Risk analysis of external hydrological hazards with flooding potential for a German nuclear reference site

Probabilistic Safety Analyses (PSA) are a supplementary analytical tool used worldwide more and more in order to quantitatively assess the effect of hazards on the overall result regarding the safety of industrial installations, in particular nuclear power plants. In that way PSA provides a reliable basis for decisions on the necessity and the benefits of safety improvements. In the recent past, the existing methods and tools with respect to determining the site-specific risk of nuclear power plants have been comprehensively extended and further enhanced. The focus of extending the existing PSA methods was on external hydrological hazards with flooding potential. For systematically considering hydrological hazards within PSA a systematic approach has been developed. The paper demonstrates the extended approach in the example of a nuclear power plant site with different flooding risks.