Konkurrenz und Reversibilität bei Sorptionsvorgängen – KuRSiv

(Competition and reversibility in sorption processes)

Financed by:

German Federal Ministry for the Environment, Nature Conservation, Nuclear Safety and Consumer Protection (BMUV) under contract number 02 E 12052A

Funding period:

2023/01 – 2026/06

Cooperation Partner:

  • Helmholtz-Zentrum Dresden-Rossendorf e. V.
  • Gesellschaft für Anlagen- und Reaktorsicherheit mbH (GRS), Project coordinator
  • Karlsruhe Institute of Technology, Institute for Nuclear Waste Disposal (INE)

Staff at HZDR:

Vinzenz Brendler, Moritz Schmidt, Stephan Hilpmann, Jessica Lessing

Summary

KuRSiv is designed to study the retention of radionuclides (RN) by mineral phases in the presence of aluminum and other metal cations released during mineral dissolution. The project aims to enhance the understanding of both reversible and irreversible RN retention processes, such as sorption, incorporation, and surface precipitation, providing essential data to address safety-related questions.

The project focuses on minerals like feldspar, hematite, and mica, which are commonly found in the environment. To better understand surface mechanisms, the impact of aluminum on feldspar surfaces is analyzed using synchrotron-based surface reflectivity diffraction methods (SXD), atomic force microscopy (AFM), and other techniques. Additionally, sorption processes of Al(III) on hematite, an aluminum-free mineral, are investigated to further understand aluminum interactions with minerals.

KuRSiv will also help to improve models of RN retention in complex systems. These models will be meticulously parameterized to improve the accuracy of predictions related to sorption processes.

Overall, KuRSiv’s contributions will advance the understanding and modeling of RN retention, improve the predictive accuracy and practicality of relevant models, and facilitate more reliable decision-making in nuclear waste management. Thereby it is strengthening confidence in these predictions and the trust of the public, scientific community, and regulatory authorities in simulations of RN behavior in nuclear waste disposal. This eventually supports the siting process in Germany for a repository for highly radioactive waste in deep geologic formations.

Publications

  • J. Lessing, J. Neumann, J. Lützenkirchen, F. Bok, V. Brendler, T. Stumpf, M. Schmidt. Retention of trivalent actinides (Am, Cm) and lanthanides (Eu) by Ca feldspars. safeND 2023: Forschungssymposium des BASE, 13.-15.09.2023, Berlin, Germany.
  • J. Lessing, J. Neumann, J. Lützenkirchen, F. Bok, V. Brendler, T. Stumpf, M. Schmidt. Influence of the Competition of Al on the Retention of Trivalent Actinides and their Homologues in Feldspar. Goldschmidt Conference 2023, 09.-14.07.2023, Lyon, France.
  • J. Lessing, J. Neumann, J. Lützenkirchen, F. Bok, V. Brendler, T. Stumpf, M. Schmidt. Influence of the Competition of Al on the Retention of Trivalent Actinides and their Homologues in Feldspar. 18th International Conference on the Chemistry and Migration Behaviour of Actinides and Fission Products in the Geosphere (Migration Conference), 24.-29.09.2023, Nantes, France.
  • Lessing, J., Neumann, J., Lützenkirchen, J., Bok, F., Brendler, V., Stumpf, T., Schmidt, M. “Influence of Al on the Retention of Trivalent Actinides and their Homologues in Feldspar”. Talk, ACS Spring Meeting, 17.-21.03.2024, New Orleans, USA.
  • Lessing, J., Neumann, J., Lützenkirchen, J., Bok, F., Moisei-Rabung, S., Schild, D., Brendler, V., Stumpf, T., Schmidt, M. "Natural and synthetic plagioclases: Surface charge characterization and sorption of trivalent lanthanides (Eu) and actinides (Am, Cm)" Colloids and Surfaces A: Physicochemical and Engineering Aspects 688 (2024), 133529.