Damage development analysis of the whole nuclear power plant of AP1000 type under strong Main-aftershock sequences

This paper focuses on the seismic damage analysis of the whole nuclear power plant (NPP) of AP1000 type during strong seismic sequences. For that purpose, seven synthetic main-aftershocks with three-direction inputs are considered in this study, and the three-dimensional model of whole NPP of AP1000 type suffering from the selected seismic sequences is established. The results indicate that (i) the damage aggravation effect is substantially caused by considering the reinforced concrete auxiliary building (RCAB) for the NPP and is mainly concentrated at the upper intersection between the reinforced concrete shield building (RCSB) and RCAB, especially during beyond design basis earthquake sequences, (ii) concrete damage are greatly developed with increasing PGA, and aggravated by the aftershock, concrete tension damage is more severe than compression damage under earthquake sequences, (iii) the structure residual displacement in three directions are increased by the aftershock, (iv) the average value of the sequence seismic damage dissipation energy is 1.14-1.27 times that of a single earthquake, and the increasing trend of the times is linear.

Automated summary

This study found that the reinforced concrete auxiliary building significantly aggravates the damage of the nuclear power plant during beyond design basis earthquake sequences, and concrete damage increases with PGA. Additionally, aftershocks lead to an increase in residual displacement of the structure, and the dissipation energy of seismic damage in sequences shows a linear increasing trend.