针对非均匀性明显的某放射性废物处置场候选场址,应用分形理论方法,在介质水力性质参数与介质结构分维之间建立函数关系式来描述场址介质的非均匀性,并选择放射性废物中的代表性核素^3H和^90Sr应用不同方法对核素迁移进行预测比较.结果表明,采用分形理论方法预测的核素迁移浓度比参数直接回归法更接近实际情况:在应用不同参数确定方法预测核素迁移浓度时,分配系数的取值对预测结果影响较大.
Homogenous media assumption and average parameter model are common methodologies to predict the migration of nuclide. However, these kinds of methods will bring obvious deviation to that of typical heterogeneous media. Heterogeneity was solved by constructing a function between hydrogeologic parameters and fractal dimensions of the porous media in the projected radioactive waste disposal site. The hydrogeologic papameters identified in this way were further applied to predict the migration of the representative nuclides ^3H and ^90Sr in the radioactive waste disposal site. The prediction of nuclide migration based on fractal method was more accurate than that based on regression method. The predicted concentration was also a function of distribution coefficient of the nuclides.