Adding a new perspective to the existing results by baseline NPP PSA model: parameters uncertainty implementation

摘要

The paper describes the ongoing project of introducing parameters' uncertainty into the baseline PSA model of Nuclear Power Plant Krsko (NEK). Up to now, the values of parameters in PSA model were expressed as point estimates. As more and more stress has been put to the importance of uncertainty analyses when using PSA in risk-informed applications, the decision was made to incorporate parameter uncertainty analysis into NEK PSA model for internal events. The major categories of parameters that are treated in this paper are probabilities of components' failure per demand, failure rates and unavailability due to test and maintenance (TM). Uncertainty distributions of these types of parameters have been introduced into the model and uncertainty has been propagated to the core damage frequency (CDF) level. The paper presents uncertainty distribution of CDF and provides a discussion on some relevant issues associated with the subject.