基于烈度指标的核电厂地震预警停堆参数研究

核电厂在遭遇超设计基准地震时需要考虑安全停堆,以避免造成核泄漏事故。采用地震动的峰值加速度参数(PGA)作为判别停堆的参数具有一定的局限性,PGA参数不能反映地震动的频谱和持时特征,因而可能引起不必要的停堆。针对此问题,基于我国本土大量实际强震记录,遴选出7种典型的工程相关地震动参数,进而基于地震烈度指标,分析发现地震动的标准累计绝对速度参数能更好地表征地震对核电厂的整体潜在破坏能力,适合作为判别停堆的参数,然后提出两种确定预警参数阈值的方法,最终建议考虑我国强震数据特征的核电厂判别停堆的预警参数阈值,为我国核电厂的地震安全停堆参数的确定提供了参考。

Analysis of the Earthquake Early-warning Parameters for NuclearPower Plants Shutdown Based on the Intensity Measure

A safety shutdown is required to avoid a nuclear leak when a nuclear power plant encounters an earthquake that exceeds the design earthquake. The peak ground acceleration (PGA) is conventionally used as the early-warning parameter for nuclear power plants shutdown. However, the PGA cannot reflect the characteristics of frequency and duration of ground motion records; therefore, unnecessary shutdown of nuclear power plants may occur. To solve this problem, it is necessary to conduct further research on the selection of early-warning ground motion parameters. In this paper, based on a large amount of actual strong motion records in China, seven typical ground motion parameters are selected and then compared based on the seismic intensity measure. The results show that compared with other parameters, the standard cumulative absolute velocity (CAV_STD) can better reflect the potential of an earthquake to damage a nuclear power plant; thus, it can be appropriately used as the early-warning parameter for nuclear power plant shutdown. Moreover, two methods are proposed to determine the threshold values of CAV_STD. The threshold value of CAV_STD is suggested by considering the characteristics of strong motion records in China. The results can provide reference for the determination of seismic safety parameter of nuclear power plant shutdown in China.