Geoscientific knowledge is crucial to assess safety requirements for radioactive waste disposal strategies. Safety requirements include i) isolation of the nuclear waste from humans and the biosphere, ii) containment of radionuclides by retention and retardation, iii) limitation of water inflow to the geo-engineered facility and iv) long-term geological stability of the site.

The session covers all waste disposal designs, from surface and near-surface facilities to deep geological repositories, as well as borehole disposal. Key topics included in this session are:
• Role of geosciences in site characterisation and selection process
• Disposal design optimisation, including sustainable resource usage
• Geoscientific evidence supporting performance and safety assessment
• Long-term evolution studies of interactions among hydro-, geo- and biosphere, and their impact on the disposal system
• Impact of climate change on waste disposal facilities
• Innovative technologies for site characterisation and monitoring, including digital tools and artificial intelligence (AI)
• Radionuclide migration assessment
• Features and evolution of natural and engineered barrier systems, including induced effects
• Bio-geo-chemical processes, both natural and repository-induced

Contributions on the above topics can include all aspects covering lab-scale experiments, large-scale investigations in underground research facilities, information from site characterisation campaigns, studies of natural analogues, data management, review studies, and development and application of digital tools.