Аннотация:Processes of pore diffusion and sorption of RW elements in compacted (ρт = 1.74-1.86 g/cm3) samples of clay barrier materials saturated with model underground water were studied in the experimental cell by the through diffusion method at room temperature. Numerical values of effective (De) and apparent (Da) diffusion coefficients and sorption capacity coefficients () of clay materials were defined for elements forming neutral (НТО0) and charged (Cs+, Sr2+, UO22+, Br-, SeO32-) particles of different size with different sorption capacity in aqueous solution. It was found that by the value of diffusion-sorption characteristics in the pore solution of barrier materials, the studied elements form rows: De – Sr>HTO>Br>Cs>U>Se, Da – Br=Sr> U>Cs=Se, – Sr>Cs>U=Se=Br.