Probabilistic safety assessment improves surveillance requirements in technical specifications

Probabilistic Safety Assessment is widely becoming the standard method for assessing, maintaining, assuring and improving the nuclear power plant safety. To achieve one of its many potential benefits, the optimization approach of surveillance requirements in technical specifications was developed. Surveillance requirements in technical specifications define the surveillance test intervals for the equipment to be tested and the testing strategy. This optimization approach based mainly on probabilistic safety assessment results consists of three levels: component level, system level and plant level. The application of this optimization approach on system level has shown that the risk based surveillance requirements differ from existing ones in technical specifications.