The overall objective of the OECD Nuclear Energy Agency (NEA) Committee on the Safety of Nuclear Installations (CSNI) Working Group on Risk Assessment (WGRISK) is to permanently enhance the understanding of probabil-istic safety assessment (PSAa) and facilitate the use and application of probabilistic approaches as an important tool for nuclear safety assessment. WGRISK therefore carries out various activities for risk related information exchange between PSA experts in member countries and advancing the use of this tool for improving safety.
WGRISK has recently completed four tasks, the regular report on the use and development of Probabilistic Safety Assessment, two Technical Opinion Papers (TOPs) on Fire PSA and Seismic PSA and a task report on the “Status of Site-Level PSA (Including Multi-Unit PSA) Developments” exchanging information on addressing mul-tiple reactor and radioactive source issues in PSA and the corresponding challenges.
Currently, three WGRISK activities are ongoing and close to completion:
- Human Reliability Analysis in External Events PSA – Survey of Methods and Practice;
- Use of OECD/NEA Database Project Operating Experience Data for Probabilistic Safety Assessment;
- Comparative Application of DIGital I&C Modelling Approaches for PSA (DIGMAP).
Two activities have recently been started:
- Dynamic PSA Methodologies – Preparing for the Future;
- Combinations of External Hazards – Hazard and Impact Assessment and Probabilistic Safety Analysis (PSA) for Nuclear Installations.
Moreover, WGRISK is planning further tasks on “PSA for Unique Reactors (e.g. first-of-a-kind, demonstration, and research reactors)” and a “Level 3 PSA Codes Benchmark Exercise”.
Additional ideas for future activities include information exchange, e.g. on PSA applications in support of risk-informed decision making (RIDM) and safety management and on the modelling of the use of portable (“FLEX”) equipment within PSA in the near future.