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采用广义微扰理论,研究核数据不确定性对先进压水堆AP1000燃料组件宏观截面参数计算不确定性的贡献与影响机理。通过比较、分析不同因素对组件参数计算不确定性的贡献,给出组件宏观截面参数相关系数矩阵;采用敏感性分析方法及分步比较的思路研究在不同堆芯运行状态下核数据对AP1000燃料组件宏观参数计算不确定性贡献的机理。研究结果表明:核数据自身不确定性通过组件输运计算最终传递给宏观截面参数的不确定性是基本恒定的。其中,~(235)U平均裂变中子数反应、~(238)U辐射俘获反应、~(238)U共振非弹性散射反应及~1H共振弹性散射反应对组件宏观截面参数计算不确定性贡献尤为突出。同时,温度升高导致组件kinf及宏观截面参数计算不确定性增加;燃料富集度降低及可燃毒物的存在均使组件kinf计算不确定性增加;组件快群截面计算不确定性远大于热群截面计算不确定性。其中~(238)U辐射俘获反应、共振非弹性散射反应等截面信息应重点关注并且需要进一步评价和改进。
Using generalized perturbation theory, the contribution and influence mechanism of uncertainty of nuclear data to the calculation uncertainty of macroscopic section parameters of AP1000 fuel assemblies are studied. By comparing and analyzing the contribution of different factors to the calculation uncertainty of component parameters, the correlation coefficient matrix of the macro-section parameters of the components is given. Using the sensitivity analysis method and step-by-step comparison, the nuclear data of AP1000 fuel Component Macroscopic Parameters Mechanisms for Calculating Uncertainty Contributions. The results show that the uncertainty of the nuclear data itself is almost constant through the component transport calculation and the uncertainty finally delivered to the macro-section parameters. Among them, U ~ (235) U average fission neutron number reaction, ~ (238) U radiation trapping reaction, ~ (238) U resonance inelastic scattering reaction and ~ 1H resonance elastic scattering reaction Particularly prominent. At the same time, the uncertainty of kinf and macroscopic cross-section parameters increase due to the increase of temperature. The uncertainty of kinf calculation increases with the decrease of fuel enrichment and the presence of flammable toxins. The computational uncertainty of fast cross-section Sectional Calculation Uncertainty. Among them, the cross-section information of ~ (238) U radiation trapping reaction and resonance inelastic scattering reaction should be focused on and need further evaluation and improvement.