二次中子源的氦生成速率研究

4He Production Rate in the Secondary Neutron Source

二次中子源在受射线辐照的过程中会产生氦气,工程中需根据包壳的承压能力和氦生成速率计算二次中子源的设计寿命。本文针对二次中子源堆内辐照的氦生成相关过程进行分析,在“华龙一号”全堆芯模型基础上开展研究,以堆芯燃料管理方案相关参数为输入,开展燃耗和粒子输运计算,得到平衡循环中不同燃耗深度下二次中子源的氦生成速率及不同核反应道的贡献比。计算结果表明,二次中子源内生成氦的主要核反应的平均微观反应截面和氦生成速率受燃耗深度的影响并不显著,在二次中子源产生氦的主要核反应中,9Be(n,2n)4He的贡献最大,约占71.7%,其他反应道的贡献分别为9Be(n,α)6He约占12.0%,9Be(γ,n)4He约占4.3%,6Li(n,t)4He约占12.0%。

In this paper,a related process of 4He generation in the secondary neutron source reactor is analyzed.Based on the whole core model of“Hualong-1”,a deplete calculation and a particle transport calculation are carried out with the relevant parameters of the core fuel management scheme as input,and the 4He production rate in the secondary neutron source and the contribution ratio of different nuclear reaction channels under different burnup depths in the equilibrium cycle are obtained.The calculation results show that the average microscopic reaction cross-section and 4He production rate of the main nuclear reaction of 4He production in the secondary neutron source are not significantly affected by the burnup depth.Among the main nuclear reactions of 4He production in the secondary neutron,9Be(n,2n)4He contributes the most,accounting for about 71.7%,and the contributions of other reaction channels are:9Be(n,α)6He accounts for about 12.0%,9Be(γ,n)4He accounts for about 4.3%,6Li(n,t)4He accounts for about 12.0%.