超临界流体萃取技术在乏燃料后处理中的应用  

Application of Supercritical Fluid Extraction in Reprocessing of Spent Nuclear Fuel

作　　者：朱礼洋[1] 文明芬[1] 段五华[1] 徐景明[1] 朱永[1] 

机构地区：[1]清华大学核能与新能源技术研究院,北京102201

出　　处：《化学进展》2011年第7期1308-1315,共8页Progress in Chemistry

基　　金：国家自然科学基金项目(No.21071089)资助

摘　　要：未来的动力堆乏燃料具有高燃耗、高钚含量和燃料类型多样等特点,采用传统的溶剂萃取法流程处理将面临很大挑战,而干法后处理技术虽经多年研究,仍有许多问题有待解决,因此有必要探索新的非水法后处理技术。将超临界流体萃取应用于乏燃料后处理可以简化后处理流程,大量减少二次废液的产生,具有很好的发展前景。本文综述了超临界流体萃取技术在乏燃料后处理中的应用研究,对基于超临界萃取技术的乏燃料后处理概念流程进行了评述。对将电化学插层法与超临界流体萃取技术结合,用于处理高温气冷堆乏燃料的可行性进行了讨论。PUREX process is used in the reprocessing of spent nuclear fuel（SNF） for many years.But the operation of the process produces large volume of secondary waste and encounters difficulties in dealing with new type of spent nuclear fuel in the future,such as UO2 spent fuel with higher burn up and MOX（mixed oxide） spent fuel.Supercritical fluid extraction（SFE） as a novel non-aqueous technology has potential to use in nuclear industry.The current researches on application of SFE in nuclear industry include decontamination of solid radioactive waste,volume reduction of liquid radioactive waste and reprocessing of SNF.To use SFE in the reprocessing of SNF can simplify the process and reduce the secondary waste greatly.The reprocessing conceptual flow sheets based on supercritical fluid extraction are developed in Japan and Russia,which show promising prospect to be applied in the future.It is being investigated to use supercritical fluid extraction for the reprocessing of high temperature gas cooled reactor（HTGR） SNF in INET（Institute of Nuclear and New Energy Technology,Tsinghua University）.The pebble fuel of HTGR is disintegrated by electrochemical intercalation method,and then the UO2 kernels are converted into nitrate by N2O4 and extracted by supercritical CO2 fluid containing TBP（tri-butyl phosphate）.The recovery rate of uranium is 99.93%.The experimental results indicated the possibility of using electrochemical intercalation technology and SFE technology in reprocessing of HTGR spent nuclear fuel.

关 键 词：超临界流体萃取 后处理 二次废物 高温气冷堆 电化学插层 乏燃料 

分 类 号：O615.11[理学—无机化学] TQ028.32[理学—化学]