Multiactinide Analysis with Accelerator Mass Spectrometry for Ultratrace Determination in Small Samples: Application to an in Situ Radionuclide Tracer Test within the Colloid Formation and Migration Experiment at the Grimsel Test Site (Switzerland)

Author(s)

Francesca Quinto, Ingo Blechschmidt, Carmen Garcia Perez, Horst Geckeis, Frank Geyer, Robin Golser, Florian Huber, Markus Lagos, Bill Lanyon, Markus Plaschke, Peter Steier, Thorsten Schaefer

Abstract

The multiactinide analysis with accelerator mass spectrometry (AMS) was applied to samples collected from the run 13-05 of the Colloid Formation and Migration (CFM) experiment at the Grimsel Test Site (GTS). In this in situ radionuclide tracer test, the environmental behavior of

²³³U,

²³⁷Np,

²⁴²Pu, and

²⁴³Am was investigated in a water conductive shear zone under conditions relevant for a nuclear waste repository in crystalline rock. The concentration of the actinides in the GTS groundwater was determined with AMS over 6 orders of magnitude from ∼15 pg/g down to ∼25 ag/g. Levels above 10 fg/g were investigated with both sector field inductively coupled plasma mass spectrometry (SF-ICPMS) and AMS. Agreement within a relative uncertainty of 50% was found for

²³⁷Np,

²⁴²Pu, and

²⁴³Am concentrations determined with the two analytical methods. With the extreme sensitivity of AMS, the long-term release and retention of the actinides was investigated over 8 months in the tailing of the breakthrough curve of run 13-05 as well as in samples collected up to 22 months after. Furthermore, the evidence of masses 241 and 244 u in the CFM samples most probably representing

²⁴¹Am and

²⁴⁴Pu employed in a previous tracer test demonstrated the analytical capability of AMS for in situ studies lasting more than a decade.

Organisation(s)

Isotope Physics

External organisation(s)

Karlsruher Institut für Technologie, Nationale Genossenschaft für die Lagerung radioaktiver Abfälle, Rheinische Friedrich-Wilhelms-Universität Bonn, Fracture Systems Ltd, Friedrich-Schiller-Universität Jena

Journal

Analytical Chemistry

Volume

89

Pages

7182-7189

No. of pages

8

ISSN

0003-2700

DOI

https://doi.org/10.1021/acs.analchem.7b01359

Publication date

07-2017

Peer reviewed

Yes

Austrian Fields of Science 2012

103014 Nuclear physics, 104002 Analytical chemistry

Keywords

Portal url

https://ucrisportal.univie.ac.at/en/publications/9202dcf7-7e06-49e4-a0de-d2ac70a8e396