快堆三维六角形节块法输运计算研究

摘要

The 3-D hexagonal nodal transport theory calculation method for fast reactor core was studied. Based on this method, 3-D hexagonal nodal transport code NAS-T was developed. The surface average angular fluxes were approximated by an azimuthally symmetric double Pn-expansion DP1 and DP3, and 1-D discrete ordinates equations were solved on a fine spatial mesh within the node. Considering the characteristics of the nodal method, the response matrix method was used in the iterations. Therefore, the calculation within the node was simplified and time was saved. The code was tested for the keff calculation of CEFR and BN-600. A good agreement with the reference results was achieved.%对快堆堆芯的三维六角形节块输运理论计算方法进行了研究.在NAS程序基础上,使用节块输运理论,开发了三维六角形节块法输运程序NAS-T.表面通量采用双球谐DP1近似或DP3近似展开,在节块内采用—维离散纵坐标(SN)方法求解.并根据节块法的特点,在迭代计算时采用了响应矩阵方法,节块内的通量分布用二阶多项式表示,简化了节块内部计算过程,大幅节省了计算时间.对中国实验快堆和BN-600的keff进行了计算,结果符合良好.