Comparative evaluation of response reliability during accidents in light water reactors and fast reactors

Abstract

To identify functions and facilities that are critical for ensuring safety in advanced reactors, for which only a limited usage history is available, it is necessary to consider the characteristics of each reactor type by utilizing more risk-related information. In this study, we compare the response capability during an accident for light water reactors and fast reactors to quantitatively evaluate the impact of the reactor type on resilience. A resilience evaluation procedure is developed for assessing the response margin and response reliability of a nuclear power plant during an accident; this procedure was then applied to a simple pressurized-water reactor and a sodium-cooled fast reactor plant model using an accident scenario involving an earthquake that generated a leakage of coolant from the primary heat-transport system. Our research indicated a relatively large difference between the response reliability with respect to time for the two reactor types.

Keywords

• risk
• resilience
• response reliability
• safety assessment
• accident management
• light water reactor
• fast reactor