摘要
COSINE软件包组件程序是二维、多群输运计算程序,主要用于压水堆组件和单棒的计算,生成少群均匀化常数和核素的核子密度供堆芯程序使用。组件程序的输运计算模块在完成第一阶段两步均匀化方法开发的基础上,为提高程序的先进性和更好满足未来设计需求,现进行开发第二阶段基于特征线(MOC)方法的一步均匀化技术。在输运计算中直接考虑组件的精细构造,消除了两步均匀化方法中由栅元均匀化引入的近似。本文基于MOC方法的输运模块采用循环特征线方法,在方向求积组中的每一个辐角方向内都有一组平行的特征线扫过整个组件区域,每一种栅元类型对应一种特征线几何处理方式。循环特征线方法可确保在二维几何中栅元间的特征线都是完全相接且栅元边界完全满足反射条件。MOC方法在计算精度上减少了近似,且理论上可处理任意几何,但由于大量的存取数据,导致计算时间相对较长。为此,程序使用粗网有限差分(CMFD)技术对MOC计算进行加速,有效地节省了计算时间。在程序开发过程中,测试与验证是开发过程中的重要部分且严格执行质保体系。通过对C5G7基准题比较,数值验证了输运模块的可行性。
The lattice code in COSINE package is a two-dimensional and multi-group transport code which is mainly used for pressurized water reactor （PWR） assemblies or pin cells analysis. It is used to calculate few group constants and nuclei densities for the core code. As an improvement of the first phase code which using two-step homogenization method, the one-step homogenization technique based on MOC method is under developing to satisfy the design need in future. In the new technique, the fine structure of lattice was directly considered, so it could eliminate the error introduced by two-step homogenization method. In this paper, the cyclic characteristic method was employed to trace the neutron transfer which could make sure the characteristic passes through the geometry of the problem and assigns cell types to each individual cell. The cyclic tracking approach also could ensure perfect reflection in two dimensions problem. The MOC method could reduce the approximate and handle the complex geometry problem theoretically. However, the MOC method had disadvantage of low calculation efficiency for large storage in processing. The coarse mesh finite difference （CMFD） was used to accelerate the MOC method in thks paper. In the development of LATC, the quality assurance （QA） process was implemented strictly to ensure the quality of code. The C5G7 benchmark was used as an example to verify the LATC code. The results show that the transport module in LATC is feasible.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2013年第B12期515-519,共5页
Atomic Energy Science and Technology
基金
国家科技重大专项资助项目(2011ZX06004-024)
北京市科技计划资助项目(Z121100003012008)
