Risk Comparison of Methods for Dependency Determination withinHuman Reliability Analysis

摘要

Dependency between human failure events is an issue, which include subjectivity in thernmodels and consequently in the results of human reliability analysis and thus in probabilistic safetyrnassessment. Many methods connected with human reliability analysis were developed in the lastrndecades, which mostly include determination of dependency between human failure events: e.g.rnStandardized Plant Analysis Risk HRA - SPAR-H and Institute Jo?ef Stefan - Human ReliabilityrnAnalysis - IJS-HRA. A comparison of dependency as it is applied within the selected methods isrnperformed on an example probabilistic safety assessment model of a selected nuclear power plant. Pre-initiatorsrnand post-initiators are considered. It is investigated how the contribution of consideration ofrndependency of pre-initiators and dependency of post-initiators and dependency of both impacts thernhuman error probabilities, which are then used within probabilistic safety assessment. The results ofrncomparison show that selection of the method for determining dependency between human failurernevents may largely impact the results of human reliability analysis and consequently the probabilisticrnsafety assessment. The subjectivity can be reduced by development of more detailed guidelines forrnhuman reliability analysis with many detailed practical examples for all steps of the process ofrnevaluation of human performance.