DEVELOPMENT OF WATER CHEMISTRY DIAGNOSTIC SYSTEM FOR BWRS USING FUZZY-REASONING

A diagnostic system for BWR water chemistry has been developed incorpo rating high-speed fuzzy reasoning, holding in view preventive maintena nce as principal objective. The system combines two expert systems-one for detecting an anomaly in the plant operating condition and quickly inferring its cause in a preliminary analysis, and the other performi ng a detailed diagnosis of the detected anomaly. The system for anomal y detection and quick preliminary diagnosis infers the occurrence of v arious anomalies and their causes from the fuzzy relation existing bet ween the fuzzy causes and symptoms, applying a high-speed method for s olving the inverse problem of fuzzy correspondence. The system can be run on a small size computer, and is thus conveniently adapted to prac tical application at machine side. The system for detailed diagnosis i ncorporates the expertise of water chemistry engineers, and outputs pe rtinent information and data to guide operators. Trial application of the system using data from actual plant operation conclusively demonst rated its effectiveness as a practical preventive maintenance system f or actual plants.