不同燃耗计算模型对商用压水堆乏燃料组件核素成分的影响分析

燃耗计算精度对提高乏燃料贮存效率有着重要影响，在应用燃耗信用制时，燃耗计算得到的核素成分偏差决定了乏燃料贮存的临界安全裕量。不同燃耗计算模型所得到的核素成分偏差各不相同，为提高燃耗计算精度，提出了一种装载不同燃料富集度的多组件燃耗计算模型，并使用不同燃耗计算模型分别对TMI-1反应堆NJ07OG组件中的6个样本进行了计算、对比和分析。结果表明，相比其他模型，考虑不同燃料富集度的多组件模型得到的²³⁵U、²³⁸U和²³⁹Pu等核素平均相对偏差更接近于零且6个样本的相对偏差分布更为平均。

Analysis of different burnup calculation models on nuclide components of spent fuel assembly in commercial pressurized water reactor

Burnup credit has an important impact on improving the efficiency of spent fuel storage. In the burnup credit, the burnup calculation model can affect the nuclide composition deviation, and the more accurate the nuclide composition, the lower the critical safety margin for spent fuel storage. To improve the accuracy of the burnup calculation, a multi-assembly burnup calculation model loaded with different fuel enrichment is proposed in this paper. Six samples of TMI-1 reactor NJ07OG assemblies were calculated, compared and analyzed by using different burnup calculation models. The results show that the average relative deviations of 235U, 238U and 239Pu obtained from the multi-assembly burnup model with different fuel enrichment are closer to zero and the relative deviations are more evenly distributed among the six samples than that of other models.