Development and Qualification of a Smeared Fracture Modelling Approach for Transfers in Fractured Media

André Fourno (1) , Christophe Grenier (2) , Frédérick Delay (3) , Hakim Benabderrahmane (4)

1 IFPEN - IFP Energies nouvelles
2 LSCE - Laboratoire des Sciences du Climat et de l'Environnement [Gif-sur-Yvette]
3 LHyGeS - Laboratoire d'Hydrologie et de Géochimie de Strasbourg
4 ANDRA - Agence Nationale pour la Gestion des Déchets Radioactifs

Modelling transfers in fractured media remains a challenging task for nuclear waste storage. In this context, flow velocities around a repository are assumed very small which makes matrix diffusion to play a major role in strongly retarding mass transfers. The development and qualification of a novel smeared fracture approach adapted to these conditions is presented. Flow and transport are solved using a Mixed Hybrid Finite Element method, limited here to 2D problems for the sake of simplicity. The geometry of major fractures and matrix blocks is accounted for without handling a huge dedicated meshing. The precision of the method is studied for various test cases, mesh sizes and transport regimes. It is shown that the smeared fracture approach is accurate while limiting computational costs for transfers at low velocity typical of post closure conditions.

Domaines: Planète et Univers [physics]; Sciences de la Terre; Hydrologie

André Fourno, Christophe Grenier, Frédérick Delay, Hakim Benabderrahmane. Development and Qualification of a Smeared Fracture Modelling Approach for Transfers in Fractured Media. Groundwater in Fractured Rocks (IAH Selected Paper Series, volume 9), 2007. ⟨hal-01738122⟩