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

International Nuclear Information System (INIS)

Anon.

1999-01-01

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

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.

Generic Repository Concepts and Thermal Analysis for Advanced Fuel Cycles - 12477

Energy Technology Data Exchange (ETDEWEB)

Hardin, Ernest [Sandia National Laboratories, P.O. Box 5800 MS 0736, Albuquerque, NM 87185 (United States); Blink, James [Lawrence Livermore National Laboratory, P.O. Box 808, Livermore, CA 94551-0808 (United States); Carter, Joe [Savannah River National Laboratory, Savannah River Site, Aiken, SC 29808 (United States); Fratoni, Massimiliano; Greenberg, Harris; Sutton, Mark [Lawrence Livermore National Laboratory (United States); Howard, Robert [Oak Ridge National Laboratory, P.O. Box 2008, Oak Ridge, TN 37831 (United States)

2012-07-01

A geologic disposal concept for spent nuclear fuel (SNF) or high-level waste (HLW) consists of three components: waste inventory, geologic setting, and concept of operations. A set of reference geologic disposal concepts has been developed by the U.S. Department of Energy (DOE), Used Fuel Disposition campaign. Reference concepts are identified for crystalline rock, clay/shale, bedded salt, and deep borehole (crystalline basement) geologic settings. These were analyzed for waste inventory cases representing a range of waste types that could be produced by advanced nuclear fuel cycles. Concepts of operation consisting of emplacement mode, repository layout, and engineered barrier descriptions, were selected based on international progress. All of these disposal concepts are enclosed emplacement modes, whereby waste packages are in direct contact with encapsulating engineered or natural materials. Enclosed modes have less capacity to dissipate heat than open modes such as that proposed for a repository at Yucca Mountain. Thermal analysis has identified important relationships between waste package size and capacity, and the duration of surface decay storage needed to meet temperature limits for different disposal concepts. For the crystalline rock and clay/shale repository concepts, a waste package surface temperature limit of 100 deg. C was assumed to prevent changes in clay-based buffer material or clay-rich host rock. Surface decay storage of 50 to 100 years is needed for disposal of high-burnup LWR SNF in 4-PWR packages, or disposal of HLW glass from reprocessing LWR uranium oxide (UOX) fuel. High-level waste (HLW) from reprocessing of metal fuel used in a fast reactor could be disposed after decay storage of 50 years or less. For disposal in salt the rock thermal conductivity is significantly greater, and higher temperatures (200 deg. C) can be tolerated at the waste package surface. Decay storage of 10 years or less is needed for high-burnup LWR SNF in 4-PWR

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

International Nuclear Information System (INIS)

Sheng, G.; Toth, J.

2000-01-01

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

Technical and logistic provisions for the delivery of radioactive wastes in the final repository Konrad

International Nuclear Information System (INIS)

Poeppinghaus, Jens

2013-01-01

The beginning of radioactive waste delivery to the final repository Konrad is planned for 2019. The main issue for the technical and logistic provisions is the development of a concept for the transport of the licensed radioactive waste containers to the site, including a turning concept for cylindrical waste forms and planning, construction and manufacture of transport equipment. Further issues include a logistic concept considering specific boundary conditions as administrative processes, priorities, special features of the delivering institutions and technical requirements of the repository.

Project Guarantee 1985. Radioactive wastes: Properties and allocation to final repository types

International Nuclear Information System (INIS)

Anon.

1985-01-01

An overview of waste-specific data, as input into constructional engineering studies and safety analyses of Project Guarantee, is presented which describes the activity inventory of the radioactive waste to be disposed of, classified according to origin, the quantitative spezifications of the waste, the concept of classifying waste into appropriate categories, grouping into major categories and distribution of these between the different repository types, and finally, control measures which ensure observance of the specifications of the waste to be disposed of. It is expedient, for conceptional considerations and for the operational phase of the repository, to split the waste up into several suitably specified waste categories according to the practical aspects of origin and conditioning. This can be done in such a way that the waste within a specific category is sufficiently homogeneous with regard to its radiological properties and chemical composition for the requirements of safety analysis. The present volume contains base-data for around 30 waste types. Two waste types are documented with more detailed data as an example of the practicability of the comprehensive waste characterisation contained in reference report NTB 84-47. It is shown that waste-specific data which go into safety analysis and constructional engineering project studies are available in an appropriate degree of detail. The method of distributing the waste between repositories with differing degrees of protection and procedures for controlling adherence to admission specifications are developed and documented. It can be ensured that no waste with an impermissibly high radiotoxicity level will later be emplaced in a repository for low- and intermediate-level waste

Radioactive waste repository study

International Nuclear Information System (INIS)

1978-11-01

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

Global nuclear waste repository proposal highlights Australia`s nuclear energy vacuum

Energy Technology Data Exchange (ETDEWEB)

Anon.

1999-06-01

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

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

International Nuclear Information System (INIS)

1995-11-01

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

Underground repository for radioactive wastes

International Nuclear Information System (INIS)

Cassibba, R.O.

1989-01-01

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

Single or multi-repository concept? A personal contribution to the discussion of pros and cons

International Nuclear Information System (INIS)

Closs, K.-D.; Duphorn, K.; Kuehn, K.

2002-01-01

The coalition agreement concluded between the parties in government, i.e. SPD and Alliance 90/The Greens, after the 1998 federal elections provided for an approach to back-end fuel cycle conditions for German nuclear power plants which differed from the practice intended up to that point. Among other things, only one single repository in deep geologic formations is to be available approximately from 2030 on. Exploration of the Gorleben salt dome is to be interrupted because of prevailing doubts while, at the same time, a basic discussion is to be held about potentially suitable host rock varieties and sites. The 'Working Party of Selection Procedures for Repository Sites (AkEnd)' instituted by the federal government is to elaborate scientific siting criteria under these conditions. The authors, who are members of AkEnd, come to the conclusion, based on technical findings and the historical back-end fuel cycle and siting situation in Germany, that a multi-repository concept incorporates substantial advantages. These are the aspects referred to: - Back-end fuel cycle concept: The multi-repository concept offers clearcut advantages in the far advanced Konrad repository project. This is true also against the background of the volume of waste with negligible heat generation to be managed by public authorities. - Long-term safety: Advantages exist, among other things, with respect to technical safety regarding possible compromises in a single-repository concept and the possible restriction of the number of potential sites. - Methods of detection: Spreading the waste over two or more repositories offers benefits in the technical aspects of detection. - Cost: A differentiated assessment of the cost arising in connection with the total amount of waste to be stored in repositories indicates benefits of a multi-repository concept, especially for the public authorities. (orig.) [de

Radioactive waste repository study

International Nuclear Information System (INIS)

1978-11-01

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

Thermo-mechanical analysis for multi-level HLW repository concept

International Nuclear Information System (INIS)

Kwon, Sang Ki; Choi, Jong Won

2004-01-01

This work aims to investigate the influence of design parameters for the underground high-level nuclear waste repository with multi-level concept. B. Necessity o In order to construct an HLW repository in deep underground, it is required to select a site, which is far from major discontinuities. To dispose the whole spent fuels generated from the Korean nuclear power plants in a repository, the underground area of about 4km 2 is required. This would be a constraints for selecting an adequate repository site. It is recommended to dispose the two different spent fuels, PWR and CANDU, in different areas at the operation efficiency point of view. It is necessary to investigate the influence of parameters, which can affect the stability of multi-level repository. It is also needed to consider the influence of heat generated from the HLW and the high in situ stress in deep location. Therefore, thermo-mechanical coupling analysis should be carried out and the results should be compared with the results from single-level repository concept. Three-dimensional analysis is required to model the disposal tunnel and deposition hole. It is recommended to use the Korean geological condition and actually measured rock properties in Korea in order to achieve reliable modeling results. A FISH routine developed for effective modeling of Thermal-Mechanical coupling was implemented in the modeling using FLAC3D, which is a commercial three-dimensional FDM code. The thermal and mechanical properties of rock and rock mass achieved from Yusung drilling site, were used for the computer modeling. Different parameters such as level distance, waste type disposed on different levels, and time interval between the operation on different levels, were considered in the three-dimensional analysis. From the analysis, it was possible to derive adequate multi-level repository concept. Results and recommendations for application From the thermal-mechanical analysis for the multi-level repository

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

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

International Nuclear Information System (INIS)

1998-06-01

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

Status of the safety concept and safety demonstration for an HLW repository in salt. Summary report

Energy Technology Data Exchange (ETDEWEB)

Bollingerfehr, W.; Buhmann, D.; Filbert, W.; and others

2013-12-15

Salt formations have been the preferred option as host rocks for the disposal of high level radioactive waste in Germany for more than 40 years. During this period comprehensive geological investigations have been carried out together with a broad spectrum of concept and safety related R and D work. The behaviour of an HLW repository in salt formations, particularly in salt domes, has been analysed in terms of assessment of the total system performance. This was first carried out for concepts of generic waste repositories in salt and, since 1998, for a repository concept with specific boundary conditions, taking the geology of the Gorleben salt dome as an example. Suitable repository concepts and designs were developed, the technical feasibility has been proven and operational and long-term safety evaluated. Numerical modelling is an important input into the development of a comprehensive safety case for a waste repository. Significant progress in the development of numerical tools and their application for long-term safety assessment has been made in the last two decades. An integrated approach has been used in which the repository concept and relevant scientific and engineering data are combined with the results from iterative safety assessments to increase the clarity and the traceability of the evaluation. A safety concept that takes full credit of the favourable properties of salt formations was developed in the course of the R and D project ISIBEL, which started in 2005. This concept is based on the safe containment of radioactive waste in a specific part of the host rock formation, termed the containment providing rock zone, which comprises the geological barrier, the geotechnical barriers and the compacted backfill. The future evolution of the repository system will be analysed using a catalogue of Features, Events and Processes (FEP), scenario development and numerical analysis, all of which are adapted to suit the safety concept. Key elements of the

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

Climate Considerations in Long-Term Safety Assessments for Nuclear Waste Repositories

Energy Technology Data Exchange (ETDEWEB)

Naeslund, Jens-Ove; Brandefelt, Jenny; Claesson Liljedahl, Lillemor [Svensk Kaernbraenslehantering AB, Stockholm (Sweden)], E-mail: jens-ove.naslund@skb.se

2013-05-15

For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

Enlargement of the Baldone near-surface radioactive waste repository

International Nuclear Information System (INIS)

Dreimanis, A.

2007-01-01

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

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

Waste inventory, waste characteristics and waste repositories in Japan

International Nuclear Information System (INIS)

Shimooka, K.

1997-01-01

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

Climate considerations in long-term safety assessments for nuclear waste repositories.

Science.gov (United States)

Näslund, Jens-Ove; Brandefelt, Jenny; Liljedahl, Lillemor Claesson

2013-05-01

For a deep geological repository for spent nuclear fuel planned in Sweden, the safety assessment covers up to 1 million years. Climate scenarios range from high-end global warming for the coming 100 000 years, through deep permafrost, to large ice sheets during glacial conditions. In contrast, in an existing repository for short-lived waste the activity decays to low levels within a few tens of thousands of years. The shorter assessment period, 100 000 years, requires more focus on climate development over the coming tens of thousands of years, including the earliest possibility for permafrost growth and freezing of the engineered system. The handling of climate and climate change in safety assessments must be tailor-made for each repository concept and waste type. However, due to the uncertain future climate development on these vast time scales, all safety assessments for nuclear waste repositories require a range of possible climate scenarios.

Establishing the concept of buffer for a high-level radioactive waste repository: An approach

Energy Technology Data Exchange (ETDEWEB)

Lee, Jae Owan; Lee, Min Soo; Choi, Heui Joo [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-12-15

The buffer is a key component of the engineered barrier system in a high-level radioactive waste (HLW) repository. The present study reviewed the requirements and functional criteria of the buffer reported in literature, and also based on the results, proposed an approach to establish a buffer concept which is applicable to an HLW repository in Korea. The hydraulic conductivity, radionuclide-retarding capacity (equilibrium distribution coefficient and diffusion coefficient), swelling pressure, thermal conductivity, mechanical properties, organic carbon content, and initialization rate were considered as major technical parameters for the functional criteria of the buffer. Domestic bentonite (Ca-bentonite) and, as an alternative, MX-80 (Na-bentonite) were proposed for the buffer of an HLW repository in Korea. The technical specifications for those proposed bentonites were set to parameter values that conservatively satisfy Korea's functional criteria for the Ca-bentonite and Swedish criteria for the Na-bentonite. The thickness of the buffer was determined by evaluating the means of shear behavior, radionuclide release, and heat conduction, which resulted in the proper buffer thickness of 0.25 to 0.5 m. However, the final thickness of the buffer should be determined by considering coupled thermal-hydraulic-mechanical evaluation and economics and engineering aspects as well.

Coupled thermo–hydro–mechanical processes for the Dutch radioactive waste repository

NARCIS (Netherlands)

Buragohain, P.; Vardon, P.J.; Hicks, M.A.; Vardon, P.J.; Bykov, D.

2016-01-01

Disposal of spent nuclear fuel and long lived radioactive waste in deep clay geological formations is one of the promising options worldwide. In this concept of the geological disposal system, the Boom Clay is considered as a potential host rock when designing a generic waste repository in the

Radioactive Waste Repositories and Incentives to Local Communities

International Nuclear Information System (INIS)

Knapp, A.; Medakovic, S.

2008-01-01

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

Geologic environments for nuclear waste repositories

Directory of Open Access Journals (Sweden)

Paleologos Evan K.

2017-01-01

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

Alternative configurations for the waste-handling building at the Yucca Mountain Repository

International Nuclear Information System (INIS)

1990-08-01

Two alternative configurations of the waste-handling building have been developed for the proposed nuclear waste repository in tuff at Yucca Mountain, Nevada. One configuration is based on criteria and assumptions used in Case 2 (no monitored retrievable storage facility, no consolidation), and the other configuration is based on criteria and assumptions used in Case 5 (consolidation at the monitored retrievable storage facility) of the Monitored Retrievable Storage System Study for the Repository. Desirable waste-handling design concepts have been selected and are included in these configurations. For each configuration, general arrangement drawings, plot plans, block flow diagrams, and timeline diagrams are prepared

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

Project ANSICHT. Final repository concept and backfilling and sealing concept for the final repository site model SUeD; Projekt ANSICHT. Endlagerkonzept sowie Verfuell- und Verschlusskonzept fuer das Endlagerstandortmodell SUeD. Technischer Bericht

Energy Technology Data Exchange (ETDEWEB)

Jobmann, Michael; Lommerzheim, Andree

2015-08-03

In the frame of ANSICHT the methodology for the demonstration of safe enclosure for high-level heat generating radioactive wastes is described. The report is based on the safety requirements for final repository concepts and shows a first backfilling and sealing concept that was developed for the final repository site model SUeD. The final repository model SUeD is based on a horizontal line storage concept, the Gorleben (VSG) and ERATO container concept and the mine layout were adopted and adapted to the given conditions. The backfill and sealing concept includes migration barriers, line closures and shaft closures in the frame of a redundant and diverse enclosure system. For all technical and geotechnical barrier components the long-term functional requirements were defined. The backfilling concept of underground cavities considers the variety of possible cavities in the line and infrastructure areas.

Reconstruction and modernization of Novi Han radioactive waste repository

International Nuclear Information System (INIS)

Kolev, I.

2001-01-01

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

Performance analysis of a repository for low and intermediate level reactor waste

International Nuclear Information System (INIS)

Vieno, T.; Nordman, H.; Vuori, S.; Peltonen, E.

1987-01-01

In Finland, utilities producing nuclear energy are responsible for the management of the radioactive waste, including final disposal. As regards low and intermediate level waste, the approach has been adopted to employ the power plant sites for locations of repositories. The repositories will be excavated at the depth of about 50 to 125 m in the bedrock of the two Finnish nuclear power plant sites, Loviisa and Olkiluoto. The performance analysis presented in this paper has been carried out for the Preliminary Safety Analysis Report (PSAR) of the Olkiluoto repository. A flexible model has been developed to estimate the release of radionuclides from waste packages and their subsequent transport through the engineered barriers in the repository. Gradual degradation of the engineered barriers is accounted for by altering parameters at fixed time points. Safety margins of the disposal concept have been evaluated by including disturbed evolution scenarios in the analysis. 13 references, 10 figures, 2 tables

Waste package/repository impact study: Final report

Energy Technology Data Exchange (ETDEWEB)

1985-09-01

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

Waste package/repository impact study: Final report

International Nuclear Information System (INIS)

1985-09-01

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

Developing multinational radioactive waste repositories: Infrastructural framework and scenarios of cooperation

International Nuclear Information System (INIS)

2004-10-01

Currently the management of radioactive wastes centres on national strategies for collection, treatment, interim storage and disposal. This tendency to focus exclusively on national strategies reflects the fact that radioactive waste is a sensitive political issue, making cooperation among countries difficult. It is consistent with the accepted principle that a country that enjoys the benefit of nuclear energy, or the utilization of nuclear technology, should also take full responsibility for managing the generated radioactive waste. However, there are countries whose radioactive waste volumes do not easily justify a national repository, and/or countries that do not have the resources or favourable natural conditions for waste disposal to dedicate to a national repository project or would prefer to collaborate in shared initiatives because of their economic advantages. In such cases it may be appropriate for these countries to engage in a multinational collaborative effort to ensure that they have access to a common repository, in order that they can fulfil their responsibilities for their managing wastes safely. In response to requests from several Member States expressing an interest in multinational disposal options, the IAEA produced in 1998 a TECDOC outlining the important factors to be taken into account in the process of realizing such options. These factors include for example, technical (safety), institutional (legal, safeguards), economic (financial) socio-political (public acceptance) and ethical considerations. The present report reviews the work done in the previous study, taking into account developments since its publication as well as current activities in the field of multinational repositories. The report attempts to define the concepts involved in the creation of multinational repositories, to explore the likely scenarios, to examine the conditions for successful implementation, and to point out the benefits and challenges inherent to

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

International Nuclear Information System (INIS)

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

1998-01-01

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

Investigations of possibilities to dispose of spent nuclear fuel in Lithuania: a model case. Volume 2, Concept of Repository in Crystalline Rocks

International Nuclear Information System (INIS)

Motiejunas, S.; Poskas, P.

2005-01-01

The aim is to present the generic repository concept in crystalline rocks in Lithuania and cost assessment of the disposal of spent nuclear fuel and long-lived intermediate level waste in this repository. Due to limited budget of this project the repository concept development for Lithuania was based mostly on the experience of foreign countries. In this Volume a review of the existing information on disposal concept in crystalline rocks from various countries is presented. Described repository concept for crystalline rocks in Lithuania covers repository layout, backfill, canister, construction materials and auxiliary buildings. Costs calculations for disposal of spent nuclear fuel and long-lived intermediate-level wastes from Ignalina NPP are presented too. Thermal, criticality and other important disposal evaluations for RBMK-1500 spent nuclear fuel emplaced in copper canister were performed and described

Evaluation of site-generated radioactive waste treatment and disposal methods for the Yucca Mountain repository

International Nuclear Information System (INIS)

Subramanian, C.V.; Jardine, L.J.

1989-01-01

This study identifies the sources of radioactive wastes that may be generated at the proposed high-level waste (HLW) repository at Yucca Mountain, NV, estimates the waste quantities and characteristics, compares technologies available for waste treatment and disposal, and develops recommended concepts for site-generated waste treatment and disposal. The scope of this study is limited to operations during the emplacement phase, in which 70,000 MTU of high-level waste will be received and emplaced at the proposed repository. The evaluations consider all radioactive wastes generated during normal operations in surface and underground facilities. Wastes generated as a result of accidents are not addressed; accidents that could result in large quantities of radioactive waste are expected to occur very infrequently and temporary, portable systems could be used for any necessary cleanup. The results of this study can be used to develop more definitive plans for managing the site-generated wastes and as a basis for the design of associated facilities at the proposed repository

Classifying decommissioning wastes for allocation to appropriate final repositories

International Nuclear Information System (INIS)

Alder, J.C.; Tunaboylu, K.

1982-01-01

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

International perspective on repositories for low level waste

International Nuclear Information System (INIS)

Bergstroem, Ulla; Pers, Karin; Almen, Ylva

2011-12-01

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

International perspective on repositories for low level waste

Energy Technology Data Exchange (ETDEWEB)

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

2011-12-15

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

The preliminary design and feasibility study of the spent fuel and high level waste repository in the Czech Republic

International Nuclear Information System (INIS)

Valvoda, Z.; Holub, J.; Kucerka, M.

1996-01-01

In the year 1993, began the Program of Development of the Spent Fuel and High Level Waste Repository in the Conditions of the Czech Republic. During the first phase, the basic concept and structure of the Program has been developed, and the basic design criteria and requirements were prepared. In the conditions of the Czech Republic, only an underground repository in deep geological formation is acceptable. Expected depth is between 500 to 1000 meters and as host rock will be granites. A preliminary variant design study was realized in 1994, that analyzed the radioactive waste and spent fuel flow from NPPs to the repository, various possibilities of transportation in accordance to the various concepts of spent fuel conditioning and transportation to the underground structures. Conditioning and encapsulation of spent fuel and/or radioactive waste is proposed on the repository site. Underground disposal structures are proposed at one underground floor. The repository will have reserve capacity for radioactive waste from NPPs decommissioning and for waste non acceptable to other repositories. Vertical disposal of unshielded canisters in boreholes and/or horizontal disposal of shielded canisters is studied. As the base term of the start up of the repository operation, the year 2035 has been established. From this date, a preliminary time schedule of the Project has been developed. A method of calculating leveled and discounted costs within the repository lifetime, for each of selected 5 variants, was used for economic calculations. Preliminary expected parametric costs of the repository are about 0,1 Kc ($0.004) per MWh, produced in the Czech NPPs. In 1995, the design and feasibility study has gone in more details to the technical concept of repository construction and proposed technologies, as well as to the operational phase of the repository. Paper will describe results of the 1995 design work and will present the program of the repository development in next period

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

Low level waste repositories

International Nuclear Information System (INIS)

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

1983-11-01

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

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

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

Transport concept of new waste management system (inner packaging system)

International Nuclear Information System (INIS)

Hakozaki, K.; Wada, R.

2004-01-01

Kobe Steel, Ltd. (KSL) and Transnuclear Tokyo (TNT) have jointly developed a new waste management system concept (called ''Inner packaging system'') for high dose rate wastes generated from nuclear power plants under cooperation with Tokyo Electric Power Company (TEPCO). The inner packaging system is designed as a total management system dedicated to the wastes from nuclear plants in Japan, covering from the wastes conditioning in power plants up to the disposal in final repository. This paper presents the new waste management system concept

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

Release consequence analysis for a hypothetical geologic radioactive waste repository in hard rock

International Nuclear Information System (INIS)

1979-12-01

This report makes an evaluation of the long-term behaviour of the wastes placed in a hard rock repository. Impacts were analyzed for the seven reference fuel cycles of WG 7. The reference repository for this study is for granitic rock or gneiss as the host rock. The descriptions of waste packages and repository facilities used in this study represent only one of many possible designs based on the multiple barriers concept. The repository's size is based on a nuclear economy producing 100 gigawatts of electricity per year for 1 year. The objective of the modeling efforts presented in this study is to predict the rate of transport of radioactive contaminants from the repository through the geosphere to the biosphere and thus determine an estimate of the potential dose to humans so that the release consequence impacts of the various fuel cycles can be compared. Currently available hydrologic, leach, transport, and dose models were used in this study

Concepts and Technologies for Radioactive Waste Disposal in Rock Salt

Directory of Open Access Journals (Sweden)

Wernt Brewitz

2007-01-01

Full Text Available In Germany, rock salt was selected to host a repository for radioactive waste because of its excellent mechanical properties. During 12 years of practical disposal operation in the Asse mine and 25 years of disposal in the disused former salt mine Morsleben, it was demonstrated that low-level wastes (LLW and intermediate-level wastes (ILW can be safely handled and economically disposed of in salt repositories without a great technical effort. LLW drums were stacked in old mining chambers by loading vehicles or emplaced by means of the dumping technique. Generally, the remaining voids were backfilled by crushed salt or brown coal filter ash. ILW were lowered into inaccessible chambers through a borehole from a loading station above using a remote control.Additionally, an in-situ solidification of liquid LLW was applied in the Morsleben mine. Concepts and techniques for the disposal of heat generating high-level waste (HLW are advanced as well. The feasibility of both borehole and drift disposal concepts have been proved by about 30 years of testing in the Asse mine. Since 1980s, several full-scale in-situ tests were conducted for simulating the borehole emplacement of vitrified HLW canisters and the drift emplacement of spent fuel in Pollux casks. Since 1979, the Gorleben salt dome has been investigated to prove its suitability to host the national final repository for all types of radioactive waste. The “Concept Repository Gorleben” disposal concepts and techniques for LLW and ILW are widely based on the successful test operations performed at Asse. Full-scale experiments including the development and testing of adequate transport and emplacement systems for HLW, however, are still pending. General discussions on the retrievability and the reversibility are going on.

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.

Development of a central final repository management for the coordination of the waste for Schacht Konrad from public authorities

International Nuclear Information System (INIS)

Graffunder, Iris; Dominke-Bendix, Carola; Waldek, Achim

2012-01-01

The central final repository management is supposed to fulfill the following tasks: active collaboration of Konrad contract draft, signing of internal contracts and agreements, cooperation contract with GNS, cooperation with coordination authorities, inventory taking of wastes (existing inventory and prognosis) and interim storage capacities of public authorities, development of planning and management software, optimization of the final repository documentation, container management, logistics concept, long-term disposal planning and prognosis, planning and coordination of the annual waste amount, management and documentation of disposed waste allocation, coordination of transport schedules, consulting service for waste obligations (final repository requirements, product control, documentation).

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

International Nuclear Information System (INIS)

Vladescu, Gabriela; Necula, Daniela

2000-01-01

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

Planning the rad waste repository - Croatian case

International Nuclear Information System (INIS)

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

1996-01-01

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

Analysis of the risk assessment of a waste repository for radioactive waste from the decommissioning of nuclear power plants

International Nuclear Information System (INIS)

Weil, L.

1984-09-01

A review of decommissioning experiences and concepts is presented. The radioactive inventory of LWR of modern design at final shutdown is estimated on the basis of activation analysis and empirical data on contamination. In combination with existing types of waste packages and deposition techniques these results allow a prediction of the necessary repository volume for the decommissioning wastes in the Federal Republic of Germany. The essential element of this investigation is the development of a model for the quantitative analysis of the accident 'water intrusion' in the repository. Based on the fundamental chemical and physical processes governing nuclide migration a transport equation is obtained which can be restricted to one dimension due to the thickness and the low permeability of the geological layers above the repository. The radiological consequences are evaluated. The long-lived activation product Ni-59 turns out to be critical radionuclide. Despite a number of conservatisms in the model the evaluated doses are acceptable. The results clearly support the long term safety of the 'Konrad' mine as a low-level waste repository. (orig./HP) [de

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

Licensing information needs for a high-level waste repository

International Nuclear Information System (INIS)

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

1985-01-01

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

Chemotoxic materials in a final repository for high-level radioactive wastes. CHEMOTOX concept for defence in depth concerning ground water protection from chemotoxic materials in a final high-level waste repository

International Nuclear Information System (INIS)

Alt, Stefan; Sailer, Michael; Schmidt, Gerhard; Herbert, Horst-Juergen; Krone, Juergen; Tholen, Marion

2009-01-01

The disposal of high-level radioactive wastes in a final repository includes chemotoxic materials. The chemotoxic materials are either part of the radioactive material or part of the packaging material, or the structures within the repository. In the frame of the licensing procedure it has to be demonstrated that no hazardous pollution of the ground water or other disadvantageous changes can occur. The report describes the common project of the Oeko-Institut e.V., the DBE Technology GmbH and the GRS mbH concerning the possible demonstration of a systematic protection of the groundwater against chemotoxic materials in case of a final high-level-radioactive waste repository in the host materials salt and clay stone.

Management of radioactive waste at Novi Han Repository

International Nuclear Information System (INIS)

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

2002-01-01

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

Public concerns and choices regarding nuclear-waste repositories

International Nuclear Information System (INIS)

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

1981-06-01

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

Technical realization of a closure concept for a chamber-system in the underground Richard repository in the Czech Republic

International Nuclear Information System (INIS)

Kucerka, Miroslav

2006-01-01

The Phare project CZ 632.02.04 'Realization of closure of a chamber in the Richard repository as input for establishing a safety case' is a follow up implementation phase of the Phare project, CZ 01.14.03 'Solution for closure of a chamber in the Richard repository'. Main objective of both projects is to propose and realize a disposal system in selected chambers of the Richard repository, which will eliminate burden from the past practices in waste management during the first phase of the Richard repository operation (1965 - 1980) and which will improve its overall long term safety. This objective will be assured by realization of the concept of so called 'hydraulic cage', which technical solution was developed by DBE Technology within the Phare project CZ 01.14.03. The solution is described in the previous presentation 'Hydraulic Cage Concept for Waste Chambers and its Technical Implementation for the Underground Richard Repository, Litomerice, Czech Republic'. (author)

Concepts for Waste Retrieval and Alternate Storage of Radioactive Waste

International Nuclear Information System (INIS)

F.J. Bierich

2005-01-01

The primary purpose of this technical report is to present concepts for retrieval operations, equipment to be used, scenarios under which waste retrieval operations will take place, methods for responding to potential retrieval problems, and compliance with the preclosure performance objectives of 10 CFR 63.111(a) and (b) [DIRS 156605] during the retrieval of waste packages from the subsurface repository. If a decision for retrieval is made for any or all of the waste, the waste to be retrieved would be dispositioned in accordance with the regulations applicable at the time. The secondary purpose is to present concepts for the design, construction, and operation of an alternate storage facility. The alternate storage facility would temporarily house the retrieved waste until final disposition is established. The concept presented is consistent with current practices and regulations for the protection of public health and safety and the environment, it demonstrates the feasibility of such a facility, if required, and it is based on the consideration for keeping radiation exposure as low as is reasonably achievable (ALARA)

Progress towards developing an international repository for radioactive waste

International Nuclear Information System (INIS)

Kurzeme, M.

2001-01-01

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

Evaluation of methods and tools to develop safety concepts and to demonstrate safety for an HLW repository in salt. Final report

Energy Technology Data Exchange (ETDEWEB)

Bollingerfehr, W.; Buhmann, D.; Doerr, S.; and others

2017-03-15

Salt formations have been the preferred option as host rocks for the disposal of high level radioactive waste in Germany for more than 40 years. During this period comprehensive geological investigations have been carried out together with a broad spectrum of concept and safety related R and D work. The behaviour of an HLW repository in salt formations, particularly in salt domes, has been analysed in terms of assessment of the total system performance. This was first carried out for concepts of generic waste repositories in salt and, since 1998, for a repository concept with specific boundary conditions, taking the geology of the Gorleben salt dome as an example. Suitable repository concepts and designs were developed, the technical feasibility has been proven and operational and long-term safety evaluated. Numerical modelling is an important input into the development of a comprehensive safety case for a waste repository. Significant progress in the development of numerical tools and their application for long-term safe ty assessment has been made in the last two decades. An integrated approach has been used in which the repository concept and relevant scientific and engineering data are combined with the results from iterative safety assessments to increase the clarity and the traceability of the evaluation. A safety concept that takes full credit of the favourable properties of salt formations was developed in the course of the R and D project ISIBEL, which started in 2005. This concept is based on the safe containment of radioactive waste in a specific part of the host rock formation, termed the containment providing rock zone, which comprises the geological barrier, the geotechnical barriers and the compacted backfill. The future evolution of the repository system will be analysed using a catalogue of Features, Events and Processes (FEP), scenario development and numerical analysis, all of which are adapted to suit the safety concept. Key elements of the

Evaluation of methods and tools to develop safety concepts and to demonstrate safety for an HLW repository in salt. Final report

International Nuclear Information System (INIS)

Bollingerfehr, W.; Buhmann, D.; Doerr, S.

2017-03-01

Salt formations have been the preferred option as host rocks for the disposal of high level radioactive waste in Germany for more than 40 years. During this period comprehensive geological investigations have been carried out together with a broad spectrum of concept and safety related R and D work. The behaviour of an HLW repository in salt formations, particularly in salt domes, has been analysed in terms of assessment of the total system performance. This was first carried out for concepts of generic waste repositories in salt and, since 1998, for a repository concept with specific boundary conditions, taking the geology of the Gorleben salt dome as an example. Suitable repository concepts and designs were developed, the technical feasibility has been proven and operational and long-term safety evaluated. Numerical modelling is an important input into the development of a comprehensive safety case for a waste repository. Significant progress in the development of numerical tools and their application for long-term safe ty assessment has been made in the last two decades. An integrated approach has been used in which the repository concept and relevant scientific and engineering data are combined with the results from iterative safety assessments to increase the clarity and the traceability of the evaluation. A safety concept that takes full credit of the favourable properties of salt formations was developed in the course of the R and D project ISIBEL, which started in 2005. This concept is based on the safe containment of radioactive waste in a specific part of the host rock formation, termed the containment providing rock zone, which comprises the geological barrier, the geotechnical barriers and the compacted backfill. The future evolution of the repository system will be analysed using a catalogue of Features, Events and Processes (FEP), scenario development and numerical analysis, all of which are adapted to suit the safety concept. Key elements of the

The Konrad mine - the planned German repository for radioactive waste with negligible heat generation

International Nuclear Information System (INIS)

Berg, H.P.; Brennecke, P.

1990-07-01

This report deals with the planned Konrad repository and describes the current state of affairs. In particular, the technical concept is explained and a survey of the radioactive waste intended for disposal is given. The safety assessments which have been made, including the derivation of preliminary waste acceptance requirements, are described and the principles of the waste package control are outlined. (orig./HP) [de

Natural analogues, paradigm for manmade repositories for radioactive wastes

International Nuclear Information System (INIS)

Pavelescu, M.; Pavelescu, A.

2004-01-01

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

Radioactive Waste Repositories Administration - SURAO

International Nuclear Information System (INIS)

Kucerka, M.

1998-01-01

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

Modeling transient heat transfer in nuclear waste repositories.

Science.gov (United States)

Yang, Shaw-Yang; Yeh, Hund-Der

2009-09-30

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

Viability Assessment of a Repository at Yucca Mountain. Volume 2: Preliminary Design Concept for the Repository and Waste Package

Energy Technology Data Exchange (ETDEWEB)

None

1998-12-01

This volume describes the major design features of the Monitored Geologic Repository. This document is not intended to provide an exhaustive, detailed description of the repository design. Rather, this document summarizes the major systems and primary elements of the design that are radiologically significant, and references the specific technical documents and design analyses wherein the details can be found. Not all portions of the design are at the same level of completeness. Highest priority has been given to assigning resources to advance the design of the Monitored Geologic Repository features that are important to radiological safety and/or waste isolation and for which there is no NRC licensing precedent. Those features that are important to radiological safety and/or waste isolation, but for which there is an NRC precedent, receive second priority. Systems and features that have no impact on radiological safety or waste isolation receive the lowest priority. This prioritization process, referred to as binning, is discussed in more detail in Section 2.3. Not every subject discussed in this volume is given equal treatment with regard to the level of detail provided. For example, less detail is provided for the surface facility design than for the subsurface and waste package designs. This different level of detail is intentional. Greater detail is provided for those functions, structures, systems, and components that play key roles with regard to protecting radiological health and safety and that are not common to existing nuclear facilities already licensed by NRC. A number of radiological subjects are not addressed in the VA, (e.g., environmental qualification of equipment). Environmental qualification of equipment and other radiological safety considerations will be addressed in the LA. Non-radiological safety considerations such as silica dust control and other occupational safety considerations are considered equally important but are not addressed in

Hydrothermal conditions around a radioactive waste repository

International Nuclear Information System (INIS)

Thunvik, R.; Braester, C.

1981-12-01

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

Hydrogen modelling for vitrified wastes repository

International Nuclear Information System (INIS)

Voinis, S.; Breton, J.

1992-01-01

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

Radioactive waste repository of high ecological safety

International Nuclear Information System (INIS)

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

2000-01-01

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

Retrievability as proposed in the US repository concept

International Nuclear Information System (INIS)

Harrington, P.G.

2000-01-01

The Nuclear Waste Policy Act states that any repository shall be designed and constructed to permit retrieval. Reasons for retrieval include public health and safety, environmental concerns, and recovery of economically valuable contents of spent nuclear fuel. The Nuclear Regulatory Commission requires that waste must be retrievable at any time up to 50 years after start of emplacement. The US Department of Energy intends to maintain a retrieval capability throughout the preclosure period. Possible preclosure periods range from a minimum of 50 years to as much as 300 years. Repository closure includes sealing all accessible portions of the repository, including ventilation shafts, access ramps and boreholes. Drip shields will be installed over the waste packages. Access to the repository after closure is not intended. The proposed repository includes horizontal emplacement drifts located in the unsaturated zone. The emplacement drift centerline spacing is 81 meters to provide a subboiling region between drifts for water drainage. A drip shield covers the waste packages. All emplacement drifts remain open until closure of the repository, providing performance benefits such as removing heat and moisture during the preclosure period and lowering postclosure temperatures. This does not impede retrieval, permitting a reversal of the emplacement process to accomplish retrieval under normal conditions. The preclosure period is therefore not to enhance retrievability, but does improve performance, and the resultant extension of the retrievability capability is a secondary effect. Information must be provided from the performance confirmation program to support a regulatory decision to close. Closure would isolate the repository from the accessible environment, preclude preferential flowpaths for water into the mountain, and minimize the possibility of inadvertent intrusion. (author)

Characteristics of potential repository wastes

International Nuclear Information System (INIS)

Notz, K.J.

1989-01-01

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

Technical feasibility of retrieval within the UK repository concept for ILW/LLW

International Nuclear Information System (INIS)

McCall, A.; McKirdy, B.

2000-01-01

Nirex is developing a staged, reversible concept for the disposal of ILW and certain LLW in the UK. Within that concept, the retrievability strategy includes the option of keeping open the repository, for an extended period, after all waste has been emplaced. In examining the feasibility of such an approach, a number of key technical issues have been identified and options for addressing these issues have been established. This paper will describe the issues identified and the development of practical solutions for incorporating retrievability within the Nirex concept. (author)

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

Energy Technology Data Exchange (ETDEWEB)

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

2016-06-08

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

Concept of Operations for Waste Transport, Emplacement, and Retrieval

International Nuclear Information System (INIS)

Raczka, Norman T.

2001-01-01

The preparation of this technical report has two objectives. The first objective is to discuss the base case concepts of waste transport, emplacement, and retrieval operations and evaluate these operations relative to a lower-temperature repository design. Aspects of the operations involved in waste transport, emplacement and retrieval may be affected by the lower-temperature operating schemes. This report evaluates the effects the lower-temperature alternatives may have on the operational concepts involved in emplacing and retrieving waste. The second objective is to provide backup material for the design description, in a traceable and defensible format, for Section 2 of the Waste Emplacement/Retrieval System Description Document

Investigation on design of repository for radioactive waste

International Nuclear Information System (INIS)

Zhang Boming; Zhang Ruixue; Wang Fengying

2010-01-01

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

Rock support for nuclear waste repositories

International Nuclear Information System (INIS)

Abramson, L.W.; Schmidt, B.

1984-01-01

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

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

International Nuclear Information System (INIS)

Rosa, E.A.

1993-01-01

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

Coupled thermo-mechanical analysis of granite for high-level radioactive waste repository

International Nuclear Information System (INIS)

Liu Wengang; Wang Ju; Zhou Hongwei; Jiang Pengfei; Yang Chunhe

2008-01-01

High-level radioactive wastes (HLW) repository is a special deep underground engineering, and in the stages of site selection, designing, constructing ,the stability evaluation, lots of important rock mechanics problems need to be resolved. During the decay of nuclear waste, enormous thermal energy was released and temperature variation caused dynamic distribution of stress and deformation field of surrounding rock of repository. BeiShan region of Gansu province was selected to be the repository field in the future, it is of practical significance to do research on granite in this region. Based on the concept model of HLW repository, this thesis calculates temperature field, stress field and deformation field of HLW repository surrounding rock under the condition of TM coupled with applying the finite difference FLAC 3D . From this study, thermo-mechanical characteristic of granite is obtained primarily under given canister heat source and given decay law function. And these results show that the reasonable space between disposal hole is 8 m-12 m, and the peak temperature of the canister surface is 130 ℃, the centerline temperature between pits is about 40 ℃ which is maintained for about hundreds of years under given heating output at -500 m depth. (authors)

Modelling gas generation in radioactive waste repositories

International Nuclear Information System (INIS)

Agg, P.J.

1993-02-01

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

Modelling gas generation in radioactive waste repositories

International Nuclear Information System (INIS)

Agg, P.J.

1992-07-01

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

Radioactive waste disposal: Recommendations for a repository site selection

International Nuclear Information System (INIS)

Cadelli, N.; Orlowski, S.

1992-01-01

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

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

Source term evaluation model for high-level radioactive waste repository with decay chain build-up.

Science.gov (United States)

Chopra, Manish; Sunny, Faby; Oza, R B

2016-09-18

A source term model based on two-component leach flux concept is developed for a high-level radioactive waste repository. The long-lived radionuclides associated with high-level waste may give rise to the build-up of activity because of radioactive decay chains. The ingrowths of progeny are incorporated in the model using Bateman decay chain build-up equations. The model is applied to different radionuclides present in the high-level radioactive waste, which form a part of decay chains (4n to 4n + 3 series), and the activity of the parent and daughter radionuclides leaching out of the waste matrix is estimated. Two cases are considered: one when only parent is present initially in the waste and another where daughters are also initially present in the waste matrix. The incorporation of in situ production of daughter radionuclides in the source is important to carry out realistic estimates. It is shown that the inclusion of decay chain build-up is essential to avoid underestimation of the radiological impact assessment of the repository. The model can be a useful tool for evaluating the source term of the radionuclide transport models used for the radiological impact assessment of high-level radioactive waste repositories.

Robotics and remote handling concepts for disposal of high-level nuclear waste

International Nuclear Information System (INIS)

McAffee, Douglas; Raczka, Norman; Schwartztrauber, Keith

1997-01-01

This paper summarizes preliminary remote handling and robotic concepts being developed as part of the US Department of Energy's (DOE) Yucca Mountain Project. The DOE is currently evaluating the Yucca Mountain Nevada site for suitability as a possible underground geologic repository for the disposal of high level nuclear waste. The current advanced conceptual design calls for the disposal of more than 12,000 high level nuclear waste packages within a 225 km underground network of tunnels and emplacement drifts. Many of the waste packages may weigh as much as 66 tonnes and measure 1.8 m in diameter and 5.6 m long. The waste packages will emit significant levels of radiation and heat. Therefore, remote handling is a cornerstone of the repository design and operating concepts. This paper discusses potential applications areas for robotics and remote handling technologies within the subsurface repository. It also summarizes the findings of a preliminary technology survey which reviewed available robotic and remote handling technologies developed within the nuclear, mining, rail and industrial robotics and automation industries, and at national laboratories, universities, and related research institutions and government agencies

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Design criteria development for the structural stability of nuclear waste repository

Energy Technology Data Exchange (ETDEWEB)

Yun, C H [Korea Institute of Nuclear Safety, Taejon (Korea, Republic of); Yu, T S [Daewoo Engineering Company, Sungnam (Korea, Republic of); Ko, H M [Seoul National Univ., Seoul (Korea, Republic of)

1990-11-15

The objective of the present project is to develop design criteria for the structural stability of rock cavity for the underground repository are defined, according to which detailed descriptions for design methodologies, design stages and stability analysis of the cavity are made. The proposed criteria can be used as a guide for the preparation of design codes which are to be established as the site condition and technical emplacement procedure are fixed. The present report first reviews basic safety requirements and criteria of the underground disposal of nuclear wastes for the establishment of design concepts and stability analysis of the rock cavity. Important factors for the design are also described by considering characteristics of the wastes and underground facilities. The present project has investigated technical aspects on the design of underground structures based on the currently established underground construction technologies, and presented a proposal for design criteria for the structural stability of the nuclear waste repository. The proposed criteria consist of general provisions, geological exploration, rock classification, design process and methods, supporting system, analyses and instrumentation.

Regulations for the disposal of radioactive waste in the Konrad repository - 59105

International Nuclear Information System (INIS)

Jung, Hagen G.; Bandt, Gabriele

2012-01-01

In Germany low / medium level waste, which is classified here as radioactive waste with negligible heat generation, will be disposed of in the Konrad underground repository. The construction and the operation of this nuclear facility required authorization by different fields of law, i.e., by nuclear law, mining law and water law. Whereas the nuclear law considers solely radiological aspects, the relevant permit issued according to the water law considers the impact of radioactive as well as non-radioactive harmful substances. The Federal Office for Radiation Protection (BfS) as operator of the repository and permit holder has (a) to record the disposed of radioactive and non-radioactive harmful substances and (b) to balance them. To meet these requirements BfS has developed a concept, which led to a site specific solution. Threshold values were defined for recording and for balancing the harmful substances. It had to be verified that by disposal of radioactive waste packages according to these values an adverse effect on the near-surface groundwater can be excluded. The Lower Saxony Water Management, Coastal Protection and Nature Conservation Agency (NLWKN) as the responsible water law regulatory authority approved the operator's concept as appropriate to comply with the requirements of the Water Law Permit. Nonetheless, collateral clauses were imposed to assure this. (authors)

National radioactive waste repository draft EIS. 2 volumes

International Nuclear Information System (INIS)

2002-01-01

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

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)

Radioactive waste repository study

International Nuclear Information System (INIS)

1978-11-01

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

Review of important rock mechanics studies required for underground high level nuclear waste repository program

Energy Technology Data Exchange (ETDEWEB)

Kwon, S.; Cho, W. J

2007-01-15

Disposal concept adapting room and pillar method, which is a confirmed technique in mining and tunnel construction for long time, has advantages at cost, safety, technical feasibility, flexibility, and international cooperation point of views. Then the important rock mechanics principals and in situ and laboratory tests for understanding the behavior of rock, buffer, and backfill as well as their interactions will be reviewed. The accurate understanding of them is important for developing a safe disposal concept and successful operation of underground repository for permanent disposal of radioactive wastes. First of all, In this study, current status of rock mechanics studies for HLW disposal in foreign countries such as Sweden, USA, Canada, Finland, Japan, and France were reviewed. After then the in situ and laboratory tests for site characterization were summarized. Furthermore, rock mechanics studies required during the whole procedure for the disposal project from repository design to the final closure will be reviewed systematically. This study will help for developing a disposal system including site selection, repository design, operation, maintenance, and closure of a repository in deep underground rock. By introducing the required rock mechanics tests at different stages, it would be helpful from the planning stage to the operation stage of a radioactive waste disposal project.

Review of important rock mechanics studies required for underground high level nuclear waste repository program

International Nuclear Information System (INIS)

Kwon, S.; Cho, W. J.

2007-01-01

Disposal concept adapting room and pillar method, which is a confirmed technique in mining and tunnel construction for long time, has advantages at cost, safety, technical feasibility, flexibility, and international cooperation point of views. Then the important rock mechanics principals and in situ and laboratory tests for understanding the behavior of rock, buffer, and backfill as well as their interactions will be reviewed. The accurate understanding of them is important for developing a safe disposal concept and successful operation of underground repository for permanent disposal of radioactive wastes. First of all, In this study, current status of rock mechanics studies for HLW disposal in foreign countries such as Sweden, USA, Canada, Finland, Japan, and France were reviewed. After then the in situ and laboratory tests for site characterization were summarized. Furthermore, rock mechanics studies required during the whole procedure for the disposal project from repository design to the final closure will be reviewed systematically. This study will help for developing a disposal system including site selection, repository design, operation, maintenance, and closure of a repository in deep underground rock. By introducing the required rock mechanics tests at different stages, it would be helpful from the planning stage to the operation stage of a radioactive waste disposal project

Developing of Radioactive Wastes Management Safety at Baldone Repository Radons

International Nuclear Information System (INIS)

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

2008-01-01

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

Acceptability of a low and intermediate level radioactive waste repository

International Nuclear Information System (INIS)

Zeleznik, N.; Polic, M.

2000-01-01

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

Analysis on one underground nuclear waste repository rock mass in USA

International Nuclear Information System (INIS)

Ha Qiuling; Zhang Tiantian

2012-01-01

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

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

International Nuclear Information System (INIS)

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

1987-03-01

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

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)

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

International Nuclear Information System (INIS)

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

2004-01-01

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

Transient boundary conditions in the frame of THM-processes at nuclear waste repositories

Directory of Open Access Journals (Sweden)

Schanz Tom

2016-01-01

Full Text Available In nuclear waste repositories, initially unsaturated buffer is subjected to constant heat emitted by waste canister in conjunction with peripheral hydration through water from host rock. The transient hydration process can be potraied as transformation of initial heterogeneity towards homogeneity as final stage. In this context, this paper addresses the key issue of hydro mechanical behaviour of compacted buffer in context of clay microstructure and its evolution under repository relevant loading paths and material heterogeneity. This paper also introduces a unique column experiment facility available at Ruhr Universität Bochum, Germany. The facility has been designed as a forerunner of field scale testing program to simulate the transient hydration process of compacted buffer as per German reference disposal concept. The device is unique in terms of having proficiency to capture the transient material response under various possible repository relevant loading paths with higher precision level by monitor the key parameters like temperature, total suction, water content and axial & radial swelling pressure at three different sections along the length of compacted soil sample. In general, a larger spectrum of loading paths/scenarios, which may arise in the nuclear repository, can be covered precisely with existing device.

Multibarrier system preventing migration of radionuclides from radioactive waste repository

Directory of Open Access Journals (Sweden)

Olszewska Wioleta

2015-09-01

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

Safety analysis methodologies for radioactive waste repositories in shallow ground

International Nuclear Information System (INIS)

1984-01-01

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

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.

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

International Nuclear Information System (INIS)

Carlsson, Jan

2006-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

2015-10-15

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

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

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.

Geological study of radioactive waste repositories

International Nuclear Information System (INIS)

Oyama, Takahiro; Kitano, Koichi

1987-01-01

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

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

International Nuclear Information System (INIS)

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

1982-01-01

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

Study of nuclear waste storage capacity at Yucca mountain repository

International Nuclear Information System (INIS)

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

2008-01-01

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

Radiosensitivity of microorganisms isolated from radioactive waste repository

International Nuclear Information System (INIS)

Gazso, Lajos

2001-01-01

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

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

International Nuclear Information System (INIS)

Zen, E.

1980-01-01

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

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.

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

International Nuclear Information System (INIS)

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

1979-01-01

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

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

Reference concepts for the final disposal of LWR spent fuel and other high activity wastes in Spain

International Nuclear Information System (INIS)

Huertas, F.; Ulibarri, A.

1993-01-01

Studies over the last three years have been recently concluded with the selection of a reference repository concept for the final disposal of spent fuel and other high activity wastes in deep geological formations. Two non-site specific preliminary designs, at a conceptual level, have been developed; one considers granite as the host rock and the other rock salt formations. The Spanish General Radioactive Waste Program also considers clay as a potential host rock for HLW deep disposal; conceptualization for a deep repository in clay is in the initial phase of development. The salt repository concept contemplates the disposal of the HLW in self-shielding casks emplaced in the drifts of an underground facility, excavated at a depth of 850 m in a bedded salt formation. The Custos Type I(7) cask admits up to seven intact PWR fuel assemblies or 21 of BWR type. The final repository facilities are planned to accept a total of 20,000 fuel assemblies (PWR and BWR) and 50 vitrified waste canisters over a period of 25 years. The total space needed for the surface facilities amounts to 322,000 m 2 , including the rock salt dump. The space required for the underground facilities amounts to 1.2 km 2 , approximately. The granite repository concept contemplates the disposal of the HLW in carbon steel canisters, embedded in a 0.75 m thick buffer of swelling smectite clay, in the drifts of an underground facility, excavated at a depth of 55 m in granite. Each canister can host 3 PWR or 9 BWR fuel assemblies. For this concept the total number of canisters needed amounts to 4,860. The space required for the surface and underground facilities is similar to that of the salt concept. The technical principles and criteria used for the design are discussed, and a description of the repository concept is presented

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

Waste package/engineered barrier system design concepts for the direct disposal of spent fuel in the potential United States' repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Stahl, D.; Harrison, D.J.

1993-01-01

The goal of the US Department of Energy's (DOE) Yucca Mountain Site Characterization Project (YMP) waste package development program is to design a waste package and associated engineered barrier system (EBS) that meets the applicable regulatory requirements for safe disposal of spent nuclear fuel and solidified high-level waste (HLW) in a geologic repository. Attainment of this goal relies on a multi-barrier approach, the unsaturated nature of the Yucca Mountain site, consideration of technical alternatives, and sufficient resolution of technical and regulatory uncertainties. To accomplish this, an iterative system engineering approach will be used. The NWPA of 1982 limits the content of the first US repository to 70,000 metric tons of heavy metal (MTHM). The DOE Mission Plan describes the implementation of the provisions of the NWPA for the waste management system. The Draft 1988 approach will involve selecting candidate designs, evaluating them against performance requirements, and then selecting one or two preferred designs for further detailed evaluation and final design. The reference design of the waste package described in the YMP Site Characterization Plan is a thin-walled, vertical borehole-emplaced waste package with an air gap between the package and the rock wall. The reference design appeared to meet the design requirement. However, the degree of uncertainty was large. This uncertainty led to considering several more-robust design concepts during the Advanced Conceptual Design phase of the program that include small, drift-emplaced packages and higher capacity, drift-emplaced packages, both partially and totally self-shielded. Metallic as well as ceramic materials are being considered

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-07-01

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

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

International Nuclear Information System (INIS)

Vieira, Vanessa Mota; Tello, Clédola Cássia Oliveira de

2017-01-01

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

Project Guarantee 1985. Repository for high-level radioactive waste: construction and operation

International Nuclear Information System (INIS)

Anon.

1985-01-01

An engineering project study aimed at demonstrating the feasibility of constructing a deep repository for high-level waste (Type C repository) has been carried out; the study is based on a model data-set representing typical geological and rock mechanical conditions as found outside the so-called Permocarboniferous basin in the regions under investigation by Nagra in Cantons Aargau, Schaffhausen, Solothurn and Zuerich. The repository is intended for disposal of high-level waste and any intermediate-level waste from re-processing in which the concentration of long-lived alpha-emitters exceeds the permissible limits set for a Type B repository. Final disposal of high-level waste is in subterranean, horizontally mined tunnels and of intermediate-level waste in underground vertical silos. The repository is intended to accomodate a total of around 6'000 HWL-cylinders (gross volume of around 1'200 m3) and around 10'000 m3 of intermediate-level waste. The total excavated volume is around 1'100'000 m3 and a construction time for the whole repository (up to the beginning of emplacement) of around 15 years is expected. For the estimated 50-year emplacement operations, a working team of around 60 people will be needed and a team of around 160 for the simultaneous tunnelling operations and auxiliary work. The project described in the present report permits the conclusion that construction of a repository for high-level radioactive waste and, if necessary, spent fuel-rods is feasible with present-day technology

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

International Nuclear Information System (INIS)

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

1987-01-01

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

Deep repositories for waste central to uranium debate

International Nuclear Information System (INIS)

Kannegieter, T.

1991-01-01

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

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

Conceptual designs for waste packages for horizontal or vertical emplacement in a repository in salt for reference in the site characterization plan

International Nuclear Information System (INIS)

1987-06-01

This report includes the options of horizontal and vertical emplacement, the addition of a phased repository, an additional waste form (intact spent fuel), revised geotechnical data appropriate for the Deaf Smith County site, new corrosion data for the container, and new repository design data. The waste package consists of waste form and canister within a thick-walled, low-carbon steel container surrounded by packing. The container is a hollow cylinder with a flat head welded to each end. The design concepts for the waste container or vertical and horizontal emplacement are identical. This report discusses the results of analyses of aspects of the reference waste package concept needing changes because of new data and information believed applicable to the Deaf Smith County site. Included are waste package conceptual designs or (1) the reference defense high-level waste form from the Savannah River Plant; (2) intact spent fuel with our pressurized-water-reactor or nine boiling-water-reactor assemblies per package for emplacement during Phase 1 of repository operation; and (3) spent fuel which has been disassembled and consolidated into a segmented cylindrical canister with rods from either 12 pressurized-water-reactor or 30 boiling-water-reactor assemblies per package for emplacement during Phase 2. 30 refs., 61 figs., 30 tabs

Concept and Planning of Site Preparation for Radioactive Waste Disposal in Jawa and Surrounding Area

International Nuclear Information System (INIS)

Heru Sriwahyuni; Sastrowardoyo, Pratomo B.; Teddy Sumantri; Dewi Susilowati; Hendra Adhi Pratama; Syarmufni, A.

2008-01-01

Concept and planning for radioactive waste disposal in Jawa and surrounding area have been done. These activities were part of the investigation for preparation of repository location in Jawa. In this report, the summary of previous sitting activities, the waste inventory in Radioactive Waste Technology Centre, and list of important factors for sitting on radioactive waste disposal location. Several potential areas such as Karawang, Subang, Majalengka, Rembang, Tuban, Madura will be the focus for next activities. The result will be part of activities report regarding the preparation of repository location in Jawa and surrounding area, that will be used as recommendation prior to radioactive waste management policy. (author)

Performance of high level waste forms and engineered barriers under repository conditions

International Nuclear Information System (INIS)

1991-02-01

The IAEA initiated in 1977 a co-ordinated research programme on the ''Evaluation of Solidified High-Level Waste Forms'' which was terminated in 1983. As there was a continuing need for international collaboration in research on solidified high-level waste form and spent fuel, the IAEA initiated a new programme in 1984. The new programme, besides including spent fuel and SYNROC, also placed greater emphasis on the effect of the engineered barriers of future repositories on the properties of the waste form. These engineered barriers included containers, overpacks, buffer and backfill materials etc. as components of the ''near-field'' of the repository. The Co-ordinated Research Programme on the Performance of High-Level Waste Forms and Engineered Barriers Under Repository Conditions had the objectives of promoting the exchange of information on the experience gained by different Member States in experimental performance data and technical model evaluation of solidified high level waste forms, components of the waste package and the complete waste management system under conditions relevant to final repository disposal. The programme includes studies on both irradiated spent fuel and glass and ceramic forms as the final solidified waste forms. The following topics were discussed: Leaching of vitrified high-level wastes, modelling of glass behaviour in clay, salt and granite repositories, environmental impacts of radionuclide release, synroc use for high--level waste solidification, leachate-rock interactions, spent fuel disposal in deep geologic repositories and radionuclide release mechanisms from various fuel types, radiolysis and selective leaching correlated with matrix alteration. Refs, figs and tabs

Salt Repository Project Waste Package Program Plan: Draft

International Nuclear Information System (INIS)

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

1986-01-01

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

Performance Assessment of a Generic Repository in Bedded Salt for DOE-Managed Nuclear Waste

Science.gov (United States)

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

2016-12-01

A mined repository in salt is one of the concepts under consideration for disposal of DOE-managed defense-related spent nuclear fuel (SNF) and high level waste (HLW). Bedded salt is a favorable medium for disposal of nuclear waste due to its low permeability, high thermal conductivity, and ability to self-heal. Sandia's Generic Disposal System Analysis framework is used to assess the ability of a generic repository in bedded salt to isolate radionuclides from the biosphere. The performance assessment considers multiple waste types of varying thermal load and radionuclide inventory, the engineered barrier system comprising the waste packages, backfill, and emplacement drifts, and the natural barrier system formed by a bedded salt deposit and the overlying sedimentary sequence (including an aquifer). The model simulates disposal of nearly the entire inventory of DOE-managed, defense-related SNF (excluding Naval SNF) and HLW in a half-symmetry domain containing approximately 6 million grid cells. Grid refinement captures the detail of 25,200 individual waste packages in 180 disposal panels, associated access halls, and 4 shafts connecting the land surface to the repository. Equations describing coupled heat and fluid flow and reactive transport are solved numerically with PFLOTRAN, a massively parallel flow and transport code. Simulated processes include heat conduction and convection, waste package failure, waste form dissolution, radioactive decay and ingrowth, sorption, solubility limits, advection, dispersion, and diffusion. Simulations are run to 1 million years, and radionuclide concentrations are observed within an aquifer at a point approximately 4 kilometers downgradient of the repository. The software package DAKOTA is used to sample likely ranges of input parameters including waste form dissolution rates and properties of engineered and natural materials in order to quantify uncertainty in predicted concentrations and sensitivity to input parameters. Sandia

Elicitation and use of expert judgment in performance assessment for high-level radioactive waste repositories

International Nuclear Information System (INIS)

Bonano, E.J.; Hora, S.C.; Keeney, R.L.; von Winterfeldt, D.

1990-05-01

This report presents the concept of formalizing the elicitation and use of expert judgment in the performance assessment of high-level radioactive waste (HLW) repositories in deep geologic formations. The report begins with a discussion of characteristics (advantages and disadvantages) of formalizing expert judgment examples of previous uses of expert judgment in radioactive waste programs, criteria that can assist in deciding when to formalize expert judgment, and the relationship of formal use of expert judgment to data collection and modeling. The current state of the art with respect to the elicitation, use, and communication of formal expert judgment is presented. The report concludes with a discussion on potential applications of formal expert judgment in performance assessment of HLW repositories. 93 refs

Citizen participation in nuclear waste repository siting

International Nuclear Information System (INIS)

Howell, R.E.; Olsen, D.

1982-12-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2017-11-15

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

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

International Nuclear Information System (INIS)

Graf, A.; Merx, H.

2003-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

2003-07-01

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

Methodology and applicability of a safety and demonstration concept for a HAW final repository on clays. Safety concept and verification strategy

International Nuclear Information System (INIS)

Ruebel, Andre; Meleshyn, Artur

2014-08-01

The report describes the site independent frame for a safety concept and verification strategy for a final repository for heat generating wastes in clay rock. In the safety concept planning specifications and technical measures are summarized that are supposed to allow a safe inclusion of radionuclides in the host rock. The verification strategy defines the systematic procedures for the development of fundamentals and scenarios as basis for the demonstration of the safety case and to allow the prognosis of appropriateness. The report includes the boundary conditions, the safety concept for the post-closure phase and the verification strategy for the post-closure phase.

A Study on Establishment of Buffer Zone of Radioactive Waste Repository

International Nuclear Information System (INIS)

Yoon, Jeong Hyoun; Park, Joo Wan; Ju, Min Su; Kim, Chang Lak; Park, Jin Baek

2008-01-01

A new proposed repository has a final capacity of 800,000 drums radioactive waste. Most of foreign repositories have a general practice of segregating control zones which mainly contributes to classification of degree of control, whether it is called buffer zone or not. Domestic regulatory requirements of establishment of buffer zone in a repository are not much different from those of nuclear power plants for operation period, in which satisfactory design objective or performance objective is the most important factor in determination of the buffer zone. The meaning of buffer zone after closure is a minimum requested area which can prevent inadvertent intruders from leading to non-allowable exposure during institutional control period. Safety assessment with drinking well scenario giving rise to the highest probability of exposure among the intruder's actions can verify fulfillment of the buffer zone which is determined by operational safety of the repository. At present. for the repository to be constructed in a few years, the same procedure and concept as described in this paper are applied that can satisfy regulatory requirements and radiological safety as well. However, the capacity of the repository will be stepwise extended upto 800,000 drums, consequently its layout will be varied too. Timely considerations will be necessary for current boundary of the buffer zone which has been established on the basis of 100,000 drums disposal.

The German quality system for waste repositories

International Nuclear Information System (INIS)

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

1993-01-01

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

Radioactive waste transport to a Nirex deep repository

International Nuclear Information System (INIS)

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

1989-01-01

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

Development and application of a quality assurance system for waste repositories

International Nuclear Information System (INIS)

Beckmerhagen, I.; Berg, H.P.

1996-01-01

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

Thermal analysis of a heat generating waste repository on the seabed

International Nuclear Information System (INIS)

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

1987-02-01

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

National waste terminal storage repository in a bedded salt formation for spent unreprocessed fuel. Volume I. Conceptual design report

International Nuclear Information System (INIS)

1978-12-01

In February 1976, the Energy Research and Development Administration (ERDA), now the Department of Energy (DOE), established a National Waste Terminal Storage (NWTS) program. As a part of this program, two parallel conceptual design efforts were initiated in January 1977. One was for deep geologic storage, in domed salt, of high level waste resulting from the reprocessing of spent fuel. The other was for deep geologic storage of unreprocessed spent fuel in bedded salt. These two concepts are identified as NWTS Repository 1 and Repository 2, respectively. Repository 2 (NWTSR2) is the concept which is covered by this Conceptual Design Report. Volume I of the conceptual design report contains the following information: physical description of the report; project purpose and justification; principal safety, fire, and health hazards; environmental impact considerations; quality assurance considerations; assessment of operational interfaces; assessment of research and development interfaces; project schedule; proposed method of accomplishment; summary cost estimate; and outline specifications. The conceptual design for Repository 2 was developed in sufficient detail to permit determination of scope, engineering feasibility, schedule, and cost estimates, all of which are necessary for planning and budgeting the project

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

International Nuclear Information System (INIS)

2003-01-01

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

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

International Nuclear Information System (INIS)

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

2004-01-01

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

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

International Nuclear Information System (INIS)

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

1983-01-01

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

Multi criteria decision analysis on a waste repository in Mol

International Nuclear Information System (INIS)

Carle, B.

2005-01-01

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

Final repository search together with the citizens. Information, consultation, dialogue, participation

International Nuclear Information System (INIS)

Mueller, Monika C.M.

2013-01-01

The documentation on the Loccum meeting 2013 includes contributions on the following topics: Public participation for the final repository search; Lessons learned from the past; Public participation: what is expected? Experiences of repository operators on public participation; The TRIPLEX concept; From Gorleben to the law on final repository search: a long and a short story; Public participation concerning radioactive waste storage; The public has to be informed on the radioactive waste problem and the possible solutions; After consensus is before consensus - German final repository conflict between legislation and simulated public participation; Political concept of public participation; A fast final repository law will not bring about social peace; Good public participation on final repository search - requirements, challenges, questions and approaches.

Investigation on long-term safety aspects of a radioactive waste repository in a diagenic clay formation. Final report

Energy Technology Data Exchange (ETDEWEB)

Jobmann, M.; Gazul, R. [DBE Technology GmbH, Peine (Germany); Fluegge, J. [Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) gGmbH, Braunschweig (Germany); and others

2017-03-28

The report presents the sealing concept developed for a Russian near surface low/intermediate level (LILW) waste repository at the ''radon site'' in the lower Cambrian ''blue clay'' formation. The radioactive wastes will be transported to the repository through a tunnel that will connect the underground disposal areas with the surface facilities. Two ventilation shafts for fresh and exhaust air will also connect the underground facilities with the surface. Specific characteristics of the flow regime in the studied area have been simulated. For the construction of a potential repository site it is necessary to know the possible contaminant transport paths to the surface and the biosphere. Due to the lack of sufficient data the calculation can only indicate tendencies that can trigger future explorations. Simulations of the radionuclide (C-14, Cl-36, Se-79, I-129) release from the repository in the liquid phase show a similar behavior as for other repositories in clay. Probabilistic simulations show a large variation of obtained results as a result of the parameter uncertainty.

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

Reconstruction and modernization of Novi Han radioactive waste repository

International Nuclear Information System (INIS)

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

2000-01-01

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

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)

Repository design

Energy Technology Data Exchange (ETDEWEB)

John, C M

1982-01-01

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

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

Stabilities of nuclear waste forms and their geochemical interactions in repositories

International Nuclear Information System (INIS)

White, W.B.

1980-01-01

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

Supply-side approach to nuclear waste repositories

International Nuclear Information System (INIS)

Harmon, L.H.

1985-01-01

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

Modelling approach to LILW-SL repository safety evaluation for different waste packing options

International Nuclear Information System (INIS)

Perko, Janez; Mallants, Dirk; Volckaert, Geert; Towler, George; Egan, Mike; Virsek, Sandi; Hertl, Bojan

2007-01-01

The key objective of the work described here was to support the identification of a preferred disposal concept and packaging option for low and short-lived intermediate level waste (LILW-SL). The emphasis of the assessment, conducted on behalf of the Slovenian radioactive waste management agency (ARAO), was the consideration of several waste treatment and packaging options in an attempt to identify optimised containment characteristics that would result in safe disposal, taking into account the cost-benefit of alternative safety measures. Waste streams for which alternative treatment and packaging solutions were developed and evaluated include decommissioning waste and NPP operational wastes, including drums with unconditioned ion exchange resins in over-packed tube type containers (TTCs). For decommissioning wastes, the disposal options under consideration were either direct disposal of loose pieces grouted into a vault or use of high integrity containers (HIC). In relation to operational wastes, three main options were foreseen. The first is over-packing of resin containing TTCs grouted into high integrity containers, the second option is complete treatment with hydration, neutralization, and cementation of the dry resins into drums grouted into high integrity containers and the third is direct disposal of TTCs into high integrity containers without additional treatment. The long-term safety of radioactive waste repositories is usually demonstrated with the support of a safety assessment. This normally includes modelling of radionuclide release from a multi-barrier near-surface or deep repository to the geosphere and biosphere. For the current work, performance assessment models were developed for each combination of siting option, repository design and waste packaging option. Modelling of releases from the engineered containment system (the 'near-field') was undertaken using the AMBER code. Detailed unsaturated water flow modelling was undertaken using the

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

The design of the Bulgaria rad waste repository

International Nuclear Information System (INIS)

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

2012-01-01

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

NF-PRO research on a repository for vitrified waste and spent fuel

International Nuclear Information System (INIS)

Sneyers, A.

2006-01-01

NF-PRO is a four-year (2004-2007) Integrated Project supported by funding under the Sixth Research (EURATOM) Programme of the European Commission. NF-PRO is coordinated by SCK C EN and investigates key processes in the near-field of geological repositories for the disposal of high-level vitrified waste and spent nuclear fuel. The near-field of a geological repository consists of the area surrounding the waste packages and is composed of several engineered barriers that enclose and confine the disposed waste. These barriers include the waste form, the waste canisters, backfills, seals, plugs and the part of the host rock that has been modified by the excavation of the repository. In all repository designs under investigation within EU Member States, the near-field plays an important role in ensuring the overall safety of disposal: its principal function is to retain radionuclides over extended periods of time and to minimise their release from the waste to the host rock. The main objective of NF-PRO is to integrate European research on the near field with the aim of enhancing common understanding of the long-term changes taking place in a deep repository. NF-PRO assesses how these changes affect the containment of the disposed radioactive waste. Knowledge generated by the project can be applied in waste management programmes to optimise repository designs and to make barriers functional and resource-efficient. The integration of results from detailed process studies in assessments on the overall near-field system performance is a key objective of NF-PRO. The level of integration envisaged by NF-PRO has not yet been achieved in earlier research projects supported by the European Commission. Accordingly, NF PRO represents a major step forward in the establishing of the scientific and technical basis for geological disposal and the safe management of radioactive wastes

Integrated management system for radioactive waste repositories (SGI3R)

International Nuclear Information System (INIS)

Silva, Fabio; Tello, Cledola Cassia Oliveira de

2009-01-01

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

Rock mechanics for hard rock nuclear waste repositories

International Nuclear Information System (INIS)

Heuze, F.E.

1981-09-01

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

Buoyancy flow in fractures intersecting a nuclear waste repository

International Nuclear Information System (INIS)

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

1980-07-01

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

Underground excavation methods for a high-level waste repository

International Nuclear Information System (INIS)

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

1990-01-01

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

Aspects on the gas generation and migration in repositories for high level waste in salt formations

International Nuclear Information System (INIS)

Ruebel, Andre; Buhmann, Dieter; Meleshyn, Artur; Moenig, Joerg; Spiessl, Sabine

2013-07-01

In a deep geological repository for high-level waste, gases may be produced during the post-closure phase by several processes. The generated gases can potentially affect safety relevant features and processes of the repository, like the barrier integrity, the transport of liquids and gases in the repository and the release of gaseous radionuclides from the repository into the biosphere. German long-term safety assessments for repositories for high-level waste in salt which were performed prior 2010 did not explicitly consider gas transport and the consequences from release of volatile radionuclides. Selected aspects of the generation and migration of gases in repositories for high-level waste in a salt formation are studied in this report from the viewpoint of the performance assessment. The knowledge on the availability of water in the repository, in particular the migration of salt rock internal fluids in the temperature field of the radioactive waste repository towards the emplacement drifts, was compiled and the amount of water was roughly estimated. Two other processes studied in this report are on the one hand the release of gaseous radionuclides from the repository and their potential impact in the biosphere and on the other hand the transport of gases along the drifts and shafts of the repository and their interaction with the fluid flow. The results presented show that there is some gas production expected to occur in the repository due to corrosion of container material from water disposed of with the backfill and inflowing from the host rock during the thermal phase. If not dedicated gas storage areas are foreseen in the repository concept, these gases might exceed the storage capacity for gases in the repository. Consequently, an outflow of gases from the repository could occur. If there are failed containers for spent fuel, radioactive gases might be released from the containers into the gas space of the backfill and subsequently transported together

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

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

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)

Final disposal of radioactive wastes in Switzerland: concept and overview of Project Guarantee 1985

International Nuclear Information System (INIS)

Anon.

1985-01-01

The validity of the operational licences of the existing Swiss nuclear power plants (NPP) Beznau I and II, Muehleberg, Goesgen and Leibstadt after 31st. December 1985 is, because of official requirements, dependent on the demonstration of permanent, safe management and final disposal of radioactive waste. For this purpose, the NPP companies have to prepare a so-called guarantee project and present this to the Bundesrat for review. The appropriate investigations and research have been carried out by Nagra (National Cooperative for the Storage of Radioactive Waste). The 1985 Project Gewaehr (Guarantee) is described in an eight volume report NGB 85-01 to 85-08 and individual research projects are reported on in separate NTB-series reference reports. The present volume NGB 85-01 takes the form of a self-contained project overview in which the concepts for nuclear waste management are described, the contents of the remaining volumes NGB 85-02 to 85-08 are summarized and Project conclusions are drawn from Project Gewaehr 1985. Project Gewaehr 1985 covers two repository types: Type C repository for high-level and certain alpha-containing intermediate-level waste, and Type B repository for all remaining intermediate- and low-level waste. The Project shows in detail that technical feasibility of final disposal can be assumed given presently available methods, that the technical safety barriers show a high level of efficiency and that suitable geological options are available to ensure long-term safety in Switzerland as the concept is defined by official requirements. The Project safety analyses show that the chosen disposal concepts assure the protection of mankind and the environment under all realistically anticipated conditions

Research on swelling clays and bitumen as sealing materials for radioactive waste repositories

International Nuclear Information System (INIS)

Allison, J.A.; Wilson, J.; Mawditt, J.M.; Hurt, J.C.

1991-01-01

This report describes a programme of research to investigate the performance of composite seals incorporating adjacent blocks of swelling clay and bitumen. It is shown that the interaction of the materials can promote a self-sealing mechanism which prevents water penetration, even when defects are present in the bitumen layer. A review of the swelling properties of highly compacted bentonite and magnesium oxide is presented, and the characteristic sealing properties of bituminous materials are described. On the basis of this review, it is concluded that bentonite is the preferred candidate material for use in composite clay/bitumen seals for intermediate-level radioactive waste repositories. However, it is thought that magnesium oxide may have other sealing applications for high-level waste repositories. A programme of laboratory experiments is described in which relevant swelling and intrusion properties of highly compacted bentonite blocks and the annealing characteristics of oxidised and hard-grade industrial bitumens are examined. The results of composite sealing experiments involving different water penetration routes are reported, and factors governing the mechanism of self-sealing are described. The validation of the sealing concept at a laboratory scale indicates that composite bentonite/bitumen seals could form highly effective barriers for the containment of radioactive wastes. Accordingly, recommendations are made concerning the development of the research, including the implementation of full-scale demonstration experiments to simulate conditions in an underground repository. 13 tabs., 41 figs., 62 refs

High-level waste repository-induced effects

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

High-level waste repository-induced effects

International Nuclear Information System (INIS)

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

2016-10-01

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

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-12-01

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

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

International Nuclear Information System (INIS)

Eriksson, Leif G.

1999-01-01

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

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

International Nuclear Information System (INIS)

Perkins, C.

2003-01-01

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

Rock mass modification around a nuclear waste repository in welded tuff

International Nuclear Information System (INIS)

Mack, M.G.; Brandshaug, T.; Brady, B.H.

1989-08-01

This report presents the results of numerical analyses to estimate the extent of rock mass modification resulting from the presence of a High Level Waste (HLW) repository. Changes in rock mass considered are stresses and joint deformations resulting from disposal room excavation and thermal efffects induced by the heat generated by nuclear waste. rock properties and site conditions are taken from the Site Characterization Plan Conceptual Design Report for the potential repository site at Yucca Mountain, Nevada. Analyses were conducted using boundary element and distinct element methods. Room-scale models and repository-scale models were investigated for up to 500 years after waste emplacement. Results of room-scale analyses based on the thermoelastic boundary element model indicate that a zone of modified rock develops around the disposal rooms for both vertical and horizontal waste emplacement. This zone is estimated to extend a distance of roughly two room diameters from the room surface. Results from the repository-scale model, which are based on the thermoelastic boundary element model and the distinct element model, indicate a zone with modified rock mass properties starting approximately 100 m above and below the repository, with a thickness of approximately 200 m above and 150 m below the repository. Slip-prone subhorizontal features are shown to have a substantial effect on rock mass response. The estimates of rock mass modification reflect uncertainties and simplifying assumptions in the models. 32 refs., 57 figs., 1 tab

Fair rules for siting a high-level nuclear waste repository

International Nuclear Information System (INIS)

Easterling, D.

1992-01-01

Geologic repositories are designed to resolve the ever-growing problem of high-level nuclear waste, but these facilities invite intense local opposition due to the perceived severity of the risks and the possibility of stigma effects. This analysis examines whether the perceived fairness of the siting process affects local residents' support for hosting a repository. In particular, a survey of 1,001 Nevada residents is used to test the hypothesis that an individual's willingness to accept a local repository will increase if he or she is convinced that this is the safest disposal option available. A logistic analysis indicates that beliefs regarding relative suitability have an independent effect on the acceptability of a local repository (i.e., Yucca Mountain). The article then considers the question of how to implement an optimizing strategy for siting facilities, comparing an idealized strategy against the original Nuclear Waste Policy Act (NWPA) of 1982 and the Amendments Act of 1987. Although choosing the safest site seems as if it could enhance public acceptance of the repository program, there is currently little prospect of identifying the best option to the high-level waste problem and, as a results, little chance of gaining the public support that is necessary to promote a successful siting outcome. 81 refs., 1 fig., 5 tabs

A Deterministic Safety Assessment of a Pyro-processed Waste Repository

International Nuclear Information System (INIS)

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

2012-01-01

A GoldSim template program for a safety assessment of a hybrid-typed repository system, called 'A-KRS', in which two kinds of pyro-processed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyro-processing of PWR nuclear spent fuels are disposed of, has been developed. This program is ready both for a deterministic and probabilistic total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios. The A-KRS has been deterministically assessed with 5 various normal and abnormal scenarios associated with nuclide release and transport in and around the repository. Dose exposure rates to the farming exposure group have been evaluated in accordance with all the scenarios and then compared among other.

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

International Nuclear Information System (INIS)

Jardine, L.J.

1990-01-01

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

Low and intermediate level waste repositories: public involvement aspects

International Nuclear Information System (INIS)

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

2009-01-01

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

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

International Nuclear Information System (INIS)

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

2001-11-01

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

Extreme scenarios for nuclear waste repositories

Energy Technology Data Exchange (ETDEWEB)

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

1982-09-01

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

Improvement of storage conditions and closure of the radioactive waste repository - Rozan

International Nuclear Information System (INIS)

Dutton, L.M.C.; Pacey, N.R.; Buckley, M.J.; Thomson, J.G.; Miller, W.; Barraclough, I.; Tomczak, W.; Mitrega, J.; Smietanski, L.

2005-01-01

The Rozan repository is a near-surface repository on the site of an ex-military fort, operated by Radioactive Waste Management Plant (RWMP). Solid or encapsulated waste is consigned to the repository. Low- and medium-activity waste produced in Poland is collected, processed, solidified and prepared for disposal at the Swierk facility. The waste is currently stored or disposed of within the fort structures, these have robust concrete walls, that provide both shielding and containment. The project, funded by the European Commission through the Phare Programme, aimed to improve the storage conditions and determine a strategy for closure achieving two key results; Stakeholder agreement to a strategy for the management and closure of the repository, and; Approval by the National Atomic Energy Agency of the safety case for the selected strategy. The strategy was selected using a multi-criteria analysis methodology at workshops that involved experts, regulators and other stakeholders. The selected strategy proposed that the waste in Facilities 3A and 8 should be left in situ and these facilities should continue to operate until the repository is closed. The waste in Rooms K7 to K9 of Facility 1 and in Facilities 2 and 3 should be retrieved, assayed, treated and packaged prior to redisposal. The short-lived waste that is retrieved from Rooms K7 to K9 of Facility 1 and Facilities 2 and 3 should be emplaced in Facility 8 subject to acceptance by the NAEA of the dose of 0.3mSv/y that might occur at long times in the future from a very unlikely scenario. When operations at the repository end, Facilities 3A and 8 should be covered with a multi-layer cap. Following selection of the strategy, assessment work was undertaken to support the production of the suite of safety cases. (author)

Optimized application of systems engineering to nuclear waste repository projects

International Nuclear Information System (INIS)

Miskimin, P.A.; Shepard, M.

1986-01-01

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

The radioactive waste management concept: problem definition and solving in Latvia

International Nuclear Information System (INIS)

Dreimanis, A.; Shatrovska, D.

2003-01-01

Development of radioactive waste (RW) management concept is treated as a key component of a general process - elaboration of the overall RW management strategy for a certain country/region. We present indication of possible solutions for crucial RW management problems for Latvia being in the same time rather generic for other countries. The importance of the Concept for Latvia follows from the planned decommissioning of the Salaspils Research Reactor (SRR) and from the recommended further upgrading of RW management organization in conditions of limited resources.The aim of this Concept is to stimulate the development of advanced, environmentally sound and population friendly system of RW management, in accord with the fair social system for the protection of human health and the environment, in line of international recommendations.The Concept foresees solutions for the safe management of RW for the period 2003-2010. The main problems to be analysed and solved in the Concept: 1.The increase of the RW quantity and a lack of the sufficient storage space. In addition to the traditional producers of RW such as medicine, industry, and science, there are two major operators in Latvia that have significantly increase the yearly amount of RW for disposal in recent years and will do so in nearest future - disposal off of the SRR decommissioning waste in the existing near-surface LILW-SL RW repository, which dictates the need for its enlargement. 2. The safety of the existent repository. To ensure protection of population and environment (including the Baltic sea) from exposure and radioactive contamination, proper measures shall be taken. The safety of RW repository should be upgraded via building long-term cover, according to recommendations of safety assessment (SA) by consortium CASSIOPEA. 3. Construction of a long term storage and the geological disposal site. Safe isolation of long-lived RW can be achieved by storage in the geological disposal site only, thereby; a

Low- and intermediate-level waste repository-induced effects

Energy Technology Data Exchange (ETDEWEB)

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

2016-10-15

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

Low- and intermediate-level waste repository-induced effects

International Nuclear Information System (INIS)

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

2016-10-01

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

Preliminary waste acceptance requirements - Konrad repository project

International Nuclear Information System (INIS)

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

1991-01-01

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

Types of safety assessments of near surface repository for radioactive waste

International Nuclear Information System (INIS)

Mateeva, M.

2004-01-01

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

Repository-analog experiments of nuclear waste leaching and migration

International Nuclear Information System (INIS)

Seitz, M.G.

1982-01-01

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

The conceptual design of waste repository for radioactive waste from medical, industrial and research facilities containing comparatively high radioactivity

International Nuclear Information System (INIS)

Yamamoto, Masayuki; Hashimoto, Naro

2002-02-01

Advisory Committee on Nuclear Fuel Cycle Backend Policy reported the basic approach to the RI and Institute etc. wastes on March 2002. According to it, radioactive waste form medical, industrial and research facilities should be classified by their radioactivity properties and physical and chemical properties, and should be disposed in the appropriate types of repository with that classification. For the radioactive waste containing comparatively high radioactivity generated from reactors, NSC has established the Concentration limit for disposal. NSC is now discussing about the limit for the radioactive waste from medical, industrial and research facilities containing comparatively high radioactivity. Japan Nuclear Cycle Development Institute (JNC) preliminary studied about the repository for radioactive waste from medical, industrial and research facilities and discussed about the problems for design on H12. This study was started to consider those problems, and to develop the conceptual design of the repository for radioactive waste from medical, industrial and research facilities. Safety assessment for that repository is also performed. The result of this study showed that radioactive waste from medical, industrial and research facilities of high activity should be disposed in the repository that has higher performance of barrier system comparing with the vault type near surface facility. If the conditions of the natural barrier and the engineering barrier are clearer, optimization of the design will be possible. (author)

Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

Energy Technology Data Exchange (ETDEWEB)

Van Konynenburg, R.A.; Halsey, W.G.; McCright, R.D.; Clarke, W.L. Jr. [Lawrence Livermore National Lab., CA (United States); Gdowski, G.E. [KMI, Inc., Albuquerque, NM (United States)

1993-02-01

Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices.

Selection of candidate container materials for the conceptual waste package design for a potential high level nuclear waste repository at Yucca Mountain

International Nuclear Information System (INIS)

Van Konynenburg, R.A.; Halsey, W.G.; McCright, R.D.; Clarke, W.L. Jr.; Gdowski, G.E.

1993-02-01

Preliminary selection criteria have been developed, peer-reviewed, and applied to a field of 41 candidate materials to choose three alloys for further consideration during the advanced conceptual design phase of waste package development for a potential high level nuclear waste repository at Yucca Mountain, Nevada. These three alloys are titanium grade 12, Alloy C-4, and Alloy 825. These selections are specific to the particular conceptual design outlined in the Site Characterization Plan. Other design concepts that may be considered in the advanced conceptual design phase may favor other materials choices

Thermal modeling for a potential high-level nuclear waste repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Pruess, K.; Tsang, Y.

1994-03-01

Repository performance models based on numerical simulation of fluid and heat flows have recently been developed by several different groups. Model conceptualizations generally focus on large-scale average behavior. This comparison finds that current performance assessment (PA) models use generally similar approximations and parameters. Certain differences exist in some performance-relevant parameters, especially absolute permeabilities, characteristic curves, and thermal conductivities. These reflect present uncertainties about the most appropriate parameters applicable to Yucca Mountain and must be resolved through future field observations and laboratory measurements. For a highly heterogeneous fractured-porous hydrogeologic system such as Yucca Mountain, water infiltration through the unsaturated zone is expected to be dominated by highly localized phenomena. These include fast channelized flow along preferential paths in fractures, and frequent local ponding. The extended dry repository concept proposed by the Livermore group is reviewed. Predictions of large-scale drying around the repository on the average for large thermal loads cannot be taken to indicate that waste packages will not be contacted by liquid water, and that aqueous-phase transport of contaminants is not possible. Specifically, the authors find that modest water infiltration, on the order of a few millimeters per year, would be sufficient to overwhelm the vaporization capacity of the repository heat and inundate the waste packages within a time frame of a few thousand years. A preliminary analysis indicates that channelized flow of water may persist over large vertical distances. The vaporization-condensation cycle has a capacity for generating huge amounts of ponded water. A small fraction of the total condensate, if ponded and then episodically released, would be sufficient to cause liquid phase to make contact with the waste packages

Barriers to migration of radionuclides from radioactive waste repositories

International Nuclear Information System (INIS)

Stefanova, I.

1999-01-01

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

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

International Nuclear Information System (INIS)

Jones, K.A.

1982-01-01

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

Underground disposal of UK heat-generating wastes: repository design considerations

International Nuclear Information System (INIS)

Steadman, J.A.

1993-12-01

The report discusses the likely differences in design between a deep repository for disposal of UK heat-generating radioactive wastes and that of the planned Nirex ILW/LLW repository at Sellafield, based on a review of international published information. The main differences arise from the greater heat and radiation outputs of the waste, and in the case of intact PWR spent fuel elements, the greater length and weight of the disposal packages. Published cost estimates for other OECD countries for disposal of heat-generating wastes are considerably lower than that for the UK, partly because in most cases they are for co-disposal with a larger quantity of ILW. (author)

Extreme scenarios for nuclear waste repositories

Energy Technology Data Exchange (ETDEWEB)

Brown, M J; Crouch, E

1982-09-01

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

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

Assessments of the thermal evolution for a radioactive waste final repository using analytical methods

International Nuclear Information System (INIS)

Radut, A. C.; Roman, M. R.; Florea, S.; Ionescu, D. V.; Olteanu, G.; Valeca, S.

2016-01-01

In the designing process for a radioactive final repository concept, the temperature evolution over time is a significant issue for the stability and long-term safety of entire emplacement. In particular, the maximum value of temperature in the whole structure, during time, must not exceed a certain safety value which depends, beside other criteria, on the bulk material of the repository. A computer code TEMPROC, based on analytical model for the transient thermal heat conduction, described in this paper, was developed inside ''Fuel Performance''Department from ICN Pitesti, in order to evaluate the waste repository's temperature distribution. The program was developed under ''Microsoft FORTRAN Power Station''platform that provides IMSL subroutines library support for numeric algorithm. So the program is relative small, with a good calculus speed. The numerical results obtained with TEMPROC computer code, have been acceptably compared with similar existing data from scientific literature [1]. (authors)

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

International Nuclear Information System (INIS)

Doering, Thomas; Pasupathi, V.

2002-01-01

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

Engineered barrier development for a nuclear waste repository in basalt

International Nuclear Information System (INIS)

Smith, M.J.

1980-05-01

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

Building on existing institutions to perpetuate knowledge of waste repositories

International Nuclear Information System (INIS)

Weitzberg, A.

1982-08-01

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

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

International Nuclear Information System (INIS)

Buser, M.

2010-05-01

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

Waste package for a repository located in salt

International Nuclear Information System (INIS)

Basham, S.J. Jr.

1983-01-01

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

Nye County, Nevada 1992 nuclear waste repository program: Program overview. Final report

International Nuclear Information System (INIS)

1998-01-01

The purpose of this document is to provide an overview of the Nye County FY92 Nuclear Waste Repository Program (Program). Funds to pay for Program costs will come from the Federal Nuclear Waste Fund, which was established under the Nuclear Waste Policy Act of 1982 (NWPA). In early 1983, the Yucca Mountain was identified as a potentially suitable site for the nation's first geologic repository for spent reactor fuel and high-level radioactive waste. Later that year, the Nye County Board of County Commissioners (Board) established the capability to monitor the Federal effort to implement the NWPA and evaluate the potential impacts of repository-related activities on Nye County. Over the last eight years, the County's program has grown in complexity and cost in order to address DOE's evolving site characterization studies, and prepare for the potential for facility construction and operation. Changes were necessary as well, in response to Congress's redirection of the repository program specified in the amendments, to the NWPA approved in 1987. In early FY 1991, the County formally established a project office to plan and implement its program of work. The Repository Project Office's (RPO) mission and functions are provided in Section 2.0. The RPO organization structure is described in Section 3.0

Retrieval effects on ventilation and cooling requirements for a nuclear waste repository

International Nuclear Information System (INIS)

Hambley, D.F.

1985-01-01

The Nuclear Waste Policy Act of 1982 (Public Law 97-425) and the regulations promulgated in Title 10, Part 60 of the Code of Federal Regulations (10CFR60) by the US Nuclear Regulatory Commission (NRC) for an underground repository for spent fuel and high level nuclear waste (HLW) require that it is possible to retrieve waste, for whatever reason, from such a facility for a period of 50 years from initial storage or until the completion of the performance confirmation period, whichever comes first. This paper considers the effects that the retrievability option mandates on ventilation and cooling systems required for normal repository operations. An example is given for a hypothetical repository in salt. 18 refs., 1 tab

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)

Crop - a project for comparative description of national concepts for disposal of radioactive waste

International Nuclear Information System (INIS)

Pusch, R.; Svemar, Ch.

2003-01-01

Nine partners representing Sweden (SKB), Belgium (SCK-CEN). Finland (POSIVA). France (Andra). Germany (GRS), Switzerland (NAGRA), Spain (ENRESA). Canada (OPG), and the US (DOECBFO) participate in the EC-supported project CROP, which is the synonym for Cluster Repository Project and aims at describing the various repository concepts for identifying similarities and differences. The ambition is to assist designers and modelers in the development of the respective concepts. Design, construction and instrumentation of underground laboratories (URLs) and forthcoming repositories as well as modeling the engineered performance of national repository concepts in crystalline rock, salt and clay are defined and compared. The depth of location of the repositories is different - 250 to 1000 m- and also the design: the multi-barrier philosophy is proposed for disposal in all types of rock but for salt the geological medium is considered to be the major barrier. The minimum time for effective isolation of the waste differs among national programs (E4 to E6 years) and so is the effort of modeling physical and chemical degradation of the engineered barrier system (EBS), which consists of canisters, embedding buffer and backfill, and plugs. CROP is focusing on the buffer and backfill and shaft, tunnel and borehole seals including plugs. The temperature in the near-field is a most important factor for the repository performance. It will be in the interval 90-110 deg C for crystalline rock and clay, and up to 200 deg C for salt in the close vicinity of the waste according to the concepts, attenuating with increased distance from it. The heat and temperature gradient affects the groundwater flow and rock strain and thereby the evolution of the EBS in the first few hundred years and they are determinants of the chemical stability and hence required dimensions of the engineered barriers. Both the short- and long-term performance of the EBS are significantly affected by the groundwater

Appraisal of hard rock for potential underground repositories of radioactive wastes

International Nuclear Information System (INIS)

Cook, N.G.W.

1977-10-01

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

Radiological consequence analysis of a repository for radioactive waste

International Nuclear Information System (INIS)

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

1982-01-01

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

EBS modelling for the development of repository concepts tailored to siting environments

International Nuclear Information System (INIS)

Ishiguro, K.; Ueda, H.; Wakasugi, K.; Sakabe, Y.; Kitayama, K.; Umeki, H.; Takase, H.

2007-01-01

The Japanese siting approach for a HLW repository calls for volunteer host municipalities and thereby places particular emphasis on design flexibility. In particular, the repository concept needs to be tailored to the specific site characteristics. Starting from the H12 repository concept, NUMO has been examining a range of possible repository design options, including the EBS. In this paper. the requirements and strategy for the development of models for performance assessment and process understanding are discussed, taking into account the step-wise, iterative process of developing repository concepts. The areas requiring further development of models and databases in the long-term R and D programme have been identified as a 'wish list' that relates to the evaluation of a range of potential repository concepts, focusing on the near-field for the early stages of the development process. Among the issues on the list, NUMO has started the development of a flexible computer code for modelling three-dimensional mass transport to evaluate the impacts of various design options and components of the EBS. This tool has been applied to the analysis of the barrier effects of the tunnel plugs located in fractured rock. (authors)

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

Directory of Open Access Journals (Sweden)

Stoulil J.

2016-06-01

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

International high-level radioactive waste repositories

International Nuclear Information System (INIS)

Lin, W.

1996-01-01

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

Waste-rock interactions in the immediate repository

International Nuclear Information System (INIS)

McCarthy, G.J.

1977-01-01

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

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

Science.gov (United States)

2010-02-25

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

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

Energy Technology Data Exchange (ETDEWEB)

Ross, B. (ed.)

1989-02-01

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

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

International Nuclear Information System (INIS)

Ross, B.

1989-02-01

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

Training courses on integrated safety assessment modelling for waste repositories

International Nuclear Information System (INIS)

Mallants, D.

2007-01-01

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

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

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

International Nuclear Information System (INIS)

Saidumarov, P.

2000-01-01

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

Expected brine movement at potential nuclear waste repository salt sites

International Nuclear Information System (INIS)

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

1987-08-01

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

Influence of Groundwater Flow Rate on Nuclide Releases from Pyro-processed Waste Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2011-01-01

Since the early 2000s several template programs for the safety assessment of a high-level radioactive waste repository as well as a low- and intermediate level radioactive waste repository systems have been developed by utilizing GoldSim and AMBER at KAERI. Very recently, another template program for a conceptual hybrid-typed repository system, called 'A-KRS' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from pyroprocessing of PWR nuclear spent fuels has been developed and are to be disposed of by separate disposal strategies. The A-KRS is considered to be constructed at two different depths in geological media: 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and 500m depth, believed to be in the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of waste package and canister. To quantify a nuclide release and transport through the possible various pathways especially in the near-fields of the A-KRS repository system, some illustrative evaluations have been made through the study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

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

International Nuclear Information System (INIS)

Eriksson, L.G.

2000-01-01

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

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

International Nuclear Information System (INIS)

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

1995-01-01

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

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

International Nuclear Information System (INIS)

Mendel, J.E.

1982-10-01

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

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

Thermal Management and Analysis for a Potential Yucca Mountain Repository

International Nuclear Information System (INIS)

Dr. A. Van Luik

2004-01-01

In the current Yucca Mountain repository design concept, heat from the emplaced waste (mostly from spent nuclear fuel) would keep the temperature of the rock around the waste packages higher than the boiling point of water for hundreds to thousands of years after the repository is closed. The design concept allows below-boiling portions of the pillars between drifts to serve as pathways for the drainage of thermally mobilized water and percolating groundwater by limiting the distance that boiling temperatures extend into the surrounding rock. This design concept takes advantage of host rock dry out, which would create a dry environment within the emplacement drifts and reduce the amount of water that might otherwise be available to enter the drifts and contact the waste packages during this thermal pulse. Table 1 provides an overview of design constraints related to thermal management after repository closure. The Yucca Mountain repository design concept also provides flexibility to allow for operation over a range of lower thermal operating conditions. The thermal conditions within the emplacement drifts can be varied, along with the relative humidity, by modifying operational parameters such as the thermal output of the waste packages, the spacing of the waste packages in the emplacement drifts, and the duration and rate of active and passive ventilation. A lower range has been examined to quantify lower-temperature thermal conditions (temperatures and associated humidity conditions) in the emplacement drifts and to quantify impacts to the required emplacement area and excavated drift length. This information has been used to evaluate the potential long-term performance of a lower-temperature repository and to estimate the increase in costs associated with operating a lower-temperature repository. This presentation provides an overview of the thermal management evaluations that have been conducted to investigate a range of repository thermal conditions and

Thermal Analysis of a Nuclear Waste Repository in Argillite Host Rock

Science.gov (United States)

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

2017-12-01

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

Development of a central final repository management for the coordination of the waste for Schacht Konrad from public authorities; Aufbau des zentralen Endlagerungsmanagements fuer die Koordination der Konrad-Abfaelle aus der oeffentlichen Hand

Energy Technology Data Exchange (ETDEWEB)

Graffunder, Iris; Dominke-Bendix, Carola; Waldek, Achim [Energiewerke Nord GmbH (EWN), Eggenstein-Leopoldshafen (Germany). Betriebsstaette Karlsruhe; Wunn, Christoph [admoVa Consulting GmbH, Bad Camberg (Germany)

2012-11-01

The central final repository management is supposed to fulfill the following tasks: active collaboration of Konrad contract draft, signing of internal contracts and agreements, cooperation contract with GNS, cooperation with coordination authorities, inventory taking of wastes (existing inventory and prognosis) and interim storage capacities of public authorities, development of planning and management software, optimization of the final repository documentation, container management, logistics concept, long-term disposal planning and prognosis, planning and coordination of the annual waste amount, management and documentation of disposed waste allocation, coordination of transport schedules, consulting service for waste obligations (final repository requirements, product control, documentation).

Thermal, operational, and economic aspects of repository design alternatives

International Nuclear Information System (INIS)

Closs, K.D.; Papp, R.; Bechthold, W.; Engelmann, H.J.; Hartje, B.

1989-01-01

This paper discusses how a broad spectrum of heat-generating nuclear waste types like reprocessing waste (HLW, ILW), spent LWR, and spent HTR fuel will be disposed of in a future German repository located in a salt dome. Different package and emplacement concepts for the various waste forms are feasible, ranging from pure borehole emplacement of canisters and drums to pure drift emplacement of heavily shielded casks as well as combinations of both concepts. Optimization of the whole back-end system (waste treatment, interim storage, and disposal) is performed taking into account thermal, operational, and economic aspects. From a radiological viewpoint, the drift emplacement concept is superior to all concepts in as much as the occupational dose is lowest and zero release from the casks is attainable during normal and anomalous repository operation. As far as economics are concerned, the cost of the heavily shielded casks necessary for drift emplacement contributes markedly to the overall cost of the whole back-end system. Drift emplacement can compete economically with the other concepts only if the casks are used both for interim storage and disposal

NWTS conceptual reference repository description (CRRD). Volume 1. Summary

International Nuclear Information System (INIS)

1981-05-01

This report is a Conceptual Reference Repository Description (CRRD) for the terminal storage of spent, unreprocessed fuel assemblies and low-level transuranic waste. It is based on the following three previously prepared conceptual design reports: National Waste Terminal Storage in a Bedded Salt Formation for Spent Unreprocessed Fuel (NWTS-R2), prepared by Kaiser Engineers; National Waste Terminal Storage Repository Number 1 (NWTS-R1), prepared by Stearns-Roger; Spent Fuel Receiving and Packaging Facility Conceptual Design, prepared by Rockwell Hanford Operations and Kaiser Engineers. The CRRD is not itself a conceptual design report, but combines the key features of the above three reports into a description of a reference repository. This description is to be used as a basis for the preparation of a preliminary information report for the repositories. The CRRD discusses from a conceptual engineering standpoint the structures, systems, equipment, and operations necessary to (1) receive unreprocessed spent fuel assemblies via standard shipping casks, (2) offload these assemblies, (3) place the assemblies in canisters, (4) transport the canisters to underground storage locations in the salt dome, and (5) place these canisters in terminal storage. The CRRD also elaborates on the concepts for the retrieval and recovery of the spent fuel after burial; describes the development of the shafts and the underground areas,as well as the supporting operational utility and administrative features of the repository; and discusses the impacts on the reference repository of (1) changes in the waste package concept, (2) dry receiving and dry temporary storage of waste, (3) terminal storage of reprocessing waste, and (4) alternative underground development schemes

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

Nuclear waste repository research at the micro- to nanoscale

Science.gov (United States)

Schäfer, T.; Denecke, M. A.

2010-04-01

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

The disposal of orphan wastes using the greater confinement disposal concept

International Nuclear Information System (INIS)

Bonano, E.J.; Chu, M.S.Y.; Price, L.L.; Conrad, S.H.; Dickman, P.T.

1991-01-01

In the United States, radioactive wastes are conventionally classified as high-level wastes, transuranic wastes, or low-level wastes. Each of these types of wastes, by law, has a ''home'' for their final disposal; i.e., high-level wastes are destined for disposal at the proposed repository at Yucca Mountain, transuranic waste for the proposed Waste Isolation Pilot Plant, and low-level waste for shallow-land disposal sites. However, there are some radioactive wastes within the United States Department of Energy (DOE) complex that do not meet the criteria established for disposal of either high-level waste, transuranic waste, or low-level waste. The former are called ''special-case'' or ''orphan'' wastes. This paper describes an ongoing project sponsored by the DOE's Nevada Operations Office for the disposal of orphan wastes at the Radioactive Waste Management Site at Area 5 of the Nevada Test Site using the greater confinement disposal (GCD) concept. The objectives of the GCD project are to evaluate the safety of the site for disposal of orphan wastes by assessing compliance with pertinent regulations through performance assessment, and to examine the feasibility of this disposal concept as a cost-effective, safe alternative for management of orphan wastes within the DOE complex. Decisions on the use of GCD or other alternate disposal concepts for orphan wastes be expected to be addressed in a Programmatic Environmental Impact Statement being prepared by DOE. The ultimate decision to use GCD will require a Record of Decision through the National Environmental Policy Act (NEPA) process. 20 refs., 3 figs., 2 tabs

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Preliminary waste acceptance requirements for the planned Konrad repository

International Nuclear Information System (INIS)

Warnecke, E.; Brennecke, P.

1987-01-01

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

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

International Nuclear Information System (INIS)

Dennis, A.W.; Mulkin, R.

1984-01-01

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

A Probabilistic Safety Assessment of a Pyro-processed Waste Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2012-01-01

A GoldSim template program for a safety assessment of a hybrid-typed repository system, called A-KRS, in which two kinds of pyro-processed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyro-processing of PWR nuclear spent fuels are disposed of, has been developed. This program is ready both for a deterministic and probabilistic total system performance assessment which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios. The A-KRS has been probabilistically assessed with 9 selected input parameters, each of which has its own statistical distribution for a normal release and transport scenario associated with nuclide release and transport in and around the repository. Probabilistic dose exposure rates to the farming exposure group have been evaluated. A sensitivity of 9 selected parameters to the result has also been investigated to see which parameter is more sensitive and important to the exposure rates.

Constructibility issues associated with a nuclear waste repository in basalt

International Nuclear Information System (INIS)

Turner, D.A.

1981-01-01

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

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

Natural geochemical analogues of the near field of high-level nuclear waste repositories

International Nuclear Information System (INIS)

Apps, J.A.

1995-01-01

United States practice has been to design high-level nuclear waste (HLW) geological repositories with waste densities sufficiently high that repository temperatures surrounding the waste will exceed 100 degrees C and could reach 250 degrees C. Basalt and devitrified vitroclastic tuff are among the host rocks considered for waste emplacement. Near-field repository thermal behavior and chemical alteration in such rocks is expected to be similar to that observed in many geothermal systems. Therefore, the predictive modeling required for performance assessment studies of the near field could be validated and calibrated using geothermal systems as natural analogues. Examples are given which demonstrate the need for refinement of the thermodynamic databases used in geochemical modeling of near-field natural analogues and the extent to which present models can predict conditions in geothermal fields

Geochemical modeling of the nuclear-waste repository system. A status report

International Nuclear Information System (INIS)

Deutsch, W.J.

1980-12-01

The primary objective of the geochemical modeling task is to develop an understanding of the waste-repository geochemical system and provide a valuable tool for estimating future states of that system. There currently exists a variety of computer codes which can be used in geochemical modeling studies. Some available codes contain the framework for simulating a natural chemical system and estimating, within limits, the response of that system to environmental changes. By data-base enhancement and code development, this modeling technique can be even more usefully applied to a nuclear-waste repository. In particular, thermodynamic data on elements not presently in the data base but identified as being of particular hazard in the waste-repository system, need to be incorporated into the code to estimate the near-field as well as the far-field reactions during a hypothetical breach. A reaction-path-simulation code, which estimates the products of specific rock/water reactions, has been tested using basalt and ground water. Results show that the mass-transfer capabilities of the code will be useful in chemical-evolution studies and scenario analyses. The purpose of this report is to explain the status of geochemical modeling as it currently applies to the chemical system of a hypothetical nuclear-waste repository in basalt and to present the plan proposed for further developmet and application

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)

Alteration of national glass in radioactive waste repository host rocks: A conceptional review

International Nuclear Information System (INIS)

Apps, J.A.

1987-01-01

The storage of high-level radioactive wastes in host rocks containing natural glass has potential chemical advantages, especially if the initial waste temperatures are as high as 250 0 C. However, it is not certain how natural glasses will decompose when exposed to an aqueous phase in a repository environment. The hydration and devitrification of both rhyolitic and natural basaltic natural glasses are reviewed in the context of hypothetical thermodynamic phase relations, infrared spectroscopic data and laboratory studies of synthetic glasses exposed to steam. The findings are compared with field observations and laboratory studies of hydrating and devitrifying natural glasses. The peculiarities of the dependence of hydration and devitrification behavior on compositional variation is noted. There is substantial circumstantial evidence to support the belief that rhyolitic glasses differ from basaltic glasses in their thermodynamic stability and their lattice structure, and that this is manifested by a tendency of the former to hydrate rather than devitrify when exposed to water. Further research remains to be done to confirm the differences in glass structure, and to determine both physically and chemically dependent properties of natural glasses as a function of composition

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

International Nuclear Information System (INIS)

2001-12-01

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

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)

Project Guarantee 1985. Final repository for high-level radioactive wastes: The system of safety barriers

International Nuclear Information System (INIS)

Anon.

1985-01-01

Final disposal of radioactive waste involves preventing the waste from returning from the repository location into the biosphere by means of successively arranged containment measures known as safety barriers. In the present volume NGB 85-04 of the series of reports for Project 'Guarantee' 1985, the safety barrier system for the type C repository for high-level waste is described. The barrier parameters which are relevant for safety analysis are quantified and associated error limits and data scatter are given. The aim of the report is to give a summary documentation of the safety analysis input data and their scientific background. For secure containment of radioactive waste safety barriers are used which effectively limit the release of radioactive material from the repository (release barriers) and effectively retard the entry of the original radioactive material into the biosphere (time barriers). Safety barriers take the form of both technically constructed containment measures and the siting of the repository in suitable geological formations. The technical safety barrier system in the case of high-level waste comprises: the waste solidification matrix (borosilicate glass), massive steel canisters, encasement of the waste canisters, encasement of the waste canisters in highly compacted bentonite, sealing of vacant storage space and access routes on repository closure. The natural geological safety barriers - the host rock and overlying formations provide sufficiently long deep groundwater flow times from the repository location to the earth's surface and for additional lengthening of radionuclide migration times by means of various chemical and physical retardation mechanisms. The stability of the geological formations is so great that hydrogeological system is protected for a sufficient length of time from deterioration caused, in particular, by erosion. Observations in the final section of the report indicate that input data for the type C repository safety

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

Directory of Open Access Journals (Sweden)

Yifeng Wang

2013-12-01

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

Preliminary safety analysis of the Baita Bihor radioactive waste repository, Romania

International Nuclear Information System (INIS)

Little, Richard; Bond, Alex; Watson, Sarah; Dragolici, Felicia; Matyasi, Ludovic; Matyasi, Sandor; Naum, Mihaela; Niculae, Ortenzia; Thorne, Mike

2007-01-01

A project funded under the European Commission's Phare Programme 2002 has undertaken an in-depth analysis of the operational and post-closure safety of the Baita Bihor repository. The repository has accepted low- and some intermediate-level radioactive waste from industry, medical establishments and research activities since 1985 and the current estimate is that disposals might continue for around another 20 to 35 years. The analysis of the operational and post-closure safety of the Baita Bihor repository was carried out in two iterations, with the second iteration resulting in reduced uncertainties, largely as a result taking into account new information on the hydrology and hydrogeology of the area, collected as part of the project. Impacts were evaluated for the maximum potential inventory that might be available for disposal to Baita Bihor for a number of operational and postclosure scenarios and associated conceptual models. The results showed that calculated impacts were below the relevant regulatory criteria. In light of the assessment, a number of recommendations relating to repository operation, optimisation of repository engineering and waste disposals, and environmental monitoring were made. (authors)

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

Performance Assessments of Generic Nuclear Waste Repositories in Shale

Science.gov (United States)

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

2017-12-01

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

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

International Nuclear Information System (INIS)

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

2010-01-01

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

Further design work on a repository in a salt dome

International Nuclear Information System (INIS)

Hamstra, J.; Janssen, L.G.L.

1985-01-01

The report presents the cost estimate and the work plan for the construction of a repository, to be mined in a medium-size salt dome for the simultaneous disposal of different categories of solid radioactive wastes. The repository is designed for all categories of waste from 40 years of operation of 25 nuclear power stations of 1000 MWe each, including the decommissioning waste from these stations as well as all the radioactive wastes from the hospitals and laboratories during a hundred-year period. The cost estimate includes preparation of a site, the construction, operation and abandonment of that repository. Moreover, an outline has been presented for a future updating and optimization study of the concept

Status of work on the final repository concept concerning direct disposal of spent fuel rods in fuel rod casks (BSK)

International Nuclear Information System (INIS)

Filbert, W.; Wehrmann, J.; Bollingerfehr, W.; Graf, R.; Fopp, S.

2008-01-01

The reference concept in Germany on direct final storage of spent fuel rods is the burial of POLLUX containers in the final repository salt dome. The POLLUX container is self-shielded. The final storage concept also includes un-shielded borehole storage of high-level waste and packages of compacted waste. GNS has developed a spent fuel container (BSK-3) for unshielded borehole storage with a mass of 5.2 tons that can carry the fuel rods of three PWR reactors of 9 BWR reactors. The advantages of BSK storage include space saving, faster storage processes, less requirements concerning technical barriers, cost savings for self-shielded casks.

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

International Nuclear Information System (INIS)

Murauskas, G.T.

1989-01-01

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

The procedure of alternative site selection within the report of the study group on the radioactive waste final repository selection process (AKEnd)

International Nuclear Information System (INIS)

Brenner, M.

2005-01-01

The paper discusses the results of the report of the study group on the radioactive waste final repository selection process with respect to the alternative site selection procedure. Key points of the report are the long-term safety, the alternativity of sites and the concept of one repository. The critique on this report is focussed on the topics site selection and licensing procedures, civil participation, the factor time and the question of cost

Understanding large scale groundwater flow to aid in repository siting

International Nuclear Information System (INIS)

Davison, C.C.; Brown, A.; Gascoyne, M.; Stevenson, D.R.; Ophori, D.U.

1996-01-01

Atomic Energy of Canada Limited (AECL) with support from Ontario Hydro has developed a concept for the safe disposal of Canada's nuclear fuel waste in a deep (500 to 1000 m) mined repository in plutonic rocks of the Canadian Shield. The disposal concept involves the use of multiple engineered and natural barriers to ensure long-term safety. The geosphere, comprised of the enclosing rock mass and the groundwater which occurs in cracks and pores in the rock, is expected to serve as an important natural barrier to the release and migration of wastes from the engineered repository. Although knowledge of the physical and chemical characteristics of the groundwater in the rock at potential repository sites is needed to help design the engineered barriers of the repository it can also be used to aid in repository siting, to take greater advantage of natural conditions in the geosphere to enhance its role as a barrier in the overall disposal system

LIFE Materials: Fuel Cycle and Repository Volume 11

Energy Technology Data Exchange (ETDEWEB)

Shaw, H; Blink, J A

2008-12-12

The fusion-fission LIFE engine concept provides a path to a sustainable energy future based on safe, carbon-free nuclear power with minimal nuclear waste. The LIFE design ultimately offers many advantages over current and proposed nuclear energy technologies, and could well lead to a true worldwide nuclear energy renaissance. When compared with existing and other proposed future nuclear reactor designs, the LIFE engine exceeds alternatives in the most important measures of proliferation resistance and waste minimization. The engine needs no refueling during its lifetime. It requires no removal of fuel or fissile material generated in the LIFE engine. It leaves no weapons-attractive material at the end of life. Although there is certainly a need for additional work, all indications are that the 'back end' of the fuel cycle does not to raise any 'showstopper' issues for LIFE. Indeed, the LIFE concept has numerous benefits: (1) Per unit of electricity generated, LIFE engines would generate 20-30 times less waste (in terms of mass of heavy metal) requiring disposal in a HLW repository than does the current once-through fuel cycle. (2) Although there may be advanced fuel cycles that can compete with LIFE's low mass flow of heavy metal, all such systems require reprocessing, with attendant proliferation concerns; LIFE engines can do this without enrichment or reprocessing. Moreover, none of the advanced fuel cycles can match the low transuranic content of LIFE waste. (3) The specific thermal power of LIFE waste is initially higher than that of spent LWR fuel. Nevertheless, this higher thermal load can be managed using appropriate engineering features during an interim storage period, and could be accommodated in a Yucca-Mountain-like repository by appropriate 'staging' of the emplacement of waste packages during the operational period of the repository. The planned ventilation rates for Yucca Mountain would be sufficient for LIFE waste

LIFE Materials: Fuel Cycle and Repository Volume 11

International Nuclear Information System (INIS)

Shaw, H.; Blink, J.A.

2008-01-01

The fusion-fission LIFE engine concept provides a path to a sustainable energy future based on safe, carbon-free nuclear power with minimal nuclear waste. The LIFE design ultimately offers many advantages over current and proposed nuclear energy technologies, and could well lead to a true worldwide nuclear energy renaissance. When compared with existing and other proposed future nuclear reactor designs, the LIFE engine exceeds alternatives in the most important measures of proliferation resistance and waste minimization. The engine needs no refueling during its lifetime. It requires no removal of fuel or fissile material generated in the LIFE engine. It leaves no weapons-attractive material at the end of life. Although there is certainly a need for additional work, all indications are that the 'back end' of the fuel cycle does not to raise any 'showstopper' issues for LIFE. Indeed, the LIFE concept has numerous benefits: (1) Per unit of electricity generated, LIFE engines would generate 20-30 times less waste (in terms of mass of heavy metal) requiring disposal in a HLW repository than does the current once-through fuel cycle. (2) Although there may be advanced fuel cycles that can compete with LIFE's low mass flow of heavy metal, all such systems require reprocessing, with attendant proliferation concerns; LIFE engines can do this without enrichment or reprocessing. Moreover, none of the advanced fuel cycles can match the low transuranic content of LIFE waste. (3) The specific thermal power of LIFE waste is initially higher than that of spent LWR fuel. Nevertheless, this higher thermal load can be managed using appropriate engineering features during an interim storage period, and could be accommodated in a Yucca-Mountain-like repository by appropriate 'staging' of the emplacement of waste packages during the operational period of the repository. The planned ventilation rates for Yucca Mountain would be sufficient for LIFE waste to meet the thermal constraints of

Implementation of technical conservatism in the development of nuclear waste repositories

International Nuclear Information System (INIS)

1981-03-01

The Department of Energy (DOE) waste management program is committed to assuring the safe disposal of radioactive waste. It is recognized that long-term disposal concepts will contain inherent uncertainties in predictive techniques and scientific information. Accordingly, conservative approaches ae being followed to enhance levels of confidence that the disposal system will perform in such a manner that the established performance requirements will be met. Limiting values of critical parameters will be established for each site based on its inherent characteristics prior to beginning site development. The performance limits will be established for each geometric region of the repository system and be applied simultaneously to assure that no single limit is violated over the repository life cycle. A site-specific set of specifications will be determined when the site is fully characterized, establishing a conservative design basis to increase confidence in safe system performance. The implementation of the NWTS program policy on technical conservatism, as discussed in this document, takes two forms--(1) conservatism in the conduct of the program and (2) conservatism in the performance of the disposal system. The first is achieved by a stepwise approach to system development and operation, the systems viewpoint, the retrievability requirement, and the extensive use of peer reviews throughout the conduct of the program. The second is achieved by the proper selection and application of conservative design and operational limits

Thermal management and analysis for a potential yucca mountain repository

International Nuclear Information System (INIS)

Van Luik, A.

2005-01-01

In the current Yucca Mountain repository design concept, heat from the emplaced. waste (mostly from spent nuclear fuel.) would keep the temperature of the rock around the waste packages higher than the boiling point of water for hundreds to thousands of years after the repository is closed. The design concept allows below-boiling portions of the pillars between drifts to serve as pathways for the drainage of thermally mobilized water and percolating groundwater by limiting the distance that boiling temperatures extend into the surrounding rock. This design concept takes advantage of host rock dry out, which would create a dry environment within the emplacement drifts and reduce the amount of water that might otherwise be available to enter the drifts and contact the waste packages during this thermal pulse. The Yucca Mountain repository design concept also provides flexibility to allow for operation over a range of lower thermal operating conditions. The thermal conditions within the emplacement drifts can be varied, along with the relative humidity, by modifying operational parameters such as the thermal output of the waste packages, the spacing of the waste packages in the emplacement drifts, and. the duration and rate of active and passive ventilation. A lower range has been examined to quantify lower-temperature thermal conditions (temperatures and associated humidity conditions) in the emplacement drifts and to quantify impacts to the required emplacement area and excavated drift length. This information has been used to evaluate the potential long-term performance of a lower-temperature repository and to estimate the increase in costs associated with operating a lower-temperature repository. This presentation provides an overview of the thermal management evaluations that have been conducted to investigate a range of repository thermal conditions and includes a summary of the technical basis that supports these evaluations. The majority of the material

Shaft seals for final high-level radioactive waste repositories. ELSA. Pt. 1

International Nuclear Information System (INIS)

Kudla, W.; Schreiter, F.; Gruner, M.

2013-01-01

The state of the art in science and technology fir shaft seals with long-term stability is summarized regarding their applicability for high-level waste repository in Germany. The concepts and drafts for the shaft sealing systems ERAM, Asse, Konrad, the WIPP side, the RESEAL concept, the NAGRA concept and the project LASA are reviewed. The methodology of applying partial factors in a safety analysis is summarized and the applicability of this method for geotechnical sealing structures is confirmed. To establish geomechanical boundary conditions of the host rocks and clay stone the stress-strain behavior of the rock mass adjoining the shaft has to be identified including time-dependent thermo-mechanical processes. The general and special requirements for the design of shaft sealing systems, especially in salt rock and clay formations are described, derived from the safety requirements (BMU 2010). Finally general information needs were identified.

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.''

500 year concrete for a radioactive waste repository

International Nuclear Information System (INIS)

Philipose, K.E.

1988-03-01

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

Method for screening the Nevada Test Site and contiguous areas for nuclear waste repository locations

International Nuclear Information System (INIS)

Sinnock, S.; Fernandez, J.A.; Neal, J.T.; Stephens, H.P.; Hartway, B.L.; Los Alamos Technical Associates, Inc., NM)

1982-01-01

This paper outlines the general concepts of a technical method for systematic screening of the Nevada Test Site (NTS), Nye County, Nevada, for potentially suitable nuclear waste repository locations. After a general discussion of the organization and the purpose of the current screening activity, the paper addresses the steps of the screening method. These steps include: hierarchically organizing technical objectives for repository performance (an objectives tree); identifying and mapping pertinent physical characteristics of a site and its setting (physical attributes); relating the physical conditions to the objectives (favorability curves); identifying alternative locations and numerically evaluating their relative merits; investigating the effects of subjective judgments on the evaluations (sensitivity analyses); documenting the assumptions, logic, and results of the method. 19 references, 10 figures

Decision-Making Risks Concerning the Construction of the Goiania Waste Repository

International Nuclear Information System (INIS)

Paschoa, A.S.; Rozental, J.J.; Tranjan Filho, A.

2001-01-01

As it is well known, an accident with a teletherapy source made of 137 CsCl with an initial activity of 59 TBq occurred in Goiania, in September of 1987. This paper will discuss the decision-making process, and the struggle that followed the decision to build the final repository for the remnants of the Goiania accident. The Goiania final repository was built as planned. The two subsurface structures under the grassy artificial hills hold the overall volume of the remnants of the Goiania accident. The near hill holds 5x10 3 m3 of stabilized wastes without radioactivity, or with very low radioactivity. The far hill holds the remaining 6.5x10 3 m 3 of stabilized wastes with low and medium radioactivity. The central part of each subsurface hill has been shielded by wastes with less and less radioactivity. The overall fenced area occupies 1.85x10 5 m 2 . The external radiation levels are similar to the surrounding background, and much lower than those found in the Brazilian areas of high natural radioactivity. The site is permanently monitored by independent institutions, including Brazilian universities, and national and international organizations. As it was mentioned earlier, the final repository was build to last for at least 400 years. Although the initial decision to adopt a too conservative decontamination criterion in the case of the Goiania accident was bound to produce excessive amount of waste; such decision proved, retrospectively, not to be bad because the excess low radioactive waste produced was used as extra shielding material in final repository. The technical decision-maker should not abandon risk estimates, but should be aware that credibility is the main basis to achieve acceptability of a decision by the general public. Risk perception should be regarded as only a first step towards what may be called knowledge, or comprehension of risk estimates, but risk perception by the general public is still an open issue. The problem of a fixed, or near

Geological Disposal of Radioactive Waste: Technological Implications for Retrievability

International Nuclear Information System (INIS)

2009-01-01

Various IAEA Member States are discussing whether and to what degree reversibility (including retrievability) might be built into management strategies for radioactive waste. This is particularly the case in relation to the disposal of long lived and/or high level waste and spent nuclear fuel (SNF) in geological repositories. It is generally accepted that such repositories should be designed to be passively safe with no intention of retrieving the waste. Nevertheless, various reasons have been advanced for including the concept of reversibility and the ability to retrieve the emplaced wastes in the disposal strategy. The intention is to increase the level of flexibility and to provide the ability to cope with, or to benefit from, new technical advances in waste management and materials technologies, and to respond to changing social, economic and political opinion. The technological implications of retrievability in geological disposal concepts are explored in this report. Scenarios for retrieving emplaced waste packages are considered and the report aims to identify and describe any related technological provisions that should be incorporated into the design, construction, operational and closure phases of the repository. This is based on a number of reference concepts for the geological disposal of radioactive waste (including SNF) which are currently being developed in Member States with advanced development programmes. The report begins with a brief overview of various repository concepts, starting with a summary of the types of radioactive waste that are typically considered for deep geological disposal. The main host rocks considered are igneous crystalline and volcanic rocks, argillaceous clay rocks and salts. The typical design features of repositories are provided with a description of repository layouts, an overview of the key features of the major repository components, comprising the waste package, the emplacement cells and repository access facilities

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

International Nuclear Information System (INIS)

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

2010-01-01

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

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

International Nuclear Information System (INIS)

Ebel, K.; Richter, D.

1988-01-01

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

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

International Nuclear Information System (INIS)

Berner, Urs

1999-12-01

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

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

International Nuclear Information System (INIS)

Schmidt, B.

1988-01-01

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

Nuclide release calculation in the near-field of a reference HLW repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Hwang, Yong Soo; Kang, Chul Hyung

2004-01-01

The HLW-relevant R and D program for disposal of high-level radioactive waste has been carried out at Korea Atomic Energy Research Institute (KAERI) since early 1997 in order to develop a conceptual Korea Reference Repository System for direct disposal of nuclear spent fuel by the end of 2007. A preliminary reference geologic repository concept considering such established criteria and requirements as waste and generic site characteristics in Korea was roughly envisaged in 2003 focusing on the near-field components of the repository system. According to above basic repository concept, which is similar to that of Swedish KBS-3 repository, the spent fuel is first encapsulated in corrosion resistant canisters, even though the material has not yet been determined, and then emplaced into the deposition holes surrounded by high density bentonite clay in tunnels constructed at a depth of about 500 m in a stable plutonic rock body. Not only to demonstrate how much a reference repository is safe in the generic point of view with several possible scenarios and cases associated with a preliminary repository concept by conducting calculations for nuclide release and transport in the near-field components of the repository, even though enough information has not been available that much yet, but also to show a methodology by which a generic safety assessment could be performed for further development of Korea reference repository concept, nuclide release calculation study strongly seems to be necessary

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

International Nuclear Information System (INIS)

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

1997-01-01

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

Hydrological and thermal issues concerning a nuclear waste repository in fractured rocks

International Nuclear Information System (INIS)

Wang, J.S.Y.

1991-12-01

The characterization of the ambient conditions of a potential site and the assessment of the perturbations induced by a nuclear waste repository require hydrological and thermal investigations of the geological formations at different spatial and temporal scales. For high-level wastes, the near-field impacts depend on the heat power of waste packages and the far-field long-term perturbations depend on the cumulative heat released by the emplaced wastes. Surface interim storage of wastes for several decades could lower the near-field impacts but would have relatively small long-term effects if spent fuels were the waste forms for the repository. One major uncertainty in the assessment of repository impacts is from the variation of hydrological properties in heterogeneous media, including the effects of fractures as high-permeability flow paths for containment migration. Under stress, a natural fracture cannot be represented by the parallel plate model. The rock surface roughness, the contact area, and the saturation state in the rock matrix could significantly change the fracture flow. In recent years, the concern of fast flow through fractures in saturated media has extended to the unsaturated zones. The interactions at different scales between fractures and matrix, between fractured matrix unites and porous units, and between formations and faults are discussed

Modelling of the degradation of cement in a nuclear waste repository

International Nuclear Information System (INIS)

Haworth, A.; Sharland, S.M.; Tweed, C.J.

1989-01-01

The current UK concept for a low- or intermediate-level nuclear waste repository includes a largely cementitious backfill. The cement provides a high pH environment in which the general corrosion rate of the metal canisters is reduced and the solubilities of many nuclides low. It has previously been assumed that this high pH will exist for a period of 10 7 years, however cement will degrade due to leaching of the solid components and attack from aqueous species in groundwater. In this paper the authors describe the preliminary stages of a model of the degradation of cement in a repository. The modelling involves the incorporation of a thermodynamic description of cement into the static code PHREEQE. This is then used in a coupled chemistry-transport model of simple leaching of cement using the code CHEQMATE. This preliminary modelling also provides a useful verification of CHEQMATE as a direct comparison with a THCCDM (a coupled code based on CHEMTRN) model is possible. Results from this preliminary model suggest that the fall in pH due to leaching is slow

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.

Requirements of actual final repository concepts for different host rock formations. Final report; Anforderungen an aktuelle Endlagerkonzepte fuer unterschiedliche Wirtsgesteinsformationen. Abschlussbericht

Energy Technology Data Exchange (ETDEWEB)

Fass, Thorsten; Hartwig-Thurat, Eva; Krischer, Angelika; Lambers, Ludger; Larue, Juergen; Uhlmann, Stephan; Weyand, Torben

2017-08-15

In the frame of the research project the basic requirements and technical safety specifications with respect to the retrievability of stored radioactive wastes for the different final repository concepts based on the host rock formations occurring in Germany are presented. Existing international disposal concepts for clay/claystone, granite and salt are described and compared to the actual German regulatory requirements. The safety engineering relations between stock piling and possible retrieval are described and evaluated.

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

Energy Technology Data Exchange (ETDEWEB)

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

2009-06-15

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

Waste repository planned for Bruce Site

International Nuclear Information System (INIS)

King, F.

2004-01-01

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

Law no. 10.308 of 20th November, 2001 on radioactive waste repositories siting, construction, licensing, operation, inspection, costs, indemnity, civil liability and guarantees concerning to the radioactive wastes repositories and other provisions

International Nuclear Information System (INIS)

2001-01-01

This Act was published on November 20, 2001 and set forth regulations on the final disposal of radioactive wastes produced in Brazil, including siting, construction, licensing, operation, inspection, costs, indemnities, civil liability and guarantees concerning to the radioactive wastes repositories. This act allows for installation and operation of initial, intermediary and final repositories in accordance with the criteria established by the Brazilian Nuclear Energy National Commission - CNEN. The person or organization granted with CNEN authorization for operation of the initial repositories shall be liable for personal, patrimony and environmental radiological damages. The civil liability of CNEN is concerned to the radioactive waste intermediary and final disposals and transportation

Is Croatia Going to Build a Radioactive Waste Repository?

International Nuclear Information System (INIS)

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

2014-01-01

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

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

International Nuclear Information System (INIS)

Perkins, C.

2001-01-01

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

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

International Nuclear Information System (INIS)

Cook, N.G.W.

1978-01-01

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

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

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

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.

Shale as a radioactive waste repository: the importance of vermiculite

Energy Technology Data Exchange (ETDEWEB)

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

1979-01-01

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

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

Energy Technology Data Exchange (ETDEWEB)

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

1999-03-15

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

Salt Repository Project waste emplacement mode decision paper: Revison 1

International Nuclear Information System (INIS)

1987-08-01

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

Radioactive waste repositories in hard rock aquifers--hydrodynamic aspects

International Nuclear Information System (INIS)

Thunvik, R.; Braester, C.

1984-01-01

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

Considerations for reduction of gas generation in a low-level radioactive waste repository

International Nuclear Information System (INIS)

Cho, Chan Hee; Son, Jung Kwon; Lee, Myung Chan; Song, Myung Jae

1997-01-01

In a low-level radioactive waste repository, H 2 , CO 2 , and CH 4 will be generated principally by the coupled processes of metal corrosion and microbial degradation of cellulosic waste. The metal corrosion model incorporates a three-stage process encompassing aerobic and anaerobic corrosion regimes; the microbial degradation model simulates the activities of eight different microbial populations, which are maintained as functions both of pH and of the concentrations of particular chemical species. A prediction is made for gas concentrations and generation rates over an assessment period of ten thousand years in a radioactive waste repository. The results suggest that H 2 is the principal gas generated within the radioactive waste cavern. The generation rates of CO 2 and CH 4 are likely to be insignificant by comparison with H 2 . Therefore, an effective way to decrease gas generation in a radioactive waste repository seems to be to reduce metal content since the generation rate of H 2 is most sensitive to the concentration of steel

Nuclear waste repository in basalt: a design description

International Nuclear Information System (INIS)

Ritchie, J.S.; Schmidt, B.

1982-01-01

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

Testing of high-level waste forms under repository conditions

International Nuclear Information System (INIS)

Mc Menamin, T.

1989-01-01

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

Material control and accountability procedures for a waste isolation repository

International Nuclear Information System (INIS)

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

1978-05-01

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

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

International Nuclear Information System (INIS)

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

1985-01-01

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

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

Characteristics of potential repository wastes

International Nuclear Information System (INIS)

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

1992-10-01

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

Disruption scenarios for a high-level waste repository at Yucca Mountain, Nevada

International Nuclear Information System (INIS)

Ross, B.

1986-01-01

A high-level waste repository located in unsaturated welded tuff at Yucca Mountain, Nevada, would rely on six different, although not entirely independent, barriers to prevent escape of radioactivity. These barriers are the waste canister, fuel cladding, slow dissolution of the spent fuel itself, and slow movement of released contaminants in three different hydrogeologic units: the unsaturated Topopah Spring welded tuff unit, the unsaturated Calico Hills nonwelded tuff unit, and the saturated tuff aquifer. Fifty-eight processes and events that might affect such a repository were reviewed. Eighty-three different sequences were identified by which these processes and events could lead to failure of one or more barriers. Sequences which had similar consequences were grouped, yielding 17 categories. The repository system has considerable redundancy; most of the more likely disruptions affect only one or a few barriers. Occurrence of more than one disruption is needed before such disruptions would cause release of radioactivity. Future studies of repository performance must assess the likelihood and consequences of multiple-disruption scenarios to evaluate how well the repository meets performance standards

Identification of key radionuclides in a nuclear waste repository in basalt

International Nuclear Information System (INIS)

Barney, G.S.; Wood, B.J.

1980-05-01

Radionuclides were identified which appear to pose the greatest potential hazard to man during long-term storage of nuclear waste in a repository mined in the Columbia Plateau basalt formation. The criteria used to select key radionuclides were as follows: quantity of radionuclide in stored waste; biological toxicity; leach rate of the wastes into groundwater; and transport rate via groundwater flow. The waste forms were assumed to be either unreprocessed spent fuel or borosilicate glass containing reprocessed high-level waste. The nuclear waste composition was assumed to be that from a light water reactor. Radionuclides were ranked according to quantity, toxicity, and release rate from the repository. These rankings were combined to obtain a single list of key radionuclides. The ten most important radionuclides in order of decreasing hazard are: 99 Tc, 129 I, 237 Np, 226 Ra, 107 Pd, 230 Th, 210 Pb, 126 Sn, 79 Se, and 242 Pu. Safety assessment studies and the design of engineered barriers should concentrate on containment of radionuclides in this list

SUBSURFACE REPOSITORY INTEGRATED CONTROL SYSTEM DESIGN

International Nuclear Information System (INIS)

Randle, D.C.

2000-01-01

The primary purpose of this document is to develop a preliminary high-level functional and physical control system architecture for the potential repository at Yucca Mountain. This document outlines an overall control system concept that encompasses and integrates the many diverse process and communication systems being developed for the subsurface repository design. This document presents integrated design concepts for monitoring and controlling the diverse set of subsurface operations. The Subsurface Repository Integrated Control System design will be composed of a series of diverse process systems and communication networks. The subsurface repository design contains many systems related to instrumentation and control (I andC) for both repository development and waste emplacement operations. These systems include waste emplacement, waste retrieval, ventilation, radiological and air monitoring, rail transportation, construction development, utility systems (electrical, lighting, water, compressed air, etc.), fire protection, backfill emplacement, and performance confirmation. Each of these systems involves some level of I andC and will typically be integrated over a data communications network throughout the subsurface facility. The subsurface I andC systems will also interface with multiple surface-based systems such as site operations, rail transportation, security and safeguards, and electrical/piped utilities. In addition to the I andC systems, the subsurface repository design also contains systems related to voice and video communications. The components for each of these systems will be distributed and linked over voice and video communication networks throughout the subsurface facility. The scope and primary objectives of this design analysis are to: (1) Identify preliminary system-level functions and interfaces (Section 6.2). (2) Examine the overall system complexity and determine how and on what levels the engineered process systems will be monitored

Decision-Making Risks Concerning the Construction of the Goiania Waste Repository

Energy Technology Data Exchange (ETDEWEB)

Paschoa, A.S. [Pontificia Univ. Catolica, Rio de Janeiro (Brazil); Rozental, J.J. [Ministry of Environment (Israel); Tranjan Filho, A. [Comissao Nacional de Energia Nuclear (CNEN) (Brazil)

2001-07-01

As it is well known, an accident with a teletherapy source made of {sup 137}CsCl with an initial activity of 59 TBq occurred in Goiania, in September of 1987. This paper will discuss the decision-making process, and the struggle that followed the decision to build the final repository for the remnants of the Goiania accident. The Goiania final repository was built as planned. The two subsurface structures under the grassy artificial hills hold the overall volume of the remnants of the Goiania accident. The near hill holds 5x10{sup 3} m3 of stabilized wastes without radioactivity, or with very low radioactivity. The far hill holds the remaining 6.5x10{sup 3} m{sup 3} of stabilized wastes with low and medium radioactivity. The central part of each subsurface hill has been shielded by wastes with less and less radioactivity. The overall fenced area occupies 1.85x10{sup 5} m{sup 2}. The external radiation levels are similar to the surrounding background, and much lower than those found in the Brazilian areas of high natural radioactivity. The site is permanently monitored by independent institutions, including Brazilian universities, and national and international organizations. As it was mentioned earlier, the final repository was build to last for at least 400 years. Although the initial decision to adopt a too conservative decontamination criterion in the case of the Goiania accident was bound to produce excessive amount of waste; such decision proved, retrospectively, not to be bad because the excess low radioactive waste produced was used as extra shielding material in final repository. The technical decision-maker should not abandon risk estimates, but should be aware that credibility is the main basis to achieve acceptability of a decision by the general public. Risk perception should be regarded as only a first step towards what may be called knowledge, or comprehension of risk estimates, but risk perception by the general public is still an open issue. The

Double Diffusive Natural Convection in a Nuclear Waste Repository

International Nuclear Information System (INIS)

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

2006-01-01

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

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

International Nuclear Information System (INIS)

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

1984-01-01

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

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

The technical challenge of mechanized excavation for nuclear waste repositories

International Nuclear Information System (INIS)

Smith, A.I.

1991-01-01

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

Operational experience from SFR - Final repository for low- and intermediate level waste in Sweden

International Nuclear Information System (INIS)

Skogsberg, Marie; Ingvarsson, Roger

2006-01-01

SFR, the Swedish Final Repository for Radioactive Waste, has been in operation since April 1988. It was designed for short lived LLW/ILW from the operation and maintenance of all Swedish Nuclear Power Plants. The first stage was constructed for 63 000 m 3 which was assumed to give a margin and flexibility for the preliminary operational period. Today this volume represents the whole prediction of operational waste. Until the end of 2005 SFR has received 30 930 m 3 waste. In average it has been 2-3 derivations per year at the repository. The most derivations happened in the years 1993-1995, and that was also the years when the repository received the most volume of waste. The most of the derivations those years was related to the waste packages. The dose rate to the personal has always been very low in the latest years the collective dose has been under 0,1 mmanSv/year. (author)

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

Energy Technology Data Exchange (ETDEWEB)

1981-01-01

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

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

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

International Nuclear Information System (INIS)

1999-10-01

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

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

Energy Technology Data Exchange (ETDEWEB)

NONE

1999-10-01

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

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

The status of radioactive waste repository development in the United States - December 2011

International Nuclear Information System (INIS)

Hill, David R.

2012-01-01

The current state of affairs concerning development in the United States of a permanent repository for disposal of spent nuclear fuel (SNF) and high-level radioactive waste (HLW) is, in a word, uncertain. The President of the United States has asserted that he believes licensing and development of the Yucca Mountain repository should be abandoned, while other important parties believe licensing and development should continue. And not surprisingly, there is a disagreement as to what the law requires and whether the licensing process for the Yucca Mountain repository can be terminated at this point, even if the President would like for that to happen. The future of Yucca Mountain, and the future of radioactive waste disposal in the United States generally, currently are pending before the US Court of Appeals for the District of Columbia Circuit, and eventually the Supreme Court of the United States may decide some of the important legal issues concerning Yucca Mountain's future. The November 2012 US elections also likely will have a significant impact on future radioactive waste repository development

Preliminary drift design analyses for nuclear waste repository in tuff

International Nuclear Information System (INIS)

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

1990-01-01

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

Project study for the final disposal of intermediate toxicity radioactive wastes (low- and intermediate-level radioactive wastes) in geological formations

International Nuclear Information System (INIS)

1980-08-01

The present report aimed to show variations in the construction- and operation-technical feasibility of a final repository for low- and intermediate-level radioactive wastes. This report represents the summary of a project study given under contract by Nagra with a view to informing a broader public of the technical conception of a final repository. Particular stress was laid on the treatment of the individual system elements of a repository concept during the construction, operation and sealing phases. The essential basis for the project study is the origin, composition and quantity of the wastes to be disposed. The final repository described in this report is foreseen for the reception of the following low- and intermediate-level solid radioactive wastes: wastes from the nuclear power plant operation; secondary wastes from the reprocessing of nuclear fuels; wastes from the decommissioning of nuclear power plants; wastes from research, medicine and industry

Integrity of radioactive waste packages at the Yucca mountain repository

International Nuclear Information System (INIS)

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

2004-01-01

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

Conceptual design of the Brazilian near surface repository

International Nuclear Information System (INIS)

Mourao, Rogerio P.; Freire, Carolina Braccini

2013-01-01

CNEN is presently in the planning phase of the implementation of a repository for low and intermediate level wastes. One of the present activities of this project is to define a concept for the disposal of radioactive wastes to be received. The conceptual design of the repository takes into account the quantities and characteristics of the waste, the disposal arrangement, the waste acceptance criteria, the site characteristics, the period of the facility operation and institutional control, the engineering barriers to be used, as well as the facility's operational aspects. The facility will be a near-surface repository, an internationally accepted concept and adopted for example in France (L'Aube repository) and Spain (El Cabril). An acceptable site for such a repository must have characteristics that minimize the risk of human exposure to the radiation and environmental contamination. For this, the chosen site must meet specific technical and socioeconomic requirements, such as favorable physiographic, meteorological, geotechnical and tectonic characteristics, low demographic density, absence of agricultural activities and mineral deposits and proximity to the paved road grid. In this work the technical and socioeconomic requirements necessary and sufficient for site selection are presented. Also discussed is the method for the establishment of the main features that the different facility's buildings must have. Since a specific site has not yet been selected, a simulated area with straight and parallel sides, no gradient, served by access road and having a surface sufficient to hold the disposal structures and support facilities, as well as the legal exclusion zones. The buildings were designed and positioned in order to meet the needs in terms of flow of waste, personnel, supplies and materials necessary to perform the activities within the enterprise. The methodology for compilation of information related to buildings is presented. This information will be

Source terms for analysis of accidents at a high level waste repository

International Nuclear Information System (INIS)

Mubayi, V.; Davis, R.E.; Youngblood, R.

1989-01-01

This paper describes an approach to identifying source terms from possible accidents during the preclosure phase of a high-level nuclear waste repository. A review of the literature on repository safety analyses indicated that source term estimation is in a preliminary stage, largely based on judgement-based scoping analyses. The approach developed here was to partition the accident space into domains defined by certain threshold values of temperature and impact energy density which may arise in potential accidents and specify release fractions of various radionuclides, present in the waste form, in each domain. Along with a more quantitative understanding of accident phenomenology, this approach should help in achieving a clearer perspective on scenarios important to preclosure safety assessments of geologic repositories. 18 refs., 3 tabs

Mapping and monitoring nuclear waste repositories with subsurface electrical resistivity arrays

International Nuclear Information System (INIS)

Asch, T.; Morrison, H.F.

1987-01-01

The siting and future integrity of nuclear waste repositories is critically dependent on the local ground water regime. Electrical methods seem particularly promising in mapping and monitoring this regime since the electrical conductivity of rocks depends almost entirely on the fluid saturation, salinity and distribution. The most important recent developments in resistivity include the use of numerical modeling and resistivity mapping using subsurface electrodes. The latter yields far greater accuracy and resolution than can be obtained with surface arrays. To illustrate the power of subsurface-surface arrays the authors studied an idealized two dimensional model of a nuclear repository. Since they are interested in emphasizing the anomaly caused by the repository, or subsequent changes over time in its vicinity, the authors discovered that it is very useful to express the apparent resistivity results as percentage differences from either the background (for surface arrays) or from the apparent resistivities observed at a particular depth of the current source (for subsurface arrays). Percent differencing with respect to data at the repository depth dramatically reduce near-surface and topographic effects that usually confound quantitative interpretation of surface surveys. Thus, dc resistivity appears to have great potential for nuclear waste repository mapping and monitoring

Pre-feasibility study for final disposal of radioactive waste. Disposal concepts. Main report

International Nuclear Information System (INIS)

Andersen, L.; Skov, C.; Kueter, A.; Schepper, L.; Gottberg Roemer, H.; Refsgaard, A.; Utko, M.; Kristiansen, Torben

2011-05-01

This prefeasibility study is part of the overall process related to the decision on placement and design of a repository for the Danish low and medium level radioactive waste primarily from the facilities at Risoe. The prefeasibility study encompasses the preliminary design of a number of repository types based on the overall types set out in the 'Parliamentary decision' together with a preliminary safety assessment of these repository types based on their possible placement in a set of typical Danish geologies. The report consists of three parts. Part I is the descriptive part containing information on the waste to be disposed of, the potential conditioning (packaging) possibilities for the waste before placement in a repository, the suggested preliminary design of the different repository types, and the suggested visual appearance of the repository. Part II is the assessment part. It contains an introduction to the concepts used in the preliminary safety assessment, which encompasses: the assessment of potential long term impact and the assessment of possible accidental incidents. The division of the preliminary safety assessment in to these two categories has several reasons. One is that the criteria to which impact is to be compared are different for the two types of impact, another is that while the possible variation in the long term impact is primarily due to the possible variation in the parameters influencing the impact, the impact from accidental incidents is governed by the probability of the occurrence of these incidents and the potential consequence of the impact, which calls for a different assessment approach. Since the suggestions for packaging of the different waste types is a result of both types of assessments, part II also contains a description of these suggestions based on the preliminary safety assessments. Finally part II contains the costs related to the different types of repositories and the suggested packaging. Part III of the report

Pre-feasibility study for final disposal of radioactive waste. Disposal concepts. Main report

Energy Technology Data Exchange (ETDEWEB)

Andersen, L.; Skov, C.; Kueter, A.; Schepper, L.; Gottberg Roemer, H.; Refsgaard, A.; Utko, M.; Kristiansen, Torben (COWI A/S, Kgs. Lyngby (Denmark))

2011-05-15

This prefeasibility study is part of the overall process related to the decision on placement and design of a repository for the Danish low and medium level radioactive waste primarily from the facilities at Risoe. The prefeasibility study encompasses the preliminary design of a number of repository types based on the overall types set out in the 'Parliamentary decision' together with a preliminary safety assessment of these repository types based on their possible placement in a set of typical Danish geologies. The report consists of three parts. Part I is the descriptive part containing information on the waste to be disposed of, the potential conditioning (packaging) possibilities for the waste before placement in a repository, the suggested preliminary design of the different repository types, and the suggested visual appearance of the repository. Part II is the assessment part. It contains an introduction to the concepts used in the preliminary safety assessment, which encompasses: the assessment of potential long term impact and the assessment of possible accidental incidents. The division of the preliminary safety assessment in to these two categories has several reasons. One is that the criteria to which impact is to be compared are different for the two types of impact, another is that while the possible variation in the long term impact is primarily due to the possible variation in the parameters influencing the impact, the impact from accidental incidents is governed by the probability of the occurrence of these incidents and the potential consequence of the impact, which calls for a different assessment approach. Since the suggestions for packaging of the different waste types is a result of both types of assessments, part II also contains a description of these suggestions based on the preliminary safety assessments. Finally part II contains the costs related to the different types of repositories and the suggested packaging. Part III of the

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.

Long-Term Waste Package Degradation Studies at the Yucca Mountain Potential High-Level Nuclear Waste Repository

International Nuclear Information System (INIS)

Mon, K. G.; Bullard, B. E.; Longsine, D. E.; Mehta, S.; Lee, J. H.; Monib, A. M.

2002-01-01

The Site Recommendation (SR) process for the potential repository for spent nuclear fuel (SNF) and high-level nuclear waste (HLW) at Yucca Mountain, Nevada is underway. Fulfillment of the requirements for substantially complete containment of the radioactive waste emplaced in the potential repository and subsequent slow release of radionuclides from the Engineered Barrier System (EBS) into the geosphere will rely on a robust waste container design, among other EBS components. Part of the SR process involves sensitivity studies aimed at elucidating which model parameters contribute most to the drip shield and waste package degradation characteristics. The model parameters identified included (a) general corrosion rate model parameters (temperature-dependence and uncertainty treatment), and (b) stress corrosion cracking (SCC) model parameters (uncertainty treatment of stress and stress intensity factor profiles in the Alloy 22 waste package outer barrier closure weld regions, the SCC initiation stress threshold, and the fraction of manufacturing flaws oriented favorably for through-wall penetration by SCC). These model parameters were reevaluated and new distributions were generated. Also, early waste package failures due to improper heat treatment were added to the waste package degradation model. The results of these investigations indicate that the waste package failure profiles are governed by the manufacturing flaw orientation model parameters and models used

Nuclear waste repository simulation experiments

International Nuclear Information System (INIS)

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

1986-12-01

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

Tunnel Boring Machine for nuclear waste repository research project

International Nuclear Information System (INIS)

Janzon, H.A.

1994-01-01

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

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

International Nuclear Information System (INIS)

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

1991-01-01

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

Durability of cemented waste in repository and under simulated conditions

International Nuclear Information System (INIS)

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

2000-01-01

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

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

International Nuclear Information System (INIS)

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

2000-01-01

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

Numerical modeling of the geomechanical response of a rock mass to a radioactive waste repository

International Nuclear Information System (INIS)

Hardy, M.P.; St John, C.M.; Hocking, G.

1979-06-01

Geotechnical numerical models capable of predicting the thermomechanical response and groundwater movements around an underground radioactive waste repository are vital to the success of the nuclear waste disposal program. In the absence of directly related engineering experience, the design, risk assessment, and licensing procedures of a repository will be reliant on predictions made using such models. This paper reviews models being used to assist in repository design and summarizes the results of a recent parametric study of underground disposal in basaltic rocks. On the basis of preliminary site data, it is concluded that the allowable areal density of heat-generating waste will be controlled by the stability of placement rooms and the boreholes in which waste canisters are placed. Regional effects including thermally induced upward groundwater flow, appear to present less severe problems

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

Transferring knowledge about high-level waste repositories: An ethical consideration

International Nuclear Information System (INIS)

Berndes, S.; Kornwachs, K.

1996-01-01

The purpose of this paper is to present requirements to Information and Documentation Systems for high-level waste repositories from an ethical point of view. A structured synopsis of ethical arguments used by experts from Europe and America is presented. On the one hand the review suggests to reinforce the obligation to transfer knowledge about high level waste repositories. This obligation is reduced on the other hand by the objection that ethical obligations are dependent on the difference between our and future civilizations. This reflection results in proposing a list of well-balanced ethical arguments. Then a method is presented which shows how scenarios of possible future civilizations for different time horizons and related ethical arguments are used to justify requirements to the Information and Documentation System

A Probabilistic Consideration on Nuclide Releases from a Pyro-processed Waste Repository

Energy Technology Data Exchange (ETDEWEB)

Lee, Youn Myoung; Jeong, Jong Tae [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2012-05-15

Very recently, a GoldSim template program, GSTSPA, for a safety assessment of a conceptual hybrid-typed repository system, called 'A-KRS,' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyroprocessing of PWR nuclear spent fuels, has been developed and is to be disposed of by 'separate disposal' strategies. The A-KRS is considered to be constructed at two different depths in geological media: at a 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and at a 500m depth, believed to be the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for a probabilistic total system performance assessment (TSPA) which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of a waste package and canister with associated uncertainty. To quantify the nuclide release and transport through the various possible pathways in the near- and far-fields of the A-KRS repository system under a normal groundwater flow scenario, some illustrative evaluations have been made through this study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

A Probabilistic Consideration on Nuclide Releases from a Pyro-processed Waste Repository

International Nuclear Information System (INIS)

Lee, Youn Myoung; Jeong, Jong Tae

2012-01-01

Very recently, a GoldSim template program, GSTSPA, for a safety assessment of a conceptual hybrid-typed repository system, called 'A-KRS,' in which two kinds of pyroprocessed radioactive wastes, low-level metal wastes and ceramic high-level wastes that arise from the pyroprocessing of PWR nuclear spent fuels, has been developed and is to be disposed of by 'separate disposal' strategies. The A-KRS is considered to be constructed at two different depths in geological media: at a 200m depth, at which a possible human intrusion is considered to be limited after closure, for the pyroprocessed metal wastes with lower or no decay heat producing nuclides, and at a 500m depth, believed to be the reducing condition for nuclides with a rather higher radioactivity and heat generation rate. This program is ready for a probabilistic total system performance assessment (TSPA) which is able to evaluate nuclide release from the repository and farther transport into the geosphere and biosphere under various normal, disruptive natural and manmade events, and scenarios that can occur after a failure of a waste package and canister with associated uncertainty. To quantify the nuclide release and transport through the various possible pathways in the near- and far-fields of the A-KRS repository system under a normal groundwater flow scenario, some illustrative evaluations have been made through this study. Even though all parameter values associated with the A-KRS were assumed for the time being, the illustrative results should be informative since the evaluation of such releases is very important not only in view of the safety assessment of the repository, but also for design feedback of its performance

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

International Nuclear Information System (INIS)

Hossain, Q.A.

1994-02-01

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

Qualifying concrete for a low-level waste repository

International Nuclear Information System (INIS)

Philipose, K.E.

1990-06-01

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

Project Guarantee 1985. Final repository for low- and intermediate-level radioactive wastes: The system of safety barriers

International Nuclear Information System (INIS)

Anon.

1985-01-01

The safety barrier system for the type B repository for low- and intermediate-level waste is described. The barrier parameters which are relevant for safety analysis are quantified and associated error limits and data scatter are given. The aim of the report is to give a summary documentation of the safety analysis input data and their scientific background. For secure containment of radioactive waste safety barriers are used which effectively limit the release of radioactive material from the repository (release barriers) and effectively retard the entry of the original radioactive material into the biosphere (time barriers). In the case of low- and intermediate-level waste the technical safety barrier system comprises: waste solidification matrix (cement, bitumen and resin), immobilisation of the waste packages in containers using liquid cement, concrete repository containers, backfilling of remaining vacant storage space with special concrete, concrete lining of the repository caverns, sealing of access tunnels on final closure of the repository. Natural geological safety barriers - host rock and overlying formations - have the following important functions. Because of its stability, the host rock in the repository zone protects the technical safety barrier system from destruction caused by climatic effects and erosion for a sufficient length of time. It also provides for low water flow and favourable chemistry (reducing conditions)

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

International Nuclear Information System (INIS)

Seitz, M.G.

1981-01-01

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

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

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

Nuclear Waste Disposal Program 2016

International Nuclear Information System (INIS)

2016-12-01

This comprehensive brochure published by the Swiss National Cooperative for the Disposal of Radioactive Waste (NAGRA) discusses the many important steps in the management of radioactive waste that have already been implemented in Switzerland. The handling and packaging of waste, its characterisation and inventorying, as well as its interim storage and transport are examined. The many important steps in Swiss management of radioactive waste already implemented and wide experience gained in carrying out the associated activities are discussed. The legal framework and organisational measures that will allow the selection of repository sites are looked at. The various aspects examined include the origin, type and volume of radioactive wastes, along with concepts and designs for deep geological repositories and the types of waste to be stored therein. Also, an implementation plan for the deep geological repositories, the required capacities and the financing of waste management activities are discussed as is NAGRA’s information concept. Several diagrams and tables illustrate the program

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