Fundamental understanding of radionuclide retention (FUTURE)
Quantification of long-term entrapment of key radionuclides in solid phases to inform reactive transport models and the influence of redox
'What’
This WP aims at realizing a step change in quantitative mechanistic understanding of radionuclide retention in the repository barrier system, the key mission of any repository for radioactive waste. In consequence, the raison d’être of this WP concerns the identification of constraints and the increase in 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 to develop multicomponent mechanistic sorption models, fracture and/or pore scale simulations of radionuclides transport in both in crystalline clay rock considering the combined analysis of reactivity, structure, flow field, and RN mobility/retention.
‘Why’
“ Radionuclide mobility” has been identified by the mandated actors of WMO, TSO and RE as one of the key themes (4) of the EJP, the SRA and its concretization in the 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 to all actors that this theme should also be part of the first EJP, 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 realizing as well 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.
Closing words from WP Leader
WP5 FUTURE has been successfully finished with all deliverable approved and accepted by EC within contractually agreed project timeframe of 52 months. Final project meeting took place at the University of Berne, on February 28-29, 2024, in Switzerland.
Key finding of the project is being summarized in SOTA-II update (D5.2), A shortened version of the report is submitted to Frontiers journal for publication. All research questions formulated at the beginning of the project have been considered and addressed with elan of scientific excellence. In particular, mechanistic understanding of RN retention and transport provided a consented model-based way for derivation of parameter to be used in SA/PA in real geological environment at wide range of close to equilibrium geochemical conditions. Furthermore, the developed models are not limited to radionuclides transport but provide enhanced scientific basis for simulation of repository in situ conditions. Detailed analysis of the knowledge gaps and scientific exchange with other WPs (CORI, DONUT, ACED, GAS) inspired the development of EURAD-II projects. Important contribution to knowhow transfer is the supervision of 8 joint PhDs; 3 postdocs; several MSc projects.
The success of the project and results obtained has been strongly acknowledged by leading experts in the field. The data obtained close several knowledge gaps and pave a way for future research on repository safety. The project has been a great success thank to collaborative effort of highly experienced multinational research team with sophisticated research infrastructure!
