基于NECP-MCX的组件均匀化计算及其在HPR1000中的应用  

Assembly-Homogenized Calculation based on NECP-MCX and Its Application in HPR1000

作　　者：秦帅 李云召[1] 贺清明[1] 白家赫 董文昌 曹良志[1] 吴宏春[1] Qin Shuai;Li Yunzhao;He Qingming;Bai Jiahe;Dong Wenchang;Cao Liangzhi;Wu Hongchun(School of Nuclear Science and Technology,Xi’an Jiaotong University,Xi’an,710049,China)

机构地区：[1]西安交通大学核科学与技术学院,西安710049

出　　处：《核动力工程》2023年第3期21-27,共7页Nuclear Power Engineering

基　　金：国家自然科学基金(U2067209);中核集团领创科研项目基金;中核集团青年英才项目;国家重点研发计划(2017YFE030203-05)。

摘　　要：基于蒙特卡罗的组件计算程序可以处理复杂几何问题,同时不需要确定论组件计算程序中的共振自屏计算,但是蒙特卡罗组件计算程序在扩散系数和不连续因子的产生上存在一定困难。因此,基于连续能量蒙特卡罗粒子输运计算程序NECP-MCX,开发了组件均匀化少群常数产生功能,使用严格考虑中子各向异性的累积徙动面积法产生扩散系数,利用基模修正考虑中子泄漏对中子能谱的影响,提出网格面计数方法计算修正的组件不连续因子。根据VERA二维组件问题对网格面计数方法进行了验证,并将NECP-MCX用于我国自主化核电“华龙一号”零功率启动物理试验的模拟计算。结果表明,与设计值对比,临界硼浓度、等温温度系数、控制棒积分价值的计算偏差均符合工业限值要求。该程序可以产生可靠的组件均匀化少群常数,计算精度符合工程计算的要求,为该程序在新型反应堆中的进一步应用打下了坚实基础。The assembly code based on the Monte Carlo method can handle problems with complicated geometry and avoid the resonance self-shielding calculation in the deterministic assembly code.However,the Monte Carlo assembly code has certain difficulties when generating diffusion coefficient and assembly discontinuous factors.Therefore,the capability for the generation of assembly-homogenized few-group constants is developed based on the continuous-energy Monte Carlo particle transport code NECP-MCX.The cumulative migration area method,which treats the anisotropy of neutron explicitly,is adopted to generate the diffusion coefficient;the fundamental mode approximation is used to consider the effect of neutron leakage on the neutron spectrum;the approach named as the mesh-surface tally is proposed to calculate the corrected assembly discontinuous factors.The mesh-surface tally approach is verified through VERA 2D assembly problems and the NECP-MCX is adopted to simulate the physics start-up test of the homedeveloped HPR1000 reactor.The results show that the biases of critical boron concentrations,the isothermal temperature coefficients,and the control rod bank worth values satisfy the limited value when compared to the design report.The NECP-MCX has the ability to generate reliable assemblyhomogenized few-group constants of which accuracy satisfies the requirement of engineering calculation,laying a solid foundation for the further application of NECP-MCX in next-generation reactors.

关 键 词：少群常数 NECP-MCX 蒙特卡罗 华龙一号(HPR1000) 

分 类 号：TL329[核科学技术—核技术及应用]