摘要
氟盐冷却高温堆(FHR)作为第4代核能系统,对安全性和经济性更加注重。FHR全空间中子通量密度的精细分布数据对于材料构件的辐照损伤计算、放射性源项分析以及辐射屏蔽设计等均有重要意义。针对这一需求,本文采用离散纵标(SN)方法为蒙特卡罗(MC)方法偏倚计算提供所需的源偏倚和权窗参数,使蒙特卡罗粒子均匀地分布于整个计算模型空间,从而有效降低中子通量密度分布计算的统计误差。在该方法的基础上,编写了耦合程序SN2MCNP,并使用该程序对FHR全空间的中子通量密度分布进行了精细计算。经对比验证,在同样的计算时间和统计方法的要求下,单独使用MCNP计算的结果中,只有30.1%的相对误差达到要求(<10%),而使用SN2MCNP的计算结果中则有99.6%的相对误差达到要求(<10%)。
Fluoride-salt-cooled high-temperature reactor（FHR）as a Gen Ⅳ nuclear energy system has drawn more attention to the safety and economy.The fine neutron flux density distribution of the full-scale FHR is very important to the radiation damage calculation of the material components,the radioactive source term analysis and the radiation shielding design.To solve this problem,the discrete ordinate（SN）method was used to provide the source biasing and weight window parameters for the Monte Carlo（MC）method,making the Monte Carlo particles evenly distributed in the whole model space.It could effectively reduce the statistical error of neutron flux density distribution calculation.Based on this method,the coupling code SN2MCNP was writtenand the neutron flux density distribution of FHR space was finely calculated.After comparison and verification,only 30.1% of the results calculated by analog MCNP has relative uncertainties below the required value（〈10%）,while 99.6% of the results by SN2MCNP has relative uncertainties below the required value（〈10%）adopting the same calculation time and statistical method.
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2017年第10期1749-1755,共7页
Atomic Energy Science and Technology
基金
中国科学院战略性先导科技专项资助(XDA02010200)
