PIRT Research on RCCA Ejection Accident

Abstract

Phenomenon Identification and Ranking Table (PIRT) mainly refers to: for the specified accident type of the specified power plant, analyze and identify the phenomena and processes existing in this accident, and sort them according to their impact on the main safety criteria to form PIRT. Many PIRT studies have been performed for LOCA, while there is few PIRT studies for Reactivity Initiated Accident (RIA). Thus, PIRT for RCCA ejection accident (a quintessential RIA) of a three-loop PWR is developed in this paper. Firstly, the safety criterion of RCCA ejection accident is obtained by the technical analysis of regulations and standards. Then, the main phenomena and key parameters of the RCCA ejection accident are obtained by analyzing the process of transient. Finally, the impacts of each key parameter on the calculation results are quantitatively evaluated by single variable sensitivity analysis, and the importance of each parameter is judged. Based on the results, the PIRT of RCCA ejection accident is obtained. In addition, the PIRT is applied to DNB ALARP analysis in RCCA ejection accident, of which the evaluation result is successfully used to confirm the validity of ranking in the PIRT. This study provides a basis for the methodological optimization and conservative demonstration of subsequent RCCA ejection accident.