A Measure for Estimating the Effect of the Input Uncertainty on the Mean Value of the Model Output

AbstractIn Probabilistic Safety Assessment (PSA) of commercial nuclear power plants(Npps), there are uncertainties in the PSA results due to the propagation of the uncertainties in the model inputs through the model. Despite the existence of the output uncertainty, the regulatory body generally adopts the mean value of a PSA results as the policy goal. In this work, we propose an importance measure for evaluating the effect of the input uncertainties on the mean value of the model output. The combination of this proposed measure with the existed uncertainty importance measures is suggested for identifying key inputs of PSA models for effective risk-informed decisionmaking