IMF燃耗特性与次锕系核素产量分析

摘要

The adoption of inert matrix fuel (IMF) can effectively reduce the amount of minor actinide (MA) in spent fuel of LWR from the source .In order to study the burn‐up characteristics of IMF ,the two typical IMF schemes of PuO2 + ZrO2 + MgO and PuO2 + ThO2 were selected ,and the IMF reactivity with different amounts of PuO2 was calculated .And the comparison among IMF ,UO2 and MOX was made .The results show that after 36 months operating ,with the PuO2 volume fractions of two types of IM Fs from 2% to 10% ,their kinf values at the end of cycle are all above 1 .But the burn‐up reactivity of PuO2 +ZrO2 + MgO scheme is greater than that of PuO2 + ThO2 .The amount of MA at the end of cycle in PuO2 + ThO2 scheme is obviously smaller than the former .Under the same effective heavy metal weight percentage ,the amounts of MA in MOX and UO2 fuels at the end of cycle are both greater than those of the two types of IM Fs .%在轻水堆中采用惰性基质燃料（IMF）能有效地从源头上降低乏燃料中次锕系核素（MA）的含量。为了研究IMF的燃耗特性，选取两种典型IMF方案PuO2＋ZrO2＋MgO和PuO2＋ ThO2，开展不同PuO2含量下IMF燃耗反应性计算，并与 UO2燃料以及MOX燃料进行比较分析。结果表明：在总燃耗时间为1095 d情况下，两种IM F方案中PuO2体积分数为2％～10％时，其寿期末 kinf均大于1，但PuO2＋ZrO2＋MgO方案的燃耗反应性波动大于 PuO2＋ThO2方案，PuO2＋ ThO2方案燃料寿期末MA的含量明显小于前者；在同一等效重金属质量分数下，MOX、UO2燃料寿期末MA的含量均大于两种IMF。