Title:
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Analysis of unsaturated materials hydration incorporating the effect of thermo-osmotic flow
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Author:
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Sánchez, Marcelo; Arson, Chloé; Gens Solé, Antonio; Aponte, Fernando
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Other authors:
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Universitat Politècnica de Catalunya. Departament d'Enginyeria Civil i Ambiental; Universitat Politècnica de Catalunya. MSR - Mecànica del Sòls i de les Roques |
Abstract:
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The geological disposal of a high level radioactive waste relies in a system composed of engineered and geological barriers. The soils and rocks involved in the design of this type of solution are generally initially unsaturated and subject to complex thermal, hydraulic and mechanical (THM) coupled phenomena triggered by the simultaneous heating and hydration of the barrier materials under confined conditions. Mathematical THM formulations are typically used to analyze the behavior and long term performance of the barriers system. These types of formulations generally do not include some coupled processes, for example thermo-osmosis (i.e. the movement of liquid water induced by gradient of temperature), because they are considered not significant when compared against the main or direct processes (e.g., Darcy’s, Fourier’s and Fick’s laws). In this work, the potential effects of thermo-osmotic phenomenon is studied in detail. Typical flow equations are modified to include thermo-osmotic flows and then they are implemented in numerical simulators. Two case studies are analyzed. The first one focuses on a simple and already proposed model to study the behavior of a geological barrier for nuclear waste when subjected to heating and hydration. The other case corresponds to the study of an engineered clay barrier material in the laboratory subjected to hydraulic and thermal gradients similar to the ones expected in real repository conditions. In both cases the analyses with and without thermo-osmotic flows are compared. From these comparisons it is observed that the effect of thermo-osmosis can be quite significant. Thermo-osmotic effects also assisted to explain the apparent low wetting observed in the hydration of a clayey barrier material. |
Abstract:
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Peer Reviewed |
Subject(s):
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-Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament dels residus -Àrees temàtiques de la UPC::Energies::Energia nuclear -Radioactive waste disposal in the ground -Thermo-osmotic flow
Unsaturated material
THM coupled phenomena
Compacted expansive clay
Nuclear waste disposal
Numerical modeling -Residus radioactius -- Eliminació en el sòl |
Rights:
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http://creativecommons.org/licenses/by-nc-nd/3.0/es/ |
Document type:
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Article - Submitted version Article |
Published by:
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Elsevier
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