燃料包壳腐蚀结垢机理及影响因素研究

Study on the Corrosion-Scaling Mechanism of Fuel Cladding and Influencing Factors

燃料包壳结垢引起的腐蚀异常是导致燃料棒失效的重要原因之一。由于一回路水化学、反应堆运行模式、系统设备的更换、燃料设计和堆芯燃料管理等多种因素的综合作用,一回路系统释放的腐蚀产物(又称为污垢)会沉积在堆芯上部的燃料棒包壳表面,大量腐蚀产物的沉积会导致燃料棒包壳表面局部温度升高,引起包壳腐蚀加速,严重情况下会导致燃料包壳失效。本文对燃料包壳的腐蚀结垢机理进行研究,同时对其影响因素进行确定,为燃料包壳腐蚀结垢模型的建立奠定基础,对燃料棒综合性能分析中腐蚀模型的优化具有重要意义。

Fuel corrosion anomaly caused by CILC(crud induced localized corrosion)is one of the important reasons for fuel failure.Under the combination of primary water chemistry,reactor operating mode,exchange of system equipment,fuel design and fuel management,corrosion products(also called“crud”)released from primary system can be deposited on the fuel cladding surface in the upper core,and lots of the deposited corrosion products can cause the localized temperature arising on the fuel cladding surface,and then can induce cladding corrosion accelerated,and can even lead to the fuel failure.In this paper,the corrosion-scaling mechanism of fuel cladding is studied and the influencing factors are determined,which lays a foundation for the establishment of corrosion-scaling model,and is of great significance to the optimization of corrosion model in the comprehensive performance analysis of fuel rods.