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)

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

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

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)

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)

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)

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)

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...

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

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

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.)

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

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)

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)

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

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

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.

Postclosure safety assessment of a used fuel repository in sedimentary rock

International Nuclear Information System (INIS)

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

2014-01-01

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

Postclosure safety assessment of a used fuel repository in sedimentary rock

Energy Technology Data Exchange (ETDEWEB)

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

2014-07-01

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

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

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.

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

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

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)

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)

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

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)

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

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)

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

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

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

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

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

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

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

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

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

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

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)

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

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.)

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

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)

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.

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

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

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)

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)

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

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

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

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

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

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)

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

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

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

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

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)

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)

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)

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)

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

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

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

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

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.

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

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

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

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

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

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

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)

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

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

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)

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)

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

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

Nuclear waste repository in basalt: preconceptual design guidelines

International Nuclear Information System (INIS)

1979-06-01

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

Nuclear waste repository in basalt: preconceptual design guidelines

Energy Technology Data Exchange (ETDEWEB)

1979-06-01

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

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.

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

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

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

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)

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.

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)

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

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

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)

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

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

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

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.

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

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

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

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

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)

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)

Safeguards for final disposal of spent nuclear fuel. Methods and technologies for the Olkiluoto site

International Nuclear Information System (INIS)

Okko, O.

2003-05-01

The final disposal of the nuclear material shall introduce new safeguards concerns which have not been addressed previously in IAEA safeguards approaches for spent fuel. The encapsulation plant to be built at the site will be the final opportunity for verification of spent fuel assemblies prior to their transfer to the geological repository. Moreover, additional safety and safeguards measures are considered for the underground repository. Integrated safeguards verification systems will also concentrate on environmental monitoring to observe unannounced activities related to possible diversion schemes at the repository site. The final disposal of spent nuclear fuel in geological formation will begin in Finland within 10 years. After the geological site investigations and according to legal decision made in 2001, the final repository of the spent nuclear fuel shall be located at the Olkiluoto site in Eurajoki. The next phase of site investigations contains the construction of an underground facility, called ONKALO, for rock characterisation purposes. The excavation of the ONKALO is scheduled to start in 2004. Later on, the ONKALO may form a part of the final repository. The plans to construct the underground facility for nuclear material signify that the first safeguards measures, e.g. baseline mapping of the site area, need to take prior to the excavation phase. In order to support the development and implementation of the regulatory control of the final disposal programme, STUK established an independent expert group, LOSKA. The group should support the STUK in the development of the technical safeguards requirements, in the implementation of the safeguards and in the evaluation of the plans of the facility operator. This publication includes four background reports produced by this group. The first of these 'NDA verification of spent fuel, monitoring of disposal canisters, interaction of the safeguards and safety issues in the final disposal' describes the new

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

Safeguards for geological repositories

International Nuclear Information System (INIS)

Fattah, A.

2000-01-01

Direct disposal of spent nuclear fuel in geological repositories is a recognised option for closing nuclear fuel cycles. Geological repositories are at present in stages of development in a number of countries and are expected to be built and operated early next century. A State usually has an obligation to safely store any nuclear material, which is considered unsuitable to re-enter the nuclear fuel cycle, isolated from the biosphere. In conjunction with this, physical protection has to be accounted for to prevent inadvertent access to such material. In addition to these two criteria - which are fully under the State's jurisdiction - a third criterion reflecting international non-proliferation commitments needs to be addressed. Under comprehensive safeguards agreements a State concedes verification of nuclear material for safeguards purposes to the IAEA. The Agency can thus provide assurance to the international community that such nuclear material has been used for peaceful purposes only as declared by the State. It must be emphasised that all three criteria mentioned constitute a 'unit'. None can be sacrificed for the sake of the other, but compromises may have to be sought in order to make their combination as effective as possible. Based on comprehensive safeguards agreements signed and ratified by the State, safeguards can be terminated only when the material has been consumed or diluted in such a way that it can no longer be utilised for any nuclear activities or has become practicably irrecoverable. As such safeguards for nuclear material in geological repositories have to be continued even after the repository has been back-filled and sealed. The effective application of safeguards must assure continuity-of-knowledge that the nuclear material in the repository has not been diverted for an unknown purpose. The nuclear material disposed in a geological repository may eventually have a higher and long term proliferation risk because the inventory is

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.

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)

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)

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

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

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)

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)

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).

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.

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.

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

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

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

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

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

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

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

Health and safety impacts related to the management of spent nuclear fuels

International Nuclear Information System (INIS)

Jilek, D.C.

1996-01-01

Under the Nuclear Waste Policy Act of 1982, as amended, the U.S. Department of Energy is responsible for managing the disposal of spent nuclear fuel from civilian nuclear power plants. Deployment of a multipurpose canister (MPC) system for dry storage of commercial spent nuclear fuel at reactor sites was determined to be an option for managing spent nuclear fuel until either a permanent repository or interim central storage facility (commonly called a Monitored Retrievable Storage Facility, or MRS) becomes available. Routine health and safety impacts to workers from handling and storage operations at nuclear facilities for four separate scenarios were evaluated for the MPC system: an on-time repository with an MRS; an on-time repository with no MRS; a delayed repository with an MRS; and a delayed repository with no MRS. In addition to evaluating the MPC system, five alternatives were analyzed. These included the No Action Alternative (NAA), Current Technology (CTr), the Transposable Storage Cask (TSC), the Dual-Purpose Canister (DPC), and the Small MPC (SmMPC). Health effects are expressed as collective doses in person- rem per year and risks as latent cancer fatalities per year for incident-free operations for each alternative and scenario. Results show that both dose and risks to workers vary as much as 68% among scenarios and alternatives. Although dose estimates and risks fall below limits for radiation dose to workers as specified in Title 10, Part 20, of the Code of Federal Regulations, additional measures could be applied to reduce potential doses and resultant health risk. 5 refs., 2 tabs

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

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

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.

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)

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

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

Nuclear fuel activity with minor actinides after their useful life in a BWR

International Nuclear Information System (INIS)

Martinez C, E.; Ramirez S, J. R.; Alonso V, G.

2016-09-01

Nuclear fuel used in nuclear power reactors has a life cycle, in which it provides energy, at the end of this cycle is withdrawn from the reactor core. This used fuel is known as spent nuclear fuel, a strong problem with this fuel is that when the fuel was irradiated in a nuclear reactor it leaves with an activity of approximately 1.229 x 10 15 Bq. The aim of the transmutation of actinides from spent nuclear fuel is to reduce the activity of high level waste that must be stored in geological repositories and the lifetime of high level waste; these two achievements would reduce the number of necessary repositories, as well as the duration of storage. The present work is aimed at evaluating the activity of a nuclear fuel in which radioactive actinides could be recycled to remove most of the radioactive material, first establishing a reference of actinides production in the standard nuclear fuel of uranium at end of its burning in a BWR, and a fuel rod design containing 6% of actinides in an uranium matrix from the enrichment tails is proposed, then 4 standard uranium fuel rods are replaced by 4 actinide bars to evaluate the production and transmutation of the same, finally the reduction of actinide activity in the fuel is evaluated. (Author)

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)

A study on dissolution and leaching behaviour of spent nuclear fuels

International Nuclear Information System (INIS)

Lee, Chang Heon; Im, Hee Jung; Kim, Jong Gu; Park, Yang Soon; Ha, Yeong Keong

2010-12-01

This state of the art report describes a leaching behaviour of spent nuclear fuels which should be considered for safety assessment of spent nuclear fuel disposal in a deep geological repository. A decisive factor of a dissolution of UO 2 , a matrix of the fuel, is chemical characters (redox potential, pH, concentration of inorganic anions, water radiolysis subsequent by radiation field of the fuels) of ground water expected to be in contact with the fuels after the container has failed due to corrosion as well as atmosphere condition of a deep geological repository, which can change the oxidation state of UO 2 . The release rates of radionuclides from UO 2 matrix depend largely on their location within the fuels, that is, the radionuclides fixed in the fuel/cladding gap and grain boundaries are rapidly released. However, the radionuclides within the grains of the fuel are slowly released, and then their release rate is governed by a dissolution behaviour of UO 2

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

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

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

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

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

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.

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)

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

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)

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

U.S. spent nuclear fuel management: Political, fiscal, and technical feasibility

International Nuclear Information System (INIS)

Singer, Clifford

2013-01-01

Successful U.S. spent nuclear fuel management policy must satisfy political, fiscal, and technical constraints. Technical requirements have been thoroughly investigated in the United States and Nordic countries for volcanic tuff, salt, and granite. Fiscal planning requires an inflation-adjusted revenue stream and predictable real interest rate earnings on fund balances. A prompt solution satisfying political constraints requires compromise between the overlapping but distinct goals of seven different sets of interests at the federal level. Absent such compromise, there will be delay until sufficient support for one of three strategies evolves: (1) force the Yucca Mountain repository on Nevada, (2) open a centralized storage facility without coupling to repository licensing, or (3) follow a “consent-based” process for repository licensing. Formulations of each of these strategies to overcome impediments to their success are described. - Highlights: • U.S. spent nuclear fuel policy has been at an impasse. • No compromise on Yucca Mountain is at hand. • Yucca only, new repository, or no repository are options. • Success with each is more likely with sounder financing

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)

Safety case for the disposal of spent nuclear fuel at Olkiluoto - Synthesis 2012

International Nuclear Information System (INIS)

2012-12-01

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a spent nuclear fuel repository. Consistent with the Government Decisions-in- Principle, this foresees a repository developed in bedrock at the Olkiluoto site according to the KBS-3 method, designed to accept spent nuclear fuel from the lifetime operations of the Olkiluoto and Loviisa reactors. Synthesis 2012 presents a synthesis of Posiva Oy's Safety Case 'TURVA-2012' portfolio. It summarises the design basis for the repository at the Olkiluoto site, the assessment methodology and key results of performance and safety assessments. It brings together all the lines of argument for safety, evaluation of compliance with the regulatory requirements, and statement of confidence in long-term safety and Posiva's safety analyses. The TURVA-2012 safety case demonstrates that the proposed repository design provides a safe solution for the disposal of spent nuclear fuel, and that the performance and safety assessments are fully consistent with all the legal and regulatory requirements related to long-term safety as set out in Government Decree 736/2008 and in guidance from the nuclear regulator - the STUK. Moreover, Posiva considers that the level of confidence in the demonstration of safety is appropriate and sufficient to submit the construction licence application to the authorities. The assessment of long-term safety includes uncertainties, but these do not affect the basic conclusions on the long-term safety of the repository. (orig.)

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.

An environmental impact measure for nuclear fuel cycle evaluation

International Nuclear Information System (INIS)

Ahn, Joonhong

2004-01-01

Review of the models and measures for repository performance assessment has revealed that dedicated measures for environmental impacts need to be developed for the purpose of nuclear-fuel-cycle evaluation from the viewpoint of environmental impact minimization. The present study proposes the total toxicity index of released radionuclides that have accumulated in the region exterior to the repository as an environmental impact measure. The measure is quantitatively evaluated by a radionuclide transport model that incorporates the effects of canister-array configuration and the initial mass loading in the waste canister. With the measure, it is demonstrated that the environmental impact of the repository can be effectively reduced by reduction of the initial mass loading and change in the canister-array configuration in the repository. Environmental impacts of the mill tailings and the depleted uranium are as important as those from the high-level radioactive wastes repository. For a fair comparison of various fuel cycles, the sum of these impacts should be compared. (author)

State fund of decommissioning of nuclear installations and handling of spent nuclear fuels and nuclear wastes (Slovak Republic)

International Nuclear Information System (INIS)

Kozma, Milos

2006-01-01

State Fund for Decommissioning of Nuclear Installations and Handling of Spent Nuclear Fuels and Nuclear Wastes was established by the Act 254/1994 of the National Council of the Slovak Republic as a special-purpose fund which concentrates financial resources intended for decommissioning of nuclear installations and for handling of spent nuclear fuels and radioactive wastes. The Act was amended in 2000, 2001 and 2002. The Fund is legal entity and independent from operator of nuclear installations Slovak Power Facilities Inc. The Fund is headed by Director, who is appointed and recalled by Minister of Economy of the Slovak Republic. Sources of the Fund are generated from: a) contributions by nuclear installation operators; b) penalties imposed by Nuclear Regulatory Authority of the Slovak Republic upon natural persons and legal entities pursuant to separate regulation; c) bank credits; d) interest on Fund deposits in banks; e) grants from State Budget; f) other sources as provided by special regulation. Fund resources may be used for the following purposes: a) decommissioning of nuclear installations; b) handling of spent nuclear fuels and radioactive wastes after the termination of nuclear installation operation; c) handling of radioactive wastes whose originator is not known, including occasionally seized radioactive wastes and radioactive materials stemming from criminal activities whose originator is not known, as confirmed by Police Corps investigator or Ministry of Health of the Slovak Republic; d) purchase of land for the establishment of nuclear fuel and nuclear waste repositories; e) research and development in the areas of decommissioning of nuclear installations and handling of nuclear fuels and radioactive wastes after the termination of the operation of nuclear installations; f) selection of localities, geological survey, preparation, design, construction, commissioning, operation and closure of repositories of spent nuclear fuels and radioactive wastes

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

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

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

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)

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

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

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

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

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

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)

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

The analysis of geological formations from Romania available for disposal of spent nuclear fuel

International Nuclear Information System (INIS)

Barariu, Gheorghe; Alecu, Catalin

2003-01-01

The majority of countries possessing nuclear power industry has not yet decided upon the option about closing the nuclear cycle. There are still in progress projects concerning the final disposal, while worldwide it is not foreseen the reprocessing of the whole amount of reusable fissionable materials. The annual worldwide production of used nuclear fuel continues to be about 10 500 - 11 000 tones of heavy metal. The difficulties in designing used fuel final disposal repositories led to the design of some interim storage facilities, providing a satisfactory safety level for biosphere. On the other hand, regardless of the selected option we respect to closing the nuclear cycle, a final repository must exists, either for the high level wastes resulted from reprocessing the used nuclear fuel or for the used fuel considered radioactive waste. Although, presently, in Romania, the nuclear fuel extracted from the reactor after its 'useful life' is declared as radioactive waste, it may contain a certain amount of fissionable material that could be used in other types of reactors. This possibility implies taking into account the concept regarding the recovery of fuel after a certain period of time, although, by definition, final disposal means prevention of this possibility. The harmonization of the Romanian legislation with that of the European Community and the adhering to the European Conventions, poses among other issues the problem of the final disposal of the used nuclear fuel. Starting from these major requirements the paper presents the main aspects of the Project 011/11.10.2001, entitled 'Researches for the selection and preliminary characterization of the host rock for the final disposal of the used nuclear fuel', part of The National Research Program: Medium, Energy and Resources. A complex analysis regarding the implications on the design of the Used Nuclear Fuel Final Disposal Repository in Romania was performed, the analysis of the available geological

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

Direct Investigations Of The Immobilization Of Radionuclides In The Alteration Phases Of Spent Nuclear Fuel

International Nuclear Information System (INIS)

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

2003-01-01

The safe disposal of the nation's nuclear waste in a geologic repository is one of the most significant and difficult scientific endeavors of the twenty-first century. Unique scientific challenges are posed by the very long-lived radioactivity of nuclear waste. Many radionuclides of vastly different chemical character must be retained by the repository for several thousand years. Some with longer half-lives, such as Pu-239 and Tc-99, need to be isolated for periods approaching a million years. In order to ensure the safety of a geologic repository, a detailed understanding of the mobility of radionuclides in complex natural systems is essential. Most of the radioactivity in a geological repository will be associated with spent nuclear fuel. In the United States spent fuel is derived from several sources. The majority is UO2 (LWR) spent fuel from commercial reactors. About 30,000 metric tons of spent fuel was in storage at commercial reactors by 1995, with the expectation that this quantity will more than double by 2010 (Integrated Data Report 1995). All spent fuel derived from commercial reactors is intended for eventual disposal in a geological repository. In addition, the DOE is the custodian of about 8000 metric tons of spent fuel, most of which is also intended for disposal in a geological repository. Although there are more than 250 types of spent fuel in the DOE inventory, the fuels may be broadly classified into (1) uranium metal fuel, (2) aluminum-based fuel, (3) mixed oxide (MOX) fuel containing substantial plutonium, and (4) graphite fuel (Colleen Shelton-Davis, personal communications, January 2000). Disposal of spent fuel in a geological repository requires detailed knowledge of the longterm behavior of the waste forms under repository conditions, as well as the fate of radionuclides released from the waste packages as containers are breached. The proposed Yucca Mountain repository is intended to hold 70,000 metric tons of high-level nuclear waste. Nine

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

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

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

Overview of adaptive phased management repository design development

International Nuclear Information System (INIS)

Russell, S.

2011-01-01

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

Safety case for the disposal of spent nuclear fuel at Olkiluoto - Synthesis 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

TURVA-2012 is Posiva's safety case in support of the Preliminary Safety Analysis Report (PSAR 2012) and application for a construction licence for a spent nuclear fuel repository. Consistent with the Government Decisions-in- Principle, this foresees a repository developed in bedrock at the Olkiluoto site according to the KBS-3 method, designed to accept spent nuclear fuel from the lifetime operations of the Olkiluoto and Loviisa reactors. Synthesis 2012 presents a synthesis of Posiva Oy's Safety Case 'TURVA-2012' portfolio. It summarises the design basis for the repository at the Olkiluoto site, the assessment methodology and key results of performance and safety assessments. It brings together all the lines of argument for safety, evaluation of compliance with the regulatory requirements, and statement of confidence in long-term safety and Posiva's safety analyses. The TURVA-2012 safety case demonstrates that the proposed repository design provides a safe solution for the disposal of spent nuclear fuel, and that the performance and safety assessments are fully consistent with all the legal and regulatory requirements related to long-term safety as set out in Government Decree 736/2008 and in guidance from the nuclear regulator - the STUK. Moreover, Posiva considers that the level of confidence in the demonstration of safety is appropriate and sufficient to submit the construction licence application to the authorities. The assessment of long-term safety includes uncertainties, but these do not affect the basic conclusions on the long-term safety of the repository. (orig.)

Nuclear Proliferation Risk Mitigation Approaches and Impacts in the Recycle of Used Nuclear Fuel in the USA

International Nuclear Information System (INIS)

Hesketh, K.; Gregg, R.; Phillips, Ch.

2009-01-01

EnergySolutions and its team partners, which include the UK National Nuclear Laboratory (NNL), are one of four industry teams to have received an award from the US Department of Energy to carry out design studies in support of the US Global Nuclear Energy Partnership (GNEP). This team has developed a detailed scenario model for a future US nuclear fuel cycle based on a closed used nuclear fuel recycle as an alternative to the current once-though-and-store system. This scenario enables the uranium and plutonium in Light Water Reactor (LWR) used fuel from the current reactor fleet, and from a fleet of replacement LWRs, to be recycled as both Uranium Oxide and Mixed Oxide (MOX) fuel using reprocessing plants that conform to the requirements of GNEP. There is also a provision for 'burning' in thermal reactors certain long-lived transuranics (Np, Am, Cm) formed into targets. The residual fission product waste, without these long-term heat emitters, will be vitrified and consigned to the US National Geologic repository. Later in the scenario a fleet of Advanced Recycle Reactors (ARR), based on sodium cooled fast reactor technology, are introduced to enable full transmutation of all transuranics and thus attain the GNEP sustainability goal. The recycle scenario avoids the need for the Yucca Mountain repository to receive unprocessed used nuclear fuel and is effective at prolonging its lifetime and delaying the need for a second repository. This paper explains the process by which EnergySolutions selected the U-Pu and U-Pu-Np MOX products and the technological requirements for the recycle plants and describes materials flow analysis that has been carried for the US nuclear fuel cycle scenario using NNL's ORION scenario modelling program. One of the prime requisites of GNEP is to ensure that the risk of proliferation is minimized and the paper describes NNL's approach to objectively assessing the proliferation risk of the scenario relative to that of a conventional recycle

Plan for spent fuel waste form testing for NNWSI [Nevada Nuclear Waste Storage Investigations

International Nuclear Information System (INIS)

Shaw, H.F.

1987-11-01

The purpose of spent fuel waste form testing is to determine the rate of release of radionuclides from failed disposal containers holding spent fuel, under conditions appropriate to the Nevada Nuclear Waste Storage Investigations (NNWSI) Project tuff repository. The information gathered in the activities discussed in this document will be used: to assess the performance of the waste package and engineered barrier system (EBS) with respect to the containment and release rate requirements of the Nuclear Regulatory Commission, as the basis for the spent fuel waste form source term in repository-scale performance assessment modeling to calculate the cumulative releases to the accessible environment over 10,000 years to determine compliance with the Environmental Protection Agency, and as the basis for the spent fuel waste form source term in repository-scale performance assessment modeling to calculate cumulative releases over 100,000 years as required by the site evaluation process specified in the DOE siting guidelines. 34 refs

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

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

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)

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

Regulations for the safe management of radioactive wastes and spent nuclear fuel

International Nuclear Information System (INIS)

Voica, Anca

2007-01-01

The paper presents the national, international and European regulations regarding radioactive waste management. ANDRAD is the national authority charged with nation wide coordination of safe management of spent fuel and radioactive waste including their final disposal. ANDRAD's main objectives are the following: - establishing the National Strategy concerning the safety management of radioactive waste and spent nuclear fuel; - establishing the national repositories for the final disposal of the spent nuclear fuel and radioactive waste; - developing the technical procedures and establishing norms for all stages of management of spent nuclear fuel and radioactive waste, including the disposal and the decommissioning of the nuclear and radiologic facilities

Multilateral controls of nuclear fuel-cycle in Asia

International Nuclear Information System (INIS)

Choi, Jor-Shan

2010-01-01

To meet increasing energy demand and climate change issues, nuclear energy is expected to expand during the next decades in both developed and developing countries. This expansion, most visibly in Asian countries would no doubt be accompanied with complex and intractable challenges to global peace and security, notably in the back-end of the nuclear fuel cycle. What to do with the growing stocks of spent fuel in existing nuclear programs? And how to reduce proliferation concerns when spent fuels are generated in less stable regions of the world? The answers to these questions may lie in the possibility of multilateral (or regional) control of nuclear materials and technologies in the back-end of nuclear fuel cycle. One of the areas of interest is technology, e.g., spent fuel treatment (reprocessing) for long term sustainability and environmental-friendly disposal of radioactive wastes, as an alternative to directly disposing spent fuel in geologic repository. The other is to seek for regional centers for centralized interim spent fuel storage which can eventually turn into disposal facilities. Such centers could help facilitate the possibilities of spent fuel take-back/take-away from countries located in less stable regions for fix-period storage. (author)

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

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

Analysis by simulation of the disposition of nuclear-fuel waste

International Nuclear Information System (INIS)

Turek, J.L.

1980-09-01

To achieve the non-proliferation objectives of the United States, the reprocessing of spent nuclear fuel was discontinued in 1977. Since current at-reactor storage capacity is based upon a nuclear fuel cycle which includes reprocessing, this halt in reprocessing is causing large quantities of non-storable spent fuel. Permanent nuclear waste storage repositories will not be available until the end of the century. Present Department of Energy policy calls for sufficient interim Away-From-Reactor (AFR) Storage capacity to insure that no commercial reactor has to shutdown due to inadequate storage space for discharged spent fuel. A descriptive simulation model is developed which includes all aspects of nuclear waste disposition. The model is comprised of two systems, the second system orchestrated by GASP IV. A spent fuel generation prediction module is interfaced with the AFR Program Management Information System and a repository scheduling information module. The user is permitted a wide range of options with which to tailor the simulation to any desired storage scenario. The model projects storage requirements through the year 2020. The outputs are evaluations of the impact that alternative decision policies and milestone date changes have on the demand for, the availability of, and the utilization of spent fuel storage capacities. Both graphs and detailed listings are available. These outputs give a comprehensive view of the particular scenario under observation, including the tracking, by year, of each discharge from every reactor. Included within the work is a review of the status of spent fuel disposition based on input data accurate as of August 1980

Criticality control during conditioning of spent nuclear fuel in the Fuel Cycle Facility

International Nuclear Information System (INIS)

Lell, R.M.; Khalil, H.S.

1994-01-01

Spent nuclear fuel may be unacceptable for direct repository storage because of composition, enrichment, form, physical condition, or the presence of undesirable materials such as sodium. Fuel types which are not acceptable for direct storage must be processed or conditioned to produce physical forms which can safely be stored in a repository. One possible approach to conditioning is the pyroprocess implemented in the Fuel Cycle Facility (FCF) at Argonne National Laboratory-West. Conditioning of binary (U-Zr) and ternary (U-Pu-Zr) metallic fuels from the EBR-2 reactor is used to demonstrate the process. Criticality safety considerations limit batch sizes during the conditioning steps and provide one constraint on the final form of conditioned material. Criticality safety during conditioning is assured by the integration of criticality safety analysis, equipment design, process development, a measurement program, accountability procedures, and a computerized Mass Tracking System. Criticality issues related to storage and shipment of conditioned material have been examined

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.

Conditioning of spent nuclear fuel for permanent disposal

International Nuclear Information System (INIS)

Laidler, J.J.

1994-01-01

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 preclude the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

Conditioning of spent nuclear fuel for permanent disposal

International Nuclear Information System (INIS)

Laidler, J.J.

1994-01-01

A compact, efficient method for conditioning spent nuclear fuel is under development. This method, known as pyrochemical processing, or pyroprocessing, 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 US 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 that avoid the substantial costs that would be associated with the qualification of the numerous spent fuel types included in the DOE inventory

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

Emerging Trends in the Nuclear Fuel Cycle: Implications for Waste Management

International Nuclear Information System (INIS)

Spradley, L.; Camper, L.; Rehmann, M.

2009-01-01

There are emerging trends in the nuclear fuel cycle that have implications for waste management. This paper will discuss activities in both the front-end and back-end of the nuclear fuel cycle for the U.S. Nuclear Regulatory Commission (NRC)-regulated entities. Particular focus will be given to the front-end which includes uranium recovery facilities, conversion facilities, and enrichment facilities. The back-end activities include progress on the proposed high-level waste geologic repository at Yucca Mountain, NV and efforts to reprocess spent nuclear fuel or down-blend HEU. While there are potential environmental impacts due to construction and dismantling of fuel cycle facilities, this paper focuses on the operational waste stream that will need to be managed as a result of fuel-cycle facilities. (authors)

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

Validation of spent nuclear fuel nuclide composition data using percentage differences and detailed analysis

Energy Technology Data Exchange (ETDEWEB)

Kim, Man Cheol [Chung-Ang Univ., Seoul (Korea, Republic of). School of Energy Systems Engineering

2017-06-15

Nuclide composition data of spent nuclear fuels are important in many nuclear engineering applications. In reactor physics, nuclear reactor design requires the nuclide composition and the corresponding cross sections. In analyzing the radiological health effects of a severe accident on the public and the environment, the nuclide composition in the reactor inventory is among the important input data. Nuclide composition data need to be provided to analyze the possible environmental effects of a spent nuclear fuel repository. They will also be the basis for identifying the origin of unidentified spent nuclear fuels or radioactive materials.

Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

International Nuclear Information System (INIS)

Ewing, Rodney C.

2003-01-01

The successful disposal of spent nuclear fuel (SNF) is one of the most serious challenges to the successful completion of the nuclear fuel cycle and the future of nuclear power generation. In the United States, 21 percent of the electricity is generated by 107 commercial nuclear power plants (NPP), each of which generates 20 metric tons of spent nuclear fuel annually. In 1996, the total accumulation of spent nuclear fuel was 33,700 metric tons of heavy metal (MTHM) stored at 70 sites around the country. The end-of-life projection for current nuclear power plants (NPP) is approximately 86,000 MTHM. In the proposed nuclear waste repository at Yucca Mountain over 95% of the radioactivity originates from spent nuclear fuel. World-wide in 1998, approximately 130,000 MTHM of SNF have accumulated, most of it located at 236 NPP in 36 countries. Annual production of SNF is approximately 10,000 MTHM, containing about 100 tons of ''reactor grade'' plutonium. Any reasonable increase in the proportion of energy production by NPP, i.e., as a substitute for hydrocarbon-based sources of energy, will significantly increase spent nuclear fuel production. Spent nuclear fuel is essentially UO 2 with approximately 4-5 atomic percent actinides and fission product elements. A number of these elements have long half-lives hence, the long-term behavior of the UO 2 is an essential concern in the evaluation of the safety and risk of a repository for spent nuclear fuel. One of the unique and scientifically most difficult aspects of the successful disposal of spent nuclear fuel is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10 3 to 10 5 years) as required by the performance objectives set in regulations, i.e. 10 CFR 60. The direct verification of these extrapolations or interpolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the public that there is a reasonable basis for

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)

The Finnish Experience with the Construction of Onkalo. Licensing of a repository for nuclear waste in Finland

International Nuclear Information System (INIS)

Avolahti, Jaana

2014-01-01

Pursuant to the Nuclear Energy Act (990/1987), a license holder whose operations result, or have resulted, in the generation of nuclear waste must perform all measures included in the management of nuclear waste and preparation thereof and bear all the costs of nuclear waste management. Under law, spent nuclear fuel is regarded as nuclear waste. According to the amendment made to the Nuclear Energy Act in 1994, nuclear waste generated in Finland must be handled, stored and permanently disposed of in Finland. Nuclear waste generated elsewhere may not be handled, stored and permanently disposed of in Finland. 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 and 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. The stepwise development and future plans for disposal are presented in Table 1. The licensing procedure for a disposal facility has several steps that are similar to all nuclear facilities in Finland and are defined in Nuclear Energy Act (990/1987) and Decree (161/1988). These licensing steps are: - Decision in Principle (DiP); - Construction License; - Operational License. An Environmental Impact Assessment (EIA) shall be conducted prior to the first authorization step of a major nuclear waste facility. The EIA procedure for the final disposal of spent nuclear fuel from three units of the Olkiluoto nuclear power plant and two units of the Loviisa nuclear power plant was carried out in 1998-1999 and extended to one more unit at Olkiluoto in 2008- 2009. Pursuant to the Nuclear Energy Act, before making the DiP the Government shall ascertain whether the municipality planned as the location of the nuclear facility is in favour of the facility, and ensure that no facts indicating a

Proceedings of GLOBAL 2007 conference on advanced nuclear fuel cycles and systems

International Nuclear Information System (INIS)

2007-01-01

In keeping with the 12-year history of this conference, GLOBAL 2007 focuses on future nuclear energy systems and fuel cycles. With the increasing public acceptance and political endorsement of nuclear energy, it is a pivotal time for nuclear energy research. Significant advances have been made in development of advanced nuclear fuels and materials, reactor designs, partitioning, transmutation and reprocessing technologies, and waste management strategies. In concert with the technological advances, it is more important than ever to develop sensible nuclear proliferation policies, to promote sustainability, and to continue to increase international collaboration. To further these aims, GLOBAL 2007 highlights recent developments in the following areas: advanced integrated fuel cycle concepts, spent nuclear fuel reprocessing, advanced reprocessing technology, advanced fuels and materials, advanced waste management technology, novel concepts for waste disposal and repository development, advanced reactors, partitioning and transmutation, developments in nuclear non-proliferation technology, policy, and implementation, sustainability and expanded global utilization of nuclear energy, and international collaboration on nuclear energy

United States Program on Spent Nuclear Fuel and High-Level Radioactive Waste Management

International Nuclear Information System (INIS)

Stewart, L.

2004-01-01

The President signed the Congressional Joint Resolution on July 23, 2002, that designated the Yucca Mountain site for a proposed geologic repository to dispose of the nation's spent nuclear fuel (SNF) and high-level radioactive waste (HLW). The United States (U.S.) Department of Energy's (DOE) Office of Civilian Radioactive Waste Management (OCRWM) is currently focusing its efforts on submitting a license application to the U.S. Nuclear Regulatory Commission (NRC) in December 2004 for construction of the proposed repository. The legislative framework underpinning the U.S. repository program is the basis for its continuity and success. The repository development program has significantly benefited from international collaborations with other nations in the Americas

Performance assessment of DOE spent nuclear fuel and surplus plutonium

International Nuclear Information System (INIS)

Duguid, J.O.; Vallikat, V.; McNeish, J.

1998-01-01

Yucca Mountain, in southern Nevada, is under consideration by the US Department of Energy (DOE) as a potential site for the disposal of the nation's radioactive wastes in a geologic repository. The wastes consist of commercial spent fuel, DOE spent nuclear fuel (SNF), high level waste (HLW), and surplus plutonium. The DOE was mandated by Congress in the fiscal 1997 Energy and Water Appropriations Act to complete a viability assessment (VA) of the repository in September of 1998. The assessment consists of a preliminary design concept for the critical elements of the repository, a total system performance assessment (TSPA), a plan and cost estimate for completion of the license application, and an estimate of the cost to construct and operate the repository. This paper presents the results of the sensitivity analyses that were conducted to examine the behavior of DOE SNF and plutonium waste forms in the environment of the base case repository that was modeled for the TSPA-VA. Fifteen categories of DOE SNF and two Plutonium waste forms were examined and their contribution to radiation dose to humans was evaluated

Diversion path analysis for the Swedish geological repository

International Nuclear Information System (INIS)

Fritzell, Anni; Meer, Klaas Van Der

2008-02-01

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

Diversion path analysis for the Swedish geological repository

Energy Technology Data Exchange (ETDEWEB)

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

2008-02-15

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

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

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.

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)

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)

Implementation process and deployment initiatives for the regionalized storage of DOE-owned spent nuclear fuel

International Nuclear Information System (INIS)

Dearien, J.A.; Smith, N.E.L.

1995-01-01

This report describes how DOE-owned spent nuclear fuel (SNF) will be stored in the interim 40-year period from 1996 to 2035, by which time it is expected to be in a National Nuclear Repository. The process is described in terms of its primary components: fuel inventory, facilities where it is stored, how the fuel will be moved, and legal issues associated with the process. Tools developed to deploy and fulfill the implementation needs of the National Spent Nuclear Fuel Program are also discussed

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)

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

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

Microbial biofilm growth on irradiated, spent nuclear fuel cladding

International Nuclear Information System (INIS)

Bruhn, D.F.; Frank, S.M.; Roberto, F.F.; Pinhero, P.J.; Johnson, S.G.

2009-01-01

A fundamental criticism regarding the potential for microbial influenced corrosion in spent nuclear fuel cladding or storage containers concerns whether the required microorganisms can, in fact, survive radiation fields inherent in these materials. This study was performed to unequivocally answer this critique by addressing the potential for biofilm formation, the precursor to microbial-influenced corrosion, in radiation fields representative of spent nuclear fuel storage environments. This study involved the formation of a microbial biofilm on irradiated spent nuclear fuel cladding within a hot cell environment. This was accomplished by introducing 22 species of bacteria, in nutrient-rich media, to test vessels containing irradiated cladding sections and that was then surrounded by radioactive source material. The overall dose rate exceeded 2 Gy/h gamma/beta radiation with the total dose received by some of the bacteria reaching 5 x 10 3 Gy. This study provides evidence for the formation of biofilms on spent-fuel materials, and the implication of microbial influenced corrosion in the storage and permanent deposition of spent nuclear fuel in repository environments

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

How many geologic repositories will be needed

International Nuclear Information System (INIS)

Evans, T.J.; Halstead, R.J.

1987-01-01

DOE's postponement of site-specific work on the second repository program had rekindled debate over the number of geologic repositories needed for disposal of high level radioactive waste. The multiple repository approach grew out of the March, 1979 IRG report, which recommended co-disposal of civilian and defense HLW in a system of regional repositories. The multiple repository approach was adopted by DOE, and incorporated in the Nuclear Waste Policy Act passed by Congress in December, 1982. Since the late 1970's, the slower than anticipated growth of the nuclear power industry has substantially reduced earlier estimates of the amount of civilian spent fuel which will require geologic disposal. Reactors currently in operation (78.5 GWe) and reactors in the construction pipeline (28 GWe) are expected to discharge about 103,200 MTU of spent fuel by the year 2036, assuming no increase in fuel burnup rate. By the year 2020, defense high level radioactive wastes equivalent to as much as 27,000 MTU could require geologic disposal. Small amounts of high level waste from other sources will also require geologic disposal. Total disposal requirements appear to be less than 140,000 MTU. The five sites nominated for the first repository, as well as hypothetical sites in granite, the host rock under primary consideration for the second repository, all appear capable of accommodating up to 140,000 MTU

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

Management of waste from french nuclear fuel cycle: what are the key issues?

International Nuclear Information System (INIS)

Londres, V.; Do Quang, R.; Fournier, P.

2000-01-01

Like any other industry, the nuclear industry generates waste. This waste arises in the different successive stages of the fuel cycle, including nuclear power plants, and its physical and chemical properties vary greatly. What is special about it is the radioactivity it contains. Management of waste generated by spent fuel conditioning in nuclear reprocessing facilities, and which cannot be stored in surface repositories, according to current French regulations (ILW and HLW), is specifically discussed in this paper. (authors)

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)

Radioactive waste management and spent nuclear fuel storing. Options and priorities

International Nuclear Information System (INIS)

Popescu, Ion

2001-01-01

As a member of the states' club using nuclear energy for peaceful applications, Romania approaches all the activities implied by natural uranium nuclear fuel cycle, beginning with uranium mining and ending with electric energy generation. Since, in all steps of the nuclear fuel cycle radioactive wastes are resulting, in order to protect the environment and the life, the correct and competent radioactive waste management is compulsory. Such a management implies: a. Separating the radioisotopes in all the effluences released into environment; b. Treating separately the radioisotopes to be each properly stored; c. Conditioning waste within resistant matrices ensuring long term isolation of the radioactive waste destined to final disposal; d. Building radioactive waste repositories with characteristics of isolation guaranteed for long periods of time. To comply with the provisions of the International Convention concerning the safety of the spent nuclear fuel and radioactive waste management, signed on 5 September 1997, Romania launched its program 'Management of Radioactive Wastes and Dry Storing of Spent Nuclear Fuel' having the following objectives: 1. Establishing the technology package for treating and conditioning the low and medium active waste from Cernavoda NPP to prepare them for final disposal; 2. Geophysical and geochemical investigations of the site chosen for the low and medium active final disposal (DFDSMA); 3. Evaluating the impact on environment and population of the DFDSMA; 4. Providing data necessary in the dry intermediate storing of spent nuclear fuel and the continuous and automated surveillance; 5. Establishing multiple barriers for spent nuclear fuel final disposal in order to establish the repository in granitic rocks and salt massives; 6. Designing and testing containers for final disposal of spent nuclear fuel guaranteeing the isolation over at least 500 years; 7. Computational programs for evaluation of radionuclide leakage in environment in

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

Attitudes and opposition in siting a high level nuclear waste repository

International Nuclear Information System (INIS)

Sjoeberg, L.; Viklund, M.; Truedsson, J.

1998-09-01

In Sweden, the Swedish Nuclear Fuel and Waste Management Company (SKB) handles all issues concerning nuclear waste, including the siting process, in which the final outcome is intended to be a repository for high level nuclear waste placed deep down in bedrock. The main objective of the siting process is to find a host community fulfilling two important conditions: the safety demands have been met and agreements with the municipality can be accomplished. Only in such municipalities, so-called feasibility studies will be conducted. After conducting general studies in the whole country, SKB, in October 1992, sent letters with information about the intended feasibility studies to all Swedish municipalities. As a result, feasibility studies are or have been considered - and in some cases also been conducted - in eleven Swedish municipalities up until 1998. These are the municipalities where the attitudes and opposition towards a feasibility study, and possibly a final repository, are studied. The discussion can be divided into three main parts: Management of the siting process; Inherent 'chaotic' processes and/or factors and risk perception. It is argued that two important problems could have been avoided at least partly: The citizens in many municipalities were uncertain of the relationship between a feasibility study and a final repository, and in many municipalities the citizens were afraid that the Government could overrule the municipal veto. Because of these fears, a common argument among the opponents of a feasibility study was: 'to be sure of not receiving a final repository, we say no to a feasibility study'. Some inherent factors, more or less prevalent in the municipalities as well as in society in general, may also partly explain the outcome of the siting process. The municipalities in which the debate has been heated, and where public support has been more difficult to reach, share some common characteristics. Esp. in the municipalities in the north of

Attitudes and opposition in siting a high level nuclear waste repository

Energy Technology Data Exchange (ETDEWEB)

Sjoeberg, L.; Viklund, M.; Truedsson, J

1998-09-01

In Sweden, the Swedish Nuclear Fuel and Waste Management Company (SKB) handles all issues concerning nuclear waste, including the siting process, in which the final outcome is intended to be a repository for high level nuclear waste placed deep down in bedrock. The main objective of the siting process is to find a host community fulfilling two important conditions: the safety demands have been met and agreements with the municipality can be accomplished. Only in such municipalities, so-called feasibility studies will be conducted. After conducting general studies in the whole country, SKB, in October 1992, sent letters with information about the intended feasibility studies to all Swedish municipalities. As a result, feasibility studies are or have been considered - and in some cases also been conducted - in eleven Swedish municipalities up until 1998. These are the municipalities where the attitudes and opposition towards a feasibility study, and possibly a final repository, are studied. The discussion can be divided into three main parts: Management of the siting process; Inherent `chaotic` processes and/or factors and risk perception. It is argued that two important problems could have been avoided at least partly: The citizens in many municipalities were uncertain of the relationship between a feasibility study and a final repository, and in many municipalities the citizens were afraid that the Government could overrule the municipal veto. Because of these fears, a common argument among the opponents of a feasibility study was: `to be sure of not receiving a final repository, we say no to a feasibility study`. Some inherent factors, more or less prevalent in the municipalities as well as in society in general, may also partly explain the outcome of the siting process. The municipalities in which the debate has been heated, and where public support has been more difficult to reach, share some common characteristics. Esp. in the municipalities in the north of

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.

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)

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)

Concerns when designing a safeguards approach for the back-end of the Swedish nuclear fuel cycle

International Nuclear Information System (INIS)

Fritzell, Anni

2006-03-01

In Sweden, the construction of an encapsulation plant and a geological repository for the final disposal of spent nuclear fuel is planned to start within the next ten years. Due to Sweden's international agreements on non-proliferation, the Swedish safeguards regime must be extended to include these facilities. The geological repository has some unique features, which present the safeguards system with unprecedented challenges. These features include, inter alia, the long period of time that the facility will contain nuclear material and that the disposed nuclear material will be very difficult to access, implying that physical verification of its presence in the repository is not foreseen. This work presents the available techniques for creating a safeguards system for the backend of the Swedish nuclear fuel cycle. Important issues to consider in the planning and implementation of the safeguards system have been investigated, which in some cases has led to an identification of areas needing further research. The results include three proposed options for a safeguards approach, which have been evaluated on the basis of the safeguards authorities' requirements. Also, the evolution and present situation of the work carried out in connection to safeguards for geological repositories has been compiled

The strategy of the long-term back-end nuclear fuel cycle in the Czech Republic

International Nuclear Information System (INIS)

Palagyi, S.; Fajman, V.

2002-01-01

The present status of the strategy of the long-term back-end nuclear fuel cycle in the Czech Republic is briefly outlined in this paper. This strategy is based on the once-through option in the use of the nuclear fuel with subsequent interim storage of the spent fuel and its final disposal as a declared high level waste. However, other technologies for the management of the back-end of the nuclear fuel cycle are not excluded at all. Besides the first already existing and the second interim spent fuel storage facility being sited at Dukovany Nuclear Power Plant, an interim spent fuel storage facility at Temelin Nuclear Power Plant is also under the siting process. To cover the total storing needs a central spent nuclear fuel interim storage facility at Skalka in the Czech-Moravian Highlands is also under consideration. These facilities are or will be equipped with dry-storage containers of cask-type placed in the concrete building and cooled by natural air ventilation. Since 1993 there is a joint effort of several governmental organisations and institutions and private companies to study the scientific, technical and economical possibilities of the construction of the deep geological repository for spent nuclear fuel disposal. A horizontal repository facility with vertical access was selected and a reference project has been accepted. A time horizon for construction in about the year of 2035 was scheduled. The necessary legal and administrative basis of the spent fuel and radioactive waste management was laid down by the law No. 18/1997 (Atomic Act) passed in 1997. This basic law with its implementing regulations fully reflects the internationally accepted principles of the provision of nuclear safety and radiation protection in this respect and it also strongly supports the policy and strategy of the back-end of the nuclear fuel cycle. (author)

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

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.

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

Identification of key radionuclides in a nuclear waste repository in basalt

International Nuclear Information System (INIS)

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

1980-05-01

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

A safeguards approach for a closed geological repository for spent fuel

International Nuclear Information System (INIS)

Meer, K. van der; Carchon, R.

1999-01-01

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

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

International Nuclear Information System (INIS)

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

1998-04-01

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

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

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

Exploring nuclear energy scenarios - implications of technology and fuel cycle choices

International Nuclear Information System (INIS)

Rayment, Fiona; Mathers, Dan; Gregg, Robert

2014-01-01

Nuclear Energy is recognised globally as a mature, reliable low carbon technology with a secure and abundant fuel source. Within the UK, Nuclear Energy is an essential contributor to the energy mix and as such a decision has been made to refresh the current nuclear energy plants to at least replacement of the existing nuclear fleet. This will mean the building of new nuclear power plant to ensure energy production of 16 GWe per annum. However it is also recognised that this may not be enough and as such expansion scenarios ranging from replacement of the existing fleet to 75 GWe nuclear energy capacity are being considered (see appendix). Within these energy scenarios, a variety of options are being evaluated including electricity generation only, electricity generation plus heat, open versus closed fuel cycles, Generation III versus Generation IV systems and combinations of the above. What is clear is that the deciding factor on the type and mix of any energy programme will not be on technology choice alone. Instead a complex mix of Government policy, relative cost of nuclear power, market decisions and public opinion will influence the rate and direction of growth of any future energy programme. The UK National Nuclear Laboratory has supported this work through the use and development of a variety of assessment and modelling techniques. When assessing nuclear energy scenarios, the technology chosen will impact on a number of parameters within each scenario which includes but is not limited to: - Economics, - Nuclear energy demand, - Fuel Supply, - Spent fuel storage / recycle, - Geological repository volumetric and radiological capacity, - Sustainability - effective resource utilisation, - Technology viability and readiness level. A number of assessment and modelling techniques have been developed and are described further. In particular, they examine fuel cycle options for a number of nuclear energy scenarios, whilst exploring key implications for a particular

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)

Nuclear fuel activity with minor actinides after their useful life in a BWR; Actividad del combustible nuclear con actinidos menores despues de su vida util en un reactor BWR

Energy Technology Data Exchange (ETDEWEB)

Martinez C, E.; Ramirez S, J. R.; Alonso V, G., E-mail: eduardo.martinez@inin.gob.mx [ININ, Carretera Mexico-Toluca s/n, 52750 Ocoyoacac, Estado de Mexico (Mexico)

2016-09-15

Nuclear fuel used in nuclear power reactors has a life cycle, in which it provides energy, at the end of this cycle is withdrawn from the reactor core. This used fuel is known as spent nuclear fuel, a strong problem with this fuel is that when the fuel was irradiated in a nuclear reactor it leaves with an activity of approximately 1.229 x 10{sup 15} Bq. The aim of the transmutation of actinides from spent nuclear fuel is to reduce the activity of high level waste that must be stored in geological repositories and the lifetime of high level waste; these two achievements would reduce the number of necessary repositories, as well as the duration of storage. The present work is aimed at evaluating the activity of a nuclear fuel in which radioactive actinides could be recycled to remove most of the radioactive material, first establishing a reference of actinides production in the standard nuclear fuel of uranium at end of its burning in a BWR, and a fuel rod design containing 6% of actinides in an uranium matrix from the enrichment tails is proposed, then 4 standard uranium fuel rods are replaced by 4 actinide bars to evaluate the production and transmutation of the same, finally the reduction of actinide activity in the fuel is evaluated. (Author)

THE ECONOMICS OF REPROCESSING vs. DIRECT DISPOSAL OF SPENT NUCLEAR FUEL

International Nuclear Information System (INIS)

Bunn, Matthew; Fetter, Steve; Holdren, John P.; Zwaan, Bob van der

2003-01-01

This report assesses the economics of reprocessing versus direct disposal of spent nuclear fuel. The breakeven uranium price at which reprocessing spent nuclear fuel from existing light-water reactors (LWRs) and recycling the resulting plutonium and uranium in LWRs would become economic is assessed, using central estimates of the costs of different elements of the nuclear fuel cycle (and other fuel cycle input parameters), for a wide range of range of potential reprocessing prices. Sensitivity analysis is performed, showing that the conclusions reached are robust across a wide range of input parameters. The contribution of direct disposal or reprocessing and recycling to electricity cost is also assessed. The choice of particular central estimates and ranges for the input parameters of the fuel cycle model is justified through a review of the relevant literature. The impact of different fuel cycle approaches on the volume needed for geologic repositories is briefly discussed, as are the issues surrounding the possibility of performing separations and transmutation on spent nuclear fuel to reduce the need for additional repositories. A similar analysis is then performed of the breakeven uranium price at which deploying fast neutron breeder reactors would become competitive compared with a once-through fuel cycle in LWRs, for a range of possible differences in capital cost between LWRs and fast neutron reactors. Sensitivity analysis is again provided, as are an analysis of the contribution to electricity cost, and a justification of the choices of central estimates and ranges for the input parameters. The equations used in the economic model are derived and explained in an appendix. Another appendix assesses the quantities of uranium likely to be recoverable worldwide in the future at a range of different possible future prices

Resolving Past Liabilities for Future Reduction in Greenhouse Gases; Nuclear Energy and the Outstanding Federal Liability of Spent Nuclear Fuel

Science.gov (United States)

Donohue, Jay

This thesis will: (1) examine the current state of nuclear power in the U.S.; (2) provide a comparison of nuclear power to both existing alternative/renewable sources of energy as well as fossil fuels; (3) dissect Standard Contracts created pursuant to the National Waste Policy Act (NWPA), Congress' attempt to find a solution for Spent Nuclear Fuel (SNF), and the designation of Yucca Mountain as a repository; (4) the anticipated failure of Yucca Mountain; (5) explore WIPP as well as attempts to build a facility on Native American land in Utah; (6) examine reprocessing as a solution for SNF used by France and Japan; and, finally, (7) propose a solution to reduce GHG's by developing new nuclear energy plants with financial support from the U.S. government and a solution to build a storage facility for SNF through the sitting of a repository based on a "bottom-up" cooperative federalism approach.

Corrosion of Spent Nuclear Fuel: The Long-Term Assessment

Energy Technology Data Exchange (ETDEWEB)

Ewing, Rodney C.

2003-09-14

The successful disposal of spent nuclear fuel (SNF) is one of the most serious challenges to the successful completion of the nuclear fuel cycle and the future of nuclear power generation. In the United States, 21 percent of the electricity is generated by 107 commercial nuclear power plants (NPP), each of which generates 20 metric tons of spent nuclear fuel annually. In 1996, the total accumulation of spent nuclear fuel was 33,700 metric tons of heavy metal (MTHM) stored at 70 sites around the country. The end-of-life projection for current nuclear power plants (NPP) is approximately 86,000 MTHM. In the proposed nuclear waste repository at Yucca Mountain over 95% of the radioactivity originates from spent nuclear fuel. World-wide in 1998, approximately 130,000 MTHM of SNF have accumulated, most of it located at 236 NPP in 36 countries. Annual production of SNF is approximately 10,000 MTHM, containing about 100 tons of ''reactor grade'' plutonium. Any reasonable increase in the proportion of energy production by NPP, i.e., as a substitute for hydrocarbon-based sources of energy, will significantly increase spent nuclear fuel production. Spent nuclear fuel is essentially UO{sub 2} with approximately 4-5 atomic percent actinides and fission product elements. A number of these elements have long half-lives hence, the long-term behavior of the UO{sub 2} is an essential concern in the evaluation of the safety and risk of a repository for spent nuclear fuel. One of the unique and scientifically most difficult aspects of the successful disposal of spent nuclear fuel is the extrapolation of short-term laboratory data (hours to years) to the long time periods (10{sup 3} to 10{sup 5} years) as required by the performance objectives set in regulations, i.e. 10 CFR 60. The direct verification of these extrapolations or interpolations is not possible, but methods must be developed to demonstrate compliance with government regulations and to satisfy the

International co-operation in the supply of nuclear fuel and fuel cycle services

International Nuclear Information System (INIS)

Sievering, N.F. Jr.

1977-01-01

Recent changes in the United States' nuclear policy, in recognition of the increased proliferation risk, have raised questions of US intentions in international nuclear fuel and fuel-cycle service co-operation. This paper details those intentions in relation to the key elements of the new policy. In the past, the USA has been a world leader in peaceful nuclear co-operation with other nations and, mindful of the relationships between civilian nuclear technology and nuclear weapon proliferation, remains strongly committed to the Non-Proliferation Treaty, IAEA safeguards and other elements concerned with international nuclear affairs. Now, in implementing President Carter's nuclear initiatives, the USA will continue its leading role in nuclear fuel and fuel-cycle co-operation in two ways, (1) by increasing its enrichment capacity for providing international LWR fuel supplies and (2) by taking the lead in solving the problems of near and long-term spent fuel storage and disposal. Beyond these specific steps, the USA feels that the international community's past efforts in controlling the proliferation risks of nuclear power are necessary but inadequate for the future. Accordingly, the USA urges other similarly concerned nations to pause with present developments and to join in a programme of international co-operation and participation in a re-assessment of future plans which would include: (1) Mutual assessments of fuel cycles alternative to the current uranium/plutonium cycle for LWRs and breeders, seeking to lessen proliferation risks; (2) co-operative mechanisms for ensuring the ''front-end'' fuel supply including uranium resource exploration, adequate enrichment capacity, and institutional arrangements; (3) means of dealing with short-, medium- and long-term spent fuel storage needs by means of technical co-operation and assistance and possibly establishment of international storage or repository facilities; and (4) for reprocessing plants, and related fuel

Reference Design Description for a Geologic Repository

International Nuclear Information System (INIS)

2000-01-01

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

Nuclear Waste Policy Act of 1982; proposed general guidelines for recommendation of sites for nuclear waste repositories

International Nuclear Information System (INIS)

Anon.

1983-01-01

In accordance with the requirements of the Nuclear Waste Policy Act of 1982 (Pub. L. 97-425), hereinafter referred to as the Act, the Department of Energy is proposing general guidelines for the recommendation of sites for repositories for disposal of high-level radioactive waste and spent nuclear fuel in geologic formations. These guidelines are based on the criteria that the Department has used in its National Waste Terminal Storage program, the criteria proposed by the Nuclear Regulatory Commission (NRC), and the environmental standards proposed by the Environmental Protection Agency. These guidelines establish the performance requirements for a geologic repository system, specify how the Department will implement its site-selection program, and define the technical qualifications that candidate sites must meet in the various steps of the site-selection process mandated by the Act. After considering comments from the public; consulting with the Council on Environmental Quality, the Administrator of the Environmental Protection Agency, the Director of the Geological Survey, and interested Governors; and obtaining NRC concurrence, the Department will issue these guidelines in final form as a new Part 960 to Title 10 of the Code of Federal Regulations (10 CFR Part 960)

Redesign of the spent fuel storage racks at the Trojan Nuclear Plant

International Nuclear Information System (INIS)

Stump, K.

1987-01-01

The spent fuel pool (SFP) at the Trojan Nuclear Plant located near Prescott, Oregon, was originally designed to hold 1.33 cores worth of spent fuel assemblies. Due to the delay in the site selection and preparation process for the spent fuel repository, the SFP storage capacity was increased in 1978 from 260 assemblies to 651 assemblies and in 1983 was increased again from 651 to 1408 assemblies to allow Trojan to continue operations through the year 2003 with a full core reserve in the SFP. Now it appears unlikely that a high level waste repository will be in operation before 2010. This indicates that a further capacity increase in the SFP is required to allow commercial operation until 2010, at which time the repository should be open to receive spent fuel. To accomplish this, an increase of seven times the original SFP capacity of 260 assemblies is needed. This paper presents a spent fuel assembly rack design that enables the required capacity increase in the SFP to be met. By the use of a boron carbide - silicon polymer inside a titanium/vanadium honeycomb as a neutron absorber between the fuel assemblies and by increasing the metal to water ratio of the spent fuel pool to harden the neutron energy spectrum the capacity of the SFP is increased to 1880 assemblies for an increase of 7.23 times the original spent fuel pool capacity. The multiplication factor for the pool with every fuel assembly slot filled in the new rack system is 0.62; well below the NRC regulatory limit of keff < 0.95. The capacity increase with allow the commercial operation of the Trojan Nuclear Plant through 2010 with a full core reserve in the spent fuel pool

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

IAEA safeguards for geological repositories

International Nuclear Information System (INIS)

Moran, B.W.

2005-01-01

In September. 1988, the IAEA held its first formal meeting on the safeguards requirements for the final disposal of spent fuel and nuclear material-bearing waste. The consensus recommendation of the 43 participants from 18 countries at this Advisory Group Meeting was that safeguards should not terminate of spent fuel even after emplacement in, and closure of, a geologic repository.' As a result of this recommendation, the IAEA initiated a series of consultants' meetings and the SAGOR Programme (Programme for the Development of Safeguards for the Final Disposal of Spent Fuel in Geologic Repositories) to develop an approach that would permit IAEA safeguards to verify the non-diversion of spent fuel from a geologic repository. At the end of this process, in December 1997, a second Advisory Group Meeting, endorsed the generic safeguards approach developed by the SAGOR Programme. Using the SAGOR Programme results and consultants' meeting recommendations, the IAEA Department of Safeguards issued a safeguards policy paper stating the requirements for IAEA safeguards at geologic repositories. Following approval of the safeguards policy and the generic safeguards approach, the Geologic Repository Safeguards Experts Group was established to make recommendations on implementing the safeguards approach. This experts' group is currently making recommendations to the IAEA regarding the safeguards activities to be conducted with respect to Finland's repository programme. (author)

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

Groundwater flow modelling of an abandoned partially open repository

Energy Technology Data Exchange (ETDEWEB)

Bockgaard, Niclas (Golder Associates AB (Sweden))

2010-12-15

As a part of the license application, according to the nuclear activities act, for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study presented here serves as an input for analyses of so-called future human actions that may affect the repository. The objective of the work was to investigate the hydraulic influence of an abandoned partially open repository. The intention was to illustrate a pessimistic scenario of the effect of open tunnels in comparison to the reference closure of the repository. The effects of open tunnels were studied for two situations with different boundary conditions: A 'temperate' case with present-day boundary conditions and a generic future 'glacial' case with an ice sheet covering the repository. The results were summarized in the form of analyses of flow in and out from open tunnels, the effect on hydraulic head and flow in the surrounding rock volume, and transport performance measures of flow paths from the repository to surface

Groundwater flow modelling of an abandoned partially open repository

International Nuclear Information System (INIS)

Bockgaard, Niclas

2010-12-01

As a part of the license application, according to the nuclear activities act, for a final repository for spent nuclear fuel at Forsmark, the Swedish Nuclear Fuel and Waste Management Company (SKB) has undertaken a series of groundwater flow modelling studies. These represent time periods with different hydraulic conditions and the simulations carried out contribute to the overall evaluation of the repository design and long-term radiological safety. The modelling study presented here serves as an input for analyses of so-called future human actions that may affect the repository. The objective of the work was to investigate the hydraulic influence of an abandoned partially open repository. The intention was to illustrate a pessimistic scenario of the effect of open tunnels in comparison to the reference closure of the repository. The effects of open tunnels were studied for two situations with different boundary conditions: A 'temperate' case with present-day boundary conditions and a generic future 'glacial' case with an ice sheet covering the repository. The results were summarized in the form of analyses of flow in and out from open tunnels, the effect on hydraulic head and flow in the surrounding rock volume, and transport performance measures of flow paths from the repository to surface

Melt-Dilute Spent Nuclear Fuel Form Criticality Summary Report; FINAL

International Nuclear Information System (INIS)

Vinson, D.W.

2002-01-01

Criticality analysis of the proposed Melt-Dilute (MD) form of aluminum-based spent nuclear fuel (SNF), under geologic repository conditions, was performed following the methodology, documented in the Disposal Criticality Analysis Methodology Topical Report. This methodology evaluates the potential for nuclear criticality as determined by the composition of the waste and its geometry, namely waste form configuration, including presence of moderator, reflecting structural material, and neutron absorbers. The initial emplaced configuration of the SNF form is a dry package placed in a mined repository passageway. Criticality calculations show that even with waste package failure, followed by degradation of material within the waste package and potential loss of neutron absorber materials, sub-critical conditions can be maintained

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.

A High Integrity Can Design for Degraded Nuclear Fuel

International Nuclear Information System (INIS)

Holmes, P.A.

1999-01-01

A high integrity can (HIC), designed to meet the ASME Boiler and Pressure Vessel Code (Section III, Div. 3, static conditions) is proposed for the interim storage and repository disposal of Department of Energy (DOE) spent nuclear fuel. The HIC will be approximately 5 3/8 inches (134.38mm) in outside diameter with 1/4 inch (6.35mm) thick walls, and have a removable lid with a metallic seal that is capable of being welded shut. The opening of the can is approximately 4 3/8 inches (111.13mm). The HIC is primarily designed to contain items in the DOE SNF inventory that do not meet acceptance standards for direct disposal in a geologic repository. This includes fuel in the form of particulate dusts, sectioned pieces of fuel, core rubble, melted or degraded (non-intact) fuel elements, unclad uranium alloys, metallurgical specimens, and chemically reactive fuel components. The HIC is intended to act as a substitute cladding for the spent nuclear fuel, further isolate problematic materials, provide a long-term corrosion barrier, and add an extra internal pressure barrier to the waste package. The HIC will also delay potential fission product release and maintain geometry control for extended periods of time. For the entire disposal package to be licensed by the Nuclear Regulatory Commission, a HIC must effectively eliminate the disposal problems associated with problem SNF including the release of radioactive and/or reactive material and over pressurization of the HIC due to chemical reactions within the can. Two HICs were analyzed to envelop a range of can lengths between 42 and 101 inches. Using Abacus software, the HIC's were analyzed for end, side, and corner drops. Hastelloy C-22 was chosen based upon structural integrity, corrosion resistance, and neutron adsorption properties

Options for treating high-temperature gas-cooled reactor fuel for repository disposal

Energy Technology Data Exchange (ETDEWEB)

Lotts, A.L.; Bond, W.D.; Forsberg, C.W.; Glass, R.W.; Harrington, F.E.; Micheals, G.E.; Notz, K.J.; Wymer, R.G.

1992-02-01

This report describes the options that can reasonably be considered for disposal of high-temperature gas-cooled reactor (HTGR) fuel in a repository. The options include whole-block disposal, disposal with removal of graphite (either mechanically or by burning), and reprocessing of spent fuel to separate the fuel and fission products. The report summarizes what is known about the options without extensively projecting or analyzing actual performance of waste forms in a repository. The report also summarizes the processes involved in convert spent HTGR fuel into the various waste forms and projects relative schedules and costs for deployment of the various options. Fort St. Vrain Reactor fuel, which utilizes highly-enriched {sup 235}U (plus thorium) and is contained in a prismatic graphite block geometry, was used as the baseline for evaluation, but the major conclusions would not be significantly different for low- or medium-enriched {sup 235}U (without thorium) or for the German pebble-bed fuel. Future US HTGRs will be based on the Fort St. Vrain (FSV) fuel form. The whole block appears to be a satisfactory waste form for disposal in a repository and may perform better than light-water reactor (LWR) spent fuel. From the standpoint of process cost and schedule (not considering repository cost or value of fuel that might be recycled), the options are ranked as follows in order of increased cost and longer schedule to perform the option: (1) whole block, (2a) physical separation, (2b) chemical separation, and (3) complete chemical processing.

Options for treating high-temperature gas-cooled reactor fuel for repository disposal

International Nuclear Information System (INIS)

Lotts, A.L.; Bond, W.D.; Forsberg, C.W.; Glass, R.W.; Harrington, F.E.; Micheals, G.E.; Notz, K.J.; Wymer, R.G.

1992-02-01

This report describes the options that can reasonably be considered for disposal of high-temperature gas-cooled reactor (HTGR) fuel in a repository. The options include whole-block disposal, disposal with removal of graphite (either mechanically or by burning), and reprocessing of spent fuel to separate the fuel and fission products. The report summarizes what is known about the options without extensively projecting or analyzing actual performance of waste forms in a repository. The report also summarizes the processes involved in convert spent HTGR fuel into the various waste forms and projects relative schedules and costs for deployment of the various options. Fort St. Vrain Reactor fuel, which utilizes highly-enriched 235 U (plus thorium) and is contained in a prismatic graphite block geometry, was used as the baseline for evaluation, but the major conclusions would not be significantly different for low- or medium-enriched 235 U (without thorium) or for the German pebble-bed fuel. Future US HTGRs will be based on the Fort St. Vrain (FSV) fuel form. The whole block appears to be a satisfactory waste form for disposal in a repository and may perform better than light-water reactor (LWR) spent fuel. From the standpoint of process cost and schedule (not considering repository cost or value of fuel that might be recycled), the options are ranked as follows in order of increased cost and longer schedule to perform the option: (1) whole block, (2a) physical separation, (2b) chemical separation, and (3) complete chemical processing

On-site interim storage of spent nuclear fuel: Emerging public issues

International Nuclear Information System (INIS)

Feldman, D.L.; Tennessee Univ., Knoxville, TN

1992-01-01

Failure to consummate plans for a permanent repository or above- ground interim Monitored Retrievable Storage (MRS) facility for spent nuclear fuel has spurred innovative efforts to ensure at-reactor storage in an environmentally safe and secure manner. This article examines the institutional and socioeconomic impacts of Dry Cask Storage Technology (DCST)-an approach to spent fuel management that is emerging as the preferred method of on-site interim spent fuel storage by utilities that exhaust existing storage capacity

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

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

The importance of independent research and evaluation in assessing nuclear fuel cycle and waste management facility safety

International Nuclear Information System (INIS)

Downing, Walter D.; Patrick, Wesley C.; Sagar, Budhi

2009-01-01

In 1987, the United States Nuclear Regulatory Commission (NRC) established at Southwest Research Institute (SwRI) a federally funded research and development center. Known as the Center for Nuclear Waste Regulatory Analyses (CNWRA), its overall mission is to provide NRC with an independent assessment capability on technical and regulatory issues related to a potential geologic repository for spent nuclear fuel and high-level radioactive waste, as well as interim storage and other nuclear fuel-cycle facilities. For more than 20 years, the CNWRA has supported NRC through an extensive pre-licensing period of establishing the framework of regulations and guidance documents, developing computer codes and other review tools, and conducting independent laboratory, field, and numerical analyses. In June 2008, the United States Department of Energy (DOE) submitted a license application and final environmental impact statement to NRC seeking authorization to construct the nation's first geologic repository at Yucca Mountain, Nevada. The CNWRA will assist NRC in conducting a detailed technical review to critically evaluate the DOE license application to assess whether the potential repository has been designed and can be constructed and operated to safely dispose spent nuclear fuel and high-level radioactive waste. NRC access to independent, unbiased, technical advice from the CNWRA is an important aspect of the evaluation process. This paper discusses why an independent perspective is important when dealing with nuclear fuel cycle and waste management issues. It addresses practical considerations such as avoiding conflicts of interest while at the same time maintaining a world-class research program in technical areas related to the nuclear fuel cycle. It also describes an innovative approach for providing CNWRA scientists and engineers a creative outlet for professional development through an internally funded research program that is focused on future nuclear waste

ENVI Model Development for Korean Nuclear Spent Fuel Options Analysis

Energy Technology Data Exchange (ETDEWEB)

Chang, Sunyoung; Jeong, Yon Hong; Han, Jae-Jun; Lee, Aeri; Hwang, Yong-Soo [Korea Institute of Nuclear Nonproliferation and Control, Daejeon (Korea, Republic of)

2015-10-15

The disposal facility of the spent nuclear fuel will be operated from 2051. This paper presents the ENVI code developed by GoldSim Software to simulate options for managing spent nuclear fuel (SNF) in South Korea. The ENVI is a simulator to allow decision-makers to assist to evaluate the performance for spent nuclear fuel management. The multiple options for managing the spent nuclear fuel including the storage and transportation are investigated into interim storage, permanent disposal in geological repositories and overseas and domestic reprocessing. The ENVI code uses the GoldSim software to simulate the logistics of the associated activities. The result by the ENVI model not only produces the total cost to compare among the multiple options but also predict the sizes and timings of different facilities required. In order to decide the policy for spent nuclear management this purpose of this paper is to draw the optimum management plan to solve the nuclear spent fuel issue in the economical aspects. This paper is focused on the development of the ENVI's logic and calculations to simulate four options(No Reprocessing, Overseas Reprocessing, Domestic Reprocessing, and Overseas and Domestic Reprocessing) for managing the spent nuclear fuel in South Korea. The time history of the spent nuclear fuel produced from both the existing and future NPP's can be predicted, based on the Goldsim software made available very user friendly model. The simulation result will be used to suggest the strategic plans for the spent nuclear fuel management.

ENVI Model Development for Korean Nuclear Spent Fuel Options Analysis

International Nuclear Information System (INIS)

Chang, Sunyoung; Jeong, Yon Hong; Han, Jae-Jun; Lee, Aeri; Hwang, Yong-Soo

2015-01-01

The disposal facility of the spent nuclear fuel will be operated from 2051. This paper presents the ENVI code developed by GoldSim Software to simulate options for managing spent nuclear fuel (SNF) in South Korea. The ENVI is a simulator to allow decision-makers to assist to evaluate the performance for spent nuclear fuel management. The multiple options for managing the spent nuclear fuel including the storage and transportation are investigated into interim storage, permanent disposal in geological repositories and overseas and domestic reprocessing. The ENVI code uses the GoldSim software to simulate the logistics of the associated activities. The result by the ENVI model not only produces the total cost to compare among the multiple options but also predict the sizes and timings of different facilities required. In order to decide the policy for spent nuclear management this purpose of this paper is to draw the optimum management plan to solve the nuclear spent fuel issue in the economical aspects. This paper is focused on the development of the ENVI's logic and calculations to simulate four options(No Reprocessing, Overseas Reprocessing, Domestic Reprocessing, and Overseas and Domestic Reprocessing) for managing the spent nuclear fuel in South Korea. The time history of the spent nuclear fuel produced from both the existing and future NPP's can be predicted, based on the Goldsim software made available very user friendly model. The simulation result will be used to suggest the strategic plans for the spent nuclear fuel management

Concerns when designing a safeguards approach for the back-end of the Swedish nuclear fuel cycle

Energy Technology Data Exchange (ETDEWEB)

Fritzell, Anni (Uppsala Univ., Uppsala (Sweden))

2008-03-15

In Sweden, the construction of an encapsulation plant and a geological repository for the final disposal of spent nuclear fuel is planned to start within the next ten years. Due to Sweden's international agreements on non-proliferation, the Swedish safeguards regime must be extended to include these facilities. The geological repository has some unique features, which present the safeguards system with unprecedented challenges. These features include, inter alia, the long period of time that the facility will contain nuclear material and that the disposed nuclear material will be very difficult to access, implying that physical verification of its presence in the repository is not foreseen. This work presents the available techniques for creating a safeguards system for the backend of the Swedish nuclear fuel cycle. Important issues to consider in the planning and implementation of the safeguards system have been investigated, which in some cases has led to an identification of areas needing further research. The results include three proposed options for a safeguards approach, which have been evaluated on the basis of the safeguards authorities' requirements. Also, the evolution and present situation of the work carried out in connection to safeguards for geological repositories has been compiled

Fast Neutron Emission Tomography of Used Nuclear Fuel Assemblies

Science.gov (United States)

Hausladen, Paul; Iyengar, Anagha; Fabris, Lorenzo; Yang, Jinan; Hu, Jianwei; Blackston, Matthew

2017-09-01

Oak Ridge National Laboratory is developing a new capability to perform passive fast neutron emission tomography of spent nuclear fuel assemblies for the purpose of verifying their integrity for international safeguards applications. Most of the world's plutonium is contained in spent nuclear fuel, so it is desirable to detect the diversion of irradiated fuel rods from an assembly prior to its transfer to ``difficult to access'' storage, such as a dry cask or permanent repository, where re-verification is practically impossible. Nuclear fuel assemblies typically consist of an array of fuel rods that, depending on exposure in the reactor and consequent ingrowth of 244Cm, are spontaneous sources of as many as 109 neutrons s-1. Neutron emission tomography uses collimation to isolate neutron activity along ``lines of response'' through the assembly and, by combining many collimated views through the object, mathematically extracts the neutron emission from each fuel rod. This technique, by combining the use of fast neutrons -which can penetrate the entire fuel assembly -and computed tomography, is capable of detecting vacancies or substitutions of individual fuel rods. This paper will report on the physics design and component testing of the imaging system. This material is based upon work supported by the U.S. Department of Energy, Office of Defense Nuclear Nonproliferation Research and Development within the National Nuclear Security Administration, under Contract Number DE-AC05-00OR22725.

Radioactive waste repository study

International Nuclear Information System (INIS)

1978-11-01

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

Managing Spent Nuclear Fuel at the Idaho National Laboratory

Energy Technology Data Exchange (ETDEWEB)

Thomas Hill; Denzel L. Fillmore

2005-10-01

The Idaho National Laboratory (INL) has a large inventory of diverse types of spent nuclear fuel (SNF). This legacy derives from the history of the INL as the National Reactor Testing Station, and from its mission to recover HEU from SNF and to test and examine SNF after irradiation. The INL also has a large diversity of SNF storage facilities, some 50 years old. SNF at INL has many forms—from intact assemblies down to metallurgical mounts, and some fuel has been wet stored for over 40 years. SNF is stored bare or in metal cans under water, or dry in vaults, caissons or casks. Inspection shows varying corrosion and degradation of the SNF and its storage cans. SNF has been stored in 10 different facilities: 5 pools, one cask storage pad, one vault, two generations of caisson facilities, and one modular Independent Spent Fuel Storage Installation (ISFSI). The pools range in age from 40 years old to the most modern in the US Department of Energy (DOE) complex. The near-term objective is to move SNF from older pools to interim dry storage, allowing shutdown and decommissioning of the older facilities. This move involves drying methods that are dependent on fuel type. The long-term objective is to have INL SNF in safe dry storage and ready to be shipped to the National Repository. The unique features of the INL SNF requires special treatments and packaging to meet the proposed repository acceptance criteria and SNF will be repackaged in standardized canisters for shipment and disposal in the National Repository. Disposal will use the standardized canisters that can be co-disposed with High Level Waste glass logs to limit the total fissile material in a repository waste package. The DOE standardized canister also simplifies the repository handling of the multitude of DOE SNF sizes and shapes.

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

Overweight truck shipments to nuclear waste repositories: legal, political, administrative and operational considerations

International Nuclear Information System (INIS)

1986-03-01

This report, prepared for the Chicago Operations Office and the Office of Civilian Radioactive Waste Management (OCRWM) of the US Department of Energy (DOE), identifies and analyzes legal, political, administrative, and operational issues that could affect an OCRWM decision to develop an overweight truck cask fleet for the commercial nuclear waste repository program. It also provides information required by DOE on vehicle size-and-weight administration and regulation, pertinent to nuclear waste shipments. Current legal-weight truck casks have a payload of one pressurized-water reactor spent fuel element or two boiling-water reactor spent fuel elements (1 PWR/2 BWR). For the requirements of the 1960s and 1970s, casks were designed with massive shielding to accommodate 6-month-old spent fuel; the gross vehicle weight was limited to 73,280 pounds. Spent fuel to be moved in the 1990s will have aged five years or more. Gross vehicle weight limitation for the Interstate highway system has been increased to 80,000 pounds. These changes allow the design of 25-ton legal-weight truck casks with payloads of 2 PWR/5 BWR. These changes may also allow the development of a 40-ton overweight truck cask with a payload of 4 PWR/10 BWR. Such overweight casks will result in significantly fewer highway shipments compared with legal-weight casks, with potential reductions in transport-related repository risks and costs. These advantages must be weighed against a number of institutional issues surrounding such overweight shipments before a substantial commitment is made to develop an overweight truck cask fleet. This report discusses these issues in detail and provides recommended actions to DOE

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.

Role of mine ventilation in site selection for a nuclear waste repository

International Nuclear Information System (INIS)

McPherson, M.J.

1984-01-01

The application of mine ventilation practice and theory to the measurement of groundwater flow for the purpose of the selection of sites for underground storage of nuclear spent fuel is described. The discipline of mine ventilation has an important part to play not only in the design and operation of an underground nuclear waste repository but also during the early stages of potential site characterization. One of the most vital factors in the selection of a suitable site is the rate at which groundwater can flow through the native rock. The effects of repository heat on groundwater migration are highlighted and a description of a major experiment in an underground test site is included. Detailed monitoring of airflow and its psychrometric properties enabled quantification of very low rates of water seepage into an isolated heading. The results indicated the relationship between permeability of a fractured rock and temperature. The transient phenomena that govern evaporation of water from fissured rock surfaces in the test chamber are also examined. (author)

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

State-of-the-art Report on Innovative Fuels for Advanced Nuclear Systems

International Nuclear Information System (INIS)

Chauvin, N.; Minato, K.; Ogata, T.; Lee, C.B.; Pouchon, M.A.; Pasamehmetoglu, K.O.; Choi, Y.J.; Kennedy, J.R.; Massara, S.; Cornet, S.; ); Sommers, J.; ); McClellan, K.

2014-01-01

Development of innovative fuels such as homogeneous and heterogeneous fuels, ADS fuels, and oxide, metal, nitride and carbide fuels is an important stage in the implementation process of advanced nuclear systems. Several national and international R and D programmes are investigating minor actinide-bearing fuels due to their ability to help reduce the radiotoxicity of spent fuel and therefore decrease the burden on geological repositories. Minor actinides can be converted into a suitable fuel form for irradiation in reactor systems where they are transmuted into fission products with a significantly shorter half-life. This report compares recent studies of fuels containing minor actinides for use in advanced nuclear systems. The studies review different fuels for several types of advanced reactors by examining various technical issues associated with fabrication, characterisation, irradiation performance, design and safety criteria, as well as technical maturity. (authors)

Integrated scheme of long-term for spent fuel management of power nuclear reactors

International Nuclear Information System (INIS)

Ramirez S, J. R.; Palacios H, J. C.; Martinez C, E.

2015-09-01

After of irradiation of the nuclear fuel in the reactor core, is necessary to store it for their cooling in the fuel pools of the reactor. This is the first step in a processes series before the fuel can reach its final destination. Until now there are two options that are most commonly accepted for the end of the nuclear fuel cycle, one is the open nuclear fuel cycle, requiring a deep geological repository for the fuel final disposal. The other option is the fuel reprocessing to extract the plutonium and uranium as valuable materials that remaining in the spent fuel. In this study the alternatives for the final part of the fuel cycle, which involves the recycling of plutonium and the minor actinides in the same reactor that generated them are shown. The results shown that this is possible in a thermal reactor and that there are significant reductions in actinides if they are recycled into reactor fuel. (Author)

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

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)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

International Nuclear Information System (INIS)

2012-12-01

Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

Safety case for the disposal of spent nuclear fuel at Olkiluoto. Complementary considerations 2012

Energy Technology Data Exchange (ETDEWEB)

NONE

2012-12-15

Complementary Considerations sits within Posiva Oy's Safety Case 'TURVA-2012' report portfolio and has the objective of enhancing confidence in the outcomes of the safety assessment for a spent nuclear fuel repository to be constructed at Olkiluoto, Finland. The main emphasis in this report is on the evidence and understanding that can be gained from observations at the site, including its regional geological environment, and from natural and anthropogenic analogues for the repository, its components and the processes that affect safety. In particular, the report addresses diverse and less quantifiable types of evidence and arguments that are enclosed to enhance confidence in the outcome of the safety assessment. These complementary considerations have been described as evaluations, evidence and qualitative supporting arguments that lie outside the scope of the other reports of the quantitative safety assessment. The experience with natural analogues for the long-term durability of the materials involved and the extent of processes provides high confidence in our understanding of the disposal system and its evolution. For each engineered barrier and key process, there is increasing analogue evidence to support the conceptual models and parameters. Regarding the suitability of the Olkiluoto site to host a spent fuel repository, a number of factors have been identified that indicate the suitability of crystalline host rock in general, and that of the Olkiluoto site in particular. The report also provides radiation background information for the use of complementary indicators, which aid in putting the results of the safety analysis presented in Assessment of Radionuclide Release Scenarios for the Repository System and Biosphere Assessment in a broader perspective to show that the radiation originating from a spent nuclear fuel repository remains in most cases much below natural background radiation or that caused by non-nuclear industries. (orig.)

International high-level radioactive waste repositories

International Nuclear Information System (INIS)

Lin, W.

1996-01-01

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

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

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

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

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

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.

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

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

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

Modelling of the THM-evolution of Olkiluoto nuclear waste repository

International Nuclear Information System (INIS)

Toprak, Erdem; Olivella, Sebastia; Mokni, Nadia; Pintado, Xavier

2012-01-01

Document available in extended abstract form only. This paper presents preliminary analyses of coupled Thermo-Hydro-Mechanical (THM) processes in the future nuclear waste repository in Olkiluoto (www.posiva.fi). A finite element program Code-Bright is used to perform modeling calculations of disposal tunnels in an underground repository for spent nuclear fuel. The repository will consist of a series of deposition holes in the bedrock. Bentonite buffer rings will surround the copper canisters containing spent fuel. As a protecting and isolating barrier between the waste canisters and the surrounding host rock, MX80 bentonite will be used as buffer material. Friedland clay is considered one of the best candidates to be used as drift backfill material to meet the long-term performance requirements set for backfilling of a disposal tunnel in the repository. Figure 1 shows a cross section of the spent nuclear final disposal facility. The time required for reaching full saturation, maximum temperature reached in canister, deformations in the buffer-backfill interface and stress-deformation balance in this interaction and also modeling of gap between canister and buffer ring are the main issued addressed of this study. A fundamental issue in modeling was to determine relevant thermal boundary conditions so that the details of THM-behavior could be captured by defining proper near-field thermal boundaries. In this study, it has been shown that temperature on the considered close boundaries depends on initial canister power, fuel power decay characteristic and rock thermal properties. The thermal boundary conditions fixed at the THM modeling have been calculated solving the thermal problem for the entire repository with the analytical solution (Ikonen, 2005). With regard to the hydraulic analyses, the time required for full saturation is sensitive to vapor diffusion, hydraulic conductivity and water retention curve of the buffer and the hydraulic conductivity of the rock. A

Comparison of Tagging Technologies for Safeguards of Copper Canisters for Nuclear Spent Fuel.

Science.gov (United States)

Clementi, Chiara; Littmann, François; Capineri, Lorenzo

2018-03-21

Several countries are planning to store nuclear spent fuel in long term geological repositories, preserved by copper canisters with an iron insert. This new approach involves many challenging problems and one is to satisfy safeguards requirements: the Continuity of Knowledge (CoK) of the fuel must be kept from the encapsulation plant up to the final repository. To date, no measurement system has been suggested for a unique identification and authentication. Following the list of the most important safeguards, safety and security requirements for copper canisters identification and authentication, a review of conventional tagging technologies and measurement systems for nuclear items is reported in this paper. The aim of this study is to verify to what extent each technology could be potentially used for keeping the CoK of copper canisters. Several tagging methods are briefly described and compared, discussing advantages and disadvantages.

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.)

A Strategy for Describing the Biosphere at Candidate Sites for Repositories of Nuclear Waste: Linking Ecosystem and Landscape Modeling

International Nuclear Information System (INIS)

Lindborg, Tobias; Loefgren, Anders; Soederbaeck, Bjoern; Kautsky, Ulrik; Lindborg, Regina; Bradshaw, Clare

2006-01-01

To provide information necessary for a license application for a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Co. has started site investigations at two sites in Sweden. In this paper, we present a strategy to integrate site-specific ecosystem data into spatially explicit models needed for safety assessment studies and the environmental impact assessment. The site-specific description of ecosystems is developed by building discipline-specific models from primary data and by identifying interactions and stocks and flows of matter among functional units at the sites. The conceptual model is a helpful initial tool for defining properties needed to quantify system processes, which may reveal new interfaces between disciplines, providing a variety of new opportunities to enhance the understanding of the linkages between ecosystem characteristics and the functional properties of landscapes. This type of integrated ecosystem-landscape characterization model has an important role in forming the implementation of a safety assessment for a deep repository

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

Initial performance assessment of the disposal of spent nuclear fuel and high-level waste stored at Idaho National Engineering Laboratory

International Nuclear Information System (INIS)

Rechard, R.P.

1993-12-01

This performance assessment characterized plausible treatment options conceived by the Idaho National Engineering Laboratory (INEL) for its spent fuel and high-level radioactive waste and then modeled the performance of the resulting waste forms in two hypothetical, deep, geologic repositories: one in bedded salt and the other in granite. The results of the performance assessment are intended to help guide INEL in its study of how to prepare wastes and spent fuel for eventual permanent disposal. This assessment was part of the Waste Management Technology Development Program designed to help the US Department of Energy develop and demonstrate the capability to dispose of its nuclear waste, as mandated by the Nuclear Waste Policy Act of 1982. The waste forms comprised about 700 metric tons of initial heavy metal (or equivalent units) stored at the INEL: graphite spent fuel, experimental low enriched and highly enriched spent fuel, and high-level waste generated during reprocessing of some spent fuel. Five different waste treatment options were studied; in the analysis, the options and resulting waste forms were analyzed separately and in combination as five waste disposal groups. When the waste forms were studied in combination, the repository was assumed to also contain vitrified high-level waste from three DOE sites for a common basis of comparison and to simulate the impact of the INEL waste forms on a moderate-sized repository, The performance of the waste form was assessed within the context of a whole disposal system, using the U.S. Environmental Protection Agency's Environmental Radiation Protection Standards for Management and Disposal of Spent Nuclear Fuel, High-Level and Transuranic Radioactive Wastes, 40 CFR 191, promulgated in 1985. Though the waste form behavior depended upon the repository type, all current and proposed waste forms provided acceptable behavior in the salt and granite repositories

Evolution of spent nuclear fuel in dry storage conditions for millennia and beyond

Energy Technology Data Exchange (ETDEWEB)

Wiss, Thierry, E-mail: thierry.wiss@ec.europa.eu [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Hiernaut, Jean-Pol [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Roudil, Danièle [Commissariat à l’Energie Atomique et aux Energie Alternatives, Centre de Marcoule, BP 30207 Bagnols-sur-Cèze (France); Colle, Jean-Yves; Maugeri, Emilio; Talip, Zeynep; Janssen, Arne; Rondinella, Vincenzo; Konings, Rudy J.M.; Matzke, Hans-Joachim [European Commission, Joint Research Centre, Institute for Transuranium Elements, P.O. Box 2340, 76125 Karlsruhe (Germany); Weber, William J. [Department of Materials Science and Engineering, The University of Tennessee, Knoxville, TN 37996 (United States); Division of Materials Science and Technology, Oak Ridge National Laboratory, Oak Ridge, TN 37831 (United States)

2014-08-01

Significant amounts of spent uranium dioxide nuclear fuel are accumulating worldwide from decades of commercial nuclear power production. While such spent fuel is intended to be reprocessed or disposed in geologic repositories, out-of-reactor radiation damage from alpha decay can be detrimental to its structural stability. Here we report on an experimental study in which radiation damage in plutonium dioxide, uranium dioxide samples doped with short-lived alpha-emitters and urano-thorianite minerals have been characterized by XRD, transmission electron microscopy, thermal desorption spectrometry and hardness measurements to assess the long-term stability of spent nuclear fuel to substantial alpha-decay doses. Defect accumulation is predicted to result in swelling of the atomic structure and decrease in fracture toughness; whereas, the accumulation of helium will produce bubbles that result in much larger gaseous-induced swelling that substantially increases the stresses in the constrained spent fuel. Based on these results, the radiation-ageing of highly-aged spent nuclear fuel over more than 10,000 years is predicted.

Wet storage of nuclear spent fuel from nuclear research reactor WWR-S

International Nuclear Information System (INIS)

Dragolici, A. C; Zorliu, A.; Petran, C.; Mincu, I.

2001-01-01

Nuclear research reactor WWR-S of IFIN-HH was commissioned on 29 July 1957 and shut down on December 1997. Now it is in Conservation State. During 40 years , the reactor was operated about 150,000 hours at variable power level ranging within 5 W and 3500 kW, and producing a total power of 9,510 MWday. After 20 years of operation a large number of spent fuel elements became available for storage exceeding the stocking capacity of the small cooling pond near reactor. Therefore, in 1980 the nuclear spent fuel repository was commissioned that contains at present all the fuel elements burnt in the reactor during years, minus 51 S-36 fuel assemblies which are conserved in the cooling pond. This repository contains 4 identical ponds, each of them having the storage capacity of 60 fuel assemblies. Every pond having the outer sizes of 2,750 mm (length) x 900 mm (breadth) x 5,700 mm (depth), is made from a special aluminum alloy (AlMg 3 ), with the walls thickness of 10 mm and bottom thickness of 15 mm. Pond's lids are made of cast iron having the thickness of 500 mm; they provide only the biological protection for the maintenance personnel. A 1.5 m concrete layer ensures the biological protection of the ponds. Over the fuel elements in every pond a 4.5 m water layer is provided, playing the role of biological protection and coolant. Inside the ponds exists an aluminum rack, which contains 60 locations for fuel storage. The spacing between these locations was determined from considerations of criticality and it is was the same with that of the cooling pond near the reactor. To have supplementary protection in the case of an accident which can destroy the entire rack and put together all the fuel elements thus forming critical mass, cadmium plates were placed on the ponds bottom for a better neutron absorption. Exploitation of cooling pond near the WWR-S reactor which has the identical structure with that of nuclear spent fuel repository, demonstrate the reliability and

British Nuclear Fuels PLC: report and accounts 1989-90

International Nuclear Information System (INIS)

1991-01-01

Members of the Energy Select Committee put questions to representatives of British Nuclear Fuels PLC (BNFL) about the annual report and accounts 1989-90. Questions concerned the late publication of the accounts, BNFLs role in the downfall of the nuclear privatisation, government assistance to the nuclear industry, the price BNFL charges for fuel reprocessing and the process of laser isotope separation of uranium. The committee also asked about the rate of return in BNFL's assets as a percentage, Sellafield's potential as a site for a deep repository for radioactive wastes and the 6000 boreholes that MREX will drill at Sellafield. The commercial case for reprocessing is made. Feasibility studies for possible new reactions at Sellafield and Chapel Cross have been carried out. On the whole the Energy Committee were satisfied with the replies from BNFL. (UK)

Report on the current situation with regard to nuclear fuel and the operations of Svensk Kaernbraenslefoersoerjning AB

International Nuclear Information System (INIS)

1982-11-01

The cost of supplying nuclear fuel, including the reserve stockpile, has averaged about SEK 0.033/kWhe during the report period. Within the sea transportation system, the ship m/s Sigyn was delivered during the month of October. The temporary storage facility for spent fuel, CLAB, is scheduled to be completed at Simpevarp at the beginning of 1985. Licensing applications have been submitted to the appropriate authorities for the construction of a final repository for reactor waste (SFR) in an underground facility to be built in the rock adjacent to the Forsmark nuclear power station. The first outbound shipment from Ringhals under the reprocessing contract between SKBF and COGEMA of France is planned to take place around the start of 1983. Reprocessing will commence in 1985 at the earliest. The uranium (approx. 850 tonnes) and plutonium (approx. 6 tonnes) obtained from reprocessing is Swedish property. Broad and long-range research is currently being conducted in order to further refine the technology and select a site for the final repository, SFL. Efforts are now being concentrated on the final storage of spent fuel without reprocessing. Construction of the repository is scheduled to start in 2010 and operation in 2020. SKBF has been entrusted with the management of the international Stripa project. Pursuant to the new Financing Act, SKBF submitted a report on 30 June of this year to the National Board for Spent Nuclear Fuel (NAK). The report included a cost estimate in 1981 prices for the management and various stages in the back end of the nuclear fuel cycle. The estimate, comes out to SEK 32 billion, which represents about 10percent of the value of the electrical power produced by the nuclear power plants. The Government has decided upon a rate of SEK 0.017/kWhe of electricity generated by nuclear power as the 1982 charge to be paid to the state (NAK). The total cost picture for nuclear fuel (including provision for the costs of decommissioning of nuclear power

Radioactive waste repository study

International Nuclear Information System (INIS)

1978-11-01

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

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

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

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)

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)

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.

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

Impact of partitioning and transmutation on repository design

International Nuclear Information System (INIS)

Carter, D. 'Buzz' Savage

2004-01-01

The U.S. Department of Energy's Advanced Fuel Cycle Initiative (AFCI) program is investigating spent nuclear fuel treatment technologies that have the potential to improve the performance of the proposed geologic repository at Yucca Mountain. Separating actinides and selected fission products from spent fuel, storing some of them as low level waste and transmuting them in thermal and/or fast reactors has the potential to reduce the volume, short and long-term heat load and radiotoxicity of the high level waste destined for the repository, effectively increasing its capacity by a factor of 50 or more above the current legislative limit. (author)

Accelerator assisted repositories, technical issue identification and economic assessment

Energy Technology Data Exchange (ETDEWEB)

Myers, T.; Favale, A.; Berwald, D. [Northrop Grumman Corp., Bethpage, NY (United States)

1995-12-31

An investigation (technical and economic) is presented to quantify the impact of accelerator assisted repository (AAR) system on the US national nuclear repository strategy. An overview of US spent fuel policy is presented which provides a means to comparatively assess competing spent fuel disposition technologies under investigation. The advantages of an AAR system are highlighted and discussed. A companion economic analysis is presented. The results indicate that although a US geologic waste repository will continue to be required, waste partitioning and accelerator transmutation of selected actinides, and long-lived fission products, can result in substantial benefits. (author) 18 refs.

Instant release fraction corrosion studies of commercial UO2 BWR spent nuclear fuel

Science.gov (United States)

Martínez-Torrents, Albert; Serrano-Purroy, Daniel; Sureda, Rosa; Casas, Ignasi; de Pablo, Joan

2017-05-01

The instant release fraction of a spent nuclear fuel is a matter of concern in the performance assessment of a deep geological repository since it increases the radiological risk. Corrosion studies of two different spent nuclear fuels were performed using bicarbonate water under oxidizing conditions to study their instant release fraction. From each fuel, cladded segments and powder samples obtained at different radial positions were used. The results were normalised using the specific surface area to permit a comparison between fuels and samples. Different radionuclide dissolution patterns were studied in terms of water contact availability and radial distribution in the spent nuclear fuel. The relationship between the results of this work and morphological parameters like the grain size or irradiation parameters such as the burn-up or the linear power density was studied in order to increase the understanding of the instant release fraction formation.

Implementing adaptive phased management (APM) for Canada's used nuclear fuel

International Nuclear Information System (INIS)

King, F.

2008-01-01

This paper discusses the implementation of Adaptive Phased Management (APM) for Canada's used nuclear fuel. APM is a combination of technology and management system. The technology involves centralized containment and isolation in deep geological repository in a suitable rock formation, as well as shallow storage where used fuel remains retrievable. In both cases there is continuous monitoring. The management system consists of public engagement, phased decision-making, continuous learning and adaption, open and inclusive. Finally, it involves seeking an in formed willing host community

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

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

International Nuclear Information System (INIS)

2012-01-01

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

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

Building world-wide nuclear industry success stories - Safe management of nuclear waste and used nuclear fuel

International Nuclear Information System (INIS)

Saint-Pierre, S.

2005-01-01

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 fulfil its obligation with professional dedication and technological skill. (author)

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)

Management of radioactive wastes from nuclear fuels and power plants in Canada

International Nuclear Information System (INIS)

Tomlinson, M.; Mayman, S.A.; Tammemagi, H.Y.; Gale, J.; Sanford, B.; Dyne, P.J.

1977-01-01

The nature of Canadian nuclear fuel and nuclear generating plant radioactive wastes are summarized. Full exploitation of fission energy resources entails recovery of all fissile and fertile material from spent fuel and separating the fission products as wastes for disposal. A plan for final disposal of all the radioactive wastes is a key component of the waste management scheme. Principles of a scheme for safe, responsible disposal of long-lived radioactive wastes deep underground in isolation from man and the biosphere are outlined. The status of the development and construction program is indicated. We plan to select a site in either a hard rock formation or in a suitable salt bed by 1981 so that a repository can be constructed to begin a demonstration phase in 1986. The repository is to be capable of eventual expansion to accomodate all Canadian nuclear wastes to at least 2050 when in full-scale operation. Extensive geotechnical studies have been initiated in order to select a site, and design and test the repository. We have demonstrated incorporation of fission products in solids that in the short term (17 years) dissolve more slowly than plutonium decays. Investigations of long-term stability are in hand. The principle of retardation of migration of fission products, so that they decay before surfacing, has been tested. Additional capacity for storage of used fuel prior to reprocessing and disposal is required by 1986 and a preliminary design has been prepared for a pool facility to be located at a central fuel recycling and disposal complex. A demonstration of dry storage of fuel in concrete containers is in progress. The quantities of CANDU generating-station wastes and the principles and methods for managing them are summarized. Methods for volume reduction and immobilization by solidification are well advanced. A radioactive-waste operations site is being developed with several different types of surface storage, each with multiple barriers against

Management of radioactive wastes from nuclear fuels and power plants in Canada

International Nuclear Information System (INIS)

Tomlinson, M.; Mayman, S.A.; Tammemagi, H.Y.; Gale, J.; Sanford, B.

1977-01-01

The nature of Canadian nuclear fuel and nuclear generating plant radioactive wastes is summarized. Full exploitation of fission energy resources entails recovery of all fissile and fertile material from spent fuel and separating the fission products as wastes for disposal. A plan for final disposal of all the radioactive wastes is a key component of the waste management scheme. Principles of a scheme for safe, responsible disposal of long-lived radioactive wastes deep underground, in isolation from man and the biosphere, are outlined. The status of the development and construction programme is indicated. It is planned to select a site in either a hard rock formation or in a suitable salt bed by 1981 so that a repository can be constructed to begin a demonstration phase in 1986. The repository is to be capable of eventual expansion to accomodate all Canadian nuclear wastes to at least 2050 when in full-scale operation. Extensive geotechnical studies have been initiated in order to select a site, and design and test the repository. The incorporation of fission products in solids that in the short term (17 years) dissolve more slowly than plutonium decays has been demonstrated. Investigations of long-term stability are in hand. The principle of retardation of migration of fission products, so that they decay before surfacing, has been tested. Additional capacity for storage of used fuel prior to reprocessing and disposal is required by 1986 and a preliminary design has been prepared for a pool facility to be located at a central fuel recycling and disposal complex. A demonstration of dry storage of fuel in concrete containers is in progress. The quantities of CANDU generating-station wastes and the principles and methods for managing them are summarized. Methods for volume reduction and immobilization by solidification are well advanced. A radioactive-waste operations site is being developed with several different types of surface storage, each with multiple barriers

Final disposal of spent fuels and high activity waste: the European model for a shared regional repository. Part 3

International Nuclear Information System (INIS)

Herscovich de Pahissa, Marta

2009-01-01

Geological disposal is a essential element and the only available approach to the management strategy for spent nuclear fuel and high level radioactive waste from reprocessing and also for other long-lived waste from nuclear technology applications. It is technically feasible and offers the required long term safety. The growth of existing nuclear programmes and the expansion of nuclear technology to new countries will have effects on the fuel cycle because of the increased concern on proliferation and waste management. The crucial task is to ensure that all countries that use nuclear energy now or will do it in the future, have defined and agreed safety and security standards for all facilities and a credible waste disposal strategy , accepted by the community, when this become necessary. Multinational cooperation on essential aspects of fuel cycle, particularly the geological disposal, is required for several countries with relatively small nuclear energy programmes or small quantities of radioactive waste. For these countries, that can be in different stages of development, the possibility to share a deep geological repository could be convenient. The European Union SAPIERR project is described in this paper as an example of a regional multinational cooperation. (author) [es

Dynamic analysis of Korean nuclear fuel cycle with fast reactor systems

International Nuclear Information System (INIS)

Jeong, Chang Joon

2004-12-01

The Korean nuclear fuel cycle scenario was analyzed by the dynamic analysis method, including Pressurized Water Reactor (PWR), Canadian Deuterium Uranium (CANDU) and fast reactor systems. For the once-through fuel cycle model, the existing nuclear power plant construction plan was considered up to 2016, while the nuclear demand growth rate from the year 2016 was assumed to be 1%. After setting up the once-through fuel cycle model, the Korea Advanced Liquid Metal Reactor (KALIMER) scenario was modeled to investigate the fuel cycle parameters. For the analysis of the fast reactor fuel cycle, both KAILMER-150 and KALIMER-600 reactors were considered. In this analysis, the spent fuel inventory as well as the amount of plutonium, Minor Actinides (MA) and Fission Products (FP) of the recycling fuel cycle was estimated and compared to that of the once-through fuel cycle. Results of the once-through fuel cycle calculation showed that the demand grows up to 64 GWe and total amount of spent fuel would be ∼102 kt in 2100. If the KALIMER scenario is implemented, the total spent fuel inventory can be reduced by ∼80%. However it was found that the KALIMER scenario does not contribute to reduce the amount of MA and FP, which is important when designing a repository. For the further destruction of MA, an actinide burner can be considered in the future nuclear fuel cycle

Nuclear fuel cycle synergies and regional scenarios for Europe

International Nuclear Information System (INIS)

Salvadores, M.; Romanello, V.; Schwenk-Ferrero, A.; Boucher, L.; Meyer, M.

2009-01-01

Regional strategies can provide a useful framework for implementing innovative nuclear fuel cycles. The appropriate sharing of efforts and facilities among different countries is necessary in today's context, as is taking into account proliferation concerns and resource optimisation. The preliminary studies examined in this report show that the expected benefits deriving from partitioning and transmutation (P and T), notably the reduction of radiotoxicity and heat load in a shared repository, can bring advantages to all countries of the region concerned, even when different nuclear energy policies are pursued. The studies also demonstrate that regional strategies tend to favour a nuclear renaissance in some countries. A regional approach is proposed in order to implement the innovative fuel cycles associated with partitioning and transmutation in Europe. The impact of different deployment strategies and policies in various countries is addressed. Regional facilities characteristics and potential deployment schedules are also discussed. Further studies should be undertaken to investigate practical issues (fuel transport in particular) and institutional issues which will, without doubt, be very challenging. (authors)

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

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

Comparison of risks due to HLW and SURF repositories in bedded salt

International Nuclear Information System (INIS)

Chu, M.S.Y.; Ortiz, N.R.; Wahi, K.K.

1983-01-01

A methodology was developed for use in the analysis of risks from geologic disposal of nuclear wastes. This methodology is applied to two conceptual nuclear waste repositories in bedded salt containing High-Level Waste (HLW) and Spent Un-Reprocessed Fuel (SURF), respectively. A comparison of the risk estimated from the HLW and SURF repositories is presented

National Option of China's Nuclear Energy Systems for Spent Fuel Management

Energy Technology Data Exchange (ETDEWEB)

Gao, R.X. [University of Science and Technology, Daejeon (Korea, Republic of); Ko, W. I.; Lee, S. H. [Korea Atomic Energy Research Institute, Daejeon (Korea, Republic of)

2015-10-15

Along with safety concerns, these long standing environmental challenges are the major factors influencing the public acceptance of nuclear power. Although nuclear power plays an important role in reducing carbon emissions from energy generation, this could not fully prove it as a sustainable energy source unless we find a consensus approach to treat the nuclear wastes. There are currently no countries that have completed a whole nuclear fuel cycle, and the relative comparison of the reprocessing spent fuel options versus direct disposal option is always a controversial issue. Without exception, nowadays, China is implementing many R and D projects on spent fuel management to find a long-term solution for nuclear fuel cycle system transition, such as deep geological repositories for High Level Waste (HLW), Pu Reduction by Solvent Extraction (PUREX) technology, and fast reactor recycling Mixed U-Pu Oxide (MOX) fuels, etc. This paper integrates the current nation's projects of back-end fuel cycle, analyzes the consequences of potential successes, failures and delays in the project development to future nuclear fuel cycle transition up to 2100. We compared the dynamic results of four scenarios and then assessed relative impact on spent fuel management. The result revealed that the fuel cycle transition of reprocessing and recycling of spent fuel would bring advantages to overall nuclear systems by reducing high level waste inventory, saving natural uranium resources, and reducing plutonium management risk.

What are Spent Nuclear Fuel and High-Level Radioactive Waste?

International Nuclear Information System (INIS)

2002-01-01

Spent nuclear fuel and high-level radioactive waste are materials from nuclear power plants and government defense programs. These materials contain highly radioactive elements, such as cesium, strontium, technetium, and neptunium. Some of these elements will remain radioactive for a few years, while others will be radioactive for millions of years. Exposure to such radioactive materials can cause human health problems. Scientists worldwide agree that the safest way to manage these materials is to dispose of them deep underground in what is called a geologic repository

The economics of the back end of the nuclear fuel cycle

International Nuclear Information System (INIS)

Cameron, Ron; Urso, Maria Elena; Lokhov, Alexey

2014-01-01

Spent nuclear fuel and high-level waste from the fuel cycle of commercial nuclear power plants represent a small proportion of the radioactive waste produced globally by various industries (including medicine, agriculture and research), but they account for the greatest radioactivity content and longevity. While technologies are well developed and widely employed for the treatment and disposal of the much larger volumes of less radioactive low-level and short-lived intermediate-level waste, no final disposal facilities have yet been fully implemented for spent nuclear fuel (SNF) and high-level waste (HLW). A lack of experience in the construction and operation of deep geological repositories, combined with the extensive periods required for the implementation of back-end solutions, have thus contributed to growing uncertainties about the costs associated with managing SNF and HLW. The issue has become a central challenge for the nuclear industry and a matter of public concern and debate. Using official data supplied by national authorities, a descriptive overview [1] was developed of general principles and frameworks for the long-term management of SNF, current national policies and practices, as well as available and prospective technology options, including: - Direct disposal, where the fuel is used once and then regarded as waste for disposal. - Partial recycling, where the spent fuel is reprocessed to recover unused uranium and plutonium for recycling in light water reactors (LWRs). Once irradiated, the recycled fuel bundles can be either stored (with the perspective of their reprocessing and recycling in future fast reactors - FRs) or disposed of after encapsulation. - Advanced systems and fuel cycle concepts for the longer-term future, studied theoretically or on a pilot scale, with the dual objective of reducing the mass and radioactivity of waste destined to final disposal and optimising the use of natural resources. In addition, a cost analysis of these

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

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

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

Spent nuclear fuel storage: Legal, technical and political considerations

International Nuclear Information System (INIS)

Blake, E.L. Jr.; Buren, M.A.

1994-01-01

In 1982, Congress enacted the Nuclear Waste Policy Act (NWPA), assigning responsibility to the Department of Energy (DOE) for the development and implementation of a comprehensive national nuclear waste management program. The NWPA makes clear that the generators and owners of commercially-generated spent nuclear fuel (SNF) have the primary responsibility to provide for, and pay the costs of, the interim storage of such SNF until it is accepted by the DOE under the provisions of the NWPA. The shift in responsibility was expected to begin in 1998, the date specified in the NWPA and the DOE's contracts with the utilities, at which time the NWPA anticipated commencement of operations of a geologic repository and/or a monitored retrievable storage facility (MRS). Unfortunately, despite a mid-course correction to the NWPA mandated by Congress in 1987 in an effort to streamline and accelerate the program, DOE is way behind schedule. DOE's last published program schedule indicates the commencement of repository operations in 2010, a date many feel is overly optimistic. In repeated statements during the early 1990s, DOE sought to reassure utility companies and their regulatory commissions that it could still commence SNF acceptance in 1998 for storage at an MRS if such a facility were sited through a voluntary process by the end of 1992. That date has now come and gone. Although DOE is still nominally seeking a voluntary MRS host jurisdiction, the prospects for MRS operation by 1998 are dim. Putting aside for the moment the question of DOE's ability to bring the repository on line, the immediate problem facing domestic utilities is the need to augment their onsite SNF storage capacity. In addition to providing a brief overview of the Federal independent spent fuel storage installation (ISFSI) licensing process, the author provides some insight of what the real issues are in ISFSI licensing

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

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)

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

International Nuclear Information System (INIS)

1999-01-01

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

Actions for continued safe wet storage of spent nuclear fuel at VVR-S reactor in Bucharest-Magurele

International Nuclear Information System (INIS)

Isbasescu, M.; Zorliu, A.; Silviu-laurentiu, B.; Stefan, V. . E-mail address of corresponding author: mirifa@ifin.nipne.ro; Isbasescu, M.)

2005-01-01

The Romanian VVR-S research reactor is located 8 kilometers from Bucharest in the town of Magurele and was operated by the Horia Hulubei National Institute of Physics and Nuclear Engineering (IFIN-HH). The reactor first reached criticality in July 1957 and operated until December 1997 when it was permanently shutdown. The VVR - S reactor of IFIN has two repositories for spent fuel elements: (1) Cooling pool located in the reactor room; (2) Long-term repositories located outside the reactor building - SNFW (spent nuclear fuel warehouse). The major factors believed to influence the pitting of aluminium alloys are conductivity, pH, and bicarbonate, chloride, sulphate and oxygen content. Some of these parameters have been analyzed at SNFW-IFIN-HH. (author)

Sorption of strontium on uranyl peroxide: implications for a high-level nuclear waste repository.

Science.gov (United States)

Sureda, Rosa; Martínez-Lladó, Xavier; Rovira, Miquel; de Pablo, Joan; Casas, Ignasi; Giménez, Javier

2010-09-15

Strontium-90 is considered the most important radioactive isotope in the environment and one of the most frequently occurring radionuclides in groundwaters at nuclear facilities. The uranyl peroxide studtite (UO2O2 . 4H2O) has been observed to be formed in spent nuclear fuel leaching experiments and seems to have a relatively high sorption capacity for some radionuclides. In this work, the sorption of strontium onto studtite is studied as a function of time, strontium concentration in solution and pH. The main results obtained are (a) sorption is relatively fast although slower than for cesium; (b) strontium seems to be sorbed via a monolayer coverage of the studtite surface, (c) sorption has a strong dependence on ionic strength, is negligible at acidic pH, and increases at neutral to alkaline pH (almost 100% of the strontium in solution is sorbed above pH 10). These results point to uranium secondary solid phase formation on the spent nuclear fuel as an important mechanism for strontium retention in a high-level nuclear waste repository (HLNW). Copyright 2010 Elsevier B.V. All rights reserved.

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)

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)

Instant release fraction corrosion studies of commercial UO{sub 2} BWR spent nuclear fuel

Energy Technology Data Exchange (ETDEWEB)

Martínez-Torrents, Albert, E-mail: albert.martinez@ctm.com.es [Fundació CTM Centre Tecnològic, Plaça de la Ciència 2, 08243 Manresa (Spain); Serrano-Purroy, Daniel [European Commission, DG Joint Research Centre - JRC, Directorate G - Nuclear Safety & Security, Department G.III, P.O. Box 2340, D-76125 Karlsruhe (Germany); Sureda, Rosa [Fundació CTM Centre Tecnològic, Plaça de la Ciència 2, 08243 Manresa (Spain); Casas, Ignasi [Department of Chemical Engineering, Universitat Politècnica de Catalunya – Barcelona Tech, Eduard Maristany 14, 08019 Barcelona (Spain); Pablo, Joan de [Fundació CTM Centre Tecnològic, Plaça de la Ciència 2, 08243 Manresa (Spain); Department of Chemical Engineering, Universitat Politècnica de Catalunya – Barcelona Tech, Eduard Maristany 14, 08019 Barcelona (Spain)

2017-05-15

The instant release fraction of a spent nuclear fuel is a matter of concern in the performance assessment of a deep geological repository since it increases the radiological risk. Corrosion studies of two different spent nuclear fuels were performed using bicarbonate water under oxidizing conditions to study their instant release fraction. From each fuel, cladded segments and powder samples obtained at different radial positions were used. The results were normalised using the specific surface area to permit a comparison between fuels and samples. Different radionuclide dissolution patterns were studied in terms of water contact availability and radial distribution in the spent nuclear fuel. The relationship between the results of this work and morphological parameters like the grain size or irradiation parameters such as the burn-up or the linear power density was studied in order to increase the understanding of the instant release fraction formation.

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

The nuclear fuel cycle is complete

International Nuclear Information System (INIS)

Hildenbrand, G.

1984-01-01

The nuclear fuel cycle in the Federal Republic of Germany has a firm base. Its entry stages, natural uranium, conversion, enrichment, and fuel fabrication, have not only been put on solid grounds in terms of supplies, but have also attained a high degree of technical maturity and a high quality level. Further efforts are being devoted to cost reductions. Especially higher burnups and the recycling of plutonium in the form of MOX fuel assemblies in light water reactors must be mentioned under this heading. In the field of back end fuel cycle steps, the important sector of interim storage has now found a practical solution, which is also fully sufficient with respect to capacity. The project of a German reprocessing plant has now entered its decisive stage with the filling of the licensing applications and the awarding of the planning contracts. The study on alternative waste management techniques entitled ''Direct Final Storage'' is about to be concluded, and a work on the exploration and development of a repository proceeds on schedule. (orig.) [de

Anticipating Potential Waste Acceptance Criteria for Defense Spent Nuclear Fuel

International Nuclear Information System (INIS)

Rechard, R.P.; Lord, M.E.; Stockman, C.T.; McCurley, R.D.

1997-01-01

The Office of Environmental Management of the U.S. Department of Energy is responsible for the safe management and disposal of DOE owned defense spent nuclear fuel and high level waste (DSNF/DHLW). A desirable option, direct disposal of the waste in the potential repository at Yucca Mountain, depends on the final waste acceptance criteria, which will be set by DOE's Office of Civilian Radioactive Waste Management (OCRWM). However, evolving regulations make it difficult to determine what the final acceptance criteria will be. A method of anticipating waste acceptance criteria is to gain an understanding of the DOE owned waste types and their behavior in a disposal system through a performance assessment and contrast such behavior with characteristics of commercial spent fuel. Preliminary results from such an analysis indicate that releases of 99Tc and 237Np from commercial spent fuel exceed those of the DSNF/DHLW; thus, if commercial spent fuel can meet the waste acceptance criteria, then DSNF can also meet the criteria. In large part, these results are caused by the small percentage of total activity of the DSNF in the repository (1.5%) and regulatory mass (4%), and also because commercial fuel cladding was assumed to provide no protection

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

Exploratory Design of a Reactor/Fuel Cycle Using Spent Nuclear Fuel Without Conventional Reprocessing - 13579

International Nuclear Information System (INIS)

Bertch, Timothy C.; Schleicher, Robert W.; Rawls, John D.

2013-01-01

General Atomics has started design of a waste to energy nuclear reactor (EM2) that can use light water reactor (LWR) spent nuclear fuel (SNF). This effort addresses two problems: using an advanced small reactor with long core life to reduce nuclear energy overnight cost and providing a disposal path for LWR SNF. LWR SNF is re-fabricated into new EM2 fuel using a dry voloxidation process modeled on AIROX/ OREOX processes which remove some of the fission products but no heavy metals. By not removing all of the fission products the fuel remains self-protecting. By not separating heavy metals, the process remains proliferation resistant. Implementation of Energy Multiplier Module (EM2) fuel cycle will provide low cost nuclear energy while providing a long term LWR SNF disposition path which is important for LWR waste confidence. With LWR waste confidence recent impacts on reactor licensing, an alternate disposition path is highly relevant. Centered on a reactor operating at 250 MWe, the compact electricity generating system design maximizes site flexibility with truck transport of all system components and available dry cooling features that removes the need to be located near a body of water. A high temperature system using helium coolant, electricity is efficiently produced using an asynchronous high-speed gas turbine while the LWR SNF is converted to fission products. Reactor design features such as vented fuel and silicon carbide cladding support reactor operation for decades between refueling, with improved fuel utilization. Beyond the reactor, the fuel cycle is designed so that subsequent generations of EM2 reactor fuel will use the previous EM2 discharge, providing its own waste confidence plus eliminating the need for enrichment after the first generation. Additional LWR SNF is added at each re-fabrication to replace the removed fission products. The fuel cycle uses a dry voloxidation process for both the initial LWR SNF re-fabrication and later for EM2

Exploratory Design of a Reactor/Fuel Cycle Using Spent Nuclear Fuel Without Conventional Reprocessing - 13579

Energy Technology Data Exchange (ETDEWEB)

Bertch, Timothy C.; Schleicher, Robert W.; Rawls, John D. [General Atomics 3550 General Atomics Court San Diego, CA 92130 (United States)

2013-07-01