SR 97: Post-Closure Safety for a KBS 3 Deep Repository for Spent Nuclear Fuel - Overview -

2000 ◽  
Vol 663 ◽  
Author(s):  
Allan Hedin ◽  
Ulrik Kautsky ◽  
Lena Morén ◽  
Jan-Olof Selroos ◽  
Patrik Sellin ◽  
...  
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Bentonite Clay ◽  
High Strength ◽  
Functional Requirements ◽  
Future Evolution ◽  
Site Investigations ◽  
Base Scenario ◽  
Shed Light

ABSTRACTIn preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Company, SKB has carried out the long- term safety assessment SR 97, requested by the Swedish Government. The repository is of the KBS-3 type, where the fuel is placed in isolating copper canisters with a high-strength cast iron insert. The canisters are surrounded by bentonite clay in individual deposition holes at a depth of 500 m in granitic bedrock. 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, including climate, persist. The four other scenarios show the evolution if the repository contains a few initially defective canisters, in the event of climate change, in the event of earthquakes, and in the event of future inadvertent human intrusion.The principal conclusion of the assessment is that the prospects of building a safe deep repository for spent nuclear fuel in Swedish granitic bedrock are very good. The results of the assessment also serve as a basis for formulating requirements and preferences regarding the bedrock in site investigations, for designing a program for site investigations, for formulating functional requirements on the repository's barriers, and for prioritization of research.

The SR 97 Safety Assessment of a KBS 3 Repository for Spent Nuclear Fuel – Overview, Review Comments and New Developments

2002 ◽  
Vol 713 ◽  
Author(s):  
Allan Hedin ◽  
Ulrik Kautsky ◽  
Lena Morén ◽  
Patrik Sellin ◽  
Jan-Olof Selroos
Keyword(s):  
Nuclear Fuel ◽  
Safety Assessment ◽  
Spent Nuclear Fuel ◽  
Bentonite Clay ◽  
Research Programme ◽  
High Strength ◽  
Functional Requirements ◽  
Future Evolution ◽  
Site Investigations ◽  
Potential Safety

ABSTRACTIn preparation for coming site investigations for siting of a deep repository for spent nuclear fuel, the Swedish Nuclear Fuel and Waste Management Company, SKB has carried out the longterm safety assessment SR 97, requested by the Swedish Government. The repository is of the KBS-3 type, where the fuel is placed in isolating copper canisters with a high-strength cast iron insert. The canisters are surrounded by bentonite clay in individual deposition holes at a depth of 500 m in granitic bedrock. 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 analysed in the form of five scenarios. The first is a base scenario where the repository is postulated to be built entirely according to specifications and where present-day conditions in the surroundings, including climate, persist. The four other scenarios show the evolution if the repository contains a few initially defective canisters, in the event of climate change, in the event of earthquakes, and in the event of future inadvertent human intrusion.The principal conclusion of the assessment is that the prospects of building a safe deep repository for spent nuclear fuel in Swedish granitic bedrock are very good. The results of the assessment also serve as a basis for formulating requirements and preferences regarding the bedrock in site investigations, for designing a programme for site investigations, for formulating functional requirements on the repository's barriers, and for prioritisation of research.SR 97 has been reviewed both by an international group of OECD/NEA experts and by Swedish authorities. The NEA reviewers concluded that “SR 97 provides a sensible illustration of the potential safety of the KBS-3 concept”, and no issues were identified that need to be resolved prior to proceeding to the investigation of potential sites. The authorities' conclusions were in principal consistent with those of the NEA.Uncertainties and lack of knowledge in different areas identified in SR 97 have strongly influenced the contents and structure of SKBs most recent research programme, RD&DProgramme 2001.Since SR 97, the methodology for probabilistic consequence analyses have been further developed. Analytic approximations to the numerical transport models used in SR 97 have been developed. The new models have been used to extend the probabilistic calculations in SR 97.

Landscape Modeling for Dose Calculations in the Safety Assessment of a Repository for Spent Nuclear Fuel

2007 ◽  
Author(s):  
Tobias Lindborg ◽  
Ulrik Kautsky ◽  
Lars Brydsten
Keyword(s):  
Nuclear Fuel ◽  
Safety Assessment ◽  
Spent Nuclear Fuel ◽  
Landscape Model ◽  
Landscape Development ◽  
Surface Hydrology ◽  
Site Investigations ◽  
Time Period ◽  
The Individual

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 (figure 1). 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 modeled time period, from sea to lake, and from lake to mire and finally, some objects are transformed into agricultural area due to favorable farming characteristics.

scholarly journals Decay heat power of spent nuclear fuel of power reactors with high burnup at long-term storage

2017 ◽  
Vol 153 ◽  
pp. 07035 ◽  
Author(s):  
Mikhail Ternovykh ◽  
Georgy Tikhomirov ◽  
Ivan Saldikov ◽  
Alexander Gerasimov
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Heat Power ◽  
Decay Heat ◽  
Long Term Storage ◽  
High Burnup ◽  
Term Storage

Dissolution of spent nuclear fuel fragments at high alkaline conditions under H2 overpressure

MRS Advances ◽  
2016 ◽  
Vol 1 (62) ◽  
pp. 4163-4168
Author(s):  
E. González-Robles ◽  
M. Herm ◽  
V. Montoya ◽  
N. Müller ◽  
B. Kienzler ◽  
...  
Keyword(s):  
Aqueous Solution ◽  
Partial Pressure ◽  
Nuclear Fuel ◽  
Alkaline Solution ◽  
Spent Nuclear Fuel ◽  
Dissolution Tests ◽  
The Matrix ◽  
Alkaline Conditions ◽  
Long Term Behavior

ABSTRACTThe long-term behavior of the UO2 fuel matrix under conditions of the Belgian “Supercontainer design” was investigated by dissolution tests of high burn-up spent nuclear fuel (SNF) in high alkaline solution under 40 bar of (Ar + 8%H2) atmosphere. Four fragments of SNF, obtained from a pellet previously leached during two years, were exposed to young cement water with Ca (YCWCa) under 3.2 bar H2 partial pressure in four single/independent autoclave experiments for a period of 59, 182, 252 and 341 days, respectively. After a decrease of the concentration of dissolved 238U, which is associated with a reduction of U(VI) to U(IV), the concentration of 238U in solution is constant in the experiments running for 252 and 341 days. These observations indicate an inhibition of the matrix dissolution due to the presence of H2. A slight increase in the concentration of 90Sr and 137Cs in the aqueous solution indicates that there is still dissolution of the grain boundaries. These findings are similar to those reported for spent nuclear fuel corrosion in synthetic near neutral pH solutions.

scholarly journals Modeling of decay heat removal from CONSTOR RBMK-1500 casks during long-term storage of spent nuclear fuel

Energy ◽  
2019 ◽  
Vol 170 ◽  
pp. 978-985 ◽  
Author(s):  
R. Poškas ◽  
V. Šimonis ◽  
H. Jouhara ◽  
P. Poškas
Keyword(s):  
Nuclear Fuel ◽  
Spent Nuclear Fuel ◽  
Heat Removal ◽  
Decay Heat ◽  
Long Term Storage ◽  
Term Storage

Site Investigations of Potential Repository Sites in Sweden

2003 ◽  
Vol 807 ◽  
Author(s):  
Peter Wikberg ◽  
Kaj Ahlbom ◽  
Olle Olsson
Keyword(s):  
Waste Management ◽  
Nuclear Fuel ◽  
Nuclear Waste ◽  
Spent Nuclear Fuel ◽  
Site Investigation ◽  
Management Programme ◽  
Nuclear Waste Management ◽  
Geologic Repository ◽  
The Public ◽  
Site Investigations

ABSTRACTThe Swedish nuclear waste management programme has entered the site investigation phase. Early 2002 SKB received permission from the municipalities of Östhammar and Oskarshamn to perform site investigations for a potential deep geologic repository for spent nuclear fuel. The goal of the site investigation phase is to obtain a permit to build the deep repository for spent nuclear fuel. In parallel with the investigations, consultations will be held with county administrative boards, regulatory authorities and municipalities, as well as with members of the public.

Scenario Development for Safety Assessment of Waste Repository for Feasibility Study on Transmutation of Spent Nuclear Fuel Into LILW Using PEACER

2010 ◽  
Author(s):  
Sung-yeop Kim ◽  
Kun Jai Lee
Keyword(s):  
Liquid Metal ◽  
Nuclear Fuel ◽  
Feasibility Study ◽  
Safety Assessment ◽  
Spent Nuclear Fuel ◽  
Scenario Development ◽  
Development Methodology ◽  
Environmental Friendly ◽  
Base Scenario ◽  
Waste Repository

PEACER (Proliferation-resistant, Environmental-friendly, Accident-tolerant, Continuable-energy and Economical Reactor) is a conceptual liquid metal fast reactor using Pb-Bi as a coolant and feasibility study on transmutation of spent nuclear fuel into LILW (Low and Intermediate Level Waste) using PEACER is in progress. Safety assessment of repository is essential for this feasibility study with assumption that we dispose the wastes from PWRs and PEACERs with established decontamination factors. Scenario development is one of important step for carrying out reliable and comprehensive safety assessment. This study adopted scenario development methodology from H12 report (JNC, 2000) and classified assessment scenarios into base scenario, perturbation scenarios and isolation failure scenarios. Scenarios are established by classifying, screening out and selecting FEPs with concepts and conditions of disposal for feasibility study.

Development and Investigation of High-Strength Neutron-Absorbing Composite Coatings Based on Borides of Metals

2019 ◽  
Vol 945 ◽  
pp. 660-664 ◽  
Author(s):  
A.S. Larionov ◽  
L.V. Chekushina ◽  
E.E. Suslov
Keyword(s):  
Boron Concentration ◽  
Spent Nuclear Fuel ◽  
Composite Coatings ◽  
High Strength ◽  
Nuclear Materials ◽  
Main Role ◽  
Fission Reaction ◽  
Model Calculations ◽  
Program Show

At present, structural materials capable of absorbing thermal neutrons are used for long-term, compacted storage of spent nuclear fuel. This is necessary to prevent the occurrence of a fission reaction in clusters of nuclear materials. A promising direction in this area is the use of neutron-absorbing coatings. In this paper, it is proposed to use coatings of the B-Ti system for this purpose. The model calculations carried out using the MCU-REA program show the sufficient effectiveness of such coatings. The average path length of the neutron in the coating is ~ 90 μm. The dependence of the degree of attenuation of the neutron flux on the thickness of the coating is shown. Calculations show that the main role is played not by the thickness of the coating, but by the boron concentration in the material. For the synthesis of coatings, the method of magnetron sputtering is considered. Аn experimental magnetron boron-containing target for a four-channel magnetron installation VUP-5M was fabricated.

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