Resilience of nuclear plants in case of hazards

Internal and external hazards analysis methods have been used recently to evaluate operating nuclear power plants (NPP) and to identify the resilience of NPP in case of hazards and potential needs for modification of plant systems and procedures as well as to support design of new plants The external hazards risk contribution has been modeled in many NPP PSA (at least for some external hazards) over the last decade, including events occurring during shutdown and low power operations. Recently, a revision of the German nuclear safety regulations has been successfully completed and these regulations entitled “Safety Requirements for Nuclear Power Plants”, also requiring a detailed investigation of internal and external hazards and combinations of different hazards applying deterministic and probabilistic safety assessment methods.