Dynamic reliability analysis of AP1000 equipment cooling water system based on BDMP

CCS is a kind of repairable systems with double redundancy. The factors such as the alternate operation of redundant equipment and the repair of faulty equipment have a great influence on the reliability analysis results. Due to the lack of the description of time factors in traditional fault tree analysis, the analysis assumption is too conservative for such dynamic time series problems. In view of the above limitations of fault tree analysis, the dynamic reliability analysis of the AP1000 CCS is carried out by using the BDMP method driven by Boolean logic. Then, based on BDMP model, the simplest fault combination is derived, the system failure probability is calculated, and the main contribution factors of system failure are analyzed. The results show that the failure probability of CCS is sensitive to the CCF of the cooling water pump. Reducing the CCF of the pump can improve the reliability of CCS. (authors)