核电机组检修期间一回路硫酸根离子含量控制研究

Study on Sulfate Content in the First Circuit of Nuclear Power Unit During the Overhaul Period

压水堆核电厂在停堆大修期间,一回路冷却剂中硫酸根离子会异常升高,其原因是由于冷却剂受到较强的辐射而分解产生H_(2)O_(2),树脂的交联结构受到破坏导致阳树脂的磺酸基脱落并在冷却剂中继续氧化而引起的。以方家山核电机组为研究对象,通过监测停堆期间的水化学数据,并进行了树脂氧化稳定性试验和失效机理分析,探讨了引起硫酸根离子升高的原因和过程,提出通过使用高交联度的净化树脂可以解决大修期间水化学异常的问题。

During the shutdown and overhaul of PWR nuclear power plant,sulfate ions in the primary-loop coolant will increase abnormally,which is caused by the decomposition of H_(2)O_(2)due to the strong radiation of the coolant,the destruction of the crosslinking structure of the resin causes the sulfonic groups of the cationic resin to fall off and continue to oxidize in the coolant.In this paper,Fangjiashan nuclear power plant is taken as the research object,through monitoring the hydrochemical data during shutdown,the oxidation stability test of resin and the failure mechanism analysis are carried out,and the cause and process of the increase of sulfate ion are discussed,it is suggested that the problem of water chemical abnormality during overhaul can be solved by using high cross-linking purification resin.