关键词: 干法后处理, LiCl-KCl, 净化, 裂片元素, 沉淀法

Abstract:

With the rapid development of fast reactor research,dry post-treatment process has gradually become the focus of research.Molten salt electrolysis dry post-treatment is the core link and key technology of advanced nuclear fuel cycle system in the future.LiCl-KCl eutectic salt is the most commonly used molten salt system in the dry post-processing process.In order to extract actinides,lanthanides and strontium cesium elements from spent fuel,it is necessary to conduct long time electrolysis in the molten salt.In the process of separation and extraction of actinides,active fragment elements such as lanthanides,strontium and cesium accumulate in molten salt,which not only changes the physical and chemical properties of molten salt system,but also affects the purification effect of subsequent actinides products.In order to realize the reuse of solvent salt and minimize radioactive waste,it is necessary to regularly purify the lanthanide,cesium,strontium and other active fission elements in the waste molten salt.The principles,characteristics and development progress of the purification processes of lanthanide,strontium and cesium in LiCl-KCl waste molten salt by dry post-treatment were reviewed and compared,including molten salt extraction,molten salt electrolysis,precipitation and regional refining.The purification effects of lanthanide and active fragment elements such as strontium and cesium in waste molten salt were discussed in order to reuse solvent salt and reduce the generation of radioactive waste in the above process.It was pointed out that research of China′s waste salt purification will focus on maximizing the utilization of rare earth resources,protecting the environment and reducing waste emission to the greatest extent.

Key words: dry reprocessing, LiCl-KCl, purification, fission elements, precipitation method