快堆堆芯蒙特卡罗计算模型几何优化问题研究

Geometry Optimization of Monte Carlo Modelof Fast Reactor Core

蒙特卡罗建模的几何精细程度问题是计算效率与准确度的平衡问题。反应堆堆芯完全精细化模型的建模难度大,计算效率低,凭经验的均匀化会引入大量计算偏差。本文基于特征值求差法评估了中国实验快堆堆芯具体几何结构的简化对k eff的影响,建立了综合优化模型。计算结果表明,优化模型在保证计算准确度的前提下可大幅提高计算效率。优化模型的具体几何处理方式与详细验证结果为堆芯设计、实验模拟等蒙特卡罗计算量较大的工作提供了借鉴,为蒙特卡罗程序开发、蒙特卡罗理论研究提供了参考。

In Monte Carlo calculation,the geometrical precision of model is equilibrium between calculation efficiency and accuracy of result.The precise modeling of reactor core largely decreases calculation efficiency,while homogenization by experience brings large deviation to the result.In this paper,the influence of geometry simplification of core structures of China Experimental Fast Reactor on k eff was assessed based on eigenvalue-difference method,and an optimized core model was established.The results indicate that the optimized core model largely improves calculation efficiency with the result remaining almost the same.The detailed geometrical treatment and calculation results provide reference for Monte Carlo model in reactor core design and experiment analysis,and present academic worth to Monte Carlo code development and theoretical research.