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Radiation-Resistant Betaine Hydrochloride for Facile Ln/An Group Separation via Selective Dissolution

  • Zhuo-Fan Jin 1,2,   
  • He-Xiang Jia 1,2,   
  • Bing-Qing Wei 1,2,   
  • Qing-Gang Huang 1,   
  • De-Sheng Chen 1,   
  • Xiao-Jie Yin 1,   
  • Shi-Wei Cao 1,   
  • Zhi Qin 1 and 
  • Fang-Li Fan 1,*

Received: 06 July 2026 | Revised: 06 September 2026 | Accepted: 23 October 2026 | Published: 02 November 2026

Abstract

The separation of lanthanide (Ln) fission products from actinide (An) matrices is essential for reducing neutron poisons and improving spent nuclear fuel reprocessing. Herein, aqueous betaine hydrochloride (HbetCl) is developed as a radiation-resistant, single-component medium for facile Ln/An group separation through selective dissolution. Under mild conditions, HbetCl efficiently dissolves lanthanide sesquioxides (Ln2O3) from simulated spent nuclear fuel, achieving over 95% Ln removal, while actinide dioxides remain largely undissolved and can be directly recovered as solid residues by simple centrifugation. The separation performance is well preserved after γ-irradiation up to 1000 kGy, as demonstrated by the nearly 97% leaching of neodymium (Nd). In contrast, AnO2 exhibits strong resistance toward HbetCl dissolution. In particular, experiments using radioactive 243AmO2 further confirm that the selective-dissolution strategy is applicable not only to UO2-based matrices but also to representative minor actinide oxides, highlighting its relevance to practical spent-fuel reprocessing. Density functional theory (DFT) calculations indicate that betaine (BET) facilitates Ln2O3 dissolution by stabilizing dissolved lanthanide species through hydrogen-bonding interactions, thereby providing molecular-level insight into the selectivity of the process. Overall, the radiation-resistant HbetCl enables a mild, simple, and efficient route for Ln/An group separation by preferentially transferring lanthanides into solution while retaining actinides in the solid phase. This strategy reduces actinide carryover into the liquid phase and provides a promising platform for advanced spent nuclear fuel reprocessing toward a closed nuclear fuel cycle.

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Jin, Z.-F.; Jia, H.-X.; Wei, B.-Q.; Huang, Q.-G.; Chen, D.-S.; Yin, X.-J.; Cao, S.-W.; Qin, Z.; Fan, F.-L. Radiation-Resistant Betaine Hydrochloride for Facile Ln/An Group Separation via Selective Dissolution. Modern Nuclear and Radiochemistry 2026, 1 (1), 4.
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