Modeling Chemical Interactions in the Hydrated Layers of Nuclear Waste Glasses.

1983 ◽  
Vol 26 ◽  
Author(s):  
Terrence M. Sullivan ◽  
Albert J. Machiels

ABSTRACTThe distribution of glass constituents within the hydrated layer is investigated through a mathematical representation of the fundamental processes that influence mass transport. A brief description of the models that are developed is presented. The resulting equations are implemented in a computer code named GELOH. The importance of the processes of network hydration and layer growth, alteration product formation, and dissolution is studied through the use of GELOH. The results of these studies are presented and interpreted in the light of the experimental evidence available on the aqueous corrosion of nuclear waste glass.

2018 ◽  
Vol 102 (4) ◽  
pp. 1652-1664 ◽  
Author(s):  
Hongshen Liu ◽  
Dien Ngo ◽  
Mengguo Ren ◽  
Jincheng Du ◽  
Seong H. Kim

1997 ◽  
Vol 3 (S2) ◽  
pp. 761-762
Author(s):  
W.L. Gong ◽  
L.M. Wang ◽  
R.C. Ewing

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.


2008 ◽  
Author(s):  
Sergey Stefanovsky ◽  
Alexander Barinov ◽  
Galina Varlakova ◽  
Irene Startseva ◽  
Michael I. Ojovan

2014 ◽  
Vol 7 ◽  
pp. 3-9 ◽  
Author(s):  
Étienne Vernaz ◽  
Jérôme Bruezière

1993 ◽  
Vol 333 ◽  
Author(s):  
A. Abdelouas ◽  
J. L. Crovisier ◽  
W. Lutze ◽  
R. Müller ◽  
W. Bernotat

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.


1992 ◽  
Vol 294 ◽  
Author(s):  
X. Feng ◽  
J. K. Bates ◽  
C. R. Bradley ◽  
E. C. Buck

ABSTRACTStatic tests at SA/V (ratio of surface area of glass to solution volume) 20,000 m−1 on SRL 200 glass compositions show that, at long test periods, the simulated nuclear waste glass (nonradioactive) leaches faster than the corresponding radioactive glass by a factor of about 40, although comparative tests, done through 560 days, at lower SA/V, 2000 m−1, indicate little difference in the leach behavior of the two types of glasses. The similarity in leach behavior between radioactive and simulated glasses at SAN of 2000 m−1 or lower is also observed for SRL 165/42 and 131/11 compositions. The accelerated glass reaction with the simulated glass 200S is associated with the formation of crystalline phases such as clinoptilolite (or potassium feldspar), and a pH excursion. The radiation field generated by the fully radioactive glass reduces the solution pH. This lower pH, in turn, may retard the onset of increased reaction rate. The radiation field generated by the radioactive glasses does not directly affect the stability of the glass surface alteration layer under those conditions where the radioactive and simulated glasses react at the same rate. These results suggest that the fully radioactive nuclear waste glass 200R may maintain a much lower leach rate than the simulated 200S, if the lower pH in the 200R leachate can be sustained. Meaningful comparison tests between radioactive and simulated nuclear waste glasses should include long-term and high SA/V tests.


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