PSA based vulnerability and protectability analysis for NPPs

Highlights: ► The paper describes the generation of location sets and protection sets. ► Vulnerability and protectability used to rank location sets and protection sets. ► Ranking helps in adequacy of protection measures employed in various locations. ► The procedure for PSA based vital area identification is demonstrated. ► This method has found practical applicability for Indian NPP. -- Abstract: Identification of vital areas in a facility involves assessing the facility and the locations, whose sabotage can result in undesirable (radiological) consequences. Probabilistic Safety Assessment (PSA) technique can find the component failures leading to core damage (a surrogate for radiological consequence) in a systematic manner, which can be extended to identification of vital areas. This paper describes the procedure for the generation of location sets (set of locations whose sabotage can lead to possible core damage) and protection sets (set of locations that must be protected to prevent possible core damage). In addition, measures such as vulnerability and protectability have been introduced, which can be used to rank location sets and protection sets.