Risk Assessment of Seismic Loss-of-offsite-power for High Temperature Gas-cooled Reactor

Seismic loss-of-offsite-power (SLOOP) is a typical seismic initiating event of nuclear power plant (NPP). In this paper, SLOOP risk assessment model of high temperature gas-cooled reactor (HTR) was generated through application of seismic probabilistic safety analysis (SPSA) methods. Studies ranged from analyzing the SLOOP accident developing scenarios, screening the seismic equipment list (SEL) with conducting the walkdown to integrating the tasks for construction of SLOOP model. As the risk level of HTR under SLOOP accident, the radioactivity release above the dosage of the risk acceptance criteria for HTR (the probabilistic safety goal) was then obtained and analyses for seismic interval, minimum cut set and importance measure were made. The results provide useful reference for the methods implementation, modeling assumption and process analysis of SPSA for the HTR.