Effects of Gamma Ray Irradiation on Physicochemical Characteristics and Leaching Behaviors of Spent Radioactive Anion Exchange Resin

Gamma ray irradiation of spent anion exchange resins resulted in significant physicochemical changes. The poly(styrene-divinylbenzene) (PS-DVB) backbone underwent oxidation, leading to the formation of various oxygen bonds. Damage to the functional group was confirmed by the decomposition and oxidation of the quaternary ammonium group. Oxygen in the air was grafted on PS-DVB backbone at 300 kGy. Both grafting and crosslinking occurred simultaneously at 500 kGy but more active crosslinking reactions. In contrast, at 700 kGy, degradation became predominant over grafting and crosslinking. Thermal analysis showed elevated decomposition temperature and increased residual products, indicating highly crosslinking reactions with escalating radiation dose. The substantial release of cobalt ions and organic substances is observed in the irradiated anion exchange resins. The disposal of spent resins in a radioactive waste facility carries a substantial risk of leaching complexing agents and complexed radioactive isotopes, underscoring the importance of radioactive waste management to minimize environmental hazards. The insights gained from this study are crucial for informing the development of effective risk mitigation strategies and ensuring the safe, long-term containment of radioactive materials in disposal sites.