Radiation stability of titanate ceramics suggested for actinide-bearing waste immobilization was studied. The major actinide (uranium) hosts in the samples prepared by melting followed by crystallization in a resistive furnace and in a cold crucible are phases with fluorite-related structure (zirconolite, pyrochlore, murataite) as well as brannerite. Critical amorphization doses at room temperature for these phases irradiated with 1 MeV Kr+ ions were (× 1018 ions/m2) ∼3, 1.8–2.4, 1.7–1.9, and 1.4 for zirconolite, pyrochlore, murataite, and brannerite, respectively. Murataite varieties with three-, five-, and eight-fold fluorite cells have the similar radiation stability. Recalculation of critical amorphization dose to dpa estimates a time required for murataite amorphization as 600–700 years at 10 wt.% 239Pu content. Similar values have been established previously for pyrochlore-structured titanates proposed for plutonium immobilization (because there will be also some commercial Pu issue).

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