The Formation of Surface Layers and Reaction Products in the Leaching of Defense Borosilicate Nuclear Waste Glass

1987 ◽  
Vol 76 (2) ◽  
pp. 263-275 ◽  
Author(s):  
Alan B. Harker ◽  
John F. Flintoff
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
Reaction Products ◽  
Surface Layers ◽  
Nuclear Waste Glass

Secondary Phase Formation and the Microstructural Evolution of Surface Layers During Vapor Phase Alteration of the French Son68 Nuclear Waste Glass at 200 °C

1995 ◽  
Vol 412 ◽  
Author(s):  
W. L. Gong ◽  
R. C. Ewing ◽  
L. M. Wang ◽  
E. Vernaz ◽  
J. K. Bates ◽  
...  
Keyword(s):  
Surface Layer ◽  
Nuclear Waste ◽  
Vapor Phase ◽  
Rare Earths ◽  
Waste Glass ◽  
Transition Elements ◽  
Surface Layers ◽  
Crystalline Phases ◽  
Developed Surface ◽  
Nuclear Waste Glass

AbstractThe SON68 inactive “R7T7” composition is the French reference glass for the LWR nuclear waste glass. Vapor phase alteration was used to accelerate the reaction progress of glass corrosion and to develop the characteristic suite of secondary, alteration phases. Extensive solid-state characterization (AEM/SEM/HRTEM) was completed on six inactive R7T7 waste glasses which were altered in the presence of saturated water vapor (200 °C) for 91, 241, 908, 1000, 1013, and 1021 days. The AEM samples were examined in cross-section (lattice-fringe imaging, microdiffraction, and quantitative thin-film EDS analysis). The glass monoliths were invariably covered with a thin altered rind. The layer became thicker with time: 0.5μm for 22 days; 4 μm for 91 days; 6 μm for 241 days; 10 μm for 908 days; 26 μm for 1013 days; and <35μm for 1021 days. The composite alteration layer of the SON68 samples is at least four time less thick than that of the SRL 131 glass composition.Six distinctive zones, based on phase chemistry and microstructure, were distinguished within the well-developed surface layers. Numerous crystalline phases such as analcime, tobermorite, apatite, and weeksite were identified on the surfaces of the reacted glasses as precipitates. Two crystalline phases, Ag2TeO3 and (Ca,Sr)Mo3O9(OH)2, were found within the inner zones of surface layers, and they must have nucleated in situ, indicating that Ag, Te, Sr, and Mo can be retained within the surface layer. The majority of the surface layer volume is composed of two morphologically and chemically different structures: one consists of well-crystallized fibrous smectite aggregates occurring along with cavities, the A-domain; and the other consists of poorlycrystallized regions containing needle-like smectite (montmorillonite) crystallites, a silica-rich amorphous matrix, and possibly ZrO2 particles, the B-domain. The retention of rare-earths and Zr mostly occurred within B-domains and that of transition elements, such as Zn, Cr, Ni, and Mn, in A-domains. The recrystallization of poorly-crystallized B-domains into well-crystallized Adomains may influence the long-term behavior of rare-earths, Zr, and transition elements. The mechanism of surface layer formation during vapor phase alteration is discussed based on the cross-sectional AEM studies of surface layers of the SON68 waste glasses.

Surface layers on a borosilicate nuclear waste glass corroded in MgCl2 solution

1997 ◽  
Vol 240 (2) ◽  
pp. 100-111 ◽  
Author(s):  
Abdesselam Abdelouas ◽  
Jean-Louis Crovisier ◽  
Werner Lutze ◽  
Bernd Grambow ◽  
Jean-Claude Dran ◽  
...  
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
Surface Layers ◽  
Nuclear Waste Glass ◽  
Mgcl2 Solution

Electron Microscopy Study of Surface Layers of The French Son68 Nuclear Waste Glass Formed During Vapor Phase Alteration At 200 °C

1997 ◽  
Vol 3 (S2) ◽  
pp. 761-762
Author(s):  
W.L. Gong ◽  
L.M. Wang ◽  
R.C. Ewing
Keyword(s):  
Nuclear Waste ◽  
Vapor Phase ◽  
Sample Surface ◽  
Microscopy Study ◽  
Electron Microscopy Study ◽  
Waste Glass ◽  
Surface Layers ◽  
Aqueous Corrosion ◽  
Thin Sections ◽  
Nuclear Waste Glass

The objective of this study was to simulate the aqueous corrosion of the nuclear waste glass over extended periods of time using vapor phase alteration by which reaction progress of glass corrosion is accelerated to form a characteristic suite of secondary alteration phases. In this study, extensive SEM/EDS, AEM, and HRTEM have been performed on the French SON68 waste glasses which were reacted in saturated water vapor at 200 °C for 908, 1013, and 1021 days, respectively. In order to study chemistry and microstructure of surface layers, TEM specimens were prepared in cross-section using the ultramicrotomy slicing technique. In this process, small chunks containing the surface layer and a thin layer of unaltered glass were broken off from the sample surface and each of these chunks was then embedded in resin to form a block. Finally, thin sections, approximately 50-90 nm thick, were microtomed from these blocks and were transferred to holey carbon coated copper grids.

Structure and chemical properties of surface layers developed on R7T7 simulated nuclear waste glass altered in brine at 190°C

1995 ◽  
Vol 7 (5) ◽  
pp. 1101-1114 ◽  
Author(s):  
Abdesselam Abdelouas ◽  
Jean-Lοuis Crovisier ◽  
Werner Lutze ◽  
Regina Müller ◽  
Walter Bernotat
Keyword(s):  
Nuclear Waste ◽  
Chemical Properties ◽  
Waste Glass ◽  
Surface Layers ◽  
Nuclear Waste Glass ◽  
And Chemical Properties

Infrared Spectroscopy Structural Analysis of Corroded Nuclear Waste Glass K-26

2008 ◽  
Author(s):  
Sergey Stefanovsky ◽  
Alexander Barinov ◽  
Galina Varlakova ◽  
Irene Startseva ◽  
Michael I. Ojovan
Keyword(s):  
Infrared Spectroscopy ◽  
Structural Analysis ◽  
Nuclear Waste ◽  
Waste Glass ◽  
Nuclear Waste Glass

scholarly journals History of Nuclear Waste Glass in France

2014 ◽  
Vol 7 ◽  
pp. 3-9 ◽  
Author(s):  
Étienne Vernaz ◽  
Jérôme Bruezière
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
Nuclear Waste Glass ◽  
History Of

Hydrotalcite Formed by Alteration of R7T7 Nuclear Waste Glass and Basaltic Glass in Salt Brine at 190°C

1993 ◽  
Vol 333 ◽  
Author(s):  
A. Abdelouas ◽  
J. L. Crovisier ◽  
W. Lutze ◽  
R. Müller ◽  
W. Bernotat
Keyword(s):  
Nuclear Waste ◽  
Waste Glass ◽  
Aluminium Content ◽  
Basaltic Glass ◽  
Alteration Product ◽  
Nuclear Waste Glass ◽  
Salt Brine ◽  
High Aluminium ◽  
Early Alteration

ABSTRACTThe R7T7 and synthetic basaltic glasses were submitted to corrosion in a saline MgCl2dominated solution at 190°C. For both glasses, the early alteration product is a hydrotalcite-like compound in which HPO42-, SO4-2and Cl-substitutes to CO32. The measured d003spacing is 7.68 Å for the hydrotalcite formed from R7T7 glass and 7.62 Å for the hydrotalcite formed from basaltic glass which reflect the high aluminium content. Chemical microanalyses show that the hydrotalcite is subsequently covered by a silica-rich gel which evolves into saponite after few months.

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