1. Pyrochlore glass-ceramics for the immobilization of molybdenum-99 production wastes: Demonstrating scalability and flexibility to waste stream variance.
- Author
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Farzana, Rifat, Zhang, Yingjie, Dayal, Pranesh, Aly, Zaynab, Holmes, Rohan, Triani, Gerry, Vance, Eric R., and Gregg, Daniel J.
- Subjects
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GLASS-ceramics , *PYROCHLORE , *ENERGY dispersive X-ray spectroscopy , *ISOSTATIC pressing , *REFLECTANCE spectroscopy , *SCALABILITY - Abstract
[Display omitted] Pyrochlore glass ceramics have been fabricated via in-situ crystallization under reducing conditions by both sintering and hot isostatic pressing (HIPing) as candidate wasteforms for the acidic waste biproduct of Mo-99 radiopharmaceutical production. The tailored wasteform demonstrates flexibility in the wasteform design to receive the required waste variability, it also suitably passes high-level waste performance requirement, and successfully scales to 1 kg scale with 45 wt.% waste loading. U-rich pyrochlore as the major phase was confirmed by X-ray diffraction, scanning electron microscopy and energy dispersive X-ray spectroscopy, with residual glass and minor secondary phases. The presence of both U4+ and U5+ valences in the wasteforms was revealed by diffuse reflectance spectroscopy. Addition of glass content had little influence on the pyrochlore composition but facilitated minor perovskite formation. The up-scaled dense, HIPed sample showed elemental releases of < 2 g/L for all elements in durability experiments. [ABSTRACT FROM AUTHOR]
- Published
- 2021
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