燃料棒边缘效应下的子群共振计算方法研究

Subgroup Resonance Calculation Method under Rim Effect in Fuel Rod

共振伪核素子群方法可用于处理燃料棒内部空间相关的共振干涉效应,然而该方法只能计算径向均匀核子密度的燃料棒问题,无法处理因边缘效应造成的径向核子密度非均匀分布的问题。针对此问题,基于改进的伪核素理论,提出了一种新的伪核素方法。计算结果表明,该方法解决了原始共振伪核素子群方法无法处理的边缘效应问题,相比于Bondarenko迭代法和干涉因子法,具有更高的精度。

Pseudo-resonant-nuclide subgroup method（PRNSM）is capable to treat spatially self-shielding effect in fuel rod.However,it requires the number densities of resonance nuclides to be constant throughout the whole fuel region,so the spatial distributions of resonance nuclides’ densities caused by rim effect cannot be taken into account.To solve this problem,a new method was proposed on the base of improved pseudo-resonant-isotope-theory.Numerical results show that this method solves the limit of PRNSM on rim effect and has higher accuracy than Bondarenko iteration method and resonance interference factor method.