JRP CALL information
Supported By

European Commission

Short description of the work
The combination of the synchrotron-based microscopic methods μ-XRF, μ-XAFS and µ-XRD, which are available at the microXAS Beamline at the Swiss Light Source, made it possible to determine the Np diffusion pathways in natural clay (Opalinus Clay (OPA) from Mont Terri, Switzerland) simultaneously with the local Np speciation. The aim of this project was to bring our initial study (JPR TALI-C01-15) to the next level by measuring a time series of Np diffusion profiles. Microscopic chemical images of the evolving reactive transport pattern at multiple times are mandatory to develop a robust, dynamic reactive transport model of the migration of Np in host rocks such as OPA. Additionally, two consolidating diffusion samples based on an improved experimental technique were prepared. This allowed us, first, to improve the data quality and second, to confirm and validate the previously obtained results. Furthermore, the new diffusion cell approach was used for a pilot study with a diffusion cell related to higher salinities (1 M NaCl). This is of relevance regarding argillaceous rock formations in Northern Germany. Overall, the complementary information obtained will be important for modelling the long-term behaviour of Np(V) in possible nuclear waste repositories with an argillaceous host rock.

Main visitor contact data
Name: Jonathan Börner
Organisation: Institut für Kernchemie, Johannes Gutenberg-Universität Mainz

JRP Identification
JRP nr: TALI-C03-09
JRP title: Time-series of Np(V) diffusion profiles in Opalinus Clay measured by micro-XRF and micro-XANES
JRP scope: Scope 2: Actinide in the geological environment

Visited Associated Pooled Facility
Visited APF during the stay: PSI - MicroXAS Beamline
Name of the APF Contact Person: Dr. Daniel Grolimund

Other APF and organisation involved in the JRP
Other organisations involved:
Other APF involved in the project:

Description of the work done at the associated pooled facility
Start date of the stay: 5/19/2015
End date of the stay: 5/24/2015
Quantity of access: 6
Access Unit: Days
Misc.: Work during week-ends

Other APF visitors of the JRP during the stay
Visitor 2: Prof. Dr. Tobias Reich
Visitor 3: Dr. Samer Amayri
Visitor 4: Tim Platte