Al coating on U surfaces is one of the methods to protect U against environmental corrosion.The behaviors of hydrogen and oxygen impurities near the Al/α-U interface have been studied in the density functional theory framework.It tus out that U vacancies tend to segregate to the interface with segregation energies of around 0.5-0.8 eV.The segregated U vacancy can act as a sink for H and O impurities,which is saturated when filled with 8 H or 6 O atoms,respectively.Moreover,the O impurities tend to stay in the Al layer while the H impurities prefer to diffuse into the U lattice,suggesting that the Al coating can play a significant role against oxidation but not against hydrogenation of U.