Application of the CTN-UPM expert judgement methodology to an hydrogen DDT issue in a generic evolutionary PWR: Phase 2 of the benchmark exercise on expert judgement techniques in PSA level 2

摘要

This work shows the results of an expert judgment application performed at the Polytechnic University of Madrid to evaluate an hydrogen combustion issue in a generic evolutionary PWR. A new expert judgment methodology has been developed and applied. Two in-house experts provided their expertise and judgments. Accident progress event trees were used to analyse the problem and the experts provided probabilities and distributions of probability for the branches of their event trees. The requested distributions of probability were obtaiend via Monte-Carlo simulation. A bayesian method was applied to combine the expert opinions, except when the experts clearly disagreed. In this case opinions were not combined.