乏燃料池壁面孔洞式缺陷水下修复工艺  

Underwater Repair Technology for Hole Defects in the Wall Face of a Spent Fuel Pool

作　　者：赵友亮 朱加雷[1] 周飞鸿 赵晓鑫 赵志博 赵亮 张光亮 郭方涛 黄钰珊 ZHAO Youliang;ZHU Jialei;ZHOU Feihong;ZHAO Xiaoxin;ZHAO Zhibo;ZHAO Liang;ZHANG Guangliang;GUO Fangtao;HUANG Yushan(School of Mechanical Engineering,Beijing Institute of Petrochemical Technology,Beijing 102617,China)

机构地区：[1]北京石油化工学院机械工程学院,北京102617

出　　处：《中国表面工程》2025年第1期228-240,共13页China Surface Engineering

基　　金：国家自然科学基金联合基金重点支持项目(U22B20127);北京市科技计划重点项目(KZ202210017023);北京市属高校分类发展项目(11000023T000002199202);北京市属高等学校高水平科研创新团队建设支持计划项目(BPHR20220110)。

摘　　要：核电站乏燃料池因长期服役,其底面与壁面的不锈钢覆板会产生裂纹、孔洞等缺陷,导致放射性液体泄漏,对环境产生恶劣影响,影响核电站的安全运行。传统潜水员手工焊接或核电站停运维修都难以满足当下维修需求。采用自主搭建的水下TIG(钨极惰性气体保护焊)填丝焊接试验系统,针对乏池壁面覆板焊缝大面积的裂纹和孔洞式缺陷,采用尺寸为80 mm×80mm×4 mm的方形补板,通过补板与乏池壁面覆板原始焊缝待修复位置对正贴合,将补板焊接分解为横向位置与立向位置的焊接。试验设备选用KEMPPI TIG焊机和福尼斯KD7000送丝机,分别开展水下环境与空气环境横向位置和立向位置的TIG填丝焊接工艺试验。对比分析两种环境下焊接接头的显微组织、化学成分和物相组成。结果表明:因熔池快速冷却导致水下环境焊缝截面尺寸略小于空气环境;水下环境δ铁素体含量与硬度高于空气环境,并在羽毛状铁素体聚集处出现显微硬度最大值;水下环境焊缝晶粒尺寸略大于空气环境,耐腐蚀性能略低于空气环境但相差不大,两种环境下焊缝金属均析出Cr元素,提升其耐腐蚀性能,水下补板焊接修复成形质量可与空气环境相媲美,满足乏池覆板壁面位置的修复要求。研究结果可为水下环境304L不锈钢覆板的防护与修复提供参考。Due to long-term service,the stainless steel cladding on the bottom and wall of a spent fuel pool in a nuclear power plant can cause cracks,holes,and other defects,leading to the leakage of radioactive liquid and negatively affecting the environment.This in turn affects the safe operation of the plant.Traditional manual welding by divers or shutdown maintenance of nuclear power plants cannot meet current maintenance requirements,and local dry automatic underwater welding maintenance is a development trend.Compared with the underwater welding of the bottom cover plate,the pressure difference in the wall position due to drainage and the effects of gravity on the molten pool are more obvious.The welding and drainage process for underwater repair of the wall cover plate is more difficult to implement,significantly increasing repair difficulties.Therefore,this study explores and optimizes the local dry drainage and welding process of a wall cladding.To simulate the underwater repair of a spent fuel pool wall cladding in a nuclear power plant,a local dry underwater tungsten inert gas(TIG)shielded welding repair system was developed that includes a mobile positioning mechanism,TIG power supply,underwater TIG welding drainage device,control system,wire feeder,and experimental pool.The local dry underwater TIG welding drainage device has high adaptability in multiple positions and is suitable for welding repair in underwater environments at wall positions.The study employed a self-built underwater TIG wire filling welding test system and used a square repair plate of 80 mm×80 mm×4 mm to address the large area of cracks and hole defects in the weld seam of the spent fuel pool wall cladding.After the repair plate was aligned with the original weld seam of the spent fuel pool wall cladding to be repaired,the welding of the repair plate was decomposed into horizontal and vertical positions for welding.A KEMPPI TIG welding machine and Funis KD7000 wire feeder were used as experimental equipment to conduct TIG wire filling we

关 键 词：局部干法 水下钨极惰性气体保护焊(TIG)填丝焊接 显微组织 化学成分 物相组成 电化学腐蚀 

分 类 号：TG456[金属学及工艺—焊接]