Article Dans Une Revue Journal of Nuclear Materials Année : 2025

Buffering the oxygen activity of uranium dioxide fuels using niobium and molybdenum as redox additives

Résumé

We demonstrate that it is possible to control the oxygen activity of a uranium oxide fuel by incorporating additives during the manufacturing process that have a strong redox activity. To this end, we have studied the macroscopic electrochemical properties of three polycrystalline uranium dioxide samples, the first containing both molybdenum and molybdenum dioxide, the second containing niobium dioxide and the last containing no additives other than impurities. During experiments, samples were subjected to reducing and subsequently oxidizing atmospheres with respect to the oxygen partial pressure at which the oxidized and reduced forms of the additives are in equilibrium. In situ monitoring of the electrochemical response of the samples reveals that the presence of redox couples involving either niobium or molybdenum significantly modifies the oxygen activity of a uranium dioxide solid. Scanning Electron Microscopy (SEM), Electron Back-Scatter Diffraction (EBSD) and Energy Dispersive X-ray analysis (EDX) prior to and following the high temperature measurements, confirm the in situ data: the final microstructure purports to show that the electrochemical activity is controlled by the Mo/MoO2 and the NbO2/Nb2O5 couples for the molybdenum and niobium containing samples respectively.

Domaines

Chimie Matériaux
Fichier principal
Vignette du fichier
JNUMA-D-24-01059_R1b.pdf (15) Télécharger le fichier
Origine Fichiers produits par l'(les) auteur(s)

Dates et versions

Identifiants

Citer

Philippe Garcia, Erwin Douguet-Bronnec, Franck Fournet-Fayard, Florian Le Hello, Xavière Iltis, et al.. Buffering the oxygen activity of uranium dioxide fuels using niobium and molybdenum as redox additives. Journal of Nuclear Materials, 2025, 607, pp.155647. ⟨10.1016/j.jnucmat.2025.155647⟩. ⟨hal-04958346⟩
0 Consultations
0 Téléchargements

Altmetric

Partager

More