DEVELOPMENT OF EVALUATION METHOD FOR SEISMIC ISOLATION SYSTEMS OF NUCLEAR POWER FACILITIES - SEISMIC FRAGILITY EVALUATION OF EQUIPMENT-

摘要

This paper provides a part of series of 'Development of Evaluation Method For Seismic Isolation Systems of Nuclear Power Facilities'. This part describes the seismic fragility evaluation for equipment of the seismic isolated plants. In order to respond the regulatory requirement of residual risk evaluation, a research on residual risk evaluation of the seismic isolated plants is proceeding as a part of the Japan national project of seismic isolation. As efforts for this research, realistic capacities of seismic isolators are studied by braking tests of full-scale seismic isolation systems and of crossover piping are studied by shaking tests of scaled model and static tests by simultaneous loads of in-plane and out-of-plane. Fragilities of the seismic isolators and crossover piping are evaluated based on the results of these studies. Seismic response characteristics of the seismic isolated buildings show strong non-linearity and large displacement because of the vibration characteristic of the seismic isolation system. Therefore, response characteristics specific to the seismic isolated buildings such as non-linear response and relative displacement between isolated building and non-isolated building shall be considered in the fragility evaluation methodology for equipment of the seismic isolated plants. This paper focuses on the seismic fragility evaluation of equipment of the seismic isolated plants considering the relative displacement and non-linear response of the buildings. Representative equipment of isolated plants are selected and fragility evaluations of the equipment are performed based on the results of the response analysis of buildings and crossover piping. Result of seismic PRA using fragility values obtained in this study is reported in other part of this series of papers.