离子液体在核燃料后处理中的应用

Application of ionic liquids in nuclear fuel reprocessing

核燃料后处理是核燃料循环的核心,对于核环境安全和核能的可持续发展意义重大.离子液体作为"新一代绿色溶剂"在核燃料后处理中具有广阔的潜在应用前景.离子液体可以替代易挥发的有机溶剂用于水法后处理萃取分离放射性核素,也可以替代强腐蚀性的高温熔盐用于干法后处理电解回收金属离子.本文在作者工作基础上总结了近年来离子液体用于核燃料水法和干法后处理的基础研究成果,归纳和分析了其中的关键科学问题.此外,由于核燃料后处理涉及强辐射应用环境,离子液体的辐射稳定性是其实际应用的前提和关键,因此本文还综述了国内外有关离子液体辐射效应的研究进展,评估了离子液体用于核燃料后处理的辐射化学可行性.最后,基于当前的研究现状和研究水平展望了离子液体在核燃料后处理应用方面的研究前景.

The nuclear fuel reprocessing, as the essential part of nuclear fuel cycle, is of great significance from the point of view of both nuclear safety and sustainable development of nuclear energy. Room temperature ionic liquids （RTILs） regarded as ＂new generation green solvents＂ have recently received an ever-increasing amount of interest in nuclear fuel reprocessing due to their unique physical and chemical properties. They can be used in aqueous reprocessing as environmentally benign alternatives to volatile organic solvents for traditional liquid-liquid extraction of high level radioactive nuclides. They are also applicable in non-aqueous reprocessing by substituting caustic molten salts for electro-deposition of metal ions. Herein, we reviewed the recent basic researches on the utility of RTILs in nuclear fuel reprocessing, from which the key scientific issues on their practical application were summarized. In addition, it is well known that nuclear fuel reprocessing involves high-level radioactive matter, and full realization of the potential application of RTILs in nuclear fuel reprocessing requires a comprehensive knowledge of stability and properties of RTILs under radiation. Therefore, the recent investigations of radiation effects on RTILs were also selectively described in this paper, and the feasibility of RTILs as alternative media for separations of highly radioactive nuclides from spent nuclear fuel was assessed from the radiation chemistry aspect. Finally, further basic studies on the application of RTILs in the nuclear fuel reprocessing were prospected.