Improved response factor methods for seismic fragility of reactor building

A seismic probabilistic risk assessment (PRA) method has been applied to ev aluate the safety of nuclear reactor buildings during earthquakes. Improvem ent was made to two methods (based on linear response and based on non-line ar response) of fragility analysis in seismic PRA. The conventional method, which is based on linear response, considers increases of seismic capacity implicitly, using the non-linear behaviour of the structure. We described how to evaluate the capacity increase factor for the linear response method . Secondly, we proposed a method based on the non-linear response and a str atified two-point estimation method which can efficiently evaluate the vari ability of non-linear responses. We applied the two method to a PWR-type nu clear reactor building and ascertained that these method are useful and eff ective. (C) 1998 Elsevier Science S.A. All rights reserved.