Nuclear Power Plant Operator Performance Analysis Using Training Simulators. Operator Performance under Abnormal Plant Conditions.

Abstract

This paper deals with a research on human factors performed by the Japanese BWR group, focusing mainly on the work done in Phase I (1984–86) of the research project. As a first simulator study of operator performance during accidents in the nuclear field in Japan, it was necessary to develop analysis methods to identify and quantify operator errors. The performance of operators under plant abnormal conditions was analyzed using full-scale BWR plant simulators. By utilizing on-line plant data collection systems and audio/video devices, data were gathered from actual plant operators in the retraining courses on two full-scale simulators at the BWR operator training center in Japan. More than a hundred cases of operator performance data were analyzed to identify human errors and to classify the types of errors. For application to probabilistic safety assessment (PAS), error probabilities were estimated and compared with existing data. Quantification of cognitive errors was also performed based on the Time-Reliability Correlation. An assessment of the effects of human factors in PSA suggested the importance of errors in the operators' cognitive processes, which accounted for the major effects of errors in tasks of high safety significance. The results of the analysis esrve as a basis for building a data bank to be utilized for multiple purposes of PSA, man-machine interface improvement and operator training.