Probabilistic safety assessment/probabilistic risk assessment (PSA/PRA) for new and advanced reactors is recognized as an important approach to achieve improved safety for the future nuclear power plants. For the purpose of this work, new reactors are defined as having a stable general design which is typically within five to ten years of commencing power operations. Advanced reactors are reactors which are generally in the earlier conceptual or preliminary design stage.
The ability of current PSA technology to support design decisions for such reactors, and the potential value of advanced methods have not been internationally assessed in recent times. The OECD/NEA Committee for the Safety of Nuclear Installations’ (CSNI) Working Group on Risk Assessment (WGRISK) was thus assigned two co-ordinated tasks: “PSA for Advanced Reactors” and “PSA in the Frame of Design and Commissioning of New NPPs”.
In order to support the objectives of these two tasks, two task-specific questionnaires were developed by the task core groups and answered by the participating countries and organisations (13 responses were received for the advanced reactor questionnaire, and 16 responses were received for the new reactor questionnaire). Additionally, a joint workshop entitled “OECD/NEA Workshop on PSA for New and Advanced Reactors” was held at the OECD Conference Centre in Paris, France on 20-24 June 2011.