UO_(2)燃料裂变气体渗流模型研究  

Research on Percolation Models of UO_(2) Fission Gas Release

作　　者：李文杰[1] 齐飞鹏 孙丹 辛勇[2] 李权[2] 李垣明[1] Li Wenjie;Qi Feipeng;Sun Dan;Xin Yong;Li Quan;Li Yuanming(Science and Technology on Reactor System Design Technology Laboratory,Nuclear Power Institute of China,Chengdu,610213,China;Nuclear Power Institute of China,Chengdu,610213,China)

机构地区：[1]中国核动力研究设计院核反应堆系统设计技术重点实验室,成都610213 [2]中国核动力研究设计院,成都610213

出　　处：《核动力工程》2022年第3期226-231,共6页Nuclear Power Engineering

基　　金：核反应堆系统设计技术重点实验室开放基金2019年基金(6142A07190101)。

摘　　要：为分析UO_(2)燃料晶界气泡连通导致裂变气体间歇性释放的动力学过程,从而解决目前扩散模型预测的沿芯块径向释放份额与实验测量不符的问题,采用二维渗流模型模拟UO_(2)燃料晶界气泡网络的演化及与燃料棒内自由空间连通的释放过程。研究结果表明,渗流模型预测沿芯块径向的裂变气体释放份额在芯块中间部分出现局部峰值,并随着时间向芯块外侧推进,与辐照试验观察到不同燃耗下径向裂变气体分布现象定性符合。因此,本研究建立的渗流模型能够从机理上解释此前扩散模型未能预测的UO_(2)燃料裂变气体释放份额沿径向非单调分布现象。In order to analyze the dynamic process of intermittent release of fission gas caused by UO_(2) fuel grain boundary bubble connection,so as to solve the problem that the radial release share predicted by the current diffusion model is inconsistent with the experimental measurement,a two-dimensional percolation model is used to simulate the evolution of UO_(2) fuel grain boundary bubble network and the release process connected with the free space in the fuel rod.The results show that the percolation model predicts that the share of fission gas released along the radial direction of the pellet shows a local peak in the middle part of the pellet,and advances to the outside of the pellet with time,which is qualitatively consistent with the radial fission gas distribution phenomenon observed in the irradiation test under different burnups.Therefore,the percolation model established in this study can explain the radial non-monotonic distribution of fission gas release share of UO_(2) fuel that could not be predicted by the previous percolation model from the mechanism.

关 键 词：模拟 核燃料 裂变气体释放 渗流 

分 类 号：TL334[核科学技术—核技术及应用]