UO2, NpO2 and PuO2 preparation in aqueous nitrate solutions in the presence of hydrazine hydrate

It was established that heating to 90 degrees C of nitrate solutions of U, Np and Pu in the presence of hydrazine hydrate results in the formation of hydrated dioxides of these elements. On ignition under inert or reducing conditions in the temperature range of 280-800 degrees C hydrated uranium dioxide transmogrify into crystalline UO2. On ignition in air atmosphere UO2 center dot nH(2)O turns into UO3 at 440 degrees C and into U3O8 at 570-800 degrees C. It was shown that thermolysis of the solution containing a mixture of uranium, neptunium and plutonium nitrates at 90 degrees C in the presence of hydrazine hydrate allows one to prepare hydrated dioxides (U, Np, Pu)O-2 center dot nH(2)O which on heating to similar to 300 degrees C transmogrify into crystalline product of UO2, NpO2 and PuO2 solid solution. The technique of preparation of solid solutions of U and Pu dioxides is very promising as simple and effective method of production of MOX-fuel for.