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Sample records for abandoned uranium mill

  1. Long-term ecological behaviour of abandoned uranium mill tailings

    Semi-aquatic and terrestrial areas on abandoned or inactive uranium mill tailings in Ontario were studied in order to identify the growth characteristics of the naturally invading species dominating these areas. Semi-aquatic areas of tailings sites have been invaded by cattails. These species formed wetland communities which varied in size, but all were essentially monocultures of Typha latifolia, T. angustifolia, or of the hybrids T. glauca. Sedges, Scripus cyperinus (wool-grass) and Phragmites australis (reed-grass), were found in transition zones between the cattail stand and the dry section of the tailings site. The expansion of the cattail stands appeared to be controlled by the hydrological conditions on the site, rather than the chemical characteristics of the tailings

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

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

  3. Long-term ecological behaviour of abandoned uranium mill tailings. 1

    Inactive uranium mill tailings were surveyed in the Province of Ontario to describe their surface characteristics, identify naturally invading biota, and determine essential chemical and physical parameters associated with the tailings. Inactive tailings sites can have wet areas, tailings completely covered with water, and dry areas. In the wet areas of most sites, wetland vegetation stands were found which were dominated by species of cattails (Typhaceae), along with some species of rushes (Juncaceae) and sedges (Cyperceae). Dry areas of the tailings exhibited a variety of surface features which are often a reflection of different amelioration efforts. Most of the indigenous species of vascular plants identified on dry areas of the tailings occurred only sporadically. Invading plants found on most sites were the tree species, trembling aspen (Populus tremuloides) and paper birch (Betula papyrifera). Elemental concentration and some physical characteristics of the tailings collected from a depth of 0-20 cm were determined. Uptake of heavy metals and radionuclides were evaluated in trees found in the dry areas and in cattails (Typha latifolia) in the wetland areas. Water bodies on tailings and surface water leaving the tailings, before and after treatment, were characterized in this survey. Aquatic bryophytes have invaded some water bodies on the tailings, and acid tolerant algae were evident in most of the water associated with the tailings. Ecological processes occurring on inactive uranium mill tailings which were identified in this survey are essential in evaluating the long-term fate of these waste sites

  4. Biological assessment of remedial action at the abandoned uranium mill tailings site near Naturita, Colorado

    NONE

    1996-03-01

    Pursuant to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, the U.S. Department of Energy (DOE) is proposing to conduct remedial action to clean up the residual radioactive materials (RRM) at the Naturita uranium processing site in Colorado. The Naturita site is in Montrose County, Colorado, and is approximately 2 miles (mi) (3 kilometer [km]) from the unincorporated town of Naturita. The proposed remedial action is to remove the RRM from the Naturita site to the Upper Burbank Quarry at the Uravan disposal site. To address the potential impacts of the remedial action on threatened and endangered species, the DOE prepared this biological assessment. Informal consultations with the U.S. Department of the Interior, Fish and Wildlife Service (FWS) were initiated in 1986, and the FWS provided a list of the threatened and endangered species that may occur in the Naturita study area. This list was updated by two FWS letters in 1988 and by verbal communication in 1990. A biological assessment was included in the environmental assessment (EA) of the proposed remedial action that was prepared in 1990. This EA addressed the impacts of moving the Naturita RRM to the Dry Flats disposal site. In 1993, the design for the Dry Flats disposal alternative was changed. The FWS was again consulted in 1993 and provided a new list of threatened and endangered species that may occur in the Naturita study area. The Naturita EA and the biological assessment were revised in response to these changes. In 1994, remedial action was delayed because an alternate disposal site was being considered. The DOE decided to move the FIRM at the Naturita site to the Upper Burbank Quarry at the Uravan site. Due to this delay, the FWS was consulted in 1995 and a list of threatened and endangered species was provided. This biological assessment is a revision of the assessment attached to the Naturita EA and addresses moving the Naturita RRM to the Upper Burbank Quarry disposal site.

  5. An investigation into selected ecological aspects of the aquatic and terrestrial environment of an abandoned uranium mill tailings pond, Bancroft, Ontario

    This report consists of four independent studies of disused uranium mill tailings areas. The studies cover surface water movements, limnology, invasion of the tailings by vegetation, and soil nematodes in the mill tailings. (O.T.)

  6. Uranium mining and milling

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

  7. Uranium-mill appraisal program

    The results of special team appraisals at NRC-licensed uranium mills in the period May to November 1981 are reported. Since the Three Mile Island accident, NRC management has instituted a program of special team appraisals of radiation protection programs at certain NRC-licensed facilities. These appraisals were designed to identify weaknesses and strengths in NRC-licensed programs, including those areas not covered by explicit regulatory requirements. The regulatory requirements related to occupational radiation protection and environmental monitoring at uranium mills have been extensively upgraded in the past few years. In addition, there was some NRC staff concern with respect to the effectiveness of NRC licensing and inspection programs. In response to this concern and to changes in mill requirements, the NRC staff recommended that team appraisals be conducted at mills to determine the adequacy of mill programs, the effectiveness of the new requirements, and mill management implementation of programs and requirements. This report describes the appraisal scope and methodology as well as summary findings and conclusions. Significant weaknesses identified during the mill appraisals are discussed as well as recommendations for improvements in uranium mill programs and mill licensing and inspection

  8. Uranium mill tailings and radon

    The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the US may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action Program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100

  9. Uranium mill tailings and radon

    The major health hazard from uranium mill tailings is presumed to be respiratory cancer resulting from the inhalation of radon daughter products. A review of studies on inhalation of radon and its daughters indicates that the hazard from the tailings is extremely small. If the assumptions used in the studies are correct, one or two people per year in the United States may develop cancer as a result of radon exhaled from all the Uranium Mill Tailings Remedial Action program sites. The remedial action should reduce the hazard from the tailings by a factor of about 100

  10. 77 FR 14837 - Bioassay at Uranium Mills

    2012-03-13

    ... COMMISSION Bioassay at Uranium Mills AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide... for public comment draft regulatory guide (DG), DG-8051, ``Bioassay at Uranium Mills.'' This guide describes a bioassay program acceptable to the NRC staff for uranium mills and applicable portions...

  11. Colorado's prospectus on uranium milling

    The first part of this paper will discuss Colorado's control of uranium mill tailings under Titles I and II of the Uranium Mill Tailings Radiation Control Act of 1978. Colorado has a legacy of nine inactive mill sites requiring reclamation under Title I, and two presently active plus a number of new mill proposals which must be regulated in accordance with Title II. Past failures in siting and control on the part of federal jurisdictions have left the state with a heavy legacy requiring extensive effort to address impacts to the state's environment and population. The second part of this paper will discuss the remedial action programme authorized under Public Law 92-314 for Mesa Country, where lack of federal control led to the dispersal of several hundred thousand tons of uranium mill tailings on thousands of properties, including hundreds of homes, schools and other structures. Successful completion of the State efforts under both programmes will depend on a high level of funding and on the maintenance of adequate regulatory standards. (author)

  12. Grouting of uranium mill tailings piles

    A program of remedial action was initiated for a number of inactive uranium mill tailings piles. These piles result from mining and processing of uranium ores to meet the nation's defense and nuclear power needs and represent a potential hazard to health and the environment. Possible remedial actions include the application of covers to reduce radon emissions and airborne transport of the tailings, liners to prevent groundwater contamination by leachates from the piles, physical or chemical stabilization of the tailings, or moving the piles to remote locations. Conventional installation of liners would require excavation of the piles to emplace the liner; however, utilization of grouting techniques, such as those used in civil engineering to stabilize soils, might be a potential method of producing a liner without excavation. Laboratory studies on groutability of uranium mill tailings were conducted using samples from three abandoned piles and employing a number of particulate and chemical grouts. These studies indicate that it is possible to alter the permeability of the tailings from ambient values of 10-3 cm/s to values approaching 10-7 cm/s using silicate grouts and to 10-8 cm/s using acrylamide and acrylate grouts. An evaluation of grouting techniques, equipment required, and costs associated with grouting were also conducted and are presented. 10 references, 1 table

  13. Restoration activities in uranium mining and milling facilities in Spain

    From the end of the 80's up to now, several tasks have been carried out in Spain on restoration in the field of uranium mining and milling, significant among them being Andujar Uranium Mill (FUA) closure and La Haba closure. Also, a study has been carried out on restoration of inoperative and abandoned uranium mine sites. At present, detailed plans are being worked out for the project on the closure of the Elefante plant. All activities have been developed in the common framework of national standards and regulations which are generally in compliance with the standards, regulations and recommendations of international organizations. This paper describes briefly the standards and the criteria applied to the restoration tasks at various sites of the uranium mining and milling facilities in Spain. The restoration activities have different characteristics La Haba facility is an isolated and conventional facility to produce uranium concentrate; in the case of old and abandoned uranium mines the intervention criteria is more relevant than the activities to be carried out; the closure (the first phase of licensing) and restoration activities of Elefante plant have to be developed taking into account that it is sited within the area of Quercus plant which is currently in operation. (author)

  14. Environmental planning in uranium milling

    Effluents from uranium milling in the Achala region in the province of Cordoba are studied. Liquids from lixiviation-recovery and from precipitation-washing of yellow-cake were analyzed. Separation of both liquids before treatment and disposal is recommended. Data of the hydric environment are presented specially for volumes of flow. The disposal criteria established by the provincial authorities are presented, and discussed. Calculations to define the effects on the environment of two types of effluents (the leaching effluent without treatment and the same after treating it) on two points of the rivers net, are given and the results discussed. A disposal policy for a treated effluent of mean composition is presented, based on two different amounts for the two phases of the river flux; the possible effects on two points of the net were also calculated. In the author's opinion, such policy will result in a disposal without a sensible damage in the receptor. (Author)

  15. Environmental burden from past uranium mining and milling activities

    Based on a government decree, the Czechoslovak Uranium Industry (CSUP) was required to adopt a uranium mining phasing-out programme in the late 1980s. Throughout the 1990s, uranium mining was abandoned step by step in the Czech Republic except for the Rozna deposit which is still in use. For 17 major mining sites, the environmental impacts caused by the mining activity and by the existing burden from past uranium exploration, mining and milling were assessed. Remedial actions are under way, including reclamation of the sites affected. The programme is funded from the state budget, and the implementation of the programme is the responsibility of the successor to the CSUP, i.e. DIAMO, a state-owned company seated at Straz pod Ralskem. (author)

  16. Environmental design of a uranium mill

    In the frame work of the Cleaner Technology Project for Uranium Mining and Milling, Australian Nuclear and Technology Organization (ANSTO), Environment Division of ANSTO has carried out a programme of research which seeks to identify, investigate and develop cleaner technologies that have the potential to minimize the environmental impact of uranium mining and milling. This paper describes three design options of a new uranium mill that can meet environmental, technical and economical objectives. The feasibility of such an approach was examined in the laboratory and in a pilot plant study. (author)

  17. W.B. Lewis Lecture: Cleaning-up abandoned uranium mines in Saskatchewan's North

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

  18. Radiochronological Age of a Uranium Metal Sample from an Abandoned Facility

    Meyers, L A; Williams, R W; Glover, S E; LaMont, S P; Stalcup, A M; Spitz, H B

    2012-03-16

    A piece of scrap uranium metal bar buried in the dirt floor of an old, abandoned metal rolling mill was analyzed using multi-collector inductively coupled plasma mass spectroscopy (MC-ICP-MS). The mill rolled uranium rods in the 1940s and 1950s. Samples of the contaminated dirt in which the bar was buried were also analyzed. The isotopic composition of uranium in the bar and dirt samples were both the same as natural uranium, though a few samples of dirt also contained recycled uranium; likely a result of contamination with other material rolled at the mill. The time elapsed since the uranium metal bar was last purified can be determined by the in-growth of the isotope {sup 230}Th from the decay of {sup 234}U, assuming that only uranium isotopes were present in the bar after purification. The age of the metal bar was determined to be 61 years at the time of this analysis and corresponds to a purification date of July 1950 {+-} 1.5 years.

  19. Health risks from uranium mill tailings

    This paper reviews the risk to public health and the environment from uranium mill tailings. The steps taken by the Environmental Protection Agency (EPA) to reduce this risk from tailing are summarized

  20. Radiological health aspects of uranium milling

    This report describes the operation of conventional and unconventional uranium milling processes, the potential for occupational exposure to ionizing radiation at the mill, methods for radiological safety, methods of evaluating occupational radiation exposures, and current government regulations for protecting workers and ensuring that standards for radiation protection are adhered to. In addition, a survey of current radiological health practices is summarized

  1. Reclamation of uranium mining and milling disturbances

    Since 1945 the history of uranium mining and milling in the US has been a story of wide fluctuations in market prices and in mining and milling capacity. The late 1960's and the 1970's saw a sizeable reduction in the production of yellowcake because of an earlier over-supply, a leveling off of the military demand, and a failure of the nuclear electric power industry to create the anticipated commercial demand. The decline in the domestic production of yellowcake has continued through the early 1980's to the present. Today, there are five operating uranium mills in the US: one in Wyoming, two in Utah, one in New Mexico, and one in Texas. Of these five mills, three are operating on a reduced schedule, as little as three days a month. A significant portion of the current US production of uranium goes overseas to fulfill Japanese, French, and other European contracts. There is still a sizeable reclamation job to be accomplished on old uranium wastes, both tailings impoundments and overburden embankments. Before the Uranium Mill Tailings Control Act of 1978 (PL 95-604), reclamation was frequently omitted altogether, or else done in a haphazard fashion. We do not know the total area of unreclaimed, radioactive, uranium overburden wastes in the western US, but the area is large, probably several thousand hectares. Fortunately, these overburden wastes are almost entirely located in remote areas. Mill tailings are more difficult to reclaim than overburden, and tailings represent a more serious health hazards. There are approximately 25 million metric tons of unreclaimed uranium mill tailings, with variable health hazards, located in the US

  2. Abandoning uranium mining in Germany. Rehabilitation of the Wismut site

    After the unification of Germany in 1989, the Government decided to abandon uranium mining in two lands of the former Eastern Germany, in Saxonia and Thuringia. The closing of the mines and the reclamation and rehabilitation of the site cost more than 10 billion USD. The rehabilitation of the Wismut site is described in detail. (R.P.)

  3. Regulatory oversight of uranium mines and mills

    Full text: The Canadian Nuclear Safety Commission (CNSC) is the principal nuclear regulator in Canada. The CNSC is empowered through the Nuclear Safety and Control Act (NSCA) and associated regulations, to regulate the entire nuclear cycle which includes uranium mining and milling. The paper discusses the regulatory oversight of uranium mines and mills which include: - Who is CNSC, what is the CNSC's mission and CNSC background - Oversight Management System; - Regulatory Framework; - Expectations for Assessing Compliance; - QA Principles and Program Elements; - A Look to the Future; - Planning regulatory oversight activities; - Management System Documentation Review; - Regulatory Oversight Activities; - Following-up On Inspections; - Enforcing Compliance with Requirements; - Improving the Regulatory Oversight Process. (author)

  4. Domestic uranium mining and milling industry 1991

    This report was prepared by the Energy Information Administration to provide the Secretary of Energy with basic data and analyses for ninth annual determination of the viability of the domestic uranium mining and milling industry. A viability determination is required annually, for the years 1983 through 1992, by Section 170B of the Nuclear Regulatory Commission (NRC) Authorization Act of 1983, Public Law 97-415, which amend the Atomic Energy Act of 1954. Topics include: evolution of the U.S. uranium industry; nuclear power requirements and uranium industry projections; and attributes of industry viability

  5. Environmental impact of uranium mining and milling

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

  6. Decommissioning plan for Andujar uranium mill facilities

    The milling of radioactive ores results in contaminated buildings and facilities which must be decommissioned, and large quantities of tailings which must be managed safely so that residual environmental and health risks do not exceed acceptable levels. In the south of Spain on the outskirts of the town of Andujar an inactive uranium mill facility is under decommissioning. Mill equipment, buildings and process facilities have been dismantled and demolished and the resulting metal wastes and debris have been placed in the pile. The tailing mass is being reshaped by flattening the sideslopes and a cover system will be placed over the pile. This paper describes the safety aspects and technical approaches which are being used for the remediation and closure of the Andujar mill site. (author). 7 figs

  7. Uranium Mill Tailings Remedial Action Project surface project management plan

    This Project Management Plan describes the planning, systems, and organization that shall be used to manage the Uranium Mill Tailings Remedial Action Project (UMTRA). US DOE is authorized to stabilize and control surface tailings and ground water contamination at 24 inactive uranium processing sites and associated vicinity properties containing uranium mill tailings and related residual radioactive materials

  8. Sohio's L-Bar uranium mill

    Sohio Petroleum Company's new L-Bar uranium mill near Grants, New Mexico, refines 2722 kilograms of yellowcake daily from 1360 metric tons of ore produced at Sohio's J.J. No. 1 mine and other nearby mines. This paper follows the ore from the mine through the various processing steps - semi-autogenous grinding, acid leaching, countercurrent decantation, solvent extraction, ammonium diuranate precipitation, washing and drying, and tailings disposal. (author)

  9. Environmental impact of uranium mining and milling

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

  10. Development of uranium milling and conversion

    The development and improvement of uranium milling and refining producing uranium tetrafluoride from ores by the wet process, without producing yellowcake as an intermediate product, have been carried out for over ten years with a small pilot plant (50 t-ore/day). In the past several years, a process for converting uranium tetrafluoride into hexafluoride has been developed successfully. To develop the process further, the construction of an integrated milling and conversion pilot plant (200 t-U/year) started in 1979 and was completed in 1981. This new plant has two systems of solvent extraction using tri-noctylamine: one of the systems treats the pregnant solution (uranyl sulphate) by heap-leaching followed by ion exchange, and the other treats the uranyl sulphate solution by dissolving imported yellowcake. The uranium loading solvents from the two systems are stripped with hydrochloric acid solution to obtain the concentrated uranium solution containing 100 g-U/1. Uranyl sulphate solution from the stripping circuit is reduced to a uranous sulphate solution by the electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectively as catholyte and anolyte, and a cation exchange membrane is used to prevent re-oxidation of the uranous sulphate. In the following hydrofluorination step, uranium tetrafluoride, UF4.1-1.2H2O (particle size: 50-100μ), is produced continuously as the precipitate in an improved reaction vessel, and this makes it possible to simplify the procedures of liquid-solid separation, drying and granulation. The uranium tetrafluoride is dehydrated by heating to 3500C in an inert gas flow. The complete conversion from UF4 into UF6 is achieved by a fluidized-bed reactor and a high value of utilization efficiency of fluorine, over 99.9 percent, is attained at about 4000C. (author)

  11. The problem of abandoned uranium tailings in northern Saskatchewan

    Two Saskatchewan tailings sites, Lorado and Gunnar, covering approximately 89 ha., were abandoned in the early 1960s leaving untreated tailings in lakes and depressions. This report reviews the literature on environmental conditions in abandoned uranium tailings and available managmenet and mitigation options, and identifies research requirements essential for proper treatment of these two sites. The recommended management plan includes isolation of the exposed tailings area from surface waters, stabilization of the exposed tailings surfaces, diversion of runoff around tailings, treatment of overflow water before release, and implementation of an environmental monitoring program. Revegetation appears to be a promising stabilization measure, but research is needed into propagation methods of appropriate native species. Studies of the existing geological and hydrological conditions at both sites, detailed characterization of the wastes, field testing of different surface treatment methods, and nutrient cycling investigations are also needed

  12. Engineering assessment of inactive uranium mill tailings

    1981-07-01

    The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost estimated to be about $41,900,000. Three principal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive.

  13. Engineering assessment of inactive uranium mill tailings

    The Grand Junction site has been reevaluated in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Grand Junction, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.9 million tons of tailings at the Grand Junction site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The eight alternative actions presented herein range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $10,200,000 for stabilization in-place to about $39,500,000 for disposal in the DeBeque area, at a distance of about 35 mi, using transportation by rail. If transportation to DeBeque were by truck, the cost estimated to be about $41,900,000. Three principal alternatives for the reprocessing of the Grand Junction tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $200/lb by heap leach and $150/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery appears not to be economically attractive

  14. A guide to the licensing of uranium and thorium mine and mill waste management systems

    This document is issued to assist industry and the public in understanding the licensing process used by the Canadian Atomic Energy Control Board (AECB), and do describe and consolidate the requirements, criteria and guidelines the AECB uses in the regulation of uranium and thorium mine and mill waste management systems. All phases of these systems are addressed, including pre-development activities, siting and construction, operation, and decommissioning and abandonment

  15. Uranium Mill Tailings Remediation in Central Asia

    Uranium ore is a naturally occurring radioactive material which is often regarded as something separate to NORM due to its place at the front end of the nuclear fuel cycle. Uranium mining and processing was a significant industry in the Central Asian countries of the former Soviet Union. When the Soviet Union broke up in 1989 these countries gained their independence but the uranium mining industry now had to try and survive in a new economic environment. In Tajikistan and Kyrgyzstan this proved too great a challenge. Production stopped and sites were simply abandoned with little or no attention paid to remediation. Skilled personnel departed and both physical and regulatory infrastructure decayed. Consequently, the legacies of the former times remained throughout Central Asia to become an issue of considerable concern to many. The sites were generally uncontrolled and the NORM residues from the mining and processing were a source of environmental contamination which also threatened public health in a number of ways. In recent years there has been considerable activity by a number of international agencies and Governments working towards solutions for these issues. Much of the effort has been undertaken by the IAEA and this paper describes the original situation, the development of remediation strategies and the various remediation related projects, their outcomes to date, and plans for the future in both the political and scientific arenas. (author)

  16. Recycling and reuse of wastewater from uranium mining and milling

    Uranium mining/milling process, and the sources, recycling/reuse approach and treatment methods of process wastewater are introduced. The wastewater sources of uranium mining and milling include effluent, raffinate, tailings water, mine discharge, resin form converted solution, and precipitation mother liquor. Wastewater can be recycled/reused for leachant, eluent, stripping solution,washing solution and tailings slurry. (authors)

  17. Training manual for uranium mill workers on health protection from uranium

    This report provides information for uranium mill workers to help them understand the radiation safety aspects of working with uranium as it is processed from ore to yellowcake at the mills. The report is designed to supplement the radiation safety training provided by uranium mills to their workers. It is written in an easily readable style so that new employees with no previous experience working with uranium or radiation can obtain a basic understanding of the nature of radiation and the particular safety requirements of working with uranium. The report should be helpful to mill operators by providing training material to support their radiation safety training programs

  18. Radioactive pollution investigation and disposal of abandoned uranium mines in Jiangsu province

    The environment influence of five abandoned uranium mines in Jiangsu province from 1950s to 1960s is introduced. By monitoring air absorbed dose rate of external exposure γ radiation, it is found that the pollution scope of No.1 abandoned uranium mine is the biggest in five abandoned uranium mines. The No. 2 and No. 3 mine areas has achieved the limit use after they were desposed. The radioactivity and the gamma nuclein in solid samples(slag, soil, silt) and liquid samples (the surface water, the well water)of No. 1 abandoned uranium mine were further analyzed and measured, the measured values are higher. The pollution of abandoned uranium mines still exists and diffuses after 30 years. According to the monitoring results and the analysis of pollution present situation, suggestions and measures are proposed for the pollution control. (authors)

  19. Groundwater contamination at the inactive Riverton, Wyoming uranium mill tailings

    Low pH process waters contained in a number of inactive and abandoned uranium mill tailings in the United States represent potential sources of radionuclide and trace metal contamination of ground water. Detailed investigation at a typical site at Riverton, Wyo., U.S.A. indicates chemical transport occurs from initial dewatering of the tailings, downward infiltration due to precipitation, and groundwater intrusion into the base of the tailings pile. Relict contaminant plumes, including sulfate, in the shallow groundwater, indicate past periods of tailing dewatering. Except for elevated uranium and molybdenum concentrations, radionuclide and trace metal transport are limited by near-neutral pH conditions in the groundwater. pH is controlled by neutralization of acid tailings water by soil carbonates. A geochemical mixing model employing the PHREEQE computer code is used to estimate current rates of the ground water contamination by tailings water. Significant reactions are the dissolution of calcite, formation of CO2 and precipitation of gypsum and iron and aluminum hydroxides. Calculated results indicate a mixing rate of 1.5 x 10-4 m3.s-1 beneath the tailings and an evapotranspiration loss of 1.8 x 10-3 m3.s-1 from the tailings surface

  20. Remediation of uranium mill tailings wastes in Australia: a critical review

    Australia has been an active participant in the global uranium mining industry since its inception in the 1940s. By the late 1950s five major mining and milling projects were operating, several small mines supplied custom ores. All of these projects were closed by the early 1960s, except for Rum Jungle which continued under government subsidy. Most sites have had lasting Environmental impacts. The advances in nuclear power in the 1960s saw increasing demand for uranium and Australia again explored with remarkable success in the Northern Territory, South Australia and Western Australia. After several government inquiries in the 1970s, Ranger, Nabarlek and Olympic Dam were operating by the mid 1980s. The principal risks from uranium mill tailings wastes arise from their radioactive nature and often their chemical toxicities. A critical review of the rehabilitation of abandoned uranium mines and mill tailings as a comparison for current projects is presented. It is concluded that the management of uranium mill tailings wastes is a complex task, requiring a sound multi-disciplinary approach. The problems include groundwater contamination, erosion, radon emanation and gamma radiation. evidence to data from the remediation of old and modern sites does not demonstrate effective long-term closure and safety

  1. Biogenic treatment of uranium mill effluents

    It is necessary to treat mine/mill effluents before discharging to the environment as per the regulatory requirements. Effluents from a uranium mill normally contain 226Ra as a pollutant, which needs treatment. Normally wastewater treatment consists of lime addition to increase the pH to 10 which precipitates most contaminants except 226Ra. The current chemical treatment of 226Ra is by co-precipitation as barium-radium-sulphate by addition of barium chloride. There is a considerable concern about the long-term stability of barium-radium sludge due to re-dissolution of radium when contacted with fresh water. Adsorption can be another metal specific physio-chemical process. The most recent development in environment biotechnology is the use of microbe based bio-sorbents for the recovery of toxic metals from industrial effluent. A fungal species of Pencillium chrysogenum has been found to be a 226Ra specific biosorbent. It has been observed that up to 96% of 226Ra values can be adsorbed by chemically treated biomass of Pencillium chrysogenum from effluent containing 226Ra in the range of 400-2000 Bq m-3. Biomass in the form of granules can be used in columns, like resins, to remove 226Ra values. It is proposed that this process can replace or substitute the present barium chloride treatment of mill effluents. (author)

  2. Decommissioning and disposal of foreign uranium mine and mill facilities

    Disposal techniques in decommissioning of foreign uranium mine and mill facilities are systematically discussed, including covering of uranium tailing impoundment, drainaging and consolidation of uranium tailing, and treatment of mining waste water and polluted groundwater, and the costs associated with disposal are analyzed. The necessity of strengthening the decommissioning disposal technology research and international exchanges and cooperation is emphasized. (authors)

  3. Study of the Utah uranium-milling industry. Volume II. Utah energy resources: uranium

    This report is a general overview of the uranium mining and milling industry and its history and present status with particular reference to Utah. This volume serves two purposes: (1) it serves as a companion volume to Volume I, which is a policy analysis; and (2) it serves as one of a set of energy resource assessment studies previously performed by the authors. The following topics are covered: development of the uranium industry on the Colorado Plateau with emphasis on Utah; geology of uranium; uranium reserves; uranium exploration in Utah; uranium ore production and mining operation in Utah; uranium milling operations in Utah; utilization of uranium; uranium mill tailings; and future outlook. Appendices on pricing of uranium and incentives for production since World War II are also presented

  4. Overview of uranium mill tailings remedial action project of the United States of America 1995-1996

    From the early 1940's through the 1960's the United States federal government contracted for processed uranium ore for national defense research, weapons development and commercial nuclear energy. When these contracts were terminated, the mills ceased operation leaving large uranium tailings on the former mill sites. The purpose of the Uranium Remedial Action Project (UMTRA) is to minimize or eliminate potential health hazards resulting from exposure of the public to the tailings at these abandons sites. There are 24 inactive uranium mill tailings sites, in 10 states and an Indian reservation lands, included for clean up under the auspices of UMTRA. Presently the last 2 sites are under remediation. This paper addresses the progress of the project over the last two years. (author)

  5. Tree growth studies on uranium mill tailings

    Coniferous trees planted in 1974 and deciduous species that have volunteered since 1970 on uranium mill tailings that had been stabilized to varying degrees using limestone and vegetation were evaluated. Their survival and growth rates were compared with those from other investigations. Competition for light appears to be a major contributor to mortality. Differences in soil moisture conditions under a tree stand as compared to those under a grass sward are potentially significant enough to affect the tailings hydrology and effluent contamination. Recommendations include planting seeds of deciduous species or deciduous and coniferous seedlings on strips of freshly disturbed tailings. The disturbed strips would provide reduced competition for the initial year and assist in tree survival. The planting of block stands of coniferous or deciduous trees would be useful for evaluating the hydrological impact of the trees as compared to the present grass sward

  6. Domestic uranium mining and milling industry 1989

    Section 170B of the Atomic Energy Act of 1954, as amended by Public Law 97-415, requires that the Secretary of Energy submit to Congress an annual assessment of the viability of the domestic uranium mining and milling industry. The Energy Information Administration (EIA) of the Department of Energy (DOE) was assigned the responsibility to develop the criteria for use in estimating the viability of the industry. These criteria include four major attributes of industry viability - resource capability, supply response capability, financial capability, and import commitment dependency. Having established these criteria, the Secretary of Energy is required to monitor the industry and make an annual assessment of its viability for 1983 through 1992. The first six assessments were issued in the years 1984 through 1989 based on information available for 1983 through 1988, respectively. The current report provides the data and analyses, based on the information available through the end of the calendar year 1989, supporting the seventh annual assessment of the uranium industry's viability. It presents information on the four major attributes. Data on past and present industry behavior, as well as projections of the future status of the industry (assuming current market conditions), were used to examine the industry's ability to respond, over a 10-year period, to two hypothetical supply disruption scenarios. 20 figs., 23 tabs

  7. Programmatic Environmental Impact Statement for the Uranium Mill Tailings Remedial Action Ground Water Project

    Public concern regarding the potential human health and environmental effects from uranium mill tailings led Congress to pass the Uranium Mill Tailings Radiation Control Act (UMTRCA) (Public Law 95-604) in 1978. In the UMTRCA, Congress acknowledged the potentially harmful health effects associated with uranium mill tailings at 24 abandoned uranium mill processing sites needing remedial action. Uranium processing activities at most of the 24 mill processing sites resulted in the formation of contaminated ground water beneath and, in some cases, downgradient of the sites. This contaminated ground water often has elevated levels of hazardous constituents such as uranium and nitrate. The purpose of the Ground Water Project is to protect human health and the environment by meeting EPA-proposed standards in areas where ground water has been contaminated with constituents from UMTRA Project sites. A major first step in the UMTRA Ground Water Project is the preparation of this Programmatic Environmental Impact Statement (PEIS). This document analyzes potential impacts of the alternatives, including the proposed action. These alternatives are programmatic in that they are plans for conducting the UMTRA Ground Water Project. The alternatives do not address site-specific ground water compliance. This PEIS is a planning document that will provide a framework for conducting the Ground Water Project; assess the potential programmatic and environmental impacts of conducting the UMTRA Ground Water Project; provide a method for determining the site-specific ground water compliance strategies; and provide data and information that can be used to prepare site-specific environmental impacts analyses documents more efficiently

  8. Romanian regulatory framework for uranium mining and milling (present and future)

    In Romania, all operations in the nuclear field, including uranium mining and milling, are regulated by Law no. 111/1996 (republished in 1998), regarding the safe conduct of nuclear activities. These activities can be performed only on the basis of an authorization released by the national regulatory authority, i.e. the National Commission for Nuclear Activities Control. The specific requirements which must be carried out by the owner of an operating licence for a uranium mining and milling operation are stipulated by the Republican Nuclear Safety Norms for Geological Research, Mining and Milling of Nuclear Raw Materials. These regulatory requirements have been in force since 1975. The regulatory norms include provisions that the effective dose limit for workers should not exceed 50 mSv/year and also that liquid effluents released into surface waters must have a content of natural radioactive elements that meets the standards for drinking water. The norms do not contain provisions concerning the conditions under which the mining sites and the uranium processing facilities can be shut down and decommissioned. The norms also do not contain requirements regarding either the rehabilitation of environments affected by abandoned mining and milling activities, nor criteria for the release of the rehabilitated sites for alternative uses. To implement the provisions of Council Directive 96/29 EURATOM in Romania, new Fundamental Radiological Protection Norms have been approved and will soon be published in the 'Monitorul Official' (Official Gazette of Romania). One of the main provisions of these norms is the reduction of the effective dose limit for the workers to 20 mSv/year. Changes in the Republican Nuclear Safety Norms for Geological Research, Mining and Milling of Nuclear Raw Materials, are also planned; these changes will be consistent with the Fundamental Radiological Protection Norms. To cover existing gaps, the new norms for uranium mining and milling will include

  9. Probabilistic calculation of dose commitment from uranium mill tailings

    The report discusses in a general way considerations of uncertainty in relation to probabilistic modelling. An example of a probabilistic calculation applied to the behaviour of uranium mill tailings is given

  10. Environmental Development Plan: uranium mining, milling, and conversion

    This Environmental Development Plan (EDP) identifies the planning and management requirements and schedules needed to evaluate and assess the environmental, health, and safety (EH and S) aspects of the uranium mining, milling, and conversion technologies. The plan represents the collective perceptions of EH and S concerns and requirements and knowledge of ongoing research programs of most of the Federal agencies involved in significant EH and S R and D program management, standards setting, or regulatory activities associated with uranium mining, milling, and conversion

  11. Abandoned Uranium Mines (AUM) Site Screening Map Service, 2016, US EPA Region 9

    U.S. Environmental Protection Agency — As described in detail in the Five-Year Report, US EPA completed on-the-ground screening of 521 abandoned uranium mine areas. US EPA and the Navajo EPA are using...

  12. Abandoned Uranium Mine (AUM) Site Screening Map, 2016, US EPA Region 9

    U.S. Environmental Protection Agency — As described in detail in the Five-Year Report, US EPA completed on-the-ground screening of 521 abandoned uranium mine areas. US EPA and the Navajo EPA are using...

  13. Uranium Mines and Mills: Wismut Environmental Remediation Project (Germany). Appendix V

    From 1946 to 1990, the Soviet–German Wismut Company produced 231 000 tonnes of uranium and became the world’s fourth largest uranium producer at that time. Owing to the mining of low grade ore, about 800 million tonnes of waste rock materials, radioactive sludges and overburden material were deposited at the sites. The mining and milling activities resulted in seriously affected and devastated areas of about 10 000 km² in the federal states Saxony and Thuringia, in the former East Germany. In 1990, after German re-unification, uranium production ceased and the German Government was faced with one of its largest ecological and economic challenges: Wismut transitioned immediately from production to decommissioning without any preparation or preplanning. Since 1991, the national corporation Wismut GmbH has been charged with decommissioning of the mines, mills and other facilities and with the rehabilitation of the sites. The German Government initially earmarked a total of €6.4 billion to remediate the uranium mining and milling legacy at the affected sites. Current estimates predict total project costs of €7 billion. The overall project includes: — Abandoning and flooding underground mines; — Relocating and covering waste rock piles; — Dewatering and geochemically stabilizing tailings management facilities; — Demolishing structures and buildings; — Treating contaminated water; — Site clearance; — Site rehabilitation

  14. Bioaccessibility of U, Th and Pb in particulate matter from an abandoned uranium mine

    Millward, Geoffrey; Foulkes, Michael; Henderson, Sam; Blake, William

    2016-04-01

    Currently, there are approximately 150 uranium mines in Europe at various stages of either operation, development, decommissioning, restoration or abandonment (wise-uranium.com). The particulate matter comprising the mounds of waste rock and mill tailings poses a risk to human health through the inadvertent ingestion of particles contaminated with uranium and thorium, and their decay products, which exposes recipients to the dual toxicity of heavy elements and their radioactive emissions. We investigated the bioaccessibility of 238U, 232Th and 206,214,210Pb in particulate samples taken from a contaminated, abandoned uranium mine in South West England. Sampling included a mine shaft, dressing floor and waste heap, as well as soils from a field used for grazing. The contaminants were extracted using the in-vitro Unified Bioaccessibility Research Group of Europe Method (UBM) in order to mimic the digestion processes in the human stomach (STOM) and the combined stomach and gastrointestinal tract (STOM+INT). Analyses of concentrations of U, Th and Pb in the extracts were by ICP-MS and the activity concentrations of radionuclides were determined on the same particles, before and after extraction, using gamma spectroscopy. 'Total' concentrations of U, Th and Pb for all samples were in the range 57 to 16,200, 0.28 to 3.8 and 69 to 4750 mg kg‑1, respectively. For U and Pb the concentrations in the STOM fraction were lower than the total and STOM+INT fractions were even lower. However, for Th the STOM+INT fractions were higher than the STOM due to the presence of Th carbonate species within the gastrointestinal fluid. Activity concentrations for 214Pb and 210Pb, including total, STOM and STOM+INT, were in the range 180 to <1 Bq g‑1 for the dressing floor and waste heap and 18 to <1 Bq g‑1 for the grazing land. Estimates of the bioaccessible fractions (BAFs) of 238U in the most contaminated samples were 39% and 8% in the STOM and STOM+INT, respectively, whereas the

  15. Uranium mill tailings cleanup: Federal leadership at last

    The Department of Energy has proposed legislation that would allow it to enter into cooperative agreements with various States to clean up residual radioactive materials--commonly called uranium mill tailings--at 22 inactive uranium mills. About 25 million tons of mill tailings have accumulated at these sites since the 1940s. GAO analyzed the need for, and adequacy of, the proposed legislation and recommends that the cleanup program be endorsed. While the Federal Government has no apparent legal responsibility for such a cleanup, it does have a moral responsibility since the mills primarily produced uranium for Federal programs. Further, it is the only organization able to undertake such a cleanup program on a comprehensive basis. GAO also suggests several areas where the proposed legislation could be strengthened

  16. Radiation protection in uranium mining and milling industry

    The first phase of the Nuclear Fuel Cycle is exploration for uranium and the next is mining and milling of uranium ore. This phase is mostly characterised by low levels of radioactivity and radiation exposure of the workers involved. Yet it is a paradoxical truth that incidence of cancer among the work force, especially miners, due to occupational radiation exposure (from radon and decay products) has been proved only in uranium mines in the entire Nuclear Fuel Cycle. Of course such incidence occurred before the detrimental effect of radiation exposure was realised and understood. Therefore it is important to familiarise oneself with the radiation hazards prevalent in the uranium mining and milling facilities so as to take appropriate remedial measures for the protection of not only the workers but also the public at large. There are both open cast and underground uranium mines around the world. Radiation hazards are considerably less significant in open cast mines than in underground mines unless the ore grade is very high. By default therefore the discussion which ensues relates mainly to radiation hazards in underground uranium mines and associated milling operations. The discussion gives a brief outline of typical uranium mine and mining and milling operations. This is followed by a description of the radiation hazards therein and protection measures that are to be taken to minimise radiation exposure. (author)

  17. The present situation and prospects of Ganzhou mining and milling of uranium ore

    According to the characteristics of natural uranium resources, occurrence of the condition of Ganzhou uranium mining process are used in the production levels of dry-fill method, in- situ blasting method, shallow hole Shrinkage Method. milling process using surface heap leaching, bacteria leaching, heap built underground in situ leaching of uranium ore mining and milling methods of enhanced leaching technology features. The hard rock uranium mining and milling process has been Ganzhou uranium research, elaborate of mining and milling technology used in uranium Ganzhou analysis of the status of various mining and milling technology to evaluate the prospects and development, analysis mining and milling technology in production applications. (author)

  18. Uranium mine and mill tailings management in Canada: Present status and future directions

    Approximately 120 million tonnes of uranium mine and mill tailings have been accumulated to date in Canada. Uranium mines operating prior to the early 1960s used tailings management practices similar to those employed by other metal mines; that is, liquid and solid wastes were deposited in local topographic depressions or lakes without special treatment and were eventually abandoned. New emphasis on health and environmental quality in the 1970s resulted in concern about the management of uranium mine and mill wastes, which contain radionuclides, heavy metals, process reagents, and acid generated in tailings. Current practice for mine and mill waste management requires engineered containment structures for the storage of wastes. Liquid effluent from the primary containment facility is decanted into secondary ponds where it can be chemically treated. Addition of barium chloride to the effluents produces a radium/barium precipitate which settles out as a sludge. The liquid effluent is then re-used as process water or released into the environment when it meets water quality standards. Tailings are covered and vegetation planted for stabilization. Government and industry research and development programmes are under way on abandoned, inactive and active tailings to determine the magnitude of environmental contamination, and to investigate the physical and biological pathways, rates of migration and processes by which radioactive and chemical contaminants can be released from the tailings. Current trends in tailings management include deposition of thickened and filtered tailings, sub-aerial deposition, stacking of tailings to increase the capacity of tailings impoundments, deposition of tailings in mined-out pits, alternative uranium recovery methods to reduce process chemicals in effluent, and possibly deep lake disposal

  19. Uranium Mill Tailings Remedial Action 1993 Roadmap

    The 1993 Roadmap for the Uranium Mill Tailings Remedial Action (UMTRA) Project office is a tool to assess and resolve issues. The US Department of Energy (DOE) UMTRA Project Office uses the nine-step roadmapping process as a basis for Surface and Groundwater Project planning. This is the second year the Roadmap document has been used to identify key issues and assumptions, develop logic diagrams, and outline milestones. This document is a key element of the DOE planning process. A multi-interest group used the nine-step process to focus on issues, root cause analysis and resolutions. This core group updated and incorporated comments on the basic assumptions, then used these assumptions to identify issues. The list of assumptions was categorized into the following areas: institutional, regulatory compliance, project management, human resource requirements, and other site-specific assumptions. The group identified 10 issues in the analysis phase. All of the issues are ranked according to importance. The number one issue from the 1992 Roadmap, ''Lack of sufficient human resources,'' remained the number one issue in 1993. The issues and their ranking are as follows: Lack of sufficient human resources; increasing regulatory requirements; unresolved groundwater issues; extension of UMTRCA through September 30, 1998; lack of post-UMTRA and post-cell closure policies; unpredictable amounts and timing of Federal funding; lack of regulatory compliance agreements; problem with states providing their share of remedial action costs; different interests and priorities among participants; and technology development/transfer. The issues are outlined and analyzed in detail in Section 8.0, with a schedule for resolution of these issues in Section 9.0

  20. Uranium-mill-tailings conditioning technology

    Conditioning of uranium mill tailings involves the physico-chemical alteration of tailings to remove or immobilize mobile radionuclides and toxic trace elements before disposal in a repository. The principal immobilization approach under investigation is sntering tailings at high temperatures (1100 to 12000C) to radically alter the structure of tailings. This thermal stabilization at 12000C reduced radon emanation power for tailings sands by factors of 20 to 200 and for tailings fines by factors of 300 to 1100. Substantial reductions in the leachability of most contaminants have been found for thermally conditioned tailings. A conceptual thermal stabilization process has been developed wherein obsolete coal-fired rotary cement kilns perform the sintering. An economic analysis of this conceptual process has shown that thermal stabilization can be competitive at certain tailings sites with other remedial actions requiring the excavation, transportation, and burial of tailings in a repository. An analysis of the long-term radiological hazard posed by untreated tailings and by tailings conditioned by radionuclide removal has illustrated the necessity of extracting both 226Ra and 230Th to achieve long-term hazard reductions. Sulfuric acid extraction of residual mineral values and important radionuclides from tailings has been investigated. Concentrated H2SO4 can extract up to 80% of the 226Ra, 70% of the Ba, and 90% of the 230Th from tailings in a single stag extraction. An economic analysis of a sulfuric acid leach process was made to determine whether the value of minerals recovered from tailings would offset the leaching cost. For one relatively mineral-rich tailings pile, the U and V values would more than pay for the leaching step and would contribute about 60% of the costs of moving and burying the tailings at a new site

  1. Current practices and options for confinement of uranium mill tailings

    At the United Nations Conference on the Human Environment, which took place in Stockholm from 4 to 6 June 1972, national governments were asked to explore, with the International Atomic Energy Agency and other appropriate international organizations, international co-operation on radioactive waste matters including those of mining and tailings disposal. Since that time the IAEA has been active in the field of uranium and thorium mill tailings management. As part of this activity, the present report describes current practices and options for confinement of uranium mill tailings. It is addressed to technical and administrative personnel who are involved in planning and implementing national and industrial programmes on the management of such tailings. In 1974 and 1975 the IAEA convened meetings of experts to review matters of interest and importance in the management of uranium and thorium mine and mill tailings. These activities led to the publication in 1976 of Management of Wastes from the Mining and Milling of Uranium and Thorium Ores, a Code of Practice and Guide to the Code, IAEA Safety Series No. 44. As a continuation of this activity, the IAEA is here dealing more specifically with the design and siting considerations for the management of uranium mill tailings

  2. Mortality patterns among a retrospective cohort of uranium mill workers

    The long-term health effects associated with the milling of uranium ore are of interest particularly because of exposures to uranium and thorium-230. Excess risks of pulmonary and lymphatic malignancies have been suggested by previous epdiemiologic studies of persons milling or smelting uranium ores, and nephrotoxic effects of uranium have been reported in both man and animals. To test these three previously reported associations and to assess all cause-specific mortality patterns among uranium mill workers, we carried out a retrospective cohort study of 2002 uranium millers employed in any of seven mills at least one year before 1972. Ninety-eight percent (98%) followup of the cohort through 1977 resulted in 533 deaths observed versus 605 expected from US White male mortality rates. Mortality from most causes was lower than expected. Significant excess risks were found only for nonmalignant respiratory disease and miscellaneous accidents but not for any of the three diseases of a priori interest. However, nonsignificant excesses were found for lymphatic malignancies after 20 years latency and for death due to chronic nephritis among short-term workers

  3. Paleoclimatic data applications: Long-term performance of uranium mill tailings repositories

    Waugh, W.J. [Environmental Sciences Lab., Grand Junction, CO (United States); Petersen, K.L. [Washington State Univ., Richland, WA (United States)

    1995-09-01

    Abandoned uranium mill tailings sites in the Four Corners region are a lasting legacy of the Cold War. The U.S. Department of Energy (DOE) is designing landfill repositories that will isolate hazardous constituents of tailings from biological intrusion, erosion, and the underlying aquifer for up to 1,000 years. With evidence of relatively rapid past climate change, and model predictions of global climatic variation exceeding the historical record, DOE recognizes a need to incorporate possible ranges of future climatic and ecological change in the repository design process. In the Four Corners region, the center of uranium mining and milling activities in the United States, proxy paleoclimatic records may be useful not only as a window on the past, but also as analogs of possible local responses to future global change. We reconstructed past climate change using available proxy data from tree rings, packrat middens, lake sediment pollen, and archaeological records. Interpretation of proxy paleoclimatic records was based on present-day relationships between plant distribution, precipitation, and temperature along a generalized elevational gradient for the region. For the Monticello, Utah, uranium mill tailings site, this first approximation yielded mean annual temperature and precipitation ranges of 2 to 10{degrees} C, and 38 to 80 cm, respectively, corresponding to late glacial and Altithermal periods. These data are considered to be reasonable ranges of future climatic conditions that can be input to evaluations of groundwater recharge, radon-gas escape, erosion, frost penetration, and biointrusion in engineered earthen barriers designed to isolate tailings.

  4. Radioactive contamination of the environment as a result of uranium production: a case study at the abandoned Lincang uranium mine, Yunnan Province, China

    XU; Lechang(

    2002-01-01

    [1]Gillmore, G. K., Grattan, J., Pyatt, F. B. et al., Radon, water and abandoned metalliferous mines in the UK: Environmental and Human Health Implications, in Uranium in the Aquatic Environment, Proceedings of the International Conference Uranium Mining and Hydrogeology III and the International Mine Water Association Symposium (eds. Merkel, B. J., Planer-Friedrich, B., Wolkersdorfer, C.), Berlin: Springer, 2002, 65-76.[2]GB/T 16146-1995, Standards for Controlling Radon Concentration in Dwellings (in Chinese).[3]Kinze, M., Dose limits and maximum concentration limits (MCL's) for radionuclides--Implication on remediation of uranium mining and milling facilities in Saxony Germany, in Uranium in the Aquatic Environment, Proceedings of the International Conference Uranium Mining and Hydrogeology III and the International Mine Water Association Symposium (eds. Merkel, B. J., Planer-Friedrich, B., Wolkersdorfer, C.), Berlin: Springer, 2002, 1-7.[4]Xu, L. C., Wang, Y. X., Environmental issues and remedial actions of the abandoned Lincang uranium mine in China, in Uranium in the Aquatic Environment, Proceedings of the International Conference Uranium Mining and Hydrogeology III and the International Mine Water Association Symposium (eds. Merkel, B. J., Planer-Friedrich, B., Wolkersdorfer, C.), Berlin: Springer, 2002, 709-718.[5]International Atomic Energy Agency, Decommissioning of Facilities for Mining and Milling of Radioactive Ores and Closeout of Residues, Technical Report Series No. 362, Vienna: IAEA, 1994, 70.[6]OECD/NEA (Nuclear Energy Agency), Environment Activities in Uranium Mining and Milling, A Joint NEA/IAEA Report, Paris: Pubie en Francais Sous le Titre, 1999, 23-26.[7]Xu, L. C., Dai, X., Tan, T. et al., Environment Impact Report on Environmental Treatment Engineering of Decommissioning Lincang Uranium Mine (Feasibility studies stages) ( in Chinese), 1999.[8]Zhang Zhihui, Measurement Methods of Radon and Its Daughters in

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

    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

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

    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.

  7. Accelerated aging tests of liners for uranium mill tailings disposal

    Barnes, S.M.; Buelt, J.L.; Hale, V.Q.

    1981-11-01

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing.

  8. Characterization of surface soils at a former uranium mill.

    Johnson, J A; Meyer, H R; Vidyasagar, M

    2006-02-01

    Dawn Mining Company operated a uranium mill in Stevens County, Washington, from 1957 to 1982, to process ore from the Midnite Mine, and from 1992 through 2000, to extract uranium from mine water treatment sludge. The mill was permanently shut down in 2001 when the Dawn Mining Company radioactive materials license was amended to allow direct disposal of water treatment sludge to a tailings disposal area at the mill. The mill building was demolished in 2003. Site soil characterization took place in 2004. Soil cleanup is ongoing. Contaminated soils on the site were characterized using a GPS-based gamma scanning system. A correlation between shielded gamma exposure rate and concentration of Ra in surface soils was developed. Subsurface soils were sampled using backhoe trenches. This system proved efficient and accurate in guiding development of the remedial action planning for the site and subsequent soil cleanup. PMID:16404186

  9. Review of environmental aspects of uranium mill operations: industry's view

    Problems faced by uranium mill operators in complying with new environmental regulations and guidelines are discussed. It is pointed out that valid data must be available in order to evaluate impacts on the environment, to determine background radiation levels, to measure the effectiveness of control techniques, and to determine compliance with standards and regulations. Specific problem areas facing mill operators today and some of the unresolved questions include: sampling methods and equipment for radon in ambient air, measurements of radon and radon daughter exposures of people, radon emanation rate meaurements applicable to monitoring mill tailings, the calibration of γ counters, measurements of population doses, regulations concerning mill tailings reclamation nd stabilization, and the comparative value of in-vivo counting and uranium urinary excretion measurements for monitoring personnel

  10. Accelerated aging tests of liners for uranium mill tailings disposal

    This document describes the results of accelerated aging tests to determine the long-term effectiveness of selected impoundment liner materials in a uranium mill tailings environment. The study was sponsored by the US Department of Energy under the Uranium Mill Tailings Remedial Action Project. The study was designed to evaluate the need for, and the performance of, several candidate liners for isolating mill tailings leachate in conformance with proposed Environmental Protection Agency and Nuclear Regulatory Commission requirements. The liners were subjected to conditions known to accelerate the degradation mechanisms of the various liners. Also, a test environment was maintained that modeled the expected conditions at a mill tailings impoundment, including ground subsidence and the weight loading of tailings on the liners. A comparison of installation costs was also performed for the candidate liners. The laboratory testing and cost information prompted the selection of a catalytic airblown asphalt membrane and a sodium bentonite-amended soil for fiscal year 1981 field testing

  11. Underground Milling of High-Grade Uranium Ore

    There are many safety and technical issues involved in the mining and progressing of high grade uranium ores such as those exploited in Northern Canada at present. With more of this type of mine due to commence production in the near future, operators have been looking at ways to better manage the situation. The paper describes underground milling of high-grade uranium ore as a means of optimising production costs and managing safety issues. In addition the paper presents some examples of possible process flowsheets and plant layouts that could be applicable to such operations. Finally an assessment of potential benefits from underground milling from a variety of viewpoints is provided. (author)

  12. Biogeochemistry of uranium mill wastes program overview and conclusions

    The major findings and conclusions are summarized for research on uranium mill tailings for the US Department of Energy and the US Nuclear Regulatory Commission. An overview of results and interpretations is presented for investigations of 222Rn emissions, revegetation of tailings and mine spoils, and trace element enrichment, mobility, and bioavailability. A brief discussion addresses the implications of these findings in relation to tailings disposal technology and proposed uranium recovery processes

  13. Transportation of the MOAB Uranium Mill Tailings to White Mesa Mill by Slurry Pipeline

    Hochstein, R. F.; Warner, R.; Wetz, T. V.

    2003-02-26

    The Moab uranium mill tailings pile, located at the former Atlas Minerals Corporation site approximately three miles north of Moab, Utah, is now under the control of the US Department of Energy (''DOE''). The location of the tailings pile adjacent to the Colorado River, and the ongoing contamination of groundwater and seepage of pollutants into the river, have lead to the investigation, as part of the final site remediation program, of alternatives to relocate the tailings to a qualified permanent disposal site. This paper will describe the approach being taken by the team formed between International Uranium (USA) Corporation (''IUC'') and Washington Group International (''WGINT'') to develop an innovative technical proposal to relocate the Moab tailings to IUC's White Mesa Mill south of Blanding, Utah. The proposed approach for relocating the tailings involves using a slurry pipeline to transport the tailings to the White Mesa Mill. The White Mesa Mill is a fully licensed, active uranium mill site that is uniquely suited for permanent disposal of the Moab tailings. The tailings slurry would be dewatered at the White Mesa Mill, the slurry water would be recycled to the Moab site for reuse in slurry makeup, and the ''dry'' tailings would be permanently disposed of in an approved below grade cell at the mill site.

  14. 77 FR 35431 - Final Alternative Soils Standards for the Uravan, CO, Uranium Mill

    2012-06-13

    ... COMMISSION Final Alternative Soils Standards for the Uravan, CO, Uranium Mill AGENCY: Nuclear Regulatory Commission. ACTION: Notice of Uranium milling alternative standards. SUMMARY: This document announces that on... uranium mill tailings (11e.(2) byproduct material). Six Agreement States have this authority as part...

  15. 76 FR 70170 - Proposed Alternative Soils Standards for the Uravan, Colorado Uranium Mill

    2011-11-10

    ... COMMISSION Proposed Alternative Soils Standards for the Uravan, Colorado Uranium Mill AGENCY: Nuclear Regulatory Commission. ACTION: Uranium milling alternative standards. SUMMARY: By letter dated October 10... Agreement States to specifically amend their Agreements to regulate uranium mill tailings (11e.(2)...

  16. Uranium Mill and ISL Facility Database

    U.S. Environmental Protection Agency — An Excel database on NRC and Agreement State licensed mills providing status, locational/operational/restoration data, maps, and environmental reports including...

  17. Geochemistry of natural wetlands in former uranium milling sites (eastern Germany) and implications for uranium retention

    Schöner, Angelika; Noubactep, Chicgoua; Büchel, Georg; Sauter, Martin

    2008-01-01

    Discharge from former uranium mining and milling areas is world wide a source of elevated uranium contents in wetlands. The efficiency of organic rich wetland environments for entrapment and accumulation of uranium was assessed in this work using hydrogeochemical field studies of natural small-sized wetlands in Thuringia and Saxony, Eastern Germany. The objective was to estimate, if artificial wetlands can be used in a similar way: as a sustainable 'passive' treatment methodology. World wide,...

  18. Identification of geobacter populations in the uranium mill tailings Shiprock

    Geobacter - specific primers were used for construction of a 16S rDNA library for a water sample collected from uranium mill tailings near Shiprock (Sh853) in the USA . Most of the retrieved sequences were affiliated with different Geobacter species, however sequences related to other δ -Proteobacteria were identified as well. (authors)

  19. Humeca Uranium Mill. Nuclear Regulatory Commission's final environmental statement

    The Humeca Uranium Mill is a carbonate-leach uranium ore refining plant with a capacity of about 500 tons of ore per day. Although the present licensing action does not extend to mining, the statement considers the environmental impact of the combined mining and milling project to be conducted by Rio Algom Corporation. The environmental impact, including adverse and beneficial environmental effects of the Rio Algom Uranium Mill, is as follows. (1) Temporary (about 10 years) reassignment of use of about 120 acres of land out of the total 2,573 acres controlled by Rio Algom Corporation. (2) The removal of an estimated 8.4 million pounds of uranium concentrates as a natural resource. This material will eventually be used to produce approximately 6.09 x 106 megawatt-days of electricity. (3) Removal and diversion of approximately 100 gallons per minute of local groundwater. (4) Stimulation of the local economy through payment of taxes and direct employment of about 200 persons in San Juan County over the next 10 years. Rio Algom estimates they will pay out over $11 million in salaries over this period of time. (5) The creation of stabilized tailings piles covering about 45 acres involving approximately 1,850,000 tons of solids containing solidified waste chemical and radioactive uranium and its daughter products. (6) Discharge of small quantities of chemicals and radioactive materials (that are not expected to produce discernible effects) into the local environs

  20. Molecular analysis of the bacterial diversity in uranium mill tailings

    A culture-independent molecular approach has been applied to investigate the bacterial diversity in three uranium contaminated sites. The three analysed soil samples have been collected from the uranium waste pile Haberland near Johanngeorgenstadt (Germany), from the uranium mill tailings in Gunnison, Colorado (USA) and from the uranium mill tailings in Shiprock, New Mexico (USA). The 16S rDNA fragments which has been isolated through direct lysis of the whole-DNA were amplified by the use of the universal primers 16S43f and 16S1404r and cloned. With restriction fragment length polymorphismus (RFLP) were the clones screened and one representative of all RFLP types that occurred more than once in the clone library was sequenced and analysed. In spite of the contamination a considerable diversity and significant differences in the composition of the natural bacterial communities in these three sites have been found. In the sample collected from the waste pile Haberland near Johanngeorgenstadt α-Proteobacteria and representatives of the Holophaga/Acidobacterium were numerically predominant. The distribution of bacteria in the sample collected from uranium mill tailings Gunnison was very similar to those found in the Haberland waste pile, but there were found besides α-Proteobacteria and representatives of Holophaga/Acidobacterium a lot of γ-Proteobacteria. The structure of the bacterial community in the sample collected from the uranium mill tailings Shiprock was significantly different. Only some representatives of the Holophaga/Acidobacterium and α-Proteobacteria were represented. Large populations of Bacilli, γ-Proteobacteria and green non sulfur bacteria were dominant in this sample. (orig.)

  1. Lucky Mc Uranium Mill. Draft environmental statement

    The Environmental Impact Statement addressed the following: the existing environment; operations; environmental impacts; environmental effects of accidents; monitoring programs and other mitigating measures; unavoidable adverse environmental impacts; relationship between short-term uses of the environment and long-term productivity; irreversible and irretrievable commitments of resources; alternatives; and NRC benefit-cost summary for the Lucky Mc Mill

  2. Current issues (and problems) in uranium mine and mill site remediation

    The environmental impact of the mining and milling of uranium ores is similar to that of traditional metal mining with the added factor of the characteristic radioactivity in uranium ores. Residues of these ores therefore generate specific potential hazards requiring special precautions on a site specific basis, as well as special regulatory procedures and controls to ensure protection of public health and safety in the long term. There are strong indications that on a global scale U-mining tailings management and remediation-activities are steadily becoming governed by the ultimate goal of sustainable stabilization and re-establishment of a healthy environment, rather than by immediate or short term needs. In Central Europe rehabilitation of uranium mining and milling districts has only started. Some problems are listed as follows: (1) Limitation, long term control and prediction of aquatic and atmospheric dispersal of contaminants from tailings impoundments, waste rock dumps and abandoned underground mines, (2) Dewatering of tailings (large volumes), (3) Design of cover systems and inhibition of microbian process, (4) Controlled flooding of extensive underground mine workings and related prognosis and control of containment dispersion, (5) Reduction of Rn-exhalation during the flooding process and after mine abandonment, in particular in areas close to densely populated regions, (6) Determination of long term radiological impacts on residents near sources of contamination and identification of natural background levels, (7) Identification of critical containment pathways that remain active, (8) Conception and implementation of a comprehensive monitoring system for all pathways which would operate on a long term basis, (9) Limitation of mine water drainage to be treated and decontaminated and of resulting sludges (in considerable quantities) to be disposed of and which would have to be classified as hazardous waste in the future due to their radionuclide content

  3. A review of international uranium mill tailings management practice

    Uranium tailings management practices adopted in various countries or, more specifically, uranium mining areas, tend to reflect several factors: the age of the mining and milling operation, the mining method (e.g. underground vs open pit), the ore grade, the regional geology, hydrogeology and geochemistry, the topography and geomorphology of the area, climatic conditions, and governmental regulations. Of these, only the last, governmental regulations, are by definition nationalistic in scope. However, even these tend to reflect the other factors which are imposed by nature. As a result of these factors, international mill tailings management strategies vary greatly and include both effluent and non-effluent producing systems, above and below grade disposal schemes, lined and unlined 'ponds' above and below water (both surface water and groundwater) emplacement, 'wet' and 'dry' methods of disposal, and pre-treatment of the gangue in the mill. This paper reviews current (and, where applicable, past) uranium mill tailings management practice(s) in Africa, Australia, Europe and North America in the context of the above factors

  4. Domestic uranium mining and milling industry: 1986 viability assessment

    This report presents the fourth annual assessment of the domestic uranium mining and milling industry's resource capability, supply response capability, financial capability, and import commitment dependency. The data and analysis in support of this assessment and the report itself have been developed pursuant to Public Law 97-415, the Nuclear Regulatory Commission (NRC) Authorization Act of 1982. The report provides information on recent uranium supply, demand, and marketing conditions, as well as projections of the domestic uranium industry's ability to continue to supply the needs of the domestic nuclear power industry through the year 2000. Industry capability is assessed under a variety of assumed conditions with respect to hypothetical disruptions of uranium imports. 13 refs., 26 figs., 37 tabs

  5. Innovations over old plant techniques in Jaduguda Uranium Mill expansion

    India's first Uranium Mines and Mills was commissioned at Jaduguda in 1968. The plant's flowsheet was developed at BARC after extensive tests, for extraction of uranium as yellow cake from the ore. The designed capacity of the process plant was initially 1000 MT/day of ore treatment supplied from nearby mines. Subsequently, due to growing demand of uranium fuel, opening of Bhatin mines and setting up of three plants for recovery of uranium mineral from copper tailings of Hindustan Copper Ltd. was perceived. The capacity of the Jaduguda Plant was increased to 1400 MT/day in 1987 to meet this requirement. A new mine at Narwapahar is under development which will necessitate augmentation of the capacity of the Jaduguda plant by 700 MT/day. Major changes are contemplated in equipment selection for the expansion besides incorporation of a high degree of automation based on microprocessor technology which are discussed in this paper. (author)

  6. Asphalt emulsion sealing of uranium mill tailings. 1979 annual report

    Hartley, J.N.; Koehmstedt, P.L.; Esterl, D.J.; Freeman, H.D.

    1980-06-01

    Uranium mill tailings are a source of low-level radiation and radioactive materials that may be released into the environment. Stabilization or disposal of these tailings in a safe and environmentally sound way is necessary to minimize radon exhalation and other radioactive releases. One of the most promising concepts for stabilizing uranium tailings is being investigated at the Pacific Northwest Laboratory: the use of asphalt emulsion to contain radon and other potentially hazardous materials in uranium tailings. Results of these studies indicate that radon flux from uranium tailings can be reduced by greater than 99% by covering the tailings with an asphalt emulsion that is poured on or sprayed on (3.0 to 7.0 mm thick), or mixed with some of the tailings and compacted to form an admixture seal (2.5 to 15.2 cm) containing 18 wt % residual asphalt.

  7. Asphalt emulsion sealing of uranium mill tailings. 1979 annual report

    Uranium mill tailings are a source of low-level radiation and radioactive materials that may be released into the environment. Stabilization or disposal of these tailings in a safe and environmentally sound way is necessary to minimize radon exhalation and other radioactive releases. One of the most promising concepts for stabilizing uranium tailings is being investigated at the Pacific Northwest Laboratory: the use of asphalt emulsion to contain radon and other potentially hazardous materials in uranium tailings. Results of these studies indicate that radon flux from uranium tailings can be reduced by greater than 99% by covering the tailings with an asphalt emulsion that is poured on or sprayed on (3.0 to 7.0 mm thick), or mixed with some of the tailings and compacted to form an admixture seal (2.5 to 15.2 cm) containing 18 wt % residual asphalt

  8. Domestic uranium mining and milling industry. 1984 viability assessment

    This report presents the second annual assessment of the domestic uranium mining and milling industry's resource capability, supply response capability, financial capability, and import commitment dependency. The data and analysis in support of this assessment and the report itself have been developed pursuant to requirements set forth in Section 23(b) of Public Law 97-415, the Nuclear Regulatory Commission (NRC) Authorization Act, which was enacted on January 4, 1983. The report provides information on recent uranium supply, demand, and marketing conditions and projections of the domestic uranium industry's ability to continue to supply the needs of the domestic nuclear power industry through the year 2000. Industry capability is assessed under a variety of assumed conditions with respect to hypothetical disruptions of uranium imports

  9. Review of fugitive dust control for uranium mill tailings

    An immediate concern associated with the disposal of uranium mill tailings is that wind erosion of the tailings from an impoundment area will subsequently deposit tailings on surrounding areas. Pacific Northwest Laboratory (PNL), under contract to the U.S. Nuclear Regulatory Commission, is investigating the current technology for fugitive dust control. Different methods of fugitive dust control, including chemical, physical, and vegetative, have been used or tested on mill tailings piles. This report presents the results of a literature review and discussions with manufacturers and users of available stabilization materials and techniques

  10. Leaching of 226Ra from components of uranium mill tailings

    Landa, E.R.

    1991-01-01

    A sequential extraction procedure was used to characterize the geochemical forms of 226Ra retained by mixtures of quartz sand and a variety of fine-grained rock and mineral species. These mixtures had previously been exposed to the sulfuric acid milling liquor of a simulated acid-leach uranium milling circuit. For most test cases, the major fraction of the 226Ra was extracted with 1 mol/1 NH4Cl and was deemed to be exchangeable. However, 226Ra retained by the barite-containing mixture was resistant to both 1 mol/1 NH4Cl and 1 mol/HCHCl extraction. ?? 1991.

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

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

  12. International developments in uranium mining and mill site remediation

    At the end of production, mine sites, mill sites, tailings ponds, heap leaching residues in uranium mining districts world-wide have to be remediated in a responsible and sustainable manner in order to minimize long term environmental impacts. Current practice, regulatory environments and rehabilitation objectives in some of the most important uranium producing countries are briefly characterized as well as applicable radioprotection and geotechnical criteria. Important local and regional variables are outlined which determine optimal site specific solutions. Examples from Europe and North America are shown. Monitoring and control requirements as well as areas of current and necessary research and development are identified

  13. Uranium mill tailings remedial action project real estate management plan

    This plan summarizes the real estate requirements of the US Department of Energy's (DOE) Uranium Mill Tailings Action (UMTRA) Project, identifies the roles and responsibilities of project participants involved in real estate activities, and describes the approaches used for completing these requirements. This document is intended to serve as a practical guide for all project participants. It is intended to be consistent with all formal agreements, but if a conflict is identified, the formal agreements will take precedence

  14. The chemistry of 226Ra in the uranium milling process

    Uranium mining, ore crushing, grinding and leaching can substantially redistribute radium in the environment. Solvent extraction or other separation processes leave mill tailings with high 226Ra concentration. Radium is readily adsorbed on the surfaces of leached solids or coprecipitated with barium sulfates. More solid ore phase studies are required to identify all the physico-chemical mechanisms controlling 226Ra dissolution from leaching ore-liquor systems. 29 refs, 5 figs, 4 tabs

  15. Long-term stabilization of uranium mill tailings

    The primary hazard associated with uranium mill tailings is exposure to a radioactive gas, radon-222, the concentration of which has been correlated with the occurrence of lung cancer. Previous studies on radon attenuation conclude that the placement of earthen cover materials over the tailings is the most effective technique for reducing radioactive emissions and dispersal of tailings. The success of such a plan, however, is dependent on ensuring the long-term integrity of these cover materials. Soil erosion from water and wind is the major natural cause of destabilizing earthen cover materials. Field data related to the control of soil loss are limited and only indirectly apply to the problem of isolation of uranium mill tailings over very long time periods (up to 80,000 a). However, sufficient information is available to determine benefits that will result from the changes in specific design variables and to evaluate the need for different design strategies among potential disposal sites. The three major options available for stabilization of uranium mill tailings are: rock cover, soil and revegetation, or a combination of both on different portions of the tailings cover. The optimal choice among these alternatives depends on site-specific characteristics such as climate and local geomorphology and soils, and on design variables such as embankment, heights and slopes, modification of upstream drainage, and revegetation practices. Generally, geomorphic evidence suggests that use of soil and vegetation alone will not be adequate to reduce erosion on slopes greater than about 5 to 9%

  16. The Canadian Nuclear Safety Commission Compliance Program for Uranium Mines and Mills

    The Canadian Nuclear Safety Commission (CNSC) is the principal nuclear regulator in Canada. The CNSC is empowered through the Nuclear Safety and Control Act (NSCA) and its associated regulations, to regulate the entire nuclear cycle which includes: uranium mining and milling, uranium refining and processing, fuel fabrication, power generation and nuclear waste management. A CNSC uranium mine licence is required by a proponent to site, prepare, construct, operate, decommission and abandon this nuclear facility. The CNSC licence is the legal instrument that authorizes the regulated activities and incorporates conditions and regulatory controls. Following a favourable Commission Tribunal decision to issue a licence to authorize the licensed activities, CNSC develops and executes a compliance plan of the licensee’s programs and procedures. The CNSC compliance plan is risk-informed and applies its resources to the identified higher risk areas. The compliance program is designed to encourage compliance by integrating three components: promotion, verification and enforcement and articulates the CNSC expectations to attain and maintain compliance with its regulatory requirements. The licensee performance is assessed through compliance activities and reported to the Commission to inform the licensing process during licence renewal. The application of the ongoing compliance assessment and risk management model ensures that deviations from impact predictions are addressed in a timely manner. The Uranium Mines and Mills Division of the CNSC are preparing to meet the challenges of the planned expansion of their Canadian uranium mining industry. The presentation will discuss these challenges and the measures required to address them. The Uranium Mines and Mills Division (UMMD) have adopted a structured compliance framework which includes formal procedures to conduct site inspections. New UMMD staff are trained to apply the regulations to licensed sites and to manage non

  17. Analysis of uranium urinalysis and in vivo measurement results from eleven participating uranium mills

    Uranium urinalysis and in vivo examination results obtained from workers at eleven uranium mills between 1978 and 1980 were evaluated. The main purpose was to determine the degree of the mills' compliance with bioassay monitoring recommendations given in the draft NRC Regulatory Guide 8.22 (USNRC 1978). The effect of anticipated changes in the draft regulatory guidance, as expressed to PNL in May 1982, was also studied. Statistical analyses of the data showed that the bioassay results did not reliably meet the limited performance criteria given in the draft regulatory guide. Furthermore, quality control measurements of uranium in urine indicated that detection limits at α = β = 0.05 ranged from 13 μg/l to 29 μg/l, whereas the draft regulatory guidance suggests 5 μg/l as the detection limit. Recommendations for monitoring frequencies given in the draft guide were not followed consistently from mill to mill. The results of these statistical analyses indicate a need to include performance criteria for accuracy, precision, and confidence in revisions of the draft Regulatory Guide 8.22. Revised guidance should also emphasize the need for each mill to continually test the laboratory performing urinalyses by submitting quality control samples (i.e., blank and spiked urine samples as open and blind test) to insure that the performance criteria are being met. Recommendations for a bioassay audit program are also given. 25 references, 15 figures, 17 tables

  18. Uranium and thorium mining and milling: material security and risk assessment

    Full text: At present physical protection for the front end of the nuclear fuel cycle is typically at a significantly lower level than at any other part of the nuclear fuel cycle. In view of past experiences (Israel, South Africa, Pakistan, India) it is feasible to take into consideration some generic threat scenarios, potentially resulting in loss of control over uranium or thorium, respectively their concentrates, such as: illegal mining of an officially closed uranium- or thorium mine; covert diversion of uranium- or thorium ore whilst officially mining another ore; covert transport of radioactive ore or product, using means of public rail, road, ship, or air transport; covert en route diversion of an authorized uranium- or thorium transport; covert removal of uranium-or thorium ore or concentrate from an abandoned facility. The Stanford-Salzburg database on nuclear smuggling, theft, and orphan radiation sources (DSTO) contains information on trafficking incidents involving mostly uranium, but also some thorium, from 30 countries in five continents with altogether 113 incidents in the period 1991 to 2004. These activities range from uranium transported in backpacks by couriers in Afghanistan, to a terrorist organization purchasing land in order to mine covertly for uranium in Australia, and the clandestine shipment of almost two tons of uranium hexafluoride from Asia to Africa, using the services of a national airline. Potential participants in such illegal operations range from entrepreneurs to members of organized crime, depending on the level of sophistication of the operation. End-users and 'customers' of such illegal operations are suspected to be non-state actors, organizations or governments involved in a covert operation with the ultimate aim to acquire a sufficient amount of nuclear material for a nuclear device. The actual risk for these activities to succeed in the acquisition of an adequate amount of suitable radioactive material depends on one or

  19. Asphalt emulsion sealing of uranium mill tailings

    The use of asphalt emulsion to contain radon and radium in uranium tailings is being investigated at the Pacific Northwest Laboratory. Results of these studies indicate that a radon flux reduction of greater than 99% can be obtained using either a poured-on/sprayed-on seal (3.0 to 7.0 mm thick) or an admix seal (2.5 to 15.2 cm thick) containing about 18 wt % residual asphalt. A field test was carried out at the Grand Junction tailings pile in order to demonstrate the sealing process. A reduction in radon flux ranging from 4.5 to greater than 99% (76% average) was achieved using a 15.2 cm (6 in.) admix seal with a sprayed-on top coat. A hydrostatic stabilizer was used to apply the admix. This was followed by compaction to form the radon seal. Overburden was applied to provide a protective soil layer over the seal. Included in part of the overburden was a herbicide to prevent root penetration

  20. Evaluation of environmental impacts of uranium mining and milling operations in Spain

    Uranium mining and production activities have been carried out by ENUSA since 1973. This report describes the evaluation of environmental aspects connected with uranium mining and milling. (author). 7 figs, 3 tabs

  1. Assessment of uranium exposure in a community near former uranium mining and milling

    The northern region of Karnes County, Texas has been the site of extensive mining and milling of uranium-238 (238U) for over 30 years. Measurements of 238U were conducted to test the hypothesis that past mining/milling efforts have increased the environmental burden of 238U in local residential areas. 238U concentrations and lead isotope ratios were measured by ICP-MS in soil, plant tissues, household furnace filters, carpet dusts and drinking water. Soil samples (n=75) were collected from the yards of previously studied homes at the surface and 30 cm subsurface. From each home carpet vacuums, filter entrapments and dust swabs were collected (total n=15) as were water wells samples when available (n=7). A site located over 8 miles south of the study area and with no history of mining or milling facilities was found to be consistently and statistically (p238U contamination in the study area from high grade imported ore. The water sample near the largest mining/milling operation compared to the control site, indicating leaching into the groundwater. Analysis of dust samples indicates indoor contamination as 238U was as much as 10X higher in homes from the mining/milling areas compared to the control region. Data thus far indicates that uranium contamination from mining/milling activities is likely to be the cause of the previously documented biological effects and suggests increased health risks for these residents

  2. Architecture and environmental restoration: Remediating uranium mill tailings from buildings

    The US Department of Energy (DOE) Grand Junction Projects Office (GJPO) manages the Uranium Mill Tailings Remedial Action (UMTRA) Program in Grand Junction, Colorado. This program is a congressionally mandated clean up of by-product waste that resulted from the extraction of yellow cake from uranium ore. The by-product waste, a fine sand commonly called open-quotes mill tailingclose quotes is contaminated with low-level radioactivity. These mill tailings were available to the community for use as construction material from approximately 1952 to 1966; their use as bedding material for concrete slabs, utilities, backfill materials, concrete sand, and mortar created unique remediation problems that required innovative solutions. This paper describes how design personnel approach the remediation of structures, the evaluation of the buildings, and the factors that must be considered in completing the remediation design. This paper will not address the health risks of the tailings in an inhabited space, the remediation of exterior areas, or the process of determining where the tailings exist in the building

  3. An ecological approach to the assessment of vegetation cover on inactive uranium mill tailings sites

    Vascular plants have been collected from abandoned or inactive uranium mill tailings in three mining areas in Canada. The collection was evaluated to determine some characteristics of vegetation development and to identify the plants which will persist on the sites. A total of 170 species were identified. Many of the species are widely distributed in North America, none has been reported as rare in any of the locations from which they were collected. Species richness was highest on Bancroft sites and lowest on Uranium City sites, though values were variable between sites. Forty-four per cent of the total number of species were found on only a single site. Only seven species occurred on more than half of the tailings sites and in all three mining areas. There was no difference between amended and unamended sites in terms of either species richness or species composition. There was no apparent relationship between species richness and either site size, site age or amendment history. The results of this survey suggest that the uranium mill tailings sites are at an early stage of colonization where the seed input from surrounding areas and the heterogeneity of the sites are factors determining species composition and species richness. The fate of an individual once it has reached the site will be determined by its ability to establish on the sites. A perennial growth habit and the ability to expand clonally are important characteristics of the species on the tailings. The species on the tailings are commonly found in a variety of habitats. Consistent with the observation that the tailings sites are at a stage of early colonization, we find that the few species widely distributed across sites are all characteristic pioneering species with wide environmental tolerances. These species included Populus tremuloides, P. balsamifera, Scirpus cyperinus, Equisetum arvense, Betula papyrifera, Achillea millefolium and Typha spp. The vegetation on the tailings is likely to be

  4. An occupational medical program for a 'model' uranium mill

    The basic purpose of occupational health programs in uranium milling are to insure that no employee receives an exposure to carcinogenic, mutagenic, teratogenic, highly toxic, pneumoconiosis-producing, or dangerous physical agents that could result in chronic or acute injury and to assure that significant concentrations or levels of the above are not present in either the plant or general environment. This paper defines a model mill as consisting of crushing, sizing, acid leach, separation, solvent extraction, drying and packaging operations and describes the employee health hazards associated with each. It also describes a type program consisting of a balanced combination of exposure monitoring and survey, air samples, personnel dosimetry, bioassay, training, medical surveillance, and emergency planning based on the employee exposure situation. Experience with such a program is also discussed, and some techniques of practically meeting the regulatory requirements and protecting the worker are outlined. (Auth.)

  5. Biogeochemical aspects of uranium mineralization, mining, milling, and remediation

    Highlights: • This work is a review of environmental effects of uranium mining and remediation. • Uranium biogeochemistry is described, with an emphasis on redox processes. • A discussion of the geochemistry of solution mining is included. • Coupled processes affecting elements that co-occur with uranium are presented. • Sustainability and lowering environmental impacts of uranium mining are discussed. - Abstract: Natural uranium (U) occurs as a mixture of three radioactive isotopes: 238U, 235U, and 234U. Only 235U is fissionable and makes up about 0.7% of natural U, while 238U is overwhelmingly the most abundant at greater than 99% of the total mass of U. Prior to the 1940s, U was predominantly used as a coloring agent, and U-bearing ores were mined mainly for their radium (Ra) and/or vanadium (V) content; the bulk of the U was discarded with the tailings (Finch et al., 1972). Once nuclear fission was discovered, the economic importance of U increased greatly. The mining and milling of U-bearing ores is the first step in the nuclear fuel cycle, and the contact of residual waste with natural water is a potential source of contamination of U and associated elements to the environment. Uranium is mined by three basic methods: surface (open pit), underground, and solution mining (in situ leaching or in situ recovery), depending on the deposit grade, size, location, geology and economic considerations (Abdelouas, 2006). Solid wastes at U mill tailings (UMT) sites can include both standard tailings (i.e., leached ore rock residues) and solids generated on site by waste treatment processes. The latter can include sludge or “mud” from neutralization of acidic mine/mill effluents, containing Fe and a range of coprecipitated constituents, or barium sulfate precipitates that selectively remove Ra (e.g., Carvalho et al., 2007). In this chapter, we review the hydrometallurgical processes by which U is extracted from ore, the biogeochemical processes that can

  6. Uranium Mill Tailings Remedial Action Project environmental protection implementation plan

    The Uranium Mill Tailings Remedial Action (UMTRA) Project Environmental Protection Implementation Plan (EPIP) has been prepared in accordance with the requirements of the U.S. Department of Energy (DOE) Order 5400.1. The UMTRA EPIP is updated annually. This version covers the time period of 9 November 1994, through 8 November 1995. Its purpose is to provide management direction to ensure that the UMTRA Project is operated and managed in a manner that will protect, maintain, and where necessary, restore environmental quality, minimize potential threats to public health and the environment, and comply with environmental regulations and DOE policies

  7. Uranium Mill Tailings Remedial Action Project. 1995 Environmental Report

    In accordance with U.S. Department of Energy (DOE) Order 23 1. 1, Environment, Safety and Health Reporting, the DOE prepares an annual report to document the activities of the Uranium Mill Tailings Remedial Action (UMTRA) Project environmental monitoring program. This monitoring must comply with appropriate laws, regulations, and standards, and it must identify apparent and meaningful trends in monitoring results. The results of all monitoring activities must be communicated to the public. The UMTRA Project has prepared annual environmental reports to the public since 1989

  8. Uranium mill tailings storage, use, and disposal problems

    Solid and liquid residues (tailings) containing substantial quantities of naturally occurring radionuclides are produced and stored at all US uranium mill sites. These radioactive wastes are a potential health hazard with the degree of hazard depending largely on the tailings management practices at the individual sites. The principal pathways of potential radiation exposure to man are discussed. A description is presented of some past and current tailings storage practices together with a description of some of the possible problems associated with various stabilization and disposal options. 16 figures

  9. Uranium Mill Tailings Remedial Action Project. 1995 Environmental Report

    NONE

    1996-06-01

    In accordance with U.S. Department of Energy (DOE) Order 23 1. 1, Environment, Safety and Health Reporting, the DOE prepares an annual report to document the activities of the Uranium Mill Tailings Remedial Action (UMTRA) Project environmental monitoring program. This monitoring must comply with appropriate laws, regulations, and standards, and it must identify apparent and meaningful trends in monitoring results. The results of all monitoring activities must be communicated to the public. The UMTRA Project has prepared annual environmental reports to the public since 1989.

  10. Uranium Mill Tailings Remedial Action Project 1993 Environmental Report

    This annual report documents the Uranium Mill Tailing Remedial Action (UMTRA) Project environmental monitoring and protection program. The UMTRA Project routinely monitors radiation, radioactive residual materials, and hazardous constituents at associated former uranium tailings processing sites and disposal sites. At the end of 1993, surface remedial action was complete at 10 of the 24 designated UMTRA Project processing sites. In 1993 the UMTRA Project office revised the UMTRA Project Environmental Protection Implementation Plan, as required by the US DOE. Because the UMTRA Project sites are in different stages of remedial action, the breadth of the UMTRA environmental protection program differs from site to site. In general, sites actively undergoing surface remedial action have the most comprehensive environmental programs for sampling media. At sites where surface remedial action is complete and at sites where remedial action has not yet begun, the environmental program consists primarily of surface water and ground water monitoring to support site characterization, baseline risk assessments, or disposal site performance assessments

  11. Application of nanofiltration to the treatment of uranium mill effluents

    Nanofiltration is widely used in water treatment due to the lower energy requirements and higher yields than reverse osmosis. Separation characteristics are dependent on both the molecular size and charge of the dissolved species in the feed solution as well as membrane properties. In this investigation the potential of nanofiltration to remove dissolved species from uranium mill effluent has been studied. The background behind the application is discussed and the results of the first testwork programme are presented. An initial screening of seventeen commercially available membranes was completed and it was found that uranium rejections of greater than 75% were consistently achieved. Selected membranes also showed potential for the separation of radium, sulfate and manganese. (author)

  12. Uptake of uranium by plants growing on and around uranium mill tailings pond at Jaduguda, India

    A field study was conducted in an area where uranium mill tailings are discharged in the form of slurry (mixture of fine sand and effluent). The fine tailings sand is retained there and effluent is decanted for further treatment. Over the years, certain plant species like Typha latifolia, Saccharum spontanium, Ipomoea carnia etc. have covered the major portion of the tailings pond. Concentration and concentration ratio of uranium in different organs of these plants were evaluated. Concentration of uranium in Typha latifolia plant from tailings pond and the CR was found to have inverse relationship with substrate uranium content. Correlation coefficient between CR(R) and soil, CR(St) and soil and CR(L) and soil in Typha latifolia was -0.80, -0.90 and -0.86 respectively. (author)

  13. Completion of the uranium mill tailings remedial project and cleanup of the former mill site at Grand Junction, Colorado

    The United States Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Surface Project has successfully completed the cleanup of 22 former uranium mill sites, more than 5400 vicinity properties, and has constructed 18 entombment cells. The Project has recently received the United States Nuclear Regulatory Commission's approval and certification for the last two disposal sites, with these sites being placed under the general license for long term custodial care of residual radioactive material. The UMTRA site located at Grand Junction, Colorado is a good example of the technical, political, economic, and public relations challenges that were overcome in achieving success. The UMTRA Team discussed, negotiated, planned, and eventually acted on this uranium mill tailings problem and brought the project to a successful conclusion for the community. From the early 1940s through the 1970s, uranium ore was mined in significant quantities under United States federal contracts for the government's national defence programmes, i.e. the Manhattan Engineering District and Atomic Energy Commission programmes. The problem started as the need for uranium decreased in the late 1960s, resulting in mills shutting down, leaving behind large quantities of process waste tailings and contaminated mill buildings. The former Climax Uranium Company mill site in Grand Junction was one of the largest of these sites. (author)

  14. 76 FR 59173 - Standard Format and Content of License Applications for Conventional Uranium Mills

    2011-09-23

    ... COMMISSION Standard Format and Content of License Applications for Conventional Uranium Mills AGENCY: Nuclear Regulatory Commission. ACTION: Draft regulatory guide; withdrawal. SUMMARY: On May 30, 2008 (73 FR 31152... Conventional Uranium Mills.'' DG- 3024 was a proposed Revision 2 of Regulatory Guide (RG) 3.5. However,...

  15. Development of an algorithm for the biogeochemical evolution of uranium mill tailings

    This paper presents an analysis of relevant time scales for modelling the geochemical evolution of uranium mill tailings (seconds to millions of years). It is suggested that the chemical retention time of pore water is an appropriate parameter for assessing the interaction of transport and kinetics in formulating an algorithm for the evolution of uranium mill tailings

  16. Environmental assessment of remedial action at the Lowman Uranium Mill Tailings Site near Lowman, Idaho

    This document assesses the environmental impacts of stabilization on site of the contaminated materials at the Lowman uranium mill tailings site. The Lowman site is 0.5 road mile northeast of the unincorporated village of Lowman, Idaho, and 73 road miles from Boise, Idaho. The Lowman site consists of piles of radioactive sands, an ore storage area, abandoned mill buildings, and windblown/waterborne contaminated areas. A total of 29.5 acres of land are contaminated and most of this land occurs within the 35-acre designated site boundary. The proposed action is to stabilize the tailings and other contaminated materials on the site. A radon barrier would be constructed over the consolidated residual radioactive materials and various erosion control measures would be implemented to ensure the long-term stability of the disposal cell. Radioactive constituents and other hazardous constituents were not detected in the groundwater beneath the Lowman site. The groundwater beneath the disposal cell would not become contaminated during or after remedial action so the maximum concentration limits or background concentrations for the contaminants listed in the draft EPA groundwater protection standards would be met at the point of compliance. No significant impacts were identified as a result of the proposed remedial action at the Lowman site

  17. Environmental assessment of remedial action at the Lowman Uranium Mill Tailings Site near Lowman, Idaho. Final

    1991-01-01

    This document assesses the environmental impacts of stabilization on site of the contaminated materials at the Lowman uranium mill tailings site. The Lowman site is 0.5 road mile northeast of the unincorporated village of Lowman, Idaho, and 73 road miles from Boise, Idaho. The Lowman site consists of piles of radioactive sands, an ore storage area, abandoned mill buildings, and windblown/waterborne contaminated areas. A total of 29.5 acres of land are contaminated and most of this land occurs within the 35-acre designated site boundary. The proposed action is to stabilize the tailings and other contaminated materials on the site. A radon barrier would be constructed over the consolidated residual radioactive materials and various erosion control measures would be implemented to ensure the long-term stability of the disposal cell. Radioactive constituents and other hazardous constituents were not detected in the groundwater beneath the Lowman site. The groundwater beneath the disposal cell would not become contaminated during or after remedial action so the maximum concentration limits or background concentrations for the contaminants listed in the draft EPA groundwater protection standards would be met at the point of compliance. No significant impacts were identified as a result of the proposed remedial action at the Lowman site.

  18. Uranium milling: Volume 1, Summary and text: Generic environmental impact statement: Draft

    This generic environmental impact statement on uranium milling has been prepared in accordance with a notice of intent published by the Nuclear Regulatory Commission (NRC). The purpose of the statement is to assess the potential environmental impacts of uranium milling operations, in a programmatic context, including the management of uranium mill tailings, and to provide an opportunity for public participation in decisions on any proposed changes in NRC regulations based on this assessment. The principal objectives of the statement are to assess the nature and extent of the environmental impacts of uranium milling in the United states from local, regional, and national perspectives on both short- and long-term bases, to determine what regulatory actions are needed; to provide information on which to determine what regulatory requirements for management and disposal of mill tailings and mill decommissioning should be; and to support any rule makings that may be determined to be necessary. 39 figs., 130 tabs

  19. Uranium mill tailings neutralization: contaminant complexation and tailings leaching studies

    Laboratory experiments were performed to compare the effectiveness of limestone (CaCO3) 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

  20. Liner evaluation for uranium mill tailings. Final report

    Buelt, J.L. (comp.)

    1983-09-01

    The Liner Evaluation for Uranium Mill Tailings Program was conducted to evaluate the need for and performance of prospective lining materials for the long-term management of inactive uranium mill tailings piles. On the basis of program results, two materials have been identified: natural foundation soil amended with 10% sodium bentonite; catalytic airblown asphalt membrane. The study showed that, for most situations, calcareous soils typical of Western US sites adequately buffer tailings leachates and prevent groundwater contamination without additional liner materials or amendments. Although mathematical modeling of disposal sites is recommended on a site-specific basis, there appears to be no reason to expect significant infiltration through the cover for most Western sites. The major water source through the tailings would be groundwater movement at sites with shallow groundwater tables. Even so column leaching studies showed that contaminant source terms were reduced to near maximum contaminant levels (MCL's) for drinking water within one or two pore volumes; thus, a limited source term for groundwater contamination exists. At sites where significant groundwater movement or infiltration is expected and the tailings leachates are alkaline, however, the sodium bentonite or asphalt membrane may be necessary.

  1. Measurement and calculation of radon releases from uranium mill tailings

    The mining and milling of uranium ores produces large quantities of radioactive wastes. Although relatively small in magnitude compared to tailings from metal mining and extraction processes, the present worldwide production of such tailings exceeds 20 million tonnes annually. There is thus a need to ensure that the environmental and health risks from these materials are reduced to an acceptable level. This report has been written as a complement to another publication entitled Current Practices for the Management and Confinement of Uranium Mill Tailings, IAEA Technical Reports Series No. 335, which provides a general overview of all the important factors in the siting, design and construction of tailings impoundments, and in the overall management of tailings with due consideration give to questions of the release of pollutants from tailings piles. The present report provides a comprehensive overview of the release, control and monitoring of radon, including computational methods. The report was first drafted in 1989 and was then reviewed at an Advisory Group meeting in 1990. 42 refs, 9 figs, 3 tabs

  2. Radon attenuation handbook for uranium mill tailings cover design

    This handbook has been prepared to facilitate the design of earthen covers to control radon emission from uranium mill tailings. Radon emissions from bare and covered uranium mill tailings can be estimated from equations based on diffusion theory. Basic equations are presented for calculating surface radon fluxes from covered tailings, or alternately, the cover thicknesses required to satisfy a given radon flux criterion. Also described is a computer code, RAECOM, for calculating cover thicknesses and surface fluxes. Methods are also described for measuring diffusion coefficients for radon, or for estimating them from empirical correlations. Since long-term soil moisture content is a critical parameter in determining the value of the diffusion coefficient, methods are given for estimating the long-term moisture contents of soils. The effects of cover defects or advection are also discussed and guidelines are given for determining if they are significant. For most practical cases, advection and cover defect effects on radon flux can be neglected. Several examples are given to demonstrate cover design calculations, and an extensive list of references is included. 63 references, 18 figures, 6 tables

  3. Denitrification in groundwater at uranium mill tailings sites

    Nitrates are a major contaminant in groundwater at many Uranium Mill Tailings Remedial Action (UMTRA) sites. Microbial denitrification, the transformation of nitrate to nitrogen gas, may be occurring in groundwater at several UMTRA sites. Denitrification is a biologically mediated process whereby facultative anaerobes use nitrate for respiration under anaerobic conditions. Denitrifying bacteria are ubiquitous in soils, sediments, and water. Denitrification requires nitrate, organic carbon, oxygen-limiting conditions, and trace nutrients, especially phosphorus. The lack of organic carbon is the most common limiting factor for denitrification. Denitrification occurs under a limited range of temperature and pH. The uranium milling processes used at UMTRA sites provided a readily available source of carbon and nitrates for denitrifying bacteria. At the Maybell, Colorado, site, the denitrifying organisms Pseudomonas, Flavobacterium and Acinetobacter were identified in core samples of materials from beneath the tailings. In addition, microcosm experiments simulating aquifer conditions beneath the tailings pile showed an average 40 percent decrease in nitrate concentrations over 13 days. At the New Rifle, Colorado, site, aquifer conditions appear favorable for denitrification. Nitrate and organic carbon are readily available in the groundwater, and redox conditions beneath and downgradient of the tailings pile are relatively anoxic. Downgradient from the tailings, total nitrogen is being removed from the groundwater system at a greater rate than the geochemically conservative anion, chloride. This removal may be due to denitrification and adsorption of ammonium onto clay and silt particles. (author)

  4. Liner evaluation for uranium mill tailings. Final report

    The Liner Evaluation for Uranium Mill Tailings Program was conducted to evaluate the need for and performance of prospective lining materials for the long-term management of inactive uranium mill tailings piles. On the basis of program results, two materials have been identified: natural foundation soil amended with 10% sodium bentonite; catalytic airblown asphalt membrane. The study showed that, for most situations, calcareous soils typical of Western US sites adequately buffer tailings leachates and prevent groundwater contamination without additional liner materials or amendments. Although mathematical modeling of disposal sites is recommended on a site-specific basis, there appears to be no reason to expect significant infiltration through the cover for most Western sites. The major water source through the tailings would be groundwater movement at sites with shallow groundwater tables. Even so column leaching studies showed that contaminant source terms were reduced to near maximum contaminant levels (MCL's) for drinking water within one or two pore volumes; thus, a limited source term for groundwater contamination exists. At sites where significant groundwater movement or infiltration is expected and the tailings leachates are alkaline, however, the sodium bentonite or asphalt membrane may be necessary

  5. Uranium Mill Tailings Remedial Action Project, Surface Project Management Plan. Revision 1

    Title I of the Uranium Mill Tailings Radiation Control Act (UMTRCA) authorizes the US Department of Energy (DOE) to undertake remedial action at 24 designated inactive uranium processing sites and associated vicinity properties (VP) containing uranium mill tailings and related residual radioactive materials. The purpose of the Uranium Mill Tailings Remedial Action (UMTRA) Surface Project is to minimize or eliminate radiation health hazards to the public and the environment at the 24 sites and related VPs. This document describes the management organization, system, and methods used to manage the design, construction, and other activities required to clean up the designated sites and associated VPs, in accordance with the UMTRCA

  6. Ground water contamination from an inactive uranium mill tailings pile. I. Application of a chemical mixing model

    Low-pH process waters contained in a number of inactive and abandoned uranium mill tailings in the US represent potential sources of radionuclide and trace metal contamination of ground water. Detailed investigations at a typical site at Riverton, Wyoming, indicate that chemical transport occurs from initial dewatering of the tailings, downward infiltration due to precipitation, and ground water intrusion into the base of the tailings pile. Except for elevated uranium and molybdenum concentrations, current radionuclide and trace metal transport is limited by near neutral pH conditions of the ground water. Significant reactions include the dissolution of calcite, production of CO2, and precipitation of gypsum and the hydroxides of iron and aluminum. A geochemical mixing model employing the PHREEQE computer code is used to estimate current rates of the ground water contamination by tailings water. A maximum mixing of 1.7% of pore water is a factor of 2 less than steady state estimates based on hydraulic parameters

  7. Effects of column dimensions on uranium mill tailings leach curves

    Experiments were conducted using different sized columns filled with uranium mill tailings and leached with laboratory-prepared groundwater. The data generated were used to evaluate the effects of length-to-diameter ratios on leach curves. These different column sizes and flow rates provided: different solution/solid contact times, and different column volumes (scaling) and thus allowed us to address the question, Can laboratory results be scaled up to apply to real world disposal conditions. The results showed that the leach curves were similar for all the columns for all elements except chloride and calcium. The general shape of the leach curves for each constituent versus effluent volume was a rapidly decreasing curve from very high concentrations down to the groundwater concentration within about four to six pore volumes. Chloride elution was affected by mechanical dispersion, causing effluent concentrations to reach influent concentrations sooner for the columns with longer residence times. The calcium concentrations remained nearly constant or only slightly decreased over the duration of the experiments and were assumed to be controlled by the dissolution of gypsum. Aside from the chloride data, over the range of residence times and scaling factors studied, we conclude that laboratory data on uranium mill tailings leaching can be used to predict long-term movement of contaminants from actual tailings impoundments. The main reactions tha control contaminant leaching from tailings are the displacement of residual mill process liquor and the redissolution of readily soluble evaporites and moderately soluble gypsum. These processes occur quite rapidly and therefore laboratory experiments with relatively short residence times are still accurate; i.e., lab residence times are long enough to transcend any short-term kinetic effects that could lead to erroneous predictions. 8 references, 6 figures, 3 tables

  8. Geochemical behavior of uranium mill tailings leachate in the subsurface

    Leachate generated from surface disposal of acidic uranium mill tailings at Maybell, CO has impacted groundwater quality within the underlying mineralized Browns Park Formation. The extent of groundwater contamination, however, is located directly beneath the tailings impoundment. The milling process consisted of sulfuric acid extraction of uranium from the feed ore by a complex chemical leaching and precipitation process. Tailings leachate at the site contains elevated concentrations of Al, As, Cd, Mo, Ni, NO3, Se, U, and other solutes. From column leach tests, the concentrations of contaminants within tailings pore fluid are SO4>NH4>NO3>U>Se>Ni>As>Cd at pH 4.0. The carbonate buffering capacity of the tailings subsoil has decreased because of calcite dissolution in the presence of acidic leachate. Groundwater quality data, mineralogical and microbiological studies, and geochemical modeling suggest that As, NO3, Se, U and other solutes are being removed from solution through precipitation, adsorption, and denitrification processes under reducing conditions. Presence of hydrogen sulfide, liquid and gaseous hydrocarbons, dissolved organic, and abundant pyrite within the Browns Park Formations have maintained reducing conditions subjacent to the tailings impoundment. Groundwater is in close equilibrium with coffinite and uraninite, the primary U(IV) minerals extracted from the Browns Parks Formation. Denitrifying bacteria identified in this study catalyze redox reactions involving NO3. Subsequently, contaminant distributions of NO3 decrease 1000 times beneath the tailings impoundment. Applying geochemical and biochemical processes occurring at Maybell provides an excellent model for in situ aquifer restoration programs considered at other uranium tailings and heavy-metal-mixed waste contaminated sites. (author) 4 figs., 4 tabs., 27 refs

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

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

  10. Systematic evaluation of satellite remote sensing for identifying uranium mines and mills

    In this report, we systematically evaluate the ability of current-generation, satellite-based spectroscopic sensors to distinguish uranium mines and mills from other mineral mining and milling operations. We perform this systematic evaluation by (1) outlining the remote, spectroscopic signal generation process, (2) documenting the capabilities of current commercial satellite systems, (3) systematically comparing the uranium mining and milling process to other mineral mining and milling operations, and (4) identifying the most promising observables associated with uranium mining and milling that can be identified using satellite remote sensing. The Ranger uranium mine and mill in Australia serves as a case study where we apply and test the techniques developed in this systematic analysis. Based on literature research of mineral mining and milling practices, we develop a decision tree which utilizes the information contained in one or more observables to determine whether uranium is possibly being mined and/or milled at a given site. Promising observables associated with uranium mining and milling at the Ranger site included in the decision tree are uranium ore, sulfur, the uranium pregnant leach liquor, ammonia, and uranyl compounds and sulfate ion disposed of in the tailings pond. Based on the size, concentration, and spectral characteristics of these promising observables, we then determine whether these observables can be identified using current commercial satellite systems, namely Hyperion, ASTER, and Quickbird. We conclude that the only promising observables at Ranger that can be uniquely identified using a current commercial satellite system (notably Hyperion) are magnesium chlorite in the open pit mine and the sulfur stockpile. Based on the identified magnesium chlorite and sulfur observables, the decision tree narrows the possible mineral candidates at Ranger to uranium, copper, zinc, manganese, vanadium, the rare earths, and phosphorus, all of which are

  11. Systematic evaluation of satellite remote sensing for identifying uranium mines and mills.

    Blair, Dianna Sue; Stork, Christopher Lyle; Smartt, Heidi Anne; Smith, Jody Lynn

    2006-01-01

    In this report, we systematically evaluate the ability of current-generation, satellite-based spectroscopic sensors to distinguish uranium mines and mills from other mineral mining and milling operations. We perform this systematic evaluation by (1) outlining the remote, spectroscopic signal generation process, (2) documenting the capabilities of current commercial satellite systems, (3) systematically comparing the uranium mining and milling process to other mineral mining and milling operations, and (4) identifying the most promising observables associated with uranium mining and milling that can be identified using satellite remote sensing. The Ranger uranium mine and mill in Australia serves as a case study where we apply and test the techniques developed in this systematic analysis. Based on literature research of mineral mining and milling practices, we develop a decision tree which utilizes the information contained in one or more observables to determine whether uranium is possibly being mined and/or milled at a given site. Promising observables associated with uranium mining and milling at the Ranger site included in the decision tree are uranium ore, sulfur, the uranium pregnant leach liquor, ammonia, and uranyl compounds and sulfate ion disposed of in the tailings pond. Based on the size, concentration, and spectral characteristics of these promising observables, we then determine whether these observables can be identified using current commercial satellite systems, namely Hyperion, ASTER, and Quickbird. We conclude that the only promising observables at Ranger that can be uniquely identified using a current commercial satellite system (notably Hyperion) are magnesium chlorite in the open pit mine and the sulfur stockpile. Based on the identified magnesium chlorite and sulfur observables, the decision tree narrows the possible mineral candidates at Ranger to uranium, copper, zinc, manganese, vanadium, the rare earths, and phosphorus, all of which are

  12. Uranium mining and milling sites in Argentina: environmental radiological monitoring (1981-1994)

    Environmental radiological monitoring in the vicinity of Argentinean uranium mining and milling plants is performed on a routine basis, in order to assess the possibility of a significant environmental contamination due to uranium mill wastes or by mill tailings for the plants still operating or by those plants where the exploitation was concluded. Dissolved 226Ra and natural uranium concentrations in surface water are measured in samples taken at selected points upstream and downstream from rivers, in the area of influence of the mills. In the present paper the environmental radiological monitoring program results obtained for the 1981-1994 period are shown, and from the analysis of these data it can be concluded that no remarkable exposure occurs for the population living in the vicinity of the analyzed areas due to the uranium mining and milling plants operation or their wastes. (author)

  13. Uranium Mill Tailings Remedial Action Project Environmental Protection Implementation Plan

    The Uranium Mill Tailings Remedial Action (UMTRA) Project Environmental Protection Implementation Plan (EPIP) has been prepared in accordance with the requirements of the US Department of Energy (DOE) Order 5400.1. The UMTRA EPIP covers the time period of November 9, 1993, through November 8, 1994. It will be updated annually. Its purpose is to provide management direction to ensure that the UMTRA Project is operated and managed in a manner that will protect, maintain, and where necessary, restore environmental quality, minimize potential threats to public health and the environment, and comply with environmental regulations and DOE policies. Contents of this report are: (1) general description of the UMTRA project environmental protection program; (2) notifications; (3) planning and reporting; (4) special programs; (5) environmental monitoring programs; (6) quality assurance and data verification; and (7) references

  14. Health and safety regulation of uranium mining and milling

    The Canadian Atomic Energy Control Board licenses all nuclear facilities in Canada, including uranium mines and mills. The protection of health, safety and the environment is one of the requirements of each licence. A limit of 4 Working Level Months exposure to radon and radon daughters annually has been set, and guidelines for weekly or more frequent workplace monitoring have been established. Personal monitoring devices are being tested, and thermoluminescent dosimeters are to be introduced. The Board reviews its licensees' ventilation plans continuously. The staged licensing process involves the granting of the following documents: 1) ore removal; 2) underground exploration permit; 3) site and construction approval; 4) mining facility operating licence; 5) shut-down approval. Compliance with regulations and licence conditions is monitored mainly by inspectors appointed by provincial agencies, with Board staff exercising auditing fuctions. The Board involves the workers directly with their own health and safety by sending their unions copies of all relevant documents and inviting comments

  15. Environmental management audit, Uranium Mill Tailings Remedial Action Project (UMTRA)

    The Office of Environment, Safety and Health (EH) has established, as part of the internal oversight responsibilities within Department of Energy (DOE), a program within the Office of Environmental Audit (EH-24), to conduct environmental audits at DOE's operating facilities. This document contains the results of the Environmental Management Audit of the Uranium Mill Tailings Remedial Action (UMTRA) Project. This Environmental Management Audit was conducted by the DOE's Office of Environmental Audit from October 26 through November 6, 1992. The audit's objective is to advise the Secretary as to the adequacy of UMTRA's environmental programs, and management organization in ensuring environmental protection and compliance with Federal, state, and DOE environmental requirements. This Environmental Management Audit's scope was comprehensive and covered all areas of environmental management with the exception of environmental programs pertaining to the implementation of the requirements of the National Environmental Policy Act (NEPA), which is the responsibility of the DOE Headquarters Office of NEPA Oversight

  16. Economic evaluation of remanded clean airact standards for uranium mill tailings piles

    In 1986 the Environmental Protection Agency (EPA), under authority of the Clean Air Act (CAA), established standards for controlling radon emissions from uranium mill tailings piles. As a result of a court decision on a related standard, EPA voluntarily remanded all of its CAA Standards for radionuclides in December 1987, including the 1986 Standards for Uranium Mill Tailings. EPA currently plans to promulgate final CAA Standards for uranium mill tailings piles. Three separate standards are under consideration. The costs and benefits associated with these options are discussed

  17. Uranium Mill Tailings Remedial Action Project 1994 environmental report

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

  18. Environmental protection of uranium mines and mills in India: regulator's perspective

    Uranium mining and milling involves mining of the uranium ore from underground or open cast mine and chemically processing of the mined out ore to recover the uranium values. The storage of excavated waste rock, the disposal of radium containing mine water to water bodies, the venting out of radon containing mine exhaust to the open atmosphere constitute the environmental radiological hazards from a uranium mine. After chemical processing of the ore in a mill, the bulk of the radioactivity originally present in the ore along with the added chemicals finds its way in the mill tailings. Therefore, it warrants adequate safety measures for protection of the environment from the adverse effects of chemicals and radioactivity. These safety aspects of the uranium mines and mills and the impact on the environment are reviewed by the Atomic Energy Regulatory Board (AERB), the national regulatory body of India. This paper discusses the regulatory framework, regulatory issues associated with uranium mines and mills and the safety stipulations laid down during the consenting process of the new projects so that the environment around uranium mine and mill is adequately protected. (author)

  19. Uptake of uranium by aquatic plants growing in fresh water ecosystem around uranium mill tailings pond at Jaduguda, India.

    Jha, V N; Tripathi, R M; Sethy, N K; Sahoo, S K

    2016-01-01

    Concentration of uranium was determined in aquatic plants and substrate (sediment or water) of fresh water ecosystem on and around uranium mill tailings pond at Jaduguda, India. Aquatic plant/substrate concentration ratios (CRs) of uranium were estimated for different sites on and around the uranium mill tailings disposal area. These sites include upstream and downstream side of surface water sources carrying the treated tailings effluent, a small pond inside tailings disposal area and residual water of this area. Three types of plant groups were investigated namely algae (filamentous and non-filamentous), other free floating & water submerged and sediment rooted plants. Wide variability in concentration ratio was observed for different groups of plants studied. The filamentous algae uranium concentration was significantly correlated with that of water (r=0.86, p<0.003). For sediment rooted plants significant correlation was found between uranium concentration in plant and the substrate (r=0.88, p<0.001). Both for other free floating species and sediment rooted plants, uranium concentration was significantly correlated with Mn, Fe, and Ni concentration of plants (p<0.01). Filamentous algae, Jussiaea and Pistia owing to their high bioproductivity, biomass, uranium accumulation and concentration ratio can be useful for prospecting phytoremediation of stream carrying treated or untreated uranium mill tailings effluent. PMID:26360459

  20. Water and materials balances of a spoil bank of an abandoned uranium mine in the Freital district, Sachsen

    Sanitation of former uranium mines started immediately after uranium mining in East Germany was abandoned in 1990. In the case of shaft 1 of the Dresden-Gittersee mine, a multilayer mineral sealing system was decided. As required by the radiation protection authorities, the Wismut GmbH initiated a detailed hydrogeological expert's opinion including a forecast of the long-term effects of sealing on the basis of hydrogeological data and a material flow analysis for the spoil bank

  1. Water quality and hydrologic impacts of disposal of uranium mill tailings by backfilling

    Backfilling of the sand portion of spent uranium mill tailings has been practised for years in the Grants Mineral Belt of New Mexico, USA. Until recently, it has been limited to abandoned stopes requiring roof support to enable continued ore production. Recent environmental regulations of surface disposal make backfilling an increasingly attractive alternative for disposal of a greater fraction of the tails. This paper discusses the impacts of the backfill process on groundwater resources. Immediate and long-term hydrologic effects are evaluated. Whereas backfilling does lead to some changes in minewater flows, these changes are localized, of slight magnitude, and of short duration. In the long term, backfilling will have inconsequential impact on regional hydrology. Short- and long-term water quality impacts are considered. In general, backfill decant is contaminated with the same constituents found in normal mine wastewater, but at elevated concentrations. During the backfill process, backfill decant is returned to the surface and treated along with dewatering discharge. In the longer term, there may exist some potential for contaminants mobilized from backfill media in a flooded mine to migrate into the surrounding aquifer. It is predicted that low groundwater velocities and geochemical interactions including precipitation will together prevent any backfill-caused deterioration of regional groundwater quality. (author)

  2. Disposal technique inspect of France's uranium mine and mill facilities decommissioning

    Invited by Linet F.L., the director of France Atomic Energy Committee, China disposal technique inspection delegation on uranium mine and mill facilities decommissioning (UMMFD) inspected France's UMMFD disposal techniques on Oct. 7∼30, 1997. Introduces in detail the disposal Standard, environmental radiation monitoring and evaluation, covering experiment and decommissioning disposal procedure, and gives certain case of France's uranium mine and mill facilities decommissioning disposal

  3. Studies on the treatment of uranium mill effluents

    Overflow waters from the tailings pond in which liquid effluents in the form of barren liquors from uranium mill are discharged may contain 10 pci/litre of radium activity as against the maximum permissible discharge limit of 3 pci/litre and 10 mg/litre of soluble manganese as against the allowable limit of 0.3 mg/litre. These contaminants must be removed and/or made insoluble to ensure environmental safety. Studies were, therefore, carried out to develop methods for: (1) decontamination of both barren liquors and overflow waters and (2) their insolubilisation prior to their release in the pond. Based on the results, a scheme of treatment is formulated. Radium activity in the barren liquor is insolubilised by addition of 25 mg Ba2+/litre and precipitation. The liquor is then neutralised with lime. The sludges on liquid-solid separation are subjected to air digestion to stabilise manganese(II) to highly insoluble manganese(IV) oxide. Supernatant and the digested sludges are discharged to the tailings pond. Overflow waters from the pond are treated with 5 to 10 mgs/litre of permanganate to remove manganese and radium. The precipitates resulting in the process may be disposed as solid radioactive wastes and decontaminated water may be released to the environment or if it meets the mill specification, may be reused as process water thus ruling out even the slightest possibility of environmental pollution. The overall cost of chemicals required for the treatment mentioned above works out to be Rs. 0.30 per cubic metre of effluent. (M.G.B.)

  4. Annual status report on the Uranium Mill Tailings Remedial Action Program

    This fourteenth annual status report for the Uranium Mill Tailings Remedial Action (UMTRA) Project Office summarizes activities of the Uranium Mill Tailings Remedial Action Surface (UMTRA-Surface) and Uranium Mill Tailings Remedial Action Groundwater (UMTRA-Groundwater) Projects undertaken during fiscal year (FY) 1992 by the US Department of Energy (DOE) and other agencies. Project goals for FY 1993 are also presented. An annual report of this type was a statutory requirement through January 1, 1986, pursuant to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law (PL) 95-604. The DOE will continue to submit annual reports to DOE-Headquarters, the states, tribes, and local representatives through Project completion in order to inform the public of the yearly Project status. The purpose of the remedial action is to stabilize and control the tailings and other residual radioactive material (RRM) located on the inactive uranium processing sites in a safe and environmentally sound manner, and to minimize or eliminate potential health hazards. Commercial and residential properties near designated processing sites that are contaminated with material from the sites, herein referred to as ''vicinity properties (VP),'' are also eligible for remedial action. Included in the UMTRA Project are 24 inactive uranium processing sites and associated VPs located in 10 states, and the VPs associated with the Edgemont, South Dakota, uranium mill currently owned by the Tennessee Valley Authority (TVA) (Figure A.1, Appendix A)

  5. 226Ra bioavailability of plants at urgeirica uranium mill tailings

    Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeirica mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides, some shrubs (Cytisus s.p.) are growing at some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings through the quantification of the total and available fraction of radium in the solid wastes and to estimate its transfer to the plants growing on the tailing piles. Plants and solid waste samples were randomly collected at dams. Activity concentration of 226Ra in plants (aerial part and roots) and solid wastes were measured by gamma spectrometry. The exchangeable fraction of radium in solid wastes was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH=7) or 1 mol dm-3 calcium chloride solutions. The results obtained for the 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentration in the solid wastes and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0±8.3 and 12.9±8.9, for the fraction of radium extracted from the solid wastes, using 1 mol dm-3 ammonium acetate or calcium chloride solutions respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, within the standard error values, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. (author)

  6. Immobilization of radium in uranium mine and mill tailings

    Radium has been coprecipitated from solution as the arsenate in which ferric iron, barium, copper and lead are the macro ions. The order of efficiency of the macro ions in removing radium was found to be Ba > Fe > Pb > Cu at a pH of 6. It is expected that at higher pH's i.e., greater than 8, ferric iron will change positions. This change in position will be caused by the formation of ferrate ion hence increasing the solubility of ferric arsenate. The removal of radium from solution by ion exchangers consisting of the arsenates of ferric iron, barium, copper and lead was successful. As the pH is increased from 4 to 10 the efficiency of these exchangers in removing radium increases. The columns removed over 99 percent of the radium at pH's of 5.6 and higher. The order of efficiency of the exchangers in removing radium is not well defined. Thorium has been precipitated as the arsenate over the pH range of 2 to 9.6. This reaction suggests the possibility of using arsenate to remove thorium from uranium mill plant streams and as a reagent to keep thorium in the tailings ponds

  7. Geotechnical behavior of uranium mill tailings from Saskatchewan, Canada

    Bhuiyan Imteaz; Azam Shahid; Khaled Shifullah; Landine Patrick

    2016-01-01

    This paper investigates the geotechnical behavior of uranium mill tailings from Saskatchewan, Canada. The 4% tailings were well-graded with 29% fines whereas the 5% and 6% tailings were gap-graded with 49% fines. All samples exhibited a negligible strength (0.4 kPa) up to 60% solids, followed by a rapid increase. The 4% tailings exhibited a lower rate and amount of settlement than 5% and 6% tail-ings. The ki decreased from 10-2 to 10-4 m/s with a decrease in ei from 16 to 4 and a decrease in ef from 8 to 4 such that 4% tailings showed one order of magnitude lower values than the 5% and 6%tailings. The settling potential decreased ten times (50%–5%) for 4% tailings and four times (60%–15%) for 5% and 6% tailings. The effective stress increased from 80 to 260 Pa in the settling tests. The 4%tailings were less prone to segregation when compared with 5% and 6% tailings. The average solids content after settling was 35% for 4% tailings, 40% for 5% tailings and 39% for 6% tailings with a solids content deviation of ±3%, ±8%, ±6%, respectively. All materials were essentially non-segregating at 40%initial solids.

  8. Safeguards on uranium ore concentrate? the impact of modern mining and milling process

    Increased purity in uranium ore concentrate not only raises the question as to whether Safeguards should be applied to the entirety of uranium conversion facilities, but also as to whether some degree of coverage should be moved back to uranium ore concentrate production at uranium mining and milling facilities. This paper looks at uranium ore concentrate production across the globe and explores the extent to which increased purity is evident and the underlying reasons. Potential issues this increase in purity raises for IAEA's strategy on the Starting Point of Safeguards are also discussed

  9. Environmental Assessment of Remedial Action at the Mexican Hat Uranium Mill Tailings Site, Mexican Hat, Utah

    U.S. Department of Energy

    1987-01-01

    This document assesses the environmental impacts of the proposed remedial action at the Mexican Hat uranium mill tailings site located on the Navajo Reservation in southern Utah. The site covers 235 acres and contains 69 acres of tailings and several of the original mill structures. The Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law 95-604 (PL95-604), authorized the U.S. Department of Energy to clean up the site to reduce the potential health impacts associated wit...

  10. Remedial action plan and site design for stabilization of the inactive uranium mill tailings site at Tuba City, Arizona: Phase 2, Construction, Subcontract documents: Appendix E, final report. [Uranium Mill Tailings Remedial Action (UMTRA) Project

    1989-08-01

    This appendix discusses Phase II construction and subcontract documents uranium mill site near Tuba City, Arizona. It contains the bid schedule, special conditions, specifications, and subcontract drawings.

  11. Rehabilitation proposal for the abandoned uranium mine at Rum Jungle Creek South

    The abandoned uranium mine Rum Jungle Creek South was not rehabilitated after the Rum Jungle uranium project ceased operation in 1971. The mine area is characterised by high external gamma-ray levels, radioactive dust concentrations and radon daughters levels in the air. This implies that annual doses of some individuals are about 5mSv which is the present Australian public limit. The present annual collective dose equivalent to members of the public visiting the area was evaluated about 0.42 man Sv, and the 100 years collective dose commitment is calculated to be about 260 man Sv. Since the new Australian public limit is going to be 1mSv/y, for exposures extending over many years, more members of the public will be exposed above the limit in the future. Four rehabilitation options ranged from a general clean-up burial and stabilisation to full rehabilitation and revegetation have been considered. The ALARA/cost benefit analysis was used to find the optimum rehabilitation option which has an associated cost of A$2.13 million. The present collective dose commitment is going to be reduced by a factor of 7 provided the rehabilitation takes place. There also will be no likelyhood that individuals will be exposed above the new public limit of 1mSv/y in the future

  12. Radium and heavy metal transport beneath an abandoned uranium tailings dam

    An abandoned uranium tailings dam at Moline in the Northern Territory of Australia was the site of a study to assess the movement of potentially toxic elements from tailings into subsoil. The tailings at Moline were first laid down in 1959 and have since been leached by prevailing rainfall. Sixteen sampling sites were selected to give a good representation of the dam. At each site, a trench was excavated through the tailings and into the subsoil, then samples of subsoil were taken at 10 cm intervals down to a depth of 50 cm. A sample of the tailings overlying the tailings-subsoil interface was also taken. Samples were analysed for radium, uranium, copper, zinc, and lead. At most sites there was only minor accumulation of these elements in the 0-10 cm subsoil layer immediately below the interface, with concentrations typically one or two orders of magnitude less than the concentrations in overlying tailings. Below 10 cm, the concentrations were typically at or close to background concentrations

  13. Process of the decommission of uranium mines and mills in Germany

    The decommission of uranium mines and mills in Germany began in 1991 and will cost DM 13 billion and spend 20-25 years. The remediation effects have received favorable recognition at the national and international level. The author introduces the technologies and process of the decommission of uranium mines and mills in Germany, including closure of underground mines, remediation of waste rock piles, dismantling and demolition of installations and buildings, stabilization of tailings ponds and water treatment, in addition, briefly presents the development history of uranium mining and metallurgy, the basic legal framework applied to the implementation of remedial measures and decommission monitoring in Germany

  14. The migration of ground-water contaminants from uranium mill tailings piles

    Milling of uranium ore by acid or alkaline leaching methods produces high solution concentrations of both radioactive and nonradioactive species in the mill tailings piles. Seepage of solution from these tailing piles may contaminate local ground-water supplies. As part of the DOE-sponsored Uranium Mill Tailings Remedial Action Project, the movement of contaminants from the tailing piles at inactive mill tailings sites is being characterized. Study to date has shown that many of the potential contaminants, including radium and thorium, are reduced to very low solution levels as a result of water/rock interactions. However, uranium, sulfate, and nitrate have been found at contaminant levels in the ground water at several sites. Spatial distributions of contaminant concentration are used to estimate values of dispersivity and distribution coefficients by calibrating contaminant transport models to site-specific hydrologic conditions. This paper describes the existing contamination at representative sites and discusses the physical and geochemical processes that affect contaminant migration

  15. 238U, and its decay products, in grasses from an abandoned uranium mine

    Childs, Edgar; Maskall, John; Millward, Geoffrey

    2016-04-01

    Bioaccumulation of radioactive contaminants by plants is of concern particularly where the sward is an essential part of the diet of ruminants. The abandoned South Terras uranium mine, south west England, had primary deposits of uraninite (UO2) and pitchblende (U3O8), which contained up to 30% uranium. When the mine was active uranium and radium were extracted but following closure it was abandoned without remediation. Waste rock and gangue, consisting of inefficiently processed minerals, were spread around the site, including a field where ruminants are grazed. Here we report the activity concentrations of 238U, 235U 214,210Pb, and the concentrations of selected metals in the soils, roots and leaves of grasses taken from the contaminated field. Soil samples were collected at the surface, and at 30 cm depth, using an auger along a 10-point transect in the field from the foot of a waste heap. Whole, individual grass plants were removed with a spade, ensuring that their roots were intact. The soils and roots and grass leaves were freeze-dried. Activity concentrations of the radionuclides were determined by gamma spectroscopy, following 30 days incubation for development of secular equilibrium. Dried soils, roots and grasses were also digested in aqua regia and the concentrations of elements determined by ICP techniques. Maximum activity concentrations of 238U, 235U, 214Pb and 210Pb surface soils were 63,300, 4,510, 23,300 and 49,400 Bq kg‑1, respectively. The mean 238U:235U ratio was 11.8 ± 1.8, an order of magnitude lower than the natural value of 138, indicating disequilibrium within the decay chain due to mineral processing. Radionuclides in the roots had 5 times lower concentration and only grass leaves in the vicinity of the waste heap had measureable values. The mean soil to root transfer factor for 238U was 36%, the mean root to leaf was 3% and overall only 0.7% of 238U was transferred from the soil to the leaves. The roots contained 0.8% iron, possibly as

  16. Integrated assessmet of the impacts associated with uranium mining and milling

    The occupational health and safety impacts are assessed for domestic underground mining, open pit mining, and milling. Public health impacts are calculated for a population of 53,000 located within 88 km (55 miles) of a typical southwestern uranium mill. The collective annual dose would be 6.5 man-lung rem/year, 89% of which is from 222Rn emitted from mill tailings. The dose to the United States population is estimated to be 6 x 104 man-lung rem from combined mining and milling operations. This may be comparedd with 5.7 x 105 man-lung rem from domestic use of natural gas and 4.4 x 107 man-lung rem from building interiors. Unavoidable adverse environmental impacts appear to be severe in a 250 ha area surrounding a mill site but negligible in the entire potentially impacted area (500,000 ha). The contemporary uranium resource and supply industry and its institutional settings are described in relation to the socio-economic impacts likely to emerge from high levels of uranium mining and milling. Radon and radon daughter monitoring techniques associated with uranium mining and milling are discussed

  17. Integrated assessmet of the impacts associated with uranium mining and milling

    Parzyck, D.C.; Baes, C.F. III; Berry, L.G.

    1979-07-01

    The occupational health and safety impacts are assessed for domestic underground mining, open pit mining, and milling. Public health impacts are calculated for a population of 53,000 located within 88 km (55 miles) of a typical southwestern uranium mill. The collective annual dose would be 6.5 man-lung rem/year, 89% of which is from /sup 222/Rn emitted from mill tailings. The dose to the United States population is estimated to be 6 x 10/sup 4/ man-lung rem from combined mining and milling operations. This may be comparedd with 5.7 x 10/sup 5/ man-lung rem from domestic use of natural gas and 4.4 x 10/sup 7/ man-lung rem from building interiors. Unavoidable adverse environmental impacts appear to be severe in a 250 ha area surrounding a mill site but negligible in the entire potentially impacted area (500,000 ha). The contemporary uranium resource and supply industry and its institutional settings are described in relation to the socio-economic impacts likely to emerge from high levels of uranium mining and milling. Radon and radon daughter monitoring techniques associated with uranium mining and milling are discussed.

  18. An overview of the regulation of uranium mining, milling, refining and fuel fabrication

    The mining, milling, refining and fabrication of uranium into nuclear fuel are activities that have in common the handling of natural uranium. The occupational and environmental hazards resulting from these activities vary widely. Uranium presents a radiological hazard throughout, but the principal culprit is radium which creates an occupational hazard in the mine and mill and an environmental hazard in the waste products produced in both the mill and the refinery. The chemicals used in both these latter processes also present hazards. Fuel fabrication presents the least potential for occupational and environmental hazards. The Canadian Atomic Energy Control Board licenses eight plants, and one plant for the extraction of uranium from phosphoric acid. The licensing process is characterised by approval in stages, the placing of the burden of proof on the applicant, inspection at all stages, and joint review by all regulatory agencies involved

  19. Implications of an assessment of potential organic contamination of ground water at an inactive uranium mill

    Laws and regulations concerning remedial actions at inactive uranium mills explicitly recognize radiological and nonradiological hazards and may implicitly recognize the potential presence of hazardous wastes at these mill sites. Ground-water studies at the sites have placed an increasing emphasis on screening for priority pollutants. The Grand Junction, Colorado, mill site was deemed to have a high potential for the presence of organic compounds in ground water, and was chosen as a prototype for assessing the presence of organic compounds in ground water at inactive sites. Lessons learned from the assessment of organics at the Grand Junction site were used to develop a screening procedure for other inactive mill sites

  20. Spatial distribution of environmental risk associated to a uranium abandoned mine (Central Portugal)

    Antunes, I. M.; Ribeiro, A. F.

    2012-04-01

    The abandoned uranium mine of Canto do Lagar is located at Arcozelo da Serra, central Portugal. The mine was exploited in an open pit and produced about 12430Kg of uranium oxide (U3O8), between 1987 and 1988. The dominant geological unit is the porphyritic coarse-grained two-mica granite, with biotite>muscovite. The uranium deposit consists of two gaps crushing, parallel to the coarse-grained porphyritic granite, with average direction N30°E, silicified, sericitized and reddish jasperized, with a width of approximately 10 meters. These gaps are accompanied by two thin veins of white quartz, 70°-80° WNW, ferruginous and jasperized with chalcedony, red jasper and opal. These veins are about 6 meters away from each other. They contain secondary U-phosphates phases such as autunite and torbernite. Rejected materials (1000000ton) were deposited on two dumps and a lake was formed in the open pit. To assess the environmental risk of the abandoned uranium mine of Canto do Lagar, were collected and analysed 70 samples on stream sediments, soils and mine tailings materials. The relation between samples composition were tested using the Principal Components Analysis (PCA) (multivariate analysis) and spatial distribution using Kriging Indicator. The spatial distribution of stream sediments shows that the probability of expression for principal component 1 (explaining Y, Zr, Nb, La, Ce, Pr, Nd, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb, Hf, Th and U contents), decreases along SE-NW direction. This component is explained by the samples located inside mine influence. The probability of expression for principal component 2 (explaining Be, Na, Al, Si, P, K, Ca, Ti, Mn, Fe, Co, Ni, Cu, As, Rb, Sr, Mo, Cs, Ba, Tl and Bi contents), increases to middle stream line. This component is explained by the samples located outside mine influence. The spatial distribution of soils, shows that the probability of expression for principal component 1 (explaining Mg, P, Ca, Ge, Sr, Y, Zr, La, Ce, Pr

  1. Geochemical modeling of uranium mill tailings: a case study

    Liner failure was not found to be a problem when various acidic tailings solutions leached through liner materials for periods up to 3 y. On the contrary, materials that contained over 30% clay showed a decrease in permeability with time in the laboratory columns. The decreases in permeability noted above are attributed to pore plugging resulting from the precipitation of minerals and solids. This precipitation takes place due to the increase in pH of the tailings solution brought about by the buffering capacity of the soil. Geochemical modeling predicts, and x-ray characterization confirms, that precipitation of solids from solution is occurring in the acidic tailings solution/liner interactions studied. X-ray diffraction identified gypsum and alunite group minerals, such as jarosite, as having precipitated after acidic tailings solutions reacted with clay liners. The geochemical modeling and experimental work described above were used to construct an equilibrium conceptual model consisting of minerals and solid phases. This model was developed to represent a soil column. A computer program was used as a tool to solve the system of mathematical equations imposed by the conceptual chemical model. The combined conceptual model and computer program were used to predict aqueous phase compositions of effluent solutions from permeability cells packed with geologic materials and percolated with uranium mill tailings solutions. An initial conclusion drawn from these studies is that the laboratory experiments and geochemical modeling predictions were capable of simulating field observations. The same mineralogical changes and contaminant reductions observed in the laboratory studies were found at a drained evaporation pond (Lucky Mc in Wyoming) with a 10-year history of acid attack. 24 references, 5 figures 5 tables

  2. Environmental activities in uranium mining and milling. A Joint NEA/IAEA report

    This report on 'Environmental Activities in Uranium Mining and Milling' presents an overview of environmental activities related to uranium production. The profile of activities and concerns are based on survey responses from 29 countries and a review of relevant activities of the International Atomic Energy Agency and the OECD Nuclear Energy Agency. It also provides an overview of the reported interests of specialists working in the field, including environmental impact assessment, emissions to air and water, work environment, radiation safety, waste handling and disposal, mine and mill decommissioning and site restoration, and the regulation of these activities. The report reflects the increasing awareness in all countries of the need for environmental protection. For several years large programmes have been underway in several countries to clean up wastes from closed mines and mills. Many of these sites, particularly the older ones, were brought into production, operated and closed when little was known about environmental effects. At the time, little concern was given to the resulting environmental impacts. Currently, planning for and conducting uranium mine closure and mill decommissioning, together with site clean-up and restoration, are of almost universal concern. Mine closure and mill decommissioning activities have been or are being conducted in most of the countries with a history of uranium production. Information about several mine closures and mill decommissioning projects is included in this report

  3. A review of worldwide practices for disposal of uranium mill tailings

    The world's ever increasing need for energy has led to the construction of over 400 nuclear power stations since 1950. The fuel for these plants is processed from uranium which is mined in about 18 countries. The milling of uranium ore produces a waste product, the mill tailings, which contains about 85% of the ore's original radioactivity, process reagent residues and often a wide range of heavy metals, all of which have the potential to degrade the environment. The risk to human health and the environment has only been fully appreciated in relatively recent times. Earlier disposal plans for uranium mill tailings were frequently inadequate and resulted in adverse environmental impact. This review explains the nature of the risks to the environment and human health before describing many of the past disposal practices associated with uranium mill tailings. Current uranium mill tailings disposal practices in the major producer countries are then described, including remedial actions that have been undertaken to alleviate problems arising from earlier, inadequate and/or inappropriate disposal programs. A range of options available for tailings disposal is presented, together with a brief overview of legislation and regulations from a number of countries. Finally the report looks at how the issue might be addressed in the Alligator Rivers Region of Australia. 55 refs., 1 tab

  4. Radiation protection of workers from uranium mines and of the public living nearby uranium mining and milling facilities

    As part of the program of nuclear power development, the Russia Federation plans to increase uranium production and to improve supply from existing uranium mining and milling facilities. Moreover, development of new uranium ore deposits is also envisaged. A corollary of these developments is the placing of a high priority on environmental and human health protection Special attention should be paid to assurance of health protection both of workers and of the public living nearby such facilities. This paper reviews the status and development of understanding of facilities in the Russian Federation from a regulatory perspective. (author)

  5. Programmatic Environmental Report for remedial actions at UMTRA [Uranium Mill Tailings Remedial Action] Project vicinity properties

    This Environmental Report (ER) examines the environmental consequences of implementing a remedial action that would remove radioactive uranium mill tailings and associated contaminated materials from 394 vicinity properties near 14 inactive uranium processing sites included in the Uranium Mill Tailings Remedial Action (UMTRA) Project pursuant to Public Law 95--604, the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978. Vicinity properties are those properties in the vicinity of the UMTRA Project inactive mill sites, either public or private, that are believed to be contaminated by residual radioactive material originating from one of the 14 inactive uranium processing sites, and which have been designated under Section 102(a)(1) of UMTRCA. The principal hazard associated with the contaminated properties results from the production of radon, a radioactive decay product of the radium contained in the tailings. Radon, a radioactive gas, can diffuse through the contaminated material and be released into the atmosphere where it and its radioactive decay products may be inhaled by humans. A second radiation exposure pathway results from the emission of gamma radiation from uranium decay products contained in the tailings. Gamma radiation emitted from contaminated material delivers an external exposure to the whole body. If the concentration of radon and its decay products is high enough and the exposure time long enough, or if the exposure to direct gamma radiation is long enough, cancers (i.e., excess health effects) may develop in persons living and working at the vicinity properties. 3 refs., 7 tabs

  6. Uranium and thorium leached from uranium mill tailing of Guangdong province (CN)) and its implication for radiological risk

    The paper focused on the leaching behaviour of uranium (U) and thorium (Th) from uranium mill tailing collected from the Uranium Mill Plant in Northern Guangdong Province (CN)). Distilled water (pH 6) and sulphuric acid solution (pH 4 and 3) were used as solvent for the leaching over 22 weeks. It was found that the cumulative leach fraction from the mill tailing was 0.1, 0.1 and 0.7 % for U release, and overall 0.01 % for Th release, using distilled water, sulphuric acid solution of pH 4 and pH 3 as leaching agents, respectively. The results indicate that (1) the release of U and Th in uranium mill tailing is a slow and long-term process; (2) surface dissolution is the main mechanism for the release of U and Th when sulphuric acid solution of pH 3 is employed as the leaching agent; (3) both U and Th are released by diffusion when using sulphuric acid solution of pH 4 as the leaching agent and (4) U is released by surface dissolution, while Th is released by diffusion when using distilled water as the leaching agent. The implication for radiological risk in the real environment was also discussed. (authors)

  7. Impacts of new environmental and safety regulations on uranium mining, milling and waste management in China

    Nuclear power progress has triggered the development and innovation of nuclear fuel industries in China. At present the Chinese government has put more emphasis on industrial readjustment and technical innovation in uranium mining and milling in order to fuel the nuclear power development, satisfy environmental protection and improve economic efficiency of the industry. The current organizations and approval procedure for establishing regulations and the implementation and consequences of the regulations, technical polices and development strategies concerning uranium mining, milling, treatment of waste ores and mill tailings, and reduction of the workers' suffered exposure dose etc. in China are discussed and the economic, health and environmental impacts of the uranium mining and metallurgy with reformation achievement and the introduction of advanced technologies such as the in-situ leaching and heap leaching mining technologies are assessed in this paper. (author)

  8. Scientific basis for risk assessment and management of uranium mill tailings

    1986-01-01

    A National Research Council study panel, convened by the Board on Radioactive Waste Management, has examined the scientific basis for risk assessment and management of uranium mill tailings and issued this final report containing a number of recommendations. Chapter 1 provides a brief introduction to the problem. Chapter 2 examines the processes of uranium extraction and the mechanisms by which radionuclides and toxic chemicals contained in the ore can enter the environment. Chapter 3 is devoted to a review of the evidence on health risks associated with radon and its decay products. Chapter 4 provides a consideration of conventional and possible new technical alternatives for tailings management. Chapter 5 explores a number of issues of comparative risk, provides a brief history of uranium mill tailings regulation, and concludes with a discussion of choices that must be made in mill tailing risk management. 211 refs., 30 figs., 27 tabs.

  9. Scientific basis for risk assessment and management of uranium mill tailings

    A National Research Council study panel, convened by the Board on Radioactive Waste Management, has examined the scientific basis for risk assessment and management of uranium mill tailings and issued this final report containing a number of recommendations. Chapter 1 provides a brief introduction to the problem. Chapter 2 examines the processes of uranium extraction and the mechanisms by which radionuclides and toxic chemicals contained in the ore can enter the environment. Chapter 3 is devoted to a review of the evidence on health risks associated with radon and its decay products. Chapter 4 provides a consideration of conventional and possible new technical alternatives for tailings management. Chapter 5 explores a number of issues of comparative risk, provides a brief history of uranium mill tailings regulation, and concludes with a discussion of choices that must be made in mill tailing risk management. 211 refs., 30 figs., 27 tabs

  10. Hydrology of an abandoned uranium mine waste rock dump, Northern Territory

    Field studies were conducted on an abandoned, degraded uranium mine in Kakadu National Park to obtain waste rock dump runoff data to test the ability of a landform evolution model to predict gullying caused by concentrated flow. Runoff data were collected from natural rainfall events on a concentrated flow site and an overland flow erosion site on the waste rock dump at Scinto 6 mine. The data were used to fit parameters to a rainfall/runoff model using a non-linear regression package (NLFIT-DISTFW) which allows a single set of parameters to be fitted to four discharge hydrographs simultaneously. The model generally predicted peak discharge and the rising stage of the observed hydrographs well but there was some lag in the falling stage of the predicted hydrographs. Kinematic wave parameters are dependent on each other and the concentrated flow parameter set was not significantly different from the overland flow set. The infiltration parameter sets were statistically different and difference in cumulative infiltration between sites is controlled by sorptivity

  11. Groundwater leaching of neutralized and untreated acid-leached uranium-mill tailings

    Tailings neutralization was examined to determine the effect of neutralization on contaminant release. Column leaching of acid extracted uranium mill tailings from Exxon Highland Mill, Wyoming, Pathfinder Gas Hills Mill, Wyoming, and the Dawn Midnite Mill, Washington, resulted in the flushing of high concentrations of salts in the first four pore volumes of leachate, followed by a steady decrease to the original groundwater salt concentrations. Neutralization decreased the concentration of salts and radionuclides leaching from the tailings and decreased the volume of solution required to return the solution to the groundwater pH and EC. Radium-226 and uranium-238 leached quickly from the tailings in the initial pore volumes of both neutralized and unneutralized tailings, and then decreased significantly. 6 figures, 5 tables

  12. Remediation and corresponding radiological impact of French uranium mining and milling sites (COGEMA)

    As French uranium mines and mills are progressively ceasing operation, COGEMA has developed since 1991 an extensive remediation programme (see map for location and year of end of remediation work). The paper describes the radiological (and non radiological) monitoring system used to assess the radiological impact of uranium mining remaining after remediation. This includes air quality measurement (mainly gamma activity and radon 222 alpha potential energy), water and food chain sampling and analysis (uranium 238, radium 226 and lead 210). The monitoring network is particularly comprehensive around industrial sites grouping mines, mills and uranium mill tailings storage facilities. Different examples of real continuous measurement results collected before and after remediation and plotted on curves are presented. Main observations and evolutions are discussed highlighting some of the main issues related to uranium mines and mill remediation. Differences in gamma measurement due to geological environment or seasonal variations in radon 222 alpha potential energy stress the difficulty of choosing a background station. Radon 222 alpha potential energy concentration evolution may be linked to the placement of the cover on top of the mill tailings pile. Evolution of quality from the drainage system to the release in the river measures the efficiency of the water treatment plant which may become useless as the water quality naturally improves. Highest total added doses to members of the public, using realistic scenario and dose factors as recommended by European Directive 96/29 should be near 1 mSv. In the environment of uranium mines and mill tailings storages, measurement and dose to members of the public are low (compared to some modelisation results) and remediation improves and perpetuate this limited impact. (author)

  13. Radon emanation from backfilled mill tailings in underground uranium mine

    Coarser mill tailings used as backfill to stabilize the stoped out areas in underground uranium mines is a potential source of radon contamination. This paper presents the quantitative assessment of radon emanation from the backfilled tailings in Jaduguda mine, India using a cylindrical accumulator. Some of the important parameters such as 226Ra activity concentration, bulk density, bulk porosity, moisture content and radon emanation factor of the tailings affecting radon emanation were determined in the laboratory. The study revealed that the radon emanation rate of the tailings varied in the range of 0.12–7.03 Bq m−2 s−1 with geometric mean of 1.01 Bq m−2 s−1 and geometric standard deviation of 3.39. An increase in radon emanation rate was noticed up to a moisture saturation of 0.09 in the tailings, after which the emanation rate gradually started declining with saturation due to low diffusion coefficient of radon in the saturated tailings. Radon emanation factor of the tailings varied in the range of 0.08–0.23 with the mean value of 0.21. The emanation factor of the tailings with moisture saturation level over 0.09 was found to be about three times higher than that of the absolutely dry tailings. The empirical relationship obtained between 222Rn emanation rate and 226Ra activity concentration of the tailings indicated a significant positive linear correlation (r = 0.95, p < 0.001). This relationship may be useful for quick prediction of radon emanation rate from the backfill material of similar nature. - Highlights: • 222Rn emanation rate of the backfilled tailings varied from 0.12 to 7.03 Bq m−2 s−1. • Good correlation between 222Rn emanation rate and 226Ra activity concentration found. • Higher 222Rn emanation rate was obtained from moist backfilled tailings. • Radon emanation factor of the backfilled tailings varied in the range of 0.08–0.23. • Emanation factor of wet tailings was about 3 times higher than that of dry tailings

  14. Uranium mining and milling sites in Argentina: environmental radiological monitoring (1980-1994)

    Environmental radiological monitoring in the vicinity of uranium mining and milling plants in Argentina is performed on a routine basis, in order to assess the possibility of significant environmental contamination due to uranium mill wastes and mill tailings of plants still operating or those where the exploitation have concluded. Dissolved natural uranium and 226Ra concentrations in surface waters are measured in samples taken from rivers near the mills, according to a special monitoring plan set up for each facility. In addition, 222Rn emanation rates from ore tailings are measured at times. In this paper the environmental radiological monitoring program results obtained for the 1980-1994 period are shown. From the data analyses it can be concluded that there are not significant differences for the concentrations of the radionuclides of interest, between the surface water samples taken from river location above and below the plants discharge points. Besides, no significant exposure results for the population living in the surrounding areas due to the uranium mining and milling plants operation or their wastes. (author). 2 refs., 5 figs

  15. Closeout of uranium mines and mills: A review of current practices

    The present report is a first step in gathering information on the assessment and control of the long term (over a few centuries) impact of uranium mining and milling waste. Its intention is to outline several examples of worldwide experience. It contains summaries of current closeout practices which have not previously been presented in a singly publication. It is expected to provide necessary information to Member States to formulate meaningful decisions for adequately controlling impacts resulting from uranium mines and mills waste materials. The information contained herein may also be valuable as background material for developing relevant guidance in this subject area, for example within the IAEA Safety Standards Programme. Refs, figs, tabs

  16. Safe management of wastes from the mining and milling of uranium and thorium ores

    Wastes from the mining and milling of uranium and thorium ores pose potential environmental and public health problems because of their radioactivity and chemical composition. This document consists of two parts: a Code of Practice (Part I) and a Guide to the Code (Part II). The Code sets forth the requirements for the safe and responsible handling of the wastes resulting from the mining and milling of uranium and thorium ores, while the Guide presents further guidance in the use of the Code together with some discussion of the technology and concepts involved

  17. GYP-600 inertia cone crusher applied in fine crushing in a uranium mill

    GYP-600 inertia cone crusher is a high efficiency equipment. It not only has the characteristics of a high crush rate, less energy, and easy installment, but also can prevent over-crush, and control the mine particle size in the range of flow need. The application in a uranium mill indicated that it can satisfy mine particle size and output of leakage lixiviation flow in the uranium mill, solve the antinomy problem between the mine hard to crush and over-crush, and get the remarkable economy benefit. (authors)

  18. Asphalt emulsion radon barrier systems for uranium mill tailings: A summary of the technology

    Pacific Northwest Laboratory (PNL), under contract to the U.S. Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field-tested at the tailings site in Grand Junction, Colorado. Results from laboratory and field tests indicate that this system effectively reduces radon release to near-background levels (-2s-1) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and a cost analysis indicates that asphalt emulsion covers are competitive with other cover systems

  19. Mobilization of radionuclides from uranium mill tailings and related waste materials in anaerobic environments

    Specific extraction studies in our laboratory have shown that iron and manganese oxide- and alkaline earth sulfate minerals are important hosts of radium in uranium mill tailings. Iron- and sulfate-reducing bacteria may enhance the release of radium (and its analog barium) from uranium mill tailings, oil field pipe scale [a major technologically enhanced naturally occurring radioactive material (TENORM) waste], and jarosite (a common mineral in sulfuric acid processed-tailings). These research findings are reviewed and discussed in the context of nuclear waste forms (such as barium sulfate matrices), radioactive waste management practices, and geochemical environments in the Earth's surficial and shallow subsurface regions. (author)

  20. Radiological impact assessment of uranium mining and milling

    This thesis presents improved methods for predicting and assessing the dose to humans resulting from uranium mining and milling operations with the primary focus being on the local and regional component of dose to members of the public. Throughout, examples are presented from operating (Ranger) and rehabilitated (Nabarlek) uranium mine in the tropical Alligator Rivers Region of the Northern Territory of Australia. Four major pathways are examined with relation to the Ranger mine dispersion of radionuclides in creek waters with uptake into the food chain, dispersion of radionuclides in groundwater, atmospheric transport of radon and radon progeny, and wet and dry deposition of activity on airborne dust. An improved model has been developed for the prediction of dose following release of wastewaters from Ranger into the Magela Creek system. The available data on radionuclide uptake into organism of the creek system were reviewed for incorporation into the model. Calculations using the model indicate that the most important organism for radiological impact are freshwater mussels, followed by fish. The behaviour of U, Ra, Th and Ac in the groundwater system in the vicinity of the Ranger tailings dam has been investigated using alpha- and gamma-spectrometry techniques. Ra, U and Ac isotope concentrations have increased with time in some bores, but this is shown in the case of Ra to be due to removal of native Ra from the aquifer rocks by increasing cation concentrations. Formation of barite is also occurring in the vicinity of some bores, leading to a removal of some Ra from solution. The situation with U is less clear. U-234/U-238 ratios have decreased with increasing U-238 concentrations in a number of bores, but generally remain above the tailings dam water value of 1.00. The most likely explanation is that the increasing size of mine structures such as waste rock dumps and ore stockpile has led to a change in conditions in the aquifer such that U ha become

  1. Measurements of 234U, 238U and 230Th in excreta of uranium-mill crushermen

    Uranium and thorium levels in excreta of uranium mill crushermen who are routinely exposed to airborne uranium ore dust were measured. The purpose was to determine whether 230Th was preferentially retained over either 234U or 238U in the body. Urine and fecal samples were obtained from fourteen active crushermen with long histories of exposure to uranium ore dust, plus four retired crushermen and three control individuals for comparison. Radiochemical procedures were used to separate out the uranium and thorium fractions, which were then electroplated on stainless steel discs and assayed by alpha spectrometry. Significantly greater activity levels of 234U and 238U were measured in both urine and fecal samples obtained from uranium mill crushermen, indicating that uranium in the inhaled ore dust was cleared from the body with a shorter biological half-time than the daughter product 230Th. The measurements also indicated that uranium and thorium separate in vivo and have distinctly different metabolic pathways and transfer rates in the body. The appropriateness of current ICRP retention and clearance parameters for 230Th in ore dust is questioned

  2. Annual status report on the Uranium Mill Tailings Remedial Action Program

    This eleventh annual status report summarizes activities of the Uranium Mill Tailings Remedial Action (UMTRA) Project undertaken during Fiscal Year (FY) 1989 by the US Department of Energy (DOE) and other agencies. Project goals for FY 1990 are also presented. An annual report of this type was a statutory requirement through January 1, 1986, pursuant to the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978, Public Law (PL) 95--604. The DOE will continue to submit an annual report through project completion in order to inform the public of yearly project status. Title I of the UMTRCA authorizes the DOE, in cooperation with affected states and Indian tribes within whose boundaries designated uranium processing sites are located, to provide a program of assessment and remedial action at such sites. The purpose of the remedial action is to stabilize and control the tailings and other residual radioactive materials located on the inactive uranium processing sites in a safe and environmentally sound manner and to minimize or eliminate potential radiation health hazards. Commercial and residential properties in the vicinity of designated processing sites that are contaminated with material from the sites, herein referred to as ''vicinity properties,'' are also eligible for remedial action. Included in the UMTRA Project are 24 inactive uranium processing sites and associated vicinity properties located in 10 states, and the vicinity properties associated with Edgemont, South Dakota, an inactive uranium mill currently owned by the Tennessee Valley Authority (TVA)

  3. Screening of plant species as ground cover on uranium mill tailings

    The concept of construction of dams or holding areas for uranium mill tailings is relatively new in India and to date there is only one such facility being maintained by Uranium Corporation of India Limited (UCIL) at Jaduguda in Jharkhand. Due to the residual nature of radionuclides, chiefly uranium and its daughter products, special emphasis is given to the engineering aspects of the mill tailings ponds so as to ensure safety to general public for at least 200 years. Once a mill tailings pond reaches to its full capacity, creation of barrier layers over the mill tailings to prevent seepage of rain water and also erosion of mill tailings due to wind and water are advocated and a number of procedures are followed worldwide. Taking the extraordinary period of public safety to be assured, providing soil covers along with contouring and appropriate slopes over which vegetation is grown is gaining popularity. The vegetation not only reduces the impact of rain water hitting the soil cover, thereby reducing the soil erosion, but also lowers the moisture in the soil cover by extensive evapotranspiration, ensuring long term hydrological separation of the mill tailings underneath. Based on set criteria, applicable to the field scenario of mill tailings, a screening experiment was conducted under pot culture conditions to evaluate the survival and growth of different plant species. The plants after germination and hardening were transplanted into beakers containing mill tailings and periodical measurements on appropriate morphological characteristics such as plant height, length of twiners, number of tillers and number of leaves were recorded and evaluated. Of the twenty species tested in mill tailings, significant differences were noticed in the vigour of growth and several plant species could indeed establish well completing their life cycle including flowering and seed setting. Further, several leguminous species could also produce root nodules. It appears that the

  4. Stabilizing the tailing dam at Hengyang Uranium mill

    The engineering measures combined with vegetation for stabilizing tailing dam at Hengyang unanium mill is described briefly. Improvements on dam safety, environment management and dam life time that have been achieved over the last 5 years are presented

  5. Mining and milling of uranium ore: Indian scenario

    The occurrence of uranium minerals in Singhbhum Thrust belt of Eastern India has been known since 1937. In 1950, a team of geologists of the Atomic Minerals Division was assigned to closely examine this 160 km long belt. Since then, several occurrences of uranium have been found and a few of them have sufficient grade and tonnage for commercial exploitation. In 1967, the Government of India formed Uranium Corporation of India Ltd., under the administrative control of the Department of Atomic Energy, with the specific objective of mining and processing of uranium ore and produce uranium concentrates. At present the Corporation operates three underground uranium mines, one ore processing plant with expanded capacity, and two uranium recovery plants. Continuing investigations by the Atomic Mineral Division has discovered several new deposits and favourable areas. The most notable is the large Domiasiat deposit of the sandstone type found in the State of Meghalaya. This deposit is now being considered for commercial exploitation using the in-situ leaching technology. (author)

  6. Key programmatic steps and activities for implementing the Uranium Mill Tailings Remedial Action Project

    The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA) was enacted based upon findings by Congress ''that uranium mill tailings located at active and inactive hazard to the public, and that protection of the public health, safety and welfare, and the regulations of interstate commerce, require that every reasonable effort be made to provide for the stabilization, disposal, and control in a safe and environmentally sound manner of such tailings in order to prevent or minimize radon diffusion into the environment and to prevent or minimize other environmental hazards from such tailings.'' A general understanding of the steps leading to elimination of the hazards associated with designated uranium mill tailings sites, and the parties involved in that effort, are presented in this document. A representative schedule is also presented in this document to show both program sequence and activity interdependence. Those activities that have the most potential to influence program duration, because of the significant amount of additional time that may be required, include identification and selection of a suitable site, field data collection delays due to weather, actual acquisition of the designated or alternate disposal site, construction delays due to weather, and site licensing. This document provides an understanding of the steps, the sequence, the parties involved, and a representative duration of activities leading to remedial action and cleanup at the designated inactive uranium mill tailings sites. 10 refs., 5 figs., 1 tab

  7. Study of the distribution of radium on pure solid phases: application to uranium mill tailings

    Among several minerals, clayey materials which are found in almost all kind of uranium mill tailings (granitic and sedimentary ores) present strong affinities towards numerous cations. A batch study of the radium distribution onto kaolinite and montmorillonite in different chemical conditions has shown strong dependence of the Ra2+ sorption with pH and Na+ concentration of the solution. A cation exchange modelling is proposed in order to explain these variations and two kinds of sorption sites have been pointed out on kaolinite. The selectivity coefficients between sodium and radium kNa/Ra were determined: 103.2 kg.l-1 for the first site (pH 5.2 kg.l-1 for the second one (pH > 8). For montmorillonite, the kNa/Ra value obtained at pH 7 is 102.2 kg.l-1. These data have been used for the radium behaviour modelling in an uranium mill tailings site. The modelling results show that the presence of clays in uranium mill tailings warrants a negligible part of radium in the radiological impact via aquatic pathway. Sequential extraction procedure applied on uranium mill tailings has been realized to confirm our modelling results. (orig.)

  8. Cost-benefit analysis of tailings and waste rocks disposal in decommissioning uranium mine and mill

    According to the three principles in radiation protection, the objective function, the constraining function and the limit equation of tailings and waste rocks disposal in decommission uranium mine and mill have been set up with cost-benefit analysis method. It is an optimum analysis method

  9. The disposal techniques and correlation problems of uranium mine and mill facilities decommissioning project

    Investigation and study in recent years about disposal techniques of uranium mine and mill facilities decommissioning project, effect of tailing water on underground water, detecting separation rate of radon in tailings and covering techniques are summarized. It has reference value for drawing up disposal plan and putting into effect in field

  10. Evaluation of wastewater treatment systems for the Uranium Mill Tailings Remedial Action Project - Lakeview, Oregon site

    During remedial action at the Lakeview, Oregon, Uranium Mill Tailings Remedial Action Project site, unexpectedly large volumes of contaminated water required quick identification and design of a treatment facility capable of meeting Oregon release limits. A laboratory program was prepared and executed to determine the efficiency and cost-effectiveness of several alternative treatment approaches, and an optimum system was selected, designed and deployed

  11. What comes after active remediation: Long term challenges at uranium mining and milling sites

    Remediation plans for uranium mining and milling sites often tacitly assume that a certain amount of maintenance has to be carried out for almost unlimited time spans. The paper highlights the relevant issues and attempts to outline the conceptual, management and technical problems and challenges of maintaining institutional control over possibly hundreds or even thousands of years. (author)

  12. Environmental control technology for mining and milling low-grade uranium resources

    This study examined the type and level of wastes that would be generated in the mining and milling of U3O8 from four potential domestic sources of uranium. The estimated costs of the technology to control these wastes to different degrees of stringency are presented

  13. Sustainability of uranium mining and milling: toward quantifying resources and eco-efficiency.

    Mudd, Gavin M; Diesendorf, Mark

    2008-04-01

    The mining of uranium has long been a controversial public issue, and a renewed debate has emerged on the potential for nuclear power to help mitigate against climate change. The central thesis of pro-nuclear advocates is the lower carbon intensity of nuclear energy compared to fossil fuels, although there remains very little detailed analysis of the true carbon costs of nuclear energy. In this paper, we compile and analyze a range of data on uranium mining and milling, including uranium resources as well as sustainability metrics such as energy and water consumption and carbon emissions with respect to uranium production-arguably the first time for modern projects. The extent of economically recoverable uranium resources is clearly linked to exploration, technology, and economics but also inextricably to environmental costs such as energy/water/chemicals consumption, greenhouse gas emissions, and social issues. Overall, the data clearly show the sensitivity of sustainability assessments to the ore grade of the uranium deposit being mined and that significant gaps remain in complete sustainability reporting and accounting. This paper is a case study of the energy, water, and carbon costs of uranium mining and milling within the context of the nuclear energy chain. PMID:18505007

  14. Final environmental statement related to the United Nuclear Corporation, Morton Ranch, Wyoming Uranium Mill (Converse County, Wyoming)

    Impacts from Morton Ranch Uranium Mill will result in: alterations of up to 270 acres occupied by the mill facilities; increase in the existing background radiation levels; socioeconomic effects on Glenrock and Douglas, Wyoming. Solid waste material (tailings solids) from the mill will be deposited onsite in exhausted surface mine pits. Any license issued for the Morton Ranch mill will be subject to conditions for the protection of the environment

  15. Final environmental statement related to the United Nuclear Corporation, Morton Ranch, Wyoming Uranium Mill (Converse County, Wyoming)

    1979-02-01

    Impacts from Morton Ranch Uranium Mill will result in: alterations of up to 270 acres occupied by the mill facilities; increase in the existing background radiation levels; socioeconomic effects on Glenrock and Douglas, Wyoming. Solid waste material (tailings solids) from the mill will be deposited onsite in exhausted surface mine pits. Any license issued for the Morton Ranch mill will be subject to conditions for the protection of the environment.

  16. Correlation analysis of first phase monitoring results for uranium mill workers

    This report describes the determination of the existence and extent of correlations in data obtained during the first phase study of urinalysis, personal air sampling and lung burden measurements of uranium mill workers. It was shown that uranium excretions in urine as determined from spot urine samples at the end of the shift were correlated with intakes calculated from personal air sampling data at the 90 percent confidence level. When there are large variations in the rate of urine production, the time rate or uranium elimination was shown to be a more reliable indicator of uranium excretion than the uranium concentration in urine. Based on correlations between phantom and subject lung burden measurements in the presence of changing background radiation levels, a comparative lung burden measurement technique was developed. The sensitivity and accuracy of the method represent a significant improvement and the method is as applicable to females as to males

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

    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

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

    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.

  19. National/international R and D programs on uranium mill tailings

    The mining and milling of uranium ores results in the production of large quantities of wastes containing low concentrations of radionuclides such as uranium, thorium, radium, radon and their daughter products. The current concern of the regulatory authorities is with the extent of the problems and the disposal methods that must be required now to ensure that an acceptable level of protection is maintained in the long term. This concern is the subject of a number of R and D programs. In Canada, the Technical Planning Group on Uranium Tailings was established to review ongoing activities and to plan a research program on the management of wastes after the mine and mill have shut down. The Group has completed its review and a report containing its conclusions and recommendations for a proposed national R and D program has been prepared. Included is a proposal for a centralized organizational structure for the coordination and managment of the total program which is to be supported jointly by the federal government, two (Ontario, Saskatchewan) provincial governments, and uranium producers. At the international level, the Nuclear Energy Agency originated, in 1979, a program to study the extent of the long-term problems of uranium mill tailings, and to develop an internationally acceptable methodology for making rational decisions regarding their long-term management taking into account the ICRP principles and system of dose limitation

  20. Study and application on lean resin converting in uranium mill

    The field test about sulphuric acid used to convert lean resin was finished. The results indicated sulphuric acid could replace chlorin in lean resin and could be reclaimed to desorption procedure. The consumption of NaCl decreased, the chlorin concentration of tailing decreased too. Both of uranium loss and waste water volume were reduced. The uranium concentration of tailing decreased and energy saving and emission reduction can be achieved. (authors)

  1. Metal bioaccumulation, genotoxicity and gene expression in the European wood mouse (Apodemus sylvaticus) inhabiting an abandoned uranium mining area

    Lourenço, Joana, E-mail: joanalourenco@ua.pt [Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); CESAM, Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Pereira, Ruth [Departamento de Biologia, Faculdade de Ciências, Universidade do Porto, Rua do Campo Alegre, 4169-007 Porto (Portugal); CESAM, Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); Gonçalves, Fernando; Mendo, Sónia [Departamento de Biologia, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal); CESAM, Centro de Estudos do Ambiente e do Mar, Universidade de Aveiro, Campus Universitário de Santiago, 3810-193 Aveiro (Portugal)

    2013-01-15

    Genotoxic effects caused by the exposure to wastes containing metals and radionuclides were investigated in the European wood mice (Apodemus sylvaticus). The animals were captured in the surroundings of an abandoned uranium mining site. DNA damage was assessed by comet assay; gene expression and single nucleotide polymorphisms (SNPs) were assessed, respectively, by Real-Time PCR and melt curve analysis. The bioaccumulation of metals in the liver, kidney and bones was also determined to help clarify cause–effect relationships. Results confirmed the bioaccumulation of cadmium and uranium in organisms exposed to uranium mining wastes. P53 gene was found to be significantly up-regulated in the liver of those organisms and SNPs in the Rb gene were also detected in the kidney. Our results showed that uranium mining wastes caused serious DNA damage resulting in genomic instability, disclosed by the significant increase in DNA strand breaks and P53 gene expression disturbance. These effects can have severe consequences, since they may contribute for the emergence of serious genetic diseases. The fact that mice are often used as bioindicator species for the evaluation of risks of environmental exposure to humans, raises concerns on the risks for human populations living near uranium mining areas. - Highlights: ► Long term effects of chronic pollution in natural population of rodents. ► Bioaccumulation of cadmium and uranium by organisms exposed to uranium wastes. ► P53 upregulation in the liver and SNPs in the Rb gene detected in the kidney. ► Significant DNA damages detected by the comet assay. ► Concerns on the risks of human populations living nearby uranium mining areas.

  2. Metal bioaccumulation, genotoxicity and gene expression in the European wood mouse (Apodemus sylvaticus) inhabiting an abandoned uranium mining area

    Genotoxic effects caused by the exposure to wastes containing metals and radionuclides were investigated in the European wood mice (Apodemus sylvaticus). The animals were captured in the surroundings of an abandoned uranium mining site. DNA damage was assessed by comet assay; gene expression and single nucleotide polymorphisms (SNPs) were assessed, respectively, by Real-Time PCR and melt curve analysis. The bioaccumulation of metals in the liver, kidney and bones was also determined to help clarify cause–effect relationships. Results confirmed the bioaccumulation of cadmium and uranium in organisms exposed to uranium mining wastes. P53 gene was found to be significantly up-regulated in the liver of those organisms and SNPs in the Rb gene were also detected in the kidney. Our results showed that uranium mining wastes caused serious DNA damage resulting in genomic instability, disclosed by the significant increase in DNA strand breaks and P53 gene expression disturbance. These effects can have severe consequences, since they may contribute for the emergence of serious genetic diseases. The fact that mice are often used as bioindicator species for the evaluation of risks of environmental exposure to humans, raises concerns on the risks for human populations living near uranium mining areas. - Highlights: ► Long term effects of chronic pollution in natural population of rodents. ► Bioaccumulation of cadmium and uranium by organisms exposed to uranium wastes. ► P53 upregulation in the liver and SNPs in the Rb gene detected in the kidney. ► Significant DNA damages detected by the comet assay. ► Concerns on the risks of human populations living nearby uranium mining areas

  3. Geochemical characterization of geologic materials beneath the proposed Burro Canyon uranium mill tailing disposal cell

    Geologic materials from beneath the proposed Burro Canyon uranium mill tailings disposal site near Slick Rock, Colorado, were characterized to determine hydraulic and geochemical properties. These parameters are crucial to predict if uranium mill tailings leachate represents a potential threat to underlying groundwater resources. Batch tests were conducted to determine the reactivity of geologic materials with respect to molybdenum, selenium, and uranium. Distribution coefficients for Se, Mo, and U are less than 1, indicating low attenuation. Analysis of the -2 μ fraction of the Burro Canyon Formation mudstone indicates that illites and glauconite are the major phases with minor montmorillonite and kaolinite. Adsorption of Mo, Se, and U onto clay minerals as a mechanism of attenuation is discussed. (author)

  4. Uranium mining and milling work force characteristics in the western US

    This report presents the results of a survey of the socioeconomic characteristics associated with 11 uranium mine and mill operations in 5 Western States. Comparisons are made with the socioeconomic characteristics of construction and operating crews for coal mines and utility plants in eight Western States. Worker productivity also is compared with that in similar types of coal and uranium mining operations. We found that there existed no significant differences between the socioeconomic characteristics of construction and operating crews and the secondary employment impacts associated with uranium mines and mills when compared with those associated with coal mines and utility plants requiring similar skills at comparable locations. In addition, our survey includes a comparison of several characteristics associated with the households of basic and nonbasic work forces and concludes that significant changes have occurred in the last 5 yr. Accordingly, we recommend additional monitoring and updating of data used in several economic forecasting models to avoid unwarranted delays in achieving national energy goals

  5. Estimated dose to man from uranium milling via the terrestrial food-chain pathway

    One of the major pathways of radiological exposure to man from uranium milling operations is through the terrestrial food chain. Studies by various investigators have shown the extent of uptake and distribution of U-238, U-234, Th-230, Ra-226, Pb-210, and Po-210 in plants and animals. These long-lived natural radioisotopes, all nuclides of the uranium decay series, are found in concentrated amounts in uranium mill tailings. Data from these investigations are used to estimate the dose to man from consumption of beef and milk contaminated by the tailings. This dose estimate from this technologically enhanced source is compared with that from average normal dietary intake of these radionuclides from natural sources

  6. Canadian uranium mines and mills evolution of regulatory expectations and requirements for effluent treatment

    The regulation of uranium mining in Canada has changed over time as our understanding and concern for impacts on both human and non-human biota has evolved. Since the mid-1970s and early 1980s, new uranium mine and mill developments have been the subject of environmental assessments to assess and determine the significance of environmental effects throughout the project life cycle including the post-decommissioning phase. Water treatment systems have subsequently been improved to limit potential effects by reducing the concentration of radiological and non-radiological contaminants in the effluent discharge and the total loadings to the environment. This paper examines current regulatory requirements and expectations and how these impact uranium mining/milling practices. It also reviews current water management and effluent treatment practices and performance. Finally, it examines the issues and challenges for existing effluent treatment systems and identifies factors to be considered in optimizing current facilities and future facility designs. (author)

  7. Application of risk based cost-benefit analyses for decision making in environmental restoration regions of uranium mining and milling sites

    Active and abandoned uranium mining and milling sites can represent complex environmental situations, where health risks and environmental detriments may result from radon exhalation and dispersion of radioactive dust from mine wastes as well as from the discharge of contaminated mine waters into surface and groundwaters. The paper outlines a methodology for the evaluation of remediation measures in the framework of the closeout of uranium mining and milling facilities in eastern Germany. The decision making process for the remediation of large waste rock dumps (total volume approximately 125 million m3) at a uranium mining site is used as an example. In the context of this approach, appropriate and sustainable remediation measures should (1) reduce the environmental impacts from the waste rock dumps to acceptable levels, and (2) have the best cost-benefit ratio (i.e. the 'lowest overall costs'). These 'overall costs' comprise direct short term costs for remediation measures (e.g. application of engineered covers, backfill of mine waste into open pits), long term costs (e.g. for monitoring, maintenance, seepage collection/treatment), as well as the monetary equivalents of remaining risks for human life and health and impacts on the environment - evaluated by geochemical modelling/air dispersion modelling - in the long term. Uncertainties in the costs and benefits of the remediation measures are addressed by stochastic methods (Monte Carlo simulations). (author)

  8. A case study of a large open pit uranium AML [Abandoned Mine Land] Project Gas Hills, Wyoming

    The Abandoned Mine Lands Program (AML), authorized under the Surface Mining Control and Reclamation Act of 1977 provides funding for the abatement of health and safety hazards on lands disturbed by mining prior to enactment of the Act. A good example of the implementation of the AML Program in Wyoming is the A-8 Pit. The reclamation site is located in the East Gas Hills Uranium Mining District of Wyoming. Reclamation activities include selective handling of 3.5 million cubic yards of backfill, controlling pit dewatering and water treatment, installing second order drainage channel and riprap control structures, and salvaging sufficient coversoils and topsoils for site revegetation

  9. Converting the Caetité Mill Process to Enhance Uranium Recovery and Expand Production

    The Caetité uranium mill was commissioned in 2000 to produce about 340 t U per year from an uranium ore averaging 0.29% U3O8. This production is sufficient to supply the two operating nuclear power plants in the country. As the Brazilian government has recently confirmed its plan to start building another ones from 2009, the uranium production will have to expand its capacity in the next two years. This paper describes the changes in the milling process that are being evaluated in order to not only increase the production but also the uranium recovery, to fulfil the increasing local demand. The heap leaching process will be changed to conventional tank agitated leaching of ground ore slurry in sulphuric acid medium. Batch and pilot plant essays have shown that the uranium recovery can increase from the 77% historical average to about 93%. As the use of sodium chloride as the stripping agent has presented detrimental effects in the extraction and stripping process, two alternatives are being evaluated for the uranium recovery from the PLS: (a) uranium peroxide precipitation at controlled pH from a PLS that was firstly neutralized and filtered. Batch essays have shown good results with a final calcined precipitate averaging 99% U3O8. Conversely the results obtained at the first pilot plant essay has shown that the precipitation conditions of the continuous process calls for further evaluation. The pilot plant is being improved and another essay will be carried out. (b) uranium extraction with a tertiary amine followed by stripping with concentrated sulphuric acid solution. Efforts are being made to recover the excess sulphuric acid from the pregnant stripping solution to enhance the economic viability of the process and to avoid the formation of a large quantity of gypsum in the pre-neutralization step before the uranium peroxide precipitation. (author)

  10. Technical developments in uranium mining and milling in India

    Full text: Uranium mining in India made a formal beginning with formation of Uranium Corporation of India Ltd. in October 1967. In accordance with the mandate of producing and meeting the uranium requirement of the country, UCIL has continuously upgraded the technology and operating practices with regard to its core activities - uranium ore mining, processing and disposal of tailings. Jaduguda underground mine in Singhbhum east district of Jharkhand (Eastern India) was commissioned in 1968. Regular mining operations started with the sinking of a fully lined vertical shaft and equipping the same with two winders which support a cage and a skip. This was followed by commissioning of Bhatin mine in 1986, Narwapahar mine in 1995, Turamdih mine in 2003, and Bagjata mine in 2008. New mines adopt decline method of entry and use of track less equipment in cut-and fill method of stoping. Vertical shafts provide access to deeper levels for ore and men and material hoisting. Banduhurang, the first open cast uranium mine of the country was commissioned in Jan 2009. New mine at Tummalapalle in Andhra Pradesh and underground mine at Mohuldih in Jharkhand are under construction. The mine at Tummalapalle has been planned with three declines along the apparent dip of the orebody and breast stoping method using trackless equipment. At Lambapur-Peddagattu in Andhra Pradesh, room and pillar method of stoping is proposed for underground mines with deployment of low profile drilling and loading-dumping equipment. The conventional way of processing of uranium ore in India is through hydro-metallurgical route followed by acid leaching and MDU precipitation. Jaduguda plant commissioned in 1968 has been expanded in two phases and 3rd phase expansion is underway. The plant at Turamdih encompasses new equipment and monitoring systems like apron feeder, horizontal belt filter, high rate thickener, particle size monitor etc. Both Jaduguda and Turamdih plants are designed to produce magnesium

  11. Environmental assessment of remedial action at the Slick Rock uranium mill tailings sites, Slick Rock, Colorado

    NONE

    1995-01-01

    The Uranium Mill Tailings Radiation Control Act of 1978, hereafter referred to as the UMTRCA, authorized the US Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miguel County. The purpose of the cleanup is to reduce the potential health effects associated with the radioactive materials remaining on the processing sites and on vicinity properties (VPs) associated with the sites. The US Environmental Protection Agency (EPA) promulgated standards for the UMTRCA that contained measures to control the contaminated materials and to protect the ground water from further degradation. The sites contain concrete foundations of mill buildings, tailings piles, and areas contaminated by windblown and waterborne radioactive tailings materials. The proposed action is to remediate the UC and NC sites by removing all contaminated materials within the designated site boundaries or otherwise associated with the sites, and relocating them to, and stabilizing them at, a location approximately 5 road mi (8 km) northeast of the processing sites on land administered by the US Bureau of Land Management (BLM). Remediation would be performed by the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project.

  12. In-situ grouting of uranium-mill-tailings piles: an assessment

    Passage in 1978 of the Uranium Mill Tailings Radiation Control Act (UMTRCA) initiated a program of remedial action for 22 existing mill tailings piles generated in the period 1940 to 1970 as part of the nation's defense and nuclear power programs. The presence of these piles poses potential health and environmental contamination concerns. Possible remedial actions proposed include multilayer covers over the piles to reduce water infiltration, reduce radon gas releases, and reduce airborne transport of tailings fines. In addition, suggested remedial actions include (1) the use of liners to prevent groundwater contamination by leachates from the piles and (2) chemical stabilization of the tailings to retain the radioactive and nonradioactive sources of contamination. Lining of the piles would normally be applicable only to piles that are to be moved from their present location such that the liner could be placed between the tailings and the groundwater. However, by using civil engineering techniques developed for grouting rocks and soils for strength and water control, it may be possible to produce an in situ liner for piles that are not to be relocated. The Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project Office requested that ORNL assess the potential application of grouting as a remedial action. This report examines the types of grouts, the equipment available, and the costs, and assesses the possibility of applying grouting technology as a remedial action alternative for uranium mill tailings piles

  13. Radionuclides in the terrestrial ecosystem near a Canadian uranium mill -- Part 1: Distribution and doses

    Soils, vegetation, small mammals, and birds were measured for uranium series radionuclides at three sites near the operating Key Lake uranium mill in northern Saskatchewan. Sites, impacted by windblown tailings and mill dust, had significantly higher concentrations of uranium, 226Ra, 210Pb, and 210Po in soils, litter, vegetation, tree needles and twigs, small mammals, and birds, compared to a control site. Samples were collected from both upland jackpine and black spruce bog habitats in triplicate at each site. Both habitats were similar in radionuclide accumulation. Absorbed doses averaged 0.92, 8.4, and 4.9 mGy y-1 to small mammals and 2.0, 5.8, and 2.8 mGy y-1 to Lincoln's sparrows at the control, tailings, and mill sites, respectively. These doses do not include doses from short-lived radon progeny. The majority of the dose increment at the tailings and mill sites was due to 226Ra, whereas it was 210Po at the control site. Thus, use of a radiation weighting factor of 20 for alpha radiation raised equivalent doses (in mSv y-1) by nearly a factor of 20

  14. Environmental assessment of remedial action at the Slick Rock uranium mill tailings sites, Slick Rock, Colorado

    The Uranium Mill Tailings Radiation Control Act of 1978, hereafter referred to as the UMTRCA, authorized the US Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miguel County. The purpose of the cleanup is to reduce the potential health effects associated with the radioactive materials remaining on the processing sites and on vicinity properties (VPs) associated with the sites. The US Environmental Protection Agency (EPA) promulgated standards for the UMTRCA that contained measures to control the contaminated materials and to protect the ground water from further degradation. The sites contain concrete foundations of mill buildings, tailings piles, and areas contaminated by windblown and waterborne radioactive tailings materials. The proposed action is to remediate the UC and NC sites by removing all contaminated materials within the designated site boundaries or otherwise associated with the sites, and relocating them to, and stabilizing them at, a location approximately 5 road mi (8 km) northeast of the processing sites on land administered by the US Bureau of Land Management (BLM). Remediation would be performed by the DOE's Uranium Mill Tailings Remedial Action (UMTRA) Project

  15. Treatment of uranium mining and milling wastewater using biological adsorbents

    Selected samples of waste microbial biomass originating from various industrial fermentation processes and biological treatment plants have been screened for biosorbent properties in conjunction with uranium, thorium and radium in aqueous solutions. Biosorption isotherms were used for the evaluation of biosorptive uptake capacity of the biomass. The biomass was also compared to synthetic adsorbents such as activated carbon. Determined uranium, thorium and radium biosorption isotherms were independent of the initial solution concentrations. Solution pH affected uptake. Rhizopus arrhizus at pH 4 exhibited the highest uranium and thorium biosorptive uptake capacity in excess of 180 Mg/g. It removed about 2.5 and 3.3 times more uranium than the ion exchange resin and activated carbon tested. Penicillium chrysogenum adsorbed 50000 pCi/g radium at pH 7 and at an equilibrium radium concentration of 1000 pCi/L. The most effective biomass types studied exhibited removals in excess of 99% of the radium in solution

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

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

  17. Studies of bentonite and red soils as capping of the uranium mill tailing impoundments

    In this study, a conceptual model for the remediation of uranium mill tailing in south China is developed. Multiple-layer capping employing bentonite and local red soils at the Erqier and Shangrao uranium mill tailings impoundments were tested and the efficiency and cost of applying different capping materials were studied. These studies included determinations of the mineral composition and sedimentology of prospective capping materials, in situ radon and gamma surveys, measurement of infiltrating of the precipitation, as well as nuclide analyses in vegetation and local red soils. The in situ gamma surveys showed that all three capping structure tested satisfy the national regulations with regard to gamma radiation. In general, capping material with high content of clay minerals can effectively prevent radon from escaping to the surrounding atmosphere due to clays' high adsorption of radon. The radon concentrations with thinner capping are higher than those with thicker capping. Vegetation on the cover surface is one of the important measures to achieve long-term stabilisation and isolation of uranium mill tailings. In South China, vegetation can play an active role to prevent erosion due to high precipitation, and to keep the remedied tailings matching to the character of the surrounding landscape. Nuclide concentrations in grasses were analysed in order to check whether the nuclides migrate from the mill tailings. Higher concentrations of U, Th and Ra were observed in grass growing on the mill tailings than in the surrounding environment. However, the nuclide concentrations are not elevated compared to the statistical nuclide concentration in soils in that province. This suggests that no significant migration of nuclides from the uranium mill tailings to the environment was observed in this study. The lower content of 40 K in grass growing on the capping was unexpected. Some shallow borehole sampling under uranium impoundments at Erqier site was conducted

  18. Assessment of the radiological impact of the inactive uranium-mill tailings at Grand Junction, Colorado

    Results of a radiological survey of the inactive uranium-mill site at Grand Junction, Colorado, made in May and June 1976, are presented along with descriptions of techniques and equipment used to obtain the data and an assessment of increased risk of health effects attributable to radiation and radionuclides from the tailings. An estimate of potential health effects of exposure to gamma rays around a former mill building and to radon daughters produced by radon dispersed from the tailings has been made for occupants of the site

  19. Environmental restoration in regions of uranium mining and milling in Ukraine: Progress, problems and perspectives

    Uranium exploration activities in Ukraine were initiated in 1946. So far 21 uranium reserves have been identified in the Southern regions of Ukraine. Industrial scale mining has been undertaken in two main areas -ZhovtiVody (Dnipropetrovsk region) and more recently - near the city of Kirovograd. Uranium milling capabilities were created in ZhovtiVody and Dniprodzerzhinsk. At Dniprodzerzhinsk Prydniprovsky Chemical Plant uranium milling started in the late 40's, initially using ores from the countries of Central Europe. Lack of relevant environmental standards and appropriate technologies for uranium extraction contributed to contamination of both industrial and residential areas. As a result, about 1340 ha of industrial areas were contaminated and ecologically affected. Extensive utilization of waste rock pile for road and building construction in the 50's and 60's resulted in contamination of residential areas in the region. To provide a comprehensive solution to the radioecological problems of the ZhovtiVody area a State Programme of Actions up to the year 2005 was adopted by the Ukrainian government in 1995. A timely methodological and information support for national activities on environmental restoration in Ukraine was provided by IAEA regional project RER/9/022. In April 1996 under the framework of the RER/9/022 project, seminar on environmental restoration in regions of uranium mining and milling took place in the town of Zhovti Vody, that allowed involvement of local experts and organizations into the project activities directly. The proposed paper is based on the vast amount of data accumulated in Ukraine during RER/9/022 covering the period 1993-1996. Severe lack of finance adversely affected all activities within the nuclear sector, environmental restoration implementation being the most affected. In such circumstances RER/9/022 remained as one of the most valuable contributing factors in the development of regulations, guidance and practices in the

  20. Pre-operational environmental survey at the uranium mine and mill site, Pocos de Caldas, MG - Brazil

    The pre-operational environmental survey at the uranium mine and mill was carried out by the Brazilian Nuclear Energy Commission/CNEN. The results obtained are sufficient to characterize the environmental background of the area. (E.G.)

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

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

  2. Origin and subsurface migration of radionuclides from waste rock at an abandoned uranium mine near Bancroft, Ontario

    Uranium-mine waste rock dump sites may require long-term surveillance because of the potential contamination of radionuclides from waste rock to the subsurface environment. In order to assess the conditions and controls on the migration in groundwater of waste-rock-derived contaminants, an area of old waste rock of a sand aquifer at the abandoned Greyhawk uranium mine near Bancroft, Ontario, was monitored. The waste rock has been abandoned for more than two decades. The results of a four-year hydrological and radiological investigation at the Greyhawk site indicated the presence of contaminant plumes of sup(238)U, sup(234)U, sup(226)Ra, sup(210)Pb, sup(230)Th, sup(232)Th, sulphate, bicarbonate and dissolved inorganic carbon in the sand aquifer originating from the waste rock. Laboratory-determined parameters were applied in two contaminant migration models for simulating the observed frontal positions of the waste-rock-derived radionuclides in the sand aquifer and also for predicting the spread of radionuclide contamination in the future. With the possible exception of sup(238)U, reasonable results were obtained for the simulations of the sup(226)Ra, sup(210)Pb and sup(230)Th mobilities in the sand aquifer

  3. Uranium

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

  4. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    Hartley, J.N.; Koehmstedt, P.L; Esterl, D.J.; Freeman, H.D.; Buelt, J.L.; Nelson, D.A.; Elmore, M.R.

    1981-05-01

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation.

  5. Asphalt emulsion sealing of uranium mill tailings. 1980 annual report

    Studies of asphalt emulsion sealants conducted by the Pacific Northwest Laboratory have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to near background levels. Field tests at the tailings pile in Grand Junction, Colorado, confirmed that an 8-cm admix seal containing 22 wt% asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and compacted, overburden was applied over the seal to protect the seal from ultraviolet degradation

  6. Application of asphalt emulsion seals to uranium mill tailings

    Studies of asphalt emulsion sealants have demonstrated that the sealants are effective in containing radon and other potentially hazardous material within uranium tailings. The laboratory and field studies have further demonstrated that radon exhalation from uranium tailings piles can be reduced by greater than 99% to less than background levels. Field tests at the tailings pile in Grand Junction, Colorado confirmed that an 8-cm admix seal containing 22 wt % asphalt could be effectively applied with a cold-mix paver. Other techniques were successfully tested, including a soil stabilizer and a hot, rubberized asphalt seal that was applied with a distributor truck. After the seals were applied and conpacted, overburden was applied over the seal to protect the seal from ultraviolet degradation. 14 figures

  7. Tree density on a vegetated uranium mill tailings site and associated estimates of Ra-226 in above ground biomass

    The transfer of Ra-226 to the terrestrial pathway will depend on the uptake by indigenous species which colonize dry areas of inactive or abandoned uranium mill tailings sites. The density of trembling aspen and white birch, their heights and biomass values, have been determined 10 to 15 years after revegetation. In addition the percentage composition of the ground cover for herbs, shrubs and grasses is evaluated. For aspens of less than 1 m in height, the density of 0.0536 trees/m2 was considerably higher than for birches of the same height with 0.0097 trees/m2. As tree heights increase the number of trees/m2 decrease to 0.0049 and 0.0010 respectively for 3 to 4 m tall trees. Trees taller than 4 m were rarely found. The ground cover biomass (approximately 125 g/m2) consisted generally of two types; either shrubs were dominant or herbs and grasses prevailed. From Ra-226 concentrations in different above-ground biomass components and the average composition of the vegetation on one square metre, transfer values were estimated. Annual transfer by herbal biomass (leaves, herbs and grasses) ranged from 330 to 760 pCi/m2. The standing crop of woody biomass was estimated to range from 450 to 1700 pCi/m2

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

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

  9. Concepts and results in the uranium mill tailings remedial action ground water project

    The Uranium Mill Tailings Remedial Action Ground Water Project is responsible for bringing 22 former uranium millsites into compliance with ground water standards determined by the U.S. Environmental Protection Agency. These standards require that contaminants in the ground water do not cause an unacceptable risk to human health and the environment. To bring the sites into regulatory compliance, the project framework uses available provisions in the standards that allow use of three compliance strategies: No further action, passive (natural flushing) remediation, and active-engineered remediation. Strategies are evaluated on a site-specific basis, and selection is based on site characteristics and conditions. (orig.)

  10. Draft environment statement related to operation of Moab uranium mill (Grand County, Utah)

    This draft environmental impact statement was prepared by the staff of the U.S. Nuclear Regulatory Commission and issued by the Commission's Office of Nuclear Material Safety and Safeguards. The proposed action is the continuation of Source Material License SUA-917 issued to Atlas Corporation for the operation of the Atlas Uranium Mill in Grand County, Utah, near Moab (Docket No. 40-3453). This authorizes a 600-ton (450-MT) per day acid leach circuit (for recovery of vanadium as well as uranium) and a 600-ton (450-MT) per day alkaline leach circuit

  11. Environmental monitoring requirements during remedial action and stabilization of uranium mill tailings (UMTRA project)

    The Department of Energy is conducting remedial action at uranium mill sites which supplied uranium to the US government under the Manhattan Project. There are requirements to conduct an environmental monitoring program during actual remedial action. The purpose of the environmental monitoring program is to provide information and assurance to the DOE and the public that environmental releases, due to remedial action activities, are within applicable regulations and guidelines. A discussion of the generic program requirements including: radon monitoring, radionuclide particulate monitoring, water monitoring and environmental gamma dose assessment are reviewed. Specific results for the Canonsburg, PA and Shiprock, NM UMTRA sites, are briefly presented

  12. Accumulation of arsenic in Lemna gibba L. (duckweed) in tailing waters of two abandoned uranium mining sites in Saxony, Germany.

    Mkandawire, Martin; Dudel, E Gert

    2005-01-01

    Accumulation of arsenic in Lemna gibba L. was investigated in tailing waters of abandoned uranium mine sites, following the hypothesis that arsenic poses contamination risks in post uranium mining in Saxony, Germany. Consequently, macrophytes growing in mine tailing waters accumulate high amounts of arsenic, which might be advantageous for biomonitoring arsenic transfer to higher trophic levels, and for phytoremediation. Water and L. gibba sample collected from pond on tailing dumps of abandoned mine sites at Lengenfeld and Neuensalz-Mechelgrun were analysed for arsenic. Laboratory cultures in nutrient solutions modified with six arsenic and three PO(4)(3-) concentrations were conducted to gain insight into the arsenic-L. gibba interaction. Arsenic accumulation coefficients in L. gibba were 10 times as much as the background concentrations in both tailing waters and nutrient solutions. Arsenic accumulations in L. gibba increased with arsenic concentration in the milieu but they decreased with phosphorus concentration. Significant reductions in arsenic accumulation in L. gibba were observed with the addition of PO(4)(3-) at all six arsenic test concentrations in laboratory experiments. Plant samples from laboratory trials had on average twofold higher bioaccumulation coefficients than tailing water at similar arsenic concentrations. This would be attributed to strong interaction among chemical components, and competition among ions in natural aquatic environment. The results of the study indicate that L. gibba can be a preliminary bioindicator for arsenic transfer from substrate to plants and might be used to monitor the transfer of arsenic from lower to higher trophic levels in the abandoned mine sites. There is also the potential of using L. gibba L. for arsenic phytoremediation of mine tailing waters because of its high accumulation capacity as demonstrated in this study. Transfer of arsenic contamination transported by accumulations in L. gibba carried with

  13. Po-210 distribution in uranium-mill circuits

    Greater than 99% of all incoming Po-210 reports to the tailing piles for both the acid and the alkaline leach uranium circuits. Leached Po-210 may be carried along on small particles rather than dissolved in solution. There does not appear to be any radiologically significant buildup or accumulation in the acid leach circuit, but there are noteworthy amounts in the molybdenum recovery solution

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

    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.

  15. Research and development of measures to be taken for long term stabilization and isolation of uranium mill tailings

    The U.S. Department of Energy has taken a holistic approach to the remediation of uranium mill tailings and contaminated groundwater at the Title I sites designated in the Uranium Mill Tailings Radiation Control Act. This approach is suggested as guidance for the characterization and remediation of other sites with contamination, depending on site-specific or country-specific conditions. This paper describes the process using certain specific examples. (author)

  16. Assessment on the environment impact of mining and milling process of an uranium deposit in north China

    The main radioactive pollution sources were analyzed comprehensively during the mining and milling process of an uranium deposit in North China, the possible radioactive environmental impact from these source was evaluated and predicted. The paper also analyzed the non-radioactive environmental impact from the mining and milling, and presented the main evaluation conclusion. Some useful measures of radioactive protection and environmental reservation were proposed for the efforts of uranium deposit mining. (authors)

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

    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

  18. Radioecological investigations of uranium mill tailings systems: Final report for the period September 1, 1979 through April 30, 1987

    This document is the final report on studies of the integrity and transport of uranium and radioactive progeny in active and reclaimed uranium mill tailings. The overall program was designed to provide basic information on the radioecology of 238U, 230Th, 226Ra, 210Pb and 210Po, responses of plants and animals to the landscape disruptions associated with uranium production, and guidance for impact analysis, mitigation and regulation of the uranium industry. The studies reported were conducted at the Shirley Basin Uranium Mine, which is operated by the Pathfinder Mines Corporation. The mine/mill operation, located in southeastern Wyoming, is typical in terms of the ore body, mill process, and ecological setting of many uranium production centers in the western United States. The research was motivated originally by the general lack of knowledge on the transport of uranium and its radioactive daughter products through the environment, particularly through food chains in the immediate environs of uranium production operations. The work was also motivated by the relatively high contribution of uranium mining and milling to the radiation exposure of the general population from the nuclear fuel cycle

  19. Development of uranium milling and conversion at Ningyo-toge Works

    In the Ningyo-toge Works of Power Reactor and Nuclear Fuel Development Corporation (PNC), technology development has proceeded on the series processes of uranium milling and conversion from uranium ore to uranium hexafluoride. The PNC process comprises the amine extraction of ore leach solution, the subsequent contact of the uranium-containing organic solvet with hydrochloric acid to convert uranyl sulfate complex anions to urayl chloride complex anions, and back extraction with water. The Uranium tetrafluoride anhydride produced by the wet method called PNC process is excellent in the handling and reaction for uranium hexafluoride conversion. From the results so far, a demonstration type plant is now being constructed. The following matters are described: review of uranium refining and the features of PNC process, heap leaching/ion exchange/solvent extraction, electrolytic reduction, the UF4.nH2O powder production by fluoride precipitation; UF*4sub(.n h)2O dehydration, and UF*4sub(/ u f)6** conversion. (J.P.N.)

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

    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.

  1. Asphalt emulsion radon barrier systems for uranium mill tailings: an overview of the technology

    Baker, E.G.; Hartley, J.N.; Freeman, H.D.; Gates, T.E.; Nelson, D.A.; Dunning, R.L.

    1984-03-01

    Pacific Northwest Laboratory (PNL), under contract to the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field tested at Grand Junction, Colorado. Results from laboratory and field tests indicate that this system is effective in reducing radon release to near-background levels (<2.5 pCi m/sup -2/s/sup -1/) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and analysis indicates that asphalt emulsion covers are cost-competitive with other cover systems. This report summarizes the technology for asphalt emulsion radon barrier systems. 59 references, 45 figures, 36 tables.

  2. Revegetation and rock cover for stabilization of inactive uranium mill tailings disposal sites. Final report

    Beedlow, P.A.

    1984-05-01

    Guidelines for using vegetation and rock to protect inactive uranium mill tailings from erosion were developed by Pacific Northwest Laboratory as part of the Department of Energy's Uranium Mill Tailings Remedial Action Project (UMTRAP) Technology Development program. Information on soils, climate, and vegetation were collected for 20 inactive tailings sites in the western United States. Sites were grouped according to similarities in climate and vegetation. Soil loss for those sites was characterized using the Universal Soil Loss Equation. Test plots were used to evaluate (1) the interaction between vegetation and sealant barrier systems and (2) the effects of surface rock on soil water and vegetation. Lysimeter and simulation studies were used to direct and support field experiments. 49 references, 17 figures, 16 tables.

  3. Asphalt emulsion radon barrier systems for uranium mill tailings: an overview of the technology

    Pacific Northwest Laboratory (PNL), under contract to the US Department of Energy (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP) office, has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field tested at Grand Junction, Colorado. Results from laboratory and field tests indicate that this system is effective in reducing radon release to near-background levels (-2s-1) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and analysis indicates that asphalt emulsion covers are cost-competitive with other cover systems. This report summarizes the technology for asphalt emulsion radon barrier systems. 59 references, 45 figures, 36 tables

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

    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

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

    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

  6. Environmental assessment of remedial action at the Slick Rock uranium mill tailings sites Slick Rock, Colorado

    The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA) authorized the US Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miguel County. The purpose of the cleanup is to reduce the potential health effects associated with the radioactive materials remaining on the sites and on vicinity properties (VP) associated with the sites. The US Environmental Protection Agency (EPA) promulgated standards for the UMTRCA that contained measures to control the contaminated materials and to protect the groundwater from further degradation. Remedial actions at the Slick Rock sites must be performed in accordance with these standards and with the concurrence of the US Nuclear Regulatory Commission (NRC)

  7. Revegetation and rock cover for stabilization of inactive uranium mill tailings disposal sites. Final report

    Guidelines for using vegetation and rock to protect inactive uranium mill tailings from erosion were developed by Pacific Northwest Laboratory as part of the Department of Energy's Uranium Mill Tailings Remedial Action Project (UMTRAP) Technology Development program. Information on soils, climate, and vegetation were collected for 20 inactive tailings sites in the western United States. Sites were grouped according to similarities in climate and vegetation. Soil loss for those sites was characterized using the Universal Soil Loss Equation. Test plots were used to evaluate (1) the interaction between vegetation and sealant barrier systems and (2) the effects of surface rock on soil water and vegetation. Lysimeter and simulation studies were used to direct and support field experiments. 49 references, 17 figures, 16 tables

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

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

  9. Uranium Mill Tailings remedial action project waste minimization and pollution prevention awareness program plan

    The purpose of this plan is to establish a waste minimization and pollution prevention awareness (WM/PPA) program for the U.S. Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. The program satisfies DOE requirements mandated by DOE Order 5400.1. This plan establishes planning objectives and strategies for conserving resources and reducing the quantity and toxicity of wastes and other environmental releases

  10. Manual on radiological safety in uranium and thorium mines and mills

    The manual describes the personnel radiation hazards in uranium and thorium mines and mills. Measures which should be taken in order to protect the workers are outlined. The problems of air born radioactivity, external radiation, surface contamination and radioactive waste are treated. Safety standards in relation to the above mentioned subjects are given. An outline is given for monitoring programme. Monitoring methods, control methods and means of medical control are given

  11. Evaluation of long term radiological impact on population close to remediated uranium mill tailings storages

    A methodology is elaborated in order to evaluate the long term radiological impact of remediated uranium mill tailings storage. Different scenarios are chosen and modelled to cover future evolution of the tailings storages. Radiological impact is evaluated for different population such as adults and children living in the immediate vicinity or directly on the storage, road workers or walkers on the storage. Equation and methods are detailed. (author)

  12. Environmental assessment of remedial action at the Maybell Uranium Mill Tailings Site near Maybell, Colorado

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment (Attachment 1) and a floodplain/wetlands attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service (FWS)

  13. Long-term radiological aspects of management of wastes from uranium mining and milling

    Due to the contamination of uranium mill tailings by long-lived natural radionuclides, their management presents specific radiation protection aspects in the long term. This report presents several examples of the application of the International Commission of Radiological Protection (ICRP) methodology for the optimisation of radiation protection to these types of waste. The advantages and disadvantages of such an approach are discussed and several important limitations are identified

  14. Scoping session of the programmatic environmental impact statement for the Uranium Mill Tailings Remedial Action Project

    This document is about the scoping session which was held at the Community Center in Falls City, Texas. The purpose was to obtain public comment on the Programmatic Environmental Impact Statement for the Uranium Mill Tailings Remedial Action Project (UMTRA), specifically on the ground water project. Presentations made by the manager for the entire UMTRA program, manager of the site and ground water program, comments made by two residents of Fall City are included in this document

  15. Environmental assessment of ground-water compliance activities at the Uranium Mill Tailings Site, Spook, Wyoming

    This report assesses the environmental impacts of the Uranium Mill Tailings Site at Spook, Wyoming on ground water. DOE previously characterized the site and monitoring data were collected during the surface remediation. The ground water compliance strategy is to perform no further remediation at the site since the ground water in the aquifer is neither a current nor potential source of drinking water. Under the no-action alternative, certain regulatory requirements would not be met

  16. Dutch nuclear power and the environmental implications of uranium mining and milling

    This report is aimed at furthering the understanding of some of the international impacts of Dutch nuclear power generation. It has two principle objectives: 1. To clarify the connection between nuclear power generation in the Netherlands and environmental degradation elsewhere as a result of the mining and milling of uranium. 2. To establish the relevance of this environmental degradation to the formulation of Dutch energy policy. (Auth.)

  17. Identification and radiological characterization of contaminated site in Spain. Andujar uranium mill site

    Empresa Nacional de Residuos Radioactivos, S.A. (ENRESA) is remediating an inactive uranium mill facility in the town of Andujar in the south of Spain. The Andujar plant became operational in 1959 and continued in operation until 1981. All solid waste generated during the operation of the plant are contained in a tailings pile, which covers an area of 9.4 hectares and has a total volume of about one million cubic meters. The remedial action plan proposed for Andujar mill site involved stabilizing and consolidating the uranium mill tailings and contaminated materials in place. The actual tailings pile was reshaped by flattening the sideslopes to improve stability. Tailings from sideslope flattening were relocated around the existing pile and on the top of the lower pile. Mill equipment, buildings and process facilities were dismantled and demolished and place in the tailings pile. Off-pile contaminated soils were excavated and placed on top of tailings pile in order to reduce the radon flux. The pile has been covered with a multilayer system to meet the three simultaneous demands of erosion control, infiltration and radon control. In this paper it is described the identification and radiological characterization of Andujar Uranium Mill site which was carried in three phases: During the first phase, the radioactive concentration in tailings was established, and site general parameters and potential spreading of contamination were defined. During the second phase, once stabilization in place was decided three main tasks were performed: a radon flux field test, a radionuclide migration study and radiometric study. During the third phase in order to establish the final conditions of the stabilized tailings pile and off-pile soils clean conditions after remediation works a radiometric survey was carried out. (author). 2 tabs

  18. Final programmatic environmental impact statement for the Uranium Mill Tailings Remedial Action Ground Water Project. Volume 2

    The purpose of the Uranium Mill Tailings Remedial Action (UMTRA) Ground Water Project is to eliminate, reduce, or address to acceptable levels the potential health and environmental consequences of milling activities. One of the first steps in the UMTRA Ground Water Project is the preparation of the Programmatic Environmental Impact Statement (PEIS). This report contains the comments and responses received on the draft PEIS

  19. Canadian Nuclear Safety Commission Regulation of Uranium Mines and Mills

    The Canadian Nuclear Safety Commission (CNSC) is responsible to the public as its primary stakeholder for carrying out the mandate of the Nuclear Safety Control Act (NSCA). The CNSC regulates the use of nuclear energy and materials to protect health, safety, security and the environment and to respect Canada's international commitments on the peaceful use of nuclear energy. One of the areas of control from the NSCA stipulates that no person shall mine or process uranium except in accordance with a licence issued by the CNSC. The NSCA further stipulates that the CNSC may not issue a licence unless it is of the opinion that the applicant is qualified to carry out the activity that the licence authorizes, and that in carrying out the activity, the applicant will make adequate provision for the protection of the environment, the health and safety of persons, the maintenance of national security and measures to implement international obligations to which Canada has agreed. In order to safely manage the uranium mine facility and monitor compliance with regulatory requirements, the CNSC: 1) sets and documents clear requirements, using a process that includes public consultation; 2) verifies that the operator's processes and programmes satisfy regulatory requirements; 3) provides stakeholders with the opportunity to be heard; 4) bases decisions on thorough, unbiased assessments performed by CNSC staff of objective, factual evidence; and 5) assesses the performance of licensees with respect to their protection of the environment, as well as the health and safety of persons and security. The paper will describe these activities in the context of best environmental protection practices and the CNSC licensing and compliance processes for existing, new or historical legacy uranium mine facilities. (author)

  20. UMTRAP research on cover design for uranium mill tailings

    As a result of the UMTRAP research on radon attenuation and tailings cover design, the basis and general procedures are available for designing covers for uranium tailings piles to meet present criteria for radon emissions. The general procedures involve assessment of the radon source strength of the tailings, definition of candidate cover materials, assessment of their moisture retention and radon diffusion properties, computing the required thicknesses of these materials, comparing costs, and evaluating long-term performance criteria. Final selection of the cover design must assure adequate long-term performance and radon retention as first priority, and keep costs to a minimum in achieving this goal

  1. Radiological survey of the inactive uranium-mill tailings at Rifle, Colorado

    Results of radiological surveys of two inactive uranium-mill sites near Rifle, Colorado, in May 1976 are presented. These sites are referred to as Old Rifle and New Rifle. The calculated 226Ra inventory of the latter site is much higher than at the older mill location. Data on above-ground measurements of gamma exposure rates, surface and near-surface concentration of 226Ra in soil and sediment samples, concentration of 226Ra in water, calculated subsurface distribution of 226Ra, and particulate radionuclide concentrations in air samples are given. The data serve to define the extent of contamination in the vicinity of the mill sites and their immediate surrounding areas with tailings particles. Results of these measurements were utilized as technical input for an engineering assessment of these two sites

  2. Benefit-cost aspects of long-term isolation of uranium mill tailings

    The Uranium Mill Tailings Radiation Control Act of 1978 provides for regulations for control of radon diffusion from uranium mill tailings to protect the public welfare. In developing these regulations, the Office of Nuclear Material Safety and Safeguards of the Nuclear Regulatory Commission has sought to establish the benefits and costs for alternative regulatory criteria. This report provides a perspective on some economic issues associated with long-term radiation effects from disposal of uranium mill tailings. The general problem of developing an economic rationale for regulating this activity is complicated by the very long-term and widespread effects which could result from radon gas diffusion associated with tailings piles. The economic issues are also complex because of the trade-offs between costs of disposal and intangible social values. When intergenerational implications were considered the traditional basis for discounting in a benefit-cost framework was found to shift. The appropriate rate of discount was found to depend on ethical assumptions and expectations about the relative welfare of future generations. 30 references, 1 figure, 2 tables

  3. Critical management issues for the Uranium Mill Tailings Remedial Action (UMTRA) Project

    The Uranium Mill Tailings Radiation Control Act of 1978 (PL95-604) authorized the Secretary of Energy to enter into cooperative agreements with certain states and Indian Tribes to clean up 24 inactive uranium mill tailing sites and associated vicinity properties. The Uranium Mill Tailings Remedial Action (UMTRA) Project includes the three Federal agencies (EPA, DOE, and NRC), eleven state, Indian Tribes, and at least four major contractors. The UMTRA Project extends over a period of ten years. The standards for the Project require a design life of 1000 years with a minimum performance period of 200 years. This paper discusses the critical management issues in dealing with the UMTRA Project and identifies the development of solutions for many of those issues. The highlights to date are promulgation of EPA standards, continued support from Congress and participating states and Indian Tribes, significant leadership shown at all levels, establishment of credibility with the public, and continued motivation of the team. The challenge for tomorrow is making certain NRC will license the sites and maintaining the high level of coordination exhibited to date to assure Project completion on schedule

  4. Testing and inspection of remedial actions at inactive uranium mill tailing sites

    DOE is responsible for planning and conducting remedial actions for stabilization of inactive uranium mill tailings in accordance with EPA standards. The options presently being considered and implemented by the DOE for stabilization of the inactive tailings consists of (i) stabilization of tailings in place, (ii) stabilization on site, and (iii) relocation and stabilization of tailings at another location. The detailed design and construction procedure for each remedial action depends upon the site-specific plan selected by the DOE. Title I of the Uranium Mill Tailings Radiation Control Act of 1978, as amended (UMTRCA) requires Nuclear Regulatory Commission (NRC) concurrence in DOE's selection and performance of remedial actions at inactive uranium mill tailings sites. Among the specific technical aspects of the remedial action performance is field control, including testing and inspection. The paper identifies remedial action inspection plan features related to geotechnical engineering that may be necessary to control, verify, and document the DOE's remedial action activities. Basically, the extent of inspection and testing should be sufficient to provide adequate quality control, to satisfy requirements of plans and specifications, and to furnish the necessary permanent record. Also, it is essential that the personnel performing the inspection and testing have the required training and experience to perform a professional job

  5. Environmental factors affecting long-term stabilization of radon suppression covers for uranium mill tailings

    Young, J.K.; Long, L.W.; Reis, J.W.

    1982-04-01

    Pacific Northwest Laboratory is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon suppression cover applied to uranium mill tailings. To help determine design stresses for the tailings piles, environmental parameters are characterized for the five active uranium-producing regions on a site-specific basis. Only conventional uranium mills that are currently operating or that are scheduled to open in the mid 1980s are considered. Available data indicate that flooding has the most potential for disrupting a tailings pile. The arid regions of the Wyoming Basins and the Colorado Plateau are subject to brief storms of high intensity. The Texas Gulf Coast has the highest potential for extreme precipitation from hurricane-related storms. Wind data indicate average wind speeds from 3 to 6 m/sec for the sites, but extremes of 40 m/sec can be expected. Tornado risks range from low to moderate. The Colorado Plateau has the highest seismic potential, with maximum acceleration caused by earthquakes ranging from 0.2 to 0.4 g. Any direct effect from volcanic eruption is negligible, as all mills are located 90 km or more from an igneous or hydrothermal system.

  6. Environmental factors affecting long-term stabilization of radon suppression covers for uranium mill tailings

    Pacific Northwest Laboratory is investigating the use of a rock armoring blanket (riprap) to mitigate wind and water erosion of an earthen radon suppression cover applied to uranium mill tailings. To help determine design stresses for the tailings piles, environmental parameters are characterized for the five active uranium-producing regions on a site-specific basis. Only conventional uranium mills that are currently operating or that are scheduled to open in the mid 1980s are considered. Available data indicate that flooding has the most potential for disrupting a tailings pile. The arid regions of the Wyoming Basins and the Colorado Plateau are subject to brief storms of high intensity. The Texas Gulf Coast has the highest potential for extreme precipitation from hurricane-related storms. Wind data indicate average wind speeds from 3 to 6 m/sec for the sites, but extremes of 40 m/sec can be expected. Tornado risks range from low to moderate. The Colorado Plateau has the highest seismic potential, with maximum acceleration caused by earthquakes ranging from 0.2 to 0.4 g. Any direct effect from volcanic eruption is negligible, as all mills are located 90 km or more from an igneous or hydrothermal system

  7. Converting the Caetite mill process to enhance uranium recovery and expand production

    Full text: The Caetite uranium mill, located in Caetite - Bahia - Brazil, was commissioned in 2000 to produce about 880 000 pounds of uranium oxide per year from an uranium ore averaging 0.29% U3O8. The milling process starts with ore crushing followed by heap leaching with sulfuric acid solution to generate a pregnant leaching solution (PLS) containing about 2.5 g U3O8/L. Uranium separation and purification is carried out by solvent extraction with a kerosene solution of tertiary amine followed by stripping with an acidified sodium chloride aqueous solution. Uranium is precipitated as ammonium diuranate that is washed, filtered and dried. The historical average uranium recovery from this process is about 76%. As the Brazilian government has confirmed recently its plans to start building the third nuclear power plant in 2009, the Brazilian uranium production will have to double its capacity in the next two years. To fulfill the increasing demand, a change in the Caetite's milling process is being evaluated in order to not only increase the production but also the uranium recovery. In the new milling flow sheet the heap leaching process is changed to conventional tank agitated leaching of a - 0.59 mm ground ore slurry in sulfuric acid medium. Batch and pilot plant essays has shown that the uranium recovery increases to about 93% under the following conditions: grind size: -0.59 mm; slurry density: 65 solids wt%; leaching time: 4 hours; temperature: 60 deg C; oxidation potential: ∼500 mV; acid concentration in the PLS: ∼10 g/L. As the use of sodium chloride as the stripping agent has presented detrimental effects in the extraction/stripping process once all the process water is recycled, two alternative process are being evaluated for the uranium recovery from the PLS: (a) uranium peroxide precipitation at a controlled pH from a PLS that was firstly neutralized with ground limestone to pH 3.2 and filtered. Batch essays have shown good results with a final

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

    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

  9. Mortality among residents of Uravan, Colorado who lived near a uranium mill, 1936-84

    A cohort mortality study was conducted of all adult residents who ever lived in Uravan, Colorado, a company town built around a uranium mill. Vital status was determined through 2004 and standardised mortality analyses conducted for 1905 men and women alive after 1978 who lived for at least 6 months between 1936 and 1984 in Uravan. Overall, mortality from all causes (standardised mortality ratio (SMR) 0.90) and all cancers (SMR 1.00) was less than or as expected based on US mortality rates. Among the 459 residents who had worked in underground uranium mines, a significant increase in lung cancer was found (SMR 2.00; 95% CI 1.39-2.78). No significant elevation in lung cancer was seen among the 767 female residents of Uravan or the 622 uranium mill workers. No cause of death of a priori interest was significantly increased in any group, i.e. cancers of the kidney, liver, breast, lymphoma or leukaemia or non-malignant respiratory disease, renal disease or liver disease. This community cohort study revealed a significant excess of lung cancer among males who had been employed as underground miners. We attribute this excess to the historically high levels of radon in uranium mines of the Colorado Plateau, coupled with the heavy use of tobacco products. There was no evidence that environmental radiation exposures above natural background associated with the uranium mill operations increased the risk of cancer. Although the population studied was relatively small, the follow-up was long, extending up to 65 years after first residence in Uravan, and nearly half of the study subjects had died

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

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

    1980-06-01

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

  11. Uranium exploration, mining and milling proposal, Navajo Indian Reservation, New Mexico

    The Secretary of the Interior has been requested to approve an exploration permit and mining lease which are part of a uranium exploration, mining, and milling Agreement, negotiated between the Navajo Tribe and the Exxon Corporation. The exploration area is a 400,000 acre tract located on the Navajo Reservation in San Juan County, New Mexico. If uranium ore in sufficient quantities to warrant development is discovered, Exxon is authorized to take a total of 51,200 acres to lease for mining, of which only 5,120 surface acres may be used for mining and milling purposes. While all exploration and predevelopment costs prior to mining must be borne by Exxon, the Navajo Tribe has reserved the right to participate in the venture on either a royalty basis or as a partner holding up to a 40 percent working interest. Impacts resulting from exploration will include disturbance of soils and vegetation and air quality degradation resulting from the vehicular movement and the operation of drilling equipment. If mining and milling takes place significant environmental impacts include: sub-surface water depletion, soils and vegetation disturbance, air quality degradation, interruption of the wildlife habitat, population increases, increased demands on community services and facilities, and disruption of established lifestyles and social patterns. Low levels of radioactive emissions will be found at mine and mill sites. Income and employment opportunities from the project to the Navajo Tribe, Navajo people, and the entire San Juan County community will be significant

  12. Radiological survey of the inactive uranium-mill tailings at Green River, Utah

    The uranium-mill tailings at Green River, Utah, are relatively low in 226Ra content and concentration (20 Ci and 140 pCi/g, respectively) because the mill was used to upgrade the uranium ore by separating the sand and slime fractions; most of the radium was transported along with the slimes to another mill site. Spread of tailings was observed in all directions, but near-background gamma exposure rates were reached at distances of 40 to 90 m from the edge of the pile. Water erosion of the tailings is evident and, since a significant fraction of the tailings pile lies in Brown's Wash, the potential exists for repetition of the loss of a large quantity of tailings such as occurred during a flood in 1959. In general, the level of surface contamination was low at this site, but some areas in the mill site, which were being used for nonuranium work, have gamma-ray exposure rates up to 143 μR/hr

  13. 40 CFR 23.8 - Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978.

    2010-07-01

    ... 40 Protection of Environment 1 2010-07-01 2010-07-01 false Timing of Administrator's action under Uranium Mill Tailings Radiation Control Act of 1978. 23.8 Section 23.8 Protection of Environment ENVIRONMENTAL PROTECTION AGENCY GENERAL JUDICIAL REVIEW UNDER EPA-ADMINISTERED STATUTES § 23.8 Timing of Administrator's action under Uranium...

  14. Derived surface contamination limits for the uranium mining and milling industry

    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 105 Bq/m2 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 104 Bq/m2 of beta activity is proposed for the release of non-porous materials and equipment with no detectable loose contamination to the public domain

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

    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

  16. Radionuclides distribution, properties, and microbial diversity of soils in uranium mill tailings from southeastern China

    Objective: To collect the radioactive contamination data for environmental rehabilitation in uranium mill tailings in southeastern China. Method: The sample areas were divided into high, moderate and low concentration areas, according to the uranium concentration. For every area, 3 soil samples were collected at 0–15 cm, 15–30 cm and 30–45 cm depth respectively, with 5 repetitions for each. Total 45 (3 × 5 × 3) soil samples were collected. Physicochemical properties and enzyme activities of soils were determined as described by references. The concentrations of the radionuclides 238U, 232Th, 226Ra and 40K in soils were determined by using HPGe gamma-ray spectrometer. Soil microbial diversity was analyzed via denaturing gradient gel electrophoresis (DGGE). Results: Soil samples were all acidic. Physicochemical properties, like pH, content of total/available N, P and K, as well as enzyme activities were all increased along with decreased uranium concentration. The 232Th concentration was increased with the decreased uranium concentration and was not influenced by the depth of sample sites. However, uranium concentration and depth of sample showed no significant influence on the concentrations of 226Ra and 40K. The concentration of 232Th was significantly correlated with that of 226Ra and 40K, while the concentrations of 226Ra and 40K were significantly correlated. However, Pearson correlation coefficients between 238U and other radionuclides were not significant. The microbial population in different concentration areas was different with four domain strains in low area, and two for both moderate and high areas. Furthermore, in each sample site, Proteobacteria was the most dominant flora, while environmental samples were the second according to GenBank database. Moreover, Serratia sp. of Proteobacteria was the dominant strain. Conclusion: Radionuclides distribution in the uranium mill tailing showed a profound influence on soil properties and microbial

  17. Background report for the uranium-mill-tailings-sites remedial-action program

    The Uranium Mill Tailings Radiation Control Act of 1978, Public Law 95-604, mandates remedial action responsibilities to the Department of Energy for designated inactive uranium processing sites. To comply with the mandates of the Act, a program to survey and evaluate the radiological conditions at inactive uranium processing sites and at vicinity properties containing residual radioactive material derived from the sites is being conducted; the Remedial Action Program Office, Office of the Assistant Secretary for Nuclear Energy is implementing remedial actions at these processing sites. This report provides a brief history of the program, a description of the scope of the program, and a set of site-specific summaries for the 22 locations specified in the Act and three additional locations designated in response to Federal Register notices issued on August 17 and September 5, 1979. It is designed to be a quick source of background information on sites covered by the implementation program for Public Law 95-604

  18. Retention of radioactive wastes at an operating uranium mill site

    A uranium mine in Eastern Ontario, Canada has recently reopened in a predominantly tourist recreation area sensitive to hazardous waste emissions. The tailings and waste water from the mine are ponded in a bedrock basin filled with deep glacial outwash sands and gravels (alluvium) at one end. The ponded tailings water is treated with barium chloride, passed through a concrete settling basin and discharged into the alluvium. However, some tailings water and precipitation seeps through the tailings into the underlying deep alluvium carrying dissolved Ra 226 into a nearby lake. This seepage is being controlled by a grout curtain constructed of a slurry of clay, bentonite and cement injected into the alluvium to the bedrock surface

  19. Decommissioning costs and financial assurances for uranium mines and mills in Canada

    'Full text:' The Athabasca Basin region of northern Saskatchewan is now the location of all uranium production in Canada. About one-third of world primary production originates from the region with seven projects, as follows, currently licensed by the Canadian Nuclear Safety Commission (CNSC) and by Saskatchewan Environment (SE): Rabbit Lake - underground and (formerly) open pit mining, mill, tailings management facilities - operating. Cluff Lake - underground and open pit mining, mill, tailings management facility - decommissioning (operations ceased in 2002). Key Lake - (formerly) open pit mining, mill, tailings management facilities - operating (ore from McArthur River). McClean Lake - open pit mining, mill, tailings management facility - operating. McArthur River - underground mine (ore to Key Lake) - operating. Cigar lake - underground mine - construction - Midwest - future mine development - site preparation licence. Preliminary decommissioning plans, and financial guarantees for future decommissioning, are a requirement of each licence. The Elliot Lake area of Canada has also had extensive uranium mining and milling activities, with the last operating mine closing in 1996. Decommissioning has been completed by the licensees, however monitoring, care and maintenance of the sites is ongoing. This leads to a reduced, but ongoing, requirement for financial guarantees. Decommissioning objectives for a uranium mine and mill site must consider that the waste rock and tailings resulting from the operation, as well as the majority of the waste materials resulting from removing the physical facilities, will be managed on site for the long term. This is a fundamental difference from many other types of nuclear facilities, where all of the physical facilities, and the wastes which have been produced during operations, are removed and disposed elsewhere. Other factors which differ from many other nuclear facilities are the remote location, and the need for an extended

  20. Current practices for the management and confinement of uranium mill tailings

    This report discusses the current practices used in the design siting, construction and closeout of impoundment facilities for uranium mill tailings. The objective is to present an integrated overview of the technological, safety and radiation protection aspects of these topics in order to ensure that the potential radiological and non-radiological risks associated with the management of uranium mill tailings are minimized now and in the future. The report: identifies the nature and source of radioactive and non-radioactive pollutants in uranium mill tailings; identifies the important mechanisms by which pollutants can be released from the tailings impoundment; reviews radiation protection aspects of these mechanisms; describes the pathways by which the pollutants may reach humans; describes some of the site selection and design options and considerations for final stabilization and rehabilitation of tailings impoundments; describes the methods of assessing closure strategies; describes long term responsibilities for tailings management and financial assurance to ensure these responsibilities; and reviews the magnitude and probability of occurrence of the hazards arising, with the aim of ensuring that the risks presented are acceptable. Because of the complexity of the pollutant release mechanisms and the site specific nature of the design and management controls that can be used, it is not possible for a report of this nature to be either exhaustive or detailed in all respects. The methods of confinement employed for any particular tailings impoundment will depend on the country, its climate, demography and its site specific performance criteria which should be defined by the relevant competent authorities. Both operating and post-operating conditions are considered. After shutdown of the mill and stabilization of the tailings, continuing surveillance and maintenance should be considered until the integrity and durability of the tailings impoundment have been

  1. Conclusions and recommendations of the SCOPE-RADSITE workshop on remediation achievements after uranium mining and milling

    The SCOPE-RADSITE Project provides a unique international scientific forum where the radioactive wastes generated in the development of nuclear weapons, including their potential impact on the environment and human populations, are studied and reviewed. At the present SCOPE-RADSITE workshop a team of experts presented the current status of uranium mining and milling operations in the United States, in the former Soviet Union (FSU) and in Central and Eastern Europe. The effect of radiocontaminants resulting from the uranium mining and milling operations to species other than humans and the combined effects of environmental radiation and other agents were discussed. Finally, three cases of remediation projects were presented: remediation at COGEMA sites in France, the WISMUT rehabilitation project in Germany and uranium mine reclamation in Texas and remediation achievements were described. Finally the workshop discussed important issues and recommendations to be considered when approaching remediation of past legacies resulting from uranium mining and milling. (author)

  2. The U.S. Uranium Mill Tailings Radiation Control Act -- An environmental legacy of the Cold War

    The US Department of Energy (DOE) has guided the Uranium Mill Tailings Remedial Action (UMTRA) Project through its first 10 years of successful remediation. The Uranium Mill Tailings Radiation Control Act (UMTRCA), passed in 1978, identified 24 uranium mill tailings sites in need of remediation to protect human health and the environment from the residual contamination resulting from the processing of uranium ore. The UMTRCA was promulgated in two titles: Title 1 and Title 2. This paper describes the regulatory structure, required documentation, and some of the technical approaches used to meet the Act's requirements for managing and executing the $1.4 billion project under Title 1. Remedial actions undertaken by private industry under Title 2 of the Act are not addressed in this paper. Some of the lessons learned over the course of the project's history are presented so that other countries conducting similar remedial action activities may benefit

  3. Engineering assessment of inactive uranium mill tailings: Mexican Hat Site, Mexican Hat, Utah

    Ford, Bacon and Davis Utah Inc. has reevaluated the Mexican Hat site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Mexican Hat, Utah. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.2 million tons of tailings at the Mexican Hat site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $15,200,000 for stabilization in place, to about $45,500,000 for disposal at a distance of about 16 mi. Three principal alternatives for the reprocessing of the Mexican Hat tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $115/lb of U3O8 whether by heap leach or conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Mexican Hat tailings for uranium recovery is not economically attractive under present conditions

  4. Engineering assessment of inactive uranium mill tailings: Slick Rock sites, Slick Rock, Colorado

    None

    1981-09-01

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Slick Rock sites in order to revise the October 1977 engineering radioactive uranium mill tailings at Slick Rock, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 387,000 tons of tailings at the Slick Rock sites constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material, consolidation of the piles, and removal of the tailings to remote disposal sites and decontamination of the tailings sites. Cost estimates for the five options range from about $6,800,000 for stabilization in-place, to about $11,000,000 for disposal at a distance of about 6.5 mi. Three principal alternatives for the reprocessing of the Slick Rock tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be over $800/lb of U/sub 3/O/sub 8/ whether by conventional or heap leach plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present, nor for the foreseeable future.

  5. Engineering assessment of inactive uranium mill tailings, Shiprock site, Shiprock, New Mexico

    Ford, Bacon and Davis Utah Inc. has reevaluated the Shiprock site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Shiprock, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.5 million dry tons of tailings at the Shiprock site constitutes the most significant environental impact, although windblown tailings and external gamma radiation also are factors. The eight alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $13,400,000 for stabilization in place to about $37,900,000 for disposal at a distance of about 16 miles. Three principal alternatives for the reprocessing of the Shiprock tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $230/lb by heap leach and $250/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive

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

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

  7. Summary of the engineering assessment of inactive uranium mill tailings, Shiprock Site, Shiprock, New Mexico

    Ford, Bacon and Davis Utah Inc. has reevaluated the Shiprock site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Shiprock, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.5 million dry tons of tailings at the Shiprock site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The eight alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of the stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $13,400,000 for stabilization in place to about $37,900,000 for disposal at a distance of about 16 miles. Three principal alternatives for the reprocessing of the Shiprock tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and(c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $230/lb by heap leach and $250/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive

  8. Engineering assessment of inactive uranium mill tailings: Mexican Hat Site, Mexican Hat, Utah

    None

    1981-09-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Mexican Hat site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Mexican Hat, Utah. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.2 million tons of tailings at the Mexican Hat site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $15,200,000 for stabilization in place, to about $45,500,000 for disposal at a distance of about 16 mi. Three principal alternatives for the reprocessing of the Mexican Hat tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $115/lb of U/sub 3/O/sub 8/ whether by heap leach or conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Reprocessing the Mexican Hat tailings for uranium recovery is not economically attractive under present conditions.

  9. Engineering assessment of inactive uranium mill tailings, Shiprock site, Shiprock, New Mexico

    1981-07-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Shiprock site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Shiprock, New Mexico. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.5 million dry tons of tailings at the Shiprock site constitutes the most significant environental impact, although windblown tailings and external gamma radiation also are factors. The eight alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through VIII). Cost estimates for the eight options range from about $13,400,000 for stabilization in place to about $37,900,000 for disposal at a distance of about 16 miles. Three principal alternatives for the reprocessing of the Shiprock tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $230/lb by heap leach and $250/lb by conventional plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive.

  10. Engineering assessment of inactive uranium mill tailings: Maybell Site, Maybell, Colorado

    None

    1981-09-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Maybell site in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Maybell, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.6 million dry tons of tailings at the Maybell site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The two alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to disposal of the tailings in a nearby open pit mine and decontamination of the tailings site (Option II). Cost estimates for the two options are about $11,700,000 for stabilization in-place and about $22,700,000 for disposal within a distance of 2 mi. Three principal alternatives for the reprocessing of the Maybell tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $125 and $165/lb of U/sub 3/O/sub 8/ by heap leach and conventional plant processes, respectively. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present.

  11. Summary of the engineering assessment of inactive uranium mill tailings: Slick Rock sites, Slick Rock, Colorado

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Slick Rock sites in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Slick Rock, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 387,000 tons of tailings at the Slick Rock sites constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material, consolidation of the piles, and removal of the tailings to remote disposal sites and decontamination of the tailings sites. Cost estimates for the five options range from about $6,800,000 for stabilization in-place, to about $11,000,000 for disposal at a distance of about 6.5 mi. Three principal alternatives for the reprocessing of the Slick Rock tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be over $800/lb of U3O8 whether by conventional or heap leach plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present, nor for the foreseeable future

  12. Engineering assessment of inactive uranium mill tailings: Slick Rock sites, Slick Rock, Colorado

    Ford, Bacon and Davis Utah, Inc., has reevaluated the Slick Rock sites in order to revise the October 1977 engineering radioactive uranium mill tailings at Slick Rock, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 387,000 tons of tailings at the Slick Rock sites constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The five alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material, consolidation of the piles, and removal of the tailings to remote disposal sites and decontamination of the tailings sites. Cost estimates for the five options range from about $6,800,000 for stabilization in-place, to about $11,000,000 for disposal at a distance of about 6.5 mi. Three principal alternatives for the reprocessing of the Slick Rock tailings were examined: heap leaching; treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be over $800/lb of U3O8 whether by conventional or heap leach plant processes. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present, nor for the foreseeable future

  13. Draft programmatic environmental impact statement for the Uranium Mill Tailings Remedial Action Ground Water Project

    The US Department of Energy (DOE) is responsible for performing remedial action to bring surface and ground water contaminant levels at 24 inactive uranium processing sites into compliance with the US Environmental Protection Agency (EPA) standards. DOE is accomplishing this through the Uranium Mill Tailings Remedial Action (UMTRA) Surface and Ground Water Projects. Remedial action will be conducted with the concurrence of the US Nuclear Regulatory Commission (NRC) and the full participation of affected states and Indian tribes. Uranium processing activities at most of 24 the inactive mill sites resulted in the contamination of ground water beneath and, in some cases, downgradient of the sites. This contaminated ground water often has elevated levels of constituents such as uranium and nitrate. The purpose of the UMTRA Ground Water Project is to eliminate, or reduce to acceptable levels, the potential health and the environmental consequences of milling activities by meeting the EPA standards in areas where ground water has been contaminated. The first step in the UMTRA Ground Water Project is the preparation of this programmatic environmental impact statement (PEIS). This document analyzes potential impacts of four programmatic alternatives, including the proposed action. The alternatives do not address site-specific ground water compliance strategies. Rather, the PEIS is a planning document that provides a framework for conducting the Ground Water Project; assesses the potential programmatic impacts of conducting the Ground Water Project; provides a method for determining the site-specific ground water compliance strategies; and provides data and information that can be used to prepare site-specific environmental impacts analyses more efficiently

  14. Engineering assessment of inactive uranium mill tailings: Maybell Site, Maybell, Colorado. Summary

    Ford, Bacon and Davis Utah Inc. has reevaluated the Maybell site in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Maybell, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.6 million dry tons of tailings at the Maybell site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The two alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to disposal of the tailings in a nearby open pit mine and decontamination of the tailings site (Option II). Cost estimates for the two options are about $11,700,000 for stabilization in-place and about $22,700,000 for disposal within a distance of 2 mi. Three principal alternatives for the reprocessing of the Maybell tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $125 and $165/lb of U3O8 by heap leach and conventional plant processes, respectively. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present

  15. Engineering assessment of inactive uranium mill tailings: Maybell Site, Maybell, Colorado

    Ford, Bacon and Davis Utah Inc. has reevaluated the Maybell site in order to revise the October 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Maybell, Colorado. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.6 million dry tons of tailings at the Maybell site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The two alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to disposal of the tailings in a nearby open pit mine and decontamination of the tailings site (Option II). Cost estimates for the two options are about $11,700,000 for stabilization in-place and about $22,700,000 for disposal within a distance of 2 mi. Three principal alternatives for the reprocessing of the Maybell tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovered would be about $125 and $165/lb of U3O8 by heap leach and conventional plant processes, respectively. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery is not economically attractive at present

  16. Sequential extraction of uranium metal contamination

    Samples of uranium contaminated dirt collected from the dirt floor of an abandoned metal rolling mill were analyzed for uranium using a sequential extraction protocol involving a series of five increasingly aggressive solvents. The quantity of uranium extracted from the contaminated dirt by each reagent can aid in predicting the fate and transport of the uranium contamination in the environment. Uranium was separated from each fraction using anion exchange, electrodeposition and analyzed by alpha spectroscopy analysis. Results demonstrate that approximately 77 % of the uranium was extracted using NH4Ac in 25 % acetic acid. (author)

  17. Asphalt-emulsion sealing of uranium-mill tailings

    The use of asphalt emulsion to contain radon and radium in uranium tailings is being investigated at the Pacific Northwest Laboratory. Results of these studies indicate that a radon flux reduction of greater than 99% can be obtained using either a poured-on/sprayed-on seal (3.0 to 7.0 mm thick) or an admix seal (2.5 to 12.7 cm thick) containing about 18 wt % residual asphalt. A field test was carried out at the Grand Junction tailings pile in order to demonstrate the sealing process. A reduction in radon flux ranging from 4.5 to greater than 99% (76% average) was achieved using a 12.7-cm (5-in.) admix seal with a sprayed-on top coat. A hydrostatic stabilizer used to apply the admix was followed by compaction, which formed the radon seal. Overburden was applied to provide a protective soil layer over the seal. Included in part of the overburden was a herbicide to prevent root penetration

  18. Uranium milling and conversion at Ningyo-toge Works

    Based on these experimental results, the refining and conversion pilot plant (annual pro duction capacity 200 t-U) is now under construction, in order to promote further industrialization and to supply UF6 to the enrichment pilot plant in Ningyotoge works. The new plant has two systems of solvent extraction using tri-n-octylamine, one of which treats the pregnant liquor from the section of heap leach and ion exchange, and the other treats the uranyl sulphate solution in which yellow cake is dissolved. Both of the pregnant solvents are stripped with hydrochloric acid to obtain high grade pregnant eluates (100 g-U). Uranyl sulphate solution from the stripping circuit is reduced to uranous sulphate solution by electrolytic method. In a reduction cell, uranyl sulphate solution and dilute sulphuric acid are used respectively as catholyte and anolyte, and a cation exchange membrane is used to prevent re-oxidation of the uranous sulphate. In this case, reduction power consumption is about 1.5 kWh/kg-U and the reduction rate is over 99.5%. The uranous sulphate solution is then heated to 900C, and UF41 -- 1.2H2O (particle size of 50 -- 100 μ) is precipitated continuously with hydrofluoric acid by a new type eouipment which has made it possible to simplify the procedures of liquid-solid separation, drying and granulation. Then the crystal water in uranium tetrafluoride is dehydrated by heating to 3500C in an inert gas flow. The conversion of UF4 to UF6 is accomplished by a fluidized-bed reactor and high fluorine efficiencies over 99.9% (less than 0.1% of fluorine unreacted) is attained at about 4000C with the complete conversion of UF4 to UF6. (J.P.N.)

  19. Research on radon flux reduction from uranium mill tailings

    Radon flux reduction from tailings may be accomplished by the use of an impermeable cover to contain the radon until it decays (half life is 2.8 days). The use of a thick, relatively impermeable cover can attenuate radon flux because a large fraction of the radon would decay before it diffuses through the cover into the atmosphere. This method of reducing radon flux may require soil cover thicknesses on the order of 10 feet. In some locations, obtaining 10 feet of soil to cover 200 acres of tailings may be difficult or may lead to other significant environmental impacts. The Department of Energy is sponsoring research to identify alternatives to thick soil covers for reducing radon flux from uranium tailings to meet the forthcoming standards. The two most effective and practical materials tested thus far are Calcilox and asphalt emulsion. Currently, asphalt emulsions are being tested at the Grand Junction tailings pile in Grand Junction, Colorado, by Battelle Pacific Northwest Laboratory. Other asphalt formulations, such as foamed asphalt that requires less water than asphalt emulsions, may be practical and will be tested this year. Some sulfur-based materials and sulfur-extended asphalt also appear promising and will be tested for effectiveness in reducing radon flux. It is also important to investigate methods of applying various stabilizers to inactive tailings piles in various physical conditions of moisture content, and physical stability. Finally, since the EPA standards for remedial action at tailings piles are stated in terms of radon flux, it is important that radon flux measurements be standardized so that reliable flux measurements can be obtained and directly compared among various laboratories

  20. A top-down assessment of energy, water and land use in uranium mining, milling, and refining

    Land, water and energy use are key measures of the sustainability of uranium production into the future. As the most attractive, accessible deposits are mined out, future discoveries may prove to be significantly, perhaps unsustainably, more intensive consumers of environmental resources. A number of previous attempts have been made to provide empirical relationships connecting these environmental impact metrics to process variables such as stripping ratio and ore grade. These earlier attempts were often constrained by a lack of real world data and perform poorly when compared against data from modern operations. This paper conditions new empirical models of energy, water and land use in uranium mining, milling, and refining on contemporary data reported by operating mines. It shows that, at present, direct energy use from uranium production represents less than 1% of the electrical energy produced by the once-through fuel cycle. Projections of future energy intensity from uranium production are also possible by coupling the empirical models with estimates of uranium crustal abundance, characteristics of new discoveries, and demand. The projections show that even for the most pessimistic of scenarios considered, by 2100, the direct energy use from uranium production represents less than 3% of the electrical energy produced by the contemporary once-through fuel cycle. - Highlights: • We present environmental impacts of conventional uranium (U) mining and milling technologies. • Impacts include direct energy consumption, land use and water use. • Contemporary mine and mill data is used, updating published estimates that relied on 1970s-era data. • The direct energy used to mine and mill uranium is below 1% of the electrical energy ultimately produced by the uranium. • Even if U demand growth is strong, the direct energy return on investment of U mining and milling will remain well above 1

  1. Environmental assessment of remedial action at the Gunnison Uranium Mill Tailings Site, Gunnison, Colorado. [UMTRA Project

    Bachrach, A.; Hoopes, J.; Morycz, D. (Jacobs Engineering Group, Inc., Pasadena, CA (USA)); Bone, M.; Cox, S.; Jones, D.; Lechel, D.; Meyer, C.; Nelson, M.; Peel, R.; Portillo, R.; Rogers, L.; Taber, B.; Zelle, P. (Weston (Roy F.), Inc., Washington, DC (USA)); Rice, G. (Sergent, Hauskins and Beckwith (USA))

    1984-12-01

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Gunnison uranium of mill tailings site located 0.5 miles south of Gunnison, Colorado. The site covers 56 acres and contains 35 acres of tailings, 2 of the original mill buildings and a water tower. The Uranium Mill Tailings Radiation Control of Act of 1978 (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated (vicinity) properties off the site. The US Environmental Protection Agency promulgated standards for the remedial actions (40 CFR 192). Remedial actions must be performed in accordance with these standards and with the occurrence of the Nuclear Regulatory Commission. Four alternatives have been addressed in this document. The first alternative is to consolidate the tailings and associated contaminated soils into a recontoured pile on the southern portion of the existing site. A radon barrier of silty clay would be constructed over the pile and various erosion control measures would be taken to assure the long-term integrity of the pile. Two other alternatives which involve moving the tailings to new locations are assessed in this document. These alternatives generally involve greater short-term impacts and are more costly but would result in the tailings being stabilized in a location farther from the city of Gunnison. The no action alternative is also assessed.

  2. Derivation of release limits for a typical uranium mining and milling facility

    This report develops guidelines for calculating derived release limits (DRLs) for releases of each radionuclide belonging to the uranium-238 and thorium-232 decay chains to atmosphere, surface water and groundwater from uranium mining and milling operations in Canada. DRLs are defined as calculated limits on releases from the facility that result in radiation exposures through all environmental pathways equal to the annual effective dose equivalent limit of 0.005 Sv for stochastic effects or the annual dose equivalent limit of 0.05 Sv for non-stochastic effects in the critical group. By definition, DRLs apply to controllable radionuclide emissions which occur during the operational phase of mine/mill facilities. The report develops a steady-state environmental transfer model to determine environmental dilution and dispersion in atmosphere, surface water and groundwater between the sources at the mine and mill and the critical group receptor. Exposure pathways incorporated in the model include external exposure from immersion in the airborne plume, immersion in water, contaminated ground and contaminated shoreline sediments. Internal exposure pathways include inhalation of contaminated air and ingestion of contaminated water and terrestrial and aquatic foods

  3. Environmental assessment of remedial action at the Tuba City uranium mill tailings site, Tuba City, Arizona

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Tuba City uranium mill tailings site located approximately six miles east of Tuba City, Arizona. The site covers 105 acres and contains 25 acres of tailings and some of the original mill structures. The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated properties off the site. The US Environmental Protection Agency promulgated standards for the remedial actions (40 CFR Part 192). Remedial actions must be performed in accordance with these standards and with the concurrence of the Nuclear Regulatory Commission. The proposed action is to stabilize the tailings at their present location by consolidating the tailings and associated contaminated materials into a recontoured pile. A radon barrier would be constructed over the pile and various erosion control measures would be taken to assure the long-term stability of the pile. Another alternative which would involve moving the tailings to a new location is also assessed in this document. This alternative would generally involve greater short-term impacts and costs but would result in stabilization of the tailings at a more remote location. The no action alternative is also assessed in this document

  4. Environmental assessment of remedial action at the Tuba City uranium mill tailings site, Tuba City, Arizona

    None

    1986-11-01

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Tuba City uranium mill tailings site located approximately six miles east of Tuba City, Arizona. The site covers 105 acres and contains 25 acres of tailings and some of the original mill structures. The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated properties off the site. The US Environmental Protection Agency promulgated standards for the remedial actions (40 CFR Part 192). Remedial actions must be performed in accordance with these standards and with the concurrence of the Nuclear Regulatory Commission. The proposed action is to stabilize the tailings at their present location by consolidating the tailings and associated contaminated materials into a recontoured pile. A radon barrier would be constructed over the pile and various erosion control measures would be taken to assure the long-term stability of the pile. Another alternative which would involve moving the tailings to a new location is also assessed in this document. This alternative would generally involve greater short-term impacts and costs but would result in stabilization of the tailings at a more remote location. The no action alternative is also assessed in this document.

  5. Implementation of the Additional Protocol: Verification activities at uranium mines and mills

    Full text: The mining and milling of uranium is the first in a long chain of processes required to produce nuclear materials in a form suitable for use in nuclear weapons. Misuse of a declared uranium mining/milling facility, in the form of understatement of production, would be hard to detect with the same high level of confidence as afforded by classical safeguards on other parts of the nuclear fuel cycle. For these reasons, it would not be cost-effective to apply verification techniques based on classical safeguards concepts to a mining/milling facility in order to derive assurance of the absence of misuse. Indeed, these observations have been recognised in the Model Protocol (INFCIRC/540): 'the Agency shall not mechanistically or systematically seek to verify' information provided to it by States (Article 4.a.). Nevertheless, complementary access to uranium mining/milling sites 'on a selective basis in order to assure the absence of undeclared nuclear material and activities' (Article 4.a.(i)) is provided for. On this basis, therefore, this paper will focus predominantly on options other than site access, which are available to the Agency for deriving assurance that declared mining/milling operations are not misused. Such options entail the interpretation and analysis of information provided to the Agency including, for example, from declarations, monitoring import/export data, open source reports, commercial satellite imagery, aerial photographs, and information provided by Member States. Uranium mining techniques are diverse, and the inventories, flows and uranium assays which arise at various points in the process will vary considerably between mines, and over the operating cycle of an individual mine. Thus it is essentially impossible to infer any information, which can be used precisely to confirm, or otherwise, declared production by measuring or estimating any of those parameters at points within the mining/milling process. The task of attempting to

  6. Final environmental statement related to the Western Nuclear, Inc., Split Rock Uranium Mill (Fremont County, Wyoming)

    The proposed action is the renewal of Source Material License SUA-56 (with amendments) issued to Western Nuclear, Inc. (WNI), for the operation of the Split Rock Uranium Mill near Jeffrey City and the Green Mountain Ion-Exchange Facility, both in Fremont County, Wyoming. The license also permits possession of material from past operations at four ancillary facilities in the Gas Hills mining area - the Bullrush, Day-Loma, Frazier-Lamac, and Rox sites (Docket No. 40-1162). However, although heap leaching operations were previously authorized at Frazier-Lamac, there has never been any processing of material at this site. The Split Rock mill is an acid-leach, ion-exchange and solvent-extraction uranium-ore processing mill with a design capacity of 1540 MT (1700 tons) of ore per day. WNI has proposed by license amendment request to increase the storage capacity of the tailings ponds in order to permit the continuation of present production rates of U3O8 through 1996 using lower-grade ores

  7. Engineering assessment of inactive uranium mill tailings: Monument Valley Site, Monument Valley, Arizona

    1981-10-01

    Ford, Bacon and Davis Utah Inc. has reevalated the Monument Valley site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Monument Valley, Arizona. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposure of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.1 million tons of tailings at the Monument Valley site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through IV). Cost estimates for the four options range from about $6,600,000 for stabilization in-place, to about $15,900,000 for disposal at a distance of about 15 mi. Three principal alternatives for reprocessing the Monument Valley tailings were examined: heap leaching; Treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovery is economically unattractive.

  8. Decommissioning Canadian uranium mines and mills: regulatory framework, cleanup criteria and objectives

    The objectives of decommissioning uranium mines and mills are to remove, minimize and control potential contaminant sources, achieving an end state property that is stable and safe for humans and non-human biota over the long term. Achievement of these qualitative decommissioning objectives is defined in relation to the existing provincial and federal environmental quality objectives and, where objectives are not available, site specific benchmarks are derived. To illustrate the joint regulatory approach the paper describes the final decommissioning plans and objectives for a uranium mine and mill facility that operated for 22 years. The decommissioning activities include the reclamation of tailings, open pits, underground mines and waste rock piles, and the final disposition of all surface infrastructures, including the mill. Cleanup criteria and water quality objectives have been established for decommissioning the site, through regulatory review and public consultation, taking into account the anticipated future use of the site. Modelling and risk assessment have been performed to predict long term ecological effects and potential effects on human health. The results of all the analyses, and in particular the uncertainties in the modelling predictions, were then used to identify follow-up requirements for the project and to identify any contingency measures if the environmental monitoring indicates that the decommissioning objectives may not be achieved or that the potential environmental effects may exceed those predicted. (author)

  9. Radiological survey of the inactive uranium-mill tailings at Slick Rock, Colorado

    Results of a radiological survey of two inactive mill sites near Slick Rock, Colorado, in April 1976 are presented. One mill, referred to in this report as North Continent (NC), was operated primarily for recovery of radium and vanadium and, only briefly, uranium. The Union Carbide Corporation (UCC) mill produced a uranium concentrate for processing elsewhere and, although low-level contamination with 226Ra was widespread at this site, the concentration of this nuclide in tailings was much lower than at the NC site. The latter site also has an area with a high above-ground gamma dose rate (2700 μR/hr) and a high-surface 226Ra concentration (5800 pCi/g). This area, which is believed to have been a liquid disposal location during plant operations, is contained within a fence. A solid disposal area outside the present fence contains miscellaneous contaminated debris. The estimated concentration of 226Ra as a function of depth, based on gamma hole-logging data, is presented for 27 holes drilled at the two sites

  10. Environmental assessment of remedial action at the Slick Rock uranium mill tailings sites, Slick Rock, Colorado

    The Uranium Mill Tailings Radiation Control Act of 1978 (42 USC section 7901 et seq.), hereafter referred to as the UMTRCA, authorized the US Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miquel County. Contaminated materials cover an estimated 63 acres of the Union Carbide (UC) processing site and 15 ac of the North Continent (NC) processing site. The sites are within 1 mile of each other and are adjacent to the Dolores River. The sites contain concrete foundations of mill buildings, tailings piles, and areas contaminated by windblown and waterborne radioactive tailings materials. The total estimated volume of contaminated materials is approximately 621,300 cubic yards (yd3). In addition to the contamination in the two processing site areas, four VPs were found to contain contamination. As a result of the tailings being exposed to the environment, contamination associated with the UC and NC sites has leached into shallow ground water. Surface water has not been affected. The closest residence is approximately 0.3 air mi from either site. The proposed action is to remediate the UC and NC sites by removing all contaminated materials within the designing site boundaries or otherwise associated with the sites, and relocating them to, and stabilizing them at, a location approximately 5 road mi northeast of the sites on land administered by the Bureau of Land Management (BLM)

  11. Remedial action at the Green River uranium mill tailings site, Green River, Utah: Environmental assessment

    The inactive Green River uranium mill tailings site is one mile southeast of Green River, Utah. The existing tailings pile is within the floodplain boundaries of the 100-year and 500-year flood events. The 48-acre designated site contains eight acres of tailings, the mill yard and ore storage area, four main buildings, a water tower, and several small buildings. Dispersion of the tailings has contaminated an additional 24 acres surrounding the designated site. Elevated concentrations of molybdenum, nitrate, selenium, uranium, and gross alpha activity exceed background levels and the proposed US Environmental Protection Agency (EPA) maximum concentration limits in the groundwater in the unconsolidated alluvium and in the shallow shales and limestones beneath the alluvium at the mill tailings site. The contamination is localized beneath, and slightly downgradient of, the tailings pile. The proposed action is to relocate the tailings and associated contaminated materials to an area 600 feet south of the existing tailings pile where they would be consolidated into one, below-grade disposal cell. A radon/infiltration barrier would be constructed to cover the stabilized pile and various erosion control measures would be taken to ensure the long-term stability of the stabilized pile. 88 refs., 12 figs., 20 tabs

  12. Environmental assessment of remedial action at the Gunnison Uranium Mill Tailings Site, Gunnison, Colorado

    This document assesses and compares the environmental impacts of various alternatives for remedial action at the Gunnison uranium of mill tailings site located 0.5 miles south of Gunnison, Colorado. The site covers 56 acres and contains 35 acres of tailings, 2 of the original mill buildings and a water tower. The Uranium Mill Tailings Radiation Control of Act of 1978 (UMTRCA), Public Law 95-604, authorizes the US Department of Energy to clean up the site to reduce the potential health impacts associated with the residual radioactive materials remaining at the site and at associated [vicinity] properties off the site. The US Environmental Protection Agency promulgated standards for the remedial actions (40 CFR 192). Remedial actions must be performed in accordance with these standards and with the occurrence of the Nuclear Regulatory Commission. Four alternatives have been addressed in this document. The first alternative is to consolidate the tailings and associated contaminated soils into a recontoured pile on the southern portion of the existing site. A radon barrier of silty clay would be constructed over the pile and various erosion control measures would be taken to assure the long-term integrity of the pile. Two other alternatives which involve moving the tailings to new locations are assessed in this document. These alternatives generally involve greater short-term impacts and are more costly but would result in the tailings being stabilized in a location farther from the city of Gunnison. The no action alternative is also assessed

  13. Radiation risk, medical surveillance programme and radiation protection in mining and milling of uranium ores

    Mining and milling of uranium ores comprise multiple operations such as developement, drilling, blasting, handling, crushing, grinding, leaching of the ore and concentration, drying, packaging and storing of the concentrate product. Apart from the hazards of any metal mining and milling operations due to dust, noise, chemicals, accidents etc there are radiation risks also resulting from exposure to airborne radioactivity and external radiation. The inhalation risk is of more concern in underground mines than in open pit mines. The objective of a Medical Surveillance Programme (an occupational Health Programme) is to ensure a healthy work force. It should ultimately lead to health maintenance and improvement, less absenteeism increased productivity and the achievement of worker and corporate goals. The programme includes prevention, acute care, counselling and rehabilitation. Radiological workers require special monitoring for their work-related radiation exposure effect by film monitoring service, whole body counting and bioassay. Radiation protection in the mining and milling of Uranium ores include the use of personal protective equipment, work station protection, personal hygiene and house keeping. (author). 15 refs

  14. Engineering assessment of inactive uranium mill tailings: Monument Valley Site, Monument Valley, Arizona

    Ford, Bacon and Davis Utah Inc. has reevalated the Monument Valley site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Monument Valley, Arizona. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposure of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 1.1 million tons of tailings at the Monument Valley site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through IV). Cost estimates for the four options range from about $6,600,000 for stabilization in-place, to about $15,900,000 for disposal at a distance of about 15 mi. Three principal alternatives for reprocessing the Monument Valley tailings were examined: heap leaching; Treatment at an existing mill; and reprocessing at a new conventional mill constructed for tailings reprocessing. The cost of the uranium recovery is economically unattractive

  15. 226Ra and 210Pb relationship in solid wastes and plants at Uranium mill tailing

    After the uranium extraction from the ore, the waste residues (tailings) contain several radionuclides in elevated levels comparing to normal soils. Nearly all of the uranium progenies (230Th, 226Ra, 210Pb and 210Po) and the unextracted uranium fraction are present in tailings. These large quantities of tailings may provide a significant source of environmental and food chain contamination. The transfer of radioisotopes between different ecological compartments is frequently evaluated using ratios which relate the radionuclide content in one ecosystem compartment to that of another. For instance, the concentration ratio (CR), i.e., the ratio between radionuclide concentrations in tailings and plants can be evaluated. Radium-226, a long-lived alfa emitter, is a chemical analog of calcium. The 226Ra uptake is similar to calcium in biological and ecological systems. The uptake of 210Pb will follow the same pattern as natural lead. Plants do not require lead but in contrast they require the Ra/Ca group elements. The uptake of lead is mainly a function of the lead tolerance of the plant and the hydrogen ion concentration of the soil. Kalin and Sharma (1982) reported that 226Ra and 210Pb uptake by indigenous species from inactive uranium mill tailings in Canada differ from the uptake of the elements by the same plants growing in soil. Ibrahim and Whicker (1992) reported that tailing acidity tends to enhance radionuclide availability for plant uptake. The transport of radionuclides to foliage and subsequent retention and absorption may play a role in plant contamination. The main goal of this study is to evaluate the 226Ra and 210Pb relationship in tailings and plants growing at uranium mill tailings

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

    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

  17. Radioecological investigations of uranium mill tailings systems. Progress report, September 1, 1979-September 30, 1980

    The initial 13 months of this program have been devoted to staffing, development of a radiochemistry capability, development of a mill tailings reclamation study, studies on hydraulic properties of soils, initiation of plant uptake studies, preparation for metabolic studies with deer and antelope, and sample collections. Through the addition of new personnel and equipment, we are rapidly developing analytical capabilities for 238U, 230Th, 226Ra, 210Pb and 210Po in matrices such as soil, water, plant material, and animal tissues. A 4 acre study site was developed in cooperation with the Pathfinder Mines Corp. at the Shirley Basin Uranium Mine in Wyoming. The study site is designed for investigations on the influence of various kinds and thicknesses of mill tailings soil covers on the integrity of reclaimed tailings and inherent radionuclides. Studies on the hydraulic properties of various soil materials were conducted and data analysis is in progress. Plots and procedures for conducting plant uptake studies on uranium and progeny were established and long-term investigations have been initiated. A colony of tame mule deer and pronghorn antelope has been developed for studies on the uptake and retention of 210Pb and 210Po. Numerous collections of soil, vegetation and water from the Shirley Basin Uranium Mine environs were conducted and radiochemical assay is in progress

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

    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 222Rn 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

  19. Distribution coefficients of radionuclides of environmental relevance in uranium mill - tailing ponds: a laboratory study

    Radioactive elements, viz., uranium, thorium, radium and polonium may contaminate the soil and ground water around uranium milling facilities. Environmental impact of these radionuclides required measurement of their distribution coefficient (Kd) between the ground water and the soils from the mill tailing ponds. A batch sorption method was employed to measure the Kd of 233U, 230Th, 226Ra and 210Po (used as tracers for the four elements) in two soil samples one ground water sample from the site along with a synthetic water sample. Soil samples were characterized for the elemental composition using the neutron activation analysis method. Results showed high Kd values for all the elements, with Th(IV) and Po(IV) having higher values (log Kd ∼4) than U(VI) and Ra(II) (log Kd ∼3). In the case of uranium abnormally low Kd values (<100) were observed for both the soil samples with the ground water sample. This could be due to the complexation of U(VI) by carbonate anions resulting in decreased sorption by soil. (author)

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

    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.

  1. Abandoned mine site characterization for remediation: The case of the Cunha Baixa uranium mine (Viseu, Portugal)

    Uranium mining activities at Cunha Baixa ceased in 1993 and a preliminary assessment of its chemical environmental impact was performed. Acid drainage affects surface and groundwater quality up to 1-1.5 km downward from the mining site. High levels of sulphate, Al, Mn, U, and low pH values (<4.5-5) make these waters unsuitable for irrigation and livestock watering. Irrigation of acid soils (pH <4.5) with contaminated waters presents risks to the crops owing to a high content of U in the available soil fraction. Consequently, maize harvested in these soils showed amounts of uranium in roots and leaves that may pose some risk when it is used for animal feeding and the plant residues are used for soil fertilization. According to the 'tolerable daily intake' of uranium, the low uranium content in corn allows it to be used to feed animals and for flour to make bread. Thiobacillus ferrooxidans were detected in mine water, but mine wastes submitted to static and kinetic laboratory tests (acid based accounting and a 'humidity cell test') did not show any capacity to generate acid drainage from sulphide oxidation throughout the testing period. Nevertheless, open pit mine wastes can be a source of water pollution in the Cunha Baixa mining area. Acid drainage can also be a residue from the heap leaching process used in the past to recover uranium from low grade ore. (author)

  2. Diversity and characterization of sulfate-reducing bacteria in groundwater at a uranium mill tailings site

    Microbially mediated reduction and immobilization of U(VI) to U(TV) plays a role in both natural attenuation and accelerated bioremediation of uranium contaminated sites. To realize bioremediation potential and accurately predict natural attenuation, it is important to first understand the microbial diversity of such sites. In this paper, the distribution of sulfate-reducing bacteria (SRB) in contaminated groundwater associated with a uranium mill tailings disposal site at Shiprock, N.Mex,, was investigated. Two culture-independent analyses were employed: sequencing of clone libraries of PCR-amplified dissimilatory sulfite reductase (DSR) gene fragments and phospholipid fatty acid (PLFA) biomarker analysis. A remarkable diversity among the DSR sequences was revealed, including sequences from F-Proteobacteria, gram-positive organisms, and the Nitrospira division. PLFA analysis detected at least,52 different mid-chain-branched saturate PLFA and included a high proportion of 10me16:0, Desulfotomaculum and Desulfotomaculum-like sequences were the most dominant DSR genes detected. Those belonging to SRB within F-Proteobacteria were mainly recovered from low-uranium (less than or equal to 302 ppb) samples. One Desulfotomaculum like sequence cluster overwhelmingly dominated high-U (> 1,500 ppb) sites. Logistic regression showed a significant influence of uranium concentration over the dominance of this cluster of sequences (P= 0.0001), This strong association indicates that Desulfotomaculum has remarkable tolerance and adaptation to high levels of uranium and suggests the organism's possible involvement in natural attenuation of uranium. The in situ activity level of Desulfotomaculum in uranium-contaminated environments and its comparison to the activities of other SRB and other functional groups should be an important area for future research

  3. Uranium mining and milling environmental liabilities management in Germany: Lessons learned during almost two decades of implementation of the Wismut Rehabilitation Project

    Full text: From 1946 to 1990 the Soviet-German WISMUT Company produced 231 000 tonnes of Uranium and became with it the world's third largest uranium producer at that time. Due to the mining of low grade ore, about 800 Million tonnes of waste rock material, radioactive sludge's and overburden material were deposited at the sites. The mining and milling activities resulted in seriously affected and devastated areas in a densely populated region of about 10 000 km2 in Saxony and Thuringia, in East Germany. In 1990 after the German re-unification the uranium production was ceased and the German government was faced with one of its largest ecological and economic challenges because WISMUT turned at once from the production to the decommissioning phase without any preparation or preplanning. Since 1991 the national corporation WISMUT GmbH has been charged with the decommissioning of the mines, mills and other facilities and with the rehabilitation of the sites. The overall project includes abandonment and flooding of underground mines, relocation and covering of waste rock piles, dewatering and geo-chemical stabilisation tailings management facilities, demolition of structures and buildings, site clearance and rehabilitation. The WISMUT Rehabilitation Project is in an advanced stage. More than 93% of the mine workings are flooded, flooding has been accompanied by operation of powerful water treatment plants. Roughly 90% of technical structures have been demolished, relocation of 131 Million tonnes of waste rock and overburden material into the Lichtenberg open pit is terminated, and more than 60% of the rock piles and tailings management facilities have been covered. The advanced stage gives rise to draw first conclusions on the outcome of the rehabilitation activities. The present paper presents the main results of the WISMUT Rehabilitation Project and summarizes lessons learned by now. (author)

  4. Use of special oedometer tests for the remediation of large uranium mill tailings impoundments at Wismut, Germany

    The paper presents the use of recently developed special oedometer tests for designing the remediation of large uranium tailings ponds at WISMUT, Germany. Uranium ore mining and milling in eastern Germany by the former Soviet-German WISMUT company lasted from 1946 to 1990. Wastes from the hydrometallurgical uranium extraction processes were discharged into large tailings impoundments covering a total area of 5.5 km2 and containing about 150 x 106 m3 of uranium mill tailings. Tailings pond remediation is ongoing by in-place decommissioning with dewatering by technical means. Geotechnical properties and the most suitable so-called non-linear finite strain consolidation behaviour of fine uranium mill tailings are described. Decommissioning techniques comprise, among others, interim covering of under consolidated fine tailings, contouring of tailings surfaces and final covering. Contouring, in particular, has a huge potential for optimization in terms of cost reduction. For contouring total settlement portions, the spatial distribution of differential settlement portions and the time-dependent settlement rates, especially of the cohesive fine uranium mill tailings are of critical importance. A new special oedometer KD 314 S has been developed to generate all the input data needed to derive the fundamental geotechnical relationships of void ratio vs. effective stress and of permeability coefficient vs. void ratio for consolidation calculations. Since December 1999 the new special oedometer KD 314 S has been working successfully on fine uranium mill tailings from both acid and from soda alkaline milling. Results coincide with non-linear finite strain consolidation theory. The geotechnical functions derived were used as input parameters for consolidation modelling. An example of the consolidation modelling on Helmsdorf tailings pond is presented. (author)

  5. Development of a quality-based radiation protection program for a new high grade uranium mill

    COGEMA Resources Inc.'s (CRI's) operation at McClean Lake in northern Saskatchewan, Canada will process ores from the richest uranium ore deposits in the world. With the combination of high ore grades and stringent radiation requirements, new design features and a well documented quality-based radiation protection program are required for operating the uranium mill. The new McClean Lake uranium mill incorporates such features and program. The mill began operation in June 1999 and is currently licensed for an initial production capacity of six pounds U3O8 annually. The ore grades will vary up to 30% uranium. The mill design ensures that workers are separated from radioactive ore being processed through the use of a slurry handling and processing system that maximizes containment, with state-of-the-art shielding and ventilation features that protect workers against external gamma radiation, and airborne radioactive particles (radon progeny and radioactive dusts). The radiation protection program for the McClean Lake mill consists of a Radiation Protection Quality Assurance Program Manual (RPQAPM) and a series of supporting manuals, which altogether cover the 'key elements of successful health and safety management' identified in the International Commission on Radiological Protection (ICRP, 1997), Publication 75: i.e., policy and organization, planning and implementation, measuring and reviewing performance'. As lead document, the PRQAPM outlines the quality assurance administration for the program: e.g., policy statement; management review; organization and authority; staff qualifications and training; change management and non-conformities; classification of radiation areas and nuclear energy worker designation; program information; and compliance. The RPQAPM also outlines the key program elements: i.e., monitoring worker radiation doses and workplace radiological levels, monitoring ventilation, equipment protocols, management , management of radioisotopes

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

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

    1980-06-01

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

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

    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.

  8. Characterization of long-lived radioactive dust clouds generated in uranium mill operations

    The characteristics of long-lived radioactive dust clouds generated in several mechanical and physico-chemical operations in a uranium mill have been investigated. The study consisted of the determination of dust size distribution, and of the radionuclides contained in the particles of each dimension class ranging from <0.1 to 26 μm in diameter. Experiments were conducted using several cascade impactors operating at different sample flow rates. Two different types of cascade impactors were used. Radionuclide identification was done using α-spectrometry and γ-spectrometry. Long-lived and short-lived radionuclides were identified in dust samples. The characteristics of the dust clouds depended on the mill operation. The following operations were studied: crushing (vibrating grizzly, jaw crusher, cone crusher); screening; ore transportation; grinding; acid leaching; counter-current decantation; yellowcake precipitation and drying; and yellowcake packaging. In addition, other dust and radioactivity measurements have been carried out

  9. Implementation of a procedure to determine remedial action requirements for contamination at uranium mill tailings sites

    This paper describes a procedure used at the Riverton and Green River Uranium Mill Tailings Remedial Action (UMTRA) Project sites to determine the necessary removal of chemical contaminants from subpile soils to safe levels. Cleanup criteria for chemical contaminants were developed independent of existing cleanup criteria for radionuclides. The two sites were chosen because they were representative of all 24 UMTRA sites and were scheduled to undergo remediation in the near future. An initial compilation of existing data indicated that additional analyses were required to fully characterize the site for As, Mo, Se, U, and V. Accordingly, archived samples from prior radiological characterizations for the tailings pile, subpile, mill yard and windblown areas were selected for subsequent laboratory analyses

  10. Environmental assessment of remedial action at the Mexican Hat uranium mill tailings site, Mexican Hat, Utah

    This document assesses the environmental impacts of the proposed remedial action at the Mexican Hat uranium mill tailings site located on the Navajo Reservation in southern Utah. The site covers 235 acres and contains 69 acres of tailings and several of the original mill structures. Remedial action must be performed in accordance with standards and with the concurrence of the US Nuclear Regulatory Commission and the Navajo Nation. The proposed action is to stabilize the tailings within the present tailings site by consolidating the tailings and associated contaminated soils into a recontoured pile. A radon barrier of compacted earth would be constructed over the pile, and various erosion control measures would be taken to assure the long-term stability of the pile. The no action alternative is also assessed in this document. 240 refs., 12 figs., 20 tabs

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

    This paper describes methods for estimating potential health effects from exposure to uranium mill tailings and presents a summary of risk projections for 57 mill tailings contaminated properties (residences, schools, churches, and businesses) in the United States. 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%

  12. Leaching of molybdenum and arsenic from uranium ore and mill tailings

    Landa, E.R.

    1984-01-01

    A sequential, selective extraction procedure was used to assess the effects of sulfuric acid milling on the geochemical associations of molybdenum and arsenic in a uranium ore blend, and the tailings derived therefrom. The milling process removed about 21% of the molybdenum and 53% of the arsenic initially present in the ore. While about one-half of the molybdenum in the ore was water soluble, only about 14% existed in this form in the tailings. The major portion of the extractable molybdenum in the tailings appears to be associated with hydrous oxides of iron, and with alkaline earth sulfate precipitates. In contrast with the pattern seen for molybdenum, the partitioning of arsenic into the various extractable fractions differs little between the ore and the tailings. ?? 1984.

  13. Environmental assessment of remedial action at the slick rock Uranium Mill Tailings sites Slick Rock, Colorado

    1994-09-01

    The Uranium Mill Tailings Radiation Control Act of 1978 (42 USC {section} 7901 et seq.), hereafter referred to as the UMTRCA, authorized the U.S. Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miguel County. The purpose of the cleanup is to reduce the potential health effects associated with the radioactive materials remaining on the sites and on vicinity properties (VPs) associated with the sites. Contaminated materials cover an estimated 55 acres of the Union Carbide (UC) processing site and 12 ac of the North Continent (NC) processing site. The total estimated volume of contaminated materials is approximately 61 8,300 cubic yards. In addition to the contamination in the two processing site areas, four VPs were found to contain contamination. As a result of the tailings being exposed to the environment, contamination associated with the UC and NC sites has leached into shallow ground water. Surface water has not been affected. The closest residence is approximately 0.3 air mi from either site. The proposed action is to remediate the UC and NC sites by removing all contaminated materials within the designated site boundaries or otherwise associated with the sites, and relocating them to, and stabilizing them at, a location approximately 5 road mi (8 km) northeast of the sites on land administered by the Bureau of Land Management (BLM). Remediation would be performed by the DOE`s Uranium Mill Tailings Remedial Action (UMTRA) Project. All solid contaminated materials would be buried under 5 feet (ft) of rock and soil materials. The proposed disposal site area is currently used by ranchers for cattle grazing over a 7-month period. The closest residence to the proposed disposal site is 2 air mi. An estimated 44 ac of land would be permanently transferred from the BLM to the DOE and restricted from future use.

  14. Design of rock covers for reclaimed uranium mill tailings impoundments: A regulatory perspective

    Public Law 95-604, the Uranium Mill Tailings Radiation Control Act of 1978, provides the Department of Energy with authority to perform remedial actions at designated inactive uranium mill sites. The Environmental Protection Agency promulgated radiological and non-radiological standards (40 CFR 192) for remedial actions at inactive uranium mill sites. All remedial actions require the concurrence of the Nuclear Regulatory Commission (NRC). The standards set forth in 40 CFR 192 require that remedial action designs provide reasonable assurance that tailings will be controlled for 1000 years (to the extent reasonably achievable) and, in any case, for at least 200 years. Implementation of this criteria requires the use of sound engineering practice combined with engineering judgment in many analytical areas. It has been the experience of the NRC staff that the design of a rock cover can be significantly affected by the selection of the design flood or design precipitation event. Preliminary reviews conducted by the NRC staff for various remedial action sites have indicated that a range of design assumptions and strategies are used in the determination of design basis floods and precipitation events for rock cover designs. The NRC staff has concluded that EPA criteria are met if the designs for erosion protection covers are based on the concepts of the Probable Maximum Flood (PMF) and the Probable Maximum Precipitaton (PMP), and that EPA criteria may not be met by the use of statistically-derived flood estimates. In addition, dam failures need to be analyzed at those sites where upstream dams are not designed for a PMF

  15. Summary of the engineering assessment of inactive uranium mill tailings: Falls City site, Falls City, Texas

    Ford, Bacon and Davis Utah Inc. has reevaluated the Falls City site in order to update the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranum mill tailings at Falls City, Texas. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrolgy and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.5 million tons of tailings at the Falls City site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $21,700,000 for stabilization in place, to about $35,100,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Falls City tailings were examined: heap leaching; treatment at an existing mill; reprocessing at a new conventional mill constructed for tailings reprocessing. The tailings piles are presently being rewashed for uranium recovery by Solution Engineering, Inc. The cost for further reprocessing would be about $250/lb of U3O8. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery does not appear to be economically attractive for the foreseeable future

  16. Summary of the engineering assessment of inactive uranium mill tailings: Falls City site, Falls City, Texas

    None

    1981-10-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Falls City site in order to update the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranum mill tailings at Falls City, Texas. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrolgy and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 2.5 million tons of tailings at the Falls City site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite decontamination with the addition of 3 m of stabilization cover material, to removal of the tailings to remote disposal sites and decontamination of the tailings site. Cost estimates for the four options range from about $21,700,000 for stabilization in place, to about $35,100,000 for disposal at a distance of about 15 mi. Three principal alternatives for the reprocessing of the Falls City tailings were examined: heap leaching; treatment at an existing mill; reprocessing at a new conventional mill constructed for tailings reprocessing. The tailings piles are presently being rewashed for uranium recovery by Solution Engineering, Inc. The cost for further reprocessing would be about $250/lb of U/sub 3/O/sub 8/. The spot market price for uranium was $25/lb early in 1981. Therefore, reprocessing the tailings for uranium recovery does not appear to be economically attractive for the foreseeable future.

  17. Environmental assessment of remedial action at the slick rock Uranium Mill Tailings sites Slick Rock, Colorado

    The Uranium Mill Tailings Radiation Control Act of 1978 (42 USC section 7901 et seq.), hereafter referred to as the UMTRCA, authorized the U.S. Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miguel County. The purpose of the cleanup is to reduce the potential health effects associated with the radioactive materials remaining on the sites and on vicinity properties (VPs) associated with the sites. Contaminated materials cover an estimated 55 acres of the Union Carbide (UC) processing site and 12 ac of the North Continent (NC) processing site. The total estimated volume of contaminated materials is approximately 61 8,300 cubic yards. In addition to the contamination in the two processing site areas, four VPs were found to contain contamination. As a result of the tailings being exposed to the environment, contamination associated with the UC and NC sites has leached into shallow ground water. Surface water has not been affected. The closest residence is approximately 0.3 air mi from either site. The proposed action is to remediate the UC and NC sites by removing all contaminated materials within the designated site boundaries or otherwise associated with the sites, and relocating them to, and stabilizing them at, a location approximately 5 road mi (8 km) northeast of the sites on land administered by the Bureau of Land Management (BLM). Remediation would be performed by the DOE's Uranium Mill Tailings Remedial Action (UMTRA) Project. All solid contaminated materials would be buried under 5 feet (ft) of rock and soil materials. The proposed disposal site area is currently used by ranchers for cattle grazing over a 7-month period. The closest residence to the proposed disposal site is 2 air mi. An estimated 44 ac of land would be permanently transferred from the BLM to the DOE and restricted from future use

  18. Assessment of radiation exposure around abandoned uranium mining area of Stara planina Mt., Serbia

    Tanić Milan N.

    2014-01-01

    Full Text Available The aim of this work was to estimate the health and radiation hazard due to external irradiation from terrestrial radionuclides in the Stara planina Mt. region, which is important because of past uranium mining activities on the mountain. Soil samples were collected inside the flotation processing facilities, their surroundings and more distant locations, i.e. from areas considered certainly affected, potentially affected, and unaffected by former mining and uranium ore processing activities. The radiological and health risk assessments were done by calculating the six main parameters, based on the activity concentration of 238U, 232Th, and 40K in soil samples as determined by gamma-ray spectrometry. Increased values of the risk parameters were observed only for sites where uranium ore was processed, while the location surrounding these compounds showed values that are usual for this mountain or slightly above them. Calculations of the risk parameters for the background area showed no radiation risk for the local and seasonal population. The presence of U and Th was detected in all water samples from creeks surrounding the facilities, but only in the water from the facility drainage pipe did their concentration exceed the limits given for the uranium content in drinking water. In conclusion, the results obtained in this study fall within the range of values in similar studies conducted worldwide and are below the values which can cause a significant radiation hazard. [Projekat Ministarstva nauke Republike Srbije, br. III43009 i br. III41005

  19. Environmental Assessment of Remedial Action at the Riverton Uranium Mill Tailings Site, Riverton, Wyoming

    The US Department of Energy (DOE) has prepared an environmental assessment (DOE/EA-0254) on the proposed remedial action at the inactive uranium milling site near Riverton, Wyoming. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321, et seq.). Therefore, the preparation of an environmental impact statement (EIS) is not required

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

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

  1. Environmental assessment of remedial action at the Maybell uranium mill tailings site near Maybell, Colorado

    1993-09-01

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment (Attachment 1) and a floodplain/wetlands assessment (Assessment 2) are included as part of this EA. The following sections and attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service.

  2. Evaluation of the mill tailings disposal site at the Zirovski vrh uranium mine in Slovenia

    Uranium mine Zirovski vrh in Slovenia was closed due to economic reasons. After that extensive work on decommission was done. The results of the comparison between three potential sites for mill tailings are presented. The results of the probabilistic approach to the factors of safety and confidence, seismic hazard analysis, hydrogeological models and in the economic evaluation are given. For the common evaluation they were interpreted in the way of UMTRA decision matrix. On the basis of the engineering judgement calculations for the recent status and the status after 1000 years was performed. (author)

  3. Environmental Assessment of Remedial Action at the Riverton Uranium Mill Tailings Site, Riverton, Wyoming

    None

    1987-06-01

    The US Department of Energy (DOE) has prepared an environmental assessment (DOE/EA-0254) on the proposed remedial action at the inactive uranium milling site near Riverton, Wyoming. Based on the analyses in the EA, the DOE has determined that the proposed action does not constitute a major Federal action significantly affecting the quality of the human environment within the meaning of the National Environmental Policy Act (NEPA) of 1969 (42 U.S.C. 4321, et seq.). Therefore, the preparation of an environmental impact statement (EIS) is not required.

  4. Licensing and regulatory requirements for uranium mining and milling in Brazil

    This paper describes the primary objectives, principles and requirements used in the regulation of uranium mining and milling facilities in Brazil, providing an understanding of the licensing process. Some specific aspects of the regulatory process are discussed in detail to show where regulations should be updated and improved. The author believes that is necessary to establish some balance between the risks of the project and the assessment effort required. The views expressed in this paper are personal considerations of the author and do not represent those of the Brazilian Nuclear Regulatory Body. (author)

  5. Uranium Mill Tailings Remedial Action Project Safety Advancement Field Effort (SAFE) Program

    1994-02-01

    In 1992, the Uranium Mill Tailings Remedial Action (UMTRA) Project experienced several health and safety related incidents at active remediation project sites. As a result, the U.S. Department of Energy (DOE) directed the Technical Assistance Contractor (TAC) to establish a program increasing the DOE`s overall presence at operational remediation sites to identify and minimize risks in operations to the fullest extent possible (Attachments A and B). In response, the TAC, in cooperation with the DOE and the Remedial Action Contractor (RAC), developed the Safety Advancement Field Effort (SAFE) Program.

  6. Asphalt emulsion radon barrier systems for uranium mill tailings - a summary of the technology

    Pacific Northwest Laboratory (PNL), has developed an asphalt emulsion cover system to reduce the release of radon from uranium mill tailings. The system has been field-tested at the tailings site in Grand Junction, Colorado. Results from laboratory and field tests indicate that this system effectively reduces radon release to near-background levels (-2s-1) and has the properties required for long-term effectiveness and stability. Engineering specifications have been developed, and a cost analysis indicates that asphalt emulsion covers are competitive with other cover systems. 6 references, 2 figures, 4 tables

  7. Uranium Mill Tailings Remedial Action Project Safety Advancement Field Effort (SAFE) Program

    In 1992, the Uranium Mill Tailings Remedial Action (UMTRA) Project experienced several health and safety related incidents at active remediation project sites. As a result, the U.S. Department of Energy (DOE) directed the Technical Assistance Contractor (TAC) to establish a program increasing the DOE's overall presence at operational remediation sites to identify and minimize risks in operations to the fullest extent possible (Attachments A and B). In response, the TAC, in cooperation with the DOE and the Remedial Action Contractor (RAC), developed the Safety Advancement Field Effort (SAFE) Program

  8. Preliminary evaluation of uranium mill tailings conditioning as an alternative remedial action technology

    Conditioning of uranium mill tailings is being investigated as an alternative remedial action for inactive tailings piles to be stabilized by the US Department of Energy. Tailings from high priority sites have been characterized for elemental composition, mineralogy, aqueous leachable contaminants, and radon emanation power to provide a baseline to determine the environmental hazard control produced by conditioning. Thermal stabilization of tailings at high temperatures and removal of contaminants by sulfuric acid leaching are being investigated for technical merit as well as economic and engineering feasibility

  9. Environmental assessment of remedial action at the Maybell uranium mill tailings site near Maybell, Colorado

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment (Attachment 1) and a floodplain/wetlands assessment (Assessment 2) are included as part of this EA. The following sections and attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service

  10. Uranium mining and milling waste management in Northern Saskatchewan. Extended abstract

    This extended abstract presents a review of the effectiveness of waste management practices currently used in Northern Saskatchewan's uranium mining industry. Short-term improvements could be made to waste rock management. Long-term improvements include extracting toxic metals from the tailings pit, and creating a recycle loop for the effluent water to be returned for use in the mill. Additional regulatory involvement was seen as necessary to implement the suggested improvements, either through an incentive system for extraction similar to carbon trading or via increased enforcement of lifetime total metals accumulation and loading limits. (author)

  11. Solar repowering/industrial retrofit systems study Gulf Mt. Taylor Uranium Mill solar retrofit

    The development of a site-specific conceptual design for solar industrial retrofit of the Gulf Mt. Taylor Uranium Mill is reported. Effort to date has resulted in preparation of a preliminary System Requirements specification, conduct of trade studies to select a system concept, and related design, performance, cost estimating and economic analysis to support the concept selection. A baseline system with no storage and an alternative system with extended storage were evaluated. The baseline system with no storage was selected because it provides the best overall opportunity for fuel displacement, operating experience in industrial application and successful demonstration in the near term

  12. Leaching of radionuclides from uranium ore and mill tailings ( Ra- 226, Tn-230).

    Landa, E.R.

    1982-01-01

    The major part of the extractable uranium is associated with a readily acid-soluble fraction in both ore and tailings. The major part of the extractable 226Ra was associated with an iron, manganese hydrous-oxide fraction in the ore and tailings. Thorium-230 was the least leachable of the radionuclides studied. The major portion of the extractable 230Th was associated with alkaline-earth sulphate precipitates, organic matter, or both. The specific effects of milling on each of the nuclides are discussed.-Author

  13. Effects of uranium mining and milling on surface water in New Mexico

    Currently, there are 35 active mines, 5 mills and 4 ion exchange plants in the Grants area. There was a general increase in uranium and vanadium with time over the San Jose and Puerco System. This doesn't appear to be related to any individual discharge but most likely reflects the general increase in activity in the area. As mining continues, this increase is expected to continue. The project reported here involved determining physical and chemical parameters of the water in the San Jose-Puerco system in New Mexico between March 1978 and September 1980. 14 refs

  14. Long term population dose due to radon (Rn-222) released from uranium mill tailings

    The results of a study undertaken by the European Commission on the external costs (environmental and social) of various energy production systems is likely to be influential in determining how the European Union will develop its energy supply systems. The estimated costs for nuclear power from the study will be based on the findings of the United Nations Scientific Committee on the Effects of Atomic Radiation (UNSCEAR), with the costs being dominated by the estimated long term (10,000 y) population doses due to radon (Rn-222) released from mill tailings. UNSCEAR developed a central estimate of 150 person-Sv per GW y and a range of 1 to 1,000 person-Sv per GW y. However, the generic data available to and being used by UNSCEAR are dated and are not appropriate for the current and planned future conditions in the uranium production industry, with the result that the estimated external costs of nuclear power (specifically, the doses due to radon emitted from mill tailings) are overestimated. The Uranium Institute sponsored a study to estimate long term population doses based on the most recent 1993 UNSCEAR methodology, but using data that would be more appropriate to the current major uranium production facilities. Site-specific information obtained from the owners/operators and the Uranium Institute included: present and proposed tailings management plans; tailings volumes and areas; ore grades and reserves; measurements and estimates of radon emission rates; and population densities. Tailings at closed facilities that no longer contribute to uranium production were not evaluated since it was assumed that these radon sources need not be considered in evaluating the external costs of current and future nuclear power production. Based on the same approach as UNSCEAR, but using a more sophisticated air dispersion model, and more site-specific data relative to existing sites and proposed tailings management practices, radon emission rates and population densities (that

  15. Uranium Mill Tailings Remedial Action Project fiscal year 1997 annual report to stakeholders

    The fiscal year (FY) 1997 annual report is the 19th report on the status of the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. In 1978, Congress directed the DOE to assess and clean up contamination at 24 designated former uranium processing sites. The DOE is also responsible for cleaning up properties in the vicinity of the sites where wind and water erosion deposited tailings or people removed them from the site for use in construction or landscaping. Cleanup has been undertaken in cooperation with state governments and Indian tribes within whose boundaries the sites are located. It is being conducted in two phases: the surface project and the groundwater project. This report addresses specifics about the UMTRA surface project

  16. Radiologic characterization of the Mexican Hat, Utah, uranium mill tailings remedial action site: Addendum D1

    Ludlam, J.R.

    1985-01-01

    This radiologic characterization of the inactive uranium millsite at Mexican Hat, Utah, was conducted by Bendix Field Engineering Corporation for the US Department of Energy (DOE), Grand Junctions Project Office in response to and in accord with a Statement of Work prepared by the DOE Uranium Mill Tailings Remedial Action Project (UMTRAP) Technical Assistance Contractor, Jacobs Engineering Group, Inc. The objective of this project was to determine the horizontal and vertical extent of contamination that exceeds the US Environmental Protection Agency (EPA) standards at the Mexican Hat site. The data presented in this report are required for characterization of the areas adjacent to the Mexican Hat tailings piles and for the subsequent design of cleanup activities. Some on- pile sampling was required to determine the depth of the 15-pCi/g Ra- 226 interface in an area where wind and water erosion has taken place.

  17. Fiscal year 1996 annual report to stakeholders, Uranium Mill Tailings Remedial Action Project

    This is the Fiscal Year (FY) 1996 annual report on the status of the US Department of Energy's (DOE) Uranium Mill Tailings Remedial Action (UMTRA) Project. In 1978, Congress directed the DOE to assess and clean up contamination at 24 designated former uranium processing sites. The DOE is also responsible for cleaning up properties in the vicinity of the sites where wind and water erosion deposited tailings or people removed them from the site for use in construction of landscaping. Cleanup is being undertaken in cooperation with state governments and Indian tribes within whose boundaries the sites are located. It is being conducted in two phases: the surface project and the ground water project. This report addresses specifics about the surface phase of the UMTRA Project

  18. Analysis of spatial distribution and inventory of radioactivity within the uranium mill tailings impoundment

    Results are presented of the characterization of radioactivity inventory of Zapadnoe uranium mill tailings impoundment situated at Pridneprovsky Chemical Plant (PChP; Dneprodzerginsk, Ukraine). Analyses of radioactivity data set based on analytical studies of core material from 15 characterization boreholes allowed significantly refining waste volume and radioactivity inventory estimates. Geostatistical analyses using variogram function have established that radioactivity distribution in Zapadnoe tailings is characterized by regular spatial correlation patterns. Ordinary kriging method was applied to assess distribution of radioactivity in 3D. Results of statistical analyses suggest significant redistribution of uranium in the dissolved form in the residues (presumably due to water infiltration process). The developed structural model for radioactivity distribution is used for further risk assessment analyses. Derived radioactivity correlation scales can be used for optimization of sample collection when characterizing the PChP Site and similar contaminated sites elsewhere

  19. Uptake of Uranium and Other Elements of Concern by Plants Growing on Uranium Mill Tailings Disposal Cells

    Joseph, C. N.; Waugh, W.; Glenn, E.

    2015-12-01

    The U.S. Department of Energy (DOE) is responsible for long-term stewardship of disposal cells for uranium mill tailings throughout the United States. Rock-armored disposal cell covers create favorable habitat for deep-rooted plants by reducing soil evaporation, increasing soil water storage, and trapping windblown dust, thereby providing water and nutrients for plant germination and establishment. DOE is studying the tradeoffs of potential detrimental and beneficial effects of plants growing on disposal cell covers to develop a rational and consistent vegetation management policy. Plant roots often extend vertically through disposal cell covers into underlying tailings, therefore, uptake of tailings contaminants and dissemination through animals foraging on stems and leaves is a possible exposure pathway. The literature shows that plant uptake of contaminants in uranium mill tailings occurs, but levels can vary widely depending on plant species, tailings and soil chemistry, and cover soil hydrology. Our empirical field study measured concentrations of uranium, radium, thorium, molybdenum, selenium, manganese, lead, and arsenic in above ground tissues harvested from plants growing on disposal cells near Native American communities in western states that represent a range of climates, cover designs, cover soil types, and vegetation types. For risk screening, contaminant levels in above ground tissues harvested from plants on disposal cells were compared to Maximum Tolerance Levels (MTLs) set for livestock by the National Research Council, and to tissue levels in the same plant species growing in reference areas near disposal cells. Although tailings were covered with uncontaminated soils, for 14 of 46 comparisons, levels of uranium and other contaminants were higher in plants growing on disposal cells compared to reference area plants, indicating possible mobilization of these elements from the tailing into plant tissues. However, with one exception, all plant

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

    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

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

    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.

  2. Evolution of uranium distribution and speciation in mill tailings, COMINAK Mine, Niger.

    Déjeant, Adrien; Galoisy, Laurence; Roy, Régis; Calas, Georges; Boekhout, Flora; Phrommavanh, Vannapha; Descostes, Michael

    2016-03-01

    This study investigated the evolution of uranium distribution and speciation in mill tailings from the COMINAK mine (Niger), in production since 1978. A multi-scale approach was used, which combined high resolution remote sensing imagery, ICP-MS bulk rock analyses, powder X-ray diffraction, Scanning Electron Microscopy, Focused Ion Beam--Transmission Electron Microscopy and X-ray Absorption Near Edge Spectroscopy. Mineralogical analyses showed that some ore minerals, including residual uraninite and coffinite, undergo alteration and dissolution during tailings storage. The migration of uranium and other contaminants depends on (i) the chemical stability of secondary phases and sorbed species (dissolution and desorption processes), and (ii) the mechanical transport of fine particles bearing these elements. Uranium is stabilized after formation of secondary uranyl sulfates and phosphates, and adsorbed complexes on mineral surfaces (e.g. clay minerals). In particular, the stock of insoluble uranyl phosphates increases with time, thus contributing to the long-term stabilization of uranium. At the surface, a sulfate-cemented duricrust is formed after evaporation of pore water. This duricrust limits water infiltration and dust aerial dispersion, though it is enriched in uranium and many other elements, because of pore water rising from underlying levels by capillary action. Satellite images provided a detailed description of the tailings pile over time and allow monitoring of the chronology of successive tailings deposits. Satellite images suggest that uranium anomalies that occur at deep levels in the pile are most likely former surface duricrusts that have been buried under more recent tailings. PMID:26747998

  3. Comment and response document for the final remedial action plan and site design for stabilization of the inactive uranium mill tailings sites at Slick Rock, Colorado. Revision 2

    This document for the final remedial action plan and site design has been prepared for US Department of Energy Environmental Restoration Division as part of the Uranium Mill Tailings Remedial Action plan. Comments and responses are included for the site design for stabilization of the inactive uranium mill tailings sites at Slick Rock, Colorado

  4. Remedial action plan and site design for stabilization of the inactive uranium mill tailings sites at Rifle, Colorado

    1992-02-01

    This appendix assesses the present conditions and data gathered about the two inactive uranium mill tailings sites near Rifle, Colorado, and the designated disposal site six miles north of Rifle in the area of Estes Gulch. It consolidates available engineering, radiological, geotechnical, hydrological, meteorological, and other information pertinent to the design of the Remedial Action Plan (RAP). The data characterize conditions at the mill, tailings, and disposal site so that the Remedial Action Contractor (RAC) may complete final designs for the remedial actions.

  5. Mobility of radium and uranium in an uranium mill tailings deposit

    In France, the extraction of uranium for nuclear power plants has generated more than 60 millions tons of residues. They are disposed at the surface and contain still more than 70 % of the initial activity of the ores due to the presence of uranium 238 daughters like thorium 230, radium 226 and lead 210. When water percolates through the tailings, the radioelements can migrate until they reach the geosphere. The radioelements rate coming from such a disposal depends on the hydrodynamic characteristics of the site and on the physicochemical processes which control the mobility of the radioelements. Therefore, we have studied the geochemical behaviour of radium and uranium at the Lengenfeld site in Germany. Analysis of the residues has allowed us to reconstituted the history of the site. The disposal was probably the result of an alkaline treatment applied to a mixture of granitic and sedimentary ores. Moreover, this analysis has permitted us to determine the nature of the mineral phases which can sorb the radioelements (clays, carbonate phases and iron oxo-hydroxides). For some of them, a mechanism of sorption was proposed and the associated constants were determined. Applying geochemical codes to our results has shown which solids control the solution composition and has also permitted us to estimate the distribution of radium between the solid and solution phases. From these data, the beginning of a prediction of the radium mobility evolution with time, at the Lengenfeld site, has been carried out. (authors)

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

    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

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

    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

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

    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.

  9. Exploring implicit dimensions underlying risk perception of waste from mining and milling of uranium ores in France

    Understanding public perceptions of risks is increasingly considered to be important in order to make sound policy decisions. For many years, social scientists have been working to understand why the public is so concerned about nuclear energy and radioactive waste. Indeed, risk perception studies have essentially focused on high-level nuclear waste. As a result, there is now a fair understanding of what determines public support or opposition to high-level nuclear waste storage and disposal facilities. However, to date, little research has been conducted into radioactive waste from mining and milling of uranium ores. In France, such waste have a much debated legal status, which illustrates their ambiguous origin (natural versus artificial) and the manner people can perceive them. Therefore, it seems relevant to explore the individual judgements, attitudes and beliefs towards risk associated with uranium mill tailings. The present study provides a structural model based on both the identification and analysis of implicit dimensions underlying risk perception (psychological, cultural, moral...) applied to the case of french uranium mill tailings. One objective of the research has been to develop an interview grid based on this conceptual model in order to elicit social demand beyond public attitudes. Semi-structured interviews have been conducted on site in french uranium bearing areas. The relationships inferred between identified risk characteristics and contextual risk perceptions suggest that five majors thematics (time, space, nature, ethics and trust) build determinants of the public's perceptions of risk related to waste from mining and milling of uranium ores. (author)

  10. A state-of-the-art methodology for impact assessment of covered uranium mill tailings

    An impact assessment methodology is being developed that integrates several advanced modelling and characterisation techniques for the purpose of assessing the current and future environmental and health impact of a surface repository containing wastes from uranium milling and radium processing. The former radium processing plant at Olen, Belgium, accumulated during nearly half a century considerable amounts of radium-containing wastes. Also present at the site are uranium mill tailings. These wastes were disposed of in a heavily engineered surface repository at the occasion of a remediation plan carried out in the mid eighties. The repository contains several concrete bunkers covered with a multi-layer hydraulic barrier. In the current impact assessment study the only exposure pathway discussed is by contamination of groundwater. For this purpose we calculated variably-saturated water flow in the multi-layer barrier and the underlying waste zones and used geochemical modelling to estimate the chemical species and their solubility's in the aqueous phase of the various waste forms. The assessment further includes modelling of contaminant leaching from the tailings towards the groundwater, contaminant transport in the surrounding groundwater towards a water well, and evaluation of the doses for ingestion, inhalation and external irradiation resulting from use of groundwater from the well. Details of the waste and site characterisation as well as contaminant modelling are discussed. (author)

  11. Leak detection systems for uranium mill tailings impoundments with synthetic liners

    This study evaluated the performance of existing and alternative leak detection systems for lined uranium mill tailings ponds. Existing systems for detecting leaks at uranium mill tailings ponds investigated in this study included groundwater monitoring wells, subliner drains, and lysimeters. Three alternative systems which demonstrated the ability to locate leaks in bench-scale tests included moisture blocks, soil moisture probes, and a soil resistivity system. Several other systems in a developmental stage are described. For proper performance of leak detection systems (other than groundwater wells and lysimeters), a subgrade is required which assures lateral dispersion of a leak. Methods to enhance dispersion are discussed. Cost estimates were prepared for groundwater monitoring wells, subliner drain systems, and the three experimental systems. Based on the results of this report, it is suggested that groundwater monitoring systems be used as the primary means of leak detection. However, if a more responsive system is required due to site characteristics and groundwater quality criteria, subliner drains are applicable for ponds with uncovered liners. Leak-locating systems for ponds with covered liners require further development. Other recommendations are discussed in the report

  12. Project licensing plan for UMTRA [Uranium Mill Tailings Remedial Action] sites

    The purpose of the Uranium Mill Tailings Remedial Action (UMTRA) Project Licensing Plan is to establish how a disposal site will be licensed, and to provide responsibilities of participatory agencies as legislated by the Uranium Mill Tailings Radiation Control Act (UMTRCA) of 1978 (Public Law 95-604). This Plan has been developed to ensure that the objectives of licensing are met by identifying the necessary institutional controls, participatory agency responsibilities, and key milestones in the licensing process. The Plan contains the legislative basis for and a description of the licensing process (''Process'') for UMTRA sites. This is followed by a discussion of agency responsibilities, and milestones in the Process. The Plan concludes with a generic timeline of this Process. As discussed in Section 2.1, a custodial maintenance and surveillance plan will constitute the basis for a site license. The details of maintenance and surveillance are discussed in the Project Maintenance and Surveillance Plan (AL-350124.0000). 5 refs., 4 figs

  13. An analysis of control standards for the long-term containment of uranium mill tailings

    The Environmental Protection Agency (EPA) standards require the control of uranium mill tailings for 1,000 years (to the extent reasonable achievable) and, in any case, for at least 200 years. Probabilities of hydrologic and/or geologic events associated with meeting the EPA standards for long-term containment of uranium mill tailings indicate the following: 1. Design events with a return period of 10,000 years or more must be used to achieve a containment standard of 200 or 1,000 years; and 2. Maximum credible events must be used in the facility design to achieve a low risk of failure over the containment life. Maximum credible events are earthquakes, floods, winds or other natural processes that may occur at the tailings site. These events do not have a specified return period or associated probability of occurrence. The size of the event is determined from historic data combined with an analysis of the geologic, hydrologic and meteorologic setting. Such events define the reasonable upper limit of a natural event in a given area. Beyond this limit the probability of a larger event occurring is low. Thus, facilities designed using a maximum credible event would have a low risk of failure and, consequently, would meet the EPA standards

  14. Treatment of liquid effluent from uranium mines and mills during and after operation

    The Australian research programme examined three separate topics, all related to the processing of uranium mill effluents. The topics covered conventional line treatment of process liquor and the application of the emerging technologies, nanofiltration and wetlands, to the treatment of higher quality run-off waters. The investigation of the lime treatment processes focused on changes in operating strategies to increase the density of the resulting sludge. The wetland study examined factors potentially limiting bacterial sulphate reduction, namely carbon limitation and competition with iron reducing bacteria for carbon and energy. For the wetland sediment used in the experimental programme, it was found iron reduction activity was not likely to significantly limit sulphate reduction. Carbon limitation of bacterial activity was, however, found to be a significant factor in poor sulphate removal efficiency. The use of green algae as a low cost, rapidly produced carbon source to promote sulphate reduction was then investigated. Reduction of sulphate by bacteria grown on algeal biomass was demonstrated at benchscales less than 10 kg of biomass was required to drive bacterial reduction of 1t of sulphate. The final topic investigated the potential of nanofiltration to remove dissolved species from typical uranium mill effluents. The separation performance was found to vary significantly with membrane type, but rejection of divalent methods ions was generally high, with good selectivity over single valent ions. (author)

  15. Recent initiatives to improve tailings and water management in the expanding Australian uranium milling industry

    This paper discusses the environmental and safety related changes that have recently occurred, or are about to be implemented in the Australian uranium milling industry. There are several drivers for these changes. The most important are the significant expansions to the Ranger and Olympic Dam uranium mills, the mining of a new orebody at Ranger and Government permission for the development of the Jabiluka deposit. The major changes in the operation of mines relate to the conservation and recycle of water, an important environmental issue in the arid country surrounding the Olympic Dam deposit, and tailings disposal strategies recently adopted or under consideration. These strategies include methods such as central thickened discharge, and cemented paste-fill for both underground and above ground disposal. The new ICRP 60 recommendations concerning radiation exposure have not been of major concern to the Australian industry, as dose rates have been historically less than the new limits. Current and expected dose rates are discussed in the context of these recommendations. (author)

  16. The 226 Ra, 210 Pb and essential elements bioavailability to pines at Urgeirica uranium mill tailings

    The objective of this study is to correlate the uptake of the natural radionuclides 226Ra and 210Pb with the essential elements, potassium, calcium and magnesium in the pines growing at the 'Urgeirica uranium mill tailings. It can be concluded that the potassium, calcium and magnesium mean concentration ratio values are, about two to three orders of magnitude, higher than the values obtained to 226Ra and 210Pb for pines growing on the Urgeirica uranium mill tailings. The concentration ratio values higher than 1 obtained to the potassium, calcium and magnesium elements indicate that pines are behaving as accumulators to these elements. Contrarily, the 226Ra and 210Pb concentration ratio values lower than 1 indicates that pines are behaving as excluders to these radionuclides. So, it can be concluded that this kind of plants is not suitable to a phyto remediation strategy. In general, a marginally significant correlation was observed between the potassium, calcium and magnesium concentrations, the cation-exchange capacity and the ph in the tailings and the 226Ra and 210Pb pines/tailings concentration ratios. (N.C.)

  17. Fractal analysis of spatial distribution of radon exhalation rates of uranium mill tailings

    A uranium mill tailings, located in Guangdong, was selected for spatial distribution of the radon exhalation rates measured by local static method. The two-dimension surface of radon exhalation rates was established by Surfer using the data of spatial distribution of radon exhalation rates measured at August 14, 2007 to 19 and 21, which was analyzed by fractal method of projective covering. The results show that the two-dimension surface of radon exhalation rates is of fractal structure. The fractal dimension of surface of radon exhalation rates from August 14, 2007 to 19 and 21 are 2.0535, 2.0173, 2.0029, 2.0084, 2.0079, 2.0057 and 2.0034, respectively, which indicates that the complexity of spatial distribution of the radon exhalation rates at 14 and 15 are larger than that of the other days. The phenomenon results from the change of precipitation and temperature, as well as the features of uranium mill tailings, including mineral composition, particle size, radium content, porosity and pore connectivity, etc. (authors)

  18. Remedial Action Plan and site design for stabilization of the inactive uranium mill tailings site at Gunnison, Colorado

    The US Environmental Protection Agency (EPA) has established health and environmental protection regulations to correct and prevent groundwater contamination resulting from processing activities at inactive uranium milling sites (40 CFR 192). The US Department of Energy (DOE) is responsible for assessing the inactive uranium processing sites. The DOE has determined this assessment shall include information on hydrogeologic site characterization. This document contains appendices to Attachment 3, Groundwater Hydrology Report included are calculations

  19. NUCLEAR ISOTOPIC DILUTION OF HIGHLY ENRICHED URANIUM BY DRY BLENDING VIA THE RM-2 MILL TECHNOLOGY

    Raj K. Rajamani; Sanjeeva Latchireddi; Vikas Devrani; Harappan Sethi; Roger Henry; Nate Chipman

    2003-08-01

    DOE has initiated numerous activities to focus on identifying material management strategies to disposition various excess fissile materials. In particular the INEEL has stored 1,700 Kg of offspec HEU at INTEC in CPP-651 vault facility. Currently, the proposed strategies for dispositioning are (a) aqueous dissolution and down blending to LEU via facilities at SRS followed by shipment of the liquid LEU to NFS for fabrication into LWR fuel for the TVA reactors and (b) dilution of the HEU to 0.9% for discard as a waste stream that would no longer have a criticality or proliferation risk without being processed through some type of enrichment system. Dispositioning this inventory as a waste stream via aqueous processing at SRS has been determined to be too costly. Thus, dry blending is the only proposed disposal process for the uranium oxide materials in the CPP-651 vault. Isotopic dilution of HEU to typically less than 20% by dry blending is the key to solving the dispositioning issue (i.e., proliferation) posed by HEU stored at INEEL. RM-2 mill is a technology developed and successfully tested for producing ultra-fine particles by dry grinding. Grinding action in RM-2 mill produces a two million-fold increase in the number of particles being blended in a centrifugal field. In a previous study, the concept of achieving complete and adequate blending and mixing (i.e., no methods were identified to easily separate and concentrate one titanium compound from the other) in remarkably short processing times was successfully tested with surrogate materials (titanium dioxide and titanium mono-oxide) with different particle sizes, hardness and densities. In the current project, the RM-2 milling technology was thoroughly tested with mixtures of natural uranium oxide (NU) and depleted uranium oxide (DU) stock to prove its performance. The effects of mill operating and design variables on the blending of NU/DU oxides were evaluated. First, NU and DU both made of the same oxide

  20. NUCLEAR ISOTOPIC DILUTION OF HIGHLY ENRICHED URANIUM BY DRY BLENDING VIA THE RM-2 MILL TECHNOLOGY

    DOE has initiated numerous activities to focus on identifying material management strategies to disposition various excess fissile materials. In particular the INEEL has stored 1,700 Kg of offspec HEU at INTEC in CPP-651 vault facility. Currently, the proposed strategies for dispositioning are (a) aqueous dissolution and down blending to LEU via facilities at SRS followed by shipment of the liquid LEU to NFS for fabrication into LWR fuel for the TVA reactors and (b) dilution of the HEU to 0.9% for discard as a waste stream that would no longer have a criticality or proliferation risk without being processed through some type of enrichment system. Dispositioning this inventory as a waste stream via aqueous processing at SRS has been determined to be too costly. Thus, dry blending is the only proposed disposal process for the uranium oxide materials in the CPP-651 vault. Isotopic dilution of HEU to typically less than 20% by dry blending is the key to solving the dispositioning issue (i.e., proliferation) posed by HEU stored at INEEL. RM-2 mill is a technology developed and successfully tested for producing ultra-fine particles by dry grinding. Grinding action in RM-2 mill produces a two million-fold increase in the number of particles being blended in a centrifugal field. In a previous study, the concept of achieving complete and adequate blending and mixing (i.e., no methods were identified to easily separate and concentrate one titanium compound from the other) in remarkably short processing times was successfully tested with surrogate materials (titanium dioxide and titanium mono-oxide) with different particle sizes, hardness and densities. In the current project, the RM-2 milling technology was thoroughly tested with mixtures of natural uranium oxide (NU) and depleted uranium oxide (DU) stock to prove its performance. The effects of mill operating and design variables on the blending of NU/DU oxides were evaluated. First, NU and DU both made of the same oxide

  1. Measurements of /sup 234/U, /sup 238/U and /sup 230/Th in excreta of uranium-mill crushermen

    Fisher, D.R.; Jackson, P.O.; Brodacynski, G.G.; Scherpelz, R.I.

    1982-07-01

    Uranium and thorium levels in excreta of uranium mill crushermen who are routinely exposed to airborne uranium ore dust were measured. The purpose was to determine whether /sup 230/Th was preferentially retained over either /sup 234/U or /sup 238/U in the body. Urine and fecal samples were obtained from fourteen active crushermen with long histories of exposure to uranium ore dust, plus four retired crushermen and three control individuals for comparison. Radiochemical procedures were used to separate out the uranium and thorium fractions, which were then electroplated on stainless steel discs and assayed by alpha spectrometry. Significantly greater activity levels of /sup 234/U and /sup 238/U were measured in both urine and fecal samples obtained from uranium mill crushermen, indicating that uranium in the inhaled ore dust was cleared from the body with a shorter biological half-time than the daughter product /sup 230/Th. The measurements also indicated that uranium and thorium separate in vivo and have distinctly different metabolic pathways and transfer rates in the body. The appropriateness of current ICRP retention and clearance parameters for /sup 230/Th in ore dust is questioned.

  2. Correlation between gamma radiation levels and soil radium concentrations at the Edgemont uranium mill site

    The Tennessee Valley Authority's uranium mill in Edgemont, South Dakota is being decommissioned. Approximately 4 million tons of contaminated tailings, building equipment, and contaminated soil and debris on the mill site will be removed to the disposal site located approximately 3 kilometers to the southeast. To minimize recontamination of cleaned areas, tailings removal will progress from the northwest corner to the southeast corner of the mill site. As specific areas are cleaned, surveys will be conducted to determine if the concentrations of radium-226 in soil are within the limits outlined in 40 CFR, Part 192. Conformance with the criteria will be demonstrated by a gamma survey of the area employing the differential, or delta-measurement, technique. This technique involves fitting the detector with a base and a receptacle for a removable high-density filter. By making measurements with and without the filter in place, a gamma radiation level proportional to the radium-226 concentration in soil can be determined. This paper describes the results obtained in the development of the correlation between the gamma survey measurements and the soil radium concentrations

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

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

  4. Summary of the engineering assessment of inactive uranium mill tailings, Durango Site, Durango, Colorado

    Ford, Bacon and Davis Utah Inc. has reevaluated the Durango site in order to revise the November 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Durango, Colorado. This engineering assessment has included the preparation of topographic measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the nearly 1.6 million tons of tailings at the Durango site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The four alternative actions presented in this engineering assessment range from millsite and off-site decontamination with the addition of 3 m of stabilization cover material (Option I), to removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II through IV). Cost estimates for the seven options range from about $10,700,000 for stabilization in-place, to about $21,800,000 for disposal at a distance of about 10 mi. Three principal alternatives for the reprocessing of the Durango tailings were examined: (a) heap leaching; (b) treatment at an existing mill; and (c) reprocessing at a new conventional mill constructed for tailings reprocessing

  5. Quality assurance program plan for the Radiological Survey Activities Program - Uranium Mill Tailings Remedial Action Project

    The Radiological Survey Activities (RASA) program at Oak Ridge National Laboratory (ORNL) is responsible for surveying designated sites in the vicinity of 24 inactive mill sites involved in the Department of Energy's (DOE) Uranium Mill Tailings Remedial Action Project (UMTRAP). The purpose of these surveys is to provide a recommendation to DOE whether to include or exclude the site from UMTRAP based on whether the onsite residual radioactive material (if any) originated from the former mill sites, and radiation levels onsite are in excess of appropriate Environmental Protection Agency (EPA) criteria. This report describes the quality assurance program plan for the RASA program in conducting all activities related to the UMTRA project. All quality assurance provisions given by the DOE, DOE/UMTRA, and ORNL organizations are integrated into this plan. Specifically, this report identifies the policies and procedures followed in accomplishing the RASA/UMTRAP QA program, identifies those organizational units involved in the implementation of these procedures, and outlines the respective responsibilities of those groups

  6. The effects of column dimensions on uranium mill tailings leach curves

    Experiments were conducted using different sized columns filled with uranium mill tailings and leached with laboratory-prepared groundwater. The data generated were used to evaluate the effects of length-to-diameter ratios on leach curves. These different column sizes and flow rates provided: 1) different solutions/solid contact times (residence times) and 2) different column volumes (scaling) and thus allowed us to address the question, Can laboratory results be scaled up to apply to real world disposal conditions. The results showed that the leach curves were similar for all the columns (no matter what the residence time or size) for all elements except chloride and calcium. The general shape of the leach curves for each constituent versus effluent volume was a rapidly decreasing curve from very high concentrations down to the groundwater concentration within about four to six pore volumes. Chloride elution was affected by mechanical dispersion, causing effluent concentrations to reach influent concentrations sooner for the columns with longer residence times. The calcium concentrations remained nearly constant or only slightly decreased over the duration of the experiments and were assumed to be controlled by the dissolution of gypsum. Aside from the chloride data, over the range of residence times and scaling factors studied, we conclude that laboratory data on uranium mill tailins leaching can be used to predict long-term movement of contaminants from actual tailings impoundments. The main reactions that control contaminant leaching from tailings are the displacement of residual mill process liquor and the redissolution of readily soluble evaporites and moderately soluble gypsum. These processes occur quite rapidly and therefore laboratory experiments with relatively short residence times are still accurate; i.e., lab residence times are long enough to transcend any short-term kinetic effects that could lead to erroneous predictions

  7. Laboratory measurements of contaminant attenuation of uranium mill tailings leachates by sediments and clay liners

    We discuss FY82 progress on the development of laboratory tools to aid in the prediction of migration potential of contaminants present in acidic uranium mill tailings leachate. Further, empirical data on trace metal and radionuclide migration through a clay liner are presented. Acidic uranium mill tailings solution from a Wyoming mill was percolated through a composite sediment called Morton Ranch Clay liner. These laboratory columns and subsequent sediment extraction data show: (1) As, Cr, Pb, Ag, Th and V migrate very slowly; (2) U, Cd, Ni, Zn, Fe, Mn and similar transition metals are initially immobilized during acid neutralization but later are remobilized as the tailings solution exhausts the clay liner's acid buffering capacity. Such metals remain immobilized as long as the effluent pH remains above a pH value of 4 to 4.5, but they become mobile once the effluent pH drops below this range; and (3) fractions of the Se and Mo present in the influent tailings solution are very mobile. Possible controlling mechanisms for the pH-dependent immobilization-mobilization of the trace metals are discussed. More study is required to understand the controlling mechanisms for Se and Mo and Ra for which data were not successfully collected. Using several column lengths (from 4.5 to 65 cm) and pore volume residence times (from 0.8 to 40 days) we found no significant differences in contaminant migration rates or types and extent of controlling processes. Thus, we conclude that the laboratory results may be capable of extrapolation to actual disposal site conditions

  8. Laboratory measurements of contaminant attenuation of uranium mill tailings leachates by sediments and clay liners

    Serne, R.J.; Peterson, S.R.; Gee, G.W.

    1983-04-01

    We discuss FY82 progress on the development of laboratory tools to aid in the prediction of migration potential of contaminants present in acidic uranium mill tailings leachate. Further, empirical data on trace metal and radionuclide migration through a clay liner are presented. Acidic uranium mill tailings solution from a Wyoming mill was percolated through a composite sediment called Morton Ranch Clay liner. These laboratory columns and subsequent sediment extraction data show: (1) As, Cr, Pb, Ag, Th and V migrate very slowly; (2) U, Cd, Ni, Zn, Fe, Mn and similar transition metals are initially immobilized during acid neutralization but later are remobilized as the tailings solution exhausts the clay liner's acid buffering capacity. Such metals remain immobilized as long as the effluent pH remains above a pH value of 4 to 4.5, but they become mobile once the effluent pH drops below this range; and (3) fractions of the Se and Mo present in the influent tailings solution are very mobile. Possible controlling mechanisms for the pH-dependent immobilization-mobilization of the trace metals are discussed. More study is required to understand the controlling mechanisms for Se and Mo and Ra for which data were not successfully collected. Using several column lengths (from 4.5 to 65 cm) and pore volume residence times (from 0.8 to 40 days) we found no significant differences in contaminant migration rates or types and extent of controlling processes. Thus, we conclude that the laboratory results may be capable of extrapolation to actual disposal site conditions.

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

    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

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

    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.

  11. An Aerial Radiological Survey of Abandoned Uranium Mines in the Navajo Nation

    Aerial radiological surveys of forty-one geographical areas in the Navajo Nation were conducted during the period of October 1994 through October 1999. The surveys were conducted at the request of the U.S. Environmental Protection Agency (EPA) Region 9 and were performed by personnel of the Remote Sensing Laboratory (RSL) located in Las Vegas, Nevada, a facility of the U.S. Department of Energy, National Nuclear Security Administration Nevada Operations Office. The aerial survey and subsequent processing characterized the overall radioactivity levels and excess bismuth 214 activity (indicator of uranium ore deposits and/or uranium mines) within the surveyed areas. A total of 772,000 aerial gamma spectra and associated position parameters were obtained and analyzed during the multi-year operation. The survey determined that only 15 square miles (39 square kilometers) of the 1,144 square miles (2,963 square kilometers) surveyed (approximately 1.3 %) had excess bismuth indications above the minimum reportable activity, thus reducing the area requiring further investigation by a nominal factor of 76. Radiation contour data files, produced by RSL, were converted to Geographic Information System-compatible digital files and provided to EPA and EPA contractors for inclusion in numerous reports and graphics products

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

    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

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

    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.

  14. Environmental impact assessment for uranium mine, mill and in situ leach projects

    Environmental impact assessments and/or statements are an inherent part of any uranium mining project and are a prerequisite for the future opening of an exploitation and its final closure and decommissioning. Since they contain all information related to the physical, biological, chemical and economic condition of the areas where industrial projects are proposed or planned, they present invaluable guidance for the planning and implementation of environmental mitigation as well as environmental restoration after the mine is closed. They further yield relevant data on the socio-economic impacts of a project. The present report provides guidance on the environmental impact assessment of uranium mining and milling projects, including in situ leach projects which will be useful for companies in the process of planning uranium developments as well as for the regional or national authorities who will assess such developments. Additional information and advice is given through environmental case histories from five different countries. Those case histories are not meant to be prescriptions for conducting assessments nor even firm recommendations, but should serve as examples for the type and extent of work involved in assessments. A model assessment and licensing process is recommended based on the experience of the five countries

  15. Selenium accumulation in aquatic biota downstream of a uranium mining and milling operation

    Uranium mining and milling operations have the potential to release trace elements such as arsenic, molybdenum, nickel, selenium and uranium and ions (e.g., sulfate, ammonium) into the receiving aquatic ecosystem. The major implication of elevated environmental selenium is its propensity to accumulate in the aquatic food chain, potentially impairing fish reproduction. The objective of this study was to investigate the accumulation of selenium in the major compartments of aquatic ecosystems (lakes) upstream and downstream of a uranium mine in northern Saskatchewan, Canada. Selenium concentrations in aquatic biota were elevated in the exposure lake although water and sediment concentrations were low (0.43 μg/L and 0.54 μg/g dry weight, respectively). Biomagnification of selenium resulted in approximately 1.5 to 6 fold increase in the selenium concentration between plankton, invertebrates and fish. However, no biomagnification was observed between forage and predatory fish. Although some aquatic biota (e.g., forage fish) exceeded the lower limit of the proposed 3 to 11 μg/g (dry weight) dietary toxicity threshold for fish, no adverse effects of selenium could be identified in this aquatic system. Continued environmental monitoring is recommended to avoid potential selenium impacts

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

    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, building foundations, and materials associated with the former processing of uranium ore at UMTRA Project sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further contamination of ground water. One UMTRA Project site is near Maybell, Colorado. Surface cleanup at this site began in 1995 and is scheduled for completion in 1996. The tailings are being stabilized in place at this site. The disposal area has been withdrawn from public use by the DOE and is referred to as the permanent withdrawal area. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from past uranium ore processing activities. The Ground Water Project at this site is in its beginning stages. This report is a site-specific document that will be used to evaluate current and future potential impacts to the public and the environment from exposure to contaminated ground water. The results presented in this document and other evaluations will determine whether any action is needed to protect human health or the environment

  17. SSH gene expression profile of Eisenia andrei exposed in situ to a naturally contaminated soil from an abandoned uranium mine.

    Lourenço, Joana; Pereira, Ruth; Gonçalves, Fernando; Mendo, Sónia

    2013-02-01

    The effects of the exposure of earthworms (Eisenia andrei) to contaminated soil from an abandoned uranium mine, were assessed through gene expression profile evaluation by Suppression Subtractive Hybridization (SSH). Organisms were exposed in situ for 56 days, in containers placed both in a contaminated and in a non-contaminated site (reference). Organisms were sampled after 14 and 56 days of exposure. Results showed that the main physiological functions affected by the exposure to metals and radionuclides were: metabolism, oxireductase activity, redox homeostasis and response to chemical stimulus and stress. The relative expression of NADH dehydrogenase subunit 1 and elongation factor 1 alpha was also affected, since the genes encoding these enzymes were significantly up and down-regulated, after 14 and 56 days of exposure, respectively. Also, an EST with homology for SET oncogene was found to be up-regulated. To the best of our knowledge, this is the first time that this gene was identified in earthworms and thus, further studies are required, to clarify its involvement in the toxicity of metals and radionuclides. Considering the results herein presented, gene expression profiling proved to be a very useful tool to detect earthworms underlying responses to metals and radionuclides exposure, pointing out for the detection and development of potential new biomarkers. PMID:23164450

  18. Licensing process for a uranium ore mining and milling facilities located in the state of Bahia, Brazil

    The Uranium Concentrate Plant – URA – is a plant engaged in uranium ore research, mining and milling activities. The plant aims at producing natural uranium concentrate in the form of ammonium diuranate – ADU, used as raw material for fuel production for nuclear plants. This paper discusses the aspects related to nuclear installation licensing, featuring all steps of the process and emphasizing the requirements of control agencies. It also approaches the epidemiological study required by IBAMA during the process of environment licensing, in order to define possible influences of URA's activities on the neighboring population’s health. (author)

  19. Experience in the transport and disposal of uranium mill tailings from Aldama City to Sierra Pena Blanca in Chihuahua, Mexico

    In the process of decontamination, transport and disposal of uranium mill tailings, in the state of Chihuahua, Mexico, was necessary the multidisciplinary and multi institutional task to select mainly the site for the final disposal. The uranium mill tailings content Ra-226 which half live time is 1600 years, therefore the site should be adequately stable, a remote place of population, and which containment will survive for thousand of years. The decontamination of site where the uranium mill tailings were 25 years ago, required the application of norms from regulator organism. For the transport of uranium mill tailings was necessary that the vehicles had devices to reduce the dispersion of material in the road. The selection of the site was product of balance between the cost of transport and the final disposal. To typify the site, studies of hydrology, meteorology, ecology, geology and seismology were performed. On the other hand, the decision to locate the deposit in the site was due to dispersion of material by the rain, wind and bowls. (authors). 3 refs., 1 fig., 1 tab

  20. Radioecological investigations of uranium-mill-tailings systems. Fourth technical progress report, October 1, 1982-September 30, 1983

    This document provides a status report on studies which address some of the problems and questions on the integrity and transport of several radionuclides in active and reclaimed uranium mill tailings. The studies reported are being conducted at the Shirley Basin Uranium Mine, located in southeastern Wyoming. The investigation quantitatively evaluates the potential release of important radionuclides from active and reclaimed uranium mill tailings and their entry into the food chain. For active mill tailings, we are trying to quantify the degree of escape and dispersal, primarily by wind, and to measure the accumulation of 238U, 230Th, 226Ra, 210Pb and 210Po by various native plants. Of particular interest are the relationships between soil and vegetation at different sites, since the chemical environment of areas impacted by mill tailings are drastically different than undisturbed natural areas. Also of great interest, is the relative importance of various mechanisms of radionuclide accumulation by plants, such as root uptake and aerial deposition, followed by some degree of foliar absorption. This investigation includes as a major component, studies relating to the final disposal of mill tailings. Experiments on radon flux versus overburden depth showed that tailings covered with 1.5m of revegetated or 0.3m of bare overburden had exhalation rates comparable to background. A positive correlation was demonstrated between precipitation and radon flux

  1. Miscellaneous data and information collected during radiation surveys at the former Monument Uranium Mill site (1974--1975). Technical note

    The purpose of the surveys was to delineate the spread and depth of ore and mill tailings in order that cost estimates could be made for their removal and interim stabilization of the tailings piles. The results of the surveys were prepared in summary form and very little data was made available. This report presents the data and information collected at the former Monument Uranium Mill site. The data includes gamma radiation background measurements, bore hole logging data, ground water analysis, gamma surveys, and radionuclide concentrations versus depth in soil. Interpretation of the data is made where possible. It appears, from bore hole logs, that a substantial amount of uranium is still present at the mill site

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

    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

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

    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.

  4. Technologies for the treatment of effluents from uranium mines, mills and tailings. Proceedings of a technical committee meeting

    Effluent treatment is an important aspect of uranium mining and milling operations that continues through decommissioning and site rehabilitation. During the life of a mine, effluent treatment is an integral part of the operation with all effluent either being recycled to the mill or processed through a water treatment plant before being released into the environment. During decommissioning and rehabilitation, effluent treatment must continue either through a water treatment plant of by using passive treatment techniques. Because of the recent closing of several uranium mines or mining districts, particularly in eastern Europe, effluent treatment is becoming an ever increasing concern. Therefore the IAEA convened a technical committee meeting (TCM) so that experts from different countries could discuss information and knowledge on effluent treatment processes and methods. The papers presented at the meeting describe techniques for treatment of effluents from uranium production operations - both past and present. This publication contains ten papers presented at the meeting; each of the papers was indexed separately

  5. Uranium speciation in the environment: study of opals from Nopal I (Mexico) and mill tailings from Gunnar (Canada)

    Understanding the processes of uranium migration and sequestration is an important issue for the prediction of radionuclide retardation in the vicinity of uranium mine tailings sites or for the safety assessment of potential high-level nuclear waste repositories. Uranium speciation, controlled by biotic and abiotic factors, represents a key parameter for the control of uranium transfer in the environment. This study firstly deals with uranium speciation in opals from the Nopal I uranium deposit (Mexico). Microscopic observations of opals at the nano-scale revealed the occurrence of vorlanite, cubic CaUO4. This was the first time this rare calcium uranate has been found displaying a cubic morphology, in agreement with its crystal structure. Nopal I opals have been further investigated through time-resolved laser fluorescence spectroscopy. The opals spectra and their comparison with those of experimentally produced standards indicate occurrence of mono- or polymeric uranyl complexes (associated or not with calcium or phosphate) sorbed onto internal surface of opal around pH 7-8. Finally, the speciation of uranium was studied in mill tailings from Gunnar (Canada). In the first tailings site, uranium primarily occurs as monomeric, inner-sphere uranyl complexes sharing edges with Fe(O,OH)6 octahedral sites of iron-oxy-hydroxides and chlorite. Our results suggested that U(VI) co-precipitates with iron (oxy-hydr)oxides predominate in the second tailings sites. Therefore uranium mobility in Gunnar is governed by sorption/desorption and dissolution/(co)precipitation processes. (author)

  6. Assessment of cover systems at the Grand Junction, Colorado, uranium mill tailings pile: 1987 field measurements

    Four Pacific Northwest Laboratory (PNL) scientists and a technician conducted an onsite evaluation of radon gas exhalation, water content profiles, and plant and animal intrusion for a series of cover systems located on the uranium mill tailings pile at Grand Junction, Colorado. These six plots were sampled extensively down to the radon control layer (e.g., asphalt or wet clay) for soil moisture content and permeability. Radon gas emission through the surface was measured. Soil samples were collected and analyzed in the lab for particle-size distribution, particle density, bulk density, and ambient water content. Prairie dog burrows were excavated to discover the extent to which they penetrated the barriers. Plant type, density, and cover characteristics were measured

  7. Engineering assessment of inactive uranium mill tailings, Green River Site, Green River, Utah

    Ford, Bacon and Davis Utah Inc. has reevaluated the Green River site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Green River, Utah. This evaluation has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative remedial actions. Radon gas released from the 123,000 tons of tailings at the Green River site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors

  8. A feasibility study of geomorphic research for the long term management of uranium mill tailings

    This report provides a plan for geomorphic research needed for proper long-term management of mill tailings from the Ranger uranium mine in the Northern Territory of Australia. The proposed research will provide information about both the risk of above-grade disposal of the tailings and the implications of the escape of tailings from containment structure. The proposed research includes the description of, documentation of behaviour of, and the identification of controlling external forces on, the geomorphic system both at the mine site and in a much larger area likely to be affected by escaped tailings. While designed for the Ranger site, the principles embodied in this report are applicable to many problems of mine waste disposal

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

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

  10. Assessment of the radiological impact of the inactive uranium-mill tailings at Shiprock, New Mexico

    Uranium-mill tailings at an inactive site near Shiprock, New Mexico, contain an estimated 950 curies (Ci) of 226Ra together with its radioactive daughters. A radiological survey was conducted at this site in February 1976. Decontamination work and tailings stabilization performed at the site since that time have greatly changed conditions there and little effort was applied to quantification of potential health effects in comparison to the earlier consideration of the site at Salt Lake City. The present report delineates the radiological conditions that existed at the time of the survey including information on the surface and below-surface distribution of 226Ra. The data presented support the conclusion that diffusion of radon and inhalation of radon daughters is the principal mode of exposure of offsite population groups

  11. Regulatory philosophy and requirements for radiation control in Canadian uranium mine-mill facilities

    The approach the Canadian Atomic Energy Control Board takes in licensing uranium mine/mill facilities is based on a minimum of rigidly set regulatory requirements. The regulations state only the basic objectives: the obligation to acquire a licence, some administrative and reporting requirements, and exposure limits. The regulations are supported by a set of regulatory guides. The operator always has the option of following different procedures if he can demonstrate that they will produce the same or better results. Good relationships exist between the AECB and mine management as well as trade unions. Under this approach, however, it is difficult to take action against uncooperative parties. The Board has decided that a somewhat more formalized system is necessary. New regulations are being drafted, giving more detailed licensing and administrative requirements and covering the areas of ventilation and worker and supervisor education more thoroughly

  12. Revegetation/rock cover for stabilization of inactive uranium mill tailings disposal sites

    Pacific Northwest Laboratory is developing design and performance guidelines for surface stabilization of inactive uranium mill tailings. In this work, vegetation and rock covers are being evaluated for maintaining long-term integrity of impoundment systems. Methods are being developed to estimate erosion rates associated with rock and/or vegetation covers, and to determine the effects of surface treatments on soil moisture. Interactions between surface treatments and barriers (radon and biological) are being studied as well. The product will be a set of guidelines to aid in designing surface covers. This report presents the status of this program and a discussion of considerations pertinent to the application of surface covers to tailings. Test plots located in Grand Junction, Colorado and Waterflow, New Mexico are being used to study: (1) the interactions between vegetation and radon and biological barriers, (2) the effects of surface covers on soil moisture, and (3) the effects of rock covers on vegetation

  13. Engineering assessment of inactive uranium mill tailings, Green River Site, Green River, Utah

    None

    1981-08-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Green River site in order to revise the December 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Green River, Utah. This evaluation has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative remedial actions. Radon gas released from the 123,000 tons of tailings at the Green River site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.

  14. Engineering assessment of inactive uranium mill tailings, Tuba City site, Tuba City, Arizona

    1981-09-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Tuba City site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Tuba City, Arizona. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 0.8 million tons of tailings at the Tuba City site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.

  15. Performance of asphalt and clay liners as a uranium mill tailings leachate barrier

    Pacific Northwest Laboratory is evaluating the long-term effectiveness of various asphalt and clay liner materials as a radionuclide and process chemical barrier from uranium mill tailings. A field test is being conducted by monitoring asphalt and clay liners installed at the Grand Junction, Colorado tailings site. In addition eight prospective liners have undergone three months exposure to accelerated conditions to predict their behavior over a 1000 year period. High calcium leachates have been forced through thin layers of clay to determine the ability of the clay to resist ion exchange, which reduces its swelling capabilities. Asphalt liners have been exposed to elevated temperatures and increased strengths of oxidizing agents to accelerate their aging process. The permeability coefficients measured during this exposure were then used to predict each liners stability with time. The analyses thus far show that clay soils with bentonite amendments and most asphalt compositions have good long-term performance characteristics. 3 figures, 1 table

  16. Performance of asphalt and clay liners as a uranium mill tailings leachate barrier

    Pacific Northwest Laboratory is evaluating the long-term effectiveness of various asphalt clay liner materials as a radionuclide and process chemical barrier from uranium mill tailings. A field test is being conducted by monitoring asphalt and clay liners installed at the Grand Junction, Colorado tailings site. In addition, eight prospective liners have undergone three months exposure to accelerated conditions to predict their behavior over a 1000-year period. High-calcium leachates have been forced through thin layers of clay to determine the ability of the clay to resist ion exchange, which reduces its swelling capabilities. Asphalt liners have been exposed to elevated temperatures and increased strengths of oxidizing agents to accelerate their aging process. The permeability coefficients measured during this exposure were then used to predict each liners stability with time. The analyses thus far show that clay soils with bentonite amendments and most asphalt compositions have good long-term performance characteristics

  17. A combined modeling program for evaluating the cover design at a uranium mill tailings disposal site

    The authors describe a modeling program for evaluating the performance of a proposed cover at a uranium mill tailings disposal location applied to the site's design. In this application, the volume of leachate from the base of the proposed tailings impoundment was estimated by a fundamental Darcian-style analysis, and with the HELP (Hydrologic Evaluation of Landfill Performance) computer model. The potential impacts to the local ground water regime were assessed initially by diluting the leachate flux, predicted by the HELP model, with the estimated volume of ground water available for dilution. Following this, the potential for leachate attenuation from chemical precipitation was simulated with the geochemical speciation code PHREEQE (pH redox equilibrium equations). The volume and estimated composition of the leachate was mixed with the volume and chemical character of the existing ground water by using the mixing mode of PHREEQE

  18. Radiological survey of the inactive uranium-mill tailings at Durango, Colorado

    Results of a radiological survey of the inactive uranium-mill site at Durango, Colorado, conducted in April 1976, in cooperation with a team from Ford, Bacon and Davis Utah Inc., are presented together with descriptions of the instruments and techniques used to obtain the data. Direct above-ground gamma measurements and analysis of surface soil and sediment samples indicate movement of tailings from the piles toward Lightner Creek on the north and the Animas River on the east side of the piles. The concentration of 226Ra in the former raffinate pond area is only slightly above the background level. Two structures in Durango were found to contain high concentrations of airborne radon daughters, where tailings are known to have been utilized in construction. Near-background concentrations of radon daughters were found in a well-ventilated building close to the tailings

  19. Revegetation/rock cover for stabilization of inactive uranium mill tailings disposal sites

    Beedlow, P.A.; McShane, M.C.; Cadwell, L.L.

    1982-07-01

    Pacific Northwest Laboratory is developing design and performance guidelines for surface stabilization of inactive uranium mill tailings. In this work, vegetation and rock covers are being evaluated for maintaining long-term integrity of impoundment systems. Methods are being developed to estimate erosion rates associated with rock and/or vegetation covers, and to determine the effects of surface treatments on soil moisture. Interactions between surface treatments and barriers (radon and biological) are being studied as well. The product will be a set of guidelines to aid in designing surface covers. This report presents the status of this program and a discussion of considerations pertinent to the application of surface covers to tailings. Test plots located in Grand Junction, Colorado and Waterflow, New Mexico are being used to study: (1) the interactions between vegetation and radon and biological barriers, (2) the effects of surface covers on soil moisture, and (3) the effects of rock covers on vegetation.

  20. Summary of the engineering assessment of inactive uranium mill tailings, Tuba City site, Tuba City, Arizona

    None

    1981-09-01

    Ford, Bacon and Davis Utah Inc. has reevaluated the Tuba City site in order to revise the March 1977 engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Tuba City, Arizona. This engineering assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas released from the 0.8 million tons of tailings at the Tuba City site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors.

  1. Phase II, Title I, engineering assessment of inactive uranium mill tailings, Riverton Site, Riverton, Wyoming

    1977-12-01

    An engineering assessment was performed of the problems resulting from the existence of radioactive uranium mill tailings at the Spook Site, Converse County, Wyoming. Services include the performance of core drillings, soil, water and other sample analyses, radiometric measurements to determine areas with radium-contaminated materials, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site geology, hydrology, and meteorology and the evaluation and costing of alternative corrective actions. Radon gas release from the 187,000 tons of tailings at the Spook Site constitutes the main environmental impact, which is negligible. The two alternative actions presented are better fencing of the site in its present state, and placing tailings and contaminated on-site materials and soil in the open-pit mine and covering the resulting pile with 2 ft of overburden materials. The cost estimates for the options are $81,000 and $142,000, respectively.

  2. Overview of IAEA activities in restoration of former uranium mining and milling sites

    The IAEA has increasingly become concerned with the radiological and environmental impact of closed uranium mining and milling facilities. It is recognized that inappropriate practices in waste management and the lack of closeout plans have lead to environmental hazards and the potential for human exposure worldwide. In many instances the operators or those responsible for radiation and environmental protection lacked the experience in planning and executing remediation and restoration projects. Through a series of technical documents and other means, which are reviewed briefly in this paper, the IAEA strives to provide guidance and examples for the selection and application of adequate remediation technologies and restoration practices. Emphasis is put upon a comprehensive planning process leading to technology selection. This process commences with proper site characterisation on the basis of which a strategy is to be developed and finishes with post-closure monitoring as an integral instrument of quality control and quality assurance. (author)

  3. Environmental assessment related to the operation of Hansen uranium mill project, WM-24, Cyprus Mines Corporation

    An environmental assessment was prepared by the staff of the U.S. Nuclear Regulatory Commission, Office of Nuclear Material Safety and Safeguards, in response to a request for technical assistance from the State of Colorado in connection with licensing action on the proposed Cyprus Mines Corporation, Hansen uranium project. The major components of discussion are (1) a summary and recommended licensing conditions, (2) a description of the site environment and the proposed facility operation as well as alternatives in comparison with NRC's performance objectives for tailings management, and (3) a radiological assessment for estimating the facility's compliance with 10 CFR 20 and 40 CFR 190 dose regulations. The NRC recommends licensing the proposed mill subject to stipulated license conditions

  4. Radon transport from uranium mill tailings via plant transpiration. Final report

    Radon exhalation by vegetation planted on bare or soil-covered uranium mill wastes was studied based on an assumption that radon transport from soil to atmosphere via plants takes place in the transpiration stream. Results show that radon exhalation by plants is inversely related to water transpired, primarily a dilution effect. Radon released appeared directly related to leaf area, suggesting that radon is carried into the plant by mass flow in water; however, once within the plant, radon very likely diffuses through the entire leaf cuticle, while water vapor diffuses primarily through open stomates. Application of a computerized model for water transpiration to radon exhalation is not immediately useful until the role of water in radon transport is defined throughout the continuum from rooting medium to the atmosphere. Until then, a simple calculation based on leaf area index and Ra-226 concentration in the rooting medium can provide an estimate of radon release from revegetated wastes containing radium

  5. Radiological survey of the inactive uranium-mill tailings at Gunnison, Colorado

    The findings of a radiological survey of the inactive uranium-mill site at Gunnison, Colorado, conducted in May 1976, are presented. Results of surface soil sample analyses and direct gamma radiation measurements indicate limited spread of tailings off the site. The only significant above background measurements off the site were obtained in an area previously covered by the tailings pile. There was little evidence of contamination of the surface or of unconfined groundwater in the vicinity of the tailings pile; however, the hydrologic conditions at the site indicate a potential for such contamination. The concentration of 226Ra in all water samples except one from the tailings pile was well below the concentration guide for drinking water. The subsurface distribution of 226Ra in 14 bore holes located on and around the tailings pile was calculated from gamma ray monitoring data obtained jointly with Ford, Bacon and Davis Utah Inc

  6. Molecular analysis of the bacterial diversity in uranium mill tailings; Molekulare Analyse der bakteriellen Diversitaet in Uranabraumhalden

    Geissler, A.

    2003-04-01

    A culture-independent molecular approach has been applied to investigate the bacterial diversity in three uranium contaminated sites. The three analysed soil samples have been collected from the uranium waste pile Haberland near Johanngeorgenstadt (Germany), from the uranium mill tailings in Gunnison, Colorado (US) and from the uranium mill tailings in Shiprock, New Mexico (US). The 16S rDNA fragments which has been isolated through direct lysis of the whole-DNA were amplified by the use of the universal primers 16S{sub 43f} and 16S{sub 1404r} and cloned. With restriction fragment length polymorphismus (RFLP) were the clones screened and one representative of all RFLP types that occurred more than once in the clone library was sequenced and analysed. In spite of the contamination a considerable diversity and significant differences in the composition of the natural bacterial communities in these three sites have been found. In the sample collected from the waste pile Haberland near Johanngeorgenstadt {alpha}-Proteobacteria and representatives of the Holophaga/Acidobacterium were numerically predominant. The distribution of bacteria in the sample collected from uranium mill tailings Gunnison was very similar to those found in the Haberland waste pile, but there were found besides {alpha}-Proteobacteria and representatives of Holophaga/Acidobacterium a lot of {gamma}-Proteobacteria. The structure of the bacterial community in the sample collected from the uranium mill tailings Shiprock was significantly different. Only some representatives of the Holophaga/Acidobacterium and {alpha}-Proteobacteria were represented. Large populations of Bacilli, {gamma}-Proteobacteria and green non sulfur bacteria were dominant in this sample. (orig.)

  7. Optimum condition determination of Rirang uranium ores grinding using ball mill

    The grinding experiment on Rirang Uranium ore has been carried out with the aim is to find out the optimum condition of wet grinding using ball mill to produce particle size -325, -200 and -100 mesh. This will be used for decomposition feed the test was done by examine the parameters comparison of ore's weight against ball's weight and time of grinding. The test shown that the product of particle size -325 meshes was achieved optimum condition at the comparison ore's weight: ball = 1:3, grinding time 150 minutes, % solid 60, speed rotation of ball mill 60 rpm and recovery of grinding was 93.51 % of -325 mesh. The product of particle size -200 mesh was achieved optimum condition at comparison ore's weight: ball = 1:2, time of grinding 60 minutes, the fraction of + 200 mesh was regrind, the recovery of grinding 6.82% at particle size of (-200 + 250) mesh, 5.75 % at (-250 + 325)m mesh and, 47.93 % -325 mesh. The product of particle size -100 mesh was achieved the optimum condition at comparison ore's weight: ball = 1:2, time of grinding at 30 minutes particle size +100 mesh regrinding using mortar grinder, recovery of grinding 30.10% at particle size (-100 + 150) m, 12.28 % at (-150 + 200) mesh, 15.92 % at (-200 + 250) mesh, 12.44 % at (-250 + 325) mesh and 29.26 % -325 mesh. The determination of specific gravity of Rirang uranium ore was between 4.15 - 4.55 g/cm3

  8. Development of a new process for radium removal from uranium mining and milling effluents

    This paper describes the on-going pilot scale development of a new treatment process designed to remove radium-226 from uranium milling effluents. Presently, decants from Canadian uranium mining and milling tailings areas are treated with barium chloride to remove radium-226 prior to discharge into the environment. This is usually accomplished in large natural or man-made ponds which provide an opportunity for a (Ba,Ra)SO/sub 4/ precipitate to form and subsequently settle. At some treatment facilities sand filtration is used as a polishing step. The new process involves the use of a fluidized bed to facilitate the deposition of a (Ba,Ra)SO/sub 4/ precipitate on a free-draining granular medium of high surface area. Incoming radium-226 activity levels have consistently been reduced by 90-99% and effluent levels of 0.37 Bq/L (10 pCi/L) or less have been achieved, depending on the influent activity levels. Testing of the process as a polishing step demonstrated radium removal efficiencies up to 60% when the process influent was already less than 0.19 Bq/L (5 pCi/L). The process has been operated at temperatures ranging from 260C down to 0.30C with no reduction in efficiency. In contrast to treatment times in the order of days for conventional settling pond systems and hours for mechanical stirred tank/filtration systems, the new process is able to achieve these radium removal efficiencies in times on the order of one minute

  9. Relationship Between 210Pb Concentrations in Solid Wastes and Plants from Uranium Mill Tailings

    Full text: The exploitation and treatment of uranium ore at the Urgeirica mine (north of Portugal) have led to the accumulation of large amounts of soild wastes (mill tailings) in dams (tailing ponds). These solid wastes containing natural radionuclides could be dispersed by the action of atmospheric agents and contaminate the environment. To minimize the dispersion of these radionuclides into the environment the dams were revegetated with pines (Pinus pinea) and eucalyptes (Eucalyptus globolus). The objective of this study is to know the 210Pb behaviour in what concerns its transfer from the uranium mill tailings to these plants, through the analysis of relationships between 210Pb concentrations in the solid wastes and the plants. Solid wastes and plant samples were randomly collected at the dams and the 210Pb activity concentration in solid wastes and plant (aerial part and roots) samples were determined by gamma spectrometry. The results obtained for pines show a good correlation between 210Pb concentrations in the solid wastes and roots. No correlation was found to 210Pb concentrations in the solid wastes and needles. The 210Pb concentration data for eucalyptes show a quite good correlation between 210Pb concentrations in the solid wastes and leaves. Concentration ratio data, solid wastes/roots and solid wastes/needles for pines are on the same order of magnitude. The 210Pb uptake by pines (roots and needles) and eucalyptes (leaves) show that 210Pb concentration ratios decrease at low 210Pb concentrations in the solid wastes and appear relatively constant at higher 210Pb concentrations in the solid wastes. Data presented for 210Pb in this paper, will be compared with those obtained for 226Ra on the same samples. (author)

  10. The regulatory process for uranium mines in Canada -general overview and radiation health and safety in uranium mine-mill facilities

    This presentation is divided into two main sections. In the first, the author explores the issues of radiation and tailings disposal, and then examines the Canadian nuclear regulatory process from the point of view of jurisdiction, objectives, philosophy and mechanics. The compliance inspection program is outlined, and the author discussed the relationships between the AECB and other regulatory agencies, the public and uranium mine-mill workers. The section concludes with an examination of the stance of the medical profession on nuclear issues. In part two, the radiological hazards for uranium miners are examined: radon daughters, gamma radiation, thoron daughters and uranium dust. The author touches on new regulations being drafted, the assessment of past exposures in mine atmospheres, and the regulatory approach at the surface exploration stage. The presentation concludes with the author's brief observations on the findings of other uranium mining inquiries and on future requirements in the industry's interests

  11. Engineering assessment of inactive uranium mill tailings: Lakeview site, Lakeview, Oregon

    This assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The three alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material (Option I) and removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II and III). Cost estimates range from about $6,000,000 for stabilization in-place, to about $7,500,000 for disposal at a distance of about 10 miles. Three alternatives for reprocessing the Lakeview tailings were examined: heap leaching, treatment at an existing mill, and reprocessing at a new conventional mill. The cost of the uranium recovered would be over $450/lb of U3O8 and hence reprocessing is not economical

  12. Intrusion of soil covered uranium mill tailings by whitetail prairie dogs and Richardson's ground squirrels

    The primary objective of the reclamation of uranium mill tailings is the long-term isolation of the matrial from the biosphere. Fossorial and semi-fossorial species represent a potentially disruptive influence as a result of their burrowing habits. The potential for intrusion was investigated with respect to two sciurids, the whitetail prairie dog (Cynomys leucurus) and Richardson's ground squirrel (Spermophilus richardsonii). Populations of prairie dogs were established on a control area, lacking a tailings layer, and two experimental areas, underlain by a waste layer, in southeastern Wyoming. Weekly measurements of prairie dog mound surface activities were conducted to demonstrate penetration, or lack thereof, of the tailings layer. Additionally, the impact of burrowing upon radon flux was determined. Limited penetration of the waste layer was noted after which frequency of inhabitance of the intruding burrow system declined. No significant changes in radon flux were detected. In another experiment, it was found that Richardson's ground squirrels burrowed to less extreme depths when confronted by mill tailings. Additional work at an inactive tailings pile in western Colorado revealed repeated intrusion through a shallow cover, and subsequent transport of radioactive material to the ground surface by prairie dogs. Radon flux from burrow entrances was significantly greater than that from undisturbed ground. Data suggested that textural and pH properties of tailings material may act to discourage repeated intrusion at some sites. 58 references

  13. Engineering assessment of inactive uranium mill tailings: Lakeview site, Lakeview, Oregon

    None

    1981-10-01

    This assessment has included the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and radiation exposures of individuals and nearby populations, the investigations of site hydrology and meteorology, and the evaluation and costing of alternative corrective actions. Radon gas constitutes the most significant environmental impact, although windblown tailings and external gamma radiation also are factors. The three alternative actions presented in this engineering assessment include millsite decontamination with the addition of 3 m of stabilization cover material (Option I) and removal of the tailings to remote disposal sites and decontamination of the tailings site (Options II and III). Cost estimates range from about $6,000,000 for stabilization in-place, to about $7,500,000 for disposal at a distance of about 10 miles. Three alternatives for reprocessing the Lakeview tailings were examined: heap leaching, treatment at an existing mill, and reprocessing at a new conventional mill. The cost of the uranium recovered would be over $450/lb of U/sub 3/O/sub 8/ and hence reprocessing is not economical.

  14. Pyrite Oxidation in Leaching Process of Radionuclides and Heavy Metals from Uranium Mill Tailings

    2002-01-01

    Pyrite is a sensitive mineral in the geological environment, and its oxidation produces an important geochemical and environmental effect on the control of the redox and pH conditions. Column experiment results were used for modeling the geochemical processes in uranium mill tailings under lcaching conditions. Oxidation of pyrite dominates the control of the tailings leaching process. The experimental and modeling results show that the leachate chemistry changes substantially with the decrease in pyrite consumption. In the initial stage of the leaching experiment, the pyrite is consumed several hundred times greater than that in the later stages, for much more oxygen is present in the tailings in the initial stage. As the experiment continues, the tailings is gradually saturated with water and the oxygen concentration greatly decreases and so does pyrite consumption. The experimental and modeling results are useful for the design of mill tailing decommissioning., oxidation process and transport of radioactive nuclides and heavy metals can be constrained by controlling the oxygen concentration of tailings and the infiltration of meteoric water.

  15. Laboratory evaluation of limestone and lime neutralization of acidic uranium mill tailings solution. Progress report

    Experiments were conducted to evaluate a two-step neutralization scheme for treatment of acidic uranium mill tailings solutions. Tailings solutions from the Lucky Mc Mill and Exxon Highland Mill, both in Wyoming, were neutralized with limestone, CaCO3, to an intermediate pH of 4.0 or 5.0, followed by lime, Ca(OH)2, neutralization to pH 7.3. The combination limestone/lime treatment methods, CaCO3 neutralization to pH 4 followed by neutralization with Ca(OH)2 to pH 7.3 resulted in the highest quality effluent solution with respect to EPA's water quality guidelines. The combination method is the most cost-effective treatment procedure tested in our studies. Neutralization experiments to evaluate the optimum solution pH for contaminant removal were performed on the same two tailings solutions using only lime Ca(OH)2 as the neutralizing agent. The data indicate solution neutralization above pH 7.3 does not significantly increase removal of pH dependent contaminants from solution. Column leaching experiments were performed on the neutralized sludge material (the precipitated solid material which forms as the acidic tailings solutions are neutralized to pH 4 or above). The sludges were contacted with laboratory prepared synthetic ground water until several effluent pore volumes were collected. Effluent solutions were analyzed for macro ions, trace metals and radionuclides in an effort to evaluate the long term effectiveness of attenuating contaminants in sludges formed during solution neutralization. Neutralized sludge leaching experiments indicate that Ca, Na, Mg, Se, Cl, and SO4 are the only constituents which show solution concentrations significantly higher than the synthetic ground water in the early pore volumes of long-term leaching studies

  16. Laboratory evaluation of limestone and lime neutralization of acidic uranium mill tailings solution. Progress report

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

    1984-02-01

    Experiments were conducted to evaluate a two-step neutralization scheme for treatment of acidic uranium mill tailings solutions. Tailings solutions from the Lucky Mc Mill and Exxon Highland Mill, both in Wyoming, were neutralized with limestone, CaCO/sub 3/, to an intermediate pH of 4.0 or 5.0, followed by lime, Ca(OH)/sub 2/, neutralization to pH 7.3. The combination limestone/lime treatment methods, CaCO/sub 3/ neutralization to pH 4 followed by neutralization with Ca(OH)/sub 2/ to pH 7.3 resulted in the highest quality effluent solution with respect to EPA's water quality guidelines. The combination method is the most cost-effective treatment procedure tested in our studies. Neutralization experiments to evaluate the optimum solution pH for contaminant removal were performed on the same two tailings solutions using only lime Ca(OH)/sub 2/ as the neutralizing agent. The data indicate solution neutralization above pH 7.3 does not significantly increase removal of pH dependent contaminants from solution. Column leaching experiments were performed on the neutralized sludge material (the precipitated solid material which forms as the acidic tailings solutions are neutralized to pH 4 or above). The sludges were contacted with laboratory prepared synthetic ground water until several effluent pore volumes were collected. Effluent solutions were analyzed for macro ions, trace metals and radionuclides in an effort to evaluate the long term effectiveness of attenuating contaminants in sludges formed during solution neutralization. Neutralized sludge leaching experiments indicate that Ca, Na, Mg, Se, Cl, and SO/sub 4/ are the only constituents which show solution concentrations significantly higher than the synthetic ground water in the early pore volumes of long-term leaching studies.

  17. A case study on the Uranium tailings dam of Pocos de Caldas uranium mining and milling site

    This Annex describes the geochemical processes controlling the mobilisation of heavy metals and radionuclides in the tailings dam of the Pocos de Caldas Uranium Mining and Milling Facility. It was shown that residual pyrite oxidation causes the production of acid drainage that leaches metals and radionuclides from the solid phase. The remediation scheme, application of dry cover on the tailings, was focused on the reduction of oxygen diffusion into the tailings and radon exhalation from the material Three principal final covers designs were taken from the scientific literature aiming to obtain the most adequate performance for the studied situation The designs studied included: (i) a compacted clay liner (CCL); (ii) a composite liner (CL); and (iii) a capillary barrier (CB). Relevant processes investigated were: (i) saturated hydraulic flow; (ii) unsaturated hydraulic flow (only for the capillary barrier); and (iii) radon exhalation to atmosphere. The computer models utilized for the analyses were: (i) the program Hydrologic Evaluation of Landfill Performance (HELP); (ii) the program SEEP/W; and (iii) the program RADON. (author)

  18. Commingled uranium-tailings study. Volume I. Plan for stabilization and management of commingled uranium-mill tailings

    This report, prepared in accordance with Section 213 of Public Law 96-540, presents a plan for a cooperative program to provide assistance in the stabilization and management of commingled uranium mill tailings. The report is organized in two volumes, a summary report (Volume I) and a companion technical report (Volume II). Contents of Volume I are: summary; background; amount and condition of the tailings; regulatory requirements; stabilization cost estimates; costsharing alternatives; administrative options and plan implementation; standards and regulations. The DOE recommends that the standards and regulations for tailings stabilization be relaxed and that any program of stabilization be limited to prevention of migration and erosion of the tailings and inadvertent exposure to them. The plan presented here shows the effort and costs that would be incurred if the government were to implement such a plan. The Department makes no recommendation as to the advisability of actually implementing legislation authorizing an assistance program, and stands ready to respond to comments on the plan by Congress, other government agencies, or interested parties

  19. Regulatory Oversight of the Legacy Gunner Uranium Mine and Mill Site in Northern Saskatchewan, Canada - 13434

    As Canada's nuclear regulator, the Canadian Nuclear Safety Commission (CNSC) is responsible for licensing all aspects of uranium mining, including remediation activities at legacy sites. Since these sites already existed when the current legislation came into force in 2000, and the previous legislation did not apply, they present a special case. The Nuclear Safety and Control Act (NSCA), was written with cradle-to- grave oversight in mind. Applying the NSCA at the end of a 'facilities' life-cycle poses some challenges to both the regulator and the proponent. When the proponent is the public sector, even more challenges can present themselves. Although the licensing process for legacy sites is no different than for any other CNSC license, assuring regulatory compliance can be more complicated. To demonstrate how the CNSC has approached the oversight of legacy sites the history of the Commission's involvement with the Gunnar uranium mine and mill site provides a good case study. The lessons learned from the CNSC's experience regulating the Gunnar site will benefit those in the future who will need to regulate legacy sites under existing or new legislation. (authors)

  20. Radon exhalation from uranium mill tailings: Modelisation and in situ validation

    TRACI, a model based on the physical mechanisms governing the radon transport in unsaturated soils, has been developed to evaluate the radon flux density at Uranium Mill Tailings (UMT) covers surface. First, moisture contents in the soil, induced by weather conditions, are calculated. Then, radon concentrations in the air-filled pore space, and radon flux density at the soil surface, are deduced from a transport model which takes account for diffusion and convection in the pore space. To check the hypothesis used in TRACI and the efficiency of cover layers, an in situ study was launched in 1997 with the French uranium mining company, COGEMA. It consists of continuous measurements of moisture contents, suctions, radon concentrations at various depths inside an UMT cover, and flux density at its surface. The first analysis made on in situ observations shows that radon concentrations and flux density, calculated with a steady-state diffusion model using monthly averaged moisture contents, are in good agreement with monthly averaged concentrations and flux density measured. (author)

  1. Management of uranium mill tailing: geochemical processes and radiological risk assessment

    This paper describes the geochemical processes regulating the mobilisation of heavy metals and radionuclides in the tailing dam of the uranium mining and milling facilities of Pocos de Caldas, Brazil. The operational effluent release pollution of surface and groundwater was evaluated by means of monitoring data. The potential environmental impact after the future closure of the installation was assessed by means of dose estimations assuming the absence of remedial measures. Residual tailing pyrite oxidation was found to be the critical factor in the transfer of metals and radionuclides to seepage water. No contamination of deep groundwater was observed. On the other hand, the surface water of a nearby river revealed greater uranium concentrations in the tailing dam effluent discharge area than in a background river location sampling station. Lead-210 and 210Po were the principal contributors to the total dose while vegetables were the chief pathways of exposure both for adults and children, to the studied radionuclides after closure. The results of the dose assessment indicate that permanent remedial actions will have to be adopted in the decommissioning phase. (author)

  2. Uranium Mill Tailings Remedial Action Project, fiscal year 1995 annual report to stakeholders

    In 1978, Congress authorized the DOE to assess and clean up contamination at 24 designated former uranium processing sites. The DOE is also responsible for cleaning up properties in the vicinity of the sites where wind and water erosion deposited tailings or people removed them from the site for use in construction or landscaping projects. Cleanup is being undertaken in cooperation with state governments and Indian tribes within whose boundaries the sites are located. It is being conducted in two phases: the surface project and the ground water project. This report addresses specifics about both phases of the UMTRA Project. DOE's UMTRA Project is the world's largest materials management project ever undertaken to reduce or eliminate risk to the general public from exposure to potentially hazardous and radioactive materials. With an estimated cost at completion of nearly $2 billion for both phases of the UMTRA Project, and with the responsibility for encapsulating and isolating almost one-fourth of all the uranium mill tailings generated across the entire US (more than 44 million cubic yards), the UMTRA Project and its people have achieved a long record of safely and effectively completing its mission. It continually enhances its national reputation through its diligent process and cost efficiency as well as its international recognition for its technological innovation

  3. Comparative evaluation of liner materials for inactive uranium-mill-tailings piles

    Under the funding of the Department of Energy's Uranium Mill Tailings Remedial Action (UMTRA) Program, Pacific Northwest Laboratory (PNL) has completed the initial accelerated testing phase of eight candidate liner materials. The tests were designed to comparatively evaluate the long term effectiveness of liner materials as a radionuclide and hazardous chemical leachate barrier. The eight materials tested were selected from a technical review of published literature and industrial specialists. Conditions were then identified that would accelerate the aging processes expected in a uranium tailings environment for 1000 years. High calcium leachates were forced through thin layers of clay liners to accelerate the ion exchange rate of sodium and calcium. Asphalt and synthetic materials were accelerated by exposure to elevate temperatures, high concentrations of oxygen, and increased strengths of aqueous oxidizing agents. By comparing the changes of permeability with time of exposure, the most acceptable materials were then identified. These materials are a catalytically airblown asphalt membrane and natural soil amended with sodium bentonite. Both materials showed an increased resistance to leachate penetration throughout the exposure period with final permeabilities less than 10-7 cm/s. In addition, the asphalt membrane and sodium bentonite are among the least expensive materials to install at a disposal site. Therefore based on their economic and technical merits, these two materials are being evaluated further in field tests at Grand Junction, Colorado

  4. Plans for environmental restoration of uranium mining and milling sites in Bulgaria

    In 1992, uranium mining and milling industry in Bulgaria was closed down by Decree No. 163 of the Council of Ministers of the Republic of Bulgaria which defined the procedure for development of liquidation plans, their approval and the procedure for funding from the national budget. The 1994 Decree No. 56 of the Council of Ministers assigned the organization of the liquidation and rehabilitation activities to the Committee of Energy (later, in 1996, transformed to the Ministry of Energy and Energy Resources). An Interdepartmental Board of Experts including representatives of all concerned ministries and agencies was established to coordinate the above activities and to approve work plans. The main stages of liquidation of the uranium industry and its after-effects were defined as follows: (1) environmental status (maintenance of a minimized service mode in order to preserve the state of the site- environment system); (2) technical liquidation; (3) technical recultivation; (4) biological recultivation; (5) purification of contaminated waters; and (6) monitoring. In 1992 and 1993, preparation for the above activities was carried out by development of detailed preliminary studies and work plans for the first stage - the stage of technical liquidation. Their implementation was launched by evacuation of mining and drilling machinery, haulage and processing of finished products etc. (author)

  5. Background paper for regulations related to the exposure of uranium mine and mill workers

    The Atomic Energy Control Board is modifying the Atomic Energy Control Regulations to include a maximum permissible exposure to radon daughters for uranium mine and mill workers. In January 1976, after consultation with the uranium producers, union, and government regulatory bodies, the AECB issued a directive endorsing a maximum permissible annual occupational exposure to radon daughters of 4 Working Level Months (WLM). This exposure limit was an interim guideline to be applied for at least one year. The Board staff and members of the Mine Safety Advisory Committee have examined available evidence on the excess risk of lung cancer owing to exposure to radon daughters since then, and have assessed the arguments for both raising and lowering the exposure limit. The evidence is still not conclusive, and further studies, especially epidemiological ones, are needed. Nevertheless, the Board considers that the interim guideline is acceptable in the light of the present state of knowledge and that it should be incorporated into the regulations. This document explains why the Board has made this decision and discusses a number of related issues

  6. Engineering assessment of inactive uranium mill tailings, Shiprock site, Shiprock, New Mexico. Phase II, Title I

    1977-03-31

    Ford, Bacon and Davis Utah Inc. has performed an engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Shiprock, New Mexico. The Phase II, Title I services include the preparation of topographic maps, the performance of core drillings and radiometric measurements sufficient to determine areas and volumes of tailings and other radium-contaminated materials, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site hydrology and meteorology and the evaluation and costing of alternative corrective actions. Radon gas release from the 1.7 million tons of tailings at the Shiprock site constitutes the most significant environmental impact, although windblown tailings and external gamma radiation are also factors. The 11 alternative actions presented range from completion of the present ongoing EPA site decontamination plan (Option I), to stabilizing in-place with varying depths of cover material (Options II-IV), to removal to an isolated long-term disposal site (Options V-XI). All options include remedial action costs for off-site locations where tailings have been placed. Costs estimates for the 11 options range from $540,000 to $12,500,000. Reprocessing the tailings for uranium is not economically feasible.

  7. Technico-economic analysis of uranium-mill-tailings conditioning alternatives

    An analysis of practicable conditioning technologies for uranium mill tailings and their estimated costs has been conducted for two conditioning alternatives, thermal stabilization and leaching (sulfuric acid). Among the four high priority remedial action sites, Canonsburg, Pennsylvania, and Shiprock, New Mexico appear to be very good candidates for thermal stabilization. At Shiprock, thermal stabilization appears to be less expensive ($16.01/ton) than moving the pile more than five miles and covering with 15 feet of earth. At Canonsburg costs of other alternatives are not presently available. Given the radiological monitoring and protection expenses attendant upon moving these tailings in a highly populated area, it is likely that thermal stabilization, on site, at $41.25/ton would be an attractive remedial action approach. Cost data on the Salt Lake City, Utah site are presented for comparison purposes. Thermal stabilization is not favorable at this site because of high fuel and labor costs, as well as other factors. A conceptual design for a thermal stabilization operation is described. Sufficient information to assess the leaching alternative is available only for the Durango, Colorado site. Because of the large amount of vanadium and uranium in the pile, the income from the sale of these strategic minerals could pay for as much as 58% of the expense of removing, transporting, and covering the pile

  8. Ra-226 concentrations in the hydrographic basins near uranium mining and milling in Brazil

    A monitoring survey of the 226Ra concentrations in river waters in the vicinity of the mining area and future milling facilities in the Pocos de Caldas region began in January 1977. The objective of the monitoring survey is to establish a baseline to allow future comparisons between the 226Ra concentrations in waters of the hydrographic basins of the Pocos de Caldas plateau before and after the beginning of full scale commercial operations. Open pit mining started in July 1977 in the uranium deposits of Campo do Cercado, but the main uranium body has not been reached yet. Seasonal variations in riverflow are apparently accompanied by little variations in the 226Ra concentrations in river waters. A crude calculational dosimetric model is in the process of being developed to estimate annual dose equivalent to an individual from 226Ra via drinking water and irrigation patterns as a first step to calculate the collective dose equivalent commitment to the population of the Pocos de Caldas plateau and surroundings

  9. Radio-Ecological Conditions of Groundwater in the Area of Uranium Mining and Milling Facility - 13525

    Manmade chemical and radioactive contamination of groundwater is one of damaging effects of the uranium mining and milling facilities. Groundwater contamination is of special importance for the area of Priargun Production Mining and Chemical Association, JSC 'PPMCA', because groundwater is the only source of drinking water. The paper describes natural conditions of the site, provides information on changes of near-surface area since the beginning of the company, illustrates the main trends of contaminators migration and assesses manmade impact on the quality and mode of near-surface and ground waters. The paper also provides the results of chemical and radioactive measurements in groundwater at various distances from the sources of manmade contamination to the drinking water supply areas. We show that development of deposits, mine water discharge, leakages from tailing dams and cinder storage facility changed general hydro-chemical balance of the area, contributed to new (overlaid) aureoles and flows of scattering paragenetic uranium elements, which are much smaller in comparison with natural ones. However, increasing flow of groundwater stream at the mouth of Sukhoi Urulyungui due to technological water infiltration, mixing of natural water with filtration streams from industrial reservoirs and sites, containing elevated (relative to natural background) levels of sulfate-, hydro-carbonate and carbonate- ions, led to the development and moving of the uranium contamination aureole from the undeveloped field 'Polevoye' to the water inlet area. The aureole front crossed the southern border of water inlet of drinking purpose. The qualitative composition of groundwater, especially in the southern part of water inlet, steadily changes for the worse. The current Russian intervention levels of gross alpha activity and of some natural radionuclides including 222Rn are in excess in drinking water; regulations for fluorine and manganese concentrations are also in excess

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

    The US 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, building foundations, and materials associated with the former processing of uranium ore at UMTRA sites are placed into disposal cells. The cells are designed to reduce radon and other radiation emissions and to prevent further contamination of ground water. One UMTRA Project site is near Maybell, Colorado. Surface cleanup at this site is under way and is scheduled for completion in 1996. The tailings are being stabilized in-place at this site. The disposal area has been withdrawn from public use by the DOE and is referred to as the permanent withdrawal area. The Ground Water Project evaluates the nature and extent of ground water contamination resulting from past uranium ore processing activities. The Ground Water Project at this site is in its beginning stages. This report is a site-specific document that will be used to evaluate current and future potential 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 environment. Currently, no points of exposure (e.g. a drinking water well); and no receptors of contaminated ground water have been identified at the Maybell site. Therefore, there are no current human health and ecological risks associated with exposure to contaminated ground water. Furthermore, if current site conditions and land- and water-use patterns do not change, it is unlikely that contaminated ground water would reach people or the ecological communities in the future

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

    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

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

    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.

  13. Comments and responses on the Remedial Action Plan and site design for stabilization of the Inactive Uranium Mill Tailings Site, Grand Junction, Colorado. Revision 1

    This report contains information concerning public comments and responses on the remedial action plan and site design for stabilization of the inactive uranium mill tailings site in Grand Junction, Colorado

  14. Establishment of a radiation protection program: protection of environment and public from radiation emanating from uranium mining and milling waste

    The thesis has examined the uranium mining processes; the waste generated; intake pathways; estimated doses incurred and possible remediation practices. A Radiation Protection Programme is required for protecting the public and environment from possible consequences of radiation from the waste. Radioactive waste from uranium mining and milling has been identified as one of the major sources of radiation exposure to members of the public and the environment. Uranium mill tailings, waste rock and dusts are the types of which release most of the ionizing radiation. The sources of radiation exposure form of Radon-222 gas, gamma radiation as well as alpha particles in dusts. The doses from radioactive waste can be significant requiring attention from regulatory bodies as well as licensees. Radiation from the waste can be directly ingested and inhaled by members of the public. Consumption of contaminated water and food stuffs can also lead to ingestion of radionuclides from the waste. A uranium mine of 0.1% grade ore and residual uranium concentration of up to 10% in the waste rock can generate an annual dose of 2.45 mSv to a member of the public residing within a distance of up to 2km from the mine or tailings site. The annual dose rate decreases when the mine is shut down and when the tailings are covered to limit radon gas emission rate. (au)

  15. Final Environmental Statement related to the decommissioning of the Edgemont uranium mill. Docket No. 40-1341 Tennessee Valley Authority

    After an assessment of concerns and alternatives and the addition of conditions related to the proposed decommissioning project operations, the proposed action permits the decommissioning of the existing uranium milling facilities at Edgemont, South Dakota, including removal or cleanup of mill buildings, removal of tailings sands and slimes from the mill site, and removal of contaminated soil from the mill site and local environs. It is estimated by TVA that approximately 2.1 x 106 MT (2.3 x 106 tons) of tailings and an undetermined amount of contaminated soil will be removed from the mill site. It is also proposed that all radioactive materials, removed in the course of carrying out the proposed action, be transported by truck and/or slurry pipeline to an impoundment, located about 3.21 km southeast of the mill site, constructed especially to ensure containment of such material for the foreseeable future. The project area that will undergo major land disturbance consists of 207 ha (including 104 ha at the disposal site, 12 ha for the haul road to be constructed between the mill and disposal site, and the 86-ha mill site), plus the potential removal of at least 17 ha of ponderosa pine and surficial soil east of the mill site and an unestablished, but small, area of surficial soil in the Cottonwood community. The latter two areas have been contaminated by windblown tailings. All disturbed areas will be reclaimed and revegetated. The title to the tailings disposal site will be transferred to state or federal entities so that any future use can be controlled to ensure the health and safety of the public. Chapters are devoted to alternatives including the proposed action; the affected environment; and environmental consequences, monitoring to detect impacts, and mitigation of impacts. Qualifications of the task group are given and agencies receiving the draft environmental statement are listed

  16. An approach to the calculation of dose commitment arising from different methods for the long-term management of uranium mill tailings

    This report describes the development and use of a diagnostic model designed to improve our understanding of the release of radionuclides to the natural environment from uranium mill tailings management areas. The study first developed the characteristics of a hypothetical tailings management area such that a variety of management alternatives could be studied using simulation modelling techniques. Factors describing climate and the surrounding environment were fixed and the simulation model was run to predict releases from the tailings site over time periods of thousands of years. Simulation runs were carried out for a series of six major management alternatives ranging from old abandoned practices through currently accepted practices to as yet to be proven management techniques. This summary report describes the major aspects of the diagnostic model and the findings obtained through its use. The report does not attempt to predict doses or radionuclide dispersal patterns for any specific site, existing or planned. A more complete technical discussion of the model may be found in the two technical appendices associated with this report INFO--0097 (app.A.) and INFO--0097 (app.B)

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

    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

  18. Improving the adsorption ability of graphene sheets to uranium through chemical oxidation, electrolysis and ball-milling

    Three types of graphene sheets (GS) were decorated by chemical oxidation, electrolysis and ball-milling, respectively. These oxidized samples were characterized using SEM, XRD, Raman, FT-IR and XPS, and then were employed to enrich U(VI) from aqueous solutions as a function of pH, contact time and initial concentration of U(VI). These results displayed that the quantities and types of oxygen-functional groups were extremely different through these methods, which highly determined the adsorption capacity of graphene oxide to uranium. This work may provide some helpful information to optimize these fabrication processes and improve the adsorption ability of GS to uranium. (author)

  19. Environmental assessment of remedial action at the Slick Rock uranium mill tailings sites Slick Rock, Colorado. Draft

    NONE

    1993-06-01

    The Uranium Mill Tailings Radiation Control Act of 1978 (UMTRCA) authorized the US Department of Energy (DOE) to clean up two uranium mill tailings processing sites near Slick Rock, Colorado, in San Miguel County. The purpose of the cleanup is to reduce the potential health effects associated with the radioactive materials remaining on the sites and on vicinity properties (VP) associated with the sites. The US Environmental Protection Agency (EPA) promulgated standards for the UMTRCA that contained measures to control the contaminated materials and to protect the groundwater from further degradation. Remedial actions at the Slick Rock sites must be performed in accordance with these standards and with the concurrence of the US Nuclear Regulatory Commission (NRC).

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

    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.

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

    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

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

    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

  3. Research and development of measures to be taken for long term stabilization and isolation of uranium mill tailings

    This paper contains results of research on the environmental impact of uranium mill tailings used for backfilling mined-out voids from uranium ore mining at Zhovty Vody. The general objective of the research was a comparison of qualitative and quantitative characteristics of the performance of using mill tailings as backfilling instead of the customary sand. Specifically the backfill massif strengths, the radiation impact on the mine staff, possible groundwater contamination with radionuclides from the backfill massif, and air and soil contamination with dust and gas emissions from the mine and the backfill mixing plant were investigated. It was concluded that the use of tailings as a backfill material would be feasible, both from a technical as well as an environmental impact point of view. (author)

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

    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.

  5. Final environmental statement related to the Atlas Minerals Division, Atlas Corporation, Atlas Uranium Mill (Grand County, Utah)

    The proposed action is the continuation of Source Material License SUA-917 issued to Atlas Corporation for the operation of the Atlas Uranium Mill in Grand County, Utah, near Moab (Docket No. 40-3453). The present mill was designed for an 1100 MT (1200 ton) per day processing rate with 0.25% uranium ore feed. The actual ore processing rate may vary up to 1450 MT (1600 ton) per day if lower grade ores are processed, but the annual production rate of 836 MT (921 tons) U3O8 will not be exceeded. Possible environmental impacts and adverse effects are identified. Conditions for the protection of the environment are set forth before the license can be renewed

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

    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.

  7. Environmental assessment of remedial action at the Maybell Uranium Mill Tailings Site near Maybell, Colorado. Revision 1

    1994-04-01

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment (Attachment 1) and a floodplain/wetlands attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service (FWS).

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

    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

  9. Environmental assessment of remedial action at the Maybell uranium mill tailings site near Maybell, Colorado: Revision 2

    1994-11-01

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment and a floodplain/wetlands assessment are included as part of this EA. This report and attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service (FWS).

  10. Rock riprap design methods and their applicability to long-term protection of uranium mill tailings impoundments

    This report reviews the more accepted or recommended riprap design methods currently used to design rock riprap protection against soil erosion by flowing water. The basic theories used to develop the various methods are presented. The Riprap Design with Safety Factors Method is identified as the logical choice for uranium mill tailings impoundments. This method is compared to the other methods and its applicability to the protection requirements of tailings impoundments is discussed. Other design problems are identified and investigative studies recommended

  11. Removal of hazardous radionuclides from uranium ore and/or mill tailings. Progress report, October 1, 1978-September 30, 1979

    Scheitlin, F.M.; Bond, W.D.

    1980-01-01

    The leaching of uranium ore and mill tailings to remove radium was studied. A few scouting tests were performed to obtain data on the recovery of radium, thorium, and uranium from leach liquors and on the recycle of leaching agents. Nitric acid, hydrochloric acid, ethylenediaminetetraacetic acid (EDTA), and diethylenetriaminepentaacetic acid (DTPA) were evaluated as leachants using one sample of a western US ore and two samples of tailings obtained from different uranium mills that employ the sulfuric acid leach process. Leached solids with radium contents approaching 10 pCi/g (98% radium removal) were obtained after six stages of batch, crosscurrent leaching with 3 M HNO/sub 3/ at 33% concentration of solids and a temperature of 60/sup 0/C. On the basis of two-stage tests on mill tailings, 0.5 M EDTA solutions at pH values of 8.2 to 11.6 were found to be more effective, while hydrochloric acid in two- or three-stage tests was less effective than nitric acid. Solutions of 0.3 M EDTA and 0.05 M DTPA were ineffective. No important differences were observed in the leaching behavior of ore and of mill tailings derived from the same ore. The residue remaining after six stages of nitric acid leaching was relatively intractable to radium leaching with water or additional nitric acid leaching. Tests indicated that the recycle of nitric acid is chemically feasible by evaporating the leach liquors to recover unused acid and then thermally decomposing the metal salts to recover consumed acid. Radium recoveries of 99+% by carrying on barium sulfate were shown to be chemically feasible in a series of experiments with leach liquors, but processing applications would probably require methods for barium recycle and barium-radium separation. Recovery of /sup 230/Th and uranium from nitrate leach liquors by tri-n-butyl phosphate extraction appears promising in initial tests.

  12. Environmental assessment of remedial action at the Maybell uranium mill tailings site near Maybell, Colorado: Revision 2

    The purpose of this environmental assessment (EA) is to evaluate the environmental impacts resulting from remedial action at the Maybell uranium mill tailings site near Maybell, Colorado. A biological assessment and a floodplain/wetlands assessment are included as part of this EA. This report and attachments describe the proposed action, affected environment, and environmental impacts associated with the proposed remedial action, including impacts to threatened and endangered species listed or proposed for listing by the US Fish and Wildlife Service (FWS)

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

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

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

    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.

  15. Review of the non-radiological contaminants in the long-term management of uranium mine and mill wastes

    In the management of uranium mine and mill wastes public attention has focussed on hazards associated with radioactivity. However, in many such wastes non-radiological contaminants such as heavy metals, acids, organic complexes, and colloids also form potentially significant long-term health and environmental hazards. The purpose of the present review is to examine in general terms the geochemical basis for management strategies aimed at minimizing the long-term impact of radiological and non-radiological contaminants. (author)

  16. Conception and methodology of a prospective safety report for uranium mills tailings ponds

    Uranium mill tailings ponds (MTP) stand for the highest potential risk of all legacies from uranium milling. The overall objective of this work was to develop a standardised application document and a working tool for responsible authorities to conduct a continuous safety status description and assessment as well as a prognosis of the respective tailings pond site. - Safety Assessment Principles are based on guide and control values specified in or derived from laws, guidances, norms or standards for the main components who are: technical installations and geo-mechanics, radioactivity, chemical-toxic pollutants. - Data Base: Monitoring data (ground- and seepage water), Radon in near bottom air, Data and information from expertises, reports and technical documents, Site specific data and information (data base A.LAS.KA. / FbU). - Exposure Pathways Analysis. Determination of the radiation exposure to members of the public of different age caused by radioactivity discharges from the tailings pond by means of an authorized calculation procedure. 0.1 to 0.3 mSv/yr with a predominant contribution of ingestion of drinking water (about 80 %). Determination of the hazard resulting from chemical-toxic pollutants according to German regulations. Only relevance of Arsenic via seepage water path. - Forecast of Contaminant Propagation via Groundwater. A three dimensional site specific model was generated to forecast the contaminant distribution in the downstream groundwater flow by means of the available monitoring data. - Safety Assessment. The present status of the tailings pond 'Lengenfeld' was evaluated as to be safe for all three risk components and therefore it is no need for short term measures to minimize hazards or to reduce the contaminants spreading via groundwater. The geochemical environment of the tailings can be regarded as steady, but they are hydraulically tensed by overlaying spar cover. The low permeability of the tailings prevents a significant vertical

  17. Radium-226 in vegetation and substrates at inactive uranium mill sites

    Marple, M.L.

    1980-01-01

    Results of a study of the content of radium-226 in plants growing on inactive uranium mill tailings sites in the Four Corners Region of the southwestern United States and in plants grown under greenhouse conditions with minimal surficial contamination are reported. Field plant samples and associated substrates were analyzed from two carbonate tailings sites in the Grants Mineral Belt of New Mexico. Radium activities in air-cleaned samples ranged from 5 to 368 pCi/g (dry weight) depending on species and location: activities in plants growing on local soils averaged 1.0 pCi/g. The talings and local soils contain 140 to 1400 pCi/g and 2.1 pCi/g, respectively. An evaluation of cleaning methods on selected samples showed that from 17 to 79% of the radium activity measured in air-cleaned samples was due to surficial contamination, which varied with species and location. A survey of 18 inactive uranium mill sites in the Four Corners Region was performed. Radium activity in plant tissues from nine species ranged from 2 to 210 pCi/g on bare tailings and from 0.3 to 30 pCi/g on covered tailings The radium content in most of the soil overburdens on the covered tailings piles was 10 to 17 pCi/g. An experiment was performed to measure radium-226 uptake by two species grown on tailings covered with a shallow (5 cm) soil layer. A grass, Sporobolus airoides (alkali sacaton) and a shrub, Atriplex canescens (four-wing saltbush), were studied. The tailings were a mixture of sands and slimes from a carbonate pile. The tailings treatments were plants grown in a soil cover over tailings; the controls were plants grown only in soil. Three soil types, dune sand, clay loam, and loam, were used. The radium activity of the plant tissue from the tailings treatment compared to that of the appropriate control was 1 to 19 times greater for the grass and 4 to 27 times greater for the shrub.

  18. Radium-226 in vegetation and substrates at inactive uranium mill sites

    Results of a study of the content of radium-226 in plants growing on inactive uranium mill tailings sites in the Four Corners Region of the southwestern United States and in plants grown under greenhouse conditions with minimal surficial contamination are reported. Field plant samples and associated substrates were analyzed from two carbonate tailings sites in the Grants Mineral Belt of New Mexico. Radium activities in air-cleaned samples ranged from 5 to 368 pCi/g (dry weight) depending on species and location: activities in plants growing on local soils averaged 1.0 pCi/g. The talings and local soils contain 140 to 1400 pCi/g and 2.1 pCi/g, respectively. An evaluation of cleaning methods on selected samples showed that from 17 to 79% of the radium activity measured in air-cleaned samples was due to surficial contamination, which varied with species and location. A survey of 18 inactive uranium mill sites in the Four Corners Region was performed. Radium activity in plant tissues from nine species ranged from 2 to 210 pCi/g on bare tailings and from 0.3 to 30 pCi/g on covered tailings The radium content in most of the soil overburdens on the covered tailings piles was 10 to 17 pCi/g. An experiment was performed to measure radium-226 uptake by two species grown on tailings covered with a shallow (5 cm) soil layer. A grass, Sporobolus airoides (alkali sacaton) and a shrub, Atriplex canescens (four-wing saltbush), were studied. The tailings were a mixture of sands and slimes from a carbonate pile. The tailings treatments were plants grown in a soil cover over tailings; the controls were plants grown only in soil. Three soil types, dune sand, clay loam, and loam, were used. The radium activity of the plant tissue from the tailings treatment compared to that of the appropriate control was 1 to 19 times greater for the grass and 4 to 27 times greater for the shrub

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

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

  20. Biological characterization of radiation exposure and dose estimates for inhaled uranium milling effluents. Annual progress report, April 1981-March 1982

    The problems addressed are the protection of uranium will workers from occupational exposure to uranium through routine bioassay programs and the assessment of accidental worker exposures. Comparisons of chemical properties and the biological behavior of refined uranium ore (yellowcake) are made to identify important properties that influence uranium distribution patterns among organs. These studies will facilitate calculations of organ doses for specific exposures and associated health risk estimates and will identify important bioassay procedures to improve evaluations of human exposures. Sampling of airborne yellowcake at four uranium mills showed that aerosols were heterogeneous, changed with time and contained approx. 50% of the airborne uranium in particles greater than 12 μm aerodynamic diameter. Results are related to specific packaging steps and to predictions of appreciable upper respiratory tract deposition rates for the aerosols, if inhaled by a worker without respiratory protection. Previously used in vitro dissolution techniques were evaluated and the uses of the results for interpreting urinary bioassay data are described. Preliminary results from an inhalation experiment using rats indicate that the clearance patterns of inhaled uranium from lung agreed quantitatively with results from in vitro dissolution and infrared analyses of the yellowcake used. Preliminary results from an experiment to simulate contamination of a wound by yellowcake showed that more of the implanted dose of a less soluble form of yellowcake was retained at the wound site than of a more soluble form at 32 days after implantation. The results did not quantitatively agree with in vitro dissolution results. A two-year study of yellowcake from two mills was initiated. Twenty Beagle dogs were exposed by nose-only inhalation to a more soluble form of yellowcake and 20 to a less soluble form

  1. Characterization of molybdenum interfacial crud in a uranium mill that employs tertiary-amine solvent extraction

    In the present work, samples of a molybdenum-caused green gummy interfacial crud from an operating western US uranium mill have been physically and chemically examined. Formaton of cruds of this description has been a long-standing problem in the use of tertiary amine solvent extraction for the recovery of uranium from low-grade ores (Amex Process). The crud is essentially an organic-continuous dispersion containing about 10 wt % aqueous droplets and about 37 wt % greenish-yellow crystalline solids suspended in kerosene-amine process solvent. The greenish-yellow crystals were found to be a previously unknown double salt of tertiary amine molybdophosphate with three tertiary amine chlorides having the empirical formula (R3NH)3[PMo12O40].3(R3NH)Cl. To confirm the identification of the compound, a pure trioctylamine (TOA) analog was synthesized. In laboratory extraction experiments, it was demonstrated that organic-soluble amine molydophosphate forms slowly upon contact of TOA solvent with dilute sulfuric acid solutions containing low concentrations of molybdate and phosphate. If the organic solutions of amine molybdophosphate were then contacted with aqueous NaCl solutions, a greenish-yellow precipitate of (TOAH)3[PMo12O40].3(TOAH)Cl formed at the interface. The proposed mechanism for the formation of the crud under process conditions involves build up of molybdenum in the solvent, followed by reaction with extracted phosphate to give dissolved amine molybdophosphate. The amine molybdophosphate then co-crystallizes with amine chloride, formed during the stripping cycle, to give the insoluble double salt, which precipitates as a layer of small particles at the interface. The proposed solution to the problem is the use of branched-chain, instead of straight-chain, tertiary amine extractants under the expectation that branching would increase the solubility of the double salt. 2 figures, 5 tables

  2. 226Ra bioavailability to plants at the Urgeiriça uranium mill tailings site.

    Madruga, M J; Brogueira, A; Alberto, G; Cardoso, F

    2001-01-01

    Large amounts of solid wastes (tailings) resulting from the exploitation and treatment of uranium ore at the Urgeiriça mine (north of Portugal) have been accumulated in dams (tailing ponds). To reduce the dispersion of natural radionuclides into the environment, some dams were revegetated with eucalyptus (Eucalyptus globolus) and pines (Pinus pinea). Besides these plants, some shrubs (Cytisus spp.) are growing in some of the dams. The objective of this study is to determine the 226Ra bioavailability from uranium mill tailings by quantifying the total and available fraction of radium in the tailings and to estimate its transfer to plants growing on the tailing piles. Plant and tailing samples were randomly collected and the activity concentration of 226Ra in plants (aerial part and roots) and tailings was measured by gamma-spectrometry. The exchangeable fraction of radium in tailings was quantified using one single step extraction with 1 mol dm-3 ammonium acetate (pH = 7) or 1 mol dm-3 calcium chloride solutions. The results obtained for 226Ra uptake by plants show that 226Ra concentration ratios for eucalyptus and pines decrease at low 226Ra concentrations in the tailings and appear relatively constant at higher radium concentrations. For shrubs, the concentration ratios increase at higher 226Ra solid waste concentrations approaching a saturation value. Percentage values of 16.0 +/- 8.3 and 12.9 +/- 8.9, for the fraction of radium extracted from the tailings, using 1 mol dm-3 ammonium acetate or calcium chloride solutions, respectively, were obtained. The 226Ra concentration ratios determined on the basis of exchangeable radium are one order of magnitude higher than those based on total radium. It can be concluded that, at a 95% confidence level, more consistent 226Ra concentration ratios were obtained when calculated on the basis of available radium than when total radium was considered, for all the dams. PMID:11379070

  3. Partitioning of natural radionuclides in sediments around a former uranium mine and mill

    Partitioning of natural radionuclides in sediments from streams affected by the waste piles of the former uranium mine and mill located at Zirovski vrh, Slovenia, was performed by applying a sequential extraction procedure. The sediments were collected at three sites located upstream and three sites located downstream of the waste piles. Then the four-step Community Bureau of Reference (BCR) sequential extraction protocol was applied to the samples and the natural radionuclides 238U, 230Th, 226Ra, 210Pb and 210Po were analysed in each extraction fraction. It was expected that the fractionation of natural radionuclides originating from the waste piles would differ from that upstream of the influence of waste piles because their chemical environment had been altered during the processes of uranium extraction. This difference could allow tracing of the radionuclides coming from the waste piles downstream of the affected watercourses. The results definitely showed that the total activity concentrations at sites downstream of the influence of the waste piles were higher than at sites upstream of the piles. However, this difference was geographically very limited and could no longer be detected already at a distance of about 5 km downstream. Unexpectedly, the fractionation of radionuclides upstream and downstream of the area of influence of the waste piles did not appear to be significantly altered. The sole differences found were for 238U and 226Ra in the second fraction (the 'Fe/Mn oxides' fraction) and for 210Po in the fourth fraction (the 'residue' fraction) of the BCR sequential extraction protocol. (author)

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

    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.

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

    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

  6. Estimated average annual radon-222 concentrations around the former uranium mill site in Shiprock, New Mexico. Final technical note

    Uranium mills, as a part of the nuclear fuel cycle, produce large volumes of wastes which contain both the long and short-lived radionuclides from the naturally-occurring uranium decay chain. A relatively short-lived member of the chain, radon-222, is a noble gas and can diffuse from the wastes and be transported from its point of origin by prevailing winds. The airborne radon-222 decays into other short-lived radioactive progeny which may result in human inhalation exposures at considerable distances from the point of origin. Since the parent of radon-222 has a half-life of 1620 years, exposure to radon and its progeny will persist for thousands of years. This study was made to estimate the annual average radon-222 concentrations around the former Shiprock, New Mexico uranium mill site in order to identify areas which may require limited or restricted occupancy and to evaluate the effectiveness of the site decontamination activities in reducing the ambient airborne radon-222 concentrations. Using on- and off-site meteorological data and radon source term estimations, average annual radon-222 isoconcentration lines were determined by computer modeling for the mill site area. The lines were determined for both pre- and post-decontamination periods

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

    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.

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

    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.

  9. Environmental effects on 222Rn fluence rate from reclaimed uranium mill tailings

    The author measured 222Rn fluence rate from 2 plots with uranium mill tailings buried beneath 30 cm of overburden and 30 cm of topsoil. An additional 30 cm of clay covered the tailings on 1 of the plots and each plot was subdivided into bare soil and vegetated subplots. The author also measured a control plot, identical to the plot without a clay cap but having no tailings. In addition to fluence rate, The author measured moisture in each of the plot layers, atmospheric pressure, air temperature and relative humidity during each sampling period. The author used linear correlation, two-way ANOVA and stepwise multiple regression to analyze the effects of the plot characteristics and the environmental variables on 222Rn fluence rate. The mean fluence rate from the plot having both a clay cap and a vegetated surface was over 3 times that of the vegetated plot without a clay cap and 14 times that of the bare plot with a clay cap. The interaction effect may be due to the proliferation of roots in the moist clay and active transport of dissolved 222Rn to the surface in water

  10. Annual status report on the inactive uranium mill tailings sites remedial action program

    1979-12-01

    Assessments of inactive uranium mill tailings sites in the United States led to the designation of 25 processing sites for remedial action under the provisions of Section 102(a) Public Law 95-604. The Department of Energy assessed the potential health effects to the public from the residual radioactive materials on or near the 25 sites; and, with the advice of the Environmental Protection Agency, the Secretary established priorities for performing remedial action. In designating the 25 sites and establishing the priorities for performing remedial action, the Department of Energy consulted with the Environmental Protection Agency, Nuclear Regulatory Commission, Department of the Interior, governors of the affected States, Navajo Nation, and appropriate property owners. Public participation in this process was encouraged. During Fiscal Year 1980, Department of Energy will be conducting surveys to verify the radiological characterization at the designated processing sites; developing cooperative agreements with the affected States; and initiating the appropriate National Environmental Policy Act documentation prior to conducting specific remedial actions.

  11. Annual status report on the inactive uranium mill tailings sites remedial action program

    Assessments of inactive uranium mill tailings sites in the United States led to the designation of 25 processing sites for remedial action under the provisions of Section 102(a) Public Law 95-604. The Department of Energy assessed the potential health effects to the public from the residual radioactive materials on or near the 25 sites; and, with the advice of the Environmental Protection Agency, the Secretary established priorities for performing remedial action. In designating the 25 sites and establishing the priorities for performing remedial action, the Department of Energy consulted with the Environmental Protection Agency, Nuclear Regulatory Commission, Department of the Interior, governors of the affected States, Navajo Nation, and appropriate property owners. Public participation in this process was encouraged. During Fiscal Year 1980, Department of Energy will be conducting surveys to verify the radiological characterization at the designated processing sites; developing cooperative agreements with the affected States; and initiating the appropriate National Environmental Policy Act documentation prior to conducting specific remedial actions

  12. Engineering assessment of inactive uranium mill tailings, Naturita site, Naturita, Colorado. Phase II, Title I

    1977-11-01

    Ford, Bacon and Davis Utah Inc. has performed an engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Naturita, Colorado. The Phase II, Title I services include the preparation of topographic maps, the performance of core drillings sufficient to determine areas and volumes of tailings, the performance of radiometric measurements to determine the extent of radium contamination, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site hydrology and meteorology, and the costing of alternative corrective actions. Radon gas release from the 704,000 tons of tailings at the Naturita site constitutes the most significant environmental impact although windblown tailings and external gamma radiation are also factors. Ranchers Exploration and Development Company has been licensed by the State of Colorado to reprocess the tailings at a location 3 mi from the present site where they will be stabilized for long-term storage. The remedial action options include remedial action for structures in Naturita and Nucla (Option I) at an estimated cost of $270,000 and remedial action for structures and open land adjacent to the tailings site (Option II) at an estimated cost of $950,000.

  13. Liquid wastes from mining and milling of uranium ores - a laboratory study of treatment methods

    Methods of reducing the concentration of contaminants in mine water and in the acidic raffinate from uranium milling operations have been studied. Lime, limestone, caustic soda and lime-soda ash mixtures were compared as reagents for neutralising raffinates and for removing amines and heavy metals including radium from solution. All methods of neutralisation reduced contaminant levels significantly. Two-stage neutralisation using limestone in the first stage to pH 4, followed by second stage lime treatment appears to be an economically attractive approach. This method usually gave the lowest residual radium concentration provided the solids from the first stage were not removed before adding lime. Radium can be further removed from neutralised raffinates or from mine water conditioned with sulphate by the addition of barium chloride to co-precipitate the sulphates of barium and radium. The concentration of radium was readily reduced to less than 3 pCi l-1 by adding 10 mg Ba l-1 raffinate. For mine waters conditioned to 0.01 M in sulphate, barium additions of 20 mg l-1 were required to attain the same radium concentrations. Adsorption on barytes was also effective in removing radium from conditioned mine water and neutralised raffinates. (author)

  14. Analysis of BIOMOVS II Uranium Mill Tailings scenario 1.07 with the RESRAD computer code

    The residual radioactive material guidelines (RESRAD) computer code developed at Argonne National Laboratory was selected for participation in the model intercomparison test scenario, version 1.07, conducted by the Uranium Mill Tailings Working Group in the second phase of the international Biospheric Model Validation Study. The RESRAD code was enhanced to provide an output attributing radiological dose to the nuclide at the point of exposure, in addition to the existing output attributing radiological dose to the nuclide in the contaminated zone. A conceptual model to account for off-site accumulation following atmospheric deposition was developed and showed the importance of considering this process for this off-site scenario. The RESRAD predictions for the atmospheric release compared well with most of the other models. The peak and steady-state doses and concentrations predicted by RESRAD for the groundwater release also agreed well with most of the other models participating in the study; however, the RESRAD plots shows a later breakthrough time and sharp changes compared with the plots of the predictions of other models. These differences were due to differences in the formulation for the retardation factor and to not considering the effects of longitudinal dispersion

  15. Engineering assessment of inactive uranium mill tailings, Naturita site, Naturita, Colorado. Phase II, Title I

    Ford, Bacon and Davis Utah Inc. has performed an engineering assessment of the problems resulting from the existence of radioactive uranium mill tailings at Naturita, Colorado. The Phase II, Title I services include the preparation of topographic maps, the performance of core drillings sufficient to determine areas and volumes of tailings, the performance of radiometric measurements to determine the extent of radium contamination, the evaluation of resulting radiation exposures of individuals and nearby populations, the investigation of site hydrology and meteorology, and the costing of alternative corrective actions. Radon gas release from the 704,000 tons of tailings at the Naturita site constitutes the most significant environmental impact although windblown tailings and external gamma radiation are also factors. Ranchers Exploration and Development Company has been licensed by the State of Colorado to reprocess the tailings at a location 3 mi from the present site where they will be stabilized for long-term storage. The remedial action options include remedial action for structures in Naturita and Nucla (Option I) at an estimated cost of $270,000 and remedial action for structures and open land adjacent to the tailings site (Option II) at an estimated cost of $950,000

  16. Physical stability of asphalt emulsion admix seal radon barrier for uranium mill tailings

    Pacific Northwest Laboratory, is investigating the use of an asphalt emulsion admix seal to reduce the release of radon from uranium mill tailings. A key requirement of any cover system is its long-term stability; the cover must withstand failure over very long periods of time. An important determinant of overall cover system stability is the integrity of the 6.35-cm (2.5-in.) thick asphalt admix seal. Therefore, the physical stability of this seal was examined. The investigation considered the mechanical interaction between the tailings pile and cover. The potential effect of differential settlement of the tailings pile on the integrity of the seal system was also examined. Results indicate that the minimum span length the seal could withstand without failing is 0.34 m (1.1 ft). This assumes a differential settlement of 4.92 cm (1.94 in.) at the center resulting from the application of a 0.76-m (2.5-ft) cover. At spans greater than 0.60 m (1.97 ft), no tensile strain would develop

  17. Radiological survey of the inactive uranium-mill tailings at Lakeview, Oregon

    The results of the radiological survey of the inactive uranium-mill site at Lakeview, Oregon, show that the average gamma-ray exposure rate 1 m above the tailings pile and the evaporation pond area (now dry) is close to the average background level for the area (11 μR/hr). The 226Ra concentration in most of the surface soil and sediment samples is also at or below the average background value for surface soil samples in the area (0.8 pCi/g). Calculated 226Ra concentrations, based on gamma radiation measurements in shallow (1-m-deep) holes, are in agreement with the results of surface soil and sediment analyses and with gamma-ray exposure rate measurements. The tailings at this site have been stabilized by the addition of 46 to 60 cm (18 to 24 in.) of soil that supports vigorous growth of vegetation. This treatment, coupled with a low-level inventory of 226Ra in the tailings (50 Ci), has resulted in limited spread of tailings by wind and water

  18. Mathematical simulation of contaminant distribution in and around the uranium mill tailing piles, Riverton, Wyoming

    As part of the Research and Development phase of the Uranium Mill Tailings Remedial Action (UMTRA) program, the Lawrence Berkeley Laboratory (LBL) has set itself the goal of explaining the physico-chemical evolution of the Riverton site on the basis of the already collected field data at the site (Tokunaga and Narasimhan, 1982, Smith and Moed, 1982; White et al., 1984). The predictive aspects as well as addressing the question of critical quantity of field data have to be considered during the design phase of the project as a joint effort between the LBL team and the construction engineers. At the present time, LBL is in the process of completing the Research and Development phase of the work. As of this writing, the development of an appropriate set of mathematical models has been completed. The computations of the soil-water regime at the upper tailings surface, involving climatological factors is nearing completion. Computations of chemical transport are still in progress. This paper is devoted to a description of the key mathematical issues, the mathematical models that are needed to address these issues and a discussion of the model results pertaining to the soil water regime at the tailings-atmosphere interface. 11 references, 3 figures

  19. Radiological survey activities: uranium mill tailings remedial action project procedures manual

    The US Department of Energy (DOE) was assigned the responsibility for conducting remedial action at 24 sites, which are located in one eastern and nine western states. The DOE's responsibilities are being met through its Uranium Mill Tailings Remedial Action Project Office (UMTRA-PO) in Albuquerque, New Mexico. The purpose of this Procedures Manual is to provide a standardized set of procedures that document in an auditable manner the activities performed by the Radiological Survey Activities (RASA) group in the Dosimetry and Biophysical Transport Section (DABTS) of the Health and Safety Research Division (HASRD) at the Oak Ridge National Laboratory (ORNL), in its role as the Inclusion Survey Contractor (ISC). Members of the RASA group assigned to the UMTRA Project are headquartered in the ORNL/RASA office in Grand Junction, Colorado, and report to the ORNL/RASA Project Manager. The Procedures Manual ensures that the organizational, administrative, and technical activities of the RASA/UMTRA group conform properly to those of the ISC as described in the Vicinity Properties Management and Implementation Manual and the Summary Protocol. This manual also ensures that the techniques and procedures used by the RASA/UMTRA group and contractor personnel meet the requirements of applicable governmental, scientific, and industrial standards

  20. Simulation of water flow and retention in earthen-cover materials overlying uranium mill tailings

    The water retention characteristics of a multilayer earthen cover for uranium mill tailings were simulated under arid weather conditions common to Grand Junction, Colorado. The multilayer system described in this report consists of a layer of wet clay/gravel (radon barrier), which is separated from a surface covering of fill soil by a washed rock material used as a capillary barrier. The capillary barrier is designed to prevent the upward migration of water and salt from the tailings to the soil surface and subsequent loss of water from the wet clay. The flow model, UNSATV, described in this report uses hydraulic properties of the layered materials and historical climatic data for two years (1976 and 1979) to simulate long-term hydrologic response of the multilayer system. Application of this model to simulate the processes of infiltration, evaporation and drainage is described in detail. Simulations over a trial period of one relatively wet and two dry years indicated that the clay-gravel layer remained near saturation, and hence, that the layer was an effective radon barrier. Estimates show that the clay-gravel layer would not dry out (i.e., revert to drying dominated by isothermal vapor-flow conditions) for at least 20 years, provided that the modeled dry-climate period continues