针对含有随机分布裂变材料颗粒的一维球形二元随机系统,采用统计与确定论方法相结合进行数值求解。通过蒙特卡罗抽样得到随机系统的平均弦长,进而用SN方法数值求解含有特征值的统计输运方程,得到随机系统有效增殖因子的统计平均值。通过构造测试问题,对不同散射比、弦径比及不同数量、尺寸随机裂变燃料球系统的计算结果进行了分析。直接模拟结果与假设随机颗粒均匀布置计算结果的比较表明,该计算方法可对给出的大多数测试问题能得到更为接近的结果。
A statistical transport equation is presented in this paper to obtain the ensemble average keff for the binary stochastic media with random fissile pellets.Combined method of statistics and deterministics is proposed to directly solve the multiplying binary stochastic problem in 1-D spherical geometry.In the com-bined method,Monte Carlo sampling method is employed to determine the mean chord length of the stochas-tic system then deterministic SN diamond difference,source iteration method is used to solve the statistical transport equation with eigenvalue.Test stochastic problems of different scattering ratio,different chord-path ratio and different number of random fissile spheres are constructed and compared with references and uni-formly-distributed approximated cases.Results show that the mean value of keff for the given systems can be predicted accurately by the statistical equation in most given cases.