U-Pu-Zr三元合金熔盐电解精炼过程模拟  

Simulation of Molten Salt Electrorefining Process of U-Pu-Zr Ternary Alloy

作　　者：王赛 林如山[1] 张磊[1] 杜雨昕 陈志华 WANG Sai;LIN Ru-shan;ZHANGLei;DU Yu-xin;CHEN Zhi-hua(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：《核化学与放射化学》2024年第6期553-562,I0002,共11页Journal of Nuclear and Radiochemistry

摘　　要：电解精炼干法后处理技术适用于处理具有高燃耗、高钚含量、强放射性等特点的快堆乏燃料,是快堆乏燃料后处理的关键环节和现实技术选择。基于电化学理论及向后差分法,建立了U-Pu-Zr三元合金电解精炼过程模型,模拟各元素在电极附近的溶解沉积行为,分析不同传质系数及熔盐中初始铀离子浓度下的电极电势、各元素分电流及物料分布随时间的变化。结果表明:传质系数影响阳极铀钚共溶解与阴极铀锆共沉积过程中各元素的电流分配,增大传质系数可减少电能损耗;当熔盐中初始铀离子质量分数低至0.073%时,电解精炼反应45 min后阴极电位低于钚的表观氧化还原电位,钚开始在固体阴极与铀发生共沉积,两种元素的沉积呈竞争关系。The integrated closed-cycle fast reactor nuclear energy system is an important measure to accelerate the implementation of the“three-step”strategy of nuclear energy.Electrorefining dry reprocessing technology is suitable for the treatment of fast reactor spent fuel with high burn-up consumption,high plutonium content,strong radioactivity,etc.,which is a key link and practical technology choice for fast reactor spent fuel reprocessing.The fast reactor closed fuel cycle not only improves the utilization rate of uranium resources,but also reduces the radioactive activity of minor actinides,which is the only way for the sustainable development of nuclear energy.Dry reprocessing is a key part of the fast reactor closed fuel cycle,which is a realistic technology choice for fast reactor spent fuel reprocessing.Molten salt electrorefining dry reprocessing technology is a pyroprocessing technology with sufficient research and high technical maturity.In the process of research on the electrorefining process of spent fuel,the experimental research is very expensive and time-consuming,the experimental conditions and variables cannot be carried out comprehensively,and it is difficult to obtain reliable data under extreme conditions.The electrochemical changes of high-temperature molten salt electrorefining process can be explored through computer simulation,which can reduce the investment of experimental time and capital cost in the research process of electrorefining.Based on the electrochemical theory and backward difference method,a model of the electrorefining process of U-Pu-Zr ternary alloy was established,the dissolution and deposition behavior of each element near the electrode was simulated,and the changes of electrode potential,partial current and material distribution of each element under different mass transfer coefficients and uranium ion concentration in the initial molten salt were analyzed.The results show that the mass transfer coefficient affects the current distribution between the elements in the proc

关 键 词：干法后处理 熔盐电解精炼 电化学 传质系数 数学模型 向后差分法 

分 类 号：TL244[核科学技术—核燃料循环与材料]