一种通过边界注量率耦合的MOC和S_(N)二维耦合中子输运方法  

A Two-dimensional Coupled Neutron Transport Method for MOC and S_(N) via Boundary Fluence Rate Coupling

作　　者：张思凡 袁媛 刘宙宇[1] 周欣宇 曹良志[1] Zhang Sifan;Yuan Yuan;Liu Zhouyu;Zhou Xinyu;Cao Liangzhi(School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an,710049,China;China Nuclear Power Engineering Co.,Ltd.,Beijing,100840,China)

机构地区：[1]西安交通大学核科学与技术学院,西安710049 [2]中国核电工程有限公司,北京100840

出　　处：《核动力工程》2022年第2期9-16,共8页Nuclear Power Engineering

基　　金：国家重点研发计划(2017YFE0302200);国家自然科学基金(11735011)。

摘　　要：当使用特征线方法(MOC)计算堆外探测器或某些特殊的重水慢化轻水冷却的实验堆时,因其活性区外部结构材料或慢化剂区域过大,密集的特征线会导致计算资源大量浪费。为解决这一问题,提出了一种新的基于MOC和离散纵标(S_(N))节块法的耦合输运方法,并在数值反应堆物理计算程序NECP-X中实现。该方法将计算区域划分为MOC域(包括活性区等复杂结构区域)和S_(N)域(包括慢化剂和反射层等简单结构区域),然后对2个区域的网格进行混合扫描,通过区域交界面的角注量率进行耦合;同时提出了一些可行的方法来减缓耦合边界角注量率带来的误差。最后通过二维C5G7基准题和全堆芯问题的测试来验证耦合方法的计算效果,数值结果表明该方法具有良好的计算效率和精度。When the method of characteristics(MOC)is used to calculate the out-of-pile detector or some special heavy water moderated light water cooled experimental reactor,the dense characteristics will lead to a large waste of computing resources because the external structural material or moderator area of its active region is too large.To solve this problem,a new coupled transport method based on MOC and discrete ordinate(S_(N))nodal method is proposed and implemented in the numerical reactor physics calculation program NECP-X.In this method,the calculation region is divided into MOC domain(including complex structure regions such as active region)and S_(N) domain(including simple structure regions such as moderator and reflector),and then the grids of the two regions are subject to hybrid sweeping and coupled through the angular fluence rate of the region interface;At the same time,some feasible methods are proposed to reduce the error caused by the fluence rate of the coupling boundary angle.Finally,the calculation effect of the coupling method is verified by the test of two-dimensional C5G7 benchmark task and whole core problem.The numerical results show that the coupling method achieves superior efficiency and accuracy.

关 键 词：特征线方法(MOC) 离散纵标(S_(N))节块法 混合扫描 NECP-X 

分 类 号：TL323[核科学技术—核技术及应用]