In this study, ex-ADU UO2 powders are doped by small amounts of various corundum oxides such as Cr2O3, Ti2O3, Al2O3, V2O3. Doped UO2 powders were pressed up 50% theoritical density (TD) and sintered under 90% Ar + 10% H-2 atmospheres at 1700 degreesC for duration of 4 hours. Pellet densities, longitudinal and shear wave ultrasonic velocities for each pellet were measured. Average grain diameter for each pellet was found by image analysis system. Elastic properties of pellets were determined from ultrasonic measurements.