Speaker
Description
Actinium-225 (Ac-225) is a promising alpha-emitting radionuclide for targeted alpha therapy (TAT) in cancer treat-ment, driving increasing demand for its reliable production. Accelerator-based production using thorium targets has emerged as a viable route. In particular, the RAON (Rare isotope Accelerator complex for ON-line experiments) pro-vides a facility-relevant platform for accelerator-based production of radionuclides such as Ac-225, where associated radiochemical separation and waste management challenges arise. These separation processes inevitably generate complex liquid radioactive wastes under highly acidic and multi-component conditions, posing significant challeng-es for safe handling and waste minimization in facility-relevant environments.1
In a representative separation workflow involving cation exchange resin (AG50W-X8), DGA resin, and LN resin, diverse waste streams are generated, including thorium-rich bulk waste, fission products, radium/barium isotopes, and lanthanide elements.2 These waste streams are characterized by high acidity, high ionic strength, and multi-component complexity, posing significant challenges to conventional treatment approaches. This study focuses on the optimization of multi-step chromatographic separation processes for Ac-225 purification, with an integrated per-spective on radioactive waste minimization. A process-informed analysis of waste generation is conducted to identify critical waste streams at each separation stage in terms of chemical composition, acidity, and radionuclide distribu-tion. Based on this analysis, the combination of commercially available resins and elution conditions is systemati-cally optimized to enhance Ac-225 recovery and purity while reducing the volume and complexity of generated waste. The potential incorporation of advanced separation materials is also explored to further suppress the co-elution of non-target radionuclides. This approach aims to establish a waste-conscious separation strategy that improves both process efficiency and radioactive waste management in accelerator-based isotope production systems.
[1] V. Radchenko et al., J. Chromatogr. A., 1380, 55-63 (2015).
[2] C. Tan et al., Sep. Purif. Technol. 354, 129371 (2025).