The manipulation of time-varying dynamic variables using the rule modification method and performance-index in NPP accident diagnostic expert systems

When one is developing an expert system for nuclear power plant accident diagnosis, the most difficult problem is the manipulation of the time-varying dynamic variables. To meet this need, a study has been undertaken to modify the rules for accident diagnosis when plant parameters and conditions are varying. In addition to the rule modification method, pattern matching method which is using the performance-index is suggested. This system has also used the results of transient analysis and accident analysis codes as a data base. To simulate the expert system, PROLOG was used to construct the knowledge base. The inherent backtracking inference strategy was used for the inference engine