Community Research and Development Information Service - CORDIS


Small specimens from the rim region (less than 200 microns from the fuel surface) of a UO(2) fuel rod with an average burnup of 7.6 % FIMA were analysed in a miniaturised galvanic cell to determine their oxygen potential. These fuel pieces represented the porous rim structure with very small grains known to be formed near the periphery of high burnup UO(2) fuel pellets. The oxygen potential of the rim material was very low, corresponding to that of unirradiated stoichiometric UO(2), or to that of slightly substoichiometric UO(2) containing rare earth fission products. No indication of oxidation due to fission was found, though most fission was that of Pu. Measurements on pieces from the inner, unrestructured fuel showed somewhat higher oxygen potentials corresponding to those of very slightly substoichiometric fuel if allowance is made for the incorporation of rare earths. These results are in contrast to some generally accepted ideas of burnup effects, and the possible reasons and implications are discussed.

Additional information

Authors: MATZKE H, JRC Karlsruhe (DE)
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 208 (1994) pp. 18-26
Availability: Nuclear Technology Publishing, PO Box 7, Ashford, Kent (GB)
ISBN: ISBN 1 870965 12 4
Record Number: 199410179 / Last updated on: 1994-11-28
Original language: en
Available languages: en