熔盐体系中UF4的氟化挥发工艺技术  

Fluorination Process of UF4 in Molten Salt

作　　者：孙理鑫[1,2] 程治强[1,2] 胡聪伟[1,2] 牛永生[1,2] 窦强[1,2] 李晴暖[1,2] SUN Li-xin;CHENG Zhi-qiang;HU Cong-wei;NIU Yong-sheng;DOU Qiang;LI Qing-nuan(Shanghai Institute of Applied Physics,Chinese Academy of Sciences,Shanghai 201800,China;Center of Excellence Thorium-Based Molten Salt Reactor Energy System,Chinese Academy of Sciences,Shanghai 201800,China)

机构地区：[1]中国科学院上海应用物理研究所,上海201800 [2]中国科学院先进核能创新研究院,上海201800

出　　处：《核化学与放射化学》2020年第2期78-84,共7页Journal of Nuclear and Radiochemistry

基　　金：中国科学院战略性先导科技专项资助项目(XDA02030000);国家自然科学基金青年科学基金资助项目(21501190);国家自然科学基金青年科学基金资助项目(21601201);中国科学院青年创新促进会资助项目(2016241)。

摘　　要：高温氟化挥发技术是分离回收乏燃料中铀的干法分离技术之一。在KF-ZrF 4(摩尔分数为42%-58%,FKZr)熔盐体系中进行铀氟化挥发实验,并将傅里叶红外光谱技术用于氟化过程的在线监测,通过低温多级冷凝方式收集挥发产物UF 6。氟化反应后熔盐中的铀质量分数降至2.5×10^-3%以下,UF 4的转化率高于99.9%,产物冷凝回收率达到90%以上。结果表明:红外光谱在线监测技术可用于熔盐体系铀氟化反应过程的监测,氟化挥发过程对模拟裂片元素,尤其是碱金属和稀土元素去污效果较好,去污因子为103~105。Fluoride volatility method is regarded as a promising advanced pyrochemical reprocessing technology,which can be used for separation and recovery of uranium from spent fuel.The fluorination of UF 4 by F 2 to produce UF 6 in KF-ZrF 4(x=42%-58%,FKZr)has been investigated.In this study,the Fourier transform infrared spectroscopy(FTIR)was used for in-situ monitoring of fluorination process.The product of fluorination,UF 6,was collected by the multi-stage condensation.After the fluorination,the uranium mass fraction in the molten salt is below 2.5×10^-3%,the UF 4 conversion rate is higher than 99.9%and the product recovery is above 90%.The results show that the fluorination process,and the in-situ monitoring of process by FTIR are feasible.In addition,the study also show that the fluorination has high decontamination efficiency for UF 6 product,and the decontamination factors for alkali metals and rare earth elements are 103 to 105.

关 键 词：熔盐 UF4 氟化挥发 KF-ZrF4 

分 类 号：TL244[核科学技术—核燃料循环与材料]