Calculations for assessing the dispersion of radioactive substances in ground water and percolation water

For the case of a spot-type, short-term infiltration of radioactive substances into the sub-soil, their dispersion is calculated according to classical dispersion theory, which requires basic data describing the longitudinal and the transversal dispersion. For the case of a large-area, relatively continuous infiltration into the sub-soil throughout the seasonal periods, an exponential model or a dispersion model is used, depending on the hydrogeological conditions. All models are verified in practice and applicable to homogeneous body of rock. In case of large-area anisotropies, the models have to be modified. (orig./PW)