The dissolution of PuO2 prepared or calcinated at high temperature has been a difficult task. It is shown that crystalline PuO2 is very difficult to dissolve in nitric acid solution, and insoluble in nitric acid solution below about 4 mol/L. Now the electrochemical method is frequently used in the dissolution of The dissolution of PuO2 prepared or calcinated at high temperature has been a difficult task. It is shown that crystalline PuO2 is very difficult to dissolve in nitric acid solution, and insoluble in nitric acid solution below about 4 mol / L. Now the electrochemical method is frequently used in the dissolution of