Chee Tien-Shee, Lee Sujeong, Ng Woei Jer, Akmal Muhammad, Ryu Ho Jin
Department of Materials Science and Engineering, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea.
Department of Nuclear and Quantum Engineering, KAIST, Yuseong-gu, Daejeon 34141, Republic of Korea.
ACS Appl Mater Interfaces. 2023 Aug 30;15(34):40438-40450. doi: 10.1021/acsami.3c06761. Epub 2023 Aug 15.
Radioactive waste management is critical for maintaining the sustainability of nuclear fuel cycles. In this study, we propose a novel bismuth-based reduced graphene oxide (Bi-rGO) composite for the immobilization of off-gas radioactive iodine. This material synthesized via a solvothermal route exhibited a low surface area (2.96 m/g) combined with a maximum iodine sorption capacity of 1228 ± 25 mg/g at 200 °C. The iodine sorbent was mixed with BiO powder and distilled water to fabricate waste matrices, which were cold-sintered at 300 °C under a uniaxial pressure of 500 MPa for 20 min to achieve a relative density of ∼98% and Vickers hardness of 1.3 ± 0.1 GPa. The utilized methodology reduced the iodine leaching rate by approximately 3 orders of magnitude through the formation of a chemically durable iodine-bearing waste form (BiOI). This study demonstrates the high potential of Bi-rGO as an innovative solution for the immobilization of radioactive waste at relatively low temperatures.
放射性废物管理对于维持核燃料循环的可持续性至关重要。在本研究中，我们提出了一种新型的铋基还原氧化石墨烯（Bi-rGO）复合材料，用于固定废气中的放射性碘。通过溶剂热法合成的这种材料具有低比表面积（2.96 m/g），在200°C时碘的最大吸附容量为1228±25 mg/g。将碘吸附剂与BiO粉末和蒸馏水混合以制备废物基体，在500 MPa的单轴压力下于300°C冷烧结20分钟，以达到约98%的相对密度和1.3±0.1 GPa的维氏硬度。所采用的方法通过形成化学稳定的含碘废物形式（BiOI）将碘的浸出率降低了约3个数量级。本研究证明了Bi-rGO作为一种在相对低温下固定放射性废物的创新解决方案具有很高的潜力。
