The role of PSA in the design improvement program of the Korean Standard Nuclear Power Plant

The purpose for performing the Probabilistic Safety Assessment (PSA) for Improved Korean Standard Nuclear Power Plant (KSNP+) is to assure that the plant safety of KSNP+ is maintained or improved in comparison with Korean Standard Nuclear Power Plant (KSNP+). The PSA generally provides quantitative values such as system unavailability, core damage frequency, etc. to assess the plant safety without affecting the plant design. However, in the conceptual design stage of KSNP+, all of the design improvement items related to plant safety were evaluated by the PSA team. In order to meet the KSNP+ safety goal, safety improvement items based on PSA results were recommended. All of the design recommendations including design vulnerabilities which were identified in the PSA study were reviewed by the design team and some of those items were applied to the design when they were appropriate. As a result, the plant safety of KSNP+ has been enhanced due to incorporation of the safety improvement items.