An improved probabilistic method for screening safety-related human actions in nuclear power plants

For the reliability and safety of nuclear power plants (NPPs), their design and operation must follow the relevant principles of human factors engineering (HFE). As various human actions are involved in the operation of NPPs, there is a need to screen human actions first and, then, focus the analysis on the critical ones. In the past, different NPPs have adopted different standards in screening human actions and many of these standards lack theoretical support. In this study, the concept of human action risk achievement worth (HRAW) is introduced to support probabilistic screening. A new probabilistic method for screening safety-related human actions in NPPs is proposed. The results of a case study indicate that the proposed method performs well and better than the previous probabilistic screening method typically used, it also implies that this method can provides methodological support to the probabilistic screening method of human actions. On the one hand, utilizing this method to screen human actions can help identifying those actions that are critical for the safety of NPPs. On the other hand, it can reduce the workload and improve work efficiency. The method is traceable and easy to use. It not only can be used in the design of NPPs, but also can provide guidelines for reviewers to evaluate the NPPs safety.