ABSTRACT An uncertainty analysis of the OECD/NEA LWR UAM benchmark Phase I was performed by CASMO5 using JENDL-4.0 and ENDF/B-VII.1, and the individual influence of nuclide/reaction covariance data was estimated to preliminary discuss the important covariance data on the uncertainties of lattice physics parameters used in core calculations. In the boiling water reactor and pressurized water reactor UO2 fuel assembly problems, the random sampling was used to estimate the uncertainties of lattice physics parameters. The difference in the covariance data between JENDL-4.0 and ENDF/B-VII.1 was discussed by comparing the influence of nuclide/reaction covariance data. In terms of the k-infinity uncertainty, it was confirmed that the large discrepancy between the two nuclear data libraries was caused by the covariance data of 235U [ - ] (i.e. the magnitude of the 235U nubar (an average number of neutrons per fission) uncertainty), which was one of the dominant covariance data. In addition, even though the covariance data of 238U [elastic-(n,n’)], 90Zr [elastic-elastic], and 157Gd [(n,γ)-(n,γ)] had the large influence on the assembly-homogenized 2-group macroscopic cross section and pin power distribution, those data were lack in JENDL-4.0. Thus, it is important to take into account the discrepancy and lack of such covariance data in future uncertainty analyses.

中文翻译：

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使用 CASMO5 和 JENDL-4.0 和 ENDF/B-VII.1 对 OECD/NEA LWR UAM 基准阶段 I 的不确定性分析

摘要 CASMO5使用JENDL-4.0和ENDF/B-VII.1对OECD/NEA LWR UAM基准阶段I进行不确定性分析，估计核素/反应协方差数据的个体影响，初步讨论重要的协方差数据关于用于岩心计算的晶格物理参数的不确定性。在沸水堆和压水堆UO2燃料组件问题中，随机抽样被用来估计晶格物理参数的不确定性。通过比较核素/反应协方差数据的影响，讨论了 JENDL-4.0 和 ENDF/B-VII.1 之间协方差数据的差异。在k-infinity的不确定性方面，证实了两个核数据库之间的巨大差异是由235U [ - ] 的协方差数据引起的（即 235U nubar 的大小（每次裂变的平均中子数）不确定性），这是主要的协方差数据之一。此外，即使 238U [elastic-(n,n')]、90Zr [elastic-elastic] 和 157Gd [(n,γ)-(n,γ)] 的协方差数据对装配有很大影响- 均质化的 2 组宏观横截面和引脚功率分布，这些数据在 JENDL-4.0 中是缺乏的。因此，在未来的不确定性分析中考虑这种协方差数据的差异和缺乏是很重要的。γ)]对组装均匀化的2组宏观截面和引脚功率分布有很大影响，这些数据在JENDL-4.0中是缺乏的。因此，在未来的不确定性分析中考虑这种协方差数据的差异和缺乏是很重要的。γ)]对组装均匀化的2组宏观截面和引脚功率分布有很大影响，这些数据在JENDL-4.0中是缺乏的。因此，在未来的不确定性分析中考虑这种协方差数据的差异和缺乏是很重要的。