Redox reactions of U(IV) and Pu(IV) with H2O2 generated in nitric acid media by power ultrasound

Power ultrasound causes water molecule dissociation on Ho and OHo radicals due to high local temperatures and pressures generated in the cavitation threshold. In nitric acid media scavenging of OHo radicals with NO3- followed by NO3o radicals hydrolysis leads to H2O2 formation. It was shown that H2O2 generated under the effect of ultrasound with the frequency 20 kHz and intensity 1-3 Wcm-2 (Ar atmosphere) oxidizes U(IV) to U(VI) or reduces Pu(IV) to Pu(III) in 1-4 M HNO3 in the presence of antinitrous reagents ( N2H5NO3 or NH2SO3H). The effect of HNO3 concentration and ultrasonic intensity on the kinetics of U(IV) oxidation and Pu(IV) reduction was studied. (author)