Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
9793577 | Journal of Nuclear Materials | 2005 | 14 Pages |
Abstract
The low temperature matrix swelling of UO2 fuels was analysed as a function of burn-up, taking into account changes in the fuel density, porosity and retained Xe concentration as measured by EPMA. The evaluation of these data combined with an analytical solution to a rate-theory model for gas-driven swelling leads to the conclusion that at average pellet burn-ups ⩽ 60 GWd/t M the total matrix swelling rate is gradually reduced from â1% per 10 GWd/t M to â0.3% per 10 GWd/t M; the latter value being reached at an average burn-up above 110 GWd/t M. The decrease in the swelling rate is due to the progressive depletion of fission gas in the fuel matrix by thermal and athermal processes, such that at very high burn-up the matrix swelling becomes dominated by the precipitation of solid fission products. Owing to volume conservation, the volume occupied by the depleted gas is replaced by porosity.
Related Topics
Physical Sciences and Engineering
Energy
Nuclear Energy and Engineering
Authors
J. Spino, J. Rest, W. Goll, C.T. Walker,