Repository-Scale Modeling of the Long-Term Hydraulic Perturbation Induced by Gas and Heat Generation in a Geological Repository for High-and Intermediate-Level Radioactive Waste: Methodology and Example of Application (original) (raw)

2011, Transport in Porous Media

The current design of a deep geological repository for high-and intermediatelevel radioactive waste in France consists of a complex system of different underground structures (ANDRA, Dossier 2005 Argile, les recherches de l'Andra sur le stockage géologique des déchets radioactifs à haute activité et à vie longue, collection les Rapports. Châtenay-Malabry, France, 2005). For a comprehensive understanding of the long-term hydraulic evolution of the entire repository, numerical non-isothermal two-phase flow and transport simulation, taking into consideration the generation, accumulation, and release of hydrogen gas and decay heat, are compulsory. However, a detailed numerical model of the entire repository system would require a tremendous computational effort and pose a laborious task with respect to the operation of the model. To handle these difficulties, we have developed an efficient method for the numerical modeling of a complete repository system and its geologic environment. The method consists of the following steps: (i) subdivision of the repository plane into a large number of "sectors" based on the position of hydraulic seals and on other geometrical considerations, (ii) exploitation of existing symmetries (inside or between sectors), (iii) adoption of the "multiplying concept", and (iv) connection of the individual sectors at the drift interfaces to form the entire repository model. Each sector is modeled as a three-dimensional (3D) block, and the entire model is computed with TOUGH2-MP. The Electronic supplementary material The online version of this article (123 78 A. Poller et al.