Fuzzy FMEA applied to PWR chemical and Volume Control System

In this paper, a fuzzy inference system (FIS) modeling technique is introduced to treat a nuclear reliability engineering problem. This method uses the concept of a pure fuzzy logic system where the fuzzy rule base consists of a collection of fuzzy IF-THEN rules. The fuzzy inference engine uses these fuzzy IF-THEN rules to determine a mapping of the input universe of discourse over the output universe of discourse based on fuzzy logic principles. The risk priority number (RPN) (typical of a traditional Failure Mode & Effects Analysis - FMEA) is calculated and compared to fuzzy risk priority number (FRPN), obtained by the use of the scores from expert opinion. These scores are opinions about probabilities of Occurrence, Severity and not Detection of a failure of the studied system. The Chemical and Volume Control System was adopt as practical example in the study of case. The results demonstrated the potential of the inference system to this problem class. (C) 2004 Elsevier Ltd. All rights reserved.