基于子群方法的双重非均匀性共振计算方法研究

Resonance Treatment for Double Heterogeneity Based on Subgroup Method

摘要: 为计算双重非均匀性条件下的共振截面，提出了耦合SanchezPomraning方法的改进的子群方法(ISSP)。ISSP采用精细化共振能群结构来规避共振干涉处理，通过求解双重非均匀性条件下的子群固定源方程和慢化方程得到颗粒和基体等各材料的有效共振截面，最后进行双重非均匀性条件下的输运计算。数值结果表明，与连续能量蒙特卡罗程序及超细群计算结果相比，ISSP可精确高效地计算双重非均匀性条件下的共振截面。

Abstract: The improved subgroup method coupled with Sanchez-Pomraning method (ISSP) was proposed for the resonance self-shielding calculation of double heterogeneity (DH) problems. ISSP employed a fine-mesh energy structure to avoid the extra resonance interference treatment. The DH subgroup fixed source equations and the neutron slowing-down equations were established to obtain the effective resonance cross-section in particle and matrix. Finally, the transport calculation under DH condition was carried out. By contrast with the continuous-energy Monte Carlo method and the ultra-fine group method, numerical verification results indicate that ISSP could provide resonance cross-section in DH condition accurately and effectively.