Reactive transport modelling of a spent fuel repository in a stiff clay formation considering excavation damaged zones
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Laurent De Windt
Summary
The near-field evolution of a spent fuel disposal in a deep stiff clay formation is studied with the coupled chemistry-transport code HYTEC. The study gives an example that such models can be currently used for geometries (2D and 3D) and time scales (100000 y) relevant for performance assessment. The repository consists of short tunnels with MX80 bentonite barriers and cementitious materials for mechanical support. Cesium, iodine and uranium are released from the waste packages considering instant release fractions and congruent dissolution of the fuel pellets. The calculations are carried out with special focus on the excavation damaged zone (EDZ) comparing diffusion process and different advection scenarios in this zone. Cement represents a source of alkaline perturbations but, under the pure diffusion scenario, the alteration of the multi-barrier system remains limited. The presence of the EDZ does not significantly modify radionuclide migration in the pure diffusion case. The advection scenarios, even with very slow flow velocities, illustrate the possibility of preferential pathways through the EDZ for iodine but show almost no effect on the alkaline plume and cesium migration.
© 2004 Oldenbourg Wissenschaftsverlag GmbH
Artikel in diesem Heft
- Preface: Migration Conference 2003
- Actinide chemistry: from weapons to remediation to stewardship
- Thermodynamics and solubility of (UxNp1-x)O2(am) solid solution in the carbonate system
- Solubility and colloid formation of Th(IV) in concentrated NaCl and MgCl2 solution
- Effect of reducing agents on the uranium concentration above uranium(IV) amorphous precipitate in Boom Clay pore water
- On Mo-Ru-Tc-Pd-Rh-Te alloy particles extracted from spent fuel and their leaching behavior under Ar and H2 atmospheres
- Modeling of the complex formation of metal ions with humic acids
- Application of the NICA-Donnan model for proton, copper and uranyl binding to humic acid
- Protonation and complexation of isosaccharinic acid with U(VI) and Fe(III) in acidic solutions: potentiometric and calorimetric studies
- Carbonate complexation of neptunium(IV) in highly basic solutions
- Fluorescence characteristics of complex formation of europium(III)-salicylate
- The reduction of U(VI) by near field hydrogen in the presence of UO2(s)
- Electrochemical aspects of radiolytically enhanced UO2 dissolution
- Effect of alpha radiolysis on doped UO2 dissolution under reducing conditions
- The redox behaviour of plutonium in humic rich groundwater
- The fate of radiolytic oxidants during spent fuel leaching in the presence of dissolved near field hydrogen
- Structural changes of uranyl moiety with reduction from U(VI) to U(V)
- Trivalent actinide coprecipitation with powellite (CaMoO4): Secondary solid solution formation during HLW borosilicate-glass dissolution
- Reproducibility of the uptake of U(VI) onto degraded cement pastes and calcium silicate hydrate phases
- Uranium adsorption on weathered schist – intercomparison of modelling approaches
- Contribution of minerals to the sorption of U(VI) on granite
- Distribution and geochemical association of actinides in a contaminated soil as a function of grain size
- Interactions between anionic complex species of actinides and negatively charged mineral surfaces
- Measurements and modelling of Pm sorption onto TiO2 and goethite
- Effect of humic acid on the sorption of Cm(III) onto γ-Al2O3 studied by the time-resolved laser fluorescence spectroscopy
- Am(III) and Eu(III) uptake on hematite in the presence of humic acid
- Luminescence properties of tetravalent uranium in aqueous solution
- Scanning transmission X-ray microscopy as a speciation tool for natural organic molecules
- Formation of hydroxyapatite in soils using calcium citrate and sodium phosphate for control of strontium migration
- Influence of humic substances on the 63Ni migration through crushed rock media
- U, Th, Eu and colloid mobility in a granite fracture under near-natural flow conditions
- Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms
- Interactions of trivalent and tetravalent heavy metal-siderophore complexes with Pseudomonas fluorescens
- In-situ diffusion of HTO, 22Na+, Cs+ and I- in Opalinus Clay at the Mont Terri underground rock laboratory
- Results of the colloid and radionuclide retention experiment (CRR) at the Grimsel Test Site (GTS), Switzerland – impact of reaction kinetics and speciation on radionuclide migration
- Fracture flow and radionuclide transport in block-scale laboratory experiments
- Comparison between in situ and laboratory diffusion studies of HTO and halides in Opalinus Clay from the Mont Terri
- Solubility constraints on uranium concentrations in groundwaters of the Tono uranium deposit, Japan
- Mobility of uranium in tertiary argillaceous sediments – a natural analogue study
- Redistribution of U, Pb and REE in association with alteration of uranium minerals from the Koongarra deposit, Northern Territory, Australia
- Towards a common thermodynamic database for speciation models
- Geochemically derived non-gaseous radionuclide source term for the Asse salt mine – assessment for the use of a Mg(OH)2-based backfill material
- Simulation of remediation alternatives for a 137Cs contaminated soil
- Simulating reactive transport in time dependent multiphase flow problems
- Reactive transport modelling of a spent fuel repository in a stiff clay formation considering excavation damaged zones
- Coupled transport/reaction modelling of copper canister corrosion aided by microbial processes
Artikel in diesem Heft
- Preface: Migration Conference 2003
- Actinide chemistry: from weapons to remediation to stewardship
- Thermodynamics and solubility of (UxNp1-x)O2(am) solid solution in the carbonate system
- Solubility and colloid formation of Th(IV) in concentrated NaCl and MgCl2 solution
- Effect of reducing agents on the uranium concentration above uranium(IV) amorphous precipitate in Boom Clay pore water
- On Mo-Ru-Tc-Pd-Rh-Te alloy particles extracted from spent fuel and their leaching behavior under Ar and H2 atmospheres
- Modeling of the complex formation of metal ions with humic acids
- Application of the NICA-Donnan model for proton, copper and uranyl binding to humic acid
- Protonation and complexation of isosaccharinic acid with U(VI) and Fe(III) in acidic solutions: potentiometric and calorimetric studies
- Carbonate complexation of neptunium(IV) in highly basic solutions
- Fluorescence characteristics of complex formation of europium(III)-salicylate
- The reduction of U(VI) by near field hydrogen in the presence of UO2(s)
- Electrochemical aspects of radiolytically enhanced UO2 dissolution
- Effect of alpha radiolysis on doped UO2 dissolution under reducing conditions
- The redox behaviour of plutonium in humic rich groundwater
- The fate of radiolytic oxidants during spent fuel leaching in the presence of dissolved near field hydrogen
- Structural changes of uranyl moiety with reduction from U(VI) to U(V)
- Trivalent actinide coprecipitation with powellite (CaMoO4): Secondary solid solution formation during HLW borosilicate-glass dissolution
- Reproducibility of the uptake of U(VI) onto degraded cement pastes and calcium silicate hydrate phases
- Uranium adsorption on weathered schist – intercomparison of modelling approaches
- Contribution of minerals to the sorption of U(VI) on granite
- Distribution and geochemical association of actinides in a contaminated soil as a function of grain size
- Interactions between anionic complex species of actinides and negatively charged mineral surfaces
- Measurements and modelling of Pm sorption onto TiO2 and goethite
- Effect of humic acid on the sorption of Cm(III) onto γ-Al2O3 studied by the time-resolved laser fluorescence spectroscopy
- Am(III) and Eu(III) uptake on hematite in the presence of humic acid
- Luminescence properties of tetravalent uranium in aqueous solution
- Scanning transmission X-ray microscopy as a speciation tool for natural organic molecules
- Formation of hydroxyapatite in soils using calcium citrate and sodium phosphate for control of strontium migration
- Influence of humic substances on the 63Ni migration through crushed rock media
- U, Th, Eu and colloid mobility in a granite fracture under near-natural flow conditions
- Sorption behavior of europium(III) and curium(III) on the cell surfaces of microorganisms
- Interactions of trivalent and tetravalent heavy metal-siderophore complexes with Pseudomonas fluorescens
- In-situ diffusion of HTO, 22Na+, Cs+ and I- in Opalinus Clay at the Mont Terri underground rock laboratory
- Results of the colloid and radionuclide retention experiment (CRR) at the Grimsel Test Site (GTS), Switzerland – impact of reaction kinetics and speciation on radionuclide migration
- Fracture flow and radionuclide transport in block-scale laboratory experiments
- Comparison between in situ and laboratory diffusion studies of HTO and halides in Opalinus Clay from the Mont Terri
- Solubility constraints on uranium concentrations in groundwaters of the Tono uranium deposit, Japan
- Mobility of uranium in tertiary argillaceous sediments – a natural analogue study
- Redistribution of U, Pb and REE in association with alteration of uranium minerals from the Koongarra deposit, Northern Territory, Australia
- Towards a common thermodynamic database for speciation models
- Geochemically derived non-gaseous radionuclide source term for the Asse salt mine – assessment for the use of a Mg(OH)2-based backfill material
- Simulation of remediation alternatives for a 137Cs contaminated soil
- Simulating reactive transport in time dependent multiphase flow problems
- Reactive transport modelling of a spent fuel repository in a stiff clay formation considering excavation damaged zones
- Coupled transport/reaction modelling of copper canister corrosion aided by microbial processes