Luminescence properties and thermal stability of γ- and n-γ-radiation induced defects are investigated in the model ceramics synthesized based on the crystal-phase α-Al 2O 3 (corundum) and different glass-phases. The capture centers generated by γ- and n-γ-radiation in the glass-phases were found to anneal at temperatures of 500–700°C. Glow of the γ- and reactor-irradiated ceramics was observed to be caused by the centers of both crystalline- and glass-phase and corresponds to biographic defects.