富集硼酸对压水堆一回路腐蚀产物沉积的影响研究  

Study on the Influence of the Enriched Boric Acid on CorrosionProduct Deposits in PWR Primary System

作　　者：高希龙[1] 景福庭[1] 刘嘉嘉[1] GAO Xi-long;JING Fu-ting;LIU Jia-jia(Key Laboratory of Reactor System Design Technology,Nuclear Power Institute of China,Chengdu,Sichuan Prov.610041,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,四川成都610041

出　　处：《中国核电》2020年第4期428-432,共5页China Nuclear Power

摘　　要：在压水堆核电厂中,通常在冷却剂添加天然硼酸来控制剩余反应性。在寿期初,硼浓度相对较高,特别是在核电厂实施长循环燃料管理后,较高的硼(硼酸)浓度会降低一回路的pH并增加一回路管道和设备的腐蚀速率,腐蚀产物的增加会降低燃料元件与冷却剂之间的传热效率,同时增加核电厂的辐射风险。国外研究发现,在核电厂反应堆中采用富集硼酸可以改善一回路水化学条件,抑制包壳材料的腐蚀,并降低腐蚀产物的活化和迁移。本文开展了富集硼酸对压水堆一回路腐蚀产物沉积的影响研究,通过提高10 B的富集度,对一回路腐蚀产物在燃料元件上沉积质量,以及在管道和设备上沉积的活化腐蚀产物活度的影响进行了分析。研究表明,适当提高10 B的富集度,会降低沉积在燃料元件上的腐蚀产物的总质量,有助于燃料元件包壳与冷却剂之间热交换,减少功率损失;同时,随着10 B的富集度的提高,也会降低沉积在管道和设备上的活化腐蚀产物的活度,从而有助于降低核电厂的辐射剂量。To control excess reactivity,natural boric acid is used in PWRs as chemical shim.As the boric acid concentration is relatively high at the beginning of life(BOL),especially with the implement of long cycle fuel management,the high boric acid concentration will lower the pH,increase the corrosion rate of materials,and result in the increase of the radiation risk and the decrease of heat transfer efficiency between fuel rod and coolant.The study abroad finds that,the water chemistry improves and the corrosion will be restrained with the application of enriched boric acid(EBA).This paper analyzes the influence of EBA on deposits of corrosion product in PWR.The study shows that EBA can reduce the mass of corrosion product deposits on the fuel rod and lower the activity of corrosion product deposits on pipes,contributing to the heat transfer between fuel rod and coolant and lower radiation field.

关 键 词：压水堆 富集硼酸 腐蚀产物 沉积 

分 类 号：TM623[电气工程—电力系统及自动化]