Phase distribution of uranium in matrices obtained by co-melting basalt and uranium-containing aluminum oxide

Abstract

Safe disposal of nuclear waste is key to sustainable use of nuclear energy. Exploring safe and reliable disposal methods for nuclear waste has become a research hotspot. The phase distribution of uranium in matrices obtained by co-melting basalt and uranium-containing Al2O3 was examined for the development of a potential material for radioactive waste immobilization. The co-melting of basalt with UO3-containing Al2O3 produced matrices containing glass, plagioclase, and spinel as major phases. The highest uranium content (97 mass % UO3) was observed on the non-dissolved fragment of the Al2O3 grains. The titanium-containing complex oxide phase, supposedly, ilmenite, contained up to 62 mass % UO3. The glass phase exhibited an uneven distribution of uranium, with its content ranging ~ 5 to ~ 10 mass % UO3. Data on the leaching of uranium into H2O from the co-melt of basalt and UO3-containing Al2O3 were obtained.