高效偶阶离散纵标法研究及初步验证

采用TAKEDA基准题验证高效偶阶离散纵标法(HEPSN)的临界计算功能，数值结果表明:有效增殖因数和各区域平均中子通量密度值与基准值吻合良好，堆芯区域的平均中子通量密度误差在0.7%以内，其他区域较扩散理论误差显著减小。相较于传统离散纵标法，HEPSN计算效率更高，需要的存储更小；相较于扩散理论，HEPSN的计算精度更高。因而，高效偶阶离散纵标法在大规模输运计算中具有很好的应用前景。

Preliminary verification of the high-efficiency even-parity discrete ordinates method

The accuracy and efficiency of core physics calculation have a great impact on the safety of nuclear reactors. As reactor cores get more and more complex, diffusion theory presents low accuracy. Various transport methods are developed and studied. The even-parity discrete ordinates method(EPSN) needs less storage and less computing time due to a reduction in angular domain of one-half compared to the first-order transport equations. The new high-efficiency even-parity discrete ordinates(HEPSN) method is proposed based on optimizing the EPSN method. It is worth noting that HEPSN method only solves one-eighth of the angular domain. HEPSN method appears to have no negative flux, be easy to obtain consistent diffusion synthetic acceleration and have uncoupled reflective boundary conditions. The accuracy of HEPSN method for critical calculation is verified by TAKEDA benchmarks. The results show that the accuracy of HEPSN method is higher than diffusion theory and the computing time and the computer memory are less than EPSN method. HEPSN method has the potential to be applied to the calculations of large reactor cores.