Analysis of the impact of external flooding to nuclear installations

The German regulatory body has issued probabilistic safety assessment guidelines, elaborated for a comprehensive integrated safety review of all NPP in operation and containing a newly developed graded approach for the probabilistic assessment of external flooding. Main aspects are explained such as the underlying probabilistic considerations and the mathematical procedures for the calculation of exceedance frequencies. Exemplarily it has been investigated if extreme events such as tsunami waves could be a hazard for NPP at coastal sites in Germany.