AbstractThe thermodynamic solubility of PuO2in nitric acid has been calculated, taking into account the formation of higher nitrate complexes of plutonium at higher acidities. The dissolution of PuO2in nitric acid containing hydrofluoric acid and hydrazine has been studied. The results indicate that the presence of hydrazine in nitric acid containing hydrofluoric acid aids the dissolution of PuO2. The destruction of hydrazine after the dissolution step is found to be easy.