Processing of Switching Events Sets in reliability and probabilistic safety assessment program RiskA

Fault tree analysis and event tree analysis are the general methods for reliability and probabilistic safety assessment (PSA). In PSA programs, boundary conditions of analysis in fault tree and event tree can make convenience in the modeling and the analysis process. However, handling the logical value conflicts of the same events in different boundary conditions is one of the difficulties in the PSA programs. A new event type named Switching Event and processing method of Switching Events Set is introduced in this paper. The methods implemented in RiskA, which is a reliability and probabilistic safety assessment program developed by FDS Team, and their applications in real power plant model were also proposed and discussed in this paper.