大亚湾核电站反应堆厂房楼层反应谱分析评估

Re-evaluation of floor response spectra of reactor building for Daya Bay NPP

大亚湾核电站核岛厂房的抗震分析遵循技术输出国-法国M310型机组的土建技术规范RCC-G, 采用简化的阻抗函数法计算地基岩土的作用。根据大亚湾厂址的地基岩土特点,拟采用更为精确的三维连续半空间边界子结构法来考虑地基岩土的作用,并与原设计进行对比。另外,在原设计中采用多组时程作为地震输入,取各组计算结果的平均值作为设计值的基础(称为“平均”法)。在研究中基于相同的时程,拟分别采用“平均”法和更为常用的“包络”法,处理多组时程的响应。基于上述两方面,通过反应堆厂房的地震响应计算,得到核电站系统设备重要的设计基础数据-楼层反应谱(FRS),并将计算的楼层反应谱同设计谱进行比较,从而对设计方法及其结果进行评估,为电站的抗震设计裕量评估和安全管理提供可资参考的结论。

The seismic analysis of nuclear island of Daya Bay Nuclear Power Plant（NPP） was just in accordance with the approaches in RCC-G standard for the model M310 in France, in which the simplified impedance matrix method was employed for the consideration of soil＇s function. In this paper the more sophisticated 3D half-space continuum impedance method based on the Green functions is used to analyze the function of soil. In addition, multi-group of input time histories was used in the seismic response analysis in the existing design and their average of responses .for each group was taken as the design basis. The same multi-group of input time histories was used in the seismic response analysis in this study, but the average and enveloped value of responses for each case are calculated respectively to account for the uncertainty of input motions. Focused on the above two issues, the seismic responses of the reactor building are calculated and the floor response spectra （FRS）, a very important data for the design of nuclear system and equipment, are generated and then compared with the corresponding design values, so that the evaluation and discuss on the design method and results are conducted. Some useful conclusions hopefully to provide some important references to the assessment of seismic safety margin for the NPP in operation are taken.