干法后处理熔盐中Sr/Cs去除方法的研究进展

doi:10.15541/jim20250101

摘要/Abstract

摘要： 干法后处理技术具有耐辐照、防扩散和简化废物处理等特点,是未来先进快堆乏燃料后处理的优选技术。其中,熔盐电解精炼是干法后处理的核心技术,主要利用铀、钚等锕系元素与其他裂变元素在熔盐体系中的氧化还原电位差实现锕系元素的分离回收。然而,在电解精炼过程中,镧系元素和Sr/Cs等裂变元素在熔盐中不断积累,改变了熔盐的理化性质,严重影响电解精炼效率。另外,¹³⁷Sr和⁹⁰Cs等裂变产物属于水溶性长寿命核素,若处理不当,将对环境造成巨大危害。因此,有效净化熔盐中的Sr/Cs等裂变元素不仅是提高熔盐电解干法后处理效率的迫切需求,也是减少放射性废物排放的重要手段。本文总结了熔盐中的Sr/Cs去除方法的研究现状,对比分析了电解法、结晶法、减压蒸馏法、沉淀法和离子交换法等不同方法的分离原理和分离效果,并探讨了未来的发展方向及潜在的可用材料体系。

关键词: 干法后处理, 电解精炼, Sr, Cs, 熔盐净化

Abstract: Dry reprocessing technology has advantages of irradiation resistance, proliferation resistance and simplified waste treatment, thereby rendering it the preferred technology for the reprocessing of spent fuel of advanced fast reactors. Molten salt electrolytic refining serves as the core technology of dry reprocessing, primarily capitalizing on the difference in redox potential between actinides such as uranium and plutonium and other fissionable elements within a molten salt system. This technology facilitates the separation and recovery of actinides. During the electrolytic refining process, lanthanide elements and fission elements, such as Sr and Cs, tend to accumulate within the molten salt, which will change the physicochemical properties of the molten salt, thus seriously affecting the efficiency of electrolytic refining. In addition, fission products such as ⁹⁰Sr and ¹³⁷Cs are water-soluble and long-lived nuclides, posing significant environmental hazards if inadequately managed. Therefore, effective purification of fission elements such as Sr and Cs from molten salt is imperative, not only to improve the efficiency of dry reprocessing of molten salt electrolysis, but also as a crucial strategy to reduce the discharge of radioactive waste. This paper summarizes the current research status of Sr and Cs removal methods in molten salts, comparatively analyzes the separation principles and separation effects of different methods, such as electrolysis, crystallization, decompression distillation, precipitation, and ion exchange. Furthermore, it explores prospective direction of development and potentially applicability of various material systems.

Key words: dry reprocessing, electrolytic refining, Sr, Cs, molten salt purification

中图分类号:

TL24

刘占一, 李勉, 欧阳晓平, 柴之芳, 黄庆. 干法后处理熔盐中Sr/Cs去除方法的研究进展[J]. 无机材料学报, DOI: 10.15541/jim20250101.

LIU Zhanyi, LI Mian, OUYANG Xiaoping, CHAI Zhifang, HUANG Qing. Recent Progress on the Removal of Sr/Cs from Molten Salt in Dry Reprocessing[J]. Journal of Inorganic Materials, DOI: 10.15541/jim20250101.

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