The results of effective irradiation swelling in a wide range of burnup levels are numerically obtained for an inert matrix fuel, which are verified with DART model. The fission gas swelling of fuel particles is calculated with a mechanistic model, which depends on the external hydrostatic pressure. Additionally, irradiation and thermal creep effects are included in the inert matrix. The effects of matrix creep strains, external hydrostatic pressure and temperature on the effective irradiation swelling are investigated. The research results indicate that (1) the above effects are coupled with each other; (2) the matrix creep effects at high temperatures should be involved; and (3) ranged from 0 to 300 MPa, a remarkable dependence of external hydrostatic pressure can be found. Furthermore, an explicit multi-variable mathematic model is established for the effective irradiation swelling, as a function of particle volume fraction, temperature, external hydrostatic pressure and fuel particle fission density, which can well reproduce the finite element results. The mathematic model for the current volume fraction of fuel particles can help establish other effective performance models.

惰性基体燃料在各种燃耗水平下的有效辐照膨胀结果通过数值计算得到，并通过 DART 模型进行了验证。燃料颗粒的裂变气体膨胀是用机械模型计算的，该模型取决于外部静水压力。此外，惰性基质中还包括辐照和热蠕变效应。研究了基体蠕变应变、外部静水压力和温度对有效辐照膨胀的影响。研究结果表明：（1）上述效应相互耦合；(2) 应涉及高温下的基体蠕变效应；(3) 在 0 到 300 MPa 的范围内，可以发现外部静水压力的显着依赖性。此外，建立了有效辐照膨胀的显式多变量数学模型，作为粒子体积分数、温度、外部静水压力和燃料粒子裂变密度的函数，可以很好地再现有限元结果。当前燃料颗粒体积分数的数学模型可以帮助建立其他有效的性能模型。