This work studied a process to recover uranium from contaminated (U,Gd)O 2 scraps generated from nuclear fuel fabrication processes by using the dissolution of (U,Gd)O 2 scraps in a carbonate with H 2 O 2 and the precipitation of the dissolved uranium as UO 4 . The dissolution characteristics of uranium, Gd, and impurity metal oxides were tested, and the behaviors of UO 4 precipitation and Gd solubility were evaluated with changes of the pH of the solution. A little Gd was entrained in the UO 4 precipitate to contaminate the uranium precipitate. Below a pH of 3, the uranium dissolved in the form of uranyl peroxo-carbonato complex ions in the carbonate solution was precipitated as UO 4 with a high precipitation yield, and the Gd had a very high solubility. Using these characteristics, the Gd-contaminated UO 4 could be purified using dissolution in a 1-M HNO 3 solution with heating and re-precipitation upon addition of H 2 O 2 to the solution. Finally, an environmentally friendly and economical process to recover pure uranium from contaminated (U,Gd)O 2 scraps was suggested.