The conference will cover all topics related to natural argillaceous geological barriers and clay-based engineered barrier systems investigated by means of: laboratory experiments on clay samples (new analytical developments), in situ experiments in underground research laboratories, mock-up demonstrations and natural analogues, as well as numerical modelling and integration approaches (including up-scaling processes and treatment of uncertainties) and monitoring.
Topics will cover both scientific and technological domains, documenting progress and developments in knowledge and understanding.
Topic 1: General strategy for design and safety assessment, including RD&D programmes for clay-based disposal systems (natural and engineered barriers)
RD&D programmes (national or international) on the implementation of repositories in clay formations and development of engineered clay barriers for radioactive waste confinement, including repository design and safety assessment, lessons learned (state of scientific and technological knowledge) and priorities in R&D in line with repository development (including the role of underground research labs and pilot industrial phase).
Characterisation and modelling of undisturbed clay-based systems
Topic 2: Geology
Site characterisation (boreholes, seismics, URLs), sedimentology, diagenesis, dating techniques, discontinuities in clay rocks, clay mineralogy, micro- and nano-characterisation of argillaceous rocks and clay-based materials, large-scale 3D distribution of clay formation properties.
Topic 3: Hydrogeochemistry
Porewater geochemistry and state, isotopic characteristics of porewater, clay thermodynamics, geochemical modelling, isotope geochemistry, organics.
Topic 4: Water, solute and gas transport
Water, solute & gas transport processes, advection/dispersion, diffusion, sorption, binding state of porewater, colloid-mediated transport, formation-scale transport.
Topic 5: Hydromechanical processes
Geomechanical properties of clay rocks and clay-based materials, laboratory testing, long-term behaviour, damage/plasticity/time-dependent processes, large-scale (rock mass) geomechanical behaviour in a geological context, constitutive models.
Characterisation and modelling of repository interaction processes
Topic 6: Hydromechanical and gas transport processes during the excavation, operational and post-closure phases
EDZ (Excavation Damaged Zone) characterisation and evolution with time, constitutive models (fractured medium to equivalent porous medium), self-sealing, relationship with excavation and support methods, effect of ventilation, interactions with time between clay host rocks and repository components (clay-based seals and backfills), gas transport in the EDZ and at interfaces, including large-scale demonstration experiments and modelling.
Topic 7: Temperature-induced effects (THM coupled processes)
Thermally induced overpressure and damage, stress/strain/pressure paths in the repository near-field and at repository scale due to thermal loading, including large-scale demonstration experiments and modelling.
Topic 8: Chemical processes and radionuclide transport in the repository near-field
Oxidation effects, alkaline perturbations, hydration-dehydration processes, swelling, iron-clay interactions, influence of salts and organics, microbiological processes, including large-scale demonstration experiments and modelling.
Repository construction, long-term performance and monitoring
Topic 9: Technological operations and performance assessment of components
Methods and materials for excavation, support, sealing and backfilling, assessment of long-term performance, including large-scale demonstration experiments and modelling.
Topic 10: Monitoring (from initial state to post-closure)
Monitoring strategy, monitoring concepts and monitoring of the evolution of repository systems (near-field and site scale), RD&D on sensors for relevant processes, data mining/management, expert systems, knowledge management.