核设备抗震鉴定试验中功率谱密度检验方法分析评估

Analysis of Inspection Methods for Power Spectral Density in Seismic Qualification Test of Equipment in Nuclear Power Plants

为满足核设备抗震鉴定试验中输入运动的功率谱密度(PSD)要求,基于对规范背景和目标PSD算法的调研以及典型算例的对比分析,对PSD的检验方法进行分析评估。结果表明,检验PSD最为直观的方法即对比输入运动PSD与目标PSD;根据各类目标PSD算法的结果精度、保守性及其规范依据,推荐使用2014版美国核管理委员会标准审查大纲(SRP)3.7.1节附录B中人工合成时程的方式来计算目标PSD:虽然该算法通常适用于核电厂的厂址设计反应谱,但对于设备抗震鉴定反应谱,仅需将人工合成时程的目标反应谱替换为鉴定反应谱即可;采用本文推荐方法计算目标PSD时,设备抗震鉴定输入运动的PSD检验应与SRP 3.7.1保持一致,即在0.3 Hz到目标反应谱的最高截断频率范围内包络目标PSD的70%。

In order to meet the power spectral density(PSD) requirements of the input motion in the seismic qualificaiton test of equipments for nuclear power plants, the inspection method of PSD is analyzed and evaluated in this paper, based on the study on the background of the standards and the target PSD algorithm and the comparative analysis of typical examples. The results show that the most intuitive method of PSD check is to compare the PSD for input motion with the target PSD. According to the accuracy and conservativeness of the results of different types of methods for developing target PSD, it is recommended to use the synthetic time-history method in Appendix B of U.S. NRC SRP 3.7.1(2014) to calculate the target PSD. Although this method is generally applicable to the site-specific response spectra of nuclear power plants, it is also applicable to the test response spectra(TRS) for seismic qualification by replacing the target response spectra with TRS in the process of the synthetic time history. When using the proposed method to calculate the target PSD, the PSD check for the seismic identification input motion should be consistent with SRP 3.7.1, which envelops 70% of the target PSD between 0.3 Hz and the upper bound frequency of the target response spectra.