Diversification of Seismic Design of Components of Nuclear Power Plants with Improvement of Static Seismic Coefficient considering Ductility Factor
長澤 和幸 Kazuyuki NAGASAWA 飯島 唯司 Tadashi IIJIMA 奈良林 直 Tadashi NARABAYASHI
Design Basis Earthquake Ductility Factor Seismic Design Static Coefficient
In Japanese regulatory guide for seismic design of nuclear power plants, the combination of the design by the dynamic response analysis with design basis earthquake and the design by the design basis seismic static coefficient (DSC) is required. This paper proposes new static seismic design methodology with newly defined DSC derived from elastic-plastic time historical seismic response analysis of components and allowable ductility factor to prevent damage to components. The process of the seismic response analysis to obtain the ductility factor considering load-deflection characteristic of components and definition of the allowable ductility factor based on the actual experiences are also described. Furthermore, trial analysis of the DSC for actual nuclear facility of Kashiwazaki-Kariwa Nuclear Power Station is conducted. It is expected that the new method will help diversify the existing seismic design system, which is based on equivalent elastic design, as well as increase the reliability of seismic design to deal with the uncertainty of the seismic motion.