基于MOSASAUR程序的中子-光子输运堆芯释热率计算方法研究

Research on the Neutron-photon Transport and Heat Calculation Method Based on MOSASAUR Code

为了准确计算快堆堆芯中所有裂变材料与非裂变材料释热,并精细考虑中子、光子、电子在堆芯中的能量沉积,以提高快堆堆芯释热率计算精度。本文基于确定论两步法研究并实现了中子-光子输运堆芯释热率计算方法,通过求解裂变源中子输运方程和固定源光子输运方程得到中子和光子注量率,基于比释动能(KERMA)因子方法计算瞬发中子和瞬发光子释热率,利用比例因子方法计算缓发光子产生矩阵,在MOSASAUR程序内通过内耦合方式实现了快堆中子-光子输运和堆芯释热率计算。计算铅铋快堆RBEC-M基准题的功率分布并与蒙特卡罗程序计算结果进行对比,燃料组件总功率相对偏差在±4%以内,非燃料组件总功率相对偏差在±10%以内,所有组件光子功率相对偏差在±10%以内。因此,本文研究的中子-光子输运堆芯释热率计算方法对快堆堆芯释热计算具有较高精度。

To accurately calculate the heat released by all fissile and non-fissile materials in the fast reactor core,with a meticulous consideration of energy deposition by neutrons,photons,and electrons within the core,so as to enhance the precision of heat generation calculations,this paper,based on the deterministic two-step method,explores and implements a neutron-photon coupled transport calculation method.By solving the fission-source neutron transport equation and the fixedsource photon transport equation,the neutron and photon flux are obtained.Prompt neutron and prompt photon heat generation rates are calculated using the KERMA factor method.The delayed photon production matrix is computed using the scaling factor method.A self-coupling method in the MOSASAUR code is employed to achieve neutron-photon transport and heat generation calculations within the fast reactor core.The power distribution of the lead-bismuth fast reactor RBEC-M benchmark is compared with the results from Monte Carlo code.The relative deviations of total power are within±4%for fuel assemblies,within±10%for non-fuel assemblies,and within±10%for all assemblies'photon power.Therefore,the neutron-photon transport and heat calculation method studied in this article has a high level of accuracy for the fast reactor cores.