ABSTRACT
Passive safety system has been implemented in modern nuclear power plant AP1000 to enhance safety and reliability of the plant. The reliability of the AP1000 passive safety system has been studied by using generic historical failure data of its components. This failure data may have different types of uncertainties. With this possibility, the actual performance of the AP1000 passive safety system cannot be shown. The present study proposes an approach to assess the reliability of the AP1000 passive safety system by utilizing the qualitative data such as expert opinions/judgments. The likelihood occurrence possibilities of basic events are described by experts’ opinions. These qualitative occurrence possibilities of bottom events are then quantified as membership and non-membership functions of triangular intuitionistic fuzzy numbers. The motivation of the study is to present a new approach to studying the reliability of components of the AP1000 passive safety system by utilizing available qualitative data when precise quantitative failure data of its components are currently unavailable or insufficient. The results obtained by the proposed approach are very close to the results obtained in previous studies and confirm that the proposed approach offers a more realistic way to study the reliability of the AP1000 passive safety system under intuitionistic fuzzy environment.
