高燃耗燃料棒在失水事故工况下的行为研究

Research of Behaviors of High-burnup Fuel Rodsduring Loss of Coolant Accident

自从1974年应急堆芯冷却安全验收准则——ECCS准则发布以来,燃料设计以及核反应堆的运行状态都发生了巨大的变化,包括新的燃料和包壳尺寸、新型的包壳合金材料、更高的燃耗和更长的换料周期。这些变化改变了反应堆内的工作环境,影响将来的反应堆设计。设计的试验表明,失水事故工况下,高燃耗燃料棒在远低于安全准则的规定值下发生破裂,性能分析程序Fraptran-1. 5的模拟结果与试验结果一致。未来需要更多的试验数据,为ECCS安全准则的修订提供参考。

Since the initia lversion of Emergency Core Cooling System(ECCS)was published in 1974,notonly the designation of fuelrods,butalso working conditions of nuclear reactors have been changed,including different sizes of fuel rods and claddings,new developed material of claddings,higher burnup and extended reload cycle,which will influence the design of nuclear reactors in the future.Results of designed tests show that high burnup fuel rod fails before its safety values which are specified by ECCS.Analog results of Fraptran-1.5 are in good accordance with tests results.More data of high-burnup tests are needed to refer in order to revise ECCS.