The Research on Seismic Margin Analysis for Piping in Pressurized Water Reactor Nuclear Power Plant

According to feedback of Japan's Fukushima nuclear accident, beyond design basis earthquake would cause disastrous consequences for nuclear power plant. Referring to lessons learnt from Fukushima nuclear accident and nuclear power plant safety requirements, the seismic margin analysis (SMA) evaluation method was used for beyond design basis earthquake assessment for Pressurized Water Reactor nuclear power plants. According to the basic idea of FA method (fragility analysis method) and empirical data, SMA analysis of piping was explored in this paper by taking containment spray system piping as an example. The analysis result shows that the HCLPF (high confidence and low probability of failure) seismic level is 30.54 ft/s(2), meet the requirements of review level earthquake 10.74 ft/s(2).