Corrosion modelling of iron for long term prediction in nuclear waste repository
Résumé
The long-term behavior of nuclear waste canisters in geological repository depends on metallic materials and geochemical features of the surrounding. In clay, H$_2$ and metallic cations induce geochemical transformations which change pH and redox potential. So the 1000-years behavior of canisters could be predicted in linking geochemical and corrosion models.
The Diffusion Poisson Coupled Model has been proposed as corrosion model for passive iron. To ensure feedback from geochemistry on corrosion rate backward reactions were introduced. It's a mechanistic model involving 40 parameters to solve the Poisson Fick equations in moving boundaries situation. The purpose of this paper is to present the strategy adopted to set up parameters of DPCM.
It has been shown that one half of these parameters could be evaluated from equilibrium considerations. Then specific experiments could be simulated to set up this or that parameters. For instance, dissolution rate of magnetite layer monitored by XANES, layer thickness growth monitored by ellipsometry, potentiostatic and Mott-Schottky experiments have been simulated to set up parameters of dissolution and release processes, inner oxide growth and electrostatic description of outer interface. This strategy was efficient because DPCM can simulated a large panel of stationary and non-stationary experiments.
Fichier principal
201600000382.pdf (267.07 Ko)
Télécharger le fichier
201600000382_annexe.pdf (1.09 Mo)
Télécharger le fichier
Origine : Fichiers produits par l'(les) auteur(s)
Origine : Fichiers produits par l'(les) auteur(s)