WorldWideScience

Sample records for waste repository environments

  1. Geologic environments for nuclear waste repositories

    Directory of Open Access Journals (Sweden)

    Paleologos Evan K.

    2017-01-01

    Full Text Available High-level radioactive waste (HLW results from spent reactor fuel and reprocessed nuclear material. Since 1957 the scientific consensus is that deep geologic disposal constitutes the safest means for isolating HLW for long timescales. Nuclear power is becoming significant for the Arab Gulf countries as a way to diversify energy sources and drive economic developments. Hence, it is of interest to the UAE to examine the geologic environments currently considered internationally to guide site selection. Sweden and Finland are proceeding with deep underground repositories mined in bedrock at depths of 500m, and 400m, respectively. Equally, Canada’s proposals are deep burial in the plutonic rock masses of the Canadian Shield. Denmark and Switzerland are considering disposal of their relative small quantities of HLW into crystalline basement rocks through boreholes at depths of 5,000m. In USA, the potential repository at Yucca Mountain, Nevada lies at a depth of 300m in unsaturated layers of welded volcanic tuffs. Disposal of low and intermediate-level radioactive wastes, as well as the German HLW repository favour structurally-sound layered salt stata and domes. Our article provides a comprehensive review of the current concepts regarding HLW disposal together with some preliminary analysis of potentially appropriate geologic environments in the UAE.

  2. Expected environment for waste packages in a salt repository

    International Nuclear Information System (INIS)

    Pederson, L.R.; Clark, D.E.; Hodges, F.N.; McVay, G.L.; Rai, D.

    1983-01-01

    This paper discusses results of recent efforts to define the very near-field (within approximately 2 m) environmental conditions to which waste packages will be exposed in a salt repository. These conditions must be considered in the experimental design for waste package materials testing, which includes corrosion of barrier materials and leaching of waste forms. Site-specific brine compositions have been determined, and standard brine compositions have been selected for testing purposes. Actual brine compositions will vary depending on origin, temperature, irradiation history, and contact with irradiated rock salt. Results of irradiating rock salt, synthetic brines, rock salt/brine mixtures, and reactions of irradiated rock salt with brine solutions are reported. 38 references, 3 figures, 2 tables

  3. Parametric study of the effects of thermal environment on a waste package for a tuff repository

    Energy Technology Data Exchange (ETDEWEB)

    Johnstone, J K; Sundberg, W D; Krumhansl, J L [Sandia National Laboratories Albuquerque, NM, (USA)

    1982-12-31

    The thermal environment has been modeled in a simple reference waste package in a tuff repository for a variety of variables. The waste package was composed of the waste form, canister, overpack and backfill. The emplacement hole was 122cm dia. Waste forms used in the calculations were commercial high level waste (CHLW) and spent fuel (SF). Canister loadings varied from 50 to 100 kW/acre. Primary attention was focused on the backfill behavior in the thermal and chemical environment. Results are related to the maximum temperature calculated for the backfill. These calculations raise serious concerns about the effectiveness of the backfill within the context of the total waste package.

  4. The application of nuclear geophysics method to evaluate the geological environment of nuclear waste repository

    International Nuclear Information System (INIS)

    Fang, Fang; Xiaoqin, Wang; Kuanliang, Li; Xinsheng, Hou; Jingliang, Zhu; Binxin, Hu

    2002-01-01

    'Cleanly land should be given back ground.' This is a task while nuclear engineering have to be retired. We applied the nuclear geophysics methods and combined with geology, hydrology, geochemistry, and other methods, to evaluate the environment of nuclear waste repository. It is the important work to renovate environment and prepare technology before ex-service of the nuclear engineering

  5. Definition of the waste package environment for a repository located in salt

    International Nuclear Information System (INIS)

    Clark, D.E.; Bradley, D.J.

    1983-01-01

    The expected environmental conditions for emplaced waste packages in a salt repository are simulated in the materials testing program to evaluate performance. Synthetic brines, based on the analyses of actual brines (both intrusion and inclusion), are used for corrosion and leach testing. Elevated temperatures (to 150 0 C) and radiation fields of up to 10 3 rad/h are employed as conservative conditions to bracket expected performance and provide data for worst case scenarios. Obtaining a precise definition of the waste package environment in a salt repository and its change with time is closely tied to detailed site characterization of the candidate salt repository horizon. It is expected that field testing can augment some of the materials testing currently under way and can provide increased confidence in the predicted site-specific near-field conditions. 17 references, 5 figures, 1 table

  6. The physical and chemical environment and radionuclide migration in a low level radioactive waste repository

    International Nuclear Information System (INIS)

    Torok, J.; Buckley, L.P.

    1988-01-01

    The expected physical and chemical environment within the low-level radioactive waste repository to be sited at Chalk River is being studied to establish the rate of radionuclide migration. Chemical conditions in the repository are being assessed for their effect on buffer performance and the degradiation of the concrete structure. Experimental programs include the effect of changes in solution chemistry on radionuclide distribution between buffer/backfill materials and the aqueous phase; the chemical stability of the buffer materials and the determination of the controlling mechanism for radionuclide transport during infiltration

  7. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the second part of a report of a preliminary study for AECL. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) geotechnical assessment, 2) hydrogeology and waste containment, 3) thermal loading and 4) rock mechanics. (author)

  8. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the first part of a report of a preliminary study for Atomic Energy of Canada Limited. It considers the requirements for an underground waste repository for the disposal of wastes produced by the Canadian Nuclear Fuel Program. The following topics are discussed with reference to the repository: 1) underground layout, 2) cost estimates, 3) waste handling, 4) retrievability, decommissioning, sealing and monitoring, and 5) research and design engineering requirements. (author)

  9. On release of radionuclides from a near-surface radioactive waste repository to the environment

    Directory of Open Access Journals (Sweden)

    Gudelis Arūnas

    2015-09-01

    Full Text Available A closed near-surface radioactive waste repository is the source of various radionuclides causing the human exposure. Recent investigations confirm an effectiveness of the engineering barriers installed in 2006 to prevent the penetration of radionuclides to the environment. The tritium activity concentration in groundwater decreased from tens of kBq/l to below hundreds of Bq/l. The monitoring and groundwater level data suggest the leaching of tritium from previously contaminated layers of unsaturated zone by rising groundwater while 210Pb may disperse as a decay product of 226Ra daughters.

  10. Nuclear waste repository siting

    International Nuclear Information System (INIS)

    Soloman, B.D.; Cameron, D.M.

    1987-01-01

    This paper discusses the geopolitics of nuclear waste disposal in the USA. Constitutional choice and social equity perspectives are used to argue for a more open and just repository siting program. The authors assert that every potential repository site inevitably contains geologic, environmental or other imperfections and that the political process is the correct one for determining sites selected

  11. Low level waste repositories

    International Nuclear Information System (INIS)

    Hill, P.R.H.; Wilson, M.A.

    1983-11-01

    Factors in selecting a site for low-level radioactive waste disposal are discussed. South Australia has used a former tailings dam in a remote, arid location as a llw repository. There are also low-level waste disposal procedures at the Olympic Dam copper/uranium project

  12. Radioactive waste repository study

    International Nuclear Information System (INIS)

    1978-11-01

    This is the third part of a report of a preliminary study for AECL. It summarizes the topics considered in reports AECL-6188-1 and AECL-6188-2 as requirements for an undergpound repository for disposal of wastes produced by the Canadian Nuclear Fuel Program. (author)

  13. Retention and radionuclide migration mechanisms in the environment of a radioactive waste repository in granitic formation

    International Nuclear Information System (INIS)

    Rancon, D.; Miara, P; Vinson, J.M.; Petronin, J.C.; Dozol, J.F.

    1986-01-01

    A laboratory pre-determination of retention mechanisms of radionuclides migrating outside the primary waste containers in repository surroundings was started up. Backfillings materials (clay and sand) as well as granite and its weathering products are concerned here. A method allowing the evaluation of the sorption and desorption of radionuclides of the surfaces of fractures by measuring surface retention coefficients, had initially been started up as well as a laboratory device developed for experiments in a reducing environment. The experiments have consisted of studying the sorbing properties of granite minerals of Auriat and its weathering products and of determining the retention of Np, Pu, AM, CS and Sr on the surface fractures of this granite. The influence of a reducing environment on the behaviour of activities has been studied. Complementary percolation tests have also been carried out on clays, at raised temperature and under irradiation. These experiments have enabled a deeper knowledge of retention mechanisms, the taking of parametric sensitivity measurements and the preparation of elaborating more performing experimental devices which included the parameters needed for a realistic simulation of transfer phenomena

  14. Role of groundwater oxidation potential and radiolysis on waste glass performance in crystalline repository environments

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.

    1985-01-01

    Laboratory experiments have shown that groundwater conditions in a Stripa granite repository will be as reducing as those in a basalt repository. The final oxidation potential (Eh) at 70 0 C for Stripa groundwater deaerated and equilibrated with crystalline granite was -0.45V. In contrast, the oxidation potential at 60 0 C for Grande Ronde groundwater equilibrated with basalt was -0.40V. The reducing groundwater conditions were found to slightly decrease the time-dependent release of soluble components from the waste glass. Spectrophotometric analysis of the equilibrated groundwaters indicated the presence of Fe 2+ confirming that the Fe 2+ /Fe 3+ couple is controlling the oxidation potential. It was also shown that in the alkaline pH regime of these groundwaters the iron species are primarily associated with x-ray amorphous precipitates in the groundwater. Gamma radiolysis in the absence of waste glass and in the absence of oxygen further reduces the oxidation potential of both granitic and basaltic groundwaters. The effect is more pronounced in the basaltic groundwater. The mechanism for this decrease is under investigation but appears related to the reactive amorphous precipitate. The results of these tests suggest that H 2 may not escape from the repository system as postulated and that radiolysis may not cause the groundwaters to become oxidizing in a crystalline repository when abundant Fe 2+ species are present. 23 refs., 3 figs., 3 tabs

  15. Rock support for nuclear waste repositories

    International Nuclear Information System (INIS)

    Abramson, L.W.; Schmidt, B.

    1984-01-01

    The design of rock support for underground nuclear waste repositories requires consideration of special construction and operation requirements, and of the adverse environmental conditions in which some of the support is placed. While repository layouts resemble mines, design, construction and operation are subject to quality assurance and public scrutiny similar to what is experienced for nuclear power plants. Exploration, design, construction and operation go through phases of review and licensing by government agencies as repositories evolve. This paper discusses (1) the various stages of repository development; (2) the environment that supports must be designed for; (3) the environmental effects on support materials; and (4) alternative types of repository rock support

  16. Role of groundwater oxidation potential and radiolysis on waste glass performance in crystalline repository environments

    International Nuclear Information System (INIS)

    Jantzen, C.M.; Bibler, N.E.

    1986-01-01

    Laboratory experiments have shown that groundwater conditions in a granite repository will be as reducing as those in a basalt repository. Chemical analysis of the reduced groundwaters confirmed that the Fe 2+ /Fe 3+ couple controls the oxidation potential (Eh). The reducing groundwater conditions were found to decrease the time-dependent release of soluble elements (Li and B) from the waste glass. However, due to the lower solubility of multivalent elements released from the glass when the groundwaters are reducing, these elements have significantly lower concentrations in the leachates. Gamma radiolysis reduced the oxidation potential of both granitic and basaltic groundwater in the absence of both waste glass and oxygen. This occurred in tests at atmospheric pressure where H 2 could have escaped from the solution. The mechanism for this decrease in Eh is under investigation but appears related to the reactive amorphous precipitate in both groundwaters. The results of these tests suggest that radiolysis may not cause the groundwaters to become oxidizing in a crystalline repository when abundant Fe 2+ species are present

  17. Stress corrosion cracking tests on high-level-waste container materials in simulated tuff repository environments

    International Nuclear Information System (INIS)

    Abraham, T.; Jain, H.; Soo, P.

    1986-06-01

    Types 304L, 316L, and 321 austenitic stainless steel and Incoloy 825 are being considered as candidate container materials for emplacing high-level waste in a tuff repository. The stress corrosion cracking susceptibility of these materials under simulated tuff repository conditions was evaluated by using the notched C-ring method. The tests were conducted in boiling synthetic groundwater as well as in the steam/air phase above the boiling solutions. All specimens were in contact with crushed Topopah Spring tuff. The investigation showed that microcracks are frequently observed after testing as a result of stress corrosion cracking or intergranular attack. Results showing changes in water chemistry during test are also presented

  18. Modeling the dissolution behavior of defense waste glass in a salt repository environment

    International Nuclear Information System (INIS)

    McGrain, B.P.

    1988-02-01

    A mechanistic model describing a dynamic mass balance between the production and consumption of dissolved silica was found to describe the dissolution behavior of SRL-165 defense waste glass in a high-magnesium brine (PBB3) at a temperature of 90 0 C. The synergistic effect of the waste package container on the glass dissolution rate was found to depend on a precipitation reaction for a ferrous silicate mineral. The model predicted that the ferrous silicate precipitate should be variable in composition where the iron/silica stoichiometry depended on the metal/glass surface area ratio used in the experiment. This prediction was confirmed experimentally by the variable iron/silica ratios observed in filtered leachates. However, the interaction between dissolved silica and iron corrosion products needs to be much better understood before the model can be used with confidence in predicting radionuclide release rates for a salt repository. 25 refs., 4 figs., 1 tab

  19. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    Energy Technology Data Exchange (ETDEWEB)

    F. Hua; K. Mon; P. Pasupathi; G. Gordon

    2004-05-11

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review.

  20. A Review Corrosion of TI Grade 7 and Other TI Alloys in Nuclear Waste Repository Environments

    International Nuclear Information System (INIS)

    Hua, F.; Mon, K.; Pasupathi, P.; Gordon, G.

    2004-01-01

    Titanium alloy degradation modes are reviewed in relation to their performance in repository environments. General corrosion, localized corrosion, stress corrosion cracking, hydrogen induced cracking, microbially influenced corrosion, and radiation-assisted corrosion of Ti alloys are considered. With respect to the Ti Grade 7 drip shields selected for emplacement in the repository at Yucca Mountain, general corrosion, hydrogen induced cracking, and radiation-assisted corrosion will not lead to failure within the 10,000 year regulatory period; stress corrosion cracking (in the absence of disruptive events) is of no consequence to barrier performance; and localized corrosion and microbially influenced corrosion are not expected to occur. To facilitate the discussion, Ti Grades 2, 5, 7, 9, 11, 12, 16, 17, 18, and 24 are included in this review

  1. AN EVALUATION OF HYDROGEN INDUCED CRACKING SUSCEPTIBILITY OF TITANIUM ALLOYS IN US HIGH-LEVEL NUCLEAR WASTE REPOSITORY ENVIRONMENTS

    Energy Technology Data Exchange (ETDEWEB)

    G. De; K. Mon; G. Gordon; D. Shoesmith; F. Hua

    2006-02-21

    This paper evaluates hydrogen-induced cracking (HIC) susceptibility of titanium alloys in environments anticipated in the Yucca Mountain nuclear waste repository with particular emphasis on the. effect of the oxide passive film on the hydrogen absorption process of titanium alloys being evaluated. The titanium alloys considered in this review include Ti 2, 5 , 7, 9, 11, 12, 16, 17, 18, 24 and 29. In general, the concentration of hydrogen in a titanium alloy can increase due to absorption of atomic hydrogen produced from passive general corrosion of that alloy or galvanic coupling of it to a less noble metal. It is concluded that under the exposure conditions anticipated in the Yucca Mountain repository, the HIC of titanium drip shield will not occur because there will not be sufficient hydrogen in the metal even after 10,000 years of emplacement. Due to the conservatisms adopted in the current evaluation, this assessment is considered very conservative.

  2. AN EVALUATION OF HYDROGEN INDUCED CRACKING SUSCEPTIBILITY OF TITANIUM ALLOYS IN US HIGH-LEVEL NUCLEAR WASTE REPOSITORY ENVIRONMENTS

    International Nuclear Information System (INIS)

    G. De; K. Mon; G. Gordon; D. Shoesmith; F. Hua

    2006-01-01

    This paper evaluates hydrogen-induced cracking (HIC) susceptibility of titanium alloys in environments anticipated in the Yucca Mountain nuclear waste repository with particular emphasis on the. effect of the oxide passive film on the hydrogen absorption process of titanium alloys being evaluated. The titanium alloys considered in this review include Ti 2, 5 , 7, 9, 11, 12, 16, 17, 18, 24 and 29. In general, the concentration of hydrogen in a titanium alloy can increase due to absorption of atomic hydrogen produced from passive general corrosion of that alloy or galvanic coupling of it to a less noble metal. It is concluded that under the exposure conditions anticipated in the Yucca Mountain repository, the HIC of titanium drip shield will not occur because there will not be sufficient hydrogen in the metal even after 10,000 years of emplacement. Due to the conservatisms adopted in the current evaluation, this assessment is considered very conservative

  3. Long-term observations programme on the geological environment of a radioactive waste repository in clayey or related formations, implications on the various phases of the project

    International Nuclear Information System (INIS)

    Manfroy, P.; Raynal, M.; Bonne, A.

    1993-01-01

    The process of emplacing radioactive waste in deep clayey or related formations involves numerous interdependent actions, the common objective of which is to guarantee optimum isolation of the waste for the durations required. Among these actions, observations on the geological environment will have to extend over a very long period of time, from site characterization to repository closure. All the far-field and near-field observations will constitute the basis and confirmation of the models intended to describe the phenomena which take place in the repository and its surrounding host formation and will have to be taken into account in the repository closure procedures. 6 refs

  4. Crevice Corrosion Behavior of Candidate Nuclear Waste Container Materials in Repository Environment Paper Number 02529

    International Nuclear Information System (INIS)

    Hua, F.; Sarver, J.; Mohn, W.

    2001-01-01

    Alloy 22 (UNS N06022) and Ti Grade 7 (UNS R52400) have been proposed as the corrosion resistant materials for fabricating the waste package outer barrier and the drip shield, respectively for the proposed nuclear waste repository Yucca Mountain Project. In this work, the susceptibility of welded and annealed Alloy 22 (N06022) and Ti Grade 7 (UNS R52400) to crevice corrosion was studied by the Multiple Crevice Assembly (ASTM G78) method combined with surface morphological observation after four and eight weeks of exposure to the Basic Saturated Water (BSW-12) in a temperature range from 60 to 105 C. The susceptibility of the materials to crevice corrosion was evaluated based on the appearance of crevice attack underneath the crevice formers and the weight loss data. The results showed that, after exposed to BSW-12 for four and eight weeks, no obvious crevice attack was observed on these materials. The descaled weight loss increased with the increase in temperature for all materials. The weight loss, however, is believed to be caused by general corrosion, rather than crevice corrosion. There was no significant difference between the annealed and welded materials either. On the other hand, to conclude that these materials are immune to crevice corrosion in BSW-12 will require longer term testing

  5. Conceptualization and software development of a simulation environment for probalistic safety assessment of radioactive waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Ghofrani, Javad

    2016-05-26

    Uncertainty and sensitivity analysis of complex simulation models are prominent issues, both in scientific research and education. ReSUS (Repository Simulation, Uncertainty propagation and Sensitivity analysis) is an integrated platform to perform such analysis with numerical models that simulate the THMC (Thermal Hydraulical Mechanical and Chemical) coupled processes via different programs, in particular in the context of safety assessments for radioactive waste repositories. This thesis presents the idea behind the software platform ReSUS and its working mechanisms. Apart from the idea and the working mechanisms, the thesis describes applications related to the safety assessment of radioactive waste disposal systems. In this thesis, previous simulation tools (including the preceding version of ReSUS) are analyzed in order to provide a comprehensive view of the state of the art. In comparison to this state, a more sophisticated software tool is developed here, which provides features which are not offered by previous simulation tools. To achieve this objective, the software platform ReSUS provides a framework for handling probabilistic data uncertainties using deterministic external simulation tools, thus enhancing uncertainty and sensitivity analysis. This platform performs probabilistic simulations of various models, in particular THMC coupled processes, using stand-alone deterministic simulation software tools. The complete software development process of the ReSUS Platform is discussed in this thesis. ReSUS components are developed as libraries, which are capable of being linked to other code implementations. In addition, ASCII template files are used as means for uncertainty propagation into the input files of deterministic simulation tools. The embedded input sampler and analysis tools allow for sensitivity analysis in several kinds of simulation designs. The novelty of the ReSUS platform consists in the flexibility to assign external stand-alone software

  6. Conceptualization and software development of a simulation environment for probalistic safety assessment of radioactive waste repositories

    International Nuclear Information System (INIS)

    Ghofrani, Javad

    2016-01-01

    Uncertainty and sensitivity analysis of complex simulation models are prominent issues, both in scientific research and education. ReSUS (Repository Simulation, Uncertainty propagation and Sensitivity analysis) is an integrated platform to perform such analysis with numerical models that simulate the THMC (Thermal Hydraulical Mechanical and Chemical) coupled processes via different programs, in particular in the context of safety assessments for radioactive waste repositories. This thesis presents the idea behind the software platform ReSUS and its working mechanisms. Apart from the idea and the working mechanisms, the thesis describes applications related to the safety assessment of radioactive waste disposal systems. In this thesis, previous simulation tools (including the preceding version of ReSUS) are analyzed in order to provide a comprehensive view of the state of the art. In comparison to this state, a more sophisticated software tool is developed here, which provides features which are not offered by previous simulation tools. To achieve this objective, the software platform ReSUS provides a framework for handling probabilistic data uncertainties using deterministic external simulation tools, thus enhancing uncertainty and sensitivity analysis. This platform performs probabilistic simulations of various models, in particular THMC coupled processes, using stand-alone deterministic simulation software tools. The complete software development process of the ReSUS Platform is discussed in this thesis. ReSUS components are developed as libraries, which are capable of being linked to other code implementations. In addition, ASCII template files are used as means for uncertainty propagation into the input files of deterministic simulation tools. The embedded input sampler and analysis tools allow for sensitivity analysis in several kinds of simulation designs. The novelty of the ReSUS platform consists in the flexibility to assign external stand-alone software

  7. Granite-repository - geochemical environment

    International Nuclear Information System (INIS)

    1979-04-01

    Some geochemical data of importance for a radioactive waste repository in hard rock are reviewed. The ground water composition at depth is assessed. The ground water chemistry in the vicinity of uranium ores is discussed. The redox system in Swedish bedrock is described. Influences of extreme climatic changes and of repository mining and construction are also evaluated

  8. Ventilation System Strategy for a Prospective Korean Radioactive Waste Repository

    International Nuclear Information System (INIS)

    Kim, Jin; Kwon, Sang Ki

    2005-01-01

    In the stage of conceptual design for the construction and operation of the geologic repository for radioactive wastes, it is important to consider a repository ventilation system which serves the repository working environment, hygiene and safety of the public at large, and will allow safe maintenance like moisture content elimination in repository for the duration of the repositories life, construction/operation/closure, also allowing safe waste transportation and emplacement. This paper describes the possible ventilation system design criteria and requirements for the prospective Korean radioactive waste repositories with emphasis on the underground rock cavity disposal method in the both cases of low and medium-level and high-level wastes. It was found that the most important concept is separate ventilation systems for the construction (development) and waste emplacement (storage) activities. In addition, ventilation network system modeling, natural ventilation, ventilation monitoring systems and real time ventilation simulation, and fire simulation and emergency system in the repository are briefly discussed.

  9. Radioactive Waste Repositories Administration - SURAO

    International Nuclear Information System (INIS)

    Kucerka, M.

    1998-01-01

    The Atomic Act specifies, among other things, responsibilities of the government in the field of safe disposal of radioactive wastes. To satisfy this responsibility, the Ministry of Industry and Trade has established the Radioactive Waste Repositories Administration (SURAO). SURAO's major responsibilities include: (a) the preparation, construction, commissioning, operation, and decommissioning of radioactive waste repositories and the monitoring of their environmental impacts; (b) radioactive waste management; (c) spent or irradiated nuclear fuel processing into a form suitable for storage/disposal or reuse; (d) record-keeping of received radioactive wastes and their producers; (e) administration of fund transfers as stipulated by the Atomic Act, Article 27; (f) development of proposals for specification of fees to be paid to the Nuclear Account; (g) responsibility for and coordination of research and development in the field of radioactive waste handling and management; (h) supervision of licensees' margin earmarked for the decommissioning of their facilities; (i) providing services in radioactive waste handling and management; (j) handling and management of radioactive wastes that have been transferred to the Czech Republic from abroad and cannot be sent back; (k) interim administration of radioactive wastes that have become state property. The Statute of the Administration is reproduced in full. (P.A.)

  10. Spent fuel performance in geologic repository environments

    International Nuclear Information System (INIS)

    Bradley, D.J.

    1985-10-01

    The performance assessment of the waste package is a current area of study in the United States program to develop a geologic repository for nuclear waste isolation. The waste package is presently envisioned as the waste form and its surrounding containers and possibly a packing material composed of crushed host rock or mixtures of that rock with clays. This waste package is tied to performance criteria set forth in recent legislation. It is the goal of the Civilian Radioactive Waste Management Program to obtain the necessary information on the waste package, in several geologic environments, to show that the waste package provides reasonable assurance of meeting established performance criteria. This paper discusses the United States program directed toward managing high-level radioactive waste, with emphasis on the current effort to define the behavior of irradiated spent fuel in repository groundwaters. Current studies are directed toward understanding the rate and nature (such as valence state, colloid form if any, solid phase controlling solubility) of radionuclide release from the spent fuel. Due to the strong interactive effect of radiation, thermal fields, and waste package components on this release, current spent fuel studies are being conducted primarily in the presence of waste package components over a wide range of potential environments

  11. Effects of radiation on the chemical environment surrounding waste canisters in proposed repository sites and possible effects on the corrosion process

    International Nuclear Information System (INIS)

    Glass, R.S.

    1981-12-01

    This report explores the interaction of ionizing radiation with various environments. In particular, worst case (aqueous) environments for the proposed nuclear waste repository sites are considered. Emphasis is on the fundamental chemical and physical processes involved. The identities of possible radiolysis products (both transient and stable) have been sought through a literature search. The effect of radiation on corrosion processes is discussed. The radiation-induced chemical environment in the worst case repository sites is not well defined. Attention should therefore be given to fundamental studies exploring the interaction of such environments with components of the nuclear waste package, including the canister materials and backfills. Identification and quantification of radiolysis products would be helpful in this regard

  12. Investigation on design of repository for radioactive waste

    International Nuclear Information System (INIS)

    Zhang Boming; Zhang Ruixue; Wang Fengying

    2010-01-01

    The scheme design of the repository for radioactive waste is introduced according to the traits of radioactive waste in Jiangsu province, such as the style of the repository, lifting facilities, the step for preventing or controlling flood, the aseismatic measure, the pollution prevention and so on. This ensured the radioactive waste and the waste radioactive sources to be stored in security, the area environment not to be polluted. It can improve the use of nuclear technology in Jiangsu province. (authors)

  13. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    Notz, K.J.

    1989-01-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will be disposed of in a geologic repository. The two major sources of these materials are commercial light-water reactor (LWR) spent fuel and immobilized high-level waste (HLW). Other wastes that may require long-term isolation include non-LWR spent fuels and miscellaneous sources such as activated metals. Detailed characterizations are required for all of these potential repository wastes. These characterizations include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. This information has been extracted from primary data sources, evaluated, and assembled in a Characteristics Data Base which provides data in four formats: hard copy standard reports, menu-driven personal computer (PC) data bases, program-level PC data bases, and mainframe computer files. The Characteristics Data Base provides a standard set of self-consistent data to the various areas of responsibility including systems integration and waste stream analysis, storage, transportation, and geologic disposal. The data will be used for design studies, evaluation of alternatives, and system optimization by OCRWM and supporting contractors. 7 refs., 5 figs., 7 tabs

  14. Radioactive waste repository of high ecological safety

    International Nuclear Information System (INIS)

    Sobolev, I.; Barinov, A.; Prozorov, L.

    2000-01-01

    With the purpose to construct a radioactive waste repository of high ecological safety and reliable containment, MosNPO 'Radon' specialists have developed an advanced type repository - large diameter well (LBD) one. A project is started for the development of a technology for LDW repository construction and pilot operation of the new repository for 25-30 years. The 2 LDW repositories constructed at the 'Radon' site and the developed monitoring system are described

  15. Corrosion phase formation on container alloys in basalt repository environments

    International Nuclear Information System (INIS)

    Johnston, R.G.; Anantatmula, R.P.; Lutton, J.M.; Rivera, C.L.

    1986-01-01

    The Basalt Waste Isolation Project is evaluating the suitability of basalt in southeastern Washington State as a possible location for a nuclear waste repository. The performance of the waste package, which includes the waste form, container, and surrounding packing material, will be affected by the stability of container alloys in the repository environment. Primary corrosion phases and altered packing material containing metals leached from the container may also influence subsequent reactions between the waste form and repository environment. Copper- and iron-based alloys were tested at 50 0 to 300 0 C in an air/steam environment and in pressure vessels in ground-water-saturated basalt-bentonite packing material. Reaction phases formed on the alloys were identified and corrosion rates were measured. Changes in adhering packing material were also evaluated. The observed reactions and their possible effects on container alloy durability in the repository are discussed

  16. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    Cowart, C.G.; Notz, K.J.

    1992-10-01

    This report presents the results of a fully documented peer review of DOE/RW-0184, Rev. 1, ''Characteristics of Potential Repository Wastes''. The peer review was chaired and administered by oak Ridge National Laboratory (ORNL) for the Department of Energy (DOE), Office of Civilian Radioactive Waste Management (OCRWM) and was conducted in accordance with OCRWM QA procedure QAAP 3.3 ''Peer Review'' for the purpose of quailing the document for use in OCRWM quality-affecting work. The peer reviewers selected represent a wide range of experience and knowledge particularly suitable for evaluating the subject matter. A total of 596 formal comments were documented by the seven peer review panels, and all were successfully resolved. The peers reached the conclusion that DOE/RW-0184, Rev. 1, is quality determined and suitable for use in quality-affecting work

  17. Underground repository for radioactive wastes

    International Nuclear Information System (INIS)

    Cassibba, R.O.

    1989-01-01

    In the feasibility study for an underground repository in Argentina, the conceptual basis for the final disposal of high activity nuclear waste was set, as well as the biosphere isolation, according to the multiple barrier concept or to the engineering barrier system. As design limit, the container shall act as an engineering barrier, granting the isolation of the radionuclides for approximately 1000 years. The container for reprocessed and vitrified wastes shall have three metallic layers: a stainless steel inner layer, an external one of a metal to be selected and a thick intermediate lead layer preselected due to its good radiological protection and corrosion resistance. Therefore, the study of the lead corrosion behaviour in simulated media of an underground repository becomes necessary. Relevant parameters of the repository system such as temperature, pressure, water flux, variation in salt concentrations and oxidants supply shall be considered. At the same time, a study is necessary on the galvanic effect of lead coupled with different candidate metals for external layer of the container in the same experimental conditions. Also temporal evaluation about the engineering barrier system efficiency is presented in this thesis. It was considered the extrapolated results of corrosion rates and literature data about the other engineering barriers. Taking into account that corrosion is of a generalized type, the integrity of the lead shall be maintained for more than 1000 years and according to temporal evaluation, the multiple barrier concept shall retard the radionuclide dispersion to the biosphere for a period of time between 10 4 and 10 6 years. (Author) [es

  18. Nuclear waste repository simulation experiments

    International Nuclear Information System (INIS)

    Rothfuchs, T.; Wieczorek, K.; Feddersen, H.K.; Staupendahl, G.; Coyle, A.J.; Kalia, H.; Eckert, J.

    1986-12-01

    This document is the third joint annual report on the Cooperative German-American 'Brine Migration Tests' that are in progress at the Asse salt mine in the Federal Republic of Germany (FRG). This Government supported mine serves as an underground test facility for research and development (R and D)-work in the field of nuclear waste repository research and simulation experiments. The tests are designed to simulate a nuclear waste repository to measure the effects of heat and gamma radiation on brine migration, salt decrepitation, disassociation of brine, and gases collected. The thermal mechanical behavior of salt, such as room closure, stresses and changes of the properties of salt are measured and compared with predicted behavior. This document covers the following sections: Issues and test objectives: This section presents issues that are investigated by the Brine Migration Test, and the test objectives derived from these issues; test site: This section describes the test site location and geology in the Asse mine; test description: A description of the test configuration, procedures, equipment, and instrumentation is given in this section; actual test chronology: The actual history of the test, in terms of the dates at which major activities occured, is presented in this section. Test results: This section presents the test results observed to data and the planned future work that is needed to complete the test; conclusions and recommendations: This section summarizes the conclusions derived to date regarding the Brine Migration Test. Additional work that would be useful to resolve the issues is discussed. (orig.)

  19. Nuclear waste repository design and construction

    International Nuclear Information System (INIS)

    Bohlke, B.M.; Monsees, J.E.

    1987-01-01

    Extensive underground excavation will be required for construction of a mined geologic repository for nuclear waste. Hundreds of thousands of feet of drift will be required based on the conceptual layout design for each candidate nuclear waste repository. Comparison of boring and blasting excavation methods are discussed, as are special design and construction requirements (e.g., quality assurance procedures and performance assessment) for the nuclear waste repository. Comparisons are made between boring and blasting construction methods for the repository designs proposed for salt, volcanic tuff, and basalt

  20. Summary of United States Geological Survey investigations of fluid-rock-waste reactions in evaporite environments under repository conditions

    International Nuclear Information System (INIS)

    Stewart, D.B.; Jones, B.F.; Roedder, E.; Potter, R.W. II

    1980-01-01

    The interstitial and inclusion fluids contained in rock salt and anhydrite, though present in amounts less than 1 weight per cent, are chemically aggressive and may react with canisters or wastes. The three basic types of fluids are: (1) bitterns residual from saline mineral precipitation including later recrystallization reactions; (2) brines containing residual solutes from the formation of evaporite that have been extensively modified by reactions with contiguous carbonate of clastic rocks; and (3) re-solution brines resulting from secondary dehydration of evaporite minerals or solution of saline minerals by undersaturated infiltrating waters. Fluid composition can indicate that meteoric flow systems have contacted evaporites or that fluids from evaporites have migrated into other formations. The movement of fluids trapped in fluid inclusions in salt from southeast New Mexico is most sensitive to ambient temperature and to inclusion size, although several other factors such as thermal gradient and vapour/liquid ratio are also important. There is no evidence of a threshold temperature for movement of inclusions. Empirical data are given for determining the amount of brine reaching the heat source if the temperature, approximate amount of total dissolved solids, and Ca:Mg ratio in the brine are known. SrCl 2 and CsCl can reach high concentrations in saturated NaCl solutions and greatly depress the liquidus. The possibility that such fluids, if generated, could migrate from a high-level waste repository must be minimized because the fluid would contain its own radiogenic energy source in the first decades after repository closure, thus changing the thermal evolution of the repository from designed values. (author)

  1. A global nuclear waste repository

    Science.gov (United States)

    Lin, Wunan

    As a concerned scientist, I think that having a global nuclear waste repository is a reachable goal for human beings. Maybe through this common goal, mankind can begin to treat each other as brothers and sisters. So far, most human activities are framed by national boundaries, which are purely arbitrary. Breaking through these national boundaries will be very beneficial to human beings.Formation of the International Geosphere-Biosphere Program in 1986 indicates a growing awareness on the part of scientists regarding Earth as a system. The Apollo missions gave us a chance to look back at Earth from space. That perspective emphasized that our Earth is just one system: our only home. It is in deed a lonely boat in the high sea of dark space. We must take good care of our “boat.”

  2. Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

    International Nuclear Information System (INIS)

    R.B. Rebak

    2006-01-01

    Several countries are considering geological repositories to dispose of nuclear waste. The environment of most of the currently considered repositories will be reducing in nature, except for the repository in the US, which is going to be oxidizing. For the reducing repositories, alloys such as carbon steel, stainless steels and titanium are being evaluated. For the repository in the US, some of the most corrosion resistant commercially available alloys are being investigated. This paper presents a summary of the behavior of the different materials under consideration for the repositories and the current understanding of the degradation modes of the proposed alloys in ground water environments from the point of view of general corrosion, localized corrosion and environmentally assisted cracking

  3. Chemical risks from nuclear waste repositories

    International Nuclear Information System (INIS)

    Persson, L.

    1988-01-01

    Studies concerning the chemical risks of nuclear waste are reviewed. The radiological toxicity of the material is of primary concern but the potential nonradiological toxicity should not be overlooked as the chemotoxic substances may reach the biosphere from a nuclear waste repository. In the report is concluded that the possible chemotoxic effects of a repository for nuclear waste should be studied as a part of the formal risk assessment of the disposal concept. (author)

  4. Waste inventory, waste characteristics and waste repositories in Japan

    International Nuclear Information System (INIS)

    Shimooka, K.

    1997-01-01

    There are two types of repositories for the low level radioactive wastes in Japan. One is a trench type repository only for concrete debris generated from the dismantling of the research reactor. According to the safety assurance system, Japan Atomic Energy Research Institute (JAERI) has disposed of the concrete debris arose from the dismantling of the Japan Power Demonstration Reactor (JPDR). The other type is the concreted pit with engineered barriers. Rokkasho Low Level Radioactive Waste Disposal Center has this type of repository mainly for the power plant wastes. Japan Nuclear Fuel Ltd. (JNFL) established by electric power companies is the operator of the LLW disposal project. JNFL began the storage operation in 1992 and buried approximately 60,000 drums there. Two hundred thousand drums of uniformly solidified, waste may be buried ultimately. 4 refs, 3 tabs

  5. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    1992-07-01

    The LWR spent fuels discussed in Volume 1 of this report comprise about 99% of all domestic non-reprocessed spent fuel. In this report we discuss other types of spent fuels which, although small in relative quantity, consist of a number of diverse types, sizes, and compositions. Many of these fuels are candidates for repository disposal. Some non-LWR spent fuels are currently reprocessed or are scheduled for reprocessing in DOE facilities at the Savannah River Site, Hanford Site, and the Idaho National Engineering Laboratory. It appears likely that the reprocessing of fuels that have been reprocessed in the past will continue and that the resulting high-level wastes will become part of defense HLW. However, it is not entirely clear in some cases whether a given fuel will be reprocessed, especially in cases where pretreatment may be needed before reprocessing, or where the enrichment is not high enough to make reprocessing attractive. Some fuels may be canistered, while others may require special means of disposal. The major categories covered in this chapter include HTGR spent fuel from the Fort St. Vrain and Peach Bottom-1 reactors, research and test reactor fuels, and miscellaneous fuels, and wastes generated from the decommissioning of facilities

  6. Post-closure resaturation of a deep radioactive waste repository

    International Nuclear Information System (INIS)

    Cox, I.C.S.; Rodwell, W.R.

    1989-03-01

    The post-closure resaturation of a deep radioactive waste repository has been modelled for a number of generic disposal concepts. A combination of numerical ground water flow simulations and analytical calculations has been used to investigate the variation of repository fluid pressure and degree of water saturation with time, and to determine the factors influencing resaturation times. The host rock permeability was found to be the most important determining factor. For geological environments regarded as likely for a waste repository, resaturation is predicted to be a short term process compared with gas generation and contaminant migration timescales. (author)

  7. Management of radioactive waste at Novi Han Repository

    International Nuclear Information System (INIS)

    Stefanova, I.G.; Mateeva, M.D.; Milanov, M.V.

    2002-01-01

    The Novi Han Repository is the only existing repository in Bulgaria for the disposal of radioactive waste from nuclear applications in industry, medicine and research. The repository was constructed in the early sixties according to the existing requirements. It was operated by the Institute for Nuclear Research and Nuclear Energy for more than thirty years without any accident or release of radioactivity to the environment, but without any investment for upgrading. As a consequence, the Bulgarian Nuclear Safety Authority temporarily stopped the operation of the repository in 1994. The measures for upgrading the Novi Han Repository, supported by the IAEA under TC Project BUL/4/005 'Increasing Safety of Novi Han Repository', are presented in this paper. They comprise: assessment of radionuclide inventory and future waste arisings, characterisation of disposal vaults, characterisation of the site, safety assessment, upgrading of the monitoring system, option study for the selection of treatment and conditioning processes and the development of a conceptual design for low and intermediate level waste processing and storage facility, immediate measures for improvement of the existing disposal vaults and infrastructure, construction of above-ground temporary storage structures, and resuming the operation of the Novi Han Repository. The necessary activities for re-licensing of the Novi Han Repository, construction of a waste processing and storage facility and a disposal facility for spent sealed sources are discussed. (author)

  8. Hydrothermal conditions around a radioactive waste repository

    International Nuclear Information System (INIS)

    Thunvik, R.; Braester, C.

    1981-12-01

    Numerical solutions for the hydrothermal conditions around a hard rock repository for nuclear fuel waste are presented. The objective of the present investigation is to illustrate in principle the effect of heat released from a hypothetical radioactive waste repository with regard to anisotropy in the rock permeability. Permeability and porosity are assumed to be constant or to decrease exponentially with depth. The hypothetical repository is situated below a horizontal ground surface or below the crest of a hill, and it is assumed that the water table follows the topography. Major interest in the analysis is directed towards the influence of anisotropy in the permeability on the flow patterns and travel times for water particles, being traced from the repository to the ground surface. The presented results show that anisotropy in the permeability may have a significant influence on the flow conditions around the repository and subsequently also on the travel times from the repository. (Authors)

  9. Waste package for a repository located in salt

    International Nuclear Information System (INIS)

    Basham, S.J. Jr.

    1983-01-01

    This paper describes the current status of the waste package designs for salt repositories. The status of the supporting studies of environment definition, corrosion of containment materials, and leaching of waste forms is also presented. Emphasis is on the results obtained in FY 83 and the planned effort in FY 84. 8 references, 3 figures, 1 table

  10. The interaction of Plutonium with Bacteria in the Repository Environment

    International Nuclear Information System (INIS)

    Gillow, J. B.; Francis, A. J.; Lucero, D. A.; Papenguth, H. W.

    2000-01-01

    Microorganisms in the nuclear waste repository environment may interact with plutonium through (1) sorption, (2) intracellular accumulation, and (3) transformation speciation. These interactions may retard or enhance the mobility of Pu by precipitation reactions, biocolloid formation, or production of more soluble species. Current and planned radioactive waste repository environments, such as deep subsurface halite and granite formations, are considered extreme relative to life processes in the near-surface terrestrial environment. There is a paucity of information on the biotransformation of radionuclides by microorganisms present in such extreme environments. In order to gain a better understanding of the interaction of plutonium with microorganisms present in the waste repository sites we investigated a pure culture (Halomonas sp.) and a mixed culture of bacteria (Haloarcula sinaiiensis, Marinobacter hydrocarbonoclasticus, Altermonas sp., and a γ-proteobacterium) isolated from the Waste Isolation Pilot Plant (WIPP) site and an Acetobacterium sp. from alkaline groundwater at the Grimsel Test Site in Switzerland

  11. Complex geologic characterization of the repository environment

    Energy Technology Data Exchange (ETDEWEB)

    Harper, T R [British Petroleum Research Center, Sunberry, England; Szymanski, J S

    1982-01-01

    The present basis for characterizing geological environments is identified in this paper, and the additional requirements imposed by the need to isolate high-level waste safely are discussed. Solutions to these additional requirements are proposed. The time scale of concern and the apparent complexity of the required multidisciplinary approach are identified. It is proposed that an increased use of the geologic record, together with a recognition that all geologic processes operate within an interdependent system, be a key feature in geologic characterization of deep repositories.

  12. Nuclear waste repository in basalt: preconceptual design guidelines

    International Nuclear Information System (INIS)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation

  13. Nuclear waste repository in basalt: preconceptual design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

    The development of the basalt waste isolation program parallels the growing need for permanent, environmentally safe, and secure means to store nuclear wastes. The repository will be located within the Columbia Plateau basalt formations where these ends can be met and radiological waste can be stored. These wastes will be stored such that the wastes may be retrieved from storage for a period after placement. After the retrieval period, the storage locations will be prepared for terminal storage. The terminal storage requirements will include decommissioning provisions. The facility boundaries will encompass no more than several square miles of land which will be above a subsurface area where the geologic makeup is primarily deep basaltic rock. The repository will receive, from an encapsulation site(s), nuclear waste in the form of canisters (not more than 18.5 feet x 16 inches in diameter) and containers (55-gallon drums). Canisters will contain spent fuel (after an interim 5-year storage period), solidified high-level wastes (HLW), or intermediate-level wastes (ILW). The containers (drums) will package the low-level transuranic wastes (LL-TRU). The storage capacity of the repository will be expanded in a time-phased program which will require that subsurface development (repository expansion) be conducted concurrently with waste storage operations. The repository will be designed to store the nuclear waste generated within the predictable future and to allow for reasonable expansion. The development and assurance of safe waste isolation is of paramount importance. All activities will be dedicated to the protection of public health and the environment. The repository will be licensed by the US Nuclear Regulatory Commission (NRC). Extensive efforts will be made to assure selection of a suitable site which will provide adequate isolation.

  14. Planning the rad waste repository - Croatian case

    International Nuclear Information System (INIS)

    Kucar Dragicevic, S.; Subasic, D.; Lokner, V.

    1996-01-01

    Radioactive waste is generated in Croatia from various nuclear applications as well as from the Krsko NPP (Slovenian and Croatian joint venture facility). The national programme on radioactive waste management is aimed at straightening existing infrastructure, establishing new (more transparent) system of responsibilities and development of new legislation. The siting of LL/ILW repository is important segments of the whole radioactive waste management cycle. The status and efficiency of the rad waste management infrastructure in the country have the significant influence on all the activities related to the project of repository construction - from the very first phases of preliminary planning and background preparations to advanced phases of the project development. The present status of the Croatian national radioactive waste infrastructure and its influence on the repository project are presented. The role of national legislation and institutional framework are specially discussed. (author)

  15. Calculated compositions of porewater affected by a nuclear waste repository in a tuff geologic environment from 0 to 10,000 years

    International Nuclear Information System (INIS)

    Criscenti, L.C.; Arthur, R.C.

    1994-01-01

    Porewater compositions were estimated for an environment assuming that high-level radioactive waste has been stored for 10,000 years under geologic conditions analogous to those at the Yucca Mountain site in Nevada. The porewater compositions calculated with the EQ3/EQ6 geochemical code are intended for use in preliminary performance assessments of borosilicate glass waste packages. The porewater compositions were calculated using water-rock interaction models that are loosely coupled with two time-temperature periods in the host rocks: a cooling period between 900 years and 3,000 years after repository closure and an isothermal period from 3,000 years to 10,000 years. Significant changes in water composition are predicted to occur during the initial period of water-rock interaction; for example, the pH of the porewater increases from 6.4 to 9.1. Constant porewater compositions are predicted during the isothermal period. The results suggest that major changes in porewater composition will occur over a relatively short time frame and that these changes will persevere throughout the repository lifetime. (author) 5 figs., 3 tabs., 28 refs

  16. Engineered barrier development for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    The BWIP Engineered Barrier Program has been developed to provide an integrated approach to the development of site-specific Engineered Barrier assemblages for a repository located in basalt. The goal of this program is to specify engineered and natural barriers which will ensure that nuclear and non-radioactive hazardous materials emplaced in a repository in basalt do not exceed acceptable rates of release to the biosphere. A wide range of analytical and experimental activities related to the basalt repository environment, waste package environment, waste/barrier/rock interactions, and barrier performance assessment provide the basis for selection of systems capable of meeting licensing requirements. Work has concentrated on specifying and testing natural and man-made materials which can be used to plug boreholes in basalt and which can be used as multiple barriers to surround nuclear waste forms and containers. The Engineered Barriers Program is divided into two major activities: multiple barrier studies and borehole plugging. 8 figures, 4 tables

  17. Monitoring of geological repositories for high level radioactive waste

    International Nuclear Information System (INIS)

    2001-04-01

    Geological repositories for disposal of high level radioactive waste are designed to provide isolation of the waste from human environment for many thousands of years. This report discusses the possible purposes for monitoring geological repositories at the different stages of a repository programme, the use that may be made of the information obtained and the techniques that might be applied. This report focuses on the different objectives that monitoring might have at various stages of a programme, from the initiation of work on a candidate site, to the period after repository closure. Each objective may require somewhat different types of information, or may use the same information in different ways. Having evaluated monitoring requirements, the report concludes with a brief evaluation of available monitoring techniques

  18. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1993-02-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This Paper describes a mathematical model design to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (author)

  19. Modelling gas generation in radioactive waste repositories

    International Nuclear Information System (INIS)

    Agg, P.J.

    1992-07-01

    In a repository containing low- and intermediate-level waste, gas generation will occur principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. This paper describes a mathematical model designed to address gas generation by these mechanisms. The metal corrosion model incorporates a three-stage process encompassing both aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. Gas concentrations have been measured over a period of three years in large-scale drum experiments designed to simulate repository conditions. Model predictions are confirmed against the experimental measurements, and a prediction is then made of gas concentrations and generation rates over an assessment period of one million years in a radioactive waste repository. (Author)

  20. International perspective on repositories for low level waste

    International Nuclear Information System (INIS)

    Bergstroem, Ulla; Pers, Karin; Almen, Ylva

    2011-12-01

    Nuclear energy production gives rise to different types of radioactive waste. The use of nuclear isotopes within the research, industry and medical sectors also generates radioactive waste. To protect man and the environment from radiation the waste is isolated and contained by deposition in repositories. These repositories may have various designs regarding location, barriers etc depending on the potential danger of the waste. In Sweden, low- and intermediate level waste (LILW) is disposed of in the SFR repository in Forsmark. The repository is located 60 metres down into the bedrock under the bottom of the sea and covered by 6 metres of water. It is planned to extend SFR to accommodate decommissioning waste from the dismantling of the Swedish nuclear power facilities and also for the additional operation waste caused by the planned prolonged operation time. When planning the extension consultations will be carried out with the host municipality, authorities, organisations and general public. In planning the extension, SKB has performed a worldwide compilation of how other countries have, or plan to, handle the final disposal of similar wastes. The aim of this report is to give a brief description of LILW repositories worldwide; including general brief descriptions of many facilities, descriptions of the waste and the barriers as well as safety assessments for a few chosen repositories which represent different designs. The latter is performed, where possible, to compare certain features against the Swedish SFR. To provide a background and context to this study, international organisations and conventions are also presented along with internationally accepted principles regarding the management of radioactive waste. Similar to SFR, suitable locations for the repositories have, in many countries, been found at sites that already have, or used to have nuclear activities, such as reactor sites. Abandoned and disused mines, such as the salt mines in Germany, also

  1. International perspective on repositories for low level waste

    Energy Technology Data Exchange (ETDEWEB)

    Bergstroem, Ulla; Pers, Karin; Almen, Ylva (SKB International AB (Sweden))

    2011-12-15

    Nuclear energy production gives rise to different types of radioactive waste. The use of nuclear isotopes within the research, industry and medical sectors also generates radioactive waste. To protect man and the environment from radiation the waste is isolated and contained by deposition in repositories. These repositories may have various designs regarding location, barriers etc depending on the potential danger of the waste. In Sweden, low- and intermediate level waste (LILW) is disposed of in the SFR repository in Forsmark. The repository is located 60 metres down into the bedrock under the bottom of the sea and covered by 6 metres of water. It is planned to extend SFR to accommodate decommissioning waste from the dismantling of the Swedish nuclear power facilities and also for the additional operation waste caused by the planned prolonged operation time. When planning the extension consultations will be carried out with the host municipality, authorities, organisations and general public. In planning the extension, SKB has performed a worldwide compilation of how other countries have, or plan to, handle the final disposal of similar wastes. The aim of this report is to give a brief description of LILW repositories worldwide; including general brief descriptions of many facilities, descriptions of the waste and the barriers as well as safety assessments for a few chosen repositories which represent different designs. The latter is performed, where possible, to compare certain features against the Swedish SFR. To provide a background and context to this study, international organisations and conventions are also presented along with internationally accepted principles regarding the management of radioactive waste. Similar to SFR, suitable locations for the repositories have, in many countries, been found at sites that already have, or used to have nuclear activities, such as reactor sites. Abandoned and disused mines, such as the salt mines in Germany, also

  2. The hydrogeologic environment for a proposed deep geologic repository in Canada for low and intermediate level radioactive waste - 59285

    International Nuclear Information System (INIS)

    Sykes, Jonathan F.; Normani, Stefano D.; Yin, Yong; Jensen, Mark R.

    2012-01-01

    A Deep Geologic Repository (DGR) for low and intermediate level radioactive waste has been proposed by Ontario Power Generation for the Bruce nuclear site in Ontario, Canada. As proposed the DGR would be constructed at a depth of about 680 m below ground surface within the argillaceous Ordovician limestone of the Cobourg Formation. This paper describes the hydrogeology of the DGR site developed through both site characterization studies and regional-scale numerical modelling analysis. The analysis provides a framework for the assembly and integration of the site-specific geo-scientific data and examines the factors that influence the predicted long-term performance of the geosphere barrier. Flow system evolution was accomplished using both the density-dependent FRAC3DVS-OPG flow and transport model and the two-phase gas and water flow computational model TOUGH2-MP. In the geologic framework of the Province of Ontario, the DGR is located on the eastern flank of the Michigan Basin. Borehole logs covering Southern Ontario combined with site-specific data from 6 deep boreholes have been used to define the structural contours and hydrogeologic properties at the regional-scale of the modelled 31 sedimentary strata that may be partially present above the Precambrian crystalline basement rock. The regional-scale domain encompasses an approximately 18500 km 2 region extending from Lake Huron to Georgian Bay. The groundwater zone below the Devonian includes units containing stagnant water having high concentrations of total dissolved solids that can exceed 300 g/L. The Ordovician sediments are significantly under-pressured. The horizontal hydraulic conductivity for the Cobourg limestone is estimated to be 2x10 -14 m/s based on straddle-packer hydraulic tests. The low advective velocities in the Cobourg and other Ordovician units result in solute transport that is diffusion dominant with Peclet numbers less than 0:003 for a characteristic length of unity. Long

  3. Citizen participation in nuclear waste repository siting

    International Nuclear Information System (INIS)

    Howell, R.E.; Olsen, D.

    1982-12-01

    The following study presents a proposed strategy for citizen participation during the planning stages of nuclear waste repository siting. It discusses the issue from the general perspective of citizen participation in controversial issues and in community development. Second, rural institutions and attitudes toward energy development as the context for developing a citizen participation program are examined. Third, major citizen participation techniques and the advantages and disadvantages of each approach for resolving public policy issues are evaluated. Fourth, principles of successful citizen participation are presented. Finally, a proposal for stimulating and sustaining effective responsible citizen participation in nuclear waste repository siting and management is developed

  4. GIS for the needs of the Radioactive Waste Repository Authority

    Directory of Open Access Journals (Sweden)

    Jitka Mikšová

    2007-06-01

    Full Text Available The Radioactive Waste Repository Authority (RAWRA is a state organisation responsible for the management of activities related to the disposal of all existing and future radioactive waste and spent nuclear fuel classed as a waste in Czech Republic. Worldwide, a deep geological repository is considered the highest degree of safety for a nuclear waste disposal. Such a repository has to be built in a stable geological environment ensuring the isolation of the stored radioactive waste from the surrounding environment for a long period of time. The selection of suitable site for the deep geological repository construction is a complicated and long term process. Considering this fact and also in respect to an assumed volume of varied datasets the GIS RAWRA was established to ensure convenient management and availability of data containing spatial information.The system is based on ESRI (ArcInfo including extensions, ArcSDE, ArcIMS, Leica Geosystems (Image Analysis and Microsoft software (MS SQL Server. Resulting datasets from six recommended potentially suitable sites for the location of a geological repository have been incorporated into the geodatabase to date. The necessary analysis was made using ESRI software tools and, in addition, custom applications were developed including the metadata editor, etc. This analysis was carried out with respect to existing geological and non-geological criteria defined for a nuclear waste repository. Finally, all six investigated sites with a total area of 240 km2 were reduced in area, each of them resulting in an area of approximately 10km2 for further detailed characterisation.

  5. Salt Repository Project Waste Package Program Plan: Draft

    International Nuclear Information System (INIS)

    Carr, J.A.; Cunnane, J.C.

    1986-01-01

    Under the direction of the Office of Civilian Radioactive Waste Management (OCRWM) created within the DOE by direction of the Nuclear Waste Policy Act of 1982 (NWPA), the mission of the Salt Repository Project (SRP) is to provide for the development of a candidate salt repository for disposal of high-level radioactive waste (HLW) and spent reactor fuel in a manner that fully protects the health and safety of the public and the quality of the environment. In consideration of the program needs and requirements discussed above, the SRP has decided to develop and issue this SRP Waste Package Program Plan. This document is intended to outline how the SRP plans to develop the waste package design and to show, with reasonable assurance, that the developed design will satisfy applicable requirements/performance objectives. 44 refs., 16 figs., 16 tabs

  6. Assessment of Savannah River borosilicate glass in the repository environment

    International Nuclear Information System (INIS)

    Plodinec, M.J.; Wicks, G.G.; Bibler, N.E.

    1982-04-01

    Since 1973, borosilicate glass has been studied as a matrix for the immobilization of high-level radioactive waste generated at the Savannah River Plant (SRP). In 1977, efforts began to develop and test the large-scale equipment necessary to convert the alkaline waste slurries at SRP into a durable borosilicate glass. A process has now been developed for the proposed Defense Waste Processing Facility (DWPF) which will annually produce approximately 500 canisters of SRP waste glass which will be stored on an interim basis on the Savannah River site. Current national policy calls for the permanent disposal of high-level waste in deep geologic repositories. In the repository environment, SRP waste glass will eventually be exposed to such stresses as lithostatic or hydrostatic pressures, radiation fields, and self-heating due to radioactive decay. In addition, producing and handling each canister of glass will also expose the glass to thermal and mechanical stresses. An important objective of the extensive glass characterization and testing programs of the Savannah River Laboratory (SRL) has been to determine how these stresses affect the performance of SRP waste glass. The results of these programs indicate that: these stresses will not significantly affect the performance of borosilicate glass containing SRP waste; and SRP waste glass will effectively immobilize hazardous radionuclides in the repository environment

  7. Radioactive waste disposal: Recommendations for a repository site selection

    International Nuclear Information System (INIS)

    Cadelli, N.; Orlowski, S.

    1992-01-01

    This report is a guidebook on recommendations for site selection of radioactive waste repository, based on a consensus in european community. This report describes particularly selection criteria and recommendations for radioactive waste disposal in underground or ground repositories. 14 refs

  8. Gabbro as a host rock for a nuclear waste repository

    International Nuclear Information System (INIS)

    Ahlbom, K.; Leijon, B.; Smellie, J.; Liedholm, M.

    1992-09-01

    As an alternative to granitic rocks, gabbro and other basic rock types have been investigated with respect to their suitability to host a nuclear waste repository. The present report summarizes and examines existing geoscientific knowledge of relevance in assessing the potential merits of gabbro as a repository host rock. Implications in terms of site selection, repository construction and post-closure repository performance are also discussed. The objective of the study is to provide a basis for decisions as regards future consideration of the gabbro alternative. It is found that there are rather few gabbro bodies in Sweden, that are potentially of sufficient size to host a repository. Thus, gabbro offers little latitude as regards site selection. In comparison to siting a repository in granitic rocks, this is a major disadvantage, and it may in fact remove gabbro from further consideration. The potential advantages of gabbro refer to repository performance, and include low hydraulic conductivity and a chemical environment promoting efficient radionuclide retardation. However, results from field investigations show that groundwater flow in gabbro bodies is largely controlled by intersecting heterogeneities, in particular granitic dykes, that are significantly more conductive to water than the gabbro. In the far-field scale significant to repository performance, this may reduce or eliminate the potential effects of favourable hydraulic and chemical characteristics of the gabbro itself. In conclusion, there are apparent difficulties associated with siting a repository in gabbro, due to lack of sufficiently large gabbro bodies. On the basis of the present state of knowledge, no decisive differences can be demonstrated when comparing gabbro with granitic rocks, neither with respects to repository construction, nor as regards repository performance. (au)

  9. Environmentally assisted cracking mechanisms in repository environments

    International Nuclear Information System (INIS)

    Mills, W.J.

    1987-02-01

    This paper assesses how environmentally assisted cracking (EAC) mechanisms in candidate container materials can be identified to enhance the accuracy of long-term projections of performance in the repository. In low and intermediate strength steels, the role of the two principal mechanisms, slip dissolution/film rupture (SD/FR) and hydrogen embrittlement (HE), is a very complex and controversial issue. No unanimity exists concerning the operative cracking mechanisms, and there is no unique or rigorous approach that would be persuasive in selecting an appropriate model. Both of the proposed mechanisms have common rate controlling processes such as surface adsorption rate, passivation rate, and oxidation rupture rate, which makes it difficult to identify the operative mechanism. Development of a quantitative model for predicting environmental effects for low-carbon steels in repository environments would provide a theoretical basis for assuring the long-term structural integrity of waste-package containment. To date, only one quantitative model has been developed. The agreement between predicted and observed behavior suggests that SD/FR processes control the environmental acceleration in crack growth rates for this class of materials. Deviations from predicted behavior due to HE effects should be uncovered experimentally. 59 refs., 4 figs., 4 tabs

  10. Preliminary waste acceptance requirements - Konrad repository project

    International Nuclear Information System (INIS)

    Brennecke, P.W.; Warnecke, E.H.

    1991-01-01

    In Germany, the planned Konrad repository is proposed for the disposal of all types of radioactive wastes whose thermal influence upon the host rock is negligible. The Bundesamt fuer Strahlenschutz has established Preliminary Waste Acceptance Requirements (as of April 1990) for this facility. The respective requirements were developed on the basis of the results of site-specific safety assessments. They include general requirements on the waste packages to be disposed of as well as more specific requirements on the waste forms, the packaging and the radionuclide inventory per waste package. In addition, the delivery of waste packages was regulated. An outline of the structure and the elements of the Preliminary Waste Acceptance Requirements of April 1990 is given including comments on their legal status. (Author)

  11. Researching radioactive waste disposal. [Underground repository

    Energy Technology Data Exchange (ETDEWEB)

    Feates, F; Keen, N [UKAEA Research Group, Harwell. Atomic Energy Research Establishment

    1976-02-16

    At present it is planned to use the vitrification process to convert highly radioactive liquid wastes, arising from nuclear power programme, into glass which will be contained in steel cylinders for storage. The UKAEA in collaboration with other European countries is currently assessing the relative suitability of various natural geological structures as final repositories for the vitrified material. The Institute of Geological Sciences has been commissioned to specify the geological criteria that should be met by a rock structure if it is to be used for the construction of a repository though at this stage disposal sites are not being sought. The current research programme aims to obtain basic geological data about the structure of the rocks well below the surface and is expected to continue for at least three years. The results in all the European countries will then be considered so that the United Kingdom can choose a preferred method for isolating their wastes. It is only at that stage that a firm commitment may be made to select a site for a potential repository, when a far more detailed scientific research study will be instituted. Heat transfer problems and chemical effects which may occur within and around repositories are being investigated and a conceptual design study for an underground repository is being prepared.

  12. Characteristics of potential repository wastes

    International Nuclear Information System (INIS)

    1992-07-01

    This document, and its associated appendices and microcomputer (PC) data bases, constitutes the reference OCRWM data base of physical and radiological characteristics data of radioactive wastes. This Characteristics Data Base (CDB) system includes data on spent nuclear fuel and high-level waste (HLW), which clearly require geologic disposal, and other wastes which may require long-term isolation, such as sealed radioisotope sources. The data base system was developed for OCRWM by the CDB Project at Oak Ridge National Laboratory. Various principal or official sources of these data provided primary information to the CDB Project which then used the ORIGEN2 computer code to calculate radiological properties. The data have been qualified by an OCRWM-sponsored peer review as suitable for quality-affecting work meeting the requirements of OCRWM's Quality Assurance Program. The wastes characterized in this report include: light-water reactor (LWR) spent fuel and immobilized HLW

  13. The German quality system for waste repositories

    International Nuclear Information System (INIS)

    Beckmerhagen, I.; Berg, H.P.; Brennecke, P.

    1993-01-01

    The Bundesamt fuer Strahlenschutz (BfS)--Federal Office for Radiation protection--has to guarantee that the requirements resulting from different regulations concerning planning, design, construction, operation and decommissioning of a waste repository are fulfilled. In addition, the results of the safety assessments lead to nuclear-specific requirements on the design of the plant as well as to requirements on the radioactive waste packages intended to be disposed of. Therefore, the implementation of a quality assurance (QA) and quality control (QC) system is an essential task in order to ensure that the designed quality is achieved so that the necessary precaution against damage is taken. In this paper, a detailed description of QA and QC to be applied to the planned Konrad repository as well as the basic principles and the present status of the waste package QC are indicated and discussed

  14. Extreme scenarios for nuclear waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M J [Harvard Univ., Cambridge, MA (USA). Div. of Applied Sciences; Crouch, E [Harvard Univ., Cambridge, MA (USA). Energy and Environmental Policy Center

    1982-09-01

    Two extreme scenarios for release of radioactive waste have been constructed. In the first, a volcanic eruption releases 1 km/sup 2/ of an underground nuclear waste repository, while in the second, waste enters the drinking water reservoir of a major city. With pessimistic assumptions, upper bounds on the number of cancers due to radiation are calculated. In the volcano scenario, the effects of the waste are smaller than the effects of natural radioactivity in the volcanic dust if the delay between emplacement and eruption exceeds 2000 yr. The consequences of the waste in drinking water depend on the survival time of the canisters and the rate of leaching of the nuclides from the waste matrix. For a canister life of 400 yr and a leach time of 6300 yr the cancer rate in the affected area would increase by 25%.

  15. Repository waste-handling operations, 1998

    International Nuclear Information System (INIS)

    Cottam, A.E.; Connell, L.

    1986-04-01

    The Civilian Radioactive Waste Management Program Mission Plan and the Generic Requirements for a Mined Geologic Disposal System state that beginning in 1998, commercial spent fuel not exceeding 70,000 metric tons of heavy metal, or a quantity of solidified high-level radioactive waste resulting from the reprocessing of such a quantity of spent fuel, will be shipped to a deep geologic repository for permanent storage. The development of a waste-handling system that can process 3000 metric tons of heavy metal annually will require the adoption of a fully automated approach. The safety and minimum exposure of personnel will be the prime goals of the repository waste handling system. A man-out-of-the-loop approach will be used in all operations including the receipt of spent fuel in shipping casks, the inspection and unloading of the spent fuel into automated hot-cell facilities, the disassembly of spent fuel assemblies, the consolidation of fuel rods, and the packaging of fuel rods into heavy-walled site-specific containers. These containers are designed to contain the radionuclides for up to 1000 years. The ability of a repository to handle more than 6000 pressurized water reactor spent-fuel rods per day on a production basis for approximately a 23-year period will require that a systems approach be adopted that combines space-age technology, robotics, and sophisticated automated computerized equipment. New advanced inspection techniques, maintenance by robots, and safety will be key factors in the design, construction, and licensing of a repository waste-handling facility for 1998

  16. Stabilities of nuclear waste forms and their geochemical interactions in repositories

    International Nuclear Information System (INIS)

    White, W.B.

    1980-01-01

    The stabilities of high-level nuclear waste forms in a repository environment are briefly discussed. The advantages and disadvantages of such waste forms as borosilicate glass, supercalcine ceramics, and synthetic minerals are presented in context with the different rock types which have been proposed as possible host rocks for repositories. It is concluded that the growing geochemical evidence favors the use of a silicate rock repository because of the effectiveness of aluminosilicate rocks as chemical barriers for most radionuclides

  17. Extreme scenarios for nuclear waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Brown, M J; Crouch, E

    1982-09-01

    Two extreme scenarios for release of radioactive waste have been constructed. In the first, a volcanic eruption releases 1 km2 of an underground nuclear waste repository, while in the second, waste enters the drinking water reservoir of a major city. With pessimistic assumptions, upper bounds on the number of cancers due to radiation are calculated. In the volcano scenario, the effects of the water are smaller than the effects of natural radioactivity in the volcanic dust if the delay between emplacement and eruption exceeds 2000 yr. The consequences of the waste in drinking water depend on the survival time of the canisters and the rate of leaching of the nuclides from the waste matrix. For a canister life of 400 yr and a leach time of 6300 yr the cancer rate in the affected area would increase by 25%.

  18. National radioactive waste repository draft EIS. 2 volumes

    International Nuclear Information System (INIS)

    2002-01-01

    Most Australians benefit either directly or indirectly from the medical, industrial and scientific use of radioactive materials. This use produces a small amount of radioactive waste, including low level and short-lived intermediate level radioactive waste such as lightly contaminated soil, plastic, paper, laboratory equipment, smoke detectors, exit signs and gauges.This waste is temporarily stored at more than 100 urban and rural locations around Australia, much of it in buildings that were neither designed nor located for the long-term storage of radioactive material and that are nearing or have reached capacity. Storage locations include hospitals, research institutions, and industry and government stores. Storing such waste in many locations in non-purpose built facilities potentially poses greater risk to the environment and people than disposing of the material in a national, purpose-built repository where the material can be safely managed and monitored. The objectives of the national repository are to: 1. strengthen Australia's radioactive waste management arrangements by promoting the safe and environmentally sound management of low level and short-lived intermediate level radioactive waste 2. provide safe containment of these wastes until the radioactivity has decayed to background levels. To meet these objectives, it is proposed to construct a national near-surface repository at either the preferred site on the Woomera Prohibited Area (WPA) or either of the two nearby alternative sites. The facility is not intended for the disposal of radioactive ores from mining. A national store for long-lived intermediate level waste will not be co-located with the national repository, and would be subject to a separate environmental assessment process.One preferred and two alternative sites have been selected for the national repository, following an extensive site selection process. All three sites are located in northern South Australia in a region known as central

  19. Geological study of radioactive waste repositories

    International Nuclear Information System (INIS)

    Oyama, Takahiro; Kitano, Koichi

    1987-01-01

    The investigation of the stability and the barrier efficiency of the deep underground radioactive waste repositories become a subject of great concern. The purpose of this paper is to gather informations on the geology, engineering geology and hydrogeology in deep galleries in Japan. Conclusion can be summarised as follows: (1) The geological structure of deep underground is complicated. (2) Stress in deep underground is greatly affected by crustal movement. (3) Rock-burst phenomena occur in the deep underground excavations. (4) In spite of deep underground, water occasionally gush out from the fractured zone of rock mass. These conclusion will be useful for feasibility study of underground waste disposal and repositories in Japan. (author)

  20. Licensing information needs for a high-level waste repository

    International Nuclear Information System (INIS)

    Wright, R.J.; Greeves, J.T.; Logsdon, M.J.

    1985-01-01

    The information needs for licensing findings during the development of a repository for high-level waste (HLW) are described. In particular, attention is given to the information and needs to demonstrate, for construction authorization purposes: repository constructibility, waste retrievability, waste containment, and waste isolation

  1. Waste repository planned for Bruce Site

    International Nuclear Information System (INIS)

    King, F.

    2004-01-01

    Ontario Power Generation (OPG) and Kincardine, the municipality nearest the Bruce site, have agreed in principal to the construction of a deep geologic repository for low and medium level radioactive waste on the site. The two parties signed the 'Kincardine Hosting Agreement' on October 13, 2004 to proceed with planning, seek regulatory approval and further public consultation of the proposed project. A construction Licence is not expected before 2013. (author)

  2. Generic performance assessment for a deep repository for low and intermediate level waste in the UK - a case study in assessing radiological impacts on the natural environment

    International Nuclear Information System (INIS)

    Jones, S.R.; Patton, D.; Copplestone D.; Norris, S.; O'Sullivan, P.

    2003-01-01

    Concentrations of radionuclides in soil and surface water, taken from a generic performance assessment of a repository for low and intermediate level radioactive waste, assumed to be located in the UK, have been used as the basis for a case study in assessing radiological impacts on the natural environment. Simplified descriptions of the terrestrial and aquatic ecosystem types likely to be impacted have been developed. A scoping assessment has identified 226 Ra, 210 Po, 234 U, 230 Th and 238 U as having the highest potential for impact, with doses from internally incorporated alpha emitters as being potentially of particular importance. These nuclides, together with 36 Cl and 129 I (which have proved to be of importance in radiological risk assessments for humans) were included in a more detailed dose assessment. A basic methodology for dose assessment of ecosystems is described, and has been applied for the defined impacted ecosystems. Paucity of published data on concentration factors prevented a more detailed assessment for terrestrial ecosystems. For the aquatic ecosystem, a more detailed assessment was possible and highest calculated absorbed dose rates (weighted for the likely higher biological effectiveness of alpha radiation were about 6.5 μGy h -1 . We conclude that harm to the impacted ecosystems is unlikely and make the observation that the lack of concentration factor or transfer factor data for a sufficiently wide range of species, ecosystems and nuclides appears to be the principal obstacle to establishing a comprehensive framework for the application of radiological protection to ecosystems

  3. Biotic and abiotic catalysis of nitrate reduction in alkaline environment of repository storage cell for long-lived intermediate-level radioactive wastes

    International Nuclear Information System (INIS)

    Bertron, A.; Jacquemet, N.; Escadeillas, G.; Erable, B.; Alquier, M.; Kassim, C.; Albasi, C.; Basseguy, R.; Strehaiano, P.; Sablayrolles, C.; Vignoles, M.; Albrecht, A.

    2013-01-01

    This study investigates the reactivity of nitrates at the bitumen-concrete interface with the aim of determining redox conditions inside a repository storage cell for long-lived intermediate-level radioactive wastes. The first part of the work aimed to identify, under abiotic conditions, the interactions between two components of the system: concrete (introduced as cement pastes in the system) and bitumen (represented by leachates composed of organic acids and nitrates). The second part of the study was conducted under biotic conditions with selected denitrifying heterotrophic bacteria (Pseudomonas stutzeri - Ps and Halomonas desiderata - Hd) and aimed to analyse the microbial reaction of nitrate reduction (kinetics, by-products, role of the organic matter) under neutral to alkaline pH conditions (i.e. imposed by a concrete environment). Results showed that strong interactions occurred between cementitious matrices and acetic and oxalic organic acids, likely reducing the bio-availability of this organic matter (oxalate in particular). Results also confirmed the stability of nitrates under these conditions. Under biotic conditions, nitrates were reduced by both Ps and Hd following an anaerobic denitrification metabolic pathway. Reduction kinetics was higher with Ps but the reaction was inhibited for pH ≥ 9. Hd was capable of denitrification at least up to pH 11. (authors)

  4. Underground excavation methods for a high-level waste repository

    International Nuclear Information System (INIS)

    Peshel, J.; Gupta, D.; Nataraja, M.

    1990-01-01

    This paper reports on rock excavation methods for a High-Level Waste repository that should be selected to limit the potential for creating preferential pathways for groundwater to travel to the waste packages or for radionuclides to migrate to the accessible environment. The use of water and other foreign substances should be controlled so that the repository performance is not compromised. The excavated openings should remain stable so that operations can be carried out safely and the retrievability option maintained. As per the current conceptual designs presented by the Department of Energy, the exploratory shaft facility becomes a part of the repository if the Yucca Mountain site is found suitable for repository development. Therefore, the methods of constructing the underground openings should be compatible with the performance requirements for the repository. Also, the degree of damage to the rock surrounding the openings and the extent of the damage zone should not preclude adequate site characterization. The ESf construction and operation should be compatible with the site data gathering activities, such as geological, thermomechanical, hydrological and geochemical testing

  5. Assessment of cement durability in repository environment

    International Nuclear Information System (INIS)

    Ferreira, E.G.A.; Vicente, R.; Isiko, V.L.K.; Miyamoto, H.; Marumo, J.T.; Gobbo, L.A.

    2015-01-01

    The present research aimed at investigating the durability of cement paste under nuclear waste repository conditions using accelerated tests. Cement paste samples are examined after being exposed to the environmental conditions that are expected to prevail in the repository environment and the results are compared with those obtained with unexposed specimens or specimens exposed to reference conditions. The following exposure conditions were selected: a) Immersion in salt solution, distilled water, or kept in dry storage; b) Room temperature (20 C. degrees) or high temperature (60 C. degrees); c) Immersion time of 30 days or 60 days (not for dry storage); d) Irradiation to a dose of (400 kGy) or background radiation (0 kGy). After exposure to the stressing conditions, the effects of each factor on the cement paste samples were observed by changes in their characteristics. Compressive strength tests were performed on all samples and some of them were investigated in terms of changes in mineralogy by X-ray diffraction (XRD) and thermo-gravimetric analysis (TGA). With the results obtained so far it was possible to point out the following conclusions. First, after a period of immersion in water, cement paste samples further hydrated and presented higher mechanical resistance, as expected. Secondly, dry storage did not allow a complete hydration as a consequence of pore water evaporation. High temperatures intensified this process and led to the ettringite decomposition to meta-ettringite. Thirdly, higher temperature accelerated hydration kinetics and promoted higher mechanical resistance in samples kept under immersion. Fourthly, the irradiation dose applied was unable to change the mineralogy of cement paste samples and fifthly, no statistically significant differences were observed between 30 or 60 days exposure time, for the test conditions

  6. International high-level radioactive waste repositories

    International Nuclear Information System (INIS)

    Lin, W.

    1996-01-01

    Although nuclear technologies benefit everyone, the associated nuclear wastes are a widespread and rapidly growing problem. Nuclear power plants are in operation in 25 countries, and are under construction in others. Developing countries are hungry for electricity to promote economic growth; industrialized countries are eager to export nuclear technologies and equipment. These two ingredients, combined with the rapid shrinkage of worldwide fossil fuel reserves, will increase the utilization of nuclear power. All countries utilizing nuclear power produce at least a few tens of tons of spent fuel per year. That spent fuel (and reprocessing products, if any) constitutes high-level nuclear waste. Toxicity, long half-life, and immunity to chemical degradation make such waste an almost permanent threat to human beings. This report discusses the advantages of utilizing repositories for disposal of nuclear wastes

  7. 500 year concrete for a radioactive waste repository

    International Nuclear Information System (INIS)

    Philipose, K.E.

    1988-03-01

    The IRUS (Intrusion resistant underground structure) repository planned at Chalk River for the belowground disposal of low level radioactive waste relies on the durability of concrete for the required 500 year service life. A research program for the IRUS repository to design a durable concrete and also to predict its longevity under the repository environment is in progress. The methodology involves the identification of major degradation agents, and the assessment of the rate of diffusion of corrosive ions and/or the rate of advancement of the reaction front into the concrete. Accelerated test methods are being used on laboratory specimens in conjunction with extrapolation procedures to predict long-term durability from short-term data. The inherent limitations are also examined

  8. Natural analogues, paradigm for manmade repositories for radioactive wastes

    International Nuclear Information System (INIS)

    Pavelescu, M.; Pavelescu, A.

    2004-01-01

    Natural analogues are given by nature. They show the results of natural processes which have lasted thousands or millions of years. They provide an excellent example of what could happen in an underground site, offering in the same time the opportunity to test by observation and measurement, many of the geochemical processes that are expected to influence in a realistic and appropriate way, the predicted reliability of the radioactive waste repository over long periods of geological time. The natural analogue studies attempt to understand the multiprocessing complexity of the natural system, which contrasts with the limitations of the laboratory experiments and bring arguments to overcome the difficult time scale issue. By this the natural analogues are a useful paradigm for manmade repository for radioactive wastes. The paper discusses the implicit link in the public mind between natural analogues and manmade waste repository with an accent of the positive impact on public acceptance. It is also discussed the decisive qualities of the natural analogues concerning providing valid long term data and increasing the confidence of the public for manmade repositories. The debate is conducting in terms of sustainable development, having at base high-level principles in order to protect humans and their environment, both now and in the future, from potential hazards arising from such wastes. Safe radwaste management involves the application of technology and resources in a regulated manner so that the public, workers and the environment are protected in accordance with the accepted national and international standards. There are at least seven high-level principles which are mentioned in the paper. It is presented the general concept of the deep geological repository, very important for an acceptable solution for the management of nuclear waste, what is a prerequisite for a renewal of nuclear power. Further are introduced natural and archaeological (manufactured) analogue

  9. Repository Waste Package Transporter Shielding Weight Optimization

    International Nuclear Information System (INIS)

    C.E. Sanders; Shiaw-Der Su

    2005-01-01

    The Yucca Mountain repository requires the use of a waste package (WP) transporter to transport a WP from a process facility on the surface to the subsurface for underground emplacement. The transporter is a part of the waste emplacement transport systems, which includes a primary locomotive at the front end and a secondary locomotive at the rear end. The overall system with a WP on board weights over 350 metric tons (MT). With the shielding mass constituting approximately one-third of the total system weight, shielding optimization for minimal weight will benefit the overall transport system with reduced axle requirements and improved maneuverability. With a high contact dose rate on the WP external surface and minimal personnel shielding afforded by the WP, the transporter provides radiation shielding to workers during waste emplacement and retrieval operations. This paper presents the design approach and optimization method used in achieving a shielding configuration with minimal weight

  10. Performance Assessments of Generic Nuclear Waste Repositories in Shale

    Science.gov (United States)

    Stein, E. R.; Sevougian, S. D.; Mariner, P. E.; Hammond, G. E.; Frederick, J.

    2017-12-01

    Simulations of deep geologic disposal of nuclear waste in a generic shale formation showcase Geologic Disposal Safety Assessment (GDSA) Framework, a toolkit for repository performance assessment (PA) whose capabilities include domain discretization (Cubit), multiphysics simulations (PFLOTRAN), uncertainty and sensitivity analysis (Dakota), and visualization (Paraview). GDSA Framework is used to conduct PAs of two generic repositories in shale. The first considers the disposal of 22,000 metric tons heavy metal of commercial spent nuclear fuel. The second considers disposal of defense-related spent nuclear fuel and high level waste. Each PA accounts for the thermal load and radionuclide inventory of applicable waste types, components of the engineered barrier system, and components of the natural barrier system including the host rock shale and underlying and overlying stratigraphic units. Model domains are half-symmetry, gridded with Cubit, and contain between 7 and 22 million grid cells. Grid refinement captures the detail of individual waste packages, emplacement drifts, access drifts, and shafts. Simulations are run in a high performance computing environment on as many as 2048 processes. Equations describing coupled heat and fluid flow and reactive transport are solved with PFLOTRAN, an open-source, massively parallel multiphase flow and reactive transport code. Additional simulated processes include waste package degradation, waste form dissolution, radioactive decay and ingrowth, sorption, solubility, advection, dispersion, and diffusion. Simulations are run to 106 y, and radionuclide concentrations are observed within aquifers at a point approximately 5 km downgradient of the repository. Dakota is used to sample likely ranges of input parameters including waste form and waste package degradation rates and properties of engineered and natural materials to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia National

  11. Training courses on integrated safety assessment modelling for waste repositories

    International Nuclear Information System (INIS)

    Mallants, D.

    2007-01-01

    Near-surface or deep repositories of radioactive waste are being developed and evaluated all over the world. Also, existing repositories for low- and intermediate-level waste often need to be re-evaluated to extend their license or to obtain permission for final closure. The evaluation encompasses both a technical feasibility as well as a safety analysis. The long term safety is usually demonstrated by means of performance or safety assessment. For this purpose computer models are used that calculate the migration of radionuclides from the conditioned radioactive waste, through engineered barriers to the environment (groundwater, surface water, and biosphere). Integrated safety assessment modelling addresses all relevant radionuclide pathways from source to receptor (man), using in combination various computer codes in which the most relevant physical, chemical, mechanical, or even microbiological processes are mathematically described. SCK-CEN organizes training courses in Integrated safety assessment modelling that are intended for individuals who have either a controlling or supervising role within the national radwaste agencies or regulating authorities, or for technical experts that carry out the actual post-closure safety assessment for an existing or new repository. Courses are organised by the Department of Waste and Disposal

  12. Commercial nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Hardy, M.P.; Patricio, J.G.; Heley, W.H.

    1980-06-01

    The Basalt Waste Isolation Project (BWIP) is an ongoing research and engineering effort being conducted by Rockwell Hanford Operations (Rockwell), which is under contract to the US Department of Energy. The objectives of this program are to assess the feasibility of and to provide the technology needed to design and construct a licensed commercial nuclear waste repository in the deep basalt formations underlying the Hanford Site. An extensive preconceptual design effort was undertaken during 1979 to develop a feasible concept that could serve as a reference design for both surface and underground facilities. The preconceptual design utilized existing technology to the greatest extent possible to offer a system design that could be utilized in establishing schedule and cost baseline data, recommend alternatives that require additional study, and develop basic design requirements that would allow evolution of the design process prior to the existence of legislated criteria. This paper provides a description of the concept developed for the subsurface aspects of this nuclear waste repository

  13. Assessment of the Durability of Cementitious Materials in Repository Environment

    International Nuclear Information System (INIS)

    Vicente, R.; Marumo, J.T.; Miyamoto, H.; Isiki, V.L.K.; Ferreira, E.G.

    2013-01-01

    The Radioactive Waste Management Laboratory of the Energy and Nuclear Research Institute is developing the concept of a borehole repository for disused sealed radioactive sources drilled in a deep granite batholite. In this concept, the annular space between the well steel casing and the geological formation is backfilled with cement paste. The hardened cement paste functions as an additional barrier against the escape of radionuclides from the repository and their migration to the environment. It also functions as an obstacle to the flow of groundwater between different layers of the geological setting crossed by the borehole. The long term behavior of hydrated cement compounds is yet incompletely known and therefore more research is needed to increase the confidence on the performance of the material under the repository conditions as required. For the repository to achieve the required performance, the cement paste must be durable. However, in a deep repository, the cementitious materials is exposed to the deleterious action of high temperatures and pressures, the radiation field created by the radioactive sources and aggressive ion species that may be present in groundwater. Furthermore, it is necessary to consider that the cement paste is unstable in the long term because its microstructure and mineralogy change with time as the cement gel components recrystallize and react chemically with materials of the repository environment. In principle, the lifetime of this material could be determined based on the study of its long-term behavior, which, in turn, could be estimated from the extrapolation of short-term results, by accelerating, under controlled laboratory conditions, the composition changes and the loss of mechanical strength and cohesion induced by any detrimental component of the repository environment. Loss of mechanical strength, dimensional variations, changes in chemical-mineralogical composition, and leaching of hydrate compounds are all possible

  14. Hydrogen modelling for vitrified wastes repository

    International Nuclear Information System (INIS)

    Voinis, S.; Breton, J.

    1992-01-01

    Safety assessments for High Level Wastes (HLW) have led ANDRA (Agence Nationale pour la gestion des Dechets Radioactifs) to study the occurrence of a gas production rate in a repository. This paper deals with the description of an analytical model used for the gas production rate assessment and brings us the first results. The geometry used is restrained to a single borehole associated with a drift in a crystalline formation. Different concepts were studied in this assessment. First results have been obtained. For example, in the case of a permeable plug, the saturation time of the borehole is about 300 years. 5 refs., 5 figs

  15. Types of safety assessments of near surface repository for radioactive waste

    International Nuclear Information System (INIS)

    Mateeva, M.

    2004-01-01

    The purpose of this article is to presents the classification of different types safety assessments of near surface repository for low and intermediate level radioactive waste substantiated with results of safety assessments generated in Bulgaria. The different approach of safety assessments applied for old existing repository as well as for site selection for construction new repository is outlined. The regulatory requirements in Bulgaria define three main types of assessments: Safety assessment; Technical substation of repository safety; Assessment of repository influence on environment that is in form of report prepared from the Ministry of environment and waters on the base of results obtained in two first types of assessments. Additionally first type is subdivided in three categories - preliminary safety assessment, safety assessment and post closure safety assessment, which are generated using deterministic approach. The technical substation of repository safety is generated using probabilistic approach. Safety assessment results that are presented here are based on evaluation of existing old repository type 'Radon' in Novi Han and real site selection procedure for new near surface repository for low and intermediate level radioactive waste from nuclear power station in Kozloduy. The important role of safety assessment for improvement the repository safety as well as for repository licensing, correct site selection and right choice of engineer barriers and repository design is discussed using generated results. (author)

  16. Integrity of radioactive waste packages at the Yucca mountain repository

    International Nuclear Information System (INIS)

    Sandquist, G.; Biaglow, A.; Huber, M.; Jagmin, C.

    2004-01-01

    Several of the important physical and chemical processes that impact the integrity of the radioactive waste packages planned for disposal at the proposed Repository at Yucca Mountain are examined. These processes are described by the aerodynamic, thermodynamic, and chemical interactions associated with the waste packages. The effects of chemical corrosion, mechanical erosion, temperature distributions throughout the repository environs, interactions of air, water, and solid particles, and radiological and biological influences are addressed. Materials will be exposed to at least 3 conditions threatening the integrity of the waste package: 1) accumulated dust and particles on the package surface and suspended in the air, 2) chemical reactions from deposits on the waste package infrastructure materials and tight contact areas, and crevices, and 3) environmental factors affecting chemical reactions such as moisture, pH, Eh, and radiolysis. All 3 of these conditions can combine and produce damaging impacts upon the thin protective layer on the alloy surface of the waste package. There are certain benefits from the low-temperature operating mode with ambient temperature below 85 Celsius degrees, but the materials could be subjected to a maximum temperature of 180 Celsius degrees which might introduce stress corrosion cracking and high temperature effects

  17. Scientific basis for long-term prediction of waste-form performance under repository conditions

    International Nuclear Information System (INIS)

    Mendel, J.E.

    1982-10-01

    This paper presents an overview of the fundamental principles involved in predicting long-term performance of waste forms by the as-low-as-reasonably-achievable approach. Repository conditions which make up the waste-form environment, the aging of the waste form, the important radionuclides in the waste form, the chemistry of repository fluids, and multicomponent interactions testing were considered in order to describe these principles. The need for confidence limits on the prediction of waste-form performance and ways of achieving a definition of the confidence limits are discussed

  18. Durability of cemented waste in repository and under simulated conditions

    International Nuclear Information System (INIS)

    Dragolici, F.; Nicu, M.; Lungu, L.; Turcanu, C.; Rotarescu, Gh.

    2000-01-01

    The Romanian Radioactive Waste National Repository for low level and intermediate level radioactive waste was built in Baita - Bihor county, in an extinct uranium exploitation. The site is at 840 m above sea level and the host rock is crystalline with a low porosity, a good chemical homogeneity and impermeability, keeping these qualities over a considerable horizontal and vertical spans. To obtain the experimental data necessary for the waste form and package characterization together with the back-filling material behaviour in the repository environment, a medium term research programme (1996 - 2010) was implemented. The purpose of this experimental programme is to obtain a part of the data base necessary for the approach of medium and long term assessment of the safety and performance of Baita - Bihor Repository. The programme will provide: a deeper knowledge of the chemical species and reaction mechanisms, the structure, properties and performances of the final products. For safety reasons the behaviour of waste package, which is a main barrier, must be properly known in terms of long term durability in real repository conditions. Characterization of the behaviour includes many interactions between the waste package itself and the surrounding near field conditions such as mineralogy, hydrogeology and groundwater chemistry. To obtain a more deeper knowledge of the species and physical-chemical reactions participating in the matrix formation, as well as their future behaviour during the disposal period, a thorough XRD study started in 1998. For Romanian Radioactive Waste National Repository (DNDR) Baita - Bihor the following steps are planned for the conditioned waste matrix characterization in simulated and real conditions: - preparation and characterization of normal reference matrices based on different cement formulations; - preparation of reference simulated sludge cemented matrices containing iron hydroxide and iron phosphate; - selection of real and

  19. Monitoring of covering model of the National radioactive waste repository

    International Nuclear Information System (INIS)

    Jezikova, M.

    2009-01-01

    The subject of this rigorous report is justification of cover model building at radioactive waste repository in Mochovce as a very important engineering barrier preventing significant release of radioactive substances into the environment and providing protection against ionizing radiation. This rigorous report includes a theoretical part, which describes radioactive waste characterization, radioactive waste management and summary of the preliminary activities prior to the building cover model, particularly involving the selection of appropriate variables and parameters and creation of monitoring plan during the long term monitoring for evaluation of this barrier in order to ensure minimization of any leak of radioactive substances from RAW. The next part includes evaluation of the values of parameters and variables to build cover model of RAW in Mochovce during 2006-2008 (author)

  20. Testing of high-level waste forms under repository conditions

    International Nuclear Information System (INIS)

    Mc Menamin, T.

    1989-01-01

    The workshop on testing of high-level waste forms under repository conditions was held on 17 to 21 October 1988 in Cadarache, France, and sponsored by the Commission of the European Communities (CEC), the Commissariat a l'energie atomique (CEA) and the Savannah River Laboratory (US DOE). Participants included representatives from Australia, Belgium, Denmark, France, Germany, Italy, Japan, the Netherlands, Sweden, Switzerland, The United Kingdom and the United States. The first part of the conference featured a workshop on in situ testing of simulated nuclear waste forms and proposed package components, with an emphasis on the materials interface interactions tests (MIIT). MIIT is a sevent-part programme that involves field testing of 15 glass and waste form systems supplied by seven countries, along with potential canister and overpack materials as well as geologic samples, in the salt geology at the Waste Isolation Pilot Plant (WIPP) in Carlsbad, New Mexico, USA. This effort is still in progress and these proceedings document studies and findings obtained thus far. The second part of the meeting emphasized multinational experimental studies and results derived from repository systems simulation tests (RSST), which were performed in granite, clay and salt environments

  1. Informing future societies about nuclear waste repositories

    International Nuclear Information System (INIS)

    Jensen, M.

    1994-01-01

    In 1990 a working group of the NKS (the Nordic nuclear safety program) was formed and give the task of established a basis for a common Nordic view of the need for information conservation for nuclear waste repositories. The Group investigated what tipy of information should be conserved; in what form the information should be kept; the quality of the information; and the problems of future retrieval of information, including retrieval after very long periods of time. Topics covered include the following: scientific aspects including social context of scientific solutions; information management; systems for conservation and retrieval of information including the problems of prediction; archives, markers, archives vs. markers, and continuing processes in society; Archive media including paper documents, microfilm, digital media, media lifetimes; and finally conclusions and recommendations

  2. Waste package/repository impact study: Final report

    Energy Technology Data Exchange (ETDEWEB)

    1985-09-01

    The Waste Package/Repository Impact Study was conducted to evaluate the feasibility of using the current reference salt waste package in the salt repository conceptual design. All elements of the repository that may impact waste package parameters, i.e., (size, weight, heat load) were evaluated. The repository elements considered included waste hoist feasibility, transporter and emplacement machine feasibility, subsurface entry dimensions, feasibility of emplacement configuration, and temperature limits. The evaluations are discussed in detail with supplemental technical data included in Appendices to this report, as appropriate. Results and conclusions of the evaluations are discussed in light of the acceptability of the current reference waste package as the basis for salt conceptual design. Finally, recommendations are made relative to the salt project position on the application of the reference waste package as a basis for future design activities. 31 refs., 11 figs., 11 tabs.

  3. Waste package/repository impact study: Final report

    International Nuclear Information System (INIS)

    1985-09-01

    The Waste Package/Repository Impact Study was conducted to evaluate the feasibility of using the current reference salt waste package in the salt repository conceptual design. All elements of the repository that may impact waste package parameters, i.e., (size, weight, heat load) were evaluated. The repository elements considered included waste hoist feasibility, transporter and emplacement machine feasibility, subsurface entry dimensions, feasibility of emplacement configuration, and temperature limits. The evaluations are discussed in detail with supplemental technical data included in Appendices to this report, as appropriate. Results and conclusions of the evaluations are discussed in light of the acceptability of the current reference waste package as the basis for salt conceptual design. Finally, recommendations are made relative to the salt project position on the application of the reference waste package as a basis for future design activities. 31 refs., 11 figs., 11 tabs

  4. Classifying decommissioning wastes for allocation to appropriate final repositories

    International Nuclear Information System (INIS)

    Alder, J.C.; Tunaboylu, K.

    1982-01-01

    For the safe disposal of radioactive wastes in different repositories, it is of advantage to classify them in well-defined conditioned categories, appropriate for final disposal. These categories, the so-called waste sorts are characterized by similar radionuclide distribution, similar nuclide-specific activity concentrations and similar waste matrix. A methodology is presented for classifying decommissioning wastes and is applied to the decommissioning wastes arising from a Swiss program of 6 GWe. The amounts and nuclide-specific activity inventories of the decommissioning waste sorts have been estimated. A first allocation into two different repository types has been performed. Such a classification enables one to define the source parameters for repository safety analysis and allows one to allocate the different waste categories into appropriate final repositories. This work presents a first iteration to determine which waste sorts belong to which repository type. The characteristics of waste sorts have to be better defined and the protective strength of the repository barriers has to be optimized. 7 references, 2 figures, 4 tables

  5. Characteristics of potential repository wastes. Volume 2

    Energy Technology Data Exchange (ETDEWEB)

    1992-07-01

    The LWR spent fuels discussed in Volume 1 of this report comprise about 99% of all domestic non-reprocessed spent fuel. In this report we discuss other types of spent fuels which, although small in relative quantity, consist of a number of diverse types, sizes, and compositions. Many of these fuels are candidates for repository disposal. Some non-LWR spent fuels are currently reprocessed or are scheduled for reprocessing in DOE facilities at the Savannah River Site, Hanford Site, and the Idaho National Engineering Laboratory. It appears likely that the reprocessing of fuels that have been reprocessed in the past will continue and that the resulting high-level wastes will become part of defense HLW. However, it is not entirely clear in some cases whether a given fuel will be reprocessed, especially in cases where pretreatment may be needed before reprocessing, or where the enrichment is not high enough to make reprocessing attractive. Some fuels may be canistered, while others may require special means of disposal. The major categories covered in this chapter include HTGR spent fuel from the Fort St. Vrain and Peach Bottom-1 reactors, research and test reactor fuels, and miscellaneous fuels, and wastes generated from the decommissioning of facilities.

  6. Problem trap final repository. Social challenges concerning nuclear waste

    International Nuclear Information System (INIS)

    Brunnengraeber, Achim

    2016-01-01

    How is it possible that there is still no final storage facility in the entire world for highly radioactive waste from nuclear power stations? How is it possible that electricity has been generated by industrial-scale nuclear installations for decades without the issue of the disposal of nuclear waste having been resolved? The events in Chernobyl in 1986 and Fukushima in 2011 have made it blatantly obvious how risky this technology is and how important it is to keep humans and the environment at a safe distance from radioactivity. This anthology examines the technological, political, social and economic dimensions of the permanent disposal of nuclear waste. It provides an insight into the emergence of the problem and the people involved and their interests. It describes and analyses the changes that are taking place in Germany (for instance, in relation to the government's commission on nuclear repositories) and other countries with regard to how they handle nuclear waste. The book deals with both questions related to socio-technical aspects of the permanent disposal of nuclear waste and calls for the democratic need for participation and new ways of doing so, without which the search for a permanent disposal site will not bear fruit. This anthology presents a comprehensive discussion of the disposal of nuclear waste and the search for a permanent repository for it. Not only will students and teachers find it extremely useful, but so will any readers who are interested in its subject matter and wish to gain a more in-depth insight into it.

  7. Site selection for deep geologic repositories - Consequences for society, economy and environment

    International Nuclear Information System (INIS)

    2010-03-01

    In a few years, Switzerland will make the decision regarding site selection for geological underground repositories for the storage of radioactive wastes. Besides the safety issue, many citizens are interested in how such a repository will affect environment, economy and society in the selected site's region. This brochure summarizes the results of many studies on the socio-economic impacts of nuclear waste repositories. Radioactive wastes must be stored in such a way that mankind and environment are safely protected for a long period of time. How this goal may be achieved, is already known: geologic deep repositories warrant long-term safety. For the oncoming years in Switzerland the question is where the repository will be built. The search for an appropriate site for a repository in the proposed regions will launch discussions. Within the participative framework the regions may bring their requests. The demonstration of the safety of potential repository sites has the highest priority in the selection process. In the third procedural step additional rock investigations will be made. The socio-economic studies and the experience with existing plants show that radioactive waste management plants can be built and operated in good agreement with environmental requirements. The radioactive wastes in a deep underground repository are stored many hundred meters below the Earth's surface. There, they are isolated from our vital space. Technical barriers and the surrounding dense rock confinement prevent the release of radioactive materials into the environment. A deep repository has positive consequences for the regional economy. It increases trade and value creation and creates work places. The socio-economic impacts practically extend over one century, but strongly vary with time; they are the largest during the building period. High life quality and a positive population development in the selected site region are compatible with a deep repository. A fair and

  8. Microbial corrosion of metallic materials in a deep nuclear-waste repository

    Directory of Open Access Journals (Sweden)

    Stoulil J.

    2016-06-01

    Full Text Available The study summarises current knowledge on microbial corrosion in a deep nuclear-waste repository. The first part evaluates the general impact of microbial activity on corrosion mechanisms. Especially, the impact of microbial metabolism on the environment and the impact of biofilms on the surface of structure materials were evaluated. The next part focuses on microbial corrosion in a deep nuclear-waste repository. The study aims to suggest the development of the repository environment and in that respect the viability of bacteria, depending on the probable conditions of the environment, such as humidity of bentonite, pressure in compact bentonite, the impact of ionizing radiation, etc. The last part is aimed at possible techniques for microbial corrosion mechanism monitoring in the conditions of a deep repository. Namely, electrochemical and microscopic techniques were discussed.

  9. Constructibility issues associated with a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Turner, D.A.

    1981-01-01

    This report contains the text and slide reproductions of a speech on nuclear waste disposal in basalt. The presentation addresses the layout of repository access shafts and subsurface facilities resulting from the conceptual design of a nuclear repository in basalt. The constructibility issues that must be resolved prior to construction are described

  10. An analysis of repository waste-handling operations

    International Nuclear Information System (INIS)

    Dennis, A.W.

    1990-09-01

    This report has been prepared to document the operational analysis of waste-handling facilities at a geologic repository for high-level nuclear waste. The site currently under investigation for the geologic repository is located at Yucca Mountain, Nye County, Nevada. The repository waste-handling operations have been identified and analyzed for the year 2011, a steady-state year during which the repository receives spent nuclear fuel containing the equivalent of 3000 metric tons of uranium (MTU) and defense high-level waste containing the equivalent of 400 MTU. As a result of this analysis, it has been determined that the waste-handling facilities are adequate to receive, prepare, store, and emplace the projected quantity of waste on an annual basis. In addition, several areas have been identified where additional work is required. The recommendations for future work have been divided into three categories: items that affect the total waste management system, operations within the repository boundary, and the methodology used to perform operational analyses for repository designs. 7 refs., 48 figs., 11 tabs

  11. Tunnel Boring Machine for nuclear waste repository research project

    International Nuclear Information System (INIS)

    Janzon, H.A.

    1994-01-01

    A description is presented of a Tunnel Boring Machine and its intended use on a research project underway in Sweden for demonstrating and testing methods for rock investigation at a suitable depth for a deep repository for nuclear waste

  12. Multibarrier system preventing migration of radionuclides from radioactive waste repository

    Directory of Open Access Journals (Sweden)

    Olszewska Wioleta

    2015-09-01

    Full Text Available Safety of radioactive waste repositories operation is associated with a multibarrier system designed and constructed to isolate and contain the waste from the biosphere. Each of radioactive waste repositories is equipped with system of barriers, which reduces the possibility of release of radionuclides from the storage site. Safety systems may differ from each other depending on the type of repository. They consist of the natural geological barrier provided by host rocks of the repository and its surroundings, and an engineered barrier system (EBS. The EBS may itself comprise a variety of sub-systems or components, such as waste forms, canisters, buffers, backfills, seals and plugs. The EBS plays a major role in providing the required disposal system performance. It is assumed that the metal canisters and system of barriers adequately isolate waste from the biosphere. The evaluation of the multibarrier system is carried out after detailed tests to determine its parameters, and after analysis including mathematical modeling of migration of contaminants. To provide an assurance of safety of radioactive waste repository multibarrier system, detailed long term safety assessments are developed. Usually they comprise modeling of EBS stability, corrosion rate and radionuclide migration in near field in geosphere and biosphere. The principal goal of radionuclide migration modeling is assessment of the radionuclides release paths and rate from the repository, radionuclides concentration in geosphere in time and human exposure to ionizing radiation

  13. Anticipated Degradation Modes of Metallic Engineered Barriers for High-Level Nuclear Waste Repositories

    Science.gov (United States)

    Rodríguez, Martín A.

    2014-03-01

    Metallic engineered barriers must provide a period of absolute containment to high-level radioactive waste in geological repositories. Candidate materials include copper alloys, carbon steels, stainless steels, nickel alloys, and titanium alloys. The national programs of nuclear waste management have to identify and assess the anticipated degradation modes of the selected materials in the corresponding repository environment, which evolves in time. Commonly assessed degradation modes include general corrosion, localized corrosion, stress-corrosion cracking, hydrogen-assisted cracking, and microbiologically influenced corrosion. Laboratory testing and modeling in metallurgical and environmental conditions of similar and higher aggressiveness than those expected in service conditions are used to evaluate the corrosion resistance of the materials. This review focuses on the anticipated degradation modes of the selected or reference materials as corrosion-resistant barriers in nuclear repositories. These degradation modes depend not only on the selected alloy but also on the near-field environment. The evolution of the near-field environment varies for saturated and unsaturated repositories considering backfilled and unbackfilled conditions. In saturated repositories, localized corrosion and stress-corrosion cracking may occur in the initial aerobic stage, while general corrosion and hydrogen-assisted cracking are the main degradation modes in the anaerobic stage. Unsaturated repositories would provide an oxidizing environment during the entire repository lifetime. Microbiologically influenced corrosion may be avoided or minimized by selecting an appropriate backfill material. Radiation effects are negligible provided that a thick-walled container or an inner shielding container is used.

  14. Public reactions to nuclear waste: Citizens' views of repository siting

    International Nuclear Information System (INIS)

    Rosa, E.A.

    1993-01-01

    This book presents revised and updated papers from a panel of social scientists, at the 1989 AAAS meetings, that examined the public's reactions to nuclear waste disposal and the repository siting process. The papers report the results of original empirical research on citizens' views of nuclear waste repository siting. Topics covered include the following: content analysis of public testimony; sources of public concern about nuclear waste disposal in Texas agricultural communities; local attitudes toward high-level waste repository at Hanford; perceived risk and attitudes toward nuclear wastes; attitudes of Nevada urban residents toward a nuclear waste repository; attitudes of rural community residents toward a nuclear waste respository. An introductory chapter provides background and context, and a concluding chapter summarizes the implications of the reports. Two additional chapters cover important features of high-level waste disposal: long term trends in public attitudes toward nuclear energy and nuclear waste policy and assessment of the effects on the Los Vegas convention business if a high-level nuclear waste depository were sited in Nevada

  15. PRINCIPLE ROCK TYPES FOR RADIOACTIVE WASTE REPOSITORIES

    Directory of Open Access Journals (Sweden)

    Sibila Borojević Šostarić

    2012-07-01

    Full Text Available Underground geological storage of high- and intermediate/low radioactive waste is aimed to represent a barrier between the surface environment and potentially hazardous radioactive elements. Permeability, behavior against external stresses, chemical reacatibility and absorption are the key geological parameters for the geological storage of radioactive waste. Three principal rock types were discussed and applied to the Dinarides: (1 evaporites in general, (2 shale, and (3 crystalline basement rocks. (1 Within the Dinarides, evaporite formations are located within the central part of a Carbonate platform and are inappropriate for storage. Offshore evaporites are located within diapiric structures of the central and southern part of the Adriatic Sea and are covered by thick Mesozoic to Cenozoic clastic sediment. Under very specific circumstances they can be considered as potential site locations for further investigation for the storage of low/intermediate level radioactive wast e. (2 Thick flysch type formation of shale to phyllite rocks are exposed at the basement units of the Petrova and Trgovska gora regions whereas (3 crystalline magmatic to metamorphic basement is exposed at the Moslavačka Gora and Slavonian Mts. regions. For high-level radioactive waste, basement phyllites and granites may represent the only realistic potential option in the NW Dinarides.

  16. Study of nuclear waste storage capacity at Yucca mountain repository

    International Nuclear Information System (INIS)

    Zhou Wei; Apted, M.; Kessler, J.H.

    2008-01-01

    The Yucca Mountain repository is applying license for storing 70000 MTHM nuclear waste including commercial spent nuclear fuel (CSNF) and defense high-level radioactive waste (HLW). The 70000 MTHM is a legal not the technical limit. To study the technical limit, the Electric Power Research Institute (EPRI) carried out a systematic study to explore the potential impact if the repository will accept more waste. This paper describes the model and results for evaluating the spent-fuel disposal capacity for a repository at Yucca Mountain from the thermal and hydrological point of view. Two proposed alternative repository designs are analyzed, both of which would fit into the currently well-characterized site and, therefore, not necessitating any additional site characterization at Yucca Mountain. The two- and three-dimensional models for coupled thermo-hydrological analysis extends from the surface to the water table, covering all the major and subgroup rock layers of the planned repository, as well as formations above and below the repository horizon. A dual-porosity and dual-permeability approach is used to model coupled heat and mass transfer through fracture formations. The waste package heating and ventilation are all assumed to follow those of the current design. The results show that the repository is able to accommodate three times the amount of spent fuel compared to the current design, without extra spatial expansion or exceeding current thermal and hydrological constraints. (authors)

  17. Acceptability of a low and intermediate level radioactive waste repository

    International Nuclear Information System (INIS)

    Zeleznik, N.; Polic, M.

    2000-01-01

    Siting of a radioactive waste repository, even for the waste of low and intermediate level (LILW) radioactivity, presents a great problem in almost every country that produces such waste. The main problem is not a technical one, but socio-psychological, namely the acceptability of this kind of repository. In general, people are opposed to any such kind of facility in their vicinity (NIMBY). In this study we try to establish the factors that influence people's behavior regarding the construction of a radioactive waste repository in their local community, with the use of Ajzen's model of planned behavior. Two different scenarios about the construction of a radioactive waste repository in their community, together with a set of questions were presented to participants from different schools. Data from the survey were analysed by multivariate methods, and a model of relevant behaviour was proposed. From the results it can be seen that different approaches to local community participation in site selection process slightly influence people's attitudes towards the LILW repository, while significant differences in answers were found in the responses which depend on participants' knowledge. Therefore the RAO Agency will further intensify preparation of the relevant communication plan and start with its implementation to support LILW repository site selection process, which will also include educational programme. (author)

  18. On the Durability of Nuclear Waste Forms from the Perspective of Long-Term Geologic Repository Performance

    Directory of Open Access Journals (Sweden)

    Yifeng Wang

    2013-12-01

    Full Text Available High solid/water ratios and slow water percolation cause the water in a repository to quickly (on a repository time scale reach radionuclide solubility controlled by the equilibrium with alteration products; the total release of radionuclides then becomes insensitive to the dissolution rates of primary waste forms. It is therefore suggested that future waste form development be focused on conditioning waste forms or repository environments to minimize radionuclide solubility, rather than on marginally improving the durability of primary waste forms.

  19. Predicted thermal and stress environments in the vicinity of repository openings

    International Nuclear Information System (INIS)

    Bauer, S.J.; Hardy, M.P.; Lin, M.

    1991-01-01

    An understanding of the thermal and stress environment in the vicinity of repository openings is important for preclosure performance considerations and worker health and safety considerations for the proposed high-level radioactive waste repository at Yucca Mountain. This paper presents the results of two and three dimensional numerical analyses which have determined the thermal and stress environments for typical repository openings. In general, it is predicted that openings close to heat sources attain high temperatures and experience a significant stress increase. Openings away from heat sources experience more uniform temperature changes and experience a stress change which results in part from a far-field thermal loading

  20. Environmental impact assessments and geological repositories for radioactive waste

    International Nuclear Information System (INIS)

    O'Sullivan, P.; McKirdy, B.; Askarieh, M.; Bond, A.; Russell, S.

    1999-01-01

    Since 1985 it has been obligatory that facilities in the European Union designed for the permanent storage or disposal of radioactive waste be assessed to determine their effects on the environment. This assessment must be undertaken in advance of any decision by national authorities to give consent for development work to proceed. Member States are given wide discretion on how the above requirements are implemented in practice, e.g. the relevant European Council Directives call for the results of the environmental assessment to be made available to the public before development consent is granted but the detailed arrangements for dissemination of such information and procedures for public consultation are determined by individual Member States. Although the Directives require an assessment of the direct and indirect effects of a project on human beings and on various elements of the natural environment, they are non-specific as to what particular impacts should be addressed, particularly as regards the effects of a project on human beings. Therefore, for example, each Member State may decide whether or not social, health and economic impacts should be included in the assessment. This paper discusses the above issues. It proposes a model approach to environmental impact assessment in the context of geological repositories, including the role of the assessment on the overall decision processes for repository development, the scope and content of the assessment report, and approaches to public involvement

  1. Long-Term Safety Analysis of Baldone Radioactive Waste Repository and Updating of Waste Acceptance Criteria

    International Nuclear Information System (INIS)

    2001-12-01

    The main objective of the project was to provide advice to the Latvian authorities on the safety enhancements and waste acceptance criteria for near surface radioactive waste disposal facilities of the Baldone repository. The project included the following main activities: Analysis of the current status of the management of radioactive waste in Latvia in general and, at the Baldone repository in particular Development of the short and long-term safety analysis of the Baldone repository, including: the planned increasing of capacity for disposal and long term storage, the radiological analysis for the post-closure period Development of the Environment Impact Statement, for the new foreseen installations, considering the non radiological components Proposal of recommendations for future updating of radioactive waste acceptance criteria Proposal of recommendations for safety upgrades to the facility. The work programme has been developed in phases and main tasks as follows. Phase 0: Project inception, Phase 1: Establishment of current status, plans and practices (Legislation, regulation and standards, Radioactive waste management, Waste acceptance criteria), Phase 2: Development of future strategies for long-term safety management and recommendations for safety enhancements. The project team found the general approach use at the installation, the basic design and the operating practices appropriate to international standards. Nevertheless, a number of items subject to potential improvements were also identified. These upgrading recommendations deal with general aspects of the management (mainly storage versus disposal of long-lived sources), site and environmental surveillance, packaging (qualification of containers, waste characterization requirements), the design of an engineered cap and strategies for capping. (author)

  2. Public concerns and choices regarding nuclear-waste repositories

    International Nuclear Information System (INIS)

    Rankin, W.L.; Nealey, S.M.

    1981-06-01

    Survey research on nuclear power issues conducted in the late 1970's has determined that nuclear waste management is now considered to be one of the most important nuclear power issues both by the US public and by key leadership groups. The purpose of this research was to determine the importance placed on specific issues associated with high-level waste disposal. In addition, policy option choices were asked regarding the siting of both low-level and high-level nuclear waste repositories. A purposive sampling strategy was used to select six groups of respondents. Averaged across the six respondent groups, the leakage of liquid wastes from storage tanks was seen as the most important high-level waste issue. There was also general agreement that the issue regarding water entering the final repository and carrying radioactive wastes away was second in importance. Overall, the third most important issue was the corrosion of the metal containers used in the high-level waste repository. There was general agreement among groups that the fourth most important issue was reducing safety to cut costs. The fifth most important issue was radioactive waste transportation accidents. Overall, the issues ranked sixth and seventh were, respectively, workers' safety and earthquakes damaging the repository and releasing radioactivity. The eighth most important issue, overall, was regarding explosions in the repository from too much radioactivity, which is something that is not possible. There was general agreement across all six respondent groups that the two least important issues involved people accidentally digging into the site and the issue that the repository might cost too much and would therefore raise electricity bills. These data indicate that the concerns of nuclear waste technologists and other public groups do not always overlap

  3. Old waste products - new requirements. Preparations for the later repository

    International Nuclear Information System (INIS)

    Graf, A.; Merx, H.

    2003-01-01

    For more than 30 years now, the Hauptabteilung Dekontaminationsbetriebe (HDB, Central Decontamination Department) of the Forschungszentrum Karlsruhe has been engaged in the management of radioactive wastes produced by the operation and decommissioning of research reactors and institutes of the Research Center, the Karlsruhe reprocessing plant, the European Institute for Transuranium Elements, and the Baden-Wuerttemberg state collection center. For this purpose, the wastes delivered to HDB have been conditioned at various facilities according to the requirements specified. These conditioning requirements, however, have changed in the course of time. In the past, only minimum declaration and conditioning requirements had to be fulfilled for the ASSE repository storage facility. Since 1994, the KONRAD repository storage conditions have been adopted. They comprise a variety of quality criteria. Judging from today, duration of interim storage until transfer to a repository storage facility will take another 30 years at least. In addition to the documentary qualification of the waste products, it is therefore required to take measures to ensure long-term safety of both the waste packages and their storage. This is why the HDB, in agreement with the supervisory authority, i.e. the Federal Radiation Protection Authority, and its experts, has decided to put the waste products into KONRAD containers in certified compliance with the repository storage conditions and to backfill these containers with concrete in accordance with approved procedures. Thus, waste packages suited for repository storage will be produced and corrosion processes and the possible release of radioactivity will be prevented. (orig.)

  4. Old waste products - new requirements. Preparations for the later repository

    Energy Technology Data Exchange (ETDEWEB)

    Graf, A.; Merx, H. [Forschungszentrum Karlsruhe GmbH Technik und Umwelt (Germany). Hauptabteilung Dekontaminationsbetriebe

    2003-07-01

    For more than 30 years now, the Hauptabteilung Dekontaminationsbetriebe (HDB, Central Decontamination Department) of the Forschungszentrum Karlsruhe has been engaged in the management of radioactive wastes produced by the operation and decommissioning of research reactors and institutes of the Research Center, the Karlsruhe reprocessing plant, the European Institute for Transuranium Elements, and the Baden-Wuerttemberg state collection center. For this purpose, the wastes delivered to HDB have been conditioned at various facilities according to the requirements specified. These conditioning requirements, however, have changed in the course of time. In the past, only minimum declaration and conditioning requirements had to be fulfilled for the ASSE repository storage facility. Since 1994, the KONRAD repository storage conditions have been adopted. They comprise a variety of quality criteria. Judging from today, duration of interim storage until transfer to a repository storage facility will take another 30 years at least. In addition to the documentary qualification of the waste products, it is therefore required to take measures to ensure long-term safety of both the waste packages and their storage. This is why the HDB, in agreement with the supervisory authority, i.e. the Federal Radiation Protection Authority, and its experts, has decided to put the waste products into KONRAD containers in certified compliance with the repository storage conditions and to backfill these containers with concrete in accordance with approved procedures. Thus, waste packages suited for repository storage will be produced and corrosion processes and the possible release of radioactivity will be prevented. (orig.)

  5. Modeling transient heat transfer in nuclear waste repositories.

    Science.gov (United States)

    Yang, Shaw-Yang; Yeh, Hund-Der

    2009-09-30

    The heat of high-level nuclear waste may be generated and released from a canister at final disposal sites. The waste heat may affect the engineering properties of waste canisters, buffers, and backfill material in the emplacement tunnel and the host rock. This study addresses the problem of the heat generated from the waste canister and analyzes the heat distribution between the buffer and the host rock, which is considered as a radial two-layer heat flux problem. A conceptual model is first constructed for the heat conduction in a nuclear waste repository and then mathematical equations are formulated for modeling heat flow distribution at repository sites. The Laplace transforms are employed to develop a solution for the temperature distributions in the buffer and the host rock in the Laplace domain, which is numerically inverted to the time-domain solution using the modified Crump method. The transient temperature distributions for both the single- and multi-borehole cases are simulated in the hypothetical geological repositories of nuclear waste. The results show that the temperature distributions in the thermal field are significantly affected by the decay heat of the waste canister, the thermal properties of the buffer and the host rock, the disposal spacing, and the thickness of the host rock at a nuclear waste repository.

  6. Environmental issues of repository licensing: an evaluation of a hypothetical high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Owen, J.L.; McGinnis, J.T.; Harper, C.M.; Battelle Columbus Labs., OH)

    1982-01-01

    This paper presents results of an environmental assessment conducted under the direction of the Office of Nuclear Waste Isolation as part of the National Waste Terminal Storage program. The study defined a range of potential environmental effects of constructing, operating, decommissioning, and long-term isolation of a nuclear waste repository. The analytical methodology used to determine potential environmental effects required definition of a hypothetical environmental setting and repository. Potentially applicable regulatory requirements were identified and were used as guidelines to evaluate permitting feasibility. The environmental effects of repository development were analyzed for the two major time periods of concern: short term (the period of construction, operation, and decommissioning) and long term (the isolation period after decommissioning). As a result of this analysis, major environmental uncertainties and issues were identified. 11 references, 5 figures

  7. Deep repositories for waste central to uranium debate

    International Nuclear Information System (INIS)

    Kannegieter, T.

    1991-01-01

    While no deep repositories for high level wastes (HLW) have yet been constructed it is shown that technology to safely entomb the wastes for tens of thousands of years already exists. The borosilicate glass (vitrification) developed in France has been accepted by all countries who are reprocessing. Meanwhile, the Australian Synroc has not yet been put into service. Synroc developers at the Australian Nuclear Science and Technology Organization believe it will be the second generation waste form. The advantages and disadvantages of both technologies are briefly discussed as well as some of the regulatory, political, legal and technical conflicts surrounding the issue of HLW repositories. 1 tab., ills

  8. Formulating a low-alkalinity cement for radioactive waste repositories

    International Nuclear Information System (INIS)

    Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X.

    2004-01-01

    A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

  9. Formulating a low-alkalinity cement for radioactive waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Coumes, C. Cau Dit; Courtois, S.; Leclercq, S.; Bourbon, X

    2004-07-01

    A multi-annual research program has been launched in January 2003 by CEA, EDF and ANDRA in order to formulate and characterize low-alkalinity and low-heat cements which would be compatible with an underground waste repository environment. Four types of bindings have been investigated: binary blends of Portland cement and silica fume or metakaolin, as well as ternary blends of Portland cement, fly ash and silica fume or metakaolin. Promising results have been obtained with a mixture comprising 37.5% Portland cement, 32.5% silica fume, and 30% fly ash: pH of water in equilibrium with fully hydrated cement is below 11. Moreover, silica fume compensates for the low reactivity of fly ash, while fly ash allows to reduce water demand, heat release, and dimensional variations of cement pastes and mortars. (authors)

  10. Microbial Influence on the Performance of Subsurface, Salt-Based Radioactive Waste Repositories. An Evaluation Based on Microbial Ecology, Bioenergetics and Projected Repository Conditions

    International Nuclear Information System (INIS)

    Swanson, J.S.; Reed, D.T.; Cherkouk, A.; Arnold, T.; Meleshyn, A.; Patterson, Russ

    2018-01-01

    For the past several decades, the Nuclear Energy Agency Salt Club has been supporting and overseeing the characterisation of rock salt as a potential host rock for deep geological repositories. This extensive evaluation of deep geological settings is aimed at determining - through a multidisciplinary approach - whether specific sites are suitable for radioactive waste disposal. Studying the microbiology of granite, basalt, tuff, and clay formations in both Europe and the United States has been an important part of this investigation, and much has been learnt about the potential influence of microorganisms on repository performance, as well as about deep subsurface microbiology in general. Some uncertainty remains, however, around the effects of microorganisms on salt-based repository performance. Using available information on the microbial ecology of hyper-saline environments, the bioenergetics of survival under high ionic strength conditions and studies related to repository microbiology, this report summarises the potential role of microorganisms in salt-based radioactive waste repositories

  11. System analysis methods for geological repository of high level radioactive waste in granite

    International Nuclear Information System (INIS)

    Chen Weiming; Wang Ju; Li Yunfeng; Jin Yuanxin; Zhao Honggang

    2009-01-01

    Taking Beishan granite site as an example, this paper proposes the conceptual and structural design of repository for high level radioactive waste at first. Then the function, structure, environment and evolution of the repository are described by the methodology of system analysis. Based on these designs and descriptions, a calculation model for the repository is developed with software GoldSim. At last, this calculation model is applied to emulate the space-time distribution of repository radiotoxicity, to analyze the sensitivity of parameters in the model, to optimize the design parameters, and to predict and assess the repository performance. The results of this study can provide technical supports for resources allocation and coordination of R and D projects. (authors)

  12. Instrument reliability for high-level nuclear-waste-repository applications

    International Nuclear Information System (INIS)

    Rogue, F.; Binnall, E.P.; Armantrout, G.A.

    1983-01-01

    Reliable instrumentation will be needed to evaluate the characteristics of proposed high-level nuclear-wasted-repository sites and to monitor the performance of selected sites during the operational period and into repository closure. A study has been done to assess the reliability of instruments used in Department of Energy (DOE) waste repository related experiments and in other similar geological applications. The study included experiences with geotechnical, hydrological, geochemical, environmental, and radiological instrumentation and associated data acquisition equipment. Though this paper includes some findings on the reliability of instruments in each of these categories, the emphasis is on experiences with geotechnical instrumentation in hostile repository-type environments. We review the failure modes, rates, and mechanisms, along with manufacturers modifications and design changes to enhance and improve instrument performance; and include recommendations on areas where further improvements are needed

  13. Progress towards developing an international repository for radioactive waste

    International Nuclear Information System (INIS)

    Kurzeme, M.

    2001-01-01

    Pangea Resources was established to develop and promote the concept of international repositories. The concept was based on repositories located in geologically stable, flat, arid environments meeting the 'high isolation' criteria developed by Pangea Resources. The high isolation concept of Pangea Resources can be applied in various regions of the world, and these have been made public. The pilot project chosen for exploring feasibility was for an international repository in Australia. This study was in preparation for public release, when the existence of the proposal was prematurely revealed to the media. The general media and public reaction to the concept was understandably negative. However, there were also some opinion pieces reported suggesting that the concept of an international repository should be thought about seriously, before it is accepted or rejected. In addition, thoughtful reactions were received from the business and scientific communities. In particular a group of very eminent scientists, the Scientific Review Group, undertook to review independently the quality of the work done. Nevertheless, the reaction from the state and federal governments, was also negative. The Australian Government stated its policy not to permit importation or disposal of foreign nuclear waste. During the last two years Pangea Resources has been developing the technical aspects of the concept and has produced and published several scientific reports on transport, storage and disposal of radioactive materials. All the scientific studies of Pangea Resources have been reviewed by the Scientific Review Group. The work has also been presented in scientific conferences, to the media (including a dedicated television documentary) and to the public. The technical work is generic or is based on diverse potential siting areas around the world and the disposal and storage technologies studied are being broadened beyond the specific high-isolation concept. Most importantly, it has

  14. Reference waste package environment report

    International Nuclear Information System (INIS)

    Glassley, W.E.

    1986-01-01

    One of three candidate repository sites for high-level radioactive waste packages is located at Yucca Mountain, Nevada, in rhyolitic tuff 700 to 1400 ft above the static water table. Calculations indicate that the package environment will experience a maximum temperature of ∼230 0 C at 9 years after emplacement. For the next 300 years the rock within 1 m of the waste packages will remain dehydrated. Preliminary results suggest that the waste package radiation field will have very little effect on the mechanical properties of the rock. Radiolysis products will have a negligible effect on the rock even after rehydration. Unfractured specimens of repository rock show no change in hydrologic characteristics during repeated dehydration-rehydration cycles. Fractured samples with initially high permeabilities show a striking permeability decrease during dehydration-rehydration cycling, which may be due to fracture healing via deposition of silica. Rock-water interaction studies demonstrate low and benign levels of anions and most cations. The development of sorptive secondary phases such as zeolites and clays suggests that anticipated rock-water interaction may produce beneficial changes in the package environment

  15. Repository-analog experiments of nuclear waste leaching and migration

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1982-01-01

    The potential for radionuclide migration from a breached nuclear-waste repository depends on the leaching and subsequent interaction of the leached radionuclides with materials in the groundwater flow path. An attempt is made to consider all interactions using experiments that integrate repository materials. Results of a repository-analog experiment using borosilicate glass, fissured granite, and flowing water suggest: (1) plutonium was immobile possibly because of its low solubility; (2) caesium migrated down slowly because of sorption; and (3) neptunium remained oxidized even in water of low oxidation potential. By summing the effects of all interactions, not just sorption, the repository-analog experiment produced radionuclide migration that could be expected from a breached repository. (author)

  16. Radiosensitivity of microorganisms isolated from radioactive waste repository

    International Nuclear Information System (INIS)

    Gazso, Lajos

    2001-01-01

    Bacteria are much more diverse in comparison with plants and animals. Among the huge diversity of bacteria there are microorganisms capable to grow at or adapt to extreme conditions. Some bacteria grow at temperature above 100 deg. C, other thrive in high salinity such as 20-30% NaCl, still others can live at pH lower than 2 or pH higher than 10 or exhibit high radioresistance. Due to accelerated disarmament and nuclear energy activities, large quantities of radioactive waste and nuclear fuel are being placed in storage areas. The awareness the microbial activity could potentially effect the performance of a system for geological disposal of radioactive waste gained acceptance in the early to middle 1980s, and as a result many countries considering developing programmes to study and quantify microbial effects in terms of their own particular disposal concept. A new research programme was launched in 1995, sponsored by the NATO Scientific Affairs Division, for studying microbiologically influenced corrosion (MIC) in radioactive waste repositories and spent fuel storage area. Our programme concerns several major items that may have an influence on the mobility of radionuclides in direct and indirect ways thereby being important for the safety analysis. They are uptake and transport of radionuclides by microorganisms, diversity and distribution of subterranean bacteria in typical repository environments, environmental limitation and bacterial activity, effect of bacterial activity on the mobility of radionuclides, microbial gas production and consumption, bacterial recombination of hydrogen and oxygen from radiolysis, and microbially induced corrosion of waste canister. The Permian Boda Claystone Formation in the Mecsek Hill area is being considered for high level waste disposal. Groundwater, technical water, rock and surface samples were collected aseptically from different depths. The quantitative and qualitative analysis of aerobic and anaerobe isolates were

  17. Optimization method for dimensioning a geological HLW waste repository

    International Nuclear Information System (INIS)

    Ouvrier, N.; Chaudon, L.; Malherbe, L.

    1990-01-01

    This method was developed by the CEA to optimize the dimensions of a geological repository by taking account of technical and economic parameters. It involves optimizing radioactive waste storage conditions on the basis of economic criteria with allowance for specified thermal constraints. The results are intended to identify trends and guide the choice from among available options: simple and highly flexible models were therefore used in this study, and only nearfield thermal constraints were taken into consideration. Because of the present uncertainty on the physicochemical properties of the repository environment and on the unit cost figures, this study focused on developing a suitable method rather than on obtaining definitive results. The optimum values found for the two media investigated (granite and salt) show that it is advisable to minimize the interim storage time, implying the containers must be separated by buffer material, whereas vertical spacing may not be required after a 30-year interim storage period. Moreover, the boreholes should be as deep as possible, on a close pitch in widely spaced handling drifts. These results depend to a considerable extent on the assumption of high interim storage costs

  18. Engineering materials for high level radioactive waste repository

    International Nuclear Information System (INIS)

    Wen Zhijian

    2009-01-01

    Radioactive wastes can arise from a wide range of human activities and have different physical and chemical forms with various radioactivity. The high level radioactive wastes (HLW)are characterized by nuclides of very high initial radioactivity, large thermal emissivity and the long life-term. The HLW disposal is highly concerned by the scientists and the public in the world. At present, the deep geological disposal is regarded as the most reasonable and effective way to safely dispose high-level radioactive wastes in the world. The conceptual model of HLW geological disposal in China is based on a multi-barrier system that combines an isolating geological environment with an engineering barrier system(EBS). The engineering materials in EBS include the vitrified HLW, canister, overpack, buffer materials and backfill materials. Referring to progress in the world, this paper presents the function, the requirement for material selection and design, and main scientific projects of R and D of engineering materials in HLW repository. (authors)

  19. Stream-simulation experiments for waste-repository investigations

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1980-01-01

    The potential for radionuclide migration by groundwater flow from a breached-water repository depends on the leaching process and on chemical changes that might occur as the radionuclide moves away from the repository. Therefore, migration involves the interactions of leached species with (1) the waste and canister, (2) the engineered barrier, and (3) the geologic materials surrounding the repository. Rather than attempt to synthesize each species and study it individually, another approach is to integrate all species and interactions using stream-simulation experiments. Interactions identified in these studies can then be investigated in detail in simpler experiments

  20. Global nuclear waste repository proposal highlights Australia's nuclear energy vacuum

    International Nuclear Information System (INIS)

    Anon.

    1999-01-01

    The Pangea proposal is disscused and considered relevant to Australia. A five-year research program by the company has identified Australia and Argentina as having the appropriate geological, economic and democratic credentials for such a deep repository, with Australia being favoured. A deep repository would be located where the geology has been stable for several hundred million years, so that there need not be total reliance on a robust engineered barrier system to keep the waste securely isolated for thousands of years. It would be a commercial undertaking and would have dedicated port and rail infrastructure. It would take spent fuel and other wastes from commercial reactors, and possibly also waste from weapons disposal programs. Clearly, while the primary ethical and legal principle is that each country is entirely responsible for its own waste, including nuclear waste (polluter pays etc), the big question is whether the concept of an international waste repository is acceptable ethically. Political and economic questions are secondary to this. By taking a fresh look at the reasons for the difficulties which have faced most national repository programs, and discarding the preconception that each country must develop its own disposal facilities, it is possible to define a class of simple, superior high isolation sites which may provide a multi-national basis for solving the nuclear waste disposal problem. The relatively small volumes of high-level wastes or spent fuel which arise from nuclear power production make shared repositories a feasible proposition. For small countries, the economies of scale which can be achieved make the concept attractive. For all countries, objective consideration of the relative merits of national and multi-national solutions is a prudent part of planning the management of long-lived radioactive wastes

  1. Nuclear safety requirements for upgrading the National Repository for Radioactive Wastes-Baita Bihor

    International Nuclear Information System (INIS)

    Vladescu, Gabriela; Necula, Daniela

    2000-01-01

    The upgrading project of National Repository for Radioactive Wastes-Baita Bihor is based on the integrated concept of nuclear safety. Its ingredients are the following: A. The principles of nuclear safety regarding the management of radioactive wastes and radioprotection; B. Safety objectives for final disposal of low- and intermediate-level radioactive wastes; C. Safety criteria for final disposal of low- and intermediate-level radioactive wastes; D. Assessment of safety criteria fulfillment for final disposal of low- and intermediate-level radioactive wastes. Concerning the nuclear safety in radioactive waste management the following issues are considered: population health protection, preventing transfrontier contamination, future generation radiation protection, national legislation, control of radioactive waste production, interplay between radioactive waste production and management, radioactive waste repository safety. The safety criteria of final disposal of low- and intermediate-level radioactive wastes are discussed by taking into account the geological and hydrogeological configuration, the physico-chemical and geochemical characteristics, the tectonics and seismicity conditions, extreme climatic potential events at the mine location. Concerning the requirements upon the repository, the following aspects are analyzed: the impact on environment, the safety system reliability, the criticality control, the filling composition to prevent radioactive leakage, the repository final sealing, the surveillance. Concerning the radioactive waste, specific criteria taken into account are the radionuclide content, the chemical composition and stability, waste material endurance to heat and radiation. The waste packaging criteria discussed are the mechanical endurance, materials toughness and types as related to deterioration caused by handling, transportation, storing or accidents. Fulfillment of safety criteria is assessed by scenarios analyses and analyses of

  2. Preliminary waste acceptance requirements for the planned Konrad repository

    International Nuclear Information System (INIS)

    Warnecke, E.; Brennecke, P.

    1987-01-01

    The Physikalisch-Technische Bundesanstalt (PTB) has established Preliminary Waste Acceptance Requirements for the planned Konrad repository. These requirements were developed, in accordance with the Safety Criteria of the Reactor Safety Commission, with the help of a site specific safety assessment; they are under the reservation of the plan approval procedure, which is still in progress. In developing waste acceptance requirements, the PTB fulfills one of its duties as the institute responsible for waste disposal and gives guidelines for waste conditioning to waste producers and conditioners. (orig.) [de

  3. Material control and accountability procedures for a waste isolation repository

    International Nuclear Information System (INIS)

    Jenkins, J.D.; Allen, E.J.; Blakeman, E.D.

    1978-05-01

    The material control and accountability needs of a waste isolation repository are examined. Three levels of control are discussed: (1) item identification and control, (2) tamper indication, and (3) quantitative material assay. A summary of waste characteristics is presented and, based on these, plus a consideration of the accessibility of the various types of waste, material control by item identification and accountability (where the individual waste container is the basic unit) is recommended. Tamper indicating procedures are also recommended for the intermediate and low level waste categories

  4. Building on existing institutions to perpetuate knowledge of waste repositories

    International Nuclear Information System (INIS)

    Weitzberg, A.

    1982-08-01

    Purpose of this report is to examine the function of several existing institutions and to show how they could be effectively used to transmit information about waste repositories for long times into the future. Scope of this report is limited to a discussion of four institutional approaches to the dissemination and retention of information: Widely distributed maps, the marker system of the National Geodetic Survey, the archiving of documents, and one-call systems designed to protect underground utility installations from inadvertent damage by the public. Each of these approaches is discussed in an independent section that describes the background of the institutional approach, discusses methods for applying it to waste repositories, and assesses its potential value. The sole intent of this report is to present supporting data for future decisions about the kinds of communication measures that should be implemented to advise future generations about the locations and hazards of waste repositories

  5. The Pangea concept for an international radioactive waste repository

    International Nuclear Information System (INIS)

    Kurzeme, M.

    1999-01-01

    Pangea Resources Australia Pty. Ltd. is engaged in a study to investigate the feasibility of constructing and operating an international radioactive waste repository in Australia. Western Australia in particular has a unique combination of geology, topography and climate which makes it eminently suitable for a deep geological repository for the safe and permanent disposal of radioactive waste. Australia also has the political, social, legal and financial systems, together with the technical capability to make it acceptable as a host nation for an international repository. This paper reviews the origins of the Pangea concept, describes the high isolation approach to site selection, the Pangea integrated waste management system, together with its potential economic impact on Australia

  6. Geographical information system (GIS) suitability analysis of radioactive waste repository site in Pahang, Malaysia

    International Nuclear Information System (INIS)

    Faizal Azrin Abd Razalim; Noraini Surip; Ahmad Hasnulhadi; Nazran Harun; Nurul Nadia Abd Malek; Roziah Che Musa

    2010-01-01

    The aim of this project is to identify a suitable site for radioactive waste repository in Pahang using remote sensing and geographical information system (GIS) technologies. There are ten parameters considered in the analysis, which divided into Selection Criteria and Exclusion Criteria. The Selection Criteria parameters consists of land use, rainfall, lineament, slope, groundwater potential and elevation while Exclusion Criteria parameters consist of urban, protected land and island. Furthermore, all parameters were integrated, given weight age and ranked for site selection evaluation in GIS environment. At the first place, about twelve sites have been identified as suitable sites for radioactive waste repository throughout the study area. These sites were further analysed by ground checking on the physical setting including geological, drainage, and population density in order to finalise three most suitable sites for radioactive waste repository. (author)

  7. Fuzzy distributions in probabilistic environmental impact assessment: application to a high-level waste repository

    International Nuclear Information System (INIS)

    Datta, D.; Joshi, M.L.

    2006-01-01

    Environmental modeling with a satisfaction levels of the end user in relation to a defined parameter coupled with imprecision that stems from the field data is a key issue. In the context of this issue success of possibility theory based on fuzzy sets has high visibility in comparison with conventional probability theory. Environmental impact assessments of a high level waste repository is focused using the new approach because the problems under consideration includes a number of qualitative uncertainties at different levels, apart from being quite complex; decision-maker's need to have a transparent assessment result that will enable him to understand underlying assumptions and to judge resulting doses. Fuzzy distributions have been tried to resolve the issues related to the safety of environment from the waste repository. Paper describes the details of fuzzy distribution, fuzzy logic and its possible application to deal the qualitative and quantitative uncertainty in connection with waste repository. (author)

  8. Developing of Radioactive Wastes Management Safety at Baldone Repository Radons

    International Nuclear Information System (INIS)

    Abramenkovs, A.; Abramenkova, G.; Klavins, M.

    2008-01-01

    The near surface radioactive wastes repository Radons near the Baldone city was put in operation in 1962. The safety assessment of repository was performed during 2000-2001 under the PHARE project to evaluate the recommended upgrades of repository. The outline design for new vaults and interim storage for long lived radioactive wastes was elaborated during 2003-2004 years. The Environmental Impact Assessment (EIA) for upgrade of Baldone repository was performed during 2004-2005 years. Additional evaluations of radioactive wastes management safety were performed during 2006 year by the experts of ENRESA, Spain. It was shown, that the additional efforts were spent for improving of radioactive wastes cementation in concrete containers. The results of tritium and Cs 137 leaching studies are presented and discussed. It was shown, that additives can significantly reduce the migration of radionuclides in ground water. The leaching coefficients for tritium and Cs 137 were determined to supply with the necessary data the risk assessment calculations for operation of Baldone repository R adons

  9. Ventilation planning for a prospective nuclear waste repository

    International Nuclear Information System (INIS)

    Wallace, K.G. Jr.

    1987-01-01

    In 1982, the US Congress passed the Nuclear Waste Policy Act to provide for the development of underground repositories for spent nuclear fuel. This development will be managed by the United States Department of Energy. In 1986, the President selected three areas for site characterization to determine their suitability for the development of an underground repository; those sites were: (1) A site in volcanic tuff located at Yucca Mountain in Nevada, (2) a site in bedded salt located in Deaf Smith County in Texas, and (3) a site in basalt located in Hanford, Washington. At present conceptual repository designs are being developed for each site. A key element of a repository design is the underground ventilation system required to support construction, nuclear waste emplacement, and potential waste retrieval. This paper describes the preliminary ventilation systems designed for the repository in tuff. The concept provides separate ventilation systems for the construction and waste emplacement activities. The paper further describes the means by which acceptable environmental conditions will be re-established to allow re-entry into previously closed rooms for the purpose of inspection, maintenance or retrieval

  10. Nuclear waste in a repository: amount as a factor in risk duration

    International Nuclear Information System (INIS)

    Zen, E.

    1980-01-01

    The relationship between the amount of nuclear waste in a nuclear repository and the safety of the repository is examined. It is shown that the amount of a given hazardous nuclide that is potentially leachable depends on the initial amount of waste in the repository and the time that has elapsed since the repository was put into operation. Nuclear repository safety can be enhanced if repositories are designed as modular units with leach-resistant watertight compartments

  11. Expected brine movement at potential nuclear waste repository salt sites

    International Nuclear Information System (INIS)

    McCauley, V.S.; Raines, G.E.

    1987-08-01

    The BRINEMIG brine migration code predicts rates and quantities of brine migration to a waste package emplaced in a high-level nuclear waste repository in salt. The BRINEMIG code is an explicit time-marching finite-difference code that solves a mass balance equation and uses the Jenks equation to predict velocities of brine migration. Predictions were made for the seven potentially acceptable salt sites under consideration as locations for the first US high-level nuclear waste repository. Predicted total quantities of accumulated brine were on the order of 1 m 3 brine per waste package or less. Less brine accumulation is expected at domal salt sites because of the lower initial moisture contents relative to bedded salt sites. Less total accumulation of brine is predicted for spent fuel than for commercial high-level waste because of the lower temperatures generated by spent fuel. 11 refs., 36 figs., 29 tabs

  12. Radioactive Waste Repositories and Incentives to Local Communities

    International Nuclear Information System (INIS)

    Knapp, A.; Medakovic, S.

    2008-01-01

    Public acceptance of radioactive waste (RW) repository depends on various and often community-specific factors. Although radiological risk from a properly constructed low and intermediate level waste (LILW) repository is practically negligible, routine safety considerations will favor low populated areas and therefore probably underdeveloped communities. Repository acceptance in such communities is more likely to be facilitated by prospective benefits to local economy, such as infrastructure development and increased employment, as well as by dedicated financial incentives to the community. Direct financial compensation to the local community for acceptance of the repository has been considered in some documents in countries experienced in RW management, but it has not become a widely accepted practice. In Croatia, a possibility for such compensation is mentioned in the land use plan in conjunction with the prospective RW repository site. In Slovenia, the government has already specified the annual amount of 2.33 million euro as a compensation for 'limited land use' to be shared by local communities in the vicinity of the planned LILW repository during its operation. Applicability of the Slovenian compensations to the prospective joint Slovenian-Croatian repository is not yet clear, at least in the aspect of joint funding. The joint Slovenian-Croatian Decommissioning and LILW and SF management program for NPP Krsko from 2004 did conservatively include the compensations into the repository cost estimates, but that might not be retained in subsequent revisions of the Program. According to the agreement between governments of Slovenia and Croatia on the Nuclear power plant Krsko, Croatian side has no obligations to participate in 'public expenditures' introduced after the agreement, as would be the case of community compensations for LILW repository in Slovenia. Before further decisions on joint NPP Krsko waste management are made, including the issue of LILW

  13. Buoyancy flow in fractures intersecting a nuclear waste repository

    International Nuclear Information System (INIS)

    Wang, J.S.Y.; Tsang, C.F.

    1980-07-01

    The thermally induced buoyancy flow in fractured rocks around a nuclear waste repository is of major concern in the evaluation of the regional, long-term impact of nuclear waste disposal in geological formation. In this study, buoyancy flow and the development of convective cells are calculated in vertical fractures passing through or positioned near a repository. Interaction between buoyancy flow and regional hydraulic gradient is studied as a function of time, and the interference of intersecting fractures with each other is also discussed

  14. Radioactive waste transport to a Nirex deep repository

    International Nuclear Information System (INIS)

    Bennett, D.; Appleton, P.R.; Eastman, C.R.

    1989-01-01

    Nirex is addressing the transport of radioactive wastes, repository construction materials, personnel and spoil as part of their development of a deep repository. An integrated transport system will be developed for wastes which may involve, road, rail and sea transport. The possible application and the scale of operation of the transport system is described. Environmental impact assessments will be carried out, and the proposed approach to these is described. A methodology for the assessment of transport safety has been established and the results of a preliminary assessment are given. (author)

  15. The design of the Bulgaria rad waste repository

    International Nuclear Information System (INIS)

    Stefonova, I.; Petrov, I.; Navarro, M.; Sanchez, M.; Medinilla, G.

    2012-01-01

    In October 2011 a consortium composed by Westinghouse Engineering Spain SAU, ENRESA and DBE Technology GmbH was awarded a contract for the design of the Bulgaria rad waste repository. The facility, inspired in the spanish centre of El Cabril owned by ENRESA, will consist of a 66 reinforced concrete cells surface repository capable of receiving 18600 already conditioned waste containers of 20 t each, during 60 years, and the related auxiliary facilities and buildings. The project, representing a challenge because of the schedule and required level of detail, goes on fulfilling main milestones and getting customer satisfaction. (Author)

  16. Low and intermediate level waste repositories: public involvement aspects

    International Nuclear Information System (INIS)

    Ferreira, Vinicius V.M.; Mourao, Rogerio P.; Fleming, Peter M.; Soares, Wellington A.; Braga, Leticia T.P.; Santos, Rosana A.M.

    2009-01-01

    The nuclear energy acceptance creates several problems, and one of the most important is the disposal of the radioactive waste. International experiences show that not only environmental, radiological and technical questions have to be analyzed, but the public opinion about the project must be considered. The objective of this article is to summarize some public involvement aspects associated with low and intermediate level waste repositories. Experiences from USA, Canada, South Africa, Ukraine and other countries are studied and show the importance of the population in the site selection process for a repository. (author)

  17. Mathematical modelling of heat production in deep geological repository of high-level nuclear waste

    International Nuclear Information System (INIS)

    Kovanda, O.

    2017-01-01

    Waste produced by nuclear industry requires special handling. Currently, there is a research taking place, focused at possibilities of nuclear waste storage in deep geological repositories, hosted in stable geological environment. The high-level nuclear waste produces significant amount of heat for a long time, which can affect either environment outside of or within the repository in a negative way. Therefore to reduce risks, it is desirable to know the principles of such heat production, which can be achieved using mathematical modeling. This thesis comes up with a general model of heat production-time dependency, dependable on initial composition of the waste. To be able to model real situations, output of this thesis needs to be utilized in an IT solution. (authors)

  18. Multi criteria decision analysis on a waste repository in Mol

    International Nuclear Information System (INIS)

    Carle, B.

    2005-01-01

    In Belgium, the management of radioactive waste is taken care of by ONDRAF/NIRAS, the Belgian Agency for Radioactive Waste and Enriched Fissile Materials. Local partnerships with stakeholders from municipalities in existing nuclear zones were setup to facilitate the dialogue between the repository designers and the local community. Since the establishment of the partnership in Mol, MONA in February 2000, all aspects of a possible near-surface or a deep geological repository are discussed in 4 working groups by around 50 volunteer members. The outcome of the discussions in the partnership can be a shared project, supported by both local stakeholders and ONDRAF/NIRAS, in which the specifications and the conditions needed for establishing a repository in Mol are elaborated. MONA asked the Decision Strategy Research Department of SCK-CEN to organise a Multi Criteria Analysis (MCA) in the context of the deciding between a surface and a deep repository for low level radioactive waste. The objective of the multi criteria analysis is to support a number of representatives of the various working groups within MONA in their selection between two acceptable options for a repository of low level radioactive waste on the territory of Mol. The options are the surface repository developed by the working groups of MONA, and a deep repository in the clay layers underneath the nuclear site of Mol. This study should facilitate the selection between both options, or in case this appears to be difficult, at least to get a well-structured overview of all factors (criteria) of importance to the judgement, and to get insight into the degree in which the various criteria contribute to the selection

  19. Nuclear waste repository in basalt: a design description

    International Nuclear Information System (INIS)

    Ritchie, J.S.; Schmidt, B.

    1982-01-01

    The conceptual design of a nuclear waste repository in basalt is described. Nuclear waste packages are placed in holes drilled into the floor of tunnels at a depth of 3700 ft. About 100 miles of tunnels are required to receive 35,000 packages. Five shafts bring waste packages, ventilation air, excavated rock, personnel, material, and services to and from the subsurface. The most important surface facility is the waste handling building, located over the waste handling shaft, where waste is received and packaged for storage. Two independent ventilation systems are provided to avoid potential contamination of spaces that do not contain nuclear waste. Because of the high temperatures at depth, an elaborate air chilling system is provided. Because the waste packages deliver a considerable amount of heat energy to the rock mass, particular attention is paid to heat transfer and thermal stress studies. 3 references, 31 figures, 3 tables

  20. Potential host media for a high-level waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Hustrulid, W

    1982-01-01

    Earlier studies of burial of radioactive wastes in geologic repositories had concentrated on salt formations for well-publicized reasons. However, under the Carter administration, significant changes were made in the US nuclear waste management program. Changes which were made were: (1) expansion of the number of rock types under consideration; (2) adoption of the multiple-barrier approach to waste containment; (3) additional requirements for waste retrieval; and (4) new criteria proposed by the Nuclear Regulatory Commission for the isolation of high-level waste in geologic repositories. Results of the studies of different types of rocks as repository sites are summarized herein. It is concluded that each generic rock type has certain advantages and disadvantages when considered from various aspects of the waste disposal problem and that characteristics of rocks are so varied that a most favorable or least favorable rock type cannot be easily identified. This lack of definitive characteristics of rocks makes site selection and good engineering barriers very important for containment of the wastes. (BLM)

  1. Implications of one-year basalt weathering/reactivity study for a basalt repository environment

    International Nuclear Information System (INIS)

    Pine, G.L.; Jantzen, C.M.

    1987-03-01

    The Savannah River Laboratory is testing the performance of the Defense Waste Processing Facility glass under conditions representing potential repository environments. For a basalt repository, one of the important issues is how rapidly reducing conditions are re-established after placement of the waste. The objective of this study was to examine the factors affecting the reactivity of the basalt. Construction of a nuclear waste repository in basalt will temporarily perturb the groundwater conditions, creating more oxidizing (air-saturated) conditions than an undisturbed repository system. Reducing conditions can be beneficial to the performance of waste glass and canisters, and may limit the transport of certain radionuclides. The Basalt Waste Isolation Project intends to use a backfill containing crushed basalt to re-establish the reducing conditions of the groundwater. The reactivity of the basalt has been found to be minimal once the fresh crushed surfaces have been weathered and the reactive intergranular glass component has been leached, e.g., by long-term surface storage. Crushing of the basalt for pneumatic emplacement of the backfill should, therefore, occur shortly before placement in the repository. This backfill must contain a minimum of 5 percent reactive fines (<100 mesh), to rapidly achieve reducing conditions. 23 refs., 21 figs., 18 tabs

  2. Assessing microbiologically induced corrosion of waste package materials in the Yucca Mountain repository

    Energy Technology Data Exchange (ETDEWEB)

    Horn, J. M., LLNL

    1998-01-01

    The contribution of bacterial activities to corrosion of nuclear waste package materials must be determined to predict the adequacy of containment for a potential nuclear waste repository at Yucca Mountain (YM), NV. The program to evaluate potential microbially induced corrosion (MIC) of candidate waste container materials includes characterization of bacteria in the post-construction YM environment, determination of their required growth conditions and growth rates, quantitative assessment of the biochemical contribution to metal corrosion, and evaluation of overall MIC rates on candidate waste package materials.

  3. Rock mechanics for hard rock nuclear waste repositories

    International Nuclear Information System (INIS)

    Heuze, F.E.

    1981-09-01

    The mined geologic burial of high level nuclear waste is now the favored option for disposal. The US National Waste Terminal Storage Program designed to achieve this disposal includes an extensive rock mechanics component related to the design of the wastes repositories. The plan currently considers five candidate rock types. This paper deals with the three hard rocks among them: basalt, granite, and tuff. Their behavior is governed by geological discontinuities. Salt and shale, which exhibit behavior closer to that of a continuum, are not considered here. This paper discusses both the generic rock mechanics R and D, which are required for repository design, as well as examples of projects related to hard rock waste storage. The examples include programs in basalt (Hanford/Washington), in granitic rocks (Climax/Nevada Test Site, Idaho Springs/Colorado, Pinawa/Canada, Oracle/Arizona, and Stripa/Sweden), and in tuff

  4. Reliable predictions of waste performance in a geologic repository

    International Nuclear Information System (INIS)

    Pigford, T.H.; Chambre, P.L.

    1985-08-01

    Establishing reliable estimates of long-term performance of a waste repository requires emphasis upon valid theories to predict performance. Predicting rates that radionuclides are released from waste packages cannot rest upon empirical extrapolations of laboratory leach data. Reliable predictions can be based on simple bounding theoretical models, such as solubility-limited bulk-flow, if the assumed parameters are reliably known or defensibly conservative. Wherever possible, performance analysis should proceed beyond simple bounding calculations to obtain more realistic - and usually more favorable - estimates of expected performance. Desire for greater realism must be balanced against increasing uncertainties in prediction and loss of reliability. Theoretical predictions of release rate based on mass-transfer analysis are bounding and the theory can be verified. Postulated repository analogues to simulate laboratory leach experiments introduce arbitrary and fictitious repository parameters and are shown not to agree with well-established theory. 34 refs., 3 figs., 2 tabs

  5. Safety analysis of the proposed Canadian geologic nuclear waste repository

    International Nuclear Information System (INIS)

    Prowse, D.R.

    1977-01-01

    The Canadian program for development and qualification of a geologic repository for emplacement of high-level and long-lived, alpha-emitting waste from irradiated nuclear fuel has been inititiated and is in its initial development stage. Fieldwork programs to locate candidate sites with suitable geological characteristics have begun. Laboratory studies and development of models for use in safety analysis of the emplaced nuclear waste have been initiated. The immediate objective is to complete a simplified safety analysis of a model geologic repository by mid-1978. This analysis will be progressively updated and will form part of an environmental Assessment Report of a Model Fuel Center which will be issued in mid-1979. The long-term objectives are to develop advanced safety assessment models of a geologic repository which will be available by 1980

  6. Basic repository environment assessment design basis, Cypress Creek Dome Site

    International Nuclear Information System (INIS)

    1988-03-01

    This study examines the engineering factors and costs associated with the construction, operation, and decommissioning of a high-level nuclear waste repository in salt in the Gulf Interior Region at Cypress Creek Cone, Mississippi. The study assumes a repository capacity of 36,000 metric tons of heavy metal (MTHM) of unreprocessed spent fuel and 36,000 MTHM of commercial high-level reprocessing waste, along with 7020 canisters of defense high-level reprocessing waste and associated quantities of remote- and contact-handled transuranic waste (TRU). With the exception of TRU, all the waste forms are placed in 300- to 1000-year-life carbon-steel waste packages in a collocated waste handling and packaging facility (WHPF), which is also described. The construction, operation, and decommissioning of the proposed repository is estimated to cost approximately $4.66 billion. Costs include those for the collocated WHPF, engineering, and contingency, but exclude waste from assembly and shipment to the site and waste package fabrication and shipment to the site. These costs reflect the relatively easy access to the site. Construction would require an estimated 7 years. Engineering factors and costs are not strongly influenced by environmental considerations. 53 refs., 24 figs., 10 tabs

  7. Model of evolution of radioactive waste repositories and their influence on the resource-ecological safety of an adjoining territories

    International Nuclear Information System (INIS)

    Angelova, R.; Sandul, G.A.; Sen'ko, T.Ya.

    2002-01-01

    In this paper it is considered the mathematical model of evolution of radioactive waste (RAW) repositories and their influence on the resource-ecological safety (RES) and sustainable development of an adjoining territories. Heart of considered model consists of that RAW repository is considered as a system with two processes proceeding in parallel: deterioration of repository buildings, equipment etc. enlarging resource-ecological danger (RED) on account of probability increase (risk increase) of emergency conditions; natural decay of RAW being in repository that lead to RED decrease. Considered model allows to learn RAW repositories evolution in given time interval and to analyze their behavior at its different stages depending on state of repositories, e.g., their modernization or other events as well as to define periods of RAW repositories peak danger for environment

  8. Site suitability criteria for solidified high level waste repositories

    International Nuclear Information System (INIS)

    Heckman, R.A.; Holdsworth, T.; Towse, D.F.

    1979-01-01

    Activities devoted to development of regulations, criteria, and standards for storage of solidified high-level radioactive wastes are reported. The work is summarized in sections on site suitability regulations, risk calculations, geological models, aquifer models, human usage model, climatology model, and repository characteristics. Proposed additional analytical work is also summarized

  9. Conflict, location, and politics: Siting a nuclear waste repository

    International Nuclear Information System (INIS)

    Jacob, G.R.

    1988-01-01

    Nuclear power and the management of high-level radioactive waste is examined with the goal of explaining the forces driving the formulation of the 1982 Nuclear Waste Policy Act and a subsequent decision to site a nuclear waste repository at Yucca Mountain, Nevada. The study draws upon geographic, political, economic, and organizational factors to examine the commitment to dispose of spent fuel in a geologic repository located in Nevada or in Utah, Texas, Mississippi, Louisiana, or at Hanford Washington. Special attention is given to the impact of location, science and technology on the definition of the nuclear waste problem and political agendas, public participation, and the power of the nuclear establishment. The study finds that the choice of a Yucca Mountain Nevada as the preferred site for a repository was based more on technological precedent and political-economic expediency than on the demonstrated superiority of that site's geology. Conflict over a repository location is interpreted as a symptom of more fundamental conflicts concerning: the credibility of nuclear science, the legitimacy of federal authority and administration, and the priorities of environmental protection and a nuclear economy

  10. Models and criteria for waste repository performance

    International Nuclear Information System (INIS)

    Smith, C.F.; Cohen, J.J.

    1981-03-01

    A primary objective of the Waste Management Program is to assure that public health is protected. Predictive modeling, to some extent, will play a role in assuring that this objective is met. This paper considers the requirements and limitations of predictive modeling in providing useful inputs to waste management decision making. Criteria development needs and the relation between criteria and models are also discussed

  11. Sealing a nuclear waste repository in Columbia river basalt: preliminary results

    International Nuclear Information System (INIS)

    Hodges, F.N.

    1980-01-01

    The long containment time required of repositories for nuclear waste (10 4 to 10 6 years) requires that materials used for repository seals be stable in the geologic environment of the repository and of proven longevity. A list of candidate materials for sealing a repository in Columbia River Basalts has been prepared and refined through laboratory testing. The most feasible techniques for emplacing preferred plug materials have been identified and the resultant plugs have been evaluated on the basis of design functions. Preconceptual designs for tunnel, shaft, and borehole seals consist of multiple zone plugs with each zone fulfilling one or more design functions. Zones of disturbed rock around tunnels and shafts, resulting from excavation and subsequent stress release, are zones of higher permeability and of possible fluid migration. In preliminary designs the disturbed zones are blocked by cut-off collars filled with low permeability materials

  12. The function of packing materials in a high-level nuclear waste repository and some candidate materials: Salt Repository Project

    International Nuclear Information System (INIS)

    Bunnell, L.R.; Shade, J.W.

    1987-03-01

    Packing materials should be included in waste package design for a high-level nuclear waste repository in salt. A packing material barrier would increase confidence in the waste package by alleviating possible shortcomings in the present design and prolonging confinement capabilities. Packing materials have been studied for uses in other geologic repositories; appropriately chosen, they would enhance the confinement capabilities of salt repository waste packages in several ways. Benefits of packing materials include retarding or chemically modifying brines to reduce corrosion of the waste package, providing good thermal conductivity between the waste package and host rock, retarding or absorbing radionuclides, and reducing the massiveness of the waste package. These benefits are available at low percentage of total repository cost, if the packing material is properly chosen and used. Several candidate materials are being considered, including oxides, hydroxides, silicates, cement-based mixtures, and clay mixtures. 18 refs

  13. Seismic design of low-level nuclear waste repositories and toxic waste management facilities

    International Nuclear Information System (INIS)

    Chung, D.H.; Bernreuter, D.L.

    1984-01-01

    Identification of the elements of typical hazardous waste facilities (HFWs) that are the major contributors to the risk are focussed on as the elements which require additional considerations in the design and construction of low-level nuclear waste management repositories and HWFs. From a recent study of six typical HWFs it was determined that the factors that contribute most to the human and environmental risk fall into four basic categories: geologic and seismological conditions at each HWF; engineered structures at each HWF; environmental conditions at each HWF; and nature of the material being released. In selecting and carrying out the six case studies, three groups of hazardous waste facilities were examined: generator industries which treat or temporarily store their own wastes; generator facilities which dispose of their own hazardous wastes on site; and industries in the waste treatment and disposal business. The case studies have a diversity of geologic setting, nearby settlement patterns, and environments. Two sites are above a regional aquifer, two are near a bay important to regional fishing, one is in rural hills, and one is in a desert, although not isolated from nearby towns and a groundwater/surface-water system. From the results developed in the study, it was concluded that the effect of seismic activity on hazardous facilities poses a significant risk to the population. Fifteen reasons are given for this conclusion

  14. Integrated management system for radioactive waste repositories (SGI3R)

    International Nuclear Information System (INIS)

    Silva, Fabio; Tello, Cledola Cassia Oliveira de

    2009-01-01

    The implantation of a repository for radioactive wastes is a multidisciplinary project that needs specialists of different areas of knowledge, interaction with public and private institutions, data and information related to radioactive wastes, geology, technology etc. All the activities must be in accordance with norms, requirements and procedures, including national and international legislation. The maintenance of the waste inventory records is an important regulatory requirement and must be available even after the closure of the repository. CDTN - Center of Nuclear Technology Development - is coordinating the Project for the construction of the national repository to dispose the low -and intermediate-level wastes. In order to consolidate all information that will come from this Project, it is being developed and implanted in CDTN a manager system of database, called Integrated Management System for Radioactive Waste Repositories (SGI3R), which will also manage all data from previous work carried out in Brazil and around the world about this subject. The proposal is to build a structure of modules, having as base eight modules: inventory, site selection, types of repository, technology, partners, legislation, communication and documents. The SGI3R running comprises the data processing (inclusion, update and exclusion), integration, standardization, and consistency among the processes. The SGI3R will give support to the stages of this Project, which will allow the preservation of all the available information, preventing duplication of efforts and additional costs, improving, in this way, the Project planning and execution. Additionally the SGI3R will make possible the information access to all stakeholders. (author)

  15. Radioactive waste repositories in hard rock aquifers--hydrodynamic aspects

    International Nuclear Information System (INIS)

    Thunvik, R.; Braester, C.

    1984-01-01

    A mathematical model for mass and heat flow and a computer program have been developed to demonstrate the effect of heat released from a hypothetical radioactive waste repository on the groundwater flow regime. The model, based on the continuum approach, conceptualizes the fracture pattern and the solid blocks as two overlapping continua and consists of a set of coupled nonlinear partial differential equations. The general form of the model is three-dimensional and can treat the fluid and rock either as two separate media with a quasi-steady exchange of heat between them or as a single equivalent medium with instantaneous thermal equilibrium. Numerical solutions have been obtained by the Galerkin finite element method. Examples have been presented for topographically different locations of the repository: below a horizontal ground surface, below a hill crest, below a hillside, and close to major fractures. The effects of constant permeability and porosity or downward decreasing with depth as well as the effect of anisotropic permeability have been investigated. Solutions include the velocity field, path lines, and traveling times of water particles passing the repository and the temperature distribution. The examples have been worked out for a two-dimensional flow domain, assuming that instantaneous thermal equilibrium takes place. This assumption was found to be justified by the relatively low flow velocities that occurred in the examples. Except for the location close to a major draining fracture, heat released from the radioactive waste repository may have a significant influence on the flow regime around the repository

  16. Learning from nuclear waste repository design: the ground-control plan

    International Nuclear Information System (INIS)

    Schmidt, B.

    1988-01-01

    At present, under a U.S. Department of Energy program, three repositories for commercial spent fuel-in salt, tuff and basalt-are in the phase of site characterization and conceptual design, and one pilot project for defense waste in salt is under development. Because of strict quality assurance requirements throughout design and construction, and the need to predict and ascertain in advance the satisfactory performance of the underground openings, underground openings in the unusual circumstances of the repository environment have been analysed. This will lead to an improved understanding of rock behavior and improved methods of underground analysis and design. A formalized ground control plan was developed, the principles of which may be applied to other types of projects. This paper summarizes the status of underground design and construction for nuclear waste repositories and presents some details of the ground control plan and its individual elements. (author)

  17. Optimized application of systems engineering to nuclear waste repository projects

    International Nuclear Information System (INIS)

    Miskimin, P.A.; Shepard, M.

    1986-01-01

    The purpose of this presentation is to describe a fully optimized application of systems engineering methods and philosophy to the management of a large nuclear waste repository project. Knowledge gained from actual experience with the use of the systems approach on two repository projects is incorporated in the material presented. The projects are currently evaluating the isolation performance of different geologic settings and are in different phases of maturity. Systems engineering methods were applied by the principal author at the Waste Isolation Pilot Plant (WIPP) in the form of a functional analysis. At the Basalt Waste Isolation Project (BWIP), the authors assisted the intergrating contractor with the development and application of systems engineering methods. Based on this experience and that acquired from other waste management projects, an optimized plan for applying systems engineering techniques was developed. The plan encompasses the following aspects: project organization, developing and defining requirements, assigning work responsibilities, evaluating system performance, quality assurance, controlling changes, enhancing licensability, optimizing project performance, and addressing regulatory issues. This information is presented in the form of a roadmap for the practical application of system engineering principles to a nuclear waste repository project

  18. Radiological consequence analysis of a repository for radioactive waste

    International Nuclear Information System (INIS)

    Fitzpatrick, J.; Buchheim, B.; Hoop, F.J.

    1982-01-01

    One of the methods under consideration for the disposal of radioactive wastes is emplacement in a repository within deep, continental formations. This paper presents the experience gained in developing a methodology to make an assessment of the radiological consequences both for normal operation and for possible accident situations for a specific repository design in a salt dome at Gorleben in Germany , designed to accommodate all categories of radioactive waste. Radionuclide release scenarios were derived from a systematic analysis of the facility design and proposed operational procedure. Where necessary simple numerical models for such topics as direct radiation exposure from waste containers, release and transport of radionuclides, radiolysis, heat transfer, creep and impact were developed to give a first estimate of the radiological consequences due to radionuclide releases. (author)

  19. Nuclear waste repository research at the micro- to nanoscale

    Science.gov (United States)

    Schäfer, T.; Denecke, M. A.

    2010-04-01

    Micro- and nano-focused synchrotron radiation techniques to investigate determinant processes in contaminant transport in geological media are becoming especially an increasingly used tool in nuclear waste disposal research. There are a number of reasons for this but primarily they are driven by the need to characterize actinide speciation localized in components of heterogeneous natural systems. We summarize some of the recent research conducted by researchers of the Institute of Nuclear Waste Disposal (INE) at the Karlsruhe Institute of Technology using micro- and nano-focused X-ray beams for characterization of colloids and their interaction with minerals and of elemental and phase distributions in potential repository host rocks and actinide speciation in a repository natural analogues sample. Such investigations are prerequisite to ensuring reliable assessment of the long term radiological safety for proposed nuclear waste disposal sites.

  20. Shale as a radioactive waste repository: the importance of vermiculite

    Energy Technology Data Exchange (ETDEWEB)

    Komarneni, S; Roy, D M; Pennsylvania State Univ., University Park; USA). Materials Research Labs.)

    1979-01-01

    Cesium sorption and fixation properties of thirty shale minerals and shales were investigated in search of a criterion for the suitability of shales for a radioactive waste repository. Shales and illites containing vermiculite fixed the largest proportion of total Cs sorbed (up to 91%) against displacement with 0.1 N KCl. For example, a slate sample fixed 33% of the total Cs sorbed while its weathered counterpart in which chlorite had altered to vermiculite fixed 89% of the total Cs sorbed. Since Cs is one of the most soluble and hazardous radioactive ions, its containment is of great importance in safe radioactive waste disposal. Presence of vermiculite in a shale body may therefore, serve as one criterion in the selection of a suitable shale for radioactive waste disposal if and when shales in geologically stable areas are selected for repositories.

  1. Uranium, thorium and trace elements in geologic occurrences as analogues of nuclear waste repository conditions

    International Nuclear Information System (INIS)

    Wollenberg, H.A.; Brookins, D.G.; Cohen, L.H.; Flexser, S.; Abashian, M.; Murphy, M.; Williams, A.E.

    1984-01-01

    Contact zones between intrusive rocks and tuff, basalt, salt and granitic rock were investigated as possible analogues of nuclear waste repository conditions. Results of detailed studies of contacts between quartz monzonite of Laramide age, intrusive into Precambrian gneiss, and a Tertiary monzonite-tuff contact zone indicate that uranium, thorium and other trace elements have not migrated significantly from the more radioactive instrusives into the country rock. Similar observations resulted from preliminary investigations of a rhyodacite dike cutting basalt of the Columbia River plateau and a kimberlitic dike cutting bedded salt of the Salina basin. This lack of radionuclide migration occurred in hydrologic and thermal conditions comparable to, or more severe than those expected in nuclear waste repository environments and over time periods of the order of concern for waste repositories. Attention is now directed to investigation of active hydrothermal systems in candidate repository rock types, and in this regard a preliminary set of samples has been obtained from a core hole intersecting basalt underlying the Newberry caldera, Oregon, where temperatures presently range from 100 to 265 0 C. Results of mineralogical and geochemical investigations of this core should indicate the alteration mineralogy and behavior of radioelements in conditions analogous to those in the near field of a repository in basalt

  2. Methods of calculating the post-closure performance of high-level waste repositories

    International Nuclear Information System (INIS)

    Ross, B.

    1989-02-01

    This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs

  3. Methods of calculating the post-closure performance of high-level waste repositories

    Energy Technology Data Exchange (ETDEWEB)

    Ross, B. (ed.)

    1989-02-01

    This report is intended as an overview of post-closure performance assessment methods for high-level radioactive waste repositories and is designed to give the reader a broad sense of the state of the art of this technology. As described here, ''the state of the art'' includes only what has been reported in report, journal, and conference proceedings literature through August 1987. There is a very large literature on the performance of high-level waste repositories. In order to make a review of this breadth manageable, its scope must be carefully defined. The essential principle followed is that only methods of calculating the long-term performance of waste repositories are described. The report is organized to reflect, in a generalized way, the logical order to steps that would be taken in a typical performance assessment. Chapter 2 describes ways of identifying scenarios and estimating their probabilities. Chapter 3 presents models used to determine the physical and chemical environment of a repository, including models of heat transfer, radiation, geochemistry, rock mechanics, brine migration, radiation effects on chemistry, and coupled processes. The next two chapters address the performance of specific barriers to release of radioactivity. Chapter 4 treats engineered barriers, including containers, waste forms, backfills around waste packages, shaft and borehole seals, and repository design features. Chapter 5 discusses natural barriers, including ground water systems and stability of salt formations. The final chapters address optics of general applicability to performance assessment models. Methods of sensitivity and uncertainty analysis are described in Chapter 6, and natural analogues of repositories are treated in Chapter 7. 473 refs., 19 figs., 2 tabs.

  4. Double Diffusive Natural Convection in a Nuclear Waste Repository

    International Nuclear Information System (INIS)

    Y. Hao; J. Nitao; T.A. Buscheck; Y. Sun

    2006-01-01

    In this study, we conduct a two-dimensional numerical analysis of double diffusive natural convection in an emplacement drift for a nuclear waste repository. In-drift heat and moisture transport is driven by combined thermal- and compositional-induced buoyancy forces. Numerical results demonstrate buoyancy-driven convective flow patterns and configurations during both repository heat-up and cool-down phases. It is also shown that boundary conditions, particularly on the drip-shield surface, have strong impacts on the in-drift convective flow and transport

  5. Information base for waste repository design. Volume 3. Waste/rock interactions

    International Nuclear Information System (INIS)

    Koplick, C.M.; Pentz, D.L.; Oston, S.G.; Talbot, R.

    1979-01-01

    This report describes the important effects resulting from interaction between radioactive waste and the rock in a nuclear waste repository. The state of the art in predicting waste/rock interactions is summarized. Where possible, independent numerical calculations have been performed. Recommendations are made pointing out areas which require additional research

  6. Coupling of Nuclear Waste Form Corrosion and Radionuclide Transports in Presence of Relevant Repository Sediments

    International Nuclear Information System (INIS)

    Wall, Nathalie A.; Neeway, James J.; Qafoku, Nikolla P.; Ryan, Joseph V.

    2015-01-01

    Assessments of waste form and disposal options start with the degradation of the waste forms and consequent mobilization of radionuclides. Long-term static tests, single-pass flow-through tests, and the pressurized unsaturated flow test are often employed to study the durability of potential waste forms and to help create models that predict their durability throughout the lifespan of the disposal site. These tests involve the corrosion of the material in the presence of various leachants, with different experimental designs yielding desired information about the behavior of the material. Though these tests have proved instrumental in elucidating various mechanisms responsible for material corrosion, the chemical environment to which the material is subject is often not representative of a potential radioactive waste repository where factors such as pH and leachant composition will be controlled by the near-field environment. Near-field materials include, but are not limited to, the original engineered barriers, their resulting corrosion products, backfill materials, and the natural host rock. For an accurate performance assessment of a nuclear waste repository, realistic waste corrosion experimental data ought to be modeled to allow for a better understanding of waste form corrosion mechanisms and the effect of immediate geochemical environment on these mechanisms. Additionally, the migration of radionuclides in the resulting chemical environment during and after waste form corrosion must be quantified and mechanisms responsible for migrations understood. The goal of this research was to understand the mechanisms responsible for waste form corrosion in the presence of relevant repository sediments to allow for accurate radionuclide migration quantifications. The rationale for this work is that a better understanding of waste form corrosion in relevant systems will enable increased reliance on waste form performance in repository environments and potentially

  7. Coupling of Nuclear Waste Form Corrosion and Radionuclide Transports in Presence of Relevant Repository Sediments

    Energy Technology Data Exchange (ETDEWEB)

    Wall, Nathalie A. [Washington State Univ., Pullman, WA (United States); Neeway, James J. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Qafoku, Nikolla P. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States); Ryan, Joseph V. [Pacific Northwest National Lab. (PNNL), Richland, WA (United States)

    2015-09-30

    Assessments of waste form and disposal options start with the degradation of the waste forms and consequent mobilization of radionuclides. Long-term static tests, single-pass flow-through tests, and the pressurized unsaturated flow test are often employed to study the durability of potential waste forms and to help create models that predict their durability throughout the lifespan of the disposal site. These tests involve the corrosion of the material in the presence of various leachants, with different experimental designs yielding desired information about the behavior of the material. Though these tests have proved instrumental in elucidating various mechanisms responsible for material corrosion, the chemical environment to which the material is subject is often not representative of a potential radioactive waste repository where factors such as pH and leachant composition will be controlled by the near-field environment. Near-field materials include, but are not limited to, the original engineered barriers, their resulting corrosion products, backfill materials, and the natural host rock. For an accurate performance assessment of a nuclear waste repository, realistic waste corrosion experimental data ought to be modeled to allow for a better understanding of waste form corrosion mechanisms and the effect of immediate geochemical environment on these mechanisms. Additionally, the migration of radionuclides in the resulting chemical environment during and after waste form corrosion must be quantified and mechanisms responsible for migrations understood. The goal of this research was to understand the mechanisms responsible for waste form corrosion in the presence of relevant repository sediments to allow for accurate radionuclide migration quantifications. The rationale for this work is that a better understanding of waste form corrosion in relevant systems will enable increased reliance on waste form performance in repository environments and potentially

  8. Microbial processes in radioactive waste repository

    International Nuclear Information System (INIS)

    Gazso, L.; Farkas-Galgoczi, G.; Diosi, G.

    2002-01-01

    Microbial processes could potentially affect the performance of a radioactive waste disposal system and related factors that could have an influence on the mobility of radionuclides are outlined. Analytical methods, including sampling of water, rock and surface swabs from a potential disposal site, are described and the quantitative as well as qualitative experimental results obtained are given. Although the results contribute to an understanding of the impact of microbial processes on deep geological disposal of nuclear waste, there is not yet sufficient information for a model which will predict the consequences of these processes. (author)

  9. Refinancing of the search for a repository and of the repository for heat generating radioactive waste. Pt. 1

    International Nuclear Information System (INIS)

    Moench, Christoph

    2013-01-01

    The final disposal of radioactive waste is a state task that is assigned to the Federal Government pursuant to section 9a (3) sentence 1 of the Atomic Energy Act (AtG). Since the early 1970's, the Federal Government has been actively searching for and exploring final disposal sites for radioactive waste. In a proceeding accompanied by the intensive participation of technical experts and the public, the Gorleben salt dome (Salzstock) has emerged as a presumably suitable disposal site from a mining standpoint (eignungshoeffig) according to the current status of the exploration. The cost of these exploratory measures - and the subsequent construction - will be financed by the waste producers, in particular the utility companies, by means of advance payments on their contributions. Part I of this article will evaluate the selection and exploration of the Gorleben salt dome to date and examine the provisions on the pre-financing burden from the point of view of constitutional law. Constitutional objections can also be raised against the regulation in section 21b (4) AtG that was introduced in 1998, which excludes a refunding of the pre-financing contributions even if the repository is never erected or operated. Part II of this article, which will appear in the next issue, will take up the question of whether a search for an alternative repository site, as the Federal Ministry for the Environment (BMU) envisions in the working draft of an 'Act on the search for and selection of a site for a repository for heat generating radioactive waste' (Gesetz zur Suche und Auswahl eines Standortes fuer ein Endlager fuer waermeentwickelnde radioaktive Abfaelle), is likewise to be refinanced as a contribution by the parties obliged to make advance payments. (orig.)

  10. Salt Repository Project waste emplacement mode decision paper: Revison 1

    International Nuclear Information System (INIS)

    1987-08-01

    This paper provides a recommendation as to the mode of waste emplacement to be used as the current basis for site characterization activity for the Deaf Smith County, Texas, high level nuclear waste repository site. It also presents a plan for implementing the recommendation so as to provide a high level of confidence in the project's success. Since evaluations of high-level waste disposal in geologic repositories began in the 1950s, most studies emplacement in salt formations employed the vertical orientation for emplacing waste packages in boreholes in the floor of the underground facility. This orientation was used in trials at Project Salt Vault in the 1960s. The Waste Isolation Pilot Plant (WIPP) has recently settled on a combination of vertical and horizontal modes for various waste types. This paper analyzes the information available and develops a project position upon which to base current site characterization activities. The position recommended is that the SRP should continue to use the vertical waste emplacement mode as the reference design and to carry the horizontal mode as a ''passive'' alternative. This position was developed based upon the conclusions of a decision analysis, risk assessment, and cost/schedule impact assessment. 52 refs., 6 figs., 1 tab

  11. Different types of radioactive waste repositories, each suited for a given type of radioactive waste - 59293

    International Nuclear Information System (INIS)

    Voinis, Sylvie; Boissier, Fabrice; Griffault, Lise; Maillard, Jean Louis; Dutzer, Michel

    2012-01-01

    Document available in abstract form only. Full text of publication follows: The aim of this article is to present how Andra implements a dedicated solution per waste category. It relies on response to a series of questions concerning the appropriate waste disposal system such as: What type of radiological inventory is involved? What are the half-lives of the radionuclides and the associated timescales concerned for achieving the fundamental protection objective? In that respect, Andra has developed and has implemented methods for all disposal facilities in order to reach common objectives: The immediate and long term protections of human beings and the environment constitute the fundamental objectives of all radioactive-waste disposal facilities. In order to achieve those protections, disposal facilities must be safe. Thus, Andra safety encompasses all design, implementation and operational measures for preventing risks of all kind internal, external during operation and after closure in consistency with defense in depth principles taken into account the peculiarity of waste disposal facilities: (i) balancing operational safety and post-closure safety, (ii) management of nuclear risks in underground repository for some of them, (iii) management of scientific understanding and related uncertainties, and (iv) management of long or very long- timescales. The presentation will illustrate Andra's approach that has or will be conducted and will focus on communalities or peculiarities according to the type of waste and related disposal options regarding the following iterative steps: regulatory safety rules, input data, scenarios, safety assessments. (authors)

  12. Ethical considerations surrounding nuclear waste repository siting and mitigation

    International Nuclear Information System (INIS)

    Peters, T.F.

    1983-01-01

    The potential long-term health and safety effects of the nuclear materials stored in repositories, the extremely long periods of time over which such materials may be dangerous, and the equity implications of the siting of a repository in any given area are unlike the issues involved in other large-scale projects. They involve major philosophical issues basic to human perspectives on social relationships and on insuring the future of mankind. Safety and permanence are the two basic criteria for determining whether a waste proposal is satisfactory. This chapter takes the approach of public (or micro) ethics, whose task is to 1) articulate and clarify public values relevant to a problem, 2) identify and evaluate public options, and 3) rank alternatives in some order of ethical preferability. It addresses the four major repository-related issues: uncertainty and risks, geographic equity, intergenerational ethics, and implementation ethics

  13. Safety analysis methodologies for radioactive waste repositories in shallow ground

    International Nuclear Information System (INIS)

    1984-01-01

    The report is part of the IAEA Safety Series and is addressed to authorities and specialists responsible for or involved in planning, performing and/or reviewing safety assessments of shallow ground radioactive waste repositories. It discusses approaches that are applicable for safety analysis of a shallow ground repository. The methodologies, analysis techniques and models described are pertinent to the task of predicting the long-term performance of a shallow ground disposal system. They may be used during the processes of selection, confirmation and licensing of new sites and disposal systems or to evaluate the long-term consequences in the post-sealing phase of existing operating or inactive sites. The analysis may point out need for remedial action, or provide information to be used in deciding on the duration of surveillance. Safety analysis both general in nature and specific to a certain repository, site or design concept, are discussed, with emphasis on deterministic and probabilistic studies

  14. Evaluation of iron-base materials for waste package containers in a salt repository

    International Nuclear Information System (INIS)

    Westerman, R.E.; Nelson, J.L.; Kuhn, W.L.; Basham, S.G.; Moak, D.A.; Pitman, S.G.

    1983-11-01

    Design studies for high-level nuclear waste packages for salt repositories have identified low-carbon steel as a candidate material for containers. Among the requirements are strength, corrosion resistance, and fabricability. The studies of the corrosion resistance and structural stability of iron-base materials (particularly low-carbon steel) are treated in this paper. The materials have been exposed in brines that are characteristic of the potential sites for salt repositories. The effects of temperature, radiation level, oxygen level and other parameters are under investigation. The initial development of corrosion models for these environments is presented with discussion of the key mechanisms under consideration. 6 references, 5 figures

  15. Reconstruction and modernization of Novi Han radioactive waste repository

    International Nuclear Information System (INIS)

    Kolev, I.; Dralchev, D.; Spasov, P.; Jordanov, M.

    2000-01-01

    This report presents briefly the most important issues of the study performed by EQE - Bulgaria. The objectives of the study are the development of conceptual solutions for construction of the following facilities in the Novi Han radioactive waste repository: an operational storage for unconditioned high level spent sources; new temporary buildings over the existing radioactive waste storage facilities; a rain-water draining system ect. The study also includes the engineering solutions for conservation of the existing facilities, currently full with high level spent sources. A 'Program for reconstruction and modernization' has been created, including the analysis of some regulation aspects concerning this program implementation. In conclusions the engineering problems of Novi Han repository are clear and appropriate solutions are available. They can be implemented in both cases of 'small' or 'large' reconstruction. The reconstruction project anyway should start with the construction of a new site infrastructure. Reconstruction and modernization of Novi Han radioactive waste repository is the only way to improve the management and safety of radioactive waste from medicine, industry and scientific research in Bulgaria

  16. Preliminary research work on building of repositories for burial of NPP radioactive waste in loess beds

    International Nuclear Information System (INIS)

    Stefanov, G.; Prodanov, Ya.

    1984-02-01

    The choice of a disposal site for burial of intermediate and low-level wastes from the NPS depends on a complex of conditions, requirements and methods resulting from the complex geologo-geographic and demographic conditions in the People's Republic of Bulgaria. The analysis of the geologic conditions shows that the various structures of the rocks, the tectonism, the seismicity in vast regions, the lack of plateau basalts hinder the choice of convenient sites for radioactive waste disposal. In Bulgaria the loess massives are studied and proposals are made to use them as a suitable environment for building of radioactive waste repositories

  17. Workshop on development of radionuclide getters for the Yucca Mountain waste repository: proceedings.

    Energy Technology Data Exchange (ETDEWEB)

    Moore, Robert Charles; Lukens, Wayne W. (Lawrence Berkeley National Laboratory)

    2006-03-01

    The proposed Yucca Mountain repository, located in southern Nevada, is to be the first facility for permanent disposal of spent reactor fuel and high-level radioactive waste in the United States. Total Systems Performance Assessment (TSPA) analysis has indicated that among the major radionuclides contributing to dose are technetium, iodine, and neptunium, all of which are highly mobile in the environment. Containment of these radionuclides within the repository is a priority for the Yucca Mountain Project (YMP). These proceedings review current research and technology efforts for sequestration of the radionuclides with a focus on technetium, iodine, and neptunium. This workshop also covered issues concerning the Yucca Mountain environment and getter characteristics required for potential placement into the repository.

  18. The aeration period of a model nuclear waste repository

    International Nuclear Information System (INIS)

    Sharland, S.M.; Tasker, P.W.

    1987-02-01

    We have constructed a model of the evolution of oxygen in a cement backfill which includes both its depletion through the canister corrosion reactions and its migration in the cement pores. The results indicate that the duration in which mild steel waste canisters may be subject to localised corrosion is very much shorter than the intended lifetime of the repository components, provided there is no external source of oxygen. For canisters spaced 1.2m apart, the model predicts a maximum aeration period of approximately 65 years, assuming high oxygen content and diffusivity in the backfill and low leakage current on the canisters (0.01 μA cm -2 ). In such a case a reducing environment is established throughout the backfill within this period. Under conditions of more restricted oxygen transport, reducing conditions are still established within a relatively short time in the immediate vicinity of the canisters, but the oxidation potential elsewhere in the backfill is then controlled by the uniform corrosion rate of the canisters. (author)

  19. Evolution of the groundwater chemistry around a nuclear waste repository

    International Nuclear Information System (INIS)

    Haworth, A.; Sharland, S.M.; Tasker, P.W.; Tweed, C.J.

    1987-12-01

    Some of the necessary techniques to construct a research model of the evolution of the groundwater under the influence of the backfill material in a nuclear waste repository are developed. These involve various extensions to the coupled ionic migration and chemical equilibria code, CHEQMATE. These extensions have been used in the first stages of a model of the chemical environment within the host rock. In this preliminary model we have considered a concrete backfill material embedded in a clay geology. However, the model is sufficiently flexible that other backfill materials and host rocks may be considered if a good thermodynamical description is available. The preliminary results from the model suggest that over timescales of about a thousand years the natural buffering action of the clay against changes in pH has a significant effect on the scale of perturbation by the ingress of highly alkaline porewater. It seems likely therefore that this type of modelling will have considerable relevance to the safety assessment models. (author)

  20. Information about activity, status and radiation conditions of Republic radioactive waste repository

    International Nuclear Information System (INIS)

    Saidumarov, P.

    2000-01-01

    All radioactive wastes in the Republic of Uzbekistan are stored in the Republic Radioactive Waste Repository in Parkent district of Tashkent region. In the facility there are 2 tanks for solid radioactive waste, each of 800 m 3 , one of them is full, second is in operation; 2 tanks for liquid radioactive waste each tank of 200 m 3 , both of them are empty; 6 storages, each of 3 m 3 all of them are empty; 3 storages for spent radioactive sources, one of them is full, 2 of them are in operation; 4 storages for high level radioactive waste, each storage of 3.5 m 3 , one of them is in operation, 3 are empty; one sealed storage containing 135 m 3 of concrete blocks with waste from electronic industry. According to conclusions of a few competent examinations RRWR does not cause damage to the environment. Geographic location and technical conditions of the repository are satisfactory. Low deposition of underground water (62 m) excludes penetration of radioisotopes. There were no radiation accidents during the repository operation

  1. Safety Assessment of Radioactive waste Repositories

    International Nuclear Information System (INIS)

    1991-01-01

    It is planned to dispose of high-level radioactive wastes in deep geological formations. To access the long-term safety of radioactive waste disposal systems, mathematical models are used to describe groundwater flow, chemistry and potential radionuclide migration through these formations. Establishing the validity of such models is important in order to obtain the necessary confidence in the safety of the disposal method. The papers in these proceedings of the GEOVAL'90 Symposium describe the current state of knowledge on the validation of geosphere flow and transport models. This symposium, divided into five sessions, contains 65 technical papers: session 1 - Necessity of validation. Session 2 - Progress in validation of flow and transport models in orystalline rock, unsaturated media, salt media or clay. Session 3 - Progress in validation of geochemical models. Session 4 - Progress in validation of coupled thermo-hydro-mechanical effects. Session 5 - Validation strategy

  2. Barriers to migration of radionuclides from radioactive waste repositories

    International Nuclear Information System (INIS)

    Stefanova, I.

    1999-01-01

    Natural inorganic sorbents are known as effective barriers that reduce the migration of radionuclides from radioactive waste repositories and contaminated sites. They could be used as buffer, backfill and sealing materials in the repository and their presence in the host rock and the surrounding geological formations increases the retention properties of the strata. Natural occurring minerals from local origin are used in the study - zeolites (clinoptilolite and mordenite), celadonite and loess. Sorption of wide range of radionuclides is studies. Batch capacity is determined. Sorption of radionuclides from simulated natural solution is studied. Distribution coefficients are calculated from sorption isotherms. Desorption in presence of different natural solutions is studied. Sorption properties are compared. It is shown that clinoptilolite acts as effective barrier against migration of radionuclides from repositories. The presence of celadonite in the clinoptilolite rock increases the retention of polyvalent ions. The retention of radionuclides on loess samples fulfils the requirements for host media for repository for low and intermediate level waste. A method for construction of additional barrier to the existing in the country disposal vault for spent sealed sources is proposed

  3. Enlargement of the Baldone near-surface radioactive waste repository

    International Nuclear Information System (INIS)

    Dreimanis, A.

    2007-01-01

    A unified analysis of the enlargement of the Baldone near-surface radioactive waste (RW) repository RADONS considers the interplay of the existing engineering, safety and infrastructure premises, with the foreseen newly socio-technical features. This enlargement consists in construction of two additional RW disposal vaults and in building a long-term storage facility for spent sealed sources at the RADONS territory. Our approach is based on consecutive analysis of following basic elements: - the origin of enlargement - the RADONS safety analysis and a set of optimal socio-technical solutions of Salaspils research reactor decommissioning waste management; - the enlargement - a keystone of the national RW management concept, including the long-term approach; - the enlargement concept - the result of international co-operation and obligations; - arrangement optimization of new disposal and storage space; - environmental impact assessment for the repository enlargement - the update of socio-technical studies. The study of the public opinion revealed: negative attitude to repository enlargement is caused mainly due to missing information on radiation level and on the RADONS previous operations. These results indicate: basic measures to improve the public attitude to repository enlargement: the safety upgrade, public education and compensation mechanisms. A detailed stakeholders engagement and public education plan is elaborated. (author)

  4. Nuclear waste repository transparency technology test bed demonstrations at WIPP

    International Nuclear Information System (INIS)

    Betsill J, David; Elkins, Ned Z.; Wu, Chuan-Fu; Mewhinney, James D.; Aamodt, Paul

    2000-01-01

    Secretary of Energy, Bill Richardson, has stated that one of the nuclear waste legacy issues is ''The challenge of managing the fuel cycle's back end and assuring the safe use of nuclear power.'' Waste management (i.e., the back end) is a domestic and international issue that must be addressed. A key tool in gaining acceptance of nuclear waste repository technologies is transparency. Transparency provides information to outside parties for independent assessment of safety, security, and legitimate use of materials. Transparency is a combination of technologies and processes that apply to all elements of the development, operation, and closure of a repository system. A test bed for nuclear repository transparency technologies has been proposed to develop a broad-based set of concepts and strategies for transparency monitoring of nuclear materials at the back end of the fuel/weapons cycle. WIPP is the world's first complete geologic repository system for nuclear materials at the back end of the cycle. While it is understood that WIPP does not currently require this type of transparency, this repository has been proposed as realistic demonstration site to generate and test ideas, methods, and technologies about what transparency may entail at the back end of the nuclear materials cycle, and which could be applicable to other international repository developments. An integrated set of transparency demonstrations was developed and deployed during the summer, and fall of 1999 as a proof-of-concept of the repository transparency technology concept. These demonstrations also provided valuable experience and insight into the implementation of future transparency technology development and application. These demonstrations included: Container Monitoring Rocky Flats to WIPP; Underground Container Monitoring; Real-Time Radiation and Environmental Monitoring; Integrated level of confidence in the system and information provided. As the world's only operating deep geologic

  5. Draft environmental impact statement. High-level waste repository site suitability criteria

    International Nuclear Information System (INIS)

    1978-01-01

    The purpose of HLWRSSC is to present guidelines which will help in the development of safe waste management schemes. Current regulations require solidification of all high-level waste within 5 years of their generation and transfer to a Federal waste repository within 10 years. Development of the proposed HLWRSSC is part of the overall NRC program to close the ''back end'' of the commercial LWR fuel cycle. In this document, the need for the HLWRSSC is reviewed, and the national energy policy, the need for electrical energy, and the nuclear fuel cycle are discussed. Considerations for HLWRSSC are presented, including the nature of the repository, important site-related factors, and radiological risk assessment methodology. Radiological and nonradiological environment impacts associated with the HLWRSSC are defined. Alternatives to the criteria are presented, and the cost-benefit-risk evaluation is reviewed

  6. Iron-nickel alloys as canister material for radioactive waste disposal in underground repositories

    International Nuclear Information System (INIS)

    Apps, J.A.

    1982-01-01

    Canisters containing high-level radioactive waste must retain their integrity in an underground waste repository for at least one thousand years after burial (Nuclear Regulatory Commission, 1981). Since no direct means of verifying canister integrity is plausible over such a long period, indirect methods must be chosen. A persuasive approach is to examine the natural environment and find a suitable material which is thermodynamically compatible with the host rock under the environmental conditions with the host rock under the environmental conditions expected in a waste repository. Several candidates have been proposed, among them being iron-nickel alloys that are known to occur naturally in altered ultramafic rocks. The following review of stability relations among iron-nickel alloys below 350 0 C is the initial phase of a more detailed evaluation of these alloys as suitable canister materials

  7. The Poco de Caldas project: Natural analogues of processes in a radioactive waste repository

    International Nuclear Information System (INIS)

    Chapman, N.A.; McKinley, I.G.; Shea, M.E.; Smellie, J.A.T.

    1993-01-01

    The safe disposal of radioactive wastes by burial in deep geologic formations requires long-term predictions of the future behavior of the wastes nd their engineered repository. Such predictions can be tested by evaluating processes analogous to those which will occur in a repository, which have been long active in the natural geochemical environment. The title project is a comprehensive study of two ore deposits in Minas Gerais, Brasil, aimed at looking at uranium and thorium series radionuclide and rare earth element mobility, the development and movement of redox fronts, and the nature of natural groundwater colloids. A multidisciplinary team of experts from 27 laboratories carried out a fully integrated study of the geology, geomorphology, hydrogeology, geochemistry, hydrochemistry and geomicrobiology of the two sited for nearly four years. This book contains 20 papers covering the detailed findings, with particular emphasis on their significance for radioactive waste disposal, especially on the use of the data in testing models of radionuclide movement

  8. A conceptual subsurface facility design for a high-level nuclear waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    McKenzie, D.G., III; Bhattacharyya, K.K.; Segrest, A.M.

    1996-01-01

    The US Department of Energy is responsible for the design, construction, operation and closure of a repository in which to permanently dispose of the nation's high level nuclear waste. In addition to the objective of safely isolating the waste inventory, the repository must provide a safe working environment for its workforce, and protect the public. The conceptual design for this facility is currently being developed. Tunnel Boring Machine will be used to excavate 228 kilometers of tunneling to construct the facility over a 30 year period. The excavation operations will be physically separated from the waste emplacement operations, and each operation will have its own dedicated ventilation system. The facility is being designed to remain open for 150 years

  9. The Hidden Risk Decisions in Waste Repository Regulation

    International Nuclear Information System (INIS)

    Frishman, Steve

    2001-01-01

    The move toward risk-informed, performance-based regulation of activities involving radioactive materials is becoming wide spread and broadly applied. While this approach may have some merit in specific applications in which there is a considerable body of experience, its strict application in regulation of geologic repositories for highly radioactive wastes may not be appropriate for this unproven and socially controversial technology. The U.S. Nuclear Regulatory Commission describes risk-informed, performance-based regulation as 'an approach in which risk insights, engineering analysis and judgement (eg. defense in depth), and performance history are used to (1) focus attention on the most important activities, (2) establish objective criteria based upon risk insights for evaluating performance, (3) develop measurable or calculable parameters for monitoring system and licensee performance, and (4) focus on the results as the primary basis for regulatory decision-making.' Both the risk-informed and performance-based elements of the approach are problematic when considering regulation of geologic repositories for highly radioactive wastes - an activity yet to be accomplished by any nation. In investigating potential sites for geologic repositories there will always be residual uncertainty in understanding the natural system and the events and processes that affect it. The more complex the natural system, the greater will be the uncertainty in both the data and the models used to describe the characteristics of the site's natural barriers, and the events and processes that could affect repository waste isolation. The engineered barriers also are subject to uncertainties that are important to the repository system. These uncertainties translate themselves into a range of probabilities that certain events or processes, detrimental to waste isolation, will occur. The uncertainties also translate to a range of consequences and magnitudes of consequences, should the

  10. Safety assessment of geologic repositories for nuclear waste

    International Nuclear Information System (INIS)

    Bartlett, J.W.; Burkholder, H.C.; Winegardner, W.K.

    1977-01-01

    Consideration of geologic isolation for final disposition of radioactive wastes has led to the need for evaluation of the safety of the concept. Such evaluations require consideration of factors not encountered in conventional risk analysis: consequences at times and places far removed from the repository site; indirect, complex, and alternative pathways between the waste and the point of potential consequences; a highly limited data base; and limited opportunity for experimental verification of results. R and D programs to provide technical safety evaluations are under way. Three methods are being considered for the probabilistic aspects of the evaluations: fault tree analysis, repository simulation analysis, and system stability analysis. Nuclide transport models, currently in a relatively advanced state of development, are used to evaluate consequences of postulated loss of geologic isolation. This paper outlines the safety assessment methods, unique features of the assessment problem that affect selection of methods and reliability of results, and available results. It also discusses potential directions for future work

  11. The technical challenge of mechanized excavation for nuclear waste repositories

    International Nuclear Information System (INIS)

    Smith, A.I.

    1991-01-01

    This paper presents the historical background of the tunnel boring machine and discusses its integration into the design of a nuclear waste repository. It is essential that the designers of a project utilize the productivity of the system to their advantage. An example would be the construction of a pair of small tunnels instead of a single large diameter access ramp. The pair of tunnels would be more effective in use and less expensive to bore than the single all-purpose tunnel. The designers of an underground nuclear waste repository must recognize the capabilities of the Tunnel Boring Machine system and tailor their design to employ the technological advantages which have been made in recent years

  12. Repository documentation rethought. A comprehensive approach from untreated waste to waste packages for final disposal

    Energy Technology Data Exchange (ETDEWEB)

    Anthofer, Anton Philipp; Schubert, Johannes [VPC GmbH, Dresden (Germany)

    2017-11-15

    The German Act on Reorganization of Responsibility for Nuclear Disposal (Entsorgungsuebergangsgesetz (EntsorgUebG)) adopted in June 2017 provides the energy utilities with the new option of transferring responsibility for their waste packages to the Federal Government. This is conditional on the waste packages being approved for delivery to the Konrad final repository. A comprehensive approach starts with the dismantling of nuclear facilities and extends from waste disposal and packaging planning to final repository documentation. Waste package quality control measures are planned and implemented as early as in the process qualification stage so that the production of waste packages that are suitable for final deposition can be ensured. Optimization of cask and loading configuration can save container and repository volume. Workflow planning also saves time, expenditure and exposure time for personnel at the facilities. VPC has evaluated this experience and developed it into a comprehensive approach.

  13. Dispute resolution in the nuclear waste repository program

    International Nuclear Information System (INIS)

    Creighton, J.L.; Shorett, A.J.

    1988-01-01

    During 1987 a seven-person team addressed just that question for the State of Washington, as part of the studies of the socioeconomic impacts of a possible nuclear waste repository site at the Hanford site. The authors were, respectively, the Mitigation/Compensation team leader and the conflict resolution specialist within the team. While the studies were terminated when Congress selected the Nevada site, the conclusions may still have value for the State of Nevada, or for other controversial federal projects

  14. Melodie: A global risk assessment model for radioactive waste repositories

    International Nuclear Information System (INIS)

    Lewi, J.; Assouline, M.; Bareau, J.; Raimbault, P.

    1987-03-01

    The Institute of Protection and Nuclear Safety (IPSN), which is part of the French Atomic Energy Commission (C.E.A.) develops since 1984 in collaboration with different groups inside and outside the C.E.A. a computer model for risk assessment of nuclear waste repositories in deep geological formations. The main characteristics of the submodels, the data processing structure and some examples of applications are presented

  15. Research on high level radioactive waste repository seismic design criteria

    International Nuclear Information System (INIS)

    Jing Xu

    2012-01-01

    Review seismic hazard analysis principle and method in site suitable assessment process of Yucca Mountain Project, and seismic design criteria and seismic design basis in primary design process. Demonstrated spatial character of seismic hazard by calculated regional seismic hazard map. Contrasted different level seismic design basis to show their differences and relation. Discussed seismic design criteria for preclosure phrase of high level waste repository and preference goal under beyond design basis ground motion. (author)

  16. Establishing managerial requirements for low-and intermediate-level waste repository

    International Nuclear Information System (INIS)

    Chung, C. W.; Lee, Y. K.; Kim, H. T.; Park, W. J.; Suk, T. W.; Park, S. H.

    2004-01-01

    This paper reviews basic considerations for establishing managerial requirements on the domestic low-and intermediate-level radioactive waste repository and presents the corresponding draft requirements. The draft emphasizes their close linking with the related regulations, standards and safety assessment for the repository. It also proposes a desirable direction towards harmonizing together with the existing waste acceptance requirements for the repository

  17. Uncertainties in sealing a nuclear waste repository in partially saturated tuff

    International Nuclear Information System (INIS)

    Tillerson, J.R.; Fernandez, J.A.; Hinkebein, T.E.

    1989-01-01

    Sealing a nuclear waste repository in partially saturated tuff presents unique challenges to assuring performance of sealing components. Design and performance of components for sealing shafts, ramps, drifts, and exploratory boreholes depend on specific features of both the repository design and the site; of particular importance is the hydrologic environment in the unsaturated zone, including the role of fracture flow. Repository design features important to sealing of a repository include the size and location of shaft and ramp accesses, excavation methods, and the underground layout features such as grade (drainage direction) and location relative to geologic structure. Uncertainties about seal components relate to the postclosure environment for the seals, the emplacement methods, the material properties, and the potential performance of the components. An approach has been developed to reduce uncertainties and to increase confidence in seal performance; it includes gathering extensive site characterization data, establishing conservative design requirements, testing seal components in laboratory and field environments, and refining designs of both the seals and the repository before seals are installed. 9 refs., 5 figs., 2 tabs

  18. Nuclear waste repository ventilation system studies

    International Nuclear Information System (INIS)

    Smith, P.R.; Hensel, E.C.; Leslie, I.H.; Schultheis, T.M.; Walls, J.R.; Gregory, W.S.

    1993-01-01

    Ventilation studies of the Waste Isolation Pilot Plant described in this article were performed by personnel from New Mexico State University in collaboration with Sandia National Laboratories, Los Alamos National Laboratory, and Westinghouse Corporation. The following research tasks were performed: 1) High-efficiency particulate air filters of the type used at the Waste Isolation Pilot Plant were loaded with salt aerosol from the site, 2) Filter resistance as a function of salt mass and flow rate was established for later use in computer simulations, 3) Filter efficiency was measured during the loading tests to establish a relation between efficiency and salt loading, 4) The structural strength of the salt-loaded high-efficiency filters was investigated by subjecting the filters to pressure transients of the types expected from fires, explosions and tornados, 5) Computer codes, obtained from Los Alamos National Laboratory, were used to model the ventilation systems and study their response to accident-induced pressure transients and heat fluxes, 6) Partial verification of the computer simulations was obtained by comparing normal operation of the ventilation systems to predicted normal operation, 7) A feasibility study using model-based control of the ventilation systems was initiated and will be completed during the second year of the project. (author) 12 figs., 16 refs

  19. Geoscience data base handbook for modeling a nuclear waste repository. Volume 1

    International Nuclear Information System (INIS)

    Isherwood, D.

    1979-12-01

    This handbook contains reference information on parameters that should be considered in analyzing or modeling a proposed nuclear waste repository site. Only those parameters and values that best represent the natural environment are included. Rare extremes are avoided. Where laboratory and field data are inadequate, theoretical treatments and informed engineering judgements are presented. Volume 1 contains a data base on salt as a repository medium. Chapters on the geology of bedded and dome salt, the geomechanics of salt, hydrology, geochemistry, natural and man-made features, and seismology provide compiled data and related information useful for studying a proposed repository in salt. These and other data will be needed to derive generic deep geologic modeling parameters and will also serve as background for the verification of source data that may be presented in licensing applications for nuclear waste repositories. Volume 2 is the result of a scoping study for a data base on the geology, geomechanics, and hydrology of shale, granite, and basalt as alternative repository media. Except for the geomechanics of shale, most of the sections contain relatively complete compilations of the available data, as well as discussions of the properties that are unique to each rock type

  20. Preliminary drift design analyses for nuclear waste repository in tuff

    International Nuclear Information System (INIS)

    Hardy, M.P.; Brechtel, C.E.; Goodrich, R.R.; Bauer, S.J.

    1990-01-01

    The Yucca Mountain Project (YMP) is examining the feasibility of siting a repository for high-level nuclear waste at Yucca Mountain, on and adjacent to the Nevada Test Site (NTS). The proposed repository will be excavated in the Topopah Spring Member, which is a moderately fractured, unsaturated, welded tuff. Excavation stability will be required during construction, waste emplacement, retrieval (if required), and closure to ensure worker safety. The subsurface excavations will be subject to stress changes resulting from thermal expansion of the rock mass and seismic events associated with regional tectonic activity and underground nuclear explosions (UNEs). Analyses of drift stability are required to assess the acceptable waste emplacement density, to design the drift shapes and ground support systems, and to establish schedules and cost of construction. This paper outlines the proposed methodology to assess drift stability and then focuses on an example of its application to the YMP repository drifts based on preliminary site data. Because site characterization activities have not begun, the database currently lacks the extensive site-specific field and laboratory data needed to form conclusions as to the final ground support requirements. This drift design methodology will be applied and refined as more site-specific data are generated and as analytical techniques and methodologies are verified during the site characterization process

  1. Thermal Analysis of a Nuclear Waste Repository in Argillite Host Rock

    Science.gov (United States)

    Hadgu, T.; Gomez, S. P.; Matteo, E. N.

    2017-12-01

    Disposal of high-level nuclear waste in a geological repository requires analysis of heat distribution as a result of decay heat. Such an analysis supports design of repository layout to define repository footprint as well as provide information of importance to overall design. The analysis is also used in the study of potential migration of radionuclides to the accessible environment. In this study, thermal analysis for high-level waste and spent nuclear fuel in a generic repository in argillite host rock is presented. The thermal analysis utilized both semi-analytical and numerical modeling in the near field of a repository. The semi-analytical method looks at heat transport by conduction in the repository and surroundings. The results of the simulation method are temperature histories at selected radial distances from the waste package. A 3-D thermal-hydrologic numerical model was also conducted to study fluid and heat distribution in the near field. The thermal analysis assumed a generic geological repository at 500 m depth. For the semi-analytical method, a backfilled closed repository was assumed with basic design and material properties. For the thermal-hydrologic numerical method, a repository layout with disposal in horizontal boreholes was assumed. The 3-D modeling domain covers a limited portion of the repository footprint to enable a detailed thermal analysis. A highly refined unstructured mesh was used with increased discretization near heat sources and at intersections of different materials. All simulations considered different parameter values for properties of components of the engineered barrier system (i.e. buffer, disturbed rock zone and the host rock), and different surface storage times. Results of the different modeling cases are presented and include temperature and fluid flow profiles in the near field at different simulation times. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology and

  2. Reconstruction and modernization of Novi Han radioactive waste repository

    International Nuclear Information System (INIS)

    Kolev, I.

    2001-01-01

    The paper is an overview of the Feasibility Study for Reconstruction and Modernisation of Novi Han Radioactive Waste Repository (NHRWR), performed by EQE Bulgaria AD in 2000 for the Institute for Nuclear Research and Nuclear Energy of the Bulgarian Academy of Sciences. The Study develops a concept for overall reconstruction and modernisation of NHRWR, including rehabilitation and partial reconstruction of existing facilities and planning of new facilities for conditioning and storage of various radioactive wastes and spent sealed sources. The paper presents the general modernisation concept and outlines the proposed principle technical solutions for the existing and new facilities. (author)

  3. Towards a spectroscopic standard database for Pu in repository environments

    International Nuclear Information System (INIS)

    Amme, M.

    2005-01-01

    Full text of publication follows: The alteration behaviour of Pu in geological and technical environments is, although of crucial importance for example in final repository assessment procedures for high-level nuclear waste, not sufficiently investigated. Since Pu chemistry differs significantly from U behaviour (mostly due to the different stabilities of the +IV oxidation states of both elements), conclusions based on the uranium analogy cannot be extended to Pu chemistry in many cases. In order to examine precisely the alteration behaviour of Pu under repository storage conditions, customized tools for the spectroscopic identification of the element need to be developed. We are currently constructing systematically a database of Pu compounds and collect their spectra for this purpose. Pu compounds (with the element in the oxidation states +III, +IV, +V, and +VI) are synthesised, mostly by using hydrothermal synthesis techniques [1]. Compounds of high importance for repository studies are: Carbonates, (oxy)hydroxides, silicates, peroxides, and phosphates. The products are characterised by Scanning Electron Microscopy (SEM), X-Ray Photoelectron spectroscopy (XPS), and X-Ray diffraction (XRD). Furthermore, vibrational spectra (Raman and IR) of the substances will be recorded. These will allow the unambiguous identification of chemically similar compounds, once the database is compiled: Although reported for a few cases with nuclear material only, the combined investigation of solids with Raman [2,3] and SEM-EDX [3] in a combined mode, especially when spatially resolving, holds great potential An investigation with accelerator-based XAS techniques is planned within the framework of the Excellence network Actinet 6. [1] Grigorev, M., Bessonov, A., Makarenkov, V., Fedoseev, A., Model of the (PuO 2 ) 2 SiO 4 * 2H 2 O crystal structure, based on powder X-ray diffraction data, Radiochemistry, Vol. 45, No 3 (2003) 257-260. [2] M. Amme, B. Renker, B. Schmid, M. Feth, H

  4. Appraisal of hard rock for potential underground repositories of radioactive wastes. LBL-7004

    International Nuclear Information System (INIS)

    Cook, N.G.W.

    1978-01-01

    Underground burial of radioactive wastes in hard rock may be an effective and safe means of isolating them from the environment and from man. The mechanical safety and stability of such an underground repository depends largely on the virgin state of stress in the rock, groundwater pressures, the strengths of the rocks, heating by the decay of the radioactive wastes, and the layout of the excavations and the disposition of waste cannisters within them. A large body of pertinent data exists in the literature, and each of these factors has been analyzed in the light of this information. The results indicate that there are no fundamental geological nor mechanical reasons why repositories capable of storing radioactive wastes should not be excavated at suitable sites in hard rock. However, specific tests to determine the mechanical and thermal properties of the rocks at a site would be needed to provide the data for the engineering design of a repository. Also, little experience exists of the effects on underground excavations of thermal loads, so that this aspect requires theoretical study and experimental validation. The depths of these potential repositories would lie in the range from 0.5 km to 2.0 km below surface, depending upon the strength of the rock. Virgin states of stress have been measured at such depths which would retard the ingress of groundwater and obviate the incidence of faulting. A typical repository comprising three horizons each with a total area of 5 km 2 would have the capacity to store wastes with thermal output of 240 MW

  5. The stability of candidate buffer materials for a low-level radioactive waste repository

    International Nuclear Information System (INIS)

    Torok, J.; Buckley, L.P.; Burton, G.R.; Tosello, N.B.; Maves, S.R.; Blimkie, M.E.; Donaldson, J.R.

    1989-11-01

    Inorganic ion-exchangers, clinoptilolite and clay, will be placed on the floor of a low-level radioactive waste repository to be built at Chalk River Nuclear Laboratories. The stability of these ion-exchange materials for a range of potential chemical environments in the repository was investigated. The leaching of waste forms and concrete and biological activity may create acidic or basic environment. The dissolution mechanisms of the ion exchangers for both acid and alkali conditions were established. Changes in distribution coefficients occurred shortly after the commencement of the treatment and were due to changes in the counter-ion content of the ion exchangers. No evidence was found to suggest gradual selective destruction of exchange sites responsible for the high distribution coefficients observed

  6. Final storage of radioactive waste in Germany. Waste arisings and availability of a repository as seen by an electricity utility

    International Nuclear Information System (INIS)

    Broeskamp, H.; Brammer, K.J.; Graf, R.

    2004-01-01

    The management of waste arising in the operation of nuclear power plants has been taken into account since the beginnings of the peaceful uses of nuclear power in Germany. As early as in 1957, a memorandum of the German Advisory Committee on Atomic Energy contains a reference to the need for safe disposal of radioactive waste. Legislation adopted the suggestion and laid down some provisions on the safe utilization of radioactive materials as early as in the Atomic Energy Act of December 23, 1959. In connection with the nuclear waste management center, the Federal Republic also looked for a suitable site for a repository. After thorough site selection proceedings by the federal government and the state of Lower Saxony, the Lower Saxony state government in 1977 defined Gorleben as the site. The decision has been preceded by a three-stage selection process in which more than 140 sites had been investigated. Exploration of the Gorleben site began in 1979 and was interrupted on October 1, 2000 to clarify conceptual and safety-related doubts of the federal government. The German Federal Ministry for the Environment (BMU) seeks to make a repository (for high-level waste) available in 2030. Technically, it is still possible to commission a repository for waste generating heat at Gorleben after 2025 if the salt dome is found to be suitable after speedy conclusion of the exploration work. Reference is made to foreseeable problem areas. Another project pursued by the federal government is the use of the Konrad mine as a repository for low and medium-level radioactive waste. After well over twenty years, the plans approval decision was made in May 2002 and is at present the subject of litigation. On the basis of the data presented about the expected arisings of waste generating no heat in combination with the possible start of emplacement in Konrad in 2013, detailed results are presented. (orig.) [de

  7. Environmental remediation of high-level nuclear waste in geological repository. Modified computer code creates ultimate benchmark in natural systems

    International Nuclear Information System (INIS)

    Peter, Geoffrey J.

    2011-01-01

    Isolation of high-level nuclear waste in permanent geological repositories has been a major concern for over 30 years due to the migration of dissolved radio nuclides reaching the water table (10,000-year compliance period) as water moves through the repository and the surrounding area. Repositories based on mathematical models allow for long-term geological phenomena and involve many approximations; however, experimental verification of long-term processes is impossible. Countries must determine if geological disposal is adequate for permanent storage. Many countries have extensively studied different aspects of safely confining the highly radioactive waste in an underground repository based on the unique geological composition at their selected repository location. This paper discusses two computer codes developed by various countries to study the coupled thermal, mechanical, and chemical process in these environments, and the migration of radionuclide. Further, this paper presents the results of a case study of the Magma-hydrothermal (MH) computer code, modified by the author, applied to nuclear waste repository analysis. The MH code verified by simulating natural systems thus, creating the ultimate benchmark. This approach based on processes similar to those expected near waste repositories currently occurring in natural systems. (author)

  8. Environmental program planning for the proposed high-level nuclear waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    1987-08-01

    This report was prepared to illustrate the policy and actions that the State of Nevada believe are required to assure that the quality of the environment is adequately considered during the course of the DOE work at the proposed high-level nuclear waste repository at Yucca Mountain. The report describes the DOE environmental program and the studies planned by NWPO to reflect the State's position toward environmental protection. 41 refs., 2 figs., 11 tabs

  9. Low- and intermediate-level waste repository-induced effects

    Energy Technology Data Exchange (ETDEWEB)

    Leupin, O.X.; Marschall, P.; Johnson, L.; Cloet, V.; Schneider, J. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Smith, P. [Safety Assessment Management Ltd, Henley-On-Thames, Oxfordshire (United Kingdom); Savage, D. [Savage Earth Associates Ltd, Bournemouth, Dorset (United Kingdom); Senger, R. [Intera Inc., Ennetbaden (Switzerland)

    2016-10-15

    This status report aims at describing and assessing the interactions of the radioactive waste emplaced in a low- and intermediate level waste (L/ILW) repository with the engineered materials and the Opalinus Clay host rock. The Opalinus Clay has a thickness of about 100 m in the proposed siting regions. Among other things the results are used to steer the RD and D programme of NAGRA. The repository-induced effects considered in this report are of the following broad types: - Thermal effects: i.e. effects arising principally from the heat generated by the waste and the setting of cement. - Rock-mechanical effects: i.e. effects arising from the mechanical disturbance to the rock caused by the excavation of the emplacement caverns and other underground structures. - Hydraulic and gas-related effects: i.e. the effects of repository resaturation and of gas generation, e.g. due to the corrosion of metals within the repository, on the host rock and engineered barriers. - Chemical effects: i.e. chemical interactions between the waste, the engineered materials and the host rock. Deep geological repositories are designed to avoid or mitigate the impact of potentially detrimental repository-induced effects on long-term safety. For the repository under consideration in the present report, an assessment of those repository-induced effects that remain shows that detrimental chemical and mechanical impacts are largely confined to the rock adjacent to the excavations, thermal impacts are minimal and gas effects can be mitigated by appropriate design measures to reduce gas production and provide pathways for gas transport that limit gas pressure build-up (engineered gas transport system, or EGTS). Specific measures that are part of the current reference design are discussed in relation to their significance with respect to repository-induced effects. The disposal system described in this report provides a system of passive barriers with multiple safety functions. The disposal

  10. Low- and intermediate-level waste repository-induced effects

    International Nuclear Information System (INIS)

    Leupin, O.X.; Marschall, P.; Johnson, L.; Cloet, V.; Schneider, J.; Smith, P.; Savage, D.; Senger, R.

    2016-10-01

    This status report aims at describing and assessing the interactions of the radioactive waste emplaced in a low- and intermediate level waste (L/ILW) repository with the engineered materials and the Opalinus Clay host rock. The Opalinus Clay has a thickness of about 100 m in the proposed siting regions. Among other things the results are used to steer the RD and D programme of NAGRA. The repository-induced effects considered in this report are of the following broad types: - Thermal effects: i.e. effects arising principally from the heat generated by the waste and the setting of cement. - Rock-mechanical effects: i.e. effects arising from the mechanical disturbance to the rock caused by the excavation of the emplacement caverns and other underground structures. - Hydraulic and gas-related effects: i.e. the effects of repository resaturation and of gas generation, e.g. due to the corrosion of metals within the repository, on the host rock and engineered barriers. - Chemical effects: i.e. chemical interactions between the waste, the engineered materials and the host rock. Deep geological repositories are designed to avoid or mitigate the impact of potentially detrimental repository-induced effects on long-term safety. For the repository under consideration in the present report, an assessment of those repository-induced effects that remain shows that detrimental chemical and mechanical impacts are largely confined to the rock adjacent to the excavations, thermal impacts are minimal and gas effects can be mitigated by appropriate design measures to reduce gas production and provide pathways for gas transport that limit gas pressure build-up (engineered gas transport system, or EGTS). Specific measures that are part of the current reference design are discussed in relation to their significance with respect to repository-induced effects. The disposal system described in this report provides a system of passive barriers with multiple safety functions. The disposal

  11. A performance assessment review tool for the proposed radioactive waste repository at Yucca Mountain, Nevada, USA

    International Nuclear Information System (INIS)

    Mohanty, Sitakanta; Codell, Richard

    2000-01-01

    The U.S. Nuclear Regulatory Commission (NRC), with the assistance of the Center for Nuclear Waste Regulatory Analyses, has developed a Total-system Performance Assessment (TPA) Code to assist in evaluating the performance of the Yucca Mountain (YM) High-Level Waste Repository in Nevada, proposed by the U.S. Department of Energy (DOE). The proposed YM repository would be built in a thick sequence of partially saturated volcanic tuff above the water table. Among the unique challenges of this environment are (1) the transport of radionuclides would take place partially through highly heterogeneous unsaturated rock; (2) the waste packages (WPs) would be generally exposed to oxidizing conditions, and (3) water either infiltrating from the surface or recirculating because of decay heat may drip onto the WPs. Tools such as the TPA code and embedded techniques for evaluating YM performance are aimed at (1) determining the parameters and key parts of the repository system that have the most influence on repository performance; (2) performing alternative conceptual models studies, especially with bounding models; (3) estimating the relative importance of the physical phenomena that lead to human exposure to radionuclides; and (4) improving NRC staff capabilities in performance assessment and associated license application reviews. This paper presents an overview of the NRC conceptual framework, approach to conducting system-level sensitivity analyses for determining influential parameters, and alternative conceptual model studies to investigate the effect of model uncertainties. (author)

  12. Future extension of the Swedish repository for low and intermediate level waste (SFR)

    International Nuclear Information System (INIS)

    Carlsson, Jan

    2006-01-01

    The existing Swedish repository for low and intermediate level waste (SFR) is licensed for disposal of short-lived waste originated from operation and maintenance of Swedish nuclear power plants. The repository is foreseen to be extended to accommodate short-lived waste from the future decommissioning of the Nuclear Power Plants. Long-lived waste from operation, maintenance and eventually decommissioning will be stored some years before disposal in a geological repository. This repository can be build either as a further extension of the SFR facility or as a separate repository. This paper discusses the strategy of a step-wise extended repository where the extensions are performed during operation of the existing parts of the repository. It describes the process for licensing new parts of the repository (and re-license of the existing parts). (author)

  13. Review of durability of cementitious engineered barriers in repository environments

    International Nuclear Information System (INIS)

    Parrott, L.J.; Lawrence, C.D.

    1992-01-01

    This report is concerned with the durability of cementitious engineered barriers in a repository for low and intermediate level nuclear waste. Following the introduction the second section of the review identifies the environmental conditions associated with a deep, hard rock repository for ILW and LLW that are relevant to the durability of cementitious barriers. Section three examines the microstructure and macrostructure of cementitious materials and considers the physical and chemical processes of radionuclide immobilization. Potential repository applications and compositions of cementitious materials are reviewed in Section four. The main analysis of durability is dealt with in Section five. The different types of cementitious barrier are considered separately and their most probable modes of degradation are analysed. Concluding remarks that highlight critical technical matters are given in Section six. (author)

  14. Corrosion of the copper canister in the repository environment

    Energy Technology Data Exchange (ETDEWEB)

    Hermansson, H.P.; Eriksson, Sture [Studsvik Material AB, Nykoeping (Sweden)

    1999-12-01

    The present report accounts for studies on copper corrosion performed at Studsvik Material AB during 1997-1999 on commission by SKI. The work has been focused on localised corrosion and electrochemistry of copper in the repository environment. The current theory of localised copper corrosion is not consistent with recent practical experiences. It is therefore desired to complete and develop the theory based on knowledge about the repository environment and evaluations of previous as well as recent experimental and field results. The work has therefore comprised a thorough compilation and up-date of literature on copper corrosion and on the repository environment. A selection of a 'working environment', defining the chemical parameters and their ranges of variation has been made and is used as a fundament for the experimental part of the work. Experiments have then been performed on the long-range electrochemical behaviour of copper in selected environments simulating the repository. Another part of the work has been to further develop knowledge about the thermodynamic limits for corrosion in the repository environment. Some of the thermodynamic work is integrated here. Especially thermodynamics for the system Cu-Cl-H-O up to 150 deg C and high chloride concentrations are outlined. However, there is also a rough overview of the whole system Cu-Fe-Cl-S-C-H-O as a fundament for the discussion. Data are normally accounted as Pourbaix diagrams. Some of the conclusions are that general corrosion on copper will probably not be of significant importance in the repository as far as transportation rates are low. However, if such rates were high, general corrosion could be disastrous, as there is no passivation of copper in the highly saline environment. The claim on knowledge of different kinds of localised corrosion and pitting is high, as pitting damages can shorten the lifetime of a canister dramatically. Normal pitting can happen in oxidising environment, but

  15. Corrosion of the copper canister in the repository environment

    International Nuclear Information System (INIS)

    Hermansson, H.P.; Eriksson, Sture

    1999-12-01

    The present report accounts for studies on copper corrosion performed at Studsvik Material AB during 1997-1999 on commission by SKI. The work has been focused on localised corrosion and electrochemistry of copper in the repository environment. The current theory of localised copper corrosion is not consistent with recent practical experiences. It is therefore desired to complete and develop the theory based on knowledge about the repository environment and evaluations of previous as well as recent experimental and field results. The work has therefore comprised a thorough compilation and up-date of literature on copper corrosion and on the repository environment. A selection of a 'working environment', defining the chemical parameters and their ranges of variation has been made and is used as a fundament for the experimental part of the work. Experiments have then been performed on the long-range electrochemical behaviour of copper in selected environments simulating the repository. Another part of the work has been to further develop knowledge about the thermodynamic limits for corrosion in the repository environment. Some of the thermodynamic work is integrated here. Especially thermodynamics for the system Cu-Cl-H-O up to 150 deg C and high chloride concentrations are outlined. However, there is also a rough overview of the whole system Cu-Fe-Cl-S-C-H-O as a fundament for the discussion. Data are normally accounted as Pourbaix diagrams. Some of the conclusions are that general corrosion on copper will probably not be of significant importance in the repository as far as transportation rates are low. However, if such rates were high, general corrosion could be disastrous, as there is no passivation of copper in the highly saline environment. The claim on knowledge of different kinds of localised corrosion and pitting is high, as pitting damages can shorten the lifetime of a canister dramatically. Normal pitting can happen in oxidising environment, but there is

  16. Repository sealing concepts for the Nevada nuclear waste storage Investigations Project

    International Nuclear Information System (INIS)

    Fernandez, J.A.; Freshley, M.D.

    1984-08-01

    This report describes concepts for sealing a nuclear waste repository in an unsaturated tuff environment. The repository site under consideration is Yucca Mountain, which is on and adjacent to the Nevada Test Site. The hydrogeology of Yucca Mountain, preliminary repository concepts, functional requirements and performance criteria for sealing, federal and state regulations, and hydrological calculations are considered in developing the sealing concepts. Water flow through the unsaturated zone is expected to be small and generally vertically downward with some potential to occur through discrete fault and fracture zones. These assumptions are used in developing sealing concepts for shafts, ramps, and boreholes. Sealing of discrete, water-producing faults and fracture zones encountered in horizontal emplacement holes and in access and emplacement drifts is also described. 49 references, 21 figures, 6 tables

  17. Scientific, institutional, regulatory, political, and public acceptance of the waste isolation pilot plant transuranic waste repository

    International Nuclear Information System (INIS)

    Eriksson, L.G.

    2000-01-01

    The recent successful certification and opening of a first-of-a-kind, deep geological repository for safe disposal of long-lived, transuranic radioactive waste (TRUW) at the Waste Isolation Pilot Plant (WIPP) site, New Mexico, United States of America (USA), embody both long-standing local and wide-spread, gradually achieved, scientific, institutional, regulatory, political, and public acceptance. The related historical background and development are outlined and the main contributors to the successful siting, certification, and acceptance of the WIPP TRUW repository, which may also serve as a model to success for other radioactive waste disposal programs, are described. (author)

  18. Is Croatia Going to Build a Radioactive Waste Repository?

    International Nuclear Information System (INIS)

    Knapp, Alemka; Levanat, Ivica; Saponja-Milutinovc, Diana

    2014-01-01

    Site selection process for low and intermediate level radioactive waste repository in Croatia was ended in 1999, nominating Trgovska gora as the potential macrolocation for the facility. Feasibility of the Trgovska gora disposal project was analyzed in a number of studies prepared by APO Ltd. from the mid-nineties up to 2003. An affirmative, though preliminary and largely generic safety assessment was completed. Specific microlocations were selected and analyzed based on literature data (garnished with low-resolution digital satellite pictures), and the best microlocation was tentatively narrowed down to Pavlovo brdo. After 2003, no further activities related to the repository project were undertaken for nearly ten years, until in its public procurement plan for 2013 the Croatian Fund for financing the NPP Krsko decommissioning and waste disposal dedicated over half a million euro to continuation of the project. In general, safe radioactive waste disposal pre-requires establishment of a complex national framework with appropriate functionality and competence; with such a framework established, decisive first steps towards building a repository are to identify potentially suitable locations and to ensure local community consent and cooperation. The rest should mainly be routine. But in Croatia, both lack of proper framework and the project history of indecisiveness may adversely affect further developments. Trgovska gora was designated as the potential location in the national land use plan only after three other potential locations had been dismissed by political decisions based on the largely assumed adverse attitudes of local communities. Repository project now appears to depend on cooperation of a single local community hosting the only potential site. The site has never been visited by any repository project participants, nor has the local community ever been officially contacted in an open and straightforward way, despite the 20-year old history of the project

  19. Extraction and characterisation of colloids in waste repository leachate

    International Nuclear Information System (INIS)

    Verrall, K.E.

    1998-10-01

    Inorganic colloids are ubiquitous in environmental waters and are thought to be potential transporters of radionuclides and other toxic metals. Colloids present large surface areas to pollutants and contaminants present in waters and are therefore capable of sorbing and transporting them via groundwater and surface water movement. Much research has been and is currently being undertaken to understand more fully the stability of colloids in different water chemistries, factors which affect metal sorption onto colloids, and the processes which affect metal-colloid transport. This thesis first investigates groundwater and surface water sampling and characterisation techniques for the investigation of the colloids present in and around a low-level waste repository. Samples were collected anaerobically using micro-purge low-flow methodology (MPLF) and then subjected to sequential ultrafiltration, again anaerobically. After separation into size fractions the solids were analysed for radiochemical content, colloid population and morphology. It was found that colloids were present in large numbers in the groundwaters extracted from the trench waste burial area (anaerobic environment), but in the surface drain waters (aerobic environment) colloid population was comparable to levels found in waters extracted from above the trenches. There was evidence that the non-tritium activity was associated with the colloids and particulates in the trenches, but outside of the trenches the evidence was not conclusive because the activity and colloid concentrations were low. Secondly this thesis investigates the stability of inorganic colloids, mainly haematite, in the presence of humic acid, varying pH and electrolyte concentrations. The applicability of the SchuIze-Hardy rule to haematite and haematite/humic acid mixtures was investigated using photon correlation spectroscopy to measure the rate of fast and slow coagulation after the addition of mono, di and trivalent ions. It was

  20. Supply-side approach to nuclear waste repositories

    International Nuclear Information System (INIS)

    Harmon, L.H.

    1985-01-01

    The Nuclear Waste Policy Act of 1982 (NWPA) was signed into law on January 7, 1983. Its purpose was to provide for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel, to establish a program of research, development, and demonstration regarding the disposal of high-level radioactive waste and spent nuclear fuel, and for other purposes. Its goal is to have the first waste repository operational by 1998. It is believed by many that this goal cannot possibly be met. The Act is exceedingly complex with something in it for everybody. There are serious impediments to the program - not the least of which is legislation itself. The process will cost tens of billions of dollars and, even if it does succeed, will take many years to accomplish. This paper proposes a method for getting there in 7 years while saving billions of dollars. It is a summary of a more extensive research effort by the author while attending the Industrial College of the Armed Forces

  1. Safety assessment methodology for waste repositories in deep geological formations

    International Nuclear Information System (INIS)

    Chapuis, A.M.; Lewi, J.; Pradel, J.; Queniart, D.; Raimbault, P.; Assouline, M.

    1986-06-01

    The long term safety of a nuclear waste repository relies on the evaluation of the doses which could be transferred to man in the future. This implies a detailed knowledge of the medium where the waste will be confined, the identification of the basic phenomena which govern the migration of the radionuclides and the investigation of all possible scenarios that may affect the integrity of the barriers between the waste and the biosphere. Inside the Institute of protection and nuclear safety of the French Atomic Energy Commission (CEA/IPSN), the Department of the Safety Analysis (DAS) is currently developing a methodology for assessing the safety of future geological waste repositories, and is in charge of the modelling development, while the Department of Technical Protection (DPT) is in charge of the geological experimental studies. Both aspects of this program are presented. The methodology for risk assessment stresses the needs for coordination between data acquisition and model development which should result in the obtention of an efficient tool for safety evaluation. Progress needs to be made in source and geosphere modelling. Much more sophisticated models could be used than the ones which is described; however sensitivity analysis will determine the level of sophistication which is necessary to implement. Participation to international validation programs are also very important for gaining confidence in the approaches which have been chosen

  2. Screening methodology for site selection of a nuclear waste repository in shale formations in Germany

    International Nuclear Information System (INIS)

    Hoth, P.; Krull, P.; Wirth, H.

    2004-01-01

    The radioactive waste disposal policy in the Federal Republic of Germany is based on the principle that all types of radioactive waste must be disposed of in deep geological formations. Because of the favourable properties of rock salt and the existence of thick rock salt formations in Germany, so far most of the research in the field of radioactive waste disposal sites was focused on the study of the use of rock salt. In addition, German research organisations have also conducted generic research and development projects in alternative geological formations (Wanner and Brauer, 2001), but a comprehensive evaluation of their utilisation has been only done for parts of the crystalline rocks in Germany. Research projects on argillaceous rocks started relatively late, so that German experience is mainly connected to German research work with the corresponding European Underground Research Laboratories and the exploration of the former Konrad iron mine as a potential repository site for radioactive waste with negligible heat generation. The German Federal Government has signed in 2001 an agreement with national utility companies to end electricity generation by nuclear power. This decision affected the entire German radioactive waste isolation strategy and especially the repository projects. The utility companies agreed upon standstill of exploration at the Gorleben site and the Federal Ministry for the Environment tries to establish a new comprehensive procedure for the selection of a repository site, built upon well-founded criteria incorporating public participation. Step 3 of the planning includes the examination of further sites in Germany and the comparison with existing sites and concepts. Under these circumstances, argillaceous rock (clay and shale) formations are now a special area of interest in Germany and the development of a screening methodology was required for the evaluation of shales as host and barrier rocks for nuclear waste repositories. (author)

  3. Waste-rock interactions in the immediate repository

    International Nuclear Information System (INIS)

    McCarthy, G.J.

    1977-01-01

    The high level wastes (HLW's) to be placed underground in rock formations will contain significant amounts of radioactive decay heat for the first hundred-or-so years of isolation. Several physical-chemical changes analogous to natural geochemical processes can occur during this ''thermal period.'' The waste canister can act as a heat source and cause changes in the mineralogy and properties of the surrounding rocks. Geochemically, this is ''contact metamorphism.'' In the event that the canister is corroded and breached, chemical reactions can occur between the HLW, the surrounding rock and possibly the remains of the canister. In a dry repository which has not been backfilled (and thus pressurized) these interactions could be slow at best and with rates decreasing rapidly as the HLW cools. However, significant interactions can occur in years, months or even days under hydrothermal conditions. These conditions could be created by the combination of HLW heat, overburden pressure and water mobilized from the rocks or derived from groundwater intrusion. At the end of the thermal period these interaction products would constitute the actual HLW form (or ''source term'') subject to the low temperature leaching and migration processes under investigation in other laboratories. It is quite possible that these interaction product waste forms will have superior properties compared to the original HLW. Experimental programs initiated at Penn State during the last year aim at determining the nature of any chemical or mineralogical changes in, or interactions between, HLW solids and host rocks under various repository ambients. The accompanying figures describe the simulated HLW forms and the experimental approach and techniques. Studies with basalts as the repository rock are supported by Rockwell Hanford Operations and with shales by the Office of Waste Isolation

  4. Use of virtual reality for the development of a nuclear waste repository for training

    International Nuclear Information System (INIS)

    Avellar, Ricardo Fernandes de; Mól, Antônio Carlos A.; Machado, Daniel Mol; Santo, André Cotelli do E.; Legey, Ana Paula

    2017-01-01

    In Brazil the highest amount of waste generated is low and medium level of radiation. Its management and final destination is important for society and the solution, proposed by the government, involves the construction of a National Repository for Radioactive Waste. Using Virtual Reality (VR), this article aims to develop an interactive virtual model of the repository to assist in the study, evaluation, training of personnel and planning of the installation to be implemented. The method was divided into four steps. The first, called 'Requirements Specification and Survey', aimed at acquiring information about the terrain and future buildings of the installation in the real world. The next step, known as 'Modeling the Environment' is the construction of the virtual environment itself according to the specifications of the previous method. The third, called 'Functionality Implementation' consists of inserting functionalities into the system, such as performing some tasks present in the repository. Finally, the last step is the interactive virtual model of the national repository for radioactive waste, with this tool users can study, evaluate and train conditions/situations of the installation. In conclusion, the results have shown that the tool presented in this work is a possible application of the VR for dissemination and training in nuclear installations. Using this tool, users can visualize and plan strategies to be carried out in a repository, without interrupting the operation of the installation. It can be used for training and operations simulations, aiming to improve the processes without exposing the operators to the radiation. (author)

  5. Use of virtual reality for the development of a nuclear waste repository for training

    Energy Technology Data Exchange (ETDEWEB)

    Avellar, Ricardo Fernandes de; Mól, Antônio Carlos A.; Machado, Daniel Mol, E-mail: ricardo.arq2017@gmail.com, E-mail: mol@ien.gov.br, E-mail: machado.mol@gmail.com [Instituto de Engenharia Nuclear (IEN/CNEN-RJ), Rio de Janeiro, RJ (Brazil); Santo, André Cotelli do E.; Legey, Ana Paula, E-mail: cotelli.andre@gmail.com [Centro Universitário Carioca (UniCarioca), Rio de Janeiro, RJ (Brazil)

    2017-07-01

    In Brazil the highest amount of waste generated is low and medium level of radiation. Its management and final destination is important for society and the solution, proposed by the government, involves the construction of a National Repository for Radioactive Waste. Using Virtual Reality (VR), this article aims to develop an interactive virtual model of the repository to assist in the study, evaluation, training of personnel and planning of the installation to be implemented. The method was divided into four steps. The first, called 'Requirements Specification and Survey', aimed at acquiring information about the terrain and future buildings of the installation in the real world. The next step, known as 'Modeling the Environment' is the construction of the virtual environment itself according to the specifications of the previous method. The third, called 'Functionality Implementation' consists of inserting functionalities into the system, such as performing some tasks present in the repository. Finally, the last step is the interactive virtual model of the national repository for radioactive waste, with this tool users can study, evaluate and train conditions/situations of the installation. In conclusion, the results have shown that the tool presented in this work is a possible application of the VR for dissemination and training in nuclear installations. Using this tool, users can visualize and plan strategies to be carried out in a repository, without interrupting the operation of the installation. It can be used for training and operations simulations, aiming to improve the processes without exposing the operators to the radiation. (author)

  6. Update on the national low level radioactive waste repository study

    International Nuclear Information System (INIS)

    Veitch, S.M.

    1997-01-01

    Activity to establish a national repository for low-level and short-lived intermediate-level radioactive waste in Australia began in the early 1980's. From the early 1990's computer-based geographic information systems had developed sufficiently so that all of Australia could be quickly reviewed using digital data relevant to site selection criteria. A three-phased approach to site selection was commenced which included an iterative process of data collection, interpretation, and public involvement through discussion papers. All of Australia was reviewed using national-scale data, and eight broad regions were identified and reviewed using regional-scale data. A third phase report will be released shortly which includes details on the process for identifying the preferred region of the eight. This region will be the focus for public involvement and for detailed study to identify a site for the national repository

  7. The study on safety facility criteria for radioactive waste repository

    International Nuclear Information System (INIS)

    Lee, S. H.; Choi, M. H.; Han, S. H. and others

    1992-12-01

    The radioactive waste repository are necessary to install the engineered safety systems to secure the safety for operation of the repository in the event of fire and earthquake. Since the development of safety facility criteria requires a thorough understanding about the characteristics of the engineered safety systems, we should investigate by means of literature survey and visit SKB. In particular, definition, composition of the systems, functional requirement of the systems, engineered safety systems of foreign countries, system design, operation and maintenance requirement should be investigated : fire protection system, ventilation system, drainage system, I and C system, electric system, radiation monitoring system. This proposed criteria consist of purpose, scope of application, ventilation system, fire protection system, drainage system, electric system and this proposed criteria can be applied as a basic reference for the final criteria

  8. Colloids in the mortar backfill of a cementitious repository for radioactive waste

    International Nuclear Information System (INIS)

    Wieland, E.; Spieler, P.

    1999-01-01

    Colloids are present in groundwater aquifers and water-permeable engineered barrier systems and may facilitate the migration of radionuclides. A careful evaluation of colloid concentrations is required to assess the potential effect of colloids on nuclide migration and, consequently, on the safety of a repository for radioactive waste. A highly permeable mortar is foreseen to be used as backfill for the engineered barrier of the Swiss repository for low- and intermediate-level waste (L/ILW). The backfill is considered to be a chemical environment with a potential for colloid generation and, due to its high porosity, for colloid mobility. In this contribution a novel in-house built particle counting device is described, and measurements of colloid concentrations in the pore water of backfill mortar are presented. (author)

  9. Mathematical simulation for safety assessment of nuclear waste repositories

    International Nuclear Information System (INIS)

    Brandstetter, A.; Raymond, J.R.; Benson, G.L.

    1979-01-01

    Mathematical models are being developed as part of the Waste Isolation Safety Assessment Program (WISAP) for assessing the post-closure safety of nuclear waste storage in geologic formations. The objective of this program is to develop the methods and data necessary to determine potential events that might disrupt the integrity of a waste repository and provide pathways for radionuclides to reach the bioshpere, primarily through groundwater transport. Four categories of mathematical models are being developed to assist in the analysis of potential release scenarios and consequences: (1) release scenario analysis models; (2) groundwater flow models; (3) contaminant transport models; and (4) radiation dose models. The development of the release scenario models is in a preliminary stage; the last three categories of models are fully operational. The release scenario models determine the bounds of potential future hydrogeologic changes, including potentially disruptive events. The groundwater flow and contaminant transport models compute the flowpaths, travel times, and concentrations of radionuclides that might migrate from a repository in the event of a breach and potentially reach the biosphere. The dose models compute the radiation doses to future populations. Reference site analyses are in progress to test the models for application to different geologies, including salt domes, bedded salt, and basalt

  10. Qualifying concrete for a low-level waste repository

    International Nuclear Information System (INIS)

    Philipose, K.E.

    1990-06-01

    A waste repository for the belowground disposal of low-level radioactive waste, labelled IRUS (Intrusion Resistant Underground Structure), is planned at Chalk River Nuclear Laboratories. It relies greatly on the durability of concrete for a minimum of 500 years of service life. A research program based on laboratory testing to design a durable concrete and predict its useful engineered service life is in progress. Durability of concrete depends on its resistance of deterioration from both internal and external causes. Since the rate of degradation depends to a major extent on the rate of ingress of aggressive ions into concrete, laboratory testing is in progress to establish the diffusion rates of ions, especially chlorides, sulphate and carbonate ions. A total of 1000 concrete specimens and 500 paste specimens are being exposed at 22 and 45 degrees C to twenty-five different combinations of corrosive agents, including CO 2 . Procedures to measure the ionic profile and to determine the factors controlling diffusion of ions in the various concretes have been developed. The paper presents the initial results from the research program and the longevity predictions to qualify concretes for the IRUS waste repository, based on twelve months of diffusion testing on laboratory specimens

  11. Reassessment of the Goiânia radioactive waste repository in Brazil using HYDRUS-1D

    Directory of Open Access Journals (Sweden)

    Pontedeiro Elizabeth M.

    2018-06-01

    Full Text Available In September 1987 an accident occurred with a cesium chloride (CsCl teletherapy source taken from a cancer therapy institute in Goiânia, Brazil. Misuse of the abandoned source caused widespread contamination of radioactive material (about 50 TBq of 137Cs in the town of Goiânia. Decontamination of affected areas did lead to about 3,500 m3 of solid radioactive wastes, which were disposed in two near-surface repositories built in concrete in 1995. This paper documents a safety assessment of one of the low-level radioactive waste deposits containing 137Cs over a time period of 600 years. Using HYDRUS-1D, we first obtained estimates of water infiltrating through the soil cover on top of the repository into and through the waste and its concrete liners and the underlying vadose zone towards groundwater. Calculations accounted for local precipitation and evapotranspiration rates, including root water uptake by the grass cover, as well as for the effects of concrete degradation on the hydraulic properties of the concrete liners. We next simulated long-term water fluxes and 137Cs transport from the repository towards groundwater. Simulations accounted for the effects of 137Cs sorption and radioactive decay on radionuclide transport from the waste to groundwater, thus permitting an evaluation of potential consequences to the environment and long-term exposure to the public. Consistent with previous assessments, our calculations indicate that very little if any radioactive material will reach the water table during the lifespan of the repository, also when accounting for preferential flow through the waste.

  12. Economic implications of locating a nuclear waste repository in Texas. Hearing before the Subcommittee on Nuclear Regulation of the Committee on Environment and Public Works, United States Senate, Ninety-Ninth Congress, First Session, February 11, 1985, Hereford, TX

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Ten witnesses representing Texas industries and agriculture spoke at a field hearing in Hereford, Texas on the selection of Deaf Smith County as one of the three potential repository sites for spent fuel and high-level radioactive wastes. Safety and the potential for ground water contamination were major arguments of the opponents to the location. DOE spokesman William Purcell advised that no material will be placed in the repository until the turn of the century and then after a lengthy public licensing procedure. Other concerns were the socio-economic impacts on the surrounding area and the possible damage to agriculture if either soil or water contamination should occur. Additional statements submitted for the record follow the testimony

  13. Analysis of the geological stability of a hypothetical radioactive waste repository in a bedded salt formation

    International Nuclear Information System (INIS)

    Tierney, M.S.; Lusso, F.; Shaw, H.R.

    1978-01-01

    This document reports on the development of mathematical models used in preliminary studies of the long-term safety of radioactive wastes deeply buried in bedded salt formations. Two analytical approaches to estimating the geological stability of a waste repository in bedded salt are described: (a) use of probabilistic models to estimate the a priori likelihoods of release of radionuclides from the repository through certain idealized natural and anthropogenic causes, and (b) a numerical simulation of certain feedback effects of emplacement of waste materials upon ground-water access to the repository's host rocks. These models are applied to an idealized waste repository for the sake of illustration

  14. Analysis on one underground nuclear waste repository rock mass in USA

    International Nuclear Information System (INIS)

    Ha Qiuling; Zhang Tiantian

    2012-01-01

    When analyzing the rock mass of a underground nuclear waste repository, the current studies are all based on the loading mechanical condition, and the unloading damage of rock mass is unconsidered. According to the different mechanical condition of actual engineering rock mass of loading and unloading, this paper implements a comprehensive analysis on the rock mass deformation of underground nuclear waste repository through the combination of present loading and unloading rock mass mechanics. It is found that the results of comprehensive analysis and actual measured data on the rock mass deformation of underground nuclear waste repository are basically the same, which provide supporting data for the underground nuclear waste repository. (authors)

  15. The waste isolation pilot plant transuranic waste repository: A case study in radioactive waste disposal safety and risk

    Energy Technology Data Exchange (ETDEWEB)

    Eriksson, Leif G. [GRAM, Inc., Albuquerque, NM (United States)

    1999-12-01

    The Waste Isolation Pilot Plant (WIPP) deep geological defense-generated transuranic radioactive waste (TRUW) repository in the United States was certified on the 13 of May 1998 and opened on the 26 of March 1999. Two sets of safety/performance assessment calculations supporting the certification of the WIPP TRUW repository show that the maximum annual individual committed effective dose will be 32 times lower than the regulatory limit and that the cumulative amount of radionuclide releases will be at least 10 times, more likely at least 20 times, lower than the regulatory limits. Yet, perceptions remain among the public that the WIPP TRUW repository imposes an unacceptable risk.

  16. The waste isolation pilot plant transuranic waste repository: A case study in radioactive waste disposal safety and risk

    International Nuclear Information System (INIS)

    Eriksson, Leif G.

    1999-01-01

    The Waste Isolation Pilot Plant (WIPP) deep geological defense-generated transuranic radioactive waste (TRUW) repository in the United States was certified on the 13 of May 1998 and opened on the 26 of March 1999. Two sets of safety/performance assessment calculations supporting the certification of the WIPP TRUW repository show that the maximum annual individual committed effective dose will be 32 times lower than the regulatory limit and that the cumulative amount of radionuclide releases will be at least 10 times, more likely at least 20 times, lower than the regulatory limits. Yet, perceptions remain among the public that the WIPP TRUW repository imposes an unacceptable risk

  17. Social impact mitigation and nuclear waste repository siting

    International Nuclear Information System (INIS)

    Peelle, E.

    1980-01-01

    Some aspects of the socioeconomic impacts of siting, constructing, and operating radioactive waste repositories in rural areas are discussed. These include public perceptions of high risk and uncertainty; limited benefits and no incentives; dissociations of costs and benefits; remoteness and inaccessibility of the decision making process for large energy facilities; no institutions to provide protection and accountability for those who may be affected by the siting; the fact that not all risks or impacts are fully mitigable; and constraints on DOE's present ability or authority to mitigate impacts

  18. Geoprospective study of radioactive waste repositories applied to a paleosite

    International Nuclear Information System (INIS)

    Filippi, C.; Fourniguet, J.; Godefroy, P.; Manigault, B.; Peaudecerf, P.

    1987-01-01

    The aim of this research is to valid the geoprospective approach elaborated previously in the framework of contracts with Commission of European Communities. The geoprospective approach is applied to a ''paleosite'' i.e. to a region the evolution of which can be reconstructed for the last 100.000 years. This work is performed on a part of Parisian Basin near the English Channel coast. It allows to simulate the combined effects of sea and river level variations, and tectonic activity. All these factors taken in a rather severe context, would not have changed significantly, the confining conditions of the geological barrier around a radioactive waste repository

  19. Uncertainty management in radioactive waste repository site assessment

    International Nuclear Information System (INIS)

    Baldwin, J.f.; Martin, T.P.; Tocatlidou

    1994-01-01

    The problem of performance assessment of a site to serve as a repository for the final disposal of radioactive waste involves different types of uncertainties. Their main sources include the large temporal and spatial considerations over which safety of the system has to be ensured, our inability to completely understand and describe a very complex structure such as the repository system, lack of precision in the measured information etc. These issues underlie most of the problems faced when rigid probabilistic approaches are used. Nevertheless a framework is needed, that would allow for an optimal aggregation of the available knowledge and an efficient management of the various types of uncertainty involved. In this work a knowledge-based modelling of the repository selection process is proposed that through a consequence analysis, evaluates the potential impact that hypothetical scenarios will have on a candidate site. The model is organised around a hierarchical structure, relating the scenarios with the possible events and processes that characterise them, and the site parameters. The scheme provides for both crisp and fuzzy parameter values and uses fuzzy semantic unification and evidential support logic reference mechanisms. It is implemented using the artificial intelligence language FRIL and the interaction with the user is performed through a windows interface

  20. Computer enhanced release scenario analysis for a nuclear waste repository

    International Nuclear Information System (INIS)

    Stottlemyre, J.A.; Petrie, G.M.; Mullen, M.F.

    1979-01-01

    An interactive (user-oriented) computer tool is being developed at PNL to assist in the analysis of release scenarios for long-term safety assessment of a continental geologic nuclear waste repository. Emphasis is on characterizing the various ways the geologic and hydrologic system surrounding a repository might vary over the 10 6 to 10 7 years subsequent to final closure of the cavern. The potential disruptive phenomena are categorized as natural geologic and man-caused and tend to be synergistic in nature. The computer tool is designed to permit simulation of the system response as a function of the ongoing disruptive phenomena and time. It is designed to be operated in a determinatic manner, i.e., user selection of the desired scenarios and associated rate, magnitude, and lag time data; or in a stochastic mode. The stochastic mode involves establishing distributions for individual phenomena occurrence probabilities, rates, magnitudes, and phase relationships. A Monte-Carlo technique is then employed to generate a multitude of disruptive event scenarios, scan for breaches of the repository isolation, and develop input to the release consequence analysis task. To date, only a simplified one-dimensional version of the code has been completed. Significant modification and development is required to expand its dimensionality and apply the tool to any specific site

  1. Radionuclide transport from near-surface repository for radioactive waste - The unsaturated zone approach

    Energy Technology Data Exchange (ETDEWEB)

    Jakimaviciute-Maseliene, V. [Vilnius University (Lithuania); Mazeika, J. [Nature Research Centre (Lithuania); Motiejunas, S. [Radioactive Waste Management Agency (Lithuania)

    2014-07-01

    About 100 000 m{sup 3} of solid conditioned Low and Intermediate Level Waste (LILW), generated during operation and decommissioning of the Ignalina nuclear power plant (INPP), are to be disposed of in a near-surface repository (NSR) - a 'hill'-type repository with reinforced concrete vaults and with engineered and natural barriers. The northeastern Lithuania and the environment of the INPP in particular were recognized as the areas most suitable for a near-surface repository (Stabatiske Site). The engineered barriers of the repository consist of concrete cells surrounded by clay-based material of low permeability with about the same isolating capacity in all directions. The clay materials must be effectively compactable so that required hydraulic conductivity is reached. The Lithuanian Triassic clay turned out to be sufficiently rich in smectites and was proposed as main candidate for sealing of the repository. When the concrete vaults are filled, the repository cover will be constructed. The surface of the mound will be planted with grass. In this study a computer code FEFLOW 5.0 was applied for simulating the transport of the most mobile radionuclides ({sup 3}H, {sup 14}C, {sup 59}Ni and {sup 94}Nb) with moisture through an unsaturated vault of the near-surface repository in Stabatiske Site. The HYDRUS-1D analysis was used to assess the radionuclide transport in the repository and to estimate initial activity concentrations of radionuclides transported from the cemented waste matrix. Radionuclide release from the vault in the unsaturated conditions after closure of the repository and consequent contaminant plume transport has been assessed taking into account site-specific natural and engineering conditions and based on a normal evolution scenario. The highest peak radionuclide activity concentrations were estimated applying the FEFLOW code. The highest value of {sup 14}C activity concentration(about 1.3x10{sup 8} Bq/m{sup 3}) at the groundwater table

  2. Methodology applied in Cuba for siting, designing, and building a radioactive waste repository under safety conditions

    International Nuclear Information System (INIS)

    Orbera, L.; Peralta, J.L.; Franklin, R.; Gil, R.; Chales, G.; Rodriguez, A.

    1993-01-01

    The work presents the methodology used in Cuba for siting, designing, and building a radioactive waste repository safely. This methodology covers both the technical and socio-economic factors, as well as those of design and construction so as to have a safe siting for this kind of repository under Cuba especial condition. Applying this methodology will results in a safe repository

  3. Stability of a radioactive waste repository in the Canadian shield

    International Nuclear Information System (INIS)

    Mahtab, M.A.; Ratigan, J.L.; McCreath, D.R.

    1977-01-01

    A nonlinear finite element analysis is presented for a radioactive waste repository room assumed to be located at a depth of 1,000 meters in the Canadian Shield. The loading of the finite element model is both due to in situ stresses which exist prior to excavation and thermomechanical stresses arising from the radiogenic heat dissipation of the waste assumed to have a half life of 30 years and a gross thermal loading of 32 watts/m 2 . The influence of in situ stress, joint cohesion and joint friction angle on the isolation room stability and support requirements is examined for a simulated period of 30 years. For the range of in situ stress conditions, properties of the jointed rock mass, and the thermal loading considered, the extent of the rock failure is within the capability of conventional rock support measures

  4. Kriging analysis for a candidate nuclear waste repository

    International Nuclear Information System (INIS)

    Devary, J.L.

    1983-08-01

    An important aspect of ensuring the safety of a geologic nuclear waste repository involves the study of ground-water flow at the proposed site. Geohydrologic site characterization involves the evaluation of potentiometric (head) data from confined aquifers. Geostatistical techniques (kriging) are applied to head measurements from the Permian System, a geologic formation being considered by the Department of Energy for nuclear waste disposal. The kriging analysis investigates the adequacy of the data base, provides methods for data screening, and determines optimal locations for additional data collection. This presentation illustrates the development of a generalized covariance and the production of potentiometric contour maps and error maps. The advantages of kriging over traditional least squares regression analysis are also discussed. 17 references

  5. Bituminous and asphaltic membranes for radioactive waste repositories on land

    International Nuclear Information System (INIS)

    1988-03-01

    The aim of the study has been to identify, within generic designs for waste facilities, areas where bituminous materials might be incorporated as a barrier. The report is presented in three sections: Part I - The properties of bitumen are described, with particular reference to the long-term behaviour of the material. The durability of bitumen is discussed, including aspects such as ageing, microbial degradation, chemical resistance and radiation resistance. Part II -The use of bituminous materials in hydraulic engineering is outlined. Much of this section of the report concentrates on the use of bituminous materials in embankment dams and reservoir construction. A review of material technology and construction techniques is presented and a detailed assessment made of the performance of the materials in service. Part III - Generic trench type radioactive waste repository designs incorporating bituminous materials are presented. Material and construction specifications for the designs are detailed, and a performance assessment presented. (author)

  6. Low and medium level radioactive waste repository: risk perception

    International Nuclear Information System (INIS)

    Aquino, Afonso Rodrigues de; Bueno, Lilian de Oliveira; Vieira, Martha Marques Ferreira; Fonseca, Edvaldo Roberto Paiva da; Bellintani, Sandra Aparecida

    2009-01-01

    This paper focuses on the risk perception associated to the installation of low and intermediate level radioactive waste (LLRW and ILRW) disposal facilities. The purpose is to give support for the implementation of a repository in Brazil. Public acceptance results from a long term work and trust is vital for the process as it takes long to be conquered but might be shortly lost. Therefore, it is essential to care about the way each step is conducted. The knowledge about the system and the risks, the comprehension about these risks, the commitment with safety, adequate support systems for the project (legislation, involved institutions) and the excellence as a goal to be reached are extremely important parameters. The involvement of all interested parties in the decision-making process is condition for a successful and publicly acceptable implementation of such project. The steps for public acceptance of a repository are summarized as follow: Risk perception: to verify how the local population understand and feel the installation of a repository in the region. Media observatory: to continuously follow the news reaching the region where the repository will be installed, including different media. Local population social/economical/cultural profile identification: to determine the local population social/economical/cultural profile; to conduct a survey to know their expectations, allowing the proposal of compensation and incentives to fully account for their expectations. Finally, the philosophy governing this Project is: on doubt, the public must be heard and only after this public hearing the policies concerning the project shall be formulated. (author)

  7. Low and medium level radioactive waste repository: risk perception

    Energy Technology Data Exchange (ETDEWEB)

    Aquino, Afonso Rodrigues de; Bueno, Lilian de Oliveira; Vieira, Martha Marques Ferreira; Fonseca, Edvaldo Roberto Paiva da; Bellintani, Sandra Aparecida [Instituto de Pesquisas Energeticas e Nucleares (IPEN/CNEN-SP), Sao Paulo, SP (Brazil)], e-mail: araquino@ipen.br, e-mail: lbueno@ipen.br, e-mail: mmvieira@ipen.br, e-mail: efonseca@ipen.br, e-mail: sbellint@ipen.br

    2009-07-01

    This paper focuses on the risk perception associated to the installation of low and intermediate level radioactive waste (LLRW and ILRW) disposal facilities. The purpose is to give support for the implementation of a repository in Brazil. Public acceptance results from a long term work and trust is vital for the process as it takes long to be conquered but might be shortly lost. Therefore, it is essential to care about the way each step is conducted. The knowledge about the system and the risks, the comprehension about these risks, the commitment with safety, adequate support systems for the project (legislation, involved institutions) and the excellence as a goal to be reached are extremely important parameters. The involvement of all interested parties in the decision-making process is condition for a successful and publicly acceptable implementation of such project. The steps for public acceptance of a repository are summarized as follow: Risk perception: to verify how the local population understand and feel the installation of a repository in the region. Media observatory: to continuously follow the news reaching the region where the repository will be installed, including different media. Local population social/economical/cultural profile identification: to determine the local population social/economical/cultural profile; to conduct a survey to know their expectations, allowing the proposal of compensation and incentives to fully account for their expectations. Finally, the philosophy governing this Project is: on doubt, the public must be heard and only after this public hearing the policies concerning the project shall be formulated. (author)

  8. Backfill barriers for nuclear waste repositories in salt

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, E J; Odoj, R; Merz, E [eds.

    1981-06-01

    Backfill mixtures surrounding the waste form and canister can provide a neutral or slightly acidic, potentially reducing environment, prevent convective aqueous flow, and act as an effective radionuclide migration barrier. Bentonite is likely to remain hydrothermally stable but potentially sensitive to waste package interactions which could alter the pH, the ratio of dissolved wires, or the sorption properties of radionuclide species.

  9. Nuclear waste repository siting and locational conflict analysis: A contextual approach

    International Nuclear Information System (INIS)

    Murauskas, G.T.

    1989-01-01

    This study develops and evaluates an alternative framework that is based on contextual variables. The premise is that differences in attitudes and perceptions regarding the local siting of nuclear wastes and differences in attitudes regarding siting decision-making procedures are influenced by local political, economic, and cultural variables. This framework articulates the nature of conflict in terms of the incongruence between the use-value individuals ascribe to their present situation and the anticipated exchange-value individuals associate with the local siting of a nuclear waste repository. In order to evaluate this conceptual framework a survey was conducted of residents in four communities representing distinct societal contexts: Richton, Mississippi; Peterborough, New Hampshire; Richland, Washington; and Antigo/Waupaca, Wisconsin. Data analyses indicate substantial differences in economic expectations associated with the local siting of a high-level nuclear waste repository and in perception regarding the impacts such a repository might have on the environment, local agriculture, personal health and safety, and the quality of life

  10. Migration of radionuclides through backfill in a nuclear waste repository

    International Nuclear Information System (INIS)

    Lung, H.

    1986-01-01

    Four models are analyzed to predict the performance of a backfill layer as part of the waste package emplacement in a nuclear waste repository. The corresponding computer code for each model is also developed. The time-dependent mass transfer analysis on a spherical waste-backfill geometry indicates that the radioactive decay effect can enhance the mass transfer rate from the backfill instead of reducing it. The analysis yields the breakthrough time of the backfill layer, which in turn characterizes the backfill performance. A non-linear (Langmuir) sorption isotherm is used to describe the sorption saturation in the backfill. The steady state mass transport analysis through a prolate spheroidal waste-backfill geometry shows that a simple formula can be used to calculate the individual resistances to mass transport in backfill and in host rock. A general, non-recursive analytical solution is derived for a radioactive decay chain of arbitrary length in either a finite or a semi-infinite medium. Numerical examples are given for different boundary conditions and for different decay chains. The results justify that for a backfill layer made of low permeability material, a zero water velocity can be used in the backfill analysis. It is also shown that under normal repository conditions, the mass transfer rate from the backfill is quite small. For the daughter member with a smaller retardation coefficient than that of the mother nuclide, such as 226 Ra in the 234 U → 230 Th → 226 Ra chain, an interior maximum in the concentration profile appears in the backfill. This phenomenon can be seen only in a chain calculation

  11. Progress on the national low level radioactive waste repository and national intermediate level waste store

    International Nuclear Information System (INIS)

    Perkins, C.

    2003-01-01

    The Australian Government is committed to establishing two purpose-built facilities for the management of Australia's radioactive waste; the national repository for disposal of low level and short-lived intermediate level ('low level') waste, and the national store for storage of long-lived intermediate level ('intermediate level') waste. It is strongly in the interests of public security and safety to secure radioactive waste by disposal or storage in facilities specially designed for this purpose. The current arrangements where waste is stored under ad hoc arrangements at hundreds of sites around Australia does not represent international best practice in radioactive waste management. Environmental approval has been obtained for the national repository to be located at Site 40a, 20 km east of Woomera in South Australia, and licences are currently being sought from the Australian Radiation Protection and Nuclear Safety Agency (ARPANSA) to site, construct and operate the facility. The national repository may be operating in 2004 subject to obtaining the required licences. The national store will be located on Australian Government land and house intermediate level waste produced by Australian Government departments and agencies. The national store will not be located in South Australia. Short-listing of potentially suitable sites is expected to be completed soon

  12. Operational procedures for receiving, packaging, emplacing, and retrieving high-level and transuranic waste in a geologic repository in TUFF

    International Nuclear Information System (INIS)

    Dennis, A.W.; Mulkin, R.

    1984-01-01

    The Nevada Nuclear Waste Storage Investigations Project, directed by the Nevada Operations Office of the Department of Energy, is currently developing conceptual designs for a commercial nuclear waste repository. In this paper, the preliminary repository operating plans are identified and the proposed repository waste inventory is discussed. The receipt rates for truck and rail car shipments of waste are determined as are the required repository waste emplacement rates

  13. Hydrogeologic effects of natural disruptive events on nuclear waste repositories

    International Nuclear Information System (INIS)

    Davis, S.N.

    1980-06-01

    Some possible hydrogeologic effects of disruptive events that may affect repositories for nuclear waste are described. A very large number of combinations of natural events can be imagined, but only those events which are judged to be most probable are covered. Waste-induced effects are not considered. The disruptive events discussed above are placed into four geologic settings. Although the geology is not specific to given repository sites that have been considered by other agencies, the geology has been generalized from actual field data and is, therefore, considered to be physically reasonable. The geologic settings considered are: (1) interior salt domes of the Gulf Coast, (2) bedded salt of southeastern New Mexico, (3) argillaceous rocks of southern Nevanda, and (4) granitic stocks of the Basin and Range Province. Log-normal distributions of permeabilities of rock units are given for each region. Chapters are devoted to: poresity and permeability of natural materials, regional flow patterns, disruptive events (faulting, dissolution of rock forming minerals, fracturing from various causes, rapid changes of hydraulic regimen); possible hydrologic effects of disruptive events; and hydraulic fracturing

  14. Estimation of mean time to failure of a near surface radioactive waste repository for PWR power stations

    International Nuclear Information System (INIS)

    Aguiar, Lais A. de; Frutuoso e Melo, P.F.; Alvim, Antonio C.M.

    2007-01-01

    This work aims at estimating the mean time to failure (MTTF) of each barrier of a near surface radioactive waste repository. It is assumed that surface water infiltrates through the barriers, reaching the matrix where radionuclides are contained, releasing them to the environment. Radioactive wastes considered in this work are low and medium level wastes (produced during operation of a PWR nuclear power station) fixed on cement. The repository consists of 6 saturated porous media barriers (top cover, upper layer, packages, basis, repository walls and geosphere). It has been verified that the mean time to failure (MTTF) of each barrier increases for radionuclides having higher retardation factor (Fr) and also that the MTTF for concrete is larger for Nickel , while for the geosphere, Plutonium gives the largest MTTF. (author)

  15. Recommendations: Procedure to develop a preliminary safety report as part of the radioactive waste repository construction licensing process

    International Nuclear Information System (INIS)

    2003-01-01

    The structure of a preliminary safety report for the title purpose should be as follows: A. Textual part: 1. General (Introduction, Basic information about the construction, Timetable); 2. Site information (Siting, Geography and demography, Meteorology and climatic situation, Hydrology, Geology and hydrogeology); 3. Repository design description (Basic function and performance requirements, Design, Auxiliary systems, Fire prevention/protection, Emergency plans); 4. Operation of the repository (Waste acceptance and inspection, Waste handling and interim storage, Waste disposal, Operating monitoring), 5. Health and environmental impact assessment (Radionuclide inventory, Radionuclide transport paths and mechanisms of release into the environment, Radionuclide release in normal and emergency situations, Radiation protection - health impact assessment and regulatory compliance, Draft operating limits and conditions, Proposed ways of assuring physical protection, Uncertainty assessment), 6. Safe repository shutdown/decommissioning concept, 7 Quality assurance assessment, 8. List of selected equipment. B. Annexes: Maps, Drawings, Diagrams, Miscellaneous; C. Documentation: Previous safety report amendments, Protocols, Miscellaneous. (P.A.)

  16. Final repositories for high-level radioactive waste; Endlagerung hochradioaktiver Abfaelle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-10-15

    The brochure on final repositories for high-level radioactive waste covers the following issues: What is the origin of radioactive wastes? How large are the waste amounts? What is going to happen with the wastes? What is the solution for the Waste disposal? A new site search is started. Safety requirements for the final disposal of high-level radioactive wastes. Comparison of host rocks. Who is responsible and who will pay? Final disposal of high-level radioactive wastes worldwide. Short summary: History of the search for a final repository for high-level radioactive wastes in Germany.

  17. The Microbiology of Subsurface, Salt-Based Nuclear Waste Repositories: Using Microbial Ecology, Bioenergetics, and Projected Conditions to Help Predict Microbial Effects on Repository Performance

    International Nuclear Information System (INIS)

    Swanson, Juliet S.; Cherkouk, Andrea; Arnold, Thuro; Meleshyn, Artur; Reed, Donald T.

    2016-01-01

    This report summarizes the potential role of microorganisms in salt-based nuclear waste repositories using available information on the microbial ecology of hypersaline environments, the bioenergetics of survival under high ionic strength conditions, and ''repository microbiology'' related studies. In areas where microbial activity is in question, there may be a need to shift the research focus toward feasibility studies rather than studies that generate actual input for performance assessments. In areas where activity is not necessary to affect performance (e.g., biocolloid transport), repository-relevant data should be generated. Both approaches will lend a realistic perspective to a safety case/performance scenario that will most likely underscore the conservative value of that case.

  18. The Microbiology of Subsurface, Salt-Based Nuclear Waste Repositories: Using Microbial Ecology, Bioenergetics, and Projected Conditions to Help Predict Microbial Effects on Repository Performance

    Energy Technology Data Exchange (ETDEWEB)

    Swanson, Juliet S. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States); Cherkouk, Andrea [Helmholtz-Zentrum Dresden-Rossendorf, Rossendorf (Germany); Arnold, Thuro [Helmholtz-Zentrum Dresden-Rossendorf, Rossendorf (Germany); Meleshyn, Artur [Gesellschaft fur Anlagen und Reaktorsicherheit, Braunschweig (Germany); Reed, Donald T. [Los Alamos National Lab. (LANL), Los Alamos, NM (United States)

    2016-11-17

    This report summarizes the potential role of microorganisms in salt-based nuclear waste repositories using available information on the microbial ecology of hypersaline environments, the bioenergetics of survival under high ionic strength conditions, and “repository microbiology” related studies. In areas where microbial activity is in question, there may be a need to shift the research focus toward feasibility studies rather than studies that generate actual input for performance assessments. In areas where activity is not necessary to affect performance (e.g., biocolloid transport), repository-relevant data should be generated. Both approaches will lend a realistic perspective to a safety case/performance scenario that will most likely underscore the conservative value of that case.

  19. Radioactive wastes repository in Temascalapa, State of Mexico, public opinion. Determination of health effects

    International Nuclear Information System (INIS)

    Solis Tinoco, E.

    1998-01-01

    Nuclear waste usually concerns public about the impact on public health and the environment. In Mexico, such interest exists, particularly in the Temascalapa Municipality, Mexico where a low level waste repository recognized by the IAEA, has been functioning since 1972. Maquixco repository is located at 42 Kilometers northeast of Mexico City. Although the environmental radiological monitoring records have demonstrated negligible impact on the environment, in 1998 an unusual public polemic on radioactive health effects appeared among Temascalapa residents. This paper presents a research performed during 1998 with the participation of the National Nuclear Research Institute of Mexico and the National Autonomous University of Mexico. The research design allowed the involvement of local authorities, as a way of stimulate public participation. The research was performed in nine locations of the Temascalapa Municipality, it was focused on public polemics, associated to Maquixco repository as well as trying to identify demographic factors that exert influence on public attitudes. There are also presented the results of personal dosimetry analysis performed on a four hundred residents sample of this Municipality. (Author)

  20. Technical conservatism in the design and analysis of a nuclear-waste repository in basalt

    International Nuclear Information System (INIS)

    Jones, K.A.

    1982-01-01

    The US Department of Energy's National Waste Terminal Storage Program has adopted a policy of technical conservatism to guide the design and analysis of geologic disposal systems for commercial high-level radioactive waste. Technical conservatism serves as the programmatic philosophy for managing uncertainty in the performance of the disposal system. The implementation of technical conservatism as applied to a nuclear waste repository in basalt is discussed. Preliminary assessments of the performance of the waste package, repository, and site subsystems are compared to key proposed regulatory criteria. The comparison shows that there are substantial safety margins in the predicted performance of the nuclear waste repository in basalt

  1. Whiskers and Localized Corrosion on Copper in Repository Environment

    International Nuclear Information System (INIS)

    Hermansson, Hans-Peter; Gillen, Peter

    2004-03-01

    that there is a localized attack on the metal surface beneath the whisker root. In the small diameter whisker case this attribution is quite clear, but it is less clear for the large diameter case. The results could have an implication on the integrity of the copper lining of the waste canister and possible release of radionuclei to the repository environment. The seriousness of this assumption should be evaluated by a study of the ability of whiskers to grow on copper in a bentonite environment

  2. High-level waste repository-induced effects

    Energy Technology Data Exchange (ETDEWEB)

    Leupin, O.X.; Marschall, P.; Johnson, L.; Cloet, V.; Schneider, J. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Smith, P. [Safety Assessment Management Ltd, Henley-On-Thames, Oxfordshire (United Kingdom); Savage, D. [Savage Earth Associates Ltd, Bournemouth, Dorset (United Kingdom); Senger, R. [Intera Inc., Ennetbaden (Switzerland)

    2016-10-15

    This status report aims at describing and assessing the interactions of the radioactive waste emplaced in a high-level waste (HLW) repository with the engineered materials and the Opalinus Clay host rock. The Opalinus Clay has a thickness of about 100 m in the proposed siting regions. Among other things the results are used to steer the RD and D programme of NAGRA. The repository-induced effects considered in this report are of the following broad types: - Thermal effects: i.e. effects on the host rock and engineered barriers arising principally from the heat generated by the waste. - Rock-mechanical effects: i.e. effects arising from the mechanical disturbance to the rock caused by the excavation of the emplacement rooms and other underground structures. - Hydraulic and gas-related effects: i.e. the effects of repository resaturation and of gas generation, e.g. due to the corrosion of metals within the repository, on the host rock and engineered barriers. - Chemical effects: i.e. chemical interactions between the waste, the engineered materials and the host rock, with a focus on chemical effects of the waste and engineered materials on the host rock. The assessment of the repository-induced effects shows that detrimental chemical and mechanical impacts are largely confined to the rock immediately adjacent to the excavations, thermal impacts are controllable by limiting the heat load and gas effects are limited by ensuring acceptably low gas production rates and by the natural tendency of the gas to escape along the excavations and the excavation damaged zone (EDZ) rather than through the undisturbed rock. Specific measures that are part of the current reference design are discussed in relation to their significance with respect to repository-induced effects. The SF/HLW emplacement rooms (emplacement drifts) are designed, constructed, operated and finally backfilled in such a way that formation of excavation damaged zones is limited. Specifically this is achieved

  3. High-level waste repository-induced effects

    International Nuclear Information System (INIS)

    Leupin, O.X.; Marschall, P.; Johnson, L.; Cloet, V.; Schneider, J.; Smith, P.; Savage, D.; Senger, R.

    2016-10-01

    This status report aims at describing and assessing the interactions of the radioactive waste emplaced in a high-level waste (HLW) repository with the engineered materials and the Opalinus Clay host rock. The Opalinus Clay has a thickness of about 100 m in the proposed siting regions. Among other things the results are used to steer the RD and D programme of NAGRA. The repository-induced effects considered in this report are of the following broad types: - Thermal effects: i.e. effects on the host rock and engineered barriers arising principally from the heat generated by the waste. - Rock-mechanical effects: i.e. effects arising from the mechanical disturbance to the rock caused by the excavation of the emplacement rooms and other underground structures. - Hydraulic and gas-related effects: i.e. the effects of repository resaturation and of gas generation, e.g. due to the corrosion of metals within the repository, on the host rock and engineered barriers. - Chemical effects: i.e. chemical interactions between the waste, the engineered materials and the host rock, with a focus on chemical effects of the waste and engineered materials on the host rock. The assessment of the repository-induced effects shows that detrimental chemical and mechanical impacts are largely confined to the rock immediately adjacent to the excavations, thermal impacts are controllable by limiting the heat load and gas effects are limited by ensuring acceptably low gas production rates and by the natural tendency of the gas to escape along the excavations and the excavation damaged zone (EDZ) rather than through the undisturbed rock. Specific measures that are part of the current reference design are discussed in relation to their significance with respect to repository-induced effects. The SF/HLW emplacement rooms (emplacement drifts) are designed, constructed, operated and finally backfilled in such a way that formation of excavation damaged zones is limited. Specifically this is achieved

  4. Low and intermediate level waste repositories: Socioeconomic aspects and public involvement. Proceedings of a workshop

    International Nuclear Information System (INIS)

    2007-06-01

    Waste management facilities are needed to protect the environment and improve public health for the long term future. One significant challenge is to inform the public on the relative hazards of radioactive waste compared to other hazards in our modern society and to get the acceptance of the appropriate members of the public for these necessary facilities. Over the entire life cycle of these facilities, the projects must be managed without expending a disproportionate share of the collective resources. Public involvement plays a key role and the sophisticated and extensive public education systems that exist provide a vital service to gain public acceptance. There is a full range of compensation and benefit programmes used as incentives for hosting a LILW facility. Even if exemptions exist the experience in most countries indicate the direct/indirect incentives as a necessary part of gaining public acceptance. The countries, regions and local communities have their own established processes to make public decisions. Each organization developing a site must select and implement the methods that are acceptable within their framework of laws and regulations. A three day workshop on socio-economic issues and public involvement practices and approaches for developing and operating repositories for low and intermediate level waste took place in the IAEA headquarters on 9-11 November 2005. The workshop provided a forum where experts from Member States shared their experiences in non-technical aspects of planning, licensing and operating LILW disposal facilities. Description of both principles and practices applied in particular countries provides a useful overview of potential approaches in application of non-technical issues during a repository lifecycle. Participants presented approaches and practices applied in their countries, established new contacts and were able to take advantage of activities and experiences from abroad. There were 25 interesting presentations

  5. Parametric study of geohydrologic performance characteristics for geologic waste repositories

    International Nuclear Information System (INIS)

    Bailey, C.E.; Marine, I.W.

    1980-11-01

    One of the major objectives of the National Waste Terminal Storage Program is to identify potential geologic sites for storage and isolation of radioactive waste (and possibly irradiated fuel). Potential sites for the storage and isolation of radioactive waste or spent fuel in a geologic rock unit are being carefully evaluated to ensure that radionuclides from the stored waste or fuel will never appear in the biosphere in amounts that would constitute a hazard to the health and safety of the public. The objective of this report is to quantify and present in graphical form the effects of significant geohydrologic and other performance characteristics that would influence the movement of radionuclides from a storage site in a rock unit to the biosphere. The effort in this study was focused on transport by groundwater because that is the most likely method of radionuclide escape. Graphs of the major performance characteristics that influence the transport of radionuclides from a repository to the biosphere by groundwater are presented. The major characteristics addressed are radioactive decay, leach rate, hydraulic conductivity, porosity, groundwater gradient, hydrodynamic dispersion, ion exchange, and distance to the biosphere. These major performance characteristics are combind with each other and with the results of certain other combinations and presented in graphical form to provide the interrelationships of values measured during field studies. The graphical form of presentation should be useful in the screening process of site selection. An appendix illustrates the use of these graphs to assess the suitability of a site

  6. Deep geologic repository for low and intermediate radioactive level waste in Canada

    International Nuclear Information System (INIS)

    Liu Jianqin; Li Honghui; Sun Qinghong; Yang Zhongtian

    2012-01-01

    Ontario Power Generation (OPG) is undergoing a project for the long-term management of low and intermediate level waste (LILW)-a deep geologic repository (DGR) project for low and intermediate level waste. The waste source term disposed, geologic setting, repository layout and operation, and safety assessment are discussed. It is expected to provide reference for disposal of low and intermediate level waste that contain the higher concentration of long-lived radionuclides in China. (authors)

  7. Application of sulfur concrete for solidification of radioactive wastes and building of repositories

    International Nuclear Information System (INIS)

    Cholerzynski, A.; Tomczak, W.; Switalski, J.

    2000-01-01

    The application of sulfur concrete as solidification material for radioactive wastes and as building material used in repositories have been presented. Their high shear strength, low level of leaching, and high radiation resistance decide of positive recommendation of such material for wide use in radioactive waste treatment processes and repositories building

  8. Overview of the United States' nuclear waste repository programme

    International Nuclear Information System (INIS)

    Surles, T.G.

    2002-01-01

    Regardless of the future of civilian or defense-based nuclear materials, the United States will be responsible for a vast array of these materials for generations to come. The cornerstone programme for the disposal of waste materials is the Yucca Mountain Programme. Based on the Nuclear Waste Policy Act of 1982, as amended in 1987, it has been the United States' policy to develop a geological repository for the permanent disposal of radioactive waste materials. This presentation will discuss the process and strategy leading to the present and will include the scientific and management activities required to support the recent Viability Assessment. Also to be discussed are the timeline and milestones leading to the opening of the repository. The focus will be on the scientific and engineering studies required for a successful Site Recommendation, and then for a similarly successful License Application. Both of these activities will require considerable management efforts in addressing legal and regulatory issues. Finally, the presentation will discuss projections for the future operation of the facility, including emplacement projections, coupled with the required locations of nuclear materials. Additional scientific research and engineering studies will also be conducted to determine the longer-term viability of the facility, which is designed, by policy, for permanent storage. Retrievability is currently not an option, although access to the facility will be maintained for several decades. The focus of the discussion will be on the scientific and engineering advances made on understanding the natural systems for preventing migration of radionuclides, coupled with new developments in engineered systems in areas such as cask cladding, drip shields, and related materials engineering developments. The coupling of engineered and natural systems is designed to offer safety factors that are several orders of magnitude greater than what is estimated to be necessary

  9. Reinforced concrete in the intermediable-level nuclear waste repository

    International Nuclear Information System (INIS)

    Duffo, Gustavo

    2009-01-01

    The National Atomic Energy Commission (CNEA) is responsible for developing the nuclear waste disposal management programme. This programme contemplates the design and construction of a facility for the final disposal of intermediate-level radioactive wastes. The proposed model is a near-surface monolithic repository similar to those in operation in El Cabril, Spain. The design of this type of repository is based on the use of multiple, independent and redundant barriers and the model foresees a period of 300 years of institutional post-closure control. Since the vault and cover are major components of the engineered barriers, the durability of these concrete structures is an important aspect for the facility integrity. This work presents laboratory investigations performed on the corrosion susceptibility of steel rebars embedded in two different types of high performance reinforced concretes, recently developed by the National Institute of Industrial Technology (Argentine). Concretes were made with cement with Blast Furnace Slag (CAH) and Silica Fume cement (CAH + SF). The aim of this work is to predict the service life of the intermediate level radioactive waste disposal vaults from data obtained from electrochemical techniques. Besides, the diffusion coefficients of aggressive species, such as chloride and carbon dioxide, were also determined. On the other hand, data obtained with corrosion sensors embedded in a vault prototype is also included. These sensors allow on-line measurements of several parameters related to the corrosion process such as rebar corrosion potential and corrosion current density; incoming oxygen flow that reaches the metal surface; concrete electrical resistivity; chloride concentration and internal concrete temperature. All the information obtained from both, laboratory tests and sensors will be used for the final design of the container in order to achieve a service life more or equal than the foreseen durability for this type of

  10. Waste Package and Material Testing for the Proposed Yucca Mountain High Level Waste Repository

    International Nuclear Information System (INIS)

    Doering, Thomas; Pasupathi, V.

    2002-01-01

    Over the repository lifetime, the waste package containment barriers will perform various functions that will change with time. During the operational period, the barriers will function as vessels for handling, emplacement, and waste retrieval (if necessary). During the years following repository closure, the containment barriers will be relied upon to provide substantially complete containment, through 10,000 years and beyond. Following the substantially complete containment phase, the barriers and the waste package internal structures help minimize release of radionuclides by aqueous- and gaseous-phase transport. These requirements have lead to a defense-in-depth design philosophy. A multi-barrier design will result in a lower breach rate distributed over a longer period of time, thereby ensuring the regulatory requirements are met. The design of the Engineered Barrier System (EBS) has evolved. The initial waste package design was a thin walled package, 3/8 inch of stainless steel 304, that had very limited capacity, (3 PWR and 4 BWR assemblies) and performance characteristics, 300 to 1,000 years. This design required over 35,000 waste packages compared to today's design of just over 10,000 waste packages. The waste package designs are now based on a defense-in-depth/multi-barrier philosophy and have a capacity similar to the standard storage and rail transported spent nuclear fuel casks. Concurrent with the development of the design of the waste packages, a comprehensive waste package materials testing program has been undertaken to support the selection of containment barrier materials and to develop predictive models for the long-term behavior of these materials under expected repository conditions. The testing program includes both long-term and short-term tests and the results from these tests combination with the data published in the open literature are being used to develop models for predicting performance of the waste packages

  11. Preliminary concepts: materials management in an internationally safeguarded nuclear-waste geologic repository

    International Nuclear Information System (INIS)

    Ostenak, C.A.; Whitty, W.J.; Dietz, R.J.

    1979-11-01

    Preliminary concepts of materials accountability are presented for an internationally safeguarded nuclear-waste geologic repository. A hypothetical reference repository that receives nuclear waste for emplacement in a geologic medium serves to illustrate specific safeguards concepts. Nuclear wastes received at the reference repository derive from prior fuel-cycle operations. Alternative safeguards techniques ranging from item accounting to nondestructive assay and waste characteristics that affect the necessary level of safeguards are examined. Downgrading of safeguards prior to shipment to the repository is recommended whenever possible. The point in the waste cycle where international safeguards may be terminate depends on the fissile content, feasibility of separation, and practicable recoverability of the waste: termination may not be possible if spent fuels are declared as waste

  12. UN Data: Environment Statistics: Waste

    Data.gov (United States)

    World Wide Human Geography Data Working Group — The Environment Statistics Database contains selected water and waste statistics by country. Statistics on water and waste are based on official statistics supplied...

  13. Aerosol particle transport modeling for preclosure safety studies of nuclear waste repositories

    International Nuclear Information System (INIS)

    Gelbard, F.

    1989-01-01

    An important concern for preclosure safety analysis of a nuclear waste repository is the potential release to the environment of respirable aerosol particles. Such particles, less than 10 μm in aerodynamic diameter, may have significant adverse health effects if inhaled. To assess the potential health effects of these particles, it is not sufficient to determine the mass fraction of respirable aerosol. The chemical composition of the particles is also of importance since different radionuclides may pose vastly different health hazards. Thus, models are needed to determine under normal and accident conditions the particle size and the chemical composition distributions of aerosol particles as a function of time and of position in the repository. In this work a multicomponent sectional aerosol model is used to determine the aerosol particle size and composition distributions in the repository. A range of aerosol mass releases with varying mean particle sizes and chemical compositions is used to demonstrate the sensitivities and uncertainties of the model. Decontamination factors for some locations in the repository are presented. 8 refs., 1 tab

  14. Application of GIS in siting disposal repository for high level radioactive waste

    International Nuclear Information System (INIS)

    Zhong Xia; Wang Ju; Huang Shutao

    2010-01-01

    High level radioactive waste geo-disposal is directly related to environment protection and Sustainable Utilization of nuclear energy. To ensure both success and long-term safe disposal of the high level-radioactive waste, finding suitable sites is an important step in the research. Meanwhile, siting and evaluation the geo-disposal repository for high level-radioactive waste need a wide range of relevant information, including geology and geophysical surveys data, geochemistry data and other geoscience data in the field. At the same time, some of the data has its spatial property. Geographic information system (GIS) have a role to play in all geographic and spatial aspects of the development and management of the siting disposal repository. GIS has greatly enhanced our ability to store, analyze and communicate accounts of the information. This study was conducted to compare the more suitable sites for the repository using GIS -based on the data which belongs to the preselected area in BeiShan, Gansu Province, China. First, the data of the pre-selected site is captured by GIS and stored in the geoscience database. Then, according to the relevant guide line in the field, the analysis models based on GIS are build. There are some thematic layers of the sites character grouped into two basic type, namely social factors(town, traffic and nuclear plant) and natural factors (water, land and animals and plants).In the paper, a series of GIS models was developed to compare the pre-selected areas in order to make optimal decision. This study shows that with appropriate and enough information GIS used in modeling is a powerful tool for site selection for disposal repository. (authors)

  15. FFSM, Long-Term Nuclear Waste Repository Site Simulation by Monte-Carlo

    International Nuclear Information System (INIS)

    Hadlock, L.R.; Hellstrom, D.I.; Mikulis, M.J.B.; Little, A.D.; Golis, M.J.

    1988-01-01

    1 - Description of program or function: FFSM (Far Field State Model) predicts the approximate geologic and climatic state of a site for a nuclear waste repository over relatively long periods of time. The purpose of FFSM is to represent quantitatively certain events and processes that could alter the effectiveness of one or more natural barriers in a waste isolation system. The barriers treated by the model are primarily components of the geologic environment surrounding the repository, although biosphere components (e.g. climate parameters) that could affect the impact of radionuclide releases are also considered. These components are treated outside the realm of wastes or repository-induced effects, which is indicated by use of the term f ar field . The model treats both natural and man-induced changes in these barriers within a probabilistic framework, and it accounts for cumulative and interactive effects of multiple phenomena. 2 - Method of solution: Fifteen submodels are included in FFSM to account for phenomena that may be of importance individually or in combination in evaluating sites for repositories. These submodels include: undetected features, climate, worldwide glaciation, local glaciation, folding, salt dispersion, magmatic events, faulting, biosphere state, regional deformation, geomorphic processes, dissolution fronts, localized dissolution (breccia pipes), solution mining, and drilling. FFSM can be used in both a deterministic mode, to evaluate interactions or to calculate point values, and a probabilistic mode, to make statistical estimates of future changes. In the probabilistic mode, Monte Carlo simulation is used to generate output probabilities, based on user-supplied input, largely in the form of probability density functions for variable or uncertain parameters

  16. A feasibility study for the design of a simulated radioactive waste repository facility

    International Nuclear Information System (INIS)

    1986-10-01

    The paper contains the text and references of a feasibility study for the design of a simulated radioactive waste repository facility (final report). The work was commissioned by the Department of the Environment, United Kingdom, as part of its radioactive waste management research programme. The nature of the candidate buffer materials, the factors defining their behaviour, and the nature of a buffer material selection and testing programme, are examined. A description is given of the properties and modelling of host materials. The complex interactions between host materials, and between buffer and host materials, are discussed, along with the instrumentation requirements for measuring the interactions. Finally, the temperature field around a waste package, and modelling a host continuum with a segmental block, are both investigated. (U.K.)

  17. Selection criteria for container materials at the proposed Yucca Mountain high level nuclear waste repository

    International Nuclear Information System (INIS)

    Halsey, W.G.

    1989-11-01

    A geological repository has been proposed for the permanent disposal of the nation's high level nuclear waste at Yucca Mountain in the Nevada desert. The containers for this waste must remain intact for the unprecedented service lifetime of 1000 years. A combination of engineering, regulatory, and licensing requirements complicate the container material selection. In parallel to gathering information regarding the Yucca Mountain service environment and material performance data, a set of selection criteria have been established which compare candidate materials to the performance requirements, and allow a quantitative comparison of candidates. These criteria assign relative weighting to varied topic areas such as mechanical properties, corrosion resistance, fabricability, and cost. Considering the long service life of the waste containers, it is not surprising that the corrosion behavior of the material is a dominant factor. 7 refs

  18. The use of performance assessments in Yucca Mountain repository waste package design activities

    International Nuclear Information System (INIS)

    Jardine, L.J.

    1990-01-01

    The Yucca Mountain Project is developing performance assessment approaches as part of the evaluations of the suitability of Yucca Mountain as a repository site. Lawrence Livermore National Laboratory is developing design concepts and the scientific performance assessment methodologies and techniques used for the waste package and engineered barrier system components. This paper presents an overview of the approach under development for postclosure performance assessments that will guide the conceptual design activities and assist in the site suitability evaluations. This approach includes establishing and modeling for the long time periods required by regulations: near-field environment characteristics surrounding the emplaced wastes; container materials performance responses; and waste form properties. All technical work is being done under a fully qualified quality assurance program

  19. Seismotectonic investigations for Yucca Mountain high-level waste repository: Rationale for defining scope

    International Nuclear Information System (INIS)

    Gupta, D.C.; Blackford, M.E.

    1990-01-01

    The geologic, seismic, and engineering characteristics of the Yucca Mountain site and its environs need to be investigated in sufficient scope and detail to provide reasonable assurance that they are sufficiently well understood to permit an adequate evaluation of the proposed site for the development of a high-level waste repository. The paper examines the extent of seismotectonic investigations needed for proper evaluation of the geologic setting. At the Yucca Mountain site, a thorough understanding of tectonic phenomena such as seismicity and faulting is critical to the identification of potentially disqualifying conditions. Study of the tectonic movement, stress, or co-tectonic effects that could affect the performance of the waste-handling facilities, waste package, underground openings, shaft and borehole seals, and long-term alteration of geohydrology would be necessary. In addition, the uncertainties involved in evaluating the effect of seismotectonics on the radionuclide transport mechanism need to be thoroughly investigated. 8 refs., 1 fig

  20. Backfill barriers for nuclear waste repositories in salt

    Energy Technology Data Exchange (ETDEWEB)

    Nowak, E J; Odoj, R; Merz, E [eds.

    1981-06-01

    Backfill materials were evaluated for containment of radionuclides, chemical modification of brine, and sensitivity to hydrothermal conditions. Experimental conditions were relevant to nuclear waste isolation in bedded salt. They were based on geologic conditions at the site of the Waste Isolation Pilot Plant (WIPP) in southeastern New Mexico, USA. Conclusions are: backfill mixtures surrounding the waste form and canister can provide a neutral or slightly acidic, potentially reducing environment, prevent convective aqueous flow, and act as an effective radionuclide migration barrier; bentonite is likely to remain hydrothermally stable but potentially sensitive to waste package interactions which could alter the pH, the ratio of dissolved ions, or the sorption properties of radionuclide species; effects of irradiation from high level waste should be investigated.

  1. Office of Geologic Repositories quality assurance plan for high-level radioactive waste repositories

    International Nuclear Information System (INIS)

    1986-08-01

    This document sets forth geologic repository program-wide quality assurance program requirements and defines management's quality assurance responsibilities for the Office of Geologic Repositories and its projects. (LM)

  2. Feasibility assessment of copper-base waste package container materials in a tuff repository

    International Nuclear Information System (INIS)

    Acton, C.F.; McCright, R.D.

    1986-01-01

    This report discussed progress made during the second year of a two-year study on the feasibility of using copper or a copper-base alloy as a container material for a waste package in a potential repository in tuff rock at the Yucca Mountain site in Nevada. Corrosion testing in potentially corrosive irradiated environments received emphasis during the feasibility study. Results of experiments to evaluate the effect of a radiation field on the uniform corrosion rate of the copper-base materials in repository-relevant aqueous environments are given as well as results of an electrochemical study of the copper-base materials in normal and concentrated J-13 water. Results of tests on the irradiation of J-13 water and on the subsequent formation of hydrogen peroxide are given. A theoretical study was initiated to predict the long-term corrosion behavior of copper in the repository. Tests were conducted to determine whether copper would adversely affect release rates of radionuclides to the environment because of degradation of the Zircaloy cladding. A manufacturing survey to determine the feasibility of producing copper containers utilizing existing equipment and processes was completed. The cost and availability of copper was also evaluated and predicted to the year 2000. Results of this feasibility assessment are summarized

  3. Analogues to features and processes of a high-level radioactive waste repository proposed for Yucca Mountain, Nevada

    Science.gov (United States)

    Simmons, Ardyth M.; Stuckless, John S.; with a Foreword by Abraham Van Luik, U.S. Department of Energy

    2010-01-01

    Natural analogues are defined for this report as naturally occurring or anthropogenic systems in which processes similar to those expected to occur in a nuclear waste repository are thought to have taken place over time periods of decades to millennia and on spatial scales as much as tens of kilometers. Analogues provide an important temporal and spatial dimension that cannot be tested by laboratory or field-scale experiments. Analogues provide one of the multiple lines of evidence intended to increase confidence in the safe geologic disposal of high-level radioactive waste. Although the work in this report was completed specifically for Yucca Mountain, Nevada, as the proposed geologic repository for high-level radioactive waste under the U.S. Nuclear Waste Policy Act, the applicability of the science, analyses, and interpretations is not limited to a specific site. Natural and anthropogenic analogues have provided and can continue to provide value in understanding features and processes of importance across a wide variety of topics in addressing the challenges of geologic isolation of radioactive waste and also as a contribution to scientific investigations unrelated to waste disposal. Isolation of radioactive waste at a mined geologic repository would be through a combination of natural features and engineered barriers. In this report we examine analogues to many of the various components of the Yucca Mountain system, including the preservation of materials in unsaturated environments, flow of water through unsaturated volcanic tuff, seepage into repository drifts, repository drift stability, stability and alteration of waste forms and components of the engineered barrier system, and transport of radionuclides through unsaturated and saturated rock zones.

  4. Annular air space effects on nuclear waste canister temperatures in a deep geologic waste repository

    International Nuclear Information System (INIS)

    Lowry, W.E.; Cheung, H.; Davis, B.W.

    1980-01-01

    Air spaces in a deep geologic repository for nuclear high level waste will have an important effect on the long-term performance of the waste package. The important temperature effects of an annular air gap surrounding a high level waste canister are determined through 3-D numerical modeling. Air gap properties and parameters specifically analyzed and presented are the air gap size, surfaces emissivity, presence of a sleeve, and initial thermal power generation rate; particular emphasis was placed on determining the effect of these variables have on the canister surface temperature. Finally a discussion based on modeling results is presented which specifically relates the results to NRC regulatory considerations

  5. Environmental release of carbon-14 gas from a hypothetical nuclear waste repository

    International Nuclear Information System (INIS)

    Lehto, M.A.; Merrell, G.B.

    1994-01-01

    Radioisotopes may form gases in a spent nuclear fuel waste package due to elevated temperatures or degradation of the fuel rods. Radioactive carbon-14, as gaseous carbon dioxide, is one of the gaseous radioisotopes of concern at an underground disposal facility for spent nuclear fuel and high-level radioactive waste. Carbon-14 dioxide may accumulate inside an intact waste container. Upon breach of the container, a potentially large pulse of carbon-14 dioxide gas may be released to the surrounding environment, followed by a lower, long-term continuous release. If the waste were disposed of in an unsaturated geologic environment, the carbon-14 gas would begin to move through the unsaturated zone to the accessible environment. This study investigates the transport of radioactive carbon-14 gas in geologic porous media using a one-dimensional analytical solution. Spent nuclear fuel emplaced in a deep geologic repository located at a generic unsaturated tuff site is analyzed. The source term for the carbon-14 gas and geologic parameters was obtained from previously published materials. The one-dimensional analytical solution includes diffusion, advection, radionuclide retardation, and radioactive decay terms. Two hypothetical sites are analyzed. One is dominated by advective transport, and the other is dominated by diffusive transport. The dominant transport mechanism at an actual site depends on the site characteristics. Results from the simulations include carbon-14 dioxide travel times to the accessible environment and the total release to the environment over a 10,000-year period. The results are compared to regulatory criteria

  6. Damage-plasticity model of the host rock in a nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Koudelka, Tomáš; Kruis, Jaroslav, E-mail: kruis@fsv.cvut.cz [Department of Mechanics, Faculty of Civil Engineering, Czech Technical University in Prague, Thákurova 7, 166 29 Prague (Czech Republic)

    2016-06-08

    The paper describes damage-plasticity model for the modelling of the host rock environment of a nuclear waste repository. Radioactive Waste Repository Authority in Czech Republic assumes the repository to be in a granite rock mass which exhibit anisotropic behaviour where the strength in tension is lower than in compression. In order to describe this phenomenon, the damage-plasticity model is formulated with the help of the Drucker-Prager yield criterion which can be set to capture the compression behaviour while the tensile stress states is described with the help of scalar isotropic damage model. The concept of damage-plasticity model was implemented in the SIFEL finite element code and consequently, the code was used for the simulation of the Äspö Pillar Stability Experiment (APSE) which was performed in order to determine yielding strength under various conditions in similar granite rocks as in Czech Republic. The results from the performed analysis are presented and discussed in the paper.

  7. Thermal characteristics of rocks for high-level waste repository

    International Nuclear Information System (INIS)

    Shimooka, Kenji; Ishizaki, Kanjiro; Okamoto, Masamichi; Kumata, Masahiro; Araki, Kunio; Amano, Hiroshi

    1980-12-01

    Heat released by the radioactive decay of high-level waste in an underground repository causes a long term thermal disturbance in the surrounding rock mass. Several rocks constituting geological formations in Japan were gathered and specific heat, thermal conductivity, thermal expansion coefficient and compressive strength were measured. Thermal analysis and chemical analysis were also carried out. It was found that volcanic rocks, i.e. Andesite and Basalt had the most favorable thermal characteristics up to around 1000 0 C and plutonic rock, i.e. Granite had also favorable characteristics under 573 0 C, transition temperature of quartz. Other igneous rocks, i.e. Rhyolite and Propylite had a problem of decomposition at around 500 0 C. Sedimentary rocks, i.e. Zeolite, Tuff, Sandstone and Diatomite were less favorable because of their decomposition, low thermal conductivity and large thermal expansion coefficient. (author)

  8. Geotechnical support and topical studies for nuclear waste geologic repositories

    International Nuclear Information System (INIS)

    1989-01-01

    The present report lists the technical reviews and comments made during the fiscal year 1988 and summarizes the technical progress of the topical studies. In the area of technical assistance, there were numerous activities detailed in the next section. These included 24 geotechnical support activities, including reviews of 6 Study Plans (SP) and participation in 6 SP Review Workshops, review of one whole document Site Characterization Plan (SCP) and participation in the Assembled Document SCP Review Workshops by 6 LBL reviewers; the hosting of a DOE program review, the rewriting of the project statement of work, 2 trips to technical and planning meetings; preparation of proposed work statements for two new topics for DOE, and 5 instances of technical assistance to DOE. These activities are described in a Table in the following section entitled ''Geoscience Technical Support for Nuclear Waste Geologic Repositories.''

  9. Micronuclei rate in workers of Novi Han radioactive waste repository

    International Nuclear Information System (INIS)

    Atamasova, P.; Hadjidekova, V.

    2003-01-01

    A cytogenetic study has been carried out by the micronucleus test of lymphocytes from the peripheral blood of 30 workers from the Novi Han radioactive waste repository. The results are compared to the results of a control group of 6 persons from the administrative staff, and to outside group of 39 healthy persons. All persons are questioned through a special questionnaire about their occupational, medical, and social status. The rate of the cells with micronuclei and the total number of the micronuclei are analysed in the peripheral blood lymphocytes using the cytogenesis-block micronucleus test. The comparison of the results does not show an increase of the lymphocytes with micronuclei in the workers

  10. General guidelines for recommendation of sites for nuclear waste repositories

    International Nuclear Information System (INIS)

    1983-01-01

    These guidelines were developed in accordance with the requirements of Section 112(a) of the Nuclear Waste Policy Act of 1982 for use by the Secretary of Energy in evaluating the suitability of sites for the development of repositories. The guidelines will be used for suitability evaluations and determinations made pursuant to Section 112(b) and any preliminary suitability determinations required by Section 114(f). The guidelines set forth in this Part are intended to complement the requirements set forth in the Act, 10 CFR Part 60, and 40 CFR Part 191. In applying these guidelines, the DOE will resolve any inconsistencies between these guidelines and the above documents in a manner determined by the DOE to most closely agree with the intent of the Act

  11. Use of Groundwater Lifetime Expectancy for the Performance Assessment of Deep Geologic Radioactive Waste Repositories.

    Science.gov (United States)

    Cornaton, F.; Park, Y.; Normani, S.; Sudicky, E.; Sykes, J.

    2005-12-01

    Long-term solutions for the disposal of toxic wastes usually involve isolation of the wastes in a deep subsurface geologic environment. In the case of spent nuclear fuel, the safety of the host repository depends on two main barriers: the engineered barrier and the natural geological barrier. If radionuclide leakage occurs from the engineered barrier, the geological medium represents the ultimate barrier that is relied upon to ensure safety. Consequently, an evaluation of radionuclide travel times from the repository to the biosphere is critically important in a performance assessment analysis. In this study, we develop a travel time framework based on the concept of groundwater lifetime expectancy as a safety indicator. Lifetime expectancy characterizes the time radionuclides will spend in the subsurface after their release from the repository and prior to discharging into the biosphere. The probability density function of lifetime expectancy is computed throughout the host rock by solving the backward-in-time solute transport equation subject to a properly posed set of boundary conditions. It can then be used to define optimal repository locations. In a second step, the risk associated with selected sites can be evaluated by simulating an appropriate contaminant release history. The proposed methodology is applied in the context of a typical Canadian Shield environment. Based on a statistically-generated three-dimension network of fracture zones embedded in the granitic host rock, the sensitivity and the uncertainty of lifetime expectancy to the hydraulic and dispersive properties of the fracture network, including the impact of conditioning via their surface expressions, is computed in order to demonstrate the utility of the methodology.

  12. Molecular hydrogen: An abundant energy source for bacterial activity in nuclear waste repositories

    Science.gov (United States)

    Libert, M.; Bildstein, O.; Esnault, L.; Jullien, M.; Sellier, R.

    A thorough understanding of the energy sources used by microbial systems in the deep terrestrial subsurface is essential since the extreme conditions for life in deep biospheres may serve as a model for possible life in a nuclear waste repository. In this respect, H 2 is known as one of the most energetic substrates for deep terrestrial subsurface environments. This hydrogen is produced from abiotic and biotic processes but its concentration in natural systems is usually maintained at very low levels due to hydrogen-consuming bacteria. A significant amount of H 2 gas will be produced within deep nuclear waste repositories, essentially from the corrosion of metallic components. This will consequently improve the conditions for microbial activity in this specific environment. This paper discusses different study cases with experimental results to illustrate the fact that microorganisms are able to use hydrogen for redox processes (reduction of O 2, NO3-, Fe III) in several waste disposal conditions. Consequences of microbial activity include: alteration of groundwater chemistry and shift in geochemical equilibria, gas production or consumption, biocorrosion, and potential modifications of confinement properties. In order to quantify the impact of hydrogen bacteria, the next step will be to determine the kinetic rate of the reactions in realistic conditions.

  13. Molecular hydrogen: An abundant energy source for bacterial activity in nuclear waste repositories

    International Nuclear Information System (INIS)

    Libert, M.; Bildstein, O.; Esnault, L.; Jullien, M.; Sellier, R.

    2011-01-01

    A thorough understanding of the energy sources used by microbial systems in the deep terrestrial subsurface is essential since the extreme conditions for life in deep biospheres may serve as a model for possible life in a nuclear waste repository. In this respect, H 2 is known as one of the most energetic substrates for deep terrestrial subsurface environments. This hydrogen is produced from abiotic and biotic processes but its concentration in natural systems is usually maintained at very low levels due to hydrogen-consuming bacteria. A significant amount of H 2 gas will be produced within deep nuclear waste repositories, essentially from the corrosion of metallic components. This will consequently improve the conditions for microbial activity in this specific environment. This paper discusses different study cases with experimental results to illustrate the fact that microorganisms are able to use hydrogen for redox processes (reduction of O 2 , NO 3- , Fe III) in several waste disposal conditions. Consequences of microbial activity include: alteration of groundwater chemistry and shift in geochemical equilibria, gas production or consumption, bio-corrosion, and potential modifications of confinement properties. In order to quantify the impact of hydrogen bacteria, the next step will be to determine the kinetic rate of the reactions in realistic conditions. (authors)

  14. 75 FR 8701 - Notice of Settlement Agreement Pertaining to Construction of a Waste Repository on the Settlors...

    Science.gov (United States)

    2010-02-25

    ... Construction of a Waste Repository on the Settlors' Property Pursuant to the Comprehensive Environmental... a Settlement Agreement pertaining to Construction of a Waste Repository on Settlor's Property... waste repository on the property by resolving, liability the settling party might otherwise incur under...

  15. Pre-treatment of bituminized NPP wastes for disposal in near-surface repository

    Energy Technology Data Exchange (ETDEWEB)

    Vieira, Vanessa Mota; Tello, Clédola Cássia Oliveira de, E-mail: vanessamotavieira@gmail.com, E-mail: tellocc@cdtn.br [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)

    2017-07-01

    The implementation of the national repository is an important technical requirement, and a legal requirement for the entry into operation of the nuclear power plant Angra 3. The Brazilian repository is being planned to be a near-surface one. In Brazil the low and intermediate level radioactive wastes are immobilized using cement and bitumen for Angra 1 and Angra 2 NPP, respectively. The main problems due to the disposal of bituminized wastes in repositories are swelling of the waste products and their degradation in the long term. To accommodate the swelling of the bituminized wastes, the drums are filled up to 70 - 90% of their volume, which reduces the structural the repository stability and the disposal availability. Countries, which use bitumen in the solidification of NPP's radioactive waste and have near-surface repositories, need to immobilize this bituminized waste within other drums containing cement pastes or mortars to disposal them. This study aims to find solutions for the storage in surface repository of bituminized radioactive waste products, making them compatible with the acceptance criteria of cemented waste products. It was also performed a modeling with the results obtained in the leaching test using the ALT program and defined the transport model of the cesium leachate element and it was verified that in the early times the leaching was governed by the diffusion model and later by the partition model. The results obtained in this study can be used in the evaluation of performance of repositories. (author)

  16. Pre-treatment of bituminized NPP wastes for disposal in near-surface repository

    International Nuclear Information System (INIS)

    Vieira, Vanessa Mota; Tello, Clédola Cássia Oliveira de

    2017-01-01

    The implementation of the national repository is an important technical requirement, and a legal requirement for the entry into operation of the nuclear power plant Angra 3. The Brazilian repository is being planned to be a near-surface one. In Brazil the low and intermediate level radioactive wastes are immobilized using cement and bitumen for Angra 1 and Angra 2 NPP, respectively. The main problems due to the disposal of bituminized wastes in repositories are swelling of the waste products and their degradation in the long term. To accommodate the swelling of the bituminized wastes, the drums are filled up to 70 - 90% of their volume, which reduces the structural the repository stability and the disposal availability. Countries, which use bitumen in the solidification of NPP's radioactive waste and have near-surface repositories, need to immobilize this bituminized waste within other drums containing cement pastes or mortars to disposal them. This study aims to find solutions for the storage in surface repository of bituminized radioactive waste products, making them compatible with the acceptance criteria of cemented waste products. It was also performed a modeling with the results obtained in the leaching test using the ALT program and defined the transport model of the cesium leachate element and it was verified that in the early times the leaching was governed by the diffusion model and later by the partition model. The results obtained in this study can be used in the evaluation of performance of repositories. (author)

  17. The role of weapons production and military waste in the repository selection process

    International Nuclear Information System (INIS)

    Nelson, D.; Hope, J.; Power, W.; Hunter, T.

    1987-01-01

    The decision to commingle defense waste with commercial waste in the nuclear waste repository program has many impacts on that program. There will be more waste to place in the two repositories authorized under the Nuclear Waste Policy Act, more transport miles to get the waste to a repository, and more costs associated with environmental and socio-economic impact mitigation. This paper explores the links between weapons production and military waste, and the repository selection process. The paper first describes the importance of state, tribe and public participation to the acceptance of a repository site selection. The paper then examines the various estimates of amounts of existing and future military nuclear wastes, and how these estimates affect repository siting decisions. The final section addresses the public policy questions which surround this issue. Repository siting may be jeopardized unless there is open public discussion about existing radioactive contamination at military production sites and about future nuclear weapons production. Cost-sharing is considered within this context

  18. Application of systems engineering to determine performance requirements for repository waste packages

    International Nuclear Information System (INIS)

    Aitken, E.A.; Stimmell, G.L.

    1987-01-01

    The waste package for a nuclear waste repository in salt must contribute substantially to the performance objectives defined by the Salt Repository Project (SRP) general requirements document governing disposal of high-level waste. The waste package is one of the engineered barriers providing containment. In establishing the performance requirements for a project focused on design and fabrication of the waste package, the systems engineering methodology has been used to translate the hierarchy requirements for the repository system to specific performance requirements for design and fabrication of the waste package, a subsystem of the repository. This activity is ongoing and requires a methodology that provides traceability and is capable of iteration as baseline requirements are refined or changed. The purpose of this summary is to describe the methodology being used and the way it can be applied to similar activities in the nuclear industry

  19. Waste package materials testing for a salt repository: 1983 status summary report

    International Nuclear Information System (INIS)

    Moak, D.P.

    1986-09-01

    The United States plans to safely dispose of nuclear waste in deep, stable geologic formations. As part of these plans, the US Department of Energy is sponsoring research on the designing and testing of waste packages and waste package materials. This fiscal year 1983 status report summarizes recent results of waste package materials testing in a salt environment. The results from these tests will be used by waste package designers and performance assessment experts. Release characteristics data are available on two waste forms (spent fuel and waste-containing glass) that were exposed to leaching tests at various radiation levels, temperatures, pH, glass surface area to solution volume ratios, and brine solutions simulating expected salt repository conditions. Candidate materials tested for corrosion resistance and other properties include iron alloys; TI-CODE 12, the most promising titanium alloy for containment; and nickel alloys. In component interaction testing, synergistic effects have not ruled out any candidate material. 21 refs., 37 figs., 15 tabs

  20. Refinancing of the search for a repository and of the repository for heat generating radioactive Waste. Pt. 2

    International Nuclear Information System (INIS)

    Moench, Christoph

    2013-01-01

    Part I of this article, which appeared in the preceding issue, described in general terms the background to the search for a disposal site and the result of the exploration to date of the repository, which would appear to be suitable from a mining standpoint according to the present knowledge. According to the rules in effect up to now, the exploration and construction would be financed by advance payments on the contributions of the waste producing companies, in particular the utility companies. The working draft of an 'Act on the search for and selection of a site for a repository for heat generating radioactive waste' (Gesetz zur Suche und Auswahl eines Standortes fuer ein Endlager fuer waermeentwickelnde radioaktive Abfaelle) from autumn 2012 provides for a new version of section 21b Atomic Energy Act, under which the costs for 'carrying out a repository selection procedure pursuant to the Repository Selection Act (Standort-auswahlgesetz)' would be allocated to the future users of the repository who are obliged to make contributions as a 'necessary expense'. Part II evaluates this provision of the working draft on the basis of the financial constitutional law. A comparison of sites is not a measure that could be allocated to the future users of the repository who are obliged to make contributions as a 'necessary expense'. Moreover, there is a lack of responsibility for the financing and of a legally relevant advantage that would be conferred by a cumulative alternative repository search for the later users of the repository who are obliged to provide the pre-financing. The costs can therefore not be allocated to the later users as either a contribution or a special charge, not even by way of an association with mandatory membership (Zwangsverband). They must be borne by the state. Consequently, the allocation stipulated by provision would constitute an impermissible charge under financial constitutional law. (orig.)

  1. Surface-type repository for low and intermediate level radioactive waste in the Republic of Croatia

    International Nuclear Information System (INIS)

    Kucar-Dragicevic, S.; Zarkovic, V.; Subasic, D.

    1995-01-01

    The low-level intermediate-level (LL/IL) radioactive waste repository siting and construction project is one of the activities related to establishing the rad waste management system in the Republic of Croatia. The repository project design is one in an array of project activities which also include the site selection procedure and public attitude issues. The prepared design documentation gives technical, safety and financial background relevant for making a final decision on the waste disposal type, and it includes the technological, mechanical, civil and financial documentation on the preliminary/basic design level. During the last few years, the preliminary design has been prepared and safety assessment conducted for the tunnel-type LL/IL rad waste repository. As the surface-type repository is one of alternatives for final disposal the design documentation for that repository type was prepared during 1994. (author)

  2. High level radioactive waste repositories. Task 3. Review of underground handling and emplacement. 1. Executive summary

    Energy Technology Data Exchange (ETDEWEB)

    1981-01-01

    A review is presented of proposals for transport, handling and emplacement of high-level radioactive waste in an underground repository appropriate to the U.K. context, with particular reference to waste block size and configuration; self-shielded or partially-shielded block; stages of disposal; transport by road/rail to repository site; handling techniques within repository; emplacement in vertical holes or horizontal tunnels; repository access by adit, incline or shaft; conventional and radiological safety; costs; and major areas of uncertainty requiring research or development.

  3. Groundwater-stream-simulation experiments for the evaluation of the safety of proposed nuclear waste repositories

    International Nuclear Information System (INIS)

    Seitz, M.G.

    1981-01-01

    A bench-scale experimental design which integrates repository components to simulate a groundwater stream infiltrating a breached repository is described in this paper. An experiment performed with a nuclear waste solid and one rock core is briefly summarized. The nuclear waste solid consists of borosilicate glass containing formulated nuclear waste and is the source of the leached radionuclides. The rock core used is of granite and serves as the adsorption medium for the leached radionuclides

  4. The recharge area concept: A strategy for siting nuclear waste repositories

    International Nuclear Information System (INIS)

    Sheng, G.; Toth, J.

    2000-01-01

    The Recharge Area Concept is the proposition that in Canadian-Shield type natural environments recharge areas of regional groundwater flow systems are superior for high-level nuclear waste repositories to other types of groundwater flow regimes, especially to areas of groundwater discharge. This conclusion is reached from an analysis of basinal groundwater flow models. The calculations were made for a two-dimensional flank of a fully saturated topographic basin, 20 km long and 4 km deep, in which groundwater is driven by gravity. Variants of hydraulic-conductivity distributions were considered: 1) homogeneous; 2) stratified; and 3) stratified-faulted. The faults attitudes were changed by steps from vertical to horizontal for different variants. The model is assumed conceptually to represent the crystalline-rock environment of the Canadian Shield. The hydrogeologic performances of hypothetical repositories placed 500 m deep in the recharge and discharge areas were characterized by thirteen parameters. The principal advantages of recharge- over discharge-area locations are: 1) longer travel paths and return-flow times from repository to surface; 2) robustness of predicted values of performance parameters; 3) field-verifiability of favourable hydrogeologic conditions (amounting to an implicit validation of the calculated minimum values of return-flow times); 4) site acceptance based on quantifiable and observable flow-controlling parameters; and 5) simple logistics and favourable economics of site selection and screening. As a by-product of modeling, it is demonstrated that the presence of old water is not an indication of stagnancy. (author)

  5. The role of waste package specifications as a forerunner to ILW repository conditions for acceptance

    International Nuclear Information System (INIS)

    Barlow, S.V.; Palmer, J.D.

    1998-01-01

    In the absence of a finalized repository site, design or associated safety case, Nirex is not in a position to issue conditions for acceptance. Nirex has therefore developed a strategy which facilitates packaging of intermediate level waste by providing guidance through waste package specifications, supported by the formal assessment of specific packaging proposals on a case-by-case basis. The waste package specifications are comprehensive and cover all aspects of the waste package including dimensions and other key features, performance standards, wasteform, quality assurance, and data recording requirements. The waste package specifications will be subject to periodic review as repository design and safety cases are finalized and will progressively become site- and design-specific. The waste package specifications will eventually form the basis for conditions for acceptance. The strategy described in this paper has been successfully followed by Nirex and customers for the past ten years and has permitted wastes to be packaged for a deep repository with confidence in the absence of a finalized site and safety cases for the repository. Because the process has its basis in a generic repository concept, it remains robust, despite the increased uncertainty following the March 1997 Secretary of State's decision, as to the siting and time-scale of a deep waste repository, and continues to be an important component of the UK's waste management strategy. (author)

  6. Radionuclide transport behavior in a generic geological radioactive waste repository.

    Science.gov (United States)

    Bianchi, Marco; Liu, Hui-Hai; Birkholzer, Jens T

    2015-01-01

    We performed numerical simulations of groundwater flow and radionuclide transport to study the influence of several factors, including the ambient hydraulic gradient, groundwater pressure anomalies, and the properties of the excavation damaged zone (EDZ), on the prevailing transport mechanism (i.e., advection or molecular diffusion) in a generic nuclear waste repository within a clay-rich geological formation. By comparing simulation results, we show that the EDZ plays a major role as a preferential flowpath for radionuclide transport. When the EDZ is not taken into account, transport is dominated by molecular diffusion in almost the totality of the simulated domain, and transport velocity is about 40% slower. Modeling results also show that a reduction in hydraulic gradient leads to a greater predominance of diffusive transport, slowing down radionuclide transport by about 30% with respect to a scenario assuming a unit gradient. In addition, inward flow caused by negative pressure anomalies in the clay-rich formation further reduces transport velocity, enhancing the ability of the geological barrier to contain the radioactive waste. On the other hand, local high gradients associated with positive pressure anomalies can speed up radionuclide transport with respect to steady-state flow systems having the same regional hydraulic gradients. Transport behavior was also found to be sensitive to both geometrical and hydrogeological parameters of the EDZ. Results from this work can provide useful knowledge toward correctly assessing the post-closure safety of a geological disposal system. © 2014, National Ground Water Association.

  7. Performance analysis of conceptual waste package designs in salt repositories

    International Nuclear Information System (INIS)

    Jansen, G. Jr.; Raines, G.E.; Kircher, J.F.

    1984-01-01

    A performance analysis of commercial high-level waste and spent fuel conceptual package designs in reference repositories in three salt formations was conducted with the WAPPA waste package code. Expected conditions for temperature, stress, brine composition, radiation level, and brine flow rate were used as boundary conditions to compute expected corrosion of a thick-walled overpack of 1025 wrought steel. In all salt formations corrosion by low Mg salt-dissolution brines typical of intrusion scenarios was too slow to cause the package to fail for thousands of years after burial. In high Mg brines judged typical of thermally migrating brines in bedded salt formations, corrosion rates which would otherwise have caused the packages to fail within a few hundred years were limited by brine availability. All of the brine reaching the package was consumed by reaction with the iron in the overpack, thus preventing further corrosion. Uniform brine distribution over the package surface was an important factor in predicting long package lifetimes for the high Mg brines. 14 references, 15 figures

  8. Durable concrete for a waste repository - Measurement of ionic ingress

    International Nuclear Information System (INIS)

    Feldman, R.F.; Beaudoin, J.J.; Philipose, K.E.

    1990-01-01

    A waste repository for the below ground disposal of low level radioactive waste is planned at Chalk River Nuclear Laboratories. It relies greatly on the durability of concrete for the required 500 year service life. A research program to design durable concrete and predict its service life is in progress. The degradation of the concrete depends to a large extent on the rate of ingress of corrosive agents. Penetration of chloride and sulfate ions are particularly relevant. Twenty mix formulations were developed to create various types and qualities of concrete, and to study their behavior in different site environmental conditions. A total of 1,000 concrete specimens are being exposed at 20C and 45C to 25 different combinations of the corrosive agents including CO 2 . Procedures to measure the ionic profiles and to determine the factors controlling diffusion of the ions in the various concretes have been developed. Results of selected concrete systems exposed to chloride and sulfate solutions for 1 year are presented and discussed in terms of pore structure and permeability parameters of the concrete

  9. Selection of candidate canister materials for high-level nuclear waste containment in a tuff repository

    International Nuclear Information System (INIS)

    McCright, R.D.; Weiss, H.; Juhas, M.C.; Logan, R.W.

    1983-11-01

    A repository located at Yucca Mountain at the Nevada Test Site is a potential site for permanent geological disposal of high-level nuclear waste. The repository can be located in a horizon in welded tuff, a volcanic rock, which is above the static water level at this site. The environmental conditions in this unsaturated zone are expected to be air and water vapor dominated for much of the containment period. Type 304L stainless steel is the reference material for fabricating canisters to contain the solid high-level wastes. Alternative stainless alloys are considered because of possible susceptibility of 304L to localized and stress forms of corrosion. For the reprocessed glass wastes, the canisters serve as the recipient for pouring the glass with the result that a sensitized microstructure may develop because of the times at elevated temperatures. Corrosion testing of the reference and alternative materials has begun in tuff-conditioned water and steam environments. 21 references, 8 figures, 8 tables

  10. Thermodynamic stability of actinide pyrochlore minerals in deep geologic repository environments

    International Nuclear Information System (INIS)

    Wang, YIFENG; Xu, HUIFANG

    2000-01-01

    Crystalline phases of pyrochlore (e.g., CaPuTi 2 O 7 , CaUTi 2 O 7 ) have been proposed as a durable ceramic waste form for disposal of high level radioactive wastes including surplus weapons-usable plutonium. In this paper, the authors use a linear free energy relationship to predict the Gibbs free energies of formation of pyrochlore phases (CaMTi 2 O 7 ). The Pu-pyrochlore phase is predicted to be stable with respect to PuO 2 , CaTiO 3 , and TiO 2 at room temperatures. Pu-pyrochlore is expected to be stable in a geologic repository where silica and carbonate components are absent or limited. The authors suggest that a repository in a salt formation be an ideal environment for disposal of high level, pyrochlore-based ceramic wastes. In such environment, adding CaO as a backfill will make pyrochlore minerals thermodynamically stable and therefore effectively prevent actinide release from these mineral phases

  11. Site selection for deep geologic repositories - Consequences for society, economy and environment; was kommt auf die regionen zu? Auswirkungen geologischer tiefenlager auf gesellschaft, wirtschaft und lebensraum

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-03-15

    In a few years, Switzerland will make the decision regarding site selection for geological underground repositories for the storage of radioactive wastes. Besides the safety issue, many citizens are interested in how such a repository will affect environment, economy and society in the selected site's region. This brochure summarizes the results of many studies on the socio-economic impacts of nuclear waste repositories. Radioactive wastes must be stored in such a way that mankind and environment are safely protected for a long period of time. How this goal may be achieved, is already known: geologic deep repositories warrant long-term safety. For the oncoming years in Switzerland the question is where the repository will be built. The search for an appropriate site for a repository in the proposed regions will launch discussions. Within the participative framework the regions may bring their requests. The demonstration of the safety of potential repository sites has the highest priority in the selection process. In the third procedural step additional rock investigations will be made. The socio-economic studies and the experience with existing plants show that radioactive waste management plants can be built and operated in good agreement with environmental requirements. The radioactive wastes in a deep underground repository are stored many hundred meters below the Earth's surface. There, they are isolated from our vital space. Technical barriers and the surrounding dense rock confinement prevent the release of radioactive materials into the environment. A deep repository has positive consequences for the regional economy. It increases trade and value creation and creates work places. The socio-economic impacts practically extend over one century, but strongly vary with time; they are the largest during the building period. High life quality and a positive population development in the selected site region are compatible with a deep repository. A fair

  12. A logistic and cost model for the transport of radioactive waste to a repository

    International Nuclear Information System (INIS)

    Hutchinson, D.L.; Gray, I.L.S.; Manville, W.D.

    1997-01-01

    UK Nirex Ltd is planning a deep repository for intermediate level radioactive waste, and also some low level waste. Part of this work is to develop a transport system to bring the packaged waste to the repository from nuclear industry sites across the United Kingdom. To assess the logistics and costs of this transport system and to provide inputs to the repository specification and design, Nirex has commissioned the development of a flexible computer model which can be used on a desktop PC. The requirements for the LOGCOST model are explained, and the solutions adopted, and then examples shown of the graphical and tabular outputs that LOGCOST can provide. (Author)

  13. Recharge-area nuclear waste repository in southeastern Sweden. Demonstration of hydrogeologic siting concepts and techniques

    International Nuclear Information System (INIS)

    Provost, A.M.; Voss, C.I.

    2001-11-01

    Nuclear waste repositories located in regional ground-water recharge ('upstream') areas may provide the safety advantage that potentially released radionuclides would have long travel time and path length, and large path volume, within the bedrock before reaching the biosphere. Nuclear waste repositories located in ground-water discharge ('downstream') areas likely have much shorter travel time and path length and smaller path volume. Because most coastal areas are near the primary discharge areas for regional ground-water flow, coastal repositories may have a lower hydrogeologic safety margin than 'upstream' repositories located inland. Advantageous recharge-area sites may be located through careful use of regional three-dimensional, variable-density, ground-water modeling. Because of normal limitations of site-characterization programs in heterogeneous bedrock environments, the hydrogeologic structure and properties of the bedrock will generally remain unknown at the spatial scales required for the model analysis, and a number of alternative bedrock descriptions are equally likely. Model simulations need to be carried out for the full range of possible descriptions. The favorable sites are those that perform well for all of the modeled bedrock descriptions. Structural heterogeneities in the bedrock and local undulations in water-table topography, at a scale finer than considered by a given model, also may cause some locations in favored inland areas to have very short flow paths (of only hundreds of meters) and short travel times, compromising the long times and paths (of many kilometers) predicted by the analysis for these sites. However, in the absence of more detailed modeling, the favored upstream sites offer a greater chance of achieving long times and paths than do downstream discharge areas, where times and paths are expected to be short regardless of the level of detail included in the model. As an example of this siting approach, potential repository

  14. The duration of the institutional controls on the low and intermediate level waste repositories

    International Nuclear Information System (INIS)

    Yang Jie; Li Yang; Liu Yafang; Lian Bing; Zhao Yangjun; Chen Hailong; Gu Zhijie

    2014-01-01

    Appropriate institutional controls are put in place prior to repository closure. Such controls can guarantee the long term safety of the repository. Today there is no clear standard on how to determine the institutional control period. This paper tries to give possible factors and activities of the institutional controls on the low and intermediate level waste repositories, and makes some suggestions on the institutional controls in our country. (authors)

  15. Environmental monitoring and radiation protection programs of Novi Han radioactive waste repository

    International Nuclear Information System (INIS)

    Christoskova, M.; Kostova, M.; Sheherov, L.; Bekiarov, P.; Iovtchev, M.

    2000-01-01

    The system for monitoring and control as an important part of the safety management of the Novi Han Radioactive Waste Repository contains two independent programs: environmental monitoring of the site (controlled area), the restricted access area and the surveillance area (supervised area) of the repository and radiation protection program including personal dosimetric control and indoor dosimetric control of workplaces in the buildings of the repository. The main activities related to the programs implementation are presented

  16. Site selection factors for repositories of solid high-level and alpha-bearing wastes in geological formations

    International Nuclear Information System (INIS)

    1977-01-01

    The purpose of this report is to provide guidelines for the selection and evaluation of suitable areas and sites for the disposal of solid high-level and alpha-bearing wastes into geological formations. This report is also intended to provide summary information on many types of geological formations underlying the land masses that might be considered as well as guidance on the geological and hydrological factors that should be investigated to demonstrate the suitability of the formations. In addition, other factors that should be considered in selecting a site for a radioactive waste repository are discussed briefly. The information, as presented, was developed to the extent of current technology for application to the evaluation of deep (greater than about 300 metres below ground level) geological formations in the selection of suitable areas for the disposal of solid or solidified high-level and alpha-bearing wastes. The extreme complexity of many geological environments and of the rock features that govern the presence and circulation of groundwater does not make it feasible to derive strict criteria for the selection of a site for a radioactive waste repository in a geological formation. Each potential repository location must be evaluated according to its own unique geological and hydrological setting. Therefore, only general guidance is offered, and this is done through discussion of the many factors that need to be considered in order to obtain the necessary assurances that the radionuclides will be confined in the geological repository over the required period of time

  17. Site selection factors for repositories of solid high-level and alpha-bearing wastes in geological formations

    Energy Technology Data Exchange (ETDEWEB)

    1977-01-01

    The purpose of this report is to provide guidelines for the selection and evaluation of suitable areas and sites for the disposal of solid high-level and alpha-bearing wastes into geological formations. This report is also intended to provide summary information on many types of geological formations underlying the land masses that might be considered as well as guidance on the geological and hydrological factors that should be investigated to demonstrate the suitability of the formations. In addition, other factors that should be considered in selecting a site for a radioactive waste repository are discussed briefly. The information, as presented, was developed to the extent of current technology for application to the evaluation of deep (greater than about 300 meters below ground level) geological formations in the selection of suitable areas for the disposal of solid or solidified high-level and alpha-bearing wastes. The extreme complexity of many geological environments and of the rock features that govern the presence and circulation of groundwater does not make it feasible to derive strict criteria for the selection of a site for a radioactive waste repository in a geological formation. Each potential repository location must be evaluated according to its own unique geological and hydrological setting. Therefore, only general guidance is offered, and this is done through discussion of the many factors that need to be considered in order to obtain the necessary assurances that the radionuclides will be confined in the geological repository over the required period of time.

  18. Development and application of a quality assurance system for waste repositories

    International Nuclear Information System (INIS)

    Beckmerhagen, I.; Berg, H.P.

    1996-01-01

    A large set of requirements are developed for the structures, systems and components of a waste repository. These requirements cover different regulations concerning planning, design, construction, operation and decommissioning of a waste repository as well as nuclear-specific requirements on the design of the plant. The implementation of a quality assurance (QA) system is an essential task in order to ensure that the requirements are fulfilled by systematic means. The QA system for the German repositories for radioactive waste is built up as a hierarchic system and described in more detail in particular covering aspects like maintenance of QA relevant systems, structures and components as well as the procedure in case of changes. For the operational phase of a repository a separate site-specific manual had to be developed. Such a manual has been elaborated for the operation of the Morsleben repository; main topics of this manual are presented

  19. Thermal analysis of a heat generating waste repository on the seabed

    International Nuclear Information System (INIS)

    Maynard, M.J.; Butler, T.P.; Firmin, G.H.

    1987-02-01

    The time dependent thermal behaviour of a repository containing heat generating waste has been investigated during loading, transport, and subsequent emplacement on the seabed. Variations of less than 1 0 C in the sealed repository water temperature were calculated to be sufficient to create adequate water circulation. Conservative 1-D analyses were used to estimate a maximum repository water temperature of 256 0 C, occuring about 3 years after emplacement. The temperature distributions within the heat generating waste canisters and grouted titanium tubes have been calculated using 2-D axisymmetric finite element models. Peak temperatures at the waste centre-line were found to be approx. 40 0 C above the repository water temperature. The sensitivity of the results to assumed thermal parameters and to the effect of sediment accumulation have been considered. The possibility and consequences of steam formation within a vented repository have been discussed. (author)

  20. Nuclear Waste State of the Art Report 2010 - challenges for the final repository programme

    International Nuclear Information System (INIS)

    2010-01-01

    In this year's report the Council calls for that SKB makes more studies of how the copper corrosion affects the long-term safety. SKB is criticized for not sufficiently set clear requirements for the bentonite clay, which should surround the copper canisters. Internationally possibility to take back spent fuel from the repository is one highly topical issue. Retrieval of waste for transmutation and future reuse of spent nuclear fuel should be discussed also in Sweden. It is estimated that SKB submit an application within one year to dispose of spent nuclear fuel in the 500 meter deep repository in the bedrock at Oesthammar. The mountain is the natural barrier between the nuclear fuel and the environment, and in addition to this, spent fuel is surrounded by two technical barriers: copper canisters and bentonite clay. The corrosion resistance of the copper canisters has recently been challenged by research from the Royal Institute of Technology, and this has created uncertainty over copper canister as a suitable barrier. The Council believes that SKB should actively contribute to investigate the issue of corrosion of copper in pure, oxygen-free water in a scientifically unassailable way, and that its potential effect is determined. Bentonite clay is the subject of intensive development work in SKB's new bentonite-laboratory, but the Council believes that SKB must set clearer requirements for bentonite clay quality, particularly with regard to thresholds for the contaminants that may occur. The question of what is possible and desirable in order retrieve the spent fuel from the repository is international discussed. Retrievability before closure is part of the safety requirements and is not controversial. Retrievability after sealing on the other hand, is both a controversial and complex issue, especially from a civil law perspective. New technology can make high-level waste as an interesting energy source, or use of the Partitioning and Transmutation can make the

  1. National radioactive waste repository site selection study. Phase 2. A report on public comment

    International Nuclear Information System (INIS)

    1995-11-01

    Agreement was reached in principle between State/Territory and the Commonwealth of Australia Governments that a suitable site for a radioactive wastes repository must be found. The discussion papers resulting from the Phase 1 and Phase 2 of the site selection study were released for public comment. The national repository will be for disposal of low level and short-lived intermediate level radioactive wastes streaming from the medical, research and industrial use of radioisotopes in Australia. The purpose of this report is to summarise and respond in general terms to comment received on the discussion paper -Phase 2 of the study. Forty five submissions were received. Of these: 18 supported the Phase 2 study approach and the concept of a national repository; 13 did not state a clear position but either requested more information or provided constructive comment on the siting process; 7 supported the site selection approach and the repository concept but suggested that the repository should not be sited in a particular area; 3 opposed the siting of the repository in their vicinity but not necessarily the repository concept and site selection approach; 4 opposed the concept of a national repository. This compares with 124 submissions on Phase 1 of the study, of which 57 opposed the national repository concept (52 of these were from letters elicited by Greenpeace) and 48 supported the establishment of a national repository and the site selection approach proposed. 3 figs

  2. A performance goal-based seismic design philosophy for waste repository facilities

    International Nuclear Information System (INIS)

    Hossain, Q.A.

    1994-02-01

    A performance goal-based seismic design philosophy, compatible with DOE's present natural phenomena hazards mitigation and ''graded approach'' philosophy, has been proposed for high level nuclear waste repository facilities. The rationale, evolution, and the desirable features of this method have been described. Why and how the method should and can be applied to the design of a repository facility are also discussed

  3. Thermodynamic coupling of heat and matter flows in near-field regions of nuclear waste repositories

    International Nuclear Information System (INIS)

    Carnahan, C.L.

    1983-11-01

    In near-field regions of nuclear waste repositories, thermodynamically coupled flows of heat and matter can occur in addition to the independent flows in the presence of gradients of temperature, hydraulic potential, and composition. The following coupled effects can occur: thermal osmosis, thermal diffusion, chemical osmosis, thermal filtration, diffusion thermal effect, ultrafiltration, and coupled diffusion. Flows of heat and matter associated with these effects can modify the flows predictable from the direct effects, which are expressed by Fourier's law, Darcy's law, and Fick's law. The coupled effects can be treated quantitatively together with the direct effects by the methods of the thermodynamics of irreversible processes. The extent of departure of fully coupled flows from predictions based only on consideration of direct effects depends on the strengths of the gradients driving flows, and may be significant at early times in backfills and in near-field geologic environments of repositories. Approximate calculations using data from the literature and reasonable assumptions of repository conditions indicate that thermal-osmotic and chemical-osmotic flows of water in semipermeable backfills may exceed Darcian flows by two to three orders of magnitude, while flows of solutes may be reduced greatly by ultrafiltration and chemical osmosis, relative to the flows predicted by advection and diffusion alone. In permeable materials, thermal diffusion may contribute to solute flows to a smaller, but still significant, extent

  4. Effects of gas overpressurisation on the geological environment of a deep repository

    International Nuclear Information System (INIS)

    Nash, P.J.; Rodwell, W.R.

    1990-04-01

    The effect of gas generated from the deep burial of low and intermediate level radioactive wastes is being assessed. Significant volumes of gas are expected to be produced by anaerobic corrosion of metals and microbial degradation of organic materials. Work is being carried out to determine how easily the gas generated can move away from the repository, since if its flow were impeded the pressure in the repository would rise. If the flow were sufficiently impeded then the pressure rise could ultimately lead to fracturing of the vault or the flow field environment, possibly providing pathways that could accelerate the movement of radionuclides to the surface. This study considers the effects of such an overpressurisation on the integrity of the geological environment containing the repository. It attempts to quantify the pore fluid pressures at which fracturing of hard rock masses may occur by investigating a number of models of rock failure in homogeneously stressed rock and the effects of the presence of an idealised vault on the stress field. A crack opening model has also been developed which considers the effect of the overpressurisation on the dimensions of existing cracks within the rock and hence on the value of its permeability. (Author)

  5. Impact of transporting defense high-level waste to a geologic repository

    International Nuclear Information System (INIS)

    Joy, D.S.; Shappert, L.B.; Boyle, J.W.

    1984-12-01

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425) provides for the development of repositories for the disposal of high-level radioactive waste and spent nuclear fuel and requires the Secretary of Energy to evaluate five potential repository sites. One factor that is to be examined is transportation of radioactive materials to such a repository and whether transportation might be affected by shipments to a defense-only repository, or to one that accepts both defense and commercial waste. In response to this requirement, The Department of Energy has undertaken an evaluation of the cost and risk associated with the potential shipments. Two waste-flow scenarios are considered which are related to the total quantity of defense high-level waste which will be placed in a repository. The low-flow case is based on a total of 6700 canisters being transported from one site, while the high-flow case assumes that a total of 20,000 canisters will be transported from three sites. For the scenarios considered, the estimated shipping costs range from $105 million to $257 million depending upon the mode of transport and the repository location. The total risks associated with shipping defense high-level waste to a repository are estimated to be significantly smaller than predicted for other transportation activities. In addition, the cost of shipping defense high-level waste to a repository does not depend on whether the site is a defense-only or a commercial repository. Therefore, the transportation considerations are not a basis for the selection of one of the two disposal options

  6. Technical, institutional and economic factors important for developing a multinational radioactive waste repository

    International Nuclear Information System (INIS)

    1998-06-01

    Countries planning and implementing nuclear energy programmes should assume responsibility for the safe management and final disposal of radioactive waste from their programmes. However, there are countries whose radioactive waste volumes do not easily justify a national repository, and/or countries which do not have the resources or favorable natural conditions for waste disposal to dedicate to a national repository project. These countries would benefit from multinational co-operation for the disposal. Interest in the concept of a multinational repository for radioactive waste has been expressed by several Member States and the waste management community in the light of the potential benefit to the partner countries from the safety, technical and economic standpoints. However, such an approach involves many political and public acceptance issues and therefore a consensus among countries or regions concerned is a prerequisite. In this context, it was deemed appropriate that the IAEA access the technical, institutional, ethical and economic factors to be taken into account in the process of such consensus building. This report is intended to provide an assessment which can serve as a general basis for establishing a waste management policy and/or further assessing specific issues such as ownership and liability, institutional aspects and problems related to long term commitments. This report is divided into five sections where the first section gives background, objectives, scope and structure of the report. Section 2 discusses multinational repository concept in terms of needs and the role of a multinational repository, interaction between host and partner countries and formulation of a multinational repository. Section 3 identifies basic issues to be considered for establishing a multinational repository, and some specific issues relating to specific waste categories. Section 4 analyses potential benefits and challenges to be addresses in establishing a

  7. Concentration Limits in the Cement Based Swiss Repository for Long-lived, Intermediate-level Radioactive Wastes (LMA)

    International Nuclear Information System (INIS)

    Berner, Urs

    1999-12-01

    The Swiss repository concept for long-lived, intermediate-level radioactive wastes (LMA), in Swiss terminology) foresees cylindrical concrete silos surrounded by a ring of granulated bentonite to deposit the waste. As one of the possible options and similar to the repository for high level wastes, the silos will be located in a deep crystalline host rock. Solidified with concrete in steel drums, the waste is stacked into a silo and the silo is then backfilled with a porous mortar. To characterize the release of radionuclides from the repository, the safety assessment considers first the dissolution into the pore water of the concrete, and then diffusion through the outer bentonite ring into the deep crystalline groundwater. For 19 safety relevant radionuclides (isotopes of U, Th, Pa, Np, Pu, Am, Ni, Zr, Mo, Nb, Se, Sr, Ra, Tc, Sn, I, C, Cs, Cl) the report recommends maximum elemental concentrations to be expected in the cement pore water of the particularly considered repository. These limits will form the parameter base for subsequent release model chains. Concentration limits in a geochemical environment are usually obtained from thermodynamic equilibrium calculations performed with geochemical speciation codes. However, earlier studies revealed that this procedure does not always lead to reliable results. Main reasons for this are the complexity of the systems considered, as well as the lacking completeness of, and the uncertainty associated with the thermodynamic data. To improve the recommended maximum concentrations for a distinct repository design, this work includes additional design- and system-dependent criteria. The following processes, inventories and properties are considered in particular: a) recent experimental investigations, particularly from cement systems, b) thermodynamic model calculations when reliable data are available, c) total inventories of radionuclides, d) sorption- and co-precipitation processes, e) dilution with stable isotopes, f

  8. Experience from developed and licensing an underground repository for low and intermediate level radioactive wastes

    International Nuclear Information System (INIS)

    Ebel, K.; Richter, D.

    1988-01-01

    In the German Democratic Republic an abandoned salt mine was selected and reconstructed to serve as a central repository for low and intermediate level wastes from nuclear power plants and radioisotope production and application from all over the country. The decision to establish such a repository was based on safety and technical-economic studies performed in the 1960s. The repository is owned by the main waste producer, the nuclear plant utility. It was designed, constructed and commissioned during 1972-1978. The licensing steps included a site licence (1972), a construction licence (1974), a comissioning licence and a continuous operation licence (1979). The paper reviews the overall choice of the disposal option, the responsibilities in radioactive waste management, the licensing and surveillance activities, the methods for transport and disposal, and the waste acceptance criteria established for the repository. (author)

  9. Leaching of vitrified high-level-active-waste in a near reality simulated repository system

    International Nuclear Information System (INIS)

    Froeschen, W.; Wolf, G.K.

    1987-01-01

    In the FRG it is planned to vitrify the high level waste from spent fuel reprocessing and to dispose of in a salt-mine. If water penetrates into the repository a highly corrosive brine (Q-brine) will be formed and radioactive material may be leached from the glasses and transported to human environment. The corrosion system of brine, corroded steel containers of the vitrified waste, and waste-glasses was investigated under near reality conditions. Experiments in hydrothermal environment were carried out including gamma radiation of the waste-glasses and ceramic In Can Lining between glasses and metallic containments. Screening experiments by application of external cobalt-gamma-radiation showed no principal changes in leaching behaviour of simulate glasses compared to leaching without radiation. Radiation effects result in pH changes mainly which are diminished by buffer capacity of Q-brine. Lining of steel containments with ceramic fleece does not reduce leaching but retards solution of Mo and Sr into brine. Decreasing of elements Sr, Cs and Mo in the near surface area of the glass and increasing of Zr and Ti has been found to be enhanced considerably in presence of canister corrosion products in Q-brine as well as in NaCl-leaching solution. (orig.) With 13 refs., 22 figs [de

  10. Regulation of waste packaging in the absence of a repository development programme

    International Nuclear Information System (INIS)

    Bennett, D.; Williams, C.R.

    2000-01-01

    The UK has a wide range of intermediate level wastes stored at a number of locations. There are various projects in place, or envisaged by operators, to retrieve, treat and condition these wastes for interim storage and eventual disposal. Currently UK government policy for the long-term management of intermediate level wastes (ILW) is under review following the rejection, in 1997, of a planning application for the establishment of an underground rock characterisation facility. Consequently there is currently considerable uncertainty on the future fate of these wastes - a position that will not change for several years. The recent loss of a repository development programme and consequent uncertainty on the timing and requirements for long term disposal is causing particular difficulties where operators are looking to make decisions in the short term on conditioned wasteforms. This paper discusses the problems caused by these uncertainties and the steps being taken by the Environment Agency to ensure so far as is practicable, having regard to the requirements for safe long-term storage, that future disposability of wastes is not jeopardised by actions taken in the short term. (author)

  11. Risk analysis of radioactive waste repository based on the time dependent hazard rate

    International Nuclear Information System (INIS)

    Chang, S.H.; Cho, W.J.

    1984-01-01

    For the probabilistic risk analysis of the radioactive high level waste repository, the simplified method based on the time dependent hazard rate is proposed. The obtained results are compared with those from the time independent hazard rate. The estimation of the failure probability of the waste repository through this method gives more conservative results, especially when the half-life of nuclide is larger and retardation factors of nuclide is smaller. (Auth.)

  12. Neotectonic movement feature in preselection area for high level radioactive waste repository

    International Nuclear Information System (INIS)

    Huang Xianfang; Gao Yang; He Jianguo; Li Jianzhong; Gao Honglei; Xu Guoqing

    2010-01-01

    Neotectonic activity intensity is an important criteria for evaluating high level radioactive waste repository. The guiding ideology, methods and application of neotectonic study are elaborated in the paper. According to comparison research between the south and north part of east Tianshan area, the south part of east Tianshan is regarded as relative stable or relative weak in neotectonic movement in Neogene period and was selected as preselection area for high level radioactive waste repository. (authors)

  13. Symposium on the development of nuclear waste policy: Siting the high-level nuclear waste repository

    International Nuclear Information System (INIS)

    Pijawka, K.D.; Mushkatel, A.H.

    1991-01-01

    The Nuclear Waste Policy Act of 1982 (NWPA) attempted to formulate a viable national policy for managing the disposal of high-level nuclear wastes. The NWPA authorized the selection of two repository sites: the first to be constructed in the West and a second site developed in the eastern United States. A detailed process for site selection was outlined in the NWPA. In addition, the NWPA authorized open-quotes the development of a waste transportation system; required the Department of Energy (DOE) to submit a proposal to construct a facility for monitored retrievable storage (MRS) after conducting a study of the need for, and feasibility of such a facility; and required the President to evaluate the use of the repositories ... for the disposal of high-level waste resulting from defense activitiesclose quotes (DOE, 1988, p. 1). A series of provisions granting oversight participation to states and Indian tribes, as well as a compensation package for the ultimate host state were also included. Responsibility for implementing the NWPA was assigned to DOE

  14. Progress on the national low level radioactive waste repository and national intermediate level waste store

    International Nuclear Information System (INIS)

    Perkins, C.

    2001-01-01

    Over the last few years, significant progress has been made towards siting national, purpose-built facilities for Australian radioactive waste. In 2001, after an eight year search, a preferred site and two alternatives were identified in central-north South Australia for a near-surface repository for Australian low level (low level and short-lived intermediate level) radioactive waste. Site 52a at Everts Field West on the Woomera Prohibited Area was selected as the preferred site as it performs best against the selection criteria, particularly with respect to geology, ground water, transport and security. Two alternative sites, Site 45a and Site 40a, east of the Woomera-Roxby Downs Road, were also found to be highly suitable for the siting of the national repository. A project has commenced to site a national store for intermediate (long-lived intermediate level) radioactive waste on Commonwealth land for waste produced by Commonwealth agencies. Public input has been sought on relevant selection criteria

  15. Effects of perched water on thermally driven moisture flow at the proposed Yucca Mountain repository for high-level waste

    International Nuclear Information System (INIS)

    Ofoegbu, G.I.; Bagtzoglou, A.C.; Green, R.T.; Muller, M.A.

    1999-01-01

    Numerical modeling was conducted to identify potential perched-water sites and examine the effects of perched water on thermally driven moisture flow at the proposed Yucca Mountain repository for high-level nuclear waste. It is demonstrated that perched-water zones may occur at two horizons on the up-dip side of faults such as the Ghost Dance Fault (GDF): in nonwelded volcanic strata [such as the Paintbrush Tuff nonwelded (PTn) stratigraphic unit], where juxtaposition of welded strata against nonwelded may constitute a barrier to lateral flow within the nonwelded strata; and in fractured horizons of underlying welded units [such as the Topopah Spring welded (TSw) unit] because of focused infiltration fed by overlying perched zones. The potential perched zones (PPZs) may contain perched water (which would flow freely into a well or opening) if infiltration rates are high enough. At lower infiltration rates, the PPZs contain only capillary-held water at relatively high saturations. Areas of the proposed repository that lie below PPZs are likely to experience relatively high percolation flux even if the PPZ contains only capillary-held water at high saturation. As a result, PPZs that contain only capillary-held water may be as important to repository performance as those that contain perched water. Thermal loading from emplaced waste in the repository is not likely to have an effect on PPZs located on adequate distance above the repository (such as in the PTn). As a result, such PPZs may be considered as permanent features of the environment. On the other hand, PPZs close to the repository depth (such as those that may occur in the TSw rock unit) would experience an initial period of spatial growth and increased saturation following waste emplacement. Thereafter, drying would begin at the repository horizon with perched-zone growth simultaneously above and below the repository. As a result, after the initial period of expansion, PPZs close to the repository horizon

  16. Main organic materials in a repository for high level radioactive waste

    International Nuclear Information System (INIS)

    Hallbeck, Lotta; Grive, Mireia; Gaona, Xavier; Duro, Lara; Bruno, Jordi

    2007-11-01

    A compilation of the origin and composition of organic material possibly left in a repository is made. Recommendations of precautions and actions for the different material are listed as well. As a brief summary, the different categories of organic material of relevance for the repository are: 1. Microorganisms. Their effect would be mainly a reduction of the redox potential in the initial stages after the repository closure. They may contribute to the depletion of the oxygen entrapped due to the repository construction. This effect would not jeopardize the stability of the repository. If the dominating microorganisms in the anaerobic environment are sulphate-reducing bacteria, oxidation of organic material would lead to formation of HS - . The produced sulphide can corrode copper under anaerobic conditions, if it reaches the canisters. Another effect of microorganisms would be the increase of the complexing capacity of the groundwater due to excreted metabolites. The impact of these compounds is not yet clear, although it will surely not be very important, due to the low amounts of the excreted substances. 2. Materials in the ventilation air. Their effect will probably be a contribution to the maintenance of reducing conditions in the area, although it is likely that this effect will be minimal or negligible. 3. Construction materials. Among them we can highlight organic materials present in concrete, asphalt, bentonite and wood. The most important compounds from the repository safety perspective will be those hydrocarbons from asphalt that may contribute to decreasing the redox potential around the repository, and the products of degradation of cellulose. This last category of compounds may contribute to enhance the complexing capacity of the groundwater around the repository and it is recommended to minimize the amount of cellulose left in the repository. 4. Fuels and engine emissions. No important effects from these organics in the repository are expected

  17. Main organic materials in a repository for high level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Hallbeck, Lotta [Vita vegrandis, Hindaas (Sweden); Grive, Mireia; Gaona, Xavier; Duro, Lara; Bruno, Jordi [Enviros Consulting, Valldoreix, Barcelona (Spain)

    2007-11-15

    A compilation of the origin and composition of organic material possibly left in a repository is made. Recommendations of precautions and actions for the different material are listed as well. As a brief summary, the different categories of organic material of relevance for the repository are: 1. Microorganisms. Their effect would be mainly a reduction of the redox potential in the initial stages after the repository closure. They may contribute to the depletion of the oxygen entrapped due to the repository construction. This effect would not jeopardize the stability of the repository. If the dominating microorganisms in the anaerobic environment are sulphate-reducing bacteria, oxidation of organic material would lead to formation of HS{sup -}. The produced sulphide can corrode copper under anaerobic conditions, if it reaches the canisters. Another effect of microorganisms would be the increase of the complexing capacity of the groundwater due to excreted metabolites. The impact of these compounds is not yet clear, although it will surely not be very important, due to the low amounts of the excreted substances. 2. Materials in the ventilation air. Their effect will probably be a contribution to the maintenance of reducing conditions in the area, although it is likely that this effect will be minimal or negligible. 3. Construction materials. Among them we can highlight organic materials present in concrete, asphalt, bentonite and wood. The most important compounds from the repository safety perspective will be those hydrocarbons from asphalt that may contribute to decreasing the redox potential around the repository, and the products of degradation of cellulose. This last category of compounds may contribute to enhance the complexing capacity of the groundwater around the repository and it is recommended to minimize the amount of cellulose left in the repository. 4. Fuels and engine emissions. No important effects from these organics in the repository are expected

  18. The use of uranium fluxes as safety indicators of radioactive waste repositories

    International Nuclear Information System (INIS)

    Miller, W.M.; Hooker, P.J.

    2002-01-01

    Natural analogues based on uranium deposits are commonly used to represent the long-term behaviour of radioactive waste repositories or the processes that influence their radioactive contents. The geochemical dispersion of naturally occurring uranium can also be used to model natural radioactivity fluxes in the vicinity of a planned repository. These fluxes can be estimated for erosional and groundwater discharge processes and compared with calculated future fluxes of radioactivity that would be released from a repository. The methodology is outlined and the benefits of the approach for supporting the derivation of a safety case for a repository are indicated. (author)

  19. The waste isolation pilot plant: A new regulatory environment

    International Nuclear Information System (INIS)

    Frei, M.W.; Schneider, S.P.; Saris, E.C.; Austin, P.W.

    1993-01-01

    The US Department of Energy (DOE) is ready to embark on a multiyear test program, using radioactive waste, at the Waste Isolation Pilot Plant (WIPP). The WIPP is a deep geologic repository, constructed in ancient salt beds in southeastern New Mexico. It was authorized by Congress in 1979 as a research and development facility to demonstrate safe disposal of the nation's defense transuranic (TRU) waste. Nonradioactive testing in the repository has been under way for several years. The DOE is now ready to begin underground experiments at WIPP with small amounts of TRU waste. Radioactive waste testing in an actual repository environment will reduce uncertainties associated with predictions of long-term repository performance. However, the authority for DOE to begin this new phase of the test program no longer resides within the department. The WIPP is now subject to a new level of regulatory oversight by the Environmental Protection Agency (EPA) and other federal agencies, as set forth by Public Law 102-579, the WIPP Land Withdrawal Act, signed by the President on October 30, 1992. This paper discusses the act's new regulatory requirements for WIPP

  20. Acceptance of waste for disposal in the potential United States repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Stahl, D.; Svinicki, K.

    1996-01-01

    This paper addresses the process for the acceptance of waste into the waste management system (WMS) with a focus on the detailed requirements identified from the Waste Acceptance System Requirements Document. Also described is the recent dialogue between OCRWM and the Office of Environmental Management to resolve issues, including the appropriate interpretation and application of regulatory and system requirements to DOE-owned spent fuel. Some information is provided on the design of the repository system to aid the reader in understanding how waste that is accepted into the WMS is received and emplaced in the repository

  1. Functions of an engineered barrier system for a nuclear waste repository in basalt

    International Nuclear Information System (INIS)

    Coons, W.E.; Moore, E.L.; Smith, M.J.; Kaser, J.D.

    1980-01-01

    Defined in this document are the functions of components selected for an engineered barrier system for a nuclear waste repository in basalt. The definitions provide a focal point for barrier material research and development by delineating the purpose and operative lifetime of each component of the engineered system. A five-component system (comprised of waste form, canister, buffer, overpack, and tailored backfill) is discussed in terms of effective operation throughout the course of repository history, recognizing that the emplacement environment changes with time. While components of the system are mutually supporting, redundancy is provided by subsystems of physical and chemical barriers which act in concert with the geology to provide a formidable barrier to transport of hazardous materials to the biosphere. The operating philosophy of the conceptual engineered barrier system is clarified by examples pertinent to storage in basalt, and a technical approach to barrier design and material selection is proposed. A method for system validation and qualification is also included which considers performance criteria proposed by external agencies in conjunction with site-specific models and risk assessment to define acceptable levels of system performance

  2. Creep in crystalline rock with application to high level nuclear waste repository

    International Nuclear Information System (INIS)

    Eloranta, P.; Simonen, A.

    1992-06-01

    The time-dependent strength and deformation properties of hard crystalline rock are studied. Theoretical models defining the phenomena which can effect these properties are reviewed. The time- dependent deformation of the openings in the proposed nuclear waste repository is analysed. The most important factors affecting the subcritical crack growth in crystalline rock are the stress state, the chemical environment, temperature and microstructure of the rock. There are several theoretical models for the analysis of creep and cyclic fatigue: deformation diagrams, rheological models thermodynamic models, reaction rate models, stochastic models, damage models and time-dependent safety factor model. They are defective in describing the three-axial stress condition and strength criteria. In addition, the required parameters are often too difficult to determine with adequate accuracy. Therefore these models are seldom applied in practice. The effect of microcrack- driven creep on the stability of the work shaft, the emplacement tunnel and the capsulation hole of a proposed nuclear waste repository was studied using a numerical model developed by Atomic Energy of Canada Ltd. According to the model, the microcrack driven creep progresses very slowly in good quality rock. Poor rock quality may accelerate the creep rate. The model is very sensitive to the properties of the rock and secondary stress state. The results show that creep causes no stability problems on excavations in good rock. The results overestimate the effect of the creep, because the analysis omitted the effect of support structures and backfilling

  3. Sandia studies of high-level waste canisters and overpacks applicable for a salt repository

    International Nuclear Information System (INIS)

    Molecke, M.A.; Schaefer, D.W.; Glass, R.S.; Ruppen, J.A.

    1982-01-01

    An experimental program to develop candidate materials for use as high-level waste (HLW) overpacks or canisters in a salt repository has been in progress at Sandia National Laboratories since 1976. The main objective of this program is to provide a waste package barrier having a long lifetime in the chemical and physical environment of a repository. This paper summarizes the recent corrosion and metallurgical study results for the prime overpack material, TiCode-12, in the areas of uniform corrosion (extremely low rate and extent); local attack, e.g., pits and crevices (none were found); stress corrosion cracking susceptibility (no significant changes in macroscopic tensile properties were detected); hydrogen sorption-embrittlement effects; effects of gamma irradiation in solution; and sensitization effects (testing is still in process in the last three areas). Previous candidate screening analyses on other alloys and recent work on alternate overpack alloys are reviewed. All phases of these interrelated laboratory, hot-cell, and field experimental studies are described. 16 references, 8 figures, 4 tables

  4. Special features of nuclear waste repository ventilation system VIS-A-VIS experiences at the Waste Isolation Pilot Plant

    International Nuclear Information System (INIS)

    Sethi, S.C.

    1991-01-01

    The paper presents an analysis and discussion of the underground ventilation system at the Waste Isolation Pilot Plant (WIPP). Particular emphasis is placed on specific repository-related requirements and the gradual evolution of engineering designs relative to the WIPP Project scope. The ventilation system for a nuclear waste facility similar to WIPP is designed to provide a suitable environment for personnel and equipment during normal activities. It is also designed to provide confinement and channeling of potential airborne radioactive material in the event of an accidental release. It is desirable to identify and design all parallel activities and the required process equipment prior to completion of the repository mine final design. Such factors as ventilation requirements, drift sizes, bulkhead sizes, and placement are dependent on these items. Mine creep closure properties must be factored into the mine and ventilation equipment design considerations. Effects of natural ventilation pressures deserve due consideration in the design. Mine ventilation requirements are dominated by the diesel equipment to be operated in the underground horizon. WIPP engineers have also found it extremely desirable to have automated real-time monitoring and control for the underground ventilation air. Final testing and balancing of the ventilation system is an extremely important startup requirement. 3 refs., 2 figs

  5. Bases for an environmental liability management system: application to a repository for radioactive waste

    International Nuclear Information System (INIS)

    Tostes, Marcelo Mallat

    1999-03-01

    This thesis aims the establishment of conceptual bases for the development of Environmental Liability Management System - instruments designed to provide financial and managerial coverage to financial liabilities arising from activities that impact the environment. The document analyses the theories that link the evolution of economic thought and environment, as a means of establish the necessary framework for the development of up-to-date environmental policy instruments. From these concepts and from the analysis of environmental liability system being implemented in several countries, the bases for environmental liability systems development are drawn. Finally, a study is carried out on the application of these bases for the development of an environmental liability management system for a radioactive waste repository. (author)

  6. Effects on the environment of the dumping of nuclear wastes

    International Nuclear Information System (INIS)

    1990-07-01

    Nationally and internationally accepted procedures and technologies are available for the safe handling and disposal of radioactive wastes. Authorized waste disposal practices are designed to ensure that there will be no significant impacts on man and his environment. 'Dumping' of nuclear wastes may result in the elimination of one or more of the multibarriers of protection inherent in an effective radioactive waste management system, thereby increasing the risk of radiological exposure to man and his environment. Quantitative assessments of the degree of environmental contamination and of the resulting hazards to man depend on the specific conditions surrounding the 'uncontrolled disposal' of radioactive waste. These include the nature and activity level of the waste, the physical form of the waste, the package that the waste is contained in and the characteristics of the dumping site. Depending on the scenario envisaged, the consequences of 'uncontrolled disposal' could vary from being insignificant to a situation where there is a significant hazard to an exposed population group. International transactions involving nuclear wastes are taking place between countries on the basis of bilateral agreements and under strict regulatory supervision so that radioactive wastes are transferred safely from one controlled area to another. Such transactions may increase in the future with increased international co-operation in sharing common waste repositories. No evidence exists that confirms that transboundary dumping of radioactive waste has occurred. Investigation of alleged dumping of radioactive wastes by the International Atomic Energy Agency has revealed that the 'suspect wastes' did not contain radioactive material. 2 tabs

  7. Chemical variability of zeolites at a potential nuclear waste repository, Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Broxton, D.E.

    1985-01-01

    The compositions of clinoptilolites and their host tuffs have been examined by electron microprobe and x-ray fluorescence, respectively, to determine their variability at a potential nuclear waste repository, Yucca Mountain, Nevada. Because of their sorptive properties, these zeolites could provide important geologic barriers to radionuclide migration. Variations in clinoptilolite composition can strongly affect the mineral's thermal and ion-exchange properties, thus influencing its behavior in the repository environment. Clinoptilolites and heulandites closest to the proposed repository have calcium-rich compositions (60 to 90 mol. % Ca) and silica-to-aluminum ratios that concentrate between 4.0 and 4.6. In contrast, clinoptilolites and their host tuffs deeper in the volcanic sequence have highly variable compositions that vary vertically and laterally. Deeper-occurring clinoptilolites in the eastern part of Yucca Mountain are characterized by calcic-potassic compositions and tend to become more calcium-rich with depth. Clinoptilolites at equivalent stratigraphic levels on the western side of Yucca Mountain have sodic-potassic compositions and tend to become more sodium-rich with depth. Despite their differences in exchangeable cation compositions these two deeper-occurring compositional suites have similar silica-to-aluminum ratios, concentrating between 4.4 and 5.0. The chemical variability of clinoptilolites and their host tuffs at Yucca Mountain suggest that their physical and chemical properties will also vary. Compositionally-dependent clinoptilolite properties important for repository performance assessment include expansion/contraction behavior, hydration/dehydration behavior, and ion-exchange properties

  8. Planning and Design Considerations for Geological Repository Programmes of Radioactive Waste

    International Nuclear Information System (INIS)

    2014-11-01

    Disposal in a geological repository is the generally accepted solution for the long term management of high level and/or long lived radioactive wastes, in line with the general principles defined in the IAEA Safety Fundamentals. This publication presents practical information on the way a geological repository programme for radioactive waste could be defined and planned, with special attention to all aspects having an impact on the timing. Country specific examples for repository development phases are provided, based on actual experiences from Member States

  9. Development of database systems for safety of repositories for disposal of radioactive wastes

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Yeong Hun; Han, Jeong Sang; Shin, Hyeon Jun; Ham, Sang Won; Kim, Hye Seong [Yonsei Univ., Seoul (Korea, Republic of)

    1999-03-15

    In the study, GSIS os developed for the maximizing effectiveness of the database system. For this purpose, the spatial relation of data from various fields that are constructed in the database which was developed for the site selection and management of repository for radioactive waste disposal. By constructing the integration system that can link attribute and spatial data, it is possible to evaluate the safety of repository effectively and economically. The suitability of integrating database and GSIS is examined by constructing the database in the test district where the site characteristics are similar to that of repository for radioactive waste disposal.

  10. A review of construction techniques available for surface and underground radioactive waste repositories

    International Nuclear Information System (INIS)

    Godfrey, D.G.; Davies, I.L.; MacKenzie, R.D.

    1985-01-01

    In terms of engineering requirements the construction of surface or indeed underground radioactive waste repositories is not unduly difficult. The civil engineering techniques likely to be required have generally been carried out previously, albeit not in the context of radioactive waste repositories in this country. The emphasis will have to be very much on the quality of construction. This paper emphasises the need for quality construction and describes the techniques likely to be used in the construction of repositories. Reference is made to the materials likely to be used in the construction of repositories and also to the need for being able to convince the designers, regulating authorities and the general public that the materials used will indeed last for the required time. Brief reference is made at the end of the paper to the civil engineering parameters requiring consideration in the location of repository siting. (author)

  11. Release consequence analysis for a hypothetical geologic radioactive waste repository in hard rock

    International Nuclear Information System (INIS)

    1979-12-01

    This report makes an evaluation of the long-term behaviour of the wastes placed in a hard rock repository. Impacts were analyzed for the seven reference fuel cycles of WG 7. The reference repository for this study is for granitic rock or gneiss as the host rock. The descriptions of waste packages and repository facilities used in this study represent only one of many possible designs based on the multiple barriers concept. The repository's size is based on a nuclear economy producing 100 gigawatts of electricity per year for 1 year. The objective of the modeling efforts presented in this study is to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere and thus determine an estimate of the potential dose to humans so that the release consequence impacts of the various fuel cycles can be compared. Currently available hydrologic, leach, transport, and dose models were used in this study

  12. A reliability study on influence of the geosphere thickness over the activity release from a near surface radioactive waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Aguiar, Lais Alencar de, E-mail: laguiar@cnen.gov.br [Comissao Nacional de Energia Nuclear (CNEN-RJ), Rio de Janeiro, RJ (Brazil); Damaso, Vinicius Correa, E-mail: vcdamaso@gmail.com [Estado-Maior do Exercito (EME/EB), Brasilia, DF (Brazil)

    2013-07-01

    Infiltration of water into a waste disposal facility and into the waste region is the main factor inducing the release of radionuclides from a disposal facility. Since infiltrating water flow is dependent on the natural percolation at the site and the performance of engineered barriers, its prediction requires modelling of unsaturated water flow through intact or partially/completely failed components of engineered barriers and through the rock layer of the geosphere on which the repository is constructed. The engineered barriers include the cover systems, concrete vault, backfill, waste forms, and overpacks. This paper aims to carry out a performance study regarding a near surface repository in terms of reliability engineering. It is assumed that surface water infiltrates through the barriers reaching the matrix where radionuclides are contained, thus releasing them into the environment. The repository consists of a set of barriers which are considered saturated porous medium. As results, this paper presents the relation between the thickness of the geosphere layer and the radionuclide release rate in terms of activity. Such results represent a useful information for choosing the repository sites in order to keep the released activity in acceptable levels over time. (author)

  13. A reliability study on influence of the geosphere thickness over the activity release from a near surface radioactive waste repository

    International Nuclear Information System (INIS)

    Aguiar, Lais Alencar de; Damaso, Vinicius Correa

    2013-01-01

    Infiltration of water into a waste disposal facility and into the waste region is the main factor inducing the release of radionuclides from a disposal facility. Since infiltrating water flow is dependent on the natural percolation at the site and the performance of engineered barriers, its prediction requires modelling of unsaturated water flow through intact or partially/completely failed components of engineered barriers and through the rock layer of the geosphere on which the repository is constructed. The engineered barriers include the cover systems, concrete vault, backfill, waste forms, and overpacks. This paper aims to carry out a performance study regarding a near surface repository in terms of reliability engineering. It is assumed that surface water infiltrates through the barriers reaching the matrix where radionuclides are contained, thus releasing them into the environment. The repository consists of a set of barriers which are considered saturated porous medium. As results, this paper presents the relation between the thickness of the geosphere layer and the radionuclide release rate in terms of activity. Such results represent a useful information for choosing the repository sites in order to keep the released activity in acceptable levels over time. (author)

  14. Preliminary site characterization at Beishan northwest China-A potential site for China's high-level radioactive waste repository

    International Nuclear Information System (INIS)

    Wang Ju; Su Rui; Xue Weiming; Zheng Hualing

    2004-01-01

    Chinese nuclear power plants,radioactive waste and radioactive waste disposal are introduced. Beishan region (Gansu province,Northwest China)for high-level radioactive waste repository and preliminary site characterization are also introduced. (Zhang chao)

  15. Chemical conditions in the repository for low- and intermediate-level reactor waste

    International Nuclear Information System (INIS)

    Snellman, M.; Uotila, H.

    1984-01-01

    The chemical conditions in the proposed repositories for low- and intermediate-level reactor waste at Haestholmen (IVO) and Olkiluoto (TVO) have been discussed with respect to materials introduced into the repository, their possible long-term changes and interaction with groundwater flowing into the repository. The main possible groundwater-rock interactions have been discussed, as well as the role of micro-organisms, organic acids and colloids in the estimation of the barrier integrity. Experimental and theoretical studies have been performed on the basis of the natural groundwater compositions expected at the repository sites. Main emphasis is put on the chemical parameters which might influence the integrity of the different barriers in the repository as well as on the parameters which might effect the release and transport of radionuclides from the repository

  16. Formulation and evaluation of gas release scenarios for the silo in Swedish Final Repository for Radioactive Waste (SFR)

    International Nuclear Information System (INIS)

    Carlsson, J.; Moreno, L.

    1992-01-01

    The Swedish Final Repository for Radioactive Waste (SFR) has been in operation since 1988 and is located in the crystalline rock, 60 m below the Baltic Sea. In the licensing procedure for the SFR the safety assessment has been complemented with a detailed scenario analysis of the performance of the repository. The scenarios include the influence on radionuclide release by gas formation and gas transport processes in the silo. The overall conclusion is that the release of most radionuclides from the silo is only marginally affected by the formation and release of gas, even for scenarios considering unexpected events. The largest effects were found for short-lived radionuclides and radionuclides that have no or low sorption ability. Except for very extreme scenarios for the silo the overall impact from repository on the environment is by far dominated by the release of radionuclides from the rock vaults. 10 refs., 6 figs

  17. Scientific studies in support of the Waste Isolation Pilot Plant (WIPP) repository

    International Nuclear Information System (INIS)

    Chu, M.S.Y.; Weart, W.D.

    1996-01-01

    The DOE submitted a Compliance Certification Application for WIPP in october, 1996. A critical part of this application was a Performance Assessment which predicts the cumulative radioactive release to the accessible environment over a time period of 10,000 years. Comparison of this predicted release to the EPA standard shows a comfortable margin of compliance. The scientific understanding that was critical to developing this assessment spans a broad range of geotechnical disciplines, and required a thorough understanding of the site's geology and hydrology. Evaluation of the geologic processes which are active in the site region establishes that there will be no natural breach of site integrity for millions of years, far longer than the 10,000 year regulatory period. Inadvertent human intrusion is, therefore, the only credible scenario to lead to potential radioactive release to the accessible environment. To substantiate this conclusion and to quantify these potential releases from human intrusion, it has been necessary to develop an understanding of the following processes: salt creep and shaft seal efficacy; gas generation from organic decomposition of waste materials and anoxic corrosion of metals in the waste and waste packages; solubilities for actinides in brine; fluid flow in Salado formation rocks, and hydrologic transport of actinides in the overlying dolomite aquifers. Other issues which had to be evaluated to allow definition of breach scenarios were brine reservoir occurrences and their associated reservoir parameters, consequences of mining over the repository, and drilling for natural resources in the vicinity of the repository. Results of all these studies will be briefly summarized in this paper

  18. Science is the first step to siting nuclear waste repositories

    Science.gov (United States)

    Neuzil, Christopher E.

    2014-01-01

    As Shaw [2014] notes, U.S. research on shale as a repository host was halted before expending anything close to the effort devoted to studying crystalline rock, salt, and - most notably - tuff at Yucca Mountain. The new political reality regarding Yucca Mountain may allow reconsideration of the decision to abandon research on shale as a repository host.

  19. Technical conservatisms in NWTS repository conceptual designs. National Waste Terminal Storage Repository No. 1: special study No. 4

    International Nuclear Information System (INIS)

    1980-09-01

    Prior studies have developed conceptual designs for National Waste Terminal Storage Repositories 1 and 2. Due to the considerable detail and volume of the documents describing these designs, it is often difficult to identify and comprehend the substantial conservatisms contained within them. This study identifies and explains the major technical conservatisms in these two conceptual designs in a concise and readily understandable format. The areas discussed include thermal loading of the geologic structure, rock mechanics and underground design, waste throughput capacity, hoisting systems, nuclear criticality safety, confinement of radioactive materials, occupational exposure and health physics, environmental effects, and cost estimates. Conservatisms are described in detail, quantified where possible, and compared to appropriate criteria

  20. Operational experience from SFR - Final repository for low- and intermediate level waste in Sweden

    International Nuclear Information System (INIS)

    Skogsberg, Marie; Ingvarsson, Roger

    2006-01-01

    SFR, the Swedish Final Repository for Radioactive Waste, has been in operation since April 1988. It was designed for short lived LLW/ILW from the operation and maintenance of all Swedish Nuclear Power Plants. The first stage was constructed for 63 000 m 3 which was assumed to give a margin and flexibility for the preliminary operational period. Today this volume represents the whole prediction of operational waste. Until the end of 2005 SFR has received 30 930 m 3 waste. In average it has been 2-3 derivations per year at the repository. The most derivations happened in the years 1993-1995, and that was also the years when the repository received the most volume of waste. The most of the derivations those years was related to the waste packages. The dose rate to the personal has always been very low in the latest years the collective dose has been under 0,1 mmanSv/year. (author)

  1. Analysis of the seismic hazard to an underground waste repository

    International Nuclear Information System (INIS)

    Wight, L.H.

    1979-01-01

    Conclusions are: The consequence associated with intense vibratory shaking of a well-designed repository is essentially negligible. The specification of an appropriate seismic vibratory design criteria could best be accomplished with a Bayesian seismic hazard assessment, using geologic slip rates as input. The consequence associated with fault displacement is very site specific and dependent on the host geologic media and its permeability changes in response to fault displacement. The probability of faulting through a repository in its million year design life is rather high, principally because of a high probability of primary or secondary faulting on undetected faults. The faulting probability can be minimized by deploying sophisticated site certification programs. High resolution microseismic surveillance seems to be most appropriate. The author's judgement is that the repository simulation program can neglect consequences associated with shaking of the repository, but that the probability of significant fault displacement through the repository during its design life should be conservatively taken as one

  2. The conceptual design of waste repository for radioactive waste from medical, industrial and research facilities containing comparatively high radioactivity

    International Nuclear Information System (INIS)

    Yamamoto, Masayuki; Hashimoto, Naro

    2002-02-01

    Advisory Committee on Nuclear Fuel Cycle Backend Policy reported the basic approach to the RI and Institute etc. wastes on March 2002. According to it, radioactive waste form medical, industrial and research facilities should be classified by their radioactivity properties and physical and chemical properties, and should be disposed in the appropriate types of repository with that classification. For the radioactive waste containing comparatively high radioactivity generated from reactors, NSC has established the Concentration limit for disposal. NSC is now discussing about the limit for the radioactive waste from medical, industrial and research facilities containing comparatively high radioactivity. Japan Nuclear Cycle Development Institute (JNC) preliminary studied about the repository for radioactive waste from medical, industrial and research facilities and discussed about the problems for design on H12. This study was started to consider those problems, and to develop the conceptual design of the repository for radioactive waste from medical, industrial and research facilities. Safety assessment for that repository is also performed. The result of this study showed that radioactive waste from medical, industrial and research facilities of high activity should be disposed in the repository that has higher performance of barrier system comparing with the vault type near surface facility. If the conditions of the natural barrier and the engineering barrier are clearer, optimization of the design will be possible. (author)

  3. Corporate knowledge repository: Adopting academic LMS into corporate environment

    Science.gov (United States)

    Bakar, Muhamad Shahbani Abu; Jalil, Dzulkafli

    2017-10-01

    The growth of Knowledge Economy has transformed human capital to be the vital asset in business organization of the 21st century. Arguably, due to its white-collar nature, knowledge-based industry is more favorable than traditional manufacturing business. However, over dependency on human capital can also be a major challenge as any workers will inevitably leave the company or retire. This situation will possibly create knowledge gap that may impact business continuity of the enterprise. Knowledge retention in the corporate environment has been of many research interests. Learning Management System (LMS) refers to the system that provides the delivery, assessment and management tools for an organization to handle its knowledge repository. By using the aspirations of a proven LMS implemented in an academic environment, this paper proposes LMS model that can be used to enable peer-to-peer knowledge capture and sharing in the knowledge-based organization. Cloud Enterprise Resource Planning (ERP), referred to an ERP solution in the internet cloud environment was chosen as the domain knowledge. The complexity of the Cloud ERP business and its knowledge make it very vulnerable to the knowledge retention problem. This paper discusses how the company's essential knowledge can be retained using the LMS system derived from academic environment into the corporate model.

  4. Climate Considerations in Long-Term Safety Assessments for Nuclear Waste Repositories

    Energy Technology Data Exchange (ETDEWEB)

    Naeslund, Jens-Ove; Brandefelt, Jenny; Claesson Liljedahl, Lillemor [Svensk Kaernbraenslehantering AB, Stockholm (Sweden)], E-mail: jens-ove.naslund@skb.se

    2013-05-15

    For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

  5. Judicial progress in Germany's nuclear waste disposal policy the Konrad repository decisions of 26 march 2007

    International Nuclear Information System (INIS)

    Kuhne, G.

    2007-01-01

    Its exists three final repository sites in Germany, an overview of the status of these sites is necessary to understand concretely the situation. Morsleben, is actually the only final repository for low and medium level radioactive waste. Gorleben is the site of a salt dome which is under exploration as an eventual repository for high level radioactive waste but the study is under a decree of exploration moratorium of at least three years, in order to allow for investigation into conceptual and safety issues. The Konrad ore mine is the site under preparation for a final repository for low and medium level radioactive waste. The present article will briefly address three aspects of the court reasoning: the legal character of the plan approval notice (act of discretion or strict execution of laws), the necessity of planning and safety aspects. (N.C.)

  6. Coupled thermo-hydro-mechanical processes associated with a radioactive waste repository

    International Nuclear Information System (INIS)

    Tsang, C.F.

    1988-01-01

    The performance assessment of a nuclear waste geologic repository presents a scientific and technical problem of a scope far beyond the evaluation of most civil and geologic constructions. First performance prediction must be made for tens of thousands of years, and a secondly, in calculating potential leakage rates from a repository to the biosphere the authors must determine not only the mean or average travel time but also the shorter travel times of low concentrations. These two criteria demand an understanding of all significant physical and chemical processes likely to occur around a nuclear waste repository. In particular, processes coupling thermal transfer fluid flow, mechanical deformation and chemical reactors, which may be slow in a laboratory time scale, may become very important. This paper gives a general survey on the subject, with specific examples of a number of relevant coupled thermo-hydro-mechanical processes associated with nuclear waste repository

  7. Climate considerations in long-term safety assessments for nuclear waste repositories.

    Science.gov (United States)

    Näslund, Jens-Ove; Brandefelt, Jenny; Liljedahl, Lillemor Claesson

    2013-05-01

    For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

  8. Performance analysis of a repository for low and intermediate level reactor waste

    International Nuclear Information System (INIS)

    Vieno, T.; Nordman, H.; Vuori, S.; Peltonen, E.

    1987-01-01

    In Finland, utilities producing nuclear energy are responsible for the management of the radioactive waste, including final disposal. As regards low and intermediate level waste, the approach has been adopted to employ the power plant sites for locations of repositories. The repositories will be excavated at the depth of about 50 to 125 m in the bedrock of the two Finnish nuclear power plant sites, Loviisa and Olkiluoto. The performance analysis presented in this paper has been carried out for the Preliminary Safety Analysis Report (PSAR) of the Olkiluoto repository. A flexible model has been developed to estimate the release of radionuclides from waste packages and their subsequent transport through the engineered barriers in the repository. Gradual degradation of the engineered barriers is accounted for by altering parameters at fixed time points. Safety margins of the disposal concept have been evaluated by including disturbed evolution scenarios in the analysis. 13 references, 10 figures, 2 tables

  9. Project Guarantee 1985. Final repository for high-level radioactive wastes: The system of safety barriers

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    Final disposal of radioactive waste involves preventing the waste from returning from the repository location into the biosphere by means of successively arranged containment measures known as safety barriers. In the present volume NGB 85-04 of the series of reports for Project 'Guarantee' 1985, the safety barrier system for the type C repository for high-level waste is described. The barrier parameters which are relevant for safety analysis are quantified and associated error limits and data scatter are given. The aim of the report is to give a summary documentation of the safety analysis input data and their scientific background. For secure containment of radioactive waste safety barriers are used which effectively limit the release of radioactive material from the repository (release barriers) and effectively retard the entry of the original radioactive material into the biosphere (time barriers). Safety barriers take the form of both technically constructed containment measures and the siting of the repository in suitable geological formations. The technical safety barrier system in the case of high-level waste comprises: the waste solidification matrix (borosilicate glass), massive steel canisters, encasement of the waste canisters, encasement of the waste canisters in highly compacted bentonite, sealing of vacant storage space and access routes on repository closure. The natural geological safety barriers - the host rock and overlying formations provide sufficiently long deep groundwater flow times from the repository location to the earth's surface and for additional lengthening of radionuclide migration times by means of various chemical and physical retardation mechanisms. The stability of the geological formations is so great that hydrogeological system is protected for a sufficient length of time from deterioration caused, in particular, by erosion. Observations in the final section of the report indicate that input data for the type C repository safety

  10. Performance of high level waste forms and engineered barriers under repository conditions

    International Nuclear Information System (INIS)

    1991-02-01

    The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

  11. Research procedure and criteria for analysis and choice of variants for construction of national radioactive waste repository

    International Nuclear Information System (INIS)

    Vachev, B.

    1993-01-01

    General principles, overlying objectives and basic radioactive waste management strategy future priorities are considered. The research procedure is based on system approach and analysis, decision making theory, basic objectives and principles of the national repository construction. Main criteria and some basic notions (like radioactive wastes environment and radioactive wastes barriers - input and output) are introduced. Six environment elements are identified: surroundings and natural environment, economic, scientific and technical-technological, socio-psychological, legal and institutional-political. Flow charts of the hierarchical structure of research procedure, decision making levels and direct and back feeds are presented and a scenario analysis is proposed as one of the tools for reflection of uncertainty. The hierarchical structure of the high level waste repository construction scenarios and variants tree (8 levels) is defined. The methodology and methods of analysis, screening and choice of variants is considered. A 7-group system of criteria and constrains for analysis, screening and choice of variants is formulated. One implementation of the proposed methodology and procedure is the technological choice for radioactive waste conditioning and solving of a preliminary site selection problem. 4 figs., 25 refs. (author)

  12. Solute transport in fractured rock - applications to radionuclide waste repositories

    International Nuclear Information System (INIS)

    Neretnieks, I.

    1990-12-01

    Flow and solute transport in fractured rocks has been intensively studied in the last decade. The increased interest is mainly due to the plans in many countries to site repositories for high level nuclear waste in deep geologic formations. All investigated crystalline rocks have been found to be fractured and most of the water flows in the fractures and fracture zones. The water transports dissolved species and radionuclides. It is thus of interest to be able to understand and to do predictive modelling of the flowrate of water, the flowpaths and the residence times of the water and of the nuclides. The dissolved species including the nuclides will interact with the surrounding rock in different ways and will in many cases be strongly retarded relative to the water velocity. Ionic species may be ion exchanged or sorbed in the mineral surfaces. Charges and neutral species may diffuse into the stagnant waters in the rock matrix and thus be withdrawn from the mobile water. These effects will be strongly dependent on how much rock surface is in contact with the flowing water. It has been found in a set of field experiments and by other observations that not all fractures conduct water. Furthermore it is found that conductive fractures only conduct the water in a small part of the fracture in what is called channels or preferential flowpaths. This report summarizes the present concepts of water flow and solute transport in fractured rocks. The data needs for predictive modelling are discussed and both field and laboratory measurement which have been used to obtain data are described. Several large scale field experiments which have been specially designed to study flow and tracer transport in crystalline rocks are described. In many of the field experients new techniques have been developed and used. (81 refs.) (author)

  13. Nuclear waste repository in basalt: preliminary socioeconomic assessment

    International Nuclear Information System (INIS)

    Cluett, C.; Bolton, P.A.; Malhotra, S.; McStay, J.R.; Slingsby, J.A.

    1984-06-01

    This report was prepared as a part of the continuing site characterization activities for a proposed nuclear waste repository in basalt (NWRB) to be located on the Hanford Site near Richland, Washington. The purpose of this study is to assess the social and economic impacts that could be caused by the construction and operation of the proposed NWRB facility. The specific objectives of this study are to describe historical socioeconomic trends in the study area, to describe current conditions, to project future baseline conditions without the NWRB, to project potential impacts due to the proposed NWRB under two alternative regional development scenarios and assess their significance, and to suggest an overall impact management and mitigation strategy. A closely related objective is to assemble a comprehensive socioeconomic data base that can be easily updated for future analyses. This study examines employment, labor supply, population change, housing, local transportation, revenues, and expenditures for public services. This report documents the marked demographic and economic decline that has occurred in the study area since 1981 and concludes that future baseline growth will resume at a relatively slower pace after further expected declines have been experienced through about 1985. The projected socioeconomic impacts of the NWRB development are assessed under two alternative baseline scenarios and are not expected to be significant in either case. With careful planning and attention to impact mitigation, including public participation and interaction with local and regional planning agencies, potential socioeconomic impacts can be anticipated and managed effectively. Recommendations are made for providing frequent updating of the data base and for improving the analysis of socioeconomic impacts. 68 references, 19 figures, 38 tables

  14. Developing multinational radioactive waste repositories: Infrastructural framework and scenarios of cooperation

    International Nuclear Information System (INIS)

    2004-10-01

    Currently the management of radioactive wastes centres on national strategies for collection, treatment, interim storage and disposal. This tendency to focus exclusively on national strategies reflects the fact that radioactive waste is a sensitive political issue, making cooperation among countries difficult. It is consistent with the accepted principle that a country that enjoys the benefit of nuclear energy, or the utilization of nuclear technology, should also take full responsibility for managing the generated radioactive waste. However, there are countries whose radioactive waste volumes do not easily justify a national repository, and/or countries that do not have the resources or favourable natural conditions for waste disposal to dedicate to a national repository project or would prefer to collaborate in shared initiatives because of their economic advantages. In such cases it may be appropriate for these countries to engage in a multinational collaborative effort to ensure that they have access to a common repository, in order that they can fulfil their responsibilities for their managing wastes safely. In response to requests from several Member States expressing an interest in multinational disposal options, the IAEA produced in 1998 a TECDOC outlining the important factors to be taken into account in the process of realizing such options. These factors include for example, technical (safety), institutional (legal, safeguards), economic (financial) socio-political (public acceptance) and ethical considerations. The present report reviews the work done in the previous study, taking into account developments since its publication as well as current activities in the field of multinational repositories. The report attempts to define the concepts involved in the creation of multinational repositories, to explore the likely scenarios, to examine the conditions for successful implementation, and to point out the benefits and challenges inherent to

  15. Project Guarantee 1985. Radioactive wastes: Properties and allocation to final repository types

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    An overview of waste-specific data, as input into constructional engineering studies and safety analyses of Project Guarantee, is presented which describes the activity inventory of the radioactive waste to be disposed of, classified according to origin, the quantitative spezifications of the waste, the concept of classifying waste into appropriate categories, grouping into major categories and distribution of these between the different repository types, and finally, control measures which ensure observance of the specifications of the waste to be disposed of. It is expedient, for conceptional considerations and for the operational phase of the repository, to split the waste up into several suitably specified waste categories according to the practical aspects of origin and conditioning. This can be done in such a way that the waste within a specific category is sufficiently homogeneous with regard to its radiological properties and chemical composition for the requirements of safety analysis. The present volume contains base-data for around 30 waste types. Two waste types are documented with more detailed data as an example of the practicability of the comprehensive waste characterisation contained in reference report NTB 84-47. It is shown that waste-specific data which go into safety analysis and constructional engineering project studies are available in an appropriate degree of detail. The method of distributing the waste between repositories with differing degrees of protection and procedures for controlling adherence to admission specifications are developed and documented. It can be ensured that no waste with an impermissibly high radiotoxicity level will later be emplaced in a repository for low- and intermediate-level waste

  16. Aspects on the gas generation and migration in repositories for high level waste in salt formations

    International Nuclear Information System (INIS)

    Ruebel, Andre; Buhmann, Dieter; Meleshyn, Artur; Moenig, Joerg; Spiessl, Sabine

    2013-07-01

    In a deep geological repository for high-level waste, gases may be produced during the post-closure phase by several processes. The generated gases can potentially affect safety relevant features and processes of the repository, like the barrier integrity, the transport of liquids and gases in the repository and the release of gaseous radionuclides from the repository into the biosphere. German long-term safety assessments for repositories for high-level waste in salt which were performed prior 2010 did not explicitly consider gas transport and the consequences from release of volatile radionuclides. Selected aspects of the generation and migration of gases in repositories for high-level waste in a salt formation are studied in this report from the viewpoint of the performance assessment. The knowledge on the availability of water in the repository, in particular the migration of salt rock internal fluids in the temperature field of the radioactive waste repository towards the emplacement drifts, was compiled and the amount of water was roughly estimated. Two other processes studied in this report are on the one hand the release of gaseous radionuclides from the repository and their potential impact in the biosphere and on the other hand the transport of gases along the drifts and shafts of the repository and their interaction with the fluid flow. The results presented show that there is some gas production expected to occur in the repository due to corrosion of container material from water disposed of with the backfill and inflowing from the host rock during the thermal phase. If not dedicated gas storage areas are foreseen in the repository concept, these gases might exceed the storage capacity for gases in the repository. Consequently, an outflow of gases from the repository could occur. If there are failed containers for spent fuel, radioactive gases might be released from the containers into the gas space of the backfill and subsequently transported together

  17. An assessment of the radiological impact of coastal erosion of the UK Low-Level Waste Repository - 59137

    International Nuclear Information System (INIS)

    Sumerling, Trevor; Shevelan, John; Cummings, Richard; Fish, Paul; Towler, George; Penfold, James

    2012-01-01

    The UK Low Level Waste Repository Ltd submitted an Environmental Safety Case for the disposal of low-level waste to our regulator, the Environment Agency, on the 1 May 2011. This includes assessments of the long-term radiological safety of past and future disposals. A particular feature of the Low Level Waste Repository (LLWR) is that, because of its proximity to the coast, the site is vulnerable to coastal erosion. Our present understanding is that the site will be eroded on a timescale of a few hundred to a few thousand years, with consequent disruption of the repository, and dispersal of the wastes. We have undertaken a programme of scientific research and monitoring to characterise the evolution and function of the current coastal system that provides a basis for forecasting its future evolution. This has included modelling of contemporary hydrodynamics, geo-morphological mapping, repeat LiDAR and aerial photographic surveys to detect patterns and rates of change, coastal inspections and reconstructions of post-glacial (i.e. last 15, 000 years) sea levels and sediment budgets. Estimates of future sea-level rise have been derived from international sources and consideration given to the impact of such on the local coastline. Two alternative models of coastal recession have then been applied, one empirical and one physical-process based, taking account of the composition of Quaternary-age sediments between the coast and the site and uncertainties in future local sea level change. Comparison of the ranges of calculated times to site contact with sea-level rise indicate that the repository is most likely to be disrupted by undercutting of the engineered vaults and of the trenches. A novel and flexible radiological assessment model has been developed to analyse the impacts of the erosion of the repository and subsequent dispersal of wastes. The model represents the spatial layout of the site and distribution of radionuclides within the repository and is able to take

  18. Effect of ionizing radiation on the waste package environment

    Energy Technology Data Exchange (ETDEWEB)

    Reed, D.T. [Argonne National Lab., IL (USA); Van Konynenburg, R.A. [Lawrence Livermore National Lab., CA (USA)

    1991-05-01

    The radiolytic production of nitrogen oxides, nitrogen acids and ammonia are discussed in relation to the expected environment in a high-level waste repository that may be constructed at the Yucca Mountain site if it is found to be suitable. Both literature data and repository-relevant data are summarized for air-water vapor systems. The limiting cases of a dry air and a pure water vapor gas phase are also discussed. Design guidelines and recommendations, based solely on the potential consequence of radiation enhancement of corrosion, are given. 13 refs., 5 figs., 1 tab.

  19. Effect of ionizing radiation on the waste package environment

    International Nuclear Information System (INIS)

    Reed, D.T.; Van Konynenburg, R.A.

    1991-01-01

    The radiolytic production of nitrogen oxides, nitrogen acids and ammonia are discussed in relation to the expected environment in a high-level waste repository that may be constructed at the Yucca Mountain site if it is found to be suitable. Both literature data and repository-relevant data are summarized for air-water vapor systems. The limiting cases of a dry air and a pure water vapor gas phase are also discussed. Design guidelines and recommendations, based solely on the potential consequence of radiation enhancement of corrosion, are given. 13 refs., 5 figs., 1 tab

  20. Repository simulation tests

    International Nuclear Information System (INIS)

    Wicks, G.G.; Bibler, N.E.; Jantzen, C.M.; Plodinec, M.J.

    1984-01-01

    The repository simulation experiments described in this paper are designed to assess the performance of SRP waste glass under the most realistic repository conditions that can be obtained in the laboratory. These tests simulate the repository environment as closely as possible and introduce systematically the variability of the geology, groundwater chemistry, and waste package components during the leaching of the waste glass. The tests evaluate waste form performance under site-specific conditions, which differ for each of the geologic repositories under consideration. Data from these experiments will aid in the development of a realistic source term that can describe the release of radionuclides from SRP waste glass as a component of proposed waste packages. Hence, this information can be useful to optimize waste package design for SRP waste glass and to provide data for predicting long-term performance and subsequent conformance to regulations. The repository simulation tests also help to bridge the gap in interpreting results derived from tests performed under the control of the laboratory to the uncertainity and variability of field tests. In these experiments, site-specific repository components and conditions are emphasized and only the site specific materials contact the waste forms. An important feature of these tests is that both actual and simulated waste glasses are tested identically. 7 figures, 2 tables

  1. Design perspectives for the low and intermediate level radioactive waste repository in Korea

    International Nuclear Information System (INIS)

    Kim, Young Ki; Koh, Kwang Hoon; Lee, Sang Sun; Lee, Byung Sik; Choi, Gi Won

    2007-01-01

    The underground waste repository is located at Gyeongju and is designed for the disposal of all the Low- and Intermediate Level Radioactive Waste(LILW). It is scheduled to commence operations in the beginning of 2009. The repository, with a disposal capacity of 800,000 drums, will be constructed in granite rock near the seashore at the Gyeongju site. The repository will be designed to be constructed in phases to reach its final capacity 800,000 drums. In the first phase of construction, the repository will have a capacity to store 100,000 drums. The repository will house all LILW generated in the Republic of Korea. The first phase of the repository design consists of an assess shaft, a construction tunnel, an operating tunnel, an unloading tunnel, and six(6) silos. The silos are located at 80 to 130 meters below Mean Sea level (MSL), in bedrock. Each silo is 24.8m in diameter and 52.4m in height. The silo will be reinforced with concrete lining for rock supports which will also act aas an engineered barrier in limiting radioactive nuclide release aft closure. After serving its intended function the repository will be filled and sealed. The primary objective of filling and sealing is to prevent ground water flow into the silo through the tunnel system and to prevent inadvertent intrusion into the repository after closure

  2. A geologic scenario for catastrophic failure of the Yucca Mountain Nuclear Waste Repository, Nevada

    International Nuclear Information System (INIS)

    McMackin, M.R.

    1993-01-01

    A plausible combination of geologic factors leading to failure can be hypothesized for the Yucca Mountain Nuclear Waste Repository. The scenarios is constructed using elementary fault mechanics combined with geologic observations of exhumed faults and published information describing the repository site. The proposed repository site is located in the Basin and Range Province, a region of active crustal deformation demonstrated by widespread seismicity. The Yucca Mountain area has been characterized as tectonically quiet, which in the context of active crustal deformation may indicate the accumulation of the stresses approaching the levels required for fault slip, essentially stick-slip faulting. Simultaneously, dissolution of carbonate rocks in underlying karst aquifers is lowering the bulk strength of the rock that supports the repository site. Rising levels of hydrostatic stress concurrent with a climatically-driven rise in the water table could trigger faulting by decreasing the effective normal stress that currently retards fault slip. Water expelled from collapsing caverns in the underlying carbonate aquifer could migrate upward with sufficient pressure to open existing fractures or create new fractures by hydrofracturing. Water migrating through fractures could reach the repository in sufficient volume to react with heated rock and waste perhaps creating steam explosions that would further enhance fracture permeability. Closure of conduits in the underlying carbonate aquifer could lead to the elevation of the saturated zone above the level of the repository resulting in sustained saturation of radioactive waste in the repository and contamination of through-flowing groundwater

  3. NF-PRO research on a repository for vitrified waste and spent fuel

    International Nuclear Information System (INIS)

    Sneyers, A.

    2006-01-01

    NF-PRO is a four-year (2004-2007) Integrated Project supported by funding under the Sixth Research (EURATOM) Programme of the European Commission. NF-PRO is coordinated by SCK C EN and investigates key processes in the near-field of geological repositories for the disposal of high-level vitrified waste and spent nuclear fuel. The near-field of a geological repository consists of the area surrounding the waste packages and is composed of several engineered barriers that enclose and confine the disposed waste. These barriers include the waste form, the waste canisters, backfills, seals, plugs and the part of the host rock that has been modified by the excavation of the repository. In all repository designs under investigation within EU Member States, the near-field plays an important role in ensuring the overall safety of disposal: its principal function is to retain radionuclides over extended periods of time and to minimise their release from the waste to the host rock. The main objective of NF-PRO is to integrate European research on the near field with the aim of enhancing common understanding of the long-term changes taking place in a deep repository. NF-PRO assesses how these changes affect the containment of the disposed radioactive waste. Knowledge generated by the project can be applied in waste management programmes to optimise repository designs and to make barriers functional and resource-efficient. The integration of results from detailed process studies in assessments on the overall near-field system performance is a key objective of NF-PRO. The level of integration envisaged by NF-PRO has not yet been achieved in earlier research projects supported by the European Commission. Accordingly, NF PRO represents a major step forward in the establishing of the scientific and technical basis for geological disposal and the safe management of radioactive wastes

  4. Project Guarantee 1985. Repository for high-level radioactive waste: construction and operation

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    An engineering project study aimed at demonstrating the feasibility of constructing a deep repository for high-level waste (Type C repository) has been carried out; the study is based on a model data-set representing typical geological and rock mechanical conditions as found outside the so-called Permocarboniferous basin in the regions under investigation by Nagra in Cantons Aargau, Schaffhausen, Solothurn and Zuerich. The repository is intended for disposal of high-level waste and any intermediate-level waste from re-processing in which the concentration of long-lived alpha-emitters exceeds the permissible limits set for a Type B repository. Final disposal of high-level waste is in subterranean, horizontally mined tunnels and of intermediate-level waste in underground vertical silos. The repository is intended to accomodate a total of around 6'000 HWL-cylinders (gross volume of around 1'200 m3) and around 10'000 m3 of intermediate-level waste. The total excavated volume is around 1'100'000 m3 and a construction time for the whole repository (up to the beginning of emplacement) of around 15 years is expected. For the estimated 50-year emplacement operations, a working team of around 60 people will be needed and a team of around 160 for the simultaneous tunnelling operations and auxiliary work. The project described in the present report permits the conclusion that construction of a repository for high-level radioactive waste and, if necessary, spent fuel-rods is feasible with present-day technology

  5. Preliminary total-system analysis of a potential high-level nuclear waste repository at Yucca Mountain

    International Nuclear Information System (INIS)

    Eslinger, P.W.; Doremus, L.A.; Engel, D.W.; Miley, T.B.; Murphy, M.T.; Nichols, W.E.; White, M.D.; Langford, D.W.; Ouderkirk, S.J.

    1993-01-01

    The placement of high-level radioactive wastes in minded repositories deep underground is considered a disposal method that would effectively isolate these wastes from the environment for long periods of time. This report describes modeling performed at PNL for Yucca Mountain between May and November 1991 addressing the performance of the entire repository system related to regulatory criteria established by the EPA in 40 CFR Part 191. The geologic stratigraphy and material properties used in this study were chosen in cooperation with performance assessment modelers at Sandia National Laboratories (SNL). Sandia modeled a similar problem using different computer codes and a different modeling philosophy. Pacific Northwest Laboratory performed a few model runs with very complex models, and SNL performed many runs with much simpler (abstracted) models

  6. Preliminary total-system analysis of a potential high-level nuclear waste repository at Yucca Mountain

    Energy Technology Data Exchange (ETDEWEB)

    Eslinger, P.W.; Doremus, L.A.; Engel, D.W.; Miley, T.B.; Murphy, M.T.; Nichols, W.E.; White, M.D. [Pacific Northwest Lab., Richland, WA (United States); Langford, D.W.; Ouderkirk, S.J. [Westinghouse Hanford Co., Richland, WA (United States)

    1993-01-01

    The placement of high-level radioactive wastes in mined repositories deep underground is considered a disposal method that would effectively isolate these wastes from the environment for long periods of time. This report describes modeling performed at PNL for Yucca Mountain between May and November 1991 addressing the performance of the entire repository system related to regulatory criteria established by the EPA in 40 CFR Part 191. The geologic stratigraphy and material properties used in this study were chosen in cooperation with performance assessment modelers at Sandia National Laboratories (SNL). Sandia modeled a similar problem using different computer codes and a different modeling philosophy. Pacific Northwest Laboratory performed a few model runs with very complex models, and SNL performed many runs with much simpler (abstracted) models.

  7. Coupled thermo–hydro–mechanical processes for the Dutch radioactive waste repository

    NARCIS (Netherlands)

    Buragohain, P.; Vardon, P.J.; Hicks, M.A.; Vardon, P.J.; Bykov, D.

    2016-01-01

    Disposal of spent nuclear fuel and long lived radioactive waste in deep clay geological formations is one of the promising options worldwide. In this concept of the geological disposal system, the Boom Clay is considered as a potential host rock when designing a generic waste repository in the

  8. Morsleben repository for radioactive waste (ERAM). Operational safety, radiation protection and environmental monitoring. Release: December 2009

    International Nuclear Information System (INIS)

    2010-01-01

    The report overviews the monitoring activities of the Federal Office for Radiation Protection at the Morsleben repository for radioactive waste (ERAM), focussing the ERAM inventory of radioactive waste and the measures and results of geomechanical and hydrogeological monitoring, operational radiation protection, the monitoring of discharges of radioactive substances, environmental monitoring, and the dose levels expected from discharges of radioactive substances. (orig.)

  9. The influence of organic materials on the near field of an intermediate level radioactive waste repository

    International Nuclear Information System (INIS)

    Wilkins, J.D.

    1988-01-01

    The influence of organic materials which are present in some intermediate level wastes on the chemistry of the near field of a radioactive waste repository is discussed. Particular attention is given to the possible formation of water soluble complexing agents as a result of the radiation field and chemical conditions. The present state of the research is reviewed. (author)

  10. Survey of near-field flow calculations for nuclear waste repositories NMA L21

    International Nuclear Information System (INIS)

    Wilson, R.N.; Holland, D.H.

    1979-11-01

    A survey of methods and codes which describe the flow of groundwater and the migration of radioactive waste in and about nuclear repositories was performed. A number of laboratories engaged in studies of waste migration and groundwater flow were visited in order to discuss the general problem and obtain reports of work being performed. The results of this survey are discussed

  11. The influence of organic materials on the near field of an intermediate level waste radioactive waste repository

    International Nuclear Information System (INIS)

    Wilkins, J.D.

    1988-02-01

    The influence of organic materials, which are present in some intermediate level wastes, on the chemistry of the near field of a radioactive waste repository is discussed. Particular attention is given to the possible formation of water soluble complexing agents formed as a result of the radiation field and chemical conditions. The present state of the research is reviewed. (author)

  12. Radioactive waste disposal programme and siting regions for geological deep repositories. Executive summary. November 2008

    International Nuclear Information System (INIS)

    2008-11-01

    There are radioactive wastes in Switzerland. Since many decades they are produced by the operation of the five nuclear power plants, by medicine, industry and research. Important steps towards the disposal of these wastes are already realized; the corresponding activities are practised. This particularly concerns handling and packaging of the radioactive wastes, their characterization and inventory, as well as the interim storage and the inferred transportations. Preparatory works in the field of scientific research on deep geological repositories have allowed to acquire high level of technical and scientific expertise in that domain. The feasibility of building long-term safe geological repositories in Switzerland was demonstrated for all types of radioactive wastes; the demonstration was accepted by the Federal Council. There is enough knowledge to propose geological siting regions for further works. The financial funds already accumulated guaranty the financing of the dismantling of the power plants as well as building deep geological repositories for the radioactive wastes. The regulations already exist and the organisational arrangements necessary for the fruitful continuation of the works already done have been taken. The programme of the disposal of radioactive wastes also describes the next stages towards the timely realization of the deep repositories as well as the level of the financial needs. The programme is updated every five years, checked by the regulatory bodies and accepted by the Federal Council who reports to the parliament. The process of choosing a site, which will be completed in the next years, is detailed in the conceptual part of the programme for deep geological repositories. The NAGRA proposals are based exclusively on technical and scientific considerations; the global evaluation taking into account also political considerations has to be performed by the authorities and the Federal Council. The programme states that at the beginning of

  13. Draft Technical Position Subtask 1.1: waste package performance after repository closure. Volume 1

    International Nuclear Information System (INIS)

    Davis, M.S.; Schweitzer, D.G.

    1983-08-01

    This document provides guidance to the DOE on the issues and information necessary for the NRC to evaluate waste package performance after repository closure. Minimal performance objectives of the waste package are required by proposed 10 CFR 60. This Draft Technical Position describes the various options available to the DOE for compliance and discusses advantages and disadvantages of various choices. Examples are discussed dealing with demonstrability, predictability and reasonable assurance. The types of performance are considered. The document summarizes presently identified high priority issues needed to evaluate waste package performance after repository closure. 20 references, 7 tables

  14. Workshop on Potentially Disruptive Phenomena for Nuclear Waste Repositories, July 27-28, 1977

    International Nuclear Information System (INIS)

    Jacobson, J.J.

    1977-01-01

    The workshop on Potentially Disruptive Phenomena for Nuclear Waste Repositories brought together experts in the geosciences to identify and evaluate potentially disruptive events and processes and to contribute ideas on how to extrapolate data from the past into the next one million years. The analysis is to be used to model a repository in geologic media for long-term safety assessments of nuclear waste storage. The workshop included invited presentations on the following items: an overview of the Waste Isolation Safety Assessment Program (WISAP), simulation techniques, subjective probabilities and methodology of obtaining data, similar modeling efforts at Lawrence Livermore and Sandia Laboratories, and geologic processes or events

  15. Alternative configurations for the waste-handling building at the Yucca Mountain Repository

    International Nuclear Information System (INIS)

    1990-08-01

    Two alternative configurations of the waste-handling building have been developed for the proposed nuclear waste repository in tuff at Yucca Mountain, Nevada. One configuration is based on criteria and assumptions used in Case 2 (no monitored retrievable storage facility, no consolidation), and the other configuration is based on criteria and assumptions used in Case 5 (consolidation at the monitored retrievable storage facility) of the Monitored Retrievable Storage System Study for the Repository. Desirable waste-handling design concepts have been selected and are included in these configurations. For each configuration, general arrangement drawings, plot plans, block flow diagrams, and timeline diagrams are prepared

  16. An initial study of the behaviour under repository conditions of inactive components of nuclear wastes

    International Nuclear Information System (INIS)

    Biddle, P.; Rees, J.H.

    1988-02-01

    This review extends the appreciation of repository behaviour to include the inactive components of wastes and their degradation products. These materials include a wide range of metals and organics, sludges and decommissioning wastes. The effect of degradation products on the solubility of long-lived radionuclides and any active daughters and their sorption on surfaces of the repository are assessed. Research requirements are identified that may help to improve significantly the assessment of the effects of inactive materials. Data required to improve the quality of inventory data on nuclear wastes are listed. (author)

  17. NAGRA - Long-term safety - The main task of deep repositories for radioactive wastes

    International Nuclear Information System (INIS)

    2015-10-01

    This comprehensive brochure published by the Swiss National Cooperative for the Disposal of Radioactive Waste (NAGRA) examines the necessity for the safe disposal of radioactive wastes in Switzerland and discusses the requirements placed on such long-term waste depositories The effects of ionizing radiation on people and the protection provided by the deep repositories are examined. The construction of such deep repositories is looked at, as are the developments expected in the depositories over thousands of years. A comparison with natural occurrences is made and lessons to be learned from nature are discussed. Ideas for the marking of the depository sites are presented. A glossary of relevant terms completes the report

  18. Technical and logistic provisions for the delivery of radioactive wastes in the final repository Konrad

    International Nuclear Information System (INIS)

    Poeppinghaus, Jens

    2013-01-01

    The beginning of radioactive waste delivery to the final repository Konrad is planned for 2019. The main issue for the technical and logistic provisions is the development of a concept for the transport of the licensed radioactive waste containers to the site, including a turning concept for cylindrical waste forms and planning, construction and manufacture of transport equipment. Further issues include a logistic concept considering specific boundary conditions as administrative processes, priorities, special features of the delivering institutions and technical requirements of the repository.

  19. Status of technologies related to the isolation of radioactive wastes in geologic repositories

    Energy Technology Data Exchange (ETDEWEB)

    Irish, E R [International Atomic Energy Agency, Vienna (Austria). Div. of Nuclear Safety and Environmental Protection; Cooley, C R [Department of Energy, Washington, DC (USA). Office of Nuclear Waste Management

    1980-09-01

    The authors present an overview of the status of technologies relevant to the isolation of radioactive wastes in geologic repositories. In addition to summarizing scientific and technical work on waste forms and packages, the: a) importance of the systems viewpoint, b) importance of modeling, c) need for site-specific investigations, d) consideration of future sub-surface human activities and e) prospects for successful isolation are discussed. It is concluded that successful isolation of radioactive wastes from the biosphere appears technically feasible for periods of thousands of years provided that the systems view is used in repository siting and design.

  20. Rock mass modification around a nuclear waste repository in welded tuff

    International Nuclear Information System (INIS)

    Mack, M.G.; Brandshaug, T.; Brady, B.H.

    1989-08-01

    This report presents the results of numerical analyses to estimate the extent of rock mass modification resulting from the presence of a High Level Waste (HLW) repository. Changes in rock mass considered are stresses and joint deformations resulting from disposal room excavation and thermal efffects induced by the heat generated by nuclear waste. rock properties and site conditions are taken from the Site Characterization Plan Conceptual Design Report for the potential repository site at Yucca Mountain, Nevada. Analyses were conducted using boundary element and distinct element methods. Room-scale models and repository-scale models were investigated for up to 500 years after waste emplacement. Results of room-scale analyses based on the thermoelastic boundary element model indicate that a zone of modified rock develops around the disposal rooms for both vertical and horizontal waste emplacement. This zone is estimated to extend a distance of roughly two room diameters from the room surface. Results from the repository-scale model, which are based on the thermoelastic boundary element model and the distinct element model, indicate a zone with modified rock mass properties starting approximately 100 m above and below the repository, with a thickness of approximately 200 m above and 150 m below the repository. Slip-prone subhorizontal features are shown to have a substantial effect on rock mass response. The estimates of rock mass modification reflect uncertainties and simplifying assumptions in the models. 32 refs., 57 figs., 1 tab

  1. Numerical modeling of the geomechanical response of a rock mass to a radioactive waste repository

    International Nuclear Information System (INIS)

    Hardy, M.P.; St John, C.M.; Hocking, G.

    1979-06-01

    Geotechnical numerical models capable of predicting the thermomechanical response and groundwater movements around an underground radioactive waste repository are vital to the success of the nuclear waste disposal program. In the absence of directly related engineering experience, the design, risk assessment, and licensing procedures of a repository will be reliant on predictions made using such models. This paper reviews models being used to assist in repository design and summarizes the results of a recent parametric study of underground disposal in basaltic rocks. On the basis of preliminary site data, it is concluded that the allowable areal density of heat-generating waste will be controlled by the stability of placement rooms and the boreholes in which waste canisters are placed. Regional effects including thermally induced upward groundwater flow, appear to present less severe problems

  2. Natural geochemical analogues of the near field of high-level nuclear waste repositories

    International Nuclear Information System (INIS)

    Apps, J.A.

    1995-01-01

    United States practice has been to design high-level nuclear waste (HLW) geological repositories with waste densities sufficiently high that repository temperatures surrounding the waste will exceed 100 degrees C and could reach 250 degrees C. Basalt and devitrified vitroclastic tuff are among the host rocks considered for waste emplacement. Near-field repository thermal behavior and chemical alteration in such rocks is expected to be similar to that observed in many geothermal systems. Therefore, the predictive modeling required for performance assessment studies of the near field could be validated and calibrated using geothermal systems as natural analogues. Examples are given which demonstrate the need for refinement of the thermodynamic databases used in geochemical modeling of near-field natural analogues and the extent to which present models can predict conditions in geothermal fields

  3. Interim performance specifications for conceptual waste-package designs for geologic isolation in salt repositories

    International Nuclear Information System (INIS)

    1983-06-01

    The interim performance specifications and data requirements presented apply to conceptual waste package designs for all waste forms which will be isolated in salt geologic repositories. The waste package performance specifications and data requirements respond to the waste package performance criteria. Subject areas treated include: containment and controlled release, operational period safety, criticality control, identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available

  4. Hydrothermal modeling for the efficient design of thermal loading in a nuclear waste repository

    International Nuclear Information System (INIS)

    Cho, Won-Jin; Kim, Jin-Seop; Choi, Heui-Joo

    2014-01-01

    Highlights: • Three-dimensional hydrothermal modeling for HLW repository is performed. • The model reduces the peak temperature in the repository by about 10 °C. • Decreasing the tunnel distance is more efficient to improve the disposal density. • The EDZ surrounding the deposition hole increases the peak temperature. • The peak temperature for the double-layer repository remains below the limit. - Abstract: The thermal analysis of a geological repository for nuclear waste using the three-dimensional hydrothermal model is performed. The hydrothermal model reduces the maximum peak temperature in the repository by about 10 °C compared to the heat conduction model with constant thermal conductivities. Decreasing the tunnel distance is more efficient than decreasing the deposition hole spacing to improve the disposal density for a given thermal load. The annular excavation damaged zone surrounding the deposition hole has a considerable effect on the peak temperature. The possibility of double-layer repository is analyzed from the viewpoint of the thermal constraints of the repository. The maximum peak temperature for the double-layer repository is slightly higher than that for the single-layer repository, but remains below the temperature limit

  5. Continuous Improvement and the Safety Case for the Waste Isolation Pilot Plant Geologic Repository - 13467

    Energy Technology Data Exchange (ETDEWEB)

    Van Luik, Abraham; Patterson, Russell; Nelson, Roger [US Department of Energy, Carlsbad Field Office, 4021 S. National parks Highway, Carlsbad, NM 88220 (United States); Leigh, Christi [Sandia National Laboratories Carlsbad Operations, 4100 S. National parks Highway, Carlsbad, NM 88220 (United States)

    2013-07-01

    The Waste Isolation Pilot Plant (WIPP) is a geologic repository 2150 feet (650 m) below the surface of the Chihuahuan desert near Carlsbad, New Mexico. WIPP permanently disposes of transuranic waste from national defense programs. Every five years, the U.S. Department of Energy (DOE) submits an application to the U.S. Environmental Protection Agency (EPA) to request regulatory-compliance re-certification of the facility for another five years. Every ten years, DOE submits an application to the New Mexico Environment Department (NMED) for the renewal of its hazardous waste disposal permit. The content of the applications made by DOE to the EPA for re-certification, and to the NMED for permit-renewal, reflect any optimization changes made to the facility, with regulatory concurrence if warranted by the nature of the change. DOE points to such changes as evidence for its having taken seriously its 'continuous improvement' operations and management philosophy. Another opportunity for continuous improvement is to look at any delta that may exist between the re-certification and re-permitting cases for system safety and the consensus advice on the nature and content of a safety case as being developed and published by the Nuclear Energy Agency's Integration Group for the Safety Case (IGSC) expert group. DOE at WIPP, with the aid of its Science Advisor and teammate, Sandia National Laboratories, is in the process of discerning what can be done, in a reasonably paced and cost-conscious manner, to continually improve the case for repository safety that is being made to the two primary regulators on a recurring basis. This paper will discuss some aspects of that delta and potential paths forward to addressing them. (authors)

  6. Spent fuel and high level waste: Chemical durability and performance under simulated repository conditions. Results of a coordinated research project 1998-2004

    International Nuclear Information System (INIS)

    2007-10-01

    This publication contains the results of an IAEA Coordinated Research Project (CRP). It provides a basis for understanding the potential interactions of waste form and repository environment, which is necessary for the development of the design and safety case for deep disposal. Types of high level waste matrices investigated include spent fuel, glasses and ceramics. Of particular interest are the experimental results pertaining to ceramic forms such as SYNROC. This publication also outlines important areas for future work, namely, standardized, collaborative experimental protocols for package-release studies, structured development and calibration of predictive models linking the performance of packaged waste and the repository environment, and studies of the long term behaviour of the wastes, including active waste samples

  7. Long term safety requirements and safety indicators for the assessment of underground radioactive waste repositories

    International Nuclear Information System (INIS)

    Vovk, Ivan

    1998-01-01

    This presentation defines: waste disposal, safety issues, risk estimation; describes the integrated waste disposal process including quality assurance program. Related to actinides inventory it shows the main results of calculated activity obtained by deterministic estimation. It includes the Radioactive Waste Safety Standards and requirements; features related to site, design and waste package characteristics, as technical long term safety criteria for radioactive waste disposal facilities. Fundamental concern regarding the safety of radioactive waste disposal systems is their radiological impact on human beings and the environment. Safety requirements and criteria for judging the level of safety of such systems have been developed and there is a consensus among the international community on their basis within the well-established system of radiological protection. So far, however, little experience has been gained in applying long term safety criteria to actual disposal systems; consequently, there is an international debate on the most appropriate nature and form of the criteria to be used, taking into account the uncertainties involved. Emerging from the debate is the increasing conviction that the combined use of a variety of indicators would be advantageous in addressing the issue of reasonable assurance in the different time frames involved and in supporting the safety case for any particular repository concept. Indicators including risk, dose, radionuclide concentration, transit time, toxicity indices, fluxes at different points within the system, and barrier performance have all been identified as potentially relevant. Dose and risk are the indicators generally seen as most fundamental, as they seek directly to describe the radiological impact of a disposal system, and these are the ones that have been incorporated into most national standards to date. There are, however, certain problems in applying them. Application of a variety of different indicators

  8. Viability Assessment of a Repository at Yucca Mountain. Volume 2: Preliminary Design Concept for the Repository and Waste Package

    Energy Technology Data Exchange (ETDEWEB)

    None

    1998-12-01

    This volume describes the major design features of the Monitored Geologic Repository. This document is not intended to provide an exhaustive, detailed description of the repository design. Rather, this document summarizes the major systems and primary elements of the design that are radiologically significant, and references the specific technical documents and design analyses wherein the details can be found. Not all portions of the design are at the same level of completeness. Highest priority has been given to assigning resources to advance the design of the Monitored Geologic Repository features that are important to radiological safety and/or waste isolation and for which there is no NRC licensing precedent. Those features that are important to radiological safety and/or waste isolation, but for which there is an NRC precedent, receive second priority. Systems and features that have no impact on radiological safety or waste isolation receive the lowest priority. This prioritization process, referred to as binning, is discussed in more detail in Section 2.3. Not every subject discussed in this volume is given equal treatment with regard to the level of detail provided. For example, less detail is provided for the surface facility design than for the subsurface and waste package designs. This different level of detail is intentional. Greater detail is provided for those functions, structures, systems, and components that play key roles with regard to protecting radiological health and safety and that are not common to existing nuclear facilities already licensed by NRC. A number of radiological subjects are not addressed in the VA, (e.g., environmental qualification of equipment). Environmental qualification of equipment and other radiological safety considerations will be addressed in the LA. Non-radiological safety considerations such as silica dust control and other occupational safety considerations are considered equally important but are not addressed in

  9. Conceptual model for concrete long time degradation in a deep nuclear waste repository

    International Nuclear Information System (INIS)

    Lagerblad, B.; Traegaardh, J.

    1994-02-01

    This report is mainly a state-of-the-art report of concrete long time durability in the environment expected in a deep site underground nuclear waste repository in Swedish crystalline bedrock. The report treats how the concrete and the surrounding groundwater will interact and how they will be affected by cement chemistry, type of aggregate etc. The different mechanisms for concrete alteration treated include sulphate attack, carbonation, chloride attack, alkali-silica reaction and leaching phenomena. In a long time perspective, the chemical alterations in concrete is mainly governed by the surrounding groundwater composition. After closure the composition of the groundwater will change character from a modified meteoric to a saline composition. Therefore two different simulated groundwater compositions have been used in modelling the chemical interaction between concrete and groundwater. The report also includes a study of old and historical concrete which show observations concerning recrystallization phenomena in concrete. 72 refs, 39 figs

  10. Conceptual model for concrete long time degradation in a deep nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Lagerblad, B; Traegaardh, J [Swedish Cement and Concrete Research Inst., Stockholm (Sweden)

    1994-02-01

    This report is mainly a state-of-the-art report of concrete long time durability in the environment expected in a deep site underground nuclear waste repository in Swedish crystalline bedrock. The report treats how the concrete and the surrounding groundwater will interact and how they will be affected by cement chemistry, type of aggregate etc. The different mechanisms for concrete alteration treated include sulphate attack, carbonation, chloride attack, alkali-silica reaction and leaching phenomena. In a long time perspective, the chemical alterations in concrete is mainly governed by the surrounding groundwater composition. After closure the composition of the groundwater will change character from a modified meteoric to a saline composition. Therefore two different simulated groundwater compositions have been used in modelling the chemical interaction between concrete and groundwater. The report also includes a study of old and historical concrete which show observations concerning recrystallization phenomena in concrete. 72 refs, 39 figs.

  11. Development of models for use in the assessment of waste repository performance

    International Nuclear Information System (INIS)

    Dickson, A.G.; Weare, J.H.

    1989-01-01

    Any repository suitable for the disposal of radioactive waste comprises a combination of various man-made and natural barriers which aim to prevent transfer of the radionuclides from the canister to the external environment. Our group has developed the techniques needed to model the equilibrium chemistry of complex multicomponent rock/water systems over a range of ionic strengths and temperatures. These models, show remarkable agreement with field measurements when applied to natural systems. They have been applied successfully to interpret a variety of geochemical processes: studies of ancient and modern marine evaporite systems, studies of the solar evaporation of seawater studies of mineral formation in lakes and in fluid inclusions. At present our models are limited to the components of the seawater system (Na + , Mg 2+ , Ca 2+ , H + , SO 4 2- , HCO 3 - , CO 3 2- , CO 2 ), together with the borate species and SiO 2 . 2 tabs

  12. Natural analogues: studies of geological processes relevant to radioactive waste disposal in deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Russel, A.W. [Bedrock Geosciences, Auenstein (Switzerland); Reijonen, H.M. [Saanio and Rickkola Oy, Helsinki (Finland); McKinley, I.G. [MCM Consulting, Baden-Daettwil (Switzerland)

    2015-06-15

    The geological disposal of radioactive wastes is generally accepted to be the most practicable approach to handling the waste inventory built up from over 70 years accumulation of power production, research-medical-industrial and military wastes. Here, a brief overview of the approach to geological disposal is presented along with some information on repository design and the assessment of repository post-closure safety. One of the significant challenges for repository safety assessment is how to extrapolate the likely long-term (i.e. ten thousand to a million years) behaviour of the repository from the necessarily short term data from analytical laboratories and underground rock laboratories currently available. One approach, common to all fields of the geosciences, but also in such diverse fields as philosophy, biology, linguistics, law, etc., is to utilise the analogue argumentation methodology. For the specific case of radioactive waste management, the term 'natural analogue' has taken on a particular meaning associated with providing supporting arguments for a repository safety assessment. This approach is discussed here with a brief overview of how the study of natural (and, in particular, geological) systems can provide supporting information on the likely long-term evolution of a deep geological waste repository. The overall approach is discussed and some relevant examples are presented, including the use of uranium ore bodies to assess waste form stability, the investigation of native metals to define the longevity of waste containers and how natural clays can provide information on the stability of waste tunnel backfill material. (authors)

  13. Natural analogues: studies of geological processes relevant to radioactive waste disposal in deep geological repositories

    International Nuclear Information System (INIS)

    Russel, A.W.; Reijonen, H.M.; McKinley, I.G.

    2015-01-01

    The geological disposal of radioactive wastes is generally accepted to be the most practicable approach to handling the waste inventory built up from over 70 years accumulation of power production, research-medical-industrial and military wastes. Here, a brief overview of the approach to geological disposal is presented along with some information on repository design and the assessment of repository post-closure safety. One of the significant challenges for repository safety assessment is how to extrapolate the likely long-term (i.e. ten thousand to a million years) behaviour of the repository from the necessarily short term data from analytical laboratories and underground rock laboratories currently available. One approach, common to all fields of the geosciences, but also in such diverse fields as philosophy, biology, linguistics, law, etc., is to utilise the analogue argumentation methodology. For the specific case of radioactive waste management, the term 'natural analogue' has taken on a particular meaning associated with providing supporting arguments for a repository safety assessment. This approach is discussed here with a brief overview of how the study of natural (and, in particular, geological) systems can provide supporting information on the likely long-term evolution of a deep geological waste repository. The overall approach is discussed and some relevant examples are presented, including the use of uranium ore bodies to assess waste form stability, the investigation of native metals to define the longevity of waste containers and how natural clays can provide information on the stability of waste tunnel backfill material. (authors)

  14. Evaluation of site-generated radioactive waste treatment and disposal methods for the Yucca Mountain repository

    International Nuclear Information System (INIS)

    Subramanian, C.V.; Jardine, L.J.

    1989-01-01

    This study identifies the sources of radioactive wastes that may be generated at the proposed high-level waste (HLW) repository at Yucca Mountain, NV, estimates the waste quantities and characteristics, compares technologies available for waste treatment and disposal, and develops recommended concepts for site-generated waste treatment and disposal. The scope of this study is limited to operations during the emplacement phase, in which 70,000 MTU of high-level waste will be received and emplaced at the proposed repository. The evaluations consider all radioactive wastes generated during normal operations in surface and underground facilities. Wastes generated as a result of accidents are not addressed; accidents that could result in large quantities of radioactive waste are expected to occur very infrequently and temporary, portable systems could be used for any necessary cleanup. The results of this study can be used to develop more definitive plans for managing the site-generated wastes and as a basis for the design of associated facilities at the proposed repository

  15. Social and economical aspects in the selection of the site for the final Goiania waste repository

    International Nuclear Information System (INIS)

    Paschoa, A.S.; Tranjan Filho, A.; Rosenthal, J.J.

    2000-01-01

    Site selection criteria for low and intermediate level waste repositories are usually well established as far as the technological and scientific bases are concerned. However, social, cultural and economical aspects need to be examined on a case by case basis because there are many situations to be faced before succeeding to convince the public and authorities that a waste repository is to be built at any chosen site. In the specific case of Goiania there is an ongoing process that started several years ago, to make the repository accepted by local, state and national authorities, and to answer legitimate questions raised by significant segments of the population. This paper will summarise those more relevant aspects concerning the site selection process for the Goiania repository. (author)

  16. Design, construction, operation, shutdown and surveillance of repositories for solid radioactive wastes in shallow ground

    International Nuclear Information System (INIS)

    1984-01-01

    This report is a part of the IAEA publications under its Programme on Underground Disposal of Radioactive Wastes and is addressed to administrative and technical authorities and specialists who consider the shallow-ground disposal of low- and intermediate-level solid radioactive wastes of short half-lives. The report emphasizes the technological aspects, however it briefly discusses the safety philosophy and regulatory considerations too. The design, construction, operation, shutdown and surveillance of the repositories in shallow ground are considered in some detail, paying special attention to their interrelated aspects. In particular, a review is given of the following aspects: main design and construction considerations in relation to the natural features of the site; design and construction aspects during the repository development process; activities related to operational and post-operational stages of the repository; major steps in repository operation and essential activities in shutdown and operational and post-operational surveillance

  17. The influence of geological loading on the structural integrity of an underground nuclear waste repository

    International Nuclear Information System (INIS)

    Jakeman, N.

    1985-08-01

    Stresses are developed in underground nuclear waste repositories as a result of applied loads from geological movements caused by the encroachment of ice sheets or seismic activity for example. These stresses may induce fracturing of the waste matrix, repository vault and nearfield host geology. This fracturing will enhance the advective flow and allow more-rapid transfer of radionuclides from their encapsulation through the repository barriers and nearfield host rock. Geological loads may be applied either gradually as in crustal folding or encroachment of ice sheets, or rapidly as in the case of seismic movements. The analysis outlined in this report is conducted with a view to including the effects of geological loading in a probabilistic repository site assessment computer code such as SYVAC. (author)

  18. Designing shafts for handling high-level radioactive wastes in mined geologic repositories

    International Nuclear Information System (INIS)

    Hambley, D.F.; Morris, J.R.

    1988-01-01

    Waste package conceptual designs developed in the United States by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management are the basis for specifying the dimensions and weights of the waste package and transfer cask combinations to be hoisted in the waste handling shafts in mined geologic repositories for high-level radioactive waste. The hoist, conveyance, counterweight, and hoist ropes are then sized. Also taken into consideration are overwind and underwind arrestors and safety features required by the U.S. Nuclear Regulatory Commission. Other design features such as braking systems, chairing system design, and hoisting speed are considered in specifying waste hoisting system parameters for example repository sites

  19. Development of technical design for waste processing and storage facilities for Novi Han repository

    International Nuclear Information System (INIS)

    Canizares, J.; Benitez, J.C.; Asuar, O.; Yordanova, O.; Demireva, E.; Stefanova, I.

    2005-01-01

    Empresarion Agrupados Internacional S.A. (Spain) and ENPRO Consult Ltd. (Bulgaria) were awarded a contract by the Central Finance and Contracts Unit to develop the technical design of the waste processing and storage facilities at the Novi Han repository. At present conceptual design phase is finished. This conceptual design covers the definition of the basic design requirements to be applied to the installations defined above, following both European and Bulgarian legislation. In this paper the following items are considered: 1) Basic criteria for the layout and sizing of buildings; 2) Processing of radioactive waste, including: treatment and conditioning of disused sealed sources; treatment of liquid radioactive wastes; treatment of solid radioactive waste; conditioning of liquid and solid radioactive waste; 3) Control of waste packages and 4) Storage of radioactive waste, including storage facility and waste packages. An analysis of inventories of stored and estimated future wastes and its subsequent processes is also presented and the waste streams are illustrated

  20. Effects of heat from high-level waste on performance of deep geological repository components

    International Nuclear Information System (INIS)

    1984-11-01

    This report discusses the effects of heat on the deep geological repository systems and its different components. The report is focussed specifically on effects due to thermal energy release solely from high-level waste or spent fuel. It reviews the experimental data and theoretical models of the effects of heat both on the behaviour of engineered and natural barriers. A summary of the current status of research and repository development including underground test facilities is presented

  1. Summary report of first and foreign high-level waste repository concepts

    International Nuclear Information System (INIS)

    Hanke, P.M.

    1987-01-01

    Reference repository concepts designs adopted by domestic and foreign waste disposal programs are reviewed. Designs fall into three basic categories: deep borehole from the surface; disposal in boreholes drilled from underground excavations; and disposal in horizontal tunnels or drifts. The repository concepts developed in Sweden, Switzerland, Finland, Canada, France, Japan, United Kingdom, Belgium, Italy, Holland, Denmark, West Germany and the United States are described. 140 refs., 315 figs., 19 tabs

  2. Effective summary evaluators for deep nuclear waste repositories: geohydrologic response function

    International Nuclear Information System (INIS)

    Nelson, R.W.; Dove, F.H.

    1981-03-01

    Useful insight has been gained over the past four years as hydrologic system modeling has been applied to evaluate hypothetical, waste-repository sites in various geologic media. The Geohydrologic Response Functions, described in this paper, are shown to: blend extensive results of technical analysis into simple summary relationships, and to potentially help the public and decision makers to evaluate the magnitude of any loss in repository integrity

  3. Waste Disposal: Processes Taking Place (on the way) from the Repository to the Biosphere

    International Nuclear Information System (INIS)

    Put, M.

    2000-01-01

    The main objective of SCK-CEN's R and D programme on the processes taking place on the way from the repository to the biosphere is to provide reliable and defensible models and parameters on the migration of dissolved radionuclides and gases through the host formation (Boom Clay) and the backfill materials of a deep geological repository for high level radioactive waste. The programme and main achievements in this topical area in 1999 are summarised

  4. Development of site suitability criteria for the high level waste repository for Lawrence Livermore Laboratories

    International Nuclear Information System (INIS)

    1977-06-01

    Results of our mining, geological and geotechnical studies provided in support of the development of site suitability criteria for the high level waste repository are presented. The primary purpose of the work was the identification and development of appropriate geotechnical descriptors and coefficients required for the Site Suitability Repository Model. This model was developed by The Analytic Sciences Corporation (TASC) of Reading, Massachusetts and is not described in this report

  5. A performance goal-based seismic design philosophy for waste repository facilities

    International Nuclear Information System (INIS)

    Hossain, Q.A.

    1994-01-01

    A performance goal-based seismic design philosophy, compatible with DOE's present natural phenomena hazards mitigation and open-quotes graded approachclose quotes philosophy, has been proposed for high level nuclear waste repository facilities. The rationale, evolution, and the desirable features of this method have been described. Why and how the method should and can be applied to the design of a repository facility are also discussed

  6. Development of site suitability criteria for the high level waste repository for Lawrence Livermore Laboratories

    Energy Technology Data Exchange (ETDEWEB)

    1977-06-01

    Results of our mining, geological and geotechnical studies provided in support of the development of site suitability criteria for the high level waste repository are presented. The primary purpose of the work was the identification and development of appropriate geotechnical descriptors and coefficients required for the Site Suitability Repository Model. This model was developed by The Analytic Sciences Corporation (TASC) of Reading, Massachusetts and is not described in this report.

  7. Human intrusion into geologic repositories for high-level radioactive waste: potential and prevention

    Energy Technology Data Exchange (ETDEWEB)

    Cameron, F X [Nuclear Regulatory Commission, Washington, DC (USA). Office of Nuclear Regulatory Research

    1981-12-01

    Isolation of high-level radioactive waste over long periods of time requires protection not only from natural events and processes, but also from the deliberate or inadvertent activities of future societies. This paper evaluates the likelihood of inadvertent human intrusion due to the loss of societal memory of the repository site. In addition measures to prevent inadvertent intrusion, and to guide future societies in any decision to deliberately intrude into the repository are suggested.

  8. Modelling of the degradation of cement in a nuclear waste repository

    International Nuclear Information System (INIS)

    Haworth, A.; Sharland, S.M.; Tweed, C.J.

    1989-01-01

    The current UK concept for a low- or intermediate-level nuclear waste repository includes a largely cementitious backfill. The cement provides a high pH environment in which the general corrosion rate of the metal canisters is reduced and the solubilities of many nuclides low. It has previously been assumed that this high pH will exist for a period of 10 7 years, however cement will degrade due to leaching of the solid components and attack from aqueous species in groundwater. In this paper the authors describe the preliminary stages of a model of the degradation of cement in a repository. The modelling involves the incorporation of a thermodynamic description of cement into the static code PHREEQE. This is then used in a coupled chemistry-transport model of simple leaching of cement using the code CHEQMATE. This preliminary modelling also provides a useful verification of CHEQMATE as a direct comparison with a THCCDM (a coupled code based on CHEMTRN) model is possible. Results from this preliminary model suggest that the fall in pH due to leaching is slow

  9. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    International Nuclear Information System (INIS)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed

  10. Engineered barrier development for a nuclear waste repository in basalt: an integration of current knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Smith, M.J.

    1980-05-01

    This document represents a compilation of data and interpretive studies conducted as part of the engineered barriers program of the Basalt Waste Isolation Project. The overall objective of these studies is to provide information on barrier system designs, emplacement and isolation techniques, and chemical reactions expected in a nuclear waste repository located in the basalts underlying the Hanford Site within the state of Washington. Backfills, waste-basalt interactions, sorption, borehole plugging, etc., are among the topics discussed.

  11. The Konrad mine - the planned German repository for radioactive waste with negligible heat generation

    International Nuclear Information System (INIS)

    Berg, H.P.; Brennecke, P.

    1990-07-01

    This report deals with the planned Konrad repository and describes the current state of affairs. In particular, the technical concept is explained and a survey of the radioactive waste intended for disposal is given. The safety assessments which have been made, including the derivation of preliminary waste acceptance requirements, are described and the principles of the waste package control are outlined. (orig./HP) [de

  12. Closure development for high-level nuclear waste containers for the tuff repository

    International Nuclear Information System (INIS)

    Robitz, E.S. Jr.; McAninch, M.D. Jr.; Edmonds, D.P.; Babcock and Wilcox Co., Alliance, OH

    1990-09-01

    This report summarizes Phase 1 activities for closure development of the high-level nuclear waste package task for the tuff repository. Work was conducted under U.S. Department of Energy (DOE) Contract 9172105, administered through the Lawrence Livermore National Laboratory (LLNL), as part of the Yucca Mountain Project (YMP), funded through the DOE Office of Civilian Radioactive Waste Management (OCRWM). The goal of this phase was to select five closure processes for further evaluation in later phases of the program. A decision tree methodology was utilized to perform an objective evaluation of 15 potential closure processes. Information was gathered via a literature survey, industrial contacts, and discussions with project team members, other experts in the field, and the LLNL waste package task staff. The five processes selected were friction welding, electron beam welding, laser beam welding, gas tungsten arc welding, and plasma arc welding. These are felt to represent the best combination of weldment material properties and process performance in a remote, radioactive environment. Conceptual designs have been generated for these processes to illustrate how they would be implemented in practice. Homopolar resistance welding was included in the Phase 1 analysis, and developments in this process will be monitored via literature in Phases 2 and 3. Work was conducted in accordance with the YMP Quality Assurance Program. 223 refs., 20 figs., 9 tabs

  13. Fault Frictional Stability in a Nuclear Waste Repository

    Science.gov (United States)

    Orellana, Felipe; Violay, Marie; Scuderi, Marco; Collettini, Cristiano

    2016-04-01

    Exploitation of underground resources induces hydro-mechanical and chemical perturbations in the rock mass. In response to such disturbances, seismic events might occur, affecting the safety of the whole engineering system. The Mont Terri Rock Laboratory is an underground infrastructure devoted to the study of geological disposal of nuclear waste in Switzerland. At the site, it is intersected by large fault zones of about 0.8 - 3 m in thickness and the host rock formation is a shale rock named Opalinus Clay (OPA). The mineralogy of OPA includes a high content of phyllosilicates (50%), quartz (25%), calcite (15%), and smaller proportions of siderite and pyrite. OPA is a stiff, low permeable rock (2×10-18 m2), and its mechanical behaviour is strongly affected by the anisotropy induced by bedding planes. The evaluation of fault stability and associated fault slip behaviour (i.e. seismic vs. aseismic) is a major issue in order to ensure the long-term safety and operation of the repository. Consequently, experiments devoted to understand the frictional behaviour of OPA have been performed in the biaxial apparatus "BRAVA", recently developed at INGV. Simulated fault gouge obtained from intact OPA samples, were deformed at different normal stresses (from 4 to 30 MPa), under dry and fluid-saturated conditions. To estimate the frictional stability, the velocity-dependence of friction was evaluated during velocity steps tests (1-300 μm/s). Slide-hold-slide tests were performed (1-3000 s) to measure the amount of frictional healing. The collected data were subsequently modelled with the Ruina's slip dependent formulation of the rate and state friction constitutive equations. To understand the deformation mechanism, the microstructures of the sheared gouge were analysed. At 7 MPa normal stress and under dry conditions, the friction coefficient decreased from a peak value of μpeak,dry = 0.57 to μss,dry = 0.50. Under fluid-saturated conditions and same normal stress, the

  14. Geological investigations for the South African nuclear waste repository facility

    International Nuclear Information System (INIS)

    Hambleton-Jones, B.B.; Levin, M.; Andersen, N.J.B.; Brynard, H.J.; Toens, P.D.

    1984-02-01

    The selection of the Vaalputs site on the arid Bushmanland Plateau in the northwestern Cape of the Republic of South Africa for the disposal of low-level radioactive waste was based on a national screening phase program involving socio-economic and geological criteria. Regional geohydrological studies over an area of 27,000 km 2 and a detailed study over 1,300 km 2 indicated that in general the groundwater is saline and that Vaalputs and environs was the most favourable area. The groundwater table lies between 30 and 45 m below the surface, with 14 C ages between 2,500 and 9,000 years old in the immediate vicinity. The geology of Vaalputs consists of Proterozoic granites, gneisses, metasediments, and noritoids of the 1,050 Ma Namaqualand Metamorphic Complex. Upper cretaceous kimberlitic and basaltic intrusions occur locally. Overlying these basement rocks surficial upper Tertiary to Recent argillaceous sediments occur in the Vaalputs basin. The sediments consist of aeolian sand, calcrete, fluvial sandy to gritty clay, white kaolinised clay and very weathered basement rocks. It is in these rocks that the low-level waste trenches will be located. Extensive airborne geophysical surveys, such as aeromagnetics, INPUT, and infrared thermal line scanning, were undertaken to assist in the evaluation of the regional and local subsurface geology. Ground geophysical surveys included refraction seismics, electromagnetics, magnetics, borehole radiometrics and resistivity. Geohydrological modelling of the unsaturated and saturated zones is in progress

  15. Improvement of storage conditions and closure of the radioactive waste repository - Rozan

    International Nuclear Information System (INIS)

    Dutton, L.M.C.; Pacey, N.R.; Buckley, M.J.; Thomson, J.G.; Miller, W.; Barraclough, I.; Tomczak, W.; Mitrega, J.; Smietanski, L.

    2005-01-01

    The Rozan repository is a near-surface repository on the site of an ex-military fort, operated by Radioactive Waste Management Plant (RWMP). Solid or encapsulated waste is consigned to the repository. Low- and medium-activity waste produced in Poland is collected, processed, solidified and prepared for disposal at the Swierk facility. The waste is currently stored or disposed of within the fort structures, these have robust concrete walls, that provide both shielding and containment. The project, funded by the European Commission through the Phare Programme, aimed to improve the storage conditions and determine a strategy for closure achieving two key results; Stakeholder agreement to a strategy for the management and closure of the repository, and; Approval by the National Atomic Energy Agency of the safety case for the selected strategy. The strategy was selected using a multi-criteria analysis methodology at workshops that involved experts, regulators and other stakeholders. The selected strategy proposed that the waste in Facilities 3A and 8 should be left in situ and these facilities should continue to operate until the repository is closed. The waste in Rooms K7 to K9 of Facility 1 and in Facilities 2 and 3 should be retrieved, assayed, treated and packaged prior to redisposal. The short-lived waste that is retrieved from Rooms K7 to K9 of Facility 1 and Facilities 2 and 3 should be emplaced in Facility 8 subject to acceptance by the NAEA of the dose of 0.3mSv/y that might occur at long times in the future from a very unlikely scenario. When operations at the repository end, Facilities 3A and 8 should be covered with a multi-layer cap. Following selection of the strategy, assessment work was undertaken to support the production of the suite of safety cases. (author)

  16. Influence of Groundwater Flow Rate on Nuclide Releases from Pyro-processed Waste Repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Jeong, Jong Tae

    2011-01-01

    Since the early 2000s several template programs for the safety assessment of a high-level radioactive waste repository as well as a low- and intermediate level radioactive waste repository systems have been developed by utilizing GoldSim and AMBER at KAERI. Very recently, another template program for a conceptual hybrid-typed repository system, called 'A-KRS' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from pyroprocessing of PWR nuclear spent fuels has been developed and are to be disposed of by separate disposal strategies. The A-KRS is considered to be constructed at two different depths in geological media: 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and 500m depth, believed to be in the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of waste package and canister. To quantify a nuclide release and transport through the possible various pathways especially in the near-fields of the A-KRS repository system, some illustrative evaluations have been made through the study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

  17. General conceptual design study for a high-level radioactive waste repository in a granite formation

    International Nuclear Information System (INIS)

    1982-01-01

    The object of the general conceptual design study for a high level radioactive wastes repository in a deep lying granite formation is to ensure that technology available in 1980 is suitable for building, operating and finally closing such a repository. It is feasible to build and operate a 1000 m deep repository, located in a granite batholith, receiving 30000 AVM canisters (after 30 years surface cooling), the disposal rate being 1000 canisters per year. Cost of the operation amounts to 1,3% of the corresponding amount of electricity. The building, operating and final closing phases will take 81 years

  18. Importance of creep failure of hard rock in the near field of a nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Blacic, J D [Los Alamos National Laboratory, NM, (USA)

    1982-12-31

    Potential damage resulting from slow creep deformation intuitively seems unlikely for a high-level nuclear waste repository excavated in hard rock. However, recent experimental and modeling results indicate that the processes of time-dependent microcracking and water-induced stress corrosion can lead to significant reductions in strength and alteration of other key rock properties in the near-field region of a repository. We review the small data base supporting these conclusions and stress the need for an extensive laboratory program to obtain the new data that will be required for design of a repository.

  19. Global nuclear waste repository proposal highlights Australia`s nuclear energy vacuum

    Energy Technology Data Exchange (ETDEWEB)

    Anon.

    1999-06-01

    The Pangea proposal is disscused and considered relevant to Australia. A five-year research program by the company has identified Australia and Argentina as having the appropriate geological, economic and democratic credentials for such a deep repository, with Australia being favoured. A deep repository would be located where the geology has been stable for several hundred million years, so that there need not be total reliance on a robust engineered barrier system to keep the waste securely isolated for thousands of years. It would be a commercial undertaking and would have dedicated port and rail infrastructure. It would take spent fuel and other wastes from commercial reactors, and possibly also waste from weapons disposal programs. Clearly, while the primary ethical and legal principle is that each country is entirely responsible for its own waste, including nuclear waste (polluter pays etc), the big question is whether the concept of an international waste repository is acceptable ethically. Political and economic questions are secondary to this. By taking a fresh look at the reasons for the difficulties which have faced most national repository programs, and discarding the preconception that each country must develop its own disposal facilities, it is possible to define a class of simple, superior high isolation sites which may provide a multi-national basis for solving the nuclear waste disposal problem. The relatively small volumes of high-level wastes or spent fuel which arise from nuclear power production make shared repositories a feasible proposition. For small countries, the economies of scale which can be achieved make the concept attractive. For all countries, objective consideration of the relative merits of national and multi-national solutions is a prudent part of planning the management of long-lived radioactive wastes

  20. Review of the potential effects of alkaline plume migration from a cementitious repository for radioactive waste

    International Nuclear Information System (INIS)

    Savage, D.

    1997-01-01

    Extensive use of cement and concrete is envisaged in the construction of geological repositories for low and intermediate-level radioactive wastes, both for structural, and encapsulation and backfilling purposes. Saturation of these materials with groundwater may occur in the post-closure period of disposal, producing a hyperalkaline pore fluid with a pH in the range 10-13.5. These pore fluids have the potential to migrate from the repository according to local groundwater flow conditions and react chemically with the host rock. These chemical reactions may affect the rock's capacity to retard the migration of radionuclides released from the repository after the degradation of the waste packages. The effects of these chemical reactions on the behaviour of the repository rock as a barrier to waste migration need to be investigated for the purposes of assessing the safety of the repository design (so-called 'safety assessment' or 'performance assessment'). The objectives of the work reported here were to: identify those processes influencing radionuclide mobility in the geosphere which could be affected by plume migration; review literature relevant to alkali-rock reaction; contact organisations carrying out relevant research and summarise their current and future activities; and make recommendations how the effects of plume migration can be incorporated into models of repository performance assessment. (author)

  1. Some reflections on human intrusion into a nuclear waste repository

    International Nuclear Information System (INIS)

    Westerlind, M.

    2002-01-01

    This paper summarises some of the Swedish nuclear regulators' requirements and views related to intrusion into a repository for spent nuclear fuel, in the post-closure phase. The focus is however on experiences from the interaction with various stakeholders in the Swedish process for siting a repository. It is recognised that intrusion is not a major concern but that it is regularly raised in the debate, often in connection with issues related to retrievability. It is pointed out that more attention should be paid to the repository performance after an intrusion event, both in safety assessments and in communication with stakeholders, and not only address the immediate impacts to intruders. It is believed that international co-operation would be useful for developing methodologies for defining intrusion scenarios. (author)

  2. Potential impact of Andrassy bentonite microbial diversity in the long-term performance of a deep nuclear waste repository

    Science.gov (United States)

    Tadza, M. Y. Mohd; Tadza, M. A. Mohd; Bag, R.; Harith, N. S. H.

    2018-01-01

    Copper and steel canning and bentonite buffer are normally forseen as the primary containment component of a deep nuclear waste repository. Distribution of microbes in subsurface environments have been found to be extensive and directly or indirectly may exert influence on waste canister corrosion and the mobility of radionuclides. The understanding of clays and microbial interaction with radionuclides will be useful in predicting the microbial impacts on the performance of the waste repositories. The present work characterizes the culture-dependent microbial diversity of Andrassy bentonite recovered from Tawau clay deposits. The evaluation of microbial populations shows the presence of a number of cultivable microbes (e.g. Staphylococcus, Micrococcus, Achromobacter, Bacillus, Paecilomyces, Trichoderma, and Fusarium). Additionally, a pigmented yeast strain Rhodotorula mucilaginosa was also recovered from the formation. Both Bacillus and Rhodotorula mucilaginosa have high tolerance towards U radiation and toxicity. The presence of Rhodotorula mucilaginosa in Andrassy bentonite might be able to change the speciation of radionuclides (e.g. uranium) in a future deep repository. However, concern over the presence of Fe (III) reduction microbes such as Bacillus also found in the formation could lead to corrosion of copper steel canister and affect the overall performance of the containment system.

  3. National waste terminal storage conceptual reference repository description

    International Nuclear Information System (INIS)

    Odgers, I.L.; Collings, J.L.

    1981-01-01

    The conceptual reference repository description (CRRD) discusses, from a conceptual engineering standpoint, the structures, systems, equipment, and operations necessary to: (1) receive unreprocessed spent fuel assemblies in standard casks; (2) unload these assemblies; (3) place them in canisters; (4) transport the canisters to underground storage locations in the salt dome; and (5) place the canisters in terminal storage. The CRRD also elaborates on the concepts for retrieval and recovery of the spent fuel after burial and describes the development of the shafts and the underground areas, as well as the supporting operational utility and administrative features of the repository

  4. Retrieval effects on ventilation and cooling requirements for a nuclear waste repository

    International Nuclear Information System (INIS)

    Hambley, D.F.

    1985-01-01

    The Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the regulations promulgated in Title 10, Part 60 of the Code of Federal Regulations (10CFR60) by the US Nuclear Regulatory Commission (NRC) for an underground repository for spent fuel and high level nuclear waste (HLW) require that it is possible to retrieve waste, for whatever reason, from such a facility for a period of 50 years from initial storage or until the completion of the performance confirmation period, whichever comes first. This paper considers the effects that the retrievability option mandates on ventilation and cooling systems required for normal repository operations. An example is given for a hypothetical repository in salt. 18 refs., 1 tab

  5. A Deterministic Safety Assessment of a Pyro-processed Waste Repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Jeong, Jong Tae; Choi, Jong Won

    2012-01-01

    A GoldSim template program for a safety assessment of a hybrid-typed repository system, called 'A-KRS', in which two kinds of pyro-processed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyro-processing of PWR nuclear spent fuels are disposed of, has been developed. This program is ready both for a deterministic and probabilistic total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios. The A-KRS has been deterministically assessed with 5 various normal and abnormal scenarios associated with nuclide release and transport in and around the repository. Dose exposure rates to the farming exposure group have been evaluated in accordance with all the scenarios and then compared among other.

  6. Evolution of waste-package design at the potential U.S. geologic repository

    International Nuclear Information System (INIS)

    Benton, H.; Harkins, B.

    2000-01-01

    This paper describes the evolution of the waste-package design at the potential geologic repository for spent nuclear fuel and high-level waste at Yucca Mountain in Nevada. Because the potential repository is the first of its kind, the design of its components must be flexible and capable of evolving in response to continuing scientific study, development efforts, and changes to performance criteria. The team of scientists and engineers at the Yucca Mountain Project has utilized a systematic, scientific approach to design the potential geologic nuclear-waste repository. As a result of continuing development efforts, the design has incorporated a growing base of scientific and engineering information to ensure that regulatory and performance requirements are met. (authors)

  7. Second generation waste package design and storage concept for the Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Armijo, Joseph Sam; Kar, Piyush; Misra, Manoranjan

    2006-01-01

    The reference waste package design and operating mode to be used in the Yucca Mountain Repository is reviewed. An alternate (second generation) operating concept and waste package design is proposed to reduce the risk of localized corrosion of waste packages and to reduce repository costs. The second generation waste package design and storage concept is proposed for implementation after the initial licensing and operation of the reference repository design. Implementation of the second generation concept at Yucca Mountain would follow regulatory processes analogous to those used successfully to extend the design life and uprate the power of commercial light water nuclear reactors in the United States. The second generation concept utilizes the benefits of hot dry storage to minimize the potential for localized corrosion of the waste package by liquid electrolytes. The second generation concept permits major reductions in repository costs by increasing the number of fuel assemblies stored in each waste package, by eliminating the need for titanium drip shields and by fabricating the outer container from corrosion resistant low alloy carbon steel

  8. Nye County, Nevada 1992 nuclear waste repository program: Program overview. Final report

    International Nuclear Information System (INIS)

    1998-01-01

    The purpose of this document is to provide an overview of the Nye County FY92 Nuclear Waste Repository Program (Program). Funds to pay for Program costs will come from the Federal Nuclear Waste Fund, which was established under the Nuclear Waste Policy Act of 1982 (NWPA). In early 1983, the Yucca Mountain was identified as a potentially suitable site for the nation's first geologic repository for spent reactor fuel and high-level radioactive waste. Later that year, the Nye County Board of County Commissioners (Board) established the capability to monitor the Federal effort to implement the NWPA and evaluate the potential impacts of repository-related activities on Nye County. Over the last eight years, the County's program has grown in complexity and cost in order to address DOE's evolving site characterization studies, and prepare for the potential for facility construction and operation. Changes were necessary as well, in response to Congress's redirection of the repository program specified in the amendments, to the NWPA approved in 1987. In early FY 1991, the County formally established a project office to plan and implement its program of work. The Repository Project Office's (RPO) mission and functions are provided in Section 2.0. The RPO organization structure is described in Section 3.0

  9. Appraisal of hard rock for potential underground repositories of radioactive wastes

    International Nuclear Information System (INIS)

    Cook, N.G.W.

    1977-10-01

    The mechanical safety and stability of such an underground repository depends largely on the virgin state of stress in the rock, groundwater pressures, the strengths of the rocks, heating by the decay of the radioactive wastes, and the layout of the excavations and the disposition of waste cannisters within them. A large body of pertinent data exists in the literature, and each of these factors has been analyzed in the light of this information. The results indicate that there are no fundamental geological nor mechanical reasons why repositories capable of storing radioactive wastes should not be excavated at suitable sites in hard rock. However, specific tests to determine the mechanical and thermal properties of the rocks at a site would be needed to provide the data for the engineering design of a repository. Also, little experience exists of the effects on underground excavations of thermal loads, so that this aspect requires theoretical study and experimental validation. The depths of these potential repositories would lie in the range from 0.5 to 2.0 km below surface, depending upon the strength of the rock. Virgin states of stress have been measured at such depths which would retard the ingress of groundwater and obviate the incidence of faulting. A typical repository comprising three horizons each with a total area of 5 km 2 would have the capacity to store wastes with thermal output of 240 MW

  10. Postclosure risks of alternative SRP nuclear waste forms in geologic repositories

    International Nuclear Information System (INIS)

    Cheung, H.; Edwards, L.; Harvey, T.; Revelli, M.

    1982-05-01

    The postclosure risk of REFERENCE and ALTERNATIVE waste forms for the defense high-level waste at the Savannah River Plant (SRP) were compared by analyses with a computer code, MISER, written to study the effects of repository features in a probabilistic framework. MISER traces radionuclide flows through a network of stream tubes from the repository to risk-sensitive points. Uncertainties in waste form, package properties, and geotechnical data are accounted for with Monte Carlo techniques. Our results show: (1) for generic layered-salt and basalt repositories, the difference in performance between the two waste forms is insignificant; (2) where the doses are sensitive to uncertainties in leaching rates, the doses are orders of magnitude below background; (3) disruptive events contribute only slightly to the risk of a layered-salt repository; (4) simple design alterations have strong effects on near field doses; (5) great care should be exercised in selecting the location at which repository risks are to be measured, calculated, or regulated

  11. Politics and technology in repository siting: military versus commercial nuclear wastes at WIPP 1972-1985

    International Nuclear Information System (INIS)

    Downey, G.L.

    1985-01-01

    During the 1970s, attempts by the federal government to develop a comprehensive system for disposing of nuclear wastes in geologic repositories were plagued by two related political problems; (1) whether or not military and commercial wastes should be buried together in the same repository, and (2) how to define the host state's role in the repository siting mechanism. This article explains why these two problems were connected by showing how they proved to be of decisive importance in the development of the Waste Isolation Pilot Plant (WIPP) project in Carlsbad, New Mexico. Although WIPP was initially conceived as a wholly military facility, The Department of Energy triggered a three-year dispute over the project's scope by proposing in 1978 to include commercial wastes in the repository. The key issue in the dispute concerned the political legitimacy of decision-making mechanisms for repository siting, which depend upon the extent to which they both adequately represent the interests of affected groups and meet an indistinct technical/political criterion of acceptable safety. DOE's ill-fated proposal to mix military and commercial disposal at WIPP demonstrated that the two rely on somewhat different conditions for their legitimacy. The agency overlapped the legitimate authorities of the federal and state governments and gave itself the hopeless task of negotiating a new boundary between them. 50 references, 3 figures

  12. Long Term Behaviour of Cementitious Materials in the Korean Repository Environment

    International Nuclear Information System (INIS)

    Park, J.-W.; Kim, C.-L.

    2013-01-01

    The safe management of radioactive waste is a national task required for sustainable generation of nuclear power and for energy self-reliance in Korea. After the selection of the final candidate site for low- and intermediate-level waste (LILW) disposal in Korea, a construction and operation license was issued for the Wolsong LILW Disposal Center (WLDC) for the first stage of disposal. Underground silo type disposal has been determined for the initial phase. The engineered barrier system of the disposal silo consists of waste packages, disposal containers, backfills, and a concrete lining. Main objective of our study in this IAEA-CRP is to investigate closure concepts and cementitious backfill materials for the closure of silos. For this purpose, characterisation of cementitious materials, development of silo closure concept, and evaluation of long-term behaviour of cementitious materials, including concrete degradation in repository environment, have been carried out. The overall implementation plan for the CRP comprises performance testing for the physic-chemical properties of cementitious materials, degradation modelling of concrete structures, comparisons of performance for silo closure options, radionuclide transport modelling (considering concrete degradation in repository conditions), and the implementation of an input parameter database and quality assurance for safety/performance assessment. In particular, the concrete degradation modelling study has been focused on the corrosion of reinforcement steel induced by chloride attack, which was of primary concern in the safety assessment of the WLDC. A series of electrochemical experiments were conducted to investigate the effect of dissolved oxygen, pH, and Cl on the corrosion rate of reinforcing steel in a concrete structure saturated with groundwater. Laboratory-scale experiments and a thermodynamic modelling were performed to understand the porosity change of cement pastes, which were prepared using

  13. The enhancement of a biosphere code for use in the assessment of deep repositories for radioactive waste

    International Nuclear Information System (INIS)

    Ashton, J.; Little, R.H.

    1991-01-01

    A disposal system for radioactive waste is conventionally considered to consist of the engineered barriers of the repository, the geosphere and the surface environment or biosphere. Computer codes have been developed to assist in assessing the impact of radionuclides migrating from the repository through the disposal system. Codes have been developed to represent the repository, the geosphere and the biosphere. The fundamental role of the biosphere codes is, for radionuclide inputs, to estimate the dose, or probability distribution function of dose, to a maximally exposed individual as a function of time. In the United Kingdom, the primary target for long-term radiological impacts from a single disposal facility is that the risk of fatal cancer to an individual in any one year should not exceed one in a million at any time. The recent revival of interest in the UK in the deep disposal of radioactive waste has resulted in the need for the risk to be estimated over timescales up to a million years, since a deep geologic repository might be able to withstand the effects of several future glacial episodes. Biosphere modelling for deep disposal of radioactive waste poses particular problems since the surface environment is expected to evolve as a result of changes in climatic conditions. Consequently the effect of climate induced changes in geomorphology, land use and sea level on the calculated risk have to be considered. This paper outlines the development of a new version of the dynamic biosphere model DECOS, which was developed originally in the context of shallow site assessments. The new version of the code, called DECOS-MG, is capable of simulating the effect of multiple glacial cycles and changes in sea level. (14 refs., 3 figs., 2 tabs.)

  14. Draft environmental assessment: reference repository location, Hanford Site, Washington. Nuclear Waste Policy Act (Section 112)

    International Nuclear Information System (INIS)

    1984-12-01

    In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the reference repository location at the Hanford Site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received on the draft EA. The reference repository location at Hanford is located in the Columbia Plateau, one of five distinct geohydrologic settings that are being considered for the first repository. On the basis of the evaluations reported in this draft EA, the DOE has found that the reference repository location at Hanford is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is proposing to nominate the reference repository location at Hanford as one of five sites suitable for characterization. Furthermore, having performed a comparative evaluation of the five sites proposed for nomination, the DOE has determined that the reference repository location at Hanford is one of three sites preferred for site characterization

  15. Selection of the host rock for high level radioactive waste repository in China

    International Nuclear Information System (INIS)

    Jin Yuanxin; Wang Wenguang; Chen Zhangru

    2001-01-01

    The authors has briefly introduced the experiences of the host rock selection and the host rock types in other countries for high level radioactive waste repository. The potential host rocks in China are investigated. They include granite, tuff, clay, basalt, salt, and loess. The report has expounded the distributions, scale, thickness, mineral and chemical composition, construction, petrogenesis and the ages of the rock. The possibility of these rocks as the host rock has been studied. The six pieces of distribution map of potential rocks have been made up. Through the synthetical study, it is considered that granite as the host rock of high level radioactive waste repository is possible

  16. Barriers of repository under the conditions of underground isolation of heat releasing radioactive waste in permafrost

    International Nuclear Information System (INIS)

    Kazakov, A.N.; Fedorovich, L.N.

    1995-01-01

    The main positions and the leading principle of the ensuring of the environmental safety of the method of the underground isolation of radioactive waste in permafrost rock are presented in this work and it is shown here the peculiarities in realization of the principle of the multibarrier protection. It is substantiated here the principle of the optimal time of the capacity for work of the repository's engineered barriers. The possibility of the exclusion of the radionuclides migration beyond the working volume of the repository during the time of the potential danger of radioactive waste is also substantiated in these papers

  17. Composition of Whiskers Grown on Copper in Repository Environment

    International Nuclear Information System (INIS)

    Hermansson, Hans-Peter; Tarkpea, Peeter; Holgersson, Stellan

    2001-11-01

    There is a hypothesis that a special family of local attack on copper based on growth of whiskers of sulfide, oxide/hydroxide and also carbonate/malachite could appear in the repository environment. It was earlier demonstrated that such whiskers could grow in a laboratory simulated repository environment, containing sulfide. A suggested composition of whiskers has earlier been forwarded but was not demonstrated. In the present work whiskers and their substrates were grown and characterized by investigations with a combination of SEM-EDS, XRD and LRS (Laser Raman Spectroscopy) techniques. SEM-EDS was used to determine the morphology and an elemental composition and distribution of whiskers and their substrate. A special effort was made to find out if the whisker growth is of a local or global character. The phase status could be determined locally and globally by combining XRD and LRS techniques on whiskers and substrates. Ideally, LRS gives a phase resolution down to a radius of 1 μm on the sample surface. This is of great value as it is of interest to study if there are phase differences in different parts of a whisker. Such information is important to understand the whisker growth mechanism. Cylindrical samples of pure copper were prepared and exposed to the selected de-aerated model groundwater containing, among other ions, chloride and sulfide. Exposure was performed in sealed glass flasks under de-aerated conditions. After exposure the copper sample was investigated on the surface, in cross section and on whiskers using the mentioned techniques. The results show that a black, easily detached layer of corrosion products is formed on the sample surface. The corrosion layer was subdivided into at least five parallel strata (probably more) of different composition. Numerous small pits and shallow pitting attacks with a larger radius were observed in the copper metal and the metal surface was in general very rough. A multitude of very easily detached whiskers or

  18. Rad waste disposal safety analysis / Integrated safety assessment of a waste repository

    International Nuclear Information System (INIS)

    Jeong, Jongtae; Choi, Jongwon; Kang, Chulhyung

    2012-04-01

    We developed CYPRUS+and adopted PID and RES method for the development of scenario. Safety performance assessment program was developed using GoldSim for the safety assessment of disposal system for the disposal of spnet fuels and wastes resulting from the pyrpoprocessing. Biosphere model was developed and verified in cooperation with JAEA. The capability to evaluate post-closure performance and safety was added to the previously developed program. And, nuclide migration and release to the biosphere considering site characteristics was evaluated by using deterministic and probabilistic approach. Operational safety assessment for drop, fire, and earthquake was also statistically evaluated considering well-established input parameter distribution. Conservative assessment showed that dose rate is below the limit value of low- and intermediate-level repository. Gas generation mechanism within engineered barrier was defined and its influence on safety was evaluated. We made probabilistic safety assessment by obtaining the probability distribution functions of important input variables and also made a sensitivity analysis. The maximum annual dose rate was shown to be below the safety limit value of 10 mSv/yr. The structure and element of safety case was developed to increase reliability of safety assessment methodology for a deep geological repository. Finally, milestone for safety case development and implementation strategy for each safety case element was also proposed

  19. Release consequence analysis for a hypothetical geologic radioactive waste repository in salt

    International Nuclear Information System (INIS)

    1979-08-01

    One subtask conducted under the INFCE program is to evaluate and compare the health and safety impacts of different fuel cycles in which all radioactive wastes (except those from mining and milling) are placed in a geologic repository in salt. To achieve this objective, INFCE Working Group 7 examined the radiologic dose to humans from geologic repositories containing waste arisings as defined for seven reference fuel cycles. This report examines the release consequences for a generic waste repository in bedded salt. The top of the salt formation and the top of the repository are assumed to be 250 and 600 m, respectively, below the surface. The hydrogeologic structure above the salt consists of two aquifers and two aquitards. The aquifers connect to a river 6.2 km from the repository. The regional gradient to the river is 1 m/km in all aquifers. Hydrologic, transport, and dose models were used to model two release scenarios for each fuel cycle, one without a major disturbance and one in which a major geologic perturbation breached the repository immediately after it was sealed. The purpose of the modeling was to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere, and to determine the potential dose to humans. Of the many radionuclides in the waste, only 129 I and 226 Ra arrived at the river in sufficient concentrations for a measurable dose calculation. Radionuclide concentrations in the ground water pose no threat to man because the ground water is a concentrated brine and it is diluted by a factor of 10 6 to 10 7 upon entering the river

  20. Project Guarantee 1985. Repository for low- and intermediate-level radioactive waste: construction and operation

    International Nuclear Information System (INIS)

    Anon.

    1985-01-01

    A constructional engineering project study aimed at clarification of the feasibility of a repository for low- and intermediate-level radioactive waste (type B repository) has been carried out; the study is based on a model data-set derived from the geological, rock mechanical and topographical characterictics of one of Nagra's planned exploration areas. Final storage is effected in subterranean rock caverns accessed by horizontal tunnel. The reception area also is sited below the surface. Storage is conceived in such a way that, after closure of the repository, maintenance and supervision can be dispensed with and a guarantee of high long-term safety can nevertheless be provided. The envisaged repository consists of an entry tunnel for road vehicles and a reception area with a series of caverns for receiving waste, for additional technical facilities and for the production of the concrete back-fill material. The connecting tunnel is serviced by a tunnel railway and the actual repository area consists of several storage caverns. The repository is intended to accomodate a total of 200'000 m3 of solidified low- and intermediate-level waste. Valanginian marl is assumed as the host rock, although it would also be basically possible to house the proposed installations in other host rocks. The excavated material will total around 1'000'000 m3. The construction time for the whole installation is estimated as about 7 years and a working team of around 30 people will be required for the estimated 60-year operational duration. The project described in the present report justifies the conclusion that construction of a repository for low-and intermediate-level radioactive waste is feasible with present-day technology. This conclusion takes into consideration quantitative and operational constraints as well as geological and hydrogeological data relevant to constructional engineering. The latter are derived from a model data-set based on a specific locality

  1. NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

    Energy Technology Data Exchange (ETDEWEB)

    None

    1982-07-01

    This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules.

  2. NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

    International Nuclear Information System (INIS)

    1982-07-01

    This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules

  3. WIPP: construction and progress on a successful nuclear waste repository

    International Nuclear Information System (INIS)

    Cooper, W.R.; Sankey, C.A.

    1985-01-01

    The Department of Energy is constructing the Waste Isolation Pilot Plant (WIPP) in Southeastern New Mexico. The facility will retrievably store transuranic waste from defense activities of the United States and conduct experiments with Defense high-level waste which will be retrieved at the end of the experiments. This paper describes the progress and the present status of activities at WIPP. 4 refs

  4. The effect of microorganisms on asphaltopropylene concrete in a radioactive waste repository. Part 2

    International Nuclear Information System (INIS)

    Hlavackova, I.; Hlavacek, I.; Mara, M.; Wasserbauer, R.

    1993-11-01

    The permeability of asphaltopropylene concrete (APC) was examined after the action of aerobic bacteria and molds, and the changes in its volume, weight and swelling capacity were recorded. APC has been used as a sealing material in low level radioactive waste pits at the Dukovany NPP repository. Results of check-up sampling of microorganisms in the repository are evaluated. Sulphate reducing bacteria, which have been detected in soil near the reactor site, were isolated and their action upon asphaltopropylene (AP) was investigated. The resistance of bitumen layers containing model waste, against the action of aerobic bacteria and molds and against water was also examined. Bitumen samples containing model waste were found to absorb water at low temperatures considerably faster than unfilled bitumen. At elevated temperatures the absorption of water is appreciable, causing high weight losses of the bituminized waste layer due to degradation. The time dependences of the bitumen sample weight at 20 degC and 60 degC in distilled and cement water are given in the Appendix. The results included in the final reports ''Investigation of the effect of microorganisms on asphaltopropylene-based insulating materials employed as sealing in the secondary radioactive waste repository at the Dukovany NPP in relation to the microbial flora present. Bacteria'' and ''Investigation of the impact of biodegradation effects of aerobic and anaerobic microorganisms including molds on asphalt and asphaltopropylene in conditions of the ground repository at the Dukovany NPP'' are also given. (J.B.). 8 tabs., 33 figs

  5. Repository thermal response: A preliminary evaluation of the effects of modeled waste stream resolution

    International Nuclear Information System (INIS)

    Ryder, E.E.; Dunn, E.

    1995-09-01

    One of the primary factors that influences our predictions of host-rock thermal response within a high level waste repository is how the waste stream's represented in the models. In the context of thermal modeling, waste stream refers to an itemized listing of the type (pressurized-water or boiling-water reactor), age, burnup, and enrichment of the spent nuclear fuel assemblies entering the repository over the 25-year emplacement phase. The effect of package-by-package variations in spent fuel characteristics on predicted repository thermal response is the focus of this report. A three-year portion of the emplacement period was modeled using three approaches to waste stream resolution. The first assumes that each package type emplaced in a given year is adequately represented by average characteristics. For comparison, two models that explicitly account for each waste package's individual characteristics were run; the first assuming a random selection of packages and the second an ordered approach aimed at locating the higher power output packages toward the center of the emplacement area. Results indicate that the explicit representation of packages results in hot and cold spots that could have performance assessment and design implications. Furthermore, questions are raised regarding the representativeness of average characteristics with respect to integrated energy output and the possible implications of a mass-based repository loading approach

  6. Geological disposal of high-level radioactive waste. Conceptual repository design in hard rock

    International Nuclear Information System (INIS)

    Beale, H.; Griffin, J.R.; Davies, J.W.; Burton, W.R.

    1980-01-01

    The paper gives an interim report on UK studies on possible designs for a repository for vitrified high-level radioactive waste in crystalline rock. The properties of the waste are described and general technical considerations of consequences of disposal in the rock. As an illustration, two basic designs are described associated with pre-cooling in an intermediate store. Firstly, a 'wet repository' is outlined wherein canisters are sealed up closely in boreholes in the rock in regions of low groundwater movement. Secondly, a 'dry repository' above sea level is described where emp