Self-irradiation effects in dense and tailored porosity U1−yAmyO2−x (y = 0.10; 0.15) compounds

Dense and tailored porosity U1−yAmyO2−x (y = 0.10; 0.15) pellets were fabricated to determine the influence of the microstructure on the self-irradiation effect at room temperature due to Am α decay. A first positron annihilation lifetime spectroscopy (PALS) approach showed the presence of vacancy type defects due to the cumulative decay dose. When He fills these vacancies, a void growth and swelling can occur. In addition, accurate diameter measurements with time were performed showing that a macroscopic swelling of 1% could be attained for the high density material. The stage value seems to depend on both type and porosity level. Swelling laws describing the diameter variation have been determined.