Functional Failure Analysis for Passive Containment Cooling System in AP1000

摘要

More and more attention is paid to probability safety assessment (PSA) especially after several severe accidents in nuclear power development and PSA has been widely used now for nuclear power plant safety evaluation, design update and so on, system reliability analysis is one of the important aspects in PSA. In order to improve the safety of new generation nuclear power plant, passive containment cooling system is innovatively used in AP1000 reactor design (Ref.1), which is an important safety-related system. By this system heat produced in the reactor can be transferred to the heat sink - atmosphere depending on natural circulation, but not on the human behaviors or the operation of other equipments (Ref. 2,3).