Research on evaluation method of NPPs operator’s response plan reliability based on Bayesian network

Abstract An operator’s response plan is a critical individual factor influencing human reliability in Nuclear Power Plants (NPPs), yet it is often under-represented in traditional Human Reliability Analysis (HRA). This paper proposed a method to evaluate the reliability of an operator’s response plan to reduce human errors. Firstly, this study identified key influencing factors in the digital main control room (DMCR) context and constructed a causal model. Secondly, a Bayesian network was developed to quantify response plan reliability, using IF-THEN rules to define conditional probabilities derived from expert judgment. Finally, a case study was conducted, the calculation result of response plan reliability was 0.936. This result was validated against SPAR-H calculation, showing a deviation of only 0.042 and demonstrating the method’s effectiveness. This approach provides a valuable tool for analyzing response plan reliability and offers a quantitative reference for comprehensive HRA in NPPs.