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Sample records for swedish deep repository

  1. Siting of the Swedish deep geological repository - experiences and plans

    International Nuclear Information System (INIS)

    Eng, T.; Backblom, G.; Thegerstrom, C.; Ahlbom, K.; Leijon, B.

    1996-01-01

    The paper provides a brief overview of the Swedish siting programme for a deep repository. A stepwise process is a key element in the planning and implementation of deep disposal of long-lived waste in Sweden. The local siting work is made in cooperation with the affected and concerned municipalities. The programs, decisions and results that so far have been reported and ongoing feasibility studies is a solid platform for the continuing siting work. It can be noted that the siting work in some cases has caused heavy opposition and negative opinions. Careful considerations on how to proceed to develop the necessary background material must therefore be made. The Environmental Impact Assessment (EIA) process that has started in conjunction with feasibility studies are judged to play an important role in the future. In this process, with extensive local involvement, critical issues can be detected at an early stage and sound ideas on both the process itself and on technical issues can be incorporated. To facilitate information exchange and cooperation between the municipalities involved and to coordinate liaison between the municipalities and county administrative boards affected by the studies, the Swedish government has appointed a National Coordinator for nuclear waste disposal. The government also has decided to provide the concerned municipalities with funding for their participation in the process. (author)

  2. Siting factors for the Swedish deep repository for spent fuel

    International Nuclear Information System (INIS)

    Stroem, A.; Ericsson, Lars O.; Svemar, C.; Almen, K.E.; Andersson, Johan

    1998-01-01

    A project entitled Siting factors and criteria for site evaluation was initiated at the SKB in 1997. The project comprises an important part of the work of siting and site selection that is being pursued within SKB. The purpose of the project is to create a logical structure for the continued siting work, and its results should also be able to be used to assist in evaluating sites. The project will thereby also provide a means - in accordance with the Government's decision regarding Research Programme 95 - to obtain more detailed and quantified siting factors and criteria than those previously presented in the supplement to Research Programme 92. The overall goals of the project are to identify and quantify requirements and preferences regarding the properties of the rock and the soil from the perspectives of long-term safety, performance and planning and design of the rock works, and to identify siting factors and criteria. The latter should be able to be used to determine whether requirements and preferences are satisfied, both when screening sites for site investigation and after completed site investigation. Presented requirements, preferences, factors and criteria must be acceptable to national and municipal authorities or others with influence over the siting work. To start with, requirements and preferences regarding the performance of the rock in a deep repository have been clarified. These requirements and preferences are based on many years of experience of safety assessments and construction analyses within SKB. What is new here is the structuring that has been done, where a classification is made into different geoscientific disciplines, and the formalism that has been developed for the concepts requirements, preferences and performance. This is a prerequisite for a consistent and hopefully comprehensive set of requirements from a functional perspective. Work has continued on siting factors with reference to a coming site investigation programme. A

  3. Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Almen, Karl-Erik

    2004-03-01

    Monitoring in this report is defined as 'Continuous or repeated observations or measurements of parameters to increase the scientific understanding of the site and the repository, to show compliance with requirements or for adaptation of plans in light of the monitoring results.' The international outlook from IAEA, OECD/NEA, CEC and some country-specific reviews presented in the report forms a necessary background to the Swedish monitoring framework. The implementation of the deep repository in Sweden is executed in phases where monitoring is an inherently integrated activity in the programme. The first phase is the site investigations when Primary Baseline conditions are established. During the following construction phase of the repository, detailed site characterisation continues in conjunction with construction of the access to the deposition area, construction of parts of the deposition area and the central service area. Monitoring is then used to track the changes to the previously established Primary Baseline conditions and distinguishing these imposed changes from natural variations or from other man-made influences. During the initial operation phase, around 200-400 canisters of spent fuel is emplaced and deposition tunnels backfilled. After up-dated evaluations, the phase of regular operation begin, where detailed characterisation, construction of the repository and waste emplacement are concurrent activities. The closure of the repository will take place when all spent fuel has been emplaced, i.e. in the latter part of this century. Monitoring during the stepwise implementation of the repository is executed of several reasons mainly to: describe the Primary Baseline conditions of the repository site, develop and demonstrate understanding of the repository site and the behaviour of engineered barriers, assist in the decision-making process, show compliance with international and national guidelines and regulations. Specific rationales for monitoring are

  4. Monitoring during the stepwise implementation of the Swedish deep repository for spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, Goeran [Conrox (Sweden); Almen, Karl-Erik [KEA Geokonsult AB (Sweden)

    2004-03-01

    Monitoring in this report is defined as 'Continuous or repeated observations or measurements of parameters to increase the scientific understanding of the site and the repository, to show compliance with requirements or for adaptation of plans in light of the monitoring results.' The international outlook from IAEA, OECD/NEA, CEC and some country-specific reviews presented in the report forms a necessary background to the Swedish monitoring framework. The implementation of the deep repository in Sweden is executed in phases where monitoring is an inherently integrated activity in the programme. The first phase is the site investigations when Primary Baseline conditions are established. During the following construction phase of the repository, detailed site characterisation continues in conjunction with construction of the access to the deposition area, construction of parts of the deposition area and the central service area. Monitoring is then used to track the changes to the previously established Primary Baseline conditions and distinguishing these imposed changes from natural variations or from other man-made influences. During the initial operation phase, around 200-400 canisters of spent fuel is emplaced and deposition tunnels backfilled. After up-dated evaluations, the phase of regular operation begin, where detailed characterisation, construction of the repository and waste emplacement are concurrent activities. The closure of the repository will take place when all spent fuel has been emplaced, i.e. in the latter part of this century. Monitoring during the stepwise implementation of the repository is executed of several reasons mainly to: describe the Primary Baseline conditions of the repository site, develop and demonstrate understanding of the repository site and the behaviour of engineered barriers, assist in the decision-making process, show compliance with international and national guidelines and regulations. Specific rationales for

  5. Swedish deep repository siting programme. Guide to the documentation of 25 years of geoscientific research (1976-2000)

    Energy Technology Data Exchange (ETDEWEB)

    Milnes, Alan Geoffrey [GEA Consulting, Uppsala (Sweden)

    2002-03-01

    Since the mid-1970s, the Swedish Nuclear Fuel and Waste Management Company (SKB) has been carrying out geoscientific research and feasibility studies aimed at identifying suitable sites for deep repositories in the Precambrian basement of the Baltic Shield. The documentation of this research effort forms an extensive body of material which is exceptionally wide-ranging and which is generally little known outside the Swedish nuclear waste community. This has now been compiled in the form of a 'documentation guide' in order to make the research results more easily accessible to the scientific community at large, and to show how they relate to their 'nearest surroundings', i.e. the relevant academic scientific literature and the documentation of similar research by other institutions, in Sweden and in other countries (Finland, Canada). The documentation covers the period 1976-2000 and contains ca. 850 citations, of which about half are technical reports published by SKB and its forerunners. In the main body of the guide (Chapters 2-9), the material is arranged thematically and the scope of the documentation in each theme is described and commented in short texts, showing the interrelationships between the individual reports and scientific papers, with appropriate cross-references. Early chapters (2-5, and 7) cover general themes: bedrock geology, fracturing, glaciation and crustal dynamics, deep groundwater, and geosphere transport, each subdivided into citation groups under headings which are of particular interest to the Swedish deep repository siting programme. Later chapters (6, and 8-9) include thumbnail sketches of the Swedish study sites (Finnsjoen, Fjaellveden, Gideaa, Kamlunge, Klipperaas, Sternoe), the underground laboratory sites of Stripa and Aespoe, and comparable sites in Finland and Canada, as well as the complete documentation to the feasibility studies carried out in eight Swedish municipalities between 1993 and 2000 (Storuman

  6. Swedish deep repository siting programme. Guide to the documentation of 25 years of geoscientific research (1976-2000)

    International Nuclear Information System (INIS)

    Milnes, Alan Geoffrey

    2002-03-01

    Since the mid-1970s, the Swedish Nuclear Fuel and Waste Management Company (SKB) has been carrying out geoscientific research and feasibility studies aimed at identifying suitable sites for deep repositories in the Precambrian basement of the Baltic Shield. The documentation of this research effort forms an extensive body of material which is exceptionally wide-ranging and which is generally little known outside the Swedish nuclear waste community. This has now been compiled in the form of a 'documentation guide' in order to make the research results more easily accessible to the scientific community at large, and to show how they relate to their 'nearest surroundings', i.e. the relevant academic scientific literature and the documentation of similar research by other institutions, in Sweden and in other countries (Finland, Canada). The documentation covers the period 1976-2000 and contains ca. 850 citations, of which about half are technical reports published by SKB and its forerunners. In the main body of the guide (Chapters 2-9), the material is arranged thematically and the scope of the documentation in each theme is described and commented in short texts, showing the interrelationships between the individual reports and scientific papers, with appropriate cross-references. Early chapters (2-5, and 7) cover general themes: bedrock geology, fracturing, glaciation and crustal dynamics, deep groundwater, and geosphere transport, each subdivided into citation groups under headings which are of particular interest to the Swedish deep repository siting programme. Later chapters (6, and 8-9) include thumbnail sketches of the Swedish study sites (Finnsjoen, Fjaellveden, Gideaa, Kamlunge, Klipperaas, Sternoe), the underground laboratory sites of Stripa and Aespoe, and comparable sites in Finland and Canada, as well as the complete documentation to the feasibility studies carried out in eight Swedish municipalities between 1993 and 2000 (Storuman, Malaa, Nykoeping

  7. The Swedish approach to siting of a deep geological repository and interaction with the public

    International Nuclear Information System (INIS)

    Thegerstroem, C.

    1993-01-01

    The planned process for siting of a deep geological repository for encapsulated spent nuclear fuel in Sweden was presented in the 1992 SKB R and D programme. A first phase of the repository operation will be limited to disposal of a small amount of encapsulated spent nuclear fuel (approximately 800 tons). This phase will be followed by an evaluation of experiences as well as alternative options before deciding if, when and how to proceed with disposal of the remaining amounts of spent fuel. During the first phase it will be possible to retrieve the waste. Siting is planned to be done in stages. The field studies and safety assessments performed strongly indicate that it is possible to find geological suitable sites within many regions of Sweden. The potential for fulfilling safety requirements will be a crucial factor in site-selection. Local interest in, and attitude to a repository siting will play an important role in the siting process. It is important that an atmosphere of trust and openness can be established. Extensive geological site characterization work will be carried out at the sites selected and studies of other technical, social, economical or political matters will be equally important. Public communication and local participation will form an essential part of the siting programme from the outset. 3 refs., 3 figs

  8. Choice of rock excavation methods for the Swedish deep repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, Goeran [Conrox, Stockholm (Sweden); Christiansson, Rolf [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Lagerstedt, Leif [SwedPower AB, Stockholm (Sweden)

    2004-09-01

    Choice of rock excavation methods will or may have implications for a number of issues like repository layout, long term and operational safety, environmental impact, design of and operation of transport vehicles and methodology for backfilling the repository before closure as well as effects on costs and schedules. To fully analyse the issues at hand related to selection of excavation methods, SKB organized a project with the objectives: To investigate and compare principal technical solutions for rock excavation, both methods that are used at present but also methods that may be feasible 10 years from now; To assess how the selection of excavation method influences the design and operation of the deep repository; To present a definition of the Excavation Damaged/Disturbed Zone and practical methods for measurements of EDZ; To present advantages and disadvantages with different excavation methods for the various tunnels and underground openings as a basis for selection of preferred excavation methods; To present the Design Justification Statement for the selection of particular excavation methods for the different tunnels and openings in the deep repository to underpin a decision on excavation method; and To present background data that may be required for the evaluation of the long term safety of the deep repository. Main alternatives studied are very smooth blasting, excavation with a tunnel-boring machine (TBM) and excavation with horizontal pull-reaming using more or less conventional raise-boring equipment. The detailed studies were carried through in co-operation with major suppliers and end-users of the technology. An observation in this study is that all excavation technologies are mature; no major breakthroughs are foreseen within a 10 year period but it is likely that for any technology selected, SKB would specifically fine-tune the design of the equipment and work procedures in view of requirements and site specific conditions. Excavation methods have

  9. Choice of rock excavation methods for the Swedish deep repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Christiansson, Rolf; Lagerstedt, Leif

    2004-09-01

    Choice of rock excavation methods will or may have implications for a number of issues like repository layout, long term and operational safety, environmental impact, design of and operation of transport vehicles and methodology for backfilling the repository before closure as well as effects on costs and schedules. To fully analyse the issues at hand related to selection of excavation methods, SKB organized a project with the objectives: To investigate and compare principal technical solutions for rock excavation, both methods that are used at present but also methods that may be feasible 10 years from now; To assess how the selection of excavation method influences the design and operation of the deep repository; To present a definition of the Excavation Damaged/Disturbed Zone and practical methods for measurements of EDZ; To present advantages and disadvantages with different excavation methods for the various tunnels and underground openings as a basis for selection of preferred excavation methods; To present the Design Justification Statement for the selection of particular excavation methods for the different tunnels and openings in the deep repository to underpin a decision on excavation method; and To present background data that may be required for the evaluation of the long term safety of the deep repository. Main alternatives studied are very smooth blasting, excavation with a tunnel-boring machine (TBM) and excavation with horizontal pull-reaming using more or less conventional raise-boring equipment. The detailed studies were carried through in co-operation with major suppliers and end-users of the technology. An observation in this study is that all excavation technologies are mature; no major breakthroughs are foreseen within a 10 year period but it is likely that for any technology selected, SKB would specifically fine-tune the design of the equipment and work procedures in view of requirements and site specific conditions. Excavation methods have

  10. Deep ground water microbiology in Swedish granite rock and it's relevance for radio-nuclide migration from a Swedish high level nuclear waste repository

    International Nuclear Information System (INIS)

    Pedersen, Karsten

    1989-03-01

    Data on numbers, species and activity of deep ground water microbial populations in Swedish granite rock have been collected. Specific studies are performed on radio-nuclid uptake on bacteria judge to be probable inhabitants in Swedish nuclear waste repositories. An integrated mobile field laboratory was used for water sampling and for the immediate counting and inoculation of the samples from boreholes at levels between 129 and 860 m. A sampler adapted for the collection of undisturbed samples for gas analysis was used to collect samples for bacterial enumerations and enrichments. The sampler can be opened and closed from the surface at the actual sampling depth. The samples can subsequently be brought to the surface without contact with air and with the pressure at the actual sampling depth. The number of bacteria were determined in samples from the gas sampler when this was possible. Else numbers are determined in the water that is pumped up to the field lab. The average total number of bacteria is 3 x 10 5 bacterial ml -1 . The number of bacteria possible to recover with plate count arrays from 0.10 to 21.9%. (author)

  11. Fundamental aspects of stress corrosion cracking of copper relevant to the Swedish deep geologic repository concept

    International Nuclear Information System (INIS)

    Bhaskaran, Ganesh; Carcea, Anatolie; Ulaganathan, Jagan; Wang, Shengchun; Huang, Yin; Newman, Roger C.

    2013-03-01

    Phosphorus-doped oxygen-free copper will be used as the outer barrier in canisters that will contain spent nuclear fuel in the proposed Swedish underground repository. The possibility of stress corrosion cracking (SCC) is a concern, in view of isolated reports of cracking or intergranular corrosion of pure copper in sulfide solutions. This concern was addressed in the present work using copper tensile specimens provided by SKB. Methods included slow strain rate testing, constant strain tensile testing, electrochemical and surface analytical studies of corrosion products, and electron backscatter diffraction analysis of grain orientation effects on corrosion. The base solutions were prepared from NaCl or synthetic sea water with addition of varying amounts of sodium sulfide at room temperature and 80 degree Celsius. No SCC was found in any of the testing, for a range of sulfide concentrations from 5-50 mM at room temperature or 8 C, including tests where small anodic or cathodic potential displacements were applied from the open-circuit (corrosion) potential. Neither was SCC found in constant-strain immersion testing with very large strain. The Cu2S corrosion product is generally very coarse, fragile, and easily spalled off in severe corrosion environments, i.e. high sulfide concentration, high temperature, less perfect de aeration, etc. But it could also consist of very fine grains, relatively compact and adherent, on particular grain orientations when it was formed on an electro polished surface in a very well-deaerated solution. These orientations have not yet been identified statistically, although some preference for thin, adherent films was noted on orientations close to (100). The notion that the corrosion reaction is always controlled by inward aqueous-phase diffusion of sulfide may thus not be unconditionally correct for this range of sulfide concentrations; however it is hard to distinguish the role of diffusion within pores in the film. In the actual

  12. Fundamental aspects of stress corrosion cracking of copper relevant to the Swedish deep geologic repository concept

    Energy Technology Data Exchange (ETDEWEB)

    Bhaskaran, Ganesh; Carcea, Anatolie; Ulaganathan, Jagan; Wang, Shengchun; Huang, Yin; Newman, Roger C. [Dept. of Chemical Engineering and Applied Chemistry, Univ. of Toronto, Toronto (Canada)

    2013-03-15

    Phosphorus-doped oxygen-free copper will be used as the outer barrier in canisters that will contain spent nuclear fuel in the proposed Swedish underground repository. The possibility of stress corrosion cracking (SCC) is a concern, in view of isolated reports of cracking or intergranular corrosion of pure copper in sulfide solutions. This concern was addressed in the present work using copper tensile specimens provided by SKB. Methods included slow strain rate testing, constant strain tensile testing, electrochemical and surface analytical studies of corrosion products, and electron backscatter diffraction analysis of grain orientation effects on corrosion. The base solutions were prepared from NaCl or synthetic sea water with addition of varying amounts of sodium sulfide at room temperature and 80 degree Celsius. No SCC was found in any of the testing, for a range of sulfide concentrations from 5-50 mM at room temperature or 8 C, including tests where small anodic or cathodic potential displacements were applied from the open-circuit (corrosion) potential. Neither was SCC found in constant-strain immersion testing with very large strain. The Cu2S corrosion product is generally very coarse, fragile, and easily spalled off in severe corrosion environments, i.e. high sulfide concentration, high temperature, less perfect de aeration, etc. But it could also consist of very fine grains, relatively compact and adherent, on particular grain orientations when it was formed on an electro polished surface in a very well-deaerated solution. These orientations have not yet been identified statistically, although some preference for thin, adherent films was noted on orientations close to (100). The notion that the corrosion reaction is always controlled by inward aqueous-phase diffusion of sulfide may thus not be unconditionally correct for this range of sulfide concentrations; however it is hard to distinguish the role of diffusion within pores in the film. In the actual

  13. SKI SITE-94, deep repository performance assessment project, summary

    International Nuclear Information System (INIS)

    1999-01-01

    SITE-94 is a comprehensive performance assessment exercise for a hypothetical repository for spent nuclear fuel at a real site in Sweden. SITE-94 was carried out to develop the capability and tools to enable Swedish Nuclear Power Inspectorate (SKI) to review fully the proposals for a deep repository which are expected to be made by the Swedish Nuclear Fuel and Waste Management Company, SKB (the implementor). Sweden is one of the leading countries in the research and development of geological disposal of radioactive waste. The developed methodology for performance assessment has attracted interests from other countries. The Summary of the main report of the SITE-94 project is translated here into Japanese to allow to make the information on the methodology and the related issues available among Japanese concerned. (author)

  14. Towards a Swedish repository for spent fuel

    International Nuclear Information System (INIS)

    Ahlstroem, P.-E.

    1997-01-01

    Nuclear power is producing electricity for the benefit of society but is also leaving radioactive residues behind. It is our responsibility to handle these residues in a safe and proper manner. The development of a system for handling spent fuel from nuclear power plants has proceeded in steps. The same is true for the actual construction of facilities and will continue to be the case for the final repository for spent fuel and other types of long-lived wastes. The primary objective in constructing the repository will be to isolate and contain the radioactive waste. In case the isolation fails for some reason the multibarrier system should retain and retard the radionuclides that might come into contact with the groundwater. A repository is now planned to be built in two steps where the first step will include deposition of about 400 canisters with spent fuel. This first step should be finished in about 20 years from now and be followed by an extensive evaluation of the results from not only this particular step but also from the development of alternative routes before deciding on how to proceed. A special facility to encapsulate the spent fuel is also required. Such an encapsulation plant is proposed to be constructed as an extension of the existing interim storage CLAB. Finding a site for the repository is a critical issue in the implementation of any repository. The siting process started a few years ago and made some progress but is by no means yet completed. It will go on at least into the early part of the next decade. When the present nuclear power plants begin to be due for retirement there should also be some facilities in place to take permanent care of the long-lived radioactive residues. Progress in siting will be a prerequisite for success in our responsibility to make progress towards a safe permanent solution of the waste issue. (orig.)

  15. Diversion path analysis for the Swedish geological repository

    International Nuclear Information System (INIS)

    Fritzell, Anni; Meer, Klaas Van Der

    2008-02-01

    The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

  16. Diversion path analysis for the Swedish geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Fritzell, Anni (Dept. of Physics and Astronomy, Uppsala Univ., Uppsala (Sweden)); Meer, Klaas Van Der (Belgian Nuclear Research Center SCK.CEN (BG))

    2008-02-15

    The Swedish strategy to handle the spent fuel from the nuclear power plants is direct disposal in a geological repository. The safeguards regime covering all nuclear material in the state will be expanded to cover the new repository, which will require a novel safeguards approach due mainly to the inaccessibility of the fuel after disposal. The safeguards approach must be able to provide a high level of assurance that the fuel in the repository not diverted, but must also be resource efficient. An attractive approach with regards to use of resources is to monitor only the access points to the repository, i.e. the openings. The implementation of such an approach can only be allowed if it is shown to be sufficiently secure. With the purpose of determining the applicability of this 'black box' approach, a diversion path analysis for the Swedish geological repository has been carried out. The result from the analysis shows that all credible diversion paths could be covered by the black-box safeguards approach provided that the identified boundary conditions can be met

  17. Current Status of Deep Geological Repository Development

    International Nuclear Information System (INIS)

    Budnitz, R J

    2005-01-01

    This talk provided an overview of the current status of deep-geological-repository development worldwide. Its principal observation is that a broad consensus exists internationally that deep-geological disposal is the only long-term solution for disposition of highly radioactive nuclear waste. Also, it is now clear that the institutional and political aspects are as important as the technical aspects in achieving overall progress. Different nations have taken different approaches to overall management of their highly radioactive wastes. Some have begun active programs to develop a deep repository for permanent disposal: the most active such programs are in the United States, Sweden, and Finland. Other countries (including France and Russia) are still deciding on whether to proceed quickly to develop such a repository, while still others (including the UK, China, Japan) have affirmatively decided to delay repository development for a long time, typically for a generation of two. In recent years, a major conclusion has been reached around the world that there is very high confidence that deep repositories can be built, operated, and closed safely and can meet whatever safety requirements are imposed by the regulatory agencies. This confidence, which has emerged in the last few years, is based on extensive work around the world in understanding how repositories behave, including both the engineering aspects and the natural-setting aspects, and how they interact together. The construction of repositories is now understood to be technically feasible, and no major barriers have been identified that would stand in the way of a successful project. Another major conclusion around the world is that the overall cost of a deep repository is not as high as some had predicted or feared. While the actual cost will not be known in detail until the costs are incurred, the general consensus is that the total life-cycle cost will not exceed a few percent of the value of the

  18. 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)

  19. Repository and deep borehole disposition of plutonium

    International Nuclear Information System (INIS)

    Halsey, W.G.

    1996-02-01

    Control and disposition of excess weapons plutonium is a growing issue as both the US and Russia retire a large number of nuclear weapons> A variety of options are under consideration to ultimately dispose of this material. Permanent disposition includes tow broad categories: direct Pu disposal where the material is considered waste and disposed of, and Pu utilization, where the potential energy content of the material is exploited via fissioning. The primary alternative to a high-level radioactive waste repository for the ultimate disposal of plutonium is development of a custom geologic facility. A variety of geologic facility types have been considered, but the concept currently being assessed is the deep borehole

  20. Site investigation requirements for a deep repository

    International Nuclear Information System (INIS)

    Farmer, I.W.

    1992-03-01

    Techniques currently available for measuring geotechnical parameters needed in the design, construction and assessment of a deep underground repository have been critically examined. These techniques have been considered under four main areas: definition of the rock discontinuity structure, definition of the in-situ stress distribution in the rock mass, estimation of the geomechanical characteristics of the rock mass, and estimation of flow and transport characteristics of the rock mass. The review concludes that generally rocks and rock masses are not well characterised by tests from cores or from boreholes and gives reason to support this view. The only parameters which can be measured accurately are laboratory index properties which are useful only in a comparative assessment of different rock types. Finally the review concludes that the only way to obtain useful data on rock behaviour is through large pilot scale tests with appropriate and controlled boundary conditions conducted preferably in the potential host strata. (author)

  1. Radiological risks due to intrusion into a deep bedrock repository

    International Nuclear Information System (INIS)

    Nordlinder, S.; Bergstroem, U.; Edlund, O.

    1999-01-01

    The Swedish concept for disposal of high-level waste is a deep (500 m) bedrock repository (SFL) protected by multiple barriers that isolate the waste from the environment for such a long time that the physical decay will cause a substantial reduction of the radioactivity. The aim of concentration and isolation of high-level waste is to reduce the radiation risk. Intrusion in the repository may introduce a small residual risk to individuals. A risk analysis was performed comprising dose assessment and probabilities of occurrence. Intrusions may be considered to take place either due to conscious actions or by actions without any knowledge about the repository. For conscious intrusion it may be assumed that there will be enough knowledge to manage the radiation situation in a professional manner. Several reasons for making inadvertent intrusion are possible. Independently of the purpose, the most probable initial way of coming into contact with the radioactive material is by deep drilling. Examples of causes for drilling could be general scientific purposes or exploitation of geothermal energy. Dose assessments were made for intrusion due to inclined drilling directly into a canister, and drilling near an initially malfunctioning canister from which radionuclides have leaked into the groundwater. For the former case, external pathways were considered due to exposure from a core of the canister with fuel and contaminated bore dust. The most common drilling method is with water flushing for removal of bore dust, which will not cause any substantial transfer of radionuclides to air. For the second case, it was assumed that there was a well in the vicinity. The only pathway considered was therefore consumption of water because it dominates the exposure. The highest dose rates to man were, as expected, obtained by drilling into the canister. Dose rates decrease with time after closure. During the first time the relatively short-lived radionuclides Cs-137 and Sr-90 give

  2. Repository tunnel construction in deep clay formations

    International Nuclear Information System (INIS)

    Clarke, B.G.; Mair, R.J.; Taylor, R.N.

    1992-01-01

    One of the objects of the Hades project at Mol, Belgium has been to evaluate the feasibility of construction of a deep repository in the Boom clay formation at depth of approximately 225 metres. The main objective of the present project was to analyse and interpret the detailed geotechnical measurements made around the Hades trial shaft and tunnel excavations and evaluate the safety of radioactive waste disposal in a repository facility in deep clay formations. Plasticity calculations and finite element analyses were used which gave results consistent with the in-situ measurements. It was shown that effective stress analysis could successfully predict the observed field behaviour. Correct modelling of the small-strain stiffness of the Boom clay was essential if reasonable predictions of the pore pressure response due to construction are to be made. The calculations undertaken indicated that, even in the long term, the pressures on the test drift tunnel lining are likely to be significantly lower than the overburden pressure. Larger long-term tunnel lining pressures are predicted for impermeable linings. A series of laboratory stress path tests was undertaken to determine the strength and stiffness characteristics of the Boom clay. The tests were conducted at appropriate effective stress levels on high-quality samples retrieved during construction of the test drift. The apparatus developed for the testing is described and the results discussed. The development of a self boring retracting pressure-meter is described. This novel in-situ testing device was specifically designed to determine from direct measurements the convergence/confinement curve relevant to tunnelling in clay formations. 44 refs., 60 figs., 3 tabs

  3. Encyclopaedia of Features, Events and Processes (FEPs) for the Swedish SFR and Spent Fuel Repositories. Preliminary Version

    International Nuclear Information System (INIS)

    Miller, Bill; Savage, Dave; McEwen, Tim; White, Matt

    2002-08-01

    dealing with all the FEPs that could occur and which might influence repository safety. A commonly adopted procedure is known as the 'Sandia Methodology' which, in simple terms, involves defining all potential FEPs that may affect the performance of the disposal system, classifying and screening them for relevance, and then combining them into scenarios by means of identifying related groups of FEPs. In 1988, both SKI and SKB embarked on a joint exercise to try to achieve consensus on the principles for scenario selection for a Swedish repository for spent fuel. This joint exercise was built on the Sandia Methodology and began by constructing a list of FEPs considered relevant to a deep spent fuel repository in granitic rocks in Sweden. One of the outcomes of the joint SKB/SKI exercise, was the development of the 'Process System' which is an ordered assembly of those FEPs which might have to be considered, at some level of detail, in PA calculations in all scenarios. In 1994, SKI developed further the Sandia Methodology in the SITE-94 PA and introduced the concept of the 'Process Influence Diagram (PID)' which is a graphical representation of the many FEPs considered relevant to the disposal system together with the potential influences that may occur between them. The use of a PID was found to be a constructive and informative approach to thinking about the evolution of the repository. In particular, it forces consideration of how the action of one FEP may affect the behaviour of the overall disposal system, and specific components of it, through its influence on other FEPs. However, evaluation of these influences requires that the definition and scope of each individual FEP is commonly agreed. There was, therefore, a requirement for definitions to be written for each FEP. This was the original impetus for writing this encyclopaedia.

  4. Encyclopaedia of Features, Events and Processes (FEPs) for the Swedish SFR and Spent Fuel Repositories. Preliminary Version

    Energy Technology Data Exchange (ETDEWEB)

    Miller, Bill; Savage, Dave; McEwen, Tim; White, Matt [QuantiSci Ltd, Melton Mowbray (United Kingdom)

    2002-08-01

    approach to dealing with all the FEPs that could occur and which might influence repository safety. A commonly adopted procedure is known as the 'Sandia Methodology' which, in simple terms, involves defining all potential FEPs that may affect the performance of the disposal system, classifying and screening them for relevance, and then combining them into scenarios by means of identifying related groups of FEPs. In 1988, both SKI and SKB embarked on a joint exercise to try to achieve consensus on the principles for scenario selection for a Swedish repository for spent fuel. This joint exercise was built on the Sandia Methodology and began by constructing a list of FEPs considered relevant to a deep spent fuel repository in granitic rocks in Sweden. One of the outcomes of the joint SKB/SKI exercise, was the development of the 'Process System' which is an ordered assembly of those FEPs which might have to be considered, at some level of detail, in PA calculations in all scenarios. In 1994, SKI developed further the Sandia Methodology in the SITE-94 PA and introduced the concept of the 'Process Influence Diagram (PID)' which is a graphical representation of the many FEPs considered relevant to the disposal system together with the potential influences that may occur between them. The use of a PID was found to be a constructive and informative approach to thinking about the evolution of the repository. In particular, it forces consideration of how the action of one FEP may affect the behaviour of the overall disposal system, and specific components of it, through its influence on other FEPs. However, evaluation of these influences requires that the definition and scope of each individual FEP is commonly agreed. There was, therefore, a requirement for definitions to be written for each FEP. This was the original impetus for writing this encyclopaedia.

  5. Earthquakes - a danger to deep-lying repositories?

    International Nuclear Information System (INIS)

    2012-03-01

    This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at geological factors concerning earthquakes and the safety of deep-lying repositories for nuclear waste. The geological processes involved in the occurrence of earthquakes are briefly looked at and the definitions for magnitude and intensity of earthquakes are discussed. Examples of damage caused by earthquakes are given. The earthquake situation in Switzerland is looked at and the effects of earthquakes on sub-surface structures and deep-lying repositories are discussed. Finally, the ideas proposed for deep-lying geological repositories for nuclear wastes are discussed

  6. SKI SITE-94. Deep Repository Performance Assessment Project. Summary

    International Nuclear Information System (INIS)

    1997-02-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry's R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is neither a safety assessment nor a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The main report (SKI-R--96-36) gives a detailed description of the many inter-related studies undertaken as part of the research project, while the present report presents a condensed summary of the main report. 46 refs

  7. SR 97: Post-closure safety for a KBS 3 type deep repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Hedin, A.; Kautsky, U.

    2000-03-01

    Prior to coming site investigations for siting of a deep repository for spent nuclear fuel, SKB has carried out the long-term safety assessment SR 97, requested by the Swedish Government. The repository is of the KBS-3 type, where the fuel is placed in isolating copper canisters with a high-strength cast iron insert. The canisters are surrounded by bentonite clay in individual deposition holes at a depth of 500 m in granitic bedrock. The future evolution of the repository system is analysed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings, including climate, persist. The four other scenarios show the evolution if the repository contains a few initially defective canisters, in the event of climate change, in the event of earthquakes, and in the event of future inadvertent human intrusion. The principal conclusion of the assessment is that the prospects of building a safe deep repository for spent nuclear fuel in Swedish granitic bedrock are very good. (author)

  8. Geohydrological simulation of a deep coastal repository

    International Nuclear Information System (INIS)

    Follin, S.

    1995-12-01

    This conceptual-numerical study treats the dewatering and resaturation phases associated with the construction, use and closure of a coastal nuclear waste repository located at depth in sparsely fractured Baltic Shield rocks. The main objective is to simulate the extent and duration of saline intrusion for a reasonable set of geohydrological assumptions. Long-term changes in the chemical environment associated with saline intrusion may affect the properties of the buffer zone material (bentonite). The first part of the study deals with history matching of a simple model geometry and the second part treats the dewatering and resaturation phases of the simulated repository. The history matching supports the standpoint that the occurrence of saline ground water reflects an ongoing but incomplete Holocene flushing of the Baltic Shield. The drawdown after fifty years of dewatering is highly dependent on the permeability of the excavated damaged zone. If the permeability close the repository is unaltered the entire region between the top side of the model and the repository is more or less partially saturated at the end of the simulation period. The simulations of a fifty year long recovery period suggest that the distribution between fresh and saline ground waters may be quite close to the conditions prior to the dewatering phase already after fifty years of closure despite an incomplete pressure recovery, which is an interesting result considering the objective of the study. 12 refs

  9. Deep geological repository: Starting communication at potentially suitable sites

    International Nuclear Information System (INIS)

    Sumberova, Vera

    2001-01-01

    The siting of a deep geological repository in the Czech Republic is and will be a complicated process, since it is the first siting process of a nuclear facility designed from the start to be located at non-nuclear sites and to be organised under democratic conditions. This presentation describes the concept of radioactive waste and spent nuclear management in the Czech Republic, Communication activities of Radioactive Waste Repository Authority (RAWRA) with local representatives and lessons learned

  10. 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)

  11. The undersea location of the Swedish Final Repository for reactor waste, SFR - human intrusion aspects

    International Nuclear Information System (INIS)

    Eng, T.

    1989-01-01

    The Swedish Final Repository for reactor waste, SFR, is built under the Baltic sea close to the Forsmark nuclear power plant. Sixty metres of rock cover the repository caverns under the seabed. The depth of the Baltic sea is about 5-6 m at this location. A human intrusion scenario that in normal inland locations has shown to be of great importance, is a well that is drilled through or in the close vicinity of the repository. Since the land uplift in the SFR area is about 6 mm/year the undersea location of SFR ensures that no well will be drilled at this location for a considerable time while the area is covered by the Baltic sea

  12. Copper corrosion under expected conditions in a deep geologic repository

    Energy Technology Data Exchange (ETDEWEB)

    King, F. [Integrity Corrosion Consulting Ltd, Calgary, Alberta (Canada); Ahonen, L. [Geological Survey of Finland, Espoo (Finland); Taxen, C. [Swedish Corrosion Inst., Stockholm (Sweden); Vuorinen, U. [VTT Chemical Technology, Espoo (Finland); Werme, L. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2001-12-01

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 20 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear disposal repository located in he Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long- term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature.Various areas are considered: the expected evolution of the geochemical conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion before and during saturation of the compacted bentonite buffer by groundwater, general and localized corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. Much has been learnt about the long-term corrosion behaviour of copper canisters over the past 20 years. The majority of the information reviewed here is drawn from the Swedish/Finnish and Canadian programmes. Despite differences in scientific approach, and canister and repository design, the results of these two programmes both suggest that copper provides an excellent corrosion barrier in an underground repository. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid.

  13. Copper corrosion under expected conditions in a deep geologic repository

    Energy Technology Data Exchange (ETDEWEB)

    King, F.; Ahonen, L.; Taxen, C.; Vuorinen, U.; Werme, L

    2002-01-01

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 20 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear disposal repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion before and during saturation of the compacted bentonite buffer by groundwater, general and localized corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. Much has been learnt about the long-term corrosion behaviour of copper canisters over the past 20 years. The majority of the information reviewed here is drawn from the Swedish/Finnish and Canadian programmes. Despite differences in scientific approach, and canister and repository design, the results of these two programmes both suggest that copper provides an excellent corrosion barrier in an underground repository. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid. (orig.)

  14. Copper corrosion under expected conditions in a deep geologic repository

    International Nuclear Information System (INIS)

    King, F.; Ahonen, L.; Taxen, C.; Vuorinen, U.; Werme, L.

    2001-12-01

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 20 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear disposal repository located in he Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long- term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature.Various areas are considered: the expected evolution of the geochemical conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion before and during saturation of the compacted bentonite buffer by groundwater, general and localized corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. Much has been learnt about the long-term corrosion behaviour of copper canisters over the past 20 years. The majority of the information reviewed here is drawn from the Swedish/Finnish and Canadian programmes. Despite differences in scientific approach, and canister and repository design, the results of these two programmes both suggest that copper provides an excellent corrosion barrier in an underground repository. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid

  15. Deep repository for spent nuclear fuel. Facility description - Layout E. Spiral ramp with one operational area

    Energy Technology Data Exchange (ETDEWEB)

    Pettersson, Stig [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Forsgren, Ebbe [SwedPower AB, Stockholm (Sweden); Lange, Fritz [Lange Art AB, Stockholm (Sweden)

    2002-04-01

    This report documents a proposal for the design of the deep repository for spent nuclear fuel. The proposal is based on the principles that were formulated in the original KBS-3 study, but has been supplemented by investigations and experience to reflect current knowledge. The purpose of the report is to provide an integrated picture of the deep repository, as a basis for SKB's other work, e.g. environmental impact assessments, transport systems, safety issues and alternative locations, and to provide a co-ordinated account of the conditions and requirements concerning all of the necessary functions in the deep repository in order to have a well functioning facility. In addition, it should be possible to use the report as: a tool in the task of achieving a co-ordinated, safe and accepted design for the facility, a basis for further planning and costing, a basis for adaptation to geographic and other conditions for the particular location, a basis for information material, both within SKB and for interested parties outside, such as public authorities, municipalities and the general public. The capacity of the deep repository has been chosen on the basis of 40 years of operation of the Swedish nuclear power reactors, which will produce approximately 9,000 tons of uranium, equivalent to approximately 4,500 canisters. The design outlined is based on theoretical analyses of functions, safety requirements, procedures etc. that can be identified during the various phases of the construction and operation of the repository. In addition, preliminary organisation and staffing plans have been drawn up, for use as the basis for planning the necessary buildings. The report gives a vision of the overall layout and function of the facility, and a proposal for the design of all individual parts of the repository. The relationships between the various parts of the repository are described, both above and below ground, as is the interplay between the part above ground and part

  16. Deep repository for spent nuclear fuel. Facility description - Layout E. Spiral ramp with one operational area

    International Nuclear Information System (INIS)

    Pettersson, Stig; Forsgren, Ebbe; Lange, Fritz

    2002-04-01

    This report documents a proposal for the design of the deep repository for spent nuclear fuel. The proposal is based on the principles that were formulated in the original KBS-3 study, but has been supplemented by investigations and experience to reflect current knowledge. The purpose of the report is to provide an integrated picture of the deep repository, as a basis for SKB's other work, e.g. environmental impact assessments, transport systems, safety issues and alternative locations, and to provide a co-ordinated account of the conditions and requirements concerning all of the necessary functions in the deep repository in order to have a well functioning facility. In addition, it should be possible to use the report as: a tool in the task of achieving a co-ordinated, safe and accepted design for the facility, a basis for further planning and costing, a basis for adaptation to geographic and other conditions for the particular location, a basis for information material, both within SKB and for interested parties outside, such as public authorities, municipalities and the general public. The capacity of the deep repository has been chosen on the basis of 40 years of operation of the Swedish nuclear power reactors, which will produce approximately 9,000 tons of uranium, equivalent to approximately 4,500 canisters. The design outlined is based on theoretical analyses of functions, safety requirements, procedures etc. that can be identified during the various phases of the construction and operation of the repository. In addition, preliminary organisation and staffing plans have been drawn up, for use as the basis for planning the necessary buildings. The report gives a vision of the overall layout and function of the facility, and a proposal for the design of all individual parts of the repository. The relationships between the various parts of the repository are described, both above and below ground, as is the interplay between the part above ground and part below

  17. Source terms; isolation and radiological consequences of carbon-14 waste in the Swedish SFR repository

    International Nuclear Information System (INIS)

    Hesboel, R.; Puigdomenech, I.; Evans, S.

    1990-01-01

    The source term, isolation capacity, and long-term radiological exposure of 14 C from the Swedish underground repository for low and intermediate level waste (SFR) is assessed. The prospective amount of 14 C in the repository is assumed to be 5 TBq. Spent ion exchange resins will be the dominant source of 14 C. The pore water in the concrete repository is expected to maintain a pH of >10.5 for a period of at least 10 6 y. The cement matrix of the repository will retain most of the 14 CO 3 2- initially present. Bacterial production of CO 2 and CH 4 from degradation of ion-exchange resins and bitumen may contribute to 14 C release to the biosphere. However, CH 4 contributes only to a small extent to the overall carbon loss from freshwater ecosystems. The individual doses to local and regional individuals peaked with 5x10 -3 and regional individuals peaked with 5x10 -3 and 8x10 -4 μSv y -1 respectively at about 2.4x10 4 years. A total leakage of 8.4 GBq of 14 C from the repository will cause a total collective dose commitment of 1.1 manSv or 130 manSv TBq -1 . (authors)

  18. 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)

  19. 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

  20. Deep repository for spent nuclear fuel. SR 97 - Post-closure safety. Main Report. Summary

    International Nuclear Information System (INIS)

    Hedin, A.

    1999-11-01

    In preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Government and nuclear regulatory authorities have requested an assessment of the repository's long-term safety. The purpose is to demonstrate whether the risk of harmful effects in individuals in the vicinity of the repository complies with the acceptance criterion formulated by the Swedish regulatory authorities, i.e. that the risk may not exceed 10 -6 per year. Geological data are taken from three sites in Sweden to shed light on different conditions in Swedish granitic bedrock. The future evolution of the repository system is analyzed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings are postulated to persist. The four other scenarios show how the evolution of the repository differs from that in the base scenario if the repository contains a few initially defective canisters, in the event of climate change, earthquakes, and future inadvertent human intrusion. The time horizon for the analyses is at most one million years, in accordance with preliminary regulations. By means of model studies and calculations, the base scenario analyzes how the radioactivity of the fuel declines with time, the repository's thermal evolution as a result of the decay heat in the fuel, the hydraulic evolution in buffer and backfill when they become saturated with water, and the long-term groundwater flow in the geosphere on the three sites. The overall conclusion of the analyses in the base scenario is that the copper canisters isolating capacity is not threatened by either the mechanical or chemical stresses to which it is subjected. The safety margins are great even in a million-year perspective. The internal evolution in initially defective canisters and the possible resultant migration of radionuclides in buffer, geosphere

  1. The deep geologic repository technology programme: toward a geoscience basis for understanding repository safety

    International Nuclear Information System (INIS)

    Jensen, M.R.

    2007-01-01

    Within the Deep Geologic Repository Technology Programme (DGRTP) several Geoscience activities are focused on advancing the understanding of groundwater flow system evolution and geochemical stability in a Canadian Shield setting as affected by long-term climate change. A key aspect is developing confidence in predictions of groundwater flow patterns and residence times as they relate to the safety of a deep geologic repository for used nuclear fuel waste. This is being achieved through a coordinated multi-disciplinary approach intent on: i) demonstrating coincidence between independent geo-scientific data; ii) improving the traceability of geo-scientific data and its interpretation within a conceptual descriptive model(s); iii) improving upon methods to assess and demonstrate robustness in flow domain prediction(s) given inherent flow domain uncertainties (i.e. spatial chemical/physical property distributions, boundary conditions) in time and space; and iv) improving awareness amongst geo-scientists as to the utility of various geo-scientific data in supporting a safety case for a deep geologic repository. This multi-disciplinary DGRTP approach is yielding an improved understanding of groundwater flow system evolution and stability in Canadian Shield settings that is further contributing to the geo-scientific basis for understanding and communicating aspects of DGR safety. (author)

  2. 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

  3. 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.

  4. Siting of a deep repository for spent fuel - how are we communicating the risks?

    International Nuclear Information System (INIS)

    Hammarstroem, Monika

    2000-01-01

    During 1998 the strategy of the Swedish Nuclear Waste Management Company for the siting process was refined in order to strengthen the possibilities for implementing deep geological disposal of spent nuclear fuel. Our new organisation was formed to meet the demands of the strategy. The strategy implies focused activities in municipalities where we are performing so called feasibility studies. An important milestone for us is to be able to choose two sites for site investigations in 2001. The problem of waste exists and has to be taken care of in Sweden. The work is performed in steps to ensure dialogue and changes and modifications if needed. The method for solution is robust, a repository can be constructed in a reasonable time and ensure safety in a long-term perspective Our attitude shall be characterised by high quality and competence in all aspects.Honesty and openness are key words. The fear that people feels regarding radioactive waste shall be taken seriously. We are proud to be able to show one already existing waste management system and of our knowledge and experiences. The results so far from the various communication activities show that we are going in the right direction. The support we are gaining from various sectors in society together with our own motivation and clear objectives will, I'm sure, lead us to at least two sites for site investigations for a deep repository in Sweden by the end of 2001

  5. From the repository to the deep geological repository - and back to the Terrain surface?

    International Nuclear Information System (INIS)

    Lahodynsky, R.

    2011-01-01

    How deep is 'safe'? How long is long-term? How and for how long will something be isolated? Which rock, which formation and which location are suitable? A repository constructed for the safekeeping of radioactive or highly toxic wastes can be erected either on the surface, near the surface or underground. Radioactive waste is currently often stored at near-surface locations. The storage usually takes place nearby of a nuclear power plant in pits or concrete tombs (vaults). However, repositories can also be found in restricted areas, e.g. near nuclear weapon production or reprocessing plants (WAA) or nuclear weapons test sites (including Tomsk, Russia, Hanford and Nevada desert, USA), or in extremely low rainfall regions (South Africa). In addition there are disused mines which are now used as underground repositories. Low-level and medium-active (SMA) but also high-level waste (HAA) are stored at these types of sites (NPP, WAA, test areas, former mines). In Russia (Tomsk, Siberia) liquid radioactive waste has been injected into deep geological formations for some time (Minatom, 2001). However, all these locations are not the result of a systematic, scientific search or a holistic process for finding a location, but the result of political decisions, sometimes ignoring scientific findings. Why underground storage is given preference over high-security landfill sites (HSD) often has economic reasons. While a low safety standard can significantly reduce the cost of an above-ground high-security landfill as a waste disposal depot, spending remains high, especially due to the need for capital formation to cover operating expenses after filling the HSD. In the case of underground storage, on the other hand, no additional expenses are required for the period after backfilling. The assumption of lower costs for a deep repository runs through the past decades and coincides with the assumption that the desired ideal underground conditions actually exist and will

  6. Kincardine deep geologic repository proposal and the public

    International Nuclear Information System (INIS)

    Squire, T.

    2005-01-01

    'Full text:' In 2002, the Municipality of Kincardine and OPG signed a Memorandum of Understanding (MOU) regarding the long-term management of low and intermediate level radioactive wastes. The purpose of the MOU was for OPG, in consultation with Kincardine, to develop a plan for the long-term management of low and intermediate level waste at OPG's Western Waste Management Facility (WWMF) located on the Bruce site. An independent assessment, which included geotechnical feasibility and safety analyses, a community attitude survey and interviews with local residents, businesses and tourists, and economic modeling to determine the potential benefits and impacts, was completed in February 2004. Ultimately, Kincardine Council endorsed a resolution (Kincardine Council no. 2004-232) to: 'endorse the opinion of the Nuclear Waste Steering Committee and select the 'Deep Rock Vault' option as the preferred course of study in regards to the management of low and intermediate level radioactive waste'. The surrounding municipalities of Saugeen Shores, Brockton, Arran-Elderslie, and Huron-Kinloss expressed their support for the Deep Geologic Repository proposal. This presentation discusses the history, major steps and public processes surrounding the Kincardine Deep Geologic Repository proposal. (author)

  7. SR 97: post-closure safety of a deep repository for spent nuclear fuel in Sweden

    International Nuclear Information System (INIS)

    2000-01-01

    A major activity of the Nuclear Energy Agency (NEA) in the field of radioactive waste management is the organisation of independent, international peer reviews of national studies and projects. The NEA peer reviews help national programmes to assess their achievements. The review reports also provide reference information to be shared with others on what is desirable and what is feasible. This report presents the common views of the International Review Team (IRT) established by the NEA Secretariat on behalf of the Swedish Nuclear Power Inspectorate (SKI) to perform a peer review of a post-closure safety study of a deep repository for spent nuclear fuel in Sweden, Safety Report 97, produced by the Swedish Spent Fuel and Waste Management Company (SKB). The review is based on the main reports of the project and supporting documents, on information exchanged with SKB staff both through the intermediary of SKI and in direct interaction at a week-long workshop in Sweden, on a visit of the SKB's Aespoe Hard Rock Laboratory and Canister Laboratory, as well as on internal discussions within the IRT. (authors)

  8. Deep repository for spent nuclear fuel. SR 97 - Post-closure safety. Main Report. Summary

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, A. [ed.

    1999-11-01

    In preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Government and nuclear regulatory authorities have requested an assessment of the repository's long-term safety. The purpose is to demonstrate whether the risk of harmful effects in individuals in the vicinity of the repository complies with the acceptance criterion formulated by the Swedish regulatory authorities, i.e. that the risk may not exceed 10{sup -6} per year. Geological data are taken from three sites in Sweden to shed light on different conditions in Swedish granitic bedrock. The future evolution of the repository system is analyzed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings are postulated to persist. The four other scenarios show how the evolution of the repository differs from that in the base scenario if the repository contains a few initially defective canisters, in the event of climate change, earthquakes, and future inadvertent human intrusion. The time horizon for the analyses is at most one million years, in accordance with preliminary regulations. By means of model studies and calculations, the base scenario analyzes how the radioactivity of the fuel declines with time, the repository's thermal evolution as a result of the decay heat in the fuel, the hydraulic evolution in buffer and backfill when they become saturated with water, and the long-term groundwater flow in the geosphere on the three sites. The overall conclusion of the analyses in the base scenario is that the copper canisters isolating capacity is not threatened by either the mechanical or chemical stresses to which it is subjected. The safety margins are great even in a million-year perspective. The internal evolution in initially defective canisters and the possible resultant migration of radionuclides in

  9. Integrated account of method, site selection and programme prior to the site investigation phase[Planning for a Swedish repository for spent nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    applications and have these applications reviewed by the appropriate authorities. An analysis of conceivable alternatives for managing and disposing of spent nuclear fuel has confirmed that deep geological disposal according to the KBS-3 method has the best prospects of meeting all requirements. The alternative of putting off a decision until some future time (the zero alternative) does not appear tenable. The assessment of long-term safety shows that the prospects of building a safe deep repository in the Swedish bedrock are good. Independent Swedish and international review of the safety assessment confirm that the body of data in this respect is adequate for the siting process to proceed to the site investigation phase. A fuller summary is given below of the account given in this report of method as well as site selection and programme for the site investigation phase. The point of departure for the account is the review comments made by the regulatory authorities and the Government's decision regarding RD and D-Programme 98. In its decision, the Government stipulated conditions for SKB's continued research and development programme. The analysis of alternative system designs was to be supplemented, mainly with regard to the zero alternative and very deep boreholes. Furthermore, the Government decided that SKB shall submit an integrated evaluation of completed feasibility studies and other background material for selection of sites for site investigations and present a clear programme for site investigations.

  10. Simulating Earthquake Rupture and Off-Fault Fracture Response: Application to the Safety Assessment of the Swedish Nuclear Waste Repository

    KAUST Repository

    Falth, B.; Hokmark, H.; Lund, B.; Mai, Paul Martin; Roberts, R.; Munier, R.

    2014-01-01

    To assess the long-term safety of a deep repository of spent nuclear fuel, upper bound estimates of seismically induced secondary fracture shear displacements are needed. For this purpose, we analyze a model including an earthquake fault, which

  11. Local decision-making facing issues of national interest experiences from the swedish siting process for a spent nuclear fuel repository

    International Nuclear Information System (INIS)

    Soderberg, O.

    1998-01-01

    It is common knowledge that there are difficulties in convincing the general public and their democratically elected representatives that final disposal of spent nuclear fuel can be made in safe way. Special problems for the decision-makers are created by the demands put on today's generations to make a responsible risk assessment in a area with genuine uncertainties and characterised by any expressions of lack of confidence in social institutions. The current Swedish process for siting a deep repository for spent nuclear fuel has evolved during a period of many years, through inputs by the industry, Government, regulatory authorities and concerned municipalities. It is clear that the nuclear industry, represented by the Swedish Nuclear Fuel and Waste Management CO (SKB), has the full responsibility to find a solution to the waste management problem and to implement the solution - and to for this under the supervision of Government and regulating authorities. But, given the strong tradition of local self-government, the concerned municipalities, the local population in this process. this is simply the following fact: For people who have engaged themselves in local politics - and are prepared to take their responsibility for the well-being and development of their local community - the issue of a possible nuclear repository in the neighbourhood is difficult to handle. A relevant question is: Why should the nation as a whole expect these locally elected representatives to feel a responsibility for an issue of national importance? (author)

  12. Scientific basis for a safety case of deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Noseck, Ulrich; Becker, Dirk-Alexander; Brasser, Thomas [and others

    2012-11-15

    Within this project strategies and methods to build a safety case for deep geological repositories are further developed. This includes also the scientific fundamentals as a basis of the safety case. In the international framework the methodology of the Safety Case is frequently applied and continuously improved. According to definitions from IAEA and NEA the Safety Case is a compilation of arguments and facts, which describe, quantify and support the safety and the degree of confidence in the safety of the geological repository. The safety of the geological repository should be demonstrated by the safety case. The safety case is the basis for essential decisions during a repository programme. It comprises the results of safety assessments in combination with additional information like multiple lines of evidence and a discussion of robustness and quality of the repository, its design and the quality of all safety assessments including the basic assumptions. A crucial element of the Safety Case is the long-term safety analysis, i.e. the systematic analysis of the hazards connected with the facility and the capability of site and repository design to ensure the required safety functions and to fulfill the technical claims. Long-term safety analysis requires a powerful and qualified programme package, which contains appropriate hardware and software as well as well trained and experienced modellers performing the model calculations. The calculation tools used within safety cases need to be checked and verified and continuously adapted to the state-of-the-art science and technology. Especially it needs to be applicable to a real repository system. For the assessment of safety a deep process understanding is necessary. The R and D work performed within this project will contribute to the improvement of process and system understanding as well as to the further development of methods and strategies applied in the safety case. Emphasis was put on the following aspects

  13. Scientific basis for a safety case of deep geological repositories

    International Nuclear Information System (INIS)

    Noseck, Ulrich; Becker, Dirk-Alexander; Brasser, Thomas

    2012-11-01

    Within this project strategies and methods to build a safety case for deep geological repositories are further developed. This includes also the scientific fundamentals as a basis of the safety case. In the international framework the methodology of the Safety Case is frequently applied and continuously improved. According to definitions from IAEA and NEA the Safety Case is a compilation of arguments and facts, which describe, quantify and support the safety and the degree of confidence in the safety of the geological repository. The safety of the geological repository should be demonstrated by the safety case. The safety case is the basis for essential decisions during a repository programme. It comprises the results of safety assessments in combination with additional information like multiple lines of evidence and a discussion of robustness and quality of the repository, its design and the quality of all safety assessments including the basic assumptions. A crucial element of the Safety Case is the long-term safety analysis, i.e. the systematic analysis of the hazards connected with the facility and the capability of site and repository design to ensure the required safety functions and to fulfill the technical claims. Long-term safety analysis requires a powerful and qualified programme package, which contains appropriate hardware and software as well as well trained and experienced modellers performing the model calculations. The calculation tools used within safety cases need to be checked and verified and continuously adapted to the state-of-the-art science and technology. Especially it needs to be applicable to a real repository system. For the assessment of safety a deep process understanding is necessary. The R and D work performed within this project will contribute to the improvement of process and system understanding as well as to the further development of methods and strategies applied in the safety case. Emphasis was put on the following aspects

  14. Corrosion of high purity copper as engineering barrier in deep geological repositories

    International Nuclear Information System (INIS)

    Ochoa, Maité; Rodríguez Martín, A.; Farina Silvia, B.

    2013-01-01

    Pure copper with oxygen content below 5 ppm (to minimize segregation at grain boundaries) and doped with phosphorus (to increase creep resistance) is the chosen material for the corrosion-resistant barrier of the High Level Radioactive 2 Wastecontainers in the Swedish and Finnish repository models. These models include the construction of the repository below the water table, which is a reducing environment in which copper has excellent resistance to general and localized corrosion in aqueous electrolytes. The aim of this work is contribute to determine the durability of the material, given that deep geological repositories of HLW are designed to ensure the protection of the environment for periods of hundreds of thousands years. As a first step in a more general analysis the effects of chloride, one of the main aggressive species of corrosion, are evaluated. To this purpose corrosion potential was determined and anodic polarization curves were performed in deaerated solutions varying the chloride concentration between 0.01 and 1M and the temperature between 30 and 90°C. Several electrochemical techniques were used: the evolution of corrosion potential was measured, anodic polarization curves were obtained and electrochemical impedance tests were performed. The analysis was complemented with microscopic observations of the type of corrosive attack, as well as determinations of the eventual corrosion products formed using Energy-Dispersive X-ray Analysis (EDS). Results show that the corrosion potential decreases with the increase of temperature and with the increase of chloride concentration. A correlation of the corrosion potential as a function of temperature and chloride concentration was obtained, with the purpose of making predictions in variable conditions.The current density increases both with temperature and with chloride concentration. A pitting potential is observed in certain conditions. (author)

  15. Communication on the Safety Case for a Deep Geological Repository

    International Nuclear Information System (INIS)

    Bailey, Lucy; Bernier, Frederik; Bollingerfehr, Wilhelm; Cunado, Miguel; Ilett, Doug; Kwong, Gloria; ); Noseck, Ulrich; Roehlig, Klaus; Van Luik, Abe; Weber, Jan; Weetjens, Eef

    2017-01-01

    Communication has a specific role to play in the development of deep geological repositories. Building trust with the stakeholders involved in this process, particularly within the local community, is key for effective communication between the authorities and the public. There are also clear benefits to having technical experts hone their communication skills and having communication experts integrated into the development process. This report has compiled lessons from both failures and successes in communicating technical information to non-technical audiences. It addresses two key questions in particular: what is the experience base concerning the effectiveness or non-effectiveness of different tools for communicating safety case results to a non-technical audience and how can communication based on this experience be improved and included into a safety case development effort from the beginning? (authors)

  16. Modelling of gas generation in deep geological repositories after closure

    International Nuclear Information System (INIS)

    Poller, A.; Mayer, G.; Darcis M; Smith, P.

    2016-12-01

    In deep geological repositories for radioactive waste, significant quantities of gases will be generated in the long term as a result of various processes, notably the anaerobic corrosion of metals and the degradation of organic materials. Therefore, the impact of gas production on post-closure safety of the repositories needs to be assessed as part of a safety case. The present report provides a comprehensive description of the quantitative modelling of gas generation and associated water consumption during the post-closure phase of deep geological repositories in Opalinus Clay based on current scientific knowledge and on current preliminary repository designs. This includes a presentation of the modelling basis, namely the conceptual and mathematical models, the input data used, the computer tools developed, the relevant uncertainties and principal programme / design options, as well as the derivation, analysis and discussion of specific assessment cases. The modelling is carried out separately for the two main sources of gas, which are the emplaced waste including the disposal containers; and the construction materials. The contribution of construction materials to gas generation rates in emplacement tunnels for spent fuel (SF) and vitrified high-level waste (HLW) is significant during several thousand years after closure. In the long term, however, the corrosion of the disposal canisters, which are in the reference case assumed to be fabricated of carbon steel, accounts for the vast majority of the total gas produced in these tunnels. The contribution of construction materials in emplacement caverns for long lived intermediate-level waste (ILW) and low- and intermediate-level waste (L/ILW) to gas generation is generally small. In ILW emplacement caverns, gas generation is generally dominated by hydrogen generation from the corrosion of cast iron Mosaik-II waste containers for PWR internals and from the corrosion of aluminium in operational waste from the

  17. Modelling of gas generation in deep geological repositories after closure

    Energy Technology Data Exchange (ETDEWEB)

    Poller, A. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Mayer, G.; Darcis M [AF-Consult Switzerland Ltd, Baden-Dättwil, (Switzerland); Smith, P. [Safety Assessment Management Ltd, Henley-On-Thames, Oxfordshire (United Kingdom)

    2016-12-15

    In deep geological repositories for radioactive waste, significant quantities of gases will be generated in the long term as a result of various processes, notably the anaerobic corrosion of metals and the degradation of organic materials. Therefore, the impact of gas production on post-closure safety of the repositories needs to be assessed as part of a safety case. The present report provides a comprehensive description of the quantitative modelling of gas generation and associated water consumption during the post-closure phase of deep geological repositories in Opalinus Clay based on current scientific knowledge and on current preliminary repository designs. This includes a presentation of the modelling basis, namely the conceptual and mathematical models, the input data used, the computer tools developed, the relevant uncertainties and principal programme / design options, as well as the derivation, analysis and discussion of specific assessment cases. The modelling is carried out separately for the two main sources of gas, which are the emplaced waste including the disposal containers; and the construction materials. The contribution of construction materials to gas generation rates in emplacement tunnels for spent fuel (SF) and vitrified high-level waste (HLW) is significant during several thousand years after closure. In the long term, however, the corrosion of the disposal canisters, which are in the reference case assumed to be fabricated of carbon steel, accounts for the vast majority of the total gas produced in these tunnels. The contribution of construction materials in emplacement caverns for long lived intermediate-level waste (ILW) and low- and intermediate-level waste (L/ILW) to gas generation is generally small. In ILW emplacement caverns, gas generation is generally dominated by hydrogen generation from the corrosion of cast iron Mosaik-II waste containers for PWR internals and from the corrosion of aluminium in operational waste from the

  18. Project SAFE. Modelling of long-term concrete degradation processes in the Swedish SFR repository

    Energy Technology Data Exchange (ETDEWEB)

    Hoeglund, L.O. [Kemakta Konsult AB, Stockholm (Sweden)

    2001-04-01

    This study concerns the leaching of concrete barriers, in particular the silo construction, in the Swedish SFR repository for low and intermediate level radioactive waste. A conceptual model for the leaching of concrete in a saline groundwater has been proposed based on the increased understanding achieved from research studies presented in the literature. The conceptual model has been used to set up a numerical model for the complex chemical interactions between the cement minerals of the concrete with the groundwater. The calculations show that various chemical reactions are expected to occur in the concrete over time. Different cases have been calculated. The results show that the chemical conditions in the concrete barriers will maintain alkaline for long time. In the most exposed parts of the concrete a high degree of leaching can be expected during the considered 10,000 years, whereas only for the most unfavourable assumptions (initially fractured concrete with groundwater flow-through) the inner parts of the concrete will be degraded to any significant degree.

  19. Project SAFE. Modelling of long-term concrete degradation processes in the Swedish SFR repository

    International Nuclear Information System (INIS)

    Hoeglund, L.O.

    2001-04-01

    This study concerns the leaching of concrete barriers, in particular the silo construction, in the Swedish SFR repository for low and intermediate level radioactive waste. A conceptual model for the leaching of concrete in a saline groundwater has been proposed based on the increased understanding achieved from research studies presented in the literature. The conceptual model has been used to set up a numerical model for the complex chemical interactions between the cement minerals of the concrete with the groundwater. The calculations show that various chemical reactions are expected to occur in the concrete over time. Different cases have been calculated. The results show that the chemical conditions in the concrete barriers will maintain alkaline for long time. In the most exposed parts of the concrete a high degree of leaching can be expected during the considered 10,000 years, whereas only for the most unfavourable assumptions (initially fractured concrete with groundwater flow-through) the inner parts of the concrete will be degraded to any significant degree

  20. Change of roles and attitudes in the Swedish localisation process for a final repository

    International Nuclear Information System (INIS)

    Hedberg, Bjoern

    2001-01-01

    Since the early research activities in the mid seventies related to a final repository for spent nuclear fuel and other radioactive wastes, much has changed in a direction that allows a more open and transparent decision-making process. Important changes have been noted in the legal framework - including EIA and financing - and in the roles of the Swedish authorities, local politicians, NGO's, and media. Trust and credibility is of course crucial for all actors in the decision-making process, but the ways to gain trust is different depending on which role to play in the process. A higher degree of trust in the different actors, and in the process itself, could be gained from a better distinction between facts and value judgements, but also if the roles of different actors are better clarified. To understand the roles of the different actors, it is important to define each actor's 'arena' in terms of responsibilities, goals, standpoints etc. in several dimensions. These dimensions could for example be geographic or the base for decisions (scientific - political)

  1. Change of roles and attitudes in the Swedish localisation process for a final repository

    Energy Technology Data Exchange (ETDEWEB)

    Hedberg, Bjoern [Swedish Radiation Protection Inst., Stockholm (Sweden)

    2001-07-01

    Since the early research activities in the mid seventies related to a final repository for spent nuclear fuel and other radioactive wastes, much has changed in a direction that allows a more open and transparent decision-making process. Important changes have been noted in the legal framework - including EIA and financing - and in the roles of the Swedish authorities, local politicians, NGO's, and media. Trust and credibility is of course crucial for all actors in the decision-making process, but the ways to gain trust is different depending on which role to play in the process. A higher degree of trust in the different actors, and in the process itself, could be gained from a better distinction between facts and value judgements, but also if the roles of different actors are better clarified. To understand the roles of the different actors, it is important to define each actor's 'arena' in terms of responsibilities, goals, standpoints etc. in several dimensions. These dimensions could for example be geographic or the base for decisions (scientific - political)

  2. 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

  3. Deep repository for spent nuclear fuel. SR-97-Post-closure safety. Main Report. Volume I and II

    International Nuclear Information System (INIS)

    Hedin, A.

    1999-11-01

    In preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Government and nuclear regulatory authorities have requested an assessment of the repository's long-term safety. The purpose is to demonstrate whether the risk of harmful effects in individuals in the vicinity of the repository complies with the acceptance criterion formulated by the Swedish regulatory authorities, i.e. that the risk may not exceed 10 -6 per year. Geological data are taken from three sites in Sweden to shed light on different conditions in Swedish granitic bedrock. The future evolution of the repository system is analyzed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings are postulated to persist. The four other scenarios show how the evolution of the repository differs from that in the base scenario if the repository contains a few initially defective canisters, in the event of climate change, earthquakes, and future inadvertent human intrusion. The time horizon for the analyses is at most one million years, in accordance with preliminary regulations. By means of model studies and calculations, the base scenario analyzes how the radioactivity of the fuel declines with time, the repository's thermal evolution as a result of the decay heat in the fuel, the hydraulic evolution in buffer and backfill when they become saturated with water, and the long-term groundwater flow in the geosphere on the three sites. The overall conclusion of the analyses in the base scenario is that the copper canisters isolating capacity is not threatened by either the mechanical or chemical stresses to which it is subjected. The safety margins are great even in a million-year perspective. The internal evolution in initially defective canisters and the possible resultant migration of radionuclides in buffer, geosphere

  4. Earthquakes - a danger to deep-lying repositories?; erdbeben: eine gefahr fuer tiefenlager?

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-03-15

    This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at geological factors concerning earthquakes and the safety of deep-lying repositories for nuclear waste. The geological processes involved in the occurrence of earthquakes are briefly looked at and the definitions for magnitude and intensity of earthquakes are discussed. Examples of damage caused by earthquakes are given. The earthquake situation in Switzerland is looked at and the effects of earthquakes on sub-surface structures and deep-lying repositories are discussed. Finally, the ideas proposed for deep-lying geological repositories for nuclear wastes are discussed.

  5. Earthquakes: no danger for deep underground nuclear waste repositories

    International Nuclear Information System (INIS)

    2010-03-01

    On the Earth, the continental plates are steadily moving. Principally at the plate boundaries such shifts produce stresses which are released in form of earthquakes. The highest the built-up energy, the more violent will be the shaking. Earthquakes accompany mankind from very ancient times on and they disturb the population. Till now nobody is able to predict where and when they will take place. But on the Earth there are regions where, due to their geological situation, the occurrence of earthquakes is more probable than elsewhere. The impact of a very strong earthquake on the structures at the Earth surface depends on several factors. Besides the ground structure, the density of buildings, construction style and materials used play an important role. Construction-related technical measures can improve the safety of buildings and, together with a correct behaviour of the people concerned, save many lives. Earthquakes are well known in Switzerland. Here, the stresses are due to the collision of the African and European continental plates that created the Alps. The impact of earthquake is more limited in the underground than at the Earth surface. There is no danger for deep underground repositories

  6. Deep repository. Underground design premises. Edition D1/1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2004-09-01

    This report proposes design premises and methodology for application in the preliminary design of underground excavations within the framework of SKB's site investigations. The design premises and supporting instructions for rock mechanical and hydrogeological analyses are a result of planning work carried out between the autumn of 2002 and the spring of 2003. Other overall planning has also been done at the same time for the Deep Repository Project. The first draft underwent revision following a seminar on 30 June 2003 primarily with respect to structure and coordination aspects within the project, as well as certain factual questions. That version served as a basis for an application exercise based on site descriptive model version 1.1 Forsmark. The purpose of the application exercise was to: Test relevant portions of the proposed methodology for rock engineering for the initial site investigations (ISI); Evaluate the application of preliminary design requirements; Identify and develop proposals for collaboration between design and site and site modelling units for the best possible feedback in future work, especially iterations for meeting the needs of design; Identify and develop proposals for collaboration between safety assessment and design for realistic proposals for site adaptation. The design application exercise was evaluated at the end of 2003 and its results serve as an important basis for revisions. The update was commenced with a workshop in February 2004, where the goals were established.

  7. Deep repository. Underground design premises. Edition D1/1

    International Nuclear Information System (INIS)

    2004-09-01

    This report proposes design premises and methodology for application in the preliminary design of underground excavations within the framework of SKB's site investigations. The design premises and supporting instructions for rock mechanical and hydrogeological analyses are a result of planning work carried out between the autumn of 2002 and the spring of 2003. Other overall planning has also been done at the same time for the Deep Repository Project. The first draft underwent revision following a seminar on 30 June 2003 primarily with respect to structure and coordination aspects within the project, as well as certain factual questions. That version served as a basis for an application exercise based on site descriptive model version 1.1 Forsmark. The purpose of the application exercise was to: Test relevant portions of the proposed methodology for rock engineering for the initial site investigations (ISI); Evaluate the application of preliminary design requirements; Identify and develop proposals for collaboration between design and site and site modelling units for the best possible feedback in future work, especially iterations for meeting the needs of design; Identify and develop proposals for collaboration between safety assessment and design for realistic proposals for site adaptation. The design application exercise was evaluated at the end of 2003 and its results serve as an important basis for revisions. The update was commenced with a workshop in February 2004, where the goals were established

  8. General construction requirements for the deep repository in the KBS-3 system

    International Nuclear Information System (INIS)

    2002-10-01

    The KBS-3 systems includes equipment and plants for transport of spent nuclear fuels and encapsulated spent fuels, central intermediate storage, encapsulation and deep geologic disposal. The requirements in this document concern the repository and have been put together in view of the tasks of designing, constructing and building the repository. The report presents: A general review of existing design plans; Laws and regulations relevant for the design of the repository; How the regulations have been broken down to functional demands and dimensioning requirements for the repository; How the site conditions influence the design, and how the layout of the different parts of the repository interact; Relations between the functions of the repository, the safety and the design; A foundation for developing construction plans for the repository. The requirements will be collected in a database that will develop as new knowledge is collected

  9. 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

  10. 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.

  11. Siting regions for deep geological repositories. Why just here?

    International Nuclear Information System (INIS)

    Rieser, A.

    2009-09-01

    This report helps to the popularization of the Nagra works accomplished for the management and disposal of the radioactive wastes in Switzerland. The programme for management and disposal of the radioactive wastes are extensively determined by regulations. Protection of mankind and environment is the primary objective. The basic storage process is considered as having been solved. The question addressed in the report is where the facility has to be built; the site selection procedure includes five steps: 1) according to their type the wastes have to be allocated to two different repositories: for low- and intermediate-level wastes (L/ILW), and for high-level and alpha-toxic wastes (HLW); 2) the safety concept for both repositories and the requirements on the geology have to be determined; 3) large suitable geological-tectonic zones must be found where repositories could be built; 4) in these geological zones a suitable host rock has to be identified; 5) the most important spatial geological conditions of the host rock (minimum depth with respect to surface erosion, maximum depth in terms of engineering requirements, lateral extent) have to be identified. Based on these criteria, three suitable siting regions for a HLW repository were found in the North of Switzerland. The preferred host rock is Opalinus clay because of its very low permeability; it is therefore an excellent barrier against nuclide transport. In the three proposed siting regions, Opalinus clay is present in sufficient volumes at a suitable depth. For a L/ILW repository six different possible siting regions were identified, five in Northern Switzerland and one in Central Switzerland. In the three siting regions found for a possible HLW repository, it would also be possible to built a combined repository for both HLW and L/ILW wastes

  12. Analysis of the processes defining radionuclide migration from deep geological repositories in porous medium

    International Nuclear Information System (INIS)

    Brazauskaite, A.; Poskas, P.

    2004-01-01

    Due to the danger of exposure arising from long-lived radionuclides to humans and environment, spent nuclear fuel (SNF) and high level waste (HLW) are not allowed to be disposed of in near surface repositories. There exists an international consensus that such high level and long-lived radioactive wastes are best disposed of in geological repositories using a system of engineered and natural barriers. At present, the geological repository of SNF and HLW has not been realized yet in any country but there is a lot of experience in the assessment of radionuclide migration from deep repositories, investigations of different processes related to the safety of a disposal system. The aim of this study was to analyze the processes related to the radionuclide migration from deep geological repositories in porous medium such as SNF matrix dissolution, release mechanism of radionuclides from SNF matrix, radionuclide solubility, sorption, diffusive, advective transport of radionuclides from the canister and through the engineered and natural barriers. It has been indicated that SNF matrix dissolution, radionuclide solubility and sorption are sensitive to ambient conditions prevailing in the repository. The approaches that could be used for modeling the radionuclide migration from deep repositories in porous medium are also presented. (author)

  13. Implementation of hearings in the Swedish process for siting a spent nuclear fuel repository

    International Nuclear Information System (INIS)

    Westerlind, Magnus; Wiklund, Aasa

    2001-01-01

    treat all types of questions with equal, non-judgmental interest; Working groups to formulate questions gave the participants time for reflection and discussions without dominance by e.g. the implementer or the authorities. It is likely that many participants appreciated the possibility to be anonymous and channel questions through the moderators; Well defined scope of the hearings developed in dialogue with the municipalities; It was clear that the authorities were the owners of the hearings and that the outcome would be included in their review of SKB's programme; The early involvement of the municipalities in the planning process was essential since the hearings were held in the areas proposed for site investigations. In the further development of hearings in the Swedish nuclear waste programme a number of issues will have to be considered. The now completed hearings were essentially based on the public's questions and concerns. In the future it may be considered to also arrange hearings on an 'expert level'. It should however be kept in mind that the municipalities are experts on local conditions and must be involved since the immediate impact of a repository is local. It could also be advantageous to have hearings in two phases. The first phase should then be focussed on the implementer, e.g. on material submitted to the authorities for review. In this phase the authorities should present criteria for the review. Following this hearing the authorities should review the implementers material and present a preliminary review report. The second phase of hearings should then focus on the authorities' review report and possible supplementing submissions from the implementer. It is believed that this could be particular relevant in situations where important municipal decisions are to be made. Another and perhaps the most challenging issue, which is not unique to nuclear waste management, is how to involve the public and concerned citizens in hearings and decision making

  14. 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

  15. 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)

  16. Foreign materials in a deep repository for spent nuclear fuels

    International Nuclear Information System (INIS)

    Jones, C.; Christiansson, Aa.; Wiborgh, M.

    1999-12-01

    The effects of foreign substances introduced into a spent-fuel repository are reviewed. Possible impacts on processes and barrier-functions are examined, and the following areas are identified: Corrosion of the spent-fuel canister through the presence of sulfur and substances that favor microbial growth; impacts on the bentonite properties through the presence of cations as calcium, potassium and iron; radionuclide transport through the presence of complex-formers and surface-active substances

  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. Deep repository for spent nuclear fuel. SR-97-Post-closure safety. Main Report. Volume I and II

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, A [ed.

    1999-11-01

    In preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Government and nuclear regulatory authorities have requested an assessment of the repository's long-term safety. The purpose is to demonstrate whether the risk of harmful effects in individuals in the vicinity of the repository complies with the acceptance criterion formulated by the Swedish regulatory authorities, i.e. that the risk may not exceed 10{sup -6} per year. Geological data are taken from three sites in Sweden to shed light on different conditions in Swedish granitic bedrock. The future evolution of the repository system is analyzed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings are postulated to persist. The four other scenarios show how the evolution of the repository differs from that in the base scenario if the repository contains a few initially defective canisters, in the event of climate change, earthquakes, and future inadvertent human intrusion. The time horizon for the analyses is at most one million years, in accordance with preliminary regulations. By means of model studies and calculations, the base scenario analyzes how the radioactivity of the fuel declines with time, the repository's thermal evolution as a result of the decay heat in the fuel, the hydraulic evolution in buffer and backfill when they become saturated with water, and the long-term groundwater flow in the geosphere on the three sites. The overall conclusion of the analyses in the base scenario is that the copper canisters isolating capacity is not threatened by either the mechanical or chemical stresses to which it is subjected. The safety margins are great even in a million-year perspective. The internal evolution in initially defective canisters and the possible resultant migration of radionuclides in buffer

  19. Deep repository for spent nuclear fuel. SR-97-Post-closure safety. Main Report. Volume I and II

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, A. [ed.

    1999-11-01

    In preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Government and nuclear regulatory authorities have requested an assessment of the repository's long-term safety. The purpose is to demonstrate whether the risk of harmful effects in individuals in the vicinity of the repository complies with the acceptance criterion formulated by the Swedish regulatory authorities, i.e. that the risk may not exceed 10{sup -6} per year. Geological data are taken from three sites in Sweden to shed light on different conditions in Swedish granitic bedrock. The future evolution of the repository system is analyzed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings are postulated to persist. The four other scenarios show how the evolution of the repository differs from that in the base scenario if the repository contains a few initially defective canisters, in the event of climate change, earthquakes, and future inadvertent human intrusion. The time horizon for the analyses is at most one million years, in accordance with preliminary regulations. By means of model studies and calculations, the base scenario analyzes how the radioactivity of the fuel declines with time, the repository's thermal evolution as a result of the decay heat in the fuel, the hydraulic evolution in buffer and backfill when they become saturated with water, and the long-term groundwater flow in the geosphere on the three sites. The overall conclusion of the analyses in the base scenario is that the copper canisters isolating capacity is not threatened by either the mechanical or chemical stresses to which it is subjected. The safety margins are great even in a million-year perspective. The internal evolution in initially defective canisters and the possible resultant migration of radionuclides in

  20. Surface facilities for geological deep repositories - Measures against dangers during construction and operation

    International Nuclear Information System (INIS)

    2013-09-01

    This brochure published by the Swiss National Cooperative for the Disposal of Radioactive Waste (NAGRA) discusses the measures that are to be taken to address the dangers encountered during the construction and operation of deep geological repositories for nuclear wastes. Firstly, the operation of such repositories during the emplacement of nuclear wastes is discussed and examples of possible repositories for fuel rods and highly-radioactive waste are presented. Various emission-protection issues and safety measures to be taken during construction of such repositories are looked at as is the protection of ground water. Safety considerations during the operational phase are discussed, including inclusion methods used for the wastes and radiation protection. The handling of radioactive wastes, the recognition of dangers and measures to be taken to counteract them are discussed. Various possible accidents are looked at

  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. Evaluation of behaviour and Safety in a geologic deep repository

    International Nuclear Information System (INIS)

    1997-01-01

    This report presents a comprehensive description of the post-closure radiological safety assessment of a repository for the spent fuel arisings resulting from the Spanish nuclear program. This Safety Assessment constitutes a first step within a systematical process that will permit, thorough successive approximations, to predict the performance of the different barriers of the disposal system, and its capability to comply with the assigned safety functions and with the established safety criteria. The primary bases for this Safety Assessment are the following: The disposal concept considers the storage of the fuel assemblies in carbon steel canisters of 10 cm of thickness, emplaced horizontally in galleries excavated in granite of 2,4 m of diameter and 500 m of length, using a bentonite thickness of 75 cm around canisters as buffer material. The repository is located in a granitic site defined with available data about surface characteristics of Spanish granites. The exercise uses a probabilistic approximation in order to cope with the uncertainties associated with the different imputs parameters. (Author)

  3. Swiss plans for deep geological repositories for radioactive wastes - Basics for communication at the localities affected

    International Nuclear Information System (INIS)

    Gallego Carrera, D.; Renn, O.; Dreyer, M.

    2009-06-01

    This report for the Swiss Federal Office of Energy (SFOE) discusses the concept of how information concerning deep geological repositories for radioactive wastes should be presented and communicated to those in the areas which have been designated as potential sites for the repositories. Communication basics based on scientific knowledge in this area are discussed. The importance of a concept for general communication and risk-communication as a particular challenge are discussed. Trust and transparency are quoted as being indispensable in this connection. Ways of dealing with various target audiences and the media are examined. The report is concluded with a check-list that deals with important questions arising from the process of communicating information on deep geological repositories for radioactive wastes

  4. Site selection of a deep repository of HLRW in relation to geological conditions of Slovak Republic

    International Nuclear Information System (INIS)

    Kovacik, M.; Kovacikova, M.; Madaras, J.; Vandlikova, M.

    1996-01-01

    All countries which use nuclear energy to generate electricity face the problem of high level radioactive waste (HLRW) and spent fuel. Until 1987, this problem was addressed in Czechoslovakia by transferring the material to the former USSR. After the political changes in Central and Eastern Europe in 1989 and the division of Czechoslovakia into two states in 1993, Slovakia independently faced the complex problem of creating its own deep repository. Although Slovakia has begun to solve the problem of HLRW and spent fuel only recently, it can take advantage of the theoretical and practical knowledge of other countries in this field. The geological aspects of the setting of the deep repository of HLRW have been studied within the project R epositories of radioactive and hazardous wastes in geological environment. The assessment of the Slovak Republic for creating a repository of HLRW was based on the application of internationally determined and applied criteria

  5. Albedo Neutron Dosimetry in a Deep Geological Disposal Repository for High-Level Nuclear Waste.

    Science.gov (United States)

    Pang, Bo; Becker, Frank

    2017-04-28

    Albedo neutron dosemeter is the German official personal neutron dosemeter in mixed radiation fields where neutrons contribute to personal dose. In deep geological repositories for high-level nuclear waste, where neutrons can dominate the radiation field, it is of interest to investigate the performance of albedo neutron dosemeter in such facilities. In this study, the deep geological repository is represented by a shielding cask loaded with spent nuclear fuel placed inside a rock salt emplacement drift. Due to the backscattering of neutrons in the drift, issues concerning calibration of the dosemeter arise. Field-specific calibration of the albedo neutron dosemeter was hence performed with Monte Carlo simulations. In order to assess the applicability of the albedo neutron dosemeter in a deep geological repository over a long time scale, spent nuclear fuel with different ages of 50, 100 and 500 years were investigated. It was found out, that the neutron radiation field in a deep geological repository can be assigned to the application area 'N1' of the albedo neutron dosemeter, which is typical in reactors and accelerators with heavy shielding. © The Author 2016. Published by Oxford University Press. All rights reserved. For Permissions, please email: journals.permissions@oup.com.

  6. Chemical stability of copper-canisters in deep repository

    International Nuclear Information System (INIS)

    Ahonen, L.

    1995-12-01

    The spent fuel from Finnish nuclear reactors is planned to be encapsulated in thick-walled copper-iron canisters and placed deep into the bedrock. The copper wall of the canister provides a long-time shield against corrosion, preventing the high-level nuclear fuel from contact with ground water. In the report, stability of metallic copper and its possible corrosion reactions in the conditions of deep bedrock are evaluated by means of thermo-dynamic calculations. (90 refs., 28 figs., 11 tabs.)

  7. Integrated safety case development for deep geological repositories

    International Nuclear Information System (INIS)

    Kawamura, Hideki; McKinley, Ian G.

    2008-01-01

    The paper will illustrate an 'integrated safety case', which involves combining both pre-closure and post-closure safety arguments from the point of view of a repository implementer, who must also ensure that projects are practical, acceptable and economic. The post-closure safety case is based on the performance of a number of barriers, which are established during construction, operation and closure. Such barriers must be confirmed using quality assured methods, supported, as required, by inspection and monitoring. The requirement for integrated assessment means that even the final process to end institutional control and transfer any liabilities from the implementer needs to be considered at present, even though this will undoubtedly be refined and tailored to the site characteristics over the many decades that will pass before this occurs. To illustrate the practical application of this approach, assessment of variants for remote-handled emplacement of the EBS for disposal of HLW in Japan will be discussed. (author)

  8. The deep disposal repository - an alternative general arrangement

    International Nuclear Information System (INIS)

    Wolofsky, L.

    1996-01-01

    For the disposal of nuclear fuel waste in Canada the current proposal requires a repository at or below 500 m depth in Precambrian plutonic igneous rock in Ontario, consisting of numerous horizontal parallel tunnels arranged in one or more horizontal planes i.e. a room-and-pillar arrangement. The pillars are three times as wide as the tunnels, giving as extraction ratio of 25%. The tunnels are tentatively designed to be excavated by drill and blast, with a flat-arched roof, vertical side walls and a flat invert. The fuel containing canisters are to be surrounded by a low-permeability bentonite-based buffer in vertical holes drilled for the purpose in the invert

  9. 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

  10. Deep geological isolation of nuclear waste: numerical modeling of repository scale hydrology

    International Nuclear Information System (INIS)

    Dettinger, M.D.

    1980-04-01

    The Scope of Work undertaken covers three main tasks, described as follows: (Task 1) CDM provided consulting services to the University on modeling aspects of the study having to do with transport processes involving the local groundwater system near the repository and the flow of fluids and vapors through the various porous media making up the repository system. (Task 2) CDM reviewed literature related to repository design, concentrating on effects of the repository geometry, location and other design factors on the flow of fluids within the repository boundaries, drainage from the repository structure, and the eventual transport of radionucldies away from the repository site. (Task 3) CDM, in a joint effort with LLL personnel, identified generic boundary and initial conditions, identified processes to be modeled, and recommended a modeling approach with suggestions for appropriate simplifications and approximations to the problem and identifiying important parameters necessary to model the processes. This report consists of two chapters and an appendix. The first chapter (Chapter III of the LLL report) presents a detailed description and discussion of the modeling approach developed in this project, its merits and weaknesses, and a brief review of the difficulties anticipated in implementing the approach. The second chapter (Chapter IV of the LLL report) presents a summary of a survey of researchers in the field of repository performance analysis and a discussion of that survey in light of the proposed modeling approach. The appendix is a review of the important physical processes involved in the potential hydrologic transport of radionuclides through, around and away from deep geologic nuclear waste repositories

  11. Assessment of human intrusion and future human actions – Example from the Swedish LILW repository

    International Nuclear Information System (INIS)

    Andersson, Eva; Hjerpe, T.; Smith, G.

    2016-01-01

    Recommendations for FHA assessments: • The assumption of only considering inadvertent intrusion and using todays practice and technology is a key tool to make the assessment understandable. • Even after siting has been done, the placement of the repository, should be discussed in FHA scenarios, e.g. placement away from resources, discussion of erosion, and land uplift. • FEPs a good tool, good for constructing relevant scenarios and also for communication of the FHA assessment. • A few stylized scenarios are enough, good to include a drilling scenario as it is often used by different organizations. • Precise probabilities are hard to defend, avoid if possible and instead use the low likelihood in communication of the FHA results. • Communication of FHA scenarios is a tool to build confidence in the robustness of repository systems

  12. 3D numerical modelling of the thermal state of deep geological nuclear waste repositories

    Science.gov (United States)

    Butov, R. A.; Drobyshevsky, N. I.; Moiseenko, E. V.; Tokarev, Yu. N.

    2017-09-01

    One of the important aspects of the high-level radioactive waste (HLW) disposal in deep geological repositories is ensuring the integrity of the engineered barriers which is, among other phenomena, considerably influenced by the thermal loads. As the HLW produce significant amount of heat, the design of the repository should maintain the balance between the cost-effectiveness of the construction and the sufficiency of the safety margins, including those imposed on the thermal conditions of the barriers. The 3D finite-element computer code FENIA was developed as a tool for simulation of thermal processes in deep geological repositories. Further the models for mechanical phenomena and groundwater hydraulics will be added resulting in a fully coupled thermo-hydro-mechanical (THM) solution. The long-term simulations of the thermal state were performed for two possible layouts of the repository. One was based on the proposed project of Russian repository, and another features larger HLW amount within the same space. The obtained results describe the spatial and temporal evolution of the temperature filed inside the repository and in the surrounding rock for 3500 years. These results show that practically all generated heat was ultimately absorbed by the host rock without any significant temperature increase. Still in the short time span even in case of smaller amount of the HLW the temperature maximum exceeds 100 °C, and for larger amount of the HLW the local temperature remains above 100 °C for considerable time. Thus, the substantiation of the long-term stability of the repository would require an extensive study of the materials properties and behaviour in order to remove the excessive conservatism from the simulations and to reduce the uncertainty of the input data.

  13. SKI SITE-94. Deep Repository Performance Assessment Project Volume I and II

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-12-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry`s R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is not a safety assessment or a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The report gives a detailed description of the many inter-related studies undertaken as part of the research project. As a general conclusion it is noted that the SITE-94 project has significantly advanced SKI`s capability of reviewing performance assessments and has led to the development of a tool-kit for carrying out assessment calculations, both in terms of numerical and scoping analyses. The study has highlighted a number of key issues for safety assessment (and consequently for disposal system design): Canister performance; Derived parameters of geosphere retention properties; Spatial variability of groundwater flow and geochemistry of migration paths; Time dependency (more emphasis on transient, time-dependent processes); Buffer evolution over long time. 488 refs.

  14. SKI SITE-94. Deep Repository Performance Assessment Project Volume I and II

    International Nuclear Information System (INIS)

    1996-12-01

    The function of SITE-94 is to provide the Swedish Nuclear Power Inspectorate (SKI) with the capacity and supporting knowledge needed for reviewing the Swedish nuclear industry's R and D programs and for reviewing license applications, as stipulated in Swedish legislation. The report is structured as a Performance Assessment exercise needed for input to decisions regarding repository safety, but the SITE-94 is not a safety assessment or a model for future assessments to be undertaken by the prospective licensee. The specific project objectives of SITE-94 comprise site evaluation, performance assessment methodology, canister integrity and radionuclide release and transport calculations. The report gives a detailed description of the many inter-related studies undertaken as part of the research project. As a general conclusion it is noted that the SITE-94 project has significantly advanced SKI's capability of reviewing performance assessments and has led to the development of a tool-kit for carrying out assessment calculations, both in terms of numerical and scoping analyses. The study has highlighted a number of key issues for safety assessment (and consequently for disposal system design): Canister performance; Derived parameters of geosphere retention properties; Spatial variability of groundwater flow and geochemistry of migration paths; Time dependency (more emphasis on transient, time-dependent processes); Buffer evolution over long time. 488 refs

  15. Considerations on pressure build-up in deep geological repositories for radioactive waste

    International Nuclear Information System (INIS)

    Beer, Hans-Frieder

    2015-01-01

    Gas formation caused by corrosion of metals is a pivotal point with respect to the safety analysis of deep geological repositories. Solid corrosion products are formed unavoidably during the gas formation. The volumes of these solid corrosion products are multiples of the original waste volume. These solid corrosion products are chemically extremely stable and result in a pressure increase inside the repository. This pressure is considerably higher than that of the overlaying rock. The question that arises is, why this aspect is not considered in the consulted documents.

  16. Siting regions for deep geological repositories. Nagra’s proposals for stage 3

    International Nuclear Information System (INIS)

    2014-01-01

    This brochure published by the Swiss National Cooperative for the Disposal of Radioactive Waste (NAGRA) discusses the selection of sites for deep geological repositories for nuclear wastes in Switzerland. The procedure proposed for the selection process is explained. The four sites for possible repositories of high-level radioactive waste as well as for low and intermediate-level wastes are described and rated with respect to the various safety factors involved. The reasons for the long-term safety measures proposed and the geological barriers involved are discussed. The four proposals for depository sites are looked at in more detail. The paper is well illustrated with several diagrams and tables

  17. Repositories for Deep, Dark, and Offline Data - Building Grey Literature Repositories and Discoverability

    Science.gov (United States)

    Keane, C. M.; Tahirkheli, S.

    2017-12-01

    Data repositories, especially in the geosciences, have been focused on the management of large quantities of born-digital data and facilitating its discovery and use. Unfortunately, born-digital data, even with its immense scale today, represents only the most recent data acquisitions, leaving a large proportion of the historical data record of the science "out in the cold." Additionally, the data record in the peer-reviewed literature, whether captured directly in the literature or through the journal data archive, represents only a fraction of the reliable data collected in the geosciences. Federal and state agencies, state surveys, and private companies, collect vast amounts of geoscience information and data that is not only reliable and robust, but often the only data representative of specific spatial and temporal conditions. Likewise, even some academic publications, such as senior theses, are unique sources of data, but generally do not have wide discoverability nor guarantees of longevity. As more of these `grey' sources of information and data are born-digital, they become increasingly at risk for permanent loss, not to mention poor discoverability. Numerous studies have shown that grey literature across all disciplines, including geosciences, disappears at a rate of about 8% per year. AGI has been working to develop systems to both improve the discoverability and the preservation of the geoscience grey literature by coupling several open source platforms from the information science community. We will detail the rationale, the technical and legal frameworks for these systems, and the long-term strategies for improving access, use, and stability of these critical data sources.

  18. Postcards from the past: Archaeological and industrial analogs for deep repository materials

    International Nuclear Information System (INIS)

    Miller, B.; Chapman, N.

    1995-01-01

    Many recent performance assessments of deep geological repositories for radioactive wastes suggest that the engineered barrier system plays the cominant role in reducing releases of radionuclides to the surface environment. There is a considerable impetus to demonstrate the longevity of engineered barrier system components. Although many of the materials are familiar, the requirement for predictable behavior and longevity in a repository is unlike any other requirements of the past. A full appreciation of the acceptability of repository materials can only be reached from a combination of complementary field, laboratory, and natural analog studies. This article discusses analogs from archaelogy and industry. Topics covered include what makes a good analog; long term material behavior (from archeological studies) of metals, glass,cements and concrete, bitumens, and betonite; investigations of radionuclide transport and material interactions. 4 figs., 3 tabs

  19. Important processes affecting the release and migration of radionuclides from a deep geological repository

    International Nuclear Information System (INIS)

    Barátová, Dana; Nečas, Vladimír

    2017-01-01

    The processes that affect significantly the transport of contaminants through the near field and far field of a deep geological repository of spent nuclear fuel were studied. The processes can be generally divided into (i) processes related to the release of radionuclides from the spent nuclear fuel; (ii) processes related to the radionuclide transport mechanisms (such as advection and diffusion); and (iii) processes affecting the rate of radionuclide migration through the multi-barrier repository system. A near-field and geosphere model of an unspecified geological repository sited in a crystalline rock is also described. Focus of the treatment is on the effects of the different processes on the activity flow of the major safety-relevant radionuclides. The activity flow was simulated for one spent fuel cask by using the GoldSim simulation tool. (orig.)

  20. Deep repository for long-lived low- and intermediate-level waste. Preliminary safety assessment

    International Nuclear Information System (INIS)

    1999-11-01

    A preliminary safety assessment has been performed of a deep repository for long-lived low- and intermediate-level waste, SFL 3-5. The purpose of the study is to investigate the capacity of the facility to act as a barrier to the release of radionuclides and toxic pollutants, and to shed light on the importance of the location of the repository site. A safety assessment (SR 97) of a deep repository for spent fuel has been carried out at the same time. In SR 97, three hypothetical repository sites have been selected for study. These sites exhibit fairly different conditions in terms of hydrogeology, hydrochemistry and ecosystems. To make use of information and data from the SR 97 study, we have assumed that SFL 3-5 is co-sited with the deep repository for spent fuel. A conceivable alternative is to site SFL 3-5 as a completely separate repository. The focus of the SFL 3-5 study is a quantitative analysis of the environmental impact for a reference scenario, while other scenarios are discussed and analyzed in more general terms. Migration in the repository's near- and far-field has been taken into account in the reference scenario. Environmental impact on the three sites has also been calculated. The calculations are based on an updated forecast of the waste to be disposed of in SFL 3-5. The forecast includes radionuclide content, toxic metals and other substances that have a bearing on a safety assessment. The safety assessment shows how important the site is for safety. Two factors stand out as being particularly important: the water flow at the depth in the rock where the repository is built, and the ecosystem in the areas on the ground surface where releases may take place in the future. Another conclusion is that radionuclides that are highly mobile and long-lived, such as 36 Cl and 93 Mo , are important to take into consideration. Their being long-lived means that barriers and the ecosystems must be regarded with a very long time horizon

  1. Deep repository for long-lived low- and intermediate-level waste. Preliminary safety assessment

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-11-01

    A preliminary safety assessment has been performed of a deep repository for long-lived low- and intermediate-level waste, SFL 3-5. The purpose of the study is to investigate the capacity of the facility to act as a barrier to the release of radionuclides and toxic pollutants, and to shed light on the importance of the location of the repository site. A safety assessment (SR 97) of a deep repository for spent fuel has been carried out at the same time. In SR 97, three hypothetical repository sites have been selected for study. These sites exhibit fairly different conditions in terms of hydrogeology, hydrochemistry and ecosystems. To make use of information and data from the SR 97 study, we have assumed that SFL 3-5 is co-sited with the deep repository for spent fuel. A conceivable alternative is to site SFL 3-5 as a completely separate repository. The focus of the SFL 3-5 study is a quantitative analysis of the environmental impact for a reference scenario, while other scenarios are discussed and analyzed in more general terms. Migration in the repository's near- and far-field has been taken into account in the reference scenario. Environmental impact on the three sites has also been calculated. The calculations are based on an updated forecast of the waste to be disposed of in SFL 3-5. The forecast includes radionuclide content, toxic metals and other substances that have a bearing on a safety assessment. The safety assessment shows how important the site is for safety. Two factors stand out as being particularly important: the water flow at the depth in the rock where the repository is built, and the ecosystem in the areas on the ground surface where releases may take place in the future. Another conclusion is that radionuclides that are highly mobile and long-lived, such as {sup 36}Cl and {sup 93}Mo , are important to take into consideration. Their being long-lived means that barriers and the ecosystems must be regarded with a very long time horizon.

  2. Effects of earthquakes on the deep repository for spent fuel in Sweden based on case studies and preliminary model results

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Munier, Raymond

    2002-06-01

    their original values within a few months. The density of the buffer around the canister is high enough to prevent liquefaction due to shaking. The predominant brittle deformation of a rock mass will be reactivation of pre- existing fractures. The ata emanating from faults intersecting tunnels show that creation of new fractures is confined to the immediate vicinity of the reactivated faults and that deformation in host rock is rapidly decreasing with the distance from the fault. By selection of appropriate respect distances the probability of canister damage due to faulting is further lowered. Data from deep South African mines show that rocks in a environment with non- existing faults and with low fracture densities and high stresses might generate faults in a previously unfractured rock mass. The Swedish repository will be located in fractured bedrock, at intermediate depth, 400 - 700 m, where stresses are moderate. The conditions to create these peculiar mining-induced features will not prevail in the repository environment. Should these faults anyhow be created, the canister is designed to withstand a shear deformation of at least 0.1 m. This corresponds to a magnitude 6 earthquake along the fault with a length of at least 1 km which is highly unlikely. Respect distance has to be site and fault specific. Field evidence gathered in this study indicates that respect distances may be considerably smaller (tens to hundreds of m) than predicted by numerical modelling (thousands of m). However, the accumulated deformation during repeated, future seismic event has to be accounted for

  3. Site investigations for repositories for solid radioactive wastes in deep continental geological formations

    International Nuclear Information System (INIS)

    1982-01-01

    This report reviews the earth-science investigations and associated scientific studies that may be needed to select a repository site and confirm that its characteristics are such that it will provide a safe confinement for solidified high-level and alpha-bearing and certain other solid radioactive wastes. Site investigations, as used in this report, cover earth sciences and associated safety analyses. Other site-investigation activities are identified but not otherwise considered here. The repositories under consideration are those consisting of mined cavities in deep continental rocks for accepting wastes in the solid and packaged form. The term deep as used in this report is used solely to emphasize the distinction between the repositories discussed in this report and those for shallow-ground disposal. In general, depths under consideration here are greater than 200 metres. The term continental refers to those geological formations that occur either beneath present-day land masses and adjoining islands or beneath the shallow seas. One of the objectives of site investigations is to collect the site-specific data necessary for the different evaluations, such as modelling required to assess the long-term safety of an underground repository

  4. Site investigations for repositories for solid radioactive wastes in deep continental geological formations

    Energy Technology Data Exchange (ETDEWEB)

    1982-01-01

    This report reviews the earth-science investigations and associated scientific studies that may be needed to select a repository site and confirm that its characteristics are such that it will provide a safe confinement for solidified high-level and alpha-bearing and certain other solid radioactive wastes. Site investigations, as used in this report, cover earth sciences and associated safety analyses. Other site-investigation activities are identified but not otherwise considered here. The repositories under consideration are those consisting of mined cavities in deep continental rocks for accepting wastes in the solid and packaged form. The term deep as used in this report is used solely to emphasize the distinction between the repositories discussed in this report and those for shallow-ground disposal. In general, depths under consideration here are greater than 200 metres. The term continental refers to those geological formations that occur either beneath present-day land masses and adjoining islands or beneath the shallow seas. One of the objectives of site investigations is to collect the site-specific data necessary for the different evaluations, such as modelling required to assess the long-term safety of an underground repository.

  5. Feasibility study for siting of a deep repository within the Malaa municipality

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1996-03-01

    Factors of importance for localizing a deep nuclear waste repository at Malaa in northern Sweden are analyzed in this study. The geologic structures of the area have been reviewed, using mostly data from published studies. Existing infrastructure and necessary improvements are discussed, as well as land use, environment, employment and other social effects. (This report is almost identical to the report NEI-SE--222, referred to in INIS 27:12 (AN: 27-040802)). 47 refs, 41 figs, 8 tabs.

  6. Feasibility study for siting of a deep repository within the Malaa municipality

    International Nuclear Information System (INIS)

    1996-03-01

    Factors of importance for localizing a deep nuclear waste repository at Malaa in northern Sweden are analyzed in this study. The geologic structures of the area have been reviewed, using mostly data from published studies. Existing infrastructure and necessary improvements are discussed, as well as land use, environment, employment and other social effects. (This report is almost identical to the report NEI-SE--222, referred to in INIS 27:12 (AN: 27-040802))

  7. Hydrologic Monitoring in the Deep Subsurface to Support Repository Performance

    Science.gov (United States)

    Hubbell, J. M.; Heath, G. L.; Scott, C. L.

    2007-12-01

    access, automatic data quality checks with notification, processing, and presentation of the data in real time through the web. The systems can be designed to manipulate/test the system remotely. Data from several sites will be presented showing that continuous monitoring is necessary to detect rapid changes in the deep vadose zone and ground water at fractured rock sites.

  8. Effects of earthquakes on the deep repository for spent fuel in Sweden based on case studies and preliminary model results

    Energy Technology Data Exchange (ETDEWEB)

    Baeckblom, Goeran [Conrox, Djursholm (Sweden); Munier, Raymond [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    2002-06-01

    return to their original values within a few months. The density of the buffer around the canister is high enough to prevent liquefaction due to shaking. The predominant brittle deformation of a rock mass will be reactivation of pre- existing fractures. The ata emanating from faults intersecting tunnels show that creation of new fractures is confined to the immediate vicinity of the reactivated faults and that deformation in host rock is rapidly decreasing with the distance from the fault. By selection of appropriate respect distances the probability of canister damage due to faulting is further lowered. Data from deep South African mines show that rocks in a environment with non- existing faults and with low fracture densities and high stresses might generate faults in a previously unfractured rock mass. The Swedish repository will be located in fractured bedrock, at intermediate depth, 400 - 700 m, where stresses are moderate. (abstract truncated)

  9. Modelling of radionuclide transport along the underground access structures of deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Poller, A. [National Cooperative for the Disposal of Radioactive Waste (NAGRA), Wettingen (Switzerland); Smith, P. [SAM Switzerland GmbH, Zuerich (Switzerland); Mayer, G.; Hayek, M. [AF-Consult Switzerland AG, Baden (Switzerland)

    2014-08-15

    The arrangement and sealing of the access routes to a deep geological repository for radioactive waste should ensure that any radionuclide release from the emplacement rooms during the post closure phase does not by-pass the geological barriers of the repository system to a significant extent. The base case of the present study, where realistic values for the hydraulic properties of the seals and the associated excavation damage zones were assumed, assesses to what extent this is actually the case for different layout variants (ramp and shaft access and shaft access only). Furthermore, as a test of robustness of system performance against uncertainties related to such seals and the associated excavation damage zones, the present study also considers a broad spectrum of calculation cases including the hypothetical possibility that the seals perform much more poorly than expected and to check whether, consequently, the repository tunnel system and the access structures may provide significant release pathways. The study considers a generic repository system for high-level waste (HLW repository) and for low- and intermediate-level waste (L/ILW repository), both with Opalinus Clay as the host rock. It also considers the alternative possibilities of a ramp or a shaft as the access route for material transport (waste packages, etc.) to the underground facilities. Additional shafts, e.g. for the transport of persons and for ventilation, are included in both cases. The overall modelling approach consists of three broad steps: (a) the network of tunnels and access structures is implemented in a flow model, which serves to calculate water flow rates along the tunnels and through the host rock; (b) all relevant transport paths are implemented in a radionuclide release and transport model, the water flow rates being obtained from the preceding flow model calculations; (c) individual effective dose rates arising from the radionuclides released from the considered repository

  10. Production, consumption and transport of gases in deep geological repositories according to the Swiss disposal concept

    International Nuclear Information System (INIS)

    Diomidis, N; Cloet, V.; Leupin, O.X.; Marschall, P.; Poller, A.; Stein, M.

    2016-12-01

    In a deep geological repository for radioactive waste, in absence of oxygen and in presence of water, corrosion of various metals and alloys will lead to the formation of hydrogen. If present, organic materials may slowly degrade and generate carbon dioxide, methane and other gaseous species. Depending on local conditions, gaseous species can be consumed by chemical reactions and by microbial activity. If the resulting rate of gas generation exceeds the rate of migration of dissolved gas molecules in the pores of the engineered barriers or the host rock, the solubility limit of the gas will eventually be exceeded and the formation of a discrete gas phase will occur. Gases could continue to accumulate until the pressure becomes sufficient to be released in gaseous form. This report deals with the evolution of gas-related processes that can influence the long-term behaviour and safety of low- and intermediate-level waste (L/ILW) and high-level waste (HLW) repositories in Opalinus Clay. The main aim is to present a synthesis of processes and phenomena related to repository-produced gases and to assess their influence on repository performance. A current overview of gas sources, reactions and interactions, generation, consumption, and transport is provided. Furthermore, current scientific understanding is used to define safety function indicators and criteria, which are employed to evaluate the potential influence of repository-generated gas on safety-relevant properties of engineered and natural barriers. The assessment of gas generation, consumption and transport is addressed separately for the HLW and the L/ILW deep geological repositories. The employed methodology, which is common for both repository types, consists of the description and quantification of the potential gas sources, which include the waste, barrier components such as disposal canisters and other gas-generating repository components, and of the processes and reactions leading to the generation or

  11. Production, consumption and transport of gases in deep geological repositories according to the Swiss disposal concept

    Energy Technology Data Exchange (ETDEWEB)

    Diomidis, N; Cloet, V.; Leupin, O.X.; Marschall, P.; Poller, A.; Stein, M.

    2016-12-15

    In a deep geological repository for radioactive waste, in absence of oxygen and in presence of water, corrosion of various metals and alloys will lead to the formation of hydrogen. If present, organic materials may slowly degrade and generate carbon dioxide, methane and other gaseous species. Depending on local conditions, gaseous species can be consumed by chemical reactions and by microbial activity. If the resulting rate of gas generation exceeds the rate of migration of dissolved gas molecules in the pores of the engineered barriers or the host rock, the solubility limit of the gas will eventually be exceeded and the formation of a discrete gas phase will occur. Gases could continue to accumulate until the pressure becomes sufficient to be released in gaseous form. This report deals with the evolution of gas-related processes that can influence the long-term behaviour and safety of low- and intermediate-level waste (L/ILW) and high-level waste (HLW) repositories in Opalinus Clay. The main aim is to present a synthesis of processes and phenomena related to repository-produced gases and to assess their influence on repository performance. A current overview of gas sources, reactions and interactions, generation, consumption, and transport is provided. Furthermore, current scientific understanding is used to define safety function indicators and criteria, which are employed to evaluate the potential influence of repository-generated gas on safety-relevant properties of engineered and natural barriers. The assessment of gas generation, consumption and transport is addressed separately for the HLW and the L/ILW deep geological repositories. The employed methodology, which is common for both repository types, consists of the description and quantification of the potential gas sources, which include the waste, barrier components such as disposal canisters and other gas-generating repository components, and of the processes and reactions leading to the generation or

  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. Review. Deep repository for spent nuclear fuel SR 97 - Post-closure safety

    International Nuclear Information System (INIS)

    Stephansson, Ove

    2000-01-01

    SKB states that the chosen scenarios provide good coverage of future evolutionary pathways for the deep repository. This is not the case. SKB has not made full use of the established interaction matrices and the new method of THMC diagrams to generate the relevant and important scenarios and to construct the important pathways of variables and processes, either in the established interaction matrices and the presented THMC diagrams. Hence, SKB is demonstrating in SR 97 that they lack a well thought through, sound and solid method to select and evaluate scenarios for the purpose of demonstrating the safety of a deep repository for spent nuclear fuel. The evolution of the system is presented for the components of the repository system (fuel, canister, buffer/backfill, geosphere) and the effects of four different scenarios, but time only enters into the system for discrete events or processes, e.g. description of the relative radiotoxicity and heat decay of the fuel, temperature distribution, iron exchange process, pH in buffer, redox capacity and radionuclear release at the three sites. There is a lack of method and way of describing the evolution of the complete repository system, including the major scenarios, as a function of time. It is essential that SKB is able to: - consider the full range of potential scenarios, - grade the scenarios according to their significance for repository design and performance and safety assessment, - consider whether simple engineering actions could be taken to inhibit the development of adverse scenarios. This cannot be done with the system presented in SR 97, and so SKB do not have a full predictive capability - which is required for the engineering design of such an important and costly structure as a repository. Geoscientific investigation material for three selected sites are presented by SKB in the technical report dealing with waste, repository design and sites. Here a general overview is missing of the geological and rock

  15. Confidence in the long-term safety of deep geological repositories. Its development and communication

    International Nuclear Information System (INIS)

    1999-01-01

    The technical aspects of confidence have been the subject of considerable debate, especially the concept of model validation. The safety case that is provided at a particular stage in the planning, construction, operation or closure of a deep geological repository is a part of a broader decision basis that guides the repository-development process. The basic steps for deriving the safety case at various stages of repository development involve: a safety assessment; and the documentation of the safety assessment, a statement of confidence in the safety indicated by the assessment, and the confirmation of the appropriateness of the safety strategy. The approaches to establish confidence in the evaluation of safety should aim to ensure that the decisions taken within the incremental process of repository development are well-founded. Various aspects of confidence in the evaluation of safety, and their integration within a safety case, are presented in detail in the present report. When communicating confidence in the findings of a safety assessment, clarity in the communication of concepts is always required. Consistent with this requirement, key concepts are specifically defined in the main text of the report. (R.P.)

  16. Demonstrating the sealing of a deep geologic repository: the RECAP project

    International Nuclear Information System (INIS)

    Kuzyk, G.W.; Dixon, D.A.; Martino, J.B.; Kozak, E.T.; Bilinsky, D.M.; Thompson, P.M.

    2006-01-01

    Atomic Energy of Canada Limited (AECL) has operated an Underground Research Laboratory (URL) for twenty-three years (1982-2005). The URL was designed and constructed to carry out in situ geotechnical R and D needed for the Canadian Nuclear Fuel Waste Management program. The facility is now being closed, the final of several phases that have included siting, site evaluation, construction and operation. The closure phase presents a unique opportunity to develop and demonstrate the methodologies needed for closure and site restoration of a deep geologic repository for used nuclear fuel. A wealth of technical background and characterization data, dating back to before the first excavation work was carried out, are available to support closure activities. A number of closure-related activities are being proposed as part of a REpository Closure And Post-closure (RECAP) project. The RECAP project is proposed to include demonstrations of shaft and borehole sealing and monitoring as well as fracture sealing (grouting), room closure and monitoring system decommissioning, all activities that would occur when closing an actual repository. In addition to the closure-related activities, the RECAP project could provide a unique opportunity to conduct intrusion-monitoring demonstrations as part of a repository safeguards demonstration. (author)

  17. Modelling of far-field gas migration from a deep radioactive waste repository

    International Nuclear Information System (INIS)

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

    1992-01-01

    In assessing the post-closure safety of a deep radioactive waste repository, it is necessary to show that gas generated within the repository can migrate away, through the far-field geology, without affecting repository safety. This paper discusses the contribution of various mechanisms to gas migration through the far field; for example, diffusion of dissolved gas versus gas-phase movement, and bubble flow versus formation of a connected gas stream. It outlines different approaches to modelling gas movement from a repository, with simple semi-analytical models furnishing physical insights into the factors controlling gas migration in the absence of directly applicable experimental data, and more comprehensive numerical computations allowing the exploration of more detailed behaviour when appropriate data is obtained. If gas can induce groundwater movement, this could accelerate the transport of water-borne contaminants. Processes by which this could occur are noted, and the current status of work on possible effects of gas migration on groundwater movement in fractured hard rocks is indicated. 14 refs., 4 figs

  18. An overview on the national strategy to implement a deep geological repository in Romania

    International Nuclear Information System (INIS)

    Negut, G.; Ghitescu, P.; Dupleac, D.; Prisecaru, I.

    2010-01-01

    Since 1996 in Romania was started operation Candu 700 MW Unit 1 Cernavoda Nuclear Power Station and in 2007 begun operation of the Candu 700 MW Unit 2. The energy produced by nuclear units is accompanied by radioactive waste production. According with European Union requirements in Romania was created National Agency for Radioactive Waste (ANDRAD) in 2003. ANDRAD business is radioactive waste management. ANDRAD, together with the stakeholders, worked the law of great radioactive waste generators contribution for radioactive waste management, which was approved by Governmental Ordinance in September 2007. ANDRAD is responsible manager of this fund. ANDRAD is responsible, also, with the National Strategy for radioactive waste management. Romania's National Strategy for Energy approved in 2007 by Government Ordinance says that a deep geological repository for spent fuel (SF) and High Level Waste (HLW) is to be put in operation around 2055. IAEA supported ANDRAD in a Technical Cooperation Project for a concept of a geological repository of radioactive waste. A strategy to implement o geological repository in Romania was drafted. There are problems with potential rocks and sites to host a geological repository. There are problems for funding this project and also sensitive and serious problems connected with social and political issues. Paper presents this strategy and all the problems arisen by implantation of this strategy. (authors)

  19. A THM stress-strain framework for modelling the performance of argillaceous materials in deep repositories for radioactive waste

    International Nuclear Information System (INIS)

    Laloui, L.; Francois, B.

    2007-01-01

    In the scenarios for deep, geological nuclear-waste repositories, clayey soils will be hydrated, heated, cooled and dried. The numerical modelling of these mechanical processes is a key issue. Performance assessment of deep repositories for heat-generating radioactive waste would benefit from improvements in mechanical stress-strain constitutive modelling of the coupled thermo-hydro-mechanical behaviour. The presented framework allows progress in understanding the most involved phenomena relevant to nuclear-waste repositories and their coupled nature. It could be used both in the design and in the performance assessment of repositories. It may be applied to disposal in clay formations and to hard-rock repositories where artificially compacted clay is to be used as buffer and backfill. Such a constitutive framework may help in understanding some unexplained or controversial behaviours and in defining experimental programmes to answer key questions. (author)

  20. Potential effects of bacteria on radionuclide transport from a Swedish high level nuclear waste repository

    International Nuclear Information System (INIS)

    Pedersen, K.

    1990-01-01

    Microorganisms can influence radionuclide migration if their concentration are high in comparison with other organic particles. Data on the numbers of microorganisms in undisturbed ground-water have been collected. The average number of cells in the samples from 17 levels in 5 boreholes was 3.0 x 10 5 cells ml -1 . A biofilm experiment indicated an active microbial rock surface population. Radiographic uptake experiments suggest inactive bulk water populations. The bulk water microbial cells in deep ground water might then be inactive cells detached from active biofilms. Enrichment cultures for anaerobic bacteria demonstrated the presence of anaerobic bacteria capable of growth on C-1 compounds with hydrogen and carbon dioxide, presumably methanogenic bacteria. Further, growth in enrichment cultures with sulphate as electron-acceptor and lactate as carbon source proved dissimilatory sulphate reducing bacteria to be present. (author)

  1. Diffusion Dominant Solute Transport Modelling In Deep Repository Under The Effect of Emplacement Media Degradation - 13285

    International Nuclear Information System (INIS)

    Kwong, S.; Jivkov, A.P.

    2013-01-01

    Deep geologic disposal of high activity and long-lived radioactive waste is being actively considered and pursued in many countries, where low permeability geological formations are used to provide long term waste contaminant with minimum impact to the environment and risk to the biosphere. A multi-barrier approach that makes use of both engineered and natural barriers (i.e. geological formations) is often used to further enhance the containment performance of the repository. As the deep repository system subjects to a variety of thermo-hydro-chemo-mechanical (THCM) effects over its long 'operational' lifespan (e.g. 0.1 to 1.0 million years, the integrity of the barrier system will decrease over time (e.g. fracturing in rock or clay)). This is broadly referred as media degradation in the present study. This modelling study examines the effects of media degradation on diffusion dominant solute transport in fractured media that are typical of deep geological environment. In particular, reactive solute transport through fractured media is studied using a 2-D model, that considers advection and diffusion, to explore the coupled effects of kinetic and equilibrium chemical processes, while the effects of degradation is studied using a pore network model that considers the media diffusivity and network changes. Model results are presented to demonstrate the use of a 3D pore-network model, using a novel architecture, to calculate macroscopic properties of the medium such as diffusivity, subject to pore space changes as the media degrade. Results from a reactive transport model of a representative geological waste disposal package are also presented to demonstrate the effect of media property change on the solute migration behaviour, illustrating the complex interplay between kinetic biogeochemical processes and diffusion dominant transport. The initial modelling results demonstrate the feasibility of a coupled modelling approach (using pore-network model and reactive

  2. 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)

  3. OPG's deep geologic repository for low and intermediate level waste - recent progress

    International Nuclear Information System (INIS)

    King, F.K.

    2006-01-01

    This paper provides a status report on Canada's first project to build a permanent repository for the long-term management of radioactive waste. Ontario Power Generation has initiated a project to construct a deep geologic repository for low- and intermediate-level waste at the Bruce Nuclear Site, at a depth in the range of 600 to 800 m in an Ordovician-age argillaceous limestone formation. The project is currently undergoing an Environmental Assessment and consulting companies in the areas of environmental assessment, geoscientific site characterization, engineering and safety assessment have been hired and technical studies are underway. Seismic surveys and borehole drilling will be initiated in the fall of 2006. The next major milestone for the project is the submission of the Environmental Assessment report, currently scheduled for December 2008. (author)

  4. Postclosure safety assessment of a deep geological repository for Canada's used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hunt, N.G.; Kremer, E.P.; Garisto, F.; Gierszewski, P.; Gobien, M.; Medri, C.L.D. [Nuclear Waste Management Organization, Toronto, ON (Canada); Avis, J.D. [Geofirma Engineering Ltd., Ottawa, ON (Canada); Chshyolkova, T.; Kitson, C.I.; Melnyk, W.; Wojciechowski, L.C. [Atomic Energy of Canada Limited, Pinawa, MB (Canada)

    2011-07-01

    This paper reports on elements of a postclosure safety assessment performed for a conceptual design and hypothetical site for a deep geological repository for Canada's used nuclear fuel. Key features are the assumption of a copper used fuel container with a steel inner vessel, container placement in vertical in-floor boreholes, a repository depth of 500 m, and a sparsely fractured crystalline rock geosphere. The study considers a Normal Evolution Scenario together with a series of Disruptive Event Scenarios. The Normal Evolution Scenario is a reasonable extrapolation of present day site features and receptor lifestyles, while the Disruptive Event Scenarios examine abnormal and unlikely failures of the containment and isolation systems. Both deterministic and probabilistic simulations were performed. The results show the peak dose consequences occur far in the future and are well below the applicable regulatory acceptance criteria and the natural background levels. (author)

  5. Hydrogen transfer experiments and modelization in clay rocks for radioactive waste deep geological repository

    International Nuclear Information System (INIS)

    Boulin, P.

    2008-10-01

    Gases will be generated by corrosion of high radioactive waste containers in deep geological repositories. A gas phase will be generated. Gas pressure will build up and penetrated the geological formation. If gases do not penetrate the geological barrier efficiently, the pressure build up may create a risk of fracturing and of creation of preferential pathways for radionuclide migration. The present work focuses on Callovo-Oxfordian argillites characterisation. An experiment, designed to measure very low permeabilities, was used with hydrogen/helium and analysed using the Dusty Gas Model. Argillites close to saturation have an accessible porosity to gas transfer that is lower than 0,1% to 1% of the porosity. Analysis of the Knudsen effect suggests that this accessible network should be made of 50 nm to 200 nm diameter pores. The permeabilities values were integrated to an ANDRA operating model. The model showed that the maximum pressure expected near the repository would be 83 bar. (author)

  6. Gas cooled reactor decommissioning. Packaging of waste for disposal in the United Kingdom deep repository

    International Nuclear Information System (INIS)

    Barlow, S.V.; Wisbey, S.J.; Wood, P.

    1998-01-01

    United Kingdom Nirex Limited has been established to develop and operate a deep underground repository for the disposal of the UK's intermediate and certain low level radioactive waste. The UK has a significant Gas Cooled Reactor (GCR) programme, including both Magnox and AGR (Advanced Gas-cooled Reactor) capacity, amounting to 26 Magnox reactors, 15 AGR reactors as well as research and prototype reactor units such as the Windscale AGR and the Windscale Piles. Some of these units are already undergoing decommissioning and Nirex has estimated that some 15,000 m 3 (conditioned volume) will come forward for disposal from GCR decommissioning before 2060. This volume does not include final stage (Stage 3) decommissioning arisings from commercial reactors since the generating utilities in the UK are proposing to adopt a deferred safe store strategy for these units. Intermediate level wastes arising from GCR decommissioning needs to be packaged in a form suitable for on-site interim storage and eventual deep disposal in the planned repository. In the absence of Conditions for Acceptance for a repository in the UK, the dimensions, key features and minimum performance requirements for waste packages are defined in Waste Package Specifications. These form the basis for all assessments of the suitability of wastes for disposal, including GCR wastes. This paper will describe the nature and characteristics of GCR decommissioning wastes which are intended for disposal in a UK repository. The Nirex Waste Package Specifications and the key technical issues, which have been identified when considering GCR decommissioning waste against the performance requirements within the specifications, are discussed. (author)

  7. Review. Deep repository for spent nuclear fuel SR 97 - Post-closure safety

    Energy Technology Data Exchange (ETDEWEB)

    Stephansson, Ove [Royal Inst. of Tech., Stockholm (Sweden). Dept. of Civil and Environmental Engineering

    2000-12-01

    SKB states that the chosen scenarios provide good coverage of future evolutionary pathways for the deep repository. This is not the case. SKB has not made full use of the established interaction matrices and the new method of THMC diagrams to generate the relevant and important scenarios and to construct the important pathways of variables and processes, either in the established interaction matrices and the presented THMC diagrams. Hence, SKB is demonstrating in SR 97 that they lack a well thought through, sound and solid method to select and evaluate scenarios for the purpose of demonstrating the safety of a deep repository for spent nuclear fuel. The evolution of the system is presented for the components of the repository system (fuel, canister, buffer/backfill, geosphere) and the effects of four different scenarios, but time only enters into the system for discrete events or processes, e.g. description of the relative radiotoxicity and heat decay of the fuel, temperature distribution, iron exchange process, pH in buffer, redox capacity and radionuclear release at the three sites. There is a lack of method and way of describing the evolution of the complete repository system, including the major scenarios, as a function of time. It is essential that SKB is able to: - consider the full range of potential scenarios, - grade the scenarios according to their significance for repository design and performance and safety assessment, - consider whether simple engineering actions could be taken to inhibit the development of adverse scenarios. This cannot be done with the system presented in SR 97, and so SKB do not have a full predictive capability - which is required for the engineering design of such an important and costly structure as a repository. Geoscientific investigation material for three selected sites are presented by SKB in the technical report dealing with waste, repository design and sites. Here a general overview is missing of the geological and rock

  8. Generic description of facilities at the shaft head (auxiliary entrance installations) of deep geological repositories

    International Nuclear Information System (INIS)

    2016-10-01

    In a deep geological repository, the access structures function as the link between the surface and the installations and structures at the disposal level. In the planned implementation scenarios, at least two access structures will be in operation up to the time of closure of the repository. The radioactive waste will be transported via the main access from the surface to the disposal level during emplacement operations. For the construction and operation of a deep geological repository, additional access structures are required. These auxiliary accesses and the associated surface infrastructure (e.g. shaft head installations) form the subject of this report. To provide as broad and comprehensive a description as possible, seven types of auxiliary access facilities are defined; these are characterised in line with the current status of planning and their functions and impacts are described. During construction, operation and dismantling of auxiliary access facilities, the usual conventional safety measures (inter alia) have to be observed (e.g. groundwater protection, fire prevention, facility security, accident prevention). Regarding the 'Ordinance on Protection against Major Accidents' no large quantities of hazardous materials, i.e. above the corresponding threshold quantities, are to be expected in the auxiliary access facilities. Proper handling and compliance with applicable regulations in all phases will ensure no hazard to humans and the environment. As no handling of radioactive materials is foreseen in the auxiliary access facilities, and because exhaust air and waste water from the controlled zones of a repository will, in principle, be removed via the main access and not the auxiliary accesses, a safety-relevant emission of radioactive substances and transport of contaminated material can be ruled out for the auxiliary access facilities during both normal operation and also in the case of an accident. Based on the information presented in

  9. Feasibility study for siting of a deep repository within the Storuman municipality

    International Nuclear Information System (INIS)

    1995-01-01

    It is SKB's task to gather a broad body of information for the siting of a deep repository for Sweden's spent nuclear fuel and other long-lived radioactive waste. The criteria presented by SKB serve as guidelines for the siting studies. Overviews of siting factors are compiled in general siting studies of all or parts of Sweden. Feasibility studies examine the siting prospects in potentially suitable and interested municipalities. SKB plans to carry out feasibility studies in five to ten municipalities in different parts of the country. General studies and feasibility studies are primarily based on existing material. The feasibility study in Storuman is the first to be conducted. It began during the second half of 1993 with the conclusion of an agreement between the municipality and SKB. SKB has been in charge of the execution of the feasibility study. SKB has been responsible for the summary provided in a status report published in June 1994, as well as for the conclusions and evaluations in this final report. Altogether about 30 reports have been published within the framework of the feasibility study. The purpose of the various studies have been to describe, in as much detail as possible, the prospects for siting a deep repository in the municipality of Storuman, and to shed light on the possible positive and negative consequences of such a siting. The feasibility study has led to a discussion within the municipality and the region concerning the siting of a deep repository. In SKB's opinion, this gives all those concerned ample opportunity to become acquainted with the issues and to assert their interests and present their viewpoints at an early stage. 55 refs

  10. Feasibility study for siting of a deep repository within the Storuman municipality

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-01-01

    It is SKB`s task to gather a broad body of information for the siting of a deep repository for Sweden`s spent nuclear fuel and other long-lived radioactive waste. The criteria presented by SKB serve as guidelines for the siting studies. Overviews of siting factors are compiled in general siting studies of all or parts of Sweden. Feasibility studies examine the siting prospects in potentially suitable and interested municipalities. SKB plans to carry out feasibility studies in five to ten municipalities in different parts of the country. General studies and feasibility studies are primarily based on existing material. The feasibility study in Storuman is the first to be conducted. It began during the second half of 1993 with the conclusion of an agreement between the municipality and SKB. SKB has been in charge of the execution of the feasibility study. SKB has been responsible for the summary provided in a status report published in June 1994, as well as for the conclusions and evaluations in this final report. Altogether about 30 reports have been published within the framework of the feasibility study. The purpose of the various studies have been to describe, in as much detail as possible, the prospects for siting a deep repository in the municipality of Storuman, and to shed light on the possible positive and negative consequences of such a siting. The feasibility study has led to a discussion within the municipality and the region concerning the siting of a deep repository. In SKB`s opinion, this gives all those concerned ample opportunity to become acquainted with the issues and to assert their interests and present their viewpoints at an early stage. 55 refs.

  11. Simulating Earthquake Rupture and Off-Fault Fracture Response: Application to the Safety Assessment of the Swedish Nuclear Waste Repository

    KAUST Repository

    Falth, B.

    2014-12-09

    To assess the long-term safety of a deep repository of spent nuclear fuel, upper bound estimates of seismically induced secondary fracture shear displacements are needed. For this purpose, we analyze a model including an earthquake fault, which is surrounded by a number of smaller discontinuities representing fractures on which secondary displacements may be induced. Initial stresses are applied and a rupture is initiated at a predefined hypocenter and propagated at a specified rupture speed. During rupture we monitor shear displacements taking place on the nearby fracture planes in response to static as well as dynamic effects. As a numerical tool, we use the 3Dimensional Distinct Element Code (3DEC) because it has the capability to handle numerous discontinuities with different orientations and at different locations simultaneously. In tests performed to benchmark the capability of our method to generate and propagate seismic waves, 3DEC generates results in good agreement with results from both Stokes solution and the Compsyn code package. In a preliminary application of our method to the nuclear waste repository site at Forsmark, southern Sweden, we assume end-glacial stress conditions and rupture on a shallow, gently dipping, highly prestressed fault with low residual strength. The rupture generates nearly complete stress drop and an M-w 5.6 event on the 12 km(2) rupture area. Of the 1584 secondary fractures (150 m radius), with a wide range of orientations and locations relative to the fault, a majority move less than 5 mm. The maximum shear displacement is some tens of millimeters at 200 m fault-fracture distance.

  12. Canada's deep geological repository for used nuclear fuel - site selection process update

    International Nuclear Information System (INIS)

    Facella, J.

    2014-01-01

    In 2007, the Government of Canada selected Adaptive Phased Management as Canada's plan for the long-term management of Canada's used nuclear fuel in a deep geological repository, located in an informed and willing host. The process of site selection is an important milestone in this program. The NWMO describes its approach to working collaboratively with communities which expressed interest in exploring the project, as well as Aboriginal communities in the area and other surrounding communities. The project is designed to be implemented through a long-term partnership involving the interested community, Aboriginal communities and surrounding communities working with the NWMO. (author)

  13. Geoscientific programme for investigation and evaluation of sites for the deep repository

    International Nuclear Information System (INIS)

    2000-08-01

    SKB's goal is to be able to commence site investigations in 2002. Extensive preparations are now being made for this transition to the next phase in the siting process for the deep repository. This report describes the investigation and evaluation programme, which is focused on a deep repository in accordance with the KBS-3 method for spent nuclear fuel. When areas for site investigations have been chosen, the programmes will be adapted to the site-specific conditions. The geoscientific work during the site investigation phase is supposed to provide the broad knowledge base that is required to evaluate the suitability of investigated sites for a deep repository. The material must be comprehensive enough to: show whether the selected site satisfies fundamental safety requirements; permit comparisons with other investigated sites; and serve as a basis for adaptation of the deep repository to the properties and characteristics of the site with an acceptable impact on society and the environment. The work is being carried out in consultation with municipalities, regulatory authorities and nearby residents. The main product of the investigations is a site description, which presents collected data and interpreted parameters that are of importance both for the overall scientific understanding of the site and for the analyses and assessments that are made of design and safety assessment with respect to the deep repository's layout and construction as well as its long-term performance and radiological safety. The site description should furthermore present an integrated description of the site (geosphere and biosphere) and its regional environs with respect to current state and naturally ongoing processes. A technical risk evaluation is carried out, by which is meant a description of uncertainties in calculations and the environmental impact of the civil engineering work. The main product of the safety assessment is a safety report, which analyzes whether long-term safety

  14. General siting study 95. Siting of a deep repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    1995-10-01

    General Siting Study 95 is a detailed description of the work carried out to put the siting of a deep repository in a national and regional context. The report is based on SKB's siting factors, which have been applied on a national scale. Different factors of importance or of possible importance for the long-term radiological safety, technology, land and environment as well as society are described and evaluated. This report is the overall description on general siting studies which the government considered that SKB should report in connection with the RD and D Programme 95. 121 refs, 40 figs

  15. 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

  16. Geoscientific programme for investigation and evaluation of sites for the deep repository

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-08-01

    SKB's goal is to be able to commence site investigations in 2002. Extensive preparations are now being made for this transition to the next phase in the siting process for the deep repository. This report describes the investigation and evaluation programme, which is focused on a deep repository in accordance with the KBS-3 method for spent nuclear fuel. When areas for site investigations have been chosen, the programmes will be adapted to the site-specific conditions. The geoscientific work during the site investigation phase is supposed to provide the broad knowledge base that is required to evaluate the suitability of investigated sites for a deep repository. The material must be comprehensive enough to: show whether the selected site satisfies fundamental safety requirements; permit comparisons with other investigated sites; and serve as a basis for adaptation of the deep repository to the properties and characteristics of the site with an acceptable impact on society and the environment. The work is being carried out in consultation with municipalities, regulatory authorities and nearby residents. The main product of the investigations is a site description, which presents collected data and interpreted parameters that are of importance both for the overall scientific understanding of the site and for the analyses and assessments that are made of design and safety assessment with respect to the deep repository's layout and construction as well as its long-term performance and radiological safety. The site description should furthermore present an integrated description of the site (geosphere and biosphere) and its regional environs with respect to current state and naturally ongoing processes. A technical risk evaluation is carried out, by which is meant a description of uncertainties in calculations and the environmental impact of the civil engineering work. The main product of the safety assessment is a safety report, which analyzes whether long

  17. General siting study 95. Siting of a deep repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    General Siting Study 95 is a detailed description of the work carried out to put the siting of a deep repository in a national and regional context. The report is based on SKB`s siting factors, which have been applied on a national scale. Different factors of importance or of possible importance for the long-term radiological safety, technology, land and environment as well as society are described and evaluated. This report is the overall description on general siting studies which the government considered that SKB should report in connection with the RD and D Programme 95. 121 refs, 40 figs.

  18. The Swedish Deep Drilling Program - an emerging scientific drilling program and new infrastructure.

    Science.gov (United States)

    Lorenz, Henning; Juhlin, Christopher

    2010-05-01

    Scientific drilling projects imply numerous aspects that are difficult to handle for individual research groups. Therefore, about three years ago a joint effort was launched in the Swedish geoscientific community to establish a national program for scientific drilling, the Swedish Deep Drilling Program (SDDP). Soon afterwards, several working groups established drilling proposals with Nordic and, also, international participation. With this serious interest in scientific drilling SDDP was able to successfully promote the Swedish membership in ICDP which commenced in 2008. Two SDDP projects achieved workshop grants from the International Continental Scientific Drilling Program (ICDP) in 2009. In the same year the Swedish Research Council decided to support an application for a truck-mounted drill rig - a big success for the SDDP working group. Scientific Drilling infrastructure: SDDP envisages a mobile platform that is capable of core drilling to at least 2500 m depth. The procurement will be made during 2010 and first operations are planned for 2011. This drill rig is primarily intended for use in the SDDP drilling projects, but will be rented out to other scientific drilling projects or even commercial enterprises in the remaining time to cover maintenance and future upgrade costs. SDDP's drill rig will be unique in Europe and complementary to the deep drilling InnovaRig of the GFZ German Research Centre for Geosciences. Until now, drilling to 2000 - 3000 m implied the use of a full-sized drill rig like the InnovaRig or the mobilization of a core drill rig from another continent. This gap will now be filled by Sweden's upcoming scientific drilling infrastructure. Drilling projects and proposals: Presently, SDDP serves six projects: "Collisional Orogeny in the Scandinavian Caledonides" (COSC; ICDP workshop spring 2010), the "Postglacial Fault Drilling Project" (PFDP; ICDP workshop autumn 2010), a "Deep Rock Laboratory" (DRL), "Palaeoproterozoic Mineralized Volcanic

  19. 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)

  20. The development of a deep repository-progress in the UK

    International Nuclear Information System (INIS)

    Beale, H.; Mogg, C.S.

    1992-01-01

    United Kingdom Nirex Ltd, a company jointly owned by the major partners in the UK nuclear industry, is responsible for developing a deep disposal facility for low-level and intermediate-level radioactive waste. In July 1991 Nirex announced its intention to concentrate geological investigations at Sellafield, where BNFL's existing operations give rise to approximately 60% of the wastes destined for a repository. The main features of the Nirex design process, from early considerations through the main features of a preferred conceptual design and its advantages, are described. Subject to Nirex obtaining planning permission, following a Public Inquiry, the proposed program would allow the UK nuclear industry to fulfill its responsibilities with respect to declared Government policy by providing a safe deep geological disposal facility early in the next century. (author)

  1. MODELING OF THE GROUNDWATER TRANSPORT AROUND A DEEP BOREHOLE NUCLEAR WASTE REPOSITORY

    Energy Technology Data Exchange (ETDEWEB)

    N. Lubchenko; M. Rodríguez-Buño; E.A. Bates; R. Podgorney; E. Baglietto; J. Buongiorno; M.J. Driscoll

    2015-04-01

    The concept of disposal of high-level nuclear waste in deep boreholes drilled into crystalline bedrock is gaining renewed interest and consideration as a viable mined repository alternative. A large amount of work on conceptual borehole design and preliminary performance assessment has been performed by researchers at MIT, Sandia National Laboratories, SKB (Sweden), and others. Much of this work relied on analytical derivations or, in a few cases, on weakly coupled models of heat, water, and radionuclide transport in the rock. Detailed numerical models are necessary to account for the large heterogeneity of properties (e.g., permeability and salinity vs. depth, diffusion coefficients, etc.) that would be observed at potential borehole disposal sites. A derivation of the FALCON code (Fracturing And Liquid CONvection) was used for the thermal-hydrologic modeling. This code solves the transport equations in porous media in a fully coupled way. The application leverages the flexibility and strengths of the MOOSE framework, developed by Idaho National Laboratory. The current version simulates heat, fluid, and chemical species transport in a fully coupled way allowing the rigorous evaluation of candidate repository site performance. This paper mostly focuses on the modeling of a deep borehole repository under realistic conditions, including modeling of a finite array of boreholes surrounded by undisturbed rock. The decay heat generated by the canisters diffuses into the host rock. Water heating can potentially lead to convection on the scale of thousands of years after the emplacement of the fuel. This convection is tightly coupled to the transport of the dissolved salt, which can suppress convection and reduce the release of the radioactive materials to the aquifer. The purpose of this work has been to evaluate the importance of the borehole array spacing and find the conditions under which convective transport can be ruled out as a radionuclide transport mechanism

  2. 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.

  3. Canada's Deep Geological Repository for Used Nuclear Fuel - Geo-scientific Site Evaluation Process - 13117

    International Nuclear Information System (INIS)

    Blyth, Alec; Ben Belfadhel, Mahrez; Hirschorn, Sarah; Hamilton, Duncan; McKelvie, Jennifer

    2013-01-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable rock formation at a depth of approximately 500 meters (m) (1,640 feet [ft]). In May 2010, the NWMO published a nine-step site selection process that serves as the road map to decision-making on the location for the deep geological repository. The safety and appropriateness of any potential site will be assessed against a number of factors, both technical and social in nature. The selected site will be one that can be demonstrated to be able to safely contain and isolate used nuclear fuel, protecting humans and the environment over the very long term. The geo-scientific suitability of potential candidate sites will be assessed in a stepwise manner following a progressive and thorough site evaluation process that addresses a series of geo-scientific factors revolving around five safety functions. The geo-scientific site evaluation process includes: Initial Screenings; Preliminary Assessments; and Detailed Site Evaluations. As of November 2012, 22 communities have entered the site selection process (three in northern Saskatchewan and 18 in northwestern and southwestern Ontario). (authors)

  4. Nuclear Waste Facing the Test of Time: The Case of the French Deep Geological Repository Project.

    Science.gov (United States)

    Poirot-Delpech, Sophie; Raineau, Laurence

    2016-12-01

    The purpose of this article is to consider the socio-anthropological issues raised by the deep geological repository project for high-level, long-lived nuclear waste. It is based on fieldwork at a candidate site for a deep storage project in eastern France, where an underground laboratory has been studying the feasibility of the project since 1999. A project of this nature, based on the possibility of very long containment (hundreds of thousands of years, if not longer), involves a singular form of time. By linking project performance to geology's very long timescale, the project attempts "jump" in time, focusing on a far distant future, without understanding it in terms of generations. But these future generations remain measurements of time on the surface, where the issue of remembering or forgetting the repository comes to the fore. The nuclear waste geological storage project raises questions that neither politicians nor scientists, nor civil society, have ever confronted before. This project attempts to address a problem that exists on a very long timescale, which involves our responsibility toward generations in the far future.

  5. Status and development of deep geological repository in Slovak republic from geological point of view

    Directory of Open Access Journals (Sweden)

    Jozef Franzen

    2007-01-01

    Full Text Available During the operation of Slovak NPPs, production of approximately 2,300 metric tons of spent fuel expressed as heavy metal (18,654 spent fuel assemblies is expected. In addition, about 5000 metric tons of radioactive waste unfit for near surface repository at Mochovce and destined for a deep geological disposal. The safe and long-term solution of back-end fuel cycle is so highly required.One of the most favorable solutions is Deep Geological Repository (DGR. The site for a DGR, along with repository design and the engineered barrier system must ensure long-term safety of the disposal system.A preliminary set of site-selection criteria for a DGR was proposed in Slovakia, based on worldwide experience and consistent with IAEA recommendations. Main groups of criteria are: 1 geological and tectonic stability of prospective sites; 2 appropriate characteristics of host rock (lithological homogeneity, suitable hydrogeological and geochemical conditions, favourable geotechnical setting, absence of mineral resources, etc.; 3 conflict of interests (natural resources, natural and cultural heritage, protected resources of thermal waters, etc..Based on the previous geological investigations, three distinct areas (five localities were determined as the most prospective sites for construction of a DGR so far. Three of them are built by granitoids rock (Tribeč Mts., Veporske vrchy Mts. and Stolicke vrchy Mts., other consist of sedimentary rock formations (Cerova vrchovina Upland and Rimavska kotlina Basin. Objective for the next investigation stage is to perform more detailed geological characterization of the prospective sites.

  6. SPRAYED CLAY TECHNOLOGY FOR THE DEEP REPOSITORY OF HIGH-LEVEL RADIOACTIVE WASTE

    Directory of Open Access Journals (Sweden)

    Lucie Hausmannová

    2012-07-01

    Full Text Available The sealing barrier will play very important role in the Czech disposal concept of high level radioactive waste. It follows Swedish SKB3 design where granitic rock environment will host the repository. Swelling clay based materials as the most favorable for sealing purposes were selected. Such clays must fulfill certain requirements (e.g. on swelling properties, hydraulic conductivity or plasticity and must be stable for thousands of years. Better sealing behavior is obtained when the clay is compacted. Technology of the seal construction can vary according to its target dry density. Very high dry density is needed for buffer (sealing around entire canister with radioactive waste. Less strict requirements are on material backfilling the access galleries. It allows compaction to lower dry density than in case of buffer. One of potential technology for backfilling is to compact clay layers in most of the gallery profile by common compaction machines (rollers etc. and to spray clay into the uppermost part afterwards. The paper introduces the research works on sprayed clay technology performed at the Centre of Experimental Geotechnics of the Czech Technical University in Prague. Large scale in situ demonstration of filling of short drift in the Josef Gallery is also mentioned.

  7. Use of petrophysical data for siting of deep geological repository of radioactive waste

    Science.gov (United States)

    Petrenko, Liliana; Shestopalov, Vyacheslav

    2017-11-01

    The paper is devoted to analyzing the petrophysical properties and petrographical characteristics of Volyn region with the view to choosing the least permeable and so the most suitable geological formation for the radioactive waste disposal. On a basis of the petrophysical estimations of the granitoids properties the argumentation of permeability has been developed for the petrotypes of Volyn region. Also method of classification of the petrotypes with their relative rate of suitability for radioactive waste disposal was developed. As a result of studying the perspectives were shown of the zhytomyr and korosten types of the granitoids as host rock for the radioactive waste disposal. According to the results of investigations performed by Swedish researchers a comparative analysis of rocks based on the age of formation, composition, structural features and some petrophysical properties of granitoids as host rocks for repository of radioactive waste was performed. Detail comparison the data of the granitoids of the Forsmark site in Sweden and the data of the granitoids of the Volyn megablock can be one of the next steps in researching the host rocks for the development of the RW disposal system in Ukraine.

  8. Use of petrophysical data for siting of deep geological repository of radioactive waste

    Directory of Open Access Journals (Sweden)

    Petrenko Liliana

    2017-01-01

    Full Text Available The paper is devoted to analyzing the petrophysical properties and petrographical characteristics of Volyn region with the view to choosing the least permeable and so the most suitable geological formation for the radioactive waste disposal. On a basis of the petrophysical estimations of the granitoids properties the argumentation of permeability has been developed for the petrotypes of Volyn region. Also method of classification of the petrotypes with their relative rate of suitability for radioactive waste disposal was developed. As a result of studying the perspectives were shown of the zhytomyr and korosten types of the granitoids as host rock for the radioactive waste disposal. According to the results of investigations performed by Swedish researchers a comparative analysis of rocks based on the age of formation, composition, structural features and some petrophysical properties of granitoids as host rocks for repository of radioactive waste was performed. Detail comparison the data of the granitoids of the Forsmark site in Sweden and the data of the granitoids of the Volyn megablock can be one of the next steps in researching the host rocks for the development of the RW disposal system in Ukraine.

  9. Feasibility studies for a radioactive waste repository in a deep clay formation

    International Nuclear Information System (INIS)

    Chapman, N.; Tassoni, E.

    1985-01-01

    This report assesses the feasibility of deep geological disposal of long-lived, heat-emitting radioactive wastes produced from the Italian nuclear power programme. Disposal is envisaged in argillaceous formations of medium plasticity at depths between 200 and 3000 metres. Thermal and geotechnical data, together with information on cost and feasibility of construction techniques are used to devise two conceptual designs (repository or deep borehole disposal) for a facility to contain all the high-level wastes arising from a 10 GWe power programme. Alternative designs and their merits are discussed and assessed. The two reference designs are used to construct a simple model of long-term performance and safety of the proposed disposal system. Recommendations are made for further work required to develop these concepts into an operational facility. It should be borne in mind that since no definite area or site has yet been identified for a disposal facility, all considerations are purely generic. Consequently data on rock properties and geological environment represent average values or best estimates for those likely to be encountered in the regions currently being considered as suitable for deep diposal purposes, and several broad assumptions have had to be made. However, the designs presented could be adapted without difficulty on a site-specific basis when the results of further research become available

  10. Safety- and performance indicators for a generic deep geological repository in clay

    International Nuclear Information System (INIS)

    Resele, G.; Niemeyer, M.; Wilhelm, St.; Heimer, St.; Mohlfeld, M.; Eilers, G.; Preuss, J.; Wollrath, J.

    2010-01-01

    Document available in extended abstract form only. As a first step of an impartial survey for an optimal site selection for a deep geological repository in Germany, potentially suitable regions shall be identified and localised according to their suitability. During the early phases of such a site selection procedure the information about the properties of the host rock and the geological situation at the potential sites is not very precise. As site investigation procedures are both expensive and time-consuming, it is essential to identify those properties of the geological barrier system that are most relevant for long-term safety. Furthermore, adequate indicators have to be chosen that allow a simple but efficient assessment of the suitability of the potential regions. Definition and application of 'exclusion criteria' based on single parameter values, e.g. the hydraulic conductivity of the host rock, is inadequate because the long-term safety depends on the interaction of many features and properties of the barrier system. In a research project, indicators have been developed which depend on the most relevant properties of the geological barriers and estimate the overall performance of a repository system. The application of these indicators on the barrier properties which have been found during the investigations of potential repository sites in clay located in Germany, Switzerland and France demonstrates how, for instance, an unfavourably high hydraulic permeability of the clay can be compensated by a large vertical extension of the clay layer and small hydraulic gradients. Other indicators evaluate the importance of hydraulic discontinuities and define the minimal requirements on technical barriers like seals and backfill of emplacement tunnels. When the information of the radionuclide inventory and the biosphere, especially the diluting aquifer is included, the indicators allow the estimation of the resulting dose which matches the result of a

  11. Development of emergency arrangements for the transport of radioactive waste to a deep repository

    International Nuclear Information System (INIS)

    Gray, I.L.S.; Hutchinson, D.L.; Burgess, M.H.; Higson, J.; Randall, M.A.

    1993-01-01

    This paper summarises the results of the studies and discussions which have led to the recommendation that Nirex should adopt NIREP as the Emergency Plan for the proposed transport arrangements of radioactive waste to the proposed UK deep repository for the disposal of low level and intermediate level waste. Although NIREP is currently specific to the road transport of radioactive materials, it is in the process of being extended to cover their transport by rail. An extended version of NIREP, covering both road and rail transport, could be operational by the end of 1992. NIREP is an established plan which meets all the current legal requirements and is flexible enough to accommodate any likely changes in legislation in the future. It is compatible with the Planning Basis and meets the requirements of the Emergency Plan Specification. The extended version of NIREP will be subject to an annual full-scale exercise and the Plan should be well-proven by the time that transport of waste packages to the repository commences. (J.P.N.)

  12. The potential significance of permafrost to the behaviour of a deep radioactive waste repository

    International Nuclear Information System (INIS)

    McEwen, T.; Marsily, G.de

    1991-02-01

    Permafrost is one of the scenarios that is being considered as part of the groundwater flow and transport modelling for the Project-90 assessment. It is included as one of the primary Features, Events and Processes (FEPs) which are being kept outside the Process System in the SKB/SKI scenario development project. There is a large amount of evidence that Sweden has suffered several cycles of permafrost development over the Quaternary, approximately the last 2My, and climatic predictions for the next hundred thousand years suggest that similar climatic cycling is likely to occur. The presence of permafrost could have important effects on the hydrogeological regime and could therefore be important in modifying the release and dispersion of radionuclides from a repository. The climatic conditions of permafrost would also influence radionuclide migration and accumulation in the biosphere and the associated radiation exposure of man. These biosphere aspects are not considered here but the implications for discharge into the biosphere are examined, including the abstraction of groundwater by man in permafrost regions. This report reviews the evidence relating to permafrost development and discusses the possible implications for the long-term safety of a deep repository. (78 refs.) (au)

  13. Guidelines for the operation and closure of deep geological repositories for the disposal of high level and alpha bearing wastes

    International Nuclear Information System (INIS)

    1991-10-01

    The operation and closure of a deep geological repository for the disposal of high level and alpha bearing wastes is a long term project involving many disciplines. This unique combination of nuclear operations in a deep underground location will require careful planning by the operating organization. The basic purpose of the operation stage of the deep repository is to ensure the safe disposal of the radioactive wastes. The purpose of the closure stage is to ensure that the wastes are safely isolated from the biosphere, and that the surface region can be returned to normal use. During these two stages of operation and closure, it is essential that both workers and the public are safely protected from radiation hazards, and that workers are protected from the hazards of working underground. For these periods of the repository, it is essential to carry out monitoring for purposes of radiological protection, and to continue testing and investigations to provide data for repository performance confirmation and for final safety assessment. Over the lengthy stages of operation and closure, there will be substantial feedback of experience and generation of site data. These will lead both to improved quality of operation and a better understanding of the site characteristics, thereby enhancing the confidence in the ability of the repository system to isolate the waste and protect future generations. 15 refs

  14. New developments in measurements technology relevant to the studies of deep geological repositories in bedded salt

    International Nuclear Information System (INIS)

    Mao, N.; Ramirez, A.L.

    1980-01-01

    This report presents new developments in measurement technology relevant to the studies of deep geological repositories for nuclear waste disposal during all phases of development, i.e., site selection, site characterization, construction, operation, and decommission. Emphasis has been placed on geophysics and geotechnics with special attention to those techniques applicable to bedded salt. The techniques are grouped into sections as follows: tectonic environment, state of stress, subsurface structures, fractures, stress changes, deformation, thermal properties, fluid transport properties, and other approaches. Several areas that merit further research and developments are identified. These areas are: in situ thermal measurement techniques, fracture detection and characterization, in situ stress measurements, and creep behavior. The available instrumentations should generally be improved to have better resolution and accuracy, enhanced instrument survivability, and reliability for extended time periods in a hostile environment

  15. Proposal for the classification of scenarios for deep geological repositories in probability classes

    International Nuclear Information System (INIS)

    Beuth, Thomas

    2013-03-01

    The provided report was elaborated in the framework of the project 3609R03210 ''Research and Development for Proof of the long-term Safety of Deep Geological Repositories''. It contains a proposal for a methodology that enables the assignment of developed scenarios in the frame of Safety Cases to defined probability classes. The assignment takes place indirectly through the categorization of the defining relevant factors (so-called FEP: Features, Events and Processes) of the respective scenarios also in probability classes. Therefore, decision trees and criteria were developed for the categorization of relevant factors in classes. Besides the description of the methodology another focal point of the work was the application of the method taking into account a defined scenario. By means of the scenario the different steps of the method and the decision criteria were documented, respectively. In addition, potential subjective influences along the path of decisions regarding the assignment of scenarios in probability classes were identified.

  16. Canada's deep geological repository for used nuclear fuel - the geoscientific site evaluation process

    Energy Technology Data Exchange (ETDEWEB)

    Belfadhel, M.B.; Blyth, A.; Desroches, A.; Hirschorn, S.; Mckelvie, J.; Sanchez-Rico Castejon, M.; Parmenter, A.; Urrutia-Bustos, A.; Vorauer, A., E-mail: mbenbelfadhel@nwmo.ca [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2014-07-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for the long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable crystalline or sedimentary rock formation. In May 2010, the NWMO initiated a nine-step site selection process to find an informed and willing community to host the project. This paper describes the approach, methods and criteria being used to assess the geoscientific suitability of communities currently involved in the site selection process. The social, cultural and economic aspects of the assessment are discussed in a companion paper. (author)

  17. Mechanisms and modelling of gas migration from deep radioactive waste repositories

    International Nuclear Information System (INIS)

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

    1992-06-01

    This report discusses the mechanisms by which gas is able to migrate through the far-field. The mechanisms available are diffusion or advection of gas dissolved in groundwater or free gas phase flow as either bubbles or a continuous stream of gas. Modelling approaches adopted to assess the migration are (a) simple use of Darcy's law with an effective permeability to gas, (b) the development of a model based on the representation of the far-field rock as a bundle of capillaries with a suitable distribution of radii, and (c) the use of a numerical model of two-phase flow in porous media. Finally, surveys have been carried out of published work on gas escape from underground storage caverns and of literature relating to gas movement from underground hydrocarbon accumulations to determine whether these may be potential sources of data or understanding of underground gas migration relevant to that from deep waste repositories. (author)

  18. New developments in measurements technology relevant to the studies of deep geological repositories in bedded salt

    Science.gov (United States)

    Mao, N. H.; Ramirez, A. L.

    1980-10-01

    Developments in measurement technology are presented which are relevant to the studies of deep geological repositories for nuclear waste disposal during all phases of development, i.e., site selection, site characterization, construction, operation, and decommission. Emphasis was placed on geophysics and geotechnics with special attention to those techniques applicable to bedded salt. The techniques are grouped into sections as follows: tectonic environment, state of stress, subsurface structures, fractures, stress changes, deformation, thermal properties, fluid transport properties, and other approaches. Several areas that merit further research and developments are identified. These areas are: in situ thermal measurement techniques, fracture detection and characterization, in situ stress measurements, and creep behavior. The available instrumentations should generally be improved to have better resolution and accuracy, enhanced instrument survivability, and reliability for extended time periods in a hostile environment.

  19. A method of identifying social structures in siting regions for deep geological repositories in Switzerland

    International Nuclear Information System (INIS)

    Brander, Simone

    2010-09-01

    Acceptance is a key element in the site selection process for deep geological repositories for high-level and low and intermediate-level radioactive waste in Switzerland. Participation requirements such as comprehensive negotiation issues and adequate resources have thus been defined by the Swiss Federal Office of Energy (SFOE). In 2008, on the basis of technical criteria Nagra (National Cooperative for the Disposal of Radioactive Waste) proposed several potential areas for deep geological repositories. The number of potential areas will be narrowed down within the next few years. All municipalities within the planning perimeter (the area in which surface facilities can be realised) are affected and form the siting region. In order to ensure that the local population have their say in the forthcoming discussions, regional participation bodies including all municipalities within a siting region are being set up by the SFOE. Regional participation ensures that local interests, needs and values are taken into account in the site selection process. Assembling the regional participation bodies is therefore of great importance. Before such bodies can be formed, however, the various interests, needs and values have to be identified, and special attention has to be paid to long-term interests of future generations, as well as to non-organised and under-represented interests. According to the concept of proportional representation, the interests, needs and values that are identified and weighted by the local population are to be represented in the regional participation procedure. The aim of this study is to share a method of mapping existing social structures in a defined geographical area. This involves a combination of an analysis of socio-economic statistical data and qualitative and quantitative social research methods

  20. Finite element code FENIA verification and application for 3D modelling of thermal state of radioactive waste deep geological repository

    Science.gov (United States)

    Butov, R. A.; Drobyshevsky, N. I.; Moiseenko, E. V.; Tokarev, U. N.

    2017-11-01

    The verification of the FENIA finite element code on some problems and an example of its application are presented in the paper. The code is being developing for 3D modelling of thermal, mechanical and hydrodynamical (THM) problems related to the functioning of deep geological repositories. Verification of the code for two analytical problems has been performed. The first one is point heat source with exponential heat decrease, the second one - linear heat source with similar behavior. Analytical solutions have been obtained by the authors. The problems have been chosen because they reflect the processes influencing the thermal state of deep geological repository of radioactive waste. Verification was performed for several meshes with different resolution. Good convergence between analytical and numerical solutions was achieved. The application of the FENIA code is illustrated by 3D modelling of thermal state of a prototypic deep geological repository of radioactive waste. The repository is designed for disposal of radioactive waste in a rock at depth of several hundred meters with no intention of later retrieval. Vitrified radioactive waste is placed in the containers, which are placed in vertical boreholes. The residual decay heat of radioactive waste leads to containers, engineered safety barriers and host rock heating. Maximum temperatures and corresponding times of their establishment have been determined.

  1. United States of America activities relative to the International Atomic Energy Agency (IAEA) initiative: Records management for deep geologic repositories

    Energy Technology Data Exchange (ETDEWEB)

    Warner, P.J.

    1997-03-01

    The International Atomic Energy Agency (IAEA) has conducted consultant and advisory meetings to prepare a Technical Document which is intended to provide guidance to all IAEA Member States (otherwise known as countries) that are currently planning, designing, constructing or operating a deep or near surface geological repository for the storage and protection of vitrified high-level radioactive waste, spent fuel waste and TRU-waste (transuranic). Eleven countries of the international community are presently in various stages of siting, designing, or constructing deep geologic repositories. Member States of the IAEA have determined that the principle safety of such completed and operation sites must not rely solely on long term institutional arrangements for the retention of information. It is believed that repository siting, design, operation and postoperation information should be gathered, managed and retained in a manner that will provide information to future societies over a very long period of time. The radionuclide life is 10,000 years thus the retention of information must outlive current societies, languages, and be continually migrated to new technology to assure retrieval. This presentation will provide an overview of the status of consideration and implementation of these issues within the United States efforts relative to deep geologic repository projects.

  2. United States of America activities relative to the International Atomic Energy Agency (IAEA) initiative: Records management for deep geologic repositories

    International Nuclear Information System (INIS)

    Warner, P.J.

    1997-01-01

    The International Atomic Energy Agency (IAEA) has conducted consultant and advisory meetings to prepare a Technical Document which is intended to provide guidance to all IAEA Member States (otherwise known as countries) that are currently planning, designing, constructing or operating a deep or near surface geological repository for the storage and protection of vitrified high-level radioactive waste, spent fuel waste and TRU-waste (transuranic). Eleven countries of the international community are presently in various stages of siting, designing, or constructing deep geologic repositories. Member States of the IAEA have determined that the principle safety of such completed and operation sites must not rely solely on long term institutional arrangements for the retention of information. It is believed that repository siting, design, operation and postoperation information should be gathered, managed and retained in a manner that will provide information to future societies over a very long period of time. The radionuclide life is 10,000 years thus the retention of information must outlive current societies, languages, and be continually migrated to new technology to assure retrieval. This presentation will provide an overview of the status of consideration and implementation of these issues within the United States efforts relative to deep geologic repository projects

  3. Diffusive Transport of Sulphide through an Engineering Barrier System in a Deep Geological Repository

    Science.gov (United States)

    Briggs, S. A.; Sleep, B. E.; McKelvie, J. R. M.; Krol, M.

    2015-12-01

    Bentonite is a naturally occurring clay-rich sediment containing montmorillonite, a smectitic clay mineral that has a high cation exchange capacity and swells upon contact with water. Owing to these characteristics, highly compacted bentonite (HCB) is an often included component of engineered barrier systems (EBS) designed to protect used fuel containers (UFCs) in deep geological repositories (DGR) for high-level nuclear waste. The low water activity and high swelling pressure of HCB suppresses microbial activity and the related production of sulphide that could cause microbiologically influenced corrosion (MIC) of UFCs The Canadian Nuclear Waste Management Organization (NWMO) has chosen a UFC that consists of an inner steel core and outer copper coating which is resistant to corrosion. However, under anaerobic conditions, MIC can still contribute to UFC corrosion if sulphides are present in the groundwater. Therefore the EBS consisting of bentonite blocks and pellets has been designed to impede the movement of sulphides to the UFC. In order to examine the effectiveness of the EBS, a 3D numerical model was developed capable of simulating the diffusive transport of sulphide within the NWMO EBS. The model was developed using COMSOL Multiphysics, a finite element software package and is parametric which allows the impact of different repository layouts to be assessed. The developed model was of the entire NWMO placement room, as well as, a stand-alone UFC and included conservative assumptions such as a fully saturated system and a constant concentration boundary condition. The results showed that the highest sulphide flux occurred at the semi-spherical end caps of the UFC. Further studies examined the effect of sulphide hotspots and fractures, representing possible EBS failure mechanisms. The model results highlight that even with conservative assumptions the chosen EBS will effectively protect the UFC from microbiologically influenced corrosion.

  4. Project SAFE. Microbial features, events and processes in the Swedish final repository for low-and intermediate-level radioactive waste

    International Nuclear Information System (INIS)

    Pedersen, Karsten

    2001-01-01

    The waste disposed of in the Swedish final repository for low and intermediate radioactive waste (SFR) typically contains large amounts of organic substances. This waste thus constitutes a possible source of energy and nutrients for microorganisms. Microbes can degrade the waste to degradation products, which to a varying degree may create problems if the process is significant. The environment for microbial life in the SFR is, however, unique since it cannot be compared to any environment to which microbes have adapted naturally over millions of years. Most similar to the SFR are waste dumps and landfills. In those, microbes degrade the waste and form degradation products. The experience from such 'analogues' and from research performed under repository-like conditions may provide useful clues about the microbial processes which may occur in the repository. Microbes have the ability to degrade bitumen, used to solidify some wastes, but this degradation is very slow under anaerobic conditions. Bitumen degradation will, therefore, not influence the safety of the SFR. However, some microbes can produce acids that could influence concrete stability, particularly in the presence of oxygen. The future SFR environment is anaerobic, which suggests that acid production is a very unlikely problem. Sulphate-reducing bacteria (SRB) have the ability to produce sulphide, which may act as a corrosive on metals. Under specific conditions, with the local groundwater flow close to a metal surface and with dissolved organic material from the repository, pitting corrosion of metal canisters is a potential threat. This process appears to require conditions fairly atypical of the SFR, however. Large groups of microorganisms can use hydrogen as a source of energy, thereby contributing to the decrease of this gas mainly formed from water during the anaerobic corrosion of metals. Cellulose is an excellent substrate for many microorganisms and it will be the dominating carbon and energy

  5. Project SAFE. Microbial features, events and processes in the Swedish final repository for low-and intermediate-level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Pedersen, Karsten [Goeteborg Univ. (Sweden)

    2001-01-01

    The waste disposed of in the Swedish final repository for low and intermediate radioactive waste (SFR) typically contains large amounts of organic substances. This waste thus constitutes a possible source of energy and nutrients for microorganisms. Microbes can degrade the waste to degradation products, which to a varying degree may create problems if the process is significant. The environment for microbial life in the SFR is, however, unique since it cannot be compared to any environment to which microbes have adapted naturally over millions of years. Most similar to the SFR are waste dumps and landfills. In those, microbes degrade the waste and form degradation products. The experience from such 'analogues' and from research performed under repository-like conditions may provide useful clues about the microbial processes which may occur in the repository. Microbes have the ability to degrade bitumen, used to solidify some wastes, but this degradation is very slow under anaerobic conditions. Bitumen degradation will, therefore, not influence the safety of the SFR. However, some microbes can produce acids that could influence concrete stability, particularly in the presence of oxygen. The future SFR environment is anaerobic, which suggests that acid production is a very unlikely problem. Sulphate-reducing bacteria (SRB) have the ability to produce sulphide, which may act as a corrosive on metals. Under specific conditions, with the local groundwater flow close to a metal surface and with dissolved organic material from the repository, pitting corrosion of metal canisters is a potential threat. This process appears to require conditions fairly atypical of the SFR, however. Large groups of microorganisms can use hydrogen as a source of energy, thereby contributing to the decrease of this gas mainly formed from water during the anaerobic corrosion of metals. Cellulose is an excellent substrate for many microorganisms and it will be the dominating carbon and

  6. New developments in measurement technology relevant to the studies of deep geological repositories in domed salt and basalt

    International Nuclear Information System (INIS)

    Ramirez, A.L.; Mao, N.H.

    1980-01-01

    This report briefly describes recent geophysical and geotechnical instrumentation developments relevant to the studies of deep geologic repositories. Special emphasis has been placed on techniques that appear to minimize measurement problems associated with repositories constructed in basalt or domed salt. Included in the listing are existing measurement capabilities and deficiencies that have been identified by a few authors and instrumentation workshops that have assessed the capabilities of existing instrumentation with respect to repository applications. These deficiencies have been compared with the reported advantages and limitations of the new developments described. Based on these comparisons, areas that merit further research and development have been identified. The report is based on a thorough literature review and on discussions with several instrumentation specialists involved in instrumentation development

  7. Waste package transfer, emplacement and retrievability in the French deep geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Roulet, Alain; Delort, Daniel; Herve, Jean Francois; Bosgiraud, Jean Michel; Guenin, Jean Jacques [Technical Department ANDRA (France)

    2009-06-15

    Safe, reliable and reversible handling of waste is a significant issue related to the design and safety assessment of deep geological repository in France. The first step taken was to study various waste handling solutions. ANDRA also decided to fabricate and demonstrate industrial scale handling equipment for HLW (since 2003) and for ILW-LL wastes (since 2008). We will review the main equipment developed for the transfer process in the repository, for both types of waste, and underline the benefits of developing industrial demonstrators within the framework of international cooperation agreements. Waste retrieval capability will be simultaneously examined. Two types of waste have to be handled underground in Andra's repository. The HLW disposal package for vitrified waste is a 2 ton carbon steel cylindrical canister with a diameter of 600 mm. The weight of ILW-LL concrete disposal packages range from a minimum of 6 tonnes to over 20 tonnes, and their volume from approximately 5 to 10 m3. The underground transfer to the disposal drift requires moving the disposal package within a shielded transfer cask placed on a trailer. Transfer cask design has evolved since 2005, due to optimisation studies and as a result of industrial feedback from SKB. For HLW handling equipment two design options have been studied. In the first solution (Andra's Dossier 2005), the waste package are emplaced, one at a time, in the disposal drift by a pushing robot. Successive steps in design and proto-typing have lead to improve the design of the equipment and to gain confidence. Recently a fully integrated process has been successfully demonstrated, at full scale, (in a 100 m long mock up drift) as part of the EC funded ESDRED Project. This demonstrator is now on display in Andra's Technology Centre at Saudron, near the Bure Underground Laboratory. The second disposal option which has been investigated is based on a concept of utilising an external apparatus to push a row of

  8. Methodology for the biosphere analysis in the evaluation of deep geological repositories for high radioactive waste

    International Nuclear Information System (INIS)

    Cancio, D.; Pinedo, P.; Aguero, A.; Simon, I.; Torres, C.; Robles, B.; Smith, G.M.; Little, R.; Watkings, B.; Brice, A.; Jaen, J.A.; Coronado, S.

    1997-01-01

    This report summarizes the work done and the achievements reached within the R and D Project that IMA/CIEMAT has had with ENRESA during 1993-1995. The overal R and D Project has a wide radiological protection context, but the work reported here relates only to the development of a Methodology for considering the Biosphere sub-system in the assessments of deep geological repositories for high radioactive wastes (HLW). The main areas concerned within the Methodology have to do with Biosphere structure and morphology in the long-term relevant to deep disposal of HLW: in the contexts of the assessment of these systems, and appropiate modelling of the behaviour of radionuclides released to the biosphere system and with the associated human exposure. This document first provides a review of the past and present international and national concerns about the biosphere modelling and its importance in relation to the definition of safety criteria. A joint ENRESA/ANDRA/IPSN/CIEMAT study about the definition and proactical descriptions of the biosphere systems under different climatic states is then summarized. The Methodology developed by IMA/CIEMAT is outlined with an illustration of the way it works. Different steps and procedures are included for a better proactical understanding of the software tools developed within the project to support the application of the Methologoy. This Methodology is widely based on an international working group on Reference Biospheres part national work for ENRESA has been supported under a collaborative agreement with QuantiSci Ltd. Specific software development have been carried out in collaboration with QuantiSci Ltd and with the Polytechnical University of Madrid. Most of the items included within the Methodology and moreover the Methodology as a whole, follows a continuos progressive development. It is increasinaly recognized that assessment capabilities, establisment of safety criteria and regulatory framework and the steps in a

  9. Regional and site geological frameworks : proposed Deep Geologic Repository, Bruce County, Ontario

    Energy Technology Data Exchange (ETDEWEB)

    Raven, K.; Sterling, S.; Gaines, S.; Wigston, A. [Intera Engineering Ltd., Ottawa, ON (Canada); Frizzell, R. [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2009-07-01

    The Nuclear Waste Management Organization is conducting geoscientific studies on behalf of Ontario Power Generation into the proposed development of a Deep Geologic Repository (DGR) for low and intermediate level radioactive waste (L and ILW) at the Bruce site, near Tiverton, Ontario. This paper presented a regional geological framework for the site that was based on a review of regional drilling; structural geology; paleozoic stratigraphy and sedimentology; a 3D geological framework model; a DGR geological site characterization model; bedrock stratigraphy and marker beds; natural fracture frequency data; and formation predictability. The studies have shown that the depth, thickness, orientation and rock quality of the 34 rock formations, members or units that comprise the 840 m thick Paleozoic bedrock sequence at the Bruce site are very uniform and predictable over distances of several kilometres. The proposed DGR will be constructed as an engineered facility comprising a series of underground emplacement rooms at a depth of 680 metres below ground within argillaceous limestones. The geoscientific studies are meant to provide a basis for the development of descriptive geological, hydrogeological and geomechanical models of the DGR site that will facilitate environmental and safety assessments. 11 refs., 3 tabs., 9 figs.

  10. Environmental assessment for OPG's deep geologic repository for low and intermediate level waste

    International Nuclear Information System (INIS)

    Barker, D.; Rawlings, M.; Beal, A.

    2011-01-01

    The environmental assessment process for the Deep Geologic Repository (DGR) Project was initiated very early in the planning stages. Feasibility studies were initiated in 2003, after Ontario Power Generation (OPG) and the Municipality of Kincardine signed a Memorandum of Understanding agreeing to assess options for long-term management of low and intermediate level waste (L and ILW) options at the Bruce nuclear site. The location of the DGR, in the Municipality of Kincardine, is based on a willing and informed host community. The preferred approach, the DGR at the Bruce nuclear site, was advanced based on results of feasibility studies which looked at a number of options for long-term management of L&ILW and support from the local community and their elected representatives. The federal environmental assessment of the project was initiated following the signing of a Host Community Agreement and completion of a telephone poll, the results of which indicated that the majority of Municipality of Kincardine residents support the project. The environmental assessment began in 2006 as a comprehensive study and was ultimately referred to a joint review panel process in 2009. The environmental assessment considers the potential near-term effects of the construction and operations of the proposed project. Because of the nature of the project, the assessment of effects also considers long-term effects extending out to the million year time-frame, including effects of climate change, glaciations and seismic activity. (author)

  11. The study of fracture mineralization and relationship with high level radioactive waste of deep geological repository

    International Nuclear Information System (INIS)

    Reyes, Cristina N.

    2003-01-01

    Extensive investigations of the Ordovician, Dinantian and Permo-Triassic rocks of the Sellafield area of northwest England were undertaken by United Kingdom Nirex Ltd. as a possible national site for geological disposal of intermediate and low-level radioactive waste. Very detailed studies of fracture mineralisation at Sellafield were thus put in hand by Nirex Ltd. and the results summarised by the British Geological Survey. Deep (up to 2 km) boreholes were put down with excellent core recovery. It is generally agreed that the most significant pathway for the escape of all but a very few radionuclides is by solution in and advection of groundwater. In this context, rock fracture systems are particularly important because they offer a potentially rapid pathway to the surface and the biosphere. One striking aspect of this work is that the fracture mineralisation seemingly records major and rapid fluctuations in redox conditions -sometimes during apparently continuous precipitation of cements (ferroan and non-ferroan calcites, dolomite). Carbonate cements record variations in Fe 2+ availability. Fe(III) precipitates also as oxide (hematite) and Fe(II) as sulphide (pyrite). This study focuses on these elements and valence states and also on Mn; another element susceptible to redox controls but known to respond differently from Fe. Shallow sub-surface stores or repositories would be more likely to have oxidising or fluctuating redox conditions. The mineralisation sequences documented at Sellafield are potentially promising in this context. Ferroan carbonate cements are sensitive indicators of later movement of oxidising ground waters. (author)

  12. Canada's deep geological repository for used nuclear fuel - update on the site evaluation process and interweaving of aboriginal traditional knowledge

    International Nuclear Information System (INIS)

    Watts, B.; Belfadhel, M.B.; Facella, J.

    2015-01-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for the long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository (DGR) in a suitable crystalline or sedimentary rock formation. In May 2010, the NWMO initiated a nine-step site selection process to seek an informed and willing community to host Canada's deep geological repository. As of April 2015, twenty-two communities expressed interest in learning more about the project. This paper provides an update on the site evaluation process and describes the approach, methods and criteria used in the assessments, focusing on geological and community well-being studies. Engagement and field activities to interweave Aboriginal Traditional Knowledge with western science are also discussed. (author)

  13. Architecture Design Issues of a Reversible Deep Geological Repository for HL and IL/LL Waste

    Energy Technology Data Exchange (ETDEWEB)

    Bauer, C.; Londe, L.; Poisson, J.B. [Andra (France)

    2009-06-15

    In accordance with the Planning Act of 28 June 2006, the French National Radioactive Waste Management Agency (Agence nationale pour la gestion des dechets radioactifs - ANDRA) is currently investigating the possibility of disposing of high-level (HL) and intermediate-level long-lived (IL/LL) radioactive waste in a deep geological formation. The waste inventory intended for geological disposal is significant and represents approximately 80,000 m{sup 3} of primary waste. The required drifts and cells for such disposal are developing in a long and complex network, with plans calling for a total of about 300 km of drifts to be opened over the next century. This paper describes various issues relating to the architecture design and the way they are integrated. Long-term safety is at the basis of the major principles not only for dividing the different waste categories into separate disposal areas, but also for identifying the relevant constraints involving the topology of the network (fragmentation of disposal areas into modules, dead-end architecture) and the orientation of certain structures. In the case of exothermal waste, since the control over the phenomenological evolution also leads to selecting a thermal criterion in the geological layer in contact with the waste, there is an impact on the density of the repository and, consequently, on its architecture. Operational security and safety issues are reflected in ventilation needs and in personnel-evacuation requirements in case of fire, both of which require additional intersections and drifts. The section of drifts is also conditioned often by those security aspects. Nuclear zoning may also induce requirements for special structures having a potential impact on the architecture. Operation, taken into its broader sense encompassing construction and nuclear activities, imposes its own share of constraints quite independently from any security or safety considerations. Impacted areas include structure slopes, the

  14. Deep repository for long-lived low- and intermediate-level waste in Sweden (SFL 3-5): An international peer review of SKB 's preliminary safety assessment

    International Nuclear Information System (INIS)

    Chapman, N.; Apted, M.; Glasser, F.; Voss, C.

    2000-10-01

    The SKB safety assessment of the SFL 3-5 repository (the planned deep repository for long-lived low- and intermediate level waste) can be read in two contexts: as a preliminary evaluation of the performance and design options for a repository that will not be required for perhaps forty years; or as an evaluation of a repository that might need to be sited together with the SFL 2 spent fuel repository, and whose nature and performance might thus need to be understood to a level that can be used to make wider programmatic decisions during the next five years. These two 'assessment contexts' are quite different, and an overarching issue is the fact that it was not clear to the review team which view to take. Apparently, SKB would tend towards the first context. However, it is not at all apparent to the reviewers why the second context should not be the predominant driver in the near future. The review team notes that the SFL 3-5 repository, as modelled by SKB, gives rise to potentially perceptible radionuclide releases to the environment on a timescale of hundreds of years after closure. This is in contrast to the SR 97 assessment for the SFL 2 spent fuel repository, which base scenario predicts no releases over a million year timescale. It is clear that according to SKB's SR97 and SFL3-5 analyses, for co-located facilities, it is this repository that has the potential for real radiological impacts in the immediate future. An initial recommendation from the review, is that SKB and the regulatory authorities consider which context is appropriate to the current status of the Swedish programme. This is important, because an overall impression of the reviewers is that the analysis would not be 'fit for purpose' if it were needed to assist with decision-making by SKB or the regulatory agencies. There are too many unanswered questions, and the overall impression of the safety concept is one of some fragility. Because there is no real design basis presented, no thorough

  15. Backfilling and closure of the deep repository. Assessment of backfill concepts

    International Nuclear Information System (INIS)

    Gunnarsson, David; Boergesson, Lennart; Keto, Paula; Tolppanen, Pasi; Hansen, Johanna

    2004-06-01

    This report presents the results from work made in Phase 1 of the joint SKB-Posiva project 'Backfilling and Closure of the Deep Repository' aiming at selecting and developing materials and techniques for backfilling and closure of a KBS-3 type repository for spent nuclear fuel. The aim of phase 1, performed as a desk study, was to describe the potential of the suggested backfill concepts in terms of meeting SKB and Posiva requirements, select the most promising ones for further investigation, and to describe methods that can be used for determining the performance of the concepts. The backfilling concepts described in this report differ from each other with respect to backfill materials and installation techniques. The concepts studied are the following: Concept A: Compaction of a mixture of bentonite and crushed rock in the tunnel. Concept B: Compaction of natural clay with swelling ability in the tunnel. Concept C: Compaction of non-swelling soil type in the tunnel combined with application of pre-compacted bentonite blocks at the roof. Concept D: Placement of pre-compacted blocks; a number of materials are considered. Concept E: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The bentonite sections are installed regularly above every disposal hole. Concept F: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The distance between the bentonite sections is adapted to the local geology and hydrology.The assessment of the concepts is based on performance requirements set for the backfill in the deposition tunnels for providing a stable and safe environment for the bentonite buffer and canister for the repository service time. In order to do this, the backfill should follow certain guidelines, 'design criteria' concerning compressibility, hydraulic conductivity, swelling ability, long-term stability, effects on the barriers and

  16. Backfilling and closure of the deep repository. Assessment of backfill concepts

    Energy Technology Data Exchange (ETDEWEB)

    Gunnarsson, David; Boergesson, Lennart [Clay Technology AB, Lund (Sweden); Keto, Paula [Saanio Riekkola Oy (Finland); Tolppanen, Pasi [Jaakko Poeyry Infra (Finland); Hansen, Johanna [Posiva Oy, Helsinki (Finland)

    2004-06-01

    This report presents the results from work made in Phase 1 of the joint SKB-Posiva project 'Backfilling and Closure of the Deep Repository' aiming at selecting and developing materials and techniques for backfilling and closure of a KBS-3 type repository for spent nuclear fuel. The aim of phase 1, performed as a desk study, was to describe the potential of the suggested backfill concepts in terms of meeting SKB and Posiva requirements, select the most promising ones for further investigation, and to describe methods that can be used for determining the performance of the concepts. The backfilling concepts described in this report differ from each other with respect to backfill materials and installation techniques. The concepts studied are the following: Concept A: Compaction of a mixture of bentonite and crushed rock in the tunnel. Concept B: Compaction of natural clay with swelling ability in the tunnel. Concept C: Compaction of non-swelling soil type in the tunnel combined with application of pre-compacted bentonite blocks at the roof. Concept D: Placement of pre-compacted blocks; a number of materials are considered. Concept E: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The bentonite sections are installed regularly above every disposal hole. Concept F: Combination of sections consisting of a) crushed rock compacted in the tunnel and b) pre-compacted bentonite blocks. The distance between the bentonite sections is adapted to the local geology and hydrology.The assessment of the concepts is based on performance requirements set for the backfill in the deposition tunnels for providing a stable and safe environment for the bentonite buffer and canister for the repository service time. In order to do this, the backfill should follow certain guidelines, 'design criteria' concerning compressibility, hydraulic conductivity, swelling ability, long-term stability, effects on

  17. Evaluation of SKB's report 'Deep repository for spent nuclear fuel: SR 97 - Post-closure safety', Focusing on the assessment of transport processes in the geosphere

    International Nuclear Information System (INIS)

    Woerman, A.; Shulan Xu

    2000-01-01

    This report describes a critical review of the safety assessment performed on the final repository for nuclear waste in Sweden that is proposed by SKB in 'Deep Repository for Spent Nuclear Fuel: SR 97 - Post-closure Safety'. The review was requested by the Swedish Nuclear Power Inspectorate (SKI). The waste repository consists of several barriers that work together with the purpose of delaying radionuclide migration and reducing the activity that eventually affects the biosphere. A main criticism is the lack of a formal risk analysis and uncertainties in several analyses that make it difficult to comprehend the overall risk of the repository. A formal risk analysis should comprise a probabilistic treatment of all components included in the system. This is not the case in the SKB's report since the probabilistic analyses are limited only to certain aspects. The use of conservative model parameters are not a substitute for risk analysis nor can they compensate for possible model biases. Bias can be expected in most of the existing models of radionuclide migration in fractured bedrock. SKB should present a clear comparison on the importance of the different barrier components (uranium-dioxide matrix, copper canister, buffer and bedrock) on the retardation of radionuclides. It is unclear as to what extent the capacity of the bedrock to retain migrating radionuclides is critical to the capacity of the repository. A large part of the SR 97 report is focused on retardation processes in bedrock and a reader can interpret this as the technical weight given on retardation in the bedrock. However, with the present state of knowledge, it is our opinion that we cannot with an acceptable degree of accuracy predict the radionuclide transport in bedrock or quantify risk levels associated with radioactivity in the biosphere. There are large uncertainties concerning the way by which sorption processes should be formulated and the impact of colloids on the transport that can be

  18. The Swedish radiological environmental protection regulations applied in a review of a license application for a geological repository for spent nuclear fuel.

    Science.gov (United States)

    Andersson, Pål; Stark, Karolina; Xu, Shulan; Nordén, Maria; Dverstorp, Björn

    2017-11-01

    For the first time, a system for specific consideration of radiological environmental protection has been applied in a major license application in Sweden. In 2011 the Swedish Nuclear Fuel & Waste Management Co. (SKB) submitted a license application for construction of a geological repository for spent nuclear fuel at the Forsmark site. The license application is supported by a post-closure safety assessment, which in accordance with regulatory requirements includes an assessment of environmental consequences. SKB's environmental risk assessment uses the freely available ERICA Tool. Environmental media activity concentrations needed as input to the tool are calculated by means of complex biosphere modelling based on site-specific information gathered from site investigations, as well as from supporting modelling studies and projections of future biosphere conditions in response to climate change and land rise due to glacial rebound. SKB's application is currently being reviewed by the Swedish Radiation Safety Authority (SSM). In addition to a traditional document review with an aim to determine whether SKB's models are relevant, correctly implemented and adequately parametrized, SSM has performed independent modelling in order to gain confidence in the robustness of SKB's assessment. Thus, SSM has used alternative stylized reference biosphere models to calculate environmental activity concentrations for use in subsequent exposure calculations. Secondly, an alternative dose model (RESRAD-BIOTA) is used to calculate doses to biota that are compared with SKB's calculations with the ERICA tool. SSM's experience from this review is that existing tools for environmental dose assessment are possible to use in order to show compliance with Swedish legislation. However, care is needed when site representative species are assessed with the aim to contrast them to generic reference organism. The alternative modelling of environmental concentrations resulted in much lower

  19. Anaerobic corrosion of carbon steel under unsaturated conditions in a nuclear waste deep geological repository

    International Nuclear Information System (INIS)

    Kwong, G.; Wang, St.; Newman, R.C.

    2009-01-01

    Full text of publication follows: Anaerobic corrosion behaviour of carbon steel in humid conditions, but not submerged in aqueous solution, was studied based on hydrogen generation. Initial tests monitored the hydrogen evolution from carbon steel in a high humidity environment (≥ 75% RH) at near-ambient temperature (30 C) using a high sensitivity pressure gauge system (sensitivity of 0.01 μm.a -1 ). The presence of hydrogen in test runs that showed no, or minimal, pressure increase was confirmed by a solid-state potentiometric hydrogen sensor which has the capability of detecting hydrogen partial pressure as low as 10 -6 bar or a corrosion rate of 1.5 * 10 -4 μm.a -1 . Preliminary results indicate that a corrosion rate as high as 0.2 μm.a -1 can be sustained for steel coated with salt at 100% RH. Higher corrosion rates (as high as 0.8 μm.a -1 ) were obtained in less humid environment (71% RH). Without a salt deposit, pickled steel in humid environment (as high as 100% RH) also showed detectable corrosion for a period up to 800 hours, during which 0.8 kPa of hydrogen was accumulated prior to the apparent arrest of corrosion, representing a metal loss of 3 nm. Corrosion scales are also identified with x-ray photoelectron spectroscopy (XPS) as well as by mass change monitoring using a quartz crystal microbalance. Corrosion mechanisms and prediction for longer-term exposure will be discussed. Results will be useful in predicting long-term carbon steel corrosion behaviour and improving the current knowledge of hydrogen gas evolution in a deep geological repository for nuclear waste. (authors)

  20. Impact of cementitious materials decalcification on transfer properties: application to radioactive waste deep repository

    International Nuclear Information System (INIS)

    Perlot, C.

    2005-09-01

    Cementitious materials have been selected to compose the engineering barrier system (EBS) of the French radioactive waste deep repository, because of concrete physico-chemical properties: the hydrates of the cementitious matrix and the pH of the pore solution contribute to radionuclides retention; furthermore the compactness of these materials limits elements transport. The confinement capacity of the system has to be assessed while a period at least equivalent to waste activity (up to 100.000 years). His durability was sustained by the evolution of transfer properties in accordance with cementitious materials decalcification, alteration that expresses structure long-term behavior. Then, two degradation modes were carried out, taking into account the different physical and chemical solicitations imposed by the host formation. The first mode, a static one, was an accelerated decalcification test using nitrate ammonium solution. It replicates the EBS alteration dues to underground water. Degradation kinetic was estimated by the amount of calcium leached and the measurement of the calcium hydroxide dissolution front. To evaluate the decalcification impact, samples were characterized before and after degradation in term of microstructure (porosity, pores size distribution) and of transfer properties (diffusivity, gas and water permeability). The influence of cement nature (ordinary Portland cement, blended cement) and aggregates type (lime or siliceous) was observed: experiments were repeated on different mortars mixes. On this occasion, an essential reflection on this test metrology was led. The second mode, a dynamical degradation, was performed with an environmental permeameter. It recreates the EBS solicitations ensured during the re-saturation period, distinguished by the hydraulic pressure imposed by the geologic layer and the waste exothermicity. This apparatus, based on triaxial cell functioning, allows applying on samples pressure drop between 2 and 10 MPa and

  1. 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.)

  2. A Nuclide Release Model for a Deep Well Scenario near a Repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Jung, Jong Tae; Choi, Jong Won

    2010-01-01

    Recently several template programs ready for the safety assessment of a high-level radioactive waste repository (HLW) and a low- and intermediate level radioactive waste repository (LILW) systems, that are conceptually modeled, have been developed by utilizing GoldSim and AMBER at KAERI. During the last few years, such template programs have been utilized for the evaluation of nuclide transports in the nearand far-field of a repository as well as transport through the biosphere under various normal and disruptive release scenarios with assumed data. The GoldSim program, another template program by which influence due to a well located very near to the repository has been modeled and evaluated for an assumed case in order to simulate the worst exposure scenario. This seems very useful to evaluate an accidental event a long time after closure of the repository has been developed and illustrated

  3. Development of an Integrated Natural Barrier Database System for Site Evaluation of a Deep Geologic Repository in Korea - 13527

    International Nuclear Information System (INIS)

    Jung, Haeryong; Lee, Eunyong; Jeong, YiYeong; Lee, Jeong-Hwan

    2013-01-01

    Korea Radioactive-waste Management Corporation (KRMC) established in 2009 has started a new project to collect information on long-term stability of deep geological environments on the Korean Peninsula. The information has been built up in the integrated natural barrier database system available on web (www.deepgeodisposal.kr). The database system also includes socially and economically important information, such as land use, mining area, natural conservation area, population density, and industrial complex, because some of this information is used as exclusionary criteria during the site selection process for a deep geological repository for safe and secure containment and isolation of spent nuclear fuel and other long-lived radioactive waste in Korea. Although the official site selection process has not been started yet in Korea, current integrated natural barrier database system and socio-economic database is believed that the database system will be effectively utilized to narrow down the number of sites where future investigation is most promising in the site selection process for a deep geological repository and to enhance public acceptance by providing readily-available relevant scientific information on deep geological environments in Korea. (authors)

  4. First Workshop on Design and Construction of Deep Repositories - Theme: Excavation through water-conducting major fracture zones

    International Nuclear Information System (INIS)

    Baeckblom, G.; Svemar, C.

    1994-01-01

    Final disposal of high-level nuclear waste has not yet been carried out in any country today. The concepts under development are all based on geological repositories, i.e., disposal at a sufficient depth below the surface to provide stable mechanical, hydrological and chemical conditions during the period the waste needs to be isolated from man. In the cases where crystalline bedrock is considered the proposed repository depths vary between 300-1000 m. The construction, operation and sealing of a deep geological repository must meet various criteria that in many respects are more detailed and more demanding than usual in underground construction projects today. The work shall be done so that occupational safety is ensured. The work also shall conform to whatever restrictions are necessary for ensuring pre-closure operational safety and post-closure long-term safety. March 1993 SKB arranged a two-day international workshop to discuss design and construction of repositories. Close to 40 participants from eight countries shared experiences regarding passage of major water-conducting fracture zones and other matters. This report summarizes the contributions to the workshop

  5. Addressing issues raised by stakeholders in the development of a deep geological repository in the Czech Republic

    International Nuclear Information System (INIS)

    Sumberova, Vera

    2004-01-01

    The mission of the Radioactive Waste Repository Authority (RAWRA) is to ensure the safe disposal of all existing and future radioactive waste. In order to fulfil this task RAWRA, in addition to the operation of radioactive waste repositories in the Czech Republic, coordinates all those activities relating to the construction of a deep geological repository. This long-term goal implies first creating and then building upon the public's confidence in the decision making process and the project as a whole as well as in RAWRA as a competent and efficient implementer since clearly public acceptance is an essential condition for a successful final outcome. Since its establishment in 1997 RAWRA has been looking for ways in which to inform the public about its activities and how to involve the various stakeholders in the development process. The communication tools employed to achieve this goal have, to date, depended on the specific stage of the process but RAWRA has aimed at a continuous improvement in its activities; consequently a large number of changes have been made to RAWRA's policy and approach in recent years. This paper, which aims to describe RAWRA's dialogue with stakeholders (mainly local communities), provides examples of the way in which issues raised by stakeholders concerning a repository are reflected in RAWRA's approach. (author)

  6. Redox processes in the safety case of deep geological repositories of radioactive wastes. Contribution of the European RECOSY Collaborative Project

    International Nuclear Information System (INIS)

    Duro, L.; Bruno, J.; Grivé, M.; Montoya, V.; Kienzler, B.; Altmaier, M.; Buckau, G.

    2014-01-01

    Highlights: • The RECOSY project produced results relevant for the Safety Case of nuclear disposal. • We classify the safety related features where RECOSY has contributed. • Redox processes effect the retention of radionuclides in all repository subsystems. - Abstract: Redox processes influence key geochemical characteristics controlling radionuclide behaviour in the near and far field of a nuclear waste repository. A sound understanding of redox related processes is therefore of high importance for developing a Safety Case, the collection of scientific, technical, administrative and managerial arguments and evidence in support of the safety of a disposal facility. This manuscript presents the contribution of the specific research on redox processes achieved within the EURATOM Collaborative Project RECOSY (REdox phenomena COntrolling SYstems) to the Safety Case of nuclear waste disposal facilities. Main objectives of RECOSY were related to the improved understanding of redox phenomena controlling the long-term release or retention of radionuclides in nuclear waste disposal and providing tools to apply the results to Performance Assessment and the Safety Case. The research developed during the project covered aspects of the near-field and the far-field aspects of the repository, including studies relevant for the rock formations considered in Europe as suitable for hosting an underground repository for radioactive wastes. It is the intention of this paper to highlight in which way the results obtained from RECOSY can feed the scientific process understanding needed for the stepwise development of the Safety Case associated with deep geological disposal of radioactive wastes

  7. 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.

  8. 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

  9. Microcrack growing and long-term mechanical stability in a HLW deep-borehole repository in granite

    International Nuclear Information System (INIS)

    Biurrun, E.; Hahne, K.

    1989-01-01

    The long-term host rock integrity assessment of a deep borehole emplacement for HLW in granite has been addressed with a detailed new constitutive model considering temperature and pressure effects on microscale phenomena (as microcracking) under repository conditions. The results of these finite element calculations have been compared with results obtained using conventional, state-of-the-art constitutive modelling. While the results of conventional modelling did suggest the existence of an important safety margin before failure, the improved calculations with the new model predict a thin but very long region of degradated host rock along the waste canister column. The results obtained up to now may well be considered as safety relevant, because they suggest that the actual long-term granite strength lies well below the conventionally determined failure limits, thus challenging the barrier properties of this host rock if the actual strength is not properly considered in the repository design

  10. Decommissioning of surface facilities associated with repositories for the deep geological disposal of high-level nuclear wastes

    International Nuclear Information System (INIS)

    Heckman, R.A.

    1978-11-01

    A methodology is presented in this paper to evaluate the decommissioning of the surface facilities associated with repositories for the deep geological disposal of high-level nuclear wastes. A cost/risk index (figure of merit), expressed as $/manrem, is proposed as an evaluation criteria. On the basis of this cost/risk index, we gain insight into the advisability of adapting certain decontamination design options into the original facility. Three modes are considered: protective storage, entombment, and dismantlement. Cost estimates are made for the direct labor involved in each of the alternative modes for a baseline design case. Similarly, occupational radiation exposures are estimated, with a larger degree of uncertainty, for each of the modes. Combination of these estimates produces the cost/risk index. To illustrate the methodology, an example using a preliminary baseline repository design is discussed

  11. Source-book of International Activities Related to the Development of Safety Cases for Deep Geological Repositories

    International Nuclear Information System (INIS)

    2017-01-01

    All national radioactive waste management authorities recognise today that a robust safety case is essential in developing disposal facilities for radioactive waste. To improve the robustness of the safety case for the development of a deep geological repository, a wide variety of activities have been carried out by national programs and international organisations over the past years. The Nuclear Energy Agency, since first introducing the modern concept of the 'safety case', has continued to monitor major developments in safety case activities at the international level. This Source-book summarises the activities being undertaken by the Nuclear Energy Agency, the European Commission and the International Atomic Energy Agency concerning the safety case for the operational and post-closure phases of geological repositories for radioactive waste that ranges from low-level to high-level waste and for spent fuel. In doing so, it highlights important differences in focus among the three organisations

  12. Plugs for deposition tunnels in a deep geologic repository in granitic rock. Concepts and experience

    International Nuclear Information System (INIS)

    Dixon, D. A.; Boergesson, L.; Gunnarsson, D.; Hansen, J.

    2009-11-01

    Regardless of the emplacement geometry selected in a geological repository for spent nuclear fuel, there will be a requirement for the access tunnels to remain open while repository operations are ongoing. The period of repository operation will stretch for many years (decades to more than a century depending on disposal concept and number of canisters to be installed). Requirements for extended monitoring of the repository before final closure may further extend the period over which the tunnels must remain open. The intersection of the emplacement rooms/drifts and the access tunnels needs to be physically closed in order to ensure that the canisters remain undisturbed and that no undesirable hydraulic conditions are allowed to develop within the backfilled volume. As a result of these requirements, generic guidelines and design concepts have been developed for 'Plugs' that are intended to provide mechanical restraint, physical security and hydraulic control functions over the short-term (repository operational and pre-closure monitoring periods). This report focuses on the role and requirements of plugs to be installed at emplacement room/ tunnel/drift entrances or in other locations within the repository that may require installation of temporary mechanical or hydraulic control structures. These plugs are not necessarily a permanent feature of the repository and may, if required, be removed for later installation of a permanent seal. Room/Drift plugs are also by their defined function, physically accessible during repository operation so their performance can be monitored and remedial actions taken if necessary (e.g. increased seepage past the plug). A considerable number of sealing demonstrations have been undertaken at several research laboratories that are focussed on development of technologies and materials for use in isolation of spent nuclear fuel and these are briefly reviewed in this report. Additionally, technologies developed for non

  13. Plugs for deposition tunnels in a deep geologic repository in granitic rock. Concepts and experience

    Energy Technology Data Exchange (ETDEWEB)

    Dixon, D.A. (AECL, Chalk River (Canada)); Boergesson, L. (Clay Technology, Lund (Sweden)); Gunnarsson, D. (Swedish Nuclear Fuel and Waste Management Co, Stockholm (Sweden)); Hansen, J. (Posiva Oy, Eurajoki (Finland))

    2009-11-15

    Regardless of the emplacement geometry selected in a geological repository for spent nuclear fuel, there will be a requirement for the access tunnels to remain open while repository operations are ongoing. The period of repository operation will stretch for many years (decades to more than a century depending on disposal concept and number of canisters to be installed). Requirements for extended monitoring of the repository before final closure may further extend the period over which the tunnels must remain open. The intersection of the emplacement rooms/drifts and the access tunnels needs to be physically closed in order to ensure that the canisters remain undisturbed and that no undesirable hydraulic conditions are allowed to develop within the backfilled volume. As a result of these requirements, generic guidelines and design concepts have been developed for 'Plugs' that are intended to provide mechanical restraint, physical security and hydraulic control functions over the short-term (repository operational and pre-closure monitoring periods). This report focuses on the role and requirements of plugs to be installed at emplacement room/ tunnel/drift entrances or in other locations within the repository that may require installation of temporary mechanical or hydraulic control structures. These plugs are not necessarily a permanent feature of the repository and may, if required, be removed for later installation of a permanent seal. Room/Drift plugs are also by their defined function, physically accessible during repository operation so their performance can be monitored and remedial actions taken if necessary (e.g. increased seepage past the plug). A considerable number of sealing demonstrations have been undertaken at several research laboratories that are focussed on development of technologies and materials for use in isolation of spent nuclear fuel and these are briefly reviewed in this report. Additionally, technologies developed for non

  14. 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

  15. Ontario Power Generation's proposed L and ILW deep geologic repository: geo-scientific assessment

    International Nuclear Information System (INIS)

    Jensen, Mark; Raven, Ken; Leech, Robert

    2012-01-01

    Document available in extended abstract form only. The Nuclear Waste Management Organization (NWMO) on behalf of Ontario Power Generation (OPG) has conducted multi-disciplinary geo-scientific studies at the Bruce nuclear site to confirm the suitability of the site to host a proposed Deep Geologic Repository (DGR) for the long-term management of Low and Intermediate Level Radioactive Waste (L and ILW) from OPG owned or operated nuclear generating facilities. An Environmental Assessment for the proposed DGR is currently underway in accordance with the Canadian Environmental Assessment Act. Bruce nuclear site, situated 225 km northwest of Toronto on the eastern shore of Lake Huron, is underlain by an 850 m thick sedimentary sequence of Cambrian to Devonian age near-horizontally layered, weakly deformed shales, carbonates and evaporites of the Michigan Basin. Within this sedimentary pile, the proposed DGR would be excavated within the low permeability argillaceous limestone of the Cobourg Formation at a depth of 680 m, which is overlain by 200 m of Upper Ordovician shale formations (Figure 1). A key aspect of the DGR Safety Case is the predictable nature and long-term stability and integrity of the sedimentary sequence to contain and isolate L and ILW at time frames on the order of 1 Ma. Early in the project, geo-scientific studies that considered regional and site-specific public domain data sets indicated favourable geologic conditions for implementation of the DGR concept (Golder, 2003; Mazurek, 2004). Geo-scientific studies for the DGR were initiated in 2006 following decision by the Municipality of Kincardine to support the DGR concept. Geo-scientific activities were divided into two key areas; i) Site-specific geo-scientific studies of the Bruce nuclear site (i.e., Descriptive Geosphere Site Model); and ii) a Geo-synthesis to convey an understanding of past, present and future evolution of Geosphere enclosing the DGR relevant to communicating notions of

  16. Deep geological repositories. Safe operation and long-term safety in the prism of reversibility

    Energy Technology Data Exchange (ETDEWEB)

    Espivent, Camille; Tichauer, Michael [IRSN, Fontenay-aux-Roses (France)

    2015-07-01

    A deep geological repository is the reference solution enshrined in the French law for the long-term management of high-level radioactive waste. The current project is led by Andra, the French radioactive waste management organization. As a technical support organization, IRSN's mission is, on the basis of the safety case produced by Andra, to assess the safety of such a facility at its various stages of development, that is to say the design, construction, operation and post-closure phases of the facility. Such a facility will have to meet specific requirements, within different time frames as stated above. One of the requirements is ''reversibility'': in fact, French law poses that the geological disposal will have to be ''reversible'' for a certain time, yet not fully defined. Reversibility is nevertheless believed encompassing both the decision making process related to the waste emplacement process during operational phase and the ability to retrieve waste, should such a decision be made. Thus, underground structures have to be designed and operated to allow both waste emplacement and removal. Moreover, future decision making about the disposal process will have to rely on a sound technical basis. This implies a data collection scheme and a monitoring program of the facility to check if the disposal process is bound by limits, controls and conditions compatible with (i) a safe operation of the facility and (ii) the state of the facility that the operator wants to achieve at the time of its closure, so that long-term safety is guaranteed. Therefore, technical criteria and key parameters have to be selected and monitored during construction and operation, that is to say for decades. Then, reversibility have to make room for corrective actions, including the retrieval of waste, if something goes wrong and especially if the facility is not seen as safe anymore, especially in the perspective of long-term safety. To

  17. Deep geological repositories. Safe operation and long-term safety in the prism of reversibility

    International Nuclear Information System (INIS)

    Espivent, Camille; Tichauer, Michael

    2015-01-01

    A deep geological repository is the reference solution enshrined in the French law for the long-term management of high-level radioactive waste. The current project is led by Andra, the French radioactive waste management organization. As a technical support organization, IRSN's mission is, on the basis of the safety case produced by Andra, to assess the safety of such a facility at its various stages of development, that is to say the design, construction, operation and post-closure phases of the facility. Such a facility will have to meet specific requirements, within different time frames as stated above. One of the requirements is ''reversibility'': in fact, French law poses that the geological disposal will have to be ''reversible'' for a certain time, yet not fully defined. Reversibility is nevertheless believed encompassing both the decision making process related to the waste emplacement process during operational phase and the ability to retrieve waste, should such a decision be made. Thus, underground structures have to be designed and operated to allow both waste emplacement and removal. Moreover, future decision making about the disposal process will have to rely on a sound technical basis. This implies a data collection scheme and a monitoring program of the facility to check if the disposal process is bound by limits, controls and conditions compatible with (i) a safe operation of the facility and (ii) the state of the facility that the operator wants to achieve at the time of its closure, so that long-term safety is guaranteed. Therefore, technical criteria and key parameters have to be selected and monitored during construction and operation, that is to say for decades. Then, reversibility have to make room for corrective actions, including the retrieval of waste, if something goes wrong and especially if the facility is not seen as safe anymore, especially in the perspective of long-term safety. To

  18. Vitrification treatment options for disposal of greater-than-Class-C low-level waste in a deep geologic repository

    International Nuclear Information System (INIS)

    Fullmer, K.S.; Fish, L.W.; Fischer, D.K.

    1994-11-01

    The Department of Energy (DOE), in keeping with their responsibility under Public Law 99-240, the Low-Level Radioactive Waste Policy Amendments Act of 1985, is investigating several disposal options for greater-than-Class C low-level waste (GTCC LLW), including emplacement in a deep geologic repository. At the present time vitrification, namely borosilicate glass, is the standard waste form assumed for high-level waste accepted into the Civilian Radioactive Waste Management System. This report supports DOE's investigation of the deep geologic disposal option by comparing the vitrification treatments that are able to convert those GTCC LLWs that are inherently migratory into stable waste forms acceptable for disposal in a deep geologic repository. Eight vitrification treatments that utilize glass, glass ceramic, or basalt waste form matrices are identified. Six of these are discussed in detail, stating the advantages and limitations of each relative to their ability to immobilize GTCC LLW. The report concludes that the waste form most likely to provide the best composite of performance characteristics for GTCC process waste is Iron Enriched Basalt 4 (IEB4)

  19. Public involvement in the siting of contentious facilities; Lessons from the radioactive waste repository siting programmes in Canada and the United States, with special reference to the Swedish repository siting process

    International Nuclear Information System (INIS)

    Richardson, P.J.

    1997-08-01

    This report describes the conclusion of a two-part programme, begun in 1994 with the overall aim of assisting in the development of an acceptable public participation strategy for use in Sweden for the siting of contentious facilities, with particular reference to the ongoing siting programme for a deep repository for spent nuclear fuel. The first part of the work programme, a global review of siting practice, was reported as SSI Rapport 94-15, in November 1994. This recommended further detailed studies of at least two individual programmes, which have now been carried out in Canada and the United States, and are reported on here. They involved face to face meetings with many of the main stake holders in the two programmes and enabled valuable insight to be gained into the potential problems associated with increased public participation, as well as identifying good practice where it exists. The lessons learned have then been applied to the evolving repository siting process in Sweden. 35 refs

  20. Public involvement in the siting of contentious facilities; Lessons from the radioactive waste repository siting programmes in Canada and the United States, with special reference to the Swedish repository siting process

    Energy Technology Data Exchange (ETDEWEB)

    Richardson, P J [Geosciences for Development and the Environment (United Kingdom)

    1997-08-01

    This report describes the conclusion of a two-part programme, begun in 1994 with the overall aim of assisting in the development of an acceptable public participation strategy for use in Sweden for the siting of contentious facilities, with particular reference to the ongoing siting programme for a deep repository for spent nuclear fuel. The first part of the work programme, a global review of siting practice, was reported as SSI Rapport 94-15, in November 1994. This recommended further detailed studies of at least two individual programmes, which have now been carried out in Canada and the United States, and are reported on here. They involved face to face meetings with many of the main stake holders in the two programmes and enabled valuable insight to be gained into the potential problems associated with increased public participation, as well as identifying good practice where it exists. The lessons learned have then been applied to the evolving repository siting process in Sweden. 35 refs.

  1. Siting regions for deep geological repositories. Why just here?; Standortgebiete fuer geologische Tiefenlager. Warum gerade hier?

    Energy Technology Data Exchange (ETDEWEB)

    Rieser, A

    2009-09-15

    This report helps to the popularization of the Nagra works accomplished for the management and disposal of the radioactive wastes in Switzerland. The programme for management and disposal of the radioactive wastes are extensively determined by regulations. Protection of mankind and environment is the primary objective. The basic storage process is considered as having been solved. The question addressed in the report is where the facility has to be built; the site selection procedure includes five steps: 1) according to their type the wastes have to be allocated to two different repositories: for low- and intermediate-level wastes (L/ILW), and for high-level and alpha-toxic wastes (HLW); 2) the safety concept for both repositories and the requirements on the geology have to be determined; 3) large suitable geological-tectonic zones must be found where repositories could be built; 4) in these geological zones a suitable host rock has to be identified; 5) the most important spatial geological conditions of the host rock (minimum depth with respect to surface erosion, maximum depth in terms of engineering requirements, lateral extent) have to be identified. Based on these criteria, three suitable siting regions for a HLW repository were found in the North of Switzerland. The preferred host rock is Opalinus clay because of its very low permeability; it is therefore an excellent barrier against nuclide transport. In the three proposed siting regions, Opalinus clay is present in sufficient volumes at a suitable depth. For a L/ILW repository six different possible siting regions were identified, five in Northern Switzerland and one in Central Switzerland. In the three siting regions found for a possible HLW repository, it would also be possible to built a combined repository for both HLW and L/ILW wastes.

  2. Concerted action on the retrievability of long lived radioactive waste in deep underground repositories - progress to date

    International Nuclear Information System (INIS)

    Dodd, D.H.

    2000-01-01

    Within the EURATOM Framework Programme: Nuclear Fission Safety, a Concerted Action on the retrievability of long lived radioactive waste in deep underground repositories is being carried out. This Concerted Action commenced on the 1st of January 1998 and involves experts from nine different European countries. The Concerted Action will be completed by the 31st of December 1999. This paper gives a brief overview of the objectives of the Concerted Action, the work programme that has been defined to meet these objectives, the work performed to date, and the remaining work programme. (author)

  3. Construction and Operation of a Deep Geological Spent Fuel Repository in Sweden; Some Regulatory Aspects and Challenges

    International Nuclear Information System (INIS)

    Hedberg, Bengt

    2014-01-01

    The implementation of a deep geological spent fuel disposal concept in Sweden poses challenges on both implementer and regulator in many aspects. One such challenge is the application of the regulatory framework in a different situation compared to conventional process type nuclear facilities. A specific challenge in this regard is how to understand and address constraints from post-closure safety related to the construction and operation of the repository. The maybe most challenging aspect, however, is the unusually long time frame, i.e. many generations, for realization of the project. This paper addresses some of these challenges from a regulatory perspective. (authors)

  4. Seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Šílený, Jan; Lednická, Markéta

    2017-01-01

    Roč. 15, č. 1 (2017), s. 486-493 E-ISSN 2391-5471 R&D Projects: GA MŠk LM2010008; GA MŠk(CZ) LM2015079 Institutional support: RVO:68145535 ; RVO:67985530 Keywords : deep geological repository * earthquake * seismicity * neo-deterministic analysis * probabilistic seismic hazard assessment Subject RIV: DC - Siesmology, Volcanology, Earth Structure; DC - Siesmology, Volcanology, Earth Structure (GFU-E) OBOR OECD: Environmental and geological engineering, geotechnics; Environmental and geological engineering, geotechnics (GFU-E) Impact factor: 0.745, year: 2016 https://www.degruyter.com/downloadpdf/j/phys.2017.15.issue-1/phys-2017-0055/phys-2017-0055.pdf

  5. Proposed format and content of environmental reports for deep geologic terminal repositories for radioactive material

    International Nuclear Information System (INIS)

    Carrell, D.J.; Jones, G.L.

    1978-01-01

    As the Nuclear Regulatory Commission has not yet issued a format guide for the preparation of an environmental impact statement for radioactive waste repositories, Rockwell Hanford operations has developed an annotated outline which will serve as the basis for the environmental evaluation activities until replaced by an appropriate NRC regulatory guide. According to the outline, the applicant should summarize the major environmental effects that are expected to occur during the construction, operation, and terminal isolation phases of the radioactive material repository. Compare these environmental effects with the possible effect of continued use of interim storage facilities. Unless unforeseen environmental effects become apparent, the summary should be a positive statement indicating that the short-term environmental effects are outweighed by the long-term benefits of the repository

  6. Heat propagation in and around the deep repository. Thermal calculations applied to three hypothetical sites: Aberg, Beberg and Ceberg

    International Nuclear Information System (INIS)

    Ageskog, L.; Jansson, Patrik

    1999-01-01

    The purpose of the present study is to demonstrate the modelling of the thermal process in and around the deep repository for spent fuel. The model was developed in the general finite element program ANSYS and applied to the three hypothetical sites Aberg, Beberg and Ceberg included in the SR 97 analyse system. The canister emplacement in the repository was analysed based on certain criteria regarding the temperature on the canister surface. This was done with consideration to natural deviations in various thermal parameters as well as to the risk of a gap opening up between the canister surface and the bentonite buffer. The consequence of the latter was analysed separately as part of the study. The heat load in the model was applied stepwise, following an assumed time schedule for the actual deposition work. The calculations were extended to 1,000 years after the commencement of the deposition work. The outcome of the calculation is presented as coloured prints of isotherms in and around the repository at certain time intervals

  7. Modelling of processes occurring in deep geological repository - development of new modules in the GoldSim environment

    International Nuclear Information System (INIS)

    Vopalka, D.; Lukin, D.; Vokal, A.

    2006-01-01

    Three new modules modelling the processes that occur in a deep geological repository have been prepared in the GoldSim computer code environment (using its Transport Module). These modules help to understand the role of selected parameters in the near-field region of the final repository and to prepare an own complex model of the repository behaviour. The source term module includes radioactive decay and ingrowth in the canister, first order degradation of fuel matrix, solubility limitation of the concentration of the studied nuclides, and diffusive migration through the surrounding bentonite layer controlled by the output boundary condition formulated with respect to the rate of water flow in the rock. The corrosion module describes corrosion of canisters made of carbon steel and transport of corrosion products in the near-field region. This module computes balance equations between dissolving species and species transported by diffusion and/or advection from the surface of a solid material. The diffusion module that includes also non-linear form of the interaction isotherm can be used for an evaluation of small-scale diffusion experiments. (author)

  8. Modelling of processes occurring in deep geological repository - Development of new modules in the GoldSim environment

    Science.gov (United States)

    Vopálka, D.; Lukin, D.; Vokál, A.

    2006-01-01

    Three new modules modelling the processes that occur in a deep geological repository have been prepared in the GoldSim computer code environment (using its Transport Module). These modules help to understand the role of selected parameters in the near-field region of the final repository and to prepare an own complex model of the repository behaviour. The source term module includes radioactive decay and ingrowth in the canister, first order degradation of fuel matrix, solubility limitation of the concentration of the studied nuclides, and diffusive migration through the surrounding bentonite layer controlled by the output boundary condition formulated with respect to the rate of water flow in the rock. The corrosion module describes corrosion of canisters made of carbon steel and transport of corrosion products in the near-field region. This module computes balance equations between dissolving species and species transported by diffusion and/or advection from the surface of a solid material. The diffusion module that includes also non-linear form of the interaction isotherm can be used for an evaluation of small-scale diffusion experiments.

  9. Constructability analysis for a deep repository - some thoughts on possibilities and limitations

    International Nuclear Information System (INIS)

    Baeckblom, G.; Leijon, B.; Stille, H.

    1995-01-01

    Potential site characterization for construction of a repository for geologic disposal of spent fuel in crystalline rock in Sweden is discussed. The present plan requires that the fuel be encapsulated in a composite steel-copper canister, that the repository be situated somewhere in Sweden with municipal approval, and that licensing be preceded by extensive studies and investigations. Important factors are mechanical stability, hydrology, and the suitability of construction materials. Site investigation will require a lot of surface and borehole information regarding rock types, zones, structures, fractures, hydraulic conductivity, stresses, rock strength, and groundwater chemistry. 6 refs., 4 tabs., 1 fig

  10. Long-term degradation of organic polymers under conditions found in deep repositories for low and intermediate-level wastes

    International Nuclear Information System (INIS)

    Warthmann, R.; Mosberger, L.; Baier, U.

    2013-06-01

    On behalf of Nagra, the Environmental Biotechnology Section of the Zürich University of Applied Sciences in Wädenswil investigated the potential for microbiological degradation of organic polymers under the conditions found in a deep geological repository for low- and intermediate-level waste (L/ILW). The existing scientific literature on the topic was analysed, some thermodynamic calculations carried out and input was elicited from internationally recognised experts in the field. The study was restricted to a few substances which, in terms of mass, are most significant in the Swiss L/ILW inventory; these are polystyrene (PS), polyvinyl chloride (PVC), other plastics and bitumen. There were no clear indications in the literature that the polymer structure of synthetic polymers is biodegraded under anoxic conditions. However, functional groups of ion exchangers and plasticizers in plastics are considered to be readily available and biodegradable. The greatest obstacle to biological degradation of synthetic polymers is depolymerisation to produce labile monomers. As energy is generally required for such breakdown, the chances of this process taking place outside the cells are very low. In so far as they are present, monomers are, in principle, anaerobically biodegradable. Thermodynamic considerations indicate that degradation of synthetic polymers under repository conditions is theoretically possible. However, the degradation of polystyrene is very close to thermodynamic equilibrium and the usable energy for microorganisms would barely be sufficient. Under high H2 partial pressures, it is predicted that there will be a thermodynamic inhibition of anaerobic degradation, as certain interim steps in degradation are endergonic. The starting conditions for microbial growth in a deep repository are unfavourable in terms of availability of water and prevailing pH values. Practically no known microorganisms can tolerate the combination of these conditions; most known

  11. Efficiency analyses of the CANDU spent fuel repository using modified disposal canisters for a deep geological disposal system design

    International Nuclear Information System (INIS)

    Lee, J.Y.; Cho, D.K.; Lee, M.S.; Kook, D.H.; Choi, H.J.; Choi, J.W.; Wang, L.M.

    2012-01-01

    Highlights: ► A reference disposal concept for spent nuclear fuels in Korea has been reviewed. ► To enhance the disposal efficiency, alternative disposal concepts were developed. ► Thermal analyses for alternative disposal concepts were performed. ► From the result of the analyses, the disposal efficiency of the concepts was reviewed. ► The most effective concept was suggested. - Abstract: Deep geological disposal concept is considered to be the most preferable for isolating high-level radioactive waste (HLW), including nuclear spent fuels, from the biosphere in a safe manner. The purpose of deep geological disposal of HLW is to isolate radioactive waste and to inhibit its release of for a long time, so that its toxicity does not affect the human beings and the biosphere. One of the most important requirements of HLW repository design for a deep geological disposal system is to keep the buffer temperature below 100 °C in order to maintain the integrity of the engineered barrier system. In this study, a reference disposal concept for spent nuclear fuels in Korea has been reviewed, and based on this concept, efficient alternative concepts that consider modified CANDU spent fuels disposal canister, were developed. To meet the thermal requirement of the disposal system, the spacing of the disposal tunnels and that of the disposal pits for each alternative concept, were drawn following heat transfer analyses. From the result of the thermal analyses, the disposal efficiency of the alternative concepts was reviewed and the most effective concept suggested. The results of these analyses can be used for a deep geological repository design and detailed analyses, based on exact site characteristics data, will reduce the uncertainty of the results.

  12. Process for selecting a site for Canada's deep geological repository for used nuclear fuel

    International Nuclear Information System (INIS)

    Facella, J.; Belfadhel, M.B.

    2011-01-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management, the approach selected by the Government of Canada for long-term management of used nuclear fuel waste generated by Canadian nuclear reactors. The ultimate objective of Adaptive Phased Management is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable crystalline or sedimentary rock formation at a depth of about 500m. The repository will consist of a series of access and service shafts and a series of tunnels leading to placement rooms where used fuel will be placed and sealed in competent rock using a multi-barrier system which includes long lived specially designed containers, sealing materials such as bentonite and the rock itself. The used fuel will be monitored throughout all phases of implementation and will also remain retrievable for an extended period of time. In May 2010, the NWMO published the site selection process that serves as the road map to decision-making on the location for the deep geological repository. NWMO initiated the process with a first stage that invites communities to learn more about the project and the site selection process. NWMO is actively building awareness of the project and, on request of communities, is delivering briefings, supporting community capacity building and undertaking high-level screenings of site suitability. The paper provides a brief description of: Adaptive Phased Management including the deep geological repository which is its ultimate goal, and the design of the site selection process, and importantly the approach to assessing the suitability of sites from both a social and technical perspective. The paper will outline how NWMO sought to develop a socially-acceptable site selection process as a firm foundation for future decisions on siting. Through a two-year collaborative process, NWMO sought to understand the expectations of

  13. Deep repository - Engineered barrier system. Erosion and sealing processes in tunnel backfill materials investigated in laboratory

    Energy Technology Data Exchange (ETDEWEB)

    Sanden, Torbjoern; Boergesson, Lennart; Dueck, Ann; Goudarzi, Reza; Loennqvist, Margareta (Clay Technology AB, Lund (Sweden))

    2008-12-15

    SKB in Sweden and Posiva in Finland are developing and plan to implement similar disposal concepts for the final disposal of spent nuclear fuel. Co-operation and joint development work between Posiva and SKB with the overall objective to develop backfill concepts and techniques for sealing and closure of the repository have been going on for several years. The investigation described in this report is intended to acquire more knowledge regarding the behavior of some of the candidate backfilling materials. Blocks made of three different materials (Friedland clay, Asha 230 or a bentonite/ballast 30/70 mixture) as well as different bentonite pellets have been examined. The backfill materials will be exposed to an environment simulating that in a tunnel, with high relative humidity and water inflow from the rock. The processes and properties investigated are: 1. Erosion properties of blocks and pellets (Friedland blocks, MX-80 pellets, Cebogel QSE pellets, Minelco and Friedland granules). 2. Displacements of blocks after emplacement in a deposition drift (Blocks of Friedland, Asha 230 and Mixture 30/70). 3. The ability of these materials to seal a leaking in-situ cast plug cement/rock but also other fractures in the rock (MX-80 pellets). 4. The self healing ability after a piping scenario (Blocks of Friedland, Asha 230 Mixture 30/70 and also MX-80 pellets). 5. Swelling and cracking of the compacted backfill blocks caused by relative humidity. The erosion properties of Friedland blocks were also investigated in Phase 2 of the joint SKBPosiva project 'Backfilling and Closure of the Deep Repository, BACLO, which included laboratory scale experiments. In this phase of the project (3) some completing tests were performed with new blocks produced for different field tests. These blocks had a lower density than intended and this has an influence on the erosion properties measured. The erosion properties of MX-80 pellets were also investigated earlier in the project but

  14. Siting, design and construction of a deep geological repository for the disposal of high level and alpha bearing wastes

    International Nuclear Information System (INIS)

    1990-06-01

    The main objective of this document is to summarize the basic principles and approaches to siting, design and construction of a deep geological repository for disposal of high level and alpha bearing radioactive wastes, as commonly agreed upon by Member States. This report is addressed to decision makers and technical managers as well as to specialists planning for siting, design and construction of geological repositories for disposal of high level and alpha bearing wastes. This document is intended to provide Member States of the IAEA with a summary outline for the responsible implementing organizations to use for siting, designing and constructing confinement systems for high level and alpha bearing radioactive waste in accordance with the protection objectives set by national regulating authorities or derived from safety fundamentals and standards of the IAEA. The protection objectives will be achieved by the isolation of the radionuclides from the environment by a repository system, which consists of a series of man made and natural safety barriers. Engineered barriers are used to enhance natural geological containment in a variety of ways. They must complement the natural barriers to provide adequate safety and necessary redundancy to the barrier system to ensure that safety standards are met. Because of the long timescales involved and the important role of the natural barrier formed by the host rock, the site selection process is a key activity in the repository design and development programme. The choice of the site, the investigation of its geological setting, the exploration of the regional hydrogeological setting and the primary underground excavations are all considered to be part of the siting process. 16 refs

  15. Canada's Deep Geological Repository for Used Nuclear Fuel - Geo-scientific Site Evaluation Process - 13117

    Energy Technology Data Exchange (ETDEWEB)

    Blyth, Alec; Ben Belfadhel, Mahrez; Hirschorn, Sarah; Hamilton, Duncan; McKelvie, Jennifer [Nuclear Waste Management Organization, 22 St. Clair Avenue East, Toronto, Ontario M4T 2S3 (Canada)

    2013-07-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable rock formation at a depth of approximately 500 meters (m) (1,640 feet [ft]). In May 2010, the NWMO published a nine-step site selection process that serves as the road map to decision-making on the location for the deep geological repository. The safety and appropriateness of any potential site will be assessed against a number of factors, both technical and social in nature. The selected site will be one that can be demonstrated to be able to safely contain and isolate used nuclear fuel, protecting humans and the environment over the very long term. The geo-scientific suitability of potential candidate sites will be assessed in a stepwise manner following a progressive and thorough site evaluation process that addresses a series of geo-scientific factors revolving around five safety functions. The geo-scientific site evaluation process includes: Initial Screenings; Preliminary Assessments; and Detailed Site Evaluations. As of November 2012, 22 communities have entered the site selection process (three in northern Saskatchewan and 18 in northwestern and southwestern Ontario). (authors)

  16. Seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel

    Science.gov (United States)

    Kaláb, Zdeněk; Šílený, Jan; Lednická, Markéta

    2017-07-01

    This paper deals with the seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel in the Czech Republic. The basic source of data for historical earthquakes up to 1990 was the seismic website [1-]. The most intense earthquake described occurred on September 15, 1590 in the Niederroesterreich region (Austria) in the historical period; its reported intensity is Io = 8-9. The source of the contemporary seismic data for the period since 1991 to the end of 2014 was the website [11]. It may be stated based on the databases and literature review that in the period from 1900, no earthquake exceeding magnitude 5.1 originated in the territory of the Czech Republic. In order to evaluate seismicity and to assess the impact of seismic effects at depths of hypothetical deep geological repository for the next time period, the neo-deterministic method was selected as an extension of the probabilistic method. Each one out of the seven survey areas were assessed by the neo-deterministic evaluation of the seismic wave-field excited by selected individual events and determining the maximum loading. Results of seismological databases studies and neo-deterministic analysis of Čihadlo locality are presented.

  17. Proposed format and content of license applications for deep geologic terminal repositories for radioactive material

    International Nuclear Information System (INIS)

    1978-01-01

    Chapters are devoted to the following: introduction and general description; summary safety analysis; site characteristics; principal design criteria; repository design; operations systems; management of onsite generated waste; radiation protection; accident safety analysis; conduct of operations; operating controls and limits; and quality assurance

  18. Setting up a safe deep repository for long-lived HLW and ILW in Russia: Current state of the works

    International Nuclear Information System (INIS)

    Polyakov, Yu.D.; Porsov, A.Yu.; Beigul, V.P.; Palenov, M.V.

    2014-01-01

    The concept of RW disposal in Russia in accordance with the Federal Law 'On Radioactive Waste Management and Amendments to Specific Legal Acts of the Russian Federation' No. 190-FL dated 11 July 2011, is oriented at the ultimate disposal of waste, without an intent for their subsequent retrieval. The law 190-FL has it as follows: - A radioactive waste repository is a radioactive waste storage facility intended for disposal of the radioactive wastes without an intent for their subsequent retrieval. - Disposal of solid long-lived high-level waste and solid long-lived intermediate-level waste is carried out in deep repositories for radioactive waste. - Import into the Russian Federation of radioactive waste for the purpose of its storage, processing and disposal, except for spent sealed sources of ionising radiation originating from the Russian Federation, is prohibited. For safe final disposal of long-lived HLW and ILW, it is planned to construct a deep repository for radioactive waste (DRRW) in a low-pervious monolith rock massif in the Krasnoyarsk region in the production territory of the Mining and Chemical Combine (FSUE 'Gorno-khimicheskiy kombinat'). According to the IAEA recommendations and in line with the international experience in feasibility studies for setting up of HLW and SNF underground disposal facilities, the first mandatory step is the construction of an underground research laboratory. An underground laboratory serves the following purposes: - itemised research into the characteristics of enclosing rock mass, with verification of massive material suitability for safe disposal of long-lived HLW and ILW; - research into and verification of the isolating properties of an engineering barrier system; - development of engineering solutions and transportation and process flow schemes for construction and running of a future RW ultimate isolation facility. (authors)

  19. Sectoral Plan 'Deep Geological Disposal', Stage 2. Proposed site areas for the surface facilities of the deep geological repositories as well as for their access infrastructure. Annexes

    International Nuclear Information System (INIS)

    2011-12-01

    In line with the provisions of the nuclear energy legislation, the sites for deep geological disposal of Swiss radioactive waste are selected in a three-stage Sectoral Plan process (Sectoral Plan for Deep Geological Disposal). The disposal sites are specified in Stage 3 of the selection process with the granting of a general licence in accordance with the Nuclear Energy Act. The first stage of the process was completed on 30 th November 2011, with the decision of the Federal Council to incorporate the six geological siting regions proposed by the National Cooperative for the Disposal of Radioactive Waste (NAGRA) into the Sectoral Plan for Deep Geological Disposal, for further evaluation in Stage 2. The decision also specifies the planning perimeters within which the surface facilities and shaft locations for the repositories will be constructed. In the second stage of the process, at least two geological siting regions each will be specified for the repository for low- and intermediate-level waste (L/ILW) and for the high-level waste (HLW) repository and these will undergo detailed geological investigation in Stage 3. For each of these potential siting regions, at least one location for the surface facility and a corridor for the access infrastructure will also be specified. NAGRA is responsible, at the beginning of Stage 2, for submitting proposals for potential locations for the surface facilities and their access infrastructure to the Federal Office of Energy (SFOE); these are then considered by the regional participation bodies in the siting regions. The general report and the present annexes volume document these proposals. In Stage 2, under the lead of the SFOE, socio-economic-ecological studies will also be carried out to investigate the impact of a repository project on the environment, economy and society. The present reports also contain the input data to be provided by NAGRA for the generic (site-independent) part of these impact studies. A meaningful

  20. International Atomic Energy Agency (IAEA) initiatives: Records management for deep and near surface geologic repositories

    International Nuclear Information System (INIS)

    Warner, P.J.

    1996-01-01

    The international scientific community has long had an interest in determining methods by which information regarding nuclear waste repositories, and the inherent danger to humanity, could be passed from generation to generation and society to society. Because nuclear waste will remain radioactive for thousands of years future generations must be warned of the dangers thus eliminating intentional or inadvertent intrusion. Member States of the IAEA have determined that the principle safety of such sites must not rely solely on long term institutional arrangements for the retention of information. It is believed that repository siting, design, operation and postoperation information should be gathered, managed and retained so that this information remains accessible to future societies over a very long period of time. The radionuclide life is 10,000 years; thus the retention of information continues beyond current societies, cultures and languages, and must be continually migrated to new retrieval technologies to assure access

  1. Establishing deep geological repositories for radioactive waste in the United States of America

    International Nuclear Information System (INIS)

    Bennett, J.W.; Ballard, W.W. Jr.; Cooley, C.R.

    1984-01-01

    The paper describes, in broad terms, the interrelationship of the several regulations and recent legislation governing the National Waste Terminal Storage programme. The schedules of the first and second repositories are detailed, as are the interactions between the federal, state, and local governments. Limited portions of the Nuclear Regulatory Commission's regulations and the Environmental Protection Agency's standard are discussed to the extent that they affect the development schedules. (author)

  2. Sectoral Plan 'Deep Geological Disposal', Stage 2. Proposed site areas for the surface facilities of the deep geological repositories as well as for their access infrastructure. General report

    International Nuclear Information System (INIS)

    2011-12-01

    In line with the provisions of the nuclear energy legislation, the sites for deep geological disposal of Swiss radioactive waste are selected in a three-stage Sectoral Plan process (Sectoral Plan for Deep Geological Disposal). The disposal sites are specified in Stage 3 of the selection process with the granting of a general licence in accordance with the Nuclear Energy Act. The first stage of the process was completed on 30 th November 2011, with the decision of the Federal Council to incorporate the six geological siting regions proposed by the National Cooperative for the Disposal of Radioactive Waste (NAGRA) into the Sectoral Plan for Deep Geological Disposal, for further evaluation in Stage 2. The decision also specifies the planning perimeters within which the surface facilities and shaft locations for the repositories will be constructed. In the second stage of the process, at least two geological siting regions each will be specified for the repository for low- and intermediate-level waste (L/ILW) and for the high-level waste (HLW) repository and these will undergo detailed geological investigation in Stage 3. For each of these potential siting regions, at least one location for the surface facility and a corridor for the access infrastructure will also be specified. NAGRA is responsible, at the beginning of Stage 2, for submitting proposals for potential locations for the surface facilities and their access infrastructure to the Federal Office of Energy (SFOE); these are then considered by the regional participation bodies in the siting regions. The present report and its annexes volume document these proposals. In Stage 2, under the lead of the SFOE, socio-economic-ecological studies will also be carried out to investigate the impact of a repository project on the environment, economy and society. The present reports also contain the input data to be provided by NAGRA for the generic (site-independent) part of these impact studies. A meaningful discussion

  3. Low-pH injection grout for deep repositories. Summary report from a co-operation project between NUMO (Japan), Posiva (Finland) and SKB (Sweden)

    International Nuclear Information System (INIS)

    Boden, Anders; Sievaenen, Ursula

    2005-06-01

    The use of standard cementitious material creates pulses of pH in the magnitude of 12-13 in the leachates and release alkalis. Such a high pH is detrimental and also unnecessarily complicates the safety analysis of the repository. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis. Also, according to current understanding, the use of low-pH cement (pH = 11) will not disturb the functioning of the bentonite, although limiting the amount of low-pH cement is recommended. A result of the project is that there are both low-pH cementitious material for grouting larger fractures (= 100 μm) and non-cementitious material for grouting smaller fractures (< 100 μm) that will, after further optimisation work, be recommended for grouting of deep repositories. This project concentrated on the technical development of properties for the low pH grouts. Long-term safety and environmental aspects and durability of materials were preliminarily considered. Continued evaluations have to be carried out. Five systems, e.g. material combinations, were studied in the project: 1. Ordinary Portland Cement + Silica Fume. 'OPC+SF' denotes a binder system that is based mainly on OPC+SF. SF was used in a few commercial forms. The OPC used in this system was mainly UF16 and in some cases Rheocem 900 or white cement. 2. Blast furnace slag. 'Slag' denotes an OPC activated slag based system. Alkali and water glass activation were not examined, because of long-term safety reasons. OPC used in this system was rapid hardening Portland cement. 3. Super sulphate cement. 'SSC' is a slag-based system activated with gypsum and OPC. The OPC used was rapid hardening Portland cement and the gypsum was a very fine grained slurry product. 4. Low-Alkali Cement 'LAC' was introduced to the project by NUMO as a product, ground to fixed fineness by the producer. Neither the mineral composition nor fineness, were modified in the present

  4. Low-pH injection grout for deep repositories. Summary report from a co-operation project between NUMO (Japan), Posiva (Finland) and SKB (Sweden)

    Energy Technology Data Exchange (ETDEWEB)

    Boden, Anders [SwedPower AB, Stockholm (Sweden); Sievaenen, Ursula [JP-Suoraplan Oy, Vantaa (Finland)

    2005-06-01

    The use of standard cementitious material creates pulses of pH in the magnitude of 12-13 in the leachates and release alkalis. Such a high pH is detrimental and also unnecessarily complicates the safety analysis of the repository. As no reliable pH-plume models exist, the use of products giving a pH below 11 in the leachates facilitates the safety analysis. Also, according to current understanding, the use of low-pH cement (pH = 11) will not disturb the functioning of the bentonite, although limiting the amount of low-pH cement is recommended. A result of the project is that there are both low-pH cementitious material for grouting larger fractures (= 100 {mu}m) and non-cementitious material for grouting smaller fractures (< 100 {mu}m) that will, after further optimisation work, be recommended for grouting of deep repositories. This project concentrated on the technical development of properties for the low pH grouts. Long-term safety and environmental aspects and durability of materials were preliminarily considered. Continued evaluations have to be carried out. Five systems, e.g. material combinations, were studied in the project: 1. Ordinary Portland Cement + Silica Fume. 'OPC+SF' denotes a binder system that is based mainly on OPC+SF. SF was used in a few commercial forms. The OPC used in this system was mainly UF16 and in some cases Rheocem 900 or white cement. 2. Blast furnace slag. 'Slag' denotes an OPC activated slag based system. Alkali and water glass activation were not examined, because of long-term safety reasons. OPC used in this system was rapid hardening Portland cement. 3. Super sulphate cement. 'SSC' is a slag-based system activated with gypsum and OPC. The OPC used was rapid hardening Portland cement and the gypsum was a very fine grained slurry product. 4. Low-Alkali Cement 'LAC' was introduced to the project by NUMO as a product, ground to fixed fineness by the producer. Neither the mineral composition nor

  5. Role of waste packages in the safety of a high level waste repository in a deep geological formation

    International Nuclear Information System (INIS)

    Bretheau, F.; Lewi, J.

    1990-06-01

    The safety of a radioactive waste disposal facility lays on the three following barriers placed between the radioactive materials and the biosphere: the waste package; the engineered barriers; the geological barrier. The function assigned to each of these barriers in the performance assessment is an option taken by the organization responsible for waste disposal management (ANDRA in France), which must show that: expected performances of each barrier (confinement ability, life-time, etc.) are at least equal to those required to fulfill the assigned function; radiation protection requirements are met in all situations considered as credible, whether they be the normal situation or random event situations. The French waste management strategy is based upon two types of disposal depending on the nature and activity of waste packages: - surface disposal intended for low and medium level wastes having half-lives of about 30 years or less and alpha activity less than 3.7 MBq/kg (0.1 Ci/t), for individual packages and less than 0.37 MBq/kg (0.01 Ci/t) in the average. Deep geological disposal intended for TRU and high level wastes. The conditions of acceptance of packages in a surface disposal site are subject to the two fundamental safety rules no. I.2 and III.2.e. The present paper is only dealing with deep geological disposal. For deep geological repositories, three stages are involved: stage preceding definitive disposal (intermediate storage, transportation, handling, setting up in the disposal cavities); stage subsequent to definitive sealing of the disposal cavities but prior to the end of operation of the repository; stage subsequent to closure of the repository. The role of the geological barrier has been determined as the essential part of long term radioactivity confinement, by a working group, set up by the French safety authorities. Essential technical criteria relating to the choice of a site so defined by this group, are the following: very low permeability

  6. Ontario Power Generation's proposed L and ILW deep geologic repository : an overview of geoscientific studies

    Energy Technology Data Exchange (ETDEWEB)

    Jensen, M; Lam, T.; Luhowy, D.; McLay, J.; Semec, B.; Frizzell, R. [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2009-07-01

    This paper reported on a multi-disciplinary geoscientific study to confirm the suitability of storing low and intermediate level radioactive waste in a deep geologic repository (DGR). The study is being conducted by the Nuclear Waste Management Organization on behalf of Ontario Power Generation (OPG). The DGR would involve the excavation of waste emplacement rooms within the Ordovician age argillaceous limestones 680 m beneath OPG's Bruce site near Tiverton, Ontario. The repository would require the excavation of nearly 890,000 m{sup 3} of rock to accommodate 200,000 m{sup 3} of radioactive waste within a 28 Ha repository footprint. A concrete floor will be poured to provide a stable base for stacking the waste packages. The first phase of the geoscientific site characterisation plan (GSCP) was prepared in 2005. The GSCP provides a comprehensive and internationally peer-reviewed basis for DGR-related geoscientific studies. The GSCP describes surface and sub-surface site characterization activities required to evaluate the technical suitability of the proposed DGR concept. The GSCP also provides a geoscientific basis for the post-closure safety assessment and contributes to the development of an integrated DGR safety case describing the expected long-term safety and potential impacts of the DGR. Interim results have shown that the middle-upper Ordovician formations proposed to host and enclose the DGR comprise a stable, saline and extremely low permeability groundwater regime. This paper provided an overview of the coordinated site-specific and regional studies to characterize the Bruce site and support the DGR safety case. The work program is scheduled for completion in late 2010 in support of the submittal of an Environmental Impact Statement and regulatory site Preparation/Construction License application in early 2011. 17 refs., 8 figs.

  7. Multi-dimensional transport modelling of corrosive agents through a bentonite buffer in a Canadian deep geological repository.

    Science.gov (United States)

    Briggs, Scott; McKelvie, Jennifer; Sleep, Brent; Krol, Magdalena

    2017-12-01

    The use of a deep geological repository (DGR) for the long-term disposal of used nuclear fuel is an approach currently being investigated by several agencies worldwide, including Canada's Nuclear Waste Management Organization (NWMO). Within the DGR, used nuclear fuel will be placed in copper-coated steel containers and surrounded by a bentonite clay buffer. While copper is generally thermodynamically stable, corrosion can occur due to the presence of sulphide under anaerobic conditions. As such, understanding transport of sulphide through the engineered barrier system to the used fuel container is an important consideration in DGR design. In this study, a three-dimensional (3D) model of sulphide transport in a DGR was developed. The numerical model is implemented using COMSOL Multiphysics, a commercial finite element software package. Previous sulphide transport models of the NWMO repository used a simplified one-dimensional system. This work illustrates the importance of 3D modelling to capture non-uniform effects, as results showed locations of maximum sulphide flux are 1.7 times higher than the average flux to the used fuel container. Copyright © 2017. Published by Elsevier B.V.

  8. Review of excavation methods and their implications for the near-field barrier of a deep underground repository

    International Nuclear Information System (INIS)

    Young, D.K.

    1993-01-01

    The report reviews excavation techniques for use in the construction of deep underground radioactive waste repositories, gives a summary of responses of the host rock to excavation and the means of measuring that response and discusses techniques for predicting that response. The review of excavation techniques included technical developments and current practice. To this end an extensive database was developed reviewing major excavations in rock types relevant to disposal and the techniques employed. Creation of an underground opening alters the properties of the rock mass around it. This study identifies stress, displacement, rock mass deformability and permeability as key parameters and reviews how they may be determined. Finally the report discusses the techniques available for predicting the behaviour of the near-field host rock. This concentrates on methods of numerical analysis since existing empirical or analytical methods are not considered suitable. (author)

  9. Seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel

    Directory of Open Access Journals (Sweden)

    Kaláb Zdeněk

    2017-07-01

    Full Text Available This paper deals with the seismic stability of the survey areas of potential sites for the deep geological repository of the spent nuclear fuel in the Czech Republic. The basic source of data for historical earthquakes up to 1990 was the seismic website [10]. The most intense earthquake described occurred on September 15, 1590 in the Niederroesterreich region (Austria in the historical period; its reported intensity is Io = 8-9. The source of the contemporary seismic data for the period since 1991 to the end of 2014 was the website [11]. It may be stated based on the databases and literature review that in the period from 1900, no earthquake exceeding magnitude 5.1 originated in the territory of the Czech Republic.

  10. Ecohydrological Responses to Diversion of Groundwater: Case Study of a Deep-Rock Repository for Spent Nuclear Fuel in Sweden

    International Nuclear Information System (INIS)

    Werner, Kent; Collinder, Per; Berglund, Sten; Maartensson, Erik

    2013-01-01

    Planning and license applications concerning groundwater diversion in areas containing water-dependent or water-favored habitats must take into account both hydrological effects and associated ecological consequences. There is at present no established methodology to assess such ecohydrological responses. Thus, this paper describes a new stepwise methodology to assess ecohydrological responses to groundwater diversion from, e.g., water-drained pits, shafts, tunnels, and caverns in rock below the groundwater table. The methodology is illustrated using the planned deep-rock repository for spent nuclear fuel at Forsmark in central Sweden as a case study, offering access to a unique hydrological and ecological dataset. The case study demonstrates that results of ecohydrological assessments can provide useful inputs to planning of monitoring programs and mitigation measures in infrastructure projects. As a result of the assessment, artificial water supply to wetlands is planned in order to preserve biological diversity, nature values, and vulnerable species

  11. Long term radiological effects on plants and animals of a deep geological repository. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Torudd, Jesper [Facilia AB (Sweden)

    2010-12-15

    This study is part of the safety assessment of the planned repository for spent nuclear fuel in Forsmark, called SR-Site. The purpose of the report is to clarify whether the environment is protected against harmful effects of ionizing radiation after a possible future release of radioactive matter from the planned repository. According to the Swedish Radiation Safety Authority (SSM), biological diversity and sustainable use of biological resources must be protected, and the evaluation should pay special attention to threatened and endemic species as well as economically and culturally valuable species. The report shows the approach to, and results of, calculations of dose rates to organisms other than man. The calculations are based on modelled activity concentrations from a potential future radioactive release, provided by a separate modelling project. Calculations were performed with the ERICA Tool, a software programme developed by an EU research project. In the ERICA Tool, dose rates for site specific organisms (i.e., occurring at the site) were calculated using input data such as size dimensions and masses of organisms, ecosystems and habitats, concentration ratios for the studied elements (i.e. the ratio of accumulated element concentration in the body compared with the element concentration in the surrounding environment) and maximum activity concentrations of radionuclides from the modelled future release. The results are provided in terms of final dose rates for each studied organism. In accordance with rationales of the International Commission of Radiological Protection (ICRP) and the ERICA project, Representative (site-specific) Organisms from the planned site of the future repository were studied. Ideally, the organisms selected would meet the criteria defined by both SSM (species worth protecting) and by ICRP and ERICA (so-called Reference Organisms). Since activity concentrations for a number of radionuclides were missing for some of the studied

  12. Long term radiological effects on plants and animals of a deep geological repository. SR-Site Biosphere

    Energy Technology Data Exchange (ETDEWEB)

    Torudd, Jesper (Facilia AB (Sweden))

    2010-12-15

    This study is part of the safety assessment of the planned repository for spent nuclear fuel in Forsmark, called SR-Site. The purpose of the report is to clarify whether the environment is protected against harmful effects of ionizing radiation after a possible future release of radioactive matter from the planned repository. According to the Swedish Radiation Safety Authority (SSM), biological diversity and sustainable use of biological resources must be protected, and the evaluation should pay special attention to threatened and endemic species as well as economically and culturally valuable species. The report shows the approach to, and results of, calculations of dose rates to organisms other than man. The calculations are based on modelled activity concentrations from a potential future radioactive release, provided by a separate modelling project. Calculations were performed with the ERICA Tool, a software programme developed by an EU research project. In the ERICA Tool, dose rates for site specific organisms (i.e., occurring at the site) were calculated using input data such as size dimensions and masses of organisms, ecosystems and habitats, concentration ratios for the studied elements (i.e. the ratio of accumulated element concentration in the body compared with the element concentration in the surrounding environment) and maximum activity concentrations of radionuclides from the modelled future release. The results are provided in terms of final dose rates for each studied organism. In accordance with rationales of the International Commission of Radiological Protection (ICRP) and the ERICA project, Representative (site-specific) Organisms from the planned site of the future repository were studied. Ideally, the organisms selected would meet the criteria defined by both SSM (species worth protecting) and by ICRP and ERICA (so-called Reference Organisms). Since activity concentrations for a number of radionuclides were missing for some of the studied

  13. Long term radiological effects on plants and animals of a deep geological repository. SR-Site Biosphere

    International Nuclear Information System (INIS)

    Torudd, Jesper

    2010-12-01

    This study is part of the safety assessment of the planned repository for spent nuclear fuel in Forsmark, called SR-Site. The purpose of the report is to clarify whether the environment is protected against harmful effects of ionizing radiation after a possible future release of radioactive matter from the planned repository. According to the Swedish Radiation Safety Authority (SSM), biological diversity and sustainable use of biological resources must be protected, and the evaluation should pay special attention to threatened and endemic species as well as economically and culturally valuable species. The report shows the approach to, and results of, calculations of dose rates to organisms other than man. The calculations are based on modelled activity concentrations from a potential future radioactive release, provided by a separate modelling project. Calculations were performed with the ERICA Tool, a software programme developed by an EU research project. In the ERICA Tool, dose rates for site specific organisms (i.e., occurring at the site) were calculated using input data such as size dimensions and masses of organisms, ecosystems and habitats, concentration ratios for the studied elements (i.e. the ratio of accumulated element concentration in the body compared with the element concentration in the surrounding environment) and maximum activity concentrations of radionuclides from the modelled future release. The results are provided in terms of final dose rates for each studied organism. In accordance with rationales of the International Commission of Radiological Protection (ICRP) and the ERICA project, Representative (site-specific) Organisms from the planned site of the future repository were studied. Ideally, the organisms selected would meet the criteria defined by both SSM (species worth protecting) and by ICRP and ERICA (so-called Reference Organisms). Since activity concentrations for a number of radionuclides were missing for some of the studied

  14. Biosphere modelling for a deep radioactive waste repository: site-specific consideration of the groundwater-soil pathway

    International Nuclear Information System (INIS)

    Grogan, H.A.; Baeyens, B.; Mueller, H.; Dorp, F. van

    1991-07-01

    Scenario evaluations indicate that groundwater is the most probable pathway for released radionuclides to reach the biosphere from a deep underground nuclear waste repository. This report considers a small valley in northern Switzerland where the transport of groundwater to surface soil might be possible. The hydrological situation has been examined to allow a system of compartments and fluxes for modelling this pathway with respect to the release of radionuclides from an underground repository to be produced. Assuming present day conditions the best estimate surface soil concentrations are calculated by dividing the soil into two layers (deep soil, surface soil) and assuming an annual upward flux of 10 mm from the groundwater through the two soil layers. A constant unit activity concentration is assumed for the radionuclides in the groundwater. It is concluded that the resultant best estimate values must still be considered to be biased on the conservative side, in view of the fact that the more typical situation is likely to be that no groundwater reaches the surface soil. Upper and lower estimates for the surface soil radionuclide concentrations are based on the parameter perturbation results which were carried out for three key parameters, i.e. precipitation surplus, upward flux and solid-liquid distribution coefficients (K d ). It is noted that attention must be given to the functional relationships which exist between various model parameters. Upper estimates for the surface soil concentration are determined assuming a higher annual upward flux (100 mm) as well as a more conservative K d value compared with the base case. This gives rise to surface soil concentrations more than two orders of magnitude higher than the best estimate values. The lower estimated are more easily assigned assuming that no activity reaches the surface soil via this pathway. (author) 18 figs., 4 tabs., refs

  15. 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

  16. The long term behaviour of the near-field barrier surrounding a deep underground repository

    International Nuclear Information System (INIS)

    1992-02-01

    This report describes research to identify the factors which govern or influence the long-term behaviour of the near-field of a nuclear waste repository. The near-field components include the engineered barriers and the natural rock mass although the behaviour of the rock mass is of greater significance over the long-term. The factors which govern the near-field behaviour consist of the processes which operate, and the properties or parameters of the rock mass which might be modified by them. The methods which are available for the prediction of the near-field behaviour have been identified, and the emphasis on computer based methods is noted. Summary details of generic computer techniques are provided for different process modelling requirements. An attempt is made to indicate how different processes will be important at various stages during the life of the repository and how the evaluation of performance assessment process modelling requires input from empirical models and the results of other process predictions. (Author)

  17. Swedish spent fuel management systems, facilities and operating experiences

    International Nuclear Information System (INIS)

    Vogt, J.

    1998-01-01

    About 50% of the electricity in Sweden is generated by means of nuclear power from 12 LWR reactors located at four sites and with a total capacity of 10,000 MW. The four utilities have jointly created SKB, the Swedish Nuclear Fuel and Waste Management Company, which has been given the mandate to manage the spent fuel and radioactive waste from its origin at the reactors to the final disposal. SKB has developed a system for the safe handling of all kinds of radioactive waste from the Swedish nuclear power plants. The keystones now in operation of this system are a transport system, a central interim storage facility for spent nuclear fuel (CLAB), a final repository for short-lived, low and intermediate level waste (SFR). The remaining, system components being planned are an encapsulation plant for spent nuclear fuel and a deep repository for encapsulated spent fuel and other long-lived radioactive wastes. (author)

  18. Process for selecting a site for Canada's deep geological repository for used nuclear fuel

    International Nuclear Information System (INIS)

    Facella, J.; Ben Belfadhel, M.; Patton, P.

    2012-01-01

    'Full Text:' The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management, the approach selected by the Government of Canada for long-term management of used nuclear fuel waste generated by Canadian nuclear reactors. The ultimate objective of Adaptive Phased Management is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository in a suitable crystalline or sedimentary rock formation at a depth of about 500m. The repository will consist of a series of access and service shafts and a series of tunnels leading to placement rooms where used fuel will be placed and sealed in competent rock using a multi-barrier system which includes long lived specially designed containers, sealing materials such as bentonite and the rock itself. The used fuel will be monitored throughout all phases of implementation and will also remain retrievable for an extended period of time. In May 2010, the NWMO published the site selection process that serves as the road map to decision-making on the location for the deep geological repository. NWMO initiated the process with a first stage that invites communities to learn more about the project and the site selection process. NWMO is actively building awareness of the project and, on request of communities, is delivering briefings, supporting community capacity building and undertaking screenings of site suitability. This panel presentation provides a brief description of: Adaptive Phased Management including the deep geological repository which is its ultimate goal, and the design of the site selection process, and importantly the approach to assessing the suitability of sites from both a social and technical perspective. The panel presentation will be conducted in three parts: site selection process and engagement, Aboriginal engagement and Technical evaluations, followed by a discussion. The presentation will outline how NWMO sought

  19. The use of interaction matrices for identification, structuring and ranking of FEPs in a repository system. Application on the far-field of a deep geological repository for spent fuel

    Energy Technology Data Exchange (ETDEWEB)

    Skagius, K; Wiborgh, M [Kemakta, Stockholm (Sweden); Stroem, A [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden)

    1995-11-01

    The basic device in the Rock Engineering Systems approach, the interaction matrix, has been used to identify, structure and rank Features, Events, and Processes (FEPs) describing barrier performance and radionuclide behaviour in the far-field of a deep geologic repository for spent fuel. The result is a first version of the Process System (PS), for the far-field of a deep repository, structured in an interaction matrix with supporting documentation. The documentation is compiled in databases, one containing matrix specific information and one containing general FEP descriptions. The study has shown that an interaction matrix is feasible to use both for the structuring of the PS and for visualisation of the PS. The developed documentation system increases the transparency of the system description and makes it possible to trace back the judgements made during the construction of the matrix. This will facilitate review work and future revisions as well as consistent treatment of different issues in the system. This study is a first step in the application of a systematic method to establish a structured description of the PS for a deep repository for spent fuel. The work could be seen as a part of the preparation for the forthcoming performance and safety analysis. The next step would be to develop the PS for the remaining parts of the repository system to the same level as has been done for the far-field system. Before the PS is evaluated for different selected system premises, a scientific review of the contents of the PS for the whole repository system would be beneficial. 5 refs.

  20. The use of interaction matrices for identification, structuring and ranking of FEPs in a repository system. Application on the far-field of a deep geological repository for spent fuel

    International Nuclear Information System (INIS)

    Skagius, K.; Wiborgh, M.; Stroem, A.

    1995-11-01

    The basic device in the Rock Engineering Systems approach, the interaction matrix, has been used to identify, structure and rank Features, Events, and Processes (FEPs) describing barrier performance and radionuclide behaviour in the far-field of a deep geologic repository for spent fuel. The result is a first version of the Process System (PS), for the far-field of a deep repository, structured in an interaction matrix with supporting documentation. The documentation is compiled in databases, one containing matrix specific information and one containing general FEP descriptions. The study has shown that an interaction matrix is feasible to use both for the structuring of the PS and for visualisation of the PS. The developed documentation system increases the transparency of the system description and makes it possible to trace back the judgements made during the construction of the matrix. This will facilitate review work and future revisions as well as consistent treatment of different issues in the system. This study is a first step in the application of a systematic method to establish a structured description of the PS for a deep repository for spent fuel. The work could be seen as a part of the preparation for the forthcoming performance and safety analysis. The next step would be to develop the PS for the remaining parts of the repository system to the same level as has been done for the far-field system. Before the PS is evaluated for different selected system premises, a scientific review of the contents of the PS for the whole repository system would be beneficial. 5 refs

  1. Gas generation in deep radioactive waste repositories: a review of processes, controls and models

    International Nuclear Information System (INIS)

    Jones, M.A.

    1990-10-01

    Gas generation within radioactive waste repositories may produce two general problems: 1) breaching of engineered and natural barriers due to high gas pressures; 2) enhanced radiological risk due to reduced groundwater travel times and/or greater aqueous or gaseous activities reaching the biosphere. As a result of these concerns, HMIP must be aware of the current status of relevant research, together with any associated deficiencies. This report addresses the current status of published research on near-field gas generation from worldwide sources and documents the important gas generating processes, the factors controlling them and models available to simulate them. In the absence of suitable models, outline technical specifications for corrosion and microbial degradation gas generation models are defined and the deficiencies in the current understanding of gas generation are highlighted; a conceptual research programme to correct these deficiencies is presented. (author)

  2. Melodie: a code for risk assessment of waste repositories in deep geological formations

    International Nuclear Information System (INIS)

    Lewi, J.; Mejon-Goula, M.J.; Cernes, A.

    1988-10-01

    In order to perform the safety evaluation of nuclear waste repositories, a global model, called MELODIE, is currently developed at the CEA/IPSN, in collaboration with order CEA teams and non-CEA like ENSMP (Ecole Nationale Superieure des Mines de Paris). The version now in operation allows to assess the radiological consequences due to a repository located in a granitic formation on a period of several hundred thousands of years. The calculations are based on models which represent the physical and chemical phenomena in connection with: the release of the radionuclides from the waste matrixes and through the engineered barriers; their transfer through the geosphere; their behaviour in the biosphere. Three separate models have been developed for each of these subjects; they are integrated in the code through a modular flexible dataprocessing structure which calls these computational modules with their optimal time step and extracts the data from the data files where they are stored. In addition, a sensitivity and uncertainty analysis algorithm has been implemented into the code. It allows to evaluate the influence of the parameter values on the result and to assess the global uncertainty on it. After a quite general description of MELODIE, the calculations performed with it in the PAGIS (CCE) exercise: global dose calculations and ranking of the most important parameters through the sensitivity analysis, are presented. The studies performed only with the geosphere module of MELODIE (METIS), especially the participation to the HYDROCOIN (OECD/NEA) exercise, are also noticed. In addition, the main future development axes of MELODIE are outlined

  3. Radioactive waste disposal programme and siting regions for geological deep repositories. Executive summary. November 2008; Entsorgungsprogramm und Standortgebiete fuer geologische Tiefenlager. Zusammenfassung. November 2008

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2008-11-15

    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

  4. Retrievability from waste repositories in deep geological formation and how it can be guaranteed

    International Nuclear Information System (INIS)

    Viala, M.

    2000-01-01

    The paper considers retrievability in the context of a facility type termed deep interim storage, convertible to permanent disposal. Such a facility isolates the waste in a reliable manner while keeping several options open. Options are obtained at cost and cannot be indefinitely left open. Various aspects for pursuing this concept are discussed. (author)

  5. Numerical investigation of high level nuclear waste disposal in deep anisotropic geologic repositories

    KAUST Repository

    Salama, Amgad; El Amin, Mohamed F.; Sun, Shuyu

    2015-01-01

    One of the techniques that have been proposed to dispose high level nuclear waste (HLW) has been to bury them in deep geologic formations, which offer relatively enough space to accommodate the large volume of HLW accumulated over the years since

  6. Disposal of radioactive waste in Swedish crystalline rocks

    International Nuclear Information System (INIS)

    Greis Dahlberg, Christina; Wikberg, Peter

    2015-01-01

    SKB, Swedish Nuclear Fuel and Waste Management Company is tasked with managing Swedish nuclear and radioactive waste. Crystalline rock is the obvious alternative for deep geological disposal in Sweden. SKB is, since 1988, operating a near surface repository for short-lived low and intermediate-level waste, SFR. The waste in SFR comprises operational and decommissioning waste from nuclear plants, industrial waste, research-related waste and medical waste. Spent nuclear fuel is currently stored in an interim facility while waiting for a license to construct a deep geological repository. The Swedish long-lived low and intermediate-level waste consists mainly of BWR control rods, reactor internals and legacy waste from early research in the Swedish nuclear programs. The current plan is to dispose of this waste in a separate deep geological repository, SFL, sometimes after 2045. Understanding of the rock properties is the basis for the design of the repository concepts. Swedish crystalline rock is mechanical stable and suitable for underground constructions. The Spent Fuel Repository is planned at approximately 500 meters depth in the rock at the Forsmark site. The host rock will keep the spent fuel isolated from human and near-surface environment. The rock will also provide the stable chemical and hydraulic conditions that make it possible to select suitable technical barriers to support the containment provided by the rock. A very long lasting canister is necessary to avoid release and transport of radionuclides through water conducting fractures in the rock. A canister designed for the Swedish rock, consists of a tight, 5 cm thick corrosion barrier of copper and a load-bearing insert of cast iron. To restrict the water flow around the canister and by that prevent fast corrosion, a bentonite buffer will surround the canister. Secondary, the bentonite buffer will retard a potential release by its strong sorption of radionuclides. The SFR repository is situated in

  7. Disposal of radioactive waste in Swedish crystalline rocks

    Energy Technology Data Exchange (ETDEWEB)

    Greis Dahlberg, Christina; Wikberg, Peter [Svensk Kaernbraenslehantering AB, Stockholm (Sweden)

    2015-07-01

    SKB, Swedish Nuclear Fuel and Waste Management Company is tasked with managing Swedish nuclear and radioactive waste. Crystalline rock is the obvious alternative for deep geological disposal in Sweden. SKB is, since 1988, operating a near surface repository for short-lived low and intermediate-level waste, SFR. The waste in SFR comprises operational and decommissioning waste from nuclear plants, industrial waste, research-related waste and medical waste. Spent nuclear fuel is currently stored in an interim facility while waiting for a license to construct a deep geological repository. The Swedish long-lived low and intermediate-level waste consists mainly of BWR control rods, reactor internals and legacy waste from early research in the Swedish nuclear programs. The current plan is to dispose of this waste in a separate deep geological repository, SFL, sometimes after 2045. Understanding of the rock properties is the basis for the design of the repository concepts. Swedish crystalline rock is mechanical stable and suitable for underground constructions. The Spent Fuel Repository is planned at approximately 500 meters depth in the rock at the Forsmark site. The host rock will keep the spent fuel isolated from human and near-surface environment. The rock will also provide the stable chemical and hydraulic conditions that make it possible to select suitable technical barriers to support the containment provided by the rock. A very long lasting canister is necessary to avoid release and transport of radionuclides through water conducting fractures in the rock. A canister designed for the Swedish rock, consists of a tight, 5 cm thick corrosion barrier of copper and a load-bearing insert of cast iron. To restrict the water flow around the canister and by that prevent fast corrosion, a bentonite buffer will surround the canister. Secondary, the bentonite buffer will retard a potential release by its strong sorption of radionuclides. The SFR repository is situated in

  8. Does unemployment cause long-term mortality? Selection and causation after the 1992–96 deep Swedish recession

    Science.gov (United States)

    Garcy, Anthony M.

    2016-01-01

    Abstract Background: Mass unemployment in Europe is endemic, especially among the young. Does it cause mortality? Methods: We analyzed long-term effects of unemployment occurring during the deep Swedish recession 1992–96. Mortality from all and selected causes was examined in the 6-year period after the recession among those employed in 1990 (3.4 million). Direct health selection was analyzed as risk of unemployment by prior medical history based on all hospitalizations 1981–91. Unemployment effects on mortality were estimated with and without adjustment for prior social characteristics and for prior medical history. Results: A prior circulatory disease history did not predict unemployment; a history of alcohol-related disease or suicide attempts did, in men and women. Unemployment predicted excess male, but not female, mortality from circulatory disease, both ischemic heart disease and stroke, and from all causes combined, after full adjustment. Adjustment for prior social characteristics reduced estimates considerably; additional adjustment for prior medical history did not. Mortality from external and alcohol-related causes was raised in men and women experiencing unemployment, after adjustment for social characteristics and medical history. For the youngest birth cohorts fully adjusted alcohol mortality HRs were substantial (male HR = 4.44; female HR = 5.73). The effect of unemployment on mortality was not uniform across the population; men, those with a low education, low income, unmarried or in urban employment were more vulnerable. Conclusions: Direct selection by medical history explains a modest fraction of any increased mortality risk following unemployment. Mass unemployment imposes long-term mortality risk on a sizeable segment of the population. PMID:27085193

  9. Development of low alkaline cementitious grouting materials for a deep geological repository

    International Nuclear Information System (INIS)

    Suzuki, Kenichiro; Miura, Norihiko; Iriya, Keishiro; Kobayashi, Yasushi

    2012-01-01

    In order to reduce uncertainties of long-term safety assessment for a High Level radioactive Waste (HLW) repository system, low alkaline cementitious grouting materials have been studied. The pH of the leachate from the grouting material is targeted to be below 11.0, since the degradation of the bentonite buffer and host rock is limited. The current work focused on the effects of pozzolanic reactions to reduce pH and the development of low alkaline cementitious injection materials in which super-micro ordinary Portland cement (SOPC) was partially replaced by silica fume (SF), micro silica (MS) and fly ash (FA). As it is important to realize how the grouting material will respond to a high injection pressure into the fracture, and in order to understand the penetrability of different low alkaline cement mixes and to observe their flow behavior through the fracture, injection tests were conducted by using a simulated model fracture of 2 m diameter made from parallel plates of acrylic acid resin and stainless steel. Experimental results of the basic properties for selecting suitable materials and that of injecting into a simulated fracture to assess the grouting performance are described

  10. Conceptual model for concrete long time degradation in a deep nuclear waste repository

    International Nuclear Information System (INIS)

    Lagerblad, B.; Traegaardh, J.

    1996-04-01

    Cement-based materials are fundamentally unstable in a long time perspective. With time the concrete will change properties both as a consequence of recrystallization and chemical interaction with the environment. One of the main difficulties with a conceptual model for concrete degradation is the change in the geochemical environment with time. During the first period the concrete will alter as a result of contact with atmospheric gases, especially CO 2 which will carbonate the surface. Later the degradation will mainly be governed by the composition of the groundwater with which it will try to equilibrate. Considering the chemical conditions at repository depths (500 m), it is possible that the groundwater will change composition from normal to saline. This may in fact be an advantage because the solubility of cement paste components decreases. However, the concrete will influence the groundwater composition and create an aureole with increased pH around it. Most of the components in both the fresh and saline water will not be harmful to concrete. One of the problems may be the chlorine anions, as this anion may substitute for sulfate in some of the cement phases. This will not degrade the concrete but the sulfates in the cement may be released to the groundwater. The end product of the concrete, after leaching and after the pH buffer capacity has been lost, will be a mix of metastable calcium silicate hydrates, zeolite and clay minerals. 72 refs

  11. Evaluation of engineering aspects of backfill placement for high level nuclear waste (HLW) deep geologic repositories

    International Nuclear Information System (INIS)

    Roberds, W.; Kleppe, J.; Gonano, L.

    1984-04-01

    This report includes the identification and subjective evaluation of alternative schemes for backfilling around waste packages and within emplacement rooms. The aspects of backfilling specifically considered in this study include construction and testing; costs have not been considered. However, because construction and testing are simply implementation and verification of design, a design basis for backfill is required. A generic basis has been developed for this study by first identifying qualitative performance objectives for backfill and then weighting each with respect to its potential influence on achieving the repository system performance objectives. Alternative backfill materials and additives have been identified and evaluated with respect to the perceived extent to which each combination can be expected to achieve the backfill design basis. Several distinctly different combinations of materials and additives which are perceived to have the highest potential for achieving the backfill design basis have been selected for further study. These combinations include zeolite/clinoptilolite, bentonite, muck, and muck mixed with bentonite. Feasible alternative construction and testing procedures for each selected combination have been discussed. Recommendations have been made regarding appropriate backfill schemes for hard rock (i.e., basalt at Hanford, Washington, tuff at Nevada Test Site, and generic granite) and salt (i.e., domal salt on the Gulf Coast and generic bedded salt). 27 references, 8 figures, 31 tables

  12. Considerations on pressure build-up in deep geological repositories for radioactive waste; Betrachtungen zum Druckaufbau in einem geologischen Tiefenlager fuer radioaktive Abfaelle

    Energy Technology Data Exchange (ETDEWEB)

    Beer, Hans-Frieder [Paul Scherrer Institut, Villigen-PSI (Switzerland)

    2015-07-01

    Gas formation caused by corrosion of metals is a pivotal point with respect to the safety analysis of deep geological repositories. Solid corrosion products are formed unavoidably during the gas formation. The volumes of these solid corrosion products are multiples of the original waste volume. These solid corrosion products are chemically extremely stable and result in a pressure increase inside the repository. This pressure is considerably higher than that of the overlaying rock. The question that arises is, why this aspect is not considered in the consulted documents.

  13. Deep repository and encapsulation plant for spent nuclear fuel. Consultation and environmental impact assessment according to the Environmental Code and the Nuclear Activities Act

    International Nuclear Information System (INIS)

    2002-11-01

    As a part of its programme for siting of a deep repository for spent nuclear fuel, SKB has recently commenced site investigations at Forsmark in Oesthammar Municipality and at Simpevarp in Oskarshamn Municipality. At the same time, SKB has initiated the consultation process prior to application for permits/licences under the Environmental Code and the Nuclear Activities Act. Early consultation has been carried out for both sites, and a consultation report has been submitted to the county administrative boards in Kalmar County and Uppsala County for decisions regarding significant environmental impact. After decisions by the county administrative boards, SKB will commence the work with environmental impact assessment and extended consultation. SKB's main alternative for the encapsulation plant is siting adjacent to CLAB. In the spring of 2003, SKB will convene early consultation on the encapsulation plant. This will be followed by extended consultation up to 2005. This process will be coordinated with the extended consultation for a deep repository in Oskarshamn. An alternative is to locate the encapsulation plant at a deep repository at Forsmark. This alternative is being dealt with completely within the extended consultation for the deep repository at Forsmark. Three different permits/licences are required for both the encapsulation plant and the deep repository: a permit under the Environmental Code, a licence under the Nuclear Activities Act, and a building permit under the Planning and Building Act. Licensing under the Environmental Code and the Nuclear Activities Act takes place in parallel. The applications under both laws must include an environmental impact statement (EIS) prepared according to the rules in Chapter 6 of the Environmental Code. The same EIS is thus used in both applications. Separate EISs are prepared for the encapsulation plant and the deep repository. According to the Environmental Code, the consultation shall relate to the location, scope

  14. Obtaining reasonable assurance on geochemical aspects of performance assessment of deep geologic repositories

    International Nuclear Information System (INIS)

    Van Luik, A.E.; Serne, R.J.

    1986-01-01

    Providing reasonable assurance that a deep geologic disposal system will perform as required by regulation involves, in part, the building of confidence by providing a sound scientific basis for the site characterization, engineered system design, and system performance modeling efforts. Geochemistry plays a role in each of these activities. Site characterization must result in a description of the in situ geochemical environment that will support the design of the engineered system and the modeling of the transport of specific radionuclides to the accessible environment. Judging the adequacy of this site characterization effort is a major aspect of providing reasonable assurance. Within site characterization, there are a number of geochemical issues that need to be addressed such as the usefulness of natural analog studies, and assessing the very long-term stability of the site geochemistry, given expected temperature and radiation conditions

  15. Biosphere modelling for a deep radioactive waste repository: treatment of the groundwater-soil pathway

    International Nuclear Information System (INIS)

    Baeyens, B.; Grogan, H.A.; Dorp, F. van

    1991-07-01

    The effect of radionuclide transfer from near-surface groundwater to the rooting zone soil, via a deep soil layer, is modelled in this report. The possible extent of upward solute movement is evaluated for a region in northern Switzerland. The concentration of 237 Np and 129 I in the deep and top soil, and hence growing crops, are evaluated assuming a constant unit activity concentration in the groundwater. A number of parameter variations are considered, namely variable soil sorption coefficients, reduced infiltration of rain water and decreased groundwater flow. A release to an alternative smaller recipient region in northern Switzerland is also evaluated. For the parameter ranges considered uncertainty in the solid-liquid distribution coefficient has the largest effect on overall uncertainty. These calculations have been presented within the international Biosphere Model Validation Study (BIOMOVS). A description of the test scenario, and the model calculations submitted, have been included in this report for completeness. To place the groundwater-soil-crop-man pathway in context, its contribution to the total dose to man is evaluated for the 237 Np- 233 U- 229 Th decay chain. The results obtained using the two-layer soil model, described in this report, are compared with the single-layer soil model used during Project Gewaehr 1985. The more realistic two-layer soil model indicated an increase in importance of the drinking water pathway. It should be noted, however, that not all the critical pathways have been treated in this study with the same degree of conservatism. (author) 16 figs., 15 tabs., 31 refs

  16. The potential for methane hydrate formation in deep repositories of spent nuclear fuel in granitic rocks

    International Nuclear Information System (INIS)

    Tohidi, Bahman; Chapoy, Antonin; Smellie, John; Puigdomenech, Ignasi

    2010-12-01

    performance of spent nuclear fuel repositories, namely ∼1 million years

  17. The potential for methane hydrate formation in deep repositories of spent nuclear fuel in granitic rocks

    Energy Technology Data Exchange (ETDEWEB)

    Tohidi, Bahman; Chapoy, Antonin (Hydrafact Ltd, Inst. of Petroleum Engineering, Heriot-Watt Univ., Edinburgh (United Kingdom)); Smellie, John (Conterra AB, Uppsala (Sweden)); Puigdomenech, Ignasi (Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden))

    2010-12-15

    satisfactory performance of spent nuclear fuel repositories, namely approx1 million years

  18. Hydrogeologic modelling in support of a proposed Deep Geologic Repository in Canada for low and intermediate level radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Sykes, J.F.; Normani, S.D.; Yin, Y. [Waterloo Univ., ON (Canada). Dept. of Civil and Environmental Engineering; Sykes, E.A.; Jensen, M.R. [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2009-07-01

    Ontario Power Generation (OPG) has proposed the construction of a Deep Geologic Repository (DGR) for low and intermediate level radioactive waste at the Bruce site on the shore of Lake Huron near Tiverton, Ontario. The DGR is to be excavated at a depth of about 680 m within argillaceous limestones of Ordovician age. A saturated regional-scale and site-scale numerical modelling study has been completed in order to evaluate the safety of storing radioactive waste at the site and to better understand the geochemistry and hydrogeology of the formations surrounding the proposed DGR. This paper reported on the regional-scale base-case modelling and analysis of the measured pressure profile in deep boreholes at the DGR site. The numerical modelling study provided a framework to investigate the groundwater flow system as it relates to, and potentially affects, the safety and long-term performance of the DGR. A saturated groundwater flow model was also developed using FRAC3DVS-OPG. The objective of regional-scale groundwater modelling of the Paleozoic sedimentary sequence underlying southwestern Ontario was to provide a basis for the assembly and integration of site-specific geoscientific data and to explain the influence of parameter and scenario uncertainty on predicted long-term geosphere barrier performance. The base-case analysis showed that solute transport in the Ordovician and lower Silurian is diffusion dominant. For the base-case parameters, the estimated mean life expectancy for the proposed DGR is more than 8 million years. The possible presence of a gas phase in the rock between the Cambrian and the Niagaran was not considered in the analyses of this paper. 9 refs., 2 tabs., 10 figs.

  19. A Methodology to analyze the biosphere in the assessment of deep geological repositories for high level radioactive waste

    International Nuclear Information System (INIS)

    Pinedo, P.; Smith, G.

    1996-11-01

    This report summarizes the work done and the achievements reached within the R and D Project that IMA/CIEMAT has had with ENRESA during 1993-1995. The overall R and D Project has a wide radiological protection context, but the work reported here relates only to the development of a Methodology for considering the Biosphere sub-system in the assessments of deep geological repositories for high radioactive wastes (HLW). The main areas concerned within the Methodology have to do with the Biosphere structure and morphology in the long-term relevant to deep disposal of HLW: in the contexts of the assessment of these systems, and appropriate modelling of the behaviour of radionuclides released to the biosphere system and with the associated human exposure. This document first provides a review of the past and present international and national concerns about the biosphere modelling and its importance in relation to the definition of safety criteria. A joint ENRESA/ANDRA/IPSN/CIEMAT study about the definition and practical descriptions of the biosphere systems under different climatic states is then summarized. The Methodology developed by IMA/CIEMAT is outlined with an illustration of the way it works. Different steps and procedures are included for a better practical understanding of the software tools developed within the project to support the application of the Methodology. This methodology is widely based on an international working group on ''Reference Biospheres'', part of the BIOMOVS II Project. Specific software developments have been carried out in collaboration with Qunti Sci Itd and with the Polytechnical University of Madrid. (Author)

  20. 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

  1. Local opposition and acceptance of a deep geological repository of radioactive waste in the Czech Republic: A frame analysis

    International Nuclear Information System (INIS)

    Ocelík, Petr; Osička, Jan; Zapletalová, Veronika; Černoch, Filip; Dančák, Břetislav

    2017-01-01

    The article explores framing of the siting process of a deep geological repository of nuclear waste in the Czech Republic by the municipalities’ representatives in the pre-selected localities. Three distinguished frames have been reconstructed. The risk frame, which connects the project with a number of predominantly environmental threats, is counter-balanced by the responsibility frame that uses the ‘Not-In-My-Back-Yard’ label to delegitimize the local opposition. The third frame then portrays the siting process as a display of general distrust towards political elites and state institutions. It is argued that the distinguished frames stem from a deeper ideological conflict about the nature of democratic governance and the value attributed to environment, further stressing the importance of a siting process’ institutional arrangement that goes beyond technocratic solutions. - Highlights: • We have examined framing of nuclear waste management at the local level. • Three frames (Responsibility, Risk, and Dysfunctional state) were reconstructed. • The frames stem from ideological divisions on questions of governance and justice. • Participatory mechanisms should be used in policy-compromise building.

  2. OPG's deep geologic repository for low and intermediate level waste - public participation and aboriginal engagement

    International Nuclear Information System (INIS)

    Wilson, M.

    2011-01-01

    Ontario Power Generation (OPG)'s Public Participation and Aboriginal Engagement Program for the proposed Deep Geologic Repository (DGR) for low and intermediate level waste (L and ILW) began with the signing of a Memorandum of Understanding (MOU) in 2002 between OPG and the Municipality of Kincardine. The MOU set out the terms under which the two parties would jointly study the feasibility of different options for the long-term management of L and ILW at the Bruce nuclear site. A consultant, independent from both the Municipality of Kincardine and OPG, was retained to manage the assessment of options as well as a communication plan to ensure the public and Aboriginal peoples were kept apprised of all activities associated with the MOU. This early commitment to transparency and openness, with its ensuing opportunities for the public and Aboriginal peoples to become informed, ask questions, and engage in meaningful two-way dialogue about the early assessment of options, established the foundation and later became the hallmark of the DGR Project's Public Participation and Aboriginal Engagement program. This paper provides an overview of the development, nature and results of that program as it has evolved through the early investigative stages of options and through the environmental assessment and licencing process for the proposed DGR Project. (author)

  3. Use of natural analogues to support radionuclide transport models for deep geological repositories for long lived radioactive wastes

    International Nuclear Information System (INIS)

    1999-10-01

    Plans to dispose high level and long lived radioactive wastes in deep geological repositories have raised a number of unique problems, mainly due to the very long time-scales which have to be considered. An important way to help to evaluate performance and provide confidence in the assessment of safety in the long term is to carry out natural analogue studies. Natural analogues can be regarded as long term natural experiments the results or outcome of which can be observed, but which, by definition, are uncontrolled by humans. Studies of natural analogues have been carried out for more than two decades, although the application of information from them is only relatively recently becoming scientifically well ordered. This report is part of a the IAEA's programme on radioactive waste management dealing with disposal system technology for high level and long lived radioactive waste. It presents the current status of natural analogue information in evaluating models for radionuclide transport by groundwater. In particular, emphasis is given to the most useful aspects of quantitative applications for model development and testing (geochemistry and coupled transport models). The report provides an overview of various natural analogues as reference for those planning to develop a research programme in this field. Recommendations are given on the use of natural analogues to engender confidence in the safety of disposal systems. This report is a follow up of Technical Reports Series No. 304 on Natural Analogues in Performance Assessments for the Disposal of Long Lived Radioactive Waste (1989)

  4. The OPG/Kincardine hosting agreement for a deep geologic repository for OPG's low- and intermediate-level waste

    International Nuclear Information System (INIS)

    Castellan, A.G.; Barker, D.E.

    2006-01-01

    A Hosting Agreement has been reached between Ontario Power Generation and the Municipality of Kincardine for the purpose of siting a long-term management facility for low- and intermediate-level radioactive waste at the Western Waste Management Facility. Following an independent review of the feasibility of three options for a long-term facility at the site, including a review of the safety, geotechnical feasibility, social and economic effects and potential environmental effects, Kincardine passed a resolution indicating their preference for a Deep Geologic Repository. A Host Community Agreement has been negotiated based on this preference, and on information that had been gathered from municipal authorities at other locations that have hosted similar facilities. The Hosting Agreement includes financial compensation, totalling $35.7 million (Canadian 2004) to the Municipality of Kincardine and to four surrounding municipalities. The financial aspects include lump sum payments based on achieving specific project milestones as well as annual payments to each of the municipalities. The payments are indexed to inflation, and are also contingent on the municipalities acting reasonably and in good faith during the licencing process of the proposed facility. In addition to the fees, the Agreement includes provision for a Property Value Protection Plan that would provide residents with compensation in the event that there is depreciation in property value shown to directly result from a release from the proposed facility. New permanent OPG jobs supporting the project would be located at the site. OPG and Kincardine will support a centre of nuclear excellence. (author)

  5. Canada's deep geological repository for used nuclear fuel - update on the site evaluation process and interweaving of aboriginal traditional knowledge

    Energy Technology Data Exchange (ETDEWEB)

    Watts, B.; Belfadhel, M.B.; Facella, J., E-mail: bwatt@nwmo.ca, E-mail: mbenbelfadhel@nwmo.ca, E-mail: jfacella@nwmo.ca [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2015-07-01

    The Nuclear Waste Management Organization (NWMO) is responsible for implementing Adaptive Phased Management (APM), the approach selected by the Government of Canada for the long-term management of used nuclear fuel generated by Canadian nuclear reactors. The ultimate objective of APM is the centralized containment and isolation of Canada's used nuclear fuel in a Deep Geological Repository (DGR) in a suitable crystalline or sedimentary rock formation. In May 2010, the NWMO initiated a nine-step site selection process to seek an informed and willing community to host Canada's deep geological repository. As of April 2015, twenty-two communities expressed interest in learning more about the project. This paper provides an update on the site evaluation process and describes the approach, methods and criteria used in the assessments, focusing on geological and community well-being studies. Engagement and field activities to interweave Aboriginal Traditional Knowledge with western science are also discussed. (author)

  6. Numerical investigation of high level nuclear waste disposal in deep anisotropic geologic repositories

    KAUST Repository

    Salama, Amgad

    2015-11-01

    One of the techniques that have been proposed to dispose high level nuclear waste (HLW) has been to bury them in deep geologic formations, which offer relatively enough space to accommodate the large volume of HLW accumulated over the years since the dawn of nuclear era. Albeit the relatively large number of research works that have been conducted to investigate temperature distribution surrounding waste canisters, they all abide to consider the host formations as homogeneous and isotropic. While this could be the case in some subsurface settings, in most cases, this is not true. In other words, subsurface formations are, in most cases, inherently anisotropic and heterogeneous. In this research, we show that even a slight difference in anisotropy of thermal conductivity of host rock with direction could have interesting effects on temperature fields. We investigate the effect of anisotropy angle (the angle the principal direction of anisotropy is making with the coordinate system) on the temperature field as well as on the maximum temperature attained in different barrier systems. This includes 0°, 30°, 45°, 60°, and 90°in addition to the isotropic case as a reference. We also consider the effect of anisotropy ratio (the ratio between the principal direction anisotropies) on the temperature fields and maximum temperature history. This includes ratios ranging between 1.5 and 4. Interesting patterns of temperature fields and profiles are obtained. It is found that the temperature contours are aligned more towards the principal direction of anisotropy. Furthermore the peak temperature in the buffer zone is found to be larger the smaller the anisotropy angle and vice versa. © 2015 Elsevier Ltd. All rights reserved.

  7. Environmental and health impacts of February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository.

    Science.gov (United States)

    Thakur, P; Lemons, B G; Ballard, S; Hardy, R

    2015-08-01

    The environmental impact of the February 14, 2014 radiation release from the nation's only deep geologic nuclear waste repository, the Waste Isolation Pilot Plant (WIPP) was assessed using monitoring data from an independent monitoring program conducted by the Carlsbad Environmental Monitoring & Research Center (CEMRC). After almost 15 years of safe and efficient operations, the WIPP had one of its waste drums rupture underground resulting in the release of moderate levels of radioactivity into the underground air. A small amount of radioactivity also escaped to the surface through the ventilation system and was detected above ground. It was the first unambiguous release from the WIPP repository. The dominant radionuclides released were americium and plutonium, in a ratio that matches the content of the breached drum. The accelerated air monitoring campaign, which began following the accident, indicates that releases were low and localized, and no radiation-related health effects among local workers or the public would be expected. The highest activity detected was 115.2 μBq/m(3) for (241)Am and 10.2 μBq/m(3) for (239+240)Pu at a sampling station located 91 m away from the underground air exhaust point and 81.4 μBq/m(3) of (241)Am and 5.8 μBq/m(3) of (239+240)Pu at a monitoring station located approximately one kilometer northwest of the WIPP facility. CEMRC's recent monitoring data show that the concentration levels of these radionuclides have returned to normal background levels and in many instances, are not even detectable, demonstrating no long-term environmental impacts of the recent radiation release event at the WIPP. This article presents an evaluation of almost one year of environmental monitoring data that informed the public that the levels of radiation that got out to the environment were very low and did not, and will not harm anyone or have any long-term environmental consequence. In terms of radiological risk at or in the vicinity of the

  8. The Evaluation of Material Properties of Low-pH Cement Grout for the Application of Cementitious Materials to Deep Radioactive Waste Repository Tunnels

    International Nuclear Information System (INIS)

    Kim, Jin Seop; Kwon, S. K.; Cho, W. J.; Kim, G. W.

    2009-12-01

    Considering the current construction technology and research status of deep repository tunnels for radioactive waste disposal, it is inevitable to use cementitious materials in spite of serious concern about their long-term environmental stability. Thus, it is an emerging task to develop low pH cementitious materials. This study reviews the state of the technology on low pH cements developed in Sweden, Switzerland, France, and Japan as well as in Finland which is constructing a real deep repository site for high-level radioactive waste disposal. Considering the physical and chemical stability of bentonite which acts as a buffer material, a low pH cement limits to pH ≤11 and pozzolan-type admixtures are used to lower the pH of cement. To attain this pH requirement, silica fume, which is one of the most promising admixtures, should occupy at least 40 wt% of total dry materials in cement and the Ca/Si ratio should be maintained below 0.8 in cement. Additionally, selective super-plasticizer needs to be used because a high amount of water is demanded from the use of a large amount of silica fume. In this report, the state of the technology on application of cementitious materials to deep repository tunnels for radioactive waste disposal was analysed. And the material properties of low-pH and high-pH cement grouts were evaluated base on the grout recipes of ONKALO in Finlan

  9. Mining and engineering aspects and variants for the underground construction of a deep geological repository for radioactive waste and spent nuclear fuel

    International Nuclear Information System (INIS)

    Milchev, M.; Michailov, B.; Nanovska, E.; Harizanov, A.

    2003-01-01

    The aim of the present report is to investigate and to describe systematically the foreign experience, scientific and technical achievements and stages of development concerning the mining and engineering aspects and variants for underground construction of a deep geological repository for radioactive waste (RAW) and spent nuclear fuel (SNF). The ideal solution in managing the problems with harmful wastes seems to be either to remove them permanently from Earth (which is related with high risks and high costs) or to transform long-lived radionuclides to short-lived radionuclides using nuclear transmutation processes in a reactor or a particle accelerator. The latter is also a complex and immensely costly process and it can only reduce the quantities of some long-lived radionuclides, which can be then disposed in a geological repository. At present, the deep geological disposal remains the only solution for solving the problem with the hazard of storing radioactive wastes. The report submits a brief description and systematization of the performed investigations, accompanied by analysis of the scientific and technical level on world scale. The analysis is related with the particular geological conditions and the existing scientific studies available so far in Bulgaria. The main conclusions are that the complex scientific-technical and engineering problems related with the construction of a deep geological repository for RAW and SNF require long-term scientific investigations and preliminary complex works and it is high time to launch them in Bulgaria. (authors)

  10. Probabilistic calculations and sensitivity analysis of parameters for a reference biosphere model assessing the potential exposure of a population to radionuclides from a deep geological repository

    Energy Technology Data Exchange (ETDEWEB)

    Staudt, Christian; Kaiser, Jan Christian [Helmholtz Zentrum Muenchen, Institute of Radiation Protection, Munich (Germany); Proehl, Gerhard [International Atomic Energy Agency, Division of Radiation, Transport and Waste Safety, Wagramerstrasse 5, 1400 Vienna (Austria)

    2014-07-01

    Radioecological models are used to assess the exposure of hypothetical populations to radionuclides. Potential radionuclide sources are deep geological repositories for high level radioactive waste. Assessment time frames are long since releases from those repositories are only expected in the far future, and radionuclide migration to the geosphere biosphere interface will take additional time. Due to the long time frames, climate conditions at the repository site will change, leading to changing exposure pathways and model parameters. To identify climate dependent changes in exposure in the far field of a deep geological repository a range of reference biosphere models representing climate analogues for potential future climate states at a German site were developed. In this approach, model scenarios are developed for different contemporary climate states. It is assumed that the exposure pathways and parameters of the contemporary biosphere in the far field of the repository will change to be similar to those at the analogue sites. Since current climate models cannot predict climate developments over the assessment time frame of 1 million years, analogues for a range of realistically possible future climate conditions were selected. These climate states range from steppe to permafrost climate. As model endpoint Biosphere Dose conversion factors (BDCF) are calculated. The radionuclide specific BDCF describe the exposure of a population to radionuclides entering the biosphere in near surface ground water. The BDCF are subject to uncertainties in the exposure pathways and model parameters. In the presented work, probabilistic and sensitivity analysis was used to assess the influence of model parameter uncertainties on the BDCF and the relevance of individual parameters for the model result. This was done for the long half-live radionuclides Cs-135, I-129 and U-238. In addition to this, BDCF distributions for nine climate reference regions and several scenarios were

  11. Evaluation of SKB's report 'Deep repository for spent nuclear fuel: SR 97 - Post-closure safety', Focusing on the assessment of transport processes in the geosphere

    Energy Technology Data Exchange (ETDEWEB)

    Woerman, A.; Shulan Xu [Uppsala Univ. (Sweden). Dept. of Geoscience

    2000-12-01

    This report describes a critical review of the safety assessment performed on the final repository for nuclear waste in Sweden that is proposed by SKB in 'Deep Repository for Spent Nuclear Fuel: SR 97 - Post-closure Safety'. The review was requested by the Swedish Nuclear Power Inspectorate (SKI). The waste repository consists of several barriers that work together with the purpose of delaying radionuclide migration and reducing the activity that eventually affects the biosphere. A main criticism is the lack of a formal risk analysis and uncertainties in several analyses that make it difficult to comprehend the overall risk of the repository. A formal risk analysis should comprise a probabilistic treatment of all components included in the system. This is not the case in the SKB's report since the probabilistic analyses are limited only to certain aspects. The use of conservative model parameters are not a substitute for risk analysis nor can they compensate for possible model biases. Bias can be expected in most of the existing models of radionuclide migration in fractured bedrock. SKB should present a clear comparison on the importance of the different barrier components (uranium-dioxide matrix, copper canister, buffer and bedrock) on the retardation of radionuclides. It is unclear as to what extent the capacity of the bedrock to retain migrating radionuclides is critical to the capacity of the repository. A large part of the SR 97 report is focused on retardation processes in bedrock and a reader can interpret this as the technical weight given on retardation in the bedrock. However, with the present state of knowledge, it is our opinion that we cannot with an acceptable degree of accuracy predict the radionuclide transport in bedrock or quantify risk levels associated with radioactivity in the biosphere. There are large uncertainties concerning the way by which sorption processes should be formulated and the impact of colloids on the transport

  12. Injection grout for deep repositories - Low-pH cementitious grout for larger fractures. Field testing in Finland, Pilot tests

    International Nuclear Information System (INIS)

    Sievaeen, U.; Syrjaenen, P.; Ranta-aho, S.

    2005-10-01

    Posiva, SKB and NUMO have cooperated for developing a low pH injection grout for sealing of the deep repositories for spent nuclear fuel. A project 'Injection grout for deep repositories' was divided into four subprojects. The development of low pH cementitious grout for > 100 μm fractures was carried out in Finland. The development of non-cementitious low pH grout for < 100 μm fractures was carried out in Sweden. This report concerns the cementitious grout. Requirements for pH and penetration ability were set for the grouts to be developed. Besides these, the grouts were desired to fulfil certain targets set for viscosity, bleeding, shear strength, yield value, compressive strength and open time. Also durability, availability of the components and known history in practical engineering were given as requirements. The object of the work presented here was to test if the grout properties developed in laboratory can be met in field conditions. Only the most promising binder material combinations, which have fulfilled the main requirements in laboratory, were tested in field. Evaluations of environmental aspects are included in this report. In the pilot test 1, carried out in a multi-purpose tunnel in Helsinki, Portland cement-cilicasystem and blast furnace slag-based system were chosen to be tested. In field conditions, mixed with ordinary mixer, all grout properties achieved in laboratory, were not verified. Penetration ability was typically good, but fluidity and strength development were not satisfying. The main conclusion was that water to dry material ratio should be diminished. In order to get better rheological properties at the same time, superplastizicer was needed in further development of the mixes. Also accurate dosing and mixing seemed to be very important. Blast furnace slag - system was after this pilot test ruled out due to high leaching of sulphide from the product, not due to the bad technical properties. The development work continued with

  13. Maximum flood hazard assessment for OPG's deep geologic repository for low and intermediate level waste

    International Nuclear Information System (INIS)

    Nimmrichter, P.; McClintock, J.; Peng, J.; Leung, H.

    2011-01-01

    Ontario Power Generation (OPG) has entered a process to seek Environmental Assessment and licensing approvals to construct a Deep Geologic Repository (DGR) for Low and Intermediate Level Radioactive Waste (L&ILW) near the existing Western Waste Management Facility (WWMF) at the Bruce nuclear site in the Municipality of Kincardine, Ontario. In support of the design of the proposed DGR project, maximum flood stages were estimated for potential flood hazard risks associated with coastal, riverine and direct precipitation flooding. The estimation of lake/coastal flooding for the Bruce nuclear site considered potential extreme water levels in Lake Huron, storm surge and seiche, wind waves, and tsunamis. The riverine flood hazard assessment considered the Probable Maximum Flood (PMF) within the local watersheds, and within local drainage areas that will be directly impacted by the site development. A series of hydraulic models were developed, based on DGR project site grading and ditching, to assess the impact of a Probable Maximum Precipitation (PMP) occurring directly at the DGR site. Overall, this flood assessment concluded there is no potential for lake or riverine based flooding and the DGR area is not affected by tsunamis. However, it was also concluded from the results of this analysis that the PMF in proximity to the critical DGR operational areas and infrastructure would be higher than the proposed elevation of the entrance to the underground works. This paper provides an overview of the assessment of potential flood hazard risks associated with coastal, riverine and direct precipitation flooding that was completed for the DGR development. (author)

  14. Doses in various parts of the biosphere due to long-lived radionuclides originating from deep geological repositories

    International Nuclear Information System (INIS)

    Bergstroem, U.; Karlsson, Sara; Nordlinder, S.

    1999-01-01

    Turnover of radionuclides and resulting doses to man were modelled for various parts of the biosphere. This was made for different scenarios of leakage of radionuclides from a deep geological repository for spent nuclear fuel and other waste. In previous studies, the emphasis was on doses from contaminated ground water represented by a well or various surface waters. This was because radionuclides were assumed to be released directly to surface water, the use of which subsequently formed the major pathway for radionuclides to agricultural areas. In the present study, radionuclides were considered to reach lakes, running waters, coastal areas, agricultural areas and peat areas. The inflow of radionuclides to agricultural areas was supposed to be from below. Doses due to direct use of contaminated ground water from a well were also considered. Altogether 44 radionuclides contained in the waste were assumed to be released during 10,000 years, with a rate of 1 Bq/year of each radionuclide, to each of the above mentioned biospheric parts. During that time, the biospheric conditions were assumed to be the same as they are today. Doses to the critical group were calculated by exposure pathways specific for each entry-point All calculations were performed with estimation of confidence due to time-dependent parameter variation and uncertainty in input values. The results indicate that drinking water from wells is not a critical exposure pathway for all studied radionuclides. Instead, inflow of contaminated water to soil and peat bogs may be crucial for illustration of doses for geological high-level waste disposal. Improved knowledge of processes at the geosphere-biosphere interface is therefore important

  15. Deep repository for long-lived low- and intermediate-level waste in Sweden (SFL 3-5): An international peer review of SKB 's preliminary safety assessment

    Energy Technology Data Exchange (ETDEWEB)

    Chapman, N. [QuantiSci Ltd, Melton Mowbray (United Kingdom); Apted, M. [Monitor Scientific, Denver, CO (United States); Glasser, F. [Univ. of Aberdeen (United Kingdom). Dept. of Chemistry; Kessler, J. [EPRI, Inc., Palo Alto, CA (United States); Voss, C. [US Geological Survey, Reston, VA (United States)

    2000-10-01

    The SKB safety assessment of the SFL 3-5 repository (the planned deep repository for long-lived low- and intermediate level waste) can be read in two contexts: as a preliminary evaluation of the performance and design options for a repository that will not be required for perhaps forty years; or as an evaluation of a repository that might need to be sited together with the SFL 2 spent fuel repository, and whose nature and performance might thus need to be understood to a level that can be used to make wider programmatic decisions during the next five years. These two 'assessment contexts' are quite different, and an overarching issue is the fact that it was not clear to the review team which view to take. Apparently, SKB would tend towards the first context. However, it is not at all apparent to the reviewers why the second context should not be the predominant driver in the near future. The review team notes that the SFL 3-5 repository, as modelled by SKB, gives rise to potentially perceptible radionuclide releases to the environment on a timescale of hundreds of years after closure. This is in contrast to the SR 97 assessment for the SFL 2 spent fuel repository, which base scenario predicts no releases over a million year timescale. It is clear that according to SKB's SR97 and SFL3-5 analyses, for co-located facilities, it is this repository that has the potential for real radiological impacts in the immediate future. An initial recommendation from the review, is that SKB and the regulatory authorities consider which context is appropriate to the current status of the Swedish programme. This is important, because an overall impression of the reviewers is that the analysis would not be 'fit for purpose' if it were needed to assist with decision-making by SKB or the regulatory agencies. There are too many unanswered questions, and the overall impression of the safety concept is one of some fragility. Because there is no real design basis

  16. 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

  17. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 3; the groundwater pathway

    International Nuclear Information System (INIS)

    Baker, A.; Chambers, A.; Jackson, C.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  18. Derivation of parameters necessary for the evaluation of performance of sites for deep geological repositories with particular reference to bedded salt, Livermore, California. Volume I. Main text

    International Nuclear Information System (INIS)

    Ashby, J.P.; Rawlings, G.E.; Soto, C.A.; Wood, D.F.; Chorley, D.W.

    1979-12-01

    A survey of parameters to be considered in the evaluation of sites for deep geologic nuclear waste repositories is presented. As yet, no comprehensive site selection procedure or performance evaluation approach has been adopted. A basis is provided for the development of parameters by discussing both site selection and performance evaluation. Three major groups of parameters are considered in this report: geologic, mining/rock mechanics, and hydrogeologic. For each type, the role of the parameter in the evaluation of repository sites is discussed. The derivation of the parameter by measurement, correlation, inference, or other method is discussed. Geologic parameters define the framework of the repository site and can be used in development of conceptual models and the prediction of long-term performance. Methods for deriving geological parameters include mapping, surveying, drilling, geophysical investigation, and historical and regional analysis. Rock mechanics/mining parameters are essential for the prediction of short-term performance and the development of initial conditions for modeling of long-term performance. Rock mechanics/mapping parameters can be derived by field or laboratory investigation, correlation, and theoretically or empirically based inference. Hydrogeologic parameters are the most important for assessment of long-term radionuclide confinement, since transport throughout the regional hydrogeologic system is the most likely mode of radionuclide escape from geologic repositories. Hydrogeologic parameters can be derived by hydrogeologic mapping and interpretation, hydrogeologic system modeling, field measurements, and lab tests. Procedures used in determination and statistical evaluation of geologic and rock mechanics parameters are discussed

  19. Derivation of parameters necessary for the evaluation of performance of sites for deep geological repositories with particular reference to bedded salt, Livermore, California. Volume I. Main text

    Energy Technology Data Exchange (ETDEWEB)

    Ashby, J.P.; Rawlings, G.E.; Soto, C.A.; Wood, D.F.; Chorley, D.W.

    1979-12-01

    A survey of parameters to be considered in the evaluation of sites for deep geologic nuclear waste repositories is presented. As yet, no comprehensive site selection procedure or performance evaluation approach has been adopted. A basis is provided for the development of parameters by discussing both site selection and performance evaluation. Three major groups of parameters are considered in this report: geologic, mining/rock mechanics, and hydrogeologic. For each type, the role of the parameter in the evaluation of repository sites is discussed. The derivation of the parameter by measurement, correlation, inference, or other method is discussed. Geologic parameters define the framework of the repository site and can be used in development of conceptual models and the prediction of long-term performance. Methods for deriving geological parameters include mapping, surveying, drilling, geophysical investigation, and historical and regional analysis. Rock mechanics/mining parameters are essential for the prediction of short-term performance and the development of initial conditions for modeling of long-term performance. Rock mechanics/mapping parameters can be derived by field or laboratory investigation, correlation, and theoretically or empirically based inference. Hydrogeologic parameters are the most important for assessment of long-term radionuclide confinement, since transport throughout the regional hydrogeologic system is the most likely mode of radionuclide escape from geologic repositories. Hydrogeologic parameters can be derived by hydrogeologic mapping and interpretation, hydrogeologic system modeling, field measurements, and lab tests. Procedures used in determination and statistical evaluation of geologic and rock mechanics parameters are discussed.

  20. Redox front formation in an uplifting sedimentary rock sequence: An analogue for redox-controlling processes in the geosphere around deep geological repositories for radioactive waste

    International Nuclear Information System (INIS)

    Yoshida, H.; Metcalfe, R.; Yamamoto, K.; Murakami, Y.; Hoshii, D.; Kanekiyo, A.; Naganuma, T.; Hayashi, T.

    2008-01-01

    Subsurface redox fronts control the mobilization and fixation of many trace elements, including potential pollutants such as certain radionuclides. Any safety assessment for a deep geological repository for radioactive wastes needs to take into account adequately the long-term redox processes in the geosphere surrounding the repository. To build confidence in understanding these processes, a redox front in a reduced siliceous sedimentary rock distributed in an uplifting area in Japan has been studied in detail. Geochemical analyses show increased concentrations of Fe and trace elements, including rare earth elements (REEs), at the redox front, even though concentrations of reduced rock matrix constituents show little change. Detailed SEM observations revealed that fossilized microorganisms composed of amorphous granules made exclusively of Fe and Si occur in the rock's pore space. Microbial 16S rDNA analysis suggests that there is presently a zonation of different bacterial groups within the redox band, and bacterial zonation played an important role in the concentration of Fe-oxyhydroxides at the redox front. These water-rock-microbe interactions can be considered analogous to the processes occurring in the redox fronts that would develop around geological repositories for radioactive waste. Once formed, the Fe-oxyhydroxides within such a front would be preserved even after reducing conditions resume following repository closure

  1. Redox front formation in an uplifting sedimentary rock sequence: An analogue for redox-controlling processes in the geosphere around deep geological repositories for radioactive waste

    Energy Technology Data Exchange (ETDEWEB)

    Yoshida, H. [Nagoya University Museum, Material Research Section, Furocho, Nagoya 464-8602 (Japan)], E-mail: dora@num.nagoya-u.ac.jp; Metcalfe, R. [Quintessa Japan, Queen' s Tower A7-707, Minatomirai, Yokohama 220-6007 (Japan); Yamamoto, K. [Nagoya University Museum, Material Research Section, Furocho, Nagoya 464-8602 (Japan); Murakami, Y. [Japan Atomic Energy Agency (JAEA), Tono Geoscience Centre (Japan); Hoshii, D.; Kanekiyo, A.; Naganuma, T. [Hiroshima University, Higashi Hiroshima, Kagamiyama 1-4-4 (Japan); Hayashi, T. [Asahi University, Department of Dental Pharmacology, Hozumi, Gifu (Japan)

    2008-08-15

    Subsurface redox fronts control the mobilization and fixation of many trace elements, including potential pollutants such as certain radionuclides. Any safety assessment for a deep geological repository for radioactive wastes needs to take into account adequately the long-term redox processes in the geosphere surrounding the repository. To build confidence in understanding these processes, a redox front in a reduced siliceous sedimentary rock distributed in an uplifting area in Japan has been studied in detail. Geochemical analyses show increased concentrations of Fe and trace elements, including rare earth elements (REEs), at the redox front, even though concentrations of reduced rock matrix constituents show little change. Detailed SEM observations revealed that fossilized microorganisms composed of amorphous granules made exclusively of Fe and Si occur in the rock's pore space. Microbial 16S rDNA analysis suggests that there is presently a zonation of different bacterial groups within the redox band, and bacterial zonation played an important role in the concentration of Fe-oxyhydroxides at the redox front. These water-rock-microbe interactions can be considered analogous to the processes occurring in the redox fronts that would develop around geological repositories for radioactive waste. Once formed, the Fe-oxyhydroxides within such a front would be preserved even after reducing conditions resume following repository closure.

  2. A model for the analysis of a normal evolution scenarios for a deep geological granite repository for high-level radioactive waste

    International Nuclear Information System (INIS)

    Cormenzana Lopez, J.L.; Cunado, M.A.; Lopez, M.T.

    1996-01-01

    The methodology usually used to evaluate the behaviour of deep geological repositories for high-level radioactive wastes comprises three phases: Identification of factors (processes, characteristics and events) that can affect the repository. Generation of scenarios. In general, a normal evolution scenario (Reference Scenario) and various disruptive scenarios (earthquake, human intrusion, etc) are considered. Evaluation of the behaviour of the repository in each scenario. The normal evolution scenario taking into account all factors with a high probability of occurrence is the first to be analysed. The performance assessment of behaviour being carried out by ENRESA for the AGP Granite has led to the identification of 63 of these factors. To analyse repository behaviour in the normal evolution scenario, it is necessary to first of all create an integrated model of the global system. This is a qualitative model including the 63 factors identified. For a global view of a such a complex system, it is very useful to graphically display the relationship between factors in an Influence Diagram. This paper shows the Influence Diagram used in the analysis of the AGP Granite Reference Scenario. (Author)

  3. An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

    Energy Technology Data Exchange (ETDEWEB)

    King, F. [Integrity Corrosion Consulting Limited (Canada); Lilja, C. [Svensk Kaernbraenslehantering AB, Stockholm (Sweden); Pedersen, K. [Microbial Analytics Sweden AB, Molnlycke (Sweden); Pitkaenen, P.; Vaehaenen, M.

    2012-07-15

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid. (orig.)

  4. An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

    International Nuclear Information System (INIS)

    King, Fraser; Lilja, Christina; Pedersen, Karsten; Pitkaenen, Petteri; Vaehaenen, Marjut

    2010-12-01

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid

  5. An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

    Energy Technology Data Exchange (ETDEWEB)

    King, Fraser (Integrity Corrosion Consulting Limited (Canada)); Lilja, Christina (Svensk Kaernbraenslehantering AB (Sweden)); Pedersen, Karsten (Microbial Analytics Sweden AB (Sweden)); Pitkaenen, Petteri; Vaehaenen, Marjut (Posiva Oy (Finland))

    2010-12-15

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid

  6. An update of the state-of-the-art report on the corrosion of copper under expected conditions in a deep geologic repository

    International Nuclear Information System (INIS)

    King, F.; Lilja, C.; Pedersen, K.; Pitkaenen, P.; Vaehaenen, M.

    2012-07-01

    Copper has been the corrosion barrier of choice for the canister in the Swedish and Finnish, nuclear waste disposal programmes for over 30 years. During that time many studies have been carried out on the corrosion behaviour of copper under conditions likely to exist in an underground nuclear waste repository located in the Fenno-Scandian bedrock. This review is a summary of what has been learnt about the long-term behaviour of the corrosion barrier during this period and what the implications of this knowledge are for the predicted service life of the canisters. The review is based on the existing knowledge from various nuclear waste management programs around the world and from the open literature. Various areas are considered: the expected evolution of the geochemical and microbiological conditions in the groundwater and of the repository environment, the thermodynamics of copper corrosion, corrosion during the operational phase and in the bentonite prior to saturation of the buffer by groundwater, general and localised corrosion following saturation of the compacted bentonite buffer, stress corrosion cracking, radiation effects, the implications of corrosion on the service life of the canister, and areas for further study. This report is an updated version of that originally published in 2001/2002. The original material has been supplemented by information from studies carried out over the last decade. The conclusion drawn from this review is that the original prediction made in 1978 of canister lifetimes exceeding 100,000 years remains valid. (orig.)

  7. Shear-induced Fracture Slip and Permeability Change. Implications for Long-term Performance of a Deep Geological Repository

    International Nuclear Information System (INIS)

    Min, Ki-Bok; Stephansson, Ove

    2009-03-01

    Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in jointed rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this project are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. The first part of the study is about the evolution of thermal stresses in the rock during the lifetime of the repository. Critical sections of heat generated stresses around the repository are selected and classified. Fracture data from Forsmark is used to establish fracture network models (DFN) and the models are subjected to the sum of virgin stress and thermal stresses and the shear slip and related permeability change are studied. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the corners of the repository. In the

  8. Shear-induced Fracture Slip and Permeability Change. Implications for Long-term Performance of a Deep Geological Repository

    Energy Technology Data Exchange (ETDEWEB)

    Min, Ki-Bok (School of Civil, Environmental and Mining Engineering, Univ. of Adelaide, Adelaide (Australia)); Stephansson, Ove (Steph Rock Consulting AB, Berlin (Germany))

    2009-03-15

    Opening of fractures induced by shear dilation or normal deformation can be a significant source of fracture permeability change in jointed rock, which is important for the performance assessment of geological repositories for spent nuclear fuel. As the repository generates heat and later cools the fluid-carrying ability of the rocks becomes a dynamic variable during the lifespan of the repository. Heating causes expansion of the rock close to the repository and, at the same time, contraction close to the surface. During the cooling phase of the repository, the opposite takes place. Heating and cooling together with the virgin stress can induce shear dilation of fractures and deformation zones and change the flow field around the repository. The objectives of this project are to examine the contribution of thermal stress to the shear slip of fracture in mid- and far-field around a KBS-3 type of repository and to investigate the effect of evolution of stress on the rock mass permeability. The first part of the study is about the evolution of thermal stresses in the rock during the lifetime of the repository. Critical sections of heat generated stresses around the repository are selected and classified. Fracture data from Forsmark is used to establish fracture network models (DFN) and the models are subjected to the sum of virgin stress and thermal stresses and the shear slip and related permeability change are studied. In the first part of this study, zones of fracture shear slip were examined by conducting a three-dimensional, thermo-mechanical analysis of a spent fuel repository model. Stress evolutions of importance for fracture shear slip are: (1) comparatively high horizontal compressive thermal stress at the repository level, (2) generation of vertical tensile thermal stress right above the repository, (3) horizontal tensile stress near the surface, which can induce tensile failure, and generation of shear stresses at the corners of the repository. In the

  9. Suggestions for locations for the surface installations required for deep-lying repositories; standortareale fuer die oberflaechenanlage von tiefenlagern -- vorschlaege zur diskussion

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-01-15

    This booklet issued by the Swiss National Cooperative for the Disposal of Radioactive Waste NAGRA takes a look at the various factors involved in the selection of locations for surface installations that are required for the operation of deep-lying nuclear waste repositories. The method chosen for the selection of possible locations for surface installations is explained and the necessity for such installations is discussed. The requirements placed on such a location are discussed and the various locations chosen for further consideration are noted. The evaluation phases involved in the selection of sites are described. The proposed surface installations are noted and the proposed structures for both repository types - for highly radioactive wastes and for low and medium active wastes - are described.

  10. Hydrogeologic modelling in support of a proposed deep geologic repository in Canada for low and intermediate level radioactive waste - 16264

    International Nuclear Information System (INIS)

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

    2009-01-01

    A Deep Geologic Repository (DGR) for Low and Intermediate Level radioactive waste has been proposed by Ontario Power Generation for the Bruce Nuclear Power Development site in Ontario, Canada. The DGR is to be constructed at a depth of about 680 m below ground surface within the argillaceous Ordovician limestone of the Cobourg Formation. This paper describes a regional-scale geologic conceptual model for the DGR site and analyzes flow system evolution using the FRAC3DVSOPG flow and transport model. This provides a framework for the assembly and integration of site-specific geo-scientific data that explains and illustrates the factors that influence the predicted long-term performance of the geosphere barrier. In the geologic framework of the Province of Ontario, the Bruce DGR is located at the eastern edge of the Michigan Basin. Borehole logs covering Southern Ontario combined with site specific data have been used to define the structural contours at the regional and site scale of the 31 sedimentary strata that may be present above the Precambrian crystalline basement rock. The regional-scale domain encompasses an 18.500 km 2 region extending from Lake Huron to Georgian Bay. The groundwater zone below the Devonian is characterized by units containing stagnant water having high concentrations of total dissolved solids that can exceed 300 g/l. The computational sequence involves the calculation of steady-state density independent flow that is used as the initial condition for the determination of pseudo-equilibrium for a density dependent flow system that has an initial TDS distribution developed from observed data. Long-term simulations that consider future glaciation scenarios include the impact of ice thickness and permafrost. The selection of the performance measure used to evaluate a groundwater system is important. The traditional metric of average water particle travel time is inappropriate for geologic units such as the Ordovician where solute transport is

  11. Generic description of facilities at the shaft head (auxiliary entrance installations) of deep geological repositories; Generische Beschreibung von Schachtkopfanlagen (Nebenzugangsanlagen) geologischer Tiefenlager

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2016-10-15

    In a deep geological repository, the access structures function as the link between the surface and the installations and structures at the disposal level. In the planned implementation scenarios, at least two access structures will be in operation up to the time of closure of the repository. The radioactive waste will be transported via the main access from the surface to the disposal level during emplacement operations. For the construction and operation of a deep geological repository, additional access structures are required. These auxiliary accesses and the associated surface infrastructure (e.g. shaft head installations) form the subject of this report. To provide as broad and comprehensive a description as possible, seven types of auxiliary access facilities are defined; these are characterised in line with the current status of planning and their functions and impacts are described. During construction, operation and dismantling of auxiliary access facilities, the usual conventional safety measures (inter alia) have to be observed (e.g. groundwater protection, fire prevention, facility security, accident prevention). Regarding the 'Ordinance on Protection against Major Accidents' no large quantities of hazardous materials, i.e. above the corresponding threshold quantities, are to be expected in the auxiliary access facilities. Proper handling and compliance with applicable regulations in all phases will ensure no hazard to humans and the environment. As no handling of radioactive materials is foreseen in the auxiliary access facilities, and because exhaust air and waste water from the controlled zones of a repository will, in principle, be removed via the main access and not the auxiliary accesses, a safety-relevant emission of radioactive substances and transport of contaminated material can be ruled out for the auxiliary access facilities during both normal operation and also in the case of an accident. Based on the information presented in

  12. The evolving UK strategy for the management of intermediate level waste to enable disposal to a deep geological repository - a UKAEA/BNFL/NIREX perspective

    International Nuclear Information System (INIS)

    Wratten, A.J.; Allan, D.F.; Palmer, J.D.

    1996-01-01

    The objective of this paper is to describe the development of BNFL's and UKAEA's strategies for managing Intermediate Level Waste (ILW) against the background of the evolving national strategy. The impact of the loss of the sea disposal route is addressed together with the challenge of designing waste conditioning plants in parallel with the evolving technical specification for the Nirex deep repository. What has been achieved and is Planned in terms of plant provisioning is described, together with the lessons that have been learned in striving to achieve optimum design solutions. (author)

  13. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 2; hydrogeological conceptual model development - effective parameters and calibration appendix

    International Nuclear Information System (INIS)

    Jackson, C.; Watson, S.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  14. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 1: hydrogeological model development - conceptual basis and data

    International Nuclear Information System (INIS)

    Degnan, P.; Littleboy, A.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  15. Nirex 97 an assessment of the post-closure performance of a deep waste repository at Sellafield. Volume 2; hydrogeological conceptual model development - effective parameters and calibration

    International Nuclear Information System (INIS)

    Jackson, C.; Watson, S.

    1997-01-01

    United Kingdom Nirex Limited ('Nirex') is responsible for providing and managing facilities for the safe disposal of intermediate and certain low-level radioactive waste (ILW and LLW respectively). Government policy is that the preferred disposal route for such wastes is a deep geological repository. The repository concept aims to use a combination of natural and engineered barriers to achieve the necessary degree of long-term isolation and containment of the radioactive wastes. Since 1987, Nirex has carried out an extensive technical programme directed at the science of safe disposal. The work comprises a research programme into the long-term performance of waste forms and the engineered and natural barriers, including the characterisation of candidate geological settings to assess their suitability to host a deep waste repository ('DWR'). Between mid-1991 and March 1997 the geological characterisation programme was concentrated on establishing the suitability, or otherwise, of a candidate site at Sellafield, West Cumbria. In July 1994, as part of a detailed site investigation programme, Nirex applied for planning permission to develop an underground Rock Characterisation Facility (RCF) at Longlands Farm near Sellafield. This application was rejected by the planning authority and Nirex's appeal against that decision led to a local planning inquiry which ran from September 1995 until February 1996. In line with the Inspector's Report, in March 1997 the Nirex appeal was dismissed by the Secretary of State for the Environment. The Company's response to that decision, and its readiness to contribute to the new government's review of the way forward, are described in the Nirex Annual Report for 1996-97. This report - Nirex 97 - is founded on the understanding developed through the Nirex technical programme. It reports the outcome of an assessment of the post-closure safety performance, over hundreds of thousands of years, of a repository system located in a potential

  16. The Swedish final repository for reactor waste (SFR). A summary of the SFR project with special emphasis on the near-field assessments

    International Nuclear Information System (INIS)

    Carlsson, J.

    1988-01-01

    The first phase of the final repository for reactor waste (SFR) is scheduled for operation in April 1988. The construction work is finished and preoperational tests are in progress. Impact on the environment from SFR is analysed in a final safety report. This paper gives a summary of the design and performance of SFR. Assessments, made for the analysises of the long term safety, are given with special emphasis on the near-field. As a conclusion from the analysises, the dose commitment to the most affected individual during the post-closure period, has proved to constitute only an insignificant contribution to the natural radioactive environment of the area

  17. Characterization of natural organic matter in bentonite clays for potential use in deep geological repositories for used nuclear fuel

    International Nuclear Information System (INIS)

    Marshall, Michaela H.M.; McKelvie, Jennifer R.; Simpson, André J.; Simpson, Myrna J.

    2015-01-01

    Highlights: • We studied the composition of natural organic matter in bentonite clay. • Biomarker results indicate a predominance of plant-derived organic matter. • Aromatic and aliphatic compounds were observed in NMR spectra. • Degradation ratios suggest that organic matter is highly altered. • The natural organic matter in bentonite clay is predominantly recalcitrant. - Abstract: The Nuclear Waste Management Organization (NWMO) is developing a Deep Geological Repository (DGR) to contain and isolate used nuclear fuel in a suitable rock formation at a depth of approximately 500 m. The design concept employs a multibarrier system, including the use of copper-coated used fuel containers, surrounded by a low-permeability, swelling clay buffer material within a low permeability, stable host rock environment. The natural organic matter (NOM) composition of the bentonite clays being considered for the buffer material is largely uncharacterized at the molecular-level. To gain a better understanding of the NOM in target clays from Wyoming and Saskatchewan, molecular-level methods (biomarker analysis, solid-state 13 C NMR and solution-state 1 H nuclear magnetic resonance (NMR)) were used to elucidate the structure and sources of NOM. Organic carbon content in three commercially available bentonites analyzed was low (0.11–0.41%). The aliphatic lipid distribution of the clay samples analyzed showed a predominance of higher concentration of lipids from vascular plants and low concentrations of lipids consistent with microbial origin. The lignin phenol vanillyl acid to aldehyde ratio (Ad/Al) for the National sample indicated an advanced state of lignin oxidation and NOM diagenesis. The 13 C NMR spectra were dominated by signals in the aromatic and aliphatic regions. The ratio of alkyl/O-alkyl carbon ranged from 7.6 to 9.7, indicating that the NOM has undergone advanced diagenetic alteration. The absence lignin-derived phenols commonly observed in CuO oxidation

  18. Low-ph injection grout for deep repositories. Summary report from a co-operation project between NUMO (Japan), Posiva (Finland) and SKB (Sweden)

    Energy Technology Data Exchange (ETDEWEB)

    Boden, A. (ed.) [SwedPower Ab, Stockholm (Sweden); Sievaenen, U. (ed.) [JP-Suoraplan Oy, Vantaa (Finland)

    2006-02-15

    This report summarises results achieved in the joint SKB, Posiva and NUMO project 'Injection grout for deep repositories'. The work has been carried out in four subprojects with SKB and Posiva as responsible for two sub-projects each. This report summarises the original reporting. Posiva was responsible for the studies on low-pH cementitious grout, while SKB was responsible for the studies on non-cementitious grout. The work was done by literature surveys, laboratory analyses and field tests A result of the project is that there are both low-pH cementitious material for grouting larger fractures ((>-) 100 {mu}m) and non-cementitious material for grouting smaller fractures ((<-) 100 {mu}m) that will, after further optimisation work, be recommended for grouting of deep repositories. This project concentrated on the technical development of properties for the low pH grouts. Long-term safety and environmental aspects and durability of materials were preliminarily considered. Continued evaluations have to be carried out. (orig.)

  19. Methodology for the development of scenarios for the evaluation of the behaviour of a deep geological repository for high-level radioactive waste in a granite formation

    International Nuclear Information System (INIS)

    Cortes Martin, A.; Alonso, J.; Gonzalez, E.

    1996-01-01

    In time, deep geological repositories for radioactive waste undergo significant environmental changes caused either by natural processes or by human actions. In view of a long-term safety analysis, it is fundamental to identify all the possible evolutions of the system. This process is denominated scenario development. This paper deals with the methodology used to generate scenarios within the framework of the AGP (Deep Geological Repository) project for assessing behaviour in granite medium. It begins with a brief description of the methodology used to identify the relevant factors for the safety analysis on the system. It then presents the details of the actual scenario-generating methodology which consists of dividing the entire system into barrier states or subsystems a graphic procedure by means of which the factors are represented in relation to their predictable impact or extent of their effect on the subsystems. This methodology is a good tool for displaying and grouping the most significant scenarios for the subsequent analysis of consequences. (Author)

  20. Application of Ga-Al discrimination plots in identification of high strength granitic host rocks for deep geological repository of high level radioactive waste

    International Nuclear Information System (INIS)

    Bajpai, R.K.; Narayan, P.K.; Trivedi, R.K.; Purohit, M.K.

    2010-01-01

    The permanent disposal of vitrified high level wastes and in some cases even spent fuel, is being planned in specifically designed and built deep geological repository located in the depth range of 500-600m in appropriate host rock at carefully selected sites. Such facilities are expected to provide very long term isolation and confinement to the disposed waste by means of long term mechanical stability of such structures that results from very high strength and homogeneity of the chosen rock, geochemical compatible environment around the disposed waste and general lack of groundwater. In Indian geological repository development programme, granites have been selected as target host rock and large scale characterization studies have been undertaken to develop database of mineralogy, petrology, geochemistry and rock mechanical characteristics. The paper proposes a new approach for demarcation of high strength homogeneous granite rocks from within an area of about 100 square kilometres wherein a cocktail of granites of different origins with varying rock mass characteristics co exists. The study area is characterised by the presence of A, S and I type granites toughly intermixed. The S type granites are derived from sedimentary parent material and therefore carry relics of parent fabric and at times undigested material with resultant reduction in their strength and increased inhomogeneity. On the other hand I type varieties are derived from igneous parents and are more homogeneous with sufficient strength. The A type granites are emplaced as molten mass in a complete non-tectonic setting with resultant homogeneous compositions, absence of tectonic fabric and very high strength. Besides they are silica rich with less vulnerability to alterations with time. Thus A type granites are most suited for construction of Deep Geological Repository. For developing a geochemical approach for establishing relation between chemical compositions and rock strength parameters, a

  1. Ex-vessel melt-coolant interactions in deep water pool: Studies and accident management for Swedish BWRs

    International Nuclear Information System (INIS)

    Sienicki, J.J.; Chu, C.C.; Spencer, B.W.; Frid, W.; Loewenhielm, G.

    1993-01-01

    In Swedish BWRs having an annular suppression pool, the lower drywell beneath the reactor vessel is flooded with water to mitigate against the effects of melt release into the drywell during a severe accident. The THIRMAL code has been used to analyze the effectiveness of the water pool to protect lower drywell penetrations by fragmenting and quenching the melt as it relocates downward through the water. Experiments have also been performed to investigate the benefits of adding surfactants to the water to reduce the likelihood of fine-scale debris formation from steam explosions. This paper presents an overview of the accident management approach and surfactant investigations together with results from the THIRMAL analyses

  2. Ex-vessel melt-coolant interactions in deep water pool: studies and accident management for Swedish BWRs

    International Nuclear Information System (INIS)

    Chu, C.C.; Sienicki, J.J.; Spencer, B.W.; Frid, W.; Loewenhielm, G.

    1995-01-01

    In Swedish BWRs having an annular suppression pool, the lower drywell beneath the reactor vessel is flooded with water to mitigate against the effects of melt release into the drywell during a severe accident. The THIRMAL-1 code has been used to analyze the effectiveness of the water pool to protect lower drywell penetrations by fragmenting and quenching the melt as it relocates downward through the water. Experiments have also been performed to investigate the benefits of adding surfactants to the water to reduce the likelihood of fine-scale debris formation from steam explosions. This paper presents an overview of the accident management approach and surfactant investigations together with results from the THIRMAL-1 analyses. A description of the modeling incorporated in THIRMAL-1 is also provided. (orig.)

  3. Technical expertise on the safety of the proposed geological repository sites. Planning for geological deep repositories, step 1; Sicherheitstechnisches Gutachten zum Vorschlag geologischer Standortgebiete. Sachplan geologische Tiefenlager, Etappe 1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2010-01-15

    On October 17, 2010, on request of those Swiss government institutions responsible for the disposal of radioactive wastes, the National Co-operative for the Disposal of Radioactive Waste (NAGRA) presented its project concerning geological sites for the foreseen disposal of radioactive wastes to the Federal Authorities. According to the present disposal concept, two types of repository are foreseen: one for highly radioactive wastes (HAA) and the other for low radioactive and intermediate-level radioactive wastes (SMA). If a site fulfils the necessary conditions for both HAA as well as for SMA, a combined site for both types of waste may be chosen. As a qualified control authority in Switzerland, the Federal Nuclear Safety Inspectorate (ENSI) has to examine the quality of the NAGRA proposals from the point of view of the nuclear safety of the sites. The project for deep underground waste disposal first defines the process and the criteria according to which sites for the geological storage of all types of radioactive wastes in Switzerland have to be chosen. The choice is based on the actual knowledge of Swiss geology. After dividing the wastes into SMA and HAA, some large-scale areas are to be identified according to their suitability from the geological and tectonic points of view. NAGRA's division of waste into SMA and HAA is based on calculations of the long-term safety for a broad range of different rock types and geological situations and takes the different properties of all waste types into account. As a conclusion, a small portion of SMA has to be stored with {alpha}-toxic wastes in the HAA repository. The estimation of the total volume of wastes to be stored is based on 60 years of operation of the actual nuclear power plants, augmented with the wastes from possible replacement plants with a total power of 5 GW{sub e} during a further 60 years. The safety concept of the repository is based on passive systems using technical and natural barriers. The

  4. Literature study on the state-of-the-art for the marking of deep geological repositories for radioactive wastes

    International Nuclear Information System (INIS)

    Buser, M.

    2010-05-01

    This comprehensive report for the Swiss Federal Office of Energy (SFOE) summarises the results of a literature study on the marking of repositories for radioactive wastes. Knowledge gained and ideas discussed in Switzerland on the subject are collated and discussed. Various associated topics such as safety, risk and marking technologies are examined. 28 topics in six thematic blocks are presented and discussed. Not only marking concepts are discussed, but also questions on human and society-related factors, traditionalising information transfer and susceptibility to wrong interpretation are examined. The author is of the opinion that no reusable materials be used either in the repositories themselves or for their marking in order to help prevent future generations coming into contact with the dangerous wastes

  5. Foreign materials in a deep repository for spent nuclear fuels; Fraemmande material i ett djupfoervar foer anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    Jones, C.; Christiansson, Aa.; Wiborgh, M. [Kemakta Konsult AB, Stockholm (Sweden)

    1999-12-01

    The effects of foreign substances introduced into a spent-fuel repository are reviewed. Possible impacts on processes and barrier-functions are examined, and the following areas are identified: Corrosion of the spent-fuel canister through the presence of sulfur and substances that favor microbial growth; impacts on the bentonite properties through the presence of cations as calcium, potassium and iron; radionuclide transport through the presence of complex-formers and surface-active substances.

  6. Three-dimensional Geological and Geo-mechanical Modelling of Repositories for Nuclear Waste Disposal in Deep Geological Structures

    International Nuclear Information System (INIS)

    Fahland, Sandra; Hofmann, Michael; Bornemann, Otto; Heusermann, Stefan

    2008-01-01

    To prove the suitability and safety of underground structures for the disposal of radioactive waste extensive geo-scientific research and development has been carried out by BGR over the last decades. Basic steps of the safety analysis are the geological modelling of the entire structure including the host rock, the overburden and the repository geometry as well as the geo-mechanical modelling taking into account the 3-D modelling of the underground structure. The geological models are generated using the special-construction openGEO TM code to improve the visualisation an d interpretation of the geological data basis, e.g. borehole, mine, and geophysical data. For the geo-mechanical analysis the new JIFE finite-element code has been used to consider large 3-D structures with complex inelastic material behaviour. To establish the finite-element models needed for stability and integrity calculations, the geological models are simplified with respect to homogenous rock layers with uniform material behaviour. The modelling results are basic values for the evaluation of the stability of the repository mine and the long-term integrity of the geological barrier. As an example of application, the results of geological and geo-mechanical investigations of the Morsleben repository based on 3-D modelling are presented. (authors)

  7. Aspects of the studies for construction of a deep geological repository in Republic of Bulgaria. Concept for development of a specialized database for the purposes of siting and design of a deep geological repository in Republic of Bulgaria

    International Nuclear Information System (INIS)

    Tomov, E.; Yordanova, V.

    2009-01-01

    The strategy for the management of spent nuclear fuel and radioactive waste there are considered three options for spent fuel management : Transportation of the all spent fuel for storage and reprocessing; Removal of a part of the spent fuel for storage and reprocessing and store the rest in the repository for long-term dry storage for at least 50 years, i e postponement of the decision making; Transportation of the spent fuel to Russia for storage and processing, return of the high-level activity waste from processing for storage and disposal in Bulgaria, further storage of the spent fuel at NPP Kozloduy

  8. Stakeholder involvement in Swedish nuclear waste management

    International Nuclear Information System (INIS)

    Elam, Mark; Sundqvist, Goeran

    2006-09-01

    This report concerning Swedish nuclear waste management has been produced as part of a cross national research project: CARL - A Social Science Research Project into the Effects of Stakeholder involvement on Decision-Making in Radioactive Waste Management. Besides Sweden, the participating countries are Belgium, Canada, Finland, Slovenia and United Kingdom. A social science research team, working for three years, is in the first phase conducting research in their own countries in order to produce 6 country reports. During the next years the focus will shift to comparisons of stakeholder involvement practices in the participating countries. The report addresses current practices of Swedish nuclear waste management and their historical development. The main focus is on past, current and emerging patterns of stakeholder involvement in the siting of a deep repository for the final disposal of Sweden's spent nuclear fuel. The general questions attended to in the report are: Who are the main stakeholders, and how have they emerged and gained recognition as such? What are the issues currently subject to stakeholder involvement and how have these been decided upon? How is stakeholder involvement organized locally and nationally and how has this changed over time? How has stakeholder involvement gained acceptance as an activity of value in the siting of major waste facilities? The report have attempted to show the development of stakeholder involvement in the siting of a final repository for Sweden's spent nuclear fuel as resembling something other than a straightforward linear process of improvement and refinement. Stakeholder involvement has developed, over the past 15 years or so, into something more like a patchwork of different shapes and forms. Some of the forces that may well contribute to the further elaboration of the patchwork of stakeholder involvement have been pointed out, contingently modifying once more its overall colour and orientation. Questions have been

  9. Stakeholder involvement in Swedish nuclear waste management

    Energy Technology Data Exchange (ETDEWEB)

    Elam, Mark; Sundqvist, Goeran [Goeteborg Univ. (Sweden). Section for Science and Technology Studies

    2006-09-15

    This report concerning Swedish nuclear waste management has been produced as part of a cross national research project: CARL - A Social Science Research Project into the Effects of Stakeholder involvement on Decision-Making in Radioactive Waste Management. Besides Sweden, the participating countries are Belgium, Canada, Finland, Slovenia and United Kingdom. A social science research team, working for three years, is in the first phase conducting research in their own countries in order to produce 6 country reports. During the next years the focus will shift to comparisons of stakeholder involvement practices in the participating countries. The report addresses current practices of Swedish nuclear waste management and their historical development. The main focus is on past, current and emerging patterns of stakeholder involvement in the siting of a deep repository for the final disposal of Sweden's spent nuclear fuel. The general questions attended to in the report are: Who are the main stakeholders, and how have they emerged and gained recognition as such? What are the issues currently subject to stakeholder involvement and how have these been decided upon? How is stakeholder involvement organized locally and nationally and how has this changed over time? How has stakeholder involvement gained acceptance as an activity of value in the siting of major waste facilities? The report have attempted to show the development of stakeholder involvement in the siting of a final repository for Sweden's spent nuclear fuel as resembling something other than a straightforward linear process of improvement and refinement. Stakeholder involvement has developed, over the past 15 years or so, into something more like a patchwork of different shapes and forms. Some of the forces that may well contribute to the further elaboration of the patchwork of stakeholder involvement have been pointed out, contingently modifying once more its overall colour and orientation. Questions

  10. Specifications for the development of a fully three-dimensional numerical groundwater model for regional mass transport of radionuclides from a deep waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Prickett, T.A.

    1980-04-01

    Specifications are given which are necessary to develop a three-dimensional numerical model capable of simulating regional mass transport of radionuclides from a deep waste repository. The model to be developed will include all of the significant mass transport processes including flow, chemical, and thermal advection, mechanical dispersion, molecular diffusion, ion exchange reactions, and radioactive decay. The model specifications also include that density and viscosity fluid properties be functions of pressure, temperature, and concentration and take into account fluid and geologic heterogenieties by allowing possible assignment of individual values to every block of the model. The model specifications furthermore include the repository shape, input/output information, boundary conditions, and the need for documentation and a user's manual. Model code validation can be accomplished with the included known analytical or laboratory solutions. It is recommended that an existing finite-difference model (developed by INTERCOMP and INTERA, Inc.) be used as a starting point either as an acceptable basic code for modification or as a pattern for the development of a completely different numerical scheme. A ten-step plan is given to outline the general procedure for development of the code.

  11. Specifications for the development of a fully three-dimensional numerical groundwater model for regional mass transport of radionuclides from a deep waste repository

    International Nuclear Information System (INIS)

    Prickett, T.A.

    1980-04-01

    Specifications are given which are necessary to develop a three-dimensional numerical model capable of simulating regional mass transport of radionuclides from a deep waste repository. The model to be developed will include all of the significant mass transport processes including flow, chemical, and thermal advection, mechanical dispersion, molecular diffusion, ion exchange reactions, and radioactive decay. The model specifications also include that density and viscosity fluid properties be functions of pressure, temperature, and concentration and take into account fluid and geologic heterogenieties by allowing possible assignment of individual values to every block of the model. The model specifications furthermore include the repository shape, input/output information, boundary conditions, and the need for documentation and a user's manual. Model code validation can be accomplished with the included known analytical or laboratory solutions. It is recommended that an existing finite-difference model (developed by INTERCOMP and INTERA, Inc.) be used as a starting point either as an acceptable basic code for modification or as a pattern for the development of a completely different numerical scheme. A ten-step plan is given to outline the general procedure for development of the code

  12. Final report on uncertainties in the detection, measurement, and analysis of selected features pertinent to deep geologic repositories

    International Nuclear Information System (INIS)

    1978-01-01

    Uncertainties with regard to many facets of repository site characterization have not yet been quantified. This report summarizes the state of knowledge of uncertainties in the measurement of porosity, hydraulic conductivity, and hydraulic gradient; uncertainties associated with various geophysical field techniques; and uncertainties associated with the effects of exploration and exploitation activities in bedded salt basins. The potential for seepage through a depository in bedded salt or shale is reviewed and, based upon the available data, generic values for the hydraulic conductivity and porosity of bedded salt and shale are proposed

  13. Expectations, open questions to be addressed in the workshop within the context of a deep geological repository in clay formations

    International Nuclear Information System (INIS)

    Landais, Patrick

    2013-01-01

    Precise knowledge of the clay properties in the various domains concerned by the construction feasibility, the exploitation phase of repository facilities, as well as the long term evolution of the waste and of its environment is of crucial importance in assessing the performance and the safety of the various radioactive waste disposal concepts. The knowledge to be acquired on clays as such goes well beyond solely the field of disposal of radioactive waste. For both, clay formations or bentonites in engineered barriers, the characterization in a continuous way from the nanometer to the micrometer, of their internal structure and the study of the associated physico-chemical phenomena is a fundamental issue. It aims for explaining: The 'Initial state' of the clays, in particular for the clay formations: the nature of the mechanical, hydraulic and geochemical processes, in a broad sense, and the way these processes were involved during the geological history of these formations, The fundamental processes involved by physico-chemical or hydraulic stresses, related to the evolution of the repository at the macroscopic scale. The choice of the characterization scale and relevant modeling is of first importance in the approaches leading to the establishment of the models of representation. Various research works pointed to experimental difficulties in quantifying the microstructure of the clay rocks at scales smaller than a micrometer, because of technical/instrumental limitations. This lack of knowledge at small scales does not allow to fully connect all the Thermal-hydrological-mechanical-chemical (THMC) mechanisms and to integrate them into an up-scaling approach. There already exist conceptual models and experimental approaches to describe the microstructure of argillaceous formations in terms of porosity and texture. Examples on the undisturbed Callovo-Oxfordian (COx) argillite are given in this paper. Questions and objectives to be addressed during the

  14. Institutional Repositories as Infrastructures for Long-Term Preservation

    Science.gov (United States)

    Francke, Helena; Gamalielsson, Jonas; Lundell, Björn

    2017-01-01

    Introduction: The study describes the conditions for long-term preservation of the content of the institutional repositories of Swedish higher education institutions based on an investigation of how deposited files are managed with regards to file format and how representatives of the repositories describe the functions of the repositories.…

  15. SR-can: preliminary feedback to canister fabrication, repository design and future R and D

    International Nuclear Information System (INIS)

    Hedin, A.; Sellin, P.

    2007-01-01

    This paper discusses preliminary feedback from SKB's on-going safety assessment SR-Can, to he finalized in 2006. The assessment, which is not part of a formal licence application, is an important step towards the SR-Site assessment to be delivered in 2008 and which will support a licence application for a Swedish deep repository for spent nuclear fuel. The SR-Can assessment will use data from the initial stage of the on-going site investigations at the two candidate sites at Forsmark and Oskarshamn. Review comments on SR-Can from Swedish authorities are expected in the summer of 2007 and these will be taken into account when preparing the SR-Site assessment. An Interim version of the SR-Can report was produced in September 2004 and has been reviewed by the Swedish authorities supported by an international review team. The assessment concerns a KBS 3 repository for which the key safety related features can be summarised in the primary safety function isolation and the secondary function retardation. The isolation function is more prominent in the KBS 3 method compared to many other repository concepts. (authors)

  16. Safety-relevant assessment concerning the proposals for investigations in proposed locations for stage 3 of the deep geological repositories project; Sicherheitstechnisches Gutachten zum Vorschlag der in Etappe 3 SGT weiter zu untersuchenden geologischen Standortgebiete - Sachplan geologische Tiefenlager, Etappe 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2017-04-15

    This comprehensive report published by the Swiss Federal Nuclear Safety Inspectorate ENSI examines the proposals made by the Swiss National Cooperative for the disposal of Radioactive Waste (NAGRA) concerning proposed locations for deep waste repositories. Important basic considerations to be made when narrowing down the choice of host rock types and the selection of possible locations are discussed. These include, amongst others, safety concepts for the repositories, geological models and technical feasibility of repositories in Opalinus Clay, Brown Dogger layers and marl. The properties of various host rocks are discussed. Methods to be used in choosing at least two possible sites for repositories are considered. Also, the radioactive dosage to be expected at the various sites proposed is discussed. A safety-relevant comparison of the sites is made and an overall assessment is presented. The locations proposed for surface facilities at three proposed locations are discussed. The report is completed with an appendix containing tables and a list of relevant expert reports.

  17. Memorandum concerning further information on the constructional feasibility of proposed locations for stage 2 of the deep geological repositories project; Nachforderung zum Indikator „Tiefenlage im Hinblick auf bautechnische Machbarkeit“ in Etappe 2 SGT

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2015-11-15

    This memorandum published by the Swiss Federal Nuclear Safety Inspectorate ENSI examines proposals made by the Swiss National Cooperative for the disposal of Radioactive Waste (NAGRA). Further information concerning the technical feasibility of deep repositories for nuclear wastes and their maximum depth is requested. ENSI requests from NAGRA that the minimum geotechnical requirements on the repositories and an assessment on their maximum depth be stated. Five main areas where more information is required are listed. Provisional assessment results on maximum repository depth are quoted and the associated requirements on supplementary data required are listed. Data on basic rock mechanics are requested and requirements on the evaluation of maximum repository depth are discussed. The document is completed with a comprehensive list of relevant references.

  18. Swiss plans for deep geological repositories for radioactive wastes - Basics for communication at the localities affected; Sachplan geologische Tiefenlager. Forschungsprojekt 'Kommunikation mit der Gesellschaft': Grundlagen fuer die Kommunikation in den Standortregionen

    Energy Technology Data Exchange (ETDEWEB)

    Gallego Carrera, D.; Renn, O.; Dreyer, M.

    2009-06-15

    This report for the Swiss Federal Office of Energy (SFOE) discusses the concept of how information concerning deep geological repositories for radioactive wastes should be presented and communicated to those in the areas which have been designated as potential sites for the repositories. Communication basics based on scientific knowledge in this area are discussed. The importance of a concept for general communication and risk-communication as a particular challenge are discussed. Trust and transparency are quoted as being indispensable in this connection. Ways of dealing with various target audiences and the media are examined. The report is concluded with a check-list that deals with important questions arising from the process of communicating information on deep geological repositories for radioactive wastes

  19. Backfilling and closure of the deep repository. Phase 3 - pilot tests to verify engineering feasibility. Geotechnical investigations made on unsaturated backfill materials

    International Nuclear Information System (INIS)

    Johannesson, Lars-Erik

    2008-12-01

    The investigations described in this report is a part of the third phase of the joint SKB-Posiva project 'Backfilling and Closure of the Deep Repository, BACLO'. The overall objective of the BACLO project is to develop backfilling concept for the deep repository that can be configured to meet SKB's and Posiva's requirements in the chosen repository sites. The project was divided into four phases, of which two have already been performed. The second phase of the BACLO project consisted of laboratory tests and deepened analyses of the investigated backfill materials and methods and resulted in recommendation to focus on the development and testing of the block placement concept with three alternative backfill materials. The third phase investigations comprise of laboratory and large-scale experiments aiming at testing the engineering feasibility of the concept. In addition, how site-specific constraints, backfilling method and materials affect the long-term functions of the barriers will be described and analysed in order to set design specifications for the backfill. The third phase of the BACLO project is divided into several subprojects. The work described in this report belongs to subproject 1 concerning processes during installation and saturation of the backfill that may affect the long-term function of the bentonite buffer and the backfill itself. One of the main functions of backfill is to restrict buffer expansion which can lead to decrease in buffer density in the deposition hole. The criterion used as a basis for the Baclo investigations was that the buffer density at saturation should not be below 1,950 kg/m 3 at the level of the canister. The same criterion was applied for the work described in this report. The upward swelling of the buffer and the enclosed compression of the backfill was first studied assuming that both the buffer and the backfill were saturated. The main objective of this work was to study a case where the buffer is fully saturated

  20. Backfilling and closure of the deep repository. Phase 3 - pilot tests to verify engineering feasibility. Geotechnical investigations made on unsaturated backfill materials

    Energy Technology Data Exchange (ETDEWEB)

    Johannesson, Lars-Erik (Clay Technology AB, Lund (Sweden))

    2008-12-15

    The investigations described in this report is a part of the third phase of the joint SKB-Posiva project 'Backfilling and Closure of the Deep Repository, BACLO'. The overall objective of the BACLO project is to develop backfilling concept for the deep repository that can be configured to meet SKB's and Posiva's requirements in the chosen repository sites. The project was divided into four phases, of which two have already been performed. The second phase of the BACLO project consisted of laboratory tests and deepened analyses of the investigated backfill materials and methods and resulted in recommendation to focus on the development and testing of the block placement concept with three alternative backfill materials. The third phase investigations comprise of laboratory and large-scale experiments aiming at testing the engineering feasibility of the concept. In addition, how site-specific constraints, backfilling method and materials affect the long-term functions of the barriers will be described and analysed in order to set design specifications for the backfill. The third phase of the BACLO project is divided into several subprojects. The work described in this report belongs to subproject 1 concerning processes during installation and saturation of the backfill that may affect the long-term function of the bentonite buffer and the backfill itself. One of the main functions of backfill is to restrict buffer expansion which can lead to decrease in buffer density in the deposition hole. The criterion used as a basis for the Baclo investigations was that the buffer density at saturation should not be below 1,950 kg/m3 at the level of the canister. The same criterion was applied for the work described in this report. The upward swelling of the buffer and the enclosed compression of the backfill was first studied assuming that both the buffer and the backfill were saturated. The main objective of this work was to study a case where the buffer is

  1. Local Communities' Expectations and Demands on Monitoring and the Preservation of Records, Knowledge and Memory of a Deep Geological Repository

    International Nuclear Information System (INIS)

    2014-01-01

    This report explores the role, needs and expectations of local communities regarding monitoring and RK and M preservation of radioactive waste management facilities, in particular deep geological repositories. It was developed through both field and desk research. A questionnaire survey to FSC members was undertaken in July and August 2012, followed by interviews with a broad range of involved stakeholders. A brief update survey in August and September 2013 gathered replies from a subset of countries. A literature review was carried out, focusing on FSC publications and other documents and publications found through internet or suggested by interviewees. After a brief presentation of the study rationale and methodology in section 1, section 2 reviews the FSC literature on aspects related to RK and M and monitoring. In section 3 the report identifies concerns and expectations of local communities regarding monitoring in the different phases of the repository life cycle and in the different national contexts, according to the results gathered from the survey and interviews undertaken as part of this project. The fourth section discusses how RK and M preservation may emerge as a subject of debate with local stakeholders in different countries in the years to come. Section 5 recognises that monitoring and RK and M preservation potentially serve to build and maintain confidence in the long-term safety of deep geological repositories. Finally, the concept of oversight is considered in section 6 as a term that embraces monitoring and RK and M, and its interpretation in different reports is illustrated. Final reflections, with some conclusions, are provided in section 7. Four appendixes are offered. Appendix I summarises in a table the design features of a radioactive waste management facility that may help the memory of the site to be preserved over generations, as suggested in NEA (2007). Appendix II reports statements related with monitoring and RK and M preservation in

  2. Evaluation of heat propagation from a KBS-3 type deep repository for Aberg, Beberg and Ceberg in SKB's SR 97

    International Nuclear Information System (INIS)

    Goblet, Patrick; Marsily, Ghislain de

    2000-01-01

    The following conclusions and remarks may be drawn from this review work: The phenomenology of heat propagation in the complex system of a repository is generally well understood, and permits a reliable prediction of temperature evolution. Some simplifications such as the representation of incomplete saturation of the buffer are justified at the present stage of knowledge, and do not seem to impair the reliability of the results. These simplification may become unnecessary in the future as experimental work presently going on leads to a better predicting capacity of these mechanisms. Important parameters (thermal conductivity and heat capacity) are known through a large number of measurements, and furthermore do not span a wide range. The main uncertainty seems to lie in the near field parameters (description of the contact between container and buffer, thermal conductivity of unsaturated bentonite). Generally speaking, the weak point of thermal modelling is generally not in the representation of a particular component, but in the heat transfer between different components. Although no systematic sensitivity analysis was performed in this study, the various situations modelled do give an idea on the effect of varying parameters such as thermal conductivity, heat capacity, initial heat output. The modelling work presented is consistent with the phenomenology described. A powerful computing capacity allows a detailed description of mechanisms at two different scales. However, the transition from one scale (unit cell) to the other (global scale) would deserve a more rigorous analysis. From a reviewers' viewpoint, the description of calculation cases is generally not sufficiently detailed to judge precisely the results, or to try and duplicate them, should this be needed. While this situation is acceptable in a generic exercise such as SR 97, a more detailed description would be required in a real site assessment. Apart from thermal parameters and repository location

  3. Use of Geohydrologic Response Functions in the assessment of deep nuclear waste repositories: assessment of effectiveness of geologic isolation systems

    International Nuclear Information System (INIS)

    Nelson, R.W.

    1981-05-01

    Geohydrologic Response Functions (GRFs) interrelate the three vital factors needed in the repository decision-making process: the quantity, arrival time, and location of contamination reaching the biosphere. GRFs further focus attention upon two related and additive parameters: the initial delay time and delay spread time. After the principal site selection, the GRFs may be applied to obtain more detailed performance evaluations concerning specific nuclides or waste components, specific results for various types of accidental release, and effects of a variety of contaminant source terms or leach models. The response functions may be applied to consider contaminant reductions and delays through material sorption as well as through a variety of other interactions and effects

  4. Selection of the situations taken into account for the safety demonstration of a repository in deep geological formations - French regulatory guidance and IPSN modelling experience

    International Nuclear Information System (INIS)

    Escalier des Orres, P.; Greneche, D.

    1993-01-01

    A regulatory guidance has been recently set up in France for the safety assessment of radwaste deep geological disposal: the present paper deals with the methodology related to the safety demonstration of such a disposal, particularly the situations to be taken into account to address the potential evolution of the repository under natural or human induced events. This approach, based on a selection of events considered as reasonably envisageable, relies on a reference scenario characterized by a great stability of the geological formation and on hypothetical situations corresponding to the occurrence of random events of natural origin or of conventional nature. The implementation of this methodology within the framework of the IPSN (Protection and Nuclear Safety Institute, CEA) participation in the CEC EVEREST project is addressed. This programme consists in the evaluation of the sensitivity of the radiological consequences associated to deep radwaste disposal systems to the different elements of the performance assessment (scenario characteristics, phenomena, physico-chemical parameters) in three types of geological formations (granite, salt and clay).(author). 11 refs., 3 tabs

  5. Role of bacteria as biocolloids in the transport of actinides from a deep underground radioactive waste repository

    International Nuclear Information System (INIS)

    Francis, A.J.; Gillow, J.B.; Dodge, C.J.; Dunn, M.; Mantione, K.; Strietelmeier, B.A.; Pansoy-Hjelvik, M.E.; Papenguth, H.W.

    1998-01-01

    We investigated the interaction of dissolved actinides 232 Th, 238 U, 237 Np, 239 Pu, and 243 Am, with a pure and a mixed culture of halophilic bacteria isolated from the waste isolation pilot plant repository under anaerobic conditions to evaluate their potential transport as biocolloids from the waste site. The sizes of the bacterial cells studied ranged from 0.54 x 0.48 μm to 7.7 x 0.67 μm (1 x w). Using sequential microfiltration, we determined the association of actinides with free-living (mobile) bacterial cells suspended in a fluid medium containing NaCl or MgCl 2 brine, at various phases of their growth cycles. The number of suspended bacteria ranged from 10 6 to 10 9 cells ml -1 . The amount of actinide associated with the suspended cell fraction (calculated as mol cell -1 ) was very low: Th, 10 -12 ; U, 10 -15 -10 -18 ; Np, 10 -15 -10 -19 ; Pu, 10 -18 -10 -21 ; and Am, 10 -18 -10 -19 ; and it varied with the bacterial culture studied. The differences in the association are attributed to the extent of bioaccumulation and biosorption by the bacteria, pH, the composition of the brine, and the speciation and bioavailability of the actinides. (orig.)

  6. Effect Of Up-Scaling On The Study Of The Steel/Bentonite Interface In A Deep Geological Repository

    International Nuclear Information System (INIS)

    Torres Alvarez, Elena; Turrero, Maria Jesus; Martin, Pedro Luis; Escribano, Alicia

    2008-01-01

    Deep geological disposal is the most accepted management option for High Level Nuclear Wastes. The multi-barrier system for the isolation of high-level radioactive waste includes the concept of the spent fuel encapsulated in canisters of carbon steel. Corrosion phenomena affect the integrity of the canister and can modify the chemical environment either at the interface or in the bentonite pore water. The experimental studies conducted by CIEMAT are focused on the iron canister corrosion products interaction with the bentonite system and are based on a series of short term and medium term experiments conceived at different scales, from conventional laboratory experiments and experiments in cylindrical cells, to those specifically designed 3D mock up experiments, the so called 'GAME (Geochemical Mock up experiments) scale'. The results obtained from the up-scaling could be a useful tool to understand the key processes at the steel/bentonite interface and the later modelling work. (authors)

  7. Effect Of Up-Scaling On The Study Of The Steel/Bentonite Interface In A Deep Geological Repository

    Energy Technology Data Exchange (ETDEWEB)

    Torres Alvarez, Elena; Turrero, Maria Jesus; Martin, Pedro Luis; Escribano, Alicia [CIEMAT, Avda. Complutense 22, 28040, Madrid (Spain)

    2008-07-01

    Deep geological disposal is the most accepted management option for High Level Nuclear Wastes. The multi-barrier system for the isolation of high-level radioactive waste includes the concept of the spent fuel encapsulated in canisters of carbon steel. Corrosion phenomena affect the integrity of the canister and can modify the chemical environment either at the interface or in the bentonite pore water. The experimental studies conducted by CIEMAT are focused on the iron canister corrosion products interaction with the bentonite system and are based on a series of short term and medium term experiments conceived at different scales, from conventional laboratory experiments and experiments in cylindrical cells, to those specifically designed 3D mock up experiments, the so called 'GAME (Geochemical Mock up experiments) scale'. The results obtained from the up-scaling could be a useful tool to understand the key processes at the steel/bentonite interface and the later modelling work. (authors)

  8. Swedish subseabed store - phase 1 nears completion

    International Nuclear Information System (INIS)

    Daglish, James

    1987-01-01

    The paper concerns the storage of radioactive waste in the subseabed in Sweden. The wastes are low- and intermediate-level reactor wastes arising from the Swedish nuclear power programme. The repository is a cavern which has been excavated under the seabed in the Baltic Sea, about a kilometre out from shore. The specifications of the repository are given, along with the volume of the radioactive wastes to be stored in it. (UK)

  9. FEBEX project: full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock. Final report

    International Nuclear Information System (INIS)

    Alberdi, J.; Barcala, J. M.; Campos, R.; Cuevas, A. M.; Fernandez, E.

    2000-01-01

    FEBEX has the multiple objective of demonstrating the feasibility of manufacturing, handling and constructing the engineered barriers and of developing codes for the thermo-hydro-mechanical and thermo-hydro-geochemical performance assessment of a deep geological repository for high level radioactive wastes. These objectives require integrated theoretical and experimental development work. The experimental work consists of three parts: an in situ test, a mock-up test and a series of laboratory tests. The experiments is based on the Spanish reference concept for crystalline rock, in which the waste capsules are placed horizontally in drifts surround by high density compacted bentonite blocks. In the two large-scale tests, the thermal effects of the wastes were simulated by means of heaters; hydration was natural in the in situ test and controlled in the mock-up test. The large-scale tests, with their monitoring systems, have been in operation for more than two years. the demonstration has been achieved in the in situ test and there are great expectation that numerical models sufficiently validated for the near-field performance assessment will be achieved. (Author)

  10. Thermal dimensioning of the deep repository. Influence of canister spacing, canister power, rock thermal properties and nearfield design on the maximum canister surface temperature

    International Nuclear Information System (INIS)

    Hoekmark, Harald; Faelth, Billy

    2003-12-01

    The report addresses the problem of the minimum spacing required between neighbouring canisters in the deep repository. That spacing is calculated for a number of assumptions regarding the conditions that govern the temperature in the nearfield and at the surfaces of the canisters. The spacing criterion is that the temperature at the canister surfaces must not exceed 100 deg C .The results are given in the form of nomographic charts, such that it is in principle possible to determine the spacing as soon as site data, i.e. the initial undisturbed rock temperature and the host rock heat transport properties, are available. Results of canister spacing calculations are given for the KBS-3V concept as well as for the KBS-3H concept. A combination of numerical and analytical methods is used for the KBS-3H calculations, while the KBS-3V calculations are purely analytical. Both methods are described in detail. Open gaps are assigned equivalent heat conductivities, calculated such that the conduction across the gaps will include also the heat transferred by radiation. The equivalent heat conductivities are based on the emissivities of the different gap surfaces. For the canister copper surface, the emissivity is determined by back-calculation of temperatures measured in the Prototype experiment at Aespoe HRL. The size of the different gaps and the emissivity values are of great importance for the results and will be investigated further in the future

  11. Proposal for the classification of scenarios for deep geological repositories in probability classes; Vorschlag zur Einordnung von Szenarien fuer tiefe geologische Endlager in Wahrscheinlichkeitsklassen

    Energy Technology Data Exchange (ETDEWEB)

    Beuth, Thomas

    2013-03-15

    The provided report was elaborated in the framework of the project 3609R03210 ''Research and Development for Proof of the long-term Safety of Deep Geological Repositories''. It contains a proposal for a methodology that enables the assignment of developed scenarios in the frame of Safety Cases to defined probability classes. The assignment takes place indirectly through the categorization of the defining relevant factors (so-called FEP: Features, Events and Processes) of the respective scenarios also in probability classes. Therefore, decision trees and criteria were developed for the categorization of relevant factors in classes. Besides the description of the methodology another focal point of the work was the application of the method taking into account a defined scenario. By means of the scenario the different steps of the method and the decision criteria were documented, respectively. In addition, potential subjective influences along the path of decisions regarding the assignment of scenarios in probability classes were identified.

  12. Social transactions with future generations for the management of high level radioactive waste in deep repositories: Reflections on institutional control and retrievability

    International Nuclear Information System (INIS)

    Heriard Dubreuil, G.; Schieber, C.; Schneider, T.; Viala, M.

    1999-01-01

    The management of high level radioactive waste and spent fuel is a key issue and one of the most sensitive aspect of radioactive waste management. Recognising that it is the responsibility of our generation to find a way to isolate the waste, deep geological disposals have been envisaged to provide a definitive solution to the problem, in order to avoid 'undue burden on future generations'. However, even if they are buried, the wastes still exist and human intrusion is still possible as well as releases into the environment in the very far future. At the same time, the ongoing reflections on the ethical aspects of disposals show that it is of great worth that we guarantee future generations the same right of control and responsibility that we ourselves enjoy. This paper presents some reflections on the social transactions associated with the management and design of geological repositories. It is focused on the mission of institutional control in the transmission to future generation of a safety patrimony, composed of the know-how and techniques that permit the human community to 'domesticate' and control the risk. As it appears that the efficiency and the confidence in the control system rely mainly on the capability of implementing corrective actions, some considerations on the role, the consequences and the implementation of retrievability are also presented

  13. Could the landscape preserve traces of a deep underground nuclear waste repository over the very long term? What we can learn from the archaeology of ancient mines

    International Nuclear Information System (INIS)

    Harmand, Dominique; BRULHET, Jacques

    2015-01-01

    Prof. Dominique Harmand presented a study conducted on behalf of Andra that focused on the archaeology of abandoned underground mines in order to illustrate how ancient human activities have left traces in the landscape. Old mines often have left some traces at surface such as slag heaps and parts of shafts over relatively long timescales, up to thousands of years. Geological disposal projects are equally likely to leave traces in the landscape over time. In the case of the French Cigeo project (Centre industriel de stockage geologique), research into the past and future geological evolution of the area shows that traces of heads of shafts and inclined tunnels, and filled excavations will likely still exist at surface in the distant future. However, as these traces could be confused with other human and natural traces of all ages, steps need to be taken to ensure that they are correctly interpreted. A suggested approach to facilitate the correct interpretation in the future consists in marking the site, and especially its long-lasting traces, with long-lived anthropological elements, such as small engraved ceramic pieces. These could be placed around the repository's surface buildings, but also in drill holes that would be a few metres deep. As a result of the natural erosion of the site, they would progressively reach the surface of the area in the long term

  14. FEBEX project: full-scale engineered barriers experiment for a deep geological repository for high level radioactive waste in crystalline host rock

    Energy Technology Data Exchange (ETDEWEB)

    Alberid, J; Barcala, J M; Campos, R; Cuevas, A M; Fernandez, E [Ciemat. Madrid (Spain)

    2000-07-01

    FEBEX has the multiple objective of demonstrating the feasibility of manufacturing, handling and constructing the engineered barriers and of developing codes for the thermo-hydro-mechanical and thermo-hydro-geochemical performance assessment of a deep geological repository for high level radioactive wastes. These objectives require integrated theoretical and experimental development work. The experimental work consists of three parts: an in situ test, a mock-up test and a series of laboratory tests. The experiments is based on the Spanish reference concept for crystalline rock, in which the waste capsules are placed horizontally in drifts surround by high density compacted bentonite blocks. In the two large-scale tests, the thermal effects of the wastes were simulated by means of heaters; hydration was natural in the in situ test and controlled in the mock-up test. The large-scale tests, with their monitoring systems, have been in operation for more than two years. the demonstration has been achieved in the in situ test and there are great expectation that numerical models sufficiently validated for the near-field performance assessment will be achieved. (Author)

  15. Swedish Nuclear Waste Management from Theory to Practice

    International Nuclear Information System (INIS)

    Holmqvist, Magnus

    2008-01-01

    The programme has evolved from a project of a few experts drawing up the outline of what today is a comprehensive programme of research, development, demonstration, design, construction and operation of facilities for radioactive waste management. The Swedish programme was greatly influenced at an early stage by political actions, which included placing the responsibility with the reactor owners to demonstrate safe disposal of spent nuclear fuel and also to fund a disposal programme. The response of the reactor owners was to immediately start the KBS project. Its third report in 1983 described the KBS-3 concept, which is still the basis for SKB's deep geological repository system. Thus, this year is the 25th anniversary of the creation of the well-known KBS-3 concept. The SKB programme for nuclear waste management is today divided in two sub programmes; LILW Programme and the Nuclear Fuel Programme. The LILW Programme is entering into a new phase with the imminent site investigations for the expansion of the SFR LILW repository, which is in operation since 1988, to accept also decommissioning waste. The expansion of SFR is driven by a government decision urging SKB to investigate when a licensing of a repository for decommissioning waste can be made

  16. Sellafield repository design concept

    International Nuclear Information System (INIS)

    1998-01-01

    Between 1989 and 1997, UK Nirex Ltd carried out a programme of investigations to evaluate the potential of a site adjacent to the BNFL Sellafield works to host a deep repository for the United Kingdom's intermediate-level and certain low-level radioactive waste. The programme of investigations was wound down following the decision in March 1997 to uphold the rejection of the Company's planning application for the Rock Characterisation Facility (RCF), an underground laboratory which would have allowed further investigations to confirm whether or not the site would be suitable. Since that time, the Company's efforts in relation to the Sellafield site have been directed towards documenting and publishing the work carried out. The design concept for a repository at Sellafield was developed in parallel with the site investigations through an iterative process as knowledge of the site and understanding of the repository system performance increased. This report documents the Sellafield repository design concept as it had been developed, from initial design considerations in 1991 up to the point when the RCF planning application was rejected. It shows, from the context of a project at that particular site, how much information and experience has been gained that will be applicable to the development of a deep waste repository at other potential sites

  17. The Swedish concept for disposal of waste arising from the operation of nuclear power plants

    International Nuclear Information System (INIS)

    Carlsson, J.

    1996-01-01

    The Swedish nuclear power programme consists of 12 reactors producing 50% of the electricity in Sweden. It is stated by law that a waste producer has to make sure a safe handling and disposal of his radioactive waste. SKB is performing necessary activities on behalf of the waste producers. A system is in operation today that will manage all the radioactive waste produced in the country. The system consists of a transportation system, a final repository for operational waste and an interim storage facility for spent fuel. What remains to be built is an encapsulation plant for the spent fuel and a deep repository for final disposal of spent fuel and other long lived waste. All costs for managing and disposal of radioactive waste is paid by the owners of the nuclear power utilities. (author) 9 figs

  18. Stakeholder Involvement in Swedish Nuclear Waste Management

    International Nuclear Information System (INIS)

    Elam, Mark; Sundqvist, Goeran

    2006-01-01

    The focus in this paper is on past, current and emerging patterns of stakeholder involvement in the siting of a deep repository for final disposal of Sweden's spent nuclear fuel. In particular, we concentrate on how the two municipalities of Oskarshamn and Oesthammar have acted as engaged stakeholders, and have gained recognition as such, in the siting process. In general: How has stakeholder involvement gained acceptance as an activity of value in the siting of major waste facilities? What are the issues currently subject to stakeholder involvement and how have these been decided upon? An effect of the history of nuclear activity in Oskarshamn and Oesthammar is that stakeholder involvement over a final repository can be divided into social and technical issues. Both municipalities have out of tradition, as part of their social acceptance of a new repository, been prepared to surrender extended involvement in key safety issues. They have been prepared to do this because they also see themselves being able to delegate these safety issues to the government authorities SSI and SKI. These two authorities have been acceptable to the two municipalities as their legitimate 'technological guardians'. As physical geology re-enters the siting process for a deep repository, Oskarshamn appear more prepared to break with tradition than Oesthammar. Oskarshamn are currently demanding transparency from SKB in relation to the exact technical and geological criteria they will use to choose between them and Oesthammar as a repository site. In contrast to Oesthammar, Oskarshamn are preparing with the expected help of SKI and SSI to dispute their geology and its relation to nuclear safety with SKB if they consider it necessary. If Oskarshamn act to draw safety issues in relation to alternative methods and sitings into the EIA process where might this lead? As environmental groups now enter the process (three groups were granted funding in the first round - 2005) the character of site

  19. Swedish projects

    International Nuclear Information System (INIS)

    Thunell, J.

    1993-01-01

    The main sources of the financing of Swedish research on gas technology are listed in addition to names of organizations which carry out this research. The titles and descriptions of the projects carried out are presented in addition to lists of reports published with information on prices. (AB)

  20. Repositories; Repositorios

    Energy Technology Data Exchange (ETDEWEB)

    Freire, Carolina Braccini; Tello, Cledola Cassia Oliveira de [Centro de Desenvolvimento da Tecnologia Nuclear (CDTN/CNEN-MG), Belo Horizonte, MG (Brazil)]. E-mails: cbf@cdtn.br; tellocc@cdtn.br

    2007-11-15

    The use of the nuclear energy is increasing in all areas. Then the radioactive waste management is in continuous development to comply the national and international established requirements. The final objective is to assure that it will not have any contamination of the public or the environmental, and that the exposition doses will be lower than the radiological protection limits. The multi barrier concept for the repository is internationally recognized. Among the repository types, the most used are: near surface, geological formations and of deposition in rock cavities. This article explains the concept and the types of repository and gives some examples of them. (author)

  1. The Radiological and Thermal Characteristics of Fission Waste from a Deep-Burn Fusion-Fission Hybrid (LIFE) and Implications for Repository Performance

    International Nuclear Information System (INIS)

    Shaw, H.F.; Blink, J.; Farmer, J.; Latkowski, J.; Kramer, K.

    2009-01-01

    photon transport calculations were performed using MCNP5. Burnup calculations were performed using a modified version of Monteburns 2.0. The nuclear data used were from ENDF/B-VII. Additional details of the burn calculations can be found in. For comparison to spent fuel from light water reactors (LWRs), we use the projected initial inventory of PWR and BWR fuels (current average age of 23 years since discharge) used for the Yucca Mountain Project Final Environmental Impact Statement. The decay of this initial inventory to 1 million years was calculated using ORIGEN2. The hybrid system considered here would have generated ∼44 GWe-yr of energy at 99% FIMA. The energy generated per MT is therefore about 1100 MWe-yr/MT. In contrast, using average burnups of 41.2 GWt-day/MT and 33.6 GWt-day/MT for the PWR and BWR fuel slated for disposal at Yucca Mtn., and assuming a thermal electric conversion efficiency of ∼33%, the total energy generated by the 68,000 MT 'Yucca Mtn. inventory' is ∼2500 GWe-yr, or ∼37 MWe-yr/MT, which is ∼30 times less energy per MT than the waste from the hybrid. Clearly, relative to the current once-through fuel cycle, the use of a deep-burn hybrid to generate electricity would significantly reduce the need for repository capacity.

  2. Investigations on the populations of introduced and resident micro-organisms in deep repositories and their effects on containment of radioactive wastes

    International Nuclear Information System (INIS)

    West, J.M.; Arme, S.C.; Christofi, N.; Philp, J.C.

    1986-01-01

    The present study has sought to establish basic facts concerning the importance of microbial presence in a radioactive waste repository. These are: (1) establishing the presence of microbes in relevant geological formations; (2) defining the importance of isolated groups to radioactive waste containment; (3) establishing the ability of sampled microbes to tolerate repository environmental conditions; (4) conducting preliminary work on microbial ability to influence radionuclide migration characteristics; (5) attempting basic modelling of the effects of micro-organisms on containment and radionuclide migration. Results have shown that micro-organisms of significance (e.g. sulphur cycle bacteria) are present in relevant formations. These groups can tolerate repository conditions and influence migration studies. Their growth, however, would seem to be limited by the nutrient availability. Simple modelling has concentrated on conservative calculations on the constraints of maximum effects of microbial contamination of a high-level waste repository

  3. The post-closure radiological safety case for a spent fuel repository in Sweden - An international peer review of the SKB license-application study of March 2011

    International Nuclear Information System (INIS)

    2012-01-01

    Sweden is at the forefront among countries developing plans for a deep geological repository of highly radioactive waste. There is no such repository in operation yet worldwide, but Sweden, Finland and France are approaching the licensing stage. At the request of the Swedish government, the NEA organised an international peer review of the post-closure radiological safety case produced by the Swedish Nuclear Fuel and Waste Management Company (SKB) in support of the application for a general licence to construct and operate a spent nuclear fuel geological repository in the municipality of Oesthammar. The purpose of the review was to help the Swedish government, the public and relevant organisations by providing an international reference regarding the maturity of SKB's spent fuel disposal programme vis-a-vis best practices in long-term disposal safety and radiological protection. The International Review Team (IRT) consisted of ten international specialists, who were free of conflict of interest with the SKB and brought complementary expertise to the review. This report provides the background and findings of the international peer review. The review's findings are presented at several levels of detail in order to be accessible to both specialist and non-specialist readers

  4. Simulation of hygric and thermal processes at ventilated tunnel surfaces of a deep geological repository in the Callovo-Oxfordian clay

    International Nuclear Information System (INIS)

    Poppei, J.; Mayer, G.; Hubschwerlen, N.; Pepin, G.; Wendling, J.

    2010-01-01

    Document available in extended abstract form only. The calculation of vapour and heat exchange in drifts is a fundamental task when designing the ventilation system for a deep geological repository in the Callovo-Oxfordian clay. In general, it requires a complex numerical modelling of transient (forced) convective and conductive heat and fluid transport in both the ventilated drifts and the adjacent rock mass. The humidity of the air in the drifts depends - along with the meteorological conditions at the entrance - mostly on the thermal-hygric transitional conditions on the exposed rock surface of the drift walls. Some portions receive water influx while others receive heat influx from the wastes which have already been emplaced in the host rock beyond the drifts. The coupling between the transport processes in the host rock and the transfer processes along drift wall is treated in a simplified manner: The processes described by coefficients for heat (Nusselt number) and vapour (Sherwood number) both depend on the ventilation velocity (Reynolds number). In Poppei et al., 2009, we discuss an approach involving supportive TOUGH2 computations for coupling the complex transport problems in the host rock with the air flow in a simplified manner. The results obtained with TOUGH2 were processed and applied for the transient analysis of temperature and humidity changes of the ventilation air in a 1D approach along the ventilation path. Furthermore, the analysis of the evaporation along the drift wall was supported by a one-dimensional radial-symmetric EOS9 model. The results of the TOUGH2 computations with different Sherwood numbers were parameterized accordingly. The prevailing humidity along the drift wall was then determined with an iterative approach whereby the humidity was controlled either by the ventilation (i.e. through the Sherwood number) or the leakage capacity of the host rock. Finally, the humidity changes in the ventilation air were derived from the computed

  5. Final disposal of high-level radioactive waste in deep boreholes. An evaluation based on recent research on the bedrock at great depths

    International Nuclear Information System (INIS)

    Aahaell, Karl-Inge

    2006-05-01

    New knowledge in hydrogeology and boring technology have opened the possibility to use deep boreholes as a repository for the Swedish high-level radioactive wastes. The determining property is that the repository can be housed in the stable bedrock at levels where the ground water has no contact with the biosphere and disposal and sealing can take place without disturbing the ground water stratification outside the disposal area. An advantage compared to a shallow repository of KBS-3 type, that is now being planned in Sweden, is that a borehole repository is likely to be technologically more robust, since the concept 'deep boreholes' seems to admit such a deep disposal that the entire disposal area would be surrounded by stable density-layered ground water, while a KBS-3 repository would be surrounded by moving ground water in contact with level close to the surface. This hydrological difference is of great importance for the safety in scenarios with leaching of radioactive substances. A deep repository is also less vulnerable for effects from natural events such as glaciation and earthquakes as well as from technological mishaps and terrorist actions. A crucial factor is, however, that the radioactive waste can be disposed of, in a secure way, at the intended depth, which will require new research and technology development

  6. Taking a non-conflicting approach to the siting of a deep geological repository or Why introducing the right of 'veto' for the affected municipalities is not a good solution

    International Nuclear Information System (INIS)

    Handrlica, Jakub

    2012-01-01

    Various communities, especially ecological initiatives, demand that municipalities affected by planned siting of a Czech deep geological repository for the disposal of spent nuclear fuel and radioactive wastes be given the right to veto such plans. It is shown that the legal tools available to municipalities for defending their legitimate interests within the current siting licensing procedure are sufficient and that the introduction of the right of veto into the Czech law would be a non-conceptual and unprecedented intervention into existing juridical and procedural institutes. (orig.)

  7. Final deposition of high-level nuclear waste in very deep boreholes. An evaluation based on recent research of bedrock conditions at great depths

    International Nuclear Information System (INIS)

    Aahaell, Karl-Inge

    2007-01-01

    This report evaluates the feasibility of very deep borehole disposal of high-level nuclear waste, e.g., spent nuclear fuel, in the light of recent technological developments and research on the characteristics of bedrock at extreme depths. The evaluation finds that new knowledge in the field of hydrogeology and technical advances in drilling technology have advanced the possibility of using very deep boreholes (3-5 km) for disposal of the Swedish nuclear waste. Decisive factors are (1) that the repository can be located in stable bedrock at a level where the groundwater is isolated from the biosphere, and (2) that the waste can be deposited and the boreholes permanently sealed without causing long-term disturbances in the density-stratification of the groundwater that surrounds the repository. Very deep borehole disposal might offer important advantage compared to the relatively more shallow KBS approach that is presently planned to be used by the Swedish nuclear industry in Sweden, in that it has the potential of being more robust. The reason for this is that very deep borehole disposal appears to permit emplacement of the waste at depths where the entire repository zone would be surrounded by stable, density-stratified groundwater having no contact with the surface, whereas a KBS-3 repository would be surrounded by upwardly mobile groundwater. This hydro-geological difference is a major safety factor, which is particularly apparent in all scenarios that envisage leakage of radioactive substances. Another advantage of a repository at a depth of 3 to 5 km is that it is less vulnerable to impacts from expected events (e.g., changes in groundwater conditions during future ice ages) as well as undesired events (e.g. such as terrorist actions, technical malfunction and major local earthquakes). Decisive for the feasibility of a repository based on the very deep borehole concept is, however, the ability to emplace the waste without failures. In order to achieve this

  8. Repository design

    Energy Technology Data Exchange (ETDEWEB)

    John, C M

    1982-01-01

    Various technical issues of radioactive waste design are addressed in this paper. Two approaches to repository design considered herein are: (1) design to minimize the disturbance of the hot rock; and (2) designs that intentionally modify the hot rock to insure better containment of the wastes. The latter designs range from construction of a highly impermeable barrier around a spherical cavern to creating a matrix of tunnels and boreholes to form a cage within which the hydraulic pressure is nearly constant. Examples of these design alternatives are described in some detail. It is concluded that proposed designs for repositories illustrate that performance criteria considered acceptable for such facilities can be met by appropriate site selection and repository engineering. With these technically feasible design concepts, it is also felt that socioeconomic and institutional issues can be better resolved. (BLM)

  9. Long-term degradation of organic polymers under conditions found in deep repositories for low and intermediate-level wastes; Langzeit-Degradation von organischen Polymeren unter SMA-Tiefenlagerbedingungen

    Energy Technology Data Exchange (ETDEWEB)

    Warthmann, R.; Mosberger, L.; Baier, U.

    2013-06-15

    On behalf of Nagra, the Environmental Biotechnology Section of the Zürich University of Applied Sciences in Wädenswil investigated the potential for microbiological degradation of organic polymers under the conditions found in a deep geological repository for low- and intermediate-level waste (L/ILW). The existing scientific literature on the topic was analysed, some thermodynamic calculations carried out and input was elicited from internationally recognised experts in the field. The study was restricted to a few substances which, in terms of mass, are most significant in the Swiss L/ILW inventory; these are polystyrene (PS), polyvinyl chloride (PVC), other plastics and bitumen. There were no clear indications in the literature that the polymer structure of synthetic polymers is biodegraded under anoxic conditions. However, functional groups of ion exchangers and plasticizers in plastics are considered to be readily available and biodegradable. The greatest obstacle to biological degradation of synthetic polymers is depolymerisation to produce labile monomers. As energy is generally required for such breakdown, the chances of this process taking place outside the cells are very low. In so far as they are present, monomers are, in principle, anaerobically biodegradable. Thermodynamic considerations indicate that degradation of synthetic polymers under repository conditions is theoretically possible. However, the degradation of polystyrene is very close to thermodynamic equilibrium and the usable energy for microorganisms would barely be sufficient. Under high H2 partial pressures, it is predicted that there will be a thermodynamic inhibition of anaerobic degradation, as certain interim steps in degradation are endergonic. The starting conditions for microbial growth in a deep repository are unfavourable in terms of availability of water and prevailing pH values. Practically no known microorganisms can tolerate the combination of these conditions; most known

  10. Swedish nuclear waste efforts

    International Nuclear Information System (INIS)

    Rydberg, J.

    1981-09-01

    After the introduction of a law prohibiting the start-up of any new nuclear power plant until the utility had shown that the waste produced by the plant could be taken care of in an absolutely safe way, the Swedish nuclear utilities in December 1976 embarked on the Nuclear Fuel Safety Project, which in November 1977 presented a first report, Handling of Spent Nuclear Fuel and Final Storage of Vitrified Waste (KBS-I), and in November 1978 a second report, Handling and Final Storage of Unreprocessed Spent Nuclear Fuel (KBS II). These summary reports were supported by 120 technical reports prepared by 450 experts. The project engaged 70 private and governmental institutions at a total cost of US $15 million. The KBS-I and KBS-II reports are summarized in this document, as are also continued waste research efforts carried out by KBS, SKBF, PRAV, ASEA and other Swedish organizations. The KBS reports describe all steps (except reprocessing) in handling chain from removal from a reactor of spent fuel elements until their radioactive waste products are finally disposed of, in canisters, in an underground granite depository. The KBS concept relies on engineered multibarrier systems in combination with final storage in thoroughly investigated stable geologic formations. This report also briefly describes other activities carried out by the nuclear industry, namely, the construction of a central storage facility for spent fuel elements (to be in operation by 1985), a repository for reactor waste (to be in operation by 1988), and an intermediate storage facility for vitrified high-level waste (to be in operation by 1990). The R and D activities are updated to September 1981

  11. Injection grout for deep repositories. Subproject 1: LowpH cementitious grout for larger fractures, leach testing of grout mixes and evaluation of the long-term safety

    International Nuclear Information System (INIS)

    Vuorinen, U.; Lehikoinen, J.; Imoto, Harutake; Yamamoto, Takeshi; Cruz Alonso, M.

    2005-10-01

    Constructing an underground disposal facility for spent nuclear fuel deep in bedrock requires lowpH cement-based injection grout, because assured data of the extent of a possible high-pH plume in saturated bedrock conditions is lacking. In this work low-pH grout mixes of new design were subjected to leach testing. Before chosen to leach testing the grout mixes had to fulfil certain technical requirements. Leach testing was performed in order to establish that the pH requirement (≤11) set for the leachates was met. For comparison reasons also one conventionally used cement based grout material was included in the tests. Two kinds of lowpH grout cement mixes were tested; mixes with added blast furnace slag (4 mixes) or added silica (6 mixes). All the mixes were not completely tested according to the test plan, because for some mixes during leach testing factors detrimental to the long-term safety of a repository were observed, e.g. too high pH or leached sulphide, which is harmful for copper. Leach testing of the grout mixes was performed in a glove-box (N 2 atmosphere) in order to avoid the interference of atmospheric CO 2 on the alkaline leachates. Two simulated groundwater solutions, saline OL-SO and fresh ALL-MR, were used as leachates. Two leach tests were applied; equilibrium and diffusion tests. In the equilibrium test at each measuring point only a part of the leachate was exchanged, whereas in the diffusion test the entire leachate was exchanged. The pH value of each leachate sample was measured, but total alkalinity was determined only for some leachates. Na, K, Ca, Mg, Al, Fe, Si, SO 4 2- , S TOT , and Cl were analysed in the leach solutions collected in the diffusion test of four grout mixes chosen. Also the corresponding solid specimens were analysed (SEM, XRD, EPMA, MIP, TG) in Japan. A few grout pore fluid pH values were measured in Spain, as well. The simplified thermodynamic model calculations were successful in qualitatively reproducing the

  12. Swedish projects

    International Nuclear Information System (INIS)

    Thunell, J.

    1992-01-01

    A description is given of research activities, concerning heating systems, which were carried out in Sweden during 1991. The main subject areas dealt with under the gas technology group within the area of heating systems were catalytic combustion, polyethylene materials, and gas applications within the paper and pulp industries. A list is given of the titles of project reports published during 1991 and of those begun during that year. Under the Swedish Centre for Gas Technology (SGC), the main areas of research regarding gas applications were polyethylene materials, industrial applications and the reduction of pollutant emissions. A detailed list is given of research projects which were in progress or proposed by March 1992 under the heating system gas technology research group in Sweden. This list also presents the aims and descriptions of the methods, etc. (AB)

  13. Evaluation of alternative shaft-sinking techniques for high-level nuclear waste (HLW) deep geologic repositories. Final report (Task 3), June 1981-July 1982

    International Nuclear Information System (INIS)

    Gonano, L.; Findley, D.; Wildanger, W.; Gates, R.; Phillips, S.

    1983-03-01

    This report represents the results of Task 3 of US Nuclear Regulatory Commission (NRC) Contract, Technical Assistance for Repository Design. The purpose of the complete project is to provide NRC with technical assistance for the following reasons: To enable the focused, adequate review by NRC of aspects related to design and construction of an in situ test facility and final geologic repository, as presented in US Department of Energy (DOE) Site Characterization Reports (SRC), To ascertain that the DOE site characterization program will provide, as far as possible, all the information necessary to permit a review to be conducted by NRC of a license application for construction authorization. It is assumed that the Site Characterization Report and License Application will describe the exploratory shaft and concept designs for the repository shafts. This report provides a comparative evaluation of various shaft sinking techniques for production shafts for a repository. The primary comparative evaluation has been conducted for 14-ft internal diameter shafts developed in two composite media using four different methods of sinking/lining. The technical, cost and schedule comparisons draw a major distinction between shafts sunk blind and those which utilize bottom access. Based on the system of ranking introduced to grade the significant attributes of each method and the resulting design, it is concluded that for application to repository access, no one particular method of sinking exhibits a clear overall superiority. When a specific site is made available for a study of the most suitable shaft sinking methods, it will be necessary to establish actual geological conditions and technological capabilities and the comparisons presented herein reviewed accordingly

  14. Repository exploration

    International Nuclear Information System (INIS)

    Pentz, D.L.

    1984-01-01

    This paper discusses exploration objectives and requirements for a nuclear repository in the U.S.A. The importance of designing the exploration program to meet the system performance objectives is emphasized and some examples of the extent of exploration required before the License Application for Construction Authorization is granted are also discussed

  15. Probabilistic safety assessment for a generic deep geological repository for high-level waste and long-lived intermediate-level waste in clay

    International Nuclear Information System (INIS)

    Resele, G.; Holocher, J.; Mayer, G.; Hubschwerlen, N.; Niemeyer, M.; Beushausen, M.; Wollrath, J.

    2010-01-01

    Document available in extended abstract form only. In the selection procedure for the search of a final site location for the disposal of radioactive wastes, the comparison and evaluation of different potentially suitable repository systems in different types of host rocks will be an essential and crucial step. Since internationally accepted guidelines on how to perform such quantitative comparisons between repository systems with regard to their long-term safety behaviour are still lacking, in 2007 the German Federal Office for Radiation Protection launched the project 'VerSi' (Vergleichende Sicherheitsanalysen - Comparing Safety Assessments) that aims at the development of a methodology for the comparison of long-term safety assessments. A vital part of the VerSi project is the performance of long-term safety assessments for the comparison of two repository systems. The comparison focuses on a future repository for heat-generating, i.e. high-level and long-lived intermediate-level radioactive wastes in Germany. Rock salt is considered as a potential host rock for such a repository, and one repository system in VerSi is defined similarly to the potential site located in the Gorleben salt dome. Another suitable host rock formation may be clay. A generic location within the lower Cretaceous clays in Northern Germany is therefore chosen for the comparison of safety assessments within the VerSi project. The long-term safety assessment of a repository system for heat-generating radioactive waste at the generic clay location comprises different steps, amongst others: - Identifying the relevant processes in the near-field, in the geosphere and in the biosphere which are relevant for the long-term safety behaviour. - Development of a safety concept for the repository system. - Deduction of scenarios of the long-term evolution of the repository system. - Definition of statistic weights, i. e. the likelihood of occurrence of the scenarios. - Performance of a

  16. In-situ test programs related to design and construction of high-level nuclear waste (HLW) deep geologic repositories. Final report (Task 2), June 1981-November 1982

    International Nuclear Information System (INIS)

    Roberds, W.; Bauhof, F.; Gonano, L.

    1983-03-01

    The media and sites considered include (1) basalt at Hanford, Washington; (2) tuff at Yucca Mountain, Nevada Test Site; (3) domal salt at specific Gulf Coast sites; (4) bedded salt at an unspecified site; and (5) granite at an unspecified site. A licensing perspective is outlined and a defensible rationale developed and utilized for the test selection process. This rationale essentially consists of: establishing the information needs for construction authorization; assessing the relevant capabilities of available tests; and matching the capabilities of specific tests to the perceived information needs. The information needs at any time consist of the additional information (if any) needed in order to predict satisfactory repository system performance with the required level of confidence, and thus are a function of: the significance of the repository engineered components and site characteristics to system performance; the currently available information, which may be supplemented with time; and the acceptable level of confidence in satisfactory performance for each licensing step. Determination of the acceptable levels of confidence and the significance of repository system components is outside the scope of this report. Suitable assumptions have thus been made regarding the development of information needs for construction authorization by the time of initial site submittals. Tests which are available and respond to the perceived media/site specific information needs, either by simulation or assessment of site characteristics, are identified and their capabilities assessed. Specific in situ tests are investigated and described in detail. Research and development which might be effective in improving test capabilities have been recommended

  17. Swedish encapsulation station review

    International Nuclear Information System (INIS)

    Andersson, Sven Olof; Brunzell, P.; Heibel, R.; McCarthy, J.; Pennington, C.; Rusch, C.; Varley, G.

    1998-06-01

    In the Encapsulation Station (ES) Review performed by NAC International, a number of different areas have been studied. The main objectives with the review have been to: Perform an independent review of the cost estimates for the ES presented in SKB's document 'Plan 1996'. This has been made through comparisons between the ES and BNFL's Waste Encapsulation Plant (WEP) at Sellafield as well as with the CLAB facility. Review the location of the ES (at the CLAB site or at the final repository) and its interaction with other parts of the Swedish system for spent fuel management. Review the logistics and plant capacity of the ES. Identify important safety aspects of the ES as a basis for future licensing activities. Based on NAC International's experience of casks for transport and storage of spent fuel, review the basic design of the copper/steel canister and the transport cask. This review insides design, manufacturing, handling and licensing aspects. Perform an overall comparison between the ES project and the CLAB project with the objective to identify major project risks and discuss their mitigation

  18. Swedish encapsulation station review

    Energy Technology Data Exchange (ETDEWEB)

    Andersson, Sven Olof; Brunzell, P.; Heibel, R.; McCarthy, J.; Pennington, C.; Rusch, C.; Varley, G. [NAC International, Zuerich (Switzerland)

    1998-06-01

    In the Encapsulation Station (ES) Review performed by NAC International, a number of different areas have been studied. The main objectives with the review have been to: Perform an independent review of the cost estimates for the ES presented in SKB`s document `Plan 1996`. This has been made through comparisons between the ES and BNFL`s Waste Encapsulation Plant (WEP) at Sellafield as well as with the CLAB facility. Review the location of the ES (at the CLAB site or at the final repository) and its interaction with other parts of the Swedish system for spent fuel management. Review the logistics and plant capacity of the ES. Identify important safety aspects of the ES as a basis for future licensing activities. Based on NAC International`s experience of casks for transport and storage of spent fuel, review the basic design of the copper/steel canister and the transport cask. This review insides design, manufacturing, handling and licensing aspects. Perform an overall comparison between the ES project and the CLAB project with the objective to identify major project risks and discuss their mitigation 19 refs, 9 figs, 35 tabs

  19. Education for the nuclear power industry: Swedish perspective

    International Nuclear Information System (INIS)

    Blomgren, J.

    2005-01-01

    In the Swedish nuclear power industry staff, very few newly employed have a deep education in reactor technology. To remedy this, a joint education company, Nuclear Training and Safety Center (KSU), has been formed. To ensure that nuclear competence will be available also in a long-term perspective, the Swedish nuclear power industry and the Swedish Nuclear Power Inspectorate (SKI) have formed a joint center for support of universities, the Swedish Nuclear Technology Center (SKC). The activities of these organisations, their links to universities, and their impact on the competence development for the nuclear power industry will be outlined. (author)

  20. Cigeo. The French deep geological repository for radioactive waste. Excavation techniques and technologies tested in underground laboratory and forecasted for the future construction of the project

    International Nuclear Information System (INIS)

    Chauvet, Francois; Bosgiraud, Jean-Michel

    2015-01-01

    Cigeo is the French project for the repository of the high activity and intermediate long-lived radioactive waste. It will be situated at a depth of 500 m, In a clayish rock formation. An underground laboratory was built in the year 2000 and numerous tests are performed since 15 years, in order to know in detail the behavior of the rock and its ability to confine radioactive elements. In addition, this underground laboratory has brought and will continue to bring many lessons on the excavation methods to be chosen for the construction of Cigeo.

  1. Evaluation of behaviour and Safety in a geologic deep repository; Evaluacion del comportamiento y de la seguridad de un almacenamiento geologico profundo en granito

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1997-07-01

    This report presents a comprehensive description of the post-closure radiological safety assessment of a repository for the spent fuel arisings resulting from the Spanish nuclear program. This Safety Assessment constitutes a first step within a systematical process that will permit, thorough successive approximations, to predict the performance of the different barriers of the disposal system, and its capability to comply with the assigned safety functions and with the established safety criteria. The primary bases for this Safety Assessment are the following: The disposal concept considers the storage of the fuel assemblies in carbon steel canisters of 10 cm of thickness, emplaced horizontally in galleries excavated in granite of 2,4 m of diameter and 500 m of length, using a bentonite thickness of 75 cm around canisters as buffer material. The repository is located in a granitic site defined with available data about surface characteristics of Spanish granites. The exercise uses a probabilistic approximation in order to cope with the uncertainties associated with the different imputs parameters. (Author)

  2. TURVA-2012 safety case for licensing a spent fuel repository at Olkiluoto, Finland

    International Nuclear Information System (INIS)

    Vira, Juhani; Snellman, Margit

    2014-01-01

    In 2001, the Finnish Parliament endorsed a decision-in-principle (DiP) whereby the spent nuclear fuel produced by the operating nuclear reactors at Olkiluoto and Loviisa will be disposed of in a geological repository at Olkiluoto, on the south-western coast of Finland. Subsequently, additional DiPs were issued allowing the extension of the repository to accommodate spent nuclear fuel from additional reactors that are under construction or in planning at Olkiluoto, which means a total of 9 000 tU of spent nuclear fuel to be disposed of. In accordance with the decision of the Ministry of Trade and Industry (KTM) in 2003, Posiva submitted an application for a license to construct a disposal facility at Olkiluoto in 2012, consisting of an encapsulation facility and an underground deep geological repository. The application included a Preliminary Safety Analysis Report (PSAR) and a long-term safety case, TURVA-2012. Assuming a positive outcome of the current licensing review, the next step would be the Final Safety Analysis Report (FSAR) in support of an operational licence application around 2020. The disposal method is based on the same KBS-3 concept that the Swedish SKB has used as basis for their license application in 2010. Accordingly, the spent nuclear fuel will be encapsulated in water- and gas-tight copper canisters equipped with a load-bearing insert and emplaced in a deep geological repository constructed in the bedrock. The canisters will be surrounded by a swelling clay buffer material that isolates them from the bedrock. The deposition tunnels and the central tunnels and the other underground openings will be backfilled with materials of low permeability. The repository will be at a depth of about 400-450 m below ground. The primary role of the bedrock is to provide sufficiently stable conditions for the engineered barrier system and to make inadvertent human intrusion unlikely. In case of EBS failure, the bedrock shall also retain and retard the possible

  3. SR 97 - Waste, repository design and sites. Background report to SR 97 SKB

    International Nuclear Information System (INIS)

    1999-10-01

    SR 97 is a comprehensive analysis of long-term safety of a deep repository for spent nuclear fuel. The repository is assumed to be designed according to the KBS-3 method. Assessments are performed in SR 97 for three fictitious sites: Aberg, Beberg and Ceberg. One premise is that data used for assessment of the fictitious sites are to be taken from sites that have previously been investigated. The spent nuclear fuel is enclosed in copper canisters with an insert of cast iron. The canisters are emplaced in bored holes in the floor of the deposition tunnels. Around each canister, bentonite blocks are stacked which, after absorbing water and swelling, will isolate the canister from groundwater, hold the canister in place and retard transport of radionuclides from the canister to the surrounding rock. The spent nuclear fuel will emit heat for a long time, due to the decay heat. The maximum permissible temperature on the canister surface has been chosen at 100 deg C. The spacing between the deposition holes and between the deposition tunnels is adjusted site-specifically to meet this requirement. The thermal properties of the rock and the buffer material are of importance for how closely the deposition holes and tunnels can be spaced. After deposition, the deposition tunnels are backfilled with a mixture of bentonite and crushed rock. SR 97 examines above all the consequences of various scenarios and the handling of various types of uncertainties. The different repository sites illustrate normal properties for Swedish bedrock which are of importance for safety. To facilitate the work, the repositories on the three sites are configured as similarly as possible, which means for example that they are located at roughly the same depth and are fitted into the bedrock in a relatively similar fashion. Apart from the siting of a repository for spent nuclear fuel, the site may need to house a separate repository for other long-lived waste. This possibility has been considered in

  4. SR 97 - Waste, repository design and sites. Background report to SR 97 SKB

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1999-10-01

    SR 97 is a comprehensive analysis of long-term safety of a deep repository for spent nuclear fuel. The repository is assumed to be designed according to the KBS-3 method. Assessments are performed in SR 97 for three fictitious sites: Aberg, Beberg and Ceberg. One premise is that data used for assessment of the fictitious sites are to be taken from sites that have previously been investigated. The spent nuclear fuel is enclosed in copper canisters with an insert of cast iron. The canisters are emplaced in bored holes in the floor of the deposition tunnels. Around each canister, bentonite blocks are stacked which, after absorbing water and swelling, will isolate the canister from groundwater, hold the canister in place and retard transport of radionuclides from the canister to the surrounding rock. The spent nuclear fuel will emit heat fora long time, due to the decay heat. The maximum permissible temperature on the canister surface has been chosen at 100 deg C. The spacing between the deposition holes and between the deposition tunnels is adjusted site-specifically to meet this requirement. The thermal properties of the rock and the buffer material are of importance for how closely the deposition holes and tunnels can be spaced. After deposition, the deposition tunnels are backfilled with a mixture of bentonite and crushed rock. SR 97 examines above all the consequences of various scenarios and the handling of various types of uncertainties. The different repository sites illustrate normal properties for Swedish bedrock which are of importance for safety. To facilitate the work, the repositories on the three sites are configured as similarly as possible, which means for example that they are located at roughly the same depth and are fitted into the bedrock in a relatively similar fashion. Apart from the siting of a repository for spent nuclear fuel, the site may need to house a separate repository for other long-lived waste. This possibility has been considered in

  5. Development of SKI's Regulatory Approach to the Siting of a Spent Nuclear Fuel Repository

    International Nuclear Information System (INIS)

    Westerlind, Magnus

    2003-01-01

    Since the beginning of the 1990s the Swedish Nuclear Fuel and Waste Management Co., SKB, is actively working with the siting of a spent nuclear fuel repository. Feasibility studies have been completed in a total of eight municipalities, and in December 2000 three municipalities (Oskarshamn, Tierp and Oesthammar) were proposed for further investigations. These site investigations include surface based site characterisation from deep bore holes but also further studies of infrastructure, land use, transportation etc. SKB's proposal was reviewed by SKI and about 60 other organisations, including municipalities, NGOs, government agencies etc. during the winter/spring 2000/2001. In June 2001 SKI reported the review findings to the Government. In parallel with SKI also the Swedish Council for Nuclear Waste (KASAM) reviewed SKB's proposal and reported to the Government. In its decision in November 2001 the Government supported SKB's proposal to continue with site investigations. Based on SKB's material, the reviews and the Government's decision the municipalities of Oesthammar and Oskarshamn have agreed to site investigations while Tierp have decided no to continue. The site investigations in Oesthammar and Oskarshamn started during 2002. The siting process has meant that several new actors have been engaged in nuclear waste management in general and disposal of spent nuclear fuel in particular. This has meant that 'old' actors, particularly SKB, the regulators (the Swedish Nuclear Power Inspectorate, SKI, and the Swedish Radiation Protection Authority, SSI) have had to evaluate, develop and clarify their roles and strategies for dialogue. This paper presents reflections on the impacts on some of SKI's regulatory activities

  6. Factors affecting microbial activity in compacted clay-based sealing materials proposed for use in a deep geologic repository for used nuclear fuel

    International Nuclear Information System (INIS)

    Stroes-Gascoyne, S.; Hamon, C.J.; Dixon, D.A.; Kjartanson, B.K.

    2006-01-01

    Microbial activity in clay-based barriers immediately adjacent to metal used-fuel containers in a repository could affect the longevity of such containers. The current emphasis is, therefore, on reducing or minimizing microbial activity in such clay-based barriers through material composition design. Factors affecting microbial activity in clay-based materials were studied in large-scale and smaller-scale experiments. Results suggested that keeping water activity (a w ) values below ∼0.95 may minimize microbial activity in clay-based barrier materials. A considerably higher effective montmorillonite dry density (EMDD), which partially controls a w , is achievable for 100% bentonite than for previously proposed reference buffer materials, which contain only 50% bentonite. (author)

  7. Planning for investigation and evaluation of potential repository sites in Sweden

    International Nuclear Information System (INIS)

    Almen, K.E.; Stroem, A.

    1998-01-01

    The present stage of siting of the Swedish Deep Repository for spent nuclear fuel involves general siting studies on national and regional scales and feasibility studies on a municipal scale. Based on these studies, two areas will be selected for surface-based site investigations. The geoscientific site information will be used in the site evaluation process, in which performance and safety assessments and design studies are the major activities, in combination with geoscientific characterization. The safety report and EIA document from the site investigation stage will be the most important documents in the application for the siting permit and the permit to construct the deep repository. Detailed characterization will then verify the suitability of the selected site. The programme for geoscientific site investigations is based on experience from more than 20 years of field studies in several SKB projects, such as the Study Site Investigations , the Stripa Project, and the Aespoe Hard Rock Laboratory. The strategies and methodologies developed, implemented and verified within the Aespoe HRL are a very important source of information and know-how for the development of the site investigation programme. The investigations will produce geoscientific models that include all information needed to analyze the long-term safety of a deep repository located in and adapted to the geological conditions of the rock. The type of geoscientific information needed for performance and safety assessment, layout and design, environmental studies and for fundamental geoscientific understanding has been specified and compiled in a 'parameter' report. The general strategy is that performance assessment, layout and design studies will be conducted in parallel with the geoscientific investigations. Information will be transferred at logical occasions, when decisions have to be taken and when feedback is desirable for new investigation steps. The role of the geoscientific evaluation is to

  8. Learning Object Repositories

    Science.gov (United States)

    Lehman, Rosemary

    2007-01-01

    This chapter looks at the development and nature of learning objects, meta-tagging standards and taxonomies, learning object repositories, learning object repository characteristics, and types of learning object repositories, with type examples. (Contains 1 table.)

  9. Site descriptive modelling during characterization for a geological repository for nuclear waste in Sweden

    International Nuclear Information System (INIS)

    Stroem, A.; Andersson, J.; Skagius, K.; Winberg, A.

    2008-01-01

    The Swedish programme for geological disposal of spent nuclear fuel is approaching major milestones in the form of permit applications for an encapsulation plant and a deep geologic repository. This paper presents an overview of the bedrock and surface modelling work that comprises a major part of the on-going site characterization in Sweden and that results in syntheses of the sites, called site descriptions. The site description incorporates descriptive models of the site and its regional setting, including the current state of the geosphere and the biosphere as well as natural processes affecting long-term evolution. The site description is intended to serve the needs of both repository engineering with respect to layout and construction, and safety assessment, with respect to long-term performance. The development of site-descriptive models involves a multi-disciplinary interpretation of geology, rock mechanics, thermal properties, hydrogeology, hydrogeochemistry, transport properties and ecosystems using input in the form of available data for the surface and from deep boreholes

  10. Final disposal of high-level nuclear waste in very deep boreholes. An evaluation based on recent research of bedrock conditions at great depths; Slutfoervaring av hoegaktivt kaernavfall i djupa borrhaal. En utvaerdering baserad paa senare aars forskning om berggrunden paa stora djup

    Energy Technology Data Exchange (ETDEWEB)

    Aahaell, Karl-Inge [Karlstad Univ. (Sweden)

    2007-01-15

    This report evaluates the feasibility of very deep borehole disposal of high-level nuclear waste, e.g., spent nuclear fuel, in the light of recent technological developments and research on the characteristics of bedrock at extreme depths. The evaluation finds that new knowledge in the field of hydrogeology and technical advances in drilling technology have advanced the possibility of using very deep boreholes (3-5 km) for disposal of the Swedish nuclear waste. Decisive factors are (1) that the repository can be located in stable bedrock at a level where the groundwater is isolated from the biosphere, and (2) that the waste can be deposited and the boreholes permanently sealed without causing long-term disturbances in the density-stratification of the groundwater that surrounds the repository. Very deep borehole disposal might offer important advantage compared to the relatively more shallow KBS approach that is presently planned to be used by the Swedish nuclear industry in Sweden, in that it has the potential of being more robust. The reason for this is that very deep borehole disposal appears to permit emplacement of the waste at depths where the entire repository zone would be surrounded by stable, density-stratified groundwater having no contact with the surface, whereas a KBS-3 repository would be surrounded by upwardly mobile groundwater. This hydro-geological difference is a major safety factor, which is particularly apparent in all scenarios that envisage leakage of radioactive substances. Another advantage of a repository at a depth of 3 to 5 km is that it is less vulnerable to impacts from expected events (e.g., changes in groundwater conditions during future ice ages) as well as undesired events (e.g. such as terrorist actions, technical malfunction and major local earthquakes). Decisive for the feasibility of a repository based on the very deep borehole concept is, however, the ability to emplace the waste without failures. In order to achieve this

  11. Collaborative repositories

    DEFF Research Database (Denmark)

    Pilegaard, Morten

    2009-01-01

    Textual and communicative competence lies at the heart of the skills of a professional linguistic mediator in general. Such skills are particularly important in specialized writing, which requires deep conceptual and contextual knowledge. One of the main objectives of the activities undertaken at...

  12. 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)

  13. Preservation of Records, Knowledge and Memory across Generations (RK and M). A Literature Survey on Markers and Memory Preservation for Deep Geological Repositories

    International Nuclear Information System (INIS)

    Buser, Marcos

    2013-01-01

    This study is an English translation and slight update of a previous study originally commissioned by the Swiss Federal Office of Energy between 2008 and 2010. The intention was to investigate the 'state of the art' on marking with a view to learning lessons for geological repositories. This is an edited and slightly updated English translation, published by the NEA as part of the RWMC project 'The Preservation of Records, Knowledge and Memory (RK and M) across Generations'. The work is conceived as a literature study. It considers over 150 texts, published between 1928 and 2013. Texts published between the 1990 and 2010 form a majority, making the 1990's and 2000's the dominant era. The texts include technical reports, journal articles, conference proceedings, implementation plans, national regulations, and full-length books. Some publications are specifically about the concept, implementation and requirements for Markers. Others consider the geological disposal of radioactive from other points of view - for example, archiving, or intrusion scenarios. Others are publications on history or futurism, including histories of genocide and language, and the possibilities of communication far into the future. Authors of the texts include academies, international organisations, consultants commissioned by national organisations, regulators, implementers, and protest groups. It should be recognised that, whilst care has been taken to provide a wide and representative study, the concept of 'marking' a geological repository was first established in the USA. The available literature on Markers is still dominated by work carried out in the USA in the 1980's, 1990's and 2000's. The conclusions and points of view surveyed are therefore weighted towards this body of work. The study brings together the knowledge and experience from the field of marking and archiving from the last few decades and provides an overview of the present status of discussions on the topic. It is an

  14. Groundwater chemistry around a repository for spent nuclear fuel over a glacial cycle. Evaluation for SR-Can

    International Nuclear Information System (INIS)

    Auque, L.F.; Gimeno, M.J.; Gomez, J.B.; Puigdomenech, I.; Smellie, J.; Tullborg, E.L.

    2007-12-01

    The chemical composition of groundwater in the rock volume surrounding a spent nuclear fuel repository is of importance to many factors that affect repository performance. The geochemical characteristics of present-day Swedish groundwater systems are governed by successive mixing events of several waters during the post-glacial evolution of the sites. The expected development of groundwaters at two Swedish sites - Forsmark and Laxemar - during a glacial cycle has been evaluated within the SR-Can project, and the results are presented in this report. For the temperate period following repository closure, an approach is proposed here to investigate the spatial and temporal evolution of groundwater geochemistry by coupling hydrogeological and geochemical models in a sequential way. The procedure combines hydrogeological results obtained with CONNECTFLOW within the SR-Can project with a mixing and reaction path simulation using PHREEQC. The hydrological results contain mixing proportions of four component waters (a deep brine, glacial meltwater, marine water, and meteoric infiltration) at each time step and at every node of the D regional model domain. In this work the mixing fractions are fed into PHREEQC using software developed to build formatted input files and to extract the information from output files for subsequent plotting and analysis. The geochemical calculations included both chemical mixing and equilibrium reactions with selected minerals: calcite, chalcedony and an Fe(III) oxy-hydroxide. Results for the Forsmark and Laxemar sites are graphically presented as histograms and box-and-whisker plots. Cross sections, where each node is colour-coded with respect to an important variable (pH, Eh or concentrations of main elements), are used to visualize the future evolution of the site. Sensitivity analyses are made to evaluate the effects of the different reactions and/or assumptions. The results reflect the progressive inflow of meteoric waters into the sites

  15. Groundwater chemistry around a repository for spent nuclear fuel over a glacial cycle. Evaluation for SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Auque, L.F.; Gimeno, M.J.; Gomez, J.B. [University of Zaragoza (Spain); Puigdomenech, I. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Smellie, J. [Conterra AB, Uppsala (Sweden); Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    2007-12-15

    The chemical composition of groundwater in the rock volume surrounding a spent nuclear fuel repository is of importance to many factors that affect repository performance. The geochemical characteristics of present-day Swedish groundwater systems are governed by successive mixing events of several waters during the post-glacial evolution of the sites. The expected development of groundwaters at two Swedish sites - Forsmark and Laxemar - during a glacial cycle has been evaluated within the SR-Can project, and the results are presented in this report. For the temperate period following repository closure, an approach is proposed here to investigate the spatial and temporal evolution of groundwater geochemistry by coupling hydrogeological and geochemical models in a sequential way. The procedure combines hydrogeological results obtained with CONNECTFLOW within the SR-Can project with a mixing and reaction path simulation using PHREEQC. The hydrological results contain mixing proportions of four component waters (a deep brine, glacial meltwater, marine water, and meteoric infiltration) at each time step and at every node of the D regional model domain. In this work the mixing fractions are fed into PHREEQC using software developed to build formatted input files and to extract the information from output files for subsequent plotting and analysis. The geochemical calculations included both chemical mixing and equilibrium reactions with selected minerals: calcite, chalcedony and an Fe(III) oxy-hydroxide. Results for the Forsmark and Laxemar sites are graphically presented as histograms and box-and-whisker plots. Cross sections, where each node is colour-coded with respect to an important variable (pH, Eh or concentrations of main elements), are used to visualize the future evolution of the site. Sensitivity analyses are made to evaluate the effects of the different reactions and/or assumptions. The results reflect the progressive inflow of meteoric waters into the sites

  16. The Swedish programme for radioactive waste management

    International Nuclear Information System (INIS)

    Bjurstroem, S.; Forsstroem, H.

    1986-10-01

    The following systems and facilities are currently in operation and under implementation: a sea transportation system for all kinds of nuclear waste, a central facility for interim storage of spent fuel (CLAB) and a central underground repository for final disposal of low and medium level reactor waste (SFR). For the remaining steps - final disposal of highly active and longlived radioactive residues - a concept, based on encapsulation of the fuel elements in copper canisters and final storage of the canisters in a repository situated 500 m down in crystalline rock (KBS-3), has been developed and approved by the government in accordance with the Swedish nuclear legislation. Although a feasible method for final disposal of the highly active residues has been shown, the Swedish legislation requires that research be carried out to reach the best possible base for the final decision around the year 2000. In parallel with this a geological investigation programme is carried out to find a suitable site for a final repository. The final site selection is foreseen at the end of the 1990's. All costs for the management of radioactive waste from the nuclear power plants are carried by a fee determined annually. The fee is 0.019 SEK/kWh for 1986

  17. 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

  18. Investigations of the populations of introduced and resident micro-organisms in deep repositories and their effects on containment of radioactive wastes

    International Nuclear Information System (INIS)

    West, J.M.; Christofi, N.; Philip, J.C.; Arme, S.C.

    1985-04-01

    The potential role of microbes in the containment of radioactive waste has been described in several papers but can be briefly summarised as: (1) near field effects ((a) biodeterioration of repository structural materials; (b) mobilisation of waste); (2) far field effects ((a) change in ground water chemistry eg pH, Eh; (b) changes in radionuclide sorption characteristics (speciation, retardation)). The present study has sought to establish the presence of microbes in relevant formations, determine their potential role in disposal and make preliminary investigations on their ability to tolerate extreme environmental conditions and change migration characteristics. As the ultimate goal of this work is to try and model the effect of microorganisms on containment and radionuclide migration, an attempt to define the geochemical constraints on their growth has been attempted within the present study. Several sites of relevance to radioactive waste disposal have been sampled for microbiological content according to a protocol defined in pilot studies. These sites have been in Britain and in mainland Europe. Results have shown that the microbiota of each site is unique but that certain groups are of more importance eg sulphate reducing bacteria, sulphur oxidisers, and that their presence in future sampling should be ascertained as a first priority. (author)

  19. Fundamentals of the NEA Thermochemical Database and its influence over national nuclear programs on the performance assessment of deep geological repositories.

    Science.gov (United States)

    Ragoussi, Maria-Eleni; Costa, Davide

    2017-03-14

    For the last 30 years, the NEA Thermochemical Database (TDB) Project (www.oecd-nea.org/dbtdb/) has been developing a chemical thermodynamic database for elements relevant to the safety of radioactive waste repositories, providing data that are vital to support the geochemical modeling of such systems. The recommended data are selected on the basis of strict review procedures and are characterized by their consistency. The results of these efforts are freely available, and have become an international point of reference in the field. As a result, a number of important national initiatives with regard to waste management programs have used the NEA TDB as their basis, both in terms of recommended data and guidelines. In this article we describe the fundamentals and achievements of the project together with the characteristics of some databases developed in national nuclear waste disposal programs that have been influenced by the NEA TDB. We also give some insights on how this work could be seen as an approach to be used in broader areas of environmental interest. Copyright © 2017 Elsevier Ltd. All rights reserved.

  20. Swedish Disarmament Policy

    OpenAIRE

    2012-01-01

    NPIHP Partners Host Conference on Swedish Disarmament Policy Dec 05, 2012 The Nuclear Proliferation International History Project is pleased to announce a conference on Swedish nuclear disarmament policy, organized and hosted by Stockholm University on 26 november 2012. Organized by Stockholm University Professor Thomas Jonter, Emma Rosengren, Goran Rydeberg, and Stellan Andersson under the aegis of the Swedish Disarmament Resaerch Project, the conference featured keynote addresses by Hans Bl...

  1. Monte-Carlo based comparison of the personal dose for emplacement scenarios of spent nuclear fuel casks in generic deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Hector Sauri; Becker, Franz; Metz, Volker [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Pang, Bo [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Shenzhen Univ. (China). College of Physics and Energy

    2017-06-15

    In the operational phase of a deep geological disposal facility for high-level nuclear waste, the radiation field in the vicinity of a waste cask is influenced by the backscattered radiation of the surrounding walls of the emplacement drift. For a comparison of disposal of spent nuclear fuel in various host rocks, it is of interest to investigate the influence of the surrounding materials on the radiation field and the personal radiation exposure. In this generic study individual dosimetry of personnel involved in emplacement of casks with spent nuclear fuel in drifts in rock salt and in a clay formation was modelled.

  2. 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)

  3. Attitudes and opposition in siting a high level nuclear waste repository

    International Nuclear Information System (INIS)

    Sjoeberg, L.; Viklund, M.; Truedsson, J.

    1998-09-01

    In Sweden, the Swedish Nuclear Fuel and Waste Management Company (SKB) handles all issues concerning nuclear waste, including the siting process, in which the final outcome is intended to be a repository for high level nuclear waste placed deep down in bedrock. The main objective of the siting process is to find a host community fulfilling two important conditions: the safety demands have been met and agreements with the municipality can be accomplished. Only in such municipalities, so-called feasibility studies will be conducted. After conducting general studies in the whole country, SKB, in October 1992, sent letters with information about the intended feasibility studies to all Swedish municipalities. As a result, feasibility studies are or have been considered - and in some cases also been conducted - in eleven Swedish municipalities up until 1998. These are the municipalities where the attitudes and opposition towards a feasibility study, and possibly a final repository, are studied. The discussion can be divided into three main parts: Management of the siting process; Inherent 'chaotic' processes and/or factors and risk perception. It is argued that two important problems could have been avoided at least partly: The citizens in many municipalities were uncertain of the relationship between a feasibility study and a final repository, and in many municipalities the citizens were afraid that the Government could overrule the municipal veto. Because of these fears, a common argument among the opponents of a feasibility study was: 'to be sure of not receiving a final repository, we say no to a feasibility study'. Some inherent factors, more or less prevalent in the municipalities as well as in society in general, may also partly explain the outcome of the siting process. The municipalities in which the debate has been heated, and where public support has been more difficult to reach, share some common characteristics. Esp. in the municipalities in the north of

  4. Attitudes and opposition in siting a high level nuclear waste repository

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, L.; Viklund, M.; Truedsson, J

    1998-09-01

    In Sweden, the Swedish Nuclear Fuel and Waste Management Company (SKB) handles all issues concerning nuclear waste, including the siting process, in which the final outcome is intended to be a repository for high level nuclear waste placed deep down in bedrock. The main objective of the siting process is to find a host community fulfilling two important conditions: the safety demands have been met and agreements with the municipality can be accomplished. Only in such municipalities, so-called feasibility studies will be conducted. After conducting general studies in the whole country, SKB, in October 1992, sent letters with information about the intended feasibility studies to all Swedish municipalities. As a result, feasibility studies are or have been considered - and in some cases also been conducted - in eleven Swedish municipalities up until 1998. These are the municipalities where the attitudes and opposition towards a feasibility study, and possibly a final repository, are studied. The discussion can be divided into three main parts: Management of the siting process; Inherent `chaotic` processes and/or factors and risk perception. It is argued that two important problems could have been avoided at least partly: The citizens in many municipalities were uncertain of the relationship between a feasibility study and a final repository, and in many municipalities the citizens were afraid that the Government could overrule the municipal veto. Because of these fears, a common argument among the opponents of a feasibility study was: `to be sure of not receiving a final repository, we say no to a feasibility study`. Some inherent factors, more or less prevalent in the municipalities as well as in society in general, may also partly explain the outcome of the siting process. The municipalities in which the debate has been heated, and where public support has been more difficult to reach, share some common characteristics. Esp. in the municipalities in the north of

  5. GENIUS & the Swedish Fast Reactor programme

    International Nuclear Information System (INIS)

    Wallenius, Janne

    2012-01-01

    Concluding remarks: Sweden’s growing fast reactor programme focuses on LFR technology, but we also participate in ASTRID. • An innovative facility for UN fabrication, an LBE thermal hydraulics loop and a lead corrosion facility are operational. • A plutonium fuel fabrication lab is is under installation (this week!) • The government is assessing the construction of ELECTRA-FCC, a centre for Gen IV-system R&D, at a tentative cost of ~ 140±20 M€. • Location: Oskarshamn (adjacent to intermediate repository) • Date of criticality: 2023 (best case) • Swedish participation in IAEA TWG-FR should intensify

  6. Modelling saline intrusion for repository performance assessment

    International Nuclear Information System (INIS)

    Jackson, C.P.

    1989-04-01

    UK Nirex Ltd are currently considering the possibility of disposal of radioactive waste by burial in deep underground repositories. The natural pathway for radionuclides from such a repository to return to Man's immediate environment (the biosphere) is via groundwater. Thus analyses of the groundwater flow in the neighbourhood of a possible repository, and consequent radionuclide transport form an important part of a performance assessment for a repository. Some of the areas in the UK that might be considered as possible locations for a repository are near the coast. If a repository is located in a coastal region seawater may intrude into the groundwater flow system. As seawater is denser than fresh water buoyancy forces acting on the intruding saline water may have significant effects on the groundwater flow system, and consequently on the time for radionuclides to return to the biosphere. Further, the chemistry of the repository near-field may be strongly influenced by the salinity of the groundwater. It is therefore important for Nirex to have a capability for reliably modelling saline intrusion to an appropriate degree of accuracy in order to make performance assessments for a repository in a coastal region. This report describes work undertaken in the Nirex Research programme to provide such a capability. (author)

  7. Analysis of long-term geological and hydrogeological changes in the Swedish programme for final disposal of nuclear waste

    International Nuclear Information System (INIS)

    Ericsson, L.O.; Boulton, G.S.

    1996-01-01

    In assessing the safety of deep disposal of nuclear waste in crystalline rocks it is important establish whether recent or future changes in loading can lead to fracturing and block displacement which may change the hydrogeological setting of a repository. Furthermore, it is of vital importance to understand how future climate changes, especially future glaciations, will influence the groundwater flow around a deep repository. The Swedish programme comprises R and D activities which attempt to quantify probable impacts of earthquakes, glaciation and land uplift. The activities emphasize geodynamic processes in the Baltic Shield, post-glacial faulting and glacial impacts on hydrogeology and ground water chemistry. A time-dependent, thermo-mechanically coupled, three-dimensional model of the ice sheet behaviour in Scandinavia has been developed. The model is driven by changes in the elevation of the permanent snow line on its surface and by air temperature and predicts the behaviour of the ice sheet for an earth's surface of given form and mechanical properties. The ice sheet model reconstructs the ice sheet thickness, ice sheet temperature distribution, including basal temperature, basal meting pattern and velocity distribution. The model is coupled to a sub-glacial Dancian groundwater flow model which in turn provides boundary for evaluations of long-term hydrogeological evolution at specific sites. (authors). 22 refs., 3 figs

  8. SR-CAN - a safety assessment of a repository of spent nuclear fuel: canister performance and effects on the biosphere

    International Nuclear Information System (INIS)

    Kautsky, U.; Kumblad, L.

    2004-01-01

    During the next few years the Swedish Nuclear Fuel and Waste Management Co. (SKB) performs site investigations at two sites in Sweden for a future repository of spent nuclear fuel. Parallel an encapsulation plant is planned to encapsulate the spent fuel in copper canisters according to the KBS-3 method. The purpose of the SR-CAN safety assessment is to show the performance of the canister isolations at different sites for a repository at 500 meters depth in crystalline rock. Moreover, SR-CAN provides an example how the site specific safety assessment of a deep repository will be made in year 2006-2008. To be able to calculate dose and risk for humans and the environment, new assessment methods were developed for the biosphere. These methods were based on a system ecological approach and used knowledge from landscape ecology to provide an integrated approach with hydrology and geology considering the discharges in a watershed and calculating consequences in terrestrial and aquatic (freshwater and marine) ecosystems. A range of methods and tools were developed in GIS and Matlab/Simulink to be able to model and understand the important processes in the landscape today and during the next few thousands of years. In this paper, an overview of the program and the novel methods are presented, as well as some examples from performance calculations from a watershed in the Forsmark area considering effects on humans and ecosystems. (author)

  9. Establishment of advanced integration technology for site characterization of deep geological repository. Development of information synthesis and interpretation system. Annual report 2007

    International Nuclear Information System (INIS)

    Osawa, Hideaki; Umeki, Hiroyuki; Ota, Kunio; Maekawa, Keisuke; Kunimaru, Takanori; Niizato, Tadafumi; Asamori, Koichi; Yamanaka, Yoshiaki; Shigehiro, Michiko; Abe, Hironobu; Hama, Katsuhiro; Takeuchi, Shinji; Amano, Kenji; Saegusa, Hiromitsu; Matsukawa, Toshiyuki; Miyamoto, Tetsuo; Toyoda, Gakuji; Sawada, Atsushi; Shimada, Akiomi

    2008-11-01

    This project is planned as a five-year program aiming to develop an advanced integration technology for characterization of a site for radioactive waste geological disposal. It is carried out by the Geological Isolation Research and Development Directorate of Japan Atomic Energy Agency with the fund of Agency for Natural Resources and Energy of the Ministry of Economy, Trade and Industry. This report summarizes the outcome of the first year (FY 2007) activities of the project. The site characterization is a dynamic and complex process and needs close linkage with repository design and performance assessment (PA). A geosynthesis methodology has been developed for integrating site characterization information into design and PA, and applied for e.g. on-going JAEA's studies at two generic URLs at Mizunami and Horonobe. This methodology explicitly presents an information flow (often referred to as geosynthesis data flow diagram or data flow diagram, in short) from measurements by site investigation to generating data sets for design and PA. It is a useful tool for guiding the site characterization in a transparent and traceable manner. As site investigation proceeds and information being obtained on geological environments of the site increases, the site characterization plan is iteratively reviewed and modified reflecting the updated information. Such modification would also be needed when changes would occur on socio-political boundary conditions. In fact, the data flow diagrams for two generic URL projects have been revised several times so far due to the increase in the amount of information on geological environments and changes of societal conditions. An advanced technology aimed at in this project is therefore focused on developing flexible approach and tools, which is named as Information Synthesis and Interpretation System (ISIS), to support the stepwise 'optimization' of the site characterization plan. In FY 2007, a basic concept for ISIS has been developed

  10. The implications of soil acidification on a future HLW repository. Pt 2. Influence on deep granitic groundwater. The Klipperaas study site as test case

    International Nuclear Information System (INIS)

    Wersin, P.; Bruno, J.; Laaksoharju, M.

    1994-05-01

    The effect of acidification on deep groundwater is assessed with a geochemical box model based on the STEADYQL code. The application of the model to the Klipperaas study site shows a remarkable agreement between observed and predicted groundwater composition and offers an adequate description of the geochemical evolution of the aquifer. Proton fluxes are shown to be controlled mainly by calcite weathering and organic carbon degradation processes. The impact of increased acidification is evaluated on the basis of various test cases and by including the soil compartment in the model framework. The results indicate that calcite weathering will be increased by a factor of two to three as a result of increased acidification. Furthermore, the calculations suggest that, once the powerful carbonate buffer is depleted, the buffer capacity is provided mainly by anaerobic respiration and ion exchange processes. Further ongoing acidic loading would lead to neutralization of alkalinity fluxes leaving the system with a very low buffering capacity towards fluctuations in proton fluxes. Estimation of time scales of aquifer acidification was assessed under the focus of calcite depletion with aid of two acidification scenarios. These predict a time range of 12400 to 370000 years for calcite depletion to take place down to 500 meters depth. It is suggested from inherent model assumptions that these estimated time scales are conservative. 53 refs

  11. The implications of soil acidification on a future HLW repository. Pt 2. Influence on deep granitic groundwater. The Klipperaas study site as test case.

    Energy Technology Data Exchange (ETDEWEB)

    Wersin, P; Bruno, J [MBT Tecnologia Ambiental, Cerdanyola (Spain); Laaksoharju, M [Geopoint AB, Spaanga (Sweden)

    1994-05-01

    The effect of acidification on deep groundwater is assessed with a geochemical box model based on the STEADYQL code. The application of the model to the Klipperaas study site shows a remarkable agreement between observed and predicted groundwater composition and offers an adequate description of the geochemical evolution of the aquifer. Proton fluxes are shown to be controlled mainly by calcite weathering and organic carbon degradation processes. The impact of increased acidification is evaluated on the basis of various test cases and by including the soil compartment in the model framework. The results indicate that calcite weathering will be increased by a factor of two to three as a result of increased acidification. Furthermore, the calculations suggest that, once the powerful carbonate buffer is depleted, the buffer capacity is provided mainly by anaerobic respiration and ion exchange processes. Further ongoing acidic loading would lead to neutralization of alkalinity fluxes leaving the system with a very low buffering capacity towards fluctuations in proton fluxes. Estimation of time scales of aquifer acidification was assessed under the focus of calcite depletion with aid of two acidification scenarios. These predict a time range of 12400 to 370000 years for calcite depletion to take place down to 500 meters depth. It is suggested from inherent model assumptions that these estimated time scales are conservative. 53 refs.

  12. Geotechnical instrumentation for repository shafts

    International Nuclear Information System (INIS)

    Lentell, R.L.; Byrne, J.

    1993-01-01

    The US Congress passed the Nuclear Waste Policy Act in 1980, which required that three distinctly different geologic media be investigated as potential candidate sites for the permanent disposal of high-level nuclear waste. The three media that were selected for study were basalt (WA), salt (TX, LA, MS, UT), and tuff (NV). Preliminary Exploratory Shaft Facilities (ESF) designs were prepared for seven candidate salt sites, including bedded and domal salt environments. A bedded-salt site was selected in Deaf Smith County, TX for detailed site characterization studies and ESF Final Design. Although Congress terminated the Salt Repository Program in 1988, Final Design for the Deaf Smith ESF was completed, and much of the design rationale can be applied to subsequent deep repository shafts. This paper presents the rationale for the geotechnical instrumentation that was designed for construction and operational performance monitoring of the deep shafts of the in-situ test facility. The instrumentation design described herein can be used as a general framework in designing subsequent instrumentation programs for future high-level nuclear waste repository shafts

  13. Validation of a physically based catchment model for application in post-closure radiological safety assessments of deep geological repositories for solid radioactive wastes.

    Science.gov (United States)

    Thorne, M C; Degnan, P; Ewen, J; Parkin, G

    2000-12-01

    The physically based river catchment modelling system SHETRAN incorporates components representing water flow, sediment transport and radionuclide transport both in solution and bound to sediments. The system has been applied to simulate hypothetical future catchments in the context of post-closure radiological safety assessments of a potential site for a deep geological disposal facility for intermediate and certain low-level radioactive wastes at Sellafield, west Cumbria. In order to have confidence in the application of SHETRAN for this purpose, various blind validation studies have been undertaken. In earlier studies, the validation was undertaken against uncertainty bounds in model output predictions set by the modelling team on the basis of how well they expected the model to perform. However, validation can also be carried out with bounds set on the basis of how well the model is required to perform in order to constitute a useful assessment tool. Herein, such an assessment-based validation exercise is reported. This exercise related to a field plot experiment conducted at Calder Hollow, west Cumbria, in which the migration of strontium and lanthanum in subsurface Quaternary deposits was studied on a length scale of a few metres. Blind predictions of tracer migration were compared with experimental results using bounds set by a small group of assessment experts independent of the modelling team. Overall, the SHETRAN system performed well, failing only two out of seven of the imposed tests. Furthermore, of the five tests that were not failed, three were positively passed even when a pessimistic view was taken as to how measurement errors should be taken into account. It is concluded that the SHETRAN system, which is still being developed further, is a powerful tool for application in post-closure radiological safety assessments.

  14. Processing Relative Clause Extractions in Swedish

    OpenAIRE

    Tutunjian, Damon; Heinat, Fredrik; Klingvall, Eva; Wiklund, Anna-Lena

    2017-01-01

    Relative clauses are considered strong islands for extraction across languages. Swedish comprises a well-known exception, allegedly allowing extraction from relative clauses (RCE), raising the possibility that island constraints may be subject to “deep variation” between languages. One alternative is that such exceptions are only illusory and represent “surface variation” attributable to independently motivated syntactic properties. Yet, to date, no surface account has proven tenable for Swed...

  15. Swedish Government Minister at CERN

    CERN Document Server

    2008-01-01

    The Swedish Minister for Higher Education and Research recently visited CERN. The Swedish Minister was greeted by Swedish scientists working at CERN. Signing of the Swedish Computing Memorandum of Understanding. Pär Omling, Director-General of the Swedish Research Council (left), and Jos Engelen, CERN’s Chief Scientific Officer. Lars Leijonborg, the Swedish Minister for Higher Education and Research, was welcomed to CERN by Director-General Robert Aymar on 10 March. After an introduction to the Laboratory’s activities, the Minister was given guided tours of the control room, the ATLAS surface hall and experiment cavern and the adjoining LHC tunnel. Mr Leijonborg was then greeted by Swedish scientists and given an overview of the Swedish research programme at CERN. Five Swedish university groups are taking part in LHC research. Swedish universities are notably involved in the manufacture of parts for the sub-detectors of AT...

  16. A Strategy for Describing the Biosphere at Candidate Sites for Repositories of Nuclear Waste: Linking Ecosystem and Landscape Modeling

    International Nuclear Information System (INIS)

    Lindborg, Tobias; Loefgren, Anders; Soederbaeck, Bjoern; Kautsky, Ulrik; Lindborg, Regina; Bradshaw, Clare

    2006-01-01

    To provide information necessary for a license application for a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Co. has started site investigations at two sites in Sweden. In this paper, we present a strategy to integrate site-specific ecosystem data into spatially explicit models needed for safety assessment studies and the environmental impact assessment. The site-specific description of ecosystems is developed by building discipline-specific models from primary data and by identifying interactions and stocks and flows of matter among functional units at the sites. The conceptual model is a helpful initial tool for defining properties needed to quantify system processes, which may reveal new interfaces between disciplines, providing a variety of new opportunities to enhance the understanding of the linkages between ecosystem characteristics and the functional properties of landscapes. This type of integrated ecosystem-landscape characterization model has an important role in forming the implementation of a safety assessment for a deep repository

  17. Swedish Energy Research 2009

    Energy Technology Data Exchange (ETDEWEB)

    2009-07-01

    Swedish Energy Research 2009 provides a brief, easily accessible overview of the Swedish energy research programme. The aims of the programme are to create knowledge and skills, as needed in order to commercialise the results and contribute to development of the energy system. Much of the work is carried out through about 40 research programmes in six thematic areas: energy system analysis, the building as an energy system, the transport sector, energy-intensive industries, biomass in energy systems and the power system. Swedish Energy Research 2009 describes the overall direction of research, with examples of current research, and results to date within various thematic areas and highlights

  18. Process mining software repositories

    NARCIS (Netherlands)

    Poncin, W.; Serebrenik, A.; Brand, van den M.G.J.

    2011-01-01

    Software developers' activities are in general recorded in software repositories such as version control systems, bug trackers and mail archives. While abundant information is usually present in such repositories, successful information extraction is often challenged by the necessity to

  19. Breast Cancer Tissue Repository

    National Research Council Canada - National Science Library

    Iglehart, J

    1997-01-01

    The Breast Tissue Repository at Duke enters its fourth year of finding. The purpose of the Repository at Duke is to provide substantial quantities of frozen tissue for explorative molecular studies...

  20. On the role of anisotropy in the perturbation of Boom Clay by a deep disposal repository for high-level wastes

    International Nuclear Information System (INIS)

    Sillen, X.; Li, X.L.; Van Marcke, P.; Chen, G.; Bastiaens, W.

    2010-01-01

    Document available in extended abstract form only. All along the characterisation programme of the Boom Clay, a potential host rock for geological disposal of long-lived, heat-emitting radioactive waste, evidences of anisotropy of key thermo-hydro-mechanical (THM) properties have been collected through direct observations and laboratory measurements. In parallel, evidences of anisotropic THM behaviour of the clay massif were obtained during excavations and in-situ experiments in the underground research laboratory HADES at Mol. Careful analysis of the observations and simple modelling reveal the key role of the anisotropy of the material properties and, to a lesser extent, the in situ stresses in the development of a damaged zone around the galleries and the hydro-mechanical perturbation in the clay massif. As a consequence of the sedimentary deposition process, clay formations often exhibit visible bedding. This is the case for Boom Clay. Like other deep clays, Boom Clay also exhibits pronounced strain anisotropy under certain hydro-mechanical loading. Isotropic compression tests performed in the early nineties have shown that, for Boom Clay at a depth of about 225 m, the increments of deformation perpendicular to the bedding planes, i.e. vertical, are about two times larger than increments of deformation parallel to the bedding planes, i.e. horizontal. Moreover, it was observed that this mechanical anisotropy decreases progressively as the isotropic stress is increased. Drained heating tests under constant isotropic loading also evidenced anisotropic behaviour during thermo-consolidation. Like the mechanical properties, hydraulic and thermal properties of the Boom Clay also show anisotropy: lab and in situ measurements suggest that the horizontal hydraulic conductivity is about twice the vertical one while the ratio between horizontal and vertical thermal conductivities is about 1.4. The anisotropic THM behaviour of the Boom Clay was evidenced during excavations

  1. 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

  2. Processing Relative Clause Extractions in Swedish

    Directory of Open Access Journals (Sweden)

    Damon Tutunjian

    2017-12-01

    Full Text Available Relative clauses are considered strong islands for extraction across languages. Swedish comprises a well-known exception, allegedly allowing extraction from relative clauses (RCE, raising the possibility that island constraints may be subject to “deep variation” between languages. One alternative is that such exceptions are only illusory and represent “surface variation” attributable to independently motivated syntactic properties. Yet, to date, no surface account has proven tenable for Swedish RCEs. The present study uses eyetracking while reading to test whether the apparent acceptability of Swedish RCEs has any processing correlates at the point of filler integration compared to uncontroversial strong island violations. Experiment 1 tests RCE against licit that-clause extraction (TCE, illicit extraction from a non-restrictive relative clause (NRCE, and an intransitive control. For this, RCE was found to pattern similarly to TCE at the point of integration in early measures, but between TCE and NRCE in total durations. Experiment 2 uses RCE and extraction from a subject NP island (SRCE to test the hypothesis that only non-islands will show effects of implausible filler-verb dependencies. RCE showed sensitivity to the plausibility manipulation across measures at the first potential point of filler integration, whereas such effects were limited to late measures for SRCE. In addition, structural facilitation was seen across measures for RCE relative to SRCE. We propose that our results are compatible with RCEs being licit weak island extractions in Swedish, and that the overall picture speaks in favor of a surface rather than a deep variation approach to the lack of island effects in Swedish RCEs.

  3. Impact of cementitious materials decalcification on transfer properties: application to radioactive waste deep repository; Influence de la decalcification de materiaux cimentaires sur les proprietes de transfert: application au stockage profond de dechets radioactifs

    Energy Technology Data Exchange (ETDEWEB)

    Perlot, C

    2005-09-15

    Cementitious materials have been selected to compose the engineering barrier system (EBS) of the French radioactive waste deep repository, because of concrete physico-chemical properties: the hydrates of the cementitious matrix and the pH of the pore solution contribute to radionuclides retention; furthermore the compactness of these materials limits elements transport. The confinement capacity of the system has to be assessed while a period at least equivalent to waste activity (up to 100.000 years). His durability was sustained by the evolution of transfer properties in accordance with cementitious materials decalcification, alteration that expresses structure long-term behavior. Then, two degradation modes were carried out, taking into account the different physical and chemical solicitations imposed by the host formation. The first mode, a static one, was an accelerated decalcification test using nitrate ammonium solution. It replicates the EBS alteration dues to underground water. Degradation kinetic was estimated by the amount of calcium leached and the measurement of the calcium hydroxide dissolution front. To evaluate the decalcification impact, samples were characterized before and after degradation in term of microstructure (porosity, pores size distribution) and of transfer properties (diffusivity, gas and water permeability). The influence of cement nature (ordinary Portland cement, blended cement) and aggregates type (lime or siliceous) was observed: experiments were repeated on different mortars mixes. On this occasion, an essential reflection on this test metrology was led. The second mode, a dynamical degradation, was performed with an environmental permeameter. It recreates the EBS solicitations ensured during the re-saturation period, distinguished by the hydraulic pressure imposed by the geologic layer and the waste exothermicity. This apparatus, based on triaxial cell functioning, allows applying on samples pressure drop between 2 and 10 MPa and

  4. What requirements does the KBS-3 repository make on the host rock? Geoscientific suitability indicators and criteria for siting and site evaluation

    International Nuclear Information System (INIS)

    Andersson, Johan; Stroem, Anders; Svemar, Christer; Almen, Karl-Erik; Ericsson, Lars O.

    2000-04-01

    This report gives an account of what requirements are made on the rock, what conditions in the rock are advantageous and how the fulfilment of requirements and preferences is to be judged prior to the selection of sites for a site investigation and during a site investigation. The conclusions and results of the report are based on the knowledge and experience acquired by SKB over many years of research and development. The results, and particularly the stipulated criteria, apply to a repository for spent fuel of the KBS-3 type, i.e. a repository where the fuel is contained in copper canisters embedded in bentonite clay at a depth of 400 - 700 m in the Swedish crystalline basement. The report analyzes how the rock's different geological conditions, mechanical, thermal, hydrogeological, chemical and transport properties influence the functions of the deep repository, and whether it is possible to determine requirements and preferences regarding the influence of these properties. Where possible, these requirements or preferences have then been translated into requirements or preferences regarding the individual properties. Criteria are formulated that are based on the quantities that can be measured or estimated at the relevant stage of the investigation. The following requirements are made on the rock: The rock in the repository's deposition zone may not have any ore potential. Regional plastic shear zones shall be avoided if it cannot be demonstrated that the properties of the zone do not deviate from those of the rest of the rock. There may, however, be so-called 'tectonic lenses' near regional plastic shear zones where the bedrock is homogeneous and relatively unaffected. Deposition tunnels and deposition holes for canisters may not pass through or be positioned too close to major regional and major local fracture zones. Deposition holes may not intersect identified local minor fracture zones. The rock's strength, fracture geometry and initial stresses may not be

  5. Groundwater flow modelling of an abandoned partially open repository

    Energy Technology Data Exchange (ETDEWEB)

    Bockgaard, Niclas (Golder Associates AB (Sweden))

    2010-12-15

    As a part of the license application, according to the nuclear activities act, for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study presented here serves as an input for analyses of so-called future human actions that may affect the repository. The objective of the work was to investigate the hydraulic influence of an abandoned partially open repository. The intention was to illustrate a pessimistic scenario of the effect of open tunnels in comparison to the reference closure of the repository. The effects of open tunnels were studied for two situations with different boundary conditions: A 'temperate' case with present-day boundary conditions and a generic future 'glacial' case with an ice sheet covering the repository. The results were summarized in the form of analyses of flow in and out from open tunnels, the effect on hydraulic head and flow in the surrounding rock volume, and transport performance measures of flow paths from the repository to surface

  6. Groundwater flow modelling of an abandoned partially open repository

    International Nuclear Information System (INIS)

    Bockgaard, Niclas

    2010-12-01

    As a part of the license application, according to the nuclear activities act, for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study presented here serves as an input for analyses of so-called future human actions that may affect the repository. The objective of the work was to investigate the hydraulic influence of an abandoned partially open repository. The intention was to illustrate a pessimistic scenario of the effect of open tunnels in comparison to the reference closure of the repository. The effects of open tunnels were studied for two situations with different boundary conditions: A 'temperate' case with present-day boundary conditions and a generic future 'glacial' case with an ice sheet covering the repository. The results were summarized in the form of analyses of flow in and out from open tunnels, the effect on hydraulic head and flow in the surrounding rock volume, and transport performance measures of flow paths from the repository to surface

  7. Status of Proposed Repository for Latin-American Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ferrada, J.J.

    2004-10-04

    This report compiles preliminary information that supports the premise that a repository is needed in Latin America and analyzes the nuclear situation (mainly in Argentina and Brazil) in terms of nuclear capabilities, inventories, and regional spent-fuel repositories. The report is based on several sources and summarizes (1) the nuclear capabilities in Latin America and establishes the framework for the need of a permanent repository, (2) the International Atomic Energy Agency (IAEA) approach for a regional spent-fuel repository and describes the support that international institutions are lending to this issue, (3) the current situation in Argentina in order to analyze the Argentinean willingness to find a location for a deep geological repository, and (4) the issues involved in selecting a location for the repository and identifies a potential location. This report then draws conclusions based on an analysis of this information. The focus of this report is mainly on spent fuel and does not elaborate on other radiological waste sources.

  8. Repository Rodeo Redux

    CERN Document Server

    Anez, Melissa; Donohue, Tim; Fyson, Will; Simko, Tibor; Wilcox, David

    2017-01-01

    You’ve got more repository questions and we’ve got more answers! Last year’s Repository Rodeo panel was a huge success, so we’re taking the show on the road to Brisbane for OR2017. Join representatives from the DSpace, Eprints, Fedora, Hydra, and Islandora communities as we (briefly) explain what each of our repositories actually does. We'll also talk about the directions of our respective technical and community developments, and related to the conference theme of Open: Innovation Knowledge Repositories, offer brief observations about the latest, most promising and/or most surprising innovations in our space. This panel will be a great opportunity for newcomers to Open Repositories to get a crash course on the major repository options and meet representatives from each of their communities. After a brief presentation from each representative, we'll open the session up for questions from the audience.

  9. Characterization of Discharge Areas of Radionuclides Originating From Nuclear Waste Repositories

    Science.gov (United States)

    Marklund, L.; Xu, S.; Worman, A.

    2009-05-01

    If leakages in nuclear waste repositories located in crystalline bedrock arise, radionuclides will reach the biosphere and cause a risk of radiological impact. The extent of the radiological impact depends on in which landscape elements the radionuclides emerge. In this study, we investigate if there are certain landscape elements that generally will act as discharge areas for radionuclides leaking from subsurface deposits. We also characterize the typical properties that distinguish these areas from others. In humid regions, landscape topography is the most important driving force for groundwater flow. Because groundwater is the main transporting agent for migrating radionuclides, the topography will determine the flowpaths of leaking radionuclides. How topography and heterogeneities in the subsurface affect the discharge distribution of the radionuclides is therefore an important scope of this study. To address these issues, we developed a 3-D transport model. Our analyses are based on site-specific data from two different areas in Sweden, Forsmark, Uppland, and Oskarshamn, Småland. The Swedish Nuclear Waste Management Company (SKB) has selected these two areas as candidate areas for a deep repository of nuclear waste and the areas are currently subject to site investigations. Our results suggest that there are hot-spots in the landscape i.e. areas with high probability of receiving large amounts of radionuclides from a leaking repository of nuclear waste. The hot-spots concentrate in the sea, streams, lakes and wetlands. All these elements are found at lower elevations in the landscape. This pattern is mostly determined by the landscape topography and the locations of fracture zones. There is a relationship between fracture zones and topography, and therefore the importance of the topography for the discharge area distribution is not contradicted by the heterogeneity in the bedrock. The varieties of landscape elements which have potential for receiving

  10. CAED Document Repository

    Data.gov (United States)

    U.S. Environmental Protection Agency — Compliance Assurance and Enforcement Division Document Repository (CAEDDOCRESP) provides internal and external access of Inspection Records, Enforcement Actions, and...

  11. Administrative Data Repository (ADR)

    Data.gov (United States)

    Department of Veterans Affairs — The Administrative Data Repository (ADR) was established to provide support for the administrative data elements relative to multiple categories of a person entity...

  12. Swedish Cleantech Opportunities 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    A market overview from the Swedish Energy Agency. 'Cleantech (short for clean technologies) refers to energy and environmentally friendly related technologies. Global demand for this kind of products continues to grow and cleantech can thus generate new jobs, growth and tax revenues. The Swedish Energy Agency is active in the energy segment of cleantech and support companies in their early stages of development. This market overview outlines the current status of the sector, in Sweden and globally. It also presents business leaders and innovators in this field.'

  13. Swedish Cleantech Opportunities 2010

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    A market overview from the Swedish Energy Agency. 'Cleantech (short for clean technologies) refers to energy and environmentally friendly related technologies. Global demand for this kind of products continues to grow and cleantech can thus generate new jobs, growth and tax revenues. The Swedish Energy Agency is active in the energy segment of cleantech and support companies in their early stages of development. This market overview outlines the current status of the sector, in Sweden and globally. It also presents business leaders and innovators in this field.'

  14. How Swedish communities organised themselves in reviewing a safety case

    International Nuclear Information System (INIS)

    Soderblom, Anna-Lena

    2014-01-01

    Full text of publication follows: In 2009 the Swedish nuclear waste management company, SKB, choose Forsmark in the municipality of Oesthammar as the best place for a repository for spent nuclear fuel. In 2011, as a natural follow-up, SKB presented applications to two Swedish authorities, the Land and Environmental Court and the Swedish Radiation Safety Authority. The municipality of Oesthammar has together with the municipality of Oskarshamn been an active part in the process since 1994, with different local organisations financed by the Swedish nuclear fund. Three leading themes form the basis for our participation - voluntarism, complete openness of plans and results and participation with the possibility to influence. Site investigations for a repository started in 2002 and were finished when SKB selected Oesthammar municipality in the middle of 2009. To follow and scrutinise both site investigations as well as the applications, the organisation within the municipality has changed over time. As the site selection process got underway, the municipality extended its organisation to three committees (EIA, long-term safety and consultation). The committees have respective objectives: reviewing the health and environmental impact, reviewing the long-term safety and communication about the work that is going on within and around the municipality. These are primarily political committees to which a unit of civil servants is attached. The main goal for the organisation is to build up knowledge skills and prepare both the existing as well as the future municipality council for the decision of whether or not the municipality of Oesthammar will accept a final repository for spent nuclear fuel in our municipality. The absolutely most important issue for the municipality is long term-safety and as the process has progressed the municipality has made several statements to the authorities. (authors)

  15. 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

  16. 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)

  17. Initial design process of the repository

    International Nuclear Information System (INIS)

    Osmanlioglu, A.E.

    2001-01-01

    The concept of the final disposal of high level wastes is to isolate the waste from the biosphere for extremely long periods of time by emplacement of wastes into deep stable geological formations. Several geological formations have been considered as candidate host environments for high level waste disposal and several techniques have been developed for repository design. In this study, interrelationships of main parameters of a general repository design have been defined and effective parameters are shown at each step. Initial design process is based on the long term stability of underground openings as disposal galleries. For this reason, this design process includes two main analyses: mechanical analysis and thermal analysis. Each of the analysis systems is directly related to each other by technical precautions. As a result of this design process, general information about the acceptable depth of the repository, layout and emplacement pattern can be taken. Final design study can be established on the result of initial design process. (author)

  18. Decommissioning planning of Swedish nuclear power plants

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, Gunnar; Bergh, Niklas [Westinghouse Electric Sweden AB, Vaesteraes (Sweden)

    2013-07-01

    The technologies required for the decommissioning work are for the most part readily proven. Taken into account that there will be many more years before the studied reactor units will undergo decommissioning, the techniques could even be called conventional at that time. This will help bring the decommissioning projects to a successful closure. A national waste fund is already established in Sweden to finance amongst others all dismantling and decommissioning work. This will assure that funding for the decommissioning projects is at hand when needed. All necessary plant data are readily available and this will, combined with a reliable management system, expedite the decommissioning projects considerably. Final repositories for both long- and short-lived LILW respectively is planned and will be constructed and dimensioned to receive the decommissioning waste from the Swedish NPP:s. Since the strategy is set and well thought-through, this will help facilitate a smooth disposal of the radioactive decommissioning waste. (orig.)

  19. The industrial organization of the repository. Pitfall or logical?

    International Nuclear Information System (INIS)

    Frostenson, Magnus

    2010-11-01

    From a systems perspective the organization of the Swedish final repository project for nuclear waste is studied. Different aspects of organization are identified in the report, covering dimensions of geographical, operative, structural, responsibility and contextual organization. Following SKB's site selection for the applications for the final repository for spent nuclear system and the closing of the surplus value agreement, issues concerning operative, structural and contextual organization tend to become particularly pressing, which is reflected in three research questions: - How will the final repository project be organized operatively and structurally over time? - Why is the final repository project organized in this way by SKB? - What kind of contextual organization takes place in the final repository project and what are the consequences of these activities? How the different industrial units of the final repository project should be run and within which structure, for example concerning ownership and integration of units, is established in the report. SKB's reasons for choosing this kind of organization are also highlighted. Apart from legal and safety-related demands that must be met together with the demands of the owners, SKB's strategic preference for insourcing conditions organizational choices. The traditional task centred operative and structural organization of SKB is also reflected in the organizational choices for the present and future units of the final depository system. Contextual organization implies deepened actor relationships between SKB's owners and SKB on the one side and the municipalities Oesthammar and Oskarshamn on the other. Through active organizing, the final repository arena 'narrows down' and the final repository issue turns into an in many respects local issue. There is a clear tendency that the roles of SKB are multiplied in order to handle the demands that central stakeholders - in particular the municipalities - place on

  20. Design process for a repository - KBS-3 case

    International Nuclear Information System (INIS)

    Svemar, C.

    1995-01-01

    This paper deals with the design process for the Swedish (generic) repository design KBS-3. The repository may have a spiral access ramp, access shafts, or straight access ramps. Galleries lead from a central service area to a small spent fuel storage area, a larger main spent fuel storage area, and a disposal area for other nuclear waste. This, or any, design has to be planned through three stages of layout and design, viz. feasibility study, preliminary planning, and architectural design, followed by detailed planning, and then planning of excavation and construction. Decisions on final design have to wait until construction is imminent, and all the rock data are available. This means that different sections of the repository may be at different planning stages at any one time. In the last stage, the plan of the disposal holes depends on detailed coring results, because a hole will not be bored where there is a fracture. 3 refs., 1 tab., 3 figs

  1. Final repository for spent nuclear fuel. Underground design Simpevarp, Layout D1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-04-15

    This report is a compilation of the results of the underground design work carried out in design phase D1 of the Repository Design Project within the Deep Repository Project for the Simpevarp site. Similar reports are also being produced for the Laxemar and Forsmark sites. The design phase coincides with the initial site investigation phase. The main purpose of phase D1 is to answer the question 'Can a final repository be accommodated within the designated site', but also to test the design methodology and provide feedback to the modelling project. Design was carried out in accordance with the methodology described in UDP (Underground Design Premises), SKB R-04-60, and was based on preliminary data from various disciplines in the site modelling project. The preliminary input data used were then cross-checked against data in the final Site Descriptive Model SDM v 1.2 and significant differences were integrated in the design work. The design results from each design topic were presented by the designer at presentation meetings for SKB's design management and the reviewers engaged by SKB for the specific topic. After the presentation meeting the designer wrote up the work reports for the topic in question. The work reports were then reviewed by SKB's review team. The results of the review were compiled in a statement that was submitted to the designer to be dealt with. In the statement the designer documented which comments were dealt with and how. This report is a compilation of the entire design phase D1 for Simpevarp. The 3D layout with coordinate lists for deposition holes and tunnels that was drawn to illustrate a possible layout was used in the Preliminary safety evaluation of the Simpevarp subarea and the hydro modelling of the Open Repository, both activities within the Deep Repository Project. According to current plans for the Swedish nuclear programme, the minimum required number of canister positions in the repository is estimated to be

  2. Preliminary design of the repository, stage 2

    International Nuclear Information System (INIS)

    Saanio, T.; Kirkkomaeki, T.; Keto, P.; Kukkola, T.; Raiko, H.

    2007-01-01

    Spent nuclear fuel from Finnish nuclear power plants will be disposed of in deep bedrock in Olkiluoto, Eurajoki. The repository is planned to be excavated at a depth of 400 - 500 metres. Access routes to the repository include a 1:10 inclined access tunnel, and vertical shafts. The fuel is encapsulated in the encapsulation plant above ground and transferred to the repository in the canister lift. Deposition tunnels, central tunnels and technical rooms are excavated at the disposal level. The canisters are deposited in deposition holes that are covered with bentonite blocks. The deposition holes are bored in the floors of the deposition tunnels. The central tunnel system consists of two parallel central tunnels that are inter-connected at certain distances. Two parallel central tunnels improve the fire safety of the rooms and also allow flexible backfilling and closing of the deposition tunnels in stages at the operational phase of the repository. An underground rock characterization facility, ONKALO, is excavated at the disposal level to support and confirm investigations carried out from above ground. ONKALO is designed so that it can later serve as part of the repository. ONKALO excavations were started in 2004. The repository will be excavated in the 2010s and operation will start in 2020. The fifth nuclear power unit makes the operational phase of the repository very long. Parts of the repository will be excavated and closed over the long operational period. The repository can be constructed at one or several levels. The one-storey alternative is the so-called reference alternative in this preliminary design report. The two-storey alternative is also taken into account in the ONKALO designs. The preliminary designs of the repository are presented as located in Olkiluoto. The location of the repository will be revised when more information on the bedrock has been gained. More detailed data of the circumstances will be obtained from above ground investigations

  3. Preliminary design of the repository. Stage 2

    International Nuclear Information System (INIS)

    Saanio, T.; Kirkkomaeki, T.; Keto, P.; Kukkola, T.; Raiko, H.

    2007-04-01

    Spent nuclear fuel from Finnish nuclear power plants will be disposed of in deep bedrock in Olkiluoto, Eurajoki. The repository is planned to be excavated at a depth of 400 - 500 metres. Access routes to the repository include a 1:10 inclined access tunnel, and vertical shafts. The fuel is encapsulated in the encapsulation plant above ground and transferred to the repository in the canister lift. Deposition tunnels, central tunnels and technical rooms are excavated at the disposal level. The canisters are deposited in deposition holes that are covered with bentonite blocks. The deposition holes are bored in the floors of the deposition tunnels. The central tunnel system consists of two parallel central tunnels that are inter-connected at certain distances. Two parallel central tunnels improve the fire safety of the rooms and also allow flexible backfilling and closing of the deposition tunnels in stages at the operational phase of the repository. An underground rock characterization facility, ONKALO, is excavated at the disposal level to support and confirm investigations carried out from above ground. ONKALO is designed so that it can later serve as part of the repository. ONKALO excavations were started in 2004. The repository will be excavated in the 2010s and operation will start in 2020. The fifth nuclear power unit makes the operational phase of the repository very long. Parts of the repository will be excavated and closed over the long operational period. The repository can be constructed at one or several levels. The one-storey alternative is the so-called reference alternative in this preliminary design report. The two-storey alternative is also taken into account in the ONKALO designs. The preliminary designs of the repository are presented as located in Olkiluoto. The location of the repository will be revised when more information on the bedrock has been gained. More detailed data of the circumstances will be obtained from above ground investigations

  4. Experiences of risk in connection with site selection for a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Biel, A.; Dahlstrand, U.

    1991-03-01

    Describes an investigation of the experiences of risks the the Swedish inhabitants have in connection with site selection for a repository for radioactive waste. The attitudes show a rather complicated picture. It is influenced by such factors as: sex, education and distance to the facility. (KAE)

  5. Gas generation in repositories

    International Nuclear Information System (INIS)

    Biddle, P.; Rees, J.H.; McGahan, D.; Rushbrook, P.E.

    1987-09-01

    The nature and quantities of gases likely to be produced by various processes in repositories for low level and intermediate level radioactive wastes are examined in this preliminary study. Many simplifying assumptions are made where published or experimental data is unavailable. The corrosion of the canisters and metallic components in wastes is likely to be the major gas production process in both types of repository. A significant contribution from microbiological activity is expected to occur in low level repositories, predominantly where no cement grouting of the cans has been carried out. A number of areas for further research, required before a more comprehensive study could be carried out, have been identified. (author)

  6. Centralized mouse repositories.

    Science.gov (United States)

    Donahue, Leah Rae; Hrabe de Angelis, Martin; Hagn, Michael; Franklin, Craig; Lloyd, K C Kent; Magnuson, Terry; McKerlie, Colin; Nakagata, Naomi; Obata, Yuichi; Read, Stuart; Wurst, Wolfgang; Hörlein, Andreas; Davisson, Muriel T

    2012-10-01

    Because the mouse is used so widely for biomedical research and the number of mouse models being generated is increasing rapidly, centralized repositories are essential if the valuable mouse strains and models that have been developed are to be securely preserved and fully exploited. Ensuring the ongoing availability of these mouse strains preserves the investment made in creating and characterizing them and creates a global resource of enormous value. The establishment of centralized mouse repositories around the world for distributing and archiving these resources has provided critical access to and preservation of these strains. This article describes the common and specialized activities provided by major mouse repositories around the world.

  7. 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)

  8. The Swedish Model

    DEFF Research Database (Denmark)

    Kokko, Ari

    2012-01-01

    The main characteristics of ‘the Swedish model’ are arguably related to the country's knowledge-intensive industry and its advanced welfare state. The purpose of this chapter is to discuss the historical development of these two features of the Swedish economy. The first part looks at industrial...... development, highlighting both the reasons for the rapid industrialization in the late 19th century and the subsequent shift from raw materials to human capital and knowledge as the main competitive advantages. The second part turns to the development of welfare state, stressing the gradual increase...... in benefits and coverage as well as the emphasis on universal rather than means-tested benefits. The final part suggests some policy conclusions for today's developing countries and emerging economies....

  9. Understanding large scale groundwater flow to aid in repository siting

    International Nuclear Information System (INIS)

    Davison, C.C.; Brown, A.; Gascoyne, M.; Stevenson, D.R.; Ophori, D.U.

    1996-01-01

    Atomic Energy of Canada Limited (AECL) with support from Ontario Hydro has developed a concept for the safe disposal of Canada's nuclear fuel waste in a deep (500 to 1000 m) mined repository in plutonic rocks of the Canadian Shield. The disposal concept involves the use of multiple engineered and natural barriers to ensure long-term safety. The geosphere, comprised of the enclosing rock mass and the groundwater which occurs in cracks and pores in the rock, is expected to serve as an important natural barrier to the release and migration of wastes from the engineered repository. Although knowledge of the physical and chemical characteristics of the groundwater in the rock at potential repository sites is needed to help design the engineered barriers of the repository it can also be used to aid in repository siting, to take greater advantage of natural conditions in the geosphere to enhance its role as a barrier in the overall disposal system

  10. The swedish challenge

    International Nuclear Information System (INIS)

    Tregouet, R.

    2006-01-01

    Sweden decided to be the first country without petroleum for 2020. The author presents the major energy policy axis implemented by the swedish government to delete the part of the produced energy by the petroleum: development of the renewable energies, research programs of the transportation sector concerning the alternative fuels for the motors, energy efficiency and development of the biomass to replace the nuclear energy. (A.L.B.)

  11. 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.

  12. 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

  13. National Radwaste Repository Mochovce

    International Nuclear Information System (INIS)

    2000-01-01

    In this leaflet the National Radioactive Waste Repository in Mochovce (Repository) is described. The Mochovce National Radioactive Waste Repository is a surface multi-barrier type storage facility for solid and treated solidified radioactive wastes generated from the Slovak Republic nuclear power plants operation and decommissioning, research institutes, laboratories and hospitals. The Repository comprises a system of single- and double-row storage boxes. The first double-row is enclosed by a steel-structure building. The 18 x 6 x 5.5 m storage boxes are made of reinforced concrete. The wall thickness is 600 mm. Two-double-rows, i.e. 80 storage boxes were built as part of Stage I (1 row = 20 storage boxes). Each storage box has a storage capacity of 90 fibre concrete containers of 3.1 m 3 volume. The total storage capacity is 7200 containers with the overall storage volume of 22320 m 3

  14. NIA Aging Cell Repository

    Data.gov (United States)

    Federal Laboratory Consortium — To facilitate aging research on cells in culture, the NIA provides support for the NIA Aging Cell Repository, located at the Coriell Institute for Medical Research...

  15. NIDDK Central Repository

    Data.gov (United States)

    U.S. Department of Health & Human Services — The NIDDK Central Repository stores biosamples, genetic and other data collected in designated NIDDK-funded clinical studies. The purpose of the NIDDK Central...

  16. Managing and Evaluating Digital Repositories

    Science.gov (United States)

    Zuccala, Alesia; Oppenheim, Charles; Dhiensa, Rajveen

    2008-01-01

    Introduction: We examine the role of the digital repository manager, discuss the future of repository management and evaluation and suggest that library and information science schools develop new repository management curricula. Method: Face-to-face interviews were carried out with managers of five different types of repositories and a Web-based…

  17. 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)

  18. MAJOR REPOSITORY DESIGN ISSUES

    International Nuclear Information System (INIS)

    JACK N. BAILEY, DWAYNE CHESTNUT, JAMES COMPTON AND RICHARD D. SNELL

    1997-01-01

    The Yucca Mountain Project is focused on producing a four-part viability assessment in late FY98. Its four components (design, performance assessment, cost estimate, and licensing development plan) must be consistent. As a tool to compare design and performance assessment options, a series of repository pictures were developed for the sequential time phases of a repository. The boundaries of the time phases correspond to evolution in the engineered barrier system (EBS)

  19. Swedish waste management

    International Nuclear Information System (INIS)

    Sandwall, L.

    2004-01-01

    Sweden has a well-functioning organization for managing various types of radioactive waste. There is an interim storage facility for spent nuclear fuel, a final repository for low and intermediate level waste, and a specially-built vessel with transport casks and containers for shipping the radioactive waste between the nuclear installations. (author)

  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. Repository operational criteria analysis

    International Nuclear Information System (INIS)

    Hageman, J.P.; Chowdhury, A.H.

    1992-08-01

    The objective of the ''Repository Operational Criteria (ROC) Feasibility Studies'' (or ROC task) was to conduct comprehensive and integrated analyses of repository design, construction, and operations criteria in 10 CFR Part 60 regulations, considering the interfaces and impacts of any potential changes to those regulations. The study addresses regulatory criteria related to the preclosure aspects of the geologic repository. The study task developed regulatory concepts or potential repository operational criteria (PROC) based on analysis of a repository's safety functions and other regulations for similar facilities. These regulatory concepts or PROC were used as a basis to assess the sufficiency and adequacy of the current criteria in 10 CFR Part 60. Where the regulatory concepts were same as current operational criteria, these criteria were referenced. The operations criteria referenced or the PROC developed are given in this report. Detailed analyses used to develop the regulatory concepts and any necessary PROC for those regulations that may require a minor change are also presented. The results of the ROC task showed a need for further analysis and possible major rule change related to the design bases of a geologic repository operations area, siting, and radiological emergency planning

  2. 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)

  3. 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

  4. 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

  5. Influence of climate on landscape characteristics in safety assessments of repositories for radioactive wastes.

    Science.gov (United States)

    Becker, J K; Lindborg, T; Thorne, M C

    2014-12-01

    In safety assessments of repositories for radioactive wastes, large spatial and temporal scales have to be considered when developing an approach to risk calculations. A wide range of different types of information may be required. Local to the site of interest, temperature and precipitation data may be used to determine the erosional regime (which may also be conditioned by the vegetation characteristics adopted, based both on climatic and other considerations). However, geomorphological changes may be governed by regional rather than local considerations, e.g. alteration of river base levels, river capture and drainage network reorganisation, or the progression of an ice sheet or valley glacier across the site. The regional climate is in turn governed by the global climate. In this work, a commentary is presented on the types of climate models that can be used to develop projections of climate change for use in post-closure radiological impact assessments of geological repositories for radioactive wastes. These models include both Atmosphere-Ocean General Circulation Models and Earth Models of Intermediate Complexity. The relevant outputs available from these models are identified and consideration is given to how these outputs may be used to inform projections of landscape development. Issues of spatial and temporal downscaling of climate model outputs to meet the requirements of local-scale landscape development modelling are also addressed. An example is given of how climate change and landscape development influence the radiological impact of radionuclides potentially released from the deep geological disposal facility for spent nuclear fuel that SKB (the Swedish Nuclear Fuel and Waste Management Company) proposes to construct at Forsmark, Sweden. Copyright © 2014 Elsevier Ltd. All rights reserved.

  6. Procedural method for the development of scenarios in the operational phase following closure of final repositories in deep geological formations. Report on the working package 1. Development of the international status of science and technology concerning methods and tools for operational and long-term safety cases; Vorgehensweise bei der Szenarienentwicklung in der Nachverschlussphase von Endlagern in tiefen geologieschen Formationen. Bericht zum Arbeitspaket 1. Weiterentwicklung des internationalen Stands von Wissenschaft und Technik zu Methoden und Werkzeugen fuer Betriebs- und Langzeitsicherheitsnachweise

    Energy Technology Data Exchange (ETDEWEB)

    Uhlmann, Stephan

    2016-09-15

    For the disposal of high-level radioactive wastes the disposal in deep geological formations is internationally favored. The safety cases include the scientific, technical, administrative and operational safety analyses and arguments, including the management system. According to IAEA the safety case includes site qualification, the design of the facility, construction and operation including an accident analysis, the closure phase and the post-closure phase. The safety case includes the evaluation of radiological risks for several scenarios. The report covers the methodology of scenario assumption in the post-closure phase of repositories in deep geological formations.

  7. Nuclide release calculation in the near-field of a reference HLW repository

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

    2004-01-01

    The HLW-relevant R and D program for disposal of high-level radioactive waste has been carried out at Korea Atomic Energy Research Institute (KAERI) since early 1997 in order to develop a conceptual Korea Reference Repository System for direct disposal of nuclear spent fuel by the end of 2007. A preliminary reference geologic repository concept considering such established criteria and requirements as waste and generic site characteristics in Korea was roughly envisaged in 2003 focusing on the near-field components of the repository system. According to above basic repository concept, which is similar to that of Swedish KBS-3 repository, the spent fuel is first encapsulated in corrosion resistant canisters, even though the material has not yet been determined, and then emplaced into the deposition holes surrounded by high density bentonite clay in tunnels constructed at a depth of about 500 m in a stable plutonic rock body. Not only to demonstrate how much a reference repository is safe in the generic point of view with several possible scenarios and cases associated with a preliminary repository concept by conducting calculations for nuclide release and transport in the near-field components of the repository, even though enough information has not been available that much yet, but also to show a methodology by which a generic safety assessment could be performed for further development of Korea reference repository concept, nuclide release calculation study strongly seems to be necessary

  8. SKB's safety case for a final repository license application

    International Nuclear Information System (INIS)

    Hedin, Allan; Andersson, Johan

    2014-01-01

    The safety assessment SR-Site is a main component in SKB's license application, submitted in March 2011, to construct and operate a final repository for spent nuclear fuel at Forsmark in the municipality of Oesthammar, Sweden. Its role in the application is to demonstrate long-term safety for a repository at Forsmark. The assessment relates to the KBS-3 disposal concept in which copper canisters with a cast iron insert containing spent nuclear fuel are surrounded by bentonite clay and deposited at approximately 500 m depth in saturated, granitic rock. The principal regulatory acceptance criterion, issued by the Swedish Radiation Safety Authority (SSM), requires that the annual risk of harmful effects after closure not exceed 10 -6 for a representative individual in the group exposed to the greatest risk. SSM's regulations also imply that the assessment time for a repository of this type is one million years after closure. The licence applied for is one in a stepwise series of permits, each requiring a safety report. The next step concerns a permit to start excavation of the repository and requires a preliminary safety assessment report (PSAR) covering both operational and post-closure safety. Later steps include permission to commence trial operation, to commence regular operation and to close the final repository. (authors)

  9. Proposals of principles for design of repositories according to KBS-3 for Aberg, Beberg and Ceberg (Arock, Berock and Cerock)

    International Nuclear Information System (INIS)

    Munier, R.; Sandstedt, H.; Niland, L.

    1997-05-01

    Three hypothetical Swedish candidate sites for a radioactive waste repository are examined in this report. Based on geological surveys in the areas, fracture zones have been classified and 'safety distances' to these zones defined. Repository layouts for the different sites were then made after the above data with the deposition tunnels situated at right angels and parallel to the greatest horizontal stress directions. 19 refs, 44 figs

  10. Trust in Digital Repositories

    Directory of Open Access Journals (Sweden)

    Elizabeth Yakel

    2013-06-01

    Full Text Available ISO 16363:2012, Space Data and Information Transfer Systems - Audit and Certification of Trustworthy Digital Repositories (ISO TRAC, outlines actions a repository can take to be considered trustworthy, but research examining whether the repository’s designated community of users associates such actions with trustworthiness has been limited. Drawing from this ISO document and the management and information systems literatures, this paper discusses findings from interviews with 66 archaeologists and quantitative social scientists. We found similarities and differences across the disciplines and among the social scientists. Both disciplinary communities associated trust with a repository’s transparency. However, archaeologists mentioned guarantees of preservation and sustainability more frequently than the social scientists, who talked about institutional reputation. Repository processes were also linked to trust, with archaeologists more frequently citing metadata issues and social scientists discussing data selection and cleaning processes. Among the social scientists, novices mentioned the influence of colleagues on their trust in repositories almost twice as much as the experts. We discuss the implications our findings have for identifying trustworthy repositories and how they extend the models presented in the management and information systems literatures.

  11. Oxidation-reduction reactions. Overview and implications for repository studies

    International Nuclear Information System (INIS)

    Apted, Michael J.; Arthur, Randolph C.; Sasamoto, Hiroshi; Yui, Mikazu; Iwatsuki, Teruki

    2001-02-01

    The purpose of this report is to provide a survey and review on oxidation-reduction ('redox') reactions, with particular emphasis on implications for disposal of high-level waste (HLW) in deep geological formations. As an overview, the focus is on basic principles, problems, and proposed research related specifically to the assessment of redox for a HLW repository in Japan. For a more comprehensive treatment of redox and the myriad associated issues, the reader is directed to the cited textbooks used as primary references in this report. Low redox conditions in deep geological formations is a key assumption in the 'Second Progress Report on Research and Development for the Geological Disposal of HLW in Japan' (hereafter called H12'). The release behavior of multi-valent radioelements (e.g., Tc, Se, U, Pu, Np), as well as daughter radioelements of these radioelements, from a deep geological repository are sensitively related to redox conditions. Furthermore, the performance of certain barrier materials, such as overpack and buffer, may be impacted by redox conditions. Given this importance, this report summarizes some key topics for future technical studies supporting site characterization and repository performance as follows: To fully test the conceptual models for system Eh, it will be necessary to measure and evaluate trace element and isotopic information of both coexisting groundwater and reactive minerals of candidate rocks. Because of importance of volatile species (e.g., O 2 , H 2 etc.) in redox reactions, and given the high total pressure of a repository located 500 to 1000 meter deep, laboratory investigations of redox will necessarily require use of pressurized test devices that can fully simulate repository conditions. The stability (redox capacity) of the repository system with respect to potential changes in redox boundary condition induced by oxidizing waters intrusion should be established experimentally. An overall conceptual model that unifies

  12. Socioeconomic impacts of repositories