Seismic evaluation of base-isolated nuclear power plants with various tuned inerter dampers

Abstract

This paper investigated the seismic performance of base-isolated nuclear power plants (NPPs) incorporating various tuned inerter dampers (TIDs), specifically focusing on the series inerter system (SIS), series-parallel inerter system-I (SPIS-I), and series-parallel inerter system-II (SPIS-II). These vibration control strategies were applied to the Hualong pressurized reactor 1000 (HPR1000) NPP with a base-isolated double-layer containment. The equations of motion of base-isolated NPP with different TIDs were derived, and the seismic response variances of the HPR1000 NPP with the three TIDs under white noise excitation were obtained. Furthermore, the parameters of the three TIDs were optimized by minimizing the dynamic response of the NPP. The optimization results of dynamic response demonstrate that the SPIS-II reduces relative displacement of the base-isolated NPP significantly, while the SPIS-I has a better performance in minimizing absolute acceleration. Besides, the SIS shows a better vibration suppression effect when the inertial coefficient is relatively small. Furthermore, the detailed finite element method (FEM) models of the HPR1000 NPP with various vibration control strategies were established for validating the efficiency of the three TIDs. When these FEM models are subjected to safe-shutdown earthquake (SSE) loadings, the results demonstrate that TIDs reduce the seismic response of the HPR1000 NPP effectively. The novelty of this paper is presenting the rationality of the optimization results of the three TIDs, and providing the guidance for practical engineering by three-dimensional numerical modelling of HPR1000 structures. Noted that both vertical seismic motion and soil-structure interaction are not considered in this study, which requires a further investigation.