An electron microscopy study of the RIM structure of a UO(2) fuel with a high burnup of 7.9% FIMA
Transmission and high resolution scanning electron microscopy were used to analyse the microstructure of the periphery of a UO(2) pellet irradiated to a cross section average burnup of 7.9% FIMA with a period of increased temperature at about half the final burnup. Local burnups at the pellet surface reached nearly 23% FIMA. In this rim region the original grains of about 10 µm diameter were subdivided into about 10000 subgrains of 0.15 to 0.30 µm diameter. The spread in subgrain orientation was small. The typical small fission gas bubbles present in the cold part of UO(2) irradiated to lower burnups of 40 GWd/tM were not found in this zone. The centre of the same cross section showed no grain subdivision. The high burnup structure extended to a depth of 1.65 mm.
Bibliographic Reference: Article: Journal of Nuclear Materials (1996)
Record Number: 199710227 / Last updated on: 1997-04-01
Original language: en
Available languages: en