Resilience-based seismic design for nuclear island building: An innovative hybrid passive control system

The Fukushima nuclear incident has heightened global concerns about the safety of nuclear facilities, the imperative to enhance the seismic resilience of nuclear power plants (NPPs) has become a pivotal aspect of nuclear safety. This study introduces an innovative hybrid passive control system that integrates three-dimensional (3D) base isolation technology with periodic isolation walls, aiming to bolster the seismic resilience of NPPs against very rare earthquakes. Furthermore, a complete and viable computational procedure was developed to study the nonlinear soil-structure interaction effects with high-precision wave motion analysis. Finally, the efficacy of the innovative control system to improve the seismic resilience of large-scale nuclear island buildings situated on non-rocky sites was assessed. The findings reveal that the system significantly mitigates the distribution of damage to NPPs during very rare earthquake scenarios. Compared to non-isolated NPP, the adoption of a hybrid passive control system reduces structural damage dissipation energy by 97.73 %. The system augments the effectiveness of 3D base isolation technology in reducing dynamic responses; specifically, the floor response spectra at the top position of the nuclear island building in the X, Y, and Z directions were lowered by 62.33 %, 52.03 %, and 84.12 %, respectively. Moreover, the system considerably reduces the deformation of the 3D isolation bearings. The innovative hybrid passive control system helps to enhance the seismic resilience of NPPs.