基于一致风险谱的某核电安全壳地震风险分析

In order to provide the reference for the revision of the consistent risk-based seismic design method for the structures of nuclear power plants in China,the seismic risk analysis method for the containment of nuclear power plants in China based on the consistent risk spectrum was investigated. By deriving the analytical model of seismic risk and summarizing the theory and method of generating consistent risk spectra in the " Seismic Design Criteria for Structures, Systems,and Components in Nuclear Facilities" (ASCE/ SEI 43) published by the American Society of Civil Engineers(ASCE),the uniform hazard spectra and the consistent risk spectra were generated;the seismic risk of the example structure was obtained by adopting the analytical risk function. The risk based on the first translation period is greater than the risk based on the second translation period;the mean seismic risk is greater than seismic risk with the 50% confidence and less than seismic risk with the 95% confidence,which indicates that the mean seismic risk results are well comparable to a seismic risk with less than the 95% confidence;the mean seismic risk results are on the unconservative side if the risk criterion is screened by using the seismic risk with 95% confidence;the consistent risk spectra given by the two editions of ASCE/ SEI 43 are the same for structures,systems,and components that are in the seismic design subgroup 5(SDC 5) such as nuclear islands;the risk level of Chinese containment is much lower than the target risk in ASCE 43 code under the consistent risk spectrum. The results show that Chinese nuclear power containment has large design safety margin and has the smaller seismic risk than the target risk in the ASCE 43 code.