DEPENDENCY ANALYSIS OF CRITICAL PARAMETERS INFLUENCING THE RELIABILITY OF THERMAL-HYDRAULIC NUCLEAR PASSIVE SYSTEMS

摘要

The deployment of passive safety systems in nuclear applications especially in advanced nuclear power reactors (both evolutionary and innovative designs) is on the rise. This can be linked to the simplicity, economic and less dependence on human interventions attributes of those passive systems. The reliability of nuclear passive systems especially the thermal-hydraulic ones is influenced by parameters which are interdependent in reality. As a result, the need to critically consider the synergetic effects of determinants of reliability of the thermal-hydraulic nuclear passive systems is of utmost importance. Reliability methodologies are now being modified by factoring the dependency nature of those determinants into reliability analysis to obtain more realistic and accurate results. This paper thus focused on the introduction of more influencing factors in parameters dependency consideration of phenomenological reliability using multivariate distribution analysis. A passively water cooled steam generator was used to demonstrate the interdependency effects of some selected critical parameters. The results obtained justified the need for considering the dependency effects of these parameters influencing the reliability of thermal-hydraulic passive systems. In addition, the research issues on dependency consideration of influencing parameters in evaluation of reliability of these nuclear passive systems were also discussed.