NECP-X程序中基于全局-局部耦合策略的非棒状几何燃料共振计算方法研究

基于NECP-X程序中已经研发的全局-局部耦合共振计算方法，研究了针对非棒状几何燃料的共振计算方法。首先，采用中子流方法计算真实问题的丹可夫修正因子，以处理全局的空间效应；其次，基于丹可夫修正因子等效获得小规模问题周围慢化剂的几何信息；最后，对于小规模问题燃料区的有效自屏截面的计算采用共振伪核素子群方法。将该方法应用于非棒状几何燃料数值计算，结果表明，该方法在处理非棒状几何燃料栅元的共振计算时，与蒙特卡罗结果程序相比，微观吸收截面偏差不超过1.8%，无限介质增殖因数偏差不超过110 pcm（1 pcm=10-5），具有较高的计算精度；在大规模问题的计算中，基于板状燃料的JRR-3M实验堆全堆在整个燃耗过程有效增殖因数偏差均在300 pcm左右，组件功率偏差在整个燃耗过程不超过0.62%。因此，本研究提出的共振计算方法具有较高的正确率和精度。 

Resonance Calculation Method for Non-Rod-Type Fuel in NECP-X Based on Global-Local Coupling Method

Based on the global-local coupling resonance calculation method that has been developed in the NECP-X program, this paper studies the resonance calculation method for non-rod-type fuels. Firstly, the Dancoff correction factor of the real problem is calculated by the neutron current method to deal with the global spatial effect. Then, the pitch of the moderator around small-scale problem is obtained based on the equivalent Dancoff correction factor. Finally, for the calculation of the effective self-shielding cross-sections of the small-scale problem, the resonance pseudo-nuclides subgroup method is used. The method is applied to the numerical calculation of non-rod-type fuel. Numerical results show that when compared with the Monte Carlo results, the maximum microscopic absorption cross-section deviation is less than 1.8%, and the kinf deviations do not exceed 110 pcm when the method deals with the resonance of non-rod-type fuel pins. These results show that the method has high calculation accuracy;in the calculation of large-scale problem, the deviation of keff of the JRR-3 M which is based on plate fuels is about 300 pcm during its burnup life, and the maximum assembly power deviation is less than 0.62%. Therefore, the resonance calculation method proposed in this paper has a high accuracy and precision.