98-35E

The object "Shelter" at Chernobyl nuclear power plant contains a lot of radioactive materials. Aqueous medium increases their mobility so that dangerous elements are persistently penetrating into environment with ground water. This situation and recent measurements are discussed. The egress is supposed to have a diffusion nature. A model for the diffusion treatment of active elements migration with ground and subterranean water is proposed. The diffusion coefficients are derived from nonequilibrium statistical mechanics. They are expressed through singlet and pair equilibrium distribution functions to be evaluated for radioactive particles near a dielectric wall modeling ground at various concentrations.