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MS: Fachverband Massenspektrometrie
MS 1: Accelerator Mass Spectrometry and Applications
MS 1.6: Vortrag
Montag, 11. März 2019, 12:00–12:15, U A-Esch 2
Development of an analytical method for the determination of actinides in clay systems at ultra-trace levels with accelerator mass spectrometry (AMS) — •D. Glückman1, F. Quinto1, K. Hain2, C. Joseph1, V. Montoya1, P. Steier2, and H. Geckeis1 — 1Institute for Nuclear Waste Disposal, Karlsruhe Institute of Technology, Karlsruhe, Germany — 2Isotope Physics, Faculty of Physics, University of Vienna, Vienna, Austria
A potential host rock for the final disposal of high-level nuclear waste (HLW) is clay rock. In the case of the release of radionuclides from the repository, diffusion represents their main transport process in this formation. Under reducing conditions, which are expected in the repository, actinides are stabilized in low valence states (+III, +IV) normally resulting in low solubility and strong sorption in clay minerals which makes it difficult to study diffusion processes. For this reason, an analytical procedure capable of determining actinides at ultra-trace levels (fg/sample) was developed. For detection, accelerator mass spectrometry (AMS) was applied. The analytical procedure comprised the preparation of Opalinus Clay and Callovo-Oxfordian Clay / pore water samples spiked with U-233, Np-237, Pu-244, Am-243 and Cm-248, group extraction of these nuclides and their measurement with AMS. The analysis of these actinide nuclides at concentrations down to 1E+6 atoms/sample (ca. 0.4 fg/sample) from the same sample has been demonstrated by AMS. Such analytical capability will allow for the investigation of actinide diffusion under reducing conditions which will contribute to the safety assessment of HLW repositories.