Abstract
Low-pressure distillation has been proposed as a suitable technique for the recovery of carrier salt from molten salt reactor spent fuel. A closed-chamber distillation system, in which the pump is stopped and pressure-induced salt distillation is performed, was arranged for fluoride salt treatment. A stair-step optimization process was demonstrated to improve the recovery efficiency by up to 99%. The pressure change curve was feasible for estimating the distillation process, and a method for displaying the pressure value online in order to determine the end-point was also developed. The decontamination factor of Nd in the condensate salt was deduced to be greater than 100 with 1 wt% NdF3–FLiNaK distillation. The optimal conditions developed in this study showed a high recovery ratio for the fluoride carrier salt and a high separation efficiency for rare earth products.
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Qiang Dou and Qing-Nuan Li contributed to the study conception and design. Material preparation was performed by Jun-Xia Geng. Data collection was performed by Yang Yang. Data analysis was performed by Yan Luo. The first draft of the manuscript was written by Hai-Ying Fu, and all authors commented on previous versions of the manuscript. All authors read and approved the final manuscript.
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This work was financially supported by the National Natural Science Foundation of China (No. 21771188) and the Strategic Priority Research Program of the Chinese Academy of Sciences (No. XDA02030000). A study on some key issues regarding the Th-U fuel cycle was also funded (No. QYZDY-SSW-JSC016).
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Geng, JX., Yang, Y., Fu, HY. et al. Process optimization of a closed-chamber distillation system for the recovery of FLiNaK molten salt. NUCL SCI TECH 32, 3 (2021). https://doi.org/10.1007/s41365-020-00843-1
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DOI: https://doi.org/10.1007/s41365-020-00843-1