Reaction Between U(IV) and Nitrous Acid Catalyzed by Plutonium

The oxidation of U(Ⅳ)by nitrous acid in the present of plutonium was studied.The influence of the concentration of nitrous acid,nitric acid,plutonium on the oxidation of U(Ⅳ)was investigated.The results show that plutonium can catalyze the reaction between U(Ⅳ)and nitrous acid.And the rate equation of the reaction between U(Ⅳ)and nitrous acid catalyzed by plutonium was obtained:-dc(U(Ⅳ))/dt=kc(U(Ⅳ))c1.3(HNO3)c1.3(NO-2),k=(0.69±0.04)L2.6/(mol 2.6·min)when the temperature was 29℃.The mechanism of the oxidation of U(Ⅳ)was discussed.