Uncertainty Assessment in Regulatory Judgement and Decisionmaking

  • B. Faust
Conference paper


The significance of uncertainty assessment of nuclear power plants (NPP) has been widely recognized [1], [2]. Defense-in-depth requires to effectively account for them. Their explicit quantification improves regulatory judgment and helps decisionmakers set priorities in addressing the most important upgrade or repair activities with respect to safety, economics and time [3], [4]. Decisions become more transparent in front of the stakeholders and, a higher power level may be allowed if exaggerated conservatisms are removed. In order to avoid that safety margins are introduced twice, political perceptions have to be clearly separated from consequence analyses. Conservatism and the way how different objectives should be weighted are part of risk management and, not of uncertainty description itself. This paper deals with the explicit formulation and hierarchical structuring of uncertainty in dependence of its safety relevance. Operators and regulatory bodies are provided with ideas useful for including risk-informed aspects to move into integrated decisionmaking.


Nuclear Power Plant Epistemic Uncertainty Probabilistic Seismic Hazard Analysis Uncertainty Assessment Aleatory Uncertainty 


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Copyright information

© Springer-Verlag London 2004

Authors and Affiliations

  • B. Faust
    • 1
  1. 1.Swiss Federal Nuclear Safety Inspectorate (HSK)VilligenSwitzerland

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