基于蒙特卡罗方法的燃耗计算误差研究

基于蒙特卡罗方法进行燃耗计算时，随着燃耗加深，燃耗的计算误差逐渐增大。本文针对蒙特卡罗方法的燃耗计算误差进行研究，并采取修正措施改善燃耗计算的精度。结果表明：采用无偏差最小方差(UMV)修正可改善统计误差的传递效应，采用密度修正可保证蒙特卡罗输运计算的准确性，在此基础上局部优化燃耗截面库，进一步改善了燃耗计算的精度，为其工程应用奠定了基础。

Research on Errors in Monte Carlo Burnup Calculations

Based on the Monte Carlo method for burnup calculations, the errors increase as a function of burnup. The errors of Monte Carlo burnup calculations were studied in this paper, the modification measures were used which could improve the accuracy of burnup calculation. The results show that, the effect of statistical error propagation would be reduced by unbiased minimum variance (UMV) modification, the exactitude of Monte Carlo transport calculation would be ensured by density modification, and the accuracy would be improved further by local optimization of burnup cross-section library, which create conditions for engineering application.