Crystallographic and oxidation kinetic study of uranium dioxide by high temperature X-ray diffractometry
Creators
- 1. UNESP, Presidente Prudente (Brazil). Inst. de Planejamento e Estudos Ambientais
- 2. Instituto de Pesquisas Energeticas e Nucleares, Sao Paulo (Brazil)
Description
The structural transformation of UO2 sintered plates is studied as a function of temperature using X-ray diffractometry. The thermal expansion coefficient of UO sub(2.05) is determined and the structural transformation during isothermal oxidation is observed. The results favored a oxidation mechanism in which the rate-controling process is the diffusion of oxigen through the product layer of the new phase. Activation energies for the oxidation of UO2 to UO sub(2.25) are found for different crystallographic planes (h,k,l). From this one can conclude that there is a preferential occupation of interstitial oxygen atoms within the UO2 structure. (Author)
Abstract (Portuguese)
The structural transformation of UO₂ as a function of temperature is studied using X‑ray diffractometry. The thermal expansion coefficient of UO₂.₀₅ is determined, and the structural transformation during isothermal oxidation is observed. The results support an oxidation mechanism in which the rate‑controlling step is the diffusion of oxygen through the product layer of the new phase. Activation energies for the oxidation of UO₂ to UO₂.₂₅ are determined for different crystallographic planes (h, k, l). It is concluded that there is preferential occupation of interstitial oxygen atoms within the UO₂ structure. (ARHC)
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Additional details
Publishing Information
- Imprint Pagination
- 12 p.
- Report number
- INIS-BR--23
INIS
- Country of Publication
- Brazil
- Country of Input or Organization
- Brazil
- INIS RN
- 14770870
- Subject category
- S37: INORGANIC, ORGANIC, PHYSICAL AND ANALYTICAL CHEMISTRY;
- Descriptors DEI
- ACTIVATION ENERGY; CHEMICAL REACTION KINETICS; HIGH TEMPERATURE; ISOTHERMAL PROCESSES; OXIDATION; URANIUM DIOXIDE; X-RAY DIFFRACTION
- Descriptors DEC
- ACTINIDE COMPOUNDS; CHALCOGENIDES; CHEMICAL REACTIONS; COHERENT SCATTERING; DIFFRACTION; ENERGY; KINETICS; OXIDES; OXYGEN COMPOUNDS; REACTION KINETICS; SCATTERING; URANIUM COMPOUNDS; URANIUM OXIDES