UMo/Al弥散燃料板内裂变气体肿胀的静压效应研究

将核燃料的裂变气体肿胀与静水压力计算相耦合,并考虑重要的辐照蠕变,编制了定义其复杂力学本构关系的子程序。将定义各部分材料热-力学本构关系的用户子程序引入ABAQUS软件,获得了燃料板细观尺度下辐照-热-力耦合行为的计算模拟方法,并计算分析了核燃料裂变气体肿胀的静压效应。与不考虑裂变气体肿胀静压相关性的计算结果对比发现,在裂变气体肿胀计算中引入静压的影响,将使得核燃料颗粒内的辐照肿胀应变显著减小,引起板内最高温度降低,并减弱燃料颗粒和基体间的力学相互作用,减小燃料颗粒内的等效蠕变应变,致使基体内最大Mises应力和第一主应力减小。

Hydrostatic Pressure Effect of Fission Gas Swelling in UMo/Al Dispersion Fuel Plate

The calculations of fission gas swelling and hydrostatic pressure in the nuclear fuel were coupled with each other .With the important irradiation creep also considered , the user subroutine was programmed to define its complex mechanical constitutive rela-tion .With the user subroutines of defining all the materials introduced into ABAQUS , the computational method was developed for simulating the meso-scale irradiation-induced thermo-mechanical coupling behavior in a UMo/Al dispersion fuel plate ,and the hydrostatic pressure effect of the fission gas swelling was analyzed .Comparing the calculated results without considering the hydrostatic pressure effect ,the results with the hydrostatic pressure effect show that the irradiation swelling strain in the fuel parti-cles reduces remarkably ,the highest temperature decreases ,the mechanical interaction between the fuel particles and the matrix is weakened ,and the equivalent creep strains in the fuel particles decrease together with the decrease of the maximum Mises stress and the first principal stress in the matrix .