Accéder directement au contenu Accéder directement à la navigation
Article dans une revue

Coupled modeling of cement/ claystone interactions and radionuclides migration

Abstract : The interactions between cement and a clayey host-rock of an underground repository for intermediate-level radioactive waste are studied with the reactive transport code HYTEC for supporting performance assessment. Care is taken to use relevant time scales (100,000 years) and dimensions. Based on a literature review, three hypotheses are considered with respect to the mineralogical composition of the claystone and the neo-formed phases. In the long term, the pH is buffered for all hypotheses and important mineral transformations occur both in cement and the host-rock. The destruction of the primary minerals is localized close to the cement/claystone interface and is characterized by the precipitation of secondary phases with retention properties (illite, zeolite). However, beyond the zone of intense mineral transformations, the pore water chemistry is also disturbed over a dozen meters due to an attenuated but continuous flux of hydroxyl, potassium and calcium ions. Four interdependent mechanisms control the pH profile in the whole system: diffusion of the alkaline plume, mineralogical buffering, ion exchange and clogging of the pore space at the cement/claystone interface. The migration of a selected group of radionuclides (Cs, Ra, Tc and U) is explicitly integrated in the simulations of the strongly coupled system. Theoretical profiles of distribution coefficient (Kd) and solubility limit values are derived from the simulations, and their sensitivity with respect to the system evolution is estimated.
Liste complète des métadonnées

Littérature citée [29 références]  Voir  Masquer  Télécharger

https://hal-mines-paristech.archives-ouvertes.fr/hal-00596549
Contributeur : Laurent de Windt <>
Soumis le : mercredi 4 novembre 2015 - 19:49:47
Dernière modification le : jeudi 24 septembre 2020 - 16:34:19
Archivage à long terme le : : vendredi 5 février 2016 - 11:34:25

Fichier

dewindt_jch_2004-hal.pdf
Fichiers produits par l'(les) auteur(s)

Identifiants

  • HAL Id : hal-00596549, version 1

Citation

Laurent de Windt, Delphine Pellegrini, Jan van der Lee. Coupled modeling of cement/ claystone interactions and radionuclides migration. Journal of Contaminant Hydrology, Elsevier, 2004, 68, pp.165-182. ⟨hal-00596549⟩

Partager

Métriques

Consultations de la notice

390

Téléchargements de fichiers

328