ASME ANS RA-S-1.1-2022

This Standard states requirements for a Level 1 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 LWR power plants (i.e., plants with designs and features similar to the plants operating when this Standard was published). They may be used for LWR plants under design or construction or for advanced LWRs, but revised or additional requirements may be needed.