Development of an Integrity Evaluation Method for Safety-Critical Components of NPPs Using MFM

The maintenance strategy of NPPs has been changed from time-based maintenance to condition-based maintenance. In this study, the safety-critical components included in safety-critical system can be usually divided into motor-driven valves and pumps. Among the various pumps included in safety-critical component, high pressure safety injection pump was selected and the failure modes of safety-critical components are analyzed to develop the monitoring technology. Also, this study developed the integrity evaluation method using MFM. This is a methodology in means-end and part-whole way, for automatic real time fault diagnosis of power plant process failure. This study shows MFM based fault diagnosis approach for the HPSI pump. Therefore, the possibility of using MFM for the integrity evaluation for HPSI pump in confirmed through this study