Investigation of the Reduction Process of Uranium Oxide Uo to Uo for Ceramic Nuclear Fuel Production

This study investigates the effects of temperature and duration on the thermal reduction of uranium trioxide (UO) to uranium dioxide (UO) in hydrogen atmosphere for producing powdered precursors of ceramic nuclear fuel. X-ray diffraction analysis established optimal processing parameters of 500°C and 180 minutes holding time to achieve the target phase composition and stoichiometric uranium dioxide ratio. Scanning electron microscopy and X-ray diffraction demonstrated that extended holding times do not induce crystallite or secondary agglomerate growth (D = 13.4–16.1 nm). X-ray photoelectron spectroscopy confirmed achievement of the target stoichiometric composition and established uranium reduction efficiency of 82–83%. The uranium dioxide produced under optimized conditions demonstrates suitability for manufacturing ceramic nuclear fuel with superior mechanical properties via spark plasma sintering technology.