硝酸中二氧化铀溶解行为与机理研究进展  

Research progress on dissolution behavior and mechanism of uranium dioxide in nitric acid

作　　者：房帆 姚本林 肖益群[1] 贾艳虹 陈辉[1] 李斌[1] 何辉[1] FANG Fan;YAO Benlin;XIAO Yiqun;JIA Yanhong;CHEN Hui;LI Bin;HE Hui(Department of Radiochemistry,China Institute of Atomic Energy,Beijing 102413,China)

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：《无机盐工业》2024年第9期34-43,共10页Inorganic Chemicals Industry

摘　　要：乏燃料的首端溶解是Purex流程的关键步骤,该步骤产生的料液直接影响后续的铀钚回收及分离效果。二氧化铀是乏燃料的主要成分,要实现乏燃料的有效溶解,必须要对二氧化铀的溶解行为及机理进行系统研究。首先,以二氧化铀与硝酸的基本反应为基础,结合对反应中产生气体的分析,探讨了氧化溶解的机理和溶解过程中亚硝酸的自催化作用,并系统分析了亚硝酸浓度、硝酸浓度、温度和芯块形态对二氧化铀溶解过程的影响;然后,介绍了二氧化铀在硝酸中溶解模型的研究进展,并对模型的适用性进行了探讨;最后,讨论了当前二氧化铀在硝酸中的溶解研究存在的主要问题,并对未来的发展方向进行了展望。The dissolution of spent fuel is the head⁃end step in the Purex process,as the resulting feed liquid directly im⁃pacts the subsequent recovery and separation of uranium and plutonium.Spent fuel primarily consists of uranium dioxide,thus it is imperative to systematically investigate the dissolution behavior and mechanism of this compound for effective dis⁃solution.By examining the fundamental reaction between uranium dioxide and nitric acid,as well as analyzing the gas gener⁃ated during this reaction,the mechanism of oxidation dissolution and autocatalysis of nitrous acid in the dissolution process were discussed.The effects of nitrous acid concentration,nitric acid concentration,temperature and pellet shape on the dis⁃solution process of uranium dioxide were systematically analyzed.Then the research progress of uranium dioxide dissolution model in nitric acid was introduced,and the applicability of the model was discussed.Finally,the main problems existing in the current research on the dissolution of uranium dioxide in nitric acid were discussed,and the future development direc⁃tion was prospected.

关 键 词：二氧化铀 溶解机理 溶解动力学 硝酸溶液 影响因素 

分 类 号：TQ133.4[化学工程—无机化工]