Human reliability analysis in NPP: A plant-specific sensitivity analysis considering dynamic operator actions versus accident management actions

The human reliability analysis is a method by which, in general terms, the human impact to the safety and risk of a nuclear power plant operation can be modelled, quantified and analyzed. It is an indispensable element of the PSA process within the nuclear industry nowadays. The paper herein presents a sensitivity study of the human reliability analysis performed on a realistic nuclear power plant-specific probabilistic safety assessment model. The analysis is performed on a pre-selected set of post-imitator operator actions. The purpose of the study is to investigate the impact of these operator actions on the plant risk by altering their corresponding human error probabilities in a wide spectrum. The results direct the fact that the future effort should be focused on maintaining the current human reliability level, i.e. not letting it worsen, rather than improving it.