High level and long-lived radioactive waste, here referred to as nuclear waste (NW), are best disposed of in deep geological repositories (DGR). A DGR is a multi-barrier system of engineered and natural barriers (NB) that ensure long-term isolation of NW from the biosphere. NB comprise the host rocks and, depending on regulations, may include the surrounding geological formations.
An important aspect in the development of DGR is the selection of a site where the geological characteristics of the NB and the hydrogeological conditions of the site allow waste isolation.
National programs are developed to gather the geological information needed to design and construct a safe DGR. This data will then be used for supporting decisions at each DGR stage, notably about concept choices, site selection, licensing procedures for construction, waste emplacement and closure of DGRs.
Technical designs, regulatory frameworks, evaluation and safety criteria are still evolving and differ from country to country. Additionally, every stage of the DGR procedure must be transparent and comprehensible for the public. Accordingly, social acceptance and public involvement strongly contribute to the complex process of DGR disposal.

• We seek contributions that document the lessons learned from NW disposal projects, summarizing the issues and potential solutions of DGR site characterization / selection. We welcome presentations that highlight the strong link between safety of NW disposal and geoscience fundamentals. We also invite contributions that emphasize learnings from other geoscience applications (e.g. geothermal energy extraction, geologic carbon sequestration) that have relevance to NW disposal.

• The session promotes the exchange of information about the different disposal concepts, national and transnational public outreach, involvement programs, siting approaches and regulatory frameworks. The geoscientific contributions shall underline the importance of safety cases and R&D programs in gaining societal and political confidence.

• This session provides key references about different national disposal programs that are of interest for geoscientists and engineers working in or with waste management organizations, regulatory bodies, and NGOs in national NW disposal programs. It may also attract members of the public and decision makers wanting an overview of the significant progresses in R&D related to DGR site characterization and selection.