Using COMSOL for the Transport Modelling of Some Special Cases in a Bentonite Buffer in a Final Repository for Spent Nuclear Fuel

M. Olin[1], V-M. Pulkkanen[1], A. Seppälä[1], T. Saario[1], A. Itälä[1], M. Tanhua-Tyrkkö[1], and M. Liukkonen[1]

[1]VTT, Technical Research Centre of Finland, Espoo, Finland
Published in 2009

The bentonite barrier is an essential part of a safe spent fuel repository in granitic bedrock. In this work COMSOL Multiphysics® is used in modelling the Thermal (T), Hydrological (H), Mechanical (M) and Chemical (C) phenomena and processes taking place in a bentonite buffer. Special interest lies in systems in which the density of bentonite or bentonite pore water varies. Typically, variation occurs during the erosion and wetting stage of bentonite. The reason for developing COMSOL models for this purpose is the lack of commercially available software, which typically covers either THC or THM models; M and C are not modelled together.