Synthesis and Morphological Control of UO 2 F 2 Particulates.

Uranium-based microspheres are of interest due to their potential applications as targets for medical isotopes production, as fuel for nuclear reactors, and as standardized materials for nuclear forensics. Here, for the first time, UO 2 F 2 microspheres (1-2 μm) have been prepared from the reaction between UO 3 microspheres and AgHF 2 in an autoclave. In this preparation, a new fluorination method has been applied, and HF (g) -produced in situ from the thermal decomposition of AgHF 2 and NH 4 HF 2 -was used as the fluorinating agent. The microspheres were characterized by powder X-ray diffraction (PXRD) and scanning electron microscopy (SEM). Diffraction results indicated that the reaction performed with AgHF 2 at 200 °C led to anhydrous UO 2 F 2 microspheres, while at 150 °C, hydrated UO 2 F 2 microspheres were obtained. Meanwhile, NH 4 HF 2 led to the formation of contaminated products as driven by the formation of volatile species.