Research on Optimization of PAA Method Based on Fault- Tree Analysis

Abstract

Abstract The third generation of nuclear power units with million kilowatt capacities which are highly developed now are required to reach the advanced technical level of the third generation of nuclear power on the basis of meeting relevant reliability requirements of URD (Utility Requirement Document) and EUR (European Utility Requirement). Forced unavailability not only influences economic indicators of nuclear power units like availability, but also seriously threatens safe operation of units. However, at present, it does not take into account the requirements of unavailability in China. In this paper, based on Probabilistic Availability Assessment (PAA) method, an improved method based on Fault-Tree Analysis is proposed to solve the problem that the unit shut down due to the dual or multiple failure of the equipment. And the Chemical and volume control systems RCV is taken as an example to show that the results of the fault tree method are more accurate and reliable, and the Probabilistic Availability Assessment method is optimized. It has a good reference for the design and development of new nuclear power units, system configuration, equipment selection and so on, and also provides the reference for the readers.