The kinetics of the oxidation of irradiated uranium dioxide spheres in dry air
| Autor: | K.T. Harrison, K.T. Scott, C. Padgett |
|---|---|
| Rok vydání: | 1967 |
| Předmět: |
Arrhenius equation
Nuclear and High Energy Physics Materials science Uranium dioxide First-order reaction Analytical chemistry Activation energy Isothermal process Thermogravimetry Reaction rate symbols.namesake chemistry.chemical_compound Reaction rate constant Nuclear Energy and Engineering chemistry symbols General Materials Science Nuclear chemistry |
| Zdroj: | Journal of Nuclear Materials. 23:121-138 |
| ISSN: | 0022-3115 |
| Popis: | Apparatus is described for the remote thermogravimetry of irradiated uranium dioxide spheres. The results of isothermal oxidation in dry air at temperatures between 320° and 380° C are discussed. The oxidation is best described as a first order reaction occurring in two stages, the rate constant being higher for the second stage. The rate curves do not fit those predicted by any single model for the oxidation mechanism, possibly because of the complicating effects of grain boundaries. Neutron irradiation up to 9 % burn-up of all U atoms was not found to alter the oxidation mechanism fundamentally but produced a general slowing down of reaction rates. Thus the Arrhenius activation energy for the second stage increased from ~ 15 kcal/mole for unirradiated UO 2 to ~ 25 kcal/mole at ~ 8.5 % burn-up. |
| Databáze: | OpenAIRE |
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