FUTURE: Fundamental understanding of radionuclide retention (EURAD WP)

“Radionuclide mobility” has been identified by WMOs, TSOs and REs as Theme 4 in the EURAD Roadmap. It is a key theme in all radioactive waste management countries in Europe, a cornerstone for any proof of safety of nuclear waste disposal concepts. Hence, it was evident that this theme should also be part of the first European Joint Programme, acknowledging that there has been research on the various topics of radionuclide migration for more than 30 years, often funded by the European Commission, but also acknowledging that various key themes have not been addressed in previous European projects (e.g. FUNMIG, SKIN, RECOSY) with sufficient depth and with sufficient potential for applicability on the real repository systems in clay or crystalline rock. The results of the project are expected to reduce uncertainties and over-conservatism of current approaches and improve the scientific basis, the realism and credibility for the safety case of deep geological disposal in clay and crystalline rock.

This WP aims to bring about a step change in quantitative mechanistic understanding of radionuclide retention in the repository barrier system – the key mission of any repository for radioactive waste. Consequently, the raison d’être of this WP concerns the identification of constraints and improving the predictability of RN migration properties in “real” clay and crystalline rocks, quantifying the influence of key parameters of the heterogeneous rock/water system such a rock structure, redox interfaces, water saturation, reversibility etc. with the goal of developing multicomponent mechanistic sorption models, fracture and/or pore scale simulations of radionuclide transport in both crystalline and clay rock considering the combined analysis of reactivity, structure, flow field, and RN mobility/retention.