破损燃料棒二次氢化行为观察与分析  

Observation and Analysis of Secondary Hydriding Behavior of Failure Fuel Rod

作　　者：钱进[1] 郭一帆[1] 王鑫[1] 褚凤敏[1] 郭丽娜[1] 卞伟[1] 梁政强[1] QIAN Jin;GUO Yifan;WANG Xin;CHU Fengmin;GUO Lina;BIAN Wei;LIANG Zhengqiang(Division of Reactor Engineering Technology Research,China Institute of Atomic Energy,Beijing 102413,China)

机构地区：[1]中国原子能科学研究院反应堆工程技术研究部,北京102413

出　　处：《原子能科学技术》2020年第8期1487-1493,共7页Atomic Energy Science and Technology

基　　金：国家科技重大专项基金资助项目(2019ZX06004009)。

摘　　要：燃料棒在堆内运行时,由于初次破口会导致包壳发生二次氢化现象,二次氢化是导致燃料棒发生严重破损的重要因素。针对实际工况下的破损燃料棒,在中国原子能科学研究院燃料与材料检验设施(303热室)上开展了相关辐照后检验,并采用热室金相手段,对燃料棒二次氢化行为进行了观察分析。结果表明:二次氢化破口有明显的氢化肿胀现象;氢化物分阶段从内壁扩散到外壁,并形成“日爆”现象;二次氢化部位芯块温度明显升高,并会导致芯块气孔迁移、芯块晶粒长大、柱状晶生长等现象发生;相比未破损棒,破损棒二次氢化部位水侧氧化膜厚度有增加现象,但仍处于正常范围内。During the service of fuel rods in the reactor,the primary break will lead to the secondary hydriding failure of cladding,which is an important factor leading to the serious damage of fuel rods.Post-irradiation examination on the failure fuel rods was carried out at Fuel and Material Examination Facility in China Institute of Atomic Energy.The secondary hydriding behavior of fuel rods was observed and analyzed by the method of metallography in hot cell.The results show that the hydride swelling phenomenon is significant at the position of secondary hydriding failure,the hydride diffuses from the inner side to the outer side of the cladding in stages and forms a“sun-burst”phenomenon eventually.The temperature of the pellet increases significantly at the position of secondary hydriding failure,which causes pore migration,grain growth of the pellet and columnar crystal growth.Comparing with the intact rods,the thickness of the water side oxide film at the position of secondary hydriding failure increases,but the values is still within the criteria.

关 键 词：辐照后检验 破损燃料棒 锆合金 二次氢化 氢化物 二氧化铀 压水堆核电站 

分 类 号：TL349[核科学技术—核技术及应用]