Abstract: This paper presents MFM builder, a platform based on Multilevel Flow Modeling (MFM), which provides a graphical interface for modeling functions of complex artificial systems such as nuclear power plant with emphasizing the designed purposes of systems. Several algorithms based on MFM have been developed for dynamic system reliability analysis, fault diagnosis and quantitative software reliability analysis. A Reliability Monitoring System (RMS) of PWR nuclear power plant was developed by integrating above algorithms. Experiments by connecting RMS with a full scale PWR simulator showed that it took 16 seconds for RMS calculating the reliability changes over time of safety-related systems according to given system configurations in the 31 days by one computer run. The proposed reliability monitoring system can be used not only offline as a reliability analysis tool to assist the plant maintenance staffs in maintenance plan making, but also online as a operator support system to assist the operators in Main Control Room (MCR) in their various tasks such as configuration management, fault diagnosis and operational decision making.

Keyword: functional modeling; reliability analysis; fault diagnosis; risk monitor