Diffusion dialysis aided electrodialysis process for concentration of radionuclides in acid medium

A study on the separation of the long-lived heat generating fission products 137Cs and 90Sr from acidic solutions has been carried out using a specially fabricated electrodialytic cell equipped with a pair of cation and anion exchange membranes forming a catholyte and anolyte, respectively, and a radioactive feed chamber. The studies were done with feed solutions containing different concentrations of Na+, Cs+ and Sr2+ individually and with a mixture of these cations in 0.3M HNO3. In all the cases, the transfer of Cs and Sr was found to be greater than 90%. To facilitate the separation of the above radionuclides from higher acidity (∼ 3.0M HNO3), diffusion dialysis was taken as a possible pretreatment step using a two compartment diffusion cell with an anion exchange membrane in between. All the experiments were done under non-stirring mode. (author)