Oxygen self-diffusion in massive UO2 samples was studied by means of mass spectrometry (using a spark or laser source), proton 18O(p, α)15N reaction and ionic mass analysis. At 780 to 1250C, the oxygen diffusion in stoichiometric samples was represented by:

D(cm2/s) = 0.26 exp[-59300/RT]

A marked enhancement of diffusivity with small stoichiometry deviations was observed at 800C.

J.F.Marin, P.Contamin: Journal of Nuclear Materials, 1969, 30[1-2], 16-25