Numerical Simulations of Radionuclide Transport through Clay and Confining Units in a Geological Repository using COMSOL
J. Hansmann, M. L. Sentis, B. J. Graupner, A.-K. Leuz, C. Belardinelli
Swiss Federal Nuclear Safety Inspectorate (ENSI), Brugg, Switzerland
Kantonsschule Solothurn, Solothurn, Switzerland
Introduction: The sectoral plan that defines the procedure and criteria of site selection for deep geological repositories for all categories of waste (high-level and low- and intermediate-level waste) in Switzerland started in 2008 and will last for about ten years. ENSI (Swiss Nuclear Safety Inspectorate) is in charge of reviewing the proposals and safety assessments for geological ...
P. Vincent, E. Humphreys
College of Earth, Ocean, & Atmospheric Sciences, Oregon State University, Corvallis, OR, USA
Department of Geological Sciences, University of Oregon, Eugene, OR, USA
Introduction: Lithospheric delamination beneath the western U.S. is believed to be the driving mechanism responsible for the evolution of magmatic and topographic features observed at the surface in the western U.S.. This process requires hot asthenosphere to be in contact with the underside of cold sub-crustal lithosphere and believed to be initiated by the Yellowstone hot spot plume that due ...
Underground Coal Fire Extinction Model Using Coupled Reactive Heat and Mass Transfer Model in Porous Media
S. Suhendra, M. Schmidt, and U. Krause
Laboratory II.2: “Flammable Bulk Materials and Dusts, Solid Fuels”, Federal Institute for Materials Research and Testing (BAM), Berlin, Germany
Green house gases emission associated with natural hazard of underground coal seam fire has been recognized as a worldwide problem leading to global warming threat. Therefore, in this paper a model to study underground coal fire is presented and the results will be devoted to strategic development of coal fire extinction technology within the framework of Sino-German Coal Fire Research ...
M. Richter, S. Moenickes, O. Richter, T. Schröder
BASF SE, Agricultural Center, Limburgerhof, Germany
Institute of Geoecology, TU Braunschweig, Braunschweig, Germany
In a soil pore, water flows through the biofilm, where the density of the latter was assumed to represent a flow resistance. This mechanism was implemented as a local change of fluid viscosity proportional to local biofilm density. It was assumed that diffusive substrate transport is possible through the biofilm region such that the biofilm was able to degrade the substance. Maximum flow ...
COMSOL Multiphysics, TOUGHREACT and Numerrin Comparison in Some Modelling Tasks of Spent Nuclear Fuel Disposal
A. Itälä, V-M. Pulkkanen, M. Laitinen, M. Tanhua-Tyrkkö, and M. Olin
VTT Technical Research Centre of Finland, Espoo, Finland
Numerola Oy, Jyväskylä, Finland
Bentonite clay is used as a protecting barrier around both the copper capsules in deposition holes and in deposition tunnels in the KBS-3 final disposal concept for spent nuclear fuel. The performance of these bentonite barriers will be investigated both experimentally and by modelling. Both approaches are needed, because for example the time span in question (hundred thousand years or even ...
Coupled Gas Flow and Thermal and Reactive Transport in Porous Media for Simulating Waste Stabilization Phenomena in Semi-Aerobic Landfill
H. Ishimori, K. Endo, T. Ishigaki, H. Sakanakura, and M. Yamada
National Institute for Environmental Studies
Semi-aerobic landfill has interesting structure that passively provides the atmospheric oxygen into landfilled waste due to the heat convection generated by the decomposition of landfilled waste. There are limited studies on the mechanisms of the oxygen transport. This paper presents the governing equations and parameter estimation methods for the numerical simulation of the gas fluid flow and ...
Extraction of Thermal Characteristics of Surrounding Geological Layers of a Geothermal Heat Exchanger by COMSOL Multiphysics® Simulations - new
N. Aranzabal, J. Martos, J. Soret, J. Torres, R. García-Olcina, Á. Montero
Technical School of Engineering, University of Valencia, Valencia, Spain
Department of Applied Physics, Politechnical University of Valencia, Valencia, Spain
It has been demonstrated that is possible obtain the thermal parameters of geological layers of a BHE (Borehole Heat Exchanger) by fitting temperature evolution in an observer pipe inserted into borehole.
Variation of the Frost Boundary below Road and Railway Embankments in Permafrost Regions in Response to Solar Irradiation and Winds
N.I. Kömle and W. Feng
Space Research Institute, Austrian Academy of Sciences, Graz, Austria
State Key Laboratory of Frozen Soil Engineering, Cold and Arid Regions Environmental and Engineering Research Institute, Lanzhou, China
We present COMSOL solutions for a coupled gas flow and heat transfer problem, which occurs particularly when traffic pathways are constructed in high altitude and arctic regions, where the underground is frozen soil. To avoid melting of the frozen ground (which usually leads to mechanical instability) one has to find suitable measures to keep the subsurface soil and the embankment suitably cool. ...
J. Perko, D. Mallants, E. Vermariën, and W. Cool
Belgian Nuclear Research Centre (SCK-CEN), Mol, Belgium
Belgian Agency for Radioactive Waste and Enriched Fissile Material (ONDRAF/NIRAS), Mol, Belgium
Mass transport modelling through porous media is typically characterized by complex physics and geometry. In the particular case of radionuclide transport, modelling for radioactive waste repositories, an additional level of complexity, and thus uncertainty, originates from the long time frames involved. Performing a safety analysis of a radioactive waste disposal system requires therefore ...
Numerical Inversion of Surface Deformation at Long Valley Caldera (California) By Using 3D Mechanical Models
S. Pepe, P. Tizzani, and A. Manconi
IREA-CNR, Napoli, Italy
We use 3D numerical models to analyze the ground deformation observed at Long Valley Caldera (LVC) between 1992 and 2000 via space-based geodetic techniques. More specifically, we implement a complex model that includes the topography and the material heterogeneities information of LVC. The 3D heterogeneous models are implemented of COMSOL models in a Genetic Algorithm optimization to constrain ...