破损燃料组件修复后的物理特性分析

破损燃料组件修复后再次入堆使用是必须进行安全评估,以确保核安全。本文以采用AFA3G燃料组件的CPR1000机组为研究对象,对装入反应堆后的正常燃料组件和修复燃料组件的核物理和功率分布进行分析评估。结果表明:燃料组件内更换一根燃料棒对燃料组件反应性的影响很小,该影响可以忽略。更换不锈钢棒的数量越大,燃料组件反应性变化幅度越大。随着燃耗的加深,燃料组件反应性变化幅度也增大。修复的燃料组件虽然在换棒位置局部区域发生功率畸变,相对功率略微的升高,但离换棒位置较远的燃料棒的相对功率没有变化,换棒不会导致组件内功率峰发生象限的偏移。

Analysis of the Physical Characteristics of Damaged Fuel Assemblies after Repair

Damaged fuel assembly which being repaired can be used in reactor only after evaluation and nuclear safety being ensured for the reactor. This report takes CPR1000 unit with AFA3G fuel assembly as the research object,and analyzes the physical characteristics and power distribution of normal fuel assembly and damaged fuel assembly after repair. It can be found that the effect on fuel assembly reactivity is very small for the fuel assembly replaced with a stainless steel rod,and the effect can be ignored. The more stainless steel bars been inserted in the fuel assembly,the greater magnitude of the fuel assembly reactivity changes. The fuel assembly reactivity variation range also increases along with burnup increase. The relative power of fuel rods which near stainless steel rod increase slightly. The relative power of the fuel rods farther away from the stainless steel rod does not change. The power peak still remained in the same quadrant.