Analysis methodology of nuclear data-related uncertainty for neutronics calculation of complex cores in high-flux research reactors

BackgroundHigh-flux research reactors (HFRRs) involve various sources of uncertainty in neutronics calculations, which directly affect operational safety. With the continuous advancement of computational power, nuclear data uncertainty has emerged as the dominant factor limiting the precision of these calculations.PurposeThis study aims to focus on nuclear data-related uncertainty quantification in neutronics calculations for high-flux research reactor cores.MethodsA comprehensive analysis framework for nuclear data uncertainties in reactor physics calculations of HFRR based on the Full Monte Carlo method was proposed in this study.. Nuclear data-related uncertainties in core physics calculations was systematically evaluated and the impact of different nuclear reaction cross-sections on the keff of a complex core containing diverse types of irradiation channels was quantitatively analyzed.ResultsCalculation results indicate that for a typical HFRR core, the keff uncertainty introduced by nuclear data is approximately 0.5%. Among various reactions, the average number of fission neutrons for ²³⁵U, the ²³⁵U(n,f) reaction, and the ²⁷Al(n,γ) reaction show significant contributions.ConclusionsThe proposed methodological framework in this research provides a theoretical reference for the safe operation and design optimization of high-flux research reactors, and can be extended to the uncertainty analysis of other types of advanced reactors.