Proposal for a R&D cooperative program to enhance severe accident management in existing and future NPPs within the OECD/NEA NI2050 initiative

A R&D cooperative program proposal to enhance Severe Accident Management in existing and future NPPs within the OECD/NEA NI2050 initiative D. Jacquemain (IRSN, France) and K. Funaki (OECD/NEA, France) As part of the Nuclear Innovation 2050 (NI2050) initiative conducted under the OECD/NEA auspices, a cooperative research program proposal to enhance severe accident management in existing and future NPPs has been drafted with contribution of regulators, technical support organizations and research expert sas well as industry representatives. The proposed program addresses challenges and opportunities for four selected ^high priority topics: - Topic 1: Consolidation of degraded fuel management strategies (retention and cooling) for existing reactors, in reactor and SFP, and development of innovative ones for future reactors, - Topic 2: Reinforcement of confinement preservation measures, radioactive releases mitigation means and consolidation of Source Term (ST) evaluations for existing and future reactors, - Topic 3: Reinforcement of SA instrumentation including harmonization in qualification, behavior of existing instrumentation and development of innovative instrumentation, - Topic 4: Consolidation of SA knowledge base, methods and tools to better support SA analyses (including PSA), SAMG validation and implementation and decision-making in emergency phases. The proposed program covers selected topics for which (1) it is important to maintain or develop unique competences and infrastructures and to help building resources and funding for the performance of well-targeted large international joint research programs (2) effective results in terms of technological developments supporting SAM strategies and providing significant safety improvements - with potential back-fitting developments in generation II and III plants - can be expected in the next 5 to 10 years (3) results supporting the licensing of new fuel concepts (e.g. accident tolerant fuels (ATF)) and the development of future designs (e.g., generation IV and SMR) can be expected in the next 10 to 20 years (4) innovation can be pushed for future industrial developments to be deployed by the 2040's. In addition, it is also proposed to address a transverse action dealing with SA knowledge collection, review, sustainability, sharing and integration in SA analysis tools and methodologies as they are critical for SAM consolidation for existing designs and for proposing innovative SAM developments for future designs. They are also critical for designing well-targeted research in the field taking advantage of the largest possible existing background and of more harmonized approaches. Near term actions to be conducted internationally have also been identified in each of the above area to further prioritize research actions and define necessary resources and infrastructures to conduct the program. (author)