An analysis of operator performance in plant abnormal conditions

A study on operator performance was conducted based on full-scope simulator data taken from a retraining course of BWR (boiling water reactor) plant operators. Emphasis was placed on analyzing operators´ behaviour in abnormal plant conditions. Analyses were made to identify and classify errors and to examine the causes and contributing factors of the observed errors. Error rates were estimated and compared with existing data. Quantification of cognitive errors was also performed based on operators´ response times. It is concluded that the results can serve as a basis for building a database to be utilized for multiple purposes of probabilistic safety assessment, man-machine interface improvement, and operator training.<>