Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel FIRST-Nuclides

Transcription

1 PROJECT PRESENTATION (PP) Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel FIRST-Nuclides Contract (grant agreement) number: Author(s): AMPHOS 21, KIT-INE Date of issue of this report: 01/12/2011

2 Introduction The Collaborative Project Fast / Instant Release of Safety Relevant Radionuclides from Spent Nuclear Fuel (CP FIRST-Nuclides) is established with the overall objective to provide for improved understanding of the fast / instantly released radionuclides from disposed high burn-up UO 2 spent nuclear fuel. 1. Nature and scope of the project The present project deals with understanding the behaviour of high burn-up spent uranium oxide (UO 2 ) fuels in geological repositories. This waste type represents the source for a significant release of radionuclides after loss of the canister integrity. For safety analysis, the time-dependent release of radionuclides is required. The project is implemented by 6 experimental facilities having specialized installations and equipment for work with highly radioactive materials and 4 organizations having specific knowledge in conceptualization of processes, and their formulation in models. National Waste Management Organizations contribute to the project by co-funding to beneficiaries and providing for knowledge and information. The project beneficiaries provide experimental facilities having specialized equipment for working with highly radioactive spent nuclear fuel in combination with advanced experimental techniques and analytical methods and experience. 2. Activities The added value of the project initiation consists in a direct answer to the inadequately supported knowledge on fast/instant radionuclide release for license applications related to disposal of high burn-up fuel. The knowledge and data obtained will reduce the uncertainties and will provide for realistic data on the relevant radionuclide release for the Safety Case leading to an increased confidence in capability of predictions. In particular, it is expected that the scientific basis will be strengthened with respect to decrease the calculated peak-doses to individuals. The project contributes to the Safety Case of all European disposal concepts for spent nuclear fuel. The results generated are communicated within the project but also to a broader interested community. For this purpose, a large number of activities are included to help knowledge management dissemination and communication, such as the WEB portal of the project, organizing project workshops, communicating the outcome of the project by participating at international conferences, workshops and other types of events where presentation of the project and its results will be exposed. Training activities will include the invitation of experts to the annual workshops and training on the job through mobility measures. Finally, a plan for training course on physics and chemistry of spent nuclear fuel and on related modeling will be discussed 3. Expected results The project will start on 1 st January 2012 and will last 3 years ( ). With respect to the determination and quantification of the fast/instant release fraction of radionuclides from high burn-up spent nuclear fuel and the application of this information to the Safety Assessment and Safety Case for geological disposal, the work plan includes a detailed experimental programme combined with modelling studies. Specifically, the project includes the following elements and aims: (i) selection, characterization and preparation of materials and set-up of tools for handling and transportation of the highly radioactive material, (ii) experimental de- 2

3 termination of fission gas release, (iii) experimental investigation of rim and grain boundary diffusion, (iv) dissolution based radionuclide release and (to the extent possible) the chemical speciation of the relevant isotopes, (v) modelling of migration/retention processes and of chemical speciation of fission products in the spent fuel structure, the grain boundaries, and in the pellet interfaces, (vi) assessing and discussing the potential impact on the Safety Case, (vii) documentation of the State-of-the-Art with regular up-dating, stepwise build-up of scientific-technical reporting, its dissemination and communication, as well as training, and finally (viii) the project coordination and management. Available analytical techniques and infrastructures of the project KIT-INE 4. Societal impact The main expected impact of the project is to obtain improved data for the rapid release fraction for spent uranium oxide fuel and improved understanding of its dissolution behaviour - in relation to licensing repositories for operation by Over the next 5-10 years the average fuel burn-up will increase for many reactors. For this reason, the key objectives of the project consider the high burn-up UO2 fuel and requirements for the Disposal Safety Case independent on the host rock under consideration with respect to: experimental determination of fission gas distribution in fuel pellets, the gas release after puncturing of high burn-up spent fuel rods or segments and determination of fission gas release from spent fuel in the case of contact with an aquatic phase. The expected outcome is an experimentally based database and numerical tools for the prediction of the fast/instant release of fission and activation products for the whole range of UO2 fuel elements to be disposed of in Europe. These include Pressurized water reactor (PWR) and boiling water reactors (BWR) fuels of different initial enrichments, fuel element configurations, burn-up and burn-up history as well as linear power and fuel temperatures. Another outcome from implementing the work program is that the Consortium members become aware of the respective complementary competencies and thus can jointly tackle follow-up problems in the future. 5. Information about important public events One kick-off meeting and three Project Workshops are key elements in the implementation of the project. The Project Workshops contribute to integration within the project and communication with a broader interested community. The Kick-Off meeting will be held in Barcelona, Spain on 9th-10th February

4 On the other hand, the experimental and modelling plans of the project will be presented on the forthcoming Spent Fuel Workshop in Avignon (April 2012) and the Annual Meeting on Nuclear Technology in Stuttgart (May 2012). 4

5 Project information Website address: Project type: Collaborative Project (Small/medium scale focused) Project start date: 01/01/2012 Duration: 36 months Total budget: EUR 4,741,261 EC contribution: EUR 2,494,513 EC project officer: Christophe Davies European Commission Directorate-General for Research Directorate Energy (Euratom) Unit J.2 Fission CDMA 1/61, B-1049 Brussels, Belgium. Coordinator: Bernhard Kienzler Karlsruher Institut für Technologie, Institut für Nukleare Entsorgung, KIT-INE Hermann-von-Helmholtz-Platz1, Eggenstein-Leopoldshafen, Germany. Telephone: Fax: Partners: Partner number Partner full name Short name Country code (2-letter ISO code*) 1 KARLSRUHER INSTITUT FUER TECHNOLOGIE KIT DE 2 AMPHOS 21 CONSULTING S.L. AMPHOS21 ES JOINT RESEARCH CENTRE INSTITUTE FOR JRC-ITU EC 3 TRANSURANIUM ELEMENTS 4 FORSCHUNGSZENTRUM JUELICH GMBH JÜLICH DE 5 PAUL SCHERRER INSTITUT PSI CH 6 STUDIECENTRUM VOOR KERNENERGIE SCK CEN BE 7 CENTRE NATIONAL DE LA RECHERCHE CNRS FR SCIENTIFIQUE 5

6 8 FUNDACIO CTM CENTRE TECNOLOGIC CTM ES MAGYAR TUDOMANYOS AKADEMIA KFKI AEKI HU 9 ATOMENERGIA KUTATOINTEZET 10 STUDSVIK NUCLEAR AB STUDSVIK SE * List of country codes: 6