Grain and burnup dependence of spent fuel oxidation: geological repository impact
Further refinements to the oxidation model of Stout et al. have been made. The present model incorporates the burnup dependence of the oxidation rate in addition to an allowance for a distribution of grain sizes. The model was tested by comparing the model results with the oxidation histories of spent fuel samples oxidized in Thermogravimetric Analysis (TGA) or Oven Dry-Bath (ODB) experiments. The comparison between the experimental and model results are remarkably close and confirm the assumption that grain-size distributions and activation energies are the important parameters to predicting oxidation behavior. The burnup dependence of the activation energy was shown to have a greater effect than decreasing the effective grain size in suppressing the rate of the reaction U{sub 4}O{sub 9}(rightwards arrow)U{sub 3} O{sub 4}. Model results predict that U{sub 3}O{sub 8} formation of spent fuels exposed to oxygen will be suppressed even for high burnup fuels that have undergone restructuring in the rim region, provided the repository temperature is kept sufficient.
- Research Organization:
- Lawrence Livermore National Lab. (LLNL), Livermore, CA (United States)
- Sponsoring Organization:
- USDOE Office of Civilian Radioactive Waste Management (RW) (US)
- DOE Contract Number:
- W-7405-ENG-48
- OSTI ID:
- 2831
- Report Number(s):
- UCRL-JC-131592; TRN: US0101336
- Resource Relation:
- Conference: Materials Research Society 1998 Fall Meeting, Boston, MA (US), 11/30/1998--12/04/1998; Other Information: PBD: 15 Oct 1998
- Country of Publication:
- United States
- Language:
- English
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