| Records |
| Author |
Denecke, M.A.; Brendebach, B.; de Nolf, W.; Falkenberg, G.; Janssens, K.; Simon, R. |
| Title |
Spatially resolved micro-X-ray fluorescence and micro-X-ray absorption fine structure study of a fractured granite bore core following a radiotracer experiment |
Type |
A1 Journal article |
Year  |
2009 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
Spectrochim Acta B |
| Volume |
64 |
Issue |
8 |
Pages |
791-795 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
Spatially resolved X-ray absorption and fluorescence investigation with a micrometer-scale resolution on actinide-containing samples provide information necessary for safety assessment of nuclear waste disposal. In this paper one example of such an experiment is presented. This example entails neptunium speciation in a fractured granite bore core from the Swedish Äspö Hard Rock Laboratory following a radiotracer experiment using µ-XAFS and µ-XRF. In order to probe micro-volumes below the surface in the granite samples and thereby avoid potential changes in the Np speciation during cutting of the bore core, a confocal irradiationdetection geometry is employed. µ-XAFS results for a selected granite bore core cross section with ~ 3 nmol Np/g reveal that Np, originally introduced as Np(V) in the tracer cocktail, is present in the granite in its reduced Np(IV) form. The Np(IV) is often present as particles, tens of µm in size. Elemental distribution maps show the tracer Np to be located in fissures and permeable channels not larger than 100 µm. The Np distribution appears often correlated with Zn also present in some fissures. We observe small granite fissures containing Fe (presumably Fe(II)), where we do not detect any Np. It is feasible that inflowing Np(V) has a shorter residence time in large fractures, while in the smaller fissures migration is slower, leading to longer residence times, i.e., reaction times, where it is reduced to less soluble Np(IV) and becomes thereby immobilized. |
| Address |
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| Corporate Author |
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Thesis |
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Place of Publication |
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Wos |
000269995300013 |
Publication Date |
2009-06-10 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0584-8547; 0038-6987 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.241 |
Times cited |
21 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.241; 2009 IF: 2.719 |
| Call Number |
UA @ admin @ c:irua:79740 |
Serial |
5837 |
| Permanent link to this record |
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| Author |
Denecke, M.A.; de Nolf, W.; Janssens, K.; Brendebach, B.; Falkenberg, G.; Noseck, U.; Rothkirch, A. |
| Title |
mu-X-ray fluorescence and mu-X-ray diffraction investigations of sediment from the Ruprechtov nuclear waste disposal natural analog site |
Type |
A1 Journal article |
| Year |
2008 |
Publication |
Spectrochimica acta: part B : atomic spectroscopy |
Abbreviated Journal |
Spectrochim Acta B |
| Volume |
63 |
Issue |
4 |
Pages |
484-492 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| Abstract |
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| Address |
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| Corporate Author |
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Thesis |
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| Publisher |
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Place of Publication |
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Editor |
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Wos |
000255817200005 |
Publication Date |
2008-01-15 |
| Series Editor |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0584-8547; 0038-6987 |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
3.241 |
Times cited |
7 |
Open Access |
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| Notes |
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Approved |
Most recent IF: 3.241; 2008 IF: 2.853 |
| Call Number |
UA @ admin @ c:irua:69131 |
Serial |
5739 |
| Permanent link to this record |
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| Author |
Denecke, M.A.; Janssens, K.; Brendebach, B.; Falkenberg, G.; Römer, J.; Simon, R.; Vekemans, B. |
| Title |
Confocal μ-XRF and μ-XAFS studies on fractured granite following a radiotracer migration experiment |
Type |
P3 Proceeding |
| Year |
2007 |
Publication |
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Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
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| Keywords |
P3 Proceeding; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Series Title |
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Edition |
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ISBN |
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Additional Links |
UA library record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:64602 |
Serial |
5551 |
| Permanent link to this record |
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| Author |
Denecke, M.A.; Janssens, K.; Brendebach, B.; Falkenberg, G.; de Nolf, W.; Römer, J. |
| Title |
Confocal μ-XRF and μ-XAFS studies of fractured granite following a radiotracer migration experiment |
Type |
H3 Book chapter |
| Year |
2007 |
Publication |
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Abbreviated Journal |
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| Volume |
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Issue |
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Pages |
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| Keywords |
H3 Book chapter; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
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Series Issue |
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Edition |
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| ISSN |
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ISBN |
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Additional Links |
UA library record |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:64600 |
Serial |
5550 |
| Permanent link to this record |
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| Author |
Denecke, M.A.; Janssens, K.; Brendebach, B.; de Nolf, W.; Falkenberg, G.; Rothe, J.; Simon, R.; Somogyi, A.; Vekemans, B.; Noseck, U. |
| 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 |
Type |
A1 Journal article |
| Year |
2007 |
Publication |
AIP conference proceedings |
Abbreviated Journal |
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| Volume |
882 |
Issue |
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Pages |
187-189 |
| Keywords |
A1 Journal article; AXES (Antwerp X-ray Analysis, Electrochemistry and Speciation) |
| 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) form 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. |
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Thesis |
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Place of Publication |
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Editor |
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Wos |
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Publication Date |
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Series Title |
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Abbreviated Series Title |
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| Series Volume |
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Series Issue |
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Edition |
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| ISSN |
0094-243x |
ISBN |
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Additional Links |
UA library record; WoS full record; WoS citing articles |
| Impact Factor |
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Times cited |
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Open Access |
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| Notes |
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Approved |
Most recent IF: NA |
| Call Number |
UA @ admin @ c:irua:103614 |
Serial |
5556 |
| Permanent link to this record |
