Incorporation of Radioactive Spent Ion Exchange Resins in Plastics

Abstract

Experiments were undertaken on the incorporation in plastics—polyethylene in particular—of radioactive spent ion exchange resins produced in nuclear power plants. The resulting polyethylene products burdened with radioactive resin were tested to ascertain the properties considered important for radioactive waste management. The items chosen for testing were mechanical strength, leachability of radionuclide and radiation resistance. Polyethylene products burdened with 50w/o of resin were found to possess an impact strength of 10kg-cm/cm and a compressive strength of 300 kg/cm2, which values do not indicate any appreciable decrease in mechanical strength compared with polyethylene unburdened with resin. The leaching rate of 137Cs from the resin- burdened polyethylene product was very small—only 0.1% leached out in one year. In respect of decomposition by radiation, the amount of gases evolving upon absorbing a dose of 109 rad was 10 ml/g. The effect of radiation on the mechanical strength was also studied. It is concluded from above results that solidification of radioactive spent ion exchange resin by incorporation in plastics is one of the best methods devised so far for treating spent resins.