Models for calculating dose rates of spherical particles as well as in fuel cracks are important for radionuclide source term estimations. Dose rates from UO₂ based fuels were calculated for planar, spherical, and crack geometries. The escape probability for α-particles in spherical UO₂ particles was derived as a continuous equation. The dose rate increased with increasing spherical radius due to the decreasing relative volume of the surrounding water layer. The model produced escape probabilities that were closely predicted by the theoretical derivation. It was shown that the dose rate in water filled fuel cracks with width smaller than the range of an α-particle led to dissolution rates that were lower per unit surface area.

用于计算球形粒子以及燃料裂缝中的剂量率的模型对于放射性核素源项估计很重要。计算了平面、球形和裂纹几何形状的基于UO _{2的燃料的剂量率。球形UO 2}粒子中α粒子的逃逸概率被导出为连续方程。由于周围水层的相对体积减小，剂量率随着球形半径的增加而增加。该模型产生的逃逸概率与理论推导密切相关。结果表明，宽度小于 α 粒子范围的充水燃料裂纹中的剂量率导致每单位表面积的溶解速率较低。