Study of the Dissolution of Refractory PuO₂ in Nitric-Hydrofluoric Acid Dissolvents at 100°C

The dissolution of refractory PuO₂ in HNO₃-HF-H₂O dissolvents was studied. Results showed that increasing either the HNO₃ or the HF concentration increases the dissolution rate, and that formation of a Pu(IV) fluoride complex decreases the rate. It was also found that oxidation of dissolved Pu(IV) helps maintain the presence of a fluoride ion as a catalyst and is thus highly beneficial to PuO₂ dissolution.