AP1000燃料组件锆屑产生原因及处理措施探讨

The Discussion of AP1000 Fuel Assembly Zirconium Dust Causes And Treatment Measures

根据AP1000燃料组件结构特点,分析认为燃料组件中锆屑(锆细丝及锆屑积瘤)产生的原因是燃料棒在拉棒过程中,燃料棒与格架中的格架弹簧、刚凸相互挤压刮擦燃料棒产生的。锆细丝或锆屑积瘤如果在燃料组件入堆前无法清除干净,这些锆细丝或锆屑积瘤存留在燃料组件上,燃料组件在堆内运行过程中,由于冷却剂的高速横流使燃料棒过分振动可能造成锆屑磨蚀燃料棒,导致燃料棒破损。针对燃料棒拉棒产生的锆屑,调研了国内外减少拉棒过程中锆屑的产生和处理措施,提出了解决方案建议。

According to the structural characteristics of AP1000 fuel assembly, it is believed that the reason for the formation of zirconium lump or zirconium dust on the fuel assembly is that the rods, grid spring and arch squeeze each other during the pull-rod process. If the zirconium lump or zirconium dust is not well cleaned, they will persist on the fuel assembly, and then during the operation, the zirconium dust will erode the fuel rods because of the excessive vibration caused by the high cross velocity coolant flow. Finally, the rods could be damaged. This paper studies the causes and treatment of zirconium dust at home and abroad and put forward solutions and suggestions to this problem.