氧化物乏燃料锂热还原技术研究进展  

Research Progress in Lithium Thermal Reduction Technology for Oxide Spent Fuel

作　　者：徐纪瑭 姚本林 肖益群[1] 贾艳虹 孟照凯[1] 李迅[1] 杨明帅 李斌[1] 何辉[1] 叶国安[1] XU Ji-tang;YAO Ben-lin;XIAO Yi-qun;JIA Yan-hong;MENG Zhao-kai;LI Xun;YANG Ming-shuai;LI Bin;HE Hui;YE Guo-an(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413)

机构地区：[1]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《核化学与放射化学》2024年第5期409-424,I0001,共17页Journal of Nuclear and Radiochemistry

摘　　要：以电解精炼为主流的干法后处理技术虽处于实验室研究阶段,但具有可处理最广泛的燃料种类以及反应体系稳定性更高等独特优势。在电解精炼步骤前需通过电还原或热还原将氧化物乏燃料还原为金属。热还原需要使用钙、锂和镁等作为还原剂。相比其他碱金属还原,锂热还原具有回收方法简单、所需温度适中以及设备要求较低等优点,在国内外已相继进行了各方面工艺条件以及理论的研究。调研了氧化物乏燃料锂热还原研究相关进展,对比了各国锂热还原工艺的特点,结合热力学数据分析了高温锂还原的相关机理,从动力学角度对反应的影响因素进行了讨论。总结了现有研究的不足,并对未来锂热还原的趋势进行了展望,为我国干法后处理中工艺流程的研究提供参考。As a reactor which can reusing low-abundance 235U resources,fast reactor construction is an important part of China’s three-step nuclear energy process.Due to high burnup and strong irradiation of the spent fuel oxides of fast reactor,the dry reprocessing method based on molten salt electrolytic refining has unique advantages such as the ability to handle the widest range of fuel types and higher stability of the reaction system.Before the electrolytic refining step,the oxide spent fuel needs to be reduced to metal through electrical or thermal reduction.Thermal reduction requires the use of calcium,lithium,and magnesium as reducing agents.Compared with other alkali metal reduction process,lithium reduction process at high temperature has the advantages of simple recovery process,moderate temperature and lower equipment requirements,it may become the future tendency of thermal reduction.In this paper,the research progress of lithium high-temperature chemical reduction of spent fuel in dry reprocessing and compared the characteristics of lithium thermal reduction processes in various countries was investigated.The mechanism of high-temperature reduction with lithium was deduced based on thermodynamic calculation,and the influencing factors of reaction were discussed from the perspective of kinetics.Finally,the relevant research on the electrolytic recovery of residual salt from thermal reduction was described.The different reaction routes and technological process of lithium thermal reduction were summarized.The shortcomings of existing research were summarized,and the trend of lithium thermal reduction in the future was prospected.It gave a reference for the research of the process flow in China’s dry reprocessing.

关 键 词：乏燃料 干法后处理 锂热还原 熔盐体系 

分 类 号：TL24[核科学技术—核燃料循环与材料]