压水堆核电厂二回路系统溶解氧含量的控制策略  

Dissolved Oxygen Content Control Strategy in Secondary Loop System of Pressurized Water Reactor Nuclear Power Plant

作　　者：孙云[1] 宋利君[1] 王力[1] 方军 林根仙[1] 肖艳 刘灿帅 SUN Yun;SONG Lijun;WANG Li;FANG Jun;LIN Genxian;XIAO Yan;LIU Canshuai(Suzhou Nuclear Power Research Institute Co.,Ltd.,Suzhou 215004,China)

机构地区：[1]苏州热工研究院有限公司,苏州215004

出　　处：《腐蚀与防护》2023年第9期94-100,共7页Corrosion & Protection

基　　金：中广核集团尖峰计划项目(R-2020SZSO53TF);江苏省自然科学基金(BK20220257)。

摘　　要：采用失重法和模拟腐蚀试验研究了溶解氧含量及联氨与溶解氧含量比值对压水堆核电厂二回路系统材料流动加速腐蚀(FAC)的影响,并结合经验反馈,给出了二回路系统溶解氧含量的控制策略。结果表明:在0~30μg/kg溶解氧范围内,溶解氧含量对凝结水管道材料A515碳钢均匀腐蚀的影响不大,低压加热器至除氧器之间的管道材料P11低合金钢的FAC速率随溶解氧含量的升高而减小;由于溶解氧含量较低,联氨与溶解氧含量比值超过了8,因此联氨含量的提高对该钢腐蚀速率的影响较小;在2 mg/kg的低溶解氧条件下,690TT合金的裂纹扩展速率(CGR)较低,在饱和溶解氧条件下,690TT合金的CGR提高了1.08~3.53倍;建议采取分段控制的方式控制压水堆核电厂二回路系统的溶解氧含量,将凝结水至除氧器之间的溶解氧质量分数提高至5~30μg/kg,将除氧器至蒸汽发生器之间的溶解氧质量分数控制在5μg/kg以下,并加入联氨,使联氨与溶解氧含量比值维持在5~8以上。The effects of dissolved oxygen content and the content ratio of hydrazine to dissolved oxygen content on material flow accelerated corrosion(FAC) in the secondary loop system of pressurized water reactor nuclear power plant were studied by weight loss method and simulated corrosion test.Combined with empirical feedback,the control strategy of dissolved oxygen content in the secondary loop system was given.The results showed that in the range of 0-30 μg/kg dissolved oxygen,the dissolved oxygen content had little effect on the uniform corrosion of the condensate pipeline material P11 carbon steel,and FAC rate of the steel between the low pressure heater and the deaerator decreased with the increase of dissolved oxygen content.Due to the low dissolved oxygen content,the content ratio of hydrazine to dissolved oxygen content exceeded 8,so the increase of hydrazine content had little effect on the corrosion rate of P11 low alloy steel.Under the condition of low dissolved oxygen of 2 mg/kg,the crack growth rate(CGR) of 690TT alloy was lower,and the CGR of 690TT alloy was increased by 1.08-3.53 times under the condition of saturated dissolved oxygen.It was suggested that the dissolved oxygen content in secondary circuit system of PWR nuclear power plant should be controlled by subsection control.The mass fraction of dissolved oxygen between condensate water and deaerator should be increased to 5-30 μg/kg.The mass fraction of dissolved oxygen between deaerator and steam generator should be controlled below 5 μg/kg,and hydrazine should be added to maintain the content ratio of hydrazine to dissolved oxygen above 5-8.

关 键 词：压水堆 二回路系统 溶解氧 流动加速腐蚀(FAC) 

分 类 号：TM623[电气工程—电力系统及自动化]