Seismic Margin Analysis of In-Service Nuclear Power Plant

After Fukushima event, extra weight has given to the works of implementing safety inspection and evaluation which attempt to evaluate the safety margins of NPPs under beyond design basis conditions as well as to bring forward some improving measures. The aiming of Seismic Margin Analysis (SMA) is to evaluate the seismic capability when the beyond design basis earthquake happens. Through widely study of methods used in SMA abroad, a conclusion can be made that the EPRI SMA method is ideal for the in-service NPPs with less PSA model and data, therefore, reasonably proper to the Qinshan Phase II SMA project. The analysis result showed that the Qinshan Phase II NPP can resist SME-level earthquake (0.225 g) which is 1.5 times of SSE.