Understanding radionuclide uptake by carbonates

• Applicant: Professor Dr. Björn Winkler, since 8/2019
• Subject Area: Mineralogy, Petrology and Geochemistry
• Term: from 2017 to 2023
• Project identifier: Deutsche Forschungsgemeinschaft (DFG) - Project number 329533706

An assessment of the safety of a direct disposal of spent nuclear fuel in SO4-poor carbonaceous clay formations requires an understanding of the sorption capacity and processes of carbonates. The ability of carbonates to incorporate various radionuclides is determined by the structural and thermodynamic properties of carbonate solid solutions. This proposal aims to deepen our understanding of the incorporation of radium and europium in carbonates by a combined experimental-theoretical/modelling study. Central to the current proposal are experiments on double carbonates, which, despite their structural flexibility, have not been considered as hosts for radionuclides yet. We will carry out incorporation experiments using radium and europium, and investigate the products using state-of-the-art spectroscopic methods, including Raman, CARS, TRLFS and FTIR spectroscopy. We will develop and employ a multi-scale modelling approach, where DFT-based calculations are used to obtain interaction parameters, which, in turn, are used in large Monte Carlo simulations to derive thermodynamic properties. Gibbs Free energy minimisation calculations will be used to study solid-aqueous equilibria. The project will clarify to what extend double carbonates need to be considered in safety assessments and it will contribute to an atomic scale understanding of radium and actinide incorporation into carbonates.

• DFG Programme: Research Grants
• Ehemaliger Antragsteller: Dr. Victor Vinograd, until 8/2019