Risk considerations in the IAEA's safety standards and PSA-related developments

Probabilistic safety assessment (PSA) of a nuclear power plant (NPP) that is complementing the traditional deterministic analysis is widely recognized as a comprehensive, structured approach to identifying accident scenarios and deriving numerical estimates of risks dealing with NPP operation and associated plant vulnerabilities. Increasingly, during the last years, PSA has been broadly applied to support numerous applications and risk-informed decisions on various operational and regulatory matters. The expanded use of PSA in the risk-informed decision-making process requires that PSA possess certain features to ensure its technical consistency and quality. The issue of PSA quality is in the focus of current activities of the International Atomic Energy Agency (IAEA). The paper draws on risk considerations in the IAEA Safety Standards and the IAEA' s work in the area of PSA quality and highlights the achievements to date and plans for the future. (author)