The Department of Energy has a goal of decontaminating an estimated 180,000 metric tons of metal wastes in various surplus facilities. Uranium (U) and other radioactive actinides and lanthanides are embedded within the mixed oxide structures of the passivity layers of corroded iron and steel. These toxic metals can be dissolved out of the surface layers by a naturally occurring bacterial siderophore called Desferrioxamine B (DFB). DFB is a trihydroxamate ligand with one amine (pK1 =10.89) and three hydroxamate groups (pK2 =9.70, pK3 =9.03, and pK4 =8.30), which chelates with metals through hydroxamate coordination. Complexation of DFB with U can be utilized in decontamination strategy of the passivity layers. Therefore, we have been studying reactions of uranyl U(VI) with zerovalent iron (Fe0) followed by dissolution by DFB. The objectives were to determine the structure and speciation of solution and solid phases of U and to assess the effectiveness of DFB in U dissolution.