Journal of Hazardous Materials, Vol.287, 207-216, 2015
Perovskite-Ni composite: A potential route for management of radioactive metallic waste
Management of nickel - based radioactive metallic wastes is a difficult issue. To arrest the release of hazardous material to the environment it is proposed to develop perovskite coating for the metallic wastes. Polycrystalline BaCe0.8Y0.2O3-delta perovskite with orthorhombic structure has been synthesized by sot-gel route. Crystallographic analyses show, the perovskite belong to orthorhombic Pmcn space group at room temperature, and gets converted to orthorhombic Incn space group at 623 K, cubic Pm3m space group (with a = 4.434 angstrom) at 1173 K and again orthorhombic Pmcn space group at room temperature after cooling. Similar observations have been made from micro-Raman study as well. Microstructural studies of BaCe0.8Y0.2O3-delta-NiO/Ni composites showed absence of any reaction product at the interface. This suggests that both the components (i.e. perovskite and NiO/Ni) of the composite are compatible to each other. Interaction of BaCe0.8Y0.2O3-delta-NiO/Ni composites with simulated barium borosilicate waste glass melt also did not reveal any reaction product at the interfaces. Importantly, uranium from the waste glass melt was found to be partitioned within BaCe0.8Y0.2O3-delta perovskite structure. It is therefore concluded that BaCe0.8Y0.2O3-delta can be considered as a good coating material for management of radioactive Ni based metallic wastes. (C) 2015 Elsevier B.V. All rights reserved.
Keywords:Metallic radioactive waste;Nuclear waste vitrification furnace;Ni based alloys;Immobilization