WorldWideScience

Sample records for nuclear fuel repositories

  1. Thermal analyses of spent nuclear fuel repository

    International Nuclear Information System (INIS)

    Ikonen, K.

    2003-06-01

    This report contains the temperature dimensioning of the KBS-3V type 1- or 2-panel repository based on the rock properties measured from the Olkiluoto investigations. The report describes first the development of a calculation methodology for the thermal analysis of a repository for nuclear fuel. The disposed canisters produce residual heat due to decay (or disintegration) of radioactive products. The decay heat is conducted to surrounding rock mass. The methods were applied to determine the effect of different parameters on the highest canister temperature and to support the planning, dimensioning and operation of the repository. The thermal diffusivity of the rock is low and the heat released from the canisters is spread into the surrounding rock volume quite slowly causing thermal gradient in the rock close to canisters and the canister temperature is increased remarkably. The maximum temperature on the canister surface is limited to the design temperature of +100 deg C. However, due to uncertainties in thermal analysis parameters (like scattering in rock conductivity) the allowable calculated maximum canister temperature is set to 90 deg C causing a safety margin of 10 deg C. The allowable temperature is controlled by the spacing between adjacent canisters, adjacent tunnels and the distance between separate panels of the repository and the pre-cooling time affecting power of the canisters. Because of the fact that the disposal operation takes several decades, the moment of disposal of an individual canister in addition to the location has an influence on the maximum temperature in the canister. Also, a second disposal panel in the repository has a thermal interaction with the other panel. This interaction is expressed after a few decades at the strongest. It became apparent that the temperature of canister surfaces can be determined by analytic line heat source model much more efficiently than by numerical analysis, if the analytic model is first verified and

  2. Spent nuclear fuel for disposal in the KBS-3 repository

    International Nuclear Information System (INIS)

    Grahn, Per; Moren, Lena; Wiborgh, Maria

    2010-12-01

    The report is included in a set of Production reports, presenting how the KBS-3 repository is designed, produced and inspected. The set of reports is included in the safety report for the KBS-3 repository and repository facility. The report provides input to the assessment of the long-term safety, SR-Site as well as to the operational safety report, SR-Operation. The report presents the spent fuel to be deposited, and the requirements on the handling and selection of fuel assemblies for encapsulation that follows from that it shall be deposited in the KBS-3 repository. An overview of the handling and a simulation of the encapsulation and the resulting canisters to be deposited are presented. Finally, the initial state of the encapsulated spent nuclear fuel is given. The initial state comprises the radionuclide inventory and other data required for the assessment of the long-term safety

  3. Spent nuclear fuel for disposal in the KBS-3 repository

    Energy Technology Data Exchange (ETDEWEB)

    Grahn, Per; Moren, Lena; Wiborgh, Maria

    2010-12-15

    The report is included in a set of Production reports, presenting how the KBS-3 repository is designed, produced and inspected. The set of reports is included in the safety report for the KBS-3 repository and repository facility. The report provides input to the assessment of the long-term safety, SR-Site as well as to the operational safety report, SR-Operation. The report presents the spent fuel to be deposited, and the requirements on the handling and selection of fuel assemblies for encapsulation that follows from that it shall be deposited in the KBS-3 repository. An overview of the handling and a simulation of the encapsulation and the resulting canisters to be deposited are presented. Finally, the initial state of the encapsulated spent nuclear fuel is given. The initial state comprises the radionuclide inventory and other data required for the assessment of the long-term safety

  4. Evaluation of a potential nuclear fuel repository criticality: Lessons learned

    Energy Technology Data Exchange (ETDEWEB)

    Wilson, J.R.; Evans, D.

    1995-10-01

    This paper presents lessons learned from a Probabilistic Risk Assessment (PRA) of the potential for a criticality in a repository containing spent nuclear fuel with high enriched uranium. The insights gained consisted of remarkably detailed conclusions about design issues, failure mechanisms, frequencies and source terms for events up to 10,000 years in the future. Also discussed are the approaches taken by the analysts in presenting this very technical report to a nontechnical and possibly antagonistic audience.

  5. Evaluation of a potential nuclear fuel repository criticality: Lessons learned

    International Nuclear Information System (INIS)

    Wilson, J.R.; Evans, D.

    1995-01-01

    This paper presents lessons learned from a Probabilistic Risk Assessment (PRA) of the potential for a criticality in a repository containing spent nuclear fuel with high enriched uranium. The insights gained consisted of remarkably detailed conclusions about design issues, failure mechanisms, frequencies and source terms for events up to 10,000 years in the future. Also discussed are the approaches taken by the analysts in presenting this very technical report to a nontechnical and possibly antagonistic audience

  6. Preliminary plan for decommissioning - repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Hallberg, Bengt; Tiberg, Liselotte

    2010-06-01

    The final disposal facility for spent nuclear fuel is part of the KBS-3 system, which also consists of a central facility for interim storage and encapsulation of the spent nuclear fuel and a transport system. The nuclear fuel repository will be a nuclear facility. Regulation SSMFS 2008:1 (Swedish Radiation Safety Authority's regulations on safety of nuclear facilities) requires that the licensee must have a current decommissioning plan throughout the facility lifecycle. Before the facility is constructed, a preliminary decommissioning plan should be reported to the Swedish Radiation Safety Authority. This document is a preliminary decommissioning plan, and submitted as an attachment to SKB's application for a license under the Nuclear Activities Act to construct, own and operate the facility. The final disposal facility for spent nuclear fuel consists of an above ground part and a below ground part and will be built near Forsmark and the final repository for radioactive operational waste, SFR. The parts above and below ground are connected by a ramp and several shafts, e.g. for ventilation. The below ground part consists of a central area, and several landfill sites. The latter form the repository area. The sealed below ground part constitutes the final repository. The decommissioning is taking place after the main operation has ended, that is, when all spent nuclear fuel has been deposited and the deposition tunnels have been backfilled and plugged. The decommissioning involves sealing of the remaining parts of the below ground part and demolition of above ground part. When decommissioning begins, there will be no contamination in the facility. The demolition is therefore performed as for a conventional plant. Demolition waste is sorted and recycled whenever possible or placed in landfill. Hazardous waste is managed in accordance with current regulations. A ground investigation is performed and is the basis for after-treatment of the site. The timetable for the

  7. Repository for spent nuclear fuel. Plant description layout D - Forsmark

    International Nuclear Information System (INIS)

    2010-07-01

    This document describes the final repository for spent nuclear fuel, SFK, which is located at Forsmark, in Oesthammar. The bedrock at the site is part of a so-called tectonic lens, in which the rock composition is relatively homogeneous and less deformed than outside the lens. The bedrock consists mainly of granite with high quartz content and good thermal conductivity. The central parts above ground are grouped in an operations area, located at the Soederviken on the south side of the intake duct for cooling water for nuclear power plant. Operating area is divided into an internal, secured portion, where the canisters of fuel are handled and there are links to the underground part, and a outer part, where the buffer, backfill and sealing used in the repository's barriers are produced. The above-ground part of the plant and also include storage of excavated rock, ventilation stations, and supplies of bentonite. The underground portion consists of a central area and a storage area. Caverns of the central area contain features for the underground operation. It communicates with the internal operating range above ground via a spiral ramp and several shafts. The ramp used to transport capsules of spent fuel and other heavy or bulky transport. The shafts are used to transport rock, buffer, backfill and staff, as well as for ventilation. The largest part of the space below ground is the repository where the canisters with the spent fuel are disposed. The capsules are deposited in vertical holes in the tunnels. When the deposit in a tunnel is complete, the tunnel is re-filled. The two main activities underground is rock work and disposal work, which are conducted separately from each other. Rock works covers all steps required to excavate tunnels and drill deposition holes, as well as to make temporary installations in the tunnels. To the landfill works count, besides the deposit of the capsule, the placement of the bentonite buffer in the deposition hole and backfilling

  8. Method for storing spent nuclear fuel in repositories

    Science.gov (United States)

    Schweitzer, Donald G.; Sastre, Cesar; Winsche, Warren

    1981-01-01

    A method for storing radioactive spent fuel in repositories containing sulfur as the storage medium is disclosed. Sulfur is non-corrosive and not subject to radiation damage. Thus, storage periods of up to 100 years are possible.

  9. Site selection for Canada's national repository for used nuclear fuel

    International Nuclear Information System (INIS)

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

    2015-01-01

    In 2007, the Government of Canada selected Adaptive Phased Management as Canada's plan for the long-term management of Canada's used nuclear fuel. The approach provides for containment and isolation of the material in a deep geological repository at a safe site with an informed and willing host. The Nuclear Waste Management Organization is tasked through federal legislation with selecting the site and developing and managing all aspects of the plan. In May 2010, the organization published and initiated the site selection process that serves as a road map for decision making on the location for the deep geological repository. It continues to lead the site selection process for the repository and an associated Centre of Expertise. The screening process is advancing and, from an initial starting point of 22 communities expressing interest in learning about the project; as of September 2015, 9 communities are the focus of more detailed technical and community well-being studies. Preliminary Assessments, the third step in the 9-step site selection process are underway in these communities. The Assessments involve preliminary technical and social desktop and field assessments, engagement activities within and beyond each interested community, and involvement of Indigenous peoples and nearby municipalities in the planning and conduct of the work. This paper provides an update on the advancement of the site selection process. It describes the nature of the technical and social studies being conducted at this phase of work, including the progressively more detailed field studies that are the focus of technical work at the current stage, the approach to engagement and collaboration with communities to direct these studies, and the work underway to ensure the framework used for this assessment and engagement includes the range of priorities and perspectives of First Nations and Metis peoples and communities in the broader area. (author)

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

    International Nuclear Information System (INIS)

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

    1999-12-01

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

  11. Principal organic materials in a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Hallbeck, Lotta

    2010-01-01

    the redox potential within the repository. The products of cellulose degradation may help enhance the complexing capacity of the groundwater around the repository, so the amount of cellulose left in the repository should be minimised. 4. Fuels and engine emissions. No important effects are expected from these organic materials in the repository. Although the presence of aromatic compounds and PAHs in groundwater is not desirable in itself, these compounds are of no consequence for long-term repository performance. 5. Detergents and lubricants. The same reasoning as for fuels and engine emissions can be applied to these materials. The amount of detergents should be minimised, although in the amounts in which they are expected to occur, no important impact is foreseen. 6. Materials from human activities. Of these materials, fibres from clothes could have a more important effect, due to the presence of cellulose. Accordingly, human-related wastes should me minimised, although no large amounts of these materials are expected to be present after repository closure. Three processes are considered to have the largest potential impact on repository performance: i) Increasing the reducing capacity and reducing the redox potential in the short term, and increasing the depletion rate of oxygen trapped during the repository operation stage. ii) Increasing the complexing capacity of the groundwater due to the presence of organic complexants, which is expected to be a more relevant process in the long term. Many organic molecules with complexing capacity, for example, short-chain organic acids such as acetate, however, will be oxidised due to microbial metabolism. The projected acetate concentration in groundwater is below the detection limit of available analytical methods. The amount of organic material in groundwater is usually only being a few mg L-1, and 25-75% of this material is non-humic material, i.e. short-chain acids. iii) Production of HS- from the oxidation of short

  12. Principal organic materials in a repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Hallbeck, Lotta (Microbial Analytics Sweden AB, Moelnlycke (Sweden))

    2010-01-15

    the redox potential within the repository. The products of cellulose degradation may help enhance the complexing capacity of the groundwater around the repository, so the amount of cellulose left in the repository should be minimised. 4. Fuels and engine emissions. No important effects are expected from these organic materials in the repository. Although the presence of aromatic compounds and PAHs in groundwater is not desirable in itself, these compounds are of no consequence for long-term repository performance. 5. Detergents and lubricants. The same reasoning as for fuels and engine emissions can be applied to these materials. The amount of detergents should be minimised, although in the amounts in which they are expected to occur, no important impact is foreseen. 6. Materials from human activities. Of these materials, fibres from clothes could have a more important effect, due to the presence of cellulose. Accordingly, human-related wastes should me minimised, although no large amounts of these materials are expected to be present after repository closure. Three processes are considered to have the largest potential impact on repository performance: i) Increasing the reducing capacity and reducing the redox potential in the short term, and increasing the depletion rate of oxygen trapped during the repository operation stage. ii) Increasing the complexing capacity of the groundwater due to the presence of organic complexants, which is expected to be a more relevant process in the long term. Many organic molecules with complexing capacity, for example, short-chain organic acids such as acetate, however, will be oxidised due to microbial metabolism. The projected acetate concentration in groundwater is below the detection limit of available analytical methods. The amount of organic material in groundwater is usually only being a few mg L-1, and 25-75% of this material is non-humic material, i.e. short-chain acids. iii) Production of HS- from the oxidation of short

  13. Site selection - siting of the final repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    2011-03-01

    SKB has selected Forsmark as the site for the final repository for spent nuclear fuel. The site selection is the end result of an extensive siting process that began in the early 1990s. The strategy and plan for the work was based on experience from investigations and development work over a period of more than ten years prior to then. This document describes the siting work and SKB's choice of site for the final repository. It also presents the information on which the choice was based and the reasons for the decisions made along the way. The document comprises Appendix PV to applications under the Nuclear Activities Act and the Environmental Code for licences to build and operate an encapsulation plant adjacent to the central interim storage facility for spent nuclear fuel in Oskarshamn, and to build and operate a final repository for spent nuclear fuel in Forsmark in Oesthammar Municipality

  14. Site selection - siting of the final repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    2011-03-15

    SKB has selected Forsmark as the site for the final repository for spent nuclear fuel. The site selection is the end result of an extensive siting process that began in the early 1990s. The strategy and plan for the work was based on experience from investigations and development work over a period of more than ten years prior to then. This document describes the siting work and SKB's choice of site for the final repository. It also presents the information on which the choice was based and the reasons for the decisions made along the way. The document comprises Appendix PV to applications under the Nuclear Activities Act and the Environmental Code for licences to build and operate an encapsulation plant adjacent to the central interim storage facility for spent nuclear fuel in Oskarshamn, and to build and operate a final repository for spent nuclear fuel in Forsmark in Oesthammar Municipality

  15. Creep Analysis of Aluminum-Based Spent Nuclear Fuel in Repository Storage

    International Nuclear Information System (INIS)

    Gong, C.; Lam, P.S.; Sindelar, R.L.

    1998-07-01

    Aluminum-clad, aluminum-based spent nuclear fuels (Al SNF) from foreign and domestic research reactors are being consolidated at the Savannah River Site (SRS). These fuels are planned to be put into dry storage followed by disposal in the federal repository. Temperature conditions in storage and disposal systems due to nuclear decay heat sources will promote creep information of the fuel elements. Excessive deformation of the Al SNF will cause gross distortion (slump) of the fuels and may cause gross cladding rupture

  16. Dose calculation for accident situations at WWR-S type spent nuclear fuel repository

    International Nuclear Information System (INIS)

    Margeanu, S.; Florescu, G.

    2006-01-01

    Full text: The Spent Nuclear Fuel Repository at IFIN-HH Bucharest (SNFR IFIN-HH) consists in four pools, repository hall, radiological monitoring system, ventilation system and auxiliary systems. At the moment the remaining activity in the repository is about 3500 Ci. Despite of the small activity, for emergency preparedness purposes, several accident scenarios, with a non zero probability of occurrence during the repository lifetime, have been postulated. Evaluations of radiological consequences to personnel, general public and environment, for each accident scenario have been performed. The radioactive inventory was evaluated with ORIGEN code from SCALE computer code system and radiological consequences were evaluated with COSYMA computer code. Assumptions for the source term determination, meteorological conditions and release, are presented. The calculated values of doses and risk are also presented. The impact of these accident scenarios on population and environment is also discussed. (authors)

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

    CERN Document Server

    American Society for Testing and Materials. Philadelphia

    2009-01-01

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

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

    International Nuclear Information System (INIS)

    Nutt, W.M.

    1990-02-01

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

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2011-07-01

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

  2. Licensing process characteristics of Small Modular Reactors and spent nuclear fuel repository

    Energy Technology Data Exchange (ETDEWEB)

    Söderholm, Kristiina, E-mail: kristiina.soderholm@fortum.com [Fortum Power (Finland); Tuunanen, Jari, E-mail: jari.tuunanen@fortum.com [Fortum Power (Finland); Amaba, Ben, E-mail: baamaba@us.ibm.com [IBM Complex Systems (United States); Bergqvist, Sofia, E-mail: sofia.bergqvist@se.ibm.com [IBM Rational Software (Sweden); Lusardi, Paul, E-mail: plusardi@nuscalepower.com [NuScale Power (United States)

    2014-09-15

    Highlights: • We examine the licensing process challenges of modular nuclear facilities. • We compare the features of Small Modular Reactors and spent nuclear fuel repository. • We present the need of nuclear licensing simplification. • Part of the licensing is proposed to be internationally applicable. • Systems engineering and requirements engineering benefits are presented. - Abstract: This paper aims to increase the understanding of the licensing processes characteristics of Small Modular Reactors (SMR) compared with licensing of spent nuclear fuel repository. The basis of the SMR licensing process development lies in licensing processes used in Finland, France, the UK, Canada and the USA. These countries have been selected for this study because of their various licensing processes and recent actions in the new NPP construction. Certain aspects of the aviation industry licensing process have also been studied and selected practices have been investigated as possibly suitable for use in nuclear licensing. Suitable features for SMR licensing are emphasized and suggested. The licensing features of the spent nuclear fuel deep repository along with similar features of SMR licensing are discussed. Since there are similar types of challenges of lengthy licensing time frames, as well as modular features to be taken into account in licensing, these two different nuclear industry fields can be compared. The main SMR features to take into account in licensing are: • Standardization of the design. • Modularity. • Mass production. • Serial construction. Modularity can be divided into two different categories: the first category is simply a single power plant unit constructed of independently engineered modules (e.g. construction process for Westinghouse AP-1000 NPP) and the second one a power plant composed of many reactor modules, which are manufactured in factories and installed as needed (e.g. NuScale Power SMR design). The deep underground repository

  3. The evolving image and role of the regulator for implementing repositories for nuclear waste and spent nuclear fuel

    International Nuclear Information System (INIS)

    Melin, J.

    2005-01-01

    A country introducing nuclear power in their energy strategy has a life long obligation. The obligation is not mainly a question of energy production. It is an obligation to maintain safety during the phase of construction, energy production and decommissioning as well as to take care of all the waste streams from nuclear installations. I believe that one of the most controversial siting projects in the society is a waste repository for spent nuclear fuel. Competence, available funds and a clear responsibility between the stakeholders as well as the trust of the public is indispensable to obtain a good result. The Swedish programme for managing nuclear waste and spent nuclear fuel has been in progress for more than 25 years. The pre-licensing process of a repository for spent nuclear fuel is much alike a pre-licensing process for the first nuclear power plant in a country. You need a clear political will, you have to involve the nuclear regulator without jeopardizing his integrity and you need the money to perform research and make the investments. The enthusiasm of politicians and industry may however differ between these two projects. (author)

  4. Local negotiation on compensation siting of the spent nuclear fuel repository in Finland

    International Nuclear Information System (INIS)

    Kojo, Matti

    2007-01-01

    The aim of the paper is to analyse the local negotiation process between the Municipality of Eurajoki and the nuclear power company Teollisuuden Voima (TVO) and the nuclear waste management company Posiva Oy. The aim of the negotiations was to find an acceptable form of compensation for siting a spent nuclear fuel repository in Olkiluoto, Finland. The paper includes background information on the siting process in Finland, the local political setting in the Municipality of Eurajoki and a description of the negotiation process. The analysis of the negotiations on compensation is important for better understanding the progress of the Finnish siting process. The paper describes the picture of the contest to host the spent nuclear fuel repository. It also provides more information on the relationship between the Municipality of Eurajoki and the power company TVO. The negotiations on compensation and the roles of various players in the negotiations have not been studied in detail because the minutes of the Vuojoki liaison group were not available before the decision of the Supreme Administrative Court in May 2006. (author)

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

    International Nuclear Information System (INIS)

    Hedin, A.

    1999-11-01

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

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

    International Nuclear Information System (INIS)

    Facella, J.

    2014-01-01

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

  7. Review study 1995. Localization of the repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    1995-10-01

    This report gives an overview of the studies performed by SKB pertinent to selection of a site for the Swedish repository for spent nuclear fuels, and is written for both experts in the various fields involved, decision-makers and the interested general public. The review can not comprise all detailed factors necessary for deciding the localization, but deals mainly with conditions on the land surface and can point out areas which are not well suited or less interesting as a site. It also treats several scientific, technical and social bases in different parts of the country. 120 refs, 53 figs

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

    International Nuclear Information System (INIS)

    Stephansson, Ove

    2000-01-01

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

  9. Attitudes towards a final repository for the spent nuclear fuel. Structure and causes

    International Nuclear Information System (INIS)

    Sjoeberg, Lennart

    2008-09-01

    This report presents the results of a questionnaire survey of attitudes towards a final repository for the spent nuclear fuel. The questionnaire was mailed to 3,000 persons. Participants were young and older people in Oskarshamn municipality and Oesthammar municipality as well as in the rest of the country. Fifty-one percent responded. The questionnaire included a large number of questions of possible relevance for understanding the structure of and reasons for the person's attitude towards a final repository. Questions concerning nuclear power were dealt with in a special section. Men were more positively disposed towards a repository than women, older people more than young. The gender differences are mainly attributable to the variation in attitude towards nuclear power and concern about nuclear accidents. In the case of older people, interest was also a factor. Young people were not as interested in the issue. The most important factor in determining the attitude towards a final repository was the benefit it was expected to bring to the municipality. Moral and emotional aspects were also important. Risk played a relatively subordinate role. Social aspects were very important: those who frequently spoke with people who were positively disposed tended to be positive themselves, and vice versa for those who were negative. This factor could explain some of the gender differences in attitude. Attitudes in Oskarshamn were slightly more positive than in Oesthammar, probably due to the fact that the residents in Oskarshamn had a greater sense of participation in the municipality's decision in the matter. Information from SKB was also found to be an important factor for the differences in attitude between the municipalities. Eight percentage points more people had received information in Oskarshamn than in Oesthammar. The difference may be small, but it exists and does appear to be of some importance. Attitudes in Oskarshamn and Oesthammar continued to be much more

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-12-01

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

  11. SSM's licensing review of a spent nuclear fuel repository in Sweden

    International Nuclear Information System (INIS)

    Dverstorpand, Bjoern; Stroemberg, Bo

    2014-01-01

    On 16 March 2011 the Swedish Nuclear Fuel and Waste Management Co. (SKB) submitted license applications for a general license to construct, possess and operate a KBS-3 type spent nuclear fuel repository at the Forsmark site, in Oesthammar municipality, and an encapsulation plant in Oskarshamn municipality. The KBS-3 method, which has been developed by SKB over a period of more than 30 years, entails disposing of the spent fuel in copper canisters, surrounded by a swelling bentonite clay, at about 500 m depth in crystalline basement rock. SKB's applications are being evaluated in parallel by the Swedish Radiation Safety Authority (SSM) according to the Act on Nuclear Activities and by the Land and Environmental Court according to the Environmental Code. During the review SSM will act as an expert review body to the Land and Environmental Court in the areas of radiation protection, safety and security/non-proliferation. Both SSM and the court will produce a statement with a recommendation regarding a licensing decision and licensing conditions to the government. The government will make the final decision after consulting the municipalities concerned by SKB's facilities (municipal veto applies). The current licensing decision is just one of several licensing decisions that will be required for the repository. However it is arguably the most important one, because it is the last licensing stage with a broad societal involvement including an environmental impact assessment (EIA) process, national consultations and municipal veto for the concerned municipalities. The licensing steps to follow, should SKB be granted a license by the government, only require approval by SSM. These steps include application for start of actual construction work, test operation and routine operation. (authors)

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

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, A. [ed.

    1999-11-01

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

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

    International Nuclear Information System (INIS)

    Westerlind, Magnus

    2003-01-01

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

  14. Tourism and visiting activities in Tierp. Threats and possibilities with a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Bjoerne, S.; Sandberg, M.; Sahlberg, B.

    1999-10-01

    Consequences for tourism and visiting at Tierp from siting a spent fuel repository in the community are studied. Tierp has little tourism as of today, and siting of the repository will probably lead to increased visiting of Tierp professionally and as a leisure activity

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2002-04-01

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

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

    International Nuclear Information System (INIS)

    Pettersson, Stig; Forsgren, Ebbe; Lange, Fritz

    2002-04-01

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

  17. Final repository for spent nuclear fuel - the role of the municipality

    International Nuclear Information System (INIS)

    Berggren, Marie; Lindfors, Virpi; Andersson Oehrn, Barbro; Alm, Bertil; Soederblom, Anna-Lena; Berggren, Marie; Lindfors, Virpi

    2014-01-01

    In Sweden there is a long tradition of local self-government which is enshrined within the Swedish constitution, and the municipalities are responsible for matters relating to its inhabitants and their immediate environment. The municipality of Oesthammar has been engaged in the project of final repository for spent nuclear fuel since 1995 and by that time a consultative committee was established with representatives from all the political parties within the municipality and neighbouring municipalities. Future potentials as well as threats must be considered when making decisions on the most favourable site and the method used for the disposal of nuclear waste, and the application from SKB, as well as the review by the authorities, must stand up to a number of public demands. The work has included several stages of decisions for the municipality, due to the site selection process for SKB. The dialogue between the municipality and SKB as well as between the municipality and the authorities has been of great importance for getting the stepwise decision making process that has become practice in this question. The municipality has intensively followed the process concerning establishment of a final repository through consultation meetings, by being observer on meetings between SKB and Swedish Radiation Safety Authority (SSM), seminars, statements, etc. The openness and transparency throughout the process has been essential between all actors. However, if the municipalities have a right of absolute veto, the government still can say yes even if the municipality has said no

  18. Psycho-social effects of a repository for spent nuclear fuels. Literature review and interviews with inhabitants of Uppsala

    International Nuclear Information System (INIS)

    Brostroem, L.; Kessling, A.; Kraft, G.; Sjoeberg, L.

    2002-01-01

    This report is a complement to the studies of the communities of Tierp, Aelvkarleby and Oesthammar as candidates for localization of a repository for spent nuclear fuels. In the first part, a study is presented of published literature in the area of psycho-social effects of building large-scale plants. In the second part interviews are reported with people living in, or with other connections with, Uppsala, of their reactions on a location of the repository in the northern part of the county of Uppland and how they believe the repository would affect the local population, the tourism and local economy

  19. Site selection for Canada's national repository for used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-12-15

    In 2007, the Government of Canada selected Adaptive Phased Management as Canada's plan for the long-term management of Canada's used nuclear fuel. The approach provides for containment and isolation of the material in a deep geological repository at a safe site with an informed and willing host. The Nuclear Waste Management Organization is tasked through federal legislation with selecting the site and developing and managing all aspects of the plan. In May 2010, the organization published and initiated the site selection process that serves as a road map for decision making on the location for the deep geological repository. It continues to lead the site selection process for the repository and an associated Centre of Expertise. The screening process is advancing and, from an initial starting point of 22 communities expressing interest in learning about the project; as of September 2015, 9 communities are the focus of more detailed technical and community well-being studies. Preliminary Assessments, the third step in the 9-step site selection process are underway in these communities. The Assessments involve preliminary technical and social desktop and field assessments, engagement activities within and beyond each interested community, and involvement of Indigenous peoples and nearby municipalities in the planning and conduct of the work. This paper provides an update on the advancement of the site selection process. It describes the nature of the technical and social studies being conducted at this phase of work, including the progressively more detailed field studies that are the focus of technical work at the current stage, the approach to engagement and collaboration with communities to direct these studies, and the work underway to ensure the framework used for this assessment and engagement includes the range of priorities and perspectives of First Nations and Metis peoples and communities in the broader area. (author)

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

    International Nuclear Information System (INIS)

    2000-01-01

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

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

    International Nuclear Information System (INIS)

    Hedin, A.; Kautsky, U.

    2000-03-01

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

  2. Threats and benefits updated information on local opinions regarding the spent nuclear fuel repository in Finland - 16128

    International Nuclear Information System (INIS)

    Kojo, Matti; Kari, Mika; Litmanen, Tapio

    2009-01-01

    The aim of the paper is to provide updated information on local opinion regarding the siting of a spent nuclear fuel repository in Finland. The main question is how the residents of the municipality perceive the threats and benefits of the repository. In accordance with the Decision in Principle by the Council of State passed in 2000, the Olkiluoto area in Municipality of Eurajoki was chosen as the location for the repository to accommodate spent nuclear fuel produced in Finland. Updated information on local opinions is needed as the siting process is approaching the next phase, the application for a construction license by 2012. The nuclear waste management company Posiva, owned by the utilities Teollisuuden Voima and Fortum Power and Heat, has also applied for a new Decision in Principle (DiP) for expansion of the repository. The data provided in this paper is based on a survey carried out in June 2008. The respondents were selected from the residents of the municipality of Eurajoki and the neighbouring municipalities using stratified random sampling (N=3000). The response rate of the survey was 20% (N=606). The paper is part of a joint research project between the University of Jyvaeskylae and the University of Tampere. The research project 'Follow-up research regarding socio-economic effects and communication of final disposal facility of spent nuclear fuel in Eurajoki and its neighbouring municipalities' is funded by the Finnish Research Programme on Nuclear Waste Management (KYT2010). (authors)

  3. Preservation of information about the repository for spent nuclear fuels - proposal for action plan

    International Nuclear Information System (INIS)

    Bowen-Schrire, Monica; Eckerhall, Daniel; Jander, Hans; Waniewska, Katarina

    2008-10-01

    This report is a proposal for an action plan with the ultimate aim of ensuring that information about the repository for spent nuclear fuel can be preserved and transferred for future generations. The purpose of the proposal for an action plan is to present ideas on tangible measures and guidelines for information preservation and transfer, in the short and long term. The report deals with a number of aspects relating to information preservation as well as risks that can lead to the loss of important information. The proposal for an action plan is based on reasoning about these subjects. The main emphasis is on measures that need to be implemented in the near future to ensure that successive and direct information transfer is handled in a suitable manner. It is suggested that the following measures should be implemented within a five-year period: - Designate a person responsible for information preservation. - Work out guidelines for information preservation and transfer. - Form a network with other organizations in Sweden. - Initiate a dialogue with other countries, especially USA and France. - Participate in seminars, conferences and workgroups on an international level within the IAEA and NEA. In a longer time perspective the following measures should also be implemented: - Implement guidelines for information preservation and transfer. - Document the archiving system. - Establish a communication plan. - Archive information about the repository. - Keep the action plan up to date

  4. Landscape modeling for dose calculations in the safety assessment of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Lindborg, Tobias; Kautsky, Ulrik; Brydsten, Lars

    2007-01-01

    The Swedish Nuclear Fuel and Waste Management Co.,(SKB), pursues site investigations for the final repository for spent nuclear fuel at two sites in the south eastern part of Sweden, the Forsmark- and the Laxemar site. Data from the two site investigations are used to build site descriptive models of the areas. These models describe the bedrock and surface system properties important for designing the repository, the environmental impact assessment, and the long-term safety, i.e. up to 100,000 years, in a safety assessment. In this paper we discuss the methodology, and the interim results for, the landscape model, used in the safety assessment to populate the Forsmark site in the numerical dose models. The landscape model is built upon ecosystem types, e.g. a lake or a mire, (Biosphere Objects) that are connected in the landscape via surface hydrology. Each of the objects have a unique set of properties derived from the site description. The objects are identified by flow transport modeling, giving discharge points at the surface for all possible flow paths from the hypothetical repository in the bedrock. The landscape development is followed through time by using long-term processes e.g. shoreline displacement and sedimentation. The final landscape model consists of a number of maps for each chosen time period and a table of properties that describe the individual objects which constitutes the landscape. The results show a landscape that change over time during 20,000 years. The time period used in the model equals the present interglacial and can be used as an analogue for a future interglacial. Historically, the model area was covered by sea, and then gradually changes into a coastal area and, in the future, into a terrestrial inland landscape. Different ecosystem types are present during the landscape development, e.g. sea, lakes, agricultural areas, forest and wetlands (mire). The biosphere objects may switch from one ecosystem type to another during the

  5. Integrated Analytic Radionuclide Transport Model for a Spent Nuclear Fuel Repository in Saturated Fractured Rock

    International Nuclear Information System (INIS)

    Hedin, Allan

    2002-01-01

    Simple analytic expressions are presented for radionuclide transport from a KBS 3-type repository, where spent nuclear fuel is placed in copper canisters surrounded by bentonite clay and deposited at a depth of 500 m in fractured granitic rock.Dissolution of readily accessible and fuel matrix embedded nuclides, chain decay, and nuclide precipitation is treated within the canister. Transport in the canister void and buffer is modeled with a dual stirred tank analogy, where transport resistances represent an assumed small initial damage in the canister and transport features of the buffer-geosphere interface. Initial, transient diffusion in the buffer is treated with a simple correction term. Chain decay is not included in the buffer.Geosphere transport expressions handle advection, longitudinal dispersion, matrix diffusion, sorption, and radioactive decay, but not chain decay. The treatment is based on earlier results for an instantaneous inlet and for a constant inlet to the geosphere in the nondispersive case. A correction is added so that longitudinal dispersion is taken approximately into account. The correction utilizes analytical expressions for the temporal moments of the geosphere release curve in the dispersive case.The near-field/geosphere integration is treated in a simplified manner avoiding numerical convolutions. The instantaneous inlet expression for the geosphere release is used when the near-field release decreases rapidly in comparison to a typical response time in the geosphere; the constant inlet expression is used in the opposite case.Twenty-seven calculation cases from a safety assessment of a KBS 3 repository using borehole data from three different field investigation sites were repeated with the analytic expressions. The agreement in both near-field and geosphere releases is in general well within an order of magnitude for the variety of long- and short-lived, sorbing, nonsorbing, solubility limited, immediately accessible, and fuel matrix

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  7. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Evolution report

    International Nuclear Information System (INIS)

    Smith, P.; Johnson, L.; Snellman, M.; Pastina, B.; Gribi, P.

    2007-12-01

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 method. Posiva and SKB have conducted a joint research, demonstration and development (RD and D) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007, have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is pre-packaged in a perforated steel cylinder prior to emplacement in the deposition drift; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100 - 300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the repository evolution in successive time frames, including key uncertainties. The description of evolution starts with the initial conditions at the time of emplacement of the first canisters. The repository evolves through an early, transient phase to a state where evolution is far slower. Particular attention is given to describing the transient phase, since this is where most of the

  8. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Evolution report

    International Nuclear Information System (INIS)

    Smith, Paul; Johnson, Lawrence; Snellman, Margit; Pastina, Barbara; Gribi, Peter

    2008-01-01

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007, have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is pre-packaged in a perforated steel cylinder prior to emplacement in the deposition drift; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the repository evolution in successive time frames, including key uncertainties. The description of evolution starts with the initial conditions at the time of emplacement of the first canisters. The repository evolves through an early, transient phase to a state where evolution is far slower. Particular attention is given to describing the transient phase, since this is where most of the

  9. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Evolution report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul; Johnson, Lawrence; Snellman, Margit; Pastina, Barbara; Gribi, Peter

    2008-01-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007, have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is pre-packaged in a perforated steel cylinder prior to emplacement in the deposition drift; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the repository evolution in successive time frames, including key uncertainties. The description of evolution starts with the initial conditions at the time of emplacement of the first canisters. The repository evolves through an early, transient phase to a state where evolution is far slower. Particular attention is given to describing the transient phase, since this is where most of the

  10. Site selection - location of the repository for spent nuclear fuel; Platsval - lokalisering av slutfoervaret foer anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    2010-12-15

    This document describes the localization work and SKB's choice of site for the repository. Furthermore, SKB's basis and rationale for the decisions taken during the work are reported. The document is Appendix PV of applications under the Nuclear Activities Act and the Environmental Code to both build and operate an encapsulation plant adjacent to the central interim storage facility for spent nuclear fuel in Oskarshamn, and to construct and operate a disposal facility for spent nuclear fuel at Forsmark in Oesthammar municipality

  11. Nuclear Waste Risk Perceptions and Attitudes in Siting a Final Repository for Spent Nuclear Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, Lennart [Stockholm School of Economics (Sweden). Center for Risk Research

    2006-09-15

    The paper does the following: Describes the time trends between 2001 and 2005 in terms of policy intention, perceived risk, trust and attitude Analyzes the relationships between policy attitude - the major dependent variable - and the explanatory variables of perceived risk, trust and attitude. Determines whether policy attitude variation across time, municipalities and genders can be accounted for by variation in perceived risk, trust and attitude. Random samples of 2000 persons living in Oesthammar and Oskarshamn were approached with a mailed questionnaire in 2005 (as was done in 2005). After two reminders, 888 had returned filled out questionnaires, yielding a total response rate of 50 percent, taking into account that some persons had moved without giving a forwarding address to the post office, and that some were unable to answer due to illness or old age. (1). There was a substantially more positive attitude to a local SNF repository in 2005 than in 2001, after an intervening period of phase 2 site investigation. This was true for men and women, both municipalities and with all the response measures analyzed. Men were more positive than women, and had developed more strongly in the positive direction than women had. The attitude in Oskarshamn was somewhat more positive than in Oesthammar. (2). Policy intention was well accounted for by the explanatory variables used here, close to 64 percent of the variance. The most important explanatory variables were epistemic trust, attitude to the repository and social trust, in that order. The differences among these three variables were small with regard to explanatory power. (3) Variation in policy attitude across time, municipalities and gender was reduced in an analysis of covariance with risk, trust and attitude as controlling factors. Hence, these factors explain a large fraction of the variation in policy attitude as observed here. Yet, the time trend was not fully explained and gender variability remained to

  12. Nuclear Waste Risk Perceptions and Attitudes in Siting a Final Repository for Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Sjoeberg, Lennart

    2006-01-01

    The paper does the following: Describes the time trends between 2001 and 2005 in terms of policy intention, perceived risk, trust and attitude Analyzes the relationships between policy attitude - the major dependent variable - and the explanatory variables of perceived risk, trust and attitude. Determines whether policy attitude variation across time, municipalities and genders can be accounted for by variation in perceived risk, trust and attitude. Random samples of 2000 persons living in Oesthammar and Oskarshamn were approached with a mailed questionnaire in 2005 (as was done in 2005). After two reminders, 888 had returned filled out questionnaires, yielding a total response rate of 50 percent, taking into account that some persons had moved without giving a forwarding address to the post office, and that some were unable to answer due to illness or old age. (1). There was a substantially more positive attitude to a local SNF repository in 2005 than in 2001, after an intervening period of phase 2 site investigation. This was true for men and women, both municipalities and with all the response measures analyzed. Men were more positive than women, and had developed more strongly in the positive direction than women had. The attitude in Oskarshamn was somewhat more positive than in Oesthammar. (2). Policy intention was well accounted for by the explanatory variables used here, close to 64 percent of the variance. The most important explanatory variables were epistemic trust, attitude to the repository and social trust, in that order. The differences among these three variables were small with regard to explanatory power. (3) Variation in policy attitude across time, municipalities and gender was reduced in an analysis of covariance with risk, trust and attitude as controlling factors. Hence, these factors explain a large fraction of the variation in policy attitude as observed here. Yet, the time trend was not fully explained and gender variability remained to

  13. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Summary report

    International Nuclear Information System (INIS)

    Smith, Paul; Neall, Fiona; Snellman, Margit; Pastina, Barbara; Nordman, Henrik; Johnson, Lawrence; Hjerpe, Thomas

    2008-03-01

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific RandD and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic 'difference analysis' of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the event of

  14. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    Smith, Paul; Neall, Fiona; Snellman, Margit; Pastina, Barbara; Nordman, Henrik; Johnson, Lawrence; Hjerpe, Thomas

    2008-03-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific RandD and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic 'difference analysis' of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the

  15. Safety Assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto

    International Nuclear Information System (INIS)

    Smith, P.; Neall, F.; Snellman, M.; Pastina, B.; Hjerpe, T.; Nordman, H.; Johnson, L.

    2007-12-01

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RD and D) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. This safety assessment is summarised in the present report. The scientific basis of the safety assessment includes around 30 years of scientific R and D and technical development in the Swedish and Finnish KBS-3V programmes. Much of this scientific basis is directly applicable to KBS-3H. This has allowed the KBS-3H safety studies to focus on those issues that are unique to this design alternative, identified in a systematic difference analysis of KBS-3H and KBS-3V. This difference analysis has shown that the key differences in the evolution and performance of KBS-3H and KBS-3V relate mainly to the engineered barrier system and to the impact of local variations in the rate of groundwater inflow on buffer saturation along the KBS-3H deposition drifts. No features or processes specific to KBS-3H have been identified that could lead to a loss or substantial degradation of the safety functions of the engineered barriers over a million year time frame. Radionuclide release from the repository near field in the event of

  16. Independent modelling in SSM's licensing review of a spent nuclear fuel repository

    International Nuclear Information System (INIS)

    Xu, Shulan; Dverstorp, Bjoern; Norden, Maria

    2014-01-01

    In 2011 the Swedish Nuclear Fuel and Waste Management Co. (SKB) submitted a license application for construction of a geological repository for spent nuclear fuel at Forsmark. SKB's disposal method, the KBS-3 method, involves disposing of the spent nuclear fuel in cast iron canisters with an outer layer of 5 cm copper. The canisters will be placed in vertical deposition holes at approximately 500 m depths in crystalline bedrock. Each canister is surrounded by a buffer of swelling bentonite clay. The repository is designed to accommodate 6 000 canisters, corresponding to 12 000 tonnes of spent nuclear fuel. The license application is supported by a post-closure safety assessment, SR-Site. Along with other parts of the application, SR-Site is currently being reviewed by the Swedish Radiation Safety Authority (SSM). The main method for review of SKB's licensing documentation is document review carried out by SSM, supported by SSM's external experts. However, SSM's document review is also supported by regulatory modelling, technical reviews of SKB's quality assurance programme and consideration of external review comments partly from two broad national consultations and an international peer review organised by the OECD's Nuclear Energy Agency (NEA, 2012). SSM's review is divided into three main phases: the initial review phase, the main review phase and the reporting phase. The overall goal of the initial review phase is to achieve a broad coverage of SR-Site and its supporting references and in particular to identify the need for complementary information and clarifications to be provided by SKB, as well as to identify critical review issues that require a more comprehensive treatment in the main review phase. SSM completed the initial review phase at the end of 2012. During the initial review phase SSM has identified a number of issues requiring either clarifications, complementary information from SKB or further in-depth review by SSM. Important issues include the

  17. 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

  18. Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository - Volume 3: Appendices

    International Nuclear Information System (INIS)

    Taylor, L.L.; Wilson, J.R.; Sanchez, L.C.; Aguilar, R.; Trellue, H.R.; Cochrane, K.; Rath, J.S.

    1998-01-01

    The United States Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3)

  19. Multiphase flow in the geosphere around a repository for spent nuclear fuels. Inventory of the present knowledge

    International Nuclear Information System (INIS)

    Aalen, Bengt

    2004-10-01

    Important quantities of gas can form in an underground repository for nuclear wastes. Gas can be formed through: corroding metals; water and certain organic substances that undergo radiolysis; organic material degrading through microbial activity. The last point is of concern mainly for intermediate-level wastes, which can hold large amounts of organic materials. The first point is the main process for high-level wastes. The gas could transport radioactive substances through the buffer and the geosphere into the biosphere, or affect the performance of the repository in a negative way. The present report gives a review of the knowledge about two-phase flow in connection with deep geologic repositories for spent nuclear fuel

  20. Possibility of multiple temperature maxima in geologic repositories for spent fuel from nuclear reactors

    International Nuclear Information System (INIS)

    Beyerlein, S.W.; Claiborne, H.C.

    1980-01-01

    Heat transfer studies show that two temperature maxima at the disposal horizon could be experienced in CANDU spent fuel repositories - one at about 60 years and another slightly higher one at 13,000 years. Because CANDU spent fuels display a monotonically decreasing heat generation rate, it is not immediately obvious why this behavior should occur. This report investigates this behavior, confirms the Canadian results, demonstrates that the double peak phenomenon is due to the presence of the right mixture of short- and long-lived nuclides in the fuel, and concludes that the 13,000-year maximum is largely an artifact of the infinite or very large plane source model. When more realistic repository geometries are used, the second peak disappears for repository sizes less than about 1 km 2 . Over the long term, radial and surface heat transfer causes the thermal history of the disposal region to deviate from that predicted by infinite plane (or large finite) source models by reducing the magnitude of the second peak. Beyond a 1000-year time horizon, care should be exercised in modeling spent fuel repositories to include the proper boundary conditions. For the first few centuries after emplacement, however, the infinite source model is consistent with the finite disk source model as well as with arrays of spherical and point sources. The second temperature peak can be avoided by restricting the size of the repository and/or partitioning out the long-lived components of the fuel. When spent fuel from PWRs was examined for multiple temperature maxima, only one peak was found, even for the infinite plane source model

  1. SKI's engagement in the process for siting a spent nuclear fuel repository

    Energy Technology Data Exchange (ETDEWEB)

    Paeivioe Jonsson, Josefin; Westerlind, Magnus [Swedish Nuclear Power Inspectorate, Stockholm (Sweden)

    2006-09-15

    preferred location for the encapsulation plant for spent nuclear fuel was in the municipality of Oskarshamn (in connection to the central interim storage for spent nuclear fuel, CLAB). This led the municipality to initiate a forum for consultations between the municipality, County Administration Board, SKI and SSI (the so-called MKB-Forum in Kalmar County). They emphasised that active regulators, with clear roles and positions, were a prerequisite for the municipality's involvement in the siting process. In 1996 a feasibility study for a repository was launched by SKB and was included in the MKB-Forum's work. SKI's RandD in the field of nuclear waste management aims at maintaining and developing the competence needed for independent assessments of safety. In recent years the research also includes risk communication and decision-making processes. The co-ordination of EIA and decision making processes according to different acts, in particular the Act on Nuclear Activities and the Environmental Code is one big challenge for all actors involved in process for siting a repository for spent nuclear fuel. Many actors will be involved in the parallel licensing process and it requires good planning and good cooperation. The application for construction of an encapsulation plant will be submitted already in 2006 (addressing mainly technical basis and operational safety), but will be updated in 2008 (e.g. coverage of long-term safety for the sealed waste canisters produced in the plant). These applications must be approved according to the Environmental Code and the Act of Nuclear Activities before construction licenses can be given. A final decision from the Swedish Government will most probably address the whole concept of disposal, simultaneously covering both facilities. With an estimated period covering at least two years for technical review by SKI, SSI and the Swedish Environmental Court (for approval according to Environmental Code) and at least one year for

  2. The Economic, repository and proliferation implications of advanced nuclear fuel cycles

    International Nuclear Information System (INIS)

    Deinert, Mark; Cady, K.B.

    2011-01-01

    The goal of this project was to compare the effects of recycling actinides using fast burner reactors, with recycle that would be done using inert matrix fuel burned in conventional light water reactors. In the fast reactor option, actinides from both spent light water and fast reactor fuel would be recycled. In the inert matrix fuel option, actinides from spent light water fuel would be recycled, but the spent inert matrix fuel would not be reprocessed. The comparison was done over a limited 100-year time horizon. The economic, repository and proliferation implications of these options all hinge on the composition of isotopic byproducts of power production. We took the perspective that back-end economics would be affected by the cost of spent fuel reprocessing (whether conventional uranium dioxide fuel, or fast reactor fuel), fuel manufacture, and ultimate disposal of high level waste in a Yucca Mountain like geological repository. Central to understanding these costs was determining the overall amount of reprocessing needed to implement a fast burner, or inert matrix fuel, recycle program. The total quantity of high level waste requiring geological disposal (along with its thermal output), and the cost of reprocessing were also analyzed. A major advantage of the inert matrix fuel option is that it could in principle be implemented using the existing fleet of commercial power reactors. A central finding of this project was that recycling actinides using an inert matrix fuel could achieve reductions in overall actinide production that are nearly very close to those that could be achieved by recycling the actinides using a fast burner reactor.

  3. 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

  4. Preliminary plan for decommissioning - repository for spent nuclear fuel; Preliminaer plan foer avveckling - slutfoervar foer anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    Hallberg, Bengt; Tiberg, Liselotte (Studsvik Nuclear AB, Nykoeping (Sweden))

    2010-06-15

    The final disposal facility for spent nuclear fuel is part of the KBS-3 system, which also consists of a central facility for interim storage and encapsulation of the spent nuclear fuel and a transport system. The nuclear fuel repository will be a nuclear facility. Regulation SSMFS 2008:1 (Swedish Radiation Safety Authority's regulations on safety of nuclear facilities) requires that the licensee must have a current decommissioning plan throughout the facility lifecycle. Before the facility is constructed, a preliminary decommissioning plan should be reported to the Swedish Radiation Safety Authority. This document is a preliminary decommissioning plan, and submitted as an attachment to SKB's application for a license under the Nuclear Activities Act to construct, own and operate the facility. The final disposal facility for spent nuclear fuel consists of an above ground part and a below ground part and will be built near Forsmark and the final repository for radioactive operational waste, SFR. The parts above and below ground are connected by a ramp and several shafts, e.g. for ventilation. The below ground part consists of a central area, and several landfill sites. The latter form the repository area. The sealed below ground part constitutes the final repository. The decommissioning is taking place after the main operation has ended, that is, when all spent nuclear fuel has been deposited and the deposition tunnels have been backfilled and plugged. The decommissioning involves sealing of the remaining parts of the below ground part and demolition of above ground part. When decommissioning begins, there will be no contamination in the facility. The demolition is therefore performed as for a conventional plant. Demolition waste is sorted and recycled whenever possible or placed in landfill. Hazardous waste is managed in accordance with current regulations. A ground investigation is performed and is the basis for after-treatment of the site. The timetable

  5. Rock quality designation of the hydraulic properties in the near field of a final repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Carlsson, Hans; Carlsson, Leif; Pusch, Roland

    1989-06-01

    Quality assurance of a final repository for spent nuclear fuel requires detailed information on the characteristics of the rock, backfill, canisters and the waste itself. Furthermore, and of fundamental importance, is the knowledge of the behaviour of the integrated system of the waste and the different barriers. The in-situ characteristics of the rock must therefore be assessed and their influence on and interactions with the remaining barriers must be predicted and verified. A rock quality designation process of the hydraulic properties in the near-field is out-lined both for the KBS-3 system as well as for the WP-cave system. The process, once updated and approved, will be included in a Quality Assurance Program for the final repository for spent nuclear fuel. Some of the available methods for the near-field designation process are presented as well as techniques that need further development or are not developed at all. Finally, a presentation is given of a generic designation process of the KBS-3 and WP-cave repository systems in the previously investigated area in Central Sweden, where the final repository for reactor waste, SFR, is located. Geological and hydrogeological data are here at hand and it is therefore possible to carry out a simulation of how the designation process would be accomplished. (authors) (72 figs., 12 tabs., 43 refs.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2013-07-01

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

  7. SR-CAN - a safety assessment of a repository of spent nuclear fuel: canister performance and effects on the biosphere

    International Nuclear Information System (INIS)

    Kautsky, U.; Kumblad, L.

    2004-01-01

    During the next few years the Swedish Nuclear Fuel and Waste Management Co. (SKB) performs site investigations at two sites in Sweden for a future repository of spent nuclear fuel. Parallel an encapsulation plant is planned to encapsulate the spent fuel in copper canisters according to the KBS-3 method. The purpose of the SR-CAN safety assessment is to show the performance of the canister isolations at different sites for a repository at 500 meters depth in crystalline rock. Moreover, SR-CAN provides an example how the site specific safety assessment of a deep repository will be made in year 2006-2008. To be able to calculate dose and risk for humans and the environment, new assessment methods were developed for the biosphere. These methods were based on a system ecological approach and used knowledge from landscape ecology to provide an integrated approach with hydrology and geology considering the discharges in a watershed and calculating consequences in terrestrial and aquatic (freshwater and marine) ecosystems. A range of methods and tools were developed in GIS and Matlab/Simulink to be able to model and understand the important processes in the landscape today and during the next few thousands of years. In this paper, an overview of the program and the novel methods are presented, as well as some examples from performance calculations from a watershed in the Forsmark area considering effects on humans and ecosystems. (author)

  8. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Process report

    International Nuclear Information System (INIS)

    Gribi, Peter; Johnson, Lawrence; Suter, Daniel; Smith, Paul; Pastina, Barbara; Snellman, Margit

    2008-01-01

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is placed in a perforated steel cylinder prior to emplacement; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the main processes potentially affecting the long-term safety of the system, covering radiation-related, thermal, hydraulic, mechanical, chemical (including microbiological) and radionuclide transport-related processes. The process descriptions deal sequentially with the main sub-systems: fuel/cavity in canister, cast iron insert and copper canister, buffer and other bentonite components, supercontainer

  9. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Process report

    Energy Technology Data Exchange (ETDEWEB)

    Gribi, Peter; Johnson, Lawrence; Suter, Daniel; Smith, Paul; Pastina, Barbara; Snellman, Margit

    2008-01-15

    The KBS-3 method, based on multiple barriers, is the proposed spent fuel disposal method both in Sweden and Finland. KBS-3H and KBS-3V are the two design alternatives of the KBS-3 spent fuel disposal method. Posiva and SKB have conducted a joint research, demonstration and development (RDandD) programme in 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to the reference alternative KBS-3V. The overall objectives of the present phase covering the period 2004-2007 have been to demonstrate that the horizontal deposition alternative is technically feasible and to demonstrate that it fulfils the same long-term safety requirements as KBS-3V. The safety studies conducted as part of this programme include a safety assessment of a preliminary design of a KBS-3H repository for spent nuclear fuel located about 400 m underground at the Olkiluoto site, which is the proposed site for a spent fuel repository in Finland. In the KBS-3H design alternative, each canister, with a surrounding layer of bentonite clay, is placed in a perforated steel cylinder prior to emplacement; the entire assembly is called the supercontainer. Several supercontainers are positioned along parallel, 100-300 m long deposition drifts, which are sealed following waste emplacement using drift end plugs. Bentonite distance blocks separate the supercontainers, one from another, along the drift. Steel compartment plugs can be used to seal off drift sections with higher inflow, thus isolating the different compartments within the drift. The present report describes the main processes potentially affecting the long-term safety of the system, covering radiation-related, thermal, hydraulic, mechanical, chemical (including microbiological) and radionuclide transport-related processes. The process descriptions deal sequentially with the main sub-systems: fuel/cavity in canister, cast iron insert and copper canister, buffer and other bentonite components, supercontainer

  10. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Complementary evaluations of safety

    International Nuclear Information System (INIS)

    Neall, Fiona; Pastina, Barbara; Snellman, Margit; Smith, Paul; Gribi, P.; Johnson, Lawrence

    2008-12-01

    The KBS-3H design is a variant of the more general KBS-3 method for the geological disposal of spent nuclear fuel in Finland and Sweden. In the KBS-3H design, multiple assemblies containing spent fuel are emplaced horizontally in parallel, approximately 300 m long, slightly inclined deposition drifts. The copper canisters, each with a surrounding layer of bentonite clay, are placed in perforated steel shells prior to deposition in the drifts; the assembly is called the 'supercontainer'. The other KBS-3 variant is the KBS-3V design, in which the copper canisters are emplaced vertically in individual deposition holes surrounded by bentonite clay but without steel supercontainer shells. SKB and Posiva have conducted a Research, Development and Demonstration programme over the period 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to KBS-3V. As part of this programme, the long-term safety of a KBS-3H repository has been assessed in the KBS-3H safety studies. In order to focus the safety studies, the Olkiluoto site in the municipality of Eurajoki, which is the proposed site for a spent fuel repository in Finland, was used as a hypothetical site for a KBS-3H repository. The present report is part of a portfolio of reports discussing the long-term safety of the KBS-3H repository. The overall outcome of the KBS-3H safety studies is documented in the summary report, 'Safety assessment for a KBS-3H repository for spent nuclear fuel at Olkiluoto'. The purpose and scope of the KBS-3H complementary evaluations of safety report is provided in Posiva's Safety Case Plan, which is based on Regulatory Guide YVL 8.4 and on international guidelines on complementary lines of argument to long-term safety that are considered an important element of a post-closure safety case for geological repositories. Complementary evaluations of safety require the use of evaluations, evidence and qualitative supporting arguments that lie outside the

  11. Safety assessment for a KBS-3H spent nuclear fuel repository at Olkiluoto. Complementary evaluations of safety

    Energy Technology Data Exchange (ETDEWEB)

    Neall, Fiona; Pastina, Barbara; Snellman, Margit; Smith, Paul; Gribi, P.; Johnson, Lawrence

    2008-12-15

    The KBS-3H design is a variant of the more general KBS-3 method for the geological disposal of spent nuclear fuel in Finland and Sweden. In the KBS-3H design, multiple assemblies containing spent fuel are emplaced horizontally in parallel, approximately 300 m long, slightly inclined deposition drifts. The copper canisters, each with a surrounding layer of bentonite clay, are placed in perforated steel shells prior to deposition in the drifts; the assembly is called the 'supercontainer'. The other KBS-3 variant is the KBS-3V design, in which the copper canisters are emplaced vertically in individual deposition holes surrounded by bentonite clay but without steel supercontainer shells. SKB and Posiva have conducted a Research, Development and Demonstration programme over the period 2002-2007 with the overall aim of establishing whether KBS-3H represents a feasible alternative to KBS-3V. As part of this programme, the long-term safety of a KBS-3H repository has been assessed in the KBS-3H safety studies. In order to focus the safety studies, the Olkiluoto site in the municipality of Eurajoki, which is the proposed site for a spent fuel repository in Finland, was used as a hypothetical site for a KBS-3H repository. The present report is part of a portfolio of reports discussing the long-term safety of the KBS-3H repository. The overall outcome of the KBS-3H safety studies is documented in the summary report, 'Safety assessment for a KBS-3H repository for spent nuclear fuel at Olkiluoto'. The purpose and scope of the KBS-3H complementary evaluations of safety report is provided in Posiva's Safety Case Plan, which is based on Regulatory Guide YVL 8.4 and on international guidelines on complementary lines of argument to long-term safety that are considered an important element of a post-closure safety case for geological repositories. Complementary evaluations of safety require the use of evaluations, evidence and qualitative supporting arguments

  12. The Analytical Repository Source-Term (AREST) model: Analysis of spent fuel as a nuclear waste form

    International Nuclear Information System (INIS)

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

    1989-02-01

    The purpose of this report is to assess the performance of spent fuel as a final waste form. The release of radionuclides from spent nuclear fuel has been simulated for the three repository sites that were nominated for site characterization in accordance with the Nuclear Waste Policy Act of 1982. The simulation is based on waste package designs that were presented in the environmental assessments prepared for each site. Five distinct distributions for containment failure have been considered, and the release for nuclides from the UO 2 matrix, gap (including grain boundary), crud/surface layer, and cladding has been calculated with the Analytic Repository Source-Term (AREST) code. Separate scenarios involving incongruent and congruent release from the UO 2 matrix have also been examined using the AREST code. Congruent release is defined here as the condition in which the relative mass release rates of a given nuclide and uranium from the UO 2 matrix are equal to their mass ratios in the matrix. Incongruent release refers to release of a given nuclide from the UO 2 matrix controlled by its own solubility-limiting solid phase. Release of nuclides from other sources within the spent fuel (e.g., cladding, fuel/cladding gap) is evaluated separately from either incongruent or congruent matrix release. 51 refs., 200 figs., 9 tabs

  13. Final repository for spent nuclear fuel. Underground design Forsmark, Layout D1

    International Nuclear Information System (INIS)

    Brantberger, Martin; Zetterqvist, Anders; Arnbjerg-Nielsen, Torben; Olsson, Tommy; Outters, Nils; Syrjaenen, Pauli

    2006-04-01

    This report comprises the design step D1 related to the underground design for a deep repository located at the Forsmark site. The design is based on the Site Descriptive Model Forsmark v1.2. All studies have been focussed at an area southeast of the Forsmark nuclear plant, which has been considered to be the most promising area for hosting the repository. SKB has developed guidelines for the design of the repository, which further describes the methodology applied for the studies. From these guidelines the following basic objectives for the design step D1 are summarized: to determine whether the final repository can be accommodated within the studied site; to identify site-specific facility critical issues; to test and evaluate the design methodology; to provide feedback to: the design organisation regarding additional studies that needs to be done; the site investigation and modelling organization regarding further investigations required; and the safety assessment team. The possible locations for a tentative deep repository are analysed in Chapter 3 of the report. The most promising area for the repository (denoted 'priority site') has been defined by SKB to be located southeast of the Forsmark nuclear plant and northwest of the gently dipping deformation zone ZFMNE00A2. Regarding the repository depth, present knowledge acquired from the site investigations indicates that it is possible to locate the repository at all stipulated depths according to SKB, that is between 400 m and 700 m depth. The preliminary assessment made in Chapter 3 clearly demonstrates that the repository can be accommodated within the 'priority site'. The potential to accommodate the repository is essentially the same for both 400 m and 500 m depths. The design of the deposition areas is reported in Chapter 4, which includes the design of layout features for all tunnels and deposition holes, orientation of tunnels, calculation of anticipated loss of deposition holes due to the applied

  14. Final repository for spent nuclear fuel. Underground design Forsmark, Layout D1

    Energy Technology Data Exchange (ETDEWEB)

    Brantberger, Martin; Zetterqvist, Anders [Ramboell Sweden AB, Stockholm (Sweden); Arnbjerg-Nielsen, Torben [Ramboell Denmark A/S, Virum (Denmark); Olsson, Tommy [IandT Olsson AB, Uppsala (Sweden); Outters, Nils [Golder Associates AB, Uppsala (Sweden); Syrjaenen, Pauli [Gridpoint Oy, Helsinki (Sweden)

    2006-04-15

    This report comprises the design step D1 related to the underground design for a deep repository located at the Forsmark site. The design is based on the Site Descriptive Model Forsmark v1.2. All studies have been focussed at an area southeast of the Forsmark nuclear plant, which has been considered to be the most promising area for hosting the repository. SKB has developed guidelines for the design of the repository, which further describes the methodology applied for the studies. From these guidelines the following basic objectives for the design step D1 are summarized: to determine whether the final repository can be accommodated within the studied site; to identify site-specific facility critical issues; to test and evaluate the design methodology; to provide feedback to: the design organisation regarding additional studies that needs to be done; the site investigation and modelling organization regarding further investigations required; and the safety assessment team. The possible locations for a tentative deep repository are analysed in Chapter 3 of the report. The most promising area for the repository (denoted 'priority site') has been defined by SKB to be located southeast of the Forsmark nuclear plant and northwest of the gently dipping deformation zone ZFMNE00A2. Regarding the repository depth, present knowledge acquired from the site investigations indicates that it is possible to locate the repository at all stipulated depths according to SKB, that is between 400 m and 700 m depth. The preliminary assessment made in Chapter 3 clearly demonstrates that the repository can be accommodated within the 'priority site'. The potential to accommodate the repository is essentially the same for both 400 m and 500 m depths. The design of the deposition areas is reported in Chapter 4, which includes the design of layout features for all tunnels and deposition holes, orientation of tunnels, calculation of anticipated loss of deposition holes due

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

    International Nuclear Information System (INIS)

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

    2010-12-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2010-12-15

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

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

    International Nuclear Information System (INIS)

    Hedin, A.

    1999-11-01

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

  18. Review study 1995. Localization of the repository for spent nuclear fuel; Oeversiktsstudie 95. Lokalisering av djupfoervar foer anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

    This report gives an overview of the studies performed by SKB pertinent to selection of a site for the Swedish repository for spent nuclear fuels, and is written for both experts in the various fields involved, decision-makers and the interested general public. The review can not comprise all detailed factors necessary for deciding the localization, but deals mainly with conditions on the land surface and can point out areas which are not well suited or less interesting as a site. It also treats several scientific, technical and social bases in different parts of the country. 120 refs, 53 figs.

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

    International Nuclear Information System (INIS)

    Facella, J.; Belfadhel, M.B.

    2011-01-01

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

  20. The Site Selected. The Local Decision-Making Regarding the Siting of the Spent Nuclear Fuel Repository in Olkiluoto

    International Nuclear Information System (INIS)

    Kojo, Matti

    2006-01-01

    In May 1999 Posiva, the company responsible for the final disposal of spent nuclear fuel in Finland, suggested that the Finnish Government considers only Olkiluoto in Eurajoki in its application of a decision in principle to be a final disposal site. In January 2000 the municipal council of Eurajoki made a positive statement on the decision in principle. The Government made the decision in principle in Dec 2000, and the Parliament ratified the decision in May 2001. The paper is focused on the decision making of Eurajoki municipality regarding the siting of the spent nuclear fuel repository. The paper shows how the interaction between the representatives of the candidate municipality and the nuclear energy industry was the crucial factor in the decision-making. Eurajoki serves as an example, in where the parties reached an agreement of the compensations for the final disposal repository. The negotiations between the Eurajoki municipality and the nuclear energy industry in reaching a positive decision are analysed from the beginning of the 1980s. The main emphasis is however on the years 1996-99, when the nuclear energy industry negotiated with the municipality on the compensation for the final disposal repository. The loss of income was an important reason why some of the councillors of Eurajoki were interested in having the final disposal repository in Olkiluoto. The industry's problem on the other hand was to safeguard the final disposal site. From the TVO's angle Olkiluoto was a potential final disposal site for example for its limited need for transport and for the existing infrastructure. The company used the financial benefits of the project as its trump card. The attitude of Eurajoki municipality to the final disposal of spent nuclear fuel turned positive with the Olkiluoto vision in December 1998, when still five years earlier the municipal council was prepared to act and prevent the final disposal. The future image presented by the municipality now matched

  1. The Site Selected. The Local Decision-Making Regarding the Siting of the Spent Nuclear Fuel Repository in Olkiluoto

    Energy Technology Data Exchange (ETDEWEB)

    Kojo, Matti [Univ. of Tampere (Finland). Dept. of Political Science and International Relations

    2006-09-15

    In May 1999 Posiva, the company responsible for the final disposal of spent nuclear fuel in Finland, suggested that the Finnish Government considers only Olkiluoto in Eurajoki in its application of a decision in principle to be a final disposal site. In January 2000 the municipal council of Eurajoki made a positive statement on the decision in principle. The Government made the decision in principle in Dec 2000, and the Parliament ratified the decision in May 2001. The paper is focused on the decision making of Eurajoki municipality regarding the siting of the spent nuclear fuel repository. The paper shows how the interaction between the representatives of the candidate municipality and the nuclear energy industry was the crucial factor in the decision-making. Eurajoki serves as an example, in where the parties reached an agreement of the compensations for the final disposal repository. The negotiations between the Eurajoki municipality and the nuclear energy industry in reaching a positive decision are analysed from the beginning of the 1980s. The main emphasis is however on the years 1996-99, when the nuclear energy industry negotiated with the municipality on the compensation for the final disposal repository. The loss of income was an important reason why some of the councillors of Eurajoki were interested in having the final disposal repository in Olkiluoto. The industry's problem on the other hand was to safeguard the final disposal site. From the TVO's angle Olkiluoto was a potential final disposal site for example for its limited need for transport and for the existing infrastructure. The company used the financial benefits of the project as its trump card. The attitude of Eurajoki municipality to the final disposal of spent nuclear fuel turned positive with the Olkiluoto vision in December 1998, when still five years earlier the municipal council was prepared to act and prevent the final disposal. The future image presented by the municipality

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

    International Nuclear Information System (INIS)

    Westerlind, Magnus; Wiklund, Aasa

    2001-01-01

    The problem of bringing all stakeholders on the scene to penetrate an issue of great complexity is not unique for nuclear waste management. There are an increasing number of site selection processes for disposal of nuclear waste around the world. During the 90's many of these siting processes have gone into a more decisive phase where public participation and transparency get more and more attention. Municipalities, NGOs and the public do no longer accept ready-made solutions but have legitimate claims to be part of the decision making and siting processes at an early stage. The attempts to increase the level of transparency and public involvement differ from country to country and depend e.g. on culture, history and societal conditions as well as on the precise phase in the siting process. However, many processes include public hearings as one tool to enhance transparency. In general, Sweden has not a long history of using hearings in decision making. In the area of nuclear waste management and disposal hearings have so far been rarely used. In 1997 and 1998 two public hearings were arranged by the Swedish Nuclear Power Inspectorate, SKI, in conjunction with the licensing of the enlargement of the Central Interim Storage for Spent Nuclear Fuel, CLAB. These hearings showed that hearings could improve the decision making process. SKI and SSI strongly believe the effort was worthwhile and that hearings will continue to be used in the nuclear waste programme. The hearings provided a forum for local stakeholders to pose questions and stretch both the implementer and to some extent also the authorities. The hearings managed to focus on relevant issues at this stage of the siting process and gave the audience a chance to evaluate and challenge the trustworthiness of the implementer and authorities. In this respect the hearings contributed to transparent and democratic decision making. Some of the keys to the success were: Unbiased and skilled moderators with capacity to

  3. Final repository for spent nuclear fuel. Underground design Simpevarp, Layout D1

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-04-15

    This report is a compilation of the results of the underground design work carried out in design phase D1 of the Repository Design Project within the Deep Repository Project for the Simpevarp site. Similar reports are also being produced for the Laxemar and Forsmark sites. The design phase coincides with the initial site investigation phase. The main purpose of phase D1 is to answer the question 'Can a final repository be accommodated within the designated site', but also to test the design methodology and provide feedback to the modelling project. Design was carried out in accordance with the methodology described in UDP (Underground Design Premises), SKB R-04-60, and was based on preliminary data from various disciplines in the site modelling project. The preliminary input data used were then cross-checked against data in the final Site Descriptive Model SDM v 1.2 and significant differences were integrated in the design work. The design results from each design topic were presented by the designer at presentation meetings for SKB's design management and the reviewers engaged by SKB for the specific topic. After the presentation meeting the designer wrote up the work reports for the topic in question. The work reports were then reviewed by SKB's review team. The results of the review were compiled in a statement that was submitted to the designer to be dealt with. In the statement the designer documented which comments were dealt with and how. This report is a compilation of the entire design phase D1 for Simpevarp. The 3D layout with coordinate lists for deposition holes and tunnels that was drawn to illustrate a possible layout was used in the Preliminary safety evaluation of the Simpevarp subarea and the hydro modelling of the Open Repository, both activities within the Deep Repository Project. According to current plans for the Swedish nuclear programme, the minimum required number of canister positions in the repository is estimated to be

  4. On the environmental impact of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Brotzen, O.

    1983-04-01

    A worst case estimate is presented of the contamination of groundwater discharging at the surface. The contamination originates from uranium and actinides in spent nuclear fuel emplaced at ca 500 m depth in fractured, water-saturated, crystalline rock. No engineered barriers are considered, the fuel is free to interact with ground-water and the host rock. Redox processes in a radiolysis zone, and in interaction with the rock, precipitations and absorptions are considered. The contaminated water is assumed to reach the surface through a highly water-conducting fracture zone. The contamination would then take more than 300000 years to reach the surface, and would mainly consist of uranium, actinides would not exceed their ratio to uranium in the fuel. The fuel uranium content in surfacing ground-water would be of the order of one percent of the average surface well content in Sweden. (P.Aa.)

  5. Safety assessment for a potential SNF repository and its implication to the proliferation resistance nuclear fuel cycle

    International Nuclear Information System (INIS)

    Hwang, Y.; Jeong, M.S.; Seo, C.S.

    2007-01-01

    KAERI is developing the pyro-process technology to minimize the burden on permanent disposal of spent nuclear fuel. In addition, KAERI has developed the Korean Reference System for potential spent nuclear fuel disposal since 1997. The deep geologic disposal system is composed of a multi-barrier system in a crystalline rock to dispose of 36,000 MT of spent nuclear fuel (SNF) from a CANDU and a PWR. Quite recently, introduction of advanced nuclear fuel cycles such as pyro-processing is a big issue to solve the everlasting disposal problem and to assure the sustainable supply of fuel for reactors. To compare the effect of direct disposal of SNF with that of the high level waste disposal for waste generated from the advanced nuclear fuel cycles, the total system performance assessment for two different schemes is developed; one for direct disposal of SNF and the other for the introduction of the pyro-processing and direct disposal CANDU spent nuclear fuel. The safety indicators to assess the environmental friendliness of the disposal option are annual individual doses, toxicities and risks. Even though many scientists use the toxicity to understand the environmental friendliness of the disposal, scientifically the annual individual doses or risks are meaningful indicators for it. The major mechanisms to determine the doses and risks for direct disposal are as follows: (1) Dissolution mechanisms of uranium dioxides which control the dissolution of most nuclides such as TRU's and most parts of fission products. (2) Instant release fraction of highly soluble nuclides such as I-129, C-135, Tc-99, and others. (3) Retardation and dilution effect of natural and engineered barriers. (4) Dilution effect in the biosphere. The dominant nuclide is I-129 which follows both congruent and instantaneous release modes. Since its long half life associated with the instantaneous release I-129 is dominant well beyond one million. The impact of the TRU's is negligible until the significant

  6. Groundwater chemistry around a repository for spent nuclear fuel over a glacial cycle. Evaluation for SR-Can

    International Nuclear Information System (INIS)

    Auque, L.F.; Gimeno, M.J.; Gomez, J.B.; Puigdomenech, I.; Smellie, J.; Tullborg, E.L.

    2007-12-01

    The chemical composition of groundwater in the rock volume surrounding a spent nuclear fuel repository is of importance to many factors that affect repository performance. The geochemical characteristics of present-day Swedish groundwater systems are governed by successive mixing events of several waters during the post-glacial evolution of the sites. The expected development of groundwaters at two Swedish sites - Forsmark and Laxemar - during a glacial cycle has been evaluated within the SR-Can project, and the results are presented in this report. For the temperate period following repository closure, an approach is proposed here to investigate the spatial and temporal evolution of groundwater geochemistry by coupling hydrogeological and geochemical models in a sequential way. The procedure combines hydrogeological results obtained with CONNECTFLOW within the SR-Can project with a mixing and reaction path simulation using PHREEQC. The hydrological results contain mixing proportions of four component waters (a deep brine, glacial meltwater, marine water, and meteoric infiltration) at each time step and at every node of the D regional model domain. In this work the mixing fractions are fed into PHREEQC using software developed to build formatted input files and to extract the information from output files for subsequent plotting and analysis. The geochemical calculations included both chemical mixing and equilibrium reactions with selected minerals: calcite, chalcedony and an Fe(III) oxy-hydroxide. Results for the Forsmark and Laxemar sites are graphically presented as histograms and box-and-whisker plots. Cross sections, where each node is colour-coded with respect to an important variable (pH, Eh or concentrations of main elements), are used to visualize the future evolution of the site. Sensitivity analyses are made to evaluate the effects of the different reactions and/or assumptions. The results reflect the progressive inflow of meteoric waters into the sites

  7. Groundwater chemistry around a repository for spent nuclear fuel over a glacial cycle. Evaluation for SR-Can

    Energy Technology Data Exchange (ETDEWEB)

    Auque, L.F.; Gimeno, M.J.; Gomez, J.B. [University of Zaragoza (Spain); Puigdomenech, I. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Smellie, J. [Conterra AB, Uppsala (Sweden); Tullborg, E.L. [Terralogica AB, Graabo (Sweden)

    2007-12-15

    The chemical composition of groundwater in the rock volume surrounding a spent nuclear fuel repository is of importance to many factors that affect repository performance. The geochemical characteristics of present-day Swedish groundwater systems are governed by successive mixing events of several waters during the post-glacial evolution of the sites. The expected development of groundwaters at two Swedish sites - Forsmark and Laxemar - during a glacial cycle has been evaluated within the SR-Can project, and the results are presented in this report. For the temperate period following repository closure, an approach is proposed here to investigate the spatial and temporal evolution of groundwater geochemistry by coupling hydrogeological and geochemical models in a sequential way. The procedure combines hydrogeological results obtained with CONNECTFLOW within the SR-Can project with a mixing and reaction path simulation using PHREEQC. The hydrological results contain mixing proportions of four component waters (a deep brine, glacial meltwater, marine water, and meteoric infiltration) at each time step and at every node of the D regional model domain. In this work the mixing fractions are fed into PHREEQC using software developed to build formatted input files and to extract the information from output files for subsequent plotting and analysis. The geochemical calculations included both chemical mixing and equilibrium reactions with selected minerals: calcite, chalcedony and an Fe(III) oxy-hydroxide. Results for the Forsmark and Laxemar sites are graphically presented as histograms and box-and-whisker plots. Cross sections, where each node is colour-coded with respect to an important variable (pH, Eh or concentrations of main elements), are used to visualize the future evolution of the site. Sensitivity analyses are made to evaluate the effects of the different reactions and/or assumptions. The results reflect the progressive inflow of meteoric waters into the sites

  8. Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors

    Energy Technology Data Exchange (ETDEWEB)

    Gascoyne, M. [Gascoyne GeoProjects Inc, Pinawa, MB (Canada)

    1999-04-01

    Penetration of oxidising groundwaters to depths of 500 m in a permeable bedrock, over a glacial/interglacial cycle, may compromise the stability of a spent nuclear fuel repository and cause the release and migration towards the surface of actinides and associated fission products. This report examines the potential for the penetration of oxygen (O{sub 2}) to depths of 500 m in a fractured crystalline rock environment, typical of the Fennoscandian Shield. Previous studies performed for the Swedish program of nuclear waste disposal (principally the SITE-94 safety assessment) have indicated that O{sub 2} might reach repository depths during a deglaciation when melt-water from the base of an ice sheet could enter the bedrock, driven by strong hydraulic gradients. This report re-examines aspects of this scenario and finds that: 1. The capacity of flow-path minerals to scavenge O{sub 2} from recharging groundwater may be lower than expected due to a previously unrecognised depletion of Fe(II)-bearing minerals in the active flow-paths in a fractured crystalline rock. 2. Assumptions in the SITE-94 assessment, such as the use of a continental-scale flow model, the lack of structural controls on groundwater flow, a preferred horizontal permeability, and the use of permeabilities to depths of 10 km that are up to two orders of magnitude greater than comparable environments, are disproportionately simplistic and represent an extremely conservative case. 3. Assumptions of a thin, discontinuous permafrost, a warm-based ice sheet, and high-O{sub 2} content melt-water at the repository site are unrealistic and overly conservative. A more realistic scenario, which includes a greater influence of permafrost, a cold based ice sheet, lower bedrock permeabilities and a more-limited, regional-scale flow path, is recommended as being more appropriate for use in the safety assessment. Under this revised scenario, it is believed that O{sub 2} will not penetrate to repository depths over

  9. Long-term maintenance of reducing conditions in a spent nuclear fuel repository. A re-examination of critical factors

    International Nuclear Information System (INIS)

    Gascoyne, M.

    1999-04-01

    Penetration of oxidising groundwaters to depths of 500 m in a permeable bedrock, over a glacial/interglacial cycle, may compromise the stability of a spent nuclear fuel repository and cause the release and migration towards the surface of actinides and associated fission products. This report examines the potential for the penetration of oxygen (O 2 ) to depths of 500 m in a fractured crystalline rock environment, typical of the Fennoscandian Shield. Previous studies performed for the Swedish program of nuclear waste disposal (principally the SITE-94 safety assessment) have indicated that O 2 might reach repository depths during a deglaciation when melt-water from the base of an ice sheet could enter the bedrock, driven by strong hydraulic gradients. This report re-examines aspects of this scenario and finds that: 1. The capacity of flow-path minerals to scavenge O 2 from recharging groundwater may be lower than expected due to a previously unrecognised depletion of Fe(II)-bearing minerals in the active flow-paths in a fractured crystalline rock. 2. Assumptions in the SITE-94 assessment, such as the use of a continental-scale flow model, the lack of structural controls on groundwater flow, a preferred horizontal permeability, and the use of permeabilities to depths of 10 km that are up to two orders of magnitude greater than comparable environments, are disproportionately simplistic and represent an extremely conservative case. 3. Assumptions of a thin, discontinuous permafrost, a warm-based ice sheet, and high-O 2 content melt-water at the repository site are unrealistic and overly conservative. A more realistic scenario, which includes a greater influence of permafrost, a cold based ice sheet, lower bedrock permeabilities and a more-limited, regional-scale flow path, is recommended as being more appropriate for use in the safety assessment. Under this revised scenario, it is believed that O 2 will not penetrate to repository depths over the next 100,000 years

  10. Final repository for spent nuclear fuel in granite - the KBS-3V concept in Sweden and Finland

    International Nuclear Information System (INIS)

    Pettersson, Stig; Loennerberg, Bengt

    2008-01-01

    Both Sweden and Finland has advanced plans for design, construction and operation of the final repositories for direct disposal of spent nuclear fuel. Both countries have the same type of host rock - granite. They are also investigating alternative concept for disposal, vertical or horizontal disposal of the canisters with encapsulated spent nuclear fuel, normally called KBS-3V or the KBS-3H disposal concept. The development of the KBS-3V concept started around 1980 and is the reference method for both SKB in Sweden and Posiva in Finland. However, extensive development work is ongoing since 2001 with KBS-3H in order to bring that concept to the same maturity as KBS-3V. This presentation deals with the design and operation of the KBS-3V based on the work done within Sweden and SKB but the development is Finland is identical and it is a close cooperation between SKB in Sweden and Posiva in Finland. In Sweden, the site investigation for location of the repository has been concentrated on two sites, in the Oskarshamn area, about 350 km south of Stockholm, and the Forsmark area, about 180 km north of Stockholm. For information it can be mentioned that Finland plans to locate their repository in the vicinity of the Olkiluoto nuclear power plant site, about 300 km north of Helsinki. The site investigation is completed and the selection of site is scheduled to mid 2009 and sending in the application for location and construction of the repository is scheduled to end 2009. After receiving all necessary permits, construction time and commissioning will take about 7 to 8 years and operation is expected to start about 2020. The KBS-3 system is based on a multi barrier concept and the work with compiling the design requirements for the underground part of the deep repository has been ongoing for some time within the SKB organisation. Today the design requirements for the underground part are documented in a big number of reports that has been produced by specialists and working

  11. Coupling fuel cycles with repositories: how repository institutional choices may impact fuel cycle design

    International Nuclear Information System (INIS)

    Forsberg, C.; Miller, W.F.

    2013-01-01

    The historical repository siting strategy in the United States has been a top-down approach driven by federal government decision making but it has been a failure. This policy has led to dispatching fuel cycle facilities in different states. The U.S. government is now considering an alternative repository siting strategy based on voluntary agreements with state governments. If that occurs, state governments become key decision makers. They have different priorities. Those priorities may change the characteristics of the repository and the fuel cycle. State government priorities, when considering hosting a repository, are safety, financial incentives and jobs. It follows that states will demand that a repository be the center of the back end of the fuel cycle as a condition of hosting it. For example, states will push for collocation of transportation services, safeguards training, and navy/private SNF (Spent Nuclear Fuel) inspection at the repository site. Such activities would more than double local employment relative to what was planned for the Yucca Mountain-type repository. States may demand (1) the right to take future title of the SNF so if recycle became economic the reprocessing plant would be built at the repository site and (2) the right of a certain fraction of the repository capacity for foreign SNF. That would open the future option of leasing of fuel to foreign utilities with disposal of the SNF in the repository but with the state-government condition that the front-end fuel-cycle enrichment and fuel fabrication facilities be located in that state

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

    International Nuclear Information System (INIS)

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

    2012-01-01

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

  13. Framework programme for detailed characterisation in connection with construction and operation of a final repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    2010-10-15

    This report presents a programme for the detailed investigations planned to be applied during construction and operation of the repository for spent nuclear fuel at Forsmark. The report is part of SKB's application according to the Nuclear Activities Act. The detailed investigations shall provide relevant data on and site-descriptive models for the bedrock, soil deposits and eco-system of the site in order to facilitate a step-wise design and construction of the final repository. This shall be implemented in a manner that all demands on long-term safety are fulfilled, including accurate documentation of the construction work, and so that assessments of the environmental impact of the repository can be made. For the operational phase, the detailed investigations should also provide support to the deposition process with related decisions, thereby enabling fulfilment of the design premises for the siting and construction of deposition tunnels and deposition holes, as well as for deposition of canisters, and for the subsequent backfilling and closure of the repository. The Observational Method will be applied during the construction of the repository. This method entails establishing in advance acceptable limits of behaviour regarding selected geoscientific parameters and preparing a plan with measures to keep the outcome within these limits. Predictions of expected rock properties are established for each tunnel section. The outcome after excavation is compared with the acceptable range of outcomes. Information from detailed characterization will be of essential importance for application of the Observational Method and for adapting the repository to the prevailing rock properties. SKB has for the past several decades developed methods for site characterisation, applying both above- and underground investigation techniques. Experiences from this work, put into practice during the site investigations, has resulted in a solid knowledge and understanding of the

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

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, A [ed.

    1999-11-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    Hedin, A. [ed.

    1999-11-01

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

  16. Repository for spent nuclear fuel. Plant description layout D - Forsmark; Slutfoervarsanlaeggning foer anvaent kaernbraensle. Anlaeggningsbeskrivning layout D - Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    2010-07-15

    This document describes the final repository for spent nuclear fuel, SFK, which is located at Forsmark, in Oesthammar. The bedrock at the site is part of a so-called tectonic lens, in which the rock composition is relatively homogeneous and less deformed than outside the lens. The bedrock consists mainly of granite with high quartz content and good thermal conductivity. The central parts above ground are grouped in an operations area, located at the Soederviken on the south side of the intake duct for cooling water for nuclear power plant. Operating area is divided into an internal, secured portion, where the canisters of fuel are handled and there are links to the underground part, and a outer part, where the buffer, backfill and sealing used in the repository's barriers are produced. The above-ground part of the plant and also include storage of excavated rock, ventilation stations, and supplies of bentonite. The underground portion consists of a central area and a storage area. Caverns of the central area contain features for the underground operation. It communicates with the internal operating range above ground via a spiral ramp and several shafts. The ramp used to transport capsules of spent fuel and other heavy or bulky transport. The shafts are used to transport rock, buffer, backfill and staff, as well as for ventilation. The largest part of the space below ground is the repository where the canisters with the spent fuel are disposed. The capsules are deposited in vertical holes in the tunnels. When the deposit in a tunnel is complete, the tunnel is re-filled. The two main activities underground is rock work and disposal work, which are conducted separately from each other. Rock works covers all steps required to excavate tunnels and drill deposition holes, as well as to make temporary installations in the tunnels. To the landfill works count, besides the deposit of the capsule, the placement of the bentonite buffer in the deposition hole and

  17. Microbial degradation processes in radioactive waste repository and in nuclear fuel storage areas

    International Nuclear Information System (INIS)

    Wolfram, J.H.; Rogers, R.D.; Gazso, L.G.

    1997-01-01

    The intent of the workshop organizers was to convene experts in the fields of corrosion and spent nuclear fuels. The major points which evolved from the interaction of microbiologists, material scientists, and fuel storage experts are as follows: Corrosion of basin components as well as fuel containers or cladding is occurring; Water chemistry monitoring, if done in the storage facility does not take into account the microbial component; Microbial influenced corrosion is an area that many have not considered to be an important contributor in the aging of metallurgical materials especially those exposed to a radiation field; Many observations indicate that there is a microbial or biological presence in the storage facilities but these observations have not been correlated with any deterioration or aging phenomena taking place in the storage facility; The sessions on the fundamentals of microbial influenced corrosion and biofilm pointed out that these phenomena are real, occurring on similar materials in other industries and probably are occurring in the wet storage of spent fuel; All agreed that more monitoring, testing, and education in the field of biological mediate processes be performed and financially supported; Loosing the integrity of fuel assemblies can only cause problems, relating to the future disposition of the fuel, safety concerns, and environmental issues; In other rad waste scenarios, biological processes may be playing a role, for instance in the mobility of radionuclides in soil, decomposition of organic materials of the rad waste, gas production, etc. The fundamental scientific presentations discussed the full gamut of microbial processes that relate to biological mediated effects on metallic and non-metallic materials used in the storage and containment of radioactive materials

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

    Directory of Open Access Journals (Sweden)

    Kaláb Zdeněk

    2017-07-01

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

  19. SKI's and SSI's experiences from their participation in the siting of a final repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Westerlind, M.; Hedberg, B.

    2000-01-01

    This paper summarises some experiences gained by the SKI and SSI during the ongoing process for siting a final repository for spent nuclear fuel. The focus is on activities in the municipalities involved in the siting process. In order to give the proper context some basic elements in the legislation, which are important for public participation and confidence in the siting process, are outlined. The importance of clearly defined responsibilities and early participation of the regulators in the siting process are emphasised. It should be pointed out that this paper is not a comprehensive review of the Swedish situation but only contains a few selected issues and personal remarks from the authors. Thus, the views and opinions do not necessarily coincide with those of SKI and SSI. (authors)

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

    International Nuclear Information System (INIS)

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

    2013-01-01

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

  1. Room at the Mountain: Estimated Maximum Amounts of Commercial Spent Nuclear Fuel Capable of Disposal in a Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Kessler, John H.; Kemeny, John; King, Fraser; Ross, Alan M.; Ross, Benjamen

    2006-01-01

    The purpose of this paper is to present an initial analysis of the maximum amount of commercial spent nuclear fuel (CSNF) that could be emplaced into a geological repository at Yucca Mountain. This analysis identifies and uses programmatic, material, and geological constraints and factors that affect this estimation of maximum amount of CSNF for disposal. The conclusion of this initial analysis is that the current legislative limit on Yucca Mountain disposal capacity, 63,000 MTHM of CSNF, is a small fraction of the available physical capacity of the Yucca Mountain system assuming the current high-temperature operating mode (HTOM) design. EPRI is confident that at least four times the legislative limit for CSNF (∼260,000 MTHM) can be emplaced in the Yucca Mountain system. It is possible that with additional site characterization, upwards of nine times the legislative limit (∼570,000 MTHM) could be emplaced. (authors)

  2. Analyses of the double-layed repository concepts for spent nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Lee, Jong Youl; Kim, Hyeona; Lee, Min Soo; Choi, Heui Joo; Kim, Kyung Su [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

    2017-06-15

    A deep geological disposal at a depth of 500 m in stable host rock is considered to be the safest method with current technologies for disposal of spent fuels classified as high-level radioactive waste. The most important requirement is that the temperature of the bentonite buffer, which is a component of the engineered barrier, should not exceed 100℃. In Korea, the amount of spent fuel generated by nuclear power generation, which accounts for about 30% of the total electricity, is continuously increasing and accumulating. Accordingly, the area required to dispose of it is also increasing. In this study, various duplex disposal concepts were derived for the purpose of improving the disposal efficiency by reducing the disposal area. Based on these concepts, thermal analyses were carried out to confirm whether the critical disposal system requirements were met, and the thermal stability of the disposal system was evaluated by analyzing the results. The results showed that upward 75 m or downward 75 m apart from the reference disposal system location of 500 m depth would qualify for the double layered disposal concept. The results of this study can be applied to the establishment of spent fuel management policy and the design of practical commercial disposal system. Detailed analyses with data of a real disposal site are necessary.

  3. Generic repository concept for RBMK-1500 spent nuclear fuel disposal in crystalline rocks in Lithuania

    International Nuclear Information System (INIS)

    Poskas, P.; Brazauskaite, A.; Narkunas, E.; Smaizys, A.; Sirvydas, A.

    2006-01-01

    During 2002-2005 investigations on possibilities to dispose of spent nuclear fuel (SNF) in Lithuania were performed with support of Swedish experts. Disposal concept for RBMK-1500 SNF in crystalline rocks in Lithuania is based on Swedish KBS-3 concept with SNF emplacement into the copper canister with cast iron insert. The bentonite and its mixture with crushed rock are also foreseen as buffer and backfill material. In this paper modelling results on thermal, criticality and other important disposal characteristics for RBMK-1500 SNF fuel emplaced in copper canisters are presented. Based on thermal calculations, the distances between the canisters and between the tunnels were justified. Criticality calculations for the canister with fresh fuel with 2.8 % 235 U enrichment demonstrated that effective neutron multiplication factor k eff values are less than allowable value of 0.95. Dose calculations have shown that total equivalent dose rate from the canister with 50 years stored RBMK-1500 SNF is rather high and is defined mainly by the γ radiation. (author)

  4. Status of Proposed Repository for Latin-American Spent Fuel

    Energy Technology Data Exchange (ETDEWEB)

    Ferrada, J.J.

    2004-10-04

    This report compiles preliminary information that supports the premise that a repository is needed in Latin America and analyzes the nuclear situation (mainly in Argentina and Brazil) in terms of nuclear capabilities, inventories, and regional spent-fuel repositories. The report is based on several sources and summarizes (1) the nuclear capabilities in Latin America and establishes the framework for the need of a permanent repository, (2) the International Atomic Energy Agency (IAEA) approach for a regional spent-fuel repository and describes the support that international institutions are lending to this issue, (3) the current situation in Argentina in order to analyze the Argentinean willingness to find a location for a deep geological repository, and (4) the issues involved in selecting a location for the repository and identifies a potential location. This report then draws conclusions based on an analysis of this information. The focus of this report is mainly on spent fuel and does not elaborate on other radiological waste sources.

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

    Science.gov (United States)

    Kaláb, Zdeněk; Šílený, Jan; Lednická, Markéta

    2017-07-01

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

  6. Geochemical modelling of the evolution of a granite-concrete-water system around a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Fritz, B.; Made, B.; Tardy, Y.

    1988-04-01

    The interactions between a granitic rock and concrete due to the natural solutions circulating around a repository for spent nuclear fuel has been simulated considering the dissolution of Ca(OH) 2 as the major source of alkalinity due to the concrete. This study follows a previous one considering the same interaction without concrete at 25, 60 and 100 deg C. The temperature range has been extended to 150 deg C. The results of the modelling are considered as following: - evolution of the water chemistry due to detected pssible chemical reactions. - minerals produced and dissolved. The calculations give mass transfers and volumic consequences (opening or closing tendencies). The conclusions of this yearly report are mainly the following: (1) the extent of the temperature range for the storage (up to 150 deg C) does not change the tendencies previously detected in the same conditions without any particular alkaline effect due to concrete dissolution, the reactions occurring tend to decrease the porosity of the rock by a sealing effect due to calcite precipitation and clays formation. (2) The effect of an alkaline concrete dissolution is clearly important, pH may reach very high values in closed system, and the volumic consequence is found in favour of an opening of the porosity, at the stage of saturation of the portlandite. This is probably an important point considering the security of natural barriers around such a repository. (authors)

  7. Presentation of safety after closure of the repository for spent nuclear fuel. Main report of the project SR-Site. Part III

    International Nuclear Information System (INIS)

    2011-01-01

    The purpose of the safety assessment SR-Site is to investigate whether a safe repository for spent nuclear fuel by KBS-3 type can be constructed at Forsmark in Oesthammar in Sweden. The location of the Forsmark has been selected based on results of several surveys from surface conditions at depth in Forsmark and in Laxemar in Oskarshamn. The choice of location is not justified in SR-Site Report, but in other attachments to SKB's permit applications. SR-Site Report is an important part of SKB's permit applications to construct and operate a repository for spent nuclear fuel at Forsmark in Oesthammar. The purpose of the report in the applications is to show that a repository at Forsmark is safe after closure

  8. Presentation of safety after closure of the repository for spent nuclear fuel. Main report of the project SR-Site. Part I

    International Nuclear Information System (INIS)

    2011-01-01

    The purpose of the safety assessment SR-Site is to investigate whether a safe repository for spent nuclear fuel by KBS-3 type can be constructed at Forsmark in Oesthammar in Sweden. The location of the Forsmark has been selected based on results of several surveys from surface conditions at depth in Forsmark and in Laxemar in Oskarshamn. The choice of location is not justified in SR-Site Report, but in other attachments to SKB's permit applications. SR-Site Report is an important part of SKB's permit applications to construct and operate a repository for spent nuclear fuel at Forsmark in Oesthammar. The purpose of the report in the applications is to show that a repository at Forsmark is safe after closure

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

    International Nuclear Information System (INIS)

    1999-01-01

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

  10. Experimental investigation of hydrous pyrolysis of diesel fuel and the effect of pyrolysis products on performance of the candidate nuclear waste repository at Yucca Mountain, Nevada

    International Nuclear Information System (INIS)

    Jackson, K.J.; Carroll, S.A.

    1994-01-01

    It is thought that a significant amount of diesel fuel and other hydrocarbon-rich phases may remain inside the candidate nuclear waste repository at Yucca Mountain after construction and subsequent emplacement of radioactive waste. Although the proposed repository horizon is above the water table, the remnant hydrocarbon phases may react with hydrothermal solutions generated by high temperature conditions that will prevail for a period of time in the repository. The preliminary experimental results of this study show that diesel fuel hydrous pyrolysis is minimal at 200 degrees C and 70 bars. The composition of the diesel fuel remained constant throughout the experiment and the concentration of carboxylic acids in the aqueous phases was only slightly above the detection limit (1-2 ppm) of the analytical technique

  11. Towards a Swedish repository for spent fuel

    International Nuclear Information System (INIS)

    Ahlstroem, P.-E.

    1997-01-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2015-07-01

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

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

    International Nuclear Information System (INIS)

    2002-11-01

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

  14. Experiences of risk in connection with site selection for a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Biel, A.; Dahlstrand, U.

    1991-03-01

    Describes an investigation of the experiences of risks the the Swedish inhabitants have in connection with site selection for a repository for radioactive waste. The attitudes show a rather complicated picture. It is influenced by such factors as: sex, education and distance to the facility. (KAE)

  15. Functioning of blocks of compacted bentonite in a repository for spent nuclear fuels

    International Nuclear Information System (INIS)

    Boergesson, Lennart; Kalbantner, P.; Sjoeblom, R.

    2001-12-01

    The main purpose of the presented work is to provide The Swedish Nuclear Fuel and Waste Management Company (SKB) with a proposed set of requirements regarding the functioning of the blocks of compacted bentonite. These blocks are intended to constitute the bentonite envelope which after uptake of water will form the buffer between the canister and the rock. The purpose is also to provide a basis for SKB for their direction of the continued development work for the selection of a reference technology and for creating a quality system for the buffer material. No attempts are made in the report to derive the functional requirements. Instead, such requirements are postulated based on realistic scenarios regarding the chain of processes from excavation - transport - preparation of press powder - compaction - handling and emplacement in the deposition hole. It is the strategy of SKB to use a natural material which after the above-mentioned processes forms a buffer with properties which closely resemble those of the original material. This implies that all process steps must be designed in such a way that the properties of the bentonite do not change to any significant degree with respect to the disposal function. The main results in the report are as follows: A set of functional requirements are compiled and presented. These concord with the different descriptions given on the process steps. The requirements are generic and are assessed to be relatively invariant for various operational requirements and process controls. The process chain comprising excavation of bentonite - transport - preparation of press powder - compaction - handling and emplacement are explained. The presentations of functional requirements and processes are foreseen to constitute a basis for a comparison between uniaxial and isostatic compaction and can be an important basis for SKB's quality work. The development of cracks in the bentonite blocks has been identified as an important aspect for the

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

    Energy Technology Data Exchange (ETDEWEB)

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

    1999-12-01

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

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

    International Nuclear Information System (INIS)

    1995-10-01

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

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1995-10-01

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

  19. Investigations of possibilities to dispose of spent nuclear fuel in Lithuania: a model case. Volume 3, Generic Safety Assessment of Repository in Crystalline Rocks

    International Nuclear Information System (INIS)

    Motiejunas, S.; Poskas, P.

    2005-01-01

    In this Volume a generic safety assessment of the repository for spent nuclear fuel in crystalline rock in Lithuania is presented. Modeling of safety relevant radionuclide release from the defected canister and their transport through the near field and far field was performed. Doses to humans due to released radionuclides in the well water were calculated and compared with the dose restrictions existing in Lithuania. For this stage of generic safety assessment only two scenarios were chosen: base scenario and canister defect scenario. KBS-3 concept developed by SKB for disposal of spent nuclear fuel in Sweden was chosen as prototype for repository in crystalline basement in Lithuania. The KBS-3H design with horizontal canister emplacement is proposed as a reference design for Lithuania

  20. Basis for applying for exemption according to species protection regulation. Final repository for spent nuclear fuel at Forsmark

    International Nuclear Information System (INIS)

    2011-02-01

    SKB will submit applications for permits and admissibility under the Environmental Act and under the Nuclear Activities Act to construct and operate a disposal facility for spent nuclear fuel at Forsmark. In the final repository the spent nuclear fuel from Swedish nuclear power plants is placed in order to protect human health and the environment against harmful effects of ionizing radiation. Construction and operation of the disposal facility in Forsmark will make an impact, give effects and consequences for the natural environment. Utilization of land for the construction of the facility and the impact on ground water as a result of groundwater drainage is expected to have negative consequences for the species included in species protection regulation. Thus, the planned activity require exemption from species protection regulation (SFS 2007:845). The purpose of this document is to provide a basis for an application for exemption under 14 paragraph species protection regulation from the prohibitions of 4, 6, 7 and 8 paragraph species protection regulation. A basis for the exemption application is that the proposed activity is considered to have an 'overriding public interest' prescribed in 14 paragraph species protection regulation. The document reports the impact, effects and consequences of the planned activities on species covered in the species protection regulation. The impact on protected species can be divided into two categories: - Direct effects on protected species and their habitats by utilization of the land. - Indirect effects on protected species and their habitats in the drainage of groundwater and the effect on groundwater levels. The document also includes a description of planned actions to prevent, restrict and compensate for the effects and consequences that the activity may cause. By applying for an exemption under 14 paragraph species protection regulation in a separate order from the application for permit according to chapters 9 and 11

  1. Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository--Volume 2: Methodology and Results

    International Nuclear Information System (INIS)

    Taylor, L.L.; Wilson, J.R.; Sanchez, L.C.; Aguilar, R.; Trellue, H.R.; Cochrane, K.; Rath, J.S.

    1998-01-01

    The US Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3)

  2. Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository--Volume 2: Methodology and Results

    Energy Technology Data Exchange (ETDEWEB)

    Taylor, L.L.; Wilson, J.R.; Sanchez, L.C.; Aguilar, R.; Trellue, H.R.; Cochrane, K.; Rath, J.S.

    1998-10-01

    The US Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3).

  3. Nuclear Dynamics Consequence Analysis (NDCA) for the Disposal of Spent Nuclear Fuel in an Underground Geologic Repository--Volume 1: Executive Summary

    International Nuclear Information System (INIS)

    Taylor, L.L.; Wilson, J.R.; Sanchez, L.Z.; Aguilar, R.; Trellue, H.R.; Cochrane, K.; Rath, J.S.

    1998-01-01

    The US Department of Energy Office of Environmental Management's (DOE/EM's) National Spent Nuclear Fuel Program (NSNFP), through a collaboration between Sandia National Laboratories (SNL) and Idaho National Engineering and Environmental Laboratory (INEEL), is conducting a systematic Nuclear Dynamics Consequence Analysis (NDCA) of the disposal of SNFs in an underground geologic repository sited in unsaturated tuff. This analysis is intended to provide interim guidance to the DOE for the management of the SNF while they prepare for final compliance evaluation. This report presents results from a Nuclear Dynamics Consequence Analysis (NDCA) that examined the potential consequences and risks of criticality during the long-term disposal of spent nuclear fuel owned by DOE-EM. This analysis investigated the potential of post-closure criticality, the consequences of a criticality excursion, and the probability frequency for post-closure criticality. The results of the NDCA are intended to provide the DOE-EM with a technical basis for measuring risk which can be used for screening arguments to eliminate post-closure criticality FEPs (features, events and processes) from consideration in the compliance assessment because of either low probability or low consequences. This report is composed of an executive summary (Volume 1), the methodology and results of the NDCA (Volume 2), and the applicable appendices (Volume 3)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-09-01

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

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

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Christiansson, Rolf; Lagerstedt, Leif

    2004-09-01

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

  6. Sulphide fluxes and concentrations in the spent nuclear fuel repository at Olkiluoto

    International Nuclear Information System (INIS)

    Wersin, P.; Alt-Epping, P.; Pitkaenen, P.

    2014-01-01

    Sulphide may act as corrodant for the copper canister in the KBS-3 disposal concept. Sulphide fluxes at repository level are affected by various sources in the host rock, the backfill and the buffer. Hydrogen sulphide is effectively immobilised by Fe to form insoluble iron sulphide minerals. Thus, dissolved sulphide levels in reducing environment and also in Olkiluoto groundwaters are generally low. In zones favourable for sulphate reducing bacteria (SRB), however, temporarily more elevated sulphide concentrations are possible. The sulphate reduction and subsequent iron sulphide precipitation process depends on geochemical conditions, microbial activity and mass transfer of the reactants and is thus highly system-specific. The overall objective of the work presented in this report is to provide a thorough background for the sulphide concentrations and sulphide fluxes in the near field and the far field used in the performance assessment 2012

  7. Repository for spent nuclear fuel. Preliminary construction description - layout D Oskarshamn the Simpevarp area

    International Nuclear Information System (INIS)

    2006-02-01

    This report presents the preliminary design of a repository located in the Simpevarp area. The description has been disposed so as to deal primarily with the site dependent layouts for the above- and underground constructions. The report is disposed as follows: c1 gives the background and some basic information. Chapter 2 presents the demands and necessary conditions that take precedence when adapting the plant to the local conditions, construction, operation and closure. Chapter 3 is a general description of the area, its infrastructure and the specific sites that have been studied. Chapter 4-5 describe the design of the plant for the two chosen sites. Chapter 6 gives a review of data for the plant, and Chapter 7 'References' is the last part of the main document. The appendices A-I give brief information on the general, non-site specific, parts of the plant, e.g. buildings, life cycle, system, operation and organization

  8. Repository for spent nuclear fuel. Preliminary construction description - layout D Oskarshamn the Laxemar area

    International Nuclear Information System (INIS)

    2006-05-01

    This report presents the preliminary design of a repository located in the Laxemar area. The description has been disposed so as to deal primarily with the site dependent layouts for the above- and underground constructions. The report is disposed as follows: Chapter 1 gives the background and some basic information. Chapter 2 presents the demands and necessary conditions that take precedence when adapting the plant to the local conditions, construction, operation and closure. Chapter 3 is a general description of the area, its infrastructure and the specific sites that have been studied. Chapters 4-5 describe the design of the plant for the two chosen sites. Chapter 6 gives a review of data for the plant, and Chapter 7 'References' is the last part of the main document. The appendices A-I give brief information on the general, non-site specific, parts of the plant, e.g. buildings, life cycle, system, operation and organization

  9. Multi-barrier system model of the geological repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Barátová, D.; Necas, V.

    2016-01-01

    The results on the analysis of radionuclide release from the geosphere of hypothetical repository in crystalline rocks are presented. Radionuclides with poor retentive properties (C-14, I-129, Cl-36, Cs-135), represent the largest contribution to the total release rate from the geosphere. A sensitivity analysis of selected geosphere parameters was also performed to evaluate an impact of uncertainties on the total maximum release rate from the geosphere. The results show that the data uncertainty related to the transmissivity distribution of individual transport pathways has the greatest impact on the total maximum release rate from the geosphere. The calculations of release rates were carried out for one disposal container using the simulation software GoldSim. (authors)

  10. Impact of long-term climate change on a deep geological repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Boulton, G.S.; Kautsky, U.; Moren, L.; Wallroth, T.

    2001-05-01

    The radioactivity of spent nuclear fuel will decay over a period of time (100,000 years or longer) in which we expect major environmental change. Climatically driven changes such as glaciation, permafrost and changes in sea level will affect the subsurface environment and must therefore be considered in performance and safety assessments. We regard the state of climate to be determined by the climate system, comprising the atmosphere, the biosphere, the oceans, the ice sheets and the surface of the lithosphere. Climate can change as a consequence of external forcing or as a consequence of the internal dynamics. The changes in the past show a complex cyclical pattern with repetitive periodicities and magnitudes of change. On the relatively long time scale which is of concern in this report climate changes are believed to be triggered by changes in insolation due to cyclical changes in the earth's orbit around the sun. This is referred to as the Milankovitch theory or the astronomical climate theory. A brief review of our knowledge of the climate system, proxy records and observations of past climate change is presented in the report. The most extreme departures from modern environmental conditions in Sweden have occurred during the cold, glacial cycles with ice sheets covering the whole of Sweden. As part of SKB's palaeohydrogeological research programme a time-dependent, thermo-mechanically coupled model of ice sheet behaviour has been developed in order to simulate past fluctuations of the Scandinavian ice sheet and forecast its future. The ice sheet model can calculate the temperature field and isostatic response of the underlying bedrock, subglacial and proglacial permafrost and the subglacial melt rates. By connecting the glaciation model with hydrogeological and rock mechanical models, the response of the subsurface to climate change can be investigated. In this report the climate-driven environmental changes are represented as a series of successive climate

  11. Impact of long-term climate change on a deep geological repository for spent nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Boulton, G.S. [Edinburgh Univ. (United Kingdom); Kautsky, U.; Moren, L. [Swedish Nuclear Fuel and Waste Management Co., Stockholm (Sweden); Wallroth, T. [Bergab Consulting Geologists (Sweden)

    2001-05-01

    The radioactivity of spent nuclear fuel will decay over a period of time (100,000 years or longer) in which we expect major environmental change. Climatically driven changes such as glaciation, permafrost and changes in sea level will affect the subsurface environment and must therefore be considered in performance and safety assessments. We regard the state of climate to be determined by the climate system, comprising the atmosphere, the biosphere, the oceans, the ice sheets and the surface of the lithosphere. Climate can change as a consequence of external forcing or as a consequence of the internal dynamics. The changes in the past show a complex cyclical pattern with repetitive periodicities and magnitudes of change. On the relatively long time scale which is of concern in this report climate changes are believed to be triggered by changes in insolation due to cyclical changes in the earth's orbit around the sun. This is referred to as the Milankovitch theory or the astronomical climate theory. A brief review of our knowledge of the climate system, proxy records and observations of past climate change is presented in the report. The most extreme departures from modern environmental conditions in Sweden have occurred during the cold, glacial cycles with ice sheets covering the whole of Sweden. As part of SKB's palaeohydrogeological research programme a time-dependent, thermo-mechanically coupled model of ice sheet behaviour has been developed in order to simulate past fluctuations of the Scandinavian ice sheet and forecast its future. The ice sheet model can calculate the temperature field and isostatic response of the underlying bedrock, subglacial and proglacial permafrost and the subglacial melt rates. By connecting the glaciation model with hydrogeological and rock mechanical models, the response of the subsurface to climate change can be investigated. In this report the climate-driven environmental changes are represented as a series of successive

  12. Some inspirations drawn from the SKB license-application report for the construction of the final repository for spent nuclear fuel in Sweden

    International Nuclear Information System (INIS)

    Xu Guoqing

    2014-01-01

    The following problems are described in this paper: the current state of nuclear energy and spent fuel in Sweden, the brief process of repository site selection and the concise geological settings of candidate site Forsmark, the option of repository design, the data presented in license-application report on repository, construction, the review work presented by OECD/NEA international peer review team (IRT) and some considerations noted by the author: 1) Why the design of underground engineering, also known as 5 shafts + l ramp, is adopted? 2) Why the timescale for the assessment is one million years? 3) Why the computer codes used in performance assessment at Forsmark candidate repository site are different from those used at Yucca Mountain candidate repository site? 4) How to carry out the public involvement, support from local government and volumtary siting in China? 5) What is the most important in the R and D program of HLW disposal? 6) What shall we do for the future license-application report for the construction of the final repository in China? (author)

  13. Nuclear criticality safety analysis of a spent fuel waste package in a tuff repository

    International Nuclear Information System (INIS)

    Weren, B.H.; Capo, M.A.; O'Neal, W.C.

    1983-12-01

    An assessment has been performed of the criticality potential associated with the disposal of spent fuel in a tuff geology above the water table. Eleven potential configurations were defined which cover a vast range of geometries and conditions from the nominal configuration at emplacement to a hypothetical configuration thousands of years after emplacement in which the structure is gone, the fuel pellets disintegrated and the borehole flooded. Of these eleven configurations, four have been evaluated at this time. The results of this evaluation indicate that even with very conservative assumptions (4.5 w/o fresh fuel), criticality is not a problem for the nominal configuration either dry or fully flooded. In the cases where the condition of the waste package is assumed to have severely deteriorated, over long times, calculations were performed with less conservative assumptions (depleted fuel). An assessment of these calculations indicates that criticality safety could be demonstrated if the depletion of the fissile inventory during fuel irradiation is taken into account. A detailed discussion of the calculations performed is presented in this report. Also included are a description of the configurations which were considered, the analytical methods and models used, and a discussion of additional related work which should be performed. 15 references, 11 figures, 8 tables

  14. Nuclear fuels

    International Nuclear Information System (INIS)

    Gangwani, Saloni; Chakrabortty, Sumita

    2011-01-01

    Nuclear fuel is a material that can be consumed to derive nuclear energy, by analogy to chemical fuel that is burned for energy. Nuclear fuels are the most dense sources of energy available. Nuclear fuel in a nuclear fuel cycle can refer to the fuel itself, or to physical objects (for example bundles composed of fuel rods) composed of the fuel material, mixed with structural, neutron moderating, or neutron reflecting materials. Long-lived radioactive waste from the back end of the fuel cycle is especially relevant when designing a complete waste management plan for SNF. When looking at long-term radioactive decay, the actinides in the SNF have a significant influence due to their characteristically long half-lives. Depending on what a nuclear reactor is fueled with, the actinide composition in the SNF will be different. The following paper will also include the uses. advancements, advantages, disadvantages, various processes and behavior of nuclear fuels

  15. Calculated temperature field in and around a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Tarandi, T.

    1983-04-01

    Temperature distribution in and around the final storage has been calculated for BWR-fuel. The results are also applicable to PWR-fuel if the amount of fuel is adjusted so that the power per canister is the same. The calculations are made with the conservative assumption of the coefficient of thermal conductivity of 0.75 W/(m degreeC) in the bentonite and 3.0 W/(m degreeC) in the rock. The amount of BWR fuel is about 1.4 ton per canister. The canisters are deposited 40 years after withdrawal from the reactor. A number of different layouts in single and two-level storages have been studied. Finally, a two-level storage has been chosen as a basis for further project work. The maximum temperature increase of 59.2 degreeC at the surface of the canister is reached about 30 years after the time of deposition. However, in this twolevel storage there will be also a second temperature peak of 58.7 degreeC about 600 years after the deposition. The highest temperature increase in the rock, 56.8 degreeC, occurs about 600 years after the deposition. At the same time as the temperature continues to sink, there is a levelling out of the local temperature differences in the storage. These differences are negligible after about 1000 years. After 100000 years the temperatue in the storage is only a few degrees centigrade above the initial rock temperature. The heat from the storage reaches the ground surface about 200 years after the deposition. The maximum heat flow, 0.28 W/m 2 , occurs about 2000 years after deposition and is considered insignificant compared for example with solar energy flow of about 100 W/m 2 . (author)

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

    International Nuclear Information System (INIS)

    Soderberg, O.

    1998-01-01

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

  17. Leaching of the simulated borosilicate waste glasses and spent nuclear fuel under a repository condition

    International Nuclear Information System (INIS)

    Kim, Seung Soo; Chun, Kwan Sik; Kang, Chul Hyung; Suh, Hang Suk

    2002-12-01

    Leaching behaviors of simulated waste glass and spent fuel, contacted on bentonite blocks, in synthetic granitic groundwater were investigated in this study. The leach rate of boron from borosilicate waste glass between the compacted bentonite blocks reached about 0.03 gm-2day-1 at 1500 days, like as that of molybdenum. However, the concentration of uranium in leachate pass through bentonite blocks was less than their detection limits of 2 μg/L and whose yellow amorphous compound was found on the surface of glass contacted with the bentonite blocks. The leaching mechanism of waste glasses differed with their composition. The release rate of cesium from PWR spent fuel in the simulated granitic water without bentonite was leas than $1.0x10 -5 fraction/day after 300 days. The retardation factor of cesium by a 10 -mm thickness of bentonite block was more than 100 for 4-years leaching time. The cumulative release fraction of uranium for 954 days was 0.016% (1.7x10 -7 fraction/day) in granitic water without bentonite. The gap inventory of cesium for spent fuel G23-J11 was 0.15∼0.2%. However, the release of cesium from C15-I08 was 0.9% until 60 days and has being continued after that. Gap inventories of strontium and iodine in G23-J11 were 0.033% and below 0.2%, respectively. The sum of fraction of cesium in gap and grain boundary of G23-J11 was suggested below 3% and less

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

    International Nuclear Information System (INIS)

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

    2015-01-01

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

  19. Hydrochemical stability of groundwaters surrounding a spent nuclear fuel repository in a 100,000 year perspective

    Energy Technology Data Exchange (ETDEWEB)

    Puigdomeneck, I. (ed.)

    2001-09-01

    This report is focussed on the effects of climate changes on the chemical composition of deep groundwaters. The aim of the work has been to assess the hydrochemical stability at nuclear repository sites in Finland and Sweden. Sites investigated by SKB and POSIVA have been compared. The corresponding features are important in judging how sensitive a site might be to climatic changes. Evidence for climate effects in the past on groundwater compositions has been reviewed, including isotopic and mineralogical data. There is for example evidence that glacial meltwaters are currently present at repository depths in the Fennoscandian Shield. No evidence has been found however that oxidising conditions have ever prevailed at depth, even if glacial meltwaters presumably had a substantial amount of dissolved O{sub 2}. The depth distribution of different calcite types (and other fracture minerals) indicates stability in large-scale groundwater circulation over time. Information on past (and future) groundwater salinities has been sought after in the results of hydrological numerical models for Aespoe in Sweden and Olkiluoto in Finland. It is expected that groundwater salinities will change due to future climatic variations. The main effects will be from shoreline movements, permafrost and continental ice-sheets. In most sites the present reducing redox conditions will remain undisturbed during glacial cycles. The modelling indicated that most of the SKB suitability criteria will be met during the life-span of the repository and the groundwater composition will vary within what is observed in the samples collected today at various depths. The expected changes are therefore not judged to threaten the integrity and functioning of the repository. The major conclusion is that despite long-term hydrodynamic changes hydrochemical stability is expected to dominate at repository depth.

  20. Hydrochemical stability of groundwaters surrounding a spent nuclear fuel repository in a 100,000 year perspective

    International Nuclear Information System (INIS)

    Puigdomeneck, I.

    2001-09-01

    This report is focussed on the effects of climate changes on the chemical composition of deep groundwaters. The aim of the work has been to assess the hydrochemical stability at nuclear repository sites in Finland and Sweden. Sites investigated by SKB and POSIVA have been compared. The corresponding features are important in judging how sensitive a site might be to climatic changes. Evidence for climate effects in the past on groundwater compositions has been reviewed, including isotopic and mineralogical data. There is for example evidence that glacial meltwaters are currently present at repository depths in the Fennoscandian Shield. No evidence has been found however that oxidising conditions have ever prevailed at depth, even if glacial meltwaters presumably had a substantial amount of dissolved O 2 . The depth distribution of different calcite types (and other fracture minerals) indicates stability in large-scale groundwater circulation over time. Information on past (and future) groundwater salinities has been sought after in the results of hydrological numerical models for Aespoe in Sweden and Olkiluoto in Finland. It is expected that groundwater salinities will change due to future climatic variations. The main effects will be from shoreline movements, permafrost and continental ice-sheets. In most sites the present reducing redox conditions will remain undisturbed during glacial cycles. The modelling indicated that most of the SKB suitability criteria will be met during the life-span of the repository and the groundwater composition will vary within what is observed in the samples collected today at various depths. The expected changes are therefore not judged to threaten the integrity and functioning of the repository. The major conclusion is that despite long-term hydrodynamic changes hydrochemical stability is expected to dominate at repository depth

  1. Hydrochemical stability of groundwaters surrounding a spent nuclear fuel repository in a 100,000 year perspective

    Energy Technology Data Exchange (ETDEWEB)

    Puigdomenech, I. (ed.); Gurban, I.; Laaksoharju, M. [and others

    2001-12-01

    This report is focused on the effects of climate changes on the chemical composition of deep groundwaters. The aim of the work has been to assess the hydrochemical stability at nuclear repository sites in Finland and Sweden. Sites investigated by SKB and POSIVA have been compared. The corresponding features are important in judging how sensitive a site might be to climatic changes. Evidence for climate effects in the past on groundwater compositions has been reviewed, including isotopic and mineralogical data. There is for example evidence that glacial meltwaters are currently present at repository depths in the Fennoscandian Shield. No evidence has been found however that oxidising conditions have ever prevailed at depth, even if glacial meltwaters presumably had a substantial amount of dissolved 0{sub 2}. The depth distribution of different calcite types (and other fracture minerals) indicates stability in large-scale groundwater circulation over time. Information on past (and future) groundwater salinities has been sought after in the results of hydrological numerical models for Aespoe in Sweden and Olkiluoto in Finland. It is expected that groundwater salinities will change due to future climatic variations. The main effects will be from shoreline movements, permafrost and continental ice-sheets. In most sites the present reducing redox conditions will remain undisturbed during glacial cycles. The modelling indicated that most of the SKB suitability criteria will be met during the life-span of the repository and the groundwater composition will vary within what is observed in the samples collected today at various depths. The expected changes are therefore not judged to threaten the integrity and functioning of the repository. The major conclusion is that despite long-term hydrodynamic changes hydrochemical stability is expected to dominate at repository depth. (orig.)

  2. Spent fuel performance in geologic repository environments

    International Nuclear Information System (INIS)

    Bradley, D.J.

    1985-10-01

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

  3. 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

  4. 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

  5. Thermal dimensioning of spent fuel repository

    International Nuclear Information System (INIS)

    Ikonen, K.

    2009-09-01

    This report contains the temperature dimensioning of the KBS-3V type nuclear fuel repository in Olkiluoto for the BWR, VVER and EPR fuel canisters, which are disposed at vertical position in the horizontal tunnels in a rectangular geometry according to the preliminary Posiva plan. This report concerns only the temperature dimensioning of the repository and does not take into account the possible restrictions caused by the stresses induced in the rock. The maximum temperature on the canister-bentonite interface is limited to the design temperature of +100 deg C. However, due to uncertainties in thermal analysis parameters (like scattering in rock conductivity or in predicted decay power) the allowable calculated maximum canister temperature is set to 90 deg C causing a safety margin of 10 deg C. The allowable temperature is controlled by adjusting the space between adjacent canisters, adjacent tunnels and the pre-cooling time affecting on power of the canisters. The temperature of canister surfaces can be determined by superposing analytic line heat source models much more efficiently than by numerical analysis, if the analytic model is first calibrated by numerical analysis (by control volume method). This was done by comparing the surface temperatures of a single canister calculated numerically and analytically. For the Olkiluoto repository of one panel having 900 canisters of BWR, VVER and EPR spent fuel was analyzed. The analyses were performed with an initial canister power of 1 700 W, 1 370 W and 1 830 W, respectively. These decay heats are obtained when the pre-cooling times of the fuels are 32.9, 29.6 and 50.3 years (the burn-up values 40, 40 and 50 MWd/kgU, respectively). The analyses gave as a result the canister spacing (6.0-10.8 m), when the tunnel spacing was 25 m, 30 m or 40 m. On the edge areas of the panel with constant canister spacing the temperatures of the canisters are lower than in the middle area of the repository. Thus it is possible to pack

  6. Nuclear fuel

    International Nuclear Information System (INIS)

    D Hondt, P.

    1998-01-01

    The research and development programme on nuclear fuel at the Belgian Nuclear Research Centre SCK/CEN is described. The objective of this programme is to enhance the quantitative prediction of the operational limits of nuclear fuel and to assess the behaviour of fuel under incidental and accidental conditions. Progress is described in different domains including the modelling of fission gas release in LWR fuel, thermal conductivity, basic physical phenomena, post-irradiation examination for fuel performance assessment, and conceptual studies of incidental and accidental fuel experiments

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

    International Nuclear Information System (INIS)

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

    2003-01-01

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

  8. LOT A2 Test, THC-modelling of bentonite buffer in a final repository of spent nuclear fuel

    International Nuclear Information System (INIS)

    Itaelae, A.; Olin, M.; Rasilainen, K.; Pulkkanen, V.M.

    2010-01-01

    Document available in extended abstract form only. The Finnish spent nuclear fuel disposal is planned to be based on the KBS-3V repository concept. Within this concept, the role of the bentonite buffer is considered to be central. The aim of this study was to model the evolution of the buffer during the thermal phase (heat-generating period of spent fuel), when the bentonite is only partially saturated initially, and the surrounding rock matrix is assumed to be fully saturated. It is essential to study how temperature will affect saturation and also how both of these affect the chemistry of bentonite. In order to make the modeling more concrete, an example experimental case was considered: Long Term Test of Buffer Materials (LOT) A2-parcel test at the Aespoe Hard Rock Laboratory (HRL) in Sweden. In the A2-parcel the MX-80 bentonite was exposed to adverse (120-150 deg. C) temperature conditions and high temperature gradients. The test parcel diameter was smaller than in the actual KBS-3V deposition hole to speed up the saturation. The chemical behaviour of minerals causes their redistribution inside the bentonite. For example, according to the laboratory tests, gypsum dissolves and anhydrite precipitates near the heater-bentonite interface. Also, incoming groundwater affects the bentonite pore water and its properties. These changes may, in turn, influence the mechanical properties of the bentonite. A coupled Thermo-Hydro-Chemical (THC) model was applied, which means that all mechanical effects were ignored. The purpose of the model was first to achieve a satisfactory match between the model and experimental results, and, therefore, the time frame was limited to ten years (LOT A-2 parcel test lasted approximately 6 years). The system was simplified to 1-D in order to reduce the computational work, which can be very significant due to complex chemical calculations. The 1-D model results are reported in Itaelae (2009). The aim is to extend the calculations to 2-D

  9. Attitudes towards a final repository for the spent nuclear fuel. Structure and causes; Attityd till slutfoervar av anvaent kaernbraensle. Struktur och orsaker

    Energy Technology Data Exchange (ETDEWEB)

    Sjoeberg, Lennart (Stockholm School of Economics (Sweden). Center for Risk Research)

    2008-09-15

    This report presents the results of a questionnaire survey of attitudes towards a final repository for the spent nuclear fuel. The questionnaire was mailed to 3,000 persons. Participants were young and older people in Oskarshamn municipality and Oesthammar municipality as well as in the rest of the country. Fifty-one percent responded. The questionnaire included a large number of questions of possible relevance for understanding the structure of and reasons for the person's attitude towards a final repository. Questions concerning nuclear power were dealt with in a special section. Men were more positively disposed towards a repository than women, older people more than young. The gender differences are mainly attributable to the variation in attitude towards nuclear power and concern about nuclear accidents. In the case of older people, interest was also a factor. Young people were not as interested in the issue. The most important factor in determining the attitude towards a final repository was the benefit it was expected to bring to the municipality. Moral and emotional aspects were also important. Risk played a relatively subordinate role. Social aspects were very important: those who frequently spoke with people who were positively disposed tended to be positive themselves, and vice versa for those who were negative. This factor could explain some of the gender differences in attitude. Attitudes in Oskarshamn were slightly more positive than in Oesthammar, probably due to the fact that the residents in Oskarshamn had a greater sense of participation in the municipality's decision in the matter. Information from SKB was also found to be an important factor for the differences in attitude between the municipalities. Eight percentage points more people had received information in Oskarshamn than in Oesthammar. The difference may be small, but it exists and does appear to be of some importance. Attitudes in Oskarshamn and Oesthammar continued to be much

  10. Geochemical simulation of the evolution of granitic rocks and clay minerals submitted to a temperature increase in the vicinity of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Fritz, B.; Kam, M.; Tardy, Y.

    1984-07-01

    The alteration of a granitic rock around a repository for spent nuclear fuel has been simulated considering the effect of an increase of temperature due to this kind of induced geothermal system. The results of the simulation have been interpreted in terms of mass transfer and volumic consequences. The alteration proceeds by dissolution of minerals (with an increase of the volumes of fissures and cracks) and precipitation of secondary miminerals as calcite and clay minerals particularly (with a decrease of the porosity). The increase of the temperature from 10 degrees C to about 100 degrees C will favour the alteration of the granitic rock around the repository by the solution filling the porosity. The rock is characterized by a very low fissure porosity and a consequent very low water velocity. This too, favours intense water rock interactions and production of secondary clays and the total possible mass transfer will decrease the porosity. A combination of these thermodynamic mass balance calculations with a kinetic approach of mineral dissolutions gives a first attempt to calibrate the modelling in the time scale: the decrease of porosity can be roughly estimated between 2 and 20% for 100,000 years. The particular problem of Na-bentonites behaviour in the proximate vicinity of the repository has been studied too. One must distinguish between two types of clay-water interactions: -within the rock around the repository, Na-bentonites should evolute with illitization in slighltly open system with low clay/water ratios, -within the repository itself, the clay reacts in a closed system for a long time with high clay/water ratios and a self-buffering effect should maintain the bentonite type. This chemical buffering effect is a positive point for the use of this clay as chemical barrier. (Author)

  11. Groundwater flow modeling of periods with temperate climate conditions for use in a safety assessment of a repository for spent nuclear fuel - 59154

    International Nuclear Information System (INIS)

    Joyce, Steven; Hartley, Lee; Simpson, Trevor

    2012-01-01

    Document available in abstract form only. Full text of publication follows: As a part of the license application for a final repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Company (SKB) has prepared a safety report (SR-Site) that assesses the long-term radiological safety after closure of a repository located at 500 m depth in the Forsmark area, c. 120 km north of Stockholm. The movement and composition of groundwater affect both the key pathways for radionuclide migration and the performance of engineered barriers, and hence are important issues that have to be considered and modelled as part of quantitative assessment calculations. This presentation describes the groundwater flow modelling studies that have been performed to represent the post-closure hydrogeological and hydrochemical situations during temperate climate conditions, and how these are used to support safety assessment calculations and arguments. The collation and implementation of onsite hydrogeological and hydrogeochemical data from the surface based site investigations at Forsmark are used as the basis for defining a reference case for the natural hydrogeological situation at the site (hydrogeological base case). Areas of uncertainty within the current site understanding and the engineered system are examined by a series of flow model variants

  12. Development of the Canadian used fuel repository engineered barrier system

    Energy Technology Data Exchange (ETDEWEB)

    Hatton, C., E-mail: chatton@nwmo.ca [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2015-07-01

    The Nuclear Waste Management Organization (NWMO) is responsible for the implementation of Adaptive Phased Management (APM), the federally-approved plan for the safe long-term management of Canada's used nuclear fuel. Under the APM plan, used nuclear fuel will ultimately be placed within a deep geological repository in a suitable rock formation. In implementing APM, the NWMO is committed to ensure consistency with international best practices in the development of its repository system, including any advances in technology. In 2012, the NWMO undertook an optimization study to look at both the design and manufacture of its engineered barriers. This study looked at current technologies for the design and manufacture of used fuel containers, placement technologies, repository design, and buffer and sealing systems, while taking into consideration the state of the art worldwide in repository design and acceptance. The result of that study is the current Canadian engineered barrier system, consisting of a 2.7 tonne used fuel container with a carbon-steel core, copper-coated surface and welded spherical heads. The used fuel container is encapsulated in a bentonite buffer box at the surface and then transferred underground. Once underground, the used fuel is placed into a repository room which is cut into the rock using traditional drill-and-blast technologies. This paper explains the logic for the selection of the container and sealing system design and the development of innovative technologies for their manufacture including the use of laser welding, cold spray and pulsed-electrodeposition copper coating for the manufacture of the used fuel container, isostatic presses for the production of the one-piece bentonite blocks, and slip-skid technologies for placement into the repository. (author)

  13. Development of the Canadian used fuel repository engineered barrier system

    International Nuclear Information System (INIS)

    Hatton, C.

    2015-01-01

    The Nuclear Waste Management Organization (NWMO) is responsible for the implementation of Adaptive Phased Management (APM), the federally-approved plan for the safe long-term management of Canada's used nuclear fuel. Under the APM plan, used nuclear fuel will ultimately be placed within a deep geological repository in a suitable rock formation. In implementing APM, the NWMO is committed to ensure consistency with international best practices in the development of its repository system, including any advances in technology. In 2012, the NWMO undertook an optimization study to look at both the design and manufacture of its engineered barriers. This study looked at current technologies for the design and manufacture of used fuel containers, placement technologies, repository design, and buffer and sealing systems, while taking into consideration the state of the art worldwide in repository design and acceptance. The result of that study is the current Canadian engineered barrier system, consisting of a 2.7 tonne used fuel container with a carbon-steel core, copper-coated surface and welded spherical heads. The used fuel container is encapsulated in a bentonite buffer box at the surface and then transferred underground. Once underground, the used fuel is placed into a repository room which is cut into the rock using traditional drill-and-blast technologies. This paper explains the logic for the selection of the container and sealing system design and the development of innovative technologies for their manufacture including the use of laser welding, cold spray and pulsed-electrodeposition copper coating for the manufacture of the used fuel container, isostatic presses for the production of the one-piece bentonite blocks, and slip-skid technologies for placement into the repository. (author)

  14. Ecosystem description of a drainage area - a strategy in biosphere descriptions during site investigations for a repository of spent nuclear fuel

    International Nuclear Information System (INIS)

    Lindborg, T.; Lofgren, A.

    2004-01-01

    During the next few years the Swedish Nuclear Fuel and Waste Management Co. (SKB) performs site investigations at two sites in Sweden for a future repository of spent nuclear fuel. Novel methods based on systems and landscape ecology are developed to understand and model the radionuclide flow in the biosphere using site specific data for a safety assessment. This work describes the strategy for development of a descriptive ecosystem model for the surface ecosystem. The site description is needed to: a) perform a safety assessment that describes and analyzes different scenarios for radionuclide releases into the ecosystem and possible pathways for dispersal or accumulation radionuclides in the ecosystem, b) detect changes caused by the construction of a repository, c) establish a baseline for detecting long-term effects of the repository. The description adopts a site-specific approach focusing on the quantification of the properties that will constitute the descriptive model. The aim is also to present the methodology for determining the properties, to describe the development of the framework for the descriptive ecosystem models by integrating use of different properties, and finally, to present vital data from other site descriptive models such as those for geology or hydrogeology. The safety assessment will use an approach, among other methods, where transport and accumulation of radionuclides will be modelled by quantifying biogeochemical pathways of matter. The descriptive ecosystem model applied to the site was therefore built to describe and quantify processes affecting i.e. turnover of matter in a drainage area. The conclusions from applying this approach was that by have estimating the flow of matter the ecological and physical constrains on the system reduces the potential variations in outcome of future states of the ecosystem and thus also reduces the uncertainties in estimating radionuclide flow and consequences to humans and the environment. (author)

  15. Prerequisites concerning SSI:s review of applications for an encapsulation facility and a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Oehlen, Elisabeth

    2006-09-01

    The report outlines some fundamental prerequisites concerning SSI:s review of SKB coming applications for an encapsulation facility (according to the act on nuclear activities) and for the complete final disposal system (according to the act on nuclear activities and the environmental code). The report summarize how the SSI look at the decision making process considering radiation protection requirements according to SSI:s regulations and general advices and earlier standpoints regarding SKB:s RandD-programme. The report also describe the present reviewing capacity of SSI and constitute therefore the basis for the planning of SSI:s review organisation in the prospect of coming applications on nuclear waste facilities (encapsulation facility and a deep disposal repository). It should be noted that the report reflects the present situation. Due to a number of factors as for example changes in SKB:s coming RandD-programme, future governmental decisions, adjustments of SSI:s financial resources or new facts in the case, will of course have an effect on how SSI finally will organise the review work. SSI:s home page will continuously be updated with the latest information in this respect

  16. INIS: Nuclear Grey Literature Repository

    International Nuclear Information System (INIS)

    Savić, Dobrica

    2016-01-01

    As one of the world's largest collections of published information on the peaceful uses of nuclear science and technology, INIS represents an extraordinary example of world cooperation. Currently, as INIS members, 130 countries and 24 international organizations share and allow access to their valuable nuclear information resources, preserving them for future generations and offering a freely available nuclear knowledge repository. Since its creation in 1970, INIS has collected and provided access to more than 3.8 million bibliographic references to publications, documents, technical reports, non-copyrighted documentation, and other grey literature, as well as over a million full texts. Public interest throughout the years in accessing the INIS Collection has been remarkable. This paper deals with the challenges faced by INIS in its endeavour to increase the use, accessibility, usability and expandability of its on-line repository. It also describes document collection, the features and characteristics of implementing a new search engine, as well as the lessons learned. (author)

  17. Nuclear fuels

    International Nuclear Information System (INIS)

    2008-01-01

    The nuclear fuel is one of the key component of a nuclear reactor. Inside it, the fission reactions of heavy atoms, uranium and plutonium, take place. It is located in the core of the reactor, but also in the core of the whole nuclear system. Its design and properties influence the behaviour, the efficiency and the safety of the reactor. Even if it represents a weak share of the generated electricity cost, its proper use represents an important economic stake. Important improvements remain to be made to increase its residence time inside the reactor, to supply more energy, and to improve its robustness. Beyond the economical and safety considerations, strategical questions have to find an answer, like the use of plutonium, the management of resources and the management of nuclear wastes and real technological challenges have to be taken up. This monograph summarizes the existing knowledge about the nuclear fuel, its behaviour inside the reactor, its limits of use, and its R and D tracks. It illustrates also the researches in progress and presents some key results obtained recently. Content: 1 - Introduction; 2 - The fuel of water-cooled reactors: aspect, fabrication, behaviour of UO 2 and MOX fuels inside the reactor, behaviour in loss of tightness situation, microscopic morphology of fuel ceramics and evolution under irradiation - migration and localisation of fission products in UOX and MOX matrices, modeling of fuels behaviour - modeling of defects and fission products in the UO 2 ceramics by ab initio calculations, cladding and assembly materials, pellet-cladding interaction, advanced UO 2 and MOX ceramics, mechanical behaviour of the fuel assembly, fuel during a loss of coolant accident, fuel during a reactivity accident, fuel during a serious accident, fuel management inside reactor cores, fuel cycle materials balance, long-term behaviour of the spent fuel, fuel of boiling water reactors; 3 - the fuel of liquid metal fast reactors: fast neutrons radiation

  18. The Adoption of Advanced Fuel Cycle Technology Under a Single Repository Policy

    International Nuclear Information System (INIS)

    Wilson, Paul

    2009-01-01

    Develops the tools to investigate the hypothesis that the savings in repository space associated with the implementation of advanced nuclear fuel cycles can result in sufficient cost savings to offset the higher costs of those fuel cycles.

  19. 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.

  20. Nuclear Fuel Reprocessing

    International Nuclear Information System (INIS)

    Simpson, Michael F.; Law, Jack D.

    2010-01-01

    This is a submission for the Encyclopedia of Sustainable Technology on the subject of Reprocessing Spent Nuclear Fuel. Nuclear reprocessing is the chemical treatment of spent fuel involving separation of its various constituents. Principally, it is used to recover useful actinides from the spent fuel. Radioactive waste that cannot be re-used is separated into streams for consolidation into waste forms. The first known application of nuclear reprocessing was within the Manhattan Project to recover material for nuclear weapons. Currently, reprocessing has a peaceful application in the nuclear fuel cycle. A variety of chemical methods have been proposed and demonstrated for reprocessing of nuclear fuel. The two most widely investigated and implemented methods are generally referred to as aqueous reprocessing and pyroprocessing. Each of these technologies is described in detail in Section 3 with numerous references to published articles. Reprocessing of nuclear fuel as part of a fuel cycle can be used both to recover fissionable actinides and to stabilize radioactive fission products into durable waste forms. It can also be used as part of a breeder reactor fuel cycle that could result in a 14-fold or higher increase in energy utilization per unit of natural uranium. Reprocessing can also impact the need for geologic repositories for spent fuel. The volume of waste that needs to be sent to such a repository can be reduced by first subjecting the spent fuel to reprocessing. The extent to which volume reduction can occur is currently under study by the United States Department of Energy via research at various national laboratories and universities. Reprocessing can also separate fissile and non-fissile radioactive elements for transmutation.

  1. Nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Nakano, H [Power Reactor and Nuclear Fuel Development Corp., Tokyo (Japan)

    1976-10-01

    It is expected that nuclear power generation will reach 49 million kW in 1985 and 129 million kW in 1995, and the nuclear fuel having to be supplied and processed will increase in proportion to these values. The technical problems concerning nuclear fuel are presented on the basis of the balance between the benefit for human beings and the burden on the human beings. Recently, especially the downstream of nuclear fuel attracts public attention. Enriched uranium as the raw material for light water reactor fuel is almost monopolized by the U.S., and the technical information has not been published for fear of the diversion to nuclear weapons. In this paper, the present situations of uranium enrichment, fuel fabrication, transportation, reprocessing and waste disposal and the future problems are described according to the path of nuclear fuel cycle. The demand and supply of enriched uranium in Japan will be balanced up to about 1988, but afterwards, the supply must rely upon the early establishment of the domestic technology by centrifugal separation method. No problem remains in the fabrication of light water reactor fuel, but for the fabrication of mixed oxide fuel, the mechanization of the production facility and labor saving are necessary. The solution of the capital risk for the construction of the second reprocessing plant is the main problem. Japan must develop waste disposal techniques with all-out efforts.

  2. Studies of neo-formed phases occurring during spent nuclear fuel dissolution in geological repository: influence of silicate ions

    International Nuclear Information System (INIS)

    Robit-Pointeau, V.

    2005-12-01

    Spent nuclear fuel alteration in deep storage conditions may proceed by local oxidising conditions at the fuel / water interface under influence of alpha irradiation. However, due to the strong redox buffer capacity of the near-field materials (especially the canister and the geological media), most of the near-field environment will remain reducing. Due to the relative high concentration in silica in such system, coffinite USiO 4 .n(H 2 O) may be a relevant phase to consider as it has been suggested from the natural analogues observations (Oklo). The aim of this work was to assess the relevance of coffinitisation of the spent fuel phenomena. The results of the experimental work contest the thermodynamic predictions. Instead of coffinite, a new U(IV)-Si phase has been observed in water simulating storage conditions. The thermodynamic data on coffinite validated by OECD are based on the average concentration of dissolved silica present in natural system containing uraninite and quartz. As the silica concentration in natural groundwaters is more probably controlled by minerals like chalcedony or silica gel, the coffinite present with uraninite in such systems, is probably not in equilibrium even in 2-billion years- old geological sites. Based on the results of this study, coffinitisation of the spent nuclear fuel in deep geological disposal is not anticipated to be a dominant short term process. (author)

  3. 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

  4. Nuclear fuels

    International Nuclear Information System (INIS)

    Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F.

    2009-01-01

    Fuel is one of the essential components in a reactor. It is within that fuel that nuclear reactions take place, i.e. fission of heavy atoms, uranium and plutonium. Fuel is at the core of the reactor, but equally at the core of the nuclear system as a whole. Fuel design and properties influence reactor behavior, performance, and safety. Even though it only accounts for a small part of the cost per kilowatt-hour of power provided by current nuclear power plants, good utilization of fuel is a major economic issue. Major advances have yet to be achieved, to ensure longer in-reactor dwell-time, thus enabling fuel to yield more energy; and improve ruggedness. Aside from economics, and safety, such strategic issues as use of plutonium, conservation of resources, and nuclear waste management have to be addressed, and true technological challenges arise. This Monograph surveys current knowledge regarding in-reactor behavior, operating limits, and avenues for R and D. It also provides illustrations of ongoing research work, setting out a few noteworthy results recently achieved. Content: 1 - Introduction; 2 - Water reactor fuel: What are the features of water reactor fuel? 9 (What is the purpose of a nuclear fuel?, Ceramic fuel, Fuel rods, PWR fuel assemblies, BWR fuel assemblies); Fabrication of water reactor fuels (Fabrication of UO 2 pellets, Fabrication of MOX (mixed uranium-plutonium oxide) pellets, Fabrication of claddings); In-reactor behavior of UO 2 and MOX fuels (Irradiation conditions during nominal operation, Heat generation, and removal, The processes involved at the start of irradiation, Fission gas behavior, Microstructural changes); Water reactor fuel behavior in loss of tightness conditions (Cladding, the first containment barrier, Causes of failure, Consequences of a failure); Microscopic morphology of fuel ceramic and its evolution under irradiation; Migration and localization of fission products in UOX and MOX matrices (The ceramic under irradiation

  5. Nuclear fuels

    Energy Technology Data Exchange (ETDEWEB)

    Beauvy, M.; Berthoud, G.; Defranceschi, M.; Ducros, G.; Guerin, Y.; Limoge, Y.; Madic, Ch.; Santarini, G.; Seiler, J.M.; Sollogoub, P.; Vernaz, E.; Guillet, J.L.; Ballagny, A.; Bechade, J.L.; Bonin, B.; Brachet, J.Ch.; Delpech, M.; Dubois, S.; Ferry, C.; Freyss, M.; Gilbon, D.; Grouiller, J.P.; Iracane, D.; Lansiart, S.; Lemoine, P.; Lenain, R.; Marsault, Ph.; Michel, B.; Noirot, J.; Parrat, D.; Pelletier, M.; Perrais, Ch.; Phelip, M.; Pillon, S.; Poinssot, Ch.; Vallory, J.; Valot, C.; Pradel, Ph.; Bonin, B.; Bouquin, B.; Dozol, M.; Lecomte, M.; Vallee, A.; Bazile, F.; Parisot, J.F.; Finot, P.; Roberts, J.F

    2009-07-01

    Fuel is one of the essential components in a reactor. It is within that fuel that nuclear reactions take place, i.e. fission of heavy atoms, uranium and plutonium. Fuel is at the core of the reactor, but equally at the core of the nuclear system as a whole. Fuel design and properties influence reactor behavior, performance, and safety. Even though it only accounts for a small part of the cost per kilowatt-hour of power provided by current nuclear power plants, good utilization of fuel is a major economic issue. Major advances have yet to be achieved, to ensure longer in-reactor dwell-time, thus enabling fuel to yield more energy; and improve ruggedness. Aside from economics, and safety, such strategic issues as use of plutonium, conservation of resources, and nuclear waste management have to be addressed, and true technological challenges arise. This Monograph surveys current knowledge regarding in-reactor behavior, operating limits, and avenues for R and D. It also provides illustrations of ongoing research work, setting out a few noteworthy results recently achieved. Content: 1 - Introduction; 2 - Water reactor fuel: What are the features of water reactor fuel? 9 (What is the purpose of a nuclear fuel?, Ceramic fuel, Fuel rods, PWR fuel assemblies, BWR fuel assemblies); Fabrication of water reactor fuels (Fabrication of UO{sub 2} pellets, Fabrication of MOX (mixed uranium-plutonium oxide) pellets, Fabrication of claddings); In-reactor behavior of UO{sub 2} and MOX fuels (Irradiation conditions during nominal operation, Heat generation, and removal, The processes involved at the start of irradiation, Fission gas behavior, Microstructural changes); Water reactor fuel behavior in loss of tightness conditions (Cladding, the first containment barrier, Causes of failure, Consequences of a failure); Microscopic morphology of fuel ceramic and its evolution under irradiation; Migration and localization of fission products in UOX and MOX matrices (The ceramic under

  6. Nuclear fuel

    International Nuclear Information System (INIS)

    Azevedo, J.B.L. de.

    1980-01-01

    All stages of nuclear fuel cycle are analysed with respect to the present situation and future perspectives of supply and demand of services; the prices and the unitary cost estimation of these stages for the international fuel market are also mentioned. From the world resources and projections of uranium consumption, medium-and long term analyses are made of fuel availability for several strategies of use of different reactor types. Finally, the cost of nuclear fuel in the generation of electric energy is calculated to be used in the energetic planning of the electric sector. (M.A.) [pt

  7. Framework for detailed studies on the construction and operation of repositories for spent nuclear fuel; Ramprogram foer detaljundersoekningar vid uppfoerande och drift av slutfoervar foer anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    2010-10-15

    This report presents a programme for the detailed investigations planned to be applied during construction and operation of the repository for spent nuclear fuel at Forsmark. The report is part of SKB's application according to the Nuclear Activities Act. The detailed investigations shall provide relevant data on and site-descriptive models for the bedrock, soil deposits and eco-system of the site in order to facilitate a step-wise design and construction of the final repository. This shall be implemented in a manner that all demands on long-term safety are fulfilled, including accurate documentation of the construction work, and so that assessments of the environmental impact of the repository can be made. For the operational phase, the detailed investigations should also provide support to the deposition process with related decisions, thereby enabling fulfilment of the design premises for the siting and construction of deposition tunnels and deposition holes, as well as for deposition of canisters, and for the subsequent backfilling and closure of the repository. The Observational Method will be applied during the construction of the repository. This method entails establishing in advance acceptable limits of behaviour regarding selected geoscientific parameters and preparing a plan with measures to keep the outcome within these limits. Predictions of expected rock properties are established for each tunnel section. The outcome after excavation is compared with the acceptable range of outcomes. Information from detailed characterization will be of essential importance for application of the Observational Method and for adapting the repository to the prevailing rock properties. SKB has for the past several decades developed methods for site characterisation, applying both above- and underground investigation techniques. Experiences from this work, put into practice during the site investigations, has resulted in a solid knowledge and understanding of the

  8. 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.)

  9. SKI and SSI's recommendations to the government concerning long-term responsibility after closure of a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Paeivioe Jonsson, Josefin

    2008-01-01

    Many activities will cease at the closure of a repository, but not responsibilities. The candidate municipalities in Sweden expressed concern about who will take over after the implementer is released from responsibility for the facility. The government thus commissioned SKI (Swedish Nuclear Power Inspectorate) and SSI (Swedish Radiation Protection Authority) to review the legal obligations of institutional players as laid out today in legislation in Sweden. After closure of the repository in about 100 years there will be post-closure monitoring, possibly for a few hundred years. This will be a part of the conditions on SKB (Swedish Nuclear Fuel and Waste Management Company) which will be set out at the time. Some activities will end at the closure of the facility but monitoring and safeguards obligations may continue. The exact nature of this monitoring and safeguard work needs to be discussed and agreed upon. With the proposed approach most of the liabilities rest with the state in the long term, the waste producers only have liabilities in the short term but their decisions could have big impacts on long term liabilities

  10. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Models and data for the repository system 2012. Parts 1 and 2

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2013-09-15

    TURVA-2012 is Posiva Oy's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a KBS-3V spent nuclear fuel repository. The present report is a key element of the TURVA-2012 report portfolio and has the objective of documenting the models, data, assumptions and treatment of uncertainties in the context of the safety case. This report is the main link between the safety case and the engineered barrier design and their development as well as between the safety case and the Olkiluoto site investigations. This report focuses on the models and data used in Performance Assessment and in Assessment of Radionuclide Release Scenarios for the Repository System, which are key reports of TURVA-2012. Models and data for the surface environment are discussed in dedicated biosphere modelling and data reports. This report describes the methodology for the identification of key models and data as well as the modelling chain with input and output data connections. Models and data are presented for all components of the repository system: spent nuclear fuel, canister, buffer, backfill, closure, underground openings and geosphere. The report is structured so that the modelling of external processes is discussed first, followed by the models and data used in the performance assessment to address the evolution of the repository system and finally the models and data used in the radionuclide release and transport assessment. Confidence in the models and data and the treatment of uncertainties are also discussed. The present report traces the path from data production to implementation in the modelling chain. During the compilation of the report, some discrepancies between the sources of data and data usage, as well as some inconsistencies in model assumptions, were identified. The consequences of the potentially most significant of these were checked through additional radionuclide release and transport

  11. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Models and data for the repository system 2012. Parts 1 and 2

    International Nuclear Information System (INIS)

    2013-09-01

    TURVA-2012 is Posiva Oy's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a KBS-3V spent nuclear fuel repository. The present report is a key element of the TURVA-2012 report portfolio and has the objective of documenting the models, data, assumptions and treatment of uncertainties in the context of the safety case. This report is the main link between the safety case and the engineered barrier design and their development as well as between the safety case and the Olkiluoto site investigations. This report focuses on the models and data used in Performance Assessment and in Assessment of Radionuclide Release Scenarios for the Repository System, which are key reports of TURVA-2012. Models and data for the surface environment are discussed in dedicated biosphere modelling and data reports. This report describes the methodology for the identification of key models and data as well as the modelling chain with input and output data connections. Models and data are presented for all components of the repository system: spent nuclear fuel, canister, buffer, backfill, closure, underground openings and geosphere. The report is structured so that the modelling of external processes is discussed first, followed by the models and data used in the performance assessment to address the evolution of the repository system and finally the models and data used in the radionuclide release and transport assessment. Confidence in the models and data and the treatment of uncertainties are also discussed. The present report traces the path from data production to implementation in the modelling chain. During the compilation of the report, some discrepancies between the sources of data and data usage, as well as some inconsistencies in model assumptions, were identified. The consequences of the potentially most significant of these were checked through additional radionuclide release and transport calculations

  12. 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

  13. Actual Implementation of a Spent Nuclear Fuel Repository in Sweden: Seizing Opportunities. Synthesis of the FSC National Workshop and Community Visit - Oesthammar, Sweden 4-6 May 2011

    International Nuclear Information System (INIS)

    2012-01-01

    The 8. Forum on Stakeholder Confidence (FSC) National Workshop and Community Visit was held 4-6 May 2011 in Gimo (Oesthammar), Sweden. The Swedish National Council for Nuclear Waste, Oesthammar municipality, the Swedish Nuclear Fuel and Waste Management Company (SKB) and the Swedish Radiation Safety Authority (SSM) assisted the FSC in the organisation and logistics and provided financial support for the event. The central theme of the workshop was 'Actual Implementation of a Spent Nuclear Fuel Repository: Seizing Opportunities'. The three day event took place in Gimo, a locality of Oesthammar. There were 90 participants from 13 countries who included representatives of local, regional and national government, civil society organisations and environmental groups, universities, waste management agencies and regulatory authorities. In all, 63 persons participated from Sweden. The workshop provided an overview of the different aspects involved in the Swedish nuclear waste management programme from different viewpoints, mainly those of the implementer SKB, the regulator SSM, the two municipalities involved - Oskarshamn and Oesthammar - and civil society organisations. The visions for the future of the two municipalities were presented by local representatives on the first evening. The second day, after a brief historical overview of waste management, the Swedish funding system and how it contributes to the participation of local and regional stakeholders was addressed as well as the role and perspective of different actors in the new licensing phase for the repository. After a session on the role of dialogue, information exchange and transparency throughout the process, participants at eight round tables discussed the concept of transparency and how it could be affected in the repository licensing phase. The third day, presentations and round table discussions addressed the specific aspects of consultation through the Environmental Impact Assessment (EIA) and economic

  14. 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

  15. 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)

  16. A global nuclear waste repository

    Science.gov (United States)

    Lin, Wunan

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

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

    International Nuclear Information System (INIS)

    Woerman, A.; Shulan Xu

    2000-01-01

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

  18. Spent nuclear fuel storage

    International Nuclear Information System (INIS)

    Romanato, Luiz Sergio

    2005-01-01

    When a country becomes self-sufficient in part of the nuclear cycle, as production of fuel that will be used in nuclear power plants for energy generation, it is necessary to pay attention for the best method of storing the spent fuel. Temporary storage of spent nuclear fuel is a necessary practice and is applied nowadays all over the world, so much in countries that have not been defined their plan for a definitive repository, as well for those that already put in practice such storage form. There are two main aspects that involve the spent fuels: one regarding the spent nuclear fuel storage intended to reprocessing and the other in which the spent fuel will be sent for final deposition when the definitive place is defined, correctly located, appropriately characterized as to several technical aspects, and licentiate. This last aspect can involve decades of studies because of the technical and normative definitions at a given country. In Brazil, the interest is linked with the storage of spent fuels that will not be reprocessed. This work analyses possible types of storage, the international panorama and a proposal for future construction of a spent nuclear fuel temporary storage place in the country. (author)

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

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2000-12-01

    In order to dispose of the spent nuclear fuel in a safe manner, SKB plans to site a deep repository and an encapsulation plant with associated canister fabrication and transportation system. After an integrated evaluation of feasibility studies and other material, SKB will proceed with investigations of the rock and studies regarding establishment of the deep disposal system in the municipality of Oskarshamn or in Northern Uppland. The plans also include further study of the prospects for a deep repository in the municipality of Nykoeping. In the municipality of Oskarshamn, SKB plans further studies of a siting of the deep repository at Simpevarp. There SKB wants to initiate site investigations with test drilling. For the encapsulation plant, SKB wants to continue studying a siting at CLAB. In Northern Uppland, SKB plans to study two siting alternatives for the deep repository. One is Forsmark in the municipality of Oesthammar, where SKB wants to initiate a site investigation with test drilling. The other is Tierp north of Skutskaer, where SKB intends to start test drilling in an area north of Tierp. First, however, a suitable drilling area with possible transport solutions needs to be defined. This alternative requires the participation of the municipalities of both Tierp and Aelvkarleby. A siting of the encapsulation plant in Northern Uppland will also be studied. For the municipality of Nykoeping, SKB plans to conduct a new safety assessment for the Fjaellveden area, based on data from previous investigations as well as additional studies of how a deep repository could be arranged. SKB will thereby gather data from yet another geographic and geological region beyond those that are prioritized. No test drilling is planned in Nykoeping. The goal of the site investigation phase is to obtain all permits needed to build the planned facilities. It will take an estimated 7 - 8 years to assemble the requisite supporting material, carry out consultations, compile siting

  20. Preservation of information about the repository for spent nuclear fuels - proposal for action plan; Bevarande av information om slutfoervar foer anvaent kaernbraensle - foerslag till handlingsplan

    Energy Technology Data Exchange (ETDEWEB)

    Bowen-Schrire, Monica; Eckerhall, Daniel; Jander, Hans; Waniewska, Katarina (Vattenfall Power Consultant AB, Stockholm (Sweden))

    2008-10-15

    This report is a proposal for an action plan with the ultimate aim of ensuring that information about the repository for spent nuclear fuel can be preserved and transferred for future generations. The purpose of the proposal for an action plan is to present ideas on tangible measures and guidelines for information preservation and transfer, in the short and long term. The report deals with a number of aspects relating to information preservation as well as risks that can lead to the loss of important information. The proposal for an action plan is based on reasoning about these subjects. The main emphasis is on measures that need to be implemented in the near future to ensure that successive and direct information transfer is handled in a suitable manner. It is suggested that the following measures should be implemented within a five-year period: - Designate a person responsible for information preservation. - Work out guidelines for information preservation and transfer. - Form a network with other organizations in Sweden. - Initiate a dialogue with other countries, especially USA and France. - Participate in seminars, conferences and workgroups on an international level within the IAEA and NEA. In a longer time perspective the following measures should also be implemented: - Implement guidelines for information preservation and transfer. - Document the archiving system. - Establish a communication plan. - Archive information about the repository. - Keep the action plan up to date

  1. Presentation of safety after closure of the repository for spent nuclear fuel. Main report of the project SR-Site. Part I; Redovisning av saekerhet efter foerslutning av slutfoervaret foer anvaent kaernbraensle. Huvudrapport fraan projekt SR-Site. Del I

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    The purpose of the safety assessment SR-Site is to investigate whether a safe repository for spent nuclear fuel by KBS-3 type can be constructed at Forsmark in Oesthammar in Sweden. The location of the Forsmark has been selected based on results of several surveys from surface conditions at depth in Forsmark and in Laxemar in Oskarshamn. The choice of location is not justified in SR-Site Report, but in other attachments to SKB's permit applications. SR-Site Report is an important part of SKB's permit applications to construct and operate a repository for spent nuclear fuel at Forsmark in Oesthammar. The purpose of the report in the applications is to show that a repository at Forsmark is safe after closure

  2. Presentation of safety after closure of the repository for spent nuclear fuel. Main report of the project SR-Site. Part II; Redovisning av saekerhet efter foerslutning av slutfoervaret foer anvaent kaernbraensle. Huvudrapport fraan projekt SR-Site. Del II

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    The purpose of the safety assessment SR-Site is to investigate whether a safe repository for spent nuclear fuel by KBS-3 type can be constructed at Forsmark in Oesthammar in Sweden. The location of the Forsmark has been selected based on results of several surveys from surface conditions at depth in Forsmark and in Laxemar in Oskarshamn. The choice of location is not justified in SR-Site Report, but in other attachments to SKB's permit applications. SR-Site Report is an important part of SKB's permit applications to construct and operate a repository for spent nuclear fuel at Forsmark in Oesthammar. The purpose of the report in the applications is to show that a repository at Forsmark is safe after closure

  3. Presentation of safety after closure of the repository for spent nuclear fuel. Main report of the project SR-Site. Part III; Redovisning av saekerhet efter foerslutning av slutfoervaret foer anvaent kaernbraensle. Huvudrapport fraan projekt SR-Site. Del III

    Energy Technology Data Exchange (ETDEWEB)

    2011-07-01

    The purpose of the safety assessment SR-Site is to investigate whether a safe repository for spent nuclear fuel by KBS-3 type can be constructed at Forsmark in Oesthammar in Sweden. The location of the Forsmark has been selected based on results of several surveys from surface conditions at depth in Forsmark and in Laxemar in Oskarshamn. The choice of location is not justified in SR-Site Report, but in other attachments to SKB's permit applications. SR-Site Report is an important part of SKB's permit applications to construct and operate a repository for spent nuclear fuel at Forsmark in Oesthammar. The purpose of the report in the applications is to show that a repository at Forsmark is safe after closure

  4. Safeguarding of spent fuel conditioning and disposal in geological repositories

    International Nuclear Information System (INIS)

    Forsstroem, H.; Richter, B.

    1997-01-01

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

  5. The relevance of axial burn-up profiles for the criticality safety analysis of spent nuclear fuel in a final repository

    International Nuclear Information System (INIS)

    Kilger, R.; Gmal, B.; Moser, E.F.

    2008-01-01

    Due to inhomogeneous neutron flux and moderator density distributions in the reactor core, the burn-up of a nuclear fuel assembly is not homogeneous but shows an axial distribution, typically with lower partial burn-up and thus higher remaining reactivity at the fuel ends in particular at the assembly top end. Beyond a burn-up of about 15 to 20 GWd/tHM, the multiplication factor K of the whole assembly is dominated by this lower-burnt end regions, and is usually higher than for assuming a homogeneous uniform distribution of the averaged burn-up. This behaviour commonly referred to as positive ''end effect'' is well known in burn-up credit considerations for transportation and storage casks and is being investigated also in the context of criticality analyses for final disposition of spent nuclear fuel. Sign and value of the end effect depend on several parameters. Based on a generic model one may not conclude that criticality in a final repository is a likely or expected event, but nevertheless it draws the attention to the fact that criticality is not excluded per se but has to be considered in the analysis and probably has to be encountered by certain appropriate measures, maybe e.g. by limitation of the amount of fissile material inside one single cask, or a rigorous prove for prevention of water ingress. The authors also conclude that the higher partial reactivity of the fuel ends has to be accounted for carefully in more realistic analyses of post-closure scenarios with respect to criticality safety.

  6. Chemical risks from nuclear waste repositories

    International Nuclear Information System (INIS)

    Persson, L.

    1988-01-01

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

  7. Integrating repositories with fuel cycles: The airport authority model

    International Nuclear Information System (INIS)

    Forsberg, C.

    2012-01-01

    The organization of the fuel cycle is a legacy of World War II and the cold war. Fuel cycle facilities were developed and deployed without consideration of the waste management implications. This led to the fuel cycle model of a geological repository site with a single owner, a single function (disposal), and no other facilities on site. Recent studies indicate large economic, safety, repository performance, nonproliferation, and institutional incentives to collocate and integrate all back-end facilities. Site functions could include geological disposal of spent nuclear fuel (SNF) with the option for future retrievability, disposal of other wastes, reprocessing with fuel fabrication, radioisotope production, other facilities that generate significant radioactive wastes, SNF inspection (navy and commercial), and related services such as SNF safeguards equipment testing and training. This implies a site with multiple facilities with different owners sharing some facilities and using common facilities - the repository and SNF receiving. This requires a different repository site institutional structure. We propose development of repository site authorities modeled after airport authorities. Airport authorities manage airports with government-owned runways, collocated or shared public and private airline terminals, commercial and federal military facilities, aircraft maintenance bases, and related operations - all enabled and benefiting the high-value runway asset and access to it via taxi ways. With a repository site authority the high value asset is the repository. The SNF and HLW receiving and storage facilities (equivalent to the airport terminal) serve the repository, any future reprocessing plants, and others with needs for access to SNF and other wastes. Non-public special-built roadways and on-site rail lines (equivalent to taxi ways) connect facilities. Airport authorities are typically chartered by state governments and managed by commissions with members

  8. Integrating repositories with fuel cycles: The airport authority model

    Energy Technology Data Exchange (ETDEWEB)

    Forsberg, C. [Massachusetts Inst. of Technology, 77 Massachusetts Avenue, Cambridge, MA 02139-4307 (United States)

    2012-07-01

    The organization of the fuel cycle is a legacy of World War II and the cold war. Fuel cycle facilities were developed and deployed without consideration of the waste management implications. This led to the fuel cycle model of a geological repository site with a single owner, a single function (disposal), and no other facilities on site. Recent studies indicate large economic, safety, repository performance, nonproliferation, and institutional incentives to collocate and integrate all back-end facilities. Site functions could include geological disposal of spent nuclear fuel (SNF) with the option for future retrievability, disposal of other wastes, reprocessing with fuel fabrication, radioisotope production, other facilities that generate significant radioactive wastes, SNF inspection (navy and commercial), and related services such as SNF safeguards equipment testing and training. This implies a site with multiple facilities with different owners sharing some facilities and using common facilities - the repository and SNF receiving. This requires a different repository site institutional structure. We propose development of repository site authorities modeled after airport authorities. Airport authorities manage airports with government-owned runways, collocated or shared public and private airline terminals, commercial and federal military facilities, aircraft maintenance bases, and related operations - all enabled and benefiting the high-value runway asset and access to it via taxi ways. With a repository site authority the high value asset is the repository. The SNF and HLW receiving and storage facilities (equivalent to the airport terminal) serve the repository, any future reprocessing plants, and others with needs for access to SNF and other wastes. Non-public special-built roadways and on-site rail lines (equivalent to taxi ways) connect facilities. Airport authorities are typically chartered by state governments and managed by commissions with members

  9. Evolution of repository and waste package designs for Yucca Mountain disposal system for spent nuclear fuel and high-level radioactive waste

    International Nuclear Information System (INIS)

    Rechard, Rob P.; Voegele, Michael D.

    2014-01-01

    This paper summarizes the evolution of the engineered barrier design for the proposed Yucca Mountain disposal system. Initially, the underground facility used a fairly standard panel and drift layout excavated mostly by drilling and blasting. By 1993, the layout of the underground facility was changed to accommodate construction by a tunnel boring machine. Placement of the repository in unsaturated zone permitted an extended period without backfilling; placement of the waste package in an open drift permitted use of much larger, and thus hotter packages. Hence in 1994, the underground facility design switched from floor emplacement of waste in small, single walled stainless steel or nickel alloy containers to in-drift emplacement of waste in large, double-walled containers. By 2000, the outer layer was a high nickel alloy for corrosion resistance and the inner layer was stainless steel for structural strength. Use of large packages facilitated receipt and disposal of high volumes of spent nuclear fuel. In addition, in-drift package placement saved excavation costs. Options considered for in-drift emplacement included different heat loads and use of backfill. To avoid dripping on the package during the thermal period and the possibility of localized corrosion, titanium drip shields were added for the disposal drifts by 2000. In addition, a handling canister, sealed at the reactor to eliminate further handling of bare fuel assemblies, was evaluated and eventually adopted in 2006. Finally, staged development of the underground layout was adopted to more readily adjust to changes in waste forms and Congressional funding. - Highlights: • Progression of events associated with repository design to accommodate tunnel boring machine and in-drift waste package emplacement are discussed. • Change in container design from small, single-layered stainless steel vessel to large, two-layered nickel alloy vessel is discussed. • The addition of drip shield to limit the

  10. 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

  11. Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, Robert P.

    2014-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2008 of the performance of a repository for spent nuclear fuel and high-level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment-specific laboratory experiments, in-situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site-specific characterization. Because the relationship is important to understanding the evolution of the Yucca Mountain Project, the tabulation also shows the interaction between four broad categories of political bodies and government agencies/institutions: (a) technical milestones of the implementing institutions, (b) development of the regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives and decisions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste.

  12. Criticality issues with highly enriched fuels in a repository environment

    International Nuclear Information System (INIS)

    Taylor, L.L.; Sanchez, L.C.; Rath, J.S.

    1998-03-01

    This paper presents preliminary analysis of a volcanic tuff repository containing a combination of low enrichment commercial spent nuclear fuels (SNF) and DOE-owned SNF packages. These SNFs were analyzed with respect to their criticality risks. Disposal of SNF packages containing significant fissile mass within a geologic repository must comply with current regulations relative to criticality safety during transportation and handling within operational facilities. However, once the repository is closed, the double contingency credits for criticality safety are subject to unremediable degradation, (e.g., water intrusion, continued presence of neutron absorbers in proximity to fissile material, and fissile material reconfiguration). The work presented in this paper focused on two attributes of criticality in a volcanic tuff repository for near-field and far-field scenarios: (1) scenario conditions necessary to have a criticality, and (2) consequences of a nuclear excursion that are components of risk. All criticality consequences are dependent upon eventual water intrusion into the repository and subsequent breach of the disposal package. Key criticality parameters necessary for a critical assembly are: (1) adequate thermal fissile mass, (2) adequate concentration of fissile material, (3) separation of neutron poison from fissile materials, and (4) sufficient neutron moderation (expressed in units of moderator to fissile atom ratios). Key results from this study indicated that the total energies released during a single excursion are minimal (comparable to those released in previous solution accidents), and the maximum frequency of occurrence is bounded by the saturation and temperature recycle times, thus resulting in small criticality risks

  13. Multiphase flow in the geosphere around a repository for spent nuclear fuels. Inventory of the present knowledge; Flerfasfloede i geosfaeren kring ett foervar foer utbraent kaernbraensle. Inventering av kunskapslaeget

    Energy Technology Data Exchange (ETDEWEB)

    Aalen, Bengt [Bergab, Goeteborg (Sweden)

    2004-10-01

    Important quantities of gas can form in an underground repository for nuclear wastes. Gas can be formed through: corroding metals; water and certain organic substances that undergo radiolysis; organic material degrading through microbial activity. The last point is of concern mainly for intermediate-level wastes, which can hold large amounts of organic materials. The first point is the main process for high-level wastes. The gas could transport radioactive substances through the buffer and the geosphere into the biosphere, or affect the performance of the repository in a negative way. The present report gives a review of the knowledge about two-phase flow in connection with deep geologic repositories for spent nuclear fuel.

  14. Kinetic modelling of bentonite - canister interaction. Implications for Cu, Fe and Pb corrosion in a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Wersin, P.; Bruno, J.; Spahiu, K.

    1993-06-01

    The chemical corrosion of three potential canister materials, Fe, Cu, and Pb is reviewed in terms of their thermodynamic and kinetic behavior in a repository. Thermodynamic predictions which are compatible with sedimentological observations indicate that for all three metals, chemical corrosion is expected at any time in a repository. From the kinetic information obtained by experimental and archeological data, long-term corrosion rates are assessed. In the case of Fe, the selected data allow extrapolation to repository conditions with a tolerable degree of uncertainty except for the possible effect of local corrosion in the initial oxic phase, For the other two metals, the scarcity of consistent experimental and archeological data limits the feasibility of this approach. In view of this shortcoming, a kinetic, single-box model, based on the STEADYQL code, is presented for quantitative prediction of long-term canister-bentonite interaction. The model is applied to the corrosion of Cu under anoxic conditions and upper and lower limits of corrosion rates are derived. The possibilities of extending this single-box model to a multi-box, diffusion-extended version are discussed. Finally, further potentials of STEADYQL for future applications of near field modelling are highlighted. 32 refs

  15. Limits to the use of highly compacted bentonite as a deterrent for microbiologically influenced corrosion in a nuclear fuel waste repository

    Science.gov (United States)

    Stroes-Gascoyne, Simcha; Hamon, Connie J.; Maak, Peter

    Recent studies have suggested that microbial activity in highly compacted bentonite (⩾1600 kg/m 3) is severely suppressed. Therefore, it appears that the dry density of emplaced bentonite barriers in a geological repository for nuclear waste may be tailored such that a microbiologically unfavorable environment can be created adjacent to used fuel containers. This would ensure that microbiologically influenced corrosion is a negligible contributor to the overall corrosion process. However, this premise is valid only as long as the emplaced bentonite maintains a uniform high dry density (⩾1600 kg/m 3) because it has been shown that high dry density only suppresses microbial activity but not necessarily eliminates the viable microbial population in bentonite. In a repository, a reduction in the dry density of highly compacted bentonite may occur at a number of interface locations, such as placement gaps, contact regions with materials of different densities and contact points with water-carrying fractures in the rock. Experiments were carried out in our laboratory to examine the effects of a reduction in dry density (from 1600 kg/m 3 to about 1000 kg/m 3) on the recovery of microbial culturability in compacted bentonite. Results showed that upon expansion of compacted bentonite into a void, the resulting reduction in dry density stimulated or restored culturability of indigenous microbes. In a repository this would increase the possibility of in situ activity, which might be detrimental for the longevity of waste containers. Reductions in dry density, therefore, should be minimized or eliminated by adequate design and placement methods of compacted bentonite. Materials compliance models can be used to determine the required as-placed dry densities of bentonite buffer and gap fillings to achieve specific targets for long-term equilibrium dry densities for various container placement room designs. Locations where flowing fractures could be in contact with highly

  16. 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

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

    Czech Academy of Sciences Publication Activity Database

    Kaláb, Zdeněk; Šílený, Jan; Lednická, Markéta

    2017-01-01

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

  18. Hydrochemical patterns of a small lake and a stream in an uplifting area proposed as a repository site for spent nuclear fuel, Forsmark, Sweden

    Science.gov (United States)

    Rönnback, Pernilla; Åström, Mats

    2007-10-01

    SummaryThe overall aim of this study was to increase the understanding of the chemical dynamics of small catchments. The focus was on a small oligotropic lake and its major inflow stream in an uplifting area in eastern Sweden (Forsmark) proposed as a repository site for spent nuclear fuel. The hydrochemical sampling campaign lasted for nearly 4 years with sample collection monthly to semi-monthly, and continuous flow measurements carried out over the last 20 months. All this was done as part of the Swedish Nuclear Fuel and Waste Management Company's (SKBs) Site Investigation Programme. The major findings were: (1) as a result of the calcareous overburden caused by redistributed Paleozoic deposits, pH and the Ca and HCO3- concentrations were relatively high in both the stream and lake throughout the period, (2) limnic primary production resulted in decreased concentrations of Ca, HCO3-, NH4+, NO3- and Si, and increased pH and concentrations of chlorophyll a, O 2, DON, POC, PON and POP in the lake in summer, while in other seasons (in winter in particular) when the production was minimal or non-existent the concentrations in the lake and the inflow stream were similar, (3) intrusion of brackish-water resulted in moderately to strongly increased concentrations of Cl -, Na, Mg, Br -, SO42-, K and Sr in the lake: the ratio versus Cl - were for Na and Br - always similar to those in sea water, for Mg and SO42- similar to those in sea water at elevated Cl - concentrations (>3 mM), while K and Sr always occurred in relative excess as compared to sea water, (4) high U concentrations in both the stream and the lake was derived most likely from reduced U-minerals in the overburden and was predicted to be carried to >90% in the form of calcium uranyl carbonate, in a model in which colloidal Fe and Al oxyhydroxides were not considered, (5) the rare earth elements (REEs) had similar concentrations and fractionation patterns in the stream and lake, unlike those found in the

  19. 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

  20. Limits to the use of highly compacted bentonite as a deterrent for microbially influenced corrosion in a nuclear fuel waste repository

    International Nuclear Information System (INIS)

    Stroes-Gascoyne, Simcha; Hamon, Connie J.; Maak, Peter

    2010-01-01

    Highly compacted bentonite-based sealing materials are being developed for use in future geological repositories for nuclear fuel waste. Such materials would ensure a diffusion-controlled hydrology and additionally form a sorption barrier against radionuclide migration after container breach. Due to some inherent physical characteristics, such as low water activity (a w ), small pores and high swelling pressure, an additional role of highly compacted bentonite may be the elimination of significant microbial activity near used fuel containers, which would reduce the occurrence of microbially influenced corrosion (MIC) to insignificant levels. Several recent studies have examined the indigenous microbial populations in compacted bentonite and the factors that control microbial activity in such environments. Laboratory experiments with Wyoming MX-80 bentonite plugs, compacted to dry densities (DD's) of 0.8 to 2.0 g/cm 3 , and infiltrated with sterile distilled deionised water were carried out. At DD's of 0.8 and 1.3 g/cm 3 , culturability of heterotrophic aerobic bacteria increased by up to four orders of magnitude above back-ground levels. Anaerobic heterotrophic bacteria and SRB did not increase significantly above background levels in any of the tests. At higher DD's all culturability remained at, or fell below, the background levels. However, even at the highest DD tested, some culturability remained and viability was only mildly affected by high DD's. Therefore, the potential for increased microbial activity exist if a substantial reduction in DD of bentonite were to occur in a repository. The microbes that survive in dry as-purchased or highly compacted bentonite appear to be largely spore-forming organisms. Chi Fru and Athar (2008) studied the bacterial colonization of compacted MX-80 bentonite from the surrounding granitic groundwater population, at various temperature ranges. Results suggested that high temperature rather than high DD

  1. Some reflections on human intrusion into a nuclear waste repository

    International Nuclear Information System (INIS)

    Westerlind, M.

    2002-01-01

    This paper summarises some of the Swedish nuclear regulators' requirements and views related to intrusion into a repository for spent nuclear fuel, in the post-closure phase. The focus is however on experiences from the interaction with various stakeholders in the Swedish process for siting a repository. It is recognised that intrusion is not a major concern but that it is regularly raised in the debate, often in connection with issues related to retrievability. It is pointed out that more attention should be paid to the repository performance after an intrusion event, both in safety assessments and in communication with stakeholders, and not only address the immediate impacts to intruders. It is believed that international co-operation would be useful for developing methodologies for defining intrusion scenarios. (author)

  2. Low temperature spent fuel oxidation under tuff repository conditions

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1985-01-01

    The Nevada Nuclear Waste Storage Investigations Project is studying the suitability of tuffaceous rocks at Yucca Mountain, Nye County, Nevada, for high level waste disposal. The oxidation state of LWR spent fuel in a tuff repository may be a significant factor in determining its ability to inhibit radionuclide migration. Long term exposure at low temperatures to the moist air expected in a tuff repository is expected to increase the oxidation state of the fuel. A program is underway to determine the spent fuel oxidation mechanisms which might be active in a tuff repository. Initial work involves a series of TGA experiments to determine the effectiveness of the technique and to obtain preliminary oxidation data. Tests were run at 200 0 C and 225 0 C for as long as 720 hours. Grain boundary diffusion appears to open up a greater surface area for oxidation prior to onset of bulk diffusion. Temperature strongly influences the oxidation rates. The effect of moisture is small but readily measurable. 25 refs., 7 figs., 4 tabs

  3. Predicting spent fuel oxidation states in a tuff repository

    International Nuclear Information System (INIS)

    Einziger, R.E.; Woodley, R.E.

    1987-01-01

    Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the tuffaceous rocks at Yucca Mountain as a waste repository for spent fuel disposal. The oxidation state of the LWR spent fuel in the moist air environment of a tuff repository could be a significant factor in determining its leaching and dissolution characteristics. Predictions as to which oxidation states would be present are important in analyzing such a repository and thus the present study was undertaken. A set of TGA (thermogravimetric analysis) tests were conducted on well-controlled samples of irradiated PWR fuel with time and temperature as the only variables. The tests were conducted between 140 and 225 0 C for a duration up to 2200 hours. The weight gain curves were analyzed in terms of diffusion through a layer of U 3 O 7 , diffusion into the grains to form a solid solution, a simplified empirical representation of a combination of grain boundary diffusion and bulk grain oxidation. Reaction rate constants were determined in each case, but analysis of these data could not establish a definitive mechanism. 21 refs., 10 figs., 3 tabs

  4. Ventilation planning for a prospective nuclear waste repository

    International Nuclear Information System (INIS)

    Wallace, K.G. Jr.

    1987-01-01

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

  5. 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

  6. A Transportation Risk Assessment Tool for Analyzing the Transport of Spent Nuclear Fuel and High-Level Radioactive Waste to the Proposed Yucca Mountain Repository

    International Nuclear Information System (INIS)

    Best, Ralph; Winnard, T.; Ross, S.; Best, R.

    2001-01-01

    The Yucca Mountain Transportation Database was developed as a data management tool for assembling and integrating data from multiple sources to compile the potential transportation impacts presented in the Draft Environmental Impact Statement for a Geologic Repository for the Disposal of Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain, Nye County, Nevada (DEIS). The database uses the results from existing models and codes such as RADTRAN, RISKIND, INTERLINE, and HIGHWAY to estimate transportation-related impacts of transporting spent nuclear fuel and high-level radioactive waste from commercial reactors and U. S. Department of Energy (DOE) facilities to Yucca Mountain. The source tables in the database are compendiums of information from many diverse sources including: radionuclide quantities for each waste type; route and route characteristics for rail, legal-weight truck, heavy haul. truck, and barge transport options; state-specific accident and fatality rates for routes selected for analysis; packaging and shipment data by waste type; unit risk factors; the complex behavior of the packaged waste forms in severe transport accidents; and the effects of exposure to radiation or the isotopic specific effects of radionclides should they be released in severe transportation accidents. The database works together with the codes RADTRAN (Neuhauser, et al, 1994) and RISKlND (Yuan, et al, 1995) to calculate incident-free dose and accident risk. For the incident-free transportation scenario, the database uses RADTRAN and RISKIND-generated data to calculate doses to offlink populations, onlink populations, people at stops, crews, inspectors, workers at intermodal transfer stations, guards at overnight stops, and escorts, as well as non-radioactive pollution health effects. For accident scenarios, the database uses RADTRAN-generated data to calculate dose risks based on ingestion, inhalation, resuspension, immersion (cloudshine), and groundshine as

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

    Science.gov (United States)

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

    2017-11-01

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

  8. 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

  9. Fuel and nuclear fuel cycle

    International Nuclear Information System (INIS)

    Prunier, C.

    1998-01-01

    The nuclear fuel is studied in detail, the best choice and why in relation with the type of reactor, the properties of the fuel cans, the choice of fuel materials. An important part is granted to the fuel assembly of PWR type reactor and the performances of nuclear fuels are tackled. The different subjects for research and development are discussed and this article ends with the particular situation of mixed oxide fuels ( materials, behavior, efficiency). (N.C.)

  10. Dose and dose commitment calculations from groundwaterborne radio-active elements released from a repository for spent nuclear fuel

    International Nuclear Information System (INIS)

    Bergstroem, U.

    1983-05-01

    The turnover of radioactive matter entering the biosphere with groundwater has been studied with regard to exposure and doses to critical groups and populations. Two main recipients, a well and a lake, have been considered for the inflow of groundwaterborne nuclides. Mathematical models of a set of coupled ecosystems on regional, intermediate and global levels have been used for calculations of doses. The intermediate system refers to the Baltic Sea. The mathematical treatment of the model is based upon compartment theory with first order kinetics and also includes products in decay chains. The time-dependent exposures have been studied for certain long-lived nuclides of radiological interest in waste from disposed fuel. Dose and dose commitment have been calculated for different episodes for inflow to the biosphere. (author)

  11. Alternatives for nuclear fuel disposal

    International Nuclear Information System (INIS)

    Ramirez S, J. R.; Badillo A, V.; Palacios H, J.; Celis del Angel, L.

    2010-10-01

    The spent fuel is one of the most important issues in the nuclear industry, currently spent fuel management is been cause of great amount of research, investments in the construction of repositories or constructing the necessary facilities to reprocess the fuel, and later to recycle the plutonium recovered in thermal reactors. What is the best solution? or, What is the best technology for a specific solution? Many countries have deferred the decision on selecting an option, while other works actively constructing repositories and others implementing the reprocessing facilities to recycle the plutonium obtained from nuclear spent fuel. In Mexico the nuclear power is limited to two reactors BWR type and medium size. So the nuclear spent fuel discharged has been accommodated at reactor's spent fuel pools. Originally these pools have enough capacity to accommodate spent fuel for the 40 years of designed plant operation. However, currently is under process an extended power up rate to 20% of their original power and also there are plans to extend operational life for 20 more years. Under these conditions there will not be enough room for spent fuel in the pools. So this work describes some different alternatives that have been studied in Mexico to define which will be the best alternative to follow. (Author)

  12. Nuclear waste repository in basalt: preconceptual design guidelines

    International Nuclear Information System (INIS)

    1979-06-01

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

  13. Nuclear waste repository in basalt: preconceptual design guidelines

    Energy Technology Data Exchange (ETDEWEB)

    1979-06-01

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

  14. Logistics characterization for regional spent fuel repositories concept

    International Nuclear Information System (INIS)

    Joy, D.S.; Hudson, B.J.; Anthony, M.W.

    1980-08-01

    This report summarizes a study of logistics considerations for a four-region repository system for spent fuel disposal. The logistics considerations include: (1) yearly receipt and emplacement; (2) inventory; (3) away-from-reactor (AFR) storage; (4) nuclear capacity growth effects; (5) entire lifetime of reactors served by repository operations; (6) proportions of pressurized-water-reactor (PWR)/boiling-water-reactor (BWR) fuel; (7) proportions of rail and truck shipments; (8) shipping cask fleet requirements; (9) number of annual shipments; (10) mode (rail/truck) and cost of shipment; and (11) initial year for shipment to maintain full core reserve. The nation was divided into Northeast, North Central, Southern, and Western regions for evaluation purposes. Repository logistics were analyzed in each region based on three different capacity projections. For the Southern region, results for seven salt dome sites are presented. The Western region results cover four potential sites. The North Central and Northeastern regions results are not presented on a site specific basis. Conclusions are drawn based on the results. The methodology assumptions and references used in the logistics analysis are described for the convenience of the reader

  15. Analysis of spent fuel performance in a geologic repository

    International Nuclear Information System (INIS)

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

    1986-04-01

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

  16. Monte-Carlo based comparison of the personal dose for emplacement scenarios of spent nuclear fuel casks in generic deep geological repositories

    Energy Technology Data Exchange (ETDEWEB)

    Suarez, Hector Sauri; Becker, Franz; Metz, Volker [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Pang, Bo [Karlsruhe Institute of Technology (KIT), Eggenstein-Leopoldshafen (Germany). Inst. for Nuclear Waste Disposal (INE); Shenzhen Univ. (China). College of Physics and Energy

    2017-06-15

    In the operational phase of a deep geological disposal facility for high-level nuclear waste, the radiation field in the vicinity of a waste cask is influenced by the backscattered radiation of the surrounding walls of the emplacement drift. For a comparison of disposal of spent nuclear fuel in various host rocks, it is of interest to investigate the influence of the surrounding materials on the radiation field and the personal radiation exposure. In this generic study individual dosimetry of personnel involved in emplacement of casks with spent nuclear fuel in drifts in rock salt and in a clay formation was modelled.

  17. The effect of fuel burnup and dispersed water intrusion on the criticality of spent high-level nuclear fuel in a geologic repository

    International Nuclear Information System (INIS)

    Culbreth, W.G.; Zielinski, P.R.

    1994-01-01

    Studies of the spent fuel waste package have been conducted through the use of a Monte-Carlo neutron simulation program to determine the ability of the fuel to sustain a chain reaction. These studies have included fuel burnup and the effect of water mists on criticality. Results were compared with previous studies. In many criticality studies of spent fuel waste packages, fresh fuel with an enrichment as high as 4.5% is used as the conservative (worst) case. The actual spent fuel has a certain amount of burnup that decreases the concentration of fissile uranium and increases the amount of radionuclides present. The LWR Radiological Data Base from OCRWM has been used to determine the relative radionuclide ratios and KENO 5.1 was used to calculate values of the effective multiplication factor, k eff . Spent fuel is not capable of sustaining a chain reaction unless a suitable moderator, such as water, is present. A completely flooded container has been treated as the worst case for criticality. Results of a previous report that demonstrated that k eff actually peaked at a water-to-mixture ratio of 13% were analyzed for validity. In the present study, these results did not occur in the SCP waste package container

  18. A Single Global Small-User Nuclear Repository

    International Nuclear Information System (INIS)

    Conca, J.L.; Wright, J.

    2009-01-01

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

  19. Nuclear fuel

    International Nuclear Information System (INIS)

    Quinauk, J.P.

    1990-01-01

    Since 1985, Fragema has been marketing and selling the Advanced Fuel Assemby AFA whose main features are its zircaloy grids and removable top and bottom nozzles. It is this product, which exists for several different fuel assembly arrays and heights, that will be employed in the reactors at Daya Bay. Fragema employs gadolinium as the consumable poison to enable highperformance fuel management. More recently, the company has supplied fuel assemblies of the mixed-oxide(MOX) and enriched reprocessed uranium type. The reliability level of the fuel sold by Fragema is one of the highest in the world, thanks in particular to the excellence of the quality assurance and quality control programs that have been implemented at all stages of its design and manufacture

  20. Milestones for Selection, Characterization, and Analysis of the Performance of a Repository for Spent Nuclear Fuel and High-Level Radioactive Waste at Yucca Mountain.

    Energy Technology Data Exchange (ETDEWEB)

    Rechard, Robert P. [Sandia National Lab. (SNL-NM), Albuquerque, NM (United States)

    2015-02-01

    This report presents a concise history in tabular form of events leading up to site identification in 1978, site selection in 1987, subsequent characterization, and ongoing analysis through 2009 of the performance of a repository for spent nuclear fuel and high - level radioactive waste at Yucca Mountain in southern Nevada. The tabulated events generally occurred in five periods: (1) commitment to mined geologic disposal and identification of sites; (2) site selection and analysis, based on regional geologic characterization through literature and analogous data; (3) feasibility analysis demonstrating calculation procedures and importance of system components, based on rough measures of performance using surface exploration, waste process knowledge, and general laboratory experiments; (4) suitability analysis demonstrating viability of disposal system, based on environment - specific laboratory experiments, in - situ experiments, and underground disposal system characterization; and (5) compliance analysis, based on completed site - specific characterization . The current sixth period beyond 2010 represents a new effort to set waste management policy in the United States. Because the relationship is important to understanding the evolution of the Yucca Mountain Project , the tabulation also shows the interaction between the policy realm and technical realm using four broad categories of events : (a) Regulatory requirements and related federal policy in laws and court decisions, (c) Presidential and agency directives, (c) technical milestones of implementing institutions, and (d) critiques of the Yucca Mountain Project and pertinent national and world events related to nuclear energy and radioactive waste. Preface The historical progression of technical milestones for the Yucca Mountain Project was originally developed for 10 journal articles in a special issue of Reliability Engineering System Safety on the performance assessment for the Yucca Mountain license

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

    International Nuclear Information System (INIS)

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

    2006-01-01

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

  2. 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

  3. Postclosure safety assessment of a used fuel repository in sedimentary rock

    International Nuclear Information System (INIS)

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

    2014-01-01

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

  4. Postclosure safety assessment of a used fuel repository in sedimentary rock

    Energy Technology Data Exchange (ETDEWEB)

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

    2014-07-01

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

  5. Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options

    International Nuclear Information System (INIS)

    Dixon, B.W.; Piet, S.J.

    2004-01-01

    The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the statutory limit of the first repository. There are several approaches to eliminate the need for another repository in this century. This paper presents a high-level analysis of these spent fuel management options in the context of a full range of possible nuclear energy futures. The analysis indicates the best option to implement varies depending on the nuclear energy future selected

  6. 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

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

    International Nuclear Information System (INIS)

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

    1979-11-01

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

  8. Commercial nuclear waste repository in basalt

    International Nuclear Information System (INIS)

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

    1980-06-01

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

  9. Construction of First Phase of Spent Fuel Repository in Finland: Lessons Learned and Success Factors

    International Nuclear Information System (INIS)

    Varjoranta, T.; Paltemaa, R.

    2015-01-01

    The Finnish nuclear legislation defines spent fuel as nuclear waste and requires that it has to be disposed of in the Finnish bedrock. Over 30 years of systematic R&D has been carried out to develop the repository concept, site selection, technologies, safety assessment and the regulatory approach. Activities are based on the Finnish Government’s long term strategies since 1983 and the public acceptance at local, Governmental and Parliament levels, approved and documented in the legal “Decision in Principle” (DiP) in 2000 to locate the repository at Olkiluoto. The DiP provided authorization to construct the first phase of the repository to the depth of the planned disposal. The construction of the 1 st phase of the repository started 2004 and has now reached the depth of 407 m. This paper identifies and discusses lessons learned and key success factors of the progress made. (author)

  10. Informing future societies about nuclear waste repositories

    International Nuclear Information System (INIS)

    Jensen, M.

    1994-01-01

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

  11. Tourism and visiting activities in Tierp. Threats and possibilities with a repository for spent nuclear fuel; Turism och besoeksnaering i Tierp. Hot och moejligheter med ett djupfoervar av anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    Bjoerne, S.; Sandberg, M. [EuroFutures AB, Stockholm (Sweden); Sahlberg, B. [EBS Invent AB (Sweden)

    1999-10-01

    Consequences for tourism and visiting at Tierp from siting a spent fuel repository in the community are studied. Tierp has little tourism as of today, and siting of the repository will probably lead to increased visiting of Tierp professionally and as a leisure activity.

  12. Nuclear fuel preheating system

    International Nuclear Information System (INIS)

    Andrea, C.

    1975-01-01

    A nuclear reactor new fuel handling system which conveys new fuel from a fuel preparation room into the reactor containment boundary is described. The handling system is provided with a fuel preheating station which is adaptd to heat the new fuel to reactor refueling temperatures in such a way that the fuel is heated from the top down so that fuel element cladding failure due to thermal expansions is avoided. (U.S.)

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

    International Nuclear Information System (INIS)

    ElBaradei, M.

    2003-01-01

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

  14. Minatom.ru - A nuclear information repository

    International Nuclear Information System (INIS)

    Fateyev, Eugene

    2002-01-01

    Developing of the nuclear during the previous 15 years have been mostly restrained by negative public attitude towards the industry. This is not only due to Chernobyl accident, but also due to lack of PR-programs for the nuclear. - Using the mentioned factors the opponents of Minatom ('green', some politicians, several tabloids, competitors in the energy market) conduct anti-nuclear activity. - Nevertheless, the nuclear grows in Russia now. 'The Chernobyl Syndrome' has been overcome. In many regions of the Russian Federation the public demands construction of N-plants. - A 10MW unit will be commissioned in Russia yearly in the coming decade. Up to the year 2020 production of the electricity at the Russian N-plants will grow each year which is twice more than expected growth of productivity at other types of electric power stations (hydro, coal, oil and gas). - Minatom's web-site is visited mostly by nuclear specialists and those who are interested in the nuclear: clerks from other departments, students and Minatom's antagonists. - What we are trying to do is to convert the web-site into a mass media edition of the Russian nuclear. 'Atomic News' agency has been created within the web-site editorial board. 1800 sources of information concerning the nuclear are quoted daily in the 'Digest of Russian and Foreign Press' on the web-site. Opinion of renown persons on different problems related with the nuclear are published on the web-site. Web-site editorial board also organizes interactive press conferences of the industry high officials. Electronic versions of different periodicals issued by Minatom are also placed on the site as well as the videos produced by 'TV-100' studio working within Atominform. - As an example of a successful Minatom and its web-site PR-campaign we may speak about the discussion that took place in the State Duma (Parliament) and was devoted to importing of foreign irradiated fuel. Many politicians used the concern of the broad public presented

  15. Applicability of risk-informed criticality methodology to spent fuel repositories

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  16. Opportunities for national repositories to resolve security challenges of past, present and future nuclear eras

    International Nuclear Information System (INIS)

    Sanders, T.L.

    2005-01-01

    With the global nuclear picture becoming even more complex, the role of repositories in accomplishing arms control, homeland security, and proliferation prevention goals has moved to front and center. Evolving repository infrastructures offer outstanding opportunities for illustrating advanced approaches for managing these risks. The traditional defense-in-depth concepts used to manage fuel cycle safety and protect nuclear materials in the U.S. and other countries could also be established as a framework for developing hardened, secure, and proliferation resistant material infrastructures including disposal systems. This analysis concept has been effective in establishing the safety basis for nuclear fuel cycles, reactors, and nuclear waste repositories. The concept results in the balanced use of multiple, diverse barriers to prevent the occurrence of undesired events such as radioactive releases from a safety perspective, or materials theft from a physical protection perspective. (author)

  17. Romanian nuclear fuel program

    International Nuclear Information System (INIS)

    Budan, O.

    1999-01-01

    The paper presents and comments the policy adopted in Romania for the production of CANDU-6 nuclear fuel before and after 1990. The CANDU-6 nuclear fuel manufacturing started in Romania in December 1983. Neither AECL nor any Canadian nuclear fuel manufacturer were involved in the Romanian industrial nuclear fuel production before 1990. After January 1990, the new created Romanian Electricity Authority (RENEL) assumed the responsibility for the Romanian Nuclear Power Program. It was RENEL's decision to stop, in June 1990, the nuclear fuel production at the Institute for Nuclear Power Reactors (IRNE) Pitesti. This decision was justified by the Canadian specialists team findings, revealed during a general, but well enough technically founded analysis performed at IRNE in the spring of 1990. All fuel manufactured before June 1990 was quarantined as it was considered of suspect quality. By that time more than 31,000 fuel bundles had already been manufactured. This fuel was stored for subsequent assessment. The paper explains the reasons which provoked this decision. The paper also presents the strategy adopted by RENEL after 1990 regarding the Romanian Nuclear Fuel Program. After a complex program done by Romanian and Canadian partners, in November 1994, AECL issued a temporary certification for the Romanian nuclear fuel plant. During the demonstration manufacturing run, as an essential milestone for the qualification of the Romanian fuel supplier for CANDU-6 reactors, 202 fuel bundles were produced. Of these fuel bundles, 66 were part of the Cernavoda NGS Unit 1 first fuel load (the balance was supplied by Zircatec Precision Industries Inc. ZPI). The industrial nuclear fuel fabrication re-started in Romania in January 1995 under AECL's periodical monitoring. In December 1995, AECL issued a permanent certificate, stating the Romanian nuclear fuel plant as a qualified and authorised CANDU-6 fuel supplier. The re-loading of the Cernavoda NGS Unit 1 started in the middle

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

    KAUST Repository

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

    2014-01-01

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

  19. 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

  20. Nuclear fuel lease accounting

    International Nuclear Information System (INIS)

    Danielson, A.H.

    1986-01-01

    The subject of nuclear fuel lease accounting is a controversial one that has received much attention over the years. This has occurred during a period when increasing numbers of utilities, seeking alternatives to traditional financing methods, have turned to leasing their nuclear fuel inventories. The purpose of this paper is to examine the current accounting treatment of nuclear fuel leases as prescribed by the Financial Accounting Standards Board (FASB) and the Federal Energy Regulatory Commission's (FERC's) Uniform System of Accounts. Cost accounting for leased nuclear fuel during the fuel cycle is also discussed

  1. Current Comparison of Advanced Nuclear Fuel Cycles

    International Nuclear Information System (INIS)

    Steven Piet; Trond Bjornard; Brent Dixon; Robert Hill; Gretchen Matthern; David Shropshire

    2007-01-01

    This paper compares potential nuclear fuel cycle strategies--once-through, recycling in thermal reactors, sustained recycle with a mix of thermal and fast reactors, and sustained recycle with fast reactors. Initiation of recycle starts the draw-down of weapons-usable material and starts accruing improvements for geologic repositories and energy sustainability. It reduces the motivation to search for potential second geologic repository sites. Recycle in thermal-spectrum nuclear reactors achieves several recycling objectives; fast nuclear reactors achieve all of them

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

    International Nuclear Information System (INIS)

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

    1996-01-01

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

  3. The Nuclear Fuel Cycle

    International Nuclear Information System (INIS)

    2011-08-01

    This brochure describes the nuclear fuel cycle, which is an industrial process involving various activities to produce electricity from uranium in nuclear power reactors. The cycle starts with the mining of uranium and ends with the disposal of nuclear waste. The raw material for today's nuclear fuel is uranium. It must be processed through a series of steps to produce an efficient fuel for generating electricity. Used fuel also needs to be taken care of for reuse and disposal. The nuclear fuel cycle includes the 'front end', i.e. preparation of the fuel, the 'service period' in which fuel is used during reactor operation to generate electricity, and the 'back end', i.e. the safe management of spent nuclear fuel including reprocessing and reuse and disposal. If spent fuel is not reprocessed, the fuel cycle is referred to as an 'open' or 'once-through' fuel cycle; if spent fuel is reprocessed, and partly reused, it is referred to as a 'closed' nuclear fuel cycle.

  4. 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%.

  5. 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%.

  6. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Nakai, Keiichi

    1983-01-01

    Purpose: To decrease the tensile stresses resulted in a fuel can as well as prevent decladding of fuel pellets into the bore holes by decreasing the inner pressure within the nuclear fuel element. Constitution: A fuel can is filled with hollow fuel pellets, inserted with a spring for retaining the hollow fuel pellets with an appropriate force and, thereafter, closely sealed at the both ends with end plugs. A cylindrical body is disposed into the bore holes of the hollow fuel pellets. Since initial sealing gases and/or gaseous nuclear fission products can thus be excluded from the bore holes where the temperature is at the highest level, the inner pressure of the nuclear fuel element can be reduced to decrease the tensile strength resulted to the fuel can. Furthermore, decladding of fuel pellets into the bore holes can be prevented. (Moriyama, K.)

  7. Nuclear fuel replacement device

    International Nuclear Information System (INIS)

    Ritz, W.C.; Robey, R.M.; Wett, J.F.

    1984-01-01

    A fuel handling arrangement for a liquid metal cooled nuclear reactor having a single rotating plug eccentric to the fuel core and a fuel handling machine radially movable along a slot in the plug with a transfer station disposed outside the fuel core but covered by the eccentric plug and within range of movement of said fuel handling machine to permit transfer of fuel assemblies between the core and the transfer station. (author)

  8. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hindle, E.D.

    1981-01-01

    An array of rods comprising zirconium alloy sheathed nuclear fuel pellets assembled to form a fuel element for a pressurised water reactor is claimed. The helium gas pressure within each rod differs substantially from that of its closest neighbours

  9. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hindle, E.D.

    1984-01-01

    The fuel elements for a pressurised water reactor comprise arrays of rods of zirconium alloy sheathed nuclear fuel pellets. The helium gas pressure within each rod differs substantially from that of its closest neighbours

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2000-12-01

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

  11. Nuclear fuel accounting

    International Nuclear Information System (INIS)

    Aisch, D.E.

    1977-01-01

    After a nuclear power plant has started commercial operation the actual nuclear fuel costs have to be demonstrated in the rate making procedure. For this purpose an accounting system has to be developed which comprises the following features: 1) All costs associated with nuclear fuel shall be correctly recorded; 2) it shall be sufficiently flexible to cover also deviations from proposed core loading patterns; 3) it shall be applicable to different fuel cycle schemes. (orig./RW) [de

  12. Ontario Hydro's plan for used nuclear fuel

    International Nuclear Information System (INIS)

    Stevens-Guille, P.D.; Howes, H.A.; Freire-Canosa, J.

    1992-01-01

    A comprehensive plan for the management of used nuclear fuel has been published by Ontario Hydro. In this paper current practices are discussed and actions leading to disposal in a repository are outlined. Extended storage options are discussed should disposal be delayed

  13. A GoldSim Model and a Sensitivity Study for Safety Assessment of a Repository for Disposal of Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Lee, Youn Myoung; Hwang, Yong Soo

    2008-11-01

    An assessment program for the evaluation of a high-level waste (HLW) repository has been developed by utilizing GoldSim, by which nuclide transports in the near- and far-field of a repository as well as a transport through a biosphere under various natural and manmade disruptive events affecting a nuclide release could be modeled and evaluated. To demonstrate its usability, three illustrative cases including the influence of a groundwater flow pattern through canisters associated with a flowing groundwater through fractures, and the possible disruptive events caused by an accidental human intrusion or an earthquake have been investigated and illustrated for a hypothetical Korean HLW repository

  14. Forecasts and restrictions on vibrations from rock excavation and transportation. Encapsulation Plant and Repository for spent nuclear fuel, Laxemar; Prognoser och restriktioner foer vibrationer fraan bergschaktning och transporter. Inkapslingsanlaeggning och slutfoervar foer anvaent kaernbraensle, Laxemar

    Energy Technology Data Exchange (ETDEWEB)

    Lind, Carl; Johansson, Sven-Erik (Nitro Consult AB (Sweden))

    2010-12-15

    This study describes the impact on the surroundings that may occur during rock excavation activities for the final repository for spent nuclear fuel in Laxemar and the encapsulation facility in Simpevarp. The study also includes vibrations created by heavy shipments related to activities at the final repository. The study will provide input to the environmental impact assessment and future design work. The survey area for buildings and facilities covered by the study extends approximately 1,000 metres from the proposed location of the final repository. For the encapsulation facility the survey area has been limited to residential buildings and summer houses within 1,000 metres of the proposed location. In addition, residential buildings along road 743 have been surveyed with regard to the impact of heavy shipments between Laxemar and Faarbo. The results of the surveys and information on planned rock excavation activities have been used to formulate preliminary restrictions and predictions of vibrations and air shock waves from blasting, as well as noise from rock drilling. Predictions have also been made of vibrations from heavy shipments, and a reference survey has been carried out in a residential building near road 743. The predictions of vibrations from blasting rounds reveal low or very low levels. No risk of damage to buildings or equipment is expected. Vibrations from blasting may, however, be perceptible within large parts of the study area, since the human perception threshold for vibration is very low. They will hardly be regarded as disturbing, however. When the accesses to the final repository have been built and rock excavation continues at repository level, the impact on the surroundings is expected to be minimal. The main reason for this is that the blasting will then occur at a depth of about 500 metres, at an ample distance to buildings at surface level. Predictions of air shock waves from blasting rounds indicate low levels. There is no risk of

  15. The nuclear fuel cycle

    International Nuclear Information System (INIS)

    1998-05-01

    After a short introduction about nuclear power in the world, fission physics and the French nuclear power plants, this brochure describes in a digest way the different steps of the nuclear fuel cycle: uranium prospecting, mining activity, processing of uranium ores and production of uranium concentrates (yellow cake), uranium chemistry (conversion of the yellow cake into uranium hexafluoride), fabrication of nuclear fuels, use of fuels, reprocessing of spent fuels (uranium, plutonium and fission products), recycling of energetic materials, and storage of radioactive wastes. (J.S.)

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

    International Nuclear Information System (INIS)

    Vira, Juhani; Snellman, Margit

    2014-01-01

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

  17. 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

  18. Nuclear fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding, and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

  19. Nuclear fuel element

    International Nuclear Information System (INIS)

    Thompson, J.R.; Rowland, T.C.

    1976-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed. A heat conducting, fission product retaining metal liner of a refractory metal is incorporated in the fuel element between the cladding and the nuclear fuel to inhibit mechanical interaction between the nuclear fuel and the cladding, to isolate fission products and nuclear fuel impurities from contacting the cladding and to improve the axial thermal peaking gradient along the length of the fuel rod. The metal liner can be in the form of a tube or hollow cylindrical column, a foil of single or multiple layers in the shape of a hollow cylindrical column, or a coating on the internal surface of the cladding. Preferred refractory metal materials are molybdenum, tungsten, rhenium, niobium and alloys of the foregoing metals

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

    International Nuclear Information System (INIS)

    Puhrer, A.; Bauer, C.

    2014-01-01

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

  1. 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.

  2. 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.

  3. Nuclear fuel production

    International Nuclear Information System (INIS)

    Randol, A.G.

    1985-01-01

    The production of new fuel for a power plant reactor and its disposition following discharge from the power plant is usually referred to as the ''nuclear fuel cycle.'' The processing of fuel is cyclic in nature since sometime during a power plant's operation old or ''depleted'' fuel must be removed and new fuel inserted. For light water reactors this step typically occurs once every 12-18 months. Since the time required for mining of the raw ore to recovery of reusable fuel materials from discharged materials can span up to 8 years, the management of fuel to assure continuous power plant operation requires simultaneous handling of various aspects of several fuel cycles, for example, material is being mined for fuel to be inserted in a power plant 2 years into the future at the same time fuel is being reprocessed from a discharge 5 years prior. Important aspects of each step in the fuel production process are discussed

  4. Nuclear fuel element

    International Nuclear Information System (INIS)

    Mogard, J.H.

    1977-01-01

    A nuclear fuel element is disclosed for use in power producing nuclear reactors, comprising a plurality of axially aligned ceramic cylindrical fuel bodies of the sintered type, and a cladding tube of metal or metal alloys, wherein said cladding tube on its cylindrical inner surface is provided with a plurality of slightly protruding spacing elements distributed over said inner surface

  5. Nuclear fuel cycle

    International Nuclear Information System (INIS)

    1993-01-01

    Status of different nuclear fuel cycle phases in 1992 is discussed including the following issues: uranium exploration, resources, supply and demand, production, market prices, conversion, enrichment; reactor fuel technology; spent fuel management, as well as trends of these phases development up to the year 2010. 10 refs, 11 figs, 15 tabs

  6. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Sasaki, Y.; Tashima, J.

    1975-01-01

    A description is given of nuclear reactor fuel assemblies arranged in the form of a lattice wherein there is attached to the interface of one of two adjacent fuel assemblies a plate spring having a concave portion curved toward said interface and to the interface of the other fuel assembly a plate spring having a convex portion curved away from said interface

  7. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Anthony, A.J.

    1980-01-01

    A bimetallic spacer means is cooperatively associated with a nuclear fuel assembly and operative to resist the occurrence of in-reactor bowing of the nuclear fuel assembly. The bimetallic spacer means in one embodiment of the invention includes a space grid formed, at least principally, of zircaloy to the external surface of which are attached a plurality of stainless steel strips. In another embodiment the strips are attached to fuel pins. In each of the embodiments, the stainless steel strips during power production expand outwardly to a greater extent than do the members to which the stainless steel strips are attached, thereby forming stiff springs which abut against like bimetallic spacer means with which the other nuclear fuel assemblies are provided in a given nuclear reactor core to thus prevent the occurrence of in-reactor bowing of the nuclear fuel assemblies. (author)

  8. Cost analysis of spent nuclear fuel management

    International Nuclear Information System (INIS)

    Robertson, D.L.M.; Ford, L.M.

    1993-01-01

    The Department of Energy Civilian Radioactive Waste Management System (CRWMS) is chartered to develop a waste management system for the safe disposal of spent nuclear fuel (SNF) from the 131 nuclear power reactors in the United States and a certain amount of high level waste (HLW) from reprocessing operations. The current schedule is to begin accepting SNF in 1998 for storage at a Monitored Retrievable Storage (MRS) facility. Subsequently, beginning in 2010, the system is scheduled to begin accepting SNF at a permanent geologic repository in 2010 and HLW in 2015. At this time, a MRS site has not been selected. Yucca Mountain, Nevada is currently being evaluated as the candidate site for the repository for permanent geologic disposal of SNF. All SNF, with the possible exception of the SNF from the western reactors, is currently planned to be shipped to or through the MRS site en route to the repository. The repository will operate in an acceptance and performance confirmation phase for a 50 year period beginning in 2010 with an additional nine year closure and five year decontamination and decommissioning period. The MRS has a statutory maximum capacity of 15,000 Metric Tons Uranium (MTU), with a further restriction that it may not store more than 10,000 MTU until the repository begins accepting waste. The repository is currently scheduled to store 63,000 MTU of SNF and an additional 7,000 MTU equivalent of HLW for a total capacity of 70,000 MTU. The amended act specified the MRS storage limits and identified Yucca Mountain as the only site to be characterized. Also, an Office of the Nuclear Waste Negotiator was established to secure a voluntary host site for the MRS. The MRS, the repository, and all waste containers/casks will go through a Nuclear Regulatory Commission licensing process much like the licensing process for a nuclear power plant. Environmental assessments and impact statements will be prepared for both the MRS and repository

  9. Nuclear fuel storage facility

    International Nuclear Information System (INIS)

    Matsumoto, Takashi; Isaka, Shinji.

    1987-01-01

    Purpose: To increase the spent fuel storage capacity and reduce the installation cost in a nuclear fuel storage facility. Constitution: Fuels handled in the nuclear fuel storage device of the present invention include the following four types: (1) fresh fuels, (2) 100 % reactor core charged fuels, (3) spent fuels just after taking out and (4) fuels after a certain period (for example one half-year) from taking out of the reactor. Reactivity is high for the fuels (1), and some of fuels (2), while low in the fuels (3) (4), Source intensity is strong for the fuels (3) and some of the fuels (2), while it is low for the fuels (1) and (4). Taking notice of the fact that the reactivity, radioactive source intensity and generated after heat are different in the respective fuels, the size of the pool and the storage capacity are increased by the divided storage control. While on the other hand, since the division is made in one identical pool, the control method becomes important, and the working range is restricted by means of a template, interlock, etc., the operation mode of the handling machine is divided into four, etc. for preventing errors. (Kamimura, M.)

  10. 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

  11. Tunnel Boring Machine for nuclear waste repository research project

    International Nuclear Information System (INIS)

    Janzon, H.A.

    1994-01-01

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

  12. Hydrologic effects of natural disruptive events on nuclear repositories

    International Nuclear Information System (INIS)

    Davis, S.N.

    1979-01-01

    This report describes some possible hydrogeologic effects of disruptive events which may affect repositories for nuclear waste. The report concentrates on the effects of natural events which are judged to be most probable

  13. Reduction of repository heat load using advanced fuel cycles

    International Nuclear Information System (INIS)

    Preston, Jeff; Miller, L.F.

    2008-01-01

    With the geologic repository at Yucca Mountain already nearing capacity full before opening, advanced fuel cycles that introduce reprocessing, fast reactors, and temporary storage sites have the potential to allow the repository to support the current reactor fleet and future expansion. An uncertainty analysis methodology that combines Monte Carlo distribution sampling, reactor physics data simulation, and neural network interpolation methods enable investigation into the factor reduction of heat capacity by using the hybrid fuel cycle. Using a Super PRISM fast reactor with a conversion ratio of 0.75, burn ups reach up to 200 MWd/t that decrease the plutonium inventory by about 5 metric tons every 12 years. Using the long burn up allows the footprint of 1 single core loading of FR fuel to have an integral decay heat of about 2.5x10 5 MW*yr over a 1500 year period that replaces the footprint of about 6 full core loadings of LWR fuel for the number of years required to fuel the FR, which have an integral decay heat of about.3 MW*yr for the same time integral. This results in an increase of a factor of 4 in repository support capacity from implementing a single fast reactor in an equilibrium cycle. (authors)

  14. Nuclear Fuels: Present and Future

    Directory of Open Access Journals (Sweden)

    Donald R. Olander

    2009-02-01

    Full Text Available The important new developments in nuclear fuels and their problems are reviewed and compared with the status of present light-water reactor fuels. The limitations of these fuels and the reactors they power are reviewed with respect to important recent concerns, namely provision of outlet coolant temperatures high enough for use in H2 production, destruction of plutonium to eliminate proliferation concerns, and burning of the minor actinides to reduce the waste repository heat load and long-term radiation hazard. In addition to current oxide-based fuel-rod designs, the hydride fuel with liquid metal thermal bonding of the fuel-cladding gap is covered. Finally, two of the most promising Generation IV reactor concepts, the Very High Temperature Reactor and the Sodium Fast Reactor, and the accompanying reprocessing technologies, aqueous-based UREX and pyrometallurgical, are summarized. In all of the topics covered, the thermodynamics involved in the material's behavior under irradiation and in the reprocessing schemes are emphasized.

  15. Long-term safety for the final repository for spent nuclear fuel at Forsmark. Main report of the SR-Site project

    Energy Technology Data Exchange (ETDEWEB)

    2011-03-15

    The central conclusion of the safety assessment SR-Site is that a KBS-3 repository that fulfils long-term safety requirements can be built at the Forsmark site. This conclusion is reached because the favourable properties of the Forsmark site ensure the required long-term durability of the barriers of the KBS-3 repository. In particular, the copper canisters with their cast iron inserts have been demonstrated to provide a sufficient resistance to the mechanical and chemical loads to which they may be subjected in the repository environment. The conclusion is underpinned by: - The reliance of the KBS-3 repository on i) a geological environment that exhibits long-term stability with respect to properties of importance for long-term safety, i.e. mechanical stability, low groundwater flow rates at repository depth and the absence of high concentrations of detrimental components in the groundwater, and ii) the choice of naturally occurring materials (copper and bentonite clay) for the engineered barriers that are sufficiently durable in the repository environment to provide the barrier longevity required for safety. - The understanding, through decades of research at SKB and in international collaboration, of the phenomena that affect long-term safety, resulting in a mature knowledge base for the safety assessment. - The understanding of the characteristics of the site through several years of surface-based investigations of the conditions at depth and of scientific interpretation of the data emerging from the investigations, resulting in a mature model of the site, adequate for use in the safety assessment. - The detailed specifications of the engineered parts of the repository and the demonstration of how components fulfilling the specifications are to be produced in a quality assured manner, thereby providing a quality assured initial state for the safety assessment. The detailed analyses demonstrate that canister failures in a one million year perspective are rare

  16. Long-term safety for the final repository for spent nuclear fuel at Forsmark. Main report of the SR-Site project

    International Nuclear Information System (INIS)

    2011-03-01

    The central conclusion of the safety assessment SR-Site is that a KBS-3 repository that fulfils long-term safety requirements can be built at the Forsmark site. This conclusion is reached because the favourable properties of the Forsmark site ensure the required long-term durability of the barriers of the KBS-3 repository. In particular, the copper canisters with their cast iron inserts have been demonstrated to provide a sufficient resistance to the mechanical and chemical loads to which they may be subjected in the repository environment. The conclusion is underpinned by: - The reliance of the KBS-3 repository on i) a geological environment that exhibits long-term stability with respect to properties of importance for long-term safety, i.e. mechanical stability, low groundwater flow rates at repository depth and the absence of high concentrations of detrimental components in the groundwater, and ii) the choice of naturally occurring materials (copper and bentonite clay) for the engineered barriers that are sufficiently durable in the repository environment to provide the barrier longevity required for safety. - The understanding, through decades of research at SKB and in international collaboration, of the phenomena that affect long-term safety, resulting in a mature knowledge base for the safety assessment. - The understanding of the characteristics of the site through several years of surface-based investigations of the conditions at depth and of scientific interpretation of the data emerging from the investigations, resulting in a mature model of the site, adequate for use in the safety assessment. - The detailed specifications of the engineered parts of the repository and the demonstration of how components fulfilling the specifications are to be produced in a quality assured manner, thereby providing a quality assured initial state for the safety assessment. The detailed analyses demonstrate that canister failures in a one million year perspective are rare

  17. Nuclear fuel activities in Belgium

    Energy Technology Data Exchange (ETDEWEB)

    Bairiot, H

    1997-12-01

    In his presentation on nuclear fuel activities in belgium the author considers the following directions of this work: fuel fabrication, NPP operation, fuel performance, research and development programmes.

  18. Boosting nuclear fuels

    International Nuclear Information System (INIS)

    Demarthon, F.; Donnars, O.; Dupuy-Maury, F.

    2002-01-01

    This dossier gives a broad overview of the present day status of the nuclear fuel cycle in France: 1 - the revival of nuclear power as a solution to the global warming and to the increase of worldwide energy needs; 2 - the security of uranium supplies thanks to the reuse of weapon grade highly enriched uranium; 3 - the fabrication of nuclear fuels from the mining extraction to the enrichment processes, the fabrication of fuel pellets and the assembly of fuel rods; 4 - the new composition of present day fuels (UO x and chromium-doped pellets); 5 - the consumption of plutonium stocks and the Corail and Apa fuel assemblies for the reduction of plutonium stocks and the preservation of uranium resources. (J.S.)

  19. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    Klepfer, H.H.

    1974-01-01

    A nuclear fuel element is described which comprises: 1) an elongated clad container, 2) a layer of high lubricity material being disposed in and adjacent to the clad container, 3) a low neutron capture cross section metal liner being disposed in the clad container and adjacent to the layer, 4) a central core of a body of nuclear fuel material disposed in and partially filling the container and forming an internal cavity in the container, 5) an enclosure integrally secured and sealed at each end of the container, and a nuclear fuel material retaining means positioned in the cavity. (author)

  20. 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

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

    International Nuclear Information System (INIS)

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

    2000-01-01

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

  2. Nuclear fuel element

    International Nuclear Information System (INIS)

    Yamamoto, Seigoro.

    1994-01-01

    Ultrafine particles of a thermal neutron absorber showing ultraplasticity is dispersed in oxide ceramic fuels by more than 1% to 10% or lower. The ultrafine particles of the thermal neutron absorber showing ultrafine plasticity is selected from any one of ZrGd, HfEu, HfY, HfGd, ZrEu, and ZrY. The thermal neutron absorber is converted into ultrafine particles and solid-solubilized in a nuclear fuel pellet, so that the dispersion thereof into nuclear fuels is made uniform and an absorbing performance of the thermal neutrons is also made uniform. Moreover, the characteristics thereof, for example, physical properties such as expansion coefficient and thermal conductivity of the nuclear fuels are also improved. The neutron absorber, such as ZrGd or the like, can provide plasticity of nuclear fuels, if it is mixed into the nuclear fuels for showing the plasticity. The nuclear fuel pellets are deformed like an hour glass as burning, but, since the end portion thereof is deformed plastically within a range of a repulsive force of the cladding tube, there is no worry of damaging a portion of the cladding tube. (N.H.)

  3. A TRANSPORTATION RISK ASSESSMENT TOOL FOR ANALYZING THE TRANSPORT OF SPENT NUCLEAR FUEL AND HIGH-LEVEL RADIOACTIVE WASTE TO THE PROPOSED YUCCA MOUNTAIN REPOSITORY

    International Nuclear Information System (INIS)

    2001-01-01

    The Yucca Mountain Draft Environmental Impact Statement (DEIS) analysis addressed the potential for transporting spent nuclear fuel and high-level radioactive waste from 77 origins for 34 types of spent fuel and high-level radioactive waste, 49,914 legal weight truck shipments, and 10,911 rail shipments. The analysis evaluated transportation over 59,250 unique shipment links for travel outside Nevada (shipment segments in urban, suburban or rural zones by state), and 22,611 links in Nevada. In addition, the analysis modeled the behavior of 41 isotopes, 1091 source terms, and used 8850 food transfer factors (distinct factors by isotope for each state). The analysis also used mode-specific accident rates for legal weight truck, rail, and heavy haul truck by state, and barge by waterway. This complex mix of data and information required an innovative approach to assess the transportation impacts. The approach employed a Microsoft(reg s ign) Access database tool that incorporated data from many sources, including unit risk factors calculated using the RADTRAN IV transportation risk assessment computer program. Using Microsoft(reg s ign) Access, the analysts organized data (such as state-specific accident and fatality rates) into tables and developed queries to obtain the overall transportation impacts. Queries are instructions to the database describing how to use data contained in the database tables. While a query might be applied to thousands of table entries, there is only one sequence of queries that is used to calculate a particular transportation impact. For example, the incident-free dose to off-link populations in a state is calculated by a query that uses route segment lengths for each route in a state that could be used by shipments, populations for each segment, number of shipments on each segment, and an incident-free unit risk factor calculated using RADTRAN IV. In addition to providing a method for using large volumes of data in the calculations, the

  4. 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

  5. Transportation of nuclear fuel

    International Nuclear Information System (INIS)

    Prowse, D.R.

    1979-01-01

    Shipment of used fuel from nuclear reactors to a central fuel management facility is discussed with particular emphasis on the assessment of the risk to the public due to these shipments. The methods of transporting used fuel in large shipping containers is reviewed. In terms of an accident scenario, it is demonstrated that the primary risk of transport of used fuel is due to injury and death in common road accidents. The radiological nature of the used fuel cargo is, for all practical purposes, an insignificant factor in the total risk to the public. (author)

  6. Nuclear fuel banks

    International Nuclear Information System (INIS)

    Anon.

    2010-01-01

    In december 2010 IAEA gave its agreement for the creation of a nuclear fuel bank. This bank will allow IAEA to help member countries that renounce to their own uranium enrichment capacities. This bank located on one or several member countries will belong to IAEA and will be managed by IAEA and its reserve of low enriched uranium will be sufficient to fabricate the fuel for the first load of a 1000 MW PWR. Fund raising has been successful and the running of the bank will have no financial impact on the regular budget of the IAEA. Russia has announced the creation of the first nuclear fuel bank. This bank will be located on the Angarsk site (Siberia) and will be managed by IAEA and will own 120 tonnes of low-enriched uranium fuel (between 2 and 4.95%), this kind of fuel is used in most Russian nuclear power plants. (A.C.)

  7. The nuclear fuel cycle

    International Nuclear Information System (INIS)

    Jones, P.M.S.

    1987-01-01

    This chapter explains the distinction between fissile and fertile materials, examines briefly the processes involved in fuel manufacture and management, describes the alternative nuclear fuel cycles and considers their advantages and disadvantages. Fuel management is usually divided into three stages; the front end stage of production and fabrication, the back end stage which deals with the fuel after it is removed from the reactor (including reprocessing and waste treatment) and the stage in between when the fuel is actually in the reactor. These stages are illustrated and explained in detail. The plutonium fuel cycle and thorium-uranium-233 fuel cycle are explained. The differences between fuels for thermal reactors and fast reactors are explained. (U.K.)

  8. Nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Merrett, G.J.; Gillespie, P.A.

    1983-07-01

    This report discusses events and processes that could adversely affect the long-term stability of a nuclear fuel waste disposal vault or the regions of the geosphere and the biosphere to which radionuclides might migrate from such a vault

  9. The nuclear fuel cycle

    International Nuclear Information System (INIS)

    Patarin, L.

    2002-01-01

    This book treats of the different aspects of the industrial operations linked with the nuclear fuel, before and after its use in nuclear reactors. The basis science of this nuclear fuel cycle is chemistry. Thus a recall of the elementary notions of chemistry is given in order to understand the phenomena involved in the ore processing, in the isotope enrichment, in the fabrication of fuel pellets and rods (front-end of the cycle), in the extraction of recyclable materials (residual uranium and plutonium), and in the processing and conditioning of wastes (back-end of the fuel cycle). Nuclear reactors produce about 80% of the French electric power and the Cogema group makes 40% of its turnover at the export. Thus this book contains also some economic and geopolitical data in order to clearly position the stakes. The last part, devoted to the management of wastes, presents the solutions already operational and also the research studies in progress. (J.S.)

  10. Nuclear fuel reprocessing

    International Nuclear Information System (INIS)

    White, D.

    1981-01-01

    A simple friction device for cutting nuclear fuel wrappers comprising a thin metal disc clamped between two large diameter clamping plates. A stream of gas ejected from a nozzle is used as coolant. The device may be maintained remotely. (author)

  11. Nuclide migration from a bedrock repository for spent fuel

    International Nuclear Information System (INIS)

    Grundfelt, B.

    1978-08-01

    A study of the migration of radionuclides from a repository for spent, unprocessed fuel is presented. The study makes use of a unidimensional dispersion model developed at BNWL. The results show that a number of nuclides decay significantly during the migration. The doses to future man was calculated in a separate study performed at Studsvik. The dose calculations are based on the activity in-flows, presented in this report, and show that the predominant dose contribution comes from the nuclide radium-226. This nuclide is formed mainly by the decay of uranium-238 which means that the main part of the dose would arise even from a repository for non-irradiated fuel

  12. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Hayashi, Hiroshi; Watari, Yoshio; Hizahara, Hiroshi; Masuoka, Ryuzo.

    1970-01-01

    When exchanging nuclear fuel assemblies during the operation of a nuclear reactor, melting of fuel bodies, and severence of tubular claddings is halted at the time of insertion by furnishing a neutron absorbing material such as B 10 , Cd, Gd or the like at the forward end of the fuel assembly to thereby lower the power peak at the forward ends of the fuel elements to within tolerable levels and thus prevent both fuel liquification and excessive expansion. The neutron absorbing material may be attached in the form of a plate to the fuel assembly forward tie plate, or may be inserted as a pellet into the front end of the tubular cladding. (Owens, K.J.)

  13. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Ainsworth, K.F.

    1979-01-01

    A nuclear fuel element is described having a cluster of nuclear fuel pins supported in parallel, spaced apart relationship by transverse cellular braces within coaxial, inner and outer sleeves, the inner sleeve being in at least two separate axial lengths, each of the transverse braces having a peripheral portion which is clamped peripherally between the ends of the axial lengths of the inner sleeve. (author)

  14. 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)

  15. Dynamic Systems Analysis Report for Nuclear Fuel Recycle

    Energy Technology Data Exchange (ETDEWEB)

    Brent Dixon; Sonny Kim; David Shropshire; Steven Piet; Gretchen Matthern; Bill Halsey

    2008-12-01

    This report examines the time-dependent dynamics of transitioning from the current United States (U.S.) nuclear fuel cycle where used nuclear fuel is disposed in a repository to a closed fuel cycle where the used fuel is recycled and only fission products and waste are disposed. The report is intended to help inform policy developers, decision makers, and program managers of system-level options and constraints as they guide the formulation and implementation of advanced fuel cycle development and demonstration efforts and move toward deployment of nuclear fuel recycling infrastructure.

  16. Monitoring of spent nuclear fuel with antineutrino detectors

    Science.gov (United States)

    Brdar, Vedran

    2017-09-01

    We put forward the possibility of employing antineutrino detectors in order to control the amounts of spent nuclear fuel in repositories or, alternatively, to precisely localize the underground sources of nuclear material. For instance, we discuss the applicability in determining a possible leakage of stored nuclear material which would aid in preventing environmental problems. The long-term storage facilities are also addressed.

  17. Nuclear fuel manufacture

    International Nuclear Information System (INIS)

    Costello, J.M.

    1980-09-01

    The technologies used to manufacture nuclear fuel from uranium ore are outlined, with particular reference to the light water reactor fuel cycle. Capital and operating cost estimates for the processing stages are given, and the relevance to a developing uranium industry in Australia is discussed

  18. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Butterfield, C.E.; Waite, E.

    1982-01-01

    A nuclear reactor fuel element comprising a column of vibration compacted fuel which is retained in consolidated condition by a thimble shaped plug. The plug is wedged into gripping engagement with the wall of the sheath by a wedge. The wedge material has a lower coefficient of expansion than the sheath material so that at reactor operating temperature the retainer can relax sufficient to accommodate thermal expansion of the column of fuel. (author)

  19. 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

  20. Nuclear fuel pellet loading apparatus

    International Nuclear Information System (INIS)

    Gerkey, K.S.

    1979-01-01

    An automatic apparatus for loading a predetermined amount of nuclear fuel pellets into a nuclear fuel element to be used in a nuclear reactor is described. The apparatus consists of a vibratory bed capable of supporting corrugated trays containing rows of nuclear fuel pellets and arranged in alignment with the open ends of several nuclear fuel elements. A sweep mechanism is arranged above the trays and serves to sweep the rows of fuel pellets onto the vibratory bed and into the fuel element. A length detecting system, in conjunction with a pellet stopping mechanism, is also provided to assure that a predetermined amount of nuclear fuel pellets are loaded into each fuel element

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

    International Nuclear Information System (INIS)

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

    1992-09-01

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

  2. Transport of encapsulated nuclear fuels

    International Nuclear Information System (INIS)

    Broman, Ulrika; Dybeck, Peter; Ekendahl, Ann-Mari

    2005-12-01

    The transport system for encapsulated fuel is described, including a preliminary drawing of a transport container. In the report, the encapsulation plant is assumed to be located to Oskarshamn, and the repository to Oskarshamn or Forsmark

  3. Nuclear Fuel Cycle Objectives

    International Nuclear Information System (INIS)

    2013-01-01

    . The four Objectives publications include Nuclear General Objectives, Nuclear Power Objectives, Nuclear Fuel Cycle Objectives, and Radioactive Waste management and Decommissioning Objectives. This publication sets out the objectives that need to be achieved in the area of the nuclear fuel cycle to ensure that the Nuclear Energy Basic Principles are satisfied. Within each of these four Objectives publications, the individual topics that make up each area are addressed. The five topics included in this publication are: resources; fuel engineering and performance; spent fuel management and reprocessing; fuel cycles; and the research reactor nuclear fuel cycle

  4. Basis for applying for exemption according to species protection regulation. Final repository for spent nuclear fuel at Forsmark; Underlag till ansoekan om dispens enligt artskyddsfoerordningen. Slutfoervar foer anvaent kaernbraensle i Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    SKB will submit applications for permits and admissibility under the Environmental Act and under the Nuclear Activities Act to construct and operate a disposal facility for spent nuclear fuel at Forsmark. In the final repository the spent nuclear fuel from Swedish nuclear power plants is placed in order to protect human health and the environment against harmful effects of ionizing radiation. Construction and operation of the disposal facility in Forsmark will make an impact, give effects and consequences for the natural environment. Utilization of land for the construction of the facility and the impact on ground water as a result of groundwater drainage is expected to have negative consequences for the species included in species protection regulation. Thus, the planned activity require exemption from species protection regulation (SFS 2007:845). The purpose of this document is to provide a basis for an application for exemption under 14 paragraph species protection regulation from the prohibitions of 4, 6, 7 and 8 paragraph species protection regulation. A basis for the exemption application is that the proposed activity is considered to have an 'overriding public interest' prescribed in 14 paragraph species protection regulation. The document reports the impact, effects and consequences of the planned activities on species covered in the species protection regulation. The impact on protected species can be divided into two categories: - Direct effects on protected species and their habitats by utilization of the land. - Indirect effects on protected species and their habitats in the drainage of groundwater and the effect on groundwater levels. The document also includes a description of planned actions to prevent, restrict and compensate for the effects and consequences that the activity may cause. By applying for an exemption under 14 paragraph species protection regulation in a separate order from the application for permit according to chapters 9

  5. Basis for applying for exemption according to species protection regulation. Final repository for spent nuclear fuel at Forsmark; Underlag till ansoekan om dispens enligt artskyddsfoerordningen. Slutfoervar foer anvaent kaernbraensle i Forsmark

    Energy Technology Data Exchange (ETDEWEB)

    2011-02-15

    SKB will submit applications for permits and admissibility under the Environmental Act and under the Nuclear Activities Act to construct and operate a disposal facility for spent nuclear fuel at Forsmark. In the final repository the spent nuclear fuel from Swedish nuclear power plants is placed in order to protect human health and the environment against harmful effects of ionizing radiation. Construction and operation of the disposal facility in Forsmark will make an impact, give effects and consequences for the natural environment. Utilization of land for the construction of the facility and the impact on ground water as a result of groundwater drainage is expected to have negative consequences for the species included in species protection regulation. Thus, the planned activity require exemption from species protection regulation (SFS 2007:845). The purpose of this document is to provide a basis for an application for exemption under 14 paragraph species protection regulation from the prohibitions of 4, 6, 7 and 8 paragraph species protection regulation. A basis for the exemption application is that the proposed activity is considered to have an 'overriding public interest' prescribed in 14 paragraph species protection regulation. The document reports the impact, effects and consequences of the planned activities on species covered in the species protection regulation. The impact on protected species can be divided into two categories: - Direct effects on protected species and their habitats by utilization of the land. - Indirect effects on protected species and their habitats in the drainage of groundwater and the effect on groundwater levels. The document also includes a description of planned actions to prevent, restrict and compensate for the effects and consequences that the activity may cause. By applying for an exemption under 14 paragraph species protection regulation in a separate order from the application for permit according to chapters 9 and 11

  6. Draft environmental assessment: reference repository location, Hanford Site, Washington. Nuclear Waste Policy Act (Section 112)

    International Nuclear Information System (INIS)

    1984-12-01

    In February 1983, the US Department of Energy (DOE) identified a reference repository location at the Hanford Site in Washington as one of nine potentially acceptable sites for a mined geologic repository for spent nuclear fuel and high-level radioactive waste. To determine their suitability, the reference repository location at the Hanford Site and the eight other potentially acceptable sites have been evaluated in accordance with the DOE's General Guidelines for the Recommendation of Sites for Nuclear Waste Repositories. These evaluations are reported in this draft environmental assessment (EA), which is being issued for public review and comment. The DOE findings and determinations that are based on these evaluations are preliminary and subject to public review and comment. A final EA will be prepared after considering the comments received on the draft EA. The reference repository location at Hanford is located in the Columbia Plateau, one of five distinct geohydrologic settings that are being considered for the first repository. On the basis of the evaluations reported in this draft EA, the DOE has found that the reference repository location at Hanford is not disqualified under the guidelines. The DOE has also found that it is suitable for site characterization because the evidence does not support a conclusion that the site will not be able to meet each of the qualifying conditions specified in the guidelines. On the basis of these findings, the DOE is proposing to nominate the reference repository location at Hanford as one of five sites suitable for characterization. Furthermore, having performed a comparative evaluation of the five sites proposed for nomination, the DOE has determined that the reference repository location at Hanford is one of three sites preferred for site characterization

  7. Nuclear fuel in a reactor accident.

    Science.gov (United States)

    Burns, Peter C; Ewing, Rodney C; Navrotsky, Alexandra

    2012-03-09

    Nuclear accidents that lead to melting of a reactor core create heterogeneous materials containing hundreds of radionuclides, many with short half-lives. The long-lived fission products and transuranium elements within damaged fuel remain a concern for millennia. Currently, accurate fundamental models for the prediction of release rates of radionuclides from fuel, especially in contact with water, after an accident remain limited. Relatively little is known about fuel corrosion and radionuclide release under the extreme chemical, radiation, and thermal conditions during and subsequent to a nuclear accident. We review the current understanding of nuclear fuel interactions with the environment, including studies over the relatively narrow range of geochemical, hydrological, and radiation environments relevant to geological repository performance, and discuss priorities for research needed to develop future predictive models.

  8. Nuclear power and the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Hardy, C.J.; Silver, J.M.

    1985-09-01

    The report provides data and assessments of the status and prospects of nuclear power and the nuclear fuel cycle. The report discusses the economic competitiveness of nuclear electricity generation, the extent of world uranium resources, production and requirements, uranium conversion and enrichment, fuel fabrication, spent fuel treatment and radioactive waste management. A review is given of the status of nuclear fusion research

  9. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    1974-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed and has a metal liner disposed between the cladding and the nuclear fuel material and a high lubricity material in the form of a coating disposed between the liner and the cladding. The liner preferably has a thickness greater than the longest fission product recoil distance and is composed of a low neutron capture cross-section material. The liner is preferably composed of zirconium, an alloy of zirconium, niobium or an alloy of niobium. The liner serves as a preferential reaction site for volatile impurities and fission products and protects the cladding from contact and reaction with such impurities and fission products. The high lubricity material acts as an interface between the liner and the cladding and reduces localized stresses on the cladding due to fuel expansion and cracking of the fuel

  10. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Wakamatsu, Mitsuo.

    1974-01-01

    Object: To improve a circulating flow passage of coolant so as to be able to accurately detect the temperature of coolant, rare gases contained, and the like. Structure: A fuel assembly comprising a flow regulating lattice provided with a plurality of communication holes in an axial direction, said lattice being positioned at the upper end of an outer tube in which nuclear fuel elements are received, and a neutron shielding body having a plurality of spiral coolant flow passages disposed between the lattice and the nuclear fuel elements, whereby a coolant comprised of liquid sodium or the like, which moves up passing through the coolant flow passages and the flow regulating passage, is regulated and passed through a detector mounted at the upper part of the flow regulating lattice to detect coolant temperature, flow rate, and rare gases or the like as the origin of nuclear fission contained in the coolant due to breakage of fuel elements. (Kamimura, M.)

  11. Nuclear fuel quality assurance

    International Nuclear Information System (INIS)

    1976-01-01

    Full text: Quality assurance is used extensively in the design, construction and operation of nuclear power plants. This methodology is applied to all activities affecting the quality of a nuclear power plant in order to obtain confidence that an item or a facility will perform satisfactorily in service. Although the achievement of quality is the responsibility of all parties participating in a nuclear power project, establishment and implementation of the quality assurance programme for the whole plant is a main responsibility of the plant owner. For the plant owner, the main concern is to achieve control over the quality of purchased products or services through contractual arrangements with the vendors. In the case of purchase of nuclear fuel, the application of quality assurance might be faced with several difficulties because of the lack of standardization in nuclear fuel and the proprietary information of the fuel manufacturers on fuel design specifications and fuel manufacturing procedures. The problems of quality assurance for purchase of nuclear fuel were discussed in detail during the seminar. Due to the lack of generally acceptable standards, the successful application of the quality assurance concept to the procurement of fuel depends on how much information can be provided by the fuel manufacturer to the utility which is purchasing fuel, and in what form and how early this information can be provided. The extent of information transfer is basically set out in the individual vendor-utility contracts, with some indirect influence from the requirements of regulatory bodies. Any conflict that exists appears to come from utilities which desire more extensive control over the product they are buying. There is a reluctance on the part of vendors to permit close insight of the purchasers into their design and manufacturing procedures, but there nevertheless seems to be an increasing trend towards release of more information to the purchasers. It appears that

  12. Plan for safety case of spent fuel repository at Olkiluoto

    International Nuclear Information System (INIS)

    Vieno, T.; Ikonen, A.T.K.

    2005-02-01

    Posiva aims to present the Safety Case supporting the construction license application of the spent fuel repository at Olkiluoto by 2012. An outline and preliminary assessments will be presented in 2009. Interim reporting and an update of the Safety Case plan will be presented in 2006, as required by the authorities. The KBS-3 disposal concept aims at long-term isolation and containment of spent fuel assemblies in durable copper-iron canisters emplaced in a repository to be constructed at a depth between 400 and 600 metres in crystalline bedrock. By 2012, studies on the KBS-3 disposal concept and site investigations at Olkiluoto will have been continued over about thirty years. The construction of an underground rock characterisation facility (called ONKALO) was started in June 2004. The investigations are carried out in close cooperation with the Swedish SKB developing and assessing the same disposal concept at candidate sites, resembling Olkiluoto, at the other side of the Baltic Sea. A safety case is the synthesis of evidence, analyses and arguments that quantify and substantiate the safety, and the level of expert confidence in the safety, of a planned repository. Posiva's Safety Case will be organised in a portfolio including ten main reports, which will be periodically updated according the overall schedule presented in the plan. The Site report describing the present state and past evolution of the Olkiluoto site, as well as the disturbances caused by the construction of ONKALO and the first stage of the repository, forms the geoscientific basis of the Safety Case. The engineering basis is provided by the reports on the Characteristics of spent fuel, Canister design, and Repository design. The Process report containing descriptions and analyses of features, events and processes potentially affecting the disposal system, and the report on the Evolution of site and repository form the scientific basis of the Safety Case. The latter report will describe and

  13. Technical note 1. Review of the Geomicrobiological Aspects of SKB's Licence Application for a Spent Nuclear Fuel Repository in Forsmark, Sweden

    International Nuclear Information System (INIS)

    Parkes, R. John

    2011-10-01

    The report reviews whether the research work by SKB has been adequately comprehensive to describe the influence of microbial activity for sulphide production at repository depth. The report also documents any uncertainties with regard to predictions of rates and consequences of microbial sulphide production. SKB's assessment relies almost entirely on the results of the research that they commissioned from the Univ. of Goeteborg (Pedersen, 2010, Masurat et al., 2010a, b). This is not an unreasonable position, as there is no directly comparable research available. However, there is considerable literature demonstrating continued activity of sulphate-reducing bacteria over geological time scales and enhanced activity of sulphate-reducing bacteria in interaction with metals and corrosion, that should also be taken into consideration when assessing potential microbially influenced corrosion (Beech and Sunner, 2007) of the copper canister

  14. Repository for spent nuclear fuel. Preliminary construction description - layout D Oskarshamn the Simpevarp area; Slutfoervar foer anvaent kaernbraensle. Preliminaer anlaeggningsbeskrivning - layout D. Oskarshamn, delomraade Simpevarp

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2006-02-15

    This report presents the preliminary design of a repository located in the Simpevarp area. The description has been disposed so as to deal primarily with the site dependent layouts for the above- and underground constructions. The report is disposed as follows: c1 gives the background and some basic information. Chapter 2 presents the demands and necessary conditions that take precedence when adapting the plant to the local conditions, construction, operation and closure. Chapter 3 is a general description of the area, its infrastructure and the specific sites that have been studied. Chapter 4-5 describe the design of the plant for the two chosen sites. Chapter 6 gives a review of data for the plant, and Chapter 7 'References' is the last part of the main document. The appendices A-I give brief information on the general, non-site specific, parts of the plant, e.g. buildings, life cycle, system, operation and organization.

  15. Reprocessing of nuclear fuels

    International Nuclear Information System (INIS)

    Hatfield, G.W.

    1960-11-01

    One of the persistent ideas concerning nuclear power is that the fuel costs are negligible. This, of course, is incorrect and, in fact, one of the major problems in the development of economic nuclear power is to get the cost of the fuel cycles down to an acceptable level. The irradiated fuel removed from the nuclear power reactors must be returned as fresh fuel into the system. Aside from the problems of handling and shipping involved in the reprocessing cycles, the two major steps are the chemical separation and the refabrication. The chemical separation covers the processing of the spent fuel to separate and recover the unburned fuel as well as the new fuel produced in the reactor. This includes the decontamination of these materials from other radioactive fission products formed in the reactor. Refabrication involves the working and sheathing of recycled fuel into the shapes and forms required by reactor design and the economics of the fabrication problem determines to a large extent the quality of the material required from the chemical treatment. At present there appear to be enough separating facilities in the United States and the United Kingdom to handle the recycling of fuel from power reactors for the next few years. However, we understand the costs of recycling fuel in these facilities will be high or low depend ing on whether or not the capital costs of the plant are included in the processing cost. Also, the present plants may not be well adapted to carry out the chemical processing of the very wide variety of power reactor fuel elements which are being considered and will continue to be considered over the years to come. (author)

  16. Spent fuel stability under repository conditions - final report of the european project

    International Nuclear Information System (INIS)

    Poinssot, Ch.; Ferry, C.; Kelm, M.; Cavedon, J.M.; Corbel, C.; Jegou, Ch.; Lovera, P.; Miserque, F.; Poulesquen, A.; Grambow, B.; Andriambololona, Z.; Martinez-Esparza, A.; Kelm, M.; Loida, A.; Rondinella, V.; Wegen, D.; Spahiu, K.; Johnson, L.; Cachoir, Ch.; Lemmens, K.; Quinones, J.; Bruno, J.; Christensen, H.; Grambow, B.; Pablo, J. de

    2005-01-01

    This report is the final report of the European Project 'Spent Fuel Stability under Repository Conditions' (FIKW-CT-2001-00192 SFS) funded by the European Commission from Nov.2000 to Oct.2004. Gathering the work performed by 13 partners from 6 countries, it aims to specifically focus on the spent nuclear fuel long term alteration in deep repository and the subsequent radionuclides release rate as a function of time. This report synthesised the wide experimental work performed within this project and enlightens the major outcomes, which can be summarised as follow: - A new model for defining the Instant Release Fraction was developed in order to consider the potential fuel evolution before the water penetrates the canister. Quantitative assessment has been produced and shows a significant contribution to the long term dose; - Based on new experimental data, kinetic radiolytic scheme have been upgraded and are used to determine the amount of oxidants produced at the fuel/water interface; - The existence of a dose threshold below which the water radiolysis does not influence the fuel alteration has been demonstrated and occurs between 3.5 and 33 MBq.g UO21. Above the threshold, the fuel alteration rates is directly related to the dose rate. - Hydrogen was experimentally demonstrated to be an efficient oxidants scavenger preventing therefore the fuel oxidation. Molecular mechanism still need to be understood. - Finally, a new Matrix Alteration Model integrating most of the SFS results (apart of the hydrogen effect) has been developed and used to assess the fuel long tern stability in representative conditions of deep repository in salt, clay-rock and granite. The breadth of the results and the significance of the conclusions testify of the success of the collaboration within the project. (authors)

  17. Evaluation of alternative spent fuel waste package concepts for a repository in Basalt

    International Nuclear Information System (INIS)

    Hall, G.V.B.; Nair, B.R.

    1986-01-01

    The United States government has established a program for the disposal of spent nuclear fuel and high-level radioactive waste. The Nuclear Waste Policy Act (NWPA) of 1982 requires the first nuclear waste repository to begin receiving high-level radioactive waste in 1998. One of the potentially acceptable sites currently being evaluated is the Hanford Site in the Pasco Basin in the state of Washington where the host rock is basalt. Under the direction of the United States Department of Energy (DOE), Rockwell International's Rockwell Hanford Operations (RHO) has initiated the Basalt Waste Isolation Project (BWIP). The BWIP must design waste packages for emplacement in the repository. As part of the BWIP waste package development program, several alternative designs were considered for the disposal of spent nuclear fuel. This paper describes the concepts that were evaluated, the criteria that was developed for judging their relative merits, and the methodology that was employed. The results of the evaluation show that a Pipe-In-Tunnel design, which uses a long carbon steel pipe for the containment barrier for multiple packages of consolidated spent fuel, has the highest rating. Other designs which had high ratings are also discussed

  18. Nuclear fuel assemblies

    International Nuclear Information System (INIS)

    Butterfield, R.S.; Garner, D.L.M.

    1977-01-01

    Reference is made to nuclear fuel assemblies designed for cooling on the 'tube-in-shell' principle in which the fuel is contained by a shell and is cooled by coolant passed through tubes extending through the shell. It has been proposed to employ coated particle fuel as a porous bed on the tube side and the bleed coolant from the tubes into direct contact with the fuel particles. In this way heat is extracted both by direct contact with the fuel and by heat transfer through the coolant tube walls. The system described aims to provide an improved structure of tube and shell for a fuel assembly of this kind and is particularly suitable for use in a gas cooled fast reactor, being able to withstand the neutron flux and high temperature conditions in these reactors. Constructional details are given. (U.K.)

  19. Nuclear fuel element

    International Nuclear Information System (INIS)

    Hirayama, Satoshi; Kawada, Toshiyuki; Matsuzaki, Masayoshi.

    1980-01-01

    Purpose: To provide a fuel element for reducing the mechanical interactions between a fuel-cladding tube and the fuel element and for alleviating the limits of the operating conditions of a reactor. Constitution: A fuel element having mainly uranium dioxide consists of a cylindrical outer pellet and cylindrical inner pellet inserted into the outer pellet. The outer pellet contains two or more additives selected from aluminium oxide, beryllium oxide, magnesium oxide, silicon oxide, sodium oxide, phosphorus oxide, calcium oxide and iron oxide, and the inner pellet contains nuclear fuel substance solely or one additive selected from calcium oxide, silicon oxide, aluminium oxide, magnesium oxide, zirconium oxide and iron oxide. The outer pellet of the fuel thus constituted is reduced in mechanical strength and also in the mechanical interactions with the cladding tube, and the plastic fluidity of the entire pellet is prevented by the inner pellet increased in the mechanical strength. (Kamimura, M.)

  20. Nuclear fuel deformation phenomena

    International Nuclear Information System (INIS)

    Van Brutzel, L.; Dingreville, R.; Bartel, T.J.

    2015-01-01

    Nuclear fuel encounters severe thermomechanical environments. Its mechanical response is profoundly influenced by an underlying heterogeneous microstructure but also inherently dependent on the temperature and stress level histories. The ability to adequately simulate the response of such microstructures, to elucidate the associated macroscopic response in such extreme environments is crucial for predicting both performance and transient fuel mechanical responses. This chapter discusses key physical phenomena and the status of current modelling techniques to evaluate and predict fuel deformations: creep, swelling, cracking and pellet-clad interaction. This chapter only deals with nuclear fuel; deformations of cladding materials are discussed elsewhere. An obvious need for a multi-physics and multi-scale approach to develop a fundamental understanding of properties of complex nuclear fuel materials is presented. The development of such advanced multi-scale mechanistic frameworks should include either an explicit (domain decomposition, homogenisation, etc.) or implicit (scaling laws, hand-shaking,...) linkage between the different time and length scales involved, in order to accurately predict the fuel thermomechanical response for a wide range of operating conditions and fuel types (including Gen-IV and TRU). (authors)

  1. Handling encapsulated spent fuel in a geologic repository environment

    International Nuclear Information System (INIS)

    Ballou, L.B.

    1983-02-01

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

  2. Overview of the US spent nuclear fuel program

    International Nuclear Information System (INIS)

    Hurt, W.L.

    1999-01-01

    This report, Overview of the United States Spent Nuclear Fuel Program, December, 1997, summarizes the U.S. strategy for interim management and ultimate disposition of spent nuclear fuel from research and test reactors. The key elements of this strategy include consolidation of this spent nuclear fuel at three sites, preparation of the fuel for geologic disposal in road-ready packages, and low-cost dry interim storage until the planned geologic repository is opened. The U.S. has a number of research programs in place that are intended to Provide data and technologies to support both characterization and disposition of the fuel. (author)

  3. 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

  4. Nuclear fuel storage

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1981-01-01

    A nuclear fuel storage apparatus for use in a water-filled pool is fabricated of a material such as stainless steel in the form of an egg crate structure having vertically extending openings. Fuel may be stored in this basic structure in a checkerboard pattern with high enrichment fuel, or in all openings when the fuel is of low effective enrichment. Inserts of a material such as stainless steel are adapted to fit within these openings so that a water gap and, therefore, a flux trap is formed between adjacent fuel storage locations. These inserts may be added at a later time and fuel of a higher enrichment may be stored in each opening. When it is desired to store fuel of still greater enrichment, poison plates may be added to the water gap formed by the installed insert plates, or substituted for the insert plates. Alternately, or in addition, fuel may be installed in high neutron absorption poison boxes which surround the fuel assembly. The stainless steel inserts and the poison plates are each not required until the capacity of the basic egg crate structure is approached. Purchase of these items can, therefore, be deferred for many years. Should the fuel to be stored be of higher enrichment than initially forecast, the deferred decision on the poison plates makes it possible to obtain increased poison in the plates to satisfy the newly discovered requirement

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

    Science.gov (United States)

    Pang, Bo; Becker, Frank

    2017-04-28

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

  6. 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

  7. Nuclear fuel element

    International Nuclear Information System (INIS)

    Knowles, A.N.

    1979-01-01

    A nuclear fuel-containing body for a high temperature gas cooled nuclear reactor is described which comprises a flat plate in which the nuclear fuel is contained as a dispersion of fission product-retaining coated fuel particles in a flat sheet of graphitic or carbonaceous matrix material. The flat sheet is clad with a relatively thin layer of unfuelled graphite bonded to the sheet by being formed initially from a number of separate preformed graphitic artefacts and then platen-pressed on to the exterior surfaces of the flat sheet, both the matrix material and the artefacts being in a green state, to enclose the sheet. A number of such flat plates are supported edge-on to the coolant flow in the bore of a tube made of neutron moderating material. Where a number of tiers of plates are superimposed on one another, the abutting edges are chamfered to reduce vibration. (author)

  8. Nuclear fuel strategies

    International Nuclear Information System (INIS)

    Rippon, S.

    1989-01-01

    The paper reports on two international meetings on nuclear fuel strategies, one organised by the World Nuclear Fuel Market in Seville (Spain) October 1988, and the other organised by the American and European nuclear societies in Washington (U.S.A.) November 1988. At the Washington meeting a description was given of the uranium supply and demand market, whereas free trade in uranium was considered in Seville. Considerable concern was expressed at both meetings on the effect on the uranium and enrichment services market of very low prices for spot deals being offered by China and the Soviet Union. Excess enrichment capacity, the procurement policies of the USA and other countries, and fuel cycle strategies, were also discussed. (U.K.)

  9. Tunnel boring an alternative method in construction of spent fuel repositories

    International Nuclear Information System (INIS)

    Christersson, Jukka

    1984-05-01

    In projecting of the final disposal of nuclear waste in geological formations a great importance should be paid to the selection of the tunneling method. The environment of the chosen repository area should not be exposed to any but as minor disturbances as possible by the excavation method applied. This study approaches full face tunneling methods as an alternative to conventional drill-and-blast methods in the construction of spent fuel repository tunnels. According to experiences up till now it is obvious, that tunnelboring today is fully capable technically competing with conventional tunneling methods, even in the hardest granitic rocks. The most important advantages, it provides for the construction of repositories, are: The methods does not produce any damage in the surrounding rock. Possibility to use placement techniques, which do not require preparing of additive repository holes for the fuel elements. Saving in the use of expensive filling material. The fact, that tunnel boring in hard rock is an expensive alternative, is still valid. Constuction of straight lined tunnels in unfractured rocks by tunnel boring would cost about 30-40% more than by conventional methods. The lay out arrangement of bored tunnels still have a great influence on tunnel boring machine's economy. Due to this it would be round 40-70% more expensive method in the construction of spent fuel repositories. However intensive development w is being carried out to eliminate these limitations and to make machines more flexible. Future trends in tunnel boring look good at the moment. The number of sold units has been increasing and new applications have widen out during last ten years. Harder and more abrasive rocks can now be bored than ever before and the trend seems to continue. It also looks like the cost difference in the hardest rocks is firmly getting smaller and smaller all the time. (author)

  10. Direct Investigations of the Immobilization of Radionuclides in the Alteration Products of Spent Nuclear Fuel

    International Nuclear Information System (INIS)

    Burns, Peter C.; Finch, Robert J.; Wronkiewicz, David J.

    2004-01-01

    Safe disposal of the nation's nuclear waste in a geological repository involves unique scientific and engineering challenges owing to the very long-lived radioactivity of the waste. The repository must retain a variety of radionuclides that have vastly different chemical characters for several thousand years. Most of the radioactivity that will be housed in the proposed repository at Yucca Mountain will be associated with spent nuclear fuel, much of which is derived from commercial reactors. DOE is custodian of approximately 8000 tons of spent nuclear fuel that is also intended for eventual disposal in a geological repository. Unlike the spent fuel from commercial reactors, the DOE fuel is diverse in composition with more than 250 varieties. Safe disposal of spent fuel requires a detailed knowledge of its long-term behavior under repository conditions, as well as the fate of radionuclides released from the spent fuel as waste containers are breached

  11. Nuclear fuel element

    International Nuclear Information System (INIS)

    Penrose, R.T.; Thompson, J.R.

    1976-01-01

    A method of protecting the cladding of a nuclear fuel element from internal attack and a nuclear fuel element for use in the core of a nuclear reactor are disclosed. The nuclear fuel element has disposed therein an additive of a barium-containing material and the barium-containing material collects reactive gases through chemical reaction or adsorption at temperatures ranging from room temperature up to fuel element plenum temperatures. The additive is located in the plenum of the fuel element and preferably in the form of particles in a hollow container having a multiplicity of gas permeable openings in one portion of the container with the openings being of a size smaller than the size of the particles. The openings permit gases and liquids entering the plenum to contact the particles. The additive is comprised of elemental barium or a barium alloy containing one or more metals in addition to barium such as aluminum, zirconium, nickel, titanium and combinations thereof. 6 claims, 3 drawing figures

  12. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Assessment of radionuclide release scenarios for the repository system 2012

    International Nuclear Information System (INIS)

    2012-12-01

    Assessment of Radionuclide Release Scenarios sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of presenting an assessment of the repository system scenarios leading to radionuclide releases that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For each scenario, a range of calculation cases, also identified in Formulation of Radionuclide Release Scenarios, has been analysed, complemented by Monte Carlo simulations, a probabilistic sensitivity analysis and other supporting calculations. The calculation cases and analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in Performance Assessment. Quality control and assurance measures have been adopted to ensure transparency and traceability of the calculations performed and hence to promote confidence in the analysis of the calculation cases. The calculation cases each consider a single, failed canister, where three possible modes of failure are addressed: (1) the presence of an initial penetrating defect in the copper overpack of the canister, (2) corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion, (3) shear movement on a fracture intersecting a deposition hole. The likelihood and consequences of multiple canister failure occurring during the assessment time frame are also considered. In particular, the analyses consider: The likelihood and consequences of there being multiple canisters with initial penetrating defects; The consequences if canister failure due to corrosion following buffer erosion were to occur; and The low annual probability of there being an earthquake large enough to give rise to canister failure due to rock shear movements and the potential consequences of such an earthquake, taking into

  13. Safety case for the disposal of spent nuclear fuel at Olkiluoto. Assessment of radionuclide release scenarios for the repository system 2012

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2012-12-15

    Assessment of Radionuclide Release Scenarios sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of presenting an assessment of the repository system scenarios leading to radionuclide releases that have been identified in Formulation of Radionuclide Release Scenarios. A base scenario, variant scenarios and disturbance scenarios are considered. For each scenario, a range of calculation cases, also identified in Formulation of Radionuclide Release Scenarios, has been analysed, complemented by Monte Carlo simulations, a probabilistic sensitivity analysis and other supporting calculations. The calculation cases and analyses take into account major uncertainties in the initial state of the barriers and possible paths for the evolution of the repository system identified in Performance Assessment. Quality control and assurance measures have been adopted to ensure transparency and traceability of the calculations performed and hence to promote confidence in the analysis of the calculation cases. The calculation cases each consider a single, failed canister, where three possible modes of failure are addressed: (1) the presence of an initial penetrating defect in the copper overpack of the canister, (2) corrosion of the copper overpack, which occurs most rapidly in scenarios in which buffer density is reduced, e.g. by erosion, (3) shear movement on a fracture intersecting a deposition hole. The likelihood and consequences of multiple canister failure occurring during the assessment time frame are also considered. In particular, the analyses consider: The likelihood and consequences of there being multiple canisters with initial penetrating defects; The consequences if canister failure due to corrosion following buffer erosion were to occur; and The low annual probability of there being an earthquake large enough to give rise to canister failure due to rock shear movements and the potential consequences of such an earthquake

  14. Nuclear fuel cycle

    International Nuclear Information System (INIS)

    Niedrig, T.

    1987-01-01

    Nuclear fuel supply is viewed as a buyer's market of assured medium-term stability. Even on a long-term basis, no shortage is envisaged for all conceivable expansion schedules. The conversion and enrichment facilities developed since the mid-seventies have done much to stabilize the market, owing to the fact that one-sided political decisions by the USA can be counteracted efficiently. In view of the uncertainties concerning realistic nuclear waste management strategies, thermal recycling and mixed oxide fuel elements might increase their market share in the future. Capacities are being planned accordingly. (orig.) [de

  15. 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

  16. Nuclear fuel element

    International Nuclear Information System (INIS)

    Grossman, L.N.; Levin, H.A.

    1975-01-01

    A nuclear fuel element has disposed therein an alloy having the essential components of nickel, titanium and zirconium, and the alloy reacts with water, water vapor and reactive gases at reactor ambient temperatures. The alloy is disposed in the plenum of the fuel element in the form of particles in a hollow gas permeable container having a multiplicity of openings of size smallr than the size of the particles. The container is preferably held in the spring in the plenum of the fuel element. (E.C.B.)

  17. Nuclear fuel elements

    International Nuclear Information System (INIS)

    Kawada, Toshiyuki; Hirayama, Satoshi; Yoneya, Katsutoshi.

    1980-01-01

    Purpose: To enable load-depending operation as well as moderation for the restriction of operation conditions in the present nuclear reactors, by specifying the essential ingredients and the total weight of the additives to UO 2 fuel substances. Constitution: Two or more additives selected from Al 2 O 3 , B 2 O, CaO, MgO, SiO 2 , Na 2 O and P 2 O 5 are added by the total weight of 2 - 5% to fuel substances consisting of UO 2 or a mixture of UO 2 and PuO 2 . When the mixture is sintered, the strength of the fuel elements is decreased and the fuel-cladding interactions due to the difference in the heat expansion coefficients between the ceramic fuel elements and the metal claddings are decreased to a substantially harmless degree. (Horiuchi, T.)

  18. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Domoto, Noboru; Masuda, Hiroyuki

    1989-01-01

    In a nuclear fuel assembly loaded with a plurality of fuel rods, the inside of a fuel rod disposed at a high neutron flux region is divided into an inner region and an outer region, and more burnable poisons are mixed in the inner region than in the outer region. Alternatively, the central portion of a pellet disposed in a high neutron flux region is made hollow, in which burnable poisons are charged. This can prevent neutron infinite multiplication factor from decreasing extremely at the initial burning stage. Further, the burnable poisons are not rapidly burnt completely and local peaking coefficient can be controlled. Accordingly, in a case of suppressing a predetermined excess reactivity by using a fuel rod incorporated with the burnable poison, the fuel economy can be improved more and the reactor core controllability can also be improved as compared with the usual case. (T.M.)

  19. Sensitivity analysis of biospheric behaviour of radionuclides released from nuclear waste repositories

    International Nuclear Information System (INIS)

    Korhonen, R.; Savolainen, I.; Suolanen, V.

    1985-01-01

    Sensitivity studies of biospheric behaviour of radionuclides released from a planned spent nuclear fuel repository are performed. Sensitivity of radionuclide concentrations in biosphere and that of radiation doses to solubility of nuclides, to sedimentation rate and to intercompartmental water exchange are studied. Solubility has pronounced effect on the sedimentation on the local scale, and in general, sediment sinks were found to be of major importance in the biospheric behaviour of radionuclides. (author)

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

    International Nuclear Information System (INIS)

    Myatt, J.; Ward, M.D.

    1995-01-01

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

  1. The nuclear fuel cycle

    International Nuclear Information System (INIS)

    Anon.

    1975-01-01

    The papers presented at the International Conference on The Nuclear Fuel Cycle, held at Stockholm, 28 to 31 October 1975, are reviewed. The meeting, organised by the U.S. Atomic Industrial Forum, and the Swedish Nuclear Forum, was concerned more particularly with economic, political, social and commercial aspects than with tecnology. The papers discussed were considered under the subject heading of current status, uranium resources, enrichment, and reprocessing. (U.K.)

  2. Nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    1975-12-01

    The papers presented at the International Conference on The Nuclear Fuel Cycle, held at Stockholm, 28 to 31 October 1975, are reviewed. The meeting, organised by the U.S. Atomic Industrial Forum, and the Swedish Nuclear Forum, was concerned more particularly with economic, political, social and commercial aspects than with tecnology. The papers discussed were considered under the subject heading of current status, uranium resources, enrichment, and reprocessing.

  3. Encapsulating spent nuclear fuel

    International Nuclear Information System (INIS)

    Fleischer, L.R.; Gunasekaran, M.

    1979-01-01

    A system is described for encapsulating spent nuclear fuel discharged from nuclear reactors in the form of rods or multi-rod assemblies. The rods are completely and contiguously enclosed in concrete in which metallic fibres are incorporated to increase thermal conductivity and polymers to decrease fluid permeability. This technique provides the advantage of acceptable long-term stability for storage over the conventional underwater storage method. Examples are given of suitable concrete compositions. (UK)

  4. 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

  5. Nuclear fuel cycle information workshop

    International Nuclear Information System (INIS)

    1983-01-01

    This overview of the nuclear fuel cycle is divided into three parts. First, is a brief discussion of the basic principles of how nuclear reactors work; second, is a look at the major types of nuclear reactors being used and world-wide nuclear capacity; and third, is an overview of the nuclear fuel cycle and the present industrial capability in the US

  6. World Nuclear Association position statement: Safe management of nuclear waste and used nuclear fuel

    International Nuclear Information System (INIS)

    Saint-Pierre, Sylvain

    2006-01-01

    experience and knowledge will only reinforce this already robust safety record. The current generation of humankind must not abdicate its duty to employ available, affordable and scientifically reliable means to meet its responsibility for disposing safely of nuclear waste and used nuclear fuel. Continued development of deep geological repositories and their operation beginning in this decade is essential if this responsibility is to be met. The nuclear industry has demonstrated that it accepts the management responsibility for nuclear waste and used nuclear fuel as a fundamental duty and is prepared to fulfill its obligation with professional dedication and technological skill. The following annexes complete the document: - Annex A, A Broader Perspective on Nuclear Waste and Used Nuclear Fuel; - Annex B, Common Mis-perceptions about Nuclear Waste; - Annex C, Nuclear Waste and Used Nuclear Fuel Repositories; Annex D, Nuclear Waste: A Surprisingly Small Burden; Annex E, Background Information

  7. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Hirano, Yasushi; Hirukawa, Koji; Sakurada, Koichi.

    1994-01-01

    A bundle of fuel rods is divided into four fuel rod group regions of small fuel rod bundles by a cross-shaped partitioning structure consisting of paired plate-like structures which connect two opposing surfaces of a channel box. A water removing material with less neutron absorption (for example, Zr or a Zr alloy) or a solid moderator is inserted and secured to a portion of a non-boiling water region interposed between the paired plate-like structure. It has a structure that light water flows to the region in the plate-like structure. The volume, density or composition of the water removing material is controlled depending on the composition of the fuels, to change the moderating characteristics of neutrons in the non-boiling water region. This can easily moderate the difference of nuclear characteristics between each of fuel assemblies using fuel materials of different fuel compositions. Further, the reactivity control effect of the burnable poisons can be enhanced without worsening fuel economy or linear power density. (I.N.)

  8. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Delafosse, Jacques.

    1977-01-01

    This invention relates to a nuclear fuel assembly for a light or heavy water reactor, or for a fast reactor of the kind with a bundle of cladded pins, maintained parallel to each other in a regular network by an assembly of separate supporting grids, fitted with elastic bearing surfaces on these pins [fr

  9. Nuclear fuel pellets

    International Nuclear Information System (INIS)

    Larson, R.I.; Brassfield, H.C.

    1981-01-01

    Increased strength and physical durability in green bodies or pellets formed of particulate nuclear fuel oxides is achieved by inclusion of a fugitive binder which is ammonium bicarbonate, bicarbonate carbomate, carbomate, sesquicarbonate or mixtures thereof. Ammonium oxadate may be included as pore former. (author)

  10. Transporting spent nuclear fuel: an overview

    International Nuclear Information System (INIS)

    1986-03-01

    Although high-level radioactive waste from both commercial and defense activities will be shipped to the repository, this booklet focuses on various aspects of transporting commercial spent fuel, which accounts for the majority of the material to be shipped. The booklet is intended to give the reader a basic understanding of the following: the reasons for transportation of spent nuclear fuel, the methods by which it is shipped, the safety and security precautions taken for its transportation, emergency response procedures in the event of an accident, and the DOE program to develop a system uniquely appropriate to NWPA transportation requirements

  11. 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.

  12. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Ito, Arata; Wakamatsu, Mitsuo.

    1976-01-01

    Object: To permit the coolant in an FBR type reactor to enter from the entrance nozzle into a nuclear fuel assembly without causing cavitation. Structure: In a nuclear fuel assembly, which comprises a number of thin fuel pines bundled together at a uniform spacing and enclosed within an outer cylinder, with a handling head connected to an upper portion of the outer cylinder and an entrance nozzle connected to a lower portion of the cylinder, the inner surface of the entrance nozzle is provided with a buffer member and an orifice successively in the direction of flow of the coolant. The coolant entering from a low pressure coolant chamber into the entrance nozzle strikes the buffer member and is attenuated, and thereafter flows through an orifice into the outer cylinder. (Horiuchi, T.)

  13. Nuclear fuel element

    International Nuclear Information System (INIS)

    Hirama, H.

    1978-01-01

    A nuclear fuel element comprises an elongated tube having upper and lower end plugs fixed to both ends thereof and nuclear fuel pellets contained within the tube. The fuel pellets are held against the lower end plug by a spring which is supported by a setting structure. The setting structure is maintained at a proper position at the middle of the tube by a wedge effect caused by spring force exerted by the spring against a set of balls coacting with a tapered member of the setting structure thereby wedging the balls against the inner wall of the tube, and the setting structure is moved free by pushing with a push bar against the spring force so as to release the wedge effect

  14. 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)

  15. Integral nuclear fuel element assembly

    International Nuclear Information System (INIS)

    Schluderberg, D. C.

    1985-01-01

    An integral nuclear fuel element assembly utilizes longitudinally finned fuel pins. The continuous or interrupted fins of the fuel pins are brazed to fins of juxtaposed fuel pins or directly to the juxtaposed fuel pins or both. The integrally brazed fuel assembly is designed to satisfy the thermal and hydraulic requirements of a fuel assembly lattice having moderator to fuel atom ratios required to achieve high conversion and breeding ratios

  16. Nuclear fuel cycle techniques

    International Nuclear Information System (INIS)

    Pecqueur, Michel; Taranger, Pierre

    1975-01-01

    The production of fuels for nuclear power plants involves five principal stages: prospecting of uranium deposits (on the ground, aerial, geochemical, geophysical, etc...); extraction and production of natural uranium from the deposits (U content of ores is not generally high and a chemical processing is necessary to obtain U concentrates); production of 235 U enriched uranium for plants utilizing this type of fuel (a description is given of the gaseous diffusion process widely used throughout the world and particularly in France); manufacture of suitable fuel elements for the different plants; reprocessing of spent fuels for the purpose of not only recovering the fissile materials but also disposing safely of the fission products and other wastes [fr

  17. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    Vikhorev, Yu.V.; Biryukov, G.I.; Kirilyuk, N.A.; Lobanov, V.N.

    1977-01-01

    A fuel assembly is proposed for nuclear reactors allowing remote replacement of control rod bundles or their shifting from one assembly to another, i.e., their multipurpose use. This leads to a significant increase in fuel assembly usability. In the fuel assembly the control rod bundle is placed in guide tube channels to which baffles are attached for fuel element spacing. The remote handling of control rods is provided by a hollow cylinder with openings in its lower bottom through which the control rods pass. All control rods in a bundle are mounted to a cross beam which in turn is mounted in the cylinder and is designed for grasping the whole rod bundle by a remotely controlled telescopic mechanism in bundle replacement or shifting. (Z.M.)

  18. Experience with nuclear fuel utilization in Bulgaria

    Energy Technology Data Exchange (ETDEWEB)

    Harizanov, Y [Committee on the Use of Atomic Energy for Peaceful Purposes, Sofia (Bulgaria)

    1997-12-01

    The presentation on experience with nuclear fuel utilization in Bulgaria briefly reviews the situation with nuclear energy in Bulgaria and then discusses nuclear fuel performance (amount of fuel loaded, type of fuel, burnup, fuel failures, assemblies deformation). 2 tabs.

  19. Nuclear fuel cycle system analysis

    International Nuclear Information System (INIS)

    Ko, W. I.; Kwon, E. H.; Kim, S. G.; Park, B. H.; Song, K. C.; Song, D. Y.; Lee, H. H.; Chang, H. L.; Jeong, C. J.

    2012-04-01

    The nuclear fuel cycle system analysis method has been designed and established for an integrated nuclear fuel cycle system assessment by analyzing various methodologies. The economics, PR(Proliferation Resistance) and environmental impact evaluation of the fuel cycle system were performed using improved DB, and finally the best fuel cycle option which is applicable in Korea was derived. In addition, this research is helped to increase the national credibility and transparency for PR with developing and fulfilling PR enhancement program. The detailed contents of the work are as follows: 1)Establish and improve the DB for nuclear fuel cycle system analysis 2)Development of the analysis model for nuclear fuel cycle 3)Preliminary study for nuclear fuel cycle analysis 4)Development of overall evaluation model of nuclear fuel cycle system 5)Overall evaluation of nuclear fuel cycle system 6)Evaluate the PR for nuclear fuel cycle system and derive the enhancement method 7)Derive and fulfill of nuclear transparency enhancement method The optimum fuel cycle option which is economical and applicable to domestic situation was derived in this research. It would be a basis for establishment of the long-term strategy for nuclear fuel cycle. This work contributes for guaranteeing the technical, economical validity of the optimal fuel cycle option. Deriving and fulfillment of the method for enhancing nuclear transparency will also contribute to renewing the ROK-U.S Atomic Energy Agreement in 2014

  20. 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

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

    Science.gov (United States)

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

    2017-12-01

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

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

    International Nuclear Information System (INIS)

    Baeckblom, Goeran; Almen, Karl-Erik

    2004-03-01

    to: obtain knowledge of undisturbed conditions in nature and their seasonal variations (baseline) in order to identify and evaluate the impact of activities related to the deep repository during different phases, obtain a better understanding of the function of the deep repository system to support the safety account and to test models and assumptions, monitor the environmental impact of the deep repository, provide evidence that the working environment is safe with regard to radiological and non-radiological effects, show that requirements on radioactive waste verification (safeguards) are fulfilled. The monitoring is concerned with bedrock conditions before and during construction and operation of the facilities, active design to engineer the underground facilities based on monitoring results during construction, the safe and environmental construction and operation of facilities. Experience exists from monitoring of the barrier function at SFR, the final repository for low - and intermediate level waste and at the Aespoe Hard Rock Laboratory and monitoring for safeguard at CLAB, the interim storage for spent nuclear fuel. The know-how on monitoring relates to all aspects from design, installation, operation and maintenance to decommissioning of systems. This report provides an overview of the features, processes and parameters that are collected during the site investigations to establish the Primary Baseline conditions for monitoring prior to the construction of the repository. It is also proposed that the monitoring programme should at least entail the following elements: objectives for the monitoring programme, scope for the monitoring (criteria for selection of issues to be monitored, identification of the properties, processes, phenomena and observable quantities to be monitored), identification on what methods to be used, operation of the monitoring system (identification of the duration and frequency of monitoring, including criteria for when monitoring may

  3. 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

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

    International Nuclear Information System (INIS)

    2010-01-01

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

  5. Calculations of the Temperature Evolution of a Repository for Spent Fuel in Crystalline and Sedimentary Rocks

    International Nuclear Information System (INIS)

    Sato, R.; Sasaki, T.; Ando, K.; Smith, P.A.; Schneider, J.W.

    1998-08-01

    Thermal evolution is a factor influencing repository design, and must be considered in safety assessment, since many of the processes that affect the long-term safety are temperature dependent. This report presents calculations of the thermal evolution of a repository for spent nuclear fuel. The calculations are based on a provisional repository near-field design in which spent fuel is encapsulated in composite copper-steel canisters, which are emplaced centrally along the horizontal axes of repository tunnels, with the space around the canisters backfilled with bentonite. The temperature of these near-field components varies with time, due to the radiogenic heat produced by the spent fuel. The rate of heat production per canister depends on the initial composition of the fuel, its reactor history, the period of intermediate storage before final disposal and the loading of the canisters. The rate decreases with time, as shorter-lived radionuclides decay. The base-case calculation considers spent fuel that is assumed to generate 1000 W per canister, 40 years after unloading of the fuel from the reactor. The results of the base case calculation indicate that the temperatures at the bentonite/host rock interface, at the centre of the bentonite and at the bentonite/canister interface rise to 98 o C, 103 o C and 126 o C, respectively, before declining towards the ambient temperature of the host rock which, in the base case, is taken to be the crystalline basement of Northern Switzerland. In addition to the base case, parameter variations are examined that investigate the sensitivity of thermal evolution to alternative heat output, design specifications and to uncertainties in material properties. Key findings include (i), that an increase in heat generation to 1500 W per canister 40 years after unloading results in a significant increase of repository temperatures (e.g. at the bentonite/host rock interface, an increase of 22 o C is observed), (ii), that a decrease in

  6. Nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    1982-01-01

    This film for a general audience deals with nuclear fuel waste management in Canada, where research is concentrating on land based geologic disposal of wastes rather than on reprocessing of fuel. The waste management programme is based on cooperation of the AECL, various universities and Ontario Hydro. Findings of research institutes in other countries are taken into account as well. The long-term effects of buried radioactive wastes on humans (ground water, food chain etc.) are carefully studied with the help of computer models. Animated sequences illustrate the behaviour of radionuclides and explain the idea of a multiple barrier system to minimize the danger of radiation hazards

  7. Nuclear reactor fuel elements

    International Nuclear Information System (INIS)

    Hindle, E. D.

    1984-01-01

    An array of rods is assembled to form a fuel element for a pressurized water reactor, the rods comprising zirconium alloy sheathed nuclear fuel pellets and containing helium. The helium gas pressure is selected for each rod so that it differs substantially from the helium gas pressure in its closest neighbors. In a preferred arrangement the rods are arranged in a square lattice and the helium gas pressure alternates between a relatively high value and a relatively low value so that each rod has as its closest neighbors up to four rods containing helium gas at the other pressure value

  8. Nuclear reactor fuel elements

    Energy Technology Data Exchange (ETDEWEB)

    Hindle, E. D.

    1984-10-16

    An array of rods is assembled to form a fuel element for a pressurized water reactor, the rods comprising zirconium alloy sheathed nuclear fuel pellets and containing helium. The helium gas pressure is selected for each rod so that it differs substantially from the helium gas pressure in its closest neighbors. In a preferred arrangement the rods are arranged in a square lattice and the helium gas pressure alternates between a relatively high value and a relatively low value so that each rod has as its closest neighbors up to four rods containing helium gas at the other pressure value.

  9. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    1975-01-01

    The nuclear fuel assembly described includes a cluster of fuel elements supported at a distance from each other so that their axes are parallel in order to establish secondary channels between them reserved for the coolant. Several ducts for an auxiliary cooling fluid are arranged in the cluster. The wall of each duct is pierced with coolant ejection holes which are placed circumferentially to a pre-determined pattern established according to the position of the duct in the cluster and by the axial distance of the ejection hole along the duct. This assembly is intended for reactors cooled by light or heavy water [fr

  10. 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.

  11. Ethical considerations surrounding nuclear waste repository siting and mitigation

    International Nuclear Information System (INIS)

    Peters, T.F.

    1983-01-01

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

  12. Nuclear fuel activities in Canada

    Energy Technology Data Exchange (ETDEWEB)

    Cox, D S [Fuel Development Branch, Chalk River Labs., AECL (Canada)

    1997-12-01

    Nuclear fuel activities in Canada are considered in the presentation on the following directions: Canadian utility fuel performance; CANDU owner`s group fuel programs; AECL advanced fuel program (high burnup fuel behaviour and development); Pu dispositioning (MOX) activities. 1 tab.

  13. Modelling spent fuel and HLW behaviour in repository conditions

    Energy Technology Data Exchange (ETDEWEB)

    Esparza, A M; Esteban, J A

    2003-07-01

    The aim of this report is to give the reader an overall insight of the different models, which are used to predict the long-term behaviour of the spent fuels and HLW disposed in a repository. The models must be established on basic data and robust kinetics describing the mechanisms controlling spent fuel alteration/dissolution in a repository. The UO2 matrix, or source term, contains embedded in it the , majority of radionuclides of the spent fuel (some are in the gap cladding). For this reason the SF radionuclides release models play a significant role in the performance assessment of radioactive waste disposal. The differences existing between models published in the literature are due to the conceptual understanding of the processes and the degree of the conservatism used with the parameter values, and the boundary conditions. They mainly differ in their level of simplification and their final objective. Sometimes are focused the show compliance with regulatory requirements, other to support decision making, to increase the level of confidence of public and scientific community, could be empirical, semi-empirical or analytical. The models take into account the experimental results from radionuclides releases and their extrapolation to the very long term. Its necessary a great statistics for have a representative dissolution rate, due at the number of experimental results is not very high and many of them show a great scatter, independently of theirs different compositions by axial and radial variations, due to linear power or local burnup. On the other hand, it is difficult to predict the spent fuel behaviour over the long term, based in short term experiments. In this report is given a little description of the radionuclides distribution in the spent fuel and also in the cladding/pellet gap, grain boundary, cracks and rim zones (the matrix rim zone can be considered with an especial characteristics very different to the rest of the spent fuel), and structural

  14. Modelling spent fuel and HLW behaviour in repository conditions

    International Nuclear Information System (INIS)

    Esparza, A. M.; Esteban, J. A.

    2003-01-01

    The aim of this report is to give the reader an overall insight of the different models, which are used to predict the long-term behaviour of the spent fuels and HLW disposed in a repository. The models must be established on basic data and robust kinetics describing the mechanisms controlling spent fuel alteration/dissolution in a repository. The UO2 matrix, or source term, contains embedded in it the , majority of radionuclides of the spent fuel (some are in the gap cladding). For this reason the SF radionuclides release models play a significant role in the performance assessment of radioactive waste disposal. The differences existing between models published in the literature are due to the conceptual understanding of the processes and the degree of the conservatism used with the parameter values, and the boundary conditions. They mainly differ in their level of simplification and their final objective. Sometimes are focused the show compliance with regulatory requirements, other to support decision making, to increase the level of confidence of public and scientific community, could be empirical, semi-empirical or analytical. The models take into account the experimental results from radionuclides releases and their extrapolation to the very long term. Its necessary a great statistics for have a representative dissolution rate, due at the number of experimental results is not very high and many of them show a great scatter, independently of theirs different compositions by axial and radial variations, due to linear power or local burnup. On the other hand, it is difficult to predict the spent fuel behaviour over the long term, based in short term experiments. In this report is given a little description of the radionuclides distribution in the spent fuel and also in the cladding/pellet gap, grain boundary, cracks and rim zones (the matrix rim zone can be considered with an especial characteristics very different to the rest of the spent fuel), and structural

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

    International Nuclear Information System (INIS)

    Ahagen, H.

    1993-01-01

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

  16. Pyrochemical processing of DOE spent nuclear fuel

    International Nuclear Information System (INIS)

    Laidler, J.J.

    1995-01-01

    A compact, efficient method for conditioning spent nuclear fuel is under development. This method, known as pyrochemical processing, or open-quotes pyroprocessing,close quotes provides a separation of fission products from the actinide elements present in spent fuel and further separates pure uranium from the transuranic elements. The process can facilitate the timely and environmentally-sound treatment of the highly diverse collection of spent fuel currently in the inventory of the United States Department of Energy (DOE). The pyroprocess utilizes elevated-temperature processes to prepare spent fuel for fission product separation; that separation is accomplished by a molten salt electrorefining step that provides efficient (>99.9%) separation of transuranics. The resultant waste forms from the pyroprocess, are stable under envisioned repository environment conditions and highly leach-resistant. Treatment of any spent fuel type produces a set of common high-level waste forms, one a mineral and the other a metal alloy, that can be readily qualified for repository disposal and avoid the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

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

    International Nuclear Information System (INIS)

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

    2002-01-01

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

  18. Nuclear fuel brokerage

    International Nuclear Information System (INIS)

    Hoffman, J.; Schreiber, K.

    1985-01-01

    Making available nuclear fuels on the spot market, especially uranium in various compounds and processing stages, has become an important service rendered nuclear power plant operators. A secondary market has grown, both for natural uranium and for separative work, the conditions and transactions of which require a comprehensive overview of what is going on, especially also in connection with possibilities to terminate in a profitable manner existing contracts. This situation has favored the activity of brokers with excellent knowledge of the market, who are able to handle the complicated terms and conditions in an optimum way. (orig.) [de

  19. Radionuclide release from PWR fuels in a reference tuff repository groundwater

    International Nuclear Information System (INIS)

    Wilson, C.N.; Oversby, V.M.

    1985-03-01

    The Nevada Nuclear Waste Storage Investigations Project (NNWSI) is studying the suitability of the welded devitrified Topopah Spring tuff at Yucca Mountain, Nye County, Nevada, for potential use as a high-level nuclear waste repository. In support of the Waste Package task of NNWSI, tests have been conducted under ambient air environment to measure radionuclide release from two pressurized water reactor (PWR) spent fuels in water obtained from the J-13 well near the Yucca Mountain site. Four specimen types, representing a range of fuel physical conditions that may exist in a failed waste canister containing a limited amount of water were tested. The specimen types were: fuel rod sections split open to expose bare fuel particles; rod sections with water-tight end fittings with a 2.5-cm long by 150-μm wide slit through the cladding; rod sections with water-tight end fittings and two 200-μm-diameter holes through the cladding; and undefected rod segments with water-tight end fittings. Radionuclide release results from the first 223-day test runs on H.B. Robinson spent fuel specimens in J-13 water are reported and compared to results from a previous test series in which similar Turkey Point reactor spent fuel specimens were tested on deionized water. Selected initial results are also given for Turkey Point fuel specimens tested on J-13 water. Results suggest that the actinides Pu, Am, Cm and Np are released congruently with U as the UO 2 spent fuel matrix dissolves. Fractional release of 137 Cs and 99 Tc was greater than that measured for the actinides. Generally, lower radionuclide releases were measured for the H.B. Robinson fuel in J-13 water than for Turkey Point Fuel in deionized water. 8 references, 7 figures, 9 tables

  20. Compact nuclear fuel storage

    International Nuclear Information System (INIS)

    Kiselev, V.V.; Churakov, Yu.A.; Danchenko, Yu.V.; Bylkin, B.K.; Tsvetkov, S.V.

    1983-01-01

    Different constructions of racks for compact storage of spent fuel assemblies (FA) in ''coolin''g pools (CP) of NPPs with the BWR and PWR type reactors are described. Problems concerning nuclear and radiation safety and provision of necessary thermal conditions arising in such rack design are discussed. It is concluded that the problem of prolonged fuel storage at NPPs became Very actual for many countries because of retapdation of the rates of fuel reprocessing centers building. Application of compact storage racks is a promising solution of the problem of intermediate FA storage at NPPs. Such racks of stainless boron steel and with neutron absorbers in the from of boron carbide panels enable to increase the capacity of the present CP 2-2.6 times, and the period of FA storage in them up to 5-10 years

  1. Nuclear reactor fuel assembly

    International Nuclear Information System (INIS)

    1975-01-01

    A description is given of a nuclear reactor fuel assembly comprising a cluster of fuel elements supported by transversal grids so that their axes are parallel to and at a distance from each other, in order to establish interstices for the axial flow of a coolant. At least one of the interstices is occupied by an axial duct reserved for an auxiliary cooling fluid and is fitted with side holes through which the auxiliary cooling fluid is sprayed into the cluster. Deflectors extend as from a transversal grid in a position opposite the holes to deflect the cooling fluid jet towards those parts of the fuel elements that are not accessible to the auxiliary coolant. This assembly is intended for reactors cooled by light or heavy water [fr

  2. Nuclear fuel pin

    International Nuclear Information System (INIS)

    Hartley, Kenneth; Moulding, T.L.J.; Rostron, Norman.

    1979-01-01

    Fuel pin for use in fast breeder nuclear reactors containing fissile and fertile areas of which the fissile and fertile materials do not mix. The fissile material takes the shape of large and small diameter microspheres (the small diameter microspheres can pass through the interstices between the large microspheres). The barrier layers being composed of microspheres with a diameter situated between those of the large and small microspheres ensure that the materials do not mix [fr

  3. Alternative nuclear fuel cycles

    International Nuclear Information System (INIS)

    Till, C.E.

    1979-01-01

    This diffuse subject involves value judgments that are political as well as technical, and is best understood in that context. The four questions raised here, however, are mostly from the technical viewpoints: (1) what are alternative nuclear fuel cycles; (2) what generalizations are possible about their characteristics; (3) what are the major practical considerations; and (4) what is the present situation and what can be said about the outlook for the future

  4. Vented nuclear fuel element

    International Nuclear Information System (INIS)

    Oguma, M.; Hirose, Y.

    1976-01-01

    A description is given of a vented nuclear fuel element having a plenum for accumulation of fission product gases and plug means for delaying the release of the fission product gases from the plenum, the plug means comprising a first porous body wettable with a liquid metal and a second porous body non-wettable with the liquid metal, the first porous body being impregnated with the liquid metal and in contact with the liquid metal

  5. Nuclear reactor fuel element splitter

    International Nuclear Information System (INIS)

    Yeo, D.

    1976-01-01

    A method and apparatus are disclosed for removing nuclear fuel from a clad fuel element. The fuel element is power driven past laser beams which simultaneously cut the cladding lengthwise into at least two longitudinal pieces. The axially cut lengths of cladding are then separated, causing the nuclear fuel contained therein to drop into a receptacle for later disposition. The cut lengths of cladding comprise nuclear waste which is disposed of in a suitable manner. 6 claims, 10 drawing figures

  6. Characteristics of potential repository wastes: Volume 4, Appendix 4A, Nuclear reactors at educational institutions of the United States; Appendix 4B, Data sheets for nuclear reactors at educational institutions; Appendix 4C, Supplemental data for Fort St. Vrain spent fuel; Appendix 4D, Supplemental data for Peach Bottom 1 spent fuel; Appendix 4E, Supplemental data for Fast Flux Test Facility

    International Nuclear Information System (INIS)

    1992-07-01

    Volume 4 contains the following appendices: nuclear reactors at educational institutions in the United States; data sheets for nuclear reactors at educational institutions in the United States(operational reactors and shut-down reactors); supplemental data for Fort St. Vrain spent fuel; supplemental data for Peach Bottom 1 spent fuel; and supplemental data for Fast Flux Test Facility

  7. Spent fuel repositories and environmental impact assessment; the legal situation i Finland

    International Nuclear Information System (INIS)

    Manninen, J.

    1995-01-01

    The Finnish Act on Environmental Impact Assessment (468/94) builds on the EU Directive 85/337 on the assessment of the effects of certain public and private projects on the environment. The Act is supplemented by the Decree on Environmental Impact Assessment (792/88). The EIA Act is applicable to all nuclear facilities, spent fuel repositories included. In practice the new Act does not introduce any drastic changes to the legal situation, as far as nuclear facilities are concerned. The Finnish Nuclear Energy Act (990/87), which entered into force 1988, already contains most of the basic elements of the environmental impact assessment. In the article, the different steps in the Finnish EIA procedure is described

  8. Nuclear fuel handling apparatus

    International Nuclear Information System (INIS)

    Andrea, C.; Dupen, C.F.G.; Noyes, R.C.

    1977-01-01

    A fuel handling machine for a liquid metal cooled nuclear reactor in which a retractable handling tube and gripper are lowered into the reactor to withdraw a spent fuel assembly into the handling tube. The handling tube containing the fuel assembly immersed in liquid sodium is then withdrawn completely from the reactor into the outer barrel of the handling machine. The machine is then used to transport the spent fuel assembly directly to a remotely located decay tank. The fuel handling machine includes a decay heat removal system which continuously removes heat from the interior of the handling tube and which is capable of operating at its full cooling capacity at all times. The handling tube is supported in the machine from an articulated joint which enables it to readily align itself with the correct position in the core. An emergency sodium supply is carried directly by the machine to provide make up in the event of a loss of sodium from the handling tube during transport to the decay tank. 5 claims, 32 drawing figures

  9. Advanced nuclear fuel cycles and radioactive waste management

    International Nuclear Information System (INIS)

    2006-01-01

    This study analyses a range of advanced nuclear fuel cycle options from the perspective of their effect on radioactive waste management policies. It presents various fuel cycle options which illustrate differences between alternative technologies, but does not purport to cover all foreseeable future fuel cycles. The analysis extends the work carried out in previous studies, assesses the fuel cycles as a whole, including all radioactive waste generated at each step of the cycles, and covers high-level waste repository performance for the different fuel cycles considered. The estimates of quantities and types of waste arising from advanced fuel cycles are based on best available data and experts' judgement. The effects of various advanced fuel cycles on the management of radioactive waste are assessed relative to current technologies and options, using tools such as repository performance analysis and cost studies. (author)

  10. South Korea's nuclear fuel industry

    International Nuclear Information System (INIS)

    Clark, R.G.

    1990-01-01

    March 1990 marked a major milestone for South Korea's nuclear power program, as the country became self-sufficient in nuclear fuel fabrication. The reconversion line (UF 6 to UO 2 ) came into full operation at the Korea Nuclear Fuel Company's fabrication plant, as the last step in South Korea's program, initiated in the mid-1970s, to localize fuel fabrication. Thus, South Korea now has the capability to produce both CANDU and pressurized water reactor (PWR) fuel assemblies. This article covers the nuclear fuel industry in South Korea-how it is structures, its current capabilities, and its outlook for the future

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

    International Nuclear Information System (INIS)

    Smith, A.I.

    1991-01-01

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

  12. Nuclear fuel rod loading apparatus

    International Nuclear Information System (INIS)

    King, H.B.

    1981-01-01

    A nuclear fuel loading apparatus, incorporating a microprocessor control unit, is described which automatically loads nuclear fuel pellets into dual fuel rods with a minimum of manual involvement and in a manner and sequence to ensure quality control and accuracy. (U.K.)

  13. Depleted uranium oxides as spent-nuclear-fuel waste-package invert and backfill materials

    International Nuclear Information System (INIS)

    Forsberg, C.W.; Haire, M.J.

    1997-01-01

    A new technology has been proposed in which depleted uranium, in the form of oxides or silicates, is placed around the outside of the spent nuclear fuel waste packages in the geological repository. This concept may (1) reduce the potential for repository nuclear criticality events and (2) reduce long-term release of radionuclides from the repository. As a new concept, there are significant uncertainties

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2017-11-01

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

  15. Dispute resolution in the nuclear waste repository program

    International Nuclear Information System (INIS)

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

    1988-01-01

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

  16. Normal evolution of a spent fuel repository at the candidate sites in Finland

    International Nuclear Information System (INIS)

    Grawford, M.B.; Wilmot, R.D.

    1998-12-01

    The Finnish disposal concept for spent nuclear fuel envisages burial of the fuel in a repository excavated at a depth of around 500 m in crystalline bedrock. Since 1983, a programme has been underway in Finland to select a potential site for such a repository. The programme is now in the final stages of selecting one site for further detailed characterisation from a list of four candidate sites at Kivetty, Romuvaara, Olkiluoto, and Haestholmen. Each stage of the site selection process has been supported by a major performance assessment (PA) exercise. The aim of this report is to describe the normal evolution of a repository system at the four candidate Finnish sites as input to development of the next PA, known as TILA-99. The report summarises the disposal concept and the present-day characteristics of each candidate site, and considers the most likely future changes in both the natural environment and the engineered components of the disposal system. The description concentrates on the key features, events and processes (FEPs) controlling behaviour and evolution of the disposal system. It is assumed that all the canisters are intact following emplacement and repository closure. FEPs that occur but which do not significantly affect system behaviour and evolution are only briefly described. FEPs with a low probability of occurrence are mentioned as appropriate. The report provides a map to the key Finnish reports and other work that underlies and supports the description of normal evolution. Differences between the four candidate sites in terms of their expected normal evolution are summarised. None of the differences are sufficient to prevent each site from behaving as a 'normal' site, the evolution of which is summarised over time in the final section of the report. (author)

  17. Normal evolution of a spent fuel repository at the candidate sites in Finland

    Energy Technology Data Exchange (ETDEWEB)

    Grawford, M.B.; Wilmot, R.D. [Galson Sciences Limited, Rutland (United Kingdom)

    1998-12-01

    The Finnish disposal concept for spent nuclear fuel envisages burial of the fuel in a repository excavated at a depth of around 500 m in crystalline bedrock. Since 1983, a programme has been underway in Finland to select a potential site for such a repository. The programme is now in the final stages of selecting one site for further detailed characterisation from a list of four candidate sites at Kivetty, Romuvaara, Olkiluoto, and Haestholmen. Each stage of the site selection process has been supported by a major performance assessment (PA) exercise. The aim of this report is to describe the normal evolution of a repository system at the four candidate Finnish sites as input to development of the next PA, known as TILA-99. The report summarises the disposal concept and the present-day characteristics of each candidate site, and considers the most likely future changes in both the natural environment and the engineered components of the disposal system. The description concentrates on the key features, events and processes (FEPs) controlling behaviour and evolution of the disposal system. It is assumed that all the canisters are intact following emplacement and repository closure. FEPs that occur but which do not significantly affect system behaviour and evolution are only briefly described. FEPs with a low probability of occurrence are mentioned as appropriate. The report provides a map to the key Finnish reports and other work that underlies and supports the description of normal evolution. Differences between the four candidate sites in terms of their expected normal evolution are summarised. None of the differences are sufficient to prevent each site from behaving as a `normal` site, the evolution of which is summarised over time in the final section of the report. (author) 155 refs.

  18. Future trends in nuclear fuels

    International Nuclear Information System (INIS)

    Guitierrez, J.E.

    2006-01-01

    This series of transparencies presents: the fuel management cycle and key areas (security of supplies, strategies and core management, reliability, spent fuel management), the world nuclear generating capacity, concentrate capacity, enrichment capacity, and manufacturing capacity forecasts, the fuel cycle strategies and core management (longer cycles, higher burnups, power up-rates, higher enrichments), the Spanish nuclear generation cost, the fuel reliability (no defects, robust designs, operational margins, integrated fuel and core design), spent fuel storage (design and safety criteria, fuel performance and integrity). (J.S.)

  19. Nuclear fuel element

    International Nuclear Information System (INIS)

    Iwano, Yoshihiko.

    1993-01-01

    Microfine cracks having a depth of less than 10% of a pipe thickness are disposed radially from a central axis each at an interval of less than 100 micron over the entire inner circumferential surface of a zirconium alloy fuel cladding tube. For manufacturing such a nuclear fuel element, the inside of the cladding tube is at first filled with an electrolyte solution of potassium chloride. Then, electrolysis is conducted using the cladding tube as an anode and the electrolyte solution as a cathode, and the inner surface of the cladding tube with a zirconium dioxide layer having a predetermined thickness. Subsequently, the cladding tube is laid on a smooth steel plate and lightly compressed by other smooth steel plate to form microfine cracks in the zirconium dioxide layer on the inner surface of the cladding tube. Such a compressing operation is continuously applied to the cladding tube while rotating the cladding tube. This can inhibit progress of cracks on the inner surface of the cladding tube, thereby enabling to prevent failure of the cladding tube even if a pellet/cladding tube mechanical interaction is applied. Accordingly, reliability of the nuclear fuel elements is improved. (I.N.)

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

    International Nuclear Information System (INIS)

    Fattah, A.

    2002-01-01

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

  1. Impact of Nuclear Energy Futures on Advanced Fuel Cycle Options

    International Nuclear Information System (INIS)

    Brent W. Dixon; Steven J. Piet

    2004-01-01

    The Nuclear Waste Policy Act requires the Secretary of Energy to inform Congress before 2010 on the need for a second geologic repository for spent nuclear fuel. By that time, the spent fuel discharged from current commercial reactors will exceed the statutory limit of the first repository (63,000 MTiHM commercial, 7,000 MT non-commercial). There are several approaches to eliminate the need for another repository in this century. This paper presents a high-level analysis of these spent fuel management options in the context of a full range of possible nuclear energy futures. The analysis indicates the best option to implement varies depending on the nuclear energy future selected. The first step in understanding the need for different spent fuel management approaches is to understand the size of potential spent fuel inventories. A full range of potential futures for domestic commercial nuclear energy is considered. These energy futures are as follows: 1. Existing License Completion - Based on existing spent fuel inventories plus extrapolation of future plant-by-plant discharges until the end of each operating license, including known license extensions. 2. Extended License Completion - Based on existing spent fuel inventories plus a plant-by-plant extrapolation of future discharges assuming on all operating plants having one 20-year extension. 3. Continuing Level Energy Generation - Based on extension of the current ∼100 GWe installed commercial base and average spent fuel discharge of 2100 MT/yr through the year 2100. 4. Continuing Market Share Generation - Based on a 1.8% compounded growth of the electricity market through the year 2100, matched by growing nuclear capacity and associated spent fuel discharge. 5. Growing Market Share Generation - Extension of current nuclear capacity and associated spent fuel discharge through 2100 with 3.2% growth representing 1.5% market growth (all energy, not just electricity) and 1.7% share growth. Share growth results in

  2. Nuclear fuel element

    International Nuclear Information System (INIS)

    Armijo, J.S.

    1977-01-01

    A nuclear fuel element for use in the core of a nuclear reactor is disclosed which has a composite cladding having a substrate, a metal barrier metallurgically bonded to the inside surface of the substrate and an inner layer metallurgically bonded to the inside surface of the metal barrier. In this composite cladding, the inner layer and the metal barrier shield the substrate from any impurities or fission products from the nuclear fuel material held within the composite cladding. The metal barrier forms about 1 to about 4 percent of the thickness of the cladding and is comprised of a metal selected from the group consisting of niobium, aluminum, copper, nickel, stainless steel, and iron. The inner layer and then the metal barrier serve as reaction sites for volatile impurities and fission products and protect the substrate from contact and reaction with such impurities and fission products. The substrate and the inner layer of the composite cladding are selected from conventional cladding materials and preferably are a zirconium alloy. Also in a preferred embodiment the substrate and the inner layer are comprised of the same material, preferably a zirconium alloy. 19 claims, 2 figures

  3. Improved nuclear fuel element

    International Nuclear Information System (INIS)

    1980-01-01

    The invention is of a nuclear fuel element which comprises a central core of a body of nuclear fuel material selected from the group consisting of compounds of uranium, plutonium, thorium and mixtures thereof, and an elongated composite cladding container comprising a zirconium alloy tube containing constituents other than zirconium in an amount greater than about 5000 parts per million by weight and an undeformed metal barrier of moderate purity zirconium bonded to the inside surface of the alloy tube. The container encloses the core so as to leave a gap between the container and the core during use in a nuclear reactor. The metal barrier is of moderate purity zirconium with an impurity level on a weight basis of at least 1000ppm and less than 5000ppm. Impurity levels of specific elements are given. Variations of the invention are also specified. The composite cladding reduces chemical interaction, minimizes localized stress and strain corrosion and reduces the likelihood of a splitting failure in the zirconium alloy tube. Other benefits are claimed. (U.K.)

  4. Fuel cycle covariance of plutonium and americium separations to repository capacity using information theoretic measures

    International Nuclear Information System (INIS)

    Scopatz, Anthony; Schneider, Erich; Li, Jun; Yim, Man-Sung

    2011-01-01

    A light water reactor, fast reactor symbiotic fuel cycle scenario was modeled and parameterized based on thirty independent inputs. Simultaneously and stochastically choosing different values for each of these inputs and performing the associated fuel cycle mass-balance calculation, the fuel cycle itself underwent Monte Carlo simulation. A novel information theoretic metric is postulated as a measure of system-wide covariance. This metric is the coefficient of variation of the set of uncertainty coefficients generated from 2D slices of a 3D contingency table. It is then applied to the fuel cycle, taking fast reactor used fuel plutonium and americium separations as independent variables and the capacity of a fully-loaded tuff repository as the response. This set of parameters is known from prior studies to have a strong covariance. When measured with all 435 other input parameters possible, the fast reactor plutonium and americium separations pair was found to be ranked the second most covariant. This verifies that the coefficient of variation metric captures the desired sensitivity of sensitivity effects in the nuclear fuel cycle. (author)

  5. Quality management of nuclear fuel

    International Nuclear Information System (INIS)

    2006-01-01

    The Guide presents the quality management requirements to be complied with in the procurement, design, manufacture, transport, receipt, storage, handling and operation of nuclear fuel. The Guide also applies to control rods and shield elements to be placed in the reactor. The Guide is mainly aimed for the licensee responsible for the procurement and operation of fuel, for the fuel designer and manufacturer and for other organisations, whose activities affect fuel quality and the safety of fuel transport, storage and operation. General requirements for nuclear fuel are presented in Section 114 of the Finnish Nuclear Energy Decree and in Section 15 of the Government Decision (395/1991). Regulatory control of the safety of fuel is described in Guides YVL6.1, YVL6.2 and YVL6.3. An overview of the regulatory control of nuclear power plants carried out by STUK (Radiation and Nuclear Safety Authority, Finland) is clarified in Guide YVL1.1

  6. 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

  7. Nuclear power and the nuclear fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    1976-07-01

    The IAEA is organizing a major conference on nuclear power and the nuclear fuel cycle, which is to be held from 2 to 13 May 1977 in Salzburg, Austria. The programme for the conference was published in the preceding issue of the IAEA Bulletin (Vol.18, No. 3/4). Topics to be covered at the conference include: world energy supply and demand, supply of nuclear fuel and fuel cycle services, radioactivity management (including transport), nuclear safety, public acceptance of nuclear power, safeguarding of nuclear materials, and nuclear power prospects in developing countries. The articles in the section that follows are intended to serve as an introduction to the topics to be discussed at the Salzburg Conference. They deal with the demand for uranium and nuclear fuel cycle services, uranium supplies, a computer simulation of regional fuel cycle centres, nuclear safety codes, management of radioactive wastes, and a pioneering research project on factors that determine public attitudes toward nuclear power. It is planned to present additional background articles, including a review of the world nuclear fuel reprocessing situation and developments in the uranium enrichment industry, in future issues of the Bulletin. (author)

  8. Nuclear fuel supplies

    International Nuclear Information System (INIS)

    1960-01-01

    When the International Atomic Energy Agency was set up nearly three years ago, it was widely believed that it would soon become a world bank or broker for the supply of nuclear fuel. Some observers now seem to feel that this promise has been rather slow to come to fruition. A little closer analysis would, however, show that the promise can be fulfilled only in a certain objective context, and to the extent that this context exists, the development of the Agency's role has been commensurate with the actual needs of the situation

  9. Nuclear fuel waste disposal

    International Nuclear Information System (INIS)

    Allan, C.J.

    1993-01-01

    The Canadian concept for nuclear fuel waste disposal is based on disposing of the waste in a vault excavated 500-1000 m deep in intrusive igneous rock of the Canadian Shield. The author believes that, if the concept is accepted following review by a federal environmental assessment panel (probably in 1995), then it is important that implementation should begin without delay. His reasons are listed under the following headings: Environmental leadership and reducing the burden on future generations; Fostering public confidence in nuclear energy; Forestalling inaction by default; Preserving the knowledge base. Although disposal of reprocessing waste is a possible future alternative option, it will still almost certainly include a requirement for geologic disposal

  10. Transport and storage of spent nuclear fuel

    International Nuclear Information System (INIS)

    Lung, M.; Lenail, B.

    1987-01-01

    From a safety standpoint, spent fuel is clearly not ideal for permanent disposal and reprocessing is the best method of preparing wastes for long-term storage in a repository. Furthermore, the future may demonstrate that some fission products recovered in reprocessing have economic applications. Many countries have in fact reached the point at which the recycling of plutonium and uranium from spent fuel is economical in LWR's. Even in countries where this is not yet evident, (i.e., the United States), the French example shows that the day will come when spent fuel will be retrieved for reprocessing and recycle. It is highly questionable whether spent fuel will ever be considered and treated as waste in the same sense as fission products and processed as such, i.e., packaged in a waste form for permanent disposal. Even when recycled fuel material can no longer be reused in LWR's because of poor reactivity, it will be usable in FBR's. Based on the considerable experience gained by SGN and Cogema, this paper has provided practical discussion and illustrations of spent fuel transport and storage of a very important step in the nuclear fuel management process. The best of spent fuel storage depends on technical, economic and policy considerations. Each design has a role to play and we hope that the above discussion will help clarify certain issues

  11. Advantages of co-located spent fuel reprocessing, repository and underground reactor facilities

    International Nuclear Information System (INIS)

    Mahar, James M.; Kunze, Jay F.; Wes Myers, Carl; Loveland, Ryan

    2007-01-01

    The purpose of this work is to extend the discussion of potential advantages of the underground nuclear park (UNP) concept by making specific concept design and cost estimate comparisons for both present Generation III types of reactors and for some of the modular Gen IV or the GNEP modular concept. For the present Gen III types, we propose co-locating reprocessing and (re)fabrication facilities along with disposal facilities in the underground park. The goal is to determine the site costs and facility construction costs of such a complex which incorporates the advantages of a closed fuel cycle, nuclear waste repository, and ultimate decommissioning activities all within the UNP. Modular power generation units are also well-suited for placement underground and have the added advantage of construction using current and future tunnel boring machine technology. (authors)

  12. The final disposal facility of spent nuclear fuel

    International Nuclear Information System (INIS)

    Prvakova, S.; Necas, V.

    2001-01-01

    Today the most serious problem in the area of nuclear power engineering is the management of spent nuclear fuel. Due to its very high radioactivity the nuclear waste must be isolated from the environment. The perspective solution of nuclear fuel cycle is the final disposal into geological formations. Today there is no disposal facility all over the world. There are only underground research laboratories in the well developed countries like the USA, France, Japan, Germany, Sweden, Switzerland and Belgium. From the economical point of view the most suitable appears to build a few international repositories. According to the political and social aspect each of the country prepare his own project of the deep repository. The status of those programmes in different countries is described. The development of methods for the long-term management of radioactive waste is necessity in all countries that have had nuclear programmes. (authors)

  13. 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

  14. 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

  15. Repository emplacement costs for Al-clad high enriched uranium spent fuel

    International Nuclear Information System (INIS)

    McDonell, W.R.; Parks, P.B.

    1994-01-01

    A range of strategies for treatment and packaging of Al-clad high-enriched uranium (HEU) spent fuels to prevent or delay the onset of criticality in a geologic repository was evaluated in terms of the number of canisters produced and associated repository costs incurred. The results indicated that strategies in which neutron poisons were added to consolidated forms of the U-Al alloy fuel generally produced the lowest number of canisters and associated repository costs. Chemical processing whereby the HEU was removed from the waste form was also a low cost option. The repository costs generally increased for isotopic dilution strategies, because of the substantial depleted uranium added. Chemical dissolution strategies without HEU removal were also penalized because of the inert constituents in the final waste glass form. Avoiding repository criticality by limiting the fissile mass content of each canister incurred the highest repository costs

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

    International Nuclear Information System (INIS)

    Brunnengraeber, Achim

    2016-01-01

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

  17. Regulation at nuclear fuel cycle

    International Nuclear Information System (INIS)

    2002-01-01

    This bulletin contains information about activities of the Nuclear Regulatory Authority of the Slovak Republic (UJD). In this leaflet the role of the UJD in regulation at nuclear fuel cycle is presented. The Nuclear Fuel Cycle (NFC) is a complex of activities linked with production of nuclear fuel for nuclear reactors as a source of energy used for production of electricity and heat, and of activities linked with spent nuclear fuel handling. Activities linked with nuclear fuel (NF) production, known as the Front-End of Nuclear Fuel Cycle, include (production of nuclear fuel from uranium as the most frequently used element). After discharging spent nuclear fuel (SNF) from nuclear reactor the activities follow linked with its storage, reprocessing and disposal known as the Back-End of Nuclear Fuel Cycle. Individual activity, which penetrates throughout the NFC, is transport of nuclear materials various forms during NF production and transport of NF and SNF. Nuclear reactors are installed in the Slovak Republic only in commercial nuclear power plants and the NFC is of the open type is imported from abroad and SNF is long-term supposed without reprocessing. The main mission of the area of NFC is supervision over: - assurance of nuclear safety throughout all NFC activities; - observance of provisions of the Treaty on Non-Proliferation of Nuclear Weapons during nuclear material handling; with an aim to prevent leakage of radioactive substances into environment (including deliberated danage of NFC sensitive facilities and misuse of nuclear materials to production of nuclear weapons. The UJD carries out this mission through: - assessment of safety documentation submitted by operators of nuclear installations at which nuclear material, NF and SNF is handled; - inspections concentrated on assurance of compliance of real conditions in NFC, i.e. storage and transport of NF and SNF; storage, transport and disposal of wastes from processing of SNF; with assumptions of the safety

  18. 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

  19. Nuclear power generation and nuclear fuel

    International Nuclear Information System (INIS)

    Okajima, Yasujiro

    1985-01-01

    As of June 30, 1984, in 25 countries, 311 nuclear power plants of about 209 million kW were in operation. In Japan, 27 plants of about 19 million kW were in operation, and Japan ranks fourth in the world. The present state of nuclear power generation and nuclear fuel cycle is explained. The total uranium resources in the free world which can be mined at the cost below $130/kgU are about 3.67 million t, and it was estimated that the demand up to about 2015 would be able to be met. But it is considered also that the demand and supply of uranium in the world may become tight at the end of 1980s. The supply of uranium to Japan is ensured up to about 1995, and the yearly supply of 3000 st U 3 O 8 is expected in the latter half of 1990s. The refining, conversion and enrichment of uranium are described. In Japan, a pilot enrichment plant consisting of 7000 centrifuges has the capacity of about 50 t SWU/year. UO 2 fuel assemblies for LWRs, the working of Zircaloy, the fabrication of fuel assemblies, the quality assurance of nuclear fuel, the behavior of UO 2 fuel, the grading-up of LWRs and nuclear fuel, and the nuclear fuel business in Japan are reported. The reprocessing of spent fuel and plutonium fuel are described. (Kako, I.)

  20. Factors affecting actinide solubility in a repository for spent fuel, 1

    International Nuclear Information System (INIS)

    Snellman, Margit

    1986-07-01

    The main tasks in the study were to get information on the chemical conditions in a repository for spent fuel and information on factors affecting releases of actinides from spent fuel and solubility of actinides in a repository for spent fuel. The work in this field started at the Reactor Laboratory of the Technical Research Centre of Finland (VTT) in 1982. This is a report on the effects on the main parameters, Eh, pH, carbonate, organic compounds, colloids, microbes and radiation on the actinide solubility in the nearfield of the repository. Another task has been to identify available models and reported experience from actinide solubility calculations with different codes. 167 refs

  1. Financing the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Stephany, M.

    1975-01-01

    While conventional power stations usually have fossil fuel reserves for only a few weeks, nuclear power stations, because of the relatively long time required for uranium processing from ore extraction to the delivery of the fuel elements and their prolonged in-pile time, require fuel reserves for a period of several years. Although the specific fuel costs of nuclear power stations are much lower than those of conventional power stations, this results in consistently higher financial requirements. But the problems involved in financing the nuclear fuel do not only include the aspect of financing the requirements of reactor operators, but also of financing the facilities of the nuclear fuel cycle. As far as the fuel supply is concerned, the true financial requirements greatly exceed the mere purchasing costs because the costs of financing are rather high as a consequence of the long lead times. (orig./UA) [de

  2. IAEA activities on nuclear fuel

    International Nuclear Information System (INIS)

    Basak, U.

    2011-01-01

    In this paper a brief description and the main objectives of IAEA Programme B on Nuclear fuel cycle are given. The following Coordinated Research Projects: 1) FUel performance at high burn-up and in ageing plant by management and optimisation of WAter Chemistry Technologies (FUWAC ); 2) Near Term and Promising Long Term Options for Deployment of Thorium Based Nuclear Energy; 3) Fuel Modelling (FUMEX-III) are shortly described. The data collected by the IAEA Expert Group of Fuel Failures in Water Cooled Reactors including information about fuel failure cause for PWR (1994-2006) and failure mechanisms for BWR fuel (1994-2006) are shown. The just published Fuel Failure Handbook as well as preparation of a Monograph on Zirconium including an overview of Zirconium for nuclear applications are presented. The current projects in Sub-programme B2 - Power Reactor Fuel Engineering are also listed

  3. Nuclear fuel pellet charging device

    International Nuclear Information System (INIS)

    Komuro, Kojiro.

    1990-01-01

    The present invention concerns a nuclear fuel pellet loading device, in which nuclear fuel pellets are successively charged from an open end of a fuel can while rotating the can. That is, a fuel can sealed at one end with an end plug and opened at the other end is rotated around its pipe axis as the center on a rotationally diriving table. During rotation of the fuel can, nuclear fuel pellets are successively charged by means of a feed rod of a feeding device to the inside of the fuel can. The fuel can is rotated while being supported horizontally and the fuel pellets are charged from the open end thereof. Alternatively, the fuel can is rotated while being supported obliquely and the fuel pellets are charged gravitationally into the fuel can. In this way, the damages to the barrier of the fuel can can be reduce. Further, since the fuel pellets can be charged gravitationally by rotating the fuel can while being supported obliquely, the damages to the barrier can be reduced remarkably. (I.S.)

  4. Nuclear power fuel cycle

    International Nuclear Information System (INIS)

    Havelka, S.; Jakesova, L.

    1982-01-01

    Economic problems are discussed of the fuel cycle (cost of the individual parts of the fuel cycle and the share of the fuel cycle in the price of 1 kWh), the technological problems of the fuel cycle (uranium ore mining and processing, uranium isotope enrichment, the manufacture of fuel elements, the building of long-term storage sites for spent fuel, spent fuel reprocessing, liquid and gaseous waste processing), and the ecologic aspects of the fuel cycle. (H.S.)

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

    Energy Technology Data Exchange (ETDEWEB)

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

    2004-03-01

    monitoring are to: obtain knowledge of undisturbed conditions in nature and their seasonal variations (baseline) in order to identify and evaluate the impact of activities related to the deep repository during different phases, obtain a better understanding of the function of the deep repository system to support the safety account and to test models and assumptions, monitor the environmental impact of the deep repository, provide evidence that the working environment is safe with regard to radiological and non-radiological effects, show that requirements on radioactive waste verification (safeguards) are fulfilled. The monitoring is concerned with bedrock conditions before and during construction and operation of the facilities, active design to engineer the underground facilities based on monitoring results during construction, the safe and environmental construction and operation of facilities. Experience exists from monitoring of the barrier function at SFR, the final repository for low - and intermediate level waste and at the Aespoe Hard Rock Laboratory and monitoring for safeguard at CLAB, the interim storage for spent nuclear fuel. The know-how on monitoring relates to all aspects from design, installation, operation and maintenance to decommissioning of systems. This report provides an overview of the features, processes and parameters that are collected during the site investigations to establish the Primary Baseline conditions for monitoring prior to the construction of the repository. It is also proposed that the monitoring programme should at least entail the following elements: objectives for the monitoring programme, scope for the monitoring (criteria for selection of issues to be monitored, identification of the properties, processes, phenomena and observable quantities to be monitored), identification on what methods to be used, operation of the monitoring system (identification of the duration and frequency of monitoring, including criteria for when

  6. Nuclear power and the nuclear fuel cycle

    International Nuclear Information System (INIS)

    Scurr, I.F.; Silver, J.M.

    1990-01-01

    Australian Nuclear Science and Technology Organization maintains an ongoing assessment of the world's nuclear technology developments, as a core activity of its Strategic Plan. This publication reviews the current status of the nuclear power and the nuclear fuel cycle in Australia and around the world. Main issues discussed include: performances and economics of various types of nuclear reactors, uranium resources and requirements, fuel fabrication and technology, radioactive waste management. A brief account of the large international effort to demonstrate the feasibility of fusion power is also given. 11 tabs., ills

  7. Corrosion of titanium and titanium alloys in spent fuel repository conditions - literature review

    International Nuclear Information System (INIS)

    Aho-Mantila, I.; Haenninen, H.; Aaltonen, P.; Taehtinen, S.

    1985-03-01

    The spent nuclear fuel is planned to be disposed in Finnish bedrock. The canister of spent fuel in waste repository is one barrier to the release of radionuclides. It is possible to choose a canister material with a known, measurable corrosion rate and to make it with thickness allowing corrosion to occur. The other possibility is to use a material which is nearly immune to general corrosion. In this second category there are titanium and titanium alloys which exhibit a very high degree of resistance to general corrosion. In this literature study the corrosion properties of unalloyed titanium, titanium alloyed with palladium and titanium alloyed with molybdenum and nickel are reviewed. The two titanium alloys own in addition to the excellent general corrosion properties outstanding properties against localized corrosion like pitting or crevice corrosion. Stress corrosion cracking and corrosion fatique of titanium seem not to be a problem in the repository conditions, but the possibilities of delayed cracking caused by hydrogen should be carefully appreciated. (author)

  8. A preliminary analysis of the risk of transporting nuclear waste to potential candidate commercial repository sites

    International Nuclear Information System (INIS)

    Madsen, M.M.

    1984-01-01

    In accordance with the provisions of the Nuclear Waste Policy Act of 1982, environmental assessments for potential candidate sites are required to provide a basis for selection of the first site for disposal of commercial radioactive waste in deep geologic repositories. A preliminary analysis of the impacts of transportation for each of the five potential sites will be described. Transportation was assumed to be entirely by truck or entirely by rail in order to obtain bounding impacts. This paper presents both radiological and nonradiological risks for the once-through fuel cycle

  9. 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)

  10. Impact of actinide recycle on nuclear fuel cycle health risks

    International Nuclear Information System (INIS)

    Michaels, G.E.

    1992-06-01

    The purpose of this background paper is to summarize what is presently known about potential impacts on the impacts on the health risk of the nuclear fuel cycle form deployment of the Advanced Liquid Metal Reactor (ALMR) 1 and Integral Fast Reactor (IF) 2 technology as an actinide burning system. In a companion paper the impact on waste repository risk is addressed in some detail. Therefore, this paper focuses on the remainder of the fuel cycle

  11. Radioactive Waste Generation in Pyro-SFR Nuclear Fuel Cycle

    International Nuclear Information System (INIS)

    Gao, Fanxing; Park, Byung Heung; Ko, Won Il

    2011-01-01

    Which nuclear fuel cycle option to deploy is of great importance in the sustainability of nuclear power. SFR fuel cycle employing pyroprocessing (named as Pyro- SFR Cycle) is one promising fuel cycle option in the near future. Radioactive waste generation is a key criterion in nuclear fuel cycle system analysis, which considerably affects the future development of nuclear power. High population with small territory is one special characteristic of ROK, which makes the waste management pretty important. In this study, particularly the amount of waste generation with regard to the promising advanced fuel cycle option was evaluated, because the difficulty of deploying an underground repository for HLW disposal requires a longer time especially in ROK

  12. 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

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

    International Nuclear Information System (INIS)

    Hammarstroem, Monika

    2000-01-01

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

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

    International Nuclear Information System (INIS)

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

    1979-01-01

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

  15. Romanian nuclear fuel cycle development

    International Nuclear Information System (INIS)

    Rapeanu, S.N.; Comsa, Olivia

    1998-01-01

    Romanian decision to introduce nuclear power was based on the evaluation of electricity demand and supply as well as a domestic resources assessment. The option was the introduction of CANDU-PHWR through a license agreement with AECL Canada. The major factors in this choice have been the need of diversifying the energy resources, the improvement the national industry and the independence of foreign suppliers. Romanian Nuclear Power Program envisaged a large national participation in Cernavoda NPP completion, in the development of nuclear fuel cycle facilities and horizontal industry, in R and D and human resources. As consequence, important support was being given to development of industries involved in Nuclear Fuel Cycle and manufacturing of equipment and nuclear materials based on technology transfer, implementation of advanced design execution standards, QA procedures and current nuclear safety requirements at international level. Unit 1 of the first Romanian nuclear power plant, Cernavoda NPP with a final profile 5x700 Mw e, is now in operation and its production represents 10% of all national electricity production. There were also developed all stages of FRONT END of Nuclear Fuel Cycle as well as programs for spent fuel and waste management. Industrial facilities for uranian production, U 3 O 8 concentrate, UO 2 powder and CANDU fuel bundles, as well as heavy water plant, supply the required fuel and heavy water for Cernavoda NPP. The paper presents the Romanian activities in Nuclear Fuel Cycle and waste management fields. (authors)

  16. Dealing with the current permissibility application for constructing a spent fuel DGR in Sweden. SKB's license applications for a spent fuel repository

    International Nuclear Information System (INIS)

    Olsson, Olle

    2014-01-01

    The nuclear power utilities in Sweden were in 1976 obliged to demonstrate a safe method for final disposal of spent fuel in order to start operation of new reactors. This initiated a comprehensive research, development and demonstration programme and the development of the KBS-method for final disposal. A new Nuclear Activities Act in 1984 gave the reactor owners full technical and financial responsibility for the waste. They gave in turn SKB the responsibility for all nuclear waste management. Reprocessing was no longer required and direct disposal of the spent fuel has, since then, been the main alternative. Alternative methods for final disposal have been evaluated and compared to the KBS-3-method but it has remained the preferred alternative. A comprehensive research, development and demonstration programme to strengthen the scientific basis and to refine the KBS-3-method has been operated by SKB since then. The site selection process for the final repository for spent nuclear fuel was initiated in 1992. The work included general siting studies at the national and the municipal level and in 2002, SKB initiated site investigations for siting of a final repository on two sites: the Simpevarp and Laxemar areas and the Forsmark area. At the same time, the work on preparing license applications to construct and operate an encapsulation plant and a final repository for spent fuel was started. In June 2009, SKB announced Forsmark as the selected site for the final repository. This paper reviews the applicable legislation and describes the license application, the licensing review and the preparations for implementation

  17. Reactor Structure Materials: Nuclear Fuel

    International Nuclear Information System (INIS)

    Sannen, L.; Verwerft, M.

    2000-01-01

    Progress and achievements in 1999 in SCK-CEN's programme on applied and fundamental nuclear fuel research in 1999 are reported. Particular emphasis is on thermochemical fuel research, the modelling of fission gas release in LWR fuel as well as on integral experiments

  18. Burnable absorber coated nuclear fuel

    International Nuclear Information System (INIS)

    Chubb, W.; Radford, K.C.; Parks, B.H.

    1984-01-01

    A nuclear fuel body which is at least partially covered by a burnable neutron absorber layer is provided with a hydrophobic overcoat generally covering the burnable absorber layer and bonded directly to it. In a method for providing a UO 2 fuel pellet with a zirconium diboride burnable poison layer, the fuel body is provided with an intermediate niobium layer. (author)

  19. Comparison of potential radiological consequences from a spent-fuel repository and natural uranium deposits

    International Nuclear Information System (INIS)

    Wick, O.J.; Cloninger, M.O.

    1980-09-01

    A general criterion has been suggested for deep geological repositories containing spent fuel - the repositories should impose no greater radiological risk than due to naturally occurring uranium deposits. The following analysis investigates the rationale of that suggestion and determines whether current expectations of spent-fuel repository performance are consistent with such a criterion. In this study, reference spent-fuel repositories were compared to natural uranium-ore deposits. Comparisons were based on intrinsic characteristics, such as radionuclide inventory, depth, proximity to aquifers, and regional distribution, and actual and potential radiological consequences that are now occurring from some ore deposits and that may eventually occur from repositories and other ore deposits. The comparison results show that the repositories are quite comparable to the natural ore deposits and, in some cases, present less radiological hazard than their natural counterparts. On the basis of the first comparison, placing spent fuel in a deep geologic repository apparently reduces the hazard from natural radioactive materials occurring in the earth's crust by locating the waste in impermeable strata without access to oxidizing conditions. On the basis of the second comparison, a repository constructed within reasonable constraints presents no greater hazard than a large ore deposit. It is recommended that if the naturally radioactive environment is to be used as a basis for a criterion regarding repositories, then this criterion should be carefully constructed. The criterion should be based on the radiological quality of the waters in the immediate region of a specific repository, and it should be in terms of an acceptable potential increase in the radiological content of those waters due to the existence of the repository

  20. The fuel of nuclear reactors

    International Nuclear Information System (INIS)

    1995-03-01

    This booklet is a presentation of the different steps of the preparation of nuclear fuels performed by Cogema. The documents starts with a presentation of the different French reactor types: graphite moderated reactors, PWRs using MOX fuel, fast breeder reactors and research reactors. The second part describes the fuel manufacturing process: conditioning of nuclear materials and fabrication of fuel assemblies. The third part lists the different companies involved in the French nuclear fuel industry while part 4 gives a short presentation of the two Cogema's fuel fabrication plants at Cadarache and Marcoule. Part 5 and 6 concern the quality assurance, the safety and reliability aspects of fuel elements and the R and D programs. The last part presents some aspects of the environmental and personnel protection performed by Cogema. (J.S.)

  1. The evolving nuclear fuel cycle

    International Nuclear Information System (INIS)

    Gale, J.D.; Hanson, G.E.; Coleman, T.A.

    1993-01-01

    Various economics and political pressures have shaped the evolution of nuclear fuel cycles over the past 10 to 15 yr. Future trends will no doubt be similarly driven. This paper discusses the influences that long cycles, high discharge burnups, fuel reliability, and costs will have on the future nuclear cycle. Maintaining the economic viability of nuclear generation is a key issue facing many utilities. Nuclear fuel has been a tremendous bargain for utilities, helping to offset major increases in operation and maintenance (O ampersand M) expenses. An important factor in reducing O ampersand M costs is increasing capacity factor by eliminating outages

  2. Nuclear Fuel elements

    International Nuclear Information System (INIS)

    Hirakawa, Hiromasa.

    1979-01-01

    Purpose: To reduce the stress gradient resulted in the fuel can in fuel rods adapted to control the axial power distribution by the combination of fuel pellets having different linear power densities. Constitution: In a fuel rod comprising a first fuel pellet of a relatively low linear power density and a second fuel pellet of a relatively high linear power density, the second fuel pellet is cut at its both end faces by an amount corresponding to the heat expansion of the pellet due to the difference in the linear power density to the adjacent first fuel pellet. Thus, the second fuel pellet takes a smaller space than the first fuel pellet in the fuel can. This can reduce the stress produced in the portion of the fuel can corresponding to the boundary between the adjacent fuel pellets. (Kawakami, Y.)

  3. Thorium in nuclear fuel

    International Nuclear Information System (INIS)

    Stankevicius, Alejandro

    2012-01-01

    We revise the advantages and possible problems on the use of thorium as a nuclear fuel instead of uranium. The following aspects are considered: 1) In the world there are three times more thorium than uranium 2) In spite that thorium in his natural form it is not a fisil, under neutron irradiation, is possible to transform it to uranium 233, a fisil of a high quality. 3) His ceramic oxides properties are superior to uranium or plutonium oxides. 4) During the irradiation the U 233 due to n,2n reaction produce small quantities of U 232 and his decay daughters' bismuth 212 and thallium 208 witch are strong gamma source. In turn thorium 228 and uranium 232 became, in time anti-proliferate due to there radiation intensity. 5) As it is described in here and experiments done in several countries reactors PHWR can be adapted to the use of thorium as a fuel element 6) As a problem we should mentioned that the different steps in the process must be done under strong radiation shielding and using only automatized equipment s (author)

  4. The site selection process for a spent fuel repository in Finland. Summary report

    Energy Technology Data Exchange (ETDEWEB)

    McEwen, T. [EnvirosQuantiSci (United Kingdom); Aeikaes, T. [Posiva Oy, Helsinki (Finland)

    2000-12-01

    This Summary Report describes the Finnish programme for the selection and characterisation of potential sites for the deep disposal of spent nuclear fuel and explains the process by which Olkiluoto has been selected as the single site proposed for the development of a spent fuel disposal facility. Its aim is to provide an overview of this process, initiated almost twenty years ago, which has entered its final phase. It provides information in three areas: a review of the early site selection criteria, a description of the site selection process, including all the associated site characterisation work, up to the point at which a single site was selected and an outline of the proposed work, in particular that proposed underground, to characterise further the Olkiluoto site. In 1983 the Finnish Government made a policy decision on the management of nuclear waste in which the main goals and milestones for the site selection programme for the deep disposal of spent fuel were presented. According to this decision several site candidates, whose selection was to be based on careful studies of the whole country, should be characterised and the site for the repository selected by the end of the year 2000. This report describes the process by which this policy decision has been achieved. The report begins with a discussion of the definition of the geological and environmental site selection criteria and how they were applied in order to select a small number of sites, five in all, that were to be the subject of the preliminary investigations. The methods used to investigate these sites and the results of these investigations are described, as is the evaluation of the results of these investigations and the process used to discard two of the sites and continue more detailed investigations at the remaining three. The detailed site investigations that commenced in 1993 are described with respect to the overall strategy followed and the investigation techniques applied. The

  5. 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)

  6. British Nuclear Fuels (Warrington)

    International Nuclear Information System (INIS)

    Hoyle, D.; Cryer, B.; Bellotti, D.

    1992-01-01

    This adjournment debate is about British Nuclear Fuels plc and the 750 redundancies due to take place by the mid-1990s at BNFL, Risley. The debate was instigated by the Member of Parliament for Warrington, the constituency in which BNFL, Risley is situated. Other members pointed out that other industries, such as the textile industry are also suffering job losses due to the recession. However the MP for Warrington argued that the recent restructuring of BNFL restricted the financial flexibility of BNFL so that the benefits of contracts won for THORP at Sellafield could not help BNFL, Risley. The debate became more generally about training, apprentices and employment opportunities. The Parliamentary Under-Secretary of State for Energy explained the position as he saw it and said BNFL may be able to offer more help to its apprentices. Long- term employment prospects at BNFL are dependent on the future of the nuclear industry in general. The debate lasted about half an hour and is reported verbatim. (U.K)

  7. Canada's plan for the long-term management of used nuclear fuel

    Energy Technology Data Exchange (ETDEWEB)

    Shaver, K. [Nuclear Waste Management Organization, Toronto, ON (Canada)

    2015-07-01

    Our mission is to develop and implement collaboratively with Canadians, a management approach for the long-term care of Canada's used nuclear fuel that is socially acceptable, technically sound, environmentally responsible, and economically feasible. The technical method is for Isolation of used nuclear fuel in deep geological repository with continuous monitoring and potential for retrievability.

  8. Prerequisites concerning SSI:s review of applications for an encapsulation facility and a repository for spent nuclear fuel; Utgaangspunkter foer SSI:s granskning av ansoekan foer en inkapslingsanlaeggning och ett slutfoervar foer anvaent kaernbraensle

    Energy Technology Data Exchange (ETDEWEB)

    Oehlen, Elisabeth

    2006-09-15

    The report outlines some fundamental prerequisites concerning SSI:s review of SKB coming applications for an encapsulation facility (according to the act on nuclear activities) and for the complete final disposal system (according to the act on nuclear activities and the environmental code). The report summarize how the SSI look at the decision making process considering radiation protection requirements according to SSI:s regulations and general advices and earlier standpoints regarding SKB:s RandD-programme. The report also describe the present reviewing capacity of SSI and constitute therefore the basis for the planning of SSI:s review organisation in the prospect of coming applications on nuclear waste facilities (encapsulation facility and a deep disposal repository). It should be noted that the report reflects the present situation. Due to a number of factors as for example changes in SKB:s coming RandD-programme, future governmental decisions, adjustments of SSI:s financial resources or new facts in the case, will of course have an effect on how SSI finally will organise the review work. SSI:s home page will continuously be updated with the latest information in this respect.

  9. Nuclear fuel tax in court

    International Nuclear Information System (INIS)

    Leidinger, Tobias

    2014-01-01

    Besides the 'Nuclear Energy Moratorium' (temporary shutdown of eight nuclear power plants after the Fukushima incident) and the legally decreed 'Nuclear Energy Phase-Out' (by the 13th AtG-amendment), also the legality of the nuclear fuel tax is being challenged in court. After receiving urgent legal proposals from 5 nuclear power plant operators, the Hamburg fiscal court (4V 154/13) temporarily obliged on 14 April 2014 respective main customs offices through 27 decisions to reimburse 2.2 b. Euro nuclear fuel tax to the operating companies. In all respects a remarkable process. It is not in favour of cleverness to impose a political target even accepting immense constitutional and union law risks. Taxation 'at any price' is neither a statement of state sovereignty nor one for a sound fiscal policy. Early and serious warnings of constitutional experts and specialists in the field of tax law with regard to the nuclear fuel tax were not lacking. (orig.)

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

    International Nuclear Information System (INIS)

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

    1994-01-01

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

  11. Kriging analysis for a candidate nuclear waste repository

    International Nuclear Information System (INIS)

    Devary, J.L.

    1983-08-01

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

  12. Nuclear reactors and fuel cycle

    Energy Technology Data Exchange (ETDEWEB)

    NONE

    2014-07-01

    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100{sup th} nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U{sub 3}O{sub 8} were replaced by U{sub 3}Si{sub 2}-based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to

  13. Nuclear reactors and fuel cycle

    International Nuclear Information System (INIS)

    2014-01-01

    The Nuclear Fuel Center (CCN) of IPEN produces nuclear fuel for the continuous operation of the IEA-R1 research reactor of IPEN. The serial production started in 1988, when the first nuclear fuel element was delivered for IEA-R1. In 2011, CCN proudly presents the 100 th nuclear fuel element produced. Besides routine production, development of new technologies is also a permanent concern at CCN. In 2005, U 3 O 8 were replaced by U 3 Si 2 -based fuels, and the research of U Mo is currently under investigation. Additionally, the Brazilian Multipurpose Research Reactor (RMB), whose project will rely on the CCN for supplying fuel and uranium targets. Evolving from an annual production from 10 to 70 nuclear fuel elements, plus a thousand uranium targets, is a huge and challenging task. To accomplish it, a new and modern Nuclear Fuel Factory is being concluded, and it will provide not only structure for scaling up, but also a safer and greener production. The Nuclear Engineering Center has shown, along several years, expertise in the field of nuclear, energy systems and correlated areas. Due to the experience obtained during decades in research and technological development at Brazilian Nuclear Program, personnel has been trained and started to actively participate in design of the main system that will compose the Brazilian Multipurpose Reactor (RMB) which will make Brazil self-sufficient in production of radiopharmaceuticals. The institution has participated in the monitoring and technical support concerning the safety, licensing and modernization of the research reactors IPEN/MB-01 and IEA-R1. Along the last two decades, numerous specialized services of engineering for the Brazilian nuclear power plants Angra 1 and Angra 2 have been carried out. The contribution in service, research, training, and teaching in addition to the development of many related technologies applied to nuclear engineering and correlated areas enable the institution to fulfill its mission that is

  14. Studies of neo-formed phases occurring during spent nuclear fuel dissolution in geological repository: influence of silicate ions; Etude des phases neoformees lors de la dissolution du combustible nucleaire en condition de stockage geologique: influence des ions silicate

    Energy Technology Data Exchange (ETDEWEB)

    Robit-Pointeau, V

    2005-12-15

    Spent nuclear fuel alteration in deep storage conditions may proceed by local oxidising conditions at the fuel / water interface under influence of alpha irradiation. However, due to the strong redox buffer capacity of the near-field materials (especially the canister and the geological media), most of the near-field environment will remain reducing. Due to the relative high concentration in silica in such system, coffinite USiO{sub 4}.n(H{sub 2}O) may be a relevant phase to consider as it has been suggested from the natural analogues observations (Oklo). The aim of this work was to assess the relevance of coffinitisation of the spent fuel phenomena. The results of the experimental work contest the thermodynamic predictions. Instead of coffinite, a new U(IV)-Si phase has been observed in water simulating storage conditions. The thermodynamic data on coffinite validated by OECD are based on the average concentration of dissolved silica present in natural system containing uraninite and quartz. As the silica concentration in natural groundwaters is more probably controlled by minerals like chalcedony or silica gel, the coffinite present with uraninite in such systems, is probably not in equilibrium even in 2-billion years- old geological sites. Based on the results of this study, coffinitisation of the spent nuclear fuel in deep geological disposal is not anticipated to be a dominant short term process. (author)

  15. Three-dimensional thermal analysis of a baseline spent fuel repository

    International Nuclear Information System (INIS)

    Altenbach, T.J.; Lowry, W.E.

    1980-01-01

    A three-dimensional thermal analysis has been performed using finite difference techniques to determine the near-field response of a baseline spent fuel repository in a deep geologic salt medium. A baseline design incorporates previous thermal modeling experience and OWI recommendations for areal thermal loading in specifying the waste form properties, package details, and emplacement configuration. The base case in this thermal analysis considers one 10-year old PWR spent fuel assembly emplaced to yield a 36 kw/acre (8.9 w/m 2 ) loading. A unit cell model in an infinite array is used to simplify the problem and provide upper-bound temperatures. Boundary conditions are imposed which allow simulations to 1000 years. Variations studied include a comparison of ventilated and unventilated storage room conditions, emplacement packages with and without air gaps surrounding the canister, and room cool-down scenarios with ventilation following an unventilated state for retrieval purposes. At this low power level ventilating the emplacement room has an immediate cooling influence on the canister and effectively maintains the emplacement room floor near the temperature of the ventilating air. The annular gap separating the canister and sleeve causes the peak temperature of the canister surface to rise by 10 0 F (5.6 0 C) over that from a no gap case assuming perfect thermal contact. It was also shown that the time required for the emplacement room to cool down to 100 0 F (38 0 C) from an unventilated state ranged from 2 weeks to 6 months; when ventilation initiated after times of 5 years to 50 years, respectively. As the work was performed for the Nuclear Regulatory Commission, these results provide a significant addition to the regulatory data base for spent fuel performance in a geologic repository

  16. 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

  17. Review of oxidation rates of DOE spent nuclear fuel : Part 1 : nuclear fuel

    International Nuclear Information System (INIS)

    Hilton, B.A.

    2000-01-01

    The long-term performance of Department of Energy (DOE) spent nuclear fuel (SNF) in a mined geologic disposal system depends highly on fuel oxidation and subsequent radionuclide release. The oxidation rates of nuclear fuels are reviewed in this two-volume report to provide a baseline for comparison with release rate data and technical rationale for predicting general corrosion behavior of DOE SNF. The oxidation rates of nuclear fuels in the DOE SNF inventory were organized according to metallic, Part 1, and non-metallic, Part 2, spent nuclear fuels. This Part 1 of the report reviews the oxidation behavior of three fuel types prototypic of metallic fuel in the DOE SNF inventory: uranium metal, uranium alloys and aluminum-based dispersion fuels. The oxidation rates of these fuels were evaluated in oxygen, water vapor, and water. The water data were limited to pure water corrosion as this represents baseline corrosion kinetics. Since the oxidation processes and kinetics discussed in this report are limited to pure water, they are not directly applicable to corrosion rates of SNF in water chemistry that is significantly different (such as may occur in the repository). Linear kinetics adequately described the oxidation rates of metallic fuels in long-term corrosion. Temperature dependent oxidation rates were determined by linear regression analysis of the literature data. As expected the reaction rates of metallic fuels dramatically increase with temperature. The uranium metal and metal alloys have stronger temperature dependence than the aluminum dispersion fuels. The uranium metal/water reaction exhibited the highest oxidation rate of the metallic fuel types and environments that were reviewed. Consequently, the corrosion properties of all DOE SNF may be conservatively modeled as uranium metal, which is representative of spent N-Reactor fuel. The reaction rate in anoxic, saturated water vapor was essentially the same as the water reaction rate. The long-term intrinsic

  18. Reprocessing of spent nuclear fuel

    International Nuclear Information System (INIS)

    Kidd, S.

    2008-01-01

    The closed fuel cycle is the most sustainable approach for nuclear energy, as it reduces recourse to natural uranium resources and optimises waste management. The advantages and disadvantages of used nuclear fuel reprocessing have been debated since the dawn of the nuclear era. There is a range of issues involved, notably the sound management of wastes, the conservation of resources, economics, hazards of radioactive materials and potential proliferation of nuclear weapons. In recent years, the reprocessing advocates win, demonstrated by the apparent change in position of the USA under the Global Nuclear Energy Partnership (GNEP) program. A great deal of reprocessing has been going on since the fourties, originally for military purposes, to recover plutonium for weapons. So far, some 80000 tonnes of used fuel from commercial power reactors has been reprocessed. The article indicates the reprocessing activities and plants in the United Kigdom, France, India, Russia and USA. The aspect of plutonium that raises the ire of nuclear opponents is its alleged proliferation risk. Opponents of the use of MOX fuels state that such fuels represent a proliferation risk because the plutonium in the fuel is said to be 'weapon-use-able'. The reprocessing of used fuel should not give rise to any particular public concern and offers a number of potential benefits in terms of optimising both the use of natural resources and waste management.

  19. Characteristics of spent nuclear fuel

    International Nuclear Information System (INIS)

    Notz, K.J.

    1988-04-01

    The Office of Civilian Radioactive Waste Management (OCRWM) is responsible for the spent fuels and other wastes that will, or may, eventually be disposed of in a geological 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. This report deals with spent fuels, but for completeness, the other sources are described briefly. Detailed characterizations are required for all of these potential repository wastes. These characteristics include physical, chemical, and radiological properties. The latter must take into account decay as a function of time. In addition, the present inventories and projected quantities of the various wastes are needed. This information has been 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. 5 refs., 3 figs., 4 tabs

  20. Nuclear fuel storage

    International Nuclear Information System (INIS)

    Bevilacqua, F.

    1979-01-01

    A method and apparatus for the storage of fuel in a stainless steel egg crate structure within a storage pool are described. Fuel is initially stored in a checkerboard pattern or in each opening if the fuel is of low enrichment. Additional fuel (or fuel of higher enrichment) is later stored by adding stainless steel angled plates within each opening, thereby forming flux traps between the openings. Still higher enrichment fuel is later stored by adding poison plates either with or without the stainless steel angles. 8 claims

  1. Consideration of criticality in a nuclear waste repository

    International Nuclear Information System (INIS)

    Rechard, R.P.; Sanchez, L.C.; Stockman, C.T.; Ramsey, J.L. Jr.; Martell, M.

    1995-01-01

    The preliminary criticality analysis that was done suggests that the possibility of achieving critical conditions cannot be easily ruled out without looking at the geochemical process of assembly or the dynamics of the operation of a critical assembly. The evaluation of a critical assembly requires an integrated, consistent approach that includes evaluating the following: (1) the alteration rates of the layers of the container and spent fuel, (2) the transport of fissile material or neutron absorbers, and (3) the assembly mechanisms that can achieve critical conditions. The above is a non-trivial analysis and preliminary work suggests that with the loading assumed, enough fissile mass will leach from the HEU multi-purpose canisters to support a criticality. In addition, the consequences of an unpressurized Oklo type criticality would be insignificant to the performance of an unsaturated, tuff repository

  2. Transportation of spent nuclear fuels

    International Nuclear Information System (INIS)

    Meguro, Toshiichi

    1976-01-01

    The spent nuclear fuel taken out of reactors is cooled in the cooling pool in each power station for a definite time, then transported to a reprocessing plant. At present, there is no reprocessing plant in Japan, therefore the spent nuclear fuel is shipped abroad. In this paper, the experiences and the present situation in Japan are described on the transport of the spent nuclear fuel from light water reactors, centering around the works in Tsuruga Power Station, Japan Atomic Power Co. The spent nuclear fuel in Tsuruga Power Station was first transported in Apr. 1973, and since then, about 36 tons were shipped to Britain by 5 times of transport. The reprocessing plant in Japan is expected to start operation in Apr. 1977, accordingly the spent nuclear fuel used for the trial will be transported in Japan in the latter half of this year. Among the permission and approval required for the transport of spent nuclear fuel, the acquisition of the certificate for transport casks and the approval of land and sea transports are main tasks. The relevant laws are the law concerning the regulations of nuclear raw material, nuclear fuel and reactors and the law concerning the safety of ships. The casks used in Tsuruga Power Station and EXL III type, and the charging of spent nuclear fuel, the decontamination of the casks, the leak test, land transport with a self-running vehicle, loading on board an exclusive carrier and sea transport are briefly explained. The casks and the ship for domestic transport are being prepared. (Kato, I.)

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

    International Nuclear Information System (INIS)

    Surles, T.G.

    2002-01-01

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

  4. Quality assurance of nuclear fuel

    International Nuclear Information System (INIS)

    1994-01-01

    The guide presents the quality assurance requirements to be completed with in the procurement, design, manufacture, transport, handling and operation of the nuclear fuel. The guide also applies to the procurement of the control rods and the shield elements to be placed in the reactor. The guide is mainly aimed for the licensee responsible for the procurement and operation of fuel, for the fuel designer and manufacturer and for other organizations whose activities affect fuel quality, the safety of fuel transport, storage and operation. (2 refs.)

  5. Nuclear Fuel Cycle & Vulnerabilities

    Energy Technology Data Exchange (ETDEWEB)

    Boyer, Brian D. [Los Alamos National Laboratory

    2012-06-18

    The objective of safeguards is the timely detection of diversion of significant quantities of nuclear material from peaceful nuclear activities to the manufacture of nuclear weapons or of other nuclear explosive devices or for purposes unknown, and deterrence of such diversion by the risk of early detection. The safeguards system should be designed to provide credible assurances that there has been no diversion of declared nuclear material and no undeclared nuclear material and activities.

  6. Nuclear fuel assembly

    International Nuclear Information System (INIS)

    Ueda, Tomihiro.

    1970-01-01

    The present invention relates to fuel assemblies employing wire wrap spacers for retaining uniform spatial distribution between fuel elements. Clad fuel elements are helically wound in the oxial direction with a wave-formed wire strand. The strand is therefore provided with spring action which permits the fuel elements to expand freely in the axial and radial directions so as to