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AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra B. Cochepin Direction Scientifique – Evaluation et Analyse de Performances Results and.

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Présentation au sujet: "AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra B. Cochepin Direction Scientifique – Evaluation et Analyse de Performances Results and."— Transcription de la présentation:

1 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra B. Cochepin Direction Scientifique – Evaluation et Analyse de Performances Results and new challenges in reactive transport simulations Journées Scientifiques du GNR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

2 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Presentation outline Main Andras goal: License Application (DAC) for HLW/ILLW repository in 2014 Reactive transport simulations at Andra Current limitations and progress axes Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

3 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Chemical transport simulations at Andra: schedule Objectives DAC 2014 2007-2009 1 st iteration of a chemical simulations for phenomenological behavior (PARS): conceptualization of problems and feasibility study (tools, model…) identifications of development of tools Use of reactive transport tolls for PA: to reduce conservatism, to define and quantify simplifications 2010-2012 Reference run of chemical simulations for PARS (convergence with data acquisition programs) PA simulations dedicated to chemical processes Retention Degradation RN Source term 2013-2014 Complementary studies in support to safety analysis and safety calculations for DAC Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

4 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Chemical transport simulations at Andra: a local description of complex processes Role of chemical transport simulations for Andra To acquire a detailed description of interfacial chemical processes of the repository and its surrounding geological media over 1 million years: Phenomenological simulations To participate to waste conditioning and design concept To contribute to performance assessment: Preliminary simulations Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

5 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Chemical transport simulations at Andra: Main processes Concrete degradation / alkaline plume Safety operating Durability HLW Iron corrosion Glass degradation Specific ILLW Bituminized waste ILLW/HLW RN integration Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

6 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Chemical transport simulations at Andra: Calculation specific features Interfacial problems Short distances A question of number of unknowns with highly non-linear equations Over a long period Not a matter of mesh with millions of elements Performance of algorithms Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

7 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Chemical transport simulations at Andra: numerical tools Phreeqc (USGS) Advantages: robustness, flexibility in kinetic law definition, chemical processes (ion exchange, solid solution, high ionic strength…) Drawbacks: problems with many kinetically defined minerals, 1D transport (may be adjusted), porosity feedback Crunch (LBNL) Advantages: specifically made for minerals defined with kinetic laws, various solving methods (OS3D, GIMRT) Drawbacks: absence of equilibrium chemistry and high ionic strength treatment Hytec (Ecole des Mines) Advantages: multi-D, robustness of thermodynamic calculations Drawbacks: kinetic treatment Toughreact (LBNL) Advantages: unsaturated chemical transport simulations Drawbacks: coupling, numerical convergence Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081 Feedback from ANDRA, CEA and BRGM

8 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: alkaline plume (Phreeqc) Concrete-clay interactions ~7000 cells, 30 minerals, 100 000 years 40 CPU days Progress axes Feedback on porosity, parallelization, solving methods (C. de Dieuleveult thesis) Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081 t = 0t = 10 5 years

9 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: carbonation 1/3 Diphasic simulations – Toughreact Drying physics Assessed phenomena: Gas phase diffusion of vapor Gas phase flow of vapor (under pressure gradient) Capillary flow of water Thermodynamic equilibrium liquid water/vapor Gas diffusion in liquid phase Influence of the temperature Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

10 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: carbonation 2/3 Chemistry of carbonation Near 40 mineral phases kinetically controlled, temperature Need new expressions of kinetic laws /approximations due to the unsaturated conditions Mineral reactivity depending on saturation state, CO 2 instantaneous solubilization, influence of the water released from carbonation processes on hydraulics, precipitation of other minerals... Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081 Trotignon et al. 2009 (CEA)

11 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: carbonation 3/3 Simulation performances ~100 cells (concrete/argillites, water/air/CO 2 ), 1 processor: 100 years simulated in 6 months CPU (time step limited by gas diffusion) Coupling algorithm SNIA /SIA Progress axes Solving method/numerical coupling more efficient Chemistry feedback on transport (porosity, hydraulics,…) Evolution of material texture (passivating precipitation, saturation control of kinetic laws…) … Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

12 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: organic matter/ bituminized waste Conceptual problems concerning the source term Flux control (need to be representative), degradation kinetics A complex chemistry high concentrations, redox, microbial activity Progress axes Efficiency of algorithms concerning the kinetically controlled chemistry Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

13 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: corrosion (glass, steel) Glass Phenomenological models still need to be adjusted with experimental evidences How to represent a non crystallized material (gel)? Solid solution? Steel Non porous medium Progressive consumption/expanding secondary products H 2 production (gas bubbles?) Progress axes Unsaturated simulations Kinetics of processes Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

14 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra New challenges: chemical-transport-mechanics coupling 3 applications: Degradation of argillaceous materials swelling properties of chemically degraded clays Degradation of cementitious materials/steel corrosion mechanic behaviour of waste disposal components Carbonation shrinkage, cracking mechanic behaviour of waste disposal components (B. Bary, CEA) Preliminary studies Chemical transport simulations supplies mechanic simulations: Mineral dissolution/precipitation volume variation, deformation (LMS) Progress axes Mechanic feedback on transport properties (cracking) Adapting mesh Efficiency of dedicated solving methods Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

15 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Chemical transport simulations at Andra: performance assessment PRELIMINARY Simulations Assessment of error impacts made by phenomenon simplification in performance calculations PAMINA European project: comparison of Cs transfer represented either by Kd/SL or thermodynamic models Calculation helping to radioactive waste package dimensioning Example : Influence of organic matter on radionuclide migration Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081

16 AGENCE NATIONALE POUR LA GESTION DES DÉCHETS RADIOACTIFS © Andra Conclusion and prospects Advances since 2005 Enhanced capacity to take into account integrated and complex geochemical systems Alimented by experimental programs which provides up to date conceptual models A huge step is about to be made with unsaturated chemical transport simulations Confidence in safety calculations is increased by preparatory simulations Still to come More efficient solving method/coupling algorithms New coupling (adding of unsaturated conditions/mechanics) High performance (parallelization, optimization,…) Journées Scientifiques du GDR MoMaS 23-25 Novembre 2009 DS/EAP/09-0081


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