Probability safety assessment support for the maintenance rule at Qinshan NPP1

This paper first briefly describes the US maintenance rules, and the 'Technical Policy for the Improvement of Maintenance Effectiveness of Nuclear Power Plants (Trial)' issued by the National Nuclear Safety Administration (NNSA) in August 2017. The reasons to implement the Maintenance Rules (MR) at Qinshan NPP1 are also introduced. The important role played by PSA during the implementation of the MR project at Qinshan NPP1 was described in detail: 1) Determining the risk-significant SSCs; 2) Establishing SSCs performance criteria for reliability and availability; 3) Risk assessment and management of maintenance activities; 4) Periodically evaluating the impact of MR implementation on CDF. (author)