碱性体系下乏燃料氧化溶解行为与机理研究进展  

Research progress on oxidation dissolution behavior and mechanism of spent fuel in an alkaline system

作　　者：侯晨曦 何明键 方豪凡 矫彩山[1] 何辉 HOU Chenxi;HE Mingjian;FANG Haofan;JIAO Caishan;HE Hui(College of Nuclear Science and Technology, Harbin Engineering University, Harbin 150001, China;Department of Radiochemistry, China Institute of Atomic Energy, Beijing 102413, China)

机构地区：[1]哈尔滨工程大学核科学与技术学院,黑龙江哈尔滨150001 [2]中国原子能科学研究院放射化学研究所,北京102413

出　　处：《哈尔滨工程大学学报》2022年第6期907-914,共8页Journal of Harbin Engineering University

基　　金：国家自然科学基金核技术创新联合基金项目(U1967219).

摘　　要：碳酸盐体系下的乏燃料后处理流程,具有流程短、安全性高、废物量少且易于处理等优势,特别适合高燃耗乏燃料的处理。其中乏燃料在碱性条件下的氧化溶解是此类流程的关键步骤。为了准确探讨该工艺步骤的研究现状,本文对碱性体系下乏燃料氧化溶解行为与机理方面的研究进行了调研。结果表明:该体系普遍选择Na_(2)CO_(3)或NH_(4)CO_(3)作为溶解介质,以H_(2)O_(2)作为氧化剂。U(IV)在溶解过程中被氧化为UO^(2+)_(2)后与O^(2-)_(2)及CO^(2-)_(3)等配体形成配合物,该溶解过程与pH值、温度、辐照与超声作用等多种化学与物理因素有关。其中辐照或超声条件下产生的·OH对UO_(2)的氧化溶解有较大的促进作用。而对于辐照条件下溶解速率与吸收剂量等参数间关系,碱性条件下的溶解速率模型等基础研究工作仍需进一步深入研究。Alkaline spent fuel reprocessing based on the carbonate system is a brief process with high safety,minimal waste,and ease of operation.Therefore,this process is suitable for the treatment of high burning spent fuel.Particularly,the oxidative dissolution of spent fuel under alkaline conditions is a key step in this process.To accurately discuss the research status of this key step during the alkaline process,the oxidation and dissolution behavior and the mechanism of spent fuel in the alkaline system were investigated.Results show that Na_(2)CO_(3)and NH_(4)CO_(3)are generally selected as the dissolution medium and H_(2)O_(2)as the oxidant.U(IV)is oxidized to UO^(2+)_(2)in the dissolution process and complexes with O^(2-)_(2)and CO^(2-)_(3)ligands.The dissolution process is affected by various chemical and physical factors,such as pH value,temperature,radiation,and ultrasound.·OH generated from irradiation or ultrasonic can significantly promote the oxidative dissolution of UO_(2).However,basic research work,such as the relationship between dissolution rate and absorbed dose under irradiation conditions and the dissolution rate model under alkaline conditions,warrants enhancement.

关 键 词：乏燃料后处理 碱性体系 铀氧化物 碳酸盐 影响因素 氧化溶解 机理 

分 类 号：TL24[核科学技术—核燃料循环与材料]