Modelling engineered barriers for spent nuclear fuel repository using a double-structure model for pellets

This paper describes an experimental programme and the corresponding modelling in order to characterise the hydromechanical (HM) behaviour of pellets. At least two levels of porosity can be distinguished in the pellets: microporosity and macroporosity. In general, the microstructure is associated wi...

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Detalles Bibliográficos
Autores: Toprak, Erdem|||0000-0001-9006-3504, Olivella Pastallé, Sebastià|||0000-0003-3976-4027, Pintado, Xavier
Tipo de recurso: artículo
Fecha de publicación:2020
País:España
Institución:Universitat Politècnica de Catalunya (UPC)
Repositorio:UPCommons. Portal del coneixement obert de la UPC
Idioma:inglés
OAI Identifier:oai:upcommons.upc.edu:2117/346065
Acceso en línea:https://hdl.handle.net/2117/346065
https://dx.doi.org/10.1680/jenge.17.00086
Access Level:acceso abierto
Palabra clave:Radioactive waste disposal in the ground
Bentonite deposits
Finite-element modelling
Radioactive waste disposal
Strength & testing of materials
Abocadors de residus radioactius
Bentonita -- Propietats
Àrees temàtiques de la UPC::Enginyeria civil::Geotècnia::Mecànica de sòls
Àrees temàtiques de la UPC::Desenvolupament humà i sostenible::Enginyeria ambiental::Tractament dels residus
Àrees temàtiques de la UPC::Energies::Energia nuclear
Descripción
Sumario:This paper describes an experimental programme and the corresponding modelling in order to characterise the hydromechanical (HM) behaviour of pellets. At least two levels of porosity can be distinguished in the pellets: microporosity and macroporosity. In general, the microstructure is associated with the active clay minerals, while the macrostructure accounts for the larger-scale structure of the material. In pellets, this concept can be somewhat different as a pellet arrangement creates a large-scale macropore structure. The Barcelona expansive model is proposed to reproduce the material response through infiltration and oedometer tests. In addition to expansive model parameters, a set of hydraulic laws considering the double-structure phenomenon is necessary to perform HM analysis. This paper also describes the effect of macroporosity on the intrinsic permeability changes. To illustrate the general objectives of this research, a full-scale thermohydromechanical calculation has been done to show the capabilities of the approach. The Barcelona basic model (for clays) and Barcelona expansive model (for pellets) have been used in this full-scale calculation.