Best-Estimation Plus Uncertainty (BEPU) analysis method can provide more information to improve the reliability of calculation results than the safety analysis with conservative assumption. And the statistical sampling-based uncertainty and sensitivity analysis methods are widely used in practical applications of the multiphysics, multiscale coupling nuclear reactor system. In this paper, a novel and efficient sampling method for inputs with normal and uniform distributions is introduced and a systematic theory for uncertainty and sensitivity analysis is established based on the classical statistical theory. Then the Code of Uncertainty and Sensitivity Analysis (CUSA) is updated based on these new strategies. For applications, the explicit and implicit effects for resonance and nonresonance isotopes are studied in depth, and a simple UO₂ pin cell is considered to examine the performance of CUSA and the total uncertainty and sensitivity analysis abilities. The numerical results indicate that the implicit sensitivity analysis model and the uncertainty quantification functions developed in CUSA are correct and can be used for sensitivity and uncertainty analysis in nuclear reactor calculations. Even more important, the LHS-SVDC is recommended to propagate the uncertainties in multigroup cross sections.

中文翻译：

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不确定度和敏感性分析准则（CUSA）的新策略及其在核反应堆计算中的应用

与保守估计相比，最佳估计加不确定度（BEPU）分析方法可以提供更多信息来提高计算结果的可靠性。基于统计采样的不确定度和灵敏度分析方法被广泛应用于多物理场，多尺度耦合核反应堆系统的实际应用中。本文介绍了一种新颖，有效的正态分布和均值分布输入采样方法，并基于经典统计理论建立了不确定性和灵敏度分析的系统理论。然后，基于这些新策略更新了不确定性和敏感性分析代码（CUSA）。对于应用，深入研究了共振和非共振同位素的显性和隐性效应，并研究了简单的UO考虑使用₂针电池来检查CUSA的性能以及总不确定度和灵敏度分析能力。数值结果表明，CUSA建立的隐式灵敏度分析模型和不确定性量化函数是正确的，可用于核反应堆计算中的灵敏度和不确定性分析。更重要的是，建议使用LHS-SVDC来传播多组截面中的不确定性。