Abstract: With the view of further studying the migration pattern of radionuclide in porous media,a nonequilibrium sorption-desorption relation is coupled with hydrodynamic dispersion equation, and a nonequilibrium sorption numerical model is establishing.The method for the accluisition of sorption-desorption parameters used in the model is also given.In order to test the correctiveness of the established model and its computer code,the calculation concerned is made using the experimental data of⁸⁵Sr obtained in the field test site, and then compared with the calculated results of nuclide migration equilibrium sorption numerical model.The comparison shows that the established model can describe the actual situation of nuclide migration in a better way.

Key words: Nonequilibrium sorption, Numerical model, Sorption-desorption, Sorption rate coefficient, dew condensation time, dew occurrence frequency, loess hilly region, meteorological factors