基于蒙特卡罗程序的热管微堆少群截面制作方法研究

Research on the Few Group Cross-section Production Method for Heat Pipe Micro Reactors Based on Monte Carlo Code

为了提高热管微堆物理计算效率,基于栅元均匀化-堆芯输运计算两步法,从各向异性散射、燃料均匀化模型、泄漏修正、能群结构等方面,开展了基于蒙特卡罗程序的热管微堆输运计算所需少群截面制作方法研究。数值结果表明:采用输运修正、泄漏修正等方法,并且外围燃料采用专门的“燃料-反射层”均匀化模型,两步法计算得到的有效增殖因子(k_(eff))偏差小于100pcm(1pcm=10^(−5)),功率分布偏差小于3%,控制鼓总价值偏差小于5%,且堆芯输运计算代价比蒙特卡罗一步法全堆计算小2个量级。因此,本文研究的栅元均匀化-堆芯输运两步法满足工程设计的精度要求,同时大幅提高了热管微堆物理计算效率。

In order to improve the efficiency of the physical calculations of Heat Pipe Micro Reactors,based on the two-step method of cell homogenization-core transport calculation,this paper studies the few group cross-section production method for Heat Pipe Reactor core transport calculation by using the Monte Carlo(MC)code from the aspects of anisotropic scattering,fuel homogenization model,leakage correction and energy group structure.The numerical results show that using transport correction,leakage correction and other methods,and using a specialized"fuelreflector"homogenization model for the peripheral fuel,the k_(eff)deviation obtained by the two-step core calculation is less than 100pcm(1pcm=10^(−5)),the power distribution deviation is less than 3%,and the the control drum total worth deviation is less than 5%.Moreover,the core transport calculation cost is two orders of magnitude smaller than that of the Monte Carlo one-step full core calculation.Therefore,the two-step method of cell homogenization-core transport studied in this paper meets the accuracy requirements of engineering design and can greatly improve the efficiency of physical calculations of Heat Pipe Micro Reactors.