduction barrier with the participation of biota and at the sorption barrier under oxidative conditions. Iron (hydr)oxides are the strongest sorbents of uranium. Uranium, being an element of medium biological absorption, can accumulate (relative to thorium) in the humus horizons of some soils. The high content of uranium in uncontaminated soils is most frequently inherited from the parent rocks in the regions of positive U anomalies: in the soils developed on oil shales and in the marginal zone of bogs at the reduction barrier. The development of nuclear and coal-fired power engineering resulted in the environmental contamination with uranium. The immobilization of anthropogenic uranium at artificial geochemical barriers is based on two preconditions: the stimulation of on-site metal-reducing bacteria or the introduction of strong mineral reducers, e.g., Fe at low degrees of oxidation.

Radiation hazards in the neighbourhood of uranium reactors; Dangers des rayonnements aupres des piles a uranium

Energy Technology Data Exchange (ETDEWEB)

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

1956-07-01

Radiation hazards near uranium reactors may be divided in two groups. Hazards when the reactor is normally operating: {gamma} radiation from hot uranium or air contamination by fission gases, {gamma} radiation or contamination by the coolant (air, nitrogen, heavy-water), {gamma} radiation from radioisotopes. Hazards in the case of an accident: presence of hot uranium in the atmosphere, soil contamination. (author) [French] Les dangers d'irradiation aupres des piles a uranium sont a classer essentiellement en deux groupes. Les dangers existant aupres d'une pile exploitee normalement: irradiation {gamma} par l'uranium irradie ou contamination de l'air par des gaz de fission, irradiation {gamma} ou contamination par les fluides de refroidissement (air, azote, eau lourde), irradiation {gamma} par les radioelements fabriques. Les dangers en cas d'accident survenant a un reacteur en fonctionnement, ayant pour consequence : la presence dans l'air d'uranium irradie, la contamination du sol. (auteur)

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-08-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase I), and the Ground Water Project (phase II). For the UMTRA Project site located near Naturita, Colorado (the Naturita site), phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation`s Upper Burbank Repository at Uravan, Colorado, about 13 road miles (mi) (21 kilometers [km]) to the northwest. No uranium mill tailings are involved because the tailings were removed from the Naturita site and placed at Coke Oven, Colorado, during 1977 to 1979. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health or the environment; and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water, or surface water that has received contaminated ground water. Therefore, a risk assessment is conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado

International Nuclear Information System (INIS)

1995-08-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase I), and the Ground Water Project (phase II). For the UMTRA Project site located near Naturita, Colorado (the Naturita site), phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation's Upper Burbank Repository at Uravan, Colorado, about 13 road miles (mi) (21 kilometers [km]) to the northwest. No uranium mill tailings are involved because the tailings were removed from the Naturita site and placed at Coke Oven, Colorado, during 1977 to 1979. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health or the environment; and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water, or surface water that has received contaminated ground water. Therefore, a risk assessment is conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

Energy Technology Data Exchange (ETDEWEB)

Lagauzere, S. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)], E-mail: lagauzere@gmail.com; Pischedda, L.; Cuny, P. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Gilbert, F. [EcoLab, Laboratoire d' Ecologie Fonctionnelle, UMR 5245 CNRS/INP/Universite Paul Sabatier, 29 Rue Jeanne Marvig, F-31055 Cedex 4, Toulouse (France); Stora, G. [Laboratoire de Microbiologie, Geochimie et Ecologie Marines, UMR 6117 CNRS/COM/Universite de la Mediterranee, Campus de Luminy, Case 901, F-13288 Cedex 09, Marseille (France); Bonzom, J.-M. [Laboratoire de Radioecologie et d' Ecotoxicologie, Institut de Radioprotection et de Surete Nucleaire (IRSN), DEI/SECRE/LRE, Cadarache 186, BP 3, F-13115 Cedex, Saint Paul Lez Durance (France)

2009-04-15

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments.

Influence of Chironomus riparius (Diptera, Chironomidae) and Tubifex tubifex (Annelida, Oligochaeta) on oxygen uptake by sediments. Consequences of uranium contamination

International Nuclear Information System (INIS)

Lagauzere, S.; Pischedda, L.; Cuny, P.; Gilbert, F.; Stora, G.; Bonzom, J.-M.

2009-01-01

The diffusive oxygen uptake (DOU) of sediments inhabited by Chironomus riparius and Tubifex tubifex was investigated using a planar oxygen optode device, and complemented by measurements of bioturbation activity. Additional experiments were performed within contaminated sediments to assess the impact of uranium on these processes. After 72 h, the two invertebrate species significantly increased the DOU of sediments (13-14%), and no temporal variation occurred afterwards. Within contaminated sediments, it was already 24% higher before the introduction of the organisms, suggesting that uranium modified the sediment biogeochemistry. Although the two species firstly reacted by avoidance of contaminated sediment, they finally colonized it. Their bioturbation activity was reduced but, for T. tubifex, it remained sufficient to induce a release of uranium to the water column and an increase of the DOU (53%). These results highlight the necessity of further investigations to take into account the interactions between bioturbation, microbial metabolism and pollutants. - This study highlights the ecological importance of bioturbation in metal-contaminated sediments

The peculiarities of evolution of the hypergene zone at the uranium-phosphate deposit

International Nuclear Information System (INIS)

Glagolev, N.A.

1979-01-01

The study of peculiarities of hypergene zone evolution at the uranium-phosphate deposit has been carried out to clarify possibilities of qualitative and quantitative estimation of primary ores as to their outputs at search works. Bed-like deposit of phosphorites occurs together with ore-containing limestones and at considerable length it comes out at the day surface. Hypergenously unchanged phosphorites present grey microcrystallic carbonate-apatite ores, comprising fluoroapatite (60-80%) and calcite. It is shown, that the greater part of uranium in unchanged ores is bound with U- and Th containing fluoroapatite, U amounts being low

Physical properties of uranium host rocks and experimental drilling at Long Park, Montrose County, Colorado. Final report

International Nuclear Information System (INIS)

Manger, G.E.; Gates, G.L.; Cadigan, R.A.

1975-01-01

A core-drilling study in uranium host rocks of the Jurassic Morrison Formation in southwestern Colorado attempted to obtain samples of host rock in its natural state. Three holes were drilled, holes and core were logged for radioactivity and electrical properties. Samples were analyzed for physical and chemical properties. Drilling results suggest that drilling with dried air yields core with least contamination at least cost. Drilling with oil results in maximum core recovery but also maximum cost and significant core contamination. Drilling with water results in contamination and loss of original pore water. A factor group of variables present are: Those positively related to uranium mineralization are poor sorting, percent by weight clay, percent of pore space containing water; negatively related variables are median grain size (mm), electrical resistivity, permeability. Optimum depth to locate ore seems to be at the top of the pore water capillary circulation zone, below the dehydrated no-capillary-circulation zone

An integrated study of aerospace data for uranium exploration in the Magajhi-Kotapali shear zone, Surguja district, Madhya Pradesh, India

International Nuclear Information System (INIS)

Chaturvedi, A.K.; Kak, S.N.

1993-01-01

Lower Proterozoic granite gneiss and associated cataclastic rocks of Surguja crystalline complex record uranium mineralisation along the WNW-ESE trending Magajhi-Kotapali shear zone. Extension of the shear zone and cross faults trending NE-SW were established using enhanced satellite data. On integrating it with aeroradiometric data, it has been found that uranium mineralisation is shear controlled and occur around the zone of intersection between the WNW-ESE trending shear and the NE-SW faults. The study has narrowed down the target area for detailed ground investigations and finally resulted in locating promising areas such as Chathila Pahar, Haskepi, Jarhakhar-Semarkhar, and Tilti forest with good extensions along the shear zone. (author). 18 refs., 5 figs

Remediation of lead, cadmium and uranium contaminated water and soil by apatite amendment

International Nuclear Information System (INIS)

Raicevic, S.; Plecas, I.; Kaludjerovic, T.

2002-01-01

During the past years as a consequence of war and some accidents in neighboring countries large areas in Serbia were contaminated by toxic heavy metals, including lead, cadmium and uranium. For example, the concentrations of Pb, Cd, Cu and Cr have been doubled above the allowed maximum value in the Romanian part of the Danube while sediments near the border in Bulgaria have higher concentrations of Pb 3 times, Cu 1400 times and Cd 30 times more than the average long-standing levels. Furthermore, an estimated 10 tons of depleted uranium (DU) was spread mainly throughout the territory of Kosovo. This contamination is a potential source of different chronic diseases including malignant diseases and represents a long-term threat for the population living in the affected areas. For this reason, remediation of contaminated sites represents an urgent need and priority. The standard remediation procedure which includes soil removal, treatment (washing, chelating), conditioning etc. is costly, disruptive and not sustainable. This study was carried out to evaluate apatite from the Lisina deposit as soil amendment for in situ stabilization of toxic heavy metals. Preliminary theoretical and experimentally results presented here point out this natural apatite as an ecological, nontoxic material which can be used for efficient and cost-effective remediation of large areas contaminated with Pb, Cd and U. (author)

Field demonstration of technologies for delineating uranium contaminated soils

International Nuclear Information System (INIS)

Tidwell, V.C.; Cunnane, J.C.; Schwing, J.; Lee, S.Y.; Perry, D.L.; Morris, D.E.

1993-01-01

An Integrated Demonstration Program, hosted by the Fernald Environmental Restoration Management Corporation (FERMCO), has been established for investigating technologies applicable to the characterization and remediation of soils contaminated with uranium. An important part of this effort is the evaluation of field screening tools capable of acquiring high resolution information on the distribution of uranium contamination in surface soils in a cost-and-time efficient manner. Consistent with this need, four field screening technologies have been demonstrated at two hazardous waste sites at the FERMCO. The four technologies tested are wide-area gamma spectroscopy, beta scintillation counting, laser ablation-inductively coupled plasma-atomic emission spectroscopy (LA-ICP-AES), and long-range alpha detection (LRAD). One of the important findings of this demonstration was just how difficult it is to compare data collected by means of multiple independent measurement techniques. Difficulties are attributed to differences in measurement scale, differences in the basic physics upon which the various measurement schemes are predicated, and differences in the general performance of detector instrumentation. It follows that optimal deployment of these techniques requires the development of an approach for accounting for the intrinsic differences noted above. As such, emphasis is given in this paper to the development of a methodology for integrating these techniques for use in site characterization programs as well as the development of a framework for interpreting the collected data. The methodology described here also has general application to other field-based screening technologies and soil sampling programs

Physicochemical and mineralogical characterization of transuranic contaminated soils for uranium soil integrated demonstration

International Nuclear Information System (INIS)

Elless, M.P.; Lee, S.Y.

1994-10-01

DOE has initiated the Uranium Soils Integrated Demonstration (USID) project. The objective of the USID project is to develop a remediation strategy that can be adopted for use at other DOE sites requiring remediation. Four major task groups within the USID project were formed, namely the Characterization Task Group (CTG), the Treatability Task Group (TTG), the Secondary Waste Treatment and Disposal Task Group (SWTDTG), and the Risk and Performance Assessment Task Group (RPATG). The CTG is responsible for determining the nature of the uranium contamination in both untreated and treated soil. The TTG is responsible for the selective removal of uranium from these soils in such a manner that the leaching does not seriously degrade the soil's physicochemical characteristics or generate a secondary waste form that is difficult to manage and/or dispose. The SWTDTG is responsible for developing strategies for the removal of uranium from all wastewaters generated by the TTGs. Finally the RPATG is responsible for developing the human health and environmental risk assessment of the untreated and treated soils. Because of the enormity of the work required to successfully remediate uranium-contaminated soils, an integrated approach was designed to avoid needless repetition of activities among the various participants in the USID project. Researchers from Oak Ridge National Laboratory (ORNL), Los Alamos National Laboratory (LANL), Argonne National Laboratory (ANL), and Idaho National Engineering Laboratory (INEL) were assigned characterization and/or treatability duties in their areas of specialization. All tasks groups are involved in the integrated approach; however, the thrust of this report concentrates on the utility of the integrated approach among the various members of the CTG. This report illustrates the use of the integrated approach for the overall CTG and to provide the results generated specifically by the CTG or ORNL from FY1993 to the present

Remediation of Soil Contaminated with Uranium using a Biological Method

International Nuclear Information System (INIS)

Park, Hye Min; Kim, Gye Nam; Shon, Dong Bin; Lee, Ki Won; Chung, Un Soo; Moon, Jai Kwon

2011-01-01

Bioremediation is a method to cleanup contaminants in soil or ground water with microorganisms. The biological method can reduce the volume of waste solution and the construction cost and operation cost of soil remediation equipment. Bioremediation can be divided into natural attenuation, bioaugmentation, biostimulation. Biostimulation is technology to improve natural purification by adding nutritional substances, supplying oxygen and controlling pH. In this study, penatron, that is a nutritional substances, was mixed with soil. Optimum conditions for mixing ratios of penatron and soil, and the pH of soil was determined through several bioremediation experiments with soil contaminated with uranium. Also, under optimum experiment conditions, the removal efficiencies of soil and concrete according to reaction time were measured for feasibility analysis of soil and concrete bioremediations

Preliminary discussion on uranium metallogenic models of China's in-situ leachable sandstone-type uranium deposits

International Nuclear Information System (INIS)

Zhang Jindai; Xu Gaozhong; Chen Anping; Wang Cheng

2005-01-01

By comprehensively analyzing metallogenic environments and main ore-controlling factors of important uranium metallogenic regions of in-situ leachable sandstone-type uranium deposits at the southern margin of Yili basin, at the south-western margin of Turpan-Hami basin and in the northeastern Ordos basin, the authors of this paper discuss the metallogenic models of China's in-situ leachable sandstone-type uranium deposits, and suggest that the interlayer oxidation zone type uranium deposits in Yili and Turpan-Hami basins are basically controlled by favourable structures, sedimentary formations and interlayer oxidation zone, and are characterized by multistage uranium concentration, namely the uranium pre-concentration of ore-hosting sedimentary formation, the uranium ore-formation in the stage of supergenic epigenetic reworking, and the further superimposition enrichment of post-ore tectonic activity. However, the interlayer oxidation zone type uranium deposit in the northeastern Ordos was formed after the formation of the secondary reduction. So, paleo-interlayer oxidation zone type uranium mineralization has the mineralization size much greater than the former two. (authors)

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-11-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project, and the Ground Water Project. For the UMTRA Project site located near Naturita, Colorado, phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation`s Upper Burbank Repository at Uravan, Colorado. The surface cleanup will reduce radon and other radiation emissions from the former uranium processing site and prevent further site-related contamination of ground water. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health and the environment, and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water or surface water that has mixed with contaminated ground water. Therefore, a risk assessment was conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Naturita, Colorado. Revision 1

International Nuclear Information System (INIS)

1995-11-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project, and the Ground Water Project. For the UMTRA Project site located near Naturita, Colorado, phase I involves the removal of radioactively contaminated soils and materials and their transportation to a disposal site at Union Carbide Corporation's Upper Burbank Repository at Uravan, Colorado. The surface cleanup will reduce radon and other radiation emissions from the former uranium processing site and prevent further site-related contamination of ground water. Phase II of the project will evaluate the nature and extent of ground water contamination resulting from uranium processing and its effect on human health and the environment, and will determine site-specific ground water compliance strategies in accordance with the US Environmental Protection Agency (EPA) ground water standards established for the UMTRA Project. Human health risks could occur from drinking water pumped from a hypothetical well drilled in the contaminated ground water area. Environmental risks may result if plants or animals are exposed to contaminated ground water or surface water that has mixed with contaminated ground water. Therefore, a risk assessment was conducted for the Naturita site. This risk assessment report is the first site-specific document prepared for the Ground Water Project at the Naturita site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine whether any action is needed to protect human health or the environment

Baseline risk assessment of ground water contamination at the Monument Valley Uranium Mill Tailings Site, Cane Valley, Arizona. Revision 1

Energy Technology Data Exchange (ETDEWEB)

1994-08-01

This baseline risk assessment evaluates potential impact to public health or the environment from ground water contamination at the former uranium mill processing site in Cane Valley near Monument Valley, Arizona. The US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project has relocated and stabilized this site`s tailings and other contaminated material in a disposal cell at Mexican Hat, Utah. The second phase of the UMTRA Project is to evaluate ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project that evaluates potential health and environmental risks. It will help determine the approach required to address contaminated ground water at the site.

Baseline risk assessment of ground water contamination at the Monument Valley Uranium Mill Tailings Site, Cane Valley, Arizona. Revision 1

International Nuclear Information System (INIS)

1994-08-01

This baseline risk assessment evaluates potential impact to public health or the environment from ground water contamination at the former uranium mill processing site in Cane Valley near Monument Valley, Arizona. The US Department of Energy (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project has relocated and stabilized this site's tailings and other contaminated material in a disposal cell at Mexican Hat, Utah. The second phase of the UMTRA Project is to evaluate ground water contamination. This risk assessment is the first document specific to this site for the Ground Water Project that evaluates potential health and environmental risks. It will help determine the approach required to address contaminated ground water at the site

Decontamination process development for gravels contaminated with uranium

Energy Technology Data Exchange (ETDEWEB)

Kim, Gye Nam; Park, Uk Ryang; Kim, Seung Su; Kim, Won Suk; Moon, Jei Kwon [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2013-10-15

It is impossible to scrub gravels in a washing tank, because gravels sinks to the bottom of the washing tank. In addition, when electrokinetic decontamination technology is applied to gravels larger than 10 cm, the removal efficiency of uranium from the gravels is reduced, because electro-osmotic flux at the surface of the gravel in electrokinetic cell reduces owing to a reduction of the particle surface area attributable to large-sized gravel. The volume ratio of gravel larger than10 cm in total volume of the soil in KAERI was about 20%. Therefore, it is necessary to study the decontamination process of gravels contaminated with radionuclides. The optimum number of washings for contaminated gravels is considered to be two. In addition, the removal efficiency of contaminated gravel was not related to its weight. For an electrokinetic-electrodialytic decontamination period of 5 days, 10 days, 15 days, and 20 days, {sup 238}U in gravel was removed by about 42%, 64%, 74%, and 80%, respectively. The more the decontamination time elapsed, the greater the reduction of the removal efficiency ratio of {sup 238}U. The decontamination process for gravels was generated on the basis of the results of washing and electrokinetic electrodialtic experiments.

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

International Nuclear Information System (INIS)

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

2006-01-01

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

The supposed radioactive contamination of the Puelche aquifer

International Nuclear Information System (INIS)

Martini, Leopoldo E.

2005-01-01

The paper attempts to clarify the supposed radioactive contamination of the Puelche Aquifer in the Ezeiza Atomic Center Area, Ezeiza, province of Buenos Aires (Argentina). Reports are listed that show categorically that no anthropogenic uranium contamination is present. As far as the nitrates contamination is concerned, it is not generated by the Ezeiza Atomic Center, because the Center is downward from the contaminated zone. It is possible that the contamination is produced by houses in the area without suitable sewage. In the present case the best contribution to the environmental right, besides the adaptation and the systematization of the different legal instruments, is to found the analysis of the facts on the scientific and technical knowledge. (author) [es

Fundamental study on decontamination of wastes contaminated by uranium fluorides by using ionic liquids - dissolution and electrochemistry of uranium in 1-butyl-3-methylimidazolium chloride

International Nuclear Information System (INIS)

Noriko Asanuma; Yusuke Ohhashi; Yukio Wada; Masayuki Harada; Yasuhisa Ikeda

2008-01-01

Treatment method for wastes contaminated uranium fluorides by using ionic liquids as media of pyrochemical process instead of alkali metal chloride molten salts was proposed. In this method, uranium fluorides such as UF 4 or NaF adsorbing UF 6 are dissolved in 1-butyl-3-methylimidazolium chloride (BMICl) and dissolved uranium species are recovered as deposits by electrochemical reduction. Under the atmospheric condition, UF 4 was completely dissolved in BMICl at 100 deg. C. UV-vis absorption spectra of the sample solution indicated that main species of uranium are U(VI) and a part of uranium exists as U(IV). Chemical form of uranium in the NaF adsorbents is Na 3 UO 2 F 5 . Therefore, it was immediately dissolved to BMICl. However, complete dissolution was not achieved. Cyclic voltammetry of the solutions prepared by dissolution experiments was performed. Redox properties of uranium species in each sample were irreversible. It was assigned to reduction of U(VI) to U(IV). As a result of preliminary bulk electrolysis, it was expected that reduction products are deposited on the carbon cathode. (authors)

A metallogenetic model of supergene extraction, releasing and enrichment in the mixed zone for granite-type uranium deposits in south China

International Nuclear Information System (INIS)

Li Minglian.

1986-01-01

The major geological features and their related geological events provide a base for the modelling of granite-type uranium deposits in South China. This paper presents a metallogenetic model to suggest the process of ore fluid circulation. There are two streams of ore fluids moving in the fracture zone: one comes from meteoric water and extracts uranium from wall rocks, flowing from top to bottom which is named uranium-loading fluid; another derives from the depth of the crust flowing from bottom to top and contains reducing matters as H 2 S etc. called uranium-releasing fluid. These two streams of solutions of different genesis, composition and character encountered and mixed at certain depth to precipitate the uranium. During the process the longitudinal circulation of underground thermal water in fracture zone results in the Bernoulli latitudinal circulation of ore fluids, which caused the ore fluids to ceaselessly flow into the minerogenetic location, where mineralization can be formed continuously in a certain period

Carbonate and citric acid leaching of uranium from uranium-contaminated soils: Pilot-scale studies (Phase II)

International Nuclear Information System (INIS)

Wilson, J.H.; Chernikoff, R.; DeMarco, W.D.

1995-10-01

The purpose of this document is to describe the results of the soil decontamination demonstration conducted at the Fernald Environmental Management Project (FEMP) site by the Fernald Environmental Restoration and Management Corporation (FERMCO) and the Oak Ridge National Laboratory (ORNL). This demonstration, which began in November 1993 and ended in October 1994, involved the removal of uranium from contaminated soil sampled from two FEMP sites. The demonstration was conducted so as to meet the requirements of the Fernald Site Integrated Demonstration program, as well as all environmental, safety, and health requirements of the site

Discussion on the interlayer oxidation and uranium metallogenesis in Qianjiadian uranium deposit, Songliao Basin

International Nuclear Information System (INIS)

Pang Yaqing; Chen Xiaolin; Fang Xiheng; Sun Ye

2010-01-01

Through systematic drill core observation, section contrast and analysis,it is proved that the ore-controlling interlayer oxidation zone of Qianjiadian uranium deposit is mainly composed by the red oxidized sandstone and locally distributed yellow and off-white sandstones. The red sandstone contains charcoal fragments, pyrite, ilmenite, siderite, which have been oxidized intensively, and it can be deduced that their original color was gray and became red due to the oxidization. The distribution of the oxidation zone is mainly controlled by the sedimentary facies,which also controll uranium metallization. The uranium orebodies mainly developed in the thinning or pinch parts of the red oxidation zone in section. On the plans, the uranium mineralization distributes near the front of the red interlayer oxidation zone. (authors)

The role indigenous bacterial isolates for bioremediation agent in the uranium contaminated aquatic environment

International Nuclear Information System (INIS)

Mochd Yazid

2014-01-01

A Research on the role of indigenous bacterial isolates for bio-remediation agent of the uranium contaminated in the aquatic environment has been conducted. The objective of the research is to study the role of Pseudomonas sp and Bacillus sp. have been isolated from low level uranium waste for bioremediation agent in their environment, such as the determination of efficiency of the uranium binding compared by the non indigenous bacterial, location of these binding and the influences of added acethyl acid stimulant. The uranium reduction studied was measured by weighting bacterial biomass and uranium concentration was measured by spectrophotometer. The acethyl acid stimulant addition has been done with the variation of concentration and volume. The efficiency of the uranium reduction by indigenous bacterial isolate such as Pseudomonas sp were 84.99 % and Bacillus sp were 52.70 %, so the reduction efficiency by non indigenous bacterial such as Pseudomonas aerogenes were 78.47 % and Bacillus subtilis were 45.22 % for 54 hours incubation time. The result of this research can be concluded that Pseudomonas sp and Bacillus sp. Indigenous bacterial have been isolates from the liquid uranium waste can contributed in bioremediation agent for uranium radionuclide in the environment for 60 ppm concentration with reduction efficiency 52.70 %-84.99 %, that is higher non indigenous bacterial for 54 hours incubation time, the stimulant addition of acethyl acid, the efficiency can be increased up to 99.8 %. (author)

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Site near Green River, Utah. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase 1) and the Ground Water Project (phase 2). For the UMTRA Project site located near Green River, Utah, the Surface Project cleanup occurred from 1988 to 1989. The tailings and radioactively contaminated soils and materials were removed from their original locations and placed into a disposal cell on the site. The disposal cell is designed to minimize radiation emissions and minimize further contamination of ground water beneath the site. 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. For the Green River site, the risk assessment helps determine whether human health risks result from exposure to ground water contaminated by uranium processing. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Green River site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization 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 Green River, Utah. Revision 1

International Nuclear Information System (INIS)

1995-09-01

The Uranium Mill Tailings Remedial Action (UMTRA) Project consists of the Surface Project (phase 1) and the Ground Water Project (phase 2). For the UMTRA Project site located near Green River, Utah, the Surface Project cleanup occurred from 1988 to 1989. The tailings and radioactively contaminated soils and materials were removed from their original locations and placed into a disposal cell on the site. The disposal cell is designed to minimize radiation emissions and minimize further contamination of ground water beneath the site. 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. For the Green River site, the risk assessment helps determine whether human health risks result from exposure to ground water contaminated by uranium processing. This risk assessment report is the first site-specific document prepared for the UMTRA Ground Water Project at the Green River site. What follows is an evaluation of current and possible future impacts to the public and the environment from exposure to contaminated ground water. The results of this evaluation and further site characterization will be used to determine what is necessary, if anything, to protect human health and the environment while complying with EPA standards

Bio-chemical remediation of under-ground water contaminated by uranium in-situ leaching

International Nuclear Information System (INIS)

Wang Qingliang; Li Qian; Zhang Hongcan; Hu Eming; Chen Yongbo

2014-01-01

In the process of uranium in-situ leaching, it was serious that strong acid, uranium and heavy metals, and SO_4"2"-, NO_3"- could contaminate underground water. To remedy these pollutants, conventional methods are high-cost and low-efficient, so a bio-chemical remediation method was proposed to cope with the under-ground water pollution in this study. The results showed, in the chemical treatment with Ca(OH)_2 neutralization, pH went up from 2.0 to 7.0, the removal rates of U, Mn"2"+, Zn"2"+, Pb"2"+, SO_4"2"-, NO_3"- were 91.5%, 78.3%, 85.1%, 100%, 71.4% and 2.6% respectively, SO_4"2"- and NO_3"- need to be treated again by bio-method. In the biological process, the Hydraulic Retention Time (HRT) of bioreactor was controlled at 42 h, and 100% NO_3"- and 70% SO_4"2"- in the contaminated water were removed; Acidithiobacillus ferrooxidans (A. f) liquid to H_2S showed better absorption effect, can fully meet the process requirements of H_2S removal. (authors)

Predictive geochemical modeling of uranium and other contaminants in laboratory columns in relatively oxidizing, carbonate-rich solutions

International Nuclear Information System (INIS)

Longmire, P.; Turney, W.R.; Mason, C.F.V.

1994-01-01

Carbonate heap leaching of uranium-contaminated soils and sediments represents a viable, cost-effective remediation technology. Column experiments have been conducted using 0.1, 0.25, and 0.5 M Na 2 CO 3 /NaHCO 3 solutions for leaching uranium from soils located adjacent to an incinerator at the Fernald Environmental Management Project (FEMP) site. Results from column experiments and geochemical modeling are used to quantitatively evaluate the effectiveness of heap leaching. Leach efficiencies of up to 72 wt.% of total uranium in CaO-agglomerated soil result from dissolution of uranium (U(VI)-dominated) minerals, formation of the soluble complex UO 2 (CO 3 ) 3 4- , and uranium desorption from clay minerals, ferric hydroxides, and humic acids. Parameters that control the extent of uranium extraction include pH, Eh, temperature, carbonate concentration, lixiviant-flow rate, pore-solution chemistry, solid phases, and soil texture

Exploration for in situ leach amenable sandstone uranium deposits and their impact on the environment in China

International Nuclear Information System (INIS)

Zhang Weixing

2002-01-01

Taking the No. 512 uranium deposit in YiLi Basin, Xinjiang as an example, this paper describes the ore-forming geological settings of inter-layer oxidizing zone roll-front type of ISL amenable uranium deposits. It also summarizes the different exploration methods used during various stages of exploration. The paper also introduces the Dabu uranium deposit in Taoshan, Jiangxi, which is amenable to the in-place-leach mining method. It probes into the possibilities for transforming non-economic and sub-economic uranium deposits into economical and minable ones. In addition, the paper emphasizes that ISL uranium mining, when compared with conventional mining, plays an active role in reducing environmental contamination and restoring ecological balance. (author)

Resolving superimposed ground-water contaminant plumes characterized by chromium, nitrate, uranium, and technetium--99

International Nuclear Information System (INIS)

Hall, S.H.

1990-02-01

Leakage from a liquid waste storage and solar evaporation basin at the Hanford Site in southeastern Washington State has resulted in a ground-water contaminant plume characterized by nitrate, hexavalent chromium, uranium, and technetium-99. The plume is superimposed on a larger, pre-existing plume extending from upgradient sites and having the same suite of contaminants. However, the relative abundance of contaminant species is quite different for each plume source. Thus, characteristic concentration ratios, rather than concentrations of individual species, are used as geochemical tracers, with emphasis on graphical analysis. Accordingly, it has been possible to resolve the boundaries of the smaller plume and to estimate the contribution of each plume to the observed contamination downgradient from the storage basin. 11 refs., 7 figs

Determination of uranium concentration and burn-up of irradiated reactor fuel in contaminated areas in Belarus using uranium isotopic ratios in soil samples

International Nuclear Information System (INIS)

Mironov, V.P.; Matusevich, J.L.; Kudrjashov, V.P.; Ananich, P.I.; Zhuravkov, V.V.; Boulyga, S.F.; Becker, J.S.

2005-01-01

An analytical method is described for the estimation of uranium concentrations, of 235 U/ 238 U and 236 U/ 238 U isotope ratios and burn-up of irradiated reactor uranium in contaminated soil samples by inductively coupled plasma mass spectrometry. Experimental results obtained at 12 sampling sites situated on northern and western radioactive fallout tails 4 to 53 km distant from Chernobyl nuclear power plant (NPP) are presented. Concentrations of irradiated uranium in the upper 0-10 cm soil layers at the investigated sampling sites varied from 2.1 x 10 -9 g/g to 2.0 x 10 -6 g/g depending mainly on the distance from Chernobyl NPP. A slight variation of the degree of burn-up of spent reactor uranium was revealed by analyzing 235 U/ 238 U and 236 U/ 238 U isotope ratios and the average value amounted to 9.4±0.3 MWd/(kg U). (orig.)

Determination of uranium concentration and burn-up of irradiated reactor fuel in contaminated areas in Belarus using uranium isotopic ratios in soil samples

Energy Technology Data Exchange (ETDEWEB)

Mironov, V.P.; Matusevich, J.L.; Kudrjashov, V.P.; Ananich, P.I.; Zhuravkov, V.V. [Inst. of Radiobiology, Minsk Univ. (Belarus); Boulyga, S.F. [Inst. of Inorganic Chemistry and Analytical Chemistry, Johannes Gutenberg-Univ. Mainz, Mainz (Germany); Becker, J.S. [Central Div. of Analytical Chemistry, Research Centre Juelich, Juelich (Germany)

2005-07-01

An analytical method is described for the estimation of uranium concentrations, of {sup 235}U/{sup 238}U and {sup 236}U/{sup 238}U isotope ratios and burn-up of irradiated reactor uranium in contaminated soil samples by inductively coupled plasma mass spectrometry. Experimental results obtained at 12 sampling sites situated on northern and western radioactive fallout tails 4 to 53 km distant from Chernobyl nuclear power plant (NPP) are presented. Concentrations of irradiated uranium in the upper 0-10 cm soil layers at the investigated sampling sites varied from 2.1 x 10{sup -9}g/g to 2.0 x 10{sup -6}g/g depending mainly on the distance from Chernobyl NPP. A slight variation of the degree of burn-up of spent reactor uranium was revealed by analyzing {sup 235}U/{sup 238}U and {sup 236}U/{sup 238}U isotope ratios and the average value amounted to 9.4{+-}0.3 MWd/(kg U). (orig.)

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

International Nuclear Information System (INIS)

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

1976-01-01

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

Uranium Immobilization in Wetland Soils

Science.gov (United States)

Jaffe, Peter R.; Koster van Groos, Paul G.; Li, Dien; Chang, Hyun-Shik; Seaman, John C.; Kaplan, Daniel I.; Peacock, Aaron D.; Scheckel, Kirk

2014-05-01

In wetlands, which are a major feature at the groundwater-surface water interface, plants deliver oxygen to the subsurface to keep root tissue aerobic. Some of this oxygen leaches into the rhizosphere where it will oxidize iron that typically precipitates on or near roots. Furthermore, plans provide carbon via root exudates and turnover, which in the presence of the iron oxides drives the activity of heterotrophic iron reducers in wetland soils. Oxidized iron is an important electron acceptor for many microbially-driven transformations, which can affect the fate and transport of several pollutants. It has been shown that heterotrophic iron reducing organisms, such as Geobacter sp., can reduce water soluble U(VI) to insoluble U(IV). The goal of this study was to determine if and how iron cycling in the wetland rhizosphere affects uranium dynamics. For this purpose, we operated a series of small-scale wetland mesocosms in a greenhouse to simulate the discharge of uranium-contaminated groundwater to surface waters. The mesocosms were operated with two different Fe(II) loading rates, two plant types, and unplanted controls. The mesocosms contained zones of root exclusion to differentiate between the direct presence and absence of roots in the planted mesocosms. The mesocosms were operated for several month to get fully established, after which a U(VI) solution was fed for 80 days. The mesocosms were then sacrificed and analyzed for solid-associated chemical species, microbiological characterization, micro-X-ray florescence (µ-XRF) mapping of Fe and U on the root surface, and U speciation via X-ray Absorption Near Edge Structure (XANES). Results showed that bacterial numbers including Geobacter sp., Fe(III), as well as total uranium, were highest on roots, followed by sediments near roots, and lowest in zones without much root influence. Results from the µ-XRF mapping on root surfaces indicated a strong spatial correlation between Fe and U. This correlation was

Deep Vadose Zone Treatability Test of Soil Desiccation for the Hanford Central Plateau: Final Report

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [CH2M Hill Plateau Remediation Co., Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Freedman, Vicky L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Rockhold, Mark L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Greenwood, William J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Peterson, John E. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Hubbard, Susan S. [Lawrence Berkeley National Lab. (LBNL), Berkeley, CA (United States); Ward, Anderson L. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2018-02-20

Some of the inorganic and radionuclide contaminants in the deep vadose zone at the Hanford Site are at depths where direct exposure pathways are not of concern, but may need to be remediated to protect groundwater. The Department of Energy developed a treatability test program for technologies to address Tc-99 and uranium in the deep vadose zone. These contaminants are mobile in the subsurface environment, have been detected at high concentrations deep in the vadose zone, and at some locations have reached groundwater. The treatability test of desiccation described herein was conducted as an element of the deep vadose zone treatability test program. Desiccation was shown to be a potentially effective vadose zone remediation technology to protect groundwater when used in conjunction with a surface infiltration barrier.

Vadose zone studies at an industrial contaminated site: the vadose zone monitoring system and cross-hole geophysics

Science.gov (United States)

Fernandez de Vera, Natalia; Beaujean, Jean; Jamin, Pierre; Nguyen, Frédéric; Dahan, Ofer; Vanclooster, Marnik; Brouyère, Serge

2014-05-01

In order to improve risk characterization and remediation measures for soil and groundwater contamination, there is a need to improve in situ vadose zone characterization. However, most available technologies have been developed in the context of agricultural soils. Such methodologies are not applicable at industrial sites, where soils and contamination differ in origin and composition. In addition, most technologies are applicable only in the first meters of soils, leaving deeper vadose zones with lack of information, in particular on field scale heterogeneity. In order to overcome such difficulties, a vadose zone experiment has been setup at a former industrial site in Belgium. Industrial activities carried out on site left a legacy of soil and groundwater contamination in BTEX, PAH, cyanide and heavy metals. The experiment comprises the combination of two techniques: the Vadose Zone Monitoring System (VMS) and cross-hole geophysics. The VMS allows continuous measurements of water content and temperature at different depths of the vadose zone. In addition, it provides the possibility of pore water sampling at different depths. The system is formed by a flexible sleeve containing monitoring units along its depth which is installed in a slanted borehole. The flexible sleeve contains three types of monitoring units in the vadose zone: Time Domain Transmissometry (TDT), which allows water content measurements; Vadose Sampling Ports (VSP), used for collecting water samples coming from the matrix; the Fracture Samplers (FS), which are used for retrieving water samples from the fractures. Cross-hole geophysics techniques consist in the injection of an electrical current using electrodes installed in vertical boreholes. From measured potential differences, detailed spatial patterns about electrical properties of the subsurface can be inferred. Such spatial patterns are related with subsurface heterogeneities, water content and solute concentrations. Two VMS were

Fundamental study on decontamination of wastes contaminated by uranium fluorides by using ionic liquids - dissolution and electrochemistry of uranium in 1-butyl-3-methylimidazolium chloride

Energy Technology Data Exchange (ETDEWEB)

Noriko Asanuma [Department of Energy Science and Engineering, School of Engineering, Tokai University 1117 Kitakaname, Hiratsuka-shi, Kanagawa 259-1292 (Japan); Yusuke Ohhashi; Yukio Wada [Ningyo-toge Environmental Engineering Center, Japan Atomic Energy Agency Kagamino-cho, Tomata-gun, Okayama 708-0698 (Japan); Masayuki Harada; Yasuhisa Ikeda [Research Laboratory for Nuclear Reactors, Tokyo Institute of Technology 2-12-1-N1-34 Ookayama, Meguro-ku, Tokyo 152-8550 (Japan)

2008-07-01

Treatment method for wastes contaminated uranium fluorides by using ionic liquids as media of pyrochemical process instead of alkali metal chloride molten salts was proposed. In this method, uranium fluorides such as UF{sub 4} or NaF adsorbing UF{sub 6} are dissolved in 1-butyl-3-methylimidazolium chloride (BMICl) and dissolved uranium species are recovered as deposits by electrochemical reduction. Under the atmospheric condition, UF{sub 4} was completely dissolved in BMICl at 100 deg. C. UV-vis absorption spectra of the sample solution indicated that main species of uranium are U(VI) and a part of uranium exists as U(IV). Chemical form of uranium in the NaF adsorbents is Na{sub 3}UO{sub 2}F{sub 5}. Therefore, it was immediately dissolved to BMICl. However, complete dissolution was not achieved. Cyclic voltammetry of the solutions prepared by dissolution experiments was performed. Redox properties of uranium species in each sample were irreversible. It was assigned to reduction of U(VI) to U(IV). As a result of preliminary bulk electrolysis, it was expected that reduction products are deposited on the carbon cathode. (authors)

Microbial links between sulfate reduction and metal retention in uranium- and heavy metal-contaminated soil

DEFF Research Database (Denmark)

Sitte, Jana; Akob, Denise M.; Kaufmann, Christian

2010-01-01

Sulfate-reducing bacteria (SRB) can affect metal mobility either directly by reductive transformation of metal ions, e.g., uranium, into their insoluble forms or indirectly by formation of metal sulfides. This study evaluated in situ and biostimulated activity of SRB in groundwater-influenced soils...... from a creek bank contaminated with heavy metals and radionuclides within the former uranium mining district of Ronneburg, Germany. In situ activity of SRB, measured by the 35SO42– radiotracer method, was restricted to reduced soil horizons with rates of 142 ± 20 nmol cm–3 day–1. Concentrations...... of heavy metals were enriched in the solid phase of the reduced horizons, whereas pore water concentrations were low. X-ray absorption near-edge structure (XANES) measurements demonstrated that 80% of uranium was present as reduced uranium but appeared to occur as a sorbed complex. Soil-based dsrAB clone...

Uranium in bone: metabolic and autoradiographic studies in the rat

International Nuclear Information System (INIS)

Priest, N.D.; Haines, J.W.; Howells, G.R.; Green, D.

1982-01-01

The distribution and retention of intravenously injected hexavalent uranium-233 in the skeleton of the female rat has been investigated using a variety of autoradiographic and radiochemical techniques. These showed that approximately one third of the injected uranium is deposited in the skeleton where it is retained with an initial biological half-time of approximately 40 days. The studies also showed that: 1) Uranium is initially deposited on to all types of bone surface, but preferentially on to those that are accreting. 2) Uranium is deposited in the calcifying zones of skeletal cartilage. 3) Bone accretion results in the burial of surface deposits of uranium. 4) Bone resorption causes the removal of uranium from surfaces. 5) Resorbed uranium is not retained by osteoclasts and macrophages in the bone marrow. 6) Uranium removed from bone surfaces enters the bloodstream where most is either redeposited in bone or excreted via the kidneys. 7) The recycling of resorbed uranium within the skeleton tends to produce a uniform level of uranium contamination throughout mineralized bone. These results are taken to indicate that uranium deposition in bone shares characteristics in common with both the 'volume-seeking radionuclides' typified by the alkaline earth elements and with the 'bone surface-seeking radionuclides' typified by plutonium. (author)

Uranium in bone: metabolic and autoradiographic studies in the rat.

Science.gov (United States)

Priest, N D; Howells, G R; Green, D; Haines, J W

1982-03-01

The distribution and retention of intravenously injected hexavalent uranium-233 in the skeleton of the female rat has been investigated using a variety of autoradiographic and radiochemical techniques. These showed that approximately one third of the injected uranium is deposited in the skeleton where it is retained with an initial biological half-time of approximately 40 days. The studies also showed that: 1 Uranium is initially deposited onto all types of bone surface, but preferentially onto those that are accreting. 2 Uranium is deposited in the calcifying zones of skeletal cartilage. 3 Bone accretion results in the burial of surface deposits of uranium. 4 Bone resorption causes the removal of uranium from surfaces. 5 Resorbed uranium is not retained by osteoclasts and macrophages in the bone marrow. 6 Uranium removed from bone surfaces enters the bloodstream where most is either redeposited in bone or excreted via the kidneys. 7 The recycling of resorbed uranium within the skeleton tends to produce a uniform level of uranium contamination throughout mineralized bone. These results are taken to indicate that uranium deposition in bone shares characteristics in common with both the 'volume-seeking radionuclides' typified by the alkaline earth elements and with the 'bone surface-seeking radionuclides' typified by plutonium.

The characteristics of original geochemical halo in fault zone and its prospecting significance in Xiangyangping uranium deposit

International Nuclear Information System (INIS)

Ouyang Pingning; Huang Manxiang; Liu Xinyang; Chen Yue; Xiao Jianjun

2012-01-01

Xiangyangping uranium deposit is a hydrothermal filling deposit controlled by faults. The axial zonation of original element along the fault is sequence of Ni-Rb-Bi-Sn-Cu-W-Hg→As-U-Sb-Mo→Sr-Zn which shows the characteristics of superimposed halos and multiphase mineralization. The distribution characteristics of original halos along structure suggests that uranium mineralization may possess multi-enrichment zones along axial and strata tend. These characteristics are of prospecting significance. (authors)

Health effects estimation: Methods and results for uranium mill tailings contaminated properties

International Nuclear Information System (INIS)

Denham, D.H.; Cross, F.T.; Soldat, J.K.

1990-01-01

This paper describes methods for estimating potential health effects from exposure to uranium mill tailings and presents a summary of risk projections for 50 contaminated properties (residences, schools, churches, and businesses) in the US. The methods provide realistic estimates of cancer risk to exposed individuals based on property-specific occupancy and contamination patterns. External exposure to gamma radiation, inhalation of radon daughters, and consumption of food products grown in radium-contaminated soil are considered. Most of the projected risk was from indoor exposure to radon daughters; however, for some properties the risk from consumption of locally grown food products is similar to that from radon daughters. In all cases, the projected number of lifetime cancer deaths for specific properties is less than one, but for some properties the increase in risk over that normally expected is greater than 100%

Characterization of Vadose Zone Sediments from C Waste Management Area: Investigation of the C-152 Transfer Line Leak

Energy Technology Data Exchange (ETDEWEB)

Brown, Christopher F; Serne, R JEFFREY; Bjornstad, Bruce N; Valenta, Michelle M; Lanigan, David C; Vickerman, Tanya S; Clayton, Ray E; Geiszler, Keith N; Iovin, Cristian; Clayton, Eric T; Kutynakov, I V; Baum, Steven R; Lindberg, Michael J; Orr, Robert D

2007-02-05

A geologic/geochemical investigation in the vicinity of UPR-200-E-82 was performed using pairs of cone-penetrometer probe holes. A total of 41 direct-push cone-penetrometer borings (19 pairs to investigate different high moisture zones in the same sampling location and 3 individual) were advanced to characterize vadose zone moisture and the distribution of contaminants. A total of twenty sample sets, containing up to two split-spoon liners and one grab sample, were delivered to the laboratory for characterization and analysis. The samples were collected around the documented location of the C-152 pipeline leak, and created an approximately 120-ft diameter circle around the waste site. UPR-200-E-82 was a loss of approximately 2,600 gallons of Cs-137 Recovery Process feed solution containing an estimated 11,300 Ci of cesium-137 and 5 Ci of technetium-99. Several key parameters that are used to identify subsurface contamination were measured, including: water extract pH, electrical conductivity, nitrate, technetium-99, sodium, and uranium concentrations and technetium-99 and uranium concentrations in acid extracts. All of the parameters, with the exception of electrical conductivity, were elevated in at least some of the samples analyzed as part of this study. Specifically, soil pH was elevated (from 8.69 to 9.99) in five samples collected northeast and southwest of the C-152 pipeline leak. Similarly, samples collected from these same cone-pentrometer holes contained significantly more water-extractable sodium (more than 50 g/g of dry sediment), uranium (as much as 7.66E-01 g/g of dry sediment), nitrate (up to 30 g/g of dry sediment), and technetium-99 (up to 3.34 pCi/g of dry sediment). Most of the samples containing elevated concentrations of water-extractable sodium also had decreased levels of water extractable calcium and or magnesium, indicating that tank-related fluids that were high in sodium did seep into the vadose zone near these probe holes. Several of the

Examination of the health status of populations from depleted-uranium-contaminated regions

International Nuclear Information System (INIS)

Milacic, Snezana; Petrovic, Dragana; Jovicic, Dubravka; Kovacevic, Radomir; Simic, Jadranko

2004-01-01

During the NATO air strikes on the Federal Republic of Yugoslavia (Serbia and Montenegro) in 1999, depleted-uranium ammunition was used on 112 locations, mainly Kosovo, in the south of Serbia, and one location in Montenegro. Blood samples of residents from depleted-uranium-contaminated areas were gathered and blood cell and chromosomal aberrations were analyzed. During the last 3 years blood samples from 21 residents of Kosovo (Strpce), from 29 residents from the south of Serbia (the Vranje and Bujanovac regions), and from 19 technical television workers from the site of Pljackovica, in the vicinity of Vranje, were collected. Blood samples from 33 residents of central Serbia and 46 occupational workers exposed to X-rays were used as controls. All subjects studied were without any clinical symptoms of disease. The examinations included general clinical assessment; urine samples for α-and γ-spectrometry analysis; complete blood counts; ratio-percentages of blood cells in stained (Giemsa) capillary smears, individual leukocyte line elements; morphological changes observed under a microscope; the presence of immature forms or blasts; and leukocyte enzyme activity [alkaline phosphatase leukocyte (APL)]. Chromosomal aberrations were evaluated in 200 peripheral blood lymphocytes in mitosis. An increased incidence of rogue cells and chromosomal aberrations was found in the blood of the residents of Vranje and Bujanovac, but this was below the incidence of chromosomal aberrations in individuals occupationally exposed to ionizing irradiation. Blast cells were not found. Blood counts were decreased in only a few samples, while morphological changes of both nuclei and cytoplasm were marked in individuals in south and central Serbia. Enzymatic activity (as measured by the APL score) was decreased in samples with chromosomal aberrations and cyto-morphological changes in subjects from the south of Serbia. The contamination level measured by this examination was low. Because of

Multiple inorganic toxic substances contaminating the groundwater of Myingyan Township, Myanmar: Arsenic, manganese, fluoride, iron, and uranium

Energy Technology Data Exchange (ETDEWEB)

Bacquart, Thomas [Better Life Laboratories, Calais, VT (United States); Frisbie, Seth [Better Life Laboratories, Calais, VT (United States); Department of Chemistry and Biochemistry, Norwich University, Northfield, VT (United States); Mitchell, Erika [Better Life Laboratories, Calais, VT (United States); Grigg, Laurie [Department of Earth and Environmental Science, Norwich University, Northfield, VT (United States); Cole, Christopher [Department of Chemistry and Biochemistry, Norwich University, Northfield, VT (United States); Small, Colleen [Vermont Department of Health Laboratory, Burlington, VT (United States); Sarkar, Bibudhendra, E-mail: bsarkar@sickkids.ca [Department of Molecular Structure and Function, The Research Institute of The Hospital for Sick Children, University of Toronto, Toronto, Ontario (Canada); Department of Biochemistry, University of Toronto, Toronto, Ontario (Canada)

2015-06-01

In South Asia, the technological and societal shift from drinking surface water to groundwater has resulted in a great reduction of acute diseases due to water borne pathogens. However, arsenic and other naturally occurring inorganic toxic substances present in groundwater in the region have been linked to a variety of chronic diseases, including cancers, heart disease, and neurological problems. Due to the highly specific symptoms of chronic arsenic poisoning, arsenic was the first inorganic toxic substance to be noticed at unsafe levels in the groundwater of West Bengal, India and Bangladesh. Subsequently, other inorganic toxic substances, including manganese, uranium, and fluoride have been found at unsafe levels in groundwater in South Asia. While numerous drinking water wells throughout Myanmar have been tested for arsenic, relatively little is known about the concentrations of other inorganic toxic substances in Myanmar groundwater. In this study, we analyzed samples from 18 drinking water wells (12 in Myingyan City and 6 in nearby Tha Pyay Thar Village) and 2 locations in the Ayeyarwaddy River for arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, fluoride, iron, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, uranium, vanadium, and zinc. Concentrations of arsenic, manganese, fluoride, iron, or uranium exceeded health-based reference values in most wells. In addition, any given well usually contained more than one toxic substance at unsafe concentrations. While water testing and well sharing could reduce health risks, none of the wells sampled provide water that is entirely safe with respect to inorganic toxic substances. It is imperative that users of these wells, and users of other wells that have not been tested for multiple inorganic toxic substances throughout the region, be informed of the need for drinking water testing and the health consequences of drinking water contaminated with inorganic toxic

Multiple inorganic toxic substances contaminating the groundwater of Myingyan Township, Myanmar: Arsenic, manganese, fluoride, iron, and uranium

International Nuclear Information System (INIS)

Bacquart, Thomas; Frisbie, Seth; Mitchell, Erika; Grigg, Laurie; Cole, Christopher; Small, Colleen; Sarkar, Bibudhendra

2015-01-01

In South Asia, the technological and societal shift from drinking surface water to groundwater has resulted in a great reduction of acute diseases due to water borne pathogens. However, arsenic and other naturally occurring inorganic toxic substances present in groundwater in the region have been linked to a variety of chronic diseases, including cancers, heart disease, and neurological problems. Due to the highly specific symptoms of chronic arsenic poisoning, arsenic was the first inorganic toxic substance to be noticed at unsafe levels in the groundwater of West Bengal, India and Bangladesh. Subsequently, other inorganic toxic substances, including manganese, uranium, and fluoride have been found at unsafe levels in groundwater in South Asia. While numerous drinking water wells throughout Myanmar have been tested for arsenic, relatively little is known about the concentrations of other inorganic toxic substances in Myanmar groundwater. In this study, we analyzed samples from 18 drinking water wells (12 in Myingyan City and 6 in nearby Tha Pyay Thar Village) and 2 locations in the Ayeyarwaddy River for arsenic, boron, barium, beryllium, cadmium, cobalt, chromium, copper, fluoride, iron, mercury, manganese, molybdenum, nickel, lead, antimony, selenium, thallium, uranium, vanadium, and zinc. Concentrations of arsenic, manganese, fluoride, iron, or uranium exceeded health-based reference values in most wells. In addition, any given well usually contained more than one toxic substance at unsafe concentrations. While water testing and well sharing could reduce health risks, none of the wells sampled provide water that is entirely safe with respect to inorganic toxic substances. It is imperative that users of these wells, and users of other wells that have not been tested for multiple inorganic toxic substances throughout the region, be informed of the need for drinking water testing and the health consequences of drinking water contaminated with inorganic toxic

Anaerobic U(IV) Bio-oxidation and the Resultant Remobilization of Uranium in Contaminated Sediments

International Nuclear Information System (INIS)

Coates, John D.

2005-01-01

A proposed strategy for the remediation of uranium (U) contaminated sites is based on immobilizing U by reducing the oxidized soluble U, U(VI), to form a reduced insoluble end product, U(IV). Due to the use of nitric acid in the processing of nuclear fuels, nitrate is often a co-contaminant found in many of the environments contaminated with uranium. Recent studies indicate that nitrate inhibits U(VI) reduction in sediment slurries. However, the mechanism responsible for the apparent inhibition of U(VI) reduction is unknown, i.e. preferential utilization of nitrate as an electron acceptor, direct biological oxidation of U(IV) coupled to nitrate reduction, and/or abiotic oxidation by intermediates of nitrate reduction. Recent studies indicates that direct biological oxidation of U(IV) coupled to nitrate reduction may exist in situ, however, to date no organisms have been identified that can grow by this metabolism. In an effort to evaluate the potential for nitrate-dependent bio-oxidation of U(IV) in anaerobic sedimentary environments, we have initiated the enumeration of nitrate-dependent U(IV) oxidizing bacteria. Sediments, soils, and groundwater from uranium (U) contaminated sites, including subsurface sediments from the NABIR Field Research Center (FRC), as well as uncontaminated sites, including subsurface sediments from the NABIR FRC and Longhorn Army Ammunition Plant, Texas, lake sediments, and agricultural field soil, sites served as the inoculum source. Enumeration of the nitrate-dependent U(IV) oxidizing microbial population in sedimentary environments by most probable number technique have revealed sedimentary microbial populations ranging from 9.3 x 101 - 2.4 x 103 cells (g sediment)-1 in both contaminated and uncontaminated sites. Interestingly uncontaminated subsurface sediments (NABIR FRC Background core FB618 and Longhorn Texas Core BH2-18) both harbored the most numerous nitrate-dependent U(IV) oxidizing population 2.4 x 103 cells (g sediment)-1

Electrocoagulation applied to the decontamination of stainless steel parts contaminated with uranium

International Nuclear Information System (INIS)

Pujol P, A. A.; Monroy G, F.; Bustos B, E.

2017-09-01

The decontamination of non-compact able radioactive waste, such as tools and equipment, has the purpose of removing surface radioactive waste from waste, in order to reduce its volume to be conditioned and stored. The application of treatment techniques based on electrochemistry, such as electro-coagulation (Ec) in the decontamination of waste or non-compact able radioactive materials of stainless steel containing uranium, was studied in the present work and its technical feasibility was evaluated. For this, tests were carried out, first with stainless steel plates coated with WO 3 , to simulate a fixed contamination and to determine the best conditions of tungsten removal by Ec as: ph, support electrolyte, cell potential, type of counter electrode material and distance between the anode/cathode electrodes. In addition, different arrangements of configurations were tested for a rectangular acrylic cell and for a circular configuration cell, using flat plate electrodes and cylindrical electrodes to perform the removal process of the contaminant with the best conditions. In the case of the Ec, the mechanism that occurs is an electrodisolution of the iron plate, with the release of oxygen at the anode and detachment of the WO 3 layer, all the material passing to the solution with the formation of iron hydroxides. Subsequently, from the best experimental conditions to remove WO 3 , UO 2 (NO 3 ) 2 was used as radioactive contaminant to evaluate the feasibility of the decontamination process. Removal efficiencies of 90% uranium were obtained in 1 hour, ph = 1, using a molar solution of H 2 SO 4 as support electrolyte and potential of 2.4 V. Finally, after testing the different electrochemical cell (Ec) arrays at the laboratory level, radioactive decontamination of real pieces contaminated with U-238 was performed using the circular configuration arrangement under the best experimental conditions previously determined. (Author)

Bacterial endophytes enhance phytostabilization in soils contaminated with uranium and lead.

Science.gov (United States)

Ahsan, Muhammad Tayyab; Najam-Ul-Haq, Muhammad; Idrees, Muhammad; Ullah, Inayat; Afzal, Muhammad

2017-10-03

The combined use of plants and bacteria is a promising approach for the remediation of polluted soil. In the current study, the potential of bacterial endophytes in partnership with Leptochloa fusca (L.) Kunth was evaluated for the remediation of uranium (U)- and lead (Pb)-contaminated soil. L. fusca was vegetated in contaminated soil and inoculated with three different endophytic bacterial strains, Pantoea stewartii ASI11, Enterobacter sp. HU38, and Microbacterium arborescens HU33, individually as well as in combination. The results showed that the L. fusca can grow in the contaminated soil. Bacterial inoculation improved plant growth and phytoremediation capacity: this manifested in the form of a 22-51% increase in root length, 25-62% increase in shoot height, 10-21% increase in chlorophyll content, and 17-59% more plant biomass in U- and Pb-contaminated soils as compared to plants without bacterial inoculation. Although L. fusca plants showed potential to accumulate U and Pb in their root and shoot on their own, bacterial consortia further enhanced metal uptake capacity by 53-88% for U and 58-97% for Pb. Our results indicate that the combination of L. fusca and endophytic bacterial consortia can effectively be used for the phytostabilization of both U- and Pb-contaminated soils.

Laboratory evaluation of the hydrogen sulfide gas treatment approach for remediation of chromate-, uranium(VI)-, and nitrate-contaminated soils

International Nuclear Information System (INIS)

Thornton, E.C.; Baechler, M.A.; Beck, M.A.; Amonette, J.E.

1994-08-01

Bench-scale soil treatment tests were conducted as part of an effort to develop and implement an in situ chemical treatment approach to the remediation of metal and radionuclide contaminated soils through the use of reactive gases. In general, > 90% immobilization of chromium and > 50% immobilization of uranium was achieved. Leach test results indicate that the treatment process is irreversible for chromium but partially reversible for uranium indicates that immobilization for this contaminant is more readily achieved in organic rich soils. This observation is ascribed to the reducing nature of organic matter. Additional tests were also conducted with soils contaminated to the 5,000 ppm level with nitrate. Nitrate was not found to interfere significantly with treatment of the contaminants. Nitrite was observed in the leachate samples obtained from tests with an organic-rich soil containing clay, however. Leachate chemistries suggested that no other significantly hazardous byproducts were generated by the treatment process and that soil alteration effects were minimal. Test results also suggest that treatment effectiveness is somewhat lower in very dry soils but still able to immobilize chromium and uranium to an acceptable degree. Results of these testing activities indicate that the concentration of hydrogen sulfide in the gas mixture is not a limited factor in treatment as long as a sufficient volume of the mixture is delivered to the soil to achieve a mole ratio of hydrogen sulfide to contaminant of at least 10

A study of a zone approach to IAEA (International Atomic Energy Agency) safeguards: The low-enriched-uranium zone of a light-water-reactor fuel cycle

Energy Technology Data Exchange (ETDEWEB)

Fishbone, L.G.; Higinbotham, W.A.

1986-06-01

At present the IAEA designs its safeguards approach with regard to each type of nuclear facility so that the safeguards activities and effort are essentially the same for a given type and size of nuclear facility wherever it may be located. Conclusions regarding a state are derived by combining the conclusions regarding the effectiveness of safeguards for the individual facilities within a state. In this study it was convenient to define three zones in a state with a closed light-water-reactor nuclear fuel cycle. Each zone contains those facilities or parts thereof which use or process nuclear materials of the same safeguards significance: low-enriched uranium, radioactive spent fuel, or recovered plutonium. The possibility that each zone might be treated as an extended material balance area for safeguards purposes is under investigation. The approach includes defining the relevant features of the facilities in the three zones and listing the safeguards activities which are now practiced. This study has focussed on the fresh-fuel zone, the several facilities of which use or process low-enriched uranium. At one extreme, flows and inventories would be verified at each material balance area. At the other extreme, the flows into and out of the zone and the inventory of the whole zone would be verified. There are a number of possible safeguards approaches which fall between the two extremes. The intention is to develop a rational approach which will make it possible to compare the technical effectiveness and the inspection effort for the facility-oriented approach, for the approach involving the zone as a material balance area, and for some reasonable intermediate safeguards approaches.

A study of a zone approach to IAEA [International Atomic Energy Agency] safeguards: The low-enriched-uranium zone of a light-water-reactor fuel cycle

International Nuclear Information System (INIS)

Fishbone, L.G.; Higinbotham, W.A.

1986-06-01

At present the IAEA designs its safeguards approach with regard to each type of nuclear facility so that the safeguards activities and effort are essentially the same for a given type and size of nuclear facility wherever it may be located. Conclusions regarding a state are derived by combining the conclusions regarding the effectiveness of safeguards for the individual facilities within a state. In this study it was convenient to define three zones in a state with a closed light-water-reactor nuclear fuel cycle. Each zone contains those facilities or parts thereof which use or process nuclear materials of the same safeguards significance: low-enriched uranium, radioactive spent fuel, or recovered plutonium. The possibility that each zone might be treated as an extended material balance area for safeguards purposes is under investigation. The approach includes defining the relevant features of the facilities in the three zones and listing the safeguards activities which are now practiced. This study has focussed on the fresh-fuel zone, the several facilities of which use or process low-enriched uranium. At one extreme, flows and inventories would be verified at each material balance area. At the other extreme, the flows into and out of the zone and the inventory of the whole zone would be verified. There are a number of possible safeguards approaches which fall between the two extremes. The intention is to develop a rational approach which will make it possible to compare the technical effectiveness and the inspection effort for the facility-oriented approach, for the approach involving the zone as a material balance area, and for some reasonable intermediate safeguards approaches

Development of apparatus for surveying uranium surface contamination quantity

International Nuclear Information System (INIS)

Wang Qingheng; Han Jingquan

1994-11-01

An apparatus for measuring uranium contamination of the surface of reactor plate component is described. The searching unit of the apparatus is a large surface multi-wire proportional counter. The cathode of the counter is made of stainless steel with low radioactive background, the window is made of film which is plated with aluminum about 6 μm; and the anode is mad by gild tungsten wire of 0.025 mm diameter. The sensitive area of the counter is 1113 mm x 100 mm. It has been shown that the intrinsic radioactive background of the apparatus is 0.002 cpm/cm 2 (2 count/min). The detecting efficiency is 67% for enriched uranium source (2π solid angle). The stability is 0.84% within 24 hour (including detector, high voltage power supply, amplifier, discriminator, computer, type and display system). The lower detection limit of the apparatus is 4.6 x 10 -10 g/cm 2 (for 20% 235 U, 0.13% 234 U, 79.64% 238 U). The apparatus can present timing by a computer controlling, and it also has the following functions: displaying, automatic alarming, classifying and typing the results. (2 tabs., 7 figs.)

A review of the environmental behavior of uranium derived from depleted uranium alloy penetrators

Energy Technology Data Exchange (ETDEWEB)

Erikson, R.L.; Hostetler, C.J.; Divine, J.R.; Price, K.R.

1990-01-01

The use of depleted uranium (DU) penetrators as armor-piercing projectiles in the field results in the release of uranium into the environment. Elevated levels of uranium in the environment are of concern because of radioactivity and chemical toxicity. In addition to the direct contamination of the soil with uranium, the penetrators will also chemically react with rainwater and surface water. Uranium may be oxidized and leached into surface water or groundwater and may subsequently be transported. In this report, we review some of the factors affecting the oxidation of the DU metal and the factors influencing the leaching and mobility of uranium through surface water and groundwater pathways, and the uptake of uranium by plants growing in contaminated soils. 29 refs., 10 figs., 3 tabs.

Remediation of uranium-contaminated soil using the Segmented Gate System and containerized vat leaching techniques: a cost effectiveness study

International Nuclear Information System (INIS)

Cummings, M.; Booth, S.R.

1996-01-01

Because it is difficult to characterize heterogeneously contaminated soils in detail and to excavate such soils precisely using heavy equipment, it is common for large quantities of uncontaminated soil to be removed during excavation of contaminated sites. Until now, volume reduction of radioactively contaminated soil depended upon manual screening and analysis of samples, a costly and impractical approach, particularly with large volumes of heterogeneously contaminated soil. The baseline approach for the remediation of soils containing radioactive waste is excavation, pretreatment, containerization, and disposal at a federally permitted landfill. However, disposal of low-level radioactive waste is expensive and storage capacity is limited. ThermoNuclean's Segmented Gate System (SGS) removes only the radioactively contaminated soil, in turn greatly reducing the volume of soils that requires disposal. After processing using the SGS, the fraction of contaminated soil is processed using the containerized vat leaching (CVL) system developed at LANL. Uranium is leached out of the soil in solution. The uranium is recovered with an ion exchange resin, leaving only a small volume of liquid low-level waste requiring disposal. The reclaimed soil can be returned to its original location after treatment with CVL

Multi-metal contamination with uranium trend impact on aquatic environment and consequences for fish immune system and adaptive responses

Energy Technology Data Exchange (ETDEWEB)

Le Guernic, A.; Gagnaire, B. [IRSN/PRP-ENV/SERIS/LECO (France); Sanchez, W. [Institut national de l' environnement industriel et des risques - INERIS (France); Betoulle, S. [Champagne Ardenne University (France)

2014-07-01

Human activities have conducted to an increase of concentrations of various metals in aquatic ecosystems, including uranium. Its extraction and use have been rapidly magnified because of its role in the nuclear fuel cycle. These activities have led to high concentrations of uranium in the aquatic environment and thus a potential risk to exposed organisms, including fish. Consequences can be observed through metabolic and physiological responses, called biomarkers. Some biomarkers are interesting in order to evaluate the effects of metal contamination, among other immunotoxicity markers, antioxidant defenses and genotoxicity. The aims of this study are: i) to investigate the effects of a multi-metal contamination on a fish, the three-spined stickleback, Gasterosteus aculeatus, and ii) to observe the adaptive capacity of fish due to a combination of stress (chemical stress and biological stress). To meet the first objective, six water bodies (ponds and lakes) located in two departments (Cantal and Haute-Vienne, France) were chosen according to their proximity to old uranium mines and to their levels of metal contamination related to chemical processes appeared during extraction. 240 three-spined sticklebacks were caged for 28 days in the six selected sites. A battery of biomarkers was measured in fish sampled after 14 and 28 of caging. The results for the Haute-Vienne department showed that caged fish in the pond with the highest uranium concentration (20 μg.L{sup -1}) presented the most DNA damage after 14 days of caging. Leukocyte phagocytosis (marker of immunotoxicity) of caged fish in this pond was lower at 14 days and greater at 28 days compared to other ponds without uranium. The multi-metal contamination negatively affected other parameters such as the condition index, oxidative activity, viability of lysosomal membrane and leukocytes distribution. In order to study the response of fish to a combined stress (chemical + biological) (objective ii), a second

Biotransformations Involved in Sustained Reductive Removal of Uranium in Contaminated Aquifers. Final report

International Nuclear Information System (INIS)

Lovley, Derek R.

2008-01-01

The studies completed under this grant significantly advanced the understanding and design of strategies for in situ uranium bioremediation. Novel strategies identified show promise to make in situ uranium bioremediation technically simpler and less expensive. As detailed, important findings included: (1) Development of an electron donor delivery strategy to prolong the in situ activity of Geobacter species and enhance the removal of uranium from the groundwater; (2) Demonstration that reproducible year-to-year field experiments were possible at the ERSP study site in Rifle, CO, making hypothesis-driven field experimentation possible; (3) Elucidation of the geochemical and microbiological heterogeneities with the subsurface during in situ uranium bioremediation, which must be accounted for to accurately model the bioremediation process; (4) The discovery that most of the U(VI) contamination at the Rifle site is sediment-associated rather than mobile in the groundwater, as previously considered; (5) The finding that unlike soluble U(VI), sediment-associated U(VI) is not microbially reducible; (6) The demonstration that electrodes may be an effective alternative to acetate as an electron donor to promote microbial U(VI) reduction in the subsurface with the added benefit that electrode-promoted microbial U(VI) reduction offers the possibility of removing the immobilized uranium from the subsurface; and (7) The finding that, after extended acetate inputs, U(VI) continues to be removed from groundwater long after the introduction of acetate into the subsurface is terminated and that this appears to be due to adsorption onto biomass. This potentially will make in situ uranium bioremediation much less expensive than previously envisioned.

Depleted uranium internal contamination of US soldiers deployed in Samawah, Iraq during operation Iraqi freedom

International Nuclear Information System (INIS)

Asaf Durakovic; Isaac Zimmerman; Axel Gerdes

2004-01-01

Purpose: The purpose of this study was to analyze the concentration and precise isotopic composition and ratios of four uranium isotopes ( 234 U, 235 U, 236 U, and 238 U) in the urine of United States soldiers deployed in Samawah, Iraq during the second Gulf War. Methods: Seven active duty US soldiers deployed as military police unit 442 presenting with non-specific symptoms of intractable headaches, excessive fatigue, intermittent fevers, musculoskeletal pains, respiratory impairment, affect changes, urinary tract symptoms, and neurological alterations were clinically evaluated. Each soldier signed a consent form to participate in our study. The collection of 24-hour urine samples of each subject was performed under controlled conditions. The urine samples were personally carried to the laboratory of the Institute of Geochemistry, JW Goethe University, Frankfurt, Germany. Each sample was analyzed in duplicate by multicollector inductively coupled plasma ionization mass spectrometry (MC-ICP-MS). Control samples consisting of an internal urine standard were also analyzed by the same procedure. The analytical methodology included pre-concentration of the urine samples using evaporation, oxidation of organic matter, uranium purification by ion-exchange chromatography, and analysis by mass spectrometry. The final analysis of the specimens was performed by using a double-focusing Thermo Finnigan Neptune multicollector ICP-MS equipped with retarding potential quadrupole lens and a secondary electron multiplier for ion counting. Results: The mean concentration of total uranium was 3.6±1.3 ng/L. The average 238 U/ 235 U ratio was 146.2±10.2. The ratio of 238 U/ 235 U, being considered as the single most important parameter in determining the quantitative state of depletion of the natural uranium ratio, demonstrates a significant internal contamination with depleted uranium in four soldiers. The 234 U/ 238 U ratio was 6.5 x 10 -5 ±5.7 x 10 -6 . The 236 U/ 238 U ratio was

Remote sensing technology prospecting methods of interlayer oxidation zone type sandstone uranium deposit in Yili basin

International Nuclear Information System (INIS)

Huang Xianfang; Huang Shutao; Pan Wei; Feng Jie; Liu Dechang; Zhang Jingbo; Xuan Yanxiu; Rui Benshan

1998-12-01

Taking Yili Basin as an example, remote sensing technology and method of interlayer oxidation zone type sandstone uranium deposit have systematically been summarized. Firstly, principle, methods and procedures of the second development of scientific experimental satellite photograph have been elaborated in detail. Three dimensional stereo simulation, display, and multi-parameters extraction have been recommended. Secondarily, the research is focused on prospective section image features in different type images and their geological implications and on establishing recognition keys of promising areas. Finally, based on above research results, three graded predictions, i.e. regional prospect, promising sections and favourable location in the deposit have been made step by step and reconnaissance and prospecting range are gradually reduced. The practice has indicated that breakthrough progress has been made in application to prospect prognosis of interlayer oxidation zone type sandstone uranium deposit and good verified results have been obtained

In situ vadose zone remediation of petroleum-contaminated soils

International Nuclear Information System (INIS)

Greacen, J.R.; Finkel, D.J.

1991-01-01

This paper discusses a pilot-scale system treating vadose zone soils contaminated with petroleum products constructed and operated at a former petroleum bulk storage terminal in New England. A site investigation following decommissioning activities identified more than 100,000 yds of soil at the site contaminated by both No. 2 fuel oil and gasoline. Soil cleanup criteria of 50 ppm TPH and 0.25 ppm BTEX were established. A pilot-scale treatment unit with dimensions of 125 ft x 125 ft x 6 ft was constructed to evaluate the potential for in situ treatment of vadose zone soils. Contaminant levels in pilot cell soils ranged from 0 to 5,250 ppm TPH and 0.0 to 4.2 ppm BTEX. Two soil treatment methods n the pilot system were implemented; venting to treat the lighter petroleum fractions and bioremediation to treat the nonvolatile petroleum constituents. Seven soil gas probes were installed to monitor pressure and soil gas vapor concentrations in the subsurface. Changes in soil gas oxygen and carbon dioxide concentrations were used as an indirect measure of enhanced bioremediation of pilot cell soils. After operating the system for a period of 2.5 months, soil BTEX concentrations were reduced to concentrations below the remediation criteria for the site

Summary of Vadose -- Zone Conceptual Models for Flow and Contaminant Transport and 1999 - 2003 Progress on Resolving Deficiencies in Understanding the Vadose Zone at the INEEL

Energy Technology Data Exchange (ETDEWEB)

Robert C. Starr; Dana L. Dettmers; Brennon R. Orr; Thomas R. Wood

2003-12-01

The thick vadose zone that underlies the Idaho National Engineering and Environmental Laboratory has been recognized both as an avenue through which contaminants disposed at or near the ground surface can migrate to groundwater in the underlying Eastern Snake River Plain aquifer, and as a barrier to the movement of contaminants into the aquifer. Flow and contaminant transport in the vadose zone at the INEEL is complicated by the highly heterogeneous nature of the geologic framework and by the variations in the behavior of different contaminants in the subsurface. The state of knowledge concerning flow and contaminant transport in the vadose zone at and near the INEEL IN 1999 was summarized in Deficiencies in Vadose Zone Understanding at the Idaho National Engineering and Environmental Laboratory (Wood et al., 2000). These authors identified deficiencies in knowledge of flow and contaminant transport processes in the vadose zone, and provided recommendations for additional work that should be conducted to address these deficiencies. In the period since (Wood et al., 2000) was prepared, research has been published that, to some degree, address these deficiencies. This document provides a bibliography of reports, journal articles, and conference proceedings published 1999 through mid-2003 that are relevant to the vadose zone at or near the INEEL and provides a brief description of each work. Publications that address specific deficiencies or recommendations are identified, and pertinent information from selected publications is presented.

Remediation of a uranium-contaminated quarry utilizing submersible, remotely operated vehicles

International Nuclear Information System (INIS)

Fleming, K.N.

1992-01-01

The Kerr Hollow Quarry (KHQ) Disposal Site on the Oak Ridge (Tennessee) Reservation was previously used to treat and dispose of pyrophoric and water-reactive wastes contaminated with small quantities of radioactive materials (almost exclusively uranium and uranium daughters) from processes at the Department of Energy-owned, Oak Ridge Y-12 Plant and Oak Ridge National Laboratory. This paper describes remediation techniques utilizing a small, remotely operated submarine with an attached camera to visually locate waste containers, determine whether containers have been breached, transport small containers, and direct a larger remotely operated grappling machine to move larger waste for shredding operations. Most of the solid waste is reduced under water by a metal shredder. Non-shreddable items (e. g. , gas cylinders and larger structures) are mechanically breached under water to allow the contents to fully react. The waste is then removed from the water, monitored, the material is segregated, and transported to a temporary waste storage area until disposal

Ion exchange technology in the remediation of uranium contaminated groundwater at Fernald

International Nuclear Information System (INIS)

Sutton, Chris; Glassmeyer, Cathy; Bozich, Steve

2000-01-01

Using pump and treat methodology, uranium contaminated groundwater is being removed from the Great Miami Aquifer at the Fernald Environmental Management Project (FEMP) per the FEMP Record of Decision (ROD) that defines groundwater cleanup. Standard extraction wells pump about 3900 gallons-per-minute (gpm) from the aquifer through five ion exchange treatment systems. The largest treatment system k the Advanced Wastewater Treatment (AWWT) Expansion System with a capacity of 1800 gpm, which consists of three trains of two vessels. The trains operate in parallel treating 600 gpm each, The two vessels in each train operate in series, one in lead and one in lag. Treated groundwater is either reinfected back into the aquifer to speed up the aquifer cleanup processor discharged to the Great Miami River. The uranium regulatory ROD limit for discharge to the river is 20 parts per billion (ppb), and the FEMP uranium administrative action level for reinfection is 10 ppb. Spent (i.e., a resin that no longer adsorbs uranium) ion exchange resins must either be replaced or regenerated. The regeneration of spent ion exchange resins is considerably more cost effective than their replacement. Therefore, a project was undertaken to learn how best to regenerate the resins in the groundwater vessels. At the outset of this project, considerable uncertainty existed as to whether a spent resin could be regenerated successfully enough so that it performed as well as new resin relative to achieving very low uranium concentrations in the effluent. A second major uncertain y was whether the operational lifetime of a regenerated resin would be similar to that of a new resin with respect to uranium loading capacity and effluent concentration behavior. The project was successful in that a method for regenerating resins has been developed that is operationally efficient, that results in regenerated resins yielding uranium concentrations much lower than regulatory limits, and that results in

Perched-Water Evaluation for the Deep Vadose Zone Beneath the B, BX, and BY Tank Farms Area of the Hanford Site

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J.; Oostrom, Martinus; Carroll, KC; Chronister, Glen B.

2013-06-28

Perched-water conditions have been observed in the vadose zone above a fine-grained zone that is located a few meters above the water table within the B, BX, and BY Tank Farms area. The perched water contains elevated concentrations of uranium and technetium-99. This perched-water zone is important to consider in evaluating the future flux of contaminated water into the groundwater. The study described in this report was conducted to examine the perched-water conditions and quantitatively evaluate 1) factors that control perching behavior, 2) contaminant flux toward groundwater, and 3) associated groundwater impact.

Biotransformation involved in sustained reductive removal of uranium in contaminant aquifers

International Nuclear Information System (INIS)

Lovley, Derek R.

2005-01-01

This report summarizes progress made from August 2004 to July 2005. During this period research focused primarily on obtaining a better understanding of the factors controlling the reduction of U(VI) during in situ uranium bioremediation as well as investigating the potential for using electrodes as an alternative electron donor to promote in situ uranium reduction. Analysis of the 2003 experiment at the field study site in Rifle, CO was completed. The results demonstrated the substantial heterogeneity of the zone undergoing bioremediation, both in terms of geochemistry and microbiology. The lack of U(VI) reduction under sulfate-reducing conditions was clearly documented. The need for more detailed sampling both with time and with depth in the aquifer was demonstrated. For the first time a comparison between the composition of the microbial community in the sediments and the microbes in the corresponding groundwater was attempted. The findings from this study are important not only in further demonstrating the potential for in situ uranium bioremediation, but also for indicating how methods and sampling approaches should be improved in the future. A manuscript summarizing these findings has been accepted for publication in Applied and Environmental Microbiology. In summer of 2004 a new field experiment was conducted at the Rifle site. A novel feature of this study was much more intensive sampling in order to better define the progression of microbial processes during in situ uranium bioremediation. The results demonstrated that stimulation of in situ uranium bioremediation with added acetate was a repeatable phenomenon and that U(VI) reduction was clearly linked to the presence and activity of microorganisms in the family Geobacteraceae. A manuscript summarizing these results is in preparation. A surprising result of the field studies at the Rifle site was that although Geobacter species actively reduced U(VI) in the groundwater, removing it from solution, a high

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

International Nuclear Information System (INIS)

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

1975-01-01

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

Uranium removal from the water supply

International Nuclear Information System (INIS)

Miranzadeh, Mohammad Bagher.

1996-01-01

Uranium can be naturally occurring radionuclides that contaminate some potable water supplies. Uranium is found both in surface water and ground water supplies. The United States Environmental Protection Agency recently proposed a maximum contaminant of 20 micro gram/liter for uranium because of concerns about its association with kidney disease and cancer. uranium can be removed from the supply by strong base anion-resin. Exhausted resin is regenerated by sodium chloride solution. (Author)

Experience in studying of the iron mineralogy in the oxidation zone of uranium deposits by physical methods

International Nuclear Information System (INIS)

Kochenov, A.V.; Dobrovol'skaya, N.V.; Zajtseva, G.M.; Korovushkin, V.V.; Moiseev, V.M.; Yakubovskaya, N.Yu.

1977-01-01

Possibilities are considered of increasing the reliability of the diagnostics and the resolving power of the procedure for the determination of the minaral forms and percentage of iron oxides and hydroxides in the oxidized zone of uranium deposits using a combination of methods of nuclear gamma resonance, thermomagnetic analysis and the Faraday method. The apparatus used included a YaGRS-4 spectrometer in combination with an AI-236 analyzer and a vibration magnetometer. The essence of the methods and of the procedure of analyses is presented. Parameters of reference samples of goethite, maghemite, etc. which emerged from their analysis by the above combination of methods are given. The established diagnostic features have been used in the study of iron mineralogy of oxidized zones, uranium deposits of sedimantarycoal and sandstone types, as well as crusts of weathering of sedimentary rocks. It has been found that in zone of epigenetically altered rocks iron minerals are of mixed multicomponent composition reflecting the fact that the processes of formation of oxidized zones are multistage and not unidirectional in character. The procedure proposed allows one to diagnose finely dispersed, roentgenoamorphous or poorly crystallized minerals, to discover ferruginous minerals in complex multiphase systems and determine their percentages

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

International Nuclear Information System (INIS)

Lee, Minhee; Yang, Minjune

2010-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

Lee, Minhee, E-mail: heelee@pknu.ac.kr [Department of Environmental Geosciences, Pukyong National University, 599-1 Daeyondong, Namgu, Busan 608-737 (Korea, Republic of); Yang, Minjune [Department of Environmental Geosciences, Pukyong National University, 599-1 Daeyondong, Namgu, Busan 608-737 (Korea, Republic of)

2010-01-15

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

Uranium-bearing wastes and their radon emanation

International Nuclear Information System (INIS)

Sasaki, Tomozo; Imamura, Mitsutaka; Gunji, Yasuyoshi

2007-01-01

There are no data available with regard to radon emanation coefficients for uranium-bearing wastes; such data are needed for the assessment of radiation exposure from radon that will be generated in the distant future as one uranium progeny at shallow land disposal sites for uranium-bearing wastes. There are many kinds of uranium-bearing wastes. However, it is not necessary to measure the radon emanation coefficients for all of them for two reasons. First, the radon emanation coefficients for uranium-bearing wastes contaminated by dissolved uranium are determined by the uranium chemical form, the manner of uranium deposition on the waste matrix, and the size of the particles which constitute the waste matrix. Therefore, only a few representative measurements are sufficient for such uranium-bearing wastes. Second, it is possible to make theoretical calculations of radon emanation coefficients for uranium-bearing wastes contaminated by UO 2 particles before sintering. In the present study, simulated uranium-bearing wastes contaminated by dissolved uranium were prepared, their radon emanation coefficients were measured and radon emanation coefficients were calculated theoretically for uranium-bearing wastes contaminated by UO 2 particles before sintering. The obtained radon emanation coefficients are distributed at higher values than those for ubiquitous soils and rocks in the natural environment. Therefore, it is not correct to just compare uranium concentrations among uranium-bearing wastes, ubiquitous soils and rocks in terms of radiation exposure. The radon emanation coefficients obtained in the present study have to be employed together with the uranium concentration in uranium-bearing wastes in order to achieve proper assessment of radiation exposure. (author)

Evaluating Contaminant Flux from the Vadose Zone to the Groundwater in the Hanford Central Plateau. SX Tank Farms Case Study

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Oostrom, Martinus [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Last, George V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Tartakovsky, Guzel D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2015-09-01

At the DOE Hanford Site, contaminants were discharged to the subsurface through engineered waste sites in the Hanford Central Plateau. Additional waste was released through waste storage tank leaks. Much of the contaminant inventory is still present within the unsaturated vadose zone sediments. The nature and extent of future groundwater contaminant plumes and the growth or decline of current groundwater plumes beneath the Hanford Central Plateau are a function of the contaminant flux from the vadose zone to the groundwater. In general, contaminant transport is slow through the vadose zone and it is difficult to directly measure contaminant flux in the vadose zone. Predictive analysis, supported by site characterization and monitoring data, was applied using a structured, systems-based approach to estimate the future contaminant flux to groundwater in support of remediation decisions for the vadose zone and groundwater (Truex and Carroll 2013). The SX Tank Farm was used as a case study because of the existing contaminant inventory in the vadose zone, observations of elevated moisture content in portions of the vadose zone, presence of a limited-extent groundwater plume, and the relatively large amount and wide variety of data available for the site. Although the SX Tank Farm case study is most representative of conditions at tank farm sites, the study has elements that are also relevant to other types of disposal sites in the Hanford Central Plateau.

Fate of Uranium in Wetlands: Impact of Drought Followed by Re-flooding

Science.gov (United States)

Gilson, E.; Huang, S.; Koster van Groos, P. G.; Scheckel, K.; Peacock, A. D.; Kaplan, D. I.; Jaffe, P. R.

2014-12-01

Uranium contamination in groundwater can be mitigated in anoxic zones by iron-reducing bacteria that reduce soluble U(VI) to insoluble U(IV) and by uranium immobilization through complexation and sorption. Wetlands often link ground and surface-waters, making them strategic systems for potentially limiting migration of uranium contamination. Little is known about how drought periods that result in the drying of wetland soils, and consequent redox changes, affect uranium fate and transport in wetlands. In order to better understand the fate and stability of immobilized uranium in wetland soils, and how dry periods affect the uranium stability, we dosed saturated wetland mesocosms planted with Scirpus acutus with low levels of uranyl-acetate for 5 months before imposing a 9-day drying period followed by a 13-day rewetting period. Concentrations of uranium in mesocosm effluent increased after rewetting, but the cumulative amount of uranium released in the 13 days following the drying constituted less than 1% of the uranium immobilized in the soil during the 5 months prior to the drought. This low level of remobilization suggests that the uranium immobilized in these soils was not primarily bioreduced U(IV), which could have been oxidized to soluble U(VI) during the drought and released in the effluent during the subsequent flood. XANES analyses confirm that most of the uranium immobilized in the mesocosms was U(VI) sorbed to iron oxides. Compared to mesocosms that did not experience drying or rewetting, mesocosms that were sacrificed immediately after drying and after 13 days of rewetting had less uranium in soil near roots and more uranium on root surfaces. Metal-reducing bacteria only dominated the bacterial community after 13 days of rewetting and not immediately after drying, indicating that these bacteria are not responsible for this redistribution of uranium after the drying and rewetting. Results show that short periods of drought conditions in a wetland may

Contamination of roads in Klatovy by natural radionuclides from waste rock dumps of the former uranium mine Ustalec

International Nuclear Information System (INIS)

Nekl, M.; Golias, V.

2002-01-01

Contamination by natural radioisotopes was detected in the road network of the town Klatovy (Czech Republic). The extent and distribution of the contamination were studied using automobile and portable gamma ray spectrometers. Samples of the roadway were taken for a mineralogical and petrological study at two localities. Processes of re-distribution of uranium in the road and its surroundings were studied. (author)

Fast Oxidation Processes in a Naturally Reduced Aquifer Zone Caused by Dissolved Oxygen

Science.gov (United States)

Davis, J. A.; Jemison, N. E.; Williams, K. H.; Hobson, C.; Bush, R. P.

2014-12-01

The occurrence of naturally reduced zones is quite common in alluvial aquifers in the western U.S.A. due to the burial of woody debris in flood plains. The naturally reduced zones are heterogeneously dispersed in such aquifers and are characterized by high concentrations of organic carbon and reduced phases, including iron sulfides and reduced forms of metals, including uranium(IV). The persistence of high concentrations of dissolved uranium(VI) at uranium-contaminated aquifers on the Colorado Plateau has been attributed to slow oxidation of insoluble uranium(IV) mineral phases that are found in association with these natural reducing zones, although there is little understanding of the relative importance of various potential oxidants. Three field experiments were conducted within an alluvial aquifer adjacent to the Colorado River near Rifle, CO wherein groundwater associated with naturally reduced zones was pumped into a gas-impermeable tank, mixed with a conservative tracer (Br-), bubbled with a gas phase composed of 97% O2 and 3% CO2, and then returned to the subsurface in the same well from which it was withdrawn. Within minutes of re-injection of the oxygenated groundwater, dissolved uranium(VI) concentrations increased from less than 1 μM to greater than 2.5 μM, demonstrating that oxygen can be an important oxidant for uranium in these field systems if supplied to the naturally reduced zones. Small concentrations of nitrate were also observed in the previously nitrate-free groundwater, and Fe(II) decreased to the detection limit. These results contrast with other laboratory and field results in which oxygen was introduced to systems containing high concentrations of mackinawite (FeS) rather than the more crystalline iron sulfides found in aged, naturally reduced zones. The flux of oxygen to the naturally reduced zones in the alluvial aquifers occurs mainly through interactions between groundwater and gas phases at the water table, and seasonal variations

Integrating Apparent Conductance in Resistivity Sounding to Constrain 2D Gravity Modeling for Subsurface Structure Associated with Uranium Mineralization across South Purulia Shear Zone, West Bengal, India

Directory of Open Access Journals (Sweden)

Arkoprovo Biswas

2014-01-01

Full Text Available South Purulia Shear Zone (SPSZ is an important area for the prospect of uranium mineralization and no detailed geophysical investigations have been carried out in this region. To delineate the subsurface structure in the present area, vertical electrical soundings using Schlumberger array and gravity survey were carried out along a profile perpendicular to the SPSZ. Apparent conductance in the subsurface revealed a possible connection from SPSZ to Raghunathpur. The gravity model reveals the presence of a northerly dipping low density zone (most likely the shear zone extending up to Raghunathpur under a thin cover of granitic schist of Chotanagpur Granite Gneissic Complex (CGGC. The gravity model also depicts the depth of the zone of density low within this shear zone at ~400 m near Raghunathpur village and this zone truncates with a steep slope. Integration of resistivity and gravity study revealed two possible contact zones within this low density zone in the subsurface at depth of 40 m and 200 m. Our study reveals a good correlation with previous studies in Raghunathpur area characterized by medium to high hydro-uranium anomaly. Thus the conducting zone coinciding with the low gravity anomaly is inferred to be a possible uranium mineralized zone.

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

International Nuclear Information System (INIS)

Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A.J.

2009-01-01

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

Influences of structures on the interlayer oxidation zone sandstone-type uranium deposits on the southern margin of Yili basin

International Nuclear Information System (INIS)

Wang Mou; Li Shengfu

2006-01-01

Based on geology and the theory of hydromorphic origin uranium deposit, structural conditions of uranium formation on the southern margin of Yili Basin are analyzed from two aspects of structural movements and deformation. It is suggested that the subsidiary structures caused by the neotectonic movement are the major factor that control and reform the interlayer oxidation zone sandstone-type uranium deposit, and the differences lie in the tectonics at the eastern and western section on the southern margin of Yili Basin. At the western section, because Mesozoic and Cenozoic strata are tilted by the subsidiary structures, some strata on the margin of the basin outcrop at the surface and suffer from the weathering and erosion, which is favorable for the formation of large size uranium deposits. But at the eastern section, the fault and fold are predominant, outcropping at the surface, cause the redistribution of the uranium, which is favorable for the formation of small size uranium deposits. (authors)

The Alligator rivers natural analogue - Modelling of uranium and thorium migration in the weathered zone at Koongarra

International Nuclear Information System (INIS)

Skagius, K.; Lindgren, M.; Boghammar, A.; Brandberg, F.; Pers, K.; Widen, H.

1993-08-01

The Koongarra Uranium Deposit in the Alligator Rivers Region in the Northern Territory of Australia is a natural analogue being investigated with the aim to contribute to the understanding of the scientific basis for the long term prediction of radionuclide migration within geological environments relevant to radioactive waste repositories. The dispersion of uranium and decay products in the weathered zone has been modelled with a simple advection-dispersion-reversible sorption model and with a model extended to also consider α-recoil and transfer of radionuclides between different mineral phases of the rock. The modelling work was carried out in several iterations, each including a review of available laboratory and field data, selection of the system to be modelled and suitable model, and a comparison of modelling results with field observations. Uranium concentrations in bulk rock calculated with the simple advection-dispersion- reversible sorption model were in fair agreement with observed data using parameter values within ranges recommended based on independent interpretations. The advection-dispersion-reversible sorption model is a large simplification of the system among other things because the partitioning of radionuclides between water and solid phase is described with a sorption equilibrium term only. Although the results from this study not are enough to validate simple performance assessment models in a strict sense, it has been shown that even simple models are able to describe the present day distribution of uranium in the weathered zone at Koongarra. 23 refs, 61 figs

The Alligator rivers natural analogue - Modelling of uranium and thorium migration in the weathered zone at Koongarra

Energy Technology Data Exchange (ETDEWEB)

Skagius, K; Lindgren, M; Boghammar, A; Brandberg, F; Pers, K; Widen, H [Kemakta, Stockholm (Sweden)

1993-08-01

The Koongarra Uranium Deposit in the Alligator Rivers Region in the Northern Territory of Australia is a natural analogue being investigated with the aim to contribute to the understanding of the scientific basis for the long term prediction of radionuclide migration within geological environments relevant to radioactive waste repositories. The dispersion of uranium and decay products in the weathered zone has been modelled with a simple advection-dispersion-reversible sorption model and with a model extended to also consider {alpha}-recoil and transfer of radionuclides between different mineral phases of the rock. The modelling work was carried out in several iterations, each including a review of available laboratory and field data, selection of the system to be modelled and suitable model, and a comparison of modelling results with field observations. Uranium concentrations in bulk rock calculated with the simple advection-dispersion- reversible sorption model were in fair agreement with observed data using parameter values within ranges recommended based on independent interpretations. The advection-dispersion-reversible sorption model is a large simplification of the system among other things because the partitioning of radionuclides between water and solid phase is described with a sorption equilibrium term only. Although the results from this study not are enough to validate simple performance assessment models in a strict sense, it has been shown that even simple models are able to describe the present day distribution of uranium in the weathered zone at Koongarra. 23 refs, 61 figs.

Uranium recovery from mine water

International Nuclear Information System (INIS)

Sarkar, K.M.

1984-01-01

In many plant trials it has been proven that very small amounts (10 to 20 ppm) of uranium dissolved in mine water can be effectively recovered by the use of ion exchange resins and this uranium recovery has many advantages. In this paper an economic analysis at different levels of uranium contamination and at different market prices of uranium are described. For this study an operating mine-mill complex with a sulphuric acid leach circuit, followed by solvent extraction (SX) process, is considered, where contaminated mine water is available in excess of process requirements. It is further assumed that the sulphuric acid eluant containing uranium would be mixed with the mill pregnant liquor stream that proceeds to the SX plant for final uranium recovery

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

International Nuclear Information System (INIS)

Li Yaosong; Zhu Jiechen; Xia Yuliang

1992-02-01

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

Formation conditions for regenerated uranium blacks in uranium-molybdenum deposits

International Nuclear Information System (INIS)

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

1980-01-01

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

Uraninite, Coffinite and Brannerite from Shear-Zone Hosted Uranium Deposits of the Bohemian Massif (Central European Variscan Belt

Directory of Open Access Journals (Sweden)

Miloš René

2017-03-01

Full Text Available New mineralogical data are presented for shear-zone hosted uranium mineralisation from selected uranium deposits that occur in the Bohemian Massif. The uranium mineralisation is in high-grade metamorphic rocks of the Moldanubian Zone and/or in granitic rocks of the Moldanubian batholith and Bor pluton as complex uraninite–coffinite and uraninite–coffinite–brannerite assemblages. For analysed coffinites and brannerites, anomalous enrichment of Y (up to 3.4 wt % Y2O3 and Zr (up to 13.8 wt % ZrO2 is significant. The microprobe data indicate that coffinites from the Rožná and Okrouhlá Radouň uranium deposits contain variable PbO (0–4.3 wt %, FeO (0–2.5 wt %, Al2O3 (0–3.5 wt %, P2O5 (0–1.8 wt %, and CaO (0.7–3.5 wt %. Brannerite is present in unaltered and altered grains with variable concentrations of U4+ (0–0.5 apfu, U6+ (0.06–0.49 apfu, Ti (0.90–2.63 apfu, Ca (0.09–0.41 apfu, and low concentrations of Al (0–0.19 apfu, Th (0–0.04 apfu, Y (0–0.08 apfu, Zr (0–0.13 apfu and REE (0–0.14 apfu.

PROCESS FOR PREPARING URANIUM METAL

Science.gov (United States)

Prescott, C.H. Jr.; Reynolds, F.L.

1959-01-13

A process is presented for producing oxygen-free uranium metal comprising contacting iodine vapor with crude uranium in a reaction zone maintained at 400 to 800 C to produce a vaporous mixture of UI/sub 4/ and iodine. Also disposed within the maction zone is a tungsten filament which is heated to about 1600 C. The UI/sub 4/, upon contacting the hot filament, is decomposed to molten uranium substantially free of oxygen.

Trace Element Mobility in Water and Sediments in a Hyporheic Zone Adjacent to an Abandoned Uranium Mine

Science.gov (United States)

Roldan, C.; Blake, J.; Cerrato, J.; Ali, A.; Cabaniss, S.

2015-12-01

The legacy of abandoned uranium mines lead to community concerns about environmental and health effects. This study focuses on a cross section of the Rio Paguate, adjacent to the Jackpile Mine on the Laguna Reservation, west-central New Mexico. Often, the geochemical interactions that occur in the hyporheic zone adjacent to these abandoned mines play an important role in trace element mobility. In order to understand the mobility of uranium (U), arsenic (As), and vanadium (V) in the Rio Paguate; surface water, hyporheic zone water, and core sediment samples were analyzed using inductively coupled plasma mass spectroscopy (ICP-MS). All water samples were filtered through 0.45μm and 0.22μm filters and analyzed. The results show that there is no major difference in concentrations of U (378-496μg/L), As (0.872-6.78μg/L), and V (2.94-5.01μg/L) between the filter sizes or with depth (8cm and 15cm) in the hyporheic zone. The unfiltered hyporheic zone water samples were analyzed after acid digestion to assess the particulate fraction. These results show a decrease in U concentration (153-202μg/L) and an increase in As (33.2-219μg/L) and V (169-1130μg/L) concentrations compared to the filtered waters. Surface water concentrations of U(171-184μg/L) are lower than the filtered hyporheic zone waters while As(1.32-8.68μg/L) and V(1.75-2.38μg/L) are significantly lower than the hyporheic zone waters and particulates combined. Concentrations of As in the sediment core samples are higher in the first 15cm below the water-sediment interface (14.3-3.82μg/L) and decrease (0.382μg/L) with depth. Uranium concentrations are consistent (0.047-0.050μg/L) at all depths. The over all data suggest that U is mobile in the dissolved phase and both As and V are mobile in the particular phase as they travel through the system.

Modeling subsurface contamination at Fernald

International Nuclear Information System (INIS)

Jones, B.W.; Flinn, J.C.; Ruwe, P.R.

1994-01-01

The Department of Energy's Fernald site is located about 20 miles northwest of Cincinnati. Fernald produced refined uranium metal products from ores between 1953 and 1989. The pure uranium was sent to other DOE sites in South Carolina, Tennessee, Colorado,and Washington in support of the nation's strategic defense programs. Over the years of large-scale uranium production, contamination of the site's soil and groundwater occurred.The contamination is of particular concern because the Fernald site is located over the Great Miami Aquifer, a designated sole-source drinking water aquifer. Contamination of the aquifer with uranium was found beneath the site, and migration of the contamination had occurred well beyond the site's southern boundary. As a result, Fernald was placed on the National Priorities (CERCLA/Superfund) List in 1989. Uranium production at the site ended in 1989,and Fernald's mission has been changed to one of environmental restoration. This paper presents information about computerized modeling of subsurface contamination used for the environmental restoration project at Fernald

Uranium behaviour in the process of tectonite formation in zones of abyssal factures

International Nuclear Information System (INIS)

Dmitriev, V.I.; Berezina, L.A.; Sannikova, L.A.

1977-01-01

The patterns of distribution, concentration and manifestation of uranium and thorium in tectonic formations of different ages, in deep fault zones, have been determined. It has been established that the stage of plastic deformations was not accompanied by a supply of U. The state of brittle deformations, accompanied by an intensive supply of U, is characterized by superimposed U concentrated, primarily, in melanocratic rock-forming minerals, as well as in fissures, in the form of brannerite and pitchblende

An experimental and modeling study of grain-scale uranium desorption from field-contaminated sediments and the potential influence of microporosity on mass-transfer

Science.gov (United States)

Stoliker, D.; Liu, C.; Kent, D. B.; Zachara, J. M.

2012-12-01

The aquifer below the 300-Area of the Hanford site (Richland, WA, USA) is plagued by a persistent plume of dissolved uranium (U(VI)) in excess of the Environmental Protection Agency drinking water maximum contamination level even after the removal of highly contaminated sediments. The aquifer sediments in the seasonally saturated lower vadose zone act as both a source and sink for uranium during stage changes in the nearby Columbia River. Diffusion limitation of uranium mass-transfer within these sediments has been cited as a potential cause of the plume's persistence. Equilibrium U(VI) sorption is a strong function of variable chemical conditions, especially carbonate, hydrogen, and uranyl ion activities. Field-contaminated sediments from the site require up to 1,000 hours to reach equilibrium in static batch reactors. Increases in U(VI) concentrations over longer time-scales result from changes in chemical conditions, which drive reactions with sediments that favor U(VI) desorption. Grain-scale U(VI) sorption/desorption rates are slow, likely owing to diffusion of U(VI) and other solutes through intra-granular pore domains. In order to improve understanding of the impact of intra-granular diffusion and chemical reactions controlling grain-scale U(VI) release, experiments were conducted on individual particle size fractions of a single set of constant chemical conditions with multiple stop-flow events, were similar for all size fractions displacement from equilibrium and multiple diffusion domains were described with a two-parameter lognormal distribution of mass-transfer rate coefficients. Parameters describing mass transfer were the same for all size fractions reaction models calibrated with individual size fractions predicted U(VI) and chemical composition as a function of time for the bulk sediment sample. Volumes of pores less than 2.4 nm, quantified using nitrogen adsorption-desorption isotherms, were the same for all size fractions < 2 mm, nearly double

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

Energy Technology Data Exchange (ETDEWEB)

Goldstein, S.J.; Abdel-Fattah, A.I.; Murrell, M.T.; Dobson, P.F.; Norman, D.E.; Amato, R.S.; Nunn, A. J.

2009-10-01

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

Research of heat releasing element of an active zone of gaseous nuclear reactor with pumped through nuclear fuel - uranium hexafluoride (UF6)

International Nuclear Information System (INIS)

Batyrbekov, G.; Batyrbekov, E.; Belyakova, E.; Kunakov, S.; Koltyshev, S.

1996-01-01

The purpose of the offered project is learning physics and substantiation of possibility of creation gaseous nuclear reactor with pumped through nuclear fuel-hexafluoride of uranium (Uf6).Main problems of this work are'. Determination of physic-chemical, spectral and optical properties of non-equilibrium nuclear - excited plasma of hexafluoride of uranium and its mixtures with other gases. Research of gas dynamics of laminar, non-mixing two-layer current of gases of hexafluoride of uranium and helium at availability and absence of internal energy release in hexafluoride of uranium with the purpose to determinate a possibility of isolation of hexafluoride of uranium from walls by inert helium. Creation and research of gaseous heat releasing element with pumped through fuel Uf6 in an active zone of research nuclear WWR-K reactor. Objects of a research: Non-equilibrium nuclear - excited plasma of hexafluoride of uranium and its mixtures with other gases. With use of specially created ampoules will come true in-reactor probe and spectral diagnostics of plasma. Calculations of kinetics with the account of main elementary processes proceeding in it, will be carried out. Two-layer non-mixed streams of hexafluoride of uranium and helium at availability and absence of internal energy release. Conditions of obtaining and characteristics of such streams will be investigated. Gaseous heat releasing element with pumped through fuel - Uf6 in an active zone of nuclear WWR-K reactor

Regional prognosis criteria for the sandstone type uranium deposits in interlayer oxidation zone and their application in the east of Junggar basin, Xinjiang

International Nuclear Information System (INIS)

Han Deren; Bai Fengzhou; Lin Shuangxing

1995-01-01

Regional prognosis is of a very important role in the exploration work of the sandstone type uranium deposits of interlayer oxidation zone. This paper presents regional prognosis criteria on the basis of the authors' research in combination with the geological prediction in the east of Junggar Basin, Xinjiang (1:200000) which was jointly carried out with the Red Hill Geological Complex of the National Mineral Resources Commission of Uzbekistan Republic. It is advantageous to the exploration work of the sandstone type uranium deposits of interlayer oxidation zone in Meso-Cenozoic basins of China

Uranium and radium content in the soil solutions of the south-western part of Belarus

International Nuclear Information System (INIS)

Sokolik, G.A.; Ovsyannikova, S.V.; Vojnikova, E.V.; Popenya, M.V.

2008-01-01

The contents of uranium and radium in the pore soil solutions, which are the main chain in the geochemical and biological migration of the chemical elements, has been determined for the first time in Belarus. The control sites have been located outside the zone of Chernobyl fallout radionuclide contamination, that allowed evaluating the current background level of uranium and radium content in the soil solutions. The data on accumulation of the radioactive elements in the pore solutions give the opportunity to estimate the reserve of the radioactive elements in the migratory active forms in the soils. In the majority of soils studied, uranium content in the pore solution is higher than radium content, that points to the higher migratory ability of uranium. The direct correlation between content of fulvic acids' components in the soil solutions and accumulation of uranium in such solutions has been established. (authors)

Bicarbonate leaching of uranium

International Nuclear Information System (INIS)

Mason, C.

1998-01-01

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

Bicarbonate leaching of uranium

Energy Technology Data Exchange (ETDEWEB)

Mason, C.

1998-12-31

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

Environmental restoration of uranium contaminated sites in Estonia within the framework of IAEA project (RER/9/022) in 1995-1996

International Nuclear Information System (INIS)

Ratas, R.

1997-01-01

In Estonia there are several radioactively contaminated sites left from the military and uranium progressing activities by the former Soviet Union. Enhanced radiation levels are prevalent in the Paldiski area, a former nuclear submarine training centre; on the territory of the waste depository at Saku/Tammiku and at Sillamae, where a large depository of uranium milling tailings is situated. During the last two years considerable effort has been put into restoration of these sites. To start with, designing of reasonably achievable remediation projects have been taken up. Estonia has received large contributions from many western countries and organisations. Practical remediation work on contaminated areas, e.g. at Sillamae is, however, delayed due to lack of funds. (author)

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

Science.gov (United States)

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

2010-03-01

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

Characteristics and model of sandstone type uranium deposit in south of Songliao basin

International Nuclear Information System (INIS)

Yu Wenbin; Yu Zhenqing

2010-01-01

Through analyzing the uranium deposit tectonic environment, upper cretaceous sequence stratigraphy, depositional system, evolutionary characteristics of sand bodies, the effect of subsequent transformation and the characteristic of uranium deposit, the sandstone type uranium deposit in southern basin is different from typical interlayer oxidation zone sandstone type uranium deposit. The formation and evolution of sandstone-type uranium deposit are controlled by structure fensters; the favorable sedimentary facies type is braided river facies, and the ore body is braided river sand body. The size of uranium deposits is controlled by the local oxidation zone with the characteristics of sandstone type uranium deposit in partial oxidation zone. Uranium ore bodies which distribute in the roof wings of structure fenstes, and occur in gray layers between the upper and lower oxidation zone, showing tabular, and the plate of uranium ore body is controlled by the local oxidation zone. Based on the geological features of sandstone-type uranium deposits, the metallogenic model of local oxidation zones sandstone-type uranium deposits has been set up in the south of Songliao Baisn. (authors)

Remediation of Uranium in the Hanford Vadose Zone Using Ammonia Gas: FY 2010 Laboratory-Scale Experiments

Energy Technology Data Exchange (ETDEWEB)

Szecsody, James E.; Truex, Michael J.; Zhong, Lirong; Qafoku, Nikolla; Williams, Mark D.; McKinley, James P.; Wang, Zheming; Bargar, John; Faurie, Danielle K.; Resch, Charles T.; Phillips, Jerry L.

2010-12-01

This investigation is focused on refining an in situ technology for vadose zone remediation of uranium by the addition of ammonia (NH3) gas. Objectives are to: a) refine the technique of ammonia gas treatment of low water content sediments to minimize uranium mobility by changing uranium surface phases (or coat surface phases), b) identify the geochemical changes in uranium surface phases during ammonia gas treatment, c) identify broader geochemical changes that occur in sediment during ammonia gas treatment, and d) predict and test injection of ammonia gas for intermediate-scale systems to identify process interactions that occur at a larger scale and could impact field scale implementation.Overall, NH3 gas treatment of low-water content sediments appears quite effective at decreasing aqueous, adsorbed uranium concentrations. The NH3 gas treatment is also fairly effective for decreasing the mobility of U-carbonate coprecipitates, but shows mixed success for U present in Na-boltwoodite. There are some changes in U-carbonate surface phases that were identified by surface phase analysis, but no changes observed for Na-boltwoodite. It is likely that dissolution of sediment minerals (predominantly montmorillonite, muscovite, kaolinite) under the alkaline conditions created and subsequent precipitation as the pH returns to natural conditions coat some of the uranium surface phases, although a greater understanding of these processes is needed to predict the long term impact on uranium mobility. Injection of NH3 gas into sediments at low water content (1% to 16% water content) can effectively treat a large area without water addition, so there is little uranium mobilization (i.e., transport over cm or larger scale) during the injection phase.

Remediation of Uranium in the Hanford Vadose Zone Using Ammonia Gas: FY 2010 Laboratory-Scale Experiments

International Nuclear Information System (INIS)

Szecsody, James E.; Truex, Michael J.; Zhong, Lirong; Qafoku, Nikolla; Williams, Mark D.; McKinley, James P.; Wang, Zheming; Bargar, John; Faurie, Danielle K.; Resch, Charles T.; Phillips, Jerry L.

2010-01-01

This investigation is focused on refining an in situ technology for vadose zone remediation of uranium by the addition of ammonia (NH3) gas. Objectives are to: (a) refine the technique of ammonia gas treatment of low water content sediments to minimize uranium mobility by changing uranium surface phases (or coat surface phases), (b) identify the geochemical changes in uranium surface phases during ammonia gas treatment, (c) identify broader geochemical changes that occur in sediment during ammonia gas treatment, and (d) predict and test injection of ammonia gas for intermediate-scale systems to identify process interactions that occur at a larger scale and could impact field scale implementation. Overall, NH3 gas treatment of low-water content sediments appears quite effective at decreasing aqueous, adsorbed uranium concentrations. The NH3 gas treatment is also fairly effective for decreasing the mobility of U-carbonate coprecipitates, but shows mixed success for U present in Na-boltwoodite. There are some changes in U-carbonate surface phases that were identified by surface phase analysis, but no changes observed for Na-boltwoodite. It is likely that dissolution of sediment minerals (predominantly montmorillonite, muscovite, kaolinite) under the alkaline conditions created and subsequent precipitation as the pH returns to natural conditions coat some of the uranium surface phases, although a greater understanding of these processes is needed to predict the long term impact on uranium mobility. Injection of NH3 gas into sediments at low water content (1% to 16% water content) can effectively treat a large area without water addition, so there is little uranium mobilization (i.e., transport over cm or larger scale) during the injection phase.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Slick Rock, Colorado. Revision 1

International Nuclear Information System (INIS)

1995-09-01

Two UMTRA (Uranium Mill Tailings Remedial Action) Project sites are near Slick Rock, Colorado: the North Continent site and the Union Carbide site. Currently, no one uses the contaminated ground water at either site for domestic or agricultural purposes. However, there may be future land development. This risk assessment evaluates possible future health problems associated with exposure to contaminated ground water. Since some health problems could occur, it is recommended that the contaminated ground water not be used as drinking water

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Slick Rock, Colorado. Revision 1

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-09-01

Two UMTRA (Uranium Mill Tailings Remedial Action) Project sites are near Slick Rock, Colorado: the North Continent site and the Union Carbide site. Currently, no one uses the contaminated ground water at either site for domestic or agricultural purposes. However, there may be future land development. This risk assessment evaluates possible future health problems associated with exposure to contaminated ground water. Since some health problems could occur, it is recommended that the contaminated ground water not be used as drinking water.

Vapor Intrusion Estimation Tool for Unsaturated Zone Contaminant Sources. User’s Guide

Science.gov (United States)

2016-08-30

estimation process when applying the tool. The tool described here is focused on vapor-phase diffusion from the current vadose zone source , and is not...from the current defined vadose zone source ). The estimated soil gas contaminant concentration obtained from the pre-modeled scenarios for a building...need a full site-specific numerical model to assess the impacts beyond the current vadose zone source . 35 5.0 References Brennan, R.A., N

Uranium contamination of drinking water in Kazakhstan and Uzbekistan

International Nuclear Information System (INIS)

Kawabata, Y.; Aparin, V.; Shiraishi, K.; Ko, S.; Yamamoto, M.; Nagaia, M.; Katayama, Y.

2006-01-01

Uranium is a naturally occurring radioactive metal, and is widely distributed in the Earth's crust. But it is concentrated in certain rock formations. Most of the uranium for nuclear weapon produced in the Soviet Union during the Cold War came from Central Asia. Uranium has negative effects on the human body, both as a carcinogen and as a kidney toxin. WHO (2004) prescribed that uranium concentrations in drinking water should be less than 15 mcg/l for only chemical aspects of uranium addressed. We determined high uranium concentrations in drinking water in the central region of Uzbekistan (Y. KAWABATA et al. 2004). In this area, some discharge water from farmland has higher uranium concentration. Irrigation systems Kyzyl-orda in Republic of Kazakhstan and in Karakalpakstan in the Republic of Uzbekistan have drains deeper than 5 m, in order to protect against salinization. Water in these drains can mix with ground water. In this area, ground water is used for drinking water. We investigated uranium concentrations in water in Kazakhstan and Uzbekistan. In the half of drinking water sampling points, uranium concentrations exceeded the WHO (2004) guideline level for drinking water. Uranium is a suspected carcinogen that can also have a toxic effect on kidney. However, WHO addresses only the chemical aspects of uranium by giving uranium concentrations in drinking water. The effect of uranium exposure from drinking water on people in these areas is significant. The uranium concentration in the Aral Sea was higher than that in sea water. Aral Sea is accumulating uranium. (author)

Uranium and thorium migration under dislocative metamorphism

International Nuclear Information System (INIS)

Titov, V.K.; Bilibina, T.V.; Dashkova, A.D.; Il'in, V.K.; Makarova, L.I.; Shmuraeva, L.Ya.

1978-01-01

Investigated were peculiarities of uranium and thorium behaviour in the process of dislocation metamorphism on the basis of regional fracture zones of early-proterozoic embedding of Ukrainian, Aldan and Baltic shields. The studied zones correspond to tectonite of green-shale and almandin-amphibolite facies of regional metamorphism according to mineral associations. The most peculiar feature of the tectonites of green-shale facies is uranium presence in migrationally able forms, which can be involved afterwards into the ore process by hydrothermal solutions. Adsorved forms of uranium on the crystal surface or separate grains and in the cracks, as well as microinclusions of uranium minerals, selectively timed to mineral structure defects prevail among easily mobile uranium compounds. Dissolved uranium is present, evidently in gas-liquid inclusions in minerals and pore waters. There forms of uranium presence are peculiar for epidote-chlorite mylonites, as well as cataclasites and diaphthorites related to them by blastomylonites of almandin-amphibolite facies. Wide range of manifestation of this process, caused by multikilometer extension of deep fracture zones permit to consider the formations of green-shale facies of dislocation metamorphism as one of the main uranium sources in deposit formation in different uranium-ore associations different age

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Rifle, Colorado

Energy Technology Data Exchange (ETDEWEB)

NONE

1995-05-01

The ground water project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. This report is a site specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. Currently, no one is using the ground water and therefore, no one is at risk. However, the land will probably be developed in the future and so the possibility of people using the ground water does exist. This report examines the future possibility of health hazards resulting from the ingestion of contaminated drinking water, skin contact, fish ingestion, or contact with surface waters and sediments.

Baseline risk assessment of ground water contamination at the Uranium Mill Tailings Sites near Rifle, Colorado

International Nuclear Information System (INIS)

1995-05-01

The ground water project evaluates the nature and extent of ground water contamination resulting from the uranium ore processing activities. This report is a site specific document that will be used to evaluate current and future impacts to the public and the environment from exposure to contaminated ground water. Currently, no one is using the ground water and therefore, no one is at risk. However, the land will probably be developed in the future and so the possibility of people using the ground water does exist. This report examines the future possibility of health hazards resulting from the ingestion of contaminated drinking water, skin contact, fish ingestion, or contact with surface waters and sediments

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)

The effect of vadose zone heterogeneities on vapor phase migration and aquifer contamination by volatile organics

Energy Technology Data Exchange (ETDEWEB)

Seneviratne, A.; Findikakis, A.N. [Bechtel Corporation, San Francisco, CA (United States)

1995-03-01

Organic vapors migrating through the vadose zone and inter-phase transfer can contribute to the contamination of larger portions of aquifers than estimated by accounting only for dissolved phase transport through the saturated zone. Proper understanding of vapor phase migration pathways is important for the characterization of the extent of both vadose zone and the saturated zone contamination. The multiphase simulation code T2VOC is used to numerically investigate the effect of heterogeneties on the vapor phase migration of chlorobenzene at a hypothetical site where a vapor extraction system is used to remove contaminants. Different stratigraphies consisting of alternate layers of high and low permeability materials with soil properties representative of gravel, sandy silt and clays are evaluated. The effect of the extent and continuity of low permeability zones on vapor migration is evaluated. Numerical simulations are carried out for different soil properties and different boundary conditions. T2VOC simulations with zones of higher permeability were made to assess the role of how such zones in providing enhanced migration pathways for organic vapors. Similarly, the effect of the degree of saturation of the porous medium on vapor migration was for a range of saturation values. Increased saturation reduces the pore volume of the medium available for vapor diffusion. Stratigraphic units with higher aqueous saturation can retard the vapor phase migration significantly.

Yalina booster subcritical assembly performance with low enriched uranium fuel

International Nuclear Information System (INIS)

Talamo, Alberto; Gohar, Yousry

2011-01-01

The YALINA Booster facility is a subcritical assembly located in Minsk, Belarus. The facility has special features that result in fast and thermal neutron spectra in different zones. The fast zone of the assembly uses a lead matrix and uranium fuels with different enrichments: 90% and 36%, 36%, or 21%. The thermal zone of the assembly contains 10% enriched uranium fuel in a polyethylene matrix. This study discusses the performance of the three YALINA Booster configurations with the different fuel enrichments. In order to maintain the same subcriticality level in the three configurations, the number of fuel rods in the thermal zone is increased as the uranium fuel enrichment in the fast zone is decreased. The maximum number of fuel rods that can be loaded in the thermal zone is about 1185. Consequently, the neutron multiplication of the configuration with 21% enriched uranium fuel in the fast zone is enhanced by changing the position of the boron carbide and the natural uranium absorber rods, located between the fast and the thermal zones, to form an annular rather than a square arrangement. (author)

Yalina booster subcritical assembly performance with low enriched uranium fuel

Energy Technology Data Exchange (ETDEWEB)

Talamo, Alberto; Gohar, Yousry, E-mail: alby@anl.gov [Argonne National Laboratory, Lemont, IL (United States)

2011-07-01

The YALINA Booster facility is a subcritical assembly located in Minsk, Belarus. The facility has special features that result in fast and thermal neutron spectra in different zones. The fast zone of the assembly uses a lead matrix and uranium fuels with different enrichments: 90% and 36%, 36%, or 21%. The thermal zone of the assembly contains 10% enriched uranium fuel in a polyethylene matrix. This study discusses the performance of the three YALINA Booster configurations with the different fuel enrichments. In order to maintain the same subcriticality level in the three configurations, the number of fuel rods in the thermal zone is increased as the uranium fuel enrichment in the fast zone is decreased. The maximum number of fuel rods that can be loaded in the thermal zone is about 1185. Consequently, the neutron multiplication of the configuration with 21% enriched uranium fuel in the fast zone is enhanced by changing the position of the boron carbide and the natural uranium absorber rods, located between the fast and the thermal zones, to form an annular rather than a square arrangement. (author)

Heavy metals contamination characteristics in soil of different mining activity zones

Institute of Scientific and Technical Information of China (English)

LIAO Guo-li; LIAO Da-xue; LI Quan-ming

2008-01-01

Depending upon the polluted features of various mining activities in a typical nonferrous metal mine, the contaminated soil area was divided into four zones which were polluted by tailings, mine drainage, dust deposition in wind and spreading minerals during vehicle transportation, respectively. In each zone, soil samples were collected. Total 28 soil samples were dug and analyzed by ICP-AES and other relevant methods. The results indicate that the average contents of Zn, Pb, Cd, Cu and As in soils are 508.6, 384.8, 7.53, 356 and 44.6 mg/kg, respectively. But the contents of heavy metals in different zone have distinct differences. The proportion of oxidizing association with organic substance is small. Difference of the association of heavy metals is small in different polluted zones.

Aluminum titanate crucible for molten uranium

International Nuclear Information System (INIS)

Asbury, J.J.

1975-01-01

An improved crucible for molten uranium is described. The crucible or crucible liner is formed of aluminum titanate which essentially eliminates contamination of uranium and uranium alloys during molten states thereof. (U.S.)

Extrapolation studies on desorption of thorium and uranium at different solution compositions on contaminated soil sediments (Malaysia)

International Nuclear Information System (INIS)

Syed Hakimi Sakuma

2000-01-01

By means of batch desorption experiments, the thorium and uranium desorption properties of contaminated soil sediments are investigated as a function of the effect of cations present in the groundwater. A phenomenological correlation between the desorption coefficient and the concentration of Ca and Mg in the water is determined. Kd Thorium -0.15849 ± 0.03237 log (Ca + Mg) + 5.06715 ± 0.09106; Kd Uranium = -0.11984 ± 0.03237 log (Ca + Mg) + 2.99909 ± 0.09105. By these models the sorption/desorption behaviour of soils can be predicted phenomenologically as function of the groundwater composition. (author)

Uranium fixation by mineralization at the redox front

International Nuclear Information System (INIS)

Isobe, Hiroshi

1998-01-01

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

Advective Removal of Intraparticle Uranium from Contaminated Vadose Zone Sediments, Hanford, USA

International Nuclear Information System (INIS)

Ilton, Eugene S.; Qafoku, Nikolla; Liu, Chongxuan; Moore, D. A.; Zachara, John M.

2008-01-01

A column study on U contaminated vadose zone sediments from the Hanford Site, WA, was performed in order to aid the development of a model for predicting U(VI) release rates under a dynamic flow regime and for variable geochemical conditions. The sediments of interest are adjacent to and below tank BX-102, part of the BX tank farm that contained high level liquid radioactive waste. Two sediments, with different U(VI) loadings and intraparticle large fracture vs. smaller fracture ratios, were reacted with three different solutions. The primary reservoir for U(VI) appears to be a micron-sized nanocrystalline Na-U-Si phase, possibly Na-boltwoodite, that nucleated and grew on plagioclase grains that line fractures within sand-sized granitic clasts. The solutions were all calcite saturated and in equilibrium with atmospheric CO2, where one solution was simply DI-water, the second was a synthetic ground water (SGW) with elevated Na, and the third was the same SGW but with both elevated Na and Si. The latter two solutions were employed, in part, to test the effect of saturation state on U(VI) release. For both sediments and all three electrolytes, there was an initial rapid release of U(VI) to the advecting solution followed by a plateau of low U(VI) concentration. U(VI) effluent concentration increased during subsequent stop flow (SF) events. The electrolytes with elevated Na and Si appreciably depressed U(VI) concentrations relative to DI water. The effluent data for both sediments and all three electrolytes was simulated reasonably well by a three domain model (the advecting fluid, fractures, and matrix) that coupled U(VI) dissolution rates, intraparticle U(VI) diffusion, and interparticle advective transport of U(VI); where key transport and dissolution processes had been parameterized in previous batch studies. For the calcite-saturated DI-water, U(VI) concentrations in the effluent remained far below saturation with respect to Na-boltwoodite and release of U(VI) to

Phytoextraction for clean-up of low-level uranium contaminated soil evaluated

International Nuclear Information System (INIS)

Vandenhove, H.; Hees, M. van

2004-01-01

Spills in the nuclear fuel cycle have led to soil contamination with uranium. In case of small contamination just above release levels, low-cost yet sufficiently efficient remedial measures are recommended. This study was executed to test if low-level U contaminated sandy soil from a nuclear fuel processing site could be phytoextracted in order to attain the required release limits. Two soils were tested: a control soil (317 Bq 238 U kg -1 ) and the same soil washed with bicarbonate (69 Bq 238 U kg -1 ). Ryegrass (Lolium perenne cv. Melvina) and Indian mustard (Brassica juncea cv. Vitasso) were used as test plants. The annual removal of soil activity by the biomass was less than 0.1%. The addition of citric acid (25 mmol kg -1 ) 1 week before the harvest increased U uptake up to 500-fold. With a ryegrass and mustard yield of 15,000 and 10,000 kg ha -1 , respectively, up to 3.5% and 4.6% of the soil activity could be removed annually by the biomass. With a desired activity reduction level of 1.5 and 5 for the bicarbonate-washed and control soil, respectively, it would take 10-50 years to attain the release limit. However, citric acid addition resulted in a decreased dry weight production

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

Characteristics of interlayer oxidation zone and uranium metallogenetic prospect of Zhiluo formation in Daliuta area, Ordos Basin

International Nuclear Information System (INIS)

Yang Jianxin; Li Xide; Zhang Zhaolin

2006-01-01

Ordos Basin is a large down-warping basin in the northwest of North-China Platform; Daliuta area is located in the northeast of Ordos Basin. In this area, sand bodies of fluvial facies developed well in the submember of the lower member of the target Zhiluo Formation of Middle Jurassic and several sand belt of large scale occurred. Yellow interlayer oxidation zone have been discovered in belt I and belt III by the drilling and it is of a certain scale. Due to the young age of interlayer oxidation and unsatisfied uranium sources, uranium metallogenic prospect of this area need more research and exploration. (authors)

Studies on kidney function in workers exposed to uranium contamination

International Nuclear Information System (INIS)

Bugueno, M.C.; Suarez, J.

1983-01-01

The values of some kidney function tests in our workers were studied through the media, range and statistical spread, compared with those used abroad and also in our main hospitals. With that purpose, thirty three personas were selected among those without kidney pathology history of uranium internal contamination as revealed by the permanent control of our clinical and radiotoxicological service. Kidney function was explored through the measurement of uremia, ureic nitrogen, albuminuria, endogenous creatinine clearance and the Addis test. Values determined were normal with respect to those used in the international literature, with the exception of the creatinine clearance test. Also a 6% of our workers were abnormal in at least one or two of the five tests employed. (Author)

Identifying the site of granite uranium deposit with radon survey and soil-natural themoluminescence survey. A case study of Xiazhuang granite uranium field

International Nuclear Information System (INIS)

Yang Yaxin; Wu Yamei; Wu Xinmin; Chen Yue; Zheng Yongming; Zhang Ye; Wu Lieqin

2007-01-01

This paper briefly introduces the methods and procedures for field and indoor radon survey and themoluminescence (TL) survey. The application of these two methods to Xiazhuang uranium field in Guangdong province shows: (1) the positive anomalies of radon survey coincide well with fractured zone and the positive anomalies of TL survey response to uranium mineralization on granite type uranium deposit of silicated fracture zone, the uranium deposit can be effectively explored when these two kinds of anomalies match together. (2) the positive anomalies of radon survey coincide well with fractured zone and the positive anomalies of TL response to the position that intersection between the fractured zone and diabase dyke is projected on the ground. (authors)

TREATABILITY TEST PLAN FOR DEEP VADOSE ZONE REMEDIATION AT THE HANFORD'S SITE CENTRAL PLATEAU

International Nuclear Information System (INIS)

PETERSEN SW; MORSE JG; TRUEX MJ; LAST GV

2007-01-01

A treatability test plan has been prepared to address options for remediating portions of the deep vadose zone beneath a portion of the U.S. Department of Energy's (DOE's) Hanford Site. The vadose zone is the region of the subsurface that extends from the ground surface to the water table. The overriding objective of the treatability test plan is to recommend specific remediation technologies and laboratory and field tests to support the Comprehensive Environmental Response, Compensation, and Liability Act of 1980 and Resource Conservation and Recovery Act of 1976 remedial decision-making process in the Central Plateau of the Hanford Site. Most of the technologies considered involve removing water from the vadose zone or immobilizing the contaminants to reduce the risk of contaminating groundwater. A multi-element approach to initial treatability testing is recommended, with the goal of providing the information needed to evaluate candidate technologies. The proposed tests focus on mitigating two contaminants--uranium and technetium. Specific technologies are recommended for testing at areas that may affect groundwater in the future, but a strategy to test other technologies is also presented

Clay vein and its implication for uranium exploration activity in the northern part of the Alligator Rivers Uranium Field, northern Australia

International Nuclear Information System (INIS)

Sasao, Eiji

2003-01-01

Clay veins have been found by uranium exploration drilling around the Black Rock uranium prospect in the northern part of the alligator Rivers Uranium Field (ARUF), northern Australia. The mineralogical and chemical features are described to clarify relations with uranium mineralization, because it is not accompanied by uranium mineralization. X-ray diffraction and chemical analysis for major elements indicate that the clay vein consists mainly of chlorite (clinochlore to ferroan clinochlore) and lesser mica clay mineral (t-1M dominant). The clay vein is compared with the clay alteration zone around the uranium deposits in ARUF in terms of mode of occurrence, mineral and chemical compositions. Mineral composition of the clay vein is only in accordance with that of the inner alteration halo of the clay alteration zone. It is, however, different from mineral composition of the outer alteration halo in terms of lack of Fe chlorite in the clay vein. Chemical composition of the clay vein is similar to that of the clay alteration zone, except for lack in the vein of high iron content which is observed in some samples of the alteration zone. As a whole, the feature of the clay vein corresponds to the inner alteration zone around the uranium deposit in ARUF. The mode of occurrence of the clay vein is very different from that of the clay alteration zone. Mode of occurrence, and mineral and chemical compositions of the clay vein resemble a chlorite vein in the Lower to Middle Proterozoic sandstone above the Jabiluka deposit, one of major uranium deposit in the ARUF. Because of the similarity between the clay and the chlorite veins, the clay vein is regarded as marginal facies of an alteration zone. The fluid that formed the clay vein is estimated to have been oxidized, because of the existence of hematite and ubiquitous Mg chlorite. This nature is in accordance with the mineralizing fluid that formed the inner alteration zone in the Nabarlek deposit. In conclusion, the vein

Aqueous biphasic extraction of uranium and thorium from contaminated soils. Final report

International Nuclear Information System (INIS)

Chaiko, D.J.; Gartelmann, J.; Henriksen, J.L.; Krause, T.R.; Deepak; Vojta, Y.; Thuillet, E.; Mertz, C.J.

1995-07-01

The aqueous biphasic extraction (ABE) process for soil decontamination involves the selective partitioning of solutes and fine particulates between two immiscible aqueous phases. The biphase system is generated by the appropriate combination of a water-soluble polymer (e.g., polyethlene glycol) with an inorganic salt (e.g., sodium carbonate). Selective partitioning results in 99 to 99.5% of the soil being recovered in the cleaned-soil fraction, while only 0.5 to 1% is recovered in the contaminant concentrate. The ABE process is best suited to the recovery of ultrafine, refractory material from the silt and clay fractions of soils. During continuous countercurrent extraction tests with soil samples from the Fernald Environmental Management Project site (Fernald, OH), particulate thorium was extracted and concentrated between 6- and 16-fold, while the uranium concentration was reduced from about 500 mg/kg to about 77 mg/kg. Carbonate leaching alone was able to reduce the uranium concentration only to 146 mg/kg. Preliminary estimates for treatment costs are approximately $160 per ton of dry soil. A detailed flowsheet of the ABE process is provided

Adaptive response of Chironomus riparius populations exposed to uranium contaminated sediments during consecutive generations

International Nuclear Information System (INIS)

Dias, V.

2010-01-01

The intensity of selection on populations caused by polluted environment often exceeds which is caused by an unpolluted environment. Therefore, micro evolution can occur in response to this anthropic-directional force over a short period. In this context, this thesis focused on studying phenotypic changes in Chironomus riparius populations exposed during several consecutive generations to uranium-contaminated sediments. In laboratory-controlled conditions experiments were conducted with same origin populations exposed to a range of uranium concentration inducing toxic effects. Over eight-generations of exposure, life-history traits measures revealed micro evolution in exposed populations, including increase of adult reproductive success. Other experiments (acute toxicity test, common garden experiment) performed in parallel enabled to link these micro evolution with a tolerance induction, as a consequence of genetic adaptation. Nonetheless this adaptation also induced cost in terms of fitness and genetic diversity for pre-exposed populations. These results lead to the hypothesis of a selection by uranium that acted sequentially on populations. They also underline the need to better-understand the adaptive mechanisms to better assess the ecological consequences of chronic exposure of populations to a pollutant. (author)

Deep Vadose Zone Treatability Test for the Hanford Central Plateau: Interim Post-Desiccation Monitoring Results, Fiscal Year 2014

Energy Technology Data Exchange (ETDEWEB)

Truex, Michael J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Strickland, Christopher E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Christian D. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Johnson, Timothy C. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Clayton, Ray E. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Chronister, Glen B. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

2014-09-01

Over decades of operation, the U.S. Department of Energy (DOE) and its predecessors have released nearly 2 trillion L (450 billion gal.) of liquid into the vadose zone at the Hanford Site. Much of this discharge of liquid waste into the vadose zone occurred in the Central Plateau, a 200 km² (75 mi²) area that includes approximately 800 waste sites. Some of the inorganic and radionuclide contaminants in the deep vadose zone at the Hanford Site are at depths below the limit of direct exposure pathways, but may need to be remediated to protect groundwater. The Tri-Party Agencies (DOE, U.S. Environmental Protection Agency, and Washington State Department of Ecology) established Milestone M 015 50, which directed DOE to submit a treatability test plan for remediation of technetium-99 (Tc-99) and uranium in the deep vadose zone. These contaminants are mobile in the subsurface environment and have been detected at high concentrations deep in the vadose zone, and at some locations have reached groundwater. Testing technologies for remediating Tc-99 and uranium will also provide information relevant for remediating other contaminants in the vadose zone. A field test of desiccation is being conducted as an element of the DOE test plan published in March 2008 to meet Milestone M 015 50. The active desiccation portion of the test has been completed. Monitoring data have been collected at the field test site during the post-desiccation period and are reported herein. This is an interim data summary report that includes about 3 years of post-desiccation monitoring data. The DOE field test plan proscribes a total of 5 years of post-desiccation monitoring.

Subsurface Conditions Controlling Uranium Incorporation in Iron Oxides: A Redox Stable Sink

International Nuclear Information System (INIS)

Fendorf, Scott

2016-01-01

Toxic metals and radionuclides throughout the U.S. Department of Energy Complex pose a serious threat to ecosystems and to human health. Of particular concern is the redox-sensitive radionuclide uranium, which is classified as a priority pollutant in soils and groundwaters at most DOE sites owing to its large inventory, its health risks, and its mobility with respect to primary waste sources. The goal of this research was to contribute to the long-term mission of the Subsurface Biogeochemistry Program by determining reactions of uranium with iron (hydr)oxides that lead to long-term stabilization of this pervasive contaminant. The research objectives of this project were thus to (1) identify the (bio)geochemical conditions, including those of the solid-phase, promoting uranium incorporation in Fe (hydr)oxides, (2) determine the magnitude of uranium incorporation under a variety of relevant subsurface conditions in order to quantify the importance of this pathway when in competition with reduction or adsorption; (3) identify the mechanism(s) of U(VI/V) incorporation in Fe (hydr)oxides; and (4) determine the stability of these phases under different biogeochemical (inclusive of redox) conditions. Our research demonstrates that redox transformations are capable of achieving U incorporation into goethite at ambient temperatures, and that this transformation occurs within days at U and Fe(II) concentrations that are common in subsurface geochemical environments with natural ferrihydrites - inclusive of those with natural impurities. Increasing Fe(II) or U concentration, or initial pH, made U(VI) reduction to U(IV) a more competitive sequestration pathway in this system, presumably by increasing the relative rate of U reduction. Uranium concentrations commonly found in contaminated subsurface environments are often on the order of 1-10 μM, and groundwater Fe(II) concentrations can reach exceed 1 mM in reduced zones of the subsurface. The redox-driven U(V) incorporation

Subsurface Conditions Controlling Uranium Incorporation in Iron Oxides: A Redox Stable Sink

Energy Technology Data Exchange (ETDEWEB)

Fendorf, Scott [Stanford Univ., CA (United States)

2016-04-05

Toxic metals and radionuclides throughout the U.S. Department of Energy Complex pose a serious threat to ecosystems and to human health. Of particular concern is the redox-sensitive radionuclide uranium, which is classified as a priority pollutant in soils and groundwaters at most DOE sites owing to its large inventory, its health risks, and its mobility with respect to primary waste sources. The goal of this research was to contribute to the long-term mission of the Subsurface Biogeochemistry Program by determining reactions of uranium with iron (hydr)oxides that lead to long-term stabilization of this pervasive contaminant. The research objectives of this project were thus to (1) identify the (bio)geochemical conditions, including those of the solid-phase, promoting uranium incorporation in Fe (hydr)oxides, (2) determine the magnitude of uranium incorporation under a variety of relevant subsurface conditions in order to quantify the importance of this pathway when in competition with reduction or adsorption; (3) identify the mechanism(s) of U(VI/V) incorporation in Fe (hydr)oxides; and (4) determine the stability of these phases under different biogeochemical (inclusive of redox) conditions. Our research demonstrates that redox transformations are capable of achieving U incorporation into goethite at ambient temperatures, and that this transformation occurs within days at U and Fe(II) concentrations that are common in subsurface geochemical environments with natural ferrihydrites—inclusive of those with natural impurities. Increasing Fe(II) or U concentration, or initial pH, made U(VI) reduction to U(IV) a more competitive sequestration pathway in this system, presumably by increasing the relative rate of U reduction. Uranium concentrations commonly found in contaminated subsurface environments are often on the order of 1-10 μM, and groundwater Fe(II) concentrations can reach exceed 1 mM in reduced zones of the subsurface. The redox-driven U(V) incorporation