Effect of inhomogeneity on the level of fission gas and caesium release from OCOM MOX fuel during irradiation
Two OCCOM fuels were investigated by EPMA. In one, the MOX agglomerates contained 18 wt% fissile Pu and had a volume fraction of 0.17; in the other they contained 9 wt% fissile PU and had a volume fraction of 0.34. The fuel burnup was approximately 44 GWd/t. It was found that the Pu concentration in the MOX agglomerates had decreased by about 50%, whereas in the UO(2) matrix it had increased ten-fold to approximately 2 wt%. More than 80% of the fission gas had been released from the oxide lattice of the MOX agglomerates. Most of this was retained in the pore structure of the agglomerates. Consequently, for both fuels gas release to the rod free volume increased from less than 0.5% at 10 GWd/t to a maximum of 3.5% at 45 GWd/t. Caesium showed near complete retention in the MOX agglomerates and the UO(2) matrix.
Bibliographic Reference: Article: Journal of Nuclear Materials, Vol. 228 (1996), pp. 8-17
Record Number: 199611019 / Last updated on: 1996-09-30
Original language: en
Available languages: en