The simulation and study of ELAP event with URG and FLEX mitigation strategies for PWR by using TRACE code

Abstract

AbstractIn this research, TRACE code with the interface SNAP was used to evaluate and simulate the postulated Extended Loss of AC Power (ELAP) accident in Maanshan Nuclear Power Plant (NPP). This study is to determine whether Reactor Coolant System (RCS) water level will be below Top of Active Fuel (TAF) while the 5th diesel generator and gas turbines are all disabled when the accident occurred. The scenario and assumptions of postulated ELAP in this research are referred to the WCAP-17601-Pt and NUREG-1953 reports. Additionally, this study will run a base case without any mitigation strategy and four cases with multiple mitigation strategies to analyze the effectiveness of URG and FLEX strategies. According to the analysis results of TRACE, it can be found that all four cases with mitigation strategies can keep RCS water level above TAF. This indicates that URG and FLEX strategies can ensure the safety function of reactor.