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Impact of platinum group metals (Ru, Pd, Rh) on the dissolution of UO2
- Source :
- Journal of Nuclear Materials, Journal of Nuclear Materials, Elsevier, 2020, 528, pp.151836. ⟨10.1016/j.jnucmat.2019.151836⟩, Journal of Nuclear Materials, 2020, 528, pp.151836. ⟨10.1016/j.jnucmat.2019.151836⟩
- Publication Year :
- 2020
- Publisher :
- Elsevier BV, 2020.
-
Abstract
- International audience; The effect of metallic particles containing Platinum Group Metal (PGM) elements on the dissolution of sintered UO2 samples was examined through the development of multiparametric dissolution tests on sintered UO2 and UO2 + 3 mol.% PGM samples. This effect was found to be more important for CHNO3 < 1 mol L−1 whereas it was lowered for higher nitric acid concentrations due to the preponderant oxidation of U(IV) by nitrate ions. Increase of the normalised dissolution rate of the ceramics was associated to the presence of PGM elements along with the decrease of the duration of the induction period (the stronger effect being observed for ruthenium). Simultaneously, the decrease of the apparent activation energy associated to the reaction of dissolution supported the existence of catalytic effect. This latter was connected to redox reaction between the metallic particles and nitrate ions either in solution or at the PGM/UO2/solution interface. The involved reactions induced the formation of nitrogen species close to the PGM bearing particles. Among them, nitrous acid played an important role due to its strong oxidative power regarding to U(IV). Additionally, no synergistic effect was evidenced when mixing the three PGM elements.
- Subjects :
- Nuclear and High Energy Physics
Induction period
Inorganic chemistry
chemistry.chemical_element
02 engineering and technology
[CHIM.INOR]Chemical Sciences/Inorganic chemistry
01 natural sciences
Redox
010305 fluids & plasmas
Metal
chemistry.chemical_compound
Nitric acid
0103 physical sciences
General Materials Science
Dissolution
Nitrous acid
fungi
[CHIM.MATE]Chemical Sciences/Material chemistry
Platinum group
021001 nanoscience & nanotechnology
Ruthenium
Nuclear Energy and Engineering
chemistry
visual_art
visual_art.visual_art_medium
0210 nano-technology
[CHIM.RADIO]Chemical Sciences/Radiochemistry
Subjects
Details
- ISSN :
- 00223115
- Volume :
- 528
- Database :
- OpenAIRE
- Journal :
- Journal of Nuclear Materials
- Accession number :
- edsair.doi.dedup.....74fbbd50e947080a8ed503e5e1d8feeb