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Title: Confocal {mu}-XRF, {mu}-XAFS, and {mu}-XRD Studies of Sediment from a Nuclear Waste Disposal Natural Analogue Site and Fractured Granite Following a Radiotracer Migration Experiment

Abstract

Combined {mu}-XRF, {mu}-XAFS, and {mu}-XRD investigations of a uranium-rich tertiary sediment, from a nuclear repository natural analogue site, and a fractured granite bore core section after a column tracer experiment using a Np(V) containing cocktail have been performed. Most {mu}-XRF/{mu}-XAFS measurements are recorded in a confocal geometry to provide added depth information. The U-rich sediment results show uranium to be present as a tetravalent phosphate and that U(IV) is associated with As(V). Arsenic present is either As(V) or As(0). The As(0) forms thin coatings on the surface of pyrite nodules. A hypothesis for the mechanism of uranium immobilization is proposed, where arsenopyrite acted as reductant of ground water dissolved U(VI) leading to precipitation of less soluble U(IV) and thereby forming As(V). Results for the granite sample show the immobilized Np to be tetravalent and associated with facture material.

Authors:
; ; ;  [1]; ; ;  [2];  [3];  [4];  [5]
  1. Forschungszentrum Karlsruhe, P.O. Box 3640, D-76021 Karlsruhe (Germany)
  2. Department of Chemistry, University of Antwerp, Universiteitsplein 1, B-2610 Antwerp (Belgium)
  3. Hamburger Synchrotronstrahlungslabor (HASYLAB) at DESY, Notkestr. 85, D-22603 Hamburg (Germany)
  4. Synchrotron Soleil, F-91192 Gif-sur-Yvette Cedex (France)
  5. Gesellschaft fuer Anlagen- und Reaktorsicherheit (GRS) mbH, Theodor-Heuss-Strasse 4, D-38122 Braunschweig (Germany)
Publication Date:
OSTI Identifier:
21054589
Resource Type:
Journal Article
Resource Relation:
Journal Name: AIP Conference Proceedings; Journal Volume: 882; Journal Issue: 1; Conference: XAFS13: 13. international conference on X-ray absorption fine structure, Stanford, CA (United States), 9-14 Jul 2006; Other Information: DOI: 10.1063/1.2644469; (c) 2007 American Institute of Physics; Country of input: International Atomic Energy Agency (IAEA)
Country of Publication:
United States
Language:
English
Subject:
36 MATERIALS SCIENCE; ABSORPTION SPECTROSCOPY; ARSENIC IONS; FINE STRUCTURE; GRANITES; GROUND WATER; NATURAL ANALOGUE; PHOSPHATES; PRECIPITATION; RADIOACTIVE WASTE DISPOSAL; RADIONUCLIDE MIGRATION; SEDIMENTS; SURFACES; TRACER TECHNIQUES; URANIUM; URANIUM IONS; X-RAY DIFFRACTION; X-RAY FLUORESCENCE ANALYSIS; X-RAY SPECTRA; X-RAY SPECTROSCOPY

Citation Formats

Denecke, Melissa A., Brendebach, Boris, Rothe, Joerg, Simon, Rolf, Janssens, Koen, Nolf, Wout de, Vekemans, Bart, Falkenberg, Gerald, Somogyi, Andrea, and Noseck, Ulrich. Confocal {mu}-XRF, {mu}-XAFS, and {mu}-XRD Studies of Sediment from a Nuclear Waste Disposal Natural Analogue Site and Fractured Granite Following a Radiotracer Migration Experiment. United States: N. p., 2007. Web. doi:10.1063/1.2644469.
Denecke, Melissa A., Brendebach, Boris, Rothe, Joerg, Simon, Rolf, Janssens, Koen, Nolf, Wout de, Vekemans, Bart, Falkenberg, Gerald, Somogyi, Andrea, & Noseck, Ulrich. Confocal {mu}-XRF, {mu}-XAFS, and {mu}-XRD Studies of Sediment from a Nuclear Waste Disposal Natural Analogue Site and Fractured Granite Following a Radiotracer Migration Experiment. United States. doi:10.1063/1.2644469.
Denecke, Melissa A., Brendebach, Boris, Rothe, Joerg, Simon, Rolf, Janssens, Koen, Nolf, Wout de, Vekemans, Bart, Falkenberg, Gerald, Somogyi, Andrea, and Noseck, Ulrich. Fri . "Confocal {mu}-XRF, {mu}-XAFS, and {mu}-XRD Studies of Sediment from a Nuclear Waste Disposal Natural Analogue Site and Fractured Granite Following a Radiotracer Migration Experiment". United States. doi:10.1063/1.2644469.
@article{osti_21054589,
title = {Confocal {mu}-XRF, {mu}-XAFS, and {mu}-XRD Studies of Sediment from a Nuclear Waste Disposal Natural Analogue Site and Fractured Granite Following a Radiotracer Migration Experiment},
author = {Denecke, Melissa A. and Brendebach, Boris and Rothe, Joerg and Simon, Rolf and Janssens, Koen and Nolf, Wout de and Vekemans, Bart and Falkenberg, Gerald and Somogyi, Andrea and Noseck, Ulrich},
abstractNote = {Combined {mu}-XRF, {mu}-XAFS, and {mu}-XRD investigations of a uranium-rich tertiary sediment, from a nuclear repository natural analogue site, and a fractured granite bore core section after a column tracer experiment using a Np(V) containing cocktail have been performed. Most {mu}-XRF/{mu}-XAFS measurements are recorded in a confocal geometry to provide added depth information. The U-rich sediment results show uranium to be present as a tetravalent phosphate and that U(IV) is associated with As(V). Arsenic present is either As(V) or As(0). The As(0) forms thin coatings on the surface of pyrite nodules. A hypothesis for the mechanism of uranium immobilization is proposed, where arsenopyrite acted as reductant of ground water dissolved U(VI) leading to precipitation of less soluble U(IV) and thereby forming As(V). Results for the granite sample show the immobilized Np to be tetravalent and associated with facture material.},
doi = {10.1063/1.2644469},
journal = {AIP Conference Proceedings},
number = 1,
volume = 882,
place = {United States},
year = {Fri Feb 02 00:00:00 EST 2007},
month = {Fri Feb 02 00:00:00 EST 2007}
}
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