核电厂安全壳地坑过滤器化学效应试验研究

核电厂失水事故工况下，化学效应可能引起地坑过滤器过度堵塞，影响应急堆芯冷却系统或安全壳喷淋系统的再循环功能，导致堆芯、安全壳丧失冷却，威胁核电厂的安全。本文以秦山核电厂二期扩建工程为研究对象，开展失水事故工况下潜在化学产物对地坑过滤器压头损失的影响研究。结果表明，秦山核电厂二期扩建工程安全壳内含Al材料和保温材料在地坑环境中会析出Al、Si，Al、Si元素在地坑介质降温过程中形成了化学沉淀物，化学沉淀物会在地坑过滤器碎片床上沉积，堵塞碎片床流道，缩小碎片床孔隙率，导致地坑过滤器压头损失增加。因此，秦山核电厂二期扩建工程失水事故后存在化学效应，在地坑过滤器性能评估、下游效应分析中应予以考虑。 

Experimental Study on Chemical Effects of Nuclear Power Plant Sump Strainer

Under the loss of coolant accident in nuclear power plants, the blockage of sump strainers may be resulted from chemical effects, which will affect the recirculation function of the emergency core cooling system or the containment spray system, disabling the cooling of the core and containment, and threatening the safety of nuclear power plants. Study on the effects of potential chemical products on sump strainer head loss after the loss of coolant accident in Qinshan PhaseⅡExtension Project was conducted. The results showed that the alumina-bearing material and the insulation material released aluminum and silicon in the sump environment, and that aluminum and silicon formed chemical precipitation and deposited on the debris bed. This can result in the blockage of the debris bed and the reduction of the porosity, and increase the head loss of the sump strainer. There are chemical effects after loss of coolant accident in Qinshan Phase Ⅱ Extension Project, and it should be considered in the sump strainer performance evaluation and downstream effect analysis.