TY - RPRT TI - Interim summary report of the safety case 2009 AB - Following the guidelines set forth by the Ministry of Trade and Industry (now Ministry of Employment and Economy), Posiva is preparing to submit a construction license application for the final disposal spent nuclear fuel at the Olkiluoto site, Finland, by the end of the year 2012. Disposal will take place in a geological repository implemented according to the KBS-3 method. The long-term safety section supporting the license application will be based on a safety case that, according to the internationally adopted definition, will be a compilation of the evidence, analyses and arguments that quantify and substantiate the safety and the level of expert confidence in the safety of the planned repository. The present Interim Summary Report represents a major contribution to the development of this safety case. The report has been compiled in accordance with Posiva's current plan for preparing this safety case. A full safety case for the KBS-3V variant will be developed to support the Preliminary Safety Assessment Report (PSAR) in 2012. The report outlines the current design and safety concept for the planned repository. It summarises the approach used to formulate scenarios for the evolution of the disposal system over time, describes these scenarios and presents the main models and computer codes used to analyse them. It also discusses compliance with Finnish regulatory requirements for long-term safety of a geological repository and gives the main evidence, arguments and analyses that lead to confidence, on the part of Posiva, in the long-term safety of the planned repository. Current understanding of the evolution of the disposal system indicates that, except a few unlikely circumstances affecting a small number of canisters, spent fuel will remain isolated, and the radionuclides contained within the canisters, for hundreds of thousands of years or more, in accordance with the base scenario. Confidence in this base scenario derives, in the first place, from the intrinsic properties of the main components of the repository and from the understanding of their evolution gained from extensive site- and concept-specific field, laboratory and modelling studies and from studies of natural and anthropogenic analogues. For any canisters that fail over this time window, the low radionuclide calculated release rates to the biosphere and resultant annual effective doses to humans and absorbed dose rates to other species of flora and fauna imply that any radiological consequences of these releases will be negligible. Furthermore, the calculation results indicate that, in general, differences in the geometry and transport paths considered in the analyses of the KBS-3V and KBS-3H design variants have only a minor impact on calculated releases and doses. Work carried out to date indicates that a geological repository for the final disposal of spent fuel, implemented as planned at the Olkiluoto site, will conform to Finnish regulatory requirements and provide an adequate level of longterm safety. This conclusion is based on the findings of safety assessments, the systematic treatment of uncertainty in these assessments and the quality measures that have been applied in the development and application of models, data and computer codes. Plans are in place to manage remaining safety-related issues and uncertainties, as given in the report TKS-2009. In implementing TKS-2009, quality assurance measures will be applied in the various production steps of the safety case, including and tests and experiments to demonstrate the feasibility and quality of technical solutions. In this way, a comprehensive safety case will be developed to support the licensing process. (orig.) AU - "Not Available" KW - "12 MANAGEMENT OF RADIOACTIVE WASTES, AND NON-RADIOACTIVE WASTES FROM NUCLEAR FACILITIES" KW - "FINLAND" KW - "RADIOACTIVE WASTE DISPOSAL" KW - "UNDERGROUND DISPOSAL" KW - "SAFETY ANALYSIS" KW - "RISK ASSESSMENT" KW - "PLANNING" KW - "SPENT FUELS" DO - https://doi.org/ UR - PB - CY - Finland PY - 2010 DA - 2010-03-15 LA - English J2 - [] VL - C1 - Posiva Oy, Helsinki (Finland) C2 - C3 - POSIVA-10-02 C4 - C5 - Available in fulltext at http://www.posiva.fi/files/1226/POSIVA_2010-02web.pdf or as a soft back edition from Posiva Oy, Olkiluoto, 27160 Eurajoki, Finland, tel. +358-2-837231 L3 - Other Information: 137 refs. ER -