Phenomena identification Ranking Table (PIRT) study for suppression containment of small modular reactor using new methodology

Abstract

The Phenomena Identification and Ranking Table (PIRT) is a significant method for analyzing the safety of nuclear reactors. It helps researchers identify important phenomena within the reactor, enabling a focused and appropriate simplification of accident scenarios during the study. However, traditional PIRT methods often rely on experts' subjective opinions to rank phenomena’ importance and knowledge level, potentially distorting the PIRT results. This paper proposes a new PIRT method inspired by literature evaluation techniques used in the medical and healthcare field, which can be more objective. This new method utilizes a literature evaluation framework instead of relying solely on expert judgments, resulting in a more objective assessment of the phenomena’ importance and knowledge level. This study applies the new method to a simplified small modular reactor with a suppression containment system. Following a Loss of Coolant Accident (LOCA), the suppression containment can effectively suppress temperature and pressure increases, ensuring containment integrity. Relevant PIRT tables and a knowledge-level structure are obtained using the new method.