Diffusion of U(VI) in Opalinus Clay Studied down to Ultratrace Levels
- Author(s)
- Daniel Glückman, Francesca Quinto, Claudia Joseph, Volker Metz, Karin Hain, Peter Steier, Horst Geckeis
- Abstract
Natural clay rocks, such as Opalinus Clay (OPA), are considered as potential host rocks for the disposal of high-level nuclear waste due to their ability to limit radionuclide transport to molecular diffusion. Laboratory studies related to the investigation of radionuclide diffusion behavior are usually performed at relatively high concentrations. For instance, U diffusion in clay rocks has been investigated at concentrations as low as approximately 10-4 mol·m-3 clay. This study addresses 233U(VI) diffusion in OPA down to ultratrace concentrations of 10-9 mol·m-3 using accelerator mass spectrometry. Fitting of the experimental data with a one-dimensional pore diffusion model revealed no significant changes in the U(VI) effective diffusion coefficient (De) over the investigated concentration range of 10-3 to 10-9 mol·m-3. Such concentration-independent behavior constitutes valuable information for the prediction of long-term U(VI) migration in geological repositories with OPA as host rock.
- Organisation(s)
- Isotope Physics
- External organisation(s)
- Karlsruher Institut für Technologie
- Journal
- Environmental Science and Technology
- Volume
- 59
- Pages
- 8694–8702
- No. of pages
- 9
- ISSN
- 0013-936X
- DOI
- https://doi.org/10.1021/acs.est.4c12739
- Publication date
- 04-2025
- Peer reviewed
- Yes
- Austrian Fields of Science 2012
- 103014 Nuclear physics, 104020 Radiochemistry, 104023 Environmental chemistry
- Keywords
- ASJC Scopus subject areas
- General Chemistry, Environmental Chemistry
- Portal url
- https://ucrisportal.univie.ac.at/en/publications/c8be6479-bc37-48d4-a45a-8367320ca521