Advanced human reliability analysis methodology and applications

The human reliability analysis is an integral part of the probabilistic safety assessment for Loviisa 1 NPS. Up to date techniques are used for the three main categories of human failures: pre-accident, post-accident and transient initiating errors. Advancements and plant specific modifications have been made to some state of the art techniques applied in previous PSA studies. The basic error probability of pre-accident errors is modified by error dependency and recovery factors. The probability of diagnosis error is evaluated using an asymmetric confusion matrix and plant specific time-reliability curves. Plant specific human reliability data have been collected and utilized in human error identification and quantification. (orig.)