基于DRAGON程序的二维/一维耦合堆芯输运计算程序开发

Development of Coupled 2D/1D Whole Core Transport Calculation Code Based on DRAGON

DRAGON程序能够进行三维特征线法(MOC)计算,但需大量的计算时间与内存,虽在其中引入大量近似并应用多种加速算法,仍无法满足工程应用的需求。基于DRAGON程序中现有的二维MOC计算模块,开发二维MOC与一维节块展开法(NEM)耦合的堆芯输运计算程序DRAGON_HEU,在三维粗网有限差分(CMFD)加速算法的全局框架下通过轴向和径向泄漏项将二维全堆非均匀栅元MOC计算与轴向均匀栅元扩散计算耦合,实现三维堆芯Pin-by-Pin计算。运用C5G7-3D三维扩展基准题验证DRAGON_HEU,计算结果表明:DRAGON_HEU能够节约大量计算时间且具有很高的计算精度。

DRAGON code can conduct 3D method of characteristics （MOC） heterogeneous core calculations by introducing a lot of approximations and multiple acceleration methods, but the computing memory and time are still unaffordable for present engineering application. The transport calculation code DRAGON_HEU which is developed based on the 2D MOC calculation module of DRAGON code employs a coupled planar MOC solution and axial diffusion solution scheme, 2D full core heterogeneous pin MOC calculation and 1D homogeneous axial pin diffusion calculation are coupled through radial and axial leakage under the 3D coarse mesh finite difference （CMFD） global framework, in such way the whole core Pin-by-Pin calculation is achieved. DRAGON HEU code is testified with the C5G7 3D extension benchmark. Numerical results demonstrate that DRAGON_HEU code can achieve good accuracy while saving a large amount of time.