The research committee of Chuetsu-oki earthquake influences to Kashiwazaki-Kariwa Nuclear Power Station. Seismic margin on nuclear power station design

According to Chuetsu-oki earthquake in 2007, there is no significant damage on Kashiwazaki-Kariwa Nuclear Power Station's components, even though over size earthquake compare to design use had happened. This paper describes outline how to design a nuclear plant and evaluate its seismic safety, then try to make clear what safety margins there are and how much they are. Safety margins are in Safety factors apply to Load under seismic and Strength of materials covering uncertainty, Modeling of seismic integrity analysis, Damping factors, Strain-Stress diagram, and others. Recently the design method of LRFD (Load Resistance Factor Design) is studied to apply to structural design instead of traditional method. (author)