Seismic Isolation Reliability Analysis of a Lead-Bismuth Small Modular Reactor

Abstract

Abstract Seismic isolation technology has been proven to significantly reduce the seismic response of the structures, systems and components (SSCs) in a nuclear power plant (NPP), improve the seismic reliability and safety of nuclear power plants, reduce construction costs, and shorten construction periods. Reliability analysis of a lead-bismuth small modular reactor (SMR) with a seismic isolation design was conducted: ANSYS APDL was used to establish a finite element model of the SMR, modal analysis was performed on the isolated SMR, and the dynamic characteristics of the SMR was obtained; seismic design spectrum proposed by Newmark-Hall was used as input for seismic spectrum analysis, and the seismic response evaluation of SMR was carried out; ANSYS PDS (Probability design system) module was used to carry out probabilistic calculation of the above process, and the calculation considers the uncertainties in the physical parameters of structure materials and isolation bearings, geometric dimensions and seismic response spectrum, the random variables were sampled by the Latin hypercube sampling method in the Monte Carlo method, and failure probability of isolated SMR and non-isolated SMR were obtained through mathematical statistics. The calculation results show that the seismic isolation design can significantly reduce the failure probability under earthquakes and improve the safety of lead-bismuth SMR.