ASME ANS/ASME RA-S-1.1-2024

This nuclear standard states requirements for a Level 1 Probabilistic Risk Assessment (PRA) of internal and external hazards while at-power for the evaluation of core damage frequency (CDF). In addition, this standard states requirements for a limited Level 2 PRA sufficient to evaluate large early release frequency (LERF). The only hazards explicitly excluded from the scope are accidents resulting from purposeful human-induced security threats (e.g., sabotage, terrorism). These requirements are written for operating light water reactor (LWR) nuclear power plants. This standard may be used for LWR plants under design or construction or for advanced LWRs, such as small modular reactors (SMR), but revised or additional requirements may be needed.