PROCESS FOR LICENSE APPLICATION DEVELOPMENT FOR THE GEOLOGIC REPOSITORY

International Nuclear Information System (INIS)

DOUGLAS M. FRANKS AND NORMAN C. HENDERSON

1997-01-01

The Department of Energy (DOE), specifically the Office of Civilian Radioactive Waste Management (OCRWM) has been charged by the U.S. Congress, through the Nuclear Waste Policy Act (NWPA), with the responsibility for obtaining a license to develop a geologic repository. The NRC is the licensing authority for geologic disposal, and its regulations pertinent to construction authorization and license application are specified in 10 CFR Part 60, Disposal of High-Level Radioactive Wastes in Geologic Repositories, (section)60.21ff and (section)60.31ff. This paper discusses the process the Yucca Mountain Site Site Characterization Project (YMP) will use to identify and apply regulatory and industry guidance to development of the license application (LA) for a geologic repository at Yucca Mountain, Nevada. This guidance will be implemented by the ''Technical Guidance Document for Preparation of the License Application'' (TGD), currently in development

Process for license application development for the geologic repository

International Nuclear Information System (INIS)

Franks, D.M.; Henderson, N.C.

1998-01-01

The Department of Energy (DOE), specifically the Office of Civilian Radioactive Waste Management (OCRWM) has been charged by the US Congress, through the Nuclear Waste Policy Act (NWPA), with the responsibility for obtaining a license to develop a geologic repository. The NRC is the licensing authority for geologic disposal, and its regulations pertinent to construction authorization and license application are specified in 10 CFR Part 60, Disposal of High-Level Radioactive Wastes in Geologic Repositories, section 60.21ff and section 60.31ff. This paper discusses the process the Yucca Mountain Site Characterization Project (YMP) will use to identify and apply regulatory and industry guidance to development of the license application (LA) for a geologic repository at Yucca Mountain, Nevada. This guidance will be implemented by the Technical Guidance Document for Preparation of the License Application (TGD), currently in development

Safety analysis of the proposed Canadian geologic nuclear waste repository

International Nuclear Information System (INIS)

Prowse, D.R.

1977-01-01

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

Monitoring of geological repositories for high level radioactive waste

International Nuclear Information System (INIS)

2001-04-01

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

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

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

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

Complex geologic characterization of the repository environment

Energy Technology Data Exchange (ETDEWEB)

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

1982-01-01

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

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)

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)

Geological status of NWTS repository siting activities in the paradox basin

International Nuclear Information System (INIS)

Frazier, N.A.; Conwell, F.R.

1981-01-01

Emplacement of waste packages in mined geological repositories is one method being evaluated for isolating high-level nuclear wastes. Granite, dome salt, tuff, basalt and bedded salt are among the rock types being investigated. Described in this paper is the status of geological activities in the Paradox Basin of Utah and Colorado, one region being explored as a part of the National Waste Terminal Storage (NWTS) program to site a geological repository in bedded salt

Performance Assessment Strategy Plan for the Geologic Repository Program

International Nuclear Information System (INIS)

1990-01-01

Performance assessment is a major constituent of the program being conducted by the US Department of Energy (DOE) to develop a geologic repository. Performance assessment is the set of activities needed for quantitative evaluations to assess compliance with the performance requirements in the regulations for a geologic repository and to support the development of the repository. The strategy for these evaluations has been documented in the Performance Assessment Strategy Plan (DOE, 1989). The implementation of the performance assessment strategy is defined in this document. This paper discusses the scope and objectives of the implementation plan, the relationship of the plan to other program plans, summarizes the performance assessment areas and the integrated strategy of the performance assessment program. 1 fig., 3 tabs

Relationship of engineering geology to conceptual repository design in the Gibson Dome area, Utah

International Nuclear Information System (INIS)

Helgerson, R.; Henderson, N.

1984-01-01

The Paradox Basin in Southeastern Utah is being investigated as a potential site for development of a high-level nuclear waste repository. Geologic considerations are key areas of concern and influence repository design from a number of aspects: depth to the host rock, thickness of the host rock, and hydrologic conditions surrounding the proposed repository are of primary concern. Surface and subsurface investigations have provided data on these key geologic factors for input to the repository design. A repository design concept, based on the surface and subsurface geologic investigations conducted at Gibson Dome, was synthesized to provide needed information on technical feasibility and cost for repository siting decision purposes. Significant features of the surface and subsurface repository facilities are presented. 5 references, 4 figures

Planning and Design Considerations for Geological Repository Programmes of Radioactive Waste

International Nuclear Information System (INIS)

2014-11-01

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

Geological repositories: The last nuclear frontier. International Conference on Geological Repositories: Political and Technical Progress, 8-10 December 2003, Stockholm, Sweden

International Nuclear Information System (INIS)

ElBaradei, M.

2003-01-01

Few issues play so central a role in the public acceptance of nuclear technologies as the management and disposal of spent fuel and radioactive waste. In the current climate, geological repositories have come to be viewed not as one option among many for completing the nuclear fuel cycle, but as the only sustainable solution achievable in the near term. But despite a longstanding agreement among experts that geological disposal can be safe, technologically feasible and environmentally sound, a large part of the general public remains skeptical. This statement deals with the challenges that IAEA is facing to build public confidence related to spent fuel repositories

Nurture of human resources for geological repository program

International Nuclear Information System (INIS)

Fujiwara, A.

2004-01-01

The Japanese geological repository program entered the implementing stage in 2002. At the implementing stage of the program, different sectors need various human resources to conduct their functions. This paper discusses a suitable framework of nurture of the human resources to progress the geological repository program. The discussion is based on considering of specific characters involved in the program and of the multidisciplinary knowledge related to geological disposal. Considering the specific characters of the project, two types of the human resources need to be nurtured. First type is the core persons with the highest knowledge on geological disposal. They are expected to communicate with the various stakeholders and pass down the whole knowledge of the project to the next generation. Another is to conduct the project as the managers, the engineers and the workers. The former human resources can be developed through the broad practice and experience in each sector. The latter human resources can be effectively developed by training of the fundamental knowledge on geological disposal at training centers as well as by conventional on-the-job training. The sectors involved in the program need to take their own roles in the nurture of these human resources. (author)

IAEA perspectives on geological repositories. Address at the international conference on geological repositories, Denver, 1 November 1999

International Nuclear Information System (INIS)

ElBaradei, M.

1999-01-01

In his address at the International Conference on Geological Repositories (Denver, 1 November 1999), the Director General of the IAEA gave a general presentation of the problem of disposal of high-level radioactive waste, and described the current situation in the countries using nuclear energy including present and future Agency's activities

Monitored Geologic Repository Project Description Document

International Nuclear Information System (INIS)

Curry, P. M.

2001-01-01

The primary objective of the Monitored Geologic Repository Project Description Document (PDD) is to allocate the functions, requirements, and assumptions to the systems at Level 5 of the Civilian Radioactive Waste Management System (CRWMS) architecture identified in Section 4. It provides traceability of the requirements to those contained in Section 3 of the ''Monitored Geologic Repository Requirements Document'' (MGR RD) (YMP 2000a) and other higher-level requirements documents. In addition, the PDD allocates design related assumptions to work products of non-design organizations. The document provides Monitored Geologic Repository (MGR) technical requirements in support of design and performance assessment in preparing for the Site Recommendation (SR) and License Application (LA) milestones. The technical requirements documented in the PDD are to be captured in the System Description Documents (SDDs) which address each of the systems at Level 5 of the CRWMS architecture. The design engineers obtain the technical requirements from the SDDs and by reference from the SDDs to the PDD. The design organizations and other organizations will obtain design related assumptions directly from the PDD. These organizations may establish additional assumptions for their individual activities, but such assumptions are not to conflict with the assumptions in the PDD. The PDD will serve as the primary link between the technical requirements captured in the SDDs and the design requirements captured in US Department of Energy (DOE) documents. The approved PDD is placed under Level 3 baseline control by the CRWMS Management and Operating Contractor (M and O) and the following portions of the PDD constitute the Technical Design Baseline for the MGR: the design characteristics listed in Table 1-1, the MGR Architecture (Section 4.1), the Technical Requirements (Section 5), and the Controlled Project Assumptions (Section 6)

Monitored Geologic Repository Project Description Document

International Nuclear Information System (INIS)

Curry, P.

2000-01-01

The primary objective of the Monitored Geologic Repository Project Description Document (PDD) is to allocate the functions, requirements, and assumptions to the systems at Level 5 of the Civilian Radioactive Waste Management System (CRWMS) architecture identified in Section 4. It provides traceability of the requirements to those contained in Section 3 of the ''Monitored Geologic Repository Requirements Document'' (MGR RD) (CRWMS M and O 2000b) and other higher-level requirements documents. In addition, the PDD allocates design related assumptions to work products of non-design organizations. The document provides Monitored Geologic Repository (MGR) engineering design basis in support of design and performance assessment in preparing for the Site Recommendation (SR) and License Application (LA) milestones. The engineering design basis documented in the PDD is to be captured in the System Description Documents (SDDs) which address each of the systems at Level 5 of the CRWMS architecture. The design engineers obtain the engineering design basis from the SDDs and by reference from the SDDs to the PDD. The design organizations and other organizations will obtain design related assumptions directly from the PDD. These organizations may establish additional assumptions for their individual activities, but such assumptions are not to conflict with the assumptions in the PDD. The PDD will serve as the primary link between the engineering design basis captured in the SDDs and the design requirements captured in U.S. Department of Energy (DOE) documents. The approved PDD is placed under Level 3 baseline control by the CRWMS Management and Operating Contractor (M and O) and the following portions of the PDD constitute the Technical Design Baseline for the MGR: the design characteristics listed in Table 2-1, the MGR Architecture (Section 4.1),the Engineering Design Bases (Section 5), and the Controlled Project Assumptions (Section 6)

Monitored Geologic Repository Concept of Operations

International Nuclear Information System (INIS)

Curry, P.M.

1999-01-01

This updated document provides the top level guidance for development of the individual systems for the MGR which will be further developed in the System Description Documents. This document will serve as guidance for the development of functional interface and operational requirements. However, the data and engineering values presented in Monitored Geologic Repository Concept of Operations are provided as estimates or summaries of the current design. The original analyses or supporting documents must be utilized if the data or engineering values are used for design inputs. The concepts presented will be utilized as inputs for the development of operational concepts for the individual systems. It is recognized that the references listed may contain existing data or data which are to be verified. However, the data and engineering values presented will not impact the concepts presented in this technical document. As such, the data and engineering values are not being tracked as To Be Verified data. This revision was created to incorporate changes resulting from Enhanced Design Alternative II and Revision 3, DCN 01, of the Monitored Geologic Repository Requirements (YMP 1999)

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)

Compliance demonstration: What can be reasonably expected from safety assessment for geological repositories?

International Nuclear Information System (INIS)

Zuidema, P.; Smith, P.; Sumerling, T.

1999-01-01

When licensing a nuclear facility, it is important to demonstrate that it will comply with regulatory limits (e.g. individual dose limits) and also show that sufficient attention has been paid to optimisation of facility design and operation, such that any associated radiological impacts will be as low as reasonably achievable (ALARA). In general, in demonstrating compliance, experience can be drawn from the performance of existing and similar facilities, and monitoring plans can be specified that will confirm that actual radiological discharges during operations are within authorised limits for the facility. This is also true in respect of the operational period of a geological repository. For the post-closure phase of a repository, however, it is also necessary to show that possible releases will remain acceptably low even at long times in the future when, it is assumed, control of the facility has lapsed and there is no method of either monitoring releases or taking remedial action in the case of unexpected events or releases. In addition, within each country, a deep geological repository will be a first-of-a-kind development so that compliance arguments can be expected to be rigorously tested without any assistance from the precedent of licensing of similar facilities nationally. This puts heavy, and quite unusual, burdens on the long-term safety assessment for a geological repository to develop a case that is sufficiently strong to demonstrate compliance. This paper focuses on the problem of demonstrating compliance with long-term safety requirements for a geological repository, and explores: the overall aims and special difficulties of demonstrating compliance for a geological repository; the role of safety assessment in demonstrating compliance; the scope for optimisation of a geological repository and importance of robustness and lessons learnt from the application of safety assessment. In addition, some issues requiring further discussion and clarification

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)

Safeguards policy and strategies: An IAEA perspective for spent fuel in geological repositories

International Nuclear Information System (INIS)

Fattah, A.

2002-01-01

Safeguards for nuclear materials in geologic repositories have to be continued even after the repository has been backfilled and sealed. The nuclear materials disposed in a geologic repository may pose a higher and long-term proliferation risk because the inventory is many times the 'significant quantity' needed safeguards. The safeguards measures must be flexible enough to respond to the changing development of technology and changing need for current as well as future generations. Change in social, economic, environmental and other scenarios might demand recovery of nuclear and other materials from the repository sometime in the future. (author)

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)

The influence of geological loading on the structural integrity of an underground nuclear waste repository

International Nuclear Information System (INIS)

Jakeman, N.

1985-08-01

Stresses are developed in underground nuclear waste repositories as a result of applied loads from geological movements caused by the encroachment of ice sheets or seismic activity for example. These stresses may induce fracturing of the waste matrix, repository vault and nearfield host geology. This fracturing will enhance the advective flow and allow more-rapid transfer of radionuclides from their encapsulation through the repository barriers and nearfield host rock. Geological loads may be applied either gradually as in crustal folding or encroachment of ice sheets, or rapidly as in the case of seismic movements. The analysis outlined in this report is conducted with a view to including the effects of geological loading in a probabilistic repository site assessment computer code such as SYVAC. (author)

Environmental impact assessments and geological repositories for radioactive waste

International Nuclear Information System (INIS)

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

1999-01-01

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

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

International Nuclear Information System (INIS)

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

1979-11-01

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

Staff Technical Position on consideration of fault displacement hazards in geologic repository design

International Nuclear Information System (INIS)

McConnell, K.I.; Lee, M.P.

1994-09-01

Nuclear Regulatory Commission regulations for the disposal of spent nuclear fuel and high-level radioactive waste in a geologic repository recognize that fault displacement is a potentially adverse condition. However, they do not prohibit designing the geologic repository against the effects of such a potentially adverse condition. This Staff Technical Position recognizes the acceptability of designing the geologic repository to take into account the attendant effects (e.g., displacement) of faults of regulatory concern and expresses the staff's views on what is needed from the US Department of Energy if it chooses to locate structures, systems, and components important to safety or important to waste isolation in areas that contain faults of regulatory concern

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

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

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.

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)

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

Evolution of waste-package design at the potential U.S. geologic repository

International Nuclear Information System (INIS)

Benton, H.; Harkins, B.

2000-01-01

This paper describes the evolution of the waste-package design at the potential geologic repository for spent nuclear fuel and high-level waste at Yucca Mountain in Nevada. Because the potential repository is the first of its kind, the design of its components must be flexible and capable of evolving in response to continuing scientific study, development efforts, and changes to performance criteria. The team of scientists and engineers at the Yucca Mountain Project has utilized a systematic, scientific approach to design the potential geologic nuclear-waste repository. As a result of continuing development efforts, the design has incorporated a growing base of scientific and engineering information to ensure that regulatory and performance requirements are met. (authors)

Safety assessment of geologic repositories for nuclear waste

International Nuclear Information System (INIS)

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

1977-01-01

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

The Pangea concept for an international radioactive waste repository

International Nuclear Information System (INIS)

Kurzeme, M.

1999-01-01

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

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)

Retrievability of high-level nuclear waste from geologic repositories - Regulatory and rock mechanics/design considerations

International Nuclear Information System (INIS)

Tanious, N.S.; Nataraja, M.S.; Daemen, J.J.K.

1987-01-01

Retrievability of nuclear waste from high-level geologic repositories is one of the performance objectives identified in 10CFR60 (Code of Federal Regulations, 1985). 10CFR60.111 states that the geologic repository operations area shall be designed to preserve the option of waste retrieval. In designing the repository operations area, rock mechanics considerations play a major role especially in evaluating the feasibility of retrieval operations. This paper discusses generic considerations affecting retrievability as they relate to repository design, construction, and operation, with emphasis on regulatory and rock mechanics aspects

Release consequence analysis for a hypothetical geologic radioactive waste repository in salt

International Nuclear Information System (INIS)

1979-08-01

One subtask conducted under the INFCE program is to evaluate and compare the health and safety impacts of different fuel cycles in which all radioactive wastes (except those from mining and milling) are placed in a geologic repository in salt. To achieve this objective, INFCE Working Group 7 examined the radiologic dose to humans from geologic repositories containing waste arisings as defined for seven reference fuel cycles. This report examines the release consequences for a generic waste repository in bedded salt. The top of the salt formation and the top of the repository are assumed to be 250 and 600 m, respectively, below the surface. The hydrogeologic structure above the salt consists of two aquifers and two aquitards. The aquifers connect to a river 6.2 km from the repository. The regional gradient to the river is 1 m/km in all aquifers. Hydrologic, transport, and dose models were used to model two release scenarios for each fuel cycle, one without a major disturbance and one in which a major geologic perturbation breached the repository immediately after it was sealed. The purpose of the modeling was to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere, and to determine the potential dose to humans. Of the many radionuclides in the waste, only 129 I and 226 Ra arrived at the river in sufficient concentrations for a measurable dose calculation. Radionuclide concentrations in the ground water pose no threat to man because the ground water is a concentrated brine and it is diluted by a factor of 10 6 to 10 7 upon entering the river

Site characterization information needs for a high-level waste geologic repository

International Nuclear Information System (INIS)

Gupta, D.C.; Nataraja, M.S.; Justus, P.S.

1987-01-01

At each of the three candidate sites recommended for site characterization for High-Level Waste Geologic Repository development, the DOE has proposed to conduct both surface-based testing and in situ exploration and testing at the depths that wastes would be emplaced. The basic information needs and consequently the planned surface-based and in situ testing program will be governed to a large extent by the amount of credit taken for individual components of the geologic repository in meeting the performance objectives and siting criteria. Therefore, identified information to be acquired from site characterization activities should be commensurate with DOE's assigned performance goals for the repository system components on a site-specific basis. Because of the uncertainties that are likely to be associated with initial assignment of performance goals, the information needs should be both reasonably and conservatively identified

Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

Energy Technology Data Exchange (ETDEWEB)

Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

2003-11-15

The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

Evaluation of Five Sedimentary Rocks Other Than Salt for Geologic Repository Siting Purposes

International Nuclear Information System (INIS)

Croff, A.G.; Lomenick, T.F.; Lowrie, R.S.; Stow, S.H.

2003-01-01

The US Department of Energy (DOE), in order to increase the diversity of rock types under consideration by the geologic disposal program, initiated the Sedimary ROck Program (SERP), whose immediate objectiv eis to evaluate five types of secimdnary rock - sandstone, chalk, carbonate rocks (limestone and dolostone), anhydrock, and shale - to determine the potential for siting a geologic repository. The evaluation of these five rock types, together with the ongoing salt studies, effectively results in the consideration of all types of relatively impermeable sedimentary rock for repository purposes. The results of this evaluation are expressed in terms of a ranking of the five rock types with respect to their potential to serve as a geologic repository host rock. This comparative evaluation was conducted on a non-site-specific basis, by use of generic information together with rock evaluation criteria (RECs) derived from the DOE siting guidelines for geologic repositories (CFR 1984). An information base relevant to rock evaluation using these RECs was developed in hydrology, geochemistry, rock characteristics (rock occurrences, thermal response, rock mechanics), natural resources, and rock dissolution. Evaluation against postclosure and preclosure RECs yielded a ranking of the five subject rocks with respect to their potential as repository host rocks. Shale was determined to be the most preferred of the five rock types, with sandstone a distant second, the carbonate rocks and anhydrock a more distant third, and chalk a relatively close fourth.

Proceedings of the workshop on radionuclide release scenarios for geologic repositories

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

The safety of radioactive waste disposal in geological formations cannot be verified experimentally. Safety analysis provides the only means to ensure that all risks associated with the waste repositories are acceptably low. The definition of radionuclide release scenarios, as discussed in these proceeedings, is the first step in the safety analysis of waste repositories.

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

Stockholm international conference 2003 on geological repositories: Political and technical progress

International Nuclear Information System (INIS)

2004-01-01

The conference reviewed global progress made as well as current perspectives on the activities to develop geologic repositories. The objectives were to review the progress in policy making as well as technical issues and to strengthen international co-operation on waste management and disposal issues. The first day of the conference addressed the policy aspects of geological repositories and the second day featured the more technical issues. Session 1: International progress in performing long-term safety studies and security of geological disposal were discussed and reviewed with examples from OECD/NEA, Belgium, Sweden, USA, Switzerland and Russia. Session 2: Views on stakeholder involvement and decision making process were presented by international organisations and national implementers from Japan, United Kingdom, Belgium and OECD/NEA. Session 3: Views on stakeholder involvement and decision making process were presented by regional and local stakeholders from France, Finland, Korea and Sweden. Session 4: International instruments assisting in the implementation of geological repositories were discussed, for example ICRP and IAEA/NEA safety documents, Joint Convention, Safeguard agreements, Nuclear Liability Conventions, etc. Session 5: The contribution of Research, Development and Demonstration was discussed with overviews of the progress achieved on scientific and technical issues over the past four years. Progress and key issues were presented from Switzerland, USA, Finland, Japan, Sweden and IAEA. Each of the papers and poster presentations have been analysed and indexed separately

Reference design description for a geologic repository. Revision 02

International Nuclear Information System (INIS)

1999-01-01

This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada. It describes the proposed design for a surface facility, subsurface repository, and waste packaging; it also presents the current design of the key engineering systems for the final four phases: operations, monitoring, closure, and postclosure. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. In accordance with current law, this design does not include an interim storage option. This document has six major sections. Section 1 describes the physical layout of the proposed repository. The second section describes the 4-phase evolution of the development of the proposed repository. Section 3 describes the reception of waste from offsite locations. The fourth section details the various systems that will package the waste and move it below ground as well as safety monitoring and closure. Section 5 describes the systems (both physical and analytical) that ensure continued safety after closure. The final section offers design options that may be adopted to increase the margin of safety

International Conference on Geological Repositories 2016. Conference Synthesis, 7-9 December 2016, Paris, France

International Nuclear Information System (INIS)

Walke, Russell; Kwong, Gloria; )

2017-01-01

Worldwide consensus exists within the international community that geological repositories can provide the necessary long-term safety and security to isolate long-lived radioactive waste from the human environment over long timescales. Such repositories are also feasible to construct using current technologies. However, proving the technical merits and safety of repositories, while satisfying societal and political requirements, has been a challenge in many countries. Building upon the success of previous conferences held in Denver (1999), Stockholm (2003), Berne (2007) and Toronto (2012), the ICGR 2016 brought together high-level decision makers from regulatory and local government bodies, waste management organisations and public stakeholder communities to review current perspectives of geological repository development. This publication provides a synthesis of the 2016 conference on continued engagement and safe implementation of repositories, which was designed to promote information and experience sharing, particularly in the development of polices and regulatory frameworks. Repository safety, and the planning and implementation of repository programs with societal involvement, as well as ongoing work within different international organisations, were also addressed at the conference. (authors)

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.

Spent fuel performance in geologic repository environments

International Nuclear Information System (INIS)

Bradley, D.J.

1985-10-01

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

Environmental impact assessments and geological repositories: A model process

International Nuclear Information System (INIS)

Webster, S.

2000-01-01

In a recent study carried out for the European Commission, the scope and application of environmental impact assessment (EIA) legislation and current EIA practice in European Union Member States and applicant countries of Central and Eastern Europe was investigated, specifically in relation to the geological disposal of radioactive waste. This paper reports the study's investigations into a model approach to EIA in the context of geological repositories, including the role of the assessment in the overall decision processes and public involvement. (author)

Development of an international safeguards approach to the final disposal of spent fuel in geological repositories

International Nuclear Information System (INIS)

Murphey, W.M.; Moran, B.W.; Fattah, A.

1996-01-01

The International Atomic Energy Agency (IAEA) is currently pursuing development of an international safeguards approach for the final disposal of spent fuel in geological repositories through consultants meetings and through the Program for Development of Safeguards for Final Disposal of Spent Fuel in Geological Repositories (SAGOR). The consultants meetings provide policy guidance to IAEA; SAGOR recommends effective approaches that can be efficiently implemented by IAEA. The SAGOR program, which is a collaboration of eight Member State Support Programs (MSSPs), was initiated in July 1994 and has identified 15 activities in each of three areas (i.e. conditioning facilities, active repositories, and closed repositories) that must be performed to ensure an efficient, yet effective safeguards approach. Two consultants meetings have been held: the first in May 1991 and the last in November 1995. For nuclear materials emplaced in a geological repository, the safeguards objectives were defined to be (1) to detect the diversion of spent fuel, whether concealed or unconcealed, from the repository and (2) to detect undeclared activities of safeguards concern (e.g., tunneling, underground reprocessing, or substitution in containers)

A safeguards approach for a closed geological repository for spent fuel

International Nuclear Information System (INIS)

Meer, K. van der; Carchon, R.

1999-01-01

After closure of a geological repository a diversion of fissile material can only take place by excavating spent fuel containers and bringing them to the surface. Therefore mining activities are required, either by reopening the original shaft, by creating a new shaft or by approaching the containers underground via a neighbouring mine The recovery time of the stored spent fuel plays an important role in the determination of the timeliness criterion and, therefore, the inspection frequency of the site. Obviously, this frequency can create a financial constraint due to the infinite character of the spent fuel storage in a geological repository. Anomalies for detection of a possible diversion are undeclared mining activities. The safeguards approach has to assure Continuity Of Knowledge (COK) of the fissile material. By consequence, a safeguards approach that is developed for a closed repository, is influenced by the safeguards approach applied to an open. repository and a conditioning facility. A closed repository is verified by DIV. To perform the DIV satellite monitoring could be performed for surface verification and e.g. seismic techniques could be used for verification that no undeclared mining activities underground take place. Visual inspections of the site by inspectors have to reveal concealment methods used by a potential diverter. These measures should guarantee that the disposed spent fuel remains untouched. (author)

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.

AEGIS geologic simulation model

International Nuclear Information System (INIS)

Foley, M.G.

1982-01-01

The Geologic Simulation Model (GSM) is used by the AEGIS (Assessment of Effectiveness of Geologic Isolation Systems) program at the Pacific Northwest Laboratory to simulate the dynamic geology and hydrology of a geologic nuclear waste repository site over a million-year period following repository closure. The GSM helps to organize geologic/hydrologic data; to focus attention on active natural processes by requiring their simulation; and, through interactive simulation and calibration, to reduce subjective evaluations of the geologic system. During each computer run, the GSM produces a million-year geologic history that is possible for the region and the repository site. In addition, the GSM records in permanent history files everything that occurred during that time span. Statistical analyses of data in the history files of several hundred simulations are used to classify typical evolutionary paths, to establish the probabilities associated with deviations from the typical paths, and to determine which types of perturbations of the geologic/hydrologic system, if any, are most likely to occur. These simulations will be evaluated by geologists familiar with the repository region to determine validity of the results. Perturbed systems that are determined to be the most realistic, within whatever probability limits are established, will be used for the analyses that involve radionuclide transport and dose models. The GSM is designed to be continuously refined and updated. Simulation models are site specific, and, although the submodels may have limited general applicability, the input data equirements necessitate detailed characterization of each site before application

Safeguarding of spent fuel conditioning and disposal in geological repositories

International Nuclear Information System (INIS)

Forsstroem, H.; Richter, B.

1997-01-01

Disposal of spent nuclear fuel in geological formations, without reprocessing, is being considered in a number of States. Before disposal the fuel will be encapsulated in a tight and corrosion resistant container. The method chosen for disposal and the design of the repository will be determined by the geological conditions and the very strict requirements on long-term safety. From a safeguards perspective spent fuel disposal is a new issue. As the spent fuel still contains important amounts of material under safeguards and as it can not be considered practicably irrecoverable in the repository, the IAEA has been advised not to terminate safeguards, even after closure of the repository. This raises a number of new issues where there could be a potential conflict of interests between safety and safeguards demands, in particular in connection with the safety principle that burdens on future generations should be avoided. In this paper some of these issues are discussed based on the experience gained in Germany and Sweden about the design and future operation of encapsulation and disposal facilities. The most important issues are connected to the required level of safeguards for a closed repository, the differences in time scales for waste management and safeguards, the need for verification of the fissile content in the containers and the possibility of retrieving the fuel disposed of. (author)

The general situation of clay site for high-level waste geological disposal repository

International Nuclear Information System (INIS)

Wang Changxuan; Liu Xiaodong; Liu Pinghui

2008-01-01

Host medium is vitally important for safety of high-level radiaoactive waste (HLW) geological disposal. Clay, as host media of geological repository of HLW, has received greater attention for its inherent advantages. This paper summarizes IAEA and OECD/NEA's some safety guides on site selection and briefly introduces the process of the site selection, their studies and the characteristics of the clay formations in Switz-erland, France and Belgian. Based on these analyses, some suggestions are made to China's HLW repository clay site selection. (authors)

NAGRA - Sites for geological repositories - Technical safety factors: Suggestions for stage 3

International Nuclear Information System (INIS)

2015-01-01

This comprehensive brochure published by the Swiss National Cooperative for the Disposal of Radioactive Waste (NAGRA) examines the six sites for repositories for nuclear wastes in Switzerland which have been proposed in Stage 1 of the program concerning nuclear waste repositories. Three of these sites are proposed for both highly radioactive wastes as well as for low and medium-active wastes, the other three for low and medium-active wastes only. The evaluation of the sites is discussed. The sites are to be further evaluated in Stage 2 of the program. The work to be done in the further stages involved in the selection of the final site (or sites) is described. Along with definition of the regions where deep repositories could possibly be built, suggestions for the placing of the facilities required on the surface are discussed. Geological requirements on the repositories and safety-relevant characteristics of the various site options are discussed. The results of the assessments made are presented in tabular form. Maps and geological cross-sections of all the suggested areas are included

Study on a monitoring strategy to support decision making for geological repository closure

International Nuclear Information System (INIS)

Suyama, Yasuhiro; Tanabe, Hiromi; Eto, Jiro; Yoshimura, Kimitaka

2010-01-01

Japan currently plans to dispose of high-level radioactive wastes (vitrified HLWs) produced from the reprocessing of spent nuclear fuel in deep geological formations, in order to isolate the radioactive wastes from the human environment for tens of thousands of years. Such a geological repository must be designed to ensure operational safety and post-closure safety. Then, following the closure of the geological repository, post-closure safety will be provided by an engineered barrier system (EBS) and a natural barrier system (NBS) without relying on monitoring or institutional control. However, from a technical standpoint, monitoring has been required during backfilling in current studies. Additionally, there has been strong social pressure to continue monitoring during all the phases including post-closure. On the basis of the current situations, a monitoring strategy for geological disposal must be studied to ensure the long term safety of geological disposal. Focusing on decision making for geological repository closure, the authors have created a basic logical structure for the decision making process with the principles for ensuring safety and have developed a monitoring strategy based on the logical structure. The monitoring strategy is founded on three key aspects: the role of monitoring, boundary conditions of monitoring at the time of decision making, and a methodology for monitoring planning. Then, the monitoring strategy becomes a starting point of monitoring planning during site characterization, construction, operation and staged closure, as well as post-closure with institutional control, and of social science studies. (author)

Reference design description for a geologic repository: Revision 01

International Nuclear Information System (INIS)

1997-09-01

This document describes the current design expectations for a potential geologic repository that could be located at Yucca Mountain in Nevada. This Reference Design Description (RDD) looks at the surface and subsurface repository and disposal container design. Additionally, it reviews the expected long-term performance of the potential repository. In accordance with current legislation, the reference design for the potential repository does not include an interim storage option. The reference design presented allows the disposal of highly radioactive material received from government-owned spent fuel custodian sites; produces high-level waste sites, and commercial spent fuel sites. All design elements meet current federal, state, and local regulations governing the disposal of high-level radioactive waste and protection of the public and the environment. Due to the complex nature of developing a repository, the design will be created in three phases to support Viability Assessment, License Application, and construction. This document presents the current reference design. It will be updated periodically as the design progresses. Some of the details presented here may change significantly as more cost-effective solutions, technical advancements, or changes to requirements are identified

Plans for characterization of the potential geologic repository site at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Dobson, D.C.; Blanchard, M.B.; Voegele, M.D.; Younker, J.L.

1990-01-01

Site investigations in the vicinity of the potential repository site at Yucca Mountain, Nevada, have occurred for many years. Although information from previous site investigations was adequate to support preliminary evaluations by the US Department of Energy (DOE) in the Environmental Assessment and to develop conceptual repository and waste package designs, this information is insufficient to proceed to the advanced designs and performance assessments required for the license application to the US Nuclear Regulatory Commission (NRC). Therefore, intensive site characterization is planned, as described in the December 1988 Site Characterization Plan (SCP). The data acquisition activities described in the SCP are focused on obtaining information to allow evaluations of the natural and engineered barriers considered potentially relevant to repository performance. The site data base must be adequate to allow predictions of the range of expected variation in geologic conditions over the next 10,000 years, as well as predictions of the probabilities for catastrophic geologic events that could affect repository performance. 4 refs., 4 figs

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)

LISA: A performance assessment code for geological repositories of radioactive waste

International Nuclear Information System (INIS)

Bertozzi, G.; Saltelli, A.

1985-01-01

LISA, developed at JRC-Ispra, is a statistical code, which calculates the radiation exposures and risks associated with radionuclide releases from geological repositories of nuclear waste. The assessment methodology is described briefly. It requires that a number of probabilistic components be quantified and introduced in the analysis; the results are thus expressed in terms of risk. The subjective judgment of experts may be necessary to quantify the probabilities of occurrence of rare geological events. Because of large uncertainties in input data, statistical treatment of the Monte Carlo type is utilized for the analysis; thus, the output from LISA is obtained in the form of distributions. A few results of an application to a probabilistic scenario for a repository mined in a clay bed are illustrated

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

Safe disposal of radioactive waste. Post-closure safety assessment of permanent repository in Novi han

International Nuclear Information System (INIS)

Mateeva, M.

2007-01-01

A presented material is the third part of the monograph with title 'Safe disposal of radioactive waste. Post-closure safety assessment of the permanent repository in Novi Han'. This part deals with review of the scenario selection procedure. The process system of permanent repository for radioactive waste is describing in details for different levels. Preliminary screening process of features, events and processes is presented here. Interaction matrixes for basic disposal system components are constructed. Final selection and grouping between the included features, events and processes is done. Selected and defined scenarios for post-closure safety assessment are presented too. Key words: post-closure safety assessment, scenario generation procedure, process system, process influence diagram, and interaction matrix

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)

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

International Nuclear Information System (INIS)

1977-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

1977-01-01

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

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

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

Setting waste isolation times into a geological context: some experience with natural analogues in public information

International Nuclear Information System (INIS)

Fritschi, Markus

2008-01-01

The concept of geological repositories: Permanent protection of humans and the environment by long-term passive isolation of the radioactive materials from the environment. Permanent means until radioactivity has decayed to insignificant levels (Many tens of thousands of years up to one million years into the future). Human experience with timescales: - Personal: Some 10 years, maybe up to 2 to (3) generations; - 'Rapid' (normally experienced as slow) and relevant changes with regard to personal well-being during this time span; - 100 years of European history; - Human History up to 5,000 years: but relevant to experience? So there is a complete mismatch of personal experience with the question addressed in the safety case. Understandable explanation of a geological repository: - Why is a geological repository necessary? - Why are geological repositories safe? - How can one be sure, what happens in 100,000 years? Radioactive waste must be disposed of in a way to ensure permanent protection of humans and the environment (Swiss Nuclear Energy Law). A Containment is thus necessary. Today's containment (storage) needs maintenance, but how about stability of society? How about the future development on the surface where we live? Passive safety is based on multiple barrier system: passive containment without the need of maintenance in a geological environment. Requirements on the host rock and the geosphere: Sound science and expertise is available for all the components. The need for translation: What pictures do you use to explain the functioning of a geological repository over long time scales? Pictures, Symbols, 'Analogues' must be adapted to the specific situation in a country. So whatever may happen on the surface over the next one million years: Time stands still in the underground

Limits on the thermal energy release from radioactive wastes in a mined geologic repository

International Nuclear Information System (INIS)

Scott, J.A.

1983-03-01

The theraml energy release of nuclear wastes is a major factor in the design of geologic repositories. Thermal limits need to be placed on various aspets of the geologic waste disposal system to avoid or retard the degradation of repository performance because of increased temperatures. The thermal limits in current use today are summarized in this report. These limits are placed in a hierarchial structure of thermal criteria consistent with the failure mechanism they are trying to prevent. The thermal criteria hierarchy is used to evaluate the thermal performance of a sample repository design. The design consists of disassembled BWR spent fuel, aged 10 years, close packed in a carbon steel canister with 15 cm of crushed salt backfill. The medium is bedded salt. The most-restrictive temperature for this design is the spent-fuel centerline temperature limit of 300 0 C. A sensitivity study on the effects of additional cooling prior to disposal on repository thermal limits and design is performed

Logistics Modeling of Emplacement Rate and Duration of Operations for Generic Geologic Repository Concepts

Energy Technology Data Exchange (ETDEWEB)

Kalinina, Elena Arkadievna; Hardin, Ernest

2015-11-01

This study identified potential geologic repository concepts for disposal of spent nuclear fuel (SNF) and (2) evaluated the achievable repository waste emplacement rate and the time required to complete the disposal for these concepts. Total repository capacity is assumed to be approximately 140,000 MT of spent fuel. The results of this study provide an important input for the rough-order-of-magnitude (ROM) disposal cost analysis. The disposal concepts cover three major categories of host geologic media: crystalline or hard rock, salt, and argillaceous rock. Four waste package sizes are considered: 4PWR/9BWR; 12PWR/21BWR; 21PWR/44BWR, and dual purpose canisters (DPCs). The DPC concepts assume that the existing canisters will be sealed into disposal overpacks for direct disposal. Each concept assumes one of the following emplacement power limits for either emplacement or repository closure: 1.7 kW; 2.2 kW; 5.5 kW; 10 kW; 11.5 kW, and 18 kW.

Logistics Modeling of Emplacement Rate and Duration of Operations for Generic Geologic Repository Concepts

International Nuclear Information System (INIS)

Kalinina, Elena Arkadievna; Hardin, Ernest

2015-01-01

This study identified potential geologic repository concepts for disposal of spent nuclear fuel (SNF) and (2) evaluated the achievable repository waste emplacement rate and the time required to complete the disposal for these concepts. Total repository capacity is assumed to be approximately 140,000 MT of spent fuel. The results of this study provide an important input for the rough-order-of-magnitude (ROM) disposal cost analysis. The disposal concepts cover three major categories of host geologic media: crystalline or hard rock, salt, and argillaceous rock. Four waste package sizes are considered: 4PWR/9BWR; 12PWR/21BWR; 21PWR/44BWR, and dual purpose canisters (DPCs). The DPC concepts assume that the existing canisters will be sealed into disposal overpacks for direct disposal. Each concept assumes one of the following emplacement power limits for either emplacement or repository closure: 1.7 kW; 2.2 kW; 5.5 kW; 10 kW; 11.5 kW, and 18 kW.

Office of Geologic Repositories issues hierarchy for a mined geologic disposal system

International Nuclear Information System (INIS)

1987-08-01

The Nuclear Regulatory Commission (NRC) has indicated that the identification of the issues that must be resolved to complete licensing assessments of site and design suitability is an important step in the licensing process. The issues hierarchy developed by the Office of Geologic Repositories (OGR) for the mined geologic disposal system (MGDS) are based on the issues-hierarchy concept presented in the Mission Plan. Specific questions are encompassed by the general issue statements in the OGR issues hierarchy. The OGR issues hierarchy is limited to the issues related to the siting and licensing requirements of applicable federal regulations and does not address the requirements of other regulations, functional or operating requirements for the MGDS, or requirements for the integration and the design/operational efficiency of the MGDS. 4 figs

On ocean island geological repository - a second-generation option for disposal of spent fuel and high-level waste

International Nuclear Information System (INIS)

Forsberg, C.W.

1993-01-01

The concept of an ocean subseabed geological high-level waste repository with access via an ocean island is discussed. The technical advantages include, in addition to geologic waste isolation, geographical isolation, near-zero groundwater flow through the disposal site, and near-infinite ocean dilution as a backup in the event of a failure of the repository geological waste isolation system. The institutional advantages may include reduced siting problems and the potential of creating an international waste repository. Establishment of a repository accepting wastes from many countries would allow cost sharing, aid international nonproliferation goals, and ensure proper disposal of spent fuel from developing countries. Major uncertainties that are identified in this concept are the uncertainties in rock conditions at waste disposal depths, costs, and ill-defined institutional issues

Geologic, stratigraphic, thermal, and mechanical factors which influence repository design in the bedded salt environment

International Nuclear Information System (INIS)

Ashby, J.P.; Nair, O.; Ortman, D.; Rowe, J.

1979-12-01

This report describes the geologic, stratigraphic, thermal, and mechanical considerations applicable to repository design. The topics discussed in the report include: tectonic activity; geologic structure; stratigraphy; rock mechanical properties; and hydrologic properties

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.

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.)

Crystalline Repository Project. Technical progress report, October 1982-March 1983

International Nuclear Information System (INIS)

1985-01-01

This document reports the progress being made periodically on the development of a geologic repository in crystalline rock for the permanent disposal of high-level nuclear waste. The reporting elements are arranged by the work breakdown structure so that related studies are presented together. The studies are reported by the Office of Crystalline Respository Development (OCRD), a prime contractor of the US Department of Energy Repository Project Office. The studies include work by other prime contractors and by subcontractors to OCRD

Preclosure seismic design methodology for a geologic repository at Yucca Mountain. Topical report YMP/TR-003-NP

International Nuclear Information System (INIS)

1996-10-01

This topical report describes the methodology and criteria that the U.S. Department of Energy (DOE) proposes to use for preclosure seismic design of structures, systems, and components (SSCs) of the proposed geologic repository operations area that are important to safety. Title 10 of the Code of Federal Regulations, Part 60 (10 CFR 60), Disposal of High-Level Radioactive Wastes in Geologic Repositories, states that for a license to be issued for operation of a high-level waste repository, the U.S. Nuclear Regulatory Commission (NRC) must find that the facility will not constitute an unreasonable risk to the health and safety of the public. Section 60.131 (b)(1) requires that SSCs important to safety be designed so that natural phenomena and environmental conditions anticipated at the geologic repository operations area will not interfere with necessary safety functions. Among the natural phenomena specifically identified in the regulation as requiring safety consideration are the hazards of ground shaking and fault displacement due to earthquakes

'Kozloduy' NPP geological environment as a barrier against radionuclide migration

International Nuclear Information System (INIS)

Antonov, D.

2000-01-01

The aim of this report is to present an analysis of the geological settings along Kozloduy NPP area from the viewpoint of a natural, protective barrier against unacceptable radionuclides migration in the environment. Possible sources of such migration could be an eventual accident in an active nuclear plant; radioactive releases from decommissioned Power Units or from temporary or permanent radioactive waste repositories. The report is directed mainly to the last case, and especially to the site selection for near surface short lived low and intermediate level (LILW) radioactive repository. The main conclusion of the geological settings assessment and of the many years monitoring is that the Kozloduy NPP area offers good possibilities for site selection of LILW repository. (author)

NAGRA - Sites for geological repositories - Geological surveys 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) examines the aims involved in the selection of sites for deep geological repositories for nuclear wastes in Switzerland. Various methods involved in their implementation are described. These include 3D-seismology, deep probe drillings, shallow drillings as well as field studies, gravimetric measurements and the study of the electrical properties of the ground and rock involved. These factors are discussed in detail. Maps are presented of the locations that are to be surveyed and details of the selected perimeters are shown. Also, the layout of a sample drilling site is presented. A timescale for the various surveys and work to be done is presented

A geologic scenario for catastrophic failure of the Yucca Mountain Nuclear Waste Repository, Nevada

International Nuclear Information System (INIS)

McMackin, M.R.

1993-01-01

A plausible combination of geologic factors leading to failure can be hypothesized for the Yucca Mountain Nuclear Waste Repository. The scenarios is constructed using elementary fault mechanics combined with geologic observations of exhumed faults and published information describing the repository site. The proposed repository site is located in the Basin and Range Province, a region of active crustal deformation demonstrated by widespread seismicity. The Yucca Mountain area has been characterized as tectonically quiet, which in the context of active crustal deformation may indicate the accumulation of the stresses approaching the levels required for fault slip, essentially stick-slip faulting. Simultaneously, dissolution of carbonate rocks in underlying karst aquifers is lowering the bulk strength of the rock that supports the repository site. Rising levels of hydrostatic stress concurrent with a climatically-driven rise in the water table could trigger faulting by decreasing the effective normal stress that currently retards fault slip. Water expelled from collapsing caverns in the underlying carbonate aquifer could migrate upward with sufficient pressure to open existing fractures or create new fractures by hydrofracturing. Water migrating through fractures could reach the repository in sufficient volume to react with heated rock and waste perhaps creating steam explosions that would further enhance fracture permeability. Closure of conduits in the underlying carbonate aquifer could lead to the elevation of the saturated zone above the level of the repository resulting in sustained saturation of radioactive waste in the repository and contamination of through-flowing groundwater

Analysis of spent fuel performance in a geologic repository

International Nuclear Information System (INIS)

Apted, M.J.; Liebetrau, A.M.; Engel, D.W.; Alexander, D.H.

1986-04-01

The Analytical REpository Source-Term (AREST) code developed for the US Department of Energy is being used to assess the time-dependent release rate of radionuclides from spent nuclear fuel disposed in geologic repositories. The Waste Package Release (WPR) submodule of AREST calculates the release from individual waste packages containing spent fuel based on site-specific design, solubility, corrosion, sorption, and mass transfer data. Under the open system conditions of a repository, there are two limiting release mechanisms: surface reaction control and transport control. In addition, a separate release case is defined for soluble radionuclides that are inventory limited. Mass transfer equations for each of these processes are incorporated into AREST. Four separate sources are identified in the AREST code based on inventory and release mechanism: UO 2 matrix (transport limited), gap (inventory limited), grain boundary (inventory limited, combined with gap), and cladding (transport limited). The calculated release of nuclides contained in the matrix (> 90% of the entire inventory) is controlled by UO 2 solubility or the solubility of a nuclide-bearing phase, whichever is lower

Proposal for geological site selection for L/ILW and HLW repositories. Statement of requirements, procedure and results. Technical report 08-03

International Nuclear Information System (INIS)

2008-10-01

Important steps in the process of managing radioactive wastes have already been implemented in Switzerland. These include the handing and packaging of the waste, waste characterisation and documentation of waste inventories and interim storage along with associated transport. In terms of preparing for deep geological disposal, the necessary scientific and technical work is well advanced and the feasibility of constructing geological repositories that provide the required long-term safety has been successfully demonstrated for all waste types arising in Switzerland. Sufficient knowledge is available to allow the next steps in the selection of repository sites to be defined. The legal framework is also in place and organisational measures have been provided that will allow the tasks to be performed in the coming years to be implemented efficiently. The selection of geological siting regions and sites for repositories in Switzerland will be conducted in three stages. Stage 1 ends with the definition of geological siting regions within which the repository projects will be elaborated in more detail in stages 2 and 3. This report documents and justifies the siting proposals prepared by Nagra for the repositories for low- and intermediate-level waste (L/ILW) and high-level waste (HLW). Formulation of these proposals is conducted in five steps: 1) The waste inventory, which includes reserves for future developments, is allocated to the L/ILW and HLW repositories; 2) Based on this waste allocation, the second step involves defining the barrier and safety concepts for the two repositories. With a view to evaluating the geological siting possibilities, quantitative and qualitative guidelines and requirements on the geology are derived on the basis of these concepts. These relate to the time period to be considered, the space requirements for the repository, the properties of the host rock (depth, thickness, lateral extent, hydraulic conductivity), long-term stability

Impact of advanced fuel cycles on uncertainty associated with geologic repositories

International Nuclear Information System (INIS)

Rechard, Rob P.; Lee, Joon; Sutton, Mark; Greenberg, Harris R.; Robinson, Bruce A.; Nutt, W. Mark

2013-01-01

This paper provides a qualitative evaluation of the impact of advanced fuel cycles, particularly partition and transmutation of actinides, on the uncertainty associated with geologic disposal. Based on the discussion, advanced fuel cycles, will not materially alter (1) the repository performance (2) the spread in dose results around the mean (3) the modeling effort to include significant features, events, and processes in the performance assessment, or (4) the characterization of uncertainty associated with a geologic disposal system in the regulatory environment of the United States. (authors)

Applicability of risk-informed criticality methodology to spent fuel repositories

International Nuclear Information System (INIS)

Mays, C.; Thomas, D.A.; Favet, D.

2000-01-01

An important objective of geologic disposal is keeping the fissionable material in a condition so that a self-sustaining nuclear chain reaction (criticality) is highly unlikely. This objective supports the overall performance objective of any repository, which is to protect the health and safety of the public by limiting radiological exposure. This paper describes a risk-informed, performance-based methodology, which combines deterministic and probabilistic approaches for evaluating the criticality potential of high-level waste and spent nuclear fuel after the repository is sealed and permanently closed (postclosure). (authors)

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

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

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.

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.

Industrial complementarities between interim storage and reversible geological repository - 59237

International Nuclear Information System (INIS)

Hoorelbeke, Jean-Michel

2012-01-01

The French Act voted in 2006 made the choice of deep geological disposal as the reference option for the long term management of high level (HLW) and intermediate level long-lived waste. The CIGEO repository project aims at avoiding or limiting burden to future generations, which could not be achieved by the extension in time of interim storage. The reversibility as provided by the Act will maintain a liberty of choice for waste management on a duration which is comparable to new storage facility. Interim storage is required to accommodate waste as long as the repository is not available. The commissioning of the repository in 2025 will not suppress needs for interim storage. The paper describes the complementarities between existing and future interim storage facilities and the repository project: repository operational issues and planning, HLW thermal decay, support for the reversibility, etc. It shows opportunities to prepare a global optimization of waste management including the utilization at best of storage capacities and the planning of waste emplacement in the repository in such a way to facilitate operational conditions and to limit cost. Preliminary simulations of storage-disposal scenarios are presented. Thanks to an optimal use of the waste management system, provision can be made for a progressive increase of waste emplacement flow during the first operation phase of the repository. It is then possible to stabilize the industrial activity level of the repository site. An optimal utilization of interim storage can also limit the diversity of waste packages emplaced simultaneously, which facilitates the operation of the repository. 60 years minimum interim storage duration is generally required with respect to HLW thermal output. Extending this interim storage period may reduce the underground footprint of the repository. Regarding reversibility, the capability to manage waste packages potentially retrieved from the repository should be analyzed. The

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

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

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)

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

Nuclear waste management and implication for geological disposals in South Korea

Energy Technology Data Exchange (ETDEWEB)

Woo, Tae Ho; Chang, Kyung Bae [The Cyber Univ. of Korea, Seoul (Korea, Republic of). Dept. of Mechanical and Control Engineering

2017-10-15

The master plan of permanent nuclear waste repository had been published in South Korea. The high-level nuclear waste repository should be available in 2053. In this study, six possible nuclear waste forms are simulated by Helium ions. The geological repository is comparative easy and cheap considering the international nuclear act of the nuclear nonproliferation treaty (NPT). How ever, there could be some new technologies of the nuclear waste treatment like the pyroprocessing. Transmutation is another option, which is very expensive with current technology.

Reference Design Description for a Geologic Repository

International Nuclear Information System (INIS)

2000-01-01

One of the current major national environmental problems is the safe disposal of large quantities of spent nuclear fuel and high-level radioactive waste materials, which are rapidly accumulating throughout the country. These radioactive byproducts are generated as the result of national defense activities and from the generation of electricity by commercial nuclear power plants. At present, spent nuclear fuel is accumulating at over 70 power plant sites distributed throughout 33 states. The safe disposal of these high-level radioactive materials at a central disposal facility is a high national priority. This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada for the disposal of spent nuclear fuel and high-level radioactive waste materials. This document describes a possible design for the three fundamental parts of a repository: a surface facility, subsurface repository, and waste packaging. It also presents the current conceptual design of the key engineering systems for the final four phases of repository processes: operations, monitoring, closure, and postclosure. In accordance with current law, this design does not include an interim storage option. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. It describes the natural barrier system which, together with the engineered systems, achieves the repository objectives. This design will protect the public and the environment by allowing the safe disposal of radioactive waste received from government-owned custodial spent fuel sites, high-level radioactive waste sites, and commercial power reactor sites. All design elements meet or exceed applicable regulations governing the disposal of high-level radioactive waste. The design will provide safe disposal of waste materials for at least a 10,000 year period. During this time interval, natural radioactive decay

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)

Parameters and criteria influencing the selection of waste emplacement configurations in mined geologic repositories

International Nuclear Information System (INIS)

Bechthold, W.; Closs, K.D.; Papp, R.

1988-01-01

Reference concepts for repositories in deep geological formations have been developed in several countries. For these concepts, emplacement configurations vary within a wide range that comprises drift emplacement of unshielded or self-shielded packages and horizontal or vertical borehole emplacement. This is caused by different parameters, criteria, and criteria weighting factors. Examples for parameters are the country's nuclear power program and waste management policy, its geological situation, and safety requirements, examples for criteria and repository area requirements, expenditures of mining and drilling, and efforts for emplacement and, if required, retrieval. Due to the variety of these factors and their ranking in different countries, requirements for a safe, dependable and cost-effective disposal of radioactive waste can be met in various ways

Siting of repositories for high level nuclear waste geological and institutional issues

International Nuclear Information System (INIS)

Ahagen, H.

1993-01-01

Two studies have been conducted in Sweden under contract from SKN-National Board for Spent Nuclear Fuel. The responsibilities of SKN has been transferred to SKI as of July 1, 1992. The first study is related to a compilation of experience and lessons learned from siting of nuclear waste repositories and other controversial facilities in seven countries. The second study is aimed at compiling examples of the state of knowledge related to the regional geological information with relevance to siting of a repository in Sweden. This paper is drawing the general combined conclusions from both these studies. The first study reviewed programs for siting of nuclear and hazardous waste disposal facilities in Canada, Finland, France, Sweden, Switzerland, United Kingdom and USA. The main topics reviewed are related to a/ The use of technical screening, b/ Legal framework and local veto, c/ Public involvement, d/ Interim storage and schedule flexibility, e/ Sequential vs. parallel characterization. The second study focused on the regional geological information available for Sweden and if this information allows for a ''grouping'' of tectonic regions in Sweden with significant differences in history and characteristics. Factors studied as potentially important for siting are bedrock properties, mineralizations, ground water conditions and available volume for a repository. The experience gained from these studies is aimed to be used as background information in the review of the program conducted for the Swedish nuclear utilities by SKB. SKB will according to current plans initiate siting for a repository for spent nuclear fuel in Sweden during 1993. (author). 2 refs

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

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

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.

A Rock Mechanics and Coupled Hydro mechanical Analysis of Geological Repository of High Level Nuclear Waste in Fractured Rocks

International Nuclear Information System (INIS)

Min, Kibok

2011-01-01

This paper introduces a few case studies on fractured hard rock based on geological data from Sweden, Korea is one of a few countries where crystalline rock is the most promising rock formation as a candidate site of geological repository of high level nuclear waste. Despite the progress made in the area of rock mechanics and coupled hydro mechanics, extensive site specific study on multiple candidate sites is essential in order to choose the optimal site. For many countries concerned about the safe isolation of nuclear wastes from the biosphere, disposal in a deep geological formation is considered an attractive option. In geological repository, thermal loading continuously disturbs the repository system in addition to disturbances a recent development in rock mechanics and coupled hydro mechanical study using DFN(Discrete Fracture Network) - DEM(Discrete Element Method) approach mainly applied in hard, crystalline rock containing numerous fracture which are main sources of deformation and groundwater flow

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

Salt repository project closeout status report

International Nuclear Information System (INIS)

1988-06-01

This report provides an overview of the scope and status of the US Department of Energy (DOE's) Salt Repository Project (SRP) at the time when the project was terminated by the Nuclear Waste Policy Amendments Act of 1987. The report reviews the 10-year program of siting a geologic repository for high-level nuclear waste in rock salt formations. Its purpose is to aid persons interested in the information developed during the course of this effort. Each area is briefly described and the major items of information are noted. This report, the three salt Environmental Assessments, and the Site Characterization Plan are the suggested starting points for any search of the literature and information developed by the program participants. Prior to termination, DOE was preparing to characterize three candidate sites for the first mined geologic repository for the permanent disposal of high-level nuclear waste. The sites were in Nevada, a site in volcanic tuff; Texas, a site in bedded salt (halite); and Washington, a site in basalt. These sites, identified by the screening process described in Chapter 3, were selected from the nine potentially acceptable sites shown on Figure I-1. These sites were identified in accordance with provisions of the Nuclear Waste Policy Act of 1982. 196 refs., 21 figs., 11 tabs

A Single Global Small-User Nuclear Repository

International Nuclear Information System (INIS)

Conca, J.L.; Wright, J.

2009-01-01

Global energy partnerships in nuclear power, proposed by France, Russia, U.S. and England, seek to address the proliferation issue by controlling fuel production and nuclear materials, removing the need for each country to develop enrichment, fabrication, recycling or disposal capabilities. Several of the large generator countries such as France, the U.S., Japan, S. Korea, Russia, the U.K., China and India, all have plans for deep geologic repositories because they anticipate sufficient waste over the next century to justify the expense of a repository. However, countries having, or planning, less than five reactors, such as Egypt, Iran, Indonesia, Brazil and about 30 other countries, will not have sufficient waste generation, or a favorable geologic site, to justify the economic and environmental issues of developing their own repository. The Salado salt formation in New Mexico, set aside for nuclear waste disposal within the 16 square-mile area by the Land Withdrawal Act of 1992, is the most optimal geologic formation for the permanent disposal of any nuclear waste and is easily able to host all of the commercial nuclear waste that will be generated in the next thousand years. The U.S. commercial nuclear waste needs presently surpass all others, and will for the foreseeable future. Hosting the relatively small amount of waste from these small-user nations will add little to U.S. waste stream while the cost/benefit analysis from the standpoint of operations, safety, geology, cost and proliferation is overwhelmingly positive for developing such a global repository. Oceanic and overland transportation, high-level disposal logistics and costs from several programs, including WIPP, have demonstrated that the operation would pay for itself from international user fees with no U.S. taxpayer dollars required and still save the world about $400 billion over 100 years. The ethical considerations alone are compelling. (authors)

MONITORED GEOLOGIC REPOSITORY LIFE CYCLE COST ESTIMATE ASSUMPTIONS DOCUMENT

International Nuclear Information System (INIS)

R.E. Sweeney

2001-01-01

The purpose of this assumptions document is to provide general scope, strategy, technical basis, schedule and cost assumptions for the Monitored Geologic Repository (MGR) life cycle cost (LCC) estimate and schedule update incorporating information from the Viability Assessment (VA) , License Application Design Selection (LADS), 1999 Update to the Total System Life Cycle Cost (TSLCC) estimate and from other related and updated information. This document is intended to generally follow the assumptions outlined in the previous MGR cost estimates and as further prescribed by DOE guidance

Monitored Geologic Repository Life Cycle Cost Estimate Assumptions Document

International Nuclear Information System (INIS)

Sweeney, R.

2000-01-01

The purpose of this assumptions document is to provide general scope, strategy, technical basis, schedule and cost assumptions for the Monitored Geologic Repository (MGR) life cycle cost estimate and schedule update incorporating information from the Viability Assessment (VA), License Application Design Selection (LADS), 1999 Update to the Total System Life Cycle Cost (TSLCC) estimate and from other related and updated information. This document is intended to generally follow the assumptions outlined in the previous MGR cost estimates and as further prescribed by DOE guidance

Life cycle assessment of geological repositories for the final disposal of spent fuel in Finland and Sweden

International Nuclear Information System (INIS)

Puhrer, A.; Bauer, C.

2014-01-01

This paper presents a Life Cycle Assessment (LCA) of the geological repositories for the final disposal of spent nuclear fuel in Finland and Sweden. A separate LCA has been performed for the geological spent fuel repository in each country and the results have been compared. A further benchmark comparison has been made with the LCA of the Swiss geological repository for high-level waste and spent fuel. The life cycle inventory (LCI) product system boundaries include the spent fuel repository and encapsulation facility in each country. All materials, processes, consumed utilities and transport associated with the construction, operation and closure of the repositories for spent fuel are included in the LCI. The life cycle impact assessment (LCIA) is performed using two methods: IPCC 2007 Climate Change and ReCiPe. These assessment methods return results pertaining to global warming potential (GWP) as well as a number of environmental impact categories such as human toxicity and natural land transformation. Results indicate that the use of copper for disposal canister fabrication and bentonite for repository backfilling are the causes for most of the environmental impact of the spent fuel repositories in Finland and Sweden. Alternate, less bentonite-intensive backfilling scenarios may mitigate this impact. While the Swiss bentonite consumption is lower and no copper is used for canister fabrication, the Swiss electricity and fuel consumption associated with final disposal of high-level waste and spent fuel is significantly higher than in Finland or Sweden. Approximately 1 g CO 2 -eq is emitted due to the final disposal of spent fuel and HLW per kWh of nuclear generated electricity. This represents some 10% of the emissions due to the entire nuclear energy chain and is practically negligible in the context of GHG emissions of other energy technologies. (authors)

Evaluation of geologic and geophysical techniques for surface-to-subsurface projections of geologic characteristics in crystalline rock

International Nuclear Information System (INIS)

1985-07-01

Granitic and gneissic rock complexes are being considered for their potential to contain and permanently isolate high-level nuclear waste in a deep geologic repository. The use of surface geologic and geophysical techniques has several advantages over drilling and testing methods for geologic site characterization in that the techniques are typically less costly, provide data over a wider area, and do not jeopardize the physical integrity of a potential repository. For this reason, an extensive literature review was conducted to identify appropriate surface geologic and geophysical techniques that can be used to characterize geologic conditions in crystalline rock at proposed repository depths of 460 to 1,220 m. Characterization parameters such as rock quality; fracture orientation, spacing; and aperture; depths to anomalies; degree of saturation; rock body dimensions; and petrology are considered to be of primary importance. Techniques reviewed include remote sensing, geologic mapping, petrographic analysis, structural analysis, gravity and magnetic methods, electrical methods, and seismic methods. Each technique was reviewed with regard to its theoretical basis and field application; geologic parameters that can be evaluated; advantages and limitations, and, where available, case history applications in crystalline rock. Available information indicates that individual techniques provide reliable information on characteristics at the surface, but have limited success in projections to depths greater that approximately 100 m. A combination of integrated techniques combines with data from a limited number of boreholes would significantly improve the reliability and confidence of early characterization studies to provide qualitative rock body characteristics for region-to-area and area-to-site selection evaluations. 458 refs., 32 figs., 14 tabs

Muon Tomography for Geological Repositories.

Science.gov (United States)

Woodward, D.; Kudryavtsev, V.; Gluyas, J.; Clark, S. J.; Thompson, L. F.; Klinger, J.; Spooner, N. J.; Blackwell, T. B.; Pal, S.; Lincoln, D. L.; Paling, S. M.; Mitchell, C. N.; Benton, C.; Coleman, M. L.; Telfer, S.; Cole, A.; Nolan, S.; Chadwick, P.

2015-12-01

Cosmic-ray muons are subatomic particles produced in the upper atmosphere in collisions of primary cosmic rays with atoms in air. Due to their high penetrating power these muons can be used to image the content (primarily density) of matter they pass through. They have already been used to image the structure of pyramids, volcanoes and other objects. Their applications can be extended to investigating the structure of, and monitoring changes in geological formations and repositories, in particular deep subsurface sites with stored CO2. Current methods of monitoring subsurface CO2, such as repeat seismic surveys, are episodic and require highly skilled personnel to operate. Our simulations based on simplified models have previously shown that muon tomography could be used to continuously monitor CO2 injection and migration and complement existing technologies. Here we present a simulation of the monitoring of CO2 plume evolution in a geological reservoir using muon tomography. The stratigraphy in the vicinity of the reservoir is modelled using geological data, and a numerical fluid flow model is used to describe the time evolution of the CO2 plume. A planar detection region with a surface area of 1000 m2 is considered, at a vertical depth of 776 m below the seabed. We find that one year of constant CO2 injection leads to changes in the column density of about 1%, and that the CO2 plume is already resolvable with an exposure time of less than 50 days. The attached figure show a map of CO2 plume in angular coordinates as reconstructed from observed muons. In parallel with simulation efforts, a small prototype muon detector has been designed, built and tested in a deep subsurface laboratory. Initial calibrations of the detector have shown that it can reach the required angular resolution for muon detection. Stable operation in a small borehole within a few months has been demonstrated.

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

Development of Spherical Near Field Model for Geological Radioactive Waste Repository

International Nuclear Information System (INIS)

Kim, S. Y.; Lee, K. J.; Chang, S. H.; Lee, K. J.; Chang, S. H.

2012-01-01

Modeling for geological radioactive waste repository can be divided into 3 parts. They are near field modeling related to engineered barrier, far field modeling related to natural barrier and biosphere modeling. In order to make the general application for safety assessment of geological waste repository, spherical geometry near field model has been developed. This model can be used quite extensively when users calculate equivalent spherical geometry for specific engineered barrier like equivalent waste radius, equivalent barrier radius and etc. Only diffusion was considered for general purpose but advection part can be updated. Goldsim and Goldsim Radionuclide Transport (RT) module were chosen and used as developing tool for the flexible modeling. Developer can freely make their own model with developer friendly graphic interface by using Goldsim. Furthermore, model with user friendly graphic interface can be developed by using Goldsim Dashboard Authoring module. The model has been validated by comparing the result with that of another model, inserting similar inputs and conditions. The model has been proved to be reasonably operating from the comparison result by validation process. Cylindrical model can be developed as a further work based on the knowledge and experience from this research

Development of Spherical Near Field Model for Geological Radioactive Waste Repository

Energy Technology Data Exchange (ETDEWEB)

Kim, S. Y.; Lee, K. J.; Chang, S. H. [Korea Advanced Institute of Science and Technology, Daejeon (Korea, Republic of); Lee, K. J.; Chang, S. H. [Khalifa Univ. of Science/Technology and Research, Abu Dhabi (United Arab Emirates)

2012-03-15

Modeling for geological radioactive waste repository can be divided into 3 parts. They are near field modeling related to engineered barrier, far field modeling related to natural barrier and biosphere modeling. In order to make the general application for safety assessment of geological waste repository, spherical geometry near field model has been developed. This model can be used quite extensively when users calculate equivalent spherical geometry for specific engineered barrier like equivalent waste radius, equivalent barrier radius and etc. Only diffusion was considered for general purpose but advection part can be updated. Goldsim and Goldsim Radionuclide Transport (RT) module were chosen and used as developing tool for the flexible modeling. Developer can freely make their own model with developer friendly graphic interface by using Goldsim. Furthermore, model with user friendly graphic interface can be developed by using Goldsim Dashboard Authoring module. The model has been validated by comparing the result with that of another model, inserting similar inputs and conditions. The model has been proved to be reasonably operating from the comparison result by validation process. Cylindrical model can be developed as a further work based on the knowledge and experience from this research.

Repository waste-handling operations, 1998

International Nuclear Information System (INIS)

Cottam, A.E.; Connell, L.

1986-04-01

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

NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

Energy Technology Data Exchange (ETDEWEB)

None

1982-07-01

This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules.

NWTS program criteria for mined geologic disposal of nuclear waste: repository performance and development criteria. Public draft

International Nuclear Information System (INIS)

1982-07-01

This document, DOE/NWTS-33(3) is one of a series of documents to establish the National Waste Terminal Storage (NWTS) program criteria for mined geologic disposal of high-level radioactive waste. For both repository performance and repository development it delineates the criteria for design performance, radiological safety, mining safety, long-term containment and isolation, operations, and decommissioning. The US Department of Energy will use these criteria to guide the development of repositories to assist in achieving performance and will reevaluate their use when the US Nuclear Regulatory Commission issues radioactive waste repository rules

Designing shafts for handling high-level radioactive wastes in mined geologic repositories

International Nuclear Information System (INIS)

Hambley, D.F.; Morris, J.R.

1988-01-01

Waste package conceptual designs developed in the United States by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management are the basis for specifying the dimensions and weights of the waste package and transfer cask combinations to be hoisted in the waste handling shafts in mined geologic repositories for high-level radioactive waste. The hoist, conveyance, counterweight, and hoist ropes are then sized. Also taken into consideration are overwind and underwind arrestors and safety features required by the U.S. Nuclear Regulatory Commission. Other design features such as braking systems, chairing system design, and hoisting speed are considered in specifying waste hoisting system parameters for example repository sites

Office of Geologic Repositories program baseline procedures notebook (OGR/B-1)

International Nuclear Information System (INIS)

1986-06-01

Baseline management is typically applied to aid in the internal control of a program by providing consistent programmatic direction, control, and surveillance to an evolving system development. This fundamental concept of internal program control involves the establishment of a baseline to serve as a point of departure for consistent technical program coordination and to control subsequent changes from that baseline. The existence of a program-authorized baseline ensures that all participants are working to the same ground rules. Baseline management also ensures that, once the baseline is defined, changes are assessed and approved by a process which ensures adequate consideration of overall program impact. Baseline management also includes the consideration of examptions from the baseline. The process of baseline management continues through all the phases of an evolving system development program. As the Program proceeds, there will be a progressive increase in the data contained in the baseline documentation. Baseline management has been selected as a management technique to aid in the internal control of the Office of Geologic Repositories (OGR) program. Specifically, an OGR Program Baseline, including technical and programmatic requirements, is used for program control of the four Mined Geologic Disposal System field projects, i.e., Basalt Waste Isolation Project, Nevada Nuclear Waste Storage Investigation, Salt Repository Project and Crystalline Repository Project. This OGR Program Baseline Procedures Notebook provides a description of the baseline mwanagement concept, establishes the OGR Program baseline itself, and provides procedures to be followed for controlling changes to that baseline. The notebook has a controlled distribution and will be updated as required

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

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

International Nuclear Information System (INIS)

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

1978-01-01

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

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

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

The role of natural analogs in the repository licensing process

International Nuclear Information System (INIS)

Murphy, W.M.

1995-01-01

The concept of a permanent geologic repository for high-level nuclear waste (NLW) is implicitly based on analogy to natural systems that have been stable for millions or billions of years. The time of radioactive and chemical toxicity of HLW exceeds the duration of human civilization, and it is impossible to demonstrate the accuracy of predictions of the behavior of engineered or social systems over such long periods

U.S. Department of Energy approaches to the assessment of radionuclide migration for the geologic repository program

International Nuclear Information System (INIS)

Luik, A.E. van; Apted, M.J.

1988-01-01

Potential radionuclide migration in geologic repositories is being addressed by the U.S. Department of Energy's Office of Civilian Radioactive Waste Management through its Office of Geologic Repositories (OGR). A diversity of geohydrologic settings is being investigated: unsaturated tuff, saturated basalt, and bedded salt. A number of approaches to assessing potential migration are being considered. Mass transfer is prominent among near-field approaches. For far-field analysis of migration in the geosphere, detailed characterizations of potential repository sites will lead to site-specific models describing radionuclide migration for a variety of postulated release scenarios. Finite-element and finite-difference codes are being used and developed to solve the mathematical equations pertinent to far-field assessments. Computational approaches presently in use generally require distribution coefficients to estimate the retardation of specific radionuclides with respect to the transport rate of water. 26 refs

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)

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

Initial results from dissolution rate testing of N-Reactor spent fuel over a range of potential geologic repository aqueous conditions

International Nuclear Information System (INIS)

Gray, W.J.; Einziger, R.E.

1998-04-01

Hanford N-Reactor spent nuclear fuel (HSNF) may ultimately be placed in a geologic repository for permanent disposal. To determine whether the engineered barrier system that will be designed for emplacement of light-water-reactor (LWR) spent fuel will also suffice for HSNF, aqueous dissolution rate measurements were conducted on the HSNF. The purpose of these tests was to determine whether HSNF dissolves faster or slower than LWR spent fuel under some limited repository-relevant water chemistry conditions. The tests were conducted using a flowthrough method that allows the dissolution rate of the uranium matrix to be measured without interference by secondary precipitation reactions that would confuse interpretation of the results. Similar tests had been conducted earlier with LWR spent fuel, thereby allowing direct comparisons. Two distinct corrosion modes were observed during the course of these 12 tests. The first, Stage 1, involved no visible corrosion of the test specimen and produced no undissolved corrosion products. The second, Stage 2, resulted in both visible corrosion of the test specimen and left behind undissolved corrosion products. During Stage 1, the rate of dissolution could be readily determined because the dissolved uranium and associated fission products remained in solution where they could be quantitatively analyzed. The measured rates were much faster than has been observed for LWR spent fuel under all conditions tested to date when normalized to the exposed test specimen surface areas. Application of these results to repository conditions, however, requires some comparison of the physical conditions of the different fuels. The surface area of LWR fuel that could potentially be exposed to repository groundwater is estimated to be approximately 100 times greater than HSNF. Therefore, when compared on the basis of mass, which is more relevant to repository conditions, the HSNF and LWR spent fuel dissolve at similar rates

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

Status of technologies related to the isolation of radioactive wastes in geologic repositories

Energy Technology Data Exchange (ETDEWEB)

Irish, E R [International Atomic Energy Agency, Vienna (Austria). Div. of Nuclear Safety and Environmental Protection; Cooley, C R [Department of Energy, Washington, DC (USA). Office of Nuclear Waste Management

1980-09-01

The authors present an overview of the status of technologies relevant to the isolation of radioactive wastes in geologic repositories. In addition to summarizing scientific and technical work on waste forms and packages, the: a) importance of the systems viewpoint, b) importance of modeling, c) need for site-specific investigations, d) consideration of future sub-surface human activities and e) prospects for successful isolation are discussed. It is concluded that successful isolation of radioactive wastes from the biosphere appears technically feasible for periods of thousands of years provided that the systems view is used in repository siting and design.

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.

Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Pacific Coastal and Marine Science Center (PCMSC) Samples Repository

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Pacific Coastal and Marine Science Center (PCMSC) Samples Repository is a partner in the Index...

Establishment of IAEA knowledge of integrity of the geological repository boundaries and disposed spent fuel assemblies in the context of the Finnish geological repository. Experts' Group meeting Report on Task JNT/C 1204 of the Member States' Support Programme to IAEA Safeguards

International Nuclear Information System (INIS)

Okko, O.

2004-05-01

The Geological Repository Safeguards Experts Group (Member State Support Programme tasks JNT/C1204 and C1226), agreed that annual meetings should be held to address interface issues between IAEA safeguards and radioactive waste management and to explore the use of safety and operational information to make International Atomic Energy Agency (IAEA) safeguards more effective and efficient for geological repository facilities. It has also been recognised that the safeguards measures for geological repositories are to be developed site-specifically. To address these issues to the planned Olkiluoto repository in Finland a meeting of experts in safety, geological repository operations,and safeguards from 6 States, European Commission, and IAEA was held in Olkiluoto and Rauma, Finland, during September 29 - October 4, 2003. The pre-operational phase of the Olkiluoto repository should be efficiently used by the parties involved in safeguards. The applicability and reliability of the potential new techniques and the efficient practices must be developed and proven before their implementation as safeguards measures to be applied at the subsequent stages of the repository development. The visit to the location of the proposed Olkiluoto repository and neighbouring areas and subsequent presentations enabled the working groups to discuss the various issues with reference to actual site conditions. The working groups were thus able to identify potential measurement and monitoring techniques and research and development requirements for consideration by the Finnish authorities, in addition to making recommendations to the IAEA on planned activities for carrying out before and during the early investigation phase of the proposed Olkiluoto repository. It was understood that all parties shall take good care of the implementation of the planned activities to ensure that proven means, approaches and the required verified information is at hand at the time the projected facility will

Stability of underground excavations in a repository system

International Nuclear Information System (INIS)

Calash, A.Y.; Greer, J.C.; Andrea, S.J.; Chowdhury, A.H.; Nguyen, V.V.

1988-01-01

The DOE is investigating the feasibility of constructing a deep geologic repository at the Hanford Site, Washington, for the permanent disposal of nuclear waste. The underground openings associated with the repository design include shafts, tunnels, emplacement rooms and boreholes. The stability of these underground openings, the extent and characteristics of the disturbed zones due to excavation, and their effects on groundwater flow path and travel time have a primary influence on the performance assessment of the Hanford Site as a nuclear waste repository. This study is being done in accordance with the requirements of the NRC. Results of structural analyses of shafts and tunnels under in situ stresses and/or medium weight are presented in this paper. Four different analyses were carried out to analyze the shaft: a plane strain model, axisymmetric model, 3-D model of a single material medium, and 3-D model of a three material medium

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 10. Repository preconceptual design studies: granite

International Nuclear Information System (INIS)

1978-04-01

This volume, Volume 10 ''Repository Preconceptual Design Studies: Granite,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This document describes a preconceptual design for a nuclear waste storage facility in granite. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area, and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/11, ''Drawings for Repository Preconceptual Design Studies: Granite.''

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 8. Repository preconceptual design studies: salt

International Nuclear Information System (INIS)

1978-04-01

This volume, Volume 8 ''Repository Preconceptual Design Studies: Salt,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This document describes a preconceptual design for a nuclear waste storage facility in salt. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area, and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/9, ''Drawings for Repository Preconceptual Design Studies: Salt.''

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

Salt repository project: Technical progress report for the quarter 1 April--30 June 1987

International Nuclear Information System (INIS)

1987-01-01

This document reports the progress being made each quarter on the development of a geologic repository in salt for the permanent disposal of high-level nuclear waste. The reporting elements are arranged by the work breakdown structure so that related studies are presented together. The studies are reported by the Office of Nuclear Waste Isolation, a prime contractor of the US Department of Energy (DOE) Salt Repository Project Office. The studies include work by other DOE prime contractors and by contractors to the Office of Nuclear Waste Isolation

Salt Repository Project technical progress report for the quarter 1 January--31 March 1987

International Nuclear Information System (INIS)

1988-03-01

This document reports the progress being made each quarter on the development of a geologic repository in salt for the permanent disposal of high-level nuclear waste. The reporting elements are arranged by the work breakdown structure so that related studies are presented together. The studies are reported by the Office of Nuclear Waste Isolation, a prime contractor of the US Department of energy (DOE) Salt Repository Project Office. The studies include work by other DOE prime contractors and by contractors to the Office of Nuclear Waste Isolation. 23 refs., 1 fig

The application of geological computer modelling systems to the characterisation and assessment of radioactive waste repositories

International Nuclear Information System (INIS)

White, M.J.; Del Olmo, C.

1996-01-01

The deep disposal of radioactive waste requires the collection and analysis of large amounts of geological data. These data give information on the geological and hydrogeological setting of repositories and research sites, including the geological structure and the nature of the groundwater. The collection of these data is required in order to develop an understanding of the geology and the geological evolution of sites and to provide quantitative information for performance assessments. An integrated approach to the interpretation and provision of these data is proposed in this paper, via the use of computer systems, here termed geological modelling systems. Geological modelling systems are families of software programmes which allow the incorporation of site investigation data into integrated 3D models of sub-surface geology

Geologic software for nuclear waste repository studies: A quality assurance program

International Nuclear Information System (INIS)

Figuli, S.; English, S.L.

1987-04-01

This paper discusses a Quality Assurance (QA) program that Kent State University (KSU) has implemented for the development of geologic software. The software being developed at KSU will be used in the site characterization of nuclear waste repositories and must meet the requirements of federal regulations. This QA program addresses the development of models that will be used in the evaluation of the long-term climatic stability of three sites in the western US

Problems of geologic survey of high level radioactive waste repositories illustrated on the testing site in the Melechov Massif

International Nuclear Information System (INIS)

Mlcoch, B.

1997-01-01

Major attention is paid to problems associated with the geologic maps of the prospective repository site, which lies within the Bohemian Massif. Structural geology, survey through boreholes, and primary database are also discussed briefly. (P.A.)

Geology of the Yucca Mountain Region, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste

International Nuclear Information System (INIS)

J.S. Stuckless; D. O'Leary

2006-01-01

Yucca Mountain has been proposed as the site for the Nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began about 10 Ma and continued as recently as about 80 ka with the eruption of cones and flows at Lathrop Wells, approximately 10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain

Key radionuclides and parameters that determine performance of geologic repositories for high-level radioactive wastes

International Nuclear Information System (INIS)

Joonhong Ahn; Atsuyuki Suzuki

1993-01-01

This paper presents results of a mathematical analysis for performance of the engineered barriers of high-level radioactive waste repositories. The main body of the mathematical model developed in this study is mass transport of actinides in a bentonite region. In an analysis of actinide transport, radioactive decay chain and effects of low solubilities must be taken into account. In many previous models for mass transport in engineered barriers including radioactive decay chain, however, boundary conditions at the interface between the waste form and the bentonite region cannot be determined flexibly. In some models, solubility-limited boundary condition is assumed for all the members in a chain. In order to investigate what are key radionuclides and parameters that control performance of engineered barriers of a geologic repository, we must evaluate mass transport with the source boundary condition determined by a detailed analysis on mass transfer at the boundary. In this study, we developed a mathematical model, which can determine whether the inner boundary condition is solubility-limited or congruent release, based on a mathematical analysis for mass transfer at the glass dissolution location, and how long the solubility-limited boundary condition applies. Based on the mathematical model, we point out radionuclides and parameters that have primary influences on the performance of a repository, and investigate a reasonable strategy for coupling geologic disposal and partitioning of those key radionuclides from the standpoint of reducing hazard of geologic disposal. (authors). 4 tabs., 2 figs., 8 refs

Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) Woods Hole Coastal and Marine Science Center (WHCMSC) Samples Repository is a partner in the...

Archive of Geosample Data and Information from the U.S. Geological Survey (USGS) Coastal and Marine Geology Program (CMGP) St. Petersburg Coastal and Marine Science Center (SPCMSC) Samples Repository

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The U.S. Geological Survey Coastal and Marine Geology Program (CMGP) St. Petersburg Coastal and Marine Science Center (SPCMSC) Samples Repository is a partner in the...

Analysis on the use of engineered barriers for geologic isolation of spent fuel in a reference salt site repository

International Nuclear Information System (INIS)

Cloninger, M.O.; Cole, C.R.; Washburn, J.F.

1980-12-01

A perspective on the potential durability and effectiveness requirements for the waste form, container and other engineered barriers for geologic disposal of spent nuclear fuel has been developed. This perspective is based on calculated potential doses to individuals who may be exposed to radioactivity released from a repository via a groundwater transport pathway. These potential dose commitments were calculated with an integrated geosphere transport and bioshpere transport model. A sensitivity analysis was accomplished by varying four important system parameters, namely the waste radionuclide release rate from the repository, the delay prior to groundwater contact with the waste (leach initiation), aquifer flow velocity and flow path length. The nuclide retarding capacity of the geologic media, a major determinant of the isolation effectiveness, was not varied as a parameter but was held constant for a particular reference site. This analysis is limited to looking only at engineered barriers whose net effect is either to delay groundwater contact with the waste form or to limit the rate of release of radionuclides into the groundwater once contact has occurred. The analysis considers only leach incident scenarios, including a water well intrusion into the groundwater near a repository, but does not consider other human intrusion events or catastrophic events. The analysis has so far been applied to a reference salt site repository system and conclusions are presented.Basically, in nearly all cases, the regional geology is the most effective barrier to release of radionuclides to the biosphere; however, for long-lived isotopes of carbon, technetium and iodine, which were poorly sorbed on the geologic media, the geology is not very effective once a leach incident is initiated

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

Standard guide for characterization of spent nuclear fuel in support of geologic repository disposal

CERN Document Server

American Society for Testing and Materials. Philadelphia

2009-01-01

1.1 This guide provides guidance for the types and extent of testing that would be involved in characterizing the physical and chemical nature of spent nuclear fuel (SNF) in support of its interim storage, transport, and disposal in a geologic repository. This guide applies primarily to commercial light water reactor (LWR) spent fuel and spent fuel from weapons production, although the individual tests/analyses may be used as applicable to other spent fuels such as those from research and test reactors. The testing is designed to provide information that supports the design, safety analysis, and performance assessment of a geologic repository for the ultimate disposal of the SNF. 1.2 The testing described includes characterization of such physical attributes as physical appearance, weight, density, shape/geometry, degree, and type of SNF cladding damage. The testing described also includes the measurement/examination of such chemical attributes as radionuclide content, microstructure, and corrosion product c...

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

Geologic repositories for radioactive waste: the nuclear regulatory commission geologic comments on the environmental assessment

International Nuclear Information System (INIS)

Justus, P.S.; Trapp, J.S.; Westbrook, K.B.; Lee, R.; Blackford, M.B.; Rice, B.

1985-01-01

The NRC staff completed its review of the Environmental Assessments (EAs) issued by the Department of Energy (DOE) in December, 1984, in support of the site selection processes established by the Nuclear Waste Policy Act of 1982 (NWPA). The EAs contain geologic information on nine sites that DOE has identified as potentially acceptable for the first geologic repository in accordance with the requirements of NWPA. The media for the sites vary from basalt at Hanford, Washington, tuff at Yucca Mountain, Nevada, bedded salt in the Palo Duro Basin, Texas and Paradox Basin, Utah, to salt domes in Mississippi and Louisiana. Despite the diversity in media there are common areas of concern for all sites. These include; structural framework and pattern, rates of tectonic and seismic activity, characterization of subsurface features, and stratigraphic thickness, continuity and homogeneity. Site-specific geologic concerns include: potential volcanic and hydrothermal activity at Yucca Mountain, potential hydrocarbon targets and deep basalt and sub-basalt structure at Hanford, and potential dissolution at all salt sites. The NRC comments were influenced by the performance objectives and siting criteria of 10 CFR Part 60 and the environmental protection criteria in 40 CFR Part 191, the applicable standards proposed by EPA. In its review the NRC identified several areas of geologic concern that it recommended DOE re-examine to determine if alternative or modified conclusions are appropriate

Impact on geologic repository usage from limited actinide recycle in pressurized light water reactors

International Nuclear Information System (INIS)

Wigeland, Roald A.; Bauer, Theodore H.; Hill, Robert N.; Stillman, John A.

2007-01-01

A project has been conducted as part of the U.S. Department of Energy Advanced Fuel Cycle Initiative to evaluate the impact of limited actinide recycling in light water reactors on the utilization of a geologic repository where loading of the repository is constrained by the decay heat of the emplaced materials. In this study, it was assumed that spent PWR fuel was processed, removing the uranium, plutonium, americium, and neptunium, along with the fission products cesium and strontium. Previous work had demonstrated that these elements were responsible for limiting loading in the repository based on thermal constraints. The plutonium, americium, and neptunium were recycled in a PWR, with process waste and spent recycled fuel being sent to the repository. The cesium and strontium were placed in separate storage for 100-300 years to allow for decay prior to disposal. The study examined the effect of single and multiple recycles of the recovered plutonium, americium, and neptunium, as well as different processing delay times. The potential benefit to the repository was measured by the increase in utilization of repository space as indicated by the allowable linear loading in the repository drifts (tunnels). The results showed that limited recycling would provide only a small fraction of the benefit that could be achieved with repeated processing and recycling, as is possible in fast neutron reactors. (author)

Optimization method for dimensioning a geological HLW waste repository

International Nuclear Information System (INIS)

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

1990-01-01

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

Displays for promotion of public understanding of geological repository concept and the spatial scale

International Nuclear Information System (INIS)

Shobu, Nobuhiro; Kashiwazaki, Hiroshi

2003-05-01

Japan Nuclear Cycle Development Institutes (JNC) has a few thousands of short term visitors to Geological Isolation Basic Research Facility of Tokai works in every year. From the viewpoint of promotion of the visitor's understanding and also smooth communication between researchers and visitors, the explanation of the technical information on geological disposal should be carried out in more easily understandable methods, as well as conventional tour to the engineering-scale test facility (ENTRY). This paper reports on the background information and the appearance of displays, which were installed at ENTRY, to promote public understanding of geological repository concept and the spatial scale. They have been practically used as one of the explanation tools to support visitor's understanding. (author)

Geology of the Yucca Mountain Region, Chapter in Stuckless, J.S., ED., Yucca Mountain, Nevada - A Proposed Geologic Repository for High-Level Radioactive Waste

Energy Technology Data Exchange (ETDEWEB)

J.S. Stuckless; D. O' Leary

2006-09-25

Yucca Mountain has been proposed as the site for the Nation's first geologic repository for high-level radioactive waste. This chapter provides the geologic framework for the Yucca Mountain region. The regional geologic units range in age from late Precambrian through Holocene, and these are described briefly. Yucca Mountain is composed dominantly of pyroclastic units that range in age from 11.4 to 15.2 Ma. The proposed repository would be constructed within the Topopah Spring Tuff, which is the lower of two major zoned and welded ash-flow tuffs within the Paintbrush Group. The two welded tuffs are separated by the partly to nonwelded Pah Canyon Tuff and Yucca Mountain Tuff, which together figure prominently in the hydrology of the unsaturated zone. The Quaternary deposits are primarily alluvial sediments with minor basaltic cinder cones and flows. Both have been studied extensively because of their importance in predicting the long-term performance of the proposed repository. Basaltic volcanism began about 10 Ma and continued as recently as about 80 ka with the eruption of cones and flows at Lathrop Wells, approximately 10 km south-southwest of Yucca Mountain. Geologic structure in the Yucca Mountain region is complex. During the latest Paleozoic and Mesozoic, strong compressional forces caused tight folding and thrust faulting. The present regional setting is one of extension, and normal faulting has been active from the Miocene through to the present. There are three major local tectonic domains: (1) Basin and Range, (2) Walker Lane, and (3) Inyo-Mono. Each domain has an effect on the stability of Yucca Mountain.

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

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

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.

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.

Geological boundary conditions for a safety demonstration and verification concept for a HLW repository in claystone in Germany. AnSichT

Energy Technology Data Exchange (ETDEWEB)

Stark, Lena; Bebiolka, Anke; Gerardi, Johannes [Federal Institute for Geosciences and Natural Resources (BGR), Hannover (Germany). Dept. of Underground Space for Storage and Economic Use; and others

2015-07-01

Within the framework of the R and D project ''AnSichT'', DBE TECHNOLOGY, BGR and GRS are developing a method to demonstrate the safety of a HLW repository in claystone in Germany. The methodological approach basing on a holistic concept, links the legal and geologic boundary conditions, the disposal and closure concept, the demonstration of barrier integrity, and the long-term analysis of the repository evolution as well. The geologic boundary conditions are specified by the description of the geological situation and generic models, the selection of representative parameters and geoscientific long-term predictions. They form a fundament for the system analysis.

Robust record preservation system on geological repository

International Nuclear Information System (INIS)

Ohuchi, J.; Torata, S.; Tsuboya, T.

2004-01-01

Long-term record preservation system on geological disposal of High Level Radioactive Wastes (HLW) has been investigated as the institutional control by RWMC, Japan. Geological disposal of HLW, being based on the passive safe concept, has been considered not to necessitate the human controls to maintain its long-term safety. However how to complement the safety case on geological disposal is an important issue in each countries to progress the repository program with the step-wise decisions process during the long-term period up to several hundreds years. Although we cannot predict the future society, we need to realize the robust and redundant system for preserving records, which should be accessible, retrievable and understandable for the unpredicted future generations. First of all, we held a Rome workshop in January 2003 to exchange views on the matter, resulted in the suggestion directing the discussion on the record management and long-term preservation and retrieval of information regarding radioactive waste. Second, we considered the balance of active and passive system to strengthen the robustness. Another significance of long-term record preservation is to send current generation an implicit message, 'doing our best for future generations', in addition to aiming at both warning and their own decision-making. We call it 'meta-signal' to current generation. Thirdly, we demonstrated the laser-engraving technology to have converted five hundreds pages of an A4 sized report with human readable font sizes to 42 square silicon carbide plates, 10cm x10cm and 1mm in thickness. Silicon carbide would be an alternative to paper and might be possible to be an alternative to microfilm utilized as digital recording media. Another case study is the future generations' accessibility to the preserved records. (author)

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.

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.

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

Staff technical position on investigations to identify fault displacement hazards and seismic hazards at a geologic repository

International Nuclear Information System (INIS)

McConnell, K.I.; Blackford, M.E.; Ibrahim, A.K.

1992-07-01

The purpose of this Staff Technical Position (STP) is to provide guidance to the US Department of Energy (DOE) on acceptable geologic repository investigations that can be used to identify fault displacement hazards and seismic hazards. ne staff considers that the approach this STP takes to investigations of fault displacement and seismic phenomena is appropriate for the collection of sufficient data for input to analyses of fault displacement hazards and seismic hazards, both for the preclosure and postclosure performance periods. However, detailed analyses of fault displacement and seismic data, such as those required for comprehensive assessments of repository performance, may identify the need for additional investigations. Section 2.0 of this STP describes the 10 CFR Part 60 requirements that form the basis for investigations to describe fault displacement hazards and seismic hazards at a geologic repository. Technical position statements and corresponding discussions are presented in Sections 3.0 and 4.0, respectively. Technical position topics in this STP are categorized thusly: (1) investigation considerations, (2) investigations for fault-displacement hazards, and (3) investigations for seismic hazards

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

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

Handling encapsulated spent fuel in a geologic repository environment

International Nuclear Information System (INIS)

Ballou, L.B.

1983-02-01

In support of the Spent Fuel Test-Climate at the U.S. Department of Energy's Nevada Test Site, a spent-fuel canister handling system has been designed, deployed, and operated successfully during the past five years. This system transports encapsulated commercial spent-fuel assemblies between the packaging facility and the test site (approx. 100 km), transfers the canisters 420 m vertically to and from a geologic storage drift, and emplaces or retrieves the canisters from the storage holes in the floor of the drift. The spent-fuel canisters are maintained in a fully shielded configuration at all times during the handling cycle, permitting manned access at any time for response to any abnormal conditions. All normal operations are conducted by remote control, thus assuring as low as reasonably achievable exposures to operators; specifically, we have had no measurable exposure during 30 canister transfer operations. While not intended to be prototypical of repository handling operations, the system embodies a number of concepts, now demonstrated to be safe, reliable, and economical, which may be very useful in evaluating full-scale repository handling alternatives in the future. Among the potentially significant concepts are: Use of an integral shielding plug to minimize radiation streaming at all transfer interfaces. Hydraulically actuated transfer cask jacking and rotation features to reduce excavation headroom requirements. Use of a dedicated small diameter (0.5 m) drilled shaft for transfer between the surface and repository workings. A wire-line hoisting system with positive emergency braking device which travels with the load. Remotely activated grapples - three used in the system - which are insensitive to load orientation. Rail-mounted underground transfer vehicle operated with no personnel underground

Current status of the Japanese geological repository programme

International Nuclear Information System (INIS)

Kitayama, Kazumi

2007-01-01

The programme for disposal of radioactive waste in Japan is now moving ahead on a number of fronts. On the regulatory side, responsibility for TRU waste disposal has been assigned to NUMO and guidelines for the safety goals for disposal of LLW have been published. NUMO, as the implementer for the deep geological disposal programme, has been developing the special tools for project management that are needed as a result of the decision to adopt a volunteering approach to siting. NUMO is also building up the technical infrastructure for flexible tailoring of site characterisation, repository design and the associated safety assessment to the conditions found in any volunteer site. This work requires openness and transparency in decision-making but, as several sites may need to be investigated in parallel, particular emphasis is placed on operational practicality. (author)

Geological criteria for site selection of an LILW radioactive waste repository in the Philippines

International Nuclear Information System (INIS)

Aurelio, Mario; Taguibao, Kristine Joy; Vargas, Edmundo; Palattao, Maria Visitacion; Reyes, Rolando; Nohay, Carl; Singayan, Alfonso

2013-01-01

In the selection of sites for disposal facilities involving low- and intermediate-level radioactive waste (LILW), International Atomic Energy Agency (IAEA) recommendations require that 'the region in which the site is located shall be such that significant tectonic and surface processes are not expected to occur with an intensity that would compromise the required isolation capability of the repository'. Evaluating the appropriateness of a site therefore requires a deep understanding of the geological and tectonic setting of the area. The Philippines sits in a tectonically active region frequented by earthquakes and volcanic activity. Its highly variable morphology coupled with its location along the typhoon corridor in the west Pacific region subjects the country to surface processes often manifested in the form of landslides. The Philippine LILW near surface repository project site is located on the north eastern sector of the Island of Luzon in northern Philippines. This island is surrounded by active subduction trenches; to the east by the East Luzon Trough and to the west by the Manila Trench. The island is also traversed by several branches of the Philippine Fault System. The Philippine LILW repository project is located more than 100 km away from any of these major active fault systems. In the near field, the project site is located less than 10 km from a minor fault (Dummon River Fault) and more than 40 km away from a volcanic edifice (Mt. Caguas). This paper presents an analysis of the potential hazards that these active tectonic features may pose to the project site. The assessment of such geologic hazards is imperative in the characterization of the site and a crucial input in the design and safety assessment of the repository. (authors)

Geological criteria for site selection of an LILW radioactive waste repository in the Philippines

Energy Technology Data Exchange (ETDEWEB)

Aurelio, Mario; Taguibao, Kristine Joy [National Institute of Geological Sciences, University of the Philippines, Quezon City (Philippines); Vargas, Edmundo; Palattao, Maria Visitacion; Reyes, Rolando; Nohay, Carl; Singayan, Alfonso [Philippine Nuclear Research Institute, Department of Science and Technology, Quezon City (Philippines)

2013-07-01

In the selection of sites for disposal facilities involving low- and intermediate-level radioactive waste (LILW), International Atomic Energy Agency (IAEA) recommendations require that 'the region in which the site is located shall be such that significant tectonic and surface processes are not expected to occur with an intensity that would compromise the required isolation capability of the repository'. Evaluating the appropriateness of a site therefore requires a deep understanding of the geological and tectonic setting of the area. The Philippines sits in a tectonically active region frequented by earthquakes and volcanic activity. Its highly variable morphology coupled with its location along the typhoon corridor in the west Pacific region subjects the country to surface processes often manifested in the form of landslides. The Philippine LILW near surface repository project site is located on the north eastern sector of the Island of Luzon in northern Philippines. This island is surrounded by active subduction trenches; to the east by the East Luzon Trough and to the west by the Manila Trench. The island is also traversed by several branches of the Philippine Fault System. The Philippine LILW repository project is located more than 100 km away from any of these major active fault systems. In the near field, the project site is located less than 10 km from a minor fault (Dummon River Fault) and more than 40 km away from a volcanic edifice (Mt. Caguas). This paper presents an analysis of the potential hazards that these active tectonic features may pose to the project site. The assessment of such geologic hazards is imperative in the characterization of the site and a crucial input in the design and safety assessment of the repository. (authors)

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

Groundwater movements around a repository. Geological and geotechnical conditions

International Nuclear Information System (INIS)

Stille, H.; Burgess, A.; Lindblom, U.E.

1977-09-01

The report was prepared as one of a series of technical reports within a study of the groundwater movements around a repository for radioactive waste in the Precambrian bedrock of Sweden. This assessment is intended to provide basic geotechnical data for the analysis. These data include properties and conditions that are representative of the intact rock, the rock mass in general, and the groundwater regime. As there exist a considerable range in the mineralogy of potentially suitable plutonic rocks and since a specific site has not yet been selected, all of the parameters presented in this report must be based on presumptive geological and hydrogeological conditions. Where possible, data for two potential site areas, namely Oskarshamn and Forsmark, are presented. This report is divided into four parts. First, a brief description of the procedure for modelling groundwater movements is presented, along with a tabulation of the important parameters. Secondly, a description of the geological and hydrogeological conditions of the Fennoscandian shield, as well as of the two general site areas, is given. The final two sections of the report provide thermomechanical and geohydrological characteristics and properties of the host rock

The importance of the retrievability of nuclear waste for the implementation of safeguard regimes for geologic repositories

International Nuclear Information System (INIS)

Swahn, J.A.

1999-01-01

To find acceptance for the construction and siting of spent fuel repositories retrievability of the spent fuel is a desired feature. In order to minimize the levels of safeguards needed for the plutonium in spent fuel repositories the retrievability should be as low as possible. These contradictory goals have be balanced against each other during the operational phase, before closure and after closure of the repository. Arguments can be made for having the spent fuel in a highly-retrievable state during the operational phase, in a semi-retrievable state at the end of the operational phase but before closure and in a low-retrievable state after closure. The spent fuel in a mined geologic repository will never be able to be considered irretrievable and surveillance of the repository will be needed for an extended time after closure. The level of safeguards needed will depend on the local, regional and global societal conditions for several hundred thousand years into the future. (author)

Continuous Improvement and the Safety Case for the Waste Isolation Pilot Plant Geologic Repository - 13467

Energy Technology Data Exchange (ETDEWEB)

Van Luik, Abraham; Patterson, Russell; Nelson, Roger [US Department of Energy, Carlsbad Field Office, 4021 S. National parks Highway, Carlsbad, NM 88220 (United States); Leigh, Christi [Sandia National Laboratories Carlsbad Operations, 4100 S. National parks Highway, Carlsbad, NM 88220 (United States)

2013-07-01

The Waste Isolation Pilot Plant (WIPP) is a geologic repository 2150 feet (650 m) below the surface of the Chihuahuan desert near Carlsbad, New Mexico. WIPP permanently disposes of transuranic waste from national defense programs. Every five years, the U.S. Department of Energy (DOE) submits an application to the U.S. Environmental Protection Agency (EPA) to request regulatory-compliance re-certification of the facility for another five years. Every ten years, DOE submits an application to the New Mexico Environment Department (NMED) for the renewal of its hazardous waste disposal permit. The content of the applications made by DOE to the EPA for re-certification, and to the NMED for permit-renewal, reflect any optimization changes made to the facility, with regulatory concurrence if warranted by the nature of the change. DOE points to such changes as evidence for its having taken seriously its 'continuous improvement' operations and management philosophy. Another opportunity for continuous improvement is to look at any delta that may exist between the re-certification and re-permitting cases for system safety and the consensus advice on the nature and content of a safety case as being developed and published by the Nuclear Energy Agency's Integration Group for the Safety Case (IGSC) expert group. DOE at WIPP, with the aid of its Science Advisor and teammate, Sandia National Laboratories, is in the process of discerning what can be done, in a reasonably paced and cost-conscious manner, to continually improve the case for repository safety that is being made to the two primary regulators on a recurring basis. This paper will discuss some aspects of that delta and potential paths forward to addressing them. (authors)

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.)

Andra's geologic repository monitoring strategy

International Nuclear Information System (INIS)

Buschaert, S.; Lesoille, S.; Bertrand, J.; Landais, P.

2012-01-01

Document available in extended abstract form only. After having concluded a feasibility study of deep geological disposal for high-level and long-lived radioactive waste in 2005, Andra was charged by the Planning Act no. 2006-739 to design and create an industrial site for geological disposal called Cigeo which must be reversible for at least a century-long period. The French Safety Guide recommends that Andra develop a monitoring program to be implemented at repository construction and conducted until closure, and possibly after closure, with the aim to confirming prior expectations and enhancing knowledge of relevant processes. This abstract focuses on underground structure monitoring. The monitoring system is based on a combination of in-situ instrumentation and nondestructive methods to obtain the required level of reliable performance. To optimize the device distribution, we take into account both the repetitive design of disposal cells and the homogeneity of the rock properties. This resulted in distinguishing pilot disposal cells that are highly instrumented and standard disposal cells where the instrumentation density could be reduced; monitoring will rely mostly on robotic nondestructive evaluations. If monitoring technologies do not comply with all monitoring objectives, real withdrawal tests of high level wastes in some pilot disposal cells are also planned to provide the possibility of carrying out visual inspection, destructive analyses and samplings on construction materials. Such cells are planned to be dismantled because of the potential disturbance of their component performances from the testing process. Based on this overall strategy, Andra has analyzed the technical requirements that must be met by its monitoring equipment. First, these must be able to provide information on key THMCR (Thermal- Hydraulic-Mechanical-Chemical and Radiological) processes, to provide a three-dimensional image of a disposal component's behavior and thus to understand

Characterizing the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada: hydrology and geochemistry

Science.gov (United States)

Stuckless, John S.; Levich, Robert A.

2012-01-01

This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California, edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description, for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a

Characterizing the proposed geologic repository for high-level radioactive waste at Yucca Mountain, Nevada--hydrology and geochemistry

Science.gov (United States)

Stuckless, John S.; Levich, Robert A.

2012-01-01

This hydrology and geochemistry volume is a companion volume to the 2007 Geological Society of America Memoir 199, The Geology and Climatology of Yucca Mountain and Vicinity, Southern Nevada and California, edited by Stuckless and Levich. The work in both volumes was originally reported in the U.S. Department of Energy regulatory document Yucca Mountain Site Description, for the site characterization study of Yucca Mountain, Nevada, as the proposed U.S. geologic repository for high-level radioactive waste. The selection of Yucca Mountain resulted from a nationwide search and numerous committee studies during a period of more than 40 yr. The waste, largely from commercial nuclear power reactors and the government's nuclear weapons programs, is characterized by intense penetrating radiation and high heat production, and, therefore, it must be isolated from the biosphere for tens of thousands of years. The extensive, unique, and often innovative geoscience investigations conducted at Yucca Mountain for more than 20 yr make it one of the most thoroughly studied geologic features on Earth. The results of these investigations contribute extensive knowledge to the hydrologic and geochemical aspects of radioactive waste disposal in the unsaturated zone. The science, analyses, and interpretations are important not only to Yucca Mountain, but also to the assessment of other sites or alternative processes that may be considered for waste disposal in the future. Groundwater conditions, processes, and geochemistry, especially in combination with the heat from radionuclide decay, are integral to the ability of a repository to isolate waste. Hydrology and geochemistry are discussed here in chapters on unsaturated zone hydrology, saturated zone hydrology, paleohydrology, hydrochemistry, radionuclide transport, and thermally driven coupled processes affecting long-term waste isolation. This introductory chapter reviews some of the reasons for choosing to study Yucca Mountain as a

Preclosure Seismic Design Methodology for a Geologic Repository at Yucca Mountain

International Nuclear Information System (INIS)

K. Coppersmith

2004-01-01

This topical report describes the methodology and criteria that the U.S. Department of Energy (DOE) intends to use for preclosure seismic design of structures, systems, and components (SSCs) that are important to safety (ITS) in the geologic repository operations area. 10 Code of Federal Regulations (CFR) Part 63 [DIRS 156605], states that for a license to be issued for operation of a high-level radioactive waste repository, the U.S. Nuclear Regulatory Commission (NRC) must find that the facility will not constitute an unreasonable risk to the health and safety of the public (Section 63.41[c] [DIRS 156605]). Section 63.21(c)(5) [DIRS 156605] requires that a preclosure safety analysis (PCSA) be performed to ensure that the preclosure performance objectives (Section 63.111 [DIRS 156605]) have been met. The PCSA is a systematic examination of the site, the design, and the potential hazards (Section 63.102[f] [DIRS 156605]), including a comprehensive identification of potential event sequences. Potential naturally-occurring hazards include those event sequences that are initiated by earthquake ground motions or fault displacements due to earthquakes

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

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

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)

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

International Nuclear Information System (INIS)

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

2002-01-01

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

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 16. Repository preconceptual design studies: BPNL waste forms in salt

International Nuclear Information System (INIS)

1978-04-01

This volume, Volume 16, ''Repository Preconceptual Design Studies: BPNL Waste Forms in Salt,'' is one of a 23 volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provide a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This document describes a preconceptual design for a nuclear waste storage facility in salt. The waste forms assumed to arrive at the repository were supplied by Battelle Pacific Northwest Laboratories (BPNL). The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/17, ''Drawings for Repository Preconceptual Design Studies: BPNL Waste Forms in Salt.''

Alternative measure for performance of HLW geologic repository

International Nuclear Information System (INIS)

Joonhang, Ahn; Chambre, P.L.

2001-01-01

A repository performance model that can show effects of canister multiplicity and repository configuration has been developed. Masses of a radionuclide in the repository and in the far field are proposed as performance measures. Canister multiplicity has significant effects on the release of long-lived radionuclides from the repository. As more canisters are included in the same water stream, the radionuclide concentration in the stream increases, but becomes independent of the number of canisters for sufficiently many canisters. Effects of reduction of radionuclide mass in the repository on the repository performance are clearly observed if the canister multiplicity is taken into account and the mass-based measures are applied. (author)

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)

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

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)

State-of-the-art for evaluating the potential impact of flooding on a radioactive waste repository

International Nuclear Information System (INIS)

1980-01-01

This report is a review of the state-of-the-art for evaluating the potential impact of flooding on a deep radioactive-waste repository, namely, for predicting the future occurrence of catastrophic flooding and for estimating the effect of such flooding on waste containment characteristics. Several detrimental effects are identified: flooding can increase groundwater seepage velocities through a repository within the framework of the existing hydrologic system and thus increase the rate of radioactive-waste leakage to the biosphere; flooding may alter repository hydrology by reversing flow gradients, relocating sources of groundwater recharge and discharge, or shortening seepage paths, thereby producing unpredictable leakage; saturation of a vadose-zone repository during flooding can increase groundwater seepage velocities by several orders of magnitude; and flooding can damage repository-media containment properties by inducing seismic or chemical instability or increasing fracture permeability in relatively shallow repository rock as a result of redistributing in-situ stresses. Short-term flooding frequency and magnitude can be predicted statistically by analyzing historical records of flooding. However, long-term flooding events that could damage a permanent repository cannot be predicted with confidence because the geologic record is neither unique nor sufficienly complete for statistical analysis. It is more important to identify parameters characterizing containment properties (such as permeability, groundwater gradient, and shortest seepage path length to the biosphere) that could be affected by future flooding, estimate the maximum magnitude of flooding that could occur within the life of the repository by examining the geologic record, and determine the impact such flooding could have on the parameter values

Considerations of human inturison in U.S. programs for deep geologic disposal of radioactive waste.

Energy Technology Data Exchange (ETDEWEB)

Swift, Peter N.

2013-01-01

Regulations in the United States that govern the permanent disposal of spent nuclear fuel and high-level radioactive waste in deep geologic repositories require the explicit consideration of hypothetical future human intrusions that disrupt the waste. Specific regulatory requirements regarding the consideration of human intrusion differ in the two sets of regulations currently in effect in the United States; one defined by the Environmental Protection Agencys 40 Code of Federal Regulations part 197, applied only to the formerly proposed geologic repository at Yucca Mountain, Nevada, and the other defined by the Environmental Protection Agencys 40 Code of Federal Regulations part 191, applied to the Waste Isolation Pilot Plant in New Mexico and potentially applicable to any repository for spent nuclear fuel and high-level radioactive waste in the United States other than the proposed repository at Yucca Mountain. This report reviews the regulatory requirements relevant to human intrusion and the approaches taken by the Department of Energy to demonstrating compliance with those requirements.

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)

Archive of Geosample Data and Information from the Oregon State University (OSU) College of Earth, Ocean and Atmospheric Sciences (CEOAS) Marine Geology Repository (MGR)

Data.gov (United States)

National Oceanic and Atmospheric Administration, Department of Commerce — The Oregon State University Marine Geology Repository (OSU-MGR) is a partner in the Index to Marine and Lacustrine Geological Samples (IMLGS) database, contributing...

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

Reducing the likelihood of future human activities that could affect geologic high-level waste repositories

International Nuclear Information System (INIS)

1984-05-01

The disposal of radioactive wastes in deep geologic formations provides a means of isolating the waste from people until the radioactivity has decayed to safe levels. However, isolating people from the wastes is a different problem, since we do not know what the future condition of society will be. The Human Interference Task Force was convened by the US Department of Energy to determine whether reasonable means exist (or could be developed) to reduce the likelihood of future human unintentionally intruding on radioactive waste isolation systems. The task force concluded that significant reductions in the likelihood of human interference could be achieved, for perhaps thousands of years into the future, if appropriate steps are taken to communicate the existence of the repository. Consequently, for two years the task force directed most of its study toward the area of long-term communication. Methods are discussed for achieving long-term communication by using permanent markers and widely disseminated records, with various steps taken to provide multiple levels of protection against loss, destruction, and major language/societal changes. Also developed is the concept of a universal symbol to denote Caution - Biohazardous Waste Buried Here. If used for the thousands of non-radioactive biohazardous waste sites in this country alone, a symbol could transcend generations and language changes, thereby vastly improving the likelihood of successful isolation of all buried biohazardous wastes

Reducing the likelihood of future human activities that could affect geologic high-level waste repositories

Energy Technology Data Exchange (ETDEWEB)

1984-05-01

The disposal of radioactive wastes in deep geologic formations provides a means of isolating the waste from people until the radioactivity has decayed to safe levels. However, isolating people from the wastes is a different problem, since we do not know what the future condition of society will be. The Human Interference Task Force was convened by the US Department of Energy to determine whether reasonable means exist (or could be developed) to reduce the likelihood of future human unintentionally intruding on radioactive waste isolation systems. The task force concluded that significant reductions in the likelihood of human interference could be achieved, for perhaps thousands of years into the future, if appropriate steps are taken to communicate the existence of the repository. Consequently, for two years the task force directed most of its study toward the area of long-term communication. Methods are discussed for achieving long-term communication by using permanent markers and widely disseminated records, with various steps taken to provide multiple levels of protection against loss, destruction, and major language/societal changes. Also developed is the concept of a universal symbol to denote Caution - Biohazardous Waste Buried Here. If used for the thousands of non-radioactive biohazardous waste sites in this country alone, a symbol could transcend generations and language changes, thereby vastly improving the likelihood of successful isolation of all buried biohazardous wastes.

Quality assurance records system for research and development activities in support of geologic repository programs

International Nuclear Information System (INIS)

Smith, J.W.; Ryder, D.E.

1987-01-01

The Pacific Northwest Laboratory (PNL), which is operated by Battelle Memorial Institute for the Department of Energy, is conducting site-specific research for all three candidate sites for the first geologic high-level waste repository, as well as generic research for the second repository. In conjunction with this effort, PNL has developed a quality assurance (QA) program that is applicable to all organizations that are performing research and development (R and D) activities in support of the repository programs. This QA program meets the basic and supplemental requirements of ANSI/ASME NQA-1-1983 and the Nuclear Regulatory Commission (NRC) Review Plan for QA Programs for Site Characterization of High Level Nuclear Waste Repositories. A key part of this program is the handling of QA records that may ultimately support the licensing process for the repository. This paper describes a QA records system that is flexible enough to accommodate several types of research, such as paper studies, test method development, site characterization studies, software development, and hardware design. In addition, the QA records system is acceptable to a variety of sponsors who have licensing concerns. The QA procedures and their relation to the requirements are described. Most important is the discussion on the approaches used to assure that the records are organized such that the user can readily recreate or defend data, conclusions, and recommendations resulting from the research

Sandstone uranium deposits of Meghalaya: natural analogues for radionuclide migration and backfill material in geological repository for high level radioactive waste disposal

International Nuclear Information System (INIS)

Bajpai, R.K.; Narayan, P.K.

2008-01-01

Sandstone uranium deposits serve as potential natural analogue to demonstrate safety offered by geological media against possible release of nuclear waste from their confinement and migration towards biosphere. In this study, available database on geochemical aspects of Domisiat uranium deposit of Meghalaya has been evaluated to highlight the behavior of radionuclides of concern over long term in a geological repository. Constituents like actinides (U and Th), fission products and RE elements are adequately retained in clays and organic matters associated with these sandstone deposits. The study also highlights the possibility of utilization of lean ore discarded during mining and milling as backfill material in far field areas and optimizing near field buffers/backfills in a geological repository located in granitic rocks in depth range of 400-500m. (author)

Radionuclide transport behavior in a generic geological radioactive waste repository.

Science.gov (United States)

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

2015-01-01

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

Design information verification for spent fuel conditioning plants and for geological repositories

International Nuclear Information System (INIS)

Myatt, J.; Ward, M.D.

1995-01-01

The disposal of spent fuel is a major option for the back-end of the nuclear fuel cycle. It will require the construction, operation and eventual closure of conditioning plants and geological repositories. Consequently, a safeguards approach including Design Information Verification (DIV) must be developed for these facilities. DIV Is the examination of a completed facility to verify that it has been built to the design declared by the operator. Although DIV takes place chiefly before a plant begins routine operation, there is a continuing interest in ensuring that the plant remains as declared. That is, that the continuity of knowledge of design information is maintained during the operational phase of the plant and also post closure if necessary. A major problem with DIV of a repository is that there will be continuous structural changes during its operational life requiring advanced or special techniques for reverification. Some of these are briefly reviewed. Furthermore, since a disposal facility is expected to be operational for several decades, new mining technology may also have an impact on the DIV methods employed. Another factor in the safeguards supervision of a repository is that when the fuel has been backfilled and/or scaled in place a reassay will be a very costly exercise. The role of DIV in such novel circumstances must, therefore, be fully considered

Sorption of plutonium and americium on repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura

International Nuclear Information System (INIS)

Baston, G.M.N.; Berry, J.A.; Brownsword, M.; Heath, T.G.; Tweed, C.J.; Williams, S.J.

1995-01-01

An integrated program of batch sorption experiments and mathematical modeling has been carried out to study the sorption of plutonium and americium on a series of repository, backfill and geological materials relevant to the JNFL low-level radioactive waste repository at Rokkasho-Mura. The sorption of plutonium and americium on samples of concrete, mortar, sand/bentonite, tuff, sandstone and cover soil has been investigated. In addition, specimens of bitumen, cation and anion exchange resins, and polyester were chemically degraded. The resulting degradation product solutions, alongside solutions of humic and isosaccharinic acids were used to study the effects on plutonium sorption onto concrete, sand/bentonite and sandstone. The sorption behavior of plutonium and americium has been modeled using the geochemical speciation program HARPHRQ in conjunction with the HATCHES database

Implications of monitored retrievable storage for geologic disposal of spent nuclear fuel and high level radioactive waste

International Nuclear Information System (INIS)

Halstead, R.J.; Kidwell, S.M.; Woodbury, D.

1986-01-01

The integral monitored retrievable storage (I-MRS) proposal has major implications for geologic disposal. This paper reviews the positive and negative implications from the standpoint of a potential repository host state. Recommendations for improving the I-MRS proposal include: eliminate provisions restricting I-MRS backup role; add provisions to prevent I-MRS from becoming a permanent disposal facility; optimize reactor-to-I-MRS transportation system; further shift preclosure operations from repository to I-MRS; defer decision on rod consolidation; repeat the I-MRS site selection process; eliminate any potential linkage between I-MRS and nuclear weapons programs; and incorporate I-MRS in the repository siting program

Risk analysis for repositories in north Switzerland. Extent and probability of geologic processes and events

Energy Technology Data Exchange (ETDEWEB)

Buergisser, H M; Herrnberger, V

1981-07-01

The literature study assesses, in the form of expert analysis, geological processes and events for a 1200 km/sup 2/-area of northern Switzerland, with regard to repositories for medium- and high-active waste (depth 100 to 600 m and 600 to 2500 m, respectively) over the next 10/sup 6/ years. The area, which comprises parts of the Tabular Jura, the folded Jura and the Molasse Basin, the latter two being parts of the Alpine Orogene, has undergone a non-uniform geologic development since the Oligocene. Within the next 10/sup 4/ to 10/sup 5/ years a maximum earthquake intensity of VIII-IX (MSK-scale) has been predicted. After this period, particularly in the southern and eastern parts of the area, glaciations will probably occur, with asociated erosion of possibly 200 to 300 m. Fluvial erosion as a response to an uplift could reach similar values after 10/sup 5/ to 10/sup 6/ years; however, there are no data on the recent relative vertical crustal movements of the area. The risk of a meteorite impact is considered small as compared to that of these factors. Seismic activity and the position and extent of faults are so poorly known within the area that the faulting probability cannot be derived at present. Flooding by the sea, intrusion of magma, diapirism, metamorphism and volcanic eruptions are not considered to be risk factors for final repositories in northern Switzerland. For the shallow-type repositories, the risk of denudation and landslides have to be judged when locality-bound projects have been proposed.

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

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.

Effect of reprocessing and recycling on the geologic repository dose rate : status

International Nuclear Information System (INIS)

Morris, E. E.; Nutt, W. M.; Wigeland, R. A.; Nuclear Engineering Division

2007-01-01

Two simplified repository performance assessment models are used to assess the impact of modeling changes in on conclusions regarding the impact of various reprocessing and recycling strategies. Waste streams from a pressurized water reactor (PWR) and a preliminary design for an advanced burner test reactor (ABTR) are used for this study of the effects on the estimated dose rate resulting from the release of radionuclides from a geologic repository. Calculations for the PWR make use of radionuclide discharge vectors for an assumed burnup of 51 GWd/MTIHM[1]. The repository is assumed to be filled with 70,000 MT of the spent fuel or with a glass waste form containing the radionuclides from 70,000 MT of spent PWR fuel. For the ABTR, the radionuclide inventory discharged at the end of an equilibrium cycle[2] is processed into a glass waste form for repository disposal, assuming actinide recovery efficiencies ranging from 90% to 99.99%. The recovered actinides are returned to the reactor. To compare with the PWR results, the repository is assumed to be filled with ABTR waste from fuel that has generated the same amount of thermal energy as 70,000 MT of the PWR fuel. The two repository performance assessment models, the first a simplified model[3] (SSR) based on the site recommendation model used by the Yucca Mountain Project (YMP)[4], and the second an updated simplified model (US) based on more recent modeling developments by the YMP are implemented in the computer simulation code GoldSim[5]. The updated model is based on a simplified model used to conduct a sensitivity analysis to evaluate factors that potentially influence performance of a repository at Yucca Mountain over the period of peak dose[6]. Factors that have either a minor or no effect on the peak dose either were not included in that simplified model or were included in a bounding representation. In the US model, enhancements were made to include some factors that have an effect on the dose occurring

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

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

Approach to geologic repository post closure system performance assessment

International Nuclear Information System (INIS)

Pahwa, S.B.; Felton, W.; Duguid, J.O.

1992-01-01

An essential part of the license application for a geologic repository will be the demonstration of compliance with the standards set by the Environmental Protection Agency. The performance assessments that produce the demonstration must rely on models of various levels of detail. The most detailed of these models are needed for understanding thoroughly the complex physical and chemical processes affecting the behavior of the system. For studying the behavior of major components of the system, less detailed models are often useful. For predicting the behavior of the total system, models of a third kind may be needed. These models must cover all the important processes that contribute to the behavior of the system, because they must estimate the behavior under all significant conditions for 10,000 years. In addition, however, computer codes that embody these models must calculate very rapidly because of the EPA standard's requirement for probabilistic estimates, which will be produced by sampling thousands of times from probability distributions of parameters. For this reason, the total-system models must be less complex than the detailed-process and subsystem models. The total-system performance is evaluated through modeling of the following components: Radionuclide release from the engineered-barrier system. Fluid flow in the geologic units. Radionuclide transport to the accessible environment. Radionuclide release to the accessible environment and dose to man

New simulation tools for long-term hydraulic design for a geological repository

International Nuclear Information System (INIS)

Richard, S.; Chaudon, L.

1995-01-01

Hydraulic concepts for a geological repository were investigated. Numerical simulations were adapted for this purpose and an experimental rheoelectric method based on an analogy between hydraulic flows and electric currents was developed. The results are discussed in this paper. A simplified representation of the host rock was adopted to account for the geometric details of the concept; this rock was described by a homogeneous porous medium associated with two major discontinuities. Steady-state hydraulic conditions were considered, and heating by the waste packages was assumed to be negligible (these conditions correspond to the long-term repository setting). The hydraulic structures obtained by the two methods are comparable, but significant differences were observed in the drained water distribution in the excavations; these discrepancies highlight the importance of the calculation mesh dimensions. Drainage barriers (drainage drifts and boreholes) surrounding the disposal boreholes may reduce water circulation in the disposal areas to their initial levels by constituting a partial hydraulic Faraday cage. This could be achieved with a reasonable number of boreholes if necessary

Evaluation of radionuclide migration in the homogeneous system of a geological repository

International Nuclear Information System (INIS)

Prvakova, S.; Duran, J.; Necas, V.

2005-01-01

The aim of this paper is to study radionuclide migration and release from a deep underground repository situated in a clay formation. An insight into the processes influencing the radionuclide transport in the near field and far field will be presented. For the calculation, a set of radionuclides has been chosen, considering the half-life, decay chains, capacity of the sorption, solubility limits and diffusion coefficients. The migration of radionuclides is dependent on transport properties of the particular nuclide. Due to the low hydraulic conductivity of the backfill material and clay geological formation, the transport in the repository occurs mainly by diffusion. The migration rate will be influenced by the water chemistry, solubility, retardation and diffusive properties of the nuclides, and the water flow rate in the clay. The release rates of radionuclides from the geosphere to the biosphere will be converted into the indicative dose rates using dose conversion factors for ingestion. The impact of the critical group is considered via consumption of meat, root vegetables and drinking water from wells. (author)

Results From an International Simulation Study on Coupled Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories

International Nuclear Information System (INIS)

J. Rutqvist; D. Barr; J.T. Birkholzer; M. Chijimatsu; O. Kolditz; Q. Liu; Y. Oda; W. Wang; C. Zhang

2006-01-01

As part of the ongoing international DECOVALEX project, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near waste emplacement drifts of geological nuclear waste repositories. The simulations were conducted for two generic repository types, one with open and the other with back-filled repository drifts, under higher and lower postclosure temperatures, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses is currently being resolved. In particular, good agreement in the basic thermal-mechanical responses was achieved for both repository types, even though some teams used relatively simplified thermal-elastic heat-conduction models that neglected complex near-field thermal-hydrological processes. The good agreement between the complex and simplified process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level

The United States Polar Rock Repository: A geological resource for the Earth science community

Science.gov (United States)

Grunow, Annie M.; Elliot, David H.; Codispoti, Julie E.

2007-01-01

The United States Polar Rock Repository (USPRR) is a U. S. national facility designed for the permanent curatorial preservation of rock samples, along with associated materials such as field notes, annotated air photos and maps, raw analytic data, paleomagnetic cores, ground rock and mineral residues, thin sections, and microfossil mounts, microslides and residues from Polar areas. This facility was established by the Office of Polar Programs at the U. S. National Science Foundation (NSF) to minimize redundant sample collecting, and also because the extreme cold and hazardous field conditions make fieldwork costly and difficult. The repository provides, along with an on-line database of sample information, an essential resource for proposal preparation, pilot studies and other sample based research that should make fieldwork more efficient and effective. This latter aspect should reduce the environmental impact of conducting research in sensitive Polar Regions. The USPRR also provides samples for educational outreach. Rock samples may be borrowed for research or educational purposes as well as for museum exhibits.

Staff Technical Position on geological repository operations area underground facility design: Thermal loads

International Nuclear Information System (INIS)

Nataraja, M.S.

1992-12-01

The purpose of this Staff Technical Position (STP) is to provide the US Department of Energy (DOE) with a methodology acceptable to the Nuclear Regulatory Commission staff for demonstrating compliance with 10 CFR 60.133(i). The NRC staff's position is that DOE should develop and use a defensible methodology to demonstrate the acceptability of a geologic repository operations area (GROA) underground facility design. The staff anticipates that this methodology will include evaluation and development of appropriately coupled models, to account for the thermal, mechanical, hydrological, and chemical processes that are induced by repository-generated thermal loads. With respect to 10 CFR 60.133(i), the GROA underground facility design: (1) should satisfy design goals/criteria initially selected, by considering the performance objectives; and (2) must satisfy the performance objectives 10 CFR 60.111, 60.112, and 60.113. The methodology in this STP suggests an iterative approach suitable for the underground facility design

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)

Assessment of effectiveness of geologic isolation systems: the AEGIS geologic simulation model

International Nuclear Information System (INIS)

Foley, M.G.; Petrie, G.M.

1981-02-01

Assessment of the post-closure performance of a nuclear waste repository has two basic components: the identification and analysis of potentially disruptive sequences and the pattern of geologic events and processes causing each sequence, and the identification and analysis of the environmental consequences of radionuclide transport and interactions subsequent to disruption of a repository. The AEGIS Scenario Analysis Task is charged with identifying and analyzing potenially disruptive sequences of geologic events and processes. The Geologic Simulation Model (GSM) was developed to evaluate the geologic/hydrologic system surrounding an underground repository, and describe the phenomena that alone, or in concert, could perturb the system and possibly cause a loss of repository integrity. The AEGIS approach is described in this report. It uses an integrated series of models for repository performance analysis; the GSM for a low-resolution, long-term, comprehensive evaluation of the geologic/hydrologic system, followed by more detailed hydrogeologic, radionuclide transport, and dose models to more accurately assess the consequences of disruptive sequences selected from the GSM analyses. This approach is felt to be more cost-effective than an integrated one because the GSM can be used to estimate the likelihoods of different potentially disruptive future evolutionary developments within the geologic/hydrologic system. The more costly consequence models can then be focused on a few disruptive sequences chosen for their representativeness and effective probabilities

THE DECISION TO RECOMMEND YUCCA MOUNTAIN AND THE NEXT STEPS TOWARD LICENSED REPOSITORY DEVELOPMENT

International Nuclear Information System (INIS)

Barrett, L. H.

2002-01-01

After more than 20 years of carefully planned and reviewed scientific field work by the U.S. Department of Energy, the U.S. Geological Survey, and numerous other organizations, Secretary of Energy Abraham concluded in January that the Yucca Mountain site is suitable, within the meaning of the Nuclear Waste Policy Act, for development as a permanent nuclear waste and spent fuel repository. In February, the Secretary recommended to the President that the site be developed for licensed disposal of these wastes, and the President transmitted this recommendation to Congress. This paper summarizes key technical and national interest considerations that provided the basis for the recommendation. It also discusses the program's near-term plans for repository development if Congress designates the site

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)

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

Selection of nuclide decay chains for use in the assessment of the radiological impact of geological repositories for radioactive waste

International Nuclear Information System (INIS)

Thorne, M.C.

1982-12-01

The criteria for selecting nuclide decay chains for use in the assessment of the radiological impact of geological repositories for radioactive waste are given. The reduced chains recommended for use with SYVAC are described. (author)

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

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

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

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 22. Nuclear considerations for repository design

International Nuclear Information System (INIS)

1978-04-01

This volume, Y/OWI/TM-36/22, ''Nuclear Considerations for Repository Design,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. Included in this volume are baseline design considerations such as characteristics of canisters, drums, casks, overpacks, and shipping containers; maximum allowable and actual decay-heat levels; and canister radiation levels. Other topics include safeguard and protection considerations; occupational radiation exposure including ALARA programs; shielding of canisters, transporters and forklift trucks; monitoring considerations; mine water treatment; canister integrity; and criticality calculations

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

Evaluation of geological documents available for provisional safety analyses of potential sites for nuclear waste repositories - Are additional geological investigations needed?

International Nuclear Information System (INIS)

2010-10-01

The procedure for selecting repository sites for all categories of radioactive waste in Switzerland is defined in the conceptual part of the Sectoral Plan for Deep Geological Repositories, which foresees a selection of sites in three stages. In Stage I, Nagra proposed geological siting regions based on criteria relating to safety and engineering feasibility. The Swiss Government (the Federal Council) is expected to decide on the siting proposals in 2011. The objective of Stage 2 is to prepare proposals for the location of the surface facilities within the planning perimeters defined by the Federal Council in its decision on Stage 1 and to identify potential sites. Nagra also has to carry out a provisional safety analysis for each site and a safety-based comparison of the sites. Based on this, and taking into account the results of the socio-economic-ecological impact studies, Nagra then has to propose at least two sites for each repository type to be carried through to Stage 3. The proposed sites will then be investigated in more detail in Stage 3 to ensure that the selection of the sites for the General Licence Applications is well founded. In order to realise the objectives of the upcoming Stage 2, the state of knowledge of the geological conditions at the sites has to be sufficient to perform the provisional safety analyses. Therefore, in preparation for Stage 2, the conceptual part of the Sectoral Plan requires Nagra to clarify the need for additional investigations aimed at providing input for the provisional safety analyses. The purpose of the present report is to document Nagra's technical-scientific assessment of this need. The focus is on evaluating the geological information based on processes and parameters that are relevant for safety and engineering feasibility. In evaluating the state of knowledge the key question is whether additional information could lead to a different decision regarding the selection of the sites to be carried through to Stage 3

AEGIS technology demonstration for a nuclear waste repository in basalt. Assessment of effectiveness of geologic isolation systems

International Nuclear Information System (INIS)

Dove, F.H.; Cole, C.R.; Foley, M.G.

1982-09-01

A technology demonstration of current performance assessment techniques as applied to a nuclear waste repository in the Columbia Plateau Basalts was conducted. Hypothetical repository coordinates were selected for an actual geographical setting on the Hanford Reservation in the state of Washington. Published hydrologic and geologic data used in the analyses were gathered in 1979 or earlier. The following report documents the technology demonstration in basalt. Available information has been used to establish the data base and initial hydrologic and geologic interpretations for this site-specific application. A simplified diagram of the AEGIS analyses is shown. Because an understanding of the dynamics of ground-water flow is essential to the development of release scenarios and consequence analyses, a key step in the demonstration is the systems characterization contained in the conceptual model. Regional and local ground-water movement patterns have been defined with the aid of hydrologic computer models. Hypothetical release scenarios have been developed and evaluated by a process involving expert opinion and a Geologic Simulation Model for basalt. (The Geologic Simulation Model can also be used to forecast future boundary conditions for the hydrologic simulation.) Chemical reactivity of the basalt with ground water will influence the leaching and transport of radionuclides; solubility equilibria based on available data are estimated with geochemical models. After the radionuclide concentrations are mathematically introduced into the ground-water movement patterns, waste movement patterns are outlined over elapsed time. Contaminant transport results are summarized for significant radionuclides that are hypothetically released to the accessible environment and to the biosphere

AEGIS technology demonstration for a nuclear waste repository in basalt. Assessment of effectiveness of geologic isolation systems

Energy Technology Data Exchange (ETDEWEB)

Dove, F.H.; Cole, C.R.; Foley, M.G.

1982-09-01

A technology demonstration of current performance assessment techniques as applied to a nuclear waste repository in the Columbia Plateau Basalts was conducted. Hypothetical repository coordinates were selected for an actual geographical setting on the Hanford Reservation in the state of Washington. Published hydrologic and geologic data used in the analyses were gathered in 1979 or earlier. The following report documents the technology demonstration in basalt. Available information has been used to establish the data base and initial hydrologic and geologic interpretations for this site-specific application. A simplified diagram of the AEGIS analyses is shown. Because an understanding of the dynamics of ground-water flow is essential to the development of release scenarios and consequence analyses, a key step in the demonstration is the systems characterization contained in the conceptual model. Regional and local ground-water movement patterns have been defined with the aid of hydrologic computer models. Hypothetical release scenarios have been developed and evaluated by a process involving expert opinion and a Geologic Simulation Model for basalt. (The Geologic Simulation Model can also be used to forecast future boundary conditions for the hydrologic simulation.) Chemical reactivity of the basalt with ground water will influence the leaching and transport of radionuclides; solubility equilibria based on available data are estimated with geochemical models. After the radionuclide concentrations are mathematically introduced into the ground-water movement patterns, waste movement patterns are outlined over elapsed time. Contaminant transport results are summarized for significant radionuclides that are hypothetically released to the accessible environment and to the biosphere.

Status of technology for isolating high-level radioactive wastes in geologic repositories

International Nuclear Information System (INIS)

Klingsberg, C.; Duguid, J.

1980-10-01

This report attempts to summarize the status of scientific and technological knowledge relevant to long-term isolation of high-level and transuranic wastes in a mined geologic repository. It also identifies and evaluates needed information and identifies topics in which work is under way or needed to reduce uncertainties. The major findings and conclusions on the following topics are presented: importance of the systems approach; prospects for successful isolation of wastes; need for site-specific investigations; human activities in the future; importance of modelling; disposal of transuranic wastes; status of technology of isolation barriers, performance assessment, site selection and characterization, and potential host rocks

Researching radioactive waste disposal. [Underground repository

Energy Technology Data Exchange (ETDEWEB)

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

1976-02-16

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

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

On risk analysis for repositories in northern Switzerland: extent and probability of geological processes and events

International Nuclear Information System (INIS)

Buergisser, H.M.; Herrnberger, V.

1981-01-01

The literature study assesses, in the form of expert analysis, geological processes and events for a 1200 km 2 -area of northern Switzerland, with regard to repositories for medium- and high-active waste (depth 100 to 600 m and 600 to 2500 m, respectively) over the next 10 6 years. The area, which comprises parts of the Tabular Jura, the folded Jura and the Molasse Basin, the latter two being parts of the Alpine Orogene, has undergone a non-uniform geologic development since the Oligocene. Within the next 10 4 to 10 5 years a maximum earthquake intensity of VIII-IX (MSK-scale) has been predicted. After this period, particularly in the southern and eastern parts of the area, glaciations will probably occur, with associated erosion of possibly 200 to 300 m. Fluvial erosion as a reponse to an uplift could reach similar values after 10 5 to 10 6 years; however, there are no data on the recent relative vertical crustal movements of the area. The risk of a meteorite impact is considered small as compared to that of these factors. Seismic activity and the position and extent of faults are so poorly known within the area that the faulting probability cannot be derived at present. Flooding by the sea, intrusion of magma, diapirism, metamorphism and volcanic eruptions are not considered to be risk factors for final repositories in northern Switzerland. For the shallow-type repositories, the risk of denudation and landslides have to be judged when locality-bound projects have been proposed. (Auth.)

Cost Comparison for the Transfer of Select Calcined Waste Canisters to the Monitored Geologic Repository at Yucca Mountain, NV

International Nuclear Information System (INIS)

Michael B. Heiser; Clark B. Millet

2005-01-01

This report performs a life-cycle cost comparison of three proposed canister designs for the shipment and disposition of Idaho National Laboratory high-level calcined waste currently in storage at the Idaho Nuclear Technology and Engineering Center to the proposed national monitored geologic repository at Yucca Mountain, Nevada. Concept A (2 x 10-ft) and Concept B (2 x 15-ft) canisters are comparable in design, but they differ in size and waste loading options and vary proportionally in weight. The Concept C (5.5 x 17.5-ft) canister (also called the ''super canister''), while similar in design to the other canisters, is considerably larger and heavier than Concept A and B canisters and has a greater wall thickness. This report includes estimating the unique life-cycle costs for the three canister designs. Unique life-cycle costs include elements such as canister purchase and filling at the Idaho Nuclear Technology and Engineering Center, cask preparation and roundtrip consignment costs, final disposition in the monitored geologic repository (including canister off-loading and placement in the final waste disposal package for disposition), and cask purchase. Packaging of the calcine ''as-is'' would save $2.9 to $3.9 billion over direct vitrification disposal in the proposed national monitored geologic repository at Yucca Mountain, Nevada. Using the larger Concept C canisters would use 0.75 mi less of tunnel space, cost $1.3 billion less than 10-ft canisters of Concept A, and would be complete in 6.2 years

Continuing Science and Technology at the Proposed Yucca Mountain Repository

International Nuclear Information System (INIS)

Finch, R.J.

2005-01-01

Yucca Mountain, Nevada, was designated in 2002 to be the site for the nation's first permanent geological repository for spent nuclear fuel and high-level radioactive waste. The process of selecting a site for the repository began nearly 25 years ago with passage of the Nuclear Waste Policy Act in 1982. The Department of Energy (DOE) is responsible for submitting a license application to the Nuclear Regulatory Commission for constructing and operating the repository, and DOE's Office of Civilian Radioactive Waste Management (OCRWM) is charged with carrying out this action. The use of multiple natural and engineered barriers in the current repository design are considered by OCRWM to be sufficiently robust to warrant license approval; however, potential design enhancements and increased understanding of both natural and engineered barriers, especially over the long time frames during which the waste is to remain isolated from human contact continue to be examined. The Office of Science and Technology and International (OST andI) was created within OCRWM to help explore novel technologies that might lower overall costs and to develop a greater understanding of processes relevant to the long-term performance of the repository. A brief overview of Yucca Mountain, and the role that OST andI has in identifying technological or scientific advances that could make repository operations more efficient or performance more robust, will be presented. It is important to note, however, that adopting any of OST andI's technological or scientific developments will be at the discretion of OCRWM's Office of Repository Development (ORD)

Geotechnical support and topical studies for nuclear waste geologic repositories

International Nuclear Information System (INIS)

1989-01-01

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

Experiments on thermal conductivity in buffer materials for geologic repository

International Nuclear Information System (INIS)

Kanno, T.; Yano, T.; Wakamatsu, H.; Matsushima, E.

1989-01-01

Engineered barriers for geologic disposal for HLW are planned to consist of canister, overpack and buffer elements. One of important physical characteristics of buffer materials is determining temperature profiles within the near field in a repository. Buffer materials require high thermal conductivity to disperse radiogenic heat away to the host rock. As the buffer materials, compacted blocks of the mixture of sodium bentonite and sand have been the most promising candidate in some countries, e.g. Sweden, Switzerland and Japan. The authors have been carrying out a series of thermal dispersion experiments to evaluate thermal conductivity of bentonite/quartz sand blocks. In this study, the following two factors considered to affect thermal properties of the near field were examined: effective thermal conductivities of buffer materials, and heat transfer characteristics of the gap between overpack and buffer materials

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

Reference repository design concept for bedded salt

Energy Technology Data Exchange (ETDEWEB)

Carpenter, D.W.; Martin, R.W.

1980-10-08

A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood.

Reference repository design concept for bedded salt

International Nuclear Information System (INIS)

Carpenter, D.W.; Martin, R.W.

1980-01-01

A reference design concept is presented for the subsurface portions of a nuclear waste repository in bedded salt. General geologic, geotechnical, hydrologic and geochemical data as well as descriptions of the physical systems are provided for use on generic analyses of the pre- and post-sealing performance of repositories in this geologic medium. The geology of bedded salt deposits and the regional and repository horizon stratigraphy are discussed. Structural features of salt beds including discontinuities and dissolution features are presented and their effect on repository performance is discussed. Seismic hazards and the potential effects of earthquakes on underground repositories are presented. The effect on structural stability and worker safety during construction from hydrocarbon and inorganic gases is described. Geohydrologic considerations including regional hydrology, repository scale hydrology and several hydrological failure modes are presented in detail as well as the hydrological considerations that effect repository design. Operational phase performance is discussed with respect to operations, ventilation system, shaft conveyances, waste handling and retrieval systems and receival rates of nuclear waste. Performance analysis of the post sealing period of a nuclear repository is discussed, and parameters to be used in such an analysis are presented along with regulatory constraints. Some judgements are made regarding hydrologic failure scenarios. Finally, the design and licensing process, consistent with the current licensing procedure is described in a format that can be easily understood

Geological repository layout for radioactive high level long lived waste in argillite

International Nuclear Information System (INIS)

Gaussen, JL

2006-01-01

In the framework of the 1991 French radioactive waste act, ANDRA has studied the feasibility of a geological repository in the argillite layer of the Bure site for high level long lived waste. This presentation is focussed on the underground facilities which constitute the specific component of this project. The preliminary underground layout which has been elaborated is based on four categories of data: - the waste characteristics and inventory; - the geological properties of the host argillite; - the long term performance objectives of the repository; - the specifications in terms of operation and reversibility. The underground facilities consist of two types of works: the access works (shafts and drifts) and the disposal cells. The function of the access works is to permit the implementation of two concurrent activities: the nuclear operations (transfer and emplacement of the disposal packages into the disposal cells) and the construction of the next disposal cells. The design of the drifts network which matches up to this function is also influenced by two other specifications: the minimization of the drift dimensions in order to limit their influence on the integrity of the geological formation and the necessity of a safe ventilation in case of fire. The resulting layout is a network of 4 parallel drifts (2 of them being dedicated to the operation, the other two being dedicated to the construction activities). The average diameter of these access drifts is 7 meters. The link between the surface and the underground is ensured by 4 shafts. The most important function of the disposal cells is to contribute to the long term performance of the repository. In this regard, the thermal and geotechnical considerations play an important role. The B wastes (intermediate level wastes) are not (or not very) exothermic. Consequently, the design of their disposal cells result mainly from geotechnical considerations. The disposal packages (made of concrete) are piled up in

Geology and hydrogeology of the proposed nuclear waste repository at Yucca Mountain, Nevada and the surrounding area

International Nuclear Information System (INIS)

Mattson, S.R.; Broxton, D.E.; Buono, A.; Crowe, B.M.; Orkild, P.P.

1989-01-01

In late 1987 Congress issued an amendment to the Nuclear Waste Policy Act of 1982 which directed the characterization of Yucca Mountain, Nevada as the only remaining potential site for the Nation's first underground high-level radioactive waste repository. The evaluation of a potential underground repository is guided and regulated by policy established by the Department of Energy (DOE), Nuclear Regulatory Commission (NRC), Environmental Protection Agency (EPA), Department of Transportation (DOT), and the US Congress. The Yucca Mountain Project is the responsibility of the DOE. The purpose of this field trip is to introduce the present state of geologic and hydrologic knowledge concerning this site. This report describes the field trip. 108 refs., 6 figs., 1 tab

Draft Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

1999-01-01

The Proposed Action addressed in this EIS is to construct, operate and monitor, and eventually close a geologic repository at Yucca Mountain in southern Nevada for the disposal of spent nuclear fuel and high-level radioactive waste currently in storage at 72 commercial and 5 DOE sites across the United States. The EIS evaluates (1) projected impacts on the Yucca Mountain environment of the construction, operation and monitoring, and eventual closure of the geologic repository; (2) the potential long-term impacts of repository disposal of spent nuclear fuel and high-level radioactive waste; (3) the potential impacts of transporting these materials nationally and in the State of Nevada; and (4) the potential impacts of not proceeding with the Proposed Action

Reference Design Description for a Geologic Repository, Rev. 03, ICN 02

International Nuclear Information System (INIS)

Gerald Shideler

2001-01-01

One of the current major national environmental problems is the safe disposal of large quantities of spent nuclear fuel and high-level radioactive waste materials, which are rapidly accumulating throughout the country. These radioactive byproducts are generated as the result of national defense activities and from the generation of electricity by commercial nuclear power plants. At present, spent nuclear fuel is accumulating at over 70 power plant sites distributed throughout 33 states. The safe disposal of these high-level radioactive materials at a central disposal facility is a high national priority. This Reference Design Description explains the current design for a potential geologic repository that may be located at Yucca Mountain in Nevada for the disposal of spent nuclear fuel and high-level radioactive waste materials. This document describes a possible design for the three fundamental parts of a repository: a surface facility, subsurface repository, and waste packaging. It also presents the current conceptual design of the key engineering systems for the final four phases of repository processes: operations, monitoring, closure, and postclosure. In accordance with current law, this design does not include an interim storage option. In addition, this Reference Design Description reviews the expected long-term performance of the potential repository. It describes the natural barrier system which, together with the engineered systems, achieves the repository objectives. This design will protect the public and the environment by allowing the safe disposal of radioactive waste received from government-owned custodial spent fuel sites, high-level radioactive waste sites, and commercial power reactor sites. All design elements meet or exceed applicable regulations governing the disposal of high-level radioactive waste. The design will provide safe disposal of waste materials for at least a 10,000 year period. During this time interval, natural radioactive decay

Sequential evaluation of the potential geologic repository site at Yucca Mountain, Nevada, USA

International Nuclear Information System (INIS)

Bjerstedt, T.W.

1996-01-01

This paper discusses the changes that are planned for the characterization program at Yucca Mountain due to budget changes. Yucca Mountain is the only site being studied in the US for a geologic repository. Funding for the site characterization program at Yucca Mountain program was cut by roughly one half from the 1994 projected budget to complete three major milestones. These project milestones included: (1) a time-phased determination of site suitability, and if a positive finding, (2) completion of an Environmental Impact Statement, and (3) preparation of a License Application to the US NRC to authorize repository construction. In reaction, Yucca Mountain Site Characterization Project has shifted from parallel development of these milestones to a sequenced approach with the site suitability evaluation being replaced with a management assessment. Changes to the regulatory structure for the disposal program are under consideration by DOE and the NRC. The possibility for NRC and Doe to develop a site-specific regulatory structure follows from the National Energy Policy Act of 1992 that authorized the US EPA to develop a site specific environmental standard for Yucca Mountain

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)

Modeling of irradiated graphite {sup 14}C transfer through engineered barriers of a generic geological repository in crystalline rocks

Energy Technology Data Exchange (ETDEWEB)

Poskas, Povilas; Grigaliuniene, Dalia, E-mail: Dalia.Grigaliuniene@lei.lt; Narkuniene, Asta; Kilda, Raimondas; Justinavicius, Darius

2016-11-01

There are two RBMK-1500 type graphite moderated reactors at the Ignalina nuclear power plant in Lithuania, and they are under decommissioning now. The graphite cannot be disposed of in a near surface repository, because of large amounts of {sup 14}C. Therefore, disposal of the graphite in a geological repository is a reasonable solution. This study presents evaluation of the {sup 14}C transfer by the groundwater pathway into the geosphere from the irradiated graphite in a generic geological repository in crystalline rocks and demonstration of the role of the different components of the engineered barrier system by performing local sensitivity analysis. The speciation of the released {sup 14}C into organic and inorganic compounds as well as the most recent information on {sup 14}C source term was taken into account. Two alternatives were considered in the analysis: disposal of graphite in containers with encapsulant and without it. It was evaluated that the maximal fractional flux of inorganic {sup 14}C into the geosphere can vary from 10{sup −} {sup 11} y{sup −} {sup 1} (for non-encapsulated graphite) to 10{sup −} {sup 12} y{sup −} {sup 1} (for encapsulated graphite) while of organic {sup 14}C it was about 10{sup −} {sup 3} y{sup −} {sup 1} of its inventory. Such difference demonstrates that investigations on the {sup 14}C inventory and chemical form in which it is released are especially important. The parameter with the highest influence on the maximal flux into the geosphere for inorganic {sup 14}C transfer was the sorption coefficient in the backfill and for organic {sup 14}C transfer – the backfill hydraulic conductivity. - Highlights: • Graphite moderated nuclear reactors are being decommissioned. • We studied interaction of disposed material with surrounding environment. • Specifically {sup 14}C transfer through engineered barriers of a geological repository. • Organic {sup 14}C flux to geosphere is considerably higher than inorganic

Cesium and strontium fractionation from HLW for thermal-stress reduction in a geologic repository

International Nuclear Information System (INIS)

McKee, R.W.

1983-02-01

Results are described for a study to assess the benefits and costs of fractionating the cesium and strontium components in commercial high-level waste (HLW) to a separate waste stream for the purpose of reducing geologic repository thermal stresses. System costs are developed for a broad range of conditions comparing the Cs/Sr fractionation concept with disposal of 10-year old vitrified HLW and vitrified HLW aged to achieve (through decay) the same heat output as the fractionated high-level waste (FHLW). All comparisons are based on a 50,000 metric ton equivalent (MTE) system. The FHLW and the Cs/Sr waste are both disposed of a vitrified waste but emplaced in separate areas of a basalt repository. The FHLW is emplaced in high-integrity packages at relatively high waste loading but low heat loading, while the Cs/Sr waste is emplaced in minimum integrity packages at relatively high heat loading. System cost comparisons are based on minimum cost combinations of canister diameter, waste concentration, and canister spacing in a basalt repository for each waste type. The effects on both long- and near-term safety considerations are also addressed. The major conclusion is that the Cs/Sr fractionation concept offers, potentially, a substantial total system cost advantage for HLW disposal if reduced HLW package temperatures in a basalt repository are desired. However, there is no cost advantage if currently designated maximum design temperatures are acceptable. Aging the HLW for 50 to 100 years can accomplish similar results at equivalent or loser costs

Interim performance specifications for conceptual waste-package designs for geologic isolation in salt repositories

International Nuclear Information System (INIS)

1983-06-01

The interim performance specifications and data requirements presented apply to conceptual waste package designs for all waste forms which will be isolated in salt geologic repositories. The waste package performance specifications and data requirements respond to the waste package performance criteria. Subject areas treated include: containment and controlled release, operational period safety, criticality control, identification, and waste package performance testing requirements. This document was generated for use in the development of conceptual waste package designs in salt. It will be revised as additional data, analyses, and regulatory requirements become available

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)

Assessment of Effectiveness of Geologic Isolation Systems: REFERENCE SITE INITIAL ASSESSMENT FOR A SALT DOME REPOSITORY

Energy Technology Data Exchange (ETDEWEB)

Harwell, M. A.; Brandstetter, A.; Benson, G. L.; Raymond, J. R.; Brandley, D. J.; Serne, R. J.; Soldat, J. K.; Cole, C. R.; Deutsch, W. J.; Gupta, S. K.; Harwell, C. C.; Napier, B. A.; Reisenauer, A. E.; Prater, L. S.; Simmons, C. S.; Strenge, D. L.; Washburn, J. F.; Zellmer, J. T.

1982-06-01

As a methodology demonstration for the Office of Nuclear Waste Isolation (ONWI), the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Program conducted an initial reference site analysis of the long-term effectiveness of a salt dome repository. The Hainesville Salt Dome in Texas was chosen to be representative of the Gulf Coast interior salt domes; however, the Hainesville Site has been eliminated as a possible nuclear waste repository site. The data used for this exercise are not adequate for an actual assessment, nor have all the parametric analyses been made that would adequately characterize the response of the geosystem surrounding the repository. Additionally, because this was the first exercise of the complete AEGIS and WASTE Rock Interaction Technology (WRIT) methodology, this report provides the initial opportunity for the methodology, specifically applied to a site, to be reviewed by the community outside the AEGIS. The scenario evaluation, as a part of the methodology demonstration, involved consideration of a large variety of potentially disruptive phenomena, which alone or in concert could lead to a breach in a salt dome repository and to a subsequent transport of the radionuclides to the environment. Without waste- and repository-induced effects, no plausible natural geologic events or processes which would compromise the repository integrity could be envisioned over the one-million-year time frame after closure. Near-field (waste- and repository-induced) effects were excluded from consideration in this analysis, but they can be added in future analyses when that methodology development is more complete. The potential for consequential human intrusion into salt domes within a million-year time frame led to the consideration of a solution mining intrusion scenario. The AEGIS staff developed a specific human intrusion scenario at 100 years and 1000 years post-closure, which is one of a whole suite of possible scenarios. This scenario

Design information verification (DIV) of closed geological repositories (SAGOR activity 3c)

International Nuclear Information System (INIS)

Myatt, J.

1998-02-01

Following IAEA Advisory and Consultants Group meetings in September 1988 and in May 1991 respectively an IAEA multi-national Support Programme Task was initiated to consider the 'Development of Safeguards for Final Disposal of Spent Fuel in Geological Repositories' (SAGOR). A 'Technical Coordination Committee' (TCC) was set up with invited representatives from those Member State Support Programmes wishing to be involved. The joint programme, through the TCC, was given the task of studying the safeguards requirements in: conditioning plant (where the spent fuel is prepared for transfer to the repository); operating repositories (i.e. those in which the fuel is being emplaced); closed repositories. At the first meeting of the TCC in Washington in July 1994 the UK undertook to provide a study of the Design Information Verification (DIV) required in all three areas. For this activity the requirements, techniques and procedures for the Design Information Verification (DIV) of closed repositories have been considered. In completing the study the findings reported for activities 1b/c and 2c (descriptions of a Model Repository and Potential Diversion Paths, respectively) have been used in formulating any conclusions reached. It is also debatable as to whether this activity is strictly speaking DIV or is one of surveillance. As undeclared access can only be made to the emplacement areas of the repository by altering the physical makeup of the surrounding area; i.e. physically changing the 'design' of the surrounding area, however, this is deemed to be DIV. Although the techniques used appear to be those of surveillance they are being applied in this case as the tools of DIV. As with any facility there are a number of stages in its lifetime. For the purposes of this report the operating life of a repository is defined as being the time from inception to when it is finally decommissioned and sealed with the ground surface returned to being a green field. The repository is

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)

Preparing for Construction and Operation of Geological Repositories - Challenges to the Regulator and the Implementer. Proceedings of the Joint RF/IGSC Workshop, Issy-les-Moulineaux, France, 25-27 January 2012

International Nuclear Information System (INIS)

2014-01-01

More radioactive waste management programmes are advancing to a new repository development phase and are preparing for the application of their construction license of a deep geological disposal facility. Such developmental progress brought along significant changes to repository development affecting both the waste management programme implementers and the regulators. New issues impacting both the regulatory authorities and the future facility operators include operational safety and reliability, increased demands on human resources, activities to ensure quality assurance, the additional requirements on information management system and management plans for construction work. To respond to new arising issues, the Radioactive Waste Management Committee (RWMC) of the OECD Nuclear Energy Agency (NEA) has agreed, as stated in the 2011-2016 Strategic Plan, that the Committee will focus on constituencies for the preparation of the construction and operation license of future deep geological repositories. In addition, the Committee will consider operational aspects of repository implementation, both connected to the operational safety and the impact on the post-closure long-term safety. In particular, the RWMC has approved the RWMC Regulator's Forum (RWMC-RF) and the Integration Group for the Safety Case (IGSC) to hold a joint workshop to explore challenging issues and practices in preparing for the application of the construction license of a geological repository. The joint workshop titled 'Preparing for Construction and Operation of Geological Repositories - Challenges to the Regulator and the Implementer' was held on January 25-27, 2012 at the NEA premises in Issy-les-Moulineaux, France. The key objective of the workshop was to identify, and exchange experience on, the current and future challenges faced by the implementers and the regulators when preparing for their application of a construction license of a geological repository. The workshop gave a

Geological mappability of bored versus drill and blast excavations for radioactive waste repositories

International Nuclear Information System (INIS)

Nilsen, B.; Ozdemir, L.

1992-01-01

The issue of accurate geological mappability has been subject of intense debate in the selection of bored versus drill and blast excavation for radioactive waste repositories. This paper is intended to provide an assessment of the problems usually encountered in mappability on the basis of field experience from a large number of completed tunnels, mainly as part of the Norwegian hydropower projects. The main conclusion is that mapping in a mechanically excavated underground opening, with very few exceptions, reflects the in-situ conditions more accurately than mapping in a drill and blast tunnel. This is due to the overbreak effects of drill and blast excavation, primarily

Results from an International Simulation Study on Couples Thermal, Hydrological, and Mechanical (THM) Processes Near Geological Nuclear Waste Repositories

International Nuclear Information System (INIS)

J. Rutqvist; J.T. Birkholzer; M. Chijimatsu; O. Kolditz; Q.S. Liu; Y. Oda; W. Wang; C.Y. Zhang

2006-01-01

As part of the ongoing international code comparison project DECOVALEX, four research teams used five different models to simulate coupled thermal, hydrological, and mechanical (THM) processes near underground waste emplacement drifts. The simulations were conducted for two generic repository types with open or back-filled repository drifts under higher and lower post-closure temperature, respectively. In the completed first model inception phase of the project, a good agreement was achieved between the research teams in calculating THM responses for both repository types, although some disagreement in hydrological responses are currently being resolved. Good agreement in the basic thermal-mechanical responses was achieved for both repository types, even with some teams using relatively simplified thermal-elastic heat-conduction models that neglect complex near-field thermal-hydrological processes. The good agreement between the complex and simplified (and well-known) process models indicates that the basic thermal-mechanical responses can be predicted with a relatively high confidence level. The research teams have now moved on to the second phase of the project, the analysis of THM-induced permanent (irreversible) changes and the impact of those changes on the fluid flow field near an emplacement drift

Annotated outline for the SCP conceptual design report: Office of Geologic Repositories

International Nuclear Information System (INIS)

1987-06-01

The Nuclear Waste Policy Act of 1982 (NWPA) requires that site characterization plans (SCPs) be submitted to the Nuclear Regulatory Commission (NRC), affected States and Indian tribes, and the general public for review and comment prior to the sinking of shafts at a candidate repository site. The SCP is also required by the NRC licensing procedures for the disposal of high-level waste. An Annotated Outline (AO) for Site Characterization Plans (OGR/B-5) has been prepared to provide DOE's standard format and guidance for preparation of SCPs. Consistent with the AO for SCPs. Chapter 6 of the SCP is to provide the requirements and references the media-specific design data base, describe the current design concepts, and discuss design information needs. In order to develop this design information, the Office of Geologic Repositories program is planning a SCP conceptual design phase as part of the overall repository design process. This phase is the first step in the design process, and the result and design can be expected to change as the program moves through the site characterization phase. The Annotated Outline which follows provides the standard format and guidance for the preparation of the SCP Conceptual Design Reports. It is considered to meet the intent of NRC's proposed Generic Technical Position philosophy contained therein. The SCP Conceptual Design Report will be the primary basis for preparation of Chapter 6 of the SCP and will be stand-alone reference document for the SCP. Appendix 1 to this Annotated Outline provides a correlation between Chapter 6 of the SCP and SCP Conceptual Design Report for the information purposes

The technical and economical optimization of the French geological repository project - 59275

International Nuclear Information System (INIS)

Raffard, Rodolphe; Labalette, Thibaud

2012-01-01

Document available in abstract form only. Full text of publication follows: The French Act of 28 June 2006 made the choice of reversible geological repository for long term management of high level and long-lived intermediate level waste. Andra is in charge of designing, building and operating the future industrial repository Cigeo. Current major issues consist in preparing the application to be examined in 2015, planning the construction so that operation would start in 2025 and optimizing the design on both technical and economical points of view. The Dossier 2005 -provided by Andra prior to the 2006 Act- established the feasibility of the project, especially towards compliance with safety and reversibility. Design options were presented at that time with the objective of demonstrating feasibility without ruling out possibilities of further optimization. Along with the scientific and technical review of Dossier 2005, a number of design optimization topics were identified in 2006. Working groups involved Andra's specialists as well as external experts. A particular attention was given to (i) the industrial experience of waste producers and (ii) the characteristics of the clay layer investigated in the Meuse/Haute-Marne Underground Research Laboratory. The 2006 optimization topics were prioritized taking into account their economical impact and the development plan of the project

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

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

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

Repository operational criteria comparative analysis

International Nuclear Information System (INIS)

Hageman, J.P.; Chowdhury, A.H.

1994-06-01

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 among the components of the regulations and impacts of any potential changes to those regulations. The ROC task addresses regulatory criteria and uncertainties related to the preclosure aspects of the geologic repository. Those parts of 10 CFR Part 60 that require routine guidance or minor changes to the rule were addressed in Hageman and Chowdhury, 1992. The ROC task shows a possible need for further regulatory clarity, by major changes to the rule, related to the design bases and siting of a geologic repository operations area and radiological emergency planning in order to assure defense-in-depth. The analyses, presented in this report, resulted in the development and refinement of regulatory concepts and their supporting rationale for recommendations for potential major changes to 10 CFR Pan 0 regulations

Nuclear waste repository in basalt: preconceptual design guidelines

International Nuclear Information System (INIS)

1979-06-01

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

Nuclear waste repository in basalt: preconceptual design guidelines

Energy Technology Data Exchange (ETDEWEB)

1979-06-01

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

Geologic nuclear waste repository site selection studies in the Paradox Basin, Utah

International Nuclear Information System (INIS)

Rogers, T.H.; Conwell, F.R.

1981-01-01

During Phase I regional-level studies, a literature review was conducted to ascertain geologic characteristics pertinent to repository siting factors. On the basis of the regional screening results, four areas in southeastern Utah were selected as being suitable for more detailed study in Phase II: Elk Ridge and Gibson Dome, containing nearly horizontal bedded salt deposits; Salt Valley, containing a diapiric salt anticline; and Lisbon Valley, containing a non-diapiric salt anticline. During current Phase II area studies, the four study areas are being characterized in greater detail than in Phase I. Phase II will culminate in the identification of a potentially suitable location(s), if any, that will be recommended for study in still greater detail in a subsequent phase of work. 5 refs

A literature review of coupled thermal-hydrologic-mechanical-chemical processes pertinent to the proposed high-level nuclear waste repository at Yucca Mountain

International Nuclear Information System (INIS)

Manteufel, R.D.; Ahola, M.P.; Turner, D.R.; Chowdhury, A.H.

1993-07-01

A literature review has been conducted to determine the state of knowledge available in the modeling of coupled thermal (T), hydrologic (H), mechanical (M), and chemical (C) processes relevant to the design and/or performance of the proposed high-level waste (HLW) repository at Yucca Mountain, Nevada. The review focuses on identifying coupling mechanisms between individual processes and assessing their importance (i.e., if the coupling is either important, potentially important, or negligible). The significance of considering THMC-coupled processes lies in whether or not the processes impact the design and/or performance objectives of the repository. A review, such as reported here, is useful in identifying which coupled effects will be important, hence which coupled effects will need to be investigated by the US Nuclear Regulatory Commission in order to assess the assumptions, data, analyses, and conclusions in the design and performance assessment of a geologic reposit''. Although this work stems from regulatory interest in the design of the geologic repository, it should be emphasized that the repository design implicitly considers all of the repository performance objectives, including those associated with the time after permanent closure. The scope of this review is considered beyond previous assessments in that it attempts with the current state-of-knowledge) to determine which couplings are important, and identify which computer codes are currently available to model coupled processes

A literature review of coupled thermal-hydrologic-mechanical-chemical processes pertinent to the proposed high-level nuclear waste repository at Yucca Mountain

Energy Technology Data Exchange (ETDEWEB)

Manteufel, R.D.; Ahola, M.P.; Turner, D.R.; Chowdhury, A.H. [Southwest Research Inst., San Antonio, TX (United States). Center for Nuclear Waste Regulatory Analyses

1993-07-01

A literature review has been conducted to determine the state of knowledge available in the modeling of coupled thermal (T), hydrologic (H), mechanical (M), and chemical (C) processes relevant to the design and/or performance of the proposed high-level waste (HLW) repository at Yucca Mountain, Nevada. The review focuses on identifying coupling mechanisms between individual processes and assessing their importance (i.e., if the coupling is either important, potentially important, or negligible). The significance of considering THMC-coupled processes lies in whether or not the processes impact the design and/or performance objectives of the repository. A review, such as reported here, is useful in identifying which coupled effects will be important, hence which coupled effects will need to be investigated by the US Nuclear Regulatory Commission in order to assess the assumptions, data, analyses, and conclusions in the design and performance assessment of a geologic reposit``. Although this work stems from regulatory interest in the design of the geologic repository, it should be emphasized that the repository design implicitly considers all of the repository performance objectives, including those associated with the time after permanent closure. The scope of this review is considered beyond previous assessments in that it attempts with the current state-of-knowledge) to determine which couplings are important, and identify which computer codes are currently available to model coupled processes.

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)

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.

Technology overview of mined repositories

International Nuclear Information System (INIS)

Gimera, R.; Thirumalai, K.

1982-01-01

Mined repositories present an environmentally viable option for permanent disposal of nuclear waste. This paper reviews the state-of-the-art mining technologies and identifies technological issues and developments necessary to mine a repository in basalt. The thermal loading, isolation, and retrieval requirements of a repository present unique technological challenges unknown to conventional mining practice. The technology issues and developments required in the areas of excavation, roof and ground support, equipment development, instrumentation development, and sealing are presented. Performance assessment methods must be developed to evaluate the adequacies of technologies developed to design, construct, operate, and decommission a repository. A stepwise test-and-development approach is used in the Basalt Waste Isolation Project to develop cost-effective technologies for a repository

GIS for the needs of the Radioactive Waste Repository Authority

Directory of Open Access Journals (Sweden)

Jitka Mikšová

2007-06-01

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

Experimental methodology to study radionuclide sorption and migration in geological formations and engineered barriers of waste repositories

International Nuclear Information System (INIS)

Rojo Sanz, H.

2010-01-01

In Spain, the waste management options include either the possibility of a final storage in a deep geological repository (DGR) or the centralized temporal surface disposal (CTS). DGRs are based in a multi-barrier concept with the geological barrier and including the vitrified waste, the metal containers and engineered barriers such as compacted bentonite and cement-based materials. On the other hand, CTS mainly considers concrete and cement to confine the metal canisters containing the waste. Radionuclide migration will mainly take place by the existence of chemical concentration gradients being thus diffusion the main transport mechanism or by the existence of hydraulic gradients due to the existence of water-conductive fractures. Radionuclide sorption/retention on the materials composing the natural and engineered barriers is the fundamental process controlling contaminant migration. The evaluation of sorption parameters and the understanding of the different mechanisms leading to radionuclide retention are very important issues. The study of diffusion processes is very relevant as well. This paper describes the main experimental methodologies applied to analyse radionuclide transport in the different barriers of radioactive repositories. Particularly we focused on obtaining of retention parameters as distribution coefficients, kd, or retardation factors, Rf, and diffusion coefficients of radionuclides. (Author) 6 refs.

Planning geological underground repositories - Communicating with society

International Nuclear Information System (INIS)

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

2009-06-01

The project 'Planning geological underground repositories: Communicating with society', financed by the Swiss Federal Office for Energy, aimed at identifying basic principles for an appropriate information and communication strategy in the process of finding an underground site to store radioactive wastes. The topic concerns an issue increasingly discussed in modern societies: How to improve the dialogue between science, infrastructure operators, public authorities, groups in civil society and the population to answer complex problems? Against this background, in the project the following questions were taken into account: (i) How can the dialogue between science, politics, economy, and the (non-)organised public be arranged appropriately? Which principles are to be considered in organising this process? How can distrust within the population be reduced and confidence in authorities and scientific expertise be increased? (ii) How can society be integrated in the process of decision-making so that this process is perceived as comprehensible, acceptable and legitimate? To answer these questions, an analysis method based on scientific theory and methodology was developed, which compares national participation and communication processes in finding underground storage sites in selected countries. Case studies have been carried out in Germany, Sweden, Belgium, and Switzerland. By using specific criteria to evaluate communication processes, the strong points as well as the drawbacks of the country-specific concepts of information, communication and participation have been analysed in a comparing dimension. By taking into account the outcomes, prototypical scenarios have been deduced that can serve as a basis for compiling a reference catalogue of measures, which is meant to support the Swiss communication strategy in the finding of an appropriate site for a nuclear waste repository. Following conclusions can be drawn from the international comparison: (i) Open and

Overview of the current CRWMS repository design

International Nuclear Information System (INIS)

Daniel, R.B.; Teraoka, G.M.

1998-01-01

This paper summarizes the current design for a potential geologic repository for spent fuels and high-level wastes at Yucca Mountain, Nevada. The objective of the paper is to present the key design features of the Mined Geologic Disposal System (MGDS) surface facilities and MGDS subsurface facilities. The paper describes the following: surface layout; waste handling operations design; subsurface design; and the underground transport and emplacement design. A more detailed presentation of key features is provided in the ''Reference design description for a geologic repository'' which is located on the YMP Homepage at www.ymp.gov

Evaluation of the heat transfer in a geological repository concept containing PWR, VHTR and hybrid ads-fission spent fuels

Energy Technology Data Exchange (ETDEWEB)

Jonusan, Raoni A.S.; Pereira, Fernando; Velasquez, Carlos E.; Salome, Jean A.D.; Cardoso, Fabiano; Pereira, Claubia; Fortini, Angela, E-mail: claubia@nuclear.ufmg.br [Universidade Federal de Minas Gerais (UFMG), Belo Horizonte, MG (Brazil). Departamento de Engenharia Nuclear

2017-11-01

The investigation of the thermal behavior of spent fuel (SF) materials is essential to determining appropriate potential sites to accommodate geological repositories as well as the design of canisters, considering their potential risk to people health and of environmental contamination. This work presents studies of the temperature in a canister containing spent fuels discharged from Pressurized Water Reactor (PWR), Very High-Temperature Reactor (VHTR) and Accelerator-Driven Subcritical Reactor System (ADS) reactor systems in a geological repository concept. The thermal analyses were performed with the software ANSYS, which is widely used to solve engineering problems through the Finite Element Method. The ANSYS Transient Thermal module was used. The spent nuclear fuels were set as heat sources using data of previous studies derived from decay heat curves. The studies were based on comparison of the mean temperature on a canister surface along the time under geological disposal conditions, for a same amount of each type of spent nuclear fuel evaluated. The results conclude that fuels from VHTR and ADS systems are inappropriate to be disposed in a standardized PWR canister, demanding new studies to determine the optimal amount of spent fuel and new internal canister geometries. It is also possible to conclude that the hypothetical situation of a single type of canister being used to accommodate different types of spent nuclear fuels is not technically feasible. (author)

Sources/treatment of uncertainties in the performance assessment of geologic radioactive waste repositories

International Nuclear Information System (INIS)

Cranwell, R.M.

1987-01-01

Uncertainties in the performance assessment of geologic radioactive waste repositories have several sources. The more important ones include: 1) uncertainty in the conditions of a disposal system over the temporal scales set forth in regulations, 2) uncertainty in the conceptualization of the geohydrologic system, 3) uncertainty in the theoretical description of a given conceptual model of the system, 4) uncertainty in the development of computer codes to implement the solution of a mathematical model, and 5) uncertainty in the parameters and data required in the models and codes used to assess the long-term performance of the disposal system. This paper discusses each of these uncertainties and outlines methods for addressing these uncertainties

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)

Assessing the potentialities of integrated modelling during early phases of siting and design of a geological repository: the REGIME exercise

Energy Technology Data Exchange (ETDEWEB)

Genty, A.; Certes, C.; Serres, C.; Besnus, F. [Institut de Radioprotection et de Surete Nucleaire IRSN, 92 - Fontenay aux Roses (France); Fischer-Appelt, K.; Baltes, B.; Rohlig, J. [Gesellschaft fuer Anlagen- und Reaktorsicherheit mbH (GRS), Koeln (Germany)

2003-01-01

This paper presents the safety assessment exercise 'REGIME' (Repository Evaluation performed by GRS and IRSN through a Modelling Exercise) performed jointly by GRS and IRSN. The main objective of the project is to test the ability of integrated modelling to contribute to site selection and repository conception in the context of high-level radioactive waste disposal. The project is divided in two parts. Phase 1 consisted in studying different flow patterns in a given geological context. The selected hydrogeological contexts and three site locations potentially favourable for hosting a repository are described. Phase 2, under progress, aims at evaluating the rote of limitation of releases played by the different components of the disposal system taking into account possible dysfunctions. The main issues to be addressed in phase 2, the modelling outline and the scenarios to be studied are presented. (authors)

An analysis of repository waste-handling operations

International Nuclear Information System (INIS)

Dennis, A.W.

1990-09-01

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

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)

Technical position on items and activities in the high-level waste geologic repository program subject to quality assurance requirements

International Nuclear Information System (INIS)

Duncan, A.B.; Bilhorn, S.G.; Kennedy, J.E.

1988-04-01

This document provides guidance on how to identify items and activities subject to Quality Assurance in the high-level nuclear waste repository program for pre-closure and post-closure phases of the repository. In the pre-closure phase, structures, systems and components essential to the prevention or mitigation of an accident that could result in an off-site radiation dose of 0.5rem or greater are termed ''important to safety''. In the post-closure phase, the barriers which are relied on to meet the containment and isolation requirements are defined as ''important to waste isolation''. These structures, systems, components, and barriers, and the activities related to their characterization, design, construction, and operation are required to meet quality assurance (QA) criteria to provide confidence in the performance of the geologic repository. The list of structures, systems, and components important to safety and engineered barriers important to waste isolation is referred to as the ''Q-List'' and lies within the scope of the QA program. 10 refs

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)

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

Engineered barrier system and waste package design concepts for a potential geologic repository at Yucca Mountain

International Nuclear Information System (INIS)

Short, D.W.; Ruffner, D.J.; Jardine, L.J.

1991-10-01

We are using an iterative process to develop preliminary concept descriptions for the Engineered Barrier System and waste-package components for the potential geologic repository at Yucca Mountain. The process allows multiple design concepts to be developed subject to major constraints, requirements, and assumptions. Involved in the highly interactive and interdependent steps of the process are technical specialists in engineering, metallic and nonmetallic materials, chemistry, geomechanics, hydrology, and geochemistry. We have developed preliminary design concepts that satisfy both technical and nontechnical (e.g., programmatic or policy) requirements

Nuclear waste repository design and construction

International Nuclear Information System (INIS)

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

1987-01-01

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

Parametric study of geohydrologic performance characteristics for geologic waste repositories

International Nuclear Information System (INIS)

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

1980-11-01

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

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.

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

Modeling of container failure and radionuclide release from a geologic nuclear waste repository

International Nuclear Information System (INIS)

Kim, Chang Lak; Kim, Jhin Wung; Choi, Kwang Sub; Cho, Chan Hee

1989-02-01

Generally, two processes are involved in leaching and dissolution; (1) chemical reactions and (2) mass transfer by diffusion. The chemical reaction controls the dissolution rates only during the early stage of exposure to groundwater. The exterior-field mass transfer may control the long-term dissolution rates from the waste solid in a geologic repository. Masstransfer analyses rely on detailed and careful application of the governing equations that describe the mechanistic processes of transport of material between and within phases. We develop analytical models to predict the radionuclide release rate into the groundwater with five different approaches: a measurement-based model, a diffusion model, a kinetics model, a diffusion-and-kinetics model, and a modified diffusion model. We also collected experimental leaching data for a partial validation of the radionuclide release model based on the mass transfer theory. Among various types of corrosions, pitting is the most significant because of its rapid growth. The failure time of the waste container, which also can be interpreted as the containment time, is a milestone of the performance of a repository. We develop analytical models to predict the pit growth rate on the container surface with three different approaches: an experimental method, a statistical method, and a mathematical method based on the diffusion theory. (Author)

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)

Concepts and examples of safety analyses for radioactive waste repositories in continental geological formations

International Nuclear Information System (INIS)

1983-01-01

This document is addressed to authorities and specialists responsible for or involved in planning, performing and/or reviewing safety assessments of underground radioactive waste repositories. It is a companion to a general introductory document on the subject ''Safety Assessment for the Underground Disposal of Radioactive Wastes'', IAEA Safety Series No. 56, 1981, and reference to this earlier document will facilitate the reader's understanding of the present report. Since examples of safety analyses are summarized here, it is hoped that this document will contribute to providing a basis for a common understanding among authorities and specialists concerned with the numerous studies involving a variety of scientific disciplines. While providing technical information, this document is also intended to stimulate further international discussion. The purposes of this report are: a) to identify the factors to be taken into account in radiological safety analyses of deep geological repositories, indicating as far as possible their relative importance during the various phases of system development; b) to show how these factors have been analysed in various safety assessment studies; and c) to comment on the merits of the selected and alternative approaches

Concepts and examples of safety analyses for radioactive waste repositories in continental geological formations

Energy Technology Data Exchange (ETDEWEB)

1983-01-01

This document is addressed to authorities and specialists responsible for or involved in planning, performing and/or reviewing safety assessments of underground radioactive waste repositories. It is a companion to a general introductory document on the subject ''Safety Assessment for the Underground Disposal of Radioactive Wastes'', IAEA Safety Series No. 56, 1981, and reference to this earlier document will facilitate the reader's understanding of the present report. Since examples of safety analyses are summarized here, it is hoped that this document will contribute to providing a basis for a common understanding among authorities and specialists concerned with the numerous studies involving a variety of scientific disciplines. While providing technical information, this document is also intended to stimulate further international discussion. The purposes of this report are: a) to identify the factors to be taken into account in radiological safety analyses of deep geological repositories, indicating as far as possible their relative importance during the various phases of system development; b) to show how these factors have been analysed in various safety assessment studies; and c) to comment on the merits of the selected and alternative approaches.

A new integrated approach to demonstrate the safe disposal of high-level radioactive waste and spent nuclear fuel in a geological repository

International Nuclear Information System (INIS)

Mueller-Hoeppe, N.; Krone, J.; Niehues, N.; Raitz von Frentz, R.

2000-01-01

Multi-barrier systems are accepted as the basic approach for long term environmental safe isolation of radioactive waste in geological repositories. Assessing the performance of natural and engineered barriers is one of the major difficulties in producing evidence of environmental safety for any radioactive waste disposal facility, due to the enormous complexity of scenarios and uncertainties to be considered. This paper outlines a new methodological approach originally developed basically for a repository in salt, but that can be transferred with minor modifications to any other host rock formation. The approach is based on the integration of following elements: (1) Implementation of a simple method and efficient criteria to assess and prove the tightness of geological and engineered barriers; (2) Using the method of Partial Safety Factors in order to assess barrier performance at certain reasonable level of confidence; (3) Integration of a diverse geochemical barrier in the near field of waste emplacement limiting systematically the radiological consequences from any radionuclide release in safety investigations and (4) Risk based approach for the assessment of radionuclide releases. Indicative calculations performed with extremely conservative assumptions allowed to exclude any radiological health consequences from a HLW repository in salt to a reference person with a safety level of 99,9999% per year. (author)

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

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

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.

Tectonic risk forecasting through expert elicitation for geological repositories: the TOPAZ project

Energy Technology Data Exchange (ETDEWEB)

Goto, Junichi [NUMO, Tokyo (Japan); Kawamura, Hideki [Obayashi Corporation, Tokyo (Japan); Chapman, Neil [MCM Consulting, Baden (Switzerland)

2013-07-01

This paper describes the development of a probabilistic methodology for the evaluation of tectonic hazards to geological repositories in Japan. The approach is a development of NUMO's ITM methodology, which produced probabilistic hazard maps for volcanism and rock deformation for periods up to about 100,000 years in a set of Case Studies that covered a large area of the country. To address potential regulatory requirements, the TOPAZ project has extended the ITM methodology to look into the period between 100,000 and 1 million years, where significant uncertainties begin to emerge about the tectonic framework within which quantitative forecasting can be made. Part of this methodology extension has been to adopt expert elicitation techniques to capture differing expert views as a means of addressing such uncertainties. This paper briefly outlines progress in this development work to date. (authors)

Tectonic risk forecasting through expert elicitation for geological repositories: the TOPAZ project

International Nuclear Information System (INIS)

Goto, Junichi; Kawamura, Hideki; Chapman, Neil

2013-01-01

This paper describes the development of a probabilistic methodology for the evaluation of tectonic hazards to geological repositories in Japan. The approach is a development of NUMO's ITM methodology, which produced probabilistic hazard maps for volcanism and rock deformation for periods up to about 100,000 years in a set of Case Studies that covered a large area of the country. To address potential regulatory requirements, the TOPAZ project has extended the ITM methodology to look into the period between 100,000 and 1 million years, where significant uncertainties begin to emerge about the tectonic framework within which quantitative forecasting can be made. Part of this methodology extension has been to adopt expert elicitation techniques to capture differing expert views as a means of addressing such uncertainties. This paper briefly outlines progress in this development work to date. (authors)

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

Technical issues in the geologic disposal of radioactive wastes

International Nuclear Information System (INIS)

Weart, W.D.

1980-01-01

The status of technical understanding regarding radioactive waste repositories in geologic media is improving at a rapid rate. Within a few years the knowledge regarding non-salt repositories will be on a par with that which now exists for salt. To date there is no technical reason to doubt that geologic repositories in several different geologic media can be safely implemented to provide long-term isolation of radioactive wastes. Indeed, for bedded salt, there is now sufficient knowledge to allow all the identified phenomena to be bounded with satisfactory resultant consequences. It is possible to now proceed with technical confidence in an orderly development of a bedded-salt repository at a satisfactory site. This development would call for in-situ experiments, at the earliest possible stage, to confirm or validate the predictions made for the site. These in-situ experiments will be necessary for each repository in a different rock type. If, for non-technical reasons, repository development is delayed, field test facilities should be located as soon as possible in geologic settings typical of proposed repositories. Extensive testing to resolve generic issues will allow subsequent development of repositories to proceed more rapidly with only minimal in-situ testing required to resolve site-specific concerns

NRC regulations for disposal of high-level radioactive wastes in geologic repositories: technical criteria

International Nuclear Information System (INIS)

Martin, J.B.; Bell, M.J.; Regnier, E.P.

1983-01-01

The Nuclear Regulatory Commission is promulgating regulations specifying the technical criteria fo disposal of high-level radioactive wastes in geologic repositories. The proposed rule was published for public comment in July 1981. Public comments have been received and considered by the Commission staff. The Commission will soon approve and publish a revised final rule. While the final rule being considered by the Commission is fundamentally the same as the proposed rule, provisions have been added to permit flexibility in the application of numerical criteria, some detailed design requirements have been deleted, and other changes have been made in response to comments. The rule is consistent with the recently enacted Nuclear Waste Policy Act of 1982

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.

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.

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

Dissolution kinetics of smectite in geological repository system of TRU waste

International Nuclear Information System (INIS)

Sato, Tsutomu

2005-02-01

Extensive use of cement for encapsulation, mine timbering, and grouting purposes is envisaged in geological repositories of TRU waste. Degradation of cement materials in the repositories can produce a high pH pore fluid initially ranging from pH 13.0 to 13.5. The high pH pore fluids can migrate and react chemically with the host rock and bentonites which were employed to enhance repository's integrity. These chemical reactions can effect the capacity of the rocks and bentonites in retarding the migration of radionuclides. Smectite, main component of bentonite, can lose some of their desirable properties at the early stages of bentonite-cement fluid interaction. This has been a key research issue in performance assessment of TRU waste disposal. In this study, firstly, the factors affected on dissolution rate of smectite and equations describing dissolution rate were reviewed. Secondly, the effect of dissolved silica on the dissolution behavior of Na-montmorillonite was investigated. Bulk sample flow-through dissolution experiments at alkaline condition (pH 13.3) with different dissolved silica concentrations at different temperatures were performed. Titration experiments were also carried out at similar conditions. Atomic Force Microscopy (AFM) ex situ observations (i.e. on samples from flow-through experiments) was also performed to obtain the dissolution rate. Current results from bulk sample surface titration experiments indicate that dissolved silica has no pronounced effect on the surface titration behavior of Na-montmorillonite at any temperature. However, the trends for the surface titration behavior represent the averaged behavior of all particle sizes (i.e. including colloids) such that within an order of magnitude change cannot be quantified appreciably. Bulk flow-through dissolution experiments coupled with ex situ AFM observations indicate that there is also no effect of dissolved silica with comparatively low concentration of the reacting solution on

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)

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

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 12. Repository preconceptual design studies: shale

International Nuclear Information System (INIS)

1978-04-01

This document describes a preconceptual design for a nuclear waste storage facility in shale. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area, and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/13, ''Drawings for Repository Preconceptual Design Studies: Shale.''

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 14. Repository preconceptual design studies: basalt

International Nuclear Information System (INIS)

1978-04-01

This document describes a preconceptual design for a nuclear waste storage facility in basalt. The facility design consists of several chambers excavated deep within a geologic formation together with access shafts and supportive surface structures. The facility design provides for: receiving and unloading waste containers; lowering them down shafts to the mine level; transporting them to the proper storage area and emplacing them in mined storage rooms. Drawings of the facility design are contained in TM-36/15, ''Drawings for Repository Preconceptual Design Studies: Basalt.''

Assessment of Savannah River borosilicate glass in the repository environment

International Nuclear Information System (INIS)

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

1982-04-01

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

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.

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

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

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

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 2. Commercial waste forms, packaging and projections for preconceptual repository design studies

International Nuclear Information System (INIS)

1978-04-01

This volume, Y/OWI/TM-36/2, ''Commercial Waste Forms, Packaging and Projections for Preconceptual Repository Design Studies,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This volume contains the data base for waste forms, packages, and projections from the commercial waste defined by the Office of Waste Isolation in ''Nuclear Waste Projections and Source Term Data for FY 1977,'' Y/OWI/TM-34. Also, as an alternative data base for repository design and analysis, waste forms, packages, and projections for commercial waste defined by Battelle Pacific Northwest Laboratory (BPNL) have been included. This data base consists of a reference case for use in the alternative design study and a definition of combustible wastes for use in mine fire and hydrogen generation analyses

Geologic disposal of radioactive waste, 1983

International Nuclear Information System (INIS)

Pigford, T.H.

1983-10-01

Geologic repositories for radioactive waste are evolving from conceptualization to the development of specific designs. Estimates of long-term hazards must be based upon quantitative predictions of environmental releases over time periods of hundreds of thousands of years and longer. This paper summarizes new techniques for predicting the long-term performance of repositories, it presents estimates of future environmental releases and radiation doses that may result for conceptual repositories in various geologic media, and it compares these predictions with an individual dose criterion of 10 -4 Sv/y. 50 references, 11 figures, 6 tables

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

International Nuclear Information System (INIS)

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

1984-12-01

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

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.

Mined Geologic Disposal System Requirements Document

International Nuclear Information System (INIS)

1994-03-01

This Mined Geologic Disposal System Requirements Document (MGDS-RD) describes the functions to be performed by, and the requirements for, a Mined Geologic Disposal System (MGDS) for the permanent disposal of spent nuclear fuel (SNF) (including SNF loaded in multi-purpose canisters (MPCs)) and commercial and defense high-level radioactive waste (HLW) in support of the Civilian Radioactive Waste Management System (CRWMS). The purpose of the MGDS-RD is to define the program-level requirements for the design of the Repository, the Exploratory Studies Facility (ESF), and Surface Based Testing Facilities (SBTF). These requirements include design, operation, and decommissioning requirements to the extent they impact on the physical development of the MGDS. The document also presents an overall description of the MGDS, its functions (derived using the functional analysis documented by the Physical System Requirements (PSR) documents as a starting point), its segments as described in Section 3.1.3, and the requirements allocated to the segments. In addition, the program-level interfaces of the MGDS are identified. As such, the MGDS-RD provides the technical baseline for the design of the MGDS

The main demands and criteria for building site choice for radioactive waste repositories

International Nuclear Information System (INIS)

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

2002-01-01

There are considered the main demands of building site choice for RAW repositories. At this the accent is placed on geological repositories (underground repositories of geological type) and near surface repositories assigned to disposal of low- and intermediate-level short- and mediate-lived radionuclides. These demands are conditionally separated into two blocks: account of social development of the adjoining territories; account of natural factors characterizing building site. Further there are discussed the questions of anthropogenous influence on a safety functioning of RAW repositories and of urgency of stable development of the adjoining territories. In context of the Ukrainian and other states nuclear laws there is also considered the lawful aspect defining the building site choice for RAW repositories

Geotechnical support and topical studies for nuclear waste geologic repositories: Annual report, fiscal year 1987

International Nuclear Information System (INIS)

1988-01-01

This multidisciplinary project was initiated in fiscal year 1986. It comprises 11 reports in two major interrelated tasks: The technical assistance part of the project includes reviewing the progress of the major projects in the DOE Office of Civilian Radioactive waste Management (OCRWM) Program and advising the Engineering and Geotechnology Division on significant technical issues facing each project; analyzing geotechnical data, reports, tests, surveys and plans for the different projects; reviewing and commenting on major technical reports and other program documents such as Site Characterization Plans (SCP) and Study Plans; and providing scientific and technical input at technical meetings. The topical studies activity comprises studies on scientific and technical ions and issues of significance to in-situ testing, test analysis methods, and site characterization of nuclear waste geologic repositories. The subjects of study were selected based on discussions with DOE staff. One minor topic is a preliminary consideration and planning exercise for postclosure monitoring studies. The major task, with subtasks involving various geoscience disciplines, is a study of the mechanical, hydraulic, geophysical and geochemical properties of fractures in geologic rock masses

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

International Nuclear Information System (INIS)

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

1983-11-01

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

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

International Nuclear Information System (INIS)

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

1993-01-01

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

The Hidden Risk Decisions in Waste Repository Regulation

International Nuclear Information System (INIS)

Frishman, Steve

2001-01-01

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

Approach to resolution of geologic uncertainty in the licensing of a high-level-waste repository in tuff

International Nuclear Information System (INIS)

Neal, J.T.

1983-01-01

Resolution of uncertainty in geological information is an essential element in the licensing process for a geologic repository. Evaluation of these uncertainties within the licensing framework established by the Nuclear Regulatory Commission (NRC) is required. The Nevada Nuclear Waste Storage Investigations (NNWSI), in focusing its site characterization program on unsaturated tuff, has developed a logic hierarchy of technical issues, including key issues, issues, and information needs. Key issues are statements of major requirements whose lack could be disqualifying. An example of a key issue is the demonstration of radionuclide containment and isolation within the required release limits and transport time set by the EPA and NRC. Key issues are broken down into issues, such as the groundwater flow time to the accessible environment. Resolving uncertainty ultimately comes back to satisfying individual information needs that collectively form issues. Hydraulic conductivity is an example of an information need required to determine groundwater flow rate. Sources of uncertainty often arise in either amount, quality, or other limitations in geological data. The hierarchical structuring of geological information needs provides a perspective that allows proportionate attention to be placed on various site characterization activities, and to view them within the whole range of licensing issues that must be satisfied to ensure public health and safety. However, it may not prevent an issue from being contentious, as some geological questions are known to be emotion-laden. The mitigation of uncertainty in geological information ultimately will depend on the validity and credibility of the information presented during the licensing process

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)

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

Establishing MICHCARB, a geological carbon sequestration research and education center for Michigan, implemented through the Michigan Geological Repository for Research and Education, part of the Department of Geosciences at Western Michigan University

Energy Technology Data Exchange (ETDEWEB)

Barnes, David A. [Western Michigan Univ., Kalamazoo MI (United States); Harrison, William B. [Western Michigan Univ., Kalamazoo MI (United States)

2014-01-28

The Michigan Geological Repository for Research and Education (MGRRE), part of the Department of Geosciences at Western Michigan University (WMU) at Kalamazoo, Michigan, established MichCarb—a geological carbon sequestration resource center by: • Archiving and maintaining a current reference collection of carbon sequestration published literature • Developing statewide and site-specific digital research databases for Michigan’s deep geological formations relevant to CO2 storage, containment and potential for enhanced oil recovery • Producing maps and tables of physical properties as components of these databases • Compiling all information into a digital atlas • Conducting geologic and fluid flow modeling to address specific predictive uses of CO2 storage and enhanced oil recovery, including compiling data for geological and fluid flow models, formulating models, integrating data, and running the models; applying models to specific predictive uses of CO2 storage and enhanced oil recovery • Conducting technical research on CO2 sequestration and enhanced oil recovery through basic and applied research of characterizing Michigan oil and gas and saline reservoirs for CO2 storage potential volume, injectivity and containment. Based on our research, we have concluded that the Michigan Basin has excellent saline aquifer (residual entrapment) and CO2/Enhanced oil recovery related (CO2/EOR; buoyant entrapment) geological carbon sequestration potential with substantial, associated incremental oil production potential. These storage reservoirs possess at least satisfactory injectivity and reliable, permanent containment resulting from associated, thick, low permeability confining layers. Saline aquifer storage resource estimates in the two major residual entrapment, reservoir target zones (Lower Paleozoic Sandstone and Middle Paleozoic carbonate and sandstone reservoirs) are in excess of 70-80 Gmt (at an overall 10% storage efficiency factor; an approximately

The velocity dependent dissolution of spent nuclear fuel in a geologic repository

International Nuclear Information System (INIS)

Nutt, W.M.

1990-02-01

A model describing the dissolution of fission products and transuranic isotopes from spent nuclear fuel into flowing ground water has been developed. This model is divided into two parts. The first part of the model calculates the temperature within a consolidated spent fuel waste form at a given time and ground water velocity. This model was used to investigate whether water flowing at rates representative of a geological repository located at Yucca Mountain, Nevada, will cool a wasteform consisting of consolidated spent nuclear fuel pins. Time and velocity dependent temperature profiles were generated. These profiles were input into the second model, which calculates the dissolution rate of waste isotopes from a spent fuel pin. Two dissolution limiting processes were modeled; the processes are dissolution limited by the solubility limit of an isotopes in the ground water, and dissolution limited by the diffusion of waste isotopes from the interior of a spent fuel pin to the surface where dissolution can occur

Geological and geotechnical limitations of radioactive waste retrievability in geologic disposals

Energy Technology Data Exchange (ETDEWEB)

Stahlmann, Joachim; Leon-Vargas, Rocio; Mintzlaff, Volker; Treidler, Ann-Kathrin [TU Braunschweig (Germany). Inst. for Soil Mechanics and Foundation Engineering

2015-07-01

The capability of retrieving radioactive waste emplaced in deep geological formations is nowadays in discussion in many countries. Based on the storage of high-level radioactive waste (HAW) in deep geological repositories there is a number of possible scenarios for their retrieval. Measurements for an improved retrieving capability may impact on the geotechnical and geological barriers, e.g. keeping open the access drifts for a long period of time can result in a bigger evacuation damage zone (EDZ) in the host rock which implies potential flow paths for ground water. Nevertheless, to limit the possible scenarios associated to the retrieval implementation, it is necessary to take in consideration which criteria will be used for an efficient monitoring program, while clearly determining the performance reliability of the geotechnical barriers. In addition, the integrity of the host rock as geological barrier has to be verified. Therefore, it is important to evaluate different design solutions and the most appropriate measurement methods to improve the retrievability process of wastes from a geological repository. A short presentation of the host rocks is given is this paper.

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

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)

The Geologic and Hydrogeologic Setting of the Waste Isolation Pilot Plant

International Nuclear Information System (INIS)

Swift, P.N.; Corbet, T.F.

1999-01-01

The Waste Isolation Pilot Plant (WIPP) is a mined repository constructed by the US Department of Energy for the permanent disposal of transuranic wastes generated since 1970 by activities related to national defense. The WIPP is located 42 km east of Carlsbad, New Mexico, in bedded salt (primarily halite) of the Late Permian (approximately 255 million years old) Salado Formation 655 m below the land surface. Characterization of the site began in the mid-1970s. Construction of the underground disposal facilities began in the early 1980s, and the facility received final certification from the US Environmental Protection Agency in May 1998. Disposal operations are planned to begin following receipt of a final permit from the State of New Mexico and resolution of legal issues. Like other proposed geologic repositories for radioactive waste, the WIPP relies on a combination of engineered and natural barriers to isolate the waste from the biosphere. Engineered barriers at the WIPP, including the seals that will be emplaced in the access shafts when the facility is decommissioned, are discussed in the context of facility design elsewhere in this volume. Physical properties of the natural barriers that contribute to the isolation of radionuclides are discussed here in the context of the physiographic, geologic, and hydrogeologic setting of the site

Technical support for GEIS: radioactive waste isolation in geologic formations. Volume 2. Commercial waste forms, packaging and projections for preconceptual repository design studies

Energy Technology Data Exchange (ETDEWEB)

1978-04-01

This volume, Y/OWI/TM-36/2, ''Commercial Waste Forms, Packaging and Projections for Preconceptual Repository Design Studies,'' is one of a 23-volume series, ''Technical Support for GEIS: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-36, which supplements the ''Contribution to Draft Generic Environmental Impact Statement on Commercial Waste Management: Radioactive Waste Isolation in Geologic Formations,'' Y/OWI/TM-44. The series provides a more complete technical basis for the preconceptual designs, resource requirements, and environmental source terms associated with isolating commercial LWR wastes in underground repositories in salt, granite, shale and basalt. Wastes are considered from three fuel cycles: uranium and plutonium recycling, no recycling of spent fuel and uranium-only recycling. This volume contains the data base for waste forms, packages, and projections from the commercial waste defined by the Office of Waste Isolation in ''Nuclear Waste Projections and Source Term Data for FY 1977,'' Y/OWI/TM-34. Also, as an alternative data base for repository design and analysis, waste forms, packages, and projections for commercial waste defined by Battelle Pacific Northwest Laboratory (BPNL) have been included. This data base consists of a reference case for use in the alternative design study and a definition of combustible wastes for use in mine fire and hydrogen generation analyses.

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

The use of laboratory adsorption data and models to predict radionuclide releases from a geological repository: A brief history

International Nuclear Information System (INIS)

Langmuir, D.

1997-01-01

Radionuclide (RN) adsorption has long been recognized as important to assure the isolation of nuclear wastes in a geological repository. Laboratory measured RN adsorption data have generally been expressed as distribution coefficient (K d ) values or adsorption isotherms. The surface complexation (SC) adsorption models were introduced in the late 1970''s. The best known of these models incorporate electrical double layer (EDL) theory. Their use requires that the water chemistry and surface properties of adsorbing rocks and minerals be fully characterized. Because the SC models are relatively mechanistic, they may allow extrapolation of adsorption results to repository conditions that lie outside the limited experimental range used to parameterize a given model. Turner has shown that the diffuse layer model (the simplest SC model) fits a wide range of RN adsorption data as well as the more complex models. Others have suggested ways to generalize and estimate SC model parameters for a variety of minerals, rocks and engineered materials. Degueldre and Werlni and Degueldre et al. have proposed a simplified SC model for RN adsorption that avoids EDL theory, in which the adsorption of RN species is estimated from linear free energy relationships. It is appropriate to ask how accurately RN adsorption behavior must be known or understood for total system performance analysis (TSPA). In most geological settings now being considered for repository development globally, it may suffice to select bounding K d values for the different rock types. Use of the SC models to describe RN adsorption can provide one with increased confidence that minimum K d ''s and the distribution of K d values the author might propose for TSPA are in fact conservative. 68 refs., 5 figs., 1 tab

Systems study of the feasibility of high-level nuclear waste fractionation for thermal stress control in a geologic repository: appendices

International Nuclear Information System (INIS)

McKee, R.W.; Elder, H.K.; McCallum, R.F.; Silviera, D.J.; Swanson, J.L.; Wiles, L.E.

1983-06-01

This study assesses the benefits and costs of fractionating the cesium and strontium (Cs/Sr) components in commercial high-level waste (HLW) to a separate waste stream for the purpose of reducing geologic-repository thermal stresses in the region of the HLW. The major conclusion is that the Cs/Sr fractionation concept offers the prospect of a substantial total system cost advantage for HLW disposal if reduced HLW package temperatures in a basalt repository are desired. However there is no cost advantage if currently designated maximum design temperatures are acceptable. Aging the HLW for 50 to 100 years can accomplish similar results at equivalent or lower costs. Volume II contains appendices for: (1) thermal analysis supplement; (2) fractionation process experimental results supplement; (3) cost analysis supplement; and (4) radiological risk analysis supplement

Development of the methodology on priority of element-specific biosphere parameters for geological disposal applicable to any proposed repository site

International Nuclear Information System (INIS)

Kato, Tomoko; Ohi, Takao; Suzuki, Yuji

2009-01-01

It is difficult to acquire all of biosphere parameters for geological disposal at the repository site because several hundreds of the parameters have to be dealt with in one calculation case of the biosphere assessment. Before site-specific activities, it is important to develop the data acquisition methodology of biosphere parameters applicable to any proposed repository site. The methodology for identification of the priority of the parameters was developed for the effective data acquisition of biosphere parameters at the site. First of all, flow diagram was constructed to evaluate the availability of the existing generic biosphere dataset. It was found to be effective for the data acquisition at the site to focus on the element-specific parameters with the existing dataset. Secondly, the priority of the data acquisition was identified for element-specific parameters at the site, with considering the variation of dose rate by combining the significant element-specific parameters. The availability of the existing generic biosphere dataset and the priority on data acquisition were identified for the element-specific parameters of key radionuclides in the safety assessment of geological disposal that should be acquired at the site. This priority list would be useful for effective data acquisition at the site. (author)

Reliable predictions of waste performance in a geologic repository

International Nuclear Information System (INIS)

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

1985-08-01

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

Geotechnical and geological aspects for repository concepts with retrievability of radioactive waste; Geotechnische und geologische Aspekte fuer Tiefenlagerkonzepte mit der Option der Rueckholung der radioaktiven Reststoffe

Energy Technology Data Exchange (ETDEWEB)

Stahlmann, Joachim; Leon Vargas, Rocio; Mintzlaff, Volker [Technische Univ. Braunschweig (Germany). Inst. fuer Grundbau und Bodenmechanik

2016-03-15

The retrievability of heat-producing high-level radioactive waste (HAW) is on debate internationally as well as in Germany. This article deals with the geological and geotechnical consequences of the design of a repository with retrievability in different host rocks. The properties of rock salt, clay, shale and crystalline rock - potential host rocks for a repository with retrievability in Germany - will be presented. Based on these properties generic models of repositories with measurements for retrievability and monitoring will be also presented. With these models it can be derived that due the different stress-deformation-behavior there is a conflict of aims between the best possible closure of the waste and the option of retrieval.

Postclosure risks of alternative SRP nuclear waste forms in geologic repositories

International Nuclear Information System (INIS)

Cheung, H.; Edwards, L.; Harvey, T.; Revelli, M.

1982-05-01

The postclosure risk of REFERENCE and ALTERNATIVE waste forms for the defense high-level waste at the Savannah River Plant (SRP) were compared by analyses with a computer code, MISER, written to study the effects of repository features in a probabilistic framework. MISER traces radionuclide flows through a network of stream tubes from the repository to risk-sensitive points. Uncertainties in waste form, package properties, and geotechnical data are accounted for with Monte Carlo techniques. Our results show: (1) for generic layered-salt and basalt repositories, the difference in performance between the two waste forms is insignificant; (2) where the doses are sensitive to uncertainties in leaching rates, the doses are orders of magnitude below background; (3) disruptive events contribute only slightly to the risk of a layered-salt repository; (4) simple design alterations have strong effects on near field doses; (5) great care should be exercised in selecting the location at which repository risks are to be measured, calculated, or regulated

Development of an object-oriented simulation code for repository performance assessment

International Nuclear Information System (INIS)

Tsujimoto, Keiichi; Ahn, J.

1999-01-01

As understanding for mechanisms of radioactivity confinement by a deep geologic repository improves at the individual process level, it has become imperative to evaluate consequences of individual processes to the performance of the whole repository system. For this goal, the authors have developed a model for radionuclide transport in, and release from, the repository region by incorporating multiple-member decay chains and multiple waste canisters. A computer code has been developed with C++, an object-oriented language. By utilizing the feature that a geologic repository consists of thousands of objects of the same kind, such as the waste canister, the repository region is divided into multiple compartments and objects for simulation of radionuclide transport. Massive computational tasks are distributed over, and executed by, multiple networked workstations, with the help of parallel virtual machine (PVM) technology. Temporal change of the mass distribution of 28 radionuclides in the repository region for the time period of 100 million yr has been successfully obtained by the code

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)

Analysis of the seismic hazard to an underground waste repository

International Nuclear Information System (INIS)

Wight, L.H.

1979-01-01

Conclusions are: The consequence associated with intense vibratory shaking of a well-designed repository is essentially negligible. The specification of an appropriate seismic vibratory design criteria could best be accomplished with a Bayesian seismic hazard assessment, using geologic slip rates as input. The consequence associated with fault displacement is very site specific and dependent on the host geologic media and its permeability changes in response to fault displacement. The probability of faulting through a repository in its million year design life is rather high, principally because of a high probability of primary or secondary faulting on undetected faults. The faulting probability can be minimized by deploying sophisticated site certification programs. High resolution microseismic surveillance seems to be most appropriate. The author's judgement is that the repository simulation program can neglect consequences associated with shaking of the repository, but that the probability of significant fault displacement through the repository during its design life should be conservatively taken as one

Geological disposal of radioactive wastes: national commitment, local and regional involvement. A Collective Statement of the OECD Nuclear Energy Agency 'Radioactive Waste Management Committee', adopted March 2011

International Nuclear Information System (INIS)

2012-01-01

Disposal in engineered facilities built in stable, deep geological formations is the reference solution for permanently isolating long-lived radioactive waste from the human biosphere. This management method is designed to be intrinsically safe and final, i.e. not dependent on human presence and intervention in order to fulfil its safety goal. Siting waste repositories brings up a range of issues that touch on scientific knowledge, technical capacity, ethical values, territorial planning, community well-being, and more. Bringing to fruition the multi-decades task of siting and developing a repository demands a strong national commitment and a significant regional and local involvement. This Collective Statement by the Radioactive Waste Management Committee of the OECD Nuclear Energy Agency recognizes the advances made toward greater transparency and dialogue among the diverse relevant stakeholders and identifies the fundamental ingredients needed to support national commitment and foster territorial involvement. It concludes that technical and societal partners can develop shared confidence in the safety of geological repositories and jointly carry these projects forward

Geological disposal of radioactive waste: national commitment, local and regional involvement - A Collective Statement of the OECD Nuclear Energy Agency Radioactive Waste Management Committee Adopted March 2012

International Nuclear Information System (INIS)

2012-01-01

Disposal in engineered facilities built in stable, deep geological formations is the reference solution for permanently isolating long-lived radioactive waste from the human biosphere. This management method is designed to be intrinsically safe and final, meaning that it is not dependent on human presence or intervention in order to fulfil its safety goal. Selecting the site of a waste repository brings up a range of issues involving scientific knowledge, technical capacity, ethical values, territorial planning, community well-being and more. Bringing to fruition the multi-decade task of siting and developing a repository demands a strong national commitment and significant regional and local involvement. This collective statement by the Radioactive Waste Management Committee of the OECD Nuclear Energy Agency recognises the advances made towards greater transparency and dialogue among the diverse stakeholders concerned and identifies the fundamental elements needed to support national commitment and to foster territorial involvement. It concludes that technical and societal partners can develop shared confidence in the safety of geological repositories and jointly carry these projects forward [fr

Development of the JNC geological disposal technical information integration system subjected for repository design and safety assessment

International Nuclear Information System (INIS)

Ishihara, Yoshinao; Ito, Takashi; Kobayashi, Shigeki; Neyama, Atsushi

2004-02-01

On this work, system manufacture about disposal technology and safety assessment field was performed towards construction of the JNC Geological Disposal Technical Information Integration System which systematized three fields of technical information acquired in investigation (site characteristic investigation) of geology environmental conditions, disposal technology (design of deep repository), and performance/safety assessment. The technical information database managed focusing on the technical information concerning individual research of an examination, analysis, etc. and the parameter set database managed focusing on the set up data set used in case of comprehensive evaluation are examined. In order to support and promote share and use of the technical information registered and managed by the database, utility functions, such as a technical information registration function, technical information search/browse function, analysis support function, and visualization function, are considered, and the system realized in these functions is built. The built system is installed in the server of JNC, and the functional check examination is carried out. (author)

Geologic simulation model for a hypothetical site in the Columbia Plateau

International Nuclear Information System (INIS)

Petrie, G.M.; Zellmer, J.T.; Lindberg, J.W.; Foley, M.G.

1981-04-01

This report describes the structure and operation of the Assessment of Effectiveness of Geologic Isolation Systems (AEGIS) Geologic Simulation Model, a computer simulation model of the geology and hydrology of an area of the Columbia Plateau, Washington. The model is used to study the long-term suitability of the Columbia Plateau Basalts for the storage of nuclear waste in a mined repository. It is also a starting point for analyses of such repositories in other geologic settings. The Geologic Simulation Model will aid in formulating design disruptive sequences (i.e. those to be used for more detailed hydrologic, transport, and dose analyses) from the spectrum of hypothetical geological and hydrological developments that could result in transport of radionuclides out of a repository. Quantitative and auditable execution of this task, however, is impossible without computer simulation. The computer simulation model aids the geoscientist by generating the wide spectrum of possible future evolutionary paths of the areal geology and hydrology, identifying those that may affect the repository integrity. This allows the geoscientist to focus on potentially disruptive processes, or series of events. Eleven separate submodels are used in the simulation portion of the model: Climate, Continental Glaciation, Deformation, Geomorphic Events, Hydrology, Magmatic Events, Meteorite Impact, Sea-Level Fluctuations, Shaft-Seal Failure, Sub-Basalt Basement Faulting, and Undetected Features. Because of the modular construction of the model, each submodel can easily be replaced with an updated or modified version as new information or developments in the state of the art become available. The model simulates the geologic and hydrologic systems of a hypothetical repository site and region for a million years following repository decommissioning. The Geologic Simulation Model operates in both single-run and Monte Carlo modes

Deep geological radioactive waste disposal in Germany: Lessons learned and future perspectives

International Nuclear Information System (INIS)

Lempert, J.P.; Biurrun, E.

2001-01-01

As far back as in the seventies a fully developed, integrated concept for closing the nuclear fuel cycle was agreed upon in Germany between the Federal Government of that time and the electricity utilities. In the twenty years elapsed since then it was further developed as necessary to permanently fit the state of the art of science and technology. For management of spent fuel, the concept currently considers two equivalent alternatives: direct disposal of the spent fuel or reprocessing the fuel and recycling in thermal reactors. Interim storage of spent fuel and vitrified high level waste (HLW) to allow for decay heat generation to decrease to a convenient level is carried out in centralized installations. Radioactive waste disposal in pursuant to German regulations for all kinds of waste is to be carried out exclusively in deep geologic repositories. At present in the country, there are three centralized interim storage facilities for spent fuel, one of them can also accept vitrified HLW. Several facilities are in use for low level waste (LLW) and intermediate level waste (ILW) storage at power plants and other locations. A pilot conditioning facility for encapsulating spent fuel and/or HLW for final disposal is now ready to be commissioned. Substantial progress has been achieved in realization of HLW disposal, including demonstration of all the needed technology and fabrication of a significant part of the equipment. With regard to deep geologic disposal of LLW and ILW, Germany has worldwide unique experience. The Asse salt mine was used as an experimental repository for some 10 years in the late sixties and seventies. After serving since then as an underground research facility, it is now being backfilled and sealed. The Morsleben deep geologic repository was in operation for more than 25 years until September 1998. (author)

Potential role of ABC-assisted repositories in U.S. plutonium and high-level waste disposition

Energy Technology Data Exchange (ETDEWEB)

Berwald, D.; Favale, A.; Myers, T. [Grumman Aerospace Corporation, Bethpage, NY (United States)] [and others

1995-10-01

This paper characterizes the issues involving deep geologic disposal of LWR spent fuel rods, then presents results of an investigation to quantify the potential role of Accelerator-Based Conversion (ABC) in an integrated national nuclear materials and high level waste disposition strategy. The investigation used the deep geological repository envisioned for Yucca Mt., Nevada as a baseline and considered complementary roles for integrated ABC transmutation systems. The results indicate that although a U.S. geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of plutonium, the minor actinides, and selected long-lived fission products can result in the following substantial benefits: plutonium burndown to near zero levels, a dramatic reduction of the long term hazard associated with geologic repositories, an ability to place several-fold more high level nuclear waste in a single repository, electricity sales to compensate for capital and operating costs.

Assessment of effectiveness of geologic isolation systems. Test case release consequence analysis for a spent fuel repository in bedded salt

International Nuclear Information System (INIS)

Raymond, J.R.; Bond, F.W.; Cole, C.R.; Nelson, R.W.; Reisenauer, A.E.; Washburn, J.F.; Norman, N.A.; Mote, P.A.; Segol, G.

1980-01-01

Geologic and geohydrologic data for the Paradox Basin have been used to simulate movement of ground water and radioacrtive contaminants from a hypothetical nuclear reactor spent fuel repository after an assumed accidental release. The pathlines, travel times and velocity of the ground water from the repository to the discharge locale (river) were determined after the disruptive event by use of a two-dimensional finite difference hydrologic model. The concentration of radioactive contaminants in the ground water was calculated along a series of flow tubes by use of a one-dimensional mass transport model which takes into account convection, dispersion, contaminant/media interactions and radioactive decay. For the hypothetical site location and specific parameters used in this demonstration, it is found that Iodine-129 (I-129) is tthe only isotope reaching the Colorado River in significant concentration. This concentration occurs about 8.0 x 10 5 years after the repository has been breached. This I-129 ground-water concentration is about 0.3 of the drinking water standard for uncontrolled use. The groundwater concentration would then be diluted by the Colorado River. None of the actinide elements reach more than half the distance from the repository to the Colorado River in the two-million year model run time. This exercise demonstrates that the WISAP model system is applicable for analysis of contaminant transport. The results presented in this report, however, are valid only for one particular set of parameters. A complete sensitivity analysis must be performed to evaluate the range of effects from the release of contaminants from a breached repository

Conceptual design of repository facilities

International Nuclear Information System (INIS)

Beale, H.; Engelmann, H.J.; Souquet, G.; Mayence, M.; Hamstra, J.

1980-01-01

As part of the European Economic Communities programme of research into underground disposal of radioactive wastes repository design studies have been carried out for application in salt deposits, argillaceous formations and crystalline rocks. In this paper the design aspects of repositories are reviewed and conceptual designs are presented in relation to the geological formations under consideration. Emphasis has been placed on the disposal of vitrified high level radioactive wastes although consideration has been given to other categories of radioactive waste

Evaluation of repository safety

Energy Technology Data Exchange (ETDEWEB)

Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S. [Center for Nuclear Waste Regulatory Analyses, San Antonio (United States)

2002-07-01

The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes

Evaluation of repository safety

International Nuclear Information System (INIS)

Sagar, B.; Patrick, W.; Dasgupta, B.; Mohanty, S.

2002-01-01

The United States high-level waste program requires evaluation of radiological safety during two distinct time intervals. The first interval, commonly referred to as the preclosure period, deals with receipt of waste at the site, transfer into disposal containers, if needed, emplacement in the underground openings, monitoring and maintenance activities, backfill and closure of the underground openings, and decontamination and decommissioning of the surface facilities of the geologic repository. The preclosure period may extend from a few tens of years to as long as a few hundred of years, depending on repository design and societal norms regarding a final decision to permanently seal the repository. During the preclosure or operational period, performance confirmation studies are conducted to provide a basis for updating and reevaluating estimates of postclosure performance and, finally, to provide a basis for a closure decision. The postclosure period during which expected repository performance must meet certain standards may range from ten thousands years, as it does in the United States, to millions of years, as it does in some European nations. Waste handling operations in the preclosure period are to be evaluated in relation to their potential effect on workers, members of general public, and the general environment. During this period, releases of radioactivity are to be monitored and appropriate actions taken whenever established limits are approached or exceeded. Preclosure safety is highly dependent on facility design, operational hardware and automated systems, operational sequences, and reliability of humans involved in operations. Preclosure safety analyses conducted before operations begin play a major role in the design process, selection of equipment, and development of operational procedures. Because of the complexity, duration, and spatial scales of the operations, analyses are conducted using mathematical models implemented in computer codes

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

Impact of retrievability of repository design

International Nuclear Information System (INIS)

Heijdra, J.J.; Gaag, J. v.d.; Prij, J.

1995-01-01

In this paper the impact of the retrievability on the design of the repository will be handled. Retrievability of radioactive waste from a repository in geological formations has received increasing attention during recent years. It is obvious that this retrievability will have consequences in terms of mining engineering, safety and cost. The purpose of the present study is to evaluate cost consequences by comparing two extreme options for retrievable storage. (author). 6 refs., 3 figs

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

International Nuclear Information System (INIS)

Isherwood, D.

1979-12-01

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

Nuclear waste and a deep geological disposal facility

International Nuclear Information System (INIS)

Vokal, A.; Laciok, A.; Vasa, I.

2005-01-01

The paper presents a systematic analysis of the individual areas of research into nuclear waste and deep geological disposal with emphasis on the contribution of Nuclear Research Institute Rez plc to such efforts within international projects, specifically the EURATOM 6th Framework Programme. Research in the area of new advanced fuel cycles with focus on waste minimisation is based on EU's REDIMPACT project. The individual fuel cycles, which are currently studied within the EU, are briefly described. Special attention is paid to fast breeders and accelerator-driven reactor concepts associated with new spent fuel reprocessing technologies. Results obtained so far show that none even of the most advanced fuel cycles, currently under consideration, would eliminate the necessity to have a deep geological repository for a safe storage of residual radioactive waste. As regards deep geological repository barriers, the fact is highlighted that the safety of a repository is assured by complementary engineered and natural barriers. In order to demonstrate the safety of a repository, a deep insight must be gained into any and all of the individual processes that occur inside the repository and thus may affect radioactivity releases beyond the repository boundaries. The final section of the paper describes methods of radioactive waste conditioning for its disposal in a repository. Research into waste matrices used for radionuclide immobilisation is also highlighted. (author)

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.

Use of limited information in a license application to construct a repository

International Nuclear Information System (INIS)

McGarry, J.M. III; Echols, F.S.

1996-01-01

The purpose of this paper is to provide a rationale for the proposition that the Department of Energy's (DOE's) submittal of a license application (LA) for the construction of a geologic repository to the Nuclear Regulatory Commission (NRC) may be, and arguably must be, based on statutorily-limited site characterization data and design information. The Nuclear Waste Policy Act of 1982 (NWPA), as amended, is the controlling statute for the disposal of spent nuclear fuel in a licensed geologic repository. Applicable NRC regulations for the licensing of such a repository are found for the most part in 10 C.F.R. Part 60

Mined Geologic Disposal System Concept of Operations

International Nuclear Information System (INIS)

Heidt, R.M.

1995-01-01

A Concept of Operations has been developed for the disposal of high-level radioactive waste in the potential geologic repository at Yucca Mountain. The Concept of Operations has been developed to document a cormion understanding of how the repository is to be operated. It is based on the repository architecture identified in the Initial Summary Report for Repository/Waste Package Advanced Conceptual Design and describes the operation of the repository from the initial receipt of waste through repository closure. Also described are operations for waste retrieval

Overview of the United States' nuclear waste repository programme

International Nuclear Information System (INIS)

Surles, T.G.

2002-01-01

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

Selection of Corrosion Resistant Materials for Nuclear Waste Repositories

International Nuclear Information System (INIS)

R.B. Rebak

2006-01-01

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

Geotechnical materials considerations for conceptual repository design in the Palo Duro Basin, Texas

International Nuclear Information System (INIS)

Versluis, W.S.; Balderman, M.A.

1984-01-01

The Palo Duro Basin is only one of numerous potential repository locations for placement of a nuclear waste repository. Conceptual designs in the Palo Duro Basin involve considerations of the character and properties of the geologic materials found on several sites throughout the Basin. The first consideration presented includes current basin exploration results and interpretations of engineering properties for the basin geologic sequences. The next consideration presented includes identification of the characteristics of rock taken from the geologic sequence of interest through laboratory and field testing. Values for materials properties of representative samples are obtained for input into modeling of the material response to repository placement. Conceptual designs which respond to these geotechnical considerations are discussed. 4 references, 4 figures, 4 tables

Nuclear waste repository transparency technology test bed demonstrations at WIPP

International Nuclear Information System (INIS)

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

2000-01-01

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

The basic concept for the geological surveys

International Nuclear Information System (INIS)

Deguchi, Akira; Takahashi, Yoshiaki

1998-01-01

Before the construction of high level radioactive waste repository, the implementing entity will go through three siting stages for the repository. In each of those three stages, the implementing entity will carry out geological surveys. In this report, the concept for the geological surveys is described, on the basic of 'The policies for the high level radioactive waste disposal (a tentative draft)' issued by the Atomic Energy Commission in July, 1997. (author)

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

Low Level Waste Conceptual Design Adaption to Poor Geological Conditions

International Nuclear Information System (INIS)

Bell, J.; Drimmer, D.; Giovannini, A.; Manfroy, P.; Maquet, F.; Schittekat, J.; Van Cotthem, A.; Van Echelpoel, E.

2002-01-01

Since the early eighties, several studies have been carried out in Belgium with respect to a repository for the final disposal of low-level radioactive waste (LLW). In 1998, the Belgian Government decided to restrict future investigations to the four existing nuclear sites in Belgium or sites that might show interest. So far, only two existing nuclear sites have been thoroughly investigated from a geological and hydrogeological point of view. These sites are located in the North-East (Mol-Dessel) and in the mid part (Fleurus-Farciennes) of the country. Both sites have the disadvantage of presenting poor geological and hydrogeological conditions, which are rather unfavorable to accommodate a surface disposal facility for LLW. The underground of the Mol-Dessel site consists of neogene sand layers of about 180 m thick which cover a 100 meters thick clay layer. These neogene sands contain, at 20 m depth, a thin clayey layer. The groundwater level is quite close to the surface (0-2m) and finally, the topography is almost totally flat. The upper layer of the Fleurus-Farciennes site consists of 10 m silt with poor geomechanical characteristics, overlying sands (only a few meters thick) and Westphalian shales between 15 and 20 m depth. The Westphalian shales are tectonized and strongly weathered. In the past, coal seams were mined out. This activity induced locally important surface subsidence. For both nuclear sites that were investigated, a conceptual design was made that could allow any unfavorable geological or hydrogeological conditions of the site to be overcome. In Fleurus-Farciennes, for instance, the proposed conceptual design of the repository is quite original. It is composed of a shallow, buried concrete cylinder, surrounded by an accessible concrete ring, which allows permanent inspection and control during the whole lifetime of the repository. Stability and drainage systems should be independent of potential differential settlements an d subsidences

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)

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)

Deep geological disposal research in Argentina

International Nuclear Information System (INIS)

Ninci Martinez, Carlos A.; Ferreyra, Raul E.; Vullien, Alicia R.; Elena, Oscar; Lopez, Luis E.; Maloberti, Alejandro; Nievas, Humberto O.; Reyes, Nancy C.; Zarco, Juan J.; Bevilacqua, Arturo M.; Maset, Elvira R.; Jolivet, Luis A.

2001-01-01

Argentina shall require a deep geological repository for the final disposal of radioactive wastes, mainly high-level waste (HLW) and spent nuclear fuel produced at two nuclear power plants and two research reactors. In the period 1980-1990 the first part of feasibility studies and a basic engineering project for a radioactive high level waste repository were performed. From the geological point of view it was based on the study of granitic rocks. The area of Sierra del Medio, Province of Chubut, was selected to carry out detailed geological, geophysical and hydrogeological studies. Nevertheless, by the end of the eighties the project was socially rejected and CNEA decided to stop it at the beginning of the nineties. That decision was strongly linked with the little attention paid to social communication issues. Government authorities were under a strong pressure from social groups which demanded the interruption of the project, due to lack of information and the fear it generated. The lesson learned was: social communication activities shall be carried out very carefully in order to advance in the final disposal of HLW at deep geological repositories (author)

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.

Preliminary post-closure safety assessment of repository concepts for low level radioactive waste at the Bruce Site, Ontario

International Nuclear Information System (INIS)

Little, R.H.; Penfold, J.S.S.; Egan, M.J.; Leung, H.

2005-01-01

The preliminary post-closure safety assessment of permanent repository concepts for low-level radioactive waste (LLW) at the Ontario Power Generation (OPG) Bruce Site is described. The study considered the disposal of both short and long-lived LLW. Four geotechnically feasible repository concepts were considered (two near-surface and two deep repositories). An approach consistent with best international practice was used to provide a reasoned and comprehensive analysis of post-closure impacts of the repository concepts. The results demonstrated that the deep repository concepts in shale and in limestone, and the surface repository concept on sand should meet radiological protection criteria. For the surface repository concept on glacial till, it appears that increased engineering such as grouting of waste and voids should be considered to meet the relevant dose constraint. Should the project to develop a permanent repository for LLW proceed, it is expected that this preliminary safety assessment would need to be updated to take account of future site-specific investigations and design updates. (author)

Stream-simulation experiments for waste-repository investigations

International Nuclear Information System (INIS)

Seitz, M.G.

1980-01-01

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

Regulatory status on the safety assessment of a HLW repository in other countries

International Nuclear Information System (INIS)

Lee, Sung Ho; Hwang, Yong Soo

2008-12-01

To construct a HLW repository, it is essential to meet the requirements on the regulation for a deep geological disposal. Even if the construction of a HLW repository is determined positively, technical standards which assert the performance of a repository will be needed. Among various technical standards, safety assessment based on the repository evolution in the future will play an important role in the licensing process. The foreign countries' technical standards on the safety assessment of a HLW repository may be an indicator to carry out the R and D activities on geological disposal effectively. In this report, assessment period, limit of radiation dose and uncertainty related to the safety assessment are investigated and analyzed in detail. Especially, the technical reviews of USA regulation bodies seems to be reasonable in the point of the intrinsic attribute of safety assessment

A compound power-law model for volcanic eruptions: Implications for risk assessment of volcanism at the proposed nuclear waste repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ho, Chih-Hsiang

1994-01-01

Much of the ongoing debate on the use of nuclear power plants in U.S.A. centers on the safe disposal of the radioactive waste. Congress, aware of the importance of the waste issue, passed the Nuclear Waste Policy Act of 1982, requiring the federal government to develop a geologic repository for the permanent disposal of high level radioactive wastes from civilian nuclear power plants. The Department of Energy (DOE) established the Office of Civilian Radioactive Waste Management (OCRWM) in 1983 to identify potential sites. When OCRWM had selected three potential sites to study, Congress enacted the Nuclear Waste Policy Amendments Act of 1987, which directed the DOE to characterize only one of those sites, Yucca Mountain, in southern Nevada. For a site to be acceptable, theses studies must demonstrate that the site could comply with regulations and guidelines established by the federal agencies that will be responsible for licensing, regulating, and managing the waste facility. Advocates and critics disagree on the significance and interpretation of critical geological features which bear on the safety and suitability of Yucca Mountain as a site for the construction of a high-level radioactive waste repository. Recent volcanism in the vicinity of Yucca Mountain is readily recognized as an important factor in determining future public and environmental safety because of the possibility of direct disruption of a repository site by volcanism. In particular, basaltic volcanism is regarded as direct and unequivocal evidence of deep-seated geologic instability. In this paper, statistical analysis of volcanic hazard assessment at the Yucca Mountain site is discussed, taking into account some significant geological factors raised by experts. Three types of models are considered in the data analysis. The first model assumes that both past and future volcanic activities follow a homogeneous Poisson process (HPP)

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

International Nuclear Information System (INIS)

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

2009-01-01

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

A Socio-Technical Perspective on Repository Monitoring - 12229

Energy Technology Data Exchange (ETDEWEB)

Bergmans, Anne [University of Antwerp, Faculty of Political and Social Sciences, Sint-Jacobstraat 2, 2000 Antwerpen (Belgium); Elam, Mark; Sundqvist, Goeran [University of Gothenburg, Department of Sociology, Box 720, 40530 Gothenburg (Sweden); Simmons, Peter [University of East Anglia, School of Environmental Sciences, Norwich NR4 7TJ (United Kingdom)

2012-07-01

Monitoring geological repositories for high-activity radioactive wastes has both technical and social dimensions, which are closely interrelated. To investigate the implications of this for geological disposal, data on experts' expectations of repository monitoring and the functions that it is expected to serve were analysed. The analysis drew on strategic and technical documents on monitoring produced by national agencies and by international organisations or projects; interviews with specialists in radioactive waste management organisations on monitoring and on their perceptions of societal concerns and expectations; and observations from technical workshops on repository monitoring. Three main rationales for monitoring were found: performance confirmation; decision support in a step-wise process; and public and stakeholder confidence building. The expectation that monitoring will enhance public confidence is then examined from a social scientific perspective and the potential for and challenges to using monitoring in this way are reviewed. In conclusion, implications for stakeholder engagement in the development of monitoring objectives and strategies are discussed. (authors)

Repository Technology Program: Technical progress report for the period May 29, 1986--June 30, 1987

International Nuclear Information System (INIS)

1988-10-01

This document reports the progress made in the 13-month period from May 29, 1986--June 30, 1987, on the development of a second geologic repository in rocks other than those being considered for a first repository. Subsequent periods will be covered in reports to be issued on a semiannual basis. The reporting elements are arranged by the work breakdown structure so that related studies are presented together. The studies are reported by the Office of Waste Technology Development (OWTD), a prime contractor of the US. Department of Energy (DOE) Repository Technology Program (RTP) Office in the Repository Technology and Transportation Division (RTTD) of the Office of Geologic Repositories (OGR). The studies include work by other DOE prime contractors and by contractors to the OWTD. 50 refs

A methodology of uncertainty/sensitivity analysis for PA of HLW repository learned from 1996 WIPP performance assessment

International Nuclear Information System (INIS)

Lee, Y. M.; Kim, S. K.; Hwang, Y. S.; Kang, C. H.

2002-01-01

The WIPP (Waste Isolation Pilot Plant) is a mined repository constructed by the US DOE for the permanent disposal of transuranic (TRU) wastes generated by activities related to defence of the US since 1970. Its historical disposal operation began in March 1999 following receipt of a final permit from the State of NM after a positive certification decision for the WIPP was issued by the EPA in 1998, as the first licensed facility in the US for the deep geologic disposal of radioactive wastes. The CCA (Compliance Certification Application) for the WIPP that the DOE submitted to the EPA in 1966 was supported by an extensive Performance Assessment (PA) carried out by Sandia National Laboratories (SNL), with so-called 1996 PA. Even though such PA methodologies could be greatly different from the way we consider for HLW disposal in Korea largely due to quite different geologic formations in which repository are likely to be located, a review on lots of works done through the WIPP PA studies could be the most important lessons that we can learn from in view of current situation in Korea where an initial phase of conceptual studies on HLW disposal has been just started. The objective of this work is an overview of the methodology used in the recent WIPP PA to support the US DOE WIPP CCA ans a proposal for Korean case

Impacts of new developments in partitioning and transmutation on the disposal of high-level nuclear waste in a mined geologic repository

International Nuclear Information System (INIS)

Ramspott, L.D.; Jor-Shan Choi; Halsey, W.; Pasternak, A.; Cotton, T.; Burns, J.; McCabe, A.; Colglazier, W.; Lee, W.W.L.

1992-03-01

During the 1970s, the United States and other countries thoroughly evaluated the options for the safe and final disposal of high-level radioactive wastes (HLW). The worldwide scientific community concluded that deep geologic disposal was clearly the most technically feasible alternative. They also ranked the partitioning and transmutation (P-T) of radionuclides among the least favored options. A 1982 report by the International Atomic Energy Agency summarized the key reasons for that ranking: ''Since the long-term hazards are already low, there is little incentive to reduce them further by P-T. Indeed the incremental costs of introducing P-T appear to be unduly high in relation to the prospective benefits.'' Recently, the delays encountered by the US geologic disposal program for HLW, along with advanced in the development of P-T concepts, have led some to propose P-T as a means of reducing the long-term risks from the radioactive wastes that require disposal and thus making it easier to site, license, and build a geologic repository. This study examines and evaluates the effects that introducing P-T would have on the US geologic disposal program

Canadian geologic isolation program

International Nuclear Information System (INIS)

Dyne, P.J.

1976-01-01

The Canadian geologic isolation program is directed at examining the potential of (1) salt deposits and (2) hard rock as repositories for radioactive wastes. It was felt essential from the inception that alternative host rocks be evaluated over a fairly large geographical area. The studies on salt deposits to date are based on existing geological information and have identified the areas that show some potential and merit further study. The factors considered include depth, thickness and purity of the deposit, overlying aquifers, and the potential for gas and oil exploration as well as potash recovery. The studies on hard rock are restricted to plutonic igneous rocks in the Ontario part of the Canadian Shield. Because geological information on their nature and extent is sparse, the study is limited to bodies that are well exposed and for which information is available.for which information is available. Field studies in the next two seasons are aimed at mapping the fault and joint patterns and defining the geologic controls on their development. In 1977 and 1978, two or three of the more favorable sites will be mapped in greater detail, and an exploratory drilling program will be established to determine the extent of fracturing at depth and the hydrology of these fractures. Conceptual designs of mined repositories in hard rock are also being made with the hope of identifying, at an early stage in this program, special problems in hard-rock repositories that may require development and study

Coupled thermo-hydro-mechanical processes associated with a radioactive waste repository

International Nuclear Information System (INIS)

Tsang, C.F.

1988-01-01

The performance assessment of a nuclear waste geologic repository presents a scientific and technical problem of a scope far beyond the evaluation of most civil and geologic constructions. First performance prediction must be made for tens of thousands of years, and a secondly, in calculating potential leakage rates from a repository to the biosphere the authors must determine not only the mean or average travel time but also the shorter travel times of low concentrations. These two criteria demand an understanding of all significant physical and chemical processes likely to occur around a nuclear waste repository. In particular, processes coupling thermal transfer fluid flow, mechanical deformation and chemical reactors, which may be slow in a laboratory time scale, may become very important. This paper gives a general survey on the subject, with specific examples of a number of relevant coupled thermo-hydro-mechanical processes associated with nuclear waste repository

Report of early site suitability evaluation of the potential repository site at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Younker, J.L.; Andrews, W.B.; Fasano, G.A.; Herrington, C.C.; Mattson, S.R.; Murray, R.C.; Ballou, L.B.; Revelli, M.A.; Ducharme, A.R.; Shephard, L.E.; Dudley, W.W.; Hoxie, D.T.; Herbst, R.J.; Patera, E.A.; Judd, B.R.; Docka, J.A.; Rickertsen, L.D.

1992-01-01

This study evaluated the technical suitability of Yucca Mountain, Nevada, as a potential site for a mined geologic repository for the permanent disposal of radioactive waste. The evaluation was conducted primarily to determine early in the site characterization program if there are any features or conditions at the site that indicate it is unsuitable for repository development. A secondary purpose was to determine the status of knowledge in the major technical areas that affect the suitability of the site. This early site suitability evaluation (ESSE) was conducted by a team of technical personnel at the request of the Associate Director of the US Department of Energy (DOE) Office of Geologic Disposal, a unit within the DOE's Office of Civilian Radioactive Waste Management. The Yucca Mountain site has been the subject of such evaluations for over a decade. In 1983, the site was evaluated as part of a screening process to identify potentially acceptable sites. The site was evaluated in greater detail and found suitable for site characterization as part of the Environmental Assessment (EA) (DOE, 1986) required by the Nuclear Waste Policy Act of 1982 (NWPA). Additional site data were compiled during the preparation of the Site Characterization Plan (SCP) (DOE, 1988a). This early site suitability evaluation has considered information that was used in preparing both-documents, along with recent information obtained since the EA and SCP were published. This body of information is referred to in this report as ''current information'' or ''available evidence.''

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

Report to Congress on the potential use of lead in the waste packages for a geologic repository at Yucca Mountain, Nevada

Energy Technology Data Exchange (ETDEWEB)

NONE

1989-12-01

In the Report of the Senate Committee on Appropriations accompanying the Energy and Water Appropriation Act for 1989, the Committee directed the Department of Energy (DOE) to evaluate the use of lead in the waste packages to be used in geologic repositories for spent nuclear fuel and high-level waste. The evaluation that was performed in response to this directive is presented in this report. This evaluation was based largely on a review of the technical literature on the behavior of lead, reports of work conducted in other countries, and work performed for the waste-management program being conducted by the DOE. The initial evaluation was limited to the potential use of lead in the packages to be used in the repository. Also, the focus of this report is post closure performance and not on retrievability and handling aspects of the waste package. 100 refs., 8 figs., 15 tabs.

Report to Congress on the potential use of lead in the waste packages for a geologic repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

1989-12-01

In the Report of the Senate Committee on Appropriations accompanying the Energy and Water Appropriation Act for 1989, the Committee directed the Department of Energy (DOE) to evaluate the use of lead in the waste packages to be used in geologic repositories for spent nuclear fuel and high-level waste. The evaluation that was performed in response to this directive is presented in this report. This evaluation was based largely on a review of the technical literature on the behavior of lead, reports of work conducted in other countries, and work performed for the waste-management program being conducted by the DOE. The initial evaluation was limited to the potential use of lead in the packages to be used in the repository. Also, the focus of this report is post closure performance and not on retrievability and handling aspects of the waste package. 100 refs., 8 figs., 15 tabs

Suggestions on selection of clay site as a key alternative of underground repository for HLW geological disposal in China

International Nuclear Information System (INIS)

Zheng Hualing; Fu Bingjun; Fan Xianhua; Chen Shi; Sun Donghui

2006-01-01

Site selection for the underground repository is a vital problem with respect to the HLW geological disposal. Over the past decades, we have been focusing our attention on granite as a priority in China. However, there are some problems have to be discussed on this matter. In this paper, both experiences gained and lessons learned in the international community regarding the site selection are described. And then, after analyzing a lot of some key factors affecting the site selection, some comments and suggestions on selection of clay site as a key alternative before final decision making in China are presented. (authors)

Two factors important to the criticality potential of spent fuel in geologic repositories

International Nuclear Information System (INIS)

Gore, B.F.; Jenquin, U.P.

1981-02-01

Two factors important to the criticality potential of spent fuel in geologic repositories are: the residual fissile content of the fuel, and the extent to which geochemical processes might somehow separate and accumulate plutonium from other spent fuel materials. This paper presents the results of two calculational surveys defining conditions required for criticality. In the first, homogeneous spherical mixtures of spent fuel actinide oxides and water with water reflection are analyzed. Graphs of minimum critical mass vs duration of in-reactor exposure are presented. Parametric variations from a base case are explored, including the effects of initial enrichment, post exposure radioactive decay and addition of rock materials to the mixture. In the second study, homogeneous spherical mixtures devoid of water, containing plutonium and a neutronically optimized rock material, with a thick rock neutron reflector are analyzed. Graphs of Pu critical mass are presented as a function of concentration over the range from 2 to 100 g Pu/l. Parametric variations from a base case are explored, including effects of rock composition, 240 Pu content and uranium contamination of the plutonium

Radionuclide migration in geological formations

International Nuclear Information System (INIS)

Barbreau, A.; Heremans, R.; Skytte Jensen, B.

1980-01-01

Radioactive waste disposal into geological formation is based on the capacity of rocks to confine radioactivity for a long period of time. Radionuclide migration from the repository to the environment depends on different mechanisms and phenomena whose two main ones are groundwater flow and the retention and ion-exchange property of rocks. Many studies are underway presently in EEC countries concerning hydrodynamic characteristics of deep geological formations as well as in radionuclide retention capacity and modelling. Important results have already been achieved which show the complexity of some phenomena and further studies shall principally be developed taking into account real conditions of the repository and its environment

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

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.

Use of a United States mid-Pacific Island territory for a Pacific Island Repository System (PIRS): Extended summary

International Nuclear Information System (INIS)

Forsberg, C.W.

1987-08-01

The concept of using a mid-ocean island for a geologic high-level waste repository was investigated. The technical advantages include geographical isolation and near-infinite ocean dilution as a backup to repository geological waste isolation. The institutional advantages are reduced siting problems and the potential of creating an international waste repository. Establishment of international waste repository would allow cost sharing, aid US nonproliferation goals, and assure proper disposal of spent fuel from developing countries. The major uncertainties in this concept are rock conditions at waste disposal depths and costs. 13 refs., 2 tabs

Using geologic conditions and multiattribute decision analysis to determine the relative favorability of selected areas for siting a high-level radioactive waste repository

International Nuclear Information System (INIS)

Harrison, W.; Edgar, D.E.; Baker, C.H.

1988-05-01

A method is presented for determining the relative favorability of geologically complex areas for isolating high-level radioactive wastes. In applying the method to the northeastern region of the United States, seismicity and tectonic activity were the screening criteria used to divide the region into three areas of increasing seismotectonic risk. Criteria were then used to subdivide the area of lowest seismotectonic risk into six geologically distinct subareas including characteristics, surface-water and groundwater hydrology, potential human intrusion, site geometry, surface characteristics, and tectonic environment. Decision analysis was then used to identify the subareas most favorable from a geologic standpoint for further investigation, with a view to selecting a site for a repository. Three subareas (parts of northeastern Vermont, northern New Hampshire, and western Maine) were found to be the most favorable, using this method and existing data. However, because this study assessed relative geologic favorability, no conclusions should be drawn concerning the absolute suitability of individual subareas for high-level radioactive waste isolation. 34 refs., 7 figs., 20 tabs

Use of modeling in repository licensing

International Nuclear Information System (INIS)

McGarry, J.M. III; Echols, F.S.

1995-01-01

A review of the regulatory history of the Nuclear Regulatory Commission (NRC) regulations applicable to the licensing of a geologic repository, as well as a review of NRC administrative (licensing) decisions and federal case law, support the NRC's use of simplified models, in appropriate circumstances, which provide well-documented and reasonably conservative bounding assumptions, together with the use of expert judgement, natural analogues, and other aids to supplement available information, in reaching its reasonable assurance determination whether the public health and safety will be adequately protected if the Yucca Mountain, Nevada site should be licensed for development as a geologic repository. Specific examples are provided to assist the reader to better understand how such qualitative concepts as open-quote reasonable assurance close-quote, open-quote reasonably conservative close-quote, and open-quote adequate close-quote protection are used in an administrative context to resolve technical issues

Geological and rock mechanics aspects of the long-term evolution of a crystalline rock site

International Nuclear Information System (INIS)

Cosgrove, J.W.; Hudson, J.A.

2009-01-01

We consider the stability of a crystalline rock mass and hence the integrity of a radioactive waste repository contained therein by, firstly, identifying the geological evolution of such a site and, secondly, by assessing the likely rock mechanics consequences of the natural perturbations to the repository. In this way, the potency of an integrated geological-rock mechanics approach is demonstrated. The factors considered are the pre-repository geological evolution, the period of repository excavation, emplacement and closure, and the subsequent degradation and natural geological perturbations introduced by glacial loading. It is found that the additional rock stresses associated with glacial advance and retreat have a first order effect on the stress magnitudes and are likely to cause a radical change in the stress regime. There are many factors involved in the related geosphere stability and so the paper concludes with a systems diagram of the total evolutionary considerations before, during and after repository construction. (authors)

Geotechnical support and topical studies for nuclear waste geologic repositories: Annual report, Fiscal Year 1986

International Nuclear Information System (INIS)

1986-11-01

The multidisciplinary project was initiated in fiscal year 1986. It comprises two major interrelated parts: (1) Technical Assistance. This part of the project includes: (a) review of the progress of major projects in the DOE Office of Civilian Radioactive Waste Management Program and advise the Engineering and Geotechnology Division on significant technical issues facing each project; (b) analyze geotechnical data, reports, tests, surveys and plans for the different projects; (c) review and comment on major technical reports and other program documents such as site characterization plans and area characterization plans and (d) provide scientific and technical input at technical meetings. (2) Topical Studies. This activity comprises studies on scientific and technical topics, and issues of significance to in-situ testing, test analysis methods, and performance assessment of nuclear waste geologic repositories. The subjects of study were selected based on discussions with DOE staff. For fiscal year 1986, one minor and one major area of investigation were undertaken. The minor topic is a preliminary consideration and planning exercise for post-closure monitoring studies. The major topic, with subtasks involving various geoscience disciplines, is on the mechanical, hydraulic, geophysical and geochemical properties of fractures in geologic rock masses. The present report lists the technical reviews and comments made during the fiscal year and summarizes the technical progress of the topical studies

Postclosure safety assessment of a used fuel repository in sedimentary rock

International Nuclear Information System (INIS)

Gobien, M.; Garisto, F.; Hunt, N.; Kremer, E.

2014-01-01

The Nuclear Waste Management Organization (NWMO) is responsible for the implementation of Adaptive Phased Management (APM), the federally-approved plan for safe long-term management of Canada's used nuclear fuel. Under the APM plan, used nuclear fuel will ultimately be placed within a deep geological repository in a suitable rock formation. This paper summarizes an illustrative case study of the current multi-barrier design and postclosure safety of a deep geological repository in a hypothetical sedimentary Michigan Basin setting. The purpose of this postclosure safety assessment is to determine potential effects of the repository on the health and safety of persons and the environment. Results are compared against acceptance criteria established for the protection of persons and the environment from potential radiological and non-radiological hazards. (author)

Postclosure safety assessment of a used fuel repository in sedimentary rock

Energy Technology Data Exchange (ETDEWEB)

Gobien, M.; Garisto, F.; Hunt, N.; Kremer, E. [Nuclear Waste Management Organization, Toronto, ON (Canada)

2014-07-01

The Nuclear Waste Management Organization (NWMO) is responsible for the implementation of Adaptive Phased Management (APM), the federally-approved plan for safe long-term management of Canada's used nuclear fuel. Under the APM plan, used nuclear fuel will ultimately be placed within a deep geological repository in a suitable rock formation. This paper summarizes an illustrative case study of the current multi-barrier design and postclosure safety of a deep geological repository in a hypothetical sedimentary Michigan Basin setting. The purpose of this postclosure safety assessment is to determine potential effects of the repository on the health and safety of persons and the environment. Results are compared against acceptance criteria established for the protection of persons and the environment from potential radiological and non-radiological hazards. (author)

Overview of adaptive phased management repository design development

International Nuclear Information System (INIS)

Russell, S.

2011-01-01

The Nuclear Waste Management Organization is implementing Adaptive Phased Management, Canada's plan for long-term management of used nuclear fuel. The organization is proceeding with the process for selecting a site in partnership with an informed and willing host community to safely and securely container and isolate used nuclear fuel in a deep geological repository in a suitable rock formation. Adaptive Phased Management is the culmination of more than 30 years of research, development and demonstration of repository concepts in Canada. Adaptive Phased Management uses a phased and adaptive step-wise approach to the multi-barrier system which is consistent with the long-term waste management approaches being developed in many other countries with nuclear power programs such as Sweden, Finland, Switzerland, the United Kingdom and France. The Nuclear Waste Management Organization is examining and developing conceptual designs for a deep geological repository and associated facilities for the placement of used nuclear fuel in long-lived containers. This paper will examine two of these generic conceptual designs which have recently been refined and updated. These conceptual designs will be used to support a pre-project review of repository design and safety by the Canadian Nuclear Safety Commission. (author)

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

International Nuclear Information System (INIS)

Jacob, G.R.

1988-01-01

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

Pre-construction geologic section along the cross drift through the potential high-level radioactive waste repository, Yucca Mountain, Nye County, Nevada

International Nuclear Information System (INIS)

Potter, C.J.; Day, W.C.; Sweetkind, D.S.; Juan, C.S.; Drake, R.M. II

1998-01-01

As part of the Site Characterization effort for the US Department of Energy's Yucca Mountain Project, tunnels excavated by tunnel boring machines provide access to the volume of rock that is under consideration for possible underground storage of high-level nuclear waste beneath Yucca Mountain, Nevada. The Exploratory Studies Facility, a 7.8-km-long, 7.6-m-diameter tunnel, has been excavated, and a 2.8-km-long, 5-m-diameter Cross Drift will be excavated in 1998 as part of the geologic, hydrologic and geotechnical evaluation of the potential repository. The southwest-trending Cross Drift branches off of the north ramp of the horseshoe-shaped Exploratory Studies Facility. This report summarizes an interpretive geologic section that was prepared for the Yucca Mountain Project as a tool for use in the design and construction of the Cross Drift

Potential host media for a high-level waste repository

Energy Technology Data Exchange (ETDEWEB)

Hustrulid, W

1982-01-01

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

Some concepts of model uncertainty for performance assessments of nuclear waste repositories

International Nuclear Information System (INIS)

Eisenberg, N.A.; Sagar, B.; Wittmeyer, G.W.

1994-01-01

Models of the performance of nuclear waste repositories will be central to making regulatory decisions regarding the safety of such facilities. The conceptual model of repository performance is represented by mathematical relationships, which are usually implemented as one or more computer codes. A geologic system may allow many conceptual models, which are consistent with the observations. These conceptual models may or may not have the same mathematical representation. Experiences in modeling the performance of a waste repository representation. Experiences in modeling the performance of a waste repository (which is, in part, a geologic system), show that this non-uniqueness of conceptual models is a significant source of model uncertainty. At the same time, each conceptual model has its own set of parameters and usually, it is not be possible to completely separate model uncertainty from parameter uncertainty for the repository system. Issues related to the origin of model uncertainty, its relation to parameter uncertainty, and its incorporation in safety assessments are discussed from a broad regulatory perspective. An extended example in which these issues are explored numerically is also provided

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

International Nuclear Information System (INIS)

Halsey, W.G.

1989-11-01

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

Reduction on high level radioactive waste volume and geological repository footprint with high burn-up and high thermal efficiency of HTGR

Energy Technology Data Exchange (ETDEWEB)

Fukaya, Yuji, E-mail: fukaya.yuji@jaea.go.jp; Nishihara, Tetsuo

2016-10-15

Highlights: • We evaluate the number of canisters and its footprint for HTGR. • We proposed new waste loading method for direct disposal of HTGR. • HTGR can significantly reduce HLW volume compared with LWR. - Abstract: Reduction on volume of High Level radioactive Waste (HLW) and footprint in a geological repository due to high burn-up and high thermal efficiency of High Temperature Gas-cooled Reactor (HTGR) has been investigated. A helium-cooled and graphite-moderated commercial HTGR was designed as a Gas Turbine High Temperature Reactor (GTHTR300), and that has particular features such as significantly high burn-up of approximately 120 GWd/t, high thermal efficiency around 50%, and pin-in-block type fuel. The pin-in-block type fuel was employed to reduce processed graphite volume in reprocessing. By applying the feature, effective waste loading method for direct disposal is proposed in this study. By taking into account these feature, the number of HLW canister generations and its repository footprint are evaluated by burn-up fuel composition, thermal calculation and criticality calculation in repository. As a result, it is found that the number of canisters and its repository footprint per electricity generation can be reduced by 60% compared with Light Water Reactor (LWR) representative case for direct disposal because of the higher burn-up, higher thermal efficiency, less TRU generation, and effective waste loading proposed in this study for HTGR. But, the reduced ratios change to 20% and 50% if the long term durability of LWR canister is guaranteed. For disposal with reprocessing, the number of canisters and its repository footprint per electricity generation can be reduced by 30% compared with LWR because of the 30% higher thermal efficiency of HTGR.

Iowa Geologic Sampling Points