To achieve the different objectives, the collaborative project was structured in 6 workpackages (WP1-WP5).

Beneficiaries: KIT, BRGM, NERC-BGS, CIEMAT, TU DELFT, FZJ, RWMC, SCK-CEN, UJV, ULOUGH, CTU, USFD, VTT, HZDR, LML, UAM, CSIC, ANDRA, UNIBERN, IRSN, SURREY

WP Leaders: Francis Claret (BRGM), Erika Holt (VTT), Urs Mäder (UniBern)

The overall objectives of the WP were:

• Analyses of the interface reactions in contact with different solutions (salinity, pH, redox, carbonates) with respect to changes in mineralogy and porosity evolution on
  • Low pH cement with bentonite
  • High pH cement (OPC) with Ca-Mg bentonite
• Characterization of aged cement/mortar/concrete samples in contact with natural host rocks or bentonite with respect to their changes in physical transport parameters, mineralogy and microstructure affecting transport due to mineralogical alteration (e.g. Ca leaching, carbonation)
• Characterization of samples in contact with natural host rocks at 70°C with respect to their changes in physical transport parameters, mineralogy and microstructure affecting transport due to mineralogical alteration (due to Ca leaching and carbonation)
• Study of the mechanical behaviour and the related transport properties of the interface Cement/ Clay, (e.g. OPA, COX):
  Quantification of mechanical, hydromechanical behavior and swelling ability of the low pH concrete/argillite interface under complex mechanical, hydraulic, hydric, thermal and chemical conditions.
  Derivation of a failure criterion of the interface to be used in Thermo-Hydro-Mechanical-Chemical (THMC) modelling.
• Diffusion /column experiments to quantify transport parameters including time-lapse experiments (electromigration, periodic tomography).
  • Low pH and high pH cement systems
  • Concrete / claystone interfaces
• Methodological work
  • X-ray computed tomography imaging of the pore structure
  • Complex electrical conductivity measurements on low-pH concrete in contact with pore water
  • Spatio-temporal visualization of transport processes by Positron-Emission-Tomography (PET)

Beneficiaries: KIT, A21, BRGM, FZJ, RATEN ICN, ARMINES, ULOUGH, CTU, PSI, EMPA, SURREY

WP Leader: Bernd Grambow (Armines)

The overall objectives of the WP are:

• Study of various radionuclide (Be, C, Cl, Ca, Se, Mo, I, Ra) retention processes in high pH concrete environments on relevant cement phases and alteration products.
• Analyse sorption and incorporation processes. Investigations include:
  • assessment of redox phenomena,
  • reaction kinetics,
  • changes in solubility and speciation,
  • release mechanisms,
  • solid solution formation.
• Provide a quantitative interpretation of the experiments and provide advanced mechanistic understanding and data.
• Preparation of an overview report on the state-of-knowlegde on the organics-radionuclide-cement interactions.

Beneficiaries: KIT, A21, BRGM, FZJ, NRG, RWMC, SCK-CEN, UDC, CTU, VTT, LML, ANDRA, PSI

WP Leader: Andrés Idiart (Amphos 21)

The overall objectives of the WP are:

• Process modelling in connection with WP1&WP2
  • Calibration and test of reactive transport models and inference of the reaction scheme and database for chemical/transport processes.
  • Derivation of transport/diffusion data and uptake radionuclides from experiments with non-sorbing and sorbing tracers in cement, altered cement, interface systems by reactive transport codes.
• Model development
  • Improvement of reactive transport models and codes for modelling the cement-clay interactions and the chemical, mechanical and hydrodynamic couplings with respect to
    • deformations,
    • time evolution of porosity,
    • permeability and diffusion coefficient,
    • effects of low-crystal size mineral phases,
    • retention of anionic species and
    • carbonation processes.
  • Development of numerical thermo-hydro-mechanical-chemical (THMC) models covering the gap between description of microstructural processes and the laboratory experiments.
  • Development of reactive transport models using High Performance Computing (HPC) at the micro- and/or meso-scale.
  • Multi-scale approach describing the physico-chemical processes at the mineral/water interface, in the bulk pore water, and their influence on the reactive transport properties of concrete.
    • Electrostatic surface complexation models to describe the concrete/pore water interface.
    • Multi-scale models for concrete and concrete/argillite interface taking into account effects of microstructure evolution and environmental conditions.
    • Implementation of electrically coupled multi-species transport in OpenGeoSys6-GEM code.
• Up-scaling
  • Simulation of multi-scale coupled reactive transport processes and modelling of radionuclide transport through (aged) concrete materials and concrete/host rock interfaces in the repository environment.
  • Validation macro-scale (continuum) transport predictions by experimental information at the micro-scale.
  • Validation of micro scale flow and transport model for predicting macroscopic transport properties used on microstructural information.
  • Guidelines for continuum scale modelling of the interface processes.
  • Coupling of geochemical–mass transport code and FEM mechanical calculation code to calculate the mechanical properties with the change of mineralogical alteration.

Beneficiaries: A21

WP Leader: Alba Valls (Amphos 21)

The overall objectives of the WP are:

• Contribute to ensuring next generation of expertise required for safe implementation of geological repositories.
• Contribute to further development of competence of the present expertise in the field.
• Ensure that the scientific-technical results are disseminated to the expert community.
• Providing information and knowledge management for the project implementation.
• Contribute to dissemination of the scientific-technical results to a broader interested community.
• Contribute to identification of social-political topics becoming progressively important when coming close to repository implementation.

Beneficiaries: KIT, A21

WP Leader: Marcus Altmaier (KIT), Vanessa Montoya (KIT)

The overall objectives of the WP are :

• Establishment and maintenance of the key project administrative functions.
• Creation and maintenance of the consortium agreement, partner / membership structure and project membership.
• Communication between the project and the European Commission and between different partners and bodies.
• Monitoring of the use of resources and transferring financial resources, as appropriate.
• Collection of all technical and financial data, compilation and preparation of necessary documents to do the management and activity reporting of the project to the European Commission at project month 18, 36 and 48.
• Assessment of the project progress according to reports, deliverables and milestones expected.
• Surveying the scientific / technological quality of the project.
• Presentation of the project on conferences.
• Preparation of annual workshops and kick-off meeting.