On the diffusion of 90Sr from radioactive wastes bitumenized by the mould method

Monophase diffusion of 90Sr from radioactive wastes into bitumen, at approximately room temperature, is studied using the thin layer method. The diffusion couple absorbent-bitumen is considered as belonging to the semi-infinite type, with constant normalized concentration on the interface. The Matano-Boltzmann method is applied in order to find out the diffusion coefficients and their dependence on the normalized concentration. (orig.)