The oxidative decladding of UO2 fuels has been demonstrated on three-foot sections of unirradiated fuel rods and on eight-inch sections of fuel rods irradiated to 21,000 MWd/MTU. Decladding rates were unaffected by the extent of irradiation. Uranium dioxide which was unirradiated, irradiated, and with fissia added to simulate 100,000 MWd/MTU irradiation was declad at similar rates. The effect of pressure and temperature on decladding rates was determined. Puncturing the cladding greatly enhanced the rate and gave a coarser product. This product was not completely converted to U3O8 during oxidative decladding. Greater than 99.9% of the UO2 fuel was removed from the cladding. There was no detectable contamination of the product by the cladding material. Little or no fission-product or plutonium decontamination was observed. Dissolution rates for the declad product, in 50% nitric acid, were 20 times as fast as for the “as received” UO2 fuel.