ROLE OF MODELING IN 2ND-MOMENT RELIABILITY EVALUATION FOR SEISMIC SAFETY OF REACTOR BUILDINGS

Evaluation of second-moment reliability indices for seismic safety ass essment requires appropriate modelling. The advantage of a simplified approach such as second-moment reliability based on a log-normal distr ibution postulation is the transparency of each process of the evaluat ion. However, the models assumed in the evaluation process have to be reasonably accurate and physically meaningful. Simplified models for s eismic hazard, spectral characteristics of input motions, inelastic re sponse behaviour and resistance evaluation are introduced and their ap propriateness for the seismic safety evaluation of a nuclear power pla nt building, often taken as a typical important structure, is discusse d.