A comparative study of the long-term aqueous durability of brannerite (Ce0.94Ti2O6–δ) and glass-brannerite (Fe-Al-BG-Ce0.94Ti2O6–δ) composite materials

• The corrosion resistance of Fe-Al-BG-Ce 0.94 Ti 2 O 6–δ was comparable to that of Fe-Al-BG. • Ce 0.94 Ti 2 O 6–δ exhibited preferential corrosion of Ce over Ti ions into leachate. • Aqueous corrosion resulted in the formation of a metal-hydroxide surface precipitate. • The surface alteration layer remained stable over a long exposure to deionized water. The long-term aqueous corrosion behavior of Fe-Al borosilicate glass-brannerite (Fe-Al-BG- Ce 0.94 Ti 2 O 6–δ ) composite material as a potential nuclear wasteform has been investigated to understand how the corrosion behavior of these materials can be compared to current nuclear wasteforms (i.e., borosilicate glass). It was found that the aqueous corrosion behavior of the Fe-Al-BG-Ce 0.94 Ti 2 O 6–δ composite material resulted from a combined corrosion behavior of the individual Fe-Al-BG and Ce 0.94 Ti 2 O 6–δ phases when these materials were exposed to deionized water. A combination of surface and bulk analyses has demonstrated that the surface composition and chemistry of Ce 0.94 Ti 2 O 6–δ and Fe-Al-BG-Ce 0.94 Ti 2 O 6–δ composite materials were affected by aqueous corrosion, whereas the long-range (i.e., bulk) structure of these materials remained stable over 365 days of exposure to deionized water. This study has shown that the corrosion resistance of Fe-Al-BG-Ce 0.94 Ti 2 O 6–δ composite material is comparable to Fe-Al-BG, which suggests that this composite material could be further investigated as a potential substitute for borosilicate glass nuclear wasteforms.