Radiation resistance and saturated adsorption capacity of a superabsorbent polymer and anion-supporting hydrogel for the safe storage of treated water

Abstract

AbstractTreated tritium-containing water is stored in tanks at the Fukushima Daiichi Nuclear Power Plant until ocean discharge is completed; however, the risk of leakage and contamination remains. We propose the combination of a superabsorbent polymer and an anion-supporting hydrogel for the safe and long-term storage of this water. The external radiation resistance of these materials in the presence of water was investigated, and their water absorption and Cs+ and I retention capacities following irradiation to a cumulative absorbed dose of up to 40 Gy were determined. The superabsorbent polymer demonstrated good water retention and Cs+ adsorption capability. The saturated I adsorption capacity of the hydrogel was 575 ± 28 mg/g, and maintained up to an absorbed dose of 100 Gy. The proposed method can be implemented until the planned completion of water processing even if the storage location has a dose rate of 100 µGy/h.